Revision 192853 added a new test for availability of _Unwind_GetIPInfo in the system unwinder to the configure script of libbacktrace: http://repo.or.cz/w/official-gcc.git/commitdiff/a4a5a77adfc9c28d6963e5ae054c997d57cfc7fa It was apparently added to fix a bug building with GCC 4.0 on Mac OS X 10.5.
This is one of a few checks for that function (there's also one in the top-level configure script). Unfortunately, while the other tests have special handling for Mac OS X 10.4, this new test does not take it into account. In 10.4, _Unwind_GetIPInfo is not exported in the system unwinder. Trying to build a test program will succeed, but will fail to link due to the symbol being undefined. The test added to libbacktrace's configure used AC_COMPILE_IFELSE, which meant it didn't try to link and erroneously flagged _Unwind_GetIPInfo as usable. This led to build errors when linking. This small patch changes configure to use AC_LINK_IFELSE, which fixes the issue on OS X 10.4. I've been able to build GCC successfully. GCC 4.8 and 4.9 are affected by this issue. A bug report is filed for this as #58710 (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58710). diff --git libbacktrace/configure.ac libbacktrace/configure.ac index 28b2a1c..e0e0e08 100644 --- libbacktrace/configure.ac +++ libbacktrace/configure.ac @@ -144,7 +144,7 @@ else ac_save_CFFLAGS="$CFLAGS" CFLAGS="$CFLAGS -Werror-implicit-function- declaration" AC_MSG_CHECKING([for _Unwind_GetIPInfo]) - AC_COMPILE_IFELSE( + AC_LINK_IFELSE( [AC_LANG_PROGRAM( [#include "unwind.h" struct _Unwind_Context *context;
