On Wed, Jan 12, 2022 at 3:42 AM Daniel Latypov <dlatypov@xxxxxxxxxx> wrote:
>
> Currently the code always calls kunit_do_assertion() even though it does
> nothing when `pass` is true.
>
> This change moves the `if(!(pass))` check into the macro instead
> and renames the function to kunit_do_failed_assertion().
> I feel this a bit easier to read and understand.
>
> This has the potential upside of avoiding a function call that does
> nothing most of the time (assuming your tests are passing) but comes
> with the downside of generating a bit more code and branches. We try to
> mitigate the branches by tagging them with `unlikely()`.
>
> This also means we don't have to initialize structs that we don't need,
> which will become a tiny bit more expensive if we switch over to using
> static variables to try and reduce stack usage. (There's runtime code
> to check if the variable has been initialized yet or not).
>
> Signed-off-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
> Reviewed-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> ---
This looks good. I'm still not 100% sold that putting the if() outside
the function is significantly easier to read, but I don't think it's
harder to read either, and getting rid of the function call is
probably worth it.
Reviewed-by: David Gow <davidgow@xxxxxxxxxx>
-- David
> include/kunit/test.h | 21 +++++++++++----------
> lib/kunit/test.c | 13 ++++---------
> 2 files changed, 15 insertions(+), 19 deletions(-)
>
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index b26400731c02..12cabd15449a 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -12,6 +12,7 @@
> #include <kunit/assert.h>
> #include <kunit/try-catch.h>
>
> +#include <linux/compiler.h>
> #include <linux/container_of.h>
> #include <linux/err.h>
> #include <linux/init.h>
> @@ -770,18 +771,18 @@ void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...);
> */
> #define KUNIT_SUCCEED(test) do {} while (0)
>
> -void kunit_do_assertion(struct kunit *test,
> - struct kunit_assert *assert,
> - bool pass,
> - const char *fmt, ...);
> +void kunit_do_failed_assertion(struct kunit *test,
> + struct kunit_assert *assert,
> + const char *fmt, ...);
>
> #define KUNIT_ASSERTION(test, pass, assert_class, INITIALIZER, fmt, ...) do { \
> - struct assert_class __assertion = INITIALIZER; \
> - kunit_do_assertion(test, \
> - &__assertion.assert, \
> - pass, \
> - fmt, \
> - ##__VA_ARGS__); \
> + if (unlikely(!(pass))) { \
> + struct assert_class __assertion = INITIALIZER; \
> + kunit_do_failed_assertion(test, \
> + &__assertion.assert, \
> + fmt, \
> + ##__VA_ARGS__); \
> + } \
> } while (0)
>
>
> diff --git a/lib/kunit/test.c b/lib/kunit/test.c
> index c7ed4aabec04..3a52c321c280 100644
> --- a/lib/kunit/test.c
> +++ b/lib/kunit/test.c
> @@ -275,16 +275,11 @@ static void __noreturn kunit_abort(struct kunit *test)
> WARN_ONCE(true, "Throw could not abort from test!\n");
> }
>
> -void kunit_do_assertion(struct kunit *test,
> - struct kunit_assert *assert,
> - bool pass,
> - const char *fmt, ...)
> +void kunit_do_failed_assertion(struct kunit *test,
> + struct kunit_assert *assert,
> + const char *fmt, ...)
> {
> va_list args;
> -
> - if (pass)
> - return;
> -
> va_start(args, fmt);
>
> assert->message.fmt = fmt;
> @@ -297,7 +292,7 @@ void kunit_do_assertion(struct kunit *test,
> if (assert->type == KUNIT_ASSERTION)
> kunit_abort(test);
> }
> -EXPORT_SYMBOL_GPL(kunit_do_assertion);
> +EXPORT_SYMBOL_GPL(kunit_do_failed_assertion);
>
> void kunit_init_test(struct kunit *test, const char *name, char *log)
> {
> --
> 2.34.1.575.g55b058a8bb-goog
>
