kunit: tool: add test for parsing attributes

Add test for parsing attributes to kunit_tool_test.py. Test checks
attributes are parsed and saved in the test logs.

This test also checks that the attributes have not interfered with the
parsing of other test information, specifically the suite header as
the test plan was being incorrectely parsed.

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

kunit: tool: Add command line interface to filter and report attributes

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>

kunit: tool: remove unused imports and variables

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>

kunit: tool: make parser preserve whitespace when printing test log

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>

kunit: tool: don't include KTAP headers and the like in the test log

We print the "test log" on failure.
This is meant to be all the kernel output that happened during the test.

But we also include the special KTAP lines in it, which are often
redundant.

E.g. we include the "not ok" line in the log, right before we print
that the test case failed...
[13:51:48] Expected 2 + 1 == 2, but
[13:51:48] 2 + 1 == 3 (0x3)
[13:51:48] not ok 1 example_simple_test
[13:51:48] [FAILED] example_simple_test

More full example after this patch:
[13:51:48] =================== example (4 subtests) ===================
[13:51:48] # example_simple_test: initializing
[13:51:48] # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29
[13:51:48] Expected 2 + 1 == 2, but
[13:51:48] 2 + 1 == 3 (0x3)
[13:51:48] [FAILED] example_simple_test

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

kunit: tool: parse KTAP compliant test output

Change the KUnit parser to be able to parse test output that complies with
the KTAP version 1 specification format found here:
https://kernel.org/doc/html/latest/dev-tools/ktap.html. Ensure the parser
is able to parse tests with the original KUnit test output format as
well.

KUnit parser now accepts any of the following test output formats:

Original KUnit test output format:

TAP version 14
1..1
# Subtest: kunit-test-suite
1..3
ok 1 - kunit_test_1
ok 2 - kunit_test_2
ok 3 - kunit_test_3
# kunit-test-suite: pass:3 fail:0 skip:0 total:3
# Totals: pass:3 fail:0 skip:0 total:3
ok 1 - kunit-test-suite

KTAP version 1 test output format:

KTAP version 1
1..1
KTAP version 1
1..3
ok 1 kunit_test_1
ok 2 kunit_test_2
ok 3 kunit_test_3
ok 1 kunit-test-suite

New KUnit test output format (changes made in the next patch of
this series):

KTAP version 1
1..1
KTAP version 1
# Subtest: kunit-test-suite
1..3
ok 1 kunit_test_1
ok 2 kunit_test_2
ok 3 kunit_test_3
# kunit-test-suite: pass:3 fail:0 skip:0 total:3
# Totals: pass:3 fail:0 skip:0 total:3
ok 1 kunit-test-suite

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

kunit: tool: tweak error message when no KTAP found

We currently tell people we "couldn't find any KTAP output" with no
indication as to what this might mean.

After this patch, we get:

$ ./tools/testing/kunit/kunit.py parse /dev/null
============================================================
[ERROR] Test: <missing>: Could not find any KTAP output. Did any KUnit tests run?
============================================================
Testing complete. Ran 0 tests: errors: 1

Note: we could try and generate a more verbose message like
> Please check .kunit/test.log to see the raw kernel output.
or the like, but we'd need to know what the build dir was to know where
test.log actually lives.

This patch tries to make a more minimal improvement.

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

kunit: tool: remove redundant file.close() call in unit test

We're using a `with` block above, so the file object is already closed.

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

kunit: tool: unit tests all check parser errors, standardize formatting a bit

Let's verify that the parser isn't reporting any errors for valid
inputs.

This change also
* does result.status checking on one line
* makes sure we consistently do it outside of the `with` block

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

kunit: tool: make TestCounts a dataclass

Since we're using Python 3.7+, we can use dataclasses to tersen the
code.

It also lets us create pre-populated TestCounts() objects and compare
them in our unit test. (Before, you could only create empty ones).

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

kunit: tool: print summary of failed tests if a few failed out of a lot

E.g. all the hw_breakpoint tests are failing right now.
So if I run `kunit.py run --altests --arch=x86_64`, then I see
> Testing complete. Ran 408 tests: passed: 392, failed: 9, skipped: 7

Seeing which 9 tests failed out of the hundreds is annoying.
If my terminal doesn't have scrollback support, I have to resort to
looking at `.kunit/test.log` for the `not ok` lines.

Teach kunit.py to print a summarized list of failures if the # of tests
reachs an arbitrary threshold (>=100 tests).

To try and keep the output from being too long/noisy, this new logic
a) just reports "parent_test failed" if every child test failed
b) won't print anything if there are >10 failures (also arbitrary).

With this patch, we get an extra line of output showing:
> Testing complete. Ran 408 tests: passed: 392, failed: 9, skipped: 7
> Failures: hw_breakpoint

This also works with parameterized tests, e.g. if I add a fake failure
> Failures: kcsan.test_atomic_builtins_missing_barrier.threads=6

Note: we didn't have enough tests for this to be a problem before.
But with commit 980ac3ad0512 ("kunit: tool: rename all_test_uml.config,
use it for --alltests"), --alltests works and thus running >100 tests
will probably become more common.

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

kunit: tool: make unit test not print parsed testdata to stdout

Currently, if you run
$ ./tools/testing/kunit/kunit_tool_test.py
you'll see a lot of output from the parser as we feed it testdata.

This makes the output hard to read and fairly confusing, esp. since our
testdata includes example failures, which get printed out in red.

Silence that output so real failures are easier to see.

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

kunit: tool: rename all_test_uml.config, use it for --alltests

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>

kunit: tool: Enable virtio/PCI by default on UML

There are several tests which depend on PCI, and hence need a bunch of
extra options to run under UML. This makes it awkward to give
configuration instructions (whether in documentation, or as part of a
.kunitconfig file), as two separate, incompatible sets of config options
are required for UML and "most other architectures".

For non-UML architectures, it's possible to add default kconfig options
via the qemu_config python files, but there's no equivalent for UML. Add
a new tools/testing/kunit/configs/arch_uml.config file containing extra
kconfig options to use on UML.

Tested-by: José Expósito <jose.exposito89@gmail.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: make --kunitconfig repeatable, blindly concat

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>

kunit: tool: refactor internal kconfig handling, allow overriding

Currently, you cannot ovewrwrite what's in your kunitconfig via
--kconfig_add.
Nor can you override something in a qemu_config via either means.

This patch makes it so we have this level of priority
* --kconfig_add
* kunitconfig file (the default or the one from --kunitconfig)
* qemu_config

The rationale for this order is that the more "dynamic" sources of
kconfig options should take priority.

--kconfig_add is obviously the most dynamic.
And for kunitconfig, users probably tweak the file manually or specify
--kunitconfig more often than they delve into qemu_config python files.

And internally, we convert the kconfigs from a python list into a set or
dict fairly often. We should just use a dict internally.
We exposed the set transform in the past since we didn't define __eq__,
so also take the chance to shore up the kunit_kconfig.Kconfig interface.

Example
=======

Let's consider the unrealistic example where someone would want to
disable CONFIG_KUNIT.
I.e. they run
$ ./tools/testing/kunit/kunit.py config --kconfig_add=CONFIG_KUNIT=n

Before
------
We'd write the following
> # CONFIG_KUNIT is not set
> CONFIG_KUNIT_ALL_TESTS=y
> CONFIG_KUNIT_TEST=y
> CONFIG_KUNIT=y
> CONFIG_KUNIT_EXAMPLE_TEST=y

And we'd error out with
> ERROR:root:Not all Kconfig options selected in kunitconfig were in the generated .config.
> This is probably due to unsatisfied dependencies.
> Missing: # CONFIG_KUNIT is not set

After
-----
We'd write the following
> # CONFIG_KUNIT is not set
> CONFIG_KUNIT_TEST=y
> CONFIG_KUNIT_ALL_TESTS=y
> CONFIG_KUNIT_EXAMPLE_TEST=y

And we'd error out with
> ERROR:root:Not all Kconfig options selected in kunitconfig were in the generated .config.
> This is probably due to unsatisfied dependencies.
> Missing: CONFIG_KUNIT_EXAMPLE_TEST=y, CONFIG_KUNIT_TEST=y, CONFIG_KUNIT_ALL_TESTS=y

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

kunit: tool: introduce --qemu_args

Example usage:
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 \
--kconfig_add=CONFIG_SMP=y --qemu_args='-smp 8'

Looking in the test.log, one can see
> smp: Bringing up secondary CPUs ...
> .... node #0, CPUs: #1 #2 #3 #4 #5 #6 #7
> smp: Brought up 1 node, 8 CPUs

This flag would allow people to make tweaks like this without having to
create custom qemu_config files.

For consistency with --kernel_args, we allow users to repeat this
argument, e.g. you can tack on a --qemu_args='-m 2048', or you could
just append it to the first string ('-smp 8 -m 2048').

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

kunit: tool: refactoring printing logic into kunit_printer.py

Context:
* kunit_kernel.py is importing kunit_parser.py just to use the
print_with_timestamp() function
* the parser is directly printing to stdout, which will become an issue
if we ever try to run multiple kernels in parallel

This patch introduces a kunit_printer.py file and migrates callers of
kunit_parser.print_with_timestamp() to call
kunit_printer.stdout.print_with_timestamp() instead.

Future changes:
If we want to support showing results for parallel runs, we could then
create new Printer's that don't directly write to stdout and refactor
the code to pass around these Printer objects.

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

kunit: tool: redo how we construct and mock LinuxSourceTree

Our main function currently has an optional `linux` argument which is
used to by our unit tests to inject a mock.
We currently have the same code copy-pasted several times to do
if not linux:
linux = MakeRealInstance(cli_args.foo, cli_args.bar, ...)

But in python, dependency injection isn't necessary or idiomatic when we
can just use mock.patch() to mock things out.

This change
1. adds a helper to create a LinuxSourceTree from the cli_args
2. drops the `linux` parameter in favor of mocking the __init__ func.

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

kunit: tool: drop unused load_config argument

It's always set to true except in one test case.
And in that test case it can safely be set to true anyways.

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

kunit: tool: misc cleanups

This primarily comes from running pylint over kunit tool code and
ignoring some warnings we don't care about.
If we ever got a fully clean setup, we could add this to run_checks.py,
but we're not there yet.

Fix things like
* Drop unused imports
* check `is None`, not `== None` (see PEP 8)
* remove redundant parens around returns
* remove redundant `else` / convert `elif` to `if` where appropriate
* rename make_arch_qemuconfig() param to base_kunitconfig (this is the
name used in the subclass, and it's a better one)
* kunit_tool_test: check the exit code for SystemExit (could be 0)

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

kunit: tool: remove dead parse_crash_in_log() logic

This logic depends on the kernel logging a message containing
'kunit test case crashed', but there is no corresponding logic to do so.

This is likely a relic of the revision process KUnit initially went
through when being upstreamed.

Delete it given
1) it's been missing for years and likely won't get implemented
2) the parser has been moving to be a more general KTAP parser,
kunit-only magic like this isn't how we'd want to implement it.

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

kunit: tool: print clearer error message when there's no TAP output

Before:
$ ./tools/testing/kunit/kunit.py parse /dev/null
...
[ERROR] Test : invalid KTAP input!

After:
$ ./tools/testing/kunit/kunit.py parse /dev/null
...
[ERROR] Test <missing>: could not find any KTAP output!

This error message gets printed out when extract_tap_output() yielded no
lines. So while it could be because of malformed KTAP output from KUnit,
it could also be due to not having any KTAP output at all.

Try and make the error message here more clear.

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

kunit: tool: more descriptive metavars/--help output

Before, our help output contained lines like
--kconfig_add KCONFIG_ADD
--qemu_config qemu_config
--jobs jobs

They're not very helpful.

The former kind come from the automatic 'metavar' we get from argparse,
the uppercase version of the flag name.
The latter are where we manually specified metavar as the flag name.

After:
--build_dir DIR
--make_options X=Y
--kunitconfig PATH
--kconfig_add CONFIG_X=Y
--arch ARCH
--cross_compile PREFIX
--qemu_config FILE
--jobs N
--timeout SECONDS
--raw_output [{all,kunit}]
--json [FILE]

This patch tries to make the code more clear by specifying the _type_ of
input we expect, e.g. --build_dir is a DIR, --qemu_config is a FILE.
I also switched it to uppercase since it looked more clearly like
placeholder text that way.

This patch also changes --raw_output to specify `choices` to make it
more clear what the options are, and this way argparse can validate it
for us, as shown by the added test case.

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

kunit: tool: refactor how we plumb metadata into JSON

When using --json, kunit.py run/exec/parse will produce results in
KernelCI json format.
As part of that, we include the build_dir that was used, and we
(incorrectly) hardcode in the arch, etc.

We'll want a way to plumb more values (as well as the correct `arch`),
so this patch groups those fields into kunit_json.Metadata type.
This patch should have no user visible changes.

And since we only used build_dir in KunitParseRequest for json, we can
now move it out of that struct and add it into KunitExecRequest, which
needs it and used to get it via inheritance.

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

kunit: tool: simplify code since build_dir can't be None

--build_dir is set to a default of '.kunit' since commit ddbd60c779b4
("kunit: use --build_dir=.kunit as default"), but even before then it
was explicitly set to ''.

So outside of one unit test, there was no way for the build_dir to be
ever be None, and we can simplify code by fixing the unit test and
enforcing that via updated type annotations.

E.g. this lets us drop `get_file_path()` since it's now exactly
equivalent to os.path.join().

Note: there's some `if build_dir` checks that also fail if build_dir is
explicitly set to '' that just guard against passing "O=" to make.
But running `make O=` works just fine, so drop these checks.

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

kunit: tool: make --json handling a bit clearer

Currently kunit_json.get_json_result() will output the JSON-ified test
output to json_path, but iff it's not "stdout".

Instead, move the responsibility entirely over to the one caller.

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

kunit: tool: Default --jobs to number of CPUs

The --jobs parameter for kunit_tool currently defaults to 8 CPUs,
regardless of the number available. For systems with significantly more
(or less), this is not as efficient. Instead, default --jobs to the
number of CPUs available to the process: while there are as many
superstitions as to exactly what the ideal jobs:CPU ratio is, this seems
sufficiently sensible to me.

A new helper function to get the default number of jobs is added:
get_default_jobs() -- this is used in kunit_tool_test instead of a
hardcoded value, or an explicit call to len(os.sched_getaffinity()), so
should be more flexible if this needs to change in the future.

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

kunit: tool: make `build` subcommand also reconfigure if needed

If I created a kunitconfig file that was incomplete, then
$ ./tools/testing/kunit/kunit.py build --kunitconfig=my_kunitconfig
would silently drop all the options with unmet dependencies!

This is because it doesn't do the config check that `kunit.py config`
does.

So if I want to safely build a kernel for testing, I have to do
$ ./tools/testing/kunit/kunit.py config <flags>
$ ./tools/testing/kunit/kunit.py build <flags, again>

It seems unlikely that any user of kunit.py would want the current
`build` semantics.
So make it effectively do `kunit.py config` + `kunit.py build`.

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

kunit: tool: delete kunit_parser.TestResult type

The `log` field is unused, and the `status` field is accessible via
`test.status`.

So it's simpler to just return the main `Test` object directly.

And since we're no longer returning a namedtuple, which has no type
annotations, this hopefully means typecheckers are better equipped to
find any errors.

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

kunit: tool: use dataclass instead of collections.namedtuple

namedtuple is a terse way of defining a collection of fields.
However, it does not allow us to annotate the type of these fields.
It also doesn't let us have any sort of inheritance between types.

Since commit df4b0807ca1a ("kunit: tool: Assert the version
requirement"), kunit.py has asserted that it's running on python >=3.7.

So in that case use a 3.7 feature, dataclasses, to replace these.

Changes in detail:
* Make KunitExecRequest contain all the fields needed for exec_tests
* Use inheritance to dedupe fields
* also allows us to e.g. pass a KUnitRequest in as a KUnitParseRequest
* this has changed around the order of some fields
* Use named arguments when constructing all request objects in kunit.py
* This is to prevent accidentally mixing up fields, etc.

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

kunit: tool: reconfigure when the used kunitconfig changes

Problem: currently, if you remove something from your kunitconfig,
kunit.py will not regenerate the .config file.
The same thing happens if you did --kunitconfig_add=CONFIG_KASAN=y [1]
and then ran again without it. Your new run will still have KASAN.

The reason is that kunit.py won't regenerate the .config file if it's a
superset of the kunitconfig. This speeds it up a bit for iterating.

This patch adds an additional check that forces kunit.py to regenerate
the .config file if the current kunitconfig doesn't match the previous
one.

What this means:
* deleting entries from .kunitconfig works as one would expect
* dropping a --kunitconfig_add also triggers a rebuild
* you can still edit .config directly to turn on new options

We implement this by creating a `last_used_kunitconfig` file in the
build directory (so .kunit, by default) after we generate the .config.
When comparing the kconfigs, we compare python sets, so duplicates and
permutations don't trip us up.

The majority of this patch is adding unit tests for the existing logic
and for the new case where `last_used_kunitconfig` differs.

[1] https://lore.kernel.org/linux-kselftest/20211106013058.2621799-2-dlatypov@google.com/

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

kunit: tool: add --kconfig_add to allow easily tweaking kunitconfigs

E.g. run tests but with KASAN
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kconfig_add=CONFIG_KASAN=y

This also works with --kunitconfig
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kunitconfig=fs/ext4 --kconfig_add=CONFIG_KASAN=y

This flag is inspired by TuxMake's --kconfig-add, see
https://gitlab.com/Linaro/tuxmake#examples.

Our version just uses "_" as the delimiter for consistency with
pre-existing flags like --build_dir, --make_options, --kernel_args, etc.

Note: this does make it easier to run into a pre-existing edge case:
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kconfig_add=CONFIG_KASAN=y
$ ./tools/testing/kunit/kunit.py run --arch=x86_64
This second invocation ^ still has KASAN enabled!

kunit.py won't call olddefconfig if our current .config is already a
superset of the provided kunitconfig.

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

kunit: tool: move Kconfig read_from_file/parse_from_string to package-level

read_from_file() clears its `self` Kconfig object and parses a config
file.

It is a way to construct Kconfig objects more so than an operation on
Kconfig objects. This is reflected in the fact its only ever used as:
kconfig = kunit_config.Kconfig()
kconfig.read_from_file(path)

So clean this up and simplify callers by replacing it with
kconfig = kunit_config.parse_file(path)

Do the same thing for the related parse_from_string() function as well.

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

kunit: tool: print parsed test results fully incrementally

With the parser rework [1] and run_kernel() rework [2], this allows the
parser to print out test results incrementally.

Currently, that's held up by the fact that the LineStream eagerly
pre-fetches the next line when you call pop().
This blocks parse_test_result() from returning until the line *after*
the "ok 1 - test name" line is also printed.

One can see this with the following example:
$ (echo -e 'TAP version 14\n1..3\nok 1 - fake test'; sleep 2; echo -e 'ok 2 - fake test 2'; sleep 3; echo -e 'ok 3 - fake test 3') | ./tools/testing/kunit/kunit.py parse

Before this patch [1]: there's a pause before 'fake test' is printed.
After this patch: 'fake test' is printed out immediately.

This patch also adds
* a unit test to verify LineStream's behavior directly
* a test case to ensure that it's lazily calling the generator
* an explicit exception for when users go beyond EOF

[1] https://lore.kernel.org/linux-kselftest/20211006170049.106852-1-dlatypov@google.com/
[2] https://lore.kernel.org/linux-kselftest/20211005011340.2826268-1-dlatypov@google.com/

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

kunit: tool: Report an error if any test has no subtests

It's possible for a test to have a subtest header, but zero valid
subtests. We used to error on this if the test plan had no subtests
listed, but it's possible to have subtests without a test plan (indeed,
this is how parameterised tests work).

Tests with 0 subtests now have the result NO_TESTS, and will report an
error (which does not halt test execution, but is printed in a scary red
colour and is noted in the results summary).

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

kunit: tool: Do not error on tests without test plans

The (K)TAP spec encourages test output to begin with a 'test plan': a
count of the number of tests being run of the form:
1..n

However, some test suites might not know the number of subtests in
advance (for example, KUnit's parameterised tests use a generator
function). In this case, it's not possible to print the test plan in
advance.

kunit_tool already parses test output which doesn't contain a plan, but
reports an error. Since we want to use nested subtests with KUnit
paramterised tests, remove this error.

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

kunit: tool: fix --json output for skipped tests

Currently, KUnit will report SKIPPED tests as having failed if one uses
--json.

Add the missing if statement to set the appropriate status ("SKIP").
See https://api.kernelci.org/schema-test-case.html:
"status": {
"type": "string",
"description": "The status of the execution of this test case",
"enum": ["PASS", "FAIL", "SKIP", "ERROR"],
"default": "PASS"
},
with this, we now can properly produce all four of the statuses.

Fixes: 5acaf6031f53 ("kunit: tool: Support skipped tests in kunit_tool")
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: improve compatibility of kunit_parser with KTAP specification

Update to kunit_parser to improve compatibility with KTAP
specification including arbitrarily nested tests. Patch accomplishes
three major changes:

- Use a general Test object to represent all tests rather than TestCase
and TestSuite objects. This allows for easier implementation of arbitrary
levels of nested tests and promotes the idea that both test suites and test
cases are tests.

- Print errors incrementally rather than all at once after the
parsing finishes to maximize information given to the user in the
case of the parser given invalid input and to increase the helpfulness
of the timestamps given during printing. Note that kunit.py parse does
not print incrementally yet. However, this fix brings us closer to
this feature.

- Increase compatibility for different formats of input. Arbitrary levels
of nested tests supported. Also, test cases and test suites are now
supported to be present on the same level of testing.

This patch now implements the draft KTAP specification here:
https://lore.kernel.org/linux-kselftest/CA+GJov6tdjvY9x12JsJT14qn6c7NViJxqaJk+r-K1YJzPggFDQ@mail.gmail.com/
We'll update the parser as the spec evolves.

This patch adjusts the kunit_tool_test.py file to check for
the correct outputs from the new parser and adds a new test to check
the parsing for a KTAP result log with correct format for multiple nested
subtests (test_is_test_passed-all_passed_nested.log).

This patch also alters the kunit_json.py file to allow for arbitrarily
nested tests.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: yield output from run_kernel in real time

Currently, `run_kernel()` dumps all the kernel output to a file
(.kunit/test.log) and then opens the file and yields it to callers.
This made it easier to respect the requested timeout, if any.

But it means that we can't yield the results in real time, either to the
parser or to stdout (if --raw_output is set).

This change spins up a background thread to enforce the timeout, which
allows us to yield the kernel output in real time, while also copying it
to the .kunit/test.log file.
It's also careful to ensure that the .kunit/test.log file is complete,
even in the kunit_parser throws an exception/otherwise doesn't consume
every line, see the new `finally` block and unit test.

For example:

$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --raw_output
<configure + build steps>
...
<can now see output from QEMU in real time>

This does not currently have a visible effect when --raw_output is not
passed, as kunit_parser.py currently only outputs everything at the end.
But that could change, and this patch is a necessary step towards
showing parsed test results in real time.

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

kunit: tool: support running each suite/test separately

The new --run_isolated flag makes the tool boot the kernel once per
suite or test, preventing leftover state from one suite to impact the
other. This can be useful as a starting point to debugging test
hermeticity issues.

Note: it takes a lot longer, so people should not use it normally.

Consider the following very simplified example:

bool disable_something_for_test = false;
void function_being_tested() {
...
if (disable_something_for_test) return;
...
}

static void test_before(struct kunit *test)
{
disable_something_for_test = true;
function_being_tested();
/* oops, we forgot to reset it back to false */
}

static void test_after(struct kunit *test)
{
/* oops, now "fixing" test_before can cause test_after to fail! */
function_being_tested();
}

Presented like this, the issues are obvious, but it gets a lot more
complicated to track down as the amount of test setup and helper
functions increases.

Another use case is memory corruption. It might not be surfaced as a
failure/crash in the test case or suite that caused it. I've noticed in
kunit's own unit tests, the 3rd suite after might be the one to finally
crash after an out-of-bounds write, for example.

Example usage:

Per suite:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit --run_isolated=suite
...
Starting KUnit Kernel (1/7)...
============================================================
======== [PASSED] kunit_executor_test ========
....
Testing complete. 5 tests run. 0 failed. 0 crashed. 0 skipped.
Starting KUnit Kernel (2/7)...
============================================================
======== [PASSED] kunit-try-catch-test ========
...

Per test:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit --run_isolated=test
Starting KUnit Kernel (1/23)...
============================================================
======== [PASSED] kunit_executor_test ========
[PASSED] parse_filter_test
============================================================
Testing complete. 1 tests run. 0 failed. 0 crashed. 0 skipped.
Starting KUnit Kernel (2/23)...
============================================================
======== [PASSED] kunit_executor_test ========
[PASSED] filter_subsuite_test
...

It works with filters as well:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit --run_isolated=suite example
...
Starting KUnit Kernel (1/1)...
============================================================
======== [PASSED] example ========
...

It also handles test filters, '*.*skip*' runs these 3 tests:
kunit_status.kunit_status_mark_skipped_test
example.example_skip_test
example.example_mark_skipped_test

Fixed up merge conflict between:
d8c23ead708b ("kunit: tool: better handling of quasi-bool args (--json, --raw_output)") and
6710951ee039 ("kunit: tool: support running each suite/test separately")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Shuah Khan <skhan@linuxfoundation.org>

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

kunit: tool: show list of valid --arch options when invalid

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>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: misc fixes (unused vars, imports, leaked files)

Drop some variables in unit tests that were unused and/or add assertions
based on them.

For ExitStack, it was imported, but the `es` variable wasn't used so it
didn't do anything, and we were leaking the file objects.
Refactor it to just use nested `with` statements to properly close them.

And drop the direct use of .close() on file objects in the kunit tool
unit test, as these can be leaked if test assertions fail.

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

kunit: tool: better handling of quasi-bool args (--json, --raw_output)

Problem:

What does this do?
$ kunit.py run --json
Well, it runs all the tests and prints test results out as JSON.

And next is
$ kunit.py run my-test-suite --json
This runs just `my-test-suite` and prints results out as JSON.

But what about?
$ kunit.py run --json my-test-suite
This runs all the tests and stores the json results in a "my-test-suite"
file.

Why:
--json, and now --raw_output are actually string flags. They just have a
default value. --json in particular takes the name of an output file.

It was intended that you'd do
$ kunit.py run --json=my_output_file my-test-suite
if you ever wanted to specify the value.

Workaround:
It doesn't seem like there's a way to make
https://docs.python.org/3/library/argparse.html only accept arg values
after a '='.

I believe that `--json` should "just work" regardless of where it is.
So this patch automatically rewrites a bare `--json` to `--json=stdout`.

That makes the examples above work the same way.
Add a regression test that can catch this for --raw_output.

Fixes: 6a499c9c42d0 ("kunit: tool: make --raw_output support only showing kunit output")
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: make --raw_output support only showing kunit output

--raw_output is nice, but it would be nicer if could show only output
after KUnit tests have started.

So change the flag to allow specifying a string ('kunit').
Make it so `--raw_output` alone will default to `--raw_output=all` and
have the same original behavior.

Drop the small kunit_parser.raw_output() function since it feels wrong
to put it in "kunit_parser.py" when the point of it is to not parse
anything.

E.g.

$ ./tools/testing/kunit/kunit.py run --raw_output=kunit
...
[15:24:07] Starting KUnit Kernel ...
TAP version 14
1..1
# Subtest: example
1..3
# example_simple_test: initializing
ok 1 - example_simple_test
# example_skip_test: initializing
# example_skip_test: You should not see a line below.
ok 2 - example_skip_test # SKIP this test should be skipped
# example_mark_skipped_test: initializing
# example_mark_skipped_test: You should see a line below.
# example_mark_skipped_test: You should see this line.
ok 3 - example_mark_skipped_test # SKIP this test should be skipped
ok 1 - example
[15:24:10] Elapsed time: 6.487s total, 0.001s configuring, 3.510s building, 0.000s running

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

kunit: tool: add --kernel_args to allow setting module params

kunit.py currently does not make it possible for users to specify module
parameters (/kernel arguments more generally) unless one directly tweaks
the kunit.py code itself.

This hasn't mattered much so far, but this would make it easier to port
existing tests that expose module parameters over to KUnit and/or let
current KUnit tests take advantage of them.

Tested using an kunit internal parameter:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit \
--kernel_args=kunit.filter_glob=kunit_status
...
Testing complete. 2 tests run. 0 failed. 0 crashed. 0 skipped.

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

kunit: tool: Fix error messages for cases of no tests and wrong TAP header

This patch addresses misleading error messages reported by kunit_tool in
two cases. First, in the case of TAP output having an incorrect header
format or missing a header, the parser used to output an error message of
'no tests run!'. Now the parser outputs an error message of 'could not
parse test results!'.

As an example:

Before:
$ ./tools/testing/kunit/kunit.py parse /dev/null
[ERROR] no tests run!
...

After:
$ ./tools/testing/kunit/kunit.py parse /dev/null
[ERROR] could not parse test results!
...

Second, in the case of TAP output with the correct header but no
tests, the parser used to output an error message of 'could not parse
test results!'. Now the parser outputs an error message of 'no tests
run!'.

As an example:

Before:
$ echo -e 'TAP version 14\n1..0' | ./tools/testing/kunit/kunit.py parse
[ERROR] could not parse test results!

After:
$ echo -e 'TAP version 14\n1..0' | ./tools/testing/kunit/kunit.py parse
[ERROR] no tests run!

Additionally, this patch also corrects the tests in kunit_tool_test.py
and adds a test to check the error in the case of TAP output with the
correct header but no tests.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: Support skipped tests in kunit_tool

Add support for the SKIP directive to kunit_tool's TAP parser.

Skipped tests now show up as such in the printed summary. The number of
skipped tests is counted, and if all tests in a suite are skipped, the
suite is also marked as skipped. Otherwise, skipped tests do affect the
suite result.

Example output:
[00:22:34] ======== [SKIPPED] example_skip ========
[00:22:34] [SKIPPED] example_skip_test # SKIP this test should be skipped
[00:22:34] [SKIPPED] example_mark_skipped_test # SKIP this test should be skipped
[00:22:34] ============================================================
[00:22:34] Testing complete. 2 tests run. 0 failed. 0 crashed. 2 skipped.

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

kunit: tool: internal refactor of parser input handling

Note: this does not change the parser behavior at all (except for making
one error message more useful). This is just an internal refactor.

The TAP output parser currently operates over a List[str].
This works, but we only ever need to be able to "peek" at the current
line and the ability to "pop" it off.

Also, using a List means we need to wait for all the output before we
can start parsing. While this is not an issue for most tests which are
really lightweight, we do have some longer (~5 minutes) tests.

This patch introduces an LineStream wrapper class that
* Exposes a peek()/pop() interface instead of manipulating an array
* this allows us to more easily add debugging code [1]
* Can consume an input from a generator
* we can now parse results as tests are running (the parser code
currently doesn't print until the end, so no impact yet).
* Tracks the current line number to print better error messages
* Would allow us to add additional features more easily, e.g. storing
N previous lines so we can print out invalid lines in context, etc.

[1] The parsing logic is currently quite fragile.
E.g. it'll often say the kernel "CRASHED" if there's something slightly
wrong with the output format. When debugging a test that had some memory
corruption issues, it resulted in very misleading errors from the parser.

Now we could easily add this to trace all the lines consumed and why
+import inspect
...
def pop(self) -> str:
n = self._next
+ print(f'popping {n[0]}: {n[1].ljust(40, " ")}| caller={inspect.stack()[1].function}')

Example output:
popping 77: TAP version 14 | caller=parse_tap_header
popping 78: 1..1 | caller=parse_test_plan
popping 79: # Subtest: kunit_executor_test | caller=parse_subtest_header
popping 80: 1..2 | caller=parse_subtest_plan
popping 81: ok 1 - parse_filter_test | caller=parse_ok_not_ok_test_case
popping 82: ok 2 - filter_subsuite_test | caller=parse_ok_not_ok_test_case
popping 83: ok 1 - kunit_executor_test | caller=parse_ok_not_ok_test_suite

If we introduce an invalid line, we can see the parser go down the wrong path:
popping 77: TAP version 14 | caller=parse_tap_header
popping 78: 1..1 | caller=parse_test_plan
popping 79: # Subtest: kunit_executor_test | caller=parse_subtest_header
popping 80: 1..2 | caller=parse_subtest_plan
popping 81: 1..2 # this is invalid! | caller=parse_ok_not_ok_test_case
popping 82: ok 1 - parse_filter_test | caller=parse_ok_not_ok_test_case
popping 83: ok 2 - filter_subsuite_test | caller=parse_ok_not_ok_test_case
popping 84: ok 1 - kunit_executor_test | caller=parse_ok_not_ok_test_case
[ERROR] ran out of lines before end token

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

kunit: tool: add support for QEMU

Add basic support to run QEMU via kunit_tool. Add support for i386,
x86_64, arm, arm64, and a bunch more.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: make --kunitconfig accept dirs, add lib/kunit fragment

TL;DR
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit

Per suggestion from Ted [1], we can reduce the amount of typing by
assuming a convention that these files are named '.kunitconfig'.

In the case of [1], we now have
$ ./tools/testing/kunit/kunit.py run --kunitconfig=fs/ext4

Also add in such a fragment for kunit itself so we can give that as an
example more close to home (and thus less likely to be accidentally
broken).

[1] https://lore.kernel.org/linux-ext4/YCNF4yP1dB97zzwD@mit.edu/

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

kunit: tool: add support for filtering suites by glob

This allows running different subsets of tests, e.g.

$ ./tools/testing/kunit/kunit.py build
$ ./tools/testing/kunit/kunit.py exec 'list*'
$ ./tools/testing/kunit/kunit.py exec 'kunit*'

This passes the "kunit_filter.glob" commandline option to the UML
kernel, which currently only supports filtering by suite name.

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

kunit: make kunit_tool accept optional path to .kunitconfig fragment

Currently running tests via KUnit tool means tweaking a .kunitconfig
file, which you'd keep around locally and never commit.
This changes makes it so users can pass in a path to a kunitconfig.

One of the imagined use cases is having kunitconfig fragments in-tree
to formalize interesting sets of tests for features/subsystems, e.g.
$ ./tools/testing/kunit/kunit.py run --kunticonfig=fs/ext4/kunitconfig

For now, this hypothetical fs/ext4/kunitconfig would contain
CONFIG_KUNIT=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_KUNIT_TESTS=y

At the moment, it's not hard to manually whip up this file, but as more
and more tests get added, this will get tedious.

It also opens the door to documenting how to run all the tests relevant
to a specific subsystem or feature as a simple one-liner.

This can be seen as an analogue to tools/testing/selftests/*/config
But in the case of KUnit, the tests live in the same directory as the
code-under-test, so it feels more natural to allow the kunitconfig
fragments to live anywhere. (Though, people could create a separate
directory if wanted; this patch imposes no restrictions on the path).

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

minor: kunit: tool: fix unit test so it can run from non-root dir

Also take this time to rename get_absolute_path() to test_data_path().

1. the name is currently a lie. It gives relative paths, e.g. if I run
from the same dir as the test file, it gives './test_data/<file>'

See https://docs.python.org/3/reference/import.html#__file__, which
doesn't stipulate that implementations provide absolute paths.

2. it's only used for generating paths to tools/testing/kunit/test_data/
So we can tersen things by making it less general.

Cache the absolute path to the test data files per suggestion from [1].
Using relative paths, the tests break because of this code in kunit.py
if get_kernel_root_path():
        os.chdir(get_kernel_root_path())

[1] https://lore.kernel.org/linux-kselftest/CABVgOSnH0gz7z5JhRCGyG1wg0zDDBTLoSUCoB-gWMeXLgVTo2w@mail.gmail.com/

Fixes: 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside kernel tree")
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: use `with open()` in unit test

The use of manual open() and .close() calls seems to be an attempt to
keep the contents in scope.
But Python doesn't restrict variables like that, so we can introduce new
variables inside of a `with` and use them outside.

Do so to make the code more Pythonic.

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

kunit: tool: stop using bare asserts in unit test

Use self.assertEqual/assertNotEqual() instead.
Besides being more appropriate in a unit test, it'll also give a better
error message by show the unexpected values.

Also
* Delete redundant check of exception types. self.assertRaises does this.
* s/kall/call. There's no reason to name it this way.
* This is probably a misunderstanding from the docs which uses it
since `mock.call` is in scope as `call`.

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

kunit: tool: fix unit test cleanup handling

* Stop leaking file objects.
* Use self.addCleanup() to ensure we call cleanup functions even if
setUp() fails.
* use mock.patch.stopall instead of more error-prone manual approach

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

tweewide: Fix most Shebang lines

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kunit: tool: fix extra trailing \n in raw + parsed test output

For simplcity, strip all trailing whitespace from parsed output.
I imagine no one is printing out meaningful trailing whitespace via
KUNIT_FAIL() or similar, and that if they are, they really shouldn't.

`isolate_kunit_output()` yielded liens with trailing \n, which results
in artifacty output like this:

$ ./tools/testing/kunit/kunit.py run
[16:16:46] [FAILED] example_simple_test
[16:16:46] # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29

[16:16:46] Expected 1 + 1 == 3, but

[16:16:46] 1 + 1 == 2

[16:16:46] 3 == 3

[16:16:46] not ok 1 - example_simple_test

[16:16:46]

After this change:
[16:16:46] # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29
[16:16:46] Expected 1 + 1 == 3, but
[16:16:46] 1 + 1 == 2
[16:16:46] 3 == 3
[16:16:46] not ok 1 - example_simple_test
[16:16:46]

We should *not* be expecting lines to end with \n in kunit_tool_test.py
for this reason.

Do the same for `raw_output()` as well which suffers from the same
issue.

This is a followup to [1], but rebased onto kunit-fixes to pick up the
other raw_output() fix and fixes for kunit_tool_test.py.

[1] https://lore.kernel.org/linux-kselftest/20201020233219.4146059-1-dlatypov@google.com/

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

kunit: tools: fix kunit_tool tests for parsing test plans

Some tests logs for kunit_tool tests are missing their test plans
causing their tests to fail; fix this by adding the test plans.

Fixes: 45dcbb6f5ef7 ("kunit: test: add test plan to KUnit TAP format")
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: allow generating test results in JSON

Add a --json flag, which when specified generates JSON formatted test
results conforming to the KernelCI API test_group spec[1]. The user can
use the new flag to specify a filename to print the json formatted
results to.

Link[1]: https://api.kernelci.org/schema-test-group.html#post
Signed-off-by: Heidi Fahim <heidifahim@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix improper treatment of file location

Commit 01397e822af4 ("kunit: Fix TabError, remove defconfig code and
handle when there is no kunitconfig") and commit 45ba7a893ad8 ("kunit:
kunit_tool: Separate out config/build/exec/parse") introduced two
closely related issues which built off of each other: they excessively
created the build directory when not present and modified a constant
(constants in Python only exist by convention).

Together these issues broken a number of unit tests for KUnit tool, so
fix them.

Fixed up commit log to fic checkpatch commit description style error.
Shuah Khan <skhan@linuxfoundation.org>

Fixes: 01397e822af4 ("kunit: Fix TabError, remove defconfig code and handle when there is no kunitconfig")
Fixes: 45ba7a893ad8 ("kunit: kunit_tool: Separate out config/build/exec/parse")
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix broken default args in unit tests

Commit ddbd60c779b4 ("kunit: use --build_dir=.kunit as default") changed
the default build directory for KUnit tests, but failed to update
associated unit tests for kunit_tool, so update them.

Fixes: ddbd60c779b4 ("kunit: use --build_dir=.kunit as default")
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: show error if kunit results are not present

Currently, if the kernel is configured incorrectly or if it crashes before any
kunit tests are run, kunit finishes without error, reporting
that 0 test cases were run.

To fix this, an error is shown when the tap header is not found, which
indicates that kunit was not able to run at all.

Signed-off-by: Uriel Guajardo <urielguajardo@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: kunit_tool: Separate out config/build/exec/parse

Add new subcommands to kunit.py to allow stages of the existing 'run'
subcommand to be run independently:
- 'config': Verifies that .config is a subset of .kunitconfig
- 'build': Compiles a UML kernel for KUnit
- 'exec': Runs the kernel, and outputs the test results.
- 'parse': Parses test results from a file or stdin

The 'run' command continues to behave as before.

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: kunit_tool: Allow .kunitconfig to disable config items

Rework kunit_tool in order to allow .kunitconfig files to better enforce
that disabled items in .kunitconfig are disabled in the generated
.config.

Previously, kunit_tool simply enforced that any line present in
.kunitconfig was also present in .config, but this could cause problems
if a config option was disabled in .kunitconfig, but not listed in .config
due to (for example) having disabled dependencies.

To fix this, re-work the parser to track config names and values, and
require values to match unless they are explicitly disabled with the
"CONFIG_x is not set" comment (or by setting its value to 'n'). Those
"disabled" values will pass validation if omitted from the .config, but
not if they have a different value.

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Run all KUnit tests through allyesconfig

Implemented the functionality to run all KUnit tests through kunit_tool
by specifying an --alltests flag, which builds UML with allyesconfig
enabled, and consequently runs every KUnit test. A new function was
added to kunit_kernel: make_allyesconfig.
Firstly, if --alltests is specified, kunit.py triggers build_um_kernel
which call make_allyesconfig. This function calls the make command,
disables the broken configs that would otherwise prevent UML from
building, then starts the kernel with all possible configurations
enabled. All stdout and stderr is sent to test.log and read from there
then fed through kunit_parser to parse the tests to the user. Also added
a signal_handler in case kunit is interrupted while running.
Tested: Run under different conditions such as testing with
--raw_output, testing program interrupt then immediately running kunit
again without --alltests and making sure to clean the console.

Signed-off-by: Heidi Fahim <heidifahim@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: kunit_parser: make parser more robust

Previously, kunit_parser did not properly handle kunit TAP output that
- had any prefixes (generated from different configs e.g.
CONFIG_PRINTK_TIME)
- had unrelated kernel output mixed in the middle of
it, which has shown up when testing with allyesconfig
To remove prefixes, the parser looks for the first line that includes
TAP output, "TAP version 14". It then determines the length of the
string before this sequence, and strips that number of characters off
the beginning of the following lines until the last KUnit output line is
reached.
These fixes have been tested with additional tests in the
KUnitParseTest and their associated logs have also been added.

Signed-off-by: Heidi Fahim <heidifahim@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit/kunit_tool_test: Test '--build_dir' option run

This commit adds kunit tool test for the '--build_dir' option.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Place 'test.log' under the 'build_dir'

'kunit' writes the 'test.log' under the kernel source directory even
though a 'build_dir' option is given. As users who use the option might
expect the outputs to be placed under the specified directory, this
commit modifies the logic to write the log file under the 'build_dir'.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: testing kunit: Bug fix in test_run_timeout function

Assert in test_run_timeout was not updated with the build_dir argument
and caused the following error:
AssertionError: Expected call: run_kernel(timeout=3453)
Actual call: run_kernel(build_dir=None, timeout=3453)

Needed to update kunit_tool_test to reflect this fix
https://lkml.org/lkml/2019/9/6/351

Signed-off-by: Heidi Fahim <heidifahim@google.com>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: add Python wrappers for running KUnit tests

The ultimate goal is to create minimal isolated test binaries; in the
meantime we are using UML to provide the infrastructure to run tests, so
define an abstract way to configure and run tests that allow us to
change the context in which tests are built without affecting the user.
This also makes pretty and dynamic error reporting, and a lot of other
nice features easier.

kunit_config.py:
- parse .config and Kconfig files.

kunit_kernel.py: provides helper functions to:
- configure the kernel using kunitconfig.
- build the kernel with the appropriate configuration.
- provide function to invoke the kernel and stream the output back.

kunit_parser.py: parses raw logs returned out by kunit_kernel and
displays them in a user friendly way.

test_data/*: samples of test data for testing kunit.py, kunit_config.py,
etc.

Signed-off-by: Felix Guo <felixguoxiuping@gmail.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>