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macros: add CMP(a, b) macro.
[thirdparty/systemd.git] / src / basic / macro.h
CommitLineData
53e1b683 1/* SPDX-License-Identifier: LGPL-2.1+ */
c2f1db8f 2#pragma once
60918275 3
c31e1495 4#include <inttypes.h>
c01ff965 5#include <stdbool.h>
afc5dbf3 6#include <sys/param.h>
27d13af7 7#include <sys/sysmacros.h>
afc5dbf3 8#include <sys/types.h>
60918275 9
117efe06 10#define _printf_(a, b) __attribute__ ((format (printf, a, b)))
26e9e10b
ZJS
11#ifdef __clang__
12# define _alloc_(...)
13#else
14# define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
15#endif
93a46b0b 16#define _sentinel_ __attribute__ ((sentinel))
93a46b0b
LP
17#define _unused_ __attribute__ ((unused))
18#define _destructor_ __attribute__ ((destructor))
19#define _pure_ __attribute__ ((pure))
20#define _const_ __attribute__ ((const))
21#define _deprecated_ __attribute__ ((deprecated))
22#define _packed_ __attribute__ ((packed))
23#define _malloc_ __attribute__ ((malloc))
24#define _weak_ __attribute__ ((weak))
117efe06
FB
25#define _likely_(x) (__builtin_expect(!!(x), 1))
26#define _unlikely_(x) (__builtin_expect(!!(x), 0))
40473a70
LP
27#define _public_ __attribute__ ((visibility("default")))
28#define _hidden_ __attribute__ ((visibility("hidden")))
ad780f19 29#define _weakref_(x) __attribute__((weakref(#x)))
19d1e4ee 30#define _alignas_(x) __attribute__((aligned(__alignof(x))))
dfb33a97 31#define _cleanup_(x) __attribute__((cleanup(x)))
fb8e74a4 32#if __GNUC__ >= 7
4831981d 33#define _fallthrough_ __attribute__((fallthrough))
fb8e74a4
SL
34#else
35#define _fallthrough_
36#endif
848e863a
FB
37/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
38 * compiler versions */
39#ifndef _noreturn_
40#if __STDC_VERSION__ >= 201112L
41#define _noreturn_ _Noreturn
42#else
43#define _noreturn_ __attribute__((noreturn))
44#endif
45#endif
60918275 46
989290db
ZJS
47#if !defined(HAS_FEATURE_MEMORY_SANITIZER)
48# if defined(__has_feature)
49# if __has_feature(memory_sanitizer)
50# define HAS_FEATURE_MEMORY_SANITIZER 1
51# endif
52# endif
53# if !defined(HAS_FEATURE_MEMORY_SANITIZER)
54# define HAS_FEATURE_MEMORY_SANITIZER 0
55# endif
56#endif
57
7ebe131a
LP
58/* Temporarily disable some warnings */
59#define DISABLE_WARNING_DECLARATION_AFTER_STATEMENT \
60 _Pragma("GCC diagnostic push"); \
61 _Pragma("GCC diagnostic ignored \"-Wdeclaration-after-statement\"")
62
bcfce235
LP
63#define DISABLE_WARNING_FORMAT_NONLITERAL \
64 _Pragma("GCC diagnostic push"); \
65 _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
66
f0f2e63b
LP
67#define DISABLE_WARNING_MISSING_PROTOTYPES \
68 _Pragma("GCC diagnostic push"); \
69 _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
70
8fca4e30
LP
71#define DISABLE_WARNING_NONNULL \
72 _Pragma("GCC diagnostic push"); \
73 _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
74
d442e2ec
DH
75#define DISABLE_WARNING_SHADOW \
76 _Pragma("GCC diagnostic push"); \
77 _Pragma("GCC diagnostic ignored \"-Wshadow\"")
78
df99a9ef
ZJS
79#define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES \
80 _Pragma("GCC diagnostic push"); \
81 _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
82
7ebe131a
LP
83#define REENABLE_WARNING \
84 _Pragma("GCC diagnostic pop")
85
49e5de64
ZJS
86/* automake test harness */
87#define EXIT_TEST_SKIP 77
88
bef2733f
LP
89#define XSTRINGIFY(x) #x
90#define STRINGIFY(x) XSTRINGIFY(x)
91
ab9cbe34
LS
92#define XCONCATENATE(x, y) x ## y
93#define CONCATENATE(x, y) XCONCATENATE(x, y)
94
fb835651
DH
95#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
96#define UNIQ __COUNTER__
97
13b498f9
TJ
98/* builtins */
99#if __SIZEOF_INT__ == 4
100#define BUILTIN_FFS_U32(x) __builtin_ffs(x);
101#elif __SIZEOF_LONG__ == 4
102#define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
103#else
104#error "neither int nor long are four bytes long?!?"
105#endif
106
60918275 107/* Rounds up */
9be9c7cf
LP
108
109#define ALIGN4(l) (((l) + 3) & ~3)
110#define ALIGN8(l) (((l) + 7) & ~7)
111
112#if __SIZEOF_POINTER__ == 8
113#define ALIGN(l) ALIGN8(l)
114#elif __SIZEOF_POINTER__ == 4
115#define ALIGN(l) ALIGN4(l)
116#else
117#error "Wut? Pointers are neither 4 nor 8 bytes long?"
118#endif
119
5f86c1f4
LP
120#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
121#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
122#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
e86b80b8 123
37f85e66 124static inline size_t ALIGN_TO(size_t l, size_t ali) {
125 return ((l + ali - 1) & ~(ali - 1));
22be093f
LP
126}
127
5f86c1f4 128#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
49aa47c7 129
625e870b
DH
130/* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
131static inline unsigned long ALIGN_POWER2(unsigned long u) {
132 /* clz(0) is undefined */
133 if (u == 1)
134 return 1;
135
136 /* left-shift overflow is undefined */
137 if (__builtin_clzl(u - 1UL) < 1)
138 return 0;
139
140 return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
141}
142
963c6c90
ZJS
143#ifndef __COVERITY__
144# define VOID_0 ((void)0)
145#else
146# define VOID_0 ((void*)0)
147#endif
148
117efe06
FB
149#define ELEMENTSOF(x) \
150 (__builtin_choose_expr( \
7f39a210 151 !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
117efe06 152 sizeof(x)/sizeof((x)[0]), \
963c6c90 153 VOID_0))
6febe75d
TH
154
155/*
156 * STRLEN - return the length of a string literal, minus the trailing NUL byte.
157 * Contrary to strlen(), this is a constant expression.
158 * @x: a string literal.
159 */
160#define STRLEN(x) (sizeof(""x"") - 1)
161
bbc98d32
KS
162/*
163 * container_of - cast a member of a structure out to the containing structure
164 * @ptr: the pointer to the member.
165 * @type: the type of the container struct this is embedded in.
166 * @member: the name of the member within the struct.
bbc98d32 167 */
fb835651
DH
168#define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
169#define __container_of(uniq, ptr, type, member) \
117efe06 170 ({ \
fb835651 171 const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
117efe06 172 (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type, member) ); \
fb835651 173 })
bbc98d32 174
9607d947 175#undef MAX
667a0377
DH
176#define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
177#define __MAX(aq, a, bq, b) \
117efe06 178 ({ \
667a0377
DH
179 const typeof(a) UNIQ_T(A, aq) = (a); \
180 const typeof(b) UNIQ_T(B, bq) = (b); \
117efe06 181 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
667a0377 182 })
60918275 183
7242d742
DH
184/* evaluates to (void) if _A or _B are not constant or of different types */
185#define CONST_MAX(_A, _B) \
117efe06 186 (__builtin_choose_expr( \
7242d742
DH
187 __builtin_constant_p(_A) && \
188 __builtin_constant_p(_B) && \
189 __builtin_types_compatible_p(typeof(_A), typeof(_B)), \
190 ((_A) > (_B)) ? (_A) : (_B), \
963c6c90 191 VOID_0))
7242d742 192
40a1eebd
DH
193/* takes two types and returns the size of the larger one */
194#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
195
117efe06
FB
196#define MAX3(x, y, z) \
197 ({ \
198 const typeof(x) _c = MAX(x, y); \
199 MAX(_c, z); \
200 })
3b63d2d3 201
9607d947 202#undef MIN
667a0377
DH
203#define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
204#define __MIN(aq, a, bq, b) \
117efe06 205 ({ \
667a0377
DH
206 const typeof(a) UNIQ_T(A, aq) = (a); \
207 const typeof(b) UNIQ_T(B, bq) = (b); \
117efe06 208 UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
667a0377 209 })
60918275 210
117efe06
FB
211#define MIN3(x, y, z) \
212 ({ \
213 const typeof(x) _c = MIN(x, y); \
214 MIN(_c, z); \
215 })
7df23077 216
667a0377
DH
217#define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
218#define __LESS_BY(aq, a, bq, b) \
117efe06 219 ({ \
667a0377
DH
220 const typeof(a) UNIQ_T(A, aq) = (a); \
221 const typeof(b) UNIQ_T(B, bq) = (b); \
117efe06 222 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
667a0377 223 })
348ced90 224
84fb2131
FB
225#define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
226#define __CMP(aq, a, bq, b) \
227 ({ \
228 const typeof(a) UNIQ_T(A, aq) = (a); \
229 const typeof(b) UNIQ_T(B, bq) = (b); \
230 UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 : \
231 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0; \
232 })
233
667a0377
DH
234#undef CLAMP
235#define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
236#define __CLAMP(xq, x, lowq, low, highq, high) \
117efe06
FB
237 ({ \
238 const typeof(x) UNIQ_T(X, xq) = (x); \
239 const typeof(low) UNIQ_T(LOW, lowq) = (low); \
240 const typeof(high) UNIQ_T(HIGH, highq) = (high); \
241 UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ? \
242 UNIQ_T(HIGH, highq) : \
243 UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ? \
244 UNIQ_T(LOW, lowq) : \
245 UNIQ_T(X, xq); \
667a0377 246 })
60918275 247
180a60bc
DH
248/* [(x + y - 1) / y] suffers from an integer overflow, even though the
249 * computation should be possible in the given type. Therefore, we use
250 * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
251 * quotient and the remainder, so both should be equally fast. */
252#define DIV_ROUND_UP(_x, _y) \
117efe06 253 ({ \
180a60bc
DH
254 const typeof(_x) __x = (_x); \
255 const typeof(_y) __y = (_y); \
256 (__x / __y + !!(__x % __y)); \
257 })
258
d9fb7afb
FB
259#ifdef __COVERITY__
260
261/* Use special definitions of assertion macros in order to prevent
262 * false positives of ASSERT_SIDE_EFFECT on Coverity static analyzer
263 * for uses of assert_se() and assert_return().
264 *
265 * These definitions make expression go through a (trivial) function
266 * call to ensure they are not discarded. Also use ! or !! to ensure
267 * the boolean expressions are seen as such.
268 *
269 * This technique has been described and recommended in:
270 * https://community.synopsys.com/s/question/0D534000046Yuzb/suppressing-assertsideeffect-for-functions-that-allow-for-sideeffects
271 */
272
273extern void __coverity_panic__(void);
274
275static inline int __coverity_check__(int condition) {
276 return condition;
277}
278
279#define assert_message_se(expr, message) \
280 do { \
281 if (__coverity_check__(!(expr))) \
282 __coverity_panic__(); \
283 } while (false)
284
285#define assert_log(expr, message) __coverity_check__(!!(expr))
286
287#else /* ! __COVERITY__ */
288
34c38d2a 289#define assert_message_se(expr, message) \
dd8f71ee 290 do { \
93a46b0b 291 if (_unlikely_(!(expr))) \
34c38d2a
MS
292 log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
293 } while (false)
294
d9fb7afb
FB
295#define assert_log(expr, message) ((_likely_(expr)) \
296 ? (true) \
297 : (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
298
299#endif /* __COVERITY__ */
300
34c38d2a 301#define assert_se(expr) assert_message_se(expr, #expr)
dd8f71ee
LP
302
303/* We override the glibc assert() here. */
304#undef assert
305#ifdef NDEBUG
9ed794a3 306#define assert(expr) do {} while (false)
dd8f71ee 307#else
34c38d2a 308#define assert(expr) assert_message_se(expr, #expr)
dd8f71ee 309#endif
60918275 310
dd8f71ee
LP
311#define assert_not_reached(t) \
312 do { \
b7f33638 313 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
dd8f71ee 314 } while (false)
60918275 315
f791c684 316#if defined(static_assert)
7ebe131a
LP
317/* static_assert() is sometimes defined in a way that trips up
318 * -Wdeclaration-after-statement, hence let's temporarily turn off
319 * this warning around it. */
320#define assert_cc(expr) \
321 DISABLE_WARNING_DECLARATION_AFTER_STATEMENT; \
322 static_assert(expr, #expr); \
323 REENABLE_WARNING
f791c684 324#else
7ebe131a
LP
325#define assert_cc(expr) \
326 DISABLE_WARNING_DECLARATION_AFTER_STATEMENT; \
6825a04d 327 struct CONCATENATE(_assert_struct_, __COUNTER__) { \
7ebe131a
LP
328 char x[(expr) ? 0 : -1]; \
329 }; \
330 REENABLE_WARNING
f791c684 331#endif
60918275 332
80514f9c
LP
333#define assert_return(expr, r) \
334 do { \
34c38d2a 335 if (!assert_log(expr, #expr)) \
80514f9c 336 return (r); \
18387b59
LP
337 } while (false)
338
aa029628
TG
339#define assert_return_errno(expr, r, err) \
340 do { \
34c38d2a 341 if (!assert_log(expr, #expr)) { \
aa029628
TG
342 errno = err; \
343 return (r); \
344 } \
345 } while (false)
346
a3dc3547
KS
347#define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
348#define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
60918275 349#define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
a3dc3547 350#define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
60918275 351
a3dc3547
KS
352#define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
353#define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
c6c18be3 354#define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
a3dc3547 355#define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
c6c18be3 356
a3dc3547
KS
357#define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
358#define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
359#define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
360#define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
60918275 361
a3dc3547
KS
362#define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
363#define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
364#define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
365#define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
c6c18be3 366
74b2466e
LP
367#define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
368#define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
369
a9c55a88
LP
370#define CHAR_TO_STR(x) ((char[2]) { x, 0 })
371
034c6ed7
LP
372#define char_array_0(x) x[sizeof(x)-1] = 0;
373
fa70beaa
LP
374/* Returns the number of chars needed to format variables of the
375 * specified type as a decimal string. Adds in extra space for a
b7ce6b59
LP
376 * negative '-' prefix (hence works correctly on signed
377 * types). Includes space for the trailing NUL. */
fa70beaa 378#define DECIMAL_STR_MAX(type) \
5bcb0f2b 379 (2+(sizeof(type) <= 1 ? 3 : \
fa70beaa
LP
380 sizeof(type) <= 2 ? 5 : \
381 sizeof(type) <= 4 ? 10 : \
382 sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
383
0d1dbeb3
LP
384#define DECIMAL_STR_WIDTH(x) \
385 ({ \
386 typeof(x) _x_ = (x); \
387 unsigned ans = 1; \
ce2090ab 388 while ((_x_ /= 10) != 0) \
0d1dbeb3
LP
389 ans++; \
390 ans; \
391 })
392
264ad849
LP
393#define SET_FLAG(v, flag, b) \
394 (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
d94a24ca
ZJS
395#define FLAGS_SET(v, flags) \
396 (((v) & (flags)) == (flags))
264ad849 397
d5b26d50
DM
398#define CASE_F(X) case X:
399#define CASE_F_1(CASE, X) CASE_F(X)
400#define CASE_F_2(CASE, X, ...) CASE(X) CASE_F_1(CASE, __VA_ARGS__)
401#define CASE_F_3(CASE, X, ...) CASE(X) CASE_F_2(CASE, __VA_ARGS__)
402#define CASE_F_4(CASE, X, ...) CASE(X) CASE_F_3(CASE, __VA_ARGS__)
403#define CASE_F_5(CASE, X, ...) CASE(X) CASE_F_4(CASE, __VA_ARGS__)
404#define CASE_F_6(CASE, X, ...) CASE(X) CASE_F_5(CASE, __VA_ARGS__)
405#define CASE_F_7(CASE, X, ...) CASE(X) CASE_F_6(CASE, __VA_ARGS__)
406#define CASE_F_8(CASE, X, ...) CASE(X) CASE_F_7(CASE, __VA_ARGS__)
407#define CASE_F_9(CASE, X, ...) CASE(X) CASE_F_8(CASE, __VA_ARGS__)
408#define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
409#define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
410#define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
411#define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
412#define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
413#define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
414#define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
415#define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
416#define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
417#define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
418#define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
419
420#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
421#define FOR_EACH_MAKE_CASE(...) \
422 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, \
423 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) \
424 (CASE_F,__VA_ARGS__)
425
426#define IN_SET(x, ...) \
427 ({ \
428 bool _found = false; \
429 /* If the build breaks in the line below, you need to extend the case macros */ \
430 static _unused_ char _static_assert__macros_need_to_be_extended[20 - sizeof((int[]){__VA_ARGS__})/sizeof(int)]; \
431 switch(x) { \
432 FOR_EACH_MAKE_CASE(__VA_ARGS__) \
433 _found = true; \
434 break; \
435 default: \
436 break; \
437 } \
438 _found; \
cabb7806
LP
439 })
440
35aa04e9
LP
441#define SWAP_TWO(x, y) do { \
442 typeof(x) _t = (x); \
443 (x) = (y); \
444 (y) = (_t); \
445 } while (false)
446
919ce0b7
SL
447/* Define C11 thread_local attribute even on older gcc compiler
448 * version */
ec202eae
SL
449#ifndef thread_local
450/*
451 * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
452 * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
453 */
454#if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
455#define thread_local _Thread_local
456#else
457#define thread_local __thread
458#endif
459#endif
cabb7806 460
a2341f68
ZJS
461#define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func) \
462 static inline void func##p(type *p) { \
463 if (*p) \
464 func(*p); \
f6a8265b 465 }
a2341f68 466
dd8f71ee 467#include "log.h"