Re: [PATCH linux-kselftest/test v6] lib/list-test: add a test for the 'list' doubly linked list

[David Gow <davidgow@google.com>]

On Tue, Oct 29, 2019 at 6:00 AM shuah <shuah@kernel.org> wrote:
> On 10/24/19 4:46 PM, David Gow wrote:
> > Add a KUnit test for the kernel doubly linked list implementation in
> > include/linux/list.h
> >
> > Each test case (list_test_x) is focused on testing the behaviour of the
> > list function/macro 'x'. None of the tests pass invalid lists to these
> > macros, and so should behave identically with DEBUG_LIST enabled and
> > disabled.
> >
> > Note that, at present, it only tests the list_ types (not the
> > singly-linked hlist_), and does not yet test all of the
> > list_for_each_entry* macros (and some related things like
> > list_prepare_entry).
> >
> > Signed-off-by: David Gow <davidgow@google.com>
> > Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
> > Tested-by: Brendan Higgins <brendanhiggins@google.com>
> > ---
> >
> > This revision addresses Brendan's comments in
> > https://lore.kernel.org/linux-kselftest/20191023220248.GA55483@google.com/
> >
> > Specifically:
> > - Brendan's Reviewed-by/Tested-by being included in the description.
> > - A couple of trailing tabs in Kconfig.debug & list-test.c
> > - Reformatting of previously >80 character lines.
> >
> >
> > Earlier versions of this patchset can be found:
> >
> > v5:
> > https://lore.kernel.org/linux-kselftest/20191022221322.122788-1-davidgow@google.com/
> > v4:
> > https://lore.kernel.org/linux-kselftest/20191018215549.65000-1-davidgow@google.com/
> > v3:
> > https://lore.kernel.org/linux-kselftest/20191016215707.95317-1-davidgow@google.com/
> > v2:
> > https://lore.kernel.org/linux-kselftest/20191010185631.26541-1-davidgow@google.com/
> > v1:
> > https://lore.kernel.org/linux-kselftest/20191007213633.92565-1-davidgow@google.com/
> >
>
> CHECK: Unnecessary parentheses around test_struct.list
> #699: FILE: lib/list-test.c:510:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct, list_entry(&(test_struct.list),
>
> CHECK: Alignment should match open parenthesis
> #700: FILE: lib/list-test.c:511:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct, list_entry(&(test_struct.list),
> +                               struct list_test_struct, list));
>
> CHECK: Please don't use multiple blank lines
> #711: FILE: lib/list-test.c:522:
> +
> +
>
> CHECK: Alignment should match open parenthesis
> #713: FILE: lib/list-test.c:524:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct1, list_first_entry(&list,
> +                               struct list_test_struct, list));
>
> CHECK: Please don't use multiple blank lines
> #724: FILE: lib/list-test.c:535:
> +
> +
>
> CHECK: Alignment should match open parenthesis
> #726: FILE: lib/list-test.c:537:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct2, list_last_entry(&list,
> +                               struct list_test_struct, list));
>
> CHECK: Alignment should match open parenthesis
> #735: FILE: lib/list-test.c:546:
> +       KUNIT_EXPECT_FALSE(test, list_first_entry_or_null(&list,
> +                               struct list_test_struct, list));
>
> CHECK: Alignment should match open parenthesis
> #741: FILE: lib/list-test.c:552:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct1,
> +                       list_first_entry_or_null(&list,
>
> CHECK: Alignment should match open parenthesis
> #742: FILE: lib/list-test.c:553:
> +                       list_first_entry_or_null(&list,
> +                               struct list_test_struct, list));
>
> CHECK: Please don't use multiple blank lines
> #753: FILE: lib/list-test.c:564:
> +
> +
>
> CHECK: Alignment should match open parenthesis
> #755: FILE: lib/list-test.c:566:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct2, list_next_entry(&test_struct1,
> +                               list));
>
> CHECK: Please don't use multiple blank lines
> #766: FILE: lib/list-test.c:577:
> +
> +
>
> CHECK: Alignment should match open parenthesis
> #768: FILE: lib/list-test.c:579:
> +       KUNIT_EXPECT_PTR_EQ(test, &test_struct1, list_prev_entry(&test_struct2,
> +                               list));
>
> ERROR: that open brace { should be on the previous line
> #789: FILE: lib/list-test.c:600:
> +static void list_test_list_for_each_prev(struct kunit *test)
> +{
>
> ERROR: that open brace { should be on the previous line
> #807: FILE: lib/list-test.c:618:
> +static void list_test_list_for_each_safe(struct kunit *test)
> +{
>
> CHECK: Please don't use multiple blank lines
> #813: FILE: lib/list-test.c:624:
> +
> +
>
> ERROR: that open brace { should be on the previous line
> #828: FILE: lib/list-test.c:639:
> +static void list_test_list_for_each_prev_safe(struct kunit *test)
> +{
>
> ERROR: that open brace { should be on the previous line
> #848: FILE: lib/list-test.c:659:
> +static void list_test_list_for_each_entry(struct kunit *test)
> +{
>
> ERROR: that open brace { should be on the previous line
> #869: FILE: lib/list-test.c:680:
> +static void list_test_list_for_each_entry_reverse(struct kunit *test)
> +{
>
>
> I am seeing these error and warns. As per our hallway conversation, the
> "for_each*" in the test naming is tripping up checkpatch.pl
>
> For now you can change the name a bit to not trip checkpatch and maybe
> explore fixing checkpatch to differentiate between function names
> with "for_each" in them vs. the actual for_each usages in the code.

Thanks, Shuah.

Yes, the problem here is that checkpatch.pl believes that anything
with "for_each" in its name must be a loop, so expects that the open
brace is placed on the same line as for a for loop.

Longer term, I think it'd be nicer, naming-wise, to fix or work around
this issue in checkpatch.pl itself, as that'd allow the tests to
continue to follow a naming pattern of "list_test_[x]", where [x] is
the name of the function/macro being tested. Of course, short of
trying to fit a whole C parser in checkpatch.pl, that's going to
involve some compromises as well.

In the meantime, I'm sending out v7 which replaces "for_each" with
"for__each" (adding the extra underscore), so that checkpatch is
happy.

Cheers,
-- David