mv ruleIndex, add alt

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 9061]

runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java

@@ -53,12 +53,21 @@ public class ParserRuleContext extends RuleContext {
 	public Object tree;
 	public ST st;
 
+	/** Set during parsing to identify which rule parser is in. */
+	public int ruleIndex;
+
+	/** Set during parsing to identify which alt of rule parser is in. */
+	public int alt;
+
 	public ParserRuleContext() { super(); }
 
 	public ParserRuleContext(RuleContext parent, int stateNumber) {
 		super(parent, stateNumber);
 	}
 
+	@Override
+	public int getRuleIndex() { return ruleIndex; }
+
 	public Object getTree() { return tree; }
 	public ST getTemplate() { return st; }
 	public Token getStart() { return start; }

runtime/Java/src/org/antlr/v4/runtime/RuleContext.java

@@ -84,9 +84,6 @@ public class RuleContext implements ParseTree.RuleNode {
 	 */
 	public int s = -1;
 
-	/** Set during parsing to identify which rule parser is in. */
-	public int ruleIndex;
-
 	/** What state invoked the rule associated with this context?
 	 *  The "return address" is the followState of invokingState
 	 *  If parent is null, this should be -1.
@@ -274,6 +271,8 @@ public class RuleContext implements ParseTree.RuleNode {
 
 	public int getChildCount() { return children!=null ? children.size() : 0; }
 
+	public int getRuleIndex() { return -1; }
+
 	public Interval getSourceInterval() {
 		if ( getChildCount()==0 ) return Interval.ZeroLength;
 		int start = getChild(0).getSourceInterval().a;

runtime/Java/src/org/antlr/v4/runtime/tree/Trees.java

@@ -60,7 +60,7 @@ public class Trees {
 	public static String getNodeText(Tree t, BaseRecognizer recog) {
 		if ( recog!=null ) {
 			if ( t instanceof ParseTree.RuleNode ) {
-				int ruleIndex = ((ParseTree.RuleNode)t).getRuleContext().ruleIndex;
+				int ruleIndex = ((ParseTree.RuleNode)t).getRuleContext().getRuleIndex();
 				String ruleName = recog.getRuleNames()[ruleIndex];
 				return ruleName;
 			}