supersize: Fix diff logic for changed vs unchanged of groups

tools/binary_size/libsupersize/describe.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.
 """Methods for converting model objects to human-readable formats."""
 
 import datetime
 import itertools
 import time
 
 import models
 
 
+_DIFF_PREFIX_BY_STATUS = ['= ', '~ ', '+ ', '- ']
+
+
 def _PrettySize(size):
   # Arbitrarily chosen cut-off.
   if abs(size) < 2000:
     return '%d bytes' % size
   # Always show 3 digits.
   size /= 1024.0
   if abs(size) < 10:
     return '%.2fkb' % size
   elif abs(size) < 100:
     return '%.1fkb' % size
@@ skipping 12 matching lines @@
   if pss > 10:
     return str(int(pss))
   ret = str(round(pss, 1))
   if ret.endswith('.0'):
     ret = ret[:-2]
     if ret == '0' and pss:
       ret = '~0'
   return ret
 
 
-def _DiffPrefix(diff, sym):
-  if diff.IsAdded(sym):
-    return '+ '
-  if diff.IsRemoved(sym):
-    return '- '
-  if sym.size:
-    return '~ '
-  return '= '
-
-
 def _Divide(a, b):
   return float(a) / b if b else 0
 
 
 class Describer(object):
   def __init__(self, verbose=False, recursive=False):
     self.verbose = verbose
     self.recursive = recursive
 
   def _DescribeSectionSizes(self, section_sizes):
@@ skipping 67 matching lines @@
     for index, s in enumerate(group):
       if group.IsBss() or not s.IsBss():
         running_total += s.pss
         running_percent = _Divide(running_total, total)
       for l in self._DescribeSymbol(s, single_line=all_groups):
         if l[:4].isspace():
           indent_size = 8 + len(indent_prefix) + len(diff_prefix)
           yield '{} {}'.format(' ' * indent_size, l)
         else:
           if is_diff:
-            diff_prefix = _DiffPrefix(group, s)
+            diff_prefix = _DIFF_PREFIX_BY_STATUS[group.DiffStatus(s)]
           yield '{}{}{:<4} {:>8} {:7} {}'.format(
               indent_prefix, diff_prefix, str(index) + ')',
               _FormatPss(running_total), '({:.1%})'.format(running_percent), l)
 
       if self.recursive and s.IsGroup():
         for l in self._DescribeSymbolGroupChildren(s, indent=indent + 1):
           yield l
 
   def _DescribeSymbolGroup(self, group):
     total_size = group.pss
@@ skipping 22 matching lines @@
             _PrettySize(int(data_size)), _PrettySize(int(bss_size)),
             _PrettySize(int(total_size))),
         'Number of unique paths: {}'.format(len(unique_paths)),
         '',
         'Index, Running Total, Section@Address, PSS',
         '-' * 60
     ]
     children_desc = self._DescribeSymbolGroupChildren(group)
     return itertools.chain(header_desc, children_desc)
 
+  def _DescribeDiffObjectPaths(self, diff):
+    paths_by_status = [set(), set(), set(), set()]
+    def helper(group):
+      for s in group:
+        if s.IsGroup():
+          helper(s)
+        else:
+          status = group.DiffStatus(s)
+          paths_by_status[status].add(s.source_path or s.object_path)
+    helper(diff)
+    # Show only paths that have no changed symbols (pure adds / removes).
+    unchanged, changed, added, removed = paths_by_status
+    added.difference_update(unchanged)
+    added.difference_update(changed)
+    removed.difference_update(unchanged)
+    removed.difference_update(changed)
+    yield '{} paths added, {} removed, {} changed'.format(
+        len(added), len(removed), len(changed))
+
+    if self.verbose and len(added):
+      yield 'Added files:'
+      for p in sorted(added):
+        yield '  ' + p
+    if self.verbose and len(removed):
+      yield 'Removed files:'
+      for p in sorted(removed):
+        yield '  ' + p
+    if self.verbose and len(changed):
+      yield 'Changed files:'
+      for p in sorted(changed):
+        yield '  ' + p
+
   def _DescribeSymbolDiff(self, diff):
     header_template = ('{} symbols added (+), {} changed (~), {} removed (-), '
                        '{} unchanged ({})')
     unchanged_msg = '=' if self.verbose else 'not shown'
     symbol_delta_desc = [header_template.format(
         diff.added_count, diff.changed_count, diff.removed_count,
         diff.unchanged_count, unchanged_msg)]
-
-    similar_paths = set()
-    added_paths = set()
-    removed_paths = set()
-    for s in diff:
-      if diff.IsAdded(s):
-        added_paths.add(s.object_path)
-      elif diff.IsRemoved(s):
-        removed_paths.add(s.object_path)
-      else:
-        similar_paths.add(s.object_path)
-    added_paths.difference_update(similar_paths)
-    removed_paths.difference_update(similar_paths)
-    path_delta_desc = ['{} object files added, {} removed'.format(
-        len(added_paths), len(removed_paths))]
-    if self.verbose and len(added_paths):
-      path_delta_desc.append('Added files:')
-      path_delta_desc.extend('  ' + p for p in sorted(added_paths))
-    if self.verbose and len(removed_paths):
-      path_delta_desc.append('Removed files:')
-      path_delta_desc.extend('  ' + p for p in sorted(removed_paths))
+    path_delta_desc = self._DescribeDiffObjectPaths(diff)
 
     diff = diff if self.verbose else diff.WhereNotUnchanged()
     group_desc = self._DescribeSymbolGroup(diff)
     return itertools.chain(symbol_delta_desc, path_delta_desc, ('',),
                            group_desc)
 
   def _DescribeSizeInfoDiff(self, diff):
     common_metadata = {k: v for k, v in diff.before_metadata.iteritems()
                        if diff.after_metadata[k] == v}
     before_metadata = {k: v for k, v in diff.before_metadata.iteritems()
@@ skipping 113 matching lines @@
 
 def GenerateLines(obj, verbose=False, recursive=False):
   """Returns an iterable of lines (without \n) that describes |obj|."""
   return Describer(verbose=verbose, recursive=recursive).GenerateLines(obj)
 
 
 def WriteLines(lines, func):
   for l in lines:
     func(l)
     func('\n')