Date: Thu, 19 Jun 2008 12:32:15 +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: <485A35AF.3060703@FreeBSD.org> In-Reply-To: <485A3552.9000803@FreeBSD.org> References: <484EAFAC.3020208@FreeBSD.org> <485A3314.8010304@FreeBSD.org> <485A3552.9000803@FreeBSD.org>
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Kris Kennaway wrote:
| Pietro Cerutti wrote:
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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})
|
| Try $$(${SCHED_NAME}) (escape the $ you don't want make to process)
mh yep... :) tnx!
|
| Kris
- --
Pietro Cerutti
gahr@FreeBSD.org
PGP Public Key:
http://gahr.ch/pgp
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