// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************

    validity.c

    Validity checks on internal data structures.

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

#include "emu.h"
#include "validity.h"
#include "emuopts.h"
#include <ctype.h>


//**************************************************************************
//  COMPILE-TIME VALIDATION
//**************************************************************************

// if the following lines error during compile, your PTR64 switch is set incorrectly in the makefile
#ifdef PTR64
UINT8 your_ptr64_flag_is_wrong[(int)(sizeof(void *) - 7)];
#else
UINT8 your_ptr64_flag_is_wrong[(int)(5 - sizeof(void *))];
#endif



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

//**************************************************************************
//  INLINE FUNCTIONS
//**************************************************************************

//-------------------------------------------------
//  ioport_string_from_index - return an indexed
//  string from the I/O port system
//-------------------------------------------------

inline const char *validity_checker::ioport_string_from_index(UINT32 index)
{
	return ioport_configurer::string_from_token((const char *)(FPTR)index);
}


//-------------------------------------------------
//  get_defstr_index - return the index of the
//  string assuming it is one of the default
//  strings
//-------------------------------------------------

inline int validity_checker::get_defstr_index(const char *string, bool suppress_error)
{
	// check for strings that should be DEF_STR
	int strindex = m_defstr_map.find(string);
	if (!suppress_error && strindex != 0 && string != ioport_string_from_index(strindex))
		osd_printf_error("Must use DEF_STR( %s )\n", string);
	return strindex;
}


//-------------------------------------------------
//  validate_tag - ensure that the given tag
//  meets the general requirements
//-------------------------------------------------

void validity_checker::validate_tag(const char *tag)
{
	// some common names that are now deprecated
	if (strcmp(tag, "main") == 0 || strcmp(tag, "audio") == 0 || strcmp(tag, "sound") == 0 || strcmp(tag, "left") == 0 || strcmp(tag, "right") == 0)
		osd_printf_error("Invalid generic tag '%s' used\n", tag);

	// scan for invalid characters
	static const char *validchars = "abcdefghijklmnopqrstuvwxyz0123456789_.:^$";
	for (const char *p = tag; *p != 0; p++)
	{
		// only lower-case permitted
		if (*p != tolower((UINT8)*p))
		{
			osd_printf_error("Tag '%s' contains upper-case characters\n", tag);
			break;
		}
		if (*p == ' ')
		{
			osd_printf_error("Tag '%s' contains spaces\n", tag);
			break;
		}
		if (strchr(validchars, *p) == NULL)
		{
			osd_printf_error("Tag '%s' contains invalid character '%c'\n",  tag, *p);
			break;
		}
	}

	// find the start of the final tag
	const char *begin = strrchr(tag, ':');
	if (begin == NULL)
		begin = tag;
	else
		begin += 1;

	// 0-length = bad
	if (*begin == 0)
		osd_printf_error("Found 0-length tag\n");

	// too short/too long = bad
	if (strlen(begin) < MIN_TAG_LENGTH)
		osd_printf_error("Tag '%s' is too short (must be at least %d characters)\n", tag, MIN_TAG_LENGTH);
	if (strlen(begin) > MAX_TAG_LENGTH)
		osd_printf_error("Tag '%s' is too long (must be less than %d characters)\n", tag, MAX_TAG_LENGTH);
}



//**************************************************************************
//  VALIDATION FUNCTIONS
//**************************************************************************

//-------------------------------------------------
//  validity_checker - constructor
//-------------------------------------------------

validity_checker::validity_checker(emu_options &options)
	: m_drivlist(options),
		m_errors(0),
		m_warnings(0),
		m_current_driver(NULL),
		m_current_config(NULL),
		m_current_device(NULL),
		m_current_ioport(NULL)
{
	// pre-populate the defstr map with all the default strings
	for (int strnum = 1; strnum < INPUT_STRING_COUNT; strnum++)
	{
		const char *string = ioport_string_from_index(strnum);
		if (string != NULL)
			m_defstr_map.add(string, strnum, false);
	}
}

//-------------------------------------------------
//  validity_checker - destructor
//-------------------------------------------------

validity_checker::~validity_checker()
{
	validate_end();
}

//-------------------------------------------------
//  check_driver - check a single driver
//-------------------------------------------------

void validity_checker::check_driver(const game_driver &driver)
{
	// simply validate the one driver
	validate_begin();
	validate_one(driver);
	validate_end();
}


//-------------------------------------------------
//  check_shared_source - check all drivers that
//  share the same source file as the given driver
//-------------------------------------------------

void validity_checker::check_shared_source(const game_driver &driver)
{
	// initialize
	validate_begin();

	// then iterate over all drivers and check the ones that share the same source file
	m_drivlist.reset();
	while (m_drivlist.next())
		if (strcmp(driver.source_file, m_drivlist.driver().source_file) == 0)
			validate_one(m_drivlist.driver());

	// cleanup
	validate_end();
}


//-------------------------------------------------
//  check_all - check all drivers
//-------------------------------------------------

void validity_checker::check_all()
{
	// start by checking core stuff
	validate_begin();
	validate_core();
	validate_inlines();

	// if we had warnings or errors, output
	if (m_errors > 0 || m_warnings > 0)
	{
		astring tempstr;
		output_via_delegate(m_saved_error_output, "Core: %d errors, %d warnings\n", m_errors, m_warnings);
		if (m_errors > 0)
		{
			m_error_text.replace("\n", "\n   ");
			output_via_delegate(m_saved_error_output, "Errors:\n   %s", m_error_text.cstr());
		}
		if (m_warnings > 0)
		{
			m_warning_text.replace("\n", "\n   ");
			output_via_delegate(m_saved_error_output, "Warnings:\n   %s", m_warning_text.cstr());
		}
		output_via_delegate(m_saved_error_output, "\n");
	}

	// then iterate over all drivers and check them
	m_drivlist.reset();
	while (m_drivlist.next())
		validate_one(m_drivlist.driver());

	// cleanup
	validate_end();
}


//-------------------------------------------------
//  validate_begin - prepare for validation by
//  taking over the output callbacks and resetting
//  our internal state
//-------------------------------------------------

void validity_checker::validate_begin()
{
	// take over error and warning outputs
	m_saved_error_output = osd_set_output_channel(OSD_OUTPUT_CHANNEL_ERROR, output_delegate(FUNC(validity_checker::error_output), this));
	m_saved_warning_output = osd_set_output_channel(OSD_OUTPUT_CHANNEL_WARNING, output_delegate(FUNC(validity_checker::warning_output), this));

	// reset all our maps
	m_names_map.reset();
	m_descriptions_map.reset();
	m_roms_map.reset();
	m_defstr_map.reset();
	m_region_map.reset();

	// reset internal state
	m_errors = 0;
	m_warnings = 0;
	m_already_checked.reset();
}


//-------------------------------------------------
//  validate_end - restore output callbacks and
//  clean up
//-------------------------------------------------

void validity_checker::validate_end()
{
	// restore the original output callbacks
	osd_set_output_channel(OSD_OUTPUT_CHANNEL_ERROR, m_saved_error_output);
	osd_set_output_channel(OSD_OUTPUT_CHANNEL_WARNING, m_saved_warning_output);
}


//-------------------------------------------------
//  validate_drivers - master validity checker
//-------------------------------------------------

void validity_checker::validate_one(const game_driver &driver)
{
	// set the current driver
	m_current_driver = &driver;
	m_current_config = NULL;
	m_current_device = NULL;
	m_current_ioport = NULL;
	m_region_map.reset();

	// reset error/warning state
	int start_errors = m_errors;
	int start_warnings = m_warnings;
	m_error_text.reset();
	m_warning_text.reset();

	// wrap in try/except to catch fatalerrors
	try
	{
		machine_config config(driver, m_drivlist.options());
		m_current_config = &config;
		validate_driver();
		validate_roms();
		validate_inputs();
		validate_devices();
	}
	catch (emu_fatalerror &err)
	{
		osd_printf_error("Fatal error %s", err.string());
	}
	m_current_config = NULL;

	// if we had warnings or errors, output
	if (m_errors > start_errors || m_warnings > start_warnings)
	{
		astring tempstr;
		output_via_delegate(m_saved_error_output, "Driver %s (file %s): %d errors, %d warnings\n", driver.name, core_filename_extract_base(tempstr, driver.source_file).cstr(), m_errors - start_errors, m_warnings - start_warnings);
		if (m_errors > start_errors)
		{
			m_error_text.replace("\n", "\n   ");
			output_via_delegate(m_saved_error_output, "Errors:\n   %s", m_error_text.cstr());
		}
		if (m_warnings > start_warnings)
		{
			m_warning_text.replace("\n", "\n   ");
			output_via_delegate(m_saved_error_output, "Warnings:\n   %s", m_warning_text.cstr());
		}
		output_via_delegate(m_saved_error_output, "\n");
	}

	// reset the driver/device
	m_current_driver = NULL;
	m_current_config = NULL;
	m_current_device = NULL;
	m_current_ioport = NULL;
}


//-------------------------------------------------
//  validate_core - validate core internal systems
//-------------------------------------------------

void validity_checker::validate_core()
{
	// basic system checks
	UINT8 a = 0xff;
	UINT8 b = a + 1;
	if (b > a) osd_printf_error("UINT8 must be 8 bits\n");

	// check size of core integer types
	if (sizeof(INT8)   != 1) osd_printf_error("INT8 must be 8 bits\n");
	if (sizeof(UINT8)  != 1) osd_printf_error("UINT8 must be 8 bits\n");
	if (sizeof(INT16)  != 2) osd_printf_error("INT16 must be 16 bits\n");
	if (sizeof(UINT16) != 2) osd_printf_error("UINT16 must be 16 bits\n");
	if (sizeof(INT32)  != 4) osd_printf_error("INT32 must be 32 bits\n");
	if (sizeof(UINT32) != 4) osd_printf_error("UINT32 must be 32 bits\n");
	if (sizeof(INT64)  != 8) osd_printf_error("INT64 must be 64 bits\n");
	if (sizeof(UINT64) != 8) osd_printf_error("UINT64 must be 64 bits\n");

	// check pointer size
#ifdef PTR64
	if (sizeof(void *) != 8) osd_printf_error("PTR64 flag enabled, but was compiled for 32-bit target\n");
#else
	if (sizeof(void *) != 4) osd_printf_error("PTR64 flag not enabled, but was compiled for 64-bit target\n");
#endif

	// TODO: check if this is actually working
	// check endianness definition
	UINT16 lsbtest = 0;
	*(UINT8 *)&lsbtest = 0xff;
#ifdef LSB_FIRST
	if (lsbtest == 0xff00) osd_printf_error("LSB_FIRST specified, but running on a big-endian machine\n");
#else
	if (lsbtest == 0x00ff) osd_printf_error("LSB_FIRST not specified, but running on a little-endian machine\n");
#endif
}


//-------------------------------------------------
//  validate_inlines - validate inline function
//  behaviors
//-------------------------------------------------

void validity_checker::validate_inlines()
{
#undef rand
	volatile UINT64 testu64a = rand() ^ (rand() << 15) ^ ((UINT64)rand() << 30) ^ ((UINT64)rand() << 45);
	volatile INT64 testi64a = rand() ^ (rand() << 15) ^ ((INT64)rand() << 30) ^ ((INT64)rand() << 45);
#ifdef PTR64
	volatile INT64 testi64b = rand() ^ (rand() << 15) ^ ((INT64)rand() << 30) ^ ((INT64)rand() << 45);
#endif
	volatile UINT32 testu32a = rand() ^ (rand() << 15);
	volatile UINT32 testu32b = rand() ^ (rand() << 15);
	volatile INT32 testi32a = rand() ^ (rand() << 15);
	volatile INT32 testi32b = rand() ^ (rand() << 15);
	INT32 resulti32, expectedi32;
	UINT32 resultu32, expectedu32;
	INT64 resulti64, expectedi64;
	UINT64 resultu64, expectedu64;
	INT32 remainder, expremainder;
	UINT32 uremainder, expuremainder, bigu32 = 0xffffffff;

	// use only non-zero, positive numbers
	if (testu64a == 0) testu64a++;
	if (testi64a == 0) testi64a++;
	else if (testi64a < 0) testi64a = -testi64a;
#ifdef PTR64
	if (testi64b == 0) testi64b++;
	else if (testi64b < 0) testi64b = -testi64b;
#endif
	if (testu32a == 0) testu32a++;
	if (testu32b == 0) testu32b++;
	if (testi32a == 0) testi32a++;
	else if (testi32a < 0) testi32a = -testi32a;
	if (testi32b == 0) testi32b++;
	else if (testi32b < 0) testi32b = -testi32b;

	resulti64 = mul_32x32(testi32a, testi32b);
	expectedi64 = (INT64)testi32a * (INT64)testi32b;
	if (resulti64 != expectedi64)
		osd_printf_error("Error testing mul_32x32 (%08X x %08X) = %08X%08X (expected %08X%08X)\n", testi32a, testi32b, (UINT32)(resulti64 >> 32), (UINT32)resulti64, (UINT32)(expectedi64 >> 32), (UINT32)expectedi64);

	resultu64 = mulu_32x32(testu32a, testu32b);
	expectedu64 = (UINT64)testu32a * (UINT64)testu32b;
	if (resultu64 != expectedu64)
		osd_printf_error("Error testing mulu_32x32 (%08X x %08X) = %08X%08X (expected %08X%08X)\n", testu32a, testu32b, (UINT32)(resultu64 >> 32), (UINT32)resultu64, (UINT32)(expectedu64 >> 32), (UINT32)expectedu64);

	resulti32 = mul_32x32_hi(testi32a, testi32b);
	expectedi32 = ((INT64)testi32a * (INT64)testi32b) >> 32;
	if (resulti32 != expectedi32)
		osd_printf_error("Error testing mul_32x32_hi (%08X x %08X) = %08X (expected %08X)\n", testi32a, testi32b, resulti32, expectedi32);

	resultu32 = mulu_32x32_hi(testu32a, testu32b);
	expectedu32 = ((INT64)testu32a * (INT64)testu32b) >> 32;
	if (resultu32 != expectedu32)
		osd_printf_error("Error testing mulu_32x32_hi (%08X x %08X) = %08X (expected %08X)\n", testu32a, testu32b, resultu32, expectedu32);

	resulti32 = mul_32x32_shift(testi32a, testi32b, 7);
	expectedi32 = ((INT64)testi32a * (INT64)testi32b) >> 7;
	if (resulti32 != expectedi32)
		osd_printf_error("Error testing mul_32x32_shift (%08X x %08X) >> 7 = %08X (expected %08X)\n", testi32a, testi32b, resulti32, expectedi32);

	resultu32 = mulu_32x32_shift(testu32a, testu32b, 7);
	expectedu32 = ((INT64)testu32a * (INT64)testu32b) >> 7;
	if (resultu32 != expectedu32)
		osd_printf_error("Error testing mulu_32x32_shift (%08X x %08X) >> 7 = %08X (expected %08X)\n", testu32a, testu32b, resultu32, expectedu32);

	while ((INT64)testi32a * (INT64)0x7fffffff < testi64a)
		testi64a /= 2;
	while ((UINT64)testu32a * (UINT64)bigu32 < testu64a)
		testu64a /= 2;

	resulti32 = div_64x32(testi64a, testi32a);
	expectedi32 = testi64a / (INT64)testi32a;
	if (resulti32 != expectedi32)
		osd_printf_error("Error testing div_64x32 (%08X%08X / %08X) = %08X (expected %08X)\n", (UINT32)(testi64a >> 32), (UINT32)testi64a, testi32a, resulti32, expectedi32);

	resultu32 = divu_64x32(testu64a, testu32a);
	expectedu32 = testu64a / (UINT64)testu32a;
	if (resultu32 != expectedu32)
		osd_printf_error("Error testing divu_64x32 (%08X%08X / %08X) = %08X (expected %08X)\n", (UINT32)(testu64a >> 32), (UINT32)testu64a, testu32a, resultu32, expectedu32);

	resulti32 = div_64x32_rem(testi64a, testi32a, &remainder);
	expectedi32 = testi64a / (INT64)testi32a;
	expremainder = testi64a % (INT64)testi32a;
	if (resulti32 != expectedi32 || remainder != expremainder)
		osd_printf_error("Error testing div_64x32_rem (%08X%08X / %08X) = %08X,%08X (expected %08X,%08X)\n", (UINT32)(testi64a >> 32), (UINT32)testi64a, testi32a, resulti32, remainder, expectedi32, expremainder);

	resultu32 = divu_64x32_rem(testu64a, testu32a, &uremainder);
	expectedu32 = testu64a / (UINT64)testu32a;
	expuremainder = testu64a % (UINT64)testu32a;
	if (resultu32 != expectedu32 || uremainder != expuremainder)
		osd_printf_error("Error testing divu_64x32_rem (%08X%08X / %08X) = %08X,%08X (expected %08X,%08X)\n", (UINT32)(testu64a >> 32), (UINT32)testu64a, testu32a, resultu32, uremainder, expectedu32, expuremainder);

	resulti32 = mod_64x32(testi64a, testi32a);
	expectedi32 = testi64a % (INT64)testi32a;
	if (resulti32 != expectedi32)
		osd_printf_error("Error testing mod_64x32 (%08X%08X / %08X) = %08X (expected %08X)\n", (UINT32)(testi64a >> 32), (UINT32)testi64a, testi32a, resulti32, expectedi32);

	resultu32 = modu_64x32(testu64a, testu32a);
	expectedu32 = testu64a % (UINT64)testu32a;
	if (resultu32 != expectedu32)
		osd_printf_error("Error testing modu_64x32 (%08X%08X / %08X) = %08X (expected %08X)\n", (UINT32)(testu64a >> 32), (UINT32)testu64a, testu32a, resultu32, expectedu32);

	while ((INT64)testi32a * (INT64)0x7fffffff < ((INT32)testi64a << 3))
		testi64a /= 2;
	while ((UINT64)testu32a * (UINT64)0xffffffff < ((UINT32)testu64a << 3))
		testu64a /= 2;

	resulti32 = div_32x32_shift((INT32)testi64a, testi32a, 3);
	expectedi32 = ((INT64)(INT32)testi64a << 3) / (INT64)testi32a;
	if (resulti32 != expectedi32)
		osd_printf_error("Error testing div_32x32_shift (%08X << 3) / %08X = %08X (expected %08X)\n", (INT32)testi64a, testi32a, resulti32, expectedi32);

	resultu32 = divu_32x32_shift((UINT32)testu64a, testu32a, 3);
	expectedu32 = ((UINT64)(UINT32)testu64a << 3) / (UINT64)testu32a;
	if (resultu32 != expectedu32)
		osd_printf_error("Error testing divu_32x32_shift (%08X << 3) / %08X = %08X (expected %08X)\n", (UINT32)testu64a, testu32a, resultu32, expectedu32);

	if (fabs(recip_approx(100.0) - 0.01) > 0.0001)
		osd_printf_error("Error testing recip_approx\n");

	testi32a = (testi32a & 0x0000ffff) | 0x400000;
	if (count_leading_zeros(testi32a) != 9)
		osd_printf_error("Error testing count_leading_zeros\n");
	testi32a = (testi32a | 0xffff0000) & ~0x400000;
	if (count_leading_ones(testi32a) != 9)
		osd_printf_error("Error testing count_leading_ones\n");

	testi32b = testi32a;
	if (compare_exchange32(&testi32a, testi32b, 1000) != testi32b || testi32a != 1000)
		osd_printf_error("Error testing compare_exchange32\n");
#ifdef PTR64
	testi64b = testi64a;
	if (compare_exchange64(&testi64a, testi64b, 1000) != testi64b || testi64a != 1000)
		osd_printf_error("Error testing compare_exchange64\n");
#endif
	if (atomic_exchange32(&testi32a, testi32b) != 1000)
		osd_printf_error("Error testing atomic_exchange32\n");
	if (atomic_add32(&testi32a, 45) != testi32b + 45)
		osd_printf_error("Error testing atomic_add32\n");
	if (atomic_increment32(&testi32a) != testi32b + 46)
		osd_printf_error("Error testing atomic_increment32\n");
	if (atomic_decrement32(&testi32a) != testi32b + 45)
		osd_printf_error("Error testing atomic_decrement32\n");
}


//-------------------------------------------------
//  validate_driver - validate basic driver
//  information
//-------------------------------------------------

void validity_checker::validate_driver()
{
	// check for duplicate names
	astring tempstr;
	if (m_names_map.add(m_current_driver->name, m_current_driver, false) == TMERR_DUPLICATE)
	{
		const game_driver *match = m_names_map.find(m_current_driver->name);
		osd_printf_error("Driver name is a duplicate of %s(%s)\n", core_filename_extract_base(tempstr, match->source_file).cstr(), match->name);
	}

	// check for duplicate descriptions
	if (m_descriptions_map.add(m_current_driver->description, m_current_driver, false) == TMERR_DUPLICATE)
	{
		const game_driver *match = m_descriptions_map.find(m_current_driver->description);
		osd_printf_error("Driver description is a duplicate of %s(%s)\n", core_filename_extract_base(tempstr, match->source_file).cstr(), match->name);
	}

	// determine if we are a clone
	bool is_clone = (strcmp(m_current_driver->parent, "0") != 0);
	int clone_of = m_drivlist.clone(*m_current_driver);
	if (clone_of != -1 && (m_drivlist.driver(clone_of).flags & GAME_IS_BIOS_ROOT))
		is_clone = false;

	// if we have at least 100 drivers, validate the clone
	// (100 is arbitrary, but tries to avoid tiny.mak dependencies)
	if (driver_list::total() > 100 && clone_of == -1 && is_clone)
		osd_printf_error("Driver is a clone of nonexistant driver %s\n", m_current_driver->parent);

	// look for recursive cloning
	if (clone_of != -1 && &m_drivlist.driver(clone_of) == m_current_driver)
		osd_printf_error("Driver is a clone of itself\n");

	// look for clones that are too deep
	if (clone_of != -1 && (clone_of = m_drivlist.non_bios_clone(clone_of)) != -1)
		osd_printf_error("Driver is a clone of a clone\n");

	// make sure the driver name is not too long
	if (!is_clone && strlen(m_current_driver->name) > 8)
		osd_printf_error("Parent driver name must be 8 characters or less\n");
	if (is_clone && strlen(m_current_driver->name) > 16)
		osd_printf_error("Clone driver name must be 16 characters or less\n");

	// make sure the year is only digits, '?' or '+'
	for (const char *s = m_current_driver->year; *s != 0; s++)
		if (!isdigit((UINT8)*s) && *s != '?' && *s != '+')
		{
			osd_printf_error("Driver has an invalid year '%s'\n", m_current_driver->year);
			break;
		}

	// normalize driver->compatible_with
	const char *compatible_with = m_current_driver->compatible_with;
	if (compatible_with != NULL && strcmp(compatible_with, "0") == 0)
		compatible_with = NULL;

	// check for this driver being compatible with a non-existant driver
	if (compatible_with != NULL && m_drivlist.find(m_current_driver->compatible_with) == -1)
		osd_printf_error("Driver is listed as compatible with nonexistant driver %s\n", m_current_driver->compatible_with);

	// check for clone_of and compatible_with being specified at the same time
	if (m_drivlist.clone(*m_current_driver) != -1 && compatible_with != NULL)
		osd_printf_error("Driver cannot be both a clone and listed as compatible with another system\n");

	// find any recursive dependencies on the current driver
	for (int other_drv = m_drivlist.compatible_with(*m_current_driver); other_drv != -1; other_drv = m_drivlist.compatible_with(other_drv))
		if (m_current_driver == &m_drivlist.driver(other_drv))
		{
			osd_printf_error("Driver is recursively compatible with itself\n");
			break;
		}

	// make sure sound-less drivers are flagged
	sound_interface_iterator iter(m_current_config->root_device());
	if ((m_current_driver->flags & GAME_IS_BIOS_ROOT) == 0 && iter.first() == NULL && (m_current_driver->flags & GAME_NO_SOUND) == 0 && (m_current_driver->flags & GAME_NO_SOUND_HW) == 0)
		osd_printf_error("Driver is missing GAME_NO_SOUND flag\n");
}


//-------------------------------------------------
//  validate_roms - validate ROM definitions
//-------------------------------------------------

void validity_checker::validate_roms()
{
	// iterate, starting with the driver's ROMs and continuing with device ROMs
	device_iterator deviter(m_current_config->root_device());
	for (device_t *device = deviter.first(); device != NULL; device = deviter.next())
	{
		// for non-root devices, track the current device
		m_current_device = (device->owner() == NULL) ? NULL : device;

		// scan the ROM entries for this device
		const char *last_region_name = "???";
		const char *last_name = "???";
		UINT32 current_length = 0;
		int items_since_region = 1;
		int last_bios = 0;
		int total_files = 0;
		for (const rom_entry *romp = rom_first_region(*device); romp != NULL && !ROMENTRY_ISEND(romp); romp++)
		{
			// if this is a region, make sure it's valid, and record the length
			if (ROMENTRY_ISREGION(romp))
			{
				// if we haven't seen any items since the last region, print a warning
				if (items_since_region == 0)
					osd_printf_warning("Empty ROM region '%s' (warning)\n", last_region_name);

				// reset our region tracking states
				const char *basetag = ROMREGION_GETTAG(romp);
				items_since_region = (ROMREGION_ISERASE(romp) || ROMREGION_ISDISKDATA(romp)) ? 1 : 0;
				last_region_name = basetag;

				// check for a valid tag
				if (basetag == NULL)
				{
					osd_printf_error("ROM_REGION tag with NULL name\n");
					continue;
				}

				// validate the base tag
				validate_tag(basetag);

				// generate the full tag
				astring fulltag;
				rom_region_name(fulltag, *device, romp);

				// attempt to add it to the map, reporting duplicates as errors
				current_length = ROMREGION_GETLENGTH(romp);
				if (m_region_map.add(fulltag, current_length, false) == TMERR_DUPLICATE)
					osd_printf_error("Multiple ROM_REGIONs with the same tag '%s' defined\n", fulltag.cstr());
			}

			// If this is a system bios, make sure it is using the next available bios number
			else if (ROMENTRY_ISSYSTEM_BIOS(romp))
			{
				int bios_flags = ROM_GETBIOSFLAGS(romp);
				if (bios_flags != last_bios + 1)
					osd_printf_error("Non-sequential bios %s (specified as %d, expected to be %d)\n", ROM_GETNAME(romp), bios_flags, last_bios + 1);
				last_bios = bios_flags;
			}

			// if this is a file, make sure it is properly formatted
			else if (ROMENTRY_ISFILE(romp))
			{
				// track the last filename we found
				last_name = ROM_GETNAME(romp);
				total_files++;

				// make sure the hash is valid
				hash_collection hashes;
				if (!hashes.from_internal_string(ROM_GETHASHDATA(romp)))
					osd_printf_error("ROM '%s' has an invalid hash string '%s'\n", last_name, ROM_GETHASHDATA(romp));
			}

			// for any non-region ending entries, make sure they don't extend past the end
			if (!ROMENTRY_ISREGIONEND(romp) && current_length > 0)
			{
				items_since_region++;
				if (ROM_GETOFFSET(romp) + ROM_GETLENGTH(romp) > current_length)
					osd_printf_error("ROM '%s' extends past the defined memory region\n", last_name);
			}
		}

		// final check for empty regions
		if (items_since_region == 0)
			osd_printf_warning("Empty ROM region '%s' (warning)\n", last_region_name);


		// reset the current device
		m_current_device = NULL;
	}
}


//-------------------------------------------------
//  validate_analog_input_field - validate an
//  analog input field
//-------------------------------------------------

void validity_checker::validate_analog_input_field(ioport_field &field)
{
	// analog ports must have a valid sensitivity
	if (field.sensitivity() == 0)
		osd_printf_error("Analog port with zero sensitivity\n");

	// check that the default falls in the bitmask range
	if (field.defvalue() & ~field.mask())
		osd_printf_error("Analog port with a default value (%X) out of the bitmask range (%X)\n", field.defvalue(), field.mask());

	// tests for positional devices
	if (field.type() == IPT_POSITIONAL || field.type() == IPT_POSITIONAL_V)
	{
		int shift;
		for (shift = 0; shift <= 31 && (~field.mask() & (1 << shift)) != 0; shift++) ;

		// convert the positional max value to be in the bitmask for testing
		INT32 analog_max = field.maxval();
		analog_max = (analog_max - 1) << shift;

		// positional port size must fit in bits used
		if ((field.mask() >> shift) + 1 < field.maxval())
			osd_printf_error("Analog port with a positional port size bigger then the mask size\n");
	}

	// tests for absolute devices
	else if (field.type() > IPT_ANALOG_ABSOLUTE_FIRST && field.type() < IPT_ANALOG_ABSOLUTE_LAST)
	{
		// adjust for signed values
		INT32 default_value = field.defvalue();
		INT32 analog_min = field.minval();
		INT32 analog_max = field.maxval();
		if (analog_min > analog_max)
		{
			analog_min = -analog_min;
			if (default_value > analog_max)
				default_value = -default_value;
		}

		// check that the default falls in the MINMAX range
		if (default_value < analog_min || default_value > analog_max)
			osd_printf_error("Analog port with a default value (%X) out of PORT_MINMAX range (%X-%X)\n", field.defvalue(), field.minval(), field.maxval());

		// check that the MINMAX falls in the bitmask range
		// we use the unadjusted min for testing
		if (field.minval() & ~field.mask() || analog_max & ~field.mask())
			osd_printf_error("Analog port with a PORT_MINMAX (%X-%X) value out of the bitmask range (%X)\n", field.minval(), field.maxval(), field.mask());

		// absolute analog ports do not use PORT_RESET
		if (field.analog_reset())
			osd_printf_error("Absolute analog port using PORT_RESET\n");

		// absolute analog ports do not use PORT_WRAPS
		if (field.analog_wraps())
			osd_printf_error("Absolute analog port using PORT_WRAPS\n");
	}

	// tests for non IPT_POSITIONAL relative devices
	else
	{
		// relative devices do not use PORT_MINMAX
		if (field.minval() != 0 || field.maxval() != field.mask())
			osd_printf_error("Relative port using PORT_MINMAX\n");

		// relative devices do not use a default value
		// the counter is at 0 on power up
		if (field.defvalue() != 0)
			osd_printf_error("Relative port using non-0 default value\n");

		// relative analog ports do not use PORT_WRAPS
		if (field.analog_wraps())
			osd_printf_error("Absolute analog port using PORT_WRAPS\n");
	}
}


//-------------------------------------------------
//  validate_dip_settings - validate a DIP switch
//  setting
//-------------------------------------------------

void validity_checker::validate_dip_settings(ioport_field &field)
{
	const char *demo_sounds = ioport_string_from_index(INPUT_STRING_Demo_Sounds);
	const char *flipscreen = ioport_string_from_index(INPUT_STRING_Flip_Screen);
	UINT8 coin_list[__input_string_coinage_end + 1 - __input_string_coinage_start] = { 0 };
	bool coin_error = false;

	// iterate through the settings
	for (ioport_setting *setting = field.first_setting(); setting != NULL; setting = setting->next())
	{
		// note any coinage strings
		int strindex = get_defstr_index(setting->name());
		if (strindex >= __input_string_coinage_start && strindex <= __input_string_coinage_end)
			coin_list[strindex - __input_string_coinage_start] = 1;

		// make sure demo sounds default to on
		if (field.name() == demo_sounds && strindex == INPUT_STRING_On && field.defvalue() != setting->value())
			osd_printf_error("Demo Sounds must default to On\n");

		// check for bad demo sounds options
		if (field.name() == demo_sounds && (strindex == INPUT_STRING_Yes || strindex == INPUT_STRING_No))
			osd_printf_error("Demo Sounds option must be Off/On, not %s\n", setting->name());

		// check for bad flip screen options
		if (field.name() == flipscreen && (strindex == INPUT_STRING_Yes || strindex == INPUT_STRING_No))
			osd_printf_error("Flip Screen option must be Off/On, not %s\n", setting->name());

		// if we have a neighbor, compare ourselves to him
		if (setting->next() != NULL)
		{
			// check for inverted off/on dispswitch order
			int next_strindex = get_defstr_index(setting->next()->name(), true);
			if (strindex == INPUT_STRING_On && next_strindex == INPUT_STRING_Off)
				osd_printf_error("%s option must have Off/On options in the order: Off, On\n", field.name());

			// check for inverted yes/no dispswitch order
			else if (strindex == INPUT_STRING_Yes && next_strindex == INPUT_STRING_No)
				osd_printf_error("%s option must have Yes/No options in the order: No, Yes\n", field.name());

			// check for inverted upright/cocktail dispswitch order
			else if (strindex == INPUT_STRING_Cocktail && next_strindex == INPUT_STRING_Upright)
				osd_printf_error("%s option must have Upright/Cocktail options in the order: Upright, Cocktail\n", field.name());

			// check for proper coin ordering
			else if (strindex >= __input_string_coinage_start && strindex <= __input_string_coinage_end && next_strindex >= __input_string_coinage_start && next_strindex <= __input_string_coinage_end &&
						strindex >= next_strindex && setting->condition() == setting->next()->condition())
			{
				osd_printf_error("%s option has unsorted coinage %s > %s\n", field.name(), setting->name(), setting->next()->name());
				coin_error = true;
			}
		}
	}

	// if we have a coin error, demonstrate the correct way
	if (coin_error)
	{
		output_via_delegate(m_saved_error_output, "   Note proper coin sort order should be:\n");
		for (int entry = 0; entry < ARRAY_LENGTH(coin_list); entry++)
			if (coin_list[entry])
				output_via_delegate(m_saved_error_output, "      %s\n", ioport_string_from_index(__input_string_coinage_start + entry));
	}
}


//-------------------------------------------------
//  validate_condition - validate a condition
//  stored within an ioport field or setting
//-------------------------------------------------

void validity_checker::validate_condition(ioport_condition &condition, device_t &device, int_map &port_map)
{
	// resolve the tag
	astring porttag;
	device.subtag(porttag, condition.tag());

	// then find a matching port
	if (port_map.find(porttag) == 0)
		osd_printf_error("Condition referencing non-existent ioport tag '%s'\n", condition.tag());
}


//-------------------------------------------------
//  validate_inputs - validate input configuration
//-------------------------------------------------

void validity_checker::validate_inputs()
{
	int_map port_map;

	// iterate over devices
	device_iterator iter(m_current_config->root_device());
	for (device_t *device = iter.first(); device != NULL; device = iter.next())
	{
		// see if this device has ports; if not continue
		if (device->input_ports() == NULL)
			continue;

		// for non-root devices, track the current device
		m_current_device = (device == &m_current_config->root_device()) ? NULL : device;

		// allocate the input ports
		ioport_list portlist;
		astring errorbuf;
		portlist.append(*device, errorbuf);

		// report any errors during construction
		if (errorbuf)
			osd_printf_error("I/O port error during construction:\n%s\n", errorbuf.cstr());

		// do a first pass over ports to add their names and find duplicates
		for (ioport_port *port = portlist.first(); port != NULL; port = port->next())
			if (port_map.add(port->tag(), 1, false) == TMERR_DUPLICATE)
				osd_printf_error("Multiple I/O ports with the same tag '%s' defined\n", port->tag());

		// iterate over ports
		for (ioport_port *port = portlist.first(); port != NULL; port = port->next())
		{
			m_current_ioport = port->tag();

			// iterate through the fields on this port
			for (ioport_field *field = port->first_field(); field != NULL; field = field->next())
			{
				// verify analog inputs
				if (field->is_analog())
					validate_analog_input_field(*field);

				// look for invalid (0) types which should be mapped to IPT_OTHER
				if (field->type() == IPT_INVALID)
					osd_printf_error("Field has an invalid type (0); use IPT_OTHER instead\n");

				// verify dip switches
				if (field->type() == IPT_DIPSWITCH)
				{
					// dip switch fields must have a name
					if (field->name() == NULL)
						osd_printf_error("DIP switch has a NULL name\n");

					// verify the settings list
					validate_dip_settings(*field);
				}

				// verify names
				const char *name = field->specific_name();
				if (name != NULL)
				{
					// check for empty string
					if (name[0] == 0)
						osd_printf_error("Field name is an empty string\n");

					// check for trailing spaces
					if (name[0] != 0 && name[strlen(name) - 1] == ' ')
						osd_printf_error("Field '%s' has trailing spaces\n", name);

					// check for invalid UTF-8
					if (!utf8_is_valid_string(name))
						osd_printf_error("Field '%s' has invalid characters\n", name);

					// look up the string and print an error if default strings are not used
					/*strindex =get_defstr_index(defstr_map, name, driver, &error);*/
				}

				// verify conditions on the field
				if (!field->condition().none())
					validate_condition(field->condition(), *device, port_map);

				// verify conditions on the settings
				for (ioport_setting *setting = field->first_setting(); setting != NULL; setting = setting->next())
					if (!setting->condition().none())
						validate_condition(setting->condition(), *device, port_map);
			}

			// done with this port
			m_current_ioport = NULL;
		}

		// done with this device
		m_current_device = NULL;
	}
}


//-------------------------------------------------
//  validate_devices - run per-device validity
//  checks
//-------------------------------------------------

void validity_checker::validate_devices()
{
	int_map device_map;

	device_iterator iter_find(m_current_config->root_device());
	for (const device_t *device = iter_find.first(); device != NULL; device = iter_find.next())
	{
		device->findit(true);
	}

	// iterate over devices
	device_iterator iter(m_current_config->root_device());
	for (const device_t *device = iter.first(); device != NULL; device = iter.next())
	{
		// for non-root devices, track the current device
		m_current_device = (device == &m_current_config->root_device()) ? NULL : device;

		// validate the device tag
		validate_tag(device->basetag());

		// look for duplicates
		if (device_map.add(device->tag(), 0, false) == TMERR_DUPLICATE)
			osd_printf_error("Multiple devices with the same tag '%s' defined\n", device->tag());

		// all devices must have a shortname
		if (strcmp(device->shortname(), "") == 0)
			osd_printf_error("Device does not have short name defined\n");

		// all devices must have a source file defined
		if (strcmp(device->source(), "") == 0)
			osd_printf_error("Device does not have source file location defined\n");

		// check for device-specific validity check
		device->validity_check(*this);

		// done with this device
		m_current_device = NULL;
	}

	// if device is slot cart device, we must have a shortname
	int_map slot_device_map;
	slot_interface_iterator slotiter(m_current_config->root_device());
	for (const device_slot_interface *slot = slotiter.first(); slot != NULL; slot = slotiter.next())
	{
		for (const device_slot_option *option = slot->first_option(); option != NULL; option = option->next())
		{
			astring temptag("_");
			temptag.cat(option->name());
			device_t *dev = const_cast<machine_config &>(*m_current_config).device_add(&m_current_config->root_device(), temptag.cstr(), option->devtype(), 0);

			// notify this device and all its subdevices that they are now configured
			device_iterator subiter(*dev);
			for (device_t *device = subiter.first(); device != NULL; device = subiter.next())
				if (!device->configured())
					device->config_complete();

			if (strcmp(dev->shortname(), "") == 0) {
				if (slot_device_map.add(dev->name(), 0, false) != TMERR_DUPLICATE)
					osd_printf_error("Device '%s' is slot cart device but does not have short name defined\n",dev->name());
			}

			const_cast<machine_config &>(*m_current_config).device_remove(&m_current_config->root_device(), temptag.cstr());
		}
	}

}


//-------------------------------------------------
//  build_output_prefix - create a prefix
//  indicating the current source file, driver,
//  and device
//-------------------------------------------------

void validity_checker::build_output_prefix(astring &string)
{
	// start empty
	string.reset();

	// if we have a current device, indicate that
	if (m_current_device != NULL)
		string.cat(m_current_device->name()).cat(" device '").cat(m_current_device->tag()).cat("': ");

	// if we have a current port, indicate that as well
	if (m_current_ioport != NULL)
		string.cat("ioport '").cat(m_current_ioport).cat("': ");
}


//-------------------------------------------------
//  error_output - error message output override
//-------------------------------------------------

void validity_checker::error_output(const char *format, va_list argptr)
{
	// count the error
	m_errors++;

	// output the source(driver) device 'tag'
	astring output;
	build_output_prefix(output);

	// generate the string
	output.catvprintf(format, argptr);
	m_error_text.cat(output);
}


//-------------------------------------------------
//  warning_output - warning message output
//  override
//-------------------------------------------------

void validity_checker::warning_output(const char *format, va_list argptr)
{
	// count the error
	m_warnings++;

	// output the source(driver) device 'tag'
	astring output;
	build_output_prefix(output);

	// generate the string and output to the original target
	output.catvprintf(format, argptr);
	m_warning_text.cat(output);
}


//-------------------------------------------------
//  output_via_delegate - helper to output a
//  message via a varargs string, so the argptr
//  can be forwarded onto the given delegate
//-------------------------------------------------

void validity_checker::output_via_delegate(output_delegate &delegate, const char *format, ...)
{
	va_list argptr;

	// call through to the delegate with the proper parameters
	va_start(argptr, format);
	delegate(format, argptr);
	va_end(argptr);
}
