[Soot-list] Type inference in Soot for Java polymorphism?

[Yi Lin]

Thanks very much. That is very helpful.

I read some documents about SPARK. However I am having some problems 
using SPARK with my code.

1. I used to only use Soot to resolve classes, and I didn't run any 
transformation or optimizations by Soot. However, it seems if I want 
points-to analysis result from SPARK, I would have to run 
soot.Main.main(), which involves all transformations and optimizations. 
This not only takes a quite long time, but also is undesirable. How can 
I very 'cleanly' get the points-to analysis from SPARK? (I will attach 
the code I am running with at the end of this email, which was found 
from the mail-list archives)

2. After I added those code to run SPARK, I am not able to retrieve any 
method body. The pseudo-code for my program is like,

         (1)initSootOptions();
         (2)resolveClassesThatINeed();
         (3)walkThroughThoseClasses();

But after I add 'runSPARK()' after (1) or (2), in (3) it failed to get 
method body.

    java.lang.NullPointerException
         at soot.SootMethod.getBodyFromMethodSource(SootMethod.java:89)
         at soot.SootMethod.retrieveActiveBody(SootMethod.java:322)

Sorry if those questions sound naive. I quickly went through Ondrej's 
SPARK thesis, I got Soot survivor guide with me, I searched through mail 
list. But I am still quite lost.

Thank you very much.

Regards,
Yi

the code that I am running SPARK with:

    runSPARK() {
             List<String> sootArgs = new ArrayList<String>();
             sootArgs.add("-W");
             sootArgs.add("-p");
             sootArgs.add("wjop");
             sootArgs.add("enabled:true");

             //enable points-to analysis
             sootArgs.add("-p");
             sootArgs.add("cg");
             sootArgs.add("enabled:true");

             //enable Spark
             sootArgs.add("-p");
             sootArgs.add("cg.spark");
             sootArgs.add("enabled:true");

             PackManager.v().getPack("wjop").add(new
    Transform("wjop.mytrans",new SceneTransformer() {
                  protected void internalTransform(String phaseName, Map
    options) {
                      System.out.println("SPARK pointer-to analysis...");
                      HashMap map = new HashMap(options);
                      //set the PointsToAnalysis with phase options
                      map.put("verbose", "true");
                      map.put("propagator", "worklist");
                      map.put("simple-edges-bidirectional", "false");
                      map.put("on-fly-cg", "true");
                      map.put("set-impl", "hybrid");
                      map.put("double-set-old", "hybrid");
                      map.put("double-set-new", "hybrid");
                      SparkTransformer.v().transform("",map);
                  }
                }));

             soot.Main.main(sootArgs.toArray(new String[0]));
    }


On 22/01/13 16:09 , Richard Xiao wrote:
> Of course, try SPARK, the points-to analysis in soot. You will obtain 
> a list of objects "cat" can point to. Compute the lowest common 
> ancestor of the types of these pointed to objects, that's the answer.
>
>
> On Tue, Jan 22, 2013 at 10:56 AM, Yi Lin <qinsoon at gmail.com 
> <mailto:qinsoon at gmail.com>> wrote:
>
>     Hi,
>
>     For example.
>
>     For Java code,
>          Animal cat = new Cat();
>          cat.speak();
>
>     Jimple code is like,
>     Locals:
>          [Animal]cat
>          [Cat]temp$0
>     Code:
>          temp$0 = new Cat
>          specialinvoke temp$0.<Cat: void <init>()>()
>          cat = temp$0
>          virtualinvoke cat.<Animal: void speak()>()
>
>     Is it possible for Soot to tell that the variable 'cat' actually
>     holds a
>     'Cat' object instead of an 'Animal'?
>
>     If not, is it possible for me to implement such analysis on Soot
>     framework (especially for inter-procedure cases)? Without using
>     dynamic
>     loading in the Java code, and with whole program analysis turned on in
>     Soot, I assume it should be possible to do such type inference.
>
>     Any idea would be appreciated. Thank you very much.
>
>     Regards,
>     Yi
>     _______________________________________________
>     Soot-list mailing list
>     Soot-list at sable.mcgill.ca <mailto:Soot-list at sable.mcgill.ca>
>     http://mailman.cs.mcgill.ca/mailman/listinfo/soot-list
>
>
>
>
> -- 
> Richard Xiao Xiao
> PhD Student @ CSE @ Hong Kong University of Science and Technology
> www.cse.ust.hk/~richardxx <http://www.cse.ust.hk/%7Erichardxx>

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