kunit: Introduce KUNIT_EXPECT_MEMEQ and KUNIT_EXPECT_MEMNEQ macros

Currently, in order to compare memory blocks in KUnit, the KUNIT_EXPECT_EQ
or KUNIT_EXPECT_FALSE macros are used in conjunction with the memcmp
function, such as:
    KUNIT_EXPECT_EQ(test, memcmp(foo, bar, size), 0);

Although this usage produces correct results for the test cases, when
the expectation fails, the error message is not very helpful,
indicating only the return of the memcmp function.

Therefore, create a new set of macros KUNIT_EXPECT_MEMEQ and
KUNIT_EXPECT_MEMNEQ that compare memory blocks until a specified size.
In case of expectation failure, those macros print the hex dump of the
memory blocks, making it easier to debug test failures for memory blocks.

That said, the expectation

    KUNIT_EXPECT_EQ(test, memcmp(foo, bar, size), 0);

would translate to the expectation

    KUNIT_EXPECT_MEMEQ(test, foo, bar, size);

Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 87 insertions, 0 deletions

diff --git a/include/kunit/test.h b/include/kunit/test.h
index b1ab6b32216d..cde97dc4eed5 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -658,6 +658,39 @@ do {									       \
 		      ##__VA_ARGS__);					       \
 } while (0)
 
+#define KUNIT_MEM_ASSERTION(test,					       \
+			    assert_type,				       \
+			    left,					       \
+			    op,						       \
+			    right,					       \
+			    size,					       \
+			    fmt,					       \
+			    ...)					       \
+do {									       \
+	const void *__left = (left);					       \
+	const void *__right = (right);					       \
+	const size_t __size = (size);					       \
+	static const struct kunit_binary_assert_text __text = {		       \
+		.operation = #op,					       \
+		.left_text = #left,					       \
+		.right_text = #right,					       \
+	};								       \
+									       \
+	if (likely(memcmp(__left, __right, __size) op 0))		       \
+		break;							       \
+									       \
+	_KUNIT_FAILED(test,						       \
+		      assert_type,					       \
+		      kunit_mem_assert,					       \
+		      kunit_mem_assert_format,				       \
+		      KUNIT_INIT_MEM_ASSERT_STRUCT(&__text,		       \
+						   __left,		       \
+						   __right,		       \
+						   __size),		       \
+		      fmt,						       \
+		      ##__VA_ARGS__);					       \
+} while (0)
+
 #define KUNIT_PTR_NOT_ERR_OR_NULL_MSG_ASSERTION(test,			       \
 						assert_type,		       \
 						ptr,			       \
@@ -929,6 +962,60 @@ do {									       \
 				   ##__VA_ARGS__)
 
 /**
+ * KUNIT_EXPECT_MEMEQ() - Expects that the first @size bytes of @left and @right are equal.
+ * @test: The test context object.
+ * @left: An arbitrary expression that evaluates to the specified size.
+ * @right: An arbitrary expression that evaluates to the specified size.
+ * @size: Number of bytes compared.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, !memcmp((@left), (@right), (@size))). See
+ * KUNIT_EXPECT_TRUE() for more information.
+ *
+ * Although this expectation works for any memory block, it is not recommended
+ * for comparing more structured data, such as structs. This expectation is
+ * recommended for comparing, for example, data arrays.
+ */
+#define KUNIT_EXPECT_MEMEQ(test, left, right, size) \
+	KUNIT_EXPECT_MEMEQ_MSG(test, left, right, size, NULL)
+
+#define KUNIT_EXPECT_MEMEQ_MSG(test, left, right, size, fmt, ...)	       \
+	KUNIT_MEM_ASSERTION(test,					       \
+			    KUNIT_EXPECTATION,				       \
+			    left, ==, right,				       \
+			    size,					       \
+			    fmt,					       \
+			    ##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_MEMNEQ() - Expects that the first @size bytes of @left and @right are not equal.
+ * @test: The test context object.
+ * @left: An arbitrary expression that evaluates to the specified size.
+ * @right: An arbitrary expression that evaluates to the specified size.
+ * @size: Number of bytes compared.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * not equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, memcmp((@left), (@right), (@size))). See
+ * KUNIT_EXPECT_TRUE() for more information.
+ *
+ * Although this expectation works for any memory block, it is not recommended
+ * for comparing more structured data, such as structs. This expectation is
+ * recommended for comparing, for example, data arrays.
+ */
+#define KUNIT_EXPECT_MEMNEQ(test, left, right, size) \
+	KUNIT_EXPECT_MEMNEQ_MSG(test, left, right, size, NULL)
+
+#define KUNIT_EXPECT_MEMNEQ_MSG(test, left, right, size, fmt, ...)	       \
+	KUNIT_MEM_ASSERTION(test,					       \
+			    KUNIT_EXPECTATION,				       \
+			    left, !=, right,				       \
+			    size,					       \
+			    fmt,					       \
+			    ##__VA_ARGS__)
+
+/**
  * KUNIT_EXPECT_NULL() - Expects that @ptr is null.
  * @test: The test context object.
  * @ptr: an arbitrary pointer.