private String replaceNameIfNeeded(String text, String name, String replacementName) {
		if (canParseName(name)) {
			return text;
		}
		nameMap.put(replacementName, name);
		return substitute(text, name, replacementName);
	}
Parse the given function signature text into a FunctionDefinitionDataType.

@param originalSignature the function signature before editing. This may be
                         null if the user is entering a new signature instead
                         of editing an existing one.
@param signatureText     the text to be parsed into a function signature.
@return the FunctionDefinitionDataType resulting from parsing.
@throws ParseException if the text could not be parsed.
@throws CancelledException if parse cancelled by user
Ghidra/Features/Base/src/main/java/ghidra/app/util/parser/FunctionSignatureParser.java