Re: Is this ground dead? Also, info on Mach that's more recent

[feladdress.peter@vtd.volvo.feladdress.se]

Checking at compile time is to put a bucket under the hole
instead of fixing the leak!

Typechecking done by the compiler is (IMHO) the wrong place.
It should be done at link time (or load time) .

Typechecking at compile time will among other things create
awful code at those times where typechecking is not wanted.
(like printf() ) and does not really prevent one from
screwing up arguments under all circumstances.



Very few existing systems does this however...

Peter h

Anonymous <nobody@REPLAY.COM> wrote:
: <34AE2AE8.ED17B2C6@gildea.net>
: <5lzpky66rq.fsf@tequila.systemsz.cs.yale.edu>
: <69jr4q$44j$1@encore.ece.cmu.edu> <tgmEMy5z4.9vs@netcom.com>

: On 17 Jan 1998 23:08:59 GMT, dacut@henry.ece.cmu.edu (David A. Cuthbert)
: wrote:

: > Thomas G. McWilliams <tgm@netcom.com> wrote:
: > >David A. Cuthbert <dacut@henry.ece.cmu.edu> wrote:
: > >: At any rate, relying on type safety for protection means that you
: > >: can't use C, C++, or assembly, or anything written in those
: > >: languages (so forget device drivers).  Assembly is the killer here;
: > >
: > >Have you used Ada?  Ada is type-safe and more powerful than C for
: > >low level bit-twiddling. Ada is a natural for device drivers and
: > >systems programming.
: > 
: > Used, no; glanced at code samples, yes.  My impression is that it
: > looks rather neat (nicer than C++ in many respects), but I've invested
: > too much into my C++ tools to even consider a switch.
: > 
: > I'm somewhat confused as to how Ada can be "natural" for device
: > drivers and systems programming.  For example, how do I code a task
: > switch or set up a DMA channel to a device in Ada?  Relying on a
: > library written in anything but Ada doesn't count.
: > 
: > Of course, I have no idea how I'd do that in C or C++, either, without
: > relying on nasty tricks like relying on assumptions about the
: > compiler's code generation and purposely breaking the type system.
: > 
: > -- 
: > David A. Cuthbert (dacut@ece.cmu.edu)
: > Graduate Student    Electrical and Computer Engineering
: > Data Storage Systems Center, Carnegie Mellon University
: > 
: > 

: Sounds as if you should learn Ada. Ada has low-level features for
: specifying where in memory variables reside and how they are
: represented, which are missing from C/++, and is type safe and easier to
: read than assembler.

: Since tasking is part of Ada, one doesn't generally code task switches
: explicitly in Ada. For other low-level operations, one generally does
: not need to break the type system or rely on assumptions about the
: compiler's code generation. Such operations are generally OS or hardware
: dependent, so I do not exclude relying on the features of the OS or
: hardware.

: Jeff Carter  PGP:1024/440FBE21
: My real e-mail address: ( carter @ innocon . com )
: "English bed-wetting types."
: Monty Python & the Holy Grail

: Posted with Spam Hater - see
: http://www.compulink.co.uk/~net-services/spam/

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