First commit of lite code - more to come

.gitignore

@@ -8,6 +8,8 @@ src/ProtocolBuffers/obj/
 src/ProtocolBuffers/objCF
 src/ProtocolBuffers.Test/bin/
 src/ProtocolBuffers.Test/obj/
+src/ProtocolBuffersLite.Test/bin/
+src/ProtocolBuffersLite.Test/obj/
 src/ProtoBench/bin/
 src/ProtoBench/obj/
 src/ProtoDump/bin/
@@ -34,4 +36,4 @@ _ReSharper.*
 mono/TestResult.xml
 mono/.libs
 mono/*.exe
-mono/*.dll
\ No newline at end of file
+mono/*.dll

protos/extest/unittest_extras_full.proto

+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestExtrasFullProtoFile";
+
+package protobuf_unittest_extra;
+
+option optimize_for = CODE_SIZE;
+
+option java_package = "com.google.protobuf";
+
+message TestInteropPerson {
+  required string name = 1;
+  required int32 id = 2;
+  optional string email = 3;
+  repeated int32 codes = 10 [packed=true];
+
+  enum PhoneType {
+    MOBILE = 0;
+    HOME = 1;
+    WORK = 2;
+  }
+
+  message PhoneNumber {
+    required string number = 1;
+    optional PhoneType type = 2 [default = HOME];
+  }
+
+  repeated PhoneNumber phone = 4;
+  
+  repeated group Addresses = 5 {
+    required string address = 1;
+    optional string address2 = 2;
+    required string city = 3;
+    required string state = 4;
+    required fixed32 zip = 5;
+  }
+
+  extensions 100 to 199;
+}
+
+message  TestInteropEmployeeId {
+  required string number = 1;
+}
+  
+extend TestInteropPerson {
+  required TestInteropEmployeeId employee_id = 126;
+}
+
+message TestMissingFieldsA {
+  required string name = 1;
+  required int32 id = 2;
+  optional string email = 3;
+  
+  message SubA {
+    required int32 count = 5;
+    repeated string values = 6;
+  }
+  optional SubA testA = 11;
+}
+
+message TestMissingFieldsB {
+  required string name = 1;
+  required int32 id = 2;
+  optional string website = 4;
+  
+  message SubB {
+    repeated string values = 7;
+  }
+  optional SubB testB = 12;
+}

protos/extest/unittest_extras_lite.proto

+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestExtrasLiteProtoFile";
+
+package protobuf_unittest_extra;
+
+option optimize_for = LITE_RUNTIME;
+
+option java_package = "com.google.protobuf";
+
+message TestRequiredLite {
+  required int32 d = 1;
+  required ExtraEnum en = 2 [default = DEFAULT];
+}
+
+enum ExtraEnum {
+  DEFAULT = 10;
+  EXLITE_FOO = 7;
+  EXLITE_BAR = 8;
+  EXLITE_BAZ = 9;
+}
+
+message TestInteropPersonLite {
+  required string name = 1;
+  required int32 id = 2;
+  optional string email = 3;
+  repeated int32 codes = 10 [packed=true];
+
+  enum PhoneType {
+    MOBILE = 0;
+    HOME = 1;
+    WORK = 2;
+  }
+
+  message PhoneNumber {
+    required string number = 1;
+    optional PhoneType type = 2 [default = HOME];
+  }
+
+  repeated PhoneNumber phone = 4;
+  
+  repeated group Addresses = 5 {
+    required string address = 1;
+    optional string address2 = 2;
+    required string city = 3;
+    required string state = 4;
+    required fixed32 zip = 5;
+  }
+
+  extensions 100 to 199;
+}
+
+message  TestInteropEmployeeIdLite {
+  required string number = 1;
+}
+  
+extend TestInteropPersonLite {
+  required TestInteropEmployeeIdLite employee_id_lite = 126;
+}

protos/google/protobuf/descriptor.proto

@@ -247,13 +247,31 @@ message FileOptions {
 
   // Generated classes can be optimized for speed or code size.
   enum OptimizeMode {
-    SPEED = 1;      // Generate complete code for parsing, serialization, etc.
-    CODE_SIZE = 2;  // Use ReflectionOps to implement these methods.
+    SPEED = 1;        // Generate complete code for parsing, serialization,
+                      // etc.
+    CODE_SIZE = 2;    // Use ReflectionOps to implement these methods.
+    LITE_RUNTIME = 3; // Generate code using MessageLite and the lite runtime.
   }
   optional OptimizeMode optimize_for = 9 [default=SPEED];
 
 
 
+
+  // Should generic services be generated in each language?  "Generic" services
+  // are not specific to any particular RPC system.  They are generated by the
+  // main code generators in each language (without additional plugins).
+  // Generic services were the only kind of service generation supported by
+  // early versions of proto2.
+  //
+  // Generic services are now considered deprecated in favor of using plugins
+  // that generate code specific to your particular RPC system.  If you are
+  // using such a plugin, set these to false.  In the future, we may change
+  // the default to false, so if you explicitly want generic services, you
+  // should explicitly set these to true.
+  optional bool cc_generic_services = 16 [default=true];
+  optional bool java_generic_services = 17 [default=true];
+  optional bool py_generic_services = 18 [default=true];
+
   // The parser stores options it doesn't recognize here. See above.
   repeated UninterpretedOption uninterpreted_option = 999;
 
@@ -282,6 +300,11 @@ message MessageOptions {
   // the protocol compiler.
   optional bool message_set_wire_format = 1 [default=false];
 
+  // Disables the generation of the standard "descriptor()" accessor, which can
+  // conflict with a field of the same name.  This is meant to make migration
+  // from proto1 easier; new code should avoid fields named "descriptor".
+  optional bool no_standard_descriptor_accessor = 2 [default=false];
+
   // The parser stores options it doesn't recognize here. See above.
   repeated UninterpretedOption uninterpreted_option = 999;
 
@@ -294,8 +317,11 @@ message FieldOptions {
   // representation of the field than it normally would.  See the specific
   // options below.  This option is not yet implemented in the open source
   // release -- sorry, we'll try to include it in a future version!
-  optional CType ctype = 1;
+  optional CType ctype = 1 [default = STRING];
   enum CType {
+    // Default mode.
+    STRING = 0;
+
     CORD = 1;
 
     STRING_PIECE = 2;
@@ -306,12 +332,13 @@ message FieldOptions {
   // a single length-delimited blob.
   optional bool packed = 2;
 
+
   // Is this field deprecated?
   // Depending on the target platform, this can emit Deprecated annotations
   // for accessors, or it will be completely ignored; in the very least, this
   // is a formalization for deprecating fields.
   optional bool deprecated = 3 [default=false];
-  
+
   // EXPERIMENTAL.  DO NOT USE.
   // For "map" fields, the name of the field in the enclosed type that
   // is the key for this map.  For example, suppose we have:
@@ -334,6 +361,7 @@ message FieldOptions {
 }
 
 message EnumOptions {
+
   // The parser stores options it doesn't recognize here. See above.
   repeated UninterpretedOption uninterpreted_option = 999;
 

protos/google/protobuf/unittest.proto

@@ -161,6 +161,10 @@ message TestAllTypes {
   optional string default_cord = 85 [ctype=CORD,default="123"];
 }
 
+message TestDeprecatedFields {
+  optional int32 deprecated_int32 = 1 [deprecated=true];
+}
+
 // Define these after TestAllTypes to make sure the compiler can handle
 // that.
 message ForeignMessage {
@@ -275,6 +279,14 @@ extend TestAllExtensions {
   optional string default_cord_extension = 85 [ctype=CORD, default="123"];
 }
 
+message TestNestedExtension {
+  extend TestAllExtensions {
+    // Check for bug where string extensions declared in tested scope did not
+    // compile.
+    optional string test = 1002 [default="test"];
+  }
+}
+
 // We have separate messages for testing required fields because it's
 // annoying to have to fill in required fields in TestProto in order to
 // do anything with it.  Note that we don't need to test every type of
@@ -346,6 +358,12 @@ message TestEmptyMessageWithExtensions {
   extensions 1 to max;
 }
 
+message TestMultipleExtensionRanges {
+  extensions 42;
+  extensions 4143 to 4243;
+  extensions 65536 to max;
+}
+
 // Test that really large tag numbers don't break anything.
 message TestReallyLargeTagNumber {
   // The largest possible tag number is 2^28 - 1, since the wire format uses
@@ -370,13 +388,14 @@ message TestMutualRecursionB {
 }
 
 // Test that groups have disjoint field numbers from their siblings and
-// parents.  This is NOT possible in proto1; only proto2.  When outputting
-// proto1, the dup fields should be dropped.
-message TestDupFieldNumber {
-  optional int32 a = 1;
-  optional group Foo = 2 { optional int32 a = 1; }
-  optional group Bar = 3 { optional int32 a = 1; }
-}
+// parents.  This is NOT possible in proto1; only proto2.  When attempting
+// to compile with proto1, this will emit an error; so we only include it
+// in protobuf_unittest_proto.
+message TestDupFieldNumber {                        // NO_PROTO1
+  optional int32 a = 1;                             // NO_PROTO1
+  optional group Foo = 2 { optional int32 a = 1; }  // NO_PROTO1
+  optional group Bar = 3 { optional int32 a = 1; }  // NO_PROTO1
+}                                                   // NO_PROTO1
 
 
 // Needed for a Python test.
@@ -456,8 +475,37 @@ message TestExtremeDefaultValues {
   // the UTF-8 text directly into this text file rather than escape it, but
   // lots of people use editors that would be confused by this.)
   optional string utf8_string = 6 [default = "\341\210\264"];
+
+  // Tests for single-precision floating-point values.
+  optional float zero_float = 7 [default = 0];
+  optional float one_float = 8 [default = 1];
+  optional float small_float = 9 [default = 1.5];
+  optional float negative_one_float = 10 [default = -1];
+  optional float negative_float = 11 [default = -1.5];
+  // Using exponents
+  optional float large_float = 12 [default = 2E8];
+  optional float small_negative_float = 13 [default = -8e-28];
+
+  // Text for nonfinite floating-point values.
+  optional double inf_double = 14 [default = inf];
+  optional double neg_inf_double = 15 [default = -inf];
+  optional double nan_double = 16 [default = nan];
+  optional float inf_float = 17 [default = inf];
+  optional float neg_inf_float = 18 [default = -inf];
+  optional float nan_float = 19 [default = nan];
 }
 
+// Test String and Bytes: string is for valid UTF-8 strings
+message OneString {
+  optional string data = 1;
+}
+
+message OneBytes {
+  optional bytes data = 1;
+}
+
+// Test messages for packed fields
+
 message TestPackedTypes {
   repeated    int32 packed_int32    =  90 [packed = true];
   repeated    int64 packed_int64    =  91 [packed = true];
@@ -475,6 +523,25 @@ message TestPackedTypes {
   repeated ForeignEnum packed_enum  = 103 [packed = true];
 }
 
+// A message with the same fields as TestPackedTypes, but without packing. Used
+// to test packed <-> unpacked wire compatibility.
+message TestUnpackedTypes {
+  repeated    int32 unpacked_int32    =  90 [packed = false];
+  repeated    int64 unpacked_int64    =  91 [packed = false];
+  repeated   uint32 unpacked_uint32   =  92 [packed = false];
+  repeated   uint64 unpacked_uint64   =  93 [packed = false];
+  repeated   sint32 unpacked_sint32   =  94 [packed = false];
+  repeated   sint64 unpacked_sint64   =  95 [packed = false];
+  repeated  fixed32 unpacked_fixed32  =  96 [packed = false];
+  repeated  fixed64 unpacked_fixed64  =  97 [packed = false];
+  repeated sfixed32 unpacked_sfixed32 =  98 [packed = false];
+  repeated sfixed64 unpacked_sfixed64 =  99 [packed = false];
+  repeated    float unpacked_float    = 100 [packed = false];
+  repeated   double unpacked_double   = 101 [packed = false];
+  repeated     bool unpacked_bool     = 102 [packed = false];
+  repeated ForeignEnum unpacked_enum  = 103 [packed = false];
+}
+
 message TestPackedExtensions {
   extensions 1 to max;
 }
@@ -496,6 +563,47 @@ extend TestPackedExtensions {
   repeated ForeignEnum packed_enum_extension  = 103 [packed = true];
 }
 
+// Used by ExtensionSetTest/DynamicExtensions.  The test actually builds
+// a set of extensions to TestAllExtensions dynamically, based on the fields
+// of this message type.
+message TestDynamicExtensions {
+  enum DynamicEnumType {
+    DYNAMIC_FOO = 2200;
+    DYNAMIC_BAR = 2201;
+    DYNAMIC_BAZ = 2202;
+  }
+  message DynamicMessageType {
+    optional int32 dynamic_field = 2100;
+  }
+
+  optional fixed32 scalar_extension = 2000;
+  optional ForeignEnum enum_extension = 2001;
+  optional DynamicEnumType dynamic_enum_extension = 2002;
+
+  optional ForeignMessage message_extension = 2003;
+  optional DynamicMessageType dynamic_message_extension = 2004;
+
+  repeated string repeated_extension = 2005;
+  repeated sint32 packed_extension = 2006 [packed = true];
+}
+
+message TestRepeatedScalarDifferentTagSizes {
+  // Parsing repeated fixed size values used to fail. This message needs to be
+  // used in order to get a tag of the right size; all of the repeated fields
+  // in TestAllTypes didn't trigger the check.
+  repeated fixed32 repeated_fixed32 = 12;
+  // Check for a varint type, just for good measure.
+  repeated int32   repeated_int32   = 13;
+
+  // These have two-byte tags.
+  repeated fixed64 repeated_fixed64 = 2046;
+  repeated int64   repeated_int64   = 2047;
+
+  // Three byte tags.
+  repeated float   repeated_float   = 262142;
+  repeated uint64  repeated_uint64  = 262143;
+}
+
 // Test that RPC services work.
 message FooRequest  {}
 message FooResponse {}

protos/google/protobuf/unittest_custom_options.proto

@@ -72,7 +72,9 @@ extend google.protobuf.EnumOptions {
   optional sfixed32 enum_opt1 = 7753576;
 }
 
-// TODO(benjy): Test options on enum values when the parser supports them.
+extend google.protobuf.EnumValueOptions {
+  optional int32 enum_value_opt1 = 1560678;
+}
 
 extend google.protobuf.ServiceOptions {
   optional sint64 service_opt1 = 7887650;
@@ -101,7 +103,7 @@ message TestMessageWithCustomOptions {
     option (enum_opt1) = -789;
 
     ANENUM_VAL1 = 1;
-    ANENUM_VAL2 = 2;
+    ANENUM_VAL2 = 2 [(enum_value_opt1) = 123];
   }
 }
 
@@ -208,6 +210,8 @@ message SettingRealsFromNegativeInts {
 
 message ComplexOptionType1 {
   optional int32 foo = 1;
+  optional int32 foo2 = 2;
+  optional int32 foo3 = 3;
 
   extensions 100 to max;
 }

protos/google/protobuf/unittest_empty.proto

+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestEmptyProtoFile";
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// This file intentionally left blank.  (At one point this wouldn't compile
+// correctly.)
+

protos/google/protobuf/unittest_import_lite.proto

+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestImportLiteProtoFile";
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//
+// This is like unittest_import.proto but with optimize_for = LITE_RUNTIME.
+
+package protobuf_unittest_import;
+
+option optimize_for = LITE_RUNTIME;
+
+option java_package = "com.google.protobuf";
+
+message ImportMessageLite {
+  optional int32 d = 1;
+}
+
+enum ImportEnumLite {
+  IMPORT_LITE_FOO = 7;
+  IMPORT_LITE_BAR = 8;
+  IMPORT_LITE_BAZ = 9;
+}

protos/google/protobuf/unittest_lite_imports_nonlite.proto

+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestLiteImportNonLiteProtoFile";
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//
+// Tests that a "lite" message can import a regular message.
+
+package protobuf_unittest;
+
+import "google/protobuf/unittest.proto";
+
+option optimize_for = LITE_RUNTIME;
+
+message TestLiteImportsNonlite {
+  optional TestAllTypes message = 1;
+}

protos/google/protobuf/unittest_no_generic_services.proto

+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos.NoGenericService";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestNoGenericServicesProtoFile";
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+
+package google.protobuf.no_generic_services_test;
+
+option cc_generic_services = false;
+option java_generic_services = false;
+option py_generic_services = false;
+
+message TestMessage {
+  optional int32 a = 1;
+  extensions 1000 to max;
+}
+
+enum TestEnum {
+  FOO = 1;
+}
+
+extend TestMessage {
+  optional int32 test_extension = 1000;
+}
+
+service TestService {
+  rpc Foo(TestMessage) returns(TestMessage);
+}

src/AddressBook/AddressBookProtos.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtoGen.Test/ProtoGen.Test.csproj

@@ -78,7 +78,7 @@
   <ItemGroup>
     <Reference Include="nunit.framework, Version=2.2.8.0, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\lib\nunit.framework.dll</HintPath>
+      <HintPath>..\..\lib\NUnit 2.2.8.0\nunit.framework.dll</HintPath>
     </Reference>
     <Reference Include="Rhino.Mocks, Version=3.5.0.2, Culture=neutral, PublicKeyToken=0b3305902db7183f, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>

src/ProtoGen/EnumFieldGenerator.cs

@@ -88,10 +88,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
       // TODO(jonskeet): Make a more efficient way of doing this
       writer.WriteLine("int rawValue = input.ReadEnum();");
       writer.WriteLine("if (!global::System.Enum.IsDefined(typeof({0}), rawValue)) {{", TypeName);
-      writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
-      writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
-      writer.WriteLine("  }");
-      writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+      if (!UseLiteRuntime) {
+        writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
+        writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
+        writer.WriteLine("  }");
+        writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+      }
       writer.WriteLine("} else {");
       writer.WriteLine("  {0} = ({1}) rawValue;", PropertyName, TypeName);
       writer.WriteLine("}");
@@ -106,7 +108,19 @@ namespace Google.ProtocolBuffers.ProtoGen {
     public void GenerateSerializedSizeCode(TextGenerator writer) {
       writer.WriteLine("if (Has{0}) {{", PropertyName);
       writer.WriteLine("  size += pb::CodedOutputStream.ComputeEnumSize({0}, (int) {1});", Number, PropertyName);
-      writer.WriteLine("}");    
+      writer.WriteLine("}");
+    }
+
+    public override void WriteHash(TextGenerator writer) {
+      writer.WriteLine("if (has{0}) hash ^= {1}_.GetHashCode();", PropertyName, Name);
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+      writer.WriteLine("if (has{0} != other.has{0} || (has{0} && !{1}_.Equals(other.{1}_))) return false;", PropertyName, Name);
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+      writer.WriteLine("PrintField(\"{0}\", has{1}, {2}_, writer);", Descriptor.Name, PropertyName, Name);
     }
   }
 }

src/ProtoGen/ExtensionGenerator.cs

@@ -32,16 +32,20 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
+using System;
+using System.Globalization;
 using Google.ProtocolBuffers.Descriptors;
 
 namespace Google.ProtocolBuffers.ProtoGen {
-  internal class ExtensionGenerator : SourceGeneratorBase<FieldDescriptor>, ISourceGenerator {
+  internal class ExtensionGenerator : FieldGeneratorBase, ISourceGenerator {
 
+    private readonly string extends;
     private readonly string scope;
     private readonly string type;
     private readonly string name;
 
-    internal ExtensionGenerator(FieldDescriptor descriptor) : base(descriptor) {
+    internal ExtensionGenerator(FieldDescriptor descriptor)
+      : base(descriptor) {
       if (Descriptor.ExtensionScope != null) {
         scope = GetClassName(Descriptor.ExtensionScope);
       } else {
@@ -58,14 +62,24 @@ namespace Google.ProtocolBuffers.ProtoGen {
           type = DescriptorUtil.GetMappedTypeName(Descriptor.MappedType);
           break;
       }
+      extends = GetClassName(Descriptor.ContainingType);
       name = Descriptor.CSharpOptions.PropertyName;
     }
 
     public void Generate(TextGenerator writer) {
-      writer.WriteLine ("public const int {0} = {1};", GetFieldConstantName(Descriptor), Descriptor.FieldNumber);
-      if (Descriptor.IsRepeated) {
-        if (!Descriptor.IsCLSCompliant && Descriptor.File.CSharpOptions.ClsCompliance)
-          {
+      writer.WriteLine("public const int {0} = {1};", GetFieldConstantName(Descriptor), Descriptor.FieldNumber);
+
+      if (UseLiteRuntime) {
+        if (Descriptor.MappedType == MappedType.Message && Descriptor.MessageType.Options.MessageSetWireFormat) {
+          throw new ArgumentException("option message_set_wire_format = true; is not supported in Lite runtime extensions.");
+        }
+        if (!Descriptor.IsCLSCompliant && Descriptor.File.CSharpOptions.ClsCompliance) {
+          writer.WriteLine("[global::System.CLSCompliant(false)]");
+        }
+        writer.WriteLine("{0} static pb::{4}<{1}, {2}> {3};", ClassAccessLevel, extends, type, name,
+          Descriptor.IsRepeated ? "GeneratedRepeatExtensionLite" : "GeneratedExtensionLite");
+      } else if (Descriptor.IsRepeated) {
+        if (!Descriptor.IsCLSCompliant && Descriptor.File.CSharpOptions.ClsCompliance) {
           writer.WriteLine("[global::System.CLSCompliant(false)]");
         }
         writer.WriteLine("{0} static pb::GeneratedExtensionBase<scg::IList<{1}>> {2};", ClassAccessLevel, type, name);
@@ -78,7 +92,27 @@ namespace Google.ProtocolBuffers.ProtoGen {
     }
 
     internal void GenerateStaticVariableInitializers(TextGenerator writer) {
-      if (Descriptor.IsRepeated) {
+      if (UseLiteRuntime) {
+        writer.WriteLine("{0}.{1} = ", scope, name);
+        writer.Indent();
+        writer.WriteLine("new pb::{0}<{1}, {2}>(", Descriptor.IsRepeated ? "GeneratedRepeatExtensionLite" : "GeneratedExtensionLite", extends, type);
+        writer.Indent();
+        writer.WriteLine("\"{0}\",", Descriptor.FullName);
+        writer.WriteLine("{0}.DefaultInstance,", extends);
+        if(!Descriptor.IsRepeated)
+          writer.WriteLine("{0},", Descriptor.HasDefaultValue ? DefaultValue : IsNullableType ? "null" : "default(" + type + ")");
+        writer.WriteLine("{0},", (Descriptor.MappedType == MappedType.Message) ? type + ".DefaultInstance" : "null");
+        writer.WriteLine("{0},", (Descriptor.MappedType == MappedType.Enum) ? "new EnumLiteMap<" + type + ">()" : "null");
+        writer.WriteLine("{0}.{1}FieldNumber,", scope, name);
+        writer.Write("pbd::FieldType.{0}", Descriptor.FieldType);
+        if (Descriptor.IsRepeated) {
+          writer.WriteLine(",");
+          writer.Write(Descriptor.IsPacked ? "true" : "false");
+        }
+        writer.Outdent();
+        writer.WriteLine(");");
+        writer.Outdent();
+      } else if (Descriptor.IsRepeated) {
         writer.WriteLine("{0}.{1} = pb::GeneratedRepeatExtension<{2}>.CreateInstance({0}.Descriptor.Extensions[{3}]);", scope, name, type, Descriptor.Index);
       } else {
         writer.WriteLine("{0}.{1} = pb::GeneratedSingleExtension<{2}>.CreateInstance({0}.Descriptor.Extensions[{3}]);", scope, name, type, Descriptor.Index);
@@ -88,5 +122,14 @@ namespace Google.ProtocolBuffers.ProtoGen {
     internal void GenerateExtensionRegistrationCode(TextGenerator writer) {
       writer.WriteLine("registry.Add({0}.{1});", scope, name);
     }
+
+    public override void WriteHash(TextGenerator writer) {
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+    }
   }
 }

src/ProtoGen/FieldGeneratorBase.cs

@@ -42,6 +42,10 @@ namespace Google.ProtocolBuffers.ProtoGen {
         : base(descriptor) {
     }
 
+    public abstract void WriteHash(TextGenerator writer);
+    public abstract void WriteEquals(TextGenerator writer);
+    public abstract void WriteToString(TextGenerator writer);
+
     private static bool AllPrintableAscii(string text) {
       foreach (char c in text) {
         if (c < 0x20 || c > 0x7e) {
@@ -51,6 +55,7 @@ namespace Google.ProtocolBuffers.ProtoGen {
       return true;
     }
 
+    /// <remarks>Copy exists in ExtensionGenerator.cs</remarks>
     protected string DefaultValue {
       get {
         string suffix = "";
@@ -72,11 +77,30 @@ namespace Google.ProtocolBuffers.ProtoGen {
           case FieldType.UInt32:
           case FieldType.UInt64:
           case FieldType.Fixed32:
-          case FieldType.Fixed64:
+          case FieldType.Fixed64: 
+          {
             // The simple Object.ToString converts using the current culture.
             // We want to always use the invariant culture so it's predictable.
             IConvertible value = (IConvertible) Descriptor.DefaultValue;
+            //a few things that must be handled explicitly
+            if (Descriptor.FieldType == FieldType.Double && value is double) {
+              if (double.IsNaN((double) value))
+                return "double.NaN";
+              if (double.IsPositiveInfinity((double) value))
+                return "double.PositiveInfinity";
+              if (double.IsNegativeInfinity((double) value))
+                return "double.NegativeInfinity";
+            }
+            else if (Descriptor.FieldType == FieldType.Float && value is float) {
+              if (float.IsNaN((float)value))
+                return "float.NaN";
+              if (float.IsPositiveInfinity((float)value))
+                return "float.PositiveInfinity";
+              if (float.IsNegativeInfinity((float)value))
+                return "float.NegativeInfinity";
+            }
             return value.ToString(CultureInfo.InvariantCulture) + suffix;
+          }
           case FieldType.Bool:
             return (bool) Descriptor.DefaultValue ? "true" : "false";
 
@@ -84,6 +108,10 @@ namespace Google.ProtocolBuffers.ProtoGen {
             if (!Descriptor.HasDefaultValue) {
               return "pb::ByteString.Empty";
             }
+            if (UseLiteRuntime && Descriptor.DefaultValue is ByteString) {
+              string temp = Convert.ToBase64String(((ByteString)Descriptor.DefaultValue).ToByteArray());
+              return String.Format("ByteString.FromBase64(\"{0}\")", temp);
+            }
             return string.Format("(pb::ByteString) {0}.Descriptor.Fields[{1}].DefaultValue", GetClassName(Descriptor.ContainingType), Descriptor.Index);
           case FieldType.String:
             if (AllPrintableAscii(Descriptor.Proto.DefaultValue)) {
@@ -95,6 +123,10 @@ namespace Google.ProtocolBuffers.ProtoGen {
                   .Replace("\"", "\\\"")
                   + "\"";
             }
+            if (UseLiteRuntime && Descriptor.DefaultValue is String) {
+              string temp = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes((String)Descriptor.DefaultValue));
+              return String.Format("ByteString.FromBase64(\"{0}\").ToStringUtf8()", temp);
+            }
             return string.Format("(string) {0}.Descriptor.Fields[{1}].DefaultValue", GetClassName(Descriptor.ContainingType), Descriptor.Index);
           case FieldType.Enum:
             return TypeName + "." + ((EnumValueDescriptor) Descriptor.DefaultValue).Name;

src/ProtoGen/Helpers.cs

@@ -38,11 +38,5 @@ namespace Google.ProtocolBuffers.ProtoGen {
   /// Helpers to resolve class names etc.
   /// </summary>
   internal static class Helpers {
-    internal static void WriteNamespaces(TextGenerator writer) {
-      writer.WriteLine("using pb = global::Google.ProtocolBuffers;");
-      writer.WriteLine("using pbc = global::Google.ProtocolBuffers.Collections;");
-      writer.WriteLine("using pbd = global::Google.ProtocolBuffers.Descriptors;");
-      writer.WriteLine("using scg = global::System.Collections.Generic;");
-    }
   }
 }

src/ProtoGen/IFieldSourceGenerator.cs

@@ -41,5 +41,9 @@ namespace Google.ProtocolBuffers.ProtoGen {
     void GenerateParsingCode(TextGenerator writer);
     void GenerateSerializationCode(TextGenerator writer);
     void GenerateSerializedSizeCode(TextGenerator writer);
+
+    void WriteHash(TextGenerator writer);
+    void WriteEquals(TextGenerator writer);
+    void WriteToString(TextGenerator writer);
   }
 }

src/ProtoGen/MessageFieldGenerator.cs

@@ -125,5 +125,18 @@ namespace Google.ProtocolBuffers.ProtoGen {
           MessageOrGroup, Number, PropertyName);
       writer.WriteLine("}");
     }
+
+    public override void WriteHash(TextGenerator writer) {
+      writer.WriteLine("if (has{0}) hash ^= {1}_.GetHashCode();", PropertyName, Name);
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+      writer.WriteLine("if (has{0} != other.has{0} || (has{0} && !{1}_.Equals(other.{1}_))) return false;", PropertyName, Name);
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+      writer.WriteLine("PrintField(\"{2}\", has{0}, {1}_, writer);", PropertyName, Name,
+        Descriptor.FieldType == FieldType.Group ? Descriptor.MessageType.Name : Descriptor.Name);
+    }
   }
 }

src/ProtoGen/PrimitiveFieldGenerator.cs

@@ -103,5 +103,17 @@ namespace Google.ProtocolBuffers.ProtoGen {
           CapitalizedTypeName, Number, PropertyName);
       writer.WriteLine("}");
     }
+
+    public override void WriteHash(TextGenerator writer) {
+      writer.WriteLine("if (has{0}) hash ^= {1}_.GetHashCode();", PropertyName, Name);
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+      writer.WriteLine("if (has{0} != other.has{0} || (has{0} && !{1}_.Equals(other.{1}_))) return false;", PropertyName, Name);
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+      writer.WriteLine("PrintField(\"{0}\", has{1}, {2}_, writer);", Descriptor.Name, PropertyName, Name);
+    }
   }
 }

src/ProtoGen/RepeatedEnumFieldGenerator.cs

@@ -43,7 +43,7 @@ namespace Google.ProtocolBuffers.ProtoGen {
     }
 
     public void GenerateMembers(TextGenerator writer) {
-      if (Descriptor.IsPacked && Descriptor.File.Options.OptimizeFor == FileOptions.Types.OptimizeMode.SPEED) {
+      if (Descriptor.IsPacked && OptimizeSpeed) {
         writer.WriteLine("private int {0}MemoizedSerializedSize;", Name);
       }
       writer.WriteLine("private pbc::PopsicleList<{0}> {1}_ = new pbc::PopsicleList<{0}>();", TypeName, Name);
@@ -114,10 +114,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
       // TODO(jonskeet): Make a more efficient way of doing this
       writer.WriteLine("int rawValue = input.ReadEnum();");
       writer.WriteLine("if (!global::System.Enum.IsDefined(typeof({0}), rawValue)) {{", TypeName);
-      writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
-      writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
-      writer.WriteLine("  }");
-      writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+      if (!UseLiteRuntime) {
+        writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
+        writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
+        writer.WriteLine("  }");
+        writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+      }
       writer.WriteLine("} else {");
       writer.WriteLine("  Add{0}(({1}) rawValue);", PropertyName, TypeName);
       writer.WriteLine("}");
@@ -173,5 +175,20 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.Outdent();
       writer.WriteLine("}");
     }
+
+    public override void WriteHash(TextGenerator writer) {
+      writer.WriteLine("foreach({0} i in {1}_)", TypeName, Name);
+      writer.WriteLine("  hash ^= i.GetHashCode();");
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+      writer.WriteLine("if({0}_.Count != other.{0}_.Count) return false;", Name);
+      writer.WriteLine("for(int ix=0; ix < {0}_.Count; ix++)", Name);
+      writer.WriteLine("  if(!{0}_[ix].Equals(other.{0}_[ix])) return false;", Name);
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+      writer.WriteLine("PrintField(\"{0}\", {1}_, writer);", Descriptor.Name, Name);
+    }
   }
 }

src/ProtoGen/RepeatedMessageFieldGenerator.cs

@@ -132,5 +132,22 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("  size += pb::CodedOutputStream.Compute{0}Size({1}, element);", MessageOrGroup, Number);
       writer.WriteLine("}");
     }
+
+    public override void WriteHash(TextGenerator writer) {
+      writer.WriteLine("foreach({0} i in {1}_)", TypeName, Name);
+      writer.WriteLine("  hash ^= i.GetHashCode();");
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+      writer.WriteLine("if({0}_.Count != other.{0}_.Count) return false;", Name);
+      writer.WriteLine("for(int ix=0; ix < {0}_.Count; ix++)", Name);
+      writer.WriteLine("  if(!{0}_[ix].Equals(other.{0}_[ix])) return false;", Name);
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+      writer.WriteLine("PrintField(\"{0}\", {1}_, writer);",
+        Descriptor.FieldType == FieldType.Group ? Descriptor.MessageType.Name : Descriptor.Name, Name);
+    }
+
   }
 }

src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs

@@ -43,7 +43,7 @@ namespace Google.ProtocolBuffers.ProtoGen {
     }
 
     public void GenerateMembers(TextGenerator writer) {
-      if (Descriptor.IsPacked && Descriptor.File.Options.OptimizeFor == FileOptions.Types.OptimizeMode.SPEED) {
+      if (Descriptor.IsPacked && OptimizeSpeed) {
         writer.WriteLine("private int {0}MemoizedSerializedSize;", Name);
       }
       writer.WriteLine("private pbc::PopsicleList<{0}> {1}_ = new pbc::PopsicleList<{0}>();", TypeName, Name);
@@ -168,5 +168,20 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.Outdent();
       writer.WriteLine("}");
     }
+
+    public override void WriteHash(TextGenerator writer) {
+      writer.WriteLine("foreach({0} i in {1}_)", TypeName, Name);
+      writer.WriteLine("  hash ^= i.GetHashCode();");
+    }
+
+    public override void WriteEquals(TextGenerator writer) {
+      writer.WriteLine("if({0}_.Count != other.{0}_.Count) return false;", Name);
+      writer.WriteLine("for(int ix=0; ix < {0}_.Count; ix++)", Name);
+      writer.WriteLine("  if(!{0}_[ix].Equals(other.{0}_[ix])) return false;", Name);
+    }
+
+    public override void WriteToString(TextGenerator writer) {
+      writer.WriteLine("PrintField(\"{0}\", {1}_, writer);", Descriptor.Name, Name);
+    }
   }
 }

src/ProtoGen/SourceGeneratorBase.cs

@@ -40,8 +40,20 @@ namespace Google.ProtocolBuffers.ProtoGen {
 
     private readonly T descriptor;
 
+    protected readonly bool OptimizeSpeed;
+    protected readonly bool OptimizeSize;
+    protected readonly bool UseLiteRuntime;
+    protected readonly string RuntimeSuffix;
+
     protected SourceGeneratorBase(T descriptor) {
       this.descriptor = descriptor;
+
+      OptimizeSize = descriptor.File.Options.OptimizeFor == Google.ProtocolBuffers.DescriptorProtos.FileOptions.Types.OptimizeMode.CODE_SIZE;
+      OptimizeSpeed = descriptor.File.Options.OptimizeFor == Google.ProtocolBuffers.DescriptorProtos.FileOptions.Types.OptimizeMode.SPEED;
+      UseLiteRuntime = descriptor.File.Options.OptimizeFor == Google.ProtocolBuffers.DescriptorProtos.FileOptions.Types.OptimizeMode.LITE_RUNTIME;
+      //Lite runtime uses OptimizeSpeed code branches
+      OptimizeSpeed |= UseLiteRuntime;
+      RuntimeSuffix = UseLiteRuntime ? "Lite" : "";
     }
 
     protected T Descriptor {

src/ProtoGen/UmbrellaClassGenerator.cs

@@ -74,10 +74,6 @@ namespace Google.ProtocolBuffers.ProtoGen {
       return false;
     }
 
-    public string UmbrellaClassName {
-      get { throw new NotImplementedException(); }
-    }
-
     public void Generate(TextGenerator writer) {
       WriteIntroduction(writer);
       WriteExtensionRegistration(writer);
@@ -87,7 +83,11 @@ namespace Google.ProtocolBuffers.ProtoGen {
         new MessageGenerator(message).GenerateStaticVariables(writer);
       }
       writer.WriteLine("#endregion");
-      WriteDescriptor(writer);
+      if (!UseLiteRuntime) {
+        WriteDescriptor(writer);
+      } else {
+        WriteLiteExtensions(writer);
+      }
       // The class declaration either gets closed before or after the children are written.
       if (!Descriptor.CSharpOptions.NestClasses) {
         writer.Outdent();
@@ -113,9 +113,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
     }
 
     private void WriteIntroduction(TextGenerator writer) {
-      writer.WriteLine("// Generated by the protocol buffer compiler.  DO NOT EDIT!");
+      writer.WriteLine("// Generated by {0}.  DO NOT EDIT!", this.GetType().Assembly.FullName);
       writer.WriteLine();
-      Helpers.WriteNamespaces(writer);
+      writer.WriteLine("using pb = global::Google.ProtocolBuffers;");
+      writer.WriteLine("using pbc = global::Google.ProtocolBuffers.Collections;");
+      writer.WriteLine("using pbd = global::Google.ProtocolBuffers.Descriptors;");
+      writer.WriteLine("using scg = global::System.Collections.Generic;");
 
       if (Descriptor.CSharpOptions.Namespace != "") {
         writer.WriteLine("namespace {0} {{", Descriptor.CSharpOptions.Namespace);
@@ -215,5 +218,24 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("#endregion");
       writer.WriteLine();
     }
+
+    private void WriteLiteExtensions(TextGenerator writer) {
+      writer.WriteLine("#region Extensions");
+      writer.WriteLine("internal static readonly object Descriptor;");
+      writer.WriteLine("static {0}() {{", Descriptor.CSharpOptions.UmbrellaClassname);
+      writer.Indent();
+      writer.WriteLine("Descriptor = null;");
+
+      foreach (MessageDescriptor message in Descriptor.MessageTypes) {
+        new MessageGenerator(message).GenerateStaticVariableInitializers(writer);
+      }
+      foreach (FieldDescriptor extension in Descriptor.Extensions) {
+        new ExtensionGenerator(extension).GenerateStaticVariableInitializers(writer);
+      }
+      writer.Outdent();
+      writer.WriteLine("}");
+      writer.WriteLine("#endregion");
+      writer.WriteLine();
+    }
   }
 }

src/ProtocolBuffers.Test/ProtocolBuffers.Test.csproj

@@ -54,37 +54,37 @@
     <WarningLevel>4</WarningLevel>
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
-	<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug_Silverlight2|AnyCPU'">
-		<DebugSymbols>true</DebugSymbols>
-		<DebugType>full</DebugType>
-		<Optimize>false</Optimize>
-		<OutputPath>bin\Debug_Silverlight2\</OutputPath>
-		<DefineConstants>DEBUG;TRACE;SILVERLIGHT2</DefineConstants>
-		<ErrorReport>prompt</ErrorReport>
-		<WarningLevel>4</WarningLevel>
-		<NoStdLib>true</NoStdLib>
-		<CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
-	</PropertyGroup>
-	<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release_Silverlight2|AnyCPU'">
-		<DebugType>pdbonly</DebugType>
-		<Optimize>true</Optimize>
-		<OutputPath>bin\Release_Silverlight2\</OutputPath>
-		<DefineConstants>TRACE;SILVERLIGHT2</DefineConstants>
-		<ErrorReport>prompt</ErrorReport>
-		<WarningLevel>4</WarningLevel>
-		<NoStdLib>true</NoStdLib>
-		<CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
-	</PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug_Silverlight2|AnyCPU'">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug_Silverlight2\</OutputPath>
+    <DefineConstants>DEBUG;TRACE;SILVERLIGHT2</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+    <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release_Silverlight2|AnyCPU'">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release_Silverlight2\</OutputPath>
+    <DefineConstants>TRACE;SILVERLIGHT2</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+    <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
   <ItemGroup>
     <Reference Include="nunit.framework, Version=2.2.8.0, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\lib\nunit.framework.dll</HintPath>
+      <HintPath>..\..\lib\NUnit 2.2.8.0\nunit.framework.dll</HintPath>
     </Reference>
     <Reference Include="Rhino.Mocks, Version=3.5.0.2, Culture=neutral, PublicKeyToken=0b3305902db7183f, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\lib\Rhino.Mocks.dll</HintPath>
     </Reference>
-	  <Reference Include="mscorlib" />
+    <Reference Include="mscorlib" />
     <Reference Include="System" />
     <Reference Include="System.Data" />
     <Reference Include="System.Xml" />
@@ -99,6 +99,7 @@
     <Compile Include="DescriptorsTest.cs" />
     <Compile Include="Descriptors\MessageDescriptorTest.cs" />
     <Compile Include="DynamicMessageTest.cs" />
+    <Compile Include="ExtendableMessageTest.cs" />
     <Compile Include="GeneratedMessageTest.cs" />
     <Compile Include="MessageStreamIteratorTest.cs" />
     <Compile Include="MessageStreamWriterTest.cs" />
@@ -111,8 +112,11 @@
     <Compile Include="TestProtos\UnitTestCSharpOptionsProtoFile.cs" />
     <Compile Include="TestProtos\UnitTestCustomOptionsProtoFile.cs" />
     <Compile Include="TestProtos\UnitTestEmbedOptimizeForProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestEmptyProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestImportLiteProtoFile.cs" />
     <Compile Include="TestProtos\UnitTestImportProtoFile.cs" />
     <Compile Include="TestProtos\UnitTestMessageSetProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestNoGenericServicesProtoFile.cs" />
     <Compile Include="TestProtos\UnitTestOptimizeForProtoFile.cs" />
     <Compile Include="TestProtos\UnitTestProtoFile.cs" />
     <Compile Include="TestUtil.cs" />

src/ProtocolBuffers.Test/ReflectionTester.cs

@@ -213,7 +213,7 @@ namespace Google.ProtocolBuffers {
         ExtensionInfo extension = extensionRegistry[field.ContainingType, field.FieldNumber];
         Assert.IsNotNull(extension);
         Assert.IsNotNull(extension.DefaultInstance);
-        return extension.DefaultInstance.WeakCreateBuilderForType();
+        return (IBuilder)extension.DefaultInstance.WeakCreateBuilderForType();
       }
     }
 

src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtocolBuffers.Test/TestProtos/UnitTestEmptyProtoFile.cs

+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
+
+using pb = global::Google.ProtocolBuffers;
+using pbc = global::Google.ProtocolBuffers.Collections;
+using pbd = global::Google.ProtocolBuffers.Descriptors;
+using scg = global::System.Collections.Generic;
+namespace Google.ProtocolBuffers.TestProtos {
+  
+  public static partial class UnitTestEmptyProtoFile {
+  
+    #region Extension registration
+    public static void RegisterAllExtensions(pb::ExtensionRegistry registry) {
+    }
+    #endregion
+    #region Static variables
+    #endregion
+    #region Descriptor
+    public static pbd::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbd::FileDescriptor descriptor;
+    
+    static UnitTestEmptyProtoFile() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          "CiRnb29nbGUvcHJvdG9idWYvdW5pdHRlc3RfZW1wdHkucHJvdG8aJGdvb2ds" + 
+          "ZS9wcm90b2J1Zi9jc2hhcnBfb3B0aW9ucy5wcm90b0I+wj47CiFHb29nbGUu" + 
+          "UHJvdG9jb2xCdWZmZXJzLlRlc3RQcm90b3MSFlVuaXRUZXN0RW1wdHlQcm90" + 
+          "b0ZpbGU=");
+      pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {
+        descriptor = root;
+        pb::ExtensionRegistry registry = pb::ExtensionRegistry.CreateInstance();
+        RegisterAllExtensions(registry);
+        global::Google.ProtocolBuffers.DescriptorProtos.CSharpOptions.RegisterAllExtensions(registry);
+        return registry;
+      };
+      pbd::FileDescriptor.InternalBuildGeneratedFileFrom(descriptorData,
+          new pbd::FileDescriptor[] {
+          global::Google.ProtocolBuffers.DescriptorProtos.CSharpOptions.Descriptor, 
+          }, assigner);
+    }
+    #endregion
+    
+  }
+}

src/ProtocolBuffers.Test/TestProtos/UnitTestImportLiteProtoFile.cs

+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+
+using pb = global::Google.ProtocolBuffers;
+using pbc = global::Google.ProtocolBuffers.Collections;
+using pbd = global::Google.ProtocolBuffers.Descriptors;
+using scg = global::System.Collections.Generic;
+namespace Google.ProtocolBuffers.TestProtos {
+  
+  public static partial class UnitTestImportLiteProtoFile {
+  
+    #region Extension registration
+    public static void RegisterAllExtensions(pb::ExtensionRegistry registry) {
+    }
+    #endregion
+    #region Static variables
+    internal static pbd::MessageDescriptor internal__static_protobuf_unittest_import_ImportMessageLite__Descriptor;
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ImportMessageLite, global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.Builder> internal__static_protobuf_unittest_import_ImportMessageLite__FieldAccessorTable;
+    #endregion
+    #region Descriptor
+    public static pbd::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbd::FileDescriptor descriptor;
+    
+    static UnitTestImportLiteProtoFile() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          "Cipnb29nbGUvcHJvdG9idWYvdW5pdHRlc3RfaW1wb3J0X2xpdGUucHJvdG8S" + 
+          "GHByb3RvYnVmX3VuaXR0ZXN0X2ltcG9ydBokZ29vZ2xlL3Byb3RvYnVmL2Nz" + 
+          "aGFycF9vcHRpb25zLnByb3RvIh4KEUltcG9ydE1lc3NhZ2VMaXRlEgkKAWQY" + 
+          "ASABKAUqTwoOSW1wb3J0RW51bUxpdGUSEwoPSU1QT1JUX0xJVEVfRk9PEAcS" + 
+          "EwoPSU1QT1JUX0xJVEVfQkFSEAgSEwoPSU1QT1JUX0xJVEVfQkFaEAlCWgoT" + 
+          "Y29tLmdvb2dsZS5wcm90b2J1ZkgDwj5ACiFHb29nbGUuUHJvdG9jb2xCdWZm" + 
+          "ZXJzLlRlc3RQcm90b3MSG1VuaXRUZXN0SW1wb3J0TGl0ZVByb3RvRmlsZQ==");
+      pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {
+        descriptor = root;
+        internal__static_protobuf_unittest_import_ImportMessageLite__Descriptor = Descriptor.MessageTypes[0];
+        internal__static_protobuf_unittest_import_ImportMessageLite__FieldAccessorTable = 
+            new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ImportMessageLite, global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.Builder>(internal__static_protobuf_unittest_import_ImportMessageLite__Descriptor,
+                new string[] { "D", });
+        pb::ExtensionRegistry registry = pb::ExtensionRegistry.CreateInstance();
+        RegisterAllExtensions(registry);
+        global::Google.ProtocolBuffers.DescriptorProtos.CSharpOptions.RegisterAllExtensions(registry);
+        return registry;
+      };
+      pbd::FileDescriptor.InternalBuildGeneratedFileFrom(descriptorData,
+          new pbd::FileDescriptor[] {
+          global::Google.ProtocolBuffers.DescriptorProtos.CSharpOptions.Descriptor, 
+          }, assigner);
+    }
+    #endregion
+    
+  }
+  #region Enums
+  public enum ImportEnumLite {
+    IMPORT_LITE_FOO = 7,
+    IMPORT_LITE_BAR = 8,
+    IMPORT_LITE_BAZ = 9,
+  }
+  
+  #endregion
+  
+  #region Messages
+  public sealed partial class ImportMessageLite : pb::GeneratedMessage<ImportMessageLite, ImportMessageLite.Builder> {
+    private static readonly ImportMessageLite defaultInstance = new Builder().BuildPartial();
+    public static ImportMessageLite DefaultInstance {
+      get { return defaultInstance; }
+    }
+    
+    public override ImportMessageLite DefaultInstanceForType {
+      get { return defaultInstance; }
+    }
+    
+    protected override ImportMessageLite ThisMessage {
+      get { return this; }
+    }
+    
+    public static pbd::MessageDescriptor Descriptor {
+      get { return global::Google.ProtocolBuffers.TestProtos.UnitTestImportLiteProtoFile.internal__static_protobuf_unittest_import_ImportMessageLite__Descriptor; }
+    }
+    
+    protected override pb::FieldAccess.FieldAccessorTable<ImportMessageLite, ImportMessageLite.Builder> InternalFieldAccessors {
+      get { return global::Google.ProtocolBuffers.TestProtos.UnitTestImportLiteProtoFile.internal__static_protobuf_unittest_import_ImportMessageLite__FieldAccessorTable; }
+    }
+    
+    public const int DFieldNumber = 1;
+    private bool hasD;
+    private int d_ = 0;
+    public bool HasD {
+      get { return hasD; }
+    }
+    public int D {
+      get { return d_; }
+    }
+    
+    public static ImportMessageLite ParseFrom(pb::ByteString data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(pb::ByteString data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(byte[] data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(byte[] data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(global::System.IO.Stream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessageLite ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ImportMessageLite ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(pb::CodedInputStream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
+    }
+    public static Builder CreateBuilder() { return new Builder(); }
+    public override Builder ToBuilder() { return CreateBuilder(this); }
+    public override Builder CreateBuilderForType() { return new Builder(); }
+    public static Builder CreateBuilder(ImportMessageLite prototype) {
+      return (Builder) new Builder().MergeFrom(prototype);
+    }
+    
+    public sealed partial class Builder : pb::GeneratedBuilder<ImportMessageLite, Builder> {
+      protected override Builder ThisBuilder {
+        get { return this; }
+      }
+      public Builder() {}
+      
+      ImportMessageLite result = new ImportMessageLite();
+      
+      protected override ImportMessageLite MessageBeingBuilt {
+        get { return result; }
+      }
+      
+      public override Builder Clear() {
+        result = new ImportMessageLite();
+        return this;
+      }
+      
+      public override Builder Clone() {
+        return new Builder().MergeFrom(result);
+      }
+      
+      public override pbd::MessageDescriptor DescriptorForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.Descriptor; }
+      }
+      
+      public override ImportMessageLite DefaultInstanceForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.DefaultInstance; }
+      }
+      
+      public override ImportMessageLite BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
+        ImportMessageLite returnMe = result;
+        result = null;
+        return returnMe;
+      }
+      
+      
+      public bool HasD {
+        get { return result.HasD; }
+      }
+      public int D {
+        get { return result.D; }
+        set { SetD(value); }
+      }
+      public Builder SetD(int value) {
+        result.hasD = true;
+        result.d_ = value;
+        return this;
+      }
+      public Builder ClearD() {
+        result.hasD = false;
+        result.d_ = 0;
+        return this;
+      }
+    }
+    static ImportMessageLite() {
+      object.ReferenceEquals(global::Google.ProtocolBuffers.TestProtos.UnitTestImportLiteProtoFile.Descriptor, null);
+    }
+  }
+  
+  #endregion
+  
+}

src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtocolBuffers.sln

 
 Microsoft Visual Studio Solution File, Format Version 11.00
 # Visual Studio 2010
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "proto", "proto", "{1F896D5C-5FC2-4671-9216-781CB8187EC7}"
+	ProjectSection(SolutionItems) = preProject
+		..\protos\tutorial\addressbook.proto = ..\protos\tutorial\addressbook.proto
+		..\protos\google\protobuf\csharp_options.proto = ..\protos\google\protobuf\csharp_options.proto
+		..\protos\google\protobuf\descriptor.proto = ..\protos\google\protobuf\descriptor.proto
+		..\ProtocolBuffers.build = ..\ProtocolBuffers.build
+		..\todo.txt = ..\todo.txt
+	EndProjectSection
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "unittest", "unittest", "{C8D3015A-EA39-4F03-AEEC-3FF1F2087A12}"
+	ProjectSection(SolutionItems) = preProject
+		..\..\..\DotNet\ProtoFiles\Test\Protos\SampleComplex.proto = ..\..\..\DotNet\ProtoFiles\Test\Protos\SampleComplex.proto
+		..\protos\google\protobuf\unittest.proto = ..\protos\google\protobuf\unittest.proto
+		..\protos\google\protobuf\unittest_csharp_options.proto = ..\protos\google\protobuf\unittest_csharp_options.proto
+		..\protos\google\protobuf\unittest_custom_options.proto = ..\protos\google\protobuf\unittest_custom_options.proto
+		..\protos\google\protobuf\unittest_embed_optimize_for.proto = ..\protos\google\protobuf\unittest_embed_optimize_for.proto
+		..\protos\google\protobuf\unittest_empty.proto = ..\protos\google\protobuf\unittest_empty.proto
+		..\protos\google\protobuf\unittest_enormous_descriptor.proto = ..\protos\google\protobuf\unittest_enormous_descriptor.proto
+		..\protos\extest\unittest_extras_lite.proto = ..\protos\extest\unittest_extras_lite.proto
+		..\protos\google\protobuf\unittest_import.proto = ..\protos\google\protobuf\unittest_import.proto
+		..\protos\google\protobuf\unittest_import_lite.proto = ..\protos\google\protobuf\unittest_import_lite.proto
+		..\protos\google\protobuf\unittest_lite.proto = ..\protos\google\protobuf\unittest_lite.proto
+		..\protos\google\protobuf\unittest_lite_imports_nonlite.proto = ..\protos\google\protobuf\unittest_lite_imports_nonlite.proto
+		..\protos\google\protobuf\unittest_mset.proto = ..\protos\google\protobuf\unittest_mset.proto
+		..\protos\google\protobuf\unittest_no_generic_services.proto = ..\protos\google\protobuf\unittest_no_generic_services.proto
+		..\protos\google\protobuf\unittest_optimize_for.proto = ..\protos\google\protobuf\unittest_optimize_for.proto
+	EndProjectSection
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtocolBuffers", "ProtocolBuffers\ProtocolBuffers.csproj", "{6908BDCE-D925-43F3-94AC-A531E6DF2591}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtocolBuffers.Test", "ProtocolBuffers.Test\ProtocolBuffers.Test.csproj", "{DD01ED24-3750-4567-9A23-1DB676A15610}"
@@ -17,13 +45,11 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtoBench", "ProtoBench\Pr
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtoDump", "ProtoDump\ProtoDump.csproj", "{D7282E99-2DC3-405B-946F-177DB2FD2AE2}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "proto", "proto", "{1F896D5C-5FC2-4671-9216-781CB8187EC7}"
-	ProjectSection(SolutionItems) = preProject
-		..\protos\tutorial\addressbook.proto = ..\protos\tutorial\addressbook.proto
-		..\protos\google\protobuf\csharp_options.proto = ..\protos\google\protobuf\csharp_options.proto
-		..\protos\google\protobuf\descriptor.proto = ..\protos\google\protobuf\descriptor.proto
-		..\todo.txt = ..\todo.txt
-	EndProjectSection
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtocolBuffersLite", "ProtocolBuffers\ProtocolBuffersLite.csproj", "{6969BDCE-D925-43F3-94AC-A531E6DF2591}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtocolBuffersLite.Test", "ProtocolBuffersLite.Test\ProtocolBuffersLite.Test.csproj", "{EE01ED24-3750-4567-9A23-1DB676A15610}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtocolBuffersLiteMixed.Test", "ProtocolBuffersLite.Test\ProtocolBuffersLiteMixed.Test.csproj", "{EEFFED24-3750-4567-9A23-1DB676A15610}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -97,8 +123,35 @@ Global
 		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Release_Silverlight2|Any CPU.Build.0 = Release_Silverlight2|Any CPU
 		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Debug_Silverlight2|Any CPU.ActiveCfg = Debug_Silverlight2|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Debug_Silverlight2|Any CPU.Build.0 = Debug_Silverlight2|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Release_Silverlight2|Any CPU.ActiveCfg = Release_Silverlight2|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Release_Silverlight2|Any CPU.Build.0 = Release_Silverlight2|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6969BDCE-D925-43F3-94AC-A531E6DF2591}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Debug_Silverlight2|Any CPU.ActiveCfg = Debug_Silverlight2|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Debug_Silverlight2|Any CPU.Build.0 = Debug_Silverlight2|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Release_Silverlight2|Any CPU.ActiveCfg = Release_Silverlight2|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Release_Silverlight2|Any CPU.Build.0 = Release_Silverlight2|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EE01ED24-3750-4567-9A23-1DB676A15610}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Debug_Silverlight2|Any CPU.ActiveCfg = Debug_Silverlight2|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Debug_Silverlight2|Any CPU.Build.0 = Debug_Silverlight2|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Release_Silverlight2|Any CPU.ActiveCfg = Release_Silverlight2|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Release_Silverlight2|Any CPU.Build.0 = Release_Silverlight2|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EEFFED24-3750-4567-9A23-1DB676A15610}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{C8D3015A-EA39-4F03-AEEC-3FF1F2087A12} = {1F896D5C-5FC2-4671-9216-781CB8187EC7}
+	EndGlobalSection
 EndGlobal

src/ProtocolBuffers/AbstractBuilderLite.cs

+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// 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.
+#endregion
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Implementation of the non-generic IMessage interface as far as possible.
+  /// </summary>
+  public abstract class AbstractBuilderLite<TMessage, TBuilder> : IBuilderLite<TMessage, TBuilder>
+    where TMessage : AbstractMessageLite<TMessage, TBuilder>
+    where TBuilder : AbstractBuilderLite<TMessage, TBuilder> {
+
+    protected abstract TBuilder ThisBuilder { get; }
+
+    public abstract bool IsInitialized { get; }
+
+    public abstract TBuilder Clear();
+
+    public abstract TBuilder Clone();
+
+    public abstract TMessage Build();
+
+    public abstract TMessage BuildPartial();
+
+    public abstract TBuilder MergeFrom(IMessageLite other);
+
+    public abstract TBuilder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry);
+
+    public abstract TMessage DefaultInstanceForType { get; }
+
+    #region IBuilderLite<TMessage,TBuilder> Members
+
+    public virtual TBuilder MergeFrom(CodedInputStream input) {
+      return MergeFrom(input, ExtensionRegistry.CreateInstance());
+    }
+
+    public TBuilder MergeDelimitedFrom(Stream input) {
+      return MergeDelimitedFrom(input, ExtensionRegistry.CreateInstance());
+    }
+
+    public TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry) {
+      int size = (int)CodedInputStream.ReadRawVarint32(input);
+      Stream limitedStream = new LimitedInputStream(input, size);
+      return MergeFrom(limitedStream, extensionRegistry);
+    }
+
+    public TBuilder MergeFrom(ByteString data) {
+      return MergeFrom(data, ExtensionRegistry.CreateInstance());
+    }
+
+    public TBuilder MergeFrom(ByteString data, ExtensionRegistry extensionRegistry) {
+      CodedInputStream input = data.CreateCodedInput();
+      MergeFrom(input, extensionRegistry);
+      input.CheckLastTagWas(0);
+      return ThisBuilder;
+    }
+
+    public TBuilder MergeFrom(byte[] data) {
+      CodedInputStream input = CodedInputStream.CreateInstance(data);
+      MergeFrom(input);
+      input.CheckLastTagWas(0);
+      return ThisBuilder;
+    }
+
+    public TBuilder MergeFrom(byte[] data, ExtensionRegistry extensionRegistry) {
+      CodedInputStream input = CodedInputStream.CreateInstance(data);
+      MergeFrom(input, extensionRegistry);
+      input.CheckLastTagWas(0);
+      return ThisBuilder;
+    }
+
+    public TBuilder MergeFrom(Stream input) {
+      CodedInputStream codedInput = CodedInputStream.CreateInstance(input);
+      MergeFrom(codedInput);
+      codedInput.CheckLastTagWas(0);
+      return ThisBuilder;
+    }
+
+    public TBuilder MergeFrom(Stream input, ExtensionRegistry extensionRegistry) {
+      CodedInputStream codedInput = CodedInputStream.CreateInstance(input);
+      MergeFrom(codedInput, extensionRegistry);
+      codedInput.CheckLastTagWas(0);
+      return ThisBuilder;
+    }
+
+    #endregion
+    #region Explicit definitions
+
+    IBuilderLite IBuilderLite.WeakClear() {
+      return Clear();
+    }
+
+    IBuilderLite IBuilderLite.WeakMergeFrom(IMessageLite message) {
+      return MergeFrom(message);
+    }
+
+    IBuilderLite IBuilderLite.WeakMergeFrom(ByteString data) {
+      return MergeFrom(data);
+    }
+
+    IBuilderLite IBuilderLite.WeakMergeFrom(ByteString data, ExtensionRegistry registry) {
+      return MergeFrom(data, registry);
+    }
+
+    IBuilderLite IBuilderLite.WeakMergeFrom(CodedInputStream input) {
+      return MergeFrom(input);
+    }
+
+    IBuilderLite IBuilderLite.WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry) {
+      return MergeFrom(input, registry);
+    }
+
+    IMessageLite IBuilderLite.WeakBuild() {
+      return Build();
+    }
+
+    IMessageLite IBuilderLite.WeakBuildPartial() {
+      return BuildPartial();
+    }
+
+    IBuilderLite IBuilderLite.WeakClone() {
+      return Clone();
+    }
+
+    IMessageLite IBuilderLite.WeakDefaultInstanceForType {
+      get { return DefaultInstanceForType; }
+    }
+
+    #endregion
+    #region LimitedInputStream
+    /// <summary>
+    /// Stream implementation which proxies another stream, only allowing a certain amount
+    /// of data to be read. Note that this is only used to read delimited streams, so it
+    /// doesn't attempt to implement everything.
+    /// </summary>
+    private class LimitedInputStream : Stream {
+
+      private readonly Stream proxied;
+      private int bytesLeft;
+
+      internal LimitedInputStream(Stream proxied, int size) {
+        this.proxied = proxied;
+        bytesLeft = size;
+      }
+
+      public override bool CanRead {
+        get { return true; }
+      }
+
+      public override bool CanSeek {
+        get { return false; }
+      }
+
+      public override bool CanWrite {
+        get { return false; }
+      }
+
+      public override void Flush() {
+      }
+
+      public override long Length {
+        get { throw new NotSupportedException(); }
+      }
+
+      public override long Position {
+        get {
+          throw new NotSupportedException();
+        }
+        set {
+          throw new NotSupportedException();
+        }
+      }
+
+      public override int Read(byte[] buffer, int offset, int count) {
+        if (bytesLeft > 0) {
+          int bytesRead = proxied.Read(buffer, offset, Math.Min(bytesLeft, count));
+          bytesLeft -= bytesRead;
+          return bytesRead;
+        }
+        return 0;
+      }
+
+      public override long Seek(long offset, SeekOrigin origin) {
+        throw new NotSupportedException();
+      }
+
+      public override void SetLength(long value) {
+        throw new NotSupportedException();
+      }
+
+      public override void Write(byte[] buffer, int offset, int count) {
+        throw new NotSupportedException();
+      }
+    }
+    #endregion
+  }
+}

src/ProtocolBuffers/AbstractMessage.cs

@@ -42,7 +42,7 @@ namespace Google.ProtocolBuffers {
   /// <summary>
   /// Implementation of the non-generic IMessage interface as far as possible.
   /// </summary>
-  public abstract class AbstractMessage<TMessage, TBuilder> : IMessage<TMessage, TBuilder> 
+  public abstract class AbstractMessage<TMessage, TBuilder> : AbstractMessageLite<TMessage, TBuilder>, IMessage<TMessage, TBuilder> 
       where TMessage : AbstractMessage<TMessage, TBuilder> 
       where TBuilder : AbstractBuilder<TMessage, TBuilder> {
     /// <summary>
@@ -59,24 +59,13 @@ namespace Google.ProtocolBuffers {
     public abstract int GetRepeatedFieldCount(FieldDescriptor field);
     public abstract object this[FieldDescriptor field, int index] { get; }
     public abstract UnknownFieldSet UnknownFields { get; }
-    public abstract TMessage DefaultInstanceForType { get; }
-    public abstract TBuilder CreateBuilderForType();
-    public abstract TBuilder ToBuilder();
     #endregion
-    
-    public IBuilder WeakCreateBuilderForType() {
-      return CreateBuilderForType();
-    }
-
-    public IBuilder WeakToBuilder() {
-      return ToBuilder();
-    }
 
-    public IMessage WeakDefaultInstanceForType {
-      get { return DefaultInstanceForType; }
-    }
-
-    public virtual bool IsInitialized {
+    /// <summary>
+    /// Returns true iff all required fields in the message and all embedded
+    /// messages are set.
+    /// </summary>
+    public override bool IsInitialized {
       get {
         // Check that all required fields are present.
         foreach (FieldDescriptor field in DescriptorForType.Fields) {
@@ -92,13 +81,13 @@ namespace Google.ProtocolBuffers {
             if (field.IsRepeated) {
               // We know it's an IList<T>, but not the exact type - so
               // IEnumerable is the best we can do. (C# generics aren't covariant yet.)
-              foreach (IMessage element in (IEnumerable) entry.Value) {
+              foreach (IMessageLite element in (IEnumerable)entry.Value) {
                 if (!element.IsInitialized) {
                   return false;
                 }
               }
             } else {
-              if (!((IMessage)entry.Value).IsInitialized) {
+              if (!((IMessageLite)entry.Value).IsInitialized) {
                 return false;
               }
             }
@@ -112,7 +101,23 @@ namespace Google.ProtocolBuffers {
       return TextFormat.PrintToString(this);
     }
 
-    public virtual void WriteTo(CodedOutputStream output) {
+    public sealed override void PrintTo(TextWriter writer) {
+      TextFormat.Print(this, writer);
+    }
+
+    /// <summary>
+    /// Serializes the message and writes it to the given output stream.
+    /// This does not flush or close the stream.
+    /// </summary>
+    /// <remarks>
+    /// Protocol Buffers are not self-delimiting. Therefore, if you write
+    /// any more data to the stream after the message, you must somehow ensure
+    /// that the parser on the receiving end does not interpret this as being
+    /// part of the protocol message. One way of doing this is by writing the size
+    /// of the message before the data, then making sure you limit the input to
+    /// that size when receiving the data. Alternatively, use WriteDelimitedTo(Stream).
+    /// </remarks>
+    public override void WriteTo(CodedOutputStream output) {
       foreach (KeyValuePair<FieldDescriptor, object> entry in AllFields) {
         FieldDescriptor field = entry.Key;
         if (field.IsRepeated) {
@@ -147,7 +152,11 @@ namespace Google.ProtocolBuffers {
       }
     }
 
-    public virtual int SerializedSize {
+    /// <summary>
+    /// Returns the number of bytes required to encode this message.
+    /// The result is only computed on the first call and memoized after that.
+    /// </summary>
+    public override int SerializedSize {
       get {
         if (memoizedSize != null) {
           return memoizedSize.Value;
@@ -188,33 +197,12 @@ namespace Google.ProtocolBuffers {
       }
     }
 
-    public ByteString ToByteString() {
-      ByteString.CodedBuilder output = new ByteString.CodedBuilder(SerializedSize);
-      WriteTo(output.CodedOutput);
-      return output.Build();
-    }
-
-    public byte[] ToByteArray() {
-      byte[] result = new byte[SerializedSize];
-      CodedOutputStream output = CodedOutputStream.CreateInstance(result);
-      WriteTo(output);
-      output.CheckNoSpaceLeft();
-      return result;
-    }
-
-    public void WriteTo(Stream output) {
-      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
-      WriteTo(codedOutput);
-      codedOutput.Flush();
-    }
-
-    public void WriteDelimitedTo(Stream output) {
-      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
-      codedOutput.WriteRawVarint32((uint) SerializedSize);
-      WriteTo(codedOutput);
-      codedOutput.Flush();
-    }
-
+    /// <summary>
+    /// Compares the specified object with this message for equality.
+    /// Returns true iff the given object is a message of the same type
+    /// (as defined by DescriptorForType) and has identical values
+    /// for all its fields.
+    /// </summary>
     public override bool Equals(object other) {
       if (other == this) {
         return true;
@@ -226,6 +214,10 @@ namespace Google.ProtocolBuffers {
       return Dictionaries.Equals(AllFields, otherMessage.AllFields) && UnknownFields.Equals(otherMessage.UnknownFields);
     }
 
+    /// <summary>
+    /// Returns the hash code value for this message.
+    /// TODO(jonskeet): Specify the hash algorithm, but better than the Java one!
+    /// </summary>
     public override int GetHashCode() {
       int hash = 41;
       hash = (19 * hash) + DescriptorForType.GetHashCode();
@@ -233,5 +225,21 @@ namespace Google.ProtocolBuffers {
       hash = (29 * hash) + UnknownFields.GetHashCode();
       return hash;
     }
+
+    #region Explicit Members
+    
+    IBuilder IMessage.WeakCreateBuilderForType() {
+      return CreateBuilderForType();
+    }
+
+    IBuilder IMessage.WeakToBuilder() {
+      return ToBuilder();
+    }
+
+    IMessage IMessage.WeakDefaultInstanceForType {
+      get { return DefaultInstanceForType; }
+    }
+
+    #endregion
   }
 }

src/ProtocolBuffers/AbstractMessageLite.cs

+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// 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.
+#endregion
+
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Implementation of the non-generic IMessage interface as far as possible.
+  /// </summary>
+  public abstract class AbstractMessageLite<TMessage, TBuilder> : IMessageLite<TMessage, TBuilder>
+    where TMessage : AbstractMessageLite<TMessage, TBuilder>
+    where TBuilder : AbstractBuilderLite<TMessage, TBuilder> {
+ 
+    
+    public abstract TBuilder CreateBuilderForType();
+
+    public abstract TBuilder ToBuilder();
+
+    public abstract TMessage DefaultInstanceForType { get; }
+
+    public abstract bool IsInitialized { get; }
+
+    public abstract void WriteTo(CodedOutputStream output);
+
+    public abstract int SerializedSize { get; }
+
+    //public override bool Equals(object other) {
+    //}
+
+    //public override int GetHashCode() {
+    //}
+
+    public abstract void PrintTo(TextWriter writer);
+
+    #region IMessageLite<TMessage,TBuilder> Members
+
+    /// <summary>
+    /// Serializes the message to a ByteString. This is a trivial wrapper
+    /// around WriteTo(CodedOutputStream).
+    /// </summary>
+    public ByteString ToByteString() {
+      ByteString.CodedBuilder output = new ByteString.CodedBuilder(SerializedSize);
+      WriteTo(output.CodedOutput);
+      return output.Build();
+    }
+
+    /// <summary>
+    /// Serializes the message to a byte array. This is a trivial wrapper
+    /// around WriteTo(CodedOutputStream).
+    /// </summary>
+    public byte[] ToByteArray() {
+      byte[] result = new byte[SerializedSize];
+      CodedOutputStream output = CodedOutputStream.CreateInstance(result);
+      WriteTo(output);
+      output.CheckNoSpaceLeft();
+      return result;
+    }
+
+    /// <summary>
+    /// Serializes the message and writes it to the given stream.
+    /// This is just a wrapper around WriteTo(CodedOutputStream). This
+    /// does not flush or close the stream.
+    /// </summary>
+    /// <param name="output"></param>
+    public void WriteTo(Stream output) {
+      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
+      WriteTo(codedOutput);
+      codedOutput.Flush();
+    }
+
+    /// <summary>
+    /// Like WriteTo(Stream) but writes the size of the message as a varint before
+    /// writing the data. This allows more data to be written to the stream after the
+    /// message without the need to delimit the message data yourself. Use 
+    /// IBuilder.MergeDelimitedFrom(Stream) or the static method
+    /// YourMessageType.ParseDelimitedFrom(Stream) to parse messages written by this method.
+    /// </summary>
+    /// <param name="output"></param>
+    public void WriteDelimitedTo(Stream output) {
+      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
+      codedOutput.WriteRawVarint32((uint)SerializedSize);
+      WriteTo(codedOutput);
+      codedOutput.Flush();
+    }
+
+    IBuilderLite IMessageLite.WeakCreateBuilderForType() {
+      return CreateBuilderForType();
+    }
+
+    IBuilderLite IMessageLite.WeakToBuilder() {
+      return ToBuilder();
+    }
+
+    IMessageLite IMessageLite.WeakDefaultInstanceForType {
+      get { return DefaultInstanceForType; }
+    }
+
+    #endregion
+  }
+}

src/ProtocolBuffers/ByteString.cs

@@ -78,6 +78,13 @@ namespace Google.ProtocolBuffers {
       return (byte[])bytes.Clone();
     }
 
+    /// <summary>
+    /// Constructs a ByteString from the Base64 Encoded String.
+    /// </summary>
+    public static ByteString FromBase64(string bytes) {
+      return new ByteString(System.Convert.FromBase64String(bytes));
+    }
+
     /// <summary>
     /// Constructs a ByteString from the given array. The contents
     /// are copied, so further modifications to the array will not

src/ProtocolBuffers/CodedInputStream.cs

@@ -258,7 +258,7 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Reads a group field value from the stream.
     /// </summary>    
-    public void ReadGroup(int fieldNumber, IBuilder builder,
+    public void ReadGroup(int fieldNumber, IBuilderLite builder,
                           ExtensionRegistry extensionRegistry) {
       if (recursionDepth >= recursionLimit) {
         throw InvalidProtocolBufferException.RecursionLimitExceeded();
@@ -273,12 +273,14 @@ namespace Google.ProtocolBuffers {
     /// Reads a group field value from the stream and merges it into the given
     /// UnknownFieldSet.
     /// </summary>   
-    public void ReadUnknownGroup(int fieldNumber, UnknownFieldSet.Builder builder) {
+    [Obsolete]
+    public void ReadUnknownGroup(int fieldNumber, IBuilderLite builder)
+    {
       if (recursionDepth >= recursionLimit) {
         throw InvalidProtocolBufferException.RecursionLimitExceeded();
       }
       ++recursionDepth;
-      builder.MergeFrom(this);
+      builder.WeakMergeFrom(this);
       CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup));
       --recursionDepth;
     }
@@ -286,7 +288,7 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Reads an embedded message field value from the stream.
     /// </summary>   
-    public void ReadMessage(IBuilder builder, ExtensionRegistry extensionRegistry) {
+    public void ReadMessage(IBuilderLite builder, ExtensionRegistry extensionRegistry) {
       int length = (int) ReadRawVarint32();
       if (recursionDepth >= recursionLimit) {
         throw InvalidProtocolBufferException.RecursionLimitExceeded();
@@ -393,7 +395,6 @@ namespace Google.ProtocolBuffers {
           throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);
       }
     }
-
     #endregion
 
     #region Underlying reading primitives

src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs

-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
 
 using pb = global::Google.ProtocolBuffers;
 using pbc = global::Google.ProtocolBuffers.Collections;

src/ProtocolBuffers/Descriptors/EnumDescriptor.cs

@@ -37,7 +37,7 @@ namespace Google.ProtocolBuffers.Descriptors {
   /// <summary>
   /// Descriptor for an enum type in a .proto file.
   /// </summary>
-  public sealed class EnumDescriptor : IndexedDescriptorBase<EnumDescriptorProto, EnumOptions> {
+  public sealed class EnumDescriptor : IndexedDescriptorBase<EnumDescriptorProto, EnumOptions>, IEnumLiteMap<EnumValueDescriptor> {
 
     private readonly MessageDescriptor containingType;
     private readonly IList<EnumValueDescriptor> values;
@@ -72,14 +72,24 @@ namespace Google.ProtocolBuffers.Descriptors {
       get { return values; }
     }
 
+    /// <summary>
+    /// Logic moved from FieldSet to continue current behavior
+    /// </summary>
+    public bool IsValidValue(IEnumLite value) {
+      return value is EnumValueDescriptor && ((EnumValueDescriptor)value).EnumDescriptor == this;
+    }
+
     /// <summary>
     /// Finds an enum value by number. If multiple enum values have the
     /// same number, this returns the first defined value with that number.
     /// </summary>
-    internal EnumValueDescriptor FindValueByNumber(int number) {
+    public EnumValueDescriptor FindValueByNumber(int number) {
       return File.DescriptorPool.FindEnumValueByNumber(this, number);
     }
 
+    IEnumLite IEnumLiteMap.FindValueByNumber(int number) {
+      return FindValueByNumber(number);
+    }
     /// <summary>
     /// Finds an enum value by name.
     /// </summary>

src/ProtocolBuffers/Descriptors/EnumValueDescriptor.cs

@@ -36,7 +36,7 @@ namespace Google.ProtocolBuffers.Descriptors {
   /// <summary>
   /// Descriptor for a single enum value within an enum in a .proto file.
   /// </summary>
-  public sealed class EnumValueDescriptor : IndexedDescriptorBase<EnumValueDescriptorProto, EnumValueOptions> {
+  public sealed class EnumValueDescriptor : IndexedDescriptorBase<EnumValueDescriptorProto, EnumValueOptions>, IEnumLite {
 
     private readonly EnumDescriptor enumDescriptor;
 

src/ProtocolBuffers/Descriptors/FieldDescriptor.cs

@@ -40,7 +40,7 @@ namespace Google.ProtocolBuffers.Descriptors {
   /// <summary>
   /// Descriptor for a field or extension within a message in a .proto file.
   /// </summary>
-  public sealed class FieldDescriptor : IndexedDescriptorBase<FieldDescriptorProto, FieldOptions>, IComparable<FieldDescriptor> {
+  public sealed class FieldDescriptor : IndexedDescriptorBase<FieldDescriptorProto, FieldOptions>, IComparable<FieldDescriptor>, IFieldDescriptorLite {
 
     private readonly MessageDescriptor extensionScope;
     private EnumDescriptor enumType;
@@ -299,9 +299,26 @@ namespace Google.ProtocolBuffers.Descriptors {
       }
       return FieldNumber - other.FieldNumber;
     }
-    
 
     /// <summary>
+    /// Compares this descriptor with another one, ordering in "canonical" order
+    /// which simply means ascending order by field number. <paramref name="other"/>
+    /// must be a field of the same type, i.e. the <see cref="ContainingType"/> of
+    /// both fields must be the same.
+    /// </summary>
+    public int CompareTo(IFieldDescriptorLite other) {
+      return FieldNumber - other.FieldNumber;
+    }
+
+    IEnumLiteMap IFieldDescriptorLite.EnumType {
+      get { return EnumType; }
+    }
+
+    bool IFieldDescriptorLite.MessageSetWireFormat {
+      get { return ContainingType.Options.MessageSetWireFormat; }
+    }
+
+      /// <summary>
     /// For enum fields, returns the field's type.
     /// </summary>
     public EnumDescriptor EnumType {

src/ProtocolBuffers/Descriptors/FieldMappingAttribute.cs

@@ -30,6 +30,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 using System;
+using System.Collections.Generic;
+using Google.ProtocolBuffers.Collections;
 
 namespace Google.ProtocolBuffers.Descriptors {
 
@@ -46,5 +48,29 @@ namespace Google.ProtocolBuffers.Descriptors {
 
     internal MappedType MappedType { get; private set; }
     internal WireFormat.WireType WireType { get; private set; }
+
+
+    /// <summary>
+    /// Immutable mapping from field type to mapped type. Built using the attributes on
+    /// FieldType values.
+    /// </summary>
+    static readonly IDictionary<FieldType, FieldMappingAttribute> FieldTypeToMappedTypeMap = MapFieldTypes();
+
+    private static IDictionary<FieldType, FieldMappingAttribute> MapFieldTypes() {
+      var map = new Dictionary<FieldType, FieldMappingAttribute>();
+      foreach (System.Reflection.FieldInfo field in typeof(FieldType).GetFields(System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.Public)) {
+        FieldType fieldType = (FieldType)field.GetValue(null);
+        FieldMappingAttribute mapping = (FieldMappingAttribute)field.GetCustomAttributes(typeof(FieldMappingAttribute), false)[0];
+        map[fieldType] = mapping;
+      }
+      return Dictionaries.AsReadOnly(map);
+    }
+
+    internal static MappedType MappedTypeFromFieldType(FieldType type) {
+      return FieldTypeToMappedTypeMap[type].MappedType;
+    }
+    internal static WireFormat.WireType WireTypeFromFieldType(FieldType type, bool packed) {
+      return packed ? WireFormat.WireType.LengthDelimited : FieldTypeToMappedTypeMap[type].WireType;
+    }
   }
 }

src/ProtocolBuffers/DynamicMessage.cs

@@ -180,7 +180,7 @@ namespace Google.ProtocolBuffers {
     }
 
     public override IDictionary<FieldDescriptor, object> AllFields {
-      get { return fields.AllFields; }
+      get { return fields.AllFieldDescriptors; }
     }
 
     public override bool HasField(FieldDescriptor field) {
@@ -216,7 +216,7 @@ namespace Google.ProtocolBuffers {
     }
 
     public bool Initialized {
-      get { return fields.IsInitializedWithRespectTo(type); }
+      get { return fields.IsInitializedWithRespectTo(type.Fields); }
     }
 
     public override void WriteTo(CodedOutputStream output) {
@@ -295,7 +295,8 @@ namespace Google.ProtocolBuffers {
       }
 
       public override Builder MergeFrom(DynamicMessage other) {
-        return MergeFrom((IMessage)other);
+        IMessage downcast = other;
+        return MergeFrom(downcast);
       }
 
       public override DynamicMessage Build() {
@@ -335,7 +336,7 @@ namespace Google.ProtocolBuffers {
       }
 
       public override bool IsInitialized {
-          get { return fields.IsInitializedWithRespectTo(type); }
+          get { return fields.IsInitializedWithRespectTo(type.Fields); }
       }
 
       public override Builder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry) {
@@ -354,7 +355,7 @@ namespace Google.ProtocolBuffers {
       }
 
       public override IDictionary<FieldDescriptor, object> AllFields {
-        get { return fields.AllFields; }
+        get { return fields.AllFieldDescriptors; }
       }
 
       public override IBuilder CreateBuilderForField(FieldDescriptor field) {

src/ProtocolBuffers/EnumLite.cs

+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// 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.
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+
+namespace Google.ProtocolBuffers {
+
+  ///<summary>
+  ///Interface for an enum value or value descriptor, to be used in FieldSet.
+  ///The lite library stores enum values directly in FieldSets but the full
+  ///library stores EnumValueDescriptors in order to better support reflection.
+  ///</summary>
+  public interface IEnumLite {
+    int Number { get; }
+    string Name { get; }
+  }
+
+  ///<summary>
+  ///Interface for an object which maps integers to {@link EnumLite}s.
+  ///{@link Descriptors.EnumDescriptor} implements this interface by mapping
+  ///numbers to {@link Descriptors.EnumValueDescriptor}s.  Additionally,
+  ///every generated enum type has a static method internalGetValueMap() which
+  ///returns an implementation of this type that maps numbers to enum values.
+  ///</summary>
+  public interface IEnumLiteMap<T> : IEnumLiteMap
+    where T : IEnumLite {
+    new T FindValueByNumber(int number);
+  }
+
+  public interface IEnumLiteMap {
+    bool IsValidValue(IEnumLite value);
+    IEnumLite FindValueByNumber(int number);
+  }
+
+  public class EnumLiteMap<TEnum> : IEnumLiteMap<IEnumLite>
+    where TEnum : struct, IComparable, IFormattable {
+    
+    struct EnumValue : IEnumLite {
+      readonly TEnum value;
+      public EnumValue(TEnum value) {
+        this.value = value;
+      }
+      int IEnumLite.Number {
+        get { return Convert.ToInt32(value); }
+      }
+      string IEnumLite.Name {
+        get { return value.ToString(); }
+      }
+    }
+
+    private readonly SortedList<int, IEnumLite> items;
+
+    public EnumLiteMap() {
+      items = new SortedList<int, IEnumLite>();
+      foreach (TEnum evalue in Enum.GetValues(typeof(TEnum)))
+        items.Add(Convert.ToInt32(evalue), new EnumValue(evalue));
+    }
+
+    IEnumLite IEnumLiteMap.FindValueByNumber(int number) {
+      return FindValueByNumber(number);
+    }
+
+    public IEnumLite FindValueByNumber(int number) {
+      IEnumLite val;
+      return items.TryGetValue(number, out val) ? val : null;
+    }
+
+    public bool IsValidValue(IEnumLite value) {
+      return items.ContainsKey(value.Number);
+    }
+  }
+}

src/ProtocolBuffers/ExtendableBuilder.cs

@@ -94,21 +94,21 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Appends a value to a repeated extension.
     /// </summary>
-    public ExtendableBuilder<TMessage, TBuilder> AddExtension<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension, TExtension value) {
+    public TBuilder AddExtension<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension, TExtension value) {
       ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
       message.VerifyExtensionContainingType(extension);
       message.Extensions.AddRepeatedField(extension.Descriptor, extension.SingularToReflectionType(value));
-      return this;
+      return ThisBuilder;
     }
 
     /// <summary>
     /// Clears an extension.
     /// </summary>
-    public ExtendableBuilder<TMessage, TBuilder> ClearExtension<TExtension>(GeneratedExtensionBase<TExtension> extension) {
+    public TBuilder ClearExtension<TExtension>(GeneratedExtensionBase<TExtension> extension) {
       ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
       message.VerifyExtensionContainingType(extension);
       message.Extensions.ClearField(extension.Descriptor);
-      return this;
+      return ThisBuilder;
     }
 
     /// <summary>

src/ProtocolBuffers/ExtendableMessage.cs

@@ -102,8 +102,8 @@ namespace Google.ProtocolBuffers {
     public override IDictionary<FieldDescriptor, object> AllFields {
       get {
         IDictionary<FieldDescriptor, object> result = GetMutableFieldMap();
-        foreach(KeyValuePair<FieldDescriptor, object> entry in extensions.AllFields) {
-          result[entry.Key] = entry.Value;
+        foreach(KeyValuePair<IFieldDescriptorLite, object> entry in extensions.AllFields) {
+          result[(FieldDescriptor)entry.Key] = entry.Value;
         }
         return Dictionaries.AsReadOnly(result);
       }
@@ -173,9 +173,9 @@ namespace Google.ProtocolBuffers {
     /// TODO(jonskeet): See if we can improve this in terms of readability.
     /// </summary>
     protected class ExtensionWriter {
-      readonly IEnumerator<KeyValuePair<FieldDescriptor, object>> iterator;
+      readonly IEnumerator<KeyValuePair<IFieldDescriptorLite, object>> iterator;
       readonly FieldSet extensions;
-      KeyValuePair<FieldDescriptor, object>? next = null;
+      KeyValuePair<IFieldDescriptorLite, object>? next = null;
 
       internal ExtensionWriter(ExtendableMessage<TMessage, TBuilder> message) {
         extensions = message.extensions;

src/ProtocolBuffers/ExtensionInfo.cs

@@ -36,24 +36,42 @@ using Google.ProtocolBuffers.Descriptors;
 
 namespace Google.ProtocolBuffers
 {
-  public sealed class ExtensionInfo {
+  public sealed class ExtensionInfo : IGeneratedExtensionLite {
     /// <summary>
     /// The extension's descriptor
     /// </summary>
     public FieldDescriptor Descriptor { get; private set; }
 
-    /// <summary>
+    IFieldDescriptorLite IGeneratedExtensionLite.Descriptor { get { return Descriptor; } }
+
+      /// <summary>
     /// A default instance of the extensions's type, if it has a message type,
     /// or null otherwise.
     /// </summary>
-    public IMessage DefaultInstance { get; private set; }
+    public IMessageLite DefaultInstance { get; private set; }
 
     internal ExtensionInfo(FieldDescriptor descriptor) : this(descriptor, null) {
     }
 
-    internal ExtensionInfo(FieldDescriptor descriptor, IMessage defaultInstance) {
+    internal ExtensionInfo(FieldDescriptor descriptor, IMessageLite defaultInstance) {
       Descriptor = descriptor;
       DefaultInstance = defaultInstance;
     }
+
+    #region IGeneratedExtensionLite Members
+
+    int IGeneratedExtensionLite.Number {
+      get { return Descriptor.FieldNumber; }
+    }
+
+    object IGeneratedExtensionLite.ContainingType {
+      get { return Descriptor; }
+    }
+
+    IMessageLite IGeneratedExtensionLite.MessageDefaultInstance {
+      get { return DefaultInstance; }
+    }
+
+    #endregion
   }
 }
\ No newline at end of file

src/ProtocolBuffers/ExtensionRegistry.cs

@@ -88,23 +88,20 @@ namespace Google.ProtocolBuffers {
   /// could take advantage of this to inject a mutable object into a message
   /// belonging to privileged code and create mischief.</para>
   /// </remarks>
-  public sealed class ExtensionRegistry {
-
+  public sealed partial class ExtensionRegistry {
+#if !LITE
     private static readonly ExtensionRegistry empty = new ExtensionRegistry(
         new Dictionary<string, ExtensionInfo>(),
-        new Dictionary<DescriptorIntPair, ExtensionInfo>(),
+        new Dictionary<ExtensionIntPair, IGeneratedExtensionLite>(),
         true);
 
     private readonly IDictionary<string, ExtensionInfo> extensionsByName;
-    private readonly IDictionary<DescriptorIntPair, ExtensionInfo> extensionsByNumber;
-    private readonly bool readOnly;
 
     private ExtensionRegistry(IDictionary<String, ExtensionInfo> extensionsByName,
-        IDictionary<DescriptorIntPair, ExtensionInfo> extensionsByNumber,
-        bool readOnly) {
+        IDictionary<ExtensionIntPair, IGeneratedExtensionLite> extensionsByNumber,
+        bool readOnly)
+      : this(extensionsByNumber, readOnly) {
       this.extensionsByName = extensionsByName;
-      this.extensionsByNumber = extensionsByNumber;
-      this.readOnly = readOnly;
     }
 
     /// <summary>
@@ -112,19 +109,13 @@ namespace Google.ProtocolBuffers {
     /// </summary>
     public static ExtensionRegistry CreateInstance() {
       return new ExtensionRegistry(new Dictionary<string, ExtensionInfo>(),
-        new Dictionary<DescriptorIntPair, ExtensionInfo>(), false);
-    }
-
-    /// <summary>
-    /// Get the unmodifiable singleton empty instance.
-    /// </summary>
-    public static ExtensionRegistry Empty {
-      get { return empty; }
+        new Dictionary<ExtensionIntPair, IGeneratedExtensionLite>(), false);
     }
 
     public ExtensionRegistry AsReadOnly() {
       return new ExtensionRegistry(extensionsByName, extensionsByNumber, true);
     }
+#endif
 
     /// <summary>
     /// Finds an extension by fully-qualified field name, in the
@@ -146,9 +137,9 @@ namespace Google.ProtocolBuffers {
     /// </summary>
     public ExtensionInfo this[MessageDescriptor containingType, int fieldNumber] {
       get {
-        ExtensionInfo ret;
-        extensionsByNumber.TryGetValue(new DescriptorIntPair(containingType, fieldNumber), out ret);
-        return ret;
+        IGeneratedExtensionLite ret;
+        extensionsByNumber.TryGetValue(new ExtensionIntPair(containingType, fieldNumber), out ret);
+        return ret as ExtensionInfo;
       }
     }
 
@@ -198,7 +189,7 @@ namespace Google.ProtocolBuffers {
       }
 
       extensionsByName[extension.Descriptor.FullName] = extension;
-      extensionsByNumber[new DescriptorIntPair(extension.Descriptor.ContainingType,
+      extensionsByNumber[new ExtensionIntPair(extension.Descriptor.ContainingType,
           extension.Descriptor.FieldNumber)] = extension;
 
       FieldDescriptor field = extension.Descriptor;
@@ -212,34 +203,5 @@ namespace Google.ProtocolBuffers {
         extensionsByName[field.MessageType.FullName] = extension;
       }
     }
-
-    /// <summary>
-    /// Nested type just used to represent a pair of MessageDescriptor and int, as
-    /// the key into the "by number" map.
-    /// </summary>
-    private struct DescriptorIntPair : IEquatable<DescriptorIntPair> {
-      readonly MessageDescriptor descriptor;
-      readonly int number;
-
-      internal DescriptorIntPair(MessageDescriptor descriptor, int number) {
-        this.descriptor = descriptor;
-        this.number = number;
-      }
-
-      public override int GetHashCode() {
-        return descriptor.GetHashCode() * ((1 << 16) - 1) + number;
-      }
-
-      public override bool Equals(object obj) {
-        if (!(obj is DescriptorIntPair)) {
-          return false;
-        }
-        return Equals((DescriptorIntPair)obj);
-      }
-
-      public bool Equals(DescriptorIntPair other) {
-        return descriptor == other.descriptor && number == other.number;
-      }
-    }
   }
 }

src/ProtocolBuffers/FieldAccess/RepeatedMessageAccessor.cs

@@ -71,7 +71,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
       }
 
       // No... so let's create a builder of the right type, and merge the value in.
-      IMessage message = (IMessage) value;
+      IMessageLite message = (IMessageLite) value;
       return CreateBuilder().WeakMergeFrom(message).WeakBuild();
     }
 

src/ProtocolBuffers/FieldAccess/SingleMessageAccessor.cs

@@ -67,7 +67,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
       }
       
       // No... so let's create a builder of the right type, and merge the value in.
-      IMessage message = (IMessage) value;
+      IMessageLite message = (IMessageLite) value;
       return CreateBuilder().WeakMergeFrom(message).WeakBuild();
     }