[PATCH] rtems-tools/covoar: Wrong coverage computed

[Vijay Kumar Banerjee]

On Fri, 25 Jan 2019 at 23:39, Joel Sherrill <joel at rtems.org> wrote:

> Sorry for the duplicate email. I didn't use the right email address and
> the response did not go to devel@
>
> On Fri, Jan 25, 2019 at 8:43 AM Jiri Gaisler <jiri at gaisler.se> wrote:
>
>> Sorry for the noise, but I have a better patch that actually solves the
>> root problem. I ran the full testsuite on sis and covoar against libscore.a
>> like this:
>>
>> $ sparc-rtems5-ar -rcs sparc-rtems5/c/leon3/cpukit/score/libscore.a
>> sparc-rtems5/c/leon3/cpukit/score/src/*.o
>>
>> $ rtems-test --rtems-bsp=leon3-sis-cov sparc-rtems5/c/leon3/testsuites
>>
>> $ /opt/rtems/5/share/rtems/tester/bin/covoar -v -f TSIM -S
>> /opt/rtems/5/share/rtems/tester/rtems/testing/coverage/score-symbols.ini -O
>> coverage -E
>> /opt/rtems/5/share/rtems/tester/rtems/testing/coverage/Explanations.txt -p
>> RTEMS-5  sparc-rtems5/c/leon3/testsuites/*/*.exe
>>
>> summary.txt:
>>
>> Bytes Analyzed           : 39376 Bytes Not Executed       : 2864
>> Percentage Executed      : 92.73 Percentage Not Executed  : 7.273 Uncovered
>> ranges found   : 108 Total branches found     : 860 Uncovered branches
>> found : 200    61 branches always taken    139 branches never taken
>>
>> All symbol sizes and ranges are now correctly reported/calculated in the
>> reports. There are two remaining issues to be solved:
>>
>> 1. File names are printed as 'unknown' in reports (minor problem but
>> useful)
>>
> Originally we got the info via the binutils command line tools. I think
> the
> filename came from addr2line. When we designed it originally, Ian Lance
> Taylor said parsing the tool output was more easier, reliable, and more
> stable than tracking any elf reading library.
>
> But it was slower than accessing the data directly via ELF and DWARF.
> Since Chris added this support for the dynamic loader, it was natural to
> begin to replace that code. Unfortunately, there are some warts left from
> the transition. The name may be one of them.
>
> We also think the beginning and end of a method are not marked properly.
>
> And when something is inlined, it isn't considered part of the main method.
> The original method considered assembly from inlined code part of the
> caller. It is now reported as part of the callee. We have identified a
> needed
> change to (1) account for the inlined assembly as part of the caller and
> (2) add additional tracking of the coverage of inlined methods.
>
> The immediate need is to get the reporting so it accurately annoates
> the generated assembly from a method and anything inlined into it.
> This should let us do DO-178 Level A style coverage -- we are
> sure we use ever instruction and take/not take every branch.
>
> Hello,
This is awesome to have the sis support in covoar, the very next thing that
comes to my mind is adding the '-f' option in the rtems-test coverage
script,
this will enable us to get the HTML reports.

The issues noted here, can make a very good project for GSoC and I was
hoping to work on them, but there is a good amount of complexity involved,
and I am confused where to get started. :)

If there is unreachable code or branches where both paths are not
> exercised, we need tests to exercise them OR the code is useless
> and can be removed. Either way, we win.
>
>> 2. We should add RISC-V support to covoar ...
>>
>
> I am sure you have seen the Target* files. They are not large. Some is
> trivial. Other parts are to recognize nops and branch instruction
> variants.
>
> Is the workflow something like this ...
1. write Target_ARCH.cc
2. Add it to the TargetFactory
3. Add ini file in the tools .

I have a question. Is there some reason that the files in covoar/ don't
have a
copyright notice?

 On a RISC architecture, I wouldn't expect a lot of variation in nops.
> The x86 has an awful set that range in size. :(
>
> Let me know if you agree to the patch ..
>>
>
> The patch looks good to me.
>
>> _______________________________________________
>> devel mailing list
>> devel at rtems.org
>> http://lists.rtems.org/mailman/listinfo/devel
>
>
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