[PATCH] Serious problem with Autoconf on RedHat 7

[Morten Eriksen]

Hi,

I don't know if this mail got through without losing a few electrons
due to the recent mailinglist hickups, so I'm resending it. With a
patch this time, so it might be easier to get it applied.  :^}

2000-10-02 Morten Eriksen <address@hidden>

        * aclang.m4 (AC_LANG_SOURCE(C++)): don't define exit(), it'll
        mismatch with the native exit() definition on some platforms
        (happens at least with g++ 2.96 and glibc 2.1.92 on Red Hat Linux
        v7).


Regards,
Morten

try_compile_cpp.diff
Description: Text document

> --- Begin Message ---
>
>
>
> Subject: 
>
> Serious problem with Autoconf on RedHat 7
>
>
>
>
> Date: 
>
> 29 Sep 2000 18:17:09 +0200
>
>
>
>
> User-agent: 
>
> Gnus/5.070098 (Pterodactyl Gnus v0.98) Emacs/20.3
>
>
>
>
> Hi,
>
> I just discovered a nasty problem with the latest CVS Autoconf on Red
> Hat Linux v7 (default setup, i.e. with g++ 2.96). In short, the
> AC_TRY_COMPILE in the configure.in script below will fail:
>
> ->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--
>
> AC_INIT(configure.in)
> AC_LANG_CPLUSPLUS
> AC_TRY_COMPILE([#include <stdlib.h>], [], , AC_MSG_ERROR(sorr-ee))
> AC_OUTPUT()
>
> ->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--
>
> Here's the relevant part of config.log:
>
> ->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--
>
> [...]
> configure:1141: g++ -c -g -O2  conftest.cpp >&5
> In file included from configure:1135:
> /usr/include/stdlib.h:578: declaration of `void exit (int) throw ()' 
> throws different exceptions
> configure:1132: than previous declaration `void exit (int)'
> configure: failed program was:
> #line 1130 "configure"
> #include "confdefs.h"
> #ifdef __cplusplus
> extern "C" void exit (int);
> #endif
> #include <stdlib.h>
> int
> main ()
> {
>
>   ;
>   return 0;
> }
>
> ->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--->8-->8--
>
> Now, this is obviously due to the "extern" forward declaration of
> exit() not matching the exit() defined by the stdlib.h of GCC 2.96
> when run as a C++ compiler.
>
> Why is the explicit exit() declaration there anyway? Removing it will
> of course make the configure script run correctly.
>
> Regards,
> Morten
>
>
> --- End Message ---