Mailing-List:	contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe:	<mailto:cygwin-subscribe AT sources DOT redhat DOT com>
List-Archive:	<http://sources.redhat.com/ml/cygwin/>
List-Post:	<mailto:cygwin AT sources DOT redhat DOT com>
List-Help:	<mailto:cygwin-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender:	cygwin-owner AT sources DOT redhat DOT com
Delivered-To:	mailing list cygwin AT sources DOT redhat DOT com
Date:	Wed, 7 Feb 2001 13:24:08 +0000 (GMT Standard Time)
From:	Robert Bogomip <bob DOT bogo AT milohedge DOT com>
To:	Scott Carter <scarter AT emware DOT com>
cc:	<cygwin AT cygwin DOT com>
Subject:	RE: make 3.79: core dump expanding target specific variables
In-Reply-To:	<C76DE572EEEBD41180A10002A507E4080C0110@anasazi.emware.com>
Message-ID:	<Pine.WNT.4.33.0102071311140.1384-100000@pang>
X-X-Sender:	iestyn AT blade DOT ox DOT mathengine DOT com
MIME-Version:	1.0

On Tue, 6 Feb 2001, Scott Carter wrote:
>
> I don't have a explanation/solution for the core dump, but here's a
> explanation of why you get [ 2] rather than [2]
>
> http://sources.redhat.com/ml/cygwin/2000-07/msg00816.html
> (summary: += inserts a space.)
>

No, I don't think so when this is the first time the variable is defined.
If we use the original Makefile without the target specific variables we
have:

  t+=2

  t:
	@echo "[${t}]"

giving:

  $ make all
  [2]
  $

on all versions of make I have (3.77, 3.78, 3.79 on Linux & cygwin). The
docs say

 "objects += another.o

  This takes the value of the variable objects, and adds the text
  `another.o' to it (preceded by a single space)."

and a little further down,

 "When the variable in question has not been defined before, `+=' acts
  just like normal `=': it defines a recursively-expanded variable."

A little ambiguous, but the tests above confirm that a space is only
inserted if ${t} already exists (even if it is empty).



BTW, the original core dump occurs on Linux make 3.79 too, so I suppose
it's a real make bug.
-- 
Robert Bogomip /// mailto:bob DOT bogo AT milohedge DOT com
Milo Hedge Ltd, OCFI, Mill Street, Oxford, OX2 0JX /// tel:+44 1865 799400


--
Want to unsubscribe from this list?
Check out: http://cygwin.com/ml/#unsubscribe-simple

- Raw text -