xref: /freebsd/contrib/llvm-project/clang/lib/Headers/stdatomic.h (revision 36b606ae6aa4b24061096ba18582e0a08ccd5dba)
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 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
39 #define ATOMIC_CHAR8_T_LOCK_FREE    __CLANG_ATOMIC_CHAR8_T_LOCK_FREE
40 #endif
41 #define ATOMIC_CHAR16_T_LOCK_FREE   __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
42 #define ATOMIC_CHAR32_T_LOCK_FREE   __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
43 #define ATOMIC_WCHAR_T_LOCK_FREE    __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
44 #define ATOMIC_SHORT_LOCK_FREE      __CLANG_ATOMIC_SHORT_LOCK_FREE
45 #define ATOMIC_INT_LOCK_FREE        __CLANG_ATOMIC_INT_LOCK_FREE
46 #define ATOMIC_LONG_LOCK_FREE       __CLANG_ATOMIC_LONG_LOCK_FREE
47 #define ATOMIC_LLONG_LOCK_FREE      __CLANG_ATOMIC_LLONG_LOCK_FREE
48 #define ATOMIC_POINTER_LOCK_FREE    __CLANG_ATOMIC_POINTER_LOCK_FREE
49 
50 /* 7.17.2 Initialization */
51 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ < 202311L) ||               \
52     defined(__cplusplus)
53 /* ATOMIC_VAR_INIT was removed in C23, but still remains in C++23. */
54 #define ATOMIC_VAR_INIT(value) (value)
55 #endif
56 
57 #if ((defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201710L &&              \
58       __STDC_VERSION__ < 202311L) ||                                           \
59      (defined(__cplusplus) && __cplusplus >= 202002L)) &&                      \
60     !defined(_CLANG_DISABLE_CRT_DEPRECATION_WARNINGS)
61 /* ATOMIC_VAR_INIT was deprecated in C17 and C++20. */
62 #pragma clang deprecated(ATOMIC_VAR_INIT)
63 #endif
64 #define atomic_init __c11_atomic_init
65 
66 /* 7.17.3 Order and consistency */
67 
68 typedef enum memory_order {
69   memory_order_relaxed = __ATOMIC_RELAXED,
70   memory_order_consume = __ATOMIC_CONSUME,
71   memory_order_acquire = __ATOMIC_ACQUIRE,
72   memory_order_release = __ATOMIC_RELEASE,
73   memory_order_acq_rel = __ATOMIC_ACQ_REL,
74   memory_order_seq_cst = __ATOMIC_SEQ_CST
75 } memory_order;
76 
77 #define kill_dependency(y) (y)
78 
79 /* 7.17.4 Fences */
80 
81 /* These should be provided by the libc implementation. */
82 void atomic_thread_fence(memory_order);
83 void atomic_signal_fence(memory_order);
84 
85 #define atomic_thread_fence(order) __c11_atomic_thread_fence(order)
86 #define atomic_signal_fence(order) __c11_atomic_signal_fence(order)
87 
88 /* 7.17.5 Lock-free property */
89 
90 #define atomic_is_lock_free(obj) __c11_atomic_is_lock_free(sizeof(*(obj)))
91 
92 /* 7.17.6 Atomic integer types */
93 
94 #ifdef __cplusplus
95 typedef _Atomic(bool)               atomic_bool;
96 #else
97 typedef _Atomic(_Bool)              atomic_bool;
98 #endif
99 typedef _Atomic(char)               atomic_char;
100 typedef _Atomic(signed char)        atomic_schar;
101 typedef _Atomic(unsigned char)      atomic_uchar;
102 typedef _Atomic(short)              atomic_short;
103 typedef _Atomic(unsigned short)     atomic_ushort;
104 typedef _Atomic(int)                atomic_int;
105 typedef _Atomic(unsigned int)       atomic_uint;
106 typedef _Atomic(long)               atomic_long;
107 typedef _Atomic(unsigned long)      atomic_ulong;
108 typedef _Atomic(long long)          atomic_llong;
109 typedef _Atomic(unsigned long long) atomic_ullong;
110 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
111 typedef _Atomic(unsigned char)      atomic_char8_t;
112 #endif
113 typedef _Atomic(uint_least16_t)     atomic_char16_t;
114 typedef _Atomic(uint_least32_t)     atomic_char32_t;
115 typedef _Atomic(wchar_t)            atomic_wchar_t;
116 typedef _Atomic(int_least8_t)       atomic_int_least8_t;
117 typedef _Atomic(uint_least8_t)      atomic_uint_least8_t;
118 typedef _Atomic(int_least16_t)      atomic_int_least16_t;
119 typedef _Atomic(uint_least16_t)     atomic_uint_least16_t;
120 typedef _Atomic(int_least32_t)      atomic_int_least32_t;
121 typedef _Atomic(uint_least32_t)     atomic_uint_least32_t;
122 typedef _Atomic(int_least64_t)      atomic_int_least64_t;
123 typedef _Atomic(uint_least64_t)     atomic_uint_least64_t;
124 typedef _Atomic(int_fast8_t)        atomic_int_fast8_t;
125 typedef _Atomic(uint_fast8_t)       atomic_uint_fast8_t;
126 typedef _Atomic(int_fast16_t)       atomic_int_fast16_t;
127 typedef _Atomic(uint_fast16_t)      atomic_uint_fast16_t;
128 typedef _Atomic(int_fast32_t)       atomic_int_fast32_t;
129 typedef _Atomic(uint_fast32_t)      atomic_uint_fast32_t;
130 typedef _Atomic(int_fast64_t)       atomic_int_fast64_t;
131 typedef _Atomic(uint_fast64_t)      atomic_uint_fast64_t;
132 typedef _Atomic(intptr_t)           atomic_intptr_t;
133 typedef _Atomic(uintptr_t)          atomic_uintptr_t;
134 typedef _Atomic(size_t)             atomic_size_t;
135 typedef _Atomic(ptrdiff_t)          atomic_ptrdiff_t;
136 typedef _Atomic(intmax_t)           atomic_intmax_t;
137 typedef _Atomic(uintmax_t)          atomic_uintmax_t;
138 
139 /* 7.17.7 Operations on atomic types */
140 
141 #define atomic_store(object, desired) __c11_atomic_store(object, desired, __ATOMIC_SEQ_CST)
142 #define atomic_store_explicit __c11_atomic_store
143 
144 #define atomic_load(object) __c11_atomic_load(object, __ATOMIC_SEQ_CST)
145 #define atomic_load_explicit __c11_atomic_load
146 
147 #define atomic_exchange(object, desired) __c11_atomic_exchange(object, desired, __ATOMIC_SEQ_CST)
148 #define atomic_exchange_explicit __c11_atomic_exchange
149 
150 #define atomic_compare_exchange_strong(object, expected, desired) __c11_atomic_compare_exchange_strong(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
151 #define atomic_compare_exchange_strong_explicit __c11_atomic_compare_exchange_strong
152 
153 #define atomic_compare_exchange_weak(object, expected, desired) __c11_atomic_compare_exchange_weak(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
154 #define atomic_compare_exchange_weak_explicit __c11_atomic_compare_exchange_weak
155 
156 #define atomic_fetch_add(object, operand) __c11_atomic_fetch_add(object, operand, __ATOMIC_SEQ_CST)
157 #define atomic_fetch_add_explicit __c11_atomic_fetch_add
158 
159 #define atomic_fetch_sub(object, operand) __c11_atomic_fetch_sub(object, operand, __ATOMIC_SEQ_CST)
160 #define atomic_fetch_sub_explicit __c11_atomic_fetch_sub
161 
162 #define atomic_fetch_or(object, operand) __c11_atomic_fetch_or(object, operand, __ATOMIC_SEQ_CST)
163 #define atomic_fetch_or_explicit __c11_atomic_fetch_or
164 
165 #define atomic_fetch_xor(object, operand) __c11_atomic_fetch_xor(object, operand, __ATOMIC_SEQ_CST)
166 #define atomic_fetch_xor_explicit __c11_atomic_fetch_xor
167 
168 #define atomic_fetch_and(object, operand) __c11_atomic_fetch_and(object, operand, __ATOMIC_SEQ_CST)
169 #define atomic_fetch_and_explicit __c11_atomic_fetch_and
170 
171 /* 7.17.8 Atomic flag type and operations */
172 
173 typedef struct atomic_flag { atomic_bool _Value; } atomic_flag;
174 
175 #ifdef __cplusplus
176 #define ATOMIC_FLAG_INIT {false}
177 #else
178 #define ATOMIC_FLAG_INIT { 0 }
179 #endif
180 
181 /* These should be provided by the libc implementation. */
182 #ifdef __cplusplus
183 bool atomic_flag_test_and_set(volatile atomic_flag *);
184 bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
185 #else
186 _Bool atomic_flag_test_and_set(volatile atomic_flag *);
187 _Bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
188 #endif
189 void atomic_flag_clear(volatile atomic_flag *);
190 void atomic_flag_clear_explicit(volatile atomic_flag *, memory_order);
191 
192 #define atomic_flag_test_and_set(object) __c11_atomic_exchange(&(object)->_Value, 1, __ATOMIC_SEQ_CST)
193 #define atomic_flag_test_and_set_explicit(object, order) __c11_atomic_exchange(&(object)->_Value, 1, order)
194 
195 #define atomic_flag_clear(object) __c11_atomic_store(&(object)->_Value, 0, __ATOMIC_SEQ_CST)
196 #define atomic_flag_clear_explicit(object, order) __c11_atomic_store(&(object)->_Value, 0, order)
197 
198 #ifdef __cplusplus
199 }
200 #endif
201 
202 #endif /* __STDC_HOSTED__ */
203 #endif /* __CLANG_STDATOMIC_H */
204 
205