property.jam

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# Copyright 2001, 2002, 2003 Dave Abrahams
# Copyright 2006 Rene Rivera
# Copyright 2002, 2003, 2004, 2005, 2006 Vladimir Prus
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)

import errors ;
import feature ;
import indirect ;
import path ;
import regex ;
import string ;
import sequence ;
import set ;
import utility ;


# Refines 'properties' by overriding any non-free and non-conditional properties
# for which a different value is specified in 'requirements'. Returns the
# resulting list of properties.
#
rule refine ( properties * : requirements * )
{
    local result ;
    local error ;

    # All the 'requirements' elements should be present in the result. Record
    # them so that we can handle 'properties'.
    for local r in $(requirements)
    {
        # Do not consider conditional requirements.
        if ! [ MATCH (:) : $(r:G=) ]
        {
            # Note: cannot use a local variable here, so use an ugly name.
            __require__$(r:G) = $(r:G=) ;
        }
    }

    for local p in $(properties)
    {
        if [ MATCH (:) : $(p:G=) ]
        {
            # Do not modify conditional properties.
            result += $(p) ;
        }
        else if free in [ feature.attributes $(p:G) ]
        {
            # Do not modify free properties.
            result += $(p) ;
        }
        else
        {
            local required-value = $(__require__$(p:G)) ;
            if $(required-value)
            {
                if $(p:G=) != $(required-value)
                {
                    result += $(p:G)$(required-value) ;
                }
                else
                {
                    result += $(p) ;
                }
            }
            else
            {
                result += $(p) ;
            }
        }
    }

    # Unset our ugly map.
    for local r in $(requirements)
    {
        __require__$(r:G) = ;
    }

    if $(error)
    {
        return $(error) ;
    }
    else
    {
        return [ sequence.unique $(result) $(requirements) ] ;
    }
}


# Removes all conditional properties whose conditions are not met. For those
# with met conditions, removes the condition. Properties in conditions are
# looked up in 'context'.
#
rule evaluate-conditionals-in-context ( properties * : context * )
{
    local base ;
    local conditionals ;
    for local p in $(properties)
    {
        if [ MATCH (:<) : $(p) ]
        {
            conditionals += $(p) ;
        }
        else
        {
            base += $(p) ;
        }
    }

    local result = $(base) ;
    for local p in $(conditionals)
    {
        # Separate condition and property.
        local s = [ MATCH (.*):(<.*) : $(p) ] ;
        # Split condition into individual properties.
        local c = [ regex.split $(s[1]) "," ] ;
        # Evaluate condition.
        if $(c) in $(context)
        {
            result += $(s[2]) ;
        }
    }
    return $(result) ;
}


rule expand-subfeatures-in-conditions ( properties * )
{
    local result ;
    for local p in $(properties)
    {
        local s = [ MATCH (.*):(<.*) : $(p) ] ;
        if ! $(s)
        {
            result += $(p) ;
        }
        else
        {
            local condition = $(s[1]) ;
            local value     = $(s[2]) ;
            # Condition might include several elements.
            condition = [ regex.split $(condition) "," ] ;
            local e ;
            for local c in $(condition)
            {
                # It is common for a condition to include a toolset or
                # subfeatures that have not been defined. In that case we want
                # the condition to simply 'never be satisfied' and validation
                # would only produce a spurious error so we prevent it by
                # passing 'true' as the second parameter.
                e += [ feature.expand-subfeatures $(c) : true ] ;
            }
            if $(e) = $(condition)
            {
                # (todo)
                #   This is just an optimization and possibly a premature one at
                # that.
                #                             (todo) (12.07.2008.) (Jurko)
                result += $(p) ;
            }
            else
            {
                result += $(e:J=,):$(value) ;
            }
        }
    }
    return $(result) ;
}


# Helper for as-path, below. Orders properties with the implicit ones first, and
# within the two sections in alphabetical order of feature name.
#
local rule path-order ( x y )
{
    if $(y:G) && ! $(x:G)
    {
        return true ;
    }
    else if $(x:G) && ! $(y:G)
    {
        return ;
    }
    else
    {
        if ! $(x:G)
        {
            x = [ feature.expand-subfeatures $(x) ] ;
            y = [ feature.expand-subfeatures $(y) ] ;
        }

        if $(x[1]) < $(y[1])
        {
            return true ;
        }
    }
}


local rule abbreviate-dashed ( string )
{
    local r ;
    for local part in [ regex.split $(string) - ]
    {
        r += [ string.abbreviate $(part) ] ;
    }
    return $(r:J=-) ;
}


local rule identity ( string )
{
    return $(string) ;
}


if --abbreviate-paths in [ modules.peek : ARGV ]
{
    .abbrev = abbreviate-dashed ;
}
else
{
    .abbrev = identity ;
}


# Returns a path representing the given expanded property set.
#
rule as-path ( properties * )
{
    local entry = .result.$(properties:J=-) ;

    if ! $($(entry))
    {
        # Trim redundancy.
        properties = [ feature.minimize $(properties) ] ;

        # Sort according to path-order.
        properties = [ sequence.insertion-sort $(properties) : path-order ] ;

        local components ;
        for local p in $(properties)
        {
            if $(p:G)
            {
                local f = [ utility.ungrist $(p:G) ] ;
                p = $(f)-$(p:G=) ;
            }
            components += [ $(.abbrev) $(p) ] ;
        }

        $(entry) = $(components:J=/) ;
    }

    return $($(entry)) ;
}


# Exit with error if property is not valid.
#
local rule validate1 ( property )
{
    local msg ;
    if $(property:G)
    {
        local feature = $(property:G) ;
        local value = $(property:G=) ;

        if ! [ feature.valid $(feature) ]
        {
            # Ungrist for better error messages.
            feature = [ utility.ungrist $(property:G) ] ;
            msg = "unknown feature '$(feature)'" ;
        }
        else if $(value) && ! free in [ feature.attributes $(feature) ]
        {
            feature.validate-value-string $(feature) $(value) ;
        }
        else if ! ( $(value) || ( optional in [ feature.attributes $(feature) ] ) )
        {
            # Ungrist for better error messages.
            feature = [ utility.ungrist $(property:G) ] ;
            msg = "No value specified for feature '$(feature)'" ;
        }
    }
    else
    {
        local feature = [ feature.implied-feature $(property) ] ;
        feature.validate-value-string $(feature) $(property) ;
    }
    if $(msg)
    {
        errors.error "Invalid property "'$(property:J=" ")'": "$(msg:J=" "). ;
    }
}


rule validate ( properties * )
{
    for local p in $(properties)
    {
        validate1 $(p) ;
    }
}


rule validate-property-sets ( property-sets * )
{
    for local s in $(property-sets)
    {
        validate [ feature.split $(s) ] ;
    }
}


# Expands any implicit property values in the given property 'specification' so
# they explicitly state their feature.
#
rule make ( specification * )
{
    local result ;
    for local e in $(specification)
    {
        if $(e:G)
        {
            result += $(e) ;
        }
        else if [ feature.is-implicit-value $(e) ]
        {
            local feature = [ feature.implied-feature $(e) ] ;
            result += $(feature)$(e) ;
        }
        else
        {
            errors.error "'$(e)' is not a valid property specification" ;
        }
    }
    return $(result) ;
}


# Returns a property set containing all the elements in 'properties' that do not
# have their attributes listed in 'attributes'.
#
rule remove ( attributes + : properties * )
{
    local result ;
    for local e in $(properties)
    {
        if ! [ set.intersection $(attributes) : [ feature.attributes $(e:G) ] ]
        {
            result += $(e) ;
        }
    }
    return $(result) ;
}


# Returns a property set containing all the elements in 'properties' that have
# their attributes listed in 'attributes'.
#
rule take ( attributes + : properties * )
{
    local result ;
    for local e in $(properties)
    {
        if [ set.intersection $(attributes) : [ feature.attributes $(e:G) ] ]
        {
            result += $(e) ;
        }
    }
    return $(result) ;
}


# Selects properties corresponding to any of the given features.
#
rule select ( features * : properties * )