[Soot-list] Pointer Analysis

[Saswat Anand]

Google tells me difference between Union and PointsToSetInternal was 
asked earlier here, and I was the one to ask!! So sorry for asking 
again. Ondrej's reply from that thread (in case it is interesting to 
others):

The Spark points-to set implementations only know about the other Spark
points-to sets implementations. Union is part of the side-effect
analysis, which is external to Spark, and was developed later. So, you
should be able to pass a Spark points-to set to a Union, but not a Union
to a Spark points-to set. There's a static utility method in Union that
takes two PointsToSets and calls the hasNonEmptyIntersection() method
on them the right way around.

Saswat


Saswat Anand wrote:
> 
> Thanks a lot for the quick help! It serves my purpose nicely because I 
> have just one PointsToSet and for a large number of new stmts, I need to 
> check if their corresponding Alloc node is in that PointsToSet. So I can 
> first iterate through all nodes of the set and build a reverse mapping.
> 
> But there still remains another problem. I see class Union also 
> implements PointsToSet. When and where Union is used to represent 
> points-to set? I want to be able to cast PointsToSet's that I get from 
> PointsToAnalysis APIs to PointsToSetInternal. When can I do that safely?
> 
> Saswat
> 
> 
> Manu Sridharan wrote:
> 
>> I'll give this one a try...
>>
>> You can call getNewExpr() on an AllocNode to get the corresponding new 
>> expr.  So, given a PointsToSetInternal, I'd iterate through its 
>> contents (using forall()), and then for each AllocNode in the set, 
>> check if its new expr is the desired one.  I don't think there is a 
>> reverse mapping from new exprs to the corresponding AllocNode.  
>> Someone can correct me if I'm off on this one.
>>
>> -Manu
>>
>> Saswat Anand wrote:
>>
>>> Hello,
>>>
>>> I need some pointers on using soot's points-to analysis and would 
>>> appreciate your help very much.
>>>
>>> I want to find out if the Alloc node corresponding a new statement is 
>>> in a given PointsToSet. Basically, how can I find the Alloc node 
>>> corresponding to a new stmt. If I know that, I can probably use 
>>> PointsToSetInternal: contains( Node n ). But is it safe to do that?
>>>
>>> Thanks,
>>> Saswat
>>>
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>>> Soot-list mailing list
>>> Soot-list at sable.mcgill.ca
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>>
>>
>>
>>
> 
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