Exceptions.cpp

/*************************************************************************************

	 cpl - cross platform library - v. 0.1.0.

	 Copyright (C) 2017 Janus Lynggaard Thorborg (www.jthorborg.com)

	 This program is free software: you can redistribute it and/or modify
	 it under the terms of the GNU General Public License as published by
	 the Free Software Foundation, either version 3 of the License, or
	 (at your option) any later version.

	 This program is distributed in the hope that it will be useful,
	 but WITHOUT ANY WARRANTY; without even the implied warranty of
	 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	 GNU General Public License for more details.

	 You should have received a copy of the GNU General Public License
	 along with this program.  If not, see <http://www.gnu.org/licenses/>.

	 See \licenses\ for additional details on licenses associated with this program.

 **************************************************************************************

	file:Exceptions.cpp

		Implementation of Exceptions.h

*************************************************************************************/

#include "Exceptions.h"
#include "Misc.h"
#include "CExclusiveFile.h"
#include "PlatformSpecific.h"

namespace cpl
{
	int GetLastOSError()
	{
		#ifdef CPL_WINDOWS
			return GetLastError();
		#else
			return errno;
		#endif
	}

	std::string GetLastOSErrorMessage(int errorToUse)
	{
		auto lastError = errorToUse;
		#ifdef CPL_WINDOWS
			char * apiPointer = nullptr;

			auto numChars = FormatMessageA
			(
				FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
				0,
				lastError,
				0,
				apiPointer,
				0,
				0
			);

			std::string ret(apiPointer, numChars);
			LocalFree(apiPointer);
			return ret;
		#else
			return "Error (" + std::to_string(lastError) + "): " + strerror(lastError);
		#endif
	}

	std::string GetLastOSErrorMessage()
	{
		return GetLastOSErrorMessage(GetLastOSError());
	}

	const std::string& GetExceptionLogFilePath()
	{
		using namespace cpl::Misc;
		static const std::string path = GetDirectoryPath() + "/" + programInfo.name + " exceptions.log";

		return path;
	}

	void CheckPruneExceptionLogFile()
	{
		static std::once_flag flag;

		std::call_once(
			flag,
			[] {

				const auto& path = GetExceptionLogFilePath();

				std::int64_t size = -1;

				{
					FILE* f = std::fopen(path.c_str(), "r");

					if (!f)
						return;

#ifdef CPL_WINDOWS
					struct _stat fstatbuffer;
					auto fd = _fileno(f);
					if (_fstat(fd, &fstatbuffer) == 0)
						size = fstatbuffer.st_size;
#else
					struct stat fstatbuffer;
					auto fd = fileno(f);
					if (fstat(fd, &fstatbuffer) == 0)
						size = fstatbuffer.st_size;
#endif

					std::fclose(f);
				}

				// bigger than 2 megabytes?
				if (size > 20e5)
				{
					char fsizebytes[256];

					cpl::sprintfs(fsizebytes, "%.1f", size / 10e5);

					auto answer = cpl::Misc::MsgBox(
						std::string("A log file for this program is ") + fsizebytes + " MB big.\nDo you want to clean it (harmless unless you want to report issues)?",
						programInfo.name + ": Large logfile detected",
						Misc::MsgStyle::sYesNoCancel | Misc::MsgIcon::iQuestion,
						nullptr,
						true
					);

					if (answer == Misc::MsgButton::bYes)
					{
						FILE* f = std::fopen(path.c_str(), "w");
						if (f != nullptr)
							std::fclose(f);
					}
				}

			}
		);
	}

	void LogException(const string_ref errorMessage)
	{
		using namespace cpl::Misc;
		CExclusiveFile exceptionLog;

		auto result = cpl::Misc::WaitOnCondition(
			1000,
			[&]() { return exceptionLog.open(GetExceptionLogFilePath(), exceptionLog.writeMode | exceptionLog.append, true); },
			10
		);

		if (!result)
			return;

		exceptionLog.newline();
		exceptionLog.write(("----------------" + GetDate() + ", " + GetTime() + "----------------").c_str());
		exceptionLog.newline();
		exceptionLog.write(("- Exception in \"" + programInfo.name + "\" v.\"" + std::to_string(programInfo.version) + "\"").c_str());
		exceptionLog.newline();
		exceptionLog.write(errorMessage.data(), errorMessage.size());
		exceptionLog.newline();
	}

	void CrashIfUserDoesntDebug(const string_ref errorMessage)
	{
		using namespace cpl::Misc;

		auto ret = MsgBox(errorMessage.string() + newl + newl + "Press yes to break after attaching a debugger. Press no to crash.", programInfo.name + ": Fatal error",
			MsgStyle::sYesNo | MsgIcon::iStop);

		if (ret == MsgButton::bYes)
		{
			CPL_BREAKIFDEBUGGED();
		}
	}

	bool IsDebuggerAttached()
	{
		return cpl::Misc::IsBeingDebugged();
	}
}