[fpc-pascal] Clueless here

[Michalis Kamburelis]

Darius Blaszijk wrote:
> Hi,
>  
> I have two overloaded functions. One overloaded function just rearanges
> one parameter from an array of extended to an array of ^extended and
> calls the other overloaded function. The problem is however that the 2nd
> function call crashes the app. I really have no idea why therefore I'm
> posting the code in the hope someone with more insight can help me here.
>  
> So what happens is the following; the first debugmessages are ok and as
> expected. However the second debugmessages (array of PJmFloat) crash the
> application. I have attached the backtrace.
>  
> Darius
>  
> type
>   TJmFloat = extended;
>   PJmFloat = ^TJmFloat;
>   TDynTJmFloatArray = array of TJmFloat;
>  
> Function FitSession( Parameters : array of PJmFloat; ChiSquareFunc :
> TOFitFunc ) : IFit;
> var i: integer;
> begin
>   //debug only
>   for i := 0 to High(Parameters) do
>     ShowMessage('array of PJmFloat ' + FloatToStr(Parameters[i]^));
>  
>  Result := TFit.Create( Parameters, ChiSquareFunc );
> end;
>  
> function FitSession(Parameters: TDynTJmFloatArray; ChiSquareFunc:
> TOFitFunc): IFit;
> var
>   Params: array of PJmFloat;
>   i: integer;
> begin
>   SetLength(Params, Length(Parameters));
>  
>   for i := 0 to High(Parameters) do
>   begin
>     Params[i] := AllocMem(SizeOf(TJmFloat));
>     Params[i] := @Parameters[i];

Don't you want to write here
  Params[i]^ := Parameters[i];
?

>   end;
>  
>   //debug only
>   for i := 0 to High(Params) do
>     ShowMessage('TDynTJmFloatArray ' + FloatToStr(Params[i]^));
>  
>   Result := FitSession(Params, ChiSquareFunc);
> end;
> begin
>     SetLength(c, 2);
>     c[0] := 2;
>     c[1] := 0.2;
>     Fit := FitSession(c, @ChiSquareFunc);
> end;
> 
>