/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ /* * Common user-facing libbpf helpers. * * Copyright (c) 2019 Facebook */ #ifndef __LIBBPF_LIBBPF_COMMON_H#define __LIBBPF_LIBBPF_COMMON_H #include <string.h>#include "libbpf_version.h" #ifndef LIBBPF_API#define LIBBPF_API __attribute__((visibility("default")))#endif #define LIBBPF_DEPRECATED(msg) __attribute__((deprecated(msg))) /* Mark a symbol as deprecated when libbpf version is >= {major}.{minor} */#define LIBBPF_DEPRECATED_SINCE(major, minor, msg)			    \	__LIBBPF_MARK_DEPRECATED_ ## major ## _ ## minor		    \		(LIBBPF_DEPRECATED("libbpf v" # major "." # minor "+: " msg)) #define __LIBBPF_CURRENT_VERSION_GEQ(major, minor)			    \	(LIBBPF_MAJOR_VERSION > (major) ||				    \	 (LIBBPF_MAJOR_VERSION == (major) && LIBBPF_MINOR_VERSION >= (minor))) /* Add checks for other versions below when planning deprecation of API symbols * with the LIBBPF_DEPRECATED_SINCE macro. */#if __LIBBPF_CURRENT_VERSION_GEQ(1, 0)#define __LIBBPF_MARK_DEPRECATED_1_0(X) X#else#define __LIBBPF_MARK_DEPRECATED_1_0(X)#endif /* This set of internal macros allows to do "function overloading" based on * number of arguments provided by used in backwards-compatible way during the * transition to libbpf 1.0 * It's ugly but necessary evil that will be cleaned up when we get to 1.0. * See bpf_prog_load() overload for example. */#define ___libbpf_cat(A, B) A ## B#define ___libbpf_select(NAME, NUM) ___libbpf_cat(NAME, NUM)#define ___libbpf_nth(_1, _2, _3, _4, _5, _6, N, ...) N#define ___libbpf_cnt(...) ___libbpf_nth(__VA_ARGS__, 6, 5, 4, 3, 2, 1)#define ___libbpf_overload(NAME, ...) ___libbpf_select(NAME, ___libbpf_cnt(__VA_ARGS__))(__VA_ARGS__) /* Helper macro to declare and initialize libbpf options struct * * This dance with uninitialized declaration, followed by memset to zero, * followed by assignment using compound literal syntax is done to preserve * ability to use a nice struct field initialization syntax and **hopefully** * have all the padding bytes initialized to zero. It's not guaranteed though, * when copying literal, that compiler won't copy garbage in literal's padding * bytes, but that's the best way I've found and it seems to work in practice. * * Macro declares opts struct of given type and name, zero-initializes, * including any extra padding, it with memset() and then assigns initial * values provided by users in struct initializer-syntax as varargs. */#define LIBBPF_OPTS(TYPE, NAME, ...)					    \	struct TYPE NAME = ({ 						    \		memset(&NAME, 0, sizeof(struct TYPE));			    \		(struct TYPE) {						    \			.sz = sizeof(struct TYPE),			    \			__VA_ARGS__					    \		};							    \	}) /* Helper macro to clear and optionally reinitialize libbpf options struct * * Small helper macro to reset all fields and to reinitialize the common * structure size member. Values provided by users in struct initializer- * syntax as varargs can be provided as well to reinitialize options struct * specific members. */#define LIBBPF_OPTS_RESET(NAME, ...)					    \	do {								    \		typeof(NAME) ___##NAME = ({ 				    \			memset(&___##NAME, 0, sizeof(NAME));		    \			(typeof(NAME)) {				    \				.sz = sizeof(NAME),			    \				__VA_ARGS__				    \			};						    \		});							    \		memcpy(&NAME, &___##NAME, sizeof(NAME));		    \	} while (0) #endif /* __LIBBPF_LIBBPF_COMMON_H */