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 DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
  71         _Pragma("GCC diagnostic push");                                 \
  72         _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
  73
  74 #define REENABLE_WARNING                                                \
  75         _Pragma("GCC diagnostic pop")
  76
  77 /* automake test harness */
  78 #define EXIT_TEST_SKIP 77
  79
  80 #define XSTRINGIFY(x) #x
  81 #define STRINGIFY(x) XSTRINGIFY(x)
  82
  83 #define XCONCATENATE(x, y) x ## y
  84 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  85
  86 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
  87 #define UNIQ __COUNTER__
  88
  89 /* Rounds up */
  90
  91 #define ALIGN4(l) (((l) + 3) & ~3)
  92 #define ALIGN8(l) (((l) + 7) & ~7)
  93
  94 #if __SIZEOF_POINTER__ == 8
  95 #define ALIGN(l) ALIGN8(l)
  96 #elif __SIZEOF_POINTER__ == 4
  97 #define ALIGN(l) ALIGN4(l)
  98 #else
  99 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
 100 #endif
 101
 102 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
 103 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
 104 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
 105
 106 static inline size_t ALIGN_TO(size_t l, size_t ali) {
 107         return ((l + ali - 1) & ~(ali - 1));
 108 }
 109
 110 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
 111
 112 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
 113 static inline unsigned long ALIGN_POWER2(unsigned long u) {
 114         /* clz(0) is undefined */
 115         if (u == 1)
 116                 return 1;
 117
 118         /* left-shift overflow is undefined */
 119         if (__builtin_clzl(u - 1UL) < 1)
 120                 return 0;
 121
 122         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
 123 }
 124
 125 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 126
 127 /*
 128  * container_of - cast a member of a structure out to the containing structure
 129  * @ptr: the pointer to the member.
 130  * @type: the type of the container struct this is embedded in.
 131  * @member: the name of the member within the struct.
 132  */
 133 #define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
 134 #define __container_of(uniq, ptr, type, member)                         \
 135         __extension__ ({                                                \
 136                 const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
 137                 (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type,member) ); \
 138         })
 139
 140 #undef MAX
 141 #define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
 142 #define __MAX(aq, a, bq, b)                             \
 143         __extension__ ({                                \
 144                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 145                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 146                 UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
 147         })
 148
 149 /* evaluates to (void) if _A or _B are not constant or of different types */
 150 #define CONST_MAX(_A, _B) \
 151         __extension__ (__builtin_choose_expr(                           \
 152                 __builtin_constant_p(_A) &&                             \
 153                 __builtin_constant_p(_B) &&                             \
 154                 __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
 155                 ((_A) > (_B)) ? (_A) : (_B),                            \
 156                 (void)0))
 157
 158 /* takes two types and returns the size of the larger one */
 159 #define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
 160
 161 #define MAX3(x,y,z)                                     \
 162         __extension__ ({                                \
 163                         const typeof(x) _c = MAX(x,y);  \
 164                         MAX(_c, z);                     \
 165                 })
 166
 167 #undef MIN
 168 #define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
 169 #define __MIN(aq, a, bq, b)                             \
 170         __extension__ ({                                \
 171                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 172                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 173                 UNIQ_T(A,aq) < UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
 174         })
 175
 176 #define MIN3(x,y,z)                                     \
 177         __extension__ ({                                \
 178                         const typeof(x) _c = MIN(x,y);  \
 179                         MIN(_c, z);                     \
 180                 })
 181
 182 #define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
 183 #define __LESS_BY(aq, a, bq, b)                         \
 184         __extension__ ({                                \
 185                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 186                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 187                 UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) - UNIQ_T(B,bq) : 0; \
 188         })
 189
 190 #undef CLAMP
 191 #define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
 192 #define __CLAMP(xq, x, lowq, low, highq, high)                          \
 193         __extension__ ({                                                \
 194                 const typeof(x) UNIQ_T(X,xq) = (x);                     \
 195                 const typeof(low) UNIQ_T(LOW,lowq) = (low);             \
 196                 const typeof(high) UNIQ_T(HIGH,highq) = (high);         \
 197                         UNIQ_T(X,xq) > UNIQ_T(HIGH,highq) ?             \
 198                                 UNIQ_T(HIGH,highq) :                    \
 199                                 UNIQ_T(X,xq) < UNIQ_T(LOW,lowq) ?       \
 200                                         UNIQ_T(LOW,lowq) :              \
 201                                         UNIQ_T(X,xq);                   \
 202         })
 203
 204 /* [(x + y - 1) / y] suffers from an integer overflow, even though the
 205  * computation should be possible in the given type. Therefore, we use
 206  * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
 207  * quotient and the remainder, so both should be equally fast. */
 208 #define DIV_ROUND_UP(_x, _y)                                            \
 209         __extension__ ({                                                \
 210                 const typeof(_x) __x = (_x);                            \
 211                 const typeof(_y) __y = (_y);                            \
 212                 (__x / __y + !!(__x % __y));                            \
 213         })
 214
 215 #define assert_se(expr)                                                 \
 216         do {                                                            \
 217                 if (_unlikely_(!(expr)))                                \
 218                         log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 219         } while (false)                                                 \
 220
 221 /* We override the glibc assert() here. */
 222 #undef assert
 223 #ifdef NDEBUG
 224 #define assert(expr) do {} while(false)
 225 #else
 226 #define assert(expr) assert_se(expr)
 227 #endif
 228
 229 #define assert_not_reached(t)                                           \
 230         do {                                                            \
 231                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 232         } while (false)
 233
 234 #if defined(static_assert)
 235 /* static_assert() is sometimes defined in a way that trips up
 236  * -Wdeclaration-after-statement, hence let's temporarily turn off
 237  * this warning around it. */
 238 #define assert_cc(expr)                                                 \
 239         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 240         static_assert(expr, #expr);                                     \
 241         REENABLE_WARNING
 242 #else
 243 #define assert_cc(expr)                                                 \
 244         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
 245         struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
 246                 char x[(expr) ? 0 : -1];                                \
 247         };                                                              \
 248         REENABLE_WARNING
 249 #endif
 250
 251 #define assert_return(expr, r)                                          \
 252         do {                                                            \
 253                 if (_unlikely_(!(expr))) {                              \
 254                         log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 255                         return (r);                                     \
 256                 }                                                       \
 257         } while (false)
 258
 259 #define assert_return_errno(expr, r, err)                               \
 260         do {                                                            \
 261                 if (_unlikely_(!(expr))) {                              \
 262                         log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 263                         errno = err;                                    \
 264                         return (r);                                     \
 265                 }                                                       \
 266         } while (false)
 267
 268 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 269 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 270 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
 271 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 272
 273 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 274 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 275 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 276 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 277
 278 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 279 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 280 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 281 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 282
 283 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 284 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 285 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 286 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 287
 288 #define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
 289 #define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 290
 291 /* The following macros add 1 when converting things, since UID 0 is a
 292  * valid UID, while the pointer NULL is special */
 293 #define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1))
 294 #define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
 295
 296 #define PTR_TO_GID(p) ((gid_t) (((uintptr_t) (p))-1))
 297 #define GID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
 298
 299 #define memzero(x,l) (memset((x), 0, (l)))
 300 #define zero(x) (memzero(&(x), sizeof(x)))
 301
 302 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 303
 304 #define char_array_0(x) x[sizeof(x)-1] = 0;
 305
 306 #define IOVEC_SET_STRING(i, s)                  \
 307         do {                                    \
 308                 struct iovec *_i = &(i);        \
 309                 char *_s = (char *)(s);         \
 310                 _i->iov_base = _s;              \
 311                 _i->iov_len = strlen(_s);       \
 312         } while(false)
 313
 314 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
 315         unsigned j;
 316         size_t r = 0;
 317
 318         for (j = 0; j < n; j++)
 319                 r += i[j].iov_len;
 320
 321         return r;
 322 }
 323
 324 static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 325         unsigned j;
 326
 327         for (j = 0; j < n; j++) {
 328                 size_t sub;
 329
 330                 if (_unlikely_(k <= 0))
 331                         break;
 332
 333                 sub = MIN(i[j].iov_len, k);
 334                 i[j].iov_len -= sub;
 335                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
 336                 k -= sub;
 337         }
 338
 339         return k;
 340 }
 341
 342 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 343 do {                                                                    \
 344         int _argtypes[128];                                             \
 345         size_t _i, _k;                                                  \
 346         _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
 347         assert(_k < ELEMENTSOF(_argtypes));                             \
 348         for (_i = 0; _i < _k; _i++) {                                   \
 349                 if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
 350                         (void) va_arg(ap, void*);                       \
 351                         continue;                                       \
 352                 }                                                       \
 353                                                                         \
 354                 switch (_argtypes[_i]) {                                \
 355                 case PA_INT:                                            \
 356                 case PA_INT|PA_FLAG_SHORT:                              \
 357                 case PA_CHAR:                                           \
 358                         (void) va_arg(ap, int);                         \
 359                         break;                                          \
 360                 case PA_INT|PA_FLAG_LONG:                               \
 361                         (void) va_arg(ap, long int);                    \
 362                         break;                                          \
 363                 case PA_INT|PA_FLAG_LONG_LONG:                          \
 364                         (void) va_arg(ap, long long int);               \
 365                         break;                                          \
 366                 case PA_WCHAR:                                          \
 367                         (void) va_arg(ap, wchar_t);                     \
 368                         break;                                          \
 369                 case PA_WSTRING:                                        \
 370                 case PA_STRING:                                         \
 371                 case PA_POINTER:                                        \
 372                         (void) va_arg(ap, void*);                       \
 373                         break;                                          \
 374                 case PA_FLOAT:                                          \
 375                 case PA_DOUBLE:                                         \
 376                         (void) va_arg(ap, double);                      \
 377                         break;                                          \
 378                 case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
 379                         (void) va_arg(ap, long double);                 \
 380                         break;                                          \
 381                 default:                                                \
 382                         assert_not_reached("Unknown format string argument."); \
 383                 }                                                       \
 384         }                                                               \
 385 } while(false)
 386
 387  /* Because statfs.t_type can be int on some architectures, we have to cast
 388   * the const magic to the type, otherwise the compiler warns about
 389   * signed/unsigned comparison, because the magic can be 32 bit unsigned.
 390  */
 391 #define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
 392
 393 /* Returns the number of chars needed to format variables of the
 394  * specified type as a decimal string. Adds in extra space for a
 395  * negative '-' prefix (hence works correctly on signed
 396  * types). Includes space for the trailing NUL. */
 397 #define DECIMAL_STR_MAX(type)                                           \
 398         (2+(sizeof(type) <= 1 ? 3 :                                     \
 399             sizeof(type) <= 2 ? 5 :                                     \
 400             sizeof(type) <= 4 ? 10 :                                    \
 401             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 402
 403 #define SET_FLAG(v, flag, b) \
 404         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 405
 406 #define IN_SET(x, y, ...)                                               \
 407         ({                                                              \
 408                 const typeof(y) _y = (y);                               \
 409                 const typeof(_y) _x = (x);                              \
 410                 unsigned _i;                                            \
 411                 bool _found = false;                                    \
 412                 for (_i = 0; _i < 1 + sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
 413                         if (((const typeof(_x)[]) { _y, __VA_ARGS__ })[_i] == _x) { \
 414                                 _found = true;                          \
 415                                 break;                                  \
 416                         }                                               \
 417                 _found;                                                 \
 418         })
 419
 420 /* Return a nulstr for a standard cascade of configuration directories,
 421  * suitable to pass to conf_files_list_nulstr or config_parse_many. */
 422 #define CONF_DIRS_NULSTR(n) \
 423         "/etc/" n ".d\0" \
 424         "/run/" n ".d\0" \
 425         "/usr/local/lib/" n ".d\0" \
 426         "/usr/lib/" n ".d\0" \
 427         CONF_DIR_SPLIT_USR(n)
 428
 429 #ifdef HAVE_SPLIT_USR
 430 #define CONF_DIR_SPLIT_USR(n) "/lib/" n ".d\0"
 431 #else
 432 #define CONF_DIR_SPLIT_USR(n)
 433 #endif
 434
 435 /* Define C11 thread_local attribute even on older gcc compiler
 436  * version */
 437 #ifndef thread_local
 438 /*
 439  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 440  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 441  */
 442 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 443 #define thread_local _Thread_local
 444 #else
 445 #define thread_local __thread
 446 #endif
 447 #endif
 448
 449 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
 450  * compiler versions */
 451 #ifndef noreturn
 452 #if __STDC_VERSION__ >= 201112L
 453 #define noreturn _Noreturn
 454 #else
 455 #define noreturn __attribute__((noreturn))
 456 #endif
 457 #endif
 458
 459 #define UID_INVALID ((uid_t) -1)
 460 #define GID_INVALID ((gid_t) -1)
 461 #define MODE_INVALID ((mode_t) -1)
 462
 463 #define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
 464         static inline void func##p(type *p) {                   \
 465                 if (*p)                                         \
 466                         func(*p);                               \
 467         }                                                       \
 468         struct __useless_struct_to_allow_trailing_semicolon__
 469
 470 #include "log.h"