On 3 November 2015 at 20:43, John Snow <js...@redhat.com> wrote: > Some versions of clang may have difficulty compiling glibc headers when > -D_FORTIFY_SOURCE is used. For example, Clang++ 3.5.0-9.fc22 cannot > compile glibc's stdio headers when -D_FORTIFY_SOURCE=2 is used. This > manifests currently as build failures with clang and any arm target. > > According to LLVM dev Richard Smith, clang does not target or support > FORTIFY_SOURCE + glibc, and it should not be relied on. > "It's still an unsupported combination, and while it might compile, some > of the checks are unlikely to work because they require a frontend > inliner to be useful" > > See: http://lists.llvm.org/pipermail/cfe-dev/2015-November/045846.html > > Conclusion: disable fortify-source if we appear to be using clang instead > of testing for compile success or failure, which may be incidental or not > indicative of proper support of the feature.
> ########################################## > # End of CC checks > # After here, no more $cc or $ld runs > @@ -4442,7 +4457,7 @@ fi > if test "$gcov" = "yes" ; then > CFLAGS="-fprofile-arcs -ftest-coverage -g $CFLAGS" > LDFLAGS="-fprofile-arcs -ftest-coverage $LDFLAGS" > -elif test "$debug" = "no" ; then > +elif test "$fortify_source" = "yes" ; then > CFLAGS="-O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 $CFLAGS" > fi This change means that a non-debug build with clang will no longer pass -O2 in the CFLAGS, so you get an unoptimized build... You need to handle fortify_source=yes and debug=no separately. thanks -- PMM
