Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!caen.engin.umich.edu!mystone
From: mystone@caen.engin.umich.edu (Dean Yu)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Bug in MPW Pascal 2.0.2 ???
Message-ID: <445d59a8.1285f@maize.engin.umich.edu>
Date: 11 Jul 89 04:00:00 GMT
References: <1270@draken.nada.kth.se>
Reply-To: mystone@sol.engin.umich.edu
Organization: Computer Aided Engineering Network, University of Michigan
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In article <1270@draken.nada.kth.se> d88-bli@nada.kth.se (Bo Lindbergh) writes:
>Consider the following Pascal program.
>
>   program bug;
>      var
>         u  : 0..65535;
>   begin
>      u:=60000;
>      writeln(u);
>   end.
>
>I can compile and link this without getting any rude messages,
>but when I run it, it prints
>   -5536
>when it should print
>   60000
>. Does anybody out there know whether this is
>   a) a previously known bug
>   b) a previously unknown bug
>   c) me demanding too much of the compiler?
>

  While I can't say if this is actually a bug or not, I would like to point
out that -5536 is the two's complement of 60000.  If the variable u is
being compiled as an integer, this would be correct.  So the question is,
should u have been compiled as a longint or an integer?  Human logic says that
the compiler should recognize that the range for u is larger than MaxInt, and
should therefore make u a long integer, but the compiler might be thinking that
it can store 65535 in one word and made u an integer...  

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