[fpc-pascal] FPC can't determine overloaded function to call

[Peter]

On 28/04/16 14:02, Graeme Geldenhuys wrote:
> Hi,
> 
> I can't figure out why FPC is struggling with figuring out which
> overloaded methods to call. This is my application code which FPC has a
> problem with.
> 
> type
>   TPDFFloat = Single;
> 
>   TPDFCoord = record
>     X,Y: TPDFFloat;
>   end;
> 
> var
>   W, H: integer
> begin
>   ...snip...
>   P.DrawImage(25, 190, W div 2, H div 2, IDX);  // this fails
> 
> Yet this works
>   P.DrawImage(25, 190, Integer(W div 2), Integer(H div 2), IDX);
> 
> 
> Here are the overloaded DrawImage() definitions [sorry if you email
> client wraps this badly]:
> 
> { X, Y coordinates are the bottom-left coordinate of the image. AWidth
> and AHeight are in image pixels. }
> Procedure DrawImage(const X, Y: TPDFFloat; const AWidth, AHeight,
> ANumber: integer); overload;
> 
> Procedure DrawImage(const APos: TPDFCoord; const AWidth, AHeight,
> ANumber: integer); overload;
> 
> { X, Y coordinates are the bottom-left coordinate of the image. AWidth
> and AHeight are in UnitOfMeasure units. }
> Procedure DrawImage(const X, Y: TPDFFloat; const AWidth, AHeight:
> TPDFFloat; ANumber: integer); overload;
> 
> Procedure DrawImage(const APos: TPDFCoord; const AWidth, AHeight:
> TPDFFloat; ANumber: integer); overload;
> 
> 
> This is the compiler error message I got:
> ==============================
> Compile Project, Target: testfppdf: Exit code 1, Errors: 1, Hints: 2
> testfppdf.lpr(281,46) Error: Can't determine which overloaded function
> to call
> fppdf.pp(1802,20) Hint: Found declaration: TPDFPage.DrawImage(const
> Single,const Single,const Single,const Single,const LongInt);
> fppdf.pp(1788,20) Hint: Found declaration: TPDFPage.DrawImage(const
> Single,const Single,const LongInt,const LongInt,const LongInt);
> ==============================
> 
> 
> Doesn't the code ⸢(W div 2)⸥ resolve to an Integer result? W is an
> Integer type, and DIV is an integer division.
> 
> I'm using 64-bit FPC 2.6.4.
> 
> Regards,
>   Graeme
> 

Sizeof  'W' is 2
Sizeof '(W div 2)' is 8

I suspect '(W div 2) gives int64.

Regards,
Pete