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From: ok@goanna.cs.rmit.edu.au (Richard A. O'Keefe)
Subject: Re: Ada and robots
Date: 1997/06/27
Message-ID: <5ovcgk$6f4$1@goanna.cs.rmit.edu.au>#1/1
X-Deja-AN: 254692258
References: <9706262213.AA13647@stealth.ctron.com>
Organization: Comp Sci, RMIT University, Melbourne, Australia.
Newsgroups: comp.lang.ada
NNTP-Posting-User: ok
Date: 1997-06-27T00:00:00+00:00
List-Id: <comp.lang.ada>


Huy Vo <vo@CTRON.COM> writes:
>In C, it's as simple as

>  if (!(cp =malloc(BIG_CHUNK)) {
>    fprintf(stderr, "Buy some more ram, i died at line %d\n", __LINE__);
>    exit(1);
>   }

A nice example of what can go wrong with C.
(1) exit(1) is not portable.  (At my suggestion, lclint can check for this.)
    In some important C systems, exit(1) indicates _success_, not failure.
    It should be exit(EXIT_FAILURE), or better still, abort().

(2) A typical C program has many more source files than one.  If you tell
    me what line number, what good does that do?

(3) "Good" C for this would be something like
	#define New(p, n) \
	    if (((p) = malloc((n))) != 0) {} else assert(!"malloc failed")
    which will, I'm afraid, provoke warnings from lint and other checkers
    (empty if-part, constant condition).

-- 
Four policemen playing jazz on an up escalator in the railway station.
Richard A. O'Keefe; http://www.cs.rmit.edu.au/%7Eok; RMIT Comp.Sci.