src/shared/macro.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #pragma once
   4
   5 /***
   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 ***/
  23
  24 #include <assert.h>
  25 #include <sys/param.h>
  26 #include <sys/types.h>
  27 #include <sys/uio.h>
  28 #include <inttypes.h>
  29
  30 #define _printf_(a,b) __attribute__ ((format (printf, a, b)))
  31 #define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
  32 #define _sentinel_ __attribute__ ((sentinel))
  33 #define _unused_ __attribute__ ((unused))
  34 #define _destructor_ __attribute__ ((destructor))
  35 #define _pure_ __attribute__ ((pure))
  36 #define _const_ __attribute__ ((const))
  37 #define _deprecated_ __attribute__ ((deprecated))
  38 #define _packed_ __attribute__ ((packed))
  39 #define _malloc_ __attribute__ ((malloc))
  40 #define _weak_ __attribute__ ((weak))
  41 #define _likely_(x) (__builtin_expect(!!(x),1))
  42 #define _unlikely_(x) (__builtin_expect(!!(x),0))
  43 #define _public_ __attribute__ ((visibility("default")))
  44 #define _hidden_ __attribute__ ((visibility("hidden")))
  45 #define _weakref_(x) __attribute__((weakref(#x)))
  46 #define _alignas_(x) __attribute__((aligned(__alignof(x))))
  47 #define _cleanup_(x) __attribute__((cleanup(x)))
  48
  49 /* Temporarily disable some warnings */
  50 #define DISABLE_WARNING_DECLARATION_AFTER_STATEMENT                     \
  51         _Pragma("GCC diagnostic push");                                 \
  52         _Pragma("GCC diagnostic ignored \"-Wdeclaration-after-statement\"")
  53
  54 #define DISABLE_WARNING_FORMAT_NONLITERAL                               \
  55         _Pragma("GCC diagnostic push");                                 \
  56         _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
  57
  58 #define DISABLE_WARNING_MISSING_PROTOTYPES                              \
  59         _Pragma("GCC diagnostic push");                                 \
  60         _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
  61
  62 #define DISABLE_WARNING_NONNULL                                         \
  63         _Pragma("GCC diagnostic push");                                 \
  64         _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
  65
  66 #define DISABLE_WARNING_SHADOW                                          \
  67         _Pragma("GCC diagnostic push");                                 \
  68         _Pragma("GCC diagnostic ignored \"-Wshadow\"")
  69
  70 #define REENABLE_WARNING                                                \
  71         _Pragma("GCC diagnostic pop")
  72
  73 /* automake test harness */
  74 #define EXIT_TEST_SKIP 77
  75
  76 #define XSTRINGIFY(x) #x
  77 #define STRINGIFY(x) XSTRINGIFY(x)
  78
  79 #define XCONCATENATE(x, y) x ## y
  80 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  81
  82 #define UNIQUE(prefix) CONCATENATE(prefix, __LINE__)
  83
  84 /* Rounds up */
  85
  86 #define ALIGN4(l) (((l) + 3) & ~3)
  87 #define ALIGN8(l) (((l) + 7) & ~7)
  88
  89 #if __SIZEOF_POINTER__ == 8
  90 #define ALIGN(l) ALIGN8(l)
  91 #elif __SIZEOF_POINTER__ == 4
  92 #define ALIGN(l) ALIGN4(l)
  93 #else
  94 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
  95 #endif
  96
  97 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
  98 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
  99 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
 100
 101 static inline size_t ALIGN_TO(size_t l, size_t ali) {
 102         return ((l + ali - 1) & ~(ali - 1));
 103 }
 104
 105 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p, ali))
 106
 107 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
 108 static inline unsigned long ALIGN_POWER2(unsigned long u) {
 109         /* clz(0) is undefined */
 110         if (u == 1)
 111                 return 1;
 112
 113         /* left-shift overflow is undefined */
 114         if (__builtin_clzl(u - 1UL) < 1)
 115                 return 0;
 116
 117         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
 118 }
 119
 120 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 121
 122 /*
 123  * container_of - cast a member of a structure out to the containing structure
 124  * @ptr: the pointer to the member.
 125  * @type: the type of the container struct this is embedded in.
 126  * @member: the name of the member within the struct.
 127  *
 128  */
 129 #define container_of(ptr, type, member)                                 \
 130         __extension__ ({                                                \
 131                         const typeof( ((type *)0)->member ) *__mptr = (ptr); \
 132                         (type *)( (char *)__mptr - offsetof(type,member) ); \
 133                 })
 134
 135 #undef MAX
 136 #define MAX(a,b)                                 \
 137         __extension__ ({                         \
 138                         typeof(a) _a = (a);      \
 139                         typeof(b) _b = (b);      \
 140                         _a > _b ? _a : _b;       \
 141                 })
 142
 143 #define MAX3(x,y,z)                              \
 144         __extension__ ({                         \
 145                         typeof(x) _c = MAX(x,y); \
 146                         MAX(_c, z);              \
 147                 })
 148
 149 #undef MIN
 150 #define MIN(a,b)                                \
 151         __extension__ ({                        \
 152                         typeof(a) _a = (a);     \
 153                         typeof(b) _b = (b);     \
 154                         _a < _b ? _a : _b;      \
 155                 })
 156
 157 #define MIN3(x,y,z)                              \
 158         __extension__ ({                         \
 159                         typeof(x) _c = MIN(x,y); \
 160                         MIN(_c, z);              \
 161                 })
 162
 163 #define LESS_BY(A,B)                            \
 164         __extension__ ({                        \
 165                         typeof(A) _A = (A);     \
 166                         typeof(B) _B = (B);     \
 167                         _A > _B ? _A - _B : 0;  \
 168                 })
 169
 170 #ifndef CLAMP
 171 #define CLAMP(x, low, high)                                             \
 172         __extension__ ({                                                \
 173                         typeof(x) _x = (x);                             \
 174                         typeof(low) _low = (low);                       \
 175                         typeof(high) _high = (high);                    \
 176                         ((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
 177                 })
 178 #endif
 179
 180 #define assert_se(expr)                                                 \
 181         do {                                                            \
 182                 if (_unlikely_(!(expr)))                                \
 183                         log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 184         } while (false)                                                 \
 185
 186 /* We override the glibc assert() here. */
 187 #undef assert
 188 #ifdef NDEBUG
 189 #define assert(expr) do {} while(false)
 190 #else
 191 #define assert(expr) assert_se(expr)
 192 #endif
 193
 194 #define assert_not_reached(t)                                           \
 195         do {                                                            \
 196                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 197         } while (false)
 198
 199 #if defined(static_assert)
 200 /* static_assert() is sometimes defined in a way that trips up
 201  * -Wdeclaration-after-statement, hence let's temporarily turn off
 202  * this warning around it. */
 203 #define assert_cc(expr)                                                 \
 204         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 205         static_assert(expr, #expr);                                     \
 206         REENABLE_WARNING
 207 #else
 208 #define assert_cc(expr)                                                 \
 209         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 210         struct UNIQUE(_assert_struct_) {                                \
 211                 char x[(expr) ? 0 : -1];                                \
 212         };                                                              \
 213         REENABLE_WARNING
 214 #endif
 215
 216 #define assert_return(expr, r)                                          \
 217         do {                                                            \
 218                 if (_unlikely_(!(expr))) {                              \
 219                         log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 220                         return (r);                                     \
 221                 }                                                       \
 222         } while (false)
 223
 224 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 225 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 226 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 227 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 228
 229 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 230 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 231 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 232 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 233
 234 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 235 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 236 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 237 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 238
 239 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 240 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 241 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 242 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 243
 244 #define memzero(x,l) (memset((x), 0, (l)))
 245 #define zero(x) (memzero(&(x), sizeof(x)))
 246
 247 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 248
 249 #define char_array_0(x) x[sizeof(x)-1] = 0;
 250
 251 #define IOVEC_SET_STRING(i, s)                  \
 252         do {                                    \
 253                 struct iovec *_i = &(i);        \
 254                 char *_s = (char *)(s);         \
 255                 _i->iov_base = _s;              \
 256                 _i->iov_len = strlen(_s);       \
 257         } while(false)
 258
 259 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
 260         unsigned j;
 261         size_t r = 0;
 262
 263         for (j = 0; j < n; j++)
 264                 r += i[j].iov_len;
 265
 266         return r;
 267 }
 268
 269 static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 270         unsigned j;
 271
 272         for (j = 0; j < n; j++) {
 273                 size_t sub;
 274
 275                 if (_unlikely_(k <= 0))
 276                         break;
 277
 278                 sub = MIN(i[j].iov_len, k);
 279                 i[j].iov_len -= sub;
 280                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
 281                 k -= sub;
 282         }
 283
 284         return k;
 285 }
 286
 287 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 288 do {                                                                    \
 289         int _argtypes[128];                                             \
 290         size_t _i, _k;                                                  \
 291         _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
 292         assert(_k < ELEMENTSOF(_argtypes));                             \
 293         for (_i = 0; _i < _k; _i++) {                                   \
 294                 if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
 295                         (void) va_arg(ap, void*);                       \
 296                         continue;                                       \
 297                 }                                                       \
 298                                                                         \
 299                 switch (_argtypes[_i]) {                                \
 300                 case PA_INT:                                            \
 301                 case PA_INT|PA_FLAG_SHORT:                              \
 302                 case PA_CHAR:                                           \
 303                         (void) va_arg(ap, int);                         \
 304                         break;                                          \
 305                 case PA_INT|PA_FLAG_LONG:                               \
 306                         (void) va_arg(ap, long int);                    \
 307                         break;                                          \
 308                 case PA_INT|PA_FLAG_LONG_LONG:                          \
 309                         (void) va_arg(ap, long long int);               \
 310                         break;                                          \
 311                 case PA_WCHAR:                                          \
 312                         (void) va_arg(ap, wchar_t);                     \
 313                         break;                                          \
 314                 case PA_WSTRING:                                        \
 315                 case PA_STRING:                                         \
 316                 case PA_POINTER:                                        \
 317                         (void) va_arg(ap, void*);                       \
 318                         break;                                          \
 319                 case PA_FLOAT:                                          \
 320                 case PA_DOUBLE:                                         \
 321                         (void) va_arg(ap, double);                      \
 322                         break;                                          \
 323                 case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
 324                         (void) va_arg(ap, long double);                 \
 325                         break;                                          \
 326                 default:                                                \
 327                         assert_not_reached("Unknown format string argument."); \
 328                 }                                                       \
 329         }                                                               \
 330 } while(false)
 331
 332  /* Because statfs.t_type can be int on some architectures, we have to cast
 333   * the const magic to the type, otherwise the compiler warns about
 334   * signed/unsigned comparison, because the magic can be 32 bit unsigned.
 335  */
 336 #define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
 337
 338 /* Returns the number of chars needed to format variables of the
 339  * specified type as a decimal string. Adds in extra space for a
 340  * negative '-' prefix. */
 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 SET_FLAG(v, flag, b) \
 348         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 349
 350 #define IN_SET(x, y, ...)                                               \
 351         ({                                                              \
 352                 const typeof(y) _y = (y);                               \
 353                 const typeof(_y) _x = (x);                              \
 354                 unsigned _i;                                            \
 355                 bool _found = false;                                    \
 356                 for (_i = 0; _i < 1 + sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
 357                         if (((const typeof(_x)[]) { _y, __VA_ARGS__ })[_i] == _x) { \
 358                                 _found = true;                          \
 359                                 break;                                  \
 360                         }                                               \
 361                 _found;                                                 \
 362         })
 363
 364 /* Define C11 thread_local attribute even on older gcc compiler
 365  * version */
 366 #ifndef thread_local
 367 /*
 368  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 369  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 370  */
 371 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 372 #define thread_local _Thread_local
 373 #else
 374 #define thread_local __thread
 375 #endif
 376 #endif
 377
 378 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
 379  * compiler versions */
 380 #ifndef noreturn
 381 #if __STDC_VERSION__ >= 201112L
 382 #define noreturn _Noreturn
 383 #else
 384 #define noreturn __attribute__((noreturn))
 385 #endif
 386 #endif
 387
 388 #include "log.h"