fix atomic detection on older gcc versions

GLib checks for __sync_bool_compare_and_swap, and requires
__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 to be defined if the function is available,
except with special cases like Linux armv5.
Extend the existing workaround to unbreak on old gcc versions that implement
__sync_bool_compare_and_swap but don't provide __GCC_HAVE_* macros.
This commit is contained in:
Antoine Jacoutot 2019-07-14 19:25:28 +02:00
parent d56bdeb926
commit a76cb94308

View File

@ -1597,8 +1597,8 @@ atomicdefine = '''
# We know that we can always use real ("lock free") atomic operations with MSVC # We know that we can always use real ("lock free") atomic operations with MSVC
if cc.get_id() == 'msvc' or cc.links(atomictest, name : 'atomic ops') if cc.get_id() == 'msvc' or cc.links(atomictest, name : 'atomic ops')
have_atomic_lock_free = true have_atomic_lock_free = true
if (host_system == 'android' or host_system == 'linux') and not cc.compiles(atomicdefine, name : 'atomic ops define') if cc.get_id() == 'gcc' and not cc.compiles(atomicdefine, name : 'atomic ops define')
# When building for armv5 on Linux, gcc provides # Old gcc release may provide
# __sync_bool_compare_and_swap but doesn't define # __sync_bool_compare_and_swap but doesn't define
# __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 # __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
glib_conf.set('__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4', true) glib_conf.set('__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4', true)