//===-- MIDriverMain.cpp ----------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

//++
// File:		MIDriverMain.cpp
//
// Overview:	Defines the entry point for the console application.
//				The MI application (project name MI) runs in two modes:
//				An LLDB native driver mode where it acts no different from the LLDB driver.
//				The other mode is the MI when it finds on the command line
//				the --interpreter option. Command line argument --help on its own will give
//				help for the LLDB driver. If entered with --interpreter then MI help will
//				provided.
//				To implement new MI commands derive a new command class from the command base 
//				class. To enable the new command for interpretation add the new command class
//				to the command factory. The files of relevance are:
//					MICmdCommands.cpp
//					MICmdBase.h / .cpp
//					MICmdCmd.h / .cpp
// Versions:	1.0.0.1		First version from scratch 28/1/2014 to 28/3/2014. MI not complete.
//				1.0.0.2		First deliverable to client 7/3/2014. MI not complete.
//				1.0.0.3		Code refactor tidy. Release to community for evaluation 17/5/2014. MI not complete.
//				1.0.0.4		Post release to community for evaluation 17/5/2014. MI not complete.
//				1.0.0.5		Second deliverable to client 16/6/2014.
//				1.0.0.6		Post release of second deliverable to client 16/6/2014.
//				See MIreadme.txt for list of MI commands implemented.
//
// Environment:	Compilers:	Visual C++ 12.
//							gcc (Ubuntu/Linaro 4.8.1-10ubuntu9) 4.8.1
//				Libraries:	See MIReadme.txt. 
//
// Copyright:	None.
//--

#if defined( _MSC_VER )
	#define _INC_SIGNAL // Stop window's signal.h being included - CODETAG_IOR_SIGNALS
#endif // _MSC_VER

// Third party headers:
#include <stdio.h>
#include <lldb/API/SBHostOS.h>

// In house headers:
#include "MICmnConfig.h"
#include "Platform.h"	// Define signals - CODETAG_IOR_SIGNALS
#include "Driver.h"
#include "MIDriverMgr.h"
#include "MIDriver.h"
#include "MICmnResources.h"
#include "MICmnStreamStdin.h"
#include "MIUtilDebug.h"
#include "MICmnLog.h"

#if MICONFIG_COMPILE_MIDRIVER_VERSION

#if defined( _MSC_VER )
#pragma warning( once : 4530 ) // Warning C4530: C++ exception handler used, but unwind semantics are not enabled. Specify /EHsc
#endif // _MSC_VER

// ToDo: Reevaluate if this function needs to be implemented like the UNIX equivalent
// CODETAG_IOR_SIGNALS
//++ ------------------------------------------------------------------------------------
// Details:	The SIGWINCH signal is sent to a process when its controlling terminal 
//			changes its size (a window change).
// Type:	Function.
// Args:	vSigno	- (R) Signal number.				  	
// Return:	None.
// Throws:	None.
//--
void sigwinch_handler( int vSigno )
{
	MIunused( vSigno );

	struct winsize window_size;
	if( ::isatty( STDIN_FILENO ) && ::ioctl( STDIN_FILENO, TIOCGWINSZ, &window_size ) == 0 )
	{
		CMIDriverMgr & rDriverMgr = CMIDriverMgr::Instance();
		if( window_size.ws_col > 0 )
		{
 			rDriverMgr.DriverResizeWindow( (uint32_t) window_size.ws_col );
		}
	}

	CMICmnLog::Instance().WriteLog( CMIUtilString::Format( MIRSRC( IDS_PROCESS_SIGNAL_RECEIVED ), "SIGWINCH", vSigno ) );
}

// CODETAG_IOR_SIGNALS
//++ ------------------------------------------------------------------------------------
// Details:	The SIGINT signal is sent to a process by its controlling terminal when a 
//			user wishes to interrupt the process. This is typically initiated by pressing 
//			Control-C, but on some systems, the "delete" character or "break" key can be 
//			used.
//			Be aware this function may be called on another thread besides the main thread.
// Type:	Function.
// Args:	vSigno	- (R) Signal number.				  	
// Return:	None.
// Throws:	None.
//--
void sigint_handler( int vSigno )
{
	static bool g_interrupt_sent = false;
	CMIDriverMgr & rDriverMgr = CMIDriverMgr::Instance();
	lldb::SBDebugger * pDebugger = rDriverMgr.DriverGetTheDebugger();
	if( pDebugger != nullptr )
	{
		if( !g_interrupt_sent )
		{
			g_interrupt_sent = true;
			pDebugger->DispatchInputInterrupt();
			g_interrupt_sent = false;
		}
	}

	CMICmnLog::Instance().WriteLog( CMIUtilString::Format( MIRSRC( IDS_PROCESS_SIGNAL_RECEIVED ), "SIGINT", vSigno ) );

	// CODETAG_DEBUG_SESSION_RUNNING_PROG_RECEIVED_SIGINT_PAUSE_PROGRAM
	// Signal MI to shutdown or halt a running debug session
	CMICmnStreamStdin::Instance().SetCtrlCHit();
}

// ToDo: Reevaluate if this function needs to be implemented like the UNIX equivalent
// CODETAG_IOR_SIGNALS
//++ ------------------------------------------------------------------------------------
// Details:	The SIGTSTP signal is sent to a process by its controlling terminal to 
//			request it to stop temporarily. It is commonly initiated by the user pressing 
//			Control-Z. Unlike SIGSTOP, the process can register a signal handler for or 
//			ignore the signal.
//			*** The function does not behave ATM like the UNIX equivalent ***
// Type:	Function.
// Args:	vSigno	- (R) Signal number.				  	
// Return:	None.
// Throws:	None.
//--
void sigtstp_handler( int vSigno )
{
	CMIDriverMgr & rDriverMgr = CMIDriverMgr::Instance();
	lldb::SBDebugger * pDebugger = rDriverMgr.DriverGetTheDebugger();
	if( pDebugger != nullptr )
	{
		pDebugger->SaveInputTerminalState();
	}

	CMICmnLog::Instance().WriteLog( CMIUtilString::Format( MIRSRC( IDS_PROCESS_SIGNAL_RECEIVED ), "SIGTSTP", vSigno ) );

	// Signal MI to shutdown
	CMICmnStreamStdin::Instance().SetCtrlCHit();
}

// ToDo: Reevaluate if this function needs to be implemented like the UNIX equivalent
// CODETAG_IOR_SIGNALS
//++ ------------------------------------------------------------------------------------
// Details:	The SIGCONT signal instructs the operating system to continue (restart) a 
//			process previously paused by the SIGSTOP or SIGTSTP signal. One important use 
//			of this signal is in job control in the UNIX shell.
//			*** The function does not behave ATM like the UNIX equivalent ***
// Type:	Function.
// Args:	vSigno	- (R) Signal number.			  	
// Return:	None.
// Throws:	None.
//--
void sigcont_handler( int vSigno )
{
	CMIDriverMgr & rDriverMgr = CMIDriverMgr::Instance();
	lldb::SBDebugger * pDebugger = rDriverMgr.DriverGetTheDebugger();
	if( pDebugger != nullptr )
	{
		pDebugger->RestoreInputTerminalState();
	}

	CMICmnLog::Instance().WriteLog( CMIUtilString::Format( MIRSRC( IDS_PROCESS_SIGNAL_RECEIVED ), "SIGCONT", vSigno ) );

	// Signal MI to shutdown
	CMICmnStreamStdin::Instance().SetCtrlCHit();
}

//++ ------------------------------------------------------------------------------------
// Details:	Init the MI driver system. Initialize the whole driver system which includes
//			both the original LLDB driver and the MI driver.
// Type:	Function.
// Args:	None.			  	
// Return:	MIstatus::success - Functional succeeded.
//			MIstatus::failure - Functional failed.
// Throws:	None.
//--
bool DriverSystemInit( void )
{
	bool bOk = MIstatus::success;

#if MICONFIG_COMPILE_MIDRIVER_WITH_LLDBDRIVER
	Driver * pDriver = Driver::CreateSelf();
	if( pDriver == nullptr )
		return MIstatus::failure;
#endif // MICONFIG_COMPILE_MIDRIVER_WITH_LLDBDRIVER

	CMIDriver & rMIDriver = CMIDriver::Instance();
	CMIDriverMgr & rDriverMgr = CMIDriverMgr::Instance();
	bOk = rDriverMgr.Initialize();

	// Register MIDriver first as it needs to initialize and be ready
	// for the Driver to get information from MIDriver when it initializes
	// (LLDB Driver is registered with the Driver Manager in MI's Initialize())
	bOk = bOk && rDriverMgr.RegisterDriver( rMIDriver, "MIDriver" );	// Will be main driver

	return bOk;
}

//++ ------------------------------------------------------------------------------------
// Details:	Shutdown the debugger system. Release / terminate resources external to
//			specifically the MI driver.
// Type:	Function.
// Args:	vbAppExitOk	- (R) True = No problems, false = App exiting with problems (investigate!).			  	
// Return:	MIstatus::success - Functional succeeded.
//			MIstatus::failure - Functional failed.
// Throws:	None.
//--
bool DriverSystemShutdown( const bool vbAppExitOk )
{
	bool bOk = MIstatus::success;

	// *** Order is important here ***
	CMIDriverMgr::Instance().Shutdown();

#if MICONFIG_COMPILE_MIDRIVER_WITH_LLDBDRIVER
	delete g_driver;
	g_driver = nullptr;	
#endif // MICONFIG_COMPILE_MIDRIVER_WITH_LLDBDRIVER

	return bOk;
}

#else
void
sigwinch_handler (int signo)
{
    struct winsize window_size;
    if (isatty (STDIN_FILENO)
        && ::ioctl (STDIN_FILENO, TIOCGWINSZ, &window_size) == 0)
    {
        if ((window_size.ws_col > 0) && g_driver != NULL)
        {
            g_driver->ResizeWindow (window_size.ws_col);
        }
    }
}

void
sigint_handler (int signo)
{
	static bool g_interrupt_sent = false;
    if (g_driver)
	{
		if (!g_interrupt_sent)
		{
			g_interrupt_sent = true;
        	g_driver->GetDebugger().DispatchInputInterrupt();
			g_interrupt_sent = false;
			return;
		}
	}
    
	exit (signo);
}

void
sigtstp_handler (int signo)
{
    g_driver->GetDebugger().SaveInputTerminalState();
    signal (signo, SIG_DFL);
    kill (getpid(), signo);
    signal (signo, sigtstp_handler);
}

void
sigcont_handler (int signo)
{
    g_driver->GetDebugger().RestoreInputTerminalState();
    signal (signo, SIG_DFL);
    kill (getpid(), signo);
    signal (signo, sigcont_handler);
}
#endif // #if MICONFIG_COMPILE_MIDRIVER_VERSION

//++ ------------------------------------------------------------------------------------
// Details:	MI's application start point of execution. The applicaton runs in two modes.
//			An LLDB native driver mode where it acts no different from the LLDB driver.
//			The other mode is the MI when it finds on the command line
//			the --interpreter option. Command line argument --help on its own will give
//			help for the LLDB driver. If entered with --interpreter then application
//			help will provided.
// Type:	Method.
// Args:	argc	- (R) An integer that contains the count of arguments that follow in 
//						  argv. The argc parameter is always greater than or equal to 1.
//			argv	- (R) An array of null-terminated strings representing command-line 
//						  arguments entered by the user of the program. By convention, 
//						  argv[0] is the command with which the program is invoked.
// Return:	int -  0 =	 Normal exit, program success.
//				  >0	= Program success with status	i.e. Control-C signal status
//				  <0	= Program failed.
//				-1		= Program failed reason not specified here, see MI log file.
//				-1000	= Program failed did not initailize successfully.
// Throws:	None.
//--
#if MICONFIG_COMPILE_MIDRIVER_VERSION
int main( int argc, char const *argv[] )
{
#if MICONFIG_DEBUG_SHOW_ATTACH_DBG_DLG
#ifdef _WIN32
	CMIUtilDebug::ShowDlgWaitForDbgAttach();
#else
	CMIUtilDebug::WaitForDbgAttachInfinteLoop();
#endif //  _WIN32
#endif // MICONFIG_DEBUG_SHOW_ATTACH_DBG_DLG

	// *** Order is important here ***
	bool bOk = DriverSystemInit();
	if( !bOk )
	{
		DriverSystemShutdown( bOk );
		return -1000;
	}
		
	// CODETAG_IOR_SIGNALS
	signal( SIGPIPE, SIG_IGN );
	signal( SIGWINCH, sigwinch_handler );
	signal( SIGINT, sigint_handler );
	signal( SIGTSTP, sigtstp_handler );
	signal( SIGCONT, sigcont_handler );
		
	bool bExiting = false;
	CMIDriverMgr & rDriverMgr = CMIDriverMgr::Instance();
	bOk = bOk && rDriverMgr.ParseArgs( argc, argv, bExiting );
	if( bOk && !bExiting )
		bOk = rDriverMgr.DriverParseArgs( argc, argv, stdout, bExiting );
	if( bOk && !bExiting )
		bOk = rDriverMgr.DriverMainLoop();
	
	// Logger and other resources shutdown now
	DriverSystemShutdown( bOk );

	const int appResult = bOk ? 0 : -1;

	return appResult;
}
#else // Operate the lldb Driver only version of the code
int main(int argc, char const *argv[], char *envp[])
{
	MIunused( envp );
	using namespace lldb;
	SBDebugger::Initialize();

	SBHostOS::ThreadCreated ("<lldb.driver.main-thread>");

	signal (SIGPIPE, SIG_IGN);
	signal (SIGWINCH, sigwinch_handler);
	signal (SIGINT, sigint_handler);
	signal (SIGTSTP, sigtstp_handler);
	signal (SIGCONT, sigcont_handler);

	// Create a scope for driver so that the driver object will destroy itself
	// before SBDebugger::Terminate() is called.
	{
		Driver driver;

		bool exiting = false;
		SBError error (driver.ParseArgs (argc, argv, stdout, exiting));
		if (error.Fail())
		{
			const char *error_cstr = error.GetCString ();
			if (error_cstr)
				::fprintf (stderr, "error: %s\n", error_cstr);
		}
		else if (!exiting)
		{
			driver.MainLoop();
		}
	}

	SBDebugger::Terminate();
	return 0;
}
#endif // MICONFIG_COMPILE_MIDRIVER_VERSION