gclient: in managed mode, warn if .gclient has a mismatched URL

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 86b742f594ed7252674207cd286ecd5f06fca115..913112e7918270e62be04437075361ad21404ece 100755
--- a/gclient.py
+++ b/gclient.py
@@ -78,6 +78,7 @@
 
 __version__ = '0.7'
 
+import atexit

[borenet, 2014/03/14 13:30:57]

Is atexit acceptable for this? It would be nice to have a way to gather
warnings/errors as we run and dump them all out at the end. That'd be especially
good for https://codereview.chromium.org/189913020/, to warn more loudly that
we've moved directories around.

[iannucci, 2014/03/17 17:38:40]

Hm. I would probably wrap atexit instead of directly registering callbacks, if
only because atexit works in LIFO order, which could be weird. Having a
print_on_exit(...) function could register a single atexit and then keep a queue
internally for messages to print.

[borenet, 2014/03/17 17:41:33]

Alternatively, I can just call the _CheckConfig method right before finishing,
rather than at the beginning.

 import copy
 import json
 import logging
@@ -1044,6 +1045,42 @@ solutions = [
     self._root_dir = root_dir
     self.config_content = None
 
+  def _CheckConfig(self):
+    """Verify that the config matches any existing checkout."""
+    for dep in self.dependencies:
+      if dep.managed:
+        scm = gclient_scm.CreateSCM(dep.url, self.root_dir, dep.name)
+        actual_url = scm.GetActualRemoteURL()
+        if actual_url and not scm.DoesRemoteURLMatch():
+          def print_warning():
+            print >> sys.stderr, ('''
+################################################################################
+################################### WARNING! ###################################
+################################################################################
+
+Your .gclient file seems to be broken. The requested URL is different from what
+is actually checked out in %(checkout_path)s. In the future this will be an
+error.
+
+Expected: %(expected_url)s (%(expected_scm)s)
+Actual:   %(actual_url)s (%(actual_scm)s)
+
+You should ensure that the URL listed in .gclient is correct and either change
+it or fix the checkout. If you're managing your own git checkout in
+%(checkout_path)s but the URL in .gclient is for an svn repository, you probably
+want to set 'managed': False in .gclient.
+
+################################################################################
+################################################################################
+################################################################################
+'''  % {'checkout_path': os.path.join(self.root_dir, dep.name),
+        'expected_url': dep.url,
+        'expected_scm': gclient_scm.GetScmName(dep.url),
+        'actual_url': actual_url,
+        'actual_scm': gclient_scm.GetScmName(actual_url)})
+
+          atexit.register(print_warning)
+
   def SetConfig(self, content):
     assert not self.dependencies
     config_dict = {}
@@ -1082,6 +1119,7 @@ solutions = [
         raise gclient_utils.Error('Invalid .gclient file. Solution is '
                                   'incomplete: %s' % s)
     self.add_dependencies_and_close(deps_to_add, config_dict.get('hooks', []))
+    self._CheckConfig()
     logging.info('SetConfig() done')
 
   def SaveConfig(self):
@@ -1694,6 +1732,7 @@ def CMDsync(parser, args):
     # Print out the .gclient file.  This is longer than if we just printed the
     # client dict, but more legible, and it might contain helpful comments.
     print(client.config_content)
+
   ret = client.RunOnDeps('update', args)
   if options.output_json:
     slns = {}