[thirdparty/systemd.git] / src / fundamental / macro-fundamental.h

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once

#if !SD_BOOT
#  include <assert.h>
#endif

#include <limits.h>
#include <stdalign.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

#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)))
#define _const_ __attribute__((__const__))
#define _deprecated_ __attribute__((__deprecated__))
#define _destructor_ __attribute__((__destructor__))
#define _hidden_ __attribute__((__visibility__("hidden")))
#define _likely_(x) (__builtin_expect(!!(x), 1))
#define _malloc_ __attribute__((__malloc__))
#define _noinline_ __attribute__((noinline))
#define _noreturn_ _Noreturn
#define _packed_ __attribute__((__packed__))
#define _printf_(a, b) __attribute__((__format__(printf, a, b)))
#define _public_ __attribute__((__visibility__("default")))
#define _pure_ __attribute__((__pure__))
#define _retain_ __attribute__((__retain__))
#define _returns_nonnull_ __attribute__((__returns_nonnull__))
#define _section_(x) __attribute__((__section__(x)))
#define _sentinel_ __attribute__((__sentinel__))
#define _unlikely_(x) (__builtin_expect(!!(x), 0))
#define _unused_ __attribute__((__unused__))
#define _used_ __attribute__((__used__))
#define _warn_unused_result_ __attribute__((__warn_unused_result__))
#define _weak_ __attribute__((__weak__))
#define _weakref_(x) __attribute__((__weakref__(#x)))

#ifdef __clang__
#  define _alloc_(...)
#else
#  define _alloc_(...) __attribute__((__alloc_size__(__VA_ARGS__)))
#endif

#if __GNUC__ >= 7 || (defined(__clang__) && __clang_major__ >= 10)
#  define _fallthrough_ __attribute__((__fallthrough__))
#else
#  define _fallthrough_
#endif

#define XSTRINGIFY(x) #x
#define STRINGIFY(x) XSTRINGIFY(x)

#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))

#define XCONCATENATE(x, y) x ## y
#define CONCATENATE(x, y) XCONCATENATE(x, y)

#if SD_BOOT
        _noreturn_ void efi_assert(const char *expr, const char *file, unsigned line, const char *function);

        #ifdef NDEBUG
                #define assert(expr)
                #define assert_not_reached() __builtin_unreachable()
        #else
                #define assert(expr) ({ _likely_(expr) ? VOID_0 : efi_assert(#expr, __FILE__, __LINE__, __func__); })
                #define assert_not_reached() efi_assert("Code should not be reached", __FILE__, __LINE__, __func__)
        #endif
        #define static_assert _Static_assert
        #define assert_se(expr) ({ _likely_(expr) ? VOID_0 : efi_assert(#expr, __FILE__, __LINE__, __func__); })
#endif

/* This passes the argument through after (if asserts are enabled) checking that it is not null. */
#define ASSERT_PTR(expr) _ASSERT_PTR(expr, UNIQ_T(_expr_, UNIQ), assert)
#define ASSERT_SE_PTR(expr) _ASSERT_PTR(expr, UNIQ_T(_expr_, UNIQ), assert_se)
#define _ASSERT_PTR(expr, var, check)      \
        ({                                 \
                typeof(expr) var = (expr); \
                check(var);                \
                var;                       \
        })

#define ASSERT_NONNEG(expr)                              \
        ({                                               \
                typeof(expr) _expr_ = (expr), _zero = 0; \
                assert(_expr_ >= _zero);                 \
                _expr_;                                  \
        })

#define ASSERT_SE_NONNEG(expr)                           \
        ({                                               \
                typeof(expr) _expr_ = (expr), _zero = 0; \
                assert_se(_expr_ >= _zero);              \
                _expr_;                                  \
        })

#define assert_cc(expr) static_assert(expr, #expr)

#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
#define UNIQ __COUNTER__

/* Note that this works differently from pthread_once(): this macro does
 * not synchronize code execution, i.e. code that is run conditionalized
 * on this macro will run concurrently to all other code conditionalized
 * the same way, there's no ordering or completion enforced. */
#define ONCE __ONCE(UNIQ_T(_once_, UNIQ))
#define __ONCE(o)                                                  \
        ({                                                         \
                static bool (o) = false;                           \
                __atomic_exchange_n(&(o), true, __ATOMIC_SEQ_CST); \
        })

#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); \
        })

#define IS_UNSIGNED_INTEGER_TYPE(type) \
        (__builtin_types_compatible_p(typeof(type), unsigned char) ||   \
         __builtin_types_compatible_p(typeof(type), unsigned short) ||  \
         __builtin_types_compatible_p(typeof(type), unsigned) ||        \
         __builtin_types_compatible_p(typeof(type), unsigned long) ||   \
         __builtin_types_compatible_p(typeof(type), unsigned long long))

#define IS_SIGNED_INTEGER_TYPE(type) \
        (__builtin_types_compatible_p(typeof(type), signed char) ||   \
         __builtin_types_compatible_p(typeof(type), signed short) ||  \
         __builtin_types_compatible_p(typeof(type), signed) ||        \
         __builtin_types_compatible_p(typeof(type), signed long) ||   \
         __builtin_types_compatible_p(typeof(type), signed long long))

/* Evaluates to (void) if _A or _B are not constant or of different types (being integers of different sizes
 * is also OK as long as the signedness matches) */
#define CONST_MAX(_A, _B) \
        (__builtin_choose_expr(                                         \
                __builtin_constant_p(_A) &&                             \
                __builtin_constant_p(_B) &&                             \
                (__builtin_types_compatible_p(typeof(_A), typeof(_B)) || \
                 (IS_UNSIGNED_INTEGER_TYPE(_A) && IS_UNSIGNED_INTEGER_TYPE(_B)) || \
                 (IS_SIGNED_INTEGER_TYPE(_A) && IS_SIGNED_INTEGER_TYPE(_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);                             \
        })

#define MAX4(x, y, z, a)                                \
        ({                                              \
                const typeof(x) _d = MAX3(x, y, z);     \
                MAX(_d, a);                             \
        })

#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); \
        })

/* evaluates to (void) if _A or _B are not constant or of different types */
#define CONST_MIN(_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))

#define MIN3(x, y, z)                                   \
        ({                                              \
                const typeof(x) _c = MIN(x, y);         \
                MIN(_c, z);                             \
        })

/* Returns true if the passed integer is a positive power of two */
#define CONST_ISPOWEROF2(x)                     \
        ((x) > 0 && ((x) & ((x) - 1)) == 0)

#define ISPOWEROF2(x)                                                  \
        __builtin_choose_expr(                                         \
                __builtin_constant_p(x),                               \
                CONST_ISPOWEROF2(x),                                   \
                ({                                                     \
                        const typeof(x) _x = (x);                      \
                        CONST_ISPOWEROF2(_x);                          \
                }))

#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))); \
        })

/* Rounds up x to the next multiple of y. Resolves to typeof(x) -1 in case of overflow */
#define __ROUND_UP(q, x, y)                                             \
        ({                                                              \
                const typeof(y) UNIQ_T(A, q) = (y);                     \
                const typeof(x) UNIQ_T(B, q) = DIV_ROUND_UP((x), UNIQ_T(A, q)); \
                typeof(x) UNIQ_T(C, q);                                 \
                __builtin_mul_overflow(UNIQ_T(B, q), UNIQ_T(A, q), &UNIQ_T(C, q)) ? (typeof(x)) -1 : UNIQ_T(C, q); \
        })
#define ROUND_UP(x, y) __ROUND_UP(UNIQ, (x), (y))

#define  CASE_F_1(X)      case X:
#define  CASE_F_2(X, ...) case X:  CASE_F_1( __VA_ARGS__)
#define  CASE_F_3(X, ...) case X:  CASE_F_2( __VA_ARGS__)
#define  CASE_F_4(X, ...) case X:  CASE_F_3( __VA_ARGS__)
#define  CASE_F_5(X, ...) case X:  CASE_F_4( __VA_ARGS__)
#define  CASE_F_6(X, ...) case X:  CASE_F_5( __VA_ARGS__)
#define  CASE_F_7(X, ...) case X:  CASE_F_6( __VA_ARGS__)
#define  CASE_F_8(X, ...) case X:  CASE_F_7( __VA_ARGS__)
#define  CASE_F_9(X, ...) case X:  CASE_F_8( __VA_ARGS__)
#define CASE_F_10(X, ...) case X:  CASE_F_9( __VA_ARGS__)
#define CASE_F_11(X, ...) case X: CASE_F_10( __VA_ARGS__)
#define CASE_F_12(X, ...) case X: CASE_F_11( __VA_ARGS__)
#define CASE_F_13(X, ...) case X: CASE_F_12( __VA_ARGS__)
#define CASE_F_14(X, ...) case X: CASE_F_13( __VA_ARGS__)
#define CASE_F_15(X, ...) case X: CASE_F_14( __VA_ARGS__)
#define CASE_F_16(X, ...) case X: CASE_F_15( __VA_ARGS__)
#define CASE_F_17(X, ...) case X: CASE_F_16( __VA_ARGS__)
#define CASE_F_18(X, ...) case X: CASE_F_17( __VA_ARGS__)
#define CASE_F_19(X, ...) case X: CASE_F_18( __VA_ARGS__)
#define CASE_F_20(X, ...) case X: CASE_F_19( __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) \
                   (__VA_ARGS__)

#define IN_SET(x, first, ...)                                           \
        ({                                                              \
                bool _found = false;                                    \
                /* If the build breaks in the line below, you need to extend the case macros. We use typeof(+x) \
                 * here to widen the type of x if it is a bit-field as this would otherwise be illegal. */      \
                static const typeof(+x) __assert_in_set[] _unused_ = { first, __VA_ARGS__ }; \
                assert_cc(ELEMENTSOF(__assert_in_set) <= 20);           \
                switch (x) {                                            \
                FOR_EACH_MAKE_CASE(first, __VA_ARGS__)                  \
                        _found = true;                                  \
                        break;                                          \
                default:                                                \
                        break;                                          \
                }                                                       \
                _found;                                                 \
        })

/* Takes inspiration from Rust's Option::take() method: reads and returns a pointer, but at the same time
 * resets it to NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
#define TAKE_GENERIC(var, type, nullvalue)                       \
        ({                                                       \
                type *_pvar_ = &(var);                           \
                type _var_ = *_pvar_;                            \
                type _nullvalue_ = nullvalue;                    \
                *_pvar_ = _nullvalue_;                           \
                _var_;                                           \
        })
#define TAKE_PTR_TYPE(ptr, type) TAKE_GENERIC(ptr, type, NULL)
#define TAKE_PTR(ptr) TAKE_PTR_TYPE(ptr, typeof(ptr))
#define TAKE_STRUCT_TYPE(s, type) TAKE_GENERIC(s, type, {})
#define TAKE_STRUCT(s) TAKE_STRUCT_TYPE(s, typeof(s))

/*
 * 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"") - sizeof(typeof(x[0])))

#define mfree(memory)                           \
        ({                                      \
                free(memory);                   \
                (typeof(memory)) NULL;          \
        })

static inline size_t ALIGN_TO(size_t l, size_t ali) {
        assert(ISPOWEROF2(ali));

        if (l > SIZE_MAX - (ali - 1))
                return SIZE_MAX; /* indicate overflow */

        return ((l + ali - 1) & ~(ali - 1));
}

#define ALIGN2(l) ALIGN_TO(l, 2)
#define ALIGN4(l) ALIGN_TO(l, 4)
#define ALIGN8(l) ALIGN_TO(l, 8)
#define ALIGN2_PTR(p) ((void*) ALIGN2((uintptr_t) p))
#define ALIGN4_PTR(p) ((void*) ALIGN4((uintptr_t) p))
#define ALIGN8_PTR(p) ((void*) ALIGN8((uintptr_t) p))
#define ALIGN(l)  ALIGN_TO(l, sizeof(void*))
#define ALIGN_PTR(p) ((void*) ALIGN((uintptr_t) (p)))

/* Checks if the specified pointer is aligned as appropriate for the specific type */
#define IS_ALIGNED16(p) (((uintptr_t) p) % alignof(uint16_t) == 0)
#define IS_ALIGNED32(p) (((uintptr_t) p) % alignof(uint32_t) == 0)
#define IS_ALIGNED64(p) (((uintptr_t) p) % alignof(uint64_t) == 0)

/* Same as ALIGN_TO but callable in constant contexts. */
#define CONST_ALIGN_TO(l, ali)                                         \
        __builtin_choose_expr(                                         \
                __builtin_constant_p(l) &&                             \
                __builtin_constant_p(ali) &&                           \
                CONST_ISPOWEROF2(ali) &&                               \
                (l <= SIZE_MAX - (ali - 1)),      /* overflow? */      \
                ((l) + (ali) - 1) & ~((ali) - 1),                      \
                VOID_0)

/* Similar to ((t *) (void *) (p)) to cast a pointer. The macro asserts that the pointer has a suitable
 * alignment for type "t". This exists for places where otherwise "-Wcast-align=strict" would issue a
 * warning or if you want to assert that the cast gives a pointer of suitable alignment. */
#define CAST_ALIGN_PTR(t, p)                                    \
        ({                                                      \
                const void *_p = (p);                           \
                assert(((uintptr_t) _p) % alignof(t) == 0); \
                (t *) _p;                                       \
        })

#define UPDATE_FLAG(orig, flag, b)                      \
        ((b) ? ((orig) | (flag)) : ((orig) & ~(flag)))
#define SET_FLAG(v, flag, b) \
        (v) = UPDATE_FLAG(v, flag, b)
#define FLAGS_SET(v, flags) \
        ((~(v) & (flags)) == 0)

/* Declare a flexible array usable in a union.
 * This is essentially a work-around for a pointless constraint in C99
 * and might go away in some future version of the standard.
 *
 * See https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3080ea5553cc909b000d1f1d964a9041962f2c5b
 */
#define DECLARE_FLEX_ARRAY(type, name)                 \
        struct {                                       \
                dummy_t __empty__ ## name;             \
                type name[];                           \
        }

#ifdef SBAT_DISTRO
        #define DECLARE_SBAT(text) \
                static const char sbat[] _used_ _section_(".sbat") = (text)
#else
        #define DECLARE_SBAT(text)
#endif
Commit	Line	Data
e5bc5f1f YW	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	2	#pragma once
	3
493cd503	4	#if !SD_BOOT
c3e4cbe0	5	# include <assert.h>
e5bc5f1f YW	6	#endif
e5bc5f1f YW	7
a36a0d15	8	#include <limits.h>
1113e507	9	#include <stdalign.h>
6b852d22 JJ	10	#include <stdbool.h>
	11	#include <stddef.h>
	12	#include <stdint.h>
e5bc5f1f	13
9137c03c	14	#define _align_(x) __attribute__((__aligned__(x)))
1113e507	15	#define _alignas_(x) __attribute__((__aligned__(alignof(x))))
b41ebe3d JJ	16	#define _alignptr_ __attribute__((__aligned__(sizeof(void *))))
b41ebe3d JJ	17	#define _cleanup_(x) __attribute__((__cleanup__(x)))
e5bc5f1f	18	#define _const_ __attribute__((__const__))
b41ebe3d JJ	19	#define _deprecated_ __attribute__((__deprecated__))
	20	#define _destructor_ __attribute__((__destructor__))
	21	#define _hidden_ __attribute__((__visibility__("hidden")))
	22	#define _likely_(x) (__builtin_expect(!!(x), 1))
	23	#define _malloc_ __attribute__((__malloc__))
4f79f545	24	#define _noinline_ __attribute__((noinline))
b41ebe3d	25	#define _noreturn_ _Noreturn
1328150d	26	#define _packed_ __attribute__((__packed__))
b41ebe3d JJ	27	#define _printf_(a, b) __attribute__((__format__(printf, a, b)))
	28	#define _public_ __attribute__((__visibility__("default")))
	29	#define _pure_ __attribute__((__pure__))
a3aff1c4	30	#define _retain_ __attribute__((__retain__))
9148312f	31	#define _returns_nonnull_ __attribute__((__returns_nonnull__))
b41ebe3d JJ	32	#define _section_(x) __attribute__((__section__(x)))
b41ebe3d JJ	33	#define _sentinel_ __attribute__((__sentinel__))
f862e847	34	#define _unlikely_(x) (__builtin_expect(!!(x), 0))
b41ebe3d JJ	35	#define _unused_ __attribute__((__unused__))
	36	#define _used_ __attribute__((__used__))
	37	#define _warn_unused_result_ __attribute__((__warn_unused_result__))
	38	#define _weak_ __attribute__((__weak__))
	39	#define _weakref_(x) __attribute__((__weakref__(#x)))
	40
	41	#ifdef __clang__
	42	# define _alloc_(...)
	43	#else
	44	# define _alloc_(...) __attribute__((__alloc_size__(__VA_ARGS__)))
	45	#endif
	46
da519f8c	47	#if __GNUC__ >= 7 \|\| (defined(__clang__) && __clang_major__ >= 10)
b41ebe3d	48	# define _fallthrough_ __attribute__((__fallthrough__))
f862e847	49	#else
b41ebe3d	50	# define _fallthrough_
f862e847	51	#endif
e5bc5f1f	52
9137c03c DJL	53	#define XSTRINGIFY(x) #x
	54	#define STRINGIFY(x) XSTRINGIFY(x)
	55
e5bc5f1f YW	56	#ifndef __COVERITY__
	57	# define VOID_0 ((void)0)
	58	#else
	59	# define VOID_0 ((void*)0)
	60	#endif
	61
	62	#define ELEMENTSOF(x) \
	63	(__builtin_choose_expr( \
	64	!__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
	65	sizeof(x)/sizeof((x)[0]), \
	66	VOID_0))
	67
	68	#define XCONCATENATE(x, y) x ## y
	69	#define CONCATENATE(x, y) XCONCATENATE(x, y)
	70
493cd503	71	#if SD_BOOT
b1672234	72	_noreturn_ void efi_assert(const char expr, const char file, unsigned line, const char *function);
3b23a6c4	73
7a7267bf JJ	74	#ifdef NDEBUG
	75	#define assert(expr)
	76	#define assert_not_reached() __builtin_unreachable()
	77	#else
5a9b9157 JJ	78	#define assert(expr) ({ _likely_(expr) ? VOID_0 : efi_assert(#expr, __FILE__, __LINE__, __func__); })
5a9b9157 JJ	79	#define assert_not_reached() efi_assert("Code should not be reached", __FILE__, __LINE__, __func__)
7a7267bf	80	#endif
6c405f20	81	#define static_assert _Static_assert
5a9b9157	82	#define assert_se(expr) ({ _likely_(expr) ? VOID_0 : efi_assert(#expr, __FILE__, __LINE__, __func__); })
e5bc5f1f YW	83	#endif
e5bc5f1f YW	84
d821e40c	85	/* This passes the argument through after (if asserts are enabled) checking that it is not null. */
23cd0025 DT	86	#define ASSERT_PTR(expr) _ASSERT_PTR(expr, UNIQ_T(_expr_, UNIQ), assert)
	87	#define ASSERT_SE_PTR(expr) _ASSERT_PTR(expr, UNIQ_T(_expr_, UNIQ), assert_se)
	88	#define _ASSERT_PTR(expr, var, check) \
	89	({ \
	90	typeof(expr) var = (expr); \
	91	check(var); \
	92	var; \
8890ec82 LP	93	})
8890ec82 LP	94
724e13b3	95	#define ASSERT_NONNEG(expr) \
	96	({ \
	97	typeof(expr) _expr_ = (expr), _zero = 0; \
	98	assert(_expr_ >= _zero); \
	99	_expr_; \
	100	})
	101
	102	#define ASSERT_SE_NONNEG(expr) \
	103	({ \
	104	typeof(expr) _expr_ = (expr), _zero = 0; \
	105	assert_se(_expr_ >= _zero); \
	106	_expr_; \
	107	})
	108
6c405f20 JJ	109	#define assert_cc(expr) static_assert(expr, #expr)
6c405f20 JJ	110
e5bc5f1f YW	111	#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
	112	#define UNIQ __COUNTER__
	113
ea42da38 DS	114	/* Note that this works differently from pthread_once(): this macro does
	115	* not synchronize code execution, i.e. code that is run conditionalized
	116	* on this macro will run concurrently to all other code conditionalized
	117	* the same way, there's no ordering or completion enforced. */
	118	#define ONCE __ONCE(UNIQ_T(_once_, UNIQ))
9ddb63f5	119	#define __ONCE(o) \
	120	({ \
	121	static bool (o) = false; \
	122	__atomic_exchange_n(&(o), true, __ATOMIC_SEQ_CST); \
ea42da38 DS	123	})
ea42da38 DS	124
e5bc5f1f YW	125	#undef MAX
	126	#define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
	127	#define __MAX(aq, a, bq, b) \
	128	({ \
	129	const typeof(a) UNIQ_T(A, aq) = (a); \
	130	const typeof(b) UNIQ_T(B, bq) = (b); \
	131	UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
	132	})
	133
addae96a LP	134	#define IS_UNSIGNED_INTEGER_TYPE(type) \
	135	(__builtin_types_compatible_p(typeof(type), unsigned char) \|\| \
	136	__builtin_types_compatible_p(typeof(type), unsigned short) \|\| \
	137	__builtin_types_compatible_p(typeof(type), unsigned) \|\| \
	138	__builtin_types_compatible_p(typeof(type), unsigned long) \|\| \
	139	__builtin_types_compatible_p(typeof(type), unsigned long long))
	140
	141	#define IS_SIGNED_INTEGER_TYPE(type) \
	142	(__builtin_types_compatible_p(typeof(type), signed char) \|\| \
	143	__builtin_types_compatible_p(typeof(type), signed short) \|\| \
	144	__builtin_types_compatible_p(typeof(type), signed) \|\| \
	145	__builtin_types_compatible_p(typeof(type), signed long) \|\| \
	146	__builtin_types_compatible_p(typeof(type), signed long long))
	147
	148	/* Evaluates to (void) if _A or _B are not constant or of different types (being integers of different sizes
	149	* is also OK as long as the signedness matches) */
e5bc5f1f YW	150	#define CONST_MAX(_A, _B) \
	151	(__builtin_choose_expr( \
	152	__builtin_constant_p(_A) && \
	153	__builtin_constant_p(_B) && \
addae96a LP	154	(__builtin_types_compatible_p(typeof(_A), typeof(_B)) \|\| \
	155	(IS_UNSIGNED_INTEGER_TYPE(_A) && IS_UNSIGNED_INTEGER_TYPE(_B)) \|\| \
	156	(IS_SIGNED_INTEGER_TYPE(_A) && IS_SIGNED_INTEGER_TYPE(_B))), \
e5bc5f1f YW	157	((_A) > (_B)) ? (_A) : (_B), \
	158	VOID_0))
	159
	160	/* takes two types and returns the size of the larger one */
	161	#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
	162
	163	#define MAX3(x, y, z) \
	164	({ \
	165	const typeof(x) _c = MAX(x, y); \
	166	MAX(_c, z); \
	167	})
	168
	169	#define MAX4(x, y, z, a) \
	170	({ \
	171	const typeof(x) _d = MAX3(x, y, z); \
	172	MAX(_d, a); \
	173	})
	174
	175	#undef MIN
	176	#define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
	177	#define __MIN(aq, a, bq, b) \
	178	({ \
	179	const typeof(a) UNIQ_T(A, aq) = (a); \
	180	const typeof(b) UNIQ_T(B, bq) = (b); \
	181	UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
	182	})
	183
	184	/* evaluates to (void) if _A or _B are not constant or of different types */
	185	#define CONST_MIN(_A, _B) \
	186	(__builtin_choose_expr( \
	187	__builtin_constant_p(_A) && \
	188	__builtin_constant_p(_B) && \
	189	__builtin_types_compatible_p(typeof(_A), typeof(_B)), \
	190	((_A) < (_B)) ? (_A) : (_B), \
	191	VOID_0))
	192
	193	#define MIN3(x, y, z) \
	194	({ \
	195	const typeof(x) _c = MIN(x, y); \
	196	MIN(_c, z); \
	197	})
	198
c51e4c79 LP	199	/* Returns true if the passed integer is a positive power of two */
	200	#define CONST_ISPOWEROF2(x) \
	201	((x) > 0 && ((x) & ((x) - 1)) == 0)
	202
	203	#define ISPOWEROF2(x) \
	204	__builtin_choose_expr( \
	205	__builtin_constant_p(x), \
	206	CONST_ISPOWEROF2(x), \
	207	({ \
	208	const typeof(x) _x = (x); \
	209	CONST_ISPOWEROF2(_x); \
	210	}))
	211
e5bc5f1f YW	212	#define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
	213	#define __LESS_BY(aq, a, bq, b) \
	214	({ \
	215	const typeof(a) UNIQ_T(A, aq) = (a); \
	216	const typeof(b) UNIQ_T(B, bq) = (b); \
	217	UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
	218	})
	219
	220	#define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
	221	#define __CMP(aq, a, bq, b) \
	222	({ \
	223	const typeof(a) UNIQ_T(A, aq) = (a); \
	224	const typeof(b) UNIQ_T(B, bq) = (b); \
	225	UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 : \
	226	UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0; \
	227	})
	228
	229	#undef CLAMP
	230	#define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
	231	#define __CLAMP(xq, x, lowq, low, highq, high) \
	232	({ \
	233	const typeof(x) UNIQ_T(X, xq) = (x); \
	234	const typeof(low) UNIQ_T(LOW, lowq) = (low); \
	235	const typeof(high) UNIQ_T(HIGH, highq) = (high); \
	236	UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ? \
	237	UNIQ_T(HIGH, highq) : \
	238	UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ? \
	239	UNIQ_T(LOW, lowq) : \
	240	UNIQ_T(X, xq); \
	241	})
	242
	243	/* [(x + y - 1) / y] suffers from an integer overflow, even though the
	244	* computation should be possible in the given type. Therefore, we use
	245	* [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
	246	* quotient and the remainder, so both should be equally fast. */
	247	#define DIV_ROUND_UP(x, y) __DIV_ROUND_UP(UNIQ, (x), UNIQ, (y))
	248	#define __DIV_ROUND_UP(xq, x, yq, y) \
	249	({ \
	250	const typeof(x) UNIQ_T(X, xq) = (x); \
	251	const typeof(y) UNIQ_T(Y, yq) = (y); \
	252	(UNIQ_T(X, xq) / UNIQ_T(Y, yq) + !!(UNIQ_T(X, xq) % UNIQ_T(Y, yq))); \
	253	})
	254
beda8529 LP	255	/* Rounds up x to the next multiple of y. Resolves to typeof(x) -1 in case of overflow */
	256	#define __ROUND_UP(q, x, y) \
	257	({ \
	258	const typeof(y) UNIQ_T(A, q) = (y); \
	259	const typeof(x) UNIQ_T(B, q) = DIV_ROUND_UP((x), UNIQ_T(A, q)); \
	260	typeof(x) UNIQ_T(C, q); \
	261	__builtin_mul_overflow(UNIQ_T(B, q), UNIQ_T(A, q), &UNIQ_T(C, q)) ? (typeof(x)) -1 : UNIQ_T(C, q); \
	262	})
	263	#define ROUND_UP(x, y) __ROUND_UP(UNIQ, (x), (y))
	264
790f4dda JJ	265	#define CASE_F_1(X) case X:
	266	#define CASE_F_2(X, ...) case X: CASE_F_1( __VA_ARGS__)
	267	#define CASE_F_3(X, ...) case X: CASE_F_2( __VA_ARGS__)
	268	#define CASE_F_4(X, ...) case X: CASE_F_3( __VA_ARGS__)
	269	#define CASE_F_5(X, ...) case X: CASE_F_4( __VA_ARGS__)
	270	#define CASE_F_6(X, ...) case X: CASE_F_5( __VA_ARGS__)
	271	#define CASE_F_7(X, ...) case X: CASE_F_6( __VA_ARGS__)
	272	#define CASE_F_8(X, ...) case X: CASE_F_7( __VA_ARGS__)
	273	#define CASE_F_9(X, ...) case X: CASE_F_8( __VA_ARGS__)
	274	#define CASE_F_10(X, ...) case X: CASE_F_9( __VA_ARGS__)
	275	#define CASE_F_11(X, ...) case X: CASE_F_10( __VA_ARGS__)
	276	#define CASE_F_12(X, ...) case X: CASE_F_11( __VA_ARGS__)
	277	#define CASE_F_13(X, ...) case X: CASE_F_12( __VA_ARGS__)
	278	#define CASE_F_14(X, ...) case X: CASE_F_13( __VA_ARGS__)
	279	#define CASE_F_15(X, ...) case X: CASE_F_14( __VA_ARGS__)
	280	#define CASE_F_16(X, ...) case X: CASE_F_15( __VA_ARGS__)
	281	#define CASE_F_17(X, ...) case X: CASE_F_16( __VA_ARGS__)
	282	#define CASE_F_18(X, ...) case X: CASE_F_17( __VA_ARGS__)
	283	#define CASE_F_19(X, ...) case X: CASE_F_18( __VA_ARGS__)
	284	#define CASE_F_20(X, ...) case X: CASE_F_19( __VA_ARGS__)
e5bc5f1f YW	285
	286	#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
	287	#define FOR_EACH_MAKE_CASE(...) \
	288	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, \
	289	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) \
790f4dda	290	(__VA_ARGS__)
e5bc5f1f	291
4f06325c	292	#define IN_SET(x, first, ...) \
79893116	293	({ \
6b852d22	294	bool _found = false; \
0bc4ac52 JJ	295	/* If the build breaks in the line below, you need to extend the case macros. We use typeof(+x) \
0bc4ac52 JJ	296	* here to widen the type of x if it is a bit-field as this would otherwise be illegal. */ \
4f06325c	297	static const typeof(+x) __assert_in_set[] _unused_ = { first, __VA_ARGS__ }; \
79893116 YW	298	assert_cc(ELEMENTSOF(__assert_in_set) <= 20); \
79893116 YW	299	switch (x) { \
4f06325c	300	FOR_EACH_MAKE_CASE(first, __VA_ARGS__) \
6b852d22	301	_found = true; \
e967926b	302	break; \
79893116 YW	303	default: \
	304	break; \
	305	} \
	306	_found; \
e5bc5f1f YW	307	})
	308
	309	/* Takes inspiration from Rust's Option::take() method: reads and returns a pointer, but at the same time
	310	* resets it to NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
40c5cc2b DS	311	#define TAKE_GENERIC(var, type, nullvalue) \
	312	({ \
	313	type *_pvar_ = &(var); \
	314	type _var_ = *_pvar_; \
	315	type _nullvalue_ = nullvalue; \
	316	*_pvar_ = _nullvalue_; \
	317	_var_; \
e5bc5f1f	318	})
40c5cc2b DS	319	#define TAKE_PTR_TYPE(ptr, type) TAKE_GENERIC(ptr, type, NULL)
	320	#define TAKE_PTR(ptr) TAKE_PTR_TYPE(ptr, typeof(ptr))
	321	#define TAKE_STRUCT_TYPE(s, type) TAKE_GENERIC(s, type, {})
	322	#define TAKE_STRUCT(s) TAKE_STRUCT_TYPE(s, typeof(s))
f862e847 JJ	323
	324	/*
	325	* STRLEN - return the length of a string literal, minus the trailing NUL byte.
	326	* Contrary to strlen(), this is a constant expression.
	327	* @x: a string literal.
	328	*/
	329	#define STRLEN(x) (sizeof(""x"") - sizeof(typeof(x[0])))
200b1d99 MR	330
	331	#define mfree(memory) \
	332	({ \
	333	free(memory); \
	334	(typeof(memory)) NULL; \
	335	})
a36a0d15 JJ	336
a36a0d15 JJ	337	static inline size_t ALIGN_TO(size_t l, size_t ali) {
983ce0b5	338	assert(ISPOWEROF2(ali));
a36a0d15 JJ	339
	340	if (l > SIZE_MAX - (ali - 1))
	341	return SIZE_MAX; /* indicate overflow */
	342
	343	return ((l + ali - 1) & ~(ali - 1));
	344	}
	345
4f073883	346	#define ALIGN2(l) ALIGN_TO(l, 2)
4c8d7caf YW	347	#define ALIGN4(l) ALIGN_TO(l, 4)
4c8d7caf YW	348	#define ALIGN8(l) ALIGN_TO(l, 8)
4f073883 LP	349	#define ALIGN2_PTR(p) ((void*) ALIGN2((uintptr_t) p))
	350	#define ALIGN4_PTR(p) ((void*) ALIGN4((uintptr_t) p))
	351	#define ALIGN8_PTR(p) ((void*) ALIGN8((uintptr_t) p))
4c8d7caf YW	352	#define ALIGN(l) ALIGN_TO(l, sizeof(void*))
4c8d7caf YW	353	#define ALIGN_PTR(p) ((void*) ALIGN((uintptr_t) (p)))
4c8d7caf	354
4f073883	355	/* Checks if the specified pointer is aligned as appropriate for the specific type */
1113e507 YW	356	#define IS_ALIGNED16(p) (((uintptr_t) p) % alignof(uint16_t) == 0)
	357	#define IS_ALIGNED32(p) (((uintptr_t) p) % alignof(uint32_t) == 0)
	358	#define IS_ALIGNED64(p) (((uintptr_t) p) % alignof(uint64_t) == 0)
4f073883	359
a36a0d15 JJ	360	/* Same as ALIGN_TO but callable in constant contexts. */
	361	#define CONST_ALIGN_TO(l, ali) \
	362	__builtin_choose_expr( \
	363	__builtin_constant_p(l) && \
	364	__builtin_constant_p(ali) && \
983ce0b5	365	CONST_ISPOWEROF2(ali) && \
a36a0d15 JJ	366	(l <= SIZE_MAX - (ali - 1)), /* overflow? */ \
	367	((l) + (ali) - 1) & ~((ali) - 1), \
	368	VOID_0)
a8a7723b	369
86bdf117 TH	370	/* Similar to ((t ) (void ) (p)) to cast a pointer. The macro asserts that the pointer has a suitable
	371	* alignment for type "t". This exists for places where otherwise "-Wcast-align=strict" would issue a
	372	* warning or if you want to assert that the cast gives a pointer of suitable alignment. */
	373	#define CAST_ALIGN_PTR(t, p) \
	374	({ \
	375	const void *_p = (p); \
1113e507	376	assert(((uintptr_t) _p) % alignof(t) == 0); \
86bdf117 TH	377	(t *) _p; \
	378	})
	379
a8a7723b JJ	380	#define UPDATE_FLAG(orig, flag, b) \
	381	((b) ? ((orig) \| (flag)) : ((orig) & ~(flag)))
	382	#define SET_FLAG(v, flag, b) \
	383	(v) = UPDATE_FLAG(v, flag, b)
	384	#define FLAGS_SET(v, flags) \
	385	((~(v) & (flags)) == 0)
da8587b2 ZJS	386
	387	/* Declare a flexible array usable in a union.
	388	* This is essentially a work-around for a pointless constraint in C99
	389	* and might go away in some future version of the standard.
	390	*
	391	* See https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3080ea5553cc909b000d1f1d964a9041962f2c5b
	392	*/
	393	#define DECLARE_FLEX_ARRAY(type, name) \
	394	struct { \
	395	dummy_t __empty__ ## name; \
	396	type name[]; \
	397	}
c9bebec8 LB	398
	399	#ifdef SBAT_DISTRO
	400	#define DECLARE_SBAT(text) \
	401	static const char sbat[] _used_ _section_(".sbat") = (text)
	402	#else
	403	#define DECLARE_SBAT(text)
	404	#endif