Re: [Boost-build] custom generator problems

Subject: Re: [Boost-build] custom generator problems
From: Vladimir Prus (ghost_at_[hidden])
Date: 2009-03-16 14:20:10

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.

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.

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.

As for path.glob -- no, this won't work -- the names of the targets, in your
case, must be known before we do initial dependency analysis.

- Volodya