which gcc distro supports __declspec(dllexport) _cdecl and _stdcall - c++

Question

I am trying to get started using mingw (MinGW-w64) and eclipse after working in C++Builder for a long time. I'm very confused.
My work mostly revolves around a vendor supplied API which is MSVC-centric. It consists of 3 header files and a couple of libs. I was able to use their headers unchanged in C++Builder but am running into lots of problems with g++.
#define GX_WRAPPER_FUNC __declspec(dllexport)
#define GX_STANDARD_FUNC
#define GX_WRAPPER_CALL _cdecl
#define GX_STANDARD_CALL _stdcall
#define GX_OBJECT_PTR void*
#define GX_VAR
#define GX_CONST const
#define GX_VOID void
#define GX_LONG long
#define GX_DOUBLE double
#define GX_HANDLE long
#define GX_LONG_PTR long*
#define GX_DOUBLE_PTR double*
#define GX_HANDLE_PTR long*
#define GX_ASTR_PTR char*
#define GX_WSTR_PTR wchar_t*
#if defined(GEO_UTF8)
#define GX_STR_PTR GX_ASTR_PTR
#elif defined( _UNICODE)
#define GX_STR_PTR GX_WSTR_PTR
#else
#define GX_STR_PTR GX_ASTR_PTR
#endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
/*---------------- Copy_3DN[_public] ----------------*/
GX_WRAPPER_FUNC GX_LONG GX_WRAPPER_CALL
Copy_3DN(GX_VAR GX_OBJECT_PTR,
GX_CONST GX_HANDLE_PTR,
GX_CONST GX_HANDLE_PTR);
GX_STANDARD_FUNC GX_LONG GX_STANDARD_CALL
Std_Copy_3DN(GX_VAR GX_OBJECT_PTR,
GX_CONST GX_HANDLE_PTR,
GX_CONST GX_HANDLE_PTR);
...hundreds more like this
This yields a whole bunch of "expected initializer before " errors.
I've had some success by redefining the first 4 defines like this:
#ifdef __GNUC__
#define GX_WRAPPER_FUNC __attribute__ ((dllexport))
#define GX_STANDARD_FUNC
#define GX_WRAPPER_CALL
#define GX_STANDARD_CALL
#else
#define GX_WRAPPER_FUNC __declspec(dllexport)
#define GX_STANDARD_FUNC
#define GX_WRAPPER_CALL _cdecl
#define GX_STANDARD_CALL _stdcall
#endif
but it barfs later on when it encounters
GX_WRAPPER_FUNC GX_LONG GX_WRAPPER_CALL
RegisterResourceTracking_GEO(GX_VAR GX_OBJECT_PTR,
GX_CONST GX_LONG_PTR,
GX_OBJECT_PTR,
void (_stdcall *param3)(void*));
I would really like to use these headers WITHOUT editing them, and I've seen some references that suggest the correct choice of gcc distro might support this syntax, but I've tried a number already with no luck. I've tried both the i686 and x86-64 variants of MinGW-w64 and Nuwen and TDM. I'm not concerned with cross platform issues as the host app is Windows only anyways, and for my own stubborn reasons I don't want to give up and switch to MSVC.
So, is there a gcc distro which will support this syntax? If not, what is the path of least resistance?
cheers

Answer 1

As a workaround, you can expand your set of macro definitions to cover the keywords gcc doesn't recognize:
#ifdef __GNUC__
#define _cdecl __attribute__((cdecl))
#define __cdecl __attribute__((cdecl))
#define _stdcall __attribute__((stdcall))
#define __stdcall __attribute__((stdcall))
#define GX_WRAPPER_FUNC __attribute__ ((dllexport))
#else
#define GX_WRAPPER_FUNC __declspec(dllexport)
#endif
As a bonus, those make the original definitions here work:
#define GX_STANDARD_FUNC
#define GX_WRAPPER_CALL _cdecl
#define GX_STANDARD_CALL _stdcall
(FWIW, note that this is possible because most MSVC extensions are new simple keywords, from the space of identifiers reserved to the implementation. gcc's multi-token __attribute__(()) magic makes mapping in the reverse direction completely impossible. So any time you write code using gcc non-portable features, hide them behind macros.)