getargs.c

python s60 1.4.5版本的源代码

/* Portions Copyright (c) 2005-2006 Nokia Corporation */

/* 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);

// XXX:CW32
int PyArg_ParseTupleAndKeywords(PyObject *, PyObject *,
				char *, const char * const *, ...);

/* 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 *);

DL_EXPORT(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;
}


DL_EXPORT(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;
}


DL_EXPORT(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,