C S-Function doesn't work anymore on different Matlab/compiler. Probably pointer problem.

Hello everyone

I have a C S-Function that used to work on R2013b with Visual Studio Pro 2011 as compiler. Now with R2016b and MinGW64 as compiler, it crashes Matlab completely.

In mdlOutputs, I have removed a switch-case structure, which just repeats the problem with different parameters.

I can't find the problem. If you need more information, please ask.

/* specify the name of your S-Function */
#define S_FUNCTION_NAME defectiveFunction
#define S_FUNCTION_LEVEL 2

/*
 * Need to include simstruc.h for the definition of the SimStruct and
 * its associated macro definitions. Need math.h for exp-function.
 */
#include "tmwtypes.h"
#include "simstruc.h"
#include <math.h>

#define BLI_A        (*mxGetPr(ssGetSFcnParam(S, 0)))
#define BLI_B        (*mxGetPr(ssGetSFcnParam(S, 1)))
#define BLI_C        (*mxGetPr(ssGetSFcnParam(S, 2)))
#define BLI_D        (*mxGetPr(ssGetSFcnParam(S, 3)))
#define BLI_ALPHA    (*mxGetPr(ssGetSFcnParam(S, 4)))
#define BLI_REFL     (*mxGetPr(ssGetSFcnParam(S, 5)))
#define SHAD_TYPE    ((int)(*mxGetPr(ssGetSFcnParam(S, 6))+0.5)) // Removed switch-case
#define TYPE_GLAZING ((int)(*mxGetPr(ssGetSFcnParam(S, 7))+0.5)) // Removed switch-case
#define TAU_SHAD     (*mxGetPr(ssGetSFcnParam(S, 8)))

#define R_SHAD       (*u[0])
#define ZEN_ANGLE    (*u[1])

static void mdlInitializeSizes(SimStruct *S)
{
    ssSetNumSFcnParams(S, 9);  /* Number of expected parameters */
    if (ssGetNumSFcnParams(S) != ssGetSFcnParamsCount(S))
    {
        /* Return if number of expected != number of actual parameters */
        return;
    }

      if (!ssSetNumInputPorts(S, 1))   /* number of inputs    */
      {
          return;
      }
      ssSetInputPortWidth(S, 0, 2);

      if (!ssSetNumOutputPorts(S, 1))      /* number of outputs   */
      {
          return;
      }
      ssSetOutputPortWidth(S, 0, 4);

      ssSetNumSampleTimes(S, 1);  /* number of sample times */
  }

static void mdlInitializeSampleTimes(SimStruct *S)
{
    ssSetSampleTime(S, 0, 0.0);
    ssSetOffsetTime(S, 0, 0.0);
}

static void mdlOutputs(SimStruct *S, int_T tid)
{
    InputRealPtrsType u = ssGetInputPortRealSignalPtrs(S, 0);
    real_T *y = ssGetOutputPortRealSignal(S, 0);

      int shad_type = SHAD_TYPE;
      double r_shad = R_SHAD;
      int type_glazing = TYPE_GLAZING;
      double tau_shad = TAU_SHAD;
      double bli_a = BLI_A;
      double bli_b = BLI_B;
      double bli_c = BLI_C;
      double bli_d = BLI_D;
      double bli_refl = BLI_REFL;
      #ifdef PI
          double pi = PI;
      #else
          double pi = 3.14159;
      #endif
      double zen_angle = ZEN_ANGLE*pi/180.0;
      double bli_alpha = BLI_ALPHA*pi/180.0;
      double cos_a = cos(bli_alpha);
      double sin_a = sin(bli_alpha);  
      double X_shad, X_shad_a, X_shad_b, F_Shad_dir, bli_r, a2, d2, f_para, e_para, gamma, F_Shad_dfu, refl_alpha, D_refl, f_g;
      double el_h=(pi/2.0-zen_angle);
      double epsilon=atan(bli_b/bli_c);
      double A_corr=1.3; //weight factor empirically evaluated with task34 empa measurments

      /* Removed switch-case */
          //'Exterior Screen' 
          y[0]=1.0-r_shad*(1.0-tau_shad);  // THIS CRASHES
          y[1]=1.0-r_shad*(1.0-tau_shad);
          y[2]=1.0;                        // THIS WORKS
          y[3]=1.0;
      /* Removed switch-case */
  }

static void mdlTerminate(SimStruct *S)
{
}

#ifdef  MATLAB_MEX_FILE    /* Is this file being compiled as a MEX-file? */
#include "simulink.c"      /* MEX-file interface mechanism */
#else
#include "cg_sfun.h"       /* Code generation registration function */
#endif

[Suze Zhang]

Can you post the crash log?

[Manu]

• Crash log attached because the formatting was horrible when posted directly.
• To avoid confusion: The function's current real name is venetianMod.
• The real function is a bit different from the posted one, but the problem is the same.

Answer 1

[Manu]

Solved. External problem found and fixed.