Question

I am using ASM 4.0 and have encountered a strange problem with org/jboss/jms/client/delegate/ClientClusteredConnectionFactoryDelegate.class class from JBoss distribution

The problem is that after no-op transformation one of the methods of this class,

public synchronized byte[]
org$jboss$jms$client$delegate$ClientClusteredConnectionFactoryDelegate$getClientAOPStack$aop()
has the following

  LineNumberTable:
    line 232: 0
    line 240: 52
    line 242: 77

   LocalVariableTable:
    Start  Length  Slot  Name   Signature
    52      -52      2    aopStackProvider
Lorg/jboss/jms/delegate/ConnectionFactoryDelegate;
    0      0      2    e
Lorg/jboss/jms/exception/MessagingNetworkFailureException;
    36      -36      1    server       I
    0      0      0    this
Lorg/jboss/jms/client/delegate/ClientClusteredConnectionFactoryDelegate;

And before transformation those were:

   LineNumberTable:
    line 232: 0
    line 234: 34
    line 238: 45
    line 240: 52
    line 242: 77
    line 244: 84
    line 246: 85
    line 234: 116
    line 250: 122

   LocalVariableTable:
    Start  Length  Slot  Name   Signature
    52      32      2    aopStackProvider
Lorg/jboss/jms/delegate/ConnectionFactoryDelegate;
    85      31      2    e
Lorg/jboss/jms/exception/MessagingNetworkFailureException;
    36      86      1    server       I
    0      132      0    this
Lorg/jboss/jms/client/delegate/ClientClusteredConnectionFactoryDelegate;

As a result I have
java.lang.ClassFormatError: Invalid length 65484 in LocalVariableTable
in class file org/jboss/jms/client/delegate/ClientClusteredConnectionFactoryDelegate

Can anyone help me with this problem?

Answer 1

A colleague of mine found out the following: If for some reason, in the original bytecode LocalVariableTable contains invalid offsets, which point not at the end of the instruction, but in the middle of it, then after visiting by ASM, one gets negative offsets. The solution would be either to strip off debug information completely, by using ClassReader.SKIP_DEBUG option of ASM. Or to detect when ASM cannot determine the end offset of the local variable and to skip that particular variable in visitLocalVariable method of MethodAdapter