[Mingw-users] Problem with nesting macro ?

[Mauricio G. <mgp...@gm...>]

Hi,

I have encountered this problem while compiling webconnect (
http://www.kirix.com/labs/wxwebconnect/downloads.html).
I am using mingw 5.1.4 with Code::Blocks.

Please consider the following code:
#include <stddef.h>

#define NS_ISUPPORTS_IID \
  {0x00000000, 0x0000, 0x0000, \
    { 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46 }}


#define NS_DECLARE_STATIC_IID_ACCESSOR(iid) \
    static const nsIID& GetIID() { \
        static nsIID nsiid = iid; \
        return nsiid; \
    }

#define NS_DEFINE_STATIC_IID_ACCESSOR(iid)
NS_DECLARE_STATIC_IID_ACCESSOR(iid)

struct nsID
{
    long m0;
    int m1;
    int m2;
    unsigned char m3[8];
};

typedef nsID nsIID;

class c
{
    public:
    NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISUPPORTS_IID) // This compiles okay.
    NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISUPPORTS_IID)    // This does not
compile.
};

Could somebody please explain to me why the "last" line does not compile ?

c:\projects\webconnect\lixo.cpp|30|macro "NS_DECLARE_STATIC_IID_ACCESSOR"
passed 11 arguments, but takes just 1|
c:\projects\webconnect\lixo.cpp|31|error: ISO C++ forbids declaration of
`NS_DECLARE_STATIC_IID_ACCESSOR' with no type|
c:\projects\webconnect\lixo.cpp|31|error: expected `;' before '}' token|
c:\projects\webconnect\lixo.cpp|31|error: expected `;' before '}' token|
||=== Build finished: 4 errors, 0 warnings ===|


Thank you for your attention,
Mauricio.



-- 
Mauricio Gomes
Pensar Digital
55-11-9698-1683 (Brazil - mobile)