[clisp-list] Bug in linux:dirent

[Aurelio B. <cl...@bi...>]

There is a problem with linux:dirent and linux:readdir:


CL-USER> (setf *dd* (linux:opendir "/usr/local/src/clisp/"))
#<FOREIGN-ADDRESS #x08217808>
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19916 :D_OFF 0 :D_RECLEN 2 :D_TYPE 0 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19819 :D_OFF 0 :D_RECLEN 40960 :D_TYPE 24 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19917 :D_OFF 0 :D_RECLEN 11392 :D_TYPE 36 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19921 :D_OFF 0 :D_RECLEN 10368 :D_TYPE 41 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 20051 :D_OFF 0 :D_RECLEN 5120 :D_TYPE 203 :D_NAME "
")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 20093 :D_OFF 0 :D_RECLEN 25088 :D_TYPE 124 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19919 :D_OFF 0 :D_RECLEN 53504 :D_TYPE 59 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19923 :D_OFF 0 :D_RECLEN 54912 :D_TYPE 117 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 20091 :D_OFF 0 :D_RECLEN 32128 :D_TYPE 207 :D_NAME "")
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 20095 :D_OFF 0 :D_RECLEN 7808 :D_TYPE 53 :D_NAME "")
CL-USER> (linux:closedir *dd*)
0
CL-USER> 


The d_name field should of course contain the file name instead of
garbage. The cause of the bug seems to be the definition of the d_off
field as off_t in linux:dirent:


CL-USER> (use-package :ffi)
T
CL-USER> (def-c-struct my-dirent
  (d_ino long)
  (d_off long)
  (d_reclen ushort)
  (d_type uchar)
  (d_name (c-array-max character 256)))

MY-DIRENT
CL-USER> (def-call-out my-readdir 
    (:name "readdir")
    (:library "libglib.so") 
    (:language :stdc)
  (:arguments (dirp c-pointer))
  (:return-type (c-ptr-null my-dirent)))
MY-READDIR
CL-USER> (setf *dd* (linux:opendir "/usr/local/src/clisp/"))
#<FOREIGN-ADDRESS #x08219218>
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 19916 :D_OFF 2 :D_RECLEN 16 :D_TYPE 0 :D_NAME ".")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 19819 :D_OFF 1613824 :D_RECLEN 16 :D_TYPE 0 :D_NAME "..")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 19917 :D_OFF 2370688 :D_RECLEN 16 :D_TYPE 0 :D_NAME "CVS")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 19921 :D_OFF 2697344 :D_RECLEN 16 :D_TYPE 0 :D_NAME "doc")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 20051 :D_OFF 30086144 :D_RECLEN 16 :D_TYPE 0 :D_NAME "src")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 20093 :D_OFF 108814848 :D_RECLEN 16 :D_TYPE 0 :D_NAME "unix")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 19919 :D_OFF 289132800 :D_RECLEN 24 :D_TYPE 0 :D_NAME "benchmarks")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 19923 :D_OFF 326489728 :D_RECLEN 20 :D_TYPE 0 :D_NAME "emacs")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 20091 :D_OFF 332365184 :D_RECLEN 20 :D_TYPE 0 :D_NAME "tests")
CL-USER> (my-readdir *dd*)
#S(MY-DIRENT :D_INO 20095 :D_OFF 473243264 :D_RECLEN 20 :D_TYPE 0 :D_NAME "utils")
CL-USER> (linux:closedir *dd*)
0
CL-USER> 


off_t is defined in modules/bindings/glibc/linux.lisp by the following
two def-c-type:

(def-c-type __off_t long)
(def-c-type off_t __off_t)

but for some reasons I can't figure out d_off ends up to be a bit:


CL-USER> (setf *dd* (linux:opendir "/usr/local/src/clisp/"))
#<FOREIGN-ADDRESS #x08219218>
CL-USER> (linux:readdir *dd*)
#S(LINUX:dirent :D_INO 19916 :D_OFF 0 :D_RECLEN 2 :D_TYPE 0 :D_NAME "")
CL-USER> (inspect *)
#S(LINUX:dirent :D_INO 19916 :D_OFF 0 :D_RECLEN 2 :D_TYPE 0 :D_NAME ""):  structure object
 type: LINUX:dirent
0 [D_INO]:  19916
1 [D_OFF]:  0
2 [D_RECLEN]:  2
3 [D_TYPE]:  0
4 [D_NAME]:  ""
INSPECT-- type :h for help; :q to return to the REPL ---> 1

0:  atom
 type: BIT
 class: #1=#<BUILT-IN-CLASS INTEGER>
INSPECT-- type :h for help; :q to return to the REPL --->