public static DataTypeSymbol readOverride(Symbol sym) {
		DataTypeSymbol datsym = DataTypeSymbol.readSymbol(AUTO_CAT, sym);
		if (datsym == null) {
			return null;
		}
		DataType dt = datsym.getDataType();
		if (!(dt instanceof FunctionSignature)) {
			return null;
		}
		return datsym;
	}
Read a call prototype override which corresponds to the specified override code symbol
@param sym special call override code symbol whose address corresponds to a call site
@return call prototype override DataTypeSymbol or null if associated function signature
data-type could not be found
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighFunctionDBUtil.java