[
https://issues.apache.org/jira/browse/BCEL-172?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Emmanuel Bourg updated BCEL-172:
--------------------------------
Description:
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}
was:
It turned out that finder.search methods generates incorrect output.
For example:
finder.search("invokespecial")
Will find not only some INVOKESPECIAL opcodes but will return InstructionHandle
arrays in form:
[ invokespecial, nextOpCode]
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
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)
because of situation, that after return there is no more instruction(so
InstructionHandler too) to get. It occurs especially for deafult constructors
as they bytecode is like:
invokespecial
return.
Error exists because of errorneus instruction(line 230 in
InstructionFinder.java, method search()):
int lenExpr = (endExpr - startExpr) + 1;
There should be no "+1" part because:
int endExpr = matcher.end();
(which is one line above)
returns index AFTER match.
So bug generally(I didn't tested properly) could be repaired with replacing
errorneus line with:
int lenExpr = (endExpr - startExpr);
> 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
>
> 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)
