kunit: remove format func from struct kunit_assert, get it to 0 bytes

Each calll to a KUNIT_EXPECT_*() macro creates a local variable which
contains a struct kunit_assert.

Normally, we'd hope the compiler would be able to optimize this away,
but we've seen cases where it hasn't, see
https://groups.google.com/g/kunit-dev/c/i3fZXgvBrfA/m/GbrMNej2BAAJ.

In changes like commit 21957f90b28f ("kunit: split out part of
kunit_assert into a static const"), we've moved more and more parts out
of struct kunit_assert and its children types (kunit_binary_assert).

This patch removes the final field and gets us to:
  sizeof(struct kunit_assert) == 0
  sizeof(struct kunit_binary_assert) == 24 (on UML x86_64).

This also reduces the amount of macro plumbing going on at the cost of
passing in one more arg to the base KUNIT_ASSERTION macro and
kunit_do_failed_assertion().

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

1 files changed, 4 insertions, 3 deletions

diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 46471bda351e..90640a43cf62 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -258,7 +258,7 @@ static void kunit_print_string_stream(struct kunit *test,
 
 static void kunit_fail(struct kunit *test, const struct kunit_loc *loc,
 		       enum kunit_assert_type type, const struct kunit_assert *assert,
-		       const struct va_format *message)
+		       assert_format_t assert_format, const struct va_format *message)
 {
 	struct string_stream *stream;
 
@@ -274,7 +274,7 @@ static void kunit_fail(struct kunit *test, const struct kunit_loc *loc,
 	}
 
 	kunit_assert_prologue(loc, type, stream);
-	assert->format(assert, message, stream);
+	assert_format(assert, message, stream);
 
 	kunit_print_string_stream(test, stream);
 
@@ -298,6 +298,7 @@ void kunit_do_failed_assertion(struct kunit *test,
 			       const struct kunit_loc *loc,
 			       enum kunit_assert_type type,
 			       const struct kunit_assert *assert,
+			       assert_format_t assert_format,
 			       const char *fmt, ...)
 {
 	va_list args;
@@ -307,7 +308,7 @@ void kunit_do_failed_assertion(struct kunit *test,
 	message.fmt = fmt;
 	message.va = &args;
 
-	kunit_fail(test, loc, type, assert, &message);
+	kunit_fail(test, loc, type, assert, assert_format, &message);
 
 	va_end(args);