Get rid of the self-referential permanent __env__ variable in favor of adding it to the new lvars() dictionary on each substitution.

2 files changed, 8 insertions, 28 deletions

diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index 8c2e767..96403f1 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -250,18 +250,9 @@ class SubstitutionEnvironment:
         self.ans = SCons.Node.Alias.default_ans
         self.lookup_list = SCons.Node.arg2nodes_lookups
         self._dict = kw.copy()
-        self._dict['__env__'] = self
 
     def __cmp__(self, other):
-        # Since an Environment now has an '__env__' construction variable
-        # that refers to itself, delete that variable to avoid infinite
-        # loops when comparing the underlying dictionaries in some Python
-        # versions (*cough* 1.5.2 *cough*)...
-        sdict = self._dict.copy()
-        del sdict['__env__']
-        odict = other._dict.copy()
-        del odict['__env__']
-        return cmp(sdict, odict)
+        return cmp(self._dict, other._dict)
 
     def __delitem__(self, key):
         "__cache_reset__"
@@ -299,10 +290,7 @@ class SubstitutionEnvironment:
         return self._dict.has_key(key)
 
     def items(self):
-        "Emulates the items() method of dictionaries."""
-        result = self._dict.items()
-        result = filter(lambda t: t[0] != '__env__', result)
-        return result
+        return self._dict.items()
 
     def arg2nodes(self, args, node_factory=_null, lookup_list=_null):
         if node_factory is _null:
@@ -364,6 +352,7 @@ class SubstitutionEnvironment:
         """
         gvars = self.gvars()
         lvars = self.lvars()
+        lvars['__env__'] = self
         return SCons.Util.scons_subst(string, self, raw, target, source, gvars, lvars, conv)
 
     def subst_kw(self, kw, raw=0, target=None, source=None):
@@ -380,6 +369,7 @@ class SubstitutionEnvironment:
         the documentation for that function."""
         gvars = self.gvars()
         lvars = self.lvars()
+        lvars['__env__'] = self
         return SCons.Util.scons_subst_list(string, self, raw, target, source, gvars, lvars, conv)
 
     def subst_path(self, path):
@@ -494,7 +484,6 @@ class Base(SubstitutionEnvironment):
         self.lookup_list = SCons.Node.arg2nodes_lookups
         self._dict = our_deepcopy(SCons.Defaults.ConstructionEnvironment)
 
-        self._dict['__env__'] = self
         self._dict['BUILDERS'] = BuilderDict(self._dict['BUILDERS'], self)
 
         if platform is None:
@@ -727,7 +716,6 @@ class Base(SubstitutionEnvironment):
         """
         clone = copy.copy(self)
         clone._dict = our_deepcopy(self._dict)
-        clone['__env__'] = clone
         try:
             cbd = clone._dict['BUILDERS']
             clone._dict['BUILDERS'] = BuilderDict(cbd, clone)
@@ -1418,7 +1406,6 @@ class OverrideEnvironment(SubstitutionEnvironment):
         if __debug__: logInstanceCreation(self, 'OverrideEnvironment')
         self.__dict__['__subject'] = subject
         self.__dict__['overrides'] = overrides
-        self.__dict__['overrides']['__env__'] = self
 
     # Methods that make this class act like a proxy.
     def __getattr__(self, name):
diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index a0b1615..87e2e44 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -155,7 +155,7 @@ class SubstitutionTestCase(unittest.TestCase):
         """Test initializing a SubstitutionEnvironment
         """
         env = SubstitutionEnvironment()
-        assert env['__env__'] is env, env['__env__']
+        assert not env.has_key('__env__')
 
     def test___cmp__(self):
         """Test comparing SubstitutionEnvironments
@@ -338,7 +338,7 @@ class SubstitutionTestCase(unittest.TestCase):
         """Test the base class gvars() method"""
         env = SubstitutionEnvironment()
         gvars = env.gvars()
-        assert gvars == {'__env__' : env}, gvars
+        assert gvars == {}, gvars
 
     def test_lvars(self):
         """Test the base class lvars() method"""
@@ -549,9 +549,6 @@ class SubstitutionTestCase(unittest.TestCase):
         assert env2['ONE'] == "won", env2['ONE']
         assert env['ONE'] == 1, env['ONE']
 
-        assert env['__env__'] is env, env['__env__']
-        assert env2['__env__'] is env2, env2['__env__']
-
 
 
 class BaseTestCase(unittest.TestCase):
@@ -566,8 +563,8 @@ class BaseTestCase(unittest.TestCase):
         env2 = Environment(XXX = 'x', YYY = 'y')
         assert env1 == env2, diff_env(env1, env2)
 
-        assert env1['__env__'] is env1, env1['__env__']
-        assert env2['__env__'] is env2, env2['__env__']
+        assert not env1.has_key('__env__')
+        assert not env2.has_key('__env__')
 
     def test_get(self):
         """Test the get() method."""
@@ -1260,10 +1257,6 @@ def exists(env):
         assert env3.Dictionary('ZZZ') == 'z3'
         assert env1 == env1copy
 
-        assert env1['__env__'] is env1, env1['__env__']
-        assert env2['__env__'] is env2, env2['__env__']
-        assert env3['__env__'] is env3, env3['__env__']
-
         # Ensure that lists and dictionaries are
         # deep copied, but not instances.
         class TestA: