supersize: Add "diff" command

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
@@ skipping 157 matching lines @@
     if self.verbose and len(removed_paths):
       path_delta_desc.append('Removed files:')
       path_delta_desc.extend('  ' + p for p in sorted(removed_paths))
 
     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.old_metadata.iteritems()
-                       if diff.new_metadata[k] == v}
-    old_metadata = {k: v for k, v in diff.old_metadata.iteritems()
-                    if k not in common_metadata}
-    new_metadata = {k: v for k, v in diff.new_metadata.iteritems()
-                    if k not in common_metadata}
+    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()
+                       if k not in common_metadata}
+    after_metadata = {k: v for k, v in diff.after_metadata.iteritems()
+                      if k not in common_metadata}
     metadata_desc = itertools.chain(
         ('Common Metadata:',),
         ('    %s' % line for line in DescribeMetadata(common_metadata)),
         ('Old Metadata:',),
-        ('    %s' % line for line in DescribeMetadata(old_metadata)),
+        ('    %s' % line for line in DescribeMetadata(before_metadata)),
         ('New Metadata:',),
-        ('    %s' % line for line in DescribeMetadata(new_metadata)))
+        ('    %s' % line for line in DescribeMetadata(after_metadata)))
     section_desc = self._DescribeSectionSizes(diff.section_sizes)
     group_desc = self.GenerateLines(diff.symbols)
     return itertools.chain(metadata_desc, section_desc, ('',), group_desc)
 
   def _DescribeSizeInfo(self, size_info):
     metadata_desc = itertools.chain(
         ('Metadata:',),
         ('    %s' % line for line in DescribeMetadata(size_info.metadata)))
     section_desc = self._DescribeSectionSizes(size_info.section_sizes)
     coverage_desc = ()
@@ skipping 76 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')