In testing build patches for gcc 4.8 to allow darwin to have asan support,
I ran across a defect in mach_override/mach_override.c...
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55289#c27
which was solved with the patch proposed by Alexander Potapenko in...
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55289#c29
Index: mach_override.c