Re: [PATCH 1/2] testing/selftests: Add tests for the is_signed_type() macro

[Isabella Basso]

Hi, Bart,

Glad to see some more KUnit tests making it inside of the kernel’s lib folder :).

> Am 26/08/2022 um 1:21 PM schrieb Bart Van Assche <bvanassche@xxxxxxx>:
> 
> Although not documented, is_signed_type() must support the 'bool' and
> pointer types next to scalar and enumeration types. Add a selftest that
> verifies that this macro handles all supported types correctly.
> 
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Isabella Basso <isabbasso@xxxxxxxxxx>
> Cc: "Jason A. Donenfeld" <Jason@xxxxxxxxx>
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> Cc: Sander Vanheule <sander@xxxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Vlastimil Babka <vbabka@xxxxxxx>
> Cc: Yury Norov <yury.norov@xxxxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> lib/Kconfig.debug         | 12 ++++++++++
> lib/Makefile              |  1 +
> lib/is_signed_type_test.c | 48 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 61 insertions(+)
> create mode 100644 lib/is_signed_type_test.c
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 072e4b289c13..36455953d306 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2506,6 +2506,18 @@ config MEMCPY_KUNIT_TEST
> 
> 	  If unsure, say N.
> 
> +config IS_SIGNED_TYPE_KUNIT_TEST
> +	tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
> +	depends on KUNIT
> +	default KUNIT_ALL_TESTS
> +	help
> +	  Builds unit tests for the is_signed_type() macro.
> +
> +	  For more information on KUnit and unit tests in general please refer
> +	  to the KUnit documentation in Documentation/dev-tools/kunit/.
> +
> +	  If unsure, say N.
> +
> config OVERFLOW_KUNIT_TEST
> 	tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
> 	depends on KUNIT
> diff --git a/lib/Makefile b/lib/Makefile
> index 5927d7fa0806..70176ff17023 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -377,6 +377,7 @@ obj-$(CONFIG_BITS_TEST) += test_bits.o
> obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o
> obj-$(CONFIG_SLUB_KUNIT_TEST) += slub_kunit.o
> obj-$(CONFIG_MEMCPY_KUNIT_TEST) += memcpy_kunit.o
> +obj-$(CONFIG_IS_SIGNED_TYPE_KUNIT_TEST) += is_signed_type_test.o
> obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow_kunit.o
> CFLAGS_stackinit_kunit.o += $(call cc-disable-warning, switch-unreachable)
> obj-$(CONFIG_STACKINIT_KUNIT_TEST) += stackinit_kunit.o
> diff --git a/lib/is_signed_type_test.c b/lib/is_signed_type_test.c
> new file mode 100644
> index 000000000000..f2eedb1f0935
> --- /dev/null
> +++ b/lib/is_signed_type_test.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + *	./tools/testing/kunit/kunit.py run is_signed_type [--raw_output]
> + */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <kunit/test.h>
> +#include <linux/overflow.h>

Nit: I don’t know if that makes a huge difference but you might include
`<linux/compiler.h>` directly to make the final object smaller. Of course, that
would ideally be a change happening in 2/2 but that was already merged :).

> +
> +enum unsigned_enum {
> +	constant_a = 3,
> +};
> +
> +enum signed_enum {
> +	constant_b = -1,
> +	constant_c = 2,
> +};
> +
> +static void is_signed_type_test(struct kunit *test)
> +{
> +	KUNIT_EXPECT_EQ(test, is_signed_type(bool), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(signed char), true);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(unsigned char), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(int), true);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(unsigned int), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(long), true);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(unsigned long), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(long long), true);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(unsigned long long), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(enum unsigned_enum), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(enum signed_enum), true);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(void *), false);
> +	KUNIT_EXPECT_EQ(test, is_signed_type(const char *), false);
> +}
> +
> +static struct kunit_case is_signed_type_test_cases[] = {
> +	KUNIT_CASE(is_signed_type_test),
> +	{}
> +};
> +
> +static struct kunit_suite is_signed_type_test_suite = {
> +	.name = "is_signed_type",
> +	.test_cases = is_signed_type_test_cases,
> +};
> +
> +kunit_test_suite(is_signed_type_test_suite);
> +
> +MODULE_LICENSE("Dual MIT/GPL“);

Tested-by: Isabella Basso <isabbasso@xxxxxxxxxx>

Cheers,
--
Isabella Basso