remote_run: use /b as base directory for temporary files when available

scripts/common/chromium_utils.py

 # Copyright (c) 2012 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.
 
 """ Set of basic operations/utilities that are used by the build. """
 
 from contextlib import contextmanager
 import ast
 import base64
 import cStringIO
@@ skipping 794 matching lines @@
   cur_dir = start_dir
   found_path = os.path.join(cur_dir, desired_path)
   while not os.path.exists(found_path):
     last_dir = cur_dir
     cur_dir = os.path.dirname(cur_dir)
     if last_dir == cur_dir:
       raise PathNotFound('Unable to find %s above %s' %
                          (desired_path, start_dir))
     found_path = os.path.join(cur_dir, desired_path)
   # Strip the entire original desired path from the end of the one found
-  # and remove a trailing path separator, if present.
+  # and remove a trailing path separator, if present (unless it's
+  # filesystem/drive root).
   found_path = found_path[:len(found_path) - len(desired_path)]
-  if found_path.endswith(os.sep):
+  if found_path.endswith(os.sep) and os.path.dirname(found_path) != found_path:

[estaab, 2016/06/14 16:57:36]

This changes the behavior of this function so if someone was depending on it to
return the root when the path wasn't found it will break now, so perhaps watch
for breakage after this goes in.

[Paweł Hajdan Jr., 2016/06/15 07:59:10]

Yup. FWIW, Windows might also be funny - I'll definitely watch out. Landing this
early my local time.

     found_path = found_path[:len(found_path) - 1]
   return found_path
 
 
 def FindUpward(start_dir, *desired_list):
   """Returns a path to the desired directory or file, searching upward.
 
   Searches within start_dir and within all its parents looking for the desired
   directory or file, which may be given in one or more path components. Returns
   the full path to the desired object, or raises PathNotFound if it wasn't
@@ skipping 1191 matching lines @@
     return False
   # Matches e.g. "cl_x86 = path/to/clang-cl.exe"
   clang_cl_re = re.compile(
       r'^cl_x\d\d\s+\=\s+(?P<compiler_path>[^ ]+)\s.*$',
       re.VERBOSE)
   for line in open(build_file):
     m = clang_cl_re.match(line)
     if m:
       return 'clang' in m.group('compiler_path')
   return False