configure.ac/meson.build: Fix -latomic test
When compiling with LLVM 6.0 on x86 (32-bit) for Android, the test
fails to detect that -latomic is actually required, as the atomic
call is inlined.
In the code itself (src/util/disk_cache.c), we see this pattern:
p_atomic_add(cache->size, - (uint64_t)size);
where cache->size is an uint64_t *, and results in the following
link time error without -latomic:
src/util/disk_cache.c:628: error: undefined reference to '__atomic_fetch_add_8'
Fix the configure/meson test to replicate this pattern, which then
correctly realizes the need for -latomic.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
diff --git a/meson.build b/meson.build
index 6e61766..e52b4a5 100644
--- a/meson.build
+++ b/meson.build
@@ -849,8 +849,10 @@
# as ARM.
if not cc.links('''#include <stdint.h>
int main() {
- uint64_t n;
- return (int)__atomic_load_n(&n, __ATOMIC_ACQUIRE);
+ struct {
+ uint64_t *v;
+ } x;
+ return (int)__atomic_load_n(x.v, __ATOMIC_ACQUIRE);
}''',
name : 'GCC atomic builtins required -latomic')
dep_atomic = cc.find_library('atomic')