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

3 files changed, 88 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))
diff --git a/test/Depends/spurious-rebuilds.py b/test/Depends/spurious-rebuilds.py
new file mode 100644
index 00000000..6afc829d
--- /dev/null
+++ b/test/Depends/spurious-rebuilds.py
@@ -0,0 +1,72 @@
+#!/usr/bin/env python
+#
+# __COPYRIGHT__
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
+
+"""
+After adding some code for reducing the overall memory consumption in
+revision b4bc497, a number of spurious rebuilds was observed by different
+people. The problem was, that the value of the Node.changed() method got cached
+too early for File nodes.
+
+This test verifies that the changed() function works properly, especially
+in connection with auto-generated sources, combined with an explicit Depends().  
+"""
+
+import TestSCons
+
+test = TestSCons.TestSCons()
+
+test.write('SConstruct', """\
+# This tests the too-many-rebuilds problem with SCons 2.3.1 (test)
+# Run like this: scons all-defuns.obj
+
+# Test setup (only runs once)
+import os.path
+if not os.path.exists('mkl'):
+  os.mkdir('mkl')
+if not os.path.exists('test.c'):
+  open('test.c', 'w').write('int i;')
+
+env=Environment()
+env.SharedObject('all-defuns.obj', 'all-defuns.c')
+results = env.Command('all-defuns.c', 'test.c', Copy('$TARGET', '$SOURCE'))
+env.Depends(results, '#mkl')
+""")
+
+test.run(arguments = 'all-defuns.obj')
+
+test.must_exist('all-defuns.c')
+test.must_exist('test.c')
+test.must_exist('all-defuns.obj')
+
+test.up_to_date(arguments = 'all-defuns.obj')
+
+test.pass_test()
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: