[Soot-list] unreachable code in jimple files?

[Martin Schäf]

Oh, and btw, the problem only occurs if I run soot on the .class file and
not for the .java file.


On Mon, Sep 1, 2014 at 11:36 AM, Martin Schäf <martinschaef at gmail.com>
wrote:

> Nope, that doesn't help. If we go back to the Jimple snippet from my
> earlier emails, the problem seems to be that you have these two traps:
>          catch java.lang.Throwable from label0 to label16 with label21;
>         catch java.lang.Throwable from label0 to label16 with label23;
> where the latter is technically unreachable but seems to be considered in
> the dataflow analysis. In this code (pasted below), if you jump to label21,
> the check r25==null is trivial. However, if you would jump directly to
> label23, you could reach r5==null where it is actually true.
> So the problem seems to be that there are infeasible edges in the
> exceptional unit graph (which could be weeded out) ...
>
>      label21:
>         $r24 := @caughtexception;
>
>      label22:
>         r25 = $r24;
>         r5 = r25;
>         throw r25;
>
>      label23:
>         $r26 := @caughtexception;
>         r11 = $r26;
>
>      label24:
>         if r4 == null goto label29;
>
>         if r5 == null goto label28;
>
>
> On Mon, Sep 1, 2014 at 9:35 AM, Bodden, Eric <
> eric.bodden at sit.fraunhofer.de> wrote:
>
>> > Hmmm, so are you actually running a transformation that evaluates the
>> nullness information to turn checks like if(r4==null) into if(false)?
>>
>> I just checked... specifically that would be
>> soot.jimple.toolkits.annotation.nullcheck.NullCheckEliminator. Are you
>> running this one? And it shows no effect on this code?
>>
>> Cheers,
>> Eric
>>
>
>
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