1486512 - MSVC cannot compile Promise-inl.h

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Nathan Froyd [:froydnj]]

We get:

 0:38.67 c:\mozilla-central\obj-aarch64-windows-mingw32\dist\include\mozilla/dom/Promise-inl.h(142): error C2244: 'mozilla::dom::Promise::ThenWithCycleCollectedArgs': unable to match function definition to an existing declaration
 0:38.67 c:\mozilla-central\obj-aarch64-windows-mingw32\dist\include\mozilla/dom/Promise-inl.h(141): note: see declaration of 'mozilla::dom::Promise::ThenWithCycleCollectedArgs'
 0:38.67 c:\mozilla-central\obj-aarch64-windows-mingw32\dist\include\mozilla/dom/Promise-inl.h(142): note: definition
 0:38.67 c:\mozilla-central\obj-aarch64-windows-mingw32\dist\include\mozilla/dom/Promise-inl.h(142): note: 'EnableIf<IsHandlerCallback<Callback,Args...>::value,mozilla::Result<RefPtr<mozilla::dom::Promise>,nsresult>>::Type mozilla::dom::Promise::ThenWithCycleCollectedArgs(Callback &&,Args &&...)'
 0:38.67 c:\mozilla-central\obj-aarch64-windows-mingw32\dist\include\mozilla/dom/Promise-inl.h(142): note: existing declarations
 0:38.67 c:\mozilla-central\obj-aarch64-windows-mingw32\dist\include\mozilla/dom/Promise-inl.h(142): note: 'EnableIf<mozilla::IsSame<already_AddRefed<mozilla::dom::Promise>,unknown-type>::value,mozilla::Result<RefPtr<mozilla::dom::Promise>,nsresult>>::Type mozilla::dom::Promise::ThenWithCycleCollectedArgs(Callback &&,Args &&...)'

Kris, I think you said you were going to take a look at this?  This is going to make compiling for AArch64 Windows with MSVC somewhat difficult... ;)

Comment 1

[Nathan Froyd [:froydnj]]

I reported a bug:

https://developercommunity.visualstudio.com/content/problem/322017/unable-to-match-function-definition-to-an-existing-1.html

I'm not super-expectant that it's going to get fixed, though.

Comment 2

[Nathan Froyd [:froydnj]]

Compiling with clang appears to be blocked on https://bugs.llvm.org/show_bug.cgi?id=38726

Comment 3

[Kris Maglione [:kmag]]

(In reply to Nathan Froyd [:froydnj] from comment #0)
> Kris, I think you said you were going to take a look at this?

I did, but that was less than 24 hours ago, on a Sunday :P

> This is going to make compiling for AArch64 Windows with MSVC somewhat
> difficult... ;)

Urgh. Are we using MSVC for that?

Comment 4

[Nathan Froyd [:froydnj]]

(In reply to Kris Maglione [:kmag] from comment #3)
> (In reply to Nathan Froyd [:froydnj] from comment #0)
> > Kris, I think you said you were going to take a look at this?
> 
> I did, but that was less than 24 hours ago, on a Sunday :P

Heh, fair enough. :)

> > This is going to make compiling for AArch64 Windows with MSVC somewhat
> > difficult... ;)
> 
> Urgh. Are we using MSVC for that?

At the moment, yes.

Comment 5

[Kris Maglione [:kmag]]

Attachment: Bug 1486512: Fix compiling Promise-inl.h on MSVC. r=froydnj

For reasions which are unclear, MSVC does not recognize the declaration and
definition of ThenWithCycleCollectedArts as matching in their previous form.
Changing both to use the same template `using` declaration for the entire
return type fixes this.

MSVC also has problems with the previous use of std::forward, which is fixed
by explicitly coercing smart pointers to their equivalent pointer types, and
moving any other type.

Comment 6

[Nathan Froyd [:froydnj]]

Comment on attachment 9004390 [details]
Bug 1486512: Fix compiling Promise-inl.h on MSVC. r=froydnj

Nathan Froyd [:froydnj] has approved the revision.

Comment 7

[Kris Maglione [:kmag]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/23e112bfaf97817122b1f3bae3e9ecf4ff9d63ef
Bug 1486512: Fix compiling Promise-inl.h on MSVC. r=froydnj

Comment 8

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/23e112bfaf97