577344 - warning C4743: 'const mozilla::layers::ImageLayer::`vftable'' has different size

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Ryan VanderMeulen [:RyanVM]]

Noticed this today when building. Not sure when this first appeared, but it must have been within the last few days.
warning C4743: 'const mozilla::layers::ImageLayer::`vftable'' has different size in 'c:\mozbuild\mozilla-central\content\base\src\nsDocument.cpp' and 'c:\mozbuild\mozilla-central\layout\build\nsLayoutModule.cpp': 24 and 20 bytes
warning C4743: 'const mozilla::layers::ColorLayer::`vftable'' has different size in 'c:\mozbuild\mozilla-central\content\base\src\nsDocument.cpp' and 'c:\mozbuild\mozilla-central\layout\build\nsLayoutModule.cpp': 32 and 28 bytes
warning C4743: 'const mozilla::layers::CanvasLayer::`vftable'' has different size in 'c:\mozbuild\mozilla-central\content\base\src\nsDocument.cpp' and 'c:\mozbuild\mozilla-central\layout\build\nsLayoutModule.cpp': 32 and 28 bytes
warning C4743: 'const mozilla::layers::ThebesLayer::`vftable'' has different size in 'c:\mozbuild\mozilla-central\content\base\src\nsDocument.cpp' and 'c:\mozbuild\mozilla-central\layout\build\nsLayoutModule.cpp': 28 and 24 bytes
warning C4743: 'const mozilla::layers::ContainerLayer::`vftable'' has different size in 'c:\mozbuild\mozilla-central\content\base\src\nsDocument.cpp' and 'c:\mozbuild\mozilla-central\layout\build\nsLayoutModule.cpp': 32 and 28 bytes

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

My guess would be that this is related to NS_LAYER_DECL_NAME -- could either DEBUG or PR_LOGGING be defined differently between some of these files?

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Must be PR_LOGGING

Comment 3

[Ryan VanderMeulen [:RyanVM]]

Attachment: Define extra virtual function unconditionally

After some hand holding by dholbert, it appeared that the fix was simply to turn PR_LOGGING on in nsLayoutModule.cpp as it is currently in nsDocument.cpp. However, doing that causes the same warning to appear in a lot of other situations instead for every other file where PR_LOGGING isn't enabled. Per conversation with roc on IRC, it was decided to just enable the extra virtual function unconditionally instead.

Comment 4

[Ryan VanderMeulen [:RyanVM]]

Attachment: Define extra virtual function unconditionally

*sigh* Would have helped if I'd tried compiling that before posting. This one actually builds!

Comment 5

[Dão Gottwald [:dao]]

http://hg.mozilla.org/mozilla-central/rev/a0a4df1ca019