On Fri, Feb 7, 2014 at 9:06 AM, Misty De Meo <mistyde...@gmail.com> wrote: > 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;
This is OK with a ChangeLog entry for 4.8 branch and mainline. Thanks. Ian
