[MinGW-dvlpr] Distinguishing MSVCT dll version in headers

[Danny S. <dan...@cl...>]

Any ideas on a macro name and constants for distinguishing different
runtime libraries (msvcrt vs msvcr70 bs msvcr71);

I have some structures & function prototypes to be added to headers
but would like to guard with something like:

Set default in _mingw.h

#ifndef __MSVCRT_VER__
# define __MSVCRT_VER__ 0x0600
#endif

then in, eg,  io.h

/* These require newer versions of msvcrt.dll (6.1 or higher). */
#if __MSVCRT_VER__ >= 0x0601
/*  dont confuse this with _finddatai64
struct __finddata64_t {
        unsigned    attrib;
        __time64_t  time_create;
        __time64_t  time_access;
        __time64_t  time_write;
        _fsize_t    size;
         char       name[260];
};

intptr_t __cdecl _findfirst64(const char*, struct __finddata64_t*);

etc.

Question is, should we

(1) use the 0x0601 MAKEWORD type of constant to
have the high byte contain the major version and low byte the minor,
like _WIN32_IE and friends

or

do something simpler like
#if __MSVCRT_VER__ >= 61

or

3) explicitly use major and minor versions in tests.

#if (__MSVCRT_VER_MAJOR__ > 6 \
     || ( __MSVCRT_VER_MAJOR__ == 6 \
          && __MSVCRT_VER_MINOR__ >= 1)


I prefer 1 or 2 since it makes easy for user to overide the default.

Danny