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Diffstat (limited to 'include/ws_attributes.h')
| -rw-r--r-- | include/ws_attributes.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/include/ws_attributes.h b/include/ws_attributes.h new file mode 100644 index 0000000000..4446c4aec3 --- /dev/null +++ b/include/ws_attributes.h @@ -0,0 +1,131 @@ +/* ws_attributes.h + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef __WS_ATTRIBUTES_H__ +#define __WS_ATTRIBUTES_H__ + +#include "ws_compiler_tests.h" + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* + * If we're running GCC or clang define _U_ to be "__attribute__((unused))" + * so we can use _U_ to flag unused function parameters and not get warnings + * about them. Otherwise, define _U_ to be an empty string so that _U_ used + * to flag an unused function parameters will compile with other compilers. + * + * XXX - similar hints for other compilers? + */ +#if defined(__GNUC__) || defined(__clang__) + #define _U_ __attribute__((unused)) +#elif defined(_MSC_VER) + #define _U_ __pragma(warning(suppress:4100 4189)) +#else + #define _U_ +#endif + +/* + * WS_NORETURN, before a function declaration, means "this function + * never returns". (It must go before the function declaration, e.g. + * "extern WS_NORETURN func(...)" rather than after the function + * declaration, as the MSVC version has to go before the declaration.) + */ +#ifndef __cplusplus + #define WS_NORETURN _Noreturn +#else /* __cplusplus */ +#if __has_attribute(noreturn) \ + || WS_IS_AT_LEAST_GNUC_VERSION(2,5) \ + || WS_IS_AT_LEAST_SUNC_VERSION(5,9) \ + || WS_IS_AT_LEAST_XL_C_VERSION(10,1) \ + || WS_IS_AT_LEAST_HP_C_VERSION(6,10) + /* + * Compiler with support for __attribute__((noreturn)), or GCC 2.5 and + * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1 + * and later (do any earlier versions of XL C support this?), or + * HP aCC A.06.10 and later. + */ + #define WS_NORETURN __attribute__((noreturn)) +#elif defined(_MSC_VER) + /* + * MSVC. + */ + #define WS_NORETURN __declspec(noreturn) +#else + #define WS_NORETURN +#endif +#endif /* __cplusplus */ + +/* + * WS_RETNONNULL, before a function declaration, means "this function + * always returns a non-null pointer". + */ +#if __has_attribute(returns_nonnull) \ + || WS_IS_AT_LEAST_GNUC_VERSION(4,9) + #define WS_RETNONNULL __attribute__((returns_nonnull)) +#else + #define WS_RETNONNULL +#endif + +/* + * WS_DEPRECATED, before a function declaration, means "this function + * should not be used anymore and will be removed in a future version". + * WS_DEPRECATED_X() optionally takes a message saying what should be done + * instead (strongly recommended). + * + * This is not implemented on purpose with MSVC because that compiler has no + * equivalent to -Wno-error=deprecated-declarations, making it impossible + * to build with -Werror and deprecated declarations. The Microsoft developer + * team seems to not understand the requirement. + * https://developercommunity.visualstudio.com/t/cant-treat-deprecated-warning-as-warning-with-wx/786502 + * https://developercommunity.visualstudio.com/t/impossible-to-treat-warning-as-error-except-specif/473936 + */ +#if __has_attribute(deprecated) + #define WS_DEPRECATED __attribute__((deprecated)) + #define WS_DEPRECATED_X(msg) __attribute__((deprecated(msg))) +#else + #define WS_DEPRECATED + #define WS_DEPRECATED_X(msg) +#endif + +/* + * WS_THREAD_LOCAL means "this variable should go in thread-local + * storage. + * + * Based on + * + * https://en.wikipedia.org/w/index.php?title=Thread-local_storage&oldid=1064900318#C_and_C++ + * + * the major UN*X C compilers support __thread and the major Windows C + * compilers support __declspec(thread). + */ +#ifdef _MSC_VER + #define WS_THREAD_LOCAL __declspec(thread) +#else + #define WS_THREAD_LOCAL __thread +#endif + +/* + * The warn_unused_result attribute causes a warning to be emitted if a caller + * of the function with this attribute does not use its return value. This is + * useful for functions where not checking the result is either a security + * problem or always a bug, such as realloc. + */ +#if defined(__GNUC__) || defined(__clang__) + #define WS_WARN_UNUSED __attribute__((warn_unused_result)) +#else + #define WS_WARN_UNUSED +#endif + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* __WS_ATTRIBUTES_H__ */ |