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

    debugcpu.c

    Debugger CPU/memory interface engine.

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

    Copyright Aaron Giles
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above copyright
          notice, this list of conditions and the following disclaimer in
          the documentation and/or other materials provided with the
          distribution.
        * Neither the name 'MAME' nor the names of its contributors may be
          used to endorse or promote products derived from this software
          without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

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

#include "emu.h"
#include "emuopts.h"
#include "osdepend.h"
#include "debugcpu.h"
#include "debugcmd.h"
#include "debugcon.h"
#include "express.h"
#include "debugvw.h"
#include "debugger.h"
#include "debugint/debugint.h"
#include "uiinput.h"
#include "xmlfile.h"
#include <ctype.h>
#include <zlib.h>


/***************************************************************************
    CONSTANTS
***************************************************************************/

#define NUM_TEMP_VARIABLES	10

enum
{
	EXECUTION_STATE_STOPPED,
	EXECUTION_STATE_RUNNING
};



/***************************************************************************
    TYPE DEFINITIONS
***************************************************************************/

/* in mame.h: typedef struct _debugcpu_private debugcpu_private; */
struct _debugcpu_private
{
	device_t *livecpu;
	device_t *visiblecpu;
	device_t *breakcpu;

	FILE *			source_file;				/* script source file */

	symbol_table *	symtable;					/* global symbol table */

	bool			within_instruction_hook;
	bool			vblank_occurred;
	bool			memory_modified;
	bool			debugger_access;

	int				execution_state;
	device_t *		m_stop_when_not_device;		// stop execution when the device ceases to be this

	UINT32			bpindex;
	UINT32			wpindex;

	UINT64			wpdata;
	UINT64			wpaddr;
	UINT64			tempvar[NUM_TEMP_VARIABLES];

	osd_ticks_t 	last_periodic_update_time;

	bool			comments_loaded;
};



/***************************************************************************
    FUNCTION PROTOTYPES
***************************************************************************/

/* internal helpers */
static void debug_cpu_exit(running_machine &machine);
static void on_vblank(running_machine &machine, screen_device &device, bool vblank_state);
static void reset_transient_flags(running_machine &machine);
static void process_source_file(running_machine &machine);

/* expression handlers */
static UINT64 expression_read_memory(void *param, const char *name, expression_space space, UINT32 address, int size);
static UINT64 expression_read_program_direct(address_space *space, int opcode, offs_t address, int size);
static UINT64 expression_read_memory_region(running_machine &machine, const char *rgntag, offs_t address, int size);
static void expression_write_memory(void *param, const char *name, expression_space space, UINT32 address, int size, UINT64 data);
static void expression_write_program_direct(address_space *space, int opcode, offs_t address, int size, UINT64 data);
static void expression_write_memory_region(running_machine &machine, const char *rgntag, offs_t address, int size, UINT64 data);
static expression_error::error_code expression_validate(void *param, const char *name, expression_space space);

/* variable getters/setters */
static UINT64 get_cpunum(symbol_table &table, void *ref);
static UINT64 get_beamx(symbol_table &table, void *ref);
static UINT64 get_beamy(symbol_table &table, void *ref);
static UINT64 get_frame(symbol_table &table, void *ref);



/***************************************************************************
    INITIALIZATION AND CLEANUP
***************************************************************************/

/*-------------------------------------------------
    debug_cpu_init - initialize the CPU
    information for debugging
-------------------------------------------------*/

void debug_cpu_init(running_machine &machine)
{
	screen_device *first_screen = machine.first_screen();
	debugcpu_private *global;
	int regnum;

	/* allocate and reset globals */
	machine.debugcpu_data = global = auto_alloc_clear(machine, debugcpu_private);
	global->execution_state = EXECUTION_STATE_STOPPED;
	global->bpindex = 1;
	global->wpindex = 1;

	/* create a global symbol table */
	global->symtable = global_alloc(symbol_table(&machine));

	// configure our base memory accessors
	debug_cpu_configure_memory(machine, *global->symtable);

	/* add "wpaddr", "wpdata", "cycles", "cpunum", "logunmap" to the global symbol table */
	global->symtable->add("wpaddr", symbol_table::READ_ONLY, &global->wpaddr);
	global->symtable->add("wpdata", symbol_table::READ_ONLY, &global->wpdata);
	global->symtable->add("cpunum", NULL, get_cpunum);
	global->symtable->add("beamx", (void *)first_screen, get_beamx);
	global->symtable->add("beamy", (void *)first_screen, get_beamy);
	global->symtable->add("frame", (void *)first_screen, get_frame);

	/* add the temporary variables to the global symbol table */
	for (regnum = 0; regnum < NUM_TEMP_VARIABLES; regnum++)
	{
		char symname[10];
		sprintf(symname, "temp%d", regnum);
		global->symtable->add(symname, symbol_table::READ_WRITE, &global->tempvar[regnum]);
	}

	/* first CPU is visible by default */
	global->visiblecpu = machine.firstcpu;

	/* add callback for breaking on VBLANK */
	if (machine.primary_screen != NULL)
		machine.primary_screen->register_vblank_callback(vblank_state_delegate(FUNC(on_vblank), &machine));

	machine.add_notifier(MACHINE_NOTIFY_EXIT, machine_notify_delegate(FUNC(debug_cpu_exit), &machine));
}


void debug_cpu_configure_memory(running_machine &machine, symbol_table &table)
{
	table.configure_memory(&machine, expression_validate, expression_read_memory, expression_write_memory);
}


/*-------------------------------------------------
    debug_cpu_flush_traces - flushes all traces;
    this is useful if a trace is going on when we
    fatalerror
-------------------------------------------------*/

void debug_cpu_flush_traces(running_machine &machine)
{
	/* this can be called on exit even when no debugging is enabled, so
     make sure the devdebug is valid before proceeding */
    device_iterator iter(machine.root_device());
	for (device_t *device = iter.first(); device != NULL; device = iter.next())
		if (device->debug() != NULL)
			device->debug()->trace_flush();
}



/***************************************************************************
    DEBUGGING STATUS AND INFORMATION
***************************************************************************/

/*-------------------------------------------------
    cpu_get_visible_cpu - return the visible CPU
    device (the one that commands should apply to)
-------------------------------------------------*/

device_t *debug_cpu_get_visible_cpu(running_machine &machine)
{
	return machine.debugcpu_data->visiblecpu;
}


/*-------------------------------------------------
    debug_cpu_within_instruction_hook - true if
    the debugger is currently live
-------------------------------------------------*/

int debug_cpu_within_instruction_hook(running_machine &machine)
{
	return machine.debugcpu_data->within_instruction_hook;
}


/*-------------------------------------------------
    debug_cpu_is_stopped - return true if the
    current execution state is stopped
-------------------------------------------------*/

int debug_cpu_is_stopped(running_machine &machine)
{
	debugcpu_private *global = machine.debugcpu_data;
	return (global != NULL) ? (global->execution_state == EXECUTION_STATE_STOPPED) : false;
}



/***************************************************************************
    SYMBOL TABLE INTERFACES
***************************************************************************/

/*-------------------------------------------------
    debug_cpu_get_global_symtable - return the
    global symbol table
-------------------------------------------------*/

symbol_table *debug_cpu_get_global_symtable(running_machine &machine)
{
	return machine.debugcpu_data->symtable;
}


/*-------------------------------------------------
    debug_cpu_get_visible_symtable - return the
    locally-visible symbol table
-------------------------------------------------*/

symbol_table *debug_cpu_get_visible_symtable(running_machine &machine)
{
	return &machine.debugcpu_data->visiblecpu->debug()->symtable();
}


/*-------------------------------------------------
    debug_cpu_source_script - specifies a debug
    command script to execute
-------------------------------------------------*/

void debug_cpu_source_script(running_machine &machine, const char *file)
{
	debugcpu_private *global = machine.debugcpu_data;

	/* close any existing source file */
	if (global->source_file != NULL)
	{
		fclose(global->source_file);
		global->source_file = NULL;
	}

	/* open a new one if requested */
	if (file != NULL)
	{
		global->source_file = fopen(file, "r");
		if (!global->source_file)
		{
			if (machine.phase() == MACHINE_PHASE_RUNNING)
				debug_console_printf(machine, "Cannot open command file '%s'\n", file);
			else
				fatalerror("Cannot open command file '%s'", file);
		}
	}
}



//**************************************************************************
//  MEMORY AND DISASSEMBLY HELPERS
//**************************************************************************

//-------------------------------------------------
//  debug_comment_save - save all comments for
//  the given machine
//-------------------------------------------------

bool debug_comment_save(running_machine &machine)
{
	// if we don't have a root, bail
	xml_data_node *root = xml_file_create();
	if (root == NULL)
		return false;

	// wrap in a try/catch to handle errors
	try
	{
		// create a comment node
		xml_data_node *commentnode = xml_add_child(root, "mamecommentfile", NULL);
		if (commentnode == NULL)
			throw emu_exception();
		xml_set_attribute_int(commentnode, "version", COMMENT_VERSION);

		// create a system node
		xml_data_node *systemnode = xml_add_child(commentnode, "system", NULL);
		if (systemnode == NULL)
			throw emu_exception();
		xml_set_attribute(systemnode, "name", machine.system().name);

		// for each device
		device_iterator iter(machine.root_device());
		bool found_comments = false;
		for (device_t *device = iter.first(); device != NULL; device = iter.next())
			if (device->debug()->comment_count() > 0)
			{
				// create a node for this device
				xml_data_node *curnode = xml_add_child(systemnode, "cpu", NULL);
				if (curnode == NULL)
					throw emu_exception();
				xml_set_attribute(curnode, "tag", device->tag());

				// export the comments
				if (!device->debug()->comment_export(*curnode))
					throw emu_exception();
				found_comments = true;
			}

		// flush the file
		if (found_comments)
		{
			emu_file file(machine.options().comment_directory(), OPEN_FLAG_WRITE | OPEN_FLAG_CREATE | OPEN_FLAG_CREATE_PATHS);
			file_error filerr = file.open(machine.basename(), ".cmt");
			if (filerr == FILERR_NONE)
				xml_file_write(root, file);
		}
	}
	catch (emu_exception &)
	{
		xml_file_free(root);
		return false;
	}

	// free and get out of here
	xml_file_free(root);
	return true;
}


//-------------------------------------------------
//  debug_comment_load - load all comments for
//  the given machine
//-------------------------------------------------

bool debug_comment_load(running_machine &machine)
{
	// open the file
	emu_file file(machine.options().comment_directory(), OPEN_FLAG_READ);
	file_error filerr = file.open(machine.basename(), ".cmt");

	// if an error, just return false
	if (filerr != FILERR_NONE)
		return false;

	// wrap in a try/catch to handle errors
	xml_data_node *root = xml_file_read(file, NULL);
	try
	{
		// read the file
		if (root == NULL)
			throw emu_exception();

		// find the config node
		xml_data_node *commentnode = xml_get_sibling(root->child, "mamecommentfile");
		if (commentnode == NULL)
			throw emu_exception();

		// validate the config data version
		int version = xml_get_attribute_int(commentnode, "version", 0);
		if (version != COMMENT_VERSION)
			throw emu_exception();

		// check to make sure the file is applicable
		xml_data_node *systemnode = xml_get_sibling(commentnode->child, "system");
		const char *name = xml_get_attribute_string(systemnode, "name", "");
		if (strcmp(name, machine.system().name) != 0)
			throw emu_exception();

		// iterate over devices
		for (xml_data_node *cpunode = xml_get_sibling(systemnode->child, "cpu"); cpunode; cpunode = xml_get_sibling(cpunode->next, "cpu"))
		{
			device_t *device = machine.device(xml_get_attribute_string(cpunode, "tag", ""));
			if (device != NULL)
				if (!device->debug()->comment_import(*cpunode))
					throw emu_exception();
		}
	}
	catch (emu_exception &)
	{
		// clean up in case of error
		if (root != NULL)
			xml_file_free(root);
		return false;
	}

	// free the parser
	xml_file_free(root);
	return true;
}



/***************************************************************************
    MEMORY AND DISASSEMBLY HELPERS
***************************************************************************/

/*-------------------------------------------------
    debug_cpu_translate - return the physical
    address corresponding to the given logical
    address
-------------------------------------------------*/

int debug_cpu_translate(address_space *space, int intention, offs_t *address)
{
	device_memory_interface *memory;
	if (space->device().interface(memory))
		return memory->translate(space->spacenum(), intention, *address);
	return true;
}


/***************************************************************************
    DEBUGGER MEMORY ACCESSORS
***************************************************************************/

/*-------------------------------------------------
    debug_read_byte - return a byte from the
    the specified memory space
-------------------------------------------------*/

UINT8 debug_read_byte(address_space *_space, offs_t address, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;
	UINT64 custom;
	UINT8 result;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* all accesses from this point on are for the debugger */
	space->set_debugger_access(global->debugger_access = true);

	/* translate if necessary; if not mapped, return 0xff */
	if (apply_translation && !debug_cpu_translate(space, TRANSLATE_READ_DEBUG, &address))
		result = 0xff;

	/* if there is a custom read handler, and it returns true, use that value */
	else if (space->device().memory().read(space->spacenum(), address, 1, custom))
		result = custom;

	/* otherwise, call the byte reading function for the translated address */
	else
		result = space->read_byte(address);

	/* no longer accessing via the debugger */
	space->set_debugger_access(global->debugger_access = false);
	return result;
}


/*-------------------------------------------------
    debug_read_word - return a word from the
    specified memory space
-------------------------------------------------*/

UINT16 debug_read_word(address_space *_space, offs_t address, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;
	UINT16 result;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* if this is misaligned read, or if there are no word readers, just read two bytes */
	if ((address & 1) != 0)
	{
		UINT8 byte0 = debug_read_byte(space, address + 0, apply_translation);
		UINT8 byte1 = debug_read_byte(space, address + 1, apply_translation);

		/* based on the endianness, the result is assembled differently */
		if (space->endianness() == ENDIANNESS_LITTLE)
			result = byte0 | (byte1 << 8);
		else
			result = byte1 | (byte0 << 8);
	}

	/* otherwise, this proceeds like the byte case */
	else
	{
		UINT64 custom;

		/* all accesses from this point on are for the debugger */
		space->set_debugger_access(global->debugger_access = true);

		/* translate if necessary; if not mapped, return 0xffff */
		if (apply_translation && !debug_cpu_translate(space, TRANSLATE_READ_DEBUG, &address))
			result = 0xffff;

		/* if there is a custom read handler, and it returns true, use that value */
		else if (space->device().memory().read(space->spacenum(), address, 2, custom))
			result = custom;

		/* otherwise, call the byte reading function for the translated address */
		else
			result = space->read_word(address);

		/* no longer accessing via the debugger */
		space->set_debugger_access(global->debugger_access = false);
	}

	return result;
}


/*-------------------------------------------------
    debug_read_dword - return a dword from the
    specified memory space
-------------------------------------------------*/

UINT32 debug_read_dword(address_space *_space, offs_t address, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;
	UINT32 result;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* if this is misaligned read, or if there are no dword readers, just read two words */
	if ((address & 3) != 0)
	{
		UINT16 word0 = debug_read_word(space, address + 0, apply_translation);
		UINT16 word1 = debug_read_word(space, address + 2, apply_translation);

		/* based on the endianness, the result is assembled differently */
		if (space->endianness() == ENDIANNESS_LITTLE)
			result = word0 | (word1 << 16);
		else
			result = word1 | (word0 << 16);
	}

	/* otherwise, this proceeds like the byte case */
	else
	{
		UINT64 custom;

		/* all accesses from this point on are for the debugger */
		space->set_debugger_access(global->debugger_access = true);

		/* translate if necessary; if not mapped, return 0xffffffff */
		if (apply_translation && !debug_cpu_translate(space, TRANSLATE_READ_DEBUG, &address))
			result = 0xffffffff;

		/* if there is a custom read handler, and it returns true, use that value */
		else if (space->device().memory().read(space->spacenum(), address, 4, custom))
			result = custom;

		/* otherwise, call the byte reading function for the translated address */
		else
			result = space->read_dword(address);

		/* no longer accessing via the debugger */
		space->set_debugger_access(global->debugger_access = false);
	}

	return result;
}


/*-------------------------------------------------
    debug_read_qword - return a qword from the
    specified memory space
-------------------------------------------------*/

UINT64 debug_read_qword(address_space *_space, offs_t address, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;
	UINT64 result;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* if this is misaligned read, or if there are no qword readers, just read two dwords */
	if ((address & 7) != 0)
	{
		UINT32 dword0 = debug_read_dword(space, address + 0, apply_translation);
		UINT32 dword1 = debug_read_dword(space, address + 4, apply_translation);

		/* based on the endianness, the result is assembled differently */
		if (space->endianness() == ENDIANNESS_LITTLE)
			result = dword0 | ((UINT64)dword1 << 32);
		else
			result = dword1 | ((UINT64)dword0 << 32);
	}

	/* otherwise, this proceeds like the byte case */
	else
	{
		UINT64 custom;

		/* all accesses from this point on are for the debugger */
		space->set_debugger_access(global->debugger_access = true);

		/* translate if necessary; if not mapped, return 0xffffffffffffffff */
		if (apply_translation && !debug_cpu_translate(space, TRANSLATE_READ_DEBUG, &address))
			result = ~(UINT64)0;

		/* if there is a custom read handler, and it returns true, use that value */
		else if (space->device().memory().read(space->spacenum(), address, 8, custom))
			result = custom;

		/* otherwise, call the byte reading function for the translated address */
		else
			result = space->read_qword(address);

		/* no longer accessing via the debugger */
		space->set_debugger_access(global->debugger_access = false);
	}

	return result;
}


/*-------------------------------------------------
    debug_read_memory - return 1,2,4 or 8 bytes
    from the specified memory space
-------------------------------------------------*/

UINT64 debug_read_memory(address_space *space, offs_t address, int size, int apply_translation)
{
	UINT64 result = ~(UINT64)0 >> (64 - 8*size);
	switch (size)
	{
		case 1:		result = debug_read_byte(space, address, apply_translation);	break;
		case 2:		result = debug_read_word(space, address, apply_translation);	break;
		case 4:		result = debug_read_dword(space, address, apply_translation);	break;
		case 8:		result = debug_read_qword(space, address, apply_translation);	break;
	}
	return result;
}


/*-------------------------------------------------
    debug_write_byte - write a byte to the
    specified memory space
-------------------------------------------------*/

void debug_write_byte(address_space *_space, offs_t address, UINT8 data, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* all accesses from this point on are for the debugger */
	space->set_debugger_access(global->debugger_access = true);

	/* translate if necessary; if not mapped, we're done */
	if (apply_translation && !debug_cpu_translate(space, TRANSLATE_WRITE_DEBUG, &address))
		;

	/* if there is a custom write handler, and it returns true, use that */
	else if (space->device().memory().write(space->spacenum(), address, 1, data))
		;

	/* otherwise, call the byte reading function for the translated address */
	else
		space->write_byte(address, data);

	/* no longer accessing via the debugger */
	space->set_debugger_access(global->debugger_access = false);
	global->memory_modified = true;
}


/*-------------------------------------------------
    debug_write_word - write a word to the
    specified memory space
-------------------------------------------------*/

void debug_write_word(address_space *_space, offs_t address, UINT16 data, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* if this is a misaligned write, or if there are no word writers, just read two bytes */
	if ((address & 1) != 0)
	{
		if (space->endianness() == ENDIANNESS_LITTLE)
		{
			debug_write_byte(space, address + 0, data >> 0, apply_translation);
			debug_write_byte(space, address + 1, data >> 8, apply_translation);
		}
		else
		{
			debug_write_byte(space, address + 0, data >> 8, apply_translation);
			debug_write_byte(space, address + 1, data >> 0, apply_translation);
		}
	}

	/* otherwise, this proceeds like the byte case */
	else
	{
		/* all accesses from this point on are for the debugger */
		space->set_debugger_access(global->debugger_access = true);

		/* translate if necessary; if not mapped, we're done */
		if (apply_translation && !debug_cpu_translate(space, TRANSLATE_WRITE_DEBUG, &address))
			;

		/* if there is a custom write handler, and it returns true, use that */
		else if (space->device().memory().write(space->spacenum(), address, 2, data))
			;

		/* otherwise, call the byte reading function for the translated address */
		else
			space->write_word(address, data);

		/* no longer accessing via the debugger */
		space->set_debugger_access(global->debugger_access = false);
		global->memory_modified = true;
	}
}


/*-------------------------------------------------
    debug_write_dword - write a dword to the
    specified memory space
-------------------------------------------------*/

void debug_write_dword(address_space *_space, offs_t address, UINT32 data, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* if this is a misaligned write, or if there are no dword writers, just read two words */
	if ((address & 3) != 0)
	{
		if (space->endianness() == ENDIANNESS_LITTLE)
		{
			debug_write_word(space, address + 0, data >> 0, apply_translation);
			debug_write_word(space, address + 2, data >> 16, apply_translation);
		}
		else
		{
			debug_write_word(space, address + 0, data >> 16, apply_translation);
			debug_write_word(space, address + 2, data >> 0, apply_translation);
		}
	}

	/* otherwise, this proceeds like the byte case */
	else
	{
		/* all accesses from this point on are for the debugger */
		space->set_debugger_access(global->debugger_access = true);

		/* translate if necessary; if not mapped, we're done */
		if (apply_translation && !debug_cpu_translate(space, TRANSLATE_WRITE_DEBUG, &address))
			;

		/* if there is a custom write handler, and it returns true, use that */
		else if (space->device().memory().write(space->spacenum(), address, 4, data))
			;

		/* otherwise, call the byte reading function for the translated address */
		else
			space->write_dword(address, data);

		/* no longer accessing via the debugger */
		space->set_debugger_access(global->debugger_access = false);
		global->memory_modified = true;
	}
}


/*-------------------------------------------------
    debug_write_qword - write a qword to the
    specified memory space
-------------------------------------------------*/

void debug_write_qword(address_space *_space, offs_t address, UINT64 data, int apply_translation)
{
	address_space *space = const_cast<address_space *>(_space);
	debugcpu_private *global = space->machine().debugcpu_data;

	/* mask against the logical byte mask */
	address &= space->logbytemask();

	/* if this is a misaligned write, or if there are no qword writers, just read two dwords */
	if ((address & 7) != 0)
	{
		if (space->endianness() == ENDIANNESS_LITTLE)
		{
			debug_write_dword(space, address + 0, data >> 0, apply_translation);
			debug_write_dword(space, address + 4, data >> 32, apply_translation);
		}
		else
		{
			debug_write_dword(space, address + 0, data >> 32, apply_translation);
			debug_write_dword(space, address + 4, data >> 0, apply_translation);
		}
	}

	/* otherwise, this proceeds like the byte case */
	else
	{
		/* all accesses from this point on are for the debugger */
		space->set_debugger_access(global->debugger_access = true);

		/* translate if necessary; if not mapped, we're done */
		if (apply_translation && !debug_cpu_translate(space, TRANSLATE_WRITE_DEBUG, &address))
			;

		/* if there is a custom write handler, and it returns true, use that */
		else if (space->device().memory().write(space->spacenum(), address, 8, data))
			;

		/* otherwise, call the byte reading function for the translated address */
		else
			space->write_qword(address, data);

		/* no longer accessing via the debugger */
		space->set_debugger_access(global->debugger_access = false);
		global->memory_modified = true;
	}
}


/*-------------------------------------------------
    debug_write_memory - write 1,2,4 or 8 bytes
    to the specified memory space
-------------------------------------------------*/

void debug_write_memory(address_space *space, offs_t address, UINT64 data, int size, int apply_translation)
{
	switch (size)
	{
		case 1:		debug_write_byte(space, address, data, apply_translation);	break;
		case 2:		debug_write_word(space, address, data, apply_translation);	break;
		case 4:		debug_write_dword(space, address, data, apply_translation);	break;
		case 8:		debug_write_qword(space, address, data, apply_translation);	break;
	}
}


/*-------------------------------------------------
    debug_read_opcode - read 1,2,4 or 8 bytes at
    the given offset from opcode space
-------------------------------------------------*/

UINT64 debug_read_opcode(address_space *_space, offs_t address, int size, int arg)
{
	address_space *space = const_cast<address_space *>(_space);
	UINT64 result = ~(UINT64)0 & (~(UINT64)0 >> (64 - 8*size)), result2;
	debugcpu_private *global = space->machine().debugcpu_data;

	/* keep in logical range */
	address &= space->logbytemask();

	/* return early if we got the result directly */
	space->set_debugger_access(global->debugger_access = true);
	device_memory_interface *memory;
	if (space->device().interface(memory) && memory->readop(address, size, result2))
	{
		space->set_debugger_access(global->debugger_access = false);
		return result2;
	}

	/* if we're bigger than the address bus, break into smaller pieces */
	if (size > space->data_width() / 8)
	{
		int halfsize = size / 2;
		UINT64 r0 = debug_read_opcode(space, address + 0, halfsize, arg);
		UINT64 r1 = debug_read_opcode(space, address + halfsize, halfsize, arg);

		if (space->endianness() == ENDIANNESS_LITTLE)
			return r0 | (r1 << (8 * halfsize));
		else
			return r1 | (r0 << (8 * halfsize));
	}

	/* translate to physical first */
	if (!debug_cpu_translate(space, TRANSLATE_FETCH_DEBUG, &address))
		return result;

	/* keep in physical range */
	address &= space->bytemask();
	offs_t addrxor = 0;
	switch (space->data_width() / 8 * 10 + size)
	{
		/* dump opcodes in bytes from a byte-sized bus */
		case 11:
			break;

		/* dump opcodes in bytes from a word-sized bus */
		case 21:
			addrxor = (space->endianness() == ENDIANNESS_LITTLE) ? BYTE_XOR_LE(0) : BYTE_XOR_BE(0);
			break;

		/* dump opcodes in words from a word-sized bus */
		case 22:
			break;

		/* dump opcodes in bytes from a dword-sized bus */
		case 41:
			addrxor = (space->endianness() == ENDIANNESS_LITTLE) ? BYTE4_XOR_LE(0) : BYTE4_XOR_BE(0);
			break;

		/* dump opcodes in words from a dword-sized bus */
		case 42:
			addrxor = (space->endianness() == ENDIANNESS_LITTLE) ? WORD_XOR_LE(0) : WORD_XOR_BE(0);
			break;

		/* dump opcodes in dwords from a dword-sized bus */
		case 44:
			break;

		/* dump opcodes in bytes from a qword-sized bus */
		case 81:
			addrxor = (space->endianness() == ENDIANNESS_LITTLE) ? BYTE8_XOR_LE(0) : BYTE8_XOR_BE(0);
			break;

		/* dump opcodes in words from a qword-sized bus */
		case 82:
			addrxor = (space->endianness() == ENDIANNESS_LITTLE) ? WORD2_XOR_LE(0) : WORD2_XOR_BE(0);
			break;

		/* dump opcodes in dwords from a qword-sized bus */
		case 84:
			addrxor = (space->endianness() == ENDIANNESS_LITTLE) ? DWORD_XOR_LE(0) : DWORD_XOR_BE(0);
			break;

		/* dump opcodes in qwords from a qword-sized bus */
		case 88:
			break;

		default:
			fatalerror("debug_read_opcode: unknown type = %d", space->data_width() / 8 * 10 + size);
			break;
	}

	/* turn on debugger access */
	if (!global->debugger_access)
		space->set_debugger_access(global->debugger_access = true);

	/* switch off the size and handle unaligned accesses */
	switch (size)
	{
		case 1:
			result = (arg) ? space->direct().read_raw_byte(address, addrxor) : space->direct().read_decrypted_byte(address, addrxor);
			break;

		case 2:
			result = (arg) ? space->direct().read_raw_word(address & ~1, addrxor) : space->direct().read_decrypted_word(address & ~1, addrxor);
			if ((address & 1) != 0)
			{
				result2 = (arg) ? space->direct().read_raw_word((address & ~1) + 2, addrxor) : space->direct().read_decrypted_word((address & ~1) + 2, addrxor);
				if (space->endianness() == ENDIANNESS_LITTLE)
					result = (result >> (8 * (address & 1))) | (result2 << (16 - 8 * (address & 1)));
				else
					result = (result << (8 * (address & 1))) | (result2 >> (16 - 8 * (address & 1)));
				result &= 0xffff;
			}
			break;

		case 4:
			result = (arg) ? space->direct().read_raw_dword(address & ~3, addrxor) : space->direct().read_decrypted_dword(address & ~3, addrxor);
			if ((address & 3) != 0)
			{
				result2 = (arg) ? space->direct().read_raw_dword((address & ~3) + 4, addrxor) : space->direct().read_decrypted_dword((address & ~3) + 4, addrxor);
				if (space->endianness() == ENDIANNESS_LITTLE)
					result = (result >> (8 * (address & 3))) | (result2 << (32 - 8 * (address & 3)));
				else
					result = (result << (8 * (address & 3))) | (result2 >> (32 - 8 * (address & 3)));
				result &= 0xffffffff;
			}
			break;

		case 8:
			result = (arg) ? space->direct().read_raw_qword(address & ~7, addrxor) : space->direct().read_decrypted_qword(address & ~7, addrxor);
			if ((address & 7) != 0)
			{
				result2 = (arg) ? space->direct().read_raw_qword((address & ~7) + 8, addrxor) : space->direct().read_decrypted_qword((address & ~7) + 8, addrxor);
				if (space->endianness() == ENDIANNESS_LITTLE)
					result = (result >> (8 * (address & 7))) | (result2 << (64 - 8 * (address & 7)));
				else
					result = (result << (8 * (address & 7))) | (result2 >> (64 - 8 * (address & 7)));
			}
			break;
	}

	/* no longer accessing via the debugger */
	space->set_debugger_access(global->debugger_access = false);
	return result;
}



/***************************************************************************
    INTERNAL HELPERS
***************************************************************************/

/*-------------------------------------------------
    debug_cpu_exit - free all memory
-------------------------------------------------*/

static void debug_cpu_exit(running_machine &machine)
{
	debugcpu_private *global = machine.debugcpu_data;

	/* free the global symbol table */
	if (global != NULL)
		global_free(global->symtable);
}


/*-------------------------------------------------
    on_vblank - called when a VBLANK hits
-------------------------------------------------*/

static void on_vblank(running_machine &machine, screen_device &device, bool vblank_state)
{
	/* just set a global flag to be consumed later */
	if (vblank_state)
		device.machine().debugcpu_data->vblank_occurred = true;
}


/*-------------------------------------------------
    reset_transient_flags - reset the transient
    flags on all CPUs
-------------------------------------------------*/

static void reset_transient_flags(running_machine &machine)
{
	/* loop over CPUs and reset the transient flags */
	device_iterator iter(machine.root_device());
	for (device_t *device = iter.first(); device != NULL; device = iter.next())
		device->debug()->reset_transient_flag();
	machine.debugcpu_data->m_stop_when_not_device = NULL;
}


/*-------------------------------------------------
    process_source_file - executes commands from
    a source file
-------------------------------------------------*/

static void process_source_file(running_machine &machine)
{
	debugcpu_private *global = machine.debugcpu_data;

	/* loop until the file is exhausted or until we are executing again */
	while (global->source_file != NULL && global->execution_state == EXECUTION_STATE_STOPPED)
	{
		char buf[512];
		int i;
		char *s;

		/* stop at the end of file */
		if (feof(global->source_file))
		{
			fclose(global->source_file);
			global->source_file = NULL;
			return;
		}

		/* fetch the next line */
		memset(buf, 0, sizeof(buf));
		fgets(buf, sizeof(buf), global->source_file);

		/* strip out comments (text after '//') */
		s = strstr(buf, "//");
		if (s)
			*s = '\0';

		/* strip whitespace */
		i = (int)strlen(buf);
		while((i > 0) && (isspace((UINT8)buf[i-1])))
			buf[--i] = '\0';

		/* execute the command */
		if (buf[0])
			debug_console_execute_command(machine, buf, 1);
	}
}



/***************************************************************************
    EXPRESSION HANDLERS
***************************************************************************/

/*-------------------------------------------------
    expression_get_device - return a device
    based on a case insensitive tag search
-------------------------------------------------*/

static device_t *expression_get_device(running_machine &machine, const char *tag)
{
	// convert to lowercase then lookup the name (tags are enforced to be all lower case)
	astring fullname(tag);
	fullname.makelower();
	return machine.device(fullname);
}


/*-------------------------------------------------
    expression_read_memory - read 1,2,4 or 8 bytes
    at the given offset in the given address
    space
-------------------------------------------------*/

static UINT64 expression_read_memory(void *param, const char *name, expression_space spacenum, UINT32 address, int size)
{
	running_machine &machine = *(running_machine *)param;
	UINT64 result = ~(UINT64)0 >> (64 - 8*size);
	device_t *device = NULL;
	address_space *space;

	switch (spacenum)
	{
		case EXPSPACE_PROGRAM_LOGICAL:
		case EXPSPACE_DATA_LOGICAL:
		case EXPSPACE_IO_LOGICAL:
		case EXPSPACE_SPACE3_LOGICAL:
			if (name != NULL)
				device = expression_get_device(machine, name);
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			space = device->memory().space(AS_PROGRAM + (spacenum - EXPSPACE_PROGRAM_LOGICAL));
			if (space != NULL)
				result = debug_read_memory(space, space->address_to_byte(address), size, true);
			break;

		case EXPSPACE_PROGRAM_PHYSICAL:
		case EXPSPACE_DATA_PHYSICAL:
		case EXPSPACE_IO_PHYSICAL:
		case EXPSPACE_SPACE3_PHYSICAL:
			if (name != NULL)
				device = expression_get_device(machine, name);
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			space = device->memory().space(AS_PROGRAM + (spacenum - EXPSPACE_PROGRAM_PHYSICAL));
			if (space != NULL)
				result = debug_read_memory(space, space->address_to_byte(address), size, false);
			break;

		case EXPSPACE_OPCODE:
		case EXPSPACE_RAMWRITE:
			if (name != NULL)
				device = expression_get_device(machine, name);
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			result = expression_read_program_direct(device->memory().space(AS_PROGRAM), (spacenum == EXPSPACE_OPCODE), address, size);
			break;

		case EXPSPACE_REGION:
			if (name == NULL)
				break;
			result = expression_read_memory_region(machine, name, address, size);
			break;

		default:
			break;
	}
	return result;
}


/*-------------------------------------------------
    expression_read_program_direct - read memory
    directly from an opcode or RAM pointer
-------------------------------------------------*/

static UINT64 expression_read_program_direct(address_space *_space, int opcode, offs_t address, int size)
{
	address_space *space = const_cast<address_space *>(_space);
	UINT64 result = ~(UINT64)0 >> (64 - 8*size);

	if (space != NULL)
	{
		UINT8 *base;

		/* adjust the address into a byte address, but not if being called recursively */
		if ((opcode & 2) == 0)
			address = space->address_to_byte(address);

		/* call ourself recursively until we are byte-sized */
		if (size > 1)
		{
			int halfsize = size / 2;
			UINT64 r0, r1;

			/* read each half, from lower address to upper address */
			r0 = expression_read_program_direct(space, opcode | 2, address + 0, halfsize);
			r1 = expression_read_program_direct(space, opcode | 2, address + halfsize, halfsize);

			/* assemble based on the target endianness */
			if (space->endianness() == ENDIANNESS_LITTLE)
				result = r0 | (r1 << (8 * halfsize));
			else
				result = r1 | (r0 << (8 * halfsize));
		}

		/* handle the byte-sized final requests */
		else
		{
			/* lowmask specified which address bits are within the databus width */
			offs_t lowmask = space->data_width() / 8 - 1;

			/* get the base of memory, aligned to the address minus the lowbits */
			if (opcode & 1)
				base = (UINT8 *)space->direct().read_decrypted_ptr(address & ~lowmask);
			else
				base = (UINT8 *)space->get_read_ptr(address & ~lowmask);

			/* if we have a valid base, return the appropriate byte */
			if (base != NULL)
			{
				if (space->endianness() == ENDIANNESS_LITTLE)
					result = base[BYTE8_XOR_LE(address) & lowmask];
				else
					result = base[BYTE8_XOR_BE(address) & lowmask];
			}
		}
	}
	return result;
}


/*-------------------------------------------------
    expression_read_memory_region - read memory
    from a memory region
-------------------------------------------------*/

static UINT64 expression_read_memory_region(running_machine &machine, const char *rgntag, offs_t address, int size)
{
	const memory_region *region = machine.region(rgntag);
	UINT64 result = ~(UINT64)0 >> (64 - 8*size);

	/* make sure we get a valid base before proceeding */
	if (region != NULL)
	{
		/* call ourself recursively until we are byte-sized */
		if (size > 1)
		{
			int halfsize = size / 2;
			UINT64 r0, r1;

			/* read each half, from lower address to upper address */
			r0 = expression_read_memory_region(machine, rgntag, address + 0, halfsize);
			r1 = expression_read_memory_region(machine, rgntag, address + halfsize, halfsize);

			/* assemble based on the target endianness */
			if (region->endianness() == ENDIANNESS_LITTLE)
				result = r0 | (r1 << (8 * halfsize));
			else
				result = r1 | (r0 << (8 * halfsize));
		}

		/* only process if we're within range */
		else if (address < region->bytes())
		{
			/* lowmask specified which address bits are within the databus width */
			UINT32 lowmask = region->width() - 1;
			UINT8 *base = region->base() + (address & ~lowmask);

			/* if we have a valid base, return the appropriate byte */
			if (region->endianness() == ENDIANNESS_LITTLE)
				result = base[BYTE8_XOR_LE(address) & lowmask];
			else
				result = base[BYTE8_XOR_BE(address) & lowmask];
		}
	}
	return result;
}


/*-------------------------------------------------
    expression_write_memory - write 1,2,4 or 8
    bytes at the given offset in the given address
    space
-------------------------------------------------*/

static void expression_write_memory(void *param, const char *name, expression_space spacenum, UINT32 address, int size, UINT64 data)
{
	running_machine &machine = *(running_machine *)param;
	device_t *device = NULL;
	address_space *space;

	switch (spacenum)
	{
		case EXPSPACE_PROGRAM_LOGICAL:
		case EXPSPACE_DATA_LOGICAL:
		case EXPSPACE_IO_LOGICAL:
		case EXPSPACE_SPACE3_LOGICAL:
			if (name != NULL)
				device = expression_get_device(machine, name);
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			space = device->memory().space(AS_PROGRAM + (spacenum - EXPSPACE_PROGRAM_LOGICAL));
			if (space != NULL)
				debug_write_memory(space, space->address_to_byte(address), data, size, true);
			break;

		case EXPSPACE_PROGRAM_PHYSICAL:
		case EXPSPACE_DATA_PHYSICAL:
		case EXPSPACE_IO_PHYSICAL:
		case EXPSPACE_SPACE3_PHYSICAL:
			if (name != NULL)
				device = expression_get_device(machine, name);
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			space = device->memory().space(AS_PROGRAM + (spacenum - EXPSPACE_PROGRAM_PHYSICAL));
			if (space != NULL)
				debug_write_memory(space, space->address_to_byte(address), data, size, false);
			break;

		case EXPSPACE_OPCODE:
		case EXPSPACE_RAMWRITE:
			if (name != NULL)
				device = expression_get_device(machine, name);
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			expression_write_program_direct(device->memory().space(AS_PROGRAM), (spacenum == EXPSPACE_OPCODE), address, size, data);
			break;

		case EXPSPACE_REGION:
			if (name == NULL)
				break;
			expression_write_memory_region(machine, name, address, size, data);
			break;

		default:
			break;
	}
}


/*-------------------------------------------------
    expression_write_program_direct - write memory
    directly to an opcode or RAM pointer
-------------------------------------------------*/

static void expression_write_program_direct(address_space *_space, int opcode, offs_t address, int size, UINT64 data)
{
	address_space *space = const_cast<address_space *>(_space);
	if (space != NULL)
	{
		debugcpu_private *global = space->machine().debugcpu_data;
		UINT8 *base;

		/* adjust the address into a byte address, but not if being called recursively */
		if ((opcode & 2) == 0)
			address = space->address_to_byte(address);

		/* call ourself recursively until we are byte-sized */
		if (size > 1)
		{
			int halfsize = size / 2;
			UINT64 r0, r1, halfmask;

			/* break apart based on the target endianness */
			halfmask = ~(UINT64)0 >> (64 - 8 * halfsize);
			if (space->endianness() == ENDIANNESS_LITTLE)
			{
				r0 = data & halfmask;
				r1 = (data >> (8 * halfsize)) & halfmask;
			}
			else
			{
				r0 = (data >> (8 * halfsize)) & halfmask;
				r1 = data & halfmask;
			}

			/* write each half, from lower address to upper address */
			expression_write_program_direct(space, opcode | 2, address + 0, halfsize, r0);
			expression_write_program_direct(space, opcode | 2, address + halfsize, halfsize, r1);
		}

		/* handle the byte-sized final case */
		else
		{
			/* lowmask specified which address bits are within the databus width */
			offs_t lowmask = space->data_width() / 8 - 1;

			/* get the base of memory, aligned to the address minus the lowbits */
			if (opcode & 1)
				base = (UINT8 *)space->direct().read_decrypted_ptr(address & ~lowmask);
			else
				base = (UINT8 *)space->get_read_ptr(address & ~lowmask);

			/* if we have a valid base, write the appropriate byte */
			if (base != NULL)
			{
				if (space->endianness() == ENDIANNESS_LITTLE)
					base[BYTE8_XOR_LE(address) & lowmask] = data;
				else
					base[BYTE8_XOR_BE(address) & lowmask] = data;
				global->memory_modified = true;
			}
		}
	}
}


/*-------------------------------------------------
    expression_write_memory_region - write memory
    from a memory region
-------------------------------------------------*/

static void expression_write_memory_region(running_machine &machine, const char *rgntag, offs_t address, int size, UINT64 data)
{
	debugcpu_private *global = machine.debugcpu_data;
	const memory_region *region = machine.region(rgntag);

	/* make sure we get a valid base before proceeding */
	if (region != NULL)
	{
		/* call ourself recursively until we are byte-sized */
		if (size > 1)
		{
			int halfsize = size / 2;
			UINT64 r0, r1, halfmask;

			/* break apart based on the target endianness */
			halfmask = ~(UINT64)0 >> (64 - 8 * halfsize);
			if (region->endianness() == ENDIANNESS_LITTLE)
			{
				r0 = data & halfmask;
				r1 = (data >> (8 * halfsize)) & halfmask;
			}
			else
			{
				r0 = (data >> (8 * halfsize)) & halfmask;
				r1 = data & halfmask;
			}

			/* write each half, from lower address to upper address */
			expression_write_memory_region(machine, rgntag, address + 0, halfsize, r0);
			expression_write_memory_region(machine, rgntag, address + halfsize, halfsize, r1);
		}

		/* only process if we're within range */
		else if (address < region->bytes())
		{
			/* lowmask specified which address bits are within the databus width */
			UINT32 lowmask = region->width() - 1;
			UINT8 *base = region->base() + (address & ~lowmask);

			/* if we have a valid base, set the appropriate byte */
			if (region->endianness() == ENDIANNESS_LITTLE)
				base[BYTE8_XOR_LE(address) & lowmask] = data;
			else
				base[BYTE8_XOR_BE(address) & lowmask] = data;
			global->memory_modified = true;
		}
	}
}


/*-------------------------------------------------
    expression_validate - validate that the
    provided expression references an
    appropriate name
-------------------------------------------------*/

static expression_error::error_code expression_validate(void *param, const char *name, expression_space space)
{
	running_machine &machine = *(running_machine *)param;
	device_t *device = NULL;

	switch (space)
	{
		case EXPSPACE_PROGRAM_LOGICAL:
		case EXPSPACE_DATA_LOGICAL:
		case EXPSPACE_IO_LOGICAL:
		case EXPSPACE_SPACE3_LOGICAL:
			if (name != NULL)
			{
				device = expression_get_device(machine, name);
				if (device == NULL)
					return expression_error::INVALID_MEMORY_NAME;
			}
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			if (device->memory().space(AS_PROGRAM + (space - EXPSPACE_PROGRAM_LOGICAL)) == NULL)
				return expression_error::NO_SUCH_MEMORY_SPACE;
			break;

		case EXPSPACE_PROGRAM_PHYSICAL:
		case EXPSPACE_DATA_PHYSICAL:
		case EXPSPACE_IO_PHYSICAL:
		case EXPSPACE_SPACE3_PHYSICAL:
			if (name != NULL)
			{
				device = expression_get_device(machine, name);
				if (device == NULL)
					return expression_error::INVALID_MEMORY_NAME;
			}
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			if (device->memory().space(AS_PROGRAM + (space - EXPSPACE_PROGRAM_PHYSICAL)) == NULL)
				return expression_error::NO_SUCH_MEMORY_SPACE;
			break;

		case EXPSPACE_OPCODE:
		case EXPSPACE_RAMWRITE:
			if (name != NULL)
			{
				device = expression_get_device(machine, name);
				if (device == NULL)
					return expression_error::INVALID_MEMORY_NAME;
			}
			if (device == NULL)
				device = debug_cpu_get_visible_cpu(machine);
			if (device->memory().space(AS_PROGRAM) == NULL)
				return expression_error::NO_SUCH_MEMORY_SPACE;
			break;

		case EXPSPACE_REGION:
			if (name == NULL)
				return expression_error::MISSING_MEMORY_NAME;
			if (machine.region(name)->base() == NULL)
				return expression_error::INVALID_MEMORY_NAME;
			break;

		default:
			return expression_error::NO_SUCH_MEMORY_SPACE;
	}
	return expression_error::NONE;
}



/***************************************************************************
    VARIABLE GETTERS/SETTERS
***************************************************************************/

/*-------------------------------------------------
    get_beamx - get beam horizontal position
-------------------------------------------------*/

static UINT64 get_beamx(symbol_table &table, void *ref)
{
	screen_device *screen = reinterpret_cast<screen_device *>(ref);
	return (screen != NULL) ? screen->hpos() : 0;
}


/*-------------------------------------------------
    get_beamy - get beam vertical position
-------------------------------------------------*/

static UINT64 get_beamy(symbol_table &table, void *ref)
{
	screen_device *screen = reinterpret_cast<screen_device *>(ref);
	return (screen != NULL) ? screen->vpos() : 0;
}


/*-------------------------------------------------
    get_frame - get current frame number
-------------------------------------------------*/

static UINT64 get_frame(symbol_table &table, void *ref)
{
	screen_device *screen = reinterpret_cast<screen_device *>(ref);
	return (screen != NULL) ? screen->frame_number() : 0;
}


/*-------------------------------------------------
    get_cpunum - getter callback for the
    'cpunum' symbol
-------------------------------------------------*/

static UINT64 get_cpunum(symbol_table &table, void *ref)
{
	running_machine &machine = *reinterpret_cast<running_machine *>(table.globalref());
	device_t *target = machine.debugcpu_data->visiblecpu;

	execute_interface_iterator iter(machine.root_device());
	return iter.indexof(target->execute());
}



//**************************************************************************
//  DEVICE DEBUG
//**************************************************************************

//-------------------------------------------------
//  device_debug - constructor
//-------------------------------------------------

device_debug::device_debug(device_t &device)
	: m_device(device),
	  m_exec(NULL),
	  m_memory(NULL),
	  m_state(NULL),
	  m_disasm(NULL),
	  m_flags(0),
	  m_symtable(&device, debug_cpu_get_global_symtable(device.machine())),
	  m_instrhook(NULL),
	  m_dasm_override(NULL),
	  m_opwidth(0),
	  m_stepaddr(0),
	  m_stepsleft(0),
	  m_stopaddr(0),
	  m_stoptime(attotime::zero),
	  m_stopirq(0),
	  m_stopexception(0),
	  m_endexectime(attotime::zero),
	  m_pc_history_index(0),
	  m_bplist(NULL),
	  m_trace(NULL),
	  m_hotspots(NULL),
	  m_hotspot_count(0),
	  m_hotspot_threshhold(0)
{
	memset(m_pc_history, 0, sizeof(m_pc_history));
	memset(m_wplist, 0, sizeof(m_wplist));

	m_comment_change = 0;

	// find out which interfaces we have to work with
	device.interface(m_exec);
	device.interface(m_memory);
	device.interface(m_state);
	device.interface(m_disasm);

	// set up state-related stuff
	if (m_state != NULL)
	{
		// add global symbol for cycles and totalcycles
		if (m_exec != NULL)
		{
			m_symtable.add("cycles", NULL, get_cycles);
			m_symtable.add("totalcycles", NULL, get_totalcycles);
		}

		// add entries to enable/disable unmap reporting for each space
		if (m_memory != NULL)
		{
			if (m_memory->space(AS_PROGRAM) != NULL)
				m_symtable.add("logunmap", (void *)m_memory->space(AS_PROGRAM), get_logunmap, set_logunmap);
			if (m_memory->space(AS_DATA) != NULL)
				m_symtable.add("logunmapd", (void *)m_memory->space(AS_DATA), get_logunmap, set_logunmap);
			if (m_memory->space(AS_IO) != NULL)
				m_symtable.add("logunmapi", (void *)m_memory->space(AS_IO), get_logunmap, set_logunmap);
		}

		// add all registers into it
		astring tempstr;
		for (const device_state_entry *entry = m_state->state_first(); entry != NULL; entry = entry->next())
			m_symtable.add(tempstr.cpy(entry->symbol()).makelower(), (void *)(FPTR)entry->index(), get_state, set_state);
	}

	// set up execution-related stuff
	if (m_exec != NULL)
	{
		m_flags = DEBUG_FLAG_OBSERVING | DEBUG_FLAG_HISTORY;
		m_opwidth = min_opcode_bytes();

		// if no curpc, add one
		if (m_state != NULL && m_symtable.find("curpc") == NULL)
			m_symtable.add("curpc", NULL, get_current_pc);
	}
}


//-------------------------------------------------
//  ~device_debug - constructor
//-------------------------------------------------

device_debug::~device_debug()
{
	auto_free(m_device.machine(), m_trace);

	// free breakpoints and watchpoints
	breakpoint_clear_all();
	watchpoint_clear_all();
}


//-------------------------------------------------
//  start_hook - the scheduler calls this hook
//  before beginning execution for the given device
//-------------------------------------------------

void device_debug::start_hook(attotime endtime)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert((m_device.machine().debug_flags & DEBUG_FLAG_ENABLED) != 0);

	// stash a pointer to the current live CPU
	assert(global->livecpu == NULL);
	global->livecpu = &m_device;

	// if we're a new device, stop now
	if (global->m_stop_when_not_device != NULL && global->m_stop_when_not_device != &m_device)
	{
		global->m_stop_when_not_device = NULL;
		global->execution_state = EXECUTION_STATE_STOPPED;
		reset_transient_flags(m_device.machine());
	}

	// update the target execution end time
	m_endexectime = endtime;

	// if we're running, do some periodic updating
	if (global->execution_state != EXECUTION_STATE_STOPPED)
	{
		// check for periodic updates
		if (&m_device == global->visiblecpu && osd_ticks() > global->last_periodic_update_time + osd_ticks_per_second()/4)
		{
			m_device.machine().debug_view().update_all();
			m_device.machine().debug_view().flush_osd_updates();
			global->last_periodic_update_time = osd_ticks();
		}

		// check for pending breaks
		else if (&m_device == global->breakcpu)
		{
			global->execution_state = EXECUTION_STATE_STOPPED;
			global->breakcpu = NULL;
		}

		// if a VBLANK occurred, check on things
		if (global->vblank_occurred)
		{
			global->vblank_occurred = false;

			// if we were waiting for a VBLANK, signal it now
			if ((m_flags & DEBUG_FLAG_STOP_VBLANK) != 0)
			{
				global->execution_state = EXECUTION_STATE_STOPPED;
				debug_console_printf(m_device.machine(), "Stopped at VBLANK\n");
			}
		}
		// check for debug keypresses
		if (ui_input_pressed(m_device.machine(), IPT_UI_DEBUG_BREAK))
			global->visiblecpu->debug()->halt_on_next_instruction("User-initiated break\n");
	}

	// recompute the debugging mode
	compute_debug_flags();
}


//-------------------------------------------------
//  stop_hook - the scheduler calls this hook when
//  ending execution for the given device
//-------------------------------------------------

void device_debug::stop_hook()
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(global->livecpu == &m_device);

	// clear the live CPU
	global->livecpu = NULL;
}


//-------------------------------------------------
//  interrupt_hook - called when an interrupt is
//  acknowledged
//-------------------------------------------------

void device_debug::interrupt_hook(int irqline)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	// see if this matches a pending interrupt request
	if ((m_flags & DEBUG_FLAG_STOP_INTERRUPT) != 0 && (m_stopirq == -1 || m_stopirq == irqline))
	{
		global->execution_state = EXECUTION_STATE_STOPPED;
		debug_console_printf(m_device.machine(), "Stopped on interrupt (CPU '%s', IRQ %d)\n", m_device.tag(), irqline);
		compute_debug_flags();
	}
}


//-------------------------------------------------
//  exception_hook - called when an exception is
//  generated
//-------------------------------------------------

void device_debug::exception_hook(int exception)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	// see if this matches a pending interrupt request
	if ((m_flags & DEBUG_FLAG_STOP_EXCEPTION) != 0 && (m_stopexception == -1 || m_stopexception == exception))
	{
		global->execution_state = EXECUTION_STATE_STOPPED;
		debug_console_printf(m_device.machine(), "Stopped on exception (CPU '%s', exception %d)\n", m_device.tag(), exception);
		compute_debug_flags();
	}
}


//-------------------------------------------------
//  instruction_hook - called by the CPU cores
//  before executing each instruction
//-------------------------------------------------

void device_debug::instruction_hook(offs_t curpc)
{
	running_machine &machine = m_device.machine();
	debugcpu_private *global = machine.debugcpu_data;

	// note that we are in the debugger code
	global->within_instruction_hook = true;

	// update the history
	m_pc_history[m_pc_history_index++ % HISTORY_SIZE] = curpc;

	// are we tracing?
	if (m_trace != NULL)
		m_trace->update(curpc);

	// per-instruction hook?
	if (global->execution_state != EXECUTION_STATE_STOPPED && (m_flags & DEBUG_FLAG_HOOKED) != 0 && (*m_instrhook)(m_device, curpc))
		global->execution_state = EXECUTION_STATE_STOPPED;

	// handle single stepping
	if (global->execution_state != EXECUTION_STATE_STOPPED && (m_flags & DEBUG_FLAG_STEPPING_ANY) != 0)
	{
		// is this an actual step?
		if (m_stepaddr == ~0 || curpc == m_stepaddr)
		{
			// decrement the count and reset the breakpoint
			m_stepsleft--;
			m_stepaddr = ~0;

			// if we hit 0, stop
			if (m_stepsleft == 0)
				global->execution_state = EXECUTION_STATE_STOPPED;

			// update every 100 steps until we are within 200 of the end
			else if ((m_flags & DEBUG_FLAG_STEPPING_OUT) == 0 && (m_stepsleft < 200 || m_stepsleft % 100 == 0))
			{
				machine.debug_view().update_all();
				machine.debug_view().flush_osd_updates();
				debugger_refresh_display(machine);
			}
		}
	}

	// handle breakpoints
	if (global->execution_state != EXECUTION_STATE_STOPPED && (m_flags & (DEBUG_FLAG_STOP_TIME | DEBUG_FLAG_STOP_PC | DEBUG_FLAG_LIVE_BP)) != 0)
	{
		// see if we hit a target time
		if ((m_flags & DEBUG_FLAG_STOP_TIME) != 0 && machine.time() >= m_stoptime)
		{
			debug_console_printf(machine, "Stopped at time interval %.1g\n", machine.time().as_double());
			global->execution_state = EXECUTION_STATE_STOPPED;
		}

		// check the temp running breakpoint and break if we hit it
		else if ((m_flags & DEBUG_FLAG_STOP_PC) != 0 && m_stopaddr == curpc)
		{
			debug_console_printf(machine, "Stopped at temporary breakpoint %X on CPU '%s'\n", m_stopaddr, m_device.tag());
			global->execution_state = EXECUTION_STATE_STOPPED;
		}

		// check for execution breakpoints
		else if ((m_flags & DEBUG_FLAG_LIVE_BP) != 0)
			breakpoint_check(curpc);
	}

	// if we are supposed to halt, do it now
	if (global->execution_state == EXECUTION_STATE_STOPPED)
	{
		bool firststop = true;

		// load comments if we haven't yet
		if (!global->comments_loaded)
		{
			debug_comment_load(m_device.machine());
			global->comments_loaded = true;
		}

		// reset any transient state
		reset_transient_flags(m_device.machine());
		global->breakcpu = NULL;

		// remember the last visible CPU in the debugger
		global->visiblecpu = &m_device;

		// update all views
		machine.debug_view().update_all();
		debugger_refresh_display(m_device.machine());

		// wait for the debugger; during this time, disable sound output
		m_device.machine().sound().debugger_mute(true);
		while (global->execution_state == EXECUTION_STATE_STOPPED)
		{
			// flush any pending updates before waiting again
			machine.debug_view().flush_osd_updates();

			// clear the memory modified flag and wait
			global->memory_modified = false;
			if (machine.debug_flags & DEBUG_FLAG_OSD_ENABLED)
				machine.osd().wait_for_debugger(m_device, firststop);
			else if (machine.debug_flags & DEBUG_FLAG_ENABLED)
				debugint_wait_for_debugger(m_device, firststop);
			firststop = false;

			// if something modified memory, update the screen
			if (global->memory_modified)
			{
				machine.debug_view().update_all(DVT_DISASSEMBLY);
				debugger_refresh_display(m_device.machine());
			}

			// check for commands in the source file
			process_source_file(m_device.machine());

			// if an event got scheduled, resume
			if (machine.scheduled_event_pending())
				global->execution_state = EXECUTION_STATE_RUNNING;
		}
		m_device.machine().sound().debugger_mute(false);

		// remember the last visible CPU in the debugger
		global->visiblecpu = &m_device;
	}

	// handle step out/over on the instruction we are about to execute
	if ((m_flags & (DEBUG_FLAG_STEPPING_OVER | DEBUG_FLAG_STEPPING_OUT)) != 0 && m_stepaddr == ~0)
		prepare_for_step_overout(pc());

	// no longer in debugger code
	global->within_instruction_hook = false;
}


//-------------------------------------------------
//  memory_read_hook - the memory system calls
//  this hook when watchpoints are enabled and a
//  memory read happens
//-------------------------------------------------

void device_debug::memory_read_hook(address_space &space, offs_t address, UINT64 mem_mask)
{
	// check watchpoints
	watchpoint_check(space, WATCHPOINT_READ, address, 0, mem_mask);

	// check hotspots
	if (m_hotspots != NULL)
		hotspot_check(space, address);
}


//-------------------------------------------------
//  memory_write_hook - the memory system calls
//  this hook when watchpoints are enabled and a
//  memory write happens
//-------------------------------------------------

void device_debug::memory_write_hook(address_space &space, offs_t address, UINT64 data, UINT64 mem_mask)
{
	watchpoint_check(space, WATCHPOINT_WRITE, address, data, mem_mask);
}


//-------------------------------------------------
//  set_instruction_hook - set a hook to be
//  called on each instruction for a given device
//-------------------------------------------------

void device_debug::set_instruction_hook(debug_instruction_hook_func hook)
{
	// set the hook and also the CPU's flag for fast knowledge of the hook
	m_instrhook = hook;
	if (hook != NULL)
		m_flags |= DEBUG_FLAG_HOOKED;
	else
		m_flags &= ~DEBUG_FLAG_HOOKED;
}


//-------------------------------------------------
//  disassemble - disassemble a line at a given
//  PC on a given device
//-------------------------------------------------

offs_t device_debug::disassemble(char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram) const
{
	offs_t result = 0;

	// check for disassembler override
	if (m_dasm_override != NULL)
		result = (*m_dasm_override)(m_device, buffer, pc, oprom, opram, 0);

	// if we have a disassembler, run it
	if (result == 0 && m_disasm != NULL)
		result = m_disasm->disassemble(buffer, pc, oprom, opram, 0);

	// make sure we get good results
	assert((result & DASMFLAG_LENGTHMASK) != 0);
#ifdef MAME_DEBUG
if (m_memory != NULL && m_disasm != NULL)
{
	address_space *space = m_memory->space(AS_PROGRAM);
	int bytes = space->address_to_byte(result & DASMFLAG_LENGTHMASK);
	assert(bytes >= m_disasm->min_opcode_bytes());
	assert(bytes <= m_disasm->max_opcode_bytes());
	(void) bytes; // appease compiler
}
#endif

	return result;
}


//-------------------------------------------------
//  ignore - ignore/observe a given device
//-------------------------------------------------

void device_debug::ignore(bool ignore)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	if (ignore)
		m_flags &= ~DEBUG_FLAG_OBSERVING;
	else
		m_flags |= DEBUG_FLAG_OBSERVING;

	if (&m_device == global->livecpu && ignore)
		go_next_device();
}


//-------------------------------------------------
//  single_step - single step the device past the
//  requested number of instructions
//-------------------------------------------------

void device_debug::single_step(int numsteps)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stepsleft = numsteps;
	m_stepaddr = ~0;
	m_flags |= DEBUG_FLAG_STEPPING;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  single_step_over - single step the device over
//  the requested number of instructions
//-------------------------------------------------

void device_debug::single_step_over(int numsteps)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stepsleft = numsteps;
	m_stepaddr = ~0;
	m_flags |= DEBUG_FLAG_STEPPING_OVER;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  single_step_out - single step the device
//  out of the current function
//-------------------------------------------------

void device_debug::single_step_out()
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stepsleft = 100;
	m_stepaddr = ~0;
	m_flags |= DEBUG_FLAG_STEPPING_OUT;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  go - execute the device until it hits the given
//  address
//-------------------------------------------------

void device_debug::go(offs_t targetpc)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stopaddr = targetpc;
	m_flags |= DEBUG_FLAG_STOP_PC;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  go_vblank - execute until the next VBLANK
//-------------------------------------------------

void device_debug::go_vblank()
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	global->vblank_occurred = false;
	m_flags |= DEBUG_FLAG_STOP_VBLANK;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  go_interrupt - execute until the specified
//  interrupt fires on the device
//-------------------------------------------------

void device_debug::go_interrupt(int irqline)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stopirq = irqline;
	m_flags |= DEBUG_FLAG_STOP_INTERRUPT;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  go_exception - execute until the specified
//  exception fires on the visible CPU
//-------------------------------------------------

void device_debug::go_exception(int exception)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stopexception = exception;
	m_flags |= DEBUG_FLAG_STOP_EXCEPTION;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  go_milliseconds - execute until the specified
//  delay elapses
//-------------------------------------------------

void device_debug::go_milliseconds(UINT64 milliseconds)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	m_stoptime = m_device.machine().time() + attotime::from_msec(milliseconds);
	m_flags |= DEBUG_FLAG_STOP_TIME;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  go_next_device - execute until we hit the next
//  device
//-------------------------------------------------

void device_debug::go_next_device()
{
	debugcpu_private *global = m_device.machine().debugcpu_data;

	assert(m_exec != NULL);

	global->m_stop_when_not_device = &m_device;
	global->execution_state = EXECUTION_STATE_RUNNING;
}


//-------------------------------------------------
//  halt_on_next_instruction - halt in the
//  debugger on the next instruction
//-------------------------------------------------

void device_debug::halt_on_next_instruction(const char *fmt, ...)
{
	debugcpu_private *global = m_device.machine().debugcpu_data;
	va_list arg;

	assert(m_exec != NULL);

	// if something is pending on this CPU already, ignore this request
	if (&m_device == global->breakcpu)
		return;

	// output the message to the console
	va_start(arg, fmt);
	debug_console_vprintf(m_device.machine(), fmt, arg);
	va_end(arg);

	// if we are live, stop now, otherwise note that we want to break there
	if (&m_device == global->livecpu)
	{
		global->execution_state = EXECUTION_STATE_STOPPED;
		if (global->livecpu != NULL)
			global->livecpu->debug()->compute_debug_flags();
	}
	else
		global->breakcpu = &m_device;
}


//-------------------------------------------------
//  breakpoint_set - set a new breakpoint,
//  returning its index
//-------------------------------------------------

int device_debug::breakpoint_set(offs_t address, const char *condition, const char *action)
{
	// allocate a new one
	breakpoint *bp = auto_alloc(m_device.machine(), breakpoint(m_symtable, m_device.machine().debugcpu_data->bpindex++, address, condition, action));

	// hook it into our list
	bp->m_next = m_bplist;
	m_bplist = bp;

	// update the flags and return the index
	breakpoint_update_flags();
	return bp->m_index;
}


//-------------------------------------------------
//  breakpoint_clear - clear a breakpoint by index,
//  returning true if we found it
//-------------------------------------------------

bool device_debug::breakpoint_clear(int index)
{
	// scan the list to see if we own this breakpoint
	for (breakpoint **bp = &m_bplist; *bp != NULL; bp = &(*bp)->m_next)
		if ((*bp)->m_index == index)
		{
			breakpoint *deleteme = *bp;
			*bp = deleteme->m_next;
			auto_free(m_device.machine(), deleteme);
			breakpoint_update_flags();
			return true;
		}

	// we don't own it, return false
	return false;
}


//-------------------------------------------------
//  breakpoint_clear_all - clear all breakpoints
//-------------------------------------------------

void device_debug::breakpoint_clear_all()
{
	// clear the head until we run out
	while (m_bplist != NULL)
		breakpoint_clear(m_bplist->index());
}


//-------------------------------------------------
//  breakpoint_enable - enable/disable a breakpoint
//  by index, returning true if we found it
//-------------------------------------------------

bool device_debug::breakpoint_enable(int index, bool enable)
{
	// scan the list to see if we own this breakpoint
	for (breakpoint *bp = m_bplist; bp != NULL; bp = bp->next())
		if (bp->m_index == index)
		{
			bp->m_enabled = enable;
			breakpoint_update_flags();
			return true;
		}

	// we don't own it, return false
	return false;
}


//-------------------------------------------------
//  breakpoint_enable_all - enable/disable all
//  breakpoints
//-------------------------------------------------

void device_debug::breakpoint_enable_all(bool enable)
{
	// apply the enable to all breakpoints we own
	for (breakpoint *bp = m_bplist; bp != NULL; bp = bp->next())
		breakpoint_enable(bp->index(), enable);
}


//-------------------------------------------------
//  watchpoint_set - set a new watchpoint,
//  returning its index
//-------------------------------------------------

int device_debug::watchpoint_set(address_space &space, int type, offs_t address, offs_t length, const char *condition, const char *action)
{
	assert(space.spacenum() < ARRAY_LENGTH(m_wplist));

	// allocate a new one
	watchpoint *wp = auto_alloc(m_device.machine(), watchpoint(m_symtable, m_device.machine().debugcpu_data->bpindex++, space, type, address, length, condition, action));

	// hook it into our list
	wp->m_next = m_wplist[space.spacenum()];
	m_wplist[space.spacenum()] = wp;

	// update the flags and return the index
	watchpoint_update_flags(wp->m_space);
	return wp->m_index;
}


//-------------------------------------------------
//  watchpoint_clear - clear a watchpoint by index,
//  returning true if we found it
//-------------------------------------------------

bool device_debug::watchpoint_clear(int index)
{
	// scan the list to see if we own this breakpoint
	for (address_spacenum spacenum = AS_0; spacenum < ARRAY_LENGTH(m_wplist); spacenum++)
		for (watchpoint **wp = &m_wplist[spacenum]; *wp != NULL; wp = &(*wp)->m_next)
			if ((*wp)->m_index == index)
			{
				watchpoint *deleteme = *wp;
				address_space &space = deleteme->m_space;
				*wp = deleteme->m_next;
				auto_free(m_device.machine(), deleteme);
				watchpoint_update_flags(space);
				return true;
			}

	// we don't own it, return false
	return false;
}


//-------------------------------------------------
//  watchpoint_clear_all - clear all watchpoints
//-------------------------------------------------

void device_debug::watchpoint_clear_all()
{
	// clear the head until we run out
	for (address_spacenum spacenum = AS_0; spacenum < ARRAY_LENGTH(m_wplist); spacenum++)
		while (m_wplist[spacenum] != NULL)
			watchpoint_clear(m_wplist[spacenum]->index());
}


//-------------------------------------------------
//  watchpoint_enable - enable/disable a watchpoint
//  by index, returning true if we found it
//-------------------------------------------------

bool device_debug::watchpoint_enable(int index, bool enable)
{
	// scan the list to see if we own this watchpoint
	for (address_spacenum spacenum = AS_0; spacenum < ARRAY_LENGTH(m_wplist); spacenum++)
		for (watchpoint *wp = m_wplist[spacenum]; wp != NULL; wp = wp->next())
			if (wp->m_index == index)
			{
				wp->m_enabled = enable;
				watchpoint_update_flags(wp->m_space);
				return true;
			}

	// we don't own it, return false
	return false;
}


//-------------------------------------------------
//  watchpoint_enable_all - enable/disable all
//  watchpoints
//-------------------------------------------------

void device_debug::watchpoint_enable_all(bool enable)
{
	// apply the enable to all watchpoints we own
	for (address_spacenum spacenum = AS_0; spacenum < ARRAY_LENGTH(m_wplist); spacenum++)
		for (watchpoint *wp = m_wplist[spacenum]; wp != NULL; wp = wp->next())
			watchpoint_enable(wp->index(), enable);
}


//-------------------------------------------------
//  hotspot_track - enable/disable tracking of
//  hotspots
//-------------------------------------------------

void device_debug::hotspot_track(int numspots, int threshhold)
{
	// if we already have tracking enabled, kill it
	auto_free(m_device.machine(), m_hotspots);
	m_hotspots = NULL;

	// only start tracking if we have a non-zero count
	if (numspots > 0)
	{
		// allocate memory for hotspots
		m_hotspots = auto_alloc_array(m_device.machine(), hotspot_entry, numspots);
		memset(m_hotspots, 0xff, sizeof(*m_hotspots) * numspots);

		// fill in the info
		m_hotspot_count = numspots;
		m_hotspot_threshhold = threshhold;
	}

	// update the watchpoint flags to include us
	if (m_memory != NULL && m_memory->space(AS_PROGRAM) != NULL)
		watchpoint_update_flags(*m_memory->space(AS_PROGRAM));
}


//-------------------------------------------------
//  history_pc - return an entry from the PC
//  history
//-------------------------------------------------

offs_t device_debug::history_pc(int index) const
{
	if (index > 0)
		index = 0;
	if (index <= -HISTORY_SIZE)
		index = -HISTORY_SIZE + 1;
	return m_pc_history[(m_pc_history_index + ARRAY_LENGTH(m_pc_history) - 1 + index) % ARRAY_LENGTH(m_pc_history)];
}


//-------------------------------------------------
//  comment_add - adds a comment to the list at
//  the given address
//-------------------------------------------------

void device_debug::comment_add(offs_t addr, const char *comment, rgb_t color)
{
	// create a new item for the list
	UINT32 crc = compute_opcode_crc32(addr);
	dasm_comment *newcomment = auto_alloc(m_device.machine(), dasm_comment(comment, addr, color, crc));

	// figure out where to insert it
	dasm_comment *prev = NULL;
	dasm_comment *curr;
	for (curr = m_comment_list.first(); curr != NULL; prev = curr, curr = curr->next())
		if (curr->m_address >= addr)
			break;

	// we could be the new head
	if (prev == NULL)
		m_comment_list.prepend(*newcomment);

	// or else we just insert ourselves here
	else
	{
		newcomment->m_next = prev->m_next;
		prev->m_next = newcomment;
	}

	// scan forward from here to delete any exact matches
	for ( ; curr != NULL && curr->m_address == addr; curr = curr->next())
		if (curr->m_crc == crc)
		{
			m_comment_list.remove(*curr);
			break;
		}

	// force an update
	m_comment_change++;
}


//-------------------------------------------------
//  comment_remove - removes a comment at the
//  given address with a matching CRC
//-------------------------------------------------

bool device_debug::comment_remove(offs_t addr)
{
	// scan the list for a match
	UINT32 crc = compute_opcode_crc32(addr);
	for (dasm_comment *curr = m_comment_list.first(); curr != NULL; curr = curr->next())
	{
		// if we're past the address, we failed
		if (curr->m_address > addr)
			break;

		// find an exact match
		if (curr->m_address == addr && curr->m_crc == crc)
		{
			// remove it and force an update
			m_comment_list.remove(*curr);
			m_comment_change++;
			return true;
		}
	}

	// failure is an option
	return false;
}


//-------------------------------------------------
//  comment_text - return the text of a comment
//-------------------------------------------------

const char *device_debug::comment_text(offs_t addr) const
{
	// scan the list for a match
	UINT32 crc = compute_opcode_crc32(addr);
	for (dasm_comment *curr = m_comment_list.first(); curr != NULL; curr = curr->next())
	{
		// if we're past the address, we failed
		if (curr->m_address > addr)
			break;

		// find an exact match
		if (curr->m_address == addr && curr->m_crc == crc)
			return curr->m_text;
	}

	// failure is an option
	return NULL;
}


//-------------------------------------------------
//  comment_export - export the comments to the
//  given XML data node
//-------------------------------------------------

bool device_debug::comment_export(xml_data_node &curnode)
{
	// iterate through the comments
	astring crc_buf;
	for (dasm_comment *curr = m_comment_list.first(); curr != NULL; curr = curr->next())
	{
		xml_data_node *datanode = xml_add_child(&curnode, "comment", xml_normalize_string(curr->m_text));
		if (datanode == NULL)
			return false;
		xml_set_attribute_int(datanode, "address", curr->m_address);
		xml_set_attribute_int(datanode, "color", curr->m_color);
		crc_buf.printf("%08X", curr->m_crc);
		xml_set_attribute(datanode, "crc", crc_buf);
	}
	return true;
}


//-------------------------------------------------
//  comment_import - import the comments from the
//  given XML data node
//-------------------------------------------------

bool device_debug::comment_import(xml_data_node &cpunode)
{
	// iterate through nodes
	for (xml_data_node *datanode = xml_get_sibling(cpunode.child, "comment"); datanode; datanode = xml_get_sibling(datanode->next, "comment"))
	{
		// extract attributes
		offs_t address = xml_get_attribute_int(datanode, "address", 0);
		rgb_t color = xml_get_attribute_int(datanode, "color", 0);
		UINT32 crc;
		sscanf(xml_get_attribute_string(datanode, "crc", 0), "%08X", &crc);

		// add the new comment; we assume they were saved ordered
		m_comment_list.append(*auto_alloc(m_device.machine(), dasm_comment(datanode->value, address, color, crc)));
	}
	return true;
}


//-------------------------------------------------
//  comment_dump - logs comments to the error.log
//  at a given address
//-------------------------------------------------

void device_debug::comment_dump(offs_t addr)
{
	// determine the CRC at the given address (if valid)
	UINT32 crc = (addr == ~0) ? 0 : compute_opcode_crc32(addr);

	// dump everything that matches
	bool found = false;
	for (dasm_comment *curr = m_comment_list.first(); curr != NULL; curr = curr->next())
		if (addr == ~0 || (curr->m_address == addr && curr->m_crc == crc))
		{
			found = true;
			logerror("%08X %08X - %s\n", curr->m_address, curr->m_crc, curr->m_text.cstr());
		}

	// if nothing found, indicate as much
	if (!found)
		logerror("No comment exists for address : 0x%x\n", addr);
}


//-------------------------------------------------
//  compute_opcode_crc32 - determine the CRC of
//  the opcode bytes at the given address
//-------------------------------------------------

UINT32 device_debug::compute_opcode_crc32(offs_t address) const
{
	// no memory interface, just fail
	if (m_memory == NULL)
		return 0;

	// no program interface, just fail
	address_space *space = m_memory->space(AS_PROGRAM);
	if (space == NULL)
		return 0;

	// zero out the buffers
	UINT8 opbuf[64], argbuf[64];
	memset(opbuf, 0x00, sizeof(opbuf));
	memset(argbuf, 0x00, sizeof(argbuf));

	// fetch the bytes up to the maximum
	int maxbytes = m_disasm->max_opcode_bytes();
	for (int index = 0; index < maxbytes; index++)
	{
		opbuf[index] = debug_read_opcode(space, address + index, 1, false);
		argbuf[index] = debug_read_opcode(space, address + index, 1, true);
	}

	// disassemble and then convert to bytes
	char buff[256];
	int numbytes = disassemble(buff, address & space->logaddrmask(), opbuf, argbuf) & DASMFLAG_LENGTHMASK;
	numbytes = space->address_to_byte(numbytes);

	// return a CRC of the resulting bytes
	return crc32(0, argbuf, numbytes);
}


//-------------------------------------------------
//  trace - trace execution of a given device
//-------------------------------------------------

void device_debug::trace(FILE *file, bool trace_over, const char *action)
{
	// delete any existing tracers
	auto_free(m_device.machine(), m_trace);
	m_trace = NULL;

	// if we have a new file, make a new tracer
	if (file != NULL)
		m_trace = auto_alloc(m_device.machine(), tracer(*this, *file, trace_over, action));
}


//-------------------------------------------------
//  trace_printf - output data into the given
//  device's tracefile, if tracing
//-------------------------------------------------

void device_debug::trace_printf(const char *fmt, ...)
{
	if (m_trace != NULL)
	{
		va_list va;
		va_start(va, fmt);
		m_trace->vprintf(fmt, va);
		va_end(va);
	}
}


//-------------------------------------------------
//  compute_debug_flags - compute the global
//  debug flags for optimal efficiency
//-------------------------------------------------

void device_debug::compute_debug_flags()
{
	running_machine &machine = m_device.machine();
	debugcpu_private *global = machine.debugcpu_data;

	// clear out global flags by default, keep DEBUG_FLAG_OSD_ENABLED
	machine.debug_flags &= DEBUG_FLAG_OSD_ENABLED;
	machine.debug_flags |= DEBUG_FLAG_ENABLED;

	// if we are ignoring this CPU, or if events are pending, we're done
	if ((m_flags & DEBUG_FLAG_OBSERVING) == 0 || machine.scheduled_event_pending() || machine.save_or_load_pending())
		return;

	// if we're stopped, keep calling the hook
	if (global->execution_state == EXECUTION_STATE_STOPPED)
		machine.debug_flags |= DEBUG_FLAG_CALL_HOOK;

	// if we're tracking history, or we're hooked, or stepping, or stopping at a breakpoint
	// make sure we call the hook
	if ((m_flags & (DEBUG_FLAG_HISTORY | DEBUG_FLAG_HOOKED | DEBUG_FLAG_STEPPING_ANY | DEBUG_FLAG_STOP_PC | DEBUG_FLAG_LIVE_BP)) != 0)
		machine.debug_flags |= DEBUG_FLAG_CALL_HOOK;

	// also call if we are tracing
	if (m_trace != NULL)
		machine.debug_flags |= DEBUG_FLAG_CALL_HOOK;

	// if we are stopping at a particular time and that time is within the current timeslice, we need to be called
	if ((m_flags & DEBUG_FLAG_STOP_TIME) && m_endexectime <= m_stoptime)
		machine.debug_flags |= DEBUG_FLAG_CALL_HOOK;
}


//-------------------------------------------------
//  prepare_for_step_overout - prepare things for
//  stepping over an instruction
//-------------------------------------------------

void device_debug::prepare_for_step_overout(offs_t pc)
{
	// disassemble the current instruction and get the flags
	astring dasmbuffer;
	offs_t dasmresult = dasm_wrapped(dasmbuffer, pc);

	// if flags are supported and it's a call-style opcode, set a temp breakpoint after that instruction
	if ((dasmresult & DASMFLAG_SUPPORTED) != 0 && (dasmresult & DASMFLAG_STEP_OVER) != 0)
	{
		int extraskip = (dasmresult & DASMFLAG_OVERINSTMASK) >> DASMFLAG_OVERINSTSHIFT;
		pc += dasmresult & DASMFLAG_LENGTHMASK;

		// if we need to skip additional instructions, advance as requested
		while (extraskip-- > 0)
			pc += dasm_wrapped(dasmbuffer, pc) & DASMFLAG_LENGTHMASK;
		m_stepaddr = pc;
	}

	// if we're stepping out and this isn't a step out instruction, reset the steps until stop to a high number
	if ((m_flags & DEBUG_FLAG_STEPPING_OUT) != 0)
	{
		if ((dasmresult & DASMFLAG_SUPPORTED) != 0 && (dasmresult & DASMFLAG_STEP_OUT) == 0)
			m_stepsleft = 100;
		else
			m_stepsleft = 1;
	}
}


//-------------------------------------------------
//  breakpoint_update_flags - update the device's
//  breakpoint flags
//-------------------------------------------------

void device_debug::breakpoint_update_flags()
{
	// see if there are any enabled breakpoints
	m_flags &= ~DEBUG_FLAG_LIVE_BP;
	for (breakpoint *bp = m_bplist; bp != NULL; bp = bp->m_next)
		if (bp->m_enabled)
		{
			m_flags |= DEBUG_FLAG_LIVE_BP;
			break;
		}

	// push the flags out globally
	debugcpu_private *global = m_device.machine().debugcpu_data;
	if (global->livecpu != NULL)
		global->livecpu->debug()->compute_debug_flags();
}


//-------------------------------------------------
//  breakpoint_check - check the breakpoints for
//  a given device
//-------------------------------------------------

void device_debug::breakpoint_check(offs_t pc)
{
	// see if we match
	for (breakpoint *bp = m_bplist; bp != NULL; bp = bp->m_next)
		if (bp->hit(pc))
		{
			// halt in the debugger by default
			debugcpu_private *global = m_device.machine().debugcpu_data;
			global->execution_state = EXECUTION_STATE_STOPPED;

			// if we hit, evaluate the action
			if (bp->m_action)
				debug_console_execute_command(m_device.machine(), bp->m_action, 0);

			// print a notification, unless the action made us go again
			if (global->execution_state == EXECUTION_STATE_STOPPED)
				debug_console_printf(m_device.machine(), "Stopped at breakpoint %X\n", bp->m_index);
			break;
		}
}


//-------------------------------------------------
//  watchpoint_update_flags - update the device's
//  watchpoint flags
//-------------------------------------------------

void device_debug::watchpoint_update_flags(address_space &space)
{
	// if hotspots are enabled, turn on all reads
	bool enableread = false;
	if (m_hotspots != NULL)
		enableread = true;

	// see if there are any enabled breakpoints
	bool enablewrite = false;
	for (watchpoint *wp = m_wplist[space.spacenum()]; wp != NULL; wp = wp->m_next)
		if (wp->m_enabled)
		{
			if (wp->m_type & WATCHPOINT_READ)
				enableread = true;
			if (wp->m_type & WATCHPOINT_WRITE)
				enablewrite = true;
		}

	// push the flags out globally
	space.enable_read_watchpoints(enableread);
	space.enable_write_watchpoints(enablewrite);
}


//-------------------------------------------------
//  watchpoint_check - check the watchpoints
//  for a given CPU and address space
//-------------------------------------------------

void device_debug::watchpoint_check(address_space &space, int type, offs_t address, UINT64 value_to_write, UINT64 mem_mask)
{
	debugcpu_private *global = space.machine().debugcpu_data;

	// if we're within debugger code, don't stop
	if (global->within_instruction_hook || global->debugger_access)
		return;
	global->within_instruction_hook = true;

	// adjust address, size & value_to_write based on mem_mask.
	offs_t size = 0;
	if (mem_mask != 0)
	{
		int bus_size = space.data_width() / 8;
		int address_offset = 0;

		while (address_offset < bus_size && (mem_mask & 0xff) == 0)
		{
			address_offset++;
			value_to_write >>= 8;
			mem_mask >>= 8;
		}

		while (mem_mask != 0)
		{
			size++;
			mem_mask >>= 8;
		}

		if (space.endianness() == ENDIANNESS_LITTLE)
			address += address_offset;
		else
			address += bus_size - size - address_offset;
	}

	// if we are a write watchpoint, stash the value that will be written
	global->wpaddr = address;
	if (type & WATCHPOINT_WRITE)
		global->wpdata = value_to_write;

	// see if we match
	for (watchpoint *wp = m_wplist[space.spacenum()]; wp != NULL; wp = wp->m_next)
		if (wp->hit(type, address, size))
		{
			// halt in the debugger by default
			global->execution_state = EXECUTION_STATE_STOPPED;

			// if we hit, evaluate the action
			if (wp->m_action)
				debug_console_execute_command(space.machine(), wp->m_action, 0);

			// print a notification, unless the action made us go again
			if (global->execution_state == EXECUTION_STATE_STOPPED)
			{
				static const char *const sizes[] =
				{
					"0bytes", "byte", "word", "3bytes", "dword", "5bytes", "6bytes", "7bytes", "qword"
				};
				offs_t pc = (space.device().debug()->m_state != NULL) ? space.device().debug()->m_state->pc() : 0;
				astring buffer;

				if (type & WATCHPOINT_WRITE)
				{
					buffer.printf("Stopped at watchpoint %X writing %s to %08X (PC=%X)", wp->m_index, sizes[size], space.byte_to_address(address), pc);
					if (value_to_write >> 32)
						buffer.catprintf(" (data=%X%08X)", (UINT32)(value_to_write >> 32), (UINT32)value_to_write);
					else
						buffer.catprintf(" (data=%X)", (UINT32)value_to_write);
				}
				else
					buffer.printf("Stopped at watchpoint %X reading %s from %08X (PC=%X)", wp->m_index, sizes[size], space.byte_to_address(address), pc);
				debug_console_printf(space.machine(), "%s\n", buffer.cstr());
				space.device().debug()->compute_debug_flags();
			}
			break;
		}

	global->within_instruction_hook = false;
}


//-------------------------------------------------
//  hotspot_check - check for hotspots on a
//  memory read access
//-------------------------------------------------

void device_debug::hotspot_check(address_space &space, offs_t address)
{
	offs_t curpc = pc();

	// see if we have a match in our list
	int hotindex;
	for (hotindex = 0; hotindex < m_hotspot_count; hotindex++)
		if (m_hotspots[hotindex].m_access == address && m_hotspots[hotindex].m_pc == curpc && m_hotspots[hotindex].m_space == &space)
			break;

	// if we didn't find any, make a new entry
	if (hotindex == m_hotspot_count)
	{
		// if the bottom of the list is over the threshhold, print it
		hotspot_entry &spot = m_hotspots[m_hotspot_count - 1];
		if (spot.m_count > m_hotspot_threshhold)
			debug_console_printf(space.machine(), "Hotspot @ %s %08X (PC=%08X) hit %d times (fell off bottom)\n", space.name(), spot.m_access, spot.m_pc, spot.m_count);

		// move everything else down and insert this one at the top
		memmove(&m_hotspots[1], &m_hotspots[0], sizeof(m_hotspots[0]) * (m_hotspot_count - 1));
		m_hotspots[0].m_access = address;
		m_hotspots[0].m_pc = curpc;
		m_hotspots[0].m_space = &space;
		m_hotspots[0].m_count = 1;
	}

	// if we did find one, increase the count and move it to the top
	else
	{
		m_hotspots[hotindex].m_count++;
		if (hotindex != 0)
		{
			hotspot_entry temp = m_hotspots[hotindex];
			memmove(&m_hotspots[1], &m_hotspots[0], sizeof(m_hotspots[0]) * hotindex);
			m_hotspots[0] = temp;
		}
	}
}


//-------------------------------------------------
//  dasm_wrapped - wraps calls to the disassembler
//  by fetching the opcode bytes to a temporary
//  buffer and then disassembling them
//-------------------------------------------------

UINT32 device_debug::dasm_wrapped(astring &buffer, offs_t pc)
{
	assert(m_memory != NULL && m_disasm != NULL);

	// determine the adjusted PC
	address_space *space = m_memory->space(AS_PROGRAM);
	offs_t pcbyte = space->address_to_byte(pc) & space->bytemask();

	// fetch the bytes up to the maximum
	UINT8 opbuf[64], argbuf[64];
	int maxbytes = max_opcode_bytes();
	for (int numbytes = 0; numbytes < maxbytes; numbytes++)
	{
		opbuf[numbytes] = debug_read_opcode(space, pcbyte + numbytes, 1, false);
		argbuf[numbytes] = debug_read_opcode(space, pcbyte + numbytes, 1, true);
	}

	// disassemble to our buffer
	return disassemble(buffer.stringbuffer(200), pc, opbuf, argbuf);
}


//-------------------------------------------------
//  get_current_pc - getter callback for a device's
//  current instruction pointer
//-------------------------------------------------

UINT64 device_debug::get_current_pc(symbol_table &table, void *ref)
{
	device_t *device = reinterpret_cast<device_t *>(table.globalref());
	return device->debug()->pc();
}


//-------------------------------------------------
//  get_cycles - getter callback for the
//  'cycles' symbol
//-------------------------------------------------

UINT64 device_debug::get_cycles(symbol_table &table, void *ref)
{
	device_t *device = reinterpret_cast<device_t *>(table.globalref());
	return device->debug()->m_exec->cycles_remaining();
}


//-------------------------------------------------
//  get_totalcycles - getter callback for the
//  'totalcycles' symbol
//-------------------------------------------------

UINT64 device_debug::get_totalcycles(symbol_table &table, void *ref)
{
	device_t *device = reinterpret_cast<device_t *>(table.globalref());
	return device->debug()->m_exec->total_cycles();
}


//-------------------------------------------------
//  get_logunmap - getter callback for the logumap
//  symbols
//-------------------------------------------------

UINT64 device_debug::get_logunmap(symbol_table &table, void *ref)
{
	address_space *space = reinterpret_cast<address_space *>(table.globalref());
	return space->log_unmap();
}


//-------------------------------------------------
//  set_logunmap - setter callback for the logumap
//  symbols
//-------------------------------------------------

void device_debug::set_logunmap(symbol_table &table, void *ref, UINT64 value)
{
	address_space *space = reinterpret_cast<address_space *>(table.globalref());
	space->set_log_unmap(value ? true : false);
}


//-------------------------------------------------
//  get_state - getter callback for a device's
//  state symbols
//-------------------------------------------------

UINT64 device_debug::get_state(symbol_table &table, void *ref)
{
	device_t *device = reinterpret_cast<device_t *>(table.globalref());
	return device->debug()->m_state->state(reinterpret_cast<FPTR>(ref));
}


//-------------------------------------------------
//  set_state - setter callback for a device's
//  state symbols
//-------------------------------------------------

void device_debug::set_state(symbol_table &table, void *ref, UINT64 value)
{
	device_t *device = reinterpret_cast<device_t *>(table.globalref());
	device->debug()->m_state->set_state(reinterpret_cast<FPTR>(ref), value);
}



//**************************************************************************
//  DEBUG BREAKPOINT
//**************************************************************************

//-------------------------------------------------
//  breakpoint - constructor
//-------------------------------------------------

device_debug::breakpoint::breakpoint(symbol_table &symbols, int index, offs_t address, const char *condition, const char *action)
	: m_next(NULL),
	  m_index(index),
	  m_enabled(true),
	  m_address(address),
	  m_condition(&symbols, (condition != NULL) ? condition : "1"),
	  m_action((action != NULL) ? action : "")
{
}


//-------------------------------------------------
//  hit - detect a hit
//-------------------------------------------------

bool device_debug::breakpoint::hit(offs_t pc)
{
	// don't hit if disabled
	if (!m_enabled)
		return false;

	// must match our address
	if (m_address != pc)
		return false;

	// must satisfy the condition
	if (!m_condition.is_empty())
	{
		try
		{
			return (m_condition.execute() != 0);
		}
		catch (expression_error &)
		{
			return false;
		}
	}

	return true;
}



//**************************************************************************
//  DEBUG WATCHPOINT
//**************************************************************************

//-------------------------------------------------
//  watchpoint - constructor
//-------------------------------------------------

device_debug::watchpoint::watchpoint(symbol_table &symbols, int index, address_space &space, int type, offs_t address, offs_t length, const char *condition, const char *action)
	: m_next(NULL),
	  m_space(space),
	  m_index(index),
	  m_enabled(true),
	  m_type(type),
	  m_address(space.address_to_byte(address) & space.bytemask()),
	  m_length(space.address_to_byte(length)),
	  m_condition(&symbols, (condition != NULL) ? condition : "1"),
	  m_action((action != NULL) ? action : "")
{
}


//-------------------------------------------------
//  hit - detect a hit
//-------------------------------------------------

bool device_debug::watchpoint::hit(int type, offs_t address, int size)
{
	// don't hit if disabled
	if (!m_enabled)
		return false;

	// must match the type
	if ((m_type & type) == 0)
		return false;

	// must match our address
	if (address + size <= m_address || address >= m_address + m_length)
		return false;

	// must satisfy the condition
	if (!m_condition.is_empty())
	{
		try
		{
			return (m_condition.execute() != 0);
		}
		catch (expression_error &)
		{
			return false;
		}
	}
	return true;
}



//**************************************************************************
//  TRACER
//**************************************************************************

//-------------------------------------------------
//  tracer - constructor
//-------------------------------------------------

device_debug::tracer::tracer(device_debug &debug, FILE &file, bool trace_over, const char *action)
	: m_debug(debug),
	  m_file(file),
	  m_action((action != NULL) ? action : ""),
	  m_loops(0),
	  m_nextdex(0),
	  m_trace_over(trace_over),
	  m_trace_over_target(~0)
{
	memset(m_history, 0, sizeof(m_history));
}


//-------------------------------------------------
//  ~tracer - destructor
//-------------------------------------------------

device_debug::tracer::~tracer()
{
	// make sure we close the file if we can
	fclose(&m_file);
}


//-------------------------------------------------
//  update - log to the tracefile the data for a
//  given instruction
//-------------------------------------------------

void device_debug::tracer::update(offs_t pc)
{
	// are we in trace over mode and in a subroutine?
	if (m_trace_over && m_trace_over_target != ~0)
	{
		if (m_trace_over_target != pc)
			return;
		m_trace_over_target = ~0;
	}

	// check for a loop condition
	int count = 0;
	for (int index = 0; index < ARRAY_LENGTH(m_history); index++)
		if (m_history[index] == pc)
			count++;

	// if more than 1 hit, just up the loop count and get out
	if (count > 1)
	{
		m_loops++;
		return;
	}

	// if we just finished looping, indicate as much
	if (m_loops != 0)
		fprintf(&m_file, "\n   (loops for %d instructions)\n\n", m_loops);
	m_loops = 0;

	// execute any trace actions first
	if (m_action)
		debug_console_execute_command(m_debug.m_device.machine(), m_action, 0);

	// print the address
	astring buffer;
	int logaddrchars = m_debug.logaddrchars();
	buffer.printf("%0*X: ", logaddrchars, pc);

	// print the disassembly
	astring dasm;
	offs_t dasmresult = m_debug.dasm_wrapped(dasm, pc);
	buffer.cat(dasm);

	// output the result
	fprintf(&m_file, "%s\n", buffer.cstr());

	// do we need to step the trace over this instruction?
	if (m_trace_over && (dasmresult & DASMFLAG_SUPPORTED) != 0 && (dasmresult & DASMFLAG_STEP_OVER) != 0)
	{
		int extraskip = (dasmresult & DASMFLAG_OVERINSTMASK) >> DASMFLAG_OVERINSTSHIFT;
		offs_t trace_over_target = pc + (dasmresult & DASMFLAG_LENGTHMASK);

		// if we need to skip additional instructions, advance as requested
		while (extraskip-- > 0)
			trace_over_target += m_debug.dasm_wrapped(dasm, trace_over_target) & DASMFLAG_LENGTHMASK;

		m_trace_over_target = trace_over_target;
	}

	// log this PC
	m_nextdex = (m_nextdex + 1) % TRACE_LOOPS;
	m_history[m_nextdex] = pc;
}


//-------------------------------------------------
//  vprintf - generic print to the trace file
//-------------------------------------------------

void device_debug::tracer::vprintf(const char *format, va_list va)
{
	// pass through to the file
	vfprintf(&m_file, format, va);
}


//-------------------------------------------------
//  flush - flush any pending changes to the trace
//  file
//-------------------------------------------------

void device_debug::tracer::flush()
{
	fflush(&m_file);
}


//-------------------------------------------------
//  dasm_comment - constructor
//-------------------------------------------------

device_debug::dasm_comment::dasm_comment(const char *text, offs_t address, rgb_t color, UINT32 crc)
	: m_next(NULL),
	  m_address(address),
	  m_color(color),
	  m_crc(crc),
	  m_text(text)
{
}
