[fpc-devel] Class field reordering

Martin Schreiber mse00000 at gmail.com
Sat Jul 14 08:00:03 CEST 2012

On Saturday 14 July 2012 07:50:58 Martin Schreiber wrote:
> On Saturday 14 July 2012 01:44:39 Jonas Maebe wrote:
> > Hi,
> >
> > I've implemented an optimization that reorders the instance fields of
> > Delphi-style classes (and only of Delphi-style classes) to minimise
> > memory gaps caused by alignment differences and odd sizes. The effect
> > is the same as when you would change the order of the fields in the
> > source code to achieve this effect.
> I sometimes need "cracker" classes in MSEide and MSEgui to fix bugs and
> make extensinsions for FCL classes in order to access private fields
> (examples TDataset, TParam, TField, TFiler, TReader, TWriter, TComponent).
> Is it guaranteed that the local definitions have the same layout as the
> definition in the FCL unit?
Hmm, up to now I listed in the cracker classes fields up to the last private 
field I need to access so the cracker classes would not brake by changing or 
adding successive fields in the original classes. I assume now it is 
necessary to always list all fields of the original class.


More information about the fpc-devel mailing list