Avoid including alMain.h in ringbuffer.c

1 files changed, 13 insertions, 0 deletions

diff --git a/common/atomic.h b/common/atomic.h
index 874d510d..2033476b 100644
--- a/common/atomic.h
+++ b/common/atomic.h
@@ -4,6 +4,19 @@
 #include "static_assert.h"
 #include "bool.h"
 
+#ifdef __GNUC__
+/* This helps cast away the const-ness of a pointer without accidentally
+ * changing the pointer type. This is necessary due to Clang's inability to use
+ * atomic_load on a const _Atomic variable.
+ */
+#define CONST_CAST(T, V) __extension__({                                      \
+    const T _tmp = (V);                                                       \
+    (T)_tmp;                                                                  \
+})
+#else
+#define CONST_CAST(T, V) ((T)(V))
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif