Add Dependency.requirements which will solve the issues found in pagespeed and parallel checkout.

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 70fad2d423b6fbddcafbd49a3d0ff5eb225dcfc9..dfd17c3b075867c540a9eeffbd58b812a655ffd9 100644
--- a/gclient.py
+++ b/gclient.py
@@ -54,6 +54,7 @@ __version__ = "0.5"
 import logging
 import optparse
 import os
+import posixpath
 import pprint
 import re
 import subprocess
@@ -165,6 +166,12 @@ class Dependency(GClientKeywords):
     self.processed = False
     # This dependency had its hook run
     self.hooks_ran = False
+    # Required dependencies to run before running this one:
+    self.requirements = []
+    if self.parent and self.parent.name:
+      self.requirements.append(self.parent.name)
+    if isinstance(self.url, self.FromImpl):
+      self.requirements.append(self.url.module_name)
 
     # Sanity checks
     if not self.name and self.parent:
@@ -362,6 +369,16 @@ class Dependency(GClientKeywords):
       if pm:
         pm._total = len(self.tree(False)) + 1
         pm.update(0)
+      # Adjust the implicit dependency requirement; e.g. if a DEPS file contains
+      # both src/foo and src/foo/bar, src/foo/bar is implicitly dependent of
+      # src/foo. Yes, it's O(n^2)...

[bradn, 2010/08/10 20:21:02]

Wait so, do I understand correctly that a sort won't work here because its
ordering is too strict (there recursive deps targets that have to come first
because you don't know about the repos they pull in?) Wanna make sure I
understand.

[M-A Ruel, 2010/08/10 20:28:45]

Yes. In pagespeed, they have something like that:

deps = {
 'src/third_party/chromium_deps: File('...chrome/trunk/src/DEPS'),
 'src/googleurl': From('src/chromium_deps')
}

That just doesn't work when the list is sorted. But just not sorting doesn't
work either, webkit.org's DEPS has other similar issues, hence the exact list of
requirements.

More details at:
http://code.google.com/p/page-speed/source/browse/lib/trunk/src/DEPS

+      for s in self.dependencies:
+        for s2 in self.dependencies:
+          if s is s2:
+            continue
+          if s.name.startswith(posixpath.join(s2.name, '')):
+            s.requirements.append(s2.name)
+
       # Parse the dependencies of this dependency.
       for s in self.dependencies:
         # TODO(maruel): All these can run concurrently! No need for threads,
@@ -476,7 +493,7 @@ class Dependency(GClientKeywords):
     out = []
     for i in ('name', 'url', 'parsed_url', 'safesync_url', 'custom_deps',
               'custom_vars', 'deps_hooks', '_file_list', 'processed',
-              'hooks_ran', 'deps_parsed'):
+              'hooks_ran', 'deps_parsed', 'requirements'):
       # 'deps_file'
       if self.__dict__[i]:
         out.append('%s: %s' % (i, self.__dict__[i]))