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 _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 _alignas_(x) __attribute__((aligned(__alignof(x))))
  48 #define _cleanup_(x) __attribute__((cleanup(x)))
  49
  50 /* automake test harness */
  51 #define EXIT_TEST_SKIP 77
  52
  53 #define XSTRINGIFY(x) #x
  54 #define STRINGIFY(x) XSTRINGIFY(x)
  55
  56 #define XCONCATENATE(x, y) x ## y
  57 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  58
  59 #define UNIQUE(prefix) CONCATENATE(prefix, __LINE__)
  60
  61 /* Rounds up */
  62
  63 #define ALIGN4(l) (((l) + 3) & ~3)
  64 #define ALIGN8(l) (((l) + 7) & ~7)
  65
  66 #if __SIZEOF_POINTER__ == 8
  67 #define ALIGN(l) ALIGN8(l)
  68 #elif __SIZEOF_POINTER__ == 4
  69 #define ALIGN(l) ALIGN4(l)
  70 #else
  71 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
  72 #endif
  73
  74 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
  75 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
  76 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
  77
  78 static inline size_t ALIGN_TO(size_t l, size_t ali) {
  79         return ((l + ali - 1) & ~(ali - 1));
  80 }
  81
  82 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p))
  83
  84 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
  85
  86 /*
  87  * container_of - cast a member of a structure out to the containing structure
  88  * @ptr: the pointer to the member.
  89  * @type: the type of the container struct this is embedded in.
  90  * @member: the name of the member within the struct.
  91  *
  92  */
  93 #define container_of(ptr, type, member)                                 \
  94         __extension__ ({                                                \
  95                         const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  96                         (type *)( (char *)__mptr - offsetof(type,member) ); \
  97                 })
  98
  99 #undef MAX
 100 #define MAX(a,b)                                 \
 101         __extension__ ({                         \
 102                         typeof(a) _a = (a);      \
 103                         typeof(b) _b = (b);      \
 104                         _a > _b ? _a : _b;       \
 105                 })
 106
 107 #define MAX3(x,y,z)                              \
 108         __extension__ ({                         \
 109                         typeof(x) _c = MAX(x,y); \
 110                         MAX(_c, z);              \
 111                 })
 112
 113 #undef MIN
 114 #define MIN(a,b)                                \
 115         __extension__ ({                        \
 116                         typeof(a) _a = (a);     \
 117                         typeof(b) _b = (b);     \
 118                         _a < _b ? _a : _b;      \
 119                 })
 120
 121 #ifndef CLAMP
 122 #define CLAMP(x, low, high)                                             \
 123         __extension__ ({                                                \
 124                         typeof(x) _x = (x);                             \
 125                         typeof(low) _low = (low);                       \
 126                         typeof(high) _high = (high);                    \
 127                         ((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
 128                 })
 129 #endif
 130
 131 #define assert_se(expr)                                                 \
 132         do {                                                            \
 133                 if (_unlikely_(!(expr)))                                \
 134                         log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 135         } while (false)                                                 \
 136
 137 /* We override the glibc assert() here. */
 138 #undef assert
 139 #ifdef NDEBUG
 140 #define assert(expr) do {} while(false)
 141 #else
 142 #define assert(expr) assert_se(expr)
 143 #endif
 144
 145 #define assert_not_reached(t)                                           \
 146         do {                                                            \
 147                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 148         } while (false)
 149
 150 #if defined(static_assert)
 151 #define assert_cc(expr) static_assert(expr, #expr)
 152 #else
 153 #define assert_cc(expr) struct UNIQUE(_assert_struct_) { char x[(expr) ? 0 : -1]; };
 154 #endif
 155
 156 #define assert_return(expr, r)                    \
 157         do {                                      \
 158                 if (_unlikely_(!(expr)))          \
 159                         return (r);               \
 160         } while (false)
 161
 162 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 163 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 164 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 165 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 166
 167 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 168 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 169 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 170 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 171
 172 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 173 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 174 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 175 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 176
 177 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 178 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 179 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 180 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 181
 182 #define memzero(x,l) (memset((x), 0, (l)))
 183 #define zero(x) (memzero(&(x), sizeof(x)))
 184
 185 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 186
 187 #define char_array_0(x) x[sizeof(x)-1] = 0;
 188
 189 #define IOVEC_SET_STRING(i, s)                  \
 190         do {                                    \
 191                 struct iovec *_i = &(i);        \
 192                 char *_s = (char *)(s);         \
 193                 _i->iov_base = _s;              \
 194                 _i->iov_len = strlen(_s);       \
 195         } while(false)
 196
 197 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
 198         unsigned j;
 199         size_t r = 0;
 200
 201         for (j = 0; j < n; j++)
 202                 r += i[j].iov_len;
 203
 204         return r;
 205 }
 206
 207 static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 208         unsigned j;
 209
 210         for (j = 0; j < n; j++) {
 211                 size_t sub;
 212
 213                 if (_unlikely_(k <= 0))
 214                         break;
 215
 216                 sub = MIN(i[j].iov_len, k);
 217                 i[j].iov_len -= sub;
 218                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
 219                 k -= sub;
 220         }
 221
 222         return k;
 223 }
 224
 225 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 226 do {                                                                    \
 227         int _argtypes[128];                                             \
 228         size_t _i, _k;                                                  \
 229         _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
 230         assert(_k < ELEMENTSOF(_argtypes));                             \
 231         for (_i = 0; _i < _k; _i++) {                                   \
 232                 if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
 233                         (void) va_arg(ap, void*);                       \
 234                         continue;                                       \
 235                 }                                                       \
 236                                                                         \
 237                 switch (_argtypes[_i]) {                                \
 238                 case PA_INT:                                            \
 239                 case PA_INT|PA_FLAG_SHORT:                              \
 240                 case PA_CHAR:                                           \
 241                         (void) va_arg(ap, int);                         \
 242                         break;                                          \
 243                 case PA_INT|PA_FLAG_LONG:                               \
 244                         (void) va_arg(ap, long int);                    \
 245                         break;                                          \
 246                 case PA_INT|PA_FLAG_LONG_LONG:                          \
 247                         (void) va_arg(ap, long long int);               \
 248                         break;                                          \
 249                 case PA_WCHAR:                                          \
 250                         (void) va_arg(ap, wchar_t);                     \
 251                         break;                                          \
 252                 case PA_WSTRING:                                        \
 253                 case PA_STRING:                                         \
 254                 case PA_POINTER:                                        \
 255                         (void) va_arg(ap, void*);                       \
 256                         break;                                          \
 257                 case PA_FLOAT:                                          \
 258                 case PA_DOUBLE:                                         \
 259                         (void) va_arg(ap, double);                      \
 260                         break;                                          \
 261                 case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
 262                         (void) va_arg(ap, long double);                 \
 263                         break;                                          \
 264                 default:                                                \
 265                         assert_not_reached("Unknown format string argument."); \
 266                 }                                                       \
 267         }                                                               \
 268 } while(false)
 269
 270  /* Because statfs.t_type can be int on some architectures, we have to cast
 271   * the const magic to the type, otherwise the compiler warns about
 272   * signed/unsigned comparison, because the magic can be 32 bit unsigned.
 273  */
 274 #define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
 275
 276 /* Returns the number of chars needed to format variables of the
 277  * specified type as a decimal string. Adds in extra space for a
 278  * negative '-' prefix. */
 279 #define DECIMAL_STR_MAX(type)                                           \
 280         (2+(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 #define SET_FLAG(v, flag, b) \
 286         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 287
 288 #define IN_SET(x, ...)                                                  \
 289         ({                                                              \
 290                 const typeof(x) _x = (x);                               \
 291                 unsigned _i;                                            \
 292                 bool _found = false;                                    \
 293                 for (_i = 0; _i < sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
 294                         if (((const typeof(_x)[]) { __VA_ARGS__ })[_i] == _x) { \
 295                                 _found = true;                          \
 296                                 break;                                  \
 297                         }                                               \
 298                 _found;                                                 \
 299         })
 300
 301
 302 #include "log.h"