ssPrintf for C-Mex S-Function

I would like to debug my S-Function using ssPrintf, but if the ssPrintf is between #ifndef MATLAB_MEX_FILE and #endif, there is no message printing out. Even I use mexPrintf or printf.

    static void mdlOutputs(SimStruct *S, int_T tid)
    {
      ssPrintf("message1\n");

    #ifndef MATLAB_MEX_FILE
      ssPrintf("message2\n");
    #endif

      ssPrintf("message3\n");
    }

-------------------------

Output in Command Windows:

message1

message3

-------------------------

Thanks!!!

Answer 1

[Kaustubha Govind]

When the S-function is compiled as a MEX-function, the symbol MATLAB_MEX_FILE is always defined, so that line is effectively getting eliminated by the C pre-processor. MATLAB_MEX_FILE is undefined only when generating code using Simulink Coder (formerly Real-Time Workshop), as a non-inlined S-function - ie, there is not TLC file associated with that S-function.