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 "$FOO") as an emitter.
121 # We will look in that Environment variable for
122 # a callable to use as the actual emitter.
123 var = SCons.Util.get_environment_var(kw['emitter'])
125 raise UserError, "Supplied emitter '%s' does not appear to refer to an Environment variable" % kw['emitter']
126 kw['emitter'] = EmitterProxy(var)
128 if kw.has_key('src_builder'):
129 ret = apply(MultiStepBuilder, (), kw)
131 ret = apply(BuilderBase, (), kw)
134 ret = CompositeBuilder(ret, composite)
138 def _init_nodes(builder, env, overrides, tlist, slist):
139 """Initialize lists of target and source nodes with all of
140 the proper Builder information.
144 src_key = s.scanner_key() # the file suffix
145 scanner = env.get_scanner(src_key)
147 s.source_scanner = scanner
151 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
152 if t.builder is not None:
154 raise UserError, "Two different environments were specified for the same target: %s"%str(t)
155 elif t.overrides != overrides:
156 raise UserError, "Two different sets of overrides were specified for the same target: %s"%str(t)
157 elif builder.scanner and builder.scanner != t.target_scanner:
158 raise UserError, "Two different scanners were specified for the same target: %s"%str(t)
161 if t.builder != builder:
162 if isinstance(t.builder, ListBuilder) and isinstance(builder, ListBuilder) and t.builder.builder == builder.builder:
163 raise UserError, "Two different target sets have a target in common: %s"%str(t)
165 raise UserError, "Two different builders (%s and %s) were specified for the same target: %s"%(t.builder.get_name(env), builder.get_name(env), str(t))
166 elif t.sources != slist:
167 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
169 t.overrides = overrides
170 t.cwd = SCons.Node.FS.default_fs.getcwd()
171 t.builder_set(builder)
175 t.target_scanner = builder.scanner
177 def _adjust_suffix(suff):
178 if suff and not suff[0] in [ '.', '$' ]:
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)
288 target = map(lambda x, s=suf:
289 os.path.splitext(os.path.split(str(x))[1])[0] + s,
292 target = adjustixes(target, pre, suf)
295 # pass the targets and sources to the emitter as strings
296 # rather than nodes since str(node) doesn't work
297 # properly from any directory other than the top directory,
298 # and emitters are called "in" the SConscript directory:
299 target, source = self.emitter(target=target, source=source, env=env)
301 slist = SCons.Node.arg2nodes(source, self.source_factory)
302 tlist = SCons.Node.arg2nodes(target, self.target_factory)
306 def __call__(self, env, target = None, source = _null, **overrides):
310 tlist, slist = self._create_nodes(env, overrides, target, source)
313 _init_nodes(self, env, overrides, tlist, slist)
316 _init_nodes(ListBuilder(self, env, tlist), env, overrides, tlist, slist)
320 def get_actions(self):
321 return self.action.get_actions()
323 def get_raw_contents(self, target, source, env):
324 """Fetch the "contents" of the builder's action.
326 return self.action.get_raw_contents(target, source, env)
328 def get_contents(self, target, source, env):
329 """Fetch the "contents" of the builder's action
330 (for signature calculation).
332 return self.action.get_contents(target, source, env)
334 def src_suffixes(self, env):
335 return map(lambda x, e=env: e.subst(_adjust_suffix(x)),
338 def set_src_suffix(self, src_suffix):
341 elif not SCons.Util.is_List(src_suffix):
342 src_suffix = [ src_suffix ]
343 self.src_suffix = src_suffix
345 def get_src_suffix(self, env):
346 """Get the first src_suffix in the list of src_suffixes."""
347 ret = self.src_suffixes(env)
352 def get_suffix(self, env):
353 return env.subst(_adjust_suffix(self.suffix))
355 def get_prefix(self, env):
356 return env.subst(self.prefix)
358 def targets(self, node):
359 """Return the list of targets for this builder instance.
361 For most normal builders, this is just the supplied node.
365 class ListBuilder(SCons.Util.Proxy):
366 """A Proxy to support building an array of targets (for example,
367 foo.o and foo.h from foo.y) from a single Action execution.
370 def __init__(self, builder, env, tlist):
371 SCons.Util.Proxy.__init__(self, builder)
372 self.builder = builder
373 self.scanner = builder.scanner
376 self.multi = builder.multi
377 self.name = "ListBuilder(%s)"%builder.name
379 def targets(self, node):
380 """Return the list of targets for this builder instance.
384 def __cmp__(self, other):
385 return cmp(self.__dict__, other.__dict__)
387 def get_name(self, env):
388 """Attempts to get the name of the Builder.
390 If the Builder's name attribute is None, then we will look at
391 the BUILDERS variable of env, expecting it to be a dictionary
392 containing this Builder, and we will return the key of the
395 return "ListBuilder(%s)" % self.builder.get_name(env)
397 class MultiStepBuilder(BuilderBase):
398 """This is a builder subclass that can build targets in
399 multiple steps. The src_builder parameter to the constructor
400 accepts a builder that is called to build sources supplied to
401 this builder. The targets of that first build then become
402 the sources of this builder.
404 If this builder has a src_suffix supplied, then the src_builder
405 builder is NOT invoked if the suffix of a source file matches
408 def __init__(self, src_builder,
414 node_factory = SCons.Node.FS.default_fs.File,
415 target_factory = None,
416 source_factory = None,
419 BuilderBase.__init__(self, name, action, prefix, suffix, src_suffix,
420 node_factory, target_factory, source_factory,
422 if not SCons.Util.is_List(src_builder):
423 src_builder = [ src_builder ]
424 self.src_builder = src_builder
426 self.cached_src_suffixes = {} # source suffixes keyed on id(env)
428 def __call__(self, env, target = None, source = None, **kw):
429 slist = SCons.Node.arg2nodes(source, self.source_factory)
433 sdict = self.sdict[id(env)]
436 self.sdict[id(env)] = sdict
437 for bld in self.src_builder:
438 if SCons.Util.is_String(bld):
440 bld = env['BUILDERS'][bld]
443 for suf in bld.src_suffixes(env):
446 src_suffixes = self.src_suffixes(env)
449 path, ext = SCons.Util.splitext(snode.abspath)
450 if sdict.has_key(ext):
452 tgt = apply(src_bld, (env, path, snode), kw)
453 # Only supply the builder with sources it is capable
455 if SCons.Util.is_List(tgt):
456 tgt = filter(lambda x, suf=src_suffixes:
457 SCons.Util.splitext(SCons.Util.to_String(x))[1] in suf,
459 if not SCons.Util.is_List(tgt):
460 final_sources.append(tgt)
462 final_sources.extend(tgt)
464 final_sources.append(snode)
466 return apply(BuilderBase.__call__,
467 (self, env, target, final_sources), kw)
469 def get_src_builders(self, env):
470 """Return all the src_builders for this Builder.
472 This is essentially a recursive descent of the src_builder "tree."
475 for bld in self.src_builder:
476 if SCons.Util.is_String(bld):
477 # All Environments should have a BUILDERS
478 # variable, so no need to check for it.
480 bld = env['BUILDERS'][bld]
486 def src_suffixes(self, env):
487 """Return a list of the src_suffix attributes for all
488 src_builders of this Builder.
491 return self.cached_src_suffixes[id(env)]
493 suffixes = BuilderBase.src_suffixes(self, env)
494 for builder in self.get_src_builders(env):
495 suffixes.extend(builder.src_suffixes(env))
496 self.cached_src_suffixes[id(env)] = suffixes
499 class CompositeBuilder(SCons.Util.Proxy):
500 """A Builder Proxy whose main purpose is to always have
501 a DictCmdGenerator as its action, and to provide access
502 to the DictCmdGenerator's add_action() method.
505 def __init__(self, builder, cmdgen):
506 SCons.Util.Proxy.__init__(self, builder)
508 # cmdgen should always be an instance of DictCmdGenerator.
510 self.builder = builder
512 def add_action(self, suffix, action):
513 self.cmdgen.add_action(suffix, action)
514 self.set_src_suffix(self.cmdgen.src_suffixes())
516 def __cmp__(self, other):
517 return cmp(self.__dict__, other.__dict__)