[ 
https://issues.apache.org/jira/browse/BCEL-172?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Emmanuel Bourg resolved BCEL-172.
---------------------------------

       Resolution: Fixed
    Fix Version/s: 6.0

> Searching bug
> -------------
>
>                 Key: BCEL-172
>                 URL: https://issues.apache.org/jira/browse/BCEL-172
>             Project: Commons BCEL
>          Issue Type: Bug
>          Components: Main
>    Affects Versions: 5.2
>            Reporter: AK
>             Fix For: 6.0
>
>
> It turned out that finder.search methods generates incorrect output.
> For example:
> {code}
> finder.search("invokespecial")
> {code}
> Will find not only some INVOKESPECIAL opcodes but will return 
> InstructionHandle arrays in form:
> {code}
> [   invokespecial,    nextOpCode]
> {code}
> So instead of returning x matching opcode(s) it returns x+1 matching opcodes 
> in one IntructionHandle array. This generates problem when invoking 
> {{finder.search("invokespecial return")}} which will throw
> {code}
> Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException
>       at java.lang.System.arraycopy(Native Method)
>       at 
> org.apache.bcel.util.InstructionFinder.getMatch(InstructionFinder.java:171)
>       at 
> org.apache.bcel.util.InstructionFinder.search(InstructionFinder.java:231)
>       at 
> org.apache.bcel.util.InstructionFinder.search(InstructionFinder.java:250)
>       at Transform.transformMethod(Transform.java:66)
>       at Transform.main(Transform.java:25)
> {code}
> because of situation, that after return there is no more instruction (so 
> InstructionHandler too) to get. It occurs especially for default constructors 
> as they bytecode is like:
> {code}
> invokespecial
> return.
> {code}
> Error exists because of erroneous instruction(line 230 in 
> InstructionFinder.java, method {{search()}}):
> {code}
> int lenExpr = (endExpr - startExpr) + 1;
> {code}
> There should be no "+1" part because:
> {code}
> int endExpr = matcher.end();
> {code}
> (which is one line above)
> returns index AFTER match.
> So bug generally (I didn't tested properly) could be repaired with replacing 
> erroneous line with:
> {code}
> int lenExpr = (endExpr - startExpr);
> {code}



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Reply via email to