On Tue, Jul 29, 2025 at 3:37 PM Marie Zhussupova <marie...@google.com> wrote:
>
> Introduce `example_params_test_with_init_dynamic_arr`. This new
> KUnit test demonstrates directly assigning a dynamic parameter
> array using the `kunit_register_params_array` macro. It highlights the
> use of `param_init` and `param_exit` for proper initialization and
> cleanup, and their registration to the test with
> `KUNIT_CASE_PARAM_WITH_INIT`.
>
> Signed-off-by: Marie Zhussupova <marie...@google.com>
Hello!
This test is interesting and complex. I am very happy to see this test
accepted. I think it is a good demonstration of the new parameterized
test features.
Reviewed-by: Rae Moar <rm...@google.com>
Thanks!
-Rae
> ---
> lib/kunit/kunit-example-test.c | 95 ++++++++++++++++++++++++++++++++++
> 1 file changed, 95 insertions(+)
>
> diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
> index 5bf559e243f6..3ab121d81bf6 100644
> --- a/lib/kunit/kunit-example-test.c
> +++ b/lib/kunit/kunit-example-test.c
> @@ -387,6 +387,98 @@ static void example_params_test_with_init(struct kunit
> *test)
> kunit_put_resource(res);
> }
>
> +/*
> + * Helper function to create a parameter array of Fibonacci numbers. This
> example
> + * highlights a parameter generation scenario that is:
> + * 1. Not feasible to fully pre-generate at compile time.
> + * 2. Challenging to implement with a standard 'generate_params' function,
> + * as it typically only provides the immediately 'prev' parameter, while
> + * Fibonacci requires access to two preceding values for calculation.
> + */
> +static void *make_fibonacci_params(int seq_size)
> +{
> + int *seq;
> +
> + if (seq_size <= 0)
> + return NULL;
> +
> + seq = kmalloc_array(seq_size, sizeof(int), GFP_KERNEL);
> +
> + if (!seq)
> + return NULL;
> +
> + if (seq_size >= 1)
> + seq[0] = 0;
> + if (seq_size >= 2)
> + seq[1] = 1;
> + for (int i = 2; i < seq_size; i++)
> + seq[i] = seq[i - 1] + seq[i - 2];
> + return seq;
> +}
> +
> +/*
> + * This is an example of a function that provides a description for each of
> the
> + * parameters.
> + */
> +static void example_param_dynamic_arr_get_desc(const void *p, char *desc)
> +{
> + const int *fib_num = p;
> +
> + snprintf(desc, KUNIT_PARAM_DESC_SIZE, "fibonacci param: %d",
> *fib_num);
> +}
> +
> +/*
> + * Example of a parameterized test init function that registers a dynamic
> array.
> + */
> +static int example_param_init_dynamic_arr(struct kunit *test)
> +{
> + int seq_size = 6;
> + int *fibonacci_params = make_fibonacci_params(seq_size);
> +
> + if (!fibonacci_params)
> + return -ENOMEM;
> +
> + /*
> + * Passes the dynamic parameter array information to the parent
> struct kunit.
> + * The array and its metadata will be stored in
> test->parent->params_data.
> + * The array itself will be located in params_data.params.
> + */
> + kunit_register_params_array(test, fibonacci_params, seq_size,
> + example_param_dynamic_arr_get_desc);
> + return 0;
> +}
> +
> +/**
> + * Function to clean up the parameterized test's parent kunit struct if
> + * there were custom allocations.
> + */
> +static void example_param_exit_dynamic_arr(struct kunit *test)
> +{
> + /*
> + * We allocated this array, so we need to free it.
> + * Since the parent parameter instance is passed here,
> + * we can directly access the array via `test->params_data.params`
> + * instead of `test->parent->params_data.params`.
> + */
> + kfree(test->params_data.params);
> +}
> +
> +/*
> + * Example of test that uses the registered dynamic array to perform
> assertions
> + * and expectations.
> + */
> +static void example_params_test_with_init_dynamic_arr(struct kunit *test)
> +{
> + const int *param = test->param_value;
> + int param_val;
> +
> + /* By design, param pointer will not be NULL. */
> + KUNIT_ASSERT_NOT_NULL(test, param);
> +
> + param_val = *param;
> + KUNIT_EXPECT_EQ(test, param_val - param_val, 0);
> +}
> +
> /*
> * Here we make a list of all the test cases we want to add to the test suite
> * below.
> @@ -408,6 +500,9 @@ static struct kunit_case example_test_cases[] = {
> KUNIT_CASE_PARAM(example_params_test, example_gen_params),
> KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init, NULL,
> example_param_init, NULL),
> + KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init_dynamic_arr,
> NULL,
> + example_param_init_dynamic_arr,
> + example_param_exit_dynamic_arr),
> KUNIT_CASE_SLOW(example_slow_test),
> {}
> };
> --
> 2.50.1.552.g942d659e1b-goog
>
