Hello, * Eric Blake wrote on Thu, Aug 07, 2008 at 03:20:53AM CEST: > According to Bruno Haible on 8/6/2008 4:41 PM: > | Could this be made customizable somehow? Either through a variable that the > | developer could set in his configure.ac before the invocation of AC_PROG_CC, > | or through a macro which he could redefine in his configure.ac? > > Hmm. This is an interesting request, and seems doable. I think it would > be reasonable to see this in the user's configure.ac, just prior to > AC_PROG_CC: > > AC_PROG_GCC_DEFAULT_FLAGS([-O2 -g -Wall])
> at which point, that string becomes the first set of CFLAGS tried for the > compiler (if $CFLAGS is undefined), before falling back on "-g -O2" if it > didn't work. Oh, the ugliness of checking compiler flags. One interesting aspect of implementing this is that the next GCC version will ignore and may warn but will not fail upon unknown -Wno-* flags. [1] Coping with this nicely in such a test isn't exactly trivial; as first approximation, one could just ignore that issue. Of course, there are other compilers that even ignore all kinds of unknown switches (but do warn about them). > Anyone care to contribute a patch, even if only to add a line in the TODO > file pointing to this thread? I've pushed the patch below. Cheers, Ralf [1] <http://thread.gmane.org/gmane.comp.gcc.patches/164070/focus=164077> 2008-08-21 Ralf Wildenhues <[EMAIL PROTECTED]> * TODO: Add item for compiler default flags. Suggested by Bruno Haible. diff --git a/TODO b/TODO index 6993dce..368268c 100644 --- a/TODO +++ b/TODO @@ -42,6 +42,10 @@ even if they are slightly incompatible with C99. The basic idea here is that AC_PROG_CC should disable pedanticisms and should enable extensions. +Have a way to specify different default flags to try; see this thread +for more information: +<http://lists.gnu.org/archive/html/bug-autoconf/2008-08/msg00009.html>. + * Later
