linux/lib/kunit
Daniel Latypov 21957f90b2 kunit: split out part of kunit_assert into a static const
This is per Linus's suggestion in [1].

The issue there is that every KUNIT_EXPECT/KUNIT_ASSERT puts a
kunit_assert object onto the stack. Normally we rely on compilers to
elide this, but when that doesn't work out, this blows up the stack
usage of kunit test functions.

We can move some data off the stack by making it static.
This change introduces a new `struct kunit_loc` to hold the file and
line number and then just passing assert_type (EXPECT or ASSERT) as an
argument.

In [1], it was suggested to also move out the format string as well, but
users could theoretically craft a format string at runtime, so we can't.

This change leaves a copy of `assert_type` in kunit_assert for now
because cleaning up all the macros to not pass it around is a bit more
involved.

Here's an example of the expanded code for KUNIT_FAIL():
if (__builtin_expect(!!(!(false)), 0)) {
  static const struct kunit_loc loc = { .file = ... };
  struct kunit_fail_assert __assertion = { .assert = { .type ...  };
  kunit_do_failed_assertion(test, &loc, KUNIT_EXPECTATION, &__assertion.assert, ...);
};

[1] https://groups.google.com/g/kunit-dev/c/i3fZXgvBrfA/m/VULQg1z6BAAJ

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-01-25 12:49:59 -07:00
..
.kunitconfig kunit: tool: make --kunitconfig accept dirs, add lib/kunit fragment 2021-04-02 14:14:36 -06:00
assert.c kunit: split out part of kunit_assert into a static const 2022-01-25 12:49:59 -07:00
debugfs.c kunit: Support skipped tests 2021-06-25 11:31:03 -06:00
debugfs.h kunit: add debugfs /sys/kernel/debug/kunit/<suite>/results display 2020-03-26 14:07:18 -06:00
executor.c kunit: add 'kunit.action' param to allow listing out tests 2021-10-19 14:18:50 -06:00
executor_test.c kunit: fix too small allocation when using suite-only kunit.filter_glob 2021-10-19 14:18:49 -06:00
Kconfig kunit: add kunit.filter_glob cmdline option to filter suites 2021-02-08 16:09:27 -07:00
kunit-example-test.c kunit: add example test case showing off all the expect macros 2022-01-25 12:49:20 -07:00
kunit-test.c kunit: drop assumption in kunit-log-test about current suite 2021-10-19 14:18:49 -06:00
Makefile kunit: test: create a single centralized executor for all tests 2020-10-09 14:37:34 -06:00
string-stream-test.c kunit: allow kunit tests to be loaded as a module 2020-01-09 16:42:29 -07:00
string-stream.c kunit: generalize kunit_resource API beyond allocated resources 2020-06-26 14:12:00 -06:00
string-stream.h isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
test.c kunit: split out part of kunit_assert into a static const 2022-01-25 12:49:59 -07:00
try-catch-impl.h kunit: hide unexported try-catch interface in try-catch-impl.h 2020-01-09 16:42:09 -07:00
try-catch.c exit: Rename complete_and_exit to kthread_complete_and_exit 2021-12-13 12:04:45 -06:00