How to inline external C-Code with legacy code tool?

I am calling external C functions via an S-function. The S-function is created using Legacy Code Tool (LCT), which also generates a TLC file.

Despite the TLC file, the external C code is not inlined when generating C code. What is the correct workflow to inline the external C code?

Answer 1

[MathWorks Support Team]

You can use #ifdef MATLAB_MEX_FILE pragma in your external header file to control compiler function inline process

Assume we would inline external code: myfoo.c, myfoo.h

Step 1: Add pragma to your external header file myfoo.h e.g.

#ifdef MATLAB_MEX_FILE  // This is for simulation only, we create empty functions

void myfoo(uint32_t instance, uint8_t channel);

#else                   // Code generation

#include "a.h"
#include "b.h"

static inline void myfoo(uint32_t instance, uint8_t channel)
{
    ...
}

#endif    

Step 2: The myfoo.c contains this

#include "myfoo.h"

#ifdef MATLAB_MEX_FILE  // This is for simulation only, we create empty functions

void myfoo(uint32_t instance, uint8_t channel
{
}

#endif

In the model step function, the external code will be inlined after compiling code from your Simulink model.