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@xxxxxxxxxxxxxxxxxxxxx>
---
V2: Added comment for add_one_fn_ptr.
---
lib/kunit/kunit-example-test.c | 35 ++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
index 359dbee10201..798924f7cc86 100644
--- a/lib/kunit/kunit-example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -168,6 +168,16 @@ static int subtract_one(int i)
return i - 1;
}
+/*
+ * If the function to be replaced is static within a module it is
+ * useful to export a pointer to that function instead of having
+ * to change the static function to a non-static exported function.
+ *
+ * This pointer simulates a module exporting a pointer to a static
+ * function.
+ */
+static int (* const add_one_fn_ptr)(int i) = add_one;
+
/*
* This test shows the use of static stubs.
*/
@@ -187,6 +197,30 @@ 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[] = {
@@ -259,6 +293,7 @@ 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(example_priv_test),
KUNIT_CASE_PARAM(example_params_test, example_gen_params),
KUNIT_CASE_SLOW(example_slow_test),
--
2.30.2
