Problem statically linking MFC libraries

Question

I have a Visual Studio 6 workspace I'm trying to convert to a Visual Studio 2008 solution. The output of said solution is a .dll. It has to be a .dll and it needs to statically link MFC as I can't redistribute MFC to existing customers.

The solution consists of three projects, say A, B, C. C is the Active Project, outputs the .dll and depends on B. B outputs a .lib and depends on A. A outputs a .lib.

In the General configuration properties I have A and B set to Static Library (.lib) and C set to Dynamic Library (.dll). All three projects are set to "Use MFC in a Static Library." Also, all three projects are set to "Multi-threaded" for Runtime Library and none of them have _AFXDLL defined.

Everything builds correctly up until the final linking stage where I see this:

1>nafxcw.lib(wincore.obj) : error LNK2005: _IsPlatformNT already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _InitMultipleMonitorStubs already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xGetSystemMetrics@4 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xMonitorFromPoint@12 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xMonitorFromRect@8 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xMonitorFromWindow@8 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xGetMonitorInfo@8 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xEnumDisplayMonitors@16 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xEnumDisplayDevices@16 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnGetSystemMetrics already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnMonitorFromWindow already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnMonitorFromRect already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnMonitorFromPoint already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnGetMonitorInfo already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnEnumDisplayMonitors already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnEnumDisplayDevices already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_fMultiMonInitDone already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_fMultimonPlatformNT already defined in A.lib(Globals.obj)
1>nafxcw.lib(viewprnt.obj) : error LNK2005: "public: virtual int __thiscall CPrintingDialog::OnInitDialog(void)" (?OnInitDialog@CPrintingDialog@@UAEHXZ) already defined in B.lib(ImagePropertiesDlg.obj)
1>nafxcw.lib(viewprnt.obj) : error LNK2005: "public: __thiscall CPrintingDialog::CPrintingDialog(class CWnd *)" (??0CPrintingDialog@@QAE@PAVCWnd@@@Z) already defined in B.lib(ImagePropertiesDlg.obj)
1>nafxcw.lib(viewprnt.obj) : error LNK2005: "public: virtual void __thiscall CPrintingDialog::OnCancel(void)" (?OnCancel@CPrintingDialog@@UAEXXZ) already defined in B.lib(ImagePropertiesDlg.obj)

I've Googled the problem to death and seen other people with a similarish issue, but can't seem to solve it. I tried adding nafxcw.lib to the Ignored libraries for C, but that turned this batch of linker errors into 1500+ unresolved symbol errors. I can get it to compile/link if I make it dynamically link MFC, but like I said, I need it to statically link. I feel like I'm missing something rather simple but can't seem to wrap my head around it. Any and all random thoughts and ideas will be greatly appreciated.

Answer 1

When you tried ignoring the nafxcw library, did you add it back in to try to force a link order as suggested by this KB article? While your problem isn't an exact fit it may be related. Perhaps things could be resolved by monkeying with the link order.

Answer 2

As is often the case, the solution turned out to be so mundane and obvious, I'm still kicking myself for banging my head on it for so long.

Basically, project A referenced above was not a project I directly pulled from the old VS6 workspace, but rather a project that had previously been converted by another team for use in another application. I assumed it was functionally equivalent to the original one, but that is very much not the case. These linking errors are actual, valid multiply defined linking errors. When I started digging in, I found that the first batch of errors was from including multimon.h in project A (something I don't even need, just removed it) and the second batch is from a class that is actually defined in both A and B.

Like I said, I'm still groaning over here, but at least I should be able to fix my problem now. Thanks for the help and always remember to NEVER assume ANYTHING.