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jackmack
15th December 2010, 14:30
Hi all,

I have a question about detecting memory leaks in my qt based application.

I'm using Qt 4.7.0 with VS2008.

Maybe this is a simple question and I get a fast answer.
This is my snipped out code of my qt based application:

int* a = new int;
*a = 1;

When I start the app in debug-mode within VS2008 and finish the app correctly by clicking the windows system menu then the output window of VS2008 shows only some text like:

...
Thread 'Win32 Thread' (0xf68) finished with code 0 (0x0).
BTMMHOOK 15.12.2010 12:19:31 Thread<0460> Hook DLL unloaded
Thread 'Win32 Thread' (0x132c) finished with code 0 (0x0).
Program "[4052] LineView.exe: Systemown" finished with code 0 (0x0).

When I use the snipped code above in a simple MFC application and run it in debug-mode and close it then the following text is showed by output window of VS2008:

...
BTMMHOOK 15.12.2010 12:21:16 Thread<0E14> Hook DLL unloaded
Detected memory leaks!
Dumping objects ->
e:\entwicklung\simplemfc\simplemfc\simplemfc.cpp(7 7) : {565} normal block at 0x0034B790, 4 bytes long.
Data: < > 01 00 00 00
Object dump complete.
Program "[2160] SimpleMFC.exe: Systemown" finished with code 0 (0x0).

I think that's strange! The compiler warning options are the same.
Yes, I know that all classed inherited by QObject are deleted automatically and "delete" is not neccessary. But the snipped code above causes definitly a memory leak.

Can someone explain that to me why VS2008 doesn't show that messages by developing qt apps?

Thanks a lot,
jack

franz
15th December 2010, 16:39
In visual studio you can enable some memory analysis features (causes your code to become slower). It could be that the memory analysis is automagically enabled to some extent when building an MFC application.

jackmack
15th December 2010, 17:30
In visual studio you can enable some memory analysis features (causes your code to become slower). It could be that the memory analysis is automagically enabled to some extent when building an MFC application.

Where are the analysis features? Then I can check this.

Thanks.