Calling function from dll within C-MEX

Hi All,

I got this error when I'm trying to compile the mult.cpp function, which calls the showmsg():

>> mex mult.cpp dll2.lib

mult.obj : error LNK2019: unresolved external symbol showmsg referenced in function mdlOutputs mult.mexw64 : fatal error LNK1120: 1 unresolved externals

I compiled the dll in VS2010 (C++). The header:

      #ifdef __cplusplus
        extern "C" {
      #endif

    namespace dllnamesp
    {
      class dllclass
      {
      public:
        static __declspec(dllexport) void showmsg();
      };
    }
    #ifdef __cplusplus
    }
    #endif
------------------------------------------------
*The C++ file:*
#include <iostream>
using namespace std;
#include "printer.h"

#ifdef __cplusplus
extern "C" {
#endif

namespace dllnamesp
{
  void dllclass::showmsg()
  {
    cout << "alma\n";
  }

}

#ifdef __cplusplus
}
#endif

In the mult.cpp:

• -I included the header: #include "printer.h"
• -I declared the function: void __cdecl showmsg();
• -I called the function in: static void mdlOutputs(SimStruct *S, int_T tid) { showmsg(); }

The header,lib and dll are in the same folder with the C-MEX function. What Am I doing wrong?

Regards,

Daniel

Answer 1

[Kaustubha Govind]

If you're using 64-bit MATLAB, you might need to make sure that the DLL is also 64-bit - I believe the default configuration for Visual Studio is a 32-bit target.