supersize: Fix name normalization of top-level lambdas

tools/binary_size/libsupersize/function_signature.py

 # Copyright 2017 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.
 
 """Logic for parsing a C/C++ function signature."""
 
 
 def _FindParameterListParen(name):
   """Finds index of the "(" that denotes the start of a paremeter list."""
   # This loops from left-to-right, but the only reason (I think) that this
@@ skipping 25 matching lines @@
             template_balance_count += 1
 
       paren_balance_count += (
           name.count('(', start_idx, idx) - name.count(')', start_idx, idx))
       if template_balance_count == 0 and paren_balance_count == 0:
         # Special case: skip "(anonymous namespace)".
         if -1 != name.find('(anonymous namespace)', idx, idx + 21):
           start_idx = idx + 21
           continue
         # Special case: skip "decltype (...)"
-        if name[idx - 1] != ' ':
+        # Special case: skip "{lambda(PaintOp*)#63}"
+        if name[idx - 1] != ' ' and name[idx - 7:idx] != '{lambda':
           return idx
       start_idx = idx + 1
       paren_balance_count += 1
 
 
 def _FindLastCharOutsideOfBrackets(name, target_char, prev_idx=None):
   """Returns the last index of |target_char| that is not within ()s nor <>s."""
   paren_balance_count = 0
   template_balance_count = 0
   while True:
@@ skipping 21 matching lines @@
     space_idx = _FindLastCharOutsideOfBrackets(name, ' ', space_idx)
     # Special case: "operator new", and "operator<< <template>".
     if -1 == space_idx or (
         -1 == name.find('operator', space_idx - 8, space_idx) and
         -1 == name.find('operator<<', space_idx - 10, space_idx)):
       break
     space_idx -= 8
   return space_idx
 
 
+def _NormalizeTopLevelLambda(name, space_idx, left_paren_idx):
+  # cc::{lambda(PaintOp*)#63}::_FUN() -> cc:{lambda#63}()
+  paren_idx = name.index('(', space_idx + 1)
+  hash_idx = name.rindex('#', paren_idx)
+  return (name[:paren_idx] + name[hash_idx:left_paren_idx - 6] +
+          name[left_paren_idx:])
+
+
 def Parse(name):
   """Extracts a function name from a function signature.
 
   See unit tests for example signatures.
 
   Returns:
     A tuple of (name_without_return_type, name_without_return_type_and_params).
   """
   left_paren_idx = _FindParameterListParen(name)
 
+  full_name = name
   if left_paren_idx > 0:
     right_paren_idx = name.rindex(')')
     assert right_paren_idx > left_paren_idx
     space_idx = _FindReturnValueSpace(name, left_paren_idx)
-    return (name[space_idx + 1:],
-            name[space_idx + 1:left_paren_idx] + name[right_paren_idx + 1:])
-  return name, name
+    name_without_attrib = name[space_idx + 1:left_paren_idx]
+    # Special case for top-level lamdas.
+    if name_without_attrib.endswith('}::_FUN'):
+      # Don't use name_without_attrib in here since prior _idx will be off if
+      # there was a return value.
+      name = _NormalizeTopLevelLambda(name, space_idx, left_paren_idx)
+      return Parse(name)
+
+    full_name = name[space_idx + 1:]
+    name = name_without_attrib + name[right_paren_idx + 1:]
+
+  return full_name, name