/*
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <stdnoreturn.h>

/*
 * Log with the HFTEST_LOG_PREFIX and a new line. The zero is added so there is
 * always at least one variadic argument.
 */
#define HFTEST_LOG(...) HFTEST_LOG_IMPL(__VA_ARGS__, 0)
#define HFTEST_LOG_IMPL(format, ...) \
	dlog("%s" format "\n", HFTEST_LOG_PREFIX, __VA_ARGS__)

/* Helper to wrap the argument in quotes. */
#define HFTEST_STR(str) #str

/*
 * Sections are names such that when the linker sorts them, all entries for the
 * same test suite are contiguous and the set up and tear down entries come
 * before the tests. This order simplifies test discovery in the running image.
 */
#define HFTEST_SET_UP_SECTION(suite_name) \
	HFTEST_STR(.hftest.suite.suite_name .1set_up)
#define HFTEST_TEAR_DOWN_SECTION(suite_name) \
	HFTEST_STR(.hftest.suite.suite_name .1tear_down)
#define HFTEST_TEST_SECTION(suite_name, test_name) \
	HFTEST_STR(.hftest.suite.suite_name .2test.test_name)
#define HFTEST_SERVICE_SECTION(service_name) \
	HFTEST_STR(.hftest.service.service_name)

/* Helpers to construct unique identifiers. */
#define HFTEST_SET_UP_STRUCT(suite_name) hftest_set_up_##suite_name
#define HFTEST_TEAR_DOWN_STRUCT(suite_name) hftest_tear_down_##suite_name
#define HFTEST_TEST_STRUCT(suite_name, test_name) \
	hftest_test_##suite_name##_##test_name
#define HFTEST_SERVICE_STRUCT(service_name) hftest_service_##service_name

#define HFTEST_SET_UP_FN(suite_name) hftest_set_up_fn_##suite_name
#define HFTEST_TEAR_DOWN_FN(suite_name) hftest_tear_down_fn_##suite_name
#define HFTEST_TEST_FN(suite_name, test_name) \
	hftest_test_fn_##suite_name##_##test_name
#define HFTEST_SERVICE_FN(service_name) hftest_service_fn_##service_name

/* Register test functions. */
#define HFTEST_SET_UP(suite_name)                                           \
	static void HFTEST_SET_UP_FN(suite_name)(void);                     \
	const struct hftest_test __attribute__((used))                      \
		__attribute__((section(HFTEST_SET_UP_SECTION(suite_name)))) \
			HFTEST_SET_UP_STRUCT(suite_name) = {                \
				.suite = #suite_name,                       \
				.kind = HFTEST_KIND_SET_UP,                 \
				.fn = HFTEST_SET_UP_FN(suite_name),         \
	};                                                                  \
	static void HFTEST_SET_UP_FN(suite_name)(void)

#define HFTEST_TEAR_DOWN(suite_name)                                           \
	static void HFTEST_TEAR_DOWN_FN(suite_name)(void);                     \
	const struct hftest_test __attribute__((used))                         \
		__attribute__((section(HFTEST_TEAR_DOWN_SECTION(suite_name)))) \
			HFTEST_TEAR_DOWN_STRUCT(suite_name) = {                \
				.suite = #suite_name,                          \
				.kind = HFTEST_KIND_TEAR_DOWN,                 \
				.fn = HFTEST_TEAR_DOWN_FN(suite_name),         \
	};                                                                     \
	static void HFTEST_TEAR_DOWN_FN(suite_name)(void)

#define HFTEST_TEST(suite_name, test_name)                             \
	static void HFTEST_TEST_FN(suite_name, test_name)(void);       \
	const struct hftest_test __attribute__((used)) __attribute__(  \
		(section(HFTEST_TEST_SECTION(suite_name, test_name)))) \
		HFTEST_TEST_STRUCT(suite_name, test_name) = {          \
			.suite = #suite_name,                          \
			.kind = HFTEST_KIND_TEST,                      \
			.name = #test_name,                            \
			.fn = HFTEST_TEST_FN(suite_name, test_name),   \
	};                                                             \
	static void HFTEST_TEST_FN(suite_name, test_name)(void)

#define HFTEST_TEST_SERVICE(service_name)                                      \
	static void HFTEST_SERVICE_FN(service_name)(void);                     \
	const struct hftest_test __attribute__((used))                         \
		__attribute__((section(HFTEST_SERVICE_SECTION(service_name)))) \
			HFTEST_SERVICE_STRUCT(service_name) = {                \
				.kind = HFTEST_KIND_SERVICE,                   \
				.name = #service_name,                         \
				.fn = HFTEST_SERVICE_FN(service_name),         \
	};                                                                     \
	static void HFTEST_SERVICE_FN(service_name)(void)

/* Context for tests. */
struct hftest_context {
	uint32_t failures;
	noreturn void (*abort)(void);

	/* These are used in services. */
	void *send;
	void *recv;
};

struct hftest_context *hftest_get_context(void);

/* A test case. */
typedef void (*hftest_test_fn)(void);

enum hftest_kind {
	HFTEST_KIND_SET_UP = 0,
	HFTEST_KIND_TEST = 1,
	HFTEST_KIND_TEAR_DOWN = 2,
	HFTEST_KIND_SERVICE = 3,
};

/**
 * The .hftest section contains an array of this struct which describes the test
 * functions contained in the image allowing the image to inspect the tests it
 * contains.
 */
struct hftest_test {
	const char *suite;
	enum hftest_kind kind;
	const char *name;
	hftest_test_fn fn;
};

/*
 * This union can store any of the primitive types supported by the assertion
 * macros.
 *
 * It does not include pointers as comparison of pointers is not often needed
 * and could be a mistake for string comparison. If pointer comparison is needed
 * and explicit assertion such as ASSERT_PTR_EQ() would be more appropriate.
 */
union hftest_any {
	bool b;
	char c;
	signed char sc;
	unsigned char uc;
	signed short ss;
	unsigned short us;
	signed int si;
	unsigned int ui;
	signed long int sli;
	unsigned long int uli;
	signed long long int slli;
	unsigned long long int ulli;
};

/* _Generic formatting doesn't seem to be supported so doing this manually. */
/* clang-format off */

/* Select the union member to match the type of the expression. */
#define hftest_any_get(any, x)                      \
	_Generic((x),                               \
		bool:                   (any).b,    \
		char:                   (any).c,    \
		signed char:            (any).sc,   \
		unsigned char:          (any).uc,   \
		signed short:           (any).ss,   \
		unsigned short:         (any).us,   \
		signed int:             (any).si,   \
		unsigned int:           (any).ui,   \
		signed long int:        (any).sli,  \
		unsigned long int:      (any).uli,  \
		signed long long int:   (any).slli, \
		unsigned long long int: (any).ulli)

/*
 * dlog format specifier for types. Note, these aren't the standard specifiers
 * for the types.
 */
#define hftest_dlog_format(x)                 \
	_Generic((x),                         \
		bool:                   "%u", \
		char:                   "%c", \
		signed char:            "%d", \
		unsigned char:          "%u", \
		signed short:           "%d", \
		unsigned short:         "%u", \
		signed int:             "%d", \
		unsigned int:           "%u", \
		signed long int:        "%d", \
		unsigned long int:      "%u", \
		signed long long int:   "%d", \
		unsigned long long int: "%u")

/* clang-format on */

#define HFTEST_LOG_FAILURE() \
	dlog(HFTEST_LOG_PREFIX "Failure: %s:%u\n", __FILE__, __LINE__);

#define HFTEST_ASSERT_OP(lhs, rhs, op, fatal)                              \
	do {                                                               \
		union hftest_any lhs_value;                                \
		union hftest_any rhs_value;                                \
		hftest_any_get(lhs_value, lhs) = (lhs);                    \
		hftest_any_get(rhs_value, rhs) = (rhs);                    \
		if (!(hftest_any_get(lhs_value, lhs)                       \
			      op hftest_any_get(rhs_value, rhs))) {        \
			struct hftest_context *ctx = hftest_get_context(); \
			++ctx->failures;                                   \
			HFTEST_LOG_FAILURE();                              \
			dlog(HFTEST_LOG_PREFIX HFTEST_LOG_INDENT           \
			     "%s %s %s (%s=",                              \
			     #lhs, #op, #rhs, #lhs);                       \
			dlog(hftest_dlog_format(lhs),                      \
			     hftest_any_get(lhs_value, lhs));              \
			dlog(", %s=", #rhs);                               \
			dlog(hftest_dlog_format(rhs),                      \
			     hftest_any_get(rhs_value, rhs));              \
			dlog(")\n");                                       \
			if (fatal) {                                       \
				ctx->abort();                              \
			}                                                  \
		}                                                          \
	} while (0)

/**
 * Select the service to run in a service VM.
 */
#define HFTEST_SERVICE_SELECT(vm_id, service, send_buffer)                    \
	do {                                                                  \
		struct hf_vcpu_run_return run_res;                            \
                                                                              \
		/*                                                            \
		 * Let the service configure its mailbox and wait for a       \
		 * message.                                                   \
		 */                                                           \
		run_res = hf_vcpu_run(vm_id, 0);                              \
		ASSERT_EQ(run_res.code, HF_VCPU_RUN_WAIT_FOR_INTERRUPT);      \
                                                                              \
		/* Send the selected service to run and let it be handled. */ \
		memcpy(send_buffer, service, strlen(service));                \
		ASSERT_EQ(hf_mailbox_send(vm_id, strlen(service)), 0);        \
		run_res = hf_vcpu_run(vm_id, 0);                              \
		ASSERT_EQ(run_res.code, HF_VCPU_RUN_YIELD);                   \
	} while (0)

#define HFTEST_SERVICE_SEND_BUFFER() hftest_get_context()->send
#define HFTEST_SERVICE_RECV_BUFFER() hftest_get_context()->recv