# Copyright (c) 2018 Stefan Seefeld
#
# Use, modification and distribution is subject to the Boost Software
# License Version 1.0. (See accompanying file LICENSE_1_0.txt or
# http://www.boost.org/LICENSE_1_0.txt)

# Supports the opencl library
#
# After 'using opencl', the following targets are available:
#
# /opencl//opencl -- The OpenCL library

import project ;
import ac ;
import errors ;
import feature ;
import "class" : new ;
import targets ; 
import modules ;
import property-set ;

header = CL/cl.h ;
names = OpenCL ;

library-id = 0 ;

if --debug-configuration in [ modules.peek : ARGV ]
{
    .debug =  true ;
}

# Initializes the opencl library.
#
# Options for configuring opencl::
#
#   <search>
#       The directory containing the OpenCL library.
#   <name>
#       Overrides the default library name.
#   <include>
#       The directory containing the OpenCL headers.
#
# Examples::
#
#   # Find OpenCL in the default system location
#   using opencl ;
#   # Find opencl in /usr/local
#   using opencl : 1.2.7
#     : <include>/usr/local/include <search>/usr/local/lib ;
#
rule init ( version ? : # The opencl version (currently ignored)
            options * : # A list of the options to use
            requirements * ) # The requirements for the opencl target
{
    local caller = [ project.current ] ;

    if ! $(.initialized)
    {
        .initialized = true ;

        project.initialize $(__name__) ;
        .project = [ project.current ] ;
        project opencl ;
    }

    local library-path = [ feature.get-values <search> : $(options) ] ;
    local include-path = [ feature.get-values <include> : $(options) ] ;
    local library-name = [ feature.get-values <name> : $(options) ] ;

    if ! $(library-path) && ! $(include-path) && ! $(library-name)
    {
        is-default = true ;
    }

    condition = [ property-set.create $(requirements) ] ;
    condition = [ property-set.create [ $(condition).base ] ] ;

    if $(.configured.$(condition))
    {
        if $(is-default)
        {
            if $(.debug)
            {
                ECHO "notice: [opencl] opencl is already configured" ;
            }
        }
        else
        {
            errors.user-error "opencl is already configured" ;
        }
        return ;
    }
    else
    {
        if $(.debug)
        {
            ECHO "notice: [opencl] Using pre-installed library" ;
            if $(condition)
            {
                ECHO "notice: [opencl] Condition" [ $(condition).raw ] ;
            }
        }

        local mt = [ new ac-library opencl : $(.project) : $(condition) :
            $(include-path) : $(library-path) : $(library-name) ] ;
        $(mt).set-header $(header) ;
        $(mt).set-default-names $(names) ;
        targets.main-target-alternative $(mt) ;
    }
    .configured.$(condition) = true ;
}