Jacek Caban : guiddef.h: Improve __uuidof implementation.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 51b75e9a534d8c6021bbcc71889e3c154f0f84ea
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=51b75e9a534d8c6021bbcc71889e3c154f0f84ea

Author: Jacek Caban <jacek at codeweavers.com>
Date:   Wed Feb  5 17:12:22 2020 +0100

guiddef.h: Improve __uuidof implementation.

This patch ensures that the reference is unique and identical for all
uses in module, fixes handling of const types and uses direct reference
instead of depending on optimizer to produce sane code.

Based on patch by Kevin Puetz.

Signed-off-by: Jacek Caban <jacek at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 include/guiddef.h | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/include/guiddef.h b/include/guiddef.h
index cc26e8b3a5..9fc40c73eb 100644
--- a/include/guiddef.h
+++ b/include/guiddef.h
@@ -42,30 +42,45 @@ typedef struct _GUID
 #endif
 
 /* Macros for __uuidof emulation */
-#if defined(__cplusplus) && !defined(_MSC_VER)
+#ifdef __cplusplus
+# if defined(__MINGW32__)
+#  define __WINE_UUID_ATTR __attribute__((selectany))
+# elif defined(__GNUC__)
+#  define __WINE_UUID_ATTR __attribute__((visibility("hidden"),weak))
+# endif
+#endif
+
+#ifdef __WINE_UUID_ATTR
 
 extern "C++" {
-    template<typename T> const GUID &__wine_uuidof();
+    template<typename T> struct __wine_uuidof;
+
+    template<typename T> struct __wine_uuidof_type {
+        typedef __wine_uuidof<T> inst;
+    };
+    template<typename T> struct __wine_uuidof_type<T *> {
+        typedef __wine_uuidof<T> inst;
+    };
+    template<typename T> struct __wine_uuidof_type<T * const> {
+        typedef __wine_uuidof<T> inst;
+    };
 }
 
 #define __CRT_UUID_DECL(type,l,w1,w2,b1,b2,b3,b4,b5,b6,b7,b8)           \
     extern "C++" {                                                      \
-    template<> inline const GUID &__wine_uuidof<type>() {               \
-        static const IID __uuid_inst = {l,w1,w2, {b1,b2,b3,b4,b5,b6,b7,b8}}; \
-        return __uuid_inst;                                             \
-    }                                                                   \
-    template<> inline const GUID &__wine_uuidof<type*>() {              \
-        return __wine_uuidof<type>();                                   \
-    }                                                                   \
+        template<> struct __wine_uuidof<type> {                         \
+            static const GUID uuid;                                     \
+        };                                                              \
+        __WINE_UUID_ATTR const GUID __wine_uuidof<type>::uuid = {l,w1,w2,{b1,b2,b3,b4,b5,b6,b7,b8}}; \
     }
 
-#define __uuidof(type) __wine_uuidof<typeof(type)>()
+#define __uuidof(type) __wine_uuidof_type<typeof(type)>::inst::uuid
 
-#else
+#else /* __WINE_UUID_ATTR */
 
 #define __CRT_UUID_DECL(type,l,w1,w2,b1,b2,b3,b4,b5,b6,b7,b8)
 
-#endif
+#endif /* __WINE_UUID_ATTR */
 
 #endif