JDO11 RI enhancer support for JDK1.5 classfiles

• Key: JDO-195
• Type: New Feature
• Status: Closed
• Resolution: Won't Fix
• Priority: Minor
• Assignee: Martin Zaun
• Reporter: Martin Zaun
• Component/s: ri11

Description

The JDO11 RI enhancer should be extended to support JDK 1.5 classfiles.

According to the JDK 1.5 ammendments to the VM Spec, 2nd edition
  http://java.sun.com/docs/books/vmspec/2nd-edition/jvms-maintenance.html
support for the following new features is needed:

- new major, minor version number: {49,0}

- new access and property modifiers:
  - new class modifiers:
    ACC_ANNOTATION 0x2000 Declared as an annotation type.
    ACC_ENUM 0x4000 Declared as an enum type.
  - new field flag:
    ACC_ENUM 0x4000 Declared as an element of an enum.
  - new method flags:
    ACC_BRIDGE 0x0040 A bridge method, generated by the compiler.
    ACC_VARARGS 0x0080 Declared with variable number of arguments.

- new opcode: invokedynamic
  Operation: Invoke instance method; resolve and dispatch based on class
  Format: invokedynamic, indexbyte1, indexbyte2
  Forms: invokedynamic = 186 (0xba)
  Operand Stack: ..., objectref, [arg1, [arg2 ,T](B] => ...

- new ldc, ldc_w operand type: CONSTANT_Class

- new Signature Attribute
  It needs to be investigated whether Signature attributes have to be
  supplied for JDO methods that carry the type of managed fields or
  the PC class as parameter or return.

- The other new, pre-defined attributes don't need explicit support but
  can be handled by the enhancer generically:
  - new EnclosingMethod attribute
  - new RuntimeVisibleAnnotations attribute
  - new RuntimeInvisibleAnnotations attribute
  - new RuntimeVisibleParameterAnnotations attribute
  - new RuntimeInvisibleParameterAnnotations attribute
  - new AnnotationDefault attribute
  - new SourceDebugExtension Attribute
  - new LocalVariableTypeTable Attribute

Comments

There's an open issue whether Signature attributes have to be
supplied for augmented JDO methods that carry the type of managed
fields or the PC class as parameter or return. This patch provides
support for SignatureAttribute in the enhancer's classfile library
but does not have the changes to the enhancer's core component to
generate signatures for the JDO accessor, mutator, and jdoCopyField
methods. Once resolved, we might address this by a second patch.

Martin

[Michael Bouschen]

I can't say much about the patch, just two comments:

- It looks like the new opcode opc_invokedynamic replaces the placeholder opc_xxxunusedxxx used in the old code. There are a couple of places where the old code used the placeholder opc_xxxunusedxxx and the new code still has this line in comments. I propose to remove this comment. Please have a look at VMOp.java, Insn.java, InsnSingle.java and VMConstants.java.
- The patch sets the executable flag for file SignatureAttribute.java. I'm not sure whether this is na issue, but please check whether the file has the correct permissions before you check in.

[Craig Russell]

No more work is being planned for this release.