[vtkusers] Trouble using vtkAxis->SetTitle

[Frese Daniel Dr.]

Hi Marcus,

I simplified as much as I could. Here is the crashing
program :

#include "vtkAxis.h"
#include <string>

void main() {
	std::string temp = "TestX";

	vtkAxis *Xaxis = vtkAxis::New();
	Xaxis->SetTitle(temp.c_str());
}

It crashes at the same line in vtkAxis.cxx as I wrote before.

Testing a bit further, I noted that the program crashes only when built and
run in Debug configuration, but it runs fine in Release. I am aware that in the
Visual Studio Debug and Release versions can behave differently, but in my experience
so far the Debug configuration was always more benign than the Release. So I had a few
times the case that the Release version crashes while the Debug ran fine;
but this time it's the other way around ?!

The only lib I link for this test program is vtkAxis (although the behavior does not
change when linking also other vtk libs additionally). I use in both cases (Debug and
Release) the same vtkAxis.dll (built with the same compiler MSVC 2008 in "RelWithDebInfo" Config).
Is this OK or do I have to built a second set of Debug libs for use in programs built
in the Debug config ? Maybe this whole thing has nothing to do with vtkAxis, but is just a
MSVC thing. On the other hand I've been working with vtk for a few months now and never built any
Debug version of the lib, and is has been working fine so far...

If anybody could shine some light on this, this would be great. I can also post/send a ZIP of the
MSVC solution, but since this is about 400kB, I'd rather not "pollute" the whole mailing list with
such an attachment. The program above is basically the main.cpp of a Win32 console application
without any further whistles and bells.

Daniel

-----Ursprüngliche Nachricht-----
Von: Marcus D. Hanwell [mailto:marcus.hanwell at kitware.com] 
Gesendet: Dienstag, 3. Mai 2011 16:31
An: Frese Daniel Dr.
Cc: vtkusers at vtk.org
Betreff: Re: [vtkusers] Trouble using vtkAxis->SetTitle

2011/5/3 Frese Daniel Dr. <frese at heidenhain.de>:
> Hi !
>
> I am having some strange problem using vtkAxis->SetTitle() from the new
> charts API.
> After the second of the following lines an exception occurs:
>
>                 temp = XAxisName->c_str();
>                 Xaxis->SetTitle(temp);  // title of axis

What is XAxisName, and std::string? There is no need for the temp, but
you could use it (vtkStdString can be constructed in the function from
a const char* that is properly null terminated).
>
> Temp is of type vtkStdString and Xaxis of type vtkSmartPointer<vtkAxis>
> (although the behavior is essentially the same when I make Xaxis as a direct
> vtkAxis without any smart pointers).
> I checked that the value of temp at this point is well defined ("TestX"),
> and I can trace further until I arrive at
> void vtkAxis::SetTitle(const vtkStdString &title)
> {
>   if (this->Title != title)
>     {
>     this->Title = title;
>     this->Modified();
>     }
> }
>
> , which is defined in vtkAxis.cxx. The exception occurs when trying to
> execute the line this->Title = title;
> The odd thing - already indicating that something goes wrong - is that
> "title" seems to point four bytes before the right string and seems to be
> much longer; i.e. it shows XXXXTestXXXXXX., where X is some arbitrary
> garbage byte.
>
> I am using Visual Studio 2008 on Win XP and get an exception message stating
> some memory corruption.
>
> Does anybody has a clue what's going on here ? If I remove calls to SetTitle
> (I have two of them in my app), everything seems to run smoothly (apart from
> the missing labels of course).
>
I have not seen this, if you can create a minimal test case that
reproduces the error I could take a look. Maybe our Windows developers
have a better idea, but the VTK tests run regularly on Windows and set
the axis title using a const char *, which then uses the const char *
constructor to make a temporary vtkStdString.

Marcus

-------------- next part --------------
-------------------------------------------------------------------------------------------------------
Registergericht: Traunstein / Registry Court: HRB 275 ? Sitz / Head Office: Traunreut
Aufsichtsratsvorsitzender / Chairman of Supervisory Board: Rainer Burkhard
Geschäftsführung / Management Board: Thomas Sesselmann (Vorsitzender / Chairman),
Michael Grimm, Matthias Fauser, Sebastian Tondorf

E-Mail Haftungsausschluss / E-Mail Disclaimer: http://www.heidenhain.de/disclaimer