Generalize patch_project to patch root conversion.

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 318 matching lines @@
           for (path, dir, files) in os.walk(build_path):
             for cur_file in files:
               if cur_file.endswith('index.lock'):
                 path_to_file = os.path.join(path, cur_file)
                 print 'deleting %s' % path_to_file
                 os.remove(path_to_file)
       """,
       args=[self.m.path['slave_build']],
       infra_step=True,
     )
+
+  def calculate_patch_root(self, patch_project, gclient_config=None):
+    """Returns path where a patch should be applied to based patch_project.
+
+    Maps "patch_project" to a path of directories relative to checkout's root,
+    which describe where to place the patch.
+
+    For now, considers only first solution (c.solutions[0]), but in theory can
+    be extended to all of them.
+
+    See patch_projects solution config property.
+
+    Returns:
+      Relative path, including solution's root.
+      If patch_project is not given or not recognized, it'll be just first
+      solution root.
+    """
+    cfg = gclient_config or self.c
+    root, _ = cfg.solutions[0].patch_projects.get(patch_project, ('', ''))

[Michael Achenbach, 2016/04/25 09:32:42]

solutions[0] goes away when making the dict global.

[tandrii(chromium), 2016/04/25 11:39:50]

Done.

+    if root:
+      # Note, that c.solutions[i].patch_projects contains patch roots as
+      # /-separated path, which are roots of the respective project repos.
+      return self.m.path.join(*root.split('/'))
+    # Default case - assume patch is for first solution.
+    return cfg.solutions[0].name