Merge branch 'master' of https://github.com/redpony/cdec

1 files changed, 0 insertions, 1089 deletions

diff --git a/jam-files/boost-build/build/generators.py b/jam-files/boost-build/build/generators.py
deleted file mode 100644
index 2c59f7ca..00000000
--- a/jam-files/boost-build/build/generators.py
+++ /dev/null
@@ -1,1089 +0,0 @@
-# Status: being ported by Vladimir Prus
-# Base revision: 48649
-# TODO: replace the logging with dout
-
-# Copyright Vladimir Prus 2002.
-# Copyright Rene Rivera 2006.
-#
-# 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)
-
-#  Manages 'generators' --- objects which can do transformation between different
-#  target types and contain algorithm for finding transformation from sources
-#  to targets.
-#
-#  The main entry point to this module is generators.construct rule. It is given
-#  a list of source targets, desired target type and a set of properties.
-#  It starts by selecting 'viable generators', which have any chances of producing
-#  the desired target type with the required properties. Generators are ranked and
-#  a set of most specific ones is selected.
-# 
-#  The most specific generators have their 'run' methods called, with the properties
-#  and list of sources. Each one selects target which can be directly consumed, and
-#  tries to convert the remaining ones to the types it can consume. This is done
-#  by recursively calling 'construct' with all consumable types.
-#
-#  If the generator has collected all the targets it needs, it creates targets 
-#  corresponding to result, and returns it. When all generators have been run,
-#  results of one of them are selected and returned as result.
-#
-#  It's quite possible that 'construct' returns more targets that it was asked for.
-#  For example, it was asked to target type EXE, but the only found generators produces
-#  both EXE and TDS (file with debug) information. The extra target will be returned.
-#
-#  Likewise, when generator tries to convert sources to consumable types, it can get
-#  more targets that it was asked for. The question is what to do with extra targets.
-#  Boost.Build attempts to convert them to requested types, and attempts as early as
-#  possible. Specifically, this is done after invoking each generator. (Later I'll 
-#  document the rationale for trying extra target conversion at that point).
-#
-#  That early conversion is not always desirable. Suppose a generator got a source of
-#  type Y and must consume one target of type X_1 and one target of type X_2.
-#  When converting Y to X_1 extra target of type Y_2 is created. We should not try to
-#  convert it to type X_1, because if we do so, the generator will get two targets
-#  of type X_1, and will be at loss as to which one to use. Because of that, the
-#  'construct' rule has a parameter, telling if multiple targets can be returned. If
-#  the parameter is false, conversion of extra targets is not performed.
-
-
-import re
-import cStringIO
-import os.path
-
-from virtual_target import Subvariant
-import virtual_target, type, property_set, property
-from b2.util.logger import *
-from b2.util.utility import *
-from b2.util import set
-from b2.util.sequence import unique
-import b2.util.sequence as sequence
-from b2.manager import get_manager
-import b2.build.type
-
-def reset ():
-    """ Clear the module state. This is mainly for testing purposes.
-    """
-    global __generators, __type_to_generators, __generators_for_toolset, __construct_stack
-    global __overrides, __active_generators
-    global __viable_generators_cache, __viable_source_types_cache
-    global __vstg_cached_generators, __vst_cached_types
-
-    __generators = {}
-    __type_to_generators = {}
-    __generators_for_toolset = {}
-    __overrides = {}
-    
-    # TODO: can these be global? 
-    __construct_stack = []
-    __viable_generators_cache = {}
-    __viable_source_types_cache = {}
-    __active_generators = []
-
-    __vstg_cached_generators = []
-    __vst_cached_types = []
-
-reset ()
-
-_re_separate_types_prefix_and_postfix = re.compile ('([^\\(]*)(\\((.*)%(.*)\\))?')
-_re_match_type = re.compile('([^\\(]*)(\\(.*\\))?')
-
-
-__debug = None
-__indent = ""
-
-def debug():
-    global __debug
-    if __debug is None:
-        __debug = "--debug-generators" in bjam.variable("ARGV")        
-    return __debug
-
-def increase_indent():
-    global __indent
-    __indent += "    "
-
-def decrease_indent():
-    global __indent
-    __indent = __indent[0:-4]
-
-
-# Updated cached viable source target type information as needed after a new
-# derived target type gets added. This is needed because if a target type is a
-# viable source target type for some generator then all of the target type's
-# derived target types are automatically viable as source target types for the
-# same generator. Does nothing if a non-derived target type is passed to it.
-#
-def update_cached_information_with_a_new_type(type):
-
-    base_type = b2.build.type.base(type)
-
-    if base_type:
-        for g in __vstg_cached_generators:
-            if base_type in __viable_source_types_cache.get(g, []):
-                __viable_source_types_cache[g].append(type)
-
-        for t in __vst_cached_types:
-            if base_type in __viable_source_types_cache.get(t, []):
-                __viable_source_types_cache[t].append(type)
-
-# Clears cached viable source target type information except for target types
-# and generators with all source types listed as viable. Should be called when
-# something invalidates those cached values by possibly causing some new source
-# types to become viable.
-#
-def invalidate_extendable_viable_source_target_type_cache():
-
-    global __vstg_cached_generators
-    generators_with_cached_source_types = __vstg_cached_generators
-    __vstg_cached_generators = []
-
-    for g in generators_with_cached_source_types:
-        if __viable_source_types_cache.has_key(g):
-            if __viable_source_types_cache[g] == ["*"]:
-                __vstg_cached_generators.append(g)
-            else:
-                del __viable_source_types_cache[g]
-
-    global __vst_cached_types
-    types_with_cached_sources_types = __vst_cached_types
-    __vst_cached_types = []
-    for t in types_with_cached_sources_types:
-        if __viable_source_types_cache.has_key(t):
-            if __viable_source_types_cache[t] == ["*"]:
-                __vst_cached_types.append(t)
-            else:
-                del __viable_source_types_cache[t]
- 
-def dout(message):
-    if debug():
-        print __indent + message
-
-class Generator:
-    """ Creates a generator.
-            manager:                 the build manager.
-            id:                      identifies the generator
-            
-            rule:                    the rule which sets up build actions.
-
-            composing:               whether generator processes each source target in
-                                     turn, converting it to required types.
-                                     Ordinary generators pass all sources together to
-                                     recusrive generators.construct_types call.
-
-            source_types (optional): types that this generator can handle
-    
-            target_types_and_names:  types the generator will create and, optionally, names for
-                                     created targets. Each element should have the form
-                                         type["(" name-pattern ")"]
-                                     for example, obj(%_x). Name of generated target will be found
-                                     by replacing % with the name of source, provided explicit name
-                                     was not specified.
-    
-            requirements (optional)
-            
-            NOTE: all subclasses must have a similar signature for clone to work!
-    """
-    def __init__ (self, id, composing, source_types, target_types_and_names, requirements = []):
-        assert(not isinstance(source_types, str))
-        assert(not isinstance(target_types_and_names, str))
-        self.id_ = id
-        self.composing_ = composing
-        self.source_types_ = source_types
-        self.target_types_and_names_ = target_types_and_names
-        self.requirements_ = requirements
-        
-        self.target_types_ = []
-        self.name_prefix_ = []
-        self.name_postfix_ = []
-        
-        for e in target_types_and_names:
-            # Create three parallel lists: one with the list of target types,
-            # and two other with prefixes and postfixes to be added to target 
-            # name. We use parallel lists for prefix and postfix (as opposed
-            # to mapping), because given target type might occur several times,
-            # for example "H H(%_symbols)".
-            m = _re_separate_types_prefix_and_postfix.match (e)
-            
-            if not m:
-                raise BaseException ("Invalid type and name '%s' in declaration of type '%s'" % (e, id))
-            
-            target_type = m.group (1)
-            if not target_type: target_type = ''
-            prefix = m.group (3)
-            if not prefix: prefix = ''
-            postfix = m.group (4)
-            if not postfix: postfix = ''
-            
-            self.target_types_.append (target_type)
-            self.name_prefix_.append (prefix)
-            self.name_postfix_.append (postfix)
-
-        for x in self.source_types_:
-            type.validate (x)
-
-        for x in self.target_types_:
-            type.validate (x)
-
-    def clone (self, new_id, new_toolset_properties):
-        """ Returns another generator which differers from $(self) in
-              - id
-              - value to <toolset> feature in properties
-        """
-        return self.__class__ (new_id, 
-                               self.composing_, 
-                               self.source_types_, 
-                               self.target_types_and_names_,
-                               # Note: this does not remove any subfeatures of <toolset>
-                               # which might cause problems
-                               property.change (self.requirements_, '<toolset>') + new_toolset_properties)
-
-    def clone_and_change_target_type(self, base, type):
-        """Creates another generator that is the same as $(self), except that
-        if 'base' is in target types of $(self), 'type' will in target types
-        of the new generator."""
-        target_types = []
-        for t in self.target_types_and_names_:
-            m = _re_match_type.match(t)
-            assert m
-            
-            if m.group(1) == base:
-                if m.group(2):
-                    target_types.append(type + m.group(2))
-                else:
-                    target_types.append(type)
-            else:
-                target_types.append(t)
-
-        return self.__class__(self.id_, self.composing_,
-                              self.source_types_,
-                              target_types,
-                              self.requirements_)
-                              
-
-    def id(self):
-        return self.id_
-
-    def source_types (self):
-        """ Returns the list of target type the generator accepts.
-        """
-        return self.source_types_
-
-    def target_types (self):
-        """ Returns the list of target types that this generator produces.
-            It is assumed to be always the same -- i.e. it cannot change depending
-            list of sources.    
-        """
-        return self.target_types_
-
-    def requirements (self):
-        """ Returns the required properties for this generator. Properties
-            in returned set must be present in build properties if this 
-            generator is to be used. If result has grist-only element,
-            that build properties must include some value of that feature.
-        """
-        return self.requirements_
-
-    def match_rank (self, ps):
-        """ Returns true if the generator can be run with the specified 
-            properties.
-        """
-        # See if generator's requirements are satisfied by
-        # 'properties'.  Treat a feature name in requirements
-        # (i.e. grist-only element), as matching any value of the
-        # feature.
-        all_requirements = self.requirements ()
-        
-        property_requirements = []
-        feature_requirements = []
-        # This uses strings because genenator requirements allow
-        # the '<feature>' syntax without value and regular validation
-        # is not happy about that.
-        for r in all_requirements:
-            if get_value (r):
-                property_requirements.append (r)
-
-            else:
-                feature_requirements.append (r)
-                
-        return all(ps.get(get_grist(s)) == [get_value(s)] for s in property_requirements) \
-               and all(ps.get(get_grist(s)) for s in feature_requirements)
-        
-    def run (self, project, name, prop_set, sources):
-        """ Tries to invoke this generator on the given sources. Returns a
-            list of generated targets (instances of 'virtual-target').
-
-            project:        Project for which the targets are generated.
-            
-            name:           Determines the name of 'name' attribute for 
-                            all generated targets. See 'generated_targets' method.
-                            
-            prop_set:       Desired properties for generated targets.
-            
-            sources:        Source targets.
-        """
-        
-        if project.manager ().logger ().on ():
-            project.manager ().logger ().log (__name__, "  generator '%s'" % self.id_)
-            project.manager ().logger ().log (__name__, "  composing: '%s'" % self.composing_)
-        
-        if not self.composing_ and len (sources) > 1 and len (self.source_types_) > 1:
-            raise BaseException ("Unsupported source/source_type combination")
-                
-        # We don't run composing generators if no name is specified. The reason
-        # is that composing generator combines several targets, which can have
-        # different names, and it cannot decide which name to give for produced
-        # target. Therefore, the name must be passed.
-        #
-        # This in effect, means that composing generators are runnable only
-        # at top-level of transofrmation graph, or if name is passed explicitly.
-        # Thus, we dissallow composing generators in the middle. For example, the
-        # transofrmation CPP -> OBJ -> STATIC_LIB -> RSP -> EXE won't be allowed 
-        # (the OBJ -> STATIC_LIB generator is composing)
-        if not self.composing_ or name:
-            return self.run_really (project, name, prop_set, sources)
-        else:
-            return []
-
-    def run_really (self, project, name, prop_set, sources):
-
-        # consumed: Targets that this generator will consume directly.
-        # bypassed: Targets that can't be consumed and will be returned as-is.
-        
-        if self.composing_:
-            (consumed, bypassed) = self.convert_multiple_sources_to_consumable_types (project, prop_set, sources)
-        else:
-            (consumed, bypassed) = self.convert_to_consumable_types (project, name, prop_set, sources)
-                
-        result = []
-        if consumed:
-            result = self.construct_result (consumed, project, name, prop_set)
-            result.extend (bypassed)
-
-        if result:
-            if project.manager ().logger ().on ():
-                project.manager ().logger ().log (__name__, "  SUCCESS: ", result)
-
-        else:
-                project.manager ().logger ().log (__name__, "  FAILURE")
-
-        return result
-
-    def construct_result (self, consumed, project, name, prop_set):
-        """ Constructs the dependency graph that will be returned by this 
-            generator.
-                consumed:        Already prepared list of consumable targets
-                                 If generator requires several source files will contain 
-                                 exactly len $(self.source_types_) targets with matching types
-                                 Otherwise, might contain several targets with the type of 
-                                 self.source_types_ [0]
-                project:
-                name:
-                prop_set:        Properties to be used for all actions create here
-        """
-        result = []
-        # If this is 1->1 transformation, apply it to all consumed targets in order.
-        if len (self.source_types_) < 2 and not self.composing_:
-
-            for r in consumed:
-                result.extend (self.generated_targets ([r], prop_set, project, name))
-
-        else:
-
-            if consumed:
-                result.extend (self.generated_targets (consumed, prop_set, project, name))
-
-        return result
-
-    def determine_target_name(self, fullname):
-        # Determine target name from fullname (maybe including path components)
-        # Place optional prefix and postfix around basename
-
-        dir = os.path.dirname(fullname)
-        name = os.path.basename(fullname)
-
-        if dir and not ".." in dir and not os.path.isabs(dir):
-            # Relative path is always relative to the source
-            # directory. Retain it, so that users can have files
-            # with the same in two different subdirectories.
-            name = dir + "/" + name
-
-        return name
-
-    def determine_output_name(self, sources):
-        """Determine the name of the produced target from the
-        names of the sources."""
-        
-        # The simple case if when a name
-        # of source has single dot. Then, we take the part before
-        # dot. Several dots can be caused by:
-        # - Using source file like a.host.cpp
-        # - A type which suffix has a dot. Say, we can
-        #   type 'host_cpp' with extension 'host.cpp'.
-        # In the first case, we want to take the part till the last
-        # dot. In the second case -- no sure, but for now take
-        # the part till the last dot too.
-        name = os.path.splitext(sources[0].name())[0]
-                        
-        for s in sources[1:]:
-            n2 = os.path.splitext(s.name())
-            if n2 != name:
-                get_manager().errors()(
-                    "%s: source targets have different names: cannot determine target name"
-                    % (self.id_))
-                        
-        # Names of sources might include directory. We should strip it.
-        return self.determine_target_name(sources[0].name())
-        
-        
-    def generated_targets (self, sources, prop_set, project, name):
-        """ Constructs targets that are created after consuming 'sources'.
-            The result will be the list of virtual-target, which the same length
-            as 'target_types' attribute and with corresponding types.
-            
-            When 'name' is empty, all source targets must have the same value of 
-            the 'name' attribute, which will be used instead of the 'name' argument.
-            
-            The value of 'name' attribute for each generated target will be equal to
-            the 'name' parameter if there's no name pattern for this type. Otherwise,
-            the '%' symbol in the name pattern will be replaced with the 'name' parameter 
-            to obtain the 'name' attribute.
-            
-            For example, if targets types are T1 and T2(with name pattern "%_x"), suffixes
-            for T1 and T2 are .t1 and t2, and source if foo.z, then created files would
-            be "foo.t1" and "foo_x.t2". The 'name' attribute actually determined the
-            basename of a file.
-            
-            Note that this pattern mechanism has nothing to do with implicit patterns
-            in make. It's a way to produce target which name is different for name of 
-            source.
-        """
-        if not name:
-            name = self.determine_output_name(sources)
-        
-        # Assign an action for each target
-        action = self.action_class()
-        a = action(project.manager(), sources, self.id_, prop_set)
-                
-        # Create generated target for each target type.
-        targets = []
-        pre = self.name_prefix_
-        post = self.name_postfix_
-        for t in self.target_types_:
-            basename = os.path.basename(name)
-            idx = basename.find(".")
-            if idx != -1:
-                basename = basename[:idx]
-            generated_name = pre[0] + basename + post[0]
-            generated_name = os.path.join(os.path.dirname(name), generated_name)
-            pre = pre[1:]
-            post = post[1:]
-            
-            targets.append(virtual_target.FileTarget(generated_name, t, project, a))
-        
-        return [ project.manager().virtual_targets().register(t) for t in targets ]
-
-    def convert_to_consumable_types (self, project, name, prop_set, sources, only_one=False):
-        """ Attempts to convert 'source' to the types that this generator can
-            handle. The intention is to produce the set of targets can should be
-            used when generator is run.
-            only_one:   convert 'source' to only one of source types
-                        if there's more that one possibility, report an
-                        error.
-                        
-            Returns a pair:
-                consumed: all targets that can be consumed. 
-                bypassed: all targets that cannot be consumed.
-        """
-        consumed = []
-        bypassed = []
-        missing_types = [] 
-
-        if len (sources) > 1:
-            # Don't know how to handle several sources yet. Just try 
-            # to pass the request to other generator
-            missing_types = self.source_types_
-
-        else:
-            (c, m) = self.consume_directly (sources [0])
-            consumed += c
-            missing_types += m
-        
-        # No need to search for transformation if
-        # some source type has consumed source and
-        # no more source types are needed.
-        if only_one and consumed:
-            missing_types = []
-            
-        #TODO: we should check that only one source type
-        #if create of 'only_one' is true.
-        # TODO: consider if consuned/bypassed separation should
-        # be done by 'construct_types'.
-                    
-        if missing_types:
-            transformed = construct_types (project, name, missing_types, prop_set, sources)
-                                
-            # Add targets of right type to 'consumed'. Add others to
-            # 'bypassed'. The 'generators.construct' rule has done
-            # its best to convert everything to the required type.
-            # There's no need to rerun it on targets of different types.
-                
-            # NOTE: ignoring usage requirements
-            for t in transformed[1]:
-                if t.type() in missing_types:
-                    consumed.append(t)
-
-                else:
-                    bypassed.append(t)
-        
-        consumed = unique(consumed)
-        bypassed = unique(bypassed)
-        
-        # remove elements of 'bypassed' that are in 'consumed'
-        
-        # Suppose the target type of current generator, X is produced from 
-        # X_1 and X_2, which are produced from Y by one generator.
-        # When creating X_1 from Y, X_2 will be added to 'bypassed'
-        # Likewise, when creating X_2 from Y, X_1 will be added to 'bypassed'
-        # But they are also in 'consumed'. We have to remove them from
-        # bypassed, so that generators up the call stack don't try to convert
-        # them. 
-
-        # In this particular case, X_1 instance in 'consumed' and X_1 instance
-        # in 'bypassed' will be the same: because they have the same source and
-        # action name, and 'virtual-target.register' won't allow two different
-        # instances. Therefore, it's OK to use 'set.difference'.
-        
-        bypassed = set.difference(bypassed, consumed)
-
-        return (consumed, bypassed)
-    
-
-    def convert_multiple_sources_to_consumable_types (self, project, prop_set, sources):
-        """ Converts several files to consumable types.
-        """        
-        consumed = []
-        bypassed = []
-
-        # We process each source one-by-one, trying to convert it to
-        # a usable type.
-        for s in sources:
-            # TODO: need to check for failure on each source.
-            (c, b) = self.convert_to_consumable_types (project, None, prop_set, [s], True)
-            if not c:
-                project.manager ().logger ().log (__name__, " failed to convert ", s)
-
-            consumed.extend (c)
-            bypassed.extend (b)
-
-        return (consumed, bypassed)
-
-    def consume_directly (self, source):
-        real_source_type = source.type ()
-
-        # If there are no source types, we can consume anything
-        source_types = self.source_types()
-        if not source_types:
-            source_types = [real_source_type]            
-
-        consumed = []
-        missing_types = []
-        for st in source_types:
-            # The 'source' if of right type already)
-            if real_source_type == st or type.is_derived (real_source_type, st):
-                consumed.append (source)
-
-            else:
-               missing_types.append (st)
-
-        return (consumed, missing_types)
-    
-    def action_class (self):
-        """ Returns the class to be used to actions. Default implementation 
-            returns "action".
-        """
-        return virtual_target.Action
-
-
-def find (id):
-    """ Finds the generator with id. Returns None if not found.
-    """
-    return __generators.get (id, None)
-
-def register (g):
-    """ Registers new generator instance 'g'.
-    """
-    id = g.id()
-
-    __generators [id] = g
-
-    # A generator can produce several targets of the
-    # same type. We want unique occurence of that generator
-    # in .generators.$(t) in that case, otherwise, it will
-    # be tried twice and we'll get false ambiguity.
-    for t in sequence.unique(g.target_types()):
-        __type_to_generators.setdefault(t, []).append(g)
-
-    # Update the set of generators for toolset
-
-    # TODO: should we check that generator with this id
-    # is not already registered. For example, the fop.jam
-    # module intentionally declared two generators with the
-    # same id, so such check will break it.
-
-    # Some generators have multiple periods in their name, so the
-    # normal $(id:S=) won't generate the right toolset name.
-    # e.g. if id = gcc.compile.c++, then
-    # .generators-for-toolset.$(id:S=) will append to
-    # .generators-for-toolset.gcc.compile, which is a separate
-    # value from .generators-for-toolset.gcc. Correcting this
-    # makes generator inheritance work properly.
-    # See also inherit-generators in module toolset
-    base = id.split ('.', 100) [0]
-
-    __generators_for_toolset.setdefault(base, []).append(g)
-
-    # After adding a new generator that can construct new target types, we need
-    # to clear the related cached viable source target type information for
-    # constructing a specific target type or using a specific generator. Cached
-    # viable source target type lists affected by this are those containing any
-    # of the target types constructed by the new generator or any of their base
-    # target types.
-    #
-    # A more advanced alternative to clearing that cached viable source target
-    # type information would be to expand it with additional source types or
-    # even better - mark it as needing to be expanded on next use.
-    #
-    # For now we just clear all the cached viable source target type information
-    # that does not simply state 'all types' and may implement a more detailed
-    # algorithm later on if it becomes needed.
-
-    invalidate_extendable_viable_source_target_type_cache()
-
-
-def register_standard (id, source_types, target_types, requirements = []):
-    """ Creates new instance of the 'generator' class and registers it.
-        Returns the creates instance.
-        Rationale: the instance is returned so that it's possible to first register
-        a generator and then call 'run' method on that generator, bypassing all
-        generator selection.
-    """
-    g = Generator (id, False, source_types, target_types, requirements)
-    register (g)
-    return g
-
-def register_composing (id, source_types, target_types, requirements = []):
-    g = Generator (id, True, source_types, target_types, requirements)
-    register (g)
-    return g
-
-def generators_for_toolset (toolset):
-    """ Returns all generators which belong to 'toolset'.
-    """
-    return __generators_for_toolset.get(toolset, [])
-
-def override (overrider_id, overridee_id):
-    """Make generator 'overrider-id' be preferred to
-    'overridee-id'. If, when searching for generators
-    that could produce a target of certain type,
-    both those generators are amoung viable generators,
-    the overridden generator is immediately discarded.
-    
-    The overridden generators are discarded immediately
-    after computing the list of viable generators, before
-    running any of them."""
-    
-    __overrides.get(overrider_id, []).append(overridee_id)
-
-def __viable_source_types_real (target_type):
-    """ Returns a list of source type which can possibly be converted
-        to 'target_type' by some chain of generator invocation.
-        
-        More formally, takes all generators for 'target_type' and
-        returns union of source types for those generators and result
-        of calling itself recusrively on source types.
-    """
-    generators = []
-
-    # 't0' is the initial list of target types we need to process to get a list
-    # of their viable source target types. New target types will not be added to
-    # this list.         
-    t0 = type.all_bases (target_type)
-
-
-    # 't' is the list of target types which have not yet been processed to get a
-    # list of their viable source target types. This list will get expanded as
-    # we locate more target types to process.
-    t = t0
-    
-    result = []
-    while t:
-        # Find all generators for current type. 
-        # Unlike 'find_viable_generators' we don't care about prop_set.
-        generators = __type_to_generators.get (t [0], [])
-        t = t[1:]
-        
-        for g in generators:
-            if not g.source_types():
-                # Empty source types -- everything can be accepted
-                result = "*"
-                # This will terminate outer loop.
-                t = None
-                break
-            
-            for source_type in g.source_types ():
-                if not source_type in result:
-                    # If generator accepts 'source_type' it
-                    # will happily accept any type derived from it
-                    all = type.all_derived (source_type)
-                    for n in all:
-                        if not n in result:
-
-                            # Here there is no point in adding target types to
-                            # the list of types to process in case they are or
-                            # have already been on that list. We optimize this
-                            # check by realizing that we only need to avoid the
-                            # original target type's base types. Other target
-                            # types that are or have been on the list of target
-                            # types to process have been added to the 'result'
-                            # list as well and have thus already been eliminated
-                            # by the previous if.
-                            if not n in t0:
-                                t.append (n)
-                            result.append (n)
-           
-    return result
-
-
-def viable_source_types (target_type):
-    """ Helper rule, caches the result of '__viable_source_types_real'.
-    """
-    if not __viable_source_types_cache.has_key(target_type):
-        __vst_cached_types.append(target_type)
-        __viable_source_types_cache [target_type] = __viable_source_types_real (target_type)
-    return __viable_source_types_cache [target_type]
-
-def viable_source_types_for_generator_real (generator):
-    """ Returns the list of source types, which, when passed to 'run'
-        method of 'generator', has some change of being eventually used
-        (probably after conversion by other generators)
-    """
-    source_types = generator.source_types ()
-
-    if not source_types:
-        # If generator does not specify any source types,
-        # it might be special generator like builtin.lib-generator
-        # which just relays to other generators. Return '*' to
-        # indicate that any source type is possibly OK, since we don't
-        # know for sure.
-        return ['*']
-
-    else:
-        result = []
-        for s in source_types:
-            viable_sources = viable_source_types(s)
-            if viable_sources == "*":
-                result = ["*"]
-                break
-            else:
-                result.extend(type.all_derived(s) + viable_sources)
-        return unique(result)
-
-def viable_source_types_for_generator (generator):
-    """ Caches the result of 'viable_source_types_for_generator'.
-    """
-    if not __viable_source_types_cache.has_key(generator):
-        __vstg_cached_generators.append(generator)
-        __viable_source_types_cache[generator] = viable_source_types_for_generator_real (generator)
-    
-    return __viable_source_types_cache[generator]
-
-def try_one_generator_really (project, name, generator, target_type, properties, sources):
-    """ Returns usage requirements + list of created targets.
-    """
-    targets = generator.run (project, name, properties, sources)
-
-    usage_requirements = []
-    success = False
-
-    dout("returned " + str(targets))
-
-    if targets:
-        success = True;
-        
-        if isinstance (targets[0], property_set.PropertySet):
-            usage_requirements = targets [0]
-            targets = targets [1]
-
-        else:
-            usage_requirements = property_set.empty ()
-
-    dout(  "  generator" + generator.id() + " spawned ")
-    #    generators.dout [ indent ] " " $(targets) ; 
-#    if $(usage-requirements)
-#    {
-#        generators.dout [ indent ] "  with usage requirements:" $(x) ;
-#    }
-
-    if success:
-        return (usage_requirements, targets)
-    else:
-        return None
-
-def try_one_generator (project, name, generator, target_type, properties, sources):
-    """ Checks if generator invocation can be pruned, because it's guaranteed
-        to fail. If so, quickly returns empty list. Otherwise, calls
-        try_one_generator_really.
-    """
-    source_types = []
-
-    for s in sources:
-        source_types.append (s.type ())
-
-    viable_source_types = viable_source_types_for_generator (generator)
-    
-    if source_types and viable_source_types != ['*'] and\
-           not set.intersection (source_types, viable_source_types):
-        if project.manager ().logger ().on ():
-            id = generator.id ()            
-            project.manager ().logger ().log (__name__, "generator '%s' pruned" % id)
-            project.manager ().logger ().log (__name__, "source_types" '%s' % source_types)
-            project.manager ().logger ().log (__name__, "viable_source_types '%s'" % viable_source_types)
-        
-        return []
-
-    else:
-        return try_one_generator_really (project, name, generator, target_type, properties, sources)
-
-
-def construct_types (project, name, target_types, prop_set, sources):
-    
-    result = []
-    usage_requirements = property_set.empty()
-    
-    for t in target_types:
-        r = construct (project, name, t, prop_set, sources)
-
-        if r:
-            (ur, targets) = r
-            usage_requirements = usage_requirements.add(ur)
-            result.extend(targets)
-
-    # TODO: have to introduce parameter controlling if
-    # several types can be matched and add appropriate
-    # checks 
-
-    # TODO: need to review the documentation for
-    # 'construct' to see if it should return $(source) even
-    # if nothing can be done with it. Currents docs seem to
-    # imply that, contrary to the behaviour.
-    if result:
-        return (usage_requirements, result)
-
-    else:
-        return (usage_requirements, sources)
-
-def __ensure_type (targets):
-    """ Ensures all 'targets' have types. If this is not so, exists with 
-        error.
-    """
-    for t in targets:
-        if not t.type ():
-            get_manager().errors()("target '%s' has no type" % str (t))
-
-def find_viable_generators_aux (target_type, prop_set):
-    """ Returns generators which can be used to construct target of specified type
-        with specified properties. Uses the following algorithm:
-        - iterates over requested target_type and all it's bases (in the order returned bt
-          type.all-bases.
-        - for each type find all generators that generate that type and which requirements
-          are satisfied by properties.
-        - if the set of generators is not empty, returns that set.
-        
-        Note: this algorithm explicitly ignores generators for base classes if there's
-        at least one generator for requested target_type.
-    """
-    # Select generators that can create the required target type.
-    viable_generators = []
-    initial_generators = []
-
-    import type
-
-    # Try all-type generators first. Assume they have
-    # quite specific requirements.
-    all_bases = type.all_bases(target_type)
-        
-    for t in all_bases:
-        
-        initial_generators = __type_to_generators.get(t, [])
-        
-        if initial_generators:
-            dout("there are generators for this type")
-            if t != target_type:
-                # We're here, when no generators for target-type are found,
-                # but there are some generators for a base type.
-                # We'll try to use them, but they will produce targets of
-                # base type, not of 'target-type'. So, we clone the generators
-                # and modify the list of target types.
-                generators2 = []
-                for g in initial_generators[:]:
-                    # generators.register adds generator to the list of generators
-                    # for toolsets, which is a bit strange, but should work.
-                    # That list is only used when inheriting toolset, which
-                    # should have being done before generators are run.
-                    ng = g.clone_and_change_target_type(t, target_type)
-                    generators2.append(ng)
-                    register(ng)
-                    
-                initial_generators = generators2
-            break
-    
-    for g in initial_generators:
-        dout("trying generator " + g.id()
-             + "(" + str(g.source_types()) + "->" + str(g.target_types()) + ")")
-        
-        m = g.match_rank(prop_set)
-        if m:
-            dout("  is viable")
-            viable_generators.append(g)            
-                            
-    return viable_generators
-
-def find_viable_generators (target_type, prop_set):
-    key = target_type + '.' + str (prop_set)
-
-    l = __viable_generators_cache.get (key, None)
-    if not l:
-        l = []
-
-    if not l:
-        l = find_viable_generators_aux (target_type, prop_set)
-
-        __viable_generators_cache [key] = l
-
-    viable_generators = []
-    for g in l:
-        # Avoid trying the same generator twice on different levels.
-        # TODO: is this really used?
-        if not g in __active_generators:
-            viable_generators.append (g)
-        else:
-            dout("      generator %s is active, discarding" % g.id())
-
-    # Generators which override 'all'.
-    all_overrides = []
-    
-    # Generators which are overriden
-    overriden_ids = [] 
-       
-    for g in viable_generators:
-        id = g.id ()
-        
-        this_overrides = __overrides.get (id, [])
-        
-        if this_overrides:
-            overriden_ids.extend (this_overrides)
-            if 'all' in this_overrides:
-                all_overrides.append (g)
-
-    if all_overrides:
-        viable_generators = all_overrides
-
-    result = []
-    for g in viable_generators:
-        if not g.id () in overriden_ids:
-            result.append (g)
-
-        
-    return result
-    
-def __construct_really (project, name, target_type, prop_set, sources):
-    """ Attempts to construct target by finding viable generators, running them
-        and selecting the dependency graph.
-    """
-    viable_generators = find_viable_generators (target_type, prop_set)
-                    
-    result = []
-
-    project.manager ().logger ().log (__name__, "*** %d viable generators" % len (viable_generators))
-
-    generators_that_succeeded = []
-    
-    for g in viable_generators:
-        __active_generators.append(g)        
-        r = try_one_generator (project, name, g, target_type, prop_set, sources)
-        del __active_generators[-1]
-        
-        if r:
-            generators_that_succeeded.append(g)
-            if result:
-                output = cStringIO.StringIO()
-                print >>output, "ambiguity found when searching for best transformation"
-                print >>output, "Trying to produce type '%s' from: " % (target_type)
-                for s in sources:
-                    print >>output, " - " + s.str()
-                print >>output, "Generators that succeeded:"
-                for g in generators_that_succeeded:
-                    print >>output, " - " + g.id()
-                print >>output, "First generator produced: "
-                for t in result[1:]:
-                    print >>output, " - " + str(t)
-                print >>output, "Second generator produced:"
-                for t in r[1:]:
-                    print >>output, " - " + str(t)
-                get_manager().errors()(output.getvalue())
-            else:
-                result = r;
-            
-    return result;
-
-
-def construct (project, name, target_type, prop_set, sources, top_level=False):
-    """ Attempts to create target of 'target-type' with 'properties'
-        from 'sources'. The 'sources' are treated as a collection of
-        *possible* ingridients -- i.e. it is not required to consume
-        them all. If 'multiple' is true, the rule is allowed to return
-        several targets of 'target-type'.          
-        
-        Returns a list of target. When this invocation is first instance of
-        'construct' in stack, returns only targets of requested 'target-type',
-        otherwise, returns also unused sources and additionally generated
-        targets.
-        
-        If 'top-level' is set, does not suppress generators that are already
-        used in the stack. This may be useful in cases where a generator
-        has to build a metatarget -- for example a target corresponding to
-        built tool.        
-    """
-
-    global __active_generators
-    if top_level:
-        saved_active = __active_generators
-        __active_generators = []
-
-    global __construct_stack
-    if not __construct_stack:
-        __ensure_type (sources)
-        
-    __construct_stack.append (1)
-
-    if project.manager().logger().on():
-        increase_indent ()
-        
-        dout( "*** construct " + target_type)
-        
-        for s in sources:
-            dout("    from " + str(s))
-
-        project.manager().logger().log (__name__, "    properties: ", prop_set.raw ())
-             
-    result = __construct_really(project, name, target_type, prop_set, sources)
-
-    project.manager().logger().decrease_indent()
-        
-    __construct_stack = __construct_stack [1:]
-
-    if top_level:
-        __active_generators = saved_active
-
-    return result
-