[Boost-build] execute subbuild system preprocess

Subject: [Boost-build] execute subbuild system preprocess
From: George Georgiev (george.georgiev.sf_at_[hidden])
Date: 2013-01-02 16:25:15

Hi,

I have a big project that currently uses a very old version of jam (the
original one). I would like to migrate it to boost build v2.

The project is too big to be migrated at once this is why my plan is to
start from the top (the projects with the most dependencies) to bottom. The
process during the migration will include 2 steps: 1. Build with the old
build system 2. Finish with the new build system

My question is: Is it possible to create a preprocess actions (actions that
are not related to any targets and are executed before the dependencies are
tracked). This will allow me to execute the first step from inside the bjam
project with providing all necessary arguments to the old build system
without need to create a sophisticated shell/batch scripts to do that.

Thanks in advance.
-g

P.S. I am sorry if this is already in the documentation - it is really hard
to google questions for boost build v2 itself, because the results are
intermingled with results for building the boost libraries.