bin/contrib/memaslap: attempt to fix atomics detection

[awesomized/libmemcached] / CMake / CheckAtomics.cmake

diff --git a/CMake/CheckAtomics.cmake b/CMake/CheckAtomics.cmake
new file mode 100644 (file)
index 0000000..9d12276
--- /dev/null
+++ b/CMake/CheckAtomics.cmake
@@ -0,0 +1,58 @@
+include(CheckCSourceRuns)
+include(CheckCXXSourceRuns)
+
+# sets HAVE_ATOMICS, checks for :
+# - C++11 std::atomic:  HAVE_CXX_STDATOMIC
+# - C11 stdatomic:      HAVE_C_STDATOMIC
+# - builtin __atomic:   HAVE_BUILTIN_ATOMIC
+# - builtin __sync:     HAVE_BUILTIN_SYNC
+# - atomic_add_nv:      HAVE_ATOMIC_ADD_NV
+function(check_atomics)
+    check_cxx_source_runs("
+            #include <atomic>
+            int main() {
+                std::atomic<int> i(0);
+                return atomic_load(&i);
+            }"
+            HAVE_CXX_STDATOMIC)
+    check_c_source_runs("
+            #include <stdatomic.h>
+            int main() {
+                atomic_int i;
+                atomic_init(&i, 0);
+                return atomic_load(&i);
+            }"
+            HAVE_C_STDATOMIC)
+    foreach(BUILTIN_ATOMIC_PREFIX IN ITEMS _ __c11)
+        check_c_source_runs("
+                int main() {
+                    long l = 0;
+                    return ${BUILTIN_ATOMIC_PREFIX}_atomic_add_fetch(&l,1,__ATOMIC_RELAXED);
+                }"
+                HAVE_BUILTIN_ATOMIC${BUILTIN_ATOMIC_PREFIX})
+        if (HAVE_BUILTIN_ATOMIC${BUILTIN_ATOMIC_PREFIX})
+            set(HAVE_BUILTIN_ATOMIC 1)
+            break()
+        endif()
+    endforeach()
+    check_c_source_runs("
+            int main() {
+                long l = 0;
+                return __sync_add_and_fetch(&l,1);
+            }"
+            HAVE_BUILTIN_SYNC)
+    check_c_source_runs("
+            #include <atomic.h>
+            int main() {
+                volatile uint_t i = 0;
+                return atomic_add_int_nv(&i, 1);
+            }"
+            HAVE_ATOMIC_ADD_NV)
+    if (        HAVE_CXX_STDATOMIC
+            OR  HAVE_C_STDATOMIC
+            OR  HAVE_BUILTIN_ATOMIC
+            OR  HAVE_BUILTIN_SYNC
+            OR  HAVE_ATOMIC_ADD_NV)
+        set(HAVE_ATOMICS 1 PARENT_SCOPE)
+    endif()
+endfunction()