#!/usr/bin/env python
# encoding: utf-8
# Thomas Nagy, 2005-2010 (ita)
"""
Tasks represent atomic operations such as processes.
"""
import os, shutil, re, tempfile
from waflib import Utils, Logs, Errors
# task states
NOT_RUN = 0
"""The task was not executed yet"""
MISSING = 1
"""The task has been executed but the files have not been created"""
CRASHED = 2
"""The task execution returned a non-zero exit status"""
EXCEPTION = 3
"""An exception occured in the task execution"""
SKIPPED = 8
"""The task did not have to be executed"""
SUCCESS = 9
"""The task was successfully executed"""
ASK_LATER = -1
"""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"""
COMPILE_TEMPLATE_SHELL = '''
def f(tsk):
env = tsk.env
gen = tsk.generator
bld = gen.bld
wd = getattr(tsk, 'cwd', None)
p = env.get_flat
tsk.last_cmd = cmd = \'\'\' %s \'\'\' % s
return tsk.exec_command(cmd, cwd=wd, env=env.env or None)
'''
COMPILE_TEMPLATE_NOSHELL = '''
def f(tsk):
env = tsk.env
gen = tsk.generator
bld = gen.bld
wd = getattr(tsk, 'cwd', None)
def to_list(xx):
if isinstance(xx, str): return [xx]
return xx
tsk.last_cmd = lst = []
%s
lst = [x for x in lst if x]
return tsk.exec_command(lst, cwd=wd, env=env.env or None)
'''
def cache_outputs(cls):
"""
Task class decorator applied to all task classes by default unless they define the attribute 'nocache'::
from waflib import Task
class foo(Task.Task):
nocache = True
If bld.cache_global is defined and if the task instances produces output nodes,
the files will be copied into a folder in the cache directory
The files may also be retrieved from that folder, if it exists
"""
m1 = cls.run
def run(self):
bld = self.generator.bld
if bld.cache_global and not bld.nocache:
if self.can_retrieve_cache():
return 0
return m1(self)
cls.run = run
m2 = cls.post_run
def post_run(self):
bld = self.generator.bld
ret = m2(self)
if bld.cache_global and not bld.nocache:
self.put_files_cache()
return ret
cls.post_run = post_run
return cls
classes = {}
"class tasks created by user scripts or Waf tools are kept in this dict name -> class object"
class store_task_type(type):
"""
Metaclass: store the task classes into :py:const:`waflib.Task.classes`, or to the dict pointed
by the class attribute 'register'.
The attribute 'run_str' will be processed to compute a method 'run' on the task class
The decorator :py:func:`waflib.Task.cache_outputs` is also applied to the class
"""
def __init__(cls, name, bases, dict):
super(store_task_type, cls).__init__(name, bases, dict)
name = cls.__name__
if name.endswith('_task'):
name = name.replace('_task', '')
if name != 'evil' and name != 'TaskBase':
global classes
if getattr(cls, 'run_str', None):
# if a string is provided, convert it to a method
(f, dvars) = compile_fun(cls.run_str, cls.shell)
cls.hcode = cls.run_str
cls.run_str = None
cls.run = f
cls.vars = list(set(cls.vars + dvars))
cls.vars.sort()
elif getattr(cls, 'run', None) and not 'hcode' in cls.__dict__:
# getattr(cls, 'hcode') would look in the upper classes
cls.hcode = Utils.h_fun(cls.run)
if not getattr(cls, 'nocache', None):
cls = cache_outputs(cls)
# 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"
class TaskBase(evil):
"""
Base class for all Waf tasks, which should be seen as an interface.
For illustration purposes, instances of this class will execute the attribute
'fun' in :py:meth:`waflib.Task.TaskBase.run`. When in doubt, create
subclasses of :py:class:`waflib.Task.Task` instead.
Subclasses should override these methods:
#. __str__: string to display to the user
#. runnable_status: ask the task if it should be run, skipped, or if we have to ask later
#. run: let threads execute the task
#. post_run: let threads update the data regarding the task (cache)
"""
color = 'GREEN'
"""Color for the console display, see :py:const:`waflib.Logs.colors_lst`"""
ext_in = []
"""File extensions that objects of this task class might use"""
ext_out = []
"""File extensions that objects of this task class might create"""
before = []
"""List of task class names to execute before instances of this class"""
after = []
"""List of task class names to execute after instances of this class"""
hcode = ''
"""String representing an additional hash for the class representation"""
def __init__(self, *k, **kw):
"""
The base task class requires a task generator, which will be itself if missing
"""
self.hasrun = NOT_RUN
try:
self.generator = kw['generator']
except KeyError:
self.generator = self
def __repr__(self):
"for debugging purposes"
return '\n\t{task %r: %s %s}' % (self.__class__.__name__, id(self), str(getattr(self, 'fun', '')))
def __str__(self):
"string to display to the user"
if hasattr(self, 'fun'):
return 'executing: %s\n' % self.fun.__name__
return self.__class__.__name__ + '\n'
def __hash__(self):
"Very fast hashing scheme but not persistent (replace/implement in subclasses and see :py:meth:`waflib.Task.Task.uid`)"
return id(self)
def exec_command(self, cmd, **kw):
"""
Wrapper for :py:meth:`waflib.Context.Context.exec_command` which sets a current working directory to ``build.variant_dir``
:return: the return code
:rtype: int
"""
bld = self.generator.bld
try:
if not kw.get('cwd', None):
kw['cwd'] = bld.cwd
except AttributeError:
bld.cwd = kw['cwd'] = bld.variant_dir
return bld.exec_command(cmd, **kw)
def runnable_status(self):
"""
State of the task
:return: a task state in :py:const:`waflib.Task.RUN_ME`, :py:const:`waflib.Task.SKIP_ME` or :py:const:`waflib.Task.ASK_LATER`.
:rtype: int
"""
return RUN_ME
def process(self):
"""
Assume that the task has had a new attribute ``master`` which is an instance of :py:class:`waflib.Runner.Parallel`.
Execute the task and then put it back in the queue :py:attr:`waflib.Runner.Parallel.out` (may be replaced by subclassing).
"""
m = self.master
if m.stop:
m.out.put(self)
return
# remove the task signature immediately before it is executed
# in case of failure the task will be executed again
try:
del self.generator.bld.task_sigs[self.uid()]
except KeyError:
pass
try:
self.generator.bld.returned_tasks.append(self)
self.log_display(self.generator.bld)
ret = self.run()
except Exception:
self.err_msg = Utils.ex_stack()
self.hasrun = EXCEPTION
# TODO cleanup
m.error_handler(self)
m.out.put(self)
return
if ret:
self.err_code = ret
self.hasrun = CRASHED
else:
try:
self.post_run()
except Errors.WafError:
pass
except Exception:
self.err_msg = Utils.ex_stack()
self.hasrun = EXCEPTION
else:
self.hasrun = SUCCESS
if self.hasrun != SUCCESS:
m.error_handler(self)
m.out.put(self)
def run(self):
"""
Called by threads to execute the tasks. The default is empty and meant to be overridden in subclasses.
It is a bad idea to create nodes in this method (so, no node.ant_glob)
:rtype: int
"""
if hasattr(self, 'fun'):
return self.fun(self)
return 0
def post_run(self):
"Update the cache files (executed by threads). Override in subclasses."
pass
def log_display(self, bld):
"Write the execution status on the context logger"
bld.to_log(self.display())
def display(self):
"""
Return 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.master
def cur():
# the current task position, computed as late as possible
tmp = -1
if hasattr(master, 'ready'):
tmp -= master.ready.qsize()
return master.processed + tmp
if self.generator.bld.progress_bar == 1:
return self.generator.bld.progress_line(cur(), master.total, col1, col2)
if self.generator.bld.progress_bar == 2:
ela = str(self.generator.bld.timer)
try:
ins = ','.join([n.name for n in self.inputs])
except AttributeError:
ins = ''
try:
outs = ','.join([n.name for n in self.outputs])
except AttributeError:
outs = ''
return '|Total %s|Current %s|Inputs %s|Outputs %s|Time %s|\n' % (master.total, cur(), ins, outs, ela)
s = str(self)
if not s:
return None
total = master.total
n = len(str(total))
fs = '[%%%dd/%%%dd] %%s%%s%%s' % (n, n)
return fs % (cur(), total, col1, s, col2)
def attr(self, att, default=None):
"""
Retrieve an attribute from the instance or from the class.
:param att: variable name
:type att: string
:param default: default value
"""
ret = getattr(self, att, self)
if ret is self: return getattr(self.__class__, att, default)
return ret
def hash_constraints(self):
"""
Identify a task type for all the constraints relevant for the scheduler: precedence, file production
:return: a hash value
:rtype: string
"""
cls = self.__class__
tup = (str(cls.before), str(cls.after), str(cls.ext_in), str(cls.ext_out), cls.__name__, cls.hcode)
h = hash(tup)
return h
def format_error(self):
"""
Error message to display to the user when a build fails
:rtype: string
"""
msg = getattr(self, 'last_cmd', '')
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 (exit status %r): %r\n%r' % (name, self.err_code, self, msg)
except AttributeError:
return ' -> task in %r failed: %r\n%r' % (name, self, msg)
elif self.hasrun == MISSING:
return ' -> missing files in %r: %r\n%r' % (name, self, msg)
else:
return 'invalid status for task in %r: %r' % (name, self.hasrun)
def colon(self, var1, var2):
"""
private function for the moment
used for scriptlet expressions such as ${FOO_ST:FOO}, for example, if
env.FOO_ST = ['-a', '-b']
env.FOO = ['1', '2']
then the result will be ['-a', '-b', '1', '-a', '-b', '2']
"""
tmp = self.env[var1]
if isinstance(var2, str):
it = self.env[var2]
else:
it = var2
if isinstance(tmp, str):
return [tmp % x for x in it]
else:
if Logs.verbose and not tmp and it:
Logs.warn('Missing env variable %r for task %r (generator %r)' % (var1, self, self.generator))
lst = []
for y in it:
lst.extend(tmp)
lst.append(y)
return lst
class Task(TaskBase):
"""
This class deals with the filesystem (:py:class:`waflib.Node.Node`). The method :py:class:`waflib.Task.Task.runnable_status`
uses a hash value (from :py:class:`waflib.Task.Task.signature`) which is persistent from build to build. When the value changes,
the task has to be executed. The method :py:class:`waflib.Task.Task.post_run` will assign the task signature to the output
nodes (if present).
"""
vars = []
"""Variables to depend on (class attribute used for :py:meth:`waflib.Task.Task.sig_vars`)"""
shell = False
"""Execute the command with the shell (class attribute)"""
def __init__(self, *k, **kw):
TaskBase.__init__(self, *k, **kw)
self.env = kw['env']
"""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"""
# Additionally, you may define the following
#self.dep_vars = 'PREFIX DATADIR'
def __str__(self):
"string to display to the user"
env = self.env
src_str = ' '.join([a.nice_path() for a in self.inputs])
tgt_str = ' '.join([a.nice_path() for a in self.outputs])
if self.outputs: sep = ' -> '
else: sep = ''
return '%s: %s%s%s\n' % (self.__class__.__name__.replace('_task', ''), src_str, sep, tgt_str)
def __repr__(self):
"for debugging purposes"
try:
ins = ",".join([x.name for x in self.inputs])
outs = ",".join([x.name 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, '}'])
def uid(self):
"""
Return an identifier used to determine if tasks are up-to-date. Since the
identifier will be stored between executions, it must be:
- unique: 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:
# this is not a real hot zone, but we want to avoid surprises here
m = Utils.md5()
up = m.update
up(self.__class__.__name__.encode())
for x in self.inputs + self.outputs:
up(x.abspath().encode())
self.uid_ = m.digest()
return self.uid_
def set_inputs(self, inp):
"""
Append the nodes to the *inputs*
:param inp: input nodes
:type inp: node or list of nodes
"""
if isinstance(inp, list): self.inputs += inp
else: self.inputs.append(inp)
def set_outputs(self, out):
"""
Append the nodes to the *outputs*
:param out: output nodes
:type out: node or list of nodes
"""
if isinstance(out, list): self.outputs += out
else: self.outputs.append(out)
def set_run_after(self, task):
"""
Run this task only after *task*. Affect :py:meth:`waflib.Task.runnable_status`
You probably want to use tsk.run_after.add(task) directly
:param task: task
:type task: :py:class:`waflib.Task.Task`
"""
assert isinstance(task, TaskBase)
self.run_after.add(task)
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.__class__.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()
"""
try: return self.cache_sig
except AttributeError: pass
self.m = Utils.md5()
self.m.update(self.hcode.encode())
# 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
def runnable_status(self):
"""
Override :py:meth:`waflib.Task.TaskBase.runnable_status` to determine if the task is ready
to be run (:py:attr:`waflib.Task.Task.run_after`)
"""
#return 0 # benchmarking
for t in self.run_after:
if not t.hasrun:
return ASK_LATER
bld = self.generator.bld
# 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 as it was never run before or the task code changed" % self)
return RUN_ME
# compare the signatures of the outputs
for node in self.outputs:
try:
if node.sig != new_sig:
return RUN_ME
except AttributeError:
Logs.debug("task: task %r must run as the output nodes do not exist" % self)
return RUN_ME
if new_sig != prev_sig:
return RUN_ME
return SKIP_ME
def post_run(self):
"""
Called after successful execution to update the cache data :py:class:`waflib.Node.Node` sigs
and :py:attr:`waflib.Build.BuildContext.task_sigs`.
The node signature is obtained from the task signature, but the output nodes may also get the signature
of their contents. See the class decorator :py:func:`waflib.Task.update_outputs` if you need this behaviour.
"""
bld = self.generator.bld
sig = self.signature()
for node in self.outputs:
# check if the node exists ..
try:
os.stat(node.abspath())
except OSError:
self.hasrun = MISSING
self.err_msg = '-> missing file: %r' % node.abspath()
raise Errors.WafError(self.err_msg)
# important, store the signature for the next run
node.sig = sig
bld.task_sigs[self.uid()] = self.cache_sig
def sig_explicit_deps(self):
"""
Used by :py:meth:`waflib.Task.Task.signature`, hash :py:attr:`waflib.Task.Task.inputs`
and :py:attr:`waflib.Task.Task.dep_nodes` signatures.
:rtype: hash value
"""
bld = self.generator.bld
upd = self.m.update
# the inputs
for x in self.inputs + self.dep_nodes:
try:
upd(x.get_bld_sig())
except (AttributeError, TypeError):
raise Errors.WafError('Missing node signature for %r (required by %r)' % (x, self))
# 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[id(x)]
except KeyError:
continue
for v in d:
if isinstance(v, bld.root.__class__):
try:
v = v.get_bld_sig()
except AttributeError:
raise Errors.WafError('Missing node signature for %r (required by %r)' % (v, self))
elif hasattr(v, '__call__'):
v = v() # dependency is a function, call it
upd(v)
return self.m.digest()
def sig_vars(self):
"""
Used by :py:meth:`waflib.Task.Task.signature`, hash :py:attr:`waflib.Task.Task.env` variables/values
:rtype: hash value
"""
bld = self.generator.bld
env = self.env
upd = self.m.update
# dependencies on the environment vars
act_sig = bld.hash_env_vars(env, self.__class__.vars)
upd(act_sig)
# additional variable dependencies, if provided
dep_vars = getattr(self, 'dep_vars', None)
if dep_vars:
upd(bld.hash_env_vars(env, dep_vars))
return self.m.digest()
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 are stored in :py:attr:`waflib.Build.BuildContext.node_deps` and
:py:attr:`waflib.Build.BuildContext.raw_deps` respectively.
"""
def sig_implicit_deps(self):
"""
Used by :py:meth:`waflib.Task.Task.signature` 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. When this occurs, :py:meth:`waflib.Task.Task.signature` is called
once again, and this method will be executed once again, this time calling :py:meth:`waflib.Task.Task.scan`
for searching the dependencies.
:rtype: hash value
"""
bld = self.generator.bld
# get the task signatures from previous runs
key = self.uid()
prev = bld.task_sigs.get((key, 'imp'), [])
# for issue #379
if prev:
try:
if prev == self.compute_sig_implicit_deps():
return prev
except Exception:
# when a file was renamed (IOError usually), 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 x.is_child_of(bld.srcnode):
try:
os.stat(x.abspath())
except OSError:
try:
del x.parent.children[x.name]
except KeyError:
pass
del bld.task_sigs[(key, 'imp')]
raise Errors.TaskRescan('rescan')
# no previous run or the signature of the dependencies has changed, rescan the dependencies
(nodes, names) = self.scan()
if Logs.verbose:
Logs.debug('deps: scanner for %s returned %s %s' % (str(self), str(nodes), str(names)))
# store the dependencies in the cache
bld.node_deps[key] = nodes
bld.raw_deps[key] = names
# might happen
self.are_implicit_nodes_ready()
# recompute the signature and return it
try:
bld.task_sigs[(key, 'imp')] = sig = self.compute_sig_implicit_deps()
except Exception:
if Logs.verbose:
for k in bld.node_deps.get(self.uid(), []):
try:
k.get_bld_sig()
except Exception:
Logs.warn('Missing signature for node %r (may cause rebuilds)' % k)
else:
return sig
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: hash value
:rtype: string
"""
upd = self.m.update
bld = self.generator.bld
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 bld.node_deps.get(self.uid(), []):
upd(k.get_bld_sig())
return self.m.digest()
def are_implicit_nodes_ready(self):
"""
For each node returned by the scanner, see if there is a task behind it, and force the build order
The performance impact on null builds is nearly invisible (1.66s->1.86s), but this is due to
agressive caching (1.86s->28s)
"""
bld = self.generator.bld
try:
cache = bld.dct_implicit_nodes
except AttributeError:
bld.dct_implicit_nodes = cache = {}
try:
dct = cache[bld.cur]
except KeyError:
dct = cache[bld.cur] = {}
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')
def can_retrieve_cache(self):
"""
Used by :py:meth:`waflib.Task.cache_outputs`
Retrieve build nodes from the cache
update the file timestamps to help cleaning the least used entries from the cache
additionally, set an attribute 'cached' to avoid re-creating the same cache files
Suppose there are files in `cache/dir1/file1` and `cache/dir2/file2`:
#. read the timestamp of dir1
#. try to copy the files
#. look at the timestamp again, if it has changed, the data may have been corrupt (cache update by another process)
#. should an exception occur, ignore the data
"""
if not getattr(self, 'outputs', None):
return None
sig = self.signature()
ssig = Utils.to_hex(self.uid()) + Utils.to_hex(sig)
# first try to access the cache folder for the task
dname = os.path.join(self.generator.bld.cache_global, ssig)
try:
t1 = os.stat(dname).st_mtime
except OSError:
return None
for node in self.outputs:
orig = os.path.join(dname, node.name)
try:
shutil.copy2(orig, node.abspath())
# mark the cache file as used recently (modified)
os.utime(orig, None)
except (OSError, IOError):
Logs.debug('task: failed retrieving file')
return None
# is it the same folder?
try:
t2 = os.stat(dname).st_mtime
except OSError:
return None
if t1 != t2:
return None
for node in self.outputs:
node.sig = sig
if self.generator.bld.progress_bar < 1:
self.generator.bld.to_log('restoring from cache %r\n' % node.abspath())
self.cached = True
return True
def put_files_cache(self):
"""
Used by :py:func:`waflib.Task.cache_outputs` to store the build files in the cache
"""
# file caching, if possible
# try to avoid data corruption as much as possible
if getattr(self, 'cached', None):
return None
if not getattr(self, 'outputs', None):
return None
sig = self.signature()
ssig = Utils.to_hex(self.uid()) + Utils.to_hex(sig)
dname = os.path.join(self.generator.bld.cache_global, ssig)
tmpdir = tempfile.mkdtemp(prefix=self.generator.bld.cache_global + os.sep + 'waf')
try:
shutil.rmtree(dname)
except Exception:
pass
try:
for node in self.outputs:
dest = os.path.join(tmpdir, node.name)
shutil.copy2(node.abspath(), dest)
except (OSError, IOError):
try:
shutil.rmtree(tmpdir)
except Exception:
pass
else:
try:
os.rename(tmpdir, dname)
except OSError:
try:
shutil.rmtree(tmpdir)
except Exception:
pass
else:
try:
os.chmod(dname, Utils.O755)
except Exception:
pass
def is_before(t1, t2):
"""
Return 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
:type t1: :py:class:`waflib.Task.TaskBase`
:param t2: task
:type t2: :py:class:`waflib.Task.TaskBase`
"""
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
def set_file_constraints(tasks):
"""
Adds tasks to the task 'run_after' attribute based on the task inputs and outputs
:param tasks: tasks
:type tasks: list of :py:class:`waflib.Task.TaskBase`
"""
ins = Utils.defaultdict(set)
outs = Utils.defaultdict(set)
for x in tasks:
for a in getattr(x, 'inputs', []) + getattr(x, 'dep_nodes', []):
ins[id(a)].add(x)
for a in getattr(x, 'outputs', []):
outs[id(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])
def set_precedence_constraints(tasks):
"""
Add tasks to the task 'run_after' attribute based on the after/before/ext_out/ext_in attributes
:param tasks: tasks
:type tasks: list of :py:class:`waflib.Task.TaskBase`
"""
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
aval = set(cstr_groups[keys[a]])
for x in cstr_groups[keys[b]]:
x.run_after.update(aval)
def funex(c):
"""
Compile a function by 'exec'
: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']
reg_act = re.compile(r"(?P<backslash>\\)|(?P<dollar>\$\$)|(?P<subst>\$\{(?P<var>\w+)(?P<code>.*?)\})", re.M)
def compile_fun_shell(line):
"""
Create a compiled function to execute a process with the shell
WARNING: this method may disappear anytime, so use compile_fun instead
"""
extr = []
def repl(match):
g = match.group
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
parm = []
dvars = []
app = parm.append
for (var, meth) in extr:
if var == 'SRC':
if meth: app('tsk.inputs%s' % meth)
else: app('" ".join([a.path_from(bld.bldnode) for a in tsk.inputs])')
elif var == 'TGT':
if meth: app('tsk.outputs%s' % meth)
else: app('" ".join([a.path_from(bld.bldnode) for a in tsk.outputs])')
elif meth:
if meth.startswith(':'):
m = meth[1:]
if m == 'SRC':
m = '[a.path_from(bld.bldnode) for a in tsk.inputs]'
elif m == 'TGT':
m = '[a.path_from(bld.bldnode) for a in tsk.outputs]'
elif m[:3] not in ('tsk', 'gen', 'bld'):
dvars.extend([var, meth[1:]])
m = '%r' % m
app('" ".join(tsk.colon(%r, %s))' % (var, m))
else:
app('%s%s' % (var, meth))
else:
if not var in dvars: dvars.append(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)
def compile_fun_noshell(line):
"""
Create a compiled function to execute a process without the shell
WARNING: this method may disappear anytime, so use compile_fun instead
"""
extr = []
def repl(match):
g = match.group
if g('dollar'): return "$"
elif g('subst'): extr.append((g('var'), g('code'))); return "<<|@|>>"
return None
line2 = reg_act.sub(repl, line)
params = line2.split('<<|@|>>')
assert(extr)
buf = []
dvars = []
app = buf.append
for x in range(len(extr)):
params[x] = params[x].strip()
if params[x]:
app("lst.extend(%r)" % params[x].split())
(var, meth) = extr[x]
if var == 'SRC':
if meth: app('lst.append(tsk.inputs%s)' % meth)
else: app("lst.extend([a.path_from(bld.bldnode) for a in tsk.inputs])")
elif var == 'TGT':
if meth: app('lst.append(tsk.outputs%s)' % meth)
else: app("lst.extend([a.path_from(bld.bldnode) for a in tsk.outputs])")
elif meth:
if meth.startswith(':'):
m = meth[1:]
if m == 'SRC':
m = '[a.path_from(bld.bldnode) for a in tsk.inputs]'
elif m == 'TGT':
m = '[a.path_from(bld.bldnode) for a in tsk.outputs]'
elif m[:3] not in ('tsk', 'gen', 'bld'):
dvars.extend([var, m])
m = '%r' % m
app('lst.extend(tsk.colon(%r, %s))' % (var, m))
else:
app('lst.extend(gen.to_list(%s%s))' % (var, meth))
else:
app('lst.extend(to_list(env[%r]))' % var)
if not var in dvars: dvars.append(var)
if extr:
if params[-1]:
app("lst.extend(%r)" % params[-1].split())
fun = COMPILE_TEMPLATE_NOSHELL % "\n\t".join(buf)
Logs.debug('action: %s' % fun.strip().splitlines())
return (funex(fun), dvars)
def compile_fun(line, shell=False):
"""
Parse a string expression such as "${CC} ${SRC} -o ${TGT}" and return a pair containing:
* the function created (compiled) for use as :py:meth:`waflib.Task.TaskBase.run`
* the list of variables that imply a dependency from self.env
for example::
from waflib.Task import compile_fun
compile_fun('cxx', '${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 (order)
The reserved keywords *TGT* and *SRC* represent the task input and output nodes
"""
if line.find('<') > 0 or line.find('>') > 0 or line.find('&&') > 0:
shell = True
if shell:
return compile_fun_shell(line)
else:
return compile_fun_noshell(line)
def task_factory(name, func=None, vars=None, color='GREEN', ext_in=[], ext_out=[], before=[], after=[], shell=False, scan=None):
"""
Deprecated. Return a new task subclass with the function ``run`` compiled from the line given.
Provided for compatibility with waf 1.4-1.5, when we did not have the metaclass to register new classes (will be removed in Waf 1.8)
: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,
'ext_in': Utils.to_list(ext_in),
'ext_out': Utils.to_list(ext_out),
'before': Utils.to_list(before),
'after': Utils.to_list(after),
'shell': shell,
'scan': scan,
}
if isinstance(func, str):
params['run_str'] = func
else:
params['run'] = func
cls = type(Task)(name, (Task,), params)
global classes
classes[name] = cls
return cls
def always_run(cls):
"""
Task class decorator
Set all task instances of this class to be executed whenever a build is started
The task signature is calculated, but the result of the comparation between
task signatures is bypassed
"""
old = cls.runnable_status
def always(self):
ret = old(self)
if ret == SKIP_ME:
ret = RUN_ME
return ret
cls.runnable_status = always
return cls
def update_outputs(cls):
"""
Task class decorator
If you want to create files in the source directory. For example, to keep *foo.txt* in the source
directory, create it first and declare::
def build(bld):
bld(rule='cp ${SRC} ${TGT}', source='wscript', target='foo.txt', update_outputs=True)
"""
old_post_run = cls.post_run
def post_run(self):
old_post_run(self)
for node in self.outputs:
node.sig = Utils.h_file(node.abspath())
self.generator.bld.task_sigs[node.abspath()] = self.uid() # issue #1017
cls.post_run = post_run
old_runnable_status = cls.runnable_status
def runnable_status(self):
status = old_runnable_status(self)
if status != RUN_ME:
return status
try:
# by default, we check that the output nodes have the signature of the task
# perform a second check, returning 'SKIP_ME' as we are expecting that
# the signatures do not match
bld = self.generator.bld
prev_sig = bld.task_sigs[self.uid()]
if prev_sig == self.signature():
for x in self.outputs:
if not x.sig or bld.task_sigs[x.abspath()] != self.uid():
return RUN_ME
return SKIP_ME
except KeyError:
pass
except IndexError:
pass
except AttributeError:
pass
return RUN_ME
cls.runnable_status = runnable_status
return cls