Bug 83976 – [Qt] Fix the build for GCC 4.7

• Status: RESOLVED
• Resolution: INVALID
• Component: WebKit Qt

Compilation of qtwebkit (r114202) fails:

g++ -c -Wall -Wextra -Wreturn-type -fno-strict-aliasing -Wchar-subscripts -Wformat-security -Wreturn-type -Wno-unused-parameter -Wno-sign-compare -Wno-switch -Wno-switch-enum -Wundef -Wmissing-noreturn -Winit-self -m64 -pipe -Werror -Wno-c++0x-compat -ffunction-sections -fdata-sections -march=k8-sse3 -O2 -pipe -fstack-protector --param=ssp-buffer-size=4 -D_FORTIFY_SOURCE=2 -pthread -pthread -pthread -pthread -pthread -pthread -pthread -pthread -D_REENTRANT -fPIC -DENABLE_REQUEST_ANIMATION_FRAME=1 -DENABLE_DOWNLOAD_ATTRIBUTE=1 -DENABLE_WEBGL=1 -DENABLE_3D_RENDERING=1 -DENABLE_ACCELERATED_2D_CANVAS=1 -DENABLE_ANIMATION_API=1 -DENABLE_BLOB=1 -DENABLE_SQL_DATABASE=1 -DENABLE_FILTERS=1 -DENABLE_FTPDIR=1 -DENABLE_FULLSCREEN_API=1 -DENABLE_GEOLOCATION=1 -DENABLE_ICONDATABASE=1 -DENABLE_INPUT_SPEECH=1 -DENABLE_INPUT_TYPE_DATE=1 -DENABLE_INPUT_TYPE_DATETIME=1 -DENABLE_INPUT_TYPE_DATETIMELOCAL=1 -DENABLE_INPUT_TYPE_MONTH=1 -DENABLE_INPUT_TYPE_TIME=1 -DENABLE_INPUT_TYPE_WEEK=1 -DENABLE_JAVASCRIPT_DEBUGGER=1 -DENABLE_LINK_PREFETCH=1 -DENABLE_MATHML=1 -DENABLE_MEDIA_SOURCE=1 -DENABLE_METER_TAG=1 -DENABLE_MHTML=1 -DENABLE_MICRODATA=1 -DENABLE_PAGE_VISIBILITY_API=1 -DENABLE_PROGRESS_TAG=1 -DENABLE_SHARED_WORKERS=1 -DENABLE_STYLE_SCOPED=1 -DENABLE_SVG=1 -DENABLE_SVG_DOM_OBJC_BINDINGS=1 -DWTF_USE_TILED_BACKING_STORE=1 -DENABLE_TOUCH_EVENTS=1 -DENABLE_TOUCH_ICON_LOADING=1 -DENABLE_WEB_SOCKETS=1 -DENABLE_WEB_TIMING=1 -DENABLE_WORKERS=1 -DENABLE_XSLT=1 -DWTF_USE_QT4_UNICODE=1 -DENABLE_SVG_FONTS=0 -DHAVE_FONTCONFIG=1 -DENABLE_GAMEPAD=0 -DENABLE_CHANNEL_MESSAGING=1 -DENABLE_DIRECTORY_UPLOAD=0 -DENABLE_FILE_SYSTEM=0 -DENABLE_QUOTA=0 -DENABLE_DASHBOARD_SUPPORT=0 -DENABLE_CSS_FILTERS=1 -DENABLE_SHADOW_DOM=0 -DENABLE_DETAILS=1 -DENABLE_LEGACY_NOTIFICATIONS=1 -DENABLE_NOTIFICATIONS=1 -DENABLE_INPUT_TYPE_COLOR=0 -DENABLE_SCRIPTED_SPEECH=0 -DENABLE_INSPECTOR=1 -DENABLE_WEB_AUDIO=0 -DENABLE_MEDIA_STATISTICS=0 -DENABLE_MEDIA_STREAM=0 -DENABLE_VIDEO_TRACK=0 -DENABLE_TOUCH_ADJUSTMENT=1 -DENABLE_FAST_MOBILE_SCROLLING=1 -DWTF_USE_QT_IMAGE_DECODER=1 -DENABLE_DATALIST=1 -DENABLE_NETSCAPE_PLUGIN_API=1 -DPLUGIN_ARCHITECTURE_UNSUPPORTED=1 -DHAVE_QSTYLE=1 -DENABLE_ORIENTATION_EVENTS=1 -DENABLE_DEVICE_ORIENTATION=1 -DENABLE_GESTURE_EVENTS=1 -DENABLE_VIDEO=1 -DWTF_USE_GSTREAMER=1 -DHAVE_QQUICK1=1 -DQT_MAKEDLL -DBUILDING_QT__=1 -DNDEBUG -DBUILDING_QtWebKit -DBUILDING_WEBKIT -DQT_ASCII_CAST_WARNINGS -DXP_UNIX -DENABLE_NETSCAPE_PLUGIN_METADATA_CACHE=1 -DENABLE_GLIB_SUPPORT=1 -DWTF_USE_TEXTURE_MAPPER=1 -DWTF_USE_TEXTURE_MAPPER_GL=1 -DENABLE_GLIB_SUPPORT=1 -DQT_NO_DEBUG -DQT_SQL_LIB -DQT_XMLPATTERNS_LIB -DQT_OPENGL_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt/mkspecs/linux-g++-64 -I../../../Source -I/usr/include/QtCore -I/usr/include/QtNetwork -I/usr/include/QtGui -I/usr/include/QtOpenGL -I/usr/include/QtXmlPatterns -I/usr/include/QtSql -I/usr/include -I/usr/include/QtSensors -I/usr/include/QtLocation -I. -I../../../Source/WebKit/qt/Api -I../../../Source/WebKit/qt/WebCoreSupport -I../../../Source/WTF/wtf/qt -I../../../Source -I/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/WebKitBuild/Release/Source/include -I../../../Source/WebCore -I../../../Source/WebCore/Modules/filesystem -I../../../Source/WebCore/Modules/geolocation -I../../../Source/WebCore/Modules/indexeddb -I../../../Source/WebCore/Modules/webaudio -I../../../Source/WebCore/Modules/webdatabase -I../../../Source/WebCore/Modules/websockets -I../../../Source/WebCore/accessibility -I../../../Source/WebCore/bindings -I../../../Source/WebCore/bindings/generic -I../../../Source/WebCore/bridge -I../../../Source/WebCore/bridge/qt -I../../../Source/WebCore/css -I../../../Source/WebCore/dom -I../../../Source/WebCore/dom/default -I../../../Source/WebCore/editing -I../../../Source/WebCore/fileapi -I../../../Source/WebCore/history -I../../../Source/WebCore/html -I../../../Source/WebCore/html/canvas -I../../../Source/WebCore/html/parser -I../../../Source/WebCore/html/shadow -I../../../Source/WebCore/html/track -I../../../Source/WebCore/inspector -I../../../Source/WebCore/loader -I../../../Source/WebCore/loader/appcache -I../../../Source/WebCore/loader/archive -I../../../Source/WebCore/loader/cache -I../../../Source/WebCore/loader/icon -I../../../Source/WebCore/mathml -I../../../Source/WebCore/notifications -I../../../Source/WebCore/page -I../../../Source/WebCore/page/animation -I../../../Source/WebCore/page/qt -I../../../Source/WebCore/page/scrolling -I../../../Source/WebCore/platform -I../../../Source/WebCore/platform/animation -I../../../Source/WebCore/platform/audio -I../../../Source/WebCore/platform/graphics -I../../../Source/WebCore/platform/graphics/filters -I../../../Source/WebCore/platform/graphics/filters/arm -I../../../Source/WebCore/platform/graphics/opengl -I../../../Source/WebCore/platform/graphics/qt -I../../../Source/WebCore/platform/graphics/surfaces -I../../../Source/WebCore/platform/graphics/texmap -I../../../Source/WebCore/platform/graphics/transforms -I../../../Source/WebCore/platform/image-decoders -I../../../Source/WebCore/platform/leveldb -I../../../Source/WebCore/platform/mock -I../../../Source/WebCore/platform/network -I../../../Source/WebCore/platform/network/qt -I../../../Source/WebCore/platform/qt -I../../../Source/WebCore/platform/sql -I../../../Source/WebCore/platform/text -I../../../Source/WebCore/platform/text/transcoder -I../../../Source/WebCore/plugins -I../../../Source/WebCore/rendering -I../../../Source/WebCore/rendering/mathml -I../../../Source/WebCore/rendering/style -I../../../Source/WebCore/rendering/svg -I../../../Source/WebCore/storage -I../../../Source/WebCore/svg -I../../../Source/WebCore/svg/animation -I../../../Source/WebCore/svg/graphics -I../../../Source/WebCore/svg/graphics/filters -I../../../Source/WebCore/svg/properties -I../../../Source/WebCore/testing -I/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/Source/WebCore/websockets -I../../../Source/WebCore/workers -I../../../Source/WebCore/xml -I../../../Source/WebCore/xml/parser -I../../../Source/ThirdParty -I../../../Source/WebCore/bridge/jsc -I../../../Source/WebCore/bindings/js -I/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/Source/WebCore/bindings/js/specialization -I../../../Source/WebCore/bridge/c -I../../../Source/WebCore/testing/js -IWebCore/generated -I../../../Source/WebCore/platform/graphics/gstreamer -I/usr/src/3rdparty/sqlite/ -I../../../Source/JavaScriptCore -I../../../Source -I../../../Source/WTF -I../../../Source/JavaScriptCore/assembler -I../../../Source/JavaScriptCore/bytecode -I../../../Source/JavaScriptCore/bytecompiler -I../../../Source/JavaScriptCore/heap -I../../../Source/JavaScriptCore/dfg -I../../../Source/JavaScriptCore/debugger -I../../../Source/JavaScriptCore/interpreter -I../../../Source/JavaScriptCore/jit -I../../../Source/JavaScriptCore/llint -I../../../Source/JavaScriptCore/parser -I../../../Source/JavaScriptCore/profiler -I../../../Source/JavaScriptCore/runtime -I../../../Source/JavaScriptCore/tools -I../../../Source/JavaScriptCore/yarr -I../../../Source/JavaScriptCore/API -I../../../Source/JavaScriptCore/ForwardingHeaders -IJavaScriptCore/generated -I../../../Source -I../../../Source/WTF -I/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/Source/WTF/gobject -I/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/Source/WTF/qt -I/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/Source/WTF/unicode -I../../../Source/WTF/wtf -I/usr/X11R6/include -I/usr/include -I/usr/include/QtMobility -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/gstreamer-0.10 -I/usr/include/libxml2 -I/usr/X11R6/include -I../../../Source -I. -o obj/release/DeviceMotionProviderQt.o ../../../Source/WebKit/qt/WebCoreSupport/DeviceMotionProviderQt.cpp
../../../Source/WebKit/qt/WebCoreSupport/DeviceMotionClientQt.cpp: In destructor ‘virtual WebCore::DeviceMotionClientQt::~DeviceMotionClientQt()’:
../../../Source/WebKit/qt/WebCoreSupport/DeviceMotionClientQt.cpp:35:12: грешка: deleting object of polymorphic class type ‘WebCore::DeviceMotionProviderQt’ which has non-virtual destructor might cause undefined behaviour [-Werror=delete-non-virtual-dtor]
cc1plus: all warnings being treated as errors
make[3]: *** [obj/release/DeviceMotionClientQt.o] Error 1
make[3]: *** Waiting for unfinished jobs....
../../../Source/WebKit/qt/WebCoreSupport/DeviceMotionProviderQt.cpp: In destructor ‘WebCore::DeviceMotionProviderQt::~DeviceMotionProviderQt()’:
../../../Source/WebKit/qt/WebCoreSupport/DeviceMotionProviderQt.cpp:39:12: грешка: deleting object of polymorphic class type ‘WebCore::DeviceOrientationProviderQt’ which has non-virtual destructor might cause undefined behaviour [-Werror=delete-non-virtual-dtor]
cc1plus: all warnings being treated as errors
make[3]: *** [obj/release/DeviceMotionProviderQt.o] Error 1
make[3]: Leaving directory `/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/WebKitBuild/Release/Source'
make[2]: *** [sub-api-pri-make_default-ordered] Error 2
make[2]: Leaving directory `/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/WebKitBuild/Release/Source'
make[1]: *** [sub-Source-QtWebKit-pro-make_default-ordered] Error 2
make[1]: Leaving directory `/home/mladen/Programi/pkgbuilds/qtwebkit/qtwebkit/src/WebKit-r114202/WebKitBuild/Release'
make: *** [incremental] Error 2

gcc version 4.7.0 20120407
Qt compiled with the gcc version stated above.

[Csaba Osztrogonác]

note: r114202 is absolutely unrelated change, it isn't the culprit for this build breakage.

[Andras Becsi]

Created attachment 137344 [details]
proposed patch

[Andras Becsi]

(In reply to comment #1)
> note: r114202 is absolutely unrelated change, it isn't the culprit for this build breakage.

That is right. This code is only compiled if qt-mobility is present, that is why it slipped my attention.

Thanks for reporting.

[Simon Hausmann]

Comment on attachment 137344 [details]
proposed patch

I don't think the virtual destructor is required here in WebKit, it seems the bug is actually in qtsensors, which defines a class with virtual methods but not virtual destructor.

[Simon Hausmann]

I've filed https://codereview.qt-project.org/#change,23425

I've applied the patch from Comment #2 and successfully compiled.

[Andras Becsi]

(In reply to comment #4)
> (From update of attachment 137344 [details])
> I don't think the virtual destructor is required here in WebKit, it seems the bug is actually in qtsensors, which defines a class with virtual methods but not virtual destructor.

You are right, this just suppresses the warning.
I'm closing this as invalid.