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Diffstat (limited to 'src/lib/macros.h')
| -rw-r--r-- | src/lib/macros.h | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/src/lib/macros.h b/src/lib/macros.h new file mode 100644 index 0000000..8cd159f --- /dev/null +++ b/src/lib/macros.h @@ -0,0 +1,302 @@ +#ifndef MACROS_H +#define MACROS_H + +/* several useful macros, mostly from glib.h */ + +#ifndef NULL +# define NULL ((void *)0) +#endif + +#ifndef FALSE +# define FALSE (!1) +#endif + +#ifndef TRUE +# define TRUE (!FALSE) +#endif + +#define N_ELEMENTS(arr) \ + (sizeof(arr) / sizeof((arr)[0])) + +#define MEM_ALIGN(size) \ + (((size) + MEM_ALIGN_SIZE-1) & ~((size_t) MEM_ALIGN_SIZE-1)) + +#define PTR_OFFSET(ptr, offset) \ + ((void *) (((uintptr_t) (ptr)) + ((size_t) (offset)))) +#define CONST_PTR_OFFSET(ptr, offset) \ + ((const void *) (((uintptr_t) (ptr)) + ((size_t) (offset)))) + +#define container_of(ptr, type, name) \ + (type *)((char *)(ptr) - offsetof(type, name) + \ + COMPILE_ERROR_IF_TYPES_NOT_COMPATIBLE(ptr, &((type *) 0)->name)) + +/* Don't use simply MIN/MAX, as they're often defined elsewhere in include + files that are included after this file generating tons of warnings. */ +#define I_MIN(a, b) (((a) < (b)) ? (a) : (b)) +#define I_MAX(a, b) (((a) > (b)) ? (a) : (b)) + +/* make it easier to cast from/to pointers. assumes that + sizeof(uintptr_t) == sizeof(void *) and they're both the largest datatypes + that are allowed to be used. so, long long isn't safe with these. */ +#define POINTER_CAST(i) \ + ((void *) (((uintptr_t)NULL) + (i))) +#define POINTER_CAST_TO(p, type) \ + ((type)(uintptr_t)(p)) + +/* Define VA_COPY() to do the right thing for copying va_list variables. + config.h may have already defined VA_COPY as va_copy or __va_copy. */ +#ifndef VA_COPY +# if defined (__GNUC__) && defined (__PPC__) && \ + (defined (_CALL_SYSV) || defined (_WIN32)) +# define VA_COPY(ap1, ap2) (*(ap1) = *(ap2)) +# elif defined (VA_COPY_AS_ARRAY) +# define VA_COPY(ap1, ap2) memmove ((ap1), (ap2), sizeof (va_list)) +# else /* va_list is a pointer */ +# define VA_COPY(ap1, ap2) ((ap1) = (ap2)) +# endif /* va_list is a pointer */ +#endif + +/* Provide convenience macros for handling structure + * fields through their offsets. + */ +#define STRUCT_MEMBER_P(struct_p, struct_offset) \ + ((void *) ((char *) (struct_p) + (long) (struct_offset))) +#define CONST_STRUCT_MEMBER_P(struct_p, struct_offset) \ + ((const void *) ((const char *) (struct_p) + (long) (struct_offset))) + +/* Provide simple macro statement wrappers: + STMT_START { statements; } STMT_END; + can be used as a single statement, as in + if (x) STMT_START { ... } STMT_END; else ... */ +#if !(defined (STMT_START) && defined (STMT_END)) +# define STMT_START do +# define STMT_END while (0) +#endif + +/* Provide macros to feature the GCC function attribute. */ +#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4) +# define ATTRS_DEFINED +# define ATTR_FORMAT(format_idx, arg_idx) \ + __attribute__((format (printf, format_idx, arg_idx))) +# define ATTR_FORMAT_ARG(arg_idx) \ + __attribute__((format_arg (arg_idx))) +# define ATTR_SCANF(format_idx, arg_idx) \ + __attribute__((format (scanf, format_idx, arg_idx))) +# define ATTR_STRFTIME(format_idx) \ + __attribute__((format (strftime, format_idx, 0))) +# define ATTR_UNUSED __attribute__((unused)) +# define ATTR_NORETURN __attribute__((noreturn)) +# define ATTR_CONST __attribute__((const)) +# define ATTR_PURE __attribute__((pure)) +#else +# define ATTR_FORMAT(format_idx, arg_idx) +# define ATTR_FORMAT_ARG(arg_idx) +# define ATTR_SCANF(format_idx, arg_idx) +# define ATTR_STRFTIME(format_idx) +# define ATTR_UNUSED +# define ATTR_NORETURN +# define ATTR_CONST +# define ATTR_PURE +#endif +#ifdef HAVE_ATTR_NULL +# define ATTR_NULL(...) __attribute__((null(__VA_ARGS__))) +#else +# define ATTR_NULL(...) +#endif +#ifdef HAVE_ATTR_NOWARN_UNUSED_RESULT +# define ATTR_NOWARN_UNUSED_RESULT __attribute__((nowarn_unused_result)) +#else +# define ATTR_NOWARN_UNUSED_RESULT +#endif +#if __GNUC__ > 2 +# define ATTR_MALLOC __attribute__((malloc)) +#else +# define ATTR_MALLOC +#endif +#if __GNUC__ > 3 +/* GCC 4.0 and later */ +# define ATTR_WARN_UNUSED_RESULT __attribute__((warn_unused_result)) +# define ATTR_SENTINEL __attribute__((sentinel)) +#else +# define ATTR_WARN_UNUSED_RESULT +# define ATTR_SENTINEL +#endif +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) +/* GCC 4.3 and later */ +# define ATTR_HOT __attribute__((hot)) +# define ATTR_COLD __attribute__((cold)) +#else +# define ATTR_HOT +# define ATTR_COLD +#endif +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9) +/* GCC 4.9 and later */ +# define ATTR_RETURNS_NONNULL __attribute__((returns_nonnull)) +#else +# define ATTR_RETURNS_NONNULL +#endif +#ifdef HAVE_ATTR_DEPRECATED +# define ATTR_DEPRECATED(str) __attribute__((deprecated(str))) +#else +# define ATTR_DEPRECATED(str) +#endif + +/* Macros to provide type safety for callback functions' context parameters. + This is used like: + + // safe-api.h file: + typedef void safe_callback_t(struct foo *foo); + + void safe_run(safe_callback_t *callback, void *context); + #define safe_run((safe_callback_t *)callback, \ + TRUE ? context : CALLBACK_TYPECHECK(callback, void (*)(typeof(context)))) + + // safe-api.c file: + #undef safe_run + void safe_run(safe_callback_t *callback, void *context) + { + callback(context); + } + + // in caller code: + static void callback(struct foo *foo); + struct foo *foo = ...; + safe_run(callback, foo); + + The first step is to create the callback function in a normal way. Type + safety is added to it by creating a macro that overrides the function and + checks the callback type safety using CALLBACK_TYPECHECK(). + + The CALLBACK_TYPECHECK() macro works by giving a compiling failure if the + provided callback function isn't compatible with the specified function + type parameter. The function type parameter must use typeof(context) in + place of the "void *context" parameter, but otherwise use exactly the same + function type as what the callback is. The macro then casts the given + callback function into the type with "void *context". +*/ +#ifdef HAVE_TYPE_CHECKS +# define CALLBACK_TYPECHECK(callback, type) \ + (COMPILE_ERROR_IF_TRUE(!__builtin_types_compatible_p( \ + typeof(&callback), type)) ? 1 : 0) +#else +# define CALLBACK_TYPECHECK(callback, type) 0 +#endif + +#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 0)) && \ + !defined(__cplusplus) && !defined(STATIC_CHECKER) +# define COMPILE_ERROR_IF_TRUE(condition) \ + (sizeof(char[1 - 2 * ((condition) ? 1 : 0)]) > 0 ? FALSE : FALSE) +#else +# define COMPILE_ERROR_IF_TRUE(condition) FALSE +#endif + +#ifdef HAVE_TYPE_CHECKS +# define COMPILE_ERROR_IF_TYPES_NOT_COMPATIBLE(_a, _b) \ + COMPILE_ERROR_IF_TRUE( \ + !__builtin_types_compatible_p(typeof(_a), typeof(_b))) +#define COMPILE_ERROR_IF_TYPES2_NOT_COMPATIBLE(_a1, _a2, _b) \ + COMPILE_ERROR_IF_TRUE( \ + !__builtin_types_compatible_p(typeof(_a1), typeof(_b)) && \ + !__builtin_types_compatible_p(typeof(_a2), typeof(_b))) +# define TYPE_CHECKS(return_type, checks, func) \ + (FALSE ? (return_type)(checks) : (func)) +#else +# define COMPILE_ERROR_IF_TYPES_NOT_COMPATIBLE(_a, _b) 0 +# define COMPILE_ERROR_IF_TYPES2_NOT_COMPATIBLE(_a1, _a2, _b) 0 +# define TYPE_CHECKS(return_type, checks, func) (func) +#endif + +#if __GNUC__ > 2 +# define unlikely(expr) (__builtin_expect((expr) ? 1 : 0, 0) != 0) +# define likely(expr) (__builtin_expect((expr) ? 1 : 0, 1) != 0) +#else +# define unlikely(expr) expr +# define likely(expr) expr +#endif + +#if defined(__clang__) && ((__clang_major__ > 4) || (__clang_major__ == 3 && __clang_minor__ >= 9)) +# define ATTR_UNSIGNED_WRAPS __attribute__((no_sanitize("integer"))) +#else +# define ATTR_UNSIGNED_WRAPS +#endif + +/* Provide macros for error handling. */ +#ifdef DISABLE_ASSERTS +# define i_assert(expr) +#else +# define i_assert(expr) STMT_START{ \ + if (unlikely(!(expr))) \ + i_panic("file %s: line %d (%s): assertion failed: (%s)", \ + __FILE__, \ + __LINE__, \ + __func__, \ + #expr); }STMT_END +#endif + +/* Convenience macro to test the versions of dovecot. */ +#define DOVECOT_PREREQ(maj, min, micro) \ + ((DOVECOT_VERSION_MAJOR << 24) + \ + (DOVECOT_VERSION_MINOR << 16) + \ + DOVECOT_VERSION_MICRO >= ((maj) << 24) + ((min) << 16) + (micro)) + +#ifdef __cplusplus +# undef STATIC_ARRAY +# define STATIC_ARRAY +#endif + +/* Convenience wrappers for initializing a struct with zeros, although it can + be used for replacing other memset()s also. + + // NOTE: This is the correct way to zero the whole array + char arr[5]; i_zero(&arr); + // This will give compiler error (or zero only the first element): + char arr[5]; i_zero(arr); +*/ +#define i_zero(p) \ + memset(p, 0 + COMPILE_ERROR_IF_TRUE(sizeof(p) > sizeof(void *)), sizeof(*(p))) +#define i_zero_safe(p) \ + safe_memset(p, 0 + COMPILE_ERROR_IF_TRUE(sizeof(p) > sizeof(void *)), sizeof(*(p))) + +#define ST_CHANGED(st_a, st_b) \ + ((st_a).st_mtime != (st_b).st_mtime || \ + ST_MTIME_NSEC(st_a) != ST_MTIME_NSEC(st_b) || \ + (st_a).st_size != (st_b).st_size || \ + (st_a).st_ino != (st_b).st_ino) + +#ifdef HAVE_UNDEFINED_SANITIZER +# define ATTR_NO_SANITIZE(x) __attribute__((no_sanitize((x)))) +#else +# define ATTR_NO_SANITIZE(x) +#endif + +/* gcc and clang do this differently, see + https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gcc/Common-Function-Attributes.html */ +#ifdef HAVE_FSANITIZE_UNDEFINED +# ifdef __clang__ +# define ATTR_NO_SANITIZE_UNDEFINED ATTR_NO_SANITIZE("undefined") +# else +# define ATTR_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize_undefined)) +# endif +#else +# define ATTR_NO_SANITIZE_UNDEFINED +#endif + +#ifdef HAVE_FSANITIZE_INTEGER +# define ATTR_NO_SANITIZE_INTEGER ATTR_NO_SANITIZE("integer") +# define ATTR_NO_SANITIZE_IMPLICIT_CONVERSION ATTR_NO_SANITIZE("implicit-conversion") +#else +# define ATTR_NO_SANITIZE_INTEGER +# define ATTR_NO_SANITIZE_IMPLICIT_CONVERSION +#endif + +/* negate enumeration flags in a way that avoids implicit conversion */ +#ifndef STATIC_CHECKER +# define ENUM_NEGATE(x) \ + ((unsigned int)(~(x)) + COMPILE_ERROR_IF_TRUE(sizeof((x)) > sizeof(int) || (x) < 0 || (x) > INT_MAX)) +#else +/* clang scan-build keeps complaining about x > 2147483647 case, so disable the + sizeof check. */ +# define ENUM_NEGATE(x) ((unsigned int)(~(x))) +#endif + +#endif |