[llvm-dev] [lld] - LLD (ELF) code covered by test cases.

[Rafael Avila de Espindola via llvm-dev]

Thanks a lot for doing this.

Having it automated an in a bot would be really nice.

Cheers,
Rafael

George Rimar <grimar at accesssoftek.com> writes:

> Hello guys,
>
> Today I tried to find the amount of LLD(elf) code covered by our test cases. So my aim was to run the LLD tests we have (run check-lld task) and find out which code was executed/covered and which was not.
>
> I used the approach from the next article to do that:
> http://logan.tw/posts/2015/04/28/check-code-coverage-with-clang-and-lcov/#create-a-wrapper-script-for-lcov
>
> In short, it is based on using -fprofile-arcs -ftest-coverage clang flags and then generating the HTML report using lcov and genhtml tools.
>
> The results are actually not that bad (I expected we would have much more issues, but glad to see we seem don't :)
> Coverage screenshot:
> https://drive.google.com/file/d/1rjFdMA0HOjvz4vw_nDttv_dlbMiNYiaw/view
>
> We have few problematic places, but generally seems we cover the most of the code, except the few specific
> errors and conditions. The full HTML report is available here:
> https://drive.google.com/file/d/1ROo9rZ4p7-IT68jI0nnhNMOqPNpk1l0c/view?usp=sharing
>
> Noticeable places I have to mention though are (we have some large code parts uncovered):
>
> 1) I was able to place `assert(false);` on line 386 below in ICF.cpp and all our tests pass.
> (https://github.com/llvm-mirror/lld/blob/master/ELF/ICF.cpp#L386)
>
> 2) In Relocations.cpp, all code inside `if`:
> https://github.com/llvm-mirror/lld/blob/master/ELF/Relocations.cpp#L1177
> Is not covered by tests.
>
> 3) MicroMipsR6Thunk::writeTo(), MicroMipsR6Thunk::addSymbols(),
> MicroMipsR6Thunk::getTargetInputSection() are not covered.
>
> That seems to be all major places I saw in report.
>
> Now we probably can think about what we can do with that?
> * Ideal scenario I can imagine is that we could fix all the places and, for example, setup the watching bot
> looking for LLD code coverage for each commit.
> * Minimal scenario I see is to fix the major known places mentioned at least.
>
> What do you think guys??
>
>
> Best regards,
> George | Developer | Access Softek, Inc