blob: cca1f40d55b982588958fd041a2d64ff3c717e1b [file] [log] [blame]
#!/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.
# for py2/py3 compatibility
from __future__ import print_function
import argparse
import subprocess
import sys
def GetArgs():
parser = argparse.ArgumentParser(
description="Finds a commit that a given patch can be applied to. "
"Does not actually apply the patch or modify your checkout "
"in any way.")
parser.add_argument("patch_file", help="Patch file to match")
"--branch", "-b", default="origin/master", type=str,
help="Git tree-ish where to start searching for commits, "
"default: %(default)s")
"--limit", "-l", default=500, type=int,
help="Maximum number of commits to search, default: %(default)s")
"--verbose", "-v", default=False, action="store_true",
help="Print verbose output for your entertainment")
return parser.parse_args()
def FindFilesInPatch(patch_file):
files = {}
next_file = ""
with open(patch_file) as patch:
for line in patch:
if line.startswith("diff --git "):
# diff --git a/src/ b/src/
words = line.split()
assert words[2].startswith("a/") and len(words[2]) > 2
next_file = words[2][2:]
elif line.startswith("index "):
# index add3e61..d1bbf6a 100644
hashes = line.split()[1]
old_hash = hashes.split("..")[0]
if old_hash.startswith("0000000"): continue # Ignore new files.
files[next_file] = old_hash
return files
def GetGitCommitHash(treeish):
cmd = ["git", "log", "-1", "--format=%H", treeish]
return subprocess.check_output(cmd).strip()
def CountMatchingFiles(commit, files):
matched_files = 0
# Calling out to git once and parsing the result Python-side is faster
# than calling 'git ls-tree' for every file.
cmd = ["git", "ls-tree", "-r", commit] + [f for f in files]
output = subprocess.check_output(cmd)
for line in output.splitlines():
# 100644 blob c6d5daaa7d42e49a653f9861224aad0a0244b944 src/
_, _, actual_hash, filename = line.split()
expected_hash = files[filename]
if actual_hash.startswith(expected_hash): matched_files += 1
return matched_files
def FindFirstMatchingCommit(start, files, limit, verbose):
commit = GetGitCommitHash(start)
num_files = len(files)
if verbose: print(">>> Found %d files modified by patch." % num_files)
for _ in range(limit):
matched_files = CountMatchingFiles(commit, files)
if verbose: print("Commit %s matched %d files" % (commit, matched_files))
if matched_files == num_files:
return commit
commit = GetGitCommitHash("%s^" % commit)
print("Sorry, no matching commit found. "
"Try running 'git fetch', specifying the correct --branch, "
"and/or setting a higher --limit.")
if __name__ == "__main__":
args = GetArgs()
files = FindFilesInPatch(args.patch_file)
commit = FindFirstMatchingCommit(args.branch, files, args.limit, args.verbose)
if args.verbose:
print(">>> Matching commit: %s" % commit)
print(subprocess.check_output(["git", "log", "-1", commit]))
print(">>> Kthxbai.")