Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!orion.oac.uci.edu!ucivax!milne
From: milne@ics.uci.edu (Alastair Milne)
Newsgroups: comp.lang.pascal
Subject: Re: TP Scope violation bug
Message-ID: <2813B60D.26899@ics.uci.edu>
Date: 23 Apr 91 04:20:29 GMT
References: <7232@oasys.dt.navy.mil>
Distribution: usa
Organization: UC Irvine Department of ICS
Lines: 33

In <7232@oasys.dt.navy.mil> roth@oasys.dt.navy.mil (Pete Roth) writes:

>{
>        The enclosed program shows that Turbo Pascal 6.0 violates
>the scope rules of Pascal by allowing the compilation and incorrect
>execution of the program.  Giving wrong answers, of course.
>        It looks to me like the table of function identifiers is not
>searched when variable identifiers are "compiled."
>}

>PROGRAM aBug ;
>(* demonstrates the violation of scope rules *)
>FUNCTION x : LONGINT ;
>   VAR x : REAL ;
        ^^^^^^^^^^^^^ This is a more local occurrence than the function's
		      name, which belongs to the enclosing scope.
>   BEGIN
>      x := Trunc( 1.0 )    This assigns to the most local version of 'x',
			    which is of course the local variable.
>   END ;

>BEGIN
>   WriteLn( 'output: ', x )
>END.

    This works exactly as I would expect:
    the variable x gets the assignment, the function remains unassigned,
    and the writeln reports an uninitialised value.

    No bug that I can see.


    Alastair Milne