Description Ivan Popov 2007-01-10 07:46:13 EST

Build ID: M20060921-0945

Steps To Reproduce:
1. Install TPTP profiler 4.3.0 and New Java Profiler
2. Get Harmony JRE snapshot from http://harmony.apache.org
3. Set up New Agent Controller to use Harmony JRE
4. Run Eclipse and create HelloWorld application
5. Start profiling HelloWorld and choose Execution Time Analysis
6. See VerifyError exception dump appeared in output console


More information:
Harmony JVM rejects HelloWorld class instrumented by TPTP JVMTI profiler and throws VerifyError exception:

Uncaught exception in main:
java.lang.VerifyError: (class: HelloWorld, method: <init>()V) Uninitialized reference usage
	at java.lang.VMClassRegistry.defineClass(Native Method)
	at java.lang.ClassLoader.defineClass(Unknown Source)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:70)
	at java.net.URLClassLoader.findClassImpl(URLClassLoader.java:1137)
	at java.net.URLClassLoader$4.run(URLClassLoader.java:619)
	at java.net.URLClassLoader$4.run(URLClassLoader.java:1)
	at java.security.AccessController.doPrivilegedImpl(Unknown Source)
	at java.security.AccessController.doPrivileged(Unknown Source)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:621)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader$SystemClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
FAILED to invoke JVM.

It looks like that Martini CG instrumentation is incorrect, though it is accepted by Sun and JRockit JRE. Below is explanation from Harmony developers.

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According Java Specification 1.5 Chapter 4.11.1.1:
“There is never an uninitialized class instance in a local variable in code protected by an exception handler.”

There is a disassembler of instrumented class:

Method name:"<init>" public Signature: 6=()void
Attribute "Code", length:95, max_stack:2, max_locals:1, code_length:45
  0: getstatic #41=<Field mytests.HelloWorld.sm_bAlreadyInvoked70056 boolean>
  3: ldc_w #62=<Integer 70056>
  6: invokestatic #53=<Method org.eclipse.tptp.martini.CGProxy.MethodEnter (boolean,int)void>
  9: getstatic #41=<Field mytests.HelloWorld.sm_bAlreadyInvoked70056 boolean>
 12: ifne 19
 15: iconst_1
 16: putstatic #41=<Field mytests.HelloWorld.sm_bAlreadyInvoked70056 boolean>
 19: aload_0
 20: invokespecial #8=<Method java.lang.Object.<init> ()void>
 23: goto_w 28
 28: nop
 29: ldc_w #62=<Integer 70056>
 32: invokestatic #57=<Method org.eclipse.tptp.martini.CGProxy.MethodLeave (int)void>
 35: nop
 36: return
 37: ldc_w #62=<Integer 70056>
 40: invokestatic #57=<Method org.eclipse.tptp.martini.CGProxy.MethodLeave (int)void>
 43: nop
 44: athrow
Exceptions (count: 1):
  start: 19, end: 29, handler: 37, type: 0 /* finally */
Attribute "LineNumberTable", length:6, count: 1
  line: 3 at pc: 19
Attribute "LocalVariableTable", length:12, count: 1
  slot#0: name: 12=this, type: 13=mytests.HelloWorld (pc: 19 length: 26)

As you can see try block protects a class constructor. Uninitialized reference of class is contained in local variables on this basic block.

Why reference VM doesn’t reject such class, this is a question of investigation. And I could take some time.

I suggest several ways to complete test run:
1.	Change classes instrumentation to correct one. 
2.	Disable verifier and repeat TPTP tests run. 

To disable verifier VM need to give an option in command line: -XDvm.use_verifier=false.
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