Document function Actions and fix their return values (None == success, don't ignore failures).

2 files changed, 40 insertions, 4 deletions

diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index f55659e..37b9f37 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -47,10 +47,19 @@ class Builder:
     def get_contents(self, env, dir):
         return 7
 
+class NoneBuilder(Builder):
+    def execute(self, **kw):
+        apply(Builder.execute, (self,), kw)
+        return None
+
 class FailBuilder:
     def execute(self, **kw):
         return 1
 
+class ExceptBuilder:
+    def execute(self, **kw):
+        raise SCons.Errors.BuildError
+
 class Environment:
     def Dictionary(self, *args):
 	pass
@@ -72,9 +81,21 @@ class NodeTestCase(unittest.TestCase):
 	else:
 	    raise TestFailed, "did not catch expected BuildError"
 
+        node = SCons.Node.Node()
+        node.builder_set(ExceptBuilder())
+        node.env_set(Environment())
+        try:
+            node.build()
+        except SCons.Errors.BuildError:
+            pass
+        else:
+            raise TestFailed, "did not catch expected BuildError"
+
     def test_build(self):
 	"""Test building a node
 	"""
+        global built_it
+
         class MyNode(SCons.Node.Node):
             def __str__(self):
                 return self.path
@@ -94,6 +115,18 @@ class NodeTestCase(unittest.TestCase):
         assert str(built_target) == "xxx", str(built_target)
         assert built_source == ["yyy", "zzz"], built_source
 
+        built_it = None
+        node = MyNode()
+        node.builder_set(NoneBuilder())
+        node.env_set(Environment())
+        node.path = "qqq"
+        node.sources = ["rrr", "sss"]
+        node.build()
+        assert built_it
+        assert type(built_target) == type(MyNode()), type(built_target)
+        assert str(built_target) == "qqq", str(built_target)
+        assert built_source == ["rrr", "sss"], built_source
+
     def test_builder_set(self):
 	"""Test setting a Node's Builder
 	"""
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index b81f911..102b532 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -72,10 +72,13 @@ class Node:
         """Actually build the node.   Return the status from the build."""
 	if not self.builder:
 	    return None
-        stat = self.builder.execute(env = self.env.Dictionary(),
-                                    target = self, source = self.sources)
-	if stat != 0:
-	    raise BuildError(node = self, stat = stat)
+        try:
+            stat = self.builder.execute(env = self.env.Dictionary(),
+                                        target = self, source = self.sources)
+        except:
+            raise BuildError(node = self, errstr = "Exception")
+        if stat:
+            raise BuildError(node = self, errstr = "Error %d" % stat)
 
         # If we succesfully build a node, then we need to rescan for
         # implicit dependencies, since it might have changed on us.