catch2/include/internal/catch_fatal_condition.h

/*
 *  Created by Phil on 21/08/2014
 *  Copyright 2014 Two Blue Cubes Ltd. All rights reserved.
 *
 *  Distributed under the Boost Software License, Version 1.0. (See accompanying
 *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 *
 */
#ifndef TWOBLUECUBES_CATCH_FATAL_CONDITION_H_INCLUDED
#define TWOBLUECUBES_CATCH_FATAL_CONDITION_H_INCLUDED

#include "catch_platform.h"
#include "catch_compiler_capabilities.h"

#include <cassert>

namespace Catch {

    // Wrapper for platform-specific fatal error (signals/SEH) handlers
    //
    // Tries to be cooperative with other handlers, and not step over
    // other handlers. This means that unknown structured exceptions
    // are passed on, previous signal handlers are called, and so on.
    //
    // Can only be instantiated once, and assumes that once a signal
    // is caught, the binary will end up terminating. Thus, there
    class FatalConditionHandler {
        bool m_started = false;

        // Install/disengage implementation for specific platform.
        // Should be if-defed to work on current platform, can assume
        // engage-disengage 1:1 pairing.
        void engage_platform();
        void disengage_platform();
    public:
        // Should also have platform-specific implementations as needed
        FatalConditionHandler();
        ~FatalConditionHandler();

        void engage() {
            assert(!m_started && "Handler cannot be installed twice.");
            m_started = true;
            engage_platform();
        }

        void disengage() {
            assert(m_started && "Handler cannot be uninstalled without being installed first");
            m_started = false;
            disengage_platform();
        }
    };

    //! Simple RAII guard for (dis)engaging the FatalConditionHandler
    class FatalConditionHandlerGuard {
        FatalConditionHandler* m_handler;
    public:
        FatalConditionHandlerGuard(FatalConditionHandler* handler):
            m_handler(handler) {
            m_handler->engage();
        }
        ~FatalConditionHandlerGuard() {
            m_handler->disengage();
        }
    };

} // end namespace Catch

#endif // TWOBLUECUBES_CATCH_FATAL_CONDITION_H_INCLUDED