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/* 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__ \ }; \ }) #endif /* __LIBBPF_LIBBPF_COMMON_H */