Re: [Boost-build] "null" output file type

From: Matthew Herrmann (matthew.herrmann_at_[hidden])
Date: 2006-02-27 16:48:12

On Monday 27 February 2006 18:23, boost-build-request_at_[hidden] wrote:

Hi Volodya,

> Hi Matthew,
>
> > I'd like to register a pre-compile test which needs to run before
> > compiling our apps. This is to check for required libraries being
> > installed, paths set up, etc. The unit test output types are not suitable
> > since they takes built executables as a dependency, rather than being an
> > allowable dependency themselves.
> >
> > My approach was to register a file type, say CONFIGURE_CHECK, which would
> > contain a shell script that ran and produced a file on success (and no
> > file and non-zero error code on failure):
> >
> > lib my_library
> >
> >     : pre_test.configure_check [ glob *.cpp ]
> >
> >     ...
> >     ;
> >
> > This fits well with the bjam file-based dependency design, and I could
> > then register a configure_check file type and users would only be forced
> > to re-check config on changes to the script.
> >
> > Question is: how do I make *.configure_check files ignored by the c++
> > compilation steps? Is there a modular way to do this? One hack is to just
> > output a .o (OBJ) file with no defined symbols, but I'd rather not.
>
> Well, don't put 'pre_test.configure_check' to sources:
>
>   lib my_library
>  
>      : [ glob *.cpp ]
>      : <dependency>pre_test.configure_check
>      ;
>
> Assuming your configure check does not puts files into source directory,
> but only to build directory, this will have the right effect.
>
> In fact, is there any reason why your configure check creates .o files? I'm
> not 100% understand the approach you took.
>
> - Volodya

Thanks for that, that looks like just what I need.

<check.jam>
import type ;
type.register CHECK_SCRIPT : check ;
import generators ;
generators.register-standard check.run_script : CHECK_SCRIPT : OBJ ;
actions run_script
{
    echo Running checking script...
    rm -f $(<)
    $SHELL $(>)
    if test $? -eq 0 ; then
        touch $(<)
        exit 0
    else
        exit 1
    fi
}
</check.jam>

I needed to specify a dependency without changing the behaviour of the items 
following. 

-- 
Matthew Herrmann
matthew.herrmann_at_[hidden]
Vice President, Software Architecture
Zomojo Pty Ltd