va_arg doesn't work correctly in functions which have been inlined.  Either
the compiler should reject functions using va_arg as candidates for
inlining, or the implementation of va_arg should be fixed to work correctly.

The example below has been tested at warning level 4 with the /Wall compiler
switch.  Warning 4711 has been left enabled so that you can see when the
function has been automatically inlined.

   // Vararg.cpp : Defines the entry point for the console application.
   //
   #pragma warning(disable : 4710)

   #pragma warning(push)
   #pragma warning(disable : 4217 4619 4668 4820)
   #include <iostream>
   #include <cstdarg>
   #pragma warning(pop)

   //#pragma auto_inline(off)
   int TestVararg(int intFirst, int /*intSecond*/)
   {
       va_list argList;
       va_start(argList, intFirst);
       int arrInt = va_arg(argList, int);
       va_end(argList);
       return arrInt;
   }

   int main()
   {
       std::cout << TestVararg(1, 123456789) << std::endl;
       return 0;
   }

   #pragma warning(disable : 4514)

The example works correctly in Debug mode (which never auto-inlines
functions), and in Release mode when #pragma auto_inline(off) is used, but
returns the wrong value when the function is inlined.  I have tested it in
Visual C++ .NET 2003, but not in VC++ .NET 2002 (MOD XP broke my
installation and won't uninstall or reinstall no matter what I do) or VC++ 6
because I don't have it installed.

Regards,
Aaron Queenan.