Re: Help on gcc

["James Dressler" <jamesmdr at hotmail dot com>]

For those that believe in "Free Software": read carefully the e-mails 
exchanged between me and Mr. Oliva, who answers by GCC (a free C++ 
Compiler)...

------------------------------------------------------------------
Here begins my answer to you, Mr. Oliva:

It's a simple example, only to show the point.

I'm happy to tell you that it's impossible, on a operational system like 
Solaris, Windows NT, Windows 2000, Linux and any other Unix-like system, to 
"destroy the world" using a NULL pointer, because this is a logical address. 
There is a Memory Management Unit to map the logical address to physical 
address, what make impossible that using a NULL pointer do any harm. And I'm 
just using a not too much technical language, to make it easier for you to 
understand.

Imagine, for example, that it's not a NULL pointer, but a pointer that 
dereferences an area of memory, previously allocated using "new", that has 
been already returned to the operational system by a "delete" statement. It 
will not work too. No exception raised.

For your information, although I think you already know, it works on 
Microsoft C++ Compiler, and many others C++ Compilers. To be happy, like you 
said, it's better to go with them. Probably you think that gcc is a joke, 
something to play with. You convinced me.

And I don't see any relation between my sister and C++. I guess if someone 
at Microsoft gave me an awful answer like you, what would happen to him. 
Probably, he would be fired. That's what you deserve.

Best regards
James M. Dressler


>From: Alexandre Oliva <aoliva@redhat.com>
>To: "James Dressler" <jamesmdr@hotmail.com>
>CC: gcc@gcc.gnu.org
>Subject: Re: Help on gcc
>Date: 05 Feb 2002 19:10:26 -0200
>
>On Feb  5, 2002, "James Dressler" <jamesmdr@hotmail.com> wrote:
>
> > does not work, never prints "captured"
>
>Dereferencing a NULL pointer invokes undefined behavior, so the crash
>you get is in perfect accordance with the Standard, and it is indeed
>the expected behavior.  In fact, be happy that the program didn't
>format your hard disk, destroy the universe nor go out with your
>sister :-)  It might throw an exception, but that's not what most would
>expect from C++ programs in this situation.  C++ != Java :-)
>
>--
>Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
>Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
>CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
>Free Software Evangelist                Professional serial bug killer





James Masi Dressler

DBKi Software
===============
www.dbki.com.br
===============


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