Re: [Sbcl-devel] Bug in COMPILE?

[William H. N. <wil...@ai...>]

On Mon, May 13, 2002 at 12:09:12PM +0200, Matthias Hölzl wrote:
> The function COMPILE does not seem to handle macro definitions 
> correctly.  Using sbcl 0.7.2 I get the following behavior:
> 
> * (defmacro foo () ''x)
> FOO
> * (foo)
> X
> * (compile 'foo)
> FOO
> NIL
> NIL
> * (foo)
> debugger invoked on condition of type UNDEFINED-FUNCTION:
>   The function FOO is undefined.

Yep, that looks broken.

> (I cannot currently bootstrap sbcl on my system, but the relevant code 
> is not changed in sbcl 0.7.3)
> 
> The reason for this behavior is that COMPILE always compiles the 
> FDEFINITION of the symbol and only then checks whether to install it as 
> MACRO-FUNCTION or FDEFINITION.  According to the HyperSpec the behavior 
> should be
> 
> "If a non-nil name is given, then the resulting compiled function 
> replaces the existing function definition of name and the name is 
> returned as the primary value; if name is a symbol that names a macro, 
> its macro function is updated and the name is returned as the primary 
> value."
> 
> The definition of /macro/ points to /macro name/:
> 
> "macro name n. a name for which macro-function returns true and which 
> when used as the first element of a compound form identifies that form 
> as a macro form."
> 
> Therefore I think that the correct fix would be to change the initial 
> value for DEFINITION in the function COMPILE to
> 
> (defun compile (name &optional (definition (or (macro-function name) 
> 
>                                                (fdefinition name))))
>   ...)

OK, that sounds pretty reasonable. In my currently-checked-out copy of
SBCL I'm already busy with some fixes to GET-MACRO-CHARACTER, so I
won't do it immediately, but after I finish testing, possibly fixing,
and checking in the GET-MACRO-CHARACTER stuff I can try fixing COMPILE
bug along the lines you suggest.

Thank you.

-- 
William Harold Newman <wil...@ai...>
"Palantir great. Better than cable."
  -- <http://home.nyu.edu/~amw243/diaries/saruman.html>
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