Start work on GN build for content/common

build/gypi_to_gn.py

 # 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.
 
 """Converts a given gypi file to a python scope and writes the result to stdout.
 
 It is assumed that the file contains a toplevel dictionary, and this script
 will return that dictionary as a GN "scope" (see example below). This script
 does not know anything about GYP and it will not expand variables or execute
-conditions (it will check for the presence of a "conditions" value in the
-dictionary and will abort if it is present). It also does not support nested
-dictionaries.
+conditions.
+
+It will strip conditions blocks.
+
+A variables block at the top level will be flattened so that the variables
+appear in the root dictionary. This way they can be returned to the GN code.
 
 Say your_file.gypi looked like this:
   {
      'sources': [ 'a.cc', 'b.cc' ],
      'defines': [ 'ENABLE_DOOM_MELON' ],
   }
 
 You would call it like this:
   gypi_values = exec_script("//build/gypi_to_gn.py",
                             [ rebase_path("your_file.gypi") ],
@@ skipping 51 matching lines @@
   file_string = open(path).read()
   try:
     file_data = eval(file_string, {'__builtins__': None}, None)
   except SyntaxError, e:
     e.filename = path
     raise
   except Exception, e:
     raise Exception("Unexpected error while reading %s: %s" % (path, str(e)))
 
   assert isinstance(file_data, dict), "%s does not eval to a dictionary" % path
-  assert 'conditions' not in file_data, \
-      "The file %s has conditions in it, these aren't supported." % path
+
+  # Strip any conditions.
+  if 'conditions' in file_data:
+    del file_data['conditions']
+  if 'target_conditions' in file_data:
+    del file_data['target_conditions']
+
+  # Flatten any varaiables to the top level.
+  if 'variables' in file_data:
+    file_data.update(file_data['variables'])
+    del file_data['variables']
 
   # If the contents of the root is a dictionary with exactly one kee
   # "variables", promote the contents of that to the top level. Some .gypi
   # files contain this and some don't depending on how they expect to be
   # embedded in a .gyp file. We don't actually care either way so collapse it
   # away.
   if len(file_data) == 1 and 'variables' in file_data:
     return file_data['variables']
 
   return file_data
@@ skipping 44 matching lines @@
       data = ReplaceSubstrings(data, split[0], split[1])
 
   print gn_helpers.ToGNString(data)
 
 if __name__ == '__main__':
   try:
     main()
   except Exception, e:
     print str(e)
     sys.exit(1)