[PATCH v12 04/18] kunit: test: add assertion printing library

[Brendan Higgins <brendanhiggins@google.com>]

Add `struct kunit_assert` and friends which provide a structured way to
capture data from an expectation or an assertion (introduced later in
the series) so that it may be printed out in the event of a failure.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
---
 include/kunit/assert.h | 183 +++++++++++++++++++++++++++++++++++++++++
 kunit/Makefile         |   3 +-
 kunit/assert.c         | 141 +++++++++++++++++++++++++++++++
 3 files changed, 326 insertions(+), 1 deletion(-)
 create mode 100644 include/kunit/assert.h
 create mode 100644 kunit/assert.c

diff --git a/include/kunit/assert.h b/include/kunit/assert.h
new file mode 100644
index 0000000000000..55f1b88b0cb4d
--- /dev/null
+++ b/include/kunit/assert.h
@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Assertion and expectation serialization API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_ASSERT_H
+#define _KUNIT_ASSERT_H
+
+#include <linux/err.h>
+#include <kunit/string-stream.h>
+
+struct kunit;
+
+enum kunit_assert_type {
+	KUNIT_ASSERTION,
+	KUNIT_EXPECTATION,
+};
+
+struct kunit_assert {
+	struct kunit *test;
+	enum kunit_assert_type type;
+	int line;
+	const char *file;
+	struct va_format message;
+	void (*format)(const struct kunit_assert *assert,
+		       struct string_stream *stream);
+};
+
+#define KUNIT_INIT_VA_FMT_NULL { .fmt = NULL, .va = NULL }
+
+#define KUNIT_INIT_ASSERT_STRUCT(kunit, assert_type, fmt) {		       \
+	.test = kunit,							       \
+	.type = assert_type,						       \
+	.file = __FILE__,						       \
+	.line = __LINE__,						       \
+	.message = KUNIT_INIT_VA_FMT_NULL,				       \
+	.format = fmt							       \
+}
+
+void kunit_base_assert_format(const struct kunit_assert *assert,
+			      struct string_stream *stream);
+
+void kunit_assert_print_msg(const struct kunit_assert *assert,
+			    struct string_stream *stream);
+
+struct kunit_fail_assert {
+	struct kunit_assert assert;
+};
+
+void kunit_fail_assert_format(const struct kunit_assert *assert,
+			      struct string_stream *stream);
+
+#define KUNIT_INIT_FAIL_ASSERT_STRUCT(test, type) {			       \
+		.assert = KUNIT_INIT_ASSERT_STRUCT(test,		       \
+						   type,		       \
+						   kunit_fail_assert_format)   \
+}
+
+struct kunit_unary_assert {
+	struct kunit_assert assert;
+	const char *condition;
+	bool expected_true;
+};
+
+void kunit_unary_assert_format(const struct kunit_assert *assert,
+			       struct string_stream *stream);
+
+#define KUNIT_INIT_UNARY_ASSERT_STRUCT(test, type, cond, expect_true) {	       \
+	.assert = KUNIT_INIT_ASSERT_STRUCT(test,			       \
+					   type,			       \
+					   kunit_unary_assert_format),	       \
+	.condition = cond,						       \
+	.expected_true = expect_true					       \
+}
+
+struct kunit_ptr_not_err_assert {
+	struct kunit_assert assert;
+	const char *text;
+	const void *value;
+};
+
+void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
+				     struct string_stream *stream);
+
+#define KUNIT_INIT_PTR_NOT_ERR_STRUCT(test, type, txt, val) {		       \
+	.assert = KUNIT_INIT_ASSERT_STRUCT(test,			       \
+					   type,			       \
+					   kunit_ptr_not_err_assert_format),   \
+	.text = txt,							       \
+	.value = val							       \
+}
+
+struct kunit_binary_assert {
+	struct kunit_assert assert;
+	const char *operation;
+	const char *left_text;
+	long long left_value;
+	const char *right_text;
+	long long right_value;
+};
+
+void kunit_binary_assert_format(const struct kunit_assert *assert,
+				struct string_stream *stream);
+
+#define KUNIT_INIT_BINARY_ASSERT_STRUCT(test,				       \
+					type,				       \
+					op_str,				       \
+					left_str,			       \
+					left_val,			       \
+					right_str,			       \
+					right_val) {			       \
+	.assert = KUNIT_INIT_ASSERT_STRUCT(test,			       \
+					   type,			       \
+					   kunit_binary_assert_format),	       \
+	.operation = op_str,						       \
+	.left_text = left_str,						       \
+	.left_value = left_val,						       \
+	.right_text = right_str,					       \
+	.right_value = right_val					       \
+}
+
+struct kunit_binary_ptr_assert {
+	struct kunit_assert assert;
+	const char *operation;
+	const char *left_text;
+	const void *left_value;
+	const char *right_text;
+	const void *right_value;
+};
+
+void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
+				    struct string_stream *stream);
+
+#define KUNIT_INIT_BINARY_PTR_ASSERT_STRUCT(test,			       \
+					    type,			       \
+					    op_str,			       \
+					    left_str,			       \
+					    left_val,			       \
+					    right_str,			       \
+					    right_val) {		       \
+	.assert = KUNIT_INIT_ASSERT_STRUCT(test,			       \
+					   type,			       \
+					   kunit_binary_ptr_assert_format),    \
+	.operation = op_str,						       \
+	.left_text = left_str,						       \
+	.left_value = left_val,						       \
+	.right_text = right_str,					       \
+	.right_value = right_val					       \
+}
+
+struct kunit_binary_str_assert {
+	struct kunit_assert assert;
+	const char *operation;
+	const char *left_text;
+	const char *left_value;
+	const char *right_text;
+	const char *right_value;
+};
+
+void kunit_binary_str_assert_format(const struct kunit_assert *assert,
+				    struct string_stream *stream);
+
+#define KUNIT_INIT_BINARY_STR_ASSERT_STRUCT(test,			       \
+					    type,			       \
+					    op_str,			       \
+					    left_str,			       \
+					    left_val,			       \
+					    right_str,			       \
+					    right_val) {		       \
+	.assert = KUNIT_INIT_ASSERT_STRUCT(test,			       \
+					   type,			       \
+					   kunit_binary_str_assert_format),    \
+	.operation = op_str,						       \
+	.left_text = left_str,						       \
+	.left_value = left_val,						       \
+	.right_text = right_str,					       \
+	.right_value = right_val					       \
+}
+
+#endif /*  _KUNIT_ASSERT_H */
diff --git a/kunit/Makefile b/kunit/Makefile
index 275b565a0e81f..6dcbe309036b8 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_KUNIT) +=			test.o \
-					string-stream.o
+					string-stream.o \
+					assert.o
diff --git a/kunit/assert.c b/kunit/assert.c
new file mode 100644
index 0000000000000..86013d4cf891c
--- /dev/null
+++ b/kunit/assert.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Assertion and expectation serialization API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+#include <kunit/assert.h>
+
+void kunit_base_assert_format(const struct kunit_assert *assert,
+			      struct string_stream *stream)
+{
+	const char *expect_or_assert = NULL;
+
+	switch (assert->type) {
+	case KUNIT_EXPECTATION:
+		expect_or_assert = "EXPECTATION";
+		break;
+	case KUNIT_ASSERTION:
+		expect_or_assert = "ASSERTION";
+		break;
+	}
+
+	string_stream_add(stream, "%s FAILED at %s:%d\n",
+			 expect_or_assert, assert->file, assert->line);
+}
+
+void kunit_assert_print_msg(const struct kunit_assert *assert,
+			    struct string_stream *stream)
+{
+	if (assert->message.fmt)
+		string_stream_add(stream, "\n%pV", &assert->message);
+}
+
+void kunit_fail_assert_format(const struct kunit_assert *assert,
+			      struct string_stream *stream)
+{
+	kunit_base_assert_format(assert, stream);
+	string_stream_add(stream, "%pV", &assert->message);
+}
+
+void kunit_unary_assert_format(const struct kunit_assert *assert,
+			       struct string_stream *stream)
+{
+	struct kunit_unary_assert *unary_assert = container_of(
+			assert, struct kunit_unary_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	if (unary_assert->expected_true)
+		string_stream_add(stream,
+				 "\tExpected %s to be true, but is false\n",
+				 unary_assert->condition);
+	else
+		string_stream_add(stream,
+				 "\tExpected %s to be false, but is true\n",
+				 unary_assert->condition);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
+				     struct string_stream *stream)
+{
+	struct kunit_ptr_not_err_assert *ptr_assert = container_of(
+			assert, struct kunit_ptr_not_err_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	if (!ptr_assert->value) {
+		string_stream_add(stream,
+				 "\tExpected %s is not null, but is\n",
+				 ptr_assert->text);
+	} else if (IS_ERR(ptr_assert->value)) {
+		string_stream_add(stream,
+				 "\tExpected %s is not error, but is: %ld\n",
+				 ptr_assert->text,
+				 PTR_ERR(ptr_assert->value));
+	}
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_binary_assert_format(const struct kunit_assert *assert,
+				struct string_stream *stream)
+{
+	struct kunit_binary_assert *binary_assert = container_of(
+			assert, struct kunit_binary_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	string_stream_add(stream,
+			 "\tExpected %s %s %s, but\n",
+			 binary_assert->left_text,
+			 binary_assert->operation,
+			 binary_assert->right_text);
+	string_stream_add(stream, "\t\t%s == %lld\n",
+			 binary_assert->left_text,
+			 binary_assert->left_value);
+	string_stream_add(stream, "\t\t%s == %lld",
+			 binary_assert->right_text,
+			 binary_assert->right_value);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
+				    struct string_stream *stream)
+{
+	struct kunit_binary_ptr_assert *binary_assert = container_of(
+			assert, struct kunit_binary_ptr_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	string_stream_add(stream,
+			 "\tExpected %s %s %s, but\n",
+			 binary_assert->left_text,
+			 binary_assert->operation,
+			 binary_assert->right_text);
+	string_stream_add(stream, "\t\t%s == %pK\n",
+			 binary_assert->left_text,
+			 binary_assert->left_value);
+	string_stream_add(stream, "\t\t%s == %pK",
+			 binary_assert->right_text,
+			 binary_assert->right_value);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_binary_str_assert_format(const struct kunit_assert *assert,
+				    struct string_stream *stream)
+{
+	struct kunit_binary_str_assert *binary_assert = container_of(
+			assert, struct kunit_binary_str_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	string_stream_add(stream,
+			 "\tExpected %s %s %s, but\n",
+			 binary_assert->left_text,
+			 binary_assert->operation,
+			 binary_assert->right_text);
+	string_stream_add(stream, "\t\t%s == %s\n",
+			 binary_assert->left_text,
+			 binary_assert->left_value);
+	string_stream_add(stream, "\t\t%s == %s",
+			 binary_assert->right_text,
+			 binary_assert->right_value);
+	kunit_assert_print_msg(assert, stream);
+}
-- 
2.23.0.rc1.153.gdeed80330f-goog