Source code for waflib.Task

#!/usr/bin/env python
# encoding: utf-8
# Thomas Nagy, 2005-2018 (ita)

Tasks represent atomic operations such as processes.

import os, re, sys, tempfile, traceback
from waflib import Utils, Logs, Errors

# task states
"""The task was not executed yet"""

"""The task has been executed but the files have not been created"""

"""The task execution returned a non-zero exit status"""

"""An exception occurred in the task execution"""

"""A dependency for the task is missing so it was cancelled"""

"""The task did not have to be executed"""

"""The task was successfully executed"""

"""The task is not ready to be executed"""

SKIP_ME = -2
"""The task does not need to be executed"""

RUN_ME = -3
"""The task must be executed"""

"""The task cannot be executed because of a dependency problem"""

def f(tsk):
	env = tsk.env
	gen = tsk.generator
	bld = gen.bld
	cwdx = tsk.get_cwd()
	p = env.get_flat
	def to_list(xx):
		if isinstance(xx, str): return [xx]
		return xx
	tsk.last_cmd = cmd = \'\'\' %s \'\'\' % s
	return tsk.exec_command(cmd, cwd=cwdx, env=env.env or None)

def f(tsk):
	env = tsk.env
	gen = tsk.generator
	bld = gen.bld
	cwdx = tsk.get_cwd()
	def to_list(xx):
		if isinstance(xx, str): return [xx]
		return xx
	def merge(lst1, lst2):
		if lst1 and lst2:
			return lst1[:-1] + [lst1[-1] + lst2[0]] + lst2[1:]
		return lst1 + lst2
	lst = []
	if '' in lst:
		lst = [x for x in lst if x]
	tsk.last_cmd = lst
	return tsk.exec_command(lst, cwd=cwdx, env=env.env or None)

def f(tsk):
	sig = tsk.generator.bld.hash_env_vars(tsk.env, tsk.vars)
	env = tsk.env
	gen = tsk.generator
	bld = gen.bld
	cwdx = tsk.get_cwd()
	p = env.get_flat
	buf = []

classes = {}
The metaclass :py:class:`waflib.Task.store_task_type` stores all class tasks
created by user scripts or Waf tools to this dict. It maps class names to class objects.

[docs]class store_task_type(type): """ Metaclass: store the task classes into the dict pointed by the class attribute 'register' which defaults to :py:const:`waflib.Task.classes`, The attribute 'run_str' is compiled into a method 'run' bound to the task class. """ def __init__(cls, name, bases, dict): super(store_task_type, cls).__init__(name, bases, dict) name = cls.__name__ if name != 'evil' and name != 'Task': if getattr(cls, 'run_str', None): # if a string is provided, convert it to a method (f, dvars) = compile_fun(cls.run_str, cls.hcode = Utils.h_cmd(cls.run_str) cls.orig_run_str = cls.run_str # change the name of run_str or it is impossible to subclass with a function cls.run_str = None = f # process variables cls.vars = list(set(cls.vars + dvars)) cls.vars.sort() if cls.vars: fun = compile_sig_vars(cls.vars) if fun: cls.sig_vars = fun elif getattr(cls, 'run', None) and not 'hcode' in cls.__dict__: # getattr(cls, 'hcode') would look in the upper classes cls.hcode = Utils.h_cmd( # be creative getattr(cls, 'register', classes)[name] = cls
evil = store_task_type('evil', (object,), {}) "Base class provided to avoid writing a metaclass, so the code can run in python 2.6 and 3.x unmodified"
[docs]class Task(evil): """ Task objects represents actions to perform such as commands to execute by calling the `run` method. Detecting when to execute a task occurs in the method :py:meth:`waflib.Task.Task.runnable_status`. Detecting which tasks to execute is performed through a hash value returned by :py:meth:`waflib.Task.Task.signature`. The task signature is persistent from build to build. """ vars = [] """ConfigSet variables that should trigger a rebuild (class attribute used for :py:meth:`waflib.Task.Task.sig_vars`)""" always_run = False """Specify whether task instances must always be executed or not (class attribute)""" shell = False """Execute the command with the shell (class attribute)""" color = 'GREEN' """Color for the console display, see :py:const:`waflib.Logs.colors_lst`""" ext_in = [] """File extensions that objects of this task class may use""" ext_out = [] """File extensions that objects of this task class may create""" before = [] """The instances of this class are executed before the instances of classes whose names are in this list""" after = [] """The instances of this class are executed after the instances of classes whose names are in this list""" hcode = Utils.SIG_NIL """String representing an additional hash for the class representation""" keep_last_cmd = False """Whether to keep the last command executed on the instance after execution. This may be useful for certain extensions but it can a lot of memory. """ weight = 0 """Optional weight to tune the priority for task instances. The higher, the earlier. The weight only applies to single task objects.""" tree_weight = 0 """Optional weight to tune the priority of task instances and whole subtrees. The higher, the earlier.""" prio_order = 0 """Priority order set by the scheduler on instances during the build phase. You most likely do not need to set it. """ __slots__ = ('hasrun', 'generator', 'env', 'inputs', 'outputs', 'dep_nodes', 'run_after') def __init__(self, *k, **kw): self.hasrun = NOT_RUN try: self.generator = kw['generator'] except KeyError: self.generator = self self.env = kw['env'] """:py:class:`waflib.ConfigSet.ConfigSet` object (make sure to provide one)""" self.inputs = [] """List of input nodes, which represent the files used by the task instance""" self.outputs = [] """List of output nodes, which represent the files created by the task instance""" self.dep_nodes = [] """List of additional nodes to depend on""" self.run_after = set() """Set of tasks that must be executed before this one""" def __lt__(self, other): return self.priority() > other.priority() def __le__(self, other): return self.priority() >= other.priority() def __gt__(self, other): return self.priority() < other.priority() def __ge__(self, other): return self.priority() <= other.priority()
[docs] def get_cwd(self): """ :return: current working directory :rtype: :py:class:`waflib.Node.Node` """ bld = self.generator.bld ret = getattr(self, 'cwd', None) or getattr(bld, 'cwd', bld.bldnode) if isinstance(ret, str): if os.path.isabs(ret): ret = bld.root.make_node(ret) else: ret = self.generator.path.make_node(ret) return ret
[docs] def quote_flag(self, x): """ Surround a process argument by quotes so that a list of arguments can be written to a file :param x: flag :type x: string :return: quoted flag :rtype: string """ old = x if '\\' in x: x = x.replace('\\', '\\\\') if '"' in x: x = x.replace('"', '\\"') if old != x or ' ' in x or '\t' in x or "'" in x: x = '"%s"' % x return x
[docs] def priority(self): """ Priority of execution; the higher, the earlier :return: the priority value :rtype: a tuple of numeric values """ return (self.weight + self.prio_order, - getattr(self.generator, 'tg_idx_count', 0))
[docs] def split_argfile(self, cmd): """ Splits a list of process commands into the executable part and its list of arguments :return: a tuple containing the executable first and then the rest of arguments :rtype: tuple """ return ([cmd[0]], [self.quote_flag(x) for x in cmd[1:]])
[docs] def exec_command(self, cmd, **kw): """ Wrapper for :py:meth:`waflib.Context.Context.exec_command`. This version set the current working directory (``build.variant_dir``), applies PATH settings (if self.env.PATH is provided), and can run long commands through a temporary ``@argfile``. :param cmd: process command to execute :type cmd: list of string (best) or string (process will use a shell) :return: the return code :rtype: int Optional parameters: #. cwd: current working directory (Node or string) #. stdout: set to None to prevent waf from capturing the process standard output #. stderr: set to None to prevent waf from capturing the process standard error #. timeout: timeout value (Python 3) """ if not 'cwd' in kw: kw['cwd'] = self.get_cwd() if hasattr(self, 'timeout'): kw['timeout'] = self.timeout if self.env.PATH: env = kw['env'] = dict(kw.get('env') or self.env.env or os.environ) env['PATH'] = self.env.PATH if isinstance(self.env.PATH, str) else os.pathsep.join(self.env.PATH) if hasattr(self, 'stdout'): kw['stdout'] = self.stdout if hasattr(self, 'stderr'): kw['stderr'] = self.stderr if not isinstance(cmd, str): if Utils.is_win32: # win32 compares the resulting length too_long = sum([len(arg) for arg in cmd]) + len(cmd) > 8192 else: # non-win32 counts the amount of arguments (200k) too_long = len(cmd) > 200000 if too_long and getattr(self, 'allow_argsfile', True): # Shunt arguments to a temporary file if the command is too long. cmd, args = self.split_argfile(cmd) try: (fd, tmp) = tempfile.mkstemp() os.write(fd, '\r\n'.join(args).encode()) os.close(fd) if Logs.verbose: Logs.debug('argfile: @%r -> %r', tmp, args) return self.generator.bld.exec_command(cmd + ['@' + tmp], **kw) finally: try: os.remove(tmp) except OSError: # anti-virus and indexers can keep files open -_- pass return self.generator.bld.exec_command(cmd, **kw)
def process(self): """ Runs the task and handles errors :return: 0 or None if everything is fine :rtype: integer """ # remove the task signature immediately before it is executed # so that the task will be executed again in case of failure try: del self.generator.bld.task_sigs[self.uid()] except KeyError: pass try: ret = except Exception: self.err_msg = traceback.format_exc() self.hasrun = EXCEPTION else: if ret: self.err_code = ret self.hasrun = CRASHED else: try: self.post_run() except Errors.WafError: pass except Exception: self.err_msg = traceback.format_exc() self.hasrun = EXCEPTION else: self.hasrun = SUCCESS if self.hasrun != SUCCESS and self.scan: # rescan dependencies on next run try: del self.generator.bld.imp_sigs[self.uid()] except KeyError: pass
[docs] def log_display(self, bld): "Writes the execution status on the context logger" if self.generator.bld.progress_bar == 3: return s = self.display() if s: if bld.logger: logger = bld.logger else: logger = Logs if self.generator.bld.progress_bar == 1: c1 = Logs.colors.cursor_off c2 = Logs.colors.cursor_on, extra={'stream': sys.stderr, 'terminator':'', 'c1': c1, 'c2' : c2}) else:, extra={'terminator':'', 'c1': '', 'c2' : ''})
[docs] def display(self): """ Returns an execution status for the console, the progress bar, or the IDE output. :rtype: string """ col1 = Logs.colors(self.color) col2 = Logs.colors.NORMAL master = self.generator.bld.producer def cur(): # the current task position, computed as late as possible return master.processed - master.ready.qsize() if self.generator.bld.progress_bar == 1: return self.generator.bld.progress_line(cur(),, col1, col2) if self.generator.bld.progress_bar == 2: ela = str(self.generator.bld.timer) try: ins = ','.join([ for n in self.inputs]) except AttributeError: ins = '' try: outs = ','.join([ for n in self.outputs]) except AttributeError: outs = '' return '|Total %s|Current %s|Inputs %s|Outputs %s|Time %s|\n' % (, cur(), ins, outs, ela) s = str(self) if not s: return None total = n = len(str(total)) fs = '[%%%dd/%%%dd] %%s%%s%%s%%s\n' % (n, n) kw = self.keyword() if kw: kw += ' ' return fs % (cur(), total, kw, col1, s, col2)
[docs] def hash_constraints(self): """ Identifies a task type for all the constraints relevant for the scheduler: precedence, file production :return: a hash value :rtype: string """ return (tuple(self.before), tuple(self.after), tuple(self.ext_in), tuple(self.ext_out), self.__class__.__name__, self.hcode)
[docs] def format_error(self): """ Returns an error message to display the build failure reasons :rtype: string """ if Logs.verbose: msg = ': %r\n%r' % (self, getattr(self, 'last_cmd', '')) else: msg = ' (run with -v to display more information)' name = getattr(self.generator, 'name', '') if getattr(self, "err_msg", None): return self.err_msg elif not self.hasrun: return 'task in %r was not executed for some reason: %r' % (name, self) elif self.hasrun == CRASHED: try: return ' -> task in %r failed with exit status %r%s' % (name, self.err_code, msg) except AttributeError: return ' -> task in %r failed%s' % (name, msg) elif self.hasrun == MISSING: return ' -> missing files in %r%s' % (name, msg) elif self.hasrun == CANCELED: return ' -> %r canceled because of missing dependencies' % name else: return 'invalid status for task in %r: %r' % (name, self.hasrun)
[docs] def colon(self, var1, var2): """ Enable scriptlet expressions of the form ${FOO_ST:FOO} If the first variable (FOO_ST) is empty, then an empty list is returned The results will be slightly different if FOO_ST is a list, for example:: env.FOO = ['p1', 'p2'] env.FOO_ST = '-I%s' # ${FOO_ST:FOO} returns ['-Ip1', '-Ip2'] env.FOO_ST = ['-a', '-b'] # ${FOO_ST:FOO} returns ['-a', '-b', 'p1', '-a', '-b', 'p2'] """ tmp = self.env[var1] if not tmp: return [] if isinstance(var2, str): it = self.env[var2] else: it = var2 if isinstance(tmp, str): return [tmp % x for x in it] else: lst = [] for y in it: lst.extend(tmp) lst.append(y) return lst
[docs] def __str__(self): "string to display to the user" name = self.__class__.__name__ if self.outputs: if name.endswith(('lib', 'program')) or not self.inputs: node = self.outputs[0] return node.path_from(node.ctx.launch_node()) if not (self.inputs or self.outputs): return self.__class__.__name__ if len(self.inputs) == 1: node = self.inputs[0] return node.path_from(node.ctx.launch_node()) src_str = ' '.join([a.path_from(a.ctx.launch_node()) for a in self.inputs]) tgt_str = ' '.join([a.path_from(a.ctx.launch_node()) for a in self.outputs]) if self.outputs: sep = ' -> ' else: sep = '' return '%s: %s%s%s' % (self.__class__.__name__, src_str, sep, tgt_str)
[docs] def keyword(self): "Display keyword used to prettify the console outputs" name = self.__class__.__name__ if name.endswith(('lib', 'program')): return 'Linking' if len(self.inputs) == 1 and len(self.outputs) == 1: return 'Compiling' if not self.inputs: if self.outputs: return 'Creating' else: return 'Running' return 'Processing'
[docs] def __repr__(self): "for debugging purposes" try: ins = ",".join([ for x in self.inputs]) outs = ",".join([ for x in self.outputs]) except AttributeError: ins = ",".join([str(x) for x in self.inputs]) outs = ",".join([str(x) for x in self.outputs]) return "".join(['\n\t{task %r: ' % id(self), self.__class__.__name__, " ", ins, " -> ", outs, '}'])
[docs] def uid(self): """ Returns an identifier used to determine if tasks are up-to-date. Since the identifier will be stored between executions, it must be: - unique for a task: no two tasks return the same value (for a given build context) - the same for a given task instance By default, the node paths, the class name, and the function are used as inputs to compute a hash. The pointer to the object (python built-in 'id') will change between build executions, and must be avoided in such hashes. :return: hash value :rtype: string """ try: return self.uid_ except AttributeError: m = Utils.md5(self.__class__.__name__) up = m.update for x in self.inputs + self.outputs: up(x.abspath()) self.uid_ = m.digest() return self.uid_
[docs] def set_inputs(self, inp): """ Appends the nodes to the *inputs* list :param inp: input nodes :type inp: node or list of nodes """ if isinstance(inp, list): self.inputs += inp else: self.inputs.append(inp)
[docs] def set_outputs(self, out): """ Appends the nodes to the *outputs* list :param out: output nodes :type out: node or list of nodes """ if isinstance(out, list): self.outputs += out else: self.outputs.append(out)
[docs] def set_run_after(self, task): """ Run this task only after the given *task*. Calling this method from :py:meth:`waflib.Task.Task.runnable_status` may cause build deadlocks; see :py:meth:`waflib.Tools.fc.fc.runnable_status` for details. :param task: task :type task: :py:class:`waflib.Task.Task` """ assert isinstance(task, Task) self.run_after.add(task)
[docs] def signature(self): """ Task signatures are stored between build executions, they are use to track the changes made to the input nodes (not to the outputs!). The signature hashes data from various sources: * explicit dependencies: files listed in the inputs (list of node objects) :py:meth:`waflib.Task.Task.sig_explicit_deps` * implicit dependencies: list of nodes returned by scanner methods (when present) :py:meth:`waflib.Task.Task.sig_implicit_deps` * hashed data: variables/values read from task.vars/task.env :py:meth:`waflib.Task.Task.sig_vars` If the signature is expected to give a different result, clear the cache kept in ``self.cache_sig``:: from waflib import Task class cls(Task.Task): def signature(self): sig = super(Task.Task, self).signature() delattr(self, 'cache_sig') return super(Task.Task, self).signature() :return: the signature value :rtype: string or bytes """ try: return self.cache_sig except AttributeError: pass self.m = Utils.md5(self.hcode) # explicit deps self.sig_explicit_deps() # env vars self.sig_vars() # implicit deps / scanner results if self.scan: try: self.sig_implicit_deps() except Errors.TaskRescan: return self.signature() ret = self.cache_sig = self.m.digest() return ret
[docs] def runnable_status(self): """ Returns the Task status :return: a task state in :py:const:`waflib.Task.RUN_ME`, :py:const:`waflib.Task.SKIP_ME`, :py:const:`waflib.Task.CANCEL_ME` or :py:const:`waflib.Task.ASK_LATER`. :rtype: int """ bld = self.generator.bld if bld.is_install < 0: return SKIP_ME for t in self.run_after: if not t.hasrun: return ASK_LATER elif t.hasrun < SKIPPED: # a dependency has an error return CANCEL_ME # first compute the signature try: new_sig = self.signature() except Errors.TaskNotReady: return ASK_LATER # compare the signature to a signature computed previously key = self.uid() try: prev_sig = bld.task_sigs[key] except KeyError: Logs.debug('task: task %r must run: it was never run before or the task code changed', self) return RUN_ME if new_sig != prev_sig: Logs.debug('task: task %r must run: the task signature changed', self) return RUN_ME # compare the signatures of the outputs for node in self.outputs: sig = bld.node_sigs.get(node) if not sig: Logs.debug('task: task %r must run: an output node has no signature', self) return RUN_ME if sig != key: Logs.debug('task: task %r must run: an output node was produced by another task', self) return RUN_ME if not node.exists(): Logs.debug('task: task %r must run: an output node does not exist', self) return RUN_ME return (self.always_run and RUN_ME) or SKIP_ME
[docs] def post_run(self): """ Called after successful execution to record that the task has run by updating the entry in :py:attr:`waflib.Build.BuildContext.task_sigs`. """ bld = self.generator.bld for node in self.outputs: if not node.exists(): self.hasrun = MISSING self.err_msg = '-> missing file: %r' % node.abspath() raise Errors.WafError(self.err_msg) bld.node_sigs[node] = self.uid() # make sure this task produced the files in question bld.task_sigs[self.uid()] = self.signature() if not self.keep_last_cmd: try: del self.last_cmd except AttributeError: pass
[docs] def sig_explicit_deps(self): """ Used by :py:meth:`waflib.Task.Task.signature`; it hashes :py:attr:`waflib.Task.Task.inputs` and :py:attr:`waflib.Task.Task.dep_nodes` signatures. """ bld = self.generator.bld upd = self.m.update # the inputs for x in self.inputs + self.dep_nodes: upd(x.get_bld_sig()) # manual dependencies, they can slow down the builds if bld.deps_man: additional_deps = bld.deps_man for x in self.inputs + self.outputs: try: d = additional_deps[x] except KeyError: continue for v in d: try: v = v.get_bld_sig() except AttributeError: if hasattr(v, '__call__'): v = v() # dependency is a function, call it upd(v)
[docs] def sig_deep_inputs(self): """ Enable rebuilds on input files task signatures. Not used by default. Example: hashes of output programs can be unchanged after being re-linked, despite the libraries being different. This method can thus prevent stale unit test results ( Hashing input file timestamps is another possibility for the implementation. This may cause unnecessary rebuilds when input tasks are frequently executed. Here is an implementation example:: lst = [] for node in self.inputs + self.dep_nodes: st = os.stat(node.abspath()) lst.append(st.st_mtime) lst.append(st.st_size) self.m.update(Utils.h_list(lst)) The downside of the implementation is that it absolutely requires all build directory files to be declared within the current build. """ bld = self.generator.bld lst = [bld.task_sigs[bld.node_sigs[node]] for node in (self.inputs + self.dep_nodes) if node.is_bld()] self.m.update(Utils.h_list(lst))
[docs] def sig_vars(self): """ Used by :py:meth:`waflib.Task.Task.signature`; it hashes :py:attr:`waflib.Task.Task.env` variables/values When overriding this method, and if scriptlet expressions are used, make sure to follow the code in :py:meth:`waflib.Task.Task.compile_sig_vars` to enable dependencies on scriptlet results. This method may be replaced on subclasses by the metaclass to force dependencies on scriptlet code. """ sig = self.generator.bld.hash_env_vars(self.env, self.vars) self.m.update(sig)
scan = None """ This method, when provided, returns a tuple containing: * a list of nodes corresponding to real files * a list of names for files not found in path_lst For example:: from waflib.Task import Task class mytask(Task): def scan(self, node): return ([], []) The first and second lists in the tuple are stored in :py:attr:`waflib.Build.BuildContext.node_deps` and :py:attr:`waflib.Build.BuildContext.raw_deps` respectively. """
[docs] def sig_implicit_deps(self): """ Used by :py:meth:`waflib.Task.Task.signature`; it hashes node signatures obtained by scanning for dependencies (:py:meth:`waflib.Task.Task.scan`). The exception :py:class:`waflib.Errors.TaskRescan` is thrown when a file has changed. In this case, the method :py:meth:`waflib.Task.Task.signature` is called once again, and return here to call :py:meth:`waflib.Task.Task.scan` and searching for dependencies. """ bld = self.generator.bld # get the task signatures from previous runs key = self.uid() prev = bld.imp_sigs.get(key, []) # for issue #379 if prev: try: if prev == self.compute_sig_implicit_deps(): return prev except Errors.TaskNotReady: raise except EnvironmentError: # when a file was renamed, remove the stale nodes (headers in folders without source files) # this will break the order calculation for headers created during the build in the source directory (should be uncommon) # the behaviour will differ when top != out for x in bld.node_deps.get(self.uid(), []): if not x.is_bld() and not x.exists(): try: del x.parent.children[] except KeyError: pass del bld.imp_sigs[key] raise Errors.TaskRescan('rescan') # no previous run or the signature of the dependencies has changed, rescan the dependencies (bld.node_deps[key], bld.raw_deps[key]) = self.scan() if Logs.verbose: Logs.debug('deps: scanner for %s: %r; unresolved: %r', self, bld.node_deps[key], bld.raw_deps[key]) # recompute the signature and return it try: bld.imp_sigs[key] = self.compute_sig_implicit_deps() except EnvironmentError: for k in bld.node_deps.get(self.uid(), []): if not k.exists(): Logs.warn('Dependency %r for %r is missing: check the task declaration and the build order!', k, self) raise
[docs] def compute_sig_implicit_deps(self): """ Used by :py:meth:`waflib.Task.Task.sig_implicit_deps` for computing the actual hash of the :py:class:`waflib.Node.Node` returned by the scanner. :return: a hash value for the implicit dependencies :rtype: string or bytes """ upd = self.m.update self.are_implicit_nodes_ready() # scanner returns a node that does not have a signature # just *ignore* the error and let them figure out from the compiler output # waf -k behaviour for k in self.generator.bld.node_deps.get(self.uid(), []): upd(k.get_bld_sig()) return self.m.digest()
[docs] def are_implicit_nodes_ready(self): """ For each node returned by the scanner, see if there is a task that creates it, and infer the build order This has a low performance impact on null builds (1.86s->1.66s) thanks to caching (28s->1.86s) """ bld = self.generator.bld try: cache = bld.dct_implicit_nodes except AttributeError: bld.dct_implicit_nodes = cache = {} # one cache per build group try: dct = cache[bld.current_group] except KeyError: dct = cache[bld.current_group] = {} for tsk in bld.cur_tasks: for x in tsk.outputs: dct[x] = tsk modified = False for x in bld.node_deps.get(self.uid(), []): if x in dct: self.run_after.add(dct[x]) modified = True if modified: for tsk in self.run_after: if not tsk.hasrun: #print "task is not ready..." raise Errors.TaskNotReady('not ready')
if sys.hexversion > 0x3000000:
[docs] def uid(self): try: return self.uid_ except AttributeError: m = Utils.md5(self.__class__.__name__.encode('latin-1', 'xmlcharrefreplace')) up = m.update for x in self.inputs + self.outputs: up(x.abspath().encode('latin-1', 'xmlcharrefreplace')) self.uid_ = m.digest() return self.uid_
uid.__doc__ = Task.uid.__doc__ Task.uid = uid
[docs]def is_before(t1, t2): """ Returns a non-zero value if task t1 is to be executed before task t2:: t1.ext_out = '.h' t2.ext_in = '.h' t2.after = ['t1'] t1.before = ['t2'] waflib.Task.is_before(t1, t2) # True :param t1: Task object :type t1: :py:class:`waflib.Task.Task` :param t2: Task object :type t2: :py:class:`waflib.Task.Task` """ to_list = Utils.to_list for k in to_list(t2.ext_in): if k in to_list(t1.ext_out): return 1 if t1.__class__.__name__ in to_list(t2.after): return 1 if t2.__class__.__name__ in to_list(t1.before): return 1 return 0
[docs]def set_file_constraints(tasks): """ Updates the ``run_after`` attribute of all tasks based on the task inputs and outputs :param tasks: tasks :type tasks: list of :py:class:`waflib.Task.Task` """ ins = Utils.defaultdict(set) outs = Utils.defaultdict(set) for x in tasks: for a in x.inputs: ins[a].add(x) for a in x.dep_nodes: ins[a].add(x) for a in x.outputs: outs[a].add(x) links = set(ins.keys()).intersection(outs.keys()) for k in links: for a in ins[k]: a.run_after.update(outs[k])
[docs]class TaskGroup(object): """ Wrap nxm task order constraints into a single object to prevent the creation of large list/set objects This is an optimization """ def __init__(self, prev, next): self.prev = prev = next self.done = False def get_hasrun(self): for k in self.prev: if not k.hasrun: return NOT_RUN return SUCCESS hasrun = property(get_hasrun, None)
[docs]def set_precedence_constraints(tasks): """ Updates the ``run_after`` attribute of all tasks based on the after/before/ext_out/ext_in attributes :param tasks: tasks :type tasks: list of :py:class:`waflib.Task.Task` """ cstr_groups = Utils.defaultdict(list) for x in tasks: h = x.hash_constraints() cstr_groups[h].append(x) keys = list(cstr_groups.keys()) maxi = len(keys) # this list should be short for i in range(maxi): t1 = cstr_groups[keys[i]][0] for j in range(i + 1, maxi): t2 = cstr_groups[keys[j]][0] # add the constraints based on the comparisons if is_before(t1, t2): a = i b = j elif is_before(t2, t1): a = j b = i else: continue a = cstr_groups[keys[a]] b = cstr_groups[keys[b]] if len(a) < 2 or len(b) < 2: for x in b: x.run_after.update(a) else: group = TaskGroup(set(a), set(b)) for x in b: x.run_after.add(group)
[docs]def funex(c): """ Compiles a scriptlet expression into a Python function :param c: function to compile :type c: string :return: the function 'f' declared in the input string :rtype: function """ dc = {} exec(c, dc) return dc['f']
re_cond = re.compile(r'(?P<var>\w+)|(?P<or>\|)|(?P<and>&)') re_novar = re.compile(r'^(SRC|TGT)\W+.*?$') reg_act = re.compile(r'(?P<backslash>\\)|(?P<dollar>\$\$)|(?P<subst>\$\{(?P<var>\w+)(?P<code>.*?)\})', re.M)
[docs]def compile_fun_shell(line): """ Creates a compiled function to execute a process through a sub-shell """ extr = [] def repl(match): g = if g('dollar'): return "$" elif g('backslash'): return '\\\\' elif g('subst'): extr.append((g('var'), g('code'))) return "%s" return None line = reg_act.sub(repl, line) or line dvars = [] def add_dvar(x): if x not in dvars: dvars.append(x) def replc(m): # performs substitutions and populates dvars if'and'): return ' and ' elif'or'): return ' or ' else: x ='var') add_dvar(x) return 'env[%r]' % x parm = [] app = parm.append for (var, meth) in extr: if var == 'SRC': if meth: app('tsk.inputs%s' % meth) else: app('" ".join([a.path_from(cwdx) for a in tsk.inputs])') elif var == 'TGT': if meth: app('tsk.outputs%s' % meth) else: app('" ".join([a.path_from(cwdx) for a in tsk.outputs])') elif meth: if meth.startswith(':'): add_dvar(var) m = meth[1:] if m == 'SRC': m = '[a.path_from(cwdx) for a in tsk.inputs]' elif m == 'TGT': m = '[a.path_from(cwdx) for a in tsk.outputs]' elif re_novar.match(m): m = '[tsk.inputs%s]' % m[3:] elif re_novar.match(m): m = '[tsk.outputs%s]' % m[3:] else: add_dvar(m) if m[:3] not in ('tsk', 'gen', 'bld'): m = '%r' % m app('" ".join(tsk.colon(%r, %s))' % (var, m)) elif meth.startswith('?'): # In A?B|C output env.A if one of env.B or env.C is non-empty expr = re_cond.sub(replc, meth[1:]) app('p(%r) if (%s) else ""' % (var, expr)) else: call = '%s%s' % (var, meth) add_dvar(call) app(call) else: add_dvar(var) app("p('%s')" % var) if parm: parm = "%% (%s) " % (',\n\t\t'.join(parm)) else: parm = '' c = COMPILE_TEMPLATE_SHELL % (line, parm) Logs.debug('action: %s', c.strip().splitlines()) return (funex(c), dvars)
reg_act_noshell = re.compile(r"(?P<space>\s+)|(?P<subst>\$\{(?P<var>\w+)(?P<code>.*?)\})|(?P<text>([^$ \t\n\r\f\v]|\$\$)+)", re.M)
[docs]def compile_fun_noshell(line): """ Creates a compiled function to execute a process without a sub-shell """ buf = [] dvars = [] merge = False app = buf.append def add_dvar(x): if x not in dvars: dvars.append(x) def replc(m): # performs substitutions and populates dvars if'and'): return ' and ' elif'or'): return ' or ' else: x ='var') add_dvar(x) return 'env[%r]' % x for m in reg_act_noshell.finditer(line): if'space'): merge = False continue elif'text'): app('[%r]' %'text').replace('$$', '$')) elif'subst'): var ='var') code ='code') if var == 'SRC': if code: app('[tsk.inputs%s]' % code) else: app('[a.path_from(cwdx) for a in tsk.inputs]') elif var == 'TGT': if code: app('[tsk.outputs%s]' % code) else: app('[a.path_from(cwdx) for a in tsk.outputs]') elif code: if code.startswith(':'): # a composed variable ${FOO:OUT} add_dvar(var) m = code[1:] if m == 'SRC': m = '[a.path_from(cwdx) for a in tsk.inputs]' elif m == 'TGT': m = '[a.path_from(cwdx) for a in tsk.outputs]' elif re_novar.match(m): m = '[tsk.inputs%s]' % m[3:] elif re_novar.match(m): m = '[tsk.outputs%s]' % m[3:] else: add_dvar(m) if m[:3] not in ('tsk', 'gen', 'bld'): m = '%r' % m app('tsk.colon(%r, %s)' % (var, m)) elif code.startswith('?'): # In A?B|C output env.A if one of env.B or env.C is non-empty expr = re_cond.sub(replc, code[1:]) app('to_list(env[%r] if (%s) else [])' % (var, expr)) else: # plain code such as ${tsk.inputs[0].abspath()} call = '%s%s' % (var, code) add_dvar(call) app('to_list(%s)' % call) else: # a plain variable such as # a plain variable like ${AR} app('to_list(env[%r])' % var) add_dvar(var) if merge: tmp = 'merge(%s, %s)' % (buf[-2], buf[-1]) del buf[-1] buf[-1] = tmp merge = True # next turn buf = ['lst.extend(%s)' % x for x in buf] fun = COMPILE_TEMPLATE_NOSHELL % "\n\t".join(buf) Logs.debug('action: %s', fun.strip().splitlines()) return (funex(fun), dvars)
[docs]def compile_fun(line, shell=False): """ Parses a string expression such as '${CC} ${SRC} -o ${TGT}' and returns a pair containing: * The function created (compiled) for use as :py:meth:`` * The list of variables that must cause rebuilds when *env* data is modified for example:: from waflib.Task import compile_fun compile_fun('cxx', '${CXX} -o ${TGT[0]} ${SRC} -I ${SRC[0].parent.bldpath()}') def build(bld): bld(source='wscript', rule='echo "foo\\${SRC[0].name}\\bar"') The env variables (CXX, ..) on the task must not hold dicts so as to preserve a consistent order. The reserved keywords ``TGT`` and ``SRC`` represent the task input and output nodes """ if isinstance(line, str): if line.find('<') > 0 or line.find('>') > 0 or line.find('&&') > 0: shell = True else: dvars_lst = [] funs_lst = [] for x in line: if isinstance(x, str): fun, dvars = compile_fun(x, shell) dvars_lst += dvars funs_lst.append(fun) else: # assume a function to let through funs_lst.append(x) def composed_fun(task): for x in funs_lst: ret = x(task) if ret: return ret return None return composed_fun, dvars_lst if shell: return compile_fun_shell(line) else: return compile_fun_noshell(line)
[docs]def compile_sig_vars(vars): """ This method produces a sig_vars method suitable for subclasses that provide scriptlet code in their run_str code. If no such method can be created, this method returns None. The purpose of the sig_vars method returned is to ensures that rebuilds occur whenever the contents of the expression changes. This is the case B below:: import time # case A: regular variables tg = bld(rule='echo ${FOO}') tg.env.FOO = '%s' % time.time() # case B bld(rule='echo ${}', foo='%s' % time.time()) :param vars: env variables such as CXXFLAGS or :type vars: list of string :return: A sig_vars method relevant for dependencies if adequate, else None :rtype: A function, or None in most cases """ buf = [] for x in sorted(vars): if x[:3] in ('tsk', 'gen', 'bld'): buf.append('buf.append(%s)' % x) if buf: return funex(COMPILE_TEMPLATE_SIG_VARS % '\n\t'.join(buf)) return None
[docs]def task_factory(name, func=None, vars=None, color='GREEN', ext_in=[], ext_out=[], before=[], after=[], shell=False, scan=None): """ Returns a new task subclass with the function ``run`` compiled from the line given. :param func: method run :type func: string or function :param vars: list of variables to hash :type vars: list of string :param color: color to use :type color: string :param shell: when *func* is a string, enable/disable the use of the shell :type shell: bool :param scan: method scan :type scan: function :rtype: :py:class:`waflib.Task.Task` """ params = { 'vars': vars or [], # function arguments are static, and this one may be modified by the class 'color': color, 'name': name, 'shell': shell, 'scan': scan, } if isinstance(func, str) or isinstance(func, tuple): params['run_str'] = func else: params['run'] = func cls = type(Task)(name, (Task,), params) classes[name] = cls if ext_in: cls.ext_in = Utils.to_list(ext_in) if ext_out: cls.ext_out = Utils.to_list(ext_out) if before: cls.before = Utils.to_list(before) if after: cls.after = Utils.to_list(after) return cls
[docs]def deep_inputs(cls): """ Task class decorator to enable rebuilds on input files task signatures """ def sig_explicit_deps(self): Task.sig_explicit_deps(self) Task.sig_deep_inputs(self) cls.sig_explicit_deps = sig_explicit_deps return cls
TaskBase = Task "Provided for compatibility reasons, TaskBase should not be used"
[docs]class TaskSemaphore(object): """ Task semaphores provide a simple and efficient way of throttling the amount of a particular task to run concurrently. The throttling value is capped by the amount of maximum jobs, so for example, a `TaskSemaphore(10)` has no effect in a `-j2` build. Task semaphores are typically specified on the task class level:: class compile(waflib.Task.Task): semaphore = waflib.Task.TaskSemaphore(2) run_str = 'touch ${TGT}' Task semaphores are meant to be used by the build scheduler in the main thread, so there are no guarantees of thread safety. """
[docs] def __init__(self, num): """ :param num: maximum value of concurrent tasks :type num: int """ self.num = num self.locking = set() self.waiting = set()
[docs] def is_locked(self): """Returns True if this semaphore cannot be acquired by more tasks""" return len(self.locking) >= self.num
[docs] def acquire(self, tsk): """ Mark the semaphore as used by the given task (not re-entrant). :param tsk: task object :type tsk: :py:class:`waflib.Task.Task` :raises: :py:class:`IndexError` in case the resource is already acquired """ if self.is_locked(): raise IndexError('Cannot lock more %r' % self.locking) self.locking.add(tsk)
[docs] def release(self, tsk): """ Mark the semaphore as unused by the given task. :param tsk: task object :type tsk: :py:class:`waflib.Task.Task` :raises: :py:class:`KeyError` in case the resource is not acquired by the task """ self.locking.remove(tsk)