Re: [Boost-build] custom generator problems

Subject: Re: [Boost-build] custom generator problems
From: Michael Caisse (boost_at_[hidden])
Date: 2009-03-17 02:26:49

Hello Volodya -

Thank you for taking time to respond.

Vladimir Prus wrote:
> On Sunday 08 March 2009 08:12:57 Michael Caisse wrote:
> > I am trying to create a custom generator for a code generator.
> > The code generator takes a single description file in and
> > produces several CPP and HPP files.
> >
> > The produced filenames are not known before hand; however, I
> > have them generated into a known directory. I was hoping to
> > path.glob the code generated files but I am starting to think
> > that this isn't going to work.
> >
> > Before I devote much more time to this approach is this even possible?
> > Can I create rules that determine targets only after some
> > action is performed (the code generator runs and the directory is glob'd)?
> >   
>
> Hmm, how are you planning on doing dependency analysis in this case?
> Say, your tool takes a.in and produces a bunch of cpps. To know if the
> tool should be run, we need to compare checksum of a.in with the checksums
> of the files it will produce -- and running the tool in the first
> place seems wasteful. The tool itself might run in no time, but the .cpp
> files need compilation.

One thought was to take a.in and produce an empty (touch) a.out file for
timestamp/dependency purposes. The tool would then create the various .cpp and
.h files in a known directory containing only the generated sources. My problem
has been finding a way to feedback the generated .cpp files as targets that
now need to be compiled.

> Is there any reasonable way to extract the names from the input file? (Say,
> using a Python script). If so, you can build Boost.Jam with Python support
> and run this code to determine the file names.
This might be possible. If I were to attempt this, is there an example of
building/using bjam with Python support?

> If the above is not possible -- is it possible to write a script that runs
> the tool, but in a temporary directory, and reports the list of files
> that are produced? Such a script can be then run using SHELL builtin.
This is possible. Sorry if I am slow, but I don't see how I will get the generated
filenames into Boost.Build afterward so that the .cpp will be compiled.


Thank you for your time.

Best Regards -
Michael

-- 

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Michael Caisse
Object Modeling Designs
www.objectmodelingdesigns.com