Qt-interest Archive, December 2006
MSVC 6.0 SP6 crashes on QApplication app(argc, argv);
Message 1 in thread
Hi There,
I have a small (three-four windows) application. It was fine until I added
some more lines (a QWidget::close() somewhere). When I start in debug mode
(setting the breakpoint on int main, the very first line), it is clearly
visible that this line causes a mysterious crash in Visual Studio. It looks
that the debugged application starts to do a huge number (millions) of I/O
Reads as per the Windows task manager. The actual dll which crashes is
tlloc.dll.
I use Qt 4.2.0 commercial on WinXP where this problem occurs. Has anyone
seen this behavior before?
Thanks,
Sandor
Message 2 in thread
Hadas Sandor schrieb:
> I have a small (three-four windows) application. It was fine until I
> added some more lines (a QWidget::close() somewhere). [...]
>
> I use Qt 4.2.0 commercial on WinXP where this problem occurs. Has anyone
> seen this behavior before?
Qt 4.2.2 works fine here with the same VC version. As it obviously isn't
a problem with 4.2.0, perhaps your mentioned changes are responsible for
the crash? Check for dangling pointers, or provide code...
Martin
--
[ signature omitted ]
Message 3 in thread
Hi There,
First line of the code means that all what has been executed are:
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
Nothing else.
No pointers, no anything.
Just the creation of the QApplication instance.
Sandor
-----Original Message-----
From: qt-interest-request@xxxxxxxxxxxxx
[mailto:qt-interest-request@xxxxxxxxxxxxx]On Behalf Of Martin Gebert
Sent: 20/12/2006 14:41
To: qt-interest@xxxxxxxxxxxxx
Subject: Re: MSVC 6.0 SP6 crashes on QApplication app(argc, argv);
Hadas Sandor schrieb:
> I have a small (three-four windows) application. It was fine until I
> added some more lines (a QWidget::close() somewhere). [...]
>
> I use Qt 4.2.0 commercial on WinXP where this problem occurs. Has anyone
> seen this behavior before?
Qt 4.2.2 works fine here with the same VC version. As it obviously isn't
a problem with 4.2.0, perhaps your mentioned changes are responsible for
the crash? Check for dangling pointers, or provide code...
Martin
--
[ signature omitted ]
Message 4 in thread
Hadas Sandor wrote:
>
> Hi There,
>
> First line of the code means that all what has been executed are:
> int main(int argc, char *argv[]) {
> QApplication app(argc, argv);
>
> Nothing else.
> No pointers, no anything.
> Just the creation of the QApplication instance.
>
That might not be true.
Do you have any global objects in your code? Their constructors would be
called before main() AFAIK.
Best,
Andre
--
[ signature omitted ]
Message 5 in thread
Hadas Sandor wrote:
>
> Hi There,
>
> First line of the code means that all what has been executed are:
> int main(int argc, char *argv[]) {
> QApplication app(argc, argv);
>
> Nothing else.
> No pointers, no anything.
> Just the creation of the QApplication instance.
>
I saw a similar thing once and rebuilding the entire solution in VC++
solved the problem.
May not help but it's worth a try.
- Keith
--
[ signature omitted ]
Message 6 in thread
>> > Just the creation of the QApplication instance. <<
If that's the case, you should be able to get it to crash with
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
}
If this doesn't crash, build up until it does crash -- rather than the
other way around.
Might be easier to diagnose if you posted the whole of your main.cpp.
Sam Dutton
SAM DUTTON
SENIOR SITE DEVELOPER
200 GRAY'S INN ROAD
LONDON
WC1X 8XZ
UNITED KINGDOM
T +44 (0)20 7430 4496
F
E SAM.DUTTON@xxxxxxxxx
WWW.ITN.CO.UK
-----Original Message-----
From: Andre Haupt [mailto:haupt.andre@xxxxxx]
Sent: Wednesday 20 December 2006 13:13
To: qt-interest@xxxxxxxxxxxxx
Subject: Re: MSVC 6.0 SP6 crashes on QApplication app(argc, argv);
Hadas Sandor wrote:
>
> Hi There,
>
> First line of the code means that all what has been executed are:
> int main(int argc, char *argv[]) {
> QApplication app(argc, argv);
>
> Nothing else.
> No pointers, no anything.
> Just the creation of the QApplication instance.
>
That might not be true.
Do you have any global objects in your code? Their constructors would be
called before main() AFAIK.
Best,
Andre
--
[ signature omitted ]
Message 7 in thread
Meantime I replaced Qt4.2.0 to Qt4.2.2 and it is still the same.
This is my main.
#include <QApplication>
#include "tenanteditor.h"
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
CTenantEditor widget;
widget.show();
return app.exec();
}
When running step by step in disassembly (I am not sure if that helps), I
see this:
1: #include <QApplication>
2:
3: #include "tenanteditor.h"
4:
5: int main(int argc, char *argv[]) {
004060BB push ebp
004060BC mov ebp,esp
004060BE push 0FFh
004060C0 push offset $L51223 (00412aac)
004060C5 mov eax,fs:[00000000]
004060CB push eax
004060CC mov dword ptr fs:[0],esp
004060D3 sub esp,0C8h
6: QApplication app(argc, argv);
004060D9 push 40202h
004060DE mov eax,dword ptr [argv]
004060E1 push eax
004060E2 lea ecx,[argc]
004060E5 push ecx
004060E6 lea ecx,[app]
004060EC call dword ptr [__imp_??0QApplication@@QAE@AAHPAPADH@Z
(0041ce98)]
004060F2 mov dword ptr [ebp-4],0
Step into on the push after 6: and it hangs immediately followed by the
crash. Hmmm.
Cheers, Sandor
-----Original Message-----
From: qt-interest-request@xxxxxxxxxxxxx
[mailto:qt-interest-request@xxxxxxxxxxxxx]On Behalf Of Dutton, Sam
Sent: 20/12/2006 15:23
To: Andre Haupt; qt-interest@xxxxxxxxxxxxx
Subject: RE: MSVC 6.0 SP6 crashes on QApplication app(argc, argv);
>> > Just the creation of the QApplication instance. <<
If that's the case, you should be able to get it to crash with
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
}
If this doesn't crash, build up until it does crash -- rather than the
other way around.
Might be easier to diagnose if you posted the whole of your main.cpp.
Sam Dutton
SAM DUTTON
SENIOR SITE DEVELOPER
200 GRAY'S INN ROAD
LONDON
WC1X 8XZ
UNITED KINGDOM
T +44 (0)20 7430 4496
F
E SAM.DUTTON@xxxxxxxxx
WWW.ITN.CO.UK
-----Original Message-----
From: Andre Haupt [mailto:haupt.andre@xxxxxx]
Sent: Wednesday 20 December 2006 13:13
To: qt-interest@xxxxxxxxxxxxx
Subject: Re: MSVC 6.0 SP6 crashes on QApplication app(argc, argv);
Hadas Sandor wrote:
>
> Hi There,
>
> First line of the code means that all what has been executed are:
> int main(int argc, char *argv[]) {
> QApplication app(argc, argv);
>
> Nothing else.
> No pointers, no anything.
> Just the creation of the QApplication instance.
>
That might not be true.
Do you have any global objects in your code? Their constructors would be
called before main() AFAIK.
Best,
Andre
--
[ signature omitted ]
Message 8 in thread
Hadas Sandor schrieb:
>
>
> Meantime I replaced Qt4.2.0 to Qt4.2.2 and it is still the same.
Also make sure you're using the latest service pack for MSVC 6 which I
believe is SP5 (or even 6 already?).
Then make sure you have the proper compiler switches, especially the
proper runtime ("Multithreaded DLL").
Cheers, Oliver
--
[ signature omitted ]
Message 9 in thread
Hadas Sandor schrieb:
> Meantime I replaced Qt4.2.0 to Qt4.2.2 and it is still the same.
>
> This is my main.
>
> #include <QApplication>
> #include "tenanteditor.h"
>
> int main(int argc, char *argv[]) {
> QApplication app(argc, argv);
> CTenantEditor widget;
> widget.show();
> return app.exec();
> }
>
> When running step by step in disassembly (I am not sure if that helps),
A stacktrace from after the crash would be more helpful.
However, are you using a .pro file and qmake? If so, is your QTDIR and
PATH set correctly? Might clear things up if you run qmake/read in the
.pro file again. If not do you link against the correct libs (debug if
possible)? If you're not yet using a debug config, now would be the time
to do it...
I simply presume that the contents of argc and argv are valid.
Just raking into the fog here, as remote debugging is a thing still to
be implemented by the newsmaster of this list... ;-)
Martin
--
[ signature omitted ]
Message 10 in thread
On Wednesday 20 December 2006 06:33, Hadas Sandor wrote:
> Meantime I replaced Qt4.2.0 to Qt4.2.2 and it is still the same.
>
> This is my main.
>
> #include <QApplication>
> #include "tenanteditor.h"
>
> int main(int argc, char *argv[]) {
> QApplication app(argc, argv);
> CTenantEditor widget;
> widget.show();
> return app.exec();
> }
Make sure there are no global variables in tenanteditor.h.
--
[ signature omitted ]
