Introduce access control in propertyIsEnumerable....

Introduce access control in propertyIsEnumerable.
Also, fix JSObject::getPropertyAttribute() so it deals correctly with access control modifiers.

Committed: http://code.google.com/p/v8/source/detail?r=665

[Mads Ager (chromium), 2008-10-28 20:02:38]

Overall, the change looks good.  I think we have to be careful that we do not
search the prototype during propertyIsEnumerable.  The ECMA-262 standard
explictly states that propertyIsEnumerable does not consider the prototype
chain.  Therefore, you would get:

var p = { x: 42 };
var o = { };
o.__proto__ = p;
propertyIsEnumerable(o.x);  // false
for (var name in o) print(name);  // prints x

I think all we have to do is propagate the continue_search parameter to the
GetAttributeWithFailedAccessCheck function and only search the prototype in case
it is true.

http://codereview.chromium.org/8834/diff/1/3
File src/objects.cc (right):

http://codereview.chromium.org/8834/diff/1/3#newcode270
Line 270: Object* receiver,
Parameters should be indented by four spaces instead of two.

http://codereview.chromium.org/8834/diff/1/3#newcode288
Line 288: case CONSTANT_FUNCTION: {
I think you might have to pass in a boolean indicating whether or not to search
the prototype chain.  The ECMA-262 standard says that propertyIsEnumerable does
not take the prototype chain into account (note to section 15.2.4.7), so we
probably should not search for accessors in the prototype chain in that case.

http://codereview.chromium.org/8834/diff/1/3#newcode301
Line 301: result->holder()->LookupRealNamedProperty(name, &r);
Similarly here, we probably need the boolean indicating whether or not to search
the prototype chain.  That is, whether this should be a LookupRealNamedProperty
or only a LocalLookupRealNamedProperty.

http://codereview.chromium.org/8834/diff/1/3#newcode1772
Line 1772: return GetPropertyAttributeWithFailedAccessCheck(receiver, result,
name);
I think we need to propagate the continue_search argument here.

http://codereview.chromium.org/8834/diff/1/5
File src/objects.h (right):

http://codereview.chromium.org/8834/diff/1/5#newcode1452
Line 1452: Object* receiver,
This should be a four space indent.  It looks like only three?

http://codereview.chromium.org/8834/diff/1/2
File test/cctest/test-api.cc (right):

http://codereview.chromium.org/8834/diff/1/2#newcode3427
Line 3427: "   if (p == 'blocked_prop') return false;"
We should also check that accessible_prop is actually enumerated.

Is there a reason for not just doing "for (var p in other)" instead of putting
other in the prototype chain?

Also, I think using a couple of more lines and some more whitespace would make
the code evaluated more readable.