629391 - GC delete operator should be resilient to NULL

Status: RESOLVED FIXED

(Tamarin Graveyard :: Garbage Collection (mmGC), defect, P2)

Description

[Tommy Reilly]

It currently calls FreeNotNull which seems wrong, unless the C++ compiler generates the NULL check?

Comment 1

[Lars T Hansen]

IMO operator delete should not be resilient to NULL, because GC::Free is not allowed on a NULL pointer by long-standing tradition.

Comment 2

[Lars T Hansen]

(In reply to comment #1)
> IMO operator delete should not be resilient to NULL, because GC::Free is not
> allowed on a NULL pointer by long-standing tradition.

Actually that's a ludicrous claim.

Anyway:

I thought the delete operator would only be invoked on non-NULL pointers and I thought I checked that when I wrote the code.  But I've not yet found prose in the C++ spec to back me up on that.

Comment 3

[Tommy Reilly]

The compiler does not do a NULL check and the default delete operator handles NULL.

Comment 4

[Steven Johnson]

C++ operator delete explicitly allows NULL pointers, so any "delete" we offer should probably do so as well, to re-use brainprint.

Comment 5

[Tommy Reilly]

Attachment: allow null arg to delete

Ruchi needs this to complete her audit changes.

Comment 6

[Tamarin Bot]

changeset: 5859:485ac738ec90
user:      Tommy Reilly <[e-mail]>
summary:   [Bug 629391] GC delete operator should be resilient to NULL (r=lhansen)

http://hg.mozilla.org/tamarin-redux/rev/485ac738ec90