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.
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__"
49 from SCons.Errors import InternalError, UserError
62 class DictCmdGenerator:
63 """This is a callable class that can be used as a
64 command generator function. It holds on to a dictionary
65 mapping file suffixes to Actions. It uses that dictionary
66 to return the proper action based on the file suffix of
69 def __init__(self, action_dict):
70 self.action_dict = action_dict
72 def src_suffixes(self):
73 return self.action_dict.keys()
75 def add_action(self, suffix, action):
76 """Add a suffix-action pair to the mapping.
78 self.action_dict[suffix] = action
80 def __call__(self, target, source, env, for_signature):
82 for src in map(str, source):
83 my_ext = SCons.Util.splitext(src)[1]
84 if ext and my_ext != ext:
85 raise UserError("Cannot build multiple sources with different extensions: %s, %s" % (ext, my_ext))
89 raise UserError("Cannot deduce file extension from source files: %s" % repr(map(str, source)))
91 # XXX Do we need to perform Environment substitution
92 # on the keys of action_dict before looking it up?
93 return self.action_dict[ext]
95 raise UserError("Don't know how to build a file with suffix %s." % ext)
96 def __cmp__(self, other):
97 return cmp(self.action_dict, other.action_dict)
100 """A factory for builder objects."""
102 if kw.has_key('generator'):
103 if kw.has_key('action'):
104 raise UserError, "You must not specify both an action and a generator."
105 kw['action'] = SCons.Action.CommandGenerator(kw['generator'])
107 elif kw.has_key('action') and SCons.Util.is_Dict(kw['action']):
108 composite = DictCmdGenerator(kw['action'])
109 kw['action'] = SCons.Action.CommandGenerator(composite)
110 kw['src_suffix'] = composite.src_suffixes()
112 if kw.has_key('emitter') and \
113 SCons.Util.is_String(kw['emitter']):
114 # This allows users to pass in an Environment
115 # variable reference (like "$FOO") as an emitter.
116 # We will look in that Environment variable for
117 # a callable to use as the actual emitter.
118 var = SCons.Util.get_environment_var(kw['emitter'])
120 raise UserError, "Supplied emitter '%s' does not appear to refer to an Environment variable" % kw['emitter']
121 kw['emitter'] = EmitterProxy(var)
123 if kw.has_key('src_builder'):
124 ret = apply(MultiStepBuilder, (), kw)
126 ret = apply(BuilderBase, (), kw)
129 ret = CompositeBuilder(ret, composite)
133 def _init_nodes(builder, env, overrides, tlist, slist):
134 """Initialize lists of target and source nodes with all of
135 the proper Builder information.
139 src_key = s.scanner_key() # the file suffix
140 scanner = env.get_scanner(src_key)
142 s.source_scanner = scanner
146 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
149 raise UserError, "Two different environments were specified for the same target: %s"%str(t)
150 elif t.overrides != overrides:
151 raise UserError, "Two different sets of overrides were specified for the same target: %s"%str(t)
152 elif builder.scanner and builder.scanner != t.target_scanner:
153 raise UserError, "Two different scanners were specified for the same target: %s"%str(t)
156 if t.builder != builder:
157 if isinstance(t.builder, ListBuilder) and isinstance(builder, ListBuilder) and t.builder.builder == builder.builder:
158 raise UserError, "Two different target sets have a target in common: %s"%str(t)
160 raise UserError, "Two different builders (%s and %s) were specified for the same target: %s"%(t.builder.get_name(env), builder.get_name(env), str(t))
161 elif t.sources != slist:
162 raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
164 t.overrides = overrides
165 t.cwd = SCons.Node.FS.default_fs.getcwd()
166 t.builder_set(builder)
170 t.target_scanner = builder.scanner
172 def _adjust_suffix(suff):
173 if suff and not suff[0] in [ '.', '$' ]:
178 """This is a callable class that can act as a
179 Builder emitter. It holds on to a string that
180 is a key into an Environment dictionary, and will
181 look there at actual build time to see if it holds
182 a callable. If so, we will call that as the actual
184 def __init__(self, var):
185 self.var = SCons.Util.to_String(var)
187 def __call__(self, target, source, env):
190 # Recursively substitute the variable.
191 # We can't use env.subst() because it deals only
192 # in strings. Maybe we should change that?
193 while SCons.Util.is_String(emitter) and \
194 env.has_key(emitter):
195 emitter = env[emitter]
196 if not callable(emitter):
197 return (target, source)
199 return emitter(target, source, env)
201 def __cmp__(self, other):
202 return cmp(self.var, other.var)
205 """Base class for Builders, objects that create output
206 nodes (files) from input nodes (files).
209 def __init__(self, action = None,
213 node_factory = SCons.Node.FS.default_fs.File,
214 target_factory = None,
215 source_factory = None,
221 self.action = SCons.Action.Action(action)
226 self.overrides = overrides
228 self.set_src_suffix(src_suffix)
230 self.target_factory = target_factory or node_factory
231 self.source_factory = source_factory or node_factory
232 self.scanner = scanner
234 self.emitter = emitter
236 def __nonzero__(self):
237 raise InternalError, "Do not test for the Node.builder attribute directly; use Node.has_builder() instead"
239 def get_name(self, env):
240 """Attempts to get the name of the Builder.
242 Look at the BUILDERS variable of env, expecting it to be a
243 dictionary containing this Builder, and return the key of the
247 index = env['BUILDERS'].values().index(self)
248 return env['BUILDERS'].keys()[index]
249 except (AttributeError, KeyError, ValueError):
250 return str(self.__class__)
252 def __cmp__(self, other):
253 return cmp(self.__dict__, other.__dict__)
255 def _create_nodes(self, env, overrides, target = None, source = None):
256 """Create and return lists of target and source nodes.
258 def adjustixes(files, pre, suf):
262 if not SCons.Util.is_List(files):
266 if SCons.Util.is_String(f):
267 if pre and f[:len(pre)] != pre:
268 path, fn = os.path.split(os.path.normpath(f))
269 f = os.path.join(path, pre + fn)
270 # Only append a suffix if the file does not have one.
271 if suf and not SCons.Util.splitext(f)[1]:
272 if f[-len(suf):] != suf:
277 env = env.Override(overrides)
279 pre = self.get_prefix(env)
280 suf = self.get_suffix(env)
281 src_suf = self.get_src_suffix(env)
283 source = adjustixes(source, None, src_suf)
286 if isinstance(s, SCons.Node.Node):
287 s = os.path.split(str(s))[1]
288 target = [ pre + os.path.splitext(s)[0] + suf ]
290 target = adjustixes(target, pre, suf)
293 # pass the targets and sources to the emitter as strings
294 # rather than nodes since str(node) doesn't work
295 # properly from any directory other than the top directory,
296 # and emitters are called "in" the SConscript directory:
297 target, source = self.emitter(target=target, source=source, env=env)
299 slist = SCons.Node.arg2nodes(source, self.source_factory)
300 tlist = SCons.Node.arg2nodes(target, self.target_factory)
304 def __call__(self, env, target = None, source = _null, **overrides):
308 tlist, slist = self._create_nodes(env, overrides, target, source)
311 _init_nodes(self, env, overrides, tlist, slist)
314 _init_nodes(ListBuilder(self, env, tlist), env, overrides, tlist, slist)
318 def get_actions(self):
319 return self.action.get_actions()
321 def get_raw_contents(self, target, source, env):
322 """Fetch the "contents" of the builder's action.
324 return self.action.get_raw_contents(target, source, env)
326 def get_contents(self, target, source, env):
327 """Fetch the "contents" of the builder's action
328 (for signature calculation).
330 return self.action.get_contents(target, source, env)
332 def src_suffixes(self, env):
333 return map(lambda x, e=env: e.subst(_adjust_suffix(x)),
336 def set_src_suffix(self, src_suffix):
339 elif not SCons.Util.is_List(src_suffix):
340 src_suffix = [ src_suffix ]
341 self.src_suffix = src_suffix
343 def get_src_suffix(self, env):
344 """Get the first src_suffix in the list of src_suffixes."""
345 ret = self.src_suffixes(env)
350 def get_suffix(self, env):
351 return env.subst(_adjust_suffix(self.suffix))
353 def get_prefix(self, env):
354 return env.subst(self.prefix)
356 def targets(self, node):
357 """Return the list of targets for this builder instance.
359 For most normal builders, this is just the supplied node.
363 class ListBuilder(SCons.Util.Proxy):
364 """A Proxy to support building an array of targets (for example,
365 foo.o and foo.h from foo.y) from a single Action execution.
368 def __init__(self, builder, env, tlist):
369 SCons.Util.Proxy.__init__(self, builder)
370 self.builder = builder
371 self.scanner = builder.scanner
374 self.multi = builder.multi
376 def targets(self, node):
377 """Return the list of targets for this builder instance.
381 def __cmp__(self, other):
382 return cmp(self.__dict__, other.__dict__)
384 def get_name(self, env):
385 """Attempts to get the name of the Builder."""
387 return "ListBuilder(%s)" % self.builder.get_name(env)
389 class MultiStepBuilder(BuilderBase):
390 """This is a builder subclass that can build targets in
391 multiple steps. The src_builder parameter to the constructor
392 accepts a builder that is called to build sources supplied to
393 this builder. The targets of that first build then become
394 the sources of this builder.
396 If this builder has a src_suffix supplied, then the src_builder
397 builder is NOT invoked if the suffix of a source file matches
400 def __init__(self, src_builder,
405 node_factory = SCons.Node.FS.default_fs.File,
406 target_factory = None,
407 source_factory = None,
410 BuilderBase.__init__(self, action, prefix, suffix, src_suffix,
411 node_factory, target_factory, source_factory,
413 if not SCons.Util.is_List(src_builder):
414 src_builder = [ src_builder ]
415 self.src_builder = src_builder
417 self.cached_src_suffixes = {} # source suffixes keyed on id(env)
419 def __call__(self, env, target = None, source = _null, **kw):
424 slist = SCons.Node.arg2nodes(source, self.source_factory)
428 sdict = self.sdict[id(env)]
431 self.sdict[id(env)] = sdict
432 for bld in self.src_builder:
433 if SCons.Util.is_String(bld):
435 bld = env['BUILDERS'][bld]
438 for suf in bld.src_suffixes(env):
441 src_suffixes = self.src_suffixes(env)
444 path, ext = SCons.Util.splitext(snode.abspath)
445 if sdict.has_key(ext):
447 tgt = apply(src_bld, (env, path, snode), kw)
448 # Only supply the builder with sources it is capable
450 if SCons.Util.is_List(tgt):
451 tgt = filter(lambda x, suf=src_suffixes:
452 SCons.Util.splitext(SCons.Util.to_String(x))[1] in suf,
454 if not SCons.Util.is_List(tgt):
455 final_sources.append(tgt)
457 final_sources.extend(tgt)
459 final_sources.append(snode)
461 return apply(BuilderBase.__call__,
462 (self, env, target, final_sources), kw)
464 def get_src_builders(self, env):
465 """Return all the src_builders for this Builder.
467 This is essentially a recursive descent of the src_builder "tree."
470 for bld in self.src_builder:
471 if SCons.Util.is_String(bld):
472 # All Environments should have a BUILDERS
473 # variable, so no need to check for it.
475 bld = env['BUILDERS'][bld]
481 def src_suffixes(self, env):
482 """Return a list of the src_suffix attributes for all
483 src_builders of this Builder.
486 return self.cached_src_suffixes[id(env)]
488 suffixes = BuilderBase.src_suffixes(self, env)
489 for builder in self.get_src_builders(env):
490 suffixes.extend(builder.src_suffixes(env))
491 self.cached_src_suffixes[id(env)] = suffixes
494 class CompositeBuilder(SCons.Util.Proxy):
495 """A Builder Proxy whose main purpose is to always have
496 a DictCmdGenerator as its action, and to provide access
497 to the DictCmdGenerator's add_action() method.
500 def __init__(self, builder, cmdgen):
501 SCons.Util.Proxy.__init__(self, builder)
503 # cmdgen should always be an instance of DictCmdGenerator.
505 self.builder = builder
507 def add_action(self, suffix, action):
508 self.cmdgen.add_action(suffix, action)
509 self.set_src_suffix(self.cmdgen.src_suffixes())
511 def __cmp__(self, other):
512 return cmp(self.__dict__, other.__dict__)