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Diffstat (limited to 'include/ws_symbol_export.h')
| -rw-r--r-- | include/ws_symbol_export.h | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/include/ws_symbol_export.h b/include/ws_symbol_export.h new file mode 100644 index 00000000..3de71a8a --- /dev/null +++ b/include/ws_symbol_export.h @@ -0,0 +1,217 @@ +/** @file + * Cross platform defines for exporting symbols from shared libraries + * + * Wireshark - Network traffic analyzer + * By Balint Reczey <balint@balintreczey.hu> + * Copyright 2013 Balint Reczey + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "ws_compiler_tests.h" + +/** Reset symbol export behavior. + * If you {un}define WS_BUILD_DLL on the fly you'll have to define this + * as well. + */ +#ifdef RESET_SYMBOL_EXPORT + +#ifdef SYMBOL_EXPORT_H +#undef SYMBOL_EXPORT_H +#endif + +#ifdef WS_DLL_PUBLIC +#undef WS_DLL_PUBLIC +#endif + +#ifdef WS_DLL_PUBLIC_DEF +#undef WS_DLL_PUBLIC_DEF +#endif + +#ifdef WS_DLL_LOCAL +#undef WS_DLL_LOCAL +#endif + +#endif /* RESET_SYMBOL_EXPORT */ + +#ifndef SYMBOL_EXPORT_H +#define SYMBOL_EXPORT_H + +/* + * NOTE: G_HAVE_GNUC_VISIBILITY is defined only if all of + * + * __attribute__ ((visibility ("hidden"))) + * + * __attribute__ ((visibility ("internal"))) + * + * __attribute__ ((visibility ("protected"))) + * + * __attribute__ ((visibility ("default"))) + * + * are supported, and at least some versions of GCC from Apple support + * "default" and "hidden" but not "internal" or "protected", so it + * shouldn't be used to determine whether "hidden" or "default" is + * supported. + * + * This also means that we shouldn't use G_GNUC_INTERNAL instead of + * WS_DLL_LOCAL, as GLib uses G_HAVE_GNUC_VISIBILITY to determine + * whether to use __attribute__ ((visibility ("hidden"))) for + * G_GNUC_INTERNAL, and that will not use it even with compilers + * that support it. + */ + +/* Originally copied from GCC Wiki at https://gcc.gnu.org/wiki/Visibility */ +#if defined _WIN32 || defined __CYGWIN__ + /* Compiling for Windows, so we use the Windows DLL declarations. */ + #ifdef WS_BUILD_DLL + /* + * Building a DLL; for all definitions, we want dllexport, and + * (presumably so source from DLL and source from a program using the + * DLL can both include a header that declares APIs and exported data + * for the DLL), for declarations, either dllexport or dllimport will + * work (they mean the same thing for a declaration when building a DLL). + */ + #ifdef __GNUC__ + /* GCC */ + #define WS_DLL_PUBLIC_DEF __attribute__ ((dllexport)) + #else /* ! __GNUC__ */ + /* + * Presumably MSVC. + * Note: actually gcc seems to also support this syntax. + */ + #define WS_DLL_PUBLIC_DEF __declspec(dllexport) + #endif /* __GNUC__ */ + #else /* WS_BUILD_DLL */ + /* + * Building a program; we should only see declarations, not definitions, + * with WS_DLL_PUBLIC, and they all represent APIs or data imported + * from a DLL, so use dllimport. + * + * For functions, export shouldn't be necessary; for data, it might + * be necessary, e.g. if what's declared is an array whose size is + * not given in the declaration. + */ + #ifdef ENABLE_STATIC + /* + * We're building all-static, so we're not building any DLLs. + */ + #define WS_DLL_PUBLIC_DEF + #elif defined(__GNUC__) + /* GCC */ + #define WS_DLL_PUBLIC_DEF __attribute__ ((dllimport)) + #else /* ! ENABLE_STATIC && ! __GNUC__ */ + /* + * Presumably MSVC, and we're not building all-static. + * Note: actually gcc seems to also support this syntax. + */ + #define WS_DLL_PUBLIC_DEF __declspec(dllimport) + #endif + #endif /* WS_BUILD_DLL */ + + /* + * Symbols in a DLL are *not* exported unless they're specifically + * flagged as exported, so, for a non-static but non-exported + * symbol, we don't have to do anything. + */ + #define WS_DLL_LOCAL +#else /* defined _WIN32 || defined __CYGWIN__ */ + /* + * Compiling for UN*X, where the dllimport and dllexport stuff + * is neither necessary nor supported; just specify the + * visibility if we have a compiler that supports doing so. + */ + #if WS_IS_AT_LEAST_GNUC_VERSION(3,4) \ + || WS_IS_AT_LEAST_XL_C_VERSION(12,0) + /* + * GCC 3.4 or later, or some compiler asserting compatibility with + * GCC 3.4 or later, or XL C 13.0 or later, so we have + * __attribute__((visibility()). + */ + + /* + * Symbols exported from libraries. + */ + #define WS_DLL_PUBLIC_DEF __attribute__ ((visibility ("default"))) + + /* + * Non-static symbols *not* exported from libraries. + */ + #define WS_DLL_LOCAL __attribute__ ((visibility ("hidden"))) + #elif WS_IS_AT_LEAST_SUNC_VERSION(5,5) + /* + * Sun C 5.5 or later, so we have __global and __hidden. + * (Sun C 5.9 and later also have __attribute__((visibility()), + * but there's no reason to prefer it with Sun C.) + */ + + /* + * Symbols exported from libraries. + */ + #define WS_DLL_PUBLIC_DEF __global + + /* + * Non-static symbols *not* exported from libraries. + */ + #define WS_DLL_LOCAL __hidden + #else + /* + * We have neither a way to make stuff not explicitly marked as + * visible invisible outside a library nor a way to make stuff + * explicitly marked as local invisible outside the library. + */ + + /* + * Symbols exported from libraries. + */ + #define WS_DLL_PUBLIC_DEF + + /* + * Non-static symbols *not* exported from libraries. + */ + #define WS_DLL_LOCAL + #endif +#endif + +/* + * You *must* use this for exported data *declarations*; if you use + * WS_DLL_PUBLIC_DEF, some compilers, such as MSVC++, will complain + * about array definitions with no size. + * + * You must *not* use this for exported data *definitions*, as that + * will, for some compilers, cause warnings about items being initialized + * and declared extern. + * + * Either can be used for exported *function* declarations and definitions. + */ +#define WS_DLL_PUBLIC WS_DLL_PUBLIC_DEF extern + +/* + * This is necessary to export symbols from wsutil to another DLL + * (not an executable) using MSVC. + */ +#ifdef _MSC_VER +# ifdef BUILD_WSUTIL +# define WSUTIL_EXPORT __declspec(dllexport) extern +# else +# define WSUTIL_EXPORT __declspec(dllimport) extern +# endif +#else /* _MSC_VER */ +# define WSUTIL_EXPORT WS_DLL_PUBLIC +#endif /* _MSC_VER */ + + + +#endif /* SYMBOL_EXPORT_H */ + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local Variables: + * c-basic-offset: 2 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=2 tabstop=8 expandtab: + * :indentSize=2:tabSize=8:noTabs=true: + */ |