There's enough source code provided that I was able to patch the Java code to fix a bug: https://github.com/NationalSecurityAgency/ghidra/issues/2#issuecomment-

There's enough source code provided that I was able to patch the Java code to fix a bug: https://github.com/NationalSecurityAgency/ghidra/issues/2#issuecomment-469999523 https://github.com/NationalSecurityAgency/ghidra/issues/2#is... While there's no source for the decompiler, the decompiler binaries themselves are unstripped and C++, meaning they're actually fairly straightforward to reverse. Plus, you get all the Java code that drives the decompiler binaries.