1636889 - `nsCOMPtr` instance is not known to be live when called in method annotated with `MOZ_CAN_RUN_SCRIPT`

Status: NEW

(Developer Infrastructure :: Source Code Analysis, defect, P2)

Description

[Mirko Brodesser (:mbrodesser-Igalia)]

Happens in https://phabricator.services.mozilla.com/D74383.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:andi, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 2

[Andi [:andi]]

maybe I'm missing something but can you specify what were you expecting here to happen?

Comment 3

[Nathan Froyd [:froydnj]]

(In reply to Andi-Bogdan Postelnicu [:andi] from comment #2)

maybe I'm missing something but can you specify what were you expecting here to happen?

I think the point is that offsets lives on the stack and is therefore holding its members (including the nsCOMPtr) alive. This case shouldn't be considered any different from a bare nsCOMPtr that lives on the stack.

Comment 4

[Mirko Brodesser (:mbrodesser-Igalia)]

(In reply to Nathan Froyd [:froydnj] from comment #3)

(In reply to Andi-Bogdan Postelnicu [:andi] from comment #2)

maybe I'm missing something but can you specify what were you expecting here to happen?

I think the point is that offsets lives on the stack and is therefore holding its members (including the nsCOMPtr) alive. This case shouldn't be considered any different from a bare nsCOMPtr that lives on the stack.

Yes, that's what I meant. Thanks for the explanation.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:andi, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 6

[Mirko Brodesser (:mbrodesser-Igalia)]

When fixing this bug, we should also remove the corresponding MOZ_KnownLives (e.g. https://searchfox.org/mozilla-central/rev/07342ce09126c513540c1c343476e026cfa907bf/layout/generic/nsFrameSelection.cpp#1311).