// Common/MyInitGuid.h #ifndef ZIP7_INC_COMMON_MY_INITGUID_H #define ZIP7_INC_COMMON_MY_INITGUID_H /* This file must be included only to one C++ file in project before declarations of COM interfaces with DEFINE_GUID macro. Each GUID must be initialized exactly once in project. There are two different versions of the DEFINE_GUID macro in guiddef.h (MyGuidDef.h): - if INITGUID is not defined: DEFINE_GUID declares an external reference to the symbol name. - if INITGUID is defined: DEFINE_GUID initializes the symbol name to the value of the GUID. Also we need IID_IUnknown that is initialized in some file for linking: MSVC: by default the linker uses some lib file that contains IID_IUnknown MinGW: add -luuid switch for linker WinCE: we define IID_IUnknown in this file Other: we define IID_IUnknown in this file */ // #include "Common.h" /* vc6 without sdk needs before , but it doesn't work in new msvc. So we include full "MyWindows.h" instead of */ // #include #include "MyWindows.h" #ifdef _WIN32 #ifdef __clang__ // #pragma GCC diagnostic ignored "-Wmissing-variable-declarations" #endif #ifdef UNDER_CE #include #endif // for vc6 without sdk we must define INITGUID here #define INITGUID #include #ifdef UNDER_CE DEFINE_GUID(IID_IUnknown, 0x00000000, 0x0000, 0x0000, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46); #endif #else // _WIN32 #define INITGUID #include "MyGuidDef.h" DEFINE_GUID(IID_IUnknown, 0x00000000, 0x0000, 0x0000, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46); #endif // _WIN32 #endif