[RFC v1 22/31] kunit: mock: add the concept of spyable functions

From: Brendan Higgins
Date: Tue Oct 16 2018 - 19:54:45 EST


Adds the concept of spying like in Mockito
(http://static.javadoc.io/org.mockito/mockito-core/2.20.0/org/mockito/Mockito.html#spy-T-).
This allows a function declaration to be labled as spyable which allows
the function to be mocked *and* to allow the mock to invoke the original
function definition.

Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
---
include/kunit/mock.h | 123 ++++++++++++++++++++++++++++++++++++++++++-
kunit/common-mocks.c | 36 +++++++++++++
2 files changed, 158 insertions(+), 1 deletion(-)

diff --git a/include/kunit/mock.h b/include/kunit/mock.h
index b58e30ba02ce2..c3615e80d96ee 100644
--- a/include/kunit/mock.h
+++ b/include/kunit/mock.h
@@ -284,6 +284,13 @@ static inline bool is_naggy_mock(struct mock *mock)
DECLARE_MOCK_CLIENT(name, return_type, param_types); \
DECLARE_MOCK_MASTER(name, handle_index, param_types)

+#define DECLARE_SPYABLE(name, return_type, param_types...) \
+ return_type REAL_ID(name)(param_types); \
+ return_type name(param_types); \
+ void *INVOKE_ID(name)(struct test *test, \
+ const void *params[], \
+ int len)
+
#define DECLARE_MOCK_FUNC_CLIENT(name, return_type, param_types...) \
DECLARE_MOCK_CLIENT(name, return_type, param_types)

@@ -465,6 +472,100 @@ static inline bool is_naggy_mock(struct mock *mock)
RETURN(return_type, retval); \
}

+#if IS_ENABLED(CONFIG_KUNIT)
+#define DEFINE_INVOKABLE(name, return_type, RETURN_ASSIGN, param_types...) \
+ void *INVOKE_ID(name)(struct test *test, \
+ const void *params[], \
+ int len) { \
+ return_type *retval; \
+ \
+ TEST_ASSERT_EQ(test, NUM_VA_ARGS(param_types), len); \
+ retval = test_kzalloc(test, \
+ sizeof(*retval), \
+ GFP_KERNEL); \
+ TEST_ASSERT_NOT_ERR_OR_NULL(test, retval); \
+ RETURN_ASSIGN() REAL_ID(name)( \
+ ARRAY_ACCESSORS_FROM_TYPES( \
+ param_types)); \
+ return retval; \
+ }
+#else
+#define DEFINE_INVOKABLE(name, return_type, RETURN_ASSIGN, param_types...)
+#endif
+
+#define DEFINE_SPYABLE_COMMON(name, \
+ return_type, \
+ RETURN_ASSIGN, \
+ param_types...) \
+ return_type REAL_ID(name)(param_types); \
+ return_type name(param_types) __mockable_alias(REAL_ID(name)); \
+ DEFINE_INVOKABLE(name, return_type, RETURN_ASSIGN, param_types);
+
+#define ASSIGN() *retval =
+
+/**
+ * DEFINE_SPYABLE()
+ * @name: name of the function
+ * @return_type: return type of the function
+ * @param_types: parameter types of the function
+ *
+ * Used to define a function which is *redirect-mockable*, which allows the
+ * function to be mocked and refer to the original definition via
+ * INVOKE_REAL().
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ * DEFINE_SPYABLE(i2c_add_adapter,
+ * RETURNS(int), PARAMS(struct i2c_adapter *));
+ * int REAL_ID(i2c_add_adapter)(struct i2c_adapter *adapter)
+ * {
+ * ...
+ * }
+ *
+ * static int aspeed_i2c_test_init(struct test *test)
+ * {
+ * struct mock_param_capturer *adap_capturer;
+ * struct mock_expectation *handle;
+ * struct aspeed_i2c_test *ctx;
+ * int ret;
+ *
+ * ctx = test_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+ * if (!ctx)
+ * return -ENOMEM;
+ * test->priv = ctx;
+ *
+ * handle = TEST_EXPECT_CALL(
+ * i2c_add_adapter(capturer_to_matcher(
+ * adap_capturer)));
+ * handle->action = INVOKE_REAL(test, i2c_add_adapter);
+ * ret = of_fake_probe_platform_by_name(test,
+ * "aspeed-i2c-bus",
+ * "test-i2c-bus");
+ * if (ret < 0)
+ * return ret;
+ *
+ * TEST_ASSERT_PARAM_CAPTURED(test, adap_capturer);
+ * ctx->adap = mock_capturer_get(adap_capturer,
+ * struct i2c_adapter *);
+ *
+ * return 0;
+ * }
+ */
+#define DEFINE_SPYABLE(name, return_type, param_types...) \
+ DEFINE_SPYABLE_COMMON(name, \
+ return_type, \
+ ASSIGN, \
+ param_types)
+
+#define NO_ASSIGN()
+#define DEFINE_SPYABLE_VOID_RETURN(name, param_types) \
+ DEFINE_SPYABLE_COMMON(name, \
+ void, \
+ NO_ASSIGN, \
+ param_types)
+
#define CLASS_MOCK_CLIENT_SOURCE(ctx, handle_index) ctx(arg##handle_index)
#define DEFINE_MOCK_METHOD_CLIENT_COMMON(name, \
handle_index, \
@@ -745,7 +846,7 @@ DECLARE_STRUCT_CLASS_MOCK_INIT(void);
* @...: parameter types of the function
*
* Same as DEFINE_STRUCT_CLASS_MOCK() except can be used to mock any function
- * declared %__mockable or DEFINE_REDIRECT_MOCKABLE()
+ * declared %__mockable or DEFINE_SPYABLE()
*/
#define DEFINE_FUNCTION_MOCK(name, return_type, param_types...) \
DEFINE_FUNCTION_MOCK_INTERNAL(name, return_type, param_types)
@@ -777,6 +878,7 @@ DECLARE_STRUCT_CLASS_MOCK_INIT(void);
* int __mockable example(int arg) { ... }
*/
#define __mockable __weak
+#define __mockable_alias(id) __weak __alias(id)

/**
* __visible_for_testing - Makes a static function visible when testing.
@@ -788,6 +890,7 @@ DECLARE_STRUCT_CLASS_MOCK_INIT(void);
#define __visible_for_testing
#else
#define __mockable
+#define __mockable_alias(id) __alias(id)
#define __visible_for_testing static
#endif

@@ -1069,6 +1172,24 @@ struct mock_param_matcher *test_struct_cmp(
const char *struct_name,
struct mock_struct_matcher_entry *entries);

+struct mock_action *invoke(struct test *test,
+ void *(*invokable)(struct test *,
+ const void *params[],
+ int len));
+
+/**
+ * INVOKE_REAL()
+ * @test: associated test
+ * @func_name: name of the function
+ *
+ * See DEFINE_SPYABLE() for an example.
+ *
+ * Return: &struct mock_action that makes the associated mock method or function
+ * call the original function definition of a redirect-mockable
+ * function.
+ */
+#define INVOKE_REAL(test, func_name) invoke(test, INVOKE_ID(func_name))
+
struct mock_struct_formatter_entry {
size_t member_offset;
struct mock_param_formatter *formatter;
diff --git a/kunit/common-mocks.c b/kunit/common-mocks.c
index 1c52522808cab..ce0159923814d 100644
--- a/kunit/common-mocks.c
+++ b/kunit/common-mocks.c
@@ -386,6 +386,42 @@ DEFINE_RETURN_ACTION_WITH_TYPENAME(longlong, long long);
DEFINE_RETURN_ACTION_WITH_TYPENAME(ulonglong, unsigned long long);
DEFINE_RETURN_ACTION_WITH_TYPENAME(ptr, void *);

+struct mock_invoke_action {
+ struct mock_action action;
+ struct test *test;
+ void *(*invokable)(struct test *test, const void *params[], int len);
+};
+
+static void *do_invoke(struct mock_action *paction,
+ const void *params[],
+ int len)
+{
+ struct mock_invoke_action *action =
+ container_of(paction,
+ struct mock_invoke_action,
+ action);
+
+ return action->invokable(action->test, params, len);
+}
+
+struct mock_action *invoke(struct test *test,
+ void *(*invokable)(struct test *,
+ const void *params[],
+ int len))
+{
+ struct mock_invoke_action *action;
+
+ action = test_kmalloc(test, sizeof(*action), GFP_KERNEL);
+ if (!action)
+ return NULL;
+
+ action->action.do_action = do_invoke;
+ action->test = test;
+ action->invokable = invokable;
+
+ return &action->action;
+}
+
struct mock_param_integer_formatter {
struct mock_param_formatter formatter;
const char *fmt_str;
--
2.19.1.331.ge82ca0e54c-goog