From 59676745319b864fe3b8fd61710e730e760f5afd Mon Sep 17 00:00:00 2001
From: Michael Peyton Jones <michaelpj@gmail.com>
Date: Mon, 22 Feb 2016 11:55:34 +0000
Subject: [PATCH] Track 'prefix' and 'other' alternatives together

These alternatives are not treated differently after they are created,
and we want to retain their alternative ordering.
---
 .../analysis/LeftRecursiveRuleAnalyzer.java   | 19 +++++++++----------
 .../LeftRecursiveRuleTransformer.java         |  1 -
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleAnalyzer.java b/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleAnalyzer.java
index 5b6ba058f..0bf3708fb 100644
--- a/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleAnalyzer.java
+++ b/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleAnalyzer.java
@@ -30,6 +30,12 @@
 
 package org.antlr.v4.analysis;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
 import org.antlr.runtime.CommonToken;
 import org.antlr.runtime.Token;
 import org.antlr.runtime.TokenStream;
@@ -51,12 +57,6 @@ import org.stringtemplate.v4.ST;
 import org.stringtemplate.v4.STGroup;
 import org.stringtemplate.v4.STGroupFile;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-
 /** Using a tree walker on the rules, determine if a rule is directly left-recursive and if it follows
  *  our pattern.
  */
@@ -69,7 +69,6 @@ public class LeftRecursiveRuleAnalyzer extends LeftRecursiveRuleWalker {
 	public LinkedHashMap<Integer, LeftRecursiveRuleAltInfo> ternaryAlts = new LinkedHashMap<Integer, LeftRecursiveRuleAltInfo>();
 	public LinkedHashMap<Integer, LeftRecursiveRuleAltInfo> suffixAlts = new LinkedHashMap<Integer, LeftRecursiveRuleAltInfo>();
 	public List<LeftRecursiveRuleAltInfo> prefixAlts = new ArrayList<LeftRecursiveRuleAltInfo>();
-	public List<LeftRecursiveRuleAltInfo> otherAlts = new ArrayList<LeftRecursiveRuleAltInfo>();
 
 	/** Pointer to ID node of ^(= ID element) */
 	public List<Pair<GrammarAST,String>> leftRecursiveRuleRefLabels =
@@ -222,7 +221,9 @@ public class LeftRecursiveRuleAnalyzer extends LeftRecursiveRuleWalker {
 		String altLabel = altTree.altLabel!=null ? altTree.altLabel.getText() : null;
 		LeftRecursiveRuleAltInfo a =
 			new LeftRecursiveRuleAltInfo(alt, altText, null, altLabel, false, originalAltTree);
-		otherAlts.add(a);
+		// We keep other alts with prefix alts since they are all added to the start of the generated rule, and
+		// we want to retain any prior ordering between them
+		prefixAlts.add(a);
 //		System.out.println("otherAlt " + alt + ": " + altText);
 	}
 
@@ -255,7 +256,6 @@ public class LeftRecursiveRuleAnalyzer extends LeftRecursiveRuleWalker {
 		}
 
 		ruleST.add("primaryAlts", prefixAlts);
-		ruleST.add("primaryAlts", otherAlts);
 
 		tool.log("left-recursion", ruleST.render());
 
@@ -440,7 +440,6 @@ public class LeftRecursiveRuleAnalyzer extends LeftRecursiveRuleWalker {
 			   ", ternaryAlts=" + ternaryAlts +
 			   ", suffixAlts=" + suffixAlts +
 			   ", prefixAlts=" + prefixAlts +
-			   ", otherAlts=" + otherAlts +
 			   '}';
 	}
 }
diff --git a/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleTransformer.java b/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleTransformer.java
index ea67493f9..0df860807 100644
--- a/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleTransformer.java
+++ b/tool/src/org/antlr/v4/analysis/LeftRecursiveRuleTransformer.java
@@ -169,7 +169,6 @@ public class LeftRecursiveRuleTransformer {
 		// track recursive alt info for codegen
 		r.recPrimaryAlts = new ArrayList<LeftRecursiveRuleAltInfo>();
 		r.recPrimaryAlts.addAll(leftRecursiveRuleWalker.prefixAlts);
-		r.recPrimaryAlts.addAll(leftRecursiveRuleWalker.otherAlts);
 		if (r.recPrimaryAlts.isEmpty()) {
 			tool.errMgr.grammarError(ErrorType.NO_NON_LR_ALTS, g.fileName, ((GrammarAST)r.ast.getChild(0)).getToken(), r.name);
 		}