From: Hartmut Kaiser (hartmutkaiser_at_[hidden])
Date: 2004-02-26 09:59:28
Sam Partington wrote:
> On Fri, 20 Feb 2004 16:09:56 -0500, David Abrahams
> <dave_at_[hidden]> wrote:
> > There are pre-generated headers in boost/mpl/aux_/preprocessed/...
> > Those are the ones that actually get used.
>
> What generates these files? We use the preprocessor library
> for boiler plate code here and there and find it very useful.
>
> But one of the critisms voiced is that debugging the
> generated code is
> difficult->impossible (all debug info points at the same line in the
> code!). What we really want is a way of preprocessing the
> code as a separate stage in the build process.
>
> We could (and occasionally do) output the preprocessed files,
> but that means all of the headers are pulled in, and all of
> the comments stripped out.
If you need or would like to debug your preprocessing code you may want to
have a look at the tracing capabilities provided by the Wave preprocessor.
It allows you to get a very dedicated macro expansion trace of a certain
macro, which allows to track down nasty pp problems (and BTW is very
educational, what actually is going on inside the Boost.PP library).
Regards Hartmut