Re: Fwd: Getting AC_PROG_CC_C99

[Paul Eggert]

On 09/28/11 01:52, Gary V. Vaughan wrote:
> Might as well try to fix it right in gnulib though, and maybe in autoconf
>> too if the latest release hasn't made it multi-call safe yet.

The simplest fix would be something like the patch at the end of
this message.  This matches common practice anyway; and if an
application mistakenly omits the AC_PROG_CC_STDC there
shouldn't be much of a problem in practice I expect.

Another possibility would be for gnulib to redefine
AC_PROG_CC_STDC so that it acts only once.  That'd be more work,
though.

We could also look into fixing autoconf, but that would take longer
and be trickier.  I briefly discussed this a few days ago, when
talking about the declaration-after-statement issue
<http://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00367.html>.

diff --git a/modules/stdarg b/modules/stdarg                                    
index 84d3e7b..ab3436e 100644                                                   
--- a/modules/stdarg                                                            
+++ b/modules/stdarg                                                            
@@ -13,7 +13,9 @@ dnl Some compilers (e.g., AIX 5.3 cc) need to be in c99 mode
 dnl for the builtin va_copy to work.  With Autoconf 2.60 or later,             
 dnl AC_PROG_CC_STDC arranges for this.  With older Autoconf AC_PROG_CC_STDC    
 dnl shouldn't hurt, though installers are on their own to set c99 mode.        
-AC_REQUIRE([AC_PROG_CC_STDC])                                                  
+dnl                                                                            
+dnl It is the package's responsibility to invoke AC_PROG_CC_STDC early on,     
+dnl before gl_EARLY.                                                           
                                                                                
 configure.ac:                                                                  
 gl_STDARG_H