1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 3 /* 4 * Common user-facing libbpf helpers. 5 * 6 * Copyright (c) 2019 Facebook 7 */ 8 9 #ifndef __LIBBPF_LIBBPF_COMMON_H 10 #define __LIBBPF_LIBBPF_COMMON_H 11 12 #include <string.h> 13 #include "libbpf_version.h" 14 15 #ifndef LIBBPF_API 16 #define LIBBPF_API __attribute__((visibility("default"))) 17 #endif 18 19 #define LIBBPF_DEPRECATED(msg) __attribute__((deprecated(msg))) 20 21 /* Mark a symbol as deprecated when libbpf version is >= {major}.{minor} */ 22 #define LIBBPF_DEPRECATED_SINCE(major, minor, msg) \ 23 __LIBBPF_MARK_DEPRECATED_ ## major ## _ ## minor \ 24 (LIBBPF_DEPRECATED("libbpf v" # major "." # minor "+: " msg)) 25 26 #define __LIBBPF_CURRENT_VERSION_GEQ(major, minor) \ 27 (LIBBPF_MAJOR_VERSION > (major) || \ 28 (LIBBPF_MAJOR_VERSION == (major) && LIBBPF_MINOR_VERSION >= (minor))) 29 30 /* Add checks for other versions below when planning deprecation of API symbols 31 * with the LIBBPF_DEPRECATED_SINCE macro. 32 */ 33 #if __LIBBPF_CURRENT_VERSION_GEQ(0, 6) 34 #define __LIBBPF_MARK_DEPRECATED_0_6(X) X 35 #else 36 #define __LIBBPF_MARK_DEPRECATED_0_6(X) 37 #endif 38 #if __LIBBPF_CURRENT_VERSION_GEQ(0, 7) 39 #define __LIBBPF_MARK_DEPRECATED_0_7(X) X 40 #else 41 #define __LIBBPF_MARK_DEPRECATED_0_7(X) 42 #endif 43 44 /* Helper macro to declare and initialize libbpf options struct 45 * 46 * This dance with uninitialized declaration, followed by memset to zero, 47 * followed by assignment using compound literal syntax is done to preserve 48 * ability to use a nice struct field initialization syntax and **hopefully** 49 * have all the padding bytes initialized to zero. It's not guaranteed though, 50 * when copying literal, that compiler won't copy garbage in literal's padding 51 * bytes, but that's the best way I've found and it seems to work in practice. 52 * 53 * Macro declares opts struct of given type and name, zero-initializes, 54 * including any extra padding, it with memset() and then assigns initial 55 * values provided by users in struct initializer-syntax as varargs. 56 */ 57 #define LIBBPF_OPTS(TYPE, NAME, ...) \ 58 struct TYPE NAME = ({ \ 59 memset(&NAME, 0, sizeof(struct TYPE)); \ 60 (struct TYPE) { \ 61 .sz = sizeof(struct TYPE), \ 62 __VA_ARGS__ \ 63 }; \ 64 }) 65 66 #endif /* __LIBBPF_LIBBPF_COMMON_H */ 67