/* 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> #ifndef LIBBPF_API #define LIBBPF_API __attribute__((visibility("default"))) #endif /* 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 DECLARE_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 */