1# Copyright 2005 Vladimir Prus. 2# Distributed under the Boost Software License, Version 1.0. (See 3# accompanying file LICENSE_1_0.txt or copy at 4# http://www.boost.org/LICENSE_1_0.txt) 5 6# Defines main target 'cast', used to change type for target. For example, in Qt 7# library one wants two kinds of CPP files -- those that just compiled and those 8# that are passed via the MOC tool. 9# 10# This is done with: 11# 12# exe main : main.cpp [ cast _ moccable-cpp : widget.cpp ] ; 13# 14# B2 will assign target type CPP to both main.cpp and widget.cpp. Then, 15# the cast rule will change target type of widget.cpp to MOCCABLE-CPP, and Qt 16# support will run the MOC tool as part of the build process. 17# 18# At the moment, the 'cast' rule only works for non-derived (source) targets. 19# 20# TODO: The following comment is unclear or incorrect. Clean it up. 21# > Another solution would be to add a separate main target 'moc-them' that 22# > would moc all the passed sources, no matter what their type is, but I prefer 23# > cast, as defining a new target type + generator for that type is somewhat 24# > simpler than defining a main target rule. 25 26import "class" : new ; 27import project ; 28import property-set ; 29import targets ; 30import type ; 31 32 33class cast-target-class : typed-target 34{ 35 import type ; 36 37 rule __init__ ( name : project : type : sources * : requirements * : 38 default-build * : usage-requirements * ) 39 { 40 typed-target.__init__ $(name) : $(project) : $(type) : $(sources) : 41 $(requirements) : $(default-build) : $(usage-requirements) ; 42 } 43 44 rule construct ( name : source-targets * : property-set ) 45 { 46 local result ; 47 for local s in $(source-targets) 48 { 49 if ! [ class.is-a $(s) : file-target ] 50 { 51 import errors : user-error : errors.user-error ; 52 errors.user-error Source to the 'cast' rule is not a file! ; 53 } 54 if [ $(s).action ] 55 { 56 import errors : user-error : errors.user-error ; 57 errors.user-error Only non-derived target are allowed for 58 'cast'. : when building [ full-name ] ; 59 } 60 local r = [ $(s).clone-with-different-type $(self.type) ] ; 61 result += [ virtual-target.register $(r) ] ; 62 } 63 return [ property-set.empty ] $(result) ; 64 } 65} 66 67 68rule cast ( name type : sources * : requirements * : default-build * : 69 usage-requirements * ) 70{ 71 local project = [ project.current ] ; 72 73 local real-type = [ type.type-from-rule-name $(type) ] ; 74 if ! $(real-type) 75 { 76 import errors ; 77 errors.user-error No type corresponds to the main target rule name 78 '$(type)' : "Hint: try a lowercase name" ; 79 } 80 81 targets.main-target-alternative [ new cast-target-class $(name) : $(project) 82 : $(real-type) 83 : [ targets.main-target-sources $(sources) : $(name) ] 84 : [ targets.main-target-requirements $(requirements) : $(project) ] 85 : [ targets.main-target-default-build $(default-build) : $(project) ] 86 : [ targets.main-target-usage-requirements $(usage-requirements) : 87 $(project) ] ] ; 88} 89 90 91IMPORT $(__name__) : cast : : cast ; 92