Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_string_field.cc

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
@@ skipping 31 matching lines @@
 
 namespace {
 
 void SetStringVariables(const FieldDescriptor* descriptor,
                         map<string, string>* variables,
                         const Options& options) {
   SetCommonFieldVariables(descriptor, variables, options);
   (*variables)["default"] = DefaultValue(descriptor);
   (*variables)["default_length"] =
       SimpleItoa(descriptor->default_value_string().length());
-  (*variables)["default_variable"] = descriptor->default_value_string().empty()
-      ? "&::google::protobuf::internal::GetEmptyString()"
-      : "_default_" + FieldName(descriptor) + "_";
+  string default_variable_string =
+      descriptor->default_value_string().empty()
+          ? "&::google::protobuf::internal::GetEmptyStringAlreadyInited()"
+          : "_default_" + FieldName(descriptor) + "_";
+  (*variables)["default_variable"] = default_variable_string;
+  (*variables)["default_value_init"] =
+      descriptor->default_value_string().empty()
+      ? "" : "*" + default_variable_string;
   (*variables)["pointer_type"] =
       descriptor->type() == FieldDescriptor::TYPE_BYTES ? "void" : "char";
+  // NOTE: Escaped here to unblock proto1->proto2 migration.
+  // TODO(liujisi): Extend this to apply for other conflicting methods.
+  (*variables)["release_name"] =
+      SafeFunctionName(descriptor->containing_type(),
+                       descriptor, "release_");
+  (*variables)["full_name"] = descriptor->full_name();
+
+  (*variables)["string_piece"] = "::std::string";
 }
 
 }  // namespace
 
 // ===================================================================
 
 StringFieldGenerator::
 StringFieldGenerator(const FieldDescriptor* descriptor,
                      const Options& options)
   : descriptor_(descriptor) {
   SetStringVariables(descriptor, &variables_, options);
 }
 
 StringFieldGenerator::~StringFieldGenerator() {}
 
 void StringFieldGenerator::
 GeneratePrivateMembers(io::Printer* printer) const {
-  printer->Print(variables_, "::std::string* $name$_;\n");
+  // N.B. that we continue to use |ArenaStringPtr| instead of |string*| for
+  // string fields, even when SupportArenas(descriptor_) == false. Why?
+  // The simple answer is to avoid unmaintainable complexity. The reflection
+  // code assumes ArenaStringPtrs. These are *almost* in-memory-compatible with
+  // string*, except for the pointer tags and related ownership semantics. We
+  // could modify the runtime code to use string* for the not-supporting-arenas
+  // case, but this would require a way to detect which type of class was
+  // generated (adding overhead and complexity to GeneratedMessageReflection)
+  // and littering the runtime code paths with conditionals. It's simpler to
+  // stick with this but use lightweight accessors that assume arena == NULL.
+  // There should be very little overhead anyway because it's just a tagged
+  // pointer in-memory.
+  printer->Print(variables_, "::google::protobuf::internal::ArenaStringPtr $name$_;\n");
+}
+
+void StringFieldGenerator::
+GenerateStaticMembers(io::Printer* printer) const {
   if (!descriptor_->default_value_string().empty()) {
     printer->Print(variables_, "static ::std::string* $default_variable$;\n");
   }
 }
 
 void StringFieldGenerator::
 GenerateAccessorDeclarations(io::Printer* printer) const {
   // If we're using StringFieldGenerator for a field with a ctype, it's
   // because that ctype isn't actually implemented.  In particular, this is
   // true of ctype=CORD and ctype=STRING_PIECE in the open source release.
   // We aren't releasing Cord because it has too many Google-specific
   // dependencies and we aren't releasing StringPiece because it's hardly
   // useful outside of Google and because it would get confusing to have
   // multiple instances of the StringPiece class in different libraries (PCRE
   // already includes it for their C++ bindings, which came from Google).
   //
   // In any case, we make all the accessors private while still actually
   // using a string to represent the field internally.  This way, we can
   // guarantee that if we do ever implement the ctype, it won't break any
   // existing users who might be -- for whatever reason -- already using .proto
   // files that applied the ctype.  The field can still be accessed via the
   // reflection interface since the reflection interface is independent of
   // the string's underlying representation.
-  if (descriptor_->options().ctype() != FieldOptions::STRING) {
+
+  bool unknown_ctype =
+      descriptor_->options().ctype() != EffectiveStringCType(descriptor_);
+
+  if (unknown_ctype) {
     printer->Outdent();
     printer->Print(
       " private:\n"
       "  // Hidden due to unknown ctype option.\n");
     printer->Indent();
   }
 
   printer->Print(variables_,
-    "inline const ::std::string& $name$() const$deprecation$;\n"
-    "inline void set_$name$(const ::std::string& value)$deprecation$;\n"
-    "inline void set_$name$(const char* value)$deprecation$;\n"
-    "inline void set_$name$(const $pointer_type$* value, size_t size)"
+    "const ::std::string& $name$() const$deprecation$;\n"
+    "void set_$name$(const ::std::string& value)$deprecation$;\n"
+    "void set_$name$(const char* value)$deprecation$;\n"
+    "void set_$name$(const $pointer_type$* value, size_t size)"
                  "$deprecation$;\n"
-    "inline ::std::string* mutable_$name$()$deprecation$;\n"
-    "inline ::std::string* release_$name$()$deprecation$;\n"
-    "inline void set_allocated_$name$(::std::string* $name$)$deprecation$;\n");
+    "::std::string* mutable_$name$()$deprecation$;\n"
+    "::std::string* $release_name$()$deprecation$;\n"
+    "void set_allocated_$name$(::std::string* $name$)$deprecation$;\n");
+  if (SupportsArenas(descriptor_)) {
+    printer->Print(variables_,
+      "::std::string* unsafe_arena_release_$name$()$deprecation$;\n"
+      "void unsafe_arena_set_allocated_$name$(\n"
+      "    ::std::string* $name$)$deprecation$;\n");
+  }
 
 
-  if (descriptor_->options().ctype() != FieldOptions::STRING) {
+  if (unknown_ctype) {
     printer->Outdent();
     printer->Print(" public:\n");
     printer->Indent();
   }
 }
 
 void StringFieldGenerator::
-GenerateInlineAccessorDefinitions(io::Printer* printer) const {
-  printer->Print(variables_,
-    "inline const ::std::string& $classname$::$name$() const {\n"
-    "  return *$name$_;\n"
-    "}\n"
-    "inline void $classname$::set_$name$(const ::std::string& value) {\n"
-    "  set_has_$name$();\n"
-    "  if ($name$_ == $default_variable$) {\n"
-    "    $name$_ = new ::std::string;\n"
-    "  }\n"
-    "  $name$_->assign(value);\n"
-    "}\n"
-    "inline void $classname$::set_$name$(const char* value) {\n"
-    "  set_has_$name$();\n"
-    "  if ($name$_ == $default_variable$) {\n"
-    "    $name$_ = new ::std::string;\n"
-    "  }\n"
-    "  $name$_->assign(value);\n"
-    "}\n"
-    "inline "
-    "void $classname$::set_$name$(const $pointer_type$* value, size_t size) {\n"
-    "  set_has_$name$();\n"
-    "  if ($name$_ == $default_variable$) {\n"
-    "    $name$_ = new ::std::string;\n"
-    "  }\n"
-    "  $name$_->assign(reinterpret_cast<const char*>(value), size);\n"
-    "}\n"
-    "inline ::std::string* $classname$::mutable_$name$() {\n"
-    "  set_has_$name$();\n"
-    "  if ($name$_ == $default_variable$) {\n");
-  if (descriptor_->default_value_string().empty()) {
-    printer->Print(variables_,
-      "    $name$_ = new ::std::string;\n");
+GenerateInlineAccessorDefinitions(io::Printer* printer,
+                                  bool is_inline) const {
+  map<string, string> variables(variables_);
+  variables["inline"] = is_inline ? "inline" : "";
+  if (SupportsArenas(descriptor_)) {
+    printer->Print(variables,
+      "$inline$ const ::std::string& $classname$::$name$() const {\n"
+      "  // @@protoc_insertion_point(field_get:$full_name$)\n"
+      "  return $name$_.Get($default_variable$);\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const ::std::string& value) {\n"
+      "  $set_hasbit$\n"
+      "  $name$_.Set($default_variable$, value, GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set:$full_name$)\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const char* value) {\n"
+      "  $set_hasbit$\n"
+      "  $name$_.Set($default_variable$, $string_piece$(value),\n"
+      "              GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set_char:$full_name$)\n"
+      "}\n"
+      "$inline$ "
+      "void $classname$::set_$name$(const $pointer_type$* value,\n"
+      "    size_t size) {\n"
+      "  $set_hasbit$\n"
+      "  $name$_.Set($default_variable$, $string_piece$(\n"
+      "      reinterpret_cast<const char*>(value), size), GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set_pointer:$full_name$)\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::mutable_$name$() {\n"
+      "  $set_hasbit$\n"
+      "  // @@protoc_insertion_point(field_mutable:$full_name$)\n"
+      "  return $name$_.Mutable($default_variable$, GetArenaNoVirtual());\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::$release_name$() {\n"
+      "  $clear_hasbit$\n"
+      "  return $name$_.Release($default_variable$, GetArenaNoVirtual());\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::unsafe_arena_release_$name$() {\n"
+      "  GOOGLE_DCHECK(GetArenaNoVirtual() != NULL);\n"
+      "  $clear_hasbit$\n"
+      "  return $name$_.UnsafeArenaRelease($default_variable$,\n"
+      "      GetArenaNoVirtual());\n"
+      "}\n"
+      "$inline$ void $classname$::set_allocated_$name$(::std::string* $name$) {\n"
+      "  if ($name$ != NULL) {\n"
+      "    $set_hasbit$\n"
+      "  } else {\n"
+      "    $clear_hasbit$\n"
+      "  }\n"
+      "  $name$_.SetAllocated($default_variable$, $name$,\n"
+      "      GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
+      "}\n"
+      "$inline$ void $classname$::unsafe_arena_set_allocated_$name$(\n"
+      "    ::std::string* $name$) {\n"
+      "  GOOGLE_DCHECK(GetArenaNoVirtual() != NULL);\n"
+      "  if ($name$ != NULL) {\n"
+      "    $set_hasbit$\n"
+      "  } else {\n"
+      "    $clear_hasbit$\n"
+      "  }\n"
+      "  $name$_.UnsafeArenaSetAllocated($default_variable$,\n"
+      "      $name$, GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
+      "}\n");
   } else {
-    printer->Print(variables_,
-      "    $name$_ = new ::std::string(*$default_variable$);\n");
+    // No-arena case.
+    printer->Print(variables,
+      "$inline$ const ::std::string& $classname$::$name$() const {\n"
+      "  // @@protoc_insertion_point(field_get:$full_name$)\n"
+      "  return $name$_.GetNoArena($default_variable$);\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const ::std::string& value) {\n"
+      "  $set_hasbit$\n"
+      "  $name$_.SetNoArena($default_variable$, value);\n"
+      "  // @@protoc_insertion_point(field_set:$full_name$)\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const char* value) {\n"
+      "  $set_hasbit$\n"
+      "  $name$_.SetNoArena($default_variable$, $string_piece$(value));\n"
+      "  // @@protoc_insertion_point(field_set_char:$full_name$)\n"
+      "}\n"
+      "$inline$ "
+      "void $classname$::set_$name$(const $pointer_type$* value, "
+      "size_t size) {\n"
+      "  $set_hasbit$\n"
+      "  $name$_.SetNoArena($default_variable$,\n"
+      "      $string_piece$(reinterpret_cast<const char*>(value), size));\n"
+      "  // @@protoc_insertion_point(field_set_pointer:$full_name$)\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::mutable_$name$() {\n"
+      "  $set_hasbit$\n"
+      "  // @@protoc_insertion_point(field_mutable:$full_name$)\n"
+      "  return $name$_.MutableNoArena($default_variable$);\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::$release_name$() {\n"
+      "  $clear_hasbit$\n"
+      "  return $name$_.ReleaseNoArena($default_variable$);\n"
+      "}\n"
+      "$inline$ void $classname$::set_allocated_$name$(::std::string* $name$) {\n"
+      "  if ($name$ != NULL) {\n"
+      "    $set_hasbit$\n"
+      "  } else {\n"
+      "    $clear_hasbit$\n"
+      "  }\n"
+      "  $name$_.SetAllocatedNoArena($default_variable$, $name$);\n"
+      "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
+      "}\n");
   }
-  printer->Print(variables_,
-    "  }\n"
-    "  return $name$_;\n"
-    "}\n"
-    "inline ::std::string* $classname$::release_$name$() {\n"
-    "  clear_has_$name$();\n"
-    "  if ($name$_ == $default_variable$) {\n"
-    "    return NULL;\n"
-    "  } else {\n"
-    "    ::std::string* temp = $name$_;\n"
-    "    $name$_ = const_cast< ::std::string*>($default_variable$);\n"
-    "    return temp;\n"
-    "  }\n"
-    "}\n"
-    "inline void $classname$::set_allocated_$name$(::std::string* $name$) {\n"
-    "  if ($name$_ != $default_variable$) {\n"
-    "    delete $name$_;\n"
-    "  }\n"
-    "  if ($name$) {\n"
-    "    set_has_$name$();\n"
-    "    $name$_ = $name$;\n"
-    "  } else {\n"
-    "    clear_has_$name$();\n"
-    "    $name$_ = const_cast< ::std::string*>($default_variable$);\n"
-    "  }\n"
-    "}\n");
 }
 
 void StringFieldGenerator::
 GenerateNonInlineAccessorDefinitions(io::Printer* printer) const {
   if (!descriptor_->default_value_string().empty()) {
     // Initialized in GenerateDefaultInstanceAllocator.
     printer->Print(variables_,
       "::std::string* $classname$::$default_variable$ = NULL;\n");
   }
 }
 
 void StringFieldGenerator::
 GenerateClearingCode(io::Printer* printer) const {
-  if (descriptor_->default_value_string().empty()) {
-    printer->Print(variables_,
-      "if ($name$_ != $default_variable$) {\n"
-      "  $name$_->clear();\n"
-      "}\n");
+  // Two-dimension specialization here: supporting arenas or not, and default
+  // value is the empty string or not. Complexity here ensures the minimal
+  // number of branches / amount of extraneous code at runtime (given that the
+  // below methods are inlined one-liners)!
+  if (SupportsArenas(descriptor_)) {
+    if (descriptor_->default_value_string().empty()) {
+      printer->Print(variables_,
+        "$name$_.ClearToEmpty($default_variable$, GetArenaNoVirtual());\n");
+    } else {
+      printer->Print(variables_,
+        "$name$_.ClearToDefault($default_variable$, GetArenaNoVirtual());\n");
+    }
   } else {
-    printer->Print(variables_,
-      "if ($name$_ != $default_variable$) {\n"
-      "  $name$_->assign(*$default_variable$);\n"
-      "}\n");
+    if (descriptor_->default_value_string().empty()) {
+      printer->Print(variables_,
+        "$name$_.ClearToEmptyNoArena($default_variable$);\n");
+    } else {
+      printer->Print(variables_,
+        "$name$_.ClearToDefaultNoArena($default_variable$);\n");
+    }
   }
 }
 
 void StringFieldGenerator::
 GenerateMergingCode(io::Printer* printer) const {
-  printer->Print(variables_, "set_$name$(from.$name$());\n");
+  if (SupportsArenas(descriptor_) || descriptor_->containing_oneof() != NULL) {
+    // TODO(gpike): improve this
+    printer->Print(variables_, "set_$name$(from.$name$());\n");
+  } else {
+    printer->Print(variables_,
+      "$set_hasbit$\n"
+      "$name$_.AssignWithDefault($default_variable$, from.$name$_);\n");
+  }
 }
 
 void StringFieldGenerator::
 GenerateSwappingCode(io::Printer* printer) const {
-  printer->Print(variables_, "std::swap($name$_, other->$name$_);\n");
+  printer->Print(variables_, "$name$_.Swap(&other->$name$_);\n");
 }
 
 void StringFieldGenerator::
 GenerateConstructorCode(io::Printer* printer) const {
   printer->Print(variables_,
-    "$name$_ = const_cast< ::std::string*>($default_variable$);\n");
+      "$name$_.UnsafeSetDefault($default_variable$);\n");
 }
 
 void StringFieldGenerator::
 GenerateDestructorCode(io::Printer* printer) const {
-  printer->Print(variables_,
-    "if ($name$_ != $default_variable$) {\n"
-    "  delete $name$_;\n"
-    "}\n");
+  if (SupportsArenas(descriptor_)) {
+    printer->Print(variables_,
+      "$name$_.Destroy($default_variable$, GetArenaNoVirtual());\n");
+  } else {
+    printer->Print(variables_,
+      "$name$_.DestroyNoArena($default_variable$);\n");
+  }
 }
 
 void StringFieldGenerator::
 GenerateDefaultInstanceAllocator(io::Printer* printer) const {
   if (!descriptor_->default_value_string().empty()) {
     printer->Print(variables_,
       "$classname$::$default_variable$ =\n"
       "    new ::std::string($default$, $default_length$);\n");
   }
 }
 
 void StringFieldGenerator::
 GenerateShutdownCode(io::Printer* printer) const {
   if (!descriptor_->default_value_string().empty()) {
     printer->Print(variables_,
       "delete $classname$::$default_variable$;\n");
   }
 }
 
 void StringFieldGenerator::
 GenerateMergeFromCodedStream(io::Printer* printer) const {
   printer->Print(variables_,
     "DO_(::google::protobuf::internal::WireFormatLite::Read$declared_type$(\n"
     "      input, this->mutable_$name$()));\n");
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "::google::protobuf::internal::WireFormat::VerifyUTF8String(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::PARSE);\n");
+
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, true, variables_,
+        "this->$name$().data(), this->$name$().length(),\n", printer);
   }
 }
 
 void StringFieldGenerator::
 GenerateSerializeWithCachedSizes(io::Printer* printer) const {
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "::google::protobuf::internal::WireFormat::VerifyUTF8String(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::SERIALIZE);\n");
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, false, variables_,
+        "this->$name$().data(), this->$name$().length(),\n", printer);
   }
   printer->Print(variables_,
-    "::google::protobuf::internal::WireFormatLite::Write$declared_type$(\n"
+    "::google::protobuf::internal::WireFormatLite::Write$declared_type$MaybeAliased(\n"
     "  $number$, this->$name$(), output);\n");
 }
 
 void StringFieldGenerator::
 GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "::google::protobuf::internal::WireFormat::VerifyUTF8String(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::SERIALIZE);\n");
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, false, variables_,
+        "this->$name$().data(), this->$name$().length(),\n", printer);
   }
   printer->Print(variables_,
     "target =\n"
     "  ::google::protobuf::internal::WireFormatLite::Write$declared_type$ToArray(\n"
     "    $number$, this->$name$(), target);\n");
 }
 
 void StringFieldGenerator::
 GenerateByteSize(io::Printer* printer) const {
   printer->Print(variables_,
     "total_size += $tag_size$ +\n"
     "  ::google::protobuf::internal::WireFormatLite::$declared_type$Size(\n"
     "    this->$name$());\n");
 }
 
 // ===================================================================
 
+StringOneofFieldGenerator::
+StringOneofFieldGenerator(const FieldDescriptor* descriptor,
+                          const Options& options)
+    : StringFieldGenerator(descriptor, options),
+      dependent_field_(options.proto_h) {
+  SetCommonOneofFieldVariables(descriptor, &variables_);
+}
+
+StringOneofFieldGenerator::~StringOneofFieldGenerator() {}
+
+void StringOneofFieldGenerator::
+GenerateInlineAccessorDefinitions(io::Printer* printer,
+                                  bool is_inline) const {
+  map<string, string> variables(variables_);
+  variables["inline"] = is_inline ? "inline" : "";
+  if (SupportsArenas(descriptor_)) {
+    printer->Print(variables,
+      "$inline$ const ::std::string& $classname$::$name$() const {\n"
+      "  // @@protoc_insertion_point(field_get:$full_name$)\n"
+      "  if (has_$name$()) {\n"
+      "    return $oneof_prefix$$name$_.Get($default_variable$);\n"
+      "  }\n"
+      "  return *$default_variable$;\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const ::std::string& value) {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  $oneof_prefix$$name$_.Set($default_variable$, value,\n"
+      "      GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set:$full_name$)\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const char* value) {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  $oneof_prefix$$name$_.Set($default_variable$,\n"
+      "      $string_piece$(value), GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set_char:$full_name$)\n"
+      "}\n"
+      "$inline$ "
+      "void $classname$::set_$name$(const $pointer_type$* value,\n"
+      "                             size_t size) {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  $oneof_prefix$$name$_.Set($default_variable$, $string_piece$(\n"
+      "      reinterpret_cast<const char*>(value), size),\n"
+      "      GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_set_pointer:$full_name$)\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::mutable_$name$() {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  return $oneof_prefix$$name$_.Mutable($default_variable$,\n"
+      "      GetArenaNoVirtual());\n"
+      "  // @@protoc_insertion_point(field_mutable:$full_name$)\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::$release_name$() {\n"
+      "  if (has_$name$()) {\n"
+      "    clear_has_$oneof_name$();\n"
+      "    return $oneof_prefix$$name$_.Release($default_variable$,\n"
+      "        GetArenaNoVirtual());\n"
+      "  } else {\n"
+      "    return NULL;\n"
+      "  }\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::unsafe_arena_release_$name$() {\n"
+      "  GOOGLE_DCHECK(GetArenaNoVirtual() != NULL);\n"
+      "  if (has_$name$()) {\n"
+      "    clear_has_$oneof_name$();\n"
+      "    return $oneof_prefix$$name$_.UnsafeArenaRelease(\n"
+      "        $default_variable$, GetArenaNoVirtual());\n"
+      "  } else {\n"
+      "    return NULL;\n"
+      "  }\n"
+      "}\n"
+      "$inline$ void $classname$::set_allocated_$name$(::std::string* $name$) {\n"
+      "  if (!has_$name$()) {\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  clear_$oneof_name$();\n"
+      "  if ($name$ != NULL) {\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.SetAllocated($default_variable$, $name$,\n"
+      "        GetArenaNoVirtual());\n"
+      "  }\n"
+      "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
+      "}\n"
+      "$inline$ void $classname$::unsafe_arena_set_allocated_$name$("
+      "::std::string* $name$) {\n"
+      "  GOOGLE_DCHECK(GetArenaNoVirtual() != NULL);\n"
+      "  if (!has_$name$()) {\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  clear_$oneof_name$();\n"
+      "  if ($name$) {\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeArenaSetAllocated($default_variable$, "
+      "$name$, GetArenaNoVirtual());\n"
+      "  }\n"
+      "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
+      "}\n");
+  } else {
+    // No-arena case.
+    printer->Print(variables,
+      "$inline$ const ::std::string& $classname$::$name$() const {\n"
+      "  // @@protoc_insertion_point(field_get:$full_name$)\n"
+      "  if (has_$name$()) {\n"
+      "    return $oneof_prefix$$name$_.GetNoArena($default_variable$);\n"
+      "  }\n"
+      "  return *$default_variable$;\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const ::std::string& value) {\n"
+      "  // @@protoc_insertion_point(field_set:$full_name$)\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  $oneof_prefix$$name$_.SetNoArena($default_variable$, value);\n"
+      "  // @@protoc_insertion_point(field_set:$full_name$)\n"
+      "}\n"
+      "$inline$ void $classname$::set_$name$(const char* value) {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  $oneof_prefix$$name$_.SetNoArena($default_variable$,\n"
+      "      $string_piece$(value));\n"
+      "  // @@protoc_insertion_point(field_set_char:$full_name$)\n"
+      "}\n"
+      "$inline$ "
+      "void $classname$::set_$name$(const $pointer_type$* value, size_t size) {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  $oneof_prefix$$name$_.SetNoArena($default_variable$, $string_piece$(\n"
+      "      reinterpret_cast<const char*>(value), size));\n"
+      "  // @@protoc_insertion_point(field_set_pointer:$full_name$)\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::mutable_$name$() {\n"
+      "  if (!has_$name$()) {\n"
+      "    clear_$oneof_name$();\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  // @@protoc_insertion_point(field_mutable:$full_name$)\n"
+      "  return $oneof_prefix$$name$_.MutableNoArena($default_variable$);\n"
+      "}\n"
+      "$inline$ ::std::string* $classname$::$release_name$() {\n"
+      "  if (has_$name$()) {\n"
+      "    clear_has_$oneof_name$();\n"
+      "    return $oneof_prefix$$name$_.ReleaseNoArena($default_variable$);\n"
+      "  } else {\n"
+      "    return NULL;\n"
+      "  }\n"
+      "}\n"
+      "$inline$ void $classname$::set_allocated_$name$(::std::string* $name$) {\n"
+      "  if (!has_$name$()) {\n"
+      "    $oneof_prefix$$name$_.UnsafeSetDefault($default_variable$);\n"
+      "  }\n"
+      "  clear_$oneof_name$();\n"
+      "  if ($name$ != NULL) {\n"
+      "    set_has_$name$();\n"
+      "    $oneof_prefix$$name$_.SetAllocatedNoArena($default_variable$,\n"
+      "        $name$);\n"
+      "  }\n"
+      "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
+      "}\n");
+  }
+}
+
+void StringOneofFieldGenerator::
+GenerateClearingCode(io::Printer* printer) const {
+  map<string, string> variables(variables_);
+  if (dependent_field_) {
+    variables["this_message"] = DependentBaseDownCast();
+    // This clearing code may be in the dependent base class. If the default
+    // value is an empty string, then the $default_variable$ is a global
+    // singleton. If the default is not empty, we need to down-cast to get the
+    // default value's global singleton instance. See SetStringVariables() for
+    // possible values of default_variable.
+    if (!descriptor_->default_value_string().empty()) {
+      variables["default_variable"] =
+          DependentBaseDownCast() + variables["default_variable"];
+    }
+  } else {
+    variables["this_message"] = "";
+  }
+  if (SupportsArenas(descriptor_)) {
+    printer->Print(variables,
+      "$this_message$$oneof_prefix$$name$_.Destroy($default_variable$,\n"
+      "    $this_message$GetArenaNoVirtual());\n");
+  } else {
+    printer->Print(variables,
+      "$this_message$$oneof_prefix$$name$_."
+      "DestroyNoArena($default_variable$);\n");
+  }
+}
+
+void StringOneofFieldGenerator::
+GenerateSwappingCode(io::Printer* printer) const {
+  // Don't print any swapping code. Swapping the union will swap this field.
+}
+
+void StringOneofFieldGenerator::
+GenerateConstructorCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "  $classname$_default_oneof_instance_->$name$_.UnsafeSetDefault("
+    "$default_variable$);\n");
+}
+
+void StringOneofFieldGenerator::
+GenerateDestructorCode(io::Printer* printer) const {
+  if (SupportsArenas(descriptor_)) {
+    printer->Print(variables_,
+      "if (has_$name$()) {\n"
+      "  $oneof_prefix$$name$_.Destroy($default_variable$,\n"
+      "      GetArenaNoVirtual());\n"
+      "}\n");
+  } else {
+    printer->Print(variables_,
+      "if (has_$name$()) {\n"
+      "  $oneof_prefix$$name$_.DestroyNoArena($default_variable$);\n"
+      "}\n");
+  }
+}
+
+void StringOneofFieldGenerator::
+GenerateMergeFromCodedStream(io::Printer* printer) const {
+    printer->Print(variables_,
+      "DO_(::google::protobuf::internal::WireFormatLite::Read$declared_type$(\n"
+      "      input, this->mutable_$name$()));\n");
+
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, true, variables_,
+        "this->$name$().data(), this->$name$().length(),\n", printer);
+  }
+}
+
+
+// ===================================================================
+
 RepeatedStringFieldGenerator::
 RepeatedStringFieldGenerator(const FieldDescriptor* descriptor,
                              const Options& options)
-  : descriptor_(descriptor) {
+    : descriptor_(descriptor) {
   SetStringVariables(descriptor, &variables_, options);
 }
 
 RepeatedStringFieldGenerator::~RepeatedStringFieldGenerator() {}
 
 void RepeatedStringFieldGenerator::
 GeneratePrivateMembers(io::Printer* printer) const {
   printer->Print(variables_,
     "::google::protobuf::RepeatedPtrField< ::std::string> $name$_;\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateAccessorDeclarations(io::Printer* printer) const {
   // See comment above about unknown ctypes.
-  if (descriptor_->options().ctype() != FieldOptions::STRING) {
+  bool unknown_ctype =
+      descriptor_->options().ctype() != EffectiveStringCType(descriptor_);
+
+  if (unknown_ctype) {
     printer->Outdent();
     printer->Print(
       " private:\n"
       "  // Hidden due to unknown ctype option.\n");
     printer->Indent();
   }
 
   printer->Print(variables_,
-    "inline const ::std::string& $name$(int index) const$deprecation$;\n"
-    "inline ::std::string* mutable_$name$(int index)$deprecation$;\n"
-    "inline void set_$name$(int index, const ::std::string& value)$deprecation$;\n"
-    "inline void set_$name$(int index, const char* value)$deprecation$;\n"
-    "inline "
+    "const ::std::string& $name$(int index) const$deprecation$;\n"
+    "::std::string* mutable_$name$(int index)$deprecation$;\n"
+    "void set_$name$(int index, const ::std::string& value)$deprecation$;\n"
+    "void set_$name$(int index, const char* value)$deprecation$;\n"
+    ""
     "void set_$name$(int index, const $pointer_type$* value, size_t size)"
                  "$deprecation$;\n"
-    "inline ::std::string* add_$name$()$deprecation$;\n"
-    "inline void add_$name$(const ::std::string& value)$deprecation$;\n"
-    "inline void add_$name$(const char* value)$deprecation$;\n"
-    "inline void add_$name$(const $pointer_type$* value, size_t size)"
+    "::std::string* add_$name$()$deprecation$;\n"
+    "void add_$name$(const ::std::string& value)$deprecation$;\n"
+    "void add_$name$(const char* value)$deprecation$;\n"
+    "void add_$name$(const $pointer_type$* value, size_t size)"
                  "$deprecation$;\n");
 
   printer->Print(variables_,
-    "inline const ::google::protobuf::RepeatedPtrField< ::std::string>& $name$() const"
+    "const ::google::protobuf::RepeatedPtrField< ::std::string>& $name$() const"
                  "$deprecation$;\n"
-    "inline ::google::protobuf::RepeatedPtrField< ::std::string>* mutable_$name$()"
+    "::google::protobuf::RepeatedPtrField< ::std::string>* mutable_$name$()"
                  "$deprecation$;\n");
 
-  if (descriptor_->options().ctype() != FieldOptions::STRING) {
+  if (unknown_ctype) {
     printer->Outdent();
     printer->Print(" public:\n");
     printer->Indent();
   }
 }
 
 void RepeatedStringFieldGenerator::
-GenerateInlineAccessorDefinitions(io::Printer* printer) const {
-  printer->Print(variables_,
-    "inline const ::std::string& $classname$::$name$(int index) const {\n"
+GenerateInlineAccessorDefinitions(io::Printer* printer,
+                                  bool is_inline) const {
+  map<string, string> variables(variables_);
+  variables["inline"] = is_inline ? "inline" : "";
+  printer->Print(variables,
+    "$inline$ const ::std::string& $classname$::$name$(int index) const {\n"
+    "  // @@protoc_insertion_point(field_get:$full_name$)\n"
     "  return $name$_.$cppget$(index);\n"
     "}\n"
-    "inline ::std::string* $classname$::mutable_$name$(int index) {\n"
+    "$inline$ ::std::string* $classname$::mutable_$name$(int index) {\n"
+    "  // @@protoc_insertion_point(field_mutable:$full_name$)\n"
     "  return $name$_.Mutable(index);\n"
     "}\n"
-    "inline void $classname$::set_$name$(int index, const ::std::string& value) {\n"
+    "$inline$ void $classname$::set_$name$(int index, const ::std::string& value) {\n"
+    "  // @@protoc_insertion_point(field_set:$full_name$)\n"
     "  $name$_.Mutable(index)->assign(value);\n"
     "}\n"
-    "inline void $classname$::set_$name$(int index, const char* value) {\n"
+    "$inline$ void $classname$::set_$name$(int index, const char* value) {\n"
     "  $name$_.Mutable(index)->assign(value);\n"
+    "  // @@protoc_insertion_point(field_set_char:$full_name$)\n"
     "}\n"
-    "inline void "
+    "$inline$ void "
     "$classname$::set_$name$"
     "(int index, const $pointer_type$* value, size_t size) {\n"
     "  $name$_.Mutable(index)->assign(\n"
     "    reinterpret_cast<const char*>(value), size);\n"
+    "  // @@protoc_insertion_point(field_set_pointer:$full_name$)\n"
     "}\n"
-    "inline ::std::string* $classname$::add_$name$() {\n"
+    "$inline$ ::std::string* $classname$::add_$name$() {\n"
     "  return $name$_.Add();\n"
     "}\n"
-    "inline void $classname$::add_$name$(const ::std::string& value) {\n"
+    "$inline$ void $classname$::add_$name$(const ::std::string& value) {\n"
     "  $name$_.Add()->assign(value);\n"
+    "  // @@protoc_insertion_point(field_add:$full_name$)\n"
     "}\n"
-    "inline void $classname$::add_$name$(const char* value) {\n"
+    "$inline$ void $classname$::add_$name$(const char* value) {\n"
     "  $name$_.Add()->assign(value);\n"
+    "  // @@protoc_insertion_point(field_add_char:$full_name$)\n"
     "}\n"
-    "inline void "
+    "$inline$ void "
     "$classname$::add_$name$(const $pointer_type$* value, size_t size) {\n"
     "  $name$_.Add()->assign(reinterpret_cast<const char*>(value), size);\n"
+    "  // @@protoc_insertion_point(field_add_pointer:$full_name$)\n"
     "}\n");
-  printer->Print(variables_,
-    "inline const ::google::protobuf::RepeatedPtrField< ::std::string>&\n"
+  printer->Print(variables,
+    "$inline$ const ::google::protobuf::RepeatedPtrField< ::std::string>&\n"
     "$classname$::$name$() const {\n"
+    "  // @@protoc_insertion_point(field_list:$full_name$)\n"
     "  return $name$_;\n"
     "}\n"
-    "inline ::google::protobuf::RepeatedPtrField< ::std::string>*\n"
+    "$inline$ ::google::protobuf::RepeatedPtrField< ::std::string>*\n"
     "$classname$::mutable_$name$() {\n"
+    "  // @@protoc_insertion_point(field_mutable_list:$full_name$)\n"
     "  return &$name$_;\n"
     "}\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateClearingCode(io::Printer* printer) const {
   printer->Print(variables_, "$name$_.Clear();\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateMergingCode(io::Printer* printer) const {
   printer->Print(variables_, "$name$_.MergeFrom(from.$name$_);\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateSwappingCode(io::Printer* printer) const {
-  printer->Print(variables_, "$name$_.Swap(&other->$name$_);\n");
+  printer->Print(variables_, "$name$_.UnsafeArenaSwap(&other->$name$_);\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateConstructorCode(io::Printer* printer) const {
   // Not needed for repeated fields.
 }
 
 void RepeatedStringFieldGenerator::
 GenerateMergeFromCodedStream(io::Printer* printer) const {
   printer->Print(variables_,
     "DO_(::google::protobuf::internal::WireFormatLite::Read$declared_type$(\n"
     "      input, this->add_$name$()));\n");
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "::google::protobuf::internal::WireFormat::VerifyUTF8String(\n"
-      "  this->$name$(this->$name$_size() - 1).data(),\n"
-      "  this->$name$(this->$name$_size() - 1).length(),\n"
-      "  ::google::protobuf::internal::WireFormat::PARSE);\n");
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, true, variables_,
+        "this->$name$(this->$name$_size() - 1).data(),\n"
+        "this->$name$(this->$name$_size() - 1).length(),\n",
+        printer);
   }
 }
 
 void RepeatedStringFieldGenerator::
 GenerateSerializeWithCachedSizes(io::Printer* printer) const {
   printer->Print(variables_,
     "for (int i = 0; i < this->$name$_size(); i++) {\n");
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "::google::protobuf::internal::WireFormat::VerifyUTF8String(\n"
-      "  this->$name$(i).data(), this->$name$(i).length(),\n"
-      "  ::google::protobuf::internal::WireFormat::SERIALIZE);\n");
+  printer->Indent();
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, false, variables_,
+        "this->$name$(i).data(), this->$name$(i).length(),\n", printer);
   }
+  printer->Outdent();
   printer->Print(variables_,
     "  ::google::protobuf::internal::WireFormatLite::Write$declared_type$(\n"
     "    $number$, this->$name$(i), output);\n"
     "}\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
   printer->Print(variables_,
     "for (int i = 0; i < this->$name$_size(); i++) {\n");
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "  ::google::protobuf::internal::WireFormat::VerifyUTF8String(\n"
-      "    this->$name$(i).data(), this->$name$(i).length(),\n"
-      "    ::google::protobuf::internal::WireFormat::SERIALIZE);\n");
+  printer->Indent();
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, false, variables_,
+        "this->$name$(i).data(), this->$name$(i).length(),\n", printer);
   }
+  printer->Outdent();
   printer->Print(variables_,
     "  target = ::google::protobuf::internal::WireFormatLite::\n"
     "    Write$declared_type$ToArray($number$, this->$name$(i), target);\n"
     "}\n");
 }
 
 void RepeatedStringFieldGenerator::
 GenerateByteSize(io::Printer* printer) const {
   printer->Print(variables_,
     "total_size += $tag_size$ * this->$name$_size();\n"
     "for (int i = 0; i < this->$name$_size(); i++) {\n"
     "  total_size += ::google::protobuf::internal::WireFormatLite::$declared_type$Size(\n"
     "    this->$name$(i));\n"
     "}\n");
 }
 
 }  // namespace cpp
 }  // namespace compiler
 }  // namespace protobuf
 }  // namespace google