!ifExists && !HiveConf.getBoolVar(conf, ConfVars.DROPIGNORESNONEXISTENT);
if (throwException && FunctionRegistry.getFunctionInfo(functionName) == null) {
throw new SemanticException(ErrorMsg.INVALID_FUNCTION.getMsg(functionName));
}
DropMacroDesc desc = new DropMacroDesc(functionName);
rootTasks.add(TaskFactory.get(new FunctionWork(desc), conf));
}