How do I build the C# grammars for Go?

[F (erbridge)]

I have tried to build the C# grammars for Go using the following command

antlr4 -Dlanguage=Go CSharpLexer.g4 CSharpPreprocessorParser.g4 CSharpParser.g4

But the resulting Go files contain Java code. I filed an issue in the GitHub repo (https://github.com/antlr/antlr4/issues/2174) and was told that this is because the C# grammar contains Java code and to come here instead.

How do I work around this to build for Go?

[Ivan Kochurkin]

Rewrite Java code fragments to Go.