build: always require atomics

Always require them, instead of just for some components which have hard
requirements on correct atomic semantics. They should be widely
available, and are supported by all recent gcc and clang compiler
versions. We even have the fallbacks builtins, which should keep this
working on very old gcc releases.

In particular, w32_common.c recently added a hard requirement on
atomics, but checking this properly in the build system would have been
messy. This commit makes sure it always works.

The fallback where weak atomic semantics are always fine is in theory
rather questionable as well.

1 files changed, 2 insertions, 5 deletions

diff --git a/wscript b/wscript
index 309efd3bb2..a18df6f581 100644
--- a/wscript
+++ b/wscript
@@ -175,6 +175,7 @@ main_dependencies = [
         'name': 'atomics',
         'desc': 'compiler support for usable thread synchronization built-ins',
         'func': check_true,
+        'req': True,
         'deps_any': ['stdatomic', 'atomic-builtins', 'sync-builtins'],
     }, {
         'name': 'c11-tls',
@@ -517,13 +518,11 @@ audio_output_features = [
     {
         'name': '--sdl2',
         'desc': 'SDL2',
-        'deps': ['atomics'],
         'func': check_pkg_config('sdl2'),
         'default': 'disable'
     }, {
         'name': '--sdl1',
         'desc': 'SDL (1.x)',
-        'deps': ['atomics'],
         'deps_neg': [ 'sdl2' ],
         'func': check_pkg_config('sdl'),
         'default': 'disable'
@@ -574,7 +573,6 @@ audio_output_features = [
     }, {
         'name': '--jack',
         'desc': 'JACK audio output',
-        'deps': ['atomics'],
         'func': check_pkg_config('jack'),
     }, {
         'name': '--openal',
@@ -592,14 +590,13 @@ audio_output_features = [
     }, {
         'name': '--coreaudio',
         'desc': 'CoreAudio audio output',
-        'deps': ['atomics'],
         'func': check_cc(
             fragment=load_fragment('coreaudio.c'),
             framework_name=['CoreFoundation', 'CoreAudio', 'AudioUnit', 'AudioToolbox'])
     }, {
         'name': '--wasapi',
         'desc': 'WASAPI audio output',
-        'deps': ['win32', 'atomics'],
+        'deps': ['win32'],
         'func': check_cc(fragment=load_fragment('wasapi.c')),
     }
 ]