Hi, I'm trying to build the libunwind v1.4-stable branch on a RHEL 6.5 ppc64 system. The compiler is: gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4). Here's the error:
libtool: compile: /usr/bin/gcc -fsigned-char -m64 -Wl,--as-needed -g -DHAVE_CONFIG_H -I. -I../../LIBUnwind/src -I../include -I../../LIBUnwind/include -I../../LIBUnwind/include/tdep-ppc64 -I. -D_GNU_SOURCE -DDEBUG -fexceptions -Wall -Wsign-compare -MT dwarf/Lparser.lo -MD -MP -MF dwarf/.deps/Lparser.Tpo -c ../../LIBUnwind/src/dwarf/Lparser.c -fPIC -DPIC -o dwarf/.libs/Lparser.o In file included from ../../LIBUnwind/src/dwarf/Lparser.c:4: ../../LIBUnwind/src/dwarf/Gparser.c: In function 'get_rs_cache': ../../LIBUnwind/src/dwarf/Gparser.c:613: warning: implicit declaration of function '__atomic_load_n' ../../LIBUnwind/src/dwarf/Gparser.c:613: error: '__ATOMIC_RELAXED' undeclared (first use in this function) ../../LIBUnwind/src/dwarf/Gparser.c:613: error: (Each undeclared identifier is reported only once ../../LIBUnwind/src/dwarf/Gparser.c:613: error: for each function it appears in.) I'm not sure what is the "right" way to fix this, but the following change seems to allow it to compile: diff --git a/3rdparty/libunwind/LIBUnwind/include/libunwind_i.h b/3rdparty/libunwind/LIBUnwind/include/libunwind_i.h index e0f4540..09356b2 100644 --- a/3rdparty/libunwind/LIBUnwind/include/libunwind_i.h +++ b/3rdparty/libunwind/LIBUnwind/include/libunwind_i.h @@ -165,7 +165,11 @@ cmpxchg_ptr (void *addr, void *old, void *new) } # define fetch_and_add1(_ptr) __sync_fetch_and_add(_ptr, 1) # define fetch_and_add(_ptr, value) __sync_fetch_and_add(_ptr, value) -# define atomic_read(ptr) (__atomic_load_n(ptr,__ATOMIC_RELAXED)) +# if defined(__ATOMIC_RELAXED) +# define atomic_read(ptr) (__atomic_load_n(ptr,__ATOMIC_RELAXED)) +# else +# define atomic_read(ptr) (__sync_fetch_and_add(ptr, 0)) +# endif # define HAVE_CMPXCHG # define HAVE_FETCH_AND_ADD #endif AFAIK, adding 0 to *ptr with __sync_fetch_and_add() should be equivalent to __atomic_load_n(), and more portable because the code already uses __sync_fetch_and_add() just a few lines above. Does that change look OK or is something different needed? Should I file a bug report or is RHEL 6.5 no longer supported? Thanks, John D.
