Support Java 6 as a source language.  For 1.5 VMs, rewrite v6 class files to v5.

Review by: tobyr
Issue: 2223


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@3648 8db76d5a-ed1c-0410-87a9-c151d255dfc7

dev/core/src/com/google/gwt/dev/javac/JdtCompiler.java

diff --git a/dev/core/src/com/google/gwt/dev/javac/JdtCompiler.java b/dev/core/src/com/google/gwt/dev/javac/JdtCompiler.java
index fca9dfe..f9e19a7 100644
--- a/dev/core/src/com/google/gwt/dev/javac/JdtCompiler.java
+++ b/dev/core/src/com/google/gwt/dev/javac/JdtCompiler.java
@@ -211,10 +211,14 @@
         CompilerOptions.IGNORE);
     settings.put(CompilerOptions.OPTION_LocalVariableAttribute,
         CompilerOptions.GENERATE);
-    settings.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_1_5);
-    settings.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_1_5);
+
+    /*
+     * Wish we could target 1.5 class file, but this isn't allowed. :(
+     */
+    settings.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_1_6);
+    settings.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_1_6);
     settings.put(CompilerOptions.OPTION_TargetPlatform,
-        CompilerOptions.VERSION_1_5);
+        CompilerOptions.VERSION_1_6);
 
     // This is needed by TypeOracleBuilder to parse metadata.
     if (enableDocCommentSupport) {

dev/core/src/com/google/gwt/dev/shell/rewrite/ForceClassVersion15.java

diff --git a/dev/core/src/com/google/gwt/dev/shell/rewrite/ForceClassVersion15.java b/dev/core/src/com/google/gwt/dev/shell/rewrite/ForceClassVersion15.java
new file mode 100644
index 0000000..b6839cc
--- /dev/null
+++ b/dev/core/src/com/google/gwt/dev/shell/rewrite/ForceClassVersion15.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2008 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.dev.shell.rewrite;
+
+import com.google.gwt.dev.asm.ClassAdapter;
+import com.google.gwt.dev.asm.ClassVisitor;
+import com.google.gwt.dev.asm.Opcodes;
+
+/**
+ * Performs any rewriting necessary to ensure that class files are 1.5
+ * compatible.
+ */
+class ForceClassVersion15 extends ClassAdapter {
+
+  public ForceClassVersion15(ClassVisitor v) {
+    super(v);
+  }
+
+  @Override
+  public void visit(final int version, final int access, final String name,
+      final String signature, final String superName, final String[] interfaces) {
+    assert (version >= Opcodes.V1_5 && version <= Opcodes.V1_6);
+    super.visit(Opcodes.V1_5, access, name, signature, superName, interfaces);
+  }
+}

dev/core/src/com/google/gwt/dev/shell/rewrite/HostedModeClassRewriter.java

diff --git a/dev/core/src/com/google/gwt/dev/shell/rewrite/HostedModeClassRewriter.java b/dev/core/src/com/google/gwt/dev/shell/rewrite/HostedModeClassRewriter.java
index 9dbcefb..418429b 100644
--- a/dev/core/src/com/google/gwt/dev/shell/rewrite/HostedModeClassRewriter.java
+++ b/dev/core/src/com/google/gwt/dev/shell/rewrite/HostedModeClassRewriter.java
@@ -187,6 +187,10 @@
 
     v = new RewriteJsniMethods(v);
 
+    if (Double.parseDouble(System.getProperty("java.class.version")) < Opcodes.V1_6) {
+      v = new ForceClassVersion15(v);
+    }
+
     new ClassReader(classBytes).accept(v, 0);
     return writer.toByteArray();
   }