On Wed, May 8, 2013 at 1:17 AM, Allan McRae <al...@archlinux.org> wrote: > Our distribution packages are compiled with: > > CPPFLAGS="-D_FORTIFY_SOURCE=2" > CFLAGS="-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector > --param=ssp-buffer-size=4" > > So when both CPPFLAGS and CFLAGS are passed there is no issue.
I think the quick fix from your end is to move -D_FORTIFY_SOURCE to CFLAGS (and presumably also CXXFLAGS). Despite being a -D switch its *effect* is much more like an -m or -f switch, so I don't think this is even technically wrong, and it'll have the results you need. > I have not looked into this in great detail yet, but it seems some > configure scripts have this in them: > > ac_cpp='$CPP $CPPFLAGS' > > and this is used to test for header presence. Note I said some > configure scripts - I have not figured out why others do not use > CPPFLAGS in this test. The low-hanging fruit here is AC_CHECK_HEADER, which currently by default does a "double check" for the presence of a header, one of them using only CPPFLAGS. Some extra-diligent projects have switched over to doing only a compile check. I have patches mostly written that will make the default be compile-only. However, anyone that deliberately uses AC_PREPROC_IFELSE or similar will still have the problem. >>> recent versions of glibc produces a >>> warning when it compiles apps with _FORTIFY_SOURCE but without -O2 >> >> That's a real problem, which will break lots of things. >> Fix that, and your Autoconf issue will go away. > > I don't agree that the glibc warning is an issue. Unless you use > -Werror (bad) or check for any warning rather than a specific one. Autoconf can't check for specific warnings because it has no way of knowing how the compiler in use will react to any given (potential) problem. I note that Debian has patched this warning out of their (just now appeared in unstable) glibc 2.17. See http://anonscm.debian.org/viewvc/pkg-glibc/glibc-package/trunk/debian/patches/any/local-revert-bz13979.diff?revision=5553&view=markup zw _______________________________________________ Autoconf mailing list Autoconf@gnu.org https://lists.gnu.org/mailman/listinfo/autoconf
