SIGSEGV during disassembly in model

[GitMensch]

Happens on "Disassemble" of a specific function in the trace.
Several other functions can be the target of Disassemble without any problems.

hotspot/src/models/highlightedtext.cpp

Lines 353 to 357 in 71a3ca8

	QTextLine HighlightedText::lineAt(int index) const
	{
	auto& line = m_highlightedLines[index];
	return line.layout()->lineAt(0);
	}

retried with current AppImage - same result.

Thread 1 "hotspot" received signal SIGSEGV, Segmentation fault.
HighlightedText::lineAt (this=0x99cc30, index=46) at /github/workspace/src/models/highlightedtext.cpp:356

(gdb) p line
$1 = (const HighlightedLine &) <error reading variable>
(gdb) p m_highlightedLines[index]
Cannot access memory at address 0x5c0
(gdb) p m_highlightedLines
$2 = std::vector of length 0, capacity 0

(gdb) up
#1   0x000000000051d29c in SourceCodeModel::data (this=0x99cc10, index=..., role=260) at /github/workspace/src/models/sourcecodemodel.cpp:173
(gdb) p m_highlightedText
$3 = {<QObject> = {<No data fields>}, static staticMetaObject = {d = {superdata = {direct = 0x7f75db3ab760 <QObject::staticMetaObject>}, stringdata = 0x579b80, data = 0x579ac0, static_metacall = 0x4e4130 <HighlightedText::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, m_repository = 0x987820, m_highlighter = std::unique_ptr<HighlightingImplementation> = {get() = 0xcab4c0}, m_highlightedLines = std::vector of length 0, capacity 0, m_lines = {<QList<QString>> = {<QListSpecialMethods<QString>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, static is_always_lock_free = true}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7f75db1c90c0 <QListData::shared_null>}, d = 0x7f75db1c90c0 <QListData::shared_null>}}, <No data fields>}, m_cleanedLines = {<QList<QString>> = {<QListSpecialMethods<QString>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, static is_always_lock_free = true}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x1105b30}, d = 0x1105b30}}, <No data fields>}, m_isUsingAnsi = false, m_tabWidth = 4}

(gdb) p m_highlightedText.textAt(46).d
$4 = (QString::Data *) 0x11092f0
(gdb) p m_highlightedText.textAt(46).d->size
$5 = 0

(gdb) bt 13
#0  HighlightedText::lineAt (this=0x99cc30, index=46) at /github/workspace/src/models/highlightedtext.cpp:356
#1  0x000000000051d29c in SourceCodeModel::data (this=0x99cc10, index=..., role=260) at /github/workspace/src/models/sourcecodemodel.cpp:173
#2  0x00000000004fa251 in QModelIndex::data (arole=<optimized out>, this=0x7ffeaa07d8b0) at /usr/include/QtCore/qabstractitemmodel.h:460
#3  CodeDelegate::paint (this=0xa20500, painter=0x7ffeaa07dbf8, option=..., index=...) at /github/workspace/src/models/codedelegate.cpp:71
#4  0x00007f75dc228118 in QTreeView::drawRow(QPainter*, QStyleOptionViewItem const&, QModelIndex const&) const () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
#5  0x00007f75dc22bfd5 in QTreeView::drawTree(QPainter*, QRegion const&) const () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
#6  0x00007f75dc232128 in QTreeView::paintEvent(QPaintEvent*) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
#7  0x00007f75dbfa981e in QWidget::event(QEvent*) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
#8  0x00007f75dc052d2e in QFrame::event(QEvent*) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
#9  0x00007f75db0b91f2 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Core.so.5
#10 0x00007f75dbf6aa4e in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
#11 0x00007f75db0b947a in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Core.so.5
#12 0x00007f75dbfa2446 in QWidgetPrivate::sendPaintEvent(QRegion const&) () from /tmp/hotspot-v1.5.1-41/usr/lib/libQt5Widgets.so.5
(More stack frames follow...)

Several other functions can be the target of Dissassemle

[milianw]

can you create an MWE, i.e. provide a cmake project we can profile and disassemble to trigger it? since you lack the Qt pretty printers, what is m_highlightedLines.size()?

and/or can you try to reproduce this with a debug build with assertions enabled?

[GitMensch]

Sadly an MWE will be very complicated, if you can provide me with that debug build, then I can retest (so far I took the appimage + its debuginfos).

(gdb) p m_highlightedLines
$2 = std::vector of length 0, capacity 0

so your question should be answered with "size == 0", no?

[milianw]

please try a newer appimage, maybe my commit ebdeab1 fixes this

[milianw]

closing as assumed-fixed. if not, please reopen