webkit: expose webkit branch and revision number in about pages

- Change lastchange.py to work in other directories and to
  provide SVN URL.
- Use lastchange.py in place where we generate WebKit versioning
  info.
- Include branch@revision string in glue API.

BUG=41264
TEST=compiles

Review URL: http://codereview.chromium.org/6354014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72245 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 108 insertions, 31 deletions

diff --git a/build/util/lastchange.py b/build/util/lastchange.py
index 1846bab..a91a520 100755
--- a/build/util/lastchange.py
+++ b/build/util/lastchange.py
@@ -9,46 +9,71 @@ lastchange.py -- Chromium revision fetching utility.
 
 import optparse
 import os
-import re
 import subprocess
 import sys
 
+class VersionInfo(object):
+  def __init__(self, url, root, revision):
+    self.url = url
+    self.root = root
+    self.revision = revision
 
-def FetchSVNRevision(command):
+
+def FetchSVNRevision(command, directory):
   """
-  Fetch the Subversion revision for the local tree.
+  Fetch the Subversion branch and revision for the a given directory
+  by running the given command (e.g. "svn info").
 
   Errors are swallowed.
+
+  Returns:
+    a VersionInfo object or None on error.
   """
   try:
     proc = subprocess.Popen(command,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE,
+                            cwd=directory,
                             shell=(sys.platform=='win32'))
   except OSError:
     # command is apparently either not installed or not executable.
     return None
-  if proc:
-    svn_re = re.compile('^Revision:\s+(\d+)', re.M)
-    match = svn_re.search(proc.stdout.read())
-    if match:
-      return match.group(1)
-  return None
+  if not proc:
+    return None
+
+  attrs = {}
+  for line in proc.stdout:
+    line = line.strip()
+    if not line:
+      continue
+    key, val = line.split(': ', 1)
+    attrs[key] = val
+
+  try:
+    url = attrs['URL']
+    root = attrs['Repository Root']
+    revision = attrs['Revision']
+  except KeyError:
+    return None
+
+  return VersionInfo(url, root, revision)
 
 
-def FetchChange(default_lastchange):
+def FetchVersionInfo(default_lastchange, directory=None):
   """
-  Returns the last change, from some appropriate revision control system.
+  Returns the last change (in the form of a branch, revision tuple),
+  from some appropriate revision control system.
   """
-  change = FetchSVNRevision(['svn', 'info'])
-  if not change and sys.platform in ('linux2',):
-    change = FetchSVNRevision(['git', 'svn', 'info'])
-  if not change:
+  version_info = FetchSVNRevision(['svn', 'info'], directory)
+  if not version_info and sys.platform in ('linux2',):
+    version_info = FetchSVNRevision(['git', 'svn', 'info'], directory)
+  if not version_info:
     if default_lastchange and os.path.exists(default_lastchange):
-      change = open(default_lastchange, 'r').read().strip()
+      revision = open(default_lastchange, 'r').read().strip()
+      version_info = VersionInfo(None, None, revision)
     else:
-      change = '0'
-  return change
+      version_info = VersionInfo('', '', '0')
+  return version_info
 
 
 def WriteIfChanged(file_name, contents):
@@ -90,12 +115,12 @@ def main(argv=None):
     parser.print_help()
     sys.exit(2)
 
-  change = FetchChange(opts.default_lastchange)
+  version_info = FetchVersionInfo(opts.default_lastchange)
 
   if opts.revision_only:
-    print change
+    print version_info.revision
   else:
-    contents = "LASTCHANGE=%s\n" % change
+    contents = "LASTCHANGE=%s\n" % version_info.revision
     if out_file:
       WriteIfChanged(out_file, contents)
     else:
diff --git a/webkit/build/webkit_version.py b/webkit/build/webkit_version.py
index 9f8fbab..5811072 100755
--- a/webkit/build/webkit_version.py
+++ b/webkit/build/webkit_version.py
@@ -12,6 +12,9 @@ import os
 import re
 import sys
 
+sys.path.insert(0, '../../build/util')
+import lastchange
+
 def ReadVersionFile(fname):
   '''Reads the Webkit Version.xcconfig file looking for MAJOR_VERSION and
      MINOR_VERSION.  This function doesn't attempt to support the full syntax
@@ -37,11 +40,43 @@ def ReadVersionFile(fname):
   assert(major >= 0 and minor >= 0)
   return (major, minor)
 
-def EmitVersionHeader(version_file, output_dir):
+def GetWebKitRevision(webkit_dir, version_file):
+  """Get the WebKit revision, in the form 'trunk@1234'."""
+
+  # "svn info" tells us what we want, but third_party/WebKit does *not*
+  # point at the upstream repo.  So instead we run svn info on the directory
+  # containing the versioning file (which is some subdirectory of WebKit),
+  # then strip that path back off of the resulting URL.
+  version_file_dir = os.path.dirname(version_file)
+  version_info = lastchange.FetchVersionInfo(
+      default_lastchange=None,
+      directory=os.path.join(webkit_dir, version_file_dir))
+
+  # Now compute the real WebKit URL by stripping off the version file
+  # directory from the URL we get out of version_info.
+  # Further, we want to strip off the "http://svn..." from the left.
+  # This is the root URL from the repository.
+  assert version_info.url.startswith(version_info.root)
+  assert version_info.url.endswith(version_file_dir)
+  webkit_url = version_info.url[len(version_info.root):-len(version_file_dir)]
+  webkit_url = webkit_url.strip('/')
+
+  return "%s@%s" % (webkit_url, version_info.revision)
+
+
+def EmitVersionHeader(webkit_dir, version_file, output_dir):
   '''Given webkit's version file, emit a header file that we can use from
   within webkit_glue.cc.
   '''
-  (major, minor) = ReadVersionFile(version_file)
+
+  # See .gypi file for discussion of this workaround for the version file.
+  assert version_file[0] == '/'
+  version_file = version_file[1:]
+
+  major, minor = ReadVersionFile(os.path.join(webkit_dir, version_file))
+
+  webkit_revision = GetWebKitRevision(webkit_dir, version_file)
+
   fname = os.path.join(output_dir, "webkit_version.h")
   f = open(fname, 'wb')
   template = """// webkit_version.h
@@ -49,12 +84,13 @@ def EmitVersionHeader(version_file, output_dir):
 
 #define WEBKIT_VERSION_MAJOR %d
 #define WEBKIT_VERSION_MINOR %d
-""" % (version_file, major, minor)
+#define WEBKIT_SVN_REVISION "%s"
+""" % (version_file, major, minor, webkit_revision)
   f.write(template)
   f.close()
 
 def main():
-  EmitVersionHeader(sys.argv[1], sys.argv[2])
+  EmitVersionHeader(*sys.argv[1:])
 
 
 if __name__ == "__main__":
diff --git a/webkit/glue/user_agent.cc b/webkit/glue/user_agent.cc
index 4867c27..afd1c83 100644
--- a/webkit/glue/user_agent.cc
+++ b/webkit/glue/user_agent.cc
@@ -22,8 +22,14 @@ namespace webkit_glue {
 std::string GetProductVersion();
 
 std::string GetWebKitVersion() {
-  return base::StringPrintf("%d.%d", WEBKIT_VERSION_MAJOR,
-                                     WEBKIT_VERSION_MINOR);
+  return base::StringPrintf("%d.%d (%s)",
+                            WEBKIT_VERSION_MAJOR,
+                            WEBKIT_VERSION_MINOR,
+                            WEBKIT_SVN_REVISION);
+}
+
+std::string GetWebKitRevision() {
+  return WEBKIT_SVN_REVISION;
 }
 
 std::string BuildOSCpuInfo() {
diff --git a/webkit/glue/user_agent.h b/webkit/glue/user_agent.h
index 3d1f788..62c8324 100644
--- a/webkit/glue/user_agent.h
+++ b/webkit/glue/user_agent.h
@@ -19,7 +19,7 @@ void BuildUserAgent(bool mimic_windows, std::string* result);
 // Builds a User-agent compatible string that describes the OS and CPU type.
 std::string BuildOSCpuInfo();
 
-// Returns the WebKit version (major.minor).
+// Returns the WebKit version, in the form "major.minor (branch@revision)".
 std::string GetWebKitVersion();
 
 }  // namespace webkit_glue
diff --git a/webkit/glue/webkit_glue.gypi b/webkit/glue/webkit_glue.gypi
index b6a8c6a..eec99bf 100644
--- a/webkit/glue/webkit_glue.gypi
+++ b/webkit/glue/webkit_glue.gypi
@@ -120,13 +120,23 @@
         {
           'action_name': 'webkit_version',
           'inputs': [
-            '../build/webkit_version.py',
-            '<(webkit_src_dir)/Source/WebCore/Configurations/Version.xcconfig',
+            '<(script)',
+            '<(webkit_src_dir)<(version_file)',
+            '../../build/util/lastchange.py',  # Used by the script.
           ],
           'outputs': [
             '<(INTERMEDIATE_DIR)/webkit_version.h',
           ],
-          'action': ['python', '<@(_inputs)', '<(INTERMEDIATE_DIR)'],
+          'action': ['python', '<(script)', '<(webkit_src_dir)',
+                     '<(version_file)', '<(INTERMEDIATE_DIR)'],
+          'variables': {
+            'script': '../build/webkit_version.py',
+            # version_file is a relative path from |webkit_src_dir| to
+            # the version file.  But gyp will eat the variable unless
+            # it looks like an absolute path, so write it like one and
+            # then use it carefully above.
+            'version_file': '/Source/WebCore/Configurations/Version.xcconfig',
+          },
         },
       ],
       'include_dirs': [