Function __write_appender

v2/test/generators_test.py:344–429

(t, name)

def __write_appender(t, name):
    t.write(name,
r"""# Copyright 2012 Jurko Gospodnetic
# 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)

#   Support for registering test generators that construct their targets by
# simply appending their given input data, e.g. list of sources & targets.

import "class" : new ;
import generators ;
import modules ;
import sequence ;

rule register ( id composing ? : source-types + : target-types + )
{
    local caller-module = [ CALLER_MODULE ] ;
    id = $(caller-module).$(id) ;
    local g = [ new generator $(id) $(composing) : $(source-types) :
        $(target-types) ] ;
    $(g).set-rule-name $(__name__).appender ;
    generators.register $(g) ;
    return $(id) ;
}

if [ modules.peek : NT ]
{
    X = ")" ;
    ECHO_CMD = (echo. ;
}
else
{
    X = \" ;
    ECHO_CMD = "echo $(X)" ;
}

local appender-runs ;

# We set up separate actions for building each target in order to avoid having
# to iterate over them in action (i.e. shell) code. We have to be extra careful
# though to achieve the exact same effect as if doing all the work in just one
# action. Otherwise Boost Jam might, under some circumstances, run only some of
# our actions. To achieve this we register a series of actions for all the
# targets (since they all have the same target list - either all or none of them
# get run independent of which target actually needs to get built), each
# building only a single target. Since all our actions use the same targets, we
# can not use 'on-target' parameters to pass data to a specific action so we
# pass them using the second 'sources' parameter which our actions then know how
# to interpret correctly. This works well since Boost Jam does not automatically
# add dependency relations between specified action targets & sources and so the
# second argument, even though most often used to pass in a list of sources, can
# actually be used for passing in any type of information.
rule appender ( targets + : sources + : properties * )
{
    appender-runs = [ CALC $(appender-runs:E=0) + 1 ] ;
    local target-index = 0 ;
    local target-count = [ sequence.length $(targets) ] ;