How to use the evaluation capabilities of slang

[suzizecat]

Hi there !

In the context of my language server I would like to try and evaluate the various conditions of a SystemVerilog RTL (design) file.

The idea would be to extract all if statements, evaluate the expression with signal value that I provide from the simulation, and display in editor the "false" sections in grayed out or equivalent.
(That would be the same as you would get when using a #ifdef ... #else ... #endif in a C++ editor).

While I should be good for the extraction part and UI stuff, I would like to get some pointer on the evaluation capabilities of slang, and how to use them. I saw stuff like slang::ast::ASTContext or slang::ast::Expression::eval which looks promising, but I don't want to invest too much time on a dead-end.

Could you confirm that this use case is reasonable with regards to slang capabilities and could you roughly explain the required steps to perform this ?

Thanks a lot for slang and the help already provided !
Julien FAUCHER

[MikePopoloski]

Yes, this should be straightforward to do. Create an EvalContext and create local values for variables by using EvalContext::createLocal which returns a pointer to the ConstantValue which you can read or write to be whatever you want. Then call Expression::eval with your context and you'll get a result back.