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From: browns@iccgcc.decnet.ab.com (Stan Brown)
Newsgroups: comp.std.c
Subject: Re: #error
Message-ID: <4392.281abeb4@iccgcc.decnet.ab.com>
Date: 28 Apr 91 17:23:16 GMT
References: <14793@darkstar.ucsc.edu> <1991Apr22.075125.6828@tkou02.enet.dec.com> <18721@crdgw1.crd.ge.com> <1991Apr23.000427.14716@tkou02.enet.dec.com>
Lines: 30

In article <1991Apr23.000427.14716@tkou02.enet.dec.com>, diamond@jit345.swstokyo.dec.com (Norman Diamond) writes:
> As far as I can tell, if an #error directive is correctly
> processed and obeyed, the processor still has to proceed to translate
> the program successfully, unless an implementation limit is exceeded.

This is definitely false.  I quote from the Rationale that accompanies
the standard (sec 3.8.5, Error directive):
    The directive #error has been introduced to provide an explicit
    mechanism for forcing translation to fail under certain conditions.
    (Formally the Standard only requires, _can_ only require, that a
    diagnostic be issued when the #error directive is effected.  It is
    the intent of the Committee, however, that translation cease
    immediately upon encountering this directive, if this is feasible in
    the implementation; further diagnostics on text beyond the directive
    are apt to be of little value.)  Traditionally such failure has had
    to be forced by inserting text so ill-formed that the translator
    gagged on it.
(emphasis in original)

So we have the official interpretation that a program can die upon
reading #error and producing the required diagnostic, but that the
implementation is within its rights in continuing translation.  That
much is clear.

What I don't understand is why the standard could not explicitly require
an immediate end to translation?

Stan Brown, Oak Road Systems, Cleveland, Ohio, USA    +1 216 371 0043
                   email (until 91/4/30): browns@iccgcc.decnet.ab.com
My opinions are mine:  I don't speak for any other person or company.