[Release] Update merge script to leverage auto-tag bot

tools/release/merge_to_branch.py

 #!/usr/bin/env python
 # Copyright 2014 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
@@ skipping 29 matching lines @@
 
   def RunStep(self):
     if os.path.exists(self.Config("ALREADY_MERGING_SENTINEL_FILE")):
       if self._options.force:
         os.remove(self.Config("ALREADY_MERGING_SENTINEL_FILE"))
       elif self._options.step == 0:  # pragma: no cover
         self.Die("A merge is already in progress")
     open(self.Config("ALREADY_MERGING_SENTINEL_FILE"), "a").close()
 
     self.InitialEnvironmentChecks(self.default_cwd)
-    if self._options.branch:
-      self["merge_to_branch"] = self._options.branch
-    else:  # pragma: no cover
-      self.Die("Please specify a branch to merge to")
+
+    self["merge_to_branch"] = self._options.branch
 
     self.CommonPrepare()
     self.PrepareBranch()
 
 
 class CreateBranch(Step):
   MESSAGE = "Create a fresh branch for the patch."
 
   def RunStep(self):
     self.GitCreateBranch(self.Config("BRANCHNAME"),
                          self.vc.RemoteBranch(self["merge_to_branch"]))
 
 
 class SearchArchitecturePorts(Step):
   MESSAGE = "Search for corresponding architecture ports."
 
   def RunStep(self):
     self["full_revision_list"] = list(OrderedDict.fromkeys(
         self._options.revisions))
     port_revision_list = []
     for revision in self["full_revision_list"]:
       # Search for commits which matches the "Port XXX" pattern.
       git_hashes = self.GitLog(reverse=True, format="%H",
-                               grep="Port %s" % revision,
+                               grep="^[Pp]ort %s" % revision,
                                branch=self.vc.RemoteMasterBranch())
       for git_hash in git_hashes.splitlines():
         revision_title = self.GitLog(n=1, format="%s", git_hash=git_hash)
 
         # Is this revision included in the original revision list?
         if git_hash in self["full_revision_list"]:
           print("Found port of %s -> %s (already included): %s"
                 % (revision, git_hash, revision_title))
         else:
           print("Found port of %s -> %s: %s"
                 % (revision, git_hash, revision_title))
           port_revision_list.append(git_hash)
 
     # Do we find any port?
     if len(port_revision_list) > 0:
       if self.Confirm("Automatically add corresponding ports (%s)?"
                       % ", ".join(port_revision_list)):
         #: 'y': Add ports to revision list.
         self["full_revision_list"].extend(port_revision_list)
 
 
 class CreateCommitMessage(Step):
   MESSAGE = "Create commit message."
 
+  def _create_commit_description(self, commit_hash):
+    patch_merge_desc = self.GitLog(n=1, format="%s", git_hash=commit_hash)

[Michael Achenbach, 2016/07/21 13:56:37]

Is this done twice? E.g. below?

[Michael Hablich, 2016/07/21 14:27:33]

Done.

+    description = "Merged: " + patch_merge_desc + "\n"
+    description = description + "Revision: " + commit_hash + "\n\n"

[Michael Achenbach, 2016/07/21 13:56:37]

nit: description += ...

or to avoid multiple string buffers use % like

return "Merged: %s\nRevision: %s\n\n" % (patch_merge_desc, commit_hash)

[Michael Hablich, 2016/07/21 14:27:32]

Done.

+    return description
+
   def RunStep(self):
 
     # Stringify: ["abcde", "12345"] -> "abcde, 12345"
     self["revision_list"] = ", ".join(self["full_revision_list"])
 
     if not self["revision_list"]:  # pragma: no cover
       self.Die("Revision list is empty.")
 
-    action_text = "Merged %s"
+    msg_pieces = []
 
-    # The commit message title is added below after the version is specified.
-    msg_pieces = [
-      "\n".join(action_text % s for s in self["full_revision_list"]),
-    ]
-    msg_pieces.append("\n\n")
+    if len(self["full_revision_list"]) > 1:
+      self["commit_title"] = "Merged: Squashed multiple commits."
+    else:
+      commit_hash = self["full_revision_list"][0]
+      patch_merge_desc = self.GitLog(n=1, format="%s", git_hash=commit_hash)
+      title = "Merged: " + patch_merge_desc

[Michael Achenbach, 2016/07/21 13:56:37]

nit: inline title or also patch_merge_desc

[Michael Hablich, 2016/07/21 14:27:32]

Done.

+      self["commit_title"] = title
 
     for commit_hash in self["full_revision_list"]:
-      patch_merge_desc = self.GitLog(n=1, format="%s", git_hash=commit_hash)
-      msg_pieces.append("%s\n\n" % patch_merge_desc)
+      msg_pieces.append(self._create_commit_description(commit_hash))

[Michael Achenbach, 2016/07/21 13:56:37]

Don't we get a double title here?

[Michael Hablich, 2016/07/21 14:27:33]

Done.

 
     bugs = []
     for commit_hash in self["full_revision_list"]:
       msg = self.GitLog(n=1, git_hash=commit_hash)
       for bug in re.findall(r"^[ \t]*BUG[ \t]*=[ \t]*(.*?)[ \t]*$", msg, re.M):
         bugs.extend(s.strip() for s in bug.split(","))
     bug_aggregate = ",".join(sorted(filter(lambda s: s and s != "none", bugs)))
     if bug_aggregate:
       msg_pieces.append("BUG=%s\nLOG=N\n" % bug_aggregate)
 
     self["new_commit_msg"] = "".join(msg_pieces)
 
 
 class ApplyPatches(Step):
   MESSAGE = "Apply patches for selected revisions."
 
   def RunStep(self):
     for commit_hash in self["full_revision_list"]:
       print("Applying patch for %s to %s..."
             % (commit_hash, self["merge_to_branch"]))
       patch = self.GitGetPatch(commit_hash)
       TextToFile(patch, self.Config("TEMPORARY_PATCH_FILE"))
       self.ApplyPatch(self.Config("TEMPORARY_PATCH_FILE"))
     if self._options.patch:
       self.ApplyPatch(self._options.patch)
 
-
-class PrepareVersion(Step):
-  MESSAGE = "Prepare version file."
-
-  def RunStep(self):
-    # This is used to calculate the patch level increment.
-    self.ReadAndPersistVersion()
-
-
-class IncrementVersion(Step):
-  MESSAGE = "Increment version number."
-
-  def RunStep(self):
-    new_patch = str(int(self["patch"]) + 1)
-    if self.Confirm("Automatically increment V8_PATCH_LEVEL? (Saying 'n' will "
-                    "fire up your EDITOR on %s so you can make arbitrary "
-                    "changes. When you're done, save the file and exit your "
-                    "EDITOR.)" % VERSION_FILE):
-      text = FileToText(os.path.join(self.default_cwd, VERSION_FILE))
-      text = MSub(r"(?<=#define V8_PATCH_LEVEL)(?P<space>\s+)\d*$",
-                  r"\g<space>%s" % new_patch,
-                  text)
-      TextToFile(text, os.path.join(self.default_cwd, VERSION_FILE))
-    else:
-      self.Editor(os.path.join(self.default_cwd, VERSION_FILE))
-    self.ReadAndPersistVersion("new_")
-    self["version"] = "%s.%s.%s.%s" % (self["new_major"],
-                                       self["new_minor"],
-                                       self["new_build"],
-                                       self["new_patch"])
-
-
 class CommitLocal(Step):
   MESSAGE = "Commit to local branch."
 
   def RunStep(self):
     # Add a commit message title.
-    self["commit_title"] = "Version %s (cherry-pick)" % self["version"]
     self["new_commit_msg"] = "%s\n\n%s" % (self["commit_title"],
                                            self["new_commit_msg"])
     TextToFile(self["new_commit_msg"], self.Config("COMMITMSG_FILE"))
     self.GitCommit(file_name=self.Config("COMMITMSG_FILE"))
 
+class AddInformationalComment(Step):
+  MESSAGE = 'Show additional information.'
+
+  def RunStep(self):
+    message = ("Please note that you are using a new "

[Michael Achenbach, 2016/07/21 13:56:38]

Suggestion for making this readable to lazy devs: Remove first and last
sentence. E.g.:

NOTE: This script will no longer update include/v8-version.h and create a tag.
This is done automatically by the autotag bot. See 'merge_to_branch.py --help'
for more details.

[Michael Hablich, 2016/07/21 14:27:33]

Done.

+     "version of the script merge_to_branch.py. "
+     "This script will no longer automatically update include/v8-version.h "
+     "and create a tag. This is ok, the trustworthy autotag bot will "
+     "take care of that. The old script is still available in "
+     "tools/release/roll_merge.py.")
+
+    self.GitCLAddComment(message)
 
 class CommitRepository(Step):
   MESSAGE = "Commit to the repository."
 
   def RunStep(self):
     self.GitCheckout(self.Config("BRANCHNAME"))
     self.WaitForLGTM()
     self.GitPresubmit()
     self.vc.CLLand()
 
-
-class TagRevision(Step):
-  MESSAGE = "Create the tag."
-
-  def RunStep(self):
-    print "Creating tag %s" % self["version"]
-    self.vc.Tag(self["version"],
-                self.vc.RemoteBranch(self["merge_to_branch"]),
-                self["commit_title"])
-
-
 class CleanUp(Step):
   MESSAGE = "Cleanup."
 
   def RunStep(self):
     self.CommonCleanup()
     print "*** SUMMARY ***"
-    print "version: %s" % self["version"]
     print "branch: %s" % self["merge_to_branch"]
     if self["revision_list"]:
       print "patches: %s" % self["revision_list"]
 
 
 class MergeToBranch(ScriptsBase):
   def _Description(self):
     return ("Performs the necessary steps to merge revisions from "

[Michael Achenbach, 2016/07/21 13:56:38]

Suggestion: Add more details here including all relevant information about
version file, auto tagging, etc.

[Michael Hablich, 2016/07/21 14:27:33]

Done.

-            "master to other branches, including candidates.")
+            "master to release branches like 4.5.")
 
   def _PrepareOptions(self, parser):
     group = parser.add_mutually_exclusive_group(required=True)
     group.add_argument("--branch", help="The branch to merge to.")
     parser.add_argument("revisions", nargs="*",
                         help="The revisions to merge.")
     parser.add_argument("-f", "--force",
                         help="Delete sentinel file.",
                         default=False, action="store_true")
     parser.add_argument("-m", "--message",
                         help="A commit message for the patch.")
     parser.add_argument("-p", "--patch",
                         help="A patch file to apply as part of the merge.")
 
   def _ProcessOptions(self, options):
     if len(options.revisions) < 1:
       if not options.patch:
         print "Either a patch file or revision numbers must be specified"
         return False
       if not options.message:
         print "You must specify a merge comment if no patches are specified"
         return False
     options.bypass_upload_hooks = True
     # CC ulan to make sure that fixes are merged to Google3.
     options.cc = "ulan@chromium.org"
 
+    # This script only supports official release branches, not roll branches

[Michael Achenbach, 2016/07/21 13:56:37]

nit: Comment is redundant to print message. Rather drop it.

[Michael Hablich, 2016/07/21 14:27:33]

Done.

+    if len(options.branch.split('.')) > 2:
+      print ("This script does not support merging to roll branches (yet). "

[Michael Achenbach, 2016/07/21 13:56:37]

nit: remove 'yet' to avoid embarrassment when it's still the same in two years
:).

[Michael Hablich, 2016/07/21 14:27:32]

Done.

+            "Please use tools/release/roll_merge.py for this use case.")

[Michael Achenbach, 2016/07/21 13:56:37]

nit indentation - one space more...

[Michael Hablich, 2016/07/21 14:27:33]

Done.

+      return False
+
     # Make sure to use git hashes in the new workflows.
     for revision in options.revisions:
       if (IsSvnNumber(revision) or
           (revision[0:1] == "r" and IsSvnNumber(revision[1:]))):
         print "Please provide full git hashes of the patches to merge."
         print "Got: %s" % revision
         return False
     return True
 
   def _Config(self):
     return {
       "BRANCHNAME": "prepare-merge",
       "PERSISTFILE_BASENAME": "/tmp/v8-merge-to-branch-tempfile",
       "ALREADY_MERGING_SENTINEL_FILE":
           "/tmp/v8-merge-to-branch-tempfile-already-merging",
       "TEMPORARY_PATCH_FILE": "/tmp/v8-prepare-merge-tempfile-temporary-patch",
       "COMMITMSG_FILE": "/tmp/v8-prepare-merge-tempfile-commitmsg",
     }
 
   def _Steps(self):
     return [
       Preparation,
       CreateBranch,
       SearchArchitecturePorts,
       CreateCommitMessage,
       ApplyPatches,
-      PrepareVersion,
-      IncrementVersion,
       CommitLocal,
       UploadStep,
+      AddInformationalComment,
       CommitRepository,
-      TagRevision,
       CleanUp,
     ]
 
 
 if __name__ == "__main__":  # pragma: no cover
   sys.exit(MergeToBranch().Run())