Re: documentation of AC_FUNC_ALLOCA and mingw-w64 compilers

[Vincent Torri]

On Sun, 22 Jan 2012, Paul Eggert wrote:

> On 01/22/2012 04:17 AM, Vincent Torri wrote:
> > 2) the MinGW-w64 compiler already defines alloca in malloc.h,
> > that header files being included by stdlib.h because STDC_HEADERS is defined.
>
> Could you give more details about the problem?
> STDC_HEADERS is in the user's space, so the system
> stdlib.h should be unaffected by whether STDC_HEADERS
> is defined.  Are we talking about the system's stdlib.h
> here, or by your own substitute for stdlib.h?  If the
> latter, then it might be something outside the
> scope of the autoconf documentation.

there was a warning when using mingw-w64 compilers : redefinition of 
alloca. The line where the redefinition is located is:

#elif defined __GNUC__
# define alloca __builtin_alloca   <---- that one

and there was a redefinition because stdlib.h is included just above, and 
stdlib.h includes malloc.h. And with mingw-w64 compilers, malloc.h 
already defines alloca.

I hope I'm clearer :)

Vincent Torri