test-bench.h

/*
 * This file is part of libgsutils
 * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All Rights Reserved.
 * Author: GreenSocs 2022
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
/*
 * GTest helper to workaround SystemC limitations regarding its non-resettable
 nature.
 *
 * You can use the TEST_BENCH macro as you would use the TEST_F GTest macro.
 * Your fixture class must inherit from the TestBench class.
 *
 * Before each test, the test program is forked so that it starts from a fresh
 * SystemC environment.
 *
 *
 * Using GDB
 * =========
 *
 * Note that debugging with GDB is a little more involved, because of the forks.
 * You can do something like this:
 *
 * (gdb) set detach-on-fork off
 * (gdb) set non-stop on
 * (gdb) b somewhere
 * (gdb) r
 * Thread 2.1 "xxx" hit Breakpoint 1, somewhere() (...)
    at ...
 
 * (gdb) thread 2.1
 * (gdb) ... you can now debug as normal in the child
 *
 * Note that in non-stop mode, other inferiors are still running. To stop one,
 * select it with the `thread' command and issue the `interrupt' command.
 *
 * Example
 * =======
 *
 * class MyTestBench : public TestBench {
 * private:
 *     SomeModule m_module_under_test;
 *     AnotherModule m_mock_module;
 *
 * public:
 *     MyTestBench(const sc_core::sc_module_name &n)
 *         : TestBench(n)
 *         , m_module_under_test("module-under-test")
 *         , m_mock_module("mock-module")
 *     {
 * m_mock_module.target_socket.bind(m_module_under_test.initiator_socket);
 *     }
 * };
 *
 * TEST_BENCH(MyTestBench, Test0)
 * {
 *     m_module_under_test.do_something();
 *     ASSERT_TRUE(m_mock_module.expected_result());
 * }
 *
 * int sc_main(int argc, char *argv[])
 * {
 *     ::testing::InitGoogleTest(&argc, argv);
 *     return RUN_ALL_TESTS();
 * }
 *
 */
 
#ifndef _GREENSOCS_GSUTILS_TESTS_TEST_BENCH_H
#define _GREENSOCS_GSUTILS_TESTS_TEST_BENCH_H
 
#include <systemc>
 
#include <gtest/gtest.h>
#include <scp/report.h>
 
class TestBench : public sc_core::sc_module
{
protected:
    virtual void test_bench_body() = 0;
 
public:
    TestBench(const sc_core::sc_module_name& n): sc_core::sc_module(n) {}
};
template <class T>
class TestBenchEnv : public ::testing::Environment
{
    // Would be nice to be a smart pointer, but sc_bind takes a pointer.
    T* instance;
 
public:
    void SetUp() override { instance = new T(); }
    void TearDown() override { delete instance; }
    T* get() { return instance; }
};
 
#if !defined(_WIN32)
#include <sys/types.h>
#include <sys/wait.h>
#endif
#include <unistd.h>
 
template <class T>
static inline void run_test_bench(T* instance)
{
    sc_spawn(sc_bind(&T::test_bench_body, instance));
    sc_core::sc_start();
}
 
#define TEST_BENCH_NAME(name) TestBench__##name
 
#define TEST_BENCH(test_bench, name)                                                         \
    class TEST_BENCH_NAME(name): public test_bench                                           \
    {                                                                                        \
    public:                                                                                  \
        void test_bench_body() override;                                                     \
                                                                                             \
        TEST_BENCH_NAME(name)(): test_bench(#name) {}                                        \
    };                                                                                       \
    testing::Environment* const test_bench_env##name = testing::AddGlobalTestEnvironment(    \
        new TestBenchEnv<TEST_BENCH_NAME(name)>());                                          \
    TEST(TEST_BENCH_NAME(name), name)                                                        \
    {                                                                                        \
        run_test_bench<TEST_BENCH_NAME(name)>(                                               \
            static_cast<TestBenchEnv<TEST_BENCH_NAME(name)>*>(test_bench_env##name)->get()); \
    }                                                                                        \
    void TEST_BENCH_NAME(name)::test_bench_body()
 
#endif