Add basic test coverage for files that don't require any config options:
* gcd.c
* lcm.c
* int_sqrt.c
* reciprocal_div.c
(Ignored int_pow.c since it's a simple textbook algorithm.)
These tests aren't particularly interesting, but they
* provide short and simple examples of parameterized tests
* provide a place to add tests for any new files in this dir
* are written so adding new test cases to cover edge cases should be easy
Signed-off-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
---
Changes since v3:
* fix `checkpatch.pl --strict` warnings
* add test cases for gcd(0,0) and lcm(0,0)
* minor: don't test both gcd(a,b) and gcd(b,a) when a == b
Changes since v2: mv math_test.c => math_kunit.c
Changes since v1:
* Rebase and rewrite to use the new parameterized testing support.
* misc: fix overflow in literal and inline int_sqrt format string.
* related: commit 1f0e943df68a ("Documentation: kunit: provide guidance
for testing many inputs") was merged explaining the patterns shown here.
* there's an in-flight patch to update it for parameterized testing.
v1: https://lore.kernel.org/lkml/20201019224556.3536790-1-dlatypov@xxxxxxxxxx/
---
lib/math/Kconfig | 5 +
lib/math/Makefile | 2 +
lib/math/math_kunit.c | 214 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 221 insertions(+)
create mode 100644 lib/math/math_kunit.c
diff --git a/lib/math/Kconfig b/lib/math/Kconfig
index f19bc9734fa7..6ba8680439c1 100644
--- a/lib/math/Kconfig
+++ b/lib/math/Kconfig
@@ -15,3 +15,8 @@ config PRIME_NUMBERS
config RATIONAL
bool
+
+config MATH_KUNIT_TEST
+ tristate "KUnit test for lib/math" if !KUNIT_ALL_TESTS
+ default KUNIT_ALL_TESTS
+ depends on KUNIT
diff --git a/lib/math/Makefile b/lib/math/Makefile
index be6909e943bd..30abb7a8d564 100644
--- a/lib/math/Makefile
+++ b/lib/math/Makefile
@@ -4,3 +4,5 @@ obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o
obj-$(CONFIG_CORDIC) += cordic.o
obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o
obj-$(CONFIG_RATIONAL) += rational.o
+
+obj-$(CONFIG_MATH_KUNIT_TEST) += math_kunit.o
diff --git a/lib/math/math_kunit.c b/lib/math/math_kunit.c
new file mode 100644
index 000000000000..fed15ade8fb2
--- /dev/null
+++ b/lib/math/math_kunit.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simple KUnit suite for math helper funcs that are always enabled.
+ *
+ * Copyright (C) 2020, Google LLC.
+ * Author: Daniel Latypov <dlatypov@xxxxxxxxxx>
+ */
+
+#include <kunit/test.h>
+#include <linux/gcd.h>
+#include <linux/kernel.h>
+#include <linux/lcm.h>
+#include <linux/reciprocal_div.h>
+
+/* Generic test case for unsigned long inputs. */
+struct test_case {
+ unsigned long a, b;
+ unsigned long result;
+};
+
+static struct test_case gcd_cases[] = {
+ {
+ .a = 0, .b = 0,
+ .result = 0,
+ },
+ {
+ .a = 0, .b = 1,
+ .result = 1,
+ },
+ {
+ .a = 2, .b = 2,
+ .result = 2,
+ },
+ {
+ .a = 2, .b = 4,
+ .result = 2,
+ },
+ {
+ .a = 3, .b = 5,
+ .result = 1,
+ },
+ {
+ .a = 3 * 9, .b = 3 * 5,
+ .result = 3,
+ },
+ {
+ .a = 3 * 5 * 7, .b = 3 * 5 * 11,
+ .result = 15,
+ },
+ {
+ .a = 1 << 21,
+ .b = (1 << 21) - 1,
+ .result = 1,
+ },
+};
+
+KUNIT_ARRAY_PARAM(gcd, gcd_cases, NULL);
+
+static void gcd_test(struct kunit *test)
+{
+ const char *message_fmt = "gcd(%lu, %lu)";
+ const struct test_case *test_param = test->param_value;
+
+ KUNIT_EXPECT_EQ_MSG(test, test_param->result,
+ gcd(test_param->a, test_param->b),
+ message_fmt, test_param->a,
+ test_param->b);
+
+ if (test_param->a == test_param->b)
+ return;
+
+ /* gcd(a,b) == gcd(b,a) */
+ KUNIT_EXPECT_EQ_MSG(test, test_param->result,
+ gcd(test_param->b, test_param->a),
+ message_fmt, test_param->b,
+ test_param->a);
+}
+
+static struct test_case lcm_cases[] = {
+ {
+ .a = 0, .b = 0,
+ .result = 0,
+ },
+ {
+ .a = 0, .b = 1,
+ .result = 0,
+ },
+ {
+ .a = 1, .b = 2,
+ .result = 2,
+ },
+ {
+ .a = 2, .b = 2,
+ .result = 2,
+ },
+ {
+ .a = 3 * 5, .b = 3 * 7,
+ .result = 3 * 5 * 7,
+ },
+};
+
+KUNIT_ARRAY_PARAM(lcm, lcm_cases, NULL);
+
+static void lcm_test(struct kunit *test)
+{
+ const char *message_fmt = "lcm(%lu, %lu)";
+ const struct test_case *test_param = test->param_value;
+
+ KUNIT_EXPECT_EQ_MSG(test, test_param->result,
+ lcm(test_param->a, test_param->b),
+ message_fmt, test_param->a,
+ test_param->b);
+
+ if (test_param->a == test_param->b)
+ return;
+
+ /* lcm(a,b) == lcm(b,a) */
+ KUNIT_EXPECT_EQ_MSG(test, test_param->result,
+ lcm(test_param->b, test_param->a),
+ message_fmt, test_param->b,
+ test_param->a);
+}
+
+static struct test_case int_sqrt_cases[] = {
+ {
+ .a = 0,
+ .result = 0,
+ },
+ {
+ .a = 1,
+ .result = 1,
+ },
+ {
+ .a = 4,
+ .result = 2,
+ },
+ {
+ .a = 5,
+ .result = 2,
+ },
+ {
+ .a = 8,
+ .result = 2,
+ },
+ {
+ .a = 1UL << 30,
+ .result = 1UL << 15,
+ },
+};
+
+KUNIT_ARRAY_PARAM(int_sqrt, int_sqrt_cases, NULL);
+
+static void int_sqrt_test(struct kunit *test)
+{
+ const struct test_case *test_param = test->param_value;
+
+ KUNIT_EXPECT_EQ_MSG(test, int_sqrt(test_param->a),
+ test_param->result, "sqrt(%lu)",
+ test_param->a);
+}
+
+struct reciprocal_test_case {
+ u32 a, b;
+ u32 result;
+};
+
+static struct reciprocal_test_case reciprocal_div_cases[] = {
+ {
+ .a = 0, .b = 1,
+ .result = 0,
+ },
+ {
+ .a = 42, .b = 20,
+ .result = 2,
+ },
+ {
+ .a = 42, .b = 9999,
+ .result = 0,
+ },
+ {
+ .a = (1 << 16), .b = (1 << 14),
+ .result = 1 << 2,
+ },
+};
+
+KUNIT_ARRAY_PARAM(reciprocal_div, reciprocal_div_cases, NULL);
+
+static void reciprocal_div_test(struct kunit *test)
+{
+ const struct reciprocal_test_case *test_param = test->param_value;
+ struct reciprocal_value rv = reciprocal_value(test_param->b);
+
+ KUNIT_EXPECT_EQ_MSG(test, test_param->result,
+ reciprocal_divide(test_param->a, rv),
+ "reciprocal_divide(%u, %u)",
+ test_param->a, test_param->b);
+}
+
+static struct kunit_case math_test_cases[] = {
+ KUNIT_CASE_PARAM(gcd_test, gcd_gen_params),
+ KUNIT_CASE_PARAM(lcm_test, lcm_gen_params),
+ KUNIT_CASE_PARAM(int_sqrt_test, int_sqrt_gen_params),
+ KUNIT_CASE_PARAM(reciprocal_div_test, reciprocal_div_gen_params),
+ {}
+};
+
+static struct kunit_suite math_test_suite = {
+ .name = "lib-math",
+ .test_cases = math_test_cases,
+};
+
+kunit_test_suites(&math_test_suite);
+
+MODULE_LICENSE("GPL v2");
base-commit: 4fa56ad0d12e24df768c98bffe9039f915d1bc02
--
2.31.1.295.g9ea45b61b8-goog
