Allow stdatomic.h to be included from mingw prebuilt.

Define __GNUC_PREREQ if it isn't already defined.
This is a bit ugly, but it seems to be easiest to make this header as
context-independent as possible.  Together with the addition of a symbolic
link to this file from the mingw prebuilt, this appears to unblock
commit e9fa6be333e35d9e7ae435aeb32532875b95fe22.

Change-Id: I97e39cda8d8f9aa108aa61c4121da09eb9739062

diff --git a/libc/include/stdatomic.h b/libc/include/stdatomic.h
index 58cb1bc0e183af3460b3e8b293827371b8d04b64..2c4f1ce30f012ad84363cc2d2e7bc00c4de92d01 100644 (file)
--- a/libc/include/stdatomic.h
+++ b/libc/include/stdatomic.h
@@ -32,6 +32,12 @@
 
 #include <sys/cdefs.h>
 
+#if defined(__GNUC__) && !defined(__GNUC_PREREQ)
+/* Duplicate definition here, since the mingw sys/cdefs.h omits the  */
+/* definition, and this needs to be usable there.                    */
+#define        __GNUC_PREREQ(x, y)    \
+       ((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) || (__GNUC__ > (x)))
+#endif /* __GNUC__ && ... */
 
 #if defined(__cplusplus) && __cplusplus >= 201103L && defined(_USING_LIBCXX)
 # ifdef __clang__