Windows symbol export fix. Move to GCC.

1 files changed, 27 insertions, 13 deletions

diff --git a/include/ffi.h.in b/include/ffi.h.in
index 84017f1..4f3b3de 100644
--- a/include/ffi.h.in
+++ b/include/ffi.h.in
@@ -166,22 +166,36 @@ typedef struct _ffi_type
  #error "long size not supported"
 #endif
 
+/* Need minimal decorations for DLLs to works on Windows. */
+/* GCC has autoimport and autoexport.  Rely on Libtool to */
+/* help MSVC export from a DLL, but always declare data   */
+/* to be imported for MSVC clients.  This costs an extra  */
+/* indirection for MSVC clients using the static version  */
+/* of the library, but don't worry about that.  Besides,  */
+/* as a workaround, they can define FFI_BUILDING if they  */
+/* *know* they are going to link with the static library. */
+#if defined _MSC_VER && !defined FFI_BUILDING
+#define FFI_EXTERN extern __declspec(dllimport)
+#else
+#define FFI_EXTERN extern
+#endif
+
 /* These are defined in types.c */
-extern ffi_type ffi_type_void;
-extern ffi_type ffi_type_uint8;
-extern ffi_type ffi_type_sint8;
-extern ffi_type ffi_type_uint16;
-extern ffi_type ffi_type_sint16;
-extern ffi_type ffi_type_uint32;
-extern ffi_type ffi_type_sint32;
-extern ffi_type ffi_type_uint64;
-extern ffi_type ffi_type_sint64;
-extern ffi_type ffi_type_float;
-extern ffi_type ffi_type_double;
-extern ffi_type ffi_type_pointer;
+FFI_EXTERN ffi_type ffi_type_void;
+FFI_EXTERN ffi_type ffi_type_uint8;
+FFI_EXTERN ffi_type ffi_type_sint8;
+FFI_EXTERN ffi_type ffi_type_uint16;
+FFI_EXTERN ffi_type ffi_type_sint16;
+FFI_EXTERN ffi_type ffi_type_uint32;
+FFI_EXTERN ffi_type ffi_type_sint32;
+FFI_EXTERN ffi_type ffi_type_uint64;
+FFI_EXTERN ffi_type ffi_type_sint64;
+FFI_EXTERN ffi_type ffi_type_float;
+FFI_EXTERN ffi_type ffi_type_double;
+FFI_EXTERN ffi_type ffi_type_pointer;
 
 #if @HAVE_LONG_DOUBLE@
-extern ffi_type ffi_type_longdouble;
+FFI_EXTERN ffi_type ffi_type_longdouble;
 #else
 #define ffi_type_longdouble ffi_type_double
 #endif