[Soot-list] Spark and aliasing analysis

[Florian Strauß]

Hello,

 

thanks for the helpful tools / framework Soot and Spark. 

In my settings, something is wrong. In want to find out, if two variables
may point to the same object. Therefore I compare the PointsToSets of these
variables. 

Example:

             Object o5 = new Object();

             Object o6 = new Object();

 

This example works fine. In my analyzer the following lines return false: 

 

PointsToAnalysis pointsToGraph = Scene.v().getPointsToAnalysis();

PointsToSet pts1 = pointsToGraph.reachingObjects(localO5);

PointsToSet pts2 = pointsToGraph.reachingObjects(localO6);

return pts1.hasNonEmptyIntersection(pts2);

 

The next example is similar:

              ClassA k1 = new ClassA();

             ClassA k2 = new ClassA();

              

Object o7 = k1.getNewO();

             Object o8 = k2.getNewO();

 

             
.

             //In class ClassA:

public Object getNewO() {

                    return new Object();

              }

 

But in this case, the framework says that the two pointsTo-Sets (of o7 and
o8) has an non empty intersection. 

Furthermore, I found out that the base of a method call is always ignored.
The consequence is that for example two iterator, which are returned by
java.util.AbstractList, point to the same objects even if the list instances
and elements are different.  

Is there any option to make the analysis / pointsTo-set more precise?

 

I am using soot 2.5 and the following options:

//Soot:

             Options.v().set_keep_line_number(true);

             Options.v().set_app(true);

             Options.v().set_xml_attributes(true);

             Options.v().set_whole_program(true);

 

             PhaseOptions.v().setPhaseOption("jb" ,
"use-original-names:true"); // use original names

             PhaseOptions.v().setPhaseOption("jb.ulp" , "enabled:false"); //
do not minimize the number of stack variables

             PhaseOptions.v().setPhaseOption("jj" ,
"use-original-names:true");

             PhaseOptions.v().setPhaseOption("jj.ulp" , "enabled:false");

             PhaseOptions.v().setPhaseOption("jj.a",
"only-stack-locals:false");

 

             //Spark:

             Options.v().setPhaseOption("cg","implicit-entry:false");

             Options.v().setPhaseOption("cg.spark","enabled:true");

             

             //explicit:

             Options.v().setPhaseOption("cg.spark","field-based:false");

             Options.v().setPhaseOption("cg.spark","types-for-sites:false");

             

             

             if(IN_DEBUG_MODE){

 
soot.options.Options.v().setPhaseOption("cg.spark","verbose:true");

             }

 

I tried the field-based options, but it does not matter if the option is
true or false. The outcome is the same.  

 

Do you have any ideas?

 

 

Best regards,

       Florian

 

 

Btw. I am not able to access the website any more:
http://www.sable.mcgill.ca/

Is this a local problem or did someone else notice it?

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