clang/lib/Headers/stdatomic.h

   1 /*===---- stdatomic.h - Standard header for atomic types and operations -----===
   2  *
   3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4  * See https://llvm.org/LICENSE.txt for license information.
   5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6  *
   7  *===-----------------------------------------------------------------------===
   8  */
   9
  10 #ifndef __CLANG_STDATOMIC_H
  11 #define __CLANG_STDATOMIC_H
  12
  13 /* If we're hosted, fall back to the system's stdatomic.h. FreeBSD, for
  14  * example, already has a Clang-compatible stdatomic.h header.
  15  *
  16  * Exclude the MSVC path as well as the MSVC header as of the 14.31.30818
  17  * explicitly disallows `stdatomic.h` in the C mode via an `#error`.  Fallback
  18  * to the clang resource header until that is fully supported.  The
  19  * `stdatomic.h` header requires C++ 23 or newer.
  20  */
  21 #if __STDC_HOSTED__ &&                                                         \
  22     __has_include_next(<stdatomic.h>) &&                                       \
  23     (!defined(_MSC_VER) || (defined(__cplusplus) && __cplusplus >= 202002L))
  24 # include_next <stdatomic.h>
  25 #else
  26
  27 #include <stddef.h>
  28 #include <stdint.h>
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 /* 7.17.1 Introduction */
  35
  36 #define ATOMIC_BOOL_LOCK_FREE       __CLANG_ATOMIC_BOOL_LOCK_FREE
  37 #define ATOMIC_CHAR_LOCK_FREE       __CLANG_ATOMIC_CHAR_LOCK_FREE
  38 #define ATOMIC_CHAR16_T_LOCK_FREE   __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
  39 #define ATOMIC_CHAR32_T_LOCK_FREE   __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
  40 #define ATOMIC_WCHAR_T_LOCK_FREE    __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
  41 #define ATOMIC_SHORT_LOCK_FREE      __CLANG_ATOMIC_SHORT_LOCK_FREE
  42 #define ATOMIC_INT_LOCK_FREE        __CLANG_ATOMIC_INT_LOCK_FREE
  43 #define ATOMIC_LONG_LOCK_FREE       __CLANG_ATOMIC_LONG_LOCK_FREE
  44 #define ATOMIC_LLONG_LOCK_FREE      __CLANG_ATOMIC_LLONG_LOCK_FREE
  45 #define ATOMIC_POINTER_LOCK_FREE    __CLANG_ATOMIC_POINTER_LOCK_FREE
  46
  47 /* 7.17.2 Initialization */
  48 /* FIXME: This is using the placeholder dates Clang produces for these macros
  49    in C2x mode; switch to the correct values once they've been published. */
  50 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ < 202000L) ||               \
  51     defined(__cplusplus)
  52 /* ATOMIC_VAR_INIT was removed in C2x, but still remains in C++23. */
  53 #define ATOMIC_VAR_INIT(value) (value)
  54 #endif
  55
  56 #if ((defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201710L &&              \
  57       __STDC_VERSION__ < 202000L) ||                                           \
  58      (defined(__cplusplus) && __cplusplus >= 202002L)) &&                      \
  59     !defined(_CLANG_DISABLE_CRT_DEPRECATION_WARNINGS)
  60 /* ATOMIC_VAR_INIT was deprecated in C17 and C++20. */
  61 #pragma clang deprecated(ATOMIC_VAR_INIT)
  62 #endif
  63 #define atomic_init __c11_atomic_init
  64
  65 /* 7.17.3 Order and consistency */
  66
  67 typedef enum memory_order {
  68   memory_order_relaxed = __ATOMIC_RELAXED,
  69   memory_order_consume = __ATOMIC_CONSUME,
  70   memory_order_acquire = __ATOMIC_ACQUIRE,
  71   memory_order_release = __ATOMIC_RELEASE,
  72   memory_order_acq_rel = __ATOMIC_ACQ_REL,
  73   memory_order_seq_cst = __ATOMIC_SEQ_CST
  74 } memory_order;
  75
  76 #define kill_dependency(y) (y)
  77
  78 /* 7.17.4 Fences */
  79
  80 /* These should be provided by the libc implementation. */
  81 void atomic_thread_fence(memory_order);
  82 void atomic_signal_fence(memory_order);
  83
  84 #define atomic_thread_fence(order) __c11_atomic_thread_fence(order)
  85 #define atomic_signal_fence(order) __c11_atomic_signal_fence(order)
  86
  87 /* 7.17.5 Lock-free property */
  88
  89 #define atomic_is_lock_free(obj) __c11_atomic_is_lock_free(sizeof(*(obj)))
  90
  91 /* 7.17.6 Atomic integer types */
  92
  93 #ifdef __cplusplus
  94 typedef _Atomic(bool)               atomic_bool;
  95 #else
  96 typedef _Atomic(_Bool)              atomic_bool;
  97 #endif
  98 typedef _Atomic(char)               atomic_char;
  99 typedef _Atomic(signed char)        atomic_schar;
 100 typedef _Atomic(unsigned char)      atomic_uchar;
 101 typedef _Atomic(short)              atomic_short;
 102 typedef _Atomic(unsigned short)     atomic_ushort;
 103 typedef _Atomic(int)                atomic_int;
 104 typedef _Atomic(unsigned int)       atomic_uint;
 105 typedef _Atomic(long)               atomic_long;
 106 typedef _Atomic(unsigned long)      atomic_ulong;
 107 typedef _Atomic(long long)          atomic_llong;
 108 typedef _Atomic(unsigned long long) atomic_ullong;
 109 typedef _Atomic(uint_least16_t)     atomic_char16_t;
 110 typedef _Atomic(uint_least32_t)     atomic_char32_t;
 111 typedef _Atomic(wchar_t)            atomic_wchar_t;
 112 typedef _Atomic(int_least8_t)       atomic_int_least8_t;
 113 typedef _Atomic(uint_least8_t)      atomic_uint_least8_t;
 114 typedef _Atomic(int_least16_t)      atomic_int_least16_t;
 115 typedef _Atomic(uint_least16_t)     atomic_uint_least16_t;
 116 typedef _Atomic(int_least32_t)      atomic_int_least32_t;
 117 typedef _Atomic(uint_least32_t)     atomic_uint_least32_t;
 118 typedef _Atomic(int_least64_t)      atomic_int_least64_t;
 119 typedef _Atomic(uint_least64_t)     atomic_uint_least64_t;
 120 typedef _Atomic(int_fast8_t)        atomic_int_fast8_t;
 121 typedef _Atomic(uint_fast8_t)       atomic_uint_fast8_t;
 122 typedef _Atomic(int_fast16_t)       atomic_int_fast16_t;
 123 typedef _Atomic(uint_fast16_t)      atomic_uint_fast16_t;
 124 typedef _Atomic(int_fast32_t)       atomic_int_fast32_t;
 125 typedef _Atomic(uint_fast32_t)      atomic_uint_fast32_t;
 126 typedef _Atomic(int_fast64_t)       atomic_int_fast64_t;
 127 typedef _Atomic(uint_fast64_t)      atomic_uint_fast64_t;
 128 typedef _Atomic(intptr_t)           atomic_intptr_t;
 129 typedef _Atomic(uintptr_t)          atomic_uintptr_t;
 130 typedef _Atomic(size_t)             atomic_size_t;
 131 typedef _Atomic(ptrdiff_t)          atomic_ptrdiff_t;
 132 typedef _Atomic(intmax_t)           atomic_intmax_t;
 133 typedef _Atomic(uintmax_t)          atomic_uintmax_t;
 134
 135 /* 7.17.7 Operations on atomic types */
 136
 137 #define atomic_store(object, desired) __c11_atomic_store(object, desired, __ATOMIC_SEQ_CST)
 138 #define atomic_store_explicit __c11_atomic_store
 139
 140 #define atomic_load(object) __c11_atomic_load(object, __ATOMIC_SEQ_CST)
 141 #define atomic_load_explicit __c11_atomic_load
 142
 143 #define atomic_exchange(object, desired) __c11_atomic_exchange(object, desired, __ATOMIC_SEQ_CST)
 144 #define atomic_exchange_explicit __c11_atomic_exchange
 145
 146 #define atomic_compare_exchange_strong(object, expected, desired) __c11_atomic_compare_exchange_strong(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
 147 #define atomic_compare_exchange_strong_explicit __c11_atomic_compare_exchange_strong
 148
 149 #define atomic_compare_exchange_weak(object, expected, desired) __c11_atomic_compare_exchange_weak(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
 150 #define atomic_compare_exchange_weak_explicit __c11_atomic_compare_exchange_weak
 151
 152 #define atomic_fetch_add(object, operand) __c11_atomic_fetch_add(object, operand, __ATOMIC_SEQ_CST)
 153 #define atomic_fetch_add_explicit __c11_atomic_fetch_add
 154
 155 #define atomic_fetch_sub(object, operand) __c11_atomic_fetch_sub(object, operand, __ATOMIC_SEQ_CST)
 156 #define atomic_fetch_sub_explicit __c11_atomic_fetch_sub
 157
 158 #define atomic_fetch_or(object, operand) __c11_atomic_fetch_or(object, operand, __ATOMIC_SEQ_CST)
 159 #define atomic_fetch_or_explicit __c11_atomic_fetch_or
 160
 161 #define atomic_fetch_xor(object, operand) __c11_atomic_fetch_xor(object, operand, __ATOMIC_SEQ_CST)
 162 #define atomic_fetch_xor_explicit __c11_atomic_fetch_xor
 163
 164 #define atomic_fetch_and(object, operand) __c11_atomic_fetch_and(object, operand, __ATOMIC_SEQ_CST)
 165 #define atomic_fetch_and_explicit __c11_atomic_fetch_and
 166
 167 /* 7.17.8 Atomic flag type and operations */
 168
 169 typedef struct atomic_flag { atomic_bool _Value; } atomic_flag;
 170
 171 #define ATOMIC_FLAG_INIT { 0 }
 172
 173 /* These should be provided by the libc implementation. */
 174 #ifdef __cplusplus
 175 bool atomic_flag_test_and_set(volatile atomic_flag *);
 176 bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
 177 #else
 178 _Bool atomic_flag_test_and_set(volatile atomic_flag *);
 179 _Bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
 180 #endif
 181 void atomic_flag_clear(volatile atomic_flag *);
 182 void atomic_flag_clear_explicit(volatile atomic_flag *, memory_order);
 183
 184 #define atomic_flag_test_and_set(object) __c11_atomic_exchange(&(object)->_Value, 1, __ATOMIC_SEQ_CST)
 185 #define atomic_flag_test_and_set_explicit(object, order) __c11_atomic_exchange(&(object)->_Value, 1, order)
 186
 187 #define atomic_flag_clear(object) __c11_atomic_store(&(object)->_Value, 0, __ATOMIC_SEQ_CST)
 188 #define atomic_flag_clear_explicit(object, order) __c11_atomic_store(&(object)->_Value, 0, order)
 189
 190 #ifdef __cplusplus
 191 }
 192 #endif
 193
 194 #endif /* __STDC_HOSTED__ */
 195 #endif /* __CLANG_STDATOMIC_H */
 196