Partially reland Auto-generate v8 version based on tags.

tools/push-to-trunk/generate_version.py

Index: tools/push-to-trunk/generate_version.py
diff --git a/tools/push-to-trunk/generate_version.py b/tools/push-to-trunk/generate_version.py
deleted file mode 100755
index b4a0221eae5c10224a18d79bf8067ca3df958177..0000000000000000000000000000000000000000
--- a/tools/push-to-trunk/generate_version.py
+++ /dev/null
@@ -1,78 +0,0 @@
-#!/usr/bin/env python
-# Copyright 2014 the V8 project authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-"""
-Script to set v8's version file to the version given by the latest tag.
-"""
-
-
-import os
-import re
-import subprocess
-import sys
-
-
-CWD = os.path.abspath(
-    os.path.dirname(os.path.dirname(os.path.dirname(__file__))))
-VERSION_CC = os.path.join(CWD, "src", "version.cc")
-
-def main():
-  tag = subprocess.check_output(
-      "git describe --tags",
-      shell=True,
-      cwd=CWD,
-  ).strip()
-  assert tag
-
-  # Check for commits not exactly matching a tag. Those are candidate builds
-  # for the next version. The output has the form
-  # <tag name>-<n commits>-<hash>.
-  if "-" in tag:
-    version = tag.split("-")[0]
-    candidate = "1"
-  else:
-    version = tag
-    candidate = "0"
-  version_levels = version.split(".")
-
-  # Set default patch level if none is given.
-  if len(version_levels) == 3:
-    version_levels.append("0")
-  assert len(version_levels) == 4
-
-  major, minor, build, patch = version_levels
-
-  # Increment build level for candidate builds.
-  if candidate == "1":
-    build = str(int(build) + 1)
-    patch = "0"
-
-  # Modify version.cc with the new values.
-  with open(VERSION_CC, "r") as f:
-    text = f.read()
-  output = []
-  for line in text.split("\n"):
-    for definition, substitute in (
-        ("MAJOR_VERSION", major),
-        ("MINOR_VERSION", minor),
-        ("BUILD_NUMBER", build),
-        ("PATCH_LEVEL", patch),
-        ("IS_CANDIDATE_VERSION", candidate)):
-      if line.startswith("#define %s" % definition):
-        line =  re.sub("\d+$", substitute, line)
-    output.append(line)
-  with open(VERSION_CC, "w") as f:
-    f.write("\n".join(output))
-
-  # Log what was done.
-  candidate_txt = " (candidate)" if candidate == "1" else ""
-  patch_txt = ".%s" % patch if patch != "0" else ""
-  version_txt = ("%s.%s.%s%s%s" %
-                 (major, minor, build, patch_txt, candidate_txt))
-  print "Modified version.cc. Set V8 version to %s" %  version_txt
-  return 0
-
-if __name__ == "__main__":
-  sys.exit(main())