Re: Need help with PowerPC/Ada and realtime tasking

[JP Thornley <jpt@diphi.demon.co.uk>]

In article: <1996May30.103842.17355@ocsystems.com>  rec@ocsystems.com 
(Ralph E. Crafts) writes:
>                                 I don't believe that Phil is accurate
> in his statement that Ada 95 compilers "won't be usable" in the period
> from now to 1998-2000.  

This thread is about safety-critical software and "usable" has to be 
seen in that context.

Ralph, you may by now have seen my post on what it takes for us to 
accept a compiler - that post and your's crossed in my modem.

In particular there are severe requirements on what is a suitably mature 
compiler for us to start to look at it.  I haven't connected to see any 
responses to that post yet, but I'll be disappointed if no-one mentions 
GNAT (because I've made a bet with myself that some-one will).  However 
I imagine that GNAT would fail on stability grounds at the moment - 
there are clearly lots of users and lots of different sorts of use, but 
unless *one version* of it gets long-term usage, it can't be considered 
mature.

Your reference to continuing to add features suggests that PowerAda is 
in the same position.  (Please don't take this as a criticism - it's a
simple fact of life in the current state of the development of Ada 95
as a language.)

I often worry that safety-critical software development makes heavy 
demands on the supporting tools and the market for those tools is very 
small (I've seen a figure of 1% of Ada being safety-critical) so that 
long term vendor support must be questionable.  And I'll continue to 
worry even though at least two compiler vendors seem to be investing in 
this area at the moment.

Phil Thornley

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| JP Thornley    EMail jpt@diphi.demon.co.uk                           |
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