[NaCl SDK] Update build_sdk.py to display Cr-Commit-Position in README.

BUG=none
R=bradnelson@google.com, bradnelson@chromium.org

Review URL: https://codereview.chromium.org/495423010

Cr-Commit-Position: refs/heads/master@{#292480}

5 files changed, 66 insertions, 17 deletions

diff --git a/native_client_sdk/src/README b/native_client_sdk/src/README
index c44f214..923bb69 100644
--- a/native_client_sdk/src/README
+++ b/native_client_sdk/src/README
@@ -4,6 +4,7 @@ Welcome to the Native Client SDK
 Native Client Tools Bundle
 Version: ${VERSION}
 Chrome Revision: ${CHROME_REVISION}
+Chrome Commit Position: ${CHROME_COMMIT_POSITION}
 Native Client Revision: ${NACL_REVISION}
 Build Date: ${DATE}
 
diff --git a/native_client_sdk/src/build_tools/build_sdk.py b/native_client_sdk/src/build_tools/build_sdk.py
index d4e7f0c..ccc52b7 100755
--- a/native_client_sdk/src/build_tools/build_sdk.py
+++ b/native_client_sdk/src/build_tools/build_sdk.py
@@ -182,6 +182,8 @@ def BuildStepCopyTextFiles(pepperdir, pepper_ver, chrome_revision,
   readme_text = open(os.path.join(SDK_SRC_DIR, 'README')).read()
   readme_text = readme_text.replace('${VERSION}', pepper_ver)
   readme_text = readme_text.replace('${CHROME_REVISION}', chrome_revision)
+  readme_text = readme_text.replace('${CHROME_COMMIT_POSITION}',
+                                    build_version.ChromeCommitPosition())
   readme_text = readme_text.replace('${NACL_REVISION}', nacl_revision)
 
   # Year/Month/Day Hour:Minute:Second
diff --git a/native_client_sdk/src/build_tools/build_version.py b/native_client_sdk/src/build_tools/build_version.py
index ced1a25..91e1381 100644
--- a/native_client_sdk/src/build_tools/build_version.py
+++ b/native_client_sdk/src/build_tools/build_version.py
@@ -29,10 +29,11 @@ def ChromeVersion():
     Chrome version string or trunk + svn rev.
   '''
   info = FetchVersionInfo()
-  if info.url == 'refs/heads/master':
-    return 'trunk.%s' % info.revision
-  else:
-    return ChromeVersionNoTrunk()
+  if info.url == 'git':
+    _, ref, revision = ParseCommitPosition(info)
+    if ref == 'refs/heads/master':
+      return 'trunk.%s' % revision
+  return ChromeVersionNoTrunk()
 
 
 def ChromeVersionNoTrunk():
@@ -60,13 +61,24 @@ def ChromeRevision():
   '''Extract chrome revision from svn.
 
      Now that the Chrome source-of-truth is git, this will return the
-     Cr-Commit-Position instead. fortunately, this value is equal to the SVN
+     Cr-Commit-Position instead. Fortunately, this value is equal to the SVN
      revision if one exists.
 
   Returns:
     The Chrome revision as a string. e.g. "12345"
   '''
-  return FetchVersionInfo().revision
+  version = FetchGitCommitPosition()
+  return ParseCommitPosition(version.revision)[2]
+
+
+def ChromeCommitPosition():
+  '''Return the full git sha and commit position.
+
+  Returns:
+    A value like:
+    0178d4831bd36b5fb9ff477f03dc43b11626a6dc-refs/heads/master@{#292238}
+  '''
+  return FetchGitCommitPosition().revision
 
 
 def NaClRevision():
@@ -81,13 +93,13 @@ def NaClRevision():
 
 def FetchVersionInfo(directory=None,
                      directory_regex_prior_to_src_url='chrome|blink|svn'):
-  """
+  '''
   Returns the last change (in the form of a branch, revision tuple),
   from some appropriate revision control system.
 
   TODO(binji): This is copied from lastchange.py. Remove this function and use
   lastchange.py directly when the dust settles. (see crbug.com/406783)
-  """
+  '''
   svn_url_regex = re.compile(
       r'.*/(' + directory_regex_prior_to_src_url + r')(/.*)')
 
@@ -100,21 +112,47 @@ def FetchVersionInfo(directory=None,
 
 
 def FetchGitCommitPosition(directory=None):
-  """
+  '''
   Return the "commit-position" of the Chromium git repo. This should be
   equivalent to the SVN revision if one eixsts.
 
   This is a copy of the (recently reverted) change in lastchange.py.
   TODO(binji): Move this logic to lastchange.py when the dust settles.
   (see crbug.com/406783)
-  """
+  '''
+  hsh = ''
+  proc = lastchange.RunGitCommand(directory, ['rev-parse', 'HEAD'])
+  if proc:
+    output = proc.communicate()[0].strip()
+    if proc.returncode == 0 and output:
+      hsh = output
+  if not hsh:
+    return None
+  pos = ''
   proc = lastchange.RunGitCommand(directory,
                                   ['show', '-s', '--format=%B', 'HEAD'])
   if proc:
     output = proc.communicate()[0]
     if proc.returncode == 0 and output:
       for line in reversed(output.splitlines()):
-        match = re.search('Cr-Commit-Position: (.*)@{#(\d+)}', line)
-        if match:
-          return lastchange.VersionInfo(match.group(1), match.group(2))
-  return lastchange.VersionInfo(None, None)
+        if line.startswith('Cr-Commit-Position:'):
+          pos = line.rsplit()[-1].strip()
+          break
+  if not pos:
+    return lastchange.VersionInfo('git', hsh)
+  return lastchange.VersionInfo('git', '%s-%s' % (hsh, pos))
+
+
+def ParseCommitPosition(commit_position):
+  '''
+  Parse a Chrome commit position into its components.
+
+  Given a commit position like:
+    0178d4831bd36b5fb9ff477f03dc43b11626a6dc-refs/heads/master@{#292238}
+  Returns:
+    ("0178d4831bd36b5fb9ff477f03dc43b11626a6dc", "refs/heads/master", "292238")
+  '''
+  m = re.match(r'([0-9a-fA-F]+)-([^@]+)@{#(\d+)}', commit_position)
+  if m:
+    return m.groups()
+  return None
diff --git a/native_client_sdk/src/tools/getos.py b/native_client_sdk/src/tools/getos.py
index 62c2b5b..f14e02e 100755
--- a/native_client_sdk/src/tools/getos.py
+++ b/native_client_sdk/src/tools/getos.py
@@ -68,6 +68,7 @@ def GetSDKVersion():
 
   version = None
   revision = None
+  commit_position = None
   for line in open(readme):
     if ':' in line:
       name, value = line.split(':', 1)
@@ -75,8 +76,10 @@ def GetSDKVersion():
         version = value.strip()
       if name == "Chrome Revision":
         revision = value.strip()
+      if name == "Chrome Commit Position":
+        commit_position = value.strip()
 
-  if revision == None or version == None:
+  if revision is None or version is None or commit_position is None:
     raise Error("error parsing SDK README: %s" % readme)
 
   try:
@@ -84,7 +87,7 @@ def GetSDKVersion():
   except ValueError:
     raise Error("error parsing SDK README: %s" % readme)
 
-  return (version, revision)
+  return (version, revision, commit_position)
 
 
 def GetSystemArch(platform):
@@ -204,6 +207,8 @@ def main(args):
       help='Print major version of the NaCl SDK.')
   parser.add_option('--sdk-revision', action='store_true',
       help='Print revision number of the NaCl SDK.')
+  parser.add_option('--sdk-commit-position', action='store_true',
+      help='Print commit position of the NaCl SDK.')
   parser.add_option('--check-version',
       help='Check that the SDK version is at least as great as the '
            'version passed in.')
@@ -229,6 +234,8 @@ def main(args):
     out = GetSDKVersion()[0]
   elif options.sdk_revision:
     out = GetSDKVersion()[1]
+  elif options.sdk_commit_position:
+    out = GetSDKVersion()[2]
   elif options.check_version:
     required_version = ParseVersion(options.check_version)
     version = GetSDKVersion()
diff --git a/native_client_sdk/src/tools/tests/getos_test.py b/native_client_sdk/src/tools/tests/getos_test.py
index 9004bd9..c847fe1 100755
--- a/native_client_sdk/src/tools/tests/getos_test.py
+++ b/native_client_sdk/src/tools/tests/getos_test.py
@@ -117,10 +117,11 @@ class TestGetosWithTempdir(TestCaseExtended):
 
   def testGetSDKVersion(self):
     """correctly parses README to find SDK version."""
-    expected_version = (16, '196')
+    expected_version = (16, '196', 'f00baacabba6e-refs/heads/master@{#100}')
     with open(os.path.join(self.tempdir, 'README'), 'w') as out:
       out.write('Version: %s\n' % expected_version[0])
       out.write('Chrome Revision: %s\n' % expected_version[1])
+      out.write('Chrome Commit Position: %s\n' % expected_version[2])
 
     version = getos.GetSDKVersion()
     self.assertEqual(version, expected_version)