[PATCH v6 0/3] Introduce KUNIT_EXPECT_MEMEQ and KUNIT_EXPECT_MEMNEQ macros

[Maíra Canal]

Currently, in order to compare memory blocks in KUnit, the KUNIT_EXPECT_EQ or
KUNIT_EXPECT_FALSE macros are used in conjunction with the memcmp function,
such as:
  KUNIT_EXPECT_EQ(test, memcmp(foo, bar, size), 0);

Although this usage produces correct results for the test cases, if the
expectation fails the error message is not very helpful, indicating only the
return of the memcmp function.

Therefore, create a new set of macros KUNIT_EXPECT_MEMEQ and
KUNIT_EXPECT_MEMNEQ that compare memory blocks until a determined size. In
case of expectation failure, those macros print the hex dump of the memory
blocks, making it easier to debug test failures for memory blocks.

The v6 has some changes on the first patch, due to rebase on top of Linux 6.1,
specially the renaming of KUNIT_ASSERTION macro to _KUNIT_FAILED
(97d453bc4007d4ac148c2ba89904026612b91ec9). Moreover, the DRM KUnit tests were
mainlined in 6.1.

The first patch of the series introduces the KUNIT_EXPECT_MEMEQ and
KUNIT_EXPECT_MEMNEQ. The second patch adds an example of memory block
expectations on the kunit-example-test.c. And the last patch replaces the
KUNIT_EXPECT_EQ for KUNIT_EXPECT_MEMEQ on the existing occurrences.

Best Regards,
- Maíra Canal

v1 -> v2: https://lore.kernel.org/linux-kselftest/2a0dcd75-5461-5266-2749-808f638f4c50@xxxxxxxxxx/T/#m402cc72eb01fb3b88d6706cf7d1705fdd51e5da2

- Change "determinated" to "specified" (Daniel Latypov).
- Change the macro KUNIT_EXPECT_ARREQ to KUNIT_EXPECT_MEMEQ, in order to make
it easier for users to infer the right size unit (Daniel Latypov).
- Mark the different bytes on the failure message with a <> (Daniel Latypov).
- Replace a constant number of array elements for ARRAY_SIZE() (André Almeida).
- Rename "array" and "expected" variables to "array1" and "array2" (Daniel Latypov).

v2 -> v3: https://lore.kernel.org/linux-kselftest/20220802212621.420840-1-mairacanal@xxxxxxxxxx/T/#t

- Make the bytes aligned at output.
- Add KUNIT_SUBSUBTEST_INDENT to the output for the indentation (Daniel Latypov).
- Line up the trailing \ at macros using tabs (Daniel Latypov).
- Line up the params to the functions (Daniel Latypov).
- Change "Increament" to "Augment" (Daniel Latypov).
- Use sizeof() for array sizes (Daniel Latypov).
- Add Daniel Latypov's tags.

v3 -> v4: https://lore.kernel.org/linux-kselftest/CABVgOSm_59Yr82deQm2C=18jjSv_akmn66zs4jxx3hfziXPeHg@xxxxxxxxxxxxxx/T/#t

- Fix wrapped lines by the mail client (David Gow).
- Mention on documentation that KUNIT_EXPECT_MEMEQ is not recommended for
structured data (David Gow).
- Add Muhammad Usama Anjum's tag.

v4 -> v5: https://lore.kernel.org/linux-kselftest/20220808125237.277126-1-mairacanal@xxxxxxxxxx/

- Rebase on top of drm-misc-next.
- Add David Gow's tags.

v5 -> v6: https://lore.kernel.org/linux-kselftest/20220921014515.113062-1-mairacanal@xxxxxxxxxx/

- Rebase on top of Linux 6.1.
- Change KUNIT_ASSERTION macro to _KUNIT_FAILED.

Maíra Canal (3):
  kunit: Introduce KUNIT_EXPECT_MEMEQ and KUNIT_EXPECT_MEMNEQ macros
  kunit: Add KUnit memory block assertions to the example_all_expect_macros_test
  kunit: Use KUNIT_EXPECT_MEMEQ macro

 .../gpu/drm/tests/drm_format_helper_test.c    | 12 +--
 include/kunit/assert.h                        | 33 +++++++
 include/kunit/test.h                          | 87 +++++++++++++++++++
 lib/kunit/assert.c                            | 56 ++++++++++++
 lib/kunit/kunit-example-test.c                |  7 ++
 net/core/dev_addr_lists_test.c                |  4 +-
 6 files changed, 191 insertions(+), 8 deletions(-)

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2.37.3