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_attr_(a,b) __attribute__ ((format (printf, a, b)))
  31 #define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
  32 #define _sentinel_ __attribute__ ((sentinel))
  33 #define _noreturn_ __attribute__((noreturn))
  34 #define _unused_ __attribute__ ((unused))
  35 #define _destructor_ __attribute__ ((destructor))
  36 #define _pure_ __attribute__ ((pure))
  37 #define _const_ __attribute__ ((const))
  38 #define _deprecated_ __attribute__ ((deprecated))
  39 #define _packed_ __attribute__ ((packed))
  40 #define _malloc_ __attribute__ ((malloc))
  41 #define _weak_ __attribute__ ((weak))
  42 #define _likely_(x) (__builtin_expect(!!(x),1))
  43 #define _unlikely_(x) (__builtin_expect(!!(x),0))
  44 #define _public_ __attribute__ ((visibility("default")))
  45 #define _hidden_ __attribute__ ((visibility("hidden")))
  46 #define _weakref_(x) __attribute__((weakref(#x)))
  47 #define _introspect_(x) __attribute__((section("introspect." x)))
  48 #define _alignas_(x) __attribute__((aligned(__alignof(x))))
  49 #define _cleanup_(x) __attribute__((cleanup(x)))
  50
  51 /* automake test harness */
  52 #define EXIT_TEST_SKIP 77
  53
  54 #define XSTRINGIFY(x) #x
  55 #define STRINGIFY(x) XSTRINGIFY(x)
  56
  57 /* Rounds up */
  58
  59 #define ALIGN4(l) (((l) + 3) & ~3)
  60 #define ALIGN8(l) (((l) + 7) & ~7)
  61
  62 #if __SIZEOF_POINTER__ == 8
  63 #define ALIGN(l) ALIGN8(l)
  64 #elif __SIZEOF_POINTER__ == 4
  65 #define ALIGN(l) ALIGN4(l)
  66 #else
  67 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
  68 #endif
  69
  70 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
  71 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
  72 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
  73
  74 static inline size_t ALIGN_TO(size_t l, size_t ali) {
  75         return ((l + ali - 1) & ~(ali - 1));
  76 }
  77
  78 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p))
  79
  80 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
  81
  82 /*
  83  * container_of - cast a member of a structure out to the containing structure
  84  * @ptr: the pointer to the member.
  85  * @type: the type of the container struct this is embedded in.
  86  * @member: the name of the member within the struct.
  87  *
  88  */
  89 #define container_of(ptr, type, member)                                 \
  90         __extension__ ({                                                \
  91                         const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  92                         (type *)( (char *)__mptr - offsetof(type,member) ); \
  93                 })
  94
  95 #undef MAX
  96 #define MAX(a,b)                                 \
  97         __extension__ ({                         \
  98                         typeof(a) _a = (a);      \
  99                         typeof(b) _b = (b);      \
 100                         _a > _b ? _a : _b;       \
 101                 })
 102
 103 #define MAX3(x,y,z)                              \
 104         __extension__ ({                         \
 105                         typeof(x) _c = MAX(x,y); \
 106                         MAX(_c, z);              \
 107                 })
 108
 109 #undef MIN
 110 #define MIN(a,b)                                \
 111         __extension__ ({                        \
 112                         typeof(a) _a = (a);     \
 113                         typeof(b) _b = (b);     \
 114                         _a < _b ? _a : _b;      \
 115                 })
 116
 117 #ifndef CLAMP
 118 #define CLAMP(x, low, high)                                             \
 119         __extension__ ({                                                \
 120                         typeof(x) _x = (x);                             \
 121                         typeof(low) _low = (low);                       \
 122                         typeof(high) _high = (high);                    \
 123                         ((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
 124                 })
 125 #endif
 126
 127 #define assert_se(expr)                                                 \
 128         do {                                                            \
 129                 if (_unlikely_(!(expr)))                                \
 130                         log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 131         } while (false)                                                 \
 132
 133 /* We override the glibc assert() here. */
 134 #undef assert
 135 #ifdef NDEBUG
 136 #define assert(expr) do {} while(false)
 137 #else
 138 #define assert(expr) assert_se(expr)
 139 #endif
 140
 141 #define assert_not_reached(t)                                           \
 142         do {                                                            \
 143                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 144         } while (false)
 145
 146 #if defined(static_assert)
 147 #define assert_cc(expr)                         \
 148         do {                                    \
 149                 static_assert(expr, #expr);     \
 150         } while (false)
 151 #else
 152 #define assert_cc(expr)                         \
 153         do {                                    \
 154                 switch (0) {                    \
 155                 case 0:                         \
 156                 case !!(expr):                  \
 157                         ;                       \
 158                 }                               \
 159         } while (false)
 160 #endif
 161
 162 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 163 #define UINT_TO_PTR(u) ((void*) ((uintptr_t) (u)))
 164
 165 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 166 #define UINT32_TO_PTR(u) ((void*) ((uintptr_t) (u)))
 167
 168 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 169 #define ULONG_TO_PTR(u) ((void*) ((uintptr_t) (u)))
 170
 171 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 172 #define INT_TO_PTR(u) ((void*) ((intptr_t) (u)))
 173
 174 #define TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 175 #define INT32_TO_PTR(u) ((void*) ((intptr_t) (u)))
 176
 177 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 178 #define LONG_TO_PTR(u) ((void*) ((intptr_t) (u)))
 179
 180 #define memzero(x,l) (memset((x), 0, (l)))
 181 #define zero(x) (memzero(&(x), sizeof(x)))
 182
 183 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 184
 185 #define char_array_0(x) x[sizeof(x)-1] = 0;
 186
 187 #define IOVEC_SET_STRING(i, s)                  \
 188         do {                                    \
 189                 struct iovec *_i = &(i);        \
 190                 char *_s = (char *)(s);         \
 191                 _i->iov_base = _s;              \
 192                 _i->iov_len = strlen(_s);       \
 193         } while(false)
 194
 195 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
 196         unsigned j;
 197         size_t r = 0;
 198
 199         for (j = 0; j < n; j++)
 200                 r += i[j].iov_len;
 201
 202         return r;
 203 }
 204
 205 static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 206         unsigned j;
 207
 208         for (j = 0; j < n; j++) {
 209                 size_t sub;
 210
 211                 if (_unlikely_(k <= 0))
 212                         break;
 213
 214                 sub = MIN(i[j].iov_len, k);
 215                 i[j].iov_len -= sub;
 216                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
 217                 k -= sub;
 218         }
 219
 220         return k;
 221 }
 222
 223 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 224 do {                                                                    \
 225         int _argtypes[128];                                             \
 226         size_t _i, _k;                                                  \
 227         _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
 228         assert(_k < ELEMENTSOF(_argtypes));                             \
 229         for (_i = 0; _i < _k; _i++) {                                   \
 230                 if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
 231                         (void) va_arg(ap, void*);                       \
 232                         continue;                                       \
 233                 }                                                       \
 234                                                                         \
 235                 switch (_argtypes[_i]) {                                \
 236                 case PA_INT:                                            \
 237                 case PA_INT|PA_FLAG_SHORT:                              \
 238                 case PA_CHAR:                                           \
 239                         (void) va_arg(ap, int);                         \
 240                         break;                                          \
 241                 case PA_INT|PA_FLAG_LONG:                               \
 242                         (void) va_arg(ap, long int);                    \
 243                         break;                                          \
 244                 case PA_INT|PA_FLAG_LONG_LONG:                          \
 245                         (void) va_arg(ap, long long int);               \
 246                         break;                                          \
 247                 case PA_WCHAR:                                          \
 248                         (void) va_arg(ap, wchar_t);                     \
 249                         break;                                          \
 250                 case PA_WSTRING:                                        \
 251                 case PA_STRING:                                         \
 252                 case PA_POINTER:                                        \
 253                         (void) va_arg(ap, void*);                       \
 254                         break;                                          \
 255                 case PA_FLOAT:                                          \
 256                 case PA_DOUBLE:                                         \
 257                         (void) va_arg(ap, double);                      \
 258                         break;                                          \
 259                 case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
 260                         (void) va_arg(ap, long double);                 \
 261                         break;                                          \
 262                 default:                                                \
 263                         assert_not_reached("Unknown format string argument."); \
 264                 }                                                       \
 265         }                                                               \
 266 } while(false)
 267
 268  /* Because statfs.t_type can be int on some architecures, we have to cast
 269   * the const magic to the type, otherwise the compiler warns about
 270   * signed/unsigned comparison, because the magic can be 32 bit unsigned.
 271  */
 272 #define F_TYPE_CMP(a, b) (a == (typeof(a)) b)
 273
 274
 275 /* Returns the number of chars needed to format variables of the
 276  * specified type as a decimal string. Adds in extra space for a
 277  * negative '-' prefix. */
 278
 279 #define DECIMAL_STR_MAX(type)                                           \
 280         (1+(sizeof(type) <= 1 ? 3 :                                     \
 281             sizeof(type) <= 2 ? 5 :                                     \
 282             sizeof(type) <= 4 ? 10 :                                    \
 283             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 284
 285 #include "log.h"