Effectively duplicates targets that contain rules/actions, therefore enabling...

pylib/gyp/common.py

 #!/usr/bin/python
 
 # Copyright (c) 2009 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import errno
 import filecmp
 import os.path
 import re
@@ skipping 201 matching lines @@
 
   Returns EncodePOSIXShellArgument for each item in list, and joins them
   together using the space character as an argument separator.
   """
 
   encoded_arguments = []
   for argument in list:
     encoded_arguments.append(EncodePOSIXShellArgument(argument))
   return ' '.join(encoded_arguments)
 
-
-def DeepDependencyTargets(target_dicts, roots):
+def DeepDependencyTargets(target_dicts, roots, dependencies=None):

[Mark Mentovai, 2010/07/07 17:45:28]

Could you explain what’s going on in this function? It’s heinous enough that an
inline comment (or several) would help.

   """Returns the recursive list of target dependencies.
   """
-  dependencies = set()
+  dependencies = dependencies or set()
+  unseen_deps = []
   for r in roots:
     spec = target_dicts[r]
     r_deps = list(set((spec.get('dependencies', []) +
                        spec.get('dependencies_original', []))))
     for d in r_deps:
-      if d not in roots:
+      if d not in dependencies and d not in roots:
         dependencies.add(d)
-    for d in DeepDependencyTargets(target_dicts, r_deps):
-      if d not in roots:
-        dependencies.add(d)
+        unseen_deps.append(d)
+  if unseen_deps:
+    DeepDependencyTargets(target_dicts, unseen_deps, dependencies)
   return list(dependencies)
 
 
 def BuildFileTargets(target_list, build_file):
   """From a target_list, returns the subset from the specified build_file.
   """
   return [p for p in target_list if BuildFile(p) == build_file]
 
 
 def AllTargets(target_list, target_dicts, build_file):
@@ skipping 87 matching lines @@
     if idfun is None:
         def idfun(x): return x
     seen = {}
     result = []
     for item in seq:
         marker = idfun(item)
         if marker in seen: continue
         seen[marker] = 1
         result.append(item)
     return result