linux_kselftest-kunit-6.12-rc1

This kunit update for Linux 6.12-rc1 consists of:
 
 -- a new int_pow test suite
 -- documentation update to clarify filename best practices
 -- kernel-doc fix for EXPORT_SYMBOL_IF_KUNIT
 -- change to build compile_commands.json automatically instead
    of requiring a manual build.
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Merge tag 'linux_kselftest-kunit-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit updates from Shuah Khan:

 - a new int_pow test suite

 - documentation update to clarify filename best practices

 - kernel-doc fix for EXPORT_SYMBOL_IF_KUNIT

 - change to build compile_commands.json automatically instead of
   requiring a manual build

* tag 'linux_kselftest-kunit-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  lib/math: Add int_pow test suite
  kunit: tool: Build compile_commands.json
  kunit: Fix kernel-doc for EXPORT_SYMBOL_IF_KUNIT
  Documentation: KUnit: Update filename best practices

Documentation/dev-tools/kunit/style.rst

@@ -188,15 +188,26 @@ For example, a Kconfig entry might look like:
 Test File and Module Names
 ==========================
 
-KUnit tests can often be compiled as a module. These modules should be named
-after the test suite, followed by ``_test``. If this is likely to conflict with
-non-KUnit tests, the suffix ``_kunit`` can also be used.
+KUnit tests are often compiled as a separate module. To avoid conflicting
+with regular modules, KUnit modules should be named after the test suite,
+followed by ``_kunit`` (e.g. if "foobar" is the core module, then
+"foobar_kunit" is the KUnit test module).
 
-The easiest way of achieving this is to name the file containing the test suite
-``<suite>_test.c`` (or, as above, ``<suite>_kunit.c``). This file should be
-placed next to the code under test.
+Test source files, whether compiled as a separate module or an
+``#include`` in another source file, are best kept in a ``tests/``
+subdirectory to not conflict with other source files (e.g. for
+tab-completion).
+
+Note that the ``_test`` suffix has also been used in some existing
+tests. The ``_kunit`` suffix is preferred, as it makes the distinction
+between KUnit and non-KUnit tests clearer.
+
+So for the common case, name the file containing the test suite
+``tests/<suite>_kunit.c``. The ``tests`` directory should be placed at
+the same level as the code under test. For example, tests for
+``lib/string.c`` live in ``lib/tests/string_kunit.c``.
 
 If the suite name contains some or all of the name of the test's parent
-directory, it may make sense to modify the source filename to reduce redundancy.
-For example, a ``foo_firmware`` suite could be in the ``foo/firmware_test.c``
-file.
+directory, it may make sense to modify the source filename to reduce
+redundancy. For example, a ``foo_firmware`` suite could be in the
+``foo/tests/firmware_kunit.c`` file.

include/kunit/visibility.h

@@ -22,6 +22,7 @@
      * EXPORTED_FOR_KUNIT_TESTING namespace only if CONFIG_KUNIT is
      * enabled. Must use MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING)
      * in test file in order to use symbols.
+     * @symbol: the symbol identifier to export
      */
     #define EXPORT_SYMBOL_IF_KUNIT(symbol) EXPORT_SYMBOL_NS(symbol, \
 	    EXPORTED_FOR_KUNIT_TESTING)

lib/Kconfig.debug

@@ -3059,3 +3059,19 @@ config RUST_KERNEL_DOCTESTS
 endmenu # "Rust"
 
 endmenu # Kernel hacking
+
+config INT_POW_TEST
+	tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This option enables the KUnit test suite for the int_pow function,
+	  which performs integer exponentiation. The test suite is designed to
+	  verify that the implementation of int_pow correctly computes the power
+	  of a given base raised to a given exponent.
+
+	  Enabling this option will include tests that check various scenarios
+	  and edge cases to ensure the accuracy and reliability of the exponentiation
+	  function.
+
+	  If unsure, say N

lib/math/Makefile

@@ -5,5 +5,6 @@ obj-$(CONFIG_CORDIC)		+= cordic.o
 obj-$(CONFIG_PRIME_NUMBERS)	+= prime_numbers.o
 obj-$(CONFIG_RATIONAL)		+= rational.o
 
+obj-$(CONFIG_INT_POW_TEST)  += tests/int_pow_kunit.o
 obj-$(CONFIG_TEST_DIV64)	+= test_div64.o
 obj-$(CONFIG_RATIONAL_KUNIT_TEST) += rational-test.o

lib/math/tests/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_INT_POW_TEST) += int_pow_kunit.o

lib/math/tests/int_pow_kunit.c

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <kunit/test.h>
+#include <linux/math.h>
+
+struct test_case_params {
+	u64 base;
+	unsigned int exponent;
+	u64 expected_result;
+	const char *name;
+};
+
+static const struct test_case_params params[] = {
+	{ 64, 0, 1, "Power of zero" },
+	{ 64, 1, 64, "Power of one"},
+	{ 0, 5, 0, "Base zero" },
+	{ 1, 64, 1, "Base one" },
+	{ 2, 2, 4, "Two squared"},
+	{ 2, 3, 8, "Two cubed"},
+	{ 5, 5, 3125, "Five raised to the fifth power" },
+	{ U64_MAX, 1, U64_MAX, "Max base" },
+	{ 2, 63, 9223372036854775808ULL, "Large result"},
+};
+
+static void get_desc(const struct test_case_params *tc, char *desc)
+{
+	strscpy(desc, tc->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(int_pow, params, get_desc);
+
+static void int_pow_test(struct kunit *test)
+{
+	const struct test_case_params *tc = (const struct test_case_params *)test->param_value;
+
+	KUNIT_EXPECT_EQ(test, tc->expected_result, int_pow(tc->base, tc->exponent));
+}
+
+static struct kunit_case math_int_pow_test_cases[] = {
+	KUNIT_CASE_PARAM(int_pow_test, int_pow_gen_params),
+	{}
+};
+
+static struct kunit_suite int_pow_test_suite = {
+	.name = "math-int_pow",
+	.test_cases = math_int_pow_test_cases,
+};
+
+kunit_test_suites(&int_pow_test_suite);
+
+MODULE_DESCRIPTION("math.int_pow KUnit test suite");
+MODULE_LICENSE("GPL");

tools/testing/kunit/kunit_kernel.py

@@ -72,7 +72,8 @@ class LinuxSourceTreeOperations:
 			raise ConfigError(e.output.decode())
 
 	def make(self, jobs: int, build_dir: str, make_options: Optional[List[str]]) -> None:
-		command = ['make', 'ARCH=' + self._linux_arch, 'O=' + build_dir, '--jobs=' + str(jobs)]
+		command = ['make', 'all', 'compile_commands.json', 'ARCH=' + self._linux_arch,
+			   'O=' + build_dir, '--jobs=' + str(jobs)]
 		if make_options:
 			command.extend(make_options)
 		if self._cross_compile: