Systemd/src/basic/macro.h
Lennart Poettering 8e2b687957 macro: rework IN_SET a bit
This makes use of assert_cc() to guard against missing CASE macros,
instead of a manual implementation that might result in a static
variable to be allocated.

More importantly though this changes the base type for the array used to
determine the number of arguments for the compile time check from "int"
to "long double". This is done in order to avoid warnings from "ubsan"
that possibly large constants are assigned to small types. "long double"
hopefully isn't vulnerable to that.

Fixes: #10332
2018-10-11 22:07:14 +02:00

509 lines
22 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <inttypes.h>
#include <stdbool.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#define _printf_(a, b) __attribute__ ((format (printf, a, b)))
#ifdef __clang__
# define _alloc_(...)
#else
# define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
#endif
#define _sentinel_ __attribute__ ((sentinel))
#define _unused_ __attribute__ ((unused))
#define _destructor_ __attribute__ ((destructor))
#define _pure_ __attribute__ ((pure))
#define _const_ __attribute__ ((const))
#define _deprecated_ __attribute__ ((deprecated))
#define _packed_ __attribute__ ((packed))
#define _malloc_ __attribute__ ((malloc))
#define _weak_ __attribute__ ((weak))
#define _likely_(x) (__builtin_expect(!!(x), 1))
#define _unlikely_(x) (__builtin_expect(!!(x), 0))
#define _public_ __attribute__ ((visibility("default")))
#define _hidden_ __attribute__ ((visibility("hidden")))
#define _weakref_(x) __attribute__((weakref(#x)))
#define _alignas_(x) __attribute__((aligned(__alignof(x))))
#define _cleanup_(x) __attribute__((cleanup(x)))
#if __GNUC__ >= 7
#define _fallthrough_ __attribute__((fallthrough))
#else
#define _fallthrough_
#endif
/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
* compiler versions */
#ifndef _noreturn_
#if __STDC_VERSION__ >= 201112L
#define _noreturn_ _Noreturn
#else
#define _noreturn_ __attribute__((noreturn))
#endif
#endif
#if !defined(HAS_FEATURE_MEMORY_SANITIZER)
# if defined(__has_feature)
# if __has_feature(memory_sanitizer)
# define HAS_FEATURE_MEMORY_SANITIZER 1
# endif
# endif
# if !defined(HAS_FEATURE_MEMORY_SANITIZER)
# define HAS_FEATURE_MEMORY_SANITIZER 0
# endif
#endif
/* Temporarily disable some warnings */
#define DISABLE_WARNING_FORMAT_NONLITERAL \
_Pragma("GCC diagnostic push"); \
_Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
#define DISABLE_WARNING_MISSING_PROTOTYPES \
_Pragma("GCC diagnostic push"); \
_Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
#define DISABLE_WARNING_NONNULL \
_Pragma("GCC diagnostic push"); \
_Pragma("GCC diagnostic ignored \"-Wnonnull\"")
#define DISABLE_WARNING_SHADOW \
_Pragma("GCC diagnostic push"); \
_Pragma("GCC diagnostic ignored \"-Wshadow\"")
#define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES \
_Pragma("GCC diagnostic push"); \
_Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
#define REENABLE_WARNING \
_Pragma("GCC diagnostic pop")
/* automake test harness */
#define EXIT_TEST_SKIP 77
#define XSTRINGIFY(x) #x
#define STRINGIFY(x) XSTRINGIFY(x)
#define XCONCATENATE(x, y) x ## y
#define CONCATENATE(x, y) XCONCATENATE(x, y)
#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
#define UNIQ __COUNTER__
/* builtins */
#if __SIZEOF_INT__ == 4
#define BUILTIN_FFS_U32(x) __builtin_ffs(x);
#elif __SIZEOF_LONG__ == 4
#define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
#else
#error "neither int nor long are four bytes long?!?"
#endif
/* Rounds up */
#define ALIGN4(l) (((l) + 3) & ~3)
#define ALIGN8(l) (((l) + 7) & ~7)
#if __SIZEOF_POINTER__ == 8
#define ALIGN(l) ALIGN8(l)
#elif __SIZEOF_POINTER__ == 4
#define ALIGN(l) ALIGN4(l)
#else
#error "Wut? Pointers are neither 4 nor 8 bytes long?"
#endif
#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
static inline size_t ALIGN_TO(size_t l, size_t ali) {
return ((l + ali - 1) & ~(ali - 1));
}
#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
/* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
static inline unsigned long ALIGN_POWER2(unsigned long u) {
/* clz(0) is undefined */
if (u == 1)
return 1;
/* left-shift overflow is undefined */
if (__builtin_clzl(u - 1UL) < 1)
return 0;
return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
}
#ifndef __COVERITY__
# define VOID_0 ((void)0)
#else
# define VOID_0 ((void*)0)
#endif
#define ELEMENTSOF(x) \
(__builtin_choose_expr( \
!__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
sizeof(x)/sizeof((x)[0]), \
VOID_0))
/*
* STRLEN - return the length of a string literal, minus the trailing NUL byte.
* Contrary to strlen(), this is a constant expression.
* @x: a string literal.
*/
#define STRLEN(x) (sizeof(""x"") - 1)
/*
* container_of - cast a member of a structure out to the containing structure
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*/
#define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
#define __container_of(uniq, ptr, type, member) \
({ \
const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
(type*)( (char *)UNIQ_T(A, uniq) - offsetof(type, member) ); \
})
#undef MAX
#define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
#define __MAX(aq, a, bq, b) \
({ \
const typeof(a) UNIQ_T(A, aq) = (a); \
const typeof(b) UNIQ_T(B, bq) = (b); \
UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
})
/* evaluates to (void) if _A or _B are not constant or of different types */
#define CONST_MAX(_A, _B) \
(__builtin_choose_expr( \
__builtin_constant_p(_A) && \
__builtin_constant_p(_B) && \
__builtin_types_compatible_p(typeof(_A), typeof(_B)), \
((_A) > (_B)) ? (_A) : (_B), \
VOID_0))
/* takes two types and returns the size of the larger one */
#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
#define MAX3(x, y, z) \
({ \
const typeof(x) _c = MAX(x, y); \
MAX(_c, z); \
})
#undef MIN
#define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
#define __MIN(aq, a, bq, b) \
({ \
const typeof(a) UNIQ_T(A, aq) = (a); \
const typeof(b) UNIQ_T(B, bq) = (b); \
UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
})
#define MIN3(x, y, z) \
({ \
const typeof(x) _c = MIN(x, y); \
MIN(_c, z); \
})
#define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
#define __LESS_BY(aq, a, bq, b) \
({ \
const typeof(a) UNIQ_T(A, aq) = (a); \
const typeof(b) UNIQ_T(B, bq) = (b); \
UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
})
#define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
#define __CMP(aq, a, bq, b) \
({ \
const typeof(a) UNIQ_T(A, aq) = (a); \
const typeof(b) UNIQ_T(B, bq) = (b); \
UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 : \
UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0; \
})
#undef CLAMP
#define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
#define __CLAMP(xq, x, lowq, low, highq, high) \
({ \
const typeof(x) UNIQ_T(X, xq) = (x); \
const typeof(low) UNIQ_T(LOW, lowq) = (low); \
const typeof(high) UNIQ_T(HIGH, highq) = (high); \
UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ? \
UNIQ_T(HIGH, highq) : \
UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ? \
UNIQ_T(LOW, lowq) : \
UNIQ_T(X, xq); \
})
/* [(x + y - 1) / y] suffers from an integer overflow, even though the
* computation should be possible in the given type. Therefore, we use
* [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
* quotient and the remainder, so both should be equally fast. */
#define DIV_ROUND_UP(_x, _y) \
({ \
const typeof(_x) __x = (_x); \
const typeof(_y) __y = (_y); \
(__x / __y + !!(__x % __y)); \
})
#ifdef __COVERITY__
/* Use special definitions of assertion macros in order to prevent
* false positives of ASSERT_SIDE_EFFECT on Coverity static analyzer
* for uses of assert_se() and assert_return().
*
* These definitions make expression go through a (trivial) function
* call to ensure they are not discarded. Also use ! or !! to ensure
* the boolean expressions are seen as such.
*
* This technique has been described and recommended in:
* https://community.synopsys.com/s/question/0D534000046Yuzb/suppressing-assertsideeffect-for-functions-that-allow-for-sideeffects
*/
extern void __coverity_panic__(void);
static inline int __coverity_check__(int condition) {
return condition;
}
#define assert_message_se(expr, message) \
do { \
if (__coverity_check__(!(expr))) \
__coverity_panic__(); \
} while (false)
#define assert_log(expr, message) __coverity_check__(!!(expr))
#else /* ! __COVERITY__ */
#define assert_message_se(expr, message) \
do { \
if (_unlikely_(!(expr))) \
log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
} while (false)
#define assert_log(expr, message) ((_likely_(expr)) \
? (true) \
: (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
#endif /* __COVERITY__ */
#define assert_se(expr) assert_message_se(expr, #expr)
/* We override the glibc assert() here. */
#undef assert
#ifdef NDEBUG
#define assert(expr) do {} while (false)
#else
#define assert(expr) assert_message_se(expr, #expr)
#endif
#define assert_not_reached(t) \
do { \
log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
} while (false)
#if defined(static_assert)
#define assert_cc(expr) \
static_assert(expr, #expr);
#else
#define assert_cc(expr) \
struct CONCATENATE(_assert_struct_, __COUNTER__) { \
char x[(expr) ? 0 : -1]; \
};
#endif
#define assert_return(expr, r) \
do { \
if (!assert_log(expr, #expr)) \
return (r); \
} while (false)
#define assert_return_errno(expr, r, err) \
do { \
if (!assert_log(expr, #expr)) { \
errno = err; \
return (r); \
} \
} while (false)
#define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
#define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
#define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
#define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
#define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
#define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
#define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
#define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
#define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
#define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define CHAR_TO_STR(x) ((char[2]) { x, 0 })
#define char_array_0(x) x[sizeof(x)-1] = 0;
/* Returns the number of chars needed to format variables of the
* specified type as a decimal string. Adds in extra space for a
* negative '-' prefix (hence works correctly on signed
* types). Includes space for the trailing NUL. */
#define DECIMAL_STR_MAX(type) \
(2+(sizeof(type) <= 1 ? 3 : \
sizeof(type) <= 2 ? 5 : \
sizeof(type) <= 4 ? 10 : \
sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
#define DECIMAL_STR_WIDTH(x) \
({ \
typeof(x) _x_ = (x); \
unsigned ans = 1; \
while ((_x_ /= 10) != 0) \
ans++; \
ans; \
})
#define SET_FLAG(v, flag, b) \
(v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
#define FLAGS_SET(v, flags) \
(((v) & (flags)) == (flags))
#define CASE_F(X) case X:
#define CASE_F_1(CASE, X) CASE_F(X)
#define CASE_F_2(CASE, X, ...) CASE(X) CASE_F_1(CASE, __VA_ARGS__)
#define CASE_F_3(CASE, X, ...) CASE(X) CASE_F_2(CASE, __VA_ARGS__)
#define CASE_F_4(CASE, X, ...) CASE(X) CASE_F_3(CASE, __VA_ARGS__)
#define CASE_F_5(CASE, X, ...) CASE(X) CASE_F_4(CASE, __VA_ARGS__)
#define CASE_F_6(CASE, X, ...) CASE(X) CASE_F_5(CASE, __VA_ARGS__)
#define CASE_F_7(CASE, X, ...) CASE(X) CASE_F_6(CASE, __VA_ARGS__)
#define CASE_F_8(CASE, X, ...) CASE(X) CASE_F_7(CASE, __VA_ARGS__)
#define CASE_F_9(CASE, X, ...) CASE(X) CASE_F_8(CASE, __VA_ARGS__)
#define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
#define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
#define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
#define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
#define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
#define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
#define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
#define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
#define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
#define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
#define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
#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
#define FOR_EACH_MAKE_CASE(...) \
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, \
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) \
(CASE_F,__VA_ARGS__)
#define IN_SET(x, ...) \
({ \
bool _found = false; \
/* If the build breaks in the line below, you need to extend the case macros. (We use "long double" as \
* type for the array, in the hope that checkers such as ubsan don't complain that the initializers for \
* the array are not representable by the base type. Ideally we'd use typeof(x) as base type, but that \
* doesn't work, as we want to use this on bitfields and gcc refuses typeof() on bitfields.) */ \
assert_cc((sizeof((long double[]){__VA_ARGS__})/sizeof(long double)) <= 20); \
switch(x) { \
FOR_EACH_MAKE_CASE(__VA_ARGS__) \
_found = true; \
break; \
default: \
break; \
} \
_found; \
})
#define SWAP_TWO(x, y) do { \
typeof(x) _t = (x); \
(x) = (y); \
(y) = (_t); \
} while (false)
/* Define C11 thread_local attribute even on older gcc compiler
* version */
#ifndef thread_local
/*
* Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
* see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
*/
#if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
#define thread_local _Thread_local
#else
#define thread_local __thread
#endif
#endif
#define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func) \
static inline void func##p(type *p) { \
if (*p) \
func(*p); \
}
#define _DEFINE_TRIVIAL_REF_FUNC(type, name, scope) \
scope type *name##_ref(type *p) { \
if (!p) \
return NULL; \
\
assert(p->n_ref > 0); \
p->n_ref++; \
return p; \
}
#define _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, scope) \
scope type *name##_unref(type *p) { \
if (!p) \
return NULL; \
\
assert(p->n_ref > 0); \
p->n_ref--; \
if (p->n_ref > 0) \
return NULL; \
\
return free_func(p); \
}
#define DEFINE_TRIVIAL_REF_FUNC(type, name) \
_DEFINE_TRIVIAL_REF_FUNC(type, name,)
#define DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name) \
_DEFINE_TRIVIAL_REF_FUNC(type, name, static)
#define DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name) \
_DEFINE_TRIVIAL_REF_FUNC(type, name, _public_)
#define DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func) \
_DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func,)
#define DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func) \
_DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, static)
#define DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func) \
_DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, _public_)
#define DEFINE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func) \
DEFINE_TRIVIAL_REF_FUNC(type, name); \
DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func);
#define DEFINE_PRIVATE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func) \
DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name); \
DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func);
#define DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(type, name, free_func) \
DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name); \
DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func);
#include "log.h"