Bug 350674

Summary:	KDevelop with Clang backend crash when trying to show hint resolving unknown declaration
Product:	[Applications] kdevelop	Reporter:	Oleksandr Senkovych <bjsenya>
Component:	Language Support: CPP (old)	Assignee:	kdevelop-bugs-null
Status:	RESOLVED FIXED
Severity:	crash
Priority:	NOR
Version First Reported In:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:	http://commits.kde.org/kdev-clang/cb348e381c6d3dc97c2436ed10bd9d4588d3bc92	Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Updated patch

Description Oleksandr Senkovych 2015-07-27 17:42:22 UTC

If there's unknown declaration found in source code, KDevelop will crash trying to show problem resolution box. 



Reproducible: Always

Steps to Reproduce:
1. Create new project
2. Write random words in cpp file



Proposed patch: http://pastebin.com/AgSggpXm

Comment 1 Kevin Funk 2015-07-27 18:20:20 UTC

Interesting. Could you post the original backtrace for reference?

Comment 2 Oleksandr Senkovych 2015-07-28 08:46:12 UTC

#1 0x00007fff67539ad3 in QConcatenable<QLatin1String>::appendTo (a="\000.h\000.hpp\000.H\000.hh\000hxx\000tlh\000h++\000\005", '\000' <repeats 11 times>, "QStringList {anonymous}::scanIncludePaths(const QString&, const QDir&, int)", '\000' <repeats 53 times>, "KDevelop::DocumentRange {anonymo"..., out=@0x7fffffffcc08: 0xda8df0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qstringbuilder.h:234
#2 0x00007fff6753ca95 in QConcatenable<QStringBuilder<QString, QLatin1String> >::appendTo<QChar> (p=..., out=@0x7fffffffcc08: 0xda8df0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qstringbuilder.h:366
#3 0x00007fff6753b441 in QStringBuilder<QString, QLatin1String>::convertTo<QString> (this=0x7fffffffcd30) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qstringbuilder.h:112
#4 0x00007fff6753a27b in QStringBuilder<QString, QLatin1String>::operator QString (this=0x7fffffffcd30) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qstringbuilder.h:125
#5 0x00007fff675365c7 in (anonymous namespace)::scanIncludePaths (identifier="adsf", dir=..., maxDepth=3) at /home/blackjack/projects/other/kdev-clang/duchain/unknowndeclarationproblem.cpp:96
#6 0x00007fff67536a63 in (anonymous namespace)::scanIncludePaths (identifier=..., includes={...}) at /home/blackjack/projects/other/kdev-clang/duchain/unknowndeclarationproblem.cpp:120
#7 0x00007fff67538cd7 in (anonymous namespace)::includeFiles (identifier=..., file=..., range=...) at /home/blackjack/projects/other/kdev-clang/duchain/unknowndeclarationproblem.cpp:407
#8 0x00007fff67539137 in (anonymous namespace)::fixUnknownDeclaration (identifier=..., file=..., docrange=...) at /home/blackjack/projects/other/kdev-clang/duchain/unknowndeclarationproblem.cpp:443
#9 0x00007fff6753973e in UnknownDeclarationProblem::solutionAssistant (this=0x7fffb4b393f0) at /home/blackjack/projects/other/kdev-clang/duchain/unknowndeclarationproblem.cpp:497
#10 0x00007ffff2f977b1 in KDevelop::StaticAssistantsManager::Private::checkAssistantForProblems (this=0x1e1e480, top=0x3243b90) at /home/blackjack/projects/other/kdevplatform/language/assistant/staticassistantsmanager.cpp:285
#11 0x00007ffff2f973a5 in KDevelop::StaticAssistantsManager::Private::parseJobFinished (this=0x1e1e480, job=0xe2d1a0) at /home/blackjack/projects/other/kdevplatform/language/assistant/staticassistantsmanager.cpp:246
#12 0x00007ffff2f9994a in KDevelop::StaticAssistantsManager::Private::Private(KDevelop::StaticAssistantsManager*)::{lambda(KDevelop::ParseJob*)#1}::operator()(KDevelop::ParseJob*) const () at /home/blackjack/projects/other/kdevplatform/language/assistant/staticassistantsmanager.cpp:52
#13 0x00007ffff2f9cba2 in QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<KDevelop::ParseJob*>, void, KDevelop::StaticAssistantsManager::Private::Private(KDevelop::StaticAssistantsManager*)::{lambda(KDevelop::ParseJob*)#1}>::call({lambda(KDevelop::ParseJob*)#1}, void**) (f=..., arg=0x7fffffffd3c0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:494
#14 0x00007ffff2f9c8f2 in QtPrivate::Functor<KDevelop::StaticAssistantsManager::Private::Private(KDevelop::StaticAssistantsManager*)::{lambda(KDevelop::ParseJob*)#1}, 1>::call<QtPrivate::List<KDevelop::ParseJob*>, void>({lambda(KDevelop::ParseJob*)#1}&, void*, {lambda(KDevelop::ParseJob*)#1}&*) (f=..., arg=0x7fffffffd3c0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:551
#15 0x00007ffff2f9c225 in QtPrivate::QFunctorSlotObject<KDevelop::StaticAssistantsManager::Private::Private(KDevelop::StaticAssistantsManager*)::{lambda(KDevelop::ParseJob*)#1}, 1, QtPrivate::List<KDevelop::ParseJob*>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (which=1, this_=0x1e1e500, r=0x1dd8260, a=0x7fffffffd3c0, ret=0x0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobject_impl.h:192
#16 0x00007ffff55669fa in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007ffff3176680 in KDevelop::BackgroundParser::parseJobFinished (this=0x1134c20, _t1=0xe2d1a0) at /home/blackjack/projects/other/build/kdevplatform/language/moc_backgroundparser.cpp:403
#18 0x00007ffff2fb4a09 in KDevelop::BackgroundParser::parseComplete (this=0x1134c20, job=...) at /home/blackjack/projects/other/kdevplatform/language/backgroundparser/backgroundparser.cpp:605
#19 0x00007ffff2fc151f in QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<QSharedPointer<ThreadWeaver::JobInterface> >, void, void (KDevelop::BackgroundParser::*)(QSharedPointer<ThreadWeaver::JobInterface> const&)>::call (f=(void (KDevelop::BackgroundParser::*)(KDevelop::BackgroundParser * const, const QSharedPointer<ThreadWeaver::JobInterface> &)) 0x7ffff2fb48fa <KDevelop::BackgroundParser::parseComplete(QSharedPointer<ThreadWeaver::JobInterface> const&)>, o=0x1134c20, arg=0x7fffb4afd3f0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:500
#20 0x00007ffff2fc09f4 in QtPrivate::FunctionPointer<void (KDevelop::BackgroundParser::*)(QSharedPointer<ThreadWeaver::JobInterface> const&)>::call<QtPrivate::List<QSharedPointer<ThreadWeaver::JobInterface> >, void> (f=(void (KDevelop::BackgroundParser::*)(KDevelop::BackgroundParser * const, const QSharedPointer<ThreadWeaver::JobInterface> &)) 0x7ffff2fb48fa <KDevelop::BackgroundParser::parseComplete(QSharedPointer<ThreadWeaver::JobInterface> const&)>, o=0x1134c20, arg=0x7fffb4afd3f0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:519
#21 0x00007ffff2fbf1c7 in QtPrivate::QSlotObject<void (KDevelop::BackgroundParser::*)(QSharedPointer<ThreadWeaver::JobInterface> const&), QtPrivate::List<QSharedPointer<ThreadWeaver::JobInterface> >, void>::impl (which=1, this_=0xe02410, r=0x1134c20, a=0x7fffb4afd3f0, ret=0x0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobject_impl.h:143
#22 0x00007ffff5567dca in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007ffff5e41adc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#24 0x00007ffff5e46fb0 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#25 0x00007ffff55362eb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007ffff553835b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x00007ffff558eeb3 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#28 0x00007fffedb58cfd in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fffedb58fe0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fffedb5908c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007ffff558f2c7 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#32 0x00007ffff5533aa2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#33 0x00007ffff553b6ec in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#34 0x0000000000418656 in main (argc=3, argv=0x7fffffffdef8) at /home/blackjack/projects/other/kdevelop/app/main.cpp:618


auto is deduced not to QString but to QStringBuilder instead, that holds a reference to some temporary data. When you explicitly cast it to QString the error goes away.

Comment 3 Oleksandr Senkovych 2015-07-28 10:22:34 UTC

Created attachment 93774 [details]
Updated patch

Updated patch - similar issue in another place

Comment 4 Kevin Funk 2015-07-28 11:07:12 UTC

Git commit cb348e381c6d3dc97c2436ed10bd9d4588d3bc92 by Kevin Funk, on behalf of Oleksandr Senkovych.
Committed on 28/07/2015 at 11:06.
Pushed by kfunk into branch 'master'.

Fix crash when auto is deduced to QStringBuilder

In this case 'auto' is deduced to QStringBuilder instead of QString (b/c
of QT_FAST_OPERATOR_PLUS we've just enabled). QStringBuilder holds
temporary data which is accessed when this object is finally converted
to a proper QString later on. => Crash

M  +2    -2    duchain/unknowndeclarationproblem.cpp

http://commits.kde.org/kdev-clang/cb348e381c6d3dc97c2436ed10bd9d4588d3bc92

Comment 5 Kevin Funk 2015-07-28 11:08:04 UTC

Pushed.

Note: Please use 'git format-patch' next time, so the author information is stored inside the patch => Makes my job easier.

Thanks again!