Let release scripts determine version based on tags.

tools/release/push_to_candidates.py

 #!/usr/bin/env python
 # Copyright 2013 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 17 matching lines @@
 
 import argparse
 import os
 import sys
 import tempfile
 import urllib2
 
 from common_includes import *
 
 PUSH_MSG_GIT_SUFFIX = " (based on %s)"
-PUSH_MSG_GIT_RE = re.compile(r".* \(based on (?P<git_rev>[a-fA-F0-9]+)\)$")
-VERSION_RE = re.compile(r"^\d+\.\d+\.\d+(?:\.\d+)?$")
+
 
 class Preparation(Step):
   MESSAGE = "Preparation."
 
   def RunStep(self):
     self.InitialEnvironmentChecks(self.default_cwd)
     self.CommonPrepare()
 
     if(self["current_branch"] == self.Config("CANDIDATESBRANCH")
        or self["current_branch"] == self.Config("BRANCHNAME")):
@@ skipping 16 matching lines @@
 
   def RunStep(self):
     if self._options.revision:
       self["push_hash"] = self._options.revision
     else:
       self["push_hash"] = self.GitLog(n=1, format="%H", git_hash="HEAD")
     if not self["push_hash"]:  # pragma: no cover
       self.Die("Could not determine the git hash for the push.")
 
 
-class DetectLastPush(Step):
-  MESSAGE = "Detect commit ID of last push to CANDIDATES."
-
-  def RunStep(self):
-    last_push = self._options.last_push or self.FindLastCandidatesPush()
-    while True:
-      # Print assumed commit, circumventing git's pager.

[Michael Achenbach, 2015/01/27 11:39:04]

This interaction was never used -> remove.

-      print self.GitLog(n=1, git_hash=last_push)
-      if self.Confirm(
-          "Is the commit printed above the last push to candidates?"):
-        break
-      last_push = self.FindLastCandidatesPush(parent_hash=last_push)
-
-    if self._options.last_master:
-      # Read the master revision of the last push from a command-line option.
-      last_push_master = self._options.last_master
-    else:
-      # Retrieve the master revision of the last push from the text in
-      # the push commit message.
-      last_push_title = self.GitLog(n=1, format="%s", git_hash=last_push)
-      last_push_master = PUSH_MSG_GIT_RE.match(
-          last_push_title).group("git_rev")
-
-      if not last_push_master:  # pragma: no cover
-        self.Die(
-            "Could not retrieve master git hash for candidates push %s"
-            % last_push)
-
-    # This points to the git hash of the last push on candidates.
-    self["last_push_candidates"] = last_push
-    # This points to the last master revision that went into the last
-    # push.
-    # TODO(machenbach): Do we need a check to make sure we're not pushing a
-    # revision older than the last push? If we do this, the output of the
-    # current change log preparation won't make much sense.
-    self["last_push_master"] = last_push_master
-
-
 class IncrementVersion(Step):
   MESSAGE = "Increment version number."
 
   def RunStep(self):
     latest_version = self.GetLatestVersion()
 
     # The version file on master can be used to bump up major/minor at
     # branch time.
     self.GitCheckoutFile(VERSION_FILE, self.vc.RemoteMasterBranch())
     self.ReadAndPersistVersion("master_")
@@ skipping 14 matching lines @@
     # Make sure patch level is 0 in a new push.
     self["new_patch"] = "0"
 
     self["version"] = "%s.%s.%s" % (self["new_major"],
                                     self["new_minor"],
                                     self["new_build"])
 
     print ("Incremented version to %s" % self["version"])
 
 
+class DetectLastRelease(Step):
+  MESSAGE = "Detect commit ID of last release base."
+
+  def RunStep(self):
+    if self._options.last_master:
+      self["last_push_master"] = self._options.last_master
+    else:
+      self["last_push_master"] = self.GetLatestReleaseBase()
+
+
 class PrepareChangeLog(Step):
   MESSAGE = "Prepare raw ChangeLog entry."
 
   def Reload(self, body):
     """Attempts to reload the commit message from rietveld in order to allow
     late changes to the LOG flag. Note: This is brittle to future changes of
     the web page name or structure.
     """
     match = re.search(r"^Review URL: https://codereview\.chromium\.org/(\d+)$",
                       body, flags=re.M)
@@ skipping 254 matching lines @@
           "/tmp/v8-push-to-candidates-tempfile-changelog-entry",
       "PATCH_FILE": "/tmp/v8-push-to-candidates-tempfile-patch-file",
       "COMMITMSG_FILE": "/tmp/v8-push-to-candidates-tempfile-commitmsg",
     }
 
   def _Steps(self):
     return [
       Preparation,
       FreshBranch,
       PreparePushRevision,
-      DetectLastPush,
       IncrementVersion,
+      DetectLastRelease,
       PrepareChangeLog,
       EditChangeLog,
       StragglerCommits,
       SquashCommits,
       NewBranch,
       ApplyChanges,
       CommitSquash,
       SanityCheck,
       Land,
       PrepareVersionBranch,
       AddChangeLog,
       SetVersion,
       CommitCandidate,
       Land,
       TagRevision,
       CleanUp,
     ]
 
 
 if __name__ == "__main__":  # pragma: no cover
   sys.exit(PushToCandidates().Run())