http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55061
--- Comment #21 from Jack Howarth <howarth at nitro dot med.uc.edu> 2012-10-25 19:57:29 UTC --- FYI the test in Comment 20 passes for llvm-gcc-4.2 and clang in Xcode 4.5.1 but only for gcc-4.2 and llvm-gcc-4.2 in Xcode 4.2. The clang in Xcode 4.2 apparently doesn't provide the unwind.h header yet... % clang -Werror-implicit-function-declaration -c test.c test.c:1:10: fatal error: 'unwind.h' file not found #include "unwind.h" ^ 1 error generated.