Re: [PATCH 2/2] kunit: Add example of kunit_activate_static_stub() with pointer-to-function

On Mon, Dec 18, 2023 at 11:10 AM Richard Fitzgerald rf@opensource.cirrus.com wrote:

Adds a variant of example_static_stub_test() that shows use of a pointer-to-function with kunit_activate_static_stub().

A const pointer to the add_one() function is declared. This pointer-to-function is passed to kunit_activate_static_stub() and kunit_deactivate_static_stub() instead of passing add_one directly.

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com

Hello!

This test looks good to me. However, I had issues applying this patch so I think it needs rebasing due to the newest additions to kselftest/kunit. But otherwise this patch looks good other than my very small comment below.

Thanks! -Rae

---

lib/kunit/kunit-example-test.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)

diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c index d2f7a3c62c18..9e57f341dc37 100644 --- a/lib/kunit/kunit-example-test.c +++ b/lib/kunit/kunit-example-test.c @@ -168,6 +168,8 @@ static int subtract_one(int i) return i - 1; }

+static int (* const add_one_fn_ptr)(int i) = add_one;

This is a bit of a nit but could you add a brief comment above this pointer definition? This would then match the commenting on the other functions in kunit-example-test and provide more context for those looking at the example tests.

/*

• This test shows the use of static stubs.

*/ @@ -187,6 +189,30 @@ static void example_static_stub_test(struct kunit *test) KUNIT_EXPECT_EQ(test, add_one(1), 2); }

+/*

• • This test shows the use of static stubs when the function being
• • replaced is provided as a pointer-to-function instead of the
• • actual function. This is useful for providing access to static
• • functions in a module by exporting a pointer to that function
• • instead of having to change the static function to a non-static
• • exported function.
• */

+static void example_static_stub_using_fn_ptr_test(struct kunit *test) +{

•   /* By default, function is not stubbed. */
  

•   KUNIT_EXPECT_EQ(test, add_one(1), 2);
  

•   /* Replace add_one() with subtract_one(). */
  

•   kunit_activate_static_stub(test, add_one_fn_ptr, subtract_one);
  

•   /* add_one() is now replaced. */
  

•   KUNIT_EXPECT_EQ(test, add_one(1), 0);
  

•   /* Return add_one() to normal. */
  

•   kunit_deactivate_static_stub(test, add_one_fn_ptr);
  

•   KUNIT_EXPECT_EQ(test, add_one(1), 2);
  

+}

static const struct example_param { int value; } example_params_array[] = { @@ -245,6 +271,7 @@ static struct kunit_case example_test_cases[] = { KUNIT_CASE(example_mark_skipped_test), KUNIT_CASE(example_all_expect_macros_test), KUNIT_CASE(example_static_stub_test),

•   KUNIT_CASE(example_static_stub_using_fn_ptr_test),
    KUNIT_CASE_PARAM(example_params_test, example_gen_params),
    KUNIT_CASE_SLOW(example_slow_test),
    {}
  

-- 2.30.2