From 977d07a3ae47ef204665d1eda2d642e5064724f3 Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Mon, 24 Jun 2019 12:01:19 +0200 Subject: Split build system into library and driver --- libbuild2/export.hxx | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 libbuild2/export.hxx (limited to 'libbuild2/export.hxx') diff --git a/libbuild2/export.hxx b/libbuild2/export.hxx new file mode 100644 index 0000000..514c845 --- /dev/null +++ b/libbuild2/export.hxx @@ -0,0 +1,58 @@ +#pragma once + +// Normally we don't export class templates (but do complete specializations), +// inline functions, and classes with only inline member functions. Exporting +// classes that inherit from non-exported/imported bases (e.g., std::string) +// will end up badly. The only known workarounds are to not inherit or to not +// export. Also, MinGW GCC doesn't like seeing non-exported functions being +// used before their inline definition. The workaround is to reorder code. In +// the end it's all trial and error. +// +// Exportation of explicit template instantiations is even hairier: MinGW GCC +// requires __declspec(dllexport) on the extern template declaration while VC +// wants it on the definition. Use LIBBUILD2_{DEC,DEF}EXPORT for that. +// + +#if defined(LIBBUILD2_STATIC) // Using static. +# define LIBBUILD2_SYMEXPORT +# define LIBBUILD2_DECEXPORT +#elif defined(LIBBUILD2_STATIC_BUILD) // Building static. +# define LIBBUILD2_SYMEXPORT +# define LIBBUILD2_DECEXPORT +# define LIBBUILD2_DEFEXPORT +#elif defined(LIBBUILD2_SHARED) // Using shared. +# ifdef _WIN32 +# define LIBBUILD2_SYMEXPORT __declspec(dllimport) +# define LIBBUILD2_DECEXPORT __declspec(dllimport) +# else +# define LIBBUILD2_SYMEXPORT +# define LIBBUILD2_DECEXPORT +# endif +#elif defined(LIBBUILD2_SHARED_BUILD) // Building shared. +# ifdef _WIN32 +# define LIBBUILD2_SYMEXPORT __declspec(dllexport) +# if defined(_MSC_VER) +# define LIBBUILD2_DECEXPORT +# define LIBBUILD2_DEFEXPORT __declspec(dllexport) +# else +# define LIBBUILD2_DECEXPORT __declspec(dllexport) +# define LIBBUILD2_DEFEXPORT +# endif +# else +# define LIBBUILD2_SYMEXPORT +# define LIBBUILD2_DECEXPORT +# define LIBBUILD2_DEFEXPORT +# endif +#else +// If none of the above macros are defined, then we assume we are being used +// by some third-party build system that cannot/doesn't signal the library +// type. Note that this fallback works for both static and shared but in case +// of shared will be sub-optimal compared to having dllimport. Also note that +// bootstrap ends up here as well. +// +// Using static or shared. +// +# define LIBBUILD2_SYMEXPORT +# define LIBBUILD2_DECEXPORT +# define LIBBUILD2_DEFEXPORT +#endif -- cgit v1.1