[
https://issues.apache.org/jira/browse/BCEL-124?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Emmanuel Bourg updated BCEL-124:
--------------------------------
Priority: Major
Fix Version/s: 6.0
Priority: (was: P2)
Severity: (was: normal)
> tableswitch/lookupswitch invalid alignment of 4-byte operands
> -------------------------------------------------------------
>
> Key: BCEL-124
> URL: https://issues.apache.org/jira/browse/BCEL-124
> Project: Commons BCEL
> Issue Type: Bug
> Components: Main
> Affects Versions: 5.2
> Environment: Operating System: All
> Platform: All
> Reporter: Timothy Alper
> Assignee: Apache Commons Developers
> Fix For: 6.0
>
> Attachments: SetPositionsBug.java, bug45230.patch
>
>
> It is possible, with BCEL, to generate invalid alignment of the 4-byte
> operands of the Select instructions. The problem is caused by the interaction
> of InstructionList.setPositions, the updatePosition methods of GOTO and JSR,
> and Select.updatePosition.
> In particular, the updatePosition methods of GOTO and JSR will always return
> the difference between the wide instruction length and the normal instruction
> length. Since this value ends up being added into the additional_bytes
> variable in InstructionList.setPositions and then eventually contributes to
> the value passed into Select.updatePosition as the offset, its incorrect
> value causes the padding field to be set incorrectly.
> It appears that in order to behave properly, the updatePosition method should
> return only the number of bytes of length that the instruction changed during
> this call to updatePosition.
> I am attaching a small example application that displays the bug.
> I will also be attaching a patch.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
