Date: Tue, 4 Apr 2006 17:19:33 -0500 (CDT) From: Lars Eighner <eighner@io.com> To: Jung-uk Kim <jkim@FreeBSD.org> Cc: freebsd-stable@FreeBSD.org Subject: Re: Is Makefile.inc1 in 6 wrong? Message-ID: <20060404170708.D76810@goodwill.io.com> In-Reply-To: <200604041752.15909.jkim@FreeBSD.org> References: <20060404160100.U76190@goodwill.io.com> <200604041726.17120.jkim@FreeBSD.org> <20060404163058.J76542@goodwill.io.com> <200604041752.15909.jkim@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 4 Apr 2006, Jung-uk Kim wrote:
> On Tuesday 04 April 2006 05:32 pm, Lars Eighner wrote:
>> On Tue, 4 Apr 2006, Jung-uk Kim wrote:
>>> On Tuesday 04 April 2006 05:14 pm, Lars Eighner wrote:
>>>> It appears to me that either I have a wrong version of awk or
>>>> this Makefile.inc1 is wrong:
>>>>
>>>> #
>>>> # $FreeBSD: src/Makefile.inc1,v 1.499.2.11 2006/04/04 14:24:03
>>>> glebius Exp $ #
>>>>
>>>> <Snippage>
>>>>
>>>> MAKEOBJDIRPREFIX?= /usr/obj
>>>> .if !defined(OSRELDATE)
>>>> .if exists(/usr/include/osreldate.h)
>>>> OSRELDATE!= awk '/^\#define[[:space:]]*__FreeBSD_version/ {
>>>> print $$3 }' \ /usr/include/osreldate.h
>>>> .else
>>>> OSRELDATE= 0
>>>>
>>>>
>>>> In particular with the double dollar sign in the awk statement,
>>>> I get no return, therefore OSRELDATE gets set to 0. The awk
>>>> statement also fails from the command line. But if I use only
>>>> one $, the awk statement succeeds.
>>>>
>>>> Is there a reason for the double dollar sign?
>>>
>>> Yes. See make(1):
>>>
>>> $ A single dollar sign `$', i.e. `$$' expands to a single
>>> dollar sign.
I think this is wrong for a SINGLE QUOTED argument to be passed
to awk. The Makefile is wrong. I am right.
>>
>> Then why does it get the wrong answer?
>
> Because you ran it from command line. ;-) You can copy and paste the
> same lines to *Makefile* like this:
>
> ------------
> .if !defined(OSRELDATE)
> .if exists(/usr/include/osreldate.h)
> OSRELDATE!= awk '/^\#define[[:space:]]*__FreeBSD_version/ { print $$3 }' \
> /usr/include/osreldate.h
> .else
> OSRELDATE= 0
> .endif
> .endif
>
> all:
> @echo "reldate = ${OSRELDATE}"
> ------------
>
> and run make. You will see something like this (depending on your
> header file):
>
> %make
> reldate = 600034
But it doesn't
[1;42;37mTue Apr 04 17:11:38 bash3.1:ttyp0:eighner
goodwill~$[0mmake -V OSRELDATE -f /usr/src/Makefile.inc1
0
[1;42;37mTue Apr 04 17:12:25 bash3.1:ttyp0:eighner
goodwill~$[0mexit
exit
where /usr/include/osreldate.h =
/*-
* Copyright (c) 1992-2006 The FreeBSD Project.
* All rights reserved.
<snippage>
* SUCH DAMAGE.
*
*/
#ifdef _KERNEL
#error "<osreldate.h> cannot be used in the kernel, use <sys/param.h>"
#else
#undef __FreeBSD_version
#define __FreeBSD_version 504105
#endif
>
>> Also is there a difference when the accent mark is used in front
>> instead of a real single quote?
>
> Where do you see it?
Where you wrote:
>>> $ A single dollar sign `$', i.e. `$$' expands to a single
>>> dollar sign.
And also in man make. The ` is an accent key, not a quote key.
Yes, they are aka backticks and do mean something when they are
paired, but `something' is nonsense so far as I can tell.
Why would make tamper with anything in single quotes that is
passed to a command? How do you write an argument for a command
so that make won't tamper with it? What would double quoting
the argument be for?
--
Lars Eighner
eighner@io.com lars@larseighner.com
http://www.larseighner.com/index.html
8800 N IH35 APT 1191 AUSTIN TX 78753-5266
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060404170708.D76810>