Down-integrate from internal code base.

10 files changed, 387 insertions, 102 deletions

diff --git a/src/google/protobuf/compiler/cpp/cpp_helpers.cc b/src/google/protobuf/compiler/cpp/cpp_helpers.cc
index 678a995a..09845458 100644
--- a/src/google/protobuf/compiler/cpp/cpp_helpers.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_helpers.cc
@@ -600,6 +600,94 @@ bool IsAnyMessage(const Descriptor* descriptor) {
          descriptor->file()->name() == kAnyProtoFile;
 }
 
+enum Utf8CheckMode {
+  STRICT = 0,  // Parsing will fail if non UTF-8 data is in string fields.
+  VERIFY = 1,  // Only log an error but parsing will succeed.
+  NONE = 2,  // No UTF-8 check.
+};
+
+// Which level of UTF-8 enforcemant is placed on this file.
+static Utf8CheckMode GetUtf8CheckMode(const FieldDescriptor* field) {
+  if (field->file()->syntax() == FileDescriptor::SYNTAX_PROTO3) {
+    return STRICT;
+  } else if (field->file()->options().optimize_for() !=
+             FileOptions::LITE_RUNTIME) {
+    return VERIFY;
+  } else {
+    return NONE;
+  }
+}
+
+static void GenerateUtf8CheckCode(const FieldDescriptor* field,
+                                  bool for_parse,
+                                  const map<string, string>& variables,
+                                  const char* parameters,
+                                  const char* strict_function,
+                                  const char* verify_function,
+                                  io::Printer* printer) {
+  switch (GetUtf8CheckMode(field)) {
+    case STRICT: {
+      if (for_parse) {
+        printer->Print("DO_(");
+      }
+      printer->Print(
+          "::google::protobuf::internal::WireFormatLite::$function$(\n",
+          "function", strict_function);
+      printer->Indent();
+      printer->Print(variables, parameters);
+      if (for_parse) {
+        printer->Print("::google::protobuf::internal::WireFormatLite::PARSE,\n");
+      } else {
+        printer->Print("::google::protobuf::internal::WireFormatLite::SERIALIZE,\n");
+      }
+      printer->Print("\"$full_name$\")", "full_name", field->full_name());
+      if (for_parse) {
+        printer->Print(")");
+      }
+      printer->Print(";\n");
+      printer->Outdent();
+      break;
+    }
+    case VERIFY: {
+      printer->Print(
+          "::google::protobuf::internal::WireFormat::$function$(\n",
+          "function", verify_function);
+      printer->Indent();
+      printer->Print(variables, parameters);
+      if (for_parse) {
+        printer->Print("::google::protobuf::internal::WireFormat::PARSE,\n");
+      } else {
+        printer->Print("::google::protobuf::internal::WireFormat::SERIALIZE,\n");
+      }
+      printer->Print("\"$full_name$\");\n", "full_name", field->full_name());
+      printer->Outdent();
+      break;
+    }
+    case NONE:
+      break;
+  }
+}
+
+void GenerateUtf8CheckCodeForString(const FieldDescriptor* field,
+                                    bool for_parse,
+                                    const map<string, string>& variables,
+                                    const char* parameters,
+                                    io::Printer* printer) {
+  GenerateUtf8CheckCode(field, for_parse, variables, parameters,
+                        "VerifyUtf8String", "VerifyUTF8StringNamedField",
+                        printer);
+}
+
+void GenerateUtf8CheckCodeForCord(const FieldDescriptor* field,
+                                  bool for_parse,
+                                  const map<string, string>& variables,
+                                  const char* parameters,
+                                  io::Printer* printer) {
+  GenerateUtf8CheckCode(field, for_parse, variables, parameters,
+                        "VerifyUtf8Cord", "VerifyUTF8CordNamedField",
+                        printer);
+}
+
 }  // namespace cpp
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/cpp/cpp_helpers.h b/src/google/protobuf/compiler/cpp/cpp_helpers.h
index 29c1f90b..985cb04c 100644
--- a/src/google/protobuf/compiler/cpp/cpp_helpers.h
+++ b/src/google/protobuf/compiler/cpp/cpp_helpers.h
@@ -202,11 +202,6 @@ inline bool HasGenericServices(const FileDescriptor* file) {
          file->options().cc_generic_services();
 }
 
-// Should string fields in this file verify that their contents are UTF-8?
-inline bool HasUtf8Verification(const FileDescriptor* file) {
-  return file->options().optimize_for() != FileOptions::LITE_RUNTIME;
-}
-
 // Should we generate a separate, super-optimized code path for serializing to
 // flat arrays?  We don't do this in Lite mode because we'd rather reduce code
 // size.
@@ -270,6 +265,20 @@ inline bool SupportsArenas(const FieldDescriptor* field) {
 bool IsAnyMessage(const FileDescriptor* descriptor);
 bool IsAnyMessage(const Descriptor* descriptor);
 
+void GenerateUtf8CheckCodeForString(
+    const FieldDescriptor* field,
+    bool for_parse,
+    const map<string, string>& variables,
+    const char* parameters,
+    io::Printer* printer);
+
+void GenerateUtf8CheckCodeForCord(
+    const FieldDescriptor* field,
+    bool for_parse,
+    const map<string, string>& variables,
+    const char* parameters,
+    io::Printer* printer);
+
 }  // namespace cpp
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/cpp/cpp_map_field.cc b/src/google/protobuf/compiler/cpp/cpp_map_field.cc
index a14d8986..25acc61b 100644
--- a/src/google/protobuf/compiler/cpp/cpp_map_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_map_field.cc
@@ -234,6 +234,20 @@ GenerateMergeFromCodedStream(io::Printer* printer) const {
         "}\n");
   }
 
+  const FieldDescriptor* key_field =
+      descriptor_->message_type()->FindFieldByName("key");
+  if (key_field->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        key_field, true, variables_,
+        "entry->key().data(), entry->key().length(),\n", printer);
+  }
+  if (value_field->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        value_field, true, variables_,
+        "entry->mutable_value()->data(),\n"
+        "entry->mutable_value()->length(),\n", printer);
+  }
+
   // If entry is allocated by arena, its desctructor should be avoided.
   if (SupportsArenas(descriptor_)) {
     printer->Print(variables_,
@@ -261,7 +275,30 @@ GenerateSerializeWithCachedSizes(io::Printer* printer) const {
   printer->Print(variables_,
       "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
       "    ::google::protobuf::internal::WireFormatLite::Write$stream_writer$(\n"
-      "        $number$, *entry, output);\n"
+      "        $number$, *entry, output);\n");
+
+  printer->Indent();
+  printer->Indent();
+
+  const FieldDescriptor* key_field =
+      descriptor_->message_type()->FindFieldByName("key");
+  const FieldDescriptor* value_field =
+      descriptor_->message_type()->FindFieldByName("value");
+  if (key_field->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        key_field, false, variables_,
+        "it->first.data(), it->first.length(),\n", printer);
+  }
+  if (value_field->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        value_field, false, variables_,
+        "it->second.data(), it->second.length(),\n", printer);
+  }
+
+  printer->Outdent();
+  printer->Outdent();
+
+  printer->Print(
       "  }\n");
 
   // If entry is allocated by arena, its desctructor should be avoided.
@@ -296,7 +333,29 @@ GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
       "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
       "    target = ::google::protobuf::internal::WireFormatLite::\n"
       "        Write$declared_type$NoVirtualToArray(\n"
-      "            $number$, *entry, target);\n"
+      "            $number$, *entry, target);\n");
+
+  printer->Indent();
+  printer->Indent();
+
+  const FieldDescriptor* key_field =
+      descriptor_->message_type()->FindFieldByName("key");
+  const FieldDescriptor* value_field =
+      descriptor_->message_type()->FindFieldByName("value");
+  if (key_field->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        key_field, false, variables_,
+        "it->first.data(), it->first.length(),\n", printer);
+  }
+  if (value_field->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        value_field, false, variables_,
+        "it->second.data(), it->second.length(),\n", printer);
+  }
+
+  printer->Outdent();
+  printer->Outdent();
+  printer->Print(
       "  }\n");
 
   // If entry is allocated by arena, its desctructor should be avoided.
diff --git a/src/google/protobuf/compiler/cpp/cpp_string_field.cc b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
index d1af6dda..6b0821a6 100644
--- a/src/google/protobuf/compiler/cpp/cpp_string_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
@@ -367,25 +367,19 @@ GenerateMergeFromCodedStream(io::Printer* printer) const {
     "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::VerifyUTF8StringNamedField(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::PARSE,\n"
-      "  \"$full_name$\");\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::VerifyUTF8StringNamedField(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::SERIALIZE,\n"
-      "  \"$full_name$\");\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$declared_type$MaybeAliased(\n"
@@ -394,13 +388,10 @@ GenerateSerializeWithCachedSizes(io::Printer* printer) const {
 
 void StringFieldGenerator::
 GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
-  if (HasUtf8Verification(descriptor_->file()) &&
-      descriptor_->type() == FieldDescriptor::TYPE_STRING) {
-    printer->Print(variables_,
-      "::google::protobuf::internal::WireFormat::VerifyUTF8StringNamedField(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::SERIALIZE,\n"
-      "  \"$full_name$\");\n");
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, false, variables_,
+        "this->$name$().data(), this->$name$().length(),\n", printer);
   }
   printer->Print(variables_,
     "target =\n"
@@ -665,13 +656,10 @@ GenerateMergeFromCodedStream(io::Printer* printer) const {
       "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::VerifyUTF8StringNamedField(\n"
-      "  this->$name$().data(), this->$name$().length(),\n"
-      "  ::google::protobuf::internal::WireFormat::PARSE,\n"
-      "  \"$full_name$\");\n");
+  if (descriptor_->type() == FieldDescriptor::TYPE_STRING) {
+    GenerateUtf8CheckCodeForString(
+        descriptor_, true, variables_,
+        "this->$name$().data(), this->$name$().length(),\n", printer);
   }
 }
 
@@ -817,14 +805,12 @@ 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::VerifyUTF8StringNamedField(\n"
-      "  this->$name$(this->$name$_size() - 1).data(),\n"
-      "  this->$name$(this->$name$_size() - 1).length(),\n"
-      "  ::google::protobuf::internal::WireFormat::PARSE,\n"
-      "  \"$full_name$\");\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);
   }
 }
 
@@ -832,14 +818,13 @@ 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::VerifyUTF8StringNamedField(\n"
-      "  this->$name$(i).data(), this->$name$(i).length(),\n"
-      "  ::google::protobuf::internal::WireFormat::SERIALIZE,\n"
-      "  \"$full_name$\");\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"
@@ -850,14 +835,13 @@ 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::VerifyUTF8StringNamedField(\n"
-      "    this->$name$(i).data(), this->$name$(i).length(),\n"
-      "    ::google::protobuf::internal::WireFormat::SERIALIZE,\n"
-      "    \"$full_name$\");\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"
diff --git a/src/google/protobuf/compiler/parser.cc b/src/google/protobuf/compiler/parser.cc
index 895ff34a..4d018425 100644
--- a/src/google/protobuf/compiler/parser.cc
+++ b/src/google/protobuf/compiler/parser.cc
@@ -939,6 +939,42 @@ void Parser::GenerateMapEntry(const MapField& map_field,
   } else {
     value_field->set_type_name(map_field.value_type_name);
   }
+  // Propagate the "enforce_utf8" option to key and value fields if they
+  // are strings. This helps simplify the implementation of code generators
+  // and also reflection-based parsing code.
+  //
+  // The following definition:
+  //   message Foo {
+  //     map<string, string> value = 1 [enforce_utf8 = false];
+  //   }
+  // will be interpreted as:
+  //   message Foo {
+  //     message ValueEntry {
+  //       option map_entry = true;
+  //       string key = 1 [enforce_utf8 = false];
+  //       string value = 2 [enforce_utf8 = false];
+  //     }
+  //     repeated ValueEntry value = 1 [enforce_utf8 = false];
+  //  }
+  //
+  // TODO(xiaofeng): Remove this when the "enforce_utf8" option is removed
+  // from protocol compiler.
+  for (int i = 0; i < field->options().uninterpreted_option_size(); ++i) {
+    const UninterpretedOption& option =
+        field->options().uninterpreted_option(i);
+    if (option.name_size() == 1 &&
+        option.name(0).name_part() == "enforce_utf8" &&
+        !option.name(0).is_extension()) {
+      if (key_field->type() == FieldDescriptorProto::TYPE_STRING) {
+        key_field->mutable_options()->add_uninterpreted_option()
+            ->CopyFrom(option);
+      }
+      if (value_field->type() == FieldDescriptorProto::TYPE_STRING) {
+        value_field->mutable_options()->add_uninterpreted_option()
+            ->CopyFrom(option);
+      }
+    }
+  }
 }
 
 bool Parser::ParseFieldOptions(FieldDescriptorProto* field,
diff --git a/src/google/protobuf/lite_arena_unittest.cc b/src/google/protobuf/lite_arena_unittest.cc
new file mode 100644
index 00000000..f0bee880
--- /dev/null
+++ b/src/google/protobuf/lite_arena_unittest.cc
@@ -0,0 +1,83 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// 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
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/arena_test_util.h>
+#include <google/protobuf/map_lite_test_util.h>
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+
+namespace google {
+namespace protobuf {
+namespace {
+
+TEST(LiteArenaTest, MapNoHeapAllocation) {
+  // Allocate a large initial block to avoid mallocs during hooked test.
+  std::vector<char> arena_block(128 * 1024);
+  google::protobuf::ArenaOptions options;
+  options.initial_block = &arena_block[0];
+  options.initial_block_size = arena_block.size();
+  google::protobuf::Arena arena(options);
+  string data;
+  data.reserve(128 * 1024);
+
+  {
+    // TODO(teboring): Enable no heap check when ArenaStringPtr is used in
+    // Map.
+    // google::protobuf::internal::NoHeapChecker no_heap;
+
+    protobuf_unittest::TestArenaMapLite* from =
+        google::protobuf::Arena::CreateMessage<protobuf_unittest::TestArenaMapLite>(&arena);
+    google::protobuf::MapLiteTestUtil::SetArenaMapFields(from);
+    from->SerializeToString(&data);
+
+    protobuf_unittest::TestArenaMapLite* to =
+        google::protobuf::Arena::CreateMessage<protobuf_unittest::TestArenaMapLite>(&arena);
+    to->ParseFromString(data);
+    google::protobuf::MapLiteTestUtil::ExpectArenaMapFieldsSet(*to);
+  }
+}
+
+TEST(LiteArenaTest, UnknownFieldMemLeak) {
+  google::protobuf::Arena arena;
+  protobuf_unittest::ForeignMessageArenaLite* message =
+      google::protobuf::Arena::CreateMessage<protobuf_unittest::ForeignMessageArenaLite>(
+          &arena);
+  string data = "\012\000";
+  int original_capacity = data.capacity();
+  while (data.capacity() <= original_capacity) {
+    data.append("a");
+  }
+  data[1] = data.size() - 2;
+  message->ParseFromString(data);
+}
+
+}  // namespace
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/wire_format.cc b/src/google/protobuf/wire_format.cc
index 8fbd116b..5ee4e25d 100644
--- a/src/google/protobuf/wire_format.cc
+++ b/src/google/protobuf/wire_format.cc
@@ -461,6 +461,10 @@ bool WireFormat::ParseAndMergeMessageSetField(uint32 field_number,
   }
 }
 
+static bool StrictUtf8Check(const FieldDescriptor* field) {
+  return field->file()->syntax() == FileDescriptor::SYNTAX_PROTO3;
+}
+
 bool WireFormat::ParseAndMergeField(
     uint32 tag,
     const FieldDescriptor* field,        // May be NULL for unknown
@@ -633,10 +637,19 @@ bool WireFormat::ParseAndMergeField(
 
       // Handle strings separately so that we can optimize the ctype=CORD case.
       case FieldDescriptor::TYPE_STRING: {
+        bool strict_utf8_check = StrictUtf8Check(field);
         string value;
         if (!WireFormatLite::ReadString(input, &value)) return false;
-        VerifyUTF8StringNamedField(value.data(), value.length(), PARSE,
-                                   field->name().c_str());
+        if (strict_utf8_check) {
+          if (!WireFormatLite::VerifyUtf8String(
+                  value.data(), value.length(), WireFormatLite::PARSE,
+                  field->full_name().c_str())) {
+            return false;
+          }
+        } else {
+          VerifyUTF8StringNamedField(value.data(), value.length(), PARSE,
+                                     field->full_name().c_str());
+        }
         if (field->is_repeated()) {
           message_reflection->AddString(message, field, value);
         } else {
@@ -894,13 +907,20 @@ void WireFormat::SerializeFieldWithCachedSizes(
       // Handle strings separately so that we can get string references
       // instead of copying.
       case FieldDescriptor::TYPE_STRING: {
+        bool strict_utf8_check = StrictUtf8Check(field);
         string scratch;
         const string& value = field->is_repeated() ?
           message_reflection->GetRepeatedStringReference(
             message, field, j, &scratch) :
           message_reflection->GetStringReference(message, field, &scratch);
-        VerifyUTF8StringNamedField(value.data(), value.length(), SERIALIZE,
-                                   field->name().c_str());
+        if (strict_utf8_check) {
+          WireFormatLite::VerifyUtf8String(value.data(), value.length(),
+                                           WireFormatLite::SERIALIZE,
+                                           field->full_name().c_str());
+        } else {
+          VerifyUTF8StringNamedField(value.data(), value.length(), SERIALIZE,
+                                     field->full_name().c_str());
+        }
         WireFormatLite::WriteString(field->number(), value, output);
         break;
       }
@@ -1108,34 +1128,6 @@ int WireFormat::MessageSetItemByteSize(
   return our_size;
 }
 
-void WireFormat::VerifyUTF8StringFallback(const char* data,
-                                          int size,
-                                          Operation op,
-                                          const char* field_name) {
-  if (!IsStructurallyValidUTF8(data, size)) {
-    const char* operation_str = NULL;
-    switch (op) {
-      case PARSE:
-        operation_str = "parsing";
-        break;
-      case SERIALIZE:
-        operation_str = "serializing";
-        break;
-      // no default case: have the compiler warn if a case is not covered.
-    }
-    string quoted_field_name = "";
-    if (field_name != NULL) {
-      quoted_field_name = StringPrintf(" '%s'", field_name);
-    }
-    // no space below to avoid double space when the field name is missing.
-    GOOGLE_LOG(ERROR) << "String field" << quoted_field_name << " contains invalid "
-               << "UTF-8 data when " << operation_str << " a protocol "
-               << "buffer. Use the 'bytes' type if you intend to send raw "
-               << "bytes. ";
-  }
-}
-
-
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google
diff --git a/src/google/protobuf/wire_format.h b/src/google/protobuf/wire_format.h
index 84270fee..941be75b 100644
--- a/src/google/protobuf/wire_format.h
+++ b/src/google/protobuf/wire_format.h
@@ -231,8 +231,8 @@ class LIBPROTOBUF_EXPORT WireFormat {
       const Message& message);
 
   enum Operation {
-    PARSE,
-    SERIALIZE,
+    PARSE = 0,
+    SERIALIZE = 1,
   };
 
   // Verifies that a string field is valid UTF8, logging an error if not.
@@ -247,13 +247,6 @@ class LIBPROTOBUF_EXPORT WireFormat {
                                          const char* field_name);
 
  private:
-  // Verifies that a string field is valid UTF8, logging an error if not.
-  static void VerifyUTF8StringFallback(
-      const char* data,
-      int size,
-      Operation op,
-      const char* field_name);
-
   // Skip a MessageSet field.
   static bool SkipMessageSetField(io::CodedInputStream* input,
                                   uint32 field_number,
@@ -265,8 +258,6 @@ class LIBPROTOBUF_EXPORT WireFormat {
                                            Message* message,
                                            io::CodedInputStream* input);
 
-
-
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(WireFormat);
 };
 
@@ -321,7 +312,8 @@ inline int WireFormat::TagSize(int field_number, FieldDescriptor::Type type) {
 inline void WireFormat::VerifyUTF8String(const char* data, int size,
     WireFormat::Operation op) {
 #ifdef GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
-  WireFormat::VerifyUTF8StringFallback(data, size, op, NULL);
+  WireFormatLite::VerifyUtf8String(
+      data, size, static_cast<WireFormatLite::Operation>(op), NULL);
 #else
   // Avoid the compiler warning about unsued variables.
   (void)data; (void)size; (void)op;
@@ -332,7 +324,8 @@ inline void WireFormat::VerifyUTF8StringNamedField(
     const char* data, int size, WireFormat::Operation op,
     const char* field_name) {
 #ifdef GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
-  WireFormat::VerifyUTF8StringFallback(data, size, op, field_name);
+  WireFormatLite::VerifyUtf8String(
+      data, size, static_cast<WireFormatLite::Operation>(op), field_name);
 #endif
 }
 
diff --git a/src/google/protobuf/wire_format_lite.cc b/src/google/protobuf/wire_format_lite.cc
index dade41af..847e3500 100644
--- a/src/google/protobuf/wire_format_lite.cc
+++ b/src/google/protobuf/wire_format_lite.cc
@@ -39,10 +39,12 @@
 #include <vector>
 #include <google/protobuf/stubs/logging.h>
 #include <google/protobuf/stubs/common.h>
+#include <google/protobuf/stubs/stringprintf.h>
 #include <google/protobuf/io/coded_stream_inl.h>
 #include <google/protobuf/io/zero_copy_stream.h>
 #include <google/protobuf/io/zero_copy_stream_impl_lite.h>
 
+
 namespace google {
 namespace protobuf {
 namespace internal {
@@ -505,6 +507,35 @@ bool WireFormatLite::ReadBytes(io::CodedInputStream* input, string** p) {
   return ReadBytesToString(input, *p);
 }
 
+bool WireFormatLite::VerifyUtf8String(const char* data,
+                                      int size,
+                                      Operation op,
+                                      const char* field_name) {
+  if (!IsStructurallyValidUTF8(data, size)) {
+    const char* operation_str = NULL;
+    switch (op) {
+      case PARSE:
+        operation_str = "parsing";
+        break;
+      case SERIALIZE:
+        operation_str = "serializing";
+        break;
+      // no default case: have the compiler warn if a case is not covered.
+    }
+    string quoted_field_name = "";
+    if (field_name != NULL) {
+      quoted_field_name = StringPrintf(" '%s'", field_name);
+    }
+    // no space below to avoid double space when the field name is missing.
+    GOOGLE_LOG(ERROR) << "String field" << quoted_field_name << " contains invalid "
+               << "UTF-8 data when " << operation_str << " a protocol "
+               << "buffer. Use the 'bytes' type if you intend to send raw "
+               << "bytes. ";
+    return false;
+  }
+  return true;
+}
+
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google
diff --git a/src/google/protobuf/wire_format_lite.h b/src/google/protobuf/wire_format_lite.h
index 19fbc2c5..55fc7ecd 100644
--- a/src/google/protobuf/wire_format_lite.h
+++ b/src/google/protobuf/wire_format_lite.h
@@ -316,6 +316,16 @@ class LIBPROTOBUF_EXPORT WireFormatLite {
   static bool ReadBytes(input, string** p);
 
 
+  enum Operation {
+    PARSE = 0,
+    SERIALIZE = 1,
+  };
+
+  // Returns true if the data is valid UTF-8.
+  static bool VerifyUtf8String(const char* data, int size,
+                               Operation op,
+                               const char* field_name);
+
   static inline bool ReadGroup  (field_number, input, MessageLite* value);
   static inline bool ReadMessage(input, MessageLite* value);