678998 - Make js_IsFunctionQName infallible, so that determining the nature of a property lookup is clearer

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jeff Walden [:Waldo]]

Property storage splitting will be clearer if a property lookup can be determined to be non-elemental (that is, obj[2]) and non-property (that is, obj["prop"]) without potential for failure.  It's fairly easy to do this -- just make sure that QName objects store an atom, not merely a string, in their localName slots.

Comment 1

[Jeff Walden [:Waldo]]

Attachment: 1 - Make the localName slot store an atom

Comment 2

[Jeff Walden [:Waldo]]

Attachment: 2 - Rename js_IsFunctionQName and make it infallible

Comment 3

[Luke Wagner [:luke]]

Comment on attachment 553184 [details] [diff] [review]
1 - Make the localName slot store an atom

Review of attachment 553184 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jsxml.cpp
@@ +2815,2 @@
>  static JSBool
>  IsFunctionQName(JSContext *cx, JSObject *qn, jsid *funidp)

You can unfallible-ize this function now, if you so choose.

Comment 4

[Luke Wagner [:luke]]

Comment on attachment 553184 [details] [diff] [review]
1 - Make the localName slot store an atom

Review of attachment 553184 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jsxml.cpp
@@ +2815,2 @@
>  static JSBool
>  IsFunctionQName(JSContext *cx, JSObject *qn, jsid *funidp)

Err, so you have :)

Comment 5

[Jeff Walden [:Waldo]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/c6a3b64dcac0
http://hg.mozilla.org/integration/mozilla-inbound/rev/c36563ee6447

I should probably get in the habit of beginning patch sequences like this with an overview/prognosticating comment.  I did the same thing to Blake in the typed-array-initialization bug -- he made a comment on an earlier patch, I had it resolved in a later one.  :-)

Comment 6

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

http://hg.mozilla.org/mozilla-central/rev/c6a3b64dcac0
http://hg.mozilla.org/mozilla-central/rev/c36563ee6447