[hubertus65]

Four blocks of Modelica.ComplexBlocks.ComplexMath (Feedback, Gain, Division, Add3) and Modelica.ComplexBlocks.Sources.ComplexStep write a Complex if-expression inline in the equation of their output connector:

y = k*(if useConjugateInput then Modelica.ComplexMath.conj(u) else u);   // Gain
y = offset + (if time < startTime then Complex(0) else height);           // ComplexStep

OCT, the compiler of Modelon Impact, generates C code for these equations that does not compile. The code contains the record constructor of the connector type, Modelica.ComplexBlocks.Interfaces.ComplexOutput(...). As a result none of the five blocks can be used in Impact, with or without conjugated inputs.

Other blocks of the same package are not affected. Add and Product first assign the if-expression to a protected variable (u1Internal, u2Internal from Interfaces.ComplexSI2SO, or uInternal from Interfaces.ComplexSISO).

This PR applies that existing pattern to the five blocks:

• Gain: protected uInternal, then y = k*uInternal
• Feedback: protected u1Internal, u2Internal
• Add3: protected u1Internal … u3Internal
• Division: already extends ComplexSI2SO; now uses its u1Internal/u2Internal instead of repeating the if-expressions
• ComplexStep: protected stepValue

Public interfaces, parameters and documentation are unchanged.

Verification

Model	OpenModelica 1.27.1, before vs. after	OCT (Impact), before	OCT (Impact), after
ComplexBlocks.Examples.ShowTransferFunction	bit-identical	–	–
ComplexBlocks.Examples.TestConversionBlock	bit-identical	–	–
Test using Feedback, Gain, Division, Add3, with and without conjugation	bit-identical	C compile error	simulates, same values as OpenModelica
Test using ComplexStep	bit-identical	C compile error	simulates, same values as OpenModelica
Other ModelicaTest models (ComplexMathFunctions, ComplexMathOperators)	bit-identical	–	–

The "after" column for OCT was produced with copies of the patched classes, since Impact ships its own MSL. The test models are part of the ModelicaTest coverage work on branch coverage-improvement.

🤖 Generated with Claude Code

https://claude.ai/code/session_01UmNZkRw6HV9CeBvNk36AzT