Generate code for variable size bus signal

I have a model that has bus signals as input and output. If I set the port dimensions of the input and output to 5, I get the following interface in generated C code.

// External inputs (root inport signals with auto storage)

typedef struct {

InputBusType InputBus[5]; // '<Root>/InputBus'

} ExtU_MyModel_T;

// External outputs (root outports fed by signals with auto storage)

typedef struct {

OutputBusType OutputBus[5]; // '<Root>/OutputBus'

} ExtY_MyModel_T;

// Root inport: '<Root>/InputBus' set method

void setInput(InputBusType localArgInput[5]);

// model step function

void step();

// Root outport: '<Root>/OutputBus' get method

OutputBusType getOutput() const;

How can I set the bus signals to have variable sized dimensions? I would like to get the following C code instead.

// External inputs (root inport signals with auto storage)

typedef struct {

InputBusType InputBus[]; // '<Root>/InputBus'

int InputBusSize;

} ExtU_MyModel_T;

// External outputs (root outports fed by signals with auto storage)

typedef struct {

OutputBusType OutputBus[]; // '<Root>/OutputBus'

int OutputBusSize;

} ExtY_MyModel_T;

// Root inport: '<Root>/InputBus' set method

void setInput(InputBusType localArgInput[], int size);

// model step function

void step();

// Root outport: '<Root>/OutputBus' get method

void getOutput(OutputBusType* output, int size);

I have managed to get the C code I want if I set the type of the signals to Integers, but it does not work with bus types.

Also I know that you can define variable size for the bus elements, but there is no option to do that for the parent bus object.

Here are some stuff that I have read and tried, but none of them helped me produce the C code I want.

https://se.mathworks.com/matlabcentral/answers/176736-matlab-coder-variable-size-matrix-input

https://se.mathworks.com/matlabcentral/answers/101846-how-can-i-create-an-output-bus-with-variable-size-elements-using-a-structure-in-embedded-matlab

https://se.mathworks.com/matlabcentral/answers/290490-variable-sized-array-of-bus-signals

https://se.mathworks.com/help/simulink/ug/simulink-models-using-variable-size-signals-demos-modeling-features-variable-size-signals-or-type-varsizedemos-.html#br7dlm_-1

https://se.mathworks.com/help/simulink/ug/defining-variable-size-data-for-code-generation.html

https://se.mathworks.com/help/xpc/ug/tuning-block-parameters-and-model-parameters.html

I will be grateful for any help about this!

Regards

Martin Ekerstedt