[Soot-list] Question about Shimple

[Hamid A. Toussi]

Hi all,
Obviously, Jimple has many advantages of a SSA representation but it
does not create any phi-node:
http://www.sable.mcgill.ca/pipermail/soot-list/2012-July/004586.html

I would also like to know what other features Shimple introduces (in
addition to phi-nodes)?

Hamid

On Thu, Feb 21, 2013 at 4:25 PM, Zeinab Lashkaripour
<lashkaripour at yahoo.com> wrote:
> Hi Marc-Andre,
> Thanks for your nice response.
> You asked some good questions that I hope we get the answers to them.
>
> Regards,
> Zeinab
>
> ________________________________
> From: Marc-Andre Laverdiere-Papineau
> <marc-andre.laverdiere-papineau at polymtl.ca>
> To: soot-list at sable.mcgill.ca
> Sent: Thursday, February 21, 2013 4:07 PM
> Subject: Re: [Soot-list] Question about Shimple
>
> Hello,
>
> I am not conversant in the details of Shimple, but the big picture is
> that Shimple is a SSA representation, meaning that each variable has
> only one assignment. That obviously means that the flow of data is much
> easier to track.
>
> There are old research results that indicate that SSA representations
> give you a much higher level of precision (almost at the level of
> context sensitivity) without a significant increase in the cost in
> processing. I don't remember the reference, but it is in Lhotak's
> masters thesis.
>
> Obviously, you hit some of that cost up-front for transforming into SSA
> form :)
>
> I have a question for the McGillites - how well supported is shimple
> with the rest of soot? I see that recent improvements have all been in
> the Jimple form (geometric pta, Heros). Are the call graph algorithms
> and other transformations working well with Shimple? Is it that the
> benefits were not as big as expected?
>
> I noticed that Wala and a few research papers on static analysis I read
> are using SSA (and even e-SSA) representations.
>
> Is there good technical reasons to guide us in choosing Jimple vs
> Shimple? I wouldn't mind a nice little decision tree ;)
>
>
> Marc-André Laverdière-Papineau
> Doctorant - PhD Candidate
>
> On 13-02-21 03:46 AM, Zeinab Lashkaripour wrote:
>> Hi dear Reader,
>>
>> I have a question that I would be grateful if you answered:
>> I'm working with Jimple but, the question below came to my mind and I
>> didn't find the answer to it so I decided to get help from the list.
>> For shimple in order to get the UD or DU chains there is no need to
>> implement the DFA analysis (I mean the flowthrough, merge, copy, ...)
>> because we can obtain this information by ShimpleLocalDefs/Uses, Is that
>> right?
>>
>> Maybe one of the reasons that we are said Shimple makes analysis (flow
>> control sensitive) simple is this.
>>
>> Regards,
>> Zeinab
>>
>>
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