Avoid computing patch_root in get_files_affected_by_patch.

recipe_modules/gclient/api.py

 # Copyright 2013 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.
 
 from recipe_engine import recipe_api
 
 
 class RevisionResolver(object):
   """Resolves the revision based on build properties."""
 
@@ skipping 358 matching lines @@
     """Updates config revision corresponding to patch_project.
 
     Useful for bot_update only, as this is the only consumer of gclient's config
     revision map. This doesn't overwrite the revision if it was already set.
     """
     assert patch_project is None or isinstance(patch_project, basestring)
     cfg = gclient_config or self.c
     path, revision = cfg.patch_projects.get(patch_project, (None, None))
     if path and revision and path not in cfg.revisions:
       cfg.revisions[path] = revision
+
+  def get_files_affected_by_patch(self, patch_project, gclient_config=None):
+    """Returns list of paths to files affected by the patch."""
+    patch_root = self.calculate_patch_root(patch_project, gclient_config)

[Michael Achenbach, 2016/04/29 14:11:53]

Maybe patch_root should be a parameter to this method instead of patch_project,
gclient_config. Then the patch_root should be calculated elsewhere, using the
method from gclient.

[tandrii(chromium), 2016/04/29 15:09:41]

Good idea. Will do that.

+    step_result = self.m.git('diff', '--cached', '--name-only',
+                             cwd=self.m.path['root'].join(patch_root),
+                             name='git diff to analyze patch',
+                             stdout=self.m.raw_io.output(),
+                             step_test_data=lambda:
+                               self.m.raw_io.test_api.stream_output('foo.cc'))
+    paths = step_result.stdout.split()
+    if patch_root:
+      paths = [self.m.path.join(patch_root, path) for path in paths]
+    if self.m.platform.is_win:
+      # Looks like "analyze" wants POSIX slashes even on Windows (since git
+      # uses that format even on Windows).
+      paths = [path.replace('\\', '/') for path in paths]
+
+    step_result.presentation.logs['files'] = paths
+    return paths