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

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

#ifndef SD_BOOT
#include <assert.h>
#endif

#include "type.h"

#define _align_(x) __attribute__((__aligned__(x)))
#define _const_ __attribute__((__const__))
#define _pure_ __attribute__((__pure__))
#define _section_(x) __attribute__((__section__(x)))
#define _used_ __attribute__((__used__))
#define _unused_ __attribute__((__unused__))
#define _cleanup_(x) __attribute__((__cleanup__(x)))

#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)

#ifdef SD_BOOT
#define assert(expr) do {} while (false)
#endif

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

#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);                             \
        })

#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);                             \
        })

#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))); \
        })

#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, ...)                          \
        ({                                      \
                sd_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.) */         \
                static const long double __assert_in_set[] _unused_ = { __VA_ARGS__ }; \
                assert_cc(ELEMENTSOF(__assert_in_set) <= 20); \
                switch(x) {                     \
                FOR_EACH_MAKE_CASE(__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_PTR(ptr)                           \
        ({                                      \
                typeof(ptr) _ptr_ = (ptr);      \
                (ptr) = NULL;                   \
                _ptr_;                          \
        })
Commit	Line	Data
e5bc5f1f YW	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	2	#pragma once
	3
	4	#ifndef SD_BOOT
	5	#include <assert.h>
	6	#endif
	7
	8	#include "type.h"
	9
9137c03c	10	#define _align_(x) __attribute__((__aligned__(x)))
e5bc5f1f YW	11	#define _const_ __attribute__((__const__))
e5bc5f1f YW	12	#define _pure_ __attribute__((__pure__))
9137c03c DJL	13	#define _section_(x) __attribute__((__section__(x)))
9137c03c DJL	14	#define _used_ __attribute__((__used__))
e5bc5f1f YW	15	#define _unused_ __attribute__((__unused__))
	16	#define _cleanup_(x) __attribute__((__cleanup__(x)))
	17
9137c03c DJL	18	#define XSTRINGIFY(x) #x
	19	#define STRINGIFY(x) XSTRINGIFY(x)
	20
e5bc5f1f YW	21	#ifndef __COVERITY__
	22	# define VOID_0 ((void)0)
	23	#else
	24	# define VOID_0 ((void*)0)
	25	#endif
	26
	27	#define ELEMENTSOF(x) \
	28	(__builtin_choose_expr( \
	29	!__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
	30	sizeof(x)/sizeof((x)[0]), \
	31	VOID_0))
	32
	33	#define XCONCATENATE(x, y) x ## y
	34	#define CONCATENATE(x, y) XCONCATENATE(x, y)
	35
	36	#ifdef SD_BOOT
	37	#define assert(expr) do {} while (false)
	38	#endif
	39
	40	#if defined(static_assert)
	41	#define assert_cc(expr) \
	42	static_assert(expr, #expr)
	43	#else
	44	#define assert_cc(expr) \
	45	struct CONCATENATE(_assert_struct_, __COUNTER__) { \
	46	char x[(expr) ? 0 : -1]; \
	47	}
	48	#endif
	49
	50	#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
	51	#define UNIQ __COUNTER__
	52
	53	#undef MAX
	54	#define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
	55	#define __MAX(aq, a, bq, b) \
	56	({ \
	57	const typeof(a) UNIQ_T(A, aq) = (a); \
	58	const typeof(b) UNIQ_T(B, bq) = (b); \
	59	UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
	60	})
	61
	62	/* evaluates to (void) if _A or _B are not constant or of different types */
	63	#define CONST_MAX(_A, _B) \
	64	(__builtin_choose_expr( \
	65	__builtin_constant_p(_A) && \
	66	__builtin_constant_p(_B) && \
	67	__builtin_types_compatible_p(typeof(_A), typeof(_B)), \
	68	((_A) > (_B)) ? (_A) : (_B), \
	69	VOID_0))
	70
	71	/* takes two types and returns the size of the larger one */
	72	#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
	73
	74	#define MAX3(x, y, z) \
	75	({ \
	76	const typeof(x) _c = MAX(x, y); \
	77	MAX(_c, z); \
	78	})
	79
	80	#define MAX4(x, y, z, a) \
	81	({ \
	82	const typeof(x) _d = MAX3(x, y, z); \
	83	MAX(_d, a); \
	84	})
85
86	#undef MIN
87	#define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
88	#define __MIN(aq, a, bq, b) \
89	({ \
90	const typeof(a) UNIQ_T(A, aq) = (a); \
91	const typeof(b) UNIQ_T(B, bq) = (b); \
92	UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
93	})
94
95	/* evaluates to (void) if _A or _B are not constant or of different types */
96	#define CONST_MIN(_A, _B) \
97	(__builtin_choose_expr( \
98	__builtin_constant_p(_A) && \
99	__builtin_constant_p(_B) && \
100	__builtin_types_compatible_p(typeof(_A), typeof(_B)), \
101	((_A) < (_B)) ? (_A) : (_B), \
102	VOID_0))
103
104	#define MIN3(x, y, z) \
105	({ \
106	const typeof(x) _c = MIN(x, y); \
107	MIN(_c, z); \
108	})
109
110	#define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
111	#define __LESS_BY(aq, a, bq, b) \
112	({ \
113	const typeof(a) UNIQ_T(A, aq) = (a); \
114	const typeof(b) UNIQ_T(B, bq) = (b); \
115	UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
116	})
117
118	#define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
119	#define __CMP(aq, a, bq, b) \
120	({ \
121	const typeof(a) UNIQ_T(A, aq) = (a); \
122	const typeof(b) UNIQ_T(B, bq) = (b); \
123	UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 : \
124	UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0; \
125	})
126
127	#undef CLAMP
128	#define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
129	#define __CLAMP(xq, x, lowq, low, highq, high) \
130	({ \
131	const typeof(x) UNIQ_T(X, xq) = (x); \
132	const typeof(low) UNIQ_T(LOW, lowq) = (low); \
133	const typeof(high) UNIQ_T(HIGH, highq) = (high); \
134	UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ? \
135	UNIQ_T(HIGH, highq) : \
136	UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ? \
137	UNIQ_T(LOW, lowq) : \
138	UNIQ_T(X, xq); \
139	})
140
141	/* [(x + y - 1) / y] suffers from an integer overflow, even though the
142	* computation should be possible in the given type. Therefore, we use
143	* [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
144	* quotient and the remainder, so both should be equally fast. */
145	#define DIV_ROUND_UP(x, y) __DIV_ROUND_UP(UNIQ, (x), UNIQ, (y))
146	#define __DIV_ROUND_UP(xq, x, yq, y) \
147	({ \
148	const typeof(x) UNIQ_T(X, xq) = (x); \
149	const typeof(y) UNIQ_T(Y, yq) = (y); \
150	(UNIQ_T(X, xq) / UNIQ_T(Y, yq) + !!(UNIQ_T(X, xq) % UNIQ_T(Y, yq))); \
151	})
152
153	#define CASE_F(X) case X:
154	#define CASE_F_1(CASE, X) CASE_F(X)
155	#define CASE_F_2(CASE, X, ...) CASE(X) CASE_F_1(CASE, __VA_ARGS__)
156	#define CASE_F_3(CASE, X, ...) CASE(X) CASE_F_2(CASE, __VA_ARGS__)
157	#define CASE_F_4(CASE, X, ...) CASE(X) CASE_F_3(CASE, __VA_ARGS__)
158	#define CASE_F_5(CASE, X, ...) CASE(X) CASE_F_4(CASE, __VA_ARGS__)
159	#define CASE_F_6(CASE, X, ...) CASE(X) CASE_F_5(CASE, __VA_ARGS__)
160	#define CASE_F_7(CASE, X, ...) CASE(X) CASE_F_6(CASE, __VA_ARGS__)
161	#define CASE_F_8(CASE, X, ...) CASE(X) CASE_F_7(CASE, __VA_ARGS__)
162	#define CASE_F_9(CASE, X, ...) CASE(X) CASE_F_8(CASE, __VA_ARGS__)
163	#define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
164	#define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
165	#define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
166	#define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
167	#define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
168	#define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
169	#define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
170	#define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
171	#define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
172	#define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
173	#define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
174
175	#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
176	#define FOR_EACH_MAKE_CASE(...) \
177	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, \
178	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) \
179	(CASE_F,__VA_ARGS__)
180
181	#define IN_SET(x, ...) \
182	({ \
183	sd_bool _found = false; \
184	/* If the build breaks in the line below, you need to extend the case macros. (We use "long double" as \
185	* type for the array, in the hope that checkers such as ubsan don't complain that the initializers for \
186	* the array are not representable by the base type. Ideally we'd use typeof(x) as base type, but that \
187	* doesn't work, as we want to use this on bitfields and gcc refuses typeof() on bitfields.) */ \
188	static const long double __assert_in_set[] _unused_ = { __VA_ARGS__ }; \
189	assert_cc(ELEMENTSOF(__assert_in_set) <= 20); \
190	switch(x) { \
191	FOR_EACH_MAKE_CASE(__VA_ARGS__) \
192	_found = true; \
193	break; \
194	default: \
195	break; \
196	} \
197	_found; \
198	})
199
200	/* Takes inspiration from Rust's Option::take() method: reads and returns a pointer, but at the same time
201	* resets it to NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
202	#define TAKE_PTR(ptr) \
203	({ \
204	typeof(ptr) _ptr_ = (ptr); \
205	(ptr) = NULL; \
206	_ptr_; \
207	})