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Configuring S-Function for Test Case Generation

This example shows how to compile an S-Function to be compatible with Simulink® Design Verifier™ for test case generation. Simulink Design Verifier supports S-Functions that are:

  • Generated with the Legacy Code Tool, with def.Options.supportCoverageAndDesignVerifier set to true,

  • Generated with the SFunctionBuilder, with Enable support for Design Verifier selected on the Build Info tab of the SFunctionBuilder dialog box, or

  • Compiled with the function slcovmex, with the option -sldv passed.

Compile S-Function to be Compatible with Simulink Design Verifier

The handwritten S-Function is found in the file sldvexSFunctionHandlingSFcn.c, and the user source code for the lookup table is found in the file sldvexSFunctionHandlingSource.c. Call the function slcovmex to compile the C-MEX S-Function and make it compatible with Simulink Design Verifier.

slcovmex('-sldv', ...
        '-output', 'sldvexSFunctionHandlingSFcn',...
        ['-I', fullfile(matlabroot, 'toolbox', 'sldv', 'sldvdemos', 'src')], ...
        fullfile(matlabroot, 'toolbox', 'sldv', 'sldvdemos', 'src', 'sldvexSFunctionHandlingSource.c'),...
        fullfile(matlabroot, 'toolbox', 'sldv', 'sldvdemos', 'src', 'sldvexSFunctionHandlingSFcn.c') ...
mex -I/mathworks/devel/bat/Bdoc22b/build/matlab/toolbox/sldv/sldvdemos/src /tmp/Bdoc22b_2054784_2766247/tpffc6b471_3655_42aa_88a0_37a17e15e544/tpedd274f0_a9f5_4d48_a7c1_55e35a7685e9.c /tmp/Bdoc22b_2054784_2766247/tpffc6b471_3655_42aa_88a0_37a17e15e544/tp0bf0ddf5_71e0_4454_889e_78615340ed92.c -L/mathworks/devel/bat/Bdoc22b/build/matlab/bin/glnxa64 -lmwsl_sfcn_cov_bridge -output sldvexSFunctionHandlingSFcn
Building with 'gcc'.
MEX completed successfully.
mex -I/mathworks/devel/bat/Bdoc22b/build/matlab/toolbox/sldv/sldvdemos/src /mathworks/devel/bat/Bdoc22b/build/matlab/toolbox/sldv/sldvdemos/src/sldvexSFunctionHandlingSource.c /tmp/Bdoc22b_2054784_2766247/tpffc6b471_3655_42aa_88a0_37a17e15e544/sldvexSFunctionHandlingSFcn.c /tmp/Bdoc22b_2054784_2766247/tpffc6b471_3655_42aa_88a0_37a17e15e544/tp968e0118_d4db_4c03_8b6d_f361405b2a64.c /tmp/Bdoc22b_2054784_2766247/tpffc6b471_3655_42aa_88a0_37a17e15e544/tp0e21ce6c_d4ad_4ff6_bb51_5d1b4899deec.c -L/mathworks/devel/bat/Bdoc22b/build/matlab/bin/glnxa64 -lmwsl_sfcn_cov_bridge -output sldvexSFunctionHandlingSFcn
Building with 'gcc'.
MEX completed successfully.

Create Test Suite

The example model sldvexSFunctionHandlingExample example contains the handwritten S-Function, which implements a lookup table algorithm. The S-Function block returns the interpolated value at the first output port and returns the status of the interpolation at the second output port. The second output port returns the value -1 if a lower saturation occurs, 1 if a upper saturation occurs, and 0 otherwise. Open the sldvexSFunctionHandlingExample model and configure the analysis options by turning on S-Function support for test generation. On running the analysis, Simulink Design Verifier returns a test suite that satisfies all coverage objectives.


opts = sldvoptions;
opts.Mode = 'TestGeneration';
opts.ModelCoverageObjectives = 'ConditionDecision';
opts.SaveHarnessModel = 'off';
opts.SaveReport = 'off';
opts.SFcnSupport = 'on';

[status, fileNames] = sldvrun('sldvexSFunctionHandlingExample', opts, true);

Verifying Complete Coverage

The sldvruntest function verifies that the test suite achieves complete model coverage. The cvhtml function produces a coverage report that indicates 100% Condition and Decision coverage is achieved with the generated test vectors.

[~, finalCov] = sldvruntest('sldvexSFunctionHandlingExample', fileNames.DataFile, [], true);
cvhtml('Final Coverage', finalCov);

Clean Up

To complete the demo, close all models.

close_system('sldvexSFunctionHandlingExample', 0);