[LLVMdev] indirect calls tracking and control flow graph

[John Criswell]

On 4/28/14 11:59 AM, Amara Emerson wrote:
> Hi Thanasis,
>
> You should be able to do this easily by writing a FunctionPass (see
> http://llvm.org/docs/WritingAnLLVMPass.html for more info) and
> iterating over the instructions in the function, searching for
> CallInst instructions and using getCalledFunction() to check if it's
> indirect.

This will allow you to determine whether a call is an indirect function 
call, but it won't give you the targets of the indirect function calls.  
To get the targets, you need to use a CallGraph analysis (like the one 
in DSA).

Regards,

John Criswell

>
> Amara
>
> On 28 April 2014 14:10, Petsas Athanasios <petsas at ics.forth.gr> wrote:
>> Dear all,
>>
>> I would like to keep track of all the indirect calls that may caused from
>> function
>> pointers inside a program. I need this in order to be able to construct the
>> control
>> flow graph of all the indirect calls, that is which function is legal to
>> call another
>> function.
>>
>> Is there a module that implements this functionality in llvm? If not, is
>> there a way to
>> do it? Maybe through implementing a pass. I am new to llvm. Could you
>> suggest me
>> a way to start doing this? Perhaps the llvm intermediate code can help me on
>> this.
>> Do you know where this code is being produced? or what files or passes do I
>> have
>> to modify for this?
>>
>> Until now I have used this command to produce and study the llvm bitcode for
>> a test
>> program:
>> clang -S -emit-llvm fpointers.c -c -o fpointers.bc.text
>>
>> Thank you,
>>
>> --
>> Thanasis Petsas
>> Distributed Computing Systems (DCS)
>> Institute of Computer Science (ICS/FORTH)
>> Heraklion, Crete
>> Greece (GR)
>>
>> http://www.thanasispetsas.com/
>>
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