[Soot-list] relevance analysis

[Marc-André Laverdière]

Hi Mohammad,

Knowing read/write is trivial. Just look at the AssignStmt left and
right ops. If the FieldRef is on the left, that's a write, if it is in
the right, that's a read.

The only trick you need to be careful with is that Jimple requires local
variables to store field references, so an operation that is
obj.field1 = obj.field2 is two operations in Jimple:

tmp = obj.field2
obj.field1 = tmp

As for flowdroid, you can have a look in the code on stuff related to
taint wrappers, https://github.com/secure-software-engineering/soot-infoflow

Marc-André Laverdière-Papineau
Doctorant - PhD Candidate

On 05/04/2014 05:42 PM, Mohammad Ghafari wrote:
> 
> Hi Marc-André,
> 
> Yes, the bytecode is available at the end. Given that example, I wanted
> to ask whether I should dive into the implementation of an ArrayList to
> know if there is a read or write (please note that knowing filed-access
> is not enough to me and should know whether it is a read or write)?
> For example, if I do a linear pass over jimple representation of Method1
> will that show there is a _write_ operation to col field?
> 
> p.s., Where can I find more info about "domain knowledge" in flowdroid?
> 
>  
> 
> 
> On Sun, May 4, 2014 at 10:52 PM, Marc-André Laverdière
> <marc-andre.laverdiere-papineau at polymtl.ca
> <mailto:marc-andre.laverdiere-papineau at polymtl.ca>> wrote:
> 
>     Hi Mohammad,
> 
>     I am not sure I understand your question.
>     We totally have the source code for those methods. Its called OpenJDK.
>     But even if we didn't, Soot can read bytecode pretty decently and allow
>     you to do whatever you want.
> 
>     But you may still take a short-cut by using 'domain knowledge', as we
>     have been doing in flowdroid. You can have a look a the taint
>     wrappers :)
> 
>     As a general thing, in order to do what you want, you just need to do a
>     linear pass over your program to record field access. Or you can query
>     Spark, but you're not necessarily required to get a call graph to do
>     this.
> 
>     Marc-André Laverdière-Papineau
>     Doctorant - PhD Candidate
> 
>     On 05/04/2014 07:15 AM, Mohammad Ghafari wrote:
>     >
>     > Hello everybody,
>     >
>     > I want to find if two methods are related, i.e., they read
>     from/write to
>     > the same field. For example:
>     >
>     >  List<String> col = new ArrayList<String>();
>     >
>     >  Method1(){
>     >   col.put("item");
>     >  }
>     >
>     >  Method2(){
>     >   col.get();
>     >  }
>     >
>     > Intuitively, these two methods are related because the first method
>     > write to a list from which the second method reads. However, as we
>     don't
>     > have the source code of java libraries like List, how can I use
>     Soot to
>     > know that col.put() writes to col while col.get() reads from this
>     list?
>     >
>     > Thnaks
>     >
>     >
>     >
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> 
> 
> 
> -- 
> Mohammad Ghafari
> 
> DeepSE group @ DEIB - Politecnico di Milano
> http://home.deib.polimi.it/ghafari