Re: Buffer overflow Article - CACM

["robin" <robin_v@bigpond.com>]

<jimmaureenrogers@worldnet.att.net> wrote in message
news:1136173025.947352.25110@g44g2000cwa.googlegroups.com...
> robin wrote:
> > "Martin Krischik" <krischik@users.sourceforge.net> wrote in message
> > news:4626568.XPZCFmT196@linux1.krischik.com...
>
> > > > PL/I can compile and execute the following source.  Can Ada do the same
> > > > for PL/I?
> > > >
> > > > Mixed: procedure options (main);
> > > >     ...
> > > > ADA(
> > > > StringReverse (S: Text) return Text is
> > > > begin
> > > >     if Length(S) <= 1
> > > >        then return S;
> > > >        else return StringReverse(Tail(S)) & Head(S);
> > > > end StringReverse;
> > > > );
> > > > end mixed;
> > > >
> > > > [I have not written here the PL/I code for TAIL and HEAD,
> > > > nor the declarations for the variables corresponding
> > > > to S and Text.]
> > >
> > > From the top of my head
> > >
> > > package PL_1
> > >
> > >   function String_Reverse (S : in String) return String is
> > >   begin
> > >      if S'Lenght <= 1 then
> > >        return S;
> > >      else
> > >        return String_Reverse (Tail(S)) & Head(S);
> > >      end if
> > >   end String_Reverse;
> > > end PL_1;
> >
> > This is Ada code, not PL/I code.  I already supplied
> > Ada code in the PL/I source example above.
>
> I was just as confused as Martin. Your "Ada" code is not correct Ada
> code.
>
> There is no standard Ada type named "text".

The Ada code presented is obviously an extract, part of an Ada program.
I wasn't about to type the whole Ada program; that would be a WOT.
It's sufficient to give an extract.

> Your Ada example will not compile under any Ada compiler as written.

Obviously, it would need the missing elements that I mentioned.

> You indicate that TAIL and HEAD are PL/I routines.
> They will not compile in any Ada compiler given the code segment
> you presented.

The PL/I routines will compile with a PL/I compiler.

> Where is the Length function defined? It is certainly not defined in
> any of the code you present.
>
> If your example compiles in a PL/I compiler with the assumption
> that it is Ada code, then I marvel at the usefulness. Why would
> you want a compiler that does not identify serious syntax errors?

There are no Ada errors in the code.