3 Builder object subsystem.
5 A Builder object is a callable that encapsulates information about how
6 to execute actions to create a Node (file) from other Nodes (files), and
7 how to create those dependencies for tracking.
9 The main entry point here is the Builder() factory method. This
10 provides a procedural interface that creates the right underlying
11 Builder object based on the keyword arguments supplied and the types of
14 The goal is for this external interface to be simple enough that the
15 vast majority of users can create new Builders as necessary to support
16 building new types of files in their configurations, without having to
17 dive any deeper into this subsystem.
22 # Copyright (c) 2001, 2002 Steven Knight
24 # Permission is hereby granted, free of charge, to any person obtaining
25 # a copy of this software and associated documentation files (the
26 # "Software"), to deal in the Software without restriction, including
27 # without limitation the rights to use, copy, modify, merge, publish,
28 # distribute, sublicense, and/or sell copies of the Software, and to
29 # permit persons to whom the Software is furnished to do so, subject to
30 # the following conditions:
32 # The above copyright notice and this permission notice shall be included
33 # in all copies or substantial portions of the Software.
35 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
36 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
37 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
38 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
39 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
40 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
41 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
44 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
51 from SCons.Errors import UserError
64 class DictCmdGenerator:
65 """This is a callable class that can be used as a
66 command generator function. It holds on to a dictionary
67 mapping file suffixes to Actions. It uses that dictionary
68 to return the proper action based on the file suffix of
71 def __init__(self, action_dict):
72 self.action_dict = action_dict
74 def src_suffixes(self):
75 return self.action_dict.keys()
77 def add_action(self, suffix, action):
78 """Add a suffix-action pair to the mapping.
80 self.action_dict[suffix] = action
82 def __call__(self, target, source, env, for_signature):
84 for src in map(str, source):
85 my_ext = SCons.Util.splitext(src)[1]
86 if ext and my_ext != ext:
87 raise UserError("Cannot build multiple sources with different extensions: %s, %s" % (ext, my_ext))
91 raise UserError("Cannot deduce file extension from source files: %s" % repr(map(str, source)))
93 # XXX Do we need to perform Environment substitution
94 # on the keys of action_dict before looking it up?
95 return self.action_dict[ext]
97 raise UserError("Don't know how to build a file with suffix %s." % ext)
98 def __cmp__(self, other):
99 return cmp(self.action_dict, other.action_dict)
102 """A factory for builder objects."""
104 if kw.has_key('name'):
105 SCons.Warnings.warn(SCons.Warnings.DeprecatedWarning,
106 "The use of the 'name' parameter to Builder() is deprecated.")
107 if kw.has_key('generator'):
108 if kw.has_key('action'):
109 raise UserError, "You must not specify both an action and a generator."
110 kw['action'] = SCons.Action.CommandGenerator(kw['generator'])
112 elif kw.has_key('action') and SCons.Util.is_Dict(kw['action']):
113 composite = DictCmdGenerator(kw['action'])
114 kw['action'] = SCons.Action.CommandGenerator(composite)
115 kw['src_suffix'] = composite.src_suffixes()
117 if kw.has_key('emitter') and \
118 SCons.Util.is_String(kw['emitter']):
119 # This allows users to pass in an Environment
120 # variable reference (like "$FOO") as an emitter.
121 # We will look in that Environment variable for
122 # a callable to use as the actual emitter.
123 var = SCons.Util.get_environment_var(kw['emitter'])
125 raise UserError, "Supplied emitter '%s' does not appear to refer to an Environment variable" % kw['emitter']
126 kw['emitter'] = EmitterProxy(var)
128 if kw.has_key('src_builder'):
129 ret = apply(MultiStepBuilder, (), kw)
131 ret = apply(BuilderBase, (), kw)
134 ret = CompositeBuilder(ret, composite)
138 def _init_nodes(builder, env, overrides, tlist, slist):
139 """Initialize lists of target and source nodes with all of
140 the proper Builder information.
144 src_key = s.scanner_key() # the file suffix
145 scanner = env.get_scanner(src_key)
147 s.source_scanner = scanner
151 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
154 raise UserError, "Two different environments were specified for the same target: %s"%str(t)
155 elif t.overrides != overrides:
156 raise UserError, "Two different sets of overrides were specified for the same target: %s"%str(t)
157 elif builder.scanner and builder.scanner != t.target_scanner:
158 raise UserError, "Two different scanners were specified for the same target: %s"%str(t)
161 if t.builder != builder:
162 if isinstance(t.builder, ListBuilder) and isinstance(builder, ListBuilder) and t.builder.builder == builder.builder:
163 raise UserError, "Two different target sets have a target in common: %s"%str(t)
165 raise UserError, "Two different builders (%s and %s) were specified for the same target: %s"%(t.builder.get_name(env), builder.get_name(env), str(t))
166 elif t.sources != slist:
167 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
169 t.overrides = overrides
170 t.cwd = SCons.Node.FS.default_fs.getcwd()
171 t.builder_set(builder)
175 t.target_scanner = builder.scanner
177 def _adjust_suffix(suff):
178 if suff and not suff[0] in [ '.', '$' ]:
183 """This is a callable class that can act as a
184 Builder emitter. It holds on to a string that
185 is a key into an Environment dictionary, and will
186 look there at actual build time to see if it holds
187 a callable. If so, we will call that as the actual
189 def __init__(self, var):
190 self.var = SCons.Util.to_String(var)
192 def __call__(self, target, source, env):
195 # Recursively substitute the variable.
196 # We can't use env.subst() because it deals only
197 # in strings. Maybe we should change that?
198 while SCons.Util.is_String(emitter) and \
199 env.has_key(emitter):
200 emitter = env[emitter]
201 if not callable(emitter):
202 return (target, source)
204 return emitter(target, source, env)
206 def __cmp__(self, other):
207 return cmp(self.var, other.var)
210 """Base class for Builders, objects that create output
211 nodes (files) from input nodes (files).
214 def __init__(self, name = None,
219 node_factory = SCons.Node.FS.default_fs.File,
220 target_factory = None,
221 source_factory = None,
226 self.action = SCons.Action.Action(action)
231 self.set_src_suffix(src_suffix)
233 self.target_factory = target_factory or node_factory
234 self.source_factory = source_factory or node_factory
235 self.scanner = scanner
237 self.emitter = emitter
239 def get_name(self, env):
240 """Attempts to get the name of the Builder.
242 If the Builder's name attribute is None, then we will look at
243 the BUILDERS variable of env, expecting it to be a dictionary
244 containing this Builder, and we will return the key of the
250 index = env['BUILDERS'].values().index(self)
251 return env['BUILDERS'].keys()[index]
252 except (AttributeError, KeyError, ValueError):
253 return str(self.__class__)
255 def __cmp__(self, other):
256 return cmp(self.__dict__, other.__dict__)
258 def _create_nodes(self, env, overrides, target = None, source = None):
259 """Create and return lists of target and source nodes.
261 def adjustixes(files, pre, suf):
265 if not SCons.Util.is_List(files):
269 if SCons.Util.is_String(f):
270 if pre and f[:len(pre)] != pre:
271 path, fn = os.path.split(os.path.normpath(f))
272 f = os.path.join(path, pre + fn)
273 # Only append a suffix if the file does not have one.
274 if suf and not SCons.Util.splitext(f)[1]:
275 if f[-len(suf):] != suf:
280 env = env.Override(overrides)
282 pre = self.get_prefix(env)
283 suf = self.get_suffix(env)
284 src_suf = self.get_src_suffix(env)
286 source = adjustixes(source, None, src_suf)
289 if isinstance(s, SCons.Node.Node):
290 s = os.path.split(str(s))[1]
291 target = [ os.path.splitext(s)[0] + suf ]
293 target = adjustixes(target, pre, suf)
296 # pass the targets and sources to the emitter as strings
297 # rather than nodes since str(node) doesn't work
298 # properly from any directory other than the top directory,
299 # and emitters are called "in" the SConscript directory:
300 target, source = self.emitter(target=target, source=source, env=env)
302 slist = SCons.Node.arg2nodes(source, self.source_factory)
303 tlist = SCons.Node.arg2nodes(target, self.target_factory)
307 def __call__(self, env, target = None, source = _null, **overrides):
311 tlist, slist = self._create_nodes(env, overrides, target, source)
314 _init_nodes(self, env, overrides, tlist, slist)
317 _init_nodes(ListBuilder(self, env, tlist), env, overrides, tlist, slist)
321 def get_actions(self):
322 return self.action.get_actions()
324 def get_raw_contents(self, target, source, env):
325 """Fetch the "contents" of the builder's action.
327 return self.action.get_raw_contents(target, source, env)
329 def get_contents(self, target, source, env):
330 """Fetch the "contents" of the builder's action
331 (for signature calculation).
333 return self.action.get_contents(target, source, env)
335 def src_suffixes(self, env):
336 return map(lambda x, e=env: e.subst(_adjust_suffix(x)),
339 def set_src_suffix(self, src_suffix):
342 elif not SCons.Util.is_List(src_suffix):
343 src_suffix = [ src_suffix ]
344 self.src_suffix = src_suffix
346 def get_src_suffix(self, env):
347 """Get the first src_suffix in the list of src_suffixes."""
348 ret = self.src_suffixes(env)
353 def get_suffix(self, env):
354 return env.subst(_adjust_suffix(self.suffix))
356 def get_prefix(self, env):
357 return env.subst(self.prefix)
359 def targets(self, node):
360 """Return the list of targets for this builder instance.
362 For most normal builders, this is just the supplied node.
366 class ListBuilder(SCons.Util.Proxy):
367 """A Proxy to support building an array of targets (for example,
368 foo.o and foo.h from foo.y) from a single Action execution.
371 def __init__(self, builder, env, tlist):
372 SCons.Util.Proxy.__init__(self, builder)
373 self.builder = builder
374 self.scanner = builder.scanner
377 self.multi = builder.multi
378 self.name = "ListBuilder(%s)"%builder.name
380 def targets(self, node):
381 """Return the list of targets for this builder instance.
385 def __cmp__(self, other):
386 return cmp(self.__dict__, other.__dict__)
388 def get_name(self, env):
389 """Attempts to get the name of the Builder.
391 If the Builder's name attribute is None, then we will look at
392 the BUILDERS variable of env, expecting it to be a dictionary
393 containing this Builder, and we will return the key of the
396 return "ListBuilder(%s)" % self.builder.get_name(env)
398 class MultiStepBuilder(BuilderBase):
399 """This is a builder subclass that can build targets in
400 multiple steps. The src_builder parameter to the constructor
401 accepts a builder that is called to build sources supplied to
402 this builder. The targets of that first build then become
403 the sources of this builder.
405 If this builder has a src_suffix supplied, then the src_builder
406 builder is NOT invoked if the suffix of a source file matches
409 def __init__(self, src_builder,
415 node_factory = SCons.Node.FS.default_fs.File,
416 target_factory = None,
417 source_factory = None,
420 BuilderBase.__init__(self, name, action, prefix, suffix, src_suffix,
421 node_factory, target_factory, source_factory,
423 if not SCons.Util.is_List(src_builder):
424 src_builder = [ src_builder ]
425 self.src_builder = src_builder
427 self.cached_src_suffixes = {} # source suffixes keyed on id(env)
429 def __call__(self, env, target = None, source = _null, **kw):
434 slist = SCons.Node.arg2nodes(source, self.source_factory)
438 sdict = self.sdict[id(env)]
441 self.sdict[id(env)] = sdict
442 for bld in self.src_builder:
443 if SCons.Util.is_String(bld):
445 bld = env['BUILDERS'][bld]
448 for suf in bld.src_suffixes(env):
451 src_suffixes = self.src_suffixes(env)
454 path, ext = SCons.Util.splitext(snode.abspath)
455 if sdict.has_key(ext):
457 tgt = apply(src_bld, (env, path, snode), kw)
458 # Only supply the builder with sources it is capable
460 if SCons.Util.is_List(tgt):
461 tgt = filter(lambda x, suf=src_suffixes:
462 SCons.Util.splitext(SCons.Util.to_String(x))[1] in suf,
464 if not SCons.Util.is_List(tgt):
465 final_sources.append(tgt)
467 final_sources.extend(tgt)
469 final_sources.append(snode)
471 return apply(BuilderBase.__call__,
472 (self, env, target, final_sources), kw)
474 def get_src_builders(self, env):
475 """Return all the src_builders for this Builder.
477 This is essentially a recursive descent of the src_builder "tree."
480 for bld in self.src_builder:
481 if SCons.Util.is_String(bld):
482 # All Environments should have a BUILDERS
483 # variable, so no need to check for it.
485 bld = env['BUILDERS'][bld]
491 def src_suffixes(self, env):
492 """Return a list of the src_suffix attributes for all
493 src_builders of this Builder.
496 return self.cached_src_suffixes[id(env)]
498 suffixes = BuilderBase.src_suffixes(self, env)
499 for builder in self.get_src_builders(env):
500 suffixes.extend(builder.src_suffixes(env))
501 self.cached_src_suffixes[id(env)] = suffixes
504 class CompositeBuilder(SCons.Util.Proxy):
505 """A Builder Proxy whose main purpose is to always have
506 a DictCmdGenerator as its action, and to provide access
507 to the DictCmdGenerator's add_action() method.
510 def __init__(self, builder, cmdgen):
511 SCons.Util.Proxy.__init__(self, builder)
513 # cmdgen should always be an instance of DictCmdGenerator.
515 self.builder = builder
517 def add_action(self, suffix, action):
518 self.cmdgen.add_action(suffix, action)
519 self.set_src_suffix(self.cmdgen.src_suffixes())
521 def __cmp__(self, other):
522 return cmp(self.__dict__, other.__dict__)