Rebuild in response to a changed build command.

2 files changed, 28 insertions, 0 deletions

diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index 035bc90..24ad955 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -39,6 +39,8 @@ class Builder:
 	global built_it
 	built_it = 1
         return 0
+    def get_contents(self, env):
+        return 7
 
 class FailBuilder:
     def execute(self, **kw):
@@ -89,6 +91,15 @@ class NodeTestCase(unittest.TestCase):
 	node.builder_set(b)
 	assert node.builder == b
 
+    def test_builder_sig_adapter(self):
+        """Test the node's adapter for builder signatures
+        """
+        node = SCons.Node.Node()
+        node.builder_set(Builder())
+        node.env_set(Environment())
+        c = node.builder_sig_adapter().get_contents()
+        assert c == 7, c
+
     def test_current(self):
         """Test the default current() method
         """
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index 0e1a8d9..513b260 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -79,6 +79,23 @@ class Node:
     def builder_set(self, builder):
 	self.builder = builder
 
+    def builder_sig_adapter(self):
+        """Create an adapter for calculating a builder's signature.
+
+        The underlying signature class will call get_contents()
+        to fetch the signature of a builder, but the actual
+        content of that signature depends on the node and the
+        environment (for construction variable substitution),
+        so this adapter provides the right glue between the two.
+        """
+        class Adapter:
+            def __init__(self, node):
+                self.node = node
+            def get_contents(self):
+                env = self.node.env.Dictionary()
+                return self.node.builder.get_contents(env = env)
+        return Adapter(self)
+
     def env_set(self, env):
 	self.env = env