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Diffstat (limited to 'Documentation/dev-tools/kunit/usage.rst')
| -rw-r--r-- | Documentation/dev-tools/kunit/usage.rst | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst index 22416ebb94ab..48f8196d5aad 100644 --- a/Documentation/dev-tools/kunit/usage.rst +++ b/Documentation/dev-tools/kunit/usage.rst @@ -641,17 +641,23 @@ as shown in next section: *Accessing The Current Test*. Accessing The Current Test -------------------------- -In some cases, we need to call test-only code from outside the test file. -For example, see example in section *Injecting Test-Only Code* or if -we are providing a fake implementation of an ops struct. Using -``kunit_test`` field in ``task_struct``, we can access it via -``current->kunit_test``. +In some cases, we need to call test-only code from outside the test file. This +is helpful, for example, when providing a fake implementation of a function, or +to fail any current test from within an error handler. +We can do this via the ``kunit_test`` field in ``task_struct``, which we can +access using the ``kunit_get_current_test()`` function in ``kunit/test-bug.h``. -The example below includes how to implement "mocking": +``kunit_get_current_test()`` is safe to call even if KUnit is not enabled. If +KUnit is not enabled, was built as a module (``CONFIG_KUNIT=m``), or no test is +running in the current task, it will return ``NULL``. This compiles down to +either a no-op or a static key check, so will have a negligible performance +impact when no test is running. + +The example below uses this to implement a "mock" implementation of a function, ``foo``: .. code-block:: c - #include <linux/sched.h> /* for current */ + #include <kunit/test-bug.h> /* for kunit_get_current_test */ struct test_data { int foo_result; @@ -660,7 +666,7 @@ The example below includes how to implement "mocking": static int fake_foo(int arg) { - struct kunit *test = current->kunit_test; + struct kunit *test = kunit_get_current_test(); struct test_data *test_data = test->priv; KUNIT_EXPECT_EQ(test, test_data->want_foo_called_with, arg); @@ -691,7 +697,7 @@ Each test can have multiple resources which have string names providing the same flexibility as a ``priv`` member, but also, for example, allowing helper functions to create resources without conflicting with each other. It is also possible to define a clean up function for each resource, making it easy to -avoid resource leaks. For more information, see Documentation/dev-tools/kunit/api/test.rst. +avoid resource leaks. For more information, see Documentation/dev-tools/kunit/api/resource.rst. Failing The Current Test ------------------------ @@ -719,3 +725,9 @@ structures as shown below: static void my_debug_function(void) { } #endif +``kunit_fail_current_test()`` is safe to call even if KUnit is not enabled. If +KUnit is not enabled, was built as a module (``CONFIG_KUNIT=m``), or no test is +running in the current task, it will do nothing. This compiles down to either a +no-op or a static key check, so will have a negligible performance impact when +no test is running. + |