# Similar to `build_c_signature` but adapted to create the signature expected by JNI for C functions
	# implementing Java extern methods.
	#
	# Is used to generate FFI callbacks to Nit at `MExplicitCall::compile_callback_to_java`.
	private fun build_c_implementation_signature(recv_mtype: MClassType, from_mmodule: MModule,
		suffix: nullable String, length: SignatureLength, call_context: CallContext): String
	do
		var mmethoddef = lookup_first_definition(from_mmodule, recv_mtype)
		var signature = mmethoddef.msignature
		assert signature != null

		var creturn_type
		if self.is_init then
			creturn_type = call_context.name_mtype(recv_mtype)
		else if signature.return_mtype != null then
			var ret_mtype = signature.return_mtype
			ret_mtype = ret_mtype.resolve_for(recv_mtype, recv_mtype, from_mmodule, true)
			creturn_type = call_context.name_mtype(ret_mtype)
		else
			creturn_type = "void"
		end

		var cname = build_cname(recv_mtype, from_mmodule, suffix, length)

		var cparams = new List[String]

		cparams.add "JNIEnv *nit_ffi_jni_env"
		cparams.add "jclass clazz"

		if not self.is_init then
			cparams.add "{call_context.name_mtype(recv_mtype)} self"
		end
		for p in signature.mparameters do
			var param_mtype = p.mtype.resolve_for(recv_mtype, recv_mtype, from_mmodule, true)
			cparams.add "{call_context.name_mtype(param_mtype)} {p.name}"
		end

		return "{creturn_type} {cname}( {cparams.join(", ")} )"
	end