src/basic/macro.h

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