Make the ninja generator handle symlinked paths correctly.

pylib/gyp/common.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from __future__ import with_statement
 
 import collections
 import errno
 import filecmp
 import os.path
@@ skipping 113 matching lines @@
   # "Qualified" means the file that a target was defined in and the target
   # name, separated by a colon, suffixed by a # and the toolset name:
   # /path/to/file.gyp:target_name#toolset
   fully_qualified = build_file + ':' + target
   if toolset:
     fully_qualified = fully_qualified + '#' + toolset
   return fully_qualified
 
 
 @memoize
-def RelativePath(path, relative_to):
+def RelativePath(path, relative_to, follow_path_symlink=True):

[scottmg, 2015/09/24 21:30:51]

could you add some explanation for this arg here? It's not immediately obvious
what it means to me. (something like what's in the head of the test I guess)

[lindleyf, 2015/09/24 21:47:14]

I've added a comment here and at the point of use. Let me know if it's clear.

   # Assuming both |path| and |relative_to| are relative to the current
   # directory, returns a relative path that identifies path relative to
   # relative_to.
 
   # Convert to normalized (and therefore absolute paths).
-  path = os.path.realpath(path)
+  if follow_path_symlink:
+    path = os.path.realpath(path)
+  else:
+    path = os.path.abspath(path)
   relative_to = os.path.realpath(relative_to)
 
   # On Windows, we can't create a relative path to a different drive, so just
   # use the absolute path.
   if sys.platform == 'win32':
     if (os.path.splitdrive(path)[0].lower() !=
         os.path.splitdrive(relative_to)[0].lower()):
       return path
 
   # Split the paths into components.
@@ skipping 439 matching lines @@
 def CrossCompileRequested():
   # TODO: figure out how to not build extra host objects in the
   # non-cross-compile case when this is enabled, and enable unconditionally.
   return (os.environ.get('GYP_CROSSCOMPILE') or
           os.environ.get('AR_host') or
           os.environ.get('CC_host') or
           os.environ.get('CXX_host') or
           os.environ.get('AR_target') or
           os.environ.get('CC_target') or
           os.environ.get('CXX_target'))