[PATCH i-g-t v3 1/4] meson: add libatomic dependency

Guillaume Tucker
2019-06-18T12:27:43Z

Add conditional dependency on libatomic in order to be able to use the
__atomic_* functions instead of the older __sync_* ones. The
libatomic library is only needed when there aren't any native support
on the current architecture, so a linker test is used for this
purpose. This enables atomic operations to be on a wider number of
architectures including MIPS.

Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
---

Notes:
v2: add linker test for libatomic
v3: use null_dep

meson.build | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/meson.build b/meson.build
index 6268c58d3634..118ad667ffb5 100644
--- a/meson.build
+++ b/meson.build
@@ -180,6 +180,20 @@ realtime = cc.find_library('rt')
dlsym = cc.find_library('dl')
zlib = cc.find_library('z')

+if cc.links('''
+#include <stdint.h>
+int main(void) {
+ uint32_t x32 = 0;
+ uint64_t x64 = 0;
+ __atomic_load_n(&x32, __ATOMIC_SEQ_CST);
+ __atomic_load_n(&x64, __ATOMIC_SEQ_CST);
+ return 0;
+}''', name : 'built-in atomics')
+ libatomic = null_dep
+else
+ libatomic = cc.find_library('atomic')
+endif
+
if cc.has_header('linux/kd.h')
config.set('HAVE_LINUX_KD_H', 1)
endif
--
2.20.1