Overflow in implicit constant conversion_(re)

Sun, 14 Sep 1997 19:52:24 +0200 (MEST)

According to Robert Ketzscher:
> 
> first of all I hope this is the right address to pose my
> problem.

It is.  Welcome to the GNU Pascal mailing list!

> I get the message
> Overflow in implicit constant conversion
> at the end of the interface part (i.e. where implementation starts).
> I only use a handful constants and even after I commented them out
> I got the same message. I wrote a small unit typedefs as follows:
> 
> unit typedefs;
> 
> interface
> 
> type longint  = __long__ Integer;
>      byte     = __byte__ Integer;
>      extended = __long__ Real;
>      word     = __short__ Integer;
>    longstring = String[255];
>    shortint   =  __byte__ Integer;
> 
> implementation
>    
> begin
> end.

Is this the unit which causes problems?  It compiles well with
all versions of GPC I have at hand.  Which version do you use?

If not, I only can guess that your problems come from initialized
`Byte' variables (typed constants) initialized with values above
127 because you define `Byte' as a signed type.  To get an
unsigned `Byte', use

    Type
      ByteInt = __byte__ Integer;
      Byte = __unsigned__ ByteInt;

If you have more problems and you are using gpc-2.0 or earlier,
you should upgrade to a more recent beta version of GPC, available
at ftp://agnes.dida.physik.uni-essen.de/gnu-pasal/beta/.  The
latest official beta release is gpc-970714; the next one is in
preparation.  This new GPC has the following types - and more -
built in:

    Type
      LongInt   = __long__ Integer;      (* 64 bits *)
      ShortInt  = __short__ Integer;     (* 16 bits; `Integer' has 32 *)
      ByteInt   = __byte__ Integer;      (* 8 bits *)
      LongWord  = __unsigned__ LongInt;  (* 64 bits, unsigned *)
      Word      = __unsigned__ Integer;  (* 32 bits, unsigned *)
      ShortWord = __unsigned__ ShortInt; (* 16 bits, unsigned *)
      Byte      = __unsigned__ ByteInt;  (* 8 bits, unsigned *)
      Extended  = __long__ Real;         (* 80 bits *)

Hope this helps,

    Peter

 Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer
peter.gerwinski@uni-essen.de - http://home.pages.de/~peter.gerwinski/ [970201]
 maintainer GNU Pascal [970714] - http://home.pages.de/~gnu-pascal/ [970125]

Peter Gerwinski (peter@agnes.dida.physik.uni-essen.de)