public void processNested(Token actionToken) {
		ANTLRStringStream in = new ANTLRStringStream(actionToken.getText());
		in.setLine(actionToken.getLine());
		in.setCharPositionInLine(actionToken.getCharPositionInLine());
		ActionSplitter splitter = new ActionSplitter(in, this);
		// forces eval, triggers listener methods
		splitter.getActionTokens();
	}
Find token and rule refs plus refs to them in actions;
 side-effect: update Alternatives
tool/src/org/antlr/v4/semantics/ActionSniffer.java