boost/tools/build/src/contrib/modular.jam

# Copyright Rene Rivera 2015
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE_1_0.txt or copy at
# http://www.boost.org/LICENSE_1_0.txt)

#alias library
#    :
#    : : : <include>include
#    ;

import path ;
import project ;
import modules ;
import regex ;

rule find ( target-refs + )
{
    process-args ;
    
    local caller-mod = [ CALLER_MODULE ] ;
    local caller-dir = [ modules.peek $(caller-mod) : __file__ ] ;
    caller-dir = $(caller-dir:D) ;
    caller-dir = [ path.root $(caller-dir) [ path.pwd ] ] ;
    
    for local target-ref in $(target-refs)
    {
        local ref = [ MATCH ^(.*)//.* : $(target-ref:G=) ] ;
        local search-prefix ;
        local search-sub ;
        for local prefix in $(.search-path-prefix)
        {
            if ! $(search-prefix)
            {
                local search-match = [ MATCH ^($(prefix))/(.*)$ : $(ref) ] ;
                search-prefix = $(search-match[1]) ;
                search-sub = $(search-match[2]) ;
            }
        }
        local found = [ path.glob $(.search-path.$(search-prefix)) : $(search-sub) ] ;
        found = $(found[1]) ;
        if $(found)
        {
            local lib-ref = [ regex.split $(search-sub) / ] ;
            lib-ref = $(search-prefix)/$(lib-ref[1]) ;
            local lib-path = [ path.relative-to $(caller-dir) $(found) ] ;
            library $(lib-ref) $(caller-mod) : $(lib-path) ;
        }
    }
    
    return $(target-refs) ;
}

rule library ( name caller-module ? : root )
{
    process-args ;
    
    # Dir path of caller to base paths from.
    caller-module ?= [ CALLER_MODULE ] ;
    local caller-dir = [ modules.peek $(caller-module) : __file__ ] ;
    caller-dir = $(caller-dir:D) ;
    
    # Find the various parts of the library.
    local lib-dir = [ path.root [ path.root $(root) $(caller-dir) ] [ path.pwd ] ] ;
    local lib-contents = [ path.glob $(lib-dir) : "include" "build" ] ;
    lib-contents = $(lib-contents:D=) ;
    # "include" dir for library..
    local include-dir ;
    if "include" in $(lib-contents)
    {
        include-dir = include ;
    }
    
    # Does it look like a library?
    if $(include-dir)
    {
        # Load/create/declare library project.
        local lib-module = [ project.find $(root) : $(caller-dir) ] ;
        if ! $(lib-module)
        {
            lib-module = [ project.load
                [ path.root [ path.make $(root) ] $(caller-dir) ] : synthesize ] ;
        }
        local lib-target = [ project.target $(lib-module) ] ;
        
        # We move to the library project module to define the various
        # targets others use for the library.
        if ! [ modules.peek $(lib-module) : __library__ ]
        {
            modules.poke $(lib-module) : __library__ : $(name) ;
            project.push-current $(lib-target) ;
            
            # Declare the library alias.
            modules.call-in $(lib-module) : alias library
                : # Sources
                : # Requirements
                : # Default Build
                : # Usage Requirements
                	<include>$(include-dir)
                ;
            
            project.pop-current ;
        }
        
        # Declare project alternate ID.
        modules.call-in $(caller-module) : use-project $(name) : $(root) ;
    }
}

# Add a location, i.e. directory, where to search for libraries.
# The optional 'prefix' indicates which rooted-prefixes the new
# search dir applies to. The prefix defaults to '/'.
rule add-location ( dir prefix ? : base-dir ? )
{
    process-args ;
    
    prefix ?= "/" ;
    
    # Dir path of caller to base paths from.
    caller-module ?= [ CALLER_MODULE ] ;
    local caller-dir = [ modules.peek $(caller-module) : __file__ ] ;
    caller-dir = $(caller-dir:D) ;
    
    base-dir ?= $(caller-dir) ;
    
    .search-path-prefix += $(prefix) ;
    .search-path.$(prefix) += [ path.root [ path.root $(dir) $(base-dir) ] [ path.pwd ] ] ;
}

local rule process-args ( )
{
    if ! $(.did-process-args)
    {
        .did-process-args = yes ;
        local argv = [ modules.peek : ARGV ] ;
        local dirs = [ MATCH ^--modular-search-dir=(.*)$ : $(argv) ] ;
        for local dir in $(dirs)
        {
            add-location $(dir) : [ path.pwd ] ;
        }
    }
}