src/basic/macro.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <assert.h>
   5 #include <inttypes.h>
   6 #include <stdbool.h>
   7 #include <sys/param.h>
   8 #include <sys/sysmacros.h>
   9 #include <sys/types.h>
  10
  11 #define _printf_(a, b) __attribute__ ((__format__(printf, a, b)))
  12 #ifdef __clang__
  13 #  define _alloc_(...)
  14 #else
  15 #  define _alloc_(...) __attribute__ ((__alloc_size__(__VA_ARGS__)))
  16 #endif
  17 #define _sentinel_ __attribute__ ((__sentinel__))
  18 #define _unused_ __attribute__ ((__unused__))
  19 #define _destructor_ __attribute__ ((__destructor__))
  20 #define _pure_ __attribute__ ((__pure__))
  21 #define _const_ __attribute__ ((__const__))
  22 #define _deprecated_ __attribute__ ((__deprecated__))
  23 #define _packed_ __attribute__ ((__packed__))
  24 #define _malloc_ __attribute__ ((__malloc__))
  25 #define _weak_ __attribute__ ((__weak__))
  26 #define _likely_(x) (__builtin_expect(!!(x), 1))
  27 #define _unlikely_(x) (__builtin_expect(!!(x), 0))
  28 #define _public_ __attribute__ ((__visibility__("default")))
  29 #define _hidden_ __attribute__ ((__visibility__("hidden")))
  30 #define _weakref_(x) __attribute__((__weakref__(#x)))
  31 #define _alignas_(x) __attribute__((__aligned__(__alignof(x))))
  32 #define _cleanup_(x) __attribute__((__cleanup__(x)))
  33 #if __GNUC__ >= 7
  34 #define _fallthrough_ __attribute__((__fallthrough__))
  35 #else
  36 #define _fallthrough_
  37 #endif
  38 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
  39  * compiler versions */
  40 #ifndef _noreturn_
  41 #if __STDC_VERSION__ >= 201112L
  42 #define _noreturn_ _Noreturn
  43 #else
  44 #define _noreturn_ __attribute__((__noreturn__))
  45 #endif
  46 #endif
  47
  48 #if !defined(HAS_FEATURE_MEMORY_SANITIZER)
  49 #  if defined(__has_feature)
  50 #    if __has_feature(memory_sanitizer)
  51 #      define HAS_FEATURE_MEMORY_SANITIZER 1
  52 #    endif
  53 #  endif
  54 #  if !defined(HAS_FEATURE_MEMORY_SANITIZER)
  55 #    define HAS_FEATURE_MEMORY_SANITIZER 0
  56 #  endif
  57 #endif
  58
  59 /* Temporarily disable some warnings */
  60 #define DISABLE_WARNING_FORMAT_NONLITERAL                               \
  61         _Pragma("GCC diagnostic push");                                 \
  62         _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
  63
  64 #define DISABLE_WARNING_MISSING_PROTOTYPES                              \
  65         _Pragma("GCC diagnostic push");                                 \
  66         _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
  67
  68 #define DISABLE_WARNING_NONNULL                                         \
  69         _Pragma("GCC diagnostic push");                                 \
  70         _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
  71
  72 #define DISABLE_WARNING_SHADOW                                          \
  73         _Pragma("GCC diagnostic push");                                 \
  74         _Pragma("GCC diagnostic ignored \"-Wshadow\"")
  75
  76 #define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
  77         _Pragma("GCC diagnostic push");                                 \
  78         _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
  79
  80 #define REENABLE_WARNING                                                \
  81         _Pragma("GCC diagnostic pop")
  82
  83 /* automake test harness */
  84 #define EXIT_TEST_SKIP 77
  85
  86 #define XSTRINGIFY(x) #x
  87 #define STRINGIFY(x) XSTRINGIFY(x)
  88
  89 #define XCONCATENATE(x, y) x ## y
  90 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  91
  92 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
  93 #define UNIQ __COUNTER__
  94
  95 /* builtins */
  96 #if __SIZEOF_INT__ == 4
  97 #define BUILTIN_FFS_U32(x) __builtin_ffs(x);
  98 #elif __SIZEOF_LONG__ == 4
  99 #define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
 100 #else
 101 #error "neither int nor long are four bytes long?!?"
 102 #endif
 103
 104 /* Rounds up */
 105
 106 #define ALIGN4(l) (((l) + 3) & ~3)
 107 #define ALIGN8(l) (((l) + 7) & ~7)
 108
 109 #if __SIZEOF_POINTER__ == 8
 110 #define ALIGN(l) ALIGN8(l)
 111 #elif __SIZEOF_POINTER__ == 4
 112 #define ALIGN(l) ALIGN4(l)
 113 #else
 114 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
 115 #endif
 116
 117 #define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
 118 #define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
 119 #define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
 120
 121 static inline size_t ALIGN_TO(size_t l, size_t ali) {
 122         return ((l + ali - 1) & ~(ali - 1));
 123 }
 124
 125 #define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
 126
 127 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
 128 static inline unsigned long ALIGN_POWER2(unsigned long u) {
 129         /* clz(0) is undefined */
 130         if (u == 1)
 131                 return 1;
 132
 133         /* left-shift overflow is undefined */
 134         if (__builtin_clzl(u - 1UL) < 1)
 135                 return 0;
 136
 137         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
 138 }
 139
 140 #ifndef __COVERITY__
 141 #  define VOID_0 ((void)0)
 142 #else
 143 #  define VOID_0 ((void*)0)
 144 #endif
 145
 146 #define ELEMENTSOF(x)                                                   \
 147         (__builtin_choose_expr(                                         \
 148                 !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
 149                 sizeof(x)/sizeof((x)[0]),                               \
 150                 VOID_0))
 151
 152 /*
 153  * STRLEN - return the length of a string literal, minus the trailing NUL byte.
 154  *          Contrary to strlen(), this is a constant expression.
 155  * @x: a string literal.
 156  */
 157 #define STRLEN(x) (sizeof(""x"") - 1)
 158
 159 /*
 160  * container_of - cast a member of a structure out to the containing structure
 161  * @ptr: the pointer to the member.
 162  * @type: the type of the container struct this is embedded in.
 163  * @member: the name of the member within the struct.
 164  */
 165 #define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
 166 #define __container_of(uniq, ptr, type, member)                         \
 167         ({                                                              \
 168                 const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
 169                 (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type, member) ); \
 170         })
 171
 172 #undef MAX
 173 #define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
 174 #define __MAX(aq, a, bq, b)                             \
 175         ({                                              \
 176                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 177                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 178                 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
 179         })
 180
 181 /* evaluates to (void) if _A or _B are not constant or of different types */
 182 #define CONST_MAX(_A, _B) \
 183         (__builtin_choose_expr(                                         \
 184                 __builtin_constant_p(_A) &&                             \
 185                 __builtin_constant_p(_B) &&                             \
 186                 __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
 187                 ((_A) > (_B)) ? (_A) : (_B),                            \
 188                 VOID_0))
 189
 190 /* takes two types and returns the size of the larger one */
 191 #define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
 192
 193 #define MAX3(x, y, z)                                   \
 194         ({                                              \
 195                 const typeof(x) _c = MAX(x, y);         \
 196                 MAX(_c, z);                             \
 197         })
 198
 199 #undef MIN
 200 #define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
 201 #define __MIN(aq, a, bq, b)                             \
 202         ({                                              \
 203                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 204                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 205                 UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
 206         })
 207
 208 #define MIN3(x, y, z)                                   \
 209         ({                                              \
 210                 const typeof(x) _c = MIN(x, y);         \
 211                 MIN(_c, z);                             \
 212         })
 213
 214 #define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
 215 #define __LESS_BY(aq, a, bq, b)                         \
 216         ({                                              \
 217                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 218                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 219                 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
 220         })
 221
 222 #define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
 223 #define __CMP(aq, a, bq, b)                             \
 224         ({                                              \
 225                 const typeof(a) UNIQ_T(A, aq) = (a);    \
 226                 const typeof(b) UNIQ_T(B, bq) = (b);    \
 227                 UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 :    \
 228                 UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0;  \
 229         })
 230
 231 #undef CLAMP
 232 #define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
 233 #define __CLAMP(xq, x, lowq, low, highq, high)                          \
 234         ({                                                              \
 235                 const typeof(x) UNIQ_T(X, xq) = (x);                    \
 236                 const typeof(low) UNIQ_T(LOW, lowq) = (low);            \
 237                 const typeof(high) UNIQ_T(HIGH, highq) = (high);        \
 238                         UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ?           \
 239                                 UNIQ_T(HIGH, highq) :                   \
 240                                 UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ?     \
 241                                         UNIQ_T(LOW, lowq) :             \
 242                                         UNIQ_T(X, xq);                  \
 243         })
 244
 245 /* [(x + y - 1) / y] suffers from an integer overflow, even though the
 246  * computation should be possible in the given type. Therefore, we use
 247  * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
 248  * quotient and the remainder, so both should be equally fast. */
 249 #define DIV_ROUND_UP(x, y) __DIV_ROUND_UP(UNIQ, (x), UNIQ, (y))
 250 #define __DIV_ROUND_UP(xq, x, yq, y)                                    \
 251         ({                                                              \
 252                 const typeof(x) UNIQ_T(X, xq) = (x);                    \
 253                 const typeof(y) UNIQ_T(Y, yq) = (y);                    \
 254                 (UNIQ_T(X, xq) / UNIQ_T(Y, yq) + !!(UNIQ_T(X, xq) % UNIQ_T(Y, yq))); \
 255         })
 256
 257 #ifdef __COVERITY__
 258
 259 /* Use special definitions of assertion macros in order to prevent
 260  * false positives of ASSERT_SIDE_EFFECT on Coverity static analyzer
 261  * for uses of assert_se() and assert_return().
 262  *
 263  * These definitions make expression go through a (trivial) function
 264  * call to ensure they are not discarded. Also use ! or !! to ensure
 265  * the boolean expressions are seen as such.
 266  *
 267  * This technique has been described and recommended in:
 268  * https://community.synopsys.com/s/question/0D534000046Yuzb/suppressing-assertsideeffect-for-functions-that-allow-for-sideeffects
 269  */
 270
 271 extern void __coverity_panic__(void);
 272
 273 static inline int __coverity_check__(int condition) {
 274         return condition;
 275 }
 276
 277 #define assert_message_se(expr, message)                                \
 278         do {                                                            \
 279                 if (__coverity_check__(!(expr)))                        \
 280                         __coverity_panic__();                           \
 281         } while (false)
 282
 283 #define assert_log(expr, message) __coverity_check__(!!(expr))
 284
 285 #else  /* ! __COVERITY__ */
 286
 287 #define assert_message_se(expr, message)                                \
 288         do {                                                            \
 289                 if (_unlikely_(!(expr)))                                \
 290                         log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 291         } while (false)
 292
 293 #define assert_log(expr, message) ((_likely_(expr))                     \
 294         ? (true)                                                        \
 295         : (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
 296
 297 #endif  /* __COVERITY__ */
 298
 299 #define assert_se(expr) assert_message_se(expr, #expr)
 300
 301 /* We override the glibc assert() here. */
 302 #undef assert
 303 #ifdef NDEBUG
 304 #define assert(expr) do {} while (false)
 305 #else
 306 #define assert(expr) assert_message_se(expr, #expr)
 307 #endif
 308
 309 #define assert_not_reached(t)                                           \
 310         do {                                                            \
 311                 log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
 312         } while (false)
 313
 314 #if defined(static_assert)
 315 #define assert_cc(expr)                                                 \
 316         static_assert(expr, #expr);
 317 #else
 318 #define assert_cc(expr)                                                 \
 319         struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
 320                 char x[(expr) ? 0 : -1];                                \
 321         };
 322 #endif
 323
 324 #define assert_return(expr, r)                                          \
 325         do {                                                            \
 326                 if (!assert_log(expr, #expr))                           \
 327                         return (r);                                     \
 328         } while (false)
 329
 330 #define assert_return_errno(expr, r, err)                               \
 331         do {                                                            \
 332                 if (!assert_log(expr, #expr)) {                         \
 333                         errno = err;                                    \
 334                         return (r);                                     \
 335                 }                                                       \
 336         } while (false)
 337
 338 #define return_with_errno(r, err)                     \
 339         do {                                          \
 340                 errno = abs(err);                     \
 341                 return r;                             \
 342         } while (false)
 343
 344 #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
 345 #define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 346 #define PTR_TO_UINT(p) ((unsigned) ((uintptr_t) (p)))
 347 #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 348
 349 #define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
 350 #define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
 351 #define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
 352 #define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 353
 354 #define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
 355 #define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 356 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
 357 #define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 358
 359 #define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
 360 #define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
 361 #define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
 362 #define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 363
 364 #define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
 365 #define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 366
 367 #define CHAR_TO_STR(x) ((char[2]) { x, 0 })
 368
 369 #define char_array_0(x) x[sizeof(x)-1] = 0;
 370
 371 /* Returns the number of chars needed to format variables of the
 372  * specified type as a decimal string. Adds in extra space for a
 373  * negative '-' prefix (hence works correctly on signed
 374  * types). Includes space for the trailing NUL. */
 375 #define DECIMAL_STR_MAX(type)                                           \
 376         (2+(sizeof(type) <= 1 ? 3 :                                     \
 377             sizeof(type) <= 2 ? 5 :                                     \
 378             sizeof(type) <= 4 ? 10 :                                    \
 379             sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
 380
 381 #define DECIMAL_STR_WIDTH(x)                            \
 382         ({                                              \
 383                 typeof(x) _x_ = (x);                    \
 384                 unsigned ans = 1;                       \
 385                 while ((_x_ /= 10) != 0)                \
 386                         ans++;                          \
 387                 ans;                                    \
 388         })
 389
 390 #define SET_FLAG(v, flag, b) \
 391         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 392 #define FLAGS_SET(v, flags) \
 393         ((~(v) & (flags)) == 0)
 394
 395 #define CASE_F(X) case X:
 396 #define CASE_F_1(CASE, X) CASE_F(X)
 397 #define CASE_F_2(CASE, X, ...)  CASE(X) CASE_F_1(CASE, __VA_ARGS__)
 398 #define CASE_F_3(CASE, X, ...)  CASE(X) CASE_F_2(CASE, __VA_ARGS__)
 399 #define CASE_F_4(CASE, X, ...)  CASE(X) CASE_F_3(CASE, __VA_ARGS__)
 400 #define CASE_F_5(CASE, X, ...)  CASE(X) CASE_F_4(CASE, __VA_ARGS__)
 401 #define CASE_F_6(CASE, X, ...)  CASE(X) CASE_F_5(CASE, __VA_ARGS__)
 402 #define CASE_F_7(CASE, X, ...)  CASE(X) CASE_F_6(CASE, __VA_ARGS__)
 403 #define CASE_F_8(CASE, X, ...)  CASE(X) CASE_F_7(CASE, __VA_ARGS__)
 404 #define CASE_F_9(CASE, X, ...)  CASE(X) CASE_F_8(CASE, __VA_ARGS__)
 405 #define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
 406 #define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
 407 #define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
 408 #define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
 409 #define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
 410 #define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
 411 #define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
 412 #define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
 413 #define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
 414 #define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
 415 #define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
 416
 417 #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
 418 #define FOR_EACH_MAKE_CASE(...) \
 419         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, \
 420                                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) \
 421                    (CASE_F,__VA_ARGS__)
 422
 423 #define IN_SET(x, ...)                          \
 424         ({                                      \
 425                 bool _found = false;            \
 426                 /* If the build breaks in the line below, you need to extend the case macros. (We use "long double" as  \
 427                  * type for the array, in the hope that checkers such as ubsan don't complain that the initializers for \
 428                  * the array are not representable by the base type. Ideally we'd use typeof(x) as base type, but that  \
 429                  * doesn't work, as we want to use this on bitfields and gcc refuses typeof() on bitfields.) */         \
 430                 assert_cc((sizeof((long double[]){__VA_ARGS__})/sizeof(long double)) <= 20); \
 431                 switch(x) {                     \
 432                 FOR_EACH_MAKE_CASE(__VA_ARGS__) \
 433                         _found = true;          \
 434                         break;                  \
 435                 default:                        \
 436                         break;                  \
 437                 }                               \
 438                 _found;                         \
 439         })
 440
 441 #define SWAP_TWO(x, y) do {                        \
 442                 typeof(x) _t = (x);                \
 443                 (x) = (y);                         \
 444                 (y) = (_t);                        \
 445         } while (false)
 446
 447 /* Define C11 thread_local attribute even on older gcc compiler
 448  * version */
 449 #ifndef thread_local
 450 /*
 451  * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
 452  * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
 453  */
 454 #if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
 455 #define thread_local _Thread_local
 456 #else
 457 #define thread_local __thread
 458 #endif
 459 #endif
 460
 461 #define DEFINE_TRIVIAL_DESTRUCTOR(name, type, func)             \
 462         static inline void name(type *p) {                      \
 463                 func(p);                                        \
 464         }
 465
 466 #define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
 467         static inline void func##p(type *p) {                   \
 468                 if (*p)                                         \
 469                         func(*p);                               \
 470         }
 471
 472 #define _DEFINE_TRIVIAL_REF_FUNC(type, name, scope)             \
 473         scope type *name##_ref(type *p) {                       \
 474                 if (!p)                                         \
 475                         return NULL;                            \
 476                                                                 \
 477                 assert(p->n_ref > 0);                           \
 478                 p->n_ref++;                                     \
 479                 return p;                                       \
 480         }
 481
 482 #define _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, scope) \
 483         scope type *name##_unref(type *p) {                      \
 484                 if (!p)                                          \
 485                         return NULL;                             \
 486                                                                  \
 487                 assert(p->n_ref > 0);                            \
 488                 p->n_ref--;                                      \
 489                 if (p->n_ref > 0)                                \
 490                         return NULL;                             \
 491                                                                  \
 492                 return free_func(p);                             \
 493         }
 494
 495 #define DEFINE_TRIVIAL_REF_FUNC(type, name)     \
 496         _DEFINE_TRIVIAL_REF_FUNC(type, name,)
 497 #define DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name)     \
 498         _DEFINE_TRIVIAL_REF_FUNC(type, name, static)
 499 #define DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name)      \
 500         _DEFINE_TRIVIAL_REF_FUNC(type, name, _public_)
 501
 502 #define DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func)        \
 503         _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func,)
 504 #define DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func)        \
 505         _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, static)
 506 #define DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func)         \
 507         _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, _public_)
 508
 509 #define DEFINE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
 510         DEFINE_TRIVIAL_REF_FUNC(type, name);                    \
 511         DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func);
 512
 513 #define DEFINE_PRIVATE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
 514         DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name);                    \
 515         DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func);
 516
 517 #define DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
 518         DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name);                    \
 519         DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func);
 520
 521 #include "log.h"