574299 - TM: implement a runtime-wide wrap hook

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

Add a wrap hook that the engine invokes every time an object crosses a compartment boundary. This can be used to wrap objects into specialized JSCrossCompartmentWrappers that implement an access policy in addition to the mere cross compartment functionality.

virtual bool filter(JSContext *cx, JSObject *proxy, jsval id = JSVAL_VOID);
virtual bool enter(JSContext *cx, JSObject *proxy, void **statep);
virtual void leave(JSContext *cx, JSObject *proxy, void *state);

filter() can be used to filter out properties. enter() and leave() are called around wrapper operations (PIERCE).

For-each iterator objects are censored since there is no good way to filter them. A specific wrapper can overwrite this behavior by providing its own implementations for this derived API:

virtual bool filterProps(JSContext *cx, JSObject *proxy, js::AutoValueVector &props);
virtual bool filterIterator(JSContext *cx, JSObject *proxy, jsval *vp);

A highly transparent wrapper might want to overwrite filterIterator() and always permit it (just return "true", don't filter).

Comment 1

[Andreas Gal :gal]

Attachment: patch

Comment 2

[Andreas Gal :gal]

Attachment: patch

Comment 3

[Jason Orendorff [:jorendorff]]

Comment on attachment 453807 [details] [diff] [review]
patch

Good first cut.

Comment 4

[Andreas Gal :gal]

http://hg.mozilla.org/tracemonkey/rev/dabc78724c89

Comment 5

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/dabc78724c89