Fix for issue 299: labels would break 'val' in javac.

2 files changed, 22 insertions, 0 deletions

diff --git a/src/core/lombok/javac/JavacResolution.java b/src/core/lombok/javac/JavacResolution.java
index e0d56b85..29f261c6 100644
--- a/src/core/lombok/javac/JavacResolution.java
+++ b/src/core/lombok/javac/JavacResolution.java
@@ -221,6 +221,11 @@ public class JavacResolution {
 		}
 	}
 	
+	/*
+	 * We need to dig down to the level of the method or field declaration or (static) initializer block, then attribute that entire method/field/block using
+	 * the appropriate environment. So, we start from the top and walk down the node tree until we hit that method/field/block and stop there, recording both
+	 * the environment object (`env`) and the exact tree node (`copyAt`) at which to begin the attr process.
+	 */
 	private static final class EnvFinder extends JCTree.Visitor {
 		private Env<AttrContext> env = null;
 		private Enter enter;
diff --git a/src/utils/lombok/javac/TreeMirrorMaker.java b/src/utils/lombok/javac/TreeMirrorMaker.java
index db824505..30915572 100644
--- a/src/utils/lombok/javac/TreeMirrorMaker.java
+++ b/src/utils/lombok/javac/TreeMirrorMaker.java
@@ -26,6 +26,7 @@ import java.util.IdentityHashMap;
 import java.util.Iterator;
 import java.util.Map;
 
+import com.sun.source.tree.LabeledStatementTree;
 import com.sun.source.tree.VariableTree;
 import com.sun.tools.javac.tree.JCTree;
 import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
@@ -33,6 +34,16 @@ import com.sun.tools.javac.tree.TreeCopier;
 import com.sun.tools.javac.tree.TreeMaker;
 import com.sun.tools.javac.util.List;
 
+/**
+ * Makes a copy of any AST node, with some exceptions.
+ * Exceptions:<ul>
+ * <li>The symbol ('sym') of a copied variable isn't copied.
+ * <li>all labels are removed.
+ * </ul>
+ * 
+ * The purpose of this class is to make a copy, and then the copy is attributed (resolution info is added). These exceptions
+ * are to work around apparent bugs (or at least inconsistencies) in javac sources.
+ */
 public class TreeMirrorMaker extends TreeCopier<Void> {
 	private final IdentityHashMap<JCTree, JCTree> originalToCopy = new IdentityHashMap<JCTree, JCTree>();
 	
@@ -83,4 +94,10 @@ public class TreeMirrorMaker extends TreeCopier<Void> {
 		copy.sym = ((JCVariableDecl) node).sym;
 		return copy;
 	}
+	
+	// Fix for NPE in HandleVal. See http://code.google.com/p/projectlombok/issues/detail?id=299
+	// This and visitVariable is rather hacky but we're working around evident bugs or at least inconsistencies in javac.
+	@Override public JCTree visitLabeledStatement(LabeledStatementTree node, Void p) {
+		return node.getStatement().accept(this, p);
+	}
 }