/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 *
 * kselftest_harness.h: simple C unit test helper.
 *
 * See documentation in Documentation/dev-tools/kselftest.rst
 *
 * API inspired by code.google.com/p/googletest
 */

/**
 * DOC: example
 *
 * .. code-block:: c
 *
 *    #include "../kselftest_harness.h"
 *
 *    TEST(standalone_test) {
 *      do_some_stuff;
 *      EXPECT_GT(10, stuff) {
 *         stuff_state_t state;
 *         enumerate_stuff_state(&state);
 *         TH_LOG("expectation failed with state: %s", state.msg);
 *      }
 *      more_stuff;
 *      ASSERT_NE(some_stuff, NULL) TH_LOG("how did it happen?!");
 *      last_stuff;
 *      EXPECT_EQ(0, last_stuff);
 *    }
 *
 *    FIXTURE(my_fixture) {
 *      mytype_t *data;
 *      int awesomeness_level;
 *    };
 *    FIXTURE_SETUP(my_fixture) {
 *      self->data = mytype_new();
 *      ASSERT_NE(NULL, self->data);
 *    }
 *    FIXTURE_TEARDOWN(my_fixture) {
 *      mytype_free(self->data);
 *    }
 *    TEST_F(my_fixture, data_is_good) {
 *      EXPECT_EQ(1, is_my_data_good(self->data));
 *    }
 *
 *    TEST_HARNESS_MAIN
 */

#ifndef __KSELFTEST_HARNESS_H
#define __KSELFTEST_HARNESS_H

#define _GNU_SOURCE
#include <asm/types.h>
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#define TEST_TIMEOUT_DEFAULT 30

/* Utilities exposed to the test definitions */
#ifndef TH_LOG_STREAM
#  define TH_LOG_STREAM stderr
#endif

#ifndef TH_LOG_ENABLED
#  define TH_LOG_ENABLED 1
#endif

/**
 * TH_LOG(fmt, ...)
 *
 * @fmt: format string
 * @...: optional arguments
 *
 * .. code-block:: c
 *
 *     TH_LOG(format, ...)
 *
 * Optional debug logging function available for use in tests.
 * Logging may be enabled or disabled by defining TH_LOG_ENABLED.
 * E.g., #define TH_LOG_ENABLED 1
 *
 * If no definition is provided, logging is enabled by default.
 *
 * If there is no way to print an error message for the process running the
 * test (e.g. not allowed to write to stderr), it is still possible to get the
 * ASSERT_* number for which the test failed.  This behavior can be enabled by
 * writing `_metadata->no_print = true;` before the check sequence that is
 * unable to print.  When an error occur, instead of printing an error message
 * and calling `abort(3)`, the test process call `_exit(2)` with the assert
 * number as argument, which is then printed by the parent process.
 */
#define TH_LOG(fmt, ...) do { \
        if (TH_LOG_ENABLED) \
                __TH_LOG(fmt, ##__VA_ARGS__); \
} while (0)

/* Unconditional logger for internal use. */
#define __TH_LOG(fmt, ...) \
                fprintf(TH_LOG_STREAM, "%s:%d:%s:" fmt "\n", \
                        __FILE__, __LINE__, _metadata->name, ##__VA_ARGS__)

/**
 * XFAIL(statement, fmt, ...)
 *
 * @statement: statement to run after reporting XFAIL
 * @fmt: format string
 * @...: optional arguments
 *
 * This forces a "pass" after reporting a failure with an XFAIL prefix,
 * and runs "statement", which is usually "return" or "goto skip".
 */
#define XFAIL(statement, fmt, ...) do { \
        if (TH_LOG_ENABLED) { \
                fprintf(TH_LOG_STREAM, "[  XFAIL!  ] " fmt "\n", \
                        ##__VA_ARGS__); \
        } \
        /* TODO: find a way to pass xfail to test runner process. */ \
        _metadata->passed = 1; \
        _metadata->trigger = 0; \
        statement; \
} while (0)

/**
 * TEST(test_name) - Defines the test function and creates the registration
 * stub
 *
 * @test_name: test name
 *
 * .. code-block:: c
 *
 *     TEST(name) { implementation }
 *
 * Defines a test by name.
 * Names must be unique and tests must not be run in parallel.  The
 * implementation containing block is a function and scoping should be treated
 * as such.  Returning early may be performed with a bare "return;" statement.
 *
 * EXPECT_* and ASSERT_* are valid in a TEST() { } context.
 */
#define TEST(test_name) __TEST_IMPL(test_name, -1)

/**
 * TEST_SIGNAL(test_name, signal)
 *
 * @test_name: test name
 * @signal: signal number
 *
 * .. code-block:: c
 *
 *     TEST_SIGNAL(name, signal) { implementation }
 *
 * Defines a test by name and the expected term signal.
 * Names must be unique and tests must not be run in parallel.  The
 * implementation containing block is a function and scoping should be treated
 * as such.  Returning early may be performed with a bare "return;" statement.
 *
 * EXPECT_* and ASSERT_* are valid in a TEST() { } context.
 */
#define TEST_SIGNAL(test_name, signal) __TEST_IMPL(test_name, signal)

#define __TEST_IMPL(test_name, _signal) \
        static void test_name(struct __test_metadata *_metadata); \
        static inline void wrapper_##test_name( \
                struct __test_metadata *_metadata, \
                struct __fixture_variant_metadata *variant) \
        { \
                test_name(_metadata); \
        } \
        static struct __test_metadata _##test_name##_object = \
                { .name = #test_name, \
                  .fn = &wrapper_##test_name, \
                  .fixture = &_fixture_global, \
                  .termsig = _signal, \
                  .timeout = TEST_TIMEOUT_DEFAULT, }; \
        static void __attribute__((constructor)) _register_##test_name(void) \
        { \
                __register_test(&_##test_name##_object); \
        } \
        static void test_name( \
                struct __test_metadata __attribute__((unused)) *_metadata)

/**
 * FIXTURE_DATA(datatype_name) - Wraps the struct name so we have one less
 * argument to pass around
 *
 * @datatype_name: datatype name
 *
 * .. code-block:: c
 *
 *     FIXTURE_DATA(datatype name)
 *
 * This call may be used when the type of the fixture data
 * is needed.  In general, this should not be needed unless
 * the *self* is being passed to a helper directly.
 */
#define FIXTURE_DATA(datatype_name) struct _test_data_##datatype_name

/**
 * FIXTURE(fixture_name) - Called once per fixture to setup the data and
 * register
 *
 * @fixture_name: fixture name
 *
 * .. code-block:: c
 *
 *     FIXTURE(datatype name) {
 *       type property1;
 *       ...
 *     };
 *
 * Defines the data provided to TEST_F()-defined tests as *self*.  It should be
 * populated and cleaned up using FIXTURE_SETUP() and FIXTURE_TEARDOWN().
 */
#define FIXTURE(fixture_name) \
        FIXTURE_VARIANT(fixture_name); \
        static struct __fixture_metadata _##fixture_name##_fixture_object = \
                { .name =  #fixture_name, }; \
        static void __attribute__((constructor)) \
        _register_##fixture_name##_data(void) \
        { \
                __register_fixture(&_##fixture_name##_fixture_object); \
        } \
        FIXTURE_DATA(fixture_name)

/**
 * FIXTURE_SETUP(fixture_name) - Prepares the setup function for the fixture.
 * *_metadata* is included so that EXPECT_* and ASSERT_* work correctly.
 *
 * @fixture_name: fixture name
 *
 * .. code-block:: c
 *
 *     FIXTURE_SETUP(fixture name) { implementation }
 *
 * Populates the required "setup" function for a fixture.  An instance of the
 * datatype defined with FIXTURE_DATA() will be exposed as *self* for the
 * implementation.
 *
 * ASSERT_* are valid for use in this context and will prempt the execution
 * of any dependent fixture tests.
 *
 * A bare "return;" statement may be used to return early.
 */
#define FIXTURE_SETUP(fixture_name) \
        void fixture_name##_setup( \
                struct __test_metadata __attribute__((unused)) *_metadata, \
                FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \
                const FIXTURE_VARIANT(fixture_name) \
                        __attribute__((unused)) *variant)

/**
 * FIXTURE_TEARDOWN(fixture_name)
 * *_metadata* is included so that EXPECT_* and ASSERT_* work correctly.
 *
 * @fixture_name: fixture name
 *
 * .. code-block:: c
 *
 *     FIXTURE_TEARDOWN(fixture name) { implementation }
 *
 * Populates the required "teardown" function for a fixture.  An instance of the
 * datatype defined with FIXTURE_DATA() will be exposed as *self* for the
 * implementation to clean up.
 *
 * A bare "return;" statement may be used to return early.
 */
#define FIXTURE_TEARDOWN(fixture_name) \
        void fixture_name##_teardown( \
                struct __test_metadata __attribute__((unused)) *_metadata, \
                FIXTURE_DATA(fixture_name) __attribute__((unused)) *self)

/**
 * FIXTURE_VARIANT(fixture_name) - Optionally called once per fixture
 * to declare fixture variant
 *
 * @fixture_name: fixture name
 *
 * .. code-block:: c
 *
 *     FIXTURE_VARIANT(datatype name) {
 *       type property1;
 *       ...
 *     };
 *
 * Defines type of constant parameters provided to FIXTURE_SETUP() and TEST_F()
 * as *variant*. Variants allow the same tests to be run with different
 * arguments.
 */
#define FIXTURE_VARIANT(fixture_name) struct _fixture_variant_##fixture_name

/**
 * FIXTURE_VARIANT_ADD(fixture_name, variant_name) - Called once per fixture
 * variant to setup and register the data
 *
 * @fixture_name: fixture name
 * @variant_name: name of the parameter set
 *
 * .. code-block:: c
 *
 *     FIXTURE_ADD(datatype name) {
 *       .property1 = val1;
 *       ...
 *     };
 *
 * Defines a variant of the test fixture, provided to FIXTURE_SETUP() and
 * TEST_F() as *variant*. Tests of each fixture will be run once for each
 * variant.
 */
#define FIXTURE_VARIANT_ADD(fixture_name, variant_name) \
        extern FIXTURE_VARIANT(fixture_name) \
                _##fixture_name##_##variant_name##_variant; \
        static struct __fixture_variant_metadata \
                _##fixture_name##_##variant_name##_object = \
                { .name = #variant_name, \
                  .data = &_##fixture_name##_##variant_name##_variant}; \
        static void __attribute__((constructor)) \
                _register_##fixture_name##_##variant_name(void) \
        { \
                __register_fixture_variant(&_##fixture_name##_fixture_object, \
                        &_##fixture_name##_##variant_name##_object);    \
        } \
        FIXTURE_VARIANT(fixture_name) \
                _##fixture_name##_##variant_name##_variant =

/**
 * TEST_F(fixture_name, test_name) - Emits test registration and helpers for
 * fixture-based test cases
 *
 * @fixture_name: fixture name
 * @test_name: test name
 *
 * .. code-block:: c
 *
 *     TEST_F(fixture, name) { implementation }
 *
 * Defines a test that depends on a fixture (e.g., is part of a test case).
 * Very similar to TEST() except that *self* is the setup instance of fixture's
 * datatype exposed for use by the implementation.
 *
 * Warning: use of ASSERT_* here will skip TEARDOWN.
 */
/* TODO(wad) register fixtures on dedicated test lists. */
#define TEST_F(fixture_name, test_name) \
        __TEST_F_IMPL(fixture_name, test_name, -1, TEST_TIMEOUT_DEFAULT)

#define TEST_F_SIGNAL(fixture_name, test_name, signal) \
        __TEST_F_IMPL(fixture_name, test_name, signal, TEST_TIMEOUT_DEFAULT)

#define TEST_F_TIMEOUT(fixture_name, test_name, timeout) \
        __TEST_F_IMPL(fixture_name, test_name, -1, timeout)

#define __TEST_F_IMPL(fixture_name, test_name, signal, tmout) \
        static void fixture_name##_##test_name( \
                struct __test_metadata *_metadata, \
                FIXTURE_DATA(fixture_name) *self, \
                const FIXTURE_VARIANT(fixture_name) *variant); \
        static inline void wrapper_##fixture_name##_##test_name( \
                struct __test_metadata *_metadata, \
                struct __fixture_variant_metadata *variant) \
        { \
                /* fixture data is alloced, setup, and torn down per call. */ \
                FIXTURE_DATA(fixture_name) self; \
                memset(&self, 0, sizeof(FIXTURE_DATA(fixture_name))); \
                fixture_name##_setup(_metadata, &self, variant->data); \
                /* Let setup failure terminate early. */ \
                if (!_metadata->passed) \
                        return; \
                fixture_name##_##test_name(_metadata, &self, variant->data); \
                fixture_name##_teardown(_metadata, &self); \
        } \
        static struct __test_metadata \
                      _##fixture_name##_##test_name##_object = { \
                .name = #test_name, \
                .fn = &wrapper_##fixture_name##_##test_name, \
                .fixture = &_##fixture_name##_fixture_object, \
                .termsig = signal, \
                .timeout = tmout, \
         }; \
        static void __attribute__((constructor)) \
                        _register_##fixture_name##_##test_name(void) \
        { \
                __register_test(&_##fixture_name##_##test_name##_object); \
        } \
        static void fixture_name##_##test_name( \
                struct __test_metadata __attribute__((unused)) *_metadata, \
                FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \
                const FIXTURE_VARIANT(fixture_name) \
                        __attribute__((unused)) *variant)

/**
 * TEST_HARNESS_MAIN - Simple wrapper to run the test harness
 *
 * .. code-block:: c
 *
 *     TEST_HARNESS_MAIN
 *
 * Use once to append a main() to the test file.
 */
#define TEST_HARNESS_MAIN \
        static void __attribute__((constructor)) \
        __constructor_order_last(void) \
        { \
                if (!__constructor_order) \
                        __constructor_order = _CONSTRUCTOR_ORDER_BACKWARD; \
        } \
        int main(int argc, char **argv) { \
                return test_harness_run(argc, argv); \
        }

/**
 * DOC: operators
 *
 * Operators for use in TEST() and TEST_F().
 * ASSERT_* calls will stop test execution immediately.
 * EXPECT_* calls will emit a failure warning, note it, and continue.
 */

/**
 * ASSERT_EQ(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_EQ(expected, measured): expected == measured
 */
#define ASSERT_EQ(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, ==, 1)

/**
 * ASSERT_NE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_NE(expected, measured): expected != measured
 */
#define ASSERT_NE(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, !=, 1)

/**
 * ASSERT_LT(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_LT(expected, measured): expected < measured
 */
#define ASSERT_LT(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, <, 1)

/**
 * ASSERT_LE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_LE(expected, measured): expected <= measured
 */
#define ASSERT_LE(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, <=, 1)

/**
 * ASSERT_GT(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_GT(expected, measured): expected > measured
 */
#define ASSERT_GT(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, >, 1)

/**
 * ASSERT_GE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_GE(expected, measured): expected >= measured
 */
#define ASSERT_GE(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, >=, 1)

/**
 * ASSERT_NULL(seen)
 *
 * @seen: measured value
 *
 * ASSERT_NULL(measured): NULL == measured
 */
#define ASSERT_NULL(seen) \
        __EXPECT(NULL, "NULL", seen, #seen, ==, 1)

/**
 * ASSERT_TRUE(seen)
 *
 * @seen: measured value
 *
 * ASSERT_TRUE(measured): measured != 0
 */
#define ASSERT_TRUE(seen) \
        __EXPECT(0, "0", seen, #seen, !=, 1)

/**
 * ASSERT_FALSE(seen)
 *
 * @seen: measured value
 *
 * ASSERT_FALSE(measured): measured == 0
 */
#define ASSERT_FALSE(seen) \
        __EXPECT(0, "0", seen, #seen, ==, 1)

/**
 * ASSERT_STREQ(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_STREQ(expected, measured): !strcmp(expected, measured)
 */
#define ASSERT_STREQ(expected, seen) \
        __EXPECT_STR(expected, seen, ==, 1)

/**
 * ASSERT_STRNE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * ASSERT_STRNE(expected, measured): strcmp(expected, measured)
 */
#define ASSERT_STRNE(expected, seen) \
        __EXPECT_STR(expected, seen, !=, 1)

/**
 * EXPECT_EQ(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_EQ(expected, measured): expected == measured
 */
#define EXPECT_EQ(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, ==, 0)

/**
 * EXPECT_NE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_NE(expected, measured): expected != measured
 */
#define EXPECT_NE(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, !=, 0)

/**
 * EXPECT_LT(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_LT(expected, measured): expected < measured
 */
#define EXPECT_LT(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, <, 0)

/**
 * EXPECT_LE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_LE(expected, measured): expected <= measured
 */
#define EXPECT_LE(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, <=, 0)

/**
 * EXPECT_GT(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_GT(expected, measured): expected > measured
 */
#define EXPECT_GT(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, >, 0)

/**
 * EXPECT_GE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_GE(expected, measured): expected >= measured
 */
#define EXPECT_GE(expected, seen) \
        __EXPECT(expected, #expected, seen, #seen, >=, 0)

/**
 * EXPECT_NULL(seen)
 *
 * @seen: measured value
 *
 * EXPECT_NULL(measured): NULL == measured
 */
#define EXPECT_NULL(seen) \
        __EXPECT(NULL, "NULL", seen, #seen, ==, 0)

/**
 * EXPECT_TRUE(seen)
 *
 * @seen: measured value
 *
 * EXPECT_TRUE(measured): 0 != measured
 */
#define EXPECT_TRUE(seen) \
        __EXPECT(0, "0", seen, #seen, !=, 0)

/**
 * EXPECT_FALSE(seen)
 *
 * @seen: measured value
 *
 * EXPECT_FALSE(measured): 0 == measured
 */
#define EXPECT_FALSE(seen) \
        __EXPECT(0, "0", seen, #seen, ==, 0)

/**
 * EXPECT_STREQ(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_STREQ(expected, measured): !strcmp(expected, measured)
 */
#define EXPECT_STREQ(expected, seen) \
        __EXPECT_STR(expected, seen, ==, 0)

/**
 * EXPECT_STRNE(expected, seen)
 *
 * @expected: expected value
 * @seen: measured value
 *
 * EXPECT_STRNE(expected, measured): strcmp(expected, measured)
 */
#define EXPECT_STRNE(expected, seen) \
        __EXPECT_STR(expected, seen, !=, 0)

#define ARRAY_SIZE(a)   (sizeof(a) / sizeof(a[0]))

/* Support an optional handler after and ASSERT_* or EXPECT_*.  The approach is
 * not thread-safe, but it should be fine in most sane test scenarios.
 *
 * Using __bail(), which optionally abort()s, is the easiest way to early
 * return while still providing an optional block to the API consumer.
 */
#define OPTIONAL_HANDLER(_assert) \
        for (; _metadata->trigger; _metadata->trigger = \
                        __bail(_assert, _metadata->no_print, _metadata->step))

#define __INC_STEP(_metadata) \
        if (_metadata->passed && _metadata->step < 255) \
                _metadata->step++;

#define __EXPECT(_expected, _expected_str, _seen, _seen_str, _t, _assert) do { \
        /* Avoid multiple evaluation of the cases */ \
        __typeof__(_expected) __exp = (_expected); \
        __typeof__(_seen) __seen = (_seen); \
        if (_assert) __INC_STEP(_metadata); \
        if (!(__exp _t __seen)) { \
                unsigned long long __exp_print = (uintptr_t)__exp; \
                unsigned long long __seen_print = (uintptr_t)__seen; \
                __TH_LOG("Expected %s (%llu) %s %s (%llu)", \
                         _expected_str, __exp_print, #_t, \
                         _seen_str, __seen_print); \
                _metadata->passed = 0; \
                /* Ensure the optional handler is triggered */ \
                _metadata->trigger = 1; \
        } \
} while (0); OPTIONAL_HANDLER(_assert)

#define __EXPECT_STR(_expected, _seen, _t, _assert) do { \
        const char *__exp = (_expected); \
        const char *__seen = (_seen); \
        if (_assert) __INC_STEP(_metadata); \
        if (!(strcmp(__exp, __seen) _t 0))  { \
                __TH_LOG("Expected '%s' %s '%s'.", __exp, #_t, __seen); \
                _metadata->passed = 0; \
                _metadata->trigger = 1; \
        } \
} while (0); OPTIONAL_HANDLER(_assert)

/* List helpers */
#define __LIST_APPEND(head, item) \
{ \
        /* Circular linked list where only prev is circular. */ \
        if (head == NULL) { \
                head = item; \
                item->next = NULL; \
                item->prev = item; \
                return; \
        } \
        if (__constructor_order == _CONSTRUCTOR_ORDER_FORWARD) { \
                item->next = NULL; \
                item->prev = head->prev; \
                item->prev->next = item; \
                head->prev = item; \
        } else { \
                item->next = head; \
                item->next->prev = item; \
                item->prev = item; \
                head = item; \
        } \
}

struct __test_metadata;
struct __fixture_variant_metadata;

/* Contains all the information about a fixture. */
struct __fixture_metadata {
        const char *name;
        struct __test_metadata *tests;
        struct __fixture_variant_metadata *variant;
        struct __fixture_metadata *prev, *next;
} _fixture_global __attribute__((unused)) = {
        .name = "global",
        .prev = &_fixture_global,
};

static struct __fixture_metadata *__fixture_list = &_fixture_global;
static int __constructor_order;

#define _CONSTRUCTOR_ORDER_FORWARD   1
#define _CONSTRUCTOR_ORDER_BACKWARD -1

static inline void __register_fixture(struct __fixture_metadata *f)
{
        __LIST_APPEND(__fixture_list, f);
}

struct __fixture_variant_metadata {
        const char *name;
        const void *data;
        struct __fixture_variant_metadata *prev, *next;
};

static inline void
__register_fixture_variant(struct __fixture_metadata *f,
                           struct __fixture_variant_metadata *variant)
{
        __LIST_APPEND(f->variant, variant);
}

/* Contains all the information for test execution and status checking. */
struct __test_metadata {
        const char *name;
        void (*fn)(struct __test_metadata *,
                   struct __fixture_variant_metadata *);
        pid_t pid;      /* pid of test when being run */
        struct __fixture_metadata *fixture;
        int termsig;
        int passed;
        int trigger; /* extra handler after the evaluation */
        int timeout;    /* seconds to wait for test timeout */
        bool timed_out; /* did this test timeout instead of exiting? */
        __u8 step;
        bool no_print; /* manual trigger when TH_LOG_STREAM is not available */
        struct __test_metadata *prev, *next;
};

/*
 * Since constructors are called in reverse order, reverse the test
 * list so tests are run in source declaration order.
 * https://gcc.gnu.org/onlinedocs/gccint/Initialization.html
 * However, it seems not all toolchains do this correctly, so use
 * __constructor_order to detect which direction is called first
 * and adjust list building logic to get things running in the right
 * direction.
 */
static inline void __register_test(struct __test_metadata *t)
{
        __LIST_APPEND(t->fixture->tests, t);
}

static inline int __bail(int for_realz, bool no_print, __u8 step)
{
        if (for_realz) {
                if (no_print)
                        _exit(step);
                abort();
        }
        return 0;
}

struct __test_metadata *__active_test;
static void __timeout_handler(int sig, siginfo_t *info, void *ucontext)
{
        struct __test_metadata *t = __active_test;

        /* Sanity check handler execution environment. */
        if (!t) {
                fprintf(TH_LOG_STREAM,
                        "no active test in SIGALRM handler!?\n");
                abort();
        }
        if (sig != SIGALRM || sig != info->si_signo) {
                fprintf(TH_LOG_STREAM,
                        "%s: SIGALRM handler caught signal %d!?\n",
                        t->name, sig != SIGALRM ? sig : info->si_signo);
                abort();
        }

        t->timed_out = true;
        kill(t->pid, SIGKILL);
}

void __wait_for_test(struct __test_metadata *t)
{
        struct sigaction action = {
                .sa_sigaction = __timeout_handler,
                .sa_flags = SA_SIGINFO,
        };
        struct sigaction saved_action;
        int status;

        if (sigaction(SIGALRM, &action, &saved_action)) {
                t->passed = 0;
                fprintf(TH_LOG_STREAM,
                        "%s: unable to install SIGALRM handler\n",
                        t->name);
                return;
        }
        __active_test = t;
        t->timed_out = false;
        alarm(t->timeout);
        waitpid(t->pid, &status, 0);
        alarm(0);
        if (sigaction(SIGALRM, &saved_action, NULL)) {
                t->passed = 0;
                fprintf(TH_LOG_STREAM,
                        "%s: unable to uninstall SIGALRM handler\n",
                        t->name);
                return;
        }
        __active_test = NULL;

        if (t->timed_out) {
                t->passed = 0;
                fprintf(TH_LOG_STREAM,
                        "%s: Test terminated by timeout\n", t->name);
        } else if (WIFEXITED(status)) {
                t->passed = t->termsig == -1 ? !WEXITSTATUS(status) : 0;
                if (t->termsig != -1) {
                        fprintf(TH_LOG_STREAM,
                                "%s: Test exited normally "
                                "instead of by signal (code: %d)\n",
                                t->name,
                                WEXITSTATUS(status));
                } else if (!t->passed) {
                        fprintf(TH_LOG_STREAM,
                                "%s: Test failed at step #%d\n",
                                t->name,
                                WEXITSTATUS(status));
                }
        } else if (WIFSIGNALED(status)) {
                t->passed = 0;
                if (WTERMSIG(status) == SIGABRT) {
                        fprintf(TH_LOG_STREAM,
                                "%s: Test terminated by assertion\n",
                                t->name);
                } else if (WTERMSIG(status) == t->termsig) {
                        t->passed = 1;
                } else {
                        fprintf(TH_LOG_STREAM,
                                "%s: Test terminated unexpectedly "
                                "by signal %d\n",
                                t->name,
                                WTERMSIG(status));
                }
        } else {
                fprintf(TH_LOG_STREAM,
                        "%s: Test ended in some other way [%u]\n",
                        t->name,
                        status);
        }
}

void __run_test(struct __fixture_metadata *f,
                struct __fixture_variant_metadata *variant,
                struct __test_metadata *t)
{
        /* reset test struct */
        t->passed = 1;
        t->trigger = 0;
        t->step = 0;
        t->no_print = 0;

        printf("[ RUN      ] %s%s%s.%s\n",
               f->name, variant->name[0] ? "." : "", variant->name, t->name);
        t->pid = fork();
        if (t->pid < 0) {
                printf("ERROR SPAWNING TEST CHILD\n");
                t->passed = 0;
        } else if (t->pid == 0) {
                t->fn(t, variant);
                /* return the step that failed or 0 */
                _exit(t->passed ? 0 : t->step);
        } else {
                __wait_for_test(t);
        }
        printf("[     %4s ] %s%s%s.%s\n", (t->passed ? "OK" : "FAIL"),
               f->name, variant->name[0] ? "." : "", variant->name, t->name);
}

static int test_harness_run(int __attribute__((unused)) argc,
                            char __attribute__((unused)) **argv)
{
        struct __fixture_variant_metadata no_variant = { .name = "", };
        struct __fixture_variant_metadata *v;
        struct __fixture_metadata *f;
        struct __test_metadata *t;
        int ret = 0;
        unsigned int case_count = 0, test_count = 0;
        unsigned int count = 0;
        unsigned int pass_count = 0;

        for (f = __fixture_list; f; f = f->next) {
                for (v = f->variant ?: &no_variant; v; v = v->next) {
                        case_count++;
                        for (t = f->tests; t; t = t->next)
                                test_count++;
                }
        }

        /* TODO(wad) add optional arguments similar to gtest. */
        printf("[==========] Running %u tests from %u test cases.\n",
               test_count, case_count);
        for (f = __fixture_list; f; f = f->next) {
                for (v = f->variant ?: &no_variant; v; v = v->next) {
                        for (t = f->tests; t; t = t->next) {
                                count++;
                                __run_test(f, v, t);
                                if (t->passed)
                                        pass_count++;
                                else
                                        ret = 1;
                        }
                }
        }
        printf("[==========] %u / %u tests passed.\n", pass_count, count);
        printf("[  %s  ]\n", (ret ? "FAILED" : "PASSED"));
        return ret;
}

static void __attribute__((constructor)) __constructor_order_first(void)
{
        if (!__constructor_order)
                __constructor_order = _CONSTRUCTOR_ORDER_FORWARD;
}

#endif  /* __KSELFTEST_HARNESS_H */