Imported Upstream version 1.2.0.d20091224upstream/1.2.0.d20091224

1 files changed, 1138 insertions, 0 deletions

diff --git a/src/engine/SCons/TaskmasterTests.py b/src/engine/SCons/TaskmasterTests.py
new file mode 100644
index 0000000..cef256c
--- /dev/null
+++ b/src/engine/SCons/TaskmasterTests.py
@@ -0,0 +1,1138 @@
+#
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__revision__ = "src/engine/SCons/TaskmasterTests.py 4577 2009/12/27 19:44:43 scons"
+
+import copy
+import sys
+import unittest
+
+import SCons.Taskmaster
+import SCons.Errors
+
+
+built_text = None
+cache_text = []
+visited_nodes = []
+executed = None
+scan_called = 0
+
+class Node:
+    def __init__(self, name, kids = [], scans = []):
+        self.name = name
+        self.kids = kids
+        self.scans = scans
+        self.cached = 0
+        self.scanned = 0
+        self.scanner = None
+        self.targets = [self]
+        self.prerequisites = []
+        class Builder:
+            def targets(self, node):
+                return node.targets
+        self.builder = Builder()
+        self.bsig = None
+        self.csig = None
+        self.state = SCons.Node.no_state
+        self.prepared = None
+        self.ref_count = 0
+        self.waiting_parents = set()
+        self.waiting_s_e = set()
+        self.side_effect = 0
+        self.side_effects = []
+        self.alttargets = []
+        self.postprocessed = None
+        self._bsig_val = None
+        self._current_val = 0
+        self.always_build = None
+
+    def disambiguate(self):
+        return self
+
+    def push_to_cache(self):
+        pass
+
+    def retrieve_from_cache(self):
+        global cache_text
+        if self.cached:
+            cache_text.append(self.name + " retrieved")
+        return self.cached
+
+    def make_ready(self):
+        pass
+
+    def prepare(self):
+        self.prepared = 1
+
+    def build(self):
+        global built_text
+        built_text = self.name + " built"
+
+    def built(self):
+        global built_text
+        if not self.cached:
+            built_text = built_text + " really"
+
+    def has_builder(self):
+        return not self.builder is None
+
+    def is_derived(self):
+        return self.has_builder or self.side_effect
+
+    def alter_targets(self):
+        return self.alttargets, None
+
+    def visited(self):
+        global visited_nodes
+        visited_nodes.append(self.name)
+
+    def children(self):
+        if not self.scanned:
+            self.scan()
+            self.scanned = 1
+        return self.kids
+
+    def scan(self):
+        global scan_called
+        scan_called = scan_called + 1
+        self.kids = self.kids + self.scans
+        self.scans = []
+
+    def scanner_key(self):
+        return self.name
+
+    def add_to_waiting_parents(self, node):
+        wp = self.waiting_parents
+        if node in wp:
+            return 0
+        wp.add(node)
+        return 1
+
+    def get_state(self):
+        return self.state
+
+    def set_state(self, state):
+        self.state = state
+
+    def set_bsig(self, bsig):
+        self.bsig = bsig
+
+    def set_csig(self, csig):
+        self.csig = csig
+
+    def store_csig(self):
+        pass
+
+    def store_bsig(self):
+        pass
+
+    def is_pseudo_derived(self):
+        pass
+
+    def is_up_to_date(self):
+        return self._current_val
+    
+    def depends_on(self, nodes):
+        for node in nodes:
+            if node in self.kids:
+                return 1
+        return 0
+
+    def __str__(self):
+        return self.name
+
+    def postprocess(self):
+        self.postprocessed = 1
+        self.waiting_parents = set()
+
+    def get_executor(self):
+        if not hasattr(self, 'executor'):
+            class Executor:
+                def prepare(self):
+                    pass
+                def get_action_targets(self):
+                    return self.targets
+                def get_all_targets(self):
+                    return self.targets
+                def get_all_children(self):
+                    result = []
+                    for node in self.targets:
+                        result.extend(node.children())
+                    return result
+                def get_all_prerequisites(self):
+                    return []
+                def get_action_side_effects(self):
+                    return []
+            self.executor = Executor()
+            self.executor.targets = self.targets
+        return self.executor
+
+class OtherError(Exception):
+    pass
+
+class MyException(Exception):
+    pass
+
+
+class TaskmasterTestCase(unittest.TestCase):
+
+    def test_next_task(self):
+        """Test fetching the next task
+        """
+        global built_text
+
+        n1 = Node("n1")
+        tm = SCons.Taskmaster.Taskmaster([n1, n1])
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        t = tm.next_task()
+        assert t is None
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1, n2])
+
+        tm = SCons.Taskmaster.Taskmaster([n3])
+
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n1 built", built_text
+        t.executed()
+        t.postprocess()
+
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n2 built", built_text
+        t.executed()
+        t.postprocess()
+
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n3 built", built_text
+        t.executed()
+        t.postprocess()
+
+        assert tm.next_task() is None
+
+        built_text = "up to date: "
+        top_node = n3
+
+        class MyTask(SCons.Taskmaster.Task):
+            def execute(self):
+                global built_text
+                if self.targets[0].get_state() == SCons.Node.up_to_date:
+                    if self.top:
+                        built_text = self.targets[0].name + " up-to-date top"
+                    else:
+                        built_text = self.targets[0].name + " up-to-date"
+                else:
+                    self.targets[0].build()
+
+        n1.set_state(SCons.Node.no_state)
+        n1._current_val = 1
+        n2.set_state(SCons.Node.no_state)
+        n2._current_val = 1
+        n3.set_state(SCons.Node.no_state)
+        n3._current_val = 1
+        tm = SCons.Taskmaster.Taskmaster(targets = [n3], tasker = MyTask)
+
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n1 up-to-date", built_text
+        t.executed()
+        t.postprocess()
+
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n2 up-to-date", built_text
+        t.executed()
+        t.postprocess()
+
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n3 up-to-date top", built_text
+        t.executed()
+        t.postprocess()
+
+        assert tm.next_task() is None
+
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1, n2])
+        n4 = Node("n4")
+        n5 = Node("n5", [n3, n4])
+        tm = SCons.Taskmaster.Taskmaster([n5])
+
+        t1 = tm.next_task()
+        assert t1.get_target() == n1
+
+        t2 = tm.next_task()
+        assert t2.get_target() == n2
+
+        t4 = tm.next_task()
+        assert t4.get_target() == n4
+        t4.executed()
+        t4.postprocess()
+
+        t1.executed()
+        t1.postprocess()
+        t2.executed()
+        t2.postprocess()
+        t3 = tm.next_task()
+        assert t3.get_target() == n3
+
+        t3.executed()
+        t3.postprocess()
+        t5 = tm.next_task()
+        assert t5.get_target() == n5, t5.get_target()
+        t5.executed()
+        t5.postprocess()
+
+        assert tm.next_task() is None
+
+
+        n4 = Node("n4")
+        n4.set_state(SCons.Node.executed)
+        tm = SCons.Taskmaster.Taskmaster([n4])
+        assert tm.next_task() is None
+
+        n1 = Node("n1")
+        n2 = Node("n2", [n1])
+        tm = SCons.Taskmaster.Taskmaster([n2,n2])
+        t = tm.next_task()
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert tm.next_task() is None
+
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1], [n2])
+        tm = SCons.Taskmaster.Taskmaster([n3])
+        t = tm.next_task()
+        target = t.get_target()
+        assert target == n1, target
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        target = t.get_target()
+        assert target == n2, target
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        target = t.get_target()
+        assert target == n3, target
+        t.executed()
+        t.postprocess()
+        assert tm.next_task() is None
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1, n2])
+        n4 = Node("n4", [n3])
+        n5 = Node("n5", [n3])
+        global scan_called
+        scan_called = 0
+        tm = SCons.Taskmaster.Taskmaster([n4])
+        t = tm.next_task()
+        assert t.get_target() == n1
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n2
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n3
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n4
+        t.executed()
+        t.postprocess()
+        assert tm.next_task() is None
+        assert scan_called == 4, scan_called
+
+        tm = SCons.Taskmaster.Taskmaster([n5])
+        t = tm.next_task()
+        assert t.get_target() == n5, t.get_target()
+        t.executed()
+        assert tm.next_task() is None
+        assert scan_called == 5, scan_called
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3")
+        n4 = Node("n4", [n1,n2,n3])
+        n5 = Node("n5", [n4])
+        n3.side_effect = 1
+        n1.side_effects = n2.side_effects = n3.side_effects = [n4]
+        tm = SCons.Taskmaster.Taskmaster([n1,n2,n3,n4,n5])
+        t = tm.next_task()
+        assert t.get_target() == n1
+        assert n4.state == SCons.Node.executing, n4.state
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n2
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n3
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n4
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n5
+        assert not tm.next_task()
+        t.executed()
+        t.postprocess()
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3")
+        n4 = Node("n4", [n1,n2,n3])
+        def reverse(dependencies):
+            dependencies.reverse()
+            return dependencies
+        tm = SCons.Taskmaster.Taskmaster([n4], order=reverse)
+        t = tm.next_task()
+        assert t.get_target() == n3, t.get_target()
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n2, t.get_target()
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n1, t.get_target()
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n4, t.get_target()
+        t.executed()
+        t.postprocess()
+
+        n5 = Node("n5")
+        n6 = Node("n6")
+        n7 = Node("n7")
+        n6.alttargets = [n7]
+
+        tm = SCons.Taskmaster.Taskmaster([n5])
+        t = tm.next_task()
+        assert t.get_target() == n5
+        t.executed()
+        t.postprocess()
+
+        tm = SCons.Taskmaster.Taskmaster([n6])
+        t = tm.next_task()
+        assert t.get_target() == n7
+        t.executed()
+        t.postprocess()
+        t = tm.next_task()
+        assert t.get_target() == n6
+        t.executed()
+        t.postprocess()
+
+        n1 = Node("n1")
+        n2 = Node("n2", [n1])
+        n1.set_state(SCons.Node.failed)
+        tm = SCons.Taskmaster.Taskmaster([n2])
+        assert tm.next_task() is None
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n1.targets = [n1, n2]
+        n1._current_val = 1
+        tm = SCons.Taskmaster.Taskmaster([n1])
+        t = tm.next_task()
+        t.executed()
+        t.postprocess()
+
+        s = n1.get_state()
+        assert s == SCons.Node.executed, s
+        s = n2.get_state()
+        assert s == SCons.Node.executed, s
+
+
+    def test_make_ready_out_of_date(self):
+        """Test the Task.make_ready() method's list of out-of-date Nodes
+        """
+        ood = []
+        def TaskGen(tm, targets, top, node, ood=ood):
+            class MyTask(SCons.Taskmaster.Task):
+                def make_ready(self):
+                    SCons.Taskmaster.Task.make_ready(self)
+                    self.ood.extend(self.out_of_date)
+            t = MyTask(tm, targets, top, node)
+            t.ood = ood
+            return t
+
+        n1 = Node("n1")
+        c2 = Node("c2")
+        c2._current_val = 1
+        n3 = Node("n3")
+        c4 = Node("c4")
+        c4._current_val = 1
+        a5 = Node("a5")
+        a5._current_val = 1
+        a5.always_build = 1
+        tm = SCons.Taskmaster.Taskmaster(targets = [n1, c2, n3, c4, a5],
+                                         tasker = TaskGen)
+
+        del ood[:]
+        t = tm.next_task()
+        assert ood == [n1], ood
+
+        del ood[:]
+        t = tm.next_task()
+        assert ood == [], ood
+
+        del ood[:]
+        t = tm.next_task()
+        assert ood == [n3], ood
+
+        del ood[:]
+        t = tm.next_task()
+        assert ood == [], ood
+
+        del ood[:]
+        t = tm.next_task()
+        assert ood == [a5], ood
+
+    def test_make_ready_exception(self):
+        """Test handling exceptions from Task.make_ready()
+        """
+        class MyTask(SCons.Taskmaster.Task):
+            def make_ready(self):
+                raise MyException, "from make_ready()"
+
+        n1 = Node("n1")
+        tm = SCons.Taskmaster.Taskmaster(targets = [n1], tasker = MyTask)
+        t = tm.next_task()
+        exc_type, exc_value, exc_tb = t.exception
+        assert exc_type == MyException, repr(exc_type)
+        assert str(exc_value) == "from make_ready()", exc_value
+
+
+    def test_make_ready_all(self):
+        """Test the make_ready_all() method"""
+        class MyTask(SCons.Taskmaster.Task):
+            make_ready = SCons.Taskmaster.Task.make_ready_all
+
+        n1 = Node("n1")
+        c2 = Node("c2")
+        c2._current_val = 1
+        n3 = Node("n3")
+        c4 = Node("c4")
+        c4._current_val = 1
+
+        tm = SCons.Taskmaster.Taskmaster(targets = [n1, c2, n3, c4])
+
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is n1, target
+        assert target.state == SCons.Node.executing, target.state
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is c2, target
+        assert target.state == SCons.Node.up_to_date, target.state
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is n3, target
+        assert target.state == SCons.Node.executing, target.state
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is c4, target
+        assert target.state == SCons.Node.up_to_date, target.state
+        t = tm.next_task()
+        assert t is None
+
+        n1 = Node("n1")
+        c2 = Node("c2")
+        n3 = Node("n3")
+        c4 = Node("c4")
+
+        tm = SCons.Taskmaster.Taskmaster(targets = [n1, c2, n3, c4],
+                                         tasker = MyTask)
+
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is n1, target
+        assert target.state == SCons.Node.executing, target.state
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is c2, target
+        assert target.state == SCons.Node.executing, target.state
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is n3, target
+        assert target.state == SCons.Node.executing, target.state
+        t = tm.next_task()
+        target = t.get_target()
+        assert target is c4, target
+        assert target.state == SCons.Node.executing, target.state
+        t = tm.next_task()
+        assert t is None
+
+
+    def test_children_errors(self):
+        """Test errors when fetching the children of a node.
+        """
+        class StopNode(Node):
+            def children(self):
+                raise SCons.Errors.StopError, "stop!"
+        class ExitNode(Node):
+            def children(self):
+                sys.exit(77)
+
+        n1 = StopNode("n1")
+        tm = SCons.Taskmaster.Taskmaster([n1])
+        t = tm.next_task()
+        exc_type, exc_value, exc_tb = t.exception
+        assert exc_type == SCons.Errors.StopError, repr(exc_type)
+        assert str(exc_value) == "stop!", exc_value
+
+        n2 = ExitNode("n2")
+        tm = SCons.Taskmaster.Taskmaster([n2])
+        t = tm.next_task()
+        exc_type, exc_value = t.exception
+        assert exc_type == SCons.Errors.ExplicitExit, repr(exc_type)
+        assert exc_value.node == n2, exc_value.node
+        assert exc_value.status == 77, exc_value.status
+
+    def test_cycle_detection(self):
+        """Test detecting dependency cycles
+        """
+        n1 = Node("n1")
+        n2 = Node("n2", [n1])
+        n3 = Node("n3", [n2])
+        n1.kids = [n3]
+
+        tm = SCons.Taskmaster.Taskmaster([n3])
+        try:
+            t = tm.next_task()
+        except SCons.Errors.UserError, e:
+            assert str(e) == "Dependency cycle: n3 -> n1 -> n2 -> n3", str(e)
+        else:
+            assert 'Did not catch expected UserError'
+
+    def test_next_top_level_candidate(self):
+        """Test the next_top_level_candidate() method
+        """
+        n1 = Node("n1")
+        n2 = Node("n2", [n1])
+        n3 = Node("n3", [n2])
+
+        tm = SCons.Taskmaster.Taskmaster([n3])
+        t = tm.next_task()
+        assert t.targets == [n1], t.targets
+        t.fail_stop()
+        assert t.targets == [n3], map(str, t.targets)
+        assert t.top == 1, t.top
+
+    def test_stop(self):
+        """Test the stop() method
+
+        Both default and overridden in a subclass.
+        """
+        global built_text
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1, n2])
+
+        tm = SCons.Taskmaster.Taskmaster([n3])
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        assert built_text == "n1 built", built_text
+        t.executed()
+        t.postprocess()
+        assert built_text == "n1 built really", built_text
+
+        tm.stop()
+        assert tm.next_task() is None
+
+        class MyTM(SCons.Taskmaster.Taskmaster):
+            def stop(self):
+                global built_text
+                built_text = "MyTM.stop()"
+                SCons.Taskmaster.Taskmaster.stop(self)
+
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1, n2])
+
+        built_text = None
+        tm = MyTM([n3])
+        tm.next_task().execute()
+        assert built_text == "n1 built"
+
+        tm.stop()
+        assert built_text == "MyTM.stop()"
+        assert tm.next_task() is None
+
+    def test_executed(self):
+        """Test when a task has been executed
+        """
+        global built_text
+        global visited_nodes
+
+        n1 = Node("n1")
+        tm = SCons.Taskmaster.Taskmaster([n1])
+        t = tm.next_task()
+        built_text = "xxx"
+        visited_nodes = []
+        n1.set_state(SCons.Node.executing)
+
+        t.executed()
+
+        s = n1.get_state()
+        assert s == SCons.Node.executed, s
+        assert built_text == "xxx really", built_text
+        assert visited_nodes == ['n1'], visited_nodes
+
+        n2 = Node("n2")
+        tm = SCons.Taskmaster.Taskmaster([n2])
+        t = tm.next_task()
+        built_text = "should_not_change"
+        visited_nodes = []
+        n2.set_state(None)
+
+        t.executed()
+
+        s = n2.get_state()
+        assert s is None, s
+        assert built_text == "should_not_change", built_text
+        assert visited_nodes == ['n2'], visited_nodes
+
+        n3 = Node("n3")
+        n4 = Node("n4")
+        n3.targets = [n3, n4]
+        tm = SCons.Taskmaster.Taskmaster([n3])
+        t = tm.next_task()
+        visited_nodes = []
+        n3.set_state(SCons.Node.up_to_date)
+        n4.set_state(SCons.Node.executing)
+
+        t.executed()
+
+        s = n3.get_state()
+        assert s == SCons.Node.up_to_date, s
+        s = n4.get_state()
+        assert s == SCons.Node.executed, s
+        assert visited_nodes == ['n3', 'n4'], visited_nodes
+
+    def test_prepare(self):
+        """Test preparation of multiple Nodes for a task
+        """
+        n1 = Node("n1")
+        n2 = Node("n2")
+        tm = SCons.Taskmaster.Taskmaster([n1, n2])
+        t = tm.next_task()
+        # This next line is moderately bogus.  We're just reaching
+        # in and setting the targets for this task to an array.  The
+        # "right" way to do this would be to have the next_task() call
+        # set it up by having something that approximates a real Builder
+        # return this list--but that's more work than is probably
+        # warranted right now.
+        n1.get_executor().targets = [n1, n2]
+        t.prepare()
+        assert n1.prepared
+        assert n2.prepared
+
+        n3 = Node("n3")
+        n4 = Node("n4")
+        tm = SCons.Taskmaster.Taskmaster([n3, n4])
+        t = tm.next_task()
+        # More bogus reaching in and setting the targets.
+        n3.set_state(SCons.Node.up_to_date)
+        n3.get_executor().targets = [n3, n4]
+        t.prepare()
+        assert n3.prepared
+        assert n4.prepared
+
+        # If the Node has had an exception recorded while it was getting
+        # prepared, then prepare() should raise that exception.
+        class MyException(Exception):
+            pass
+
+        built_text = None
+        n5 = Node("n5")
+        tm = SCons.Taskmaster.Taskmaster([n5])
+        t = tm.next_task()
+        t.exception_set((MyException, "exception value"))
+        exc_caught = None
+        try:
+            t.prepare()
+        except MyException, e:
+            exc_caught = 1
+        except:
+            pass
+        assert exc_caught, "did not catch expected MyException"
+        assert str(e) == "exception value", e
+        assert built_text is None, built_text
+
+        # Regression test, make sure we prepare not only
+        # all targets, but their side effects as well.
+        n6 = Node("n6")
+        n7 = Node("n7")
+        n8 = Node("n8")
+        n9 = Node("n9")
+        n10 = Node("n10")
+
+        n6.side_effects = [ n8 ]
+        n7.side_effects = [ n9, n10 ]
+
+        tm = SCons.Taskmaster.Taskmaster([n6, n7])
+        t = tm.next_task()
+        # More bogus reaching in and setting the targets.
+        n6.get_executor().targets = [n6, n7]
+        t.prepare()
+        assert n6.prepared
+        assert n7.prepared
+        assert n8.prepared
+        assert n9.prepared
+        assert n10.prepared
+
+        # Make sure we call an Executor's prepare() method.
+        class ExceptionExecutor:
+            def prepare(self):
+                raise Exception, "Executor.prepare() exception"
+            def get_all_targets(self):
+                return self.nodes
+            def get_all_children(self):
+                result = []
+                for node in self.nodes:
+                    result.extend(node.children())
+                return result
+            def get_all_prerequisites(self):
+                return []
+            def get_action_side_effects(self):
+                return []
+
+        n11 = Node("n11")
+        n11.executor = ExceptionExecutor()
+        n11.executor.nodes = [n11]
+        tm = SCons.Taskmaster.Taskmaster([n11])
+        t = tm.next_task()
+        try:
+            t.prepare()
+        except Exception, e:
+            assert str(e) == "Executor.prepare() exception", e
+        else:
+            raise AssertionError, "did not catch expected exception"
+
+    def test_execute(self):
+        """Test executing a task
+        """
+        global built_text
+        global cache_text
+
+        n1 = Node("n1")
+        tm = SCons.Taskmaster.Taskmaster([n1])
+        t = tm.next_task()
+        t.execute()
+        assert built_text == "n1 built", built_text
+
+        def raise_UserError():
+            raise SCons.Errors.UserError
+        n2 = Node("n2")
+        n2.build = raise_UserError
+        tm = SCons.Taskmaster.Taskmaster([n2])
+        t = tm.next_task()
+        try:
+            t.execute()
+        except SCons.Errors.UserError:
+            pass
+        else:
+            raise TestFailed, "did not catch expected UserError"
+
+        def raise_BuildError():
+            raise SCons.Errors.BuildError
+        n3 = Node("n3")
+        n3.build = raise_BuildError
+        tm = SCons.Taskmaster.Taskmaster([n3])
+        t = tm.next_task()
+        try:
+            t.execute()
+        except SCons.Errors.BuildError:
+            pass
+        else:
+            raise TestFailed, "did not catch expected BuildError"
+
+        # On a generic (non-BuildError) exception from a Builder,
+        # the target should throw a BuildError exception with the
+        # args set to the exception value, instance, and traceback.
+        def raise_OtherError():
+            raise OtherError
+        n4 = Node("n4")
+        n4.build = raise_OtherError
+        tm = SCons.Taskmaster.Taskmaster([n4])
+        t = tm.next_task()
+        try:
+            t.execute()
+        except SCons.Errors.BuildError, e:
+            assert e.node == n4, e.node
+            assert e.errstr == "OtherError : ", e.errstr
+            assert len(e.exc_info) == 3, e.exc_info
+            exc_traceback = sys.exc_info()[2]
+            assert type(e.exc_info[2]) == type(exc_traceback), e.exc_info[2]
+        else:
+            raise TestFailed, "did not catch expected BuildError"
+
+        built_text = None
+        cache_text = []
+        n5 = Node("n5")
+        n6 = Node("n6")
+        n6.cached = 1
+        tm = SCons.Taskmaster.Taskmaster([n5])
+        t = tm.next_task()
+        # This next line is moderately bogus.  We're just reaching
+        # in and setting the targets for this task to an array.  The
+        # "right" way to do this would be to have the next_task() call
+        # set it up by having something that approximates a real Builder
+        # return this list--but that's more work than is probably
+        # warranted right now.
+        t.targets = [n5, n6]
+        t.execute()
+        assert built_text == "n5 built", built_text
+        assert cache_text == [], cache_text
+
+        built_text = None
+        cache_text = []
+        n7 = Node("n7")
+        n8 = Node("n8")
+        n7.cached = 1
+        n8.cached = 1
+        tm = SCons.Taskmaster.Taskmaster([n7])
+        t = tm.next_task()
+        # This next line is moderately bogus.  We're just reaching
+        # in and setting the targets for this task to an array.  The
+        # "right" way to do this would be to have the next_task() call
+        # set it up by having something that approximates a real Builder
+        # return this list--but that's more work than is probably
+        # warranted right now.
+        t.targets = [n7, n8]
+        t.execute()
+        assert built_text is None, built_text
+        assert cache_text == ["n7 retrieved", "n8 retrieved"], cache_text
+
+    def test_exception(self):
+        """Test generic Taskmaster exception handling
+
+        """
+        n1 = Node("n1")
+        tm = SCons.Taskmaster.Taskmaster([n1])
+        t  = tm.next_task()
+
+        t.exception_set((1, 2))
+        exc_type, exc_value = t.exception
+        assert exc_type == 1, exc_type
+        assert exc_value == 2, exc_value
+
+        t.exception_set(3)
+        assert t.exception == 3
+
+        try: 1/0
+        except: pass
+        t.exception_set(None)
+        exc_type, exc_value, exc_tb = t.exception
+        assert exc_type is ZeroDivisionError, exc_type
+        exception_values = [
+            "integer division or modulo",
+            "integer division or modulo by zero",
+        ]
+        assert str(exc_value) in exception_values, exc_value
+
+        class Exception1(Exception):
+            pass
+
+        t.exception_set((Exception1, None))
+        try:
+            t.exception_raise()
+        except:
+            exc_type, exc_value = sys.exc_info()[:2]
+            assert exc_type == Exception1, exc_type
+            assert str(exc_value) == '', exc_value
+        else:
+            assert 0, "did not catch expected exception"
+
+        class Exception2(Exception):
+            pass
+
+        t.exception_set((Exception2, "xyzzy"))
+        try:
+            t.exception_raise()
+        except:
+            exc_type, exc_value = sys.exc_info()[:2]
+            assert exc_type == Exception2, exc_type
+            assert str(exc_value) == "xyzzy", exc_value
+        else:
+            assert 0, "did not catch expected exception"
+
+        class Exception3(Exception):
+            pass
+
+        try:
+            1/0
+        except:
+            tb = sys.exc_info()[2]
+        t.exception_set((Exception3, "arg", tb))
+        try:
+            t.exception_raise()
+        except:
+            exc_type, exc_value, exc_tb = sys.exc_info()
+            assert exc_type == Exception3, exc_type
+            assert str(exc_value) == "arg", exc_value
+            import traceback
+            x = traceback.extract_tb(tb)[-1]
+            y = traceback.extract_tb(exc_tb)[-1]
+            assert x == y, "x = %s, y = %s" % (x, y)
+        else:
+            assert 0, "did not catch expected exception"
+
+    def test_postprocess(self):
+        """Test postprocessing targets to give them a chance to clean up
+        """
+        n1 = Node("n1")
+        tm = SCons.Taskmaster.Taskmaster([n1])
+
+        t = tm.next_task()
+        assert not n1.postprocessed
+        t.postprocess()
+        assert n1.postprocessed
+
+        n2 = Node("n2")
+        n3 = Node("n3")
+        tm = SCons.Taskmaster.Taskmaster([n2, n3])
+
+        assert not n2.postprocessed
+        assert not n3.postprocessed
+        t = tm.next_task()
+        t.postprocess()
+        assert n2.postprocessed
+        assert not n3.postprocessed
+        t = tm.next_task()
+        t.postprocess()
+        assert n2.postprocessed
+        assert n3.postprocessed
+
+    def test_trace(self):
+        """Test Taskmaster tracing
+        """
+        import StringIO
+
+        trace = StringIO.StringIO()
+        n1 = Node("n1")
+        n2 = Node("n2")
+        n3 = Node("n3", [n1, n2])
+        tm = SCons.Taskmaster.Taskmaster([n1, n1, n3], trace=trace)
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        t.postprocess()
+        n1.set_state(SCons.Node.executed)
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        t.postprocess()
+        n2.set_state(SCons.Node.executed)
+        t = tm.next_task()
+        t.prepare()
+        t.execute()
+        t.postprocess()
+        t = tm.next_task()
+        assert t is None
+
+        value = trace.getvalue()
+        expect = """\
+
+Taskmaster: Looking for a node to evaluate
+Taskmaster:     Considering node <no_state   0   'n1'> and its children:
+Taskmaster: Evaluating <pending    0   'n1'>
+
+Task.make_ready_current(): node <pending    0   'n1'>
+Task.prepare():      node <executing  0   'n1'>
+Task.execute():      node <executing  0   'n1'>
+Task.postprocess():  node <executing  0   'n1'>
+
+Taskmaster: Looking for a node to evaluate
+Taskmaster:     Considering node <executed   0   'n1'> and its children:
+Taskmaster:        already handled (executed)
+Taskmaster:     Considering node <no_state   0   'n3'> and its children:
+Taskmaster:        <executed   0   'n1'>
+Taskmaster:        <no_state   0   'n2'>
+Taskmaster:      adjusted ref count: <pending    1   'n3'>, child 'n2'
+Taskmaster:     Considering node <no_state   0   'n2'> and its children:
+Taskmaster: Evaluating <pending    0   'n2'>
+
+Task.make_ready_current(): node <pending    0   'n2'>
+Task.prepare():      node <executing  0   'n2'>
+Task.execute():      node <executing  0   'n2'>
+Task.postprocess():  node <executing  0   'n2'>
+Task.postprocess():  removing <executing  0   'n2'>
+Task.postprocess():  adjusted parent ref count <pending    0   'n3'>
+
+Taskmaster: Looking for a node to evaluate
+Taskmaster:     Considering node <pending    0   'n3'> and its children:
+Taskmaster:        <executed   0   'n1'>
+Taskmaster:        <executed   0   'n2'>
+Taskmaster: Evaluating <pending    0   'n3'>
+
+Task.make_ready_current(): node <pending    0   'n3'>
+Task.prepare():      node <executing  0   'n3'>
+Task.execute():      node <executing  0   'n3'>
+Task.postprocess():  node <executing  0   'n3'>
+
+Taskmaster: Looking for a node to evaluate
+Taskmaster: No candidate anymore.
+
+"""
+        assert value == expect, value
+
+
+
+if __name__ == "__main__":
+    suite = unittest.makeSuite(TaskmasterTestCase, 'test_')
+    if not unittest.TextTestRunner().run(suite).wasSuccessful():
+        sys.exit(1)
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: