view Python/getargs.c @ 28572:faeb708bacc4 2.2

Backport: PyErr_NormalizeException(): in the type==NULL test, we should simply return. Setting an exception can mess with the exception state, and continuing is definitely wrong (since type is dereferenced later on). Some code that calls this seems to be prepared for a NULL exception type, so let's be safe rather than sorry and simply assume there's nothing to normalize in this case.
author Guido van Rossum <guido@python.org>
date Thu, 10 Apr 2003 20:30:18 +0000
parents 608735dd2ebc
children
line wrap: on
line source


/* New getargs implementation */

#include "Python.h"

#include <ctype.h>


int PyArg_Parse(PyObject *, char *, ...);
int PyArg_ParseTuple(PyObject *, char *, ...);
int PyArg_VaParse(PyObject *, char *, va_list);

int PyArg_ParseTupleAndKeywords(PyObject *, PyObject *,
				char *, char **, ...);

/* Forward */
static int vgetargs1(PyObject *, char *, va_list *, int);
static void seterror(int, char *, int *, char *, char *);
static char *convertitem(PyObject *, char **, va_list *, int *, char *, 
			 size_t);
static char *converttuple(PyObject *, char **, va_list *,
			  int *, char *, size_t, int);
static char *convertsimple(PyObject *, char **, va_list *, char *, size_t);
static int convertbuffer(PyObject *, void **p, char **);

static int vgetargskeywords(PyObject *, PyObject *,
			    char *, char **, va_list *);
static char *skipitem(char **, va_list *);

int
PyArg_Parse(PyObject *args, char *format, ...)
{
	int retval;
	va_list va;
	
	va_start(va, format);
	retval = vgetargs1(args, format, &va, 1);
	va_end(va);
	return retval;
}


int
PyArg_ParseTuple(PyObject *args, char *format, ...)
{
	int retval;
	va_list va;
	
	va_start(va, format);
	retval = vgetargs1(args, format, &va, 0);
	va_end(va);
	return retval;
}


int
PyArg_VaParse(PyObject *args, char *format, va_list va)
{
	va_list lva;

#ifdef VA_LIST_IS_ARRAY
	memcpy(lva, va, sizeof(va_list));
#else
#ifdef __va_copy
	__va_copy(lva, va);
#else
	lva = va;
#endif
#endif

	return vgetargs1(args, format, &lva, 0);
}


static int
vgetargs1(PyObject *args, char *format, va_list *p_va, int compat)
{
	char msgbuf[256];
	int levels[32];
	char *fname = NULL;
	char *message = NULL;
	int min = -1;
	int max = 0;
	int level = 0;
	int endfmt = 0;
	char *formatsave = format;
	int i, len;
	char *msg;
	
	assert(compat || (args != (PyObject*)NULL));

	while (endfmt == 0) {
		int c = *format++;
		switch (c) {
		case '(':
			if (level == 0)
				max++;
			level++;
			break;
		case ')':
			if (level == 0)
				Py_FatalError("excess ')' in getargs format");
			else
				level--;
			break;
		case '\0':
			endfmt = 1;
			break;
		case ':':
			fname = format;
			endfmt = 1;
			break;
		case ';':
			message = format;
			endfmt = 1;
			break;
		default:
			if (level == 0) {
				if (c == 'O')
					max++;
				else if (isalpha(c)) {
					if (c != 'e') /* skip encoded */
						max++;
				} else if (c == '|')
					min = max;
			}
			break;
		}
	}
	
	if (level != 0)
		Py_FatalError(/* '(' */ "missing ')' in getargs format");
	
	if (min < 0)
		min = max;
	
	format = formatsave;
	
	if (compat) {
		if (max == 0) {
			if (args == NULL)
				return 1;
			PyOS_snprintf(msgbuf, sizeof(msgbuf),
				      "%.200s%s takes no arguments",
				      fname==NULL ? "function" : fname,
				      fname==NULL ? "" : "()");
			PyErr_SetString(PyExc_TypeError, msgbuf);
			return 0;
		}
		else if (min == 1 && max == 1) {
			if (args == NULL) {
				PyOS_snprintf(msgbuf, sizeof(msgbuf),
				      "%.200s%s takes at least one argument",
					      fname==NULL ? "function" : fname,
					      fname==NULL ? "" : "()");
				PyErr_SetString(PyExc_TypeError, msgbuf);
				return 0;
			}
			msg = convertitem(args, &format, p_va, levels, msgbuf,
					  sizeof(msgbuf));
			if (msg == NULL)
				return 1;
			seterror(levels[0], msg, levels+1, fname, message);
			return 0;
		}
		else {
			PyErr_SetString(PyExc_SystemError,
			    "old style getargs format uses new features");
			return 0;
		}
	}
	
	if (!PyTuple_Check(args)) {
		PyErr_SetString(PyExc_SystemError,
		    "new style getargs format but argument is not a tuple");
		return 0;
	}
	
	len = PyTuple_GET_SIZE(args);
	
	if (len < min || max < len) {
		if (message == NULL) {
			PyOS_snprintf(msgbuf, sizeof(msgbuf),
				      "%.150s%s takes %s %d argument%s "
				      "(%d given)",
				      fname==NULL ? "function" : fname,
				      fname==NULL ? "" : "()",
				      min==max ? "exactly"
				      : len < min ? "at least" : "at most",
				      len < min ? min : max,
				      (len < min ? min : max) == 1 ? "" : "s",
				      len);
			message = msgbuf;
		}
		PyErr_SetString(PyExc_TypeError, message);
		return 0;
	}
	
	for (i = 0; i < len; i++) {
		if (*format == '|')
			format++;
		msg = convertitem(PyTuple_GET_ITEM(args, i), &format, p_va,
				  levels, msgbuf, sizeof(msgbuf));
		if (msg) {
			seterror(i+1, msg, levels, fname, message);
			return 0;
		}
	}

	if (*format != '\0' && !isalpha((int)(*format)) &&
	    *format != '(' &&
	    *format != '|' && *format != ':' && *format != ';') {
		PyErr_Format(PyExc_SystemError,
			     "bad format string: %.200s", formatsave);
		return 0;
	}
	
	return 1;
}



static void
seterror(int iarg, char *msg, int *levels, char *fname, char *message)
{
	char buf[512];
	int i;
	char *p = buf;

	if (PyErr_Occurred())
		return;
	else if (message == NULL) {
		if (fname != NULL) {
			PyOS_snprintf(p, sizeof(buf), "%.200s() ", fname);
			p += strlen(p);
		}
		if (iarg != 0) {
			PyOS_snprintf(p, sizeof(buf) - (p - buf),
				      "argument %d", iarg);
			i = 0;
			p += strlen(p);
			while (levels[i] > 0 && (int)(p-buf) < 220) {
				PyOS_snprintf(p, sizeof(buf) - (buf - p),
					      ", item %d", levels[i]-1);
				p += strlen(p);
				i++;
			}
		}
		else {
			PyOS_snprintf(p, sizeof(buf) - (p - buf), "argument");
			p += strlen(p);
		}
		PyOS_snprintf(p, sizeof(buf) - (p - buf), " %.256s", msg);
		message = buf;
	}
	PyErr_SetString(PyExc_TypeError, message);
}


/* Convert a tuple argument.
   On entry, *p_format points to the character _after_ the opening '('.
   On successful exit, *p_format points to the closing ')'.
   If successful:
      *p_format and *p_va are updated,
      *levels and *msgbuf are untouched,
      and NULL is returned.
   If the argument is invalid:
      *p_format is unchanged,
      *p_va is undefined,
      *levels is a 0-terminated list of item numbers,
      *msgbuf contains an error message, whose format is:
         "must be <typename1>, not <typename2>", where:
            <typename1> is the name of the expected type, and
            <typename2> is the name of the actual type,
      and msgbuf is returned.
*/

static char *
converttuple(PyObject *arg, char **p_format, va_list *p_va, int *levels,
	     char *msgbuf, size_t bufsize, int toplevel)
{
	int level = 0;
	int n = 0;
	char *format = *p_format;
	int i;
	
	for (;;) {
		int c = *format++;
		if (c == '(') {
			if (level == 0)
				n++;
			level++;
		}
		else if (c == ')') {
			if (level == 0)
				break;
			level--;
		}
		else if (c == ':' || c == ';' || c == '\0')
			break;
		else if (level == 0 && isalpha(c))
			n++;
	}
	
	if (!PySequence_Check(arg) || PyString_Check(arg)) {
		levels[0] = 0;
		PyOS_snprintf(msgbuf, bufsize,
			      toplevel ? "expected %d arguments, not %.50s" :
			              "must be %d-item sequence, not %.50s",
			      n, 
			      arg == Py_None ? "None" : arg->ob_type->tp_name);
		return msgbuf;
	}
	
	if ((i = PySequence_Size(arg)) != n) {
		levels[0] = 0;
		PyOS_snprintf(msgbuf, bufsize,
			      toplevel ? "expected %d arguments, not %d" :
			             "must be sequence of length %d, not %d",
			      n, i);
		return msgbuf;
	}

	format = *p_format;
	for (i = 0; i < n; i++) {
		char *msg;
		PyObject *item;
		item = PySequence_GetItem(arg, i);
		msg = convertitem(item, &format, p_va, levels+1, msgbuf,
				  bufsize);
		/* PySequence_GetItem calls tp->sq_item, which INCREFs */
		Py_XDECREF(item);
		if (msg != NULL) {
			levels[0] = i+1;
			return msg;
		}
	}

	*p_format = format;
	return NULL;
}


/* Convert a single item. */

static char *
convertitem(PyObject *arg, char **p_format, va_list *p_va, int *levels,
	    char *msgbuf, size_t bufsize)
{
	char *msg;
	char *format = *p_format;
	
	if (*format == '(' /* ')' */) {
		format++;
		msg = converttuple(arg, &format, p_va, levels, msgbuf, 
				   bufsize, 0);
		if (msg == NULL)
			format++;
	}
	else {
		msg = convertsimple(arg, &format, p_va, msgbuf, bufsize);
		if (msg != NULL)
			levels[0] = 0;
	}
	if (msg == NULL)
		*p_format = format;
	return msg;
}



#define UNICODE_DEFAULT_ENCODING(arg) \
        _PyUnicode_AsDefaultEncodedString(arg, NULL)

/* Format an error message generated by convertsimple(). */

static char *
converterr(char *expected, PyObject *arg, char *msgbuf, size_t bufsize)
{
	assert(expected != NULL);
	assert(arg != NULL); 
	PyOS_snprintf(msgbuf, bufsize,
		      "must be %.50s, not %.50s", expected,
		      arg == Py_None ? "None" : arg->ob_type->tp_name);
	return msgbuf;
}

#define CONV_UNICODE "(unicode conversion error)"

/* Convert a non-tuple argument.  Return NULL if conversion went OK,
   or a string with a message describing the failure.  The message is
   formatted as "must be <desired type>, not <actual type>".
   When failing, an exception may or may not have been raised.
   Don't call if a tuple is expected. 
*/

static char *
convertsimple(PyObject *arg, char **p_format, va_list *p_va, char *msgbuf,
	      size_t bufsize)
{
	char *format = *p_format;
	char c = *format++;
	PyObject *uarg;
	
	switch (c) {
	
	case 'b': { /* unsigned byte -- very short int */
		char *p = va_arg(*p_va, char *);
		long ival = PyInt_AsLong(arg);
		if (ival == -1 && PyErr_Occurred())
			return converterr("integer<b>", arg, msgbuf, bufsize);
		else if (ival < 0) {
			PyErr_SetString(PyExc_OverflowError,
			"unsigned byte integer is less than minimum");
			return converterr("integer<b>", arg, msgbuf, bufsize);
		}
		else if (ival > UCHAR_MAX) {
			PyErr_SetString(PyExc_OverflowError,
			"unsigned byte integer is greater than maximum");
			return converterr("integer<b>", arg, msgbuf, bufsize);
		}
		else
			*p = (unsigned char) ival;
		break;
	}
	
	case 'B': {/* byte sized bitfield - both signed and unsigned
		      values allowed */  
		char *p = va_arg(*p_va, char *);
		long ival = PyInt_AsLong(arg);
		if (ival == -1 && PyErr_Occurred())
			return converterr("integer<b>", arg, msgbuf, bufsize);
		else if (ival < SCHAR_MIN) {
			PyErr_SetString(PyExc_OverflowError,
			"byte-sized integer bitfield is less than minimum");
			return converterr("integer<B>", arg, msgbuf, bufsize);
		}
		else if (ival > (int)UCHAR_MAX) {
			PyErr_SetString(PyExc_OverflowError,
			"byte-sized integer bitfield is greater than maximum");
			return converterr("integer<B>", arg, msgbuf, bufsize);
		}
		else
			*p = (unsigned char) ival;
		break;
	}
	
	case 'h': {/* signed short int */
		short *p = va_arg(*p_va, short *);
		long ival = PyInt_AsLong(arg);
		if (ival == -1 && PyErr_Occurred())
			return converterr("integer<h>", arg, msgbuf, bufsize);
		else if (ival < SHRT_MIN) {
			PyErr_SetString(PyExc_OverflowError,
			"signed short integer is less than minimum");
			return converterr("integer<h>", arg, msgbuf, bufsize);
		}
		else if (ival > SHRT_MAX) {
			PyErr_SetString(PyExc_OverflowError,
			"signed short integer is greater than maximum");
			return converterr("integer<h>", arg, msgbuf, bufsize);
		}
		else
			*p = (short) ival;
		break;
	}
	
	case 'H': { /* short int sized bitfield, both signed and
		       unsigned allowed */ 
		unsigned short *p = va_arg(*p_va, unsigned short *);
		long ival = PyInt_AsLong(arg);
		if (ival == -1 && PyErr_Occurred())
			return converterr("integer<H>", arg, msgbuf, bufsize);
		else if (ival < SHRT_MIN) {
			PyErr_SetString(PyExc_OverflowError,
			"short integer bitfield is less than minimum");
			return converterr("integer<H>", arg, msgbuf, bufsize);
		}
		else if (ival > USHRT_MAX) {
			PyErr_SetString(PyExc_OverflowError,
			"short integer bitfield is greater than maximum");
			return converterr("integer<H>", arg, msgbuf, bufsize);
		}
		else
			*p = (unsigned short) ival;
		break;
	}
	
	case 'i': {/* signed int */
		int *p = va_arg(*p_va, int *);
		long ival = PyInt_AsLong(arg);
		if (ival == -1 && PyErr_Occurred())
			return converterr("integer<i>", arg, msgbuf, bufsize);
		else if (ival > INT_MAX) {
			PyErr_SetString(PyExc_OverflowError,
				"signed integer is greater than maximum");
			return converterr("integer<i>", arg, msgbuf, bufsize);
		}
		else if (ival < INT_MIN) {
			PyErr_SetString(PyExc_OverflowError,
				"signed integer is less than minimum");
			return converterr("integer<i>", arg, msgbuf, bufsize);
		}
		else
			*p = ival;
		break;
	}

	case 'l': {/* long int */
		long *p = va_arg(*p_va, long *);
		long ival = PyInt_AsLong(arg);
		if (ival == -1 && PyErr_Occurred())
			return converterr("integer<l>", arg, msgbuf, bufsize);
		else
			*p = ival;
		break;
	}
	
#ifdef HAVE_LONG_LONG
	case 'L': {/* LONG_LONG */
		LONG_LONG *p = va_arg( *p_va, LONG_LONG * );
		LONG_LONG ival = PyLong_AsLongLong( arg );
		if( ival == (LONG_LONG)-1 && PyErr_Occurred() ) {
			return converterr("long<L>", arg, msgbuf, bufsize);
		} else {
			*p = ival;
		}
		break;
	}
#endif
	
	case 'f': {/* float */
		float *p = va_arg(*p_va, float *);
		double dval = PyFloat_AsDouble(arg);
		if (PyErr_Occurred())
			return converterr("float<f>", arg, msgbuf, bufsize);
		else
			*p = (float) dval;
		break;
	}
	
	case 'd': {/* double */
		double *p = va_arg(*p_va, double *);
		double dval = PyFloat_AsDouble(arg);
		if (PyErr_Occurred())
			return converterr("float<d>", arg, msgbuf, bufsize);
		else
			*p = dval;
		break;
	}
	
#ifndef WITHOUT_COMPLEX
	case 'D': {/* complex double */
		Py_complex *p = va_arg(*p_va, Py_complex *);
		Py_complex cval;
		cval = PyComplex_AsCComplex(arg);
		if (PyErr_Occurred())
			return converterr("complex<D>", arg, msgbuf, bufsize);
		else
			*p = cval;
		break;
	}
#endif /* WITHOUT_COMPLEX */
	
	case 'c': {/* char */
		char *p = va_arg(*p_va, char *);
		if (PyString_Check(arg) && PyString_Size(arg) == 1)
			*p = PyString_AS_STRING(arg)[0];
		else
			return converterr("char", arg, msgbuf, bufsize);
		break;
	}
	
	case 's': {/* string */
		if (*format == '#') {
			void **p = (void **)va_arg(*p_va, char **);
			int *q = va_arg(*p_va, int *);
			
			if (PyString_Check(arg)) {
				*p = PyString_AS_STRING(arg);
				*q = PyString_GET_SIZE(arg);
			}
#ifdef Py_USING_UNICODE
			else if (PyUnicode_Check(arg)) {
				uarg = UNICODE_DEFAULT_ENCODING(arg);
				if (uarg == NULL)
					return converterr(CONV_UNICODE,
							  arg, msgbuf, bufsize);
				*p = PyString_AS_STRING(uarg);
				*q = PyString_GET_SIZE(uarg);
			}
#endif
			else { /* any buffer-like object */
				char *buf;
				int count = convertbuffer(arg, p, &buf);
				if (count < 0)
					return converterr(buf, arg, msgbuf, bufsize);
				*q = count;
			}
			format++;
		} else {
			char **p = va_arg(*p_va, char **);
			
			if (PyString_Check(arg))
				*p = PyString_AS_STRING(arg);
#ifdef Py_USING_UNICODE
			else if (PyUnicode_Check(arg)) {
				uarg = UNICODE_DEFAULT_ENCODING(arg);
				if (uarg == NULL)
					return converterr(CONV_UNICODE,
							  arg, msgbuf, bufsize);
				*p = PyString_AS_STRING(uarg);
			}
#endif
			else
				return converterr("string", arg, msgbuf, bufsize);
			if ((int)strlen(*p) != PyString_Size(arg))
				return converterr("string without null bytes",
						  arg, msgbuf, bufsize);
		}
		break;
	}

	case 'z': {/* string, may be NULL (None) */
		if (*format == '#') { /* any buffer-like object */
			void **p = (void **)va_arg(*p_va, char **);
			int *q = va_arg(*p_va, int *);
			
			if (arg == Py_None) {
				*p = 0;
				*q = 0;
			}
			else if (PyString_Check(arg)) {
				*p = PyString_AS_STRING(arg);
				*q = PyString_GET_SIZE(arg);
			}
#ifdef Py_USING_UNICODE
			else if (PyUnicode_Check(arg)) {
				uarg = UNICODE_DEFAULT_ENCODING(arg);
				if (uarg == NULL)
					return converterr(CONV_UNICODE,
							  arg, msgbuf, bufsize);
				*p = PyString_AS_STRING(uarg);
				*q = PyString_GET_SIZE(uarg);
			}
#endif
			else { /* any buffer-like object */
				char *buf;
				int count = convertbuffer(arg, p, &buf);
				if (count < 0)
					return converterr(buf, arg, msgbuf, bufsize);
				*q = count;
			}
			format++;
		} else {
			char **p = va_arg(*p_va, char **);
			
			if (arg == Py_None)
				*p = 0;
			else if (PyString_Check(arg))
				*p = PyString_AS_STRING(arg);
#ifdef Py_USING_UNICODE
			else if (PyUnicode_Check(arg)) {
				uarg = UNICODE_DEFAULT_ENCODING(arg);
				if (uarg == NULL)
					return converterr(CONV_UNICODE,
							  arg, msgbuf, bufsize);
				*p = PyString_AS_STRING(uarg);
			}
#endif
			else
				return converterr("string or None", 
						  arg, msgbuf, bufsize);
			if (*format == '#') {
				int *q = va_arg(*p_va, int *);
				if (arg == Py_None)
					*q = 0;
				else
					*q = PyString_Size(arg);
				format++;
			}
			else if (*p != NULL &&
				 (int)strlen(*p) != PyString_Size(arg))
				return converterr(
					"string without null bytes or None", 
					arg, msgbuf, bufsize);
		}
		break;
	}
	
	case 'e': {/* encoded string */
		char **buffer;
		const char *encoding;
		PyObject *s;
		int size, recode_strings;

		/* Get 'e' parameter: the encoding name */
		encoding = (const char *)va_arg(*p_va, const char *);
#ifdef Py_USING_UNICODE
		if (encoding == NULL)
			encoding = PyUnicode_GetDefaultEncoding();
#endif
			
		/* Get output buffer parameter:
		   's' (recode all objects via Unicode) or
		   't' (only recode non-string objects) 
		*/
		if (*format == 's')
			recode_strings = 1;
		else if (*format == 't')
			recode_strings = 0;
		else
			return converterr(
				"(unknown parser marker combination)",
				arg, msgbuf, bufsize);
		buffer = (char **)va_arg(*p_va, char **);
		format++;
		if (buffer == NULL)
			return converterr("(buffer is NULL)", 
					  arg, msgbuf, bufsize);
			
		/* Encode object */
		if (!recode_strings && PyString_Check(arg)) {
			s = arg;
			Py_INCREF(s);
		}
		else {
#ifdef Py_USING_UNICODE
		    	PyObject *u;

			/* Convert object to Unicode */
			u = PyUnicode_FromObject(arg);
			if (u == NULL)
				return converterr(
					"string or unicode or text buffer", 
					arg, msgbuf, bufsize);
			
			/* Encode object; use default error handling */
			s = PyUnicode_AsEncodedString(u,
						      encoding,
						      NULL);
			Py_DECREF(u);
			if (s == NULL)
				return converterr("(encoding failed)",
						  arg, msgbuf, bufsize);
			if (!PyString_Check(s)) {
				Py_DECREF(s);
				return converterr(
					"(encoder failed to return a string)",
					arg, msgbuf, bufsize);
			}
#else
			return converterr("string<e>", arg, msgbuf, bufsize);
#endif
		}
		size = PyString_GET_SIZE(s);

		/* Write output; output is guaranteed to be 0-terminated */
		if (*format == '#') { 
			/* Using buffer length parameter '#':
				   
			   - if *buffer is NULL, a new buffer of the
			   needed size is allocated and the data
			   copied into it; *buffer is updated to point
			   to the new buffer; the caller is
			   responsible for PyMem_Free()ing it after
			   usage 

			   - if *buffer is not NULL, the data is
			   copied to *buffer; *buffer_len has to be
			   set to the size of the buffer on input;
			   buffer overflow is signalled with an error;
			   buffer has to provide enough room for the
			   encoded string plus the trailing 0-byte
			   
			   - in both cases, *buffer_len is updated to
			   the size of the buffer /excluding/ the
			   trailing 0-byte 
			   
			*/
			int *buffer_len = va_arg(*p_va, int *);

			format++;
			if (buffer_len == NULL)
				return converterr(
					"(buffer_len is NULL)",
					arg, msgbuf, bufsize);
			if (*buffer == NULL) {
				*buffer = PyMem_NEW(char, size + 1);
				if (*buffer == NULL) {
					Py_DECREF(s);
					return converterr(
						"(memory error)",
						arg, msgbuf, bufsize);
				}
			} else {
				if (size + 1 > *buffer_len) {
					Py_DECREF(s);
					return converterr(
						"(buffer overflow)", 
						arg, msgbuf, bufsize);
				}
			}
			memcpy(*buffer,
			       PyString_AS_STRING(s),
			       size + 1);
			*buffer_len = size;
		} else {
			/* Using a 0-terminated buffer:
				   
			   - the encoded string has to be 0-terminated
			   for this variant to work; if it is not, an
			   error raised 

			   - a new buffer of the needed size is
			   allocated and the data copied into it;
			   *buffer is updated to point to the new
			   buffer; the caller is responsible for
			   PyMem_Free()ing it after usage

			*/
			if ((int)strlen(PyString_AS_STRING(s)) != size)
				return converterr(
					"(encoded string without NULL bytes)",
					arg, msgbuf, bufsize);
			*buffer = PyMem_NEW(char, size + 1);
			if (*buffer == NULL) {
				Py_DECREF(s);
				return converterr("(memory error)",
						  arg, msgbuf, bufsize);
			}
			memcpy(*buffer,
			       PyString_AS_STRING(s),
			       size + 1);
		}
		Py_DECREF(s);
		break;
	}

#ifdef Py_USING_UNICODE
	case 'u': {/* raw unicode buffer (Py_UNICODE *) */
		if (*format == '#') { /* any buffer-like object */
			void **p = (void **)va_arg(*p_va, char **);
			int *q = va_arg(*p_va, int *);
			char *buf;
			int count = convertbuffer(arg, p, &buf);

			if (count < 0)
				return converterr(buf, arg, msgbuf, bufsize);
			*q = count/(sizeof(Py_UNICODE)); 
			format++;
		} else {
			Py_UNICODE **p = va_arg(*p_va, Py_UNICODE **);
			
			if (PyUnicode_Check(arg))
				*p = PyUnicode_AS_UNICODE(arg);
			else
				return converterr("unicode", arg, msgbuf, bufsize);
		}
		break;
	}
#endif

	case 'S': { /* string object */
		PyObject **p = va_arg(*p_va, PyObject **);
		if (PyString_Check(arg))
			*p = arg;
		else
			return converterr("string", arg, msgbuf, bufsize);
		break;
	}
	
#ifdef Py_USING_UNICODE
	case 'U': { /* Unicode object */
		PyObject **p = va_arg(*p_va, PyObject **);
		if (PyUnicode_Check(arg))
			*p = arg;
		else
			return converterr("unicode", arg, msgbuf, bufsize);
		break;
	}
#endif
	
	case 'O': { /* object */
		PyTypeObject *type;
		PyObject **p;
		if (*format == '!') {
			type = va_arg(*p_va, PyTypeObject*);
			p = va_arg(*p_va, PyObject **);
			format++;
			if (PyType_IsSubtype(arg->ob_type, type))
				*p = arg;
			else
				return converterr(type->tp_name, arg, msgbuf, bufsize);

		}
		else if (*format == '?') {
			inquiry pred = va_arg(*p_va, inquiry);
			p = va_arg(*p_va, PyObject **);
			format++;
			if ((*pred)(arg)) 
				*p = arg;
			else
				return converterr("(unspecified)", 
						  arg, msgbuf, bufsize);
				
		}
		else if (*format == '&') {
			typedef int (*converter)(PyObject *, void *);
			converter convert = va_arg(*p_va, converter);
			void *addr = va_arg(*p_va, void *);
			format++;
			if (! (*convert)(arg, addr))
				return converterr("(unspecified)", 
						  arg, msgbuf, bufsize);
		}
		else {
			p = va_arg(*p_va, PyObject **);
			*p = arg;
		}
		break;
	}
		
		
	case 'w': { /* memory buffer, read-write access */
		void **p = va_arg(*p_va, void **);
		PyBufferProcs *pb = arg->ob_type->tp_as_buffer;
		int count;
			
		if (pb == NULL || 
		    pb->bf_getwritebuffer == NULL ||
		    pb->bf_getsegcount == NULL)
			return converterr("read-write buffer", arg, msgbuf, bufsize);
		if ((*pb->bf_getsegcount)(arg, NULL) != 1)
			return converterr("single-segment read-write buffer", 
					  arg, msgbuf, bufsize);
		if ((count = pb->bf_getwritebuffer(arg, 0, p)) < 0)
			return converterr("(unspecified)", arg, msgbuf, bufsize);
		if (*format == '#') {
			int *q = va_arg(*p_va, int *);
			
			*q = count;
			format++;
		}
		break;
	}
		
	case 't': { /* 8-bit character buffer, read-only access */
		const char **p = va_arg(*p_va, const char **);
		PyBufferProcs *pb = arg->ob_type->tp_as_buffer;
		int count;
		
		if (*format++ != '#')
			return converterr(
				"invalid use of 't' format character", 
				arg, msgbuf, bufsize);
		if (!PyType_HasFeature(arg->ob_type,
				       Py_TPFLAGS_HAVE_GETCHARBUFFER) ||
		    pb == NULL || pb->bf_getcharbuffer == NULL ||
		    pb->bf_getsegcount == NULL)
			return converterr(
				"string or read-only character buffer",
				arg, msgbuf, bufsize);

		if (pb->bf_getsegcount(arg, NULL) != 1)
			return converterr(
				"string or single-segment read-only buffer",
				arg, msgbuf, bufsize);

		count = pb->bf_getcharbuffer(arg, 0, p);
		if (count < 0)
			return converterr("(unspecified)", arg, msgbuf, bufsize);
		*va_arg(*p_va, int *) = count;
		break;
	}

	default:
		return converterr("impossible<bad format char>", arg, msgbuf, bufsize);
	
	}
	
	*p_format = format;
	return NULL;
}

static int
convertbuffer(PyObject *arg, void **p, char **errmsg)
{
	PyBufferProcs *pb = arg->ob_type->tp_as_buffer;
	int count;
	if (pb == NULL ||
	    pb->bf_getreadbuffer == NULL ||
	    pb->bf_getsegcount == NULL) {
		*errmsg = "string or read-only buffer";
		return -1;
	}
	if ((*pb->bf_getsegcount)(arg, NULL) != 1) {
		*errmsg = "string or single-segment read-only buffer";
		return -1;
	}
	if ((count = (*pb->bf_getreadbuffer)(arg, 0, p)) < 0) {
		*errmsg = "(unspecified)";
	}
	return count;
}

/* Support for keyword arguments donated by
   Geoff Philbrick <philbric@delphi.hks.com> */

/* Return false (0) for error, else true. */
int
PyArg_ParseTupleAndKeywords(PyObject *args,
			    PyObject *keywords,
			    char *format, 
			    char **kwlist, ...)
{
	int retval;
	va_list va;

	if ((args == NULL || !PyTuple_Check(args)) ||
	    (keywords != NULL && !PyDict_Check(keywords)) ||
	    format == NULL ||
	    kwlist == NULL)
	{
		PyErr_BadInternalCall();
		return 0;
	}

	va_start(va, kwlist);
	retval = vgetargskeywords(args, keywords, format, kwlist, &va);	
	va_end(va);
	return retval;
}


static int
vgetargskeywords(PyObject *args, PyObject *keywords, char *format,
	         char **kwlist, va_list *p_va)
{
	char msgbuf[512];
	int levels[32];
	char *fname, *message;
	int min, max;
	char *formatsave;
	int i, len, nargs, nkeywords;
	char *msg, **p;

	assert(args != NULL && PyTuple_Check(args));
	assert(keywords == NULL || PyDict_Check(keywords));
	assert(format != NULL);
	assert(kwlist != NULL);
	assert(p_va != NULL);

	/* Search the format:
	   message <- error msg, if any (else NULL).
	   fname <- routine name, if any (else NULL).
	   min <- # of required arguments, or -1 if all are required.
	   max <- most arguments (required + optional).
	   Check that kwlist has a non-NULL entry for each arg.
	   Raise error if a tuple arg spec is found.
	*/
	fname = message = NULL;
	formatsave = format;
	p = kwlist;
	min = -1;
	max = 0;
	while ((i = *format++) != '\0') {
		if (isalpha(i) && i != 'e') {
			max++;
			if (*p == NULL) {
				PyErr_SetString(PyExc_RuntimeError,
					"more argument specifiers than "
					"keyword list entries");
				return 0;
			}
			p++;
		}
		else if (i == '|')
			min = max;
		else if (i == ':') {
			fname = format;
			break;
		}
		else if (i == ';') {
			message = format;
			break;
		}
		else if (i == '(') {
			PyErr_SetString(PyExc_RuntimeError,
				"tuple found in format when using keyword "
				"arguments");
			return 0;
		}
	}
	format = formatsave;
	if (*p != NULL) {
		PyErr_SetString(PyExc_RuntimeError,
			"more keyword list entries than "
			"argument specifiers");
		return 0;
	}
	if (min < 0) {
		/* All arguments are required. */
		min = max;
	}

	nargs = PyTuple_GET_SIZE(args);
	nkeywords = keywords == NULL ? 0 : PyDict_Size(keywords);

	/* make sure there are no duplicate values for an argument;
	   its not clear when to use the term "keyword argument vs. 
	   keyword parameter in messages */
	if (nkeywords > 0) {
		for (i = 0; i < nargs; i++) {
			char *thiskw = kwlist[i];
			if (thiskw == NULL)
				break;
			if (PyDict_GetItemString(keywords, thiskw)) {
				PyErr_Format(PyExc_TypeError,
					"keyword parameter '%s' was given "
					"by position and by name",
					thiskw);
				return 0;
			}
			else if (PyErr_Occurred())
				return 0;
		}
	}

	/* required arguments missing from args can be supplied by keyword 
	   arguments; set len to the number of posiitional arguments, and,
	   if that's less than the minimum required, add in the number of
	   required arguments that are supplied by keywords */
	len = nargs;
	if (nkeywords > 0 && nargs < min) {
		for (i = nargs; i < min; i++) {
			if (PyDict_GetItemString(keywords, kwlist[i]))
				len++;
			else if (PyErr_Occurred())
				return 0;
		}
	}

	/* make sure we got an acceptable number of arguments; the message
	   is a little confusing with keywords since keyword arguments
	   which are supplied, but don't match the required arguments
	   are not included in the "%d given" part of the message */
	if (len < min || max < len) {
		if (message == NULL) {
			PyOS_snprintf(msgbuf, sizeof(msgbuf),
				      "%.200s%s takes %s %d argument%s "
				      "(%d given)",
				      fname==NULL ? "function" : fname,
				      fname==NULL ? "" : "()",
				      min==max ? "exactly"
			              : len < min ? "at least" : "at most",
				      len < min ? min : max,
				      (len < min ? min : max) == 1 ? "" : "s",
				      len);
			message = msgbuf;
		}
		PyErr_SetString(PyExc_TypeError, message);
		return 0;
	}

	/* convert the positional arguments */
	for (i = 0; i < nargs; i++) {
		if (*format == '|')
			format++;
		msg = convertitem(PyTuple_GET_ITEM(args, i), &format, p_va,
				 levels, msgbuf, sizeof(msgbuf));
		if (msg) {
			seterror(i+1, msg, levels, fname, message);
			return 0;
		}
	}

	/* handle no keyword parameters in call */	
	if (nkeywords == 0)
		return 1; 

	/* convert the keyword arguments; this uses the format 
	   string where it was left after processing args */
	for (i = nargs; i < max; i++) {
		PyObject *item;
		if (*format == '|')
			format++;
		item = PyDict_GetItemString(keywords, kwlist[i]);
		if (item != NULL) {
			Py_INCREF(item);
			msg = convertitem(item, &format, p_va, levels, msgbuf,
					  sizeof(msgbuf));
			Py_DECREF(item);
			if (msg) {
				seterror(i+1, msg, levels, fname, message);
				return 0;
			}
			--nkeywords;
			if (nkeywords == 0)
				break;
		}
		else if (PyErr_Occurred())
			return 0;
		else {
			msg = skipitem(&format, p_va);
			if (msg) {
				seterror(i+1, msg, levels, fname, message);
				return 0;
			}
		}
	}

	/* make sure there are no extraneous keyword arguments */
	if (nkeywords > 0) {
		PyObject *key, *value;
		int pos = 0;
		while (PyDict_Next(keywords, &pos, &key, &value)) {
			int match = 0;
			char *ks = PyString_AsString(key);
			for (i = 0; i < max; i++) {
				if (!strcmp(ks, kwlist[i])) {
					match = 1;
					break;
				}
			}
			if (!match) {
				PyErr_Format(PyExc_TypeError,
					     "'%s' is an invalid keyword "
					     "argument for this function",
					     ks);
				return 0;
			}
		}
	}

	return 1;
}


static char *
skipitem(char **p_format, va_list *p_va)
{
	char *format = *p_format;
	char c = *format++;
	
	switch (c) {
	
	case 'b': /* byte -- very short int */
	case 'B': /* byte as bitfield */
		{
			(void) va_arg(*p_va, char *);
			break;
		}
	
	case 'h': /* short int */
		{
			(void) va_arg(*p_va, short *);
			break;
		}
	
	case 'H': /* short int as bitfield */
		{
			(void) va_arg(*p_va, unsigned short *);
			break;
		}
	
	case 'i': /* int */
		{
			(void) va_arg(*p_va, int *);
			break;
		}
	
	case 'l': /* long int */
		{
			(void) va_arg(*p_va, long *);
			break;
		}
	
#ifdef HAVE_LONG_LONG
	case 'L': /* LONG_LONG int */
		{
			(void) va_arg(*p_va, LONG_LONG *);
			break;
		}
#endif
	
	case 'f': /* float */
		{
			(void) va_arg(*p_va, float *);
			break;
		}
	
	case 'd': /* double */
		{
			(void) va_arg(*p_va, double *);
			break;
		}
	
#ifndef WITHOUT_COMPLEX
	case 'D': /* complex double */
		{
			(void) va_arg(*p_va, Py_complex *);
			break;
		}
#endif /* WITHOUT_COMPLEX */
	
	case 'c': /* char */
		{
			(void) va_arg(*p_va, char *);
			break;
		}
	
	case 's': /* string */
		{
			(void) va_arg(*p_va, char **);
			if (*format == '#') {
				(void) va_arg(*p_va, int *);
				format++;
			}
			break;
		}
	
	case 'z': /* string */
		{
			(void) va_arg(*p_va, char **);
			if (*format == '#') {
				(void) va_arg(*p_va, int *);
				format++;
			}
			break;
		}
	
	case 'S': /* string object */
		{
			(void) va_arg(*p_va, PyObject **);
			break;
		}
	
	case 'O': /* object */
		{
			if (*format == '!') {
				format++;
				(void) va_arg(*p_va, PyTypeObject*);
				(void) va_arg(*p_va, PyObject **);
			}
#if 0
/* I don't know what this is for */
			else if (*format == '?') {
				inquiry pred = va_arg(*p_va, inquiry);
				format++;
				if ((*pred)(arg)) {
					(void) va_arg(*p_va, PyObject **);
				}
			}
#endif
			else if (*format == '&') {
				typedef int (*converter)(PyObject *, void *);
				(void) va_arg(*p_va, converter);
				(void) va_arg(*p_va, void *);
				format++;
			}
			else {
				(void) va_arg(*p_va, PyObject **);
			}
			break;
		}
	
	default:
		return "impossible<bad format char>";
	
	}
	
	*p_format = format;
	return NULL;
}


int
PyArg_UnpackTuple(PyObject *args, char *name, int min, int max, ...)
{
	int i, l;
	PyObject **o;
	va_list vargs;

#ifdef HAVE_STDARG_PROTOTYPES
	va_start(vargs, max);
#else
	va_start(vargs);
#endif

	assert(min >= 0);
	assert(min <= max);
	if (!PyTuple_Check(args)) {
		PyErr_SetString(PyExc_SystemError,
		    "PyArg_UnpackTuple() argument list is not a tuple");
		return 0;
	}	
	l = PyTuple_GET_SIZE(args);
	if (l < min) {
		if (name != NULL)
			PyErr_Format(
			    PyExc_TypeError,
			    "%s expected %s%d arguments, got %d", 
			    name, (min == max ? "" : "at least "), min, l);
		else
			PyErr_Format(
			    PyExc_TypeError,
			    "unpacked tuple should have %s%d elements,"
			    " but has %d", 
			    (min == max ? "" : "at least "), min, l);
		va_end(vargs);
		return 0;
	}
	if (l > max) {
		if (name != NULL)
			PyErr_Format(
			    PyExc_TypeError,
			    "%s expected %s%d arguments, got %d", 
			    name, (min == max ? "" : "at most "), max, l);
		else
			PyErr_Format(
			    PyExc_TypeError,
			    "unpacked tuple should have %s%d elements,"
			    " but has %d", 
			    (min == max ? "" : "at most "), max, l);
		va_end(vargs);
		return 0;
	}
	for (i = 0; i < l; i++) {
		o = va_arg(vargs, PyObject **);
		*o = PyTuple_GET_ITEM(args, i);
	}
	va_end(vargs);
	return 1;
}