Introduct git-auto-svn

This tool can automatically set up the necessary git-svn metadata for our
repos that live in SVN but are mirrored to Chrome.

R=iannucci@chromium.org, tandrii@chromium.org
BUG=418973

Review URL: https://codereview.chromium.org/611253003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@292241 0039d316-1c4b-4281-b951-d872f2087c98

git-auto-svn

+#!/usr/bin/env bash
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# git_map_branches.py -- a git-command for presenting a graphical view of git
+# branches in the current repo, and their relationships to each other.
+
+. $(type -P python_git_runner.sh)

git_auto_svn.py

+#!/usr/bin/env python
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Performs all git-svn setup steps necessary for 'git svn dcommit' to work.
+
+Assumes that trunk of the svn remote maps to master of the git remote.
+
+Example:
+git clone https://chromium.googlesource.com/chromium/tools/depot_tools
+cd depot_tools
+git auto-svn
+"""
+
+import argparse
+import os
+import sys
+import urlparse
+
+import subprocess2
+
+from git_common import run as run_git
+from git_common import run_stream as run_git_stream
+from git_common import set_config, root, ROOT
+from git_footers import parse_footers, get_unique, GIT_SVN_ID_PATTERN
+
+
+SVN_EXE = ROOT+'\\svn.bat' if sys.platform.startswith('win') else 'svn'
+
+
+def run_svn(*cmd, **kwargs):
+  """Runs an svn command.
+
+  Returns (stdout, stderr) as a pair of strings.
+
+  Raises subprocess2.CalledProcessError on nonzero return code.
+  """
+  kwargs.setdefault('stdin', subprocess2.PIPE)
+  kwargs.setdefault('stdout', subprocess2.PIPE)
+  kwargs.setdefault('stderr', subprocess2.PIPE)
+
+  cmd = (SVN_EXE,) + cmd
+  proc = subprocess2.Popen(cmd, **kwargs)
+  ret, err = proc.communicate()
+  retcode = proc.wait()
+  if retcode != 0:
+    raise subprocess2.CalledProcessError(retcode, cmd, os.getcwd(), ret, err)
+
+  return ret, err
+
+
+def main(argv):
+  # No command line flags. Just use the parser to prevent people from trying
+  # to pass flags that don't do anything, and to provide 'usage'.
+  parser = argparse.ArgumentParser(
+      description='Automatically set up git-svn for a repo mirrored from svn.')
+  parser.parse_args(argv[1:])
+
+  upstream = root()
+  message = run_git('log', '-1', '--format=%B', upstream)
+  footers = parse_footers(message)
+  git_svn_id = get_unique(footers, 'git-svn-id')
+  match = GIT_SVN_ID_PATTERN.match(git_svn_id)
+  assert match, 'No valid git-svn-id footer found on %s.' % upstream
+  print 'Found git-svn-id footer %s on %s' % (match.group(1), upstream)
+
+  parsed_svn = urlparse.urlparse(match.group(1))
+  path_components = parsed_svn.path.split('/')
+  svn_repo = None
+  svn_path = None
+  for i in xrange(len(path_components)):
+    try:
+      maybe_repo = '%s://%s%s' % (
+          parsed_svn.scheme, parsed_svn.netloc, '/'.join(path_components[:i+1]))
+      print 'Checking ', maybe_repo
+      run_svn('info', maybe_repo)
+      svn_repo = maybe_repo
+      svn_path = '/'.join(path_components[i+1:])
+      break
+    except subprocess2.CalledProcessError:
+      continue
+  assert svn_repo is not None, 'Unable to find svn repo for %s' % match.group(1)
+  print 'Found upstream svn repo %s and path %s' % (svn_repo, svn_path)
+
+  prefix = upstream.rsplit('/')[0]
+  run_git('svn', 'init', '--prefix=%s' % prefix, '-T', svn_path, svn_repo)
+  set_config('svn-remote.svn.fetch',
+             '%s:refs/remotes/%s' % (svn_path, upstream))
+  print 'Configured metadata, running "git svn fetch". This may take some time.'
+  for line in run_git_stream('svn', 'fetch').xreadlines():
+    print line.strip()
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))

git_common.py

@@ -319,15 +319,6 @@ def branches(*args):
     yield line.split()[-1]
 
 
-def run_with_retcode(*cmd, **kwargs):
-  """Run a command but only return the status code."""
-  try:
-    run(*cmd, **kwargs)
-    return 0
-  except subprocess2.CalledProcessError as cpe:
-    return cpe.returncode
-
-
 def config(option, default=None):
   try:
     return run('config', '--get', option) or default
@@ -551,6 +542,15 @@ def run(*cmd, **kwargs):
   return run_with_stderr(*cmd, **kwargs)[0]
 
 
+def run_with_retcode(*cmd, **kwargs):
+  """Run a command but only return the status code."""
+  try:
+    run(*cmd, **kwargs)
+    return 0
+  except subprocess2.CalledProcessError as cpe:
+    return cpe.returncode
+
+
 def run_stream(*cmd, **kwargs):
   """Runs a git command. Returns stdout as a PIPE (file-like object).
 
@@ -600,6 +600,7 @@ def set_branch_config(branch, option, value, scope='local'):
 def set_config(option, value, scope='local'):
   run('config', '--' + scope, option, value)
 
+
 def squash_current_branch(header=None, merge_base=None):
   header = header or 'git squash commit.'
   merge_base = merge_base or get_or_create_merge_base(current_branch())
@@ -723,6 +724,7 @@ def upstream(branch):
   except subprocess2.CalledProcessError:
     return None
 
+
 def get_git_version():
   """Returns a tuple that contains the numeric components of the current git
   version."""

git_footers.py

@@ -11,10 +11,12 @@ from collections import defaultdict
 
 import git_common as git
 
+
 FOOTER_PATTERN = re.compile(r'^\s*([\w-]+): (.*)$')
 CHROME_COMMIT_POSITION_PATTERN = re.compile(r'^([\w/-]+)@{#(\d+)}$')
 GIT_SVN_ID_PATTERN = re.compile('^([^\s@]+)@(\d+)')
 
+
 def normalize_name(header):
   return '-'.join([ word.title() for word in header.strip().split('-') ])
 

man/man1/git-auto-svn.1

+'\" t
+.\"     Title: git-auto-svn
+.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
+.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
+.\"      Date: 09/30/2014
+.\"    Manual: Chromium depot_tools Manual
+.\"    Source: depot_tools 2bbacdc
+.\"  Language: English
+.\"
+.TH "GIT\-AUTO\-SVN" "1" "09/30/2014" "depot_tools 2bbacdc" "Chromium depot_tools Manual"
+.\" -----------------------------------------------------------------
+.\" * Define some portability stuff
+.\" -----------------------------------------------------------------
+.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.\" http://bugs.debian.org/507673
+.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
+.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.ie \n(.g .ds Aq \(aq
+.el       .ds Aq '
+.\" -----------------------------------------------------------------
+.\" * set default formatting
+.\" -----------------------------------------------------------------
+.\" disable hyphenation
+.nh
+.\" disable justification (adjust text to left margin only)
+.ad l
+.\" -----------------------------------------------------------------
+.\" * MAIN CONTENT STARTS HERE *
+.\" -----------------------------------------------------------------
+.SH "NAME"
+git-auto-svn \- Automatically set up git\-svn metadata for a repo mirrored from SVN\&.
+.SH "SYNOPSIS"
+.sp
+.nf
+\fIgit auto\-svn\fR
+.fi
+.sp
+.SH "DESCRIPTION"
+.sp
+git auto\-svn automatically sets up git\-svn metadata and runs git\-svn fetch for repos that are homed in SVN but mirrored to Git (such as depot_tools itself)\&.
+.sp
+It determines the metadata to use by inspecting the git\-svn\-id footer of the HEAD of the remote upstream ref (by default, origin/master)\&. git\-svn\-id footers look like this:
+.sp
+.if n \{\
+.RS 4
+.\}
+.nf
+git\-svn\-id: svn://some\&.host\&.org/repo/path/to/a/sub/folder@123456 0039d316\-1c4b\-4281\-b951\-d872f2087c98
+.fi
+.if n \{\
+.RE
+.\}
+.sp
+git auto\-svn extracts the repository url (svn://some\&.host\&.org/repo/path/to/a/sub/folder) from the git\-svn\-id, and splits it into the root repository (svn://some\&.host\&.org/repo) and the path within that repository (/path/to/a/sub/folder)\&.
+.sp
+It then sets up the following stanza in \&.git/config:
+.sp
+.if n \{\
+.RS 4
+.\}
+.nf
+[svn\-remote "svn"]
+    url = svn://some\&.host\&.org/repo
+    fetch = path/to/a/sub/folder:refs/remotes/origin/master
+.fi
+.if n \{\
+.RE
+.\}
+.sp
+Finally, it runs git svn fetch to pull in the data from the svn remote\&.
+.SH "CONFIGURATION VARIABLES"
+.SS "svn\-remote\&.svn\&.url"
+.sp
+This is the url of the root of the remote svn repository\&.
+.SS "svn\-remote\&.svn\&.fetch"
+.sp
+This looks like a git refspec, but maps a subdirectory of the svn repository to a single ref in the git remote\&.
+.SH "EXAMPLE"
+.sp
+.if n \{\
+.RS 4
+.\}
+.nf
+git clone https://chromium\&.googlesource\&.com/chromium/tools/depot_tools
+cd depot_tools
+git auto\-svn
+.fi
+.if n \{\
+.RE
+.\}
+.sp
+This results in the following stanza in depot_tools/\&.git/config:
+.sp
+.if n \{\
+.RS 4
+.\}
+.nf
+[svn\-remote "svn"]
+    url = svn://svn\&.chromium\&.org/chrome
+    fetch = trunk/tools/depot_tools:refs/remotes/origin/master
+.fi
+.if n \{\
+.RE
+.\}
+.SH "CHROMIUM DEPOT_TOOLS"
+.sp
+Part of the chromium \fBdepot_tools\fR(7) suite\&. These tools are meant to assist with the development of chromium and related projects\&. Download the tools from \m[blue]\fBhere\fR\m[]\&\s-2\u[1]\d\s+2\&.
+.SH "NOTES"
+.IP " 1." 4
+here
+.RS 4
+\%https://chromium.googlesource.com/chromium/tools/depot_tools.git
+.RE

man/src/_git-auto-svn_desc.helper.txt

+Automatically set up git-svn metadata for a repo mirrored from SVN.

man/src/git-auto-svn.txt

+git-auto-svn(1)
+===============
+
+NAME
+----
+git-auto-svn -
+include::_git-auto-svn_desc.helper.txt[]
+
+SYNOPSIS
+--------
+[verse]
+'git auto-svn'
+
+DESCRIPTION
+-----------
+
+`git auto-svn` automatically sets up git-svn metadata and runs git-svn fetch for
+repos that are homed in SVN but mirrored to Git (such as depot_tools itself).
+
+It determines the metadata to use by inspecting the `git-svn-id` footer of the
+HEAD of the remote upstream ref (by default, `origin/master`). `git-svn-id`
+footers look like this:
+
+  git-svn-id: svn://some.host.org/repo/path/to/a/sub/folder@123456 0039d316-1c4b-4281-b951-d872f2087c98
+
+`git auto-svn` extracts the repository url
+(svn://some.host.org/repo/path/to/a/sub/folder) from the `git-svn-id`, and
+splits it into the root repository (svn://some.host.org/repo) and the path
+within that repository (/path/to/a/sub/folder).
+
+It then sets up the following stanza in .git/config:
+
+  [svn-remote "svn"]
+      url = svn://some.host.org/repo
+      fetch = path/to/a/sub/folder:refs/remotes/origin/master
+
+Finally, it runs `git svn fetch` to pull in the data from the svn remote.
+
+CONFIGURATION VARIABLES
+-----------------------
+
+svn-remote.svn.url
+~~~~~~~~~~~~~~~~~~
+
+This is the url of the root of the remote svn repository.
+
+svn-remote.svn.fetch
+~~~~~~~~~~~~~~~~~~~~
+
+This looks like a git refspec, but maps a subdirectory of the svn repository
+to a single ref in the git remote.
+
+EXAMPLE
+-------
+
+  git clone https://chromium.googlesource.com/chromium/tools/depot_tools
+  cd depot_tools
+  git auto-svn
+
+This results in the following stanza in `depot_tools/.git/config`:
+
+  [svn-remote "svn"]
+      url = svn://svn.chromium.org/chrome
+      fetch = trunk/tools/depot_tools:refs/remotes/origin/master
+
+
+include::_footer.txt[]
+
+// vim: ft=asciidoc:

man/src/make_docs.sh

@@ -23,6 +23,7 @@ ensure_in_path() {
 }
 
 ensure_in_path xmlto
+ensure_in_path hg
 
 DFLT_CATALOG_PATH="/usr/local/etc/xml/catalog"
 if [[ ! $XML_CATALOG_FILES && -f "$DFLT_CATALOG_PATH" ]]