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Import Custom C++ Class Using the Simulink Code Importer Wizard

Use Simulink® Code Importer to import a custom C++ class into Simulink library.

In this workflow, the source file and the header file are adder_cpp.cpp and adder_cpp.h, respectively.

For adder_cpp.h:

#ifndef _ADDER_CPP_
#define _ADDER_CPP_

class adder {
    int int_state;
    adder(int init_value);
    int add_one(int increment);
    int get_val();

#endif /* _ADDER_CPP_ */

For adder_cpp.cpp:

#include "adder_cpp.h"

/**** Class method definitions ****/

    int_state = 0;

adder::adder(int init_value)
    int_state = init_value;

int adder::add_one(int increment)
    int_state += increment;
    return int_state;

int adder::get_val()
    return int_state;

  1. To open the Code Importer Wizard, create an empty Simulink library where the src and include files are located. To create a blank library, from the Simulink start page, select Blank Library and click Create Library. Optionally, save the library in the working folder.

  2. In the Simulink library toolstrip, on the Modeling tab, in the Design section, select Code Importer.

  3. On the Welcome page, click Start.

  4. On the Settings page:

    • In the Library or model name field, specify a file name for the Simulink library. For this example, a new library importclass is generated.

    • In the Output folder field, specify the folder path where you want to save this library.


      If you save the library in step 1 of this workflow or open a saved library, the Library or model name and the Output folder fields are auto-populated with the library name and the location of the saved library file, respectively.

    Optionally, select Add generated library to Simulink Library Browser to create an sdlblocks.m file. The sdlblocks.m file is used to add the generated library to a Simulink Library Browser. For more information, see Add Libraries to Library Browser.

    Specify library or model name and the folder that stores the library or model.

    Click Next to continue.

  5. On the Specify Custom Code page:

    • For Language, select C++.

    • For Interface headers, specify the required header files. For this example, the header file is adder_cpp.h.

    • For Source files, specify the required source files. For this example, the source file is adder_cpp.cpp.

    • For Include directories, specify the required directories. For this example, this field contains the address of the folder where the header file is located.

    Header and source file specified in Specify Custom Code page.

    Click Next to continue.

  6. On the Analyze page, click Next. Simulink Code Importer analyzes the custom code for classes and their dependencies.

  7. On the Configure page, select the classes to import. For this example, the class is adder.

    Select the classes to import.

    Click Next to continue.

  8. Click the Define Interface button and check the configuration of the Simulink Interface for the adder class. For this example, Constructor for class instantiation is set to adder(void); and Methods for output code is set to int32_T add_one(int32_T increment).

    Optionally, specify Initialization method and Cleanup method.

    Define interface for custom C++ class.

    Click OK to continue.

    Check and specify the following parameters, which integrates the custom C++ class into Simulink.

    • Ports and Parameters

    • Output, Initialize Conditions and Terminate code for simulation and code generation

    Preview and customize C Function block.

    Click OK to continue.

    In the Define Simulink interfaces for the previously selected classes page, click Modify Interface to modify the interface parameters.

    Check C Function block parameter settings.

    Click Next to continue.

  9. On the Import page, check the specifications of the generated library and click Next to continue.

  10. Note

    This option is not available if you are importing this class (adder) to the library generated in the previous step for the first time. This is available only if you have imported this class (adder) to the library generated in the previous step at least once before.

    On this page, the wizard provides two options:

    • Replace existing blocks— Select this option to replace the existing blocks with the new C Function blocks for the selected custom C++ class.

    • Import as new blocks— Select this option to preserve the existing blocks and create a new C Function block for the selected custom C++ class.

    To view the existing blocks, click on the block path address mentioned in Existing Imported Blocks column.

    For this example, select Import as new blocks, then click Next to continue.

    Option to update the library if the selected library already contains blocks that import the class.

  11. This option is available only if you have a Simulink Test™ license. To test the imported custom C++ class using Simulink Test Manager, select Automatically create test harness for all imported functions or classes. Each block in the created library is attached to an internal test harness.

    For this example, select Skip.

    Test harness for imported C++ class.

    Click Next to continue.

  12. After the code imports, the wizard creates a custom C Function block that imports the custom class. You can view this block on the Simulink canvas.

    Custom C Function block.

    If you have an existing project file (PRJ file), you can select Add, select the desired project file, and add the generated file to that project.

    Click Finish to close the wizard. Select whether to save the current import settings to a JSON file. You can use this file to load the Code Importer wizard with the current import settings.

    Code Importer notification when the import finishes.

See Also

Related Topics