/*-------------------------------------------------------------------------
 * drawElements Quality Program Helper Library
 * -------------------------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *//*!
 * \file
 * \brief System handler handler override
 *//*--------------------------------------------------------------------*/

#include "qpCrashHandler.h"
#include "qpDebugOut.h"

#include "deThread.h"
#include "deMemory.h"
#include "deString.h"
#include "deMutex.h"

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>

#if (DE_OS == DE_OS_UNIX)
#	include <unistd.h>
#	include <execinfo.h>
#	include <errno.h>
#	include <inttypes.h>
#endif

#if 0
#	define DBGPRINT(X) qpPrintf X
#else
#	define DBGPRINT(X)
#endif

/* Crash info write helper. */
static void writeInfoFormat (qpWriteCrashInfoFunc writeFunc, void* userPtr, const char* format, ...)
{
	char		buf[256];
	va_list		ap;

	va_start(ap, format);
	vsnprintf(buf, sizeof(buf), format, ap);
	va_end(ap);

	writeFunc(userPtr, buf);
}

/* Shared crash info. */
typedef enum qpCrashType_e
{
	QP_CRASHTYPE_SEGMENTATION_FAULT = 0,
	QP_CRASHTYPE_ASSERT,
	QP_CRASHTYPE_UNHANDLED_EXCEPTION,
	QP_CRASHTYPE_OTHER,

	QP_CRASHTYPE_LAST
} qpCrashType;

typedef struct qpCrashInfo_s
{
	qpCrashType						type;
	const char*						message;
	const char*						file;
	int								line;
} qpCrashInfo;

static void qpCrashInfo_init (qpCrashInfo* info)
{
	info->type		= QP_CRASHTYPE_LAST;
	info->message	= DE_NULL;
	info->file		= DE_NULL;
	info->line		= 0;
}

static void qpCrashInfo_set (qpCrashInfo* info, qpCrashType type, const char* message, const char* file, int line)
{
	info->type		= type;
	info->message	= message;
	info->file		= file;
	info->line		= line;
}

static void qpCrashInfo_write (qpCrashInfo* info, qpWriteCrashInfoFunc writeInfo, void* userPtr)
{
	switch (info->type)
	{
		case QP_CRASHTYPE_SEGMENTATION_FAULT:
			writeInfoFormat(writeInfo, userPtr, "Segmentation fault: '%s'\n", info->message);
			break;

		case QP_CRASHTYPE_UNHANDLED_EXCEPTION:
			writeInfoFormat(writeInfo, userPtr, "Unhandled exception: '%s'\n", info->message);
			break;

		case QP_CRASHTYPE_ASSERT:
			writeInfoFormat(writeInfo, userPtr, "Assertion '%s' failed at %s:%d\n",
							info->message,
							info->file,
							info->line);
			break;

		case QP_CRASHTYPE_OTHER:
		default:
			writeInfoFormat(writeInfo, userPtr, "Crash: '%s'\n", info->message);
			break;
	}
}

static void defaultWriteInfo (void* userPtr, const char* infoString)
{
	DE_UNREF(userPtr);
	qpPrintf("%s", infoString);
}

static void defaultCrashHandler (qpCrashHandler* crashHandler, void* userPtr)
{
	DE_UNREF(userPtr);
	qpCrashHandler_writeCrashInfo(crashHandler, defaultWriteInfo, DE_NULL);
	qpDief("Test process crashed");
}

#if (DE_OS == DE_OS_WIN32) && (DE_COMPILER == DE_COMPILER_MSC)

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* DbgHelp.h generates C4091 */
#pragma warning (push)
#pragma warning (disable: 4091)
#include <DbgHelp.h>
#pragma warning (pop)

struct qpCrashHandler_s
{
	qpCrashHandlerFunc				crashHandlerFunc;
	void*							handlerUserPointer;

	deMutex							crashHandlerLock;
	qpCrashInfo						crashInfo;
	deUintptr						crashAddress;

	LPTOP_LEVEL_EXCEPTION_FILTER	oldExceptionFilter;
};

qpCrashHandler*		g_crashHandler = DE_NULL;

static LONG WINAPI unhandledExceptionFilter (struct _EXCEPTION_POINTERS* info)
{
	qpCrashType crashType	= QP_CRASHTYPE_LAST;
	const char*	reason		= DE_NULL;

	/* Skip breakpoints. */
	if (info->ExceptionRecord->ExceptionCode == EXCEPTION_BREAKPOINT)
	{
		DBGPRINT(("qpCrashHandler::unhandledExceptionFilter(): breakpoint\n"));
		return EXCEPTION_CONTINUE_SEARCH;
	}

	/* If no handler present (how could that be?), don't handle. */
	if (g_crashHandler == DE_NULL)
	{
		DBGPRINT(("qpCrashHandler::unhandledExceptionFilter(): no crash handler registered\n"));
		return EXCEPTION_CONTINUE_SEARCH;
	}

	/* If we have a debugger, let it handle the exception. */
	if (IsDebuggerPresent())
	{
		DBGPRINT(("qpCrashHandler::unhandledExceptionFilter(): debugger present\n"));
		return EXCEPTION_CONTINUE_SEARCH;
	}

	/* Acquire crash handler lock. Otherwise we might get strange behavior when multiple threads enter crash handler simultaneously. */
	deMutex_lock(g_crashHandler->crashHandlerLock);

	/* Map crash type. */
	switch (info->ExceptionRecord->ExceptionCode)
	{
		case EXCEPTION_ACCESS_VIOLATION:
			crashType	= QP_CRASHTYPE_SEGMENTATION_FAULT;
			reason		= "Access violation";
			break;

		case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
			crashType	= QP_CRASHTYPE_SEGMENTATION_FAULT;
			reason		= "Array bounds exceeded";
			break;

		case EXCEPTION_ILLEGAL_INSTRUCTION:
			crashType	= QP_CRASHTYPE_OTHER;
			reason		= "Illegal instruction";
			break;

		case EXCEPTION_STACK_OVERFLOW:
			crashType	= QP_CRASHTYPE_OTHER;
			reason		= "Stack overflow";
			break;

		default:
			/* \todo [pyry] Others. */
			crashType	= QP_CRASHTYPE_OTHER;
			reason		= "";
			break;
	}

	/* Store reason. */
	qpCrashInfo_set(&g_crashHandler->crashInfo, crashType, reason, __FILE__, __LINE__);

	/* Store win32-specific crash info. */
	g_crashHandler->crashAddress = (deUintptr)info->ExceptionRecord->ExceptionAddress;

	/* Handle the crash. */
	DBGPRINT(("qpCrashHandler::unhandledExceptionFilter(): handled quietly\n"));
	if (g_crashHandler->crashHandlerFunc != DE_NULL)
		g_crashHandler->crashHandlerFunc(g_crashHandler, g_crashHandler->handlerUserPointer);

	/* Release lock. */
	deMutex_unlock(g_crashHandler->crashHandlerLock);

	return EXCEPTION_EXECUTE_HANDLER;
}

static void assertFailureCallback (const char* expr, const char* file, int line)
{
	/* Don't execute crash handler function if debugger is present. */
	if (IsDebuggerPresent())
	{
		DBGPRINT(("qpCrashHandler::assertFailureCallback(): debugger present\n"));
		return;
	}

	/* Acquire crash handler lock. */
	deMutex_lock(g_crashHandler->crashHandlerLock);

	/* Store info. */
	qpCrashInfo_set(&g_crashHandler->crashInfo, QP_CRASHTYPE_ASSERT, expr, file, line);
	g_crashHandler->crashAddress = 0;

	/* Handle the crash. */
	if (g_crashHandler->crashHandlerFunc != DE_NULL)
		g_crashHandler->crashHandlerFunc(g_crashHandler, g_crashHandler->handlerUserPointer);

	/* Release lock. */
	deMutex_unlock(g_crashHandler->crashHandlerLock);
}

qpCrashHandler* qpCrashHandler_create (qpCrashHandlerFunc handlerFunc, void* userPointer)
{
	/* Allocate & initialize. */
	qpCrashHandler* handler = (qpCrashHandler*)deCalloc(sizeof(qpCrashHandler));
	DBGPRINT(("qpCrashHandler::create() -- Win32\n"));
	if (!handler)
		return handler;

	DE_ASSERT(g_crashHandler == DE_NULL);

	handler->crashHandlerFunc	= handlerFunc ? handlerFunc : defaultCrashHandler;
	handler->handlerUserPointer	= userPointer;

	/* Create lock for crash handler. \note Has to be recursive or otherwise crash in assert failure causes deadlock. */
	{
		deMutexAttributes attr;
		attr.flags = DE_MUTEX_RECURSIVE;
		handler->crashHandlerLock = deMutex_create(&attr);

		if (!handler->crashHandlerLock)
		{
			deFree(handler);
			return DE_NULL;
		}
	}

	qpCrashInfo_init(&handler->crashInfo);
	handler->crashAddress		= 0;

	/* Unhandled exception filter. */
	handler->oldExceptionFilter = SetUnhandledExceptionFilter(unhandledExceptionFilter);

	/* Prevent nasty error dialog. */
	SetErrorMode(SEM_FAILCRITICALERRORS|SEM_NOGPFAULTERRORBOX);

	/* DE_ASSERT callback. */
	deSetAssertFailureCallback(assertFailureCallback);

	g_crashHandler = handler;
	return handler;
}

void qpCrashHandler_destroy (qpCrashHandler* handler)
{
	DBGPRINT(("qpCrashHandler::destroy()\n"));

	DE_ASSERT(g_crashHandler == handler);

	deSetAssertFailureCallback(DE_NULL);
	SetUnhandledExceptionFilter(handler->oldExceptionFilter);

	g_crashHandler = DE_NULL;
	deFree(handler);
}

enum
{
	MAX_NAME_LENGTH = 64
};

void qpCrashHandler_writeCrashInfo (qpCrashHandler* handler, qpWriteCrashInfoFunc writeInfo, void* userPtr)
{
	void*			addresses[32];
	HANDLE			process;

	/* Symbol info struct. */
	deUint8			symInfoStorage[sizeof(SYMBOL_INFO)+MAX_NAME_LENGTH];
	SYMBOL_INFO*	symInfo			= (SYMBOL_INFO*)symInfoStorage;

	DE_STATIC_ASSERT(sizeof(TCHAR) == sizeof(deUint8));

	/* Write basic info. */
	qpCrashInfo_write(&handler->crashInfo, writeInfo, userPtr);

	/* Acquire process handle and initialize symbols. */
	process = GetCurrentProcess();

	/* Write backtrace. */
	if (SymInitialize(process, NULL, TRUE))
	{
		int batchStart		= 0;
		int globalFrameNdx	= 0;

		/* Initialize symInfo. */
		deMemset(symInfo, 0, sizeof(symInfoStorage));
		symInfo->SizeOfStruct	= sizeof(SYMBOL_INFO);
		symInfo->MaxNameLen		= MAX_NAME_LENGTH;

		/* Print address and symbol where crash happened. */
		if (handler->crashAddress != 0)
		{
			BOOL symInfoOk = SymFromAddr(process, (DWORD64)handler->crashAddress, 0, symInfo);

			writeInfoFormat(writeInfo, userPtr, "  at %p %s%s\n", handler->crashAddress,
							symInfoOk ? symInfo->Name : "(unknown)",
							symInfoOk ? "()" : "");
		}

		writeInfo(userPtr, "Backtrace:\n");

		for (;;)
		{
			int curFrame;
			int numInBatch;

			/* Get one batch. */
			numInBatch = CaptureStackBackTrace(batchStart, DE_LENGTH_OF_ARRAY(addresses), addresses, NULL);

			for (curFrame = 0; curFrame < numInBatch; curFrame++)
			{
				BOOL symInfoOk = SymFromAddr(process, (DWORD64)addresses[curFrame], 0, symInfo);

				writeInfoFormat(writeInfo, userPtr, "  %2d: %p %s%s\n", globalFrameNdx++, addresses[curFrame],
								symInfoOk ? symInfo->Name : "(unknown)",
								symInfoOk ? "()" : "");
			}

			batchStart += numInBatch;

			/* Check if we hit end of stack trace. */
			if (numInBatch == 0 || numInBatch < DE_LENGTH_OF_ARRAY(addresses))
				break;
		}
	}
}

#else /* posix / generic implementation */

#if defined(QP_USE_SIGNAL_HANDLER)
#	include <signal.h>
#endif

#if defined(QP_USE_SIGNAL_HANDLER)

typedef struct SignalInfo_s
{
	int				signalNum;
	qpCrashType		type;
	const char*		name;
} SignalInfo;

static const SignalInfo s_signals[] =
{
	{ SIGABRT,		QP_CRASHTYPE_UNHANDLED_EXCEPTION,	"SIGABRT"	},
	{ SIGILL,		QP_CRASHTYPE_OTHER,					"SIGILL"	},
	{ SIGSEGV,		QP_CRASHTYPE_SEGMENTATION_FAULT,	"SIGSEGV"	},
	{ SIGFPE,		QP_CRASHTYPE_OTHER,					"SIGFPE"	},
	{ SIGBUS,		QP_CRASHTYPE_SEGMENTATION_FAULT,	"SIGBUS"	},
	{ SIGPIPE,		QP_CRASHTYPE_OTHER,					"SIGPIPE"	}
};

#endif /* QP_USE_SIGNAL_HANDLER */

struct qpCrashHandler_s
{
	qpCrashHandlerFunc		crashHandlerFunc;
	void*					handlerUserPointer;

	qpCrashInfo				crashInfo;
	int						crashSignal;

#if defined(QP_USE_SIGNAL_HANDLER)
	struct sigaction		oldHandlers[DE_LENGTH_OF_ARRAY(s_signals)];
#endif
};

qpCrashHandler* g_crashHandler = DE_NULL;

static void assertFailureCallback (const char* expr, const char* file, int line)
{
	/* Store info. */
	qpCrashInfo_set(&g_crashHandler->crashInfo, QP_CRASHTYPE_ASSERT, expr, file, line);

	/* Handle the crash. */
	if (g_crashHandler->crashHandlerFunc != DE_NULL)
		g_crashHandler->crashHandlerFunc(g_crashHandler, g_crashHandler->handlerUserPointer);
}

#if defined(QP_USE_SIGNAL_HANDLER)

static const SignalInfo* getSignalInfo (int sigNum)
{
	int ndx;
	for (ndx = 0; ndx < DE_LENGTH_OF_ARRAY(s_signals); ndx++)
	{
		if (s_signals[ndx].signalNum == sigNum)
			return &s_signals[ndx];
	}
	return DE_NULL;
}

static void signalHandler (int sigNum)
{
	const SignalInfo*	info	= getSignalInfo(sigNum);
	qpCrashType			type	= info ? info->type : QP_CRASHTYPE_OTHER;
	const char*			name	= info ? info->name : "Unknown signal";

	qpCrashInfo_set(&g_crashHandler->crashInfo, type, name, DE_NULL, 0);

	if (g_crashHandler->crashHandlerFunc != DE_NULL)
		g_crashHandler->crashHandlerFunc(g_crashHandler, g_crashHandler->handlerUserPointer);
}

#endif /* QP_USE_SIGNAL_HANDLER */

qpCrashHandler* qpCrashHandler_create (qpCrashHandlerFunc handlerFunc, void* userPointer)
{
	/* Allocate & initialize. */
	qpCrashHandler* handler = (qpCrashHandler*)deCalloc(sizeof(qpCrashHandler));
	DBGPRINT(("qpCrashHandler::create()\n"));
	if (!handler)
		return handler;

	DE_ASSERT(g_crashHandler == DE_NULL);

	handler->crashHandlerFunc	= handlerFunc ? handlerFunc : defaultCrashHandler;
	handler->handlerUserPointer	= userPointer;

	qpCrashInfo_init(&handler->crashInfo);

	g_crashHandler = handler;

	/* DE_ASSERT callback. */
	deSetAssertFailureCallback(assertFailureCallback);

#if defined(QP_USE_SIGNAL_HANDLER)
	/* Register signal handlers. */
	{
		struct sigaction	action;
		int					sigNdx;

		sigemptyset(&action.sa_mask);
		action.sa_handler	= signalHandler;
		action.sa_flags		= 0;

		for (sigNdx = 0; sigNdx < DE_LENGTH_OF_ARRAY(s_signals); sigNdx++)
			sigaction(s_signals[sigNdx].signalNum, &action, &handler->oldHandlers[sigNdx]);
	}
#endif

	return handler;
}

void qpCrashHandler_destroy (qpCrashHandler* handler)
{
	DBGPRINT(("qpCrashHandler::destroy()\n"));

	DE_ASSERT(g_crashHandler == handler);

	deSetAssertFailureCallback(DE_NULL);

#if defined(QP_USE_SIGNAL_HANDLER)
	/* Restore old handlers. */
	{
		int sigNdx;
		for (sigNdx = 0; sigNdx < DE_LENGTH_OF_ARRAY(s_signals); sigNdx++)
			sigaction(s_signals[sigNdx].signalNum, &handler->oldHandlers[sigNdx], DE_NULL);
	}
#endif

	g_crashHandler = DE_NULL;

	deFree(handler);
}

#if (DE_PTR_SIZE  == 8)
#	define PTR_FMT "0x%016"
#elif (DE_PTR_SIZE  == 4)
#	define PTR_FMT "0x%08"
#else
#	error Unknwon DE_PTR_SIZE
#endif

void qpCrashHandler_writeCrashInfo (qpCrashHandler* crashHandler, qpWriteCrashInfoFunc writeInfo, void* userPtr)
{
	qpCrashInfo_write(&crashHandler->crashInfo, writeInfo, userPtr);

#if (DE_OS == DE_OS_UNIX)
	{
		char	tmpFileName[]	= "backtrace-XXXXXX";
		int		tmpFile			= mkstemp(tmpFileName);

		if (tmpFile == -1)
		{
			writeInfoFormat(writeInfo, userPtr, "Failed to create tmpfile '%s' for the backtrace %s.", tmpFileName, strerror(errno));
			return;
		}
		else
		{
			void*	symbols[32];
			int		symbolCount;
			int		symbolNdx;

			/* Remove file from filesystem. */
			remove(tmpFileName);

			symbolCount = backtrace(symbols, DE_LENGTH_OF_ARRAY(symbols));
			backtrace_symbols_fd(symbols, symbolCount, tmpFile);

			if (lseek(tmpFile, 0, SEEK_SET) < 0)
			{
				writeInfoFormat(writeInfo, userPtr, "Failed to seek to the beginning of the trace file %s.", strerror(errno));
				close(tmpFile);
				return;
			}

			for (symbolNdx = 0; symbolNdx < symbolCount; symbolNdx++)
			{
				char	nameBuffer[256];
				size_t	symbolNameLength = 0;
				char	c;

				{
					const int ret = snprintf(nameBuffer, DE_LENGTH_OF_ARRAY(nameBuffer), PTR_FMT  PRIXPTR " : ", (uintptr_t)symbols[symbolNdx]);

					if (ret < 0)
					{
						writeInfoFormat(writeInfo, userPtr, "Failed to print symbol pointer.");
						symbolNameLength = 0;
					}
					else if (ret >= DE_LENGTH_OF_ARRAY(nameBuffer))
					{
						symbolNameLength = DE_LENGTH_OF_ARRAY(nameBuffer) - 1;
						nameBuffer[DE_LENGTH_OF_ARRAY(nameBuffer) - 1] = '\0';
					}
					else
						symbolNameLength = ret;
				}

				for (;;)
				{
					if (read(tmpFile, &c, 1) == 1)
					{
						if (c == '\n')
						{
							/* Flush nameBuffer and move to next symbol. */
							nameBuffer[symbolNameLength] = '\0';
							writeInfo(userPtr, nameBuffer);
							break;
						}
						else
						{
							/* Add character to buffer if there is still space left. */
							if (symbolNameLength+1 < DE_LENGTH_OF_ARRAY(nameBuffer))
							{
								nameBuffer[symbolNameLength] = c;
								symbolNameLength++;
							}
						}
					}
					else
					{
						/* Flush nameBuffer. */
						nameBuffer[symbolNameLength] = '\0';
						writeInfo(userPtr, nameBuffer);

						/* Temp file ended unexpectedly? */
						writeInfoFormat(writeInfo, userPtr, "Unexpected EOF reading backtrace file '%s'", tmpFileName);
						close(tmpFile);
						tmpFile = -1;

						break;
					}
				}

				if (tmpFile == -1)
					break;
			}

			if (tmpFile != -1)
				close(tmpFile);
		}
	}
#endif
}

#endif /* generic */