If the compiler doesn't optimize them away, each kunit assertion (use of KUNIT_EXPECT_EQ, etc.) can use 88 bytes of stack space in the worst and most common case. This has led to compiler warnings for certain configs + arches [1].
This series builds upon [2] which cut down kunit_assert from 48 => 24 bytes, but only reduced kunit_binary_assert (the most common one) from 88 => 48.
Now we have kunit_assert = 8 and kunit_binary_assert = 32. The cost is we need to pass around another parameter to some functions (struct va_format *), and we introduce a new type (sturct kunit_binary_assert_text) for holding the textual representation of the KUNIT_EXPECT_EQ arguments.
Note: it's possible to get kunit_assert = 0 and kunit_binary_assert = 24 by removing the `format` function pointer field from kunit_assert. I think it's an improvement, but others might think that readability suffers from doing so, so I'm leaving that off from this series.
Meta: this series applies on top of 5.17-rc1 + [2] and [3]. That should be available at in Shuah's kunit branch [4], but my version of git is constantly segfaulting, so I can't try and rebase to verify.
[1] https://groups.google.com/g/kunit-dev/c/i3fZXgvBrfA/m/VULQg1z6BAAJ [2] https://lore.kernel.org/linux-kselftest/20220113165931.451305-6-dlatypov@goo... [3] https://lore.kernel.org/linux-kselftest/20220118223506.1701553-1-dlatypov@go... [4] https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/?h...
Daniel Latypov (3): kunit: remove va_format from kunit_assert kunit: consolidate KUNIT_INIT_BINARY_ASSERT_STRUCT macros kunit: factor out str constants from binary assertion structs
include/kunit/assert.h | 152 ++++++++++++----------------------------- include/kunit/test.h | 32 +++++---- lib/kunit/assert.c | 65 ++++++++++-------- lib/kunit/test.c | 12 ++-- 4 files changed, 104 insertions(+), 157 deletions(-)