touch-packages team mailing list archive

[Timo Jyrinki <timo.jyrinki@xxxxxxxxxxxxx>]

Trying to represent the meaningful parts of the rest of the discussion
below.

<+tronical> tsdgeos: in QQmlEnginePrivate::registerBaseTypes can you insert a qDebug() << "QObject::staticMetaObject is at" << 
&QObject::staticMetaObject; ?
<+tronical> tsdgeos: if we get the wrong address there, then maybe we have a miscompilation of QtQml somehow
< tsdgeos> tronical: yeah it's wrong there
<+tronical> tsdgeos: ok, that means there's something wrong with libQt5Qml.so
< tsdgeos> removing -O2 didn't help
<+tronical> ok, that dump looks sane though
<+tronical> in particular QObject::staticMetaObject is referenced through a R_ARM_GOT32 relocation
<+tronical> can you paste the output of objdump -TRDC /path/to/unity8 ?
< tsdgeos> yes
< tsdgeos> tronical: http://paste.ubuntu.com/9570566/
<+tronical> aha!!
<+tronical> this one has indeed a copy relocation to QObject::staticMetaObject, which it shouldn't have if it's compiled with -fPIE I think

(... -fPIE is in use ...)

<+tronical> tsdgeos: _some_ source code in the unity8 sources references QObject::staticMetaObject
<+tronical> tsdgeos: in that .o file the reference to QObject::staticMetaObject should be through the procedure linkage table, but in your case it must be an absolute reference/relocation, which will cause the linker in turn to create a so-called copy relocation for unity8 as binary. I think it shouldn't have that
< tsdgeos> builddir/tests/mocks/Unity/Indicators/moc_sharedunitymenumodel.cpp:    { &QObject::staticMetaObject, qt_meta_stringdata_SharedUnityMenuModel.data,
<+tronical> oh, that's just a test
<+tronical> still, ok, suppose it were valid, then the other question is why when loading the plugin that has QSortFilterProxyModelQML the reference to QObject::staticMetaObject isn't changed to point to the copy relocation
<+tronical> tsdgeos: could you try running your app with LD_DEBUG=bindings,symbols and collect the output? it's going to be a lot, so you could email it if it's too big for a paste
< tsdgeos> sent
<+tronical> tsdgeos: the ld output looks ok but I don't understand yet why the one file that has the QSortFilterProxyModelQML isn't relocated correctly
<+tronical> tsdgeos: that comes from libunity8-private.so, right?
<+tronical> tsdgeos: I have to leave. let's look at this early next year :)

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to ubuntu-ui-toolkit in
Ubuntu.
https://bugs.launchpad.net/bugs/1403758

Title:
  Unity8 shows black screen with Qt 5.4.0

Status in ubuntu-ui-toolkit package in Ubuntu:
  New
Status in unity8 package in Ubuntu:
  New

Bug description:
  With bug #1403511 taken care of in Qt, apps do not anymore crash with
  Qt 5.4 and device does not anymore go into reboot loop. However,
  nothing is visible on the screen.

  It seems unity8, unity8-dash etc are all running. unity8.log attached

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