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d3d3857f MJ |
1 | // SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
2 | // | |
3 | // SPDX-License-Identifier: LGPL-2.1-or-later | |
4 | ||
ec4e58a3 MD |
5 | #ifndef _URCU_COMPILER_H |
6 | #define _URCU_COMPILER_H | |
af02d47e MD |
7 | |
8 | /* | |
af02d47e | 9 | * Compiler definitions. |
af02d47e MD |
10 | */ |
11 | ||
49d7d158 MD |
12 | #include <stddef.h> /* for offsetof */ |
13 | ||
06326a94 SM |
14 | #if defined __cplusplus |
15 | # include <type_traits> /* for std::remove_cv */ | |
16 | #endif | |
17 | ||
865024e9 OD |
18 | #include <urcu/config.h> |
19 | ||
a0b7f7ea MD |
20 | #define caa_likely(x) __builtin_expect(!!(x), 1) |
21 | #define caa_unlikely(x) __builtin_expect(!!(x), 0) | |
2dc5fa0f | 22 | |
865024e9 OD |
23 | #ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS |
24 | # define cmm_barrier() __atomic_signal_fence(__ATOMIC_SEQ_CST) | |
25 | #else | |
26 | # define cmm_barrier() __asm__ __volatile__ ("" : : : "memory") | |
27 | #endif | |
2dc5fa0f | 28 | |
af02d47e MD |
29 | /* |
30 | * Instruct the compiler to perform only a single access to a variable | |
31 | * (prohibits merging and refetching). The compiler is also forbidden to reorder | |
6cf3827c | 32 | * successive instances of CMM_ACCESS_ONCE(), but only when the compiler is aware of |
af02d47e | 33 | * particular ordering. Compiler ordering can be ensured, for example, by |
6cf3827c | 34 | * putting two CMM_ACCESS_ONCE() in separate C statements. |
af02d47e MD |
35 | * |
36 | * This macro does absolutely -nothing- to prevent the CPU from reordering, | |
37 | * merging, or refetching absolutely anything at any time. Its main intended | |
38 | * use is to mediate communication between process-level code and irq/NMI | |
39 | * handlers, all running on the same CPU. | |
40 | */ | |
e51500ed | 41 | #define CMM_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x)) |
af02d47e | 42 | |
2f8a5ae7 MD |
43 | #ifndef caa_max |
44 | #define caa_max(a,b) ((a)>(b)?(a):(b)) | |
fdee2e6d MD |
45 | #endif |
46 | ||
2f8a5ae7 MD |
47 | #ifndef caa_min |
48 | #define caa_min(a,b) ((a)<(b)?(a):(b)) | |
fdee2e6d MD |
49 | #endif |
50 | ||
1b27a772 | 51 | #if defined(__SIZEOF_LONG__) |
06f22bdb | 52 | #define CAA_BITS_PER_LONG (__SIZEOF_LONG__ * 8) |
1b27a772 | 53 | #elif defined(_LP64) |
06f22bdb | 54 | #define CAA_BITS_PER_LONG 64 |
1b27a772 | 55 | #else |
06f22bdb | 56 | #define CAA_BITS_PER_LONG 32 |
1b27a772 PB |
57 | #endif |
58 | ||
b194c06e MD |
59 | /* |
60 | * caa_container_of - Get the address of an object containing a field. | |
61 | * | |
62 | * @ptr: pointer to the field. | |
63 | * @type: type of the object. | |
64 | * @member: name of the field within the object. | |
65 | */ | |
66 | #define caa_container_of(ptr, type, member) \ | |
1b85da85 | 67 | __extension__ \ |
453629a9 | 68 | ({ \ |
bdffa73a | 69 | const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \ |
453629a9 MD |
70 | (type *)((char *)__ptr - offsetof(type, member)); \ |
71 | }) | |
72 | ||
4b3a7ebd MD |
73 | /* |
74 | * caa_container_of_check_null - Get the address of an object containing a field. | |
75 | * | |
76 | * @ptr: pointer to the field. | |
77 | * @type: type of the object. | |
78 | * @member: name of the field within the object. | |
79 | * | |
80 | * Return the address of the object containing the field. Return NULL if | |
81 | * @ptr is NULL. | |
82 | */ | |
83 | #define caa_container_of_check_null(ptr, type, member) \ | |
84 | __extension__ \ | |
85 | ({ \ | |
86 | const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \ | |
87 | (__ptr) ? (type *)((char *)__ptr - offsetof(type, member)) : NULL; \ | |
88 | }) | |
89 | ||
78bec10c | 90 | #define CAA_BUILD_BUG_ON_ZERO(cond) (sizeof(struct { int:-!!(cond); })) |
9f59b220 | 91 | #define CAA_BUILD_BUG_ON(cond) ((void)CAA_BUILD_BUG_ON_ZERO(cond)) |
78bec10c | 92 | |
dc53e23e MD |
93 | /* |
94 | * __rcu is an annotation that documents RCU pointer accesses that need | |
95 | * to be protected by a read-side critical section. Eventually, a static | |
96 | * checker will be able to use this annotation to detect incorrect RCU | |
97 | * usage. | |
98 | */ | |
99 | #define __rcu | |
100 | ||
4501f284 | 101 | #ifdef __cplusplus |
06326a94 | 102 | #define URCU_FORCE_CAST(_type, arg) (reinterpret_cast<std::remove_cv<_type>::type>(arg)) |
4501f284 MD |
103 | #else |
104 | #define URCU_FORCE_CAST(type, arg) ((type) (arg)) | |
105 | #endif | |
106 | ||
4b5f005b | 107 | #define caa_is_signed_type(type) ((type) -1 < (type) 0) |
e56d99bf | 108 | |
4b5f005b | 109 | /* |
e4749953 MD |
110 | * Cast to unsigned long, sign-extending if @v is signed. |
111 | * Note: casting to a larger type or to same type size keeps the sign of | |
112 | * the expression being cast (see C99 6.3.1.3). | |
4b5f005b | 113 | */ |
e4749953 | 114 | #define caa_cast_long_keep_sign(v) ((unsigned long) (v)) |
e56d99bf | 115 | |
706d1165 | 116 | #if defined (__GNUC__) \ |
a0a0c4d5 EC |
117 | && ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5) \ |
118 | || __GNUC__ >= 5) | |
706d1165 MD |
119 | #define CDS_DEPRECATED(msg) \ |
120 | __attribute__((deprecated(msg))) | |
121 | #else | |
122 | #define CDS_DEPRECATED(msg) \ | |
123 | __attribute__((deprecated)) | |
124 | #endif | |
125 | ||
e323ceac MD |
126 | #define CAA_ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) |
127 | ||
1b4fed78 MJ |
128 | /* |
129 | * URCU_GCC_VERSION is used to blacklist specific GCC versions with known | |
130 | * bugs, clang also defines these macros to an equivalent GCC version it | |
131 | * claims to support, so exclude it. | |
132 | */ | |
133 | #if defined(__GNUC__) && !defined(__clang__) | |
4b79310a MD |
134 | # define URCU_GCC_VERSION (__GNUC__ * 10000 \ |
135 | + __GNUC_MINOR__ * 100 \ | |
136 | + __GNUC_PATCHLEVEL__) | |
4b79310a MD |
137 | #endif |
138 | ||
d1854484 OD |
139 | #ifdef __cplusplus |
140 | #define caa_unqual_scalar_typeof(x) \ | |
141 | std::remove_cv<std::remove_reference<decltype(x)>::type>::type | |
142 | #else | |
143 | #define caa_scalar_type_to_expr(type) \ | |
144 | unsigned type: (unsigned type)0, \ | |
145 | signed type: (signed type)0 | |
146 | ||
147 | /* | |
148 | * Use C11 _Generic to express unqualified type from expression. This removes | |
149 | * volatile qualifier from expression type. | |
150 | */ | |
151 | #define caa_unqual_scalar_typeof(x) \ | |
152 | __typeof__( \ | |
153 | _Generic((x), \ | |
154 | char: (char)0, \ | |
155 | caa_scalar_type_to_expr(char), \ | |
156 | caa_scalar_type_to_expr(short), \ | |
157 | caa_scalar_type_to_expr(int), \ | |
158 | caa_scalar_type_to_expr(long), \ | |
159 | caa_scalar_type_to_expr(long long), \ | |
160 | default: (x) \ | |
161 | ) \ | |
162 | ) | |
163 | #endif | |
164 | ||
165 | /* | |
166 | * Allow user to manually define CMM_SANITIZE_THREAD if their toolchain is not | |
167 | * supported by this check. | |
168 | */ | |
169 | #ifndef CMM_SANITIZE_THREAD | |
170 | # if defined(__GNUC__) && defined(__SANITIZE_THREAD__) | |
171 | # define CMM_SANITIZE_THREAD | |
172 | # elif defined(__clang__) && defined(__has_feature) | |
173 | # if __has_feature(thread_sanitizer) | |
174 | # define CMM_SANITIZE_THREAD | |
175 | # endif | |
176 | # endif | |
177 | #endif /* !CMM_SANITIZE_THREAD */ | |
178 | ||
179 | /* | |
180 | * Helper to add the volatile qualifier to a pointer. | |
181 | */ | |
182 | #if defined __cplusplus | |
183 | template <typename T> | |
184 | volatile T cmm_cast_volatile(T t) | |
185 | { | |
186 | return static_cast<volatile T>(t); | |
187 | } | |
188 | #else | |
189 | # define cmm_cast_volatile(ptr) \ | |
190 | __extension__ \ | |
191 | ({ \ | |
192 | (volatile __typeof__(ptr))(ptr); \ | |
193 | }) | |
194 | #endif | |
195 | ||
455a8429 OD |
196 | /* |
197 | * Compile time assertion. | |
198 | * - predicate: boolean expression to evaluate, | |
199 | * - msg: string to print to the user on failure when `static_assert()` is | |
200 | * supported, | |
201 | * - c_identifier_msg: message to be included in the typedef to emulate a | |
202 | * static assertion. This parameter must be a valid C identifier as it will | |
203 | * be used as a typedef name. | |
204 | */ | |
205 | #ifdef __cplusplus | |
206 | #define urcu_static_assert(predicate, msg, c_identifier_msg) \ | |
207 | static_assert(predicate, msg) | |
208 | #elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) | |
209 | #define urcu_static_assert(predicate, msg, c_identifier_msg) \ | |
210 | _Static_assert(predicate, msg) | |
211 | #else | |
212 | /* | |
213 | * Evaluates the predicate and emit a compilation error on failure. | |
214 | * | |
215 | * If the predicate evaluates to true, this macro emits a function | |
216 | * prototype with an argument type which is an array of size 0. | |
217 | * | |
218 | * If the predicate evaluates to false, this macro emits a function | |
219 | * prototype with an argument type which is an array of negative size | |
220 | * which is invalid in C and forces a compiler error. The | |
221 | * c_identifier_msg parameter is used as the argument identifier so it | |
222 | * is printed to the user when the error is reported. | |
223 | */ | |
224 | #define urcu_static_assert(predicate, msg, c_identifier_msg) \ | |
225 | void urcu_static_assert_proto(char c_identifier_msg[2*!!(predicate)-1]) | |
226 | #endif | |
227 | ||
ec4e58a3 | 228 | #endif /* _URCU_COMPILER_H */ |