Show detailed difference on unexpected difference.

tools/determinism/compare_build_artifacts.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """Compare the artifacts from two builds."""
 
 import difflib
 import json
 import optparse
 import os
+import re
+import shutil
 import struct
+import subprocess
 import sys
 import time
 
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 
 
 # List of files that are known to be non deterministic. This is a "temporary"
 # workaround to find regression on the deterministic builders.
 #
 # PNaCl general bug: https://crbug.com/429358
@@ skipping 465 matching lines @@
     # else, falls through binary comparison, it must be binary equal too.
 
   file_len = os.stat(first_filepath).st_size
   if file_len != os.stat(second_filepath).st_size:
     return 'different size: %d != %d' % (
         file_len, os.stat(second_filepath).st_size)
 
   return diff_binary(first_filepath, second_filepath, file_len)
 
 
+def get_deps(build_dir, target):
+  """Returns list of object files needed to build target."""
+  NODE_PATTERN = re.compile(r'label="([a-zA-Z0-9_\\/.-]+)"')
+  CHECK_EXTS = ('.o', '.obj')
+
+  # Rename to possibly original directory name if possible.
+  fixed_build_dir = build_dir
+  if build_dir.endswith('.1') or build_dir.endswith('.2'):
+    fixed_build_dir = build_dir[:-2]
+    if os.path.exists(fixed_build_dir):
+      print >> sys.stderr, ('fixed_build_dir %s exists.'
+                            ' will try to use orig dir.' % fixed_build_dir)
+      fixed_build_dir = build_dir
+    else:
+      shutil.move(build_dir, fixed_build_dir)
+
+  try:
+    out = subprocess.check_output(['ninja', '-C', fixed_build_dir,
+                                   '-t', 'graph', target])
+  except subprocess.CalledProcessError as e:
+    print >> sys.stderr, 'error to get graph for %s: %s' % (target, e)
+    return []
+
+  finally:
+    # Rename again if we renamed before.
+    if fixed_build_dir != build_dir:
+      shutil.move(fixed_build_dir, build_dir)
+
+  files = []
+  for line in out.splitlines():
+    matched = NODE_PATTERN.search(line)
+    if matched:
+      path = matched.group(1)
+      if not os.path.splitext(path)[1] in CHECK_EXTS:
+        continue
+      if os.path.isabs(path):
+        print >> sys.stderr, ('not support abs path %s used for target %s'
+                              % (path, target))
+        continue
+      files.append(path)
+  return files
+
+
+def compare_deps(first_dir, second_dir, targets):
+  """Print difference of dependent files."""
+  for target in targets:
+    print 'Checking %s difference:' % target
+    first_deps = get_deps(first_dir, target)
+    second_deps =get_deps(second_dir, target)
+    if set(first_deps) != set(second_deps):
+      # Since we do not thiks this case occur, we do not do anything special
+      # for this case.
+      print 'deps on %s are different: %s' % (
+          target, set(first_deps).symmetric_difference(set(second_deps)))
+      continue
+    for d in first_deps:
+      first_file = os.path.join(first_dir, d)
+      second_file = os.path.join(second_dir, d)
+      compare_files(first_file, second_file)
+
+
 def compare_build_artifacts(first_dir, second_dir, target_platform,
                             recursive=False):
   """Compares the artifacts from two distinct builds."""
   if not os.path.isdir(first_dir):
     print >> sys.stderr, '%s isn\'t a valid directory.' % first_dir
     return 1
   if not os.path.isdir(second_dir):
     print >> sys.stderr, '%s isn\'t a valid directory.' % second_dir
     return 1
 
@@ skipping 46 matching lines @@
   print('Unexpected diffs: %d' % len(unexpected_diffs))
   if unexpected_diffs:
     print('Unexpected files with diffs:\n')
     for u in unexpected_diffs:
       print('  %s' % u)
   if unexpected_equals:
     print('Unexpected files with no diffs:\n')
     for u in unexpected_equals:
       print('  %s' % u)
 
+  if unexpected_diffs:
+    diffs_to_investigate = set(unexpected_diffs).difference(
+        set(missing_files))
+    compare_deps(first_dir, second_dir, diffs_to_investigate)
+
   return int(bool(unexpected_diffs))
 
 
 def main():
   parser = optparse.OptionParser(usage='%prog [options]')
   parser.add_option(
       '-f', '--first-build-dir', help='The first build directory.')
   parser.add_option(
       '-s', '--second-build-dir', help='The second build directory.')
   parser.add_option('-r', '--recursive', action='store_true', default=False,
@@ skipping 13 matching lines @@
     parser.error('--target-platform is required')
 
   return compare_build_artifacts(os.path.abspath(options.first_build_dir),
                                  os.path.abspath(options.second_build_dir),
                                  options.target_platform,
                                  options.recursive)
 
 
 if __name__ == '__main__':
   sys.exit(main())