Expect DLL builds on Windows by default and require a custom __config for static builds. On Windows the __declspec(dllimport) and __declspec(dllexport) attributes require linking to a DLL, not a static library. Previously these annotations were disabled by default unless _LIBCPP_DLL was defined. However the DLL configuration is probably the more common one, so it should be supported by default. This patch enables import/export attributes by default and adds a _LIBCPP_DISABLE_DLL_IMPORT_EXPORT macro which can be used to disable this behavior. If libc++ is built as a static library on Windows then a custom __config header will be generated that predefines this macro. This patch is based off work by Shoaib Meenai. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@282449 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt index a80349a..5904c06 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt
@@ -330,6 +330,8 @@ # headers add_compile_flags_if_supported(-nostdinc++) +# Let the library headers know they are currently being used to build the +# library. add_definitions(-D_LIBCPP_BUILDING_LIBRARY) # Warning flags =============================================================== @@ -455,6 +457,14 @@ config_define_if(LIBCXX_HAS_EXTERNAL_THREAD_API _LIBCPP_HAS_THREAD_API_EXTERNAL) config_define_if(LIBCXX_HAS_MUSL_LIBC _LIBCPP_HAS_MUSL_LIBC) +# By default libc++ on Windows expects to use a shared library, which requires +# the headers to use DLL import/export semantics. However when building a +# static library only we modify the headers to disable DLL import/export. +if (DEFINED WIN32 AND LIBCXX_ENABLE_STATIC AND NOT LIBCXX_ENABLE_SHARED) + message(STATUS "Generating custom __config for non-DLL Windows build") + config_define(ON _LIBCPP_DISABLE_DLL_IMPORT_EXPORT) +endif() + if (LIBCXX_NEEDS_SITE_CONFIG) configure_file( include/__config_site.in
diff --git a/include/__config b/include/__config index 9f90a5b..b0a3091 100644 --- a/include/__config +++ b/include/__config
@@ -519,20 +519,20 @@ #ifdef _WIN32 -// only really useful for a DLL. _LIBCPP_DLL should be a compiler builtin define ideally... -#if defined(_LIBCPP_DLL) && defined(cxx_EXPORTS) -# define _LIBCPP_DLL_VIS __declspec(dllexport) -# define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS -# define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS -#elif defined(_LIBCPP_DLL) -# define _LIBCPP_DLL_VIS __declspec(dllimport) -# define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS -# define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS -#else +#if defined(_LIBCPP_DISABLE_DLL_IMPORT_EXPORT) # define _LIBCPP_DLL_VIS # define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS # define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS +#elif defined(_LIBCPP_BUILDING_LIBRARY) +# define _LIBCPP_DLL_VIS __declspec(dllexport) +# define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS +# define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS +#else +# define _LIBCPP_DLL_VIS __declspec(dllimport) +# define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS +# define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS #endif + #define _LIBCPP_TYPE_VIS _LIBCPP_DLL_VIS #define _LIBCPP_FUNC_VIS _LIBCPP_DLL_VIS #define _LIBCPP_EXCEPTION_ABI _LIBCPP_DLL_VIS
diff --git a/include/__config_site.in b/include/__config_site.in index dce30bc..ba0e8be 100644 --- a/include/__config_site.in +++ b/include/__config_site.in
@@ -21,5 +21,6 @@ #cmakedefine _LIBCPP_HAS_MUSL_LIBC #cmakedefine _LIBCPP_HAS_THREAD_API_PTHREAD #cmakedefine _LIBCPP_HAS_THREAD_API_EXTERNAL +#cmakedefine _LIBCPP_DISABLE_DLL_IMPORT_EXPORT #endif // _LIBCPP_CONFIG_SITE
