[fpc-pascal]runtime 201 with swapword function

[Marco van de Voort]

> On Fri, Jul 25, 2003 at 04:21:36PM +0200, Jonas Maebe wrote:
> > 
> > On vrijdag, jul 25, 2003, at 16:22 Europe/Brussels, James Mills wrote:
> > 
> > >Why does the following result in a runtime error ?
> > >
> > >program example;
> > >
> > >const
> > >	THE_PORT = 9999;
> > >
> > >function swapWord(w: Word): Word;
> > >begin
> > >	swapWord := (w SHL 8) OR (w SHR 8);
> > >end;
> > 
> > In Pascal, all calculations are performed using the base type (which is 
> > longint in FPC), so if w > 255, then w shl 8 > high(word) and will 
> > result in a range check error when assigning to swapWord. Even if we 
> > calculated everything using words, you'd still get an overflow error, 
> > this time when doing the shl.

change to
  swapword word (w shl 8) OR word (w shr 8);

or temporarily disable {$R+} there.

> 
> How can I correct this ?
> This bit of code was taken directly from server.pp in one of the old
> 2002 mailing threads...

But was it under {$R+} there?