[Soot-list] Exception Table

[Silviu ANDRICA]

Hello,
    my problem is that "label3: store.r $r6;" is not caught by the 
exception handler whose head it is.

Patrick Lam wrote:
> Silviu ANDRICA wrote:
>   
>> The Baf translation adds, for the first trap, "label3: store.r $r6;".
>> The problem is that, now an exceptional edge from it to the second trap
>> handler: "label8: store.r $r6;" which does not guarantee that the second
>> acquired lock is released: if the first exitmonitor fails and then
>> "label 3" fails, then control reaches "label 8" and then only one, the
>> first, lock is released.
>>     
>
> I'm having some trouble understanding your explanation of the problem.
>
> It's clear that the problem is not in the Java-to-Jimple translation,
> since the problem occurs in javac-produced code. It's also clear that
> it's not in the Jimple-to-baf translation, since the problem occurs in
> Jimple.
>
> Are you saying that the statement $r6 := @caughtexception (also known as
> store.r $r6) can throw an exception? Which exception could it throw?
>
>   
There is an edge, in ExcepionalGraphUnit, from label 3 to label 8 which 
should not be, if I understood correctly the Java bytecode exception 
table representation.

I overrode the buildExceptionsDests in ExceptionalUnitGraph so that 
it'll print the ThrowableSet for each unit and I got this:

Unit $r6 := @caughtexception might throw 
soot.toolkits.exceptions.ThrowableSet at 4edc41c5:
  +Any_subtype_of_java.lang.Throwable


The instructions that I modified in the buildExceptionalDests was the 
check if thrownSet is null. I modified it in the following way:
if (thrownSet == null) {
                    thrownSet = throwAnalysis.mightThrow(unit);
                    System.out.println("Unit " + unit + " might throw "
                            + thrownSet);
                }

I also copied the addDestToMap and subclassed the ExceptionDest in order 
to make it compile.


Silviu
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