Mojo C++ bindings: support mapping T and T? differently.

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 135 matching lines @@
 
 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):
+    pattern = "WTF::Optional<%s>" if _for_blink else "base::Optional<%s>"
+    return pattern % type_name
+
   if IsTypemappedKind(kind):
-    return GetNativeTypeName(kind)
+    type_name = GetNativeTypeName(kind)
+    if (mojom.IsNullableKind(kind) and
+        not _current_typemap[GetFullMojomNameForKind(kind)][
+           "nullable_is_same_type"]):
+      type_name = _AddOptional(type_name)
+    return type_name
   if mojom.IsEnumKind(kind):
     return GetNameForKind(kind)
   if mojom.IsStructKind(kind) or mojom.IsUnionKind(kind):
     return "%sPtr" % GetNameForKind(kind)
   if mojom.IsArrayKind(kind):
     pattern = None
     if _use_new_wrapper_types:
+      pattern = "WTF::Vector<%s>" if _for_blink else "std::vector<%s>"
       if mojom.IsNullableKind(kind):
-        pattern = ("WTF::Optional<WTF::Vector<%s>>" if _for_blink else
-            "base::Optional<std::vector<%s>>")
-      else:
-        pattern = "WTF::Vector<%s>" if _for_blink else "std::vector<%s>"
+        pattern = _AddOptional(pattern)
     else:
       pattern = "mojo::WTFArray<%s>" if _for_blink else "mojo::Array<%s>"
     return pattern % GetCppWrapperType(kind.kind)
   if mojom.IsMapKind(kind):
     pattern = None
     if _use_new_wrapper_types:
+      pattern = ("WTF::HashMap<%s, %s>" if _for_blink else
+                 "std::unordered_map<%s, %s>")
       if mojom.IsNullableKind(kind):
-        pattern = ("WTF::Optional<WTF::HashMap<%s, %s>>" if _for_blink else
-                   "base::Optional<std::unordered_map<%s, %s>>")
-      else:
-        pattern = ("WTF::HashMap<%s, %s>" if _for_blink else
-                   "std::unordered_map<%s, %s>")
+        pattern = _AddOptional(pattern)
     else:
       pattern = "mojo::WTFMap<%s, %s>" if _for_blink else "mojo::Map<%s, %s>"
     return pattern % (GetCppWrapperType(kind.key_kind),
                       GetCppWrapperType(kind.value_kind))
   if mojom.IsInterfaceKind(kind):
     return "%sPtr" % GetNameForKind(kind)
   if mojom.IsInterfaceRequestKind(kind):
     return "%sRequest" % GetNameForKind(kind.kind)
   if mojom.IsAssociatedInterfaceKind(kind):
     return "%sAssociatedPtrInfo" % GetNameForKind(kind.kind)
   if mojom.IsAssociatedInterfaceRequestKind(kind):
     return "%sAssociatedRequest" % GetNameForKind(kind.kind)
   if mojom.IsStringKind(kind):
     if _for_blink:
       return "WTF::String"
     if not _use_new_wrapper_types:
       return "mojo::String"
-    return ("base::Optional<std::string>" if mojom.IsNullableKind(kind) else
-            "std::string")
+    type_name = "std::string"
+    return _AddOptional(type_name) if mojom.IsNullableKind(kind) else type_name
   if mojom.IsGenericHandleKind(kind):
     return "mojo::ScopedHandle"
   if mojom.IsDataPipeConsumerKind(kind):
     return "mojo::ScopedDataPipeConsumerHandle"
   if mojom.IsDataPipeProducerKind(kind):
     return "mojo::ScopedDataPipeProducerHandle"
   if mojom.IsMessagePipeKind(kind):
     return "mojo::ScopedMessagePipeHandle"
   if mojom.IsSharedBufferKind(kind):
     return "mojo::ScopedSharedBufferHandle"
@@ skipping 311 matching lines @@
     _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.GenerateModuleInternalHeader(),
         self.MatchMojomFilePath("%s%s-internal.h" % (self.module.name, suffix)))
     self.Write(self.GenerateModuleSource(),
         self.MatchMojomFilePath("%s%s.cc" % (self.module.name, suffix)))