- fix for spurious rebuilds, allow caching of the changed() method's value only when called from File.release_target_info()

2 files changed, 16 insertions, 4 deletions

diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index aaa5b473..dc8affe5 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -2779,7 +2779,7 @@ class File(Base):
         if not hasattr(self.attributes, 'keep_targetinfo'):
             # Cache some required values, before releasing
             # stuff like env, executor and builder...
-            self.changed()
+            self.changed(allowcache=True)
             self.get_contents_sig()
             self.get_build_env()
             # Now purge unneeded stuff to free memory...
@@ -3034,7 +3034,7 @@ class File(Base):
              
             self.scanner_paths = None
 
-    def changed(self, node=None):
+    def changed(self, node=None, allowcache=False):
         """
         Returns if the node is up-to-date with respect to the BuildInfo
         stored last time it was built. 
@@ -3042,6 +3042,8 @@ class File(Base):
         For File nodes this is basically a wrapper around Node.changed(),
         but we allow the return value to get cached after the reference
         to the Executor got released in release_target_info().
+        
+        @see: Node.changed()
         """
         if node is None:
             try:
@@ -3050,7 +3052,8 @@ class File(Base):
                 pass
         
         has_changed = SCons.Node.Node.changed(self, node)
-        self._memo['changed'] = has_changed
+        if allowcache:
+            self._memo['changed'] = has_changed
         return has_changed
 
     def changed_content(self, target, prev_ni):
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index d6dbf2e6..1f629712 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -1049,7 +1049,7 @@ class Node(object):
     def Decider(self, function):
         SCons.Util.AddMethod(self, function, 'changed_since_last_build')
 
-    def changed(self, node=None):
+    def changed(self, node=None, allowcache=False):
         """
         Returns if the node is up-to-date with respect to the BuildInfo
         stored last time it was built.  The default behavior is to compare
@@ -1062,6 +1062,15 @@ class Node(object):
         any difference, but we now rely on checking every dependency
         to make sure that any necessary Node information (for example,
         the content signature of an #included .h file) is updated.
+        
+        The allowcache option was added for supporting the early
+        release of the executor/builder structures, right after
+        a File target was built. When set to true, the return
+        value of this changed method gets cached for File nodes.
+        Like this, the executor isn't needed any longer for subsequent
+        calls to changed().
+        
+        @see: FS.File.changed(), FS.File.release_target_info()
         """
         t = 0
         if t: Trace('changed(%s [%s], %s)' % (self, classname(self), node))