On 03/11/2015 21:43, John Snow 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. > > Signed-off-by: John Snow <js...@redhat.com> > --- > configure | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/configure b/configure > index 7a1d08d..4d74fcc 100755 > --- a/configure > +++ b/configure > @@ -261,6 +261,7 @@ rdma="" > gprof="no" > debug_tcg="no" > debug="no" > +fortify_source="" > strip_opt="yes" > tcg_interpreter="no" > bigendian="no" > @@ -876,6 +877,7 @@ for opt do > debug_tcg="yes" > debug="yes" > strip_opt="no" > + fortify_source="no" > ;; > --enable-sparse) sparse="yes" > ;; > @@ -4435,6 +4437,19 @@ if ! compile_object "-Werror"; then > ccache_cpp2=yes > fi > > +################################################# > +# clang does not support glibc + FORTIFY_SOURCE. > + > +if test "$fortify_source" != "no"; then > + if echo | $cc -dM -E - | grep __clang__ > /dev/null 2>&1 ; then > + fortify_source="no"; > + elif echo | $cxx -dM -E - | grep __clang__ > /dev/null 2>&1 ; then > + fortify_source="no"; > + else > + fortify_source="yes" > + fi > +fi > + > ########################################## > # 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 > >
Queued, thanks! Paolo
