Proposal: 'notfile' main target

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-04-11 08:31:35

I think it would be good to add a target that just runs some command, without 
creating any files. When such target is built, the command is just run, and 
no up-to-date checks are made for any files.

There are two use cases.

1. In my projects the system tests are run with some rather long command. I'd 
like to just type "bjam system-tests" and run that command. 

2. Recently, Cédric wanted to run some tool on source .dsp files. And there's 
no way to tell what the tool does and what files it produces. The tool just 
must be run.

I propose this interface:

notfile <name> : <action> : <sources> 
: <requirements> ... all the regular paramenters ;

The <action> parameter can have two forms:

1. "some command" in which case the command is run verbatim

For example

notfile say : "echo hi" ;  

2. @name_of_the_rule, in which can the named rule/action will be invoked. For 
example:

notfile hello_valgrind : @valgrind : hello ;

actions valgrind
{
valgrind $(>)
}

The first will just execute the command. The second will invoke the 'valgrind' 
tool on the source -- the 'hello' target.

The implementation is ready -- it actually took me less time to code than 
writing this message ;-) Any comments?

-- 
Vladimir Prus
http://vladimir_prus.blogspot.com
Boost.Build V2: http://boost.org/boost-build2