Initial code generation for features.

tools/json_schema_compiler/features_compiler.py

+#!/usr/bin/env python
+# 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.
+"""Generator for C++ features from json files.
+
+Usage example:
+  features_compiler.py --destdir gen --root /home/Work/src _permissions.json
+"""
+
+import optparse
+import os
+import sys
+
+import json_schema
+from schema_loader import SchemaLoader
+from features_cc_generator import CCGenerator
+from features_h_generator import HGenerator
+from model import ComplexFeature, CreateFeature
+
+
+def _GenerateSchema(filename, root, destdir):
+  """Generates C++ features files from the json file |filename|.
+  """
+  # Load in the feature permissions from the JSON file.
+  schema = os.path.normpath(filename)
+  schema_loader = SchemaLoader(os.path.dirname(os.path.relpath(schema, root)))
+  schema_filename, _ = os.path.splitext(schema)
+  feature_defs = schema_loader.LoadSchema(schema)
+
+  # Generate a list of the features defined and a list of their models.
+  feature_list = []
+  for feature_def, feature in feature_defs.iteritems():
+    feature_list.append(CreateFeature(feature_def, feature))
+
+  source_file_dir, source_file_filename = os.path.split(schema)
+  relpath = os.path.relpath(os.path.normpath(source_file_dir), root)
+  full_path = os.path.join(relpath, schema)
+
+  generators = [
+      ('%s.cc' % schema_filename, CCGenerator()),
+      ('%s.h' % schema_filename, HGenerator())
+  ]
+
+  # Generate and output the code for all features.
+  output_code = []
+  for filename, generator in generators:
+    code = generator.Generate(feature_list, full_path).Render()
+    if destdir:
+      with open(os.path.join(destdir, relpath, filename), 'w') as f:
+        f.write(code)
+    output_code += [filename, '', code, '']
+
+  return '\n'.join(output_code)
+
+
+if __name__ == '__main__':
+  parser = optparse.OptionParser(
+      description='Generates a C++ features model from JSON schema',
+      usage='usage: %prog [option]... schema')
+  parser.add_option('-r', '--root', default='.',
+      help='logical include root directory. Path to schema files from '
+           'specified dir will be the include path.')
+  parser.add_option('-d', '--destdir',
+      help='root directory to output generated files.')

[not at google - send to devlin, 2013/09/17 18:26:19]

this also need a C++ namespace option similar to how the JSON schema compiler
works, so that we can put these in the extensions:: namespace.

[dhnishi (use Chromium), 2013/09/18 18:32:45]

Done.

+  (opts, filenames) = parser.parse_args()
+
+  # Only one file is currently specified.
+  if len(filenames) != 1:
+    raise ValueError('One (and only one) file is required (for now).')
+
+  result = _GenerateSchema(filenames[0], opts.root, opts.destdir)
+  if not opts.destdir:
+    print result