Re: failure due to compiler?

Ian Moor <iwm@doc.ic.ac.uk> writes:
>The main problem was explaining to a class of beginners progammers
>why their programs failed.


Well, if you want compiler failures that hurt a bunch of beginners,
you really can't go past SPARCompiler Pascal.


The environment:


        y% uname -a
        SunOS yallara 5.5.1 Generic sun4u sparc SUNW,Ultra-Enterprise
        y% pc -V
        pc: SC4.0 18 Oct 1995 Pascal 4.0
        Usage: pc [ options ] files. Use 'pc -flags' for details


The *legal* standard Pascal program:


        y% cat foo.pas
        program foo(output);


var
main: boolean;


        begin


main := true;
writeln(main);


        end.


The result:


        y% pc foo.pas
        y% a.out
        Illegal Instruction (core dumped)


Sun's official reaction is that this isn't a bug, it's a feature.
You see, in this Pascal compiler, all top-level identifiers are
*automatically* also top-level C identifiers. Fortunately, the -s1
option (ISO 7185 level 1) option *now* gives the right answer:


        y% pc -s1 foo.pas
        y% a.out
          TRUE


At the time when I was using Pascal in a course, this apparently
didn't help, and it confused the heck out of the several students
who innocently ran into it.


The compiler otherwise has a lot to commend it. I particularly like
the -Rw option. I wish it supported a few features from the current
standard, though (modules, instead of leaking into C, would be at the
top of the list).


--
Richard A. O'Keefe; http://www.cs.rmit.edu.au/~ok; RMIT Comp.Sci.
--

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