midori/waf-modules/wafadmin/Task.py

#! /usr/bin/env python
# encoding: utf-8
import sys
if sys.hexversion < 0x020400f0: from sets import Set as set
import os,shutil,sys,re,random,datetime,tempfile,shlex
from Utils import md5
import Build,Runner,Utils,Node,Logs,Options
from Logs import debug,warn,error
from Constants import*
algotype=NORMAL
COMPILE_TEMPLATE_SHELL='''
def f(task):
	env = task.env
	wd = getattr(task, 'cwd', None)
	p = env.get_flat
	cmd = \'\'\' %s \'\'\' % s
	return task.exec_command(cmd, cwd=wd)
'''
COMPILE_TEMPLATE_NOSHELL='''
def f(task):
	env = task.env
	wd = getattr(task, 'cwd', None)
	def to_list(xx):
		if isinstance(xx, str): return [xx]
		return xx
	lst = []
	%s
	lst = [x for x in lst if x]
	return task.exec_command(lst, cwd=wd)
'''
file_deps=Utils.nada
class TaskManager(object):
	def __init__(self):
		self.groups=[]
		self.tasks_done=[]
		self.current_group=0
		self.groups_names={}
	def group_name(self,g):
		if not isinstance(g,TaskGroup):
			g=self.groups[g]
		for x in self.groups_names:
			if id(self.groups_names[x])==id(g):
				return x
		return''
	def group_idx(self,tg):
		se=id(tg)
		for i in range(len(self.groups)):
			g=self.groups[i]
			for t in g.tasks_gen:
				if id(t)==se:
					return i
		return None
	def get_next_set(self):
		ret=None
		while not ret and self.current_group<len(self.groups):
			ret=self.groups[self.current_group].get_next_set()
			if ret:return ret
			else:
				self.groups[self.current_group].process_install()
				self.current_group+=1
		return(None,None)
	def add_group(self,name=None,set=True):
		g=TaskGroup()
		if name and name in self.groups_names:
			error('add_group: name %s already present'%name)
		self.groups_names[name]=g
		self.groups.append(g)
		if set:
			self.current_group=len(self.groups)-1
	def set_group(self,idx):
		if isinstance(idx,str):
			g=self.groups_names[idx]
			for x in xrange(len(self.groups)):
				if id(g)==id(self.groups[x]):
					self.current_group=x
		else:
			self.current_group=idx
	def add_task_gen(self,tgen):
		if not self.groups:self.add_group()
		self.groups[self.current_group].tasks_gen.append(tgen)
	def add_task(self,task):
		if not self.groups:self.add_group()
		self.groups[self.current_group].tasks.append(task)
	def total(self):
		total=0
		if not self.groups:return 0
		for group in self.groups:
			total+=len(group.tasks)
		return total
	def add_finished(self,tsk):
		self.tasks_done.append(tsk)
		bld=tsk.generator.bld
		if bld.is_install:
			f=None
			if'install'in tsk.__dict__:
				f=tsk.__dict__['install']
				if f:f(tsk)
			else:
				tsk.install()
class TaskGroup(object):
	def __init__(self):
		self.tasks=[]
		self.tasks_gen=[]
		self.cstr_groups=Utils.DefaultDict(list)
		self.cstr_order=Utils.DefaultDict(set)
		self.temp_tasks=[]
		self.ready=0
		self.post_funs=[]
	def reset(self):
		for x in self.cstr_groups:
			self.tasks+=self.cstr_groups[x]
		self.tasks=self.temp_tasks+self.tasks
		self.temp_tasks=[]
		self.cstr_groups=Utils.DefaultDict(list)
		self.cstr_order=Utils.DefaultDict(set)
		self.ready=0
	def process_install(self):
		for(f,k,kw)in self.post_funs:
			f(*k,**kw)
	def prepare(self):
		self.ready=1
		file_deps(self.tasks)
		self.make_cstr_groups()
		self.extract_constraints()
	def get_next_set(self):
		global algotype
		if algotype==NORMAL:
			tasks=self.tasks_in_parallel()
			maxj=MAXJOBS
		elif algotype==JOBCONTROL:
			(maxj,tasks)=self.tasks_by_max_jobs()
		elif algotype==MAXPARALLEL:
			tasks=self.tasks_with_inner_constraints()
			maxj=MAXJOBS
		else:
			raise Utils.WafError("unknown algorithm type %s"%(algotype))
		if not tasks:return()
		return(maxj,tasks)
	def make_cstr_groups(self):
		self.cstr_groups=Utils.DefaultDict(list)
		for x in self.tasks:
			h=x.hash_constraints()
			self.cstr_groups[h].append(x)
	def set_order(self,a,b):
		self.cstr_order[a].add(b)
	def compare_exts(self,t1,t2):
		x="ext_in"
		y="ext_out"
		in_=t1.attr(x,())
		out_=t2.attr(y,())
		for k in in_:
			if k in out_:
				return-1
		in_=t2.attr(x,())
		out_=t1.attr(y,())
		for k in in_:
			if k in out_:
				return 1
		return 0
	def compare_partial(self,t1,t2):
		m="after"
		n="before"
		name=t2.__class__.__name__
		if name in Utils.to_list(t1.attr(m,())):return-1
		elif name in Utils.to_list(t1.attr(n,())):return 1
		name=t1.__class__.__name__
		if name in Utils.to_list(t2.attr(m,())):return 1
		elif name in Utils.to_list(t2.attr(n,())):return-1
		return 0
	def extract_constraints(self):
		keys=self.cstr_groups.keys()
		max=len(keys)
		for i in xrange(max):
			t1=self.cstr_groups[keys[i]][0]
			for j in xrange(i+1,max):
				t2=self.cstr_groups[keys[j]][0]
				val=(self.compare_exts(t1,t2)or self.compare_partial(t1,t2))
				if val>0:
					self.set_order(keys[i],keys[j])
				elif val<0:
					self.set_order(keys[j],keys[i])
	def tasks_in_parallel(self):
		if not self.ready:self.prepare()
		keys=self.cstr_groups.keys()
		unconnected=[]
		remainder=[]
		for u in keys:
			for k in self.cstr_order.values():
				if u in k:
					remainder.append(u)
					break
			else:
				unconnected.append(u)
		toreturn=[]
		for y in unconnected:
			toreturn.extend(self.cstr_groups[y])
		for y in unconnected:
			try:self.cstr_order.__delitem__(y)
			except KeyError:pass
			self.cstr_groups.__delitem__(y)
		if not toreturn and remainder:
			raise Utils.WafError("circular order constraint detected %r"%remainder)
		return toreturn
	def tasks_by_max_jobs(self):
		if not self.ready:self.prepare()
		if not self.temp_tasks:self.temp_tasks=self.tasks_in_parallel()
		if not self.temp_tasks:return(None,None)
		maxjobs=MAXJOBS
		ret=[]
		remaining=[]
		for t in self.temp_tasks:
			m=getattr(t,"maxjobs",getattr(self.__class__,"maxjobs",MAXJOBS))
			if m>maxjobs:
				remaining.append(t)
			elif m<maxjobs:
				remaining+=ret
				ret=[t]
				maxjobs=m
			else:
				ret.append(t)
		self.temp_tasks=remaining
		return(maxjobs,ret)
	def tasks_with_inner_constraints(self):
		if not self.ready:self.prepare()
		if getattr(self,"done",None):return None
		for p in self.cstr_order:
			for v in self.cstr_order[p]:
				for m in self.cstr_groups[p]:
					for n in self.cstr_groups[v]:
						n.set_run_after(m)
		self.cstr_order=Utils.DefaultDict(set)
		self.cstr_groups=Utils.DefaultDict(list)
		self.done=1
		return self.tasks[:]
class store_task_type(type):
	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!='TaskBase':
			TaskBase.classes[name]=cls
class TaskBase(object):
	__metaclass__=store_task_type
	color="GREEN"
	maxjobs=MAXJOBS
	classes={}
	stat=None
	def __init__(self,*k,**kw):
		self.hasrun=NOT_RUN
		try:
			self.generator=kw['generator']
		except KeyError:
			self.generator=self
			self.bld=Build.bld
		if kw.get('normal',1):
			self.generator.bld.task_manager.add_task(self)
	def __repr__(self):
		return'\n\t{task: %s %s}'%(self.__class__.__name__,str(getattr(self,"fun","")))
	def __str__(self):
		if hasattr(self,'fun'):
			return'executing: %s\n'%self.fun.__name__
		return self.__class__.__name__+'\n'
	def exec_command(self,*k,**kw):
		if self.env['env']:
			kw['env']=self.env['env']
		return self.generator.bld.exec_command(*k,**kw)
	def runnable_status(self):
		return RUN_ME
	def can_retrieve_cache(self):
		return False
	def call_run(self):
		if self.can_retrieve_cache():
			return 0
		return self.run()
	def run(self):
		if hasattr(self,'fun'):
			return self.fun(self)
		return 0
	def post_run(self):
		pass
	def display(self):
		col1=Logs.colors(self.color)
		col2=Logs.colors.NORMAL
		if Options.options.progress_bar==1:
			return self.generator.bld.progress_line(self.position[0],self.position[1],col1,col2)
		if Options.options.progress_bar==2:
			ela=Utils.get_elapsed_time(self.generator.bld.ini)
			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'%(self.position[1],self.position[0],ins,outs,ela)
		total=self.position[1]
		n=len(str(total))
		fs='[%%%dd/%%%dd] %%s%%s%%s'%(n,n)
		return fs%(self.position[0],self.position[1],col1,str(self),col2)
	def attr(self,att,default=None):
		ret=getattr(self,att,self)
		if ret is self:return getattr(self.__class__,att,default)
		return ret
	def hash_constraints(self):
		a=self.attr
		sum=hash((self.__class__.__name__,str(a('before','')),str(a('after','')),str(a('ext_in','')),str(a('ext_out','')),self.__class__.maxjobs))
		return sum
	def format_error(self):
		if getattr(self,"err_msg",None):
			return self.err_msg
		elif self.hasrun==CRASHED:
			try:
				return" -> task failed (err #%d): %r"%(self.err_code,self)
			except AttributeError:
				return" -> task failed: %r"%self
		elif self.hasrun==MISSING:
			return" -> missing files: %r"%self
		else:
			return''
	def install(self):
		bld=self.generator.bld
		d=self.attr('install')
		if self.attr('install_path'):
			lst=[a.relpath_gen(bld.srcnode)for a in self.outputs]
			perm=self.attr('chmod',O644)
			if self.attr('src'):
				lst+=[a.relpath_gen(bld.srcnode)for a in self.inputs]
			if self.attr('filename'):
				dir=self.install_path.rstrip(os.sep)+os.sep+self.attr('filename')
				bld.install_as(dir,lst[0],self.env,perm)
			else:
				bld.install_files(self.install_path,lst,self.env,perm)
class Task(TaskBase):
	vars=[]
	def __init__(self,env,**kw):
		TaskBase.__init__(self,**kw)
		self.env=env
		self.inputs=[]
		self.outputs=[]
		self.dep_nodes=[]
		self.run_after=[]
	def __str__(self):
		env=self.env
		src_str=' '.join([a.nice_path(env)for a in self.inputs])
		tgt_str=' '.join([a.nice_path(env)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):
		return"".join(['\n\t{task: ',self.__class__.__name__," ",",".join([x.name for x in self.inputs])," -> ",",".join([x.name for x in self.outputs]),'}'])
	def unique_id(self):
		try:
			return self.uid
		except AttributeError:
			m=md5()
			up=m.update
			up(self.__class__.__name__)
			up(self.env.variant())
			p=None
			for x in self.inputs+self.outputs:
				if p!=x.parent.id:
					p=x.parent.id
					up(x.parent.abspath())
				up(x.name)
			self.uid=m.digest()
			return self.uid
	def set_inputs(self,inp):
		if isinstance(inp,list):self.inputs+=inp
		else:self.inputs.append(inp)
	def set_outputs(self,out):
		if isinstance(out,list):self.outputs+=out
		else:self.outputs.append(out)
	def set_run_after(self,task):
		assert isinstance(task,TaskBase)
		self.run_after.append(task)
	def add_file_dependency(self,filename):
		node=self.generator.bld.path.find_resource(filename)
		self.dep_nodes.append(node)
	def signature(self):
		try:return self.cache_sig[0]
		except AttributeError:pass
		self.m=md5()
		exp_sig=self.sig_explicit_deps()
		var_sig=self.sig_vars()
		imp_sig=SIG_NIL
		if self.scan:
			try:
				imp_sig=self.sig_implicit_deps()
			except ValueError:
				return self.signature()
		ret=self.m.digest()
		self.cache_sig=(ret,exp_sig,imp_sig,var_sig)
		return ret
	def runnable_status(self):
		if self.inputs and(not self.outputs):
			if not getattr(self.__class__,'quiet',None):
				warn("invalid task (no inputs OR outputs): override in a Task subclass or set the attribute 'quiet' %r"%self)
		for t in self.run_after:
			if not t.hasrun:
				return ASK_LATER
		env=self.env
		bld=self.generator.bld
		new_sig=self.signature()
		key=self.unique_id()
		try:
			prev_sig=bld.task_sigs[key][0]
		except KeyError:
			debug("task: task %r must run as it was never run before or the task code changed",self)
			return RUN_ME
		for node in self.outputs:
			variant=node.variant(env)
			try:
				if bld.node_sigs[variant][node.id]!=new_sig:
					return RUN_ME
			except KeyError:
				debug("task: task %r must run as the output nodes do not exist",self)
				return RUN_ME
		if Logs.verbose:self.debug_why(bld.task_sigs[key])
		if new_sig!=prev_sig:
			return RUN_ME
		return SKIP_ME
	def post_run(self):
		bld=self.generator.bld
		env=self.env
		sig=self.signature()
		ssig=sig.encode('hex')
		variant=env.variant()
		for node in self.outputs:
			try:
				os.stat(node.abspath(env))
			except OSError:
				self.hasrun=MISSING
				self.err_msg='-> missing file: %r'%node.abspath(env)
				raise Utils.WafError
			bld.node_sigs[variant][node.id]=sig
		bld.task_sigs[self.unique_id()]=self.cache_sig
		if not Options.cache_global or Options.options.nocache or not self.outputs:
			return None
		if getattr(self,'cached',None):
			return None
		dname=os.path.join(Options.cache_global,ssig)
		tmpdir=tempfile.mkdtemp(prefix=Options.cache_global+os.sep+'waf')
		try:
			shutil.rmtree(dname)
		except:
			pass
		try:
			i=0
			for node in self.outputs:
				variant=node.variant(env)
				dest=os.path.join(tmpdir,str(i)+node.name)
				shutil.copy2(node.abspath(env),dest)
				i+=1
		except(OSError,IOError):
			try:
				shutil.rmtree(tmpdir)
			except:
				pass
		else:
			try:
				os.rename(tmpdir,dname)
			except OSError:
				try:
					shutil.rmtree(tmpdir)
				except:
					pass
			else:
				try:
					os.chmod(dname,O755)
				except:
					pass
	def can_retrieve_cache(self):
		if not Options.cache_global or Options.options.nocache or not self.outputs:
			return None
		env=self.env
		sig=self.signature()
		ssig=sig.encode('hex')
		dname=os.path.join(Options.cache_global,ssig)
		try:
			t1=os.stat(dname).st_mtime
		except OSError:
			return None
		i=0
		for node in self.outputs:
			variant=node.variant(env)
			orig=os.path.join(dname,str(i)+node.name)
			try:
				shutil.copy2(orig,node.abspath(env))
				os.utime(orig,None)
			except(OSError,IOError):
				debug('task: failed retrieving file')
				return None
			i+=1
		try:
			t2=os.stat(dname).st_mtime
		except OSError:
			return None
		if t1!=t2:
			return None
		for node in self.outputs:
			self.generator.bld.node_sigs[variant][node.id]=sig
			if Options.options.progress_bar<1:
				self.generator.bld.printout('restoring from cache %r\n'%node.bldpath(env))
		self.cached=True
		return 1
	def debug_why(self,old_sigs):
		new_sigs=self.cache_sig
		def v(x):
			return x.encode('hex')
		debug("Task %r",self)
		msgs=['Task must run','* Source file or manual dependency','* Implicit dependency','* Environment variable']
		tmp='task: -> %s: %s %s'
		for x in xrange(len(msgs)):
			if(new_sigs[x]!=old_sigs[x]):
				debug(tmp,msgs[x],v(old_sigs[x]),v(new_sigs[x]))
	def sig_explicit_deps(self):
		bld=self.generator.bld
		up=self.m.update
		for x in self.inputs+getattr(self,'dep_nodes',[]):
			if not x.parent.id in bld.cache_scanned_folders:
				bld.rescan(x.parent)
			variant=x.variant(self.env)
			try:
				up(bld.node_sigs[variant][x.id])
			except KeyError:
				raise Utils.WafError('Missing node signature for %r (required by %r)'%(x,self))
		if bld.deps_man:
			additional_deps=bld.deps_man
			for x in self.inputs+self.outputs:
				try:
					d=additional_deps[x.id]
				except KeyError:
					continue
				for v in d:
					if isinstance(v,Node.Node):
						bld.rescan(v.parent)
						variant=v.variant(self.env)
						try:
							v=bld.node_sigs[variant][v.id]
						except KeyError:
							raise Utils.WafError('Missing node signature for %r (required by %r)'%(v,self))
					elif hasattr(v,'__call__'):
						v=v()
					up(v)
		for x in self.dep_nodes:
			v=bld.node_sigs[x.variant(self.env)][x.id]
			up(v)
		return self.m.digest()
	def sig_vars(self):
		bld=self.generator.bld
		env=self.env
		act_sig=bld.hash_env_vars(env,self.__class__.vars)
		self.m.update(act_sig)
		dep_vars=getattr(self,'dep_vars',None)
		if dep_vars:
			self.m.update(bld.hash_env_vars(env,dep_vars))
		return self.m.digest()
	scan=None
	def sig_implicit_deps(self):
		bld=self.generator.bld
		key=self.unique_id()
		prev_sigs=bld.task_sigs.get(key,())
		if prev_sigs:
			try:
				if prev_sigs[2]==self.compute_sig_implicit_deps():
					return prev_sigs[2]
			except(KeyError,OSError):
				pass
			del bld.task_sigs[key]
			raise ValueError('rescan')
		(nodes,names)=self.scan()
		if Logs.verbose:
			debug('deps: scanner for %s returned %s %s',str(self),str(nodes),str(names))
		bld.node_deps[key]=nodes
		bld.raw_deps[key]=names
		try:
			sig=self.compute_sig_implicit_deps()
		except KeyError:
			try:
				nodes=[]
				for k in bld.node_deps.get(self.unique_id(),[]):
					if k.id&3==2:
						if not k.id in bld.node_sigs[0]:
							nodes.append(k)
					else:
						if not k.id in bld.node_sigs[self.env.variant()]:
							nodes.append(k)
			except:
				nodes='?'
			raise Utils.WafError('Missing node signature for %r (for implicit dependencies %r)'%(nodes,self))
		return sig
	def compute_sig_implicit_deps(self):
		upd=self.m.update
		bld=self.generator.bld
		tstamp=bld.node_sigs
		env=self.env
		for k in bld.node_deps.get(self.unique_id(),[]):
			if not k.parent.id in bld.cache_scanned_folders:
				bld.rescan(k.parent)
			if k.id&3==2:
				upd(tstamp[0][k.id])
			else:
				upd(tstamp[env.variant()][k.id])
		return self.m.digest()
def funex(c):
	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(name,line):
	extr=[]
	def repl(match):
		g=match.group
		if g('dollar'):return"$"
		elif g('backslash'):return'\\\\'
		elif g('subst'):extr.append((g('var'),g('code')));return"%s"
		return None
	line=reg_act.sub(repl,line)or line
	parm=[]
	dvars=[]
	app=parm.append
	for(var,meth)in extr:
		if var=='SRC':
			if meth:app('task.inputs%s'%meth)
			else:app('" ".join([a.srcpath(env) for a in task.inputs])')
		elif var=='TGT':
			if meth:app('task.outputs%s'%meth)
			else:app('" ".join([a.bldpath(env) for a in task.outputs])')
		else:
			if not var in dvars:dvars.append(var)
			app("p('%s')"%var)
	if parm:parm="%% (%s) "%(',\n\t\t'.join(parm))
	else:parm=''
	c=COMPILE_TEMPLATE_SHELL%(line,parm)
	debug('action: %s',c)
	return(funex(c),dvars)
def compile_fun_noshell(name,line):
	extr=[]
	def repl(match):
		g=match.group
		if g('dollar'):return"$"
		elif g('subst'):extr.append((g('var'),g('code')));return"<<|@|>>"
		return None
	line2=reg_act.sub(repl,line)
	params=line2.split('<<|@|>>')
	buf=[]
	dvars=[]
	app=buf.append
	for x in xrange(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(task.inputs%s)'%meth)
			else:app("lst.extend([a.srcpath(env) for a in task.inputs])")
		elif var=='TGT':
			if meth:app('lst.append(task.outputs%s)'%meth)
			else:app("lst.extend([a.bldpath(env) for a in task.outputs])")
		else:
			app('lst.extend(to_list(env[%r]))'%var)
			if not var in dvars:dvars.append(var)
	if params[-1]:
		app("lst.extend(%r)"%shlex.split(params[-1]))
	fun=COMPILE_TEMPLATE_NOSHELL%"\n\t".join(buf)
	debug('action: %s',fun)
	return(funex(fun),dvars)
def compile_fun(name,line,shell=None):
	if line.find('<')>0 or line.find('>')>0 or line.find('&&')>0:
		shell=True
	if shell is None:
		if sys.platform=='win32':
			shell=False
		else:
			shell=True
	if shell:
		return compile_fun_shell(name,line)
	else:
		return compile_fun_noshell(name,line)
def simple_task_type(name,line,color='GREEN',vars=[],ext_in=[],ext_out=[],before=[],after=[],shell=None):
	(fun,dvars)=compile_fun(name,line,shell)
	fun.code=line
	return task_type_from_func(name,fun,vars or dvars,color,ext_in,ext_out,before,after)
def task_type_from_func(name,func,vars=[],color='GREEN',ext_in=[],ext_out=[],before=[],after=[]):
	params={'run':func,'vars':vars,'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),}
	cls=type(Task)(name,(Task,),params)
	TaskBase.classes[name]=cls
	return cls
def always_run(cls):
	old=cls.runnable_status
	def always(self):
		ret=old(self)
		if ret==SKIP_ME:
			return RUN_ME
		return ret
	cls.runnable_status=always
def update_outputs(cls):
	old_post_run=cls.post_run
	def post_run(self):
		old_post_run(self)
		bld=self.generator.bld
		for output in self.outputs:
			bld.node_sigs[self.env.variant()][output.id]=Utils.h_file(output.abspath(self.env))
	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:
			bld=self.outputs[0].__class__.bld
			new_sig=self.signature()
			prev_sig=bld.task_sigs[self.unique_id()][0]
			if prev_sig==new_sig:
				for x in self.outputs:
					if not x.id in bld.node_sigs[self.env.variant()]:
						return RUN_ME
				return SKIP_ME
		except KeyError:
			pass
		except IndexError:
			pass
		return RUN_ME
	cls.runnable_status=runnable_status
def extract_outputs(tasks):
	v={}
	for x in tasks:
		try:
			(ins,outs)=v[x.env.variant()]
		except KeyError:
			ins={}
			outs={}
			v[x.env.variant()]=(ins,outs)
		for a in getattr(x,'inputs',[]):
			try:ins[a.id].append(x)
			except KeyError:ins[a.id]=[x]
		for a in getattr(x,'outputs',[]):
			try:outs[a.id].append(x)
			except KeyError:outs[a.id]=[x]
	for(ins,outs)in v.values():
		links=set(ins.iterkeys()).intersection(outs.iterkeys())
		for k in links:
			for a in ins[k]:
				for b in outs[k]:
					a.set_run_after(b)
def extract_deps(tasks):
	extract_outputs(tasks)
	out_to_task={}
	for x in tasks:
		v=x.env.variant()
		try:
			lst=x.outputs
		except AttributeError:
			pass
		else:
			for node in lst:
				out_to_task[(v,node.id)]=x
	dep_to_task={}
	for x in tasks:
		try:
			x.signature()
		except:
			pass
		v=x.env.variant()
		key=x.unique_id()
		for k in x.generator.bld.node_deps.get(x.unique_id(),[]):
			try:dep_to_task[(v,k.id)].append(x)
			except KeyError:dep_to_task[(v,k.id)]=[x]
	deps=set(dep_to_task.keys()).intersection(set(out_to_task.keys()))
	for idx in deps:
		for k in dep_to_task[idx]:
			k.set_run_after(out_to_task[idx])
	for x in tasks:
		try:
			delattr(x,'cache_sig')
		except AttributeError:
			pass