Mojom: Add 'default' keyword for initializing structs to non-null value.

mojo/public/tools/bindings/generators/mojom_cpp_generator.py

 # Copyright 2013 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.
 
 """Generates C++ source files from a mojom.Module."""
 
 import mojom.generate.generator as generator
 import mojom.generate.module as mojom
 import mojom.generate.pack as pack
 from mojom.generate.template_expander import UseJinja
@@ skipping 11 matching lines @@
   mojom.HANDLE:       "mojo::Handle",
   mojom.DCPIPE:       "mojo::DataPipeConsumerHandle",
   mojom.DPPIPE:       "mojo::DataPipeProducerHandle",
   mojom.MSGPIPE:      "mojo::MessagePipeHandle",
   mojom.SHAREDBUFFER: "mojo::SharedBufferHandle",
   mojom.INT64:        "int64_t",
   mojom.UINT64:       "uint64_t",
   mojom.DOUBLE:       "double",
 }
 
+def DefaultValue(field):
+  if field.default:
+    if isinstance(field.kind, mojom.Struct):
+      assert field.default == "default"
+      return "%s::New()" % GetNameForKind(field.kind)
+    return ExpressionToText(field.default)
+  return ""
 
 def NamespaceToArray(namespace):
   return namespace.split('.') if namespace else []
 
 def GetNameForKind(kind, internal = False):
   parts = []
   if kind.imported_from:
     parts.extend(NamespaceToArray(kind.imported_from["namespace"]))
   if internal:
     parts.append("internal")
@@ skipping 179 matching lines @@
 
 class Generator(generator.Generator):
 
   cpp_filters = {
     "cpp_const_wrapper_type": GetCppConstWrapperType,
     "cpp_field_type": GetCppFieldType,
     "cpp_pod_type": GetCppPodType,
     "cpp_result_type": GetCppResultWrapperType,
     "cpp_type": GetCppType,
     "cpp_wrapper_type": GetCppWrapperType,
+    "default_value": DefaultValue,
     "expression_to_text": ExpressionToText,
     "get_pad": pack.GetPad,
     "has_callbacks": HasCallbacks,
     "should_inline": ShouldInlineStruct,
     "is_enum_kind": generator.IsEnumKind,
     "is_move_only_kind": generator.IsMoveOnlyKind,
     "is_handle_kind": generator.IsHandleKind,
     "is_interface_kind": generator.IsInterfaceKind,
     "is_interface_request_kind": generator.IsInterfaceRequestKind,
     "is_object_kind": generator.IsObjectKind,
     "is_string_kind": generator.IsStringKind,
-    "is_array_kind": lambda kind: isinstance(kind, mojom.Array),
     "is_struct_with_handles": IsStructWithHandles,
     "struct_size": lambda ps: ps.GetTotalSize() + _HEADER_SIZE,
     "struct_from_method": generator.GetStructFromMethod,
     "response_struct_from_method": generator.GetResponseStructFromMethod,
     "stylize_method": generator.StudlyCapsToCamel,
-    "verify_token_type": generator.VerifyTokenType,
   }
 
   def GetJinjaExports(self):
     return {
       "module": self.module,
       "namespace": self.module.namespace,
       "namespaces_as_array": NamespaceToArray(self.module.namespace),
       "imports": self.module.imports,
       "kinds": self.module.kinds,
       "enums": self.module.enums,
@@ skipping 11 matching lines @@
 
   @UseJinja("cpp_templates/module.cc.tmpl", filters=cpp_filters)
   def GenerateModuleSource(self):
     return self.GetJinjaExports()
 
   def GenerateFiles(self, args):
     self.Write(self.GenerateModuleHeader(), "%s.h" % self.module.name)
     self.Write(self.GenerateModuleInternalHeader(),
         "%s-internal.h" % self.module.name)
     self.Write(self.GenerateModuleSource(), "%s.cc" % self.module.name)