Re: [PATCH] kunit: tool: show list of valid --arch options when invalid

[David Gow <davidgow@google.com>]

On Thu, Sep 30, 2021 at 7:26 AM Daniel Latypov <dlatypov@google.com> wrote:
>
> Consider this attempt to run KUnit in QEMU:
> $ ./tools/testing/kunit/kunit.py run --arch=x86
>
> Before you'd get this error message:
> kunit_kernel.ConfigError: x86 is not a valid arch
>
> After:
> kunit_kernel.ConfigError: x86 is not a valid arch, options are ['alpha', 'arm', 'arm64', 'i386', 'powerpc', 'riscv', 's390', 'sparc', 'x86_64']
>
> This should make it a bit easier for people to notice when they make
> typos, etc. Currently, one would have to dive into the python code to
> figure out what the valid set is.
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> ---

This is really nice, particularly given that we've had to reproduce
that list in lots of talks, documentation, etc. and it could get
out-of-date.

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

[FYI: this didn't seem to apply cleanly to kselftest/kunit head, but
it was a pretty minor issue with kunit_tool_test.py.]

Thanks,
-- David

>  tools/testing/kunit/kunit_kernel.py    | 5 +++--
>  tools/testing/kunit/kunit_tool_test.py | 4 ++++
>  2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
> index 1870e75ff153..a6b3cee3f0d0 100644
> --- a/tools/testing/kunit/kunit_kernel.py
> +++ b/tools/testing/kunit/kunit_kernel.py
> @@ -198,8 +198,9 @@ def get_source_tree_ops(arch: str, cross_compile: Optional[str]) -> LinuxSourceT
>                 return LinuxSourceTreeOperationsUml(cross_compile=cross_compile)
>         elif os.path.isfile(config_path):
>                 return get_source_tree_ops_from_qemu_config(config_path, cross_compile)[1]
> -       else:
> -               raise ConfigError(arch + ' is not a valid arch')
> +
> +       options = [f[:-3] for f in os.listdir(QEMU_CONFIGS_DIR) if f.endswith('.py')]
> +       raise ConfigError(arch + ' is not a valid arch, options are ' + str(sorted(options)))
>
>  def get_source_tree_ops_from_qemu_config(config_path: str,
>                                          cross_compile: Optional[str]) -> Tuple[
> diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
> index cad37a98e599..2ae72f04cbe0 100755
> --- a/tools/testing/kunit/kunit_tool_test.py
> +++ b/tools/testing/kunit/kunit_tool_test.py
> @@ -289,6 +289,10 @@ class LinuxSourceTreeTest(unittest.TestCase):
>                                 pass
>                         kunit_kernel.LinuxSourceTree('', kunitconfig_path=dir)
>
> +       def test_invalid_arch(self):
> +               with self.assertRaisesRegex(kunit_kernel.ConfigError, 'not a valid arch, options are.*x86_64'):
> +                       kunit_kernel.LinuxSourceTree('', arch='invalid')
> +
>         # TODO: add more test cases.
>
>
>
> base-commit: 865a0a8025ee0b54d1cc74834c57197d184a441e
> --
> 2.33.0.685.g46640cef36-goog
>