I don't think the "C" compiler supports anything but extern, so your only
option is to extern "C" your C++ variable. The SDK headers conditionally
#define EXTERN_C, so you can...

// SomeCommon.h
EXTERN_C INT g_nValue;

// SomeCpp.cpp
#include "Some.h"
EXTERN_C INT g_nValue = 0;

// SomeC.c
#include "Some.h"

VOID _cdecl SomeFunc(VOID)
{
   INT n = g_nValue;
}

"Bonj" <benjtaylor at hotpop d0t com> wrote...

You cannot link a file compiled with a C++ compiler to another compiled
with a C compiler, using a C linker.  That's likely not going to work.
What you need is

(a) Declare the symbol in the C++ file as 'extern "C"' when compiling
(b) Link both together using a C++ linker

The reason is simple: the C language is older and when the object code
and linking specifications were developed, there was no C++, so most of
the C compilers/linkers still follow those quarter-a-century old guide-
lines.  Besides, there is a bit of that "I've been here before you, I
am better than you, and I am not going to give you the second thought"
attitude coming from the C camp.  No big deal, C++ programmers just work
around all that.

V