[llvm-dev] Compiling program with dfsan at IR

[Peter Collingbourne via llvm-dev]

Try passing -dfsan-abilist=$path at step 3. You can get $path by looking at
output of "clang -fsanitize=dataflow -c input.c -###".

In general try to fix problems with steps 1-4 by comparing what you are
doing with what "clang -fsanitize=dataflow -c" is doing.

Peter

On Sat, Jun 3, 2017 at 4:42 AM, Archa . <archa91 at gmail.com> wrote:

> 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
>>
>
>


-- 
-- 
Peter
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