I have a parameter that is used only inside of a variant subsystem. How can I make sure that in the generated code this parameter is only defined if the variant is active?

I have a model (call it "Parent") that contains a model reference ("Child"). Inside of "Child", there is a variant subsystem, and inside one of the variants (and not the others), a parameter called "myParam" (configured as a Simulink.Parameter object) is used. I want to generate code from "Parent", but I only want "myParam" to be defined if it is needed (i.e. its variant is the active one). Note that this actually occurs many times in my system, so this behavior is important for memory usage in the generated code.

Now, inside the generated code for "Child", the code for each variant is located is located inside "#if...#endif" statements that ensure that the code is only run if the variant is active, which is what I want. But, the definition of "myParam" is located in the code for "Parent" and it does not have these #if preprocessor guards.

How can I generate code so that "myParam" is only defined if it is used? Can I generate code so that the definition is inside of a preprocessor "#if...#endif" guard?

Answer 1

[MathWorks Support Team]

You can configure your model so that the generated code defining the parameter is placed inside #if...#endif statements. To do this, please try the following steps:

 

1) In the "Parent.slx" model's configuration parameters, turn on the 'Use owner from data object for data definition placement' setting in the Code Generation->Code Placement section

2) For the "myParam" parameter (and any others with a similar issue), go to its definition (e.g. in Model Explorer or in a Simulink Data Dictionary) and set the "Owner" property (under Code Generation Options->Custom Attributes) to "Child" (without the quotes)

Now when you generate code, the "myParam" parameter should be defined in "Child.c" and the definition should be inside of an #if...#endif statement.