Code generation for extensions api

tools/json_schema_compiler/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++ structs from api json files.
+
+The purpose of this tool is to remove the need for hand-written code that
+converts to and from base::Value types when receiving javascript api calls.
+Originally written for generating code for extension apis. Reference schemas
+are in chrome/common/extensions/api.
+
+Usage example:
+  compiler.py --root /home/Work/src --namespace extensions windows.json
+    tabs.json
+  compiler.py --destdir gen --suffix _api --root /home/Work/src
+    --namespace extensions windows.json tabs.json
+"""
+import model

[Yoyo Zhou, 2012/01/19 02:19:40]

Imports should be sorted.

[calamity, 2012/01/23 05:14:45]

Done.

+import os.path
+import json
+import cc_generator
+import h_generator
+import optparse
+import sys
+
+parser = optparse.OptionParser(
+    description='Generates a C++ model of an API from JSON schema',
+    usage='usage: %prog [option]... schema [referenced_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')
+parser.add_option('-n', '--namespace', default='generated_api_schemas',
+    help='C++ namespace for generated files')
+parser.add_option('-s', '--suffix', default='_api',
+    help='C++ namespace suffix for generated files')
+
+(opts, args) = parser.parse_args()

[Yoyo Zhou, 2012/01/19 02:19:40]

Looks like you want most of this file to be behind a __name__ == '__main__'
check.

[calamity, 2012/01/20 01:10:25]

Done.

+if not args:
+  sys.exit(parser.get_usage())
+dest_dir = opts.destdir
+root_namespace = opts.namespace
+filename_suffix = opts.suffix
+
+schema = os.path.normpath(args[0])
+referenced_schemas = args[1:]
+
+api_model = model.Model()
+
+# Load type dependencies into the model.
+for referenced_schema_path in referenced_schemas:
+  referenced_schema_path = os.path.normpath(referenced_schema_path)
+  referenced_schema_file = open(referenced_schema_path, 'r')
+  referenced_api_defs = json.loads(referenced_schema_file.read())
+  referenced_schema_file.close()
+
+  for namespace in referenced_api_defs:
+    api_model.add_namespace(namespace,
+        os.path.relpath(referenced_schema_path, opts.root), filename_suffix)
+
+# Actually generate for source file.
+schema_file = open(schema, 'r')
+api_defs = json.loads(schema_file.read())

[Nico, 2012/01/18 17:30:12]

with open(schema, 'r') as schema_file:
  api_defs = json.load(schema_file)

?

[calamity, 2012/01/20 01:10:25]

Done.

+schema_file.close()
+for target_namespace in api_defs:
+  # Gets the relative path from opts.root to the schema to correctly determine
+  # the include path.
+  relpath = os.path.relpath(schema, opts.root)
+  namespace = api_model.add_namespace(target_namespace, relpath,
+      filename_suffix)
+  if not namespace:
+    continue
+  cc_generator = cc_generator.CCGenerator(namespace, api_model, root_namespace)
+  cc_code = cc_generator.generate().render()
+  h_generator = h_generator.HGenerator(namespace, api_model, root_namespace)
+  h_code = h_generator.generate().render()
+  if dest_dir:
+    cc_file = open(os.path.join(dest_dir, namespace.source_file_dir,
+        namespace.target_namespace + '.cc'), 'w')

[Yoyo Zhou, 2012/01/19 02:19:40]

Is this going to put experimental APIs into files named like
experimental.webNavigation.cc?

You might also consider using the with/as pattern that thakis described above.

[calamity, 2012/01/20 01:10:25]

Hmm. Good point. Refactored this whole thing a bit. The model shouldn't have
dealt with the namespace name.

+    cc_file.write(cc_code)
+    cc_file.close()
+    h_file = open(os.path.join(dest_dir, namespace.source_file_dir,
+        namespace.target_namespace + '.h'), 'w')
+    h_file.write(h_code)
+    h_file.close()
+  else:
+    print '%s.h' % namespace.target_namespace
+    print
+    print h_code
+    print
+    print '%s.cc\n' % namespace.target_namespace
+    print
+    print cc_code