If you don’t have source code for your internal representation, but need to debug, you can generate a C-like representation of the functions in your context using gcc_jit_context_dump_to_file():
gcc_jit_context_dump_to_file (ctxt, "/tmp/something.c",
1 /* update_locations */);
This will dump C-like code to the given path. If the update_locations argument is true, this will also set up gcc_jit_location information throughout the context, pointing at the dump file as if it were a source file, giving you `something' you can step through in the debugger.