src/basic/macro.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8 ***/
   9
  10 #include <inttypes.h>
  11 #include <stdbool.h>
  12 #include <sys/param.h>
  13 #include <sys/sysmacros.h>
  14 #include <sys/types.h>
  15
  16 #define _printf_(a,b) __attribute__ ((format (printf, a, b)))
  17 #ifdef __clang__
  18 #  define _alloc_(...)
  19 #else
  20 #  define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
  21 #endif
  22 #define _sentinel_ __attribute__ ((sentinel))
  23 #define _unused_ __attribute__ ((unused))
  24 #define _destructor_ __attribute__ ((destructor))
  25 #define _pure_ __attribute__ ((pure))
  26 #define _const_ __attribute__ ((const))
  27 #define _deprecated_ __attribute__ ((deprecated))
  28 #define _packed_ __attribute__ ((packed))
  29 #define _malloc_ __attribute__ ((malloc))
  30 #define _weak_ __attribute__ ((weak))
  31 #define _likely_(x) (__builtin_expect(!!(x),1))
  32 #define _unlikely_(x) (__builtin_expect(!!(x),0))
  33 #define _public_ __attribute__ ((visibility("default")))
  34 #define _hidden_ __attribute__ ((visibility("hidden")))
  35 #define _weakref_(x) __attribute__((weakref(#x)))
  36 #define _alignas_(x) __attribute__((aligned(__alignof(x))))
  37 #define _cleanup_(x) __attribute__((cleanup(x)))
  38 #if __GNUC__ >= 7
  39 #define _fallthrough_ __attribute__((fallthrough))
  40 #else
  41 #define _fallthrough_
  42 #endif
  43 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
  44  * compiler versions */
  45 #ifndef _noreturn_
  46 #if __STDC_VERSION__ >= 201112L
  47 #define _noreturn_ _Noreturn
  48 #else
  49 #define _noreturn_ __attribute__((noreturn))
  50 #endif
  51 #endif
  52
  53 #if !defined(HAS_FEATURE_MEMORY_SANITIZER)
  54 #  if defined(__has_feature)
  55 #    if __has_feature(memory_sanitizer)
  56 #      define HAS_FEATURE_MEMORY_SANITIZER 1
  57 #    endif
  58 #  endif
  59 #  if !defined(HAS_FEATURE_MEMORY_SANITIZER)
  60 #    define HAS_FEATURE_MEMORY_SANITIZER 0
  61 #  endif
  62 #endif
  63
  64 /* Temporarily disable some warnings */
  65 #define DISABLE_WARNING_DECLARATION_AFTER_STATEMENT                     \
  66         _Pragma("GCC diagnostic push");                                 \
  67         _Pragma("GCC diagnostic ignored \"-Wdeclaration-after-statement\"")
  68
  69 #define DISABLE_WARNING_FORMAT_NONLITERAL                               \
  70         _Pragma("GCC diagnostic push");                                 \
  71         _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
  72
  73 #define DISABLE_WARNING_MISSING_PROTOTYPES                              \
  74         _Pragma("GCC diagnostic push");                                 \
  75         _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
  76
  77 #define DISABLE_WARNING_NONNULL                                         \
  78         _Pragma("GCC diagnostic push");                                 \
  79         _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
  80
  81 #define DISABLE_WARNING_SHADOW                                          \
  82         _Pragma("GCC diagnostic push");                                 \
  83         _Pragma("GCC diagnostic ignored \"-Wshadow\"")
  84
  85 #define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
  86         _Pragma("GCC diagnostic push");                                 \
  87         _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
  88
  89 #define REENABLE_WARNING                                                \
  90         _Pragma("GCC diagnostic pop")
  91
  92 /* automake test harness */
  93 #define EXIT_TEST_SKIP 77
  94
  95 #define XSTRINGIFY(x) #x
  96 #define STRINGIFY(x) XSTRINGIFY(x)
  97
  98 #define XCONCATENATE(x, y) x ## y
  99 #define CONCATENATE(x, y) XCONCATENATE(x, y)
 100
 101 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
 102 #define UNIQ __COUNTER__
 103
 104 /* builtins */
 105 #if __SIZEOF_INT__ == 4
 106 #define BUILTIN_FFS_U32(x) __builtin_ffs(x);
 107 #elif __SIZEOF_LONG__ == 4
 108 #define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
 109 #else
 110 #error "neither int nor long are four bytes long?!?"
 111 #endif
 112
 113 /* Rounds up */
 114
 115 #define ALIGN4(l) (((l) + 3) & ~3)
 116 #define ALIGN8(l) (((l) + 7) & ~7)
 117
 118 #if __SIZEOF_POINTER__ == 8
 119 #define ALIGN(l) ALIGN8(l)
 120 #elif __SIZEOF_POINTER__ == 4
 121 #define ALIGN(l) ALIGN4(l)
 122 #else
 123 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
 124 #endif
 125
 126 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
 127 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
 128 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
 129
 130 static inline size_t ALIGN_TO(size_t l, size_t ali) {
 131         return ((l + ali - 1) & ~(ali - 1));
 132 }
 133
 134 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
 135
 136 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
 137 static inline unsigned long ALIGN_POWER2(unsigned long u) {
 138         /* clz(0) is undefined */
 139         if (u == 1)
 140                 return 1;
 141
 142         /* left-shift overflow is undefined */
 143         if (__builtin_clzl(u - 1UL) < 1)
 144                 return 0;
 145
 146         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
 147 }
 148
 149 #ifndef __COVERITY__
 150 #  define VOID_0 ((void)0)
 151 #else
 152 #  define VOID_0 ((void*)0)
 153 #endif
 154
 155 #define ELEMENTSOF(x)                                                    \
 156         __extension__ (__builtin_choose_expr(                            \
 157                 !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
 158                 sizeof(x)/sizeof((x)[0]),                                \
 159                 VOID_0))
 160
 161 /*
 162  * STRLEN - return the length of a string literal, minus the trailing NUL byte.
 163  *          Contrary to strlen(), this is a constant expression.
 164  * @x: a string literal.
 165  */
 166 #define STRLEN(x) (sizeof(""x"") - 1)
 167
 168 /*
 169  * container_of - cast a member of a structure out to the containing structure
 170  * @ptr: the pointer to the member.
 171  * @type: the type of the container struct this is embedded in.
 172  * @member: the name of the member within the struct.
 173  */
 174 #define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
 175 #define __container_of(uniq, ptr, type, member)                         \
 176         __extension__ ({                                                \
 177                 const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
 178                 (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type,member) ); \
 179         })
 180
 181 #undef MAX
 182 #define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
 183 #define __MAX(aq, a, bq, b)                             \
 184         __extension__ ({                                \
 185                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 186                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 187                 UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
 188         })
 189
 190 /* evaluates to (void) if _A or _B are not constant or of different types */
 191 #define CONST_MAX(_A, _B) \
 192         __extension__ (__builtin_choose_expr(                           \
 193                 __builtin_constant_p(_A) &&                             \
 194                 __builtin_constant_p(_B) &&                             \
 195                 __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
 196                 ((_A) > (_B)) ? (_A) : (_B),                            \
 197                 VOID_0))
 198
 199 /* takes two types and returns the size of the larger one */
 200 #define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
 201
 202 #define MAX3(x,y,z)                                     \
 203         __extension__ ({                                \
 204                         const typeof(x) _c = MAX(x,y);  \
 205                         MAX(_c, z);                     \
 206                 })
 207
 208 #undef MIN
 209 #define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
 210 #define __MIN(aq, a, bq, b)                             \
 211         __extension__ ({                                \
 212                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 213                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 214                 UNIQ_T(A,aq) < UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
 215         })
 216
 217 #define MIN3(x,y,z)                                     \
 218         __extension__ ({                                \
 219                         const typeof(x) _c = MIN(x,y);  \
 220                         MIN(_c, z);                     \
 221                 })
 222
 223 #define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
 224 #define __LESS_BY(aq, a, bq, b)                         \
 225         __extension__ ({                                \
 226                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 227                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 228                 UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) - UNIQ_T(B,bq) : 0; \
 229         })
 230
 231 #undef CLAMP
 232 #define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
 233 #define __CLAMP(xq, x, lowq, low, highq, high)                          \
 234         __extension__ ({                                                \
 235                 const typeof(x) UNIQ_T(X,xq) = (x);                     \
 236                 const typeof(low) UNIQ_T(LOW,lowq) = (low);             \
 237                 const typeof(high) UNIQ_T(HIGH,highq) = (high);         \
 238                         UNIQ_T(X,xq) > UNIQ_T(HIGH,highq) ?             \
 239                                 UNIQ_T(HIGH,highq) :                    \
 240                                 UNIQ_T(X,xq) < UNIQ_T(LOW,lowq) ?       \
 241                                         UNIQ_T(LOW,lowq) :              \
 242                                         UNIQ_T(X,xq);                   \
 243         })
 244
 245 /* [(x + y - 1) / y] suffers from an integer overflow, even though the
 246  * computation should be possible in the given type. Therefore, we use
 247  * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
 248  * quotient and the remainder, so both should be equally fast. */
 249 #define DIV_ROUND_UP(_x, _y)                                            \
 250         __extension__ ({                                                \
 251                 const typeof(_x) __x = (_x);                            \
 252                 const typeof(_y) __y = (_y);                            \
 253                 (__x / __y + !!(__x % __y));                            \
 254         })
 255
 256 #define assert_message_se(expr, message)                                \
 257         do {                                                            \
 258                 if (_unlikely_(!(expr)))                                \
 259                         log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 260         } while (false)
 261
 262 #define assert_se(expr) assert_message_se(expr, #expr)
 263
 264 /* We override the glibc assert() here. */
 265 #undef assert
 266 #ifdef NDEBUG
 267 #define assert(expr) do {} while (false)
 268 #else
 269 #define assert(expr) assert_message_se(expr, #expr)
 270 #endif
 271
 272 #define assert_not_reached(t)                                           \
 273         do {                                                            \
 274                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 275         } while (false)
 276
 277 #if defined(static_assert)
 278 /* static_assert() is sometimes defined in a way that trips up
 279  * -Wdeclaration-after-statement, hence let's temporarily turn off
 280  * this warning around it. */
 281 #define assert_cc(expr)                                                 \
 282         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 283         static_assert(expr, #expr);                                     \
 284         REENABLE_WARNING
 285 #else
 286 #define assert_cc(expr)                                                 \
 287         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 288         struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
 289                 char x[(expr) ? 0 : -1];                                \
 290         };                                                              \
 291         REENABLE_WARNING
 292 #endif
 293
 294 #define assert_log(expr, message) ((_likely_(expr))                     \
 295         ? (true)                                                        \
 296         : (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
 297
 298 #define assert_return(expr, r)                                          \
 299         do {                                                            \
 300                 if (!assert_log(expr, #expr))                           \
 301                         return (r);                                     \
 302         } while (false)
 303
 304 #define assert_return_errno(expr, r, err)                               \
 305         do {                                                            \
 306                 if (!assert_log(expr, #expr)) {                         \
 307                         errno = err;                                    \
 308                         return (r);                                     \
 309                 }                                                       \
 310         } while (false)
 311
 312 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 313 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 314 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 315 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 316
 317 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 318 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 319 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 320 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 321
 322 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 323 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 324 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 325 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 326
 327 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 328 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 329 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 330 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 331
 332 #define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
 333 #define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 334
 335 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 336
 337 #define char_array_0(x) x[sizeof(x)-1] = 0;
 338
 339 /* Returns the number of chars needed to format variables of the
 340  * specified type as a decimal string. Adds in extra space for a
 341  * negative '-' prefix (hence works correctly on signed
 342  * types). Includes space for the trailing NUL. */
 343 #define DECIMAL_STR_MAX(type)                                           \
 344         (2+(sizeof(type) <= 1 ? 3 :                                     \
 345             sizeof(type) <= 2 ? 5 :                                     \
 346             sizeof(type) <= 4 ? 10 :                                    \
 347             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 348
 349 #define DECIMAL_STR_WIDTH(x)                            \
 350         ({                                              \
 351                 typeof(x) _x_ = (x);                    \
 352                 unsigned ans = 1;                       \
 353                 while ((_x_ /= 10) != 0)                \
 354                         ans++;                          \
 355                 ans;                                    \
 356         })
 357
 358 #define SET_FLAG(v, flag, b) \
 359         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 360 #define FLAGS_SET(v, flags) \
 361         (((v) & (flags)) == (flags))
 362
 363 #define CASE_F(X) case X:
 364 #define CASE_F_1(CASE, X) CASE_F(X)
 365 #define CASE_F_2(CASE, X, ...)  CASE(X) CASE_F_1(CASE, __VA_ARGS__)
 366 #define CASE_F_3(CASE, X, ...)  CASE(X) CASE_F_2(CASE, __VA_ARGS__)
 367 #define CASE_F_4(CASE, X, ...)  CASE(X) CASE_F_3(CASE, __VA_ARGS__)
 368 #define CASE_F_5(CASE, X, ...)  CASE(X) CASE_F_4(CASE, __VA_ARGS__)
 369 #define CASE_F_6(CASE, X, ...)  CASE(X) CASE_F_5(CASE, __VA_ARGS__)
 370 #define CASE_F_7(CASE, X, ...)  CASE(X) CASE_F_6(CASE, __VA_ARGS__)
 371 #define CASE_F_8(CASE, X, ...)  CASE(X) CASE_F_7(CASE, __VA_ARGS__)
 372 #define CASE_F_9(CASE, X, ...)  CASE(X) CASE_F_8(CASE, __VA_ARGS__)
 373 #define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
 374 #define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
 375 #define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
 376 #define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
 377 #define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
 378 #define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
 379 #define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
 380 #define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
 381 #define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
 382 #define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
 383 #define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
 384
 385 #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
 386 #define FOR_EACH_MAKE_CASE(...) \
 387         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, \
 388                                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) \
 389                    (CASE_F,__VA_ARGS__)
 390
 391 #define IN_SET(x, ...)                          \
 392         ({                                      \
 393                 bool _found = false;            \
 394                 /* If the build breaks in the line below, you need to extend the case macros */ \
 395                 static _unused_ char _static_assert__macros_need_to_be_extended[20 - sizeof((int[]){__VA_ARGS__})/sizeof(int)]; \
 396                 switch(x) {                     \
 397                 FOR_EACH_MAKE_CASE(__VA_ARGS__) \
 398                         _found = true;          \
 399                         break;                  \
 400                 default:                        \
 401                         break;                  \
 402                 }                               \
 403                 _found;                         \
 404         })
 405
 406 #define SWAP_TWO(x, y) do {                        \
 407                 typeof(x) _t = (x);                \
 408                 (x) = (y);                         \
 409                 (y) = (_t);                        \
 410         } while (false)
 411
 412 /* Define C11 thread_local attribute even on older gcc compiler
 413  * version */
 414 #ifndef thread_local
 415 /*
 416  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 417  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 418  */
 419 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 420 #define thread_local _Thread_local
 421 #else
 422 #define thread_local __thread
 423 #endif
 424 #endif
 425
 426 #define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
 427         static inline void func##p(type *p) {                   \
 428                 if (*p)                                         \
 429                         func(*p);                               \
 430         }
 431
 432 #include "log.h"