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, source, target, env, **kw):
84 for src in map(str, source):
85 my_ext = os.path.splitext(src)[1]
86 if ext and my_ext != ext:
87 raise UserError("Cannot build multiple sources with different extensions.")
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 "$FOO") as an emitter.
121 # We will look in that Environment variable for
122 # a callable to use as the actual emitter.
123 var = SCons.Util.get_environment_var(kw['emitter'])
125 raise UserError, "Supplied emitter '%s' does not appear to refer to an Environment variable" % kw['emitter']
126 kw['emitter'] = EmitterProxy(var)
128 if kw.has_key('src_builder'):
129 ret = apply(MultiStepBuilder, (), kw)
131 ret = apply(BuilderBase, (), kw)
134 ret = CompositeBuilder(ret, composite)
138 def _init_nodes(builder, env, args, tlist, slist):
139 """Initialize lists of target and source nodes with all of
140 the proper Builder information.
144 src_key = s.scanner_key() # the file suffix
145 scanner = env.get_scanner(src_key)
147 s.source_scanner = scanner
151 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
152 if t.builder is not None:
154 raise UserError, "Two different environments were specified for the same target: %s"%str(t)
155 elif t.build_args != args:
156 raise UserError, "Two different sets of build arguments were specified for the same target: %s"%str(t)
157 elif builder.scanner and builder.scanner != t.target_scanner:
158 raise UserError, "Two different scanners were specified for the same target: %s"%str(t)
161 if t.builder != builder:
162 if isinstance(t.builder, ListBuilder) and isinstance(builder, ListBuilder) and t.builder.builder == builder.builder:
163 raise UserError, "Two different target sets have a target in common: %s"%str(t)
165 raise UserError, "Two different builders (%s and %s) were specified for the same target: %s"%(t.builder.get_name(env), builder.get_name(env), str(t))
166 elif t.sources != slist:
167 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
170 t.cwd = SCons.Node.FS.default_fs.getcwd()
171 t.builder_set(builder)
175 t.target_scanner = builder.scanner
177 def _adjust_suffix(suff):
178 if suff and not suff[0] in [ '.', '$' ]:
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, **kw):
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)
203 args = { 'target':target,
207 return apply(emitter, (), args)
209 def __cmp__(self, other):
210 return cmp(self.var, other.var)
213 """Base class for Builders, objects that create output
214 nodes (files) from input nodes (files).
217 def __init__(self, name = None,
222 node_factory = SCons.Node.FS.default_fs.File,
223 target_factory = None,
224 source_factory = None,
229 self.action = SCons.Action.Action(action)
234 self.set_src_suffix(src_suffix)
236 self.target_factory = target_factory or node_factory
237 self.source_factory = source_factory or node_factory
238 self.scanner = scanner
240 self.emitter = emitter
242 def get_name(self, env):
243 """Attempts to get the name of the Builder.
245 If the Builder's name attribute is None, then we will look at
246 the BUILDERS variable of env, expecting it to be a dictionary
247 containing this Builder, and we will return the key of the
253 index = env['BUILDERS'].values().index(self)
254 return env['BUILDERS'].keys()[index]
255 except (AttributeError, KeyError, ValueError):
256 return str(self.__class__)
258 def __cmp__(self, other):
259 return cmp(self.__dict__, other.__dict__)
261 def _create_nodes(self, env, args, target = None, source = None):
262 """Create and return lists of target and source nodes.
264 def adjustixes(files, pre, suf):
268 if not SCons.Util.is_List(files):
272 if SCons.Util.is_String(f):
273 if pre and f[:len(pre)] != pre:
274 path, fn = os.path.split(os.path.normpath(f))
275 f = os.path.join(path, pre + fn)
276 # Only append a suffix if the file does not have one.
277 if suf and not os.path.splitext(f)[1]:
278 if f[-len(suf):] != suf:
283 pre = self.get_prefix(env)
284 suf = self.get_suffix(env)
285 src_suf = self.get_src_suffix(env)
287 # pass the targets and sources to the emitter as strings
288 # rather than nodes since str(node) doesn't work
289 # properly from any directory other than the top directory,
290 # and emitters are called "in" the SConscript directory:
291 tlist = adjustixes(target, pre, suf)
292 slist = adjustixes(source, None, src_suf)
294 emit_args = { 'target' : tlist,
297 emit_args.update(args)
298 target, source = apply(self.emitter, (), emit_args)
300 slist = SCons.Node.arg2nodes(adjustixes(source, None, src_suf),
303 target = map(lambda x, s=suf: os.path.splitext(str(x))[0] + s,
305 tlist = SCons.Node.arg2nodes(adjustixes(target, pre, suf),
310 def __call__(self, env, target = None, source = _null, **kw):
314 tlist, slist = self._create_nodes(env, kw, target, source)
317 _init_nodes(self, env, kw, tlist, slist)
320 _init_nodes(ListBuilder(self, env, tlist), env, kw, tlist, slist)
324 def execute(self, **kw):
325 """Execute a builder's action to create an output object.
327 return apply(self.action.execute, (), kw)
329 def get_raw_contents(self, **kw):
330 """Fetch the "contents" of the builder's action.
332 return apply(self.action.get_raw_contents, (), kw)
334 def get_contents(self, **kw):
335 """Fetch the "contents" of the builder's action
336 (for signature calculation).
338 return apply(self.action.get_contents, (), kw)
340 def src_suffixes(self, env):
341 return map(lambda x, e=env: e.subst(_adjust_suffix(x)),
344 def set_src_suffix(self, src_suffix):
347 elif not SCons.Util.is_List(src_suffix):
348 src_suffix = [ src_suffix ]
349 self.src_suffix = src_suffix
351 def get_src_suffix(self, env):
352 """Get the first src_suffix in the list of src_suffixes."""
353 ret = self.src_suffixes(env)
358 def get_suffix(self, env):
359 return env.subst(_adjust_suffix(self.suffix))
361 def get_prefix(self, env):
362 return env.subst(self.prefix)
364 def targets(self, node):
365 """Return the list of targets for this builder instance.
367 For most normal builders, this is just the supplied node.
371 class ListBuilder(SCons.Util.Proxy):
372 """A Proxy to support building an array of targets (for example,
373 foo.o and foo.h from foo.y) from a single Action execution.
376 def __init__(self, builder, env, tlist):
377 SCons.Util.Proxy.__init__(self, builder)
378 self.builder = builder
379 self.scanner = builder.scanner
382 self.multi = builder.multi
383 self.name = "ListBuilder(%s)"%builder.name
385 def execute(self, **kw):
386 if hasattr(self, 'status'):
389 # unlink all targets and make all directories
390 # before building anything
392 kw['target'] = self.tlist
393 self.status = apply(self.builder.execute, (), kw)
395 if not t is kw['target']:
399 def targets(self, node):
400 """Return the list of targets for this builder instance.
404 def __cmp__(self, other):
405 return cmp(self.__dict__, other.__dict__)
407 def get_name(self, env):
408 """Attempts to get the name of the Builder.
410 If the Builder's name attribute is None, then we will look at
411 the BUILDERS variable of env, expecting it to be a dictionary
412 containing this Builder, and we will return the key of the
415 return "ListBuilder(%s)" % self.builder.get_name(env)
417 class MultiStepBuilder(BuilderBase):
418 """This is a builder subclass that can build targets in
419 multiple steps. The src_builder parameter to the constructor
420 accepts a builder that is called to build sources supplied to
421 this builder. The targets of that first build then become
422 the sources of this builder.
424 If this builder has a src_suffix supplied, then the src_builder
425 builder is NOT invoked if the suffix of a source file matches
428 def __init__(self, src_builder,
434 node_factory = SCons.Node.FS.default_fs.File,
435 target_factory = None,
436 source_factory = None,
439 BuilderBase.__init__(self, name, action, prefix, suffix, src_suffix,
440 node_factory, target_factory, source_factory,
442 if not SCons.Util.is_List(src_builder):
443 src_builder = [ src_builder ]
444 self.src_builder = src_builder
447 def __call__(self, env, target = None, source = None, **kw):
448 slist = SCons.Node.arg2nodes(source, self.source_factory)
453 sdict = self.sdict[r]
456 self.sdict[r] = sdict
457 for bld in self.src_builder:
458 if SCons.Util.is_String(bld):
460 bld = env['BUILDERS'][bld]
463 for suf in bld.src_suffixes(env):
467 path, ext = os.path.splitext(snode.abspath)
468 if sdict.has_key(ext):
471 dictArgs = copy.copy(kw)
472 dictArgs['target'] = [path]
473 dictArgs['source'] = snode
474 dictArgs['env'] = env
475 tgt = apply(src_bld, (), dictArgs)
476 if not SCons.Util.is_List(tgt):
479 # Only supply the builder with sources it is capable
481 tgt = filter(lambda x,
482 suf=self.src_suffixes(env):
483 os.path.splitext(SCons.Util.to_String(x))[1] in \
485 final_sources.extend(tgt)
487 final_sources.append(snode)
489 dictKwArgs['target'] = target
490 dictKwArgs['source'] = final_sources
491 return apply(BuilderBase.__call__,
492 (self, env), dictKwArgs)
494 def get_src_builders(self, env):
495 """Return all the src_builders for this Builder.
497 This is essentially a recursive descent of the src_builder "tree."
500 for bld in self.src_builder:
501 if SCons.Util.is_String(bld):
502 # All Environments should have a BUILDERS
503 # variable, so no need to check for it.
505 bld = env['BUILDERS'][bld]
511 def src_suffixes(self, env):
512 """Return a list of the src_suffix attributes for all
513 src_builders of this Builder.
515 suffixes = BuilderBase.src_suffixes(self, env)
516 for builder in self.get_src_builders(env):
517 suffixes.extend(builder.src_suffixes(env))
520 class CompositeBuilder(SCons.Util.Proxy):
521 """A Builder Proxy whose main purpose is to always have
522 a DictCmdGenerator as its action, and to provide access
523 to the DictCmdGenerator's add_action() method.
526 def __init__(self, builder, cmdgen):
527 SCons.Util.Proxy.__init__(self, builder)
529 # cmdgen should always be an instance of DictCmdGenerator.
531 self.builder = builder
533 def add_action(self, suffix, action):
534 self.cmdgen.add_action(suffix, action)
535 self.set_src_suffix(self.cmdgen.src_suffixes())
537 def __cmp__(self, other):
538 return cmp(self.__dict__, other.__dict__)