-/* Definitions of OPENSSL_GLOBAL and OPENSSL_EXTERN,
- to define and declare certain global
- symbols that, with some compilers under VMS, have to be defined and
- declared explicitely with globaldef and globalref. On other OS:es,
- these macros are defined with something sensible. */
+/* Definitions of OPENSSL_GLOBAL and OPENSSL_EXTERN, to define and declare
+ certain global symbols that, with some compilers under VMS, have to be
+ defined and declared explicitely with globaldef and globalref.
+ Definitions of OPENSSL_EXPORT and OPENSSL_IMPORT, to define and declare
+ DLL exports and imports for compilers under Win32. These are a little
+ more complicated to use. Basically, for any library that exports some
+ global variables, the following code must be present in the header file
+ that declares them, before OPENSSL_EXTERN is used:
+
+ #ifdef SOME_BUILD_FLAG_MACRO
+ # undef OPENSSL_EXTERN
+ # define OPENSSL_EXTERN OPENSSL_EXPORT
+ #endif
+
+ The default is to have OPENSSL_EXPORT, OPENSSL_IMPORT and OPENSSL_GLOBAL
+ have some generally sensible values, and for OPENSSL_EXTERN to have the
+ value OPENSSL_IMPORT.
+*/