Diff of /modules/asdf/asdf.lisp [527b7f] .. [97c19a] Maximize Restore

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--- a/modules/asdf/asdf.lisp
+++ b/modules/asdf/asdf.lisp
@@ -1,5 +1,5 @@
-;;; -*- mode: common-lisp; package: asdf; -*-
-;;; This is ASDF: Another System Definition Facility.
+;;; -*- mode: Common-Lisp; Base: 10 ; Syntax: ANSI-Common-Lisp -*-
+;;; This is ASDF 2.33: Another System Definition Facility.
 ;;;
 ;;; Feedback, bug reports, and patches are all welcome:
 ;;; please mail to <asdf-devel@common-lisp.net>.
@@ -10,16 +10,16 @@
 ;;; trouble using it, or find bugs, you may want to check at the
 ;;; location above for a more recent version (and for documentation
 ;;; and test files, if your copy came without them) before reporting
-;;; bugs.  There are usually two "supported" revisions - the git HEAD
-;;; is the latest development version, whereas the revision tagged
-;;; RELEASE may be slightly older but is considered `stable'
+;;; bugs.  There are usually two "supported" revisions - the git master
+;;; branch is the latest development version, whereas the git release
+;;; branch may be slightly older but is considered `stable'
 
 ;;; -- LICENSE START
 ;;; (This is the MIT / X Consortium license as taken from
 ;;;  http://www.opensource.org/licenses/mit-license.html on or about
 ;;;  Monday; July 13, 2009)
 ;;;
-;;; Copyright (c) 2001-2010 Daniel Barlow and contributors
+;;; Copyright (c) 2001-2012 Daniel Barlow and contributors
 ;;;
 ;;; Permission is hereby granted, free of charge, to any person obtaining
 ;;; a copy of this software and associated documentation files (the
@@ -47,337 +47,1092 @@
 
 #+xcvb (module ())
 
-(cl:in-package :cl-user)
-
-#+gcl (defpackage :asdf (:use :cl)) ;; GCL treats defpackage magically and needs this
-
-(eval-when (:compile-toplevel :load-toplevel :execute)
-  ;;; make package if it doesn't exist yet.
-  ;;; DEFPACKAGE may cause errors on discrepancies, so we avoid it.
-  (unless (find-package :asdf)
-    (make-package :asdf :use '(:cl)))
-  ;;; Implementation-dependent tweaks
-  ;; (declaim (optimize (speed 2) (debug 2) (safety 3))) ; NO: rely on the implementation defaults.
-  #+allegro
+(in-package :cl-user)
+
+#+cmu
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (declaim (optimize (speed 1) (safety 3) (debug 3)))
+  (setf ext:*gc-verbose* nil))
+
+#+(or abcl clisp clozure cmu ecl xcl)
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (unless (member :asdf3 *features*)
+    (let* ((existing-version
+             (when (find-package :asdf)
+               (or (symbol-value (find-symbol (string :*asdf-version*) :asdf))
+                   (let ((ver (symbol-value (find-symbol (string :*asdf-revision*) :asdf))))
+                     (etypecase ver
+                       (string ver)
+                       (cons (format nil "~{~D~^.~}" ver))
+                       (null "1.0"))))))
+           (first-dot (when existing-version (position #\. existing-version)))
+           (second-dot (when first-dot (position #\. existing-version :start (1+ first-dot))))
+           (existing-major-minor (subseq existing-version 0 second-dot))
+           (existing-version-number (and existing-version (read-from-string existing-major-minor)))
+           (away (format nil "~A-~A" :asdf existing-version)))
+      (when (and existing-version (< existing-version-number
+                                     (or #+abcl 2.25 #+cmu 2.018 #-(or abcl cmu) 2.27)))
+        (rename-package :asdf away)
+        (when *load-verbose*
+          (format t "~&; Renamed old ~A package away to ~A~%" :asdf away))))))
+
+;;;; ---------------------------------------------------------------------------
+;;;; Handle ASDF package upgrade, including implementation-dependent magic.
+;;
+;; See https://bugs.launchpad.net/asdf/+bug/485687
+;;
+
+(defpackage :uiop/package
+  ;; CAUTION: we must handle the first few packages specially for hot-upgrade.
+  ;; This package definition MUST NOT change unless its name too changes;
+  ;; if/when it changes, don't forget to add new functions missing from below.
+  ;; Until then, asdf/package is frozen to forever
+  ;; import and export the same exact symbols as for ASDF 2.27.
+  ;; Any other symbol must be import-from'ed and re-export'ed in a different package.
+  (:use :common-lisp)
+  (:export
+   #:find-package* #:find-symbol* #:symbol-call
+   #:intern* #:export* #:import* #:shadowing-import* #:shadow* #:make-symbol* #:unintern*
+   #:symbol-shadowing-p #:home-package-p
+   #:symbol-package-name #:standard-common-lisp-symbol-p
+   #:reify-package #:unreify-package #:reify-symbol #:unreify-symbol
+   #:nuke-symbol-in-package #:nuke-symbol #:rehome-symbol
+   #:ensure-package-unused #:delete-package*
+   #:package-names #:packages-from-names #:fresh-package-name #:rename-package-away
+   #:package-definition-form #:parse-define-package-form
+   #:ensure-package #:define-package))
+
+(in-package :uiop/package)
+
+;;;; General purpose package utilities
+
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun find-package* (package-designator &optional (error t))
+    (let ((package (find-package package-designator)))
+      (cond
+        (package package)
+        (error (error "No package named ~S" (string package-designator)))
+        (t nil))))
+  (defun find-symbol* (name package-designator &optional (error t))
+    "Find a symbol in a package of given string'ified NAME;
+unless CL:FIND-SYMBOL, work well with 'modern' case sensitive syntax
+by letting you supply a symbol or keyword for the name;
+also works well when the package is not present.
+If optional ERROR argument is NIL, return NIL instead of an error
+when the symbol is not found."
+    (block nil
+      (let ((package (find-package* package-designator error)))
+        (when package ;; package error handled by find-package* already
+          (multiple-value-bind (symbol status) (find-symbol (string name) package)
+            (cond
+              (status (return (values symbol status)))
+              (error (error "There is no symbol ~S in package ~S" name (package-name package))))))
+        (values nil nil))))
+  (defun symbol-call (package name &rest args)
+    "Call a function associated with symbol of given name in given package,
+with given ARGS. Useful when the call is read before the package is loaded,
+or when loading the package is optional."
+    (apply (find-symbol* name package) args))
+  (defun intern* (name package-designator &optional (error t))
+    (intern (string name) (find-package* package-designator error)))
+  (defun export* (name package-designator)
+    (let* ((package (find-package* package-designator))
+           (symbol (intern* name package)))
+      (export (or symbol (list symbol)) package)))
+  (defun import* (symbol package-designator)
+    (import (or symbol (list symbol)) (find-package* package-designator)))
+  (defun shadowing-import* (symbol package-designator)
+    (shadowing-import (or symbol (list symbol)) (find-package* package-designator)))
+  (defun shadow* (name package-designator)
+    (shadow (string name) (find-package* package-designator)))
+  (defun make-symbol* (name)
+    (etypecase name
+      (string (make-symbol name))
+      (symbol (copy-symbol name))))
+  (defun unintern* (name package-designator &optional (error t))
+    (block nil
+      (let ((package (find-package* package-designator error)))
+        (when package
+          (multiple-value-bind (symbol status) (find-symbol* name package error)
+            (cond
+              (status (unintern symbol package)
+                      (return (values symbol status)))
+              (error (error "symbol ~A not present in package ~A"
+                            (string symbol) (package-name package))))))
+        (values nil nil))))
+  (defun symbol-shadowing-p (symbol package)
+    (and (member symbol (package-shadowing-symbols package)) t))
+  (defun home-package-p (symbol package)
+    (and package (let ((sp (symbol-package symbol)))
+                   (and sp (let ((pp (find-package* package)))
+                             (and pp (eq sp pp))))))))
+
+
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun symbol-package-name (symbol)
+    (let ((package (symbol-package symbol)))
+      (and package (package-name package))))
+  (defun standard-common-lisp-symbol-p (symbol)
+    (multiple-value-bind (sym status) (find-symbol* symbol :common-lisp nil)
+      (and (eq sym symbol) (eq status :external))))
+  (defun reify-package (package &optional package-context)
+    (if (eq package package-context) t
+        (etypecase package
+          (null nil)
+          ((eql (find-package :cl)) :cl)
+          (package (package-name package)))))
+  (defun unreify-package (package &optional package-context)
+    (etypecase package
+      (null nil)
+      ((eql t) package-context)
+      ((or symbol string) (find-package package))))
+  (defun reify-symbol (symbol &optional package-context)
+    (etypecase symbol
+      ((or keyword (satisfies standard-common-lisp-symbol-p)) symbol)
+      (symbol (vector (symbol-name symbol)
+                      (reify-package (symbol-package symbol) package-context)))))
+  (defun unreify-symbol (symbol &optional package-context)
+    (etypecase symbol
+      (symbol symbol)
+      ((simple-vector 2)
+       (let* ((symbol-name (svref symbol 0))
+              (package-foo (svref symbol 1))
+              (package (unreify-package package-foo package-context)))
+         (if package (intern* symbol-name package)
+             (make-symbol* symbol-name)))))))
+
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defvar *all-package-happiness* '())
+  (defvar *all-package-fishiness* (list t))
+  (defun record-fishy (info)
+    ;;(format t "~&FISHY: ~S~%" info)
+    (push info *all-package-fishiness*))
+  (defmacro when-package-fishiness (&body body)
+    `(when *all-package-fishiness* ,@body))
+  (defmacro note-package-fishiness (&rest info)
+    `(when-package-fishiness (record-fishy (list ,@info)))))
+
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  #+(or clisp clozure)
+  (defun get-setf-function-symbol (symbol)
+    #+clisp (let ((sym (get symbol 'system::setf-function)))
+              (if sym (values sym :setf-function)
+                  (let ((sym (get symbol 'system::setf-expander)))
+                    (if sym (values sym :setf-expander)
+                        (values nil nil)))))
+    #+clozure (gethash symbol ccl::%setf-function-names%))
+  #+(or clisp clozure)
+  (defun set-setf-function-symbol (new-setf-symbol symbol &optional kind)
+    #+clisp (assert (member kind '(:setf-function :setf-expander)))
+    #+clozure (assert (eq kind t))
+    #+clisp
+    (cond
+      ((null new-setf-symbol)
+       (remprop symbol 'system::setf-function)
+       (remprop symbol 'system::setf-expander))
+      ((eq kind :setf-function)
+       (setf (get symbol 'system::setf-function) new-setf-symbol))
+      ((eq kind :setf-expander)
+       (setf (get symbol 'system::setf-expander) new-setf-symbol))
+      (t (error "invalid kind of setf-function ~S for ~S to be set to ~S"
+                kind symbol new-setf-symbol)))
+    #+clozure
+    (progn
+      (gethash symbol ccl::%setf-function-names%) new-setf-symbol
+      (gethash new-setf-symbol ccl::%setf-function-name-inverses%) symbol))
+  #+(or clisp clozure)
+  (defun create-setf-function-symbol (symbol)
+    #+clisp (system::setf-symbol symbol)
+    #+clozure (ccl::construct-setf-function-name symbol))
+  (defun set-dummy-symbol (symbol reason other-symbol)
+    (setf (get symbol 'dummy-symbol) (cons reason other-symbol)))
+  (defun make-dummy-symbol (symbol)
+    (let ((dummy (copy-symbol symbol)))
+      (set-dummy-symbol dummy 'replacing symbol)
+      (set-dummy-symbol symbol 'replaced-by dummy)
+      dummy))
+  (defun dummy-symbol (symbol)
+    (get symbol 'dummy-symbol))
+  (defun get-dummy-symbol (symbol)
+    (let ((existing (dummy-symbol symbol)))
+      (if existing (values (cdr existing) (car existing))
+          (make-dummy-symbol symbol))))
+  (defun nuke-symbol-in-package (symbol package-designator)
+    (let ((package (find-package* package-designator))
+          (name (symbol-name symbol)))
+      (multiple-value-bind (sym stat) (find-symbol name package)
+        (when (and (member stat '(:internal :external)) (eq symbol sym))
+          (if (symbol-shadowing-p symbol package)
+              (shadowing-import* (get-dummy-symbol symbol) package)
+              (unintern* symbol package))))))
+  (defun nuke-symbol (symbol &optional (packages (list-all-packages)))
+    #+(or clisp clozure)
+    (multiple-value-bind (setf-symbol kind)
+        (get-setf-function-symbol symbol)
+      (when kind (nuke-symbol setf-symbol)))
+    (loop :for p :in packages :do (nuke-symbol-in-package symbol p)))
+  (defun rehome-symbol (symbol package-designator)
+    "Changes the home package of a symbol, also leaving it present in its old home if any"
+    (let* ((name (symbol-name symbol))
+           (package (find-package* package-designator))
+           (old-package (symbol-package symbol))
+           (old-status (and old-package (nth-value 1 (find-symbol name old-package))))
+           (shadowing (and old-package (symbol-shadowing-p symbol old-package) (make-symbol name))))
+      (multiple-value-bind (overwritten-symbol overwritten-symbol-status) (find-symbol name package)
+        (unless (eq package old-package)
+          (let ((overwritten-symbol-shadowing-p
+                  (and overwritten-symbol-status
+                       (symbol-shadowing-p overwritten-symbol package))))
+            (note-package-fishiness
+             :rehome-symbol name
+             (when old-package (package-name old-package)) old-status (and shadowing t)
+             (package-name package) overwritten-symbol-status overwritten-symbol-shadowing-p)
+            (when old-package
+              (if shadowing
+                  (shadowing-import* shadowing old-package))
+              (unintern* symbol old-package))
+            (cond
+              (overwritten-symbol-shadowing-p
+               (shadowing-import* symbol package))
+              (t
+               (when overwritten-symbol-status
+                 (unintern* overwritten-symbol package))
+               (import* symbol package)))
+            (if shadowing
+                (shadowing-import* symbol old-package)
+                (import* symbol old-package))
+            #+(or clisp clozure)
+            (multiple-value-bind (setf-symbol kind)
+                (get-setf-function-symbol symbol)
+              (when kind
+                (let* ((setf-function (fdefinition setf-symbol))
+                       (new-setf-symbol (create-setf-function-symbol symbol)))
+                  (note-package-fishiness
+                   :setf-function
+                   name (package-name package)
+                   (symbol-name setf-symbol) (symbol-package-name setf-symbol)
+                   (symbol-name new-setf-symbol) (symbol-package-name new-setf-symbol))
+                  (when (symbol-package setf-symbol)
+                    (unintern* setf-symbol (symbol-package setf-symbol)))
+                  (setf (fdefinition new-setf-symbol) setf-function)
+                  (set-setf-function-symbol new-setf-symbol symbol kind))))
+            #+(or clisp clozure)
+            (multiple-value-bind (overwritten-setf foundp)
+                (get-setf-function-symbol overwritten-symbol)
+              (when foundp
+                (unintern overwritten-setf)))
+            (when (eq old-status :external)
+              (export* symbol old-package))
+            (when (eq overwritten-symbol-status :external)
+              (export* symbol package))))
+        (values overwritten-symbol overwritten-symbol-status))))
+  (defun ensure-package-unused (package)
+    (loop :for p :in (package-used-by-list package) :do
+      (unuse-package package p)))
+  (defun delete-package* (package &key nuke)
+    (let ((p (find-package package)))
+      (when p
+        (when nuke (do-symbols (s p) (when (home-package-p s p) (nuke-symbol s))))
+        (ensure-package-unused p)
+        (delete-package package))))
+  (defun package-names (package)
+    (cons (package-name package) (package-nicknames package)))
+  (defun packages-from-names (names)
+    (remove-duplicates (remove nil (mapcar #'find-package names)) :from-end t))
+  (defun fresh-package-name (&key (prefix :%TO-BE-DELETED)
+                               separator
+                               (index (random most-positive-fixnum)))
+    (loop :for i :from index
+          :for n = (format nil "~A~@[~A~D~]" prefix (and (plusp i) (or separator "")) i)
+          :thereis (and (not (find-package n)) n)))
+  (defun rename-package-away (p &rest keys &key prefix &allow-other-keys)
+    (let ((new-name
+            (apply 'fresh-package-name
+                   :prefix (or prefix (format nil "__~A__" (package-name p))) keys)))
+      (record-fishy (list :rename-away (package-names p) new-name))
+      (rename-package p new-name))))
+
+
+;;; Communicable representation of symbol and package information
+
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun package-definition-form (package-designator
+                                  &key (nicknamesp t) (usep t)
+                                    (shadowp t) (shadowing-import-p t)
+                                    (exportp t) (importp t) internp (error t))
+    (let* ((package (or (find-package* package-designator error)
+                        (return-from package-definition-form nil)))
+           (name (package-name package))
+           (nicknames (package-nicknames package))
+           (use (mapcar #'package-name (package-use-list package)))
+           (shadow ())
+           (shadowing-import (make-hash-table :test 'equal))
+           (import (make-hash-table :test 'equal))
+           (export ())
+           (intern ()))
+      (when package
+        (loop :for sym :being :the :symbols :in package
+              :for status = (nth-value 1 (find-symbol* sym package)) :do
+                (ecase status
+                  ((nil :inherited))
+                  ((:internal :external)
+                   (let* ((name (symbol-name sym))
+                          (external (eq status :external))
+                          (home (symbol-package sym))
+                          (home-name (package-name home))
+                          (imported (not (eq home package)))
+                          (shadowing (symbol-shadowing-p sym package)))
+                     (cond
+                       ((and shadowing imported)
+                        (push name (gethash home-name shadowing-import)))
+                       (shadowing
+                        (push name shadow))
+                       (imported
+                        (push name (gethash home-name import))))
+                     (cond
+                       (external
+                        (push name export))
+                       (imported)
+                       (t (push name intern)))))))
+        (labels ((sort-names (names)
+                   (sort names #'string<))
+                 (table-keys (table)
+                   (loop :for k :being :the :hash-keys :of table :collect k))
+                 (when-relevant (key value)
+                   (when value (list (cons key value))))
+                 (import-options (key table)
+                   (loop :for i :in (sort-names (table-keys table))
+                         :collect `(,key ,i ,@(sort-names (gethash i table))))))
+          `(defpackage ,name
+             ,@(when-relevant :nicknames (and nicknamesp (sort-names nicknames)))
+             (:use ,@(and usep (sort-names use)))
+             ,@(when-relevant :shadow (and shadowp (sort-names shadow)))
+             ,@(import-options :shadowing-import-from (and shadowing-import-p shadowing-import))
+             ,@(import-options :import-from (and importp import))
+             ,@(when-relevant :export (and exportp (sort-names export)))
+             ,@(when-relevant :intern (and internp (sort-names intern)))))))))
+
+
+;;; ensure-package, define-package
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun ensure-shadowing-import (name to-package from-package shadowed imported)
+    (check-type name string)
+    (check-type to-package package)
+    (check-type from-package package)
+    (check-type shadowed hash-table)
+    (check-type imported hash-table)
+    (let ((import-me (find-symbol* name from-package)))
+      (multiple-value-bind (existing status) (find-symbol name to-package)
+        (cond
+          ((gethash name shadowed)
+           (unless (eq import-me existing)
+             (error "Conflicting shadowings for ~A" name)))
+          (t
+           (setf (gethash name shadowed) t)
+           (setf (gethash name imported) t)
+           (unless (or (null status)
+                       (and (member status '(:internal :external))
+                            (eq existing import-me)
+                            (symbol-shadowing-p existing to-package)))
+             (note-package-fishiness
+              :shadowing-import name
+              (package-name from-package)
+              (or (home-package-p import-me from-package) (symbol-package-name import-me))
+              (package-name to-package) status
+              (and status (or (home-package-p existing to-package) (symbol-package-name existing)))))
+           (shadowing-import* import-me to-package))))))
+  (defun ensure-imported (import-me into-package &optional from-package)
+    (check-type import-me symbol)
+    (check-type into-package package)
+    (check-type from-package (or null package))
+    (let ((name (symbol-name import-me)))
+      (multiple-value-bind (existing status) (find-symbol name into-package)
+        (cond
+          ((not status)
+           (import* import-me into-package))
+          ((eq import-me existing))
+          (t
+           (let ((shadowing-p (symbol-shadowing-p existing into-package)))
+             (note-package-fishiness
+              :ensure-imported name
+              (and from-package (package-name from-package))
+              (or (home-package-p import-me from-package) (symbol-package-name import-me))
+              (package-name into-package)
+              status
+              (and status (or (home-package-p existing into-package) (symbol-package-name existing)))
+              shadowing-p)
+             (cond
+               ((or shadowing-p (eq status :inherited))
+                (shadowing-import* import-me into-package))
+               (t
+                (unintern* existing into-package)
+                (import* import-me into-package))))))))
+    (values))
+  (defun ensure-import (name to-package from-package shadowed imported)
+    (check-type name string)
+    (check-type to-package package)
+    (check-type from-package package)
+    (check-type shadowed hash-table)
+    (check-type imported hash-table)
+    (multiple-value-bind (import-me import-status) (find-symbol name from-package)
+      (when (null import-status)
+        (note-package-fishiness
+         :import-uninterned name (package-name from-package) (package-name to-package))
+        (setf import-me (intern* name from-package)))
+      (multiple-value-bind (existing status) (find-symbol name to-package)
+        (cond
+          ((and imported (gethash name imported))
+           (unless (and status (eq import-me existing))
+             (error "Can't import ~S from both ~S and ~S"
+                    name (package-name (symbol-package existing)) (package-name from-package))))
+          ((gethash name shadowed)
+           (error "Can't both shadow ~S and import it from ~S" name (package-name from-package)))
+          (t
+           (setf (gethash name imported) t))))
+      (ensure-imported import-me to-package from-package)))
+  (defun ensure-inherited (name symbol to-package from-package mixp shadowed imported inherited)
+    (check-type name string)
+    (check-type symbol symbol)
+    (check-type to-package package)
+    (check-type from-package package)
+    (check-type mixp (member nil t)) ; no cl:boolean on Genera
+    (check-type shadowed hash-table)
+    (check-type imported hash-table)
+    (check-type inherited hash-table)
+    (multiple-value-bind (existing status) (find-symbol name to-package)
+      (let* ((sp (symbol-package symbol))
+             (in (gethash name inherited))
+             (xp (and status (symbol-package existing))))
+        (when (null sp)
+          (note-package-fishiness
+           :import-uninterned name
+           (package-name from-package) (package-name to-package) mixp)
+          (import* symbol from-package)
+          (setf sp (package-name from-package)))
+        (cond
+          ((gethash name shadowed))
+          (in
+           (unless (equal sp (first in))
+             (if mixp
+                 (ensure-shadowing-import name to-package (second in) shadowed imported)
+                 (error "Can't inherit ~S from ~S, it is inherited from ~S"
+                        name (package-name sp) (package-name (first in))))))
+          ((gethash name imported)
+           (unless (eq symbol existing)
+             (error "Can't inherit ~S from ~S, it is imported from ~S"
+                    name (package-name sp) (package-name xp))))
+          (t
+           (setf (gethash name inherited) (list sp from-package))
+           (when (and status (not (eq sp xp)))
+             (let ((shadowing (symbol-shadowing-p existing to-package)))
+               (note-package-fishiness
+                :inherited name
+                (package-name from-package)
+                (or (home-package-p symbol from-package) (symbol-package-name symbol))
+                (package-name to-package)
+                (or (home-package-p existing to-package) (symbol-package-name existing)))
+               (if shadowing (ensure-shadowing-import name to-package from-package shadowed imported)
+                   (unintern* existing to-package)))))))))
+  (defun ensure-mix (name symbol to-package from-package shadowed imported inherited)
+    (check-type name string)
+    (check-type symbol symbol)
+    (check-type to-package package)
+    (check-type from-package package)
+    (check-type shadowed hash-table)
+    (check-type imported hash-table)
+    (check-type inherited hash-table)
+    (unless (gethash name shadowed)
+      (multiple-value-bind (existing status) (find-symbol name to-package)
+        (let* ((sp (symbol-package symbol))
+               (im (gethash name imported))
+               (in (gethash name inherited)))
+          (cond
+            ((or (null status)
+                 (and status (eq symbol existing))
+                 (and in (eq sp (first in))))
+             (ensure-inherited name symbol to-package from-package t shadowed imported inherited))
+            (in
+             (remhash name inherited)
+             (ensure-shadowing-import name to-package (second in) shadowed imported))
+            (im
+             (error "Symbol ~S import from ~S~:[~; actually ~:[uninterned~;~:*from ~S~]~] conflicts with existing symbol in ~S~:[~; actually ~:[uninterned~;from ~:*~S~]~]"
+                    name (package-name from-package)
+                    (home-package-p symbol from-package) (symbol-package-name symbol)
+                    (package-name to-package)
+                    (home-package-p existing to-package) (symbol-package-name existing)))
+            (t
+             (ensure-inherited name symbol to-package from-package t shadowed imported inherited)))))))
+  (defun recycle-symbol (name recycle exported)
+    (check-type name string)
+    (check-type recycle list)
+    (check-type exported hash-table)
+    (when (gethash name exported) ;; don't bother recycling private symbols
+      (let (recycled foundp)
+        (dolist (r recycle (values recycled foundp))
+          (multiple-value-bind (symbol status) (find-symbol name r)
+            (when (and status (home-package-p symbol r))
+              (cond
+                (foundp
+                 ;; (nuke-symbol symbol)) -- even simple variable names like O or C will do that.
+                 (note-package-fishiness :recycled-duplicate name (package-name foundp) (package-name r)))
+                (t
+                 (setf recycled symbol foundp r)))))))))
+  (defun symbol-recycled-p (sym recycle)
+    (check-type sym symbol)
+    (check-type recycle list)
+    (and (member (symbol-package sym) recycle) t))
+  (defun ensure-symbol (name package intern recycle shadowed imported inherited exported)
+    (check-type name string)
+    (check-type package package)
+    (check-type intern (member nil t)) ; no cl:boolean on Genera
+    (check-type shadowed hash-table)
+    (check-type imported hash-table)
+    (check-type inherited hash-table)
+    (unless (or (gethash name shadowed)
+                (gethash name imported)
+                (gethash name inherited))
+      (multiple-value-bind (existing status)
+          (find-symbol name package)
+        (multiple-value-bind (recycled previous) (recycle-symbol name recycle exported)
+          (cond
+            ((and status (eq existing recycled) (eq previous package)))
+            (previous
+             (rehome-symbol recycled package))
+            ((and status (eq package (symbol-package existing))))
+            (t
+             (when status
+               (note-package-fishiness
+                :ensure-symbol name
+                (reify-package (symbol-package existing) package)
+                status intern)
+               (unintern existing))
+             (when intern
+               (intern* name package))))))))
+  (declaim (ftype function ensure-exported))
+  (defun ensure-exported-to-user (name symbol to-package &optional recycle)
+    (check-type name string)
+    (check-type symbol symbol)
+    (check-type to-package package)
+    (check-type recycle list)
+    (assert (equal name (symbol-name symbol)))
+    (multiple-value-bind (existing status) (find-symbol name to-package)
+      (unless (and status (eq symbol existing))
+        (let ((accessible
+                (or (null status)
+                    (let ((shadowing (symbol-shadowing-p existing to-package))
+                          (recycled (symbol-recycled-p existing recycle)))
+                      (unless (and shadowing (not recycled))
+                        (note-package-fishiness
+                         :ensure-export name (symbol-package-name symbol)
+                         (package-name to-package)
+                         (or (home-package-p existing to-package) (symbol-package-name existing))
+                         status shadowing)
+                        (if (or (eq status :inherited) shadowing)
+                            (shadowing-import* symbol to-package)
+                            (unintern existing to-package))
+                        t)))))
+          (when (and accessible (eq status :external))
+            (ensure-exported name symbol to-package recycle))))))
+  (defun ensure-exported (name symbol from-package &optional recycle)
+    (dolist (to-package (package-used-by-list from-package))
+      (ensure-exported-to-user name symbol to-package recycle))
+    (unless (eq from-package (symbol-package symbol))
+      (ensure-imported symbol from-package))
+    (export* name from-package))
+  (defun ensure-export (name from-package &optional recycle)
+    (multiple-value-bind (symbol status) (find-symbol* name from-package)
+      (unless (eq status :external)
+        (ensure-exported name symbol from-package recycle))))
+  (defun ensure-package (name &key
+                                nicknames documentation use
+                                shadow shadowing-import-from
+                                import-from export intern
+                                recycle mix reexport
+                                unintern)
+    #+(or gcl2.6 genera) (declare (ignore documentation))
+    (let* ((package-name (string name))
+           (nicknames (mapcar #'string nicknames))
+           (names (cons package-name nicknames))
+           (previous (packages-from-names names))
+           (discarded (cdr previous))
+           (to-delete ())
+           (package (or (first previous) (make-package package-name :nicknames nicknames)))
+           (recycle (packages-from-names recycle))
+           (use (mapcar 'find-package* use))
+           (mix (mapcar 'find-package* mix))
+           (reexport (mapcar 'find-package* reexport))
+           (shadow (mapcar 'string shadow))
+           (export (mapcar 'string export))
+           (intern (mapcar 'string intern))
+           (unintern (mapcar 'string unintern))
+           (shadowed (make-hash-table :test 'equal)) ; string to bool
+           (imported (make-hash-table :test 'equal)) ; string to bool
+           (exported (make-hash-table :test 'equal)) ; string to bool
+           ;; string to list home package and use package:
+           (inherited (make-hash-table :test 'equal)))
+      (when-package-fishiness (record-fishy package-name))
+      #-(or gcl2.6 genera)
+      (when documentation (setf (documentation package t) documentation))
+      (loop :for p :in (set-difference (package-use-list package) (append mix use))
+            :do (note-package-fishiness :over-use name (package-names p))
+                (unuse-package p package))
+      (loop :for p :in discarded
+            :for n = (remove-if #'(lambda (x) (member x names :test 'equal))
+                                (package-names p))
+            :do (note-package-fishiness :nickname name (package-names p))
+                (cond (n (rename-package p (first n) (rest n)))
+                      (t (rename-package-away p)
+                         (push p to-delete))))
+      (rename-package package package-name nicknames)
+      (dolist (name unintern)
+        (multiple-value-bind (existing status) (find-symbol name package)
+          (when status
+            (unless (eq status :inherited)
+              (note-package-fishiness
+               :unintern (package-name package) name (symbol-package-name existing) status)
+              (unintern* name package nil)))))
+      (dolist (name export)
+        (setf (gethash name exported) t))
+      (dolist (p reexport)
+        (do-external-symbols (sym p)
+          (setf (gethash (string sym) exported) t)))
+      (do-external-symbols (sym package)
+        (let ((name (symbol-name sym)))
+          (unless (gethash name exported)
+            (note-package-fishiness
+             :over-export (package-name package) name
+             (or (home-package-p sym package) (symbol-package-name sym)))
+            (unexport sym package))))
+      (dolist (name shadow)
+        (setf (gethash name shadowed) t)
+        (multiple-value-bind (existing status) (find-symbol name package)
+          (multiple-value-bind (recycled previous) (recycle-symbol name recycle exported)
+            (let ((shadowing (and status (symbol-shadowing-p existing package))))
+              (cond
+                ((eq previous package))
+                (previous
+                 (rehome-symbol recycled package))
+                ((or (member status '(nil :inherited))
+                     (home-package-p existing package)))
+                (t
+                 (let ((dummy (make-symbol name)))
+                   (note-package-fishiness
+                    :shadow-imported (package-name package) name
+                    (symbol-package-name existing) status shadowing)
+                   (shadowing-import* dummy package)
+                   (import* dummy package)))))))
+        (shadow* name package))
+      (loop :for (p . syms) :in shadowing-import-from
+            :for pp = (find-package* p) :do
+              (dolist (sym syms) (ensure-shadowing-import (string sym) package pp shadowed imported)))
+      (loop :for p :in mix
+            :for pp = (find-package* p) :do
+              (do-external-symbols (sym pp) (ensure-mix (symbol-name sym) sym package pp shadowed imported inherited)))
+      (loop :for (p . syms) :in import-from
+            :for pp = (find-package p) :do
+              (dolist (sym syms) (ensure-import (symbol-name sym) package pp shadowed imported)))
+      (dolist (p (append use mix))
+        (do-external-symbols (sym p) (ensure-inherited (string sym) sym package p nil shadowed imported inherited))
+        (use-package p package))
+      (loop :for name :being :the :hash-keys :of exported :do
+        (ensure-symbol name package t recycle shadowed imported inherited exported)
+        (ensure-export name package recycle))
+      (dolist (name intern)
+        (ensure-symbol name package t recycle shadowed imported inherited exported))
+      (do-symbols (sym package)
+        (ensure-symbol (symbol-name sym) package nil recycle shadowed imported inherited exported))
+      (map () 'delete-package* to-delete)
+      package)))
+
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun parse-define-package-form (package clauses)
+    (loop
+      :with use-p = nil :with recycle-p = nil
+      :with documentation = nil
+      :for (kw . args) :in clauses
+      :when (eq kw :nicknames) :append args :into nicknames :else
+        :when (eq kw :documentation)
+          :do (cond
+                (documentation (error "define-package: can't define documentation twice"))
+                ((or (atom args) (cdr args)) (error "define-package: bad documentation"))
+                (t (setf documentation (car args)))) :else
+      :when (eq kw :use) :append args :into use :and :do (setf use-p t) :else
+        :when (eq kw :shadow) :append args :into shadow :else
+          :when (eq kw :shadowing-import-from) :collect args :into shadowing-import-from :else
+            :when (eq kw :import-from) :collect args :into import-from :else
+              :when (eq kw :export) :append args :into export :else
+                :when (eq kw :intern) :append args :into intern :else
+                  :when (eq kw :recycle) :append args :into recycle :and :do (setf recycle-p t) :else
+                    :when (eq kw :mix) :append args :into mix :else
+                      :when (eq kw :reexport) :append args :into reexport :else
+                        :when (eq kw :unintern) :append args :into unintern :else
+                          :do (error "unrecognized define-package keyword ~S" kw)
+      :finally (return `(,package
+                         :nicknames ,nicknames :documentation ,documentation
+                         :use ,(if use-p use '(:common-lisp))
+                         :shadow ,shadow :shadowing-import-from ,shadowing-import-from
+                         :import-from ,import-from :export ,export :intern ,intern
+                         :recycle ,(if recycle-p recycle (cons package nicknames))
+                         :mix ,mix :reexport ,reexport :unintern ,unintern)))))
+
+(defmacro define-package (package &rest clauses)
+  (let ((ensure-form
+          `(apply 'ensure-package ',(parse-define-package-form package clauses))))
+    `(progn
+       #+clisp
+       (eval-when (:compile-toplevel :load-toplevel :execute)
+         ,ensure-form)
+       #+(or clisp ecl gcl) (defpackage ,package (:use))
+       (eval-when (:compile-toplevel :load-toplevel :execute)
+         ,ensure-form))))
+
+;;;; Final tricks to keep various implementations happy.
+;; We want most such tricks in common-lisp.lisp,
+;; but these need to be done before the define-package form there,
+;; that we nevertheless want to be the very first form.
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  #+allegro ;; We need to disable autoloading BEFORE any mention of package ASDF.
   (setf excl::*autoload-package-name-alist*
         (remove "asdf" excl::*autoload-package-name-alist*
                 :test 'equalp :key 'car))
-  #+ecl (require :cmp))
-
-(in-package :asdf)
-
-;;;; Create packages in a way that is compatible with hot-upgrade.
-;;;; See https://bugs.launchpad.net/asdf/+bug/485687
-;;;; See more near the end of the file.
-
+  #+gcl
+  ;; Debian's GCL 2.7 has bugs with compiling multiple-value stuff,
+  ;; but can run ASDF 2.011. GCL 2.6 has even more issues.
+  (cond
+    ((or (< system::*gcl-major-version* 2)
+         (and (= system::*gcl-major-version* 2)
+              (< system::*gcl-minor-version* 6)))
+     (error "GCL 2.6 or later required to use ASDF"))
+    ((and (= system::*gcl-major-version* 2)
+          (= system::*gcl-minor-version* 6))
+     (pushnew 'ignorable pcl::*variable-declarations-without-argument*)
+     (pushnew :gcl2.6 *features*))
+    (t
+     (pushnew :gcl2.7 *features*))))
+
+;; Compatibility with whoever calls asdf/package
+(define-package :asdf/package (:use :cl :uiop/package) (:reexport :uiop/package))
+;;;; -------------------------------------------------------------------------
+;;;; Handle compatibility with multiple implementations.
+;;; This file is for papering over the deficiencies and peculiarities
+;;; of various Common Lisp implementations.
+;;; For implementation-specific access to the system, see os.lisp instead.
+;;; A few functions are defined here, but actually exported from utility;
+;;; from this package only common-lisp symbols are exported.
+
+(uiop/package:define-package :uiop/common-lisp
+  (:nicknames :uoip/cl :asdf/common-lisp :asdf/cl)
+  (:use #-genera :common-lisp #+genera :future-common-lisp :uiop/package)
+  (:reexport :common-lisp)
+  (:recycle :uiop/common-lisp :uoip/cl :asdf/common-lisp :asdf/cl :asdf)
+  #+allegro (:intern #:*acl-warn-save*)
+  #+cormanlisp (:shadow #:user-homedir-pathname)
+  #+cormanlisp
+  (:export
+   #:logical-pathname #:translate-logical-pathname
+   #:make-broadcast-stream #:file-namestring)
+  #+gcl2.6 (:shadow #:type-of #:with-standard-io-syntax) ; causes errors when loading fasl(!)
+  #+gcl2.6 (:shadowing-import-from :system #:*load-pathname*)
+  #+genera (:shadowing-import-from :scl #:boolean)
+  #+genera (:export #:boolean #:ensure-directories-exist)
+  #+mcl (:shadow #:user-homedir-pathname))
+(in-package :uiop/common-lisp)
+
+#-(or abcl allegro clisp clozure cmu cormanlisp ecl gcl genera lispworks mcl mkcl sbcl scl xcl)
+(error "ASDF is not supported on your implementation. Please help us port it.")
+
+;; (declaim (optimize (speed 1) (debug 3) (safety 3))) ; DON'T: trust implementation defaults.
+
+
+;;;; Early meta-level tweaks
+
+#+(or abcl (and allegro ics) (and (or clisp cmu ecl mkcl) unicode)
+      clozure lispworks (and sbcl sb-unicode) scl)
 (eval-when (:load-toplevel :compile-toplevel :execute)
-  (defvar *asdf-version* nil)
-  (defvar *upgraded-p* nil)
-  (let* (;; For bug reporting sanity, please always bump this version when you modify this file.
-         ;; "2.345" would be an official release
-         ;; "2.345.6" would be a development version in the official upstream
-         ;; "2.345.0.7" would be your local modification of an official release
-         ;; "2.345.6.7" would be your local modification of a development version
-         (asdf-version "2.011")
-         (existing-asdf (fboundp 'find-system))
-         (existing-version *asdf-version*)
-         (already-there (equal asdf-version existing-version)))
-    (unless (and existing-asdf already-there)
-      (when existing-asdf
-        (format *trace-output*
-         "~&~@<; ~@;Upgrading ASDF package ~@[from version ~A ~]to version ~A~@:>~%"
-         existing-version asdf-version))
-      (labels
-          ((unlink-package (package)
-             (let ((u (find-package package)))
-               (when u
-                 (ensure-unintern u
-                   (loop :for s :being :each :present-symbol :in u :collect s))
-                 (loop :for p :in (package-used-by-list u) :do
-                   (unuse-package u p))
-                 (delete-package u))))
-           (ensure-exists (name nicknames use)
-             (let ((previous
-                    (remove-duplicates
-                     (mapcar #'find-package (cons name nicknames))
-                     :from-end t)))
-               ;; do away with packages with conflicting (nick)names
-               (map () #'unlink-package (cdr previous))
-               ;; reuse previous package with same name
-               (let ((p (car previous)))
+  (pushnew :asdf-unicode *features*))
+
+#+allegro
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defparameter *acl-warn-save*
+    (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
+      excl:*warn-on-nested-reader-conditionals*))
+  (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
+    (setf excl:*warn-on-nested-reader-conditionals* nil))
+  (setf *print-readably* nil))
+
+#+cormanlisp
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (deftype logical-pathname () nil)
+  (defun make-broadcast-stream () *error-output*)
+  (defun translate-logical-pathname (x) x)
+  (defun user-homedir-pathname (&optional host)
+    (declare (ignore host))
+    (parse-namestring (format nil "~A\\" (cl:user-homedir-pathname))))
+  (defun file-namestring (p)
+    (setf p (pathname p))
+    (format nil "~@[~A~]~@[.~A~]" (pathname-name p) (pathname-type p))))
+
+#+ecl
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (setf *load-verbose* nil)
+  (defun use-ecl-byte-compiler-p () (and (member :ecl-bytecmp *features*) t))
+  (unless (use-ecl-byte-compiler-p) (require :cmp)))
+
+#+gcl ;; Debian's GCL 2.7 has bugs with compiling multiple-value stuff, but can run ASDF 2.011
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (unless (member :ansi-cl *features*)
+    (error "ASDF only supports GCL in ANSI mode. Aborting.~%"))
+  (setf compiler::*compiler-default-type* (pathname "")
+        compiler::*lsp-ext* ""))
+
+#+gcl2.6
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (shadow 'type-of :uiop/common-lisp)
+  (shadowing-import 'system:*load-pathname* :uiop/common-lisp))
+
+#+gcl2.6
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (export 'type-of :uiop/common-lisp)
+  (export 'system:*load-pathname* :uiop/common-lisp))
+
+#+gcl2.6 ;; Doesn't support either logical-pathnames or output-translations.
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defvar *gcl2.6* t)
+  (deftype logical-pathname () nil)
+  (defun type-of (x) (class-name (class-of x)))
+  (defun wild-pathname-p (path) (declare (ignore path)) nil)
+  (defun translate-logical-pathname (x) x)
+  (defvar *compile-file-pathname* nil)
+  (defun pathname-match-p (in-pathname wild-pathname)
+    (declare (ignore in-wildname wild-wildname)) nil)
+  (defun translate-pathname (source from-wildname to-wildname &key)
+    (declare (ignore from-wildname to-wildname)) source)
+  (defun %print-unreadable-object (object stream type identity thunk)
+    (format stream "#<~@[~S ~]" (when type (type-of object)))
+    (funcall thunk)
+    (format stream "~@[ ~X~]>" (when identity (system:address object))))
+  (defmacro with-standard-io-syntax (&body body)
+    `(progn ,@body))
+  (defmacro with-compilation-unit (options &body body)
+    (declare (ignore options)) `(progn ,@body))
+  (defmacro print-unreadable-object ((object stream &key type identity) &body body)
+    `(%print-unreadable-object ,object ,stream ,type ,identity (lambda () ,@body)))
+  (defun ensure-directories-exist (path)
+    (lisp:system (format nil "mkdir -p ~S"
+                         (namestring (make-pathname :name nil :type nil :version nil :defaults path))))))
+
+#+genera
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (unless (fboundp 'ensure-directories-exist)
+    (defun ensure-directories-exist (path)
+      (fs:create-directories-recursively (pathname path)))))
+
+#.(or #+mcl ;; the #$ doesn't work on other lisps, even protected by #+mcl, so we use this trick
+      (read-from-string
+       "(eval-when (:load-toplevel :compile-toplevel :execute)
+          (ccl:define-entry-point (_getenv \"getenv\") ((name :string)) :string)
+          (ccl:define-entry-point (_system \"system\") ((name :string)) :int)
+          ;; Note: ASDF may expect user-homedir-pathname to provide
+          ;; the pathname of the current user's home directory, whereas
+          ;; MCL by default provides the directory from which MCL was started.
+          ;; See http://code.google.com/p/mcl/wiki/Portability
+          (defun user-homedir-pathname ()
+            (ccl::findfolder #$kuserdomain #$kCurrentUserFolderType))
+          (defun probe-posix (posix-namestring)
+            \"If a file exists for the posix namestring, return the pathname\"
+            (ccl::with-cstrs ((cpath posix-namestring))
+              (ccl::rlet ((is-dir :boolean)
+                          (fsref :fsref))
+                (when (eq #$noerr (#_fspathmakeref cpath fsref is-dir))
+                  (ccl::%path-from-fsref fsref is-dir))))))"))
+
+#+mkcl
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (require :cmp)
+  (setq clos::*redefine-class-in-place* t)) ;; Make sure we have strict ANSI class redefinition semantics
+
+
+;;;; Looping
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defmacro loop* (&rest rest)
+    #-genera `(loop ,@rest)
+    #+genera `(lisp:loop ,@rest))) ;; In genera, CL:LOOP can't destructure, so we use LOOP*. Sigh.
+
+
+;;;; compatfmt: avoid fancy format directives when unsupported
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun frob-substrings (string substrings &optional frob)
+    (declare (optimize (speed 0) (safety 3) (debug 3)))
+    (let ((length (length string)) (stream nil))
+      (labels ((emit-string (x &optional (start 0) (end (length x)))
+                 (when (< start end)
+                   (unless stream (setf stream (make-string-output-stream)))
+                   (write-string x stream :start start :end end)))
+               (emit-substring (start end)
+                 (when (and (zerop start) (= end length))
+                   (return-from frob-substrings string))
+                 (emit-string string start end))
+               (recurse (substrings start end)
                  (cond
-                   (p
-                    (rename-package p name nicknames)
-                    (ensure-use p use)
-                    p)
-                   (t
-                    (make-package name :nicknames nicknames :use use))))))
-           (find-sym (symbol package)
-             (find-symbol (string symbol) package))
-           (intern* (symbol package)
-             (intern (string symbol) package))
-           (remove-symbol (symbol package)
-             (let ((sym (find-sym symbol package)))
-               (when sym
-                 (unexport sym package)
-                 (unintern sym package)
-                 sym)))
-           (ensure-unintern (package symbols)
-             (loop :with packages = (list-all-packages)
-               :for sym :in symbols
-               :for removed = (remove-symbol sym package)
-               :when removed :do
-               (loop :for p :in packages :do
-                 (when (eq removed (find-sym sym p))
-                   (unintern removed p)))))
-           (ensure-shadow (package symbols)
-             (shadow symbols package))
-           (ensure-use (package use)
-             (dolist (used (reverse use))
-               (do-external-symbols (sym used)
-                 (unless (eq sym (find-sym sym package))
-                   (remove-symbol sym package)))
-               (use-package used package)))
-           (ensure-fmakunbound (package symbols)
-             (loop :for name :in symbols
-               :for sym = (find-sym name package)
-               :when sym :do (fmakunbound sym)))
-           (ensure-export (package export)
-             (let ((formerly-exported-symbols nil)
-                   (bothly-exported-symbols nil)
-                   (newly-exported-symbols nil))
-               (loop :for sym :being :each :external-symbol :in package :do
-                 (if (member sym export :test 'string-equal)
-                     (push sym bothly-exported-symbols)
-                     (push sym formerly-exported-symbols)))
-               (loop :for sym :in export :do
-                 (unless (member sym bothly-exported-symbols :test 'string-equal)
-                   (push sym newly-exported-symbols)))
-               (loop :for user :in (package-used-by-list package)
-                 :for shadowing = (package-shadowing-symbols user) :do
-                 (loop :for new :in newly-exported-symbols
-                   :for old = (find-sym new user)
-                   :when (and old (not (member old shadowing)))
-                   :do (unintern old user)))
-               (loop :for x :in newly-exported-symbols :do
-                 (export (intern* x package)))))
-           (ensure-package (name &key nicknames use unintern fmakunbound shadow export)
-             (let* ((p (ensure-exists name nicknames use)))
-               (ensure-unintern p unintern)
-               (ensure-shadow p shadow)
-               (ensure-export p export)
-               (ensure-fmakunbound p fmakunbound)
-               p)))
-        (macrolet
-            ((pkgdcl (name &key nicknames use export
-                           redefined-functions unintern fmakunbound shadow)
-                 `(ensure-package
-                   ',name :nicknames ',nicknames :use ',use :export ',export
-                   :shadow ',shadow
-                   :unintern ',(append #-(or gcl ecl) redefined-functions unintern)
-                   :fmakunbound ',(append fmakunbound))))
-          (pkgdcl
-           :asdf
-           :nicknames (:asdf-utilities) ;; DEPRECATED! Do not use, for backward compatibility only.
-           :use (:common-lisp)
-           :redefined-functions
-           (#:perform #:explain #:output-files #:operation-done-p
-            #:perform-with-restarts #:component-relative-pathname
-            #:system-source-file #:operate #:find-component #:find-system
-            #:apply-output-translations #:translate-pathname* #:resolve-location)
-           :unintern
-           (#:*asdf-revision* #:around #:asdf-method-combination
-            #:split #:make-collector
-            #:output-files-for-system-and-operation) ; obsolete ASDF-BINARY-LOCATION function
-           :fmakunbound
-           (#:system-source-file
-            #:component-relative-pathname #:system-relative-pathname
-            #:process-source-registry
-            #:inherit-source-registry #:process-source-registry-directive)
-           :export
-           (#:defsystem #:oos #:operate #:find-system #:run-shell-command
-            #:system-definition-pathname #:find-component ; miscellaneous
-            #:compile-system #:load-system #:test-system #:clear-system
-            #:compile-op #:load-op #:load-source-op
-            #:test-op
-            #:operation               ; operations
-            #:feature                 ; sort-of operation
-            #:version                 ; metaphorically sort-of an operation
-            #:version-satisfies
-
-            #:input-files #:output-files #:output-file #:perform ; operation methods
-            #:operation-done-p #:explain
-
-            #:component #:source-file
-            #:c-source-file #:cl-source-file #:java-source-file
-            #:static-file
-            #:doc-file
-            #:html-file
-            #:text-file
-            #:source-file-type
-            #:module                     ; components
-            #:system
-            #:unix-dso
-
-            #:module-components          ; component accessors
-            #:module-components-by-name  ; component accessors
-            #:component-pathname
-            #:component-relative-pathname
-            #:component-name
-            #:component-version
-            #:component-parent
-            #:component-property
-            #:component-system
-
-            #:component-depends-on
-
-            #:system-description
-            #:system-long-description
-            #:system-author
-            #:system-maintainer
-            #:system-license
-            #:system-licence
-            #:system-source-file
-            #:system-source-directory
-            #:system-relative-pathname
-            #:map-systems
-
-            #:operation-description
-            #:operation-on-warnings
-            #:operation-on-failure
-            #:component-visited-p
-            ;;#:*component-parent-pathname*
-            #:*system-definition-search-functions*
-            #:*central-registry*         ; variables
-            #:*compile-file-warnings-behaviour*
-            #:*compile-file-failure-behaviour*
-            #:*resolve-symlinks*
-            #:*asdf-verbose*
-
-            #:asdf-version
-
-            #:operation-error #:compile-failed #:compile-warned #:compile-error
-            #:error-name
-            #:error-pathname
-            #:load-system-definition-error
-            #:error-component #:error-operation
-            #:system-definition-error
-            #:missing-component
-            #:missing-component-of-version
-            #:missing-dependency
-            #:missing-dependency-of-version
-            #:circular-dependency        ; errors
-            #:duplicate-names
-
-            #:try-recompiling
-            #:retry
-            #:accept                     ; restarts
-            #:coerce-entry-to-directory
-            #:remove-entry-from-registry
-
-            #:clear-configuration
-            #:initialize-output-translations
-            #:disable-output-translations
-            #:clear-output-translations
-            #:ensure-output-translations
-            #:apply-output-translations
-            #:compile-file*
-            #:compile-file-pathname*
-            #:enable-asdf-binary-locations-compatibility
-            #:*default-source-registries*
-            #:initialize-source-registry
-            #:compute-source-registry
-            #:clear-source-registry
-            #:ensure-source-registry
-            #:process-source-registry
-            #:system-registered-p
-            #:asdf-message
-
-            ;; Utilities
-            #:absolute-pathname-p
-            ;; #:aif #:it
-            ;; #:appendf
-            #:coerce-name
-            #:directory-pathname-p
-            ;; #:ends-with
-            #:ensure-directory-pathname
-            #:getenv
-            ;; #:get-uid
-            ;; #:length=n-p
-            ;; #:find-symbol*
-            #:merge-pathnames*
-            #:pathname-directory-pathname
-            #:read-file-forms
-            ;; #:remove-keys
-            ;; #:remove-keyword
-            #:resolve-symlinks
-            #:split-string
-            #:component-name-to-pathname-components
-            #:split-name-type
-            #:subdirectories
-            #:truenamize
-            #:while-collecting)))
-        (setf *asdf-version* asdf-version
-              *upgraded-p* (if existing-version
-                               (cons existing-version *upgraded-p*)
-                               *upgraded-p*))))))
+                   ((>= start end))
+                   ((null substrings) (emit-substring start end))
+                   (t (let* ((sub-spec (first substrings))
+                             (sub (if (consp sub-spec) (car sub-spec) sub-spec))
+                             (fun (if (consp sub-spec) (cdr sub-spec) frob))
+                             (found (search sub string :start2 start :end2 end))
+                             (more (rest substrings)))
+                        (cond
+                          (found
+                           (recurse more start found)
+                           (etypecase fun
+                             (null)
+                             (string (emit-string fun))
+                             (function (funcall fun sub #'emit-string)))
+                           (recurse substrings (+ found (length sub)) end))
+                          (t
+                           (recurse more start end))))))))
+        (recurse substrings 0 length))
+      (if stream (get-output-stream-string stream) "")))
+
+  (defmacro compatfmt (format)
+    #+(or gcl genera)
+    (frob-substrings format `("~3i~_" #+(or genera gcl2.6) ,@'("~@<" "~@;" "~@:>" "~:>")))
+    #-(or gcl genera) format))
+
 
 ;;;; -------------------------------------------------------------------------
-;;;; User-visible parameters
-;;;;
-(defun asdf-version ()
-  "Exported interface to the version of ASDF currently installed. A string.
-You can compare this string with e.g.:
-(ASDF:VERSION-SATISFIES (ASDF:ASDF-VERSION) \"2.000\")."
-  *asdf-version*)
-
-(defvar *resolve-symlinks* t
-  "Determine whether or not ASDF resolves symlinks when defining systems.
-
-Defaults to T.")
-
-(defvar *compile-file-warnings-behaviour*
-  (or #+clisp :ignore :warn)
-  "How should ASDF react if it encounters a warning when compiling a file?
-Valid values are :error, :warn, and :ignore.")
-
-(defvar *compile-file-failure-behaviour*
-  (or #+sbcl :error #+clisp :ignore :warn)
-  "How should ASDF react if it encounters a failure (per the ANSI spec of COMPILE-FILE)
-when compiling a file?  Valid values are :error, :warn, and :ignore.
-Note that ASDF ALWAYS raises an error if it fails to create an output file when compiling.")
-
-(defvar *verbose-out* nil)
-
-(defvar *asdf-verbose* t)
-
-(defparameter +asdf-methods+
-  '(perform-with-restarts perform explain output-files operation-done-p))
-
-#+allegro
-(eval-when (:compile-toplevel :execute)
-  (defparameter *acl-warn-save*
-                (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
-                  excl:*warn-on-nested-reader-conditionals*))
-  (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
-    (setf excl:*warn-on-nested-reader-conditionals* nil)))
-
-;;;; -------------------------------------------------------------------------
-;;;; General Purpose Utilities
-
-(macrolet
-    ((defdef (def* def)
-       `(defmacro ,def* (name formals &rest rest)
-          `(progn
-             #+(or ecl gcl) (fmakunbound ',name)
-             ,(when (and #+ecl (symbolp name))
-                `(declaim (notinline ,name))) ; fails for setf functions on ecl
-             (,',def ,name ,formals ,@rest)))))
-  (defdef defgeneric* defgeneric)
-  (defdef defun* defun))
-
-(defmacro while-collecting ((&rest collectors) &body body)
-  "COLLECTORS should be a list of names for collections.  A collector
+;;;; General Purpose Utilities for ASDF
+
+(uiop/package:define-package :uiop/utility
+  (:nicknames :asdf/utility)
+  (:recycle :uiop/utility :asdf/utility :asdf)
+  (:use :uiop/common-lisp :uiop/package)
+  ;; import and reexport a few things defined in :asdf/common-lisp
+  (:import-from :uiop/common-lisp #:compatfmt #:loop* #:frob-substrings
+   #+ecl #:use-ecl-byte-compiler-p #+mcl #:probe-posix)
+  (:export #:compatfmt #:loop* #:frob-substrings #:compatfmt
+   #+ecl #:use-ecl-byte-compiler-p #+mcl #:probe-posix)
+  (:export
+   ;; magic helper to define debugging functions:
+   #:uiop-debug #:load-uiop-debug-utility #:*uiop-debug-utility*
+   #:undefine-function #:undefine-functions #:defun* #:defgeneric* #:with-upgradability ;; (un)defining functions
+   #:if-let ;; basic flow control
+   #:while-collecting #:appendf #:length=n-p #:ensure-list ;; lists
+   #:remove-plist-keys #:remove-plist-key ;; plists
+   #:emptyp ;; sequences
+   #:+non-base-chars-exist-p+ ;; characters
+   #:base-string-p #:strings-common-element-type #:reduce/strcat #:strcat ;; strings
+   #:first-char #:last-char #:split-string
+   #:string-prefix-p #:string-enclosed-p #:string-suffix-p
+   #:find-class* ;; CLOS
+   #:stamp< #:stamps< #:stamp*< #:stamp<= ;; stamps
+   #:earlier-stamp #:stamps-earliest #:earliest-stamp
+   #:later-stamp #:stamps-latest #:latest-stamp #:latest-stamp-f
+   #:list-to-hash-set ;; hash-table
+   #:ensure-function #:access-at #:access-at-count ;; functions
+   #:call-function #:call-functions #:register-hook-function
+   #:match-condition-p #:match-any-condition-p ;; conditions
+   #:call-with-muffled-conditions #:with-muffled-conditions
+   #:lexicographic< #:lexicographic<=
+   #:parse-version #:unparse-version #:version< #:version<= #:version-compatible-p)) ;; version
+(in-package :uiop/utility)
+
+;;;; Defining functions in a way compatible with hot-upgrade:
+;; DEFUN* and DEFGENERIC* use FMAKUNBOUND to delete any previous fdefinition,
+;; thus replacing the function without warning or error
+;; even if the signature and/or generic-ness of the function has changed.
+;; For a generic function, this invalidates any previous DEFMETHOD.
+(eval-when (:load-toplevel :compile-toplevel :execute)
+  (defun undefine-function (function-spec)
+    (cond
+      ((symbolp function-spec)
+       #+clisp
+       (let ((f (and (fboundp function-spec) (fdefinition function-spec))))
+         (when (typep f 'clos:standard-generic-function)
+           (loop :for m :in (clos:generic-function-methods f)
+                 :do (remove-method f m))))
+       (fmakunbound function-spec))
+      ((and (consp function-spec) (eq (car function-spec) 'setf)
+            (consp (cdr function-spec)) (null (cddr function-spec)))
+       #-gcl2.6 (fmakunbound function-spec))
+      (t (error "bad function spec ~S" function-spec))))
+  (defun undefine-functions (function-spec-list)
+    (map () 'undefine-function function-spec-list))
+  (macrolet
+      ((defdef (def* def)
+         `(defmacro ,def* (name formals &rest rest)
+            (destructuring-bind (name &key (supersede t))
+                (if (or (atom name) (eq (car name) 'setf))
+                    (list name :supersede nil)
+                    name)
+              (declare (ignorable supersede))
+              `(progn
+                 ;; undefining the previous function is the portable way
+                 ;; of overriding any incompatible previous gf, except on CLISP.
+                 ;; We usually try to do it only for the functions that need it,
+                 ;; which happens in asdf/upgrade - however, for ECL, we need this hammer,
+                 ;; (which causes issues in clisp)
+                 ,@(when (or #-clisp supersede #+(or ecl gcl2.7) t) ; XXX
+                     `((undefine-function ',name)))
+                 #-gcl ; gcl 2.7.0 notinline functions lose secondary return values :-(
+                 ,@(when (and #+ecl (symbolp name)) ; fails for setf functions on ecl
+                     `((declaim (notinline ,name))))
+                 (,',def ,name ,formals ,@rest))))))
+    (defdef defgeneric* defgeneric)
+    (defdef defun* defun))
+  (defmacro with-upgradability ((&optional) &body body)
+    `(eval-when (:compile-toplevel :load-toplevel :execute)
+       ,@(loop :for form :in body :collect
+               (if (consp form)
+                   (destructuring-bind (car . cdr) form
+                     (case car
+                       ((defun) `(defun* ,@cdr))
+                       ((defgeneric)
+                        (unless (or #+gcl2.6 (and (consp (car cdr)) (eq 'setf (caar cdr))))
+                          `(defgeneric* ,@cdr)))
+                       (otherwise form)))
+                   form)))))
+
+;;; Magic debugging help. See contrib/debug.lisp
+(with-upgradability ()
+  (defvar *uiop-debug-utility*
+    '(or (ignore-errors
+          (symbol-call :asdf :system-relative-pathname :uiop "contrib/debug.lisp"))
+      (symbol-call :uiop/pathname :subpathname (user-homedir-pathname) "cl/asdf/uiop/contrib/debug.lisp"))
+    "form that evaluates to the pathname to your favorite debugging utilities")
+
+  (defmacro uiop-debug (&rest keys)
+    `(eval-when (:compile-toplevel :load-toplevel :execute)
+       (load-uiop-debug-utility ,@keys)))
+
+  (defun load-uiop-debug-utility (&key package utility-file)
+    (let* ((*package* (if package (find-package package) *package*))
+           (keyword (read-from-string
+                     (format nil ":DBG-~:@(~A~)" (package-name *package*)))))
+      (unless (member keyword *features*)
+        (let* ((utility-file (or utility-file *uiop-debug-utility*))
+               (file (ignore-errors (probe-file (eval utility-file)))))
+          (if file (load file)
+              (error "Failed to locate debug utility file: ~S" utility-file)))))))
+
+
+;;; Flow control
+(with-upgradability ()
+  (defmacro if-let (bindings &body (then-form &optional else-form)) ;; from alexandria
+    ;; bindings can be (var form) or ((var1 form1) ...)
+    (let* ((binding-list (if (and (consp bindings) (symbolp (car bindings)))
+                             (list bindings)
+                             bindings))
+           (variables (mapcar #'car binding-list)))
+      `(let ,binding-list
+         (if (and ,@variables)
+             ,then-form
+             ,else-form)))))
+
+;;; List manipulation
+(with-upgradability ()
+  (defmacro while-collecting ((&rest collectors) &body body)
+    "COLLECTORS should be a list of names for collections.  A collector
 defines a function that, when applied to an argument inside BODY, will
 add its argument to the corresponding collection.  Returns multiple values,
 a list for each collection, in order.
@@ -387,185 +1142,954 @@
              \(foo \(first x\)\)
              \(bar \(second x\)\)\)\)
 Returns two values: \(A B C\) and \(1 2 3\)."
-  (let ((vars (mapcar #'(lambda (x) (gensym (symbol-name x))) collectors))
-        (initial-values (mapcar (constantly nil) collectors)))
-    `(let ,(mapcar #'list vars initial-values)
-       (flet ,(mapcar #'(lambda (c v) `(,c (x) (push x ,v) (values))) collectors vars)
-         ,@body
-         (values ,@(mapcar #'(lambda (v) `(reverse ,v)) vars))))))
-
-(defmacro aif (test then &optional else)
-  `(let ((it ,test)) (if it ,then ,else)))
-
-(defun* pathname-directory-pathname (pathname)
-  "Returns a new pathname with same HOST, DEVICE, DIRECTORY as PATHNAME,
-and NIL NAME, TYPE and VERSION components"
-  (when pathname
-    (make-pathname :name nil :type nil :version nil :defaults pathname)))
-
-(defun* merge-pathnames* (specified &optional (defaults *default-pathname-defaults*))
-  "MERGE-PATHNAMES* is like MERGE-PATHNAMES except that if the SPECIFIED pathname
-does not have an absolute directory, then the HOST and DEVICE come from the DEFAULTS.
-Also, if either argument is NIL, then the other argument is returned unmodified."
-  (when (null specified) (return-from merge-pathnames* defaults))
-  (when (null defaults) (return-from merge-pathnames* specified))
-  (let* ((specified (pathname specified))
-         (defaults (pathname defaults))
-         (directory (pathname-directory specified))
-         (directory
-          (cond
-            #-(or sbcl cmu scl)
-            ((stringp directory) `(:absolute ,directory) directory)
-            #+gcl
-            ((and (consp directory) (not (member (first directory) '(:absolute :relative))))
-             `(:relative ,@directory))
-            ((or (null directory)
-                 (and (consp directory) (member (first directory) '(:absolute :relative))))
-             directory)
-            (t
-             (error "Unrecognized directory component ~S in pathname ~S" directory specified))))
-         (name (or (pathname-name specified) (pathname-name defaults)))
-         (type (or (pathname-type specified) (pathname-type defaults)))
-         (version (or (pathname-version specified) (pathname-version defaults))))
-    (labels ((ununspecific (x)
-               (if (eq x :unspecific) nil x))
-             (unspecific-handler (p)
-               (if (typep p 'logical-pathname) #'ununspecific #'identity)))
-      (multiple-value-bind (host device directory unspecific-handler)
-          (ecase (first directory)
-            ((nil)
-             (values (pathname-host defaults)
-                     (pathname-device defaults)
-                     (pathname-directory defaults)
-                     (unspecific-handler defaults)))
-            ((:absolute)
-             (values (pathname-host specified)
-                     (pathname-device specified)
-                     directory
-                     (unspecific-handler specified)))
-            ((:relative)
-             (values (pathname-host defaults)
-                     (pathname-device defaults)
-                     (if (pathname-directory defaults)
-                         (append (pathname-directory defaults) (cdr directory))
-                         directory)
-                     (unspecific-handler defaults))))
-        (make-pathname :host host :device device :directory directory
-                       :name (funcall unspecific-handler name)
-                       :type (funcall unspecific-handler type)
-                       :version (funcall unspecific-handler version))))))
-
-(define-modify-macro appendf (&rest args)
-  append "Append onto list") ;; only to be used on short lists.
-
-(define-modify-macro orf (&rest args)
-  or "or a flag")
-
-(defun* first-char (s)
-  (and (stringp s) (plusp (length s)) (char s 0)))
-
-(defun* last-char (s)
-  (and (stringp s) (plusp (length s)) (char s (1- (length s)))))
-
-(defun* asdf-message (format-string &rest format-args)
-  (declare (dynamic-extent format-args))
-  (apply #'format *verbose-out* format-string format-args))
-
-(defun* split-string (string &key max (separator '(#\Space #\Tab)))
-  "Split STRING into a list of components separated by
+    (let ((vars (mapcar #'(lambda (x) (gensym (symbol-name x))) collectors))
+          (initial-values (mapcar (constantly nil) collectors)))
+      `(let ,(mapcar #'list vars initial-values)
+         (flet ,(mapcar #'(lambda (c v) `(,c (x) (push x ,v) (values))) collectors vars)
+           ,@body
+           (values ,@(mapcar #'(lambda (v) `(reverse ,v)) vars))))))
+
+  (define-modify-macro appendf (&rest args)
+    append "Append onto list") ;; only to be used on short lists.
+
+  (defun length=n-p (x n) ;is it that (= (length x) n) ?
+    (check-type n (integer 0 *))
+    (loop
+      :for l = x :then (cdr l)
+      :for i :downfrom n :do
+        (cond
+          ((zerop i) (return (null l)))
+          ((not (consp l)) (return nil)))))
+
+  (defun ensure-list (x)
+    (if (listp x) x (list x))))
+
+
+;;; remove a key from a plist, i.e. for keyword argument cleanup
+(with-upgradability ()
+  (defun remove-plist-key (key plist)
+    "Remove a single key from a plist"
+    (loop* :for (k v) :on plist :by #'cddr
+           :unless (eq k key)
+           :append (list k v)))
+
+  (defun remove-plist-keys (keys plist)
+    "Remove a list of keys from a plist"
+    (loop* :for (k v) :on plist :by #'cddr
+           :unless (member k keys)
+           :append (list k v))))
+
+
+;;; Sequences
+(with-upgradability ()
+  (defun emptyp (x)
+    "Predicate that is true for an empty sequence"
+    (or (null x) (and (vectorp x) (zerop (length x))))))
+
+
+;;; Characters
+(with-upgradability ()
+  (defconstant +non-base-chars-exist-p+ (not (subtypep 'character 'base-char)))
+  (when +non-base-chars-exist-p+ (pushnew :non-base-chars-exist-p *features*)))
+
+
+;;; Strings
+(with-upgradability ()
+  (defun base-string-p (string)
+    (declare (ignorable string))
+    (and #+non-base-chars-exist-p (eq 'base-char (array-element-type string))))
+
+  (defun strings-common-element-type (strings)
+    (declare (ignorable strings))
+    #-non-base-chars-exist-p 'character
+    #+non-base-chars-exist-p
+    (if (loop :for s :in strings :always (or (null s) (typep s 'base-char) (base-string-p s)))
+        'base-char 'character))
+
+  (defun reduce/strcat (strings &key key start end)
+    "Reduce a list as if by STRCAT, accepting KEY START and END keywords like REDUCE.
+NIL is interpreted as an empty string. A character is interpreted as a string of length one."
+    (when (or start end) (setf strings (subseq strings start end)))
+    (when key (setf strings (mapcar key strings)))
+    (loop :with output = (make-string (loop :for s :in strings :sum (if (characterp s) 1 (length s)))
+                                      :element-type (strings-common-element-type strings))
+          :with pos = 0
+          :for input :in strings
+          :do (etypecase input
+                (null)
+                (character (setf (char output pos) input) (incf pos))
+                (string (replace output input :start1 pos) (incf pos (length input))))
+          :finally (return output)))
+
+  (defun strcat (&rest strings)
+    (reduce/strcat strings))
+
+  (defun first-char (s)
+    (and (stringp s) (plusp (length s)) (char s 0)))
+
+  (defun last-char (s)
+    (and (stringp s) (plusp (length s)) (char s (1- (length s)))))
+
+  (defun split-string (string &key max (separator '(#\Space #\Tab)))
+    "Split STRING into a list of components separated by
 any of the characters in the sequence SEPARATOR.
 If MAX is specified, then no more than max(1,MAX) components will be returned,
 starting the separation from the end, e.g. when called with arguments
  \"a.b.c.d.e\" :max 3 :separator \".\" it will return (\"a.b.c\" \"d\" \"e\")."
-  (block nil
-    (let ((list nil) (words 0) (end (length string)))
-      (flet ((separatorp (char) (find char separator))
-             (done () (return (cons (subseq string 0 end) list))))
-        (loop
-          :for start = (if (and max (>= words (1- max)))
-                           (done)
-                           (position-if #'separatorp string :end end :from-end t)) :do
-          (when (null start)
-            (done))
-          (push (subseq string (1+ start) end) list)
-          (incf words)
-          (setf end start))))))
-
-(defun* split-name-type (filename)
-  (let ((unspecific
-         ;; Giving :unspecific as argument to make-pathname is not portable.
-         ;; See CLHS make-pathname and 19.2.2.2.3.
-         ;; We only use it on implementations that support it.
-         (or #+(or ccl ecl gcl lispworks sbcl) :unspecific)))
-    (destructuring-bind (name &optional (type unspecific))
-        (split-string filename :max 2 :separator ".")
-      (if (equal name "")
-          (values filename unspecific)
-          (values name type)))))
-
-(defun* component-name-to-pathname-components (s &key force-directory force-relative)
-  "Splits the path string S, returning three values:
-A flag that is either :absolute or :relative, indicating
-   how the rest of the values are to be interpreted.
-A directory path --- a list of strings, suitable for
-   use with MAKE-PATHNAME when prepended with the flag
-   value.
-A filename with type extension, possibly NIL in the
-   case of a directory pathname.
-FORCE-DIRECTORY forces S to be interpreted as a directory
-pathname \(third return value will be NIL, final component
-of S will be treated as part of the directory path.
-
-The intention of this function is to support structured component names,
-e.g., \(:file \"foo/bar\"\), which will be unpacked to relative
-pathnames."
-  (check-type s string)
-  (when (find #\: s)
-    (error "a portable ASDF pathname designator cannot include a #\: character: ~S" s))
-  (let* ((components (split-string s :separator "/"))
-         (last-comp (car (last components))))
-    (multiple-value-bind (relative components)
-        (if (equal (first components) "")
-            (if (equal (first-char s) #\/)
+    (block ()
+      (let ((list nil) (words 0) (end (length string)))
+        (flet ((separatorp (char) (find char separator))
+               (done () (return (cons (subseq string 0 end) list))))
+          (loop
+            :for start = (if (and max (>= words (1- max)))
+                             (done)
+                             (position-if #'separatorp string :end end :from-end t))
+            :do (when (null start) (done))
+                (push (subseq string (1+ start) end) list)
+                (incf words)
+                (setf end start))))))
+
+  (defun string-prefix-p (prefix string)
+    "Does STRING begin with PREFIX?"
+    (let* ((x (string prefix))
+           (y (string string))
+           (lx (length x))
+           (ly (length y)))
+      (and (<= lx ly) (string= x y :end2 lx))))
+
+  (defun string-suffix-p (string suffix)
+    "Does STRING end with SUFFIX?"
+    (let* ((x (string string))
+           (y (string suffix))
+           (lx (length x))
+           (ly (length y)))
+      (and (<= ly lx) (string= x y :start1 (- lx ly)))))
+
+  (defun string-enclosed-p (prefix string suffix)
+    "Does STRING begin with PREFIX and end with SUFFIX?"
+    (and (string-prefix-p prefix string)
+         (string-suffix-p string suffix))))
+
+
+;;; CLOS
+(with-upgradability ()
+  (defun find-class* (x &optional (errorp t) environment)
+    (etypecase x
+      ((or standard-class built-in-class) x)
+      #+gcl2.6 (keyword nil)
+      (symbol (find-class x errorp environment)))))
+
+
+;;; stamps: a REAL or boolean where NIL=-infinity, T=+infinity
+(eval-when (#-lispworks :compile-toplevel :load-toplevel :execute)
+  (deftype stamp () '(or real boolean)))
+(with-upgradability ()
+  (defun stamp< (x y)
+    (etypecase x
+      (null (and y t))
+      ((eql t) nil)
+      (real (etypecase y
+              (null nil)
+              ((eql t) t)
+              (real (< x y))))))
+  (defun stamps< (list) (loop :for y :in list :for x = nil :then y :always (stamp< x y)))
+  (defun stamp*< (&rest list) (stamps< list))
+  (defun stamp<= (x y) (not (stamp< y x)))
+  (defun earlier-stamp (x y) (if (stamp< x y) x y))
+  (defun stamps-earliest (list) (reduce 'earlier-stamp list :initial-value t))
+  (defun earliest-stamp (&rest list) (stamps-earliest list))
+  (defun later-stamp (x y) (if (stamp< x y) y x))
+  (defun stamps-latest (list) (reduce 'later-stamp list :initial-value nil))
+  (defun latest-stamp (&rest list) (stamps-latest list))
+  (define-modify-macro latest-stamp-f (&rest stamps) latest-stamp))
+
+
+;;; Hash-tables
+(with-upgradability ()
+  (defun list-to-hash-set (list &aux (h (make-hash-table :test 'equal)))
+    (dolist (x list h) (setf (gethash x h) t))))
+
+
+;;; Function designators
+(with-upgradability ()
+  (defun ensure-function (fun &key (package :cl))
+    "Coerce the object FUN into a function.
+
+If FUN is a FUNCTION, return it.
+If the FUN is a non-sequence literal constant, return constantly that,
+i.e. for a boolean keyword character number or pathname.
+Otherwise if FUN is a non-literally constant symbol, return its FDEFINITION.
+If FUN is a CONS, return the function that applies its CAR
+to the appended list of the rest of its CDR and the arguments.
+If FUN is a string, READ a form from it in the specified PACKAGE (default: CL)
+and EVAL that in a (FUNCTION ...) context."
+    (etypecase fun
+      (function fun)
+      ((or boolean keyword character number pathname) (constantly fun))
+      ((or function symbol) fun)
+      (cons #'(lambda (&rest args) (apply (car fun) (append (cdr fun) args))))
+      (string (eval `(function ,(with-standard-io-syntax
+                                  (let ((*package* (find-package package)))
+                                    (read-from-string fun))))))))
+
+  (defun access-at (object at)
+    "Given an OBJECT and an AT specifier, list of successive accessors,
+call each accessor on the result of the previous calls.
+An accessor may be an integer, meaning a call to ELT,
+a keyword, meaning a call to GETF,
+NIL, meaning identity,
+a function or other symbol, meaning itself,
+or a list of a function designator and arguments, interpreted as per ENSURE-FUNCTION.
+As a degenerate case, the AT specifier may be an atom of a single such accessor
+instead of a list."
+    (flet ((access (object accessor)
+             (etypecase accessor
+               (function (funcall accessor object))
+               (integer (elt object accessor))
+               (keyword (getf object accessor))
+               (null object)
+               (symbol (funcall accessor object))
+               (cons (funcall (ensure-function accessor) object)))))
+      (if (listp at)
+          (dolist (accessor at object)
+            (setf object (access object accessor)))
+          (access object at))))
+
+  (defun access-at-count (at)
+    "From an AT specification, extract a COUNT of maximum number
+   of sub-objects to read as per ACCESS-AT"
+    (cond
+      ((integerp at)
+       (1+ at))
+      ((and (consp at) (integerp (first at)))
+       (1+ (first at)))))
+
+  (defun call-function (function-spec &rest arguments)
+    (apply (ensure-function function-spec) arguments))
+
+  (defun call-functions (function-specs)
+    (map () 'call-function function-specs))
+
+  (defun register-hook-function (variable hook &optional call-now-p)
+    (pushnew hook (symbol-value variable))
+    (when call-now-p (call-function hook))))
+
+
+;;; Version handling
+(with-upgradability ()
+  (defun unparse-version (version-list)
+    (format nil "~{~D~^.~}" version-list))
+
+  (defun parse-version (version-string &optional on-error)
+    "Parse a VERSION-STRING as a series of natural integers separated by dots.
+Return a (non-null) list of integers if the string is valid;
+otherwise return NIL.
+
+When invalid, ON-ERROR is called as per CALL-FUNCTION before to return NIL,
+with format arguments explaining why the version is invalid.
+ON-ERROR is also called if the version is not canonical
+in that it doesn't print back to itself, but the list is returned anyway."
+    (block nil
+      (unless (stringp version-string)
+        (call-function on-error "~S: ~S is not a string" 'parse-version version-string)
+        (return))
+      (unless (loop :for prev = nil :then c :for c :across version-string
+                    :always (or (digit-char-p c)
+                                (and (eql c #\.) prev (not (eql prev #\.))))
+                    :finally (return (and c (digit-char-p c))))
+        (call-function on-error "~S: ~S doesn't follow asdf version numbering convention"
+                       'parse-version version-string)
+        (return))
+      (let* ((version-list
+               (mapcar #'parse-integer (split-string version-string :separator ".")))
+             (normalized-version (unparse-version version-list)))
+        (unless (equal version-string normalized-version)
+          (call-function on-error "~S: ~S contains leading zeros" 'parse-version version-string))
+        version-list)))
+
+  (defun lexicographic< (< x y)
+    (cond ((null y) nil)
+          ((null x) t)
+          ((funcall < (car x) (car y)) t)
+          ((funcall < (car y) (car x)) nil)
+          (t (lexicographic< < (cdr x) (cdr y)))))
+
+  (defun lexicographic<= (< x y)
+    (not (lexicographic< < y x)))
+
+  (defun version< (version1 version2)
+    (let ((v1 (parse-version version1 nil))
+          (v2 (parse-version version2 nil)))
+      (lexicographic< '< v1 v2)))
+
+  (defun version<= (version1 version2)
+    (not (version< version2 version1)))
+
+  (defun version-compatible-p (provided-version required-version)
+    "Is the provided version a compatible substitution for the required-version?
+If major versions differ, it's not compatible.
+If they are equal, then any later version is compatible,
+with later being determined by a lexicographical comparison of minor numbers."
+    (let ((x (parse-version provided-version nil))
+          (y (parse-version required-version nil)))
+      (and x y (= (car x) (car y)) (lexicographic<= '< (cdr y) (cdr x))))))
+
+
+;;; Condition control
+
+(with-upgradability ()
+  (defparameter +simple-condition-format-control-slot+
+    #+abcl 'system::format-control
+    #+allegro 'excl::format-control
+    #+clisp 'system::$format-control
+    #+clozure 'ccl::format-control
+    #+(or cmu scl) 'conditions::format-control
+    #+ecl 'si::format-control
+    #+(or gcl lispworks) 'conditions::format-string
+    #+sbcl 'sb-kernel:format-control
+    #-(or abcl allegro clisp clozure cmu ecl gcl lispworks sbcl scl) nil
+    "Name of the slot for FORMAT-CONTROL in simple-condition")
+
+  (defun match-condition-p (x condition)
+    "Compare received CONDITION to some pattern X:
+a symbol naming a condition class,
+a simple vector of length 2, arguments to find-symbol* with result as above,
+or a string describing the format-control of a simple-condition."
+    (etypecase x
+      (symbol (typep condition x))
+      ((simple-vector 2) (typep condition (find-symbol* (svref x 0) (svref x 1) nil)))
+      (function (funcall x condition))
+      (string (and (typep condition 'simple-condition)
+                   ;; On SBCL, it's always set and the check triggers a warning
+                   #+(or allegro clozure cmu lispworks scl)
+                   (slot-boundp condition +simple-condition-format-control-slot+)
+                   (ignore-errors (equal (simple-condition-format-control condition) x))))))
+
+  (defun match-any-condition-p (condition conditions)
+    "match CONDITION against any of the patterns of CONDITIONS supplied"
+    (loop :for x :in conditions :thereis (match-condition-p x condition)))
+
+  (defun call-with-muffled-conditions (thunk conditions)
+    (handler-bind ((t #'(lambda (c) (when (match-any-condition-p c conditions)
+                                      (muffle-warning c)))))
+      (funcall thunk)))
+
+  (defmacro with-muffled-conditions ((conditions) &body body)
+    `(call-with-muffled-conditions #'(lambda () ,@body) ,conditions)))
+
+
+;;;; ---------------------------------------------------------------------------
+;;;; Access to the Operating System
+
+(uiop/package:define-package :uiop/os
+  (:nicknames :asdf/os)
+  (:recycle :uiop/os :asdf/os :asdf)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility)
+  (:export
+   #:featurep #:os-unix-p #:os-windows-p #:os-genera-p #:detect-os ;; features
+   #:getenv #:getenvp ;; environment variables
+   #:implementation-identifier ;; implementation identifier
+   #:implementation-type #:*implementation-type*
+   #:operating-system #:architecture #:lisp-version-string
+   #:hostname #:getcwd #:chdir
+   ;; Windows shortcut support
+   #:read-null-terminated-string #:read-little-endian
+   #:parse-file-location-info #:parse-windows-shortcut))
+(in-package :uiop/os)
+
+;;; Features
+(with-upgradability ()
+  (defun featurep (x &optional (*features* *features*))
+    (cond
+      ((atom x) (and (member x *features*) t))
+      ((eq :not (car x)) (assert (null (cddr x))) (not (featurep (cadr x))))
+      ((eq :or (car x)) (some #'featurep (cdr x)))
+      ((eq :and (car x)) (every #'featurep (cdr x)))
+      (t (error "Malformed feature specification ~S" x))))
+
+  (defun os-unix-p ()
+    (or #+abcl (featurep :unix)
+        #+(and (not abcl) (or unix cygwin darwin)) t))
+
+  (defun os-windows-p ()
+    (or #+abcl (featurep :windows)
+        #+(and (not (or unix cygwin darwin)) (or win32 windows mswindows mingw32)) t))
+
+  (defun os-genera-p ()
+    (or #+genera t))
+
+  (defun detect-os ()
+    (flet ((yes (yes) (pushnew yes *features*))
+           (no (no) (setf *features* (remove no *features*))))
+      (cond
+        ((os-unix-p) (yes :os-unix) (no :os-windows) (no :genera))
+        ((os-windows-p) (yes :os-windows) (no :os-unix) (no :genera))
+        ((os-genera-p) (no :os-unix) (no :os-windows) (yes :genera))
+        (t (error "Congratulations for trying XCVB on an operating system~%~
+that is neither Unix, nor Windows, nor even Genera.~%Now you port it.")))))
+
+  (detect-os))
+
+;;;; Environment variables: getting them, and parsing them.
+
+(with-upgradability ()
+  (defun getenv (x)
+    (declare (ignorable x))
+    #+(or abcl clisp ecl xcl) (ext:getenv x)
+    #+allegro (sys:getenv x)
+    #+clozure (ccl:getenv x)
+    #+(or cmu scl) (cdr (assoc x ext:*environment-list* :test #'string=))
+    #+cormanlisp
+    (let* ((buffer (ct:malloc 1))
+           (cname (ct:lisp-string-to-c-string x))
+           (needed-size (win:getenvironmentvariable cname buffer 0))
+           (buffer1 (ct:malloc (1+ needed-size))))
+      (prog1 (if (zerop (win:getenvironmentvariable cname buffer1 needed-size))
+                 nil
+                 (ct:c-string-to-lisp-string buffer1))
+        (ct:free buffer)
+        (ct:free buffer1)))
+    #+gcl (system:getenv x)
+    #+genera nil
+    #+lispworks (lispworks:environment-variable x)
+    #+mcl (ccl:with-cstrs ((name x))
+            (let ((value (_getenv name)))
+              (unless (ccl:%null-ptr-p value)
+                (ccl:%get-cstring value))))
+    #+mkcl (#.(or (find-symbol* 'getenv :si nil) (find-symbol* 'getenv :mk-ext nil)) x)
+    #+sbcl (sb-ext:posix-getenv x)
+    #-(or abcl allegro clisp clozure cmu cormanlisp ecl gcl genera lispworks mcl mkcl sbcl scl xcl)
+    (error "~S is not supported on your implementation" 'getenv))
+
+  (defun getenvp (x)
+    "Predicate that is true if the named variable is present in the libc environment,
+then returning the non-empty string value of the variable"
+    (let ((g (getenv x))) (and (not (emptyp g)) g))))
+
+
+;;;; implementation-identifier
+;;
+;; produce a string to identify current implementation.
+;; Initially stolen from SLIME's SWANK, completely rewritten since.
+;; We're back to runtime checking, for the sake of e.g. ABCL.
+
+(with-upgradability ()
+  (defun first-feature (feature-sets)
+    (dolist (x feature-sets)
+      (multiple-value-bind (short long feature-expr)
+          (if (consp x)
+              (values (first x) (second x) (cons :or (rest x)))
+              (values x x x))
+        (when (featurep feature-expr)
+          (return (values short long))))))
+
+  (defun implementation-type ()
+    (first-feature
+     '(:abcl (:acl :allegro) (:ccl :clozure) :clisp (:corman :cormanlisp)
+       (:cmu :cmucl :cmu) :ecl :gcl
+       (:lwpe :lispworks-personal-edition) (:lw :lispworks)
+       :mcl :mkcl :sbcl :scl (:smbx :symbolics) :xcl)))
+
+  (defvar *implementation-type* (implementation-type))
+
+  (defun operating-system ()
+    (first-feature
+     '(:cygwin (:win :windows :mswindows :win32 :mingw32) ;; try cygwin first!
+       (:linux :linux :linux-target) ;; for GCL at least, must appear before :bsd
+       (:macosx :macosx :darwin :darwin-target :apple) ; also before :bsd
+       (:solaris :solaris :sunos) (:bsd :bsd :freebsd :netbsd :openbsd) :unix
+       :genera)))
+
+  (defun architecture ()
+    (first-feature
+     '((:x64 :x86-64 :x86_64 :x8664-target :amd64 (:and :word-size=64 :pc386))
+       (:x86 :x86 :i386 :i486 :i586 :i686 :pentium3 :pentium4 :pc386 :iapx386 :x8632-target)
+       (:ppc64 :ppc64 :ppc64-target) (:ppc32 :ppc32 :ppc32-target :ppc :powerpc)
+       :hppa64 :hppa :sparc64 (:sparc32 :sparc32 :sparc)
+       :mipsel :mipseb :mips :alpha (:arm :arm :arm-target) :imach
+       ;; Java comes last: if someone uses C via CFFI or otherwise JNA or JNI,
+       ;; we may have to segregate the code still by architecture.
+       (:java :java :java-1.4 :java-1.5 :java-1.6 :java-1.7))))
+
+  #+clozure
+  (defun ccl-fasl-version ()
+    ;; the fasl version is target-dependent from CCL 1.8 on.
+    (or (let ((s 'ccl::target-fasl-version))
+          (and (fboundp s) (funcall s)))
+        (and (boundp 'ccl::fasl-version)
+             (symbol-value 'ccl::fasl-version))
+        (error "Can't determine fasl version.")))
+
+  (defun lisp-version-string ()
+    (let ((s (lisp-implementation-version)))
+      (car ; as opposed to OR, this idiom prevents some unreachable code warning
+       (list
+        #+allegro
+        (format nil "~A~@[~A~]~@[~A~]~@[~A~]"
+                excl::*common-lisp-version-number*
+                ;; M means "modern", as opposed to ANSI-compatible mode (which I consider default)
+                (and (eq excl:*current-case-mode* :case-sensitive-lower) "M")
+                ;; Note if not using International ACL
+                ;; see http://www.franz.com/support/documentation/8.1/doc/operators/excl/ics-target-case.htm
+                (excl:ics-target-case (:-ics "8"))
+                (and (member :smp *features*) "S"))
+        #+armedbear (format nil "~a-fasl~a" s system::*fasl-version*)
+        #+clisp
+        (subseq s 0 (position #\space s)) ; strip build information (date, etc.)
+        #+clozure
+        (format nil "~d.~d-f~d" ; shorten for windows
+                ccl::*openmcl-major-version*
+                ccl::*openmcl-minor-version*
+                (logand (ccl-fasl-version) #xFF))
+        #+cmu (substitute #\- #\/ s)
+        #+scl (format nil "~A~A" s
+                      ;; ANSI upper case vs lower case.
+                      (ecase ext:*case-mode* (:upper "") (:lower "l")))
+        #+ecl (format nil "~A~@[-~A~]" s
+                      (let ((vcs-id (ext:lisp-implementation-vcs-id)))
+                        (subseq vcs-id 0 (min (length vcs-id) 8))))
+        #+gcl (subseq s (1+ (position #\space s)))
+        #+genera
+        (multiple-value-bind (major minor) (sct:get-system-version "System")
+          (format nil "~D.~D" major minor))
+        #+mcl (subseq s 8) ; strip the leading "Version "
+        s))))
+
+  (defun implementation-identifier ()
+    (substitute-if
+     #\_ #'(lambda (x) (find x " /:;&^\\|?<>(){}[]$#`'\""))
+     (format nil "~(~a~@{~@[-~a~]~}~)"
+             (or (implementation-type) (lisp-implementation-type))
+             (or (lisp-version-string) (lisp-implementation-version))
+             (or (operating-system) (software-type))
+             (or (architecture) (machine-type))))))
+
+
+;;;; Other system information
+
+(with-upgradability ()
+  (defun hostname ()
+    ;; Note: untested on RMCL
+    #+(or abcl clozure cmu ecl genera lispworks mcl mkcl sbcl scl xcl) (machine-instance)
+    #+cormanlisp "localhost" ;; is there a better way? Does it matter?
+    #+allegro (symbol-call :excl.osi :gethostname)
+    #+clisp (first (split-string (machine-instance) :separator " "))
+    #+gcl (system:gethostname)))
+
+
+;;; Current directory
+(with-upgradability ()
+
+  #+cmu
+  (defun parse-unix-namestring* (unix-namestring)
+    (multiple-value-bind (host device directory name type version)
+        (lisp::parse-unix-namestring unix-namestring 0 (length unix-namestring))
+      (make-pathname :host (or host lisp::*unix-host*) :device device
+                     :directory directory :name name :type type :version version)))
+
+  (defun getcwd ()
+    "Get the current working directory as per POSIX getcwd(3), as a pathname object"
+    (or #+abcl (parse-namestring
+                (java:jstatic "getProperty" "java.lang.System" "user.dir") :ensure-directory t)
+        #+allegro (excl::current-directory)
+        #+clisp (ext:default-directory)
+        #+clozure (ccl:current-directory)
+        #+(or cmu scl) (#+cmu parse-unix-namestring* #+scl lisp::parse-unix-namestring
+                        (strcat (nth-value 1 (unix:unix-current-directory)) "/"))
+        #+cormanlisp (pathname (pl::get-current-directory)) ;; Q: what type does it return?
+        #+ecl (ext:getcwd)
+        #+gcl (parse-namestring ;; this is a joke. Isn't there a better way?
+               (first (symbol-call :uiop :run-program '("/bin/pwd") :output :lines)))
+        #+genera *default-pathname-defaults* ;; on a Lisp OS, it *is* canonical!
+        #+lispworks (system:current-directory)
+        #+mkcl (mk-ext:getcwd)
+        #+sbcl (sb-ext:parse-native-namestring (sb-unix:posix-getcwd/))
+        #+xcl (extensions:current-directory)
+        (error "getcwd not supported on your implementation")))
+
+  (defun chdir (x)
+    "Change current directory, as per POSIX chdir(2), to a given pathname object"
+    (if-let (x (pathname x))
+      (or #+abcl (java:jstatic "setProperty" "java.lang.System" "user.dir" (namestring x))
+          #+allegro (excl:chdir x)
+          #+clisp (ext:cd x)
+          #+clozure (setf (ccl:current-directory) x)
+          #+(or cmu scl) (unix:unix-chdir (ext:unix-namestring x))
+          #+cormanlisp (unless (zerop (win32::_chdir (namestring x)))
+                         (error "Could not set current directory to ~A" x))
+          #+ecl (ext:chdir x)
+          #+genera (setf *default-pathname-defaults* x)
+          #+lispworks (hcl:change-directory x)
+          #+mkcl (mk-ext:chdir x)
+          #+sbcl (symbol-call :sb-posix :chdir (sb-ext:native-namestring x))
+          (error "chdir not supported on your implementation")))))
+
+
+;;;; -----------------------------------------------------------------
+;;;; Windows shortcut support.  Based on:
+;;;;
+;;;; Jesse Hager: The Windows Shortcut File Format.
+;;;; http://www.wotsit.org/list.asp?fc=13
+
+#-(or clisp genera) ; CLISP doesn't need it, and READ-SEQUENCE annoys old Genera.
+(with-upgradability ()
+  (defparameter *link-initial-dword* 76)
+  (defparameter *link-guid* #(1 20 2 0 0 0 0 0 192 0 0 0 0 0 0 70))
+
+  (defun read-null-terminated-string (s)
+    (with-output-to-string (out)
+      (loop :for code = (read-byte s)
+            :until (zerop code)
+            :do (write-char (code-char code) out))))
+
+  (defun read-little-endian (s &optional (bytes 4))
+    (loop :for i :from 0 :below bytes
+          :sum (ash (read-byte s) (* 8 i))))
+
+  (defun parse-file-location-info (s)
+    (let ((start (file-position s))
+          (total-length (read-little-endian s))
+          (end-of-header (read-little-endian s))
+          (fli-flags (read-little-endian s))
+          (local-volume-offset (read-little-endian s))
+          (local-offset (read-little-endian s))
+          (network-volume-offset (read-little-endian s))
+          (remaining-offset (read-little-endian s)))
+      (declare (ignore total-length end-of-header local-volume-offset))
+      (unless (zerop fli-flags)
+        (cond
+          ((logbitp 0 fli-flags)
+           (file-position s (+ start local-offset)))
+          ((logbitp 1 fli-flags)
+           (file-position s (+ start
+                               network-volume-offset
+                               #x14))))
+        (strcat (read-null-terminated-string s)
                 (progn
-                  (when force-relative
-                    (error "absolute pathname designator not allowed: ~S" s))
-                  (values :absolute (cdr components)))
-                (values :relative nil))
-          (values :relative components))
-      (setf components (remove "" components :test #'equal))
+                  (file-position s (+ start remaining-offset))
+                  (read-null-terminated-string s))))))
+
+  (defun parse-windows-shortcut (pathname)
+    (with-open-file (s pathname :element-type '(unsigned-byte 8))
+      (handler-case
+          (when (and (= (read-little-endian s) *link-initial-dword*)
+                     (let ((header (make-array (length *link-guid*))))
+                       (read-sequence header s)
+                       (equalp header *link-guid*)))
+            (let ((flags (read-little-endian s)))
+              (file-position s 76)        ;skip rest of header
+              (when (logbitp 0 flags)
+                ;; skip shell item id list
+                (let ((length (read-little-endian s 2)))
+                  (file-position s (+ length (file-position s)))))
+              (cond
+                ((logbitp 1 flags)
+                 (parse-file-location-info s))
+                (t
+                 (when (logbitp 2 flags)
+                   ;; skip description string
+                   (let ((length (read-little-endian s 2)))
+                     (file-position s (+ length (file-position s)))))
+                 (when (logbitp 3 flags)
+                   ;; finally, our pathname
+                   (let* ((length (read-little-endian s 2))
+                          (buffer (make-array length)))
+                     (read-sequence buffer s)
+                     (map 'string #'code-char buffer)))))))
+        (end-of-file (c)
+          (declare (ignore c))
+          nil)))))
+
+
+;;;; -------------------------------------------------------------------------
+;;;; Portability layer around Common Lisp pathnames
+;; This layer allows for portable manipulation of pathname objects themselves,
+;; which all is necessary prior to any access the filesystem or environment.
+
+(uiop/package:define-package :uiop/pathname
+  (:nicknames :asdf/pathname)
+  (:recycle :uiop/pathname :asdf/pathname :asdf)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility :uiop/os)
+  (:export
+   ;; Making and merging pathnames, portably
+   #:normalize-pathname-directory-component #:denormalize-pathname-directory-component
+   #:merge-pathname-directory-components #:*unspecific-pathname-type* #:make-pathname*
+   #:make-pathname-component-logical #:make-pathname-logical
+   #:merge-pathnames*
+   #:nil-pathname #:*nil-pathname* #:with-pathname-defaults
+   ;; Predicates
+   #:pathname-equal #:logical-pathname-p #:physical-pathname-p
+   #:absolute-pathname-p #:relative-pathname-p #:hidden-pathname-p #:file-pathname-p
+   ;; Directories
+   #:pathname-directory-pathname #:pathname-parent-directory-pathname
+   #:directory-pathname-p #:ensure-directory-pathname
+   ;; Parsing filenames
+   #:component-name-to-pathname-components
+   #:split-name-type #:parse-unix-namestring #:unix-namestring
+   #:split-unix-namestring-directory-components
+   ;; Absolute and relative pathnames
+   #:subpathname #:subpathname*
+   #:ensure-absolute-pathname
+   #:pathname-root #:pathname-host-pathname
+   #:subpathp
+   ;; Checking constraints
+   #:ensure-pathname ;; implemented in filesystem.lisp to accommodate for existence constraints
+   ;; Wildcard pathnames
+   #:*wild* #:*wild-file* #:*wild-directory* #:*wild-inferiors* #:*wild-path* #:wilden
+   ;; Translate a pathname
+   #:relativize-directory-component #:relativize-pathname-directory
+   #:directory-separator-for-host #:directorize-pathname-host-device
+   #:translate-pathname*
+   #:*output-translation-function*))
+(in-package :uiop/pathname)
+
+;;; Normalizing pathnames across implementations
+
+(with-upgradability ()
+  (defun normalize-pathname-directory-component (directory)
+    "Given a pathname directory component, return an equivalent form that is a list"
+    #+gcl2.6 (setf directory (substitute :back :parent directory))
+    (cond
+      #-(or cmu sbcl scl) ;; these implementations already normalize directory components.
+      ((stringp directory) `(:absolute ,directory))
+      #+gcl2.6
+      ((and (consp directory) (eq :root (first directory)))
+       `(:absolute ,@(rest directory)))
+      ((or (null directory)
+           (and (consp directory) (member (first directory) '(:absolute :relative))))
+       directory)
+      #+gcl2.6
+      ((consp directory)
+       `(:relative ,@directory))
+      (t
+       (error (compatfmt "~@<Unrecognized pathname directory component ~S~@:>") directory))))
+
+  (defun denormalize-pathname-directory-component (directory-component)
+    #-gcl2.6 directory-component
+    #+gcl2.6
+    (let ((d (substitute-if :parent (lambda (x) (member x '(:up :back)))
+                            directory-component)))
       (cond
-        ((equal last-comp "")
-         (values relative components nil)) ; "" already removed
-        (force-directory
-         (values relative components nil))
-        (t
-         (values relative (butlast components) last-comp))))))
-
-(defun* remove-keys (key-names args)
-  (loop :for (name val) :on args :by #'cddr
-    :unless (member (symbol-name name) key-names
-                    :key #'symbol-name :test 'equal)
-    :append (list name val)))
-
-(defun* remove-keyword (key args)
-  (loop :for (k v) :on args :by #'cddr
-    :unless (eq k key)
-    :append (list k v)))
-
-(defun* getenv (x)
-  (#+(or abcl clisp) ext:getenv
-   #+allegro sys:getenv
-   #+clozure ccl:getenv
-   #+(or cmu scl) (lambda (x) (cdr (assoc x ext:*environment-list* :test #'string=)))
-   #+ecl si:getenv
-   #+gcl system:getenv
-   #+lispworks lispworks:environment-variable
-   #+sbcl sb-ext:posix-getenv
-   x))
-
-(defun* directory-pathname-p (pathname)
-  "Does PATHNAME represent a directory?
+        ((and (consp d) (eq :relative (first d))) (rest d))
+        ((and (consp d) (eq :absolute (first d))) `(:root ,@(rest d)))
+        (t d))))
+
+  (defun merge-pathname-directory-components (specified defaults)
+    ;; Helper for merge-pathnames* that handles directory components.
+    (let ((directory (normalize-pathname-directory-component specified)))
+      (ecase (first directory)
+        ((nil) defaults)
+        (:absolute specified)
+        (:relative
+         (let ((defdir (normalize-pathname-directory-component defaults))
+               (reldir (cdr directory)))
+           (cond
+             ((null defdir)
+              directory)
+             ((not (eq :back (first reldir)))
+              (append defdir reldir))
+             (t
+              (loop :with defabs = (first defdir)
+                    :with defrev = (reverse (rest defdir))
+                    :while (and (eq :back (car reldir))
+                                (or (and (eq :absolute defabs) (null defrev))
+                                    (stringp (car defrev))))
+                    :do (pop reldir) (pop defrev)
+                    :finally (return (cons defabs (append (reverse defrev) reldir)))))))))))
+
+  ;; Giving :unspecific as :type argument to make-pathname is not portable.
+  ;; See CLHS make-pathname and 19.2.2.2.3.
+  ;; This will be :unspecific if supported, or NIL if not.
+  (defparameter *unspecific-pathname-type*
+    #+(or abcl allegro clozure cmu gcl genera lispworks mkcl sbcl scl xcl) :unspecific
+    #+(or clisp ecl #|These haven't been tested:|# cormanlisp mcl) nil)
+
+  (defun make-pathname* (&rest keys &key (directory nil #+gcl2.6 directoryp)
+                                      host (device () #+allegro devicep) name type version defaults
+                                      #+scl &allow-other-keys)
+    "Takes arguments like CL:MAKE-PATHNAME in the CLHS, and
+   tries hard to make a pathname that will actually behave as documented,
+   despite the peculiarities of each implementation"
+    (declare (ignorable host device directory name type version defaults))
+    (apply 'make-pathname
+           (append
+            #+allegro (when (and devicep (null device)) `(:device :unspecific))
+            #+gcl2.6
+            (when directoryp
+              `(:directory ,(denormalize-pathname-directory-component directory)))
+            keys)))
+
+  (defun make-pathname-component-logical (x)
+    "Make a pathname component suitable for use in a logical-pathname"
+    (typecase x
+      ((eql :unspecific) nil)
+      #+clisp (string (string-upcase x))
+      #+clisp (cons (mapcar 'make-pathname-component-logical x))
+      (t x)))
+
+  (defun make-pathname-logical (pathname host)
+    "Take a PATHNAME's directory, name, type and version components,
+and make a new pathname with corresponding components and specified logical HOST"
+    (make-pathname*
+     :host host
+     :directory (make-pathname-component-logical (pathname-directory pathname))
+     :name (make-pathname-component-logical (pathname-name pathname))
+     :type (make-pathname-component-logical (pathname-type pathname))
+     :version (make-pathname-component-logical (pathname-version pathname))))
+
+  (defun merge-pathnames* (specified &optional (defaults *default-pathname-defaults*))
+    "MERGE-PATHNAMES* is like MERGE-PATHNAMES except that
+if the SPECIFIED pathname does not have an absolute directory,
+then the HOST and DEVICE both come from the DEFAULTS, whereas
+if the SPECIFIED pathname does have an absolute directory,
+then the HOST and DEVICE both come from the SPECIFIED.
+This is what users want on a modern Unix or Windows operating system,
+unlike the MERGE-PATHNAME behavior.
+Also, if either argument is NIL, then the other argument is returned unmodified;
+this is unlike MERGE-PATHNAME which always merges with a pathname,
+by default *DEFAULT-PATHNAME-DEFAULTS*, which cannot be NIL."
+    (when (null specified) (return-from merge-pathnames* defaults))
+    (when (null defaults) (return-from merge-pathnames* specified))
+    #+scl
+    (ext:resolve-pathname specified defaults)
+    #-scl
+    (let* ((specified (pathname specified))
+           (defaults (pathname defaults))
+           (directory (normalize-pathname-directory-component (pathname-directory specified)))
+           (name (or (pathname-name specified) (pathname-name defaults)))
+           (type (or (pathname-type specified) (pathname-type defaults)))
+           (version (or (pathname-version specified) (pathname-version defaults))))
+      (labels ((unspecific-handler (p)
+                 (if (typep p 'logical-pathname) #'make-pathname-component-logical #'identity)))
+        (multiple-value-bind (host device directory unspecific-handler)
+            (ecase (first directory)
+              ((:absolute)
+               (values (pathname-host specified)
+                       (pathname-device specified)
+                       directory
+                       (unspecific-handler specified)))
+              ((nil :relative)
+               (values (pathname-host defaults)
+                       (pathname-device defaults)
+                       (merge-pathname-directory-components directory (pathname-directory defaults))
+                       (unspecific-handler defaults))))
+          (make-pathname* :host host :device device :directory directory
+                          :name (funcall unspecific-handler name)
+                          :type (funcall unspecific-handler type)
+                          :version (funcall unspecific-handler version))))))
+
+  (defun nil-pathname (&optional (defaults *default-pathname-defaults*))
+    "A pathname that is as neutral as possible for use as defaults
+   when merging, making or parsing pathnames"
+    ;; 19.2.2.2.1 says a NIL host can mean a default host;
+    ;; see also "valid physical pathname host" in the CLHS glossary, that suggests
+    ;; strings and lists of strings or :unspecific
+    ;; But CMUCL decides to die on NIL.
+    #.`(make-pathname* :directory nil :name nil :type nil :version nil :device nil
+                       :host (or #+cmu lisp::*unix-host*)
+                       #+scl ,@'(:scheme nil :scheme-specific-part nil
+                                 :username nil :password nil :parameters nil :query nil :fragment nil)
+                       ;; the default shouldn't matter, but we really want something physical
+                       :defaults defaults))
+
+  (defvar *nil-pathname* (nil-pathname (translate-logical-pathname (user-homedir-pathname))))
+
+  (defmacro with-pathname-defaults ((&optional defaults) &body body)
+    `(let ((*default-pathname-defaults* ,(or defaults '*nil-pathname*))) ,@body)))
+
+
+;;; Some pathname predicates
+(with-upgradability ()
+  (defun pathname-equal (p1 p2)
+    (when (stringp p1) (setf p1 (pathname p1)))
+    (when (stringp p2) (setf p2 (pathname p2)))
+    (flet ((normalize-component (x)
+             (unless (member x '(nil :unspecific :newest (:relative)) :test 'equal)
+               x)))
+      (macrolet ((=? (&rest accessors)
+                   (flet ((frob (x)
+                            (reduce 'list (cons 'normalize-component accessors)
+                                    :initial-value x :from-end t)))
+                     `(equal ,(frob 'p1) ,(frob 'p2)))))
+        (or (and (null p1) (null p2))
+            (and (pathnamep p1) (pathnamep p2)
+                 (and (=? pathname-host)
+                      (=? pathname-device)
+                      (=? normalize-pathname-directory-component pathname-directory)
+                      (=? pathname-name)
+                      (=? pathname-type)
+                      (=? pathname-version)))))))
+
+  (defun logical-pathname-p (x)
+    (typep x 'logical-pathname))
+
+  (defun physical-pathname-p (x)
+    (and (pathnamep x) (not (logical-pathname-p x))))
+
+  (defun absolute-pathname-p (pathspec)
+    "If PATHSPEC is a pathname or namestring object that parses as a pathname
+possessing an :ABSOLUTE directory component, return the (parsed) pathname.
+Otherwise return NIL"
+    (and pathspec
+         (typep pathspec '(or null pathname string))
+         (let ((pathname (pathname pathspec)))
+           (and (eq :absolute (car (normalize-pathname-directory-component
+                                    (pathname-directory pathname))))
+                pathname))))
+
+  (defun relative-pathname-p (pathspec)
+    "If PATHSPEC is a pathname or namestring object that parses as a pathname
+possessing a :RELATIVE or NIL directory component, return the (parsed) pathname.
+Otherwise return NIL"
+    (and pathspec
+         (typep pathspec '(or null pathname string))
+         (let* ((pathname (pathname pathspec))
+                (directory (normalize-pathname-directory-component
+                            (pathname-directory pathname))))
+           (when (or (null directory) (eq :relative (car directory)))
+             pathname))))
+
+  (defun hidden-pathname-p (pathname)
+    "Return a boolean that is true if the pathname is hidden as per Unix style,
+i.e. its name starts with a dot."
+    (and pathname (equal (first-char (pathname-name pathname)) #\.)))
+
+  (defun file-pathname-p (pathname)
+    "Does PATHNAME represent a file, i.e. has a non-null NAME component?
+
+Accepts NIL, a string (converted through PARSE-NAMESTRING) or a PATHNAME.
+
+Note that this does _not_ check to see that PATHNAME points to an
+actually-existing file.
+
+Returns the (parsed) PATHNAME when true"
+    (when pathname
+      (let* ((pathname (pathname pathname))
+             (name (pathname-name pathname)))
+        (when (not (member name '(nil :unspecific "") :test 'equal))
+          pathname)))))
+
+
+;;; Directory pathnames
+(with-upgradability ()
+  (defun pathname-directory-pathname (pathname)
+    "Returns a new pathname with same HOST, DEVICE, DIRECTORY as PATHNAME,
+and NIL NAME, TYPE and VERSION components"
+    (when pathname
+      (make-pathname :name nil :type nil :version nil :defaults pathname)))
+
+  (defun pathname-parent-directory-pathname (pathname)
+    "Returns a new pathname that corresponds to the parent of the current pathname's directory,
+i.e. removing one level of depth in the DIRECTORY component. e.g. if pathname is
+Unix pathname /foo/bar/baz/file.type then return /foo/bar/"
+    (when pathname
+      (make-pathname* :name nil :type nil :version nil
+                      :directory (merge-pathname-directory-components
+                                  '(:relative :back) (pathname-directory pathname))
+                      :defaults pathname)))
+
+  (defun directory-pathname-p (pathname)
+    "Does PATHNAME represent a directory?
 
 A directory-pathname is a pathname _without_ a filename. The three
 ways that the filename components can be missing are for it to be NIL,
@@ -573,619 +2097,3969 @@
 
 Note that this does _not_ check to see that PATHNAME points to an
 actually-existing directory."
-  (when pathname
-    (let ((pathname (pathname pathname)))
-      (flet ((check-one (x)
-               (member x '(nil :unspecific "") :test 'equal)))
-        (and (not (wild-pathname-p pathname))
-             (check-one (pathname-name pathname))
-             (check-one (pathname-type pathname))
-             t)))))
-
-(defun* ensure-directory-pathname (pathspec)
-  "Converts the non-wild pathname designator PATHSPEC to directory form."
-  (cond
-   ((stringp pathspec)
-    (ensure-directory-pathname (pathname pathspec)))
-   ((not (pathnamep pathspec))
-    (error "Invalid pathname designator ~S" pathspec))
-   ((wild-pathname-p pathspec)
-    (error "Can't reliably convert wild pathname ~S" pathspec))
-   ((directory-pathname-p pathspec)
-    pathspec)
-   (t
-    (make-pathname :directory (append (or (pathname-directory pathspec)
-                                          (list :relative))
-                                      (list (file-namestring pathspec)))
-                   :name nil :type nil :version nil
-                   :defaults pathspec))))
-
-(defun* absolute-pathname-p (pathspec)
-  (and (typep pathspec '(or pathname string))
-       (eq :absolute (car (pathname-directory (pathname pathspec))))))
-
-(defun* length=n-p (x n) ;is it that (= (length x) n) ?
-  (check-type n (integer 0 *))
-  (loop
-    :for l = x :then (cdr l)
-    :for i :downfrom n :do
+    (when pathname
+      (let ((pathname (pathname pathname)))
+        (flet ((check-one (x)
+                 (member x '(nil :unspecific "") :test 'equal)))
+          (and (not (wild-pathname-p pathname))
+               (check-one (pathname-name pathname))
+               (check-one (pathname-type pathname))
+               t)))))
+
+  (defun ensure-directory-pathname (pathspec &optional (on-error 'error))
+    "Converts the non-wild pathname designator PATHSPEC to directory form."
     (cond
-      ((zerop i) (return (null l)))
-      ((not (consp l)) (return nil)))))
-
-(defun* ends-with (s suffix)
-  (check-type s string)
-  (check-type suffix string)
-  (let ((start (- (length s) (length suffix))))
-    (and (<= 0 start)
-         (string-equal s suffix :start1 start))))
-
-(defun* read-file-forms (file)
-  (with-open-file (in file)
-    (loop :with eof = (list nil)
-     :for form = (read in nil eof)
-     :until (eq form eof)
-     :collect form)))
-
-#-(and (or win32 windows mswindows mingw32) (not cygwin))
-(progn
-  #+ecl #.(cl:and (cl:< ext:+ecl-version-number+ 100601)
-                  '(ffi:clines "#include <sys/types.h>" "#include <unistd.h>"))
-  (defun* get-uid ()
-    #+allegro (excl.osi:getuid)
-    #+clisp (loop :for s :in '("posix:uid" "LINUX:getuid")
-                  :for f = (ignore-errors (read-from-string s))
-                  :when f :return (funcall f))
-    #+(or cmu scl) (unix:unix-getuid)
-    #+ecl #.(cl:if (cl:< ext:+ecl-version-number+ 100601)
-                   '(ffi:c-inline () () :int "getuid()" :one-liner t)
-                   '(ext::getuid))
-    #+sbcl (sb-unix:unix-getuid)
-    #-(or allegro clisp cmu ecl sbcl scl)
-    (let ((uid-string
-           (with-output-to-string (*verbose-out*)
-             (run-shell-command "id -ur"))))
-      (with-input-from-string (stream uid-string)
-        (read-line stream)
-        (handler-case (parse-integer (read-line stream))
-          (error () (error "Unable to find out user ID")))))))
-
-(defun* pathname-root (pathname)
-  (make-pathname :host (pathname-host pathname)
-                 :device (pathname-device pathname)
-                 :directory '(:absolute)
-                 :name nil :type nil :version nil))
-
-(defun* find-symbol* (s p)
-  (find-symbol (string s) p))
-
-(defun* probe-file* (p)
-  "when given a pathname P, probes the filesystem for a file or directory
-with given pathname and if it exists return its truename."
-  (etypecase p
-   (null nil)
-   (string (probe-file* (parse-namestring p)))
-   (pathname (unless (wild-pathname-p p)
-               #.(or #+(or allegro clozure cmu ecl sbcl scl) '(probe-file p)
-               #+clisp (aif (find-symbol (string '#:probe-pathname) :ext) `(ignore-errors (,it p)))
-               '(ignore-errors (truename p)))))))
-
-(defun* truenamize (p)
-  "Resolve as much of a pathname as possible"
-  (block nil
-    (when (typep p 'logical-pathname) (return p))
-    (let* ((p (merge-pathnames* p))
-           (directory (pathname-directory p)))
-      (when (typep p 'logical-pathname) (return p))
-      (let ((found (probe-file* p)))
-        (when found (return found)))
-      #-(or sbcl cmu) (when (stringp directory) (return p))
-      (when (not (eq :absolute (car directory))) (return p))
-      (let ((sofar (probe-file* (pathname-root p))))
-        (unless sofar (return p))
-        (flet ((solution (directories)
-                 (merge-pathnames*
-                  (make-pathname :host nil :device nil
-                                 :directory `(:relative ,@directories)
-                                 :name (pathname-name p)
-                                 :type (pathname-type p)
-                                 :version (pathname-version p))
-                  sofar)))
-          (loop :for component :in (cdr directory)
-            :for rest :on (cdr directory)
-            :for more = (probe-file*
-                         (merge-pathnames*
-                          (make-pathname :directory `(:relative ,component))
-                          sofar)) :do
-            (if more
-                (setf sofar more)
-                (return (solution rest)))
-            :finally
-            (return (solution nil))))))))
-
-(defun* resolve-symlinks (path)
-  #-allegro (truenamize path)
-  #+allegro (excl:pathname-resolve-symbolic-links path))
-
-(defun* default-directory ()
-  (truenamize (pathname-directory-pathname *default-pathname-defaults*)))
-
-(defun* lispize-pathname (input-file)
-  (make-pathname :type "lisp" :defaults input-file))
-
-(defparameter *wild-path*
-  (make-pathname :directory '(:relative :wild-inferiors)
-                 :name :wild :type :wild :version :wild))
-
-(defun* wilden (path)
-  (merge-pathnames* *wild-path* path))
-
-(defun* directorize-pathname-host-device (pathname)
-  (let* ((root (pathname-root pathname))
-         (wild-root (wilden root))
-         (absolute-pathname (merge-pathnames* pathname root))
-         (foo (make-pathname :directory '(:absolute "FOO") :defaults root))
-         (separator (last-char (namestring foo)))
-         (root-namestring (namestring root))
-         (root-string
-          (substitute-if #\/
-                         (lambda (x) (or (eql x #\:)
-                                         (eql x separator)))
-                         root-namestring)))
-    (multiple-value-bind (relative path filename)
-        (component-name-to-pathname-components root-string :force-directory t)
-      (declare (ignore relative filename))
-      (let ((new-base
-             (make-pathname :defaults root
-                            :directory `(:absolute ,@path))))
-        (translate-pathname absolute-pathname wild-root (wilden new-base))))))
+      ((stringp pathspec)
+       (ensure-directory-pathname (pathname pathspec)))
+      ((not (pathnamep pathspec))
+       (call-function on-error (compatfmt "~@<Invalid pathname designator ~S~@:>") pathspec))
+      ((wild-pathname-p pathspec)
+       (call-function on-error (compatfmt "~@<Can't reliably convert wild pathname ~3i~_~S~@:>") pathspec))
+      ((directory-pathname-p pathspec)
+       pathspec)
+      (t
+       (make-pathname* :directory (append (or (normalize-pathname-directory-component
+                                               (pathname-directory pathspec))
+                                              (list :relative))
+                                          (list (file-namestring pathspec)))
+                       :name nil :type nil :version nil :defaults pathspec)))))
+
+
+;;; Parsing filenames
+(with-upgradability ()
+  (defun split-unix-namestring-directory-components
+      (unix-namestring &key ensure-directory dot-dot)
+    "Splits the path string UNIX-NAMESTRING, returning four values:
+A flag that is either :absolute or :relative, indicating
+   how the rest of the values are to be interpreted.
+A directory path --- a list of strings and keywords, suitable for
+   use with MAKE-PATHNAME when prepended with the flag value.
+   Directory components with an empty name or the name . are removed.
+   Any directory named .. is read as DOT-DOT, or :BACK if it's NIL (not :UP).
+A last-component, either a file-namestring including type extension,
+   or NIL in the case of a directory pathname.
+A flag that is true iff the unix-style-pathname was just
+   a file-namestring without / path specification.
+ENSURE-DIRECTORY forces the namestring to be interpreted as a directory pathname:
+the third return value will be NIL, and final component of the namestring
+will be treated as part of the directory path.
+
+An empty string is thus read as meaning a pathname object with all fields nil.
+
+Note that : characters will NOT be interpreted as host specification.
+Absolute pathnames are only appropriate on Unix-style systems.
+
+The intention of this function is to support structured component names,
+e.g., \(:file \"foo/bar\"\), which will be unpacked to relative pathnames."
+    (check-type unix-namestring string)
+    (check-type dot-dot (member nil :back :up))
+    (if (and (not (find #\/ unix-namestring)) (not ensure-directory)
+             (plusp (length unix-namestring)))
+        (values :relative () unix-namestring t)
+        (let* ((components (split-string unix-namestring :separator "/"))
+               (last-comp (car (last components))))
+          (multiple-value-bind (relative components)
+              (if (equal (first components) "")
+                  (if (equal (first-char unix-namestring) #\/)
+                      (values :absolute (cdr components))
+                      (values :relative nil))
+                  (values :relative components))
+            (setf components (remove-if #'(lambda (x) (member x '("" ".") :test #'equal))
+                                        components))
+            (setf components (substitute (or dot-dot :back) ".." components :test #'equal))
+            (cond
+              ((equal last-comp "")
+               (values relative components nil nil)) ; "" already removed from components
+              (ensure-directory
+               (values relative components nil nil))
+              (t
+               (values relative (butlast components) last-comp nil)))))))
+
+  (defun split-name-type (filename)
+    "Split a filename into two values NAME and TYPE that are returned.
+We assume filename has no directory component.
+The last . if any separates name and type from from type,
+except that if there is only one . and it is in first position,
+the whole filename is the NAME with an empty type.
+NAME is always a string.
+For an empty type, *UNSPECIFIC-PATHNAME-TYPE* is returned."
+    (check-type filename string)
+    (assert (plusp (length filename)))
+    (destructuring-bind (name &optional (type *unspecific-pathname-type*))
+        (split-string filename :max 2 :separator ".")
+      (if (equal name "")
+          (values filename *unspecific-pathname-type*)
+          (values name type))))
+
+  (defun parse-unix-namestring (name &rest keys &key type defaults dot-dot ensure-directory
+                                &allow-other-keys)
+    "Coerce NAME into a PATHNAME using standard Unix syntax.
+
+Unix syntax is used whether or not the underlying system is Unix;
+on such non-Unix systems it is only usable but for relative pathnames;
+but especially to manipulate relative pathnames portably, it is of crucial
+to possess a portable pathname syntax independent of the underlying OS.
+This is what PARSE-UNIX-NAMESTRING provides, and why we use it in ASDF.
+
+When given a PATHNAME object, just return it untouched.
+When given NIL, just return NIL.
+When given a non-null SYMBOL, first downcase its name and treat it as a string.
+When given a STRING, portably decompose it into a pathname as below.
+
+#\\/ separates directory components.
+
+The last #\\/-separated substring is interpreted as follows:
+1- If TYPE is :DIRECTORY or ENSURE-DIRECTORY is true,
+ the string is made the last directory component, and NAME and TYPE are NIL.
+ if the string is empty, it's the empty pathname with all slots NIL.
+2- If TYPE is NIL, the substring is file-namestring, and its NAME and TYPE
+ are separated by SPLIT-NAME-TYPE.
+3- If TYPE is a string, it is the given TYPE, and the whole string is the NAME.
+
+Directory components with an empty name the name . are removed.
+Any directory named .. is read as DOT-DOT,
+which must be one of :BACK or :UP and defaults to :BACK.
+
+HOST, DEVICE and VERSION components are taken from DEFAULTS,
+which itself defaults to *NIL-PATHNAME*, also used if DEFAULTS in NIL.
+No host or device can be specified in the string itself,
+which makes it unsuitable for absolute pathnames outside Unix.
+
+For relative pathnames, these components (and hence the defaults) won't matter
+if you use MERGE-PATHNAMES* but will matter if you use MERGE-PATHNAMES,
+which is an important reason to always use MERGE-PATHNAMES*.
+
+Arbitrary keys are accepted, and the parse result is passed to ENSURE-PATHNAME
+with those keys, removing TYPE DEFAULTS and DOT-DOT.
+When you're manipulating pathnames that are supposed to make sense portably
+even though the OS may not be Unixish, we recommend you use :WANT-RELATIVE T
+to throw an error if the pathname is absolute"
+    (block nil
+      (check-type type (or null string (eql :directory)))
+      (when ensure-directory
+        (setf type :directory))
+      (etypecase name
+        ((or null pathname) (return name))
+        (symbol
+         (setf name (string-downcase name)))
+        (string))
+      (multiple-value-bind (relative path filename file-only)
+          (split-unix-namestring-directory-components
+           name :dot-dot dot-dot :ensure-directory (eq type :directory))
+        (multiple-value-bind (name type)
+            (cond
+              ((or (eq type :directory) (null filename))
+               (values nil nil))
+              (type
+               (values filename type))
+              (t
+               (split-name-type filename)))
+          (apply 'ensure-pathname
+                 (make-pathname*
+                  :directory (unless file-only (cons relative path))
+                  :name name :type type
+                  :defaults (or defaults *nil-pathname*))
+                 (remove-plist-keys '(:type :dot-dot :defaults) keys))))))
+
+  (defun unix-namestring (pathname)
+    "Given a non-wild PATHNAME, return a Unix-style namestring for it.
+If the PATHNAME is NIL or a STRING, return it unchanged.
+
+This only considers the DIRECTORY, NAME and TYPE components of the pathname.
+This is a portable solution for representing relative pathnames,
+But unless you are running on a Unix system, it is not a general solution
+to representing native pathnames.
+
+An error is signaled if the argument is not NULL, a STRING or a PATHNAME,
+or if it is a PATHNAME but some of its components are not recognized."
+    (etypecase pathname
+      ((or null string) pathname)
+      (pathname
+       (with-output-to-string (s)
+         (flet ((err () (error "Not a valid unix-namestring ~S" pathname)))
+           (let* ((dir (normalize-pathname-directory-component (pathname-directory pathname)))
+                  (name (pathname-name pathname))
+                  (type (pathname-type pathname))
+                  (type (and (not (eq type :unspecific)) type)))
+             (cond
+               ((eq dir ()))
+               ((eq dir '(:relative)) (princ "./" s))
+               ((consp dir)
+                (destructuring-bind (relabs &rest dirs) dir
+                  (or (member relabs '(:relative :absolute)) (err))
+                  (when (eq relabs :absolute) (princ #\/ s))
+                  (loop :for x :in dirs :do
+                    (cond
+                      ((member x '(:back :up)) (princ "../" s))
+                      ((equal x "") (err))
+                      ;;((member x '("." "..") :test 'equal) (err))
+                      ((stringp x) (format s "~A/" x))
+                      (t (err))))))
+               (t (err)))
+             (cond
+               (name
+                (or (and (stringp name) (or (null type) (stringp type))) (err))
+                (format s "~A~@[.~A~]" name type))
+               (t
+                (or (null type) (err)))))))))))
+
+;;; Absolute and relative pathnames
+(with-upgradability ()
+  (defun subpathname (pathname subpath &key type)
+    "This function takes a PATHNAME and a SUBPATH and a TYPE.
+If SUBPATH is already a PATHNAME object (not namestring),
+and is an absolute pathname at that, it is returned unchanged;
+otherwise, SUBPATH is turned into a relative pathname with given TYPE
+as per PARSE-UNIX-NAMESTRING with :WANT-RELATIVE T :TYPE TYPE,
+then it is merged with the PATHNAME-DIRECTORY-PATHNAME of PATHNAME."
+    (or (and (pathnamep subpath) (absolute-pathname-p subpath))
+        (merge-pathnames* (parse-unix-namestring subpath :type type :want-relative t)
+                          (pathname-directory-pathname pathname))))
+
+  (defun subpathname* (pathname subpath &key type)
+    "returns NIL if the base pathname is NIL, otherwise like SUBPATHNAME."
+    (and pathname
+         (subpathname (ensure-directory-pathname pathname) subpath :type type)))
+
+  (defun pathname-root (pathname)
+    (make-pathname* :directory '(:absolute)
+                    :name nil :type nil :version nil
+                    :defaults pathname ;; host device, and on scl, *some*
+                    ;; scheme-specific parts: port username password, not others:
+                    . #.(or #+scl '(:parameters nil :query nil :fragment nil))))
+
+  (defun pathname-host-pathname (pathname)
+    (make-pathname* :directory nil
+                    :name nil :type nil :version nil :device nil
+                    :defaults pathname ;; host device, and on scl, *some*
+                    ;; scheme-specific parts: port username password, not others:
+                    . #.(or #+scl '(:parameters nil :query nil :fragment nil))))
+
+  (defun subpathp (maybe-subpath base-pathname)
+    (and (pathnamep maybe-subpath) (pathnamep base-pathname)
+         (absolute-pathname-p maybe-subpath) (absolute-pathname-p base-pathname)
+         (directory-pathname-p base-pathname) (not (wild-pathname-p base-pathname))
+         (pathname-equal (pathname-root maybe-subpath) (pathname-root base-pathname))
+         (with-pathname-defaults ()
+           (let ((enough (enough-namestring maybe-subpath base-pathname)))
+             (and (relative-pathname-p enough) (pathname enough))))))
+
+  (defun ensure-absolute-pathname (path &optional defaults (on-error 'error))
+    (cond
+      ((absolute-pathname-p path))
+      ((stringp path) (ensure-absolute-pathname (pathname path) defaults on-error))
+      ((not (pathnamep path)) (call-function on-error "not a valid pathname designator ~S" path))
+      ((let ((default-pathname (if (pathnamep defaults) defaults (call-function defaults))))
+         (or (if (absolute-pathname-p default-pathname)
+                 (absolute-pathname-p (merge-pathnames* path default-pathname))
+                 (call-function on-error "Default pathname ~S is not an absolute pathname"
+                                default-pathname))
+             (call-function on-error "Failed to merge ~S with ~S into an absolute pathname"
+                            path default-pathname))))
+      (t (call-function on-error
+                        "Cannot ensure ~S is evaluated as an absolute pathname with defaults ~S"
+                        path defaults)))))
+
+
+;;; Wildcard pathnames
+(with-upgradability ()
+  (defparameter *wild* (or #+cormanlisp "*" :wild))
+  (defparameter *wild-directory-component* (or #+gcl2.6 "*" :wild))
+  (defparameter *wild-inferiors-component* (or #+gcl2.6 "**" :wild-inferiors))
+  (defparameter *wild-file*
+    (make-pathname :directory nil :name *wild* :type *wild*
+                   :version (or #-(or allegro abcl xcl) *wild*)))
+  (defparameter *wild-directory*
+    (make-pathname* :directory `(:relative ,*wild-directory-component*)
+                    :name nil :type nil :version nil))
+  (defparameter *wild-inferiors*
+    (make-pathname* :directory `(:relative ,*wild-inferiors-component*)
+                    :name nil :type nil :version nil))
+  (defparameter *wild-path*
+    (merge-pathnames* *wild-file* *wild-inferiors*))
+
+  (defun wilden (path)
+    (merge-pathnames* *wild-path* path)))
+
+
+;;; Translate a pathname
+(with-upgradability ()
+  (defun relativize-directory-component (directory-component)
+    (let ((directory (normalize-pathname-directory-component directory-component)))
+      (cond
+        ((stringp directory)
+         (list :relative directory))
+        ((eq (car directory) :absolute)
+         (cons :relative (cdr directory)))
+        (t
+         directory))))
+
+  (defun relativize-pathname-directory (pathspec)
+    (let ((p (pathname pathspec)))
+      (make-pathname*
+       :directory (relativize-directory-component (pathname-directory p))
+       :defaults p)))
+
+  (defun directory-separator-for-host (&optional (pathname *default-pathname-defaults*))
+    (let ((foo (make-pathname* :directory '(:absolute "FOO") :defaults pathname)))
+      (last-char (namestring foo))))
+
+  #-scl
+  (defun directorize-pathname-host-device (pathname)
+    #+(or unix abcl)
+    (when (and #+abcl (os-unix-p) (physical-pathname-p pathname))
+      (return-from directorize-pathname-host-device pathname))
+    (let* ((root (pathname-root pathname))
+           (wild-root (wilden root))
+           (absolute-pathname (merge-pathnames* pathname root))
+           (separator (directory-separator-for-host root))
+           (root-namestring (namestring root))
+           (root-string
+             (substitute-if #\/
+                            #'(lambda (x) (or (eql x #\:)
+                                              (eql x separator)))
+                            root-namestring)))
+      (multiple-value-bind (relative path filename)
+          (split-unix-namestring-directory-components root-string :ensure-directory t)
+        (declare (ignore relative filename))
+        (let ((new-base
+                (make-pathname* :defaults root :directory `(:absolute ,@path))))
+          (translate-pathname absolute-pathname wild-root (wilden new-base))))))
+
+  #+scl
+  (defun directorize-pathname-host-device (pathname)
+    (let ((scheme (ext:pathname-scheme pathname))
+          (host (pathname-host pathname))
+          (port (ext:pathname-port pathname))
+          (directory (pathname-directory pathname)))
+      (flet ((specificp (x) (and x (not (eq x :unspecific)))))
+        (if (or (specificp port)
+                (and (specificp host) (plusp (length host)))
+                (specificp scheme))
+            (let ((prefix ""))
+              (when (specificp port)
+                (setf prefix (format nil ":~D" port)))
+              (when (and (specificp host) (plusp (length host)))
+                (setf prefix (strcat host prefix)))
+              (setf prefix (strcat ":" prefix))
+              (when (specificp scheme)
+                (setf prefix (strcat scheme prefix)))
+              (assert (and directory (eq (first directory) :absolute)))
+              (make-pathname* :directory `(:absolute ,prefix ,@(rest directory))
+                              :defaults pathname)))
+        pathname)))
+
+  (defun* (translate-pathname*) (path absolute-source destination &optional root source)
+    (declare (ignore source))
+    (cond
+      ((functionp destination)
+       (funcall destination path absolute-source))
+      ((eq destination t)
+       path)
+      ((not (pathnamep destination))
+       (error "Invalid destination"))
+      ((not (absolute-pathname-p destination))
+       (translate-pathname path absolute-source (merge-pathnames* destination root)))
+      (root
+       (translate-pathname (directorize-pathname-host-device path) absolute-source destination))
+      (t
+       (translate-pathname path absolute-source destination))))
+
+  (defvar *output-translation-function* 'identity
+    "Hook for output translations.
+
+This function needs to be idempotent, so that actions can work
+whether their inputs were translated or not,
+which they will be if we are composing operations. e.g. if some
+create-lisp-op creates a lisp file from some higher-level input,
+you need to still be able to use compile-op on that lisp file."))
 
 ;;;; -------------------------------------------------------------------------
-;;;; ASDF Interface, in terms of generic functions.
-(defgeneric* find-system (system &optional error-p))
-(defgeneric* perform-with-restarts (operation component))
-(defgeneric* perform (operation component))
-(defgeneric* operation-done-p (operation component))
-(defgeneric* explain (operation component))
-(defgeneric* output-files (operation component))
-(defgeneric* input-files (operation component))
-(defgeneric* component-operation-time (operation component))
-(defgeneric* operation-description (operation component)
-  (:documentation "returns a phrase that describes performing this operation
-on this component, e.g. \"loading /a/b/c\".
-You can put together sentences using this phrase."))
-
-(defgeneric* system-source-file (system)
-  (:documentation "Return the source file in which system is defined."))
-
-(defgeneric* component-system (component)
-  (:documentation "Find the top-level system containing COMPONENT"))
-
-(defgeneric* component-pathname (component)
-  (:documentation "Extracts the pathname applicable for a particular component."))
-
-(defgeneric* component-relative-pathname (component)
-  (:documentation "Returns a pathname for the component argument intended to be
+;;;; Portability layer around Common Lisp filesystem access
+
+(uiop/package:define-package :uiop/filesystem
+  (:nicknames :asdf/filesystem)
+  (:recycle :uiop/filesystem :asdf/pathname :asdf)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility :uiop/os :uiop/pathname)
+  (:export
+   ;; Native namestrings
+   #:native-namestring #:parse-native-namestring
+   ;; Probing the filesystem
+   #:truename* #:safe-file-write-date #:probe-file* #:directory-exists-p #:file-exists-p
+   #:directory* #:filter-logical-directory-results #:directory-files #:subdirectories
+   #:collect-sub*directories
+   ;; Resolving symlinks somewhat
+   #:truenamize #:resolve-symlinks #:*resolve-symlinks* #:resolve-symlinks*
+   ;; merging with cwd
+   #:get-pathname-defaults #:call-with-current-directory #:with-current-directory
+   ;; Environment pathnames
+   #:inter-directory-separator #:split-native-pathnames-string
+   #:getenv-pathname #:getenv-pathnames
+   #:getenv-absolute-directory #:getenv-absolute-directories
+   #:lisp-implementation-directory #:lisp-implementation-pathname-p
+   ;; Simple filesystem operations
+   #:ensure-all-directories-exist
+   #:rename-file-overwriting-target
+   #:delete-file-if-exists #:delete-empty-directory #:delete-directory-tree))
+(in-package :uiop/filesystem)
+
+;;; Native namestrings, as seen by the operating system calls rather than Lisp
+(with-upgradability ()
+  (defun native-namestring (x)
+    "From a non-wildcard CL pathname, a return namestring suitable for passing to the operating system"
+    (when x
+      (let ((p (pathname x)))
+        #+clozure (with-pathname-defaults () (ccl:native-translated-namestring p)) ; see ccl bug 978
+        #+(or cmu scl) (ext:unix-namestring p nil)
+        #+sbcl (sb-ext:native-namestring p)
+        #-(or clozure cmu sbcl scl)
+        (if (os-unix-p) (unix-namestring p)
+            (namestring p)))))
+
+  (defun parse-native-namestring (string &rest constraints &key ensure-directory &allow-other-keys)
+    "From a native namestring suitable for use by the operating system, return
+a CL pathname satisfying all the specified constraints as per ENSURE-PATHNAME"
+    (check-type string (or string null))
+    (let* ((pathname
+             (when string
+               (with-pathname-defaults ()
+                 #+clozure (ccl:native-to-pathname string)
+                 #+sbcl (sb-ext:parse-native-namestring string)
+                 #-(or clozure sbcl)
+                 (if (os-unix-p)
+                     (parse-unix-namestring string :ensure-directory ensure-directory)
+                     (parse-namestring string)))))
+           (pathname
+             (if ensure-directory
+                 (and pathname (ensure-directory-pathname pathname))
+                 pathname)))
+      (apply 'ensure-pathname pathname constraints))))
+
+
+;;; Probing the filesystem
+(with-upgradability ()
+  (defun truename* (p)
+    ;; avoids both logical-pathname merging and physical resolution issues
+    (and p (handler-case (with-pathname-defaults () (truename p)) (file-error () nil))))
+
+  (defun safe-file-write-date (pathname)
+    ;; If FILE-WRITE-DATE returns NIL, it's possible that
+    ;; the user or some other agent has deleted an input file.
+    ;; Also, generated files will not exist at the time planning is done
+    ;; and calls compute-action-stamp which calls safe-file-write-date.
+    ;; So it is very possible that we can't get a valid file-write-date,
+    ;; and we can survive and we will continue the planning
+    ;; as if the file were very old.
+    ;; (or should we treat the case in a different, special way?)
+    (and pathname
+         (handler-case (file-write-date (translate-logical-pathname pathname))
+           (file-error () nil))))
+
+  (defun probe-file* (p &key truename)
+    "when given a pathname P (designated by a string as per PARSE-NAMESTRING),
+probes the filesystem for a file or directory with given pathname.
+If it exists, return its truename is ENSURE-PATHNAME is true,
+or the original (parsed) pathname if it is false (the default)."
+    (with-pathname-defaults () ;; avoids logical-pathname issues on some implementations
+      (etypecase p
+        (null nil)
+        (string (probe-file* (parse-namestring p) :truename truename))
+        (pathname
+         (and (not (wild-pathname-p p))
+              (handler-case
+                  (or
+                   #+allegro
+                   (probe-file p :follow-symlinks truename)
+                   #-(or allegro clisp gcl2.6)
+                   (if truename
+                       (probe-file p)
+                       (ignore-errors
+                        (let ((pp (translate-logical-pathname p)))
+                          (and
+                           #+(or cmu scl) (unix:unix-stat (ext:unix-namestring pp))
+                           #+(and lispworks unix) (system:get-file-stat pp)
+                           #+sbcl (sb-unix:unix-stat (sb-ext:native-namestring pp))
+                           #-(or cmu (and lispworks unix) sbcl scl) (file-write-date pp)
+                           p))))
+                   #+(or clisp gcl2.6)
+                   #.(flet ((probe (probe)
+                              `(let ((foundtrue ,probe))
+                                 (cond
+                                   (truename foundtrue)
+                                   (foundtrue p)))))
+                       #+gcl2.6
+                       (probe '(or (probe-file p)
+                                (and (directory-pathname-p p)
+                                 (ignore-errors
+                                  (ensure-directory-pathname
+                                   (truename* (subpathname
+                                               (ensure-directory-pathname p) ".")))))))
+                       #+clisp
+                       (let* ((fs (find-symbol* '#:file-stat :posix nil))
+                              (pp (find-symbol* '#:probe-pathname :ext nil))
+                              (resolve (if pp
+                                           `(ignore-errors (,pp p))
+                                           '(or (truename* p)
+                                             (truename* (ignore-errors (ensure-directory-pathname p)))))))
+                         (if fs
+                             `(if truename
+                                  ,resolve
+                                  (and (ignore-errors (,fs p)) p))
+                             (probe resolve)))))
+                (file-error () nil)))))))
+
+  (defun directory-exists-p (x)
+    (let ((p (probe-file* x :truename t)))
+      (and (directory-pathname-p p) p)))
+
+  (defun file-exists-p (x)
+    (let ((p (probe-file* x :truename t)))
+      (and (file-pathname-p p) p)))
+
+  (defun directory* (pathname-spec &rest keys &key &allow-other-keys)
+    (apply 'directory pathname-spec
+           (append keys '#.(or #+allegro '(:directories-are-files nil :follow-symbolic-links nil)
+                               #+(or clozure digitool) '(:follow-links nil)
+                               #+clisp '(:circle t :if-does-not-exist :ignore)
+                               #+(or cmu scl) '(:follow-links nil :truenamep nil)
+                               #+sbcl (when (find-symbol* :resolve-symlinks '#:sb-impl nil)
+                                        '(:resolve-symlinks nil))))))
+
+  (defun filter-logical-directory-results (directory entries merger)
+    (if (logical-pathname-p directory)
+        ;; Try hard to not resolve logical-pathname into physical pathnames;
+        ;; otherwise logical-pathname users/lovers will be disappointed.
+        ;; If directory* could use some implementation-dependent magic,
+        ;; we will have logical pathnames already; otherwise,
+        ;; we only keep pathnames for which specifying the name and
+        ;; translating the LPN commute.
+        (loop :for f :in entries
+              :for p = (or (and (logical-pathname-p f) f)
+                           (let* ((u (ignore-errors (funcall merger f))))
+                             ;; The first u avoids a cumbersome (truename u) error.
+                             ;; At this point f should already be a truename,
+                             ;; but isn't quite in CLISP, for it doesn't have :version :newest
+                             (and u (equal (truename* u) (truename* f)) u)))
+              :when p :collect p)
+        entries))
+
+  (defun directory-files (directory &optional (pattern *wild-file*))
+    (let ((dir (pathname directory)))
+      (when (logical-pathname-p dir)
+        ;; Because of the filtering we do below,
+        ;; logical pathnames have restrictions on wild patterns.
+        ;; Not that the results are very portable when you use these patterns on physical pathnames.
+        (when (wild-pathname-p dir)
+          (error "Invalid wild pattern in logical directory ~S" directory))
+        (unless (member (pathname-directory pattern) '(() (:relative)) :test 'equal)
+          (error "Invalid file pattern ~S for logical directory ~S" pattern directory))
+        (setf pattern (make-pathname-logical pattern (pathname-host dir))))
+      (let* ((pat (merge-pathnames* pattern dir))
+             (entries (append (ignore-errors (directory* pat))
+                              #+clisp
+                              (when (equal :wild (pathname-type pattern))
+                                (ignore-errors (directory* (make-pathname :type nil :defaults pat)))))))
+        (filter-logical-directory-results
+         directory entries
+         #'(lambda (f)
+             (make-pathname :defaults dir
+                            :name (make-pathname-component-logical (pathname-name f))
+                            :type (make-pathname-component-logical (pathname-type f))
+                            :version (make-pathname-component-logical (pathname-version f))))))))
+
+  (defun subdirectories (directory)
+    (let* ((directory (ensure-directory-pathname directory))
+           #-(or abcl cormanlisp genera xcl)
+           (wild (merge-pathnames*
+                  #-(or abcl allegro cmu lispworks sbcl scl xcl)
+                  *wild-directory*
+                  #+(or abcl allegro cmu lispworks sbcl scl xcl) "*.*"
+                  directory))
+           (dirs
+             #-(or abcl cormanlisp genera xcl)
+             (ignore-errors
+              (directory* wild . #.(or #+clozure '(:directories t :files nil)
+                                       #+mcl '(:directories t))))
+             #+(or abcl xcl) (system:list-directory directory)
+             #+cormanlisp (cl::directory-subdirs directory)
+             #+genera (fs:directory-list directory))
+           #+(or abcl allegro cmu genera lispworks sbcl scl xcl)
+           (dirs (loop :for x :in dirs
+                       :for d = #+(or abcl xcl) (extensions:probe-directory x)
+                       #+allegro (excl:probe-directory x)
+                       #+(or cmu sbcl scl) (directory-pathname-p x)
+                       #+genera (getf (cdr x) :directory)
+                       #+lispworks (lw:file-directory-p x)
+                       :when d :collect #+(or abcl allegro xcl) d
+                         #+genera (ensure-directory-pathname (first x))
+                       #+(or cmu lispworks sbcl scl) x)))
+      (filter-logical-directory-results
+       directory dirs
+       (let ((prefix (or (normalize-pathname-directory-component (pathname-directory directory))
+                         '(:absolute)))) ; because allegro returns NIL for #p"FOO:"
+         #'(lambda (d)
+             (let ((dir (normalize-pathname-directory-component (pathname-directory d))))
+               (and (consp dir) (consp (cdr dir))
+                    (make-pathname
+                     :defaults directory :name nil :type nil :version nil
+                     :directory (append prefix (make-pathname-component-logical (last dir)))))))))))
+
+  (defun collect-sub*directories (directory collectp recursep collector)
+    (when (call-function collectp directory)
+      (call-function collector directory))
+    (dolist (subdir (subdirectories directory))
+      (when (call-function recursep subdir)
+        (collect-sub*directories subdir collectp recursep collector)))))
+
+;;; Resolving symlinks somewhat
+(with-upgradability ()
+  (defun truenamize (pathname)
+    "Resolve as much of a pathname as possible"
+    (block nil
+      (when (typep pathname '(or null logical-pathname)) (return pathname))
+      (let ((p pathname))
+        (unless (absolute-pathname-p p)
+          (setf p (or (absolute-pathname-p (ensure-absolute-pathname p 'get-pathname-defaults nil))
+                      (return p))))
+        (when (logical-pathname-p p) (return p))
+        (let ((found (probe-file* p :truename t)))
+          (when found (return found)))
+        (let* ((directory (normalize-pathname-directory-component (pathname-directory p)))
+               (up-components (reverse (rest directory)))
+               (down-components ()))
+          (assert (eq :absolute (first directory)))
+          (loop :while up-components :do
+            (if-let (parent (probe-file* (make-pathname* :directory `(:absolute ,@(reverse up-components))
+                                                         :name nil :type nil :version nil :defaults p)))
+              (return (merge-pathnames* (make-pathname* :directory `(:relative ,@down-components)
+                                                        :defaults p)
+                                        (ensure-directory-pathname parent)))
+              (push (pop up-components) down-components))
+                :finally (return p))))))
+
+  (defun resolve-symlinks (path)
+    #-allegro (truenamize path)
+    #+allegro
+    (if (physical-pathname-p path)
+        (or (ignore-errors (excl:pathname-resolve-symbolic-links path)) path)
+        path))
+
+  (defvar *resolve-symlinks* t
+    "Determine whether or not ASDF resolves symlinks when defining systems.
+Defaults to T.")
+
+  (defun resolve-symlinks* (path)
+    (if *resolve-symlinks*
+        (and path (resolve-symlinks path))
+        path)))
+
+
+;;; Check pathname constraints
+(with-upgradability ()
+  (defun ensure-pathname
+      (pathname &key
+                  on-error
+                  defaults type dot-dot
+                  want-pathname
+                  want-logical want-physical ensure-physical
+                  want-relative want-absolute ensure-absolute ensure-subpath
+                  want-non-wild want-wild wilden
+                  want-file want-directory ensure-directory
+                  want-existing ensure-directories-exist
+                  truename resolve-symlinks truenamize
+       &aux (p pathname)) ;; mutable working copy, preserve original
+    "Coerces its argument into a PATHNAME,
+optionally doing some transformations and checking specified constraints.
+
+If the argument is NIL, then NIL is returned unless the WANT-PATHNAME constraint is specified.
+
+If the argument is a STRING, it is first converted to a pathname via PARSE-UNIX-NAMESTRING
+reusing the keywords DEFAULTS TYPE DOT-DOT ENSURE-DIRECTORY WANT-RELATIVE;
+then the result is optionally merged into the DEFAULTS if ENSURE-ABSOLUTE is true,
+and the all the checks and transformations are run.
+
+Each non-nil constraint argument can be one of the symbols T, ERROR, CERROR or IGNORE.
+The boolean T is an alias for ERROR.
+ERROR means that an error will be raised if the constraint is not satisfied.
+CERROR means that an continuable error will be raised if the constraint is not satisfied.
+IGNORE means just return NIL instead of the pathname.
+
+The ON-ERROR argument, if not NIL, is a function designator (as per CALL-FUNCTION)
+that will be called with the the following arguments:
+a generic format string for ensure pathname, the pathname,
+the keyword argument corresponding to the failed check or transformation,
+a format string for the reason ENSURE-PATHNAME failed,
+and a list with arguments to that format string.
+If ON-ERROR is NIL, ERROR is used instead, which does the right thing.
+You could also pass (CERROR \"CONTINUE DESPITE FAILED CHECK\").
+
+The transformations and constraint checks are done in this order,
+which is also the order in the lambda-list:
+
+WANT-PATHNAME checks that pathname (after parsing if needed) is not null.
+Otherwise, if the pathname is NIL, ensure-pathname returns NIL.
+WANT-LOGICAL checks that pathname is a LOGICAL-PATHNAME
+WANT-PHYSICAL checks that pathname is not a LOGICAL-PATHNAME
+ENSURE-PHYSICAL ensures that pathname is physical via TRANSLATE-LOGICAL-PATHNAME
+WANT-RELATIVE checks that pathname has a relative directory component
+WANT-ABSOLUTE checks that pathname does have an absolute directory component
+ENSURE-ABSOLUTE merges with the DEFAULTS, then checks again
+that the result absolute is an absolute pathname indeed.
+ENSURE-SUBPATH checks that the pathname is a subpath of the DEFAULTS.
+WANT-FILE checks that pathname has a non-nil FILE component
+WANT-DIRECTORY checks that pathname has nil FILE and TYPE components
+ENSURE-DIRECTORY uses ENSURE-DIRECTORY-PATHNAME to interpret
+any file and type components as being actually a last directory component.
+WANT-NON-WILD checks that pathname is not a wild pathname
+WANT-WILD checks that pathname is a wild pathname
+WILDEN merges the pathname with **/*.*.* if it is not wild
+WANT-EXISTING checks that a file (or directory) exists with that pathname.
+ENSURE-DIRECTORIES-EXIST creates any parent directory with ENSURE-DIRECTORIES-EXIST.
+TRUENAME replaces the pathname by its truename, or errors if not possible.
+RESOLVE-SYMLINKS replaces the pathname by a variant with symlinks resolved by RESOLVE-SYMLINKS.
+TRUENAMIZE uses TRUENAMIZE to resolve as many symlinks as possible."
+    (block nil
+      (flet ((report-error (keyword description &rest arguments)
+               (call-function (or on-error 'error)
+                              "Invalid pathname ~S: ~*~?"
+                              pathname keyword description arguments)))
+        (macrolet ((err (constraint &rest arguments)
+                     `(report-error ',(intern* constraint :keyword) ,@arguments))
+                   (check (constraint condition &rest arguments)
+                     `(when ,constraint
+                        (unless ,condition (err ,constraint ,@arguments))))
+                   (transform (transform condition expr)
+                     `(when ,transform
+                        (,@(if condition `(when ,condition) '(progn))
+                         (setf p ,expr)))))
+          (etypecase p
+            ((or null pathname))
+            (string
+             (setf p (parse-unix-namestring
+                      p :defaults defaults :type type :dot-dot dot-dot
+                        :ensure-directory ensure-directory :want-relative want-relative))))
+          (check want-pathname (pathnamep p) "Expected a pathname, not NIL")
+          (unless (pathnamep p) (return nil))
+          (check want-logical (logical-pathname-p p) "Expected a logical pathname")
+          (check want-physical (physical-pathname-p p) "Expected a physical pathname")
+          (transform ensure-physical () (translate-logical-pathname p))
+          (check ensure-physical (physical-pathname-p p) "Could not translate to a physical pathname")
+          (check want-relative (relative-pathname-p p) "Expected a relative pathname")
+          (check want-absolute (absolute-pathname-p p) "Expected an absolute pathname")
+          (transform ensure-absolute (not (absolute-pathname-p p))
+                     (ensure-absolute-pathname p defaults (list #'report-error :ensure-absolute "~@?")))
+          (check ensure-absolute (absolute-pathname-p p)
+                 "Could not make into an absolute pathname even after merging with ~S" defaults)
+          (check ensure-subpath (absolute-pathname-p defaults)
+                 "cannot be checked to be a subpath of non-absolute pathname ~S" defaults)
+          (check ensure-subpath (subpathp p defaults) "is not a sub pathname of ~S" defaults)
+          (check want-file (file-pathname-p p) "Expected a file pathname")
+          (check want-directory (directory-pathname-p p) "Expected a directory pathname")
+          (transform ensure-directory (not (directory-pathname-p p)) (ensure-directory-pathname p))
+          (check want-non-wild (not (wild-pathname-p p)) "Expected a non-wildcard pathname")
+          (check want-wild (wild-pathname-p p) "Expected a wildcard pathname")
+          (transform wilden (not (wild-pathname-p p)) (wilden p))
+          (when want-existing
+            (let ((existing (probe-file* p :truename truename)))
+              (if existing
+                  (when truename
+                    (return existing))
+                  (err want-existing "Expected an existing pathname"))))
+          (when ensure-directories-exist (ensure-directories-exist p))
+          (when truename
+            (let ((truename (truename* p)))
+              (if truename
+                  (return truename)
+                  (err truename "Can't get a truename for pathname"))))
+          (transform resolve-symlinks () (resolve-symlinks p))
+          (transform truenamize () (truenamize p))
+          p)))))
+
+
+;;; Pathname defaults
+(with-upgradability ()
+  (defun get-pathname-defaults (&optional (defaults *default-pathname-defaults*))
+    (or (absolute-pathname-p defaults)
+        (merge-pathnames* defaults (getcwd))))
+
+  (defun call-with-current-directory (dir thunk)
+    (if dir
+        (let* ((dir (resolve-symlinks* (get-pathname-defaults (pathname-directory-pathname dir))))
+               (*default-pathname-defaults* dir)
+               (cwd (getcwd)))
+          (chdir dir)
+          (unwind-protect
+               (funcall thunk)
+            (chdir cwd)))
+        (funcall thunk)))
+
+  (defmacro with-current-directory ((&optional dir) &body body)
+    "Call BODY while the POSIX current working directory is set to DIR"
+    `(call-with-current-directory ,dir #'(lambda () ,@body))))
+
+
+;;; Environment pathnames
+(with-upgradability ()
+  (defun inter-directory-separator ()
+    (if (os-unix-p) #\: #\;))
+
+  (defun split-native-pathnames-string (string &rest constraints &key &allow-other-keys)
+    (loop :for namestring :in (split-string string :separator (string (inter-directory-separator)))
+          :collect (apply 'parse-native-namestring namestring constraints)))
+
+  (defun getenv-pathname (x &rest constraints &key ensure-directory want-directory on-error &allow-other-keys)
+    ;; For backward compatibility with ASDF 2, want-directory implies ensure-directory
+    (apply 'parse-native-namestring (getenvp x)
+           :ensure-directory (or ensure-directory want-directory)
+           :on-error (or on-error
+                         `(error "In (~S ~S), invalid pathname ~*~S: ~*~?" getenv-pathname ,x))
+           constraints))
+  (defun getenv-pathnames (x &rest constraints &key on-error &allow-other-keys)
+    (apply 'split-native-pathnames-string (getenvp x)
+           :on-error (or on-error
+                         `(error "In (~S ~S), invalid pathname ~*~S: ~*~?" getenv-pathnames ,x))
+           constraints))
+  (defun getenv-absolute-directory (x)
+    (getenv-pathname x :want-absolute t :ensure-directory t))
+  (defun getenv-absolute-directories (x)
+    (getenv-pathnames x :want-absolute t :ensure-directory t))
+
+  (defun lisp-implementation-directory (&key truename)
+    (declare (ignorable truename))
+    #+(or clozure ecl gcl mkcl sbcl)
+    (let ((dir
+            (ignore-errors
+             #+clozure #p"ccl:"
+             #+(or ecl mkcl) #p"SYS:"
+             #+gcl system::*system-directory*
+             #+sbcl (if-let (it (find-symbol* :sbcl-homedir-pathname :sb-int nil))
+                      (funcall it)
+                      (getenv-pathname "SBCL_HOME" :ensure-directory t)))))
+      (if (and dir truename)
+          (truename* dir)
+          dir)))
+
+  (defun lisp-implementation-pathname-p (pathname)
+    ;; Other builtin systems are those under the implementation directory
+    (and (when pathname
+           (if-let (impdir (lisp-implementation-directory))
+             (or (subpathp pathname impdir)
+                 (when *resolve-symlinks*
+                   (if-let (truename (truename* pathname))
+                     (if-let (trueimpdir (truename* impdir))
+                       (subpathp truename trueimpdir)))))))
+         t)))
+
+
+;;; Simple filesystem operations
+(with-upgradability ()
+  (defun ensure-all-directories-exist (pathnames)
+    (dolist (pathname pathnames)
+      (when pathname
+        (ensure-directories-exist (translate-logical-pathname pathname)))))
+
+  (defun rename-file-overwriting-target (source target)
+    #+clisp ;; But for a bug in CLISP 2.48, we should use :if-exists :overwrite and be atomic
+    (posix:copy-file source target :method :rename)
+    #-clisp
+    (rename-file source target
+                 #+clozure :if-exists #+clozure :rename-and-delete))
+
+  (defun delete-file-if-exists (x)
+    (when x (handler-case (delete-file x) (file-error () nil))))
+
+  (defun delete-empty-directory (directory-pathname)
+    "Delete an empty directory"
+    #+(or abcl digitool gcl) (delete-file directory-pathname)
+    #+allegro (excl:delete-directory directory-pathname)
+    #+clisp (ext:delete-directory directory-pathname)
+    #+clozure (ccl::delete-empty-directory directory-pathname)
+    #+(or cmu scl) (multiple-value-bind (ok errno)
+                       (unix:unix-rmdir (native-namestring directory-pathname))
+                     (unless ok
+                       #+cmu (error "Error number ~A when trying to delete directory ~A"
+                                    errno directory-pathname)
+                       #+scl (error "~@<Error deleting ~S: ~A~@:>"
+                                    directory-pathname (unix:get-unix-error-msg errno))))
+    #+cormanlisp (win32:delete-directory directory-pathname)
+    #+ecl (si:rmdir directory-pathname)
+    #+lispworks (lw:delete-directory directory-pathname)
+    #+mkcl (mkcl:rmdir directory-pathname)
+    #+sbcl #.(if-let (dd (find-symbol* :delete-directory :sb-ext nil))
+               `(,dd directory-pathname) ;; requires SBCL 1.0.44 or later
+               `(progn (require :sb-posix) (symbol-call :sb-posix :rmdir directory-pathname)))
+    #-(or abcl allegro clisp clozure cmu cormanlisp digitool ecl gcl lispworks sbcl scl)
+    (error "~S not implemented on ~S" 'delete-empty-directory (implementation-type))) ; genera xcl
+
+  (defun delete-directory-tree (directory-pathname &key (validate nil validatep) (if-does-not-exist :error))
+    "Delete a directory including all its recursive contents, aka rm -rf.
+
+To reduce the risk of infortunate mistakes, DIRECTORY-PATHNAME must be
+a physical non-wildcard directory pathname (not namestring).
+
+If the directory does not exist, the IF-DOES-NOT-EXIST argument specifies what happens:
+if it is :ERROR (the default), an error is signaled, whereas if it is :IGNORE, nothing is done.
+
+Furthermore, before any deletion is attempted, the DIRECTORY-PATHNAME must pass
+the validation function designated (as per ENSURE-FUNCTION) by the VALIDATE keyword argument
+which in practice is thus compulsory, and validates by returning a non-NIL result.
+If you're suicidal or extremely confident, just use :VALIDATE T."
+    (check-type if-does-not-exist (member :error :ignore))
+    (cond
+      ((not (and (pathnamep directory-pathname) (directory-pathname-p directory-pathname)
+                 (physical-pathname-p directory-pathname) (not (wild-pathname-p directory-pathname))))
+       (error "~S was asked to delete ~S but it is not a physical non-wildcard directory pathname"
+              'delete-filesystem-tree directory-pathname))
+      ((not validatep)
+       (error "~S was asked to delete ~S but was not provided a validation predicate"
+              'delete-filesystem-tree directory-pathname))
+      ((not (call-function validate directory-pathname))
+       (error "~S was asked to delete ~S but it is not valid ~@[according to ~S~]"
+              'delete-filesystem-tree directory-pathname validate))
+      ((not (directory-exists-p directory-pathname))
+       (ecase if-does-not-exist
+         (:error
+          (error "~S was asked to delete ~S but the directory does not exist"
+              'delete-filesystem-tree directory-pathname))
+         (:ignore nil)))
+      #-(or allegro cmu clozure sbcl scl)
+      ((os-unix-p) ;; On Unix, don't recursively walk the directory and delete everything in Lisp,
+       ;; except on implementations where we can prevent DIRECTORY from following symlinks;
+       ;; instead spawn a standard external program to do the dirty work.
+       (symbol-call :uiop :run-program `("rm" "-rf" ,(native-namestring directory-pathname))))
+      (t
+       ;; On supported implementation, call supported system functions
+       #+allegro (symbol-call :excl.osi :delete-directory-and-files
+                              directory-pathname :if-does-not-exist if-does-not-exist)
+       #+clozure (ccl:delete-directory directory-pathname)
+       #+genera (error "~S not implemented on ~S" 'delete-directory-tree (implementation-type))
+       #+sbcl #.(if-let (dd (find-symbol* :delete-directory :sb-ext nil))
+                  `(,dd directory-pathname :recursive t) ;; requires SBCL 1.0.44 or later
+                  '(error "~S requires SBCL 1.0.44 or later" 'delete-directory-tree))
+       ;; Outside Unix or on CMUCL and SCL that can avoid following symlinks,
+       ;; do things the hard way.
+       #-(or allegro clozure genera sbcl)
+       (let ((sub*directories
+               (while-collecting (c)
+                 (collect-sub*directories directory-pathname t t #'c))))
+             (dolist (d (nreverse sub*directories))
+               (map () 'delete-file (directory-files d))
+               (delete-empty-directory d)))))))
+
+;;;; ---------------------------------------------------------------------------
+;;;; Utilities related to streams
+
+(uiop/package:define-package :uiop/stream
+  (:nicknames :asdf/stream)
+  (:recycle :uiop/stream :asdf/stream :asdf)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility :uiop/os :uiop/pathname :uiop/filesystem)
+  (:export
+   #:*default-stream-element-type* #:*stderr* #:setup-stderr
+   #:detect-encoding #:*encoding-detection-hook* #:always-default-encoding
+   #:encoding-external-format #:*encoding-external-format-hook* #:default-encoding-external-format
+   #:*default-encoding* #:*utf-8-external-format*
+   #:with-safe-io-syntax #:call-with-safe-io-syntax #:safe-read-from-string
+   #:with-output #:output-string #:with-input
+   #:with-input-file #:call-with-input-file
+   #:finish-outputs #:format! #:safe-format!
+   #:copy-stream-to-stream #:concatenate-files #:copy-file
+   #:slurp-stream-string #:slurp-stream-lines #:slurp-stream-line
+   #:slurp-stream-forms #:slurp-stream-form
+   #:read-file-string #:read-file-lines #:read-file-forms #:read-file-form #:safe-read-file-form
+   #:eval-input #:eval-thunk #:standard-eval-thunk
+   ;; Temporary files
+   #:*temporary-directory* #:temporary-directory #:default-temporary-directory
+   #:setup-temporary-directory
+   #:call-with-temporary-file #:with-temporary-file
+   #:add-pathname-suffix #:tmpize-pathname
+   #:call-with-staging-pathname #:with-staging-pathname))
+(in-package :uiop/stream)
+
+(with-upgradability ()
+  (defvar *default-stream-element-type* (or #+(or abcl cmu cormanlisp scl xcl) 'character :default)
+    "default element-type for open (depends on the current CL implementation)")
+
+  (defvar *stderr* *error-output*
+    "the original error output stream at startup")
+
+  (defun setup-stderr ()
+    (setf *stderr*
+          #+allegro excl::*stderr*
+          #+clozure ccl::*stderr*
+          #-(or allegro clozure) *error-output*))
+  (setup-stderr))
+
+
+;;; Encodings (mostly hooks only; full support requires asdf-encodings)
+(with-upgradability ()
+  (defparameter *default-encoding*
+    ;; preserve explicit user changes to something other than the legacy default :default
+    (or (if-let (previous (and (boundp '*default-encoding*) (symbol-value '*default-encoding*)))
+          (unless (eq previous :default) previous))
+        :utf-8)
+    "Default encoding for source files.
+The default value :utf-8 is the portable thing.
+The legacy behavior was :default.
+If you (asdf:load-system :asdf-encodings) then
+you will have autodetection via *encoding-detection-hook* below,
+reading emacs-style -*- coding: utf-8 -*- specifications,
+and falling back to utf-8 or latin1 if nothing is specified.")
+
+  (defparameter *utf-8-external-format*
+    #+(and asdf-unicode (not clisp)) :utf-8
+    #+(and asdf-unicode clisp) charset:utf-8
+    #-asdf-unicode :default
+    "Default :external-format argument to pass to CL:OPEN and also
+CL:LOAD or CL:COMPILE-FILE to best process a UTF-8 encoded file.
+On modern implementations, this will decode UTF-8 code points as CL characters.
+On legacy implementations, it may fall back on some 8-bit encoding,
+with non-ASCII code points being read as several CL characters;
+hopefully, if done consistently, that won't affect program behavior too much.")
+
+  (defun always-default-encoding (pathname)
+    (declare (ignore pathname))
+    *default-encoding*)
+
+  (defvar *encoding-detection-hook* #'always-default-encoding
+    "Hook for an extension to define a function to automatically detect a file's encoding")
+
+  (defun detect-encoding (pathname)
+    (if (and pathname (not (directory-pathname-p pathname)) (probe-file* pathname))
+        (funcall *encoding-detection-hook* pathname)
+        *default-encoding*))
+
+  (defun default-encoding-external-format (encoding)
+    (case encoding
+      (:default :default) ;; for backward-compatibility only. Explicit usage discouraged.
+      (:utf-8 *utf-8-external-format*)
+      (otherwise
+       (cerror "Continue using :external-format :default" (compatfmt "~@<Your ASDF component is using encoding ~S but it isn't recognized. Your system should :defsystem-depends-on (:asdf-encodings).~:>") encoding)
+       :default)))
+
+  (defvar *encoding-external-format-hook*
+    #'default-encoding-external-format
+    "Hook for an extension to define a mapping between non-default encodings
+and implementation-defined external-format's")
+
+  (defun encoding-external-format (encoding)
+    (funcall *encoding-external-format-hook* encoding)))
+
+
+;;; Safe syntax
+(with-upgradability ()
+  (defvar *standard-readtable* (copy-readtable nil))
+
+  (defmacro with-safe-io-syntax ((&key (package :cl)) &body body)
+    "Establish safe CL reader options around the evaluation of BODY"
+    `(call-with-safe-io-syntax #'(lambda () (let ((*package* (find-package ,package))) ,@body))))
+
+  (defun call-with-safe-io-syntax (thunk &key (package :cl))
+    (with-standard-io-syntax
+      (let ((*package* (find-package package))
+            (*read-default-float-format* 'double-float)
+            (*print-readably* nil)
+            (*read-eval* nil))
+        (funcall thunk))))
+
+  (defun safe-read-from-string (string &key (package :cl) (eof-error-p t) eof-value (start 0) end preserve-whitespace)
+    (with-safe-io-syntax (:package package)
+      (read-from-string string eof-error-p eof-value :start start :end end :preserve-whitespace preserve-whitespace))))
+
+
+;;; Output to a stream or string, FORMAT-style
+(with-upgradability ()
+  (defun call-with-output (output function)
+    "Calls FUNCTION with an actual stream argument,
+behaving like FORMAT with respect to how stream designators are interpreted:
+If OUTPUT is a stream, use it as the stream.
+If OUTPUT is NIL, use a STRING-OUTPUT-STREAM as the stream, and return the resulting string.
+If OUTPUT is T, use *STANDARD-OUTPUT* as the stream.
+If OUTPUT is a string with a fill-pointer, use it as a string-output-stream.
+Otherwise, signal an error."
+    (etypecase output
+      (null
+       (with-output-to-string (stream) (funcall function stream)))
+      ((eql t)
+       (funcall function *standard-output*))
+      (stream
+       (funcall function output))
+      (string
+       (assert (fill-pointer output))
+       (with-output-to-string (stream output) (funcall function stream)))))
+
+  (defmacro with-output ((output-var &optional (value output-var)) &body body)
+    "Bind OUTPUT-VAR to an output stream, coercing VALUE (default: previous binding of OUTPUT-VAR)
+as per FORMAT, and evaluate BODY within the scope of this binding."
+    `(call-with-output ,value #'(lambda (,output-var) ,@body)))
+
+  (defun output-string (string &optional output)
+    "If the desired OUTPUT is not NIL, print the string to the output; otherwise return the string"
+    (if output
+        (with-output (output) (princ string output))
+        string)))
+
+
+;;; Input helpers
+(with-upgradability ()
+  (defun call-with-input (input function)
+    "Calls FUNCTION with an actual stream argument, interpreting
+stream designators like READ, but also coercing strings to STRING-INPUT-STREAM.
+If INPUT is a STREAM, use it as the stream.
+If INPUT is NIL, use a *STANDARD-INPUT* as the stream.
+If INPUT is T, use *TERMINAL-IO* as the stream.
+As an extension, if INPUT is a string, use it as a string-input-stream.
+Otherwise, signal an error."
+    (etypecase input
+      (null (funcall function *standard-input*))
+      ((eql t) (funcall function *terminal-io*))
+      (stream (funcall function input))
+      (string (with-input-from-string (stream input) (funcall function stream)))))
+
+  (defmacro with-input ((input-var &optional (value input-var)) &body body)
+    "Bind INPUT-VAR to an input stream, coercing VALUE (default: previous binding of INPUT-VAR)
+as per CALL-WITH-INPUT, and evaluate BODY within the scope of this binding."
+    `(call-with-input ,value #'(lambda (,input-var) ,@body)))
+
+  (defun call-with-input-file (pathname thunk
+                               &key
+                                 (element-type *default-stream-element-type*)
+                                 (external-format *utf-8-external-format*)
+                                 (if-does-not-exist :error))
+    "Open FILE for input with given recognizes options, call THUNK with the resulting stream.
+Other keys are accepted but discarded."
+    #+gcl2.6 (declare (ignore external-format))
+    (with-open-file (s pathname :direction :input
+                                :element-type element-type
+                                #-gcl2.6 :external-format #-gcl2.6 external-format
+                                :if-does-not-exist if-does-not-exist)
+      (funcall thunk s)))
+
+  (defmacro with-input-file ((var pathname &rest keys &key element-type external-format) &body body)
+    (declare (ignore element-type external-format))
+    `(call-with-input-file ,pathname #'(lambda (,var) ,@body) ,@keys)))
+
+
+;;; Ensure output buffers are flushed
+(with-upgradability ()
+  (defun finish-outputs (&rest streams)
+    "Finish output on the main output streams as well as any specified one.
+Useful for portably flushing I/O before user input or program exit."
+    ;; CCL notably buffers its stream output by default.
+    (dolist (s (append streams
+                       (list *stderr* *error-output* *standard-output* *trace-output*
+                             *debug-io* *terminal-io* *debug-io* *query-io*)))
+      (ignore-errors (finish-output s)))
+    (values))
+
+  (defun format! (stream format &rest args)
+    "Just like format, but call finish-outputs before and after the output."
+    (finish-outputs stream)
+    (apply 'format stream format args)
+    (finish-output stream))
+
+  (defun safe-format! (stream format &rest args)
+    (with-safe-io-syntax ()
+      (ignore-errors (apply 'format! stream format args))
+      (finish-outputs stream)))) ; just in case format failed
+
+
+;;; Simple Whole-Stream processing
+(with-upgradability ()
+  (defun copy-stream-to-stream (input output &key element-type buffer-size linewise prefix)
+    "Copy the contents of the INPUT stream into the OUTPUT stream.
+If LINEWISE is true, then read and copy the stream line by line, with an optional PREFIX.
+Otherwise, using WRITE-SEQUENCE using a buffer of size BUFFER-SIZE."
+    (with-open-stream (input input)
+      (if linewise
+          (loop* :for (line eof) = (multiple-value-list (read-line input nil nil))
+                 :while line :do
+                 (when prefix (princ prefix output))
+                 (princ line output)
+                 (unless eof (terpri output))
+                 (finish-output output)
+                 (when eof (return)))
+          (loop
+            :with buffer-size = (or buffer-size 8192)
+            :for buffer = (make-array (list buffer-size) :element-type (or element-type 'character))
+            :for end = (read-sequence buffer input)
+            :until (zerop end)
+            :do (write-sequence buffer output :end end)
+                (when (< end buffer-size) (return))))))
+
+  (defun concatenate-files (inputs output)
+    (with-open-file (o output :element-type '(unsigned-byte 8)
+                              :direction :output :if-exists :rename-and-delete)
+      (dolist (input inputs)
+        (with-open-file (i input :element-type '(unsigned-byte 8)
+                                 :direction :input :if-does-not-exist :error)
+          (copy-stream-to-stream i o :element-type '(unsigned-byte 8))))))
+
+  (defun copy-file (input output)
+    ;; Not available on LW personal edition or LW 6.0 on Mac: (lispworks:copy-file i f)
+    (concatenate-files (list input) output))
+
+  (defun slurp-stream-string (input &key (element-type 'character))
+    "Read the contents of the INPUT stream as a string"
+    (with-open-stream (input input)
+      (with-output-to-string (output)
+        (copy-stream-to-stream input output :element-type element-type))))
+
+  (defun slurp-stream-lines (input &key count)
+    "Read the contents of the INPUT stream as a list of lines, return those lines.
+
+Read no more than COUNT lines."
+    (check-type count (or null integer))
+    (with-open-stream (input input)
+      (loop :for n :from 0
+            :for l = (and (or (not count) (< n count))
+                          (read-line input nil nil))
+            :while l :collect l)))
+
+  (defun slurp-stream-line (input &key (at 0))
+    "Read the contents of the INPUT stream as a list of lines,
+then return the ACCESS-AT of that list of lines using the AT specifier.
+PATH defaults to 0, i.e. return the first line.
+PATH is typically an integer, or a list of an integer and a function.
+If PATH is NIL, it will return all the lines in the file.
+
+The stream will not be read beyond the Nth lines,
+where N is the index specified by path
+if path is either an integer or a list that starts with an integer."
+    (access-at (slurp-stream-lines input :count (access-at-count at)) at))
+
+  (defun slurp-stream-forms (input &key count)
+    "Read the contents of the INPUT stream as a list of forms,
+and return those forms.
+
+If COUNT is null, read to the end of the stream;
+if COUNT is an integer, stop after COUNT forms were read.
+
+BEWARE: be sure to use WITH-SAFE-IO-SYNTAX, or some variant thereof"
+    (check-type count (or null integer))
+    (loop :with eof = '#:eof
+          :for n :from 0
+          :for form = (if (and count (>= n count))
+                          eof
+                          (read-preserving-whitespace input nil eof))
+          :until (eq form eof) :collect form))
+
+  (defun slurp-stream-form (input &key (at 0))
+    "Read the contents of the INPUT stream as a list of forms,
+then return the ACCESS-AT of these forms following the AT.
+AT defaults to 0, i.e. return the first form.
+AT is typically a list of integers.
+If AT is NIL, it will return all the forms in the file.
+
+The stream will not be read beyond the Nth form,
+where N is the index specified by path,
+if path is either an integer or a list that starts with an integer.
+
+BEWARE: be sure to use WITH-SAFE-IO-SYNTAX, or some variant thereof"
+    (access-at (slurp-stream-forms input :count (access-at-count at)) at))
+
+  (defun read-file-string (file &rest keys)
+    "Open FILE with option KEYS, read its contents as a string"
+    (apply 'call-with-input-file file 'slurp-stream-string keys))
+
+  (defun read-file-lines (file &rest keys)
+    "Open FILE with option KEYS, read its contents as a list of lines
+BEWARE: be sure to use WITH-SAFE-IO-SYNTAX, or some variant thereof"
+    (apply 'call-with-input-file file 'slurp-stream-lines keys))
+
+  (defun read-file-forms (file &rest keys &key count &allow-other-keys)
+    "Open input FILE with option KEYS (except COUNT),
+and read its contents as per SLURP-STREAM-FORMS with given COUNT.
+BEWARE: be sure to use WITH-SAFE-IO-SYNTAX, or some variant thereof"
+    (apply 'call-with-input-file file
+           #'(lambda (input) (slurp-stream-forms input :count count))
+           (remove-plist-key :count keys)))
+
+  (defun read-file-form (file &rest keys &key (at 0) &allow-other-keys)
+    "Open input FILE with option KEYS (except AT),
+and read its contents as per SLURP-STREAM-FORM with given AT specifier.
+BEWARE: be sure to use WITH-SAFE-IO-SYNTAX, or some variant thereof"
+    (apply 'call-with-input-file file
+           #'(lambda (input) (slurp-stream-form input :at at))
+           (remove-plist-key :at keys)))
+
+  (defun safe-read-file-form (pathname &rest keys &key (package :cl) &allow-other-keys)
+    "Reads the specified form from the top of a file using a safe standardized syntax.
+Extracts the form using READ-FILE-FORM,
+within an WITH-SAFE-IO-SYNTAX using the specified PACKAGE."
+    (with-safe-io-syntax (:package package)
+      (apply 'read-file-form pathname (remove-plist-key :package keys))))
+
+  (defun eval-input (input)
+    "Portably read and evaluate forms from INPUT, return the last values."
+    (with-input (input)
+      (loop :with results :with eof ='#:eof
+            :for form = (read input nil eof)
+            :until (eq form eof)
+            :do (setf results (multiple-value-list (eval form)))
+            :finally (return (apply 'values results)))))
+
+  (defun eval-thunk (thunk)
+    "Evaluate a THUNK of code:
+If a function, FUNCALL it without arguments.
+If a constant literal and not a sequence, return it.
+If a cons or a symbol, EVAL it.
+If a string, repeatedly read and evaluate from it, returning the last values."
+    (etypecase thunk
+      ((or boolean keyword number character pathname) thunk)
+      ((or cons symbol) (eval thunk))
+      (function (funcall thunk))
+      (string (eval-input thunk))))
+
+  (defun standard-eval-thunk (thunk &key (package :cl))
+    "Like EVAL-THUNK, but in a more standardized evaluation context."
+    ;; Note: it's "standard-" not "safe-", because evaluation is never safe.
+    (when thunk
+      (with-safe-io-syntax (:package package)
+        (let ((*read-eval* t))
+          (eval-thunk thunk))))))
+
+
+;;; Using temporary files
+(with-upgradability ()
+  (defun default-temporary-directory ()
+    (or
+     (when (os-unix-p)
+       (or (getenv-pathname "TMPDIR" :ensure-directory t)
+           (parse-native-namestring "/tmp/")))
+     (when (os-windows-p)
+       (getenv-pathname "TEMP" :ensure-directory t))
+     (subpathname (user-homedir-pathname) "tmp/")))
+
+  (defvar *temporary-directory* nil)
+
+  (defun temporary-directory ()
+    (or *temporary-directory* (default-temporary-directory)))
+
+  (defun setup-temporary-directory ()
+    (setf *temporary-directory* (default-temporary-directory))
+    ;; basic lack fixed after gcl 2.7.0-61, but ending / required still on 2.7.0-64.1
+    #+(and gcl (not gcl2.6)) (setf system::*tmp-dir* *temporary-directory*))
+
+  (defun call-with-temporary-file
+      (thunk &key
+               prefix keep (direction :io)
+               (element-type *default-stream-element-type*)
+               (external-format :default))
+    #+gcl2.6 (declare (ignorable external-format))
+    (check-type direction (member :output :io))
+    (loop
+      :with prefix = (namestring (ensure-absolute-pathname (or prefix "tmp") #'temporary-directory))
+      :for counter :from (random (ash 1 32))
+      :for pathname = (pathname (format nil "~A~36R" prefix counter)) :do
+        ;; TODO: on Unix, do something about umask
+        ;; TODO: on Unix, audit the code so we make sure it uses O_CREAT|O_EXCL
+        ;; TODO: on Unix, use CFFI and mkstemp -- but asdf/driver is precisely meant to not depend on CFFI or on anything! Grrrr.
+        (with-open-file (stream pathname
+                                :direction direction
+                                :element-type element-type
+                                #-gcl2.6 :external-format #-gcl2.6 external-format
+                                :if-exists nil :if-does-not-exist :create)
+          (when stream
+            (return
+              (if keep
+                  (funcall thunk stream pathname)
+                  (unwind-protect
+                       (funcall thunk stream pathname)
+                    (ignore-errors (delete-file pathname)))))))))
+
+  (defmacro with-temporary-file ((&key (stream (gensym "STREAM") streamp)
+                                    (pathname (gensym "PATHNAME") pathnamep)
+                                    prefix keep direction element-type external-format)
+                                 &body body)
+    "Evaluate BODY where the symbols specified by keyword arguments
+STREAM and PATHNAME are bound corresponding to a newly created temporary file
+ready for I/O. Unless KEEP is specified, delete the file afterwards."
+    (check-type stream symbol)
+    (check-type pathname symbol)
+    `(flet ((think (,stream ,pathname)
+              ,@(unless pathnamep `((declare (ignore ,pathname))))
+              ,@(unless streamp `((when ,stream (close ,stream))))
+              ,@body))
+       #-gcl (declare (dynamic-extent #'think))
+       (call-with-temporary-file
+        #'think
+        ,@(when direction `(:direction ,direction))
+        ,@(when prefix `(:prefix ,prefix))
+        ,@(when keep `(:keep ,keep))
+        ,@(when element-type `(:element-type ,element-type))
+        ,@(when external-format `(:external-format external-format)))))
+
+  ;; Temporary pathnames in simple cases where no contention is assumed
+  (defun add-pathname-suffix (pathname suffix)
+    (make-pathname :name (strcat (pathname-name pathname) suffix)
+                   :defaults pathname))
+
+  (defun tmpize-pathname (x)
+    (add-pathname-suffix x "-ASDF-TMP"))
+
+  (defun call-with-staging-pathname (pathname fun)
+    "Calls fun with a staging pathname, and atomically
+renames the staging pathname to the pathname in the end.
+Note: this protects only against failure of the program,
+not against concurrent attempts.
+For the latter case, we ought pick random suffix and atomically open it."
+    (let* ((pathname (pathname pathname))
+           (staging (tmpize-pathname pathname)))
+      (unwind-protect
+           (multiple-value-prog1
+               (funcall fun staging)
+             (rename-file-overwriting-target staging pathname))
+        (delete-file-if-exists staging))))
+
+  (defmacro with-staging-pathname ((pathname-var &optional (pathname-value pathname-var)) &body body)
+    `(call-with-staging-pathname ,pathname-value #'(lambda (,pathname-var) ,@body))))
+
+;;;; -------------------------------------------------------------------------
+;;;; Starting, Stopping, Dumping a Lisp image
+
+(uiop/package:define-package :uiop/image
+  (:nicknames :asdf/image)
+  (:recycle :uiop/image :asdf/image :xcvb-driver)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility :uiop/pathname :uiop/stream :uiop/os)
+  (:export
+   #:*image-dumped-p* #:raw-command-line-arguments #:*command-line-arguments*
+   #:command-line-arguments #:raw-command-line-arguments #:setup-command-line-arguments
+   #:*lisp-interaction*
+   #:*fatal-conditions* #:fatal-condition-p #:handle-fatal-condition
+   #:call-with-fatal-condition-handler #:with-fatal-condition-handler
+   #:*image-restore-hook* #:*image-prelude* #:*image-entry-point*
+   #:*image-postlude* #:*image-dump-hook*
+   #:quit #:die #:raw-print-backtrace #:print-backtrace #:print-condition-backtrace
+   #:shell-boolean-exit
+   #:register-image-restore-hook #:register-image-dump-hook
+   #:call-image-restore-hook #:call-image-dump-hook
+   #:restore-image #:dump-image #:create-image
+))
+(in-package :uiop/image)
+
+(with-upgradability ()
+  (defvar *lisp-interaction* t
+    "Is this an interactive Lisp environment, or is it batch processing?")
+
+  (defvar *command-line-arguments* nil
+    "Command-line arguments")
+
+  (defvar *image-dumped-p* nil ; may matter as to how to get to command-line-arguments
+    "Is this a dumped image? As a standalone executable?")
+
+  (defvar *image-restore-hook* nil
+    "Functions to call (in reverse order) when the image is restored")
+
+  (defvar *image-restored-p* nil
+    "Has the image been restored? A boolean, or :in-progress while restoring, :in-regress while dumping")
+
+  (defvar *image-prelude* nil
+    "a form to evaluate, or string containing forms to read and evaluate
+when the image is restarted, but before the entry point is called.")
+
+  (defvar *image-entry-point* nil
+    "a function with which to restart the dumped image when execution is restored from it.")
+
+  (defvar *image-postlude* nil
+    "a form to evaluate, or string containing forms to read and evaluate
+before the image dump hooks are called and before the image is dumped.")
+
+  (defvar *image-dump-hook* nil
+    "Functions to call (in order) when before an image is dumped")
+
+  (defvar *fatal-conditions* '(error)
+    "conditions that cause the Lisp image to enter the debugger if interactive,
+or to die if not interactive"))
+
+
+;;; Exiting properly or im-
+(with-upgradability ()
+  (defun quit (&optional (code 0) (finish-output t))
+    "Quits from the Lisp world, with the given exit status if provided.
+This is designed to abstract away the implementation specific quit forms."
+    (when finish-output ;; essential, for ClozureCL, and for standard compliance.
+      (finish-outputs))
+    #+(or abcl xcl) (ext:quit :status code)
+    #+allegro (excl:exit code :quiet t)
+    #+clisp (ext:quit code)
+    #+clozure (ccl:quit code)
+    #+cormanlisp (win32:exitprocess code)
+    #+(or cmu scl) (unix:unix-exit code)
+    #+ecl (si:quit code)
+    #+gcl (lisp:quit code)
+    #+genera (error "You probably don't want to Halt the Machine. (code: ~S)" code)
+    #+lispworks (lispworks:quit :status code :confirm nil :return nil :ignore-errors-p t)
+    #+mcl (ccl:quit) ;; or should we use FFI to call libc's exit(3) ?
+    #+mkcl (mk-ext:quit :exit-code code)
+    #+sbcl #.(let ((exit (find-symbol* :exit :sb-ext nil))
+                   (quit (find-symbol* :quit :sb-ext nil)))
+               (cond
+                 (exit `(,exit :code code :abort (not finish-output)))
+                 (quit `(,quit :unix-status code :recklessly-p (not finish-output)))))
+    #-(or abcl allegro clisp clozure cmu ecl gcl genera lispworks mcl mkcl sbcl scl xcl)
+    (error "~S called with exit code ~S but there's no quitting on this implementation" 'quit code))
+
+  (defun die (code format &rest arguments)
+    "Die in error with some error message"
+    (with-safe-io-syntax ()
+      (ignore-errors
+       (fresh-line *stderr*)
+       (apply #'format *stderr* format arguments)
+       (format! *stderr* "~&")))
+    (quit code))
+
+  (defun raw-print-backtrace (&key (stream *debug-io*) count)
+    "Print a backtrace, directly accessing the implementation"
+    (declare (ignorable stream count))
+    #+abcl
+    (let ((*debug-io* stream)) (top-level::backtrace-command count))
+    #+allegro
+    (let ((*terminal-io* stream)
+          (*standard-output* stream)
+          (tpl:*zoom-print-circle* *print-circle*)
+          (tpl:*zoom-print-level* *print-level*)
+          (tpl:*zoom-print-length* *print-length*))
+      (tpl:do-command "zoom"
+        :from-read-eval-print-loop nil
+        :count t
+        :all t))
+    #+clisp
+    (system::print-backtrace :out stream :limit count)
+    #+(or clozure mcl)
+    (let ((*debug-io* stream))
+      (ccl:print-call-history :count count :start-frame-number 1)
+      (finish-output stream))
+    #+(or cmu scl)
+    (let ((debug:*debug-print-level* *print-level*)
+          (debug:*debug-print-length* *print-length*))
+      (debug:backtrace most-positive-fixnum stream))
+    #+ecl
+    (si::tpl-backtrace)
+    #+lispworks
+    (let ((dbg::*debugger-stack*
+            (dbg::grab-stack nil :how-many (or count most-positive-fixnum)))
+          (*debug-io* stream)
+          (dbg:*debug-print-level* *print-level*)
+          (dbg:*debug-print-length* *print-length*))
+      (dbg:bug-backtrace nil))
+    #+sbcl
+    (sb-debug:backtrace
+     #.(if (find-symbol* "*VERBOSITY*" "SB-DEBUG" nil) :stream '(or count most-positive-fixnum))
+     stream))
+
+  (defun print-backtrace (&rest keys &key stream count)
+    (declare (ignore stream count))
+    (with-safe-io-syntax (:package :cl)
+      (let ((*print-readably* nil)
+            (*print-circle* t)
+            (*print-miser-width* 75)
+            (*print-length* nil)
+            (*print-level* nil)
+            (*print-pretty* t))
+        (ignore-errors (apply 'raw-print-backtrace keys)))))
+
+  (defun print-condition-backtrace (condition &key (stream *stderr*) count)
+    ;; We print the condition *after* the backtrace,
+    ;; for the sake of who sees the backtrace at a terminal.
+    ;; It is up to the caller to print the condition *before*, with some context.
+    (print-backtrace :stream stream :count count)
+    (when condition
+      (safe-format! stream "~&Above backtrace due to this condition:~%~A~&"
+                    condition)))
+
+  (defun fatal-condition-p (condition)
+    (match-any-condition-p condition *fatal-conditions*))
+
+  (defun handle-fatal-condition (condition)
+    "Depending on whether *LISP-INTERACTION* is set, enter debugger or die"
+    (cond
+      (*lisp-interaction*
+       (invoke-debugger condition))
+      (t
+       (safe-format! *stderr* "~&Fatal condition:~%~A~%" condition)
+       (print-condition-backtrace condition :stream *stderr*)
+       (die 99 "~A" condition))))
+
+  (defun call-with-fatal-condition-handler (thunk)
+    (handler-bind (((satisfies fatal-condition-p) #'handle-fatal-condition))
+      (funcall thunk)))
+
+  (defmacro with-fatal-condition-handler ((&optional) &body body)
+    `(call-with-fatal-condition-handler #'(lambda () ,@body)))
+
+  (defun shell-boolean-exit (x)
+    "Quit with a return code that is 0 iff argument X is true"
+    (quit (if x 0 1))))
+
+
+;;; Using image hooks
+(with-upgradability ()
+  (defun register-image-restore-hook (hook &optional (call-now-p t))
+    (register-hook-function '*image-restore-hook* hook call-now-p))
+
+  (defun register-image-dump-hook (hook &optional (call-now-p nil))
+    (register-hook-function '*image-dump-hook* hook call-now-p))
+
+  (defun call-image-restore-hook ()
+    (call-functions (reverse *image-restore-hook*)))
+
+  (defun call-image-dump-hook ()
+    (call-functions *image-dump-hook*)))
+
+
+;;; Proper command-line arguments
+(with-upgradability ()
+  (defun raw-command-line-arguments ()
+    "Find what the actual command line for this process was."
+    #+abcl ext:*command-line-argument-list* ; Use 1.0.0 or later!
+    #+allegro (sys:command-line-arguments) ; default: :application t
+    #+clisp (coerce (ext:argv) 'list)
+    #+clozure (ccl::command-line-arguments)
+    #+(or cmu scl) extensions:*command-line-strings*
+    #+ecl (loop :for i :from 0 :below (si:argc) :collect (si:argv i))
+    #+gcl si:*command-args*
+    #+genera nil
+    #+lispworks sys:*line-arguments-list*
+    #+sbcl sb-ext:*posix-argv*
+    #+xcl system:*argv*
+    #-(or abcl allegro clisp clozure cmu ecl gcl genera lispworks sbcl scl xcl)
+    (error "raw-command-line-arguments not implemented yet"))
+
+  (defun command-line-arguments (&optional (arguments (raw-command-line-arguments)))
+    "Extract user arguments from command-line invocation of current process.
+Assume the calling conventions of a generated script that uses --
+if we are not called from a directly executable image."
+    #+abcl arguments
+    #-abcl
+    (let* (#-(or sbcl allegro)
+           (arguments
+             (if (eq *image-dumped-p* :executable)
+                 arguments
+                 (member "--" arguments :test 'string-equal))))
+      (rest arguments)))
+
+  (defun setup-command-line-arguments ()
+    (setf *command-line-arguments* (command-line-arguments)))
+
+  (defun restore-image (&key
+                          ((:lisp-interaction *lisp-interaction*) *lisp-interaction*)
+                          ((:restore-hook *image-restore-hook*) *image-restore-hook*)
+                          ((:prelude *image-prelude*) *image-prelude*)
+                          ((:entry-point *image-entry-point*) *image-entry-point*)
+                          (if-already-restored '(cerror "RUN RESTORE-IMAGE ANYWAY")))
+    (when *image-restored-p*
+      (if if-already-restored
+          (call-function if-already-restored "Image already ~:[being ~;~]restored" (eq *image-restored-p* t))
+          (return-from restore-image)))
+    (with-fatal-condition-handler ()
+      (setf *image-restored-p* :in-progress)
+      (call-image-restore-hook)
+      (standard-eval-thunk *image-prelude*)
+      (setf *image-restored-p* t)
+      (let ((results (multiple-value-list
+                      (if *image-entry-point*
+                          (call-function *image-entry-point*)
+                          t))))
+        (if *lisp-interaction*
+            (apply 'values results)
+            (shell-boolean-exit (first results)))))))
+
+
+;;; Dumping an image
+
+(with-upgradability ()
+  (defun dump-image (filename &key output-name executable
+                                ((:postlude *image-postlude*) *image-postlude*)
+                                ((:dump-hook *image-dump-hook*) *image-dump-hook*)
+                                #+clozure prepend-symbols #+clozure (purify t))
+    (declare (ignorable filename output-name executable))
+    (setf *image-dumped-p* (if executable :executable t))
+    (setf *image-restored-p* :in-regress)
+    (standard-eval-thunk *image-postlude*)
+    (call-image-dump-hook)
+    (setf *image-restored-p* nil)
+    #-(or clisp clozure cmu lispworks sbcl scl)
+    (when executable
+      (error "Dumping an executable is not supported on this implementation! Aborting."))
+    #+allegro
+    (progn
+      (sys:resize-areas :global-gc t :pack-heap t :sift-old-areas t :tenure t) ; :new 5000000
+      (excl:dumplisp :name filename :suppress-allegro-cl-banner t))
+    #+clisp
+    (apply #'ext:saveinitmem filename
+           :quiet t
+           :start-package *package*
+           :keep-global-handlers nil
+           :executable (if executable 0 t) ;--- requires clisp 2.48 or later, still catches --clisp-x
+           (when executable
+             (list
+              ;; :parse-options nil ;--- requires a non-standard patch to clisp.
+              :norc t :script nil :init-function #'restore-image)))
+    #+clozure
+    (flet ((dump (prepend-kernel)
+             (ccl:save-application filename :prepend-kernel prepend-kernel :purify purify
+                                            :toplevel-function (when executable #'restore-image))))
+      ;;(setf ccl::*application* (make-instance 'ccl::lisp-development-system))
+      (if prepend-symbols
+          (with-temporary-file (:prefix "ccl-symbols-" :direction :output :pathname path)
+            (require 'elf)
+            (funcall (fdefinition 'ccl::write-elf-symbols-to-file) path)
+            (dump path))
+          (dump t)))
+    #+(or cmu scl)
+    (progn
+      (ext:gc :full t)
+      (setf ext:*batch-mode* nil)
+      (setf ext::*gc-run-time* 0)
+      (apply 'ext:save-lisp filename #+cmu :executable #+cmu t
+                                     (when executable '(:init-function restore-image :process-command-line nil))))
+    #+gcl
+    (progn
+      (si::set-hole-size 500) (si::gbc nil) (si::sgc-on t)
+      (si::save-system filename))
+    #+lispworks
+    (if executable
+        (lispworks:deliver 'restore-image filename 0 :interface nil)
+        (hcl:save-image filename :environment nil))
+    #+sbcl
+    (progn
+      ;;(sb-pcl::precompile-random-code-segments) ;--- it is ugly slow at compile-time (!) when the initial core is a big CLOS program. If you want it, do it yourself
+      (setf sb-ext::*gc-run-time* 0)
+      (apply 'sb-ext:save-lisp-and-die filename
+             :executable t ;--- always include the runtime that goes with the core
+             (when executable (list :toplevel #'restore-image :save-runtime-options t)))) ;--- only save runtime-options for standalone executables
+    #-(or allegro clisp clozure cmu gcl lispworks sbcl scl)
+    (error "Can't ~S ~S: UIOP doesn't support image dumping with ~A.~%"
+           'dump-image filename (nth-value 1 (implementation-type))))
+
+  (defun create-image (destination object-files
+                       &key kind output-name prologue-code epilogue-code
+                         (prelude () preludep) (postlude () postludep)
+                         (entry-point () entry-point-p) build-args)
+    (declare (ignorable destination object-files kind output-name prologue-code epilogue-code
+                        prelude preludep postlude postludep entry-point entry-point-p build-args))
+    ;; Is it meaningful to run these in the current environment?
+    ;; only if we also track the object files that constitute the "current" image,
+    ;; and otherwise simulate dump-image, including quitting at the end.
+    #-ecl (error "~S not implemented for your implementation (yet)" 'create-image)
+    #+ecl
+    (progn
+      (check-type kind (member :binary :dll :lib :static-library :program :object :fasl :program))
+      (apply 'c::builder
+             kind (pathname destination)
+             :lisp-files object-files
+             :init-name (c::compute-init-name (or output-name destination) :kind kind)
+             :prologue-code prologue-code
+             :epilogue-code
+             `(progn
+                ,epilogue-code
+                ,@(when (eq kind :program)
+                    `((setf *image-dumped-p* :executable)
+                      (restore-image ;; default behavior would be (si::top-level)
+                       ,@(when preludep `(:prelude ',prelude))
+                       ,@(when entry-point-p `(:entry-point ',entry-point))))))
+             build-args))))
+
+
+;;; Some universal image restore hooks
+(with-upgradability ()
+  (map () 'register-image-restore-hook
+       '(setup-temporary-directory setup-stderr setup-command-line-arguments
+         #+abcl detect-os)))
+;;;; -------------------------------------------------------------------------
+;;;; run-program initially from xcvb-driver.
+
+(uiop/package:define-package :uiop/run-program
+  (:nicknames :asdf/run-program)
+  (:recycle :uiop/run-program :asdf/run-program :xcvb-driver)
+  (:use :uiop/common-lisp :uiop/utility :uiop/pathname :uiop/os :uiop/filesystem :uiop/stream)
+  (:export
+   ;;; Escaping the command invocation madness
+   #:easy-sh-character-p #:escape-sh-token #:escape-sh-command
+   #:escape-windows-token #:escape-windows-command
+   #:escape-token #:escape-command
+
+   ;;; run-program
+   #:slurp-input-stream
+   #:run-program
+   #:subprocess-error
+   #:subprocess-error-code #:subprocess-error-command #:subprocess-error-process
+   ))
+(in-package :uiop/run-program)
+
+;;;; ----- Escaping strings for the shell -----
+
+(with-upgradability ()
+  (defun requires-escaping-p (token &key good-chars bad-chars)
+    "Does this token require escaping, given the specification of
+either good chars that don't need escaping or bad chars that do need escaping,
+as either a recognizing function or a sequence of characters."
+    (some
+     (cond
+       ((and good-chars bad-chars)
+        (error "only one of good-chars and bad-chars can be provided"))
+       ((functionp good-chars)
+        (complement good-chars))
+       ((functionp bad-chars)
+        bad-chars)
+       ((and good-chars (typep good-chars 'sequence))
+        #'(lambda (c) (not (find c good-chars))))
+       ((and bad-chars (typep bad-chars 'sequence))
+        #'(lambda (c) (find c bad-chars)))
+       (t (error "requires-escaping-p: no good-char criterion")))
+     token))
+
+  (defun escape-token (token &key stream quote good-chars bad-chars escaper)
+    "Call the ESCAPER function on TOKEN string if it needs escaping as per
+REQUIRES-ESCAPING-P using GOOD-CHARS and BAD-CHARS, otherwise output TOKEN,
+using STREAM as output (or returning result as a string if NIL)"
+    (if (requires-escaping-p token :good-chars good-chars :bad-chars bad-chars)
+        (with-output (stream)
+          (apply escaper token stream (when quote `(:quote ,quote))))
+        (output-string token stream)))
+
+  (defun escape-windows-token-within-double-quotes (x &optional s)
+    "Escape a string token X within double-quotes
+for use within a MS Windows command-line, outputing to S."
+    (labels ((issue (c) (princ c s))
+             (issue-backslash (n) (loop :repeat n :do (issue #\\))))
+      (loop
+        :initially (issue #\") :finally (issue #\")
+        :with l = (length x) :with i = 0
+        :for i+1 = (1+ i) :while (< i l) :do
+          (case (char x i)
+            ((#\") (issue-backslash 1) (issue #\") (setf i i+1))
+            ((#\\)
+             (let* ((j (and (< i+1 l) (position-if-not
+                                       #'(lambda (c) (eql c #\\)) x :start i+1)))
+                    (n (- (or j l) i)))
+               (cond
+                 ((null j)
+                  (issue-backslash (* 2 n)) (setf i l))
+                 ((and (< j l) (eql (char x j) #\"))
+                  (issue-backslash (1+ (* 2 n))) (issue #\") (setf i (1+ j)))
+                 (t
+                  (issue-backslash n) (setf i j)))))
+            (otherwise
+             (issue (char x i)) (setf i i+1))))))
+
+  (defun escape-windows-token (token &optional s)
+    "Escape a string TOKEN within double-quotes if needed
+for use within a MS Windows command-line, outputing to S."
+    (escape-token token :stream s :bad-chars #(#\space #\tab #\") :quote nil
+                        :escaper 'escape-windows-token-within-double-quotes))
+
+  (defun escape-sh-token-within-double-quotes (x s &key (quote t))
+    "Escape a string TOKEN within double-quotes
+for use within a POSIX Bourne shell, outputing to S;
+omit the outer double-quotes if key argument :QUOTE is NIL"
+    (when quote (princ #\" s))
+    (loop :for c :across x :do
+      (when (find c "$`\\\"") (princ #\\ s))
+      (princ c s))
+    (when quote (princ #\" s)))
+
+  (defun easy-sh-character-p (x)
+    (or (alphanumericp x) (find x "+-_.,%@:/")))
+
+  (defun escape-sh-token (token &optional s)
+    "Escape a string TOKEN within double-quotes if needed
+for use within a POSIX Bourne shell, outputing to S."
+    (escape-token token :stream s :quote #\" :good-chars
+                  #'easy-sh-character-p
+                        :escaper 'escape-sh-token-within-double-quotes))
+
+  (defun escape-shell-token (token &optional s)
+    (cond
+      ((os-unix-p) (escape-sh-token token s))
+      ((os-windows-p) (escape-windows-token token s))))
+
+  (defun escape-command (command &optional s
+                                  (escaper 'escape-shell-token))
+    "Given a COMMAND as a list of tokens, return a string of the
+spaced, escaped tokens, using ESCAPER to escape."
+    (etypecase command
+      (string (output-string command s))
+      (list (with-output (s)
+              (loop :for first = t :then nil :for token :in command :do
+                (unless first (princ #\space s))
+                (funcall escaper token s))))))
+
+  (defun escape-windows-command (command &optional s)
+    "Escape a list of command-line arguments into a string suitable for parsing
+by CommandLineToArgv in MS Windows"
+    ;; http://msdn.microsoft.com/en-us/library/bb776391(v=vs.85).aspx
+    ;; http://msdn.microsoft.com/en-us/library/17w5ykft(v=vs.85).aspx
+    (escape-command command s 'escape-windows-token))
+
+  (defun escape-sh-command (command &optional s)
+    "Escape a list of command-line arguments into a string suitable for parsing
+by /bin/sh in POSIX"
+    (escape-command command s 'escape-sh-token))
+
+  (defun escape-shell-command (command &optional stream)
+    "Escape a command for the current operating system's shell"
+    (escape-command command stream 'escape-shell-token)))
+
+
+;;;; Slurping a stream, typically the output of another program
+(with-upgradability ()
+  (defgeneric slurp-input-stream (processor input-stream &key &allow-other-keys))
+  
+  #-(or gcl2.6 genera)
+  (defmethod slurp-input-stream ((function function) input-stream &key &allow-other-keys)
+    (funcall function input-stream))
+
+  (defmethod slurp-input-stream ((list cons) input-stream &key &allow-other-keys)
+    (apply (first list) (cons input-stream (rest list))))
+
+  #-(or gcl2.6 genera)
+  (defmethod slurp-input-stream ((output-stream stream) input-stream
+                                 &key linewise prefix (element-type 'character) buffer-size &allow-other-keys)
+    (copy-stream-to-stream
+     input-stream output-stream
+     :linewise linewise :prefix prefix :element-type element-type :buffer-size buffer-size))
+
+  (defmethod slurp-input-stream ((x (eql 'string)) stream &key &allow-other-keys)
+    (declare (ignorable x))
+    (slurp-stream-string stream))
+
+  (defmethod slurp-input-stream ((x (eql :string)) stream &key &allow-other-keys)
+    (declare (ignorable x))
+    (slurp-stream-string stream))
+
+  (defmethod slurp-input-stream ((x (eql :lines)) stream &key count &allow-other-keys)
+    (declare (ignorable x))
+    (slurp-stream-lines stream :count count))
+
+  (defmethod slurp-input-stream ((x (eql :line)) stream &key (at 0) &allow-other-keys)
+    (declare (ignorable x))
+    (slurp-stream-line stream :at at))
+
+  (defmethod slurp-input-stream ((x (eql :forms)) stream &key count &allow-other-keys)
+    (declare (ignorable x))
+    (slurp-stream-forms stream :count count))
+
+  (defmethod slurp-input-stream ((x (eql :form)) stream &key (at 0) &allow-other-keys)
+    (declare (ignorable x))
+    (slurp-stream-form stream :at at))
+
+  (defmethod slurp-input-stream (x stream
+                                 &key linewise prefix (element-type 'character) buffer-size
+                                 &allow-other-keys)
+    (declare (ignorable stream linewise prefix element-type buffer-size))
+    (cond
+      #+(or gcl2.6 genera)
+      ((functionp x) (funcall x stream))
+      #+(or gcl2.6 genera)
+      ((output-stream-p x)
+       (copy-stream-to-stream
+        input-stream output-stream
+        :linewise linewise :prefix prefix :element-type element-type :buffer-size buffer-size))
+      (t
+       (error "Invalid ~S destination ~S" 'slurp-input-stream x)))))
+
+
+;;;; ----- Running an external program -----
+;;; Simple variant of run-program with no input, and capturing output
+;;; On some implementations, may output to a temporary file...
+(with-upgradability ()
+  (define-condition subprocess-error (error)
+    ((code :initform nil :initarg :code :reader subprocess-error-code)
+     (command :initform nil :initarg :command :reader subprocess-error-command)
+     (process :initform nil :initarg :process :reader subprocess-error-process))
+    (:report (lambda (condition stream)
+               (format stream "Subprocess~@[ ~S~]~@[ run with command ~S~] exited with error~@[ code ~D~]"
+                       (subprocess-error-process condition)
+                       (subprocess-error-command condition)
+                       (subprocess-error-code condition)))))
+
+  (defun run-program (command
+                       &key output ignore-error-status force-shell
+                       (element-type *default-stream-element-type*)
+                       (external-format :default)
+                       &allow-other-keys)
+    "Run program specified by COMMAND,
+either a list of strings specifying a program and list of arguments,
+or a string specifying a shell command (/bin/sh on Unix, CMD.EXE on Windows);
+have its output processed by the OUTPUT processor function
+as per SLURP-INPUT-STREAM,
+or merely output to the inherited standard output if it's NIL.
+Always call a shell (rather than directly execute the command)
+if FORCE-SHELL is specified.
+Issue an error if the process wasn't successful unless IGNORE-ERROR-STATUS
+is specified.
+Return the exit status code of the process that was called.
+Use ELEMENT-TYPE and EXTERNAL-FORMAT for the stream passed to the OUTPUT processor."
+    (declare (ignorable ignore-error-status element-type external-format))
+    #-(or abcl allegro clisp clozure cmu cormanlisp ecl gcl lispworks mcl sbcl scl xcl)
+    (error "RUN-PROGRAM not implemented for this Lisp")
+    (labels (#+(or allegro clisp clozure cmu ecl (and lispworks os-unix) sbcl scl)
+             (run-program (command &key pipe interactive)
+               "runs the specified command (a list of program and arguments).
+              If using a pipe, returns two values: process and stream
+              If not using a pipe, returns one values: the process result;
+              also, inherits the output stream."
+               ;; NB: these implementations have unix vs windows set at compile-time.
+               (assert (not (and pipe interactive)))
+               (let* ((wait (not pipe))
+                      #-(and clisp os-windows)
+                      (command
+                        (etypecase command
+                          #+os-unix (string `("/bin/sh" "-c" ,command))
+                          #+os-unix (list command)
+                          #+os-windows
+                          (string
+                           ;; NB: We do NOT add cmd /c here. You might want to.
+                           #+allegro command
+                           ;; On ClozureCL for Windows, we assume you are using
+                           ;; r15398 or later in 1.9 or later,
+                           ;; so that bug 858 is fixed http://trac.clozure.com/ccl/ticket/858
+                           #+clozure (cons "cmd" (strcat "/c " command))
+                           ;; NB: On other Windows implementations, this is utterly bogus
+                           ;; except in the most trivial cases where no quoting is needed.
+                           ;; Use at your own risk.
+                           #-(or allegro clozure) (list "cmd" "/c" command))
+                          #+os-windows
+                          (list
+                           #+(or allegro clozure) (escape-windows-command command)
+                           #-(or allegro clozure) command)))
+                      #+(and clozure os-windows) (command (list command))
+                      (process*
+                        (multiple-value-list
+                         #+allegro
+                         (excl:run-shell-command
+                          #+os-unix (coerce (cons (first command) command) 'vector)
+                          #+os-windows command
+                          :input interactive :output (or (and pipe :stream) interactive) :wait wait
+                          #+os-windows :show-window #+os-windows (and (or (null output) pipe) :hide))
+                         #+clisp
+                         (flet ((run (f &rest args)
+                                  (apply f `(,@args :input ,(when interactive :terminal) :wait ,wait :output
+                                                    ,(if pipe :stream :terminal)))))
+                           (etypecase command
+                             #+os-windows (run 'ext:run-shell-command command)
+                             (list (run 'ext:run-program (car command)
+                                        :arguments (cdr command)))))
+                         #+lispworks
+                         (system:run-shell-command
+                          (cons "/usr/bin/env" command) ; lispworks wants a full path.
+                          :input interactive :output (or (and pipe :stream) interactive)
+                          :wait wait :save-exit-status (and pipe t))
+                         #+(or clozure cmu ecl sbcl scl)
+                         (#+(or cmu ecl scl) ext:run-program
+                            #+clozure ccl:run-program
+                            #+sbcl sb-ext:run-program
+                            (car command) (cdr command)
+                            :input interactive :wait wait
+                            :output (if pipe :stream t)
+                            . #.(append
+                                 #+(or clozure cmu ecl sbcl scl) '(:error t)
+                                 ;; note: :external-format requires a recent SBCL
+                                 #+sbcl '(:search t :external-format external-format)))))
+                      (process
+                        #+allegro (if pipe (third process*) (first process*))
+                        #+ecl (third process*)
+                        #-(or allegro ecl) (first process*))
+                      (stream
+                        (when pipe
+                          #+(or allegro lispworks ecl) (first process*)
+                          #+clisp (first process*)
+                          #+clozure (ccl::external-process-output process)
+                          #+(or cmu scl) (ext:process-output process)
+                          #+sbcl (sb-ext:process-output process))))
+                 (values process stream)))
+             #+(or allegro clisp clozure cmu ecl (and lispworks os-unix) sbcl scl)
+             (process-result (process pipe)
+               (declare (ignorable pipe))
+               ;; 1- wait
+               #+(and clozure os-unix) (ccl::external-process-wait process)
+               #+(or cmu scl) (ext:process-wait process)
+               #+(and ecl os-unix) (ext:external-process-wait process)
+               #+sbcl (sb-ext:process-wait process)
+               ;; 2- extract result
+               #+allegro (if pipe (sys:reap-os-subprocess :pid process :wait t) process)
+               #+clisp process
+               #+clozure (nth-value 1 (ccl:external-process-status process))
+               #+(or cmu scl) (ext:process-exit-code process)
+               #+ecl (nth-value 1 (ext:external-process-status process))
+               #+lispworks (if pipe (system:pipe-exit-status process :wait t) process)
+               #+sbcl (sb-ext:process-exit-code process))
+             (check-result (exit-code process)
+               #+clisp
+               (setf exit-code
+                     (typecase exit-code (integer exit-code) (null 0) (t -1)))
+               (unless (or ignore-error-status
+                           (equal exit-code 0))
+                 (error 'subprocess-error :command command :code exit-code :process process))
+               exit-code)
+             (use-run-program ()
+               #-(or abcl cormanlisp gcl (and lispworks os-windows) mcl mkcl xcl)
+               (let* ((interactive (eq output :interactive))
+                      (pipe (and output (not interactive))))
+                 (multiple-value-bind (process stream)
+                     (run-program command :pipe pipe :interactive interactive)
+                   (if (and output (not interactive))
+                       (unwind-protect
+                            (slurp-input-stream output stream)
+                         (when stream (close stream))
+                         (check-result (process-result process pipe) process))
+                       (unwind-protect
+                            (check-result
+                             #+(or allegro lispworks) ; when not capturing, returns the exit code!
+                             process
+                             #-(or allegro lispworks) (process-result process pipe)
+                             process))))))
+             (system-command (command)
+               (etypecase command
+                 (string (if (os-windows-p) (format nil "cmd /c ~A" command) command))
+                 (list (escape-shell-command
+                        (if (os-unix-p) (cons "exec" command) command)))))
+             (redirected-system-command (command out)
+               (format nil (if (os-unix-p) "exec > ~*~A ; ~2:*~A" "~A > ~A")
+                       (system-command command) (native-namestring out)))
+             (system (command &key interactive)
+               (declare (ignorable interactive))
+               #+(or abcl xcl) (ext:run-shell-command command)
+               #+allegro
+               (excl:run-shell-command
+                command :input interactive :output interactive :wait t
+                        #+os-windows :show-window #+os-windows (unless (or interactive (eq output t)) :hide))
+               #+(or clisp clozure cmu (and lispworks os-unix) sbcl scl)
+               (process-result (run-program command :pipe nil :interactive interactive) nil)
+               #+ecl (ext:system command)
+               #+cormanlisp (win32:system command)
+               #+gcl (lisp:system command)
+               #+(and lispworks os-windows)
+               (system:call-system-showing-output
+                command :show-cmd (or interactive (eq output t)) :prefix "" :output-stream nil)
+               #+mcl (ccl::with-cstrs ((%command command)) (_system %command))
+               #+mkcl (nth-value 2
+                                 (mkcl:run-program #+windows command #+windows ()
+                                                   #-windows "/bin/sh" (list "-c" command)
+                                                   :input nil :output nil)))
+             (call-system (command-string &key interactive)
+               (check-result (system command-string :interactive interactive) nil))
+             (use-system ()
+               (let ((interactive (eq output :interactive)))
+                 (if (and output (not interactive))
+                     (with-temporary-file (:pathname tmp :direction :output)
+                       (call-system (redirected-system-command command tmp))
+                       (with-open-file (stream tmp
+                                               :direction :input
+                                               :if-does-not-exist :error
+                                               :element-type element-type
+                                               #-gcl2.6 :external-format #-gcl2.6 external-format)
+                         (slurp-input-stream output stream)))
+                     (call-system (system-command command) :interactive interactive)))))
+      (if (and (not force-shell)
+               #+(or clisp ecl) ignore-error-status
+               #+(or abcl cormanlisp gcl (and lispworks os-windows) mcl mkcl xcl) nil)
+          (use-run-program)
+          (use-system)))))
+
+;;;; -------------------------------------------------------------------------
+;;;; Support to build (compile and load) Lisp files
+
+(uiop/package:define-package :uiop/lisp-build
+  (:nicknames :asdf/lisp-build)
+  (:recycle :uiop/lisp-build :asdf/lisp-build :asdf)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility
+   :uiop/os :uiop/pathname :uiop/filesystem :uiop/stream :uiop/image)
+  (:export
+   ;; Variables
+   #:*compile-file-warnings-behaviour* #:*compile-file-failure-behaviour*
+   #:*output-translation-function*
+   #:*optimization-settings* #:*previous-optimization-settings*
+   #:compile-condition #:compile-file-error #:compile-warned-error #:compile-failed-error
+   #:compile-warned-warning #:compile-failed-warning
+   #:check-lisp-compile-results #:check-lisp-compile-warnings
+   #:*uninteresting-conditions* #:*uninteresting-compiler-conditions* #:*uninteresting-loader-conditions*
+   ;; Types
+   #+sbcl #:sb-grovel-unknown-constant-condition
+   ;; Functions & Macros
+   #:get-optimization-settings #:proclaim-optimization-settings
+   #:call-with-muffled-compiler-conditions #:with-muffled-compiler-conditions
+   #:call-with-muffled-loader-conditions #:with-muffled-loader-conditions
+   #:reify-simple-sexp #:unreify-simple-sexp
+   #:reify-deferred-warnings #:unreify-deferred-warnings
+   #:reset-deferred-warnings #:save-deferred-warnings #:check-deferred-warnings
+   #:with-saved-deferred-warnings #:warnings-file-p #:warnings-file-type #:*warnings-file-type*
+   #:enable-deferred-warnings-check #:disable-deferred-warnings-check
+   #:current-lisp-file-pathname #:load-pathname
+   #:lispize-pathname #:compile-file-type #:call-around-hook
+   #:compile-file* #:compile-file-pathname*
+   #:load* #:load-from-string #:combine-fasls)
+  (:intern #:defaults #:failure-p #:warnings-p #:s #:y #:body))
+(in-package :uiop/lisp-build)
+
+(with-upgradability ()
+  (defvar *compile-file-warnings-behaviour*
+    (or #+clisp :ignore :warn)
+    "How should ASDF react if it encounters a warning when compiling a file?
+Valid values are :error, :warn, and :ignore.")
+
+  (defvar *compile-file-failure-behaviour*
+    (or #+(or mkcl sbcl) :error #+clisp :ignore :warn)
+    "How should ASDF react if it encounters a failure (per the ANSI spec of COMPILE-FILE)
+when compiling a file, which includes any non-style-warning warning.
+Valid values are :error, :warn, and :ignore.
+Note that ASDF ALWAYS raises an error if it fails to create an output file when compiling."))
+
+
+;;; Optimization settings
+(with-upgradability ()
+  (defvar *optimization-settings* nil)
+  (defvar *previous-optimization-settings* nil)
+  (defun get-optimization-settings ()
+    "Get current compiler optimization settings, ready to PROCLAIM again"
+    #-(or clisp clozure cmu ecl sbcl scl)
+    (warn "~S does not support ~S. Please help me fix that." 'get-optimization-settings (implementation-type))
+    #+clozure (ccl:declaration-information 'optimize nil)
+    #+(or clisp cmu ecl sbcl scl)
+    (let ((settings '(speed space safety debug compilation-speed #+(or cmu scl) c::brevity)))
+      #.`(loop :for x :in settings
+               ,@(or #+ecl '(:for v :in '(c::*speed* c::*space* c::*safety* c::*debug*))
+                     #+(or cmu scl) '(:for f :in '(c::cookie-speed c::cookie-space c::cookie-safety c::cookie-debug c::cookie-cspeed c::cookie-brevity)))
+               :for y = (or #+clisp (gethash x system::*optimize*)
+                            #+(or ecl) (symbol-value v)
+                            #+(or cmu scl) (funcall f c::*default-cookie*)
+                            #+sbcl (cdr (assoc x sb-c::*policy*)))
+               :when y :collect (list x y))))
+  (defun proclaim-optimization-settings ()
+    "Proclaim the optimization settings in *OPTIMIZATION-SETTINGS*"
+    (proclaim `(optimize ,@*optimization-settings*))
+    (let ((settings (get-optimization-settings)))
+      (unless (equal *previous-optimization-settings* settings)
+        (setf *previous-optimization-settings* settings)))))
+
+
+;;; Condition control
+(with-upgradability ()
+  #+sbcl
+  (progn
+    (defun sb-grovel-unknown-constant-condition-p (c)
+      (and (typep c 'sb-int:simple-style-warning)
+           (string-enclosed-p
+            "Couldn't grovel for "
+            (simple-condition-format-control c)
+            " (unknown to the C compiler).")))
+    (deftype sb-grovel-unknown-constant-condition ()
+      '(and style-warning (satisfies sb-grovel-unknown-constant-condition-p))))
+
+  (defvar *uninteresting-conditions*
+    (append
+     ;;#+clozure '(ccl:compiler-warning)
+     #+cmu '("Deleting unreachable code.")
+     #+lispworks '("~S being redefined in ~A (previously in ~A)."
+                   "~S defined more than once in ~A.") ;; lispworks gets confused by eval-when.
+     #+sbcl
+     '(sb-c::simple-compiler-note
+       "&OPTIONAL and &KEY found in the same lambda list: ~S"
+       #+sb-eval sb-kernel:lexical-environment-too-complex
+       sb-kernel:undefined-alien-style-warning
+       sb-grovel-unknown-constant-condition ; defined above.
+       ;; sb-ext:implicit-generic-function-warning ; Controversial. Let's allow it by default.
+       sb-int:package-at-variance
+       sb-kernel:uninteresting-redefinition
+       ;; BEWARE: the below four are controversial to include here.
+       sb-kernel:redefinition-with-defun
+       sb-kernel:redefinition-with-defgeneric
+       sb-kernel:redefinition-with-defmethod
+       sb-kernel::redefinition-with-defmacro) ; not exported by old SBCLs
+     '("No generic function ~S present when encountering macroexpansion of defmethod. Assuming it will be an instance of standard-generic-function.")) ;; from closer2mop
+    "Conditions that may be skipped while compiling or loading Lisp code.")
+  (defvar *uninteresting-compiler-conditions* '()
+    "Additional conditions that may be skipped while compiling Lisp code.")
+  (defvar *uninteresting-loader-conditions*
+    (append
+     '("Overwriting already existing readtable ~S." ;; from named-readtables
+       #(#:finalizers-off-warning :asdf-finalizers)) ;; from asdf-finalizers
+     #+clisp '(clos::simple-gf-replacing-method-warning))
+    "Additional conditions that may be skipped while loading Lisp code."))
+
+;;;; ----- Filtering conditions while building -----
+(with-upgradability ()
+  (defun call-with-muffled-compiler-conditions (thunk)
+    (call-with-muffled-conditions
+     thunk (append *uninteresting-conditions* *uninteresting-compiler-conditions*)))
+  (defmacro with-muffled-compiler-conditions ((&optional) &body body)
+    "Run BODY where uninteresting compiler conditions are muffled"
+    `(call-with-muffled-compiler-conditions #'(lambda () ,@body)))
+  (defun call-with-muffled-loader-conditions (thunk)
+    (call-with-muffled-conditions
+     thunk (append *uninteresting-conditions* *uninteresting-loader-conditions*)))
+  (defmacro with-muffled-loader-conditions ((&optional) &body body)
+    "Run BODY where uninteresting compiler and additional loader conditions are muffled"
+    `(call-with-muffled-loader-conditions #'(lambda () ,@body))))
+
+
+;;;; Handle warnings and failures
+(with-upgradability ()
+  (define-condition compile-condition (condition)
+    ((context-format
+      :initform nil :reader compile-condition-context-format :initarg :context-format)
+     (context-arguments
+      :initform nil :reader compile-condition-context-arguments :initarg :context-arguments)
+     (description
+      :initform nil :reader compile-condition-description :initarg :description))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<~A~@[ while ~?~]~@:>")
+                       (or (compile-condition-description c) (type-of c))
+                       (compile-condition-context-format c)
+                       (compile-condition-context-arguments c)))))
+  (define-condition compile-file-error (compile-condition error) ())
+  (define-condition compile-warned-warning (compile-condition warning) ())
+  (define-condition compile-warned-error (compile-condition error) ())
+  (define-condition compile-failed-warning (compile-condition warning) ())
+  (define-condition compile-failed-error (compile-condition error) ())
+
+  (defun check-lisp-compile-warnings (warnings-p failure-p
+                                                  &optional context-format context-arguments)
+    (when failure-p
+      (case *compile-file-failure-behaviour*
+        (:warn (warn 'compile-failed-warning
+                     :description "Lisp compilation failed"
+                     :context-format context-format
+                     :context-arguments context-arguments))
+        (:error (error 'compile-failed-error
+                       :description "Lisp compilation failed"
+                       :context-format context-format
+                       :context-arguments context-arguments))
+        (:ignore nil)))
+    (when warnings-p
+      (case *compile-file-warnings-behaviour*
+        (:warn (warn 'compile-warned-warning
+                     :description "Lisp compilation had style-warnings"
+                     :context-format context-format
+                     :context-arguments context-arguments))
+        (:error (error 'compile-warned-error
+                       :description "Lisp compilation had style-warnings"
+                       :context-format context-format
+                       :context-arguments context-arguments))
+        (:ignore nil))))
+
+  (defun check-lisp-compile-results (output warnings-p failure-p
+                                             &optional context-format context-arguments)
+    (unless output
+      (error 'compile-file-error :context-format context-format :context-arguments context-arguments))
+    (check-lisp-compile-warnings warnings-p failure-p context-format context-arguments)))
+
+
+;;;; Deferred-warnings treatment, originally implemented by Douglas Katzman.
+;;;
+;;; To support an implementation, three functions must be implemented:
+;;; reify-deferred-warnings unreify-deferred-warnings reset-deferred-warnings
+;;; See their respective docstrings.
+(with-upgradability ()
+  (defun reify-simple-sexp (sexp)
+    (etypecase sexp
+      (symbol (reify-symbol sexp))
+      ((or number character simple-string pathname) sexp)
+      (cons (cons (reify-simple-sexp (car sexp)) (reify-simple-sexp (cdr sexp))))
+      (simple-vector (vector (mapcar 'reify-simple-sexp (coerce sexp 'list))))))
+
+  (defun unreify-simple-sexp (sexp)
+    (etypecase sexp
+      ((or symbol number character simple-string pathname) sexp)
+      (cons (cons (unreify-simple-sexp (car sexp)) (unreify-simple-sexp (cdr sexp))))
+      ((simple-vector 2) (unreify-symbol sexp))
+      ((simple-vector 1) (coerce (mapcar 'unreify-simple-sexp (aref sexp 0)) 'vector))))
+
+  #+clozure
+  (progn
+    (defun reify-source-note (source-note)
+      (when source-note
+        (with-accessors ((source ccl::source-note-source) (filename ccl:source-note-filename)
+                         (start-pos ccl:source-note-start-pos) (end-pos ccl:source-note-end-pos)) source-note
+          (declare (ignorable source))
+          (list :filename filename :start-pos start-pos :end-pos end-pos
+                #|:source (reify-source-note source)|#))))
+    (defun unreify-source-note (source-note)
+      (when source-note
+        (destructuring-bind (&key filename start-pos end-pos source) source-note
+          (ccl::make-source-note :filename filename :start-pos start-pos :end-pos end-pos
+                                 :source (unreify-source-note source)))))
+    (defun unsymbolify-function-name (name)
+      (if-let (setfed (gethash name ccl::%setf-function-name-inverses%))
+        `(setf ,setfed)
+        name))
+    (defun symbolify-function-name (name)
+      (if (and (consp name) (eq (first name) 'setf))
+          (let ((setfed (second name)))
+            (gethash setfed ccl::%setf-function-names%))
+          name))
+    (defun reify-function-name (function-name)
+      (let ((name (or (first function-name) ;; defun: extract the name
+                      (let ((sec (second function-name)))
+                        (or (and (atom sec) sec) ; scoped method: drop scope
+                            (first sec)))))) ; method: keep gf name, drop method specializers
+        (list name)))
+    (defun unreify-function-name (function-name)
+      function-name)
+    (defun nullify-non-literals (sexp)
+      (typecase sexp
+        ((or number character simple-string symbol pathname) sexp)
+        (cons (cons (nullify-non-literals (car sexp))
+                    (nullify-non-literals (cdr sexp))))
+        (t nil)))
+    (defun reify-deferred-warning (deferred-warning)
+      (with-accessors ((warning-type ccl::compiler-warning-warning-type)
+                       (args ccl::compiler-warning-args)
+                       (source-note ccl:compiler-warning-source-note)
+                       (function-name ccl:compiler-warning-function-name)) deferred-warning
+        (list :warning-type warning-type :function-name (reify-function-name function-name)
+              :source-note (reify-source-note source-note)
+              :args (destructuring-bind (fun &rest more)
+                        args
+                      (cons (unsymbolify-function-name fun)
+                            (nullify-non-literals more))))))
+    (defun unreify-deferred-warning (reified-deferred-warning)
+      (destructuring-bind (&key warning-type function-name source-note args)
+          reified-deferred-warning
+        (make-condition (or (cdr (ccl::assq warning-type ccl::*compiler-whining-conditions*))
+                            'ccl::compiler-warning)
+                        :function-name (unreify-function-name function-name)
+                        :source-note (unreify-source-note source-note)
+                        :warning-type warning-type
+                        :args (destructuring-bind (fun . more) args
+                                (cons (symbolify-function-name fun) more))))))
+  #+(or cmu scl)
+  (defun reify-undefined-warning (warning)
+    ;; Extracting undefined-warnings from the compilation-unit
+    ;; To be passed through the above reify/unreify link, it must be a "simple-sexp"
+    (list*
+     (c::undefined-warning-kind warning)
+     (c::undefined-warning-name warning)
+     (c::undefined-warning-count warning)
+     (mapcar
+      #'(lambda (frob)
+          ;; the lexenv slot can be ignored for reporting purposes
+          `(:enclosing-source ,(c::compiler-error-context-enclosing-source frob)
+            :source ,(c::compiler-error-context-source frob)
+            :original-source ,(c::compiler-error-context-original-source frob)
+            :context ,(c::compiler-error-context-context frob)
+            :file-name ,(c::compiler-error-context-file-name frob) ; a pathname
+            :file-position ,(c::compiler-error-context-file-position frob) ; an integer
+            :original-source-path ,(c::compiler-error-context-original-source-path frob)))
+      (c::undefined-warning-warnings warning))))
+
+  #+sbcl
+  (defun reify-undefined-warning (warning)
+    ;; Extracting undefined-warnings from the compilation-unit
+    ;; To be passed through the above reify/unreify link, it must be a "simple-sexp"
+    (list*
+     (sb-c::undefined-warning-kind warning)
+     (sb-c::undefined-warning-name warning)
+     (sb-c::undefined-warning-count warning)
+     (mapcar
+      #'(lambda (frob)
+          ;; the lexenv slot can be ignored for reporting purposes
+          `(:enclosing-source ,(sb-c::compiler-error-context-enclosing-source frob)
+            :source ,(sb-c::compiler-error-context-source frob)
+            :original-source ,(sb-c::compiler-error-context-original-source frob)
+            :context ,(sb-c::compiler-error-context-context frob)
+            :file-name ,(sb-c::compiler-error-context-file-name frob) ; a pathname
+            :file-position ,(sb-c::compiler-error-context-file-position frob) ; an integer
+            :original-source-path ,(sb-c::compiler-error-context-original-source-path frob)))
+      (sb-c::undefined-warning-warnings warning))))
+
+  (defun reify-deferred-warnings ()
+    "return a portable S-expression, portably readable and writeable in any Common Lisp implementation
+using READ within a WITH-SAFE-IO-SYNTAX, that represents the warnings currently deferred by
+WITH-COMPILATION-UNIT. One of three functions required for deferred-warnings support in ASDF."
+    #+allegro
+    (list :functions-defined excl::.functions-defined.
+	  :functions-called excl::.functions-called.)
+    #+clozure
+    (mapcar 'reify-deferred-warning
+            (if-let (dw ccl::*outstanding-deferred-warnings*)
+              (let ((mdw (ccl::ensure-merged-deferred-warnings dw)))
+                (ccl::deferred-warnings.warnings mdw))))
+    #+(or cmu scl)
+    (when lisp::*in-compilation-unit*
+      ;; Try to send nothing through the pipe if nothing needs to be accumulated
+      `(,@(when c::*undefined-warnings*
+            `((c::*undefined-warnings*
+               ,@(mapcar #'reify-undefined-warning c::*undefined-warnings*))))
+        ,@(loop :for what :in '(c::*compiler-error-count*
+                                c::*compiler-warning-count*
+                                c::*compiler-note-count*)
+                :for value = (symbol-value what)
+                :when (plusp value)
+                  :collect `(,what . ,value))))
+    #+sbcl
+    (when sb-c::*in-compilation-unit*
+      ;; Try to send nothing through the pipe if nothing needs to be accumulated
+      `(,@(when sb-c::*undefined-warnings*
+            `((sb-c::*undefined-warnings*
+               ,@(mapcar #'reify-undefined-warning sb-c::*undefined-warnings*))))
+        ,@(loop :for what :in '(sb-c::*aborted-compilation-unit-count*
+                                sb-c::*compiler-error-count*
+                                sb-c::*compiler-warning-count*
+                                sb-c::*compiler-style-warning-count*
+                                sb-c::*compiler-note-count*)
+                :for value = (symbol-value what)
+                :when (plusp value)
+                  :collect `(,what . ,value)))))
+
+  (defun unreify-deferred-warnings (reified-deferred-warnings)
+    "given a S-expression created by REIFY-DEFERRED-WARNINGS, reinstantiate the corresponding
+deferred warnings as to be handled at the end of the current WITH-COMPILATION-UNIT.
+Handle any warning that has been resolved already,
+such as an undefined function that has been defined since.
+One of three functions required for deferred-warnings support in ASDF."
+    (declare (ignorable reified-deferred-warnings))
+    #+allegro
+    (destructuring-bind (&key functions-defined functions-called)
+			reified-deferred-warnings
+      (setf excl::.functions-defined.
+            (append functions-defined excl::.functions-defined.)
+            excl::.functions-called.
+            (append functions-called excl::.functions-called.)))
+    #+clozure
+    (let ((dw (or ccl::*outstanding-deferred-warnings*
+                  (setf ccl::*outstanding-deferred-warnings* (ccl::%defer-warnings t)))))
+      (appendf (ccl::deferred-warnings.warnings dw)
+               (mapcar 'unreify-deferred-warning reified-deferred-warnings)))
+    #+(or cmu scl)
+    (dolist (item reified-deferred-warnings)
+      ;; Each item is (symbol . adjustment) where the adjustment depends on the symbol.
+      ;; For *undefined-warnings*, the adjustment is a list of initargs.
+      ;; For everything else, it's an integer.
+      (destructuring-bind (symbol . adjustment) item
+        (case symbol
+          ((c::*undefined-warnings*)
+           (setf c::*undefined-warnings*
+                 (nconc (mapcan
+                         #'(lambda (stuff)
+                             (destructuring-bind (kind name count . rest) stuff
+                               (unless (case kind (:function (fboundp name)))
+                                 (list
+                                  (c::make-undefined-warning
+                                   :name name
+                                   :kind kind
+                                   :count count
+                                   :warnings
+                                   (mapcar #'(lambda (x)
+                                               (apply #'c::make-compiler-error-context x))
+                                           rest))))))
+                         adjustment)
+                        c::*undefined-warnings*)))
+          (otherwise
+           (set symbol (+ (symbol-value symbol) adjustment))))))
+    #+sbcl
+    (dolist (item reified-deferred-warnings)
+      ;; Each item is (symbol . adjustment) where the adjustment depends on the symbol.
+      ;; For *undefined-warnings*, the adjustment is a list of initargs.
+      ;; For everything else, it's an integer.
+      (destructuring-bind (symbol . adjustment) item
+        (case symbol
+          ((sb-c::*undefined-warnings*)
+           (setf sb-c::*undefined-warnings*
+                 (nconc (mapcan
+                         #'(lambda (stuff)
+                             (destructuring-bind (kind name count . rest) stuff
+                               (unless (case kind (:function (fboundp name)))
+                                 (list
+                                  (sb-c::make-undefined-warning
+                                   :name name
+                                   :kind kind
+                                   :count count
+                                   :warnings
+                                   (mapcar #'(lambda (x)
+                                               (apply #'sb-c::make-compiler-error-context x))
+                                           rest))))))
+                         adjustment)
+                        sb-c::*undefined-warnings*)))
+          (otherwise
+           (set symbol (+ (symbol-value symbol) adjustment)))))))
+
+  (defun reset-deferred-warnings ()
+    "Reset the set of deferred warnings to be handled at the end of the current WITH-COMPILATION-UNIT.
+One of three functions required for deferred-warnings support in ASDF."
+    #+allegro
+    (setf excl::.functions-defined. nil
+          excl::.functions-called. nil)
+    #+clozure
+    (if-let (dw ccl::*outstanding-deferred-warnings*)
+      (let ((mdw (ccl::ensure-merged-deferred-warnings dw)))
+        (setf (ccl::deferred-warnings.warnings mdw) nil)))
+    #+(or cmu scl)
+    (when lisp::*in-compilation-unit*
+      (setf c::*undefined-warnings* nil
+            c::*compiler-error-count* 0
+            c::*compiler-warning-count* 0
+            c::*compiler-note-count* 0))
+    #+sbcl
+    (when sb-c::*in-compilation-unit*
+      (setf sb-c::*undefined-warnings* nil
+            sb-c::*aborted-compilation-unit-count* 0
+            sb-c::*compiler-error-count* 0
+            sb-c::*compiler-warning-count* 0
+            sb-c::*compiler-style-warning-count* 0
+            sb-c::*compiler-note-count* 0)))
+
+  (defun save-deferred-warnings (warnings-file)
+    "Save forward reference conditions so they may be issued at a latter time,
+possibly in a different process."
+    (with-open-file (s warnings-file :direction :output :if-exists :supersede
+                       :element-type *default-stream-element-type*
+                       :external-format *utf-8-external-format*)
+      (with-safe-io-syntax ()
+        (write (reify-deferred-warnings) :stream s :pretty t :readably t)
+        (terpri s))))
+
+  (defun warnings-file-type (&optional implementation-type)
+    (case (or implementation-type *implementation-type*)
+      ((:acl :allegro) "allegro-warnings")
+      ;;((:clisp) "clisp-warnings")
+      ((:cmu :cmucl) "cmucl-warnings")
+      ((:sbcl) "sbcl-warnings")
+      ((:clozure :ccl) "ccl-warnings")
+      ((:scl) "scl-warnings")))
+
+  (defvar *warnings-file-type* nil
+    "Type for warnings files")
+
+  (defun enable-deferred-warnings-check ()
+    (setf *warnings-file-type* (warnings-file-type)))
+
+  (defun disable-deferred-warnings-check ()
+    (setf *warnings-file-type* nil))
+
+  (defun warnings-file-p (file &optional implementation-type)
+    (if-let (type (if implementation-type
+                      (warnings-file-type implementation-type)
+                      *warnings-file-type*))
+      (equal (pathname-type file) type)))
+
+  (defun check-deferred-warnings (files &optional context-format context-arguments)
+    (let ((file-errors nil)
+          (failure-p nil)
+          (warnings-p nil))
+      (handler-bind
+          ((warning #'(lambda (c)
+                        (setf warnings-p t)
+                        (unless (typep c 'style-warning)
+                          (setf failure-p t)))))
+        (with-compilation-unit (:override t)
+          (reset-deferred-warnings)
+          (dolist (file files)
+            (unreify-deferred-warnings
+             (handler-case (safe-read-file-form file)
+               (error (c)
+                 ;;(delete-file-if-exists file) ;; deleting forces rebuild but prevents debugging
+                 (push c file-errors)
+                 nil))))))
+      (dolist (error file-errors) (error error))
+      (check-lisp-compile-warnings
+       (or failure-p warnings-p) failure-p context-format context-arguments)))
+
+  #|
+  Mini-guide to adding support for deferred warnings on an implementation.
+
+  First, look at what such a warning looks like:
+
+  (describe
+  (handler-case
+  (and (eval '(lambda () (some-undefined-function))) nil)
+  (t (c) c)))
+
+  Then you can grep for the condition type in your compiler sources
+  and see how to catch those that have been deferred,
+  and/or read, clear and restore the deferred list.
+
+  Also look at
+  (macroexpand-1 '(with-compilation-unit () foo))
+  |#
+
+  (defun call-with-saved-deferred-warnings (thunk warnings-file)
+    (if warnings-file
+        (with-compilation-unit (:override t)
+          (unwind-protect
+               (let (#+sbcl (sb-c::*undefined-warnings* nil))
+                 (multiple-value-prog1
+                     (funcall thunk)
+                   (save-deferred-warnings warnings-file)))
+            (reset-deferred-warnings)))
+        (funcall thunk)))
+
+  (defmacro with-saved-deferred-warnings ((warnings-file) &body body)
+    "If WARNINGS-FILE is not nil, records the deferred-warnings around the BODY
+and saves those warnings to the given file for latter use,
+possibly in a different process. Otherwise just run the BODY."
+    `(call-with-saved-deferred-warnings #'(lambda () ,@body) ,warnings-file)))
+
+
+;;; from ASDF
+(with-upgradability ()
+  (defun current-lisp-file-pathname ()
+    (or *compile-file-pathname* *load-pathname*))
+
+  (defun load-pathname ()
+    *load-pathname*)
+
+  (defun lispize-pathname (input-file)
+    (make-pathname :type "lisp" :defaults input-file))
+
+  (defun compile-file-type (&rest keys)
+    "pathname TYPE for lisp FASt Loading files"
+    (declare (ignorable keys))
+    #-(or ecl mkcl) (load-time-value (pathname-type (compile-file-pathname "foo.lisp")))
+    #+(or ecl mkcl) (pathname-type (apply 'compile-file-pathname "foo" keys)))
+
+  (defun call-around-hook (hook function)
+    (call-function (or hook 'funcall) function))
+
+  (defun compile-file-pathname* (input-file &rest keys &key output-file &allow-other-keys)
+    (let* ((keys
+             (remove-plist-keys `(#+(and allegro (not (version>= 8 2))) :external-format
+                                    ,@(unless output-file '(:output-file))) keys)))
+      (if (absolute-pathname-p output-file)
+          ;; what cfp should be doing, w/ mp* instead of mp
+          (let* ((type (pathname-type (apply 'compile-file-type keys)))
+                 (defaults (make-pathname
+                            :type type :defaults (merge-pathnames* input-file))))
+            (merge-pathnames* output-file defaults))
+          (funcall *output-translation-function*
+                   (apply 'compile-file-pathname input-file keys)))))
+
+  (defun* (compile-file*) (input-file &rest keys
+                                      &key compile-check output-file warnings-file
+                                      #+clisp lib-file #+(or ecl mkcl) object-file
+                                      &allow-other-keys)
+    "This function provides a portable wrapper around COMPILE-FILE.
+It ensures that the OUTPUT-FILE value is only returned and
+the file only actually created if the compilation was successful,
+even though your implementation may not do that, and including
+an optional call to an user-provided consistency check function COMPILE-CHECK;
+it will call this function if not NIL at the end of the compilation
+with the arguments sent to COMPILE-FILE*, except with :OUTPUT-FILE TMP-FILE
+where TMP-FILE is the name of a temporary output-file.
+It also checks two flags (with legacy british spelling from ASDF1),
+*COMPILE-FILE-FAILURE-BEHAVIOUR* and *COMPILE-FILE-WARNINGS-BEHAVIOUR*
+with appropriate implementation-dependent defaults,
+and if a failure (respectively warnings) are reported by COMPILE-FILE
+with consider it an error unless the respective behaviour flag
+is one of :SUCCESS :WARN :IGNORE.
+If WARNINGS-FILE is defined, deferred warnings are saved to that file.
+On ECL or MKCL, it creates both the linkable object and loadable fasl files.
+On implementations that erroneously do not recognize standard keyword arguments,
+it will filter them appropriately."
+    #+ecl (when (and object-file (equal (compile-file-type) (pathname object-file)))
+            (format t "Whoa, some funky ASDF upgrade switched ~S calling convention for ~S and ~S~%"
+                    'compile-file* output-file object-file)
+            (rotatef output-file object-file))
+    (let* ((keywords (remove-plist-keys
+                      `(:output-file :compile-check :warnings-file
+                                     #+clisp :lib-file #+(or ecl mkcl) :object-file
+                                     #+gcl2.6 ,@'(:external-format :print :verbose)) keys))
+           (output-file
+             (or output-file
+                 (apply 'compile-file-pathname* input-file :output-file output-file keywords)))
+           #+ecl
+           (object-file
+             (unless (use-ecl-byte-compiler-p)
+               (or object-file
+                   (compile-file-pathname output-file :type :object))))
+           #+mkcl
+           (object-file
+             (or object-file
+                 (compile-file-pathname output-file :fasl-p nil)))
+           (tmp-file (tmpize-pathname output-file))
+           #+clisp
+           (tmp-lib (make-pathname :type "lib" :defaults tmp-file)))
+      (multiple-value-bind (output-truename warnings-p failure-p)
+          (with-saved-deferred-warnings (warnings-file)
+            (with-muffled-compiler-conditions ()
+              (or #-(or ecl mkcl) (apply 'compile-file input-file :output-file tmp-file keywords)
+                  #+ecl (apply 'compile-file input-file :output-file
+                               (if object-file
+                                   (list* object-file :system-p t keywords)
+                                   (list* tmp-file keywords)))
+                  #+mkcl (apply 'compile-file input-file
+                                :output-file object-file :fasl-p nil keywords))))
+        (cond
+          ((and output-truename
+                (flet ((check-flag (flag behaviour)
+                         (or (not flag) (member behaviour '(:success :warn :ignore)))))
+                  (and (check-flag failure-p *compile-file-failure-behaviour*)
+                       (check-flag warnings-p *compile-file-warnings-behaviour*)))
+                (progn
+                  #+(or ecl mkcl)
+                  (when (and #+ecl object-file)
+                    (setf output-truename
+                          (compiler::build-fasl
+                           tmp-file #+ecl :lisp-files #+mkcl :lisp-object-files
+                                    (list object-file))))
+                  (or (not compile-check)
+                      (apply compile-check input-file :output-file tmp-file keywords))))
+           (delete-file-if-exists output-file)
+           (when output-truename
+             #+clisp (when lib-file (rename-file-overwriting-target tmp-lib lib-file))
+             (rename-file-overwriting-target output-truename output-file)
+             (setf output-truename (truename output-file)))
+           #+clisp (delete-file-if-exists tmp-lib))
+          (t ;; error or failed check
+           (delete-file-if-exists output-truename)
+           (setf output-truename nil)))
+        (values output-truename warnings-p failure-p))))
+
+  (defun load* (x &rest keys &key &allow-other-keys)
+    (etypecase x
+      ((or pathname string #-(or allegro clozure gcl2.6 genera) stream)
+       (apply 'load x
+              #-gcl2.6 keys #+gcl2.6 (remove-plist-key :external-format keys)))
+      ;; GCL 2.6, Genera can't load from a string-input-stream
+      ;; ClozureCL 1.6 can only load from file input stream
+      ;; Allegro 5, I don't remember but it must have been broken when I tested.
+      #+(or allegro clozure gcl2.6 genera)
+      (stream ;; make do this way
+       (let ((*package* *package*)
+             (*readtable* *readtable*)
+             (*load-pathname* nil)
+             (*load-truename* nil))
+         (eval-input x)))))
+
+  (defun load-from-string (string)
+    "Portably read and evaluate forms from a STRING."
+    (with-input-from-string (s string) (load* s))))
+
+;;; Links FASLs together
+(with-upgradability ()
+  (defun combine-fasls (inputs output)
+    #-(or abcl allegro clisp clozure cmu lispworks sbcl scl xcl)
+    (error "~A does not support ~S~%inputs ~S~%output  ~S"
+           (implementation-type) 'combine-fasls inputs output)
+    #+abcl (funcall 'sys::concatenate-fasls inputs output) ; requires ABCL 1.2.0
+    #+(or allegro clisp cmu sbcl scl xcl) (concatenate-files inputs output)
+    #+clozure (ccl:fasl-concatenate output inputs :if-exists :supersede)
+    #+lispworks
+    (let (fasls)
+      (unwind-protect
+           (progn
+             (loop :for i :in inputs
+                   :for n :from 1
+                   :for f = (add-pathname-suffix
+                             output (format nil "-FASL~D" n))
+                   :do (copy-file i f)
+                       (push f fasls))
+             (ignore-errors (lispworks:delete-system :fasls-to-concatenate))
+             (eval `(scm:defsystem :fasls-to-concatenate
+                      (:default-pathname ,(pathname-directory-pathname output))
+                      :members
+                      ,(loop :for f :in (reverse fasls)
+                             :collect `(,(namestring f) :load-only t))))
+             (scm:concatenate-system output :fasls-to-concatenate))
+        (loop :for f :in fasls :do (ignore-errors (delete-file f)))
+        (ignore-errors (lispworks:delete-system :fasls-to-concatenate))))))
+
+;;;; ---------------------------------------------------------------------------
+;;;; Generic support for configuration files
+
+(uiop/package:define-package :uiop/configuration
+  (:nicknames :asdf/configuration)
+  (:recycle :uiop/configuration :asdf/configuration :asdf)
+  (:use :uiop/common-lisp :uiop/utility
+   :uiop/os :uiop/pathname :uiop/filesystem :uiop/stream :uiop/image)
+  (:export
+   #:get-folder-path
+   #:user-configuration-directories #:system-configuration-directories
+   #:in-first-directory
+   #:in-user-configuration-directory #:in-system-configuration-directory
+   #:validate-configuration-form #:validate-configuration-file #:validate-configuration-directory
+   #:configuration-inheritance-directive-p
+   #:report-invalid-form #:invalid-configuration #:*ignored-configuration-form* #:*user-cache*
+   #:*clear-configuration-hook* #:clear-configuration #:register-clear-configuration-hook
+   #:resolve-location #:location-designator-p #:location-function-p #:*here-directory*
+   #:resolve-relative-location #:resolve-absolute-location #:upgrade-configuration))
+(in-package :uiop/configuration)
+
+(with-upgradability ()
+  (define-condition invalid-configuration ()
+    ((form :reader condition-form :initarg :form)
+     (location :reader condition-location :initarg :location)
+     (format :reader condition-format :initarg :format)
+     (arguments :reader condition-arguments :initarg :arguments :initform nil))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<~? (will be skipped)~@:>")
+                       (condition-format c)
+                       (list* (condition-form c) (condition-location c)
+                              (condition-arguments c))))))
+
+  (defun get-folder-path (folder)
+    (or ;; this semi-portably implements a subset of the functionality of lispworks' sys:get-folder-path
+        #+(and lispworks mswindows) (sys:get-folder-path folder)
+        ;; read-windows-registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\AppData
+        (ecase folder
+          (:local-appdata (getenv-absolute-directory "LOCALAPPDATA"))
+          (:appdata (getenv-absolute-directory "APPDATA"))
+          (:common-appdata (or (getenv-absolute-directory "ALLUSERSAPPDATA")
+                               (subpathname* (getenv-absolute-directory "ALLUSERSPROFILE") "Application Data/"))))))
+
+  (defun user-configuration-directories ()
+    (let ((dirs
+            `(,@(when (os-unix-p)
+                  (cons
+                   (subpathname* (getenv-absolute-directory "XDG_CONFIG_HOME") "common-lisp/")
+                   (loop :for dir :in (getenv-absolute-directories "XDG_CONFIG_DIRS")
+                         :collect (subpathname* dir "common-lisp/"))))
+              ,@(when (os-windows-p)
+                  `(,(subpathname* (get-folder-path :local-appdata) "common-lisp/config/")
+                    ,(subpathname* (get-folder-path :appdata) "common-lisp/config/")))
+              ,(subpathname (user-homedir-pathname) ".config/common-lisp/"))))
+      (remove-duplicates (remove-if-not #'absolute-pathname-p dirs)
+                         :from-end t :test 'equal)))
+
+  (defun system-configuration-directories ()
+    (cond
+      ((os-unix-p) '(#p"/etc/common-lisp/"))
+      ((os-windows-p)
+       (if-let (it (subpathname* (get-folder-path :common-appdata) "common-lisp/config/"))
+         (list it)))))
+
+  (defun in-first-directory (dirs x &key (direction :input))
+    (loop :with fun = (ecase direction
+                        ((nil :input :probe) 'probe-file*)
+                        ((:output :io) 'identity))
+          :for dir :in dirs
+          :thereis (and dir (funcall fun (merge-pathnames* x (ensure-directory-pathname dir))))))
+
+  (defun in-user-configuration-directory (x &key (direction :input))
+    (in-first-directory (user-configuration-directories) x :direction direction))
+  (defun in-system-configuration-directory (x &key (direction :input))
+    (in-first-directory (system-configuration-directories) x :direction direction))
+
+  (defun configuration-inheritance-directive-p (x)
+    (let ((kw '(:inherit-configuration :ignore-inherited-configuration)))
+      (or (member x kw)
+          (and (length=n-p x 1) (member (car x) kw)))))
+
+  (defun report-invalid-form (reporter &rest args)
+    (etypecase reporter
+      (null
+       (apply 'error 'invalid-configuration args))
+      (function
+       (apply reporter args))
+      ((or symbol string)
+       (apply 'error reporter args))
+      (cons
+       (apply 'apply (append reporter args)))))
+
+  (defvar *ignored-configuration-form* nil)
+
+  (defun validate-configuration-form (form tag directive-validator
+                                            &key location invalid-form-reporter)
+    (unless (and (consp form) (eq (car form) tag))
+      (setf *ignored-configuration-form* t)
+      (report-invalid-form invalid-form-reporter :form form :location location)
+      (return-from validate-configuration-form nil))
+    (loop :with inherit = 0 :with ignore-invalid-p = nil :with x = (list tag)
+          :for directive :in (cdr form)
+          :when (cond
+                  ((configuration-inheritance-directive-p directive)
+                   (incf inherit) t)
+                  ((eq directive :ignore-invalid-entries)
+                   (setf ignore-invalid-p t) t)
+                  ((funcall directive-validator directive)
+                   t)
+                  (ignore-invalid-p
+                   nil)
+                  (t
+                   (setf *ignored-configuration-form* t)
+                   (report-invalid-form invalid-form-reporter :form directive :location location)
+                   nil))
+            :do (push directive x)
+          :finally
+             (unless (= inherit 1)
+               (report-invalid-form invalid-form-reporter
+                                    :arguments (list (compatfmt "~@<One and only one of ~S or ~S is required.~@:>")
+                                                     :inherit-configuration :ignore-inherited-configuration)))
+             (return (nreverse x))))
+
+  (defun validate-configuration-file (file validator &key description)
+    (let ((forms (read-file-forms file)))
+      (unless (length=n-p forms 1)
+        (error (compatfmt "~@<One and only one form allowed for ~A. Got: ~3i~_~S~@:>~%")
+               description forms))
+      (funcall validator (car forms) :location file)))
+
+  (defun validate-configuration-directory (directory tag validator &key invalid-form-reporter)
+    "Map the VALIDATOR across the .conf files in DIRECTORY, the TAG will
+be applied to the results to yield a configuration form.  Current
+values of TAG include :source-registry and :output-translations."
+    (let ((files (sort (ignore-errors
+                        (remove-if
+                         'hidden-pathname-p
+                         (directory* (make-pathname :name *wild* :type "conf" :defaults directory))))
+                       #'string< :key #'namestring)))
+      `(,tag
+        ,@(loop :for file :in files :append
+                                    (loop :with ignore-invalid-p = nil
+                                          :for form :in (read-file-forms file)
+                                          :when (eq form :ignore-invalid-entries)
+                                            :do (setf ignore-invalid-p t)
+                                          :else
+                                            :when (funcall validator form)
+                                              :collect form
+                                          :else
+                                            :when ignore-invalid-p
+                                              :do (setf *ignored-configuration-form* t)
+                                          :else
+                                            :do (report-invalid-form invalid-form-reporter :form form :location file)))
+        :inherit-configuration)))
+
+  (defun resolve-relative-location (x &key ensure-directory wilden)
+    (ensure-pathname
+     (etypecase x
+       (pathname x)
+       (string (parse-unix-namestring
+                x :ensure-directory ensure-directory))
+       (cons
+        (if (null (cdr x))
+            (resolve-relative-location
+             (car x) :ensure-directory ensure-directory :wilden wilden)
+            (let* ((car (resolve-relative-location
+                         (car x) :ensure-directory t :wilden nil)))
+              (merge-pathnames*
+               (resolve-relative-location
+                (cdr x) :ensure-directory ensure-directory :wilden wilden)
+               car))))
+       ((eql :*/) *wild-directory*)
+       ((eql :**/) *wild-inferiors*)
+       ((eql :*.*.*) *wild-file*)
+       ((eql :implementation)
+        (parse-unix-namestring
+         (implementation-identifier) :ensure-directory t))
+       ((eql :implementation-type)
+        (parse-unix-namestring
+         (string-downcase (implementation-type)) :ensure-directory t))
+       ((eql :hostname)
+        (parse-unix-namestring (hostname) :ensure-directory t)))
+     :wilden (and wilden (not (pathnamep x)) (not (member x '(:*/ :**/ :*.*.*))))
+     :want-relative t))
+
+  (defvar *here-directory* nil
+    "This special variable is bound to the currect directory during calls to
+PROCESS-SOURCE-REGISTRY in order that we be able to interpret the :here
+directive.")
+
+  (defvar *user-cache* nil
+    "A specification as per RESOLVE-LOCATION of where the user keeps his FASL cache")
+
+  (defun compute-user-cache ()
+    (setf *user-cache*
+          (flet ((try (x &rest sub) (and x `(,x ,@sub))))
+            (or
+             (try (getenv-absolute-directory "XDG_CACHE_HOME") "common-lisp" :implementation)
+             (when (os-windows-p)
+               (try (or (get-folder-path :local-appdata)
+                        (get-folder-path :appdata))
+                    "common-lisp" "cache" :implementation))
+             '(:home ".cache" "common-lisp" :implementation)))))
+  (register-image-restore-hook 'compute-user-cache)
+
+  (defun resolve-absolute-location (x &key ensure-directory wilden)
+    (ensure-pathname
+     (etypecase x
+       (pathname x)
+       (string
+        (let ((p #-mcl (parse-namestring x)
+                 #+mcl (probe-posix x)))
+          #+mcl (unless p (error "POSIX pathname ~S does not exist" x))
+          (if ensure-directory (ensure-directory-pathname p) p)))
+       (cons
+        (return-from resolve-absolute-location
+          (if (null (cdr x))
+              (resolve-absolute-location
+               (car x) :ensure-directory ensure-directory :wilden wilden)
+              (merge-pathnames*
+               (resolve-relative-location
+                (cdr x) :ensure-directory ensure-directory :wilden wilden)
+               (resolve-absolute-location
+                (car x) :ensure-directory t :wilden nil)))))
+       ((eql :root)
+        ;; special magic! we return a relative pathname,
+        ;; but what it means to the output-translations is
+        ;; "relative to the root of the source pathname's host and device".
+        (return-from resolve-absolute-location
+          (let ((p (make-pathname* :directory '(:relative))))
+            (if wilden (wilden p) p))))
+       ((eql :home) (user-homedir-pathname))
+       ((eql :here) (resolve-absolute-location
+                     *here-directory* :ensure-directory t :wilden nil))
+       ((eql :user-cache) (resolve-absolute-location
+                           *user-cache* :ensure-directory t :wilden nil)))
+     :wilden (and wilden (not (pathnamep x)))
+     :resolve-symlinks *resolve-symlinks*
+     :want-absolute t))
+
+  ;; Try to override declaration in previous versions of ASDF.
+  (declaim (ftype (function (t &key (:directory boolean) (:wilden boolean)
+                               (:ensure-directory boolean)) t) resolve-location))
+
+  (defun* (resolve-location) (x &key ensure-directory wilden directory)
+    ;; :directory backward compatibility, until 2014-01-16: accept directory as well as ensure-directory
+    (loop* :with dirp = (or directory ensure-directory)
+           :with (first . rest) = (if (atom x) (list x) x)
+           :with path = (resolve-absolute-location
+                         first :ensure-directory (and (or dirp rest) t)
+                               :wilden (and wilden (null rest)))
+           :for (element . morep) :on rest
+           :for dir = (and (or morep dirp) t)
+           :for wild = (and wilden (not morep))
+           :for sub = (merge-pathnames*
+                       (resolve-relative-location
+                        element :ensure-directory dir :wilden wild)
+                       path)
+           :do (setf path (if (absolute-pathname-p sub) (resolve-symlinks* sub) sub))
+           :finally (return path)))
+
+  (defun location-designator-p (x)
+    (flet ((absolute-component-p (c)
+             (typep c '(or string pathname
+                        (member :root :home :here :user-cache))))
+           (relative-component-p (c)
+             (typep c '(or string pathname
+                        (member :*/ :**/ :*.*.* :implementation :implementation-type)))))
+      (or (typep x 'boolean)
+          (absolute-component-p x)
+          (and (consp x) (absolute-component-p (first x)) (every #'relative-component-p (rest x))))))
+
+  (defun location-function-p (x)
+    (and
+     (length=n-p x 2)
+     (eq (car x) :function)
+     (or (symbolp (cadr x))
+         (and (consp (cadr x))
+              (eq (caadr x) 'lambda)
+              (length=n-p (cadadr x) 2)))))
+
+  (defvar *clear-configuration-hook* '())
+
+  (defun register-clear-configuration-hook (hook-function &optional call-now-p)
+    (register-hook-function '*clear-configuration-hook* hook-function call-now-p))
+
+  (defun clear-configuration ()
+    (call-functions *clear-configuration-hook*))
+
+  (register-image-dump-hook 'clear-configuration)
+
+  ;; If a previous version of ASDF failed to read some configuration, try again.
+  (defun upgrade-configuration ()
+    (when *ignored-configuration-form*
+      (clear-configuration)
+      (setf *ignored-configuration-form* nil))))
+
+
+;;;; -------------------------------------------------------------------------
+;;; Hacks for backward-compatibility of the driver
+
+(uiop/package:define-package :uiop/backward-driver
+  (:nicknames :asdf/backward-driver)
+  (:recycle :uiop/backward-driver :asdf/backward-driver :asdf)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility
+   :uiop/pathname :uiop/stream :uiop/os :uiop/image
+   :uiop/run-program :uiop/lisp-build
+   :uiop/configuration)
+  (:export
+   #:coerce-pathname #:component-name-to-pathname-components
+   #+(or ecl mkcl) #:compile-file-keeping-object
+   ))
+(in-package :uiop/backward-driver)
+
+;;;; Backward compatibility with various pathname functions.
+
+(with-upgradability ()
+  (defun coerce-pathname (name &key type defaults)
+    ;; For backward-compatibility only, for people using internals
+    ;; Reported users in quicklisp: hu.dwim.asdf, asdf-utils, xcvb
+    ;; Will be removed after 2014-01-16.
+    ;;(warn "Please don't use ASDF::COERCE-PATHNAME. Use ASDF/PATHNAME:PARSE-UNIX-NAMESTRING.")
+    (parse-unix-namestring name :type type :defaults defaults))
+
+  (defun component-name-to-pathname-components (unix-style-namestring
+                                                 &key force-directory force-relative)
+    ;; Will be removed after 2014-01-16.
+    ;; (warn "Please don't use ASDF::COMPONENT-NAME-TO-PATHNAME-COMPONENTS, use SPLIT-UNIX-NAMESTRING-DIRECTORY-COMPONENTS")
+    (multiple-value-bind (relabs path filename file-only)
+        (split-unix-namestring-directory-components
+         unix-style-namestring :ensure-directory force-directory)
+      (declare (ignore file-only))
+      (when (and force-relative (not (eq relabs :relative)))
+        (error (compatfmt "~@<Absolute pathname designator not allowed: ~3i~_~S~@:>")
+               unix-style-namestring))
+      (values relabs path filename)))
+
+  #+(or ecl mkcl)
+  (defun compile-file-keeping-object (&rest args) (apply #'compile-file* args)))
+;;;; ---------------------------------------------------------------------------
+;;;; Re-export all the functionality in asdf/driver
+
+(uiop/package:define-package :uiop/driver
+  (:nicknames :uiop :asdf/driver :asdf-driver :asdf-utils)
+  (:use :uiop/common-lisp :uiop/package :uiop/utility
+    :uiop/os :uiop/pathname :uiop/stream :uiop/filesystem :uiop/image
+   :uiop/run-program :uiop/lisp-build
+   :uiop/configuration :uiop/backward-driver)
+  (:reexport
+   ;; NB: excluding asdf/common-lisp
+   ;; which include all of CL with compatibility modifications on select platforms.
+   :uiop/package :uiop/utility
+   :uiop/os :uiop/pathname :uiop/stream :uiop/filesystem :uiop/image
+   :uiop/run-program :uiop/lisp-build
+   :uiop/configuration :uiop/backward-driver))
+;;;; -------------------------------------------------------------------------
+;;;; Handle upgrade as forward- and backward-compatibly as possible
+;; See https://bugs.launchpad.net/asdf/+bug/485687
+
+(asdf/package:define-package :asdf/upgrade
+  (:recycle :asdf/upgrade :asdf)
+  (:use :asdf/common-lisp :asdf/driver)
+  (:export
+   #:asdf-version #:*previous-asdf-versions* #:*asdf-version*
+   #:asdf-message #:*verbose-out*
+   #:upgrading-p #:when-upgrading #:upgrade-asdf #:asdf-upgrade-error
+   #:*post-upgrade-cleanup-hook* #:*post-upgrade-restart-hook* #:cleanup-upgraded-asdf
+   ;; There will be no symbol left behind!
+   #:intern*)
+  (:import-from :asdf/package #:intern* #:find-symbol*))
+(in-package :asdf/upgrade)
+
+;;; Special magic to detect if this is an upgrade
+
+(with-upgradability ()
+  (defun asdf-version ()
+    "Exported interface to the version of ASDF currently installed. A string.
+You can compare this string with e.g.: (ASDF:VERSION-SATISFIES (ASDF:ASDF-VERSION) \"3.4.5.67\")."
+    (when (find-package :asdf)
+      (or (symbol-value (find-symbol (string :*asdf-version*) :asdf))
+          (let* ((revsym (find-symbol (string :*asdf-revision*) :asdf))
+                 (rev (and revsym (boundp revsym) (symbol-value revsym))))
+            (etypecase rev
+              (string rev)
+              (cons (format nil "~{~D~^.~}" rev))
+              (null "1.0"))))))
+  (defvar *asdf-version* nil)
+  (defvar *previous-asdf-versions* nil)
+  (defvar *verbose-out* nil)
+  (defun asdf-message (format-string &rest format-args)
+    (when *verbose-out* (apply 'format *verbose-out* format-string format-args)))
+  (defvar *post-upgrade-cleanup-hook* ())
+  (defvar *post-upgrade-restart-hook* ())
+  (defun upgrading-p ()
+    (and *previous-asdf-versions* (not (equal *asdf-version* (first *previous-asdf-versions*)))))
+  (defmacro when-upgrading ((&key (upgrading-p '(upgrading-p)) when) &body body)
+    `(with-upgradability ()
+       (when (and ,upgrading-p ,@(when when `(,when)))
+         (handler-bind ((style-warning #'muffle-warning))
+           (eval '(progn ,@body))))))
+  (let* (;; For bug reporting sanity, please always bump this version when you modify this file.
+         ;; Please also modify asdf.asd to reflect this change. make bump-version v=3.4.5.67.8
+         ;; can help you do these changes in synch (look at the source for documentation).
+         ;; Relying on its automation, the version is now redundantly present on top of this file.
+         ;; "3.4" would be the general branch for major version 3, minor version 4.
+         ;; "3.4.5" would be an official release in the 3.4 branch.
+         ;; "3.4.5.67" would be a development version in the official upstream of 3.4.5.
+         ;; "3.4.5.0.8" would be your eighth local modification of official release 3.4.5
+         ;; "3.4.5.67.8" would be your eighth local modification of development version 3.4.5.67
+         (asdf-version "2.33")
+         (existing-version (asdf-version)))
+    (setf *asdf-version* asdf-version)
+    (when (and existing-version (not (equal asdf-version existing-version)))
+      (push existing-version *previous-asdf-versions*)
+      (when (or *load-verbose* *verbose-out*)
+        (format *trace-output*
+                (compatfmt "~&~@<; ~@;Upgrading ASDF ~@[from version ~A ~]to version ~A~@:>~%")
+                existing-version asdf-version)))))
+
+(when-upgrading ()
+  (let ((redefined-functions ;; gf signature and/or semantics changed incompatibly. Oops.
+          '(#:component-relative-pathname #:component-parent-pathname ;; component
+            #:source-file-type
+            #:find-system #:system-source-file #:system-relative-pathname ;; system
+             #:find-component ;; find-component
+             #:explain #:perform #:perform-with-restarts #:input-files #:output-files ;; action
+             #:component-depends-on #:operation-done-p #:component-depends-on
+             #:traverse ;; plan
+             #:operate  ;; operate
+             #:parse-component-form ;; defsystem
+             #:apply-output-translations ;; output-translations
+             #:process-output-translations-directive
+             #:inherit-source-registry #:process-source-registry ;; source-registry
+             #:process-source-registry-directive
+             #:trivial-system-p ;; bundle
+             ;; NB: it's too late to do anything about asdf-driver functions!
+             ))
+         (uninterned-symbols
+           '(#:*asdf-revision* #:around #:asdf-method-combination
+             #:split #:make-collector #:do-dep #:do-one-dep
+             #:component-self-dependencies
+             #:resolve-relative-location-component #:resolve-absolute-location-component
+             #:output-files-for-system-and-operation))) ; obsolete ASDF-BINARY-LOCATION function
+    (declare (ignorable redefined-functions uninterned-symbols))
+    (loop :for name :in (append redefined-functions)
+          :for sym = (find-symbol* name :asdf nil) :do
+            (when sym
+              ;; On CLISP we seem to be unable to fmakunbound and define a function in the same fasl. Sigh.
+              #-clisp (fmakunbound sym)))
+    (loop :with asdf = (find-package :asdf)
+          :for name :in uninterned-symbols
+          :for sym = (find-symbol* name :asdf nil)
+          :for base-pkg = (and sym (symbol-package sym)) :do
+            (when sym
+              (cond
+                ((or (eq base-pkg asdf) (not base-pkg))
+                 (unintern* sym asdf)
+                 (intern* sym asdf))
+                (t
+                 (unintern* sym base-pkg)
+                 (let ((new (intern* sym base-pkg)))
+                   (shadowing-import new asdf))))))))
+
+
+;;; Self-upgrade functions
+
+(with-upgradability ()
+  (defun asdf-upgrade-error ()
+    ;; Important notice for whom it concerns. The crux of the matter is that
+    ;; TRAVERSE can be completely refactored, and so after the find-system returns, it's too late.
+    (error "When a system transitively depends on ASDF, it must :defsystem-depends-on (:asdf)~%~
+          Otherwise, when you upgrade from ASDF 2, you must do it before you operate on any system.~%"))
+
+  (defun cleanup-upgraded-asdf (&optional (old-version (first *previous-asdf-versions*)))
+    (let ((new-version (asdf-version)))
+      (unless (equal old-version new-version)
+        (push new-version *previous-asdf-versions*)
+        (when old-version
+          (if (version<= new-version old-version)
+              (error (compatfmt "~&~@<; ~@;Downgraded ASDF from version ~A to version ~A~@:>~%")
+                     old-version new-version)
+              (asdf-message (compatfmt "~&~@<; ~@;Upgraded ASDF from version ~A to version ~A~@:>~%")
+                            old-version new-version))
+          (call-functions (reverse *post-upgrade-cleanup-hook*))
+          t))))
+
+  (defun upgrade-asdf ()
+    "Try to upgrade of ASDF. If a different version was used, return T.
+   We need do that before we operate on anything that may possibly depend on ASDF."
+    (let ((*load-print* nil)
+          (*compile-print* nil))
+      (handler-bind (((or style-warning) #'muffle-warning))
+        (symbol-call :asdf :load-system :asdf :verbose nil))))
+
+  (register-hook-function '*post-upgrade-cleanup-hook* 'upgrade-configuration))
+
+;;;; -------------------------------------------------------------------------
+;;;; Components
+
+(asdf/package:define-package :asdf/component
+  (:recycle :asdf/component :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade)
+  (:export
+   #:component #:component-find-path
+   #:component-name #:component-pathname #:component-relative-pathname
+   #:component-parent #:component-system #:component-parent-pathname
+   #:child-component #:parent-component #:module
+   #:file-component
+   #:source-file #:c-source-file #:java-source-file
+   #:static-file #:doc-file #:html-file
+   #:file-type
+   #:source-file-type #:source-file-explicit-type ;; backward-compatibility
+   #:component-in-order-to #:component-sideway-dependencies
+   #:component-if-feature #:around-compile-hook
+   #:component-description #:component-long-description
+   #:component-version #:version-satisfies
+   #:component-inline-methods ;; backward-compatibility only. DO NOT USE!
+   #:component-operation-times ;; For internal use only.
+   ;; portable ASDF encoding and implementation-specific external-format
+   #:component-external-format #:component-encoding
+   #:component-children-by-name #:component-children #:compute-children-by-name
+   #:component-build-operation
+   #:module-default-component-class
+   #:module-components ;; backward-compatibility. DO NOT USE.
+   #:sub-components
+
+   ;; Internals we'd like to share with the ASDF package, especially for upgrade purposes
+   #:name #:version #:description #:long-description #:author #:maintainer #:licence
+   #:components-by-name #:components
+   #:children #:children-by-name #:default-component-class
+   #:author #:maintainer #:licence #:source-file #:defsystem-depends-on
+   #:sideway-dependencies #:if-feature #:in-order-to #:inline-methods
+   #:relative-pathname #:absolute-pathname #:operation-times #:around-compile
+   #:%encoding #:properties #:component-properties #:parent))
+(in-package :asdf/component)
+
+(with-upgradability ()
+  (defgeneric component-name (component)
+    (:documentation "Name of the COMPONENT, unique relative to its parent"))
+  (defgeneric component-system (component)
+    (:documentation "Find the top-level system containing COMPONENT"))
+  (defgeneric component-pathname (component)
+    (:documentation "Extracts the pathname applicable for a particular component."))
+  (defgeneric (component-relative-pathname) (component)
+    (:documentation "Returns a pathname for the component argument intended to be
 interpreted relative to the pathname of that component's parent.
 Despite the function's name, the return value may be an absolute
 pathname, because an absolute pathname may be interpreted relative to
 another pathname in a degenerate way."))
-
-(defgeneric* component-property (component property))
-
-(defgeneric* (setf component-property) (new-value component property))
-
-(defgeneric* version-satisfies (component version))
-
-(defgeneric* find-component (base path)
-  (:documentation "Finds the component with PATH starting from BASE module;
-if BASE is nil, then the component is assumed to be a system."))
-
-(defgeneric* source-file-type (component system))
-
-(defgeneric* operation-ancestor (operation)
-  (:documentation
-   "Recursively chase the operation's parent pointer until we get to
-the head of the tree"))
-
-(defgeneric* component-visited-p (operation component)
-  (:documentation "Returns the value stored by a call to
-VISIT-COMPONENT, if that has been called, otherwise NIL.
-This value stored will be a cons cell, the first element
-of which is a computed key, so not interesting.  The
-CDR wil be the DATA value stored by VISIT-COMPONENT; recover
-it as (cdr (component-visited-p op c)).
-  In the current form of ASDF, the DATA value retrieved is
-effectively a boolean, indicating whether some operations are
-to be performed in order to do OPERATION X COMPONENT.  If the
-data value is NIL, the combination had been explored, but no
-operations needed to be performed."))
-
-(defgeneric* visit-component (operation component data)
-  (:documentation "Record DATA as being associated with OPERATION
-and COMPONENT.  This is a side-effecting function:  the association
-will be recorded on the ROOT OPERATION \(OPERATION-ANCESTOR of the
-OPERATION\).
-  No evidence that DATA is ever interesting, beyond just being
-non-NIL.  Using the data field is probably very risky; if there is
-already a record for OPERATION X COMPONENT, DATA will be quietly
-discarded instead of recorded.
-  Starting with 2.006, TRAVERSE will store an integer in data,
-so that nodes can be sorted in decreasing order of traversal."))
-
-
-(defgeneric* (setf visiting-component) (new-value operation component))
-
-(defgeneric* component-visiting-p (operation component))
-
-(defgeneric* component-depends-on (operation component)
-  (:documentation
-   "Returns a list of dependencies needed by the component to perform
-    the operation.  A dependency has one of the following forms:
-
-      (<operation> <component>*), where <operation> is a class
-        designator and each <component> is a component
-        designator, which means that the component depends on
-        <operation> having been performed on each <component>; or
-
-      (FEATURE <feature>), which means that the component depends
-        on <feature>'s presence in *FEATURES*.
-
-    Methods specialized on subclasses of existing component types
-    should usually append the results of CALL-NEXT-METHOD to the
-    list."))
-
-(defgeneric* component-self-dependencies (operation component))
-
-(defgeneric* traverse (operation component)
-  (:documentation
-"Generate and return a plan for performing OPERATION on COMPONENT.
-
-The plan returned is a list of dotted-pairs. Each pair is the CONS
-of ASDF operation object and a COMPONENT object. The pairs will be
-processed in order by OPERATE."))
-
+  (defgeneric component-external-format (component))
+  (defgeneric component-encoding (component))
+  (defgeneric version-satisfies (component version))
+  (defgeneric component-version (component))
+  (defgeneric (setf component-version) (new-version component))
+  (defgeneric component-parent (component))
+  (defmethod component-parent ((component null)) (declare (ignorable component)) nil)
+
+  ;; Backward compatible way of computing the FILE-TYPE of a component.
+  ;; TODO: find users, have them stop using that, remove it for ASDF4.
+  (defgeneric (source-file-type) (component system)))
+
+(when-upgrading (:when (find-class 'component nil))
+  (defmethod reinitialize-instance :after ((c component) &rest initargs &key)
+    (declare (ignorable c initargs)) (values)))
+
+(with-upgradability ()
+  (defclass component ()
+    ((name :accessor component-name :initarg :name :type string :documentation
+           "Component name: designator for a string composed of portable pathname characters")
+     ;; We might want to constrain version with
+     ;; :type (and string (satisfies parse-version))
+     ;; but we cannot until we fix all systems that don't use it correctly!
+     (version :accessor component-version :initarg :version :initform nil)
+     (description :accessor component-description :initarg :description :initform nil)
+     (long-description :accessor component-long-description :initarg :long-description :initform nil)
+     (sideway-dependencies :accessor component-sideway-dependencies :initform nil)
+     (if-feature :accessor component-if-feature :initform nil :initarg :if-feature)
+     ;; In the ASDF object model, dependencies exist between *actions*,
+     ;; where an action is a pair of an operation and a component.
+     ;; Dependencies are represented as alists of operations
+     ;; to a list where each entry is a pair of an operation and a list of component specifiers.
+     ;; Up until ASDF 2.26.9, there used to be two kinds of dependencies:
+     ;; in-order-to and do-first, each stored in its own slot. Now there is only in-order-to.
+     ;; in-order-to used to represent things that modify the filesystem (such as compiling a fasl)
+     ;; and do-first things that modify the current image (such as loading a fasl).
+     ;; These are now unified because we now correctly propagate timestamps between dependencies.
+     ;; Happily, no one seems to have used do-first too much (especially since until ASDF 2.017,
+     ;; anything you specified was overridden by ASDF itself anyway), but the name in-order-to remains.
+     ;; The names are bad, but they have been the official API since Dan Barlow's ASDF 1.52!
+     ;; LispWorks's defsystem has caused-by and requires for in-order-to and do-first respectively.
+     ;; Maybe rename the slots in ASDF? But that's not very backward-compatible.
+     ;; See our ASDF 2 paper for more complete explanations.
+     (in-order-to :initform nil :initarg :in-order-to
+                  :accessor component-in-order-to)
+     ;; methods defined using the "inline" style inside a defsystem form:
+     ;; need to store them somewhere so we can delete them when the system
+     ;; is re-evaluated.
+     (inline-methods :accessor component-inline-methods :initform nil) ;; OBSOLETE! DELETE THIS IF NO ONE USES.
+     ;; ASDF4: rename it from relative-pathname to specified-pathname. It need not be relative.
+     ;; There is no initform and no direct accessor for this specified pathname,
+     ;; so we only access the information through appropriate methods, after it has been processed.
+     ;; Unhappily, some braindead systems directly access the slot. Make them stop before ASDF4.
+     (relative-pathname :initarg :pathname)
+     ;; The absolute-pathname is computed based on relative-pathname and parent pathname.
+     ;; The slot is but a cache used by component-pathname.
+     (absolute-pathname)
+     (operation-times :initform (make-hash-table)
+                      :accessor component-operation-times)
+     (around-compile :initarg :around-compile)
+     ;; Properties are for backward-compatibility with ASDF2 only. DO NOT USE!
+     (properties :accessor component-properties :initarg :properties
+                 :initform nil)
+     (%encoding :accessor %component-encoding :initform nil :initarg :encoding)
+     ;; For backward-compatibility, this slot is part of component rather than of child-component. ASDF4: stop it.
+     (parent :initarg :parent :initform nil :reader component-parent)
+     (build-operation
+      :initarg :build-operation :initform nil :reader component-build-operation)))
+
+  (defun component-find-path (component)
+    (check-type component (or null component))
+    (reverse
+     (loop :for c = component :then (component-parent c)
+           :while c :collect (component-name c))))
+
+  (defmethod print-object ((c component) stream)
+    (print-unreadable-object (c stream :type t :identity nil)
+      (format stream "~{~S~^ ~}" (component-find-path c))))
+
+  (defmethod component-system ((component component))
+    (if-let (system (component-parent component))
+      (component-system system)
+      component)))
+
+
+;;;; Component hierarchy within a system
+;; The tree typically but not necessarily follows the filesystem hierarchy.
+(with-upgradability ()
+  (defclass child-component (component) ())
+
+  (defclass file-component (child-component)
+    ((type :accessor file-type :initarg :type))) ; no default
+  (defclass source-file (file-component)
+    ((type :accessor source-file-explicit-type ;; backward-compatibility
+           :initform nil))) ;; NB: many systems have come to rely on this default.
+  (defclass c-source-file (source-file)
+    ((type :initform "c")))
+  (defclass java-source-file (source-file)
+    ((type :initform "java")))
+  (defclass static-file (source-file)
+    ((type :initform nil)))
+  (defclass doc-file (static-file) ())
+  (defclass html-file (doc-file)
+    ((type :initform "html")))
+
+  (defclass parent-component (component)
+    ((children
+      :initform nil
+      :initarg :components
+      :reader module-components ; backward-compatibility
+      :accessor component-children)
+     (children-by-name
+      :reader module-components-by-name ; backward-compatibility
+      :accessor component-children-by-name)
+     (default-component-class
+      :initform nil
+      :initarg :default-component-class
+      :accessor module-default-component-class))))
+
+(with-upgradability ()
+  (defun compute-children-by-name (parent &key only-if-needed-p)
+    (unless (and only-if-needed-p (slot-boundp parent 'children-by-name))
+      (let ((hash (make-hash-table :test 'equal)))
+        (setf (component-children-by-name parent) hash)
+        (loop :for c :in (component-children parent)
+              :for name = (component-name c)
+              :for previous = (gethash name hash)
+              :do (when previous (error 'duplicate-names :name name))
+                  (setf (gethash name hash) c))
+        hash))))
+
+(when-upgrading (:when (find-class 'module nil))
+  (defmethod reinitialize-instance :after ((m module) &rest initargs &key)
+    (declare (ignorable m initargs)) (values))
+  (defmethod update-instance-for-redefined-class :after
+      ((m module) added deleted plist &key)
+    (declare (ignorable m added deleted plist))
+    (when (and (member 'children added) (member 'components deleted))
+      (setf (slot-value m 'children)
+            ;; old ECLs provide an alist instead of a plist(!)
+            (if (or #+ecl (consp (first plist))) (or #+ecl (cdr (assoc 'components plist)))
+                (getf plist 'components)))
+      (compute-children-by-name m))))
+
+(with-upgradability ()
+  (defclass module (child-component parent-component)
+    (#+clisp (components)))) ;; backward compatibility during upgrade only
+
+
+;;;; component pathnames
+(with-upgradability ()
+  (defgeneric* (component-parent-pathname) (component))
+  (defmethod component-parent-pathname (component)
+    (component-pathname (component-parent component)))
+
+  (defmethod component-pathname ((component component))
+    (if (slot-boundp component 'absolute-pathname)
+        (slot-value component 'absolute-pathname)
+        (let ((pathname
+                (merge-pathnames*
+                 (component-relative-pathname component)
+                 (pathname-directory-pathname (component-parent-pathname component)))))
+          (unless (or (null pathname) (absolute-pathname-p pathname))
+            (error (compatfmt "~@<Invalid relative pathname ~S for component ~S~@:>")
+                   pathname (component-find-path component)))
+          (setf (slot-value component 'absolute-pathname) pathname)
+          pathname)))
+
+  (defmethod component-relative-pathname ((component component))
+    ;; source-file-type is backward-compatibility with ASDF1;
+    ;; we ought to be able to extract this from the component alone with COMPONENT-TYPE.
+    ;; TODO: track who uses it, and have them not use it anymore.
+    (parse-unix-namestring
+     (or (and (slot-boundp component 'relative-pathname)
+              (slot-value component 'relative-pathname))
+         (component-name component))
+     :want-relative t
+     :type (source-file-type component (component-system component))
+     :defaults (component-parent-pathname component)))
+
+  (defmethod source-file-type ((component parent-component) system)
+    (declare (ignorable component system))
+    :directory)
+
+  (defmethod source-file-type ((component file-component) system)
+    (declare (ignorable system))
+    (file-type component)))
+
+
+;;;; Encodings
+(with-upgradability ()
+  (defmethod component-encoding ((c component))
+    (or (loop :for x = c :then (component-parent x)
+              :while x :thereis (%component-encoding x))
+        (detect-encoding (component-pathname c))))
+
+  (defmethod component-external-format ((c component))
+    (encoding-external-format (component-encoding c))))
+
+
+;;;; around-compile-hook
+(with-upgradability ()
+  (defgeneric around-compile-hook (component))
+  (defmethod around-compile-hook ((c component))
+    (cond
+      ((slot-boundp c 'around-compile)
+       (slot-value c 'around-compile))
+      ((component-parent c)
+       (around-compile-hook (component-parent c))))))
+
+
+;;;; version-satisfies
+(with-upgradability ()
+  (defmethod version-satisfies ((c component) version)
+    (unless (and version (slot-boundp c 'version))
+      (when version
+        (warn "Requested version ~S but component ~S has no version" version c))
+      (return-from version-satisfies t))
+    (version-satisfies (component-version c) version))
+
+  (defmethod version-satisfies ((cver string) version)
+    (version-compatible-p cver version)))
+
+
+;;; all sub-components (of a given type)
+(with-upgradability ()
+  (defun sub-components (component &key (type t))
+    (while-collecting (c)
+      (labels ((recurse (x)
+                 (when (if-let (it (component-if-feature x)) (featurep it) t)
+                   (when (typep x type)
+                     (c x))
+                   (when (typep x 'parent-component)
+                     (map () #'recurse (component-children x))))))
+        (recurse component)))))
 
 ;;;; -------------------------------------------------------------------------
-;;; Methods in case of hot-upgrade. See https://bugs.launchpad.net/asdf/+bug/485687
-(when *upgraded-p*
-   #+ecl
-   (when (find-class 'compile-op nil)
-     (defmethod update-instance-for-redefined-class :after
-         ((c compile-op) added deleted plist &key)
-       (declare (ignore added deleted))
-       (let ((system-p (getf plist 'system-p)))
-         (when system-p (setf (getf (slot-value c 'flags) :system-p) system-p)))))
-   (when (find-class 'module nil)
-     (eval
-      `(defmethod update-instance-for-redefined-class :after
-           ((m module) added deleted plist &key)
-         (declare (ignorable deleted plist))
-         (when (or *asdf-verbose* *load-verbose*)
-           (asdf-message "~&~@<; ~@; Updating ~A for ASDF ~A~@:>~%" m ,(asdf-version)))
-         (when (member 'components-by-name added)
-           (compute-module-components-by-name m))
-         (when (and (typep m 'system) (member 'source-file added))
-           (%set-system-source-file (probe-asd (component-name m) (component-pathname m)) m))))))
+;;;; Systems
+
+(asdf/package:define-package :asdf/system
+  (:recycle :asdf :asdf/system)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade :asdf/component)
+  (:export
+   #:system #:proto-system
+   #:system-source-file #:system-source-directory #:system-relative-pathname
+   #:reset-system
+   #:system-description #:system-long-description
+   #:system-author #:system-maintainer #:system-licence #:system-license
+   #:system-defsystem-depends-on
+   #:component-build-pathname #:build-pathname
+   #:component-entry-point #:entry-point
+   #:homepage #:system-homepage
+   #:bug-tracker #:system-bug-tracker
+   #:mailto #:system-mailto
+   #:long-name #:system-long-name
+   #:source-control #:system-source-control
+   #:find-system #:builtin-system-p)) ;; forward-reference, defined in find-system
+(in-package :asdf/system)
+
+(with-upgradability ()
+  (defgeneric* (find-system) (system &optional error-p))
+  (defgeneric* (system-source-file) (system)
+    (:documentation "Return the source file in which system is defined."))
+  (defgeneric component-build-pathname (component))
+
+  (defgeneric component-entry-point (component))
+  (defmethod component-entry-point ((c component))
+    (declare (ignorable c))
+    nil))
+
+
+;;;; The system class
+
+(with-upgradability ()
+  (defclass proto-system () ; slots to keep when resetting a system
+    ;; To preserve identity for all objects, we'd need keep the components slots
+    ;; but also to modify parse-component-form to reset the recycled objects.
+    ((name) (source-file) #|(children) (children-by-names)|#))
+
+  (defclass system (module proto-system)
+    ;; Backward-compatibility: inherit from module. ASDF4: only inherit from parent-component.
+    (;; {,long-}description is now inherited from component, but we add the legacy accessors
+     (description :accessor system-description)
+     (long-description :accessor system-long-description)
+     (author :accessor system-author :initarg :author :initform nil)
+     (maintainer :accessor system-maintainer :initarg :maintainer :initform nil)
+     (licence :accessor system-licence :initarg :licence
+              :accessor system-license :initarg :license :initform nil)
+     (homepage :accessor system-homepage :initarg :homepage :initform nil)
+     (bug-tracker :accessor system-bug-tracker :initarg :bug-tracker :initform nil)
+     (mailto :accessor system-mailto :initarg :mailto :initform nil)
+     (long-name :accessor system-long-name :initarg :long-name :initform nil)
+     ;; Conventions for this slot aren't clear yet as of ASDF 2.27, but whenever they are, they will be enforced.
+     ;; I'm introducing the slot before the conventions are set for maximum compatibility.
+     (source-control :accessor system-source-control :initarg :source-control :initform nil)
+     (builtin-system-p :accessor builtin-system-p :initform nil :initarg :builtin-system-p)
+     (build-pathname
+      :initform nil :initarg :build-pathname :accessor component-build-pathname)
+     (entry-point
+      :initform nil :initarg :entry-point :accessor component-entry-point)
+     (source-file :initform nil :initarg :source-file :accessor system-source-file)
+     (defsystem-depends-on :reader system-defsystem-depends-on :initarg :defsystem-depends-on)))
+
+  (defun reset-system (system &rest keys &key &allow-other-keys)
+    (change-class (change-class system 'proto-system) 'system)
+    (apply 'reinitialize-instance system keys)))
+
+
+;;;; Pathnames
+
+(with-upgradability ()
+  (defmethod system-source-file ((system-name string))
+    (system-source-file (find-system system-name)))
+  (defmethod system-source-file ((system-name symbol))
+    (system-source-file (find-system system-name)))
+
+  (defun system-source-directory (system-designator)
+    "Return a pathname object corresponding to the directory
+in which the system specification (.asd file) is located."
+    (pathname-directory-pathname (system-source-file system-designator)))
+
+  (defun (system-relative-pathname) (system name &key type)
+    (subpathname (system-source-directory system) name :type type))
+
+  (defmethod component-pathname ((system system))
+    (let ((pathname (or (call-next-method) (system-source-directory system))))
+      (unless (and (slot-boundp system 'relative-pathname) ;; backward-compatibility with ASDF1-age
+                   (slot-value system 'relative-pathname)) ;; systems that directly access this slot.
+        (setf (slot-value system 'relative-pathname) pathname))
+      pathname))
+
+  (defmethod component-relative-pathname ((system system))
+    (parse-unix-namestring
+     (and (slot-boundp system 'relative-pathname)
+          (slot-value system 'relative-pathname))
+     :want-relative t
+     :type :directory
+     :ensure-absolute t
+     :defaults (system-source-directory system)))
+
+  (defmethod component-parent-pathname ((system system))
+    (system-source-directory system))
+
+  (defmethod component-build-pathname ((c component))
+    (declare (ignorable c))
+    nil))
 
 ;;;; -------------------------------------------------------------------------
-;;;; Classes, Conditions
-
-(define-condition system-definition-error (error) ()
-  ;; [this use of :report should be redundant, but unfortunately it's not.
-  ;; cmucl's lisp::output-instance prefers the kernel:slot-class-print-function
-  ;; over print-object; this is always conditions::%print-condition for
-  ;; condition objects, which in turn does inheritance of :report options at
-  ;; run-time.  fortunately, inheritance means we only need this kludge here in
-  ;; order to fix all conditions that build on it.  -- rgr, 28-Jul-02.]
-  #+cmu (:report print-object))
-
-(declaim (ftype (function (t) t)
-                format-arguments format-control
-                error-name error-pathname error-condition
-                duplicate-names-name
-                error-component error-operation
-                module-components module-components-by-name
-                circular-dependency-components)
-         (ftype (function (t t) t) (setf module-components-by-name)))
-
-
-(define-condition formatted-system-definition-error (system-definition-error)
-  ((format-control :initarg :format-control :reader format-control)
-   (format-arguments :initarg :format-arguments :reader format-arguments))
-  (:report (lambda (c s)
-             (apply #'format s (format-control c) (format-arguments c)))))
-
-(define-condition load-system-definition-error (system-definition-error)
-  ((name :initarg :name :reader error-name)
-   (pathname :initarg :pathname :reader error-pathname)
-   (condition :initarg :condition :reader error-condition))
-  (:report (lambda (c s)
-             (format s "~@<Error while trying to load definition for system ~A from pathname ~A: ~A~@:>"
-                     (error-name c) (error-pathname c) (error-condition c)))))
-
-(define-condition circular-dependency (system-definition-error)
-  ((components :initarg :components :reader circular-dependency-components))
-  (:report (lambda (c s)
-             (format s "~@<Circular dependency: ~S~@:>" (circular-dependency-components c)))))
-
-(define-condition duplicate-names (system-definition-error)
-  ((name :initarg :name :reader duplicate-names-name))
-  (:report (lambda (c s)
-             (format s "~@<Error while defining system: multiple components are given same name ~A~@:>"
-                     (duplicate-names-name c)))))
-
-(define-condition missing-component (system-definition-error)
-  ((requires :initform "(unnamed)" :reader missing-requires :initarg :requires)
-   (parent :initform nil :reader missing-parent :initarg :parent)))
-
-(define-condition missing-component-of-version (missing-component)
-  ((version :initform nil :reader missing-version :initarg :version)))
-
-(define-condition missing-dependency (missing-component)
-  ((required-by :initarg :required-by :reader missing-required-by)))
-
-(define-condition missing-dependency-of-version (missing-dependency
-                                                 missing-component-of-version)
-  ())
-
-(define-condition operation-error (error)
-  ((component :reader error-component :initarg :component)
-   (operation :reader error-operation :initarg :operation))
-  (:report (lambda (c s)
-             (format s "~@<erred while invoking ~A on ~A~@:>"
-                     (error-operation c) (error-component c)))))
-(define-condition compile-error (operation-error) ())
-(define-condition compile-failed (compile-error) ())
-(define-condition compile-warned (compile-error) ())
-
-(defclass component ()
-  ((name :accessor component-name :initarg :name :documentation
-         "Component name: designator for a string composed of portable pathname characters")
-   (version :accessor component-version :initarg :version)
-   ;; This one is used by POIU. Maybe in the future by ASDF instead of in-order-to?
-   ;; POIU is a parallel (multi-process build) extension of ASDF.  See
-   ;; http://www.cliki.net/poiu
-   (load-dependencies :accessor component-load-dependencies :initform nil)
-   ;; In the ASDF object model, dependencies exist between *actions*
-   ;; (an action is a pair of operation and component). They are represented
-   ;; alists of operations to dependencies (other actions) in each component.
-   ;; There are two kinds of dependencies, each stored in its own slot:
-   ;; in-order-to and do-first dependencies. These two kinds are related to
-   ;; the fact that some actions modify the filesystem,
-   ;; whereas other actions modify the current image, and
-   ;; this implies a difference in how to interpret timestamps.
-   ;; in-order-to dependencies will trigger re-performing the action
-   ;; when the timestamp of some dependency
-   ;; makes the timestamp of current action out-of-date;
-   ;; do-first dependencies do not trigger such re-performing.
-   ;; Therefore, a FASL must be recompiled if it is obsoleted
-   ;; by any of its FASL dependencies (in-order-to); but
-   ;; it needn't be recompiled just because one of these dependencies
-   ;; hasn't yet been loaded in the current image (do-first).
-   ;; The names are crap, but they have been the official API since Dan Barlow's ASDF 1.52!
-   (in-order-to :initform nil :initarg :in-order-to
-                :accessor component-in-order-to)
-   (do-first :initform nil :initarg :do-first
-             :accessor component-do-first)
-   ;; methods defined using the "inline" style inside a defsystem form:
-   ;; need to store them somewhere so we can delete them when the system
-   ;; is re-evaluated
-   (inline-methods :accessor component-inline-methods :initform nil)
-   (parent :initarg :parent :initform nil :reader component-parent)
-   ;; no direct accessor for pathname, we do this as a method to allow
-   ;; it to default in funky ways if not supplied
-   (relative-pathname :initarg :pathname)
-   (absolute-pathname)
-   (operation-times :initform (make-hash-table)
-                    :accessor component-operation-times)
-   ;; XXX we should provide some atomic interface for updating the
-   ;; component properties
-   (properties :accessor component-properties :initarg :properties
-               :initform nil)))
-
-(defun* component-find-path (component)
-  (reverse
-   (loop :for c = component :then (component-parent c)
-     :while c :collect (component-name c))))
-
-(defmethod print-object ((c component) stream)
-  (print-unreadable-object (c stream :type t :identity nil)
-    (format stream "~@<~{~S~^ ~}~@:>" (component-find-path c))))
-
-
-;;;; methods: conditions
-
-(defmethod print-object ((c missing-dependency) s)
-  (format s "~@<~A, required by ~A~@:>"
-          (call-next-method c nil) (missing-required-by c)))
-
-(defun* sysdef-error (format &rest arguments)
-  (error 'formatted-system-definition-error :format-control
-         format :format-arguments arguments))
-
-;;;; methods: components
-
-(defmethod print-object ((c missing-component) s)
-  (format s "~@<component ~S not found~@[ in ~A~]~@:>"
-          (missing-requires c)
-          (when (missing-parent c)
-            (coerce-name (missing-parent c)))))
-
-(defmethod print-object ((c missing-component-of-version) s)
-  (format s "~@<component ~S does not match version ~A~@[ in ~A~]~@:>"
-          (missing-requires c)
-          (missing-version c)
-          (when (missing-parent c)
-            (component-name (missing-parent c)))))
-
-(defmethod component-system ((component component))
-  (aif (component-parent component)
-       (component-system it)
-       component))
-
-(defvar *default-component-class* 'cl-source-file)
-
-(defun* compute-module-components-by-name (module)
-  (let ((hash (make-hash-table :test 'equal)))
-    (setf (module-components-by-name module) hash)
-    (loop :for c :in (module-components module)
-      :for name = (component-name c)
-      :for previous = (gethash name (module-components-by-name module))
-      :do
-      (when previous
-        (error 'duplicate-names :name name))
-      :do (setf (gethash name (module-components-by-name module)) c))
-    hash))
-
-(defclass module (component)
-  ((components
-    :initform nil
-    :initarg :components
-    :accessor module-components)
-   (components-by-name
-    :accessor module-components-by-name)
-   ;; What to do if we can't satisfy a dependency of one of this module's
-   ;; components.  This allows a limited form of conditional processing.
-   (if-component-dep-fails
-    :initform :fail
-    :initarg :if-component-dep-fails
-    :accessor module-if-component-dep-fails)
-   (default-component-class
-    :initform *default-component-class*
-    :initarg :default-component-class
-    :accessor module-default-component-class)))
-
-(defun* component-parent-pathname (component)
-  ;; No default anymore (in particular, no *default-pathname-defaults*).
-  ;; If you force component to have a NULL pathname, you better arrange
-  ;; for any of its children to explicitly provide a proper absolute pathname
-  ;; wherever a pathname is actually wanted.
-  (let ((parent (component-parent component)))
-    (when parent
-      (component-pathname parent))))
-
-(defmethod component-pathname ((component component))
-  (if (slot-boundp component 'absolute-pathname)
-      (slot-value component 'absolute-pathname)
-      (let ((pathname
-             (merge-pathnames*
-             (component-relative-pathname component)
-             (pathname-directory-pathname (component-parent-pathname component)))))
-        (unless (or (null pathname) (absolute-pathname-p pathname))
-          (error "Invalid relative pathname ~S for component ~S"
-                 pathname (component-find-path component)))
-        (setf (slot-value component 'absolute-pathname) pathname)
-        pathname)))
-
-(defmethod component-property ((c component) property)
-  (cdr (assoc property (slot-value c 'properties) :test #'equal)))
-
-(defmethod (setf component-property) (new-value (c component) property)
-  (let ((a (assoc property (slot-value c 'properties) :test #'equal)))
-    (if a
-        (setf (cdr a) new-value)
-        (setf (slot-value c 'properties)
-              (acons property new-value (slot-value c 'properties)))))
-  new-value)
-
-(defclass system (module)
-  ((description :accessor system-description :initarg :description)
-   (long-description
-    :accessor system-long-description :initarg :long-description)
-   (author :accessor system-author :initarg :author)
-   (maintainer :accessor system-maintainer :initarg :maintainer)
-   (licence :accessor system-licence :initarg :licence
-            :accessor system-license :initarg :license)
-   (source-file :reader system-source-file :initarg :source-file
-                :writer %set-system-source-file)
-   (defsystem-depends-on :reader system-defsystem-depends-on :initarg :defsystem-depends-on)))
-
-;;;; -------------------------------------------------------------------------
-;;;; version-satisfies
-
-(defmethod version-satisfies ((c component) version)
-  (unless (and version (slot-boundp c 'version))
-    (return-from version-satisfies t))
-  (version-satisfies (component-version c) version))
-
-(defmethod version-satisfies ((cver string) version)
-  (let ((x (mapcar #'parse-integer
-                   (split-string cver :separator ".")))
-        (y (mapcar #'parse-integer
-                   (split-string version :separator "."))))
-    (labels ((bigger (x y)
-               (cond ((not y) t)
-                     ((not x) nil)
-                     ((> (car x) (car y)) t)
-                     ((= (car x) (car y))
-                      (bigger (cdr x) (cdr y))))))
-      (and (= (car x) (car y))
-           (or (not (cdr y)) (bigger (cdr x) (cdr y)))))))
+;;;; Stamp cache
+
+(asdf/package:define-package :asdf/cache
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade)
+  (:export #:get-file-stamp #:compute-file-stamp #:register-file-stamp
+           #:consult-asdf-cache #:do-asdf-cache
+           #:call-with-asdf-cache #:with-asdf-cache #:*asdf-cache*))
+(in-package :asdf/cache)
+
+;;; This stamp cache is useful for:
+;; * consistency of stamps used within a single run
+;; * fewer accesses to the filesystem
+;; * the ability to test with fake timestamps, without touching files
+
+(with-upgradability ()
+  (defvar *asdf-cache* nil)
+
+  (defun set-asdf-cache-entry (key value-list)
+    (apply 'values
+           (if *asdf-cache*
+               (setf (gethash key *asdf-cache*) value-list)
+               value-list)))
+
+  (defun consult-asdf-cache (key &optional thunk)
+    (if *asdf-cache*
+        (multiple-value-bind (results foundp) (gethash key *asdf-cache*)
+          (if foundp
+              (apply 'values results)
+              (set-asdf-cache-entry key (multiple-value-list (call-function thunk)))))
+        (call-function thunk)))
+
+  (defmacro do-asdf-cache (key &body body)
+    `(consult-asdf-cache ,key #'(lambda () ,@body)))
+
+  (defun call-with-asdf-cache (thunk &key override)
+    (if (and *asdf-cache* (not override))
+        (funcall thunk)
+        (let ((*asdf-cache* (make-hash-table :test 'equal)))
+          (funcall thunk))))
+
+  (defmacro with-asdf-cache ((&key override) &body body)
+    `(call-with-asdf-cache #'(lambda () ,@body) :override ,override))
+
+  (defun compute-file-stamp (file)
+    (safe-file-write-date file))
+
+  (defun register-file-stamp (file &optional (stamp (compute-file-stamp file)))
+    (set-asdf-cache-entry `(get-file-stamp ,file) (list stamp)))
+
+  (defun get-file-stamp (file)
+    (do-asdf-cache `(get-file-stamp ,file) (compute-file-stamp file))))
+
 
 ;;;; -------------------------------------------------------------------------
 ;;;; Finding systems
 
-(defun* make-defined-systems-table ()
-  (make-hash-table :test 'equal))
-
-(defvar *defined-systems* (make-defined-systems-table)
-  "This is a hash table whose keys are strings, being the
+(asdf/package:define-package :asdf/find-system
+  (:recycle :asdf/find-system :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system :asdf/cache)
+  (:export
+   #:remove-entry-from-registry #:coerce-entry-to-directory
+   #:coerce-name #:primary-system-name #:coerce-filename
+   #:find-system #:locate-system #:load-asd #:with-system-definitions
+   #:system-registered-p #:register-system #:registered-systems #:clear-system #:map-systems
+   #:system-definition-error #:missing-component #:missing-requires #:missing-parent
+   #:formatted-system-definition-error #:format-control #:format-arguments #:sysdef-error
+   #:load-system-definition-error #:error-name #:error-pathname #:error-condition
+   #:*system-definition-search-functions* #:search-for-system-definition
+   #:*central-registry* #:probe-asd #:sysdef-central-registry-search
+   #:find-system-if-being-defined #:*systems-being-defined*
+   #:contrib-sysdef-search #:sysdef-find-asdf ;; backward compatibility symbols, functions removed
+   #:sysdef-preloaded-system-search #:register-preloaded-system #:*preloaded-systems*
+   #:clear-defined-systems #:*defined-systems*
+   ;; defined in source-registry, but specially mentioned here:
+   #:initialize-source-registry #:sysdef-source-registry-search))
+(in-package :asdf/find-system)
+
+(with-upgradability ()
+  (declaim (ftype (function (&optional t) t) initialize-source-registry)) ; forward reference
+
+  (define-condition system-definition-error (error) ()
+    ;; [this use of :report should be redundant, but unfortunately it's not.
+    ;; cmucl's lisp::output-instance prefers the kernel:slot-class-print-function
+    ;; over print-object; this is always conditions::%print-condition for
+    ;; condition objects, which in turn does inheritance of :report options at
+    ;; run-time.  fortunately, inheritance means we only need this kludge here in
+    ;; order to fix all conditions that build on it.  -- rgr, 28-Jul-02.]
+    #+cmu (:report print-object))
+
+  (define-condition missing-component (system-definition-error)
+    ((requires :initform "(unnamed)" :reader missing-requires :initarg :requires)
+     (parent :initform nil :reader missing-parent :initarg :parent)))
+
+  (define-condition formatted-system-definition-error (system-definition-error)
+    ((format-control :initarg :format-control :reader format-control)
+     (format-arguments :initarg :format-arguments :reader format-arguments))
+    (:report (lambda (c s)
+               (apply 'format s (format-control c) (format-arguments c)))))
+
+  (define-condition load-system-definition-error (system-definition-error)
+    ((name :initarg :name :reader error-name)
+     (pathname :initarg :pathname :reader error-pathname)
+     (condition :initarg :condition :reader error-condition))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<Error while trying to load definition for system ~A from pathname ~A: ~3i~_~A~@:>")
+                       (error-name c) (error-pathname c) (error-condition c)))))
+
+  (defun sysdef-error (format &rest arguments)
+    (error 'formatted-system-definition-error :format-control
+           format :format-arguments arguments))
+
+  (defun coerce-name (name)
+    (typecase name
+      (component (component-name name))
+      (symbol (string-downcase (symbol-name name)))
+      (string name)
+      (t (sysdef-error (compatfmt "~@<Invalid component designator: ~3i~_~A~@:>") name))))
+
+  (defun primary-system-name (name)
+    ;; When a system name has slashes, the file with defsystem is named by
+    ;; the first of the slash-separated components.
+    (first (split-string (coerce-name name) :separator "/")))
+
+  (defun coerce-filename (name)
+    (frob-substrings (coerce-name name) '("/" ":" "\\") "--"))
+
+  (defvar *defined-systems* (make-hash-table :test 'equal)
+    "This is a hash table whose keys are strings, being the
 names of the systems, and whose values are pairs, the first
 element of which is a universal-time indicating when the
 system definition was last updated, and the second element
 of which is a system object.")
 
-(defun* coerce-name (name)
-  (typecase name
-    (component (component-name name))
-    (symbol (string-downcase (symbol-name name)))
-    (string name)
-    (t (sysdef-error "~@<invalid component designator ~A~@:>" name))))
-
-(defun* system-registered-p (name)
-  (gethash (coerce-name name) *defined-systems*))
-
-(defun* clear-system (name)
-  "Clear the entry for a system in the database of systems previously loaded.
+  (defun system-registered-p (name)
+    (gethash (coerce-name name) *defined-systems*))
+
+  (defun registered-systems ()
+    (loop :for registered :being :the :hash-values :of *defined-systems*
+          :collect (coerce-name (cdr registered))))
+
+  (defun register-system (system)
+    (check-type system system)
+    (let ((name (component-name system)))
+      (check-type name string)
+      (asdf-message (compatfmt "~&~@<; ~@;Registering ~3i~_~A~@:>~%") system)
+      (unless (eq system (cdr (gethash name *defined-systems*)))
+        (setf (gethash name *defined-systems*)
+              (cons (if-let (file (ignore-errors (system-source-file system)))
+                      (get-file-stamp file))
+                    system)))))
+
+  (defun clear-defined-systems ()
+    ;; Invalidate all systems but ASDF itself, if registered.
+    (let ((asdf (cdr (system-registered-p :asdf))))
+      (setf *defined-systems* (make-hash-table :test 'equal))
+      (when asdf
+        (setf (component-version asdf) *asdf-version*)
+        (setf (builtin-system-p asdf) t)
+        (register-system asdf)))
+    (values))
+
+  (register-hook-function '*post-upgrade-cleanup-hook* 'clear-defined-systems nil)
+
+  (defun clear-system (name)
+    "Clear the entry for a system in the database of systems previously loaded.
 Note that this does NOT in any way cause the code of the system to be unloaded."
-  ;; There is no "unload" operation in Common Lisp, and a general such operation
-  ;; cannot be portably written, considering how much CL relies on side-effects
-  ;; of global data structures.
-  ;; Note that this does a setf gethash instead of a remhash
-  ;; this way there remains a hint in the *defined-systems* table
-  ;; that the system was loaded at some point.
-  (setf (gethash (coerce-name name) *defined-systems*) nil))
-
-(defun* map-systems (fn)
-  "Apply FN to each defined system.
+    ;; There is no "unload" operation in Common Lisp, and
+    ;; a general such operation cannot be portably written,
+    ;; considering how much CL relies on side-effects to global data structures.
+    (remhash (coerce-name name) *defined-systems*))
+
+  (defun map-systems (fn)
+    "Apply FN to each defined system.
 
 FN should be a function of one argument. It will be
 called with an object of type asdf:system."
-  (maphash (lambda (_ datum)
-             (declare (ignore _))
-             (destructuring-bind (_ . def) datum
-               (declare (ignore _))
-               (funcall fn def)))
-           *defined-systems*))
+    (loop :for registered :being :the :hash-values :of *defined-systems*
+          :do (funcall fn (cdr registered)))))
 
 ;;; for the sake of keeping things reasonably neat, we adopt a
 ;;; convention that functions in this list are prefixed SYSDEF-
-
-(defparameter *system-definition-search-functions*
-  '(sysdef-central-registry-search sysdef-source-registry-search sysdef-find-asdf))
-
-(defun* system-definition-pathname (system)
-  (let ((system-name (coerce-name system)))
-    (or
-     (some (lambda (x) (funcall x system-name))
-           *system-definition-search-functions*)
-     (let ((system-pair (system-registered-p system-name)))
-       (and system-pair
-            (system-source-file (cdr system-pair)))))))
-
-(defvar *central-registry* nil
-"A list of 'system directory designators' ASDF uses to find systems.
+(with-upgradability ()
+  (defvar *system-definition-search-functions* '())
+
+  (defun cleanup-system-definition-search-functions ()
+    (setf *system-definition-search-functions*
+          (append
+           ;; Remove known-incompatible sysdef functions from old versions of asdf.
+           (remove-if #'(lambda (x) (member x '(contrib-sysdef-search sysdef-find-asdf)))
+                      *system-definition-search-functions*)
+           ;; Tuck our defaults at the end of the list if they were absent.
+           ;; This is imperfect, in case they were removed on purpose,
+           ;; but then it will be the responsibility of whoever does that
+           ;; to upgrade asdf before he does such a thing rather than after.
+           (remove-if #'(lambda (x) (member x *system-definition-search-functions*))
+                      '(sysdef-central-registry-search
+                        sysdef-source-registry-search
+                        sysdef-preloaded-system-search)))))
+  (cleanup-system-definition-search-functions)
+
+  (defun search-for-system-definition (system)
+    (some (let ((name (coerce-name system))) #'(lambda (x) (funcall x name)))
+          (cons 'find-system-if-being-defined
+                *system-definition-search-functions*)))
+
+  (defvar *central-registry* nil
+    "A list of 'system directory designators' ASDF uses to find systems.
 
 A 'system directory designator' is a pathname or an expression
 which evaluates to a pathname. For example:
@@ -1195,2443 +6069,3584 @@
                 #p\"/home/me/cl/systems/\"
                 #p\"/usr/share/common-lisp/systems/\"))
 
-This is for backward compatibilily.
+This is for backward compatibility.
 Going forward, we recommend new users should be using the source-registry.
 ")
 
-(defun* probe-asd (name defaults)
-  (block nil
-    (when (directory-pathname-p defaults)
-      (let ((file
-             (make-pathname
-              :defaults defaults :version :newest :case :local
-              :name name
-              :type "asd")))
-        (when (probe-file file)
-          (return file)))
-      #+(and (or win32 windows mswindows mingw32) (not cygwin) (not clisp))
-      (let ((shortcut
-             (make-pathname
-              :defaults defaults :version :newest :case :local
-              :name (concatenate 'string name ".asd")
-              :type "lnk")))
-        (when (probe-file shortcut)
-          (let ((target (parse-windows-shortcut shortcut)))
-            (when target
-              (return (pathname target)))))))))
-
-(defun* sysdef-central-registry-search (system)
-  (let ((name (coerce-name system))
-        (to-remove nil)
-        (to-replace nil))
+  (defun probe-asd (name defaults &key truename)
     (block nil
-      (unwind-protect
-           (dolist (dir *central-registry*)
-             (let ((defaults (eval dir)))
-               (when defaults
-                 (cond ((directory-pathname-p defaults)
-                        (let ((file (probe-asd name defaults)))
-                          (when file
-                            (return file))))
-                       (t
-                        (restart-case
-                            (let* ((*print-circle* nil)
-                                   (message
-                                    (format nil
-                                            "~@<While searching for system ~S: ~S evaluated to ~S which is not a directory.~@:>"
-                                            system dir defaults)))
-                              (error message))
-                          (remove-entry-from-registry ()
-                            :report "Remove entry from *central-registry* and continue"
-                            (push dir to-remove))
-                          (coerce-entry-to-directory ()
-                            :report (lambda (s)
-                                      (format s "Coerce entry to ~a, replace ~a and continue."
-                                              (ensure-directory-pathname defaults) dir))
-                            (push (cons dir (ensure-directory-pathname defaults)) to-replace))))))))
-        ;; cleanup
-        (dolist (dir to-remove)
-          (setf *central-registry* (remove dir *central-registry*)))
-        (dolist (pair to-replace)
-          (let* ((current (car pair))
-                 (new (cdr pair))
-                 (position (position current *central-registry*)))
-            (setf *central-registry*
-                  (append (subseq *central-registry* 0 position)
-                          (list new)
-                          (subseq *central-registry* (1+ position))))))))))
-
-(defun* make-temporary-package ()
-  (flet ((try (counter)
-           (ignore-errors
-             (make-package (format nil "~A~D" :asdf counter)
-                           :use '(:cl :asdf)))))
-    (do* ((counter 0 (+ counter 1))
-          (package (try counter) (try counter)))
-         (package package))))
-
-(defun* safe-file-write-date (pathname)
-  ;; If FILE-WRITE-DATE returns NIL, it's possible that
-  ;; the user or some other agent has deleted an input file.
-  ;; Also, generated files will not exist at the time planning is done
-  ;; and calls operation-done-p which calls safe-file-write-date.
-  ;; So it is very possible that we can't get a valid file-write-date,
-  ;; and we can survive and we will continue the planning
-  ;; as if the file were very old.
-  ;; (or should we treat the case in a different, special way?)
-  (or (and pathname (probe-file pathname) (file-write-date pathname))
-      (progn
-        (when (and pathname *asdf-verbose*)
-          (warn "Missing FILE-WRITE-DATE for ~S: treating it as zero."
-                pathname))
-        0)))
-
-(defmethod find-system (name &optional (error-p t))
-  (find-system (coerce-name name) error-p))
-
-(defmethod find-system ((name string) &optional (error-p t))
-  (catch 'find-system
-    (let* ((in-memory (system-registered-p name))
-           (on-disk (system-definition-pathname name)))
-      (when (and on-disk
-                 (or (not in-memory)
-                     (< (car in-memory) (safe-file-write-date on-disk))))
-        (let ((package (make-temporary-package)))
-          (unwind-protect
-               (handler-bind
-                   ((error (lambda (condition)
-                             (error 'load-system-definition-error
-                                    :name name :pathname on-disk
-                                    :condition condition))))
-                 (let ((*package* package))
-                   (asdf-message
-                    "~&~@<; ~@;Loading system definition from ~A into ~A~@:>~%"
-                    on-disk *package*)
-                   (load on-disk)))
-            (delete-package package))))
-      (let ((in-memory (system-registered-p name)))
+      (when (directory-pathname-p defaults)
+        (if-let (file (probe-file*
+                       (ensure-absolute-pathname
+                        (parse-unix-namestring name :type "asd")
+                        #'(lambda () (ensure-absolute-pathname defaults 'get-pathname-defaults nil))
+                        nil)
+                       :truename truename))
+          (return file))
+        #-(or clisp genera) ; clisp doesn't need it, plain genera doesn't have read-sequence(!)
+        (when (os-windows-p)
+          (let ((shortcut
+                  (make-pathname
+                   :defaults defaults :case :local
+                   :name (strcat name ".asd")
+                   :type "lnk")))
+            (when (probe-file* shortcut)
+              (let ((target (parse-windows-shortcut shortcut)))
+                (when target
+                  (return (pathname target))))))))))
+
+  (defun sysdef-central-registry-search (system)
+    (let ((name (primary-system-name system))
+          (to-remove nil)
+          (to-replace nil))
+      (block nil
+        (unwind-protect
+             (dolist (dir *central-registry*)
+               (let ((defaults (eval dir))
+                     directorized)
+                 (when defaults
+                   (cond ((directory-pathname-p defaults)
+                          (let* ((file (probe-asd name defaults :truename *resolve-symlinks*)))
+                            (when file
+                              (return file))))
+                         (t
+                          (restart-case
+                              (let* ((*print-circle* nil)
+                                     (message
+                                       (format nil
+                                               (compatfmt "~@<While searching for system ~S: ~3i~_~S evaluated to ~S which is not an absolute directory.~@:>")
+                                               system dir defaults)))
+                                (error message))
+                            (remove-entry-from-registry ()
+                              :report "Remove entry from *central-registry* and continue"
+                              (push dir to-remove))
+                            (coerce-entry-to-directory ()
+                              :test (lambda (c) (declare (ignore c))
+                                      (and (not (directory-pathname-p defaults))
+                                           (directory-pathname-p
+                                            (setf directorized
+                                                  (ensure-directory-pathname defaults)))))
+                              :report (lambda (s)
+                                        (format s (compatfmt "~@<Coerce entry to ~a, replace ~a and continue.~@:>")
+                                                directorized dir))
+                              (push (cons dir directorized) to-replace))))))))
+          ;; cleanup
+          (dolist (dir to-remove)
+            (setf *central-registry* (remove dir *central-registry*)))
+          (dolist (pair to-replace)
+            (let* ((current (car pair))
+                   (new (cdr pair))
+                   (position (position current *central-registry*)))
+              (setf *central-registry*
+                    (append (subseq *central-registry* 0 position)
+                            (list new)
+                            (subseq *central-registry* (1+ position))))))))))
+
+  (defvar *preloaded-systems* (make-hash-table :test 'equal))
+
+  (defun make-preloaded-system (name keys)
+    (apply 'make-instance (getf keys :class 'system)
+           :name name :source-file (getf keys :source-file)
+           (remove-plist-keys '(:class :name :source-file) keys)))
+
+  (defun sysdef-preloaded-system-search (requested)
+    (let ((name (coerce-name requested)))
+      (multiple-value-bind (keys foundp) (gethash name *preloaded-systems*)
+        (when foundp
+          (make-preloaded-system name keys)))))
+
+  (defun register-preloaded-system (system-name &rest keys)
+    (setf (gethash (coerce-name system-name) *preloaded-systems*) keys))
+
+  (register-preloaded-system "asdf" :version *asdf-version*)
+  (register-preloaded-system "asdf-driver" :version *asdf-version*)
+
+  (defmethod find-system ((name null) &optional (error-p t))
+    (declare (ignorable name))
+    (when error-p
+      (sysdef-error (compatfmt "~@<NIL is not a valid system name~@:>"))))
+
+  (defmethod find-system (name &optional (error-p t))
+    (find-system (coerce-name name) error-p))
+
+  (defvar *systems-being-defined* nil
+    "A hash-table of systems currently being defined keyed by name, or NIL")
+
+  (defun find-system-if-being-defined (name)
+    (when *systems-being-defined*
+      (gethash (coerce-name name) *systems-being-defined*)))
+
+  (defun call-with-system-definitions (thunk)
+    (if *systems-being-defined*
+        (call-with-asdf-cache thunk)
+        (let ((*systems-being-defined* (make-hash-table :test 'equal)))
+          (call-with-asdf-cache thunk))))
+
+  (defun clear-systems-being-defined ()
+    (when *systems-being-defined*
+      (clrhash *systems-being-defined*)))
+
+  (register-hook-function '*post-upgrade-cleanup-hook* 'clear-systems-being-defined)
+
+  (defmacro with-system-definitions ((&optional) &body body)
+    `(call-with-system-definitions #'(lambda () ,@body)))
+
+  (defun load-asd (pathname &key name (external-format (encoding-external-format (detect-encoding pathname))) &aux (readtable *readtable*) (print-pprint-dispatch *print-pprint-dispatch*))
+    ;; Tries to load system definition with canonical NAME from PATHNAME.
+    (with-system-definitions ()
+      (with-standard-io-syntax
+        (let ((*package* (find-package :asdf-user))
+              ;; Note that our backward-compatible *readtable* is
+              ;; a global readtable that gets globally side-effected. Ouch.
+              ;; Same for the *print-pprint-dispatch* table.
+              ;; We should do something about that for ASDF3 if possible, or else ASDF4.
+              (*readtable* readtable)
+              (*print-pprint-dispatch* print-pprint-dispatch)
+              (*print-readably* nil)
+              (*default-pathname-defaults*
+                ;; resolve logical-pathnames so they won't wreak havoc in parsing namestrings.
+                (pathname-directory-pathname (translate-logical-pathname pathname))))
+          (handler-bind
+              ((error #'(lambda (condition)
+                          (error 'load-system-definition-error
+                                 :name name :pathname pathname
+                                 :condition condition))))
+            (asdf-message (compatfmt "~&~@<; ~@;Loading system definition~@[ for ~A~] from ~A~@:>~%")
+                          name pathname)
+            (with-muffled-loader-conditions ()
+              (load* pathname :external-format external-format)))))))
+
+  (defvar *old-asdf-systems* (make-hash-table :test 'equal))
+
+  (defun check-not-old-asdf-system (name pathname)
+    (or (not (equal name "asdf"))
+        (null pathname)
+        (let* ((version-pathname (subpathname pathname "version.lisp-expr"))
+               (version (and (probe-file* version-pathname :truename nil)
+                             (read-file-form version-pathname)))
+               (old-version (asdf-version)))
+          (or (version<= old-version version)
+              (let ((old-pathname
+                      (if-let (pair (system-registered-p "asdf"))
+                        (system-source-file (cdr pair))))
+                    (key (list pathname old-version)))
+                (unless (gethash key *old-asdf-systems*)
+                  (setf (gethash key *old-asdf-systems*) t)
+                  (warn "~@<~
+        You are using ASDF version ~A ~:[(probably from (require \"asdf\") ~
+        or loaded by quicklisp)~;from ~:*~S~] and have an older version of ASDF ~
+        ~:[(and older than 2.27 at that)~;~:*~A~] registered at ~S. ~
+        Having an ASDF installed and registered is the normal way of configuring ASDF to upgrade itself, ~
+        and having an old version registered is a configuration error. ~
+        ASDF will ignore this configured system rather than downgrade itself. ~
+        In the future, you may want to either: ~
+        (a) upgrade this configured ASDF to a newer version, ~
+        (b) install a newer ASDF and register it in front of the former in your configuration, or ~
+        (c) uninstall or unregister this and any other old version of ASDF from your configuration. ~
+        Note that the older ASDF might be registered implicitly through configuration inherited ~
+        from your system installation, in which case you might have to specify ~
+        :ignore-inherited-configuration in your in your ~~/.config/common-lisp/source-registry.conf ~
+        or other source-registry configuration file, environment variable or lisp parameter. ~
+        Indeed, a likely offender is an obsolete version of the cl-asdf debian or ubuntu package, ~
+        that you might want to upgrade (if a recent enough version is available) ~
+        or else remove altogether (since most implementations ship with a recent asdf); ~
+        if you lack the system administration rights to upgrade or remove this package, ~
+        then you might indeed want to either install and register a more recent version, ~
+        or use :ignore-inherited-configuration to avoid registering the old one. ~
+        Please consult ASDF documentation and/or experts.~@:>~%"
+                    old-version old-pathname version pathname)))))))
+
+  (defun locate-system (name)
+    "Given a system NAME designator, try to locate where to load the system from.
+Returns five values: FOUNDP FOUND-SYSTEM PATHNAME PREVIOUS PREVIOUS-TIME
+FOUNDP is true when a system was found,
+either a new unregistered one or a previously registered one.
+FOUND-SYSTEM when not null is a SYSTEM object that may be REGISTER-SYSTEM'ed as is
+PATHNAME when not null is a path from where to load the system,
+either associated with FOUND-SYSTEM, or with the PREVIOUS system.
+PREVIOUS when not null is a previously loaded SYSTEM object of same name.
+PREVIOUS-TIME when not null is the time at which the PREVIOUS system was loaded."
+    (let* ((name (coerce-name name))
+           (in-memory (system-registered-p name)) ; load from disk if absent or newer on disk
+           (previous (cdr in-memory))
+           (previous (and (typep previous 'system) previous))
+           (previous-time (car in-memory))
+           (found (search-for-system-definition name))
+           (found-system (and (typep found 'system) found))
+           (pathname (ensure-pathname
+                      (or (and (typep found '(or pathname string)) (pathname found))
+                          (and found-system (system-source-file found-system))
+                          (and previous (system-source-file previous)))
+                     :want-absolute t :resolve-symlinks *resolve-symlinks*))
+           (foundp (and (or found-system pathname previous) t)))
+      (check-type found (or null pathname system))
+      (unless (check-not-old-asdf-system name pathname)
         (cond
-          (in-memory
-           (when on-disk
-             (setf (car in-memory) (safe-file-write-date on-disk)))
-           (cdr in-memory))
-          (error-p
-           (error 'missing-component :requires name)))))))
-
-(defun* register-system (name system)
-  (asdf-message "~&~@<; ~@;Registering ~A as ~A~@:>~%" system name)
-  (setf (gethash (coerce-name name) *defined-systems*)
-        (cons (get-universal-time) system)))
-
-(defun* find-system-fallback (requested fallback &rest keys &key source-file &allow-other-keys)
-  (setf fallback (coerce-name fallback)
-        source-file (or source-file
-                        (if *resolve-symlinks*
-                            (or *compile-file-truename* *load-truename*)
-                            (or *compile-file-pathname* *load-pathname*)))
-        requested (coerce-name requested))
-  (when (equal requested fallback)
-    (let* ((registered (cdr (gethash fallback *defined-systems*)))
-           (system (or registered
-                       (apply 'make-instance 'system
-                              :name fallback :source-file source-file keys))))
-      (unless registered
-        (register-system fallback system))
-      (throw 'find-system system))))
-
-(defun* sysdef-find-asdf (name)
-  (find-system-fallback name "asdf")) ;; :version *asdf-version* wouldn't be updated when ASDF is updated.
-
+          (previous (setf found nil pathname nil))
+          (t
+           (setf found (sysdef-preloaded-system-search "asdf"))
+           (assert (typep found 'system))
+           (setf found-system found pathname nil))))
+      (values foundp found-system pathname previous previous-time)))
+
+  (defmethod find-system ((name string) &optional (error-p t))
+    (with-system-definitions ()
+      (loop
+        (restart-case
+            (multiple-value-bind (foundp found-system pathname previous previous-time)
+                (locate-system name)
+              (assert (eq foundp (and (or found-system pathname previous) t)))
+              (let ((previous-pathname (and previous (system-source-file previous)))
+                    (system (or previous found-system)))
+                (when (and found-system (not previous))
+                  (register-system found-system))
+                (when (and system pathname)
+                  (setf (system-source-file system) pathname))
+                (when (and pathname
+                           (let ((stamp (get-file-stamp pathname)))
+                             (and stamp
+                                  (not (and previous
+                                            (or (pathname-equal pathname previous-pathname)
+                                                (and pathname previous-pathname
+                                                     (pathname-equal
+                                                      (translate-logical-pathname pathname)
+                                                      (translate-logical-pathname previous-pathname))))
+                                            (stamp<= stamp previous-time))))))
+                  ;; only load when it's a pathname that is different or has newer content, and not an old asdf
+                  (load-asd pathname :name name)))
+              (let ((in-memory (system-registered-p name))) ; try again after loading from disk if needed
+                (return
+                  (cond
+                    (in-memory
+                     (when pathname
+                       (setf (car in-memory) (get-file-stamp pathname)))
+                     (cdr in-memory))
+                    (error-p
+                     (error 'missing-component :requires name))))))
+          (reinitialize-source-registry-and-retry ()
+            :report (lambda (s)
+                      (format s (compatfmt "~@<Retry finding system ~A after reinitializing the source-registry.~@:>") name))
+            (initialize-source-registry)))))))
 
 ;;;; -------------------------------------------------------------------------
 ;;;; Finding components
 
-(defmethod find-component ((base string) path)
-  (let ((s (find-system base nil)))
-    (and s (find-component s path))))
-
-(defmethod find-component ((base symbol) path)
-  (cond
-    (base (find-component (coerce-name base) path))
-    (path (find-component path nil))
-    (t    nil)))
-
-(defmethod find-component ((base cons) path)
-  (find-component (car base) (cons (cdr base) path)))
-
-(defmethod find-component ((module module) (name string))
-  (unless (slot-boundp module 'components-by-name) ;; SBCL may miss the u-i-f-r-c method!!!
-    (compute-module-components-by-name module))
-  (values (gethash name (module-components-by-name module))))
-
-(defmethod find-component ((component component) (name symbol))
-  (if name
-      (find-component component (coerce-name name))
-      component))
-
-(defmethod find-component ((module module) (name cons))
-  (find-component (find-component module (car name)) (cdr name)))
-
-
-;;; component subclasses
-
-(defclass source-file (component)
-  ((type :accessor source-file-explicit-type :initarg :type :initform nil)))
-
-(defclass cl-source-file (source-file)
-  ((type :initform "lisp")))
-(defclass c-source-file (source-file)
-  ((type :initform "c")))
-(defclass java-source-file (source-file)
-  ((type :initform "java")))
-(defclass static-file (source-file) ())
-(defclass doc-file (static-file) ())
-(defclass html-file (doc-file)
-  ((type :initform "html")))
-
-(defmethod source-file-type ((component module) (s module))
-  (declare (ignorable component s))
-  :directory)
-(defmethod source-file-type ((component source-file) (s module))
-  (declare (ignorable s))
-  (source-file-explicit-type component))
-
-(defun* merge-component-name-type (name &key type defaults)
-  ;; The defaults are required notably because they provide the default host
-  ;; to the below make-pathname, which may crucially matter to people using
-  ;; merge-pathnames with non-default hosts,  e.g. for logical-pathnames.
-  ;; NOTE that the host and device slots will be taken from the defaults,
-  ;; but that should only matter if you either (a) use absolute pathnames, or
-  ;; (b) later merge relative pathnames with CL:MERGE-PATHNAMES instead of
-  ;; ASDF:MERGE-PATHNAMES*
-  (etypecase name
-    (pathname
-     name)
-    (symbol
-     (merge-component-name-type (string-downcase name) :type type :defaults defaults))
-    (string
-     (multiple-value-bind (relative path filename)
-         (component-name-to-pathname-components name :force-directory (eq type :directory)
-                                                :force-relative t)
-       (multiple-value-bind (name type)
-           (cond
-             ((or (eq type :directory) (null filename))
-              (values nil nil))
-             (type
-              (values filename type))
-             (t
-              (split-name-type filename)))
-         (let* ((defaults (pathname (or defaults *default-pathname-defaults*)))
-                (host (pathname-host defaults))
-                (device (pathname-device defaults)))
-           (make-pathname :directory `(,relative ,@path)
-                          :name name :type type
-                          :host host :device device)))))))
-
-(defmethod component-relative-pathname ((component component))
-  (merge-component-name-type
-   (or (slot-value component 'relative-pathname)
-       (component-name component))
-   :type (source-file-type component (component-system component))
-   :defaults (component-parent-pathname component)))
+(asdf/package:define-package :asdf/find-component
+  (:recycle :asdf/find-component :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system :asdf/find-system)
+  (:export
+   #:find-component
+   #:resolve-dependency-name #:resolve-dependency-spec
+   #:resolve-dependency-combination
+   ;; Conditions
+   #:missing-component #:missing-component-of-version #:retry
+   #:missing-dependency #:missing-dependency-of-version
+   #:missing-requires #:missing-parent
+   #:missing-required-by #:missing-version))
+(in-package :asdf/find-component)
+
+;;;; Missing component conditions
+
+(with-upgradability ()
+  (define-condition missing-component-of-version (missing-component)
+    ((version :initform nil :reader missing-version :initarg :version)))
+
+  (define-condition missing-dependency (missing-component)
+    ((required-by :initarg :required-by :reader missing-required-by)))
+
+  (defmethod print-object ((c missing-dependency) s)
+    (format s (compatfmt "~@<~A, required by ~A~@:>")
+            (call-next-method c nil) (missing-required-by c)))
+
+  (define-condition missing-dependency-of-version (missing-dependency
+                                                   missing-component-of-version)
+    ())
+
+  (defmethod print-object ((c missing-component) s)
+    (format s (compatfmt "~@<Component ~S not found~@[ in ~A~]~@:>")
+            (missing-requires c)
+            (when (missing-parent c)
+              (coerce-name (missing-parent c)))))
+
+  (defmethod print-object ((c missing-component-of-version) s)
+    (format s (compatfmt "~@<Component ~S does not match version ~A~@[ in ~A~]~@:>")
+            (missing-requires c)
+            (missing-version c)
+            (when (missing-parent c)
+              (coerce-name (missing-parent c))))))
+
+
+;;;; Finding components
+
+(with-upgradability ()
+  (defgeneric* (find-component) (base path)
+    (:documentation "Find a component by resolving the PATH starting from BASE parent"))
+  (defgeneric resolve-dependency-combination (component combinator arguments))
+
+  (defmethod find-component ((base string) path)
+    (let ((s (find-system base nil)))
+      (and s (find-component s path))))
+
+  (defmethod find-component ((base symbol) path)
+    (cond
+      (base (find-component (coerce-name base) path))
+      (path (find-component path nil))
+      (t    nil)))
+
+  (defmethod find-component ((base cons) path)
+    (find-component (car base) (cons (cdr base) path)))
+
+  (defmethod find-component ((parent parent-component) (name string))
+    (compute-children-by-name parent :only-if-needed-p t) ;; SBCL may miss the u-i-f-r-c method!!!
+    (values (gethash name (component-children-by-name parent))))
+
+  (defmethod find-component (base (name symbol))
+    (if name
+        (find-component base (coerce-name name))
+        base))
+
+  (defmethod find-component ((c component) (name cons))
+    (find-component (find-component c (car name)) (cdr name)))
+
+  (defmethod find-component (base (actual component))
+    (declare (ignorable base))
+    actual)
+
+  (defun resolve-dependency-name (component name &optional version)
+    (loop
+      (restart-case
+          (return
+            (let ((comp (find-component (component-parent component) name)))
+              (unless comp
+                (error 'missing-dependency
+                       :required-by component
+                       :requires name))
+              (when version
+                (unless (version-satisfies comp version)
+                  (error 'missing-dependency-of-version
+                         :required-by component
+                         :version version
+                         :requires name)))
+              comp))
+        (retry ()
+          :report (lambda (s)
+                    (format s (compatfmt "~@<Retry loading ~3i~_~A.~@:>") name))
+          :test
+          (lambda (c)
+            (or (null c)
+                (and (typep c 'missing-dependency)
+                     (eq (missing-required-by c) component)
+                     (equal (missing-requires c) name))))))))
+
+  (defun resolve-dependency-spec (component dep-spec)
+    (let ((component (find-component () component)))
+      (if (atom dep-spec)
+          (resolve-dependency-name component dep-spec)
+          (resolve-dependency-combination component (car dep-spec) (cdr dep-spec)))))
+
+  (defmethod resolve-dependency-combination (component combinator arguments)
+    (error (compatfmt "~@<Bad dependency ~S for ~S~@:>")
+           (cons combinator arguments) component))
+
+  (defmethod resolve-dependency-combination (component (combinator (eql :feature)) arguments)
+    (declare (ignorable combinator))
+    (when (featurep (first arguments))
+      (resolve-dependency-spec component (second arguments))))
+
+  (defmethod resolve-dependency-combination (component (combinator (eql :version)) arguments)
+    (declare (ignorable combinator)) ;; See https://bugs.launchpad.net/asdf/+bug/527788
+    (resolve-dependency-name component (first arguments) (second arguments))))
 
 ;;;; -------------------------------------------------------------------------
 ;;;; Operations
 
-;;; one of these is instantiated whenever #'operate is called
-
-(defclass operation ()
-  (
-   ;; as of danb's 2003-03-16 commit e0d02781, :force can be:
-   ;; T to force the inside of existing system,
-   ;;   but not recurse to other systems we depend on.
-   ;; :ALL (or any other atom) to force all systems
-   ;;   including other systems we depend on.
-   ;; (SYSTEM1 SYSTEM2 ... SYSTEMN)
-   ;;   to force systems named in a given list
-   ;; However, but this feature never worked before ASDF 1.700 and is currently cerror'ed out.
-   (forced :initform nil :initarg :force :accessor operation-forced)
-   (original-initargs :initform nil :initarg :original-initargs
-                      :accessor operation-original-initargs)
-   (visited-nodes :initform (make-hash-table :test 'equal) :accessor operation-visited-nodes)
-   (visiting-nodes :initform (make-hash-table :test 'equal) :accessor operation-visiting-nodes)
-   (parent :initform nil :initarg :parent :accessor operation-parent)))
-
-(defmethod print-object ((o operation) stream)
-  (print-unreadable-object (o stream :type t :identity t)
-    (ignore-errors
-      (prin1 (operation-original-initargs o) stream))))
-
-(defmethod shared-initialize :after ((operation operation) slot-names
-                                     &key force
-                                     &allow-other-keys)
-  (declare (ignorable operation slot-names force))
-  ;; empty method to disable initarg validity checking
-  (values))
-
-(defun* node-for (o c)
-  (cons (class-name (class-of o)) c))
-
-(defmethod operation-ancestor ((operation operation))
-  (aif (operation-parent operation)
-       (operation-ancestor it)
-       operation))
-
-
-(defun* make-sub-operation (c o dep-c dep-o)
-  "C is a component, O is an operation, DEP-C is another
-component, and DEP-O, confusingly enough, is an operation
-class specifier, not an operation."
-  (let* ((args (copy-list (operation-original-initargs o)))
-         (force-p (getf args :force)))
-    ;; note explicit comparison with T: any other non-NIL force value
-    ;; (e.g. :recursive) will pass through
-    (cond ((and (null (component-parent c))
-                (null (component-parent dep-c))
-                (not (eql c dep-c)))
-           (when (eql force-p t)
-             (setf (getf args :force) nil))
-           (apply #'make-instance dep-o
-                  :parent o
-                  :original-initargs args args))
-          ((subtypep (type-of o) dep-o)
-           o)
-          (t
-           (apply #'make-instance dep-o
-                  :parent o :original-initargs args args)))))
-
-
-(defmethod visit-component ((o operation) (c component) data)
-  (unless (component-visited-p o c)
-    (setf (gethash (node-for o c)
-                   (operation-visited-nodes (operation-ancestor o)))
-          (cons t data))))
-
-(defmethod component-visited-p ((o operation) (c component))
-  (gethash (node-for o c)
-           (operation-visited-nodes (operation-ancestor o))))
-
-(defmethod (setf visiting-component) (new-value operation component)
-  ;; MCL complains about unused lexical variables
-  (declare (ignorable operation component))
-  new-value)
-
-(defmethod (setf visiting-component) (new-value (o operation) (c component))
-  (let ((node (node-for o c))
-        (a (operation-ancestor o)))
-    (if new-value
-        (setf (gethash node (operation-visiting-nodes a)) t)
-        (remhash node (operation-visiting-nodes a)))
-    new-value))
-
-(defmethod component-visiting-p ((o operation) (c component))
-  (let ((node (node-for o c)))
-    (gethash node (operation-visiting-nodes (operation-ancestor o)))))
-
-(defmethod component-depends-on ((op-spec symbol) (c component))
-  (component-depends-on (make-instance op-spec) c))
-
-(defmethod component-depends-on ((o operation) (c component))
-  (cdr (assoc (class-name (class-of o))
-              (component-in-order-to c))))
-
-(defmethod component-self-dependencies ((o operation) (c component))
-  (let ((all-deps (component-depends-on o c)))
-    (remove-if-not (lambda (x)
-                     (member (component-name c) (cdr x) :test #'string=))
-                   all-deps)))
-
-(defmethod input-files ((operation operation) (c component))
-  (let ((parent (component-parent c))
-        (self-deps (component-self-dependencies operation c)))
-    (if self-deps
-        (mapcan (lambda (dep)
-                  (destructuring-bind (op name) dep
-                    (output-files (make-instance op)
-                                  (find-component parent name))))
-                self-deps)
-        ;; no previous operations needed?  I guess we work with the
-        ;; original source file, then
-        (list (component-pathname c)))))
-
-(defmethod input-files ((operation operation) (c module))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod component-operation-time (o c)
-  (gethash (type-of o) (component-operation-times c)))
-
-(defmethod operation-done-p ((o operation) (c component))
-  (let ((out-files (output-files o c))
-        (in-files (input-files o c))
-        (op-time (component-operation-time o c)))
-    (flet ((earliest-out ()
-             (reduce #'min (mapcar #'safe-file-write-date out-files)))
-           (latest-in ()
-             (reduce #'max (mapcar #'safe-file-write-date in-files))))
-      (cond
-        ((and (not in-files) (not out-files))
-         ;; arbitrary decision: an operation that uses nothing to
-         ;; produce nothing probably isn't doing much.
-         ;; e.g. operations on systems, modules that have no immediate action,
-         ;; but are only meaningful through traversed dependencies
-         t)
-        ((not out-files)
-         ;; an operation without output-files is probably meant
-         ;; for its side-effects in the current image,
-         ;; assumed to be idem-potent,
-         ;; e.g. LOAD-OP or LOAD-SOURCE-OP of some CL-SOURCE-FILE.
-         (and op-time (>= op-time (latest-in))))
-        ((not in-files)
-         ;; an operation without output-files and no input-files
-         ;; is probably meant for its side-effects on the file-system,
-         ;; assumed to have to be done everytime.
-         ;; (I don't think there is any such case in ASDF unless extended)
-         nil)
-        (t
-         ;; an operation with both input and output files is assumed
-         ;; as computing the latter from the former,
-         ;; assumed to have been done if the latter are all older
-         ;; than the former.
-         ;; e.g. COMPILE-OP of some CL-SOURCE-FILE.
-         ;; We use >= instead of > to play nice with generated files.
-         ;; This opens a race condition if an input file is changed
-         ;; after the output is created but within the same second
-         ;; of filesystem time; but the same race condition exists
-         ;; whenever the computation from input to output takes more
-         ;; than one second of filesystem time (or just crosses the
-         ;; second). So that's cool.
-         (and
-          (every #'probe-file in-files)
-          (every #'probe-file out-files)
-          (>= (earliest-out) (latest-in))))))))
-
-
-
-;;; For 1.700 I've done my best to refactor TRAVERSE
-;;; by splitting it up in a bunch of functions,
-;;; so as to improve the collection and use-detection algorithm. --fare
-;;; The protocol is as follows: we pass around operation, dependency,
-;;; bunch of other stuff, and a force argument. Return a force flag.
-;;; The returned flag is T if anything has changed that requires a rebuild.
-;;; The force argument is a list of components that will require a rebuild
-;;; if the flag is T, at which point whoever returns the flag has to
-;;; mark them all as forced, and whoever recurses again can use a NIL list
-;;; as a further argument.
-
-(defvar *forcing* nil
-  "This dynamically-bound variable is used to force operations in
-recursive calls to traverse.")
-
-(defgeneric* do-traverse (operation component collect))
-
-(defun* %do-one-dep (operation c collect required-op required-c required-v)
-  ;; collects a partial plan that results from performing required-op
-  ;; on required-c, possibly with a required-vERSION
-  (let* ((dep-c (or (let ((d (find-component (component-parent c) required-c)))
-                      (and d (version-satisfies d required-v) d))
-                    (if required-v
-                        (error 'missing-dependency-of-version
-                               :required-by c
-                               :version required-v
-                               :requires required-c)
-                        (error 'missing-dependency
-                               :required-by c
-                               :requires required-c))))
-         (op (make-sub-operation c operation dep-c required-op)))
-    (do-traverse op dep-c collect)))
-
-(defun* do-one-dep (operation c collect required-op required-c required-v)
-  ;; this function is a thin, error-handling wrapper around %do-one-dep.
-  ;; Collects a partial plan per that function.
-  (loop
-    (restart-case
-        (return (%do-one-dep operation c collect
-                             required-op required-c required-v))
-      (retry ()
-        :report (lambda (s)
-                  (format s "~@<Retry loading component ~S.~@:>"
-                          (component-find-path required-c)))
-        :test
-        (lambda (c)
-          (or (null c)
-              (and (typep c 'missing-dependency)
-                   (equalp (missing-requires c)
-                           required-c))))))))
-
-(defun* do-dep (operation c collect op dep)
-  ;; type of arguments uncertain:
-  ;; op seems to at least potentially be a symbol, rather than an operation
-  ;; dep is a list of component names
-  (cond ((eq op 'feature)
-         (if (member (car dep) *features*)
-             nil
-             (error 'missing-dependency
-                    :required-by c
-                    :requires (car dep))))
-        (t
-         (let ((flag nil))
-           (flet ((dep (op comp ver)
-                    (when (do-one-dep operation c collect
-                                      op comp ver)
-                      (setf flag t))))
-             (dolist (d dep)
-               (if (atom d)
-                   (dep op d nil)
-                   ;; structured dependencies --- this parses keywords
-                   ;; the keywords could be broken out and cleanly (extensibly)
-                   ;; processed by EQL methods
-                   (cond ((eq :version (first d))
-                          ;; https://bugs.launchpad.net/asdf/+bug/527788
-                          (dep op (second d) (third d)))
-                         ;; This particular subform is not documented and
-                         ;; has always been broken in the past.
-                         ;; Therefore no one uses it, and I'm cerroring it out,
-                         ;; after fixing it
-                         ;; See https://bugs.launchpad.net/asdf/+bug/518467
-                         ((eq :feature (first d))
-                          (cerror "Continue nonetheless."
-                                  "Congratulations, you're the first ever user of FEATURE dependencies! Please contact the asdf-devel mailing-list.")
-                          (when (find (second d) *features* :test 'string-equal)
-                            (dep op (third d) nil)))
+(asdf/package:define-package :asdf/operation
+  (:recycle :asdf/operation :asdf/action :asdf) ;; asdf/action for FEATURE pre 2.31.5.
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade)
+  (:export
+   #:operation
+   #:operation-original-initargs ;; backward-compatibility only. DO NOT USE.
+   #:build-op ;; THE generic operation
+   #:*operations* #:make-operation #:find-operation #:feature))
+(in-package :asdf/operation)
+
+;;; Operation Classes
+
+(when-upgrading (:when (find-class 'operation nil))
+  (defmethod shared-initialize :after ((o operation) slot-names &rest initargs &key)
+    (declare (ignorable o slot-names initargs)) (values)))
+
+(with-upgradability ()
+  (defclass operation ()
+    ((original-initargs ;; for backward-compat -- used by GBBopen and swank (via operation-forced)
+      :initform nil :initarg :original-initargs :accessor operation-original-initargs)))
+
+  (defmethod initialize-instance :after ((o operation) &rest initargs
+                                         &key force force-not system verbose &allow-other-keys)
+    (declare (ignorable force force-not system verbose))
+    (unless (slot-boundp o 'original-initargs)
+      (setf (operation-original-initargs o) initargs)))
+
+  (defmethod print-object ((o operation) stream)
+    (print-unreadable-object (o stream :type t :identity nil)
+      (ignore-errors
+       (format stream "~{~S~^ ~}" (operation-original-initargs o))))))
+
+;;; make-operation, find-operation
+
+(with-upgradability ()
+  (defparameter *operations* (make-hash-table :test 'equal))
+  (defun make-operation (operation-class &rest initargs)
+    (let ((key (cons operation-class initargs)))
+      (multiple-value-bind (operation foundp) (gethash key *operations*)
+        (if foundp operation
+            (setf (gethash key *operations*)
+                  (apply 'make-instance operation-class initargs))))))
+
+  (defgeneric find-operation (context spec)
+    (:documentation "Find an operation by resolving the SPEC in the CONTEXT"))
+  (defmethod find-operation (context (spec operation))
+    (declare (ignorable context))
+    spec)
+  (defmethod find-operation (context (spec symbol))
+    (unless (member spec '(nil feature))
+      ;; NIL designates itself, i.e. absence of operation
+      ;; FEATURE is the ASDF1 misfeature that comes with IF-COMPONENT-DEP-FAILS
+      (apply 'make-operation spec (operation-original-initargs context))))
+  (defmethod operation-original-initargs ((context symbol))
+    (declare (ignorable context))
+    nil)
+
+  (defclass build-op (operation) ()))
+
+
+;;;; -------------------------------------------------------------------------
+;;;; Actions
+
+(asdf/package:define-package :asdf/action
+  (:nicknames :asdf-action)
+  (:recycle :asdf/action :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system #:asdf/cache :asdf/find-system :asdf/find-component :asdf/operation)
+  (:export
+   #:action #:define-convenience-action-methods
+   #:explain #:action-description
+   #:downward-operation #:upward-operation #:sideway-operation #:selfward-operation
+   #:component-depends-on
+   #:input-files #:output-files #:output-file #:operation-done-p
+   #:action-status #:action-stamp #:action-done-p
+   #:component-operation-time #:mark-operation-done #:compute-action-stamp
+   #:perform #:perform-with-restarts #:retry #:accept
+   #:traverse-actions #:traverse-sub-actions #:required-components ;; in plan
+   #:action-path #:find-action #:stamp #:done-p))
+(in-package :asdf/action)
+
+(eval-when (#-lispworks :compile-toplevel :load-toplevel :execute)
+  (deftype action () '(cons operation component))) ;; a step to be performed while building
+
+(with-upgradability ()
+  (defgeneric traverse-actions (actions &key &allow-other-keys))
+  (defgeneric traverse-sub-actions (operation component &key &allow-other-keys))
+  (defgeneric required-components (component &key &allow-other-keys)))
+
+;;;; Reified representation for storage or debugging. Note: dropping original-initargs
+(with-upgradability ()
+  (defun action-path (action)
+    (destructuring-bind (o . c) action (cons (type-of o) (component-find-path c))))
+  (defun find-action (path)
+    (destructuring-bind (o . c) path (cons (make-operation o) (find-component () c)))))
+
+
+;;;; Convenience methods
+(with-upgradability ()
+  (defmacro define-convenience-action-methods
+      (function (operation component &optional keyp)
+       &key if-no-operation if-no-component operation-initargs)
+    (let* ((rest (gensym "REST"))
+           (found (gensym "FOUND"))
+           (more-args (when keyp `(&rest ,rest &key &allow-other-keys))))
+      (flet ((next-method (o c)
+               (if keyp
+                   `(apply ',function ,o ,c ,rest)
+                   `(,function ,o ,c))))
+        `(progn
+           (defmethod ,function ((,operation symbol) ,component ,@more-args)
+             (if ,operation
+                 ,(next-method
+                   (if operation-initargs ;backward-compatibility with ASDF1's operate. Yuck.
+                       `(apply 'make-operation ,operation :original-initargs ,rest ,rest)
+                       `(make-operation ,operation))
+                   `(or (find-component () ,component) ,if-no-component))
+                 ,if-no-operation))
+           (defmethod ,function ((,operation operation) ,component ,@more-args)
+             (if (typep ,component 'component)
+                 (error "No defined method for ~S on ~/asdf-action:format-action/"
+                        ',function (cons ,operation ,component))
+                 (let ((,found (find-component () ,component)))
+                   (if ,found
+                       ,(next-method operation found)
+                       ,if-no-component)))))))))
+
+
+;;;; self-description
+(with-upgradability ()
+  (defgeneric action-description (operation component)
+    (:documentation "returns a phrase that describes performing this operation
+on this component, e.g. \"loading /a/b/c\".
+You can put together sentences using this phrase."))
+  (defmethod action-description (operation component)
+    (format nil (compatfmt "~@<~A on ~A~@:>")
+            (type-of operation) component))
+  (defgeneric* (explain) (operation component))
+  (defmethod explain ((o operation) (c component))
+    (asdf-message (compatfmt "~&~@<; ~@;~A~:>~%") (action-description o c)))
+  (define-convenience-action-methods explain (operation component))
+
+  (defun format-action (stream action &optional colon-p at-sign-p)
+    (assert (null colon-p)) (assert (null at-sign-p))
+    (destructuring-bind (operation . component) action
+      (princ (action-description operation component) stream))))
+
+
+;;;; Dependencies
+(with-upgradability ()
+  (defgeneric* (component-depends-on) (operation component) ;; ASDF4: rename to component-dependencies
+    (:documentation
+     "Returns a list of dependencies needed by the component to perform
+    the operation.  A dependency has one of the following forms:
+
+      (<operation> <component>*), where <operation> is an operation designator
+        with respect to FIND-OPERATION in the context of the OPERATION argument,
+        and each <component> is a component designator with respect to
+        FIND-COMPONENT in the context of the COMPONENT argument,
+        and means that the component depends on
+        <operation> having been performed on each <component>; or
+
+      (FEATURE <feature>), which means that the component depends
+        on the <feature> expression satisfying FEATUREP.
+        (This is DEPRECATED -- use :IF-FEATURE instead.)
+
+    Methods specialized on subclasses of existing component types
+    should usually append the results of CALL-NEXT-METHOD to the list."))
+  (define-convenience-action-methods component-depends-on (operation component))
+
+  (defmethod component-depends-on :around ((o operation) (c component))
+    (do-asdf-cache `(component-depends-on ,o ,c)
+      (call-next-method)))
+
+  (defmethod component-depends-on ((o operation) (c component))
+    (cdr (assoc (type-of o) (component-in-order-to c))))) ; User-specified in-order dependencies
+
+
+;;;; upward-operation, downward-operation
+;; These together handle actions that propagate along the component hierarchy.
+;; Downward operations like load-op or compile-op propagate down the hierarchy:
+;; operation on a parent depends-on operation on its children.
+;; By default, an operation propagates itself, but it may propagate another one instead.
+(with-upgradability ()
+  (defclass downward-operation (operation)
+    ((downward-operation
+      :initform nil :initarg :downward-operation :reader downward-operation :allocation :class)))
+  (defmethod component-depends-on ((o downward-operation) (c parent-component))
+    `((,(or (downward-operation o) o) ,@(component-children c)) ,@(call-next-method)))
+  ;; Upward operations like prepare-op propagate up the component hierarchy:
+  ;; operation on a child depends-on operation on its parent.
+  ;; By default, an operation propagates itself, but it may propagate another one instead.
+  (defclass upward-operation (operation)
+    ((upward-operation
+      :initform nil :initarg :downward-operation :reader upward-operation :allocation :class)))
+  ;; For backward-compatibility reasons, a system inherits from module and is a child-component
+  ;; so we must guard against this case. ASDF4: remove that.
+  (defmethod component-depends-on ((o upward-operation) (c child-component))
+    `(,@(if-let (p (component-parent c))
+          `((,(or (upward-operation o) o) ,p))) ,@(call-next-method)))
+  ;; Sibling operations propagate to siblings in the component hierarchy:
+  ;; operation on a child depends-on operation on its parent.
+  ;; By default, an operation propagates itself, but it may propagate another one instead.
+  (defclass sideway-operation (operation)
+    ((sideway-operation
+      :initform nil :initarg :sideway-operation :reader sideway-operation :allocation :class)))
+  (defmethod component-depends-on ((o sideway-operation) (c component))
+    `((,(or (sideway-operation o) o)
+       ,@(loop :for dep :in (component-sideway-dependencies c)
+               :collect (resolve-dependency-spec c dep)))
+      ,@(call-next-method)))
+  ;; Selfward operations propagate to themselves a sub-operation:
+  ;; they depend on some other operation being acted on the same component.
+  (defclass selfward-operation (operation)
+    ((selfward-operation
+      :initform nil :initarg :selfward-operation :reader selfward-operation :allocation :class)))
+  (defmethod component-depends-on ((o selfward-operation) (c component))
+    `(,@(loop :for op :in (ensure-list (selfward-operation o))
+              :collect `(,op ,c))
+      ,@(call-next-method))))
+
+
+;;;; Inputs, Outputs, and invisible dependencies
+(with-upgradability ()
+  (defgeneric* (output-files) (operation component))
+  (defgeneric* (input-files) (operation component))
+  (defgeneric* (operation-done-p) (operation component)
+    (:documentation "Returns a boolean, which is NIL if the action is forced to be performed again"))
+  (define-convenience-action-methods output-files (operation component))
+  (define-convenience-action-methods input-files (operation component))
+  (define-convenience-action-methods operation-done-p (operation component))
+
+  (defmethod operation-done-p ((o operation) (c component))
+    (declare (ignorable o c))
+    t)
+
+  (defmethod output-files :around (operation component)
+    "Translate output files, unless asked not to. Memoize the result."
+    operation component ;; hush genera, not convinced by declare ignorable(!)
+    (do-asdf-cache `(output-files ,operation ,component)
+      (values
+       (multiple-value-bind (pathnames fixedp) (call-next-method)
+         ;; 1- Make sure we have absolute pathnames
+         (let* ((directory (pathname-directory-pathname
+                            (component-pathname (find-component () component))))
+                (absolute-pathnames
+                  (loop
+                    :for pathname :in pathnames
+                    :collect (ensure-absolute-pathname pathname directory))))
+           ;; 2- Translate those pathnames as required
+           (if fixedp
+               absolute-pathnames
+               (mapcar *output-translation-function* absolute-pathnames))))
+       t)))
+  (defmethod output-files ((o operation) (c component))
+    (declare (ignorable o c))
+    nil)
+  (defun output-file (operation component)
+    "The unique output file of performing OPERATION on COMPONENT"
+    (let ((files (output-files operation component)))
+      (assert (length=n-p files 1))
+      (first files)))
+
+  (defmethod input-files :around (operation component)
+    "memoize input files."
+    (do-asdf-cache `(input-files ,operation ,component)
+      (call-next-method)))
+
+  (defmethod input-files ((o operation) (c component))
+    (declare (ignorable o c))
+    nil)
+
+  (defmethod input-files ((o selfward-operation) (c component))
+    `(,@(or (loop :for dep-o :in (ensure-list (selfward-operation o))
+                  :append (or (output-files dep-o c) (input-files dep-o c)))
+            (if-let ((pathname (component-pathname c)))
+              (and (file-pathname-p pathname) (list pathname))))
+      ,@(call-next-method))))
+
+
+;;;; Done performing
+(with-upgradability ()
+  (defgeneric component-operation-time (operation component)) ;; ASDF4: hide it behind plan-action-stamp
+  (define-convenience-action-methods component-operation-time (operation component))
+
+  (defgeneric mark-operation-done (operation component)) ;; ASDF4: hide it behind (setf plan-action-stamp)
+  (defgeneric compute-action-stamp (plan operation component &key just-done)
+    (:documentation "Has this action been successfully done already,
+and at what known timestamp has it been done at or will it be done at?
+Takes two keywords JUST-DONE and PLAN:
+JUST-DONE is a boolean that is true if the action was just successfully performed,
+at which point we want compute the actual stamp and warn if files are missing;
+otherwise we are making plans, anticipating the effects of the action.
+PLAN is a plan object modelling future effects of actions,
+or NIL to denote what actually happened.
+Returns two values:
+* a STAMP saying when it was done or will be done,
+  or T if the action has involves files that need to be recomputed.
+* a boolean DONE-P that indicates whether the action has actually been done,
+  and both its output-files and its in-image side-effects are up to date."))
+
+  (defclass action-status ()
+    ((stamp
+      :initarg :stamp :reader action-stamp
+      :documentation "STAMP associated with the ACTION if it has been completed already
+in some previous image, or T if it needs to be done.")
+     (done-p
+      :initarg :done-p :reader action-done-p
+      :documentation "a boolean, true iff the action was already done (before any planned action)."))
+    (:documentation "Status of an action"))
+
+  (defmethod print-object ((status action-status) stream)
+    (print-unreadable-object (status stream :type t)
+      (with-slots (stamp done-p) status
+        (format stream "~@{~S~^ ~}" :stamp stamp :done-p done-p))))
+
+  (defmethod component-operation-time ((o operation) (c component))
+    (gethash (type-of o) (component-operation-times c)))
+
+  (defmethod mark-operation-done ((o operation) (c component))
+    (setf (gethash (type-of o) (component-operation-times c))
+          (compute-action-stamp nil o c :just-done t))))
+
+
+;;;; Perform
+(with-upgradability ()
+  (defgeneric* (perform-with-restarts) (operation component))
+  (defgeneric* (perform) (operation component))
+  (define-convenience-action-methods perform (operation component))
+
+  (defmethod perform :before ((o operation) (c component))
+    (ensure-all-directories-exist (output-files o c)))
+  (defmethod perform :after ((o operation) (c component))
+    (mark-operation-done o c))
+  (defmethod perform ((o operation) (c parent-component))
+    (declare (ignorable o c))
+    nil)
+  (defmethod perform ((o operation) (c source-file))
+    (sysdef-error
+     (compatfmt "~@<Required method PERFORM not implemented for operation ~A, component ~A~@:>")
+     (class-of o) (class-of c)))
+
+  (defmethod perform-with-restarts (operation component)
+    ;; TOO verbose, especially as the default. Add your own :before method
+    ;; to perform-with-restart or perform if you want that:
+    #|(explain operation component)|#
+    (perform operation component))
+  (defmethod perform-with-restarts :around (operation component)
+    (loop
+      (restart-case
+          (return (call-next-method))
+        (retry ()
+          :report
+          (lambda (s)
+            (format s (compatfmt "~@<Retry ~A.~@:>")
+                    (action-description operation component))))
+        (accept ()
+          :report
+          (lambda (s)
+            (format s (compatfmt "~@<Continue, treating ~A as having been successful.~@:>")
+                    (action-description operation component)))
+          (mark-operation-done operation component)
+          (return))))))
+
+;;; Generic build operation
+(with-upgradability ()
+  (defmethod component-depends-on ((o build-op) (c component))
+    `((,(or (component-build-operation c) 'load-op) ,c))))
+
+;;;; -------------------------------------------------------------------------
+;;;; Actions to build Common Lisp software
+
+(asdf/package:define-package :asdf/lisp-action
+  (:recycle :asdf/lisp-action :asdf)
+  (:intern #:proclamations #:flags)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/cache :asdf/component :asdf/system :asdf/find-component :asdf/find-system
+   :asdf/operation :asdf/action)
+  (:export
+   #:try-recompiling
+   #:cl-source-file #:cl-source-file.cl #:cl-source-file.lsp
+   #:basic-load-op #:basic-compile-op #:compile-op-flags #:compile-op-proclamations
+   #:load-op #:prepare-op #:compile-op #:test-op #:load-source-op #:prepare-source-op
+   #:call-with-around-compile-hook
+   #:perform-lisp-compilation #:perform-lisp-load-fasl #:perform-lisp-load-source
+   #:lisp-compilation-output-files #:flags))
+(in-package :asdf/lisp-action)
+
+
+;;;; Component classes
+(with-upgradability ()
+  (defclass cl-source-file (source-file)
+    ((type :initform "lisp")))
+  (defclass cl-source-file.cl (cl-source-file)
+    ((type :initform "cl")))
+  (defclass cl-source-file.lsp (cl-source-file)
+    ((type :initform "lsp"))))
+
+
+;;;; Operation classes
+(with-upgradability ()
+  (defclass basic-load-op (operation) ())
+  (defclass basic-compile-op (operation)
+    ((proclamations :initarg :proclamations :accessor compile-op-proclamations :initform nil)
+     (flags :initarg :flags :accessor compile-op-flags
+            :initform nil))))
+
+;;; Our default operations: loading into the current lisp image
+(with-upgradability ()
+  (defclass prepare-op (upward-operation sideway-operation)
+    ((sideway-operation :initform 'load-op)))
+  (defclass load-op (basic-load-op downward-operation sideway-operation selfward-operation)
+    ;; NB: even though compile-op depends-on on prepare-op it is not needed-in-image-p,
+    ;; so we need to directly depend on prepare-op for its side-effects in the current image.
+    ((selfward-operation :initform '(prepare-op compile-op))))
+  (defclass compile-op (basic-compile-op downward-operation selfward-operation)
+    ((selfward-operation :initform 'prepare-op)
+     (downward-operation :initform 'load-op)))
+
+  (defclass prepare-source-op (upward-operation sideway-operation)
+    ((sideway-operation :initform 'load-source-op)))
+  (defclass load-source-op (basic-load-op downward-operation selfward-operation)
+    ((selfward-operation :initform 'prepare-source-op)))
+
+  (defclass test-op (selfward-operation)
+    ((selfward-operation :initform 'load-op))))
+
+
+;;;; prepare-op, compile-op and load-op
+
+;;; prepare-op
+(with-upgradability ()
+  (defmethod action-description ((o prepare-op) (c component))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<loading dependencies of ~3i~_~A~@:>") c))
+  (defmethod perform ((o prepare-op) (c component))
+    (declare (ignorable o c))
+    nil)
+  (defmethod input-files ((o prepare-op) (c component))
+    (declare (ignorable o c))
+    nil)
+  (defmethod input-files ((o prepare-op) (s system))
+    (declare (ignorable o))
+    (if-let (it (system-source-file s)) (list it))))
+
+;;; compile-op
+(with-upgradability ()
+  (defmethod action-description ((o compile-op) (c component))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<compiling ~3i~_~A~@:>") c))
+  (defmethod action-description ((o compile-op) (c parent-component))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<completing compilation for ~3i~_~A~@:>") c))
+  (defgeneric call-with-around-compile-hook (component thunk))
+  (defmethod call-with-around-compile-hook ((c component) function)
+    (call-around-hook (around-compile-hook c) function))
+  (defun perform-lisp-compilation (o c)
+    (let (;; Before 2.26.53, that was unfortunately component-pathname. Now,
+          ;; we consult input-files, the first of which should be the one to compile-file
+          (input-file (first (input-files o c)))
+          ;; on some implementations, there are more than one output-file,
+          ;; but the first one should always be the primary fasl that gets loaded.
+          (outputs (output-files o c)))
+      (multiple-value-bind (output warnings-p failure-p)
+          (destructuring-bind
+              (output-file
+               &optional
+                 #+clisp lib-file
+                 #+(or ecl mkcl) object-file
+                 warnings-file) outputs
+            (call-with-around-compile-hook
+             c #'(lambda (&rest flags)
+                   (with-muffled-compiler-conditions ()
+                     (apply 'compile-file* input-file
+                            :output-file output-file
+                            :external-format (component-external-format c)
+                            :warnings-file warnings-file
+                            (append
+                             #+clisp (list :lib-file lib-file)
+                             #+(or ecl mkcl) (list :object-file object-file)
+                             flags (compile-op-flags o)))))))
+        (check-lisp-compile-results output warnings-p failure-p
+                                    "~/asdf-action::format-action/" (list (cons o c))))))
+
+  (defun report-file-p (f)
+    (equalp (pathname-type f) "build-report"))
+  (defun perform-lisp-warnings-check (o c)
+    (let* ((expected-warnings-files (remove-if-not #'warnings-file-p (input-files o c)))
+           (actual-warnings-files (loop :for w :in expected-warnings-files
+                                        :when (get-file-stamp w)
+                                          :collect w
+                                        :else :do (warn "Missing warnings file ~S while ~A"
+                                                        w (action-description o c)))))
+      (check-deferred-warnings actual-warnings-files)
+      (let* ((output (output-files o c))
+             (report (find-if #'report-file-p output)))
+        (when report
+          (with-open-file (s report :direction :output :if-exists :supersede)
+            (format s ":success~%"))))))
+  (defmethod perform ((o compile-op) (c cl-source-file))
+    (perform-lisp-compilation o c))
+  (defun lisp-compilation-output-files (o c)
+    (let* ((i (first (input-files o c)))
+           (f (compile-file-pathname
+               i #+mkcl :fasl-p #+mkcl t #+ecl :type #+ecl :fasl)))
+      `(,f ;; the fasl is the primary output, in first position
+        #+clisp
+        ,@`(,(make-pathname :type "lib" :defaults f))
+        #+ecl
+        ,@(unless (use-ecl-byte-compiler-p)
+            `(,(compile-file-pathname i :type :object)))
+        #+mkcl
+        ,(compile-file-pathname i :fasl-p nil) ;; object file
+        ,@(when (and *warnings-file-type* (not (builtin-system-p (component-system c))))
+            `(,(make-pathname :type *warnings-file-type* :defaults f))))))
+  (defmethod output-files ((o compile-op) (c cl-source-file))
+    (lisp-compilation-output-files o c))
+  (defmethod perform ((o compile-op) (c static-file))
+    (declare (ignorable o c))
+    nil)
+  (defmethod output-files ((o compile-op) (c static-file))
+    (declare (ignorable o c))
+    nil)
+  (defmethod perform ((o compile-op) (c system))
+    (when (and *warnings-file-type* (not (builtin-system-p c)))
+      (perform-lisp-warnings-check o c)))
+  (defmethod input-files ((o compile-op) (c system))
+    (when (and *warnings-file-type* (not (builtin-system-p c)))
+      ;; The most correct way to do it would be to use:
+      ;; (traverse-sub-actions o c :other-systems nil :keep-operation 'compile-op :keep-component 'cl-source-file)
+      ;; but it's expensive and we don't care too much about file order or ASDF extensions.
+      (loop :for sub :in (sub-components c :type 'cl-source-file)
+            :nconc (remove-if-not 'warnings-file-p (output-files o sub)))))
+  (defmethod output-files ((o compile-op) (c system))
+    (when (and *warnings-file-type* (not (builtin-system-p c)))
+      (if-let ((pathname (component-pathname c)))
+        (list (subpathname pathname (coerce-filename c) :type "build-report"))))))
+
+;;; load-op
+(with-upgradability ()
+  (defmethod action-description ((o load-op) (c cl-source-file))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<loading FASL for ~3i~_~A~@:>") c))
+  (defmethod action-description ((o load-op) (c parent-component))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<completing load for ~3i~_~A~@:>") c))
+  (defmethod action-description ((o load-op) component)
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<loading ~3i~_~A~@:>")
+            component))
+  (defmethod perform-with-restarts ((o load-op) (c cl-source-file))
+    (loop
+      (restart-case
+          (return (call-next-method))
+        (try-recompiling ()
+          :report (lambda (s)
+                    (format s "Recompile ~a and try loading it again"
+                            (component-name c)))
+          (perform (find-operation o 'compile-op) c)))))
+  (defun perform-lisp-load-fasl (o c)
+    (if-let (fasl (first (input-files o c)))
+      (with-muffled-loader-conditions () (load* fasl))))
+  (defmethod perform ((o load-op) (c cl-source-file))
+    (perform-lisp-load-fasl o c))
+  (defmethod perform ((o load-op) (c static-file))
+    (declare (ignorable o c))
+    nil))
+
+
+;;;; prepare-source-op, load-source-op
+
+;;; prepare-source-op
+(with-upgradability ()
+  (defmethod action-description ((o prepare-source-op) (c component))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<loading source for dependencies of ~3i~_~A~@:>") c))
+  (defmethod input-files ((o prepare-source-op) (c component))
+    (declare (ignorable o c))
+    nil)
+  (defmethod input-files ((o prepare-source-op) (s system))
+    (declare (ignorable o))
+    (if-let (it (system-source-file s)) (list it)))
+  (defmethod perform ((o prepare-source-op) (c component))
+    (declare (ignorable o c))
+    nil))
+
+;;; load-source-op
+(with-upgradability ()
+  (defmethod action-description ((o load-source-op) c)
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<Loading source of ~3i~_~A~@:>") c))
+  (defmethod action-description ((o load-source-op) (c parent-component))
+    (declare (ignorable o))
+    (format nil (compatfmt "~@<Loaded source of ~3i~_~A~@:>") c))
+  (defun perform-lisp-load-source (o c)
+    (call-with-around-compile-hook
+     c #'(lambda ()
+           (with-muffled-loader-conditions ()
+             (load* (first (input-files o c))
+                    :external-format (component-external-format c))))))
+
+  (defmethod perform ((o load-source-op) (c cl-source-file))
+    (perform-lisp-load-source o c))
+  (defmethod perform ((o load-source-op) (c static-file))
+    (declare (ignorable o c))
+    nil)
+  (defmethod output-files ((o load-source-op) (c component))
+    (declare (ignorable o c))
+    nil))
+
+
+;;;; test-op
+(with-upgradability ()
+  (defmethod perform ((o test-op) (c component))
+    (declare (ignorable o c))
+    nil)
+  (defmethod operation-done-p ((o test-op) (c system))
+    "Testing a system is _never_ done."
+    (declare (ignorable o c))
+    nil))
+
+;;;; -------------------------------------------------------------------------
+;;;; Plan
+
+(asdf/package:define-package :asdf/plan
+  (:recycle :asdf/plan :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/operation :asdf/system
+   :asdf/cache :asdf/find-system :asdf/find-component
+   :asdf/operation :asdf/action :asdf/lisp-action)
+  (:export
+   #:component-operation-time #:mark-operation-done
+   #:plan-traversal #:sequential-plan #:*default-plan-class*
+   #:planned-action-status #:plan-action-status #:action-already-done-p
+   #:circular-dependency #:circular-dependency-actions
+   #:node-for #:needed-in-image-p
+   #:action-index #:action-planned-p #:action-valid-p
+   #:plan-record-dependency
+   #:normalize-forced-systems #:action-forced-p #:action-forced-not-p
+   #:map-direct-dependencies #:reduce-direct-dependencies #:direct-dependencies
+   #:visit-dependencies #:compute-action-stamp #:traverse-action
+   #:circular-dependency #:circular-dependency-actions
+   #:call-while-visiting-action #:while-visiting-action
+   #:traverse #:plan-actions #:perform-plan #:plan-operates-on-p
+   #:planned-p #:index #:forced #:forced-not #:total-action-count
+   #:planned-action-count #:planned-output-action-count #:visited-actions
+   #:visiting-action-set #:visiting-action-list #:plan-actions-r
+   #:required-components #:filtered-sequential-plan
+   #:plan-system
+   #:plan-action-filter #:plan-component-type #:plan-keep-operation #:plan-keep-component
+   #:traverse-actions #:traverse-sub-actions))
+(in-package :asdf/plan)
+
+;;;; Generic plan traversal class
+(with-upgradability ()
+  (defclass plan-traversal ()
+    ((system :initform nil :initarg :system :accessor plan-system)
+     (forced :initform nil :initarg :force :accessor plan-forced)
+     (forced-not :initform nil :initarg :force-not :accessor plan-forced-not)
+     (total-action-count :initform 0 :accessor plan-total-action-count)
+     (planned-action-count :initform 0 :accessor plan-planned-action-count)
+     (planned-output-action-count :initform 0 :accessor plan-planned-output-action-count)
+     (visited-actions :initform (make-hash-table :test 'equal) :accessor plan-visited-actions)
+     (visiting-action-set :initform (make-hash-table :test 'equal) :accessor plan-visiting-action-set)
+     (visiting-action-list :initform () :accessor plan-visiting-action-list))))
+
+
+;;;; Planned action status
+(with-upgradability ()
+  (defgeneric plan-action-status (plan operation component)
+    (:documentation "Returns the ACTION-STATUS associated to
+the action of OPERATION on COMPONENT in the PLAN"))
+
+  (defgeneric (setf plan-action-status) (new-status plan operation component)
+    (:documentation "Sets the ACTION-STATUS associated to
+the action of OPERATION on COMPONENT in the PLAN"))
+
+  (defclass planned-action-status (action-status)
+    ((planned-p
+      :initarg :planned-p :reader action-planned-p
+      :documentation "a boolean, true iff the action was included in the plan.")
+     (index
+      :initarg :index :reader action-index
+      :documentation "an integer, counting all traversed actions in traversal order."))
+    (:documentation "Status of an action in a plan"))
+
+  (defmethod print-object ((status planned-action-status) stream)
+    (print-unreadable-object (status stream :type t :identity nil)
+      (with-slots (stamp done-p planned-p index) status
+        (format stream "~@{~S~^ ~}" :stamp stamp :done-p done-p :planned-p planned-p :index index))))
+
+  (defmethod action-planned-p (action-status)
+    (declare (ignorable action-status)) ; default method for non planned-action-status objects
+    t)
+
+  ;; TODO: eliminate NODE-FOR, use CONS.
+  ;; Supposes cleaner protocol for operation initargs passed to MAKE-OPERATION.
+  ;; However, see also component-operation-time and mark-operation-done
+  (defun node-for (o c) (cons (type-of o) c))
+
+  (defun action-already-done-p (plan operation component)
+    (action-done-p (plan-action-status plan operation component)))
+
+  (defmethod plan-action-status ((plan null) (o operation) (c component))
+    (declare (ignorable plan))
+    (multiple-value-bind (stamp done-p) (component-operation-time o c)
+      (make-instance 'action-status :stamp stamp :done-p done-p)))
+
+  (defmethod (setf plan-action-status) (new-status (plan null) (o operation) (c component))
+    (declare (ignorable plan))
+    (let ((to (type-of o))
+          (times (component-operation-times c)))
+      (if (action-done-p new-status)
+          (remhash to times)
+          (setf (gethash to times) (action-stamp new-status))))
+    new-status))
+
+
+;;;; forcing
+(with-upgradability ()
+  (defgeneric action-forced-p (plan operation component))
+  (defgeneric action-forced-not-p (plan operation component))
+
+  (defun normalize-forced-systems (x system)
+    (etypecase x
+      ((member nil :all) x)
+      (cons (list-to-hash-set (mapcar #'coerce-name x)))
+      ((eql t) (when system (list-to-hash-set (list (coerce-name system)))))))
+
+  (defun action-override-p (plan operation component override-accessor)
+    (declare (ignorable operation))
+    (let* ((override (funcall override-accessor plan)))
+      (and override
+           (if (typep override 'hash-table)
+               (gethash (coerce-name (component-system (find-component () component))) override)
+               t))))
+
+  (defmethod action-forced-p (plan operation component)
+    (and
+     ;; Did the user ask us to re-perform the action?
+     (action-override-p plan operation component 'plan-forced)
+     ;; You really can't force a builtin system and :all doesn't apply to it,
+     ;; except it it's the specifically the system currently being built.
+     (not (let ((system (component-system component)))
+            (and (builtin-system-p system)
+                 (not (eq system (plan-system plan))))))))
+
+  (defmethod action-forced-not-p (plan operation component)
+    (and
+     ;; Did the user ask us to not re-perform the action?
+     (action-override-p plan operation component 'plan-forced-not)
+     ;; Force takes precedence over force-not
+     (not (action-forced-p plan operation component))))
+
+  (defmethod action-forced-p ((plan null) operation component)
+    (declare (ignorable plan operation component))
+    nil)
+
+  (defmethod action-forced-not-p ((plan null) operation component)
+    (declare (ignorable plan operation component))
+    nil))
+
+
+;;;; action-valid-p
+(with-upgradability ()
+  (defgeneric action-valid-p (plan operation component)
+    (:documentation "Is this action valid to include amongst dependencies?"))
+  (defmethod action-valid-p (plan operation (c component))
+    (declare (ignorable plan operation))
+    (if-let (it (component-if-feature c)) (featurep it) t))
+  (defmethod action-valid-p (plan (o null) c) (declare (ignorable plan o c)) nil)
+  (defmethod action-valid-p (plan o (c null)) (declare (ignorable plan o c)) nil)
+  (defmethod action-valid-p ((plan null) operation component)
+    (declare (ignorable plan operation component))
+    (and operation component t)))
+
+
+;;;; Is the action needed in this image?
+(with-upgradability ()
+  (defgeneric needed-in-image-p (operation component)
+    (:documentation "Is the action of OPERATION on COMPONENT needed in the current image to be meaningful,
+    or could it just as well have been done in another Lisp image?"))
+
+  (defmethod needed-in-image-p ((o operation) (c component))
+    ;; We presume that actions that modify the filesystem don't need be run
+    ;; in the current image if they have already been done in another,
+    ;; and can be run in another process (e.g. a fork),
+    ;; whereas those that don't are meant to side-effect the current image and can't.
+    (not (output-files o c))))
+
+
+;;;; Visiting dependencies of an action and computing action stamps
+(with-upgradability ()
+  (defun map-direct-dependencies (operation component fun)
+    (loop* :for (dep-o-spec . dep-c-specs) :in (component-depends-on operation component)
+           :for dep-o = (find-operation operation dep-o-spec)
+           :when dep-o
+           :do (loop :for dep-c-spec :in dep-c-specs
+                     :for dep-c = (and dep-c-spec (resolve-dependency-spec component dep-c-spec))
+                     :when dep-c
+                       :do (funcall fun dep-o dep-c))))
+
+  (defun reduce-direct-dependencies (operation component combinator seed)
+    (map-direct-dependencies
+     operation component
+     #'(lambda (dep-o dep-c)
+         (setf seed (funcall combinator dep-o dep-c seed))))
+    seed)
+
+  (defun direct-dependencies (operation component)
+    (reduce-direct-dependencies operation component #'acons nil))
+
+  (defun visit-dependencies (plan operation component dependency-stamper &aux stamp)
+    (map-direct-dependencies
+     operation component
+     #'(lambda (dep-o dep-c)
+         (when (action-valid-p plan dep-o dep-c)
+           (latest-stamp-f stamp (funcall dependency-stamper dep-o dep-c)))))
+    stamp)
+
+  (defmethod compute-action-stamp (plan (o operation) (c component) &key just-done)
+    ;; In a distant future, get-file-stamp and component-operation-time
+    ;; shall also be parametrized by the plan, or by a second model object.
+    (let* ((stamp-lookup #'(lambda (o c)
+                             (if-let (it (plan-action-status plan o c)) (action-stamp it) t)))
+           (out-files (output-files o c))
+           (in-files (input-files o c))
+           ;; Three kinds of actions:
+           (out-op (and out-files t)) ; those that create files on the filesystem
+                                        ;(image-op (and in-files (null out-files))) ; those that load stuff into the image
+                                        ;(null-op (and (null out-files) (null in-files))) ; dependency placeholders that do nothing
+           ;; When was the thing last actually done? (Now, or ask.)
+           (op-time (or just-done (component-operation-time o c)))
+           ;; Accumulated timestamp from dependencies (or T if forced or out-of-date)
+           (dep-stamp (visit-dependencies plan o c stamp-lookup))
+           ;; Time stamps from the files at hand, and whether any is missing
+           (out-stamps (mapcar (if just-done 'register-file-stamp 'get-file-stamp) out-files))
+           (in-stamps (mapcar #'get-file-stamp in-files))
+           (missing-in
+             (loop :for f :in in-files :for s :in in-stamps :unless s :collect f))
+           (missing-out
+             (loop :for f :in out-files :for s :in out-stamps :unless s :collect f))
+           (all-present (not (or missing-in missing-out)))
+           ;; Has any input changed since we last generated the files?
+           (earliest-out (stamps-earliest out-stamps))
+           (latest-in (stamps-latest (cons dep-stamp in-stamps)))
+           (up-to-date-p (stamp<= latest-in earliest-out))
+           ;; If everything is up to date, the latest of inputs and outputs is our stamp
+           (done-stamp (stamps-latest (cons latest-in out-stamps))))
+      ;; Warn if some files are missing:
+      ;; either our model is wrong or some other process is messing with our files.
+      (when (and just-done (not all-present))
+        (warn "~A completed without ~:[~*~;~*its input file~:p~2:*~{ ~S~}~*~]~
+             ~:[~; or ~]~:[~*~;~*its output file~:p~2:*~{ ~S~}~*~]"
+              (action-description o c)
+              missing-in (length missing-in) (and missing-in missing-out)
+              missing-out (length missing-out)))
+      ;; Note that we use stamp<= instead of stamp< to play nice with generated files.
+      ;; Any race condition is intrinsic to the limited timestamp resolution.
+      (if (or just-done ;; The done-stamp is valid: if we're just done, or
+              ;; if all filesystem effects are up-to-date and there's no invalidating reason.
+              (and all-present up-to-date-p (operation-done-p o c) (not (action-forced-p plan o c))))
+          (values done-stamp ;; return the hard-earned timestamp
+                  (or just-done
+                      (or out-op ;; a file-creating op is done when all files are up to date
+                          ;; a image-effecting a placeholder op is done when it was actually run,
+                          (and op-time (eql op-time done-stamp))))) ;; with the matching stamp
+          ;; done-stamp invalid: return a timestamp in an indefinite future, action not done yet
+          (values t nil)))))
+
+
+;;;; Generic support for plan-traversal
+(with-upgradability ()
+  (defgeneric plan-record-dependency (plan operation component))
+
+  (defgeneric call-while-visiting-action (plan operation component function)
+    (:documentation "Detect circular dependencies"))
+
+  (defmethod initialize-instance :after ((plan plan-traversal)
+                                         &key (force () fp) (force-not () fnp) system
+                                         &allow-other-keys)
+    (with-slots (forced forced-not) plan
+      (when fp (setf forced (normalize-forced-systems force system)))
+      (when fnp (setf forced-not (normalize-forced-systems force-not system)))))
+
+  (defmethod (setf plan-action-status) (new-status (plan plan-traversal) (o operation) (c component))
+    (setf (gethash (node-for o c) (plan-visited-actions plan)) new-status))
+
+  (defmethod plan-action-status ((plan plan-traversal) (o operation) (c component))
+    (or (and (action-forced-not-p plan o c) (plan-action-status nil o c))
+        (values (gethash (node-for o c) (plan-visited-actions plan)))))
+
+  (defmethod action-valid-p ((plan plan-traversal) (o operation) (s system))
+    (and (not (action-forced-not-p plan o s)) (call-next-method)))
+
+  (defmethod call-while-visiting-action ((plan plan-traversal) operation component fun)
+    (with-accessors ((action-set plan-visiting-action-set)
+                     (action-list plan-visiting-action-list)) plan
+      (let ((action (cons operation component)))
+        (when (gethash action action-set)
+          (error 'circular-dependency :actions
+                 (member action (reverse action-list) :test 'equal)))
+        (setf (gethash action action-set) t)
+        (push action action-list)
+        (unwind-protect
+             (funcall fun)
+          (pop action-list)
+          (setf (gethash action action-set) nil))))))
+
+
+;;;; Actual traversal: traverse-action
+(with-upgradability ()
+  (define-condition circular-dependency (system-definition-error)
+    ((actions :initarg :actions :reader circular-dependency-actions))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<Circular dependency: ~3i~_~S~@:>")
+                       (circular-dependency-actions c)))))
+
+  (defmacro while-visiting-action ((p o c) &body body)
+    `(call-while-visiting-action ,p ,o ,c #'(lambda () ,@body)))
+
+  (defgeneric traverse-action (plan operation component needed-in-image-p))
+
+  (defmethod traverse-action (plan operation component needed-in-image-p)
+    (block nil
+      (unless (action-valid-p plan operation component) (return nil))
+      (plan-record-dependency plan operation component)
+      (let* ((aniip (needed-in-image-p operation component))
+             (eniip (and aniip needed-in-image-p))
+             (status (plan-action-status plan operation component)))
+        (when (and status (or (action-done-p status) (action-planned-p status) (not eniip)))
+          ;; Already visited with sufficient need-in-image level: just return the stamp.
+          (return (action-stamp status)))
+        (labels ((visit-action (niip)
+                   (visit-dependencies plan operation component
+                                       #'(lambda (o c) (traverse-action plan o c niip)))
+                   (multiple-value-bind (stamp done-p)
+                       (compute-action-stamp plan operation component)
+                     (let ((add-to-plan-p (or (eql stamp t) (and niip (not done-p)))))
+                       (cond
+                         ((and add-to-plan-p (not niip)) ;; if we need to do it,
+                          (visit-action t)) ;; then we need to do it in the image!
                          (t
-                          (error "Bad dependency ~a.  Dependencies must be (:version <version>), (:feature <feature> [version]), or a name" d))))))
-           flag))))
-
-(defvar *visit-count* 0) ; counter that allows to sort nodes from operation-visited-nodes
-
-(defun* do-collect (collect x)
-  (funcall collect x))
-
-(defmethod do-traverse ((operation operation) (c component) collect)
-  (let ((flag nil)) ;; return value: must we rebuild this and its dependencies?
-    (labels
-        ((update-flag (x)
-           (when x
-             (setf flag t)))
-         (dep (op comp)
-           (update-flag (do-dep operation c collect op comp))))
-      ;; Have we been visited yet? If so, just process the result.
-      (aif (component-visited-p operation c)
-           (progn
-             (update-flag (cdr it))
-             (return-from do-traverse flag)))
-      ;; dependencies
-      (when (component-visiting-p operation c)
-        (error 'circular-dependency :components (list c)))
-      (setf (visiting-component operation c) t)
-      (unwind-protect
-           (progn
-             ;; first we check and do all the dependencies for the module.
-             ;; Operations planned in this loop will show up
-             ;; in the results, and are consumed below.
-             (let ((*forcing* nil))
-               ;; upstream dependencies are never forced to happen just because
-               ;; the things that depend on them are....
-               (loop
-                 :for (required-op . deps) :in (component-depends-on operation c)
-                 :do (dep required-op deps)))
-             ;; constituent bits
-             (let ((module-ops
-                    (when (typep c 'module)
-                      (let ((at-least-one nil)
-                            ;; This is set based on the results of the
-                            ;; dependencies and whether we are in the
-                            ;; context of a *forcing* call...
-                            ;; inter-system dependencies do NOT trigger
-                            ;; building components
-                            (*forcing*
-                             (or *forcing*
-                                 (and flag (not (typep c 'system)))))
-                            (error nil))
-                        (while-collecting (internal-collect)
-                          (dolist (kid (module-components c))
-                            (handler-case
-                                (update-flag
-                                 (do-traverse operation kid #'internal-collect))
-                              (missing-dependency (condition)
-                                (when (eq (module-if-component-dep-fails c)
-                                          :fail)
-                                  (error condition))
-                                (setf error condition))
-                              (:no-error (c)
-                                (declare (ignore c))
-                                (setf at-least-one t))))
-                          (when (and (eq (module-if-component-dep-fails c)
-                                         :try-next)
-                                     (not at-least-one))
-                            (error error)))))))
-               (update-flag
-                (or
-                 *forcing*
-                 (not (operation-done-p operation c))
-                 ;; For sub-operations, check whether
-                 ;; the original ancestor operation was forced,
-                 ;; or names us amongst an explicit list of things to force...
-                 ;; except that this check doesn't distinguish
-                 ;; between all the things with a given name. Sigh.
-                 ;; BROKEN!
-                 (let ((f (operation-forced
-                           (operation-ancestor operation))))
-                   (and f (or (not (consp f)) ;; T or :ALL
-                              (and (typep c 'system) ;; list of names of systems to force
-                                   (member (component-name c) f
-                                           :test #'string=)))))))
-               (when flag
-                 (let ((do-first (cdr (assoc (class-name (class-of operation))
-                                             (component-do-first c)))))
-                   (loop :for (required-op . deps) :in do-first
-                     :do (do-dep operation c collect required-op deps)))
-                 (do-collect collect (vector module-ops))
-                 (do-collect collect (cons operation c)))))
-             (setf (visiting-component operation c) nil)))
-      (visit-component operation c (when flag (incf *visit-count*)))
-      flag))
-
-(defun* flatten-tree (l)
-  ;; You collected things into a list.
-  ;; Most elements are just things to collect again.
-  ;; A (simple-vector 1) indicate that you should recurse into its contents.
-  ;; This way, in two passes (rather than N being the depth of the tree),
-  ;; you can collect things with marginally constant-time append,
-  ;; achieving linear time collection instead of quadratic time.
-  (while-collecting (c)
-    (labels ((r (x)
-               (if (typep x '(simple-vector 1))
-                   (r* (svref x 0))
-                   (c x)))
-             (r* (l)
-               (dolist (x l) (r x))))
-      (r* l))))
-
-(defmethod traverse ((operation operation) (c component))
-  ;; cerror'ing a feature that seems to have NEVER EVER worked
-  ;; ever since danb created it in his 2003-03-16 commit e0d02781.
-  ;; It was both fixed and disabled in the 1.700 rewrite.
-  (when (consp (operation-forced operation))
-    (cerror "Continue nonetheless."
-            "Congratulations, you're the first ever user of the :force (list of system names) feature! Please contact the asdf-devel mailing-list to collect a cookie.")
-    (setf (operation-forced operation)
-          (mapcar #'coerce-name (operation-forced operation))))
-  (flatten-tree
-   (while-collecting (collect)
-     (let ((*visit-count* 0))
-       (do-traverse operation c #'collect)))))
-
-(defmethod perform ((operation operation) (c source-file))
-  (sysdef-error
-   "~@<required method PERFORM not implemented for operation ~A, component ~A~@:>"
-   (class-of operation) (class-of c)))
-
-(defmethod perform ((operation operation) (c module))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod explain ((operation operation) (component component))
-  (asdf-message "~&;;; ~A~%" (operation-description operation component)))
-
-(defmethod operation-description (operation component)
-  (format nil "~A on component ~S" (class-of operation) (component-find-path component)))
-
-;;;; -------------------------------------------------------------------------
-;;;; compile-op
-
-(defclass compile-op (operation)
-  ((proclamations :initarg :proclamations :accessor compile-op-proclamations :initform nil)
-   (on-warnings :initarg :on-warnings :accessor operation-on-warnings
-                :initform *compile-file-warnings-behaviour*)
-   (on-failure :initarg :on-failure :accessor operation-on-failure
-               :initform *compile-file-failure-behaviour*)
-   (flags :initarg :flags :accessor compile-op-flags
-          :initform #-ecl nil #+ecl '(:system-p t))))
-
-(defun output-file (operation component)
-  "The unique output file of performing OPERATION on COMPONENT"
-  (let ((files (output-files operation component)))
-    (assert (length=n-p files 1))
-    (first files)))
-
-(defmethod perform :before ((operation compile-op) (c source-file))
-  (map nil #'ensure-directories-exist (output-files operation c)))
-
-#+ecl
-(defmethod perform :after ((o compile-op) (c cl-source-file))
-  ;; Note how we use OUTPUT-FILES to find the binary locations
-  ;; This allows the user to override the names.
-  (let* ((files (output-files o c))
-         (object (first files))
-         (fasl (second files)))
-    (c:build-fasl fasl :lisp-files (list object))))
-
-(defmethod perform :after ((operation operation) (c component))
-  (setf (gethash (type-of operation) (component-operation-times c))
-        (get-universal-time)))
-
-(declaim (ftype (function ((or pathname string)
-                           &rest t &key (:output-file t) &allow-other-keys)
-                          (values t t t))
-                compile-file*))
-
-;;; perform is required to check output-files to find out where to put
-;;; its answers, in case it has been overridden for site policy
-(defmethod perform ((operation compile-op) (c cl-source-file))
-  #-:broken-fasl-loader
-  (let ((source-file (component-pathname c))
-        ;; on some implementations, there are more than one output-file,
-        ;; but the first one should always be the primary fasl that gets loaded.
-        (output-file (first (output-files operation c)))
-        (*compile-file-warnings-behaviour* (operation-on-warnings operation))
-        (*compile-file-failure-behaviour* (operation-on-failure operation)))
-    (multiple-value-bind (output warnings-p failure-p)
-        (apply #'compile-file* source-file :output-file output-file
-               (compile-op-flags operation))
-      (when warnings-p
-        (case (operation-on-warnings operation)
-          (:warn (warn
-                  "~@<COMPILE-FILE warned while performing ~A on ~A.~@:>"
-                  operation c))
-          (:error (error 'compile-warned :component c :operation operation))
-          (:ignore nil)))
-      (when failure-p
-        (case (operation-on-failure operation)
-          (:warn (warn
-                  "~@<COMPILE-FILE failed while performing ~A on ~A.~@:>"
-                  operation c))
-          (:error (error 'compile-failed :component c :operation operation))
-          (:ignore nil)))
-      (unless output
-        (error 'compile-error :component c :operation operation)))))
-
-(defmethod output-files ((operation compile-op) (c cl-source-file))
-  (declare (ignorable operation))
-  (let ((p (lispize-pathname (component-pathname c))))
-    #-:broken-fasl-loader
-    (list (compile-file-pathname p #+ecl :type #+ecl :object)
-          #+ecl (compile-file-pathname p :type :fasl))
-    #+:broken-fasl-loader (list p)))
-
-(defmethod perform ((operation compile-op) (c static-file))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod output-files ((operation compile-op) (c static-file))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod input-files ((operation compile-op) (c static-file))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod operation-description ((operation compile-op) component)
-  (declare (ignorable operation))
-  (format nil "compiling component ~S" (component-find-path component)))
-
-;;;; -------------------------------------------------------------------------
-;;;; load-op
-
-(defclass basic-load-op (operation) ())
-
-(defclass load-op (basic-load-op) ())
-
-(defmethod perform ((o load-op) (c cl-source-file))
-  (map () #'load
-       #-ecl (input-files o c)
-       #+ecl (loop :for i :in (input-files o c)
-               :unless (string= (pathname-type i) "fas")
-               :collect (compile-file-pathname (lispize-pathname i)))))
-
-(defmethod perform-with-restarts (operation component)
-  (perform operation component))
-
-(defmethod perform-with-restarts ((o load-op) (c cl-source-file))
-  (declare (ignorable o))
-  (loop :with state = :initial
-    :until (or (eq state :success)
-               (eq state :failure)) :do
-    (case state
-      (:recompiled
-       (setf state :failure)
-       (call-next-method)
-       (setf state :success))
-      (:failed-load
-       (setf state :recompiled)
-       (perform (make-instance 'compile-op) c))
-      (t
-       (with-simple-restart
-           (try-recompiling "Recompile ~a and try loading it again"
-                            (component-name c))
-         (setf state :failed-load)
-         (call-next-method)
-         (setf state :success))))))
-
-(defmethod perform-with-restarts ((o compile-op) (c cl-source-file))
-  (loop :with state = :initial
-    :until (or (eq state :success)
-               (eq state :failure)) :do
-    (case state
-      (:recompiled
-       (setf state :failure)
-       (call-next-method)
-       (setf state :success))
-      (:failed-compile
-       (setf state :recompiled)
-       (perform-with-restarts o c))
-      (t
-       (with-simple-restart
-           (try-recompiling "Try recompiling ~a"
-                            (component-name c))
-         (setf state :failed-compile)
-         (call-next-method)
-         (setf state :success))))))
-
-(defmethod perform ((operation load-op) (c static-file))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod operation-done-p ((operation load-op) (c static-file))
-  (declare (ignorable operation c))
-  t)
-
-(defmethod output-files ((operation operation) (c component))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod component-depends-on ((operation load-op) (c component))
-  (declare (ignorable operation))
-  (cons (list 'compile-op (component-name c))
-        (call-next-method)))
-
-(defmethod operation-description ((operation load-op) component)
-  (declare (ignorable operation))
-  (format nil "loading component ~S" (component-find-path component)))
-
-
-;;;; -------------------------------------------------------------------------
-;;;; load-source-op
-
-(defclass load-source-op (basic-load-op) ())
-
-(defmethod perform ((o load-source-op) (c cl-source-file))
-  (declare (ignorable o))
-  (let ((source (component-pathname c)))
-    (setf (component-property c 'last-loaded-as-source)
-          (and (load source)
-               (get-universal-time)))))
-
-(defmethod perform ((operation load-source-op) (c static-file))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod output-files ((operation load-source-op) (c component))
-  (declare (ignorable operation c))
-  nil)
-
-;;; FIXME: we simply copy load-op's dependencies.  this is Just Not Right.
-(defmethod component-depends-on ((o load-source-op) (c component))
-  (declare (ignorable o))
-  (let ((what-would-load-op-do (cdr (assoc 'load-op
-                                           (component-in-order-to c)))))
-    (mapcar (lambda (dep)
-              (if (eq (car dep) 'load-op)
-                  (cons 'load-source-op (cdr dep))
-                  dep))
-            what-would-load-op-do)))
-
-(defmethod operation-done-p ((o load-source-op) (c source-file))
-  (declare (ignorable o))
-  (if (or (not (component-property c 'last-loaded-as-source))
-          (> (safe-file-write-date (component-pathname c))
-             (component-property c 'last-loaded-as-source)))
-      nil t))
-
-(defmethod operation-description ((operation load-source-op) component)
-  (declare (ignorable operation))
-  (format nil "loading component ~S" (component-find-path component)))
-
-
-;;;; -------------------------------------------------------------------------
-;;;; test-op
-
-(defclass test-op (operation) ())
-
-(defmethod perform ((operation test-op) (c component))
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod operation-done-p ((operation test-op) (c system))
-  "Testing a system is _never_ done."
-  (declare (ignorable operation c))
-  nil)
-
-(defmethod component-depends-on :around ((o test-op) (c system))
-  (declare (ignorable o))
-  (cons `(load-op ,(component-name c)) (call-next-method)))
-
+                          (setf (plan-action-status plan operation component)
+                                (make-instance
+                                 'planned-action-status
+                                 :stamp stamp
+                                 :done-p (and done-p (not add-to-plan-p))
+                                 :planned-p add-to-plan-p
+                                 :index (if status (action-index status) (incf (plan-total-action-count plan)))))
+                          (when add-to-plan-p
+                            (incf (plan-planned-action-count plan))
+                            (unless aniip
+                              (incf (plan-planned-output-action-count plan))))
+                          stamp))))))
+          (while-visiting-action (plan operation component) ; maintain context, handle circularity.
+            (visit-action eniip)))))))
+
+
+;;;; Sequential plans (the default)
+(with-upgradability ()
+  (defclass sequential-plan (plan-traversal)
+    ((actions-r :initform nil :accessor plan-actions-r)))
+
+  (defgeneric plan-actions (plan))
+  (defmethod plan-actions ((plan sequential-plan))
+    (reverse (plan-actions-r plan)))
+
+  (defmethod plan-record-dependency ((plan sequential-plan)
+                                     (operation operation) (component component))
+    (declare (ignorable plan operation component))
+    (values))
+
+  (defmethod (setf plan-action-status) :after
+      (new-status (p sequential-plan) (o operation) (c component))
+    (when (action-planned-p new-status)
+      (push (cons o c) (plan-actions-r p)))))
+
+
+;;;; high-level interface: traverse, perform-plan, plan-operates-on-p
+(with-upgradability ()
+  (defgeneric* (traverse) (operation component &key &allow-other-keys)
+    (:documentation
+     "Generate and return a plan for performing OPERATION on COMPONENT.
+
+The plan returned is a list of dotted-pairs. Each pair is the CONS
+of ASDF operation object and a COMPONENT object. The pairs will be
+processed in order by OPERATE."))
+  (define-convenience-action-methods traverse (operation component &key))
+
+  (defgeneric perform-plan (plan &key))
+  (defgeneric plan-operates-on-p (plan component))
+
+  (defparameter *default-plan-class* 'sequential-plan)
+
+  (defmethod traverse ((o operation) (c component) &rest keys &key plan-class &allow-other-keys)
+    (let ((plan (apply 'make-instance
+                       (or plan-class *default-plan-class*)
+                       :system (component-system c) (remove-plist-key :plan-class keys))))
+      (traverse-action plan o c t)
+      (plan-actions plan)))
+
+  (defmethod perform-plan :around (plan &key)
+    (declare (ignorable plan))
+    (let ((*package* *package*)
+          (*readtable* *readtable*))
+      (with-compilation-unit () ;; backward-compatibility.
+        (call-next-method))))   ;; Going forward, see deferred-warning support in lisp-build.
+
+  (defmethod perform-plan ((steps list) &key force &allow-other-keys)
+    (loop* :for (o . c) :in steps
+           :when (or force (not (nth-value 1 (compute-action-stamp nil o c))))
+           :do (perform-with-restarts o c)))
+
+  (defmethod plan-operates-on-p ((plan list) (component-path list))
+    (find component-path (mapcar 'cdr plan)
+          :test 'equal :key 'component-find-path)))
+
+
+;;;; Incidental traversals 
+(with-upgradability ()
+  (defclass filtered-sequential-plan (sequential-plan)
+    ((action-filter :initform t :initarg :action-filter :reader plan-action-filter)
+     (component-type :initform t :initarg :component-type :reader plan-component-type)
+     (keep-operation :initform t :initarg :keep-operation :reader plan-keep-operation)
+     (keep-component :initform t :initarg :keep-component :reader plan-keep-component)))
+
+  (defmethod initialize-instance :after ((plan filtered-sequential-plan)
+                                         &key (force () fp) (force-not () fnp)
+                                           other-systems)
+    (declare (ignore force force-not))
+    (with-slots (forced forced-not action-filter system) plan
+      (unless fp (setf forced (normalize-forced-systems (if other-systems :all t) system)))
+      (unless fnp (setf forced-not (normalize-forced-systems (if other-systems nil :all) system)))
+      (setf action-filter (ensure-function action-filter))))
+
+  (defmethod action-valid-p ((plan filtered-sequential-plan) o c)
+    (and (funcall (plan-action-filter plan) o c)
+         (typep c (plan-component-type plan))
+         (call-next-method)))
+
+  (defmethod traverse-actions (actions &rest keys &key plan-class &allow-other-keys)
+    (let ((plan (apply 'make-instance (or plan-class 'filtered-sequential-plan) keys)))
+      (loop* :for (o . c) :in actions :do
+             (traverse-action plan o c t))
+      (plan-actions plan)))
+
+  (define-convenience-action-methods traverse-sub-actions (o c &key))
+  (defmethod traverse-sub-actions ((operation operation) (component component) &rest keys &key &allow-other-keys)
+    (apply 'traverse-actions (direct-dependencies operation component)
+           :system (component-system component) keys))
+
+  (defmethod plan-actions ((plan filtered-sequential-plan))
+    (with-slots (keep-operation keep-component) plan
+      (loop* :for (o . c) :in (call-next-method)
+             :when (and (typep o keep-operation)
+                        (typep c keep-component))
+             :collect (cons o c))))
+
+  (defmethod required-components (system &rest keys &key (goal-operation 'load-op) &allow-other-keys)
+    (remove-duplicates
+     (mapcar 'cdr (apply 'traverse-sub-actions goal-operation system
+                         (remove-plist-key :goal-operation keys)))
+     :from-end t)))
 
 ;;;; -------------------------------------------------------------------------
 ;;;; Invoking Operations
 
-(defgeneric* operate (operation-class system &key &allow-other-keys))
-
-(defmethod operate (operation-class system &rest args
-                    &key ((:verbose *asdf-verbose*) *asdf-verbose*) version force
-                    &allow-other-keys)
-  (declare (ignore force))
-  (let* ((*package* *package*)
-         (*readtable* *readtable*)
-         (op (apply #'make-instance operation-class
-                    :original-initargs args
-                    args))
-         (*verbose-out* (if *asdf-verbose* *standard-output* (make-broadcast-stream)))
-         (system (if (typep system 'component) system (find-system system))))
-    (unless (version-satisfies system version)
-      (error 'missing-component-of-version :requires system :version version))
-    (let ((steps (traverse op system)))
-      (with-compilation-unit ()
-        (loop :for (op . component) :in steps :do
-          (loop
-            (restart-case
-                (progn
-                  (perform-with-restarts op component)
-                  (return))
-              (retry ()
-                :report
-                (lambda (s)
-                  (format s "~@<Retry ~A.~@:>" (operation-description op component))))
-              (accept ()
-                :report
-                (lambda (s)
-                  (format s "~@<Continue, treating ~A as having been successful.~@:>"
-                          (operation-description op component)))
-                (setf (gethash (type-of op)
-                               (component-operation-times component))
-                      (get-universal-time))
-                (return))))))
-      (values op steps))))
-
-(defun* oos (operation-class system &rest args &key force verbose version
-            &allow-other-keys)
-  (declare (ignore force verbose version))
-  (apply #'operate operation-class system args))
-
-(let ((operate-docstring
-  "Operate does three things:
-
-1. It creates an instance of OPERATION-CLASS using any keyword parameters
-as initargs.
-2. It finds the  asdf-system specified by SYSTEM (possibly loading
-it from disk).
+(asdf/package:define-package :asdf/operate
+  (:recycle :asdf/operate :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system :asdf/operation :asdf/action
+   :asdf/find-system :asdf/find-component :asdf/lisp-action :asdf/plan)
+  (:export
+   #:operate #:oos
+   #:*systems-being-operated*
+   #:build-system
+   #:load-system #:load-systems #:compile-system #:test-system #:require-system
+   #:*load-system-operation* #:module-provide-asdf
+   #:component-loaded-p #:already-loaded-systems))
+(in-package :asdf/operate)
+
+(with-upgradability ()
+  (defgeneric* (operate) (operation component &key &allow-other-keys)
+    (:documentation
+     "Operate does three things:
+
+1. It creates an instance of OPERATION-CLASS using any keyword parameters as initargs.
+2. It finds the  asdf-system specified by SYSTEM (possibly loading it from disk).
 3. It then calls TRAVERSE with the operation and system as arguments
 
-The traverse operation is wrapped in WITH-COMPILATION-UNIT and error
-handling code. If a VERSION argument is supplied, then operate also
-ensures that the system found satisfies it using the VERSION-SATISFIES
-method.
-
-Note that dependencies may cause the operation to invoke other
-operations on the system or its components: the new operations will be
-created with the same initargs as the original one.
-"))
+The traverse operation is wrapped in WITH-COMPILATION-UNIT and error handling code.
+If a VERSION argument is supplied, then operate also ensures that the system found
+satisfies it using the VERSION-SATISFIES method.
+
+Note that dependencies may cause the operation to invoke other operations on the system
+or its components: the new operations will be created with the same initargs as the original one.
+
+The :FORCE or :FORCE-NOT argument to OPERATE can be:
+  T to force the inside of the specified system to be rebuilt (resp. not),
+    without recursively forcing the other systems we depend on.
+  :ALL to force all systems including other systems we depend on to be rebuilt (resp. not).
+  (SYSTEM1 SYSTEM2 ... SYSTEMN) to force systems named in a given list
+:FORCE has precedence over :FORCE-NOT; builtin systems cannot be forced."))
+
+  (define-convenience-action-methods
+      operate (operation component &key)
+      ;; I'd like to at least remove-plist-keys :force :force-not :verbose,
+      ;; but swank.asd relies on :force (!).
+      :operation-initargs t ;; backward-compatibility with ASDF1. Yuck.
+      :if-no-component (error 'missing-component :requires component))
+
+  (defvar *systems-being-operated* nil
+    "A boolean indicating that some systems are being operated on")
+
+  (defmethod operate :around (operation component &rest keys
+                              &key verbose
+                                (on-warnings *compile-file-warnings-behaviour*)
+                                (on-failure *compile-file-failure-behaviour*) &allow-other-keys)
+    (declare (ignorable operation component))
+    (let* ((systems-being-operated *systems-being-operated*)
+           (*systems-being-operated* (or systems-being-operated (make-hash-table :test 'equal)))
+           (operation-name (reify-symbol (etypecase operation
+                                           (operation (type-of operation))
+                                           (symbol operation))))
+           (component-path (typecase component
+                             (component (component-find-path component))
+                             (t component))))
+      ;; Before we operate on any system, make sure ASDF is up-to-date,
+      ;; for if an upgrade is ever attempted at any later time, there may be BIG trouble.
+      (unless systems-being-operated
+        (when (upgrade-asdf)
+          ;; If we were upgraded, restart OPERATE the hardest of ways, for
+          ;; its function may have been redefined, its symbol uninterned, its package deleted.
+          (return-from operate
+            (apply (find-symbol* 'operate :asdf)
+                   (unreify-symbol operation-name)
+                   component-path keys))))
+      ;; Setup proper bindings around any operate call.
+      (with-system-definitions ()
+        (let* ((*verbose-out* (and verbose *standard-output*))
+               (*compile-file-warnings-behaviour* on-warnings)
+               (*compile-file-failure-behaviour* on-failure))
+          (call-next-method)))))
+
+  (defmethod operate :before ((operation operation) (component component)
+                              &key version &allow-other-keys)
+    (let ((system (component-system component)))
+      (setf (gethash (coerce-name system) *systems-being-operated*) system))
+    (unless (version-satisfies component version)
+      (error 'missing-component-of-version :requires component :version version)))
+
+  (defmethod operate ((operation operation) (component component)
+                      &rest keys &key &allow-other-keys)
+    (let ((plan (apply 'traverse operation component keys)))
+      (apply 'perform-plan plan keys)
+      (values operation plan)))
+
+  (defun oos (operation component &rest args &key &allow-other-keys)
+    (apply 'operate operation component args))
+
   (setf (documentation 'oos 'function)
-        (format nil
-                "Short for _operate on system_ and an alias for the OPERATE function. ~&~&~a"
-                operate-docstring))
-  (setf (documentation 'operate 'function)
-        operate-docstring))
-
-(defun* load-system (system &rest args &key force verbose version
-                    &allow-other-keys)
-  "Shorthand for `(operate 'asdf:load-op system)`. See OPERATE for
-details."
-  (declare (ignore force verbose version))
-  (apply #'operate 'load-op system args)
-  t)
-
-(defun* compile-system (system &rest args &key force verbose version
-                       &allow-other-keys)
-  "Shorthand for `(operate 'asdf:compile-op system)`. See OPERATE
-for details."
-  (declare (ignore force verbose version))
-  (apply #'operate 'compile-op system args)
-  t)
-
-(defun* test-system (system &rest args &key force verbose version
-                    &allow-other-keys)
-  "Shorthand for `(operate 'asdf:test-op system)`. See OPERATE for
-details."
-  (declare (ignore force verbose version))
-  (apply #'operate 'test-op system args)
-  t)
-
-;;;; -------------------------------------------------------------------------
-;;;; Defsystem
-
-(defun* load-pathname ()
-  (let ((pn (or *load-pathname* *compile-file-pathname*)))
-    (if *resolve-symlinks*
-        (and pn (resolve-symlinks pn))
-        pn)))
-
-(defun* determine-system-pathname (pathname pathname-supplied-p)
-  ;; The defsystem macro calls us to determine
-  ;; the pathname of a system as follows:
-  ;; 1. the one supplied,
-  ;; 2. derived from *load-pathname* via load-pathname
-  ;; 3. taken from the *default-pathname-defaults* via default-directory
-  (let* ((file-pathname (load-pathname))
-         (directory-pathname (and file-pathname (pathname-directory-pathname file-pathname))))
-    (or (and pathname-supplied-p (merge-pathnames* pathname directory-pathname))
-        directory-pathname
-        (default-directory))))
-
-(defmacro defsystem (name &body options)
-  (destructuring-bind (&key (pathname nil pathname-arg-p) (class 'system)
-                            defsystem-depends-on &allow-other-keys)
-      options
-    (let ((component-options (remove-keys '(:class) options)))
-      `(progn
-         ;; system must be registered before we parse the body, otherwise
-         ;; we recur when trying to find an existing system of the same name
-         ;; to reuse options (e.g. pathname) from
-         ,@(loop :for system :in defsystem-depends-on
-             :collect `(load-system ,system))
-         (let ((s (system-registered-p ',name)))
-           (cond ((and s (eq (type-of (cdr s)) ',class))
-                  (setf (car s) (get-universal-time)))
-                 (s
-                  (change-class (cdr s) ',class))
-                 (t
-                  (register-system (quote ,name)
-                                   (make-instance ',class :name ',name))))
-           (%set-system-source-file (load-pathname)
-                                    (cdr (system-registered-p ',name))))
-         (parse-component-form
-          nil (list*
-               :module (coerce-name ',name)
-               :pathname
-               ,(determine-system-pathname pathname pathname-arg-p)
-               ',component-options))))))
-
-(defun* class-for-type (parent type)
-  (or (loop :for symbol :in (list
-                             type
-                             (find-symbol* type *package*)
-                             (find-symbol* type :asdf))
-        :for class = (and symbol (find-class symbol nil))
-        :when (and class (subtypep class 'component))
-        :return class)
-      (and (eq type :file)
-           (or (module-default-component-class parent)
-               (find-class *default-component-class*)))
-      (sysdef-error "~@<don't recognize component type ~A~@:>" type)))
-
-(defun* maybe-add-tree (tree op1 op2 c)
-  "Add the node C at /OP1/OP2 in TREE, unless it's there already.
-Returns the new tree (which probably shares structure with the old one)"
-  (let ((first-op-tree (assoc op1 tree)))
-    (if first-op-tree
-        (progn
-          (aif (assoc op2 (cdr first-op-tree))
-               (if (find c (cdr it))
-                   nil
-                   (setf (cdr it) (cons c (cdr it))))
-               (setf (cdr first-op-tree)
-                     (acons op2 (list c) (cdr first-op-tree))))
-          tree)
-        (acons op1 (list (list op2 c)) tree))))
-
-(defun* union-of-dependencies (&rest deps)
-  (let ((new-tree nil))
-    (dolist (dep deps)
-      (dolist (op-tree dep)
-        (dolist (op  (cdr op-tree))
-          (dolist (c (cdr op))
-            (setf new-tree
-                  (maybe-add-tree new-tree (car op-tree) (car op) c))))))
-    new-tree))
-
-
-(defvar *serial-depends-on* nil)
-
-(defun* sysdef-error-component (msg type name value)
-  (sysdef-error (concatenate 'string msg
-                             "~&The value specified for ~(~A~) ~A is ~S")
-                type name value))
-
-(defun* check-component-input (type name weakly-depends-on
-                              depends-on components in-order-to)
-  "A partial test of the values of a component."
-  (unless (listp depends-on)
-    (sysdef-error-component ":depends-on must be a list."
-                            type name depends-on))
-  (unless (listp weakly-depends-on)
-    (sysdef-error-component ":weakly-depends-on must be a list."
-                            type name weakly-depends-on))
-  (unless (listp components)
-    (sysdef-error-component ":components must be NIL or a list of components."
-                            type name components))
-  (unless (and (listp in-order-to) (listp (car in-order-to)))
-    (sysdef-error-component ":in-order-to must be NIL or a list of components."
-                            type name in-order-to)))
-
-(defun* %remove-component-inline-methods (component)
-  (dolist (name +asdf-methods+)
-    (map ()
-         ;; this is inefficient as most of the stored
-         ;; methods will not be for this particular gf
-         ;; But this is hardly performance-critical
-         (lambda (m)
-           (remove-method (symbol-function name) m))
-         (component-inline-methods component)))
-  ;; clear methods, then add the new ones
-  (setf (component-inline-methods component) nil))
-
-(defun* %define-component-inline-methods (ret rest)
-  (dolist (name +asdf-methods+)
-    (let ((keyword (intern (symbol-name name) :keyword)))
-      (loop :for data = rest :then (cddr data)
-        :for key = (first data)
-        :for value = (second data)
-        :while data
-        :when (eq key keyword) :do
-        (destructuring-bind (op qual (o c) &body body) value
-          (pushnew
-           (eval `(defmethod ,name ,qual ((,o ,op) (,c (eql ,ret)))
-                             ,@body))
-           (component-inline-methods ret)))))))
-
-(defun* %refresh-component-inline-methods (component rest)
-  (%remove-component-inline-methods component)
-  (%define-component-inline-methods component rest))
-
-(defun* parse-component-form (parent options)
-  (destructuring-bind
-        (type name &rest rest &key
-              ;; the following list of keywords is reproduced below in the
-              ;; remove-keys form.  important to keep them in sync
-              components pathname default-component-class
-              perform explain output-files operation-done-p
-              weakly-depends-on
-              depends-on serial in-order-to
-              ;; list ends
-              &allow-other-keys) options
-    (declare (ignorable perform explain output-files operation-done-p))
-    (check-component-input type name weakly-depends-on depends-on components in-order-to)
-
-    (when (and parent
-               (find-component parent name)
-               ;; ignore the same object when rereading the defsystem
-               (not
-                (typep (find-component parent name)
-                       (class-for-type parent type))))
-      (error 'duplicate-names :name name))
-
-    (let* ((other-args (remove-keys
-                        '(components pathname default-component-class
-                          perform explain output-files operation-done-p
-                          weakly-depends-on
-                          depends-on serial in-order-to)
-                        rest))
-           (ret
-            (or (find-component parent name)
-                (make-instance (class-for-type parent type)))))
-      (when weakly-depends-on
-        (appendf depends-on (remove-if (complement #'find-system) weakly-depends-on)))
-      (when *serial-depends-on*
-        (push *serial-depends-on* depends-on))
-      (apply #'reinitialize-instance ret
-             :name (coerce-name name)
-             :pathname pathname
-             :parent parent
-             other-args)
-      (component-pathname ret) ; eagerly compute the absolute pathname
-      (when (typep ret 'module)
-        (setf (module-default-component-class ret)
-              (or default-component-class
-                  (and (typep parent 'module)
-                       (module-default-component-class parent))))
-        (let ((*serial-depends-on* nil))
-          (setf (module-components ret)
-                (loop
-                  :for c-form :in components
-                  :for c = (parse-component-form ret c-form)
-                  :for name = (component-name c)
-                  :collect c
-                  :when serial :do (setf *serial-depends-on* name))))
-        (compute-module-components-by-name ret))
-
-      (setf (component-load-dependencies ret) depends-on) ;; Used by POIU
-
-      (setf (component-in-order-to ret)
-            (union-of-dependencies
-             in-order-to
-             `((compile-op (compile-op ,@depends-on))
-               (load-op (load-op ,@depends-on)))))
-      (setf (component-do-first ret) `((compile-op (load-op ,@depends-on))))
-
-      (%refresh-component-inline-methods ret rest)
-      ret)))
+        (format nil "Short for _operate on system_ and an alias for the OPERATE function.~%~%~a"
+                (documentation 'operate 'function))))
+
+
+;;;; Common operations
+(with-upgradability ()
+  (defvar *load-system-operation* 'load-op
+    "Operation used by ASDF:LOAD-SYSTEM. By default, ASDF:LOAD-OP.
+You may override it with e.g. ASDF:LOAD-FASL-OP from asdf-bundle,
+or ASDF:LOAD-SOURCE-OP if your fasl loading is somehow broken.
+
+This may change in the future as we will implement component-based strategy
+for how to load or compile stuff")
+
+  (defun build-system (system &rest keys)
+    "Shorthand for `(operate 'asdf:build-op system)`."
+    (apply 'operate 'build-op system keys)
+    t)
+
+  (defun load-system (system &rest keys &key force force-not verbose version &allow-other-keys)
+    "Shorthand for `(operate 'asdf:load-op system)`. See OPERATE for details."
+    (declare (ignore force force-not verbose version))
+    (apply 'operate *load-system-operation* system keys)
+    t)
+
+  (defun load-systems (&rest systems)
+    "Loading multiple systems at once."
+    (map () 'load-system systems))
+
+  (defun compile-system (system &rest args &key force force-not verbose version &allow-other-keys)
+    "Shorthand for `(asdf:operate 'asdf:compile-op system)`. See OPERATE for details."
+    (declare (ignore force force-not verbose version))
+    (apply 'operate 'compile-op system args)
+    t)
+
+  (defun test-system (system &rest args &key force force-not verbose version &allow-other-keys)
+    "Shorthand for `(asdf:operate 'asdf:test-op system)`. See OPERATE for details."
+    (declare (ignore force force-not verbose version))
+    (apply 'operate 'test-op system args)
+    t))
+
+
+;;;; Define require-system, to be hooked into CL:REQUIRE when possible,
+;; i.e. for ABCL, CLISP, ClozureCL, CMUCL, ECL, MKCL and SBCL
+(with-upgradability ()
+  (defun component-loaded-p (c)
+    (action-already-done-p nil (make-instance 'load-op) (find-component c ())))
+
+  (defun already-loaded-systems ()
+    (remove-if-not 'component-loaded-p (registered-systems)))
+
+  (defun require-system (s &rest keys &key &allow-other-keys)
+    (apply 'load-system s :force-not (already-loaded-systems) keys))
+
+  (defvar *modules-being-required* nil)
+
+  (defclass require-system (system)
+    ((module :initarg :module :initform nil :accessor required-module)))
+
+  (defmethod perform ((o compile-op) (c require-system))
+    (declare (ignorable o c))
+    nil)
+
+  (defmethod perform ((o load-op) (s require-system))
+    (declare (ignorable o))
+    (let* ((module (or (required-module s) (coerce-name s)))
+           (*modules-being-required* (cons module *modules-being-required*)))
+      (assert (null (component-children s)))
+      (require module)))
+
+  (defmethod resolve-dependency-combination (component (combinator (eql :require)) arguments)
+    (declare (ignorable component combinator))
+    (unless (length=n-p arguments 1)
+      (error (compatfmt "~@<Bad dependency ~S for ~S. ~S takes only one argument~@:>")
+             (cons combinator arguments) component combinator))
+    (let* ((module (car arguments))
+           (name (string-downcase module))
+           (system (find-system name nil)))
+      (assert module)
+      ;;(unless (typep system '(or null require-system))
+      ;;  (warn "~S depends on ~S but ~S is registered as a ~S"
+      ;;        component (cons combinator arguments) module (type-of system)))
+      (or system (let ((system (make-instance 'require-system :name name)))
+                   (register-system system)
+                   system))))
+
+  (defun module-provide-asdf (name)
+    (let ((module (string-downcase name)))
+      (unless (member module *modules-being-required* :test 'equal)
+        (let ((*modules-being-required* (cons module *modules-being-required*))
+              #+sbcl (sb-impl::*requiring* (remove module sb-impl::*requiring* :test 'equal)))
+          (handler-bind
+              ((style-warning #'muffle-warning)
+               (missing-component (constantly nil))
+               (error #'(lambda (e)
+                          (format *error-output* (compatfmt "~@<ASDF could not load ~(~A~) because ~A.~@:>~%")
+                                  name e))))
+            (let ((*verbose-out* (make-broadcast-stream)))
+              (let ((system (find-system module nil)))
+                (when system
+                  (require-system system :verbose nil)
+                  t)))))))))
+
+
+;;;; Some upgrade magic
+(with-upgradability ()
+  (defun restart-upgraded-asdf ()
+    ;; If we're in the middle of something, restart it.
+    (when *systems-being-defined*
+      (let ((l (loop :for name :being :the :hash-keys :of *systems-being-defined* :collect name)))
+        (clrhash *systems-being-defined*)
+        (dolist (s l) (find-system s nil)))))
+
+  (register-hook-function '*post-upgrade-restart-hook* 'restart-upgraded-asdf))
+
 
 ;;;; ---------------------------------------------------------------------------
-;;;; run-shell-command
-;;;;
-;;;; run-shell-command functions for other lisp implementations will be
-;;;; gratefully accepted, if they do the same thing.
-;;;; If the docstring is ambiguous, send a bug report.
-;;;;
-;;;; We probably should move this functionality to its own system and deprecate
-;;;; use of it from the asdf package. However, this would break unspecified
-;;;; existing software, so until a clear alternative exists, we can't deprecate
-;;;; it, and even after it's been deprecated, we will support it for a few
-;;;; years so everyone has time to migrate away from it. -- fare 2009-12-01
-
-(defun* run-shell-command (control-string &rest args)
-  "Interpolate ARGS into CONTROL-STRING as if by FORMAT, and
-synchronously execute the result using a Bourne-compatible shell, with
-output to *VERBOSE-OUT*.  Returns the shell's exit code."
-  (let ((command (apply #'format nil control-string args)))
-    (asdf-message "; $ ~A~%" command)
-
-    #+abcl
-    (ext:run-shell-command command :output *verbose-out*)
-
-    #+allegro
-    ;; will this fail if command has embedded quotes - it seems to work
-    (multiple-value-bind (stdout stderr exit-code)
-        (excl.osi:command-output
-         (format nil "~a -c \"~a\""
-                 #+mswindows "sh" #-mswindows "/bin/sh" command)
-         :input nil :whole nil
-         #+mswindows :show-window #+mswindows :hide)
-      (asdf-message "~{~&; ~a~%~}~%" stderr)
-      (asdf-message "~{~&; ~a~%~}~%" stdout)
-      exit-code)
-
-    #+clisp                     ;XXX not exactly *verbose-out*, I know
-    (ext:run-shell-command  command :output :terminal :wait t)
-
-    #+clozure
-    (nth-value 1
-               (ccl:external-process-status
-                (ccl:run-program "/bin/sh" (list "-c" command)
-                                 :input nil :output *verbose-out*
-                                 :wait t)))
-
-    #+ecl ;; courtesy of Juan Jose Garcia Ripoll
-    (si:system command)
-
-    #+gcl
-    (lisp:system command)
-
-    #+lispworks
-    (system:call-system-showing-output
-     command
-     :shell-type "/bin/sh"
-     :show-cmd nil
-     :prefix ""
-     :output-stream *verbose-out*)
-
-    #+sbcl
-    (sb-ext:process-exit-code
-     (apply #'sb-ext:run-program
-            #+win32 "sh" #-win32 "/bin/sh"
-            (list  "-c" command)
-            :input nil :output *verbose-out*
-            #+win32 '(:search t) #-win32 nil))
-
-    #+(or cmu scl)
-    (ext:process-exit-code
-     (ext:run-program
-      "/bin/sh"
-      (list  "-c" command)
-      :input nil :output *verbose-out*))
-
-    #-(or abcl allegro clisp clozure cmu ecl gcl lispworks sbcl scl)
-    (error "RUN-SHELL-COMMAND not implemented for this Lisp")))
-
-;;;; ---------------------------------------------------------------------------
-;;;; system-relative-pathname
-
-(defmethod system-source-file ((system-name string))
-  (system-source-file (find-system system-name)))
-(defmethod system-source-file ((system-name symbol))
-  (system-source-file (find-system system-name)))
-
-(defun* system-source-directory (system-designator)
-  "Return a pathname object corresponding to the
-directory in which the system specification (.asd file) is
-located."
-     (make-pathname :name nil
-                 :type nil
-                 :defaults (system-source-file system-designator)))
-
-(defun* relativize-directory (directory)
-  (cond
-    ((stringp directory)
-     (list :relative directory))
-    ((eq (car directory) :absolute)
-     (cons :relative (cdr directory)))
-    (t
-     directory)))
-
-(defun* relativize-pathname-directory (pathspec)
-  (let ((p (pathname pathspec)))
-    (make-pathname
-     :directory (relativize-directory (pathname-directory p))
-     :defaults p)))
-
-(defun* system-relative-pathname (system name &key type)
-  (merge-pathnames*
-   (merge-component-name-type name :type type)
-   (system-source-directory system)))
-
-
-;;; ---------------------------------------------------------------------------
-;;; implementation-identifier
-;;;
-;;; produce a string to identify current implementation.
-;;; Initially stolen from SLIME's SWANK, hacked since.
-
-(defparameter *implementation-features*
-  '((:acl :allegro)
-    (:lw :lispworks)
-    (:digitool) ; before clozure, so it won't get preempted by ccl
-    (:ccl :clozure)
-    (:corman :cormanlisp)
-    (:abcl :armedbear)
-    :sbcl :cmu :clisp :gcl :ecl :scl))
-
-(defparameter *os-features*
-  '((:win :windows :mswindows :win32 :mingw32) ;; shorten things on windows
-    (:solaris :sunos)
-    (:linux :linux-target) ;; for GCL at least, must appear before :bsd.
-    (:macosx :darwin :darwin-target :apple)
-    :freebsd :netbsd :openbsd :bsd
-    :unix))
-
-(defparameter *architecture-features*
-  '((:amd64 :x86-64 :x86_64 :x8664-target)
-    (:x86 :i386 :i486 :i586 :i686 :pentium3 :pentium4 :pc386 :iapx386 :x8632-target)
-    :hppa64
-    :hppa
-    (:ppc64 :ppc64-target)
-    (:ppc32 :ppc32-target :ppc :powerpc)
-    :sparc64
-    (:sparc32 :sparc)
-    (:arm :arm-target)
-    (:java :java-1.4 :java-1.5 :java-1.6 :java-1.7)))
-
-(defun* lisp-version-string ()
-  (let ((s (lisp-implementation-version)))
-    (declare (ignorable s))
-    #+allegro (format nil
-                      "~A~A~A~A"
-                      excl::*common-lisp-version-number*
-                      ;; ANSI vs MoDeRn - thanks to Robert Goldman and Charley Cox
-                      (if (eq excl:*current-case-mode*
-                              :case-sensitive-lower) "M" "A")
-                      ;; Note if not using International ACL
-                      ;; see http://www.franz.com/support/documentation/8.1/doc/operators/excl/ics-target-case.htm
-                      (excl:ics-target-case
-                       (:-ics "8")
-                       (:+ics ""))
-                      (if (member :64bit *features*) "-64bit" ""))
-    #+armedbear (format nil "~a-fasl~a" s system::*fasl-version*)
-    #+clisp (subseq s 0 (position #\space s))
-    #+clozure (format nil "~d.~d-f~d" ; shorten for windows
-                      ccl::*openmcl-major-version*
-                      ccl::*openmcl-minor-version*
-                      (logand ccl::fasl-version #xFF))
-    #+cmu (substitute #\- #\/ s)
-    #+digitool (subseq s 8)
-    #+ecl (format nil "~A~@[-~A~]" s
-                  (let ((vcs-id (ext:lisp-implementation-vcs-id)))
-                    (when (>= (length vcs-id) 8)
-                      (subseq vcs-id 0 8))))
-    #+gcl (subseq s (1+ (position #\space s)))
-    #+lispworks (format nil "~A~@[~A~]" s
-                        (when (member :lispworks-64bit *features*) "-64bit"))
-    ;; #+sbcl (format nil "~a-fasl~d" s sb-fasl:+fasl-file-version+) ; f-f-v redundant w/ version
-    #+(or cormanlisp mcl sbcl scl) s
-    #-(or allegro armedbear clisp clozure cmu cormanlisp digitool
-          ecl gcl lispworks mcl sbcl scl) s))
-
-(defun* first-feature (features)
-  (labels
-      ((fp (thing)
-         (etypecase thing
-           (symbol
-            (let ((feature (find thing *features*)))
-              (when feature (return-from fp feature))))
-           ;; allows features to be lists of which the first
-           ;; member is the "main name", the rest being aliases
-           (cons
-            (dolist (subf thing)
-              (when (find subf *features*) (return-from fp (first thing))))))
-         nil))
-    (loop :for f :in features
-      :when (fp f) :return :it)))
-
-(defun* implementation-type ()
-  (first-feature *implementation-features*))
-
-(defun* implementation-identifier ()
-  (labels
-      ((maybe-warn (value fstring &rest args)
-         (cond (value)
-               (t (apply #'warn fstring args)
-                  "unknown"))))
-    (let ((lisp (maybe-warn (implementation-type)
-                            "No implementation feature found in ~a."
-                            *implementation-features*))
-          (os   (maybe-warn (first-feature *os-features*)
-                            "No os feature found in ~a." *os-features*))
-          (arch (maybe-warn (first-feature *architecture-features*)
-                            "No architecture feature found in ~a."
-                            *architecture-features*))
-          (version (maybe-warn (lisp-version-string)
-                               "Don't know how to get Lisp implementation version.")))
-      (substitute-if
-       #\_ (lambda (x) (find x " /:\\(){}[]$#`'\""))
-       (format nil "~(~@{~a~^-~}~)" lisp version os arch)))))
-
-
-
-;;; ---------------------------------------------------------------------------
-;;; Generic support for configuration files
-
-(defparameter *inter-directory-separator*
-  #+(or unix cygwin) #\:
-  #-(or unix cygwin) #\;)
-
-(defun* user-homedir ()
-  (truename (user-homedir-pathname)))
-
-(defun* try-directory-subpath (x sub &key type)
-  (let* ((p (and x (ensure-directory-pathname x)))
-         (tp (and p (probe-file* p)))
-         (sp (and tp (merge-pathnames* (merge-component-name-type sub :type type) p)))
-         (ts (and sp (probe-file* sp))))
-    (and ts (values sp ts))))
-(defun* user-configuration-directories ()
-  (remove-if
-   #'null
-   (flet ((try (x sub) (try-directory-subpath x sub :type :directory)))
-     `(,(try (getenv "XDG_CONFIG_HOME") "common-lisp/")
-       ,@(loop :with dirs = (getenv "XDG_CONFIG_DIRS")
-           :for dir :in (split-string dirs :separator ":")
-           :collect (try dir "common-lisp/"))
-       #+(and (or win32 windows mswindows mingw32) (not cygwin))
-        ,@`(#+lispworks ,(try (sys:get-folder-path :common-appdata) "common-lisp/config/")
-            ;;; read-windows-registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\AppData
-           ,(try (getenv "APPDATA") "common-lisp/config/"))
-       ,(try (user-homedir) ".config/common-lisp/")))))
-(defun* system-configuration-directories ()
-  (remove-if
-   #'null
-   (append
-    #+(and (or win32 windows mswindows mingw32) (not cygwin))
-    (flet ((try (x sub) (try-directory-subpath x sub :type :directory)))
-      `(,@`(#+lispworks ,(try (sys:get-folder-path :local-appdata) "common-lisp/config/")
-           ;;; read-windows-registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\Common AppData
-        ,(try (getenv "ALLUSERSPROFILE") "Application Data/common-lisp/config/"))))
-    (list #p"/etc/common-lisp/"))))
-(defun* in-first-directory (dirs x)
-  (loop :for dir :in dirs
-    :thereis (and dir (probe-file* (merge-pathnames* x (ensure-directory-pathname dir))))))
-(defun* in-user-configuration-directory (x)
-  (in-first-directory (user-configuration-directories) x))
-(defun* in-system-configuration-directory (x)
-  (in-first-directory (system-configuration-directories) x))
-
-(defun* configuration-inheritance-directive-p (x)
-  (let ((kw '(:inherit-configuration :ignore-inherited-configuration)))
-    (or (member x kw)
-        (and (length=n-p x 1) (member (car x) kw)))))
-
-(defun* validate-configuration-form (form tag directive-validator
-                                    &optional (description tag))
-  (unless (and (consp form) (eq (car form) tag))
-    (error "Error: Form doesn't specify ~A ~S~%" description form))
-  (loop :with inherit = 0
-    :for directive :in (cdr form) :do
-    (if (configuration-inheritance-directive-p directive)
-        (incf inherit)
-        (funcall directive-validator directive))
-    :finally
-    (unless (= inherit 1)
-      (error "One and only one of ~S or ~S is required"
-             :inherit-configuration :ignore-inherited-configuration)))
-  form)
-
-(defun* validate-configuration-file (file validator description)
-  (let ((forms (read-file-forms file)))
-    (unless (length=n-p forms 1)
-      (error "One and only one form allowed for ~A. Got: ~S~%" description forms))
-    (funcall validator (car forms))))
-
-(defun* hidden-file-p (pathname)
-  (equal (first-char (pathname-name pathname)) #\.))
-
-(defun* validate-configuration-directory (directory tag validator)
-  (let ((files (sort (ignore-errors
-                       (remove-if
-                        'hidden-file-p
-                        (directory (make-pathname :name :wild :type "conf" :defaults directory)
-                                   #+sbcl :resolve-symlinks #+sbcl nil)))
-                     #'string< :key #'namestring)))
-    `(,tag
-      ,@(loop :for file :in files :append
-          (mapcar validator (read-file-forms file)))
-      :inherit-configuration)))
-
-
-;;; ---------------------------------------------------------------------------
-;;; asdf-output-translations
-;;;
-;;; this code is heavily inspired from
-;;; asdf-binary-translations, common-lisp-controller and cl-launch.
-;;; ---------------------------------------------------------------------------
-
-(defvar *output-translations* ()
-  "Either NIL (for uninitialized), or a list of one element,
+;;;; asdf-output-translations
+
+(asdf/package:define-package :asdf/output-translations
+  (:recycle :asdf/output-translations :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade)
+  (:export
+   #:*output-translations* #:*output-translations-parameter*
+   #:invalid-output-translation
+   #:output-translations #:output-translations-initialized-p
+   #:initialize-output-translations #:clear-output-translations
+   #:disable-output-translations #:ensure-output-translations
+   #:apply-output-translations
+   #:validate-output-translations-directive #:validate-output-translations-form
+   #:validate-output-translations-file #:validate-output-translations-directory
+   #:parse-output-translations-string #:wrapping-output-translations
+   #:user-output-translations-pathname #:system-output-translations-pathname
+   #:user-output-translations-directory-pathname #:system-output-translations-directory-pathname
+   #:environment-output-translations #:process-output-translations
+   #:compute-output-translations
+   #+abcl #:translate-jar-pathname
+   ))
+(in-package :asdf/output-translations)
+
+(when-upgrading () (undefine-function '(setf output-translations)))
+
+(with-upgradability ()
+  (define-condition invalid-output-translation (invalid-configuration warning)
+    ((format :initform (compatfmt "~@<Invalid asdf output-translation ~S~@[ in ~S~]~@{ ~@?~}~@:>"))))
+
+  (defvar *output-translations* ()
+    "Either NIL (for uninitialized), or a list of one element,
 said element itself being a sorted list of mappings.
 Each mapping is a pair of a source pathname and destination pathname,
 and the order is by decreasing length of namestring of the source pathname.")
 
-(defvar *user-cache*
-  (flet ((try (x &rest sub) (and x `(,x ,@sub))))
-    (or
-     (try (getenv "XDG_CACHE_HOME") "common-lisp" :implementation)
-     #+(and (or win32 windows mswindows mingw32) (not cygwin))
-     (try (getenv "APPDATA") "common-lisp" "cache" :implementation)
-     '(:home ".cache" "common-lisp" :implementation))))
-(defvar *system-cache*
-  ;; No good default, plus there's a security problem
-  ;; with other users messing with such directories.
-  *user-cache*)
-
-(defun* output-translations ()
-  (car *output-translations*))
-
-(defun* (setf output-translations) (new-value)
-  (setf *output-translations*
-        (list
-         (stable-sort (copy-list new-value) #'>
-                      :key (lambda (x)
-                             (etypecase (car x)
-                               ((eql t) -1)
-                               (pathname
-                                (length (pathname-directory (car x)))))))))
-  new-value)
-
-(defun* output-translations-initialized-p ()
-  (and *output-translations* t))
-
-(defun* clear-output-translations ()
-  "Undoes any initialization of the output translations.
-You might want to call that before you dump an image that would be resumed
-with a different configuration, so the configuration would be re-read then."
-  (setf *output-translations* '())
-  (values))
-
-(declaim (ftype (function (t &key (:directory boolean) (:wilden boolean))
-                          (values (or null pathname) &optional))
-                resolve-location))
-
-(defun* resolve-relative-location-component (super x &key directory wilden)
-  (let* ((r (etypecase x
-              (pathname x)
-              (string x)
-              (cons
-               (return-from resolve-relative-location-component
-                 (if (null (cdr x))
-                     (resolve-relative-location-component
-                      super (car x) :directory directory :wilden wilden)
-                     (let* ((car (resolve-relative-location-component
-                                  super (car x) :directory t :wilden nil))
-                            (cdr (resolve-relative-location-component
-                                  (merge-pathnames* car super) (cdr x)
-                                  :directory directory :wilden wilden)))
-                       (merge-pathnames* cdr car)))))
-              ((eql :default-directory)
-               (relativize-pathname-directory (default-directory)))
-              ((eql :implementation) (implementation-identifier))
-              ((eql :implementation-type) (string-downcase (implementation-type)))
-              #-(and (or win32 windows mswindows mingw32) (not cygwin))
-              ((eql :uid) (princ-to-string (get-uid)))))
-         (d (if (or (pathnamep x) (not directory)) r (ensure-directory-pathname r)))
-         (s (if (or (pathnamep x) (not wilden)) d (wilden d))))
-    (when (and (absolute-pathname-p s) (not (pathname-match-p s (wilden super))))
-      (error "pathname ~S is not relative to ~S" s super))
-    (merge-pathnames* s super)))
-
-(defun* resolve-absolute-location-component (x &key directory wilden)
-  (let* ((r
-          (etypecase x
-            (pathname x)
-            (string (if directory (ensure-directory-pathname x) (parse-namestring x)))
-            (cons
-             (return-from resolve-absolute-location-component
-               (if (null (cdr x))
-                   (resolve-absolute-location-component
-                    (car x) :directory directory :wilden wilden)
-                   (let* ((car (resolve-absolute-location-component
-                                (car x) :directory t :wilden nil))
-                          (cdr (resolve-relative-location-component
-                                car (cdr x) :directory directory :wilden wilden)))
-                     (merge-pathnames* cdr car))))) ; XXX why is this not just "cdr" ?
-            ((eql :root)
-             ;; special magic! we encode such paths as relative pathnames,
-             ;; but it means "relative to the root of the source pathname's host and device".
-             (return-from resolve-absolute-location-component
-               (let ((p (make-pathname :directory '(:relative))))
-                 (if wilden (wilden p) p))))
-            ((eql :home) (user-homedir))
-            ((eql :user-cache) (resolve-location *user-cache* :directory t :wilden nil))
-            ((eql :system-cache) (resolve-location *system-cache* :directory t :wilden nil))
-            ((eql :default-directory) (default-directory))))
-         (s (if (and wilden (not (pathnamep x)))
-                (wilden r)
-                r)))
-    (unless (absolute-pathname-p s)
-      (error "Not an absolute pathname ~S" s))
-    s))
-
-(defun* resolve-location (x &key directory wilden)
-  (if (atom x)
-      (resolve-absolute-location-component x :directory directory :wilden wilden)
-      (loop :with path = (resolve-absolute-location-component
-                          (car x) :directory (and (or directory (cdr x)) t)
-                          :wilden (and wilden (null (cdr x))))
-        :for (component . morep) :on (cdr x)
-        :for dir = (and (or morep directory) t)
-        :for wild = (and wilden (not morep))
-        :do (setf path (resolve-relative-location-component
-                        path component :directory dir :wilden wild))
-        :finally (return path))))
-
-(defun* location-designator-p (x)
-  (flet ((componentp (c) (typep c '(or string pathname keyword))))
-    (or (typep x 'boolean) (componentp x) (and (consp x) (every #'componentp x)))))
-
-(defun* location-function-p (x)
-  (and
-   (consp x)
-   (length=n-p x 2)
-   (or (and (equal (first x) :function)
-            (typep (second x) 'symbol))
-       (and (equal (first x) 'lambda)
-            (cddr x)
-            (length=n-p (second x) 2)))))
-
-(defun* validate-output-translations-directive (directive)
-  (unless
-      (or (member directive '(:inherit-configuration
-                              :ignore-inherited-configuration
-                              :enable-user-cache :disable-cache nil))
-          (and (consp directive)
-               (or (and (length=n-p directive 2)
-                        (or (and (eq (first directive) :include)
-                                 (typep (second directive) '(or string pathname null)))
-                            (and (location-designator-p (first directive))
-                                 (or (location-designator-p (second directive))
-                                     (location-function-p (second directive))))))
-                   (and (length=n-p directive 1)
-                        (location-designator-p (first directive))))))
-    (error "Invalid directive ~S~%" directive))
-  directive)
-
-(defun* validate-output-translations-form (form)
-  (validate-configuration-form
-   form
-   :output-translations
-   'validate-output-translations-directive
-   "output translations"))
-
-(defun* validate-output-translations-file (file)
-  (validate-configuration-file
-   file 'validate-output-translations-form "output translations"))
-
-(defun* validate-output-translations-directory (directory)
-  (validate-configuration-directory
-   directory :output-translations 'validate-output-translations-directive))
-
-(defun* parse-output-translations-string (string)
-  (cond
-    ((or (null string) (equal string ""))
-     '(:output-translations :inherit-configuration))
-    ((not (stringp string))
-     (error "environment string isn't: ~S" string))
-    ((eql (char string 0) #\")
-     (parse-output-translations-string (read-from-string string)))
-    ((eql (char string 0) #\()
-     (validate-output-translations-form (read-from-string string)))
-    (t
-     (loop
-      :with inherit = nil
-      :with directives = ()
-      :with start = 0
-      :with end = (length string)
-      :with source = nil
-      :for i = (or (position *inter-directory-separator* string :start start) end) :do
-      (let ((s (subseq string start i)))
-        (cond
-          (source
-           (push (list source (if (equal "" s) nil s)) directives)
-           (setf source nil))
-          ((equal "" s)
-           (when inherit
-             (error "only one inherited configuration allowed: ~S" string))
-           (setf inherit t)
-           (push :inherit-configuration directives))
-          (t
-           (setf source s)))
-        (setf start (1+ i))
-        (when (> start end)
-          (when source
-            (error "Uneven number of components in source to destination mapping ~S" string))
-          (unless inherit
-            (push :ignore-inherited-configuration directives))
-          (return `(:output-translations ,@(nreverse directives)))))))))
-
-(defparameter *default-output-translations*
-  '(environment-output-translations
-    user-output-translations-pathname
-    user-output-translations-directory-pathname
-    system-output-translations-pathname
-    system-output-translations-directory-pathname))
-
-(defun* wrapping-output-translations ()
-  `(:output-translations
+  (defun output-translations ()
+    (car *output-translations*))
+
+  (defun set-output-translations (new-value)
+    (setf *output-translations*
+          (list
+           (stable-sort (copy-list new-value) #'>
+                        :key #'(lambda (x)
+                                 (etypecase (car x)
+                                   ((eql t) -1)
+                                   (pathname
+                                    (let ((directory (pathname-directory (car x))))
+                                      (if (listp directory) (length directory) 0))))))))
+    new-value)
+  #-gcl2.6
+  (defun* ((setf output-translations)) (new-value) (set-output-translations new-value))
+  #+gcl2.6
+  (defsetf output-translations set-output-translations)
+
+  (defun output-translations-initialized-p ()
+    (and *output-translations* t))
+
+  (defun clear-output-translations ()
+    "Undoes any initialization of the output translations."
+    (setf *output-translations* '())
+    (values))
+  (register-clear-configuration-hook 'clear-output-translations)
+
+  (defun validate-output-translations-directive (directive)
+    (or (member directive '(:enable-user-cache :disable-cache nil))
+        (and (consp directive)
+             (or (and (length=n-p directive 2)
+                      (or (and (eq (first directive) :include)
+                               (typep (second directive) '(or string pathname null)))
+                          (and (location-designator-p (first directive))
+                               (or (location-designator-p (second directive))
+                                   (location-function-p (second directive))))))
+                 (and (length=n-p directive 1)
+                      (location-designator-p (first directive)))))))
+
+  (defun validate-output-translations-form (form &key location)
+    (validate-configuration-form
+     form
+     :output-translations
+     'validate-output-translations-directive
+     :location location :invalid-form-reporter 'invalid-output-translation))
+
+  (defun validate-output-translations-file (file)
+    (validate-configuration-file
+     file 'validate-output-translations-form :description "output translations"))
+
+  (defun validate-output-translations-directory (directory)
+    (validate-configuration-directory
+     directory :output-translations 'validate-output-translations-directive
+               :invalid-form-reporter 'invalid-output-translation))
+
+  (defun parse-output-translations-string (string &key location)
+    (cond
+      ((or (null string) (equal string ""))
+       '(:output-translations :inherit-configuration))
+      ((not (stringp string))
+       (error (compatfmt "~@<Environment string isn't: ~3i~_~S~@:>") string))
+      ((eql (char string 0) #\")
+       (parse-output-translations-string (read-from-string string) :location location))
+      ((eql (char string 0) #\()
+       (validate-output-translations-form (read-from-string string) :location location))
+      (t
+       (loop
+         :with inherit = nil
+         :with directives = ()
+         :with start = 0
+         :with end = (length string)
+         :with source = nil
+         :with separator = (inter-directory-separator)
+         :for i = (or (position separator string :start start) end) :do
+           (let ((s (subseq string start i)))
+             (cond
+               (source
+                (push (list source (if (equal "" s) nil s)) directives)
+                (setf source nil))
+               ((equal "" s)
+                (when inherit
+                  (error (compatfmt "~@<Only one inherited configuration allowed: ~3i~_~S~@:>")
+                         string))
+                (setf inherit t)
+                (push :inherit-configuration directives))
+               (t
+                (setf source s)))
+             (setf start (1+ i))
+             (when (> start end)
+               (when source
+                 (error (compatfmt "~@<Uneven number of components in source to destination mapping: ~3i~_~S~@:>")
+                        string))
+               (unless inherit
+                 (push :ignore-inherited-configuration directives))
+               (return `(:output-translations ,@(nreverse directives)))))))))
+
+  (defparameter *default-output-translations*
+    '(environment-output-translations
+      user-output-translations-pathname
+      user-output-translations-directory-pathname
+      system-output-translations-pathname
+      system-output-translations-directory-pathname))
+
+  (defun wrapping-output-translations ()
+    `(:output-translations
     ;; Some implementations have precompiled ASDF systems,
     ;; so we must disable translations for implementation paths.
-    #+sbcl ,(let ((h (getenv "SBCL_HOME"))) (when (plusp (length h)) `(,h ())))
-    #+ecl (,(translate-logical-pathname "SYS:**;*.*") ()) ; not needed: no precompiled ASDF system
-    #+clozure ,(ignore-errors (list (wilden (let ((*default-pathname-defaults* #p"")) (truename #p"ccl:"))) ())) ; not needed: no precompiled ASDF system
-    ;; All-import, here is where we want user stuff to be:
-    :inherit-configuration
-    ;; These are for convenience, and can be overridden by the user:
-    #+abcl (#p"/___jar___file___root___/**/*.*" (:user-cache #p"**/*.*"))
-    #+abcl (#p"jar:file:/**/*.jar!/**/*.*" (:function translate-jar-pathname))
-    ;; We enable the user cache by default, and here is the place we do:
-    :enable-user-cache))
-
-(defparameter *output-translations-file* #p"asdf-output-translations.conf")
-(defparameter *output-translations-directory* #p"asdf-output-translations.conf.d/")
-
-(defun* user-output-translations-pathname ()
-  (in-user-configuration-directory *output-translations-file* ))
-(defun* system-output-translations-pathname ()
-  (in-system-configuration-directory *output-translations-file*))
-(defun* user-output-translations-directory-pathname ()
-  (in-user-configuration-directory *output-translations-directory*))
-(defun* system-output-translations-directory-pathname ()
-  (in-system-configuration-directory *output-translations-directory*))
-(defun* environment-output-translations ()
-  (getenv "ASDF_OUTPUT_TRANSLATIONS"))
-
-(defgeneric* process-output-translations (spec &key inherit collect))
-(declaim (ftype (function (t &key (:collect (or symbol function))) t)
-                inherit-output-translations))
-(declaim (ftype (function (t &key (:collect (or symbol function)) (:inherit list)) t)
-                process-output-translations-directive))
-
-(defmethod process-output-translations ((x symbol) &key
-                                        (inherit *default-output-translations*)
-                                        collect)
-  (process-output-translations (funcall x) :inherit inherit :collect collect))
-(defmethod process-output-translations ((pathname pathname) &key inherit collect)
-  (cond
-    ((directory-pathname-p pathname)
-     (process-output-translations (validate-output-translations-directory pathname)
-                                  :inherit inherit :collect collect))
-    ((probe-file pathname)
-     (process-output-translations (validate-output-translations-file pathname)
-                                  :inherit inherit :collect collect))
-    (t
-     (inherit-output-translations inherit :collect collect))))
-(defmethod process-output-translations ((string string) &key inherit collect)
-  (process-output-translations (parse-output-translations-string string)
-                               :inherit inherit :collect collect))
-(defmethod process-output-translations ((x null) &key inherit collect)
-  (declare (ignorable x))
-  (inherit-output-translations inherit :collect collect))
-(defmethod process-output-translations ((form cons) &key inherit collect)
-  (dolist (directive (cdr (validate-output-translations-form form)))
-    (process-output-translations-directive directive :inherit inherit :collect collect)))
-
-(defun* inherit-output-translations (inherit &key collect)
-  (when inherit
-    (process-output-translations (first inherit) :collect collect :inherit (rest inherit))))
-
-(defun* process-output-translations-directive (directive &key inherit collect)
-  (if (atom directive)
-      (ecase directive
-        ((:enable-user-cache)
-         (process-output-translations-directive '(t :user-cache) :collect collect))
-        ((:disable-cache)
-         (process-output-translations-directive '(t t) :collect collect))
+      #+(or #|clozure|# ecl mkcl sbcl)
+      ,@(let ((h (resolve-symlinks* (lisp-implementation-directory))))
+          (when h `(((,h ,*wild-path*) ()))))
+      #+mkcl (,(translate-logical-pathname "CONTRIB:") ())
+      ;; All-import, here is where we want user stuff to be:
+      :inherit-configuration
+      ;; These are for convenience, and can be overridden by the user:
+      #+abcl (#p"/___jar___file___root___/**/*.*" (:user-cache #p"**/*.*"))
+      #+abcl (#p"jar:file:/**/*.jar!/**/*.*" (:function translate-jar-pathname))
+      ;; We enable the user cache by default, and here is the place we do:
+      :enable-user-cache))
+
+  (defparameter *output-translations-file* (parse-unix-namestring "asdf-output-translations.conf"))
+  (defparameter *output-translations-directory* (parse-unix-namestring "asdf-output-translations.conf.d/"))
+
+  (defun user-output-translations-pathname (&key (direction :input))
+    (in-user-configuration-directory *output-translations-file* :direction direction))
+  (defun system-output-translations-pathname (&key (direction :input))
+    (in-system-configuration-directory *output-translations-file* :direction direction))
+  (defun user-output-translations-directory-pathname (&key (direction :input))
+    (in-user-configuration-directory *output-translations-directory* :direction direction))
+  (defun system-output-translations-directory-pathname (&key (direction :input))
+    (in-system-configuration-directory *output-translations-directory* :direction direction))
+  (defun environment-output-translations ()
+    (getenv "ASDF_OUTPUT_TRANSLATIONS"))
+
+  (defgeneric process-output-translations (spec &key inherit collect))
+
+  (defun inherit-output-translations (inherit &key collect)
+    (when inherit
+      (process-output-translations (first inherit) :collect collect :inherit (rest inherit))))
+
+  (defun* (process-output-translations-directive) (directive &key inherit collect)
+    (if (atom directive)
+        (ecase directive
+          ((:enable-user-cache)
+           (process-output-translations-directive '(t :user-cache) :collect collect))
+          ((:disable-cache)
+           (process-output-translations-directive '(t t) :collect collect))
+          ((:inherit-configuration)
+           (inherit-output-translations inherit :collect collect))
+          ((:ignore-inherited-configuration :ignore-invalid-entries nil)
+           nil))
+        (let ((src (first directive))
+              (dst (second directive)))
+          (if (eq src :include)
+              (when dst
+                (process-output-translations (pathname dst) :inherit nil :collect collect))
+              (when src
+                (let ((trusrc (or (eql src t)
+                                  (let ((loc (resolve-location src :ensure-directory t :wilden t)))
+                                    (if (absolute-pathname-p loc) (resolve-symlinks* loc) loc)))))
+                  (cond
+                    ((location-function-p dst)
+                     (funcall collect
+                              (list trusrc
+                                    (if (symbolp (second dst))
+                                        (fdefinition (second dst))
+                                        (eval (second dst))))))
+                    ((eq dst t)
+                     (funcall collect (list trusrc t)))
+                    (t
+                     (let* ((trudst (if dst
+                                        (resolve-location dst :ensure-directory t :wilden t)
+                                        trusrc)))
+                       (funcall collect (list trudst t))
+                       (funcall collect (list trusrc trudst)))))))))))
+
+  (defmethod process-output-translations ((x symbol) &key
+                                                       (inherit *default-output-translations*)
+                                                       collect)
+    (process-output-translations (funcall x) :inherit inherit :collect collect))
+  (defmethod process-output-translations ((pathname #-gcl2.6 pathname #+gcl2.6 t) &key inherit collect)
+    (cond
+      ((directory-pathname-p pathname)
+       (process-output-translations (validate-output-translations-directory pathname)
+                                    :inherit inherit :collect collect))
+      ((probe-file* pathname :truename *resolve-symlinks*)
+       (process-output-translations (validate-output-translations-file pathname)
+                                    :inherit inherit :collect collect))
+      (t
+       (inherit-output-translations inherit :collect collect))))
+  (defmethod process-output-translations ((string string) &key inherit collect)
+    (process-output-translations (parse-output-translations-string string)
+                                 :inherit inherit :collect collect))
+  (defmethod process-output-translations ((x null) &key inherit collect)
+    (declare (ignorable x))
+    (inherit-output-translations inherit :collect collect))
+  (defmethod process-output-translations ((form cons) &key inherit collect)
+    (dolist (directive (cdr (validate-output-translations-form form)))
+      (process-output-translations-directive directive :inherit inherit :collect collect)))
+
+  (defun compute-output-translations (&optional parameter)
+    "read the configuration, return it"
+    (remove-duplicates
+     (while-collecting (c)
+       (inherit-output-translations
+        `(wrapping-output-translations ,parameter ,@*default-output-translations*) :collect #'c))
+     :test 'equal :from-end t))
+
+  (defvar *output-translations-parameter* nil)
+
+  (defun initialize-output-translations (&optional (parameter *output-translations-parameter*))
+    "read the configuration, initialize the internal configuration variable,
+return the configuration"
+    (setf *output-translations-parameter* parameter
+          (output-translations) (compute-output-translations parameter)))
+
+  (defun disable-output-translations ()
+    "Initialize output translations in a way that maps every file to itself,
+effectively disabling the output translation facility."
+    (initialize-output-translations
+     '(:output-translations :disable-cache :ignore-inherited-configuration)))
+
+  ;; checks an initial variable to see whether the state is initialized
+  ;; or cleared. In the former case, return current configuration; in
+  ;; the latter, initialize.  ASDF will call this function at the start
+  ;; of (asdf:find-system).
+  (defun ensure-output-translations ()
+    (if (output-translations-initialized-p)
+        (output-translations)
+        (initialize-output-translations)))
+
+  (defun* (apply-output-translations) (path)
+    (etypecase path
+      (logical-pathname
+       path)
+      ((or pathname string)
+       (ensure-output-translations)
+       (loop* :with p = (resolve-symlinks* path)
+              :for (source destination) :in (car *output-translations*)
+              :for root = (when (or (eq source t)
+                                    (and (pathnamep source)
+                                         (not (absolute-pathname-p source))))
+                            (pathname-root p))
+              :for absolute-source = (cond
+                                       ((eq source t) (wilden root))
+                                       (root (merge-pathnames* source root))
+                                       (t source))
+              :when (or (eq source t) (pathname-match-p p absolute-source))
+              :return (translate-pathname* p absolute-source destination root source)
+              :finally (return p)))))
+
+  ;; Hook into asdf/driver's output-translation mechanism
+  #-cormanlisp
+  (setf *output-translation-function* 'apply-output-translations)
+
+  #+abcl
+  (defun translate-jar-pathname (source wildcard)
+    (declare (ignore wildcard))
+    (flet ((normalize-device (pathname)
+             (if (find :windows *features*)
+                 pathname
+                 (make-pathname :defaults pathname :device :unspecific))))
+      (let* ((jar
+               (pathname (first (pathname-device source))))
+             (target-root-directory-namestring
+               (format nil "/___jar___file___root___/~@[~A/~]"
+                       (and (find :windows *features*)
+                            (pathname-device jar))))
+             (relative-source
+               (relativize-pathname-directory source))
+             (relative-jar
+               (relativize-pathname-directory (ensure-directory-pathname jar)))
+             (target-root-directory
+               (normalize-device
+                (pathname-directory-pathname
+                 (parse-namestring target-root-directory-namestring))))
+             (target-root
+               (merge-pathnames* relative-jar target-root-directory))
+             (target
+               (merge-pathnames* relative-source target-root)))
+        (normalize-device (apply-output-translations target))))))
+
+;;;; -----------------------------------------------------------------
+;;;; Source Registry Configuration, by Francois-Rene Rideau
+;;;; See the Manual and https://bugs.launchpad.net/asdf/+bug/485918
+
+(asdf/package:define-package :asdf/source-registry
+  (:recycle :asdf/source-registry :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade :asdf/find-system)
+  (:export
+   #:*source-registry-parameter* #:*default-source-registries*
+   #:invalid-source-registry
+   #:source-registry-initialized-p
+   #:initialize-source-registry #:clear-source-registry #:*source-registry*
+   #:ensure-source-registry #:*source-registry-parameter*
+   #:*default-source-registry-exclusions* #:*source-registry-exclusions*
+   #:*wild-asd* #:directory-asd-files #:register-asd-directory
+   #:collect-asds-in-directory #:collect-sub*directories-asd-files
+   #:validate-source-registry-directive #:validate-source-registry-form
+   #:validate-source-registry-file #:validate-source-registry-directory
+   #:parse-source-registry-string #:wrapping-source-registry #:default-source-registry
+   #:user-source-registry #:system-source-registry
+   #:user-source-registry-directory #:system-source-registry-directory
+   #:environment-source-registry #:process-source-registry
+   #:compute-source-registry #:flatten-source-registry
+   #:sysdef-source-registry-search))
+(in-package :asdf/source-registry)
+
+(with-upgradability ()
+  (define-condition invalid-source-registry (invalid-configuration warning)
+    ((format :initform (compatfmt "~@<Invalid source registry ~S~@[ in ~S~]~@{ ~@?~}~@:>"))))
+
+  ;; Using ack 1.2 exclusions
+  (defvar *default-source-registry-exclusions*
+    '(".bzr" ".cdv"
+      ;; "~.dep" "~.dot" "~.nib" "~.plst" ; we don't support ack wildcards
+      ".git" ".hg" ".pc" ".svn" "CVS" "RCS" "SCCS" "_darcs"
+      "_sgbak" "autom4te.cache" "cover_db" "_build"
+      "debian")) ;; debian often builds stuff under the debian directory... BAD.
+
+  (defvar *source-registry-exclusions* *default-source-registry-exclusions*)
+
+  (defvar *source-registry* nil
+    "Either NIL (for uninitialized), or an equal hash-table, mapping
+system names to pathnames of .asd files")
+
+  (defun source-registry-initialized-p ()
+    (typep *source-registry* 'hash-table))
+
+  (defun clear-source-registry ()
+    "Undoes any initialization of the source registry."
+    (setf *source-registry* nil)
+    (values))
+  (register-clear-configuration-hook 'clear-source-registry)
+
+  (defparameter *wild-asd*
+    (make-pathname* :directory nil :name *wild* :type "asd" :version :newest))
+
+  (defun directory-asd-files (directory)
+    (directory-files directory *wild-asd*))
+
+  (defun collect-asds-in-directory (directory collect)
+    (map () collect (directory-asd-files directory)))
+
+  (defun collect-sub*directories-asd-files
+      (directory &key (exclude *default-source-registry-exclusions*) collect)
+    (collect-sub*directories
+     directory
+     (constantly t)
+     #'(lambda (x &aux (l (car (last (pathname-directory x))))) (not (member l exclude :test #'equal)))
+     #'(lambda (dir) (collect-asds-in-directory dir collect))))
+
+  (defun validate-source-registry-directive (directive)
+    (or (member directive '(:default-registry))
+        (and (consp directive)
+             (let ((rest (rest directive)))
+               (case (first directive)
+                 ((:include :directory :tree)
+                  (and (length=n-p rest 1)
+                       (location-designator-p (first rest))))
+                 ((:exclude :also-exclude)
+                  (every #'stringp rest))
+                 ((:default-registry)
+                  (null rest)))))))
+
+  (defun validate-source-registry-form (form &key location)
+    (validate-configuration-form
+     form :source-registry 'validate-source-registry-directive
+          :location location :invalid-form-reporter 'invalid-source-registry))
+
+  (defun validate-source-registry-file (file)
+    (validate-configuration-file
+     file 'validate-source-registry-form :description "a source registry"))
+
+  (defun validate-source-registry-directory (directory)
+    (validate-configuration-directory
+     directory :source-registry 'validate-source-registry-directive
+               :invalid-form-reporter 'invalid-source-registry))
+
+  (defun parse-source-registry-string (string &key location)
+    (cond
+      ((or (null string) (equal string ""))
+       '(:source-registry :inherit-configuration))
+      ((not (stringp string))
+       (error (compatfmt "~@<Environment string isn't: ~3i~_~S~@:>") string))
+      ((find (char string 0) "\"(")
+       (validate-source-registry-form (read-from-string string) :location location))
+      (t
+       (loop
+         :with inherit = nil
+         :with directives = ()
+         :with start = 0
+         :with end = (length string)
+         :with separator = (inter-directory-separator)
+         :for pos = (position separator string :start start) :do
+           (let ((s (subseq string start (or pos end))))
+             (flet ((check (dir)
+                      (unless (absolute-pathname-p dir)
+                        (error (compatfmt "~@<source-registry string must specify absolute pathnames: ~3i~_~S~@:>") string))
+                      dir))
+               (cond
+                 ((equal "" s) ; empty element: inherit
+                  (when inherit
+                    (error (compatfmt "~@<Only one inherited configuration allowed: ~3i~_~S~@:>")
+                           string))
+                  (setf inherit t)
+                  (push ':inherit-configuration directives))
+                 ((string-suffix-p s "//") ;; TODO: allow for doubling of separator even outside Unix?
+                  (push `(:tree ,(check (subseq s 0 (- (length s) 2)))) directives))
+                 (t
+                  (push `(:directory ,(check s)) directives))))
+             (cond
+               (pos
+                (setf start (1+ pos)))
+               (t
+                (unless inherit
+                  (push '(:ignore-inherited-configuration) directives))
+                (return `(:source-registry ,@(nreverse directives))))))))))
+
+  (defun register-asd-directory (directory &key recurse exclude collect)
+    (if (not recurse)
+        (collect-asds-in-directory directory collect)
+        (collect-sub*directories-asd-files
+         directory :exclude exclude :collect collect)))
+
+  (defparameter *default-source-registries*
+    '(environment-source-registry
+      user-source-registry
+      user-source-registry-directory
+      system-source-registry
+      system-source-registry-directory
+      default-source-registry))
+
+  (defparameter *source-registry-file* (parse-unix-namestring "source-registry.conf"))
+  (defparameter *source-registry-directory* (parse-unix-namestring "source-registry.conf.d/"))
+
+  (defun wrapping-source-registry ()
+    `(:source-registry
+      #+(or ecl sbcl) (:tree ,(resolve-symlinks* (lisp-implementation-directory)))
+      #+mkcl (:tree ,(translate-logical-pathname "CONTRIB:"))
+      :inherit-configuration
+      #+cmu (:tree #p"modules:")
+      #+scl (:tree #p"file://modules/")))
+  (defun default-source-registry ()
+    `(:source-registry
+      #+sbcl (:directory ,(subpathname (user-homedir-pathname) ".sbcl/systems/"))
+      ,@(loop :for dir :in
+              `(,@(when (os-unix-p)
+                    `(,(or (getenv-absolute-directory "XDG_DATA_HOME")
+                           (subpathname (user-homedir-pathname) ".local/share/"))
+                      ,@(or (getenv-absolute-directories "XDG_DATA_DIRS")
+                            '("/usr/local/share" "/usr/share"))))
+                ,@(when (os-windows-p)
+                    (mapcar 'get-folder-path '(:local-appdata :appdata :common-appdata))))
+              :collect `(:directory ,(subpathname* dir "common-lisp/systems/"))
+              :collect `(:tree ,(subpathname* dir "common-lisp/source/")))
+      :inherit-configuration))
+  (defun user-source-registry (&key (direction :input))
+    (in-user-configuration-directory *source-registry-file* :direction direction))
+  (defun system-source-registry (&key (direction :input))
+    (in-system-configuration-directory *source-registry-file* :direction direction))
+  (defun user-source-registry-directory (&key (direction :input))
+    (in-user-configuration-directory *source-registry-directory* :direction direction))
+  (defun system-source-registry-directory (&key (direction :input))
+    (in-system-configuration-directory *source-registry-directory* :direction direction))
+  (defun environment-source-registry ()
+    (getenv "CL_SOURCE_REGISTRY"))
+
+  (defgeneric* (process-source-registry) (spec &key inherit register))
+
+  (defun* (inherit-source-registry) (inherit &key register)
+    (when inherit
+      (process-source-registry (first inherit) :register register :inherit (rest inherit))))
+
+  (defun* (process-source-registry-directive) (directive &key inherit register)
+    (destructuring-bind (kw &rest rest) (if (consp directive) directive (list directive))
+      (ecase kw
+        ((:include)
+         (destructuring-bind (pathname) rest
+           (process-source-registry (resolve-location pathname) :inherit nil :register register)))
+        ((:directory)
+         (destructuring-bind (pathname) rest
+           (when pathname
+             (funcall register (resolve-location pathname :ensure-directory t)))))
+        ((:tree)
+         (destructuring-bind (pathname) rest
+           (when pathname
+             (funcall register (resolve-location pathname :ensure-directory t)
+                      :recurse t :exclude *source-registry-exclusions*))))
+        ((:exclude)
+         (setf *source-registry-exclusions* rest))
+        ((:also-exclude)
+         (appendf *source-registry-exclusions* rest))
+        ((:default-registry)
+         (inherit-source-registry '(default-source-registry) :register register))
         ((:inherit-configuration)
-         (inherit-output-translations inherit :collect collect))
-        ((:ignore-inherited-configuration nil)
-         nil))
-      (let ((src (first directive))
-            (dst (second directive)))
-        (if (eq src :include)
-            (when dst
-              (process-output-translations (pathname dst) :inherit nil :collect collect))
-            (when src
-              (let ((trusrc (or (eql src t)
-                                (let ((loc (resolve-location src :directory t :wilden t)))
-                                  (if (absolute-pathname-p loc) (truenamize loc) loc)))))
-                (cond
-                  ((location-function-p dst)
-                   (funcall collect
-                            (list trusrc
-                                  (if (symbolp (second dst))
-                                      (fdefinition (second dst))
-                                      (eval (second dst))))))
-                  ((eq dst t)
-                   (funcall collect (list trusrc t)))
-                  (t
-                   (let* ((trudst (make-pathname
-                                   :defaults (if dst (resolve-location dst :directory t :wilden t) trusrc)))
-                          (wilddst (make-pathname
-                                    :name :wild :type :wild :version :wild
-                                    :defaults trudst)))
-                     (funcall collect (list wilddst t))
-                     (funcall collect (list trusrc trudst)))))))))))
-
-(defun* compute-output-translations (&optional parameter)
-  "read the configuration, return it"
-  (remove-duplicates
-   (while-collecting (c)
-     (inherit-output-translations
-      `(wrapping-output-translations ,parameter ,@*default-output-translations*) :collect #'c))
-   :test 'equal :from-end t))
-
-(defun* initialize-output-translations (&optional parameter)
-  "read the configuration, initialize the internal configuration variable,
-return the configuration"
-  (setf (output-translations) (compute-output-translations parameter)))
-
-(defun* disable-output-translations ()
-  "Initialize output translations in a way that maps every file to itself,
-effectively disabling the output translation facility."
-  (initialize-output-translations
-   '(:output-translations :disable-cache :ignore-inherited-configuration)))
-
-;; checks an initial variable to see whether the state is initialized
-;; or cleared. In the former case, return current configuration; in
-;; the latter, initialize.  ASDF will call this function at the start
-;; of (asdf:find-system).
-(defun* ensure-output-translations ()
-  (if (output-translations-initialized-p)
-      (output-translations)
-      (initialize-output-translations)))
-
-(defun* translate-pathname* (path absolute-source destination &optional root source)
-  (declare (ignore source))
-  (cond
-    ((functionp destination)
-     (funcall destination path absolute-source))
-    ((eq destination t)
-     path)
-    ((not (pathnamep destination))
-     (error "invalid destination"))
-    ((not (absolute-pathname-p destination))
-     (translate-pathname path absolute-source (merge-pathnames* destination root)))
-    (root
-     (translate-pathname (directorize-pathname-host-device path) absolute-source destination))
-    (t
-     (translate-pathname path absolute-source destination))))
-
-(defun* apply-output-translations (path)
-  (etypecase path
-    (logical-pathname
-     path)
-    ((or pathname string)
-     (ensure-output-translations)
-     (loop :with p = (truenamize path)
-       :for (source destination) :in (car *output-translations*)
-       :for root = (when (or (eq source t)
-                             (and (pathnamep source)
-                                  (not (absolute-pathname-p source))))
-                     (pathname-root p))
-       :for absolute-source = (cond
-                                ((eq source t) (wilden root))
-                                (root (merge-pathnames* source root))
-                                (t source))
-       :when (or (eq source t) (pathname-match-p p absolute-source))
-       :return (translate-pathname* p absolute-source destination root source)
-       :finally (return p)))))
-
-(defmethod output-files :around (operation component)
-  "Translate output files, unless asked not to"
-  (declare (ignorable operation component))
-  (values
-   (multiple-value-bind (files fixedp) (call-next-method)
-     (if fixedp
-         files
-         (mapcar #'apply-output-translations files)))
-   t))
-
-(defun* compile-file-pathname* (input-file &rest keys &key output-file &allow-other-keys)
-  (or output-file
-      (apply-output-translations
-       (apply 'compile-file-pathname
-              (truenamize (lispize-pathname input-file))
-              keys))))
-
-(defun* tmpize-pathname (x)
-  (make-pathname
-   :name (format nil "ASDF-TMP-~A" (pathname-name x))
-   :defaults x))
-
-(defun* delete-file-if-exists (x)
-  (when (and x (probe-file x))
-    (delete-file x)))
-
-(defun* compile-file* (input-file &rest keys &key output-file &allow-other-keys)
-  (let* ((output-file (or output-file (apply 'compile-file-pathname* input-file keys)))
-         (tmp-file (tmpize-pathname output-file))
-         (status :error))
-    (multiple-value-bind (output-truename warnings-p failure-p)
-        (apply 'compile-file input-file :output-file tmp-file keys)
-      (cond
-        (failure-p
-         (setf status *compile-file-failure-behaviour*))
-        (warnings-p
-         (setf status *compile-file-warnings-behaviour*))
-        (t
-         (setf status :success)))
-      (ecase status
-        ((:success :warn :ignore)
-         (delete-file-if-exists output-file)
-         (when output-truename
-           (rename-file output-truename output-file)
-           (setf output-truename output-file)))
-        (:error
-         (delete-file-if-exists output-truename)
-         (setf output-truename nil)))
-      (values output-truename warnings-p failure-p))))
-
-#+abcl
-(defun* translate-jar-pathname (source wildcard)
-  (declare (ignore wildcard))
-  (let* ((p (pathname (first (pathname-device source))))
-         (root (format nil "/___jar___file___root___/~@[~A/~]"
-                       (and (find :windows *features*)
-                            (pathname-device p)))))
-    (apply-output-translations
-     (merge-pathnames*
-      (relativize-pathname-directory source)
-      (merge-pathnames*
-       (relativize-pathname-directory (ensure-directory-pathname p))
-       root)))))
-
-;;;; -----------------------------------------------------------------
-;;;; Compatibility mode for ASDF-Binary-Locations
-
-(defmethod operate :before (operation-class system &rest args &key &allow-other-keys)
-  (declare (ignorable operation-class system args))
-  (when (find-symbol* '#:output-files-for-system-and-operation :asdf)
-    (error "ASDF 2 is not compatible with ASDF-BINARY-LOCATIONS, which you are using.
+         (inherit-source-registry inherit :register register))
+        ((:ignore-inherited-configuration)
+         nil)))
+    nil)
+
+  (defmethod process-source-registry ((x symbol) &key inherit register)
+    (process-source-registry (funcall x) :inherit inherit :register register))
+  (defmethod process-source-registry ((pathname #-gcl2.6 pathname #+gcl2.6 t) &key inherit register)
+    (cond
+      ((directory-pathname-p pathname)
+       (let ((*here-directory* (resolve-symlinks* pathname)))
+         (process-source-registry (validate-source-registry-directory pathname)
+                                  :inherit inherit :register register)))
+      ((probe-file* pathname :truename *resolve-symlinks*)
+       (let ((*here-directory* (pathname-directory-pathname pathname)))
+         (process-source-registry (validate-source-registry-file pathname)
+                                  :inherit inherit :register register)))
+      (t
+       (inherit-source-registry inherit :register register))))
+  (defmethod process-source-registry ((string string) &key inherit register)
+    (process-source-registry (parse-source-registry-string string)
+                             :inherit inherit :register register))
+  (defmethod process-source-registry ((x null) &key inherit register)
+    (declare (ignorable x))
+    (inherit-source-registry inherit :register register))
+  (defmethod process-source-registry ((form cons) &key inherit register)
+    (let ((*source-registry-exclusions* *default-source-registry-exclusions*))
+      (dolist (directive (cdr (validate-source-registry-form form)))
+        (process-source-registry-directive directive :inherit inherit :register register))))
+
+  (defun flatten-source-registry (&optional parameter)
+    (remove-duplicates
+     (while-collecting (collect)
+       (with-pathname-defaults () ;; be location-independent
+         (inherit-source-registry
+          `(wrapping-source-registry
+            ,parameter
+            ,@*default-source-registries*)
+          :register #'(lambda (directory &key recurse exclude)
+                        (collect (list directory :recurse recurse :exclude exclude))))))
+     :test 'equal :from-end t))
+
+  ;; Will read the configuration and initialize all internal variables.
+  (defun compute-source-registry (&optional parameter (registry *source-registry*))
+    (dolist (entry (flatten-source-registry parameter))
+      (destructuring-bind (directory &key recurse exclude) entry
+        (let* ((h (make-hash-table :test 'equal))) ; table to detect duplicates
+          (register-asd-directory
+           directory :recurse recurse :exclude exclude :collect
+           #'(lambda (asd)
+               (let* ((name (pathname-name asd))
+                      (name (if (typep asd 'logical-pathname)
+                                ;; logical pathnames are upper-case,
+                                ;; at least in the CLHS and on SBCL,
+                                ;; yet (coerce-name :foo) is lower-case.
+                                ;; won't work well with (load-system "Foo")
+                                ;; instead of (load-system 'foo)
+                                (string-downcase name)
+                                name)))
+                 (cond
+                   ((gethash name registry) ; already shadowed by something else
+                    nil)
+                   ((gethash name h) ; conflict at current level
+                    (when *verbose-out*
+                      (warn (compatfmt "~@<In source-registry entry ~A~@[/~*~] ~
+                                found several entries for ~A - picking ~S over ~S~:>")
+                            directory recurse name (gethash name h) asd)))
+                   (t
+                    (setf (gethash name registry) asd)
+                    (setf (gethash name h) asd))))))
+          h)))
+    (values))
+
+  (defvar *source-registry-parameter* nil)
+
+  (defun initialize-source-registry (&optional (parameter *source-registry-parameter*))
+    ;; Record the parameter used to configure the registry 
+    (setf *source-registry-parameter* parameter)
+    ;; Clear the previous registry database:
+    (setf *source-registry* (make-hash-table :test 'equal))
+    ;; Do it!
+    (compute-source-registry parameter))
+
+  ;; Checks an initial variable to see whether the state is initialized
+  ;; or cleared. In the former case, return current configuration; in
+  ;; the latter, initialize.  ASDF will call this function at the start
+  ;; of (asdf:find-system) to make sure the source registry is initialized.
+  ;; However, it will do so *without* a parameter, at which point it
+  ;; will be too late to provide a parameter to this function, though
+  ;; you may override the configuration explicitly by calling
+  ;; initialize-source-registry directly with your parameter.
+  (defun ensure-source-registry (&optional parameter)
+    (unless (source-registry-initialized-p)
+      (initialize-source-registry parameter))
+    (values))
+
+  (defun sysdef-source-registry-search (system)
+    (ensure-source-registry)
+    (values (gethash (primary-system-name system) *source-registry*))))
+
+
+;;;; -------------------------------------------------------------------------
+;;; Internal hacks for backward-compatibility 
+
+(asdf/package:define-package :asdf/backward-internals
+  (:recycle :asdf/backward-internals :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/system :asdf/component :asdf/operation
+   :asdf/find-system :asdf/action :asdf/lisp-action)
+  (:export ;; for internal use
+   #:load-sysdef #:make-temporary-package
+   #:%refresh-component-inline-methods
+   #:%resolve-if-component-dep-fails
+   #:make-sub-operation
+   #:load-sysdef #:make-temporary-package))
+(in-package :asdf/backward-internals)
+
+;;;; Backward compatibility with "inline methods"
+(with-upgradability ()
+  (defparameter +asdf-methods+
+    '(perform-with-restarts perform explain output-files operation-done-p))
+
+  (defun %remove-component-inline-methods (component)
+    (dolist (name +asdf-methods+)
+      (map ()
+           ;; this is inefficient as most of the stored
+           ;; methods will not be for this particular gf
+           ;; But this is hardly performance-critical
+           #'(lambda (m)
+               (remove-method (symbol-function name) m))
+           (component-inline-methods component)))
+    (component-inline-methods component) nil)
+
+  (defun %define-component-inline-methods (ret rest)
+    (loop* :for (key value) :on rest :by #'cddr
+           :for name = (and (keywordp key) (find key +asdf-methods+ :test 'string=))
+           :when name :do
+           (destructuring-bind (op &rest body) value
+             (loop :for arg = (pop body)
+                   :while (atom arg)
+                   :collect arg :into qualifiers
+                   :finally
+                      (destructuring-bind (o c) arg
+                        (pushnew
+                         (eval `(defmethod ,name ,@qualifiers ((,o ,op) (,c (eql ,ret))) ,@body))
+                         (component-inline-methods ret)))))))
+
+  (defun %refresh-component-inline-methods (component rest)
+    ;; clear methods, then add the new ones
+    (%remove-component-inline-methods component)
+    (%define-component-inline-methods component rest)))
+
+;;;; PARTIAL SUPPORT for the :if-component-dep-fails component attribute
+;; and the companion asdf:feature pseudo-dependency.
+;; This won't recurse into dependencies to accumulate feature conditions.
+;; Therefore it will accept the SB-ROTATE-BYTE of an old SBCL
+;; (older than 1.1.2.20-fe6da9f) but won't suffice to load an old nibbles.
+(with-upgradability ()
+  (defun %resolve-if-component-dep-fails (if-component-dep-fails component)
+    (asdf-message "The system definition for ~S uses deprecated ~
+                 ASDF option :IF-COMPONENT-DEP-DAILS. ~
+                 Starting with ASDF 3, please use :IF-FEATURE instead"
+                  (coerce-name (component-system component)))
+    ;; This only supports the pattern of use of the "feature" seen in the wild
+    (check-type component parent-component)
+    (check-type if-component-dep-fails (member :fail :ignore :try-next))
+    (unless (eq if-component-dep-fails :fail)
+      (loop :with o = (make-operation 'compile-op)
+            :for c :in (component-children component) :do
+              (loop* :for (feature? feature) :in (component-depends-on o c)
+                     :when (eq feature? 'feature) :do
+                     (setf (component-if-feature c) feature))))))
+
+(when-upgrading (:when (fboundp 'make-sub-operation))
+  (defun make-sub-operation (c o dep-c dep-o)
+    (declare (ignore c o dep-c dep-o)) (asdf-upgrade-error)))
+
+
+;;;; load-sysdef
+(with-upgradability ()
+  (defun load-sysdef (name pathname)
+    (load-asd pathname :name name))
+
+  (defun make-temporary-package ()
+    ;; For loading a .asd file, we dont't make a temporary package anymore,
+    ;; but use ASDF-USER. I'd like to have this function do this,
+    ;; but since whoever uses it is likely to delete-package the result afterwards,
+    ;; this would be a bad idea, so preserve the old behavior.
+    (make-package (fresh-package-name :prefix :asdf :index 0) :use '(:cl :asdf))))
+
+
+;;;; -------------------------------------------------------------------------
+;;;; Defsystem
+
+(asdf/package:define-package :asdf/defsystem
+  (:recycle :asdf/defsystem :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system :asdf/cache
+   :asdf/find-system :asdf/find-component :asdf/lisp-action :asdf/operate
+   :asdf/backward-internals)
+  (:export
+   #:defsystem #:register-system-definition
+   #:class-for-type #:*default-component-class*
+   #:determine-system-directory #:parse-component-form
+   #:duplicate-names #:non-toplevel-system #:non-system-system
+   #:sysdef-error-component #:check-component-input))
+(in-package :asdf/defsystem)
+
+;;; Pathname
+(with-upgradability ()
+  (defun determine-system-directory (pathname)
+    ;; The defsystem macro calls this function to determine
+    ;; the pathname of a system as follows:
+    ;; 1. if the pathname argument is an pathname object (NOT a namestring),
+    ;;    that is already an absolute pathname, return it.
+    ;; 2. otherwise, the directory containing the LOAD-PATHNAME
+    ;;    is considered (as deduced from e.g. *LOAD-PATHNAME*), and
+    ;;    if it is indeed available and an absolute pathname, then
+    ;;    the PATHNAME argument is normalized to a relative pathname
+    ;;    as per PARSE-UNIX-NAMESTRING (with ENSURE-DIRECTORY T)
+    ;;    and merged into that DIRECTORY as per SUBPATHNAME.
+    ;;    Note: avoid *COMPILE-FILE-PATHNAME* because .asd is loaded,
+    ;;    and may be from within the EVAL-WHEN of a file compilation.
+    ;; If no absolute pathname was found, we return NIL.
+    (check-type pathname (or null string pathname))
+    (pathname-directory-pathname
+     (resolve-symlinks*
+      (ensure-absolute-pathname
+       (parse-unix-namestring pathname :type :directory)
+       #'(lambda () (ensure-absolute-pathname
+                     (load-pathname) 'get-pathname-defaults nil))
+       nil)))))
+
+
+;;; Component class
+(with-upgradability ()
+  (defvar *default-component-class* 'cl-source-file)
+
+  (defun class-for-type (parent type)
+    (or (loop :for symbol :in (list
+                               type
+                               (find-symbol* type *package* nil)
+                               (find-symbol* type :asdf/interface nil)
+                               (and (stringp type) (safe-read-from-string type :package :asdf/interface)))
+              :for class = (and symbol (symbolp symbol) (find-class* symbol nil))
+              :when (and class
+                         (#-cormanlisp subtypep #+cormanlisp cl::subclassp
+                          class (find-class* 'component)))
+                :return class)
+        (and (eq type :file)
+             (find-class*
+              (or (loop :for p = parent :then (component-parent p) :while p
+                        :thereis (module-default-component-class p))
+                  *default-component-class*) nil))
+        (sysdef-error "don't recognize component type ~A" type))))
+
+
+;;; Check inputs
+(with-upgradability ()
+  (define-condition duplicate-names (system-definition-error)
+    ((name :initarg :name :reader duplicate-names-name))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<Error while defining system: multiple components are given same name ~S~@:>")
+                       (duplicate-names-name c)))))
+
+  (define-condition non-system-system (system-definition-error)
+    ((name :initarg :name :reader non-system-system-name)
+     (class-name :initarg :class-name :reader non-system-system-class-name))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<Error while defining system ~S: class ~S isn't a subclass of ~S~@:>")
+                       (non-system-system-name c) (non-system-system-class-name c) 'system))))
+
+  (define-condition non-toplevel-system (system-definition-error)
+    ((parent :initarg :parent :reader non-toplevel-system-parent)
+     (name :initarg :name :reader non-toplevel-system-name))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<Error while defining system: component ~S claims to have a system ~S as a child~@:>")
+                       (non-toplevel-system-parent c) (non-toplevel-system-name c)))))
+
+  (defun sysdef-error-component (msg type name value)
+    (sysdef-error (strcat msg (compatfmt "~&~@<The value specified for ~(~A~) ~A is ~S~@:>"))
+                  type name value))
+
+  (defun check-component-input (type name weakly-depends-on
+                                depends-on components)
+    "A partial test of the values of a component."
+    (unless (listp depends-on)
+      (sysdef-error-component ":depends-on must be a list."
+                              type name depends-on))
+    (unless (listp weakly-depends-on)
+      (sysdef-error-component ":weakly-depends-on must be a list."
+                              type name weakly-depends-on))
+    (unless (listp components)
+      (sysdef-error-component ":components must be NIL or a list of components."
+                              type name components)))
+
+  (defun* (normalize-version) (form &key pathname component parent)
+    (labels ((invalid (&optional (continuation "using NIL instead"))
+               (warn (compatfmt "~@<Invalid :version specifier ~S~@[ for component ~S~]~@[ in ~S~]~@[ from file ~S~]~@[, ~A~]~@:>")
+                     form component parent pathname continuation))
+             (invalid-parse (control &rest args)
+               (unless (builtin-system-p (find-component parent component))
+                 (apply 'warn control args)
+                 (invalid))))
+      (if-let (v (typecase form
+                   ((or string null) form)
+                   (real
+                    (invalid "Substituting a string")
+                    (format nil "~D" form)) ;; 1.0 becomes "1.0"
+                   (cons
+                    (case (first form)
+                      ((:read-file-form)
+                       (destructuring-bind (subpath &key (at 0)) (rest form)
+                         (safe-read-file-form (subpathname pathname subpath) :at at :package :asdf-user)))
+                      ((:read-file-line)
+                       (destructuring-bind (subpath &key (at 0)) (rest form)
+                         (read-file-lines (subpathname pathname subpath) :at at)))
+                      (otherwise
+                       (invalid))))
+                   (t
+                    (invalid))))
+        (if-let (pv (parse-version v #'invalid-parse))
+          (unparse-version pv)
+          (invalid))))))
+
+
+;;; Main parsing function
+(with-upgradability ()
+  (defun* (parse-component-form) (parent options &key previous-serial-component)
+    (destructuring-bind
+        (type name &rest rest &key
+                                (builtin-system-p () bspp)
+                                ;; the following list of keywords is reproduced below in the
+                                ;; remove-plist-keys form.  important to keep them in sync
+                                components pathname perform explain output-files operation-done-p
+                                weakly-depends-on depends-on serial
+                                do-first if-component-dep-fails version
+                                ;; list ends
+         &allow-other-keys) options
+      (declare (ignorable perform explain output-files operation-done-p builtin-system-p))
+      (check-component-input type name weakly-depends-on depends-on components)
+      (when (and parent
+                 (find-component parent name)
+                 (not ;; ignore the same object when rereading the defsystem
+                  (typep (find-component parent name)
+                         (class-for-type parent type))))
+        (error 'duplicate-names :name name))
+      (when do-first (error "DO-FIRST is not supported anymore as of ASDF 3"))
+      (let* ((name (coerce-name name))
+             (args `(:name ,name
+                     :pathname ,pathname
+                     ,@(when parent `(:parent ,parent))
+                     ,@(remove-plist-keys
+                        '(:components :pathname :if-component-dep-fails :version
+                          :perform :explain :output-files :operation-done-p
+                          :weakly-depends-on :depends-on :serial)
+                        rest)))
+             (component (find-component parent name))
+             (class (class-for-type parent type)))
+        (when (and parent (subtypep class 'system))
+          (error 'non-toplevel-system :parent parent :name name))
+        (if component ; preserve identity
+            (apply 'reinitialize-instance component args)
+            (setf component (apply 'make-instance class args)))
+        (component-pathname component) ; eagerly compute the absolute pathname
+        (let ((sysfile (system-source-file (component-system component)))) ;; requires the previous
+          (when (and (typep component 'system) (not bspp))
+            (setf (builtin-system-p component) (lisp-implementation-pathname-p sysfile)))
+          (setf version (normalize-version version :component name :parent parent :pathname sysfile)))
+        ;; Don't use the accessor: kluge to avoid upgrade issue on CCL 1.8.
+        ;; A better fix is required.
+        (setf (slot-value component 'version) version)
+        (when (typep component 'parent-component)
+          (setf (component-children component)
+                (loop
+                  :with previous-component = nil
+                  :for c-form :in components
+                  :for c = (parse-component-form component c-form
+                                                 :previous-serial-component previous-component)
+                  :for name = (component-name c)
+                  :collect c
+                  :when serial :do (setf previous-component name)))
+          (compute-children-by-name component))
+        (when previous-serial-component
+          (push previous-serial-component depends-on))
+        (when weakly-depends-on
+          ;; ASDF4: deprecate this feature and remove it.
+          (appendf depends-on
+                   (remove-if (complement #'(lambda (x) (find-system x nil))) weakly-depends-on)))
+        ;; Used by POIU. ASDF4: rename to component-depends-on?
+        (setf (component-sideway-dependencies component) depends-on)
+        (%refresh-component-inline-methods component rest)
+        (when if-component-dep-fails
+          (%resolve-if-component-dep-fails if-component-dep-fails component))
+        component)))
+
+  (defun register-system-definition
+      (name &rest options &key pathname (class 'system) (source-file () sfp)
+                            defsystem-depends-on &allow-other-keys)
+    ;; The system must be registered before we parse the body,
+    ;; otherwise we recur when trying to find an existing system
+    ;; of the same name to reuse options (e.g. pathname) from.
+    ;; To avoid infinite recursion in cases where you defsystem a system
+    ;; that is registered to a different location to find-system,
+    ;; we also need to remember it in a special variable *systems-being-defined*.
+    (with-system-definitions ()
+      (let* ((name (coerce-name name))
+             (source-file (if sfp source-file (resolve-symlinks* (load-pathname))))
+             (registered (system-registered-p name))
+             (registered! (if registered
+                              (rplaca registered (get-file-stamp source-file))
+                              (register-system
+                               (make-instance 'system :name name :source-file source-file))))
+             (system (reset-system (cdr registered!)
+                                   :name name :source-file source-file))
+             (component-options (remove-plist-key :class options))
+             (defsystem-dependencies (loop :for spec :in defsystem-depends-on :collect
+                                           (resolve-dependency-spec nil spec))))
+        (setf (gethash name *systems-being-defined*) system)
+        (apply 'load-systems defsystem-dependencies)
+        ;; We change-class AFTER we loaded the defsystem-depends-on
+        ;; since the class might be defined as part of those.
+        (let ((class (class-for-type nil class)))
+          (unless (subtypep class 'system)
+            (error 'non-system-system :name name :class-name (class-name class)))
+          (unless (eq (type-of system) class)
+            (change-class system class)))
+        (parse-component-form
+         nil (list*
+              :module name
+              :pathname (determine-system-directory pathname)
+              component-options)))))
+
+  (defmacro defsystem (name &body options)
+    `(apply 'register-system-definition ',name ',options)))
+;;;; -------------------------------------------------------------------------
+;;;; ASDF-Bundle
+
+(asdf/package:define-package :asdf/bundle
+  (:recycle :asdf/bundle :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system :asdf/find-system :asdf/find-component :asdf/operation
+   :asdf/action :asdf/lisp-action :asdf/plan :asdf/operate)
+  (:export
+   #:bundle-op #:bundle-op-build-args #:bundle-type
+   #:bundle-system #:bundle-pathname-type #:bundlable-file-p #:direct-dependency-files
+   #:monolithic-op #:monolithic-bundle-op #:operation-monolithic-p
+   #:basic-fasl-op #:prepare-fasl-op #:fasl-op #:load-fasl-op #:monolithic-fasl-op
+   #:lib-op #:monolithic-lib-op
+   #:dll-op #:monolithic-dll-op
+   #:binary-op #:monolithic-binary-op
+   #:program-op #:compiled-file #:precompiled-system #:prebuilt-system
+   #:user-system-p #:user-system #:trivial-system-p
+   #+ecl #:make-build
+   #:register-pre-built-system
+   #:build-args #:name-suffix #:prologue-code #:epilogue-code #:static-library))
+(in-package :asdf/bundle)
+
+(with-upgradability ()
+  (defclass bundle-op (operation)
+    ((build-args :initarg :args :initform nil :accessor bundle-op-build-args)
+     (name-suffix :initarg :name-suffix :initform nil)
+     (bundle-type :initform :no-output-file :reader bundle-type)
+     #+ecl (lisp-files :initform nil :accessor bundle-op-lisp-files)
+     #+mkcl (do-fasb :initarg :do-fasb :initform t :reader bundle-op-do-fasb-p)
+     #+mkcl (do-static-library :initarg :do-static-library :initform t :reader bundle-op-do-static-library-p)))
+
+  (defclass bundle-compile-op (bundle-op basic-compile-op)
+    ()
+    (:documentation "Abstract operation for ways to bundle the outputs of compiling *Lisp* files"))
+
+  ;; create a single fasl for the entire library
+  (defclass basic-fasl-op (bundle-compile-op)
+    ((bundle-type :initform :fasl)))
+  (defclass prepare-fasl-op (sideway-operation)
+    ((sideway-operation :initform 'load-fasl-op)))
+  (defclass fasl-op (basic-fasl-op selfward-operation)
+    ((selfward-operation :initform '(prepare-fasl-op #+ecl lib-op))))
+  (defclass load-fasl-op (basic-load-op selfward-operation)
+    ((selfward-operation :initform '(prepare-op fasl-op))))
+
+  ;; NB: since the monolithic-op's can't be sideway-operation's,
+  ;; if we wanted lib-op, dll-op, binary-op to be sideway-operation's,
+  ;; we'd have to have the monolithic-op not inherit from the main op,
+  ;; but instead inherit from a basic-FOO-op as with basic-fasl-op above.
+
+  (defclass lib-op (bundle-compile-op)
+    ((bundle-type :initform #+(or ecl mkcl) :lib #-(or ecl mkcl) :no-output-file))
+    (:documentation #+(or ecl mkcl) "compile the system and produce linkable (.a) library for it."
+     #-(or ecl mkcl) "just compile the system"))
+
+  (defclass dll-op (bundle-op basic-compile-op)
+    ((bundle-type :initform :dll))
+    (:documentation "Link together all the dynamic library used by this system into a single one."))
+
+  (defclass binary-op (basic-compile-op selfward-operation)
+    ((selfward-operation :initform '(fasl-op lib-op)))
+    (:documentation "produce fasl and asd files for the system"))
+
+  (defclass monolithic-op (operation) ()) ;; operation on a system and its dependencies
+
+  (defclass monolithic-bundle-op (monolithic-op bundle-op)
+    ((prologue-code :accessor monolithic-op-prologue-code)
+     (epilogue-code :accessor monolithic-op-epilogue-code)))
+
+  (defclass monolithic-bundle-compile-op (monolithic-bundle-op bundle-compile-op)
+    ()
+    (:documentation "Abstract operation for ways to bundle the outputs of compiling *Lisp* files over all systems"))
+
+  (defclass monolithic-binary-op (monolithic-op binary-op)
+    ((selfward-operation :initform '(monolithic-fasl-op monolithic-lib-op)))
+    (:documentation "produce fasl and asd files for combined system and dependencies."))
+
+  (defclass monolithic-fasl-op (monolithic-bundle-compile-op basic-fasl-op) ()
+    (:documentation "Create a single fasl for the system and its dependencies."))
+
+  (defclass monolithic-lib-op (monolithic-bundle-compile-op basic-compile-op)
+    ((bundle-type :initform #+(or ecl mkcl) :lib #-(or ecl mkcl) :no-output-file))
+    (:documentation #+(or ecl mkcl) "Create a single linkable library for the system and its dependencies."
+     #-(or ecl mkcl) "Compile a system and its dependencies."))
+
+  (defclass monolithic-dll-op (monolithic-bundle-op basic-compile-op sideway-operation selfward-operation)
+    ((bundle-type :initform :dll)
+     (selfward-operation :initform 'dll-op)
+     (sideway-operation :initform 'dll-op)))
+
+  (defclass program-op #+(or mkcl ecl) (monolithic-bundle-compile-op)
+            #-(or mkcl ecl) (monolithic-bundle-op selfward-operation)
+    ((bundle-type :initform :program)
+     #-(or mkcl ecl) (selfward-operation :initform #-(or mkcl ecl) 'load-op))
+    (:documentation "create an executable file from the system and its dependencies"))
+
+  (defun bundle-pathname-type (bundle-type)
+    (etypecase bundle-type
+      ((eql :no-output-file) nil) ;; should we error out instead?
+      ((or null string) bundle-type)
+      ((eql :fasl) #-(or ecl mkcl) (compile-file-type) #+(or ecl mkcl) "fasb")
+      #+ecl
+      ((member :binary :dll :lib :static-library :program :object :program)
+       (compile-file-type :type bundle-type))
+      ((eql :binary) "image")
+      ((eql :dll) (cond ((os-unix-p) "so") ((os-windows-p) "dll")))
+      ((member :lib :static-library) (cond ((os-unix-p) "a") ((os-windows-p) "lib")))
+      ((eql :program) (cond ((os-unix-p) nil) ((os-windows-p) "exe")))))
+
+  (defun bundle-output-files (o c)
+    (when (input-files o c)
+      (let ((bundle-type (bundle-type o)))
+        (unless (eq bundle-type :no-output-file) ;; NIL already means something regarding type.
+          (let ((name (or (component-build-pathname c)
+                          (format nil "~A~@[~A~]" (component-name c) (slot-value o 'name-suffix))))
+                (type (bundle-pathname-type bundle-type)))
+            (values (list (subpathname (component-pathname c) name :type type))
+                    (eq (type-of o) (component-build-operation c))))))))
+
+  (defmethod output-files ((o bundle-op) (c system))
+    (bundle-output-files o c))
+
+  #-(or ecl mkcl)
+  (defmethod perform ((o program-op) (c system))
+    (let ((output-file (output-file o c)))
+      (setf *image-entry-point* (ensure-function (component-entry-point c)))
+      (dump-image output-file :executable t)))
+
+  (defclass compiled-file (file-component)
+    ((type :initform #-(or ecl mkcl) (compile-file-type) #+(or ecl mkcl) "fasb")))
+
+  (defclass precompiled-system (system)
+    ((build-pathname :initarg :fasl)))
+
+  (defclass prebuilt-system (system)
+    ((build-pathname :initarg :static-library :initarg :lib
+                     :accessor prebuilt-system-static-library))))
+
+
+;;;
+;;; BUNDLE-OP
+;;;
+;;; This operation takes all components from one or more systems and
+;;; creates a single output file, which may be
+;;; a FASL, a statically linked library, a shared library, etc.
+;;; The different targets are defined by specialization.
+;;;
+(with-upgradability ()
+  (defun operation-monolithic-p (op)
+    (typep op 'monolithic-op))
+
+  (defmethod initialize-instance :after ((instance bundle-op) &rest initargs
+                                         &key (name-suffix nil name-suffix-p)
+                                         &allow-other-keys)
+    (declare (ignorable initargs name-suffix))
+    (unless name-suffix-p
+      (setf (slot-value instance 'name-suffix)
+            (unless (typep instance 'program-op)
+              (if (operation-monolithic-p instance) "--all-systems" #-ecl "--system")))) ; . no good for Logical Pathnames
+    (when (typep instance 'monolithic-bundle-op)
+      (destructuring-bind (&rest original-initargs
+                           &key lisp-files prologue-code epilogue-code
+                           &allow-other-keys)
+          (operation-original-initargs instance)
+        (setf (operation-original-initargs instance)
+              (remove-plist-keys '(:lisp-files :epilogue-code :prologue-code) original-initargs)
+              (monolithic-op-prologue-code instance) prologue-code
+              (monolithic-op-epilogue-code instance) epilogue-code)
+        #-ecl (assert (null (or lisp-files epilogue-code prologue-code)))
+        #+ecl (setf (bundle-op-lisp-files instance) lisp-files)))
+    (setf (bundle-op-build-args instance)
+          (remove-plist-keys '(:type :monolithic :name-suffix)
+                             (operation-original-initargs instance))))
+
+  (defmethod bundle-op-build-args :around ((o lib-op))
+    (declare (ignorable o))
+    (let ((args (call-next-method)))
+      (remf args :ld-flags)
+      args))
+
+  (defun bundlable-file-p (pathname)
+    (let ((type (pathname-type pathname)))
+      (declare (ignorable type))
+      (or #+ecl (or (equalp type (compile-file-type :type :object))
+                    (equalp type (compile-file-type :type :static-library)))
+          #+mkcl (equalp type (compile-file-type :fasl-p nil))
+          #+(or abcl allegro clisp clozure cmu lispworks sbcl scl xcl) (equalp type (compile-file-type)))))
+
+  (defgeneric* (trivial-system-p) (component))
+
+  (defun user-system-p (s)
+    (and (typep s 'system)
+         (not (builtin-system-p s))
+         (not (trivial-system-p s)))))
+
+(eval-when (#-lispworks :compile-toplevel :load-toplevel :execute)
+  (deftype user-system () '(and system (satisfies user-system-p))))
+
+;;;
+;;; First we handle monolithic bundles.
+;;; These are standalone systems which contain everything,
+;;; including other ASDF systems required by the current one.
+;;; A PROGRAM is always monolithic.
+;;;
+;;; MONOLITHIC SHARED LIBRARIES, PROGRAMS, FASL
+;;;
+(with-upgradability ()
+  (defmethod component-depends-on ((o bundle-compile-op) (c system))
+    `(,(if (operation-monolithic-p o)
+           `(#-(or ecl mkcl) fasl-op #+(or ecl mkcl) lib-op
+               ,@(required-components c :other-systems t :component-type 'system
+                                        :goal-operation (find-operation o 'load-op)
+                                        :keep-operation 'compile-op))
+           `(compile-op
+             ,@(required-components c :other-systems nil :component-type '(not system)
+                                      :goal-operation (find-operation o 'load-op)
+                                      :keep-operation 'compile-op)))
+      ,@(call-next-method)))
+
+  (defmethod component-depends-on :around ((o bundle-op) (c component))
+    (declare (ignorable o c))
+    (if-let (op (and (eq (type-of o) 'bundle-op) (component-build-operation c)))
+      `((,op ,c))
+      (call-next-method)))
+
+  (defun direct-dependency-files (o c &key (test 'identity) (key 'output-files) &allow-other-keys)
+    ;; This file selects output files from direct dependencies;
+    ;; your component-depends-on method better gathered the correct dependencies in the correct order.
+    (while-collecting (collect)
+      (map-direct-dependencies
+       o c #'(lambda (sub-o sub-c)
+               (loop :for f :in (funcall key sub-o sub-c)
+                     :when (funcall test f) :do (collect f))))))
+
+  (defmethod input-files ((o bundle-compile-op) (c system))
+    (unless (eq (bundle-type o) :no-output-file)
+      (direct-dependency-files o c :test 'bundlable-file-p :key 'output-files)))
+
+  (defun select-bundle-operation (type &optional monolithic)
+    (ecase type
+      ((:binary)
+       (if monolithic 'monolithic-binary-op 'binary-op))
+      ((:dll :shared-library)
+       (if monolithic 'monolithic-dll-op 'dll-op))
+      ((:lib :static-library)
+       (if monolithic 'monolithic-lib-op 'lib-op))
+      ((:fasl)
+       (if monolithic 'monolithic-fasl-op 'fasl-op))
+      ((:program)
+       'program-op)))
+
+  (defun make-build (system &rest args &key (monolithic nil) (type :fasl)
+                             (move-here nil move-here-p)
+                             &allow-other-keys)
+    (let* ((operation-name (select-bundle-operation type monolithic))
+           (move-here-path (if (and move-here
+                                    (typep move-here '(or pathname string)))
+                               (pathname move-here)
+                               (system-relative-pathname system "asdf-output/")))
+           (operation (apply #'operate operation-name
+                             system
+                             (remove-plist-keys '(:monolithic :type :move-here) args)))
+           (system (find-system system))
+           (files (and system (output-files operation system))))
+      (if (or move-here (and (null move-here-p)
+                             (member operation-name '(:program :binary))))
+          (loop :with dest-path = (resolve-symlinks* (ensure-directories-exist move-here-path))
+                :for f :in files
+                :for new-f = (make-pathname :name (pathname-name f)
+                                            :type (pathname-type f)
+                                            :defaults dest-path)
+                :do (rename-file-overwriting-target f new-f)
+                :collect new-f)
+          files))))
+
+;;;
+;;; LOAD-FASL-OP
+;;;
+;;; This is like ASDF's LOAD-OP, but using monolithic fasl files.
+;;;
+(with-upgradability ()
+  (defmethod component-depends-on ((o load-fasl-op) (c system))
+    (declare (ignorable o))
+    `((,o ,@(loop :for dep :in (component-sideway-dependencies c)
+                  :collect (resolve-dependency-spec c dep)))
+      (,(if (user-system-p c) 'fasl-op 'load-op) ,c)
+      ,@(call-next-method)))
+
+  (defmethod input-files ((o load-fasl-op) (c system))
+    (when (user-system-p c)
+      (output-files (find-operation o 'fasl-op) c)))
+
+  (defmethod perform ((o load-fasl-op) c)
+    (declare (ignorable o c))
+    nil)
+
+  (defmethod perform ((o load-fasl-op) (c system))
+    (when (input-files o c)
+      (perform-lisp-load-fasl o c)))
+
+  (defmethod mark-operation-done :after ((o load-fasl-op) (c system))
+    (mark-operation-done (find-operation o 'load-op) c)))
+
+;;;
+;;; PRECOMPILED FILES
+;;;
+;;; This component can be used to distribute ASDF systems in precompiled form.
+;;; Only useful when the dependencies have also been precompiled.
+;;;
+(with-upgradability ()
+  (defmethod trivial-system-p ((s system))
+    (every #'(lambda (c) (typep c 'compiled-file)) (component-children s)))
+
+  (defmethod output-files (o (c compiled-file))
+    (declare (ignorable o c))
+    nil)
+  (defmethod input-files (o (c compiled-file))
+    (declare (ignorable o))
+    (component-pathname c))
+  (defmethod perform ((o load-op) (c compiled-file))
+    (perform-lisp-load-fasl o c))
+  (defmethod perform ((o load-source-op) (c compiled-file))
+    (perform (find-operation o 'load-op) c))
+  (defmethod perform ((o load-fasl-op) (c compiled-file))
+    (perform (find-operation o 'load-op) c))
+  (defmethod perform ((o operation) (c compiled-file))
+    (declare (ignorable o c))
+    nil))
+
+;;;
+;;; Pre-built systems
+;;;
+(with-upgradability ()
+  (defmethod trivial-system-p ((s prebuilt-system))
+    (declare (ignorable s))
+    t)
+
+  (defmethod perform ((o lib-op) (c prebuilt-system))
+    (declare (ignorable o c))
+    nil)
+
+  (defmethod component-depends-on ((o lib-op) (c prebuilt-system))
+    (declare (ignorable o c))
+    nil)
+
+  (defmethod component-depends-on ((o monolithic-lib-op) (c prebuilt-system))
+    (declare (ignorable o))
+    nil))
+
+
+;;;
+;;; PREBUILT SYSTEM CREATOR
+;;;
+(with-upgradability ()
+  (defmethod output-files ((o binary-op) (s system))
+    (list (make-pathname :name (component-name s) :type "asd"
+                         :defaults (component-pathname s))))
+
+  (defmethod perform ((o binary-op) (s system))
+    (let* ((inputs (input-files o s))
+           (fasl (first inputs))
+           (library (second inputs))
+           (asd (first (output-files o s)))
+           (name (if (and fasl asd) (pathname-name asd) (return-from perform)))
+           (dependencies
+             (if (operation-monolithic-p o)
+                 (remove-if-not 'builtin-system-p
+                                (required-components s :component-type 'system
+                                                       :keep-operation 'load-op))
+                 (while-collecting (x) ;; resolve the sideway-dependencies of s
+                   (map-direct-dependencies
+                    'load-op s
+                    #'(lambda (o c)
+                        (when (and (typep o 'load-op) (typep c 'system))
+                          (x c)))))))
+           (depends-on (mapcar 'coerce-name dependencies)))
+      (when (pathname-equal asd (system-source-file s))
+        (cerror "overwrite the asd file"
+                "~/asdf-action:format-action/ is going to overwrite the system definition file ~S which is probably not what you want; you probably need to tweak your output translations."
+                (cons o s) asd))
+      (with-open-file (s asd :direction :output :if-exists :supersede
+                             :if-does-not-exist :create)
+        (format s ";;; Prebuilt~:[~; monolithic~] ASDF definition for system ~A~%"
+                (operation-monolithic-p o) name)
+        (format s ";;; Built for ~A ~A on a ~A/~A ~A~%"
+                (lisp-implementation-type)
+                (lisp-implementation-version)
+                (software-type)
+                (machine-type)
+                (software-version))
+        (let ((*package* (find-package :asdf-user)))
+          (pprint `(defsystem ,name
+                     :class prebuilt-system
+                     :depends-on ,depends-on
+                     :components ((:compiled-file ,(pathname-name fasl)))
+                     ,@(when library `(:lib ,(file-namestring library))))
+                  s)
+          (terpri s)))))
+
+  #-(or ecl mkcl)
+  (defmethod perform ((o bundle-compile-op) (c system))
+    (let* ((input-files (input-files o c))
+           (fasl-files (remove (compile-file-type) input-files :key #'pathname-type :test-not #'equalp))
+           (non-fasl-files (remove (compile-file-type) input-files :key #'pathname-type :test #'equalp))
+           (output-files (output-files o c))
+           (output-file (first output-files)))
+      (assert (eq (not input-files) (not output-files)))
+      (when input-files
+        (when non-fasl-files
+          (error "On ~A, asdf-bundle can only bundle FASL files, but these were also produced: ~S"
+                 (implementation-type) non-fasl-files))
+        (when (and (typep o 'monolithic-bundle-op)
+                   (or (monolithic-op-prologue-code o) (monolithic-op-epilogue-code o)))
+          (error "prologue-code and epilogue-code are not supported on ~A"
+                 (implementation-type)))
+        (with-staging-pathname (output-file)
+          (combine-fasls fasl-files output-file)))))
+
+  (defmethod input-files ((o load-op) (s precompiled-system))
+    (declare (ignorable o))
+    (bundle-output-files (find-operation o 'fasl-op) s))
+
+  (defmethod perform ((o load-op) (s precompiled-system))
+    (perform-lisp-load-fasl o s))
+
+  (defmethod component-depends-on ((o load-fasl-op) (s precompiled-system))
+    (declare (ignorable o))
+    `((load-op ,s) ,@(call-next-method))))
+
+  #| ;; Example use:
+(asdf:defsystem :precompiled-asdf-utils :class asdf::precompiled-system :fasl (asdf:apply-output-translations (asdf:system-relative-pathname :asdf-utils "asdf-utils.system.fasl")))
+(asdf:load-system :precompiled-asdf-utils)
+|#
+
+#+ecl
+(with-upgradability ()
+  (defmethod perform ((o bundle-compile-op) (c system))
+    (let* ((object-files (input-files o c))
+           (output (output-files o c))
+           (bundle (first output))
+           (kind (bundle-type o)))
+      (when output
+        (create-image
+         bundle (append object-files (bundle-op-lisp-files o))
+         :kind kind
+         :entry-point (component-entry-point c)
+         :prologue-code
+         (when (typep o 'monolithic-bundle-op)
+           (monolithic-op-prologue-code o))
+         :epilogue-code
+         (when (typep o 'monolithic-bundle-op)
+           (monolithic-op-epilogue-code o))
+         :build-args (bundle-op-build-args o))))))
+
+#+mkcl
+(with-upgradability ()
+  (defmethod perform ((o lib-op) (s system))
+    (apply #'compiler::build-static-library (output-file o c)
+           :lisp-object-files (input-files o s) (bundle-op-build-args o)))
+
+  (defmethod perform ((o basic-fasl-op) (s system))
+    (apply #'compiler::build-bundle (output-file o c) ;; second???
+           :lisp-object-files (input-files o s) (bundle-op-build-args o)))
+
+  (defun bundle-system (system &rest args &key force (verbose t) version &allow-other-keys)
+    (declare (ignore force verbose version))
+    (apply #'operate 'binary-op system args)))
+
+#+(or ecl mkcl)
+(with-upgradability ()
+  (defun register-pre-built-system (name)
+    (register-system (make-instance 'system :name (coerce-name name) :source-file nil))))
+
+;;;; -------------------------------------------------------------------------
+;;;; Concatenate-source
+
+(asdf/package:define-package :asdf/concatenate-source
+  (:recycle :asdf/concatenate-source :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/operation
+   :asdf/system :asdf/find-system :asdf/defsystem
+   :asdf/action :asdf/lisp-action :asdf/bundle)
+  (:export
+   #:concatenate-source-op
+   #:load-concatenated-source-op
+   #:compile-concatenated-source-op
+   #:load-compiled-concatenated-source-op
+   #:monolithic-concatenate-source-op
+   #:monolithic-load-concatenated-source-op
+   #:monolithic-compile-concatenated-source-op
+   #:monolithic-load-compiled-concatenated-source-op))
+(in-package :asdf/concatenate-source)
+
+;;;
+;;; Concatenate sources
+;;;
+(with-upgradability ()
+  (defclass basic-concatenate-source-op (bundle-op)
+    ((bundle-type :initform "lisp")))
+  (defclass basic-load-concatenated-source-op (basic-load-op selfward-operation) ())
+  (defclass basic-compile-concatenated-source-op (basic-compile-op selfward-operation) ())
+  (defclass basic-load-compiled-concatenated-source-op (basic-load-op selfward-operation) ())
+
+  (defclass concatenate-source-op (basic-concatenate-source-op) ())
+  (defclass load-concatenated-source-op (basic-load-concatenated-source-op)
+    ((selfward-operation :initform '(prepare-op concatenate-source-op))))
+  (defclass compile-concatenated-source-op (basic-compile-concatenated-source-op)
+    ((selfward-operation :initform '(prepare-op concatenate-source-op))))
+  (defclass load-compiled-concatenated-source-op (basic-load-compiled-concatenated-source-op)
+    ((selfward-operation :initform '(prepare-op compile-concatenated-source-op))))
+
+  (defclass monolithic-concatenate-source-op (basic-concatenate-source-op monolithic-bundle-op) ())
+  (defclass monolithic-load-concatenated-source-op (basic-load-concatenated-source-op)
+    ((selfward-operation :initform 'monolithic-concatenate-source-op)))
+  (defclass monolithic-compile-concatenated-source-op (basic-compile-concatenated-source-op)
+    ((selfward-operation :initform 'monolithic-concatenate-source-op)))
+  (defclass monolithic-load-compiled-concatenated-source-op (basic-load-compiled-concatenated-source-op)
+    ((selfward-operation :initform 'monolithic-compile-concatenated-source-op)))
+
+  (defmethod input-files ((operation basic-concatenate-source-op) (s system))
+    (loop :with encoding = (or (component-encoding s) *default-encoding*)
+          :with other-encodings = '()
+          :with around-compile = (around-compile-hook s)
+          :with other-around-compile = '()
+          :for c :in (required-components
+                      s :goal-operation 'compile-op
+                        :keep-operation 'compile-op
+                        :other-systems (operation-monolithic-p operation))
+          :append
+          (when (typep c 'cl-source-file)
+            (let ((e (component-encoding c)))
+              (unless (equal e encoding)
+                (pushnew e other-encodings :test 'equal)))
+            (let ((a (around-compile-hook c)))
+              (unless (equal a around-compile)
+                (pushnew a other-around-compile :test 'equal)))
+            (input-files (make-operation 'compile-op) c)) :into inputs
+          :finally
+             (when other-encodings
+               (warn "~S uses encoding ~A but has sources that use these encodings: ~A"
+                     operation encoding other-encodings))
+             (when other-around-compile
+               (warn "~S uses around-compile hook ~A but has sources that use these hooks: ~A"
+                     operation around-compile other-around-compile))
+             (return inputs)))
+  (defmethod output-files ((o basic-compile-concatenated-source-op) (s system))
+    (lisp-compilation-output-files o s))
+
+  (defmethod perform ((o basic-concatenate-source-op) (s system))
+    (let ((inputs (input-files o s))
+          (output (output-file o s)))
+      (concatenate-files inputs output)))
+  (defmethod perform ((o basic-load-concatenated-source-op) (s system))
+    (perform-lisp-load-source o s))
+  (defmethod perform ((o basic-compile-concatenated-source-op) (s system))
+    (perform-lisp-compilation o s))
+  (defmethod perform ((o basic-load-compiled-concatenated-source-op) (s system))
+    (perform-lisp-load-fasl o s)))
+
+;;;; -------------------------------------------------------------------------
+;;; Backward-compatible interfaces
+
+(asdf/package:define-package :asdf/backward-interface
+  (:recycle :asdf/backward-interface :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/component :asdf/system :asdf/find-system :asdf/operation :asdf/action
+   :asdf/lisp-build :asdf/operate :asdf/output-translations)
+  (:export
+   #:*asdf-verbose*
+   #:operation-error #:compile-error #:compile-failed #:compile-warned
+   #:error-component #:error-operation
+   #:component-load-dependencies
+   #:enable-asdf-binary-locations-compatibility
+   #:operation-forced
+   #:operation-on-failure
+   #:operation-on-warnings
+   #:component-property
+   #:run-shell-command
+   #:system-definition-pathname))
+(in-package :asdf/backward-interface)
+
+(with-upgradability ()
+  (define-condition operation-error (error) ;; Bad, backward-compatible name
+    ;; Used by SBCL, cffi-tests, clsql-mysql, clsql-uffi, qt, elephant, uffi-tests, sb-grovel
+    ((component :reader error-component :initarg :component)
+     (operation :reader error-operation :initarg :operation))
+    (:report (lambda (c s)
+               (format s (compatfmt "~@<~A while invoking ~A on ~A~@:>")
+                       (type-of c) (error-operation c) (error-component c)))))
+  (define-condition compile-error (operation-error) ())
+  (define-condition compile-failed (compile-error) ())
+  (define-condition compile-warned (compile-error) ())
+
+  (defun component-load-dependencies (component)
+    ;; Old deprecated name for the same thing. Please update your software.
+    (component-sideway-dependencies component))
+
+  (defgeneric operation-forced (operation)) ;; Used by swank.asd for swank-loader.
+  (defmethod operation-forced ((o operation)) (getf (operation-original-initargs o) :force))
+
+  (defgeneric operation-on-warnings (operation))
+  (defgeneric operation-on-failure (operation))
+  #-gcl2.6 (defgeneric (setf operation-on-warnings) (x operation))
+  #-gcl2.6 (defgeneric (setf operation-on-failure) (x operation))
+  (defmethod operation-on-warnings ((o operation))
+    (declare (ignorable o)) *compile-file-warnings-behaviour*)
+  (defmethod operation-on-failure ((o operation))
+    (declare (ignorable o)) *compile-file-failure-behaviour*)
+  (defmethod (setf operation-on-warnings) (x (o operation))
+    (declare (ignorable o)) (setf *compile-file-warnings-behaviour* x))
+  (defmethod (setf operation-on-failure) (x (o operation))
+    (declare (ignorable o)) (setf *compile-file-failure-behaviour* x))
+
+  (defun system-definition-pathname (x)
+    ;; As of 2.014.8, we mean to make this function obsolete,
+    ;; but that won't happen until all clients have been updated.
+    ;;(cerror "Use ASDF:SYSTEM-SOURCE-FILE instead"
+    "Function ASDF:SYSTEM-DEFINITION-PATHNAME is obsolete.
+It used to expose ASDF internals with subtle differences with respect to
+user expectations, that have been refactored away since.
+We recommend you use ASDF:SYSTEM-SOURCE-FILE instead
+for a mostly compatible replacement that we're supporting,
+or even ASDF:SYSTEM-SOURCE-DIRECTORY or ASDF:SYSTEM-RELATIVE-PATHNAME
+if that's whay you mean." ;;)
+    (system-source-file x)))
+
+
+;;;; ASDF-Binary-Locations compatibility
+;; This remains supported for legacy user, but not recommended for new users.
+(with-upgradability ()
+  (defun enable-asdf-binary-locations-compatibility
+      (&key
+       (centralize-lisp-binaries nil)
+       (default-toplevel-directory
+        (subpathname (user-homedir-pathname) ".fasls/")) ;; Use ".cache/common-lisp/" instead ???
+       (include-per-user-information nil)
+       (map-all-source-files (or #+(or clisp ecl mkcl) t nil))
+       (source-to-target-mappings nil)
+       (file-types `(,(compile-file-type)
+                     "build-report"
+                     #+ecl (compile-file-type :type :object)
+                     #+mkcl (compile-file-type :fasl-p nil)
+                     #+clisp "lib" #+sbcl "cfasl"
+                     #+sbcl "sbcl-warnings" #+clozure "ccl-warnings")))
+    #+(or clisp ecl mkcl)
+    (when (null map-all-source-files)
+      (error "asdf:enable-asdf-binary-locations-compatibility doesn't support :map-all-source-files nil on CLISP, ECL and MKCL"))
+    (let* ((patterns (if map-all-source-files (list *wild-file*)
+                         (loop :for type :in file-types
+                               :collect (make-pathname :type type :defaults *wild-file*))))
+           (destination-directory
+             (if centralize-lisp-binaries
+                 `(,default-toplevel-directory
+                   ,@(when include-per-user-information
+                       (cdr (pathname-directory (user-homedir-pathname))))
+                   :implementation ,*wild-inferiors*)
+                 `(:root ,*wild-inferiors* :implementation))))
+      (initialize-output-translations
+       `(:output-translations
+         ,@source-to-target-mappings
+         #+abcl (#p"jar:file:/**/*.jar!/**/*.*" (:function translate-jar-pathname))
+         #+abcl (#p"/___jar___file___root___/**/*.*" (,@destination-directory))
+         ,@(loop :for pattern :in patterns
+                 :collect `((:root ,*wild-inferiors* ,pattern)
+                            (,@destination-directory ,pattern)))
+         (t t)
+         :ignore-inherited-configuration))))
+
+  (defmethod operate :before (operation-class system &rest args &key &allow-other-keys)
+    (declare (ignorable operation-class system args))
+    (when (find-symbol* '#:output-files-for-system-and-operation :asdf nil)
+      (error "ASDF 2 is not compatible with ASDF-BINARY-LOCATIONS, which you are using.
 ASDF 2 now achieves the same purpose with its builtin ASDF-OUTPUT-TRANSLATIONS,
 which should be easier to configure. Please stop using ASDF-BINARY-LOCATIONS,
 and instead use ASDF-OUTPUT-TRANSLATIONS. See the ASDF manual for details.
 In case you insist on preserving your previous A-B-L configuration, but
 do not know how to achieve the same effect with A-O-T, you may use function
 ASDF:ENABLE-ASDF-BINARY-LOCATIONS-COMPATIBILITY as documented in the manual;
-call that function where you would otherwise have loaded and configured A-B-L.")))
-
-(defun* enable-asdf-binary-locations-compatibility
-    (&key
-     (centralize-lisp-binaries nil)
-     (default-toplevel-directory
-         ;; Use ".cache/common-lisp" instead ???
-         (merge-pathnames* (make-pathname :directory '(:relative ".fasls"))
-                           (user-homedir)))
-     (include-per-user-information nil)
-     (map-all-source-files (or #+(or ecl clisp) t nil))
-     (source-to-target-mappings nil))
-  #+(or ecl clisp)
-  (when (null map-all-source-files)
-    (error "asdf:enable-asdf-binary-locations-compatibility doesn't support :map-all-source-files nil on ECL and CLISP"))
-  (let* ((fasl-type (pathname-type (compile-file-pathname "foo.lisp")))
-         (wild-inferiors (make-pathname :directory '(:relative :wild-inferiors)))
-         (mapped-files (make-pathname
-                        :name :wild :version :wild
-                        :type (if map-all-source-files :wild fasl-type)))
-         (destination-directory
-          (if centralize-lisp-binaries
-              `(,default-toplevel-directory
-                ,@(when include-per-user-information
-                        (cdr (pathname-directory (user-homedir))))
-                :implementation ,wild-inferiors)
-              `(:root ,wild-inferiors :implementation))))
-    (initialize-output-translations
-     `(:output-translations
-       ,@source-to-target-mappings
-       ((:root ,wild-inferiors ,mapped-files)
-        (,@destination-directory ,mapped-files))
-       (t t)
-       :ignore-inherited-configuration))))
-
-;;;; -----------------------------------------------------------------
-;;;; Windows shortcut support.  Based on:
-;;;;
-;;;; Jesse Hager: The Windows Shortcut File Format.
-;;;; http://www.wotsit.org/list.asp?fc=13
-
-#+(and (or win32 windows mswindows mingw32) (not cygwin) (not clisp))
-(progn
-(defparameter *link-initial-dword* 76)
-(defparameter *link-guid* #(1 20 2 0 0 0 0 0 192 0 0 0 0 0 0 70))
-
-(defun* read-null-terminated-string (s)
-  (with-output-to-string (out)
-    (loop :for code = (read-byte s)
-      :until (zerop code)
-      :do (write-char (code-char code) out))))
-
-(defun* read-little-endian (s &optional (bytes 4))
-  (loop
-    :for i :from 0 :below bytes
-    :sum (ash (read-byte s) (* 8 i))))
-
-(defun* parse-file-location-info (s)
-  (let ((start (file-position s))
-        (total-length (read-little-endian s))
-        (end-of-header (read-little-endian s))
-        (fli-flags (read-little-endian s))
-        (local-volume-offset (read-little-endian s))
-        (local-offset (read-little-endian s))
-        (network-volume-offset (read-little-endian s))
-        (remaining-offset (read-little-endian s)))
-    (declare (ignore total-length end-of-header local-volume-offset))
-    (unless (zerop fli-flags)
-      (cond
-        ((logbitp 0 fli-flags)
-          (file-position s (+ start local-offset)))
-        ((logbitp 1 fli-flags)
-          (file-position s (+ start
-                              network-volume-offset
-                              #x14))))
-      (concatenate 'string
-        (read-null-terminated-string s)
-        (progn
-          (file-position s (+ start remaining-offset))
-          (read-null-terminated-string s))))))
-
-(defun* parse-windows-shortcut (pathname)
-  (with-open-file (s pathname :element-type '(unsigned-byte 8))
-    (handler-case
-        (when (and (= (read-little-endian s) *link-initial-dword*)
-                   (let ((header (make-array (length *link-guid*))))
-                     (read-sequence header s)
-                     (equalp header *link-guid*)))
-          (let ((flags (read-little-endian s)))
-            (file-position s 76)        ;skip rest of header
-            (when (logbitp 0 flags)
-              ;; skip shell item id list
-              (let ((length (read-little-endian s 2)))
-                (file-position s (+ length (file-position s)))))
-            (cond
-              ((logbitp 1 flags)
-                (parse-file-location-info s))
-              (t
-                (when (logbitp 2 flags)
-                  ;; skip description string
-                  (let ((length (read-little-endian s 2)))
-                    (file-position s (+ length (file-position s)))))
-                (when (logbitp 3 flags)
-                  ;; finally, our pathname
-                  (let* ((length (read-little-endian s 2))
-                         (buffer (make-array length)))
-                    (read-sequence buffer s)
-                    (map 'string #'code-char buffer)))))))
-      (end-of-file ()
-        nil)))))
-
-;;;; -----------------------------------------------------------------
-;;;; Source Registry Configuration, by Francois-Rene Rideau
-;;;; See the Manual and https://bugs.launchpad.net/asdf/+bug/485918
-
-;; Using ack 1.2 exclusions
-(defvar *default-source-registry-exclusions*
-  '(".bzr" ".cdv"
-    ;; "~.dep" "~.dot" "~.nib" "~.plst" ; we don't support ack wildcards
-    ".git" ".hg" ".pc" ".svn" "CVS" "RCS" "SCCS" "_darcs"
-    "_sgbak" "autom4te.cache" "cover_db" "_build"
-    "debian")) ;; debian often build stuff under the debian directory... BAD.
-
-(defvar *source-registry-exclusions* *default-source-registry-exclusions*)
-
-(defvar *source-registry* ()
-  "Either NIL (for uninitialized), or a list of one element,
-said element itself being a list of directory pathnames where to look for .asd files")
-
-(defun* source-registry ()
-  (car *source-registry*))
-
-(defun* (setf source-registry) (new-value)
-  (setf *source-registry* (list new-value))
-  new-value)
-
-(defun* source-registry-initialized-p ()
-  (and *source-registry* t))
-
-(defun* clear-source-registry ()
-  "Undoes any initialization of the source registry.
-You might want to call that before you dump an image that would be resumed
-with a different configuration, so the configuration would be re-read then."
-  (setf *source-registry* '())
-  (values))
-
-(defparameter *wild-asd*
-  (make-pathname :directory nil :name :wild :type "asd" :version :newest))
-
-(defun directory-has-asd-files-p (directory)
-  (and (ignore-errors
-         (directory (merge-pathnames* *wild-asd* directory)
-                    #+sbcl #+sbcl :resolve-symlinks nil
-                    #+ccl #+ccl :follow-links nil
-                    #+clisp #+clisp :circle t))
-       t))
-
-(defun subdirectories (directory)
-  (let* ((directory (ensure-directory-pathname directory))
-         #-cormanlisp
-         (wild (merge-pathnames*
-                #-(or abcl allegro lispworks scl)
-                (make-pathname :directory '(:relative :wild) :name nil :type nil :version nil)
-                #+(or abcl allegro lispworks scl) "*.*"
-                directory))
-         (dirs
-          #-cormanlisp
-          (ignore-errors
-            (directory wild .
-              #.(or #+allegro '(:directories-are-files nil :follow-symbolic-links nil)
-                    #+ccl '(:follow-links nil :directories t :files nil)
-                    #+clisp '(:circle t :if-does-not-exist :ignore)
-                    #+(or cmu scl) '(:follow-links nil :truenamep nil)
-                    #+digitool '(:directories t)
-                    #+sbcl '(:resolve-symlinks nil))))
-          #+cormanlisp (cl::directory-subdirs directory))
-         #+(or abcl allegro lispworks scl)
-         (dirs (remove-if-not #+abcl #'extensions:probe-directory
-                              #+allegro #'excl:probe-directory
-                              #+lispworks #'lw:file-directory-p
-                              #-(or abcl allegro lispworks) #'directory-pathname-p
-                              dirs)))
-    dirs))
-
-(defun collect-sub*directories (directory collectp recursep collector)
-  (when (funcall collectp directory)
-    (funcall collector directory))
-  (dolist (subdir (subdirectories directory))
-    (when (funcall recursep subdir)
-      (collect-sub*directories subdir collectp recursep collector))))
-
-(defun collect-sub*directories-with-asd
-    (directory &key
-     (exclude *default-source-registry-exclusions*)
-     collect)
-  (collect-sub*directories
-   directory
-   #'directory-has-asd-files-p
-   #'(lambda (x) (not (member (car (last (pathname-directory x))) exclude :test #'equal)))
-   collect))
-
-(defun* validate-source-registry-directive (directive)
-  (unless
-      (or (member directive '(:default-registry (:default-registry)) :test 'equal)
-          (destructuring-bind (kw &rest rest) directive
-            (case kw
-              ((:include :directory :tree)
-               (and (length=n-p rest 1)
-                    (location-designator-p (first rest))))
-              ((:exclude :also-exclude)
-               (every #'stringp rest))
-              (null rest))))
-    (error "Invalid directive ~S~%" directive))
-  directive)
-
-(defun* validate-source-registry-form (form)
-  (validate-configuration-form
-   form :source-registry 'validate-source-registry-directive "a source registry"))
-
-(defun* validate-source-registry-file (file)
-  (validate-configuration-file
-   file 'validate-source-registry-form "a source registry"))
-
-(defun* validate-source-registry-directory (directory)
-  (validate-configuration-directory
-   directory :source-registry 'validate-source-registry-directive))
-
-(defun* parse-source-registry-string (string)
-  (cond
-    ((or (null string) (equal string ""))
-     '(:source-registry :inherit-configuration))
-    ((not (stringp string))
-     (error "environment string isn't: ~S" string))
-    ((find (char string 0) "\"(")
-     (validate-source-registry-form (read-from-string string)))
-    (t
-     (loop
-      :with inherit = nil
-      :with directives = ()
-      :with start = 0
-      :with end = (length string)
-      :for pos = (position *inter-directory-separator* string :start start) :do
-      (let ((s (subseq string start (or pos end))))
-        (cond
-         ((equal "" s) ; empty element: inherit
-          (when inherit
-            (error "only one inherited configuration allowed: ~S" string))
-          (setf inherit t)
-          (push ':inherit-configuration directives))
-         ((ends-with s "//")
-          (push `(:tree ,(subseq s 0 (1- (length s)))) directives))
-         (t
-          (push `(:directory ,s) directives)))
-        (cond
-          (pos
-           (setf start (1+ pos)))
-          (t
-           (unless inherit
-             (push '(:ignore-inherited-configuration) directives))
-           (return `(:source-registry ,@(nreverse directives))))))))))
-
-(defun* register-asd-directory (directory &key recurse exclude collect)
-  (if (not recurse)
-      (funcall collect directory)
-      (collect-sub*directories-with-asd
-       directory :exclude exclude :collect collect)))
-
-(defparameter *default-source-registries*
-  '(environment-source-registry
-    user-source-registry
-    user-source-registry-directory
-    system-source-registry
-    system-source-registry-directory
-    default-source-registry))
-
-(defparameter *source-registry-file* #p"source-registry.conf")
-(defparameter *source-registry-directory* #p"source-registry.conf.d/")
-
-(defun* wrapping-source-registry ()
-  `(:source-registry
-    #+sbcl (:tree ,(getenv "SBCL_HOME"))
-    :inherit-configuration
-    #+cmu (:tree #p"modules:")))
-(defun* default-source-registry ()
-  (flet ((try (x sub) (try-directory-subpath x sub :type :directory)))
-    `(:source-registry
-      #+sbcl (:directory ,(merge-pathnames* ".sbcl/systems/" (user-homedir)))
-      (:directory ,(truenamize (directory-namestring *default-pathname-defaults*)))
-      ,@(let*
-         #+(or unix cygwin)
-         ((datahome
-           (or (getenv "XDG_DATA_HOME")
-               (try (user-homedir) ".local/share/")))
-          (datadirs
-           (or (getenv "XDG_DATA_DIRS") "/usr/local/share:/usr/share"))
-          (dirs (cons datahome (split-string datadirs :separator ":"))))
-         #+(and (or win32 windows mswindows mingw32) (not cygwin))
-         ((datahome (getenv "APPDATA"))
-          (datadir
-           #+lispworks (sys:get-folder-path :local-appdata)
-           #-lispworks (try (getenv "ALLUSERSPROFILE")
-                            "Application Data"))
-          (dirs (list datahome datadir)))
-         #-(or unix win32 windows mswindows mingw32 cygwin)
-         ((dirs ()))
-         (loop :for dir :in dirs
-           :collect `(:directory ,(try dir "common-lisp/systems/"))
-           :collect `(:tree ,(try dir "common-lisp/source/"))))
-      :inherit-configuration)))
-(defun* user-source-registry ()
-  (in-user-configuration-directory *source-registry-file*))
-(defun* system-source-registry ()
-  (in-system-configuration-directory *source-registry-file*))
-(defun* user-source-registry-directory ()
-  (in-user-configuration-directory *source-registry-directory*))
-(defun* system-source-registry-directory ()
-  (in-system-configuration-directory *source-registry-directory*))
-(defun* environment-source-registry ()
-  (getenv "CL_SOURCE_REGISTRY"))
-
-(defgeneric* process-source-registry (spec &key inherit register))
-(declaim (ftype (function (t &key (:register (or symbol function))) t)
-                inherit-source-registry))
-(declaim (ftype (function (t &key (:register (or symbol function)) (:inherit list)) t)
-                process-source-registry-directive))
-
-(defmethod process-source-registry ((x symbol) &key inherit register)
-  (process-source-registry (funcall x) :inherit inherit :register register))
-(defmethod process-source-registry ((pathname pathname) &key inherit register)
-  (cond
-    ((directory-pathname-p pathname)
-     (process-source-registry (validate-source-registry-directory pathname)
-                              :inherit inherit :register register))
-    ((probe-file pathname)
-     (process-source-registry (validate-source-registry-file pathname)
-                              :inherit inherit :register register))
-    (t
-     (inherit-source-registry inherit :register register))))
-(defmethod process-source-registry ((string string) &key inherit register)
-  (process-source-registry (parse-source-registry-string string)
-                           :inherit inherit :register register))
-(defmethod process-source-registry ((x null) &key inherit register)
-  (declare (ignorable x))
-  (inherit-source-registry inherit :register register))
-(defmethod process-source-registry ((form cons) &key inherit register)
-  (let ((*source-registry-exclusions* *default-source-registry-exclusions*))
-    (dolist (directive (cdr (validate-source-registry-form form)))
-      (process-source-registry-directive directive :inherit inherit :register register))))
-
-(defun* inherit-source-registry (inherit &key register)
-  (when inherit
-    (process-source-registry (first inherit) :register register :inherit (rest inherit))))
-
-(defun* process-source-registry-directive (directive &key inherit register)
-  (destructuring-bind (kw &rest rest) (if (consp directive) directive (list directive))
-    (ecase kw
-      ((:include)
-       (destructuring-bind (pathname) rest
-         (process-source-registry (resolve-location pathname) :inherit nil :register register)))
-      ((:directory)
-       (destructuring-bind (pathname) rest
-         (when pathname
-           (funcall register (resolve-location pathname :directory t)))))
-      ((:tree)
-       (destructuring-bind (pathname) rest
-         (when pathname
-           (funcall register (resolve-location pathname :directory t)
-                    :recurse t :exclude *source-registry-exclusions*))))
-      ((:exclude)
-       (setf *source-registry-exclusions* rest))
-      ((:also-exclude)
-       (appendf *source-registry-exclusions* rest))
-      ((:default-registry)
-       (inherit-source-registry '(default-source-registry) :register register))
-      ((:inherit-configuration)
-       (inherit-source-registry inherit :register register))
-      ((:ignore-inherited-configuration)
-       nil)))
-  nil)
-
-(defun* flatten-source-registry (&optional parameter)
-  (remove-duplicates
-   (while-collecting (collect)
-     (inherit-source-registry
-      `(wrapping-source-registry
-        ,parameter
-        ,@*default-source-registries*)
-      :register (lambda (directory &key recurse exclude)
-                  (collect (list directory :recurse recurse :exclude exclude)))))
-   :test 'equal :from-end t))
-
-;; Will read the configuration and initialize all internal variables,
-;; and return the new configuration.
-(defun* compute-source-registry (&optional parameter)
-  (while-collecting (collect)
-    (dolist (entry (flatten-source-registry parameter))
-      (destructuring-bind (directory &key recurse exclude) entry
-        (register-asd-directory
-         directory
-         :recurse recurse :exclude exclude :collect #'collect)))))
-
-(defun* initialize-source-registry (&optional parameter)
-  (setf (source-registry) (compute-source-registry parameter)))
-
-;; Checks an initial variable to see whether the state is initialized
-;; or cleared. In the former case, return current configuration; in
-;; the latter, initialize.  ASDF will call this function at the start
-;; of (asdf:find-system) to make sure the source registry is initialized.
-;; However, it will do so *without* a parameter, at which point it
-;; will be too late to provide a parameter to this function, though
-;; you may override the configuration explicitly by calling
-;; initialize-source-registry directly with your parameter.
-(defun* ensure-source-registry (&optional parameter)
-  (if (source-registry-initialized-p)
-      (source-registry)
-      (initialize-source-registry parameter)))
-
-(defun* sysdef-source-registry-search (system)
-  (ensure-source-registry)
-  (loop :with name = (coerce-name system)
-    :for defaults :in (source-registry)
-    :for file = (probe-asd name defaults)
-    :when file :return file))
-
-(defun* clear-configuration ()
-  (clear-source-registry)
-  (clear-output-translations))
-
-;;;; -----------------------------------------------------------------
-;;;; Hook into REQUIRE for ABCL, CLISP, ClozureCL, CMUCL, ECL and SBCL
-;;;;
-(defun* module-provide-asdf (name)
-  (handler-bind
-      ((style-warning #'muffle-warning)
-       (missing-component (lambda (c) (declare (ignore c)) nil))
-       (error (lambda (e)
-                (format *error-output* "ASDF could not load ~(~A~) because ~A.~%"
-                        name e))))
-    (let* ((*verbose-out* (make-broadcast-stream))
-           (system (find-system (string-downcase name) nil)))
-      (when system
-        (load-system system)
-        t))))
-
-#+(or abcl clisp clozure cmu ecl sbcl)
-(let ((x (and #+clisp (find-symbol* '#:*module-provider-functions* :custom))))
-  (when x
+call that function where you would otherwise have loaded and configured A-B-L."))))
+
+
+;;; run-shell-command
+;; WARNING! The function below is not just deprecated but also dysfunctional.
+;; Please use asdf/run-program:run-program instead.
+(with-upgradability ()
+  (defun run-shell-command (control-string &rest args)
+    "Interpolate ARGS into CONTROL-STRING as if by FORMAT, and
+synchronously execute the result using a Bourne-compatible shell, with
+output to *VERBOSE-OUT*.  Returns the shell's exit code.
+
+PLEASE DO NOT USE.
+Deprecated function, for backward-compatibility only.
+Please use ASDF-DRIVER:RUN-PROGRAM instead."
+    (let ((command (apply 'format nil control-string args)))
+      (asdf-message "; $ ~A~%" command)
+      (run-program command :force-shell t :ignore-error-status t :output *verbose-out*))))
+
+(with-upgradability ()
+  (defvar *asdf-verbose* nil)) ;; backward-compatibility with ASDF2 only. Unused.
+
+;; backward-compatibility methods. Do NOT use in new code. NOT SUPPORTED.
+(with-upgradability ()
+  (defgeneric component-property (component property))
+  (defgeneric (setf component-property) (new-value component property))
+
+  (defmethod component-property ((c component) property)
+    (cdr (assoc property (slot-value c 'properties) :test #'equal)))
+
+  (defmethod (setf component-property) (new-value (c component) property)
+    (let ((a (assoc property (slot-value c 'properties) :test #'equal)))
+      (if a
+          (setf (cdr a) new-value)
+          (setf (slot-value c 'properties)
+                (acons property new-value (slot-value c 'properties)))))
+    new-value))
+;;;; ---------------------------------------------------------------------------
+;;;; Handle ASDF package upgrade, including implementation-dependent magic.
+
+(asdf/package:define-package :asdf/interface
+  (:nicknames :asdf :asdf-utilities)
+  (:recycle :asdf/interface :asdf)
+  (:unintern
+   #:*asdf-revision* #:around #:asdf-method-combination
+   #:do-traverse #:do-dep #:do-one-dep #:visit-action #:component-visited-p
+   #:split #:make-collector
+   #:loaded-systems ; makes for annoying SLIME completion
+   #:output-files-for-system-and-operation) ; obsolete ASDF-BINARY-LOCATION function
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade :asdf/cache
+   :asdf/component :asdf/system :asdf/find-system :asdf/find-component
+   :asdf/operation :asdf/action :asdf/lisp-action
+   :asdf/output-translations :asdf/source-registry
+   :asdf/plan :asdf/operate :asdf/defsystem :asdf/bundle :asdf/concatenate-source
+   :asdf/backward-internals :asdf/backward-interface)
+  ;; TODO: automatically generate interface with reexport?
+  (:export
+   #:defsystem #:find-system #:locate-system #:coerce-name
+   #:oos #:operate #:traverse #:perform-plan
+   #:system-definition-pathname #:with-system-definitions
+   #:search-for-system-definition #:find-component #:component-find-path
+   #:compile-system #:load-system #:load-systems
+   #:require-system #:test-system #:clear-system
+   #:operation #:make-operation #:find-operation
+   #:upward-operation #:downward-operation #:sideway-operation #:selfward-operation
+   #:build-system #:build-op
+   #:load-op #:prepare-op #:compile-op
+   #:prepare-source-op #:load-source-op #:test-op
+   #:feature #:version #:version-satisfies #:upgrade-asdf
+   #:implementation-identifier #:implementation-type #:hostname
+   #:input-files #:output-files #:output-file #:perform
+   #:operation-done-p #:explain #:action-description #:component-sideway-dependencies
+   #:needed-in-image-p
+   ;; #:run-program ; we can't export it, because SB-GROVEL :use's both ASDF and SB-EXT.
+   #:component-load-dependencies #:run-shell-command ; deprecated, do not use
+   #:bundle-op #:monolithic-bundle-op #:precompiled-system #:compiled-file #:bundle-system
+   #+ecl #:make-build
+   #:basic-fasl-op #:prepare-fasl-op #:fasl-op #:load-fasl-op #:monolithic-fasl-op
+   #:lib-op #:dll-op #:binary-op #:program-op
+   #:monolithic-lib-op #:monolithic-dll-op #:monolithic-binary-op
+   #:concatenate-source-op
+   #:load-concatenated-source-op
+   #:compile-concatenated-source-op
+   #:load-compiled-concatenated-source-op
+   #:monolithic-concatenate-source-op
+   #:monolithic-load-concatenated-source-op
+   #:monolithic-compile-concatenated-source-op
+   #:monolithic-load-compiled-concatenated-source-op
+   #:operation-monolithic-p
+   #:required-components
+   #:component-loaded-p
+
+   #:component #:parent-component #:child-component #:system #:module
+   #:file-component #:source-file #:c-source-file #:java-source-file
+   #:cl-source-file #:cl-source-file.cl #:cl-source-file.lsp
+   #:static-file #:doc-file #:html-file
+   #:file-type
+   #:source-file-type
+
+   #:component-children          ; component accessors
+   #:component-children-by-name
+   #:component-pathname
+   #:component-relative-pathname
+   #:component-name
+   #:component-version
+   #:component-parent
+   #:component-system
+   #:component-encoding
+   #:component-external-format
+
+   #:component-depends-on ; backward-compatible name rather than action-depends-on
+   #:module-components ; backward-compatibility
+   #:operation-on-warnings #:operation-on-failure ; backward-compatibility
+   #:component-property ; backward-compatibility
+
+   #:system-description
+   #:system-long-description
+   #:system-author
+   #:system-maintainer
+   #:system-license
+   #:system-licence
+   #:system-source-file
+   #:system-source-directory
+   #:system-relative-pathname
+   #:system-homepage
+   #:system-mailto
+   #:system-bug-tracker
+   #:system-long-name
+   #:system-source-control
+   #:map-systems
+
+   #:*system-definition-search-functions*   ; variables
+   #:*central-registry*
+   #:*compile-file-warnings-behaviour*
+   #:*compile-file-failure-behaviour*
+   #:*resolve-symlinks*
+   #:*load-system-operation*
+   #:*asdf-verbose* ;; unused. For backward-compatibility only.
+   #:*verbose-out*
+
+   #:asdf-version
+
+   #:compile-condition #:compile-file-error #:compile-warned-error #:compile-failed-error
+   #:compile-warned-warning #:compile-failed-warning
+   #:operation-error #:compile-failed #:compile-warned #:compile-error ;; backward compatibility
+   #:error-name
+   #:error-pathname
+   #:load-system-definition-error
+   #:error-component #:error-operation
+   #:system-definition-error
+   #:missing-component
+   #:missing-component-of-version
+   #:missing-dependency
+   #:missing-dependency-of-version
+   #:circular-dependency        ; errors
+   #:duplicate-names #:non-toplevel-system #:non-system-system
+
+   #:try-recompiling
+   #:retry
+   #:accept                     ; restarts
+   #:coerce-entry-to-directory
+   #:remove-entry-from-registry
+
+   #:*encoding-detection-hook*
+   #:*encoding-external-format-hook*
+   #:*default-encoding*
+   #:*utf-8-external-format*
+
+   #:clear-configuration
+   #:*output-translations-parameter*
+   #:initialize-output-translations
+   #:disable-output-translations
+   #:clear-output-translations
+   #:ensure-output-translations
+   #:apply-output-translations
+   #:compile-file*
+   #:compile-file-pathname*
+   #:*warnings-file-type* #:enable-deferred-warnings-check #:disable-deferred-warnings-check
+   #:enable-asdf-binary-locations-compatibility
+   #:*default-source-registries*
+   #:*source-registry-parameter*
+   #:initialize-source-registry
+   #:compute-source-registry
+   #:clear-source-registry
+   #:ensure-source-registry
+   #:process-source-registry
+   #:system-registered-p #:registered-systems #:already-loaded-systems
+   #:resolve-location
+   #:asdf-message
+   #:*user-cache*
+   #:user-output-translations-pathname
+   #:system-output-translations-pathname
+   #:user-output-translations-directory-pathname
+   #:system-output-translations-directory-pathname
+   #:user-source-registry
+   #:system-source-registry
+   #:user-source-registry-directory
+   #:system-source-registry-directory))
+
+;;;; ---------------------------------------------------------------------------
+;;;; ASDF-USER, where the action happens.
+
+(asdf/package:define-package :asdf/user
+  (:nicknames :asdf-user)
+  (:use :asdf/common-lisp :asdf/package :asdf/interface))
+;;;; -----------------------------------------------------------------------
+;;;; ASDF Footer: last words and cleanup
+
+(asdf/package:define-package :asdf/footer
+  (:recycle :asdf/footer :asdf)
+  (:use :asdf/common-lisp :asdf/driver :asdf/upgrade
+   :asdf/find-system :asdf/find-component :asdf/operation :asdf/action :asdf/lisp-action
+   :asdf/operate :asdf/bundle :asdf/concatenate-source
+   :asdf/output-translations :asdf/source-registry
+   :asdf/backward-internals :asdf/defsystem :asdf/backward-interface))
+(in-package :asdf/footer)
+
+;;;; Hook ASDF into the implementation's REQUIRE and other entry points.
+
+(with-upgradability ()
+  #+(or abcl clisp clozure cmu ecl mkcl sbcl)
+  (if-let (x (and #+clisp (find-symbol* '#:*module-provider-functions* :custom nil)))
     (eval `(pushnew 'module-provide-asdf
-            #+abcl sys::*module-provider-functions*
-            #+clisp ,x
-            #+clozure ccl:*module-provider-functions*
-            #+cmu ext:*module-provider-functions*
-            #+ecl si:*module-provider-functions*
-            #+sbcl sb-ext:*module-provider-functions*))))
-
-
-;;;; -------------------------------------------------------------------------
-;;;; Cleanups after hot-upgrade.
-;;;; Things to do in case we're upgrading from a previous version of ASDF.
-;;;; See https://bugs.launchpad.net/asdf/+bug/485687
-;;;;
-;;;; TODO: debug why it's not enough to upgrade from ECL <= 9.11.1
-(eval-when (:compile-toplevel :load-toplevel :execute)
-  #+ecl ;; Support upgrade from before ECL went to 1.369
-  (when (fboundp 'compile-op-system-p)
-    (defmethod compile-op-system-p ((op compile-op))
-      (getf :system-p (compile-op-flags op)))
-    (defmethod initialize-instance :after ((op compile-op)
-                                           &rest initargs
-                                           &key system-p &allow-other-keys)
-      (declare (ignorable initargs))
-      (when system-p (appendf (compile-op-flags op) (list :system-p system-p))))))
-
-;;;; -----------------------------------------------------------------
+                    #+abcl sys::*module-provider-functions*
+                    #+clisp ,x
+                    #+clozure ccl:*module-provider-functions*
+                    #+(or cmu ecl) ext:*module-provider-functions*
+                    #+mkcl mk-ext:*module-provider-functions*
+                    #+sbcl sb-ext:*module-provider-functions*)))
+
+  #+(or ecl mkcl)
+  (progn
+    (pushnew '("fasb" . si::load-binary) si:*load-hooks* :test 'equal :key 'car)
+
+    #+(or (and ecl win32) (and mkcl windows))
+    (unless (assoc "asd" #+ecl ext:*load-hooks* #+mkcl si::*load-hooks* :test 'equal)
+      (appendf #+ecl ext:*load-hooks* #+mkcl si::*load-hooks* '(("asd" . si::load-source))))
+
+    (setf #+ecl ext:*module-provider-functions* #+mkcl mk-ext::*module-provider-functions*
+          (loop :for f :in #+ecl ext:*module-provider-functions*
+                #+mkcl mk-ext::*module-provider-functions*
+                :collect
+                (if (eq f 'module-provide-asdf) f
+                    #'(lambda (name)
+                        (let ((l (multiple-value-list (funcall f name))))
+                          (and (first l) (register-pre-built-system (coerce-name name)))
+                          (values-list l))))))))
+
+
 ;;;; Done!
+(with-upgradability ()
+  #+allegro
+  (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
+    (setf excl:*warn-on-nested-reader-conditionals* asdf/common-lisp::*acl-warn-save*))
+
+  (dolist (f '(:asdf :asdf2 :asdf3)) (pushnew f *features*))
+
+  (provide :asdf)
+
+  (cleanup-upgraded-asdf))
+
 (when *load-verbose*
   (asdf-message ";; ASDF, version ~a~%" (asdf-version)))
 
-#+allegro
-(eval-when (:compile-toplevel :execute)
-  (when (boundp 'excl:*warn-on-nested-reader-conditionals*)
-    (setf excl:*warn-on-nested-reader-conditionals* *acl-warn-save*)))
-
-(pushnew :asdf *features*)
-(pushnew :asdf2 *features*)
-
-(provide :asdf)
-
-;;; Local Variables:
-;;; mode: lisp
-;;; End:
+