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