PKGBUILDs/extra/pipewire/0001-atomic.patch

From ff849ed1b0d254afa4dd591ca01d8d74c03344ec Mon Sep 17 00:00:00 2001
From: Kevin Mihelich <kevin@archlinuxarm.org>
Date: Wed, 11 Mar 2020 07:28:28 -0600
Subject: [PATCH] atomic

---
 pipewire-jack/src/meson.build | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/pipewire-jack/src/meson.build b/pipewire-jack/src/meson.build
index a052eaa8..1f08f0a5 100644
--- a/pipewire-jack/src/meson.build
+++ b/pipewire-jack/src/meson.build
@@ -33,13 +33,34 @@ configure_file(input : 'pw-jack.in',
                configuration : tools_config,
                install_dir : pipewire_bindir)
 
+# Check for GCC style atomics
+dep_atomic = declare_dependency()
+
+if cc.compiles('int main() { int n; return __atomic_load_n(&n, __ATOMIC_ACQUIRE); }',
+               name : 'GCC atomic builtins')
+  # Not all atomic calls can be turned into lock-free instructions, in which
+  # GCC will make calls into the libatomic library. Check whether we need to
+  # link with -latomic.
+  #
+  # This can happen for 64-bit atomic operations on 32-bit architectures such
+  # as ARM.
+  if not cc.links('''#include <stdint.h>
+                     int main() {
+                       uint64_t n;
+                       return (int)__atomic_load_n(&n, __ATOMIC_ACQUIRE);
+                     }''',
+                  name : 'GCC atomic builtins required -latomic')
+    dep_atomic = cc.find_library('atomic')
+  endif
+endif
+
 pipewire_jack = shared_library('jack',
     pipewire_jack_sources,
     soversion : soversion,
     version : libversion,
     c_args : pipewire_jack_c_args,
     include_directories : [configinc],
-    dependencies : [pipewire_dep, jack_dep, mathlib],
+    dependencies : [pipewire_dep, jack_dep, mathlib, dep_atomic],
     install : true,
     install_dir : libjack_path,
 )
-- 
2.26.2