How to force Embedded coder to use a specific struct name (instead of struct_xxxxxx) for system object parameters?

I have a custom System object that uses a configuration struct returned by a helper function:

classdef Demo_setpoint_adjuster < matlab.System
    properties
        config = Demo.getconfig; 
    end
    methods
        function obj = Demo_setpoint_adjuster()
            % Optionally initialize config/state here if needed
        end
    end
    methods(Access = protected)
        function [adjusted_setpoint] = stepImpl(obj, setpoint)
            % Default passthrough implementation
            % Assign outputs
            adjusted_setpoint = setpoint * obj.config.gain;
            % TODO implement
        end
        function num = getNumInputsImpl(~), num = 1; end
        function varargout = getNumOutputsImpl(~), varargout = {1, []}; end
        function varargout = getOutputSizeImpl(~), varargout = {1}; end
        function varargout = getOutputDataTypeImpl(~), varargout = {'double'}; end
        function varargout = isOutputComplexImpl(~), varargout = {false}; end
        function varargout = isOutputFixedSizeImpl(~), varargout = {true}; end
    end
end

My getconfig function looks like this:

function cfg = getconfig(varargin)
cfg = Simulink.Bus.createMATLABStruct('DEMO_config_def');
cfg.gain = 10;
cfg.offset = 1e-13;
coder.cstructname(cfg, 'my_struct');
end % end of main function getconfig

When I generate code with Embedded coder, the header file defines the parameter type as something like:

typedef struct {
real_T gain;
real_T offset;
} struct_6h72eH5WFuEIyQr5YrdGuB;

Instead of my desired:

typedef struct {
real_T gain;
real_T offset;
} my_struct;

Even though I use coder.cstructname, Simulink still generates the anonymous struct_xxxxxx

Question:

When using a System object parameter inside a simulink model, how can i ensure embedded coder generates a struct with a specific typedef name (e.g., my_struct)? Is the recommended approach to use Simulink.Bus/Simulink.Parameter, or can coder.cstructname be applied directly in this workflow?

[dpb]

Try the alternate syntax to also specify the header file that defines the C struct

There is <an example if it is a global stuct>

Answer 1

[Goutam]

Hi Manoj,

Embedded Coder ignores coder.cstructname for tunable System-object properties, so the easiest supported solution is to model the structure as a Simulink.Bus / Simulink.Parameter and let the bus name (or its alias) become the typedef.

If the structure is compile-time constant, you can keep everything in MATLAB and coder.cstructname will work.

Here is a workaround that you may try :

1. Use a Bus-based workflow

• Create a Simulink.Bus object DEMO_config_def in the base workspace that matches the fields gain / offset.
• In the model, use a Simulink.Parameter whose DataType is 'Bus: DEMO_config_def'.
• In the Code Mappings editor (or via set_param(model,'GenerateBusDefinition','on')) set “Generate typedef for bus objects” to On and pick the desired name (‘my_struct’, or keep the bus name itself).

2. Define the structure as a constant property so that coder.cstructname can be applied automatically

• coder.cstructname is honored only when the structure is treated as a compile-time constant.
• If you declare the System-object property as Constant (or as a persistent coder.const) you can force that:

classdef Demo_setpoint_adjuster < matlab.System
    properties(Constant)
       config = coder.const(Demo.getconfig)
    end
...
end

and in getconfig keep

coder.cstructname(cfg,'my_struct');

3. Use a data-type alias

• If the randomly generated name works fine but you'd like something more readable, you can create a Simulink.AliasType in the Data Dictionary or base workspace to give it a clearer alias

T = Simulink.AliasType;
T.BaseType = 'struct_6h72eH5WFuEIyQr5YrdGuB';   % generated name
my_struct_typ = 'my_struct';
assignin('base', my_struct_typ, T);

• Set the parameter datatype to this alias in Code Mappings.
• Embedded Coder will still generate the anonymous struct, but immediately after it you will see

 typedef struct_6h72eH5WFuEIyQr5YrdGuB my_struct;

Kindly refer to the documentation links below for reference:

• https://www.mathworks.com/help/simulink/slref/simulink.bus.html
• https://www.mathworks.com/help/coder/ref/coder.cstructname.html
• https://www.mathworks.com/help/coder/ref/coder.const.html
• https://www.mathworks.com/help/simulink/slref/simulink.aliastype.html

Hope this helps.

Regards,

Goutam