[PATCH 2/2] Documentation: kunit: Add clang UML coverage example

[David Gow]

On Fri, 20 Oct 2023 at 17:22, Michał Winiarski
<michal.winiarski at intel.com> wrote:
>
> LLVM-based toolchain is using a different set of tools for coverage.
> Add an example that produces output in lcov format.
>
> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
> ---

This looks good to me, minus a couple of very, very minor typos, and
the fact that this whole section could probably do with some tidying
up. We'll deal with that separately, though.

UML folks: do you want to take this via the UML branch (alongside
patch 1), or should we take one or both of them via KUnit? (Or, this
could go via the docs tree, too, I suppose.) There shouldn't be any
merge conflicts on our side.

Reviewed-by: David Gow <davidgow at google.com>

Cheers,
-- David

>  Documentation/dev-tools/kunit/running_tips.rst | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
> index 766f9cdea0fa..9f69c122dee7 100644
> --- a/Documentation/dev-tools/kunit/running_tips.rst
> +++ b/Documentation/dev-tools/kunit/running_tips.rst
> @@ -139,6 +139,17 @@ If your installed version of gcc doesn't work, you can tweak the steps:
>         $ ./tools/testing/kunit/kunit.py run --make_options=CC=/usr/bin/gcc-6
>         $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/ --gcov-tool=/usr/bin/gcov-6
>
> +Alternatively, LLVM-based toolchain can also be used:

Nit: should this be "an LLVM-based toolchain" or "LLVM-based toolchains"?

> +
> +.. code-block:: bash
> +
> +       # Build with LLVM and append coverage options to the current config
> +       $ $ ./tools/testing/kunit/kunit.py run --make_options LLVM=1 --kunitconfig=.kunit/ --kunitconfig=tools/testing/kunit/configs/coverage_uml.config

I'm not a big fan of the --kunitconfig=.kunit/ bit here, but since
we're doing it in the gcc version above, let's leave it for now for
consistency.

Also, Nit: two '$' starting the line.


> +       $ llvm-profdata merge -sparse default.profraw -o default.profdata
> +       $ llvm-cov export --format=lcov .kunit/vmlinux -instr-profile default.profdata > coverage.info
> +       # The coverage.info file is in lcov-compatible format and it can be used to e.g. generate HTML report
> +       $ genhtml -o /tmp/coverage_html coverage.info
> +
>
>  Running tests manually
>  ======================
> --
> 2.42.0
>
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