From: dewar@gnat.com
Subject: Re: Adding Things to Package System
Date: 1999/02/28
Date: 1999-02-28T00:00:00+00:00 [thread overview]
Message-ID: <7bahs4$m0a$1@nnrp1.dejanews.com> (raw)
In-Reply-To: F7tILv.GGv.0.-s@inmet.camb.inmet.com
In article <F7tILv.GGv.0.-s@inmet.camb.inmet.com>,
stt@houdini.camb.inmet.com (Tucker Taft) wrote:
> Ada 83 allowed additions to System, and to Standard
> for that matter. To write a portable Ada 83 program,
> you had to take this into account. Unfortunately, we
> could not easily eliminate this source of
> non-portabilities by Ada 95 fiat, given the > 100M LOC of
> Ada 83 code.
I disagree. I think we made a mistake here. We should NOT
have permitted such additions to System at all. This would
have the effect of requiring compilers to have a mode in
which no additions to System were allowed. They could also
have mechanisms for allowing such additions where they were
needed for compatibility.
Our experience with GNAT is that this is easy to do. The
normal mode in GNAT has ZERO additions to System, but we
can still easily provide complete compatibility with old
Ada 83 code that has such additions (e.g. we have a mode
in which we completely emulate the DEC Ada 83 System, which
has many additions).
Robert Dewar
Ada Core Technologies
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next prev parent reply other threads:[~1999-02-28 0:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-02-18 0:00 Adding Things to Package System Charles H. Sampson
1999-02-18 0:00 ` dewar
1999-02-20 0:00 ` Charles H. Sampson
1999-02-20 0:00 ` Matthew Heaney
1999-02-21 0:00 ` dewar
1999-02-23 0:00 ` Tucker Taft
1999-02-26 0:00 ` Charles H. Sampson
1999-02-27 0:00 ` Tucker Taft
1999-02-28 0:00 ` dewar [this message]
1999-02-28 0:00 ` robert_dewar
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