chiark / gitweb /
tree-wide: drop 'This file is part of systemd' blurb
[elogind.git] / src / basic / macro.h
1 /* SPDX-License-Identifier: LGPL-2.1+ */
2 #pragma once
3
4 /***
5   Copyright 2010 Lennart Poettering
6 ***/
7
8 #include <inttypes.h>
9 #include <stdbool.h>
10 #include <sys/param.h>
11 #include <sys/sysmacros.h>
12 #include <sys/types.h>
13
14 #define _printf_(a,b) __attribute__ ((format (printf, a, b)))
15 #ifdef __clang__
16 #  define _alloc_(...)
17 #else
18 #  define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
19 #endif
20 #define _sentinel_ __attribute__ ((sentinel))
21 #define _unused_ __attribute__ ((unused))
22 #define _destructor_ __attribute__ ((destructor))
23 #define _pure_ __attribute__ ((pure))
24 #define _const_ __attribute__ ((const))
25 #define _deprecated_ __attribute__ ((deprecated))
26 #define _packed_ __attribute__ ((packed))
27 #define _malloc_ __attribute__ ((malloc))
28 #define _weak_ __attribute__ ((weak))
29 #define _likely_(x) (__builtin_expect(!!(x),1))
30 #define _unlikely_(x) (__builtin_expect(!!(x),0))
31 #define _public_ __attribute__ ((visibility("default")))
32 #define _hidden_ __attribute__ ((visibility("hidden")))
33 #define _weakref_(x) __attribute__((weakref(#x)))
34 #define _alignas_(x) __attribute__((aligned(__alignof(x))))
35 #define _cleanup_(x) __attribute__((cleanup(x)))
36 #if __GNUC__ >= 7
37 #define _fallthrough_ __attribute__((fallthrough))
38 #else
39 #define _fallthrough_
40 #endif
41 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
42  * compiler versions */
43 #ifndef _noreturn_
44 #if __STDC_VERSION__ >= 201112L
45 #define _noreturn_ _Noreturn
46 #else
47 #define _noreturn_ __attribute__((noreturn))
48 #endif
49 #endif
50
51 #if !defined(HAS_FEATURE_MEMORY_SANITIZER)
52 #  if defined(__has_feature)
53 #    if __has_feature(memory_sanitizer)
54 #      define HAS_FEATURE_MEMORY_SANITIZER 1
55 #    endif
56 #  endif
57 #  if !defined(HAS_FEATURE_MEMORY_SANITIZER)
58 #    define HAS_FEATURE_MEMORY_SANITIZER 0
59 #  endif
60 #endif
61
62 /* Temporarily disable some warnings */
63 #define DISABLE_WARNING_DECLARATION_AFTER_STATEMENT                     \
64         _Pragma("GCC diagnostic push");                                 \
65         _Pragma("GCC diagnostic ignored \"-Wdeclaration-after-statement\"")
66
67 #define DISABLE_WARNING_FORMAT_NONLITERAL                               \
68         _Pragma("GCC diagnostic push");                                 \
69         _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
70
71 #define DISABLE_WARNING_MISSING_PROTOTYPES                              \
72         _Pragma("GCC diagnostic push");                                 \
73         _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
74
75 #define DISABLE_WARNING_NONNULL                                         \
76         _Pragma("GCC diagnostic push");                                 \
77         _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
78
79 #define DISABLE_WARNING_SHADOW                                          \
80         _Pragma("GCC diagnostic push");                                 \
81         _Pragma("GCC diagnostic ignored \"-Wshadow\"")
82
83 #define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
84         _Pragma("GCC diagnostic push");                                 \
85         _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
86
87 #define REENABLE_WARNING                                                \
88         _Pragma("GCC diagnostic pop")
89
90 /* automake test harness */
91 #define EXIT_TEST_SKIP 77
92
93 #define XSTRINGIFY(x) #x
94 #define STRINGIFY(x) XSTRINGIFY(x)
95
96 #define XCONCATENATE(x, y) x ## y
97 #define CONCATENATE(x, y) XCONCATENATE(x, y)
98
99 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
100 #define UNIQ __COUNTER__
101
102 /* builtins */
103 #if __SIZEOF_INT__ == 4
104 #define BUILTIN_FFS_U32(x) __builtin_ffs(x);
105 #elif __SIZEOF_LONG__ == 4
106 #define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
107 #else
108 #error "neither int nor long are four bytes long?!?"
109 #endif
110
111 /* Rounds up */
112
113 #define ALIGN4(l) (((l) + 3) & ~3)
114 #define ALIGN8(l) (((l) + 7) & ~7)
115
116 #if __SIZEOF_POINTER__ == 8
117 #define ALIGN(l) ALIGN8(l)
118 #elif __SIZEOF_POINTER__ == 4
119 #define ALIGN(l) ALIGN4(l)
120 #else
121 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
122 #endif
123
124 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
125 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
126 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
127
128 static inline size_t ALIGN_TO(size_t l, size_t ali) {
129         return ((l + ali - 1) & ~(ali - 1));
130 }
131
132 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
133
134 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
135 static inline unsigned long ALIGN_POWER2(unsigned long u) {
136         /* clz(0) is undefined */
137         if (u == 1)
138                 return 1;
139
140         /* left-shift overflow is undefined */
141         if (__builtin_clzl(u - 1UL) < 1)
142                 return 0;
143
144         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
145 }
146
147 #ifndef __COVERITY__
148 #  define VOID_0 ((void)0)
149 #else
150 #  define VOID_0 ((void*)0)
151 #endif
152
153 #define ELEMENTSOF(x)                                                    \
154         __extension__ (__builtin_choose_expr(                            \
155                 !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
156                 sizeof(x)/sizeof((x)[0]),                                \
157                 VOID_0))
158
159 /*
160  * STRLEN - return the length of a string literal, minus the trailing NUL byte.
161  *          Contrary to strlen(), this is a constant expression.
162  * @x: a string literal.
163  */
164 #define STRLEN(x) (sizeof(""x"") - 1)
165
166 /*
167  * container_of - cast a member of a structure out to the containing structure
168  * @ptr: the pointer to the member.
169  * @type: the type of the container struct this is embedded in.
170  * @member: the name of the member within the struct.
171  */
172 #define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
173 #define __container_of(uniq, ptr, type, member)                         \
174         __extension__ ({                                                \
175                 const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
176                 (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type,member) ); \
177         })
178
179 #undef MAX
180 #define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
181 #define __MAX(aq, a, bq, b)                             \
182         __extension__ ({                                \
183                 const typeof(a) UNIQ_T(A, aq) = (a);    \
184                 const typeof(b) UNIQ_T(B, bq) = (b);    \
185                 UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
186         })
187
188 /* evaluates to (void) if _A or _B are not constant or of different types */
189 #define CONST_MAX(_A, _B) \
190         __extension__ (__builtin_choose_expr(                           \
191                 __builtin_constant_p(_A) &&                             \
192                 __builtin_constant_p(_B) &&                             \
193                 __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
194                 ((_A) > (_B)) ? (_A) : (_B),                            \
195                 VOID_0))
196
197 /* takes two types and returns the size of the larger one */
198 #define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
199
200 #define MAX3(x,y,z)                                     \
201         __extension__ ({                                \
202                         const typeof(x) _c = MAX(x,y);  \
203                         MAX(_c, z);                     \
204                 })
205
206 #undef MIN
207 #define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
208 #define __MIN(aq, a, bq, b)                             \
209         __extension__ ({                                \
210                 const typeof(a) UNIQ_T(A, aq) = (a);    \
211                 const typeof(b) UNIQ_T(B, bq) = (b);    \
212                 UNIQ_T(A,aq) < UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
213         })
214
215 #define MIN3(x,y,z)                                     \
216         __extension__ ({                                \
217                         const typeof(x) _c = MIN(x,y);  \
218                         MIN(_c, z);                     \
219                 })
220
221 #define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
222 #define __LESS_BY(aq, a, bq, b)                         \
223         __extension__ ({                                \
224                 const typeof(a) UNIQ_T(A, aq) = (a);    \
225                 const typeof(b) UNIQ_T(B, bq) = (b);    \
226                 UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) - UNIQ_T(B,bq) : 0; \
227         })
228
229 #undef CLAMP
230 #define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
231 #define __CLAMP(xq, x, lowq, low, highq, high)                          \
232         __extension__ ({                                                \
233                 const typeof(x) UNIQ_T(X,xq) = (x);                     \
234                 const typeof(low) UNIQ_T(LOW,lowq) = (low);             \
235                 const typeof(high) UNIQ_T(HIGH,highq) = (high);         \
236                         UNIQ_T(X,xq) > UNIQ_T(HIGH,highq) ?             \
237                                 UNIQ_T(HIGH,highq) :                    \
238                                 UNIQ_T(X,xq) < UNIQ_T(LOW,lowq) ?       \
239                                         UNIQ_T(LOW,lowq) :              \
240                                         UNIQ_T(X,xq);                   \
241         })
242
243 /* [(x + y - 1) / y] suffers from an integer overflow, even though the
244  * computation should be possible in the given type. Therefore, we use
245  * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
246  * quotient and the remainder, so both should be equally fast. */
247 #define DIV_ROUND_UP(_x, _y)                                            \
248         __extension__ ({                                                \
249                 const typeof(_x) __x = (_x);                            \
250                 const typeof(_y) __y = (_y);                            \
251                 (__x / __y + !!(__x % __y));                            \
252         })
253
254 #define assert_message_se(expr, message)                                \
255         do {                                                            \
256                 if (_unlikely_(!(expr)))                                \
257                         log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
258         } while (false)
259
260 #define assert_se(expr) assert_message_se(expr, #expr)
261
262 /* We override the glibc assert() here. */
263 #undef assert
264 #ifdef NDEBUG
265 #define assert(expr) do {} while (false)
266 #else
267 #define assert(expr) assert_message_se(expr, #expr)
268 #endif
269
270 #define assert_not_reached(t)                                           \
271         do {                                                            \
272                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
273         } while (false)
274
275 #if defined(static_assert)
276 /* static_assert() is sometimes defined in a way that trips up
277  * -Wdeclaration-after-statement, hence let's temporarily turn off
278  * this warning around it. */
279 #define assert_cc(expr)                                                 \
280         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
281         static_assert(expr, #expr);                                     \
282         REENABLE_WARNING
283 #else
284 #define assert_cc(expr)                                                 \
285         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
286         struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
287                 char x[(expr) ? 0 : -1];                                \
288         };                                                              \
289         REENABLE_WARNING
290 #endif
291
292 #define assert_log(expr, message) ((_likely_(expr))                     \
293         ? (true)                                                        \
294         : (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
295
296 #define assert_return(expr, r)                                          \
297         do {                                                            \
298                 if (!assert_log(expr, #expr))                           \
299                         return (r);                                     \
300         } while (false)
301
302 #define assert_return_errno(expr, r, err)                               \
303         do {                                                            \
304                 if (!assert_log(expr, #expr)) {                         \
305                         errno = err;                                    \
306                         return (r);                                     \
307                 }                                                       \
308         } while (false)
309
310 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
311 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
312 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
313 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
314
315 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
316 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
317 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
318 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
319
320 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
321 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
322 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
323 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
324
325 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
326 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
327 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
328 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
329
330 #define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
331 #define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
332
333 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
334
335 #define char_array_0(x) x[sizeof(x)-1] = 0;
336
337 /* Returns the number of chars needed to format variables of the
338  * specified type as a decimal string. Adds in extra space for a
339  * negative '-' prefix (hence works correctly on signed
340  * types). Includes space for the trailing NUL. */
341 #define DECIMAL_STR_MAX(type)                                           \
342         (2+(sizeof(type) <= 1 ? 3 :                                     \
343             sizeof(type) <= 2 ? 5 :                                     \
344             sizeof(type) <= 4 ? 10 :                                    \
345             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
346
347 #define DECIMAL_STR_WIDTH(x)                            \
348         ({                                              \
349                 typeof(x) _x_ = (x);                    \
350                 unsigned ans = 1;                       \
351                 while ((_x_ /= 10) != 0)                \
352                         ans++;                          \
353                 ans;                                    \
354         })
355
356 #define SET_FLAG(v, flag, b) \
357         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
358 #define FLAGS_SET(v, flags) \
359         (((v) & (flags)) == (flags))
360
361 #define CASE_F(X) case X:
362 #define CASE_F_1(CASE, X) CASE_F(X)
363 #define CASE_F_2(CASE, X, ...)  CASE(X) CASE_F_1(CASE, __VA_ARGS__)
364 #define CASE_F_3(CASE, X, ...)  CASE(X) CASE_F_2(CASE, __VA_ARGS__)
365 #define CASE_F_4(CASE, X, ...)  CASE(X) CASE_F_3(CASE, __VA_ARGS__)
366 #define CASE_F_5(CASE, X, ...)  CASE(X) CASE_F_4(CASE, __VA_ARGS__)
367 #define CASE_F_6(CASE, X, ...)  CASE(X) CASE_F_5(CASE, __VA_ARGS__)
368 #define CASE_F_7(CASE, X, ...)  CASE(X) CASE_F_6(CASE, __VA_ARGS__)
369 #define CASE_F_8(CASE, X, ...)  CASE(X) CASE_F_7(CASE, __VA_ARGS__)
370 #define CASE_F_9(CASE, X, ...)  CASE(X) CASE_F_8(CASE, __VA_ARGS__)
371 #define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
372 #define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
373 #define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
374 #define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
375 #define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
376 #define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
377 #define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
378 #define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
379 #define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
380 #define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
381 #define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
382
383 #define GET_CASE_F(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,NAME,...) NAME
384 #define FOR_EACH_MAKE_CASE(...) \
385         GET_CASE_F(__VA_ARGS__,CASE_F_20,CASE_F_19,CASE_F_18,CASE_F_17,CASE_F_16,CASE_F_15,CASE_F_14,CASE_F_13,CASE_F_12,CASE_F_11, \
386                                CASE_F_10,CASE_F_9,CASE_F_8,CASE_F_7,CASE_F_6,CASE_F_5,CASE_F_4,CASE_F_3,CASE_F_2,CASE_F_1) \
387                    (CASE_F,__VA_ARGS__)
388
389 #define IN_SET(x, ...)                          \
390         ({                                      \
391                 bool _found = false;            \
392                 /* If the build breaks in the line below, you need to extend the case macros */ \
393                 static _unused_ char _static_assert__macros_need_to_be_extended[20 - sizeof((int[]){__VA_ARGS__})/sizeof(int)]; \
394                 switch(x) {                     \
395                 FOR_EACH_MAKE_CASE(__VA_ARGS__) \
396                         _found = true;          \
397                         break;                  \
398                 default:                        \
399                         break;                  \
400                 }                               \
401                 _found;                         \
402         })
403
404 #define SWAP_TWO(x, y) do {                        \
405                 typeof(x) _t = (x);                \
406                 (x) = (y);                         \
407                 (y) = (_t);                        \
408         } while (false)
409
410 /* Define C11 thread_local attribute even on older gcc compiler
411  * version */
412 #ifndef thread_local
413 /*
414  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
415  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
416  */
417 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
418 #define thread_local _Thread_local
419 #else
420 #define thread_local __thread
421 #endif
422 #endif
423
424 #define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
425         static inline void func##p(type *p) {                   \
426                 if (*p)                                         \
427                         func(*p);                               \
428         }
429
430 #include "log.h"