7014734: Project Coin: Allow optional trailing semicolon to terminate resources list in try-with-resources

Reviewed-by: jjg

langtools/src/share/classes/com/sun/tools/javac/parser/JavacParser.java

@@ -1639,7 +1639,7 @@ public class JavacParser implements Parser {
      *     | WHILE ParExpression Statement
      *     | DO Statement WHILE ParExpression ";"
      *     | TRY Block ( Catches | [Catches] FinallyPart )
-     *     | TRY "(" ResourceSpecification ")" Block [Catches] [FinallyPart]
+     *     | TRY "(" ResourceSpecification ";"opt ")" Block [Catches] [FinallyPart]
      *     | SWITCH ParExpression "{" SwitchBlockStatementGroups "}"
      *     | SYNCHRONIZED ParExpression Block
      *     | RETURN [Expression] ";"
@@ -2182,13 +2182,12 @@ public class JavacParser implements Parser {
         ListBuffer<JCTree> defs = new ListBuffer<JCTree>();
         defs.append(resource());
         while (S.token() == SEMI) {
-            // All but last of multiple declarators subsume a semicolon
+            // All but last of multiple declarators must subsume a semicolon
             storeEnd(defs.elems.last(), S.endPos());
             int semiColonPos = S.pos();
             S.nextToken();
-            if (S.token() == RPAREN) { // Illegal trailing semicolon
+            if (S.token() == RPAREN) { // Optional trailing semicolon
                                        // after last resource
-                error(semiColonPos, "try.resource.trailing.semi");
                 break;
             }
             defs.append(resource());

langtools/src/share/classes/com/sun/tools/javac/resources/compiler.properties

@@ -298,9 +298,6 @@ compiler.err.final.parameter.may.not.be.assigned=\
 compiler.err.try.resource.may.not.be.assigned=\
     auto-closeable resource {0} may not be assigned
 
-compiler.err.try.resource.trailing.semi=\
-    illegal trailing semicolon in resources declaration
-
 # 0: symbol
 compiler.err.multicatch.parameter.may.not.be.assigned=\
     multi-catch parameter {0} may not be assigned

langtools/test/tools/javac/TryWithResources/BadTwrSyntax.java

@@ -4,13 +4,18 @@
  * @author Joseph D. Darcy
  * @summary Verify bad TWRs don't compile
  * @compile/fail -source 6 BadTwrSyntax.java
- * @compile/fail/ref=BadTwrSyntax.out  -XDrawDiagnostics BadTwrSyntax.java
+ * @compile/fail/ref=BadTwrSyntax.out -XDrawDiagnostics BadTwrSyntax.java
  */
 
 import java.io.IOException;
 public class BadTwrSyntax implements AutoCloseable {
     public static void main(String... args) throws Exception {
-        // illegal semicolon ending resources
+        // illegal double semicolon ending resources
+        try(BadTwr twrflow = new BadTwr();;) {
+            System.out.println(twrflow.toString());
+        }
+
+        // but one semicolon is fine
         try(BadTwr twrflow = new BadTwr();) {
             System.out.println(twrflow.toString());
         }

langtools/test/tools/javac/TryWithResources/BadTwrSyntax.out

@@ -1,2 +1,7 @@
-BadTwrSyntax.java:14:42: compiler.err.try.resource.trailing.semi
-1 error
+BadTwrSyntax.java:14:43: compiler.err.illegal.start.of.type
+BadTwrSyntax.java:14:44: compiler.err.expected: =
+BadTwrSyntax.java:14:45: compiler.err.expected: ')'
+BadTwrSyntax.java:14:47: compiler.err.expected: '{'
+BadTwrSyntax.java:15:19: compiler.err.illegal.start.of.expr
+BadTwrSyntax.java:15:23: compiler.err.expected: ';'
+6 errors

langtools/test/tools/javac/diags/examples/TryResourceTrailingSemi.java

@@ -1,35 +0,0 @@
-/*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-// key: compiler.err.try.resource.trailing.semi
-
-class TryResoureTrailingSemi implements AutoCloseable {
-    public static void main(String... args) {
-        try(TryResoureTrailingSemi r = new TryResoureTrailingSemi();) {
-            System.out.println(r.toString());
-        }
-    }
-
-    @Override
-    public void close() {return;}
-}