Fix the dependency checker tool. Rules for a directory did modify their direc...

tools/checkdeps/checkdeps.py

Index: tools/checkdeps/checkdeps.py
===================================================================
--- tools/checkdeps/checkdeps.py	(revision 9136)
+++ tools/checkdeps/checkdeps.py	(working copy)
@@ -56,6 +56,7 @@
 import optparse
 import re
 import sys
+import copy
 
 # Variable name used in the DEPS file to specify module-level deps.
 DEPS_VAR_NAME = "deps"
@@ -180,7 +181,7 @@
   Returns: A new set of rules combining the existing_rules with the other
            arguments.
   """
-  rules = existing_rules
+  rules = copy.copy(existing_rules)
 
   # First apply the implicit "allow" rule for the current directory.
   if cur_dir.lower().startswith(BASE_DIRECTORY):
@@ -255,13 +256,14 @@
   local_scope = {}
   global_scope = {"From": FromImpl, "Var": _VarImpl(local_scope).Lookup}
   deps_file = os.path.join(dir_name, "DEPS")
-  if not os.path.exists(deps_file):
-    if VERBOSE:
-      print "  No deps file found in", dir_name
-    return (existing_rules, [])  # Nothing to change from the input rules.
 
-  execfile(deps_file, global_scope, local_scope)
+  if os.path.exists(deps_file):
+    execfile(deps_file, global_scope, local_scope)
+  elif VERBOSE:
+    print "  No deps file found in", dir_name
 
+  # Even if a DEPS file does not exist we still invoke ApplyRules
+  # to apply the implicit "allow" rule for the current directory
   deps = local_scope.get(DEPS_VAR_NAME, {})
   include_rules = local_scope.get(INCLUDE_RULES_VAR_NAME, [])
   skip_subdirs = local_scope.get(SKIP_SUBDIRS_VAR_NAME, [])
@@ -348,8 +350,8 @@
   return ret_val
 
 
-def CheckDirectory(rules, dir_name):
-  (rules, skip_subdirs) = ApplyDirectoryRules(rules, dir_name)
+def CheckDirectory(parent_rules, dir_name):
+  (rules, skip_subdirs) = ApplyDirectoryRules(parent_rules, dir_name)
   if rules == None:
     return True