Accept functools.partial() as a task rule #1862 (#1865)

Accept functools.partial() as task generator rules #1862

waflib/TaskGen.py

@@ -11,6 +11,7 @@ is deferred. To achieve this, various methods are called from the method "apply"
 """
 
 import copy, re, os
+from functools import partial
 from waflib import Task, Utils, Logs, Errors, ConfigSet, Node
 
 feats = Utils.defaultdict(set)
@@ -634,6 +635,13 @@ def process_rule(self):
 	if getattr(self, 'cwd', None):
 		tsk.cwd = self.cwd
 
+	if type(tsk.run) is partial:
+		# Python documentation says: "partial objects defined in classes
+		# behave like static methods and do not transform into bound
+		# methods during instance attribute look-up."
+		tsk.run = partial(tsk.run, tsk)
+
+
 @feature('seq')
 def sequence_order(self):
 	"""

waflib/Utils.py

@@ -10,6 +10,8 @@ through Python versions 2.5 to 3.X and across different platforms (win32, linux,
 """
 
 import os, sys, errno, traceback, inspect, re, datetime, platform, base64, signal
+import functools
+
 try:
 	import cPickle
 except ImportError:
@@ -604,6 +606,10 @@ def h_cmd(ins):
 	elif isinstance(ins, list) or isinstance(ins, tuple):
 		# or a list of functions/strings
 		ret = str([h_cmd(x) for x in ins])
+	elif isinstance(ins, functools.partial):
+		ret = str([h_list(ins.args),
+		           h_list(tuple(ins.keywords.items())),
+		           h_fun(ins.func)])
 	else:
 		# or just a python function
 		ret = str(h_fun(ins))