Access checks now work, at least for instance data (not for methods
yet). The class is now passed to eval_code and stored in the current
frame. It is also stored in instance method objects. An "unbound"
instance method is now returned when a function is retrieved through
"classname.funcname", which when called passes the class to eval_code.
diff --git a/Objects/accessobject.c b/Objects/accessobject.c
new file mode 100644
index 0000000..41790cd
--- /dev/null
+++ b/Objects/accessobject.c
@@ -0,0 +1,320 @@
+/***********************************************************
+Copyright 1991, 1992, 1993 by Stichting Mathematisch Centrum,
+Amsterdam, The Netherlands.
+
+ All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Stichting Mathematisch
+Centrum or CWI not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior permission.
+
+STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
+THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
+FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+******************************************************************/
+
+/* Access object implementation */
+
+#include "allobjects.h"
+
+#include "structmember.h"
+#include "modsupport.h" /* For getargs() etc. */
+
+typedef struct {
+ OB_HEAD
+ object *ac_value;
+ object *ac_class;
+ typeobject *ac_type;
+ int ac_mode;
+} accessobject;
+
+/* Forward */
+static int typecheck PROTO((object *, typeobject *));
+static int classcheck PROTO((object *, object *, int, int));
+
+object *
+newaccessobject(value, class, type, mode)
+ object *value;
+ object *class;
+ typeobject *type;
+ int mode;
+{
+ accessobject *ap;
+ if (class != NULL && !is_classobject(class)) {
+ err_badcall();
+ return NULL;
+ }
+ if (!typecheck(value, type)) {
+ err_setstr(AccessError,
+ "access: initial value has inappropriate type");
+ return NULL;
+ }
+ ap = NEWOBJ(accessobject, &Accesstype);
+ if (ap == NULL)
+ return NULL;
+ XINCREF(value);
+ ap->ac_value = value;
+ XINCREF(class);
+ ap->ac_class = class;
+ XINCREF(type);
+ ap->ac_type = (typeobject *)type;
+ ap->ac_mode = mode;
+ return (object *)ap;
+}
+
+object *
+cloneaccessobject(op)
+ object *op;
+{
+ register accessobject *ap;
+ if (!is_accessobject(op)) {
+ err_badcall();
+ return NULL;
+ }
+ ap = (accessobject *)op;
+ return newaccessobject(ap->ac_value, ap->ac_class,
+ ap->ac_type, ap->ac_mode);
+}
+
+void
+setaccessowner(op, class)
+ object *op;
+ object *class;
+{
+ register accessobject *ap;
+ if (!is_accessobject(op) || class != NULL && !is_classobject(class))
+ return; /* XXX no error */
+ ap = (accessobject *)op;
+ XDECREF(ap->ac_class);
+ XINCREF(class);
+ ap->ac_class = class;
+}
+
+object *
+getaccessvalue(op, class)
+ object *op;
+ object *class;
+{
+ register accessobject *ap;
+ if (!is_accessobject(op)) {
+ err_badcall();
+ return NULL;
+ }
+ ap = (accessobject *)op;
+
+ if (!classcheck(class, ap->ac_class, AC_R, ap->ac_mode)) {
+ err_setstr(AccessError, "read access denied");
+ return NULL;
+ }
+
+ if (ap->ac_value == NULL) {
+ err_setstr(AccessError, "no current value");
+ return NULL;
+ }
+ INCREF(ap->ac_value);
+ return ap->ac_value;
+}
+
+int
+setaccessvalue(op, class, value)
+ object *op;
+ object *class;
+ object *value;
+{
+ register accessobject *ap;
+ if (!is_accessobject(op)) {
+ err_badcall();
+ return -1;
+ }
+ ap = (accessobject *)op;
+
+ if (!classcheck(class, ap->ac_class, AC_W, ap->ac_mode)) {
+ err_setstr(AccessError, "write access denied");
+ return -1;
+ }
+
+ if (!typecheck(value, ap->ac_type)) {
+ err_setstr(AccessError, "assign value of inappropriate type");
+ return -1;
+ }
+
+ if (value == NULL) { /* Delete it */
+ if (ap->ac_value == NULL) {
+ err_setstr(AccessError, "no current value");
+ return -1;
+ }
+ DECREF(ap->ac_value);
+ ap->ac_value = NULL;
+ return 0;
+ }
+ XDECREF(ap->ac_value);
+ INCREF(value);
+ ap->ac_value = value;
+ return 0;
+}
+
+static int
+typecheck(value, type)
+ object *value;
+ typeobject *type;
+{
+ object *x;
+ if (value == NULL || type == NULL)
+ return 1; /* No check */
+ if (value->ob_type == type)
+ return 1; /* Exact match */
+ if (type == &Anynumbertype) {
+ if (value->ob_type->tp_as_number == NULL)
+ return 0;
+ if (!is_instanceobject(value))
+ return 1;
+ /* For instances, make sure it really looks like a number */
+ x = getattr(value, "__sub__");
+ if (x == NULL) {
+ err_clear();
+ return 0;
+ }
+ DECREF(x);
+ return 1;
+ }
+ if (type == &Anysequencetype) {
+ if (value->ob_type->tp_as_sequence == NULL)
+ return 0;
+ if (!is_instanceobject(value))
+ return 1;
+ /* For instances, make sure it really looks like a sequence */
+ x = getattr(value, "__getslice__");
+ if (x == NULL) {
+ err_clear();
+ return 0;
+ }
+ DECREF(x);
+ return 1;
+ }
+ if (type == &Anymappingtype) {
+ if (value->ob_type->tp_as_mapping == NULL)
+ return 0;
+ if (!is_instanceobject(value))
+ return 1;
+ /* For instances, make sure it really looks like a mapping */
+ x = getattr(value, "__getitem__");
+ if (x == NULL) {
+ err_clear();
+ return 0;
+ }
+ DECREF(x);
+ return 1;
+ }
+ return 0;
+}
+
+static int
+classcheck(caller, owner, access, mode)
+ object *caller;
+ object *owner;
+ int access;
+ int mode;
+{
+ if (caller == owner && owner != NULL)
+ return access & mode & (AC_PRIVATE|AC_PROTECTED|AC_PUBLIC);
+ if (caller != NULL && owner != NULL && issubclass(caller, owner))
+ return access & mode & (AC_PROTECTED|AC_PUBLIC);
+ return access & mode & AC_PUBLIC;
+}
+
+/* Access methods */
+
+static void
+access_dealloc(ap)
+ accessobject *ap;
+{
+ XDECREF(ap->ac_value);
+ XDECREF(ap->ac_class);
+ XDECREF(ap->ac_type);
+ DEL(ap);
+}
+
+#define OFF(x) offsetof(accessobject, x)
+
+static struct memberlist access_memberlist[] = {
+ {"ac_value", T_OBJECT, OFF(ac_value)},
+ {"ac_class", T_OBJECT, OFF(ac_class)},
+ {"ac_type", T_OBJECT, OFF(ac_type)},
+ {"ac_mode", T_INT, OFF(ac_mode)},
+ {NULL} /* Sentinel */
+};
+
+static object *
+access_getattr(ap, name)
+ accessobject *ap;
+ char *name;
+{
+ return getmember((char *)ap, access_memberlist, name);
+}
+
+static object *
+access_repr(ap)
+ accessobject *ap;
+{
+ char buf[300];
+ classobject *class = (classobject *)ap->ac_class;
+ typeobject *type = ap->ac_type;
+ sprintf(buf, "<access object, class %.100s, type %.100s, mode 0%o>",
+ class ? getstringvalue(class->cl_name) : "-",
+ type ? type->tp_name : "-",
+ ap->ac_mode);
+ return newstringobject(buf);
+}
+
+typeobject Accesstype = {
+ OB_HEAD_INIT(&Typetype)
+ 0, /*ob_size*/
+ "access", /*tp_name*/
+ sizeof(accessobject), /*tp_size*/
+ 0, /*tp_itemsize*/
+ /* methods */
+ access_dealloc, /*tp_dealloc*/
+ 0, /*tp_print*/
+ access_getattr, /*tp_getattr*/
+ 0, /*tp_setattr*/
+ 0, /*tp_compare*/
+ access_repr, /*tp_repr*/
+ 0, /*tp_as_number*/
+ 0, /*tp_as_sequence*/
+ 0, /*tp_as_mapping*/
+ 0, /*tp_hash*/
+};
+
+/* Dummy type objects to indicate classes of types */
+
+/* XXX This should be replaced by a more general "subclassing"
+ XXX mechanism for type objects... */
+
+typeobject Anynumbertype = {
+ OB_HEAD_INIT(&Typetype)
+ 0, /*ob_size*/
+ "*number*", /*tp_name*/
+};
+
+/* XXX Should really distinguish mutable and immutable sequences as well */
+
+typeobject Anysequencetype = {
+ OB_HEAD_INIT(&Typetype)
+ 0, /*ob_size*/
+ "*sequence*", /*tp_name*/
+};
+
+typeobject Anymappingtype = {
+ OB_HEAD_INIT(&Typetype)
+ 0, /*ob_size*/
+ "*mapping*", /*tp_name*/
+};