Re: gcc-4.3, glibc and AC_PROG_CC_STDC

[Paul Eggert]

I am CC'ing this message to address@hidden to give GCC developers a
heads-up on the situation.  For GCC developers: please see
<http://lists.gnu.org/archive/html/bug-gnulib/2007-02/msg00106.html>
for the problem with a gcc-4.3 snapshot with --std=gnu99 -O2" and
glibc wchar.h.

Ralf Wildenhues <address@hidden> writes:

> Given that there is still discussion and work on GCC for this topic
> anyway[1], I don't think Autoconf should be doing anything just yet.

Both of the solutions that Bruno suggested seem too drastic to me as
well.  I hope we can come up with something less intrusive.

Once GCC 4.3 settles down, perhaps we can work around any remaining
problems with gnulib's wchar module.

A less-appetizing possibility would be to modify AC_PROG_CC_STDC to
specify --std=gnu99 -fgnu89-extern-inline rather than plain
--std=gnu99 if 'configure' detects the problem with wchar.h, or with
any other standard include file.  Presumably this would occur only if
GCC 4.3 (or 4.4?) is used with an older glibc.  But for this case I'm
inclined to ask, along with Ralf, why GCC 4.3 doesn't apply
fixincludes to the troublesome include files.

> If the absolute header inclusion technique employed by gnulib is
> preventing the fixinclude thingy to work,

That should not be a problem.  gnulib's absolute header method should
work even when fixincludes has generated the include file.  (I haven't
tested this, though.)