kunit: allow kunit tests to be loaded as a module

As tests are added to kunit, it will become less feasible to execute
all built tests together.  By supporting modular tests we provide
a simple way to do selective execution on a running system; specifying

CONFIG_KUNIT=y
CONFIG_KUNIT_EXAMPLE_TEST=m

...means we can simply "insmod example-test.ko" to run the tests.

To achieve this we need to do the following:

o export the required symbols in kunit
o string-stream tests utilize non-exported symbols so for now we skip
  building them when CONFIG_KUNIT_TEST=m.
o drivers/base/power/qos-test.c contains a few unexported interface
  references, namely freq_qos_read_value() and freq_constraints_init().
  Both of these could be potentially defined as static inline functions
  in include/linux/pm_qos.h, but for now we simply avoid supporting
  module build for that test suite.
o support a new way of declaring test suites.  Because a module cannot
  do multiple late_initcall()s, we provide a kunit_test_suites() macro
  to declare multiple suites within the same module at once.
o some test module names would have been too general ("test-test"
  and "example-test" for kunit tests, "inode-test" for ext4 tests);
  rename these as appropriate ("kunit-test", "kunit-example-test"
  and "ext4-inode-test" respectively).

Also define kunit_test_suite() via kunit_test_suites()
as callers in other trees may need the old definition.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits
Acked-by: David Gow <davidgow@google.com> # For list-test
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 0 insertions, 88 deletions

diff --git a/lib/kunit/example-test.c b/lib/kunit/example-test.c
deleted file mode 100644
index f64a829aa441..000000000000
--- a/lib/kunit/example-test.c
+++ /dev/null
@@ -1,88 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Example KUnit test to show how to use KUnit.
- *
- * Copyright (C) 2019, Google LLC.
- * Author: Brendan Higgins <brendanhiggins@google.com>
- */
-
-#include <kunit/test.h>
-
-/*
- * This is the most fundamental element of KUnit, the test case. A test case
- * makes a set EXPECTATIONs and ASSERTIONs about the behavior of some code; if
- * any expectations or assertions are not met, the test fails; otherwise, the
- * test passes.
- *
- * In KUnit, a test case is just a function with the signature
- * `void (*)(struct kunit *)`. `struct kunit` is a context object that stores
- * information about the current test.
- */
-static void example_simple_test(struct kunit *test)
-{
-	/*
-	 * This is an EXPECTATION; it is how KUnit tests things. When you want
-	 * to test a piece of code, you set some expectations about what the
-	 * code should do. KUnit then runs the test and verifies that the code's
-	 * behavior matched what was expected.
-	 */
-	KUNIT_EXPECT_EQ(test, 1 + 1, 2);
-}
-
-/*
- * This is run once before each test case, see the comment on
- * example_test_suite for more information.
- */
-static int example_test_init(struct kunit *test)
-{
-	kunit_info(test, "initializing\n");
-
-	return 0;
-}
-
-/*
- * Here we make a list of all the test cases we want to add to the test suite
- * below.
- */
-static struct kunit_case example_test_cases[] = {
-	/*
-	 * This is a helper to create a test case object from a test case
-	 * function; its exact function is not important to understand how to
-	 * use KUnit, just know that this is how you associate test cases with a
-	 * test suite.
-	 */
-	KUNIT_CASE(example_simple_test),
-	{}
-};
-
-/*
- * This defines a suite or grouping of tests.
- *
- * Test cases are defined as belonging to the suite by adding them to
- * `kunit_cases`.
- *
- * Often it is desirable to run some function which will set up things which
- * will be used by every test; this is accomplished with an `init` function
- * which runs before each test case is invoked. Similarly, an `exit` function
- * may be specified which runs after every test case and can be used to for
- * cleanup. For clarity, running tests in a test suite would behave as follows:
- *
- * suite.init(test);
- * suite.test_case[0](test);
- * suite.exit(test);
- * suite.init(test);
- * suite.test_case[1](test);
- * suite.exit(test);
- * ...;
- */
-static struct kunit_suite example_test_suite = {
-	.name = "example",
-	.init = example_test_init,
-	.test_cases = example_test_cases,
-};
-
-/*
- * This registers the above test suite telling KUnit that this is a suite of
- * tests that need to be run.
- */
-kunit_test_suite(example_test_suite);