src/basic/macro.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <inttypes.h>
   7 #include <stdbool.h>
   8 #include <sys/param.h>
   9 #include <sys/sysmacros.h>
  10 #include <sys/types.h>
  11
  12 #define _printf_(a, b) __attribute__((__format__(printf, a, b)))
  13 #ifdef __clang__
  14 #  define _alloc_(...)
  15 #else
  16 #  define _alloc_(...) __attribute__((__alloc_size__(__VA_ARGS__)))
  17 #endif
  18 #define _sentinel_ __attribute__((__sentinel__))
  19 #define _section_(x) __attribute__((__section__(x)))
  20 #define _used_ __attribute__((__used__))
  21 #define _unused_ __attribute__((__unused__))
  22 #define _destructor_ __attribute__((__destructor__))
  23 #define _pure_ __attribute__((__pure__))
  24 #define _const_ __attribute__((__const__))
  25 #define _deprecated_ __attribute__((__deprecated__))
  26 #define _packed_ __attribute__((__packed__))
  27 #define _malloc_ __attribute__((__malloc__))
  28 #define _weak_ __attribute__((__weak__))
  29 #define _likely_(x) (__builtin_expect(!!(x), 1))
  30 #define _unlikely_(x) (__builtin_expect(!!(x), 0))
  31 #define _public_ __attribute__((__visibility__("default")))
  32 #define _hidden_ __attribute__((__visibility__("hidden")))
  33 #define _weakref_(x) __attribute__((__weakref__(#x)))
  34 #define _align_(x) __attribute__((__aligned__(x)))
  35 #define _alignas_(x) __attribute__((__aligned__(__alignof(x))))
  36 #define _alignptr_ __attribute__((__aligned__(sizeof(void*))))
  37 #define _cleanup_(x) __attribute__((__cleanup__(x)))
  38 #if __GNUC__ >= 7
  39 #define _fallthrough_ __attribute__((__fallthrough__))
  40 #else
  41 #define _fallthrough_
  42 #endif
  43 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
  44  * compiler versions */
  45 #ifndef _noreturn_
  46 #if __STDC_VERSION__ >= 201112L
  47 #define _noreturn_ _Noreturn
  48 #else
  49 #define _noreturn_ __attribute__((__noreturn__))
  50 #endif
  51 #endif
  52
  53 #if !defined(HAS_FEATURE_MEMORY_SANITIZER)
  54 #  if defined(__has_feature)
  55 #    if __has_feature(memory_sanitizer)
  56 #      define HAS_FEATURE_MEMORY_SANITIZER 1
  57 #    endif
  58 #  endif
  59 #  if !defined(HAS_FEATURE_MEMORY_SANITIZER)
  60 #    define HAS_FEATURE_MEMORY_SANITIZER 0
  61 #  endif
  62 #endif
  63
  64 #if !defined(HAS_FEATURE_ADDRESS_SANITIZER)
  65 #  ifdef __SANITIZE_ADDRESS__
  66 #      define HAS_FEATURE_ADDRESS_SANITIZER 1
  67 #  elif defined(__has_feature)
  68 #    if __has_feature(address_sanitizer)
  69 #      define HAS_FEATURE_ADDRESS_SANITIZER 1
  70 #    endif
  71 #  endif
  72 #  if !defined(HAS_FEATURE_ADDRESS_SANITIZER)
  73 #    define HAS_FEATURE_ADDRESS_SANITIZER 0
  74 #  endif
  75 #endif
  76
  77 /* Note: on GCC "no_sanitize_address" is a function attribute only, on llvm it may also be applied to global
  78  * variables. We define a specific macro which knows this. Note that on GCC we don't need this decorator so much, since
  79  * our primary usecase for this attribute is registration structures placed in named ELF sections which shall not be
  80  * padded, but GCC doesn't pad those anyway if AddressSanitizer is enabled. */
  81 #if HAS_FEATURE_ADDRESS_SANITIZER && defined(__clang__)
  82 #define _variable_no_sanitize_address_ __attribute__((__no_sanitize_address__))
  83 #else
  84 #define _variable_no_sanitize_address_
  85 #endif
  86
  87 /* Apparently there's no has_feature() call defined to check for ubsan, hence let's define this
  88  * unconditionally on llvm */
  89 #if defined(__clang__)
  90 #define _function_no_sanitize_float_cast_overflow_ __attribute__((no_sanitize("float-cast-overflow")))
  91 #else
  92 #define _function_no_sanitize_float_cast_overflow_
  93 #endif
  94
  95 /* Temporarily disable some warnings */
  96 #define DISABLE_WARNING_DEPRECATED_DECLARATIONS                         \
  97         _Pragma("GCC diagnostic push");                                 \
  98         _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
  99
 100 #define DISABLE_WARNING_FORMAT_NONLITERAL                               \
 101         _Pragma("GCC diagnostic push");                                 \
 102         _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
 103
 104 #define DISABLE_WARNING_MISSING_PROTOTYPES                              \
 105         _Pragma("GCC diagnostic push");                                 \
 106         _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
 107
 108 #define DISABLE_WARNING_NONNULL                                         \
 109         _Pragma("GCC diagnostic push");                                 \
 110         _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
 111
 112 #define DISABLE_WARNING_SHADOW                                          \
 113         _Pragma("GCC diagnostic push");                                 \
 114         _Pragma("GCC diagnostic ignored \"-Wshadow\"")
 115
 116 #define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
 117         _Pragma("GCC diagnostic push");                                 \
 118         _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
 119
 120 #if HAVE_WSTRINGOP_TRUNCATION
 121 #  define DISABLE_WARNING_STRINGOP_TRUNCATION                           \
 122         _Pragma("GCC diagnostic push");                                 \
 123         _Pragma("GCC diagnostic ignored \"-Wstringop-truncation\"")
 124 #else
 125 #  define DISABLE_WARNING_STRINGOP_TRUNCATION                           \
 126         _Pragma("GCC diagnostic push")
 127 #endif
 128
 129 #define DISABLE_WARNING_FLOAT_EQUAL \
 130         _Pragma("GCC diagnostic push");                                 \
 131         _Pragma("GCC diagnostic ignored \"-Wfloat-equal\"")
 132
 133 #define DISABLE_WARNING_TYPE_LIMITS \
 134         _Pragma("GCC diagnostic push");                                 \
 135         _Pragma("GCC diagnostic ignored \"-Wtype-limits\"")
 136
 137 #define REENABLE_WARNING                                                \
 138         _Pragma("GCC diagnostic pop")
 139
 140 /* automake test harness */
 141 #define EXIT_TEST_SKIP 77
 142
 143 #define XSTRINGIFY(x) #x
 144 #define STRINGIFY(x) XSTRINGIFY(x)
 145
 146 #define XCONCATENATE(x, y) x ## y
 147 #define CONCATENATE(x, y) XCONCATENATE(x, y)
 148
 149 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
 150 #define UNIQ __COUNTER__
 151
 152 /* builtins */
 153 #if __SIZEOF_INT__ == 4
 154 #define BUILTIN_FFS_U32(x) __builtin_ffs(x);
 155 #elif __SIZEOF_LONG__ == 4
 156 #define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
 157 #else
 158 #error "neither int nor long are four bytes long?!?"
 159 #endif
 160
 161 /* Rounds up */
 162
 163 #define ALIGN4(l) (((l) + 3) & ~3)
 164 #define ALIGN8(l) (((l) + 7) & ~7)
 165
 166 #if __SIZEOF_POINTER__ == 8
 167 #define ALIGN(l) ALIGN8(l)
 168 #elif __SIZEOF_POINTER__ == 4
 169 #define ALIGN(l) ALIGN4(l)
 170 #else
 171 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
 172 #endif
 173
 174 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
 175 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
 176 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
 177
 178 static inline size_t ALIGN_TO(size_t l, size_t ali) {
 179         return ((l + ali - 1) & ~(ali - 1));
 180 }
 181
 182 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
 183
 184 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
 185 static inline unsigned long ALIGN_POWER2(unsigned long u) {
 186
 187         /* Avoid subtraction overflow */
 188         if (u == 0)
 189                 return 0;
 190
 191         /* clz(0) is undefined */
 192         if (u == 1)
 193                 return 1;
 194
 195         /* left-shift overflow is undefined */
 196         if (__builtin_clzl(u - 1UL) < 1)
 197                 return 0;
 198
 199         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
 200 }
 201
 202 static inline size_t GREEDY_ALLOC_ROUND_UP(size_t l) {
 203         size_t m;
 204
 205         /* Round up allocation sizes a bit to some reasonable, likely larger value. This is supposed to be
 206          * used for cases which are likely called in an allocation loop of some form, i.e. that repetitively
 207          * grow stuff, for example strv_extend() and suchlike.
 208          *
 209          * Note the difference to GREEDY_REALLOC() here, as this helper operates on a single size value only,
 210          * and rounds up to next multiple of 2, needing no further counter.
 211          *
 212          * Note the benefits of direct ALIGN_POWER2() usage: type-safety for size_t, sane handling for very
 213          * small (i.e. <= 2) and safe handling for very large (i.e. > SSIZE_MAX) values. */
 214
 215         if (l <= 2)
 216                 return 2; /* Never allocate less than 2 of something.  */
 217
 218         m = ALIGN_POWER2(l);
 219         if (m == 0) /* overflow? */
 220                 return l;
 221
 222         return m;
 223 }
 224
 225 #ifndef __COVERITY__
 226 #  define VOID_0 ((void)0)
 227 #else
 228 #  define VOID_0 ((void*)0)
 229 #endif
 230
 231 #define ELEMENTSOF(x)                                                   \
 232         (__builtin_choose_expr(                                         \
 233                 !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
 234                 sizeof(x)/sizeof((x)[0]),                               \
 235                 VOID_0))
 236
 237 /*
 238  * STRLEN - return the length of a string literal, minus the trailing NUL byte.
 239  *          Contrary to strlen(), this is a constant expression.
 240  * @x: a string literal.
 241  */
 242 #define STRLEN(x) (sizeof(""x"") - 1)
 243
 244 /*
 245  * container_of - cast a member of a structure out to the containing structure
 246  * @ptr: the pointer to the member.
 247  * @type: the type of the container struct this is embedded in.
 248  * @member: the name of the member within the struct.
 249  */
 250 #define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
 251 #define __container_of(uniq, ptr, type, member)                         \
 252         ({                                                              \
 253                 const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
 254                 (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type, member) ); \
 255         })
 256
 257 #undef MAX
 258 #define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
 259 #define __MAX(aq, a, bq, b)                             \
 260         ({                                              \
 261                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 262                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 263                 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
 264         })
 265
 266 /* evaluates to (void) if _A or _B are not constant or of different types */
 267 #define CONST_MAX(_A, _B) \
 268         (__builtin_choose_expr(                                         \
 269                 __builtin_constant_p(_A) &&                             \
 270                 __builtin_constant_p(_B) &&                             \
 271                 __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
 272                 ((_A) > (_B)) ? (_A) : (_B),                            \
 273                 VOID_0))
 274
 275 /* takes two types and returns the size of the larger one */
 276 #define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
 277
 278 #define MAX3(x, y, z)                                   \
 279         ({                                              \
 280                 const typeof(x) _c = MAX(x, y);         \
 281                 MAX(_c, z);                             \
 282         })
 283
 284 #define MAX4(x, y, z, a)                                \
 285         ({                                              \
 286                 const typeof(x) _d = MAX3(x, y, z);     \
 287                 MAX(_d, a);                             \
 288         })
 289
 290 #undef MIN
 291 #define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
 292 #define __MIN(aq, a, bq, b)                             \
 293         ({                                              \
 294                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 295                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 296                 UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
 297         })
 298
 299 /* evaluates to (void) if _A or _B are not constant or of different types */
 300 #define CONST_MIN(_A, _B) \
 301         (__builtin_choose_expr(                                         \
 302                 __builtin_constant_p(_A) &&                             \
 303                 __builtin_constant_p(_B) &&                             \
 304                 __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
 305                 ((_A) < (_B)) ? (_A) : (_B),                            \
 306                 VOID_0))
 307
 308 #define MIN3(x, y, z)                                   \
 309         ({                                              \
 310                 const typeof(x) _c = MIN(x, y);         \
 311                 MIN(_c, z);                             \
 312         })
 313
 314 #define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
 315 #define __LESS_BY(aq, a, bq, b)                         \
 316         ({                                              \
 317                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 318                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 319                 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
 320         })
 321
 322 #define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
 323 #define __CMP(aq, a, bq, b)                             \
 324         ({                                              \
 325                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 326                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 327                 UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 :    \
 328                 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0;  \
 329         })
 330
 331 #undef CLAMP
 332 #define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
 333 #define __CLAMP(xq, x, lowq, low, highq, high)                          \
 334         ({                                                              \
 335                 const typeof(x) UNIQ_T(X, xq) = (x);                    \
 336                 const typeof(low) UNIQ_T(LOW, lowq) = (low);            \
 337                 const typeof(high) UNIQ_T(HIGH, highq) = (high);        \
 338                         UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ?           \
 339                                 UNIQ_T(HIGH, highq) :                   \
 340                                 UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ?     \
 341                                         UNIQ_T(LOW, lowq) :             \
 342                                         UNIQ_T(X, xq);                  \
 343         })
 344
 345 /* [(x + y - 1) / y] suffers from an integer overflow, even though the
 346  * computation should be possible in the given type. Therefore, we use
 347  * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
 348  * quotient and the remainder, so both should be equally fast. */
 349 #define DIV_ROUND_UP(x, y) __DIV_ROUND_UP(UNIQ, (x), UNIQ, (y))
 350 #define __DIV_ROUND_UP(xq, x, yq, y)                                    \
 351         ({                                                              \
 352                 const typeof(x) UNIQ_T(X, xq) = (x);                    \
 353                 const typeof(y) UNIQ_T(Y, yq) = (y);                    \
 354                 (UNIQ_T(X, xq) / UNIQ_T(Y, yq) + !!(UNIQ_T(X, xq) % UNIQ_T(Y, yq))); \
 355         })
 356
 357 #ifdef __COVERITY__
 358
 359 /* Use special definitions of assertion macros in order to prevent
 360  * false positives of ASSERT_SIDE_EFFECT on Coverity static analyzer
 361  * for uses of assert_se() and assert_return().
 362  *
 363  * These definitions make expression go through a (trivial) function
 364  * call to ensure they are not discarded. Also use ! or !! to ensure
 365  * the boolean expressions are seen as such.
 366  *
 367  * This technique has been described and recommended in:
 368  * https://community.synopsys.com/s/question/0D534000046Yuzb/suppressing-assertsideeffect-for-functions-that-allow-for-sideeffects
 369  */
 370
 371 extern void __coverity_panic__(void);
 372
 373 static inline void __coverity_check__(int condition) {
 374         if (!condition)
 375                 __coverity_panic__();
 376 }
 377
 378 static inline int __coverity_check_and_return__(int condition) {
 379         return condition;
 380 }
 381
 382 #define assert_message_se(expr, message) __coverity_check__(!!(expr))
 383
 384 #define assert_log(expr, message) __coverity_check_and_return__(!!(expr))
 385
 386 #else  /* ! __COVERITY__ */
 387
 388 #define assert_message_se(expr, message)                                \
 389         do {                                                            \
 390                 if (_unlikely_(!(expr)))                                \
 391                         log_assert_failed(message, PROJECT_FILE, __LINE__, __PRETTY_FUNCTION__); \
 392         } while (false)
 393
 394 #define assert_log(expr, message) ((_likely_(expr))                     \
 395         ? (true)                                                        \
 396         : (log_assert_failed_return(message, PROJECT_FILE, __LINE__, __PRETTY_FUNCTION__), false))
 397
 398 #endif  /* __COVERITY__ */
 399
 400 #define assert_se(expr) assert_message_se(expr, #expr)
 401
 402 /* We override the glibc assert() here. */
 403 #undef assert
 404 #ifdef NDEBUG
 405 #define assert(expr) do {} while (false)
 406 #else
 407 #define assert(expr) assert_message_se(expr, #expr)
 408 #endif
 409
 410 #define assert_not_reached(t)                                           \
 411         log_assert_failed_unreachable(t, PROJECT_FILE, __LINE__, __PRETTY_FUNCTION__)
 412
 413 #if defined(static_assert)
 414 #define assert_cc(expr)                                                 \
 415         static_assert(expr, #expr)
 416 #else
 417 #define assert_cc(expr)                                                 \
 418         struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
 419                 char x[(expr) ? 0 : -1];                                \
 420         }
 421 #endif
 422
 423 #define assert_return(expr, r)                                          \
 424         do {                                                            \
 425                 if (!assert_log(expr, #expr))                           \
 426                         return (r);                                     \
 427         } while (false)
 428
 429 #define assert_return_errno(expr, r, err)                               \
 430         do {                                                            \
 431                 if (!assert_log(expr, #expr)) {                         \
 432                         errno = err;                                    \
 433                         return (r);                                     \
 434                 }                                                       \
 435         } while (false)
 436
 437 #define return_with_errno(r, err)                     \
 438         do {                                          \
 439                 errno = abs(err);                     \
 440                 return r;                             \
 441         } while (false)
 442
 443 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 444 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 445 #define PTR_TO_UINT(p) ((unsigned) ((uintptr_t) (p)))
 446 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 447
 448 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 449 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 450 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 451 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 452
 453 #define PTR_TO_UINT8(p) ((uint8_t) ((uintptr_t) (p)))
 454 #define UINT8_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 455
 456 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 457 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 458 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 459 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 460
 461 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 462 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 463 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 464 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 465
 466 #define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
 467 #define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 468
 469 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 470
 471 #define char_array_0(x) x[sizeof(x)-1] = 0;
 472
 473 #define sizeof_field(struct_type, member) sizeof(((struct_type *) 0)->member)
 474
 475 /* Returns the number of chars needed to format variables of the
 476  * specified type as a decimal string. Adds in extra space for a
 477  * negative '-' prefix (hence works correctly on signed
 478  * types). Includes space for the trailing NUL. */
 479 #define DECIMAL_STR_MAX(type)                                           \
 480         (2+(sizeof(type) <= 1 ? 3 :                                     \
 481             sizeof(type) <= 2 ? 5 :                                     \
 482             sizeof(type) <= 4 ? 10 :                                    \
 483             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 484
 485 #define DECIMAL_STR_WIDTH(x)                            \
 486         ({                                              \
 487                 typeof(x) _x_ = (x);                    \
 488                 unsigned ans = 1;                       \
 489                 while ((_x_ /= 10) != 0)                \
 490                         ans++;                          \
 491                 ans;                                    \
 492         })
 493
 494 #define UPDATE_FLAG(orig, flag, b)                      \
 495         ((b) ? ((orig) | (flag)) : ((orig) & ~(flag)))
 496 #define SET_FLAG(v, flag, b) \
 497         (v) = UPDATE_FLAG(v, flag, b)
 498 #define FLAGS_SET(v, flags) \
 499         ((~(v) & (flags)) == 0)
 500
 501 #define CASE_F(X) case X:
 502 #define CASE_F_1(CASE, X) CASE_F(X)
 503 #define CASE_F_2(CASE, X, ...)  CASE(X) CASE_F_1(CASE, __VA_ARGS__)
 504 #define CASE_F_3(CASE, X, ...)  CASE(X) CASE_F_2(CASE, __VA_ARGS__)
 505 #define CASE_F_4(CASE, X, ...)  CASE(X) CASE_F_3(CASE, __VA_ARGS__)
 506 #define CASE_F_5(CASE, X, ...)  CASE(X) CASE_F_4(CASE, __VA_ARGS__)
 507 #define CASE_F_6(CASE, X, ...)  CASE(X) CASE_F_5(CASE, __VA_ARGS__)
 508 #define CASE_F_7(CASE, X, ...)  CASE(X) CASE_F_6(CASE, __VA_ARGS__)
 509 #define CASE_F_8(CASE, X, ...)  CASE(X) CASE_F_7(CASE, __VA_ARGS__)
 510 #define CASE_F_9(CASE, X, ...)  CASE(X) CASE_F_8(CASE, __VA_ARGS__)
 511 #define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
 512 #define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
 513 #define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
 514 #define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
 515 #define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
 516 #define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
 517 #define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
 518 #define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
 519 #define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
 520 #define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
 521 #define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
 522
 523 #define GET_CASE_F(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,NAME,...) NAME
 524 #define FOR_EACH_MAKE_CASE(...) \
 525         GET_CASE_F(__VA_ARGS__,CASE_F_20,CASE_F_19,CASE_F_18,CASE_F_17,CASE_F_16,CASE_F_15,CASE_F_14,CASE_F_13,CASE_F_12,CASE_F_11, \
 526                                CASE_F_10,CASE_F_9,CASE_F_8,CASE_F_7,CASE_F_6,CASE_F_5,CASE_F_4,CASE_F_3,CASE_F_2,CASE_F_1) \
 527                    (CASE_F,__VA_ARGS__)
 528
 529 #define IN_SET(x, ...)                          \
 530         ({                                      \
 531                 bool _found = false;            \
 532                 /* If the build breaks in the line below, you need to extend the case macros. (We use "long double" as  \
 533                  * type for the array, in the hope that checkers such as ubsan don't complain that the initializers for \
 534                  * the array are not representable by the base type. Ideally we'd use typeof(x) as base type, but that  \
 535                  * doesn't work, as we want to use this on bitfields and gcc refuses typeof() on bitfields.) */         \
 536                 static const long double __assert_in_set[] _unused_ = { __VA_ARGS__ }; \
 537                 assert_cc(ELEMENTSOF(__assert_in_set) <= 20); \
 538                 switch(x) {                     \
 539                 FOR_EACH_MAKE_CASE(__VA_ARGS__) \
 540                         _found = true;          \
 541                         break;                  \
 542                 default:                        \
 543                         break;                  \
 544                 }                               \
 545                 _found;                         \
 546         })
 547
 548 #define SWAP_TWO(x, y) do {                        \
 549                 typeof(x) _t = (x);                \
 550                 (x) = (y);                         \
 551                 (y) = (_t);                        \
 552         } while (false)
 553
 554 #define STRV_MAKE(...) ((char**) ((const char*[]) { __VA_ARGS__, NULL }))
 555 #define STRV_MAKE_EMPTY ((char*[1]) { NULL })
 556
 557 /* Pointers range from NULL to POINTER_MAX */
 558 #define POINTER_MAX ((void*) UINTPTR_MAX)
 559
 560 /* Iterates through a specified list of pointers. Accepts NULL pointers, but uses POINTER_MAX as internal marker for EOL. */
 561 #define FOREACH_POINTER(p, x, ...)                                                       \
 562         for (typeof(p) *_l = (typeof(p)[]) { ({ p = x; }), ##__VA_ARGS__, POINTER_MAX }; \
 563              p != (typeof(p)) POINTER_MAX;                                               \
 564              p = *(++_l))
 565
 566 /* Define C11 thread_local attribute even on older gcc compiler
 567  * version */
 568 #ifndef thread_local
 569 /*
 570  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 571  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 572  */
 573 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 574 #define thread_local _Thread_local
 575 #else
 576 #define thread_local __thread
 577 #endif
 578 #endif
 579
 580 #define DEFINE_TRIVIAL_DESTRUCTOR(name, type, func)             \
 581         static inline void name(type *p) {                      \
 582                 func(p);                                        \
 583         }
 584
 585 #define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
 586         static inline void func##p(type *p) {                   \
 587                 if (*p)                                         \
 588                         func(*p);                               \
 589         }
 590
 591 #define _DEFINE_TRIVIAL_REF_FUNC(type, name, scope)             \
 592         scope type *name##_ref(type *p) {                       \
 593                 if (!p)                                         \
 594                         return NULL;                            \
 595                                                                 \
 596                 assert(p->n_ref > 0);                           \
 597                 p->n_ref++;                                     \
 598                 return p;                                       \
 599         }
 600
 601 #define _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, scope) \
 602         scope type *name##_unref(type *p) {                      \
 603                 if (!p)                                          \
 604                         return NULL;                             \
 605                                                                  \
 606                 assert(p->n_ref > 0);                            \
 607                 p->n_ref--;                                      \
 608                 if (p->n_ref > 0)                                \
 609                         return NULL;                             \
 610                                                                  \
 611                 return free_func(p);                             \
 612         }
 613
 614 #define DEFINE_TRIVIAL_REF_FUNC(type, name)     \
 615         _DEFINE_TRIVIAL_REF_FUNC(type, name,)
 616 #define DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name)     \
 617         _DEFINE_TRIVIAL_REF_FUNC(type, name, static)
 618 #define DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name)      \
 619         _DEFINE_TRIVIAL_REF_FUNC(type, name, _public_)
 620
 621 #define DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func)        \
 622         _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func,)
 623 #define DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func)        \
 624         _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, static)
 625 #define DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func)         \
 626         _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, _public_)
 627
 628 #define DEFINE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
 629         DEFINE_TRIVIAL_REF_FUNC(type, name);                    \
 630         DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func);
 631
 632 #define DEFINE_PRIVATE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
 633         DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name);                    \
 634         DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func);
 635
 636 #define DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
 637         DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name);                    \
 638         DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func);
 639
 640 /* A macro to force copying of a variable from memory. This is useful whenever we want to read something from
 641  * memory and want to make sure the compiler won't optimize away the destination variable for us. It's not
 642  * supposed to be a full CPU memory barrier, i.e. CPU is still allowed to reorder the reads, but it is not
 643  * allowed to remove our local copies of the variables. We want this to work for unaligned memory, hence
 644  * memcpy() is great for our purposes. */
 645 #define READ_NOW(x)                                                     \
 646         ({                                                              \
 647                 typeof(x) _copy;                                        \
 648                 memcpy(&_copy, &(x), sizeof(_copy));                    \
 649                 asm volatile ("" : : : "memory");                       \
 650                 _copy;                                                  \
 651         })
 652
 653 static inline size_t size_add(size_t x, size_t y) {
 654         return y >= SIZE_MAX - x ? SIZE_MAX : x + y;
 655 }
 656
 657 #include "log.h"