Invalid reordering in ClassReader

[Werner Dietl]

This changeset:

http://hg.openjdk.java.net/jdk9/dev/langtools/rev/d607ae60772d

contains a re-ordering of how the bytecode is read.

--- a/src/share/classes/com/sun/tools/javac/jvm/ClassReader.java Sun
Feb 02 12:12:01 2014 +0100
+++ b/src/share/classes/com/sun/tools/javac/jvm/ClassReader.java Mon
Feb 03 17:19:15 2014 -0500

         // local variable
-        case LOCAL_VARIABLE:
-        // resource variable
-        case RESOURCE_VARIABLE:
-            int table_length = nextChar();
+        case LOCAL_VARIABLE: {
+            final int table_length = nextChar();
+            final TypeAnnotationPosition position =
+                TypeAnnotationPosition.localVariable(readTypePath());
+
             position.lvarOffset = new int[table_length];
             position.lvarLength = new int[table_length];
             position.lvarIndex = new int[table_length];
@@ -1498,67 +1518,142 @@ public class ClassReader {
                 position.lvarLength[i] = nextChar();
                 position.lvarIndex[i] = nextChar();
             }
-            break;
+            return position;
+        }

The code now reads the TypePath before the local variable information.
This breaks the order in which the ClassWriter writes this information.

This results in a ClassCastException in unrelated code, because the
ClassReader gets confused about the class file.

In type-annotations, I changed the code back:

http://hg.openjdk.java.net/type-annotations/type-annotations/langtools/rev/7e9c983565ac

and this resolves these exceptions.

Is there a reason for this change? I think the previous implementation
did the right ordering according to the spec.

cu, WMD.

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