-/* 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:
+# if defined(OPENSSL_SYS_VMS_NODECC)
+# define OPENSSL_EXPORT globalref
+# define OPENSSL_IMPORT globalref
+# define OPENSSL_GLOBAL globaldef
+# elif defined(OPENSSL_SYS_WINDOWS) && defined(OPENSSL_OPT_WINDLL)
+# define OPENSSL_EXPORT extern __declspec(dllexport)
+# define OPENSSL_IMPORT extern __declspec(dllimport)
+# define OPENSSL_GLOBAL
+# else
+# define OPENSSL_EXPORT extern
+# define OPENSSL_IMPORT extern
+# define OPENSSL_GLOBAL
+# endif
+# define OPENSSL_EXTERN OPENSSL_IMPORT
+
+/*-
+ * Macros to allow global variables to be reached through function calls when
+ * required (if a shared library version requires it, for example.
+ * The way it's done allows definitions like this:
+ *
+ * // in foobar.c
+ * OPENSSL_IMPLEMENT_GLOBAL(int,foobar,0)
+ * // in foobar.h
+ * OPENSSL_DECLARE_GLOBAL(int,foobar);
+ * #define foobar OPENSSL_GLOBAL_REF(foobar)
+ */
+# ifdef OPENSSL_EXPORT_VAR_AS_FUNCTION
+# define OPENSSL_IMPLEMENT_GLOBAL(type,name,value) \
+ type *_shadow_##name(void) \
+ { static type _hide_##name=value; return &_hide_##name; }
+# define OPENSSL_DECLARE_GLOBAL(type,name) type *_shadow_##name(void)
+# define OPENSSL_GLOBAL_REF(name) (*(_shadow_##name()))
+# else
+# define OPENSSL_IMPLEMENT_GLOBAL(type,name,value) OPENSSL_GLOBAL type _shadow_##name=value;
+# define OPENSSL_DECLARE_GLOBAL(type,name) OPENSSL_EXPORT type _shadow_##name
+# define OPENSSL_GLOBAL_REF(name) _shadow_##name
+# endif