Add ability to kunit.py to filter attributes and report a list of tests
including attributes without running tests.

Add flag "--filter" to input filters on test attributes. Tests will be
filtered out if they do not match all inputted filters.

Example: --filter speed=slow (This filter would run only the tests that are
marked as slow)

Filters have operations: <, >, <=, >=, !=, and =. But note that the
characters < and > are often interpreted by the shell, so they may need to
be quoted or escaped.

Example: --filter "speed>slow" or --filter speed\>slow (This filter would
run only the tests that have the speed faster than slow.

Additionally, multiple filters can be used.

Example: --filter "speed=slow, module!=example" (This filter would run
only the tests that have the speed slow and are not in the "example"
module)

Note if the user wants to skip filtered tests instead of not
running/showing them use the "--filter_action=skip" flag instead.

Expose the output of kunit.action=list option with flag "--list_tests" to
output a list of tests. Additionally, add flag "--list_tests_attr" to
output a list of tests and their attributes. These flags are useful to see
tests and test attributes without needing to run tests.

Example of the output of "--list_tests_attr":
  example
  example.test_1
  example.test_2
  # example.test_2.speed: slow

This output includes a suite, example, with two test cases, test_1 and
test_2. And in this instance test_2 has been marked as slow.

Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Basically, get this command to be happy and make run_checks.py happy
 $ mypy --strict --exclude '_test.py$' --exclude qemu_configs/ ./tools/testing/kunit/

Primarily the changes are
* add `-> None` return type annotations
* add all the missing argument type annotations

Previously, we had false positives from mypy in `main()`, see commit
09641f7c7d8f ("kunit: tool: surface and address more typing issues").
But after commit 2dc9d6ca52a4 ("kunit: kunit.py extract handlers")
refactored things, the variable name reuse mypy hated is gone.

Note: mypy complains we don't annotate the types the unused args in our
signal handler. That's silly.
But to make it happy, I've copy-pasted an appropriate annotation from
https://github.com/python/typing/discussions/1042#discussioncomment-2013595.

Reported-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/linux-kselftest/9a172b50457f4074af41fe1dc8e55dcaf4795d7e.camel@sipsolutions.net/
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

We don't run a linter regularly over kunit.py code (the default settings
on most don't like kernel style, e.g. tabs) so some of these imports
didn't get removed when they stopped being used.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The main function contains a wide if-elif block that handles different
subcommands. It's possible to make code refactoring to extract
subcommands handlers.

Fixed commit summary line.
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: Alexander Pantyukhin <apantykhin@gmail.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The build_tests function contained double checking for not success
result. It is fixed in the current patch. Additional small
simplifications of code like using ternary if were applied (avoid using
the same operation by calculation times differ in two places).

Signed-off-by: Alexander Pantyukhin <apantykhin@gmail.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Currently, kunit_parser.py is stripping all leading whitespace to make
parsing easier. But this means we can't accurately show kernel output
for failing tests or when the kernel crashes.

Embarassingly, this affects even KUnit's own output, e.g.
[13:40:46] Expected 2 + 1 == 2, but
[13:40:46] 2 + 1 == 3 (0x3)
[13:40:46] not ok 1 example_simple_test
[13:40:46] [FAILED] example_simple_test

After this change, here's what the output in context would look like
[13:40:46] =================== example (4 subtests) ===================
[13:40:46] # example_simple_test: initializing
[13:40:46] # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29
[13:40:46] Expected 2 + 1 == 2, but
[13:40:46]     2 + 1 == 3 (0x3)
[13:40:46] [FAILED] example_simple_test
[13:40:46] [SKIPPED] example_skip_test
[13:40:46] [SKIPPED] example_mark_skipped_test
[13:40:46] [PASSED] example_all_expect_macros_test
[13:40:46]     # example: initializing suite
[13:40:46] # example: pass:1 fail:1 skip:2 total:4
[13:40:46] # Totals: pass:1 fail:1 skip:2 total:4
[13:40:46] ===================== [FAILED] example =====================

This example shows one minor cosmetic defect this approach has.
The test counts lines prevent us from dedenting the suite-level output.
But at the same time, any form of non-KUnit output would do the same
unless it happened to be indented as well.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

When --raw_output is set (to any value), we don't actually parse the
test results. So asking to print the test results as json doesn't make
sense.

We internally create a fake test with one passing subtest, so --json
would actually print out something misleading.

This patch:
* Rewords the flag descriptions so hopefully this is more obvious.
* Also updates --raw_output's description to note the default behavior
  is to print out only "KUnit" results (actually any KTAP results)
* also renames and refactors some related logic for clarity (e.g.
  test_result => test, it's a kunit_parser.Test object).

Notably, this patch does not make it an error to specify --json and
--raw_output together. This is an edge case, but I know of at least one
wrapper around kunit.py that always sets --json. You'd never be able to
use --raw_output with that wrapper.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Context:
1. all_tests_uml.config used to be UML specific back when users to
   manually specify CONFIG_VIRTIO_UML=y to enable CONFIG_PCI=y.
2. --alltests used allyesconfig along with a curated list of options to
   disable. It's only ever worked for brief periods of time and has
   perennially been broken due to compile issues.

Now all_tests_uml.config should work across ~all architectures.
Let's instead use this to implement --alltests.

Note: if anyone was using all_tests_uml.config, this change breaks them.
I think that's unlikely since it was added in 5.19 and was a lot to
type: --kunitconfig=tools/testing/kunit/configs/all_tests_uml.config.
We could make it a symlink to the new name, but I don't think the
caution is warranted here.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

With
$ kunit.py run --raw_output=all ...
you get the raw output from the kernel, e.g. something like
> TAP version 14
> 1..26
>     # Subtest: time_test_cases
>     1..1
>     ok 1 - time64_to_tm_test_date_range
> ok 1 - time_test_cases

But --raw_output=kunit or equivalently --raw_output, you get
> TAP version 14
> 1..26
> # Subtest: time_test_cases
> 1..1
> ok 1 - time64_to_tm_test_date_range
> ok 1 - time_test_cases

It looks less readable in my opinion, and it also isn't "raw output."

This is due to sharing code with kunit_parser.py, which wants to strip
leading whitespace since it uses anchored regexes.
We could update the kunit_parser.py code to tolerate leaading spaces,
but this patch takes the easier way out and adds a bool flag.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

It's come up a few times that it would be useful to have --kunitconfig
be repeatable [1][2].

This could be done before with a bit of shell-fu, e.g.
  $ find fs/ -name '.kunitconfig' -exec cat {} + | \
    ./tools/testing/kunit/kunit.py run --kunitconfig=/dev/stdin
or equivalently:
  $ cat fs/ext4/.kunitconfig fs/fat/.kunitconfig | \
    ./tools/testing/kunit/kunit.py run --kunitconfig=/dev/stdin

But this can be fairly clunky to use in practice.

And having explicit support in kunit.py opens the door to having more
config fragments of interest, e.g. options for PCI on UML [1], UML
coverage [2], variants of tests [3].
There's another argument to be made that users can just use multiple
--kconfig_add's, but this gets very clunky very fast (e.g. [2]).

Note: there's a big caveat here that some kconfig options might be
incompatible. We try to give a clearish error message in the simple case
where the same option appears multiple times with conflicting values,
but more subtle ones (e.g. mutually exclusive options) will be
potentially very confusing for the user. I don't know we can do better.

Note 2: if you want to combine a --kunitconfig with the default, you
either have to do to specify the current build_dir
> --kunitconfig=.kunit --kunitconfig=additional.config
or
> --kunitconfig=tools/testing/kunit/configs/default.config --kunitconifg=additional.config
each of which have their downsides (former depends on --build_dir,
doesn't work if you don't have a .kunitconfig yet), etc.

Example with conflicting values:
> $ ./tools/testing/kunit/kunit.py config --kunitconfig=lib/kunit --kunitconfig=/dev/stdin <<EOF
> CONFIG_KUNIT_TEST=n
> CONFIG_KUNIT=m
> EOF
> ...
> kunit_kernel.ConfigError: Multiple values specified for 2 options in kunitconfig:
> CONFIG_KUNIT=y
>   vs from /dev/stdin
> CONFIG_KUNIT=m
>
> CONFIG_KUNIT_TEST=y
>   vs from /dev/stdin
> # CONFIG_KUNIT_TEST is not set

[1] https://lists.freedesktop.org/archives/dri-devel/2022-June/357616.html
[2] https://lore.kernel.org/linux-kselftest/CAFd5g45f3X3xF2vz2BkTHRqOC4uW6GZxtUUMaP5mwwbK8uNVtA@mail.gmail.com/
[3] https://lore.kernel.org/linux-kselftest/CANpmjNOdSy6DuO6CYZ4UxhGxqhjzx4tn0sJMbRqo2xRFv9kX6Q@mail.gmail.com/

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>