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Date:   Thu, 13 May 2021 12:31:55 -0700
Message-Id: <20210513193204.816681-1-davidgow@google.com>
Mime-Version: 1.0
Subject: [PATCH v2 01/10] kunit: Do not typecheck binary assertions
From:   David Gow <davidgow@google.com>
To:     Brendan Higgins <brendanhiggins@google.com>,
        Daniel Latypov <dlatypov@google.com>,
        Shuah Khan <skhan@linuxfoundation.org>
Cc:     David Gow <davidgow@google.com>, kunit-dev@googlegroups.com,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

The use of typecheck() in KUNIT_EXPECT_EQ() and friends is causing more
problems than I think it's worth. Things like enums need to have their
values explicitly cast, and literals all need to be very precisely
typed, else a large warning will be printed.

While typechecking does have its uses, the additional overhead of having
lots of needless casts -- combined with the awkward error messages which
don't mention which types are involved -- makes tests less readable and
more difficult to write.

By removing the typecheck() call, the two arguments still need to be of
compatible types, but don't need to be of exactly the same time, which
seems a less confusing and more useful compromise.

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

Changes since v1:
https://lore.kernel.org/linux-kselftest/20210507050908.1008686-1-davidgow@google.com/
- Tidy up the patch description to note that a warning was being
  produced, not an error.
- Add additional patches to remove many of the now unnecessary casts.

 include/kunit/test.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 49601c4b98b8..4c56ffcb7403 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -775,7 +775,6 @@ void kunit_do_assertion(struct kunit *test,
 do {									       \
 	typeof(left) __left = (left);					       \
 	typeof(right) __right = (right);				       \
-	((void)__typecheck(__left, __right));				       \
 									       \
 	KUNIT_ASSERTION(test,						       \
 			__left op __right,				       \
-- 
2.31.1.751.gd2f1c929bd-goog