protected final FunctionDefinitionDataType parseSignature() throws CancelledException {
		setFunctionInfo(); // needed for testing which never shows dialog
		FunctionSignatureParser parser = new FunctionSignatureParser(getDataTypeManager(),
			tool.getService(DataTypeManagerService.class));
		try {
			return parser.parse(getFunctionSignature(), getSignature());
		}
		catch (ParseException e) {
			setStatusText("Invalid Signature: " + e.getMessage());
		}
		return null;
	}
Perform parse of current user-specified function signature (see {@link #getSignature()})
and return valid {@link FunctionDefinitionDataType} if parse successful.
@return function definition data type if parse successful, otherwise null
@throws CancelledException if function signature entry cancelled
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/function/AbstractEditFunctionSignatureDialog.java