To ANSI or not to ANSI (was: Re: Just a minor new twist on free())

[Paul D. Smith]

[] In article <PDS.90Oct8101336 at lemming.webo.dg.com> pds at lemming.webo.dg.com (Paul D. Smith) writes:
[] >My question is: since we now have a standard (whatever you may think
[] >of it, it is an internationally accepted definition of the C
[] >programming language), why do we have so much reluctance to
[] >embrace it?  In particular, how can you justify labelling a
[] >program "non-portable" if it follows the ANSI standard?
[]
[] The big question is:
[]
[]     How does it effect the performance, reliability, and/or
[]     readability of your code to make it "portable" to non-ANSI
[]     compilers?

These are good questions; another very important, and (to me) central
question is:

    What does it mean for a program to be "portable to non-ANSI
    compilers"?

By this I mean, if we want to be back-portable, what features should
we not use and which are we allowed to use?  Most of the replies I got
said things like:

    In general the ANSI features added are not hard to avoid using,
    except for things like enums and <<add a list of your own
    favourite "add on" C features>> ... so go ahead and use the common
    (but non-K&R I) features, but avoid the uncommon ones; they're not
    portable.

This seems to me to be inherently unportable.  Sure, most compilers
support some kind of enum statement, but what are the semantics?  I've
seen compilers which do not treat enum's as int's without casts, I've
even seen one which warns you about improper casts if you do them!

IMHO, if you're going to go whole-hog with interoperability, then you
have to have a definition of what you are interoperable with, and that
definition has to be very widely accepted; in my mind, significantly
*more* widely than the current availability of ANSI compliant
compilers, or else why bother?

The only definition I know of is K&R I, which, while I agree it's a
great book, just does not do the job as far as nitty-gritty
specifications of the entire language.  In addition, I don't think
I've seen a C program in the last 8 years which does not use any
language features except those found in K&R I!
--

                                                                paul
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| Paul D. Smith                          | pds at lemming.webo.dg.com |
| Data General Corp.                     |                         |
| Network Services Development           |   "Pretty Damn S..."    |
| Open Network Applications Department   |                         |
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