Date: Thu, 19 Jun 2008 12:21:08 +0200 From: Pietro Cerutti <gahr@FreeBSD.org> To: Kris Kennaway <kris@FreeBSD.org> Cc: ports@FreeBSD.org Subject: Re: INDEX build optimizations - please review Message-ID: <485A3314.8010304@FreeBSD.org> In-Reply-To: <484EAFAC.3020208@FreeBSD.org> References: <484EAFAC.3020208@FreeBSD.org>
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Kris Kennaway wrote:
| **********************************************************************
| ********************* NOTE TO PORT DEVELOPERS ************************
| **********************************************************************
|
| Variable assignments with != are bad! Try as hard as you can to avoid
| using them -- especially in Mk/*! Every time something processes your
| makefile it will spawn a command, even if it is not relevant for the
| operation being performed. If you need to run shell commands, try to
| isolate them within a makefile target. You can avoid code duplication
| by assigning the *shell commands* (not their output) to a variable and
| inserting it into your code block.
|
| e.g. instead of
|
| --
| VARIABLE!= do some shell stuff; do some other stuff
|
| target:
| echo ${VARIABLE}
| --
|
| do this (or similar):
|
| --
| VARIABLE_CMDS= do some shell stuff; do some other stuff
|
| target:
| echo $(${VARIABLE_CMDS})
| --
|
| This defers the command execution to the point where the target runs, so
| in the case when the target is *not* run, then you avoid wasting one or
| more process executions.
Yes, in theory.
Any clue why this doesn't work?
SCHED_NAME= sysctl -n kern.sched.name
all:
~ echo $(${SCHED_NAME})
|
| Kris
|
- --
Pietro Cerutti
gahr@FreeBSD.org
PGP Public Key:
http://gahr.ch/pgp
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