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 REENABLE_WARNING                                                \
  67         _Pragma("GCC diagnostic pop")
  68
  69 /* automake test harness */
  70 #define EXIT_TEST_SKIP 77
  71
  72 #define XSTRINGIFY(x) #x
  73 #define STRINGIFY(x) XSTRINGIFY(x)
  74
  75 #define XCONCATENATE(x, y) x ## y
  76 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  77
  78 #define UNIQUE(prefix) CONCATENATE(prefix, __LINE__)
  79
  80 /* Rounds up */
  81
  82 #define ALIGN4(l) (((l) + 3) & ~3)
  83 #define ALIGN8(l) (((l) + 7) & ~7)
  84
  85 #if __SIZEOF_POINTER__ == 8
  86 #define ALIGN(l) ALIGN8(l)
  87 #elif __SIZEOF_POINTER__ == 4
  88 #define ALIGN(l) ALIGN4(l)
  89 #else
  90 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
  91 #endif
  92
  93 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
  94 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
  95 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
  96
  97 static inline size_t ALIGN_TO(size_t l, size_t ali) {
  98         return ((l + ali - 1) & ~(ali - 1));
  99 }
 100
 101 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p, ali))
 102
 103 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 104
 105 /*
 106  * container_of - cast a member of a structure out to the containing structure
 107  * @ptr: the pointer to the member.
 108  * @type: the type of the container struct this is embedded in.
 109  * @member: the name of the member within the struct.
 110  *
 111  */
 112 #define container_of(ptr, type, member)                                 \
 113         __extension__ ({                                                \
 114                         const typeof( ((type *)0)->member ) *__mptr = (ptr); \
 115                         (type *)( (char *)__mptr - offsetof(type,member) ); \
 116                 })
 117
 118 #undef MAX
 119 #define MAX(a,b)                                 \
 120         __extension__ ({                         \
 121                         typeof(a) _a = (a);      \
 122                         typeof(b) _b = (b);      \
 123                         _a > _b ? _a : _b;       \
 124                 })
 125
 126 #define MAX3(x,y,z)                              \
 127         __extension__ ({                         \
 128                         typeof(x) _c = MAX(x,y); \
 129                         MAX(_c, z);              \
 130                 })
 131
 132 #undef MIN
 133 #define MIN(a,b)                                \
 134         __extension__ ({                        \
 135                         typeof(a) _a = (a);     \
 136                         typeof(b) _b = (b);     \
 137                         _a < _b ? _a : _b;      \
 138                 })
 139
 140 #define LESS_BY(A,B)                            \
 141         __extension__ ({                        \
 142                         typeof(A) _A = (A);     \
 143                         typeof(B) _B = (B);     \
 144                         _A > _B ? _A - _B : 0;  \
 145                 })
 146
 147 #ifndef CLAMP
 148 #define CLAMP(x, low, high)                                             \
 149         __extension__ ({                                                \
 150                         typeof(x) _x = (x);                             \
 151                         typeof(low) _low = (low);                       \
 152                         typeof(high) _high = (high);                    \
 153                         ((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
 154                 })
 155 #endif
 156
 157 #define assert_se(expr)                                                 \
 158         do {                                                            \
 159                 if (_unlikely_(!(expr)))                                \
 160                         log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 161         } while (false)                                                 \
 162
 163 /* We override the glibc assert() here. */
 164 #undef assert
 165 #ifdef NDEBUG
 166 #define assert(expr) do {} while(false)
 167 #else
 168 #define assert(expr) assert_se(expr)
 169 #endif
 170
 171 #define assert_not_reached(t)                                           \
 172         do {                                                            \
 173                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 174         } while (false)
 175
 176 #if defined(static_assert)
 177 /* static_assert() is sometimes defined in a way that trips up
 178  * -Wdeclaration-after-statement, hence let's temporarily turn off
 179  * this warning around it. */
 180 #define assert_cc(expr)                                                 \
 181         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 182         static_assert(expr, #expr);                                     \
 183         REENABLE_WARNING
 184 #else
 185 #define assert_cc(expr)                                                 \
 186         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 187         struct UNIQUE(_assert_struct_) {                                \
 188                 char x[(expr) ? 0 : -1];                                \
 189         };                                                              \
 190         REENABLE_WARNING
 191 #endif
 192
 193 #define assert_return(expr, r)                                          \
 194         do {                                                            \
 195                 if (_unlikely_(!(expr))) {                              \
 196                         log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 197                         return (r);                                     \
 198                 }                                                       \
 199         } while (false)
 200
 201 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 202 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 203 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 204 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 205
 206 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 207 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 208 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 209 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 210
 211 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 212 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 213 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 214 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 215
 216 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 217 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 218 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 219 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 220
 221 #define memzero(x,l) (memset((x), 0, (l)))
 222 #define zero(x) (memzero(&(x), sizeof(x)))
 223
 224 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 225
 226 #define char_array_0(x) x[sizeof(x)-1] = 0;
 227
 228 #define IOVEC_SET_STRING(i, s)                  \
 229         do {                                    \
 230                 struct iovec *_i = &(i);        \
 231                 char *_s = (char *)(s);         \
 232                 _i->iov_base = _s;              \
 233                 _i->iov_len = strlen(_s);       \
 234         } while(false)
 235
 236 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
 237         unsigned j;
 238         size_t r = 0;
 239
 240         for (j = 0; j < n; j++)
 241                 r += i[j].iov_len;
 242
 243         return r;
 244 }
 245
 246 static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 247         unsigned j;
 248
 249         for (j = 0; j < n; j++) {
 250                 size_t sub;
 251
 252                 if (_unlikely_(k <= 0))
 253                         break;
 254
 255                 sub = MIN(i[j].iov_len, k);
 256                 i[j].iov_len -= sub;
 257                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
 258                 k -= sub;
 259         }
 260
 261         return k;
 262 }
 263
 264 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 265 do {                                                                    \
 266         int _argtypes[128];                                             \
 267         size_t _i, _k;                                                  \
 268         _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
 269         assert(_k < ELEMENTSOF(_argtypes));                             \
 270         for (_i = 0; _i < _k; _i++) {                                   \
 271                 if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
 272                         (void) va_arg(ap, void*);                       \
 273                         continue;                                       \
 274                 }                                                       \
 275                                                                         \
 276                 switch (_argtypes[_i]) {                                \
 277                 case PA_INT:                                            \
 278                 case PA_INT|PA_FLAG_SHORT:                              \
 279                 case PA_CHAR:                                           \
 280                         (void) va_arg(ap, int);                         \
 281                         break;                                          \
 282                 case PA_INT|PA_FLAG_LONG:                               \
 283                         (void) va_arg(ap, long int);                    \
 284                         break;                                          \
 285                 case PA_INT|PA_FLAG_LONG_LONG:                          \
 286                         (void) va_arg(ap, long long int);               \
 287                         break;                                          \
 288                 case PA_WCHAR:                                          \
 289                         (void) va_arg(ap, wchar_t);                     \
 290                         break;                                          \
 291                 case PA_WSTRING:                                        \
 292                 case PA_STRING:                                         \
 293                 case PA_POINTER:                                        \
 294                         (void) va_arg(ap, void*);                       \
 295                         break;                                          \
 296                 case PA_FLOAT:                                          \
 297                 case PA_DOUBLE:                                         \
 298                         (void) va_arg(ap, double);                      \
 299                         break;                                          \
 300                 case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
 301                         (void) va_arg(ap, long double);                 \
 302                         break;                                          \
 303                 default:                                                \
 304                         assert_not_reached("Unknown format string argument."); \
 305                 }                                                       \
 306         }                                                               \
 307 } while(false)
 308
 309  /* Because statfs.t_type can be int on some architectures, we have to cast
 310   * the const magic to the type, otherwise the compiler warns about
 311   * signed/unsigned comparison, because the magic can be 32 bit unsigned.
 312  */
 313 #define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
 314
 315 /* Returns the number of chars needed to format variables of the
 316  * specified type as a decimal string. Adds in extra space for a
 317  * negative '-' prefix. */
 318 #define DECIMAL_STR_MAX(type)                                           \
 319         (2+(sizeof(type) <= 1 ? 3 :                                     \
 320             sizeof(type) <= 2 ? 5 :                                     \
 321             sizeof(type) <= 4 ? 10 :                                    \
 322             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 323
 324 #define SET_FLAG(v, flag, b) \
 325         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 326
 327 #define IN_SET(x, y, ...)                                               \
 328         ({                                                              \
 329                 const typeof(y) _y = (y);                               \
 330                 const typeof(_y) _x = (x);                              \
 331                 unsigned _i;                                            \
 332                 bool _found = false;                                    \
 333                 for (_i = 0; _i < 1 + sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
 334                         if (((const typeof(_x)[]) { _y, __VA_ARGS__ })[_i] == _x) { \
 335                                 _found = true;                          \
 336                                 break;                                  \
 337                         }                                               \
 338                 _found;                                                 \
 339         })
 340
 341 /* Define C11 thread_local attribute even on older gcc compiler
 342  * version */
 343 #ifndef thread_local
 344 /*
 345  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 346  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 347  */
 348 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 349 #define thread_local _Thread_local
 350 #else
 351 #define thread_local __thread
 352 #endif
 353 #endif
 354
 355 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
 356  * compiler versions */
 357 #ifndef noreturn
 358 #if __STDC_VERSION__ >= 201112L
 359 #define noreturn _Noreturn
 360 #else
 361 #define noreturn __attribute__((noreturn))
 362 #endif
 363 #endif
 364
 365 #include "log.h"