Script to automate keeping ddc dep in sync.

BUG=
R=jmesserly@google.com, vsm@google.com

Review URL: https://codereview.chromium.org/2200973002 .

tools/update_ddc_dep.py

@@ -0,0 +1,135 @@
+#!/usr/bin/python
+
+# Update ddc dep automatically.
+
+import optparse
+import os
+import re
+from subprocess import Popen, PIPE
+import sys
+
+# Instructions:
+#
+# To run locally:
+#  (a) Create and change to a directory to run the updater in:
+#  mkdir /usr/local/google/home/$USER/ddc_deps_updater
+#
+#  (b) Test by running (Ctrl-C to quit):
+#      > ./update_ddc_deps.py
+#
+#  (c) Run periodical update:
+#      > while true; do ./update_ddc_deps.py --force ; sleep 300 ; done
+
+########################################################################
+# Actions
+########################################################################
+
+def write_file(filename, content):
+  f = open(filename, "w")
+  f.write(content)
+  f.close()
+
+def run_cmd(cmd):
+  print "\n[%s]\n$ %s" % (os.getcwd(), " ".join(cmd))
+  pipe = Popen(cmd, stdout=PIPE, stderr=PIPE)
+  output = pipe.communicate()
+  if pipe.returncode == 0:
+    return output[0]
+  else:
+    print output[1]
+    print "FAILED. RET_CODE=%d" % pipe.returncode
+    sys.exit(pipe.returncode)
+
+def main():
+  option_parser = optparse.OptionParser()
+  option_parser.add_option(
+      '',
+      '--force',
+      help="Push DEPS update to server without prompting",
+      action="store_true",
+      dest="force")
+  options, args = option_parser.parse_args()
+
+  target = 'ddc'
+  repo = 'dev_compiler'
+  repo_name = 'git@github.com:dart-lang/sdk.git'
+  ddc_repo_name = 'git@github.com:dart-lang/%s.git' % (repo)
+  repo_branch = 'origin/master'
+  repo_branch_parts = repo_branch.split('/')
+
+  root_dir = "/usr/local/google/home/%s/ddc_deps_updater" % (os.environ["USER"])
+  src_dir = "%s/sdk" % (root_dir)
+  ddc_dir = "%s/%s" % (root_dir, repo)
+  deps_file = src_dir + '/DEPS'
+
+  os.putenv("GIT_PAGER", "")
+
+  if not os.path.exists(src_dir):
+    print run_cmd(['git', 'clone', repo_name])
+
+  if not os.path.exists(ddc_dir):
+    print run_cmd(['git', 'clone', ddc_repo_name])
+
+  os.chdir(ddc_dir)
+  run_cmd(['git', 'fetch'])
+
+  os.chdir(src_dir)
+  run_cmd(['git', 'fetch'])
+  run_cmd(['git', 'stash'])
+  run_cmd(['git', 'checkout', '-B', repo_branch_parts[1], repo_branch])
+
+  # parse DEPS
+  deps = run_cmd(['cat', deps_file])
+  rev_num = {}
+  revision = '%s_rev":\s*"@(.+)"' % (repo)
+  rev_num = re.search(revision, deps).group(1)
+
+  # update repos
+  all_revs = []
+  os.chdir(ddc_dir)
+
+  output = run_cmd(["git", "log",  "--pretty=%H", "%s..HEAD" % (rev_num),
+      "origin/master"])
+  commits = output.split('\n')
+  if not commits or len(commits[0]) < 10:
+    print "DEPS is up-to-date."
+    sys.exit(0)
+
+  revision = commits[0]
+
+  history = run_cmd(["git", "log",  "--format=short", "%s..HEAD" % (rev_num),
+      "origin/master"])
+
+  print "Pending DEPS update: %s" % (revision)
+
+  # make the next DEPS update
+  os.chdir(src_dir)
+  run_cmd(['rm', deps_file])
+
+  pattern = re.compile('%s_rev":\s*"@(.+)"' % (repo))
+  new_deps = pattern.sub('%s_rev": "@%s"' % (repo, revision), deps)
+  write_file(deps_file, new_deps)
+
+  commit_log = 'DEPS AutoUpdate: %s\n\n' % (repo)
+  commit_log += history
+
+  write_file('commit_log.txt', commit_log)
+  run_cmd(['git', 'add', deps_file])
+
+  print run_cmd(['git', 'diff', 'HEAD'])
+  print
+  print "Commit log:"
+  print "---------------------------------------------"
+  print commit_log
+  print "---------------------------------------------"
+
+  if not options.force:
+    print "Ready to push; press Enter to continue or Control-C to abort..."
+    sys.stdin.readline()
+  print run_cmd(['git', 'commit', '-F', 'commit_log.txt'])
+  print run_cmd(['git', 'push', repo_branch_parts[0], repo_branch_parts[1]])
+  print "Done."
+
+
+if '__main__' == __name__:
+  main()