Unify the version string to be displayed on "About Chromium" dialog.

build/util/lastchange.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """
 lastchange.py -- Chromium revision fetching utility.
 """
 
 import re
@@ skipping 84 matching lines @@
     a VersionInfo object or None on error.
   """
   proc = RunGitCommand(directory, ['rev-parse', 'HEAD'])
   if proc:
     output = proc.communicate()[0].strip()
     if proc.returncode == 0 and output:
       return VersionInfo('git', 'git', output[:7])
   return None
 
 
-def IsGitSVN(directory):
-  """
-  Checks whether git-svn has been set up.
-
-  Errors are swallowed.
-
-  Returns:
-    whether git-svn has been set up.
-  """
-  # To test whether git-svn has been set up, query the config for any
-  # svn-related configuration.  This command exits with an error code
-  # if there aren't any matches, so ignore its output.
-  proc = RunGitCommand(directory, ['config', '--get-regexp', '^svn'])
-  if proc:
-    return (proc.wait() == 0)
-  return False
-
-
-def FetchGitSVNURL(directory):
-  """
-  Fetch URL of SVN repository bound to git.
-
-  Errors are swallowed.
-
-  Returns:
-    SVN URL.
-  """
-  if IsGitSVN(directory):
-    proc = RunGitCommand(directory, ['svn', 'info', '--url'])
-    if proc:
-      output = proc.communicate()[0].strip()
-      if proc.returncode == 0:
-        match = re.search(r'^\w+://.*$', output, re.M)
-        if match:
-          return match.group(0)
-  return ''
-
-
-def FetchGitSVNRoot(directory):
-  """
-  Fetch root of SVN repository bound to git.
-
-  Errors are swallowed.
-
-  Returns:
-    SVN root repository.
-  """
-  if IsGitSVN(directory):
-    git_command = ['config', '--get-regexp', '^svn-remote.svn.url$']
-    proc = RunGitCommand(directory, git_command)
-    if proc:
-      output = proc.communicate()[0].strip()
-      if proc.returncode == 0:
-        # Zero return code implies presence of requested configuration variable.
-        # Its value is second (last) field of output.
-        match = re.search(r'\S+$', output)
-        if match:
-          return match.group(0)
-  return ''
-
-
-def LookupGitSVNRevision(directory, depth):
-  """
-  Fetch the Git-SVN identifier for the local tree.
-  Parses first |depth| commit messages.
-
-  Errors are swallowed.
-  """
-  if not IsGitSVN(directory):
-    return None
-  git_re = re.compile(r'^\s*git-svn-id:\s+(\S+)@(\d+)')
-  proc = RunGitCommand(directory, ['log', '-' + str(depth)])
-  if proc:
-    for line in proc.stdout:
-      match = git_re.match(line)
-      if match:
-        id = match.group(2)
-        if id:
-          proc.stdout.close()  # Cut pipe for fast exit.
-          return id
-  return None
-
-
-def IsGitSVNDirty(directory):
-  """
-  Checks whether our git-svn tree contains clean trunk or some branch.
-
-  Errors are swallowed.
-  """
-  # For git branches the last commit message is either
-  # some local commit or a merge.
-  return LookupGitSVNRevision(directory, 1) is None
-
-
 def FetchGitSVNRevision(directory):
   """
-  Fetch the Git-SVN identifier for the local tree.
+  Fetch the SVN revision for a given directory through Git.
 
   Errors are swallowed.
   """
-  # We assume that at least first 999 commit messages contain svn evidence.
-  revision = LookupGitSVNRevision(directory, 999)
-  if not revision:
-    return None
-  if IsGitSVNDirty(directory):
-    revision = revision + '-dirty'
-  url = FetchGitSVNURL(directory)
-  root = FetchGitSVNRoot(directory)
-  return VersionInfo(url, root, revision)
+  proc = RunGitCommand(directory, ['log', '-1',
+                                   '--grep=git-svn-id', '--format=%b'])

[tony, 2011/06/14 18:56:31]

The previous code would add -dirty to if there were local commits on top of what
was pulled from the repo.  Did you mean to remove that feature?

[haraken1, 2011/06/15 04:20:41]

Sorry. I reverted the feature. 

+  if proc:
+    output = proc.communicate()[0].strip()
+    if proc.returncode == 0 and output:
+      # Extract both the last changed SVN revision and the SVN url
+      # git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85528 0039d316...
+      match = re.search(r'git-svn-id: (svn://.*)@([0-9]+)', output,

[tony, 2011/06/14 18:56:31]

Does this always work?  What if someone checked out the code from
http://src.chromium.org (the read only repo)?  The regular expression in
tweak_info_plist seems to be different.

[haraken1, 2011/06/15 04:20:41]

I corrected the regular expression into 'git-svn-id:\s*([^@]*)@([0-9]+)', but is
it fine?

+                        re.MULTILINE)

[Denis Lagno, 2011/06/14 17:04:18]

MULTILINE is redundant here

[haraken1, 2011/06/15 04:20:41]

I removed it. 

+      if match:
+        return VersionInfo(match.group(1), 'git', match.group(2))

[Denis Lagno, 2011/06/14 17:04:18]

is it ok to return 'git' as SVN root?

lastchange is called from webkit/build/webkit_version.py and it seems that code
there expects that svn root is prefix of svn url.

[haraken1, 2011/06/15 04:20:41]

Of course, we should return the SVN root if we can get the SVN root through git,
but I do not know the way. The previous code was using "git config --get-regexp
^svn-remote.svn.url$" to extract the SVN root (in FetchGitSVNRoot), but I found
that it does not work actually. In the first place, there seems to be no
information about the SVN root in .git/config. 

For the time being, I used "git-svn" as the SVN root so that the string does not
pass |if| statement at line 54 of webkit_version.py:

if (version_info.url.startswith(version_info.root) and                          
                               
      version_info.url.endswith(version_file_dir)):
   ## not pass here
else
   ## pass here

[Denis Lagno, 2011/06/15 12:25:34]

well, it works for some checkouts (mine for example) but apparently it does not
work universally.

[haraken1, 2011/06/15 16:22:53]

hmmm..., my inclination is to unify the result as much as possible(, although I
know it is impossible to unify it completely). In this sense, I would prefer
"always git-svn" rather than "sometimes the SVN root but sometimes git-svn". If
we use git-svn here, webkit_version.py uses the SVN url as a SVN root. 

+  return None

[Evan Martin, 2011/06/10 17:10:14]

Did you intend to include this change?

[haraken1, 2011/06/10 23:01:00]

Yes. My intention is to extract the revision number in the *same* way on all
platforms so that the version string becomes consistent among all platforms.
Specifically, the way is as follows (this is the way Mac does in
src/chrome/tools/build/mac/tweak_info_plist): 

(1) Try to extract the SVN revision through SVN
(2) If (1) fails, try to extract the SVN revision through Git
(3) If (2) fails, try to extract the Git revision through Git
(4) If (3) fails, give up

[tony, 2011/06/14 18:56:31]

Is it possible to have tweak_info_plist just import this file and call
FetchVersionInfo?

[haraken1, 2011/06/15 04:20:41]

Done.

 
 
 def FetchVersionInfo(default_lastchange, directory=None):
   """
   Returns the last change (in the form of a branch, revision tuple),
   from some appropriate revision control system.
   """
   version_info = (FetchSVNRevision(directory) or
       FetchGitSVNRevision(directory) or FetchGitRevision(directory))
   if not version_info:
@@ skipping 53 matching lines @@
     if out_file:
       WriteIfChanged(out_file, contents)
     else:
       sys.stdout.write(contents)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())