index 47b333cf17594438fc212cbbd3b2b3c33ea5c11c..2c4f1ce30f012ad84363cc2d2e7bc00c4de92d01 100644 (file)
--- a/libc/include/stdatomic.h
+++ b/libc/include/stdatomic.h
#include <sys/cdefs.h>
-#if defined(__cplusplus) && defined(_USING_LIBCXX) && \
- (__has_feature(cxx_atomic) || _GNUC_VER >= 407)
+#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__
+# if __has_feature(cxx_atomic)
+# define _STDATOMIC_HAVE_ATOMIC
+# endif
+# else /* gcc */
+# if __GNUC_PREREQ(4, 7)
+# define _STDATOMIC_HAVE_ATOMIC
+# endif
+# endif
+#endif
+
+#ifdef _STDATOMIC_HAVE_ATOMIC
/* We have a usable C++ <atomic>; use it instead. */
/* included. The definitions in <atomic> themselves see */
/* the old definition, as they should. */
/* Client code sees the following definition. */
+
#define _Atomic(t) std::atomic<t>
using std::atomic_is_lock_free;
using std::memory_order;
using std::memory_order_relaxed;
using std::memory_order_consume;
+using std::memory_order_acquire;
using std::memory_order_release;
using std::memory_order_acq_rel;
using std::memory_order_seq_cst;
# include <uchar.h> /* For char16_t and char32_t. */
#endif
-#if __has_extension(c_atomic) || __has_extension(cxx_atomic)
-#define __CLANG_ATOMICS
-#elif __GNUC_PREREQ(4, 7)
-#define __GNUC_ATOMICS
-#elif defined(__GNUC__)
-#define __SYNC_ATOMICS
+#ifdef __clang__
+# if __has_extension(c_atomic) || __has_extension(cxx_atomic)
+# define __CLANG_ATOMICS
+# else
+# error "stdatomic.h does not support your compiler"
+# endif
+# if __has_builtin(__sync_swap)
+# define __HAS_BUILTIN_SYNC_SWAP
+# endif
#else
-#error "stdatomic.h does not support your compiler"
+# if __GNUC_PREREQ(4, 7)
+# define __GNUC_ATOMICS
+# else
+# define __SYNC_ATOMICS
+# ifdef __cplusplus
+# define __ATOMICS_AVOID_DOT_INIT
+# endif
+# endif
#endif
/*
#ifdef __GCC_ATOMIC_BOOL_LOCK_FREE
#define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_BOOL_LOCK_FREE 2 /* For all modern platforms */
#endif
#ifdef __GCC_ATOMIC_CHAR_LOCK_FREE
#define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_CHAR_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_CHAR16_T_LOCK_FREE
#define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_CHAR16_T_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_CHAR32_T_LOCK_FREE
#define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_CHAR32_T_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_WCHAR_T_LOCK_FREE
#define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_WCHAR_T_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_SHORT_LOCK_FREE
#define ATOMIC_SHORT_LOCK_FREE __GCC_ATOMIC_SHORT_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_SHORT_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_INT_LOCK_FREE
#define ATOMIC_INT_LOCK_FREE __GCC_ATOMIC_INT_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_INT_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_LONG_LOCK_FREE
#define ATOMIC_LONG_LOCK_FREE __GCC_ATOMIC_LONG_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_LONG_LOCK_FREE 2
#endif
#ifdef __GCC_ATOMIC_LLONG_LOCK_FREE
#define ATOMIC_LLONG_LOCK_FREE __GCC_ATOMIC_LLONG_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_LLONG_LOCK_FREE 1 /* maybe */
#endif
#ifdef __GCC_ATOMIC_POINTER_LOCK_FREE
#define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE
+#elif defined(__SYNC_ATOMICS)
+#define ATOMIC_POINTER_LOCK_FREE 2
#endif
/*
#define ATOMIC_VAR_INIT(value) (value)
#define atomic_init(obj, value) __c11_atomic_init(obj, value)
#else
+#ifdef __ATOMICS_AVOID_DOT_INIT
+#define ATOMIC_VAR_INIT(value) { value }
+#else
#define ATOMIC_VAR_INIT(value) { .__val = (value) }
+#endif
#define atomic_init(obj, value) ((void)((obj)->__val = (value)))
#endif
* 7.17.6 Atomic integer types.
*/
-#if !__has_extension(c_atomic) && !__has_extension(cxx_atomic)
+#ifndef __CLANG_ATOMICS
/*
* No native support for _Atomic(). Place object in structure to prevent
* most forms of direct non-atomic access.
desired, success, failure) \
atomic_compare_exchange_strong_explicit(object, expected, \
desired, success, failure)
-#if __has_builtin(__sync_swap)
+#ifdef __HAS_BUILTIN_SYNC_SWAP
/* Clang provides a full-barrier atomic exchange - use it if available. */
#define atomic_exchange_explicit(object, desired, order) \
((void)(order), __sync_swap(&(object)->__val, desired))