polyvox/include/PolyVox/Impl/ExceptionsImpl.h

/*******************************************************************************
* The MIT License (MIT)
*
* Copyright (c) 2015 David Williams and Matthew Williams
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*******************************************************************************/

#ifndef __PolyVox_ExceptionsImpl_H__
#define __PolyVox_ExceptionsImpl_H__

#include "../Config.h"
#include "../Exceptions.h"

#include "LoggingImpl.h" // Exceptions can log when they are thrown.

#include <cstdlib>  // For std::exit
#include <iostream> // For std::cerr
#include <sstream>
#include <csignal>

#ifdef POLYVOX_THROW_ENABLED

	namespace PolyVox
	{
		namespace Impl
		{
			template< typename ExceptionType, typename ... Args >
			void polyvox_throw(Args const& ... messageArgs)
			{
				std::string message = argListToString(messageArgs...);
#ifdef POLYVOX_LOG_ERROR_ENABLED
				getLoggerInstance()->logErrorMessage(message);
#endif
				throw ExceptionType(message);
			}

			template< typename ExceptionType, typename ... Args >
			void polyvox_throw_if(bool condition, Args const& ... messageArgs)
			{
				if (condition) { polyvox_throw<ExceptionType>(messageArgs...); }
			}
		}
	}

	#define POLYVOX_THROW(type, ...) PolyVox::Impl::polyvox_throw<type>(__VA_ARGS__)
	#define POLYVOX_THROW_IF(condition, type, ...) PolyVox::Impl::polyvox_throw_if<type>(condition, __VA_ARGS__)

#else

	// This stuff should possibly be in the 'Impl' namespace, but it may be complex and it's not
	// clear if this ability to disable throwing of exceptions is useful in the long term anyway.
	namespace PolyVox
	{
		typedef void(*ThrowHandler)(std::exception& e, const char* file, int line);

		inline void defaultThrowHandler(std::exception& e, const char* file, int line)
		{
			std::stringstream ss; \
				ss << "\n"; \
				ss << "    PolyVox exception thrown!"; \
				ss << "    ========================="; \
				ss << "    PolyVox has tried to throw an exception but it was built without support"; \
				ss << "    for exceptions. In this scenario PolyVox will call a 'throw handler'"; \
				ss << "    and this message is being printed by the default throw handler."; \
				ss << "\n"; \
				ss << "    If you don't want to enable exceptions then you should try to determine why"; \
				ss << "    this exception was thrown and make sure it doesn't happen again. If it was"; \
				ss << "    due to something like an invalid argument to a function then you should be"; \
				ss << "    able to fix it quite easily by validating parameters as appropriate. More"; \
				ss << "    complex exception scenarios (out of memory, etc) might be harder to fix and"; \
				ss << "    you should replace this default handler with something which is more"; \
				ss << "    meaningful to your users."; \
				ss << "\n"; \
				ss << "    Exception details"; \
				ss << "    -----------------"; \
				ss << "    Line:    " << line; \
				ss << "    File:    " << file; \
				ss << "    Message: " << e.what(); \
				ss << "\n"; \
				PolyVox::Impl::getLoggerInstance()->logFatalMessage(ss.str()); \
				POLYVOX_HALT(); \
		}

		inline ThrowHandler& getThrowHandlerInstance()
		{
			static ThrowHandler s_fThrowHandler = &defaultThrowHandler;
			return s_fThrowHandler;
		}

		inline ThrowHandler getThrowHandler()
		{
			return getThrowHandlerInstance();
		}

		inline void setThrowHandler(ThrowHandler fNewHandler)
		{
			getThrowHandlerInstance() = fNewHandler;
		}
	}

	#define POLYVOX_THROW_IF(condition, type, message) \
		/* We use the do...while(0) construct in our macros (for reasons see here: http://stackoverflow.com/a/154138) \
		but Visual Studio gives unhelpful 'conditional expression is constant' warnings. The recommended solution \
		(http://stackoverflow.com/a/1946485) is to disable these warnings. */ \
		POLYVOX_MSC_WARNING_PUSH \
		POLYVOX_DISABLE_MSC_WARNING(4127) \
		do \
		{ \
			if ((condition)) \
			{ \
				std::stringstream ss; \
				ss << message; \
				PolyVox::Impl::getLoggerInstance()->logErrorMessage(ss.str()); \
				type except = (type)(ss.str()); \
				getThrowHandler()((except), __FILE__, __LINE__); \
			} \
		} while(0) \
		POLYVOX_MSC_WARNING_POP

	#define POLYVOX_THROW(type, message) \
		/* We use the do...while(0) construct in our macros (for reasons see here: http://stackoverflow.com/a/154138) \
		but Visual Studio gives unhelpful 'conditional expression is constant' warnings. The recommended solution \
		(http://stackoverflow.com/a/1946485) is to disable these warnings. */ \
		POLYVOX_MSC_WARNING_PUSH \
		POLYVOX_DISABLE_MSC_WARNING(4127) \
		do \
		{ \
			std::stringstream ss; \
			ss << message; \
			PolyVox::Impl::getLoggerInstance()->logErrorMessage(ss.str()); \
			type except = (type)(ss.str()); \
			getThrowHandler()((except), __FILE__, __LINE__); \
		} while(0) \
		POLYVOX_MSC_WARNING_POP

#endif

#endif //__PolyVox_ExceptionsImpl_H__