gcov support in Covoar

[Vijay Kumar Banerjee]

On 14 May 2018 at 23:37, Joel Sherrill <joel at rtems.org> wrote:

>
>
> On Mon, May 14, 2018 at 12:43 PM, Vijay Kumar Banerjee <
> vijaykumar9597 at gmail.com> wrote:
>
>> On 14 May 2018 at 21:21, Joel Sherrill <joel at rtems.org> wrote:
>>
>>>
>>>
>>> On Mon, May 14, 2018 at 10:19 AM, Vijay Kumar Banerjee <
>>> vijaykumar9597 at gmail.com> wrote:
>>>
>>>> Hello,
>>>>
>>>> The coverage report is showing some data now (txt only). There is still
>>>> some work needed to be done for it to get merged with the main repo. As it
>>>> depends on the ongoing work on the covoar.cc and coverage.py, meanwhile I
>>>> want to get started with the gcov support in covoar as I already have some
>>>> coverage data in txt format to compare with .
>>>>
>>>> I would like to know the following points to get started:
>>>>
>>>>     1. What is the current state of the gcov support in covoar. I can
>>>> see work on GcovData and GcovFunction data in covoar, what's the current
>>>> status of it ?
>>>>
>>>
>>> Technically unknown, potentially bit rotted.
>>>
>> Seems like it will take some time before it starts making sense .
>>
>
> Maybe. Since you can produce coverage reports now, I am betting it
> will likely work quickly. :)
>
Hopefully.

>
>
>>
>>
>>>
>>>
>>>>
>>>>     2. Did it use to run at some point? seeing it in action will be
>>>> very helpful.
>>>>
>>>
>>> It used to produce .gcov files that could be processed by gcov and
>>> produce reports.
>>>
>> Then our very first objective is to get the .gcov file output only then
>> can we proceed with the  discripancies
>>
>
> Yes.
>
> Use the same test executables and symbols of interest.
>
> I suspect you have been looking at a report for the same test exe and the
> same methods.
> Just check that the report from gcov matches. If it doesn't, then we have
> a small test case.
>
Yeah that will be the approach.

>
>
>>
>>> Once you started to compare the reports to the native reports from
>>> covoar, you would sometimes see places that covoar thought some code was
>>> executed that did not show up in the gcov generated report. When I
>>> investigated, I got far enough to know we had executed the code in question.
>>>
>>>
>>>>
>>>>     3. What are the listed blockers rn ? Other than the reliability of
>>>> the report .
>>>>
>>>
>>> That's it. Get it working and then let's work on automation, use of
>>> lcov, etc. Along the way, I am sure we will spot the difference in
>>> reporting. Then that will have to be fixed.
>>>
>>>
>>>>     4. are there any tickets related to gcov?
>>>>
>>>
>>> Not from RTEMS' perspective.
>>>
>>> One challenge we had previously is that the .gcov file format was only
>>> documented in the header file. That was why I asked for someone from the
>>> gcc community to help us once we spot difference. Hopefully they can help
>>> us figure out what is wrong with the file covoar is producing.
>>>
>>
>>>> Please add any suggestions or references that might help me get started
>>>> properly .
>>>>
>>>
> https://gcc.gnu.org/onlinedocs/gcc/Gcov-Data-Files.html is an overview
> from a gcc user's perspective.
>
> The details are in the gcc source code. This should be the current version
> of the gcov file:
>
> https://github.com/gcc-mirror/gcc/blob/master/gcc/gcov-io.h
>
Thanks for the links

>
>
> I don't remember a comment in the version in covoar specifying that the
> format could change
> with GCC versions. Maybe that's the gcno data and not the coverage data.
>
> This needs to be looked into properly to undertsand how the versions
impact the report generation.

> Randomly found this tool which looks like another option for more
> reports/analysis once gcov
> files are available:
>
> https://gcovr.com/guide.html
>
>
it says XML reports!
Looks like we have some cool options to try out once we get the initial
steps done.

>
>>>> Thank you,
>>>>
>>>
> R
>
>>
>>>> Vijay
>>>>
>>>>
>>>>
>>>
>>
>
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