http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47558
--- Comment #38 from Jack Howarth <howarth at nitro dot med.uc.edu> 2011-02-04 01:20:05 UTC --- Actually, I think I see the problem here. Looking at how gcc-4.2 in Snow Leopard links, I see... gcc -v himenoBMTxpa.c ... /usr/libexec/gcc/i686-apple-darwin10/4.2.1/collect2 -dynamic -arch x86_64 -macosx_version_min 10.6.7 -weak_reference_mismatches non-weak -o a.out -lcrt1.10.6.o -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/x86_64 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/x86_64 -L/usr/lib/i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../.. /var/folders/1C/1CdoNxmNFHyOIjNBLNuJh++++TM/-Tmp-//ccbmcsLd.o -lSystem -lgcc -lSystem whereas for current gcc trunk we have... /Users/howarth/dist/libexec/gcc/x86_64-apple-darwin10.7.0/4.6.0/collect2 -dynamic -arch x86_64 -macosx_version_min 10.6.7 -weak_reference_mismatches non-weak -o a.out -lcrt1.10.5.o -L/Users/howarth/dist/lib/gcc/x86_64-apple-darwin10.7.0/4.6.0 -L/Users/howarth/dist/lib/gcc/x86_64-apple-darwin10.7.0/4.6.0/../../.. /var/folders/1C/1CdoNxmNFHyOIjNBLNuJh++++TM/-Tmp-//ccZYYQup.o -lgcc_ext.10.5 -lgcc -no_compact_unwind -lSystem -v So we get the wrong unwinder in xplor-nih with -flat_namepace because, while libgcc_ext.10.5.dylib doesn't export the unwinder symbols, -lgcc will cause /Users/howarth/dist/lib/gcc/x86_64-apple-darwin10.7.0/4.6.0/libgcc.a to provide them. In particular, I see the symbol for ___enable_execute_stack in the FSF libgcc.a. So what we should do is insure that FSF gcc 4.6 produces the same sort of linkage as Apple's gcc-4.2. That is... -lgcc_ext.10.5 -lSystem -lgcc -no_compact_unwind -lSystem This would avoid the need for reverting r163267. ps If I recall correctly, the Apple developers told me that they do eventually intend to get rid of the linkage on -lgcc. Maybe that will happen in 10.7.
