Visual C++ 2019 link error: lld-link: : error : undefined symbol: declspec(dllimport) public: static void cdecl ATL::CSimpleStringT<wchar_t, 1>

hyperandey 21

I am building release version of OpenMP C++ codes with Visual Studio 2019. The debug version ran pretty well but the release version ended up with some strange linker error: "1>lld-link: : error : undefined symbol: __declspec(dllimport) public: static void __cdecl ATL::CSimpleStringT<wchar_t, 1>::CopyChars(wchar_t *, unsigned __int64, wchar_t const *, int)" I am using Intel one API DPC C++/C++ Compiler with support of OpenMP 5.x. I use some CString, TCHAR inside the codes but I do not think those caused the problem as I did a simple mockup OpenMP program with CString and TCHAR under same project configuration properties setting. The compilation and link were fine. I really don't know what caused this link error. My old program without OpenMP was built perfectly without problem. The mock up program I ran with successful built-up is as follows: Can someone give me a hint on how to resolve this linker error? Thanks.

Tianyu Sun-MSFT 29,446 Reputation points Microsoft Vendor

2023-04-12T09:56:26.8766667+00:00

Hello @hyperandey ,

Welcome to Microsoft Q&A forum.

Maybe there’s something wrong with the view of the code that you shared, I don’t see the related code snippets. Could you please share us the code snippets/sample program again for checking?
RLWA32 43,381 Reputation points

2023-04-12T10:57:23.4066667+00:00

@Sheng Jiang 蒋晟 had the following observation about a similar issue at https://learn.microsoft.com/en-us/answers/questions/1113788/unresolved-external-symbol "MFC's CString became a template in VC7 so there is nothing to link to. You have some old libs that need to recompiled using the same MFC version you are using." ATL and MFC share the CString class so this might also be applicable here.

hyperandey 21

Sorry for missing my code snippets. I did the following mockup codes with some simple OpenMP and CString as well as conversion among TCHAR, wstring, and CString. It was built pretty well under release version but my targeted project is not working. It is quite strange.


#include <iostream>
#include <vector>
#include <omp.h>
#include <atlstr.h>
#include <fstream>
using namespace std;

vector<int> test;

void func(int i)
{
    i++;

    int tmp = i;
#pragma omp for 
    for (int k = 0; k < 10; k++)
    {
    #pragma omp atomic update
        test[k] += (tmp + k);
    }

}

int main()
{
    int sum = 0;
    int i = 0;
    
    CString fileName;

    fileName = _T("Shapedis.dxf");
    const TCHAR* NameFile = (LPCTSTR)fileName;
    wstring namestr(NameFile);
    wofstream FShapeDis(namestr, ios::out);

    FShapeDis << L"0" << endl;

    FShapeDis.close();

    test.resize(10);

    for (int n = 0; n < 10; n++)
        test[n] = 0;


#pragma omp parallel shared(sum, test) firstprivate(i) num_threads(2)
    {
        do {
            #pragma omp atomic update
            sum += 1;        

            func(i);
            cout << "test[0] is " << test[0] << endl;

            i += 1;

        } while (i < 10);
    }

    cout << "Sum = " << sum << endl;

    cout << "Test array values are  \n";
    for (int j = 0; j < 10; j++)
        cout << test[j] << " ";

    cout << "Hello World!\n";
}

Tianyu Sun-MSFT 29,446 Reputation points Microsoft Vendor

2023-04-18T06:48:03.3633333+00:00

Hi @hyperandey ,

Thanks for sharing the code snippets.

I agree with @RLWA32 , have you considered the suggestion shared by @RLWA32 ?

Besides, are you using the latest version of VS 2019? Is it possible for you to try to test this on VS 2022?

Regards,

Tianyu

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Visual C++ 2019 link error: lld-link: : error : undefined symbol: __declspec(dllimport) public: static void __cdecl ATL::CSimpleStringT<wchar_t, 1>

Visual C++ 2019 link error: lld-link: : error : undefined symbol: declspec(dllimport) public: static void cdecl ATL::CSimpleStringT<wchar_t, 1>