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 /* automake test harness */
  50 #define EXIT_TEST_SKIP 77
  51
  52 #define XSTRINGIFY(x) #x
  53 #define STRINGIFY(x) XSTRINGIFY(x)
  54
  55 #define XCONCATENATE(x, y) x ## y
  56 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  57
  58 #define UNIQUE(prefix) CONCATENATE(prefix, __LINE__)
  59
  60 /* Rounds up */
  61
  62 #define ALIGN4(l) (((l) + 3) & ~3)
  63 #define ALIGN8(l) (((l) + 7) & ~7)
  64
  65 #if __SIZEOF_POINTER__ == 8
  66 #define ALIGN(l) ALIGN8(l)
  67 #elif __SIZEOF_POINTER__ == 4
  68 #define ALIGN(l) ALIGN4(l)
  69 #else
  70 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
  71 #endif
  72
  73 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
  74 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
  75 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
  76
  77 static inline size_t ALIGN_TO(size_t l, size_t ali) {
  78         return ((l + ali - 1) & ~(ali - 1));
  79 }
  80
  81 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p))
  82
  83 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
  84
  85 /*
  86  * container_of - cast a member of a structure out to the containing structure
  87  * @ptr: the pointer to the member.
  88  * @type: the type of the container struct this is embedded in.
  89  * @member: the name of the member within the struct.
  90  *
  91  */
  92 #define container_of(ptr, type, member)                                 \
  93         __extension__ ({                                                \
  94                         const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  95                         (type *)( (char *)__mptr - offsetof(type,member) ); \
  96                 })
  97
  98 #undef MAX
  99 #define MAX(a,b)                                 \
 100         __extension__ ({                         \
 101                         typeof(a) _a = (a);      \
 102                         typeof(b) _b = (b);      \
 103                         _a > _b ? _a : _b;       \
 104                 })
 105
 106 #define MAX3(x,y,z)                              \
 107         __extension__ ({                         \
 108                         typeof(x) _c = MAX(x,y); \
 109                         MAX(_c, z);              \
 110                 })
 111
 112 #undef MIN
 113 #define MIN(a,b)                                \
 114         __extension__ ({                        \
 115                         typeof(a) _a = (a);     \
 116                         typeof(b) _b = (b);     \
 117                         _a < _b ? _a : _b;      \
 118                 })
 119
 120 #define LESS_BY(A,B)                            \
 121         __extension__ ({                        \
 122                         typeof(A) _A = (A);     \
 123                         typeof(B) _B = (B);     \
 124                         _A > _B ? _A - _B : 0;  \
 125                 })
 126
 127 #ifndef CLAMP
 128 #define CLAMP(x, low, high)                                             \
 129         __extension__ ({                                                \
 130                         typeof(x) _x = (x);                             \
 131                         typeof(low) _low = (low);                       \
 132                         typeof(high) _high = (high);                    \
 133                         ((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
 134                 })
 135 #endif
 136
 137 #define assert_se(expr)                                                 \
 138         do {                                                            \
 139                 if (_unlikely_(!(expr)))                                \
 140                         log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 141         } while (false)                                                 \
 142
 143 /* We override the glibc assert() here. */
 144 #undef assert
 145 #ifdef NDEBUG
 146 #define assert(expr) do {} while(false)
 147 #else
 148 #define assert(expr) assert_se(expr)
 149 #endif
 150
 151 #define assert_not_reached(t)                                           \
 152         do {                                                            \
 153                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 154         } while (false)
 155
 156 #if defined(static_assert)
 157 #define assert_cc(expr) static_assert(expr, #expr)
 158 #else
 159 #define assert_cc(expr) struct UNIQUE(_assert_struct_) { char x[(expr) ? 0 : -1]; };
 160 #endif
 161
 162 #define assert_return(expr, r)                                          \
 163         do {                                                            \
 164                 if (_unlikely_(!(expr))) {                              \
 165                         log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 166                         return (r);                                     \
 167                 }                                                       \
 168         } while (false)
 169
 170 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 171 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 172 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 173 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 174
 175 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 176 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 177 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 178 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 179
 180 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 181 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 182 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 183 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 184
 185 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 186 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 187 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 188 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 189
 190 #define memzero(x,l) (memset((x), 0, (l)))
 191 #define zero(x) (memzero(&(x), sizeof(x)))
 192
 193 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 194
 195 #define char_array_0(x) x[sizeof(x)-1] = 0;
 196
 197 #define IOVEC_SET_STRING(i, s)                  \
 198         do {                                    \
 199                 struct iovec *_i = &(i);        \
 200                 char *_s = (char *)(s);         \
 201                 _i->iov_base = _s;              \
 202                 _i->iov_len = strlen(_s);       \
 203         } while(false)
 204
 205 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
 206         unsigned j;
 207         size_t r = 0;
 208
 209         for (j = 0; j < n; j++)
 210                 r += i[j].iov_len;
 211
 212         return r;
 213 }
 214
 215 static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 216         unsigned j;
 217
 218         for (j = 0; j < n; j++) {
 219                 size_t sub;
 220
 221                 if (_unlikely_(k <= 0))
 222                         break;
 223
 224                 sub = MIN(i[j].iov_len, k);
 225                 i[j].iov_len -= sub;
 226                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
 227                 k -= sub;
 228         }
 229
 230         return k;
 231 }
 232
 233 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 234 do {                                                                    \
 235         int _argtypes[128];                                             \
 236         size_t _i, _k;                                                  \
 237         _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
 238         assert(_k < ELEMENTSOF(_argtypes));                             \
 239         for (_i = 0; _i < _k; _i++) {                                   \
 240                 if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
 241                         (void) va_arg(ap, void*);                       \
 242                         continue;                                       \
 243                 }                                                       \
 244                                                                         \
 245                 switch (_argtypes[_i]) {                                \
 246                 case PA_INT:                                            \
 247                 case PA_INT|PA_FLAG_SHORT:                              \
 248                 case PA_CHAR:                                           \
 249                         (void) va_arg(ap, int);                         \
 250                         break;                                          \
 251                 case PA_INT|PA_FLAG_LONG:                               \
 252                         (void) va_arg(ap, long int);                    \
 253                         break;                                          \
 254                 case PA_INT|PA_FLAG_LONG_LONG:                          \
 255                         (void) va_arg(ap, long long int);               \
 256                         break;                                          \
 257                 case PA_WCHAR:                                          \
 258                         (void) va_arg(ap, wchar_t);                     \
 259                         break;                                          \
 260                 case PA_WSTRING:                                        \
 261                 case PA_STRING:                                         \
 262                 case PA_POINTER:                                        \
 263                         (void) va_arg(ap, void*);                       \
 264                         break;                                          \
 265                 case PA_FLOAT:                                          \
 266                 case PA_DOUBLE:                                         \
 267                         (void) va_arg(ap, double);                      \
 268                         break;                                          \
 269                 case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
 270                         (void) va_arg(ap, long double);                 \
 271                         break;                                          \
 272                 default:                                                \
 273                         assert_not_reached("Unknown format string argument."); \
 274                 }                                                       \
 275         }                                                               \
 276 } while(false)
 277
 278  /* Because statfs.t_type can be int on some architectures, we have to cast
 279   * the const magic to the type, otherwise the compiler warns about
 280   * signed/unsigned comparison, because the magic can be 32 bit unsigned.
 281  */
 282 #define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
 283
 284 /* Returns the number of chars needed to format variables of the
 285  * specified type as a decimal string. Adds in extra space for a
 286  * negative '-' prefix. */
 287 #define DECIMAL_STR_MAX(type)                                           \
 288         (2+(sizeof(type) <= 1 ? 3 :                                     \
 289             sizeof(type) <= 2 ? 5 :                                     \
 290             sizeof(type) <= 4 ? 10 :                                    \
 291             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 292
 293 #define SET_FLAG(v, flag, b) \
 294         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 295
 296 #define IN_SET(x, ...)                                                  \
 297         ({                                                              \
 298                 const typeof(x) _x = (x);                               \
 299                 unsigned _i;                                            \
 300                 bool _found = false;                                    \
 301                 for (_i = 0; _i < sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
 302                         if (((const typeof(_x)[]) { __VA_ARGS__ })[_i] == _x) { \
 303                                 _found = true;                          \
 304                                 break;                                  \
 305                         }                                               \
 306                 _found;                                                 \
 307         })
 308
 309 /* Define C11 thread_local attribute even on older gcc compiler
 310  * version */
 311 #ifndef thread_local
 312 /*
 313  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 314  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 315  */
 316 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 317 #define thread_local _Thread_local
 318 #else
 319 #define thread_local __thread
 320 #endif
 321 #endif
 322
 323 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
 324  * compiler versions */
 325 #ifndef noreturn
 326 #if __STDC_VERSION__ >= 201112L
 327 #define noreturn _Noreturn
 328 #else
 329 #define noreturn __attribute__((noreturn))
 330 #endif
 331 #endif
 332
 333 #include "log.h"