[llvm-dev] Compiling program with dfsan at IR

[Archa . via llvm-dev]

Thank you that worked in removing the undefined reference errors for the
dfsan related functions like __dfsan*. But I make use of some libc
functions like printf, and the error persists for such functions: undefined
reference to `dfs$printf'.

Thanks


Thanks and Regards
Archa



On Sat, Jun 3, 2017 at 12:43 PM, Peter Collingbourne <peter at pcc.me.uk>
wrote:

> Try passing -relocation-model=pic at step 4.
>
> Peter
>
> On Sat, Jun 3, 2017 at 2:19 AM, Archa . <archa91 at gmail.com> wrote:
>
>> I tried running step 5 with clang -fsanitize=dataflow instead of gcc but
>> it gave the following error:
>>
>> relocation R_X86_64_32 against `desc' can not be used when making a
>> shared object; recompile with -fPIC
>> error adding symbols: Bad value
>> clang-5.0: error: linker command failed with exit code 1 (use -v to see
>> invocation)
>>
>> So I also tried adding -fPIC option at step 1 when converting .c program
>> to .bc and still results in same error. Is there anything else I may be
>> missing here.
>>
>> Thanks
>>
>>
>>
>> On Fri, Jun 2, 2017 at 9:25 PM, Peter Collingbourne <peter at pcc.me.uk>
>> wrote:
>>
>>> Programs compiled with dfsan require a runtime library in order to work
>>> correctly. You will need to link your program with "clang
>>> -fsanitize=dataflow".
>>>
>>> Peter
>>>
>>> On Fri, Jun 2, 2017 at 12:46 AM, Archa . via llvm-dev <
>>> llvm-dev at lists.llvm.org> wrote:
>>>
>>>> Hi,
>>>>
>>>> I am trying to instrument a small program with dfsan at IR and then
>>>> compile it. But I end up with undefined reference errors.
>>>>
>>>> Steps taken:
>>>> 1.Convert toy program to .bc
>>>> 2. IR pass to insert dfsan calls
>>>> 3.opt -dfsan on resultant bitcode from step 2
>>>> 4. llc step3.bc -o step4.s
>>>> 5. gcc step.s -o step5.o
>>>>
>>>> I get error  "undefined reference to `__dfsan_arg_tls' " and so forth
>>>> for all functions defined.
>>>> Is there something I am missing or doing wrong in my steps.
>>>>
>>>> Thanks
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> LLVM Developers mailing list
>>>> llvm-dev at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>>
>>>>
>>>
>>>
>>> --
>>> --
>>> Peter
>>>
>>
>>
>
>
> --
> --
> Peter
>
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