[Lazarus] How well should Lazarus check method parameters?

[Mattias Gaertner]

On Thu, 23 Feb 2012 07:07:47 +0000
Mark Morgan Lloyd <markMLl.lazarus at telemetry.co.uk> wrote:

> Mattias Gaertner wrote:
> > On Wed, 22 Feb 2012 20:55:01 +0000
> > Mark Morgan Lloyd <markMLl.lazarus at telemetry.co.uk> wrote:
> > 
> >> I've just spotted this in my code:
> >>
> >> procedure FormCloseQuery(Sender: TObject; CanClose: boolean);
> >> ..
> >> procedure TListForm.FormCloseQuery(Sender: TObject; CanClose: Boolean);
> >>
> >> Those were inserted by some old version of the IDE, presumably the 
> >> current version inserts the missing var.
> > 
> > I don't remember such a bug, but I'm not sure. Maybe it was there for a
> > very short time and you were just unlucky.
> 
> Only thing there is that I roughed that program out a long time before I 
> was getting Lazarus from svn, so it might in fact be in one or more 
> releases. Appears to be OK at 0.9.24.1, so it's fairly unlikely that 
> anybody's still using an affected copy.
> 
> >> Shouldn't either the IDE or the runtimes pick up this error?
> > 
> > It's valid code. What do you expect?
> 
> I'd expect the trunk IDE or runtimes to realise that the second 
> parameter isn't compatible with the current definitions.

Ah, now I see what you mean:

TCloseQueryEvent = procedure(Sender : TObject; var CanClose : boolean) of object;

And you have

procedure TListForm.FormCloseQuery(Sender: TObject; CanClose: Boolean);

Yes, the IDE adds the var when the event is created. I don't know when
this was implemented - a long time ago.
There is currently no tool to fix the signatures.
The LFM / TReader does not check either.

You can create feature requests if you like.

Mattias