1298171 - clang-cl warning: taking the address of a temporary in DrawTargetD2D1.cpp

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Nathan Froyd [:froydnj]]

clang-cl complains thusly:

c:/m-c/gfx/2d/DrawTargetD2D1.cpp(1435,62):  error: taking the address of a temporary object of type 'D2D1_BITMAP_PROPERTIES1' [-Waddress-of-temporary]
      mDC->CreateBitmap(mBitmap->GetPixelSize(), nullptr, 0, &D2D1::BitmapProperties1(D2D1_BITMAP_OPTIONS_TARGET, D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED)), getter_AddRefs(tmpBitmap));
                                                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You don't want to do this in general, because that temporary will be destroyed after the function call, which might lead to unexpected results.  I think in this case it is safe, as CreateBitmap isn't storing the pointer anywhere, but we should still fix it.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

Yeah, moving the BitmapProperties1 out into a named variable will make the line shorter too.

Comment 2

[Nathan Froyd [:froydnj]]

Attachment: Bug 1298171 - store result of BitmapProperties1 in a temporary to avoid warnings;

Review commit: https://reviewboard.mozilla.org/r/74630/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/74630/

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 8785423 [details]
Bug 1298171 - store result of BitmapProperties1 in a temporary to avoid warnings;

https://reviewboard.mozilla.org/r/74630/#review72458

Comment 4

[Nathan Froyd [:froydnj]]

Comment on attachment 8785423 [details]
Bug 1298171 - store result of BitmapProperties1 in a temporary to avoid warnings;

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/74630/diff/1-2/

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d3edbeffc36b
store result of BitmapProperties1 in a temporary to avoid warnings; r=jrmuizel

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/d3edbeffc36b