[Boost-build] [v2] Directories as generator sources?

From: K. Noel Belcourt (kbelco_at_[hidden])
Date: 2006-09-19 15:35:31

Hi,

I'm trying to register a composing generator that accepts only  
directory paths, not source files, from which the target is built.  I  
register the generator by omitting the source-types from the  
registration line.

// xmldb.jam

import generator ;
import type ;

type.register XMLDB : xmldb ;
generators.register-composing xmldb.action : : XMLDB ;

actions xmldb.action
{
   "xmlc" $(<) $(>)
}

So far, so good.  Now I attempt to use the rule that BBv2 defines by  
default for newly registered types.

xmldb framework : parser ;

Where parser is a directory, not a file.  BBv2 complains

error: Unable to find file or target named
error: 'parser'

Any idea how I can build a target with directories, not files, as  
sources?  The program invoked in the action (xmlc) requires a list  
of, one or more, directories.  Since it doesn't depend on any files,  
I thought I'd use a composing generator to pass in a list of  
directories but that doesn't work.

Any ideas on how to do this?

Thanks.

-- Noel Belcourt