Allow builders to inherit from OverrideEnvironments

3 files changed, 29 insertions, 1 deletions

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index a491ba53b..965bc28be 100755
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -79,6 +79,10 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
     - Fix more re patterns that contain \ but not specified as raw strings
       (affects scanners for D, LaTeX, swig)
 
+  From Mathew Robinson:
+    - Update cache debug output to include cache hit rate.
+    - No longer unintentionally hide exceptions in Action.py
+    - Allow builders and pseudo-builders to inherit from OverrideEnvironments
 
 RELEASE 3.0.5 - Mon, 26 Mar 2019 15:04:42 -0700
 
diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index 7f9a76c5e..395a6a79f 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -2305,7 +2305,20 @@ class OverrideEnvironment(Base):
 
     # Methods that make this class act like a proxy.
     def __getattr__(self, name):
-        return getattr(self.__dict__['__subject'], name)
+        attr = getattr(self.__dict__['__subject'], name)
+        # Here we check if attr is one of the Wrapper classes. For
+        # example when a pseudo-builder is being called from an
+        # OverrideEnvironment.
+        #
+        # These wrappers when they're constructed capture the
+        # Environment they are being constructed with and so will not
+        # have access to overrided values. So we rebuild them with the
+        # OverrideEnvironment so they have access to overrided values.
+        if isinstance(attr, (MethodWrapper, BuilderWrapper)):
+            return attr.clone(self)
+        else:
+            return attr
+        
     def __setattr__(self, name, value):
         setattr(self.__dict__['__subject'], name, value)
 
diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index 1a75a90fa..834cfd17e 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -3587,6 +3587,10 @@ class OverrideEnvironmentTestCase(unittest.TestCase,TestEnvironmentFixture):
     def setUp(self):
         env = Environment()
         env._dict = {'XXX' : 'x', 'YYY' : 'y'}
+        def verify_value(env, key, value, *args, **kwargs):
+            """Verifies that key is value on the env this is called with."""
+            assert env[key] == value
+        env.AddMethod(verify_value)
         env2 = OverrideEnvironment(env, {'XXX' : 'x2'})
         env3 = OverrideEnvironment(env2, {'XXX' : 'x3', 'YYY' : 'y3', 'ZZZ' : 'z3'})
         self.envs = [ env, env2, env3 ]
@@ -3777,6 +3781,13 @@ class OverrideEnvironmentTestCase(unittest.TestCase,TestEnvironmentFixture):
     #    """Test the OverrideEnvironment WhereIs() method"""
     #    pass
 
+    def test_PseudoBuilderInherits(self):
+        """Test that pseudo-builders inherit the overrided values."""
+        env, env2, env3 = self.envs
+        env.verify_value('XXX', 'x')
+        env2.verify_value('XXX', 'x2')
+        env3.verify_value('XXX', 'x3')
+
     def test_Dir(self):
         """Test the OverrideEnvironment Dir() method"""
         env, env2, env3 = self.envs