511700 - Make "unrecognized selector" and "selector not recognized" ObjC errors fatal again

Status: NEW

(Core :: XPCOM, defect)

Description

[Jesse Ruderman]

These ObjC errors indicate likely memory safety bugs.  It might be better to crash, so we find out about these bugs, than to try to silently ignore them.

(Also: any ObjC exceptions that NSZombieEnabled triggers.)


Quoting Steven Michaud from bug 500470 (c6, c11):

Some of these (the non-fatal ones) are "fixed" by bug 486564. But others are real -- the "unrecognized selector" message usually indicates an attempt to access a deleted Objective-C object.

Actually, Josh's patch for bug 486574 made *all* Objective-C exceptions non-fatal.  You could argue that exceptions containing the strings "unrecognized selector" or "selector not recognized" should be made fatal again.

Comment 1

[Steven Michaud [:smichaud] (Retired)]

> These ObjC errors indicate likely memory safety bugs.  It might be
> better to crash, so we find out about these bugs, than to try to
> silently ignore them.

I think this is a good idea.

> (Also: any ObjC exceptions that NSZombieEnabled triggers.)

I'm not sure this is needed, though.  People who use NSZombieEnabled
should know what they're doing, and be able to find their own ways to
trap errors.