Drop overridden changed_since_last_build method in Value class

Value defined this method, but the __init__ methos also
does "self.changed_since_last_build = 6" to set an index into
the decider map, meaning no instance of Value will ever see
that function.  The map index will cause picking the "real" function,
changed_since_last_build_python(), which has identical impl to the now
removed method.

Signed-off-by: Mats Wichmann <mats@linux.com>

2 files changed, 1 insertions, 7 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index e7d555dd5..2f64355f0 100755
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -89,6 +89,7 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
     - Maintenance: remove obsolete __getslice__ definitions (Py3 never calls);
       add Node.fs.scandir to call new (Py3.5) os.scandir; Node.fs.makedirs
       now passes the exist_ok flag; Cachedir creation now uses this flag.
+    - Drop overridden changed_since_last_build method in Value class.
 
   From Dillan Mills:
     - Add support for the (TARGET,SOURCE,TARGETS,SOURCES,CHANGED_TARGETS,CHANGED_SOURCES}.relpath property.
diff --git a/SCons/Node/Python.py b/SCons/Node/Python.py
index 738682ccb..c6850abd8 100644
--- a/SCons/Node/Python.py
+++ b/SCons/Node/Python.py
@@ -146,13 +146,6 @@ class Value(SCons.Node.Node):
         """Get contents for signature calculations."""
         return self.get_text_contents().encode()
 
-    def changed_since_last_build(self, target, prev_ni):
-        cur_csig = self.get_csig()
-        try:
-            return cur_csig != prev_ni.csig
-        except AttributeError:
-            return True
-
     def get_csig(self, calc=None):
         """Because we're a Python value node and don't have a real
         timestamp, we get to ignore the calculator and just use the