Files
systemd/src/basic/macro.h
T
Lennart Poettering 026c2677fc macro: add macro for llvm no_sanitize_address attribute
We want it for global variables, which LLVM supports and GCC currently
does not (GCC does support it for functions, but we care about global
variables here).

Why is this relevant? When asan is used global variables are padded with
hotzones before and after. But we can't have that for the registration
variables we place in special ELF sections: we want them tightly packed
so that we can iterate through them.

Note that for gcc this isn't an issue, as it will pack stuff in
non-standard sections anyway, even if asan is used.
2018-12-03 17:35:50 +01:00

544 lines
23 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <assert.h>
#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 _section_(x) __attribute__((__section__(x)))
#define _used_ __attribute__((__used__))
#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 _align_(x) __attribute__((__aligned__(x)))
#define _alignas_(x) __attribute__((__aligned__(__alignof(x))))
#define _alignptr_ __attribute__((__aligned__(sizeof(void*))))
#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
#if !defined(HAS_FEATURE_ADDRESS_SANITIZER)
# ifdef __SANITIZE_ADDRESS__
# define HAS_FEATURE_ADDRESS_SANITIZER 1
# elif defined(__has_feature)
# if __has_feature(address_sanitizer)
# define HAS_FEATURE_ADDRESS_SANITIZER 1
# endif
# endif
# if !defined(HAS_FEATURE_ADDRESS_SANITIZER)
# define HAS_FEATURE_ADDRESS_SANITIZER 0
# endif
#endif
/* Note: on GCC "no_sanitize_address" is a function attribute only, on llvm it may also be applied to global
* variables. We define a specific macro which knows this. Note that on GCC we don't need this decorator so much, since
* our primary usecase for this attribute is registration structures placed in named ELF sections which shall not be
* padded, but GCC doesn't pad those anyway if AddressSanitizer is enabled. */
#if HAS_FEATURE_ADDRESS_SANITIZER && defined(__clang__)
#define _variable_no_sanitize_address_ __attribute__((__no_sanitize_address__))
#else
#define _variable_no_sanitize_address_
#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) __DIV_ROUND_UP(UNIQ, (x), UNIQ, (y))
#define __DIV_ROUND_UP(xq, x, yq, y) \
({ \
const typeof(x) UNIQ_T(X, xq) = (x); \
const typeof(y) UNIQ_T(Y, yq) = (y); \
(UNIQ_T(X, xq) / UNIQ_T(Y, yq) + !!(UNIQ_T(X, xq) % UNIQ_T(Y, yq))); \
})
#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 return_with_errno(r, err) \
do { \
errno = abs(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) ((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)) == 0)
#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"