Add script for rolling the inspector protocol to V8.

This is a tweaked version of the script that I just added to Chromium:

https://cs.chromium.org/chromium/src/third_party/inspector_protocol/roll.py

Change-Id: I21566f2472c20ecfd713996974c0833b7988a122
Reviewed-on: https://chromium-review.googlesource.com/c/1469376
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59609}

third_party/inspector_protocol/roll.py

@@ -0,0 +1,162 @@
+#!/usr/bin/env python
+# Copyright 2019 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import argparse
+import sys
+import os
+import subprocess
+import glob
+import shutil
+
+
+FILES_TO_SYNC = [
+    'README.md',
+    'check_protocol_compatibility.py',
+    'code_generator.py',
+    'concatenate_protocols.py',
+    'convert_protocol_to_json.py',
+    'inspector_protocol.gni',
+    'inspector_protocol.gypi',
+    'lib/*',
+    'pdl.py',
+    'templates/*',
+]
+
+
+def RunCmd(cmd):
+  p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+  (stdoutdata, stderrdata) = p.communicate()
+  if p.returncode != 0:
+    raise Exception('%s: exit status %d', str(cmd), p.returncode)
+  return stdoutdata
+
+
+def CheckRepoIsClean(path, suffix):
+  os.chdir(path)  # As a side effect this also checks for existence of the dir.
+  # If path isn't a git repo, this will throw and exception.
+  # And if it is a git repo and 'git status' has anything interesting to say,
+  # then it's not clean (uncommitted files etc.)
+  if len(RunCmd(['git', 'status', '--porcelain'])) != 0:
+    raise Exception('%s is not a clean git repo (run git status)' % path)
+  if not path.endswith(suffix):
+    raise Exception('%s does not end with /%s' % (path, suffix))
+
+
+def CheckRepoIsNotAtMasterBranch(path):
+  os.chdir(path)
+  stdout = RunCmd(['git', 'rev-parse', '--abbrev-ref', 'HEAD']).strip()
+  if stdout == 'master':
+    raise Exception('%s is at master branch - refusing to copy there.' % path)
+
+
+def CheckRepoIsV8Checkout(path):
+  os.chdir(path)
+  if (RunCmd(['git', 'config', '--get', 'remote.origin.url']).strip() !=
+      'https://chromium.googlesource.com/v8/v8.git'):
+    raise Exception('%s is not a proper V8 checkout.' % path)
+
+
+def CheckRepoIsInspectorProtocolCheckout(path):
+  os.chdir(path)
+  if (RunCmd(['git', 'config', '--get', 'remote.origin.url']).strip() !=
+      'https://chromium.googlesource.com/deps/inspector_protocol.git'):
+    raise Exception('%s is not a proper inspector_protocol checkout.' % path)
+
+
+def FindFilesToSyncIn(path):
+  files = []
+  for f in FILES_TO_SYNC:
+    files += glob.glob(os.path.join(path, f))
+  files = [os.path.relpath(f, path) for f in files]
+  return files
+
+
+def FilesAreEqual(path1, path2):
+  # We check for permissions (useful for executable scripts) and contents.
+  return (os.stat(path1).st_mode == os.stat(path2).st_mode and
+          open(path1).read() == open(path2).read())
+
+
+def GetHeadRevision(path):
+  os.chdir(path)
+  return RunCmd(['git', 'rev-parse', 'HEAD'])
+
+
+def main(argv):
+  parser = argparse.ArgumentParser(description=(
+      "Rolls the inspector_protocol project (upstream) into V8's "
+      "third_party (downstream)."))
+  parser.add_argument("--ip_src_upstream",
+                      help="The inspector_protocol (upstream) tree.",
+                      default="~/ip/src")
+  parser.add_argument("--v8_src_downstream",
+                      help="The V8 src tree.",
+                      default="~/v8/v8")
+  parser.add_argument('--reverse', dest='reverse', action='store_true',
+                      help=("Whether to roll the opposite direction, from "
+                            "V8 (downstream) to inspector_protocol "
+                            "(upstream)."))
+  parser.set_defaults(reverse=False)
+  parser.add_argument('--force', dest='force', action='store_true',
+                      help=("Whether to carry out the modifications "
+                            "in the destination tree."))
+  parser.set_defaults(force=False)
+
+  args = parser.parse_args(argv)
+  upstream = os.path.normpath(os.path.expanduser(args.ip_src_upstream))
+  downstream = os.path.normpath(os.path.expanduser(
+      args.v8_src_downstream))
+  CheckRepoIsClean(upstream, '/src')
+  CheckRepoIsClean(downstream, '/v8')
+  CheckRepoIsInspectorProtocolCheckout(upstream)
+  CheckRepoIsV8Checkout(downstream)
+  # Check that the destination Git repo isn't at the master branch - it's
+  # generally a bad idea to check into the master branch, so we catch this
+  # common pilot error here early.
+  if args.reverse:
+    CheckRepoIsNotAtMasterBranch(upstream)
+    src_dir = os.path.join(downstream, 'third_party/inspector_protocol')
+    dest_dir = upstream
+  else:
+    CheckRepoIsNotAtMasterBranch(downstream)
+    src_dir = upstream
+    dest_dir = os.path.join(downstream, 'third_party/inspector_protocol')
+  print 'Rolling %s into %s ...' % (src_dir, dest_dir)
+  src_files = set(FindFilesToSyncIn(src_dir))
+  dest_files = set(FindFilesToSyncIn(dest_dir))
+  to_add = [f for f in src_files if f not in dest_files]
+  to_delete = [f for f in dest_files if f not in src_files]
+  to_copy = [f for f in src_files
+             if (f in dest_files and not FilesAreEqual(
+                 os.path.join(src_dir, f), os.path.join(dest_dir, f)))]
+  print 'To add: %s' % to_add
+  print 'To delete: %s' % to_delete
+  print 'To copy: %s' % to_copy
+  if not to_add and not to_delete and not to_copy:
+    print 'Nothing to do. You\'re good.'
+    sys.exit(0)
+  if not args.force:
+    print 'Rerun with --force if you wish the modifications to be done.'
+    sys.exit(1)
+  print 'You said --force ... as you wish, modifying the destination.'
+  for f in to_add + to_copy:
+    shutil.copyfile(os.path.join(src_dir, f), os.path.join(dest_dir, f))
+    shutil.copymode(os.path.join(src_dir, f), os.path.join(dest_dir, f))
+  for f in to_delete:
+    os.unlink(os.path.join(dest_dir, f))
+  if not args.reverse:
+    head_revision = GetHeadRevision(upstream)
+    lines = open(os.path.join(dest_dir, 'README.v8')).readlines()
+    f = open(os.path.join(dest_dir, 'README.v8'), 'w')
+    for line in lines:
+      if line.startswith('Revision: '):
+        f.write('Revision: %s' % head_revision)
+      else:
+        f.write(line)
+    f.close()
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))