Improve script to find user actions.

tools/metrics/actions/extract_actions.py

Index: tools/metrics/actions/extract_actions.py
diff --git a/tools/metrics/actions/extract_actions.py b/tools/metrics/actions/extract_actions.py
index c7f550f6981f20f64ba124321b25639e6387a2e0..9231c39bc9c40898333258e3311ae802d9a3987e 100755
--- a/tools/metrics/actions/extract_actions.py
+++ b/tools/metrics/actions/extract_actions.py
@@ -14,7 +14,6 @@ there are many possible actions.
 
 See also:
   base/metrics/user_metrics.h
-  http://wiki.corp.google.com/twiki/bin/view/Main/ChromeUserExperienceMetrics
 
 After extracting all actions, the content will go through a pretty print
 function to make sure it's well formatted. If the file content needs to be
@@ -42,6 +41,10 @@ sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
 import diff_util
 import pretty_print_xml
 
+USER_METRICS_ACTION_RE = re.compile(r'UserMetricsAction\(\s*(.+?)\)')

[Ilya Sherman, 2015/01/09 22:25:43]

nit: I think it might be worth using the verbose regex format for this guy, and
document the individual pieces, since it's a little bit complex.

[Ilya Sherman, 2015/01/09 22:25:44]

It looks like you've changed the regexes quite a bit.  Why did you drop the
[^a-zA-Z] check, for example?  Also, are you sure that ".+" is correct?  I think
that would allow the match to go past any parens, e.g. to match 
"""UserMetricsAction("I'm an action!"), "I'm some other parameter.");"""

[Alexei Svitkine (slow), 2015/01/12 19:58:24]

I've re-added it now.
I added a test case for your example and it works correctly.

[Alexei Svitkine (slow), 2015/01/12 19:58:24]

Done.

+COMPUTED_ACTION_RE = re.compile(r'RecordComputedAction')
+QUOTED_STRING_RE = re.compile(r'\"(.+?)\"')
+
 # Files that are known to use content::RecordComputedAction(), which means
 # they require special handling code in this script.
 # To add a new file, add it to this list and add the appropriate logic to
@@ -410,6 +413,21 @@ def AddExtensionActions(actions):
   # Actions sent by 'Ok Google' Hotwording.
   actions.add('Hotword.HotwordTrigger')
 
+def FindActionNames(contents, pos):
+  """Finds actions from the first UserMetricsAction() call in |contents|.
+
+  Arguments:
+    contents: string to search through
+    pos: position in |contents| to start the search from
+
+  Returns:
+    The list action names (strings) that was found.

[Ilya Sherman, 2015/01/09 22:25:43]

Please update this -- it looks like there are two values returned.

[Alexei Svitkine (slow), 2015/01/12 19:58:24]

Done.

+  """
+  match = USER_METRICS_ACTION_RE.search(contents, pos=pos)
+  if not match:
+    return None, None
+  return QUOTED_STRING_RE.findall(match.group(1)), match.end()
+
 def GrepForActions(path, actions):
   """Grep a source file for calls to UserMetrics functions.
 
@@ -419,22 +437,19 @@ def GrepForActions(path, actions):
   """
   global number_of_files_total
   number_of_files_total = number_of_files_total + 1
-  # we look for the UserMetricsAction structure constructor
-  # this should be on one line
-  action_re = re.compile(r'[^a-zA-Z]UserMetricsAction\("([^"]*)')
-  malformed_action_re = re.compile(r'[^a-zA-Z]UserMetricsAction\([^"]')
-  computed_action_re = re.compile(r'RecordComputedAction')
+
+  contents = open(path).read()
+  pos = 0
+  while True:
+    action_names, pos = FindActionNames(contents, pos)
+    if not action_names:
+      break
+    actions.update(action_names)
+
   line_number = 0
   for line in open(path):
     line_number = line_number + 1
-    match = action_re.search(line)
-    if match:  # Plain call to RecordAction
-      actions.add(match.group(1))
-    elif malformed_action_re.search(line):
-      # Warn if this line is using RecordAction incorrectly.
-      print >>sys.stderr, ('WARNING: %s has malformed call to RecordAction'
-                           ' at %d' % (path, line_number))
-    elif computed_action_re.search(line):
+    if COMPUTED_ACTION_RE.search(line):
       # Warn if this file shouldn't be calling RecordComputedAction.
       if os.path.basename(path) not in KNOWN_COMPUTED_USERS:
         print >>sys.stderr, ('WARNING: %s has RecordComputedAction at %d' %