Validate is there is an s-function in the Simulink model with embedded coder

We have 2 simulink models that we convert to C++. In one simulink model we have a non-inlineable S-function. The S-function in C++ performs dynamic allocation therefore we need to check whether or not the dynamic allocation at startup has been succesful. We do something like this

for (int i = 0; i < rtM->Sizes.numSFcns; i++) {
    SimStruct* rts = rtM->childSfunctions[i];
    if (ssGetErrorStatus(rts) != (NULL)) {
        error = true;
        
        //TODO : Implement strncpy_s
        strncpy(infoMsg, ssGetErrorStatus(rts), 100);
        }
        }

However, in the 2nd model, we don't have an S-function and the above code fails. Is there a way to check whether or not there's an S-function in the Simulink model either using TLC or other options in embedded coder?

we cannot use the regular initialize C++ function as the function has no return arguments and we cannot know whether or not it has failed.

Answer 1

[Ayush]

Hi @Benjamin Couillard,

Yes, there is a way to check whether a Simulink model contains an S-function or not. Here's one possible approach using your TLC file:

1. Set a boolean variable `containsSFunction` to `false` initially.

2. Get the root SimStruct pointer using `ssGetRootSS(S)`.

3. Start a loop to traverse through the model hierarchy:

- Check if the current SimStruct has any registered S-function parameters using `ssGetNumSFcnParams(S)`.

- If the count of registered S-function parameters is greater than zero, set `containsSFunction` to `true` and break out of the loop.

- Get the parent SimStruct using `ssGetParentSS(S)`.

- Repeat the loop until reaching the top-level SimStruct or until `S` becomes `NULL`.

4. After the loop, check the value of `containsSFunction`: which can tell whether model has a S-function or not.

This algorithm traverses the model hierarchy starting from the root SimStruct and checks if any S-function parameters are registered at each level. If at least one S-function parameter is found, it indicates the presence of S-function blocks in the model.

To read more about above functions kindly view the following documentations:

Get the root of a SimStruct hierarchy - MATLAB (mathworks.com)

Get the number of parameters that an S-Function block expects - MATLAB (mathworks.com)

Get the parent of a SimStruct - MATLAB (mathworks.com)

Hope this helps!