Bug 109386 – Qt's Q_EXPORT macro does not support gcc's -fvisibility

Bug 109386:

Qt's Q_EXPORT macro does not support gcc's -fvi...

Alias:
Product:	kdelibs
Component:	qt
Status:	RESOLVED
Resolution:	FIXED
Target:	---

Version:	unspecified
Priority:	NOR
Severity:	wishlist

Votes:

Description From Dirk Mueller 2005-07-20 14:46:06

Version:            (using KDE Devel)
Installed from:    Compiled sources
Compiler:          gcc 4.0.1 
OS:                Linux

This is a metabug tracking the latest visibility support patch for Qt 3.3.x, to be submitted to Trolltech and included in their next maintenance release when ready.

------- Comment #1 From Dirk Mueller 2005-07-20 17:47:04 -------

Created an attachment (id=11861) [details]
patch v1

------- Comment #2 From Jure Repinc 2005-07-21 02:13:12 -------

I downloaded this patch, applied it to qt-copy and recompiled qt-copy. But when
I try to configure kdebase I still get the message:

Your GCC supports symbol visibility, but the patch for Qt supporting visibility
was not included. Therefore, GCC symbol visibility support remains disabled.

For better performance, consider including the Qt visibility supporting patch
located at:

http://bugs.kde.org/show_bug.cgi?id=109386

and recompile all of Qt and KDE. Note, this is entirely optional and
everything will continue to work just fine without it.

Configuring and compiling arts and kdelibs did not give this message.

------- Comment #3 From Dirk Mueller 2005-07-21 04:30:12 -------

can't reproduce. can you attach your config.log please? you also want to make
sure that your admin/ dir is up to date in kdebase and that you did run make -f
Makefile.cvs first.

------- Comment #4 From Jure Repinc 2005-07-21 09:56:57 -------

Created an attachment (id=11863) [details]
config.log for kdebase

This is the config.log as requested. Before compiling I did "svn up kdebase"
and my build script does habe make -f Makefile.cvs. I also tried on another
computer and I hot the same message.

------- Comment #5 From Jure Repinc 2005-07-22 13:36:33 -------

After applying this patch I have similar problems compiling kdeedu:

./QueryDlgBase.moc:106: multiple definition of `QueryDlgBase::sigEditEntry(int, int)'
./query-dialogs/.libs/libquerydlg.a(QueryDlgBase.moc.o):/home/kdedev/src/kde/build/kdeedu/kvoctrain/kvoctrain/query-dialogs/QueryDlgBase.moc.cpp:106: first defined here
./query-dialogs/.libs/libquerydlg.a(QueryDlgBase.o): In function `QueryDlgBase::qt_static_property(QObject*, int, int, QVariant*)':
./QueryDlgBase.moc:140: multiple definition of `QueryDlgBase::qt_static_property(QObject*, int, int, QVariant*)'
./query-dialogs/.libs/libquerydlg.a(QueryDlgBase.moc.o):/home/kdedev/src/kde/build/kdeedu/kvoctrain/kvoctrain/query-dialogs/QueryDlgBase.moc.cpp:140: first defined here
collect2: ld returned 1 exit status
make[4]: *** [kvoctrain] Error 1
make[4]: Leaving directory `/home/kdedev/src/kde/build/kdeedu/kvoctrain/kvoctrain'
make[3]: *** [all-recursive] Error 1
make[3]: Leaving directory `/home/kdedev/src/kde/build/kdeedu/kvoctrain/kvoctrain'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/home/kdedev/src/kde/build/kdeedu/kvoctrain'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/kdedev/src/kde/build/kdeedu'
make: *** [all] Error 2

a similar thing happens with Kopete Jabber compile.

Is this just a coincidence or is it really this patch that causes these problems?

------- Comment #6 From Philippe Rigault 2005-07-23 18:51:02 -------

I got the same as in comment#2

=============== configure output ==================
<snip>
checking whether g++ supports -fvisibility=hidden... yes
checking if Qt is patched for -fvisibility... no
<snip>

Your GCC supports symbol visibility, but the patch for Qt supporting visibility
was not included. Therefore, GCC symbol visibility support remains disabled.

===================================================

This is because the patch above only defines Q_EXPORT only for gcc >= 4.0 and I use GCC-3.4.3-22.fc3.
Why test only gcc >= 4.0 ?

------- Comment #7 From Matt Rogers 2005-07-23 19:05:54 -------

because GCC >= 4.0 is the first compiler to support visibility correctly. The
3.4.x compilers that have visibility support are just too buggy.

------- Comment #8 From Jure Repinc 2005-07-23 19:28:46 -------

Thanks for the explanation Matt. So it is best to just not use this visibility
support on systems where you use GCC 3.3 or 3.4 and only patch on systems with
4.0. Maybe this is why I get some compiling problems on my system.

------- Comment #9 From Philippe Rigault 2005-07-23 20:06:10 -------

>Thanks for the explanation Matt.
... or lack thereof. I find "just too buggy" a little lacking in details, one might also say "buggy but not so much as being blacklisted" ;-)

GCC-3.4.x does have more limited support for visibility (especially with regard to the -fvisibility-inlines-hidden flag), but at least it compiles KDE fine using the right visibility flags (tested on 3.4.0 and 3.4.1 with gcc-3.4.2.fc3 and 3.4.3.fc3)

>So it is best to just not use this visibility support on systems where you
> use GCC 3.3 or 3.4 and only patch on systems with 4.0
'configure' takes care of this for you, it will disable -fvisibility options for gcc 3.x.

Your compiler errors don't look as if they are linked to this.

------- Comment #10 From Szombathelyi György 2005-07-28 00:35:45 -------

I encountered a problem with the visibility check for Qt
The source code snippet which checks if the Q_EXPORT macro is defined includes 
<qglobal.h>. But this should be done _after_ the QT lib checks. Now every 
test for the visibility-enabled QT is positive, since the test program aborts 
with the error that qglobal.h not found.
I'll post 2 patches for arts and kdelibs, but all modules needs similar solution, I think.

------- Comment #11 From Szombathelyi György 2005-07-28 00:36:58 -------

Created an attachment (id=11958) [details]
Re-arrange the test for hidden visibility

------- Comment #12 From Szombathelyi György 2005-07-28 00:37:20 -------

Created an attachment (id=11959) [details]
Re-arrange the test for hidden visibility

------- Comment #13 From Mohd Asif Ali Rizwaan 2005-07-29 05:19:42 -------

how do i apply the patch? 

like:
patch p1 < qtpatch.txt ?

i've tried but it won't patch.

------- Comment #14 From Dirk Mueller 2005-07-29 17:46:35 -------

(From update of attachment 11863 [details])
fixed

------- Comment #15 From Rex Dieter 2005-08-08 13:58:01 -------

Is there any particular reason the patch enables visibility support only for
gcc >= 4.  AFAIK, gcc-3.4.x supports -fvisibility too.

------- Comment #16 From Dirk Mueller 2005-08-08 14:02:21 -------

only that gcc 3.4.x does not support visibility unless your distro patched it. 
and those patched gcc's are more or less broken, so we're far safer off by
disabling visibility for those who happen to use such a distro.

------- Comment #17 From Jure Repinc 2005-09-10 00:10:19 -------

When I try to compile kopete on computer with visibility patch and GCC 4.0.1 I
get this error:

linking ./kopete/kopete/config/avdevice/kcm_kopete_avdeviceconfig.la
/bin/sh ./libtool --silent --mode=link --tag=CXX g++ -Wno-long-long -Wundef
-ansi -D_XOPEN_SOURCE=500 -D_BSD_SOURCE -Wcast-align -Wconversion
-Wchar-subscripts -Wall -W -Wpointer-arith -g -O2 -Wformat-security
-Wmissing-format-attribute -Wno-non-virtual-dtor -fno-exceptions -fno-check-new
-fno-common -fvisibility=hidden -fvisibility-inlines-hidden
-DQT_CLEAN_NAMESPACE -DQT_NO_ASCII_CAST -DQT_NO_STL -DQT_NO_COMPAT
-DQT_NO_TRANSLATION -I/home/kdedev/src/kde/kdenetwork/kopete/libkopete
-I./kopete/libkopete
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/ui -I./kopete/libkopete/ui
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/private
-I/home/kdedev/kde-unstable/include -I/home/kdedev/src/kde/qt-copy/include
-I/usr/X11R6/include -DQT_THREAD_SUPPORT -D_REENTRANT -D_FILE_OFFSET_BITS=64
-no-undefined -module -avoid-version -module -no-undefined -Wl,--no-undefined
-Wl,--allow-shlib-undefined -R /home/kdedev/kde-unstable/lib -R
/home/kdedev/kde-unstable/lib -R /home/kdedev/src/kde/qt-copy/lib -R
/usr/X11R6/lib -L/home/kdedev/kde-unstable/lib
-L/home/kdedev/src/kde/qt-copy/lib -L/usr/X11R6/lib -o
./kopete/kopete/config/avdevice/kcm_kopete_avdeviceconfig.la -rpath
/home/kdedev/kde-unstable/lib/kde3 ./kopete/libkopete/libkopete.la
./kopete/libkopete/avdevice/libkopete_videodevice.la -lkutils
./kopete/kopete/config/avdevice/avdeviceconfig.lo
./kopete/kopete/config/avdevice/avdeviceconfig_videoconfig.lo
./kopete/kopete/config/avdevice/avdeviceconfig.moc.lo
./kopete/kopete/config/avdevice/.libs/avdeviceconfig.o: In function
`~AVDeviceConfig':
/home/kdedev/src/kde/kdenetwork/kopete/kopete/config/avdevice/avdeviceconfig.cpp:89:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/kopete/config/avdevice/avdeviceconfig.cpp:89:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/kopete/config/avdevice/avdeviceconfig.cpp:89:
undefined reference to `QGLWidget::~QGLWidget()'
./kopete/kopete/config/avdevice/.libs/avdeviceconfig.o: In function
`AVDeviceConfig':
/home/kdedev/src/kde/kdenetwork/kopete/kopete/config/avdevice/avdeviceconfig.cpp:47:
undefined reference to `QGLWidget::QGLWidget(QWidget*, char const*, QGLWidget
const*, unsigned int)'
/home/kdedev/src/kde/kdenetwork/kopete/kopete/config/avdevice/avdeviceconfig.cpp:47:
undefined reference to `QGLWidget::QGLWidget(QWidget*, char const*, QGLWidget
const*, unsigned int)'
collect2: ld returned 1 exit status
Error creating ./kopete/kopete/config/avdevice/kcm_kopete_avdeviceconfig.la.
Exit status 1.
cd /home/kdedev/src/kde/kdenetwork && /bin/sh
/home/kdedev/src/kde/kdenetwork/admin/missing --run autoheader
rm -f ./stamp-h1
touch /home/kdedev/src/kde/kdenetwork/config.h.in
cd . && /bin/sh ./config.status config.h
/home/kdedev/src/kde/qt-copy/bin/moc -o types.moc
/home/kdedev/src/kde/kdenetwork/kopete/protocols/jabber/libiris/iris/xmpp-im/../xmpp-im/types.cpp
Starting installation...
installing ./kopete/libkopete/avdevice/libkopete_videodevice.la 
installing ./kopete/protocols/oscar/libkopete_oscar.la 
installing ./kopete/protocols/msn/libkopete_msn_shared.la 
linking ./kopete/libkopete/avdevice/libkvideoio.la
/bin/sh ./libtool --silent --mode=link --tag=CXX g++ -Wno-long-long -Wundef
-ansi -D_XOPEN_SOURCE=500 -D_BSD_SOURCE -Wcast-align -Wconversion
-Wchar-subscripts -Wall -W -Wpointer-arith -g -O2 -Wformat-security
-Wmissing-format-attribute -Wno-non-virtual-dtor -fno-exceptions -fno-check-new
-fno-common -fvisibility=hidden -fvisibility-inlines-hidden
-DQT_CLEAN_NAMESPACE -DQT_NO_ASCII_CAST -DQT_NO_STL -DQT_NO_COMPAT
-DQT_NO_TRANSLATION -DKDE_NO_COMPAT -DQT_NO_COMPAT -DQT_NO_CAST_ASCII
-DQT_NO_ASCII_CAST -I/home/kdedev/src/kde/kdenetwork/kopete/libkopete
-I./kopete/libkopete
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/ui -I./kopete/libkopete/ui
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/private
-I/home/kdedev/src/kde/kdenetwork/kopete/libkopete/ui
-I/home/kdedev/kde-unstable/include -I/home/kdedev/src/kde/qt-copy/include
-I/usr/X11R6/include -DQT_THREAD_SUPPORT -D_REENTRANT -D_FILE_OFFSET_BITS=64
-no-undefined -L/home/kdedev/kde-unstable/lib
-L/home/kdedev/src/kde/qt-copy/lib -L/usr/X11R6/lib -version-info 1:0:0 -o
./kopete/libkopete/avdevice/libkvideoio.la -rpath /home/kdedev/kde-unstable/lib
-Wl,--no-undefined -Wl,--allow-shlib-undefined -lqt-mt -lz -lpng -lz -lm -lXext
-lX11 -lSM -lICE -lpthread -lkdecore -lGLU -lGL -lX11
./kopete/libkopete/avdevice/kxv.lo ./kopete/libkopete/avdevice/qvideo.lo
./kopete/libkopete/avdevice/qvideostream.lo
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function `QVideoStream':
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:131:
undefined reference to `QGLFormat::hasOpenGL()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:131:
undefined reference to `QGLFormat::hasOpenGL()'
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function
`QVideoStreamGLWidget':
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:540:
undefined reference to `QGLFormat::QGLFormat(int, int)'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:540:
undefined reference to `QGLWidget::QGLWidget(QGLFormat const&, QWidget*, char
const*, QGLWidget const*, unsigned int)'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:540:
undefined reference to `QGLFormat::QGLFormat(int, int)'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:540:
undefined reference to `QGLWidget::QGLWidget(QGLFormat const&, QWidget*, char
const*, QGLWidget const*, unsigned int)'
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function
`~QVideoStreamGLWidget':
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:556:
undefined reference to `QGLWidget::makeCurrent()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:560:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:560:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:556:
undefined reference to `QGLWidget::makeCurrent()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:560:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:560:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:556:
undefined reference to `QGLWidget::makeCurrent()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:560:
undefined reference to `QGLWidget::~QGLWidget()'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:560:
undefined reference to `QGLWidget::~QGLWidget()'
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function
`QVideoStreamGLWidget::initializeGL()':
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:585:
undefined reference to `QGLWidget::isValid() const'
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function `doubleBuffer':
/home/kdedev/src/kde/qt-copy/include/qgl.h:400: undefined reference to
`QGLFormat::testOption(QGL::FormatOption) const'
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function
`QVideoStreamGLWidget::initializeGL()':
/home/kdedev/src/kde/qt-copy/include/qgl.h:405: undefined reference to
`QGLFormat::testOption(QGL::FormatOption) const'
/home/kdedev/src/kde/qt-copy/include/qgl.h:410: undefined reference to
`QGLFormat::testOption(QGL::FormatOption) const'
/home/kdedev/src/kde/qt-copy/include/qgl.h:415: undefined reference to
`QGLFormat::testOption(QGL::FormatOption) const'
/home/kdedev/src/kde/qt-copy/include/qgl.h:420: undefined reference to
`QGLFormat::testOption(QGL::FormatOption) const'
./kopete/libkopete/avdevice/.libs/qvideostream.o:/home/kdedev/src/kde/qt-copy/include/qgl.h:425:
more undefined references to `QGLFormat::testOption(QGL::FormatOption) const'
follow
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function
`QVideoStreamGLWidget::initializeGL()':
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:595:
undefined reference to `QGLFormat::plane() const'
/home/kdedev/src/kde/kdenetwork/kopete/libkopete/avdevice/qvideostream.cpp:598:
undefined reference to `QGLWidget::qglClearColor(QColor const&) const'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTI20QVideoStreamGLWidget[typeinfo
for QVideoStreamGLWidget]+0x8): undefined reference to `typeinfo for QGLWidget'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0xc): undefined reference to `QGLWidget::className()
const'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x10): undefined reference to
`QGLWidget::qt_cast(char const*)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x14): undefined reference to
`QGLWidget::qt_invoke(int, QUObject*)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x18): undefined reference to
`QGLWidget::qt_emit(int, QUObject*)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1c): undefined reference to
`QGLWidget::qt_property(int, int, QVariant*)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0xac): undefined reference to
`QGLWidget::setMouseTracking(bool)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x108): undefined reference to
`QGLWidget::reparent(QWidget*, unsigned int, QPoint const&, bool)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x148): undefined reference to
`QGLWidget::paintEvent(QPaintEvent*)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x150): undefined reference to
`QGLWidget::resizeEvent(QResizeEvent*)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1c0): undefined reference to
`QGLWidget::makeCurrent()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1c4): undefined reference to
`QGLWidget::swapBuffers()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1c8): undefined reference to
`QGLWidget::setFormat(QGLFormat const&)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1cc): undefined reference to
`QGLWidget::setContext(QGLContext*, QGLContext const*, bool)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1d0): undefined reference to
`QGLWidget::renderPixmap(int, int, bool)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1d4): undefined reference to
`QGLWidget::grabFrameBuffer(bool)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1d8): undefined reference to
`QGLWidget::makeOverlayCurrent()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1dc): undefined reference to
`QGLWidget::updateGL()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1e0): undefined reference to
`QGLWidget::updateOverlayGL()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1ec): undefined reference to `QGLWidget::paintGL()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1f0): undefined reference to
`QGLWidget::initializeOverlayGL()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1f4): undefined reference to
`QGLWidget::resizeOverlayGL(int, int)'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1f8): undefined reference to
`QGLWidget::paintOverlayGL()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x1fc): undefined reference to `QGLWidget::glInit()'
./kopete/libkopete/avdevice/.libs/qvideostream.o:(.gnu.linkonce.d._ZTV20QVideoStreamGLWidget[vtable
for QVideoStreamGLWidget]+0x200): undefined reference to `QGLWidget::glDraw()'
./kopete/libkopete/avdevice/.libs/qvideostream.o: In function
`QGLWidget::metaObject() const':
/home/kdedev/src/kde/qt-copy/include/qgl.h:274: undefined reference to
`QGLWidget::staticMetaObject()'
collect2: ld returned 1 exit status
Error creating ./kopete/libkopete/avdevice/libkvideoio.la. Exit status 1.

------- Comment #18 From Nicolas Goutte 2005-09-10 15:58:27 -------

As far as I have understood, Qt4 works with -fvisibility

------- Comment #19 From Matt Rogers 2005-09-10 16:03:53 -------

Nicolas: next time, read the bug report. This is about getting visibility
support added for Qt3.

------- Comment #20 From Nicolas Goutte 2005-09-10 16:15:45 -------

On Saturday 10 September 2005 16:03, Matt Rogers wrote:
[bugs.kde.org quoted mail]

Do you really thing that it will be still done?

Qt 3 will probably not much updated by Trolltech anymore.

KDE 3.5 is in feature freeze and can handle a unpatched Qt.

So I do not know why thi sbug is still open.

Have a nice day!

------- Comment #21 From Thiago Macieira 2005-09-10 18:01:48 -------

Nicolas: TT has promised an updated version of Qt3 with visibility support.
Besides, we *do* want to support patched Qt as in qt-copy with visibility
support, and that's what this bug is about.

------- Comment #22 From Jure Repinc 2005-09-13 09:44:33 -------

Is this patch stil OK for the new Qt 3.3.5? Or is visibility support now
integrated officialy by Trolltech?

------- Comment #23 From Dirk Mueller 2005-09-13 09:52:02 -------

still applying against Qt 3.3.5

------- Comment #24 From Diego Pettenò 2005-09-27 13:51:30 -------

The test seems to pass, at least for arts and kdelibs from within emerge, using
Gentoo, QT 3.3.5 and GCC 4, so -fvisibility=hidden *is* enabled, but then arts
crashes within STL, because neither STL is safe wrt -fvisibility=hidden.
Disabling the visibility check entirely made it work fine (but it required to
rebuild both arts and kdelibs).

Also, kmail linked against the broken kdelibs started crashing within library
calls, recompiled, and worked fine.

-fvisibility=hidden creates problem not only to Qt but also to every C++
library which KDE apps links against, it's probably not safe to enable at least
on some cases. Having at least a --disable-visibility switch on configure would
help, I think.

------- Comment #25 From Dirk Mueller 2005-09-27 14:11:59 -------

thats nonsense, you're facing a libstdc++ bug that is already fixed for ages,
so feel free to report it against your distro

------- Comment #26 From Diego Pettenò 2005-09-27 14:23:42 -------

It's not limited to Gentoo (btw I'm using a 4.0.2 snapshot now, but the same
problem was on alpha1, after which I updated to this version, so the problem
should not be in gcc) as seems like KUbuntu's binaries are suffering from the
same problem.

------- Comment #27 From Christopher Martin 2005-10-01 16:00:24 -------

Diego is correct. Without certain patches for gcc used by Mandrake and SuSE,
even the latest gcc 4.0.2 does not generate good code when using
-fvisibility=hidden. See:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19664
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19520

Since Debian (and most other distros, especially Debian derivatives, I imagine)
does not use the relevant gcc visibility patches applied by Mandrake and SuSE,
enabling KDE visibility results in aRts crashes, amongst others, exactly as
Diego reported. More generally, many shared objects become marked with TEXTREL,
suggesting rather strongly that something is wrong, and apparently causing
linking problems on architectures that don't support non-PIC libs.

------- Comment #28 From Koos Vriezen 2005-10-02 15:36:58 -------

Created an attachment (id=12809) [details]
Extended patch for reduces symbols for libqt-mt itself

This patch extends Dirk's by also applying -fvisibility to Qt itself. It saves
about 6000 symbols, mainly W types. This patch was posted on kde-core-devel 8
may '05 but that one needed manual tweaking in src/tools/qconfig.cpp after
'configure', that is now fixed in this version. Works for me since 8 may, but I
only build Qt with 'make sub-tools'
(According to Christopher bug links above, don't use this on amd64 systems
while these still open for your compiler)

------- Comment #29 From Diego Pettenò 2005-10-05 00:39:33 -------

I'm going to test with this patch and newly patched GCC, maybe this time it
will work (hopefully?).

Just to know then, what would happen if some KDE program with visibility
enabled links to a C++ library that is not aware of visibility?
If that crashes (as does libstdc++), is enough of a reason to disable it, from
my point of view.
Nobody can ensure that all and every library used by KDE and KDE software is
visibility aware :/

------- Comment #30 From Dirk Mueller 2005-10-05 09:47:12 -------

it requires to patch the inclusion of those header files to reset visibility to
default. usually things don't crash (e.g. libFAM), when they are in C++ but
only export a C interface. There is only a problem when a C++ library exports a
C++ interface that needs to be casted upstream.

------- Comment #31 From Diego Pettenò 2005-10-05 13:33:47 -------

Created an attachment (id=12862) [details]
Kooka failure log

FWIW, after patching qt, enabling the support and recompiling KDE, kooka fails
with the attached log.
Have to look if it's just Kooka or if the visibility stuff broke something.

At least, artsplay now doesn't segfault, so that problem seems resolved.

------- Comment #32 From Koos Vriezen 2005-10-05 21:11:46 -------

Strange, KDE_ENABLE_HIDDEN_VISIBILITY macro isn't defined in configure.in.in in
kdegraphics (at least not in the 3.5 branch .. or 3.4 branch). Did you add it
yourself?

------- Comment #33 From Diego Pettenò 2005-10-05 21:21:58 -------

No, just gone through with emerge, after removing the tinkering with visibility
in the eclass to have a mostly "as configure say" environment.
If it does not inherit CXXFLAGS from one of its dependencies (after the
configure), the only cause can be a problem of mixing libraries with visibility
enabled with code that does not support it.
I'll retry after all of the rest of the packages are compiled, but that might
mean that something else needs to be fixed before enabling the feature for
stable users.

Still no hope to get a --disable-visibility option, with an enabled default?

------- Comment #34 From Dirk Mueller 2005-10-05 22:23:43 -------

ok, then you screwed something up. there is no visibility enabled in
kdegraphics because the module doesn't support it, so if you have visibility
enabled in your ebuild then your ebuild is broken.

------- Comment #35 From Diego Pettenò 2005-10-05 22:31:47 -------

If configure does not enable it, the ebuild does not enable it for sure.
So the problem is not this side, it might be a problem of a system partially upgraded to visibility and partially still to update, or it might be a problem with kdegraphics and the other libraries, still to see which one it is, as soon as I'll be clear of what the cause is, I'll report back.

------- Comment #36 From Diego Pettenò 2005-10-06 10:59:37 -------

Ok the kooka problem was probably unrelated or due to the mixed environment,
re-tried compiling after the rest of KDE compiled, and it gone fine.

Still, I have Kontact crashing while loading gpg-signed mails (but KMail on its
own works fine) and artsd crash again (GCC is 4.0.2-r1, patched with Fedora's
patches as Christopher told).

------- Comment #37 From Koos Vriezen 2005-10-07 13:45:28 -------

Are backtraces of these crashes available somewhere? Probably overlooked, but
what is your KDE version? And your arch is x64, right?

------- Comment #38 From Diego Pettenò 2005-10-07 13:55:27 -------

Created an attachment (id=12906) [details]
kontact-backtrace

Here is the kontact one, arts doesn't call Dr Konqui so it's a bit tricky, gdb
gets mostly ?? because I haven't built it with debug enabled, yet.

Yep I'm on amd64, with patched GCC as said, KDE version 3.5_beta1.

------- Comment #39 From Ali Akcaagac 2005-10-09 14:13:32 -------

Hello,

I was compiling KDE 3.5 SVN over night and saw this stuff being mentioned in the configure process. Could someone please inform me, which of the patches listed here is the correct one to apply and maybe tell me why this hasn't been added to the qt-copy/patches subdir for automagic apply ? Would save a lot of trouble in case someone forgets to manually patch it as I did for example.

------- Comment #40 From Diego Pettenò 2005-10-12 01:20:59 -------

At least other patches are needed to Qt.

pinentry (from GnuPG project) breaks because it can't find qt_hebrew_keyboard_hack (and doesn't compile) as it's not exported.

Also, koffice-libs is killed this way:

.libs/korichtext.o: In function `KoTextString::checkBidi() const':
korichtext.cpp:(.text+0x2704): undefined reference to `QTextEngine::QTextEngine(QString const&, QFontPrivate*)'
korichtext.cpp:(.text+0x273e): undefined reference to `QTextEngine::itemize(int)'
korichtext.cpp:(.text+0x2747): undefined reference to `QTextEngine::attributes()'
korichtext.cpp:(.text+0x288b): undefined reference to `QTextEngine::~QTextEngine()'
korichtext.cpp:(.text+0x2934): undefined reference to `QTextEngine::~QTextEngine()'
collect2: ld returned 1 exit status
make[4]: *** [libkotext.la] Error 1

the same goes for both koffice 1.4.1 and 1.4.2.

------- Comment #41 From Dirk Mueller 2005-10-12 09:07:47 -------

not really, this is not what the bug report is about. I don't know why somebody
added a patch to compile Qt with -fvisibility=hidden, but that is binary
incompatible and shouldn't be done. If you do that, its your own fault.

------- Comment #42 From Diego Pettenò 2005-10-12 12:54:24 -------

If something is not being exported properly, we'll fall in the same problem we
had with 3.4.0 and 3.4.1 releases with dynamic_cast.

------- Comment #43 From Dirk Mueller 2005-10-12 13:14:40 -------

sure, thats why Q_EXPORT has been fixed. however this has nothing to do with
missing exports from a visibility-patched libqt.

------- Comment #44 From Koos Vriezen 2005-10-12 21:08:44 -------

"why somebody added a patch to compile Qt with -fvisibility=hidden, but that is
binary incompatible"
I was hoping for some more testing for this patch. I've recompiled debian's
libqt-mt/unstable package and everything _seems_ to work quite nicely for the
KDE apps I use. Which isn't much more than kdelibs/kdebase actually, but are
not recompiled by me. That's why I considered extending the v1 patch on topic.
So why is it BIC (besides the missed exports of course)?

------- Comment #45 From Stefan Vunckx 2005-10-17 15:10:10 -------

Created an attachment (id=13025) [details]
backtrace of kmail crash when sending out mail

I have KDE/Qt compiled from SVN with the visibility patch, and when I try to
send mail, kmail crashes :/

Its due to visibility; when I re-compile Qt+kdelibs+kmail, the problem
disappears ... Ive attached the backtrace.

There's also another problem (dont know if its related, but it IS related to
visibility); I cant edit the to/cc field in kmail's composer, it crashes if I
try to do so (or if I push the select button for addressbook), but drkonqui
isnt called then, so I cant produce backtrace; only lo from console output:
...
kabc: StdAddressBook::self()
kmail: RecipientsPicker::insertCollection() Distribution Lists	index: 2
*** KMail got signal 11 (Crashing)

------- Comment #46 From Rex Dieter 2005-10-17 15:13:34 -------

Re: comment #45, Stephan, if you've found a kmail bug/crash, IMO, then file it
against kmail... it has no place being mentioned here against kdelibs/qt.

------- Comment #47 From Raul Bob 2005-10-19 12:43:30 -------

I have tried "patch v1" against qt3.3.5 but it seems to me that this release is
already patched.
[root@qt-x11-free-3.3.5]# patch < ./qt_visibility.txt
can't find file to patch at input line 5
Perhaps you should have used the -p or --strip option?
The text leading up to this was:
--------------------------
|Index: src/kernel/qgplugin.h
|===================================================================
|--- src/kernel/qgplugin.h      (revision 423270)
|+++ src/kernel/qgplugin.h      (working copy)
--------------------------
File to patch: src/kernel/qgplugin.h
patching file src/kernel/qgplugin.h
Reversed (or previously applied) patch detected!  Assume -R? [n]
Apply anyway? [n]
Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file src/kernel/qgplugin.h.rej
can't find file to patch at input line 55
Perhaps you should have used the -p or --strip option?
The text leading up to this was:
--------------------------
|Index: src/tools/qglobal.h
|===================================================================
|--- src/tools/qglobal.h        (revision 423270)
|+++ src/tools/qglobal.h        (working copy)
--------------------------
File to patch: src/tools/qglobal.h
patching file src/tools/qglobal.h
Reversed (or previously applied) patch detected!  Assume -R? [n]
Apply anyway? [n]
Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file src/tools/qglobal.h.rej

------- Comment #48 From Koos Vriezen 2005-10-19 20:30:57 -------

Created an attachment (id=13069) [details]
Add exports reported by Diego Pettenò (use at own risk :)

------- Comment #49 From Dirk Mueller 2008-08-18 01:30:58 -------

qt 4.x implements visibility macros now.

Platform:	Compiled Sources
OS:	Linux
Keywords:
URL:

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Reporter:	Dirk Mueller
Assigned To:	Dirk Mueller
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Attachments
patch v1 (2.23 KB, patch) 2005-07-20 17:47, Dirk Mueller	Details
config.log for kdebase (520.45 KB, text/plain) 2005-07-21 09:56, Jure Repinc	Details
Re-arrange the test for hidden visibility (725 bytes, patch) 2005-07-28 00:36, Szombathelyi György	Details
Re-arrange the test for hidden visibility (499 bytes, patch) 2005-07-28 00:37, Szombathelyi György	Details
Extended patch for reduces symbols for libqt-mt itself (5.20 KB, patch) 2005-10-02 15:36, Koos Vriezen	Details
Kooka failure log (8.92 KB, text/plain) 2005-10-05 13:33, Diego Pettenò	Details
kontact-backtrace (2.35 KB, text/plain) 2005-10-07 13:55, Diego Pettenò	Details
backtrace of kmail crash when sending out mail (5.52 KB, application/octet-stream) 2005-10-17 15:10, Stefan Vunckx	Details
Add exports reported by Diego Pettenò (use at own risk :) (5.93 KB, patch) 2005-10-19 20:30, Koos Vriezen	Details
Hide Obsolete (4) View All Add an attachment (proposed patch, testcase, etc.)

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