third_party/protobuf: update to upstream r415.

1) Got an upstream diff 412:415 from svn
2) Applied and fixed conflicts in cpp_message.cc
3) Added -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER in protobuf.gyp

Note that this removes 52 static initializers previously generated by protoc.


Review URL: https://chromiumcodereview.appspot.com/10382099

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136585 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 347 insertions, 126 deletions

diff --git a/third_party/protobuf/README.chromium b/third_party/protobuf/README.chromium
index df9f1c0..c421f17 100644
--- a/third_party/protobuf/README.chromium
+++ b/third_party/protobuf/README.chromium
@@ -3,7 +3,7 @@ Short Name: protobuf
 URL: http://protobuf.googlecode.com/svn/trunk
 License File: COPYING.txt
 Version: unknown
-Revision: r412
+Revision: r415
 Security Critical: yes
 
 Local files (not taken from upstream):
diff --git a/third_party/protobuf/protobuf.gyp b/third_party/protobuf/protobuf.gyp
index a0ab85a..4385785 100644
--- a/third_party/protobuf/protobuf.gyp
+++ b/third_party/protobuf/protobuf.gyp
@@ -87,6 +87,7 @@
       # which requires RTTI.
       'defines': [
         'GOOGLE_PROTOBUF_NO_RTTI',
+        'GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER',
       ],
 
       'direct_dependent_settings': {
@@ -96,6 +97,7 @@
         ],
         'defines': [
           'GOOGLE_PROTOBUF_NO_RTTI',
+          'GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER',
         ],
       },
     },
diff --git a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_file.cc b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_file.cc
index 810600b..3e6d414 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_file.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_file.cc
@@ -386,11 +386,12 @@ void FileGenerator::GenerateSource(io::Printer* printer) {
 
 void FileGenerator::GenerateBuildDescriptors(io::Printer* printer) {
   // AddDescriptors() is a file-level procedure which adds the encoded
-  // FileDescriptorProto for this .proto file to the global DescriptorPool
-  // for generated files (DescriptorPool::generated_pool()).  It always runs
-  // at static initialization time, so all files will be registered before
-  // main() starts.  This procedure also constructs default instances and
-  // registers extensions.
+  // FileDescriptorProto for this .proto file to the global DescriptorPool for
+  // generated files (DescriptorPool::generated_pool()). It either runs at
+  // static initialization time (by default) or when default_instance() is
+  // called for the first time (in LITE_RUNTIME mode with
+  // GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER flag enabled). This procedure also
+  // constructs default instances and registers extensions.
   //
   // Its sibling, AssignDescriptors(), actually pulls the compiled
   // FileDescriptor from the DescriptorPool and uses it to populate all of
@@ -494,22 +495,27 @@ void FileGenerator::GenerateBuildDescriptors(io::Printer* printer) {
 
   printer->Outdent();
   printer->Print(
-    "}\n");
+    "}\n\n");
 
   // -----------------------------------------------------------------
 
   // Now generate the AddDescriptors() function.
-  printer->Print(
-    "\n"
+  PrintHandlingOptionalStaticInitializers(
+    file_, printer,
+    // With static initializers.
+    // Note that we don't need any special synchronization in the following code
+    // because it is called at static init time before any threads exist.
     "void $adddescriptorsname$() {\n"
-    // We don't need any special synchronization here because this code is
-    // called at static init time before any threads exist.
     "  static bool already_here = false;\n"
     "  if (already_here) return;\n"
     "  already_here = true;\n"
-    "  GOOGLE_PROTOBUF_VERIFY_VERSION;\n"
-    "\n",
+    "  GOOGLE_PROTOBUF_VERIFY_VERSION;\n",
+    // Without.
+    "void $adddescriptorsname$_impl() {\n"
+    "  GOOGLE_PROTOBUF_VERIFY_VERSION;\n",
+    // Vars.
     "adddescriptorsname", GlobalAddDescriptorsName(file_->name()));
+
   printer->Indent();
 
   // Call the AddDescriptors() methods for all of our dependencies, to make
@@ -577,17 +583,26 @@ void FileGenerator::GenerateBuildDescriptors(io::Printer* printer) {
     "shutdownfilename", GlobalShutdownFileName(file_->name()));
 
   printer->Outdent();
-
   printer->Print(
     "}\n"
-    "\n"
+    "\n");
+
+  PrintHandlingOptionalStaticInitializers(
+    file_, printer,
+    // With static initializers.
     "// Force AddDescriptors() to be called at static initialization time.\n"
     "struct StaticDescriptorInitializer_$filename$ {\n"
     "  StaticDescriptorInitializer_$filename$() {\n"
     "    $adddescriptorsname$();\n"
     "  }\n"
-    "} static_descriptor_initializer_$filename$_;\n"
-    "\n",
+    "} static_descriptor_initializer_$filename$_;\n",
+    // Without.
+    "GOOGLE_PROTOBUF_DECLARE_ONCE($adddescriptorsname$_once_);\n"
+    "void $adddescriptorsname$() {\n"
+    "  ::google::protobuf::GoogleOnceInit(&$adddescriptorsname$_once_,\n"
+    "                 &$adddescriptorsname$_impl);\n"
+    "}\n",
+    // Vars.
     "adddescriptorsname", GlobalAddDescriptorsName(file_->name()),
     "filename", FilenameIdentifier(file_->name()));
 }
diff --git a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.cc b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.cc
index 25b05a8..c4b868c 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.cc
@@ -33,10 +33,12 @@
 //  Sanjay Ghemawat, Jeff Dean, and others.
 
 #include <limits>
+#include <map>
 #include <vector>
 #include <google/protobuf/stubs/hash.h>
 
 #include <google/protobuf/compiler/cpp/cpp_helpers.h>
+#include <google/protobuf/io/printer.h>
 #include <google/protobuf/stubs/common.h>
 #include <google/protobuf/stubs/strutil.h>
 #include <google/protobuf/stubs/substitute.h>
@@ -105,6 +107,20 @@ string UnderscoresToCamelCase(const string& input, bool cap_next_letter) {
   return result;
 }
 
+// Returns whether the provided descriptor has an extension. This includes its
+// nested types.
+bool HasExtension(const Descriptor* descriptor) {
+  if (descriptor->extension_count() > 0) {
+    return true;
+  }
+  for (int i = 0; i < descriptor->nested_type_count(); ++i) {
+    if (HasExtension(descriptor->nested_type(i))) {
+      return true;
+    }
+  }
+  return false;
+}
+
 }  // namespace
 
 const char kThickSeparator[] =
@@ -341,6 +357,50 @@ string EscapeTrigraphs(const string& to_escape) {
   return StringReplace(to_escape, "?", "\\?", true);
 }
 
+bool StaticInitializersForced(const FileDescriptor* file) {
+  if (HasDescriptorMethods(file) || file->extension_count() > 0) {
+    return true;
+  }
+  for (int i = 0; i < file->message_type_count(); ++i) {
+    if (HasExtension(file->message_type(i))) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void PrintHandlingOptionalStaticInitializers(
+    const FileDescriptor* file, io::Printer* printer,
+    const char* with_static_init, const char* without_static_init,
+    const char* var1, const string& val1,
+    const char* var2, const string& val2) {
+  map<string, string> vars;
+  if (var1) {
+    vars[var1] = val1;
+  }
+  if (var2) {
+    vars[var2] = val2;
+  }
+  PrintHandlingOptionalStaticInitializers(
+      vars, file, printer, with_static_init, without_static_init);
+}
+
+void PrintHandlingOptionalStaticInitializers(
+    const map<string, string>& vars, const FileDescriptor* file,
+    io::Printer* printer, const char* with_static_init,
+    const char* without_static_init) {
+  if (StaticInitializersForced(file)) {
+    printer->Print(vars, with_static_init);
+  } else {
+    printer->Print(vars, (string(
+      "#ifdef GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER\n") +
+      without_static_init +
+      "#else\n" +
+      with_static_init +
+      "#endif\n").c_str());
+  }
+}
+
 }  // namespace cpp
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.h b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.h
index ac06398..690fbec 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.h
+++ b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_helpers.h
@@ -35,12 +35,18 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_CPP_HELPERS_H__
 #define GOOGLE_PROTOBUF_COMPILER_CPP_HELPERS_H__
 
+#include <map>
 #include <string>
 #include <google/protobuf/descriptor.h>
 #include <google/protobuf/descriptor.pb.h>
 
 namespace google {
 namespace protobuf {
+
+namespace io {
+class Printer;
+}
+
 namespace compiler {
 namespace cpp {
 
@@ -151,6 +157,22 @@ inline bool HasFastArraySerialization(const FileDescriptor* file) {
   return file->options().optimize_for() == FileOptions::SPEED;
 }
 
+// Returns whether we have to generate code with static initializers.
+bool StaticInitializersForced(const FileDescriptor* file);
+
+// Prints 'with_static_init' if static initializers have to be used for the
+// provided file. Otherwise emits both 'with_static_init' and
+// 'without_static_init' using #ifdef.
+void PrintHandlingOptionalStaticInitializers(
+    const FileDescriptor* file, io::Printer* printer,
+    const char* with_static_init, const char* without_static_init,
+    const char* var1 = NULL, const string& val1 = "",
+    const char* var2 = NULL, const string& val2 = "");
+
+void PrintHandlingOptionalStaticInitializers(
+    const map<string, string>& vars, const FileDescriptor* file,
+    io::Printer* printer, const char* with_static_init,
+    const char* without_static_init);
 
 }  // namespace cpp
 }  // namespace compiler
diff --git a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc
index b836fb6..4248747 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc
@@ -493,6 +493,19 @@ GenerateClassDefinition(io::Printer* printer) {
     "static const $classname$& default_instance();\n"
     "\n");
 
+  if (!StaticInitializersForced(descriptor_->file())) {
+    printer->Print(vars,
+      "#ifdef GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER\n"
+      "// Returns the internal default instance pointer. This function can\n"
+      "// return NULL thus should not be used by the user. This is intended\n"
+      "// for Protobuf internal code. Please use default_instance() declared\n"
+      "// above instead.\n"
+      "static inline const $classname$* internal_default_instance() {\n"
+      "  return default_instance_;\n"
+      "}\n"
+      "#endif\n"
+      "\n");
+  }
 
   printer->Print(vars,
     "void Swap($classname$* other);\n"
@@ -660,11 +673,17 @@ GenerateClassDefinition(io::Printer* printer) {
   // Declare AddDescriptors(), BuildDescriptors(), and ShutdownFile() as
   // friends so that they can access private static variables like
   // default_instance_ and reflection_.
-  printer->Print(
+  PrintHandlingOptionalStaticInitializers(
+    descriptor_->file(), printer,
+    // With static initializers.
     "friend void $dllexport_decl$ $adddescriptorsname$();\n",
+    // Without.
+    "friend void $dllexport_decl$ $adddescriptorsname$_impl();\n",
+    // Vars.
     "dllexport_decl", dllexport_decl_,
     "adddescriptorsname",
-      GlobalAddDescriptorsName(descriptor_->file()->name()));
+    GlobalAddDescriptorsName(descriptor_->file()->name()));
+
   printer->Print(
     "friend void $assigndescriptorsname$();\n"
     "friend void $shutdownfilename$();\n"
@@ -981,8 +1000,12 @@ GenerateSharedDestructorCode(io::Printer* printer) {
                      .GenerateDestructorCode(printer);
   }
 
-  printer->Print(
-    "if (this != default_instance_) {\n");
+  PrintHandlingOptionalStaticInitializers(
+    descriptor_->file(), printer,
+    // With static initializers.
+    "if (this != default_instance_) {\n",
+    // Without.
+    "if (this != &default_instance()) {\n");
 
   // We need to delete all embedded messages.
   // TODO(kenton):  If we make unset messages point at default instances
@@ -1034,10 +1057,16 @@ GenerateStructors(io::Printer* printer) {
 
     if (!field->is_repeated() &&
         field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) {
-      printer->Print(
-          "  $name$_ = const_cast< $type$*>(&$type$::default_instance());\n",
-          "name", FieldName(field),
-          "type", FieldMessageTypeName(field));
+      PrintHandlingOptionalStaticInitializers(
+        descriptor_->file(), printer,
+        // With static initializers.
+        "  $name$_ = const_cast< $type$*>(&$type$::default_instance());\n",
+        // Without.
+        "  $name$_ = const_cast< $type$*>(\n"
+        "      $type$::internal_default_instance());\n",
+        // Vars.
+        "name", FieldName(field),
+        "type", FieldMessageTypeName(field));
     }
   }
   printer->Print(
@@ -1093,8 +1122,20 @@ GenerateStructors(io::Printer* printer) {
   }
 
   printer->Print(
-    "const $classname$& $classname$::default_instance() {\n"
-    "  if (default_instance_ == NULL) $adddescriptorsname$();"
+    "const $classname$& $classname$::default_instance() {\n",
+    "classname", classname_);
+
+  PrintHandlingOptionalStaticInitializers(
+    descriptor_->file(), printer,
+    // With static initializers.
+    "  if (default_instance_ == NULL) $adddescriptorsname$();\n",
+    // Without.
+    "  $adddescriptorsname$();\n",
+    // Vars.
+    "adddescriptorsname",
+    GlobalAddDescriptorsName(descriptor_->file()->name()));
+
+  printer->Print(
     "  return *default_instance_;\n"
     "}\n"
     "\n"
@@ -1106,7 +1147,6 @@ GenerateStructors(io::Printer* printer) {
     "classname", classname_,
     "adddescriptorsname",
     GlobalAddDescriptorsName(descriptor_->file()->name()));
-
 }
 
 void MessageGenerator::
@@ -1377,11 +1417,22 @@ GenerateMergeFromCodedStream(io::Printer* printer) {
     // Special-case MessageSet.
     printer->Print(
       "bool $classname$::MergePartialFromCodedStream(\n"
-      "    ::google::protobuf::io::CodedInputStream* input) {\n"
+      "    ::google::protobuf::io::CodedInputStream* input) {\n",
+      "classname", classname_);
+
+    PrintHandlingOptionalStaticInitializers(
+      descriptor_->file(), printer,
+      // With static initializers.
       "  return _extensions_.ParseMessageSet(input, default_instance_,\n"
-      "                                      mutable_unknown_fields());\n"
-      "}\n",
+      "                                      mutable_unknown_fields());\n",
+      // Without.
+      "  return _extensions_.ParseMessageSet(input, &default_instance(),\n"
+      "                                      mutable_unknown_fields());\n",
+      // Vars.
       "classname", classname_);
+
+    printer->Print(
+      "}\n");
     return;
   }
 
@@ -1541,12 +1592,21 @@ GenerateMergeFromCodedStream(io::Printer* printer) {
     }
     printer->Print(") {\n");
     if (HasUnknownFields(descriptor_->file())) {
-      printer->Print(
+      PrintHandlingOptionalStaticInitializers(
+        descriptor_->file(), printer,
+        // With static initializers.
         "  DO_(_extensions_.ParseField(tag, input, default_instance_,\n"
+        "                              mutable_unknown_fields()));\n",
+        // Without.
+        "  DO_(_extensions_.ParseField(tag, input, &default_instance(),\n"
         "                              mutable_unknown_fields()));\n");
     } else {
-      printer->Print(
-        "  DO_(_extensions_.ParseField(tag, input, default_instance_, NULL));\n");
+      PrintHandlingOptionalStaticInitializers(
+        descriptor_->file(), printer,
+        // With static initializers.
+        "  DO_(_extensions_.ParseField(tag, input, default_instance_, NULL));\n",
+        // Without.
+        "  DO_(_extensions_.ParseField(tag, input, &default_instance(), NULL));\n");
     }
     printer->Print(
       "  continue;\n"
diff --git a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message_field.cc b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message_field.cc
index 23e75b8..7c785e7 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message_field.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message_field.cc
@@ -82,8 +82,16 @@ GenerateAccessorDeclarations(io::Printer* printer) const {
 void MessageFieldGenerator::
 GenerateInlineAccessorDefinitions(io::Printer* printer) const {
   printer->Print(variables_,
-    "inline const $type$& $classname$::$name$() const {\n"
-    "  return $name$_ != NULL ? *$name$_ : *default_instance_->$name$_;\n"
+    "inline const $type$& $classname$::$name$() const {\n");
+
+  PrintHandlingOptionalStaticInitializers(
+    variables_, descriptor_->file(), printer,
+    // With static initializers.
+    "  return $name$_ != NULL ? *$name$_ : *default_instance_->$name$_;\n",
+    // Without.
+    "  return $name$_ != NULL ? *$name$_ : *default_instance().$name$_;\n");
+
+  printer->Print(variables_,
     "}\n"
     "inline $type$* $classname$::mutable_$name$() {\n"
     "  set_has_$name$();\n"
diff --git a/third_party/protobuf/src/google/protobuf/compiler/plugin.pb.cc b/third_party/protobuf/src/google/protobuf/compiler/plugin.pb.cc
index 75b5ffb..1d27b41 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/plugin.pb.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/plugin.pb.cc
@@ -124,7 +124,6 @@ void protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto() {
   if (already_here) return;
   already_here = true;
   GOOGLE_PROTOBUF_VERIFY_VERSION;
-
   ::google::protobuf::protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
   ::google::protobuf::DescriptorPool::InternalAddGeneratedFile(
     "\n%google/protobuf/compiler/plugin.proto\022"
@@ -155,7 +154,6 @@ struct StaticDescriptorInitializer_google_2fprotobuf_2fcompiler_2fplugin_2eproto
   }
 } static_descriptor_initializer_google_2fprotobuf_2fcompiler_2fplugin_2eproto_;
 
-
 // ===================================================================
 
 #ifndef _MSC_VER
@@ -207,7 +205,8 @@ const ::google::protobuf::Descriptor* CodeGeneratorRequest::descriptor() {
 }
 
 const CodeGeneratorRequest& CodeGeneratorRequest::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto();
+  return *default_instance_;
 }
 
 CodeGeneratorRequest* CodeGeneratorRequest::default_instance_ = NULL;
@@ -529,7 +528,8 @@ const ::google::protobuf::Descriptor* CodeGeneratorResponse_File::descriptor() {
 }
 
 const CodeGeneratorResponse_File& CodeGeneratorResponse_File::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto();
+  return *default_instance_;
 }
 
 CodeGeneratorResponse_File* CodeGeneratorResponse_File::default_instance_ = NULL;
@@ -857,7 +857,8 @@ const ::google::protobuf::Descriptor* CodeGeneratorResponse::descriptor() {
 }
 
 const CodeGeneratorResponse& CodeGeneratorResponse::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fcompiler_2fplugin_2eproto();
+  return *default_instance_;
 }
 
 CodeGeneratorResponse* CodeGeneratorResponse::default_instance_ = NULL;
diff --git a/third_party/protobuf/src/google/protobuf/descriptor.pb.cc b/third_party/protobuf/src/google/protobuf/descriptor.pb.cc
index 468b433..47595bb 100644
--- a/third_party/protobuf/src/google/protobuf/descriptor.pb.cc
+++ b/third_party/protobuf/src/google/protobuf/descriptor.pb.cc
@@ -554,7 +554,6 @@ void protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto() {
   if (already_here) return;
   already_here = true;
   GOOGLE_PROTOBUF_VERIFY_VERSION;
-
   ::google::protobuf::DescriptorPool::InternalAddGeneratedFile(
     "\n google/protobuf/descriptor.proto\022\017goog"
     "le.protobuf\"G\n\021FileDescriptorSet\0222\n\004file"
@@ -708,7 +707,6 @@ struct StaticDescriptorInitializer_google_2fprotobuf_2fdescriptor_2eproto {
   }
 } static_descriptor_initializer_google_2fprotobuf_2fdescriptor_2eproto_;
 
-
 // ===================================================================
 
 #ifndef _MSC_VER
@@ -754,7 +752,8 @@ const ::google::protobuf::Descriptor* FileDescriptorSet::descriptor() {
 }
 
 const FileDescriptorSet& FileDescriptorSet::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 FileDescriptorSet* FileDescriptorSet::default_instance_ = NULL;
@@ -980,7 +979,8 @@ const ::google::protobuf::Descriptor* FileDescriptorProto::descriptor() {
 }
 
 const FileDescriptorProto& FileDescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 FileDescriptorProto* FileDescriptorProto::default_instance_ = NULL;
@@ -1559,7 +1559,8 @@ const ::google::protobuf::Descriptor* DescriptorProto_ExtensionRange::descriptor
 }
 
 const DescriptorProto_ExtensionRange& DescriptorProto_ExtensionRange::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 DescriptorProto_ExtensionRange* DescriptorProto_ExtensionRange::default_instance_ = NULL;
@@ -1815,7 +1816,8 @@ const ::google::protobuf::Descriptor* DescriptorProto::descriptor() {
 }
 
 const DescriptorProto& DescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 DescriptorProto* DescriptorProto::default_instance_ = NULL;
@@ -2390,7 +2392,8 @@ const ::google::protobuf::Descriptor* FieldDescriptorProto::descriptor() {
 }
 
 const FieldDescriptorProto& FieldDescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 FieldDescriptorProto* FieldDescriptorProto::default_instance_ = NULL;
@@ -2944,7 +2947,8 @@ const ::google::protobuf::Descriptor* EnumDescriptorProto::descriptor() {
 }
 
 const EnumDescriptorProto& EnumDescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 EnumDescriptorProto* EnumDescriptorProto::default_instance_ = NULL;
@@ -3259,7 +3263,8 @@ const ::google::protobuf::Descriptor* EnumValueDescriptorProto::descriptor() {
 }
 
 const EnumValueDescriptorProto& EnumValueDescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 EnumValueDescriptorProto* EnumValueDescriptorProto::default_instance_ = NULL;
@@ -3569,7 +3574,8 @@ const ::google::protobuf::Descriptor* ServiceDescriptorProto::descriptor() {
 }
 
 const ServiceDescriptorProto& ServiceDescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 ServiceDescriptorProto* ServiceDescriptorProto::default_instance_ = NULL;
@@ -3892,7 +3898,8 @@ const ::google::protobuf::Descriptor* MethodDescriptorProto::descriptor() {
 }
 
 const MethodDescriptorProto& MethodDescriptorProto::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 MethodDescriptorProto* MethodDescriptorProto::default_instance_ = NULL;
@@ -4306,7 +4313,8 @@ const ::google::protobuf::Descriptor* FileOptions::descriptor() {
 }
 
 const FileOptions& FileOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 FileOptions* FileOptions::default_instance_ = NULL;
@@ -4908,7 +4916,8 @@ const ::google::protobuf::Descriptor* MessageOptions::descriptor() {
 }
 
 const MessageOptions& MessageOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 MessageOptions* MessageOptions::default_instance_ = NULL;
@@ -5242,7 +5251,8 @@ const ::google::protobuf::Descriptor* FieldOptions::descriptor() {
 }
 
 const FieldOptions& FieldOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 FieldOptions* FieldOptions::default_instance_ = NULL;
@@ -5638,7 +5648,8 @@ const ::google::protobuf::Descriptor* EnumOptions::descriptor() {
 }
 
 const EnumOptions& EnumOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 EnumOptions* EnumOptions::default_instance_ = NULL;
@@ -5861,7 +5872,8 @@ const ::google::protobuf::Descriptor* EnumValueOptions::descriptor() {
 }
 
 const EnumValueOptions& EnumValueOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 EnumValueOptions* EnumValueOptions::default_instance_ = NULL;
@@ -6084,7 +6096,8 @@ const ::google::protobuf::Descriptor* ServiceOptions::descriptor() {
 }
 
 const ServiceOptions& ServiceOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 ServiceOptions* ServiceOptions::default_instance_ = NULL;
@@ -6307,7 +6320,8 @@ const ::google::protobuf::Descriptor* MethodOptions::descriptor() {
 }
 
 const MethodOptions& MethodOptions::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 MethodOptions* MethodOptions::default_instance_ = NULL;
@@ -6536,7 +6550,8 @@ const ::google::protobuf::Descriptor* UninterpretedOption_NamePart::descriptor()
 }
 
 const UninterpretedOption_NamePart& UninterpretedOption_NamePart::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 UninterpretedOption_NamePart* UninterpretedOption_NamePart::default_instance_ = NULL;
@@ -6813,7 +6828,8 @@ const ::google::protobuf::Descriptor* UninterpretedOption::descriptor() {
 }
 
 const UninterpretedOption& UninterpretedOption::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 UninterpretedOption* UninterpretedOption::default_instance_ = NULL;
@@ -7283,7 +7299,8 @@ const ::google::protobuf::Descriptor* SourceCodeInfo_Location::descriptor() {
 }
 
 const SourceCodeInfo_Location& SourceCodeInfo_Location::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 SourceCodeInfo_Location* SourceCodeInfo_Location::default_instance_ = NULL;
@@ -7570,7 +7587,8 @@ const ::google::protobuf::Descriptor* SourceCodeInfo::descriptor() {
 }
 
 const SourceCodeInfo& SourceCodeInfo::default_instance() {
-  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();  return *default_instance_;
+  if (default_instance_ == NULL) protobuf_AddDesc_google_2fprotobuf_2fdescriptor_2eproto();
+  return *default_instance_;
 }
 
 SourceCodeInfo* SourceCodeInfo::default_instance_ = NULL;
diff --git a/third_party/protobuf/src/google/protobuf/stubs/once.cc b/third_party/protobuf/src/google/protobuf/stubs/once.cc
index 5b7af9c..1e24b85 100644
--- a/third_party/protobuf/src/google/protobuf/stubs/once.cc
+++ b/third_party/protobuf/src/google/protobuf/stubs/once.cc
@@ -35,54 +35,65 @@
 // This header is intended to be included only by internal .cc files and
 // generated .pb.cc files.  Users should not use this directly.
 
+#include <google/protobuf/stubs/once.h>
+
+#ifndef GOOGLE_PROTOBUF_NO_THREAD_SAFETY
+
 #ifdef _WIN32
 #include <windows.h>
+#else
+#include <sched.h>
 #endif
 
-#include <google/protobuf/stubs/once.h>
+#include <google/protobuf/stubs/atomicops.h>
 
 namespace google {
 namespace protobuf {
 
-#ifdef _WIN32
-
-struct ProtobufOnceInternal {
-  ProtobufOnceInternal() {
-    InitializeCriticalSection(&critical_section);
-  }
-  ~ProtobufOnceInternal() {
-    DeleteCriticalSection(&critical_section);
-  }
-  CRITICAL_SECTION critical_section;
-};
-
-ProtobufOnceType::~ProtobufOnceType()
-{
-  delete internal_;
-  internal_ = NULL;
-}
+namespace {
 
-ProtobufOnceType::ProtobufOnceType() {
-  // internal_ may be non-NULL if Init() was already called.
-  if (internal_ == NULL) internal_ = new ProtobufOnceInternal;
+void SchedYield() {
+#ifdef _WIN32
+  Sleep(0);
+#else  // POSIX
+  sched_yield();
+#endif
 }
 
-void ProtobufOnceType::Init(void (*init_func)()) {
-  // internal_ may be NULL if we're still in dynamic initialization and the
-  // constructor has not been called yet.  As mentioned in once.h, we assume
-  // that the program is still single-threaded at this time, and therefore it
-  // should be safe to initialize internal_ like so.
-  if (internal_ == NULL) internal_ = new ProtobufOnceInternal;
+}  // namespace
 
-  EnterCriticalSection(&internal_->critical_section);
-  if (!initialized_) {
-    init_func();
-    initialized_ = true;
+void GoogleOnceInitImpl(ProtobufOnceType* once, Closure* closure) {
+  internal::AtomicWord state = internal::Acquire_Load(once);
+  // Fast path. The provided closure was already executed.
+  if (state == ONCE_STATE_DONE) {
+    return;
+  }
+  // The closure execution did not complete yet. The once object can be in one
+  // of the two following states:
+  //   - UNINITIALIZED: We are the first thread calling this function.
+  //   - EXECUTING_CLOSURE: Another thread is already executing the closure.
+  //
+  // First, try to change the state from UNINITIALIZED to EXECUTING_CLOSURE
+  // atomically.
+  state = internal::Acquire_CompareAndSwap(
+      once, ONCE_STATE_UNINITIALIZED, ONCE_STATE_EXECUTING_CLOSURE);
+  if (state == ONCE_STATE_UNINITIALIZED) {
+    // We are the first thread to call this function, so we have to call the
+    // closure.
+    closure->Run();
+    internal::Release_Store(once, ONCE_STATE_DONE);
+  } else {
+    // Another thread has already started executing the closure. We need to
+    // wait until it completes the initialization.
+    while (state == ONCE_STATE_EXECUTING_CLOSURE) {
+      // Note that futex() could be used here on Linux as an improvement.
+      SchedYield();
+      state = internal::Acquire_Load(once);
+    }
   }
-  LeaveCriticalSection(&internal_->critical_section);
 }
 
-#endif
-
 }  // namespace protobuf
 }  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_NO_THREAD_SAFETY
diff --git a/third_party/protobuf/src/google/protobuf/stubs/once.h b/third_party/protobuf/src/google/protobuf/stubs/once.h
index 0dee407..c8cbe24 100644
--- a/third_party/protobuf/src/google/protobuf/stubs/once.h
+++ b/third_party/protobuf/src/google/protobuf/stubs/once.h
@@ -37,16 +37,22 @@
 //
 // This is basically a portable version of pthread_once().
 //
-// This header declares three things:
+// This header declares:
 // * A type called ProtobufOnceType.
 // * A macro GOOGLE_PROTOBUF_DECLARE_ONCE() which declares a variable of type
 //   ProtobufOnceType.  This is the only legal way to declare such a variable.
-//   The macro may only be used at the global scope (you cannot create local
-//   or class member variables of this type).
-// * A function GogoleOnceInit(ProtobufOnceType* once, void (*init_func)()).
+//   The macro may only be used at the global scope (you cannot create local or
+//   class member variables of this type).
+// * A function GoogleOnceInit(ProtobufOnceType* once, void (*init_func)()).
 //   This function, when invoked multiple times given the same ProtobufOnceType
 //   object, will invoke init_func on the first call only, and will make sure
 //   none of the calls return before that first call to init_func has finished.
+// * The user can provide a parameter which GoogleOnceInit() forwards to the
+//   user-provided function when it is called. Usage example:
+//     int a = 10;
+//     GoogleOnceInit(&my_once, &MyFunctionExpectingIntArgument, &a);
+// * This implementation guarantees that ProtobufOnceType is a POD (i.e. no
+//   static initializer generated).
 //
 // This implements a way to perform lazy initialization.  It's more efficient
 // than using mutexes as no lock is needed if initialization has already
@@ -72,50 +78,68 @@
 #ifndef GOOGLE_PROTOBUF_STUBS_ONCE_H__
 #define GOOGLE_PROTOBUF_STUBS_ONCE_H__
 
+#include <google/protobuf/stubs/atomicops.h>
 #include <google/protobuf/stubs/common.h>
 
-#ifndef _WIN32
-#include <pthread.h>
-#endif
-
 namespace google {
 namespace protobuf {
 
-#ifdef _WIN32
-
-struct ProtobufOnceInternal;
+#ifdef GOOGLE_PROTOBUF_NO_THREAD_SAFETY
 
-struct LIBPROTOBUF_EXPORT ProtobufOnceType {
-  ProtobufOnceType();
-  ~ProtobufOnceType();
-  void Init(void (*init_func)());
-
-  volatile bool initialized_;
-  ProtobufOnceInternal* internal_;
-};
+typedef bool ProtobufOnceType;
 
-#define GOOGLE_PROTOBUF_DECLARE_ONCE(NAME)                    \
-  ::google::protobuf::ProtobufOnceType NAME
+#define GOOGLE_PROTOBUF_ONCE_INIT false
 
 inline void GoogleOnceInit(ProtobufOnceType* once, void (*init_func)()) {
-  // Note:  Double-checked locking is safe on x86.
-  if (!once->initialized_) {
-    once->Init(init_func);
+  if (!*once) {
+    *once = true;
+    init_func();
+  }
+}
+
+template <typename Arg>
+inline void GoogleOnceInit(ProtobufOnceType* once, void (*init_func)(Arg),
+    Arg arg) {
+  if (!*once) {
+    *once = true;
+    init_func(arg);
   }
 }
 
 #else
 
-typedef pthread_once_t ProtobufOnceType;
+enum {
+  ONCE_STATE_UNINITIALIZED = 0,
+  ONCE_STATE_EXECUTING_CLOSURE = 1,
+  ONCE_STATE_DONE = 2
+};
 
-#define GOOGLE_PROTOBUF_DECLARE_ONCE(NAME)                    \
-  pthread_once_t NAME = PTHREAD_ONCE_INIT
+typedef internal::AtomicWord ProtobufOnceType;
+
+#define GOOGLE_PROTOBUF_ONCE_INIT ::google::protobuf::ONCE_STATE_UNINITIALIZED
+
+void GoogleOnceInitImpl(ProtobufOnceType* once, Closure* closure);
 
 inline void GoogleOnceInit(ProtobufOnceType* once, void (*init_func)()) {
-  pthread_once(once, init_func);
+  if (internal::Acquire_Load(once) != ONCE_STATE_DONE) {
+    internal::FunctionClosure0 func(init_func, false);
+    GoogleOnceInitImpl(once, &func);
+  }
 }
 
-#endif
+template <typename Arg>
+inline void GoogleOnceInit(ProtobufOnceType* once, void (*init_func)(Arg*),
+    Arg* arg) {
+  if (internal::Acquire_Load(once) != ONCE_STATE_DONE) {
+    internal::FunctionClosure1<Arg*> func(init_func, false, arg);
+    GoogleOnceInitImpl(once, &func);
+  }
+}
+
+#endif  // GOOGLE_PROTOBUF_NO_THREAD_SAFETY
+
+#define GOOGLE_PROTOBUF_DECLARE_ONCE(NAME) \
+  ::google::protobuf::ProtobufOnceType NAME = GOOGLE_PROTOBUF_ONCE_INIT
 
 }  // namespace protobuf
 }  // namespace google