[Qt-interest] Replace Qt Allocator

[David Walthall]

Eric Clark wrote:
> Our program uses a system allocator called nedmalloc. We override the 
> new and delete operators to use this system allocator. However, after 
> porting to Qt 4 we have ran into some issues with the QList class and 
> it’s destructor. When the list is destructed, it attempts to free the 
> memory created by the list, but nedfree() crashes because the memory was 
> instantiated using the system allocator, malloc(). Here is the problem:
> 
> The problem is indeed a violation of the ODR requirement in the ISO C++ 
> spec. For example in this line:
> 
>    QModelIndexList indexes = list->selectionModel()->selectedRows();
> 
> QModelIndexList exists in the local binary due to being a templated type 
> based on QList, therefore its destructor is called from the local binary 
> where ::operator delete has been defined to invoke nedmalloc. 
> Unfortunately the initial constructor of the list (selectedRows()) 
> exists in one of the Qt DLL binaries where ::operator new is defined to 
> invoke the system allocator. Therefore the list is being constructed 
> with the system allocator and destructed with nedmalloc - this obviously 
> enough provokes a segfault as ODR is violated.

Did you take Thiago's advice and recompile Qt to use nedmalloc?

http://lists.trolltech.com/pipermail/qt-interest/2009-June/009114.html


David