abstract.c

python s60 1.4.5版本的源代码

/* Portions Copyright (c) 2005 Nokia Corporation */
/* Abstract Object Interface (many thanks to Jim Fulton) */


#include "Python.h"
#include <ctype.h>
#include "structmember.h" /* we need the offsetof() macro from there */
#include "longintrepr.h"

#define NEW_STYLE_NUMBER(o) PyType_HasFeature((o)->ob_type, \
				Py_TPFLAGS_CHECKTYPES)

/* Shorthands to return certain errors */

static PyObject *
type_error(const char *msg)
{
	PyErr_SetString(PyExc_TypeError, msg);
	return NULL;
}

static PyObject *
null_error(void)
{
	if (!PyErr_Occurred())
		PyErr_SetString(PyExc_SystemError,
				"null argument to internal routine");
	return NULL;
}

/* Operations on any object */

DL_EXPORT(int)
PyObject_Cmp(PyObject *o1, PyObject *o2, int *result)
{
	int r;

	if (o1 == NULL || o2 == NULL) {
		null_error();
		return -1;
	}
	r = PyObject_Compare(o1, o2);
	if (PyErr_Occurred())
		return -1;
	*result = r;
	return 0;
}

DL_EXPORT(PyObject *)
PyObject_Type(PyObject *o)
{
	PyObject *v;

	if (o == NULL)
		return null_error();
	v = (PyObject *)o->ob_type;
	Py_INCREF(v);
	return v;
}

DL_EXPORT(int)
PyObject_Size(PyObject *o)
{
	PySequenceMethods *m;

	if (o == NULL) {
		null_error();
		return -1;
	}

        // XXX:CW32
	m = (PySequenceMethods *)(o->ob_type->tp_as_sequence);
	if (m && m->sq_length)
		return m->sq_length(o);

	return PyMapping_Size(o);
}

#undef PyObject_Length
DL_EXPORT(int)
PyObject_Length(PyObject *o)
{
	return PyObject_Size(o);
}
#define PyObject_Length PyObject_Size

DL_EXPORT(PyObject *)
PyObject_GetItem(PyObject *o, PyObject *key)
{
	PyMappingMethods *m;

	if (o == NULL || key == NULL)
		return null_error();
	
  	// XXX:CW32 
	m = (PyMappingMethods *)o->ob_type->tp_as_mapping;
	if (m && m->mp_subscript)
		return m->mp_subscript(o, key);

	if (o->ob_type->tp_as_sequence) {
		if (PyInt_Check(key))
			return PySequence_GetItem(o, PyInt_AsLong(key));
		else if (PyLong_Check(key)) {
			long key_value = PyLong_AsLong(key);
			if (key_value == -1 && PyErr_Occurred())
				return NULL;
			return PySequence_GetItem(o, key_value);
		}
		else if (o->ob_type->tp_as_sequence->sq_item)
			return type_error("sequence index must be integer");
	}

	return type_error("unsubscriptable object");
}

DL_EXPORT(int)
PyObject_SetItem(PyObject *o, PyObject *key, PyObject *value)
{
	PyMappingMethods *m;

	if (o == NULL || key == NULL || value == NULL) {
		null_error();
		return -1;
	}
	// XXX:CW32
	m = (PyMappingMethods *)o->ob_type->tp_as_mapping;
	if (m && m->mp_ass_subscript)
		return m->mp_ass_subscript(o, key, value);

	if (o->ob_type->tp_as_sequence) {
		if (PyInt_Check(key))
			return PySequence_SetItem(o, PyInt_AsLong(key), value);
		else if (PyLong_Check(key)) {
			long key_value = PyLong_AsLong(key);
			if (key_value == -1 && PyErr_Occurred())
				return -1;
			return PySequence_SetItem(o, key_value, value);
		}
		else if (o->ob_type->tp_as_sequence->sq_ass_item) {
			type_error("sequence index must be integer");
			return -1;
		}
	}

	type_error("object does not support item assignment");
	return -1;
}

DL_EXPORT(int)
PyObject_DelItem(PyObject *o, PyObject *key)
{
	PyMappingMethods *m;

	if (o == NULL || key == NULL) {
		null_error();
		return -1;
	}
	// XXX:CW32
	m = (PyMappingMethods *)o->ob_type->tp_as_mapping;
	if (m && m->mp_ass_subscript)
		return m->mp_ass_subscript(o, key, (PyObject*)NULL);

	if (o->ob_type->tp_as_sequence) {
		if (PyInt_Check(key))
			return PySequence_DelItem(o, PyInt_AsLong(key));
		else if (PyLong_Check(key)) {
			long key_value = PyLong_AsLong(key);
			if (key_value == -1 && PyErr_Occurred())
				return -1;
			return PySequence_DelItem(o, key_value);
		}
		else if (o->ob_type->tp_as_sequence->sq_ass_item) {
			type_error("sequence index must be integer");
			return -1;
		}
	}

	type_error("object does not support item deletion");
	return -1;
}

DL_EXPORT(int)
PyObject_DelItemString(PyObject *o, char *key)
{
	PyObject *okey;
	int ret;

	if (o == NULL || key == NULL) {
		null_error();
		return -1;
	}
	okey = PyString_FromString(key);
	if (okey == NULL)
		return -1;
	ret = PyObject_DelItem(o, okey);
	Py_DECREF(okey);
	return ret;
}

DL_EXPORT(int)
PyObject_AsCharBuffer(PyObject *obj,
		      const char **buffer,
		      int *buffer_len)
{
	PyBufferProcs *pb;
	const char *pp;
	int len;

	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
		null_error();
		return -1;
	}
	// XXX:CW32
	pb = (PyBufferProcs *)obj->ob_type->tp_as_buffer;
	if (pb == NULL ||
	     pb->bf_getcharbuffer == NULL ||
	     pb->bf_getsegcount == NULL) {
		PyErr_SetString(PyExc_TypeError,
				"expected a character buffer object");
		return -1;
	}
	if ((*pb->bf_getsegcount)(obj,NULL) != 1) {
		PyErr_SetString(PyExc_TypeError,
				"expected a single-segment buffer object");
		return -1;
	}
	len = (*pb->bf_getcharbuffer)(obj, 0, &pp);
	if (len < 0)
		return -1;
	*buffer = pp;
	*buffer_len = len;
	return 0;
}

DL_EXPORT(int)
PyObject_CheckReadBuffer(PyObject *obj)
{
  	// XXX:CW32
	PyBufferProcs *pb = (PyBufferProcs *)obj->ob_type->tp_as_buffer;

	if (pb == NULL ||
	    pb->bf_getreadbuffer == NULL ||
	    pb->bf_getsegcount == NULL ||
	    (*pb->bf_getsegcount)(obj, NULL) != 1)
		return 0;
	return 1;
}

DL_EXPORT(int)
PyObject_AsReadBuffer(PyObject *obj,
		      const void **buffer,
		      int *buffer_len)
{
	PyBufferProcs *pb;
	void *pp;
	int len;

	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
		null_error();
		return -1;
	}
	
	// XXX:CW32 
	pb = (PyBufferProcs *)obj->ob_type->tp_as_buffer;
	if (pb == NULL ||
	     pb->bf_getreadbuffer == NULL ||
	     pb->bf_getsegcount == NULL) {
		PyErr_SetString(PyExc_TypeError,
				"expected a readable buffer object");
		return -1;
	}
	if ((*pb->bf_getsegcount)(obj, NULL) != 1) {
		PyErr_SetString(PyExc_TypeError,
				"expected a single-segment buffer object");
		return -1;
	}
	len = (*pb->bf_getreadbuffer)(obj, 0, &pp);
	if (len < 0)
		return -1;
	*buffer = pp;
	*buffer_len = len;
	return 0;
}

DL_EXPORT(int)
PyObject_AsWriteBuffer(PyObject *obj,
		       void **buffer,
		       int *buffer_len)
{
	PyBufferProcs *pb;
	void*pp;
	int len;

	if (obj == NULL || buffer == NULL || buffer_len == NULL) {
		null_error();
		return -1;
	}
	// XXX:CW32
	pb = (PyBufferProcs *)obj->ob_type->tp_as_buffer;
	if (pb == NULL ||
	     pb->bf_getwritebuffer == NULL ||
	     pb->bf_getsegcount == NULL) {
		PyErr_SetString(PyExc_TypeError,
				"expected a writeable buffer object");
		return -1;
	}
	if ((*pb->bf_getsegcount)(obj, NULL) != 1) {
		PyErr_SetString(PyExc_TypeError,
				"expected a single-segment buffer object");
		return -1;
	}
	len = (*pb->bf_getwritebuffer)(obj,0,&pp);
	if (len < 0)
		return -1;
	*buffer = pp;
	*buffer_len = len;
	return 0;
}

/* Operations on numbers */

DL_EXPORT(int)
PyNumber_Check(PyObject *o)
{
	return o && o->ob_type->tp_as_number;
}

/* Binary operators */

/* New style number protocol support */

#define NB_SLOT(x) offsetof(PyNumberMethods, x)
#define NB_BINOP(nb_methods, slot) \
		((binaryfunc*)(& ((char*)nb_methods)[slot] ))
#define NB_TERNOP(nb_methods, slot) \
		((ternaryfunc*)(& ((char*)nb_methods)[slot] ))

/*
  Calling scheme used for binary operations:

  v	w	Action
  -------------------------------------------------------------------
  new	new	w.op(v,w)[*], v.op(v,w), w.op(v,w)
  new	old	v.op(v,w), coerce(v,w), v.op(v,w)
  old	new	w.op(v,w), coerce(v,w), v.op(v,w)
  old	old	coerce(v,w), v.op(v,w)

  [*] only when v->ob_type != w->ob_type && w->ob_type is a subclass of
      v->ob_type

  Legend:
  -------
  * new == new style number
  * old == old style number
  * Action indicates the order in which operations are tried until either
    a valid result is produced or an error occurs.

 */

static PyObject *
binary_op1(PyObject *v, PyObject *w, const int op_slot)
{
	PyObject *x;
	binaryfunc slotv = NULL;
	binaryfunc slotw = NULL;

	if (v->ob_type->tp_as_number != NULL && NEW_STYLE_NUMBER(v))
		slotv = *NB_BINOP(v->ob_type->tp_as_number, op_slot);
	if (w->ob_type != v->ob_type &&
	    w->ob_type->tp_as_number != NULL && NEW_STYLE_NUMBER(w)) {
		slotw = *NB_BINOP(w->ob_type->tp_as_number, op_slot);
		if (slotw == slotv)
			slotw = NULL;
	}
	if (slotv) {
		if (slotw && PyType_IsSubtype(w->ob_type, v->ob_type)) {
			x = slotw(v, w);
			if (x != Py_NotImplemented)
				return x;
			Py_DECREF(x); /* can't do it */
			slotw = NULL;
		}
		x = slotv(v, w);
		if (x != Py_NotImplemented)
			return x;
		Py_DECREF(x); /* can't do it */
	}
	if (slotw) {
		x = slotw(v, w);
		if (x != Py_NotImplemented)
			return x;
		Py_DECREF(x); /* can't do it */
	}
	if (!NEW_STYLE_NUMBER(v) || !NEW_STYLE_NUMBER(w)) {
		int err = PyNumber_CoerceEx(&v, &w);
		if (err < 0) {
			return NULL;
		}
		if (err == 0) {
		  	// XXX:CW32
			PyNumberMethods *mv = (PyNumberMethods *)v->ob_type->tp_as_number;
			if (mv) {
				binaryfunc slot;
				slot = *NB_BINOP(mv, op_slot);
				if (slot) {
					PyObject *x = slot(v, w);
					Py_DECREF(v);
					Py_DECREF(w);
					return x;
				}
			}
			/* CoerceEx incremented the reference counts */
			Py_DECREF(v);
			Py_DECREF(w);
		}
	}
	Py_INCREF(Py_NotImplemented);
	return Py_NotImplemented;
}
	    
static PyObject *
binary_op(PyObject *v, PyObject *w, const int op_slot, const char *op_name)
{
	PyObject *result = binary_op1(v, w, op_slot);
	if (result == Py_NotImplemented) {
		Py_DECREF(Py_NotImplemented);
		PyErr_Format(
			PyExc_TypeError, 
			"unsupported operand type(s) for %s: '%s' and '%s'",
			op_name,
			v->ob_type->tp_name,
			w->ob_type->tp_name);
		return NULL;
	}
	return result;
}


/*
  Calling scheme used for ternary operations:

  *** In some cases, w.op is called before v.op; see binary_op1. ***

  v	w	z	Action
  -------------------------------------------------------------------
  new	new	new	v.op(v,w,z), w.op(v,w,z), z.op(v,w,z)
  new	old	new	v.op(v,w,z), z.op(v,w,z), coerce(v,w,z), v.op(v,w,z)
  old	new	new	w.op(v,w,z), z.op(v,w,z), coerce(v,w,z), v.op(v,w,z)
  old	old	new	z.op(v,w,z), coerce(v,w,z), v.op(v,w,z)
  new	new	old	v.op(v,w,z), w.op(v,w,z), coerce(v,w,z), v.op(v,w,z)
  new	old	old	v.op(v,w,z), coerce(v,w,z), v.op(v,w,z)
  old	new	old	w.op(v,w,z), coerce(v,w,z), v.op(v,w,z)
  old	old	old	coerce(v,w,z), v.op(v,w,z)

  Legend:
  -------
  * new == new style number
  * old == old style number
  * Action indicates the order in which operations are tried until either
    a valid result is produced or an error occurs.
  * coerce(v,w,z) actually does: coerce(v,w), coerce(v,z), coerce(w,z) and
    only if z != Py_None; if z == Py_None, then it is treated as absent
    variable and only coerce(v,w) is tried.

 */

static PyObject *
ternary_op(PyObject *v,
	   PyObject *w,
	   PyObject *z,
	   const int op_slot,
	   const char *op_name)
{
	PyNumberMethods *mv, *mw, *mz;
	PyObject *x = NULL;
	ternaryfunc slotv = NULL;
	ternaryfunc slotw = NULL;
	ternaryfunc slotz = NULL;
	
	// XXX:CW32
	mv = (PyNumberMethods *)v->ob_type->tp_as_number;
	// XXX:CW32
	mw = (PyNumberMethods *)w->ob_type->tp_as_number;
	if (mv != NULL && NEW_STYLE_NUMBER(v))
		slotv = *NB_TERNOP(mv, op_slot);
	if (w->ob_type != v->ob_type &&
	    mv != NULL && NEW_STYLE_NUMBER(w)) {
		slotw = *NB_TERNOP(mw, op_slot);
		if (slotw == slotv)
			slotw = NULL;
	}
	if (slotv) {
		if (slotw && PyType_IsSubtype(w->ob_type, v->ob_type)) {
			x = slotw(v, w, z);
			if (x != Py_NotImplemented)
				return x;
			Py_DECREF(x); /* can't do it */
			slotw = NULL;
		}
		x = slotv(v, w, z);
		if (x != Py_NotImplemented)
			return x;
		Py_DECREF(x); /* can't do it */
	}
	if (slotw) {
		x = slotw(v, w, z);
		if (x != Py_NotImplemented)
			return x;
		Py_DECREF(x); /* can't do it */
	}
	// XXX:CW32
	mz = (PyNumberMethods *)z->ob_type->tp_as_number;
	if (mz != NULL && NEW_STYLE_NUMBER(z)) {
		slotz = *NB_TERNOP(mz, op_slot);
		if (slotz == slotv || slotz == slotw)
			slotz = NULL;
		if (slotz) {
			x = slotz(v, w, z);
			if (x != Py_NotImplemented)
				return x;
			Py_DECREF(x); /* can't do it */
		}
	}

	if (!NEW_STYLE_NUMBER(v) || !NEW_STYLE_NUMBER(w) ||
			(z != Py_None && !NEW_STYLE_NUMBER(z))) {
		/* we have an old style operand, coerce */
		PyObject *v1, *z1, *w2, *z2;
		int c;
		
		c = PyNumber_Coerce(&v, &w);
		if (c != 0)
			goto error3;

		/* Special case: if the third argument is None, it is
		   treated as absent argument and not coerced. */
		if (z == Py_None) {
			if (v->ob_type->tp_as_number) {