Fixed bug 383046: [1.8][compiler] Error getting reported on the

lambda expression if there is a subsequent parse error

4 files changed, 58 insertions, 3 deletions

diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/LambdaExpressionsNegativeTest.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/LambdaExpressionsNegativeTest.java
index fdd1a59e58..82cc7e5ecf 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/LambdaExpressionsNegativeTest.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/LambdaExpressionsNegativeTest.java
@@ -105,6 +105,26 @@ public void test003() {
 			"Type mismatch: cannot convert from I to int\n" + 
 			"----------\n");
 }
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=383046, syntax error reported incorrectly on syntactically valid lambda expression
+public void test004() {
+	this.runNegativeTest(
+			new String[] {
+				"X.java",
+				"interface IX {\n" +
+				"    public void foo();\n" +
+				"}\n" +
+				"public class X {\n" +
+				"     IX i = () -> 42;\n" +
+				"     int\n" +
+				"}\n",
+			},
+			"----------\n" + 
+			"1. ERROR in X.java (at line 6)\n" + 
+			"	int\n" + 
+			"	^^^\n" + 
+			"Syntax error on token \"int\", delete this token\n" + 
+			"----------\n");
+}
 
 public static Class testClass() {
 	return LambdaExpressionsNegativeTest.class;
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/RecoveryScanner.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/RecoveryScanner.java
index 8c09fafe1e..8fe5d13129 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/RecoveryScanner.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/RecoveryScanner.java
@@ -208,7 +208,7 @@ public class RecoveryScanner extends Scanner {
 					this.data.removedTokenUsed[i] = true;
 					this.currentPosition = this.data.removedTokensEnd[i] + 1;
 					this.precededByRemoved = false;
-					return getNextToken();
+					return getNextToken0();
 				}
 			}
 		}
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/Scanner.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/Scanner.java
index dd76a051c2..cddee87ae5 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/Scanner.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/Scanner.java
@@ -192,6 +192,7 @@ public class Scanner implements TerminalTokens {
 	private int nextToken = TokenNameNotAToken; // allows for one token push back, only the most recent token can be reliably ungotten.
 	private final boolean scanningJava8Plus;
 	public boolean shouldDisambiguate;          // feedback from parser about need to disambiguate -- to lookahead only when absolutely necessary.
+	public boolean disambiguatedAlready;
 
 	public static final int RoundBracket = 0;
 	public static final int SquareBracket = 1;
@@ -1143,15 +1144,21 @@ public int getNextToken() throws InvalidInputException {
 	} else {
 		token = getNextToken0();
 	}
+	if (this.disambiguatedAlready) {
+		this.disambiguatedAlready = false;
+		return token;
+	}
 	if (this.scanningJava8Plus && this.shouldDisambiguate) {
 		if (token == TokenNameLPAREN) {
 			if(atLambdaParameterList()) {
 				this.nextToken = token;
+				this.disambiguatedAlready = true;
 				return TokenNameBeginLambda;
 			}
 		} else if (token == TokenNameLESS) {
 			if (atReferenceExpression()) {
 				this.nextToken = token;
+				this.disambiguatedAlready = true;
 				return TokenNameBeginTypeArguments;
 			}
 		}
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/diagnose/DiagnoseParser.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/diagnose/DiagnoseParser.java
index a25da20963..95c03fa355 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/diagnose/DiagnoseParser.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/parser/diagnose/DiagnoseParser.java
@@ -1,9 +1,13 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2008 IBM Corporation and others.
+ * Copyright (c) 2000, 2012 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
@@ -11,6 +15,7 @@
 package org.eclipse.jdt.internal.compiler.parser.diagnose;
 
 import org.eclipse.jdt.core.compiler.CharOperation;
+import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
 import org.eclipse.jdt.internal.compiler.parser.Parser;
 import org.eclipse.jdt.internal.compiler.parser.ParserBasicInformation;
@@ -193,6 +198,9 @@ public class DiagnoseParser implements ParserBasicInformation, TerminalTokens {
 			oldRecord = this.recoveryScanner.record;
 			this.recoveryScanner.record = record;
 		}
+		if (this.options.sourceLevel >= ClassFileConstants.JDK1_8) {
+			this.parser.scanner.shouldDisambiguate = true;
+		}
 		try {
 			this.lexStream.reset();
 
@@ -421,6 +429,7 @@ public class DiagnoseParser implements ParserBasicInformation, TerminalTokens {
 			if(this.recoveryScanner != null) {
 				this.recoveryScanner.record = oldRecord;
 			}
+			this.parser.scanner.shouldDisambiguate = false;
 		}
 		return;
 	}
@@ -2249,10 +2258,13 @@ public class DiagnoseParser implements ParserBasicInformation, TerminalTokens {
 	            	addedTokens = new int[Parser.scope_rhs.length - Parser.scope_suffix[- nameIndex]];
 	            }
 
+	            int insertedToken = TokenNameNotAToken;
 				for (int i = Parser.scope_suffix[- nameIndex]; Parser.scope_rhs[i] != 0; i++) {
 					buf.append(Parser.readableName[Parser.scope_rhs[i]]);
 					if (Parser.scope_rhs[i + 1] != 0) // any more symbols to print?
 						buf.append(' ');
+					else
+						insertedToken = Parser.reverse_index[Parser.scope_rhs[i]];
 
 					if(addedTokens != null) {
 	                	int tmpAddedToken = Parser.reverse_index[Parser.scope_rhs[i]];
@@ -2291,6 +2303,13 @@ public class DiagnoseParser implements ParserBasicInformation, TerminalTokens {
 	            }
 
 				if (scopeNameIndex != 0) {
+					if (insertedToken == TokenNameElidedSemicolonAndRightBrace) {
+						/* https://bugs.eclipse.org/bugs/show_bug.cgi?id=383046, we should never ever report the diagnostic, "Syntax error, insert ElidedSemicolonAndRightBraceto complete LambdaBody"
+						   as it is a synthetic token. Instead we should simply repair and move on. See how the regular Parser behaves at Parser.consumeElidedLeftBraceAndReturn and Parser.consumeExpression.
+						   See also: point (4) in https://bugs.eclipse.org/bugs/show_bug.cgi?id=380194#c15
+						*/
+						break;
+					}
 					if(this.reportProblem) problemReporter().parseErrorInsertToComplete(
 						errorStart,
 						errorEnd,
@@ -2425,12 +2444,14 @@ public class DiagnoseParser implements ParserBasicInformation, TerminalTokens {
 	            if(this.recoveryScanner != null) {
 	            	addedTokens = new int[Parser.scope_rhs.length - Parser.scope_suffix[- nameIndex]];
 	            }
-
+	            int insertedToken = TokenNameNotAToken;
 	            for (int i = Parser.scope_suffix[- nameIndex]; Parser.scope_rhs[i] != 0; i++) {
 
 	                buf.append(Parser.readableName[Parser.scope_rhs[i]]);
 	                if (Parser.scope_rhs[i+1] != 0)
 	                     buf.append(' ');
+	                else
+	                	insertedToken = Parser.reverse_index[Parser.scope_rhs[i]];
 
 	                if(addedTokens != null) {
 	                	int tmpAddedToken = Parser.reverse_index[Parser.scope_rhs[i]];
@@ -2466,6 +2487,13 @@ public class DiagnoseParser implements ParserBasicInformation, TerminalTokens {
 	            	this.recoveryScanner.insertTokens(addedTokens, completedToken, errorEnd);
 	            }
 	            if (scopeNameIndex != 0) {
+	            	if (insertedToken == TokenNameElidedSemicolonAndRightBrace) {
+						/* https://bugs.eclipse.org/bugs/show_bug.cgi?id=383046, we should never ever report the diagnostic, "Syntax error, insert ElidedSemicolonAndRightBraceto complete LambdaBody"
+						   as it is a synthetic token. Instead we should simply repair and move on. See how the regular Parser behaves at Parser.consumeElidedLeftBraceAndReturn and Parser.consumeExpression.
+						   See also: point (4) in https://bugs.eclipse.org/bugs/show_bug.cgi?id=380194#c15
+						*/
+						break;
+					}
 	                if(this.reportProblem) problemReporter().parseErrorInsertToComplete(
 						errorStart,
 						errorEnd,