[llvm-dev] ArrayBoundChecks in SafeCode-llvm37

[Syed Rafiul Hussain via llvm-dev]

I have fixed the BottomUpCallGrap pass (in ArrayBoundChecks) for
LLVM-3.8 to make the call graph.

I will clean up my mess in the DSA and upload it to somewhere soon.

Thanks,
Syed

On Thu, Apr 28, 2016 at 10:18 PM, John Criswell <jtcriswel at gmail.com> wrote:
> On 4/28/16 8:43 PM, Syed Rafiul Hussain wrote:
>>
>> Thanks Professor Criswell for your reply.
>
>
> You're welcome.  Please keep replies on the list so that others can track
> and add to the conversation.
>
>>
>> I just need the constraintGeneration pass (i.e., interprocedural
>> constraint generation pass) of ArrayBoundChecks.
>
>
> The constraint generation code is really old.  It will need some significant
> work to get it working again.  There is also the question of whether it is
> better to generate constraints for Omega (the linear solver from Bill Pugh's
> group, IIRC) or whether generating constraints for CVC4 or Z3 would be
> better (I suspect Omega uses a better algorithm, but CVC4 and Z3 are better
> maintained; one could also adapt Omega to CVC4 if desired).
>
>
>>   I have the DSA
>> updated to LLVM 3.8 already.
>
>
> Cool.  Can you put that into a Github repo somewhere?  Other people are
> wanting DSA for LLVM 3.8.
>
>>   More specifically, I want to find out the
>> post dominance frontier (pdf) for a particular basic block. I can find
>> the pdf for a function. But, I need the pdf up to the main.entry.
>
>
> Constraint generation is not needed for computing the post-dominance
> frontier.  You simply need to use the call graph from either DSA or the LLVM
> Call Graph pass and compute the post dominance frontier on your own.  It
> shouldn't be too difficult to implement, though call graph precision for
> code with function pointers could be an issue.
>
> The old constraint generation code generates constraints for values that are
> stored in memory.  It won't help compute an inter-procedural dominance
> frontier.
>
> Regards,
>
> John Criswell
>
>>
>> Sincerely,
>> Syed
>>
>>
>>
>>
>> On Thu, Apr 28, 2016 at 7:41 PM, John Criswell <jtcriswel at gmail.com>
>> wrote:
>>>
>>> On 4/27/16 12:00 PM, Syed Rafiul Hussain via llvm-dev wrote:
>>>>
>>>> Hi,
>>>>
>>>> I am wondering if anyone could run ArrayBoundChecks located in
>>>> SafeCode-llvm37 (https://github.com/jtcriswell/safecode-llvm37) on
>>>> llvm-3.8?
>>>
>>>
>>> As the 3.7 port isn't complete, I would guess that the answer is no.
>>> :)
>>>
>>> Within that directory, which pass do you need?  The BreakConstantGEPs.cpp
>>> pass would be easy to get working with LLVM 3.8 (note: in general, I
>>> don't
>>> recommend using this pass, but there are rare situations for which it is
>>> needed).
>>>
>>> ArrayBoundsCheckLocal would probably be easy. ArrayBoundsCheckStruct
>>> should
>>> be easy if you have DSA updated to LLVM 3.8.
>>>
>>> The omega-based static array bounds checking code has long bitroted, and
>>> it's design could use significant improvement.  That code executed the
>>> omega
>>> program for every array it checked.  A more efficient implementation
>>> would
>>> link the constraint solver in as a library and query it via a function
>>> call.
>>>
>>> If you can explain in more detail what you need, I can provide advice on
>>> what I think your best path forward will be.
>>>
>>> Regards,
>>>
>>> John Criswell
>>>
>>>> Thanks.
>>>> Syed
>>>>
>>>
>>> --
>>> John Criswell
>>> Assistant Professor
>>> Department of Computer Science, University of Rochester
>>> http://www.cs.rochester.edu/u/criswell
>>>
>>
>>
>
>
> --
> John Criswell
> Assistant Professor
> Department of Computer Science, University of Rochester
> http://www.cs.rochester.edu/u/criswell
>



-- 
Rafi