1392684 - Type Qualifiers discarded after return of ObtainGit

Status: RESOLVED FIXED

(Core :: IPC, defect)

Description

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

>  /home/worker/workspace/build/src/ipc/mscom/AgileReference.cpp:138:79: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]
>     static IGlobalInterfaceTable * const sGit = []() -> IGlobalInterfaceTable * const {

Comment 1

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

Attachment: Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

Review commit: https://reviewboard.mozilla.org/r/171230/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/171230/

Comment 2

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

Try Run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=78d7a38989b12d41c5e5a05c767d8f15a6bdc9c5

Comment 3

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

I don't understand what this warning is warning about — sGit is constant, yes, but forbidding any copy of the pointer value to be stored in a mutable variable seems unhelpful.  (The const qualifier is on the pointer type itself, not the pointer target.)

Comment 4

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

This seems harmless, but I'd rather it be looked at by someone who knows this specific code.

Comment 5

[(No longer employed by Mozilla) Aaron Klotz]

Comment on attachment 8899900 [details]
Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

https://reviewboard.mozilla.org/r/171230/#review176406

::: commit-message-de25e:1
(Diff revision 1)
> +Bug 1392684 Propogate const qualifier out to function return and all callers

Can you please provide a more specific commit message? Adding that you're modifying mscom::AgileReference would suffice.

Comment 6

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

Comment on attachment 8899900 [details]
Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/171230/diff/1-2/

Comment 7

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

Comment on attachment 8899900 [details]
Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/171230/diff/2-3/

Comment 8

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

(In reply to Jed Davis [:jld] (⏰UTC-6) from comment #3)
> I don't understand what this warning is warning about — sGit is constant,
> yes, but forbidding any copy of the pointer value to be stored in a mutable
> variable seems unhelpful.  (The const qualifier is on the pointer type
> itself, not the pointer target.)

Indeed, I misunderstood it. The error is saying "You're declaring this const, but nothing is going to obey that. The const is misleading and superfluous."

Re-flagging :aklotz for re-review since this is a meaningful change from the original patch.

New try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=d22e9169052e0996db6008f5a7fa3e1c6a648bc0

Comment 9

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

Comment on attachment 8899900 [details]
Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/171230/diff/3-4/

Comment 10

[(No longer employed by Mozilla) Aaron Klotz]

Comment on attachment 8899900 [details]
Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

https://reviewboard.mozilla.org/r/171230/#review176514

::: ipc/mscom/AgileReference.cpp:138
(Diff revision 4)
>  IGlobalInterfaceTable*
>  AgileReference::ObtainGit()
>  {
>    // Internally to COM, the Global Interface Table is a singleton, therefore we
>    // don't worry about holding onto this reference indefinitely.
> -  static IGlobalInterfaceTable * const sGit = []() -> IGlobalInterfaceTable * const {
> +  static IGlobalInterfaceTable * sGit = []() -> IGlobalInterfaceTable * {

Nit: Remove space between IGlobalInterfaceTable and '*'

Comment 11

[Tom Ritter [:tjr] (OOTO until 4/30 at least)]

Comment on attachment 8899900 [details]
Bug 1392684 Remove const qualifier that gets discarded after function return in mscom::AgileReference

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/171230/diff/4-5/

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/acae3198b087
Remove const qualifier that gets discarded after function return in mscom::AgileReference r=aklotz

Comment 13

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/acae3198b087