C++ 10.1.011 inline template not being instantiated

[max2131]

Hi,

I have found an issue with template instantiation of inlined functions.

Here is the code that uses MFC42:

#include
#include // MFC core and standard #include // MFC extensions
#include
#include // MFC support for #include
#include

int main() {

CArray SrcArray;

return 0;
}

When it is linked these unresolved symbols are printed:

tt.obj : error LNK2019: unresolved external symbol "void __stdcall DestructElements(class CString *,int)" (??$DestructElements@VCString@@@@YGXPAVCString@@H@Z) referenced in function "public: virtual void * __thiscall CArray::`scalar deleting destructor'(unsigned int)" (??_G?$CArray@VCString@@V1@@@UAEPAXI@Z)
tt.obj : error LNK2019: unresolved external symbol "void __stdcall ConstructElements(class CString *,int)" (??$ConstructElements@VCString@@@@YGXPAVCString@@H@Z) referenced in function "public: virtual void __thiscall CArray::Serialize(class CArchive &)" (?Serialize@?$CArray@VCString@@V1@@@UAEXAAVCArchive@@@Z)
tt.obj : error LNK2019: unresolved external symbol "void __stdcall SerializeElements(class CArchive &,class CString *,int)" (??$SerializeElements@VCString@@@@YGXAAVCArchive@@PAVCString@@H@Z) referenced in function "public: virtual void __thiscall CArray::Serialize(class CArchive &)" (?Serialize@?$CArray@VCString@@V1@@@UAEXAAVCArchive@@@Z)

All of these are inlined functions defined in afxtempl.h and used by CArray constructor and destructor (and other members as well).

Using /Od or even /Qinline-forceinline does not help.
If, at the same time, int or CStringData is used instead of CString in the template specialization, everything links just fine.

So finally I figured out that commenting out these lines in afxtempl.h:

template<> void AFXAPI ConstructElements (CString* pElements, INT_PTR nCount);
template<> void AFXAPI DestructElements (CString* pElements, INT_PTR nCount);
template<> void AFXAPI CopyElements (CString* pDest, const CString* pSrc, INT_PTR nCount);
template<> void AFXAPI SerializeElements (CArchive& ar, CString* pElements, INT_PTR nCount);

leads to them being properly inlined. This seems an Intel compiler problem because /Qms2 (full MS C++ compatibility) is used.

[TimP]

Does this problem depend on which version of CL or link you have installed? It seems you would have to specify those in order to reproduce the problem (unless a bug was corrected in the current ICL):

$ icl /Qms2 max.cpp
Intel C++ Compiler for applications running on IA-32, Version 10.1 Build 2
0071116 Package ID: w_cc_p_10.1.013
Copyright (C) 1985-2007 Intel Corporation. All rights reserved.

max.cpp
WINVER not defined. Defaulting to 0x0600 (Windows Vista)
Microsoft Incremental Linker Version 9.00.20706.01
Copyright (C) Microsoft Corporation. All rights reserved.

-out:max.exe
max.obj

[max2131]

Hi,

Thank you for the reply.

Here is the info:

W:>max.cmd
Intel C++ Compiler for applications running on IA-32, Version 10.1 Build 20070913 Package ID: w_cc_p_10.1.011
Copyright (C) 1985-2007 Intel Corporation. All rights reserved.

max.cpp
Microsoft Incremental Linker Version 8.00.50727.42
Copyright (C) Microsoft Corporation. All rights reserved.

-out:max.exe
max.obj
max.obj : error LNK2019: unresolved external symbol "void __stdcall DestructElements(class CString *,int)" (??$DestructElements@VCString@@@@YGXPAVCString@@H@Z) referenced in function "public: virtual void * __thiscall CArray::`scalar deleting destructor'(unsigned int)" (??_G?$CArray@VCString@@V1@@@UAEPAXI@Z)
max.obj : error LNK2019: unresolved external symbol "void __stdcall ConstructElements(class CString *,int)" (??$ConstructElements@VCString@@@@YGXPAVCString@@H@Z) referenced in function "public: virtual void __thiscall CArray::Serialize(class CArchive &)" (?Serialize@?$CArray@VCString@@V1@@@UAEXAAVCArchive@@@Z)
max.obj : error LNK2019: unresolved external symbol "void __stdcall SerializeElements(class CArchive &,class CString *,int)" (??$SerializeElements@VCString@@@@YGXAAVCArchive@@PAVCString@@H@Z) referenced in function "public: virtual void __thiscall CArray::Serialize(class CArchive &)" (?Serialize@?$CArray@VCString@@V1@@@UAEXAAVCArchive@@@Z)
max.exe : fatal error LNK1120: 3 unresolved externals

On Visual Studio 8 this problem does not reproduce because these inlines are marked as deprecated in afxtempl.h and are not actually used.

My MFC version is (from afxver_.h):

#define _MFC_VER 0x0600 // Microsoft Foundation Classes version 6.00

while Visual Studio 8 version is (from afxver_.h):

#define _MFC_VER 0x0800 // Microsoft Foundation Classes version 8.00

Best regards.

[TimP]

VS6 specifically is no longer supported since ICL 10.0. ICL 9.1 had an option to install with VS6. In that case there is no compatibility with more recent versions. For a long shot, you could try editing the VC flag in the ICL installation file ICL.CFG, in case it is set for a more recent VC version.

[max2131]

We use quite modern cl.exe (14.00.50727.42) and link.exe (8.00.50727.42), and they handle old MFC version 6 headers and libraries just fine. So, given this case, icl.exe seems to have a compatibility defect - which may manifest itself with some other template based library, possibly not from Microsoft.

[Judith_W_Intel]

What does the file"max.cmd" contain?

[max2131]

Hi,

the file max.cmd contains just

icl /Qms2 max.cpp

while max.cpp has

#include
#include // MFC core and standard #include // MFC extensions
#include
#include // MFC support for #include
#include

int main() {

CArray SrcArray;

return 0;
}

To reproduce the issue use MFC from Visual Studio 6.