[RFC v2 10/12] kunit: mock: add class mocking support

From: Daniel Latypov
Date: Mon Oct 12 2020 - 18:21:56 EST

From: Brendan Higgins <brendanhiggins@xxxxxxxxxx>

Introduce basic class mocking, the ability to automatically generate a
Linux C-style class implementation whose behavior is controlled by test
cases, which can also set expectations on when and how mocks are called.

Co-developed-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
Signed-off-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
---
include/kunit/mock.h | 433 +++++++++++++++++++++++++++++++++
lib/kunit/Makefile | 5 +-
lib/kunit/kunit-example-test.c | 98 ++++++++
lib/kunit/mock-macro-test.c | 91 +++++++
lib/kunit/mock-test.c | 320 ++++++++++++++++++++++++
5 files changed, 945 insertions(+), 2 deletions(-)
create mode 100644 lib/kunit/mock-test.c

diff --git a/include/kunit/mock.h b/include/kunit/mock.h
index 13fdeb8730b5..9252a0abd295 100644
--- a/include/kunit/mock.h
+++ b/include/kunit/mock.h
@@ -123,6 +123,439 @@ struct mock_expectation *mock_add_matcher(struct mock *mock,
struct mock_param_matcher *matchers[],
int len);

+#define MOCK(name) name##_mock
+
+/**
+ * KUNIT_EXPECT_CALL() - Declares a *call expectation* on a mock function.
+ * @expectation_call: a mocked method or function with parameters replaced with
+ * matchers.
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ * // Class to mock.
+ * struct example {
+ * int (*foo)(struct example *, int);
+ * };
+ *
+ * // Define the mock.
+ * DECLARE_STRUCT_CLASS_MOCK_PREREQS(example);
+ *
+ * DEFINE_STRUCT_CLASS_MOCK(METHOD(foo), CLASS(example),
+ * RETURNS(int),
+ * PARAMS(struct example *, int));
+ *
+ * static int example_init(struct MOCK(example) *mock_example)
+ * {
+ * struct example *example = mock_get_trgt(mock_example);
+ *
+ * example->foo = foo;
+ * return 0;
+ * }
+ *
+ * DEFINE_STRUCT_CLASS_MOCK_INIT(example, example_init);
+ *
+ * static void foo_example_test_success(struct kunit *test)
+ * {
+ * struct MOCK(example) *mock_example;
+ * struct example *example = mock_get_trgt(mock_example);
+ * struct mock_expectation *handle;
+ *
+ * mock_example = CONSTRUCT_MOCK(example, test);
+ *
+ * handle = KUNIT_EXPECT_CALL(foo(mock_get_ctrl(mock_example),
+ * kunit_int_eq(test, 5)));
+ * handle->action = int_return(test, 2);
+ *
+ * KUNIT_EXPECT_EQ(test, 2, example_bar(example, 5));
+ * }
+ *
+ * Return:
+ * A &struct mock_expectation representing the call expectation.
+ * allowing additional conditions and actions to be specified.
+ */
+#define KUNIT_EXPECT_CALL(expectation_call) mock_master_##expectation_call
+
+#define mock_get_ctrl_internal(mock_object) (&(mock_object)->ctrl)
+#define mock_get_ctrl(mock_object) mock_get_ctrl_internal(mock_object)
+
+#define mock_get_trgt_internal(mock_object) (&(mock_object)->trgt)
+#define mock_get_trgt(mock_object) mock_get_trgt_internal(mock_object)
+
+#define mock_get_test(mock_object) (mock_get_ctrl(mock_object)->test)
+
+#define CLASS(struct_name) struct_name
+#define HANDLE_INDEX(index) index
+#define METHOD(method_name) method_name
+#define RETURNS(return_type) return_type
+/* #define PARAMS(...) __VA_ARGS__ included by linux/tracepoint.h */
+
+#define MOCK_INIT_ID(struct_name) struct_name##mock_init
+#define REAL_ID(func_name) __real__##func_name
+#define INVOKE_ID(func_name) __invoke__##func_name
+
+#define DECLARE_MOCK_CLIENT(name, return_type, param_types...) \
+ return_type name(PARAM_LIST_FROM_TYPES(param_types))
+
+#define DECLARE_MOCK_MASTER(name, ctrl_index, param_types...) \
+ struct mock_expectation *mock_master_##name( \
+ MATCHER_PARAM_LIST_FROM_TYPES(ctrl_index, \
+ param_types))
+
+#define DECLARE_MOCK_COMMON(name, handle_index, return_type, param_types...) \
+ DECLARE_MOCK_CLIENT(name, return_type, param_types); \
+ DECLARE_MOCK_MASTER(name, handle_index, param_types)
+
+#define DECLARE_STRUCT_CLASS_MOCK_STRUCT(struct_name) \
+ struct MOCK(struct_name) { \
+ struct mock ctrl; \
+ struct struct_name trgt; \
+ }
+
+#define DECLARE_STRUCT_CLASS_MOCK_CONVERTER(struct_name) \
+ static inline struct mock *from_##struct_name##_to_mock( \
+ const struct struct_name *trgt) \
+ { \
+ return mock_get_ctrl( \
+ container_of(trgt, \
+ struct MOCK(struct_name), \
+ trgt)); \
+ }
+
+/**
+ * DECLARE_STRUCT_CLASS_MOCK_PREREQS() - Create a mock child class
+ * @struct_name: name of the class/struct to be mocked
+ *
+ * Creates a mock child class of ``struct_name`` named
+ * ``struct MOCK(struct_name)`` along with supporting internally used methods.
+ *
+ * See KUNIT_EXPECT_CALL() for example usages.
+ */
+#define DECLARE_STRUCT_CLASS_MOCK_PREREQS(struct_name) \
+ DECLARE_STRUCT_CLASS_MOCK_STRUCT(struct_name); \
+ DECLARE_STRUCT_CLASS_MOCK_CONVERTER(struct_name)
+
+#define DECLARE_STRUCT_CLASS_MOCK_HANDLE_INDEX_INTERNAL(name, \
+ struct_name, \
+ handle_index, \
+ return_type, \
+ param_types...) \
+ DECLARE_MOCK_COMMON(name, \
+ handle_index, \
+ return_type, \
+ param_types)
+
+#define DECLARE_STRUCT_CLASS_MOCK_HANDLE_INDEX(name, \
+ struct_name, \
+ handle_index, \
+ return_type, \
+ param_types...) \
+ DECLARE_STRUCT_CLASS_MOCK_HANDLE_INDEX_INTERNAL(name, \
+ struct_name, \
+ handle_index, \
+ return_type, \
+ param_types)
+
+/**
+ * DECLARE_STRUCT_CLASS_MOCK()
+ * @name: method name
+ * @struct_name: name of the class/struct
+ * @return_type: return type of the method
+ * @param_types: parameters of the method
+ *
+ * Same as DEFINE_STRUCT_CLASS_MOCK(), but only makes header compatible
+ * declarations.
+ */
+#define DECLARE_STRUCT_CLASS_MOCK(name, \
+ struct_name, \
+ return_type, \
+ param_types...) \
+ DECLARE_STRUCT_CLASS_MOCK_HANDLE_INDEX(name, \
+ struct_name, \
+ 0, \
+ return_type, \
+ param_types)
+
+/**
+ * DECLARE_STRUCT_CLASS_MOCK_VOID_RETURN()
+ * @name: method name
+ * @struct_name: name of the class/struct
+ * @param_types: parameters of the method
+ *
+ * Same as DEFINE_STRUCT_CLASS_MOCK_VOID_RETURN(), but only makes header
+ * compatible declarations.
+ */
+#define DECLARE_STRUCT_CLASS_MOCK_VOID_RETURN(name, \
+ struct_name, \
+ param_types...) \
+ DECLARE_STRUCT_CLASS_MOCK_HANDLE_INDEX(name, \
+ struct_name, \
+ 0, \
+ void, \
+ param_types)
+
+/**
+ * DECLARE_STRUCT_CLASS_MOCK_INIT()
+ * @struct_name: name of the class/struct
+ *
+ * Same as DEFINE_STRUCT_CLASS_MOCK_INIT(), but only makes header compatible
+ * declarations.
+ */
+#define DECLARE_STRUCT_CLASS_MOCK_INIT(struct_name) \
+ struct MOCK(struct_name) *MOCK_INIT_ID(struct_name)( \
+ struct kunit *test)
+
+/**
+ * CONSTRUCT_MOCK()
+ * @struct_name: name of the class
+ * @test: associated test
+ *
+ * Constructs and allocates a test managed ``struct MOCK(struct_name)`` given
+ * the name of the class for which the mock is defined and a test object.
+ *
+ * See KUNIT_EXPECT_CALL() for example usage.
+ */
+#define CONSTRUCT_MOCK(struct_name, test) MOCK_INIT_ID(struct_name)(test)
+
+#define DEFINE_MOCK_CLIENT_COMMON(name, \
+ handle_index, \
+ MOCK_SOURCE, \
+ mock_source_ctx, \
+ return_type, \
+ RETURN, \
+ param_types...) \
+ return_type name(PARAM_LIST_FROM_TYPES(param_types)) \
+ { \
+ struct mock *mock = MOCK_SOURCE(mock_source_ctx, \
+ handle_index); \
+ static const char * const param_type_names[] = { \
+ TYPE_NAMES_FROM_TYPES(handle_index, \
+ param_types) \
+ }; \
+ const void *params[] = { \
+ PTR_TO_ARG_FROM_TYPES(handle_index, \
+ param_types) \
+ }; \
+ const void *retval; \
+ \
+ retval = mock->do_expect(mock, \
+ #name, \
+ name, \
+ param_type_names, \
+ params, \
+ ARRAY_SIZE(params)); \
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(mock->test, retval); \
+ if (!retval) { \
+ kunit_info(mock->test, \
+ "no action installed for "#name"\n");\
+ BUG(); \
+ } \
+ RETURN(return_type, retval); \
+ }
+
+#define CLASS_MOCK_CLIENT_SOURCE(ctx, handle_index) ctx(arg##handle_index)
+#define DEFINE_MOCK_METHOD_CLIENT_COMMON(name, \
+ handle_index, \
+ mock_converter, \
+ return_type, \
+ RETURN, \
+ param_types...) \
+ DEFINE_MOCK_CLIENT_COMMON(name, \
+ handle_index, \
+ CLASS_MOCK_CLIENT_SOURCE, \
+ mock_converter, \
+ return_type, \
+ RETURN, \
+ param_types)
+
+#define CAST_AND_RETURN(return_type, retval) return *((return_type *) retval)
+#define NO_RETURN(return_type, retval)
+
+#define DEFINE_MOCK_METHOD_CLIENT(name, \
+ handle_index, \
+ mock_converter, \
+ return_type, \
+ param_types...) \
+ DEFINE_MOCK_METHOD_CLIENT_COMMON(name, \
+ handle_index, \
+ mock_converter, \
+ return_type, \
+ CAST_AND_RETURN, \
+ param_types)
+
+#define DEFINE_MOCK_METHOD_CLIENT_VOID_RETURN(name, \
+ handle_index, \
+ mock_converter, \
+ param_types...) \
+ DEFINE_MOCK_METHOD_CLIENT_COMMON(name, \
+ handle_index, \
+ mock_converter, \
+ void, \
+ NO_RETURN, \
+ param_types)
+
+#define DEFINE_MOCK_MASTER_COMMON_INTERNAL(name, \
+ ctrl_index, \
+ MOCK_SOURCE, \
+ param_types...) \
+ struct mock_expectation *mock_master_##name( \
+ MATCHER_PARAM_LIST_FROM_TYPES(ctrl_index, \
+ param_types)) \
+ { \
+ struct mock_param_matcher *matchers[] = { \
+ ARG_NAMES_FROM_TYPES(ctrl_index, param_types) \
+ }; \
+ \
+ return mock_add_matcher(MOCK_SOURCE(ctrl_index), \
+ #name, \
+ (const void *) name, \
+ matchers, \
+ ARRAY_SIZE(matchers)); \
+ }
+#define DEFINE_MOCK_MASTER_COMMON(name, \
+ ctrl_index, \
+ MOCK_SOURCE, \
+ param_types...) \
+ DEFINE_MOCK_MASTER_COMMON_INTERNAL(name, \
+ ctrl_index, \
+ MOCK_SOURCE, \
+ param_types)
+
+#define CLASS_MOCK_MASTER_SOURCE(ctrl_index) arg##ctrl_index
+#define DEFINE_MOCK_METHOD_MASTER(name, ctrl_index, param_types...) \
+ DEFINE_MOCK_MASTER_COMMON(name, \
+ ctrl_index, \
+ CLASS_MOCK_MASTER_SOURCE, \
+ param_types)
+
+#define DEFINE_MOCK_COMMON(name, \
+ handle_index, \
+ mock_converter, \
+ return_type, \
+ param_types...) \
+ DEFINE_MOCK_METHOD_CLIENT(name, \
+ handle_index, \
+ mock_converter, \
+ return_type, \
+ param_types); \
+ DEFINE_MOCK_METHOD_MASTER(name, handle_index, param_types)
+
+#define DEFINE_MOCK_COMMON_VOID_RETURN(name, \
+ handle_index, \
+ mock_converter, \
+ param_types...) \
+ DEFINE_MOCK_METHOD_CLIENT_VOID_RETURN(name, \
+ handle_index, \
+ mock_converter, \
+ param_types); \
+ DEFINE_MOCK_METHOD_MASTER(name, handle_index, param_types)
+
+#define DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX_INTERNAL(name, \
+ struct_name, \
+ handle_index, \
+ return_type, \
+ param_types...) \
+ DEFINE_MOCK_COMMON(name, \
+ handle_index, \
+ from_##struct_name##_to_mock, \
+ return_type, param_types)
+#define DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX(name, \
+ struct_name, \
+ handle_index, \
+ return_type, \
+ param_types...) \
+ DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX_INTERNAL(name, \
+ struct_name, \
+ handle_index, \
+ return_type, \
+ param_types)
+
+#define DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX_VOID_RETURN_INTERNAL( \
+ name, \
+ struct_name, \
+ handle_index, \
+ param_types...) \
+ DEFINE_MOCK_COMMON_VOID_RETURN(name, \
+ handle_index, \
+ from_##struct_name##_to_mock, \
+ param_types)
+#define DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX_VOID_RETURN(name, \
+ struct_name, \
+ handle_index, \
+ param_types...) \
+ DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX_VOID_RETURN_INTERNAL( \
+ name, \
+ struct_name, \
+ handle_index, \
+ param_types)
+
+/**
+ * DEFINE_STRUCT_CLASS_MOCK()
+ * @name: name of the method
+ * @struct_name: name of the class of which the method belongs
+ * @return_type: return type of the method to be created. **Must not be void.**
+ * @param_types: parameters to method to be created.
+ *
+ * See KUNIT_EXPECT_CALL() for example usage.
+ */
+#define DEFINE_STRUCT_CLASS_MOCK(name, \
+ struct_name, \
+ return_type, \
+ param_types...) \
+ DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX(name, \
+ struct_name, \
+ 0, \
+ return_type, \
+ param_types)
+
+/**
+ * DEFINE_STRUCT_CLASS_MOCK_VOID_RETURN()
+ * @name: name of the method
+ * @struct_name: name of the class of which the method belongs
+ * @param_types: parameters to method to be created.
+ *
+ * Same as DEFINE_STRUCT_CLASS_MOCK() except the method has a ``void`` return
+ * type.
+ */
+#define DEFINE_STRUCT_CLASS_MOCK_VOID_RETURN(name, struct_name, param_types...)\
+ DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX_VOID_RETURN(name, \
+ struct_name, \
+ 0, \
+ param_types)
+
+/**
+ * DEFINE_STRUCT_CLASS_MOCK_INIT()
+ * @struct_name: name of the class
+ * @init_func: a function of type ``int (*)(struct kunit *, struct MOCK(struct_name) *)``.
+ * The function is passed a pointer to an allocated, *but not
+ * initialized*, ``struct MOCK(struct_name)``. The job of this user
+ * provided function is to perform remaining initialization. Usually
+ * this entails assigning mock methods to the function pointers in
+ * the parent struct.
+ *
+ * See KUNIT_EXPECT_CALL() for example usage.
+ */
+#define DEFINE_STRUCT_CLASS_MOCK_INIT(struct_name, init_func) \
+ struct MOCK(struct_name) *MOCK_INIT_ID(struct_name)( \
+ struct kunit *test) \
+ { \
+ struct MOCK(struct_name) *mock_obj; \
+ \
+ mock_obj = kunit_kzalloc(test, \
+ sizeof(*mock_obj), \
+ GFP_KERNEL); \
+ if (!mock_obj) \
+ return NULL; \
+ \
+ mock_init_ctrl(test, mock_get_ctrl(mock_obj)); \
+ \
+ if (init_func(test, mock_obj)) \
+ return NULL; \
+ \
+ return mock_obj; \
+ }
+
#define CONVERT_TO_ACTUAL_TYPE(type, ptr) (*((type *) ptr))

/**
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index a7a3c5e0a8bf..649e1c1f0d00 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -13,11 +13,12 @@ kunit-objs += debugfs.o
endif

obj-$(CONFIG_KUNIT_TEST) += kunit-test.o \
- mock-macro-test.o
+ mock-macro-test.o \
+ mock-test.o

# string-stream-test compiles built-in only.
ifeq ($(CONFIG_KUNIT_TEST),y)
obj-$(CONFIG_KUNIT_TEST) += string-stream-test.o
endif

-obj-$(CONFIG_KUNIT_EXAMPLE_TEST) += kunit-example-test.o
+obj-$(CONFIG_KUNIT_EXAMPLE_TEST) += kunit-example-test.o
diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
index be1164ecc476..d6fff5a961ce 100644
--- a/lib/kunit/kunit-example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -7,6 +7,7 @@
*/

#include <kunit/test.h>
+#include <kunit/mock.h>

/*
* This is the most fundamental element of KUnit, the test case. A test case
@@ -29,6 +30,92 @@ static void example_simple_test(struct kunit *test)
KUNIT_EXPECT_EQ(test, 1 + 1, 2);
}

+struct example_ops;
+
+struct example {
+ struct example_ops *ops;
+};
+
+/*
+ * A lot of times, we embed "ops structs", which acts an abstraction over
+ * hardware, a file system implementation, or some other subsystem that you
+ * want to reason about in a generic way.
+ */
+struct example_ops {
+ int (*foo)(struct example *example, int num);
+};
+
+static int example_bar(struct example *example, int num)
+{
+ return example->ops->foo(example, num);
+}
+
+/*
+ * KUnit allows such a class to be "mocked out" with the following:
+ */
+
+/*
+ * This macro creates a mock subclass of the specified class.
+ */
+DECLARE_STRUCT_CLASS_MOCK_PREREQS(example);
+
+/*
+ * This macro creates a mock implementation of the specified method of the
+ * specified class.
+ */
+DEFINE_STRUCT_CLASS_MOCK(METHOD(foo), CLASS(example),
+ RETURNS(int),
+ PARAMS(struct example *, int));
+
+/*
+ * This tells KUnit how to initialize the parts of the mock that come from the
+ * parent. In this example, all we have to do is populate the member functions
+ * of the parent class with the mock versions we defined.
+ */
+static int example_init(struct kunit *test, struct MOCK(example) *mock_example)
+{
+ /* This is how you get a pointer to the parent class of a mock. */
+ struct example *example = mock_get_trgt(mock_example);
+
+ /*
+ * Here we create an ops struct containing our mock method instead.
+ */
+ example->ops = kunit_kzalloc(test, sizeof(*example->ops), GFP_KERNEL);
+ example->ops->foo = foo;
+
+ return 0;
+}
+
+/*
+ * This registers our parent init function above, allowing KUnit to create a
+ * constructor for the mock.
+ */
+DEFINE_STRUCT_CLASS_MOCK_INIT(example, example_init);
+
+/*
+ * This is a test case where we use our mock.
+ */
+static void example_mock_test(struct kunit *test)
+{
+ struct MOCK(example) *mock_example = test->priv;
+ struct example *example = mock_get_trgt(mock_example);
+ struct mock_expectation *handle;
+
+ /*
+ * Here we make an expectation that our mock method will be called with
+ * a parameter equal to 5 passed in.
+ */
+ handle = KUNIT_EXPECT_CALL(foo(mock_get_ctrl(mock_example),
+ kunit_int_eq(test, 5)));
+ /*
+ * We specify that when our mock is called in this way, we want it to
+ * return 2.
+ */
+ handle->action = kunit_int_return(test, 2);
+
+ KUNIT_EXPECT_EQ(test, 2, example_bar(example, 5));
+}
+
/*
* This is run once before each test case, see the comment on
* example_test_suite for more information.
@@ -37,6 +124,16 @@ static int example_test_init(struct kunit *test)
{
kunit_info(test, "initializing\n");

+ /*
+ * Here we construct the mock and store it in test's `priv` field; this
+ * field is for KUnit users. You can put whatever you want here, but
+ * most often it is a place that the init function can put stuff to be
+ * used by test cases.
+ */
+ test->priv = CONSTRUCT_MOCK(example, test);
+ if (!test->priv)
+ return -EINVAL;
+
return 0;
}

@@ -52,6 +149,7 @@ static struct kunit_case example_test_cases[] = {
* test suite.
*/
KUNIT_CASE(example_simple_test),
+ KUNIT_CASE(example_mock_test),
{}
};

diff --git a/lib/kunit/mock-macro-test.c b/lib/kunit/mock-macro-test.c
index 6c3dc2193edb..d196dbee2407 100644
--- a/lib/kunit/mock-macro-test.c
+++ b/lib/kunit/mock-macro-test.c
@@ -8,6 +8,55 @@

#include <kunit/test.h>
#include <kunit/params.h>
+#include <kunit/mock.h>
+
+struct mock_macro_dummy_struct {
+ int (*one_param)(struct mock_macro_dummy_struct *test_struct);
+ int (*two_param)(struct mock_macro_dummy_struct *test_struct, int num);
+ int (*non_first_slot_param)(
+ int num,
+ struct mock_macro_dummy_struct *test_struct);
+ void *(*void_ptr_return)(struct mock_macro_dummy_struct *test_struct);
+};
+
+DECLARE_STRUCT_CLASS_MOCK_PREREQS(mock_macro_dummy_struct);
+
+DEFINE_STRUCT_CLASS_MOCK(METHOD(one_param), CLASS(mock_macro_dummy_struct),
+ RETURNS(int),
+ PARAMS(struct mock_macro_dummy_struct *));
+
+DEFINE_STRUCT_CLASS_MOCK(METHOD(two_param), CLASS(mock_macro_dummy_struct),
+ RETURNS(int),
+ PARAMS(struct mock_macro_dummy_struct *, int));
+
+DEFINE_STRUCT_CLASS_MOCK_HANDLE_INDEX(METHOD(non_first_slot_param),
+ CLASS(mock_macro_dummy_struct), HANDLE_INDEX(1),
+ RETURNS(int),
+ PARAMS(int, struct mock_macro_dummy_struct *));
+
+DEFINE_STRUCT_CLASS_MOCK(METHOD(void_ptr_return),
+ CLASS(mock_macro_dummy_struct),
+ RETURNS(void *),
+ PARAMS(struct mock_macro_dummy_struct *));
+
+static int mock_macro_dummy_struct_init(
+ struct MOCK(mock_macro_dummy_struct) *mock_test_struct)
+{
+ struct mock_macro_dummy_struct *test_struct =
+ mock_get_trgt(mock_test_struct);
+
+ test_struct->one_param = one_param;
+ test_struct->two_param = two_param;
+ test_struct->non_first_slot_param = non_first_slot_param;
+ return 0;
+}
+
+DEFINE_STRUCT_CLASS_MOCK_INIT(mock_macro_dummy_struct,
+ mock_macro_dummy_struct_init);
+
+struct mock_macro_context {
+ struct MOCK(mock_macro_dummy_struct) *mock_test_struct;
+};

#define TO_STR_INTERNAL(...) #__VA_ARGS__
#define TO_STR(...) TO_STR_INTERNAL(__VA_ARGS__)
@@ -132,6 +181,46 @@ static void mock_macro_arg_names_from_types(struct kunit *test)
type15)));
}

+static void mock_macro_test_generated_method_code_works(struct kunit *test)
+{
+ struct mock_macro_context *ctx = test->priv;
+ struct MOCK(mock_macro_dummy_struct) *mock_test_struct =
+ ctx->mock_test_struct;
+ struct mock_macro_dummy_struct *test_struct =
+ mock_get_trgt(mock_test_struct);
+ struct mock_expectation *handle;
+
+ handle = KUNIT_EXPECT_CALL(one_param(mock_get_ctrl(mock_test_struct)));
+ handle->action = kunit_int_return(test, 0);
+ handle = KUNIT_EXPECT_CALL(two_param(mock_get_ctrl(mock_test_struct),
+ kunit_int_eq(test, 5)));
+ handle->action = kunit_int_return(test, 1);
+ handle = KUNIT_EXPECT_CALL(non_first_slot_param(
+ kunit_int_eq(test, 5),
+ mock_get_ctrl(mock_test_struct)));
+ handle->action = kunit_int_return(test, 1);
+
+ test_struct->one_param(test_struct);
+ test_struct->two_param(test_struct, 5);
+ test_struct->non_first_slot_param(5, test_struct);
+}
+
+static int mock_macro_test_init(struct kunit *test)
+{
+ struct mock_macro_context *ctx;
+
+ ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ test->priv = ctx;
+
+ ctx->mock_test_struct = CONSTRUCT_MOCK(mock_macro_dummy_struct, test);
+ if (!ctx->mock_test_struct)
+ return -EINVAL;
+
+ return 0;
+}
+
static struct kunit_case mock_macro_test_cases[] = {
KUNIT_CASE(mock_macro_is_equal),
KUNIT_CASE(mock_macro_if),
@@ -140,11 +229,13 @@ static struct kunit_case mock_macro_test_cases[] = {
KUNIT_CASE(mock_macro_for_each_param),
KUNIT_CASE(mock_macro_param_list_from_types_basic),
KUNIT_CASE(mock_macro_arg_names_from_types),
+ KUNIT_CASE(mock_macro_test_generated_method_code_works),
{}
};

static struct kunit_suite mock_macro_test_suite = {
.name = "mock-macro-test",
+ .init = mock_macro_test_init,
.test_cases = mock_macro_test_cases,
};
kunit_test_suite(mock_macro_test_suite);
diff --git a/lib/kunit/mock-test.c b/lib/kunit/mock-test.c
new file mode 100644
index 000000000000..8a0fa33d087c
--- /dev/null
+++ b/lib/kunit/mock-test.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for mock.h.
+ *
+ * Copyright (C) 2020, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
+ */
+
+#include <kunit/test.h>
+#include <kunit/mock.h>
+
+// A simple class for unit-testing/example purposes.
+struct adder {
+ int (*add)(struct adder *adder, int x, int y);
+};
+
+static int real_add(struct adder *adder, int x, int y)
+{
+ return x + y;
+}
+
+static void adder_real_init(struct adder *adder)
+{
+ adder->add = real_add;
+}
+
+DECLARE_STRUCT_CLASS_MOCK_PREREQS(adder);
+DEFINE_STRUCT_CLASS_MOCK(METHOD(mock_add), CLASS(adder), RETURNS(int),
+ PARAMS(struct adder*, int, int));
+DECLARE_STRUCT_CLASS_MOCK_INIT(adder);
+
+// This would normally live in the .c file.
+static int adder_mock_init(struct MOCK(adder) *mock_adder)
+{
+ struct adder *real = mock_get_trgt(mock_adder);
+
+ adder_real_init(real);
+
+ real->add = mock_add;
+ mock_set_default_action(mock_get_ctrl(mock_adder),
+ "mock_add",
+ mock_add,
+ kunit_int_return(mock_get_test(mock_adder), 0));
+ return 0;
+}
+DEFINE_STRUCT_CLASS_MOCK_INIT(adder, adder_mock_init);
+
+
+/*
+ * Note: we create a new `failing_test` so we can validate that failed mock
+ * expectations mark tests as failed.
+ * Marking the real `test` as failed is obviously problematic.
+ *
+ * See mock_test_failed_expect_call_fails_test for an example.
+ */
+struct mock_test_context {
+ struct kunit *failing_test;
+ struct mock *mock;
+};
+
+static void mock_test_do_expect_basic(struct kunit *test)
+{
+ struct mock_test_context *ctx = test->priv;
+ struct mock *mock = ctx->mock;
+ int param0 = 5, param1 = -4;
+ static const char * const two_param_types[] = {"int", "int"};
+ const void *two_params[] = {&param0, &param1};
+ struct mock_param_matcher *matchers_any_two[] = {
+ kunit_any(test), kunit_any(test)
+ };
+ struct mock_expectation *expectation;
+ const void *ret;
+
+ expectation = mock_add_matcher(mock,
+ "",
+ NULL,
+ matchers_any_two,
+ ARRAY_SIZE(matchers_any_two));
+ expectation->action = kunit_int_return(test, 5);
+ KUNIT_EXPECT_EQ(test, 0, expectation->times_called);
+
+ ret = mock->do_expect(mock,
+ "",
+ NULL,
+ two_param_types,
+ two_params,
+ ARRAY_SIZE(two_params));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+ KUNIT_EXPECT_EQ(test, 5, *((int *) ret));
+ KUNIT_EXPECT_EQ(test, 1, expectation->times_called);
+}
+
+static void mock_test_ptr_eq(struct kunit *test)
+{
+ struct mock_test_context *ctx = test->priv;
+ struct kunit *failing_test = ctx->failing_test;
+ struct mock *mock = ctx->mock;
+ void *param0 = ctx, *param1 = failing_test;
+ static const char * const two_param_types[] = {"void *", "void *"};
+ const void *two_params[] = {&param0, &param1};
+ struct mock_param_matcher *matchers_two_ptrs[] = {
+ kunit_ptr_eq(test, param0), kunit_ptr_eq(test, param1)
+ };
+ struct mock_expectation *expectation;
+ const void *ret;
+
+ expectation = mock_add_matcher(mock,
+ "",
+ NULL,
+ matchers_two_ptrs,
+ ARRAY_SIZE(matchers_two_ptrs));
+ expectation->action = kunit_int_return(test, 0);
+ KUNIT_EXPECT_EQ(test, 0, expectation->times_called);
+
+ ret = mock->do_expect(mock,
+ "",
+ NULL,
+ two_param_types,
+ two_params,
+ ARRAY_SIZE(two_params));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+ KUNIT_EXPECT_EQ(test, 1, expectation->times_called);
+}
+
+static void mock_test_ptr_eq_not_equal(struct kunit *test)
+{
+ struct mock_test_context *ctx = test->priv;
+ struct kunit *failing_test = ctx->failing_test;
+ struct mock *mock = ctx->mock;
+
+ /* Pick some two pointers, but pass in different values. */
+ void *param0 = test, *param1 = failing_test;
+ static const char * const two_param_types[] = {"void *", "void *"};
+ const void *two_params[] = {&param0, &param1};
+ struct mock_param_matcher *matchers_two_ptrs[] = {
+ kunit_ptr_eq(failing_test, param0),
+ kunit_ptr_eq(failing_test, param1 - 1)
+ };
+ struct mock_expectation *expectation;
+ const void *ret;
+
+ expectation = mock_add_matcher(mock,
+ "",
+ NULL,
+ matchers_two_ptrs,
+ ARRAY_SIZE(matchers_two_ptrs));
+ expectation->action = kunit_int_return(failing_test, 0);
+ KUNIT_EXPECT_EQ(test, 0, expectation->times_called);
+
+ ret = mock->do_expect(mock,
+ "",
+ NULL,
+ two_param_types,
+ two_params,
+ ARRAY_SIZE(two_params));
+ KUNIT_EXPECT_FALSE(test, ret);
+ KUNIT_EXPECT_EQ(test, 0, expectation->times_called);
+
+ KUNIT_EXPECT_FALSE(test, failing_test->success);
+}
+
+/*
+ * In order for us to be able to rely on KUNIT_EXPECT_CALL to validate other
+ * behavior, we need to test that unsatisfied KUNIT_EXPECT_CALL causes a test
+ * failure.
+ *
+ * In order to understand what this test is testing we must first understand how
+ * KUNIT_EXPECT_CALL() works conceptually. In theory, a test specifies that it
+ * expects some function to be called some number of times (can be zero), with
+ * some particular arguments. Hence, KUNIT_EXPECT_CALL() must do two things:
+ *
+ * 1) Determine whether a function call matches the expectation.
+ *
+ * 2) Fail if there are too many or too few matches.
+ */
+static void mock_test_failed_expect_call_fails_test(struct kunit *test)
+{
+ /*
+ * We do not want to fail the real `test` object used to run this test.
+ * So we use a separate `failing_test` for KUNIT_EXPECT_CALL().
+ */
+ struct mock_test_context *ctx = test->priv;
+ struct kunit *failing_test = ctx->failing_test;
+ struct mock *mock = ctx->mock;
+
+ /*
+ * Put an expectation on mock, which we won't satisify.
+ *
+ * NOTE: it does not actually matter what function we expect here.
+ * `mock` does not represent an actual mock on anything; we just need to
+ * create some expectation, that we won't satisfy.
+ */
+ KUNIT_EXPECT_CALL(mock_add(mock,
+ kunit_any(failing_test),
+ kunit_any(failing_test)));
+
+ /*
+ * Validate the unsatisfied expectation that we just created. This
+ * should cause `failing_test` to fail.
+ */
+ mock_validate_expectations(mock);
+
+ /* Verify that `failing_test` has actually failed. */
+ KUNIT_EXPECT_FALSE(test, failing_test->success);
+}
+
+static void mock_test_do_expect_default_return(struct kunit *test)
+{
+ struct mock_test_context *ctx = test->priv;
+ struct mock *mock = ctx->mock;
+ int param0 = 5, param1 = -5;
+ static const char * const two_param_types[] = {"int", "int"};
+ const void *two_params[] = {&param0, &param1};
+ struct mock_param_matcher *matchers[] = {
+ kunit_int_eq(test, 5),
+ kunit_int_eq(test, -4)
+ };
+ struct mock_expectation *expectation;
+ const void *ret;
+
+ expectation = mock_add_matcher(mock,
+ "add",
+ mock_add,
+ matchers,
+ ARRAY_SIZE(matchers));
+ expectation->action = kunit_int_return(test, 5);
+ KUNIT_EXPECT_EQ(test, 0, expectation->times_called);
+
+ KUNIT_EXPECT_FALSE(test,
+ mock_set_default_action(mock,
+ "add",
+ mock_add,
+ kunit_int_return(test, -4)));
+
+ ret = mock->do_expect(mock,
+ "add",
+ mock_add,
+ two_param_types,
+ two_params,
+ ARRAY_SIZE(two_params));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+ KUNIT_EXPECT_EQ(test, -4, *((int *) ret));
+ KUNIT_EXPECT_EQ(test, 0, expectation->times_called);
+}
+
+static void mock_test_mock_validate_expectations(struct kunit *test)
+{
+ struct mock_test_context *ctx = test->priv;
+ struct kunit *failing_test = ctx->failing_test;
+ struct mock *mock = ctx->mock;
+
+ struct mock_param_matcher *matchers[] = {
+ kunit_int_eq(failing_test, 5),
+ kunit_int_eq(failing_test, -4)
+ };
+ struct mock_expectation *expectation;
+
+
+ expectation = mock_add_matcher(mock,
+ "add",
+ mock_add,
+ matchers,
+ ARRAY_SIZE(matchers));
+ expectation->times_called = 0;
+ expectation->min_calls_expected = 1;
+ expectation->max_calls_expected = 1;
+
+ mock_validate_expectations(mock);
+
+ KUNIT_EXPECT_FALSE(test, failing_test->success);
+}
+
+static int mock_test_init(struct kunit *test)
+{
+ struct mock_test_context *ctx;
+
+ ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ test->priv = ctx;
+
+ ctx->failing_test = kunit_kzalloc(test, sizeof(*ctx->failing_test),
+ GFP_KERNEL);
+ if (!ctx->failing_test)
+ return -EINVAL;
+ kunit_init_test(ctx->failing_test, NULL, NULL);
+
+ ctx->mock = kunit_kzalloc(test, sizeof(*ctx->mock), GFP_KERNEL);
+ if (!ctx->mock)
+ return -ENOMEM;
+ mock_init_ctrl(ctx->failing_test, ctx->mock);
+
+ return 0;
+}
+
+static void mock_test_exit(struct kunit *test)
+{
+ struct mock_test_context *ctx = test->priv;
+
+ kunit_cleanup(ctx->failing_test);
+}
+
+static struct kunit_case mock_test_cases[] = {
+ KUNIT_CASE(mock_test_do_expect_basic),
+ KUNIT_CASE(mock_test_ptr_eq),
+ KUNIT_CASE(mock_test_ptr_eq_not_equal),
+ KUNIT_CASE(mock_test_failed_expect_call_fails_test),
+ KUNIT_CASE(mock_test_do_expect_default_return),
+ KUNIT_CASE(mock_test_mock_validate_expectations),
+ {}
+};
+
+static struct kunit_suite mock_test_suite = {
+ .name = "mock-test",
+ .init = mock_test_init,
+ .exit = mock_test_exit,
+ .test_cases = mock_test_cases,
+};
+
+kunit_test_suite(mock_test_suite);
--
2.28.0.1011.ga647a8990f-goog