Allow Mojo structs as map keys

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 154 matching lines @@
   return _NameFormatter(kind, _variant).FormatForMojom()
 
 def IsTypemappedKind(kind):
   return hasattr(kind, "name") and \
       GetFullMojomNameForKind(kind) in _current_typemap
 
 def IsNativeOnlyKind(kind):
   return (mojom.IsStructKind(kind) or mojom.IsEnumKind(kind)) and \
       kind.native_only
 
+
+def IsHashableKind(kind):
+  """Check if the kind can be hashed.
+
+  Args:
+    kind: {Kind} The kind to check.
+
+  Returns:
+    {bool} True if a value of this kind can be hashed.
+  """
+  checked = set()
+  def Check(kind):
+    if kind.spec in checked:
+      return True
+    checked.add(kind.spec)
+    if mojom.IsNullableKind(kind):
+      return False
+    elif mojom.IsStructKind(kind):
+      if (kind.native_only or
+          (IsTypemappedKind(kind) and
+           not _current_typemap[GetFullMojomNameForKind(kind)]["hashable"])):
+        return False
+      return all(Check(field.kind) for field in kind.fields)
+    elif mojom.IsUnionKind(kind):
+      return all(Check(field.kind) for field in kind.fields)
+    elif mojom.IsAnyHandleKind(kind):
+      return False
+    elif mojom.IsAnyInterfaceKind(kind):
+      return False
+    elif mojom.IsArrayKind(kind):
+      return False
+    elif mojom.IsMapKind(kind):
+      return False
+    else:
+      return True
+  return Check(kind)
+
+
 def GetNativeTypeName(typemapped_kind):
   return _current_typemap[GetFullMojomNameForKind(typemapped_kind)]["typename"]
 
 def GetCppPodType(kind):
   if mojom.IsStringKind(kind):
     return "char*"
   return _kind_to_cpp_type[kind]
 
 def GetCppWrapperType(kind):
   def _AddOptional(type_name):
@@ skipping 273 matching lines @@
       not mojom.IsStringKind(kind)):
     return "nullptr"
 
   return "new mojo::internal::ContainerValidateParams(%s)" % (
       GetContainerValidateParamsCtorArgs(kind))
 
 class Generator(generator.Generator):
 
   cpp_filters = {
     "constant_value": ConstantValue,
+    "contains_handles": mojom.ContainsHandles,
     "contains_move_only_members": ContainsMoveOnlyMembers,
     "cpp_wrapper_param_type": GetCppWrapperParamType,
     "cpp_data_view_type": GetCppDataViewType,
     "cpp_field_type": GetCppFieldType,
     "cpp_union_field_type": GetCppUnionFieldType,
     "cpp_pod_type": GetCppPodType,
     "cpp_union_getter_return_type": GetUnionGetterReturnType,
     "cpp_wrapper_type": GetCppWrapperType,
     "default_value": DefaultValue,
     "expression_to_text": ExpressionToText,
     "get_container_validate_params_ctor_args":
         GetContainerValidateParamsCtorArgs,
     "get_name_for_kind": GetNameForKind,
     "get_pad": pack.GetPad,
     "get_qualified_name_for_kind": GetQualifiedNameForKind,
     "has_callbacks": mojom.HasCallbacks,
     "has_sync_methods": mojom.HasSyncMethods,
     "requires_context_for_data_view": RequiresContextForDataView,
     "should_inline": ShouldInlineStruct,
     "should_inline_union": ShouldInlineUnion,
     "is_array_kind": mojom.IsArrayKind,
     "is_enum_kind": mojom.IsEnumKind,
     "is_integral_kind": mojom.IsIntegralKind,
     "is_native_only_kind": IsNativeOnlyKind,
     "is_any_handle_kind": mojom.IsAnyHandleKind,
     "is_any_interface_kind": mojom.IsAnyInterfaceKind,
     "is_any_handle_or_interface_kind": mojom.IsAnyHandleOrInterfaceKind,
     "is_associated_kind": mojom.IsAssociatedKind,
+    "is_hashable": IsHashableKind,
     "is_map_kind": mojom.IsMapKind,
     "is_nullable_kind": mojom.IsNullableKind,
     "is_object_kind": mojom.IsObjectKind,
     "is_string_kind": mojom.IsStringKind,
     "is_struct_kind": mojom.IsStructKind,
     "is_typemapped_kind": IsTypemappedKind,
     "is_union_kind": mojom.IsUnionKind,
     "passes_associated_kinds": mojom.PassesAssociatedKinds,
     "struct_size": lambda ps: ps.GetTotalSize() + _HEADER_SIZE,
     "stylize_method": generator.StudlyCapsToCamel,
@@ skipping 87 matching lines @@
       global _use_new_wrapper_types
       _use_new_wrapper_types = self.use_new_wrapper_types
       global _variant
       _variant = self.variant
       suffix = "-%s" % self.variant if self.variant else ""
       self.Write(self.GenerateModuleHeader(),
                  self.MatchMojomFilePath("%s%s.h" % (self.module.name, suffix)))
       self.Write(
           self.GenerateModuleSource(),
           self.MatchMojomFilePath("%s%s.cc" % (self.module.name, suffix)))