[release-tools] Tool to find related commits

tools/release/detectReverts.py

Index: tools/release/detectReverts.py
diff --git a/tools/release/detectReverts.py b/tools/release/detectReverts.py
new file mode 100755
index 0000000000000000000000000000000000000000..f29be50600e642057571a5af0d05ab09cb940d3d
--- /dev/null
+++ b/tools/release/detectReverts.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+# Copyright 2015 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.
+
+import argparse
+import os
+import sys
+
+from subprocess import call, Popen, PIPE
+
+def print_analysis(gitWorkingDir, hashToSearch, upperBound):

[Michael Achenbach, 2015/04/21 14:14:24]

nit: python var names

+
+  raw_output = git_execute(gitWorkingDir, ["rev-list", hashToSearch + ".." + upperBound])

[Michael Achenbach, 2015/04/21 14:14:24]

Suggestiong: you could use log on origin/master with --grep="[Rr]evert XXX" and
--format=%H

XXX stands for the way numbers or hashes would be regexped in grep - don't
recall that right now.

Then you have everything in one git call.

+
+  print 'test'
+  raw_output = raw_output.strip()
+  candidate_hashes = raw_output.split("\n")

[Michael Achenbach, 2015/04/21 14:14:24]

splitlines()

+  print "Found " + str(len(candidate_hashes)) + " candidates"
+  for candidate in candidate_hashes:
+    #git show -s --format=%B SHA1
+    current_message = git_execute(gitWorkingDir, ["show","-s", "--format=%B",candidate])
+    if ("Revert" in current_message) or ("revert" in current_message):
+      if hashToSearch in current_message:
+        print "Found revert in " + candidate
+
+  print "Finished"
+

[Michael Achenbach, 2015/04/21 14:14:24]

nit: two empty lines between things on toplevel

+def git_execute(workingDir, commands):

[Michael Achenbach, 2015/04/21 14:14:24]

working_dir

+  p = Popen(['git', '-C', workingDir] + commands, stdin=PIPE, stdout=PIPE, stderr=PIPE)
+  output, err = p.communicate()
+  rc = p.returncode
+  if rc != 0:
+    raise Exception(err)
+
+  return output
+
+if __name__ == "__main__":  # pragma: no cover
+  parser = argparse.ArgumentParser('Tool to check where a git commit was merged and reverted.')

[Michael Achenbach, 2015/04/21 14:14:24]

Is a tool for one commit useful? Why not a whole range of commits? E.g. B is
branch point. Tell me if there's anything interesting about commits in A..B
within the range B..C (where C might be HEAD) and where A might be the a commit
a week ago.

[Michael Achenbach, 2015/05/04 08:57:53]

Could you answer to this? Has that been done? The main description of the tool
is maybe a bit misleading.

+  parser.add_argument("-g", "--git-dir", required=False, default='.',
+                        help="The path to your git working directory.")

[Michael Achenbach, 2015/04/21 14:14:24]

nit: indentation

+
+  parser.add_argument('originalCommit', nargs=1, help="Hash of the commit to be searched.")
+  parser.add_argument('upperBound', nargs=1, help="branch when searching should stop.")
+
+  args = sys.argv[1:]
+  options = parser.parse_args(args)
+
+  sys.exit(print_analysis(options.git_dir, options.originalCommit[0], options.upperBound[0]))