fceugx/source/fceultra/debug.cpp

/// \file 
/// \brief Implements core debugging facilities

#include <stdlib.h>
#include <string.h>

#include "types.h"
#include "x6502.h"
#include "fceu.h"
#include "cart.h"
#include "ines.h"
#include "debug.h"
#include "driver.h"
#include "ppu.h"

#include "x6502abbrev.h"

int vblankScanLines = 0;	//Used to calculate scanlines 240-261 (vblank)
int vblankPixel = 0;		//Used to calculate the pixels in vblank
int offsetStringToInt(unsigned int type, const char* offsetBuffer)
{
	int offset = 0;

	if (sscanf(offsetBuffer,"%4X",&offset) == EOF)
	{
		return -1;
	}

	if (type & BT_P)
	{
		return offset & 0x3FFF;
	}
	else if (type & BT_S)
	{
		return offset & 0x00FF;
	}
	else // BT_C
	{
		if (GameInfo->type == GIT_NSF) { //NSF Breakpoint keywords
			if (strcmp(offsetBuffer,"LOAD") == 0) return (NSFHeader.LoadAddressLow | (NSFHeader.LoadAddressHigh<<8));
			if (strcmp(offsetBuffer,"INIT") == 0) return (NSFHeader.InitAddressLow | (NSFHeader.InitAddressHigh<<8));
			if (strcmp(offsetBuffer,"PLAY") == 0) return (NSFHeader.PlayAddressLow | (NSFHeader.PlayAddressHigh<<8));
		}
		else if (GameInfo->type == GIT_FDS) { //FDS Breakpoint keywords
			if (strcmp(offsetBuffer,"NMI1") == 0) return (GetMem(0xDFF6) | (GetMem(0xDFF7)<<8));
			if (strcmp(offsetBuffer,"NMI2") == 0) return (GetMem(0xDFF8) | (GetMem(0xDFF9)<<8));
			if (strcmp(offsetBuffer,"NMI3") == 0) return (GetMem(0xDFFA) | (GetMem(0xDFFB)<<8));
			if (strcmp(offsetBuffer,"RST") == 0) return (GetMem(0xDFFC) | (GetMem(0xDFFD)<<8));
			if ((strcmp(offsetBuffer,"IRQ") == 0) || (strcmp(offsetBuffer,"BRK") == 0)) return (GetMem(0xDFFE) | (GetMem(0xDFFF)<<8));
		}
		else { //NES Breakpoint keywords
			if ((strcmp(offsetBuffer,"NMI") == 0) || (strcmp(offsetBuffer,"VBL") == 0)) return (GetMem(0xFFFA) | (GetMem(0xFFFB)<<8));
			if (strcmp(offsetBuffer,"RST") == 0) return (GetMem(0xFFFC) | (GetMem(0xFFFD)<<8));
			if ((strcmp(offsetBuffer,"IRQ") == 0) || (strcmp(offsetBuffer,"BRK") == 0)) return (GetMem(0xFFFE) | (GetMem(0xFFFF)<<8));
		}
	}

	return offset;
}

// Returns the value of a given type or register

int getValue(int type)
{
	switch (type)
	{
		case 'A': return _A;
		case 'X': return _X;
		case 'Y': return _Y;
		case 'N': return _P & N_FLAG ? 1 : 0;
		case 'V': return _P & V_FLAG ? 1 : 0;
		case 'U': return _P & U_FLAG ? 1 : 0;
		case 'B': return _P & B_FLAG ? 1 : 0;
		case 'D': return _P & D_FLAG ? 1 : 0;
		case 'I': return _P & I_FLAG ? 1 : 0;
		case 'Z': return _P & Z_FLAG ? 1 : 0;
		case 'C': return _P & C_FLAG ? 1 : 0;
		case 'P': return _PC;
	}

	return 0;
}


/**
* Checks whether a breakpoint condition is syntactically valid
* and creates a breakpoint condition object if everything's OK.
*
* @param condition Condition to parse
* @param num Number of the breakpoint in the BP list the condition belongs to
* @return 0 in case of an error; 2 if everything went fine
**/
int checkCondition(const char* condition, int num)
{
	const char* b = condition;
	
	// Check if the condition isn't just all spaces.
	
	int onlySpaces = 1;
	
	while (*b)
	{
		if (*b != ' ')
		{
			onlySpaces = 0;
			break;
		}
		
		++b;
	}
	
	// Remove the old breakpoint condition before
	// adding a new condition.
	
	if (watchpoint[num].cond)
	{
		freeTree(watchpoint[num].cond);
		free(watchpoint[num].condText);
		
		watchpoint[num].cond = 0;
		watchpoint[num].condText = 0;
	}
			
	// If there's an actual condition create the BP condition object now
	
	if (*condition && !onlySpaces)
	{
		Condition* c = generateCondition(condition);
		
		// If the creation of the BP condition object was succesful
		// the condition is apparently valid. It can be added to the
		// breakpoint now.
		
		if (c)
		{
			watchpoint[num].cond = c;
			watchpoint[num].condText = (char*)malloc(strlen(condition) + 1);
            if (!watchpoint[num].condText)
                return 0;
			strcpy(watchpoint[num].condText, condition);
		}
		else
		{
			watchpoint[num].cond = 0;
		}
		
		return watchpoint[num].cond == 0 ? 2 : 0;
	}
	else
	{
		return 0;
	}
}

/**
* Adds a new breakpoint.
*
* @param hwndDlg Handle of the debugger window
* @param num Number of the breakpoint
* @param 
**/
unsigned int NewBreak(const char* name, int start, int end, unsigned int type, const char* condition, unsigned int num, bool enable)
{
	// Finally add breakpoint to the list
	watchpoint[num].address = start;
	watchpoint[num].endaddress = 0;

	// Optional end address found
	if (end != -1)
	{
		watchpoint[num].endaddress = end;
	}

	// Get the breakpoint flags
	watchpoint[num].flags = 0;
	if (enable) watchpoint[num].flags|=WP_E;
	if (type & WP_R) watchpoint[num].flags|=WP_R;
	if (type & WP_F) watchpoint[num].flags|=WP_F;
	if (type & WP_W) watchpoint[num].flags|=WP_W;
	if (type & WP_X) watchpoint[num].flags|=WP_X;
	if (type & BT_P) {
		watchpoint[num].flags|=BT_P;
		watchpoint[num].flags&=~WP_X; //disable execute flag!
	}
	if (type & BT_S) {
		watchpoint[num].flags|=BT_S;
		watchpoint[num].flags&=~WP_X; //disable execute flag!
	}

	if (watchpoint[num].desc)
		free(watchpoint[num].desc);

	watchpoint[num].desc = (char*)malloc(strlen(name) + 1);
	strcpy(watchpoint[num].desc, name);
	
	return checkCondition(condition, num);
}

int GetPRGAddress(int A){
	int result;
	if((A < 0x8000) || (A > 0xFFFF))return -1;
	result = &Page[A>>11][A]-PRGptr[0];
	if((result > (int)PRGsize[0]) || (result < 0))return -1;
	else return result;
}

/**
* Returns the bank for a given offset.
* Technically speaking this function does not calculate the actual bank
* where the offset resides but the 0x4000 bytes large chunk of the ROM of the offset.
* 
* @param offs The offset
* @return The bank of that offset or -1 if the offset is not part of the ROM.
**/
int getBank(int offs)
{
	//NSF data is easy to overflow the return on.
	//Anything over FFFFF will kill it.


	//GetNesFileAddress doesn't work well with Unif files
	int addr = GetNesFileAddress(offs)-16;

	if (GameInfo && GameInfo->type==GIT_NSF) {
	return addr != -1 ? addr / 0x1000 : -1;
	}
	return addr != -1 ? addr / 0x4000 : -1;
}

int GetNesFileAddress(int A){
	unsigned int result;
	if((A < 0x8000) || (A > 0xFFFF))return -1;
	result = &Page[A>>11][A]-PRGptr[0];
	if((result > PRGsize[0]) || (result < 0))return -1;
	else return result+16; //16 bytes for the header remember
}

int GetRomAddress(int A){
	int i;
	uint8 *p = GetNesPRGPointer(A-=16);
	for(i = 16;i < 32;i++){
		if((&Page[i][i<<11] <= p) && (&Page[i][(i+1)<<11] > p))break;
	}
	if(i == 32)return -1; //not found

	return (i<<11) + (p-&Page[i][i<<11]);
}

uint8 *GetNesPRGPointer(int A){
	return PRGptr[0]+A;
}

uint8 *GetNesCHRPointer(int A){
	return CHRptr[0]+A;
}

uint8 GetMem(uint16 A) {
	if ((A >= 0x2000) && (A < 0x4000)) {
		switch (A&7) {
			case 0: return PPU[0];
			case 1: return PPU[1];
			case 2: return PPU[2]|(PPUGenLatch&0x1F);
			case 3: return PPU[3];
			case 4: return SPRAM[PPU[3]];
			case 5: return XOffset;
			case 6: return RefreshAddr&0xFF;
			case 7: return VRAMBuffer;
		}
	}
	else if ((A >= 0x4000) && (A < 0x6000)) return 0xFF; //fix me
	if (GameInfo) return ARead[A](A);					 //adelikat: 11/17/09: Prevent crash if this is called with no game loaded.
	else return 0;
}

uint8 GetPPUMem(uint8 A) {
	uint16 tmp=RefreshAddr&0x3FFF;

	if (tmp<0x2000) return VPage[tmp>>10][tmp];
	if (tmp>=0x3F00) return PALRAM[tmp&0x1F];
	return vnapage[(tmp>>10)&0x3][tmp&0x3FF];
}

//---------------------

// Evaluates a condition
int evaluate(Condition* c)
{
	int f = 0;

	int value1, value2;

	if (c->lhs)
	{
		value1 = evaluate(c->lhs);
	}
	else
	{
		switch(c->type1)
		{
			case TYPE_ADDR: // This is intended to not break, and use the TYPE_NUM code
			case TYPE_NUM: value1 = c->value1; break;
			default: value1 = getValue(c->value1); break;
		}
	}

	switch(c->type1)
	{
		case TYPE_ADDR: value1 = GetMem(value1); break;
		case TYPE_BANK: value1 = getBank(_PC); break;
	}

	f = value1;

	if (c->op)
	{
		if (c->rhs)
		{
			value2 = evaluate(c->rhs);
		}
		else
		{
			switch(c->type2)
			{
				case TYPE_ADDR: // This is intended to not break, and use the TYPE_NUM code
				case TYPE_NUM: value2 = c->value2; break;
				default: value2 = getValue(c->type2); break;
			}
		}

	switch(c->type2)
	{
		case TYPE_ADDR: value2 = GetMem(value2); break;
		case TYPE_BANK: value2 = getBank(_PC); break;
	}

		switch (c->op)
		{
			case OP_EQ: f = value1 == value2; break;
			case OP_NE: f = value1 != value2; break;
			case OP_GE: f = value1 >= value2; break;
			case OP_LE: f = value1 <= value2; break;
			case OP_G: f = value1 > value2; break;
			case OP_L: f = value1 < value2; break;
			case OP_MULT: f = value1 * value2; break;
			case OP_DIV: f = value1 / value2; break;
			case OP_PLUS: f = value1 + value2; break;
			case OP_MINUS: f = value1 - value2; break;
			case OP_OR: f = value1 || value2; break;
			case OP_AND: f = value1 && value2; break;
		}
	}

	return f;
}

int condition(watchpointinfo* wp)
{
	return wp->cond == 0 || evaluate(wp->cond);
}


//---------------------

volatile int codecount, datacount, undefinedcount;
unsigned char *cdloggerdata;
char *cdlogfilename;
static int indirectnext;

int debug_loggingCD;

//called by the cpu to perform logging if CDLogging is enabled
void LogCDVectors(int which){
	int j;
	j = GetPRGAddress(which);
	if(j == -1){
		return;
	}

	if(!(cdloggerdata[j] & 2)){
		cdloggerdata[j] |= 0x0E; // we're in the last bank and recording it as data so 0x1110 or 0xE should be what we need
		datacount++;
		if(!(cdloggerdata[j] & 1))undefinedcount--;
	}
	j++;
	
	if(!(cdloggerdata[j] & 2)){
		cdloggerdata[j] |= 0x0E;
		datacount++;
		if(!(cdloggerdata[j] & 1))undefinedcount--;
	}
}

void LogCDData(){
	int i, j;
	uint16 A = 0; 
	uint8 opcode[3] = {0}, memop = 0;

	j = GetPRGAddress(_PC);

	if(j != -1) {
		opcode[0] = GetMem(_PC);
		switch (opsize[opcode[0]]) {
			case 2:
				opcode[1] = GetMem(_PC + 1);
				break;
			case 3:
				opcode[1] = GetMem(_PC + 1);
				opcode[2] = GetMem(_PC + 2);
				break;
		}
	
		for (i = 0; i < opsize[opcode[0]]; i++){
			if(cdloggerdata[j+i] & 1)continue; //this has been logged so skip
			cdloggerdata[j+i] |= 1;
			cdloggerdata[j+i] |=((_PC+i)>>11)&0x0c;
			if(indirectnext)cdloggerdata[j+i] |= 0x10;
			codecount++; 
			if(!(cdloggerdata[j+i] & 2))undefinedcount--;
		}

		//log instruction jumped to in an indirect jump
		if(opcode[0] == 0x6c) indirectnext = 1; else indirectnext = 0;

		switch (optype[opcode[0]]) {
			case 0: break;
			case 1:
				A = (opcode[1]+_X) & 0xFF;
				A = GetMem(A) | (GetMem(A+1)<<8);
				memop = 0x20;
				break;
			case 2: A = opcode[1]; break;
			case 3: A = opcode[1] | opcode[2]<<8; break;
			case 4:
				A = (GetMem(opcode[1]) | (GetMem(opcode[1]+1)<<8))+_Y;
				memop = 0x20;
				break;
			case 5: A = opcode[1]+_X; break;
			case 6: A = (opcode[1] | (opcode[2]<<8))+_Y; break;
			case 7: A = (opcode[1] | (opcode[2]<<8))+_X; break;
			case 8: A = opcode[1]+_Y; break;
		}

		if((j = GetPRGAddress(A)) != -1) {
			if(!(cdloggerdata[j] & 2)) {
				cdloggerdata[j] |= 2;
				cdloggerdata[j] |=(A>>11)&0x0c;
				cdloggerdata[j] |= memop;
				datacount++; 
				if(!(cdloggerdata[j] & 1))undefinedcount--;
			}
		}
	}
}

//-----------debugger stuff

watchpointinfo watchpoint[65]; //64 watchpoints, + 1 reserved for step over
int iaPC;
uint32 iapoffset; //mbg merge 7/18/06 changed from int
int u; //deleteme
int skipdebug; //deleteme
int numWPs; 

static DebuggerState dbgstate;

DebuggerState &FCEUI_Debugger() { return dbgstate; }

void BreakHit(bool force = false) {

	if(!force) {
		
		//check to see whether we fall in any forbid zone
		for (int i = 0; i < numWPs; i++) {
			watchpointinfo& wp = watchpoint[i];
			if(!(wp.flags & WP_F) || !(wp.flags & WP_E))
				continue;

			if (condition(&wp))
			{
				if (wp.endaddress) {
					if( (wp.address <= _PC) && (wp.endaddress >= _PC) )
						return;	//forbid
				} else {
					if(wp.address == _PC)
						return; //forbid
				}
			}
		}
	}

	FCEUI_SetEmulationPaused(1); //mbg merge 7/19/06 changed to use EmulationPaused()
	
	//MBG TODO - was this commented out before the gnu refactoring?
	//if((!logtofile) && (logging))PauseLoggingSequence();
	
	FCEUD_DebugBreakpoint();
}

uint8 StackAddrBackup = X.S;
uint16 StackNextIgnorePC = 0xFFFF;

///fires a breakpoint
void breakpoint() {
	int i,j;
	uint16 A=0;
	uint8 brk_type,opcode[3] = {0};
	uint8 stackop=0;
	uint8 stackopstartaddr,stackopendaddr;

	//inspect the current opcode
	opcode[0] = GetMem(_PC);

	//if the current instruction is bad, and we are breaking on bad opcodes, then hit the breakpoint
	if(dbgstate.badopbreak && (opsize[opcode[0]] == 0)) BreakHit(true);

	//if we're stepping out, track the nest level
	if (dbgstate.stepout) {
		if (opcode[0] == 0x20) dbgstate.jsrcount++;
		else if (opcode[0] == 0x60) {
			if (dbgstate.jsrcount) dbgstate.jsrcount--;
			else {
				dbgstate.stepout = false;
				dbgstate.step = true;
				return;
			}
		}
	}

	//if we're stepping, then we'll always want to break
	if (dbgstate.step) {
		dbgstate.step = false;
		BreakHit(true);
		return;
	}
	//if we're running for a scanline, we want to check if we've hit the cycle limit
	
	if (dbgstate.runline) {
		uint64 ts = timestampbase;
		ts+=timestamp;
		int diff = dbgstate.runline_end_time-ts;
		if (diff<=0)
		{
			dbgstate.runline=false;
			BreakHit(true);
			return;
		}
	}
	//check the step over address and break if we've hit it
	if ((watchpoint[64].address == _PC) && (watchpoint[64].flags)) {
		watchpoint[64].address = 0;
		watchpoint[64].flags = 0;
		BreakHit(true);
		return;
	}

	for (i = 1; i < opsize[opcode[0]]; i++) opcode[i] = GetMem(_PC+i);
	brk_type = opbrktype[opcode[0]] | WP_X;
	switch (optype[opcode[0]]) {
		case 0: /*A = _PC;*/ break;
		case 1:
			A = (opcode[1]+_X) & 0xFF;
			A = GetMem(A) | (GetMem(A+1))<<8;
			break;
		case 2: A = opcode[1]; break;
		case 3: A = opcode[1] | opcode[2]<<8; break;
		case 4: A = (GetMem(opcode[1]) | (GetMem(opcode[1]+1))<<8)+_Y; break;
		case 5: A = opcode[1]+_X; break;
		case 6: A = (opcode[1] | opcode[2]<<8)+_Y; break;
		case 7: A = (opcode[1] | opcode[2]<<8)+_X; break;
		case 8: A = opcode[1]+_Y; break;
	}

	switch (opcode[0]) {
		//Push Ops
		case 0x08: //Fall to next
		case 0x48: stackopstartaddr=stackopendaddr=X.S-1; stackop=WP_W; StackAddrBackup = X.S; StackNextIgnorePC=_PC+1; break;
		//Pull Ops
		case 0x28: //Fall to next
		case 0x68: stackopstartaddr=stackopendaddr=X.S+1; stackop=WP_R; StackAddrBackup = X.S; StackNextIgnorePC=_PC+1; break;
		//JSR (Includes return address - 1)
		case 0x20: stackopstartaddr=stackopendaddr=X.S-1; stackop=WP_W; StackAddrBackup = X.S; StackNextIgnorePC=(opcode[1]|opcode[2]<<8); break;
		//RTI (Includes processor status, and exact return address)
		case 0x40: stackopstartaddr=X.S+1; stackopendaddr=X.S+3; stackop=WP_R; StackAddrBackup = X.S; StackNextIgnorePC=(GetMem(X.S+2|0x0100)|GetMem(X.S+3|0x0100)<<8); break;
		//RTS (Includes return address - 1)
		case 0x60: stackopstartaddr=X.S+1; stackopendaddr=X.S+2; stackop=WP_R; StackAddrBackup = X.S; StackNextIgnorePC=(GetMem(stackopstartaddr|0x0100)|GetMem(stackopendaddr|0x0100)<<8)+1; break;
	}

	for (i = 0; i < numWPs; i++) {
// ################################## Start of SP CODE ###########################
		if (condition(&watchpoint[i]))
		{
// ################################## End of SP CODE ###########################
			if (watchpoint[i].flags & BT_P) { //PPU Mem breaks
				if ((watchpoint[i].flags & WP_E) && (watchpoint[i].flags & brk_type) && ((A >= 0x2000) && (A < 0x4000)) && ((A&7) == 7)) {
					if (watchpoint[i].endaddress) {
						if ((watchpoint[i].address <= RefreshAddr) && (watchpoint[i].endaddress >= RefreshAddr)) BreakHit();
					}
					else if (watchpoint[i].address == RefreshAddr) BreakHit();
				}
			}
			else if (watchpoint[i].flags & BT_S) { //Sprite Mem breaks
				if ((watchpoint[i].flags & WP_E) && (watchpoint[i].flags & brk_type) && ((A >= 0x2000) && (A < 0x4000)) && ((A&7) == 4)) {
					if (watchpoint[i].endaddress) {
						if ((watchpoint[i].address <= PPU[3]) && (watchpoint[i].endaddress >= PPU[3])) BreakHit();
					}
					else if (watchpoint[i].address == PPU[3]) BreakHit();
				}
				else if ((watchpoint[i].flags & WP_E) && (watchpoint[i].flags & WP_W) && (A == 0x4014)) BreakHit(); //Sprite DMA! :P
			}
			else { //CPU mem breaks
				if ((watchpoint[i].flags & WP_E) && (watchpoint[i].flags & brk_type)) {
					if (watchpoint[i].endaddress) {
						if (((watchpoint[i].flags & (WP_R | WP_W)) && (watchpoint[i].address <= A) && (watchpoint[i].endaddress >= A)) ||
							((watchpoint[i].flags & WP_X) && (watchpoint[i].address <= _PC) && (watchpoint[i].endaddress >= _PC))) BreakHit();
					}
					else if (((watchpoint[i].flags & (WP_R | WP_W)) && (watchpoint[i].address == A)) ||
							((watchpoint[i].flags & WP_X) && (watchpoint[i].address == _PC))) BreakHit();
				}
				else if (watchpoint[i].flags & WP_E) {
					//brk_type independant coding

					if (stackop>0) {
						//Announced stack mem breaks
						//PHA, PLA, PHP, and PLP affect the stack data.
						//TXS and TSX only deal with the pointer.
						if (watchpoint[i].flags & stackop) {
							for (j = (stackopstartaddr|0x0100); j <= (stackopendaddr|0x0100); j++) {
								if (watchpoint[i].endaddress) {
									if ((watchpoint[i].address <= j) && (watchpoint[i].endaddress >= j)) BreakHit();
								}
								else if (watchpoint[i].address == j) BreakHit();
							}
						}
					}
					if (StackNextIgnorePC==_PC) {
						//Used to make it ignore the unannounced stack code one time
						StackNextIgnorePC = 0xFFFF;
					} else 
					{
						if ((X.S < StackAddrBackup) && (stackop==0)) {
							//Unannounced stack mem breaks
							//Pushes to stack
							if (watchpoint[i].flags & WP_W) {
								for (j = (X.S|0x0100); j < (StackAddrBackup|0x0100); j++) {
									if (watchpoint[i].endaddress) {
										if ((watchpoint[i].address <= j) && (watchpoint[i].endaddress >= j)) BreakHit();
									}
									else if (watchpoint[i].address == j) BreakHit();
								}
							}
						}
						else if ((StackAddrBackup < X.S) && (stackop==0)) {
							//Pulls from stack
							if (watchpoint[i].flags & WP_R) {
								for (j = (StackAddrBackup|0x0100); j < (X.S|0x0100); j++) {
									if (watchpoint[i].endaddress) {
										if ((watchpoint[i].address <= j) && (watchpoint[i].endaddress >= j)) BreakHit();
									}
									else if (watchpoint[i].address == j) BreakHit();
								}
							}
						}
					}

				}
			}
// ################################## Start of SP CODE ###########################
		}
// ################################## End of SP CODE ###########################
	}

	//Update the stack address with the current one, now that changes have registered.
	StackAddrBackup = X.S;
}
//bbit edited: this is the end of the inserted code

int debug_tracing;

void DebugCycle() {
	
	if (scanline == 240)
	{
		vblankScanLines = (PAL?int((double)timestamp / ((double)341 / (double)3.2)):timestamp / 114);	//114 approximates the number of timestamps per scanline during vblank.  Approx 2508. NTSC: (341 / 3.0) PAL: (341 / 3.2). Uses (3.? * cpu_cycles) / 341.0, and assumes 1 cpu cycle.
		if (vblankScanLines) vblankPixel = 341 / vblankScanLines;	//341 pixels per scanline
		//FCEUI_printf("vbPixel = %d",vblankPixel);					     //Debug
		//FCEUI_printf("ts: %d line: %d\n", timestamp, vblankScanLines); //Debug
	}
	else
		vblankScanLines = 0;
	
	if (GameInfo->type==GIT_NSF)  
	{
		if ((_PC >= 0x3801) && (_PC <= 0x3824)) return;
	}

	if (numWPs || dbgstate.step || dbgstate.runline || dbgstate.stepout || watchpoint[64].flags || dbgstate.badopbreak) 
		breakpoint();
	if(debug_loggingCD) LogCDData();
	
	//mbg 6/30/06 - this was commented out when i got here. i dont understand it anyway
 	//if(logging || (hMemView && (EditingMode == 2))) LogInstruction();
 
//This needs to be windows only or else the linux build system will fail since logging is declared in a 
//windows source file
#ifdef WIN32
	extern volatile int logging; //UGETAB: This is required to be an extern, because the info isn't set here
	if(logging) FCEUD_TraceInstruction();
#endif
}