adding customized functions to the modules

I am new to llvm, so I apologise for the trivial question.

I have an AST from antlr, and I am walking the tree and generating llvm IR from it. When I get a function definition, I call ->getOrInsertFunction(…). But, my function arguments can have parameter or return types not defined in enum TypeID. So, is there a way to map such functions? Or is the only way to do this is to map the datatpes to the llvm antlr types?

Thanks

LLVM IR can only contain LLVM IR types. You'll have to perform some sort
of mapping.

-Eli