[Mingw-users] COM support and INITGUID

[Devin S. <dev...@gm...>]

Hi,

How exactly does INITGUID ever get defined?

I have this in my header file:

#include <objbase.h>
#include <initguid.h>

/* Define the library ID (LIBID) */
DEFINE_GUID(LIBID_mingwcom, 0x6fc10990,0xbc73,0x4dff,0xab, 0x63, 0xdf,
0xb1, 0x86, 0x8, 0x1e, 0x81);

Since INITGUID never gets defined the preprocessor converts this
DEFINE_GUID into

extern const GUID LIBID_mingwcom =
{0x6fc10990,0xbc73,0x4dff,{0xab,0x63,0xdf,0xb1,0x86,0x8,0x1e,0x81}};

and this causes a warning with gcc:
warning: `LIBID_mingwcom' initialized and declared `extern'

Now I can fix this by going into include/basetyps.h around line 170 and flipping
the !defined(INITGUID) to a defined(INITGUID) and the warning goes away.
This seems like a bad solution though.  What is the correct solution?

In this file, around line 170 we have:

#if !defined(INITGUID) || (defined(INITGUID) && defined(__cplusplus))
#define GUID_EXT EXTERN_C
#else
#define GUID_EXT
#endif

The change flips it to:

#if defined(INITGUID) || (defined(INITGUID) && defined(__cplusplus))
#define GUID_EXT EXTERN_C
#else
#define GUID_EXT
#endif

Thanks in advance,

Devin Smith