Mojo: Simplify typemap usage.

mojo/public/tools/bindings/format_typemap_generator_args.py

Index: mojo/public/tools/bindings/format_typemap_generator_args.py
diff --git a/mojo/public/tools/bindings/format_typemap_generator_args.py b/mojo/public/tools/bindings/format_typemap_generator_args.py
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+++ b/mojo/public/tools/bindings/format_typemap_generator_args.py
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+#!/usr/bin/env python
+# Copyright 2016 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.
+
+import sys
+
+# This utility converts mojom dependencies into their corresponding typemap
+# paths and formats them to be consumed by generate_type_mappings.py.
+
+
+def FormatTypemap(typemap_filename):
+  # A simple typemap is valid Python with a minor alteration.
+  with open(typemap_filename) as f:
+    typemap_content = f.read().replace('=\n', '=')
+  typemap = {}
+  exec typemap_content in typemap
+
+  for header in typemap.get('public_headers', []):
+    yield 'public_headers=%s' % header
+  for header in typemap.get('traits_headers', []):
+    yield 'traits_headers=%s' % header
+  for header in typemap.get('type_mappings', []):
+    yield 'type_mappings=%s' % header
+
+
+def main():
+  typemaps = sys.argv[1:]
+  print ' '.join('--start-typemap %s' % ' '.join(FormatTypemap(typemap))
+                 for typemap in typemaps)
+
+
+if __name__ == '__main__':
+  sys.exit(main())