[Fixed] Crash when typing expressions

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DeepSOIC
Posts: 7832
Joined: Fri Aug 29, 2014 12:45 am
Location: Saint-Petersburg, Russia

[Fixed] Crash when typing expressions

Postby DeepSOIC » Sat Aug 24, 2019 1:02 pm

1. Open attached file.
link-part-multinesting.FCStd
(14.74 KiB) Downloaded 21 times
2. Locate "Link (to Part)" object (in Part001).
3. expand Placement property, click f(x) on angle value.
4. type "Sketch.Placement.Angle"
The moment I type letter "g", FreeCAD closes itself. Before typing "g", I see an error message "Illegal storage access" something something.

It may have been fixed in this PR, as there are some changes to expression parser and autocompleter.
https://github.com/FreeCAD/FreeCAD/pull/2449
But I haven't tested.

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17803 (Git)
Build type: Release
Branch: master
Hash: 89961a33d46063a43e9fb5b0308ca95d559eca94
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Russian/Russia (ru_RU)
Last edited by DeepSOIC on Thu Aug 29, 2019 12:18 am, edited 2 times in total.
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user1234
Posts: 344
Joined: Mon Jul 11, 2016 5:08 pm

Re: Crash when typing epressions

Postby user1234 » Sat Aug 24, 2019 5:28 pm

Hello!

Yes, crashes after i type "Sketch.Placement.A":

Code: Select all

OS: Debian GNU/Linux 10 (buster) (X-Cinnamon/lightdm-xsession)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17903 (Git)
Build type: DebWithRelInfo
Branch: LinkMerge
Hash: c4850ab220000e96733fa98e86720c354b05a6d0
Python version: 3.7.3
Qt version: 5.11.3
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)
_expression_crash.webm
(736.19 KiB) Downloaded 15 times

Code: Select all

Program received signal SIGSEGV, Segmentation fault.
#0  /lib/x86_64-linux-gnu/libc.so.6(+0x37840) [0x7f6340c58840]
#1  0x7f6344cca432 in App::ObjectIdentifier::Component::get(Py::Object const&) const from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADApp.so+0x482
#2  0x7f6344cd0777 in App::ObjectIdentifier::access(App::ObjectIdentifier::ResolveResults const&, Py::Object*) const from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADApp.so+0x126f
#3  0x7f6344cd0d62 in App::ObjectIdentifier::getValue(bool, bool*) const from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADApp.so+0x194
#4  0x7f6344cd6644 in App::Property::getPathValue(App::ObjectIdentifier const&) const from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADApp.so+0x2e
#5  0x7f6344cf3c17 in App::PropertyPlacement::getPathValue(App::ObjectIdentifier const&) const from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADApp.so+0x1cd
#6  0x7f6344c3505c in App::VariableExpression::eval() const from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADApp.so+0xd6
#7  0x7f6346097f03 in Gui::Dialog::DlgExpressionInput::textChanged(QString const&) from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADGui.so+0x28d
#8  /home/pc/Programs/FreeCAD_Link/lib/libFreeCADGui.so(+0xffa718) [0x7f6346098718]
#9  0x7f6341601906 in QMetaObject::activate(QObject*, int, int, void**) from /lib/x86_64-linux-gnu/libQt5Core.so.5+0x766
#10  0x7f6342088d52 in QLineEdit::textChanged(QString const&) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x32
#11  /lib/x86_64-linux-gnu/libQt5Widgets.so.5(+0x299609) [0x7f634208f609]
#12  0x7f6341601906 in QMetaObject::activate(QObject*, int, int, void**) from /lib/x86_64-linux-gnu/libQt5Core.so.5+0x766
#13  0x7f6342090165 in QWidgetLineControl::textChanged(QString const&) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x35
#14  0x7f63420934ce in QWidgetLineControl::finishChange(int, bool, bool) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x28e
#15  0x7f634209677e in QWidgetLineControl::processKeyEvent(QKeyEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0xe6e
#16  0x7f6342088eaa in QLineEdit::keyPressEvent(QKeyEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x1a
#17  0x7f6345fabce8 in Gui::ExpressionLineEdit::keyPressEvent(QKeyEvent*) from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADGui.so+0x40
#18  0x7f6341f93ba7 in QWidget::event(QEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x7f7
#19  0x7f634208eeba in QLineEdit::event(QEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0xaa
#20  0x7f6341f554b1 in QApplicationPrivate::notify_helper(QObject*, QEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x81
#21  0x7f6341f5d8b1 in QApplication::notify(QObject*, QEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x1171
#22  0x7f6345fb070d in Gui::GUIApplication::notify(QObject*, QEvent*) from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADGui.so+0xff
#23  0x7f63415d85a9 in QCoreApplication::notifyInternal2(QObject*, QEvent*) from /lib/x86_64-linux-gnu/libQt5Core.so.5+0x179
#24  /lib/x86_64-linux-gnu/libQt5Widgets.so.5(+0x1bab89) [0x7f6341fb0b89]
#25  0x7f6341f554b1 in QApplicationPrivate::notify_helper(QObject*, QEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x81
#26  0x7f6341f5c950 in QApplication::notify(QObject*, QEvent*) from /lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x210
#27  0x7f6345fb070d in Gui::GUIApplication::notify(QObject*, QEvent*) from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADGui.so+0xff
#28  0x7f63415d85a9 in QCoreApplication::notifyInternal2(QObject*, QEvent*) from /lib/x86_64-linux-gnu/libQt5Core.so.5+0x179
#29  0x7f6341982578 in QGuiApplicationPrivate::processKeyEvent(QWindowSystemInterfacePrivate::KeyEvent*) from /lib/x86_64-linux-gnu/libQt5Gui.so.5+0x168
#30  0x7f6341987e05 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) from /lib/x86_64-linux-gnu/libQt5Gui.so.5+0x115
#31  0x7f634196206b in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) from /lib/x86_64-linux-gnu/libQt5Gui.so.5+0xab
#32  /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5(+0xdd3eb) [0x7f633bb1a3eb]
#33  0x7f63415d727b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) from /lib/x86_64-linux-gnu/libQt5Core.so.5+0x13b
#34  0x7f63415df262 in QCoreApplication::exec() from /lib/x86_64-linux-gnu/libQt5Core.so.5+0x92
#35  0x7f6345e9ccab in Gui::Application::runApplication() from /home/pc/Programs/FreeCAD_Link/lib/libFreeCADGui.so+0x228f
#36  ./FreeCAD(main+0xae7) [0x555e349ab0d6]
#37  /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xeb) [0x7f6340c4509b]
#38  ./FreeCAD(_start+0x2a) [0x555e349aa4ba]
But i have seen more bugs and crashes in the expressions. I will report them soon.

Greetings
user
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realthunder
Posts: 1847
Joined: Tue Jan 03, 2017 10:55 am

Re: Crash when typing epressions

Postby realthunder » Sun Aug 25, 2019 10:51 am

user1234 wrote: ↑
Sat Aug 24, 2019 5:28 pm
 Hello!

Yes, crashes after i type "Sketch.Placement.A":
Are you experiencing the crash after sync with my branch? Hmm... I can't reproduce it. Maybe Python3 related? Seems unlikely. I'll get a Python3 build and see.
Try Assembly3 (latest version 0.11) along with my custom build of FreeCAD at here.
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paullee
Posts: 2983
Joined: Wed May 04, 2016 3:58 pm

Re: Crash when typing epressions

Postby paullee » Sun Aug 25, 2019 11:17 am

Something similar ?

FreeCAD_0.19-17798-Linux-Conda_Py3Qt5_glibc2.12-x86_64.AppImage
on
Fedora

Inputting in Rotation expression something like Sketch.Placement.a .... FC crashes

Haven't tried to retry and record reproducible steps then I see this thread. Same problem?
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realthunder
Posts: 1847
Joined: Tue Jan 03, 2017 10:55 am

Re: Crash when typing epressions

Postby realthunder » Sun Aug 25, 2019 1:50 pm

Yes, I can reproduce this with Python3. Looks like something "not so right" with PyCXX for Python3, calling getAttr() without checking hasAttr() cause crash in Python3, but not Python2. I would expect an exception. Anyway, I've already pushed a fix.
Try Assembly3 (latest version 0.11) along with my custom build of FreeCAD at here.
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User avatar
DeepSOIC
Posts: 7832
Joined: Fri Aug 29, 2014 12:45 am
Location: Saint-Petersburg, Russia

Re: Crash when typing epressions

Postby DeepSOIC » Sun Aug 25, 2019 1:54 pm

realthunder wrote: ↑
Sun Aug 25, 2019 1:50 pm
 Looks like something "not so right" with PyCXX for Python3, calling getAttr() without checking hasAttr() cause crash in Python3, but not Python2. I would expect an exception.

Code: Select all

>>> getattr(App.ActiveDocument.Box.Placement, 'Ang')
Traceback (most recent call last):
  File "<input>", line 1, in <module>
AttributeError: 'Base.Placement' object has no attribute 'Ang'
>>>
:|
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17803 (Git)
Build type: Release
Branch: master
Hash: 89961a33d46063a43e9fb5b0308ca95d559eca94
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Russian/Russia (ru_RU)
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User avatar
DeepSOIC
Posts: 7832
Joined: Fri Aug 29, 2014 12:45 am
Location: Saint-Petersburg, Russia

Re: Crash when typing epressions

Postby DeepSOIC » Sun Aug 25, 2019 1:58 pm

realthunder wrote: ↑
Sun Aug 25, 2019 1:50 pm
 calling getAttr() without checking hasAttr() cause crash
Especially strange considering python's hasattr is actualy implemented by trying getattr and returning false if AttributeError is raied.
https://gist.github.com/taozle/f3b3d903 ... 8ea89c66b7

Code: Select all

static PyObject *
builtin_hasattr_impl(PyObject *module, PyObject *obj, PyObject *name)
{
    PyObject *v;

    if (!PyUnicode_Check(name)) {
        PyErr_SetString(PyExc_TypeError,
                        "hasattr(): attribute name must be string");
        return NULL;
    }
    v = PyObject_GetAttr(obj, name);
    if (v == NULL) {
        if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
            PyErr_Clear();
            Py_RETURN_FALSE;
        }
        return NULL;
    }
    Py_DECREF(v);
    Py_RETURN_TRUE;
}
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realthunder
Posts: 1847
Joined: Tue Jan 03, 2017 10:55 am

Re: Crash when typing epressions

Postby realthunder » Sun Aug 25, 2019 10:32 pm

DeepSOIC wrote: ↑
Sun Aug 25, 2019 1:58 pm
 Especially strange considering python's hasattr is actualy implemented by trying getattr and returning false if AttributeError is raied.
What I meant is PyCXX, the C++ wrapper FC is using for Python, the Py::Object stuff. I check the code, it seems Python2 and Python3 wrapper code for getAttr part is identical. A debug build will catch the actual location of the crash quit easily, which I didn't do. I am still a bit reluctant to upgrade my ubuntu.
Try Assembly3 (latest version 0.11) along with my custom build of FreeCAD at here.
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TheMarkster
Posts: 2059
Joined: Thu Apr 05, 2018 1:53 am

Re: Crash when typing epressions

Postby TheMarkster » Sun Aug 25, 2019 11:31 pm

This is the call stack from a debug build on vs2017

Code: Select all

>	FreeCADApp_d.dll!App::ObjectIdentifier::Component::get(const Py::Object & pyobj) Line 621	C++
 	FreeCADApp_d.dll!App::ObjectIdentifier::access(const App::ObjectIdentifier::ResolveResults & result, Py::Object * value) Line 1634	C++
 	FreeCADApp_d.dll!App::ObjectIdentifier::getValue(bool pathValue, bool * isPseudoProperty) Line 1675	C++
 	FreeCADApp_d.dll!App::Property::getPathValue(const App::ObjectIdentifier & path) Line 128	C++
 	FreeCADApp_d.dll!App::PropertyPlacement::getPathValue(const App::ObjectIdentifier & path) Line 668	C++
 	FreeCADApp_d.dll!App::VariableExpression::eval() Line 2096	C++
 	FreeCADGui_d.dll!Gui::Dialog::DlgExpressionInput::textChanged(const QString & text) Line 136	C++
 	FreeCADGui_d.dll!Gui::Dialog::DlgExpressionInput::qt_static_metacall(QObject * _o, QMetaObject::Call _c, int _id, void * * _a) Line 76	C++

Code: Select all

Py::Object ObjectIdentifier::Component::get(const Py::Object &pyobj) const {
    Py::Object res;
    if(isSimple()) {
        res = pyobj.getAttr(getName());
    } else if(isArray()) {
        if(pyobj.isMapping())
            res = Py::Mapping(pyobj).getItem(Py::Int(begin));
        else
            res = Py::Sequence(pyobj).getItem(begin);
    }else if(isMap())
        res = Py::Mapping(pyobj).getItem(getName());
    else {
        assert(isRange());
        Py::Object slice(PySlice_New(Py::Int(begin).ptr(),
                                    end!=INT_MAX?Py::Int(end).ptr():0,
                                    step!=1?Py::Int(step).ptr():0));
        PyObject *r = PyObject_GetItem(pyobj.ptr(),slice.ptr());
        if(!r)
            Base::PyException::ThrowException();
        res = Py::asObject(r);
    }
    if(PyModule_Check(res.ptr()) && !ExpressionParser::isModuleImported(res.ptr()))
        FC_THROWM(Base::RuntimeError, "Module '" << getName() << "' access denied."); // --> exception thrown here
    return res;
}
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17887 (Git)
Build type: Debug
Branch: master
Hash: e6e94075518efaad2ccd3a2a3feda9682144c5c7
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
My FreeCAD video series on youtube: https://www.youtube.com/c/mwganson
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realthunder
Posts: 1847
Joined: Tue Jan 03, 2017 10:55 am

Re: Crash when typing epressions

Postby realthunder » Sun Aug 25, 2019 11:42 pm

TheMarkster wrote: ↑
Sun Aug 25, 2019 11:31 pm
 This is the call stack from a debug build on vs2017
Ah, I see the actual crash site. Thanks!
Try Assembly3 (latest version 0.11) along with my custom build of FreeCAD at here.
And if you'd like to show your support, you can donate through patreon, liberapay, or paypal
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