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
+mono/*.dll

protos/extest/unittest_extras_full.proto

@@ -0,0 +1,72 @@
+// 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

@@ -0,0 +1,61 @@
+// 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

@@ -0,0 +1,43 @@
+// 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

@@ -0,0 +1,55 @@
+// 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.proto

@@ -0,0 +1,318 @@
+// 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 = "UnitTestLiteProtoFile";
+
+// 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.proto but with optimize_for = LITE_RUNTIME.
+
+package protobuf_unittest;
+
+import "google/protobuf/unittest_import_lite.proto";
+
+option optimize_for = LITE_RUNTIME;
+
+option java_package = "com.google.protobuf";
+
+// Same as TestAllTypes but with the lite runtime.
+message TestAllTypesLite {
+  message NestedMessage {
+    optional int32 bb = 1;
+  }
+
+  enum NestedEnum {
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+  }
+
+  // Singular
+  optional    int32 optional_int32    =  1;
+  optional    int64 optional_int64    =  2;
+  optional   uint32 optional_uint32   =  3;
+  optional   uint64 optional_uint64   =  4;
+  optional   sint32 optional_sint32   =  5;
+  optional   sint64 optional_sint64   =  6;
+  optional  fixed32 optional_fixed32  =  7;
+  optional  fixed64 optional_fixed64  =  8;
+  optional sfixed32 optional_sfixed32 =  9;
+  optional sfixed64 optional_sfixed64 = 10;
+  optional    float optional_float    = 11;
+  optional   double optional_double   = 12;
+  optional     bool optional_bool     = 13;
+  optional   string optional_string   = 14;
+  optional    bytes optional_bytes    = 15;
+
+  optional group OptionalGroup = 16 {
+    optional int32 a = 17;
+  }
+
+  optional NestedMessage      optional_nested_message  = 18;
+  optional ForeignMessageLite optional_foreign_message = 19;
+  optional protobuf_unittest_import.ImportMessageLite
+    optional_import_message = 20;
+
+  optional NestedEnum      optional_nested_enum     = 21;
+  optional ForeignEnumLite optional_foreign_enum    = 22;
+  optional protobuf_unittest_import.ImportEnumLite optional_import_enum = 23;
+
+  optional string optional_string_piece = 24 [ctype=STRING_PIECE];
+  optional string optional_cord = 25 [ctype=CORD];
+
+  // Repeated
+  repeated    int32 repeated_int32    = 31;
+  repeated    int64 repeated_int64    = 32;
+  repeated   uint32 repeated_uint32   = 33;
+  repeated   uint64 repeated_uint64   = 34;
+  repeated   sint32 repeated_sint32   = 35;
+  repeated   sint64 repeated_sint64   = 36;
+  repeated  fixed32 repeated_fixed32  = 37;
+  repeated  fixed64 repeated_fixed64  = 38;
+  repeated sfixed32 repeated_sfixed32 = 39;
+  repeated sfixed64 repeated_sfixed64 = 40;
+  repeated    float repeated_float    = 41;
+  repeated   double repeated_double   = 42;
+  repeated     bool repeated_bool     = 43;
+  repeated   string repeated_string   = 44;
+  repeated    bytes repeated_bytes    = 45;
+
+  repeated group RepeatedGroup = 46 {
+    optional int32 a = 47;
+  }
+
+  repeated NestedMessage      repeated_nested_message  = 48;
+  repeated ForeignMessageLite repeated_foreign_message = 49;
+  repeated protobuf_unittest_import.ImportMessageLite
+    repeated_import_message = 50;
+
+  repeated NestedEnum      repeated_nested_enum  = 51;
+  repeated ForeignEnumLite repeated_foreign_enum = 52;
+  repeated protobuf_unittest_import.ImportEnumLite repeated_import_enum = 53;
+
+  repeated string repeated_string_piece = 54 [ctype=STRING_PIECE];
+  repeated string repeated_cord = 55 [ctype=CORD];
+
+  // Singular with defaults
+  optional    int32 default_int32    = 61 [default =  41    ];
+  optional    int64 default_int64    = 62 [default =  42    ];
+  optional   uint32 default_uint32   = 63 [default =  43    ];
+  optional   uint64 default_uint64   = 64 [default =  44    ];
+  optional   sint32 default_sint32   = 65 [default = -45    ];
+  optional   sint64 default_sint64   = 66 [default =  46    ];
+  optional  fixed32 default_fixed32  = 67 [default =  47    ];
+  optional  fixed64 default_fixed64  = 68 [default =  48    ];
+  optional sfixed32 default_sfixed32 = 69 [default =  49    ];
+  optional sfixed64 default_sfixed64 = 70 [default = -50    ];
+  optional    float default_float    = 71 [default =  51.5  ];
+  optional   double default_double   = 72 [default =  52e3  ];
+  optional     bool default_bool     = 73 [default = true   ];
+  optional   string default_string   = 74 [default = "hello"];
+  optional    bytes default_bytes    = 75 [default = "world"];
+
+  optional NestedEnum default_nested_enum = 81 [default = BAR];
+  optional ForeignEnumLite default_foreign_enum = 82
+      [default = FOREIGN_LITE_BAR];
+  optional protobuf_unittest_import.ImportEnumLite
+      default_import_enum = 83 [default = IMPORT_LITE_BAR];
+
+  optional string default_string_piece = 84 [ctype=STRING_PIECE,default="abc"];
+  optional string default_cord = 85 [ctype=CORD,default="123"];
+}
+
+message ForeignMessageLite {
+  optional int32 c = 1;
+}
+
+enum ForeignEnumLite {
+  FOREIGN_LITE_FOO = 4;
+  FOREIGN_LITE_BAR = 5;
+  FOREIGN_LITE_BAZ = 6;
+}
+
+message TestPackedTypesLite {
+  repeated    int32 packed_int32    =  90 [packed = true];
+  repeated    int64 packed_int64    =  91 [packed = true];
+  repeated   uint32 packed_uint32   =  92 [packed = true];
+  repeated   uint64 packed_uint64   =  93 [packed = true];
+  repeated   sint32 packed_sint32   =  94 [packed = true];
+  repeated   sint64 packed_sint64   =  95 [packed = true];
+  repeated  fixed32 packed_fixed32  =  96 [packed = true];
+  repeated  fixed64 packed_fixed64  =  97 [packed = true];
+  repeated sfixed32 packed_sfixed32 =  98 [packed = true];
+  repeated sfixed64 packed_sfixed64 =  99 [packed = true];
+  repeated    float packed_float    = 100 [packed = true];
+  repeated   double packed_double   = 101 [packed = true];
+  repeated     bool packed_bool     = 102 [packed = true];
+  repeated ForeignEnumLite packed_enum  = 103 [packed = true];
+}
+
+message TestAllExtensionsLite {
+  extensions 1 to max;
+}
+
+extend TestAllExtensionsLite {
+  // Singular
+  optional    int32 optional_int32_extension_lite    =  1;
+  optional    int64 optional_int64_extension_lite    =  2;
+  optional   uint32 optional_uint32_extension_lite   =  3;
+  optional   uint64 optional_uint64_extension_lite   =  4;
+  optional   sint32 optional_sint32_extension_lite   =  5;
+  optional   sint64 optional_sint64_extension_lite   =  6;
+  optional  fixed32 optional_fixed32_extension_lite  =  7;
+  optional  fixed64 optional_fixed64_extension_lite  =  8;
+  optional sfixed32 optional_sfixed32_extension_lite =  9;
+  optional sfixed64 optional_sfixed64_extension_lite = 10;
+  optional    float optional_float_extension_lite    = 11;
+  optional   double optional_double_extension_lite   = 12;
+  optional     bool optional_bool_extension_lite     = 13;
+  optional   string optional_string_extension_lite   = 14;
+  optional    bytes optional_bytes_extension_lite    = 15;
+
+  optional group OptionalGroup_extension_lite = 16 {
+    optional int32 a = 17;
+  }
+
+  optional TestAllTypesLite.NestedMessage optional_nested_message_extension_lite
+      = 18;
+  optional ForeignMessageLite optional_foreign_message_extension_lite = 19;
+  optional protobuf_unittest_import.ImportMessageLite
+    optional_import_message_extension_lite = 20;
+
+  optional TestAllTypesLite.NestedEnum optional_nested_enum_extension_lite = 21;
+  optional ForeignEnumLite optional_foreign_enum_extension_lite = 22;
+  optional protobuf_unittest_import.ImportEnumLite
+    optional_import_enum_extension_lite = 23;
+
+  optional string optional_string_piece_extension_lite = 24
+      [ctype=STRING_PIECE];
+  optional string optional_cord_extension_lite = 25 [ctype=CORD];
+
+  // Repeated
+  repeated    int32 repeated_int32_extension_lite    = 31;
+  repeated    int64 repeated_int64_extension_lite    = 32;
+  repeated   uint32 repeated_uint32_extension_lite   = 33;
+  repeated   uint64 repeated_uint64_extension_lite   = 34;
+  repeated   sint32 repeated_sint32_extension_lite   = 35;
+  repeated   sint64 repeated_sint64_extension_lite   = 36;
+  repeated  fixed32 repeated_fixed32_extension_lite  = 37;
+  repeated  fixed64 repeated_fixed64_extension_lite  = 38;
+  repeated sfixed32 repeated_sfixed32_extension_lite = 39;
+  repeated sfixed64 repeated_sfixed64_extension_lite = 40;
+  repeated    float repeated_float_extension_lite    = 41;
+  repeated   double repeated_double_extension_lite   = 42;
+  repeated     bool repeated_bool_extension_lite     = 43;
+  repeated   string repeated_string_extension_lite   = 44;
+  repeated    bytes repeated_bytes_extension_lite    = 45;
+
+  repeated group RepeatedGroup_extension_lite = 46 {
+    optional int32 a = 47;
+  }
+
+  repeated TestAllTypesLite.NestedMessage repeated_nested_message_extension_lite
+      = 48;
+  repeated ForeignMessageLite repeated_foreign_message_extension_lite = 49;
+  repeated protobuf_unittest_import.ImportMessageLite
+    repeated_import_message_extension_lite = 50;
+
+  repeated TestAllTypesLite.NestedEnum repeated_nested_enum_extension_lite = 51;
+  repeated ForeignEnumLite repeated_foreign_enum_extension_lite = 52;
+  repeated protobuf_unittest_import.ImportEnumLite
+    repeated_import_enum_extension_lite = 53;
+
+  repeated string repeated_string_piece_extension_lite = 54
+      [ctype=STRING_PIECE];
+  repeated string repeated_cord_extension_lite = 55 [ctype=CORD];
+
+  // Singular with defaults
+  optional    int32 default_int32_extension_lite    = 61 [default =  41    ];
+  optional    int64 default_int64_extension_lite    = 62 [default =  42    ];
+  optional   uint32 default_uint32_extension_lite   = 63 [default =  43    ];
+  optional   uint64 default_uint64_extension_lite   = 64 [default =  44    ];
+  optional   sint32 default_sint32_extension_lite   = 65 [default = -45    ];
+  optional   sint64 default_sint64_extension_lite   = 66 [default =  46    ];
+  optional  fixed32 default_fixed32_extension_lite  = 67 [default =  47    ];
+  optional  fixed64 default_fixed64_extension_lite  = 68 [default =  48    ];
+  optional sfixed32 default_sfixed32_extension_lite = 69 [default =  49    ];
+  optional sfixed64 default_sfixed64_extension_lite = 70 [default = -50    ];
+  optional    float default_float_extension_lite    = 71 [default =  51.5  ];
+  optional   double default_double_extension_lite   = 72 [default =  52e3  ];
+  optional     bool default_bool_extension_lite     = 73 [default = true   ];
+  optional   string default_string_extension_lite   = 74 [default = "hello"];
+  optional    bytes default_bytes_extension_lite    = 75 [default = "world"];
+
+  optional TestAllTypesLite.NestedEnum
+    default_nested_enum_extension_lite = 81 [default = BAR];
+  optional ForeignEnumLite
+    default_foreign_enum_extension_lite = 82 [default = FOREIGN_LITE_BAR];
+  optional protobuf_unittest_import.ImportEnumLite
+    default_import_enum_extension_lite = 83 [default = IMPORT_LITE_BAR];
+
+  optional string default_string_piece_extension_lite = 84 [ctype=STRING_PIECE,
+                                                            default="abc"];
+  optional string default_cord_extension_lite = 85 [ctype=CORD, default="123"];
+}
+
+message TestPackedExtensionsLite {
+  extensions 1 to max;
+}
+
+extend TestPackedExtensionsLite {
+  repeated    int32 packed_int32_extension_lite    =  90 [packed = true];
+  repeated    int64 packed_int64_extension_lite    =  91 [packed = true];
+  repeated   uint32 packed_uint32_extension_lite   =  92 [packed = true];
+  repeated   uint64 packed_uint64_extension_lite   =  93 [packed = true];
+  repeated   sint32 packed_sint32_extension_lite   =  94 [packed = true];
+  repeated   sint64 packed_sint64_extension_lite   =  95 [packed = true];
+  repeated  fixed32 packed_fixed32_extension_lite  =  96 [packed = true];
+  repeated  fixed64 packed_fixed64_extension_lite  =  97 [packed = true];
+  repeated sfixed32 packed_sfixed32_extension_lite =  98 [packed = true];
+  repeated sfixed64 packed_sfixed64_extension_lite =  99 [packed = true];
+  repeated    float packed_float_extension_lite    = 100 [packed = true];
+  repeated   double packed_double_extension_lite   = 101 [packed = true];
+  repeated     bool packed_bool_extension_lite     = 102 [packed = true];
+  repeated ForeignEnumLite packed_enum_extension_lite = 103 [packed = true];
+}
+
+message TestNestedExtensionLite {
+  extend TestAllExtensionsLite {
+    optional int32 nested_extension = 12345;
+  }
+}
+
+// Test that deprecated fields work.  We only verify that they compile (at one
+// point this failed).
+message TestDeprecatedLite {
+  optional int32 deprecated_field = 1 [deprecated = true];
+}

protos/google/protobuf/unittest_lite_imports_nonlite.proto

@@ -0,0 +1,49 @@
+// 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

@@ -0,0 +1,60 @@
+// 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

@@ -1,4 +1,4 @@
-// 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/MessageGenerator.cs

@@ -32,6 +32,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
+using System;
 using System.Collections.Generic;
 using Google.ProtocolBuffers.DescriptorProtos;
 using Google.ProtocolBuffers.Descriptors;
@@ -69,12 +70,13 @@ namespace Google.ProtocolBuffers.ProtoGen {
 
       string identifier = GetUniqueFileScopeIdentifier(Descriptor);
 
-      // The descriptor for this type.
-      string access = Descriptor.File.CSharpOptions.NestClasses ? "private" : "internal";
-      writer.WriteLine("{0} static pbd::MessageDescriptor internal__{1}__Descriptor;", access, identifier);
-      writer.WriteLine("{0} static pb::FieldAccess.FieldAccessorTable<{1}, {1}.Builder> internal__{2}__FieldAccessorTable;",
-          access, FullClassName, identifier);
-
+      if (!UseLiteRuntime) {
+        // The descriptor for this type.
+        string access = Descriptor.File.CSharpOptions.NestClasses ? "private" : "internal";
+        writer.WriteLine("{0} static pbd::MessageDescriptor internal__{1}__Descriptor;", access, identifier);
+        writer.WriteLine("{0} static pb::FieldAccess.FieldAccessorTable<{1}, {1}.Builder> internal__{2}__FieldAccessorTable;",
+                         access, FullClassName, identifier);
+      }
       // Generate static members for all nested types.
       foreach (MessageDescriptor nestedMessage in Descriptor.NestedTypes) {
         new MessageGenerator(nestedMessage).GenerateStaticVariables(writer);
@@ -84,21 +86,23 @@ namespace Google.ProtocolBuffers.ProtoGen {
     internal void GenerateStaticVariableInitializers(TextGenerator writer) {
       string identifier = GetUniqueFileScopeIdentifier(Descriptor);
 
-      writer.Write("internal__{0}__Descriptor = ", identifier);
-      if (Descriptor.ContainingType == null) {
-        writer.WriteLine("Descriptor.MessageTypes[{0}];", Descriptor.Index);
-      } else {
-        writer.WriteLine("internal__{0}__Descriptor.NestedTypes[{1}];", GetUniqueFileScopeIdentifier(Descriptor.ContainingType), Descriptor.Index);
-      }
+      if (!UseLiteRuntime) {
+        writer.Write("internal__{0}__Descriptor = ", identifier);
+        if (Descriptor.ContainingType == null) {
+          writer.WriteLine("Descriptor.MessageTypes[{0}];", Descriptor.Index);
+        } else {
+          writer.WriteLine("internal__{0}__Descriptor.NestedTypes[{1}];", GetUniqueFileScopeIdentifier(Descriptor.ContainingType), Descriptor.Index);
+        }
 
-      writer.WriteLine("internal__{0}__FieldAccessorTable = ", identifier);
-      writer.WriteLine("    new pb::FieldAccess.FieldAccessorTable<{1}, {1}.Builder>(internal__{0}__Descriptor,",
-          identifier, FullClassName);
-      writer.Print("        new string[] { ");
-      foreach (FieldDescriptor field in Descriptor.Fields) {
-        writer.Write("\"{0}\", ", field.CSharpOptions.PropertyName);
+        writer.WriteLine("internal__{0}__FieldAccessorTable = ", identifier);
+        writer.WriteLine("    new pb::FieldAccess.FieldAccessorTable<{1}, {1}.Builder>(internal__{0}__Descriptor,",
+                         identifier, FullClassName);
+        writer.Print("        new string[] { ");
+        foreach (FieldDescriptor field in Descriptor.Fields) {
+          writer.Write("\"{0}\", ", field.CSharpOptions.PropertyName);
+        }
+        writer.WriteLine("});");
       }
-      writer.WriteLine("});");
 
       // Generate static member initializers for all nested types.
       foreach (MessageDescriptor nestedMessage in Descriptor.NestedTypes) {
@@ -111,8 +115,10 @@ namespace Google.ProtocolBuffers.ProtoGen {
     }
 
     public void Generate(TextGenerator writer) {
-      writer.WriteLine("{0} sealed partial class {1} : pb::{2}Message<{1}, {1}.Builder> {{",
-          ClassAccessLevel, ClassName, Descriptor.Proto.ExtensionRangeCount > 0 ? "Extendable" : "Generated");
+      writer.WriteLine("{0} sealed partial class {1} : pb::{2}Message{3}<{1}, {1}.Builder> {{",
+          ClassAccessLevel, ClassName, 
+          Descriptor.Proto.ExtensionRangeCount > 0 ? "Extendable" : "Generated",
+          RuntimeSuffix);
       writer.Indent();
       // Must call BuildPartial() to make sure all lists are made read-only
       writer.WriteLine("private static readonly {0} defaultInstance = new Builder().BuildPartial();", ClassName);
@@ -128,16 +134,18 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("  get { return this; }");
       writer.WriteLine("}");
       writer.WriteLine();
-      writer.WriteLine("public static pbd::MessageDescriptor Descriptor {");
-      writer.WriteLine("  get {{ return {0}.internal__{1}__Descriptor; }}", DescriptorUtil.GetFullUmbrellaClassName(Descriptor),
-          GetUniqueFileScopeIdentifier(Descriptor));
-      writer.WriteLine("}");
-      writer.WriteLine();
-      writer.WriteLine("protected override pb::FieldAccess.FieldAccessorTable<{0}, {0}.Builder> InternalFieldAccessors {{", ClassName);
-      writer.WriteLine("  get {{ return {0}.internal__{1}__FieldAccessorTable; }}", DescriptorUtil.GetFullUmbrellaClassName(Descriptor),
-          GetUniqueFileScopeIdentifier(Descriptor));
-      writer.WriteLine("}");
-      writer.WriteLine();
+      if (!UseLiteRuntime) {
+        writer.WriteLine("public static pbd::MessageDescriptor Descriptor {");
+        writer.WriteLine("  get {{ return {0}.internal__{1}__Descriptor; }}", DescriptorUtil.GetFullUmbrellaClassName(Descriptor),
+                         GetUniqueFileScopeIdentifier(Descriptor));
+        writer.WriteLine("}");
+        writer.WriteLine();
+        writer.WriteLine("protected override pb::FieldAccess.FieldAccessorTable<{0}, {0}.Builder> InternalFieldAccessors {{", ClassName);
+        writer.WriteLine("  get {{ return {0}.internal__{1}__FieldAccessorTable; }}", DescriptorUtil.GetFullUmbrellaClassName(Descriptor),
+                         GetUniqueFileScopeIdentifier(Descriptor));
+        writer.WriteLine("}");
+        writer.WriteLine();
+      }
 
       // Extensions don't need to go in an extra nested type 
       WriteChildren(writer, null, Descriptor.Extensions);
@@ -161,10 +169,13 @@ namespace Google.ProtocolBuffers.ProtoGen {
         writer.WriteLine();
       }
 
-      if (Descriptor.File.Options.OptimizeFor == FileOptions.Types.OptimizeMode.SPEED) {
+      if (OptimizeSpeed) {
         GenerateIsInitialized(writer);
         GenerateMessageSerializationMethods(writer);
       }
+      if (UseLiteRuntime) {
+        GenerateLiteRuntimeMethods(writer);
+      }
 
       GenerateParseFromMethods(writer);
       GenerateBuilder(writer);
@@ -184,6 +195,49 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine();
     }
 
+    private void GenerateLiteRuntimeMethods(TextGenerator writer) {
+
+      bool callbase = Descriptor.Proto.ExtensionRangeCount > 0;
+      writer.WriteLine("#region Lite runtime methods");
+      writer.WriteLine("public override int GetHashCode() {");
+      writer.Indent();
+      writer.WriteLine("int hash = GetType().GetHashCode();");
+      foreach (FieldDescriptor fieldDescriptor in Descriptor.Fields) {
+        SourceGenerators.CreateFieldGenerator(fieldDescriptor).WriteHash(writer);
+      }
+      if (callbase) writer.WriteLine("hash ^= base.GetHashCode();");
+      writer.WriteLine("return hash;");
+      writer.Outdent();
+      writer.WriteLine("}");
+      writer.WriteLine();
+
+      writer.WriteLine("public override bool Equals(object obj) {");
+      writer.Indent();
+      writer.WriteLine("{0} other = obj as {0};", ClassName);
+      writer.WriteLine("if (other == null) return false;");
+      foreach (FieldDescriptor fieldDescriptor in Descriptor.Fields) {
+        SourceGenerators.CreateFieldGenerator(fieldDescriptor).WriteEquals(writer);
+      }
+      if (callbase) writer.WriteLine("if (!base.Equals(other)) return false;");
+      writer.WriteLine("return true;");
+      writer.Outdent();
+      writer.WriteLine("}");
+      writer.WriteLine();
+      
+      writer.WriteLine("public override void PrintTo(global::System.IO.TextWriter writer) {");
+      writer.Indent();
+      List<FieldDescriptor> sorted = new List<FieldDescriptor>(Descriptor.Fields);
+      sorted.Sort(new Comparison<FieldDescriptor>(delegate(FieldDescriptor a, FieldDescriptor b) { return a.FieldNumber.CompareTo(b.FieldNumber); }));
+      foreach (FieldDescriptor fieldDescriptor in sorted) {
+        SourceGenerators.CreateFieldGenerator(fieldDescriptor).WriteToString(writer);
+      }
+      if (callbase) writer.WriteLine("base.PrintTo(writer);");
+      writer.Outdent();
+      writer.WriteLine("}");
+      writer.WriteLine("#endregion");
+      writer.WriteLine();
+    }
+
     private void GenerateMessageSerializationMethods(TextGenerator writer) {
       List<FieldDescriptor> sortedFields = new List<FieldDescriptor>(Descriptor.Fields);
       sortedFields.Sort((f1, f2) => f1.FieldNumber.CompareTo(f2.FieldNumber));
@@ -196,8 +250,8 @@ namespace Google.ProtocolBuffers.ProtoGen {
       // Make sure we've computed the serialized length, so that packed fields are generated correctly.
       writer.WriteLine("int size = SerializedSize;");
       if (Descriptor.Proto.ExtensionRangeList.Count > 0) {
-        writer.WriteLine("pb::ExtendableMessage<{0}, {0}.Builder>.ExtensionWriter extensionWriter = CreateExtensionWriter(this);",
-          ClassName);
+        writer.WriteLine("pb::ExtendableMessage{1}<{0}, {0}.Builder>.ExtensionWriter extensionWriter = CreateExtensionWriter(this);",
+          ClassName, RuntimeSuffix);
       }
 
       // Merge the fields and the extension ranges, both sorted by field number.
@@ -213,10 +267,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
         }
       }
 
-      if (Descriptor.Proto.Options.MessageSetWireFormat) {
-        writer.WriteLine("UnknownFields.WriteAsMessageSetTo(output);");
-      } else {
-        writer.WriteLine("UnknownFields.WriteTo(output);");
+      if (!UseLiteRuntime) {
+        if (Descriptor.Proto.Options.MessageSetWireFormat) {
+          writer.WriteLine("UnknownFields.WriteAsMessageSetTo(output);");
+        } else {
+          writer.WriteLine("UnknownFields.WriteTo(output);");
+        }
       }
 
       writer.Outdent();
@@ -238,10 +294,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
         writer.WriteLine("size += ExtensionsSerializedSize;");
       }
 
-      if (Descriptor.Options.MessageSetWireFormat) {
-        writer.WriteLine("size += UnknownFields.SerializedSizeAsMessageSet;");
-      } else {
-        writer.WriteLine("size += UnknownFields.SerializedSize;");
+      if (!UseLiteRuntime) {
+        if (Descriptor.Options.MessageSetWireFormat) {
+          writer.WriteLine("size += UnknownFields.SerializedSizeAsMessageSet;");
+        } else {
+          writer.WriteLine("size += UnknownFields.SerializedSize;");
+        }
       }
       writer.WriteLine("memoizedSerializedSize = size;");
       writer.WriteLine("return size;");
@@ -345,14 +403,14 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("  return (Builder) new Builder().MergeFrom(prototype);");
       writer.WriteLine("}");
       writer.WriteLine();
-      writer.WriteLine("{0} sealed partial class Builder : pb::{2}Builder<{1}, Builder> {{",
-          ClassAccessLevel, ClassName, Descriptor.Proto.ExtensionRangeCount > 0 ? "Extendable" : "Generated");
+      writer.WriteLine("{0} sealed partial class Builder : pb::{2}Builder{3}<{1}, Builder> {{",
+          ClassAccessLevel, ClassName, Descriptor.Proto.ExtensionRangeCount > 0 ? "Extendable" : "Generated", RuntimeSuffix);
       writer.Indent();
       writer.WriteLine("protected override Builder ThisBuilder {");
       writer.WriteLine("  get { return this; }");
       writer.WriteLine("}");
       GenerateCommonBuilderMethods(writer);
-      if (Descriptor.File.Options.OptimizeFor == FileOptions.Types.OptimizeMode.SPEED) {
+      if (OptimizeSpeed) {
         GenerateBuilderParsingMethods(writer);
       }
       foreach (FieldDescriptor field in Descriptor.Fields) {
@@ -382,10 +440,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("  return new Builder().MergeFrom(result);");
       writer.WriteLine("}");
       writer.WriteLine();
-      writer.WriteLine("public override pbd::MessageDescriptor DescriptorForType {");
-      writer.WriteLine("  get {{ return {0}.Descriptor; }}", FullClassName);
-      writer.WriteLine("}");
-      writer.WriteLine();
+      if (!UseLiteRuntime) {
+        writer.WriteLine("public override pbd::MessageDescriptor DescriptorForType {");
+        writer.WriteLine("  get {{ return {0}.Descriptor; }}", FullClassName);
+        writer.WriteLine("}");
+        writer.WriteLine();
+      }
       writer.WriteLine("public override {0} DefaultInstanceForType {{", ClassName);
       writer.WriteLine("  get {{ return {0}.DefaultInstance; }}", FullClassName);
       writer.WriteLine("}");
@@ -406,8 +466,8 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("}");
       writer.WriteLine();
 
-      if (Descriptor.File.Options.OptimizeFor == FileOptions.Types.OptimizeMode.SPEED) {
-        writer.WriteLine("public override Builder MergeFrom(pb::IMessage other) {");
+      if (OptimizeSpeed) {
+        writer.WriteLine("public override Builder MergeFrom(pb::IMessage{0} other) {{", RuntimeSuffix);
         writer.WriteLine("  if (other is {0}) {{", ClassName);
         writer.WriteLine("    return MergeFrom(({0}) other);", ClassName);
         writer.WriteLine("  } else {");
@@ -428,7 +488,9 @@ namespace Google.ProtocolBuffers.ProtoGen {
         if (Descriptor.Proto.ExtensionRangeCount > 0) {
           writer.WriteLine("  this.MergeExtensionFields(other);");
         }
-        writer.WriteLine("this.MergeUnknownFields(other.UnknownFields);");
+        if (!UseLiteRuntime) {
+          writer.WriteLine("this.MergeUnknownFields(other.UnknownFields);");
+        }
         writer.WriteLine("return this;");
         writer.Outdent();
         writer.WriteLine("}");
@@ -446,29 +508,37 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine();
       writer.WriteLine("public override Builder MergeFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {");
       writer.Indent();
-      writer.WriteLine("pb::UnknownFieldSet.Builder unknownFields = null;");
+      if (!UseLiteRuntime) {
+        writer.WriteLine("pb::UnknownFieldSet.Builder unknownFields = null;");
+      }
       writer.WriteLine("while (true) {");
       writer.Indent();
       writer.WriteLine("uint tag = input.ReadTag();");
       writer.WriteLine("switch (tag) {");
       writer.Indent();
       writer.WriteLine("case 0: {"); // 0 signals EOF / limit reached
-      writer.WriteLine("  if (unknownFields != null) {");
-      writer.WriteLine("    this.UnknownFields = unknownFields.Build();");
-      writer.WriteLine("  }");
+      if (!UseLiteRuntime) {
+        writer.WriteLine("  if (unknownFields != null) {");
+        writer.WriteLine("    this.UnknownFields = unknownFields.Build();");
+        writer.WriteLine("  }");
+      }
       writer.WriteLine("  return this;");
       writer.WriteLine("}");
       writer.WriteLine("default: {");
       writer.WriteLine("  if (pb::WireFormat.IsEndGroupTag(tag)) {");
-      writer.WriteLine("    if (unknownFields != null) {");
-      writer.WriteLine("      this.UnknownFields = unknownFields.Build();");
-      writer.WriteLine("    }");
+      if (!UseLiteRuntime) {
+        writer.WriteLine("    if (unknownFields != null) {");
+        writer.WriteLine("      this.UnknownFields = unknownFields.Build();");
+        writer.WriteLine("    }");
+      }
       writer.WriteLine("    return this;"); // it's an endgroup tag
       writer.WriteLine("  }");
-      writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
-      writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
-      writer.WriteLine("  }");
-      writer.WriteLine("  ParseUnknownField(input, unknownFields, extensionRegistry, tag);");
+      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("  ParseUnknownField(input, {0}extensionRegistry, tag);", UseLiteRuntime ? "" : "unknownFields, ");
       writer.WriteLine("  break;");
       writer.WriteLine("}");
       foreach (FieldDescriptor field in sortedFields) {

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/ExtendableMessageTest.cs

@@ -0,0 +1,192 @@
+#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 Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class ExtendableMessageTest {
+
+    [Test, ExpectedException(typeof(ArgumentException))]
+    public void ExtensionWriterInvalidExtension() {
+      TestPackedExtensions.CreateBuilder()[UnitTestProtoFile.OptionalForeignMessageExtension.Descriptor] =
+        ForeignMessage.DefaultInstance;
+    }
+
+    [Test]
+    public void ExtensionWriterTest() {
+      TestAllExtensions.Builder builder = TestAllExtensions.CreateBuilder()
+        .SetExtension(UnitTestProtoFile.DefaultBoolExtension, true)
+        .SetExtension(UnitTestProtoFile.DefaultBytesExtension, ByteString.CopyFromUtf8("123"))
+        .SetExtension(UnitTestProtoFile.DefaultCordExtension, "123")
+        .SetExtension(UnitTestProtoFile.DefaultDoubleExtension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultFixed32Extension, 123u)
+        .SetExtension(UnitTestProtoFile.DefaultFixed64Extension, 123u)
+        .SetExtension(UnitTestProtoFile.DefaultFloatExtension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
+        .SetExtension(UnitTestProtoFile.DefaultImportEnumExtension, ImportEnum.IMPORT_BAZ)
+        .SetExtension(UnitTestProtoFile.DefaultInt32Extension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultInt64Extension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
+        .SetExtension(UnitTestProtoFile.DefaultSfixed32Extension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultSfixed64Extension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultSint32Extension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultSint64Extension, 123)
+        .SetExtension(UnitTestProtoFile.DefaultStringExtension, "123")
+        .SetExtension(UnitTestProtoFile.DefaultStringPieceExtension, "123")
+        .SetExtension(UnitTestProtoFile.DefaultUint32Extension, 123u)
+        .SetExtension(UnitTestProtoFile.DefaultUint64Extension, 123u)
+        //Optional
+        .SetExtension(UnitTestProtoFile.OptionalBoolExtension, true)
+        .SetExtension(UnitTestProtoFile.OptionalBytesExtension, ByteString.CopyFromUtf8("123"))
+        .SetExtension(UnitTestProtoFile.OptionalCordExtension, "123")
+        .SetExtension(UnitTestProtoFile.OptionalDoubleExtension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalFixed32Extension, 123u)
+        .SetExtension(UnitTestProtoFile.OptionalFixed64Extension, 123u)
+        .SetExtension(UnitTestProtoFile.OptionalFloatExtension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
+        .SetExtension(UnitTestProtoFile.OptionalImportEnumExtension, ImportEnum.IMPORT_BAZ)
+        .SetExtension(UnitTestProtoFile.OptionalInt32Extension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalInt64Extension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
+        .SetExtension(UnitTestProtoFile.OptionalSfixed32Extension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalSfixed64Extension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalSint32Extension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalSint64Extension, 123)
+        .SetExtension(UnitTestProtoFile.OptionalStringExtension, "123")
+        .SetExtension(UnitTestProtoFile.OptionalStringPieceExtension, "123")
+        .SetExtension(UnitTestProtoFile.OptionalUint32Extension, 123u)
+        .SetExtension(UnitTestProtoFile.OptionalUint64Extension, 123u)
+        //Repeated
+        .AddExtension(UnitTestProtoFile.RepeatedBoolExtension, true)
+        .AddExtension(UnitTestProtoFile.RepeatedBytesExtension, ByteString.CopyFromUtf8("123"))
+        .AddExtension(UnitTestProtoFile.RepeatedCordExtension, "123")
+        .AddExtension(UnitTestProtoFile.RepeatedDoubleExtension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedFixed32Extension, 123u)
+        .AddExtension(UnitTestProtoFile.RepeatedFixed64Extension, 123u)
+        .AddExtension(UnitTestProtoFile.RepeatedFloatExtension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedForeignEnumExtension, ForeignEnum.FOREIGN_BAZ)
+        .AddExtension(UnitTestProtoFile.RepeatedImportEnumExtension, ImportEnum.IMPORT_BAZ)
+        .AddExtension(UnitTestProtoFile.RepeatedInt32Extension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedInt64Extension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedNestedEnumExtension, TestAllTypes.Types.NestedEnum.FOO)
+        .AddExtension(UnitTestProtoFile.RepeatedSfixed32Extension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedSfixed64Extension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedSint32Extension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedSint64Extension, 123)
+        .AddExtension(UnitTestProtoFile.RepeatedStringExtension, "123")
+        .AddExtension(UnitTestProtoFile.RepeatedStringPieceExtension, "123")
+        .AddExtension(UnitTestProtoFile.RepeatedUint32Extension, 123u)
+        .AddExtension(UnitTestProtoFile.RepeatedUint64Extension, 123u)
+        ;
+      TestAllExtensions msg = builder.Build();
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestProtoFile.RegisterAllExtensions(registry);
+
+      TestAllExtensions.Builder copyBuilder = TestAllExtensions.CreateBuilder().MergeFrom(msg.ToByteArray(), registry);
+      TestAllExtensions copy = copyBuilder.Build();
+
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.DefaultBoolExtension));
+      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.DefaultBytesExtension));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultCordExtension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultDoubleExtension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultFixed32Extension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultFixed64Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultFloatExtension));
+      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.DefaultForeignEnumExtension));
+      Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.DefaultImportEnumExtension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultInt32Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultInt64Extension));
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, copy.GetExtension(UnitTestProtoFile.DefaultNestedEnumExtension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSfixed32Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSfixed64Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSint32Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.DefaultSint64Extension));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultStringExtension));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.DefaultStringPieceExtension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultUint32Extension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.DefaultUint64Extension));
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.OptionalBoolExtension));
+      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.OptionalBytesExtension));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalCordExtension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalDoubleExtension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalFixed32Extension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalFixed64Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalFloatExtension));
+      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.OptionalForeignEnumExtension));
+      Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.OptionalImportEnumExtension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalInt32Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalInt64Extension));
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, copy.GetExtension(UnitTestProtoFile.OptionalNestedEnumExtension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSfixed32Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSfixed64Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSint32Extension));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.OptionalSint64Extension));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalStringExtension));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.OptionalStringPieceExtension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalUint32Extension));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.OptionalUint64Extension));
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestProtoFile.RepeatedBoolExtension, 0));
+      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestProtoFile.RepeatedBytesExtension, 0));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedCordExtension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedDoubleExtension, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedFixed32Extension, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedFixed64Extension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedFloatExtension, 0));
+      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, copy.GetExtension(UnitTestProtoFile.RepeatedForeignEnumExtension, 0));
+      Assert.AreEqual(ImportEnum.IMPORT_BAZ, copy.GetExtension(UnitTestProtoFile.RepeatedImportEnumExtension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedInt32Extension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedInt64Extension, 0));
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, copy.GetExtension(UnitTestProtoFile.RepeatedNestedEnumExtension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSfixed32Extension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSfixed64Extension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSint32Extension, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestProtoFile.RepeatedSint64Extension, 0));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedStringExtension, 0));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestProtoFile.RepeatedStringPieceExtension, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedUint32Extension, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestProtoFile.RepeatedUint64Extension, 0));
+    }
+
+  }
+}

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

@@ -1,4 +1,4 @@
-// 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/UnitTestCustomOptionsProtoFile.cs

@@ -1,4 +1,4 @@
-// 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;
@@ -15,6 +15,7 @@ namespace Google.ProtocolBuffers.TestProtos {
       registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.FieldOpt1);
       registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.FieldOpt2);
       registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.EnumOpt1);
+      registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.EnumValueOpt1);
       registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ServiceOpt1);
       registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.MethodOpt1);
       registry.Add(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.BoolOpt);
@@ -58,6 +59,8 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static pb::GeneratedExtensionBase<int> FieldOpt2;
     public const int EnumOpt1FieldNumber = 7753576;
     public static pb::GeneratedExtensionBase<int> EnumOpt1;
+    public const int EnumValueOpt1FieldNumber = 1560678;
+    public static pb::GeneratedExtensionBase<int> EnumValueOpt1;
     public const int ServiceOpt1FieldNumber = 7887650;
     public static pb::GeneratedExtensionBase<long> ServiceOpt1;
     public const int MethodOpt1FieldNumber = 7890860;
@@ -165,97 +168,99 @@ namespace Google.ProtocolBuffers.TestProtos {
           "Ci1nb29nbGUvcHJvdG9idWYvdW5pdHRlc3RfY3VzdG9tX29wdGlvbnMucHJv" + 
           "dG8SEXByb3RvYnVmX3VuaXR0ZXN0GiRnb29nbGUvcHJvdG9idWYvY3NoYXJw" + 
           "X29wdGlvbnMucHJvdG8aIGdvb2dsZS9wcm90b2J1Zi9kZXNjcmlwdG9yLnBy" + 
-          "b3RvIoYBChxUZXN0TWVzc2FnZVdpdGhDdXN0b21PcHRpb25zEh4KBmZpZWxk" + 
-          "MRgBIAEoCUIOCAHB4MMdLeF1CgIAAAAiNAoGQW5FbnVtEg8KC0FORU5VTV9W" + 
-          "QUwxEAESDwoLQU5FTlVNX1ZBTDIQAhoIxfbJHev8//86EAgA4OnCHcj/////" + 
-          "/////wEiGAoWQ3VzdG9tT3B0aW9uRm9vUmVxdWVzdCIZChdDdXN0b21PcHRp" + 
-          "b25Gb29SZXNwb25zZSJtChpEdW1teU1lc3NhZ2VDb250YWluaW5nRW51bSJP" + 
-          "CgxUZXN0RW51bVR5cGUSGgoWVEVTVF9PUFRJT05fRU5VTV9UWVBFMRAWEiMK" + 
-          "FlRFU1RfT1BUSU9OX0VOVU1fVFlQRTIQ6f//////////ASIhCh9EdW1teU1l" + 
-          "c3NhZ2VJbnZhbGlkQXNPcHRpb25UeXBlIooBChxDdXN0b21PcHRpb25NaW5J" + 
-          "bnRlZ2VyVmFsdWVzOmqZ1qgdAAAAAAAAAICtja8dAAAAgJHurx0AAAAAAAAA" + 
-          "AJ31rx0AAAAA+JewHf///////////wGAxLAd/////w/49bAdAICTsh0AsLyy" + 
-          "HYCAgICAgICAgAHoxrIdgICAgPj/////AdDesh0AIpEBChxDdXN0b21PcHRp" + 
-          "b25NYXhJbnRlZ2VyVmFsdWVzOnGZ1qgd/////////3+tja8d////f5Hurx3/" + 
-          "/////////531rx3/////+JewHf7//////////wGAxLAd/v///w/49bAd////" + 
-          "////////AYCTsh3/////D7C8sh3//////////3/oxrId/////wfQ3rIdASJu" + 
-          "ChdDdXN0b21PcHRpb25PdGhlclZhbHVlczpTiNmiHen//////////wGy2aId" + 
-          "C0hlbGxvAFdvcmxkqtyiHQ5IZWxsbywgIldvcmxkIuncoh37WYxCysDzP/Xf" + 
-          "ox3nh0VB6MayHZz//////////wEiNAocU2V0dGluZ1JlYWxzRnJvbVBvc2l0" + 
-          "aXZlSW50czoU6dyiHQAAAAAAQGNA9d+jHQAAQEEiNAocU2V0dGluZ1JlYWxz" + 
-          "RnJvbU5lZ2F0aXZlSW50czoU6dyiHQAAAAAAQGPA9d+jHQAAQMEiKwoSQ29t" + 
-          "cGxleE9wdGlvblR5cGUxEgsKA2ZvbxgBIAEoBSoICGQQgICAgAIiwQIKEkNv" + 
-          "bXBsZXhPcHRpb25UeXBlMhIyCgNiYXIYASABKAsyJS5wcm90b2J1Zl91bml0" + 
-          "dGVzdC5Db21wbGV4T3B0aW9uVHlwZTESCwoDYmF6GAIgASgFEkYKBGZyZWQY" + 
-          "AyABKAsyOC5wcm90b2J1Zl91bml0dGVzdC5Db21wbGV4T3B0aW9uVHlwZTIu" + 
-          "Q29tcGxleE9wdGlvblR5cGU0GpcBChJDb21wbGV4T3B0aW9uVHlwZTQSDQoF" + 
-          "d2FsZG8YASABKAUycgoMY29tcGxleF9vcHQ0Eh8uZ29vZ2xlLnByb3RvYnVm" + 
-          "Lk1lc3NhZ2VPcHRpb25zGIr10QMgASgLMjgucHJvdG9idWZfdW5pdHRlc3Qu" + 
-          "Q29tcGxleE9wdGlvblR5cGUyLkNvbXBsZXhPcHRpb25UeXBlNCoICGQQgICA" + 
-          "gAIinAEKEkNvbXBsZXhPcHRpb25UeXBlMxILCgNxdXgYASABKAUSVAoSY29t" + 
-          "cGxleG9wdGlvbnR5cGU1GAIgASgKMjgucHJvdG9idWZfdW5pdHRlc3QuQ29t" + 
-          "cGxleE9wdGlvblR5cGUzLkNvbXBsZXhPcHRpb25UeXBlNRojChJDb21wbGV4" + 
-          "T3B0aW9uVHlwZTUSDQoFcGx1Z2gYAyABKAUiHwoLQ29tcGxleE9wdDYSEAoF" + 
-          "eHl6enkY37/PAyABKAUi0AEKFVZhcmlvdXNDb21wbGV4T3B0aW9uczq2AePc" + 
-          "/Bz4/fscGOTc/BzSqI8dAwizD/rekB0CCAn63pAdBBMYFhSq/ZAdAxDbB6r9" + 
-          "kB0G+OaXHY4Fqv2QHQUKAwjnBar9kB0ICgbYhZ4dzw+q/ZAdCgoIkvWdHQMI" + 
-          "2A+q/ZAdCMKslx0DCOUFqv2QHQvCrJcdBtiFnh3OD6r9kB0NwqyXHQiS9Z0d" + 
-          "AwjJEKr9kB0FGgMIwQKi4pUdAggqouKVHQbYhZ4dxAKi4pUdCJL1nR0DCOwG" + 
-          "KjYKCk1ldGhvZE9wdDESEwoPTUVUSE9ET1BUMV9WQUwxEAESEwoPTUVUSE9E" + 
-          "T1BUMV9WQUwyEAIyjgEKHFRlc3RTZXJ2aWNlV2l0aEN1c3RvbU9wdGlvbnMS" + 
-          "YwoDRm9vEikucHJvdG9idWZfdW5pdHRlc3QuQ3VzdG9tT3B0aW9uRm9vUmVx" + 
-          "dWVzdBoqLnByb3RvYnVmX3VuaXR0ZXN0LkN1c3RvbU9wdGlvbkZvb1Jlc3Bv" + 
-          "bnNlIgXg+oweAhoJkLKLHtPbgMtJOjIKCWZpbGVfb3B0MRIcLmdvb2dsZS5w" + 
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       pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {
         descriptor = root;
         internal__static_protobuf_unittest_TestMessageWithCustomOptions__Descriptor = Descriptor.MessageTypes[0];
@@ -301,7 +306,7 @@ namespace Google.ProtocolBuffers.TestProtos {
         internal__static_protobuf_unittest_ComplexOptionType1__Descriptor = Descriptor.MessageTypes[10];
         internal__static_protobuf_unittest_ComplexOptionType1__FieldAccessorTable = 
             new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1, global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1.Builder>(internal__static_protobuf_unittest_ComplexOptionType1__Descriptor,
-                new string[] { "Foo", });
+                new string[] { "Foo", "Foo2", "Foo3", });
         internal__static_protobuf_unittest_ComplexOptionType2__Descriptor = Descriptor.MessageTypes[11];
         internal__static_protobuf_unittest_ComplexOptionType2__FieldAccessorTable = 
             new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType2, global::Google.ProtocolBuffers.TestProtos.ComplexOptionType2.Builder>(internal__static_protobuf_unittest_ComplexOptionType2__Descriptor,
@@ -332,33 +337,34 @@ namespace Google.ProtocolBuffers.TestProtos {
         global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.FieldOpt1 = pb::GeneratedSingleExtension<ulong>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[2]);
         global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.FieldOpt2 = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[3]);
         global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.EnumOpt1 = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[4]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ServiceOpt1 = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[5]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.MethodOpt1 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.MethodOpt1>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[6]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.BoolOpt = pb::GeneratedSingleExtension<bool>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[7]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Int32Opt = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[8]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Int64Opt = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[9]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Uint32Opt = pb::GeneratedSingleExtension<uint>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[10]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Uint64Opt = pb::GeneratedSingleExtension<ulong>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[11]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sint32Opt = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[12]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sint64Opt = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[13]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Fixed32Opt = pb::GeneratedSingleExtension<uint>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[14]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Fixed64Opt = pb::GeneratedSingleExtension<ulong>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[15]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sfixed32Opt = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[16]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sfixed64Opt = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[17]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.FloatOpt = pb::GeneratedSingleExtension<float>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[18]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.DoubleOpt = pb::GeneratedSingleExtension<double>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[19]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.StringOpt = pb::GeneratedSingleExtension<string>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[20]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.BytesOpt = pb::GeneratedSingleExtension<pb::ByteString>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[21]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.EnumOpt = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.DummyMessageContainingEnum.Types.TestEnumType>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[22]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.MessageTypeOpt = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.DummyMessageInvalidAsOptionType>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[23]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Quux = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[24]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Corge = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType3>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[25]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Grault = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[26]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Garply = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[27]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt1 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[28]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt2 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType2>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[29]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt3 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType3>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[30]);
-        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt6 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOpt6>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[31]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.EnumValueOpt1 = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[5]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ServiceOpt1 = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[6]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.MethodOpt1 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.MethodOpt1>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[7]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.BoolOpt = pb::GeneratedSingleExtension<bool>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[8]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Int32Opt = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[9]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Int64Opt = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[10]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Uint32Opt = pb::GeneratedSingleExtension<uint>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[11]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Uint64Opt = pb::GeneratedSingleExtension<ulong>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[12]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sint32Opt = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[13]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sint64Opt = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[14]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Fixed32Opt = pb::GeneratedSingleExtension<uint>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[15]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Fixed64Opt = pb::GeneratedSingleExtension<ulong>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[16]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sfixed32Opt = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[17]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Sfixed64Opt = pb::GeneratedSingleExtension<long>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[18]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.FloatOpt = pb::GeneratedSingleExtension<float>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[19]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.DoubleOpt = pb::GeneratedSingleExtension<double>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[20]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.StringOpt = pb::GeneratedSingleExtension<string>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[21]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.BytesOpt = pb::GeneratedSingleExtension<pb::ByteString>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[22]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.EnumOpt = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.DummyMessageContainingEnum.Types.TestEnumType>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[23]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.MessageTypeOpt = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.DummyMessageInvalidAsOptionType>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[24]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Quux = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[25]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Corge = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType3>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[26]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Grault = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[27]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Garply = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[28]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt1 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[29]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt2 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType2>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[30]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt3 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOptionType3>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[31]);
+        global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.ComplexOpt6 = pb::GeneratedSingleExtension<global::Google.ProtocolBuffers.TestProtos.ComplexOpt6>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor.Extensions[32]);
         pb::ExtensionRegistry registry = pb::ExtensionRegistry.CreateInstance();
         RegisterAllExtensions(registry);
         global::Google.ProtocolBuffers.DescriptorProtos.CSharpOptions.RegisterAllExtensions(registry);
@@ -2217,6 +2223,26 @@ namespace Google.ProtocolBuffers.TestProtos {
       get { return foo_; }
     }
     
+    public const int Foo2FieldNumber = 2;
+    private bool hasFoo2;
+    private int foo2_ = 0;
+    public bool HasFoo2 {
+      get { return hasFoo2; }
+    }
+    public int Foo2 {
+      get { return foo2_; }
+    }
+    
+    public const int Foo3FieldNumber = 3;
+    private bool hasFoo3;
+    private int foo3_ = 0;
+    public bool HasFoo3 {
+      get { return hasFoo3; }
+    }
+    public int Foo3 {
+      get { return foo3_; }
+    }
+    
     public override bool IsInitialized {
       get {
         if (!ExtensionsAreInitialized) return false;
@@ -2230,6 +2256,12 @@ namespace Google.ProtocolBuffers.TestProtos {
       if (HasFoo) {
         output.WriteInt32(1, Foo);
       }
+      if (HasFoo2) {
+        output.WriteInt32(2, Foo2);
+      }
+      if (HasFoo3) {
+        output.WriteInt32(3, Foo3);
+      }
       extensionWriter.WriteUntil(536870912, output);
       UnknownFields.WriteTo(output);
     }
@@ -2244,6 +2276,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         if (HasFoo) {
           size += pb::CodedOutputStream.ComputeInt32Size(1, Foo);
         }
+        if (HasFoo2) {
+          size += pb::CodedOutputStream.ComputeInt32Size(2, Foo2);
+        }
+        if (HasFoo3) {
+          size += pb::CodedOutputStream.ComputeInt32Size(3, Foo3);
+        }
         size += ExtensionsSerializedSize;
         size += UnknownFields.SerializedSize;
         memoizedSerializedSize = size;
@@ -2339,6 +2377,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         if (other == global::Google.ProtocolBuffers.TestProtos.ComplexOptionType1.DefaultInstance) return this;
         if (other.HasFoo) {
           Foo = other.Foo;
+        }
+        if (other.HasFoo2) {
+          Foo2 = other.Foo2;
+        }
+        if (other.HasFoo3) {
+          Foo3 = other.Foo3;
         }
           this.MergeExtensionFields(other);
         this.MergeUnknownFields(other.UnknownFields);
@@ -2377,6 +2421,14 @@ namespace Google.ProtocolBuffers.TestProtos {
               Foo = input.ReadInt32();
               break;
             }
+            case 16: {
+              Foo2 = input.ReadInt32();
+              break;
+            }
+            case 24: {
+              Foo3 = input.ReadInt32();
+              break;
+            }
           }
         }
       }
@@ -2399,6 +2451,42 @@ namespace Google.ProtocolBuffers.TestProtos {
         result.foo_ = 0;
         return this;
       }
+      
+      public bool HasFoo2 {
+        get { return result.HasFoo2; }
+      }
+      public int Foo2 {
+        get { return result.Foo2; }
+        set { SetFoo2(value); }
+      }
+      public Builder SetFoo2(int value) {
+        result.hasFoo2 = true;
+        result.foo2_ = value;
+        return this;
+      }
+      public Builder ClearFoo2() {
+        result.hasFoo2 = false;
+        result.foo2_ = 0;
+        return this;
+      }
+      
+      public bool HasFoo3 {
+        get { return result.HasFoo3; }
+      }
+      public int Foo3 {
+        get { return result.Foo3; }
+        set { SetFoo3(value); }
+      }
+      public Builder SetFoo3(int value) {
+        result.hasFoo3 = true;
+        result.foo3_ = value;
+        return this;
+      }
+      public Builder ClearFoo3() {
+        result.hasFoo3 = false;
+        result.foo3_ = 0;
+        return this;
+      }
     }
     static ComplexOptionType1() {
       object.ReferenceEquals(global::Google.ProtocolBuffers.TestProtos.UnitTestCustomOptionsProtoFile.Descriptor, null);

src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs

@@ -1,4 +1,4 @@
-// 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

@@ -0,0 +1,44 @@
+// 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

@@ -0,0 +1,196 @@
+// 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

@@ -1,4 +1,4 @@
-// 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

@@ -1,4 +1,4 @@
-// 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/UnitTestNoGenericServicesProtoFile.cs

@@ -0,0 +1,382 @@
+// 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.NoGenericService {
+  
+  public static partial class UnitTestNoGenericServicesProtoFile {
+  
+    #region Extension registration
+    public static void RegisterAllExtensions(pb::ExtensionRegistry registry) {
+      registry.Add(global::Google.ProtocolBuffers.TestProtos.NoGenericService.UnitTestNoGenericServicesProtoFile.TestExtension);
+    }
+    #endregion
+    #region Extensions
+    public const int TestExtensionFieldNumber = 1000;
+    public static pb::GeneratedExtensionBase<int> TestExtension;
+    #endregion
+    
+    #region Static variables
+    internal static pbd::MessageDescriptor internal__static_google_protobuf_no_generic_services_test_TestMessage__Descriptor;
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage, global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.Builder> internal__static_google_protobuf_no_generic_services_test_TestMessage__FieldAccessorTable;
+    #endregion
+    #region Descriptor
+    public static pbd::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbd::FileDescriptor descriptor;
+    
+    static UnitTestNoGenericServicesProtoFile() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          "CjJnb29nbGUvcHJvdG9idWYvdW5pdHRlc3Rfbm9fZ2VuZXJpY19zZXJ2aWNl" + 
+          "cy5wcm90bxIoZ29vZ2xlLnByb3RvYnVmLm5vX2dlbmVyaWNfc2VydmljZXNf" + 
+          "dGVzdBokZ29vZ2xlL3Byb3RvYnVmL2NzaGFycF9vcHRpb25zLnByb3RvIiMK" + 
+          "C1Rlc3RNZXNzYWdlEgkKAWEYASABKAUqCQjoBxCAgICAAioTCghUZXN0RW51" + 
+          "bRIHCgNGT08QATKCAQoLVGVzdFNlcnZpY2UScwoDRm9vEjUuZ29vZ2xlLnBy" + 
+          "b3RvYnVmLm5vX2dlbmVyaWNfc2VydmljZXNfdGVzdC5UZXN0TWVzc2FnZRo1" + 
+          "Lmdvb2dsZS5wcm90b2J1Zi5ub19nZW5lcmljX3NlcnZpY2VzX3Rlc3QuVGVz" + 
+          "dE1lc3NhZ2U6TgoOdGVzdF9leHRlbnNpb24SNS5nb29nbGUucHJvdG9idWYu" + 
+          "bm9fZ2VuZXJpY19zZXJ2aWNlc190ZXN0LlRlc3RNZXNzYWdlGOgHIAEoBUJk" + 
+          "gAEAiAEAkAEAwj5YCjJHb29nbGUuUHJvdG9jb2xCdWZmZXJzLlRlc3RQcm90" + 
+          "b3MuTm9HZW5lcmljU2VydmljZRIiVW5pdFRlc3ROb0dlbmVyaWNTZXJ2aWNl" + 
+          "c1Byb3RvRmlsZQ==");
+      pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {
+        descriptor = root;
+        internal__static_google_protobuf_no_generic_services_test_TestMessage__Descriptor = Descriptor.MessageTypes[0];
+        internal__static_google_protobuf_no_generic_services_test_TestMessage__FieldAccessorTable = 
+            new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage, global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.Builder>(internal__static_google_protobuf_no_generic_services_test_TestMessage__Descriptor,
+                new string[] { "A", });
+        global::Google.ProtocolBuffers.TestProtos.NoGenericService.UnitTestNoGenericServicesProtoFile.TestExtension = pb::GeneratedSingleExtension<int>.CreateInstance(global::Google.ProtocolBuffers.TestProtos.NoGenericService.UnitTestNoGenericServicesProtoFile.Descriptor.Extensions[0]);
+        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 TestEnum {
+    FOO = 1,
+  }
+  
+  #endregion
+  
+  #region Messages
+  public sealed partial class TestMessage : pb::ExtendableMessage<TestMessage, TestMessage.Builder> {
+    private static readonly TestMessage defaultInstance = new Builder().BuildPartial();
+    public static TestMessage DefaultInstance {
+      get { return defaultInstance; }
+    }
+    
+    public override TestMessage DefaultInstanceForType {
+      get { return defaultInstance; }
+    }
+    
+    protected override TestMessage ThisMessage {
+      get { return this; }
+    }
+    
+    public static pbd::MessageDescriptor Descriptor {
+      get { return global::Google.ProtocolBuffers.TestProtos.NoGenericService.UnitTestNoGenericServicesProtoFile.internal__static_google_protobuf_no_generic_services_test_TestMessage__Descriptor; }
+    }
+    
+    protected override pb::FieldAccess.FieldAccessorTable<TestMessage, TestMessage.Builder> InternalFieldAccessors {
+      get { return global::Google.ProtocolBuffers.TestProtos.NoGenericService.UnitTestNoGenericServicesProtoFile.internal__static_google_protobuf_no_generic_services_test_TestMessage__FieldAccessorTable; }
+    }
+    
+    public const int AFieldNumber = 1;
+    private bool hasA;
+    private int a_ = 0;
+    public bool HasA {
+      get { return hasA; }
+    }
+    public int A {
+      get { return a_; }
+    }
+    
+    public override bool IsInitialized {
+      get {
+        if (!ExtensionsAreInitialized) return false;
+        return true;
+      }
+    }
+    
+    public override void WriteTo(pb::CodedOutputStream output) {
+      int size = SerializedSize;
+      pb::ExtendableMessage<TestMessage, TestMessage.Builder>.ExtensionWriter extensionWriter = CreateExtensionWriter(this);
+      if (HasA) {
+        output.WriteInt32(1, A);
+      }
+      extensionWriter.WriteUntil(536870912, output);
+      UnknownFields.WriteTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public override int SerializedSize {
+      get {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+        
+        size = 0;
+        if (HasA) {
+          size += pb::CodedOutputStream.ComputeInt32Size(1, A);
+        }
+        size += ExtensionsSerializedSize;
+        size += UnknownFields.SerializedSize;
+        memoizedSerializedSize = size;
+        return size;
+      }
+    }
+    
+    public static TestMessage ParseFrom(pb::ByteString data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static TestMessage ParseFrom(pb::ByteString data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static TestMessage ParseFrom(byte[] data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static TestMessage ParseFrom(byte[] data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static TestMessage ParseFrom(global::System.IO.Stream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static TestMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
+    }
+    public static TestMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
+    public static TestMessage ParseFrom(pb::CodedInputStream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static TestMessage 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(TestMessage prototype) {
+      return (Builder) new Builder().MergeFrom(prototype);
+    }
+    
+    public sealed partial class Builder : pb::ExtendableBuilder<TestMessage, Builder> {
+      protected override Builder ThisBuilder {
+        get { return this; }
+      }
+      public Builder() {}
+      
+      TestMessage result = new TestMessage();
+      
+      protected override TestMessage MessageBeingBuilt {
+        get { return result; }
+      }
+      
+      public override Builder Clear() {
+        result = new TestMessage();
+        return this;
+      }
+      
+      public override Builder Clone() {
+        return new Builder().MergeFrom(result);
+      }
+      
+      public override pbd::MessageDescriptor DescriptorForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.Descriptor; }
+      }
+      
+      public override TestMessage DefaultInstanceForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.DefaultInstance; }
+      }
+      
+      public override TestMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
+        TestMessage returnMe = result;
+        result = null;
+        return returnMe;
+      }
+      
+      public override Builder MergeFrom(pb::IMessage other) {
+        if (other is TestMessage) {
+          return MergeFrom((TestMessage) other);
+        } else {
+          base.MergeFrom(other);
+          return this;
+        }
+      }
+      
+      public override Builder MergeFrom(TestMessage other) {
+        if (other == global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.DefaultInstance) return this;
+        if (other.HasA) {
+          A = other.A;
+        }
+          this.MergeExtensionFields(other);
+        this.MergeUnknownFields(other.UnknownFields);
+        return this;
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input) {
+        return MergeFrom(input, pb::ExtensionRegistry.Empty);
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {
+        pb::UnknownFieldSet.Builder unknownFields = null;
+        while (true) {
+          uint tag = input.ReadTag();
+          switch (tag) {
+            case 0: {
+              if (unknownFields != null) {
+                this.UnknownFields = unknownFields.Build();
+              }
+              return this;
+            }
+            default: {
+              if (pb::WireFormat.IsEndGroupTag(tag)) {
+                if (unknownFields != null) {
+                  this.UnknownFields = unknownFields.Build();
+                }
+                return this;
+              }
+              if (unknownFields == null) {
+                unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
+              }
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              break;
+            }
+            case 8: {
+              A = input.ReadInt32();
+              break;
+            }
+          }
+        }
+      }
+      
+      
+      public bool HasA {
+        get { return result.HasA; }
+      }
+      public int A {
+        get { return result.A; }
+        set { SetA(value); }
+      }
+      public Builder SetA(int value) {
+        result.hasA = true;
+        result.a_ = value;
+        return this;
+      }
+      public Builder ClearA() {
+        result.hasA = false;
+        result.a_ = 0;
+        return this;
+      }
+    }
+    static TestMessage() {
+      object.ReferenceEquals(global::Google.ProtocolBuffers.TestProtos.NoGenericService.UnitTestNoGenericServicesProtoFile.Descriptor, null);
+    }
+  }
+  
+  #endregion
+  
+  #region Services
+  public abstract class TestService : pb::IService {
+    public abstract void Foo(
+        pb::IRpcController controller,
+        global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage request,
+        global::System.Action<global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage> done);
+    
+    public static pbd::ServiceDescriptor Descriptor {
+      get { return UnitTestNoGenericServicesProtoFile.Descriptor.Services[0]; }
+    }
+    public pbd::ServiceDescriptor DescriptorForType {
+      get { return Descriptor; }
+    }
+    
+    public void CallMethod(
+        pbd::MethodDescriptor method,
+        pb::IRpcController controller,
+        pb::IMessage request,
+        global::System.Action<pb::IMessage> done) {
+      if (method.Service != Descriptor) {
+        throw new global::System.ArgumentException(
+            "Service.CallMethod() given method descriptor for wrong service type.");
+      }
+      switch(method.Index) {
+        case 0:
+          this.Foo(controller, (global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage) request,
+              pb::RpcUtil.SpecializeCallback<global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage>(
+              done));
+          return;
+        default:
+          throw new global::System.InvalidOperationException("Can't get here.");
+      }
+    }
+    
+    public pb::IMessage GetRequestPrototype(pbd::MethodDescriptor method) {
+      if (method.Service != Descriptor) {
+        throw new global::System.ArgumentException(
+            "Service.GetRequestPrototype() given method descriptor for wrong service type.");
+      }
+      switch(method.Index) {
+        case 0:
+          return global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.DefaultInstance;
+        default:
+          throw new global::System.InvalidOperationException("Can't get here.");
+      }
+    }
+    
+    public pb::IMessage GetResponsePrototype(pbd::MethodDescriptor method) {
+      if (method.Service != Descriptor) {
+        throw new global::System.ArgumentException(
+            "Service.GetResponsePrototype() given method descriptor for wrong service type.");
+      }
+      switch(method.Index) {
+        case 0:
+          return global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.DefaultInstance;
+        default:
+          throw new global::System.InvalidOperationException("Can't get here.");
+      }
+    }
+    
+    public static Stub CreateStub(pb::IRpcChannel channel) {
+      return new Stub(channel);
+    }
+    
+    public class Stub : global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestService {
+      internal Stub(pb::IRpcChannel channel) {
+        this.channel = channel;
+      }
+      
+      private readonly pb::IRpcChannel channel;
+      
+      public pb::IRpcChannel Channel {
+        get { return channel; }
+      }
+      
+      public override void Foo(
+          pb::IRpcController controller,
+          global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage request,
+          global::System.Action<global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage> done) {
+        channel.CallMethod(Descriptor.Methods[0],
+            controller, request, global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.DefaultInstance,
+            pb::RpcUtil.GeneralizeCallback<global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage, global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.Builder>(done, global::Google.ProtocolBuffers.TestProtos.NoGenericService.TestMessage.DefaultInstance));
+      }
+    }
+  }
+  #endregion
+  
+}

src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs

@@ -1,4 +1,4 @@
-// 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

@@ -1,6 +1,34 @@
 
 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/AbstractBuilder.cs

@@ -42,93 +42,57 @@ namespace Google.ProtocolBuffers {
   /// <summary>
   /// Implementation of the non-generic IMessage interface as far as possible.
   /// </summary>
-  public abstract class AbstractBuilder<TMessage, TBuilder> : IBuilder<TMessage, TBuilder> 
+  public abstract class AbstractBuilder<TMessage, TBuilder> : AbstractBuilderLite<TMessage, TBuilder>, IBuilder<TMessage, TBuilder> 
       where TMessage : AbstractMessage<TMessage, TBuilder>
       where TBuilder : AbstractBuilder<TMessage, TBuilder> {
 
-    protected abstract TBuilder ThisBuilder { get; }
-    
     #region Unimplemented members of IBuilder
     public abstract UnknownFieldSet UnknownFields { get; set; }
-    public abstract TBuilder MergeFrom(TMessage other);
-    public abstract bool IsInitialized { get; }
     public abstract IDictionary<FieldDescriptor, object> AllFields { get; }
     public abstract object this[FieldDescriptor field] { get; set; }
     public abstract MessageDescriptor DescriptorForType { get; }
     public abstract int GetRepeatedFieldCount(FieldDescriptor field);
     public abstract object this[FieldDescriptor field, int index] { get; set; }
     public abstract bool HasField(FieldDescriptor field);
-    public abstract TMessage Build();
-    public abstract TMessage BuildPartial();
-    public abstract TBuilder Clone();
-    public abstract TMessage DefaultInstanceForType { get; }
     public abstract IBuilder CreateBuilderForField(FieldDescriptor field);
     public abstract TBuilder ClearField(FieldDescriptor field);
     public abstract TBuilder AddRepeatedField(FieldDescriptor field, object value);
     #endregion
 
-    #region Implementation of methods which don't require type parameter information
-    public IMessage WeakBuild() {
-      return Build();
-    }
-
-    public IBuilder WeakAddRepeatedField(FieldDescriptor field, object value) {
-      return AddRepeatedField(field, value);
-    }
-
-    public IBuilder WeakClear() {
-      return Clear();
-    }
-
-    public IBuilder WeakMergeFrom(IMessage message) {
-      return MergeFrom(message);
-    }
-
-    public IBuilder WeakMergeFrom(CodedInputStream input) {
-      return MergeFrom(input);
-    }
-
-    public IBuilder WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry) {
-      return MergeFrom(input, registry);
-    }
-
-    public IBuilder WeakMergeFrom(ByteString data) {
-      return MergeFrom(data);
-    }
-
-    public IBuilder WeakMergeFrom(ByteString data, ExtensionRegistry registry) {
-      return MergeFrom(data, registry);
-    }
-
-    public IMessage WeakBuildPartial() {
-      return BuildPartial();
-    }
-
-    public IBuilder WeakClone() {
-      return Clone();
-    }
-
-    public IMessage WeakDefaultInstanceForType {
-      get { return DefaultInstanceForType; } 
-    }
-
-    public IBuilder WeakClearField(FieldDescriptor field) {
-      return ClearField(field);
-    }
-    #endregion
-
     public TBuilder SetUnknownFields(UnknownFieldSet fields) {
       UnknownFields = fields;
       return ThisBuilder;
     }
 
-    public virtual TBuilder Clear() {
+    public override TBuilder Clear() {
       foreach(FieldDescriptor field in AllFields.Keys) {
         ClearField(field);
       }
       return ThisBuilder;
     }
 
+    public sealed override TBuilder MergeFrom(IMessageLite other) {
+      if (other is IMessage) {
+        return MergeFrom((IMessage) other);
+      }
+      throw new ArgumentException("MergeFrom(Message) can only merge messages of the same type.");
+    }
+
+    /// <summary>
+    /// Merge the specified other message into the message being
+    /// built. Merging occurs as follows. For each field:
+    /// For singular primitive fields, if the field is set in <paramref name="other"/>,
+    /// then <paramref name="other"/>'s value overwrites the value in this message.
+    /// For singular message fields, if the field is set in <paramref name="other"/>,
+    /// it is merged into the corresponding sub-message of this message using the same
+    /// merging rules.
+    /// For repeated fields, the elements in <paramref name="other"/> are concatenated
+    /// with the elements in this message.
+    /// </summary>
+    /// <param name="other"></param>
+    /// <returns></returns>
+    public abstract TBuilder MergeFrom(TMessage other);
+
     public virtual TBuilder MergeFrom(IMessage other) {
       if (other.DescriptorForType != DescriptorForType) {
         throw new ArgumentException("MergeFrom(IMessage) can only merge messages of the same type.");
@@ -151,13 +115,13 @@ namespace Google.ProtocolBuffers {
           }
         } else if (field.MappedType == MappedType.Message) {
           // Merge singular messages
-          IMessage existingValue = (IMessage) this[field];
+          IMessageLite existingValue = (IMessageLite)this[field];
           if (existingValue == existingValue.WeakDefaultInstanceForType) {
             this[field] = entry.Value;
           } else {
             this[field] = existingValue.WeakCreateBuilderForType()
                                        .WeakMergeFrom(existingValue)
-                                       .WeakMergeFrom((IMessage) entry.Value)
+                                       .WeakMergeFrom((IMessageLite)entry.Value)
                                        .WeakBuild();
           }
         } else {
@@ -165,14 +129,14 @@ namespace Google.ProtocolBuffers {
           this[field] = entry.Value;
         }
       }
-      return ThisBuilder;
-    }
 
-    public virtual TBuilder MergeFrom(CodedInputStream input) {
-      return MergeFrom(input, ExtensionRegistry.Empty);
+      //Fix for unknown fields not merging, see java's AbstractMessage.Builder<T> line 236
+      MergeUnknownFields(other.UnknownFields);
+
+      return ThisBuilder;
     }
 
-    public virtual TBuilder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry) {
+    public override TBuilder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry) {
       UnknownFieldSet.Builder unknownFields = UnknownFieldSet.CreateBuilder(UnknownFields);
       unknownFields.MergeFrom(input, extensionRegistry, this);
       UnknownFields = unknownFields.Build();
@@ -186,131 +150,65 @@ namespace Google.ProtocolBuffers {
       return ThisBuilder;
     }
 
-    public virtual TBuilder MergeFrom(ByteString data) {
-      CodedInputStream input = data.CreateCodedInput();
-      MergeFrom(input);
-      input.CheckLastTagWas(0);
+    public virtual IBuilder SetField(FieldDescriptor field, object value) {
+      this[field] = value;
       return ThisBuilder;
     }
 
-    public virtual TBuilder MergeFrom(ByteString data, ExtensionRegistry extensionRegistry) {
-      CodedInputStream input = data.CreateCodedInput();
-      MergeFrom(input, extensionRegistry);
-      input.CheckLastTagWas(0);
+    public virtual IBuilder SetRepeatedField(FieldDescriptor field, int index, object value) {
+      this[field, index] = value;
       return ThisBuilder;
-    }
+	  }
 
-    public virtual TBuilder MergeFrom(byte[] data) {
-      CodedInputStream input = CodedInputStream.CreateInstance(data);
-      MergeFrom(input);
-      input.CheckLastTagWas(0);
-      return ThisBuilder;
-    }
+    #region Explicit Implementations
 
-    public virtual TBuilder MergeFrom(byte[] data, ExtensionRegistry extensionRegistry) {
-      CodedInputStream input = CodedInputStream.CreateInstance(data);
-      MergeFrom(input, extensionRegistry);
-      input.CheckLastTagWas(0);
-      return ThisBuilder;
+    IMessage IBuilder.WeakBuild() {
+      return Build();
     }
 
-    public virtual TBuilder MergeFrom(Stream input) {
-      CodedInputStream codedInput = CodedInputStream.CreateInstance(input);
-      MergeFrom(codedInput);
-      codedInput.CheckLastTagWas(0);
-      return ThisBuilder;
+    IBuilder IBuilder.WeakAddRepeatedField(FieldDescriptor field, object value) {
+      return AddRepeatedField(field, value);
     }
 
-    public virtual TBuilder MergeFrom(Stream input, ExtensionRegistry extensionRegistry) {
-      CodedInputStream codedInput = CodedInputStream.CreateInstance(input);
-      MergeFrom(codedInput, extensionRegistry);
-      codedInput.CheckLastTagWas(0);
-      return ThisBuilder;
+    IBuilder IBuilder.WeakClear() {
+      return Clear();
     }
 
-    public TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry) {
-      int size = (int) CodedInputStream.ReadRawVarint32(input);
-      Stream limitedStream = new LimitedInputStream(input, size);
-      return MergeFrom(limitedStream, extensionRegistry);
+    IBuilder IBuilder.WeakMergeFrom(IMessage message) {
+      return MergeFrom(message);
     }
 
-    public TBuilder MergeDelimitedFrom(Stream input) {
-      return MergeDelimitedFrom(input, ExtensionRegistry.Empty);
+    IBuilder IBuilder.WeakMergeFrom(CodedInputStream input) {
+      return MergeFrom(input);
     }
 
-    public virtual IBuilder SetField(FieldDescriptor field, object value) {
-      this[field] = value;
-      return ThisBuilder;
+    IBuilder IBuilder.WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry) {
+      return MergeFrom(input, registry);
     }
 
-    public virtual IBuilder SetRepeatedField(FieldDescriptor field, int index, object value) {
-      this[field, index] = value;
-      return ThisBuilder;
+    IBuilder IBuilder.WeakMergeFrom(ByteString data) {
+      return MergeFrom(data);
     }
 
-    /// <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 NotImplementedException(); }
-      }
-
-      public override long Position {
-        get {
-          throw new NotImplementedException();
-        }
-        set {
-          throw new NotImplementedException();
-        }
-      }
+    IBuilder IBuilder.WeakMergeFrom(ByteString data, ExtensionRegistry registry) {
+      return MergeFrom(data, registry);
+    }
 
-      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;
-      }
+    IMessage IBuilder.WeakBuildPartial() {
+      return BuildPartial();
+    }
 
-      public override long Seek(long offset, SeekOrigin origin) {
-        throw new NotImplementedException();
-      }
+    IBuilder IBuilder.WeakClone() {
+      return Clone();
+    }
 
-      public override void SetLength(long value) {
-        throw new NotImplementedException();
-      }
+    IMessage IBuilder.WeakDefaultInstanceForType {
+      get { return DefaultInstanceForType; }
+    }
 
-      public override void Write(byte[] buffer, int offset, int count) {
-        throw new NotImplementedException();
-      }
+    IBuilder IBuilder.WeakClearField(FieldDescriptor field) {
+      return ClearField(field);
     }
+    #endregion
   }
 }

src/ProtocolBuffers/AbstractBuilderLite.cs

@@ -0,0 +1,232 @@
+#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

@@ -0,0 +1,133 @@
+#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/CodedOutputStream.cs

@@ -206,19 +206,20 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Writes a group field value, including tag, to the stream.
     /// </summary>
-    public void WriteGroup(int fieldNumber, IMessage value) {
+    public void WriteGroup(int fieldNumber, IMessageLite value) {
       WriteTag(fieldNumber, WireFormat.WireType.StartGroup);
       value.WriteTo(this);
       WriteTag(fieldNumber, WireFormat.WireType.EndGroup);
     }
 
-    public void WriteUnknownGroup(int fieldNumber, UnknownFieldSet value) {
+    [Obsolete]
+    public void WriteUnknownGroup(int fieldNumber, IMessageLite value) {
       WriteTag(fieldNumber, WireFormat.WireType.StartGroup);
       value.WriteTo(this);
       WriteTag(fieldNumber, WireFormat.WireType.EndGroup);
     }
 
-    public void WriteMessage(int fieldNumber, IMessage value) {
+    public void WriteMessage(int fieldNumber, IMessageLite value) {
       WriteTag(fieldNumber, WireFormat.WireType.LengthDelimited);
       WriteRawVarint32((uint)value.SerializedSize);
       value.WriteTo(this);
@@ -263,7 +264,7 @@ namespace Google.ProtocolBuffers {
       WriteRawVarint64(EncodeZigZag64(value));
     }
 
-    public void WriteMessageSetExtension(int fieldNumber, IMessage value) {
+    public void WriteMessageSetExtension(int fieldNumber, IMessageLite value) {
       WriteTag(WireFormat.MessageSetField.Item, WireFormat.WireType.StartGroup);
       WriteUInt32(WireFormat.MessageSetField.TypeID, (uint)fieldNumber);
       WriteMessage(WireFormat.MessageSetField.Message, value);
@@ -288,15 +289,15 @@ namespace Google.ProtocolBuffers {
         case FieldType.Fixed32: WriteFixed32(fieldNumber, (uint)value); break;
         case FieldType.Bool: WriteBool(fieldNumber, (bool)value); break;
         case FieldType.String: WriteString(fieldNumber, (string)value); break;
-        case FieldType.Group: WriteGroup(fieldNumber, (IMessage)value); break;
-        case FieldType.Message: WriteMessage(fieldNumber, (IMessage)value); break;
+        case FieldType.Group: WriteGroup(fieldNumber, (IMessageLite)value); break;
+        case FieldType.Message: WriteMessage(fieldNumber, (IMessageLite)value); break;
         case FieldType.Bytes: WriteBytes(fieldNumber, (ByteString)value); break;
         case FieldType.UInt32: WriteUInt32(fieldNumber, (uint)value); break;
         case FieldType.SFixed32: WriteSFixed32(fieldNumber, (int)value); break;
         case FieldType.SFixed64: WriteSFixed64(fieldNumber, (long)value); break;
         case FieldType.SInt32: WriteSInt32(fieldNumber, (int)value); break;
         case FieldType.SInt64: WriteSInt64(fieldNumber, (long)value); break;
-        case FieldType.Enum: WriteEnum(fieldNumber, ((EnumValueDescriptor)value).Number);
+        case FieldType.Enum: WriteEnum(fieldNumber, ((IEnumLite)value).Number);
           break;
       }
     }
@@ -312,15 +313,15 @@ namespace Google.ProtocolBuffers {
         case FieldType.Fixed32: WriteFixed32NoTag((uint)value); break;
         case FieldType.Bool: WriteBoolNoTag((bool)value); break;
         case FieldType.String: WriteStringNoTag((string)value); break;
-        case FieldType.Group: WriteGroupNoTag((IMessage)value); break;
-        case FieldType.Message: WriteMessageNoTag((IMessage)value); break;
+        case FieldType.Group: WriteGroupNoTag((IMessageLite)value); break;
+        case FieldType.Message: WriteMessageNoTag((IMessageLite)value); break;
         case FieldType.Bytes: WriteBytesNoTag((ByteString)value); break;
         case FieldType.UInt32: WriteUInt32NoTag((uint)value); break;
         case FieldType.SFixed32: WriteSFixed32NoTag((int)value); break;
         case FieldType.SFixed64: WriteSFixed64NoTag((long)value); break;
         case FieldType.SInt32: WriteSInt32NoTag((int)value); break;
         case FieldType.SInt64: WriteSInt64NoTag((long)value); break;
-        case FieldType.Enum: WriteEnumNoTag(((EnumValueDescriptor)value).Number);
+        case FieldType.Enum: WriteEnumNoTag(((IEnumLite)value).Number);
           break;
       }
     }
@@ -420,11 +421,11 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Writes a group field value, without a tag, to the stream.
     /// </summary>
-    public void WriteGroupNoTag(IMessage value) {
+    public void WriteGroupNoTag(IMessageLite value) {
       value.WriteTo(this);
     }
 
-    public void WriteMessageNoTag(IMessage value) {
+    public void WriteMessageNoTag(IMessageLite value) {
       WriteRawVarint32((uint)value.SerializedSize);
       value.WriteTo(this);
     }
@@ -685,7 +686,7 @@ namespace Google.ProtocolBuffers {
     /// Compute the number of bytes that would be needed to encode a
     /// group field, including the tag.
     /// </summary>
-    public static int ComputeGroupSize(int fieldNumber, IMessage value) {
+    public static int ComputeGroupSize(int fieldNumber, IMessageLite value) {
       return ComputeTagSize(fieldNumber) * 2 + value.SerializedSize;
     }
 
@@ -693,8 +694,9 @@ namespace Google.ProtocolBuffers {
     /// Compute the number of bytes that would be needed to encode a
     /// group field represented by an UnknownFieldSet, including the tag.
     /// </summary>
+    [Obsolete]
     public static int ComputeUnknownGroupSize(int fieldNumber,
-                                              UnknownFieldSet value) {
+                                              IMessageLite value) {
       return ComputeTagSize(fieldNumber) * 2 + value.SerializedSize;
     }
 
@@ -702,7 +704,7 @@ namespace Google.ProtocolBuffers {
     /// Compute the number of bytes that would be needed to encode an
     /// embedded message field, including the tag.
     /// </summary>
-    public static int ComputeMessageSize(int fieldNumber, IMessage value) {
+    public static int ComputeMessageSize(int fieldNumber, IMessageLite value) {
       int size = value.SerializedSize;
       return ComputeTagSize(fieldNumber) + ComputeRawVarint32Size((uint)size) + size;
     }
@@ -853,7 +855,7 @@ namespace Google.ProtocolBuffers {
     /// Compute the number of bytes that would be needed to encode a
     /// group field, including the tag.
     /// </summary>
-    public static int ComputeGroupSizeNoTag(IMessage value) {
+    public static int ComputeGroupSizeNoTag(IMessageLite value) {
       return value.SerializedSize;
     }
 
@@ -861,7 +863,8 @@ namespace Google.ProtocolBuffers {
     /// Compute the number of bytes that would be needed to encode a
     /// group field represented by an UnknownFieldSet, including the tag.
     /// </summary>
-    public static int ComputeUnknownGroupSizeNoTag(UnknownFieldSet value) {
+    [Obsolete]
+    public static int ComputeUnknownGroupSizeNoTag(IMessageLite value) {
       return value.SerializedSize;
     }
 
@@ -869,7 +872,7 @@ namespace Google.ProtocolBuffers {
     /// Compute the number of bytes that would be needed to encode an
     /// embedded message field, including the tag.
     /// </summary>
-    public static int ComputeMessageSizeNoTag(IMessage value) {
+    public static int ComputeMessageSizeNoTag(IMessageLite value) {
       int size = value.SerializedSize;
       return ComputeRawVarint32Size((uint)size) + size;
     }
@@ -943,7 +946,7 @@ namespace Google.ProtocolBuffers {
     /// MessageSet extension to the stream. For historical reasons,
     /// the wire format differs from normal fields.
     /// </summary>
-    public static int ComputeMessageSetExtensionSize(int fieldNumber, IMessage value) {
+    public static int ComputeMessageSetExtensionSize(int fieldNumber, IMessageLite value) {
       return ComputeTagSize(WireFormat.MessageSetField.Item) * 2 +
              ComputeUInt32Size(WireFormat.MessageSetField.TypeID, (uint) fieldNumber) +
              ComputeMessageSize(WireFormat.MessageSetField.Message, value);
@@ -1004,15 +1007,15 @@ namespace Google.ProtocolBuffers {
         case FieldType.Fixed32: return ComputeFixed32Size(fieldNumber, (uint)value);
         case FieldType.Bool: return ComputeBoolSize(fieldNumber, (bool)value);
         case FieldType.String: return ComputeStringSize(fieldNumber, (string)value);
-        case FieldType.Group: return ComputeGroupSize(fieldNumber, (IMessage)value);
-        case FieldType.Message: return ComputeMessageSize(fieldNumber, (IMessage)value);
+        case FieldType.Group: return ComputeGroupSize(fieldNumber, (IMessageLite)value);
+        case FieldType.Message: return ComputeMessageSize(fieldNumber, (IMessageLite)value);
         case FieldType.Bytes: return ComputeBytesSize(fieldNumber, (ByteString)value);
         case FieldType.UInt32: return ComputeUInt32Size(fieldNumber, (uint)value);
         case FieldType.SFixed32: return ComputeSFixed32Size(fieldNumber, (int)value);
         case FieldType.SFixed64: return ComputeSFixed64Size(fieldNumber, (long)value);
         case FieldType.SInt32: return ComputeSInt32Size(fieldNumber, (int)value);
         case FieldType.SInt64: return ComputeSInt64Size(fieldNumber, (long)value);
-        case FieldType.Enum: return ComputeEnumSize(fieldNumber, ((EnumValueDescriptor)value).Number);
+        case FieldType.Enum: return ComputeEnumSize(fieldNumber, ((IEnumLite)value).Number);
         default:
           throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);
       }
@@ -1033,15 +1036,15 @@ namespace Google.ProtocolBuffers {
         case FieldType.Fixed32: return ComputeFixed32SizeNoTag((uint)value);
         case FieldType.Bool: return ComputeBoolSizeNoTag((bool)value);
         case FieldType.String: return ComputeStringSizeNoTag((string)value);
-        case FieldType.Group: return ComputeGroupSizeNoTag((IMessage)value);
-        case FieldType.Message: return ComputeMessageSizeNoTag((IMessage)value);
+        case FieldType.Group: return ComputeGroupSizeNoTag((IMessageLite)value);
+        case FieldType.Message: return ComputeMessageSizeNoTag((IMessageLite)value);
         case FieldType.Bytes: return ComputeBytesSizeNoTag((ByteString)value);
         case FieldType.UInt32: return ComputeUInt32SizeNoTag((uint)value);
         case FieldType.SFixed32: return ComputeSFixed32SizeNoTag((int)value);
         case FieldType.SFixed64: return ComputeSFixed64SizeNoTag((long)value);
         case FieldType.SInt32: return ComputeSInt32SizeNoTag((int)value);
         case FieldType.SInt64: return ComputeSInt64SizeNoTag((long)value);
-        case FieldType.Enum: return ComputeEnumSizeNoTag(((EnumValueDescriptor)value).Number);
+        case FieldType.Enum: return ComputeEnumSizeNoTag(((IEnumLite)value).Number);
         default:
           throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);
       }

src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs

@@ -1,4 +1,4 @@
-// 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/DescriptorProtos/DescriptorProtoFile.cs

@@ -1,4 +1,4 @@
-// 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;
@@ -104,38 +104,42 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
           "Lmdvb2dsZS5wcm90b2J1Zi5TZXJ2aWNlT3B0aW9ucyJ/ChVNZXRob2REZXNj" + 
           "cmlwdG9yUHJvdG8SDAoEbmFtZRgBIAEoCRISCgppbnB1dF90eXBlGAIgASgJ" + 
           "EhMKC291dHB1dF90eXBlGAMgASgJEi8KB29wdGlvbnMYBCABKAsyHi5nb29n" + 
-          "bGUucHJvdG9idWYuTWV0aG9kT3B0aW9ucyKnAgoLRmlsZU9wdGlvbnMSFAoM" + 
+          "bGUucHJvdG9idWYuTWV0aG9kT3B0aW9ucyKkAwoLRmlsZU9wdGlvbnMSFAoM" + 
           "amF2YV9wYWNrYWdlGAEgASgJEhwKFGphdmFfb3V0ZXJfY2xhc3NuYW1lGAgg" + 
           "ASgJEiIKE2phdmFfbXVsdGlwbGVfZmlsZXMYCiABKAg6BWZhbHNlEkYKDG9w" + 
           "dGltaXplX2ZvchgJIAEoDjIpLmdvb2dsZS5wcm90b2J1Zi5GaWxlT3B0aW9u" + 
-          "cy5PcHRpbWl6ZU1vZGU6BVNQRUVEEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9u" + 
-          "GOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9u" + 
-          "IigKDE9wdGltaXplTW9kZRIJCgVTUEVFRBABEg0KCUNPREVfU0laRRACKgkI" + 
-          "6AcQgICAgAIiiAEKDk1lc3NhZ2VPcHRpb25zEiYKF21lc3NhZ2Vfc2V0X3dp" + 
-          "cmVfZm9ybWF0GAEgASgIOgVmYWxzZRJDChR1bmludGVycHJldGVkX29wdGlv" + 
-          "bhjnByADKAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlv" + 
-          "bioJCOgHEICAgIACIoACCgxGaWVsZE9wdGlvbnMSMgoFY3R5cGUYASABKA4y" + 
-          "Iy5nb29nbGUucHJvdG9idWYuRmllbGRPcHRpb25zLkNUeXBlEg4KBnBhY2tl" + 
-          "ZBgCIAEoCBIZCgpkZXByZWNhdGVkGAMgASgIOgVmYWxzZRIcChRleHBlcmlt" + 
-          "ZW50YWxfbWFwX2tleRgJIAEoCRJDChR1bmludGVycHJldGVkX29wdGlvbhjn" + 
-          "ByADKAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlvbiIj" + 
-          "CgVDVHlwZRIICgRDT1JEEAESEAoMU1RSSU5HX1BJRUNFEAIqCQjoBxCAgICA" + 
-          "AiJdCgtFbnVtT3B0aW9ucxJDChR1bmludGVycHJldGVkX29wdGlvbhjnByAD" + 
-          "KAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlvbioJCOgH" + 
-          "EICAgIACImIKEEVudW1WYWx1ZU9wdGlvbnMSQwoUdW5pbnRlcnByZXRlZF9v" + 
-          "cHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0ZWRP" + 
-          "cHRpb24qCQjoBxCAgICAAiJgCg5TZXJ2aWNlT3B0aW9ucxJDChR1bmludGVy" + 
-          "cHJldGVkX29wdGlvbhjnByADKAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRl" + 
-          "cnByZXRlZE9wdGlvbioJCOgHEICAgIACIl8KDU1ldGhvZE9wdGlvbnMSQwoU" + 
-          "dW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVm" + 
-          "LlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAiKFAgoTVW5pbnRlcnBy" + 
-          "ZXRlZE9wdGlvbhI7CgRuYW1lGAIgAygLMi0uZ29vZ2xlLnByb3RvYnVmLlVu" + 
-          "aW50ZXJwcmV0ZWRPcHRpb24uTmFtZVBhcnQSGAoQaWRlbnRpZmllcl92YWx1" + 
-          "ZRgDIAEoCRIaChJwb3NpdGl2ZV9pbnRfdmFsdWUYBCABKAQSGgoSbmVnYXRp" + 
-          "dmVfaW50X3ZhbHVlGAUgASgDEhQKDGRvdWJsZV92YWx1ZRgGIAEoARIUCgxz" + 
-          "dHJpbmdfdmFsdWUYByABKAwaMwoITmFtZVBhcnQSEQoJbmFtZV9wYXJ0GAEg" + 
-          "AigJEhQKDGlzX2V4dGVuc2lvbhgCIAIoCEIpChNjb20uZ29vZ2xlLnByb3Rv" + 
-          "YnVmQhBEZXNjcmlwdG9yUHJvdG9zSAE=");
+          "cy5PcHRpbWl6ZU1vZGU6BVNQRUVEEiEKE2NjX2dlbmVyaWNfc2VydmljZXMY" + 
+          "ECABKAg6BHRydWUSIwoVamF2YV9nZW5lcmljX3NlcnZpY2VzGBEgASgIOgR0" + 
+          "cnVlEiEKE3B5X2dlbmVyaWNfc2VydmljZXMYEiABKAg6BHRydWUSQwoUdW5p" + 
+          "bnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVu" + 
+          "aW50ZXJwcmV0ZWRPcHRpb24iOgoMT3B0aW1pemVNb2RlEgkKBVNQRUVEEAES" + 
+          "DQoJQ09ERV9TSVpFEAISEAoMTElURV9SVU5USU1FEAMqCQjoBxCAgICAAiK4" + 
+          "AQoOTWVzc2FnZU9wdGlvbnMSJgoXbWVzc2FnZV9zZXRfd2lyZV9mb3JtYXQY" + 
+          "ASABKAg6BWZhbHNlEi4KH25vX3N0YW5kYXJkX2Rlc2NyaXB0b3JfYWNjZXNz" + 
+          "b3IYAiABKAg6BWZhbHNlEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMo" + 
+          "CzIkLmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uKgkI6AcQ" + 
+          "gICAgAIilAIKDEZpZWxkT3B0aW9ucxI6CgVjdHlwZRgBIAEoDjIjLmdvb2ds" + 
+          "ZS5wcm90b2J1Zi5GaWVsZE9wdGlvbnMuQ1R5cGU6BlNUUklORxIOCgZwYWNr" + 
+          "ZWQYAiABKAgSGQoKZGVwcmVjYXRlZBgDIAEoCDoFZmFsc2USHAoUZXhwZXJp" + 
+          "bWVudGFsX21hcF9rZXkYCSABKAkSQwoUdW5pbnRlcnByZXRlZF9vcHRpb24Y" + 
+          "5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24i" + 
+          "LwoFQ1R5cGUSCgoGU1RSSU5HEAASCAoEQ09SRBABEhAKDFNUUklOR19QSUVD" + 
+          "RRACKgkI6AcQgICAgAIiXQoLRW51bU9wdGlvbnMSQwoUdW5pbnRlcnByZXRl" + 
+          "ZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0" + 
+          "ZWRPcHRpb24qCQjoBxCAgICAAiJiChBFbnVtVmFsdWVPcHRpb25zEkMKFHVu" + 
+          "aW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5V" + 
+          "bmludGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIiYAoOU2VydmljZU9wdGlv" + 
+          "bnMSQwoUdW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnBy" + 
+          "b3RvYnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAiJfCg1NZXRo" + 
+          "b2RPcHRpb25zEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdv" + 
+          "b2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIi" + 
+          "hQIKE1VuaW50ZXJwcmV0ZWRPcHRpb24SOwoEbmFtZRgCIAMoCzItLmdvb2ds" + 
+          "ZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uLk5hbWVQYXJ0EhgKEGlk" + 
+          "ZW50aWZpZXJfdmFsdWUYAyABKAkSGgoScG9zaXRpdmVfaW50X3ZhbHVlGAQg" + 
+          "ASgEEhoKEm5lZ2F0aXZlX2ludF92YWx1ZRgFIAEoAxIUCgxkb3VibGVfdmFs" + 
+          "dWUYBiABKAESFAoMc3RyaW5nX3ZhbHVlGAcgASgMGjMKCE5hbWVQYXJ0EhEK" + 
+          "CW5hbWVfcGFydBgBIAIoCRIUCgxpc19leHRlbnNpb24YAiACKAhCKQoTY29t" + 
+          "Lmdvb2dsZS5wcm90b2J1ZkIQRGVzY3JpcHRvclByb3Rvc0gB");
       pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {
         descriptor = root;
         internal__static_google_protobuf_FileDescriptorSet__Descriptor = Descriptor.MessageTypes[0];
@@ -177,11 +181,11 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         internal__static_google_protobuf_FileOptions__Descriptor = Descriptor.MessageTypes[8];
         internal__static_google_protobuf_FileOptions__FieldAccessorTable = 
             new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.DescriptorProtos.FileOptions, global::Google.ProtocolBuffers.DescriptorProtos.FileOptions.Builder>(internal__static_google_protobuf_FileOptions__Descriptor,
-                new string[] { "JavaPackage", "JavaOuterClassname", "JavaMultipleFiles", "OptimizeFor", "UninterpretedOption", });
+                new string[] { "JavaPackage", "JavaOuterClassname", "JavaMultipleFiles", "OptimizeFor", "CcGenericServices", "JavaGenericServices", "PyGenericServices", "UninterpretedOption", });
         internal__static_google_protobuf_MessageOptions__Descriptor = Descriptor.MessageTypes[9];
         internal__static_google_protobuf_MessageOptions__FieldAccessorTable = 
             new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.DescriptorProtos.MessageOptions, global::Google.ProtocolBuffers.DescriptorProtos.MessageOptions.Builder>(internal__static_google_protobuf_MessageOptions__Descriptor,
-                new string[] { "MessageSetWireFormat", "UninterpretedOption", });
+                new string[] { "MessageSetWireFormat", "NoStandardDescriptorAccessor", "UninterpretedOption", });
         internal__static_google_protobuf_FieldOptions__Descriptor = Descriptor.MessageTypes[10];
         internal__static_google_protobuf_FieldOptions__FieldAccessorTable = 
             new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions, global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Builder>(internal__static_google_protobuf_FieldOptions__Descriptor,
@@ -4013,6 +4017,7 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       public enum OptimizeMode {
         SPEED = 1,
         CODE_SIZE = 2,
+        LITE_RUNTIME = 3,
       }
       
     }
@@ -4058,6 +4063,36 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       get { return optimizeFor_; }
     }
     
+    public const int CcGenericServicesFieldNumber = 16;
+    private bool hasCcGenericServices;
+    private bool ccGenericServices_ = true;
+    public bool HasCcGenericServices {
+      get { return hasCcGenericServices; }
+    }
+    public bool CcGenericServices {
+      get { return ccGenericServices_; }
+    }
+    
+    public const int JavaGenericServicesFieldNumber = 17;
+    private bool hasJavaGenericServices;
+    private bool javaGenericServices_ = true;
+    public bool HasJavaGenericServices {
+      get { return hasJavaGenericServices; }
+    }
+    public bool JavaGenericServices {
+      get { return javaGenericServices_; }
+    }
+    
+    public const int PyGenericServicesFieldNumber = 18;
+    private bool hasPyGenericServices;
+    private bool pyGenericServices_ = true;
+    public bool HasPyGenericServices {
+      get { return hasPyGenericServices; }
+    }
+    public bool PyGenericServices {
+      get { return pyGenericServices_; }
+    }
+    
     public const int UninterpretedOptionFieldNumber = 999;
     private pbc::PopsicleList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption> uninterpretedOption_ = new pbc::PopsicleList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption>();
     public scg::IList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption> UninterpretedOptionList {
@@ -4095,6 +4130,15 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       if (HasJavaMultipleFiles) {
         output.WriteBool(10, JavaMultipleFiles);
       }
+      if (HasCcGenericServices) {
+        output.WriteBool(16, CcGenericServices);
+      }
+      if (HasJavaGenericServices) {
+        output.WriteBool(17, JavaGenericServices);
+      }
+      if (HasPyGenericServices) {
+        output.WriteBool(18, PyGenericServices);
+      }
       foreach (global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption element in UninterpretedOptionList) {
         output.WriteMessage(999, element);
       }
@@ -4121,6 +4165,15 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         if (HasOptimizeFor) {
           size += pb::CodedOutputStream.ComputeEnumSize(9, (int) OptimizeFor);
         }
+        if (HasCcGenericServices) {
+          size += pb::CodedOutputStream.ComputeBoolSize(16, CcGenericServices);
+        }
+        if (HasJavaGenericServices) {
+          size += pb::CodedOutputStream.ComputeBoolSize(17, JavaGenericServices);
+        }
+        if (HasPyGenericServices) {
+          size += pb::CodedOutputStream.ComputeBoolSize(18, PyGenericServices);
+        }
         foreach (global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption element in UninterpretedOptionList) {
           size += pb::CodedOutputStream.ComputeMessageSize(999, element);
         }
@@ -4230,6 +4283,15 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         if (other.HasOptimizeFor) {
           OptimizeFor = other.OptimizeFor;
         }
+        if (other.HasCcGenericServices) {
+          CcGenericServices = other.CcGenericServices;
+        }
+        if (other.HasJavaGenericServices) {
+          JavaGenericServices = other.JavaGenericServices;
+        }
+        if (other.HasPyGenericServices) {
+          PyGenericServices = other.PyGenericServices;
+        }
         if (other.uninterpretedOption_.Count != 0) {
           base.AddRange(other.uninterpretedOption_, result.uninterpretedOption_);
         }
@@ -4290,6 +4352,18 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
               JavaMultipleFiles = input.ReadBool();
               break;
             }
+            case 128: {
+              CcGenericServices = input.ReadBool();
+              break;
+            }
+            case 136: {
+              JavaGenericServices = input.ReadBool();
+              break;
+            }
+            case 144: {
+              PyGenericServices = input.ReadBool();
+              break;
+            }
             case 7994: {
               global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
               input.ReadMessage(subBuilder, extensionRegistry);
@@ -4375,6 +4449,60 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         return this;
       }
       
+      public bool HasCcGenericServices {
+        get { return result.HasCcGenericServices; }
+      }
+      public bool CcGenericServices {
+        get { return result.CcGenericServices; }
+        set { SetCcGenericServices(value); }
+      }
+      public Builder SetCcGenericServices(bool value) {
+        result.hasCcGenericServices = true;
+        result.ccGenericServices_ = value;
+        return this;
+      }
+      public Builder ClearCcGenericServices() {
+        result.hasCcGenericServices = false;
+        result.ccGenericServices_ = true;
+        return this;
+      }
+      
+      public bool HasJavaGenericServices {
+        get { return result.HasJavaGenericServices; }
+      }
+      public bool JavaGenericServices {
+        get { return result.JavaGenericServices; }
+        set { SetJavaGenericServices(value); }
+      }
+      public Builder SetJavaGenericServices(bool value) {
+        result.hasJavaGenericServices = true;
+        result.javaGenericServices_ = value;
+        return this;
+      }
+      public Builder ClearJavaGenericServices() {
+        result.hasJavaGenericServices = false;
+        result.javaGenericServices_ = true;
+        return this;
+      }
+      
+      public bool HasPyGenericServices {
+        get { return result.HasPyGenericServices; }
+      }
+      public bool PyGenericServices {
+        get { return result.PyGenericServices; }
+        set { SetPyGenericServices(value); }
+      }
+      public Builder SetPyGenericServices(bool value) {
+        result.hasPyGenericServices = true;
+        result.pyGenericServices_ = value;
+        return this;
+      }
+      public Builder ClearPyGenericServices() {
+        result.hasPyGenericServices = false;
+        result.pyGenericServices_ = true;
+        return this;
+      }
+      
       public pbc::IPopsicleList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption> UninterpretedOptionList {
         get { return result.uninterpretedOption_; }
       }
@@ -4450,6 +4578,16 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       get { return messageSetWireFormat_; }
     }
     
+    public const int NoStandardDescriptorAccessorFieldNumber = 2;
+    private bool hasNoStandardDescriptorAccessor;
+    private bool noStandardDescriptorAccessor_ = false;
+    public bool HasNoStandardDescriptorAccessor {
+      get { return hasNoStandardDescriptorAccessor; }
+    }
+    public bool NoStandardDescriptorAccessor {
+      get { return noStandardDescriptorAccessor_; }
+    }
+    
     public const int UninterpretedOptionFieldNumber = 999;
     private pbc::PopsicleList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption> uninterpretedOption_ = new pbc::PopsicleList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption>();
     public scg::IList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption> UninterpretedOptionList {
@@ -4478,6 +4616,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       if (HasMessageSetWireFormat) {
         output.WriteBool(1, MessageSetWireFormat);
       }
+      if (HasNoStandardDescriptorAccessor) {
+        output.WriteBool(2, NoStandardDescriptorAccessor);
+      }
       foreach (global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption element in UninterpretedOptionList) {
         output.WriteMessage(999, element);
       }
@@ -4495,6 +4636,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         if (HasMessageSetWireFormat) {
           size += pb::CodedOutputStream.ComputeBoolSize(1, MessageSetWireFormat);
         }
+        if (HasNoStandardDescriptorAccessor) {
+          size += pb::CodedOutputStream.ComputeBoolSize(2, NoStandardDescriptorAccessor);
+        }
         foreach (global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption element in UninterpretedOptionList) {
           size += pb::CodedOutputStream.ComputeMessageSize(999, element);
         }
@@ -4595,6 +4739,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         if (other.HasMessageSetWireFormat) {
           MessageSetWireFormat = other.MessageSetWireFormat;
         }
+        if (other.HasNoStandardDescriptorAccessor) {
+          NoStandardDescriptorAccessor = other.NoStandardDescriptorAccessor;
+        }
         if (other.uninterpretedOption_.Count != 0) {
           base.AddRange(other.uninterpretedOption_, result.uninterpretedOption_);
         }
@@ -4635,6 +4782,10 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
               MessageSetWireFormat = input.ReadBool();
               break;
             }
+            case 16: {
+              NoStandardDescriptorAccessor = input.ReadBool();
+              break;
+            }
             case 7994: {
               global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
               input.ReadMessage(subBuilder, extensionRegistry);
@@ -4664,6 +4815,24 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         return this;
       }
       
+      public bool HasNoStandardDescriptorAccessor {
+        get { return result.HasNoStandardDescriptorAccessor; }
+      }
+      public bool NoStandardDescriptorAccessor {
+        get { return result.NoStandardDescriptorAccessor; }
+        set { SetNoStandardDescriptorAccessor(value); }
+      }
+      public Builder SetNoStandardDescriptorAccessor(bool value) {
+        result.hasNoStandardDescriptorAccessor = true;
+        result.noStandardDescriptorAccessor_ = value;
+        return this;
+      }
+      public Builder ClearNoStandardDescriptorAccessor() {
+        result.hasNoStandardDescriptorAccessor = false;
+        result.noStandardDescriptorAccessor_ = false;
+        return this;
+      }
+      
       public pbc::IPopsicleList<global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption> UninterpretedOptionList {
         get { return result.uninterpretedOption_; }
       }
@@ -4732,6 +4901,7 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     #region Nested types
     public static class Types {
       public enum CType {
+        STRING = 0,
         CORD = 1,
         STRING_PIECE = 2,
       }
@@ -4741,7 +4911,7 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     
     public const int CtypeFieldNumber = 1;
     private bool hasCtype;
-    private global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType ctype_ = global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType.CORD;
+    private global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType ctype_ = global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType.STRING;
     public bool HasCtype {
       get { return hasCtype; }
     }
@@ -5036,7 +5206,7 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       public Builder ClearCtype() {
         result.hasCtype = false;
-        result.ctype_ = global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType.CORD;
+        result.ctype_ = global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType.STRING;
         return this;
       }
       

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

@@ -0,0 +1,106 @@
+#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/ExtendableBuilderLite.cs

@@ -0,0 +1,262 @@
+#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 Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+  public abstract class ExtendableBuilderLite<TMessage, TBuilder> : GeneratedBuilderLite<TMessage, TBuilder>
+    where TMessage : ExtendableMessageLite<TMessage, TBuilder>
+    where TBuilder : GeneratedBuilderLite<TMessage, TBuilder> {
+
+    protected ExtendableBuilderLite() { }
+
+    /// <summary>
+    /// Checks if a singular extension is present
+    /// </summary>
+    public bool HasExtension<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension) {
+      return MessageBeingBuilt.HasExtension(extension);
+    }
+
+    /// <summary>
+    /// Returns the number of elements in a repeated extension.
+    /// </summary>
+    public int GetExtensionCount<TExtension>(GeneratedExtensionLite<TMessage, IList<TExtension>> extension) {
+      return MessageBeingBuilt.GetExtensionCount(extension);
+    }
+
+    /// <summary>
+    /// Returns the value of an extension.
+    /// </summary>
+    public TExtension GetExtension<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension) {
+      return MessageBeingBuilt.GetExtension(extension);
+    }
+
+    /// <summary>
+    /// Returns one element of a repeated extension.
+    /// </summary>
+    public TExtension GetExtension<TExtension>(GeneratedExtensionLite<TMessage, IList<TExtension>> extension, int index) {
+      return MessageBeingBuilt.GetExtension(extension, index);
+    }
+
+    /// <summary>
+    /// Sets the value of an extension.
+    /// </summary>
+    public TBuilder SetExtension<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension, TExtension value) {
+      ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+      message.VerifyExtensionContainingType(extension);
+      message.Extensions[extension.Descriptor] = extension.ToReflectionType(value);
+      return ThisBuilder;
+    }
+
+    /// <summary>
+    /// Sets the value of one element of a repeated extension.
+    /// </summary>
+    public TBuilder SetExtension<TExtension>(GeneratedExtensionLite<TMessage, IList<TExtension>> extension, int index, TExtension value) {
+      ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+      message.VerifyExtensionContainingType(extension);
+      message.Extensions[extension.Descriptor, index] = extension.SingularToReflectionType(value);
+      return ThisBuilder;
+    }
+
+    /// <summary>
+    /// Appends a value to a repeated extension.
+    /// </summary>
+    public TBuilder AddExtension<TExtension>(GeneratedExtensionLite<TMessage, IList<TExtension>> extension, TExtension value) {
+      ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+      message.VerifyExtensionContainingType(extension);
+      message.Extensions.AddRepeatedField(extension.Descriptor, extension.SingularToReflectionType(value));
+      return ThisBuilder;
+    }
+
+    /// <summary>
+    /// Clears an extension.
+    /// </summary>
+    public TBuilder ClearExtension<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension) {
+      ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+      message.VerifyExtensionContainingType(extension);
+      message.Extensions.ClearField(extension.Descriptor);
+      return ThisBuilder;
+    }
+
+    /// <summary>
+    /// Called by subclasses to parse an unknown field or an extension.
+    /// </summary>
+    /// <returns>true unless the tag is an end-group tag</returns>
+    [CLSCompliant(false)]
+    protected override bool ParseUnknownField(CodedInputStream input,
+        ExtensionRegistry extensionRegistry, uint tag) {
+      FieldSet extensions = MessageBeingBuilt.Extensions;
+
+      WireFormat.WireType wireType = WireFormat.GetTagWireType(tag);
+      int fieldNumber = WireFormat.GetTagFieldNumber(tag);
+      IGeneratedExtensionLite extension = extensionRegistry[DefaultInstanceForType, fieldNumber];
+
+      bool unknown = false;
+      bool packed = false;
+      if (extension == null) {
+        unknown = true;  // Unknown field.
+      } else if (wireType == FieldMappingAttribute.WireTypeFromFieldType(extension.Descriptor.FieldType, false /* isPacked */)) {
+        packed = false;  // Normal, unpacked value.
+      } else if (extension.Descriptor.IsRepeated &&
+                 //?? just returns true ?? extension.Descriptor.type.isPackable() &&
+                 wireType == FieldMappingAttribute.WireTypeFromFieldType(extension.Descriptor.FieldType, true /* isPacked */)) {
+        packed = true;  // Packed value.
+      } else {
+        unknown = true;  // Wrong wire type.
+      }
+
+      if (unknown) {  // Unknown field or wrong wire type.  Skip.
+        return input.SkipField(tag);
+      }
+
+      if (packed) {
+        int length = (int)Math.Min(int.MaxValue, input.ReadRawVarint32());
+        int limit = input.PushLimit(length);
+        if (extension.Descriptor.FieldType == FieldType.Enum) {
+          while (!input.ReachedLimit) {
+            int rawValue = input.ReadEnum();
+            Object value =
+                extension.Descriptor.EnumType.FindValueByNumber(rawValue);
+            if (value == null) {
+              // If the number isn't recognized as a valid value for this
+              // enum, drop it (don't even add it to unknownFields).
+              return true;
+            }
+            extensions.AddRepeatedField(extension.Descriptor, value);
+          }
+        } else {
+          while (!input.ReachedLimit) {
+            Object value = input.ReadPrimitiveField(extension.Descriptor.FieldType);
+            extensions.AddRepeatedField(extension.Descriptor, value);
+          }
+        }
+        input.PopLimit(limit);
+      } else {
+        Object value;
+        switch (extension.Descriptor.MappedType) {
+          case MappedType.Message: {
+            IBuilderLite subBuilder = null;
+            if (!extension.Descriptor.IsRepeated) {
+              IMessageLite existingValue = extensions[extension.Descriptor] as IMessageLite;
+              if (existingValue != null) {
+                subBuilder = existingValue.WeakToBuilder();
+              }
+            }
+            if (subBuilder == null) {
+              subBuilder = extension.MessageDefaultInstance.WeakCreateBuilderForType();
+            }
+            if (extension.Descriptor.FieldType == FieldType.Group) {
+              input.ReadGroup(extension.Number, subBuilder, extensionRegistry);
+            } else {
+              input.ReadMessage(subBuilder, extensionRegistry);
+            }
+            value = subBuilder.WeakBuild();
+            break;
+          }
+          case MappedType.Enum:
+            int rawValue = input.ReadEnum();
+            value = extension.Descriptor.EnumType.FindValueByNumber(rawValue);
+            // If the number isn't recognized as a valid value for this enum,
+            // drop it.
+            if (value == null) {
+              return true;
+            }
+            break;
+          default:
+            value = input.ReadPrimitiveField(extension.Descriptor.FieldType);
+            break;
+        }
+
+        if (extension.Descriptor.IsRepeated) {
+          extensions.AddRepeatedField(extension.Descriptor, value);
+        } else {
+          extensions[extension.Descriptor] = value;
+        }
+      }
+
+      return true;
+    }
+
+    #region Reflection
+
+    public object this[IFieldDescriptorLite field, int index] {
+      set {
+        if (field.IsExtension) {
+          ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+          message.Extensions[field, index] = value;
+        } else {
+          throw new NotSupportedException("Not supported in the lite runtime.");
+        }
+      }
+    }
+
+    public object this[IFieldDescriptorLite field] {
+      set {
+        if (field.IsExtension) {
+          ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+          message.Extensions[field] = value;
+        } else {
+          throw new NotSupportedException("Not supported in the lite runtime.");
+        }
+      }
+    }
+
+    public TBuilder ClearField(IFieldDescriptorLite field) {
+      if (field.IsExtension) {
+        ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+        message.Extensions.ClearField(field);
+        return ThisBuilder;
+      } else {
+        throw new NotSupportedException("Not supported in the lite runtime.");
+      }
+    }
+
+    public TBuilder AddRepeatedField(IFieldDescriptorLite field, object value) {
+      if (field.IsExtension) {
+        ExtendableMessageLite<TMessage, TBuilder> message = MessageBeingBuilt;
+        message.Extensions.AddRepeatedField(field, value);
+        return ThisBuilder;
+      } else {
+        throw new NotSupportedException("Not supported in the lite runtime.");
+      }
+    }
+
+    protected void MergeExtensionFields(ExtendableMessageLite<TMessage, TBuilder> other) {
+      MessageBeingBuilt.Extensions.MergeFrom(other.Extensions);
+    }
+    #endregion
+  }
+}

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/ExtendableMessageLite.cs

@@ -0,0 +1,184 @@
+#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 Google.ProtocolBuffers.Collections;
+
+namespace Google.ProtocolBuffers {
+  public abstract class ExtendableMessageLite<TMessage, TBuilder> : GeneratedMessageLite<TMessage, TBuilder>
+    where TMessage : GeneratedMessageLite<TMessage, TBuilder>
+    where TBuilder : GeneratedBuilderLite<TMessage, TBuilder> {
+
+    protected ExtendableMessageLite() { }
+    private readonly FieldSet extensions = FieldSet.CreateInstance();
+
+    /// <summary>
+    /// Access for the builder.
+    /// </summary>
+    internal FieldSet Extensions {
+      get { return extensions; }
+    }
+
+    public override bool Equals(object obj) {
+      ExtendableMessageLite<TMessage, TBuilder> other = obj as ExtendableMessageLite<TMessage, TBuilder>;
+      return !ReferenceEquals(null, other) &&
+        Dictionaries.Equals(extensions.AllFields, other.extensions.AllFields);
+    }
+
+    public override int GetHashCode() {
+      return Dictionaries.GetHashCode(extensions.AllFields);
+    }
+
+    /// <summary>
+    /// writes the extensions to the text stream
+    /// </summary>
+    public override void PrintTo(System.IO.TextWriter writer) {
+      foreach (KeyValuePair<IFieldDescriptorLite, object> entry in extensions.AllFields) {
+        string fn = string.Format("[{0}]", entry.Key.FullName);
+        if (entry.Key.IsRepeated) {
+          foreach (object o in ((IEnumerable)entry.Value))
+            PrintField(fn, true, o, writer);
+        } else {
+          PrintField(fn, true, entry.Value, writer);
+        }
+      }
+    }
+
+    /// <summary>
+    /// Checks if a singular extension is present.
+    /// </summary>
+    public bool HasExtension<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension) {
+      VerifyExtensionContainingType(extension);
+      return extensions.HasField(extension.Descriptor);
+    }
+
+    /// <summary>
+    /// Returns the number of elements in a repeated extension.
+    /// </summary>
+    public int GetExtensionCount<TExtension>(GeneratedExtensionLite<TMessage, IList<TExtension>> extension) {
+      VerifyExtensionContainingType(extension);
+      return extensions.GetRepeatedFieldCount(extension.Descriptor);
+    }
+
+    /// <summary>
+    /// Returns the value of an extension.
+    /// </summary>
+    public TExtension GetExtension<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension) {
+      VerifyExtensionContainingType(extension);
+      object value = extensions[extension.Descriptor];
+      if (value == null) {
+        return extension.DefaultValue;
+      } else {
+        return (TExtension)extension.FromReflectionType(value);
+      }
+    }
+
+    /// <summary>
+    /// Returns one element of a repeated extension.
+    /// </summary>
+    public TExtension GetExtension<TExtension>(GeneratedExtensionLite<TMessage, IList<TExtension>> extension, int index) {
+      VerifyExtensionContainingType(extension);
+      return (TExtension)extension.SingularFromReflectionType(extensions[extension.Descriptor, index]);
+    }
+
+    /// <summary>
+    /// Called to check if all extensions are initialized.
+    /// </summary>
+    protected bool ExtensionsAreInitialized {
+      get { return extensions.IsInitialized; }
+    }
+
+    public override bool IsInitialized {
+      get {
+        return ExtensionsAreInitialized;
+      }
+    }
+
+    /// <summary>
+    /// Used by subclasses to serialize extensions. Extension ranges may be
+    /// interleaves with field numbers, but we must write them in canonical
+    /// (sorted by field number) order. This class helps us to write individual
+    /// ranges of extensions at once.
+    /// 
+    /// TODO(jonskeet): See if we can improve this in terms of readability.
+    /// </summary>
+    protected class ExtensionWriter {
+      readonly IEnumerator<KeyValuePair<IFieldDescriptorLite, object>> iterator;
+      readonly FieldSet extensions;
+      KeyValuePair<IFieldDescriptorLite, object>? next = null;
+
+      internal ExtensionWriter(ExtendableMessageLite<TMessage, TBuilder> message) {
+        extensions = message.extensions;
+        iterator = message.extensions.GetEnumerator();
+        if (iterator.MoveNext()) {
+          next = iterator.Current;
+        }
+      }
+
+      public void WriteUntil(int end, CodedOutputStream output) {
+        while (next != null && next.Value.Key.FieldNumber < end) {
+          extensions.WriteField(next.Value.Key, next.Value.Value, output);
+          if (iterator.MoveNext()) {
+            next = iterator.Current;
+          } else {
+            next = null;
+          }
+        }
+      }
+    }
+
+    protected ExtensionWriter CreateExtensionWriter(ExtendableMessageLite<TMessage, TBuilder> message) {
+      return new ExtensionWriter(message);
+    }
+
+    /// <summary>
+    /// Called by subclasses to compute the size of extensions.
+    /// </summary>
+    protected int ExtensionsSerializedSize {
+      get { return extensions.SerializedSize; }
+    }
+
+    internal void VerifyExtensionContainingType<TExtension>(GeneratedExtensionLite<TMessage, TExtension> extension) {
+      if (!ReferenceEquals(extension.ContainingTypeDefaultInstance, DefaultInstanceForType)) {
+        // This can only happen if someone uses unchecked operations.
+        throw new ArgumentException(
+          String.Format("Extension is for type \"{0}\" which does not match message type \"{1}\".",
+          extension.ContainingTypeDefaultInstance, DefaultInstanceForType
+          ));
+      }
+    }
+  }
+}

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
   }
 }

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/ExtensionRegistryLite.cs

@@ -0,0 +1,179 @@
+#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.Generic;
+using System;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// A table of known extensions, searchable by name or field number.  When
+  /// parsing a protocol message that might have extensions, you must provide
+  /// an <see cref="ExtensionRegistry"/> in which you have registered any extensions
+  /// that you want to be able to parse.  Otherwise, those extensions will just
+  /// be treated like unknown fields.
+  /// </summary>
+  /// <example>
+  /// For example, if you had the <c>.proto</c> file:
+  /// <code>
+  /// option java_class = "MyProto";
+  ///
+  /// message Foo {
+  ///   extensions 1000 to max;
+  /// }
+  ///
+  /// extend Foo {
+  ///   optional int32 bar;
+  /// }
+  /// </code>
+  ///
+  /// Then you might write code like:
+  ///
+  /// <code>
+  /// extensionRegistry registry = extensionRegistry.CreateInstance();
+  /// registry.Add(MyProto.Bar);
+  /// MyProto.Foo message = MyProto.Foo.ParseFrom(input, registry);
+  /// </code>
+  /// </example>
+  ///
+  /// <remarks>
+  /// <para>You might wonder why this is necessary. Two alternatives might come to
+  /// mind. First, you might imagine a system where generated extensions are
+  /// automatically registered when their containing classes are loaded. This
+  /// is a popular technique, but is bad design; among other things, it creates a
+  /// situation where behavior can change depending on what classes happen to be
+  /// loaded. It also introduces a security vulnerability, because an
+  /// unprivileged class could cause its code to be called unexpectedly from a
+  /// privileged class by registering itself as an extension of the right type.
+  /// </para>
+  /// <para>Another option you might consider is lazy parsing: do not parse an
+  /// extension until it is first requested, at which point the caller must
+  /// provide a type to use. This introduces a different set of problems. First,
+  /// it would require a mutex lock any time an extension was accessed, which
+  /// would be slow. Second, corrupt data would not be detected until first
+  /// access, at which point it would be much harder to deal with it. Third, it
+  /// could violate the expectation that message objects are immutable, since the
+  /// type provided could be any arbitrary message class. An unprivileged user
+  /// could take advantage of this to inject a mutable object into a message
+  /// belonging to privileged code and create mischief.</para>
+  /// </remarks>
+  public sealed partial class ExtensionRegistry {
+    private readonly IDictionary<ExtensionIntPair, IGeneratedExtensionLite> extensionsByNumber;
+    private readonly bool readOnly;
+
+    private ExtensionRegistry(IDictionary<ExtensionIntPair, IGeneratedExtensionLite> extensionsByNumber,
+        bool readOnly) {
+      this.extensionsByNumber = extensionsByNumber;
+      this.readOnly = readOnly;
+    }
+
+#if LITE
+    private static readonly ExtensionRegistry empty = new ExtensionRegistry(
+        new Dictionary<ExtensionIntPair, IGeneratedExtensionLite>(),
+        true);
+
+    /// <summary>
+    /// Construct a new, empty instance.
+    /// </summary>
+    public static ExtensionRegistry CreateInstance() {
+      return new ExtensionRegistry(
+        new Dictionary<ExtensionIntPair, IGeneratedExtensionLite>(), false);
+    }
+    public ExtensionRegistry AsReadOnly() {
+      return new ExtensionRegistry(extensionsByNumber, true);
+    }
+
+#endif
+
+    /// <summary>
+    /// Get the unmodifiable singleton empty instance.
+    /// </summary>
+    public static ExtensionRegistry Empty {
+      get { return empty; }
+    }
+
+    /// <summary>
+    /// Finds an extension by containing type and field number.
+    /// A null reference is returned if the extension can't be found.
+    /// </summary>
+    public IGeneratedExtensionLite this[IMessageLite containingType, int fieldNumber] {
+      get {
+        IGeneratedExtensionLite ret;
+        extensionsByNumber.TryGetValue(new ExtensionIntPair(containingType, fieldNumber), out ret);
+        return ret;
+      }
+    }
+
+    /// <summary>
+    /// Add an extension from a generated file to the registry.
+    /// </summary>
+    public void Add(IGeneratedExtensionLite extension) {
+      if (readOnly) {
+        throw new InvalidOperationException("Cannot add entries to a read-only extension registry");
+      }
+      extensionsByNumber.Add(
+        new ExtensionIntPair(extension.ContainingType, extension.Number),
+        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 ExtensionIntPair : IEquatable<ExtensionIntPair> {
+      readonly object msgType;
+      readonly int number;
+
+      internal ExtensionIntPair(object msgType, int number) {
+        this.msgType = msgType;
+        this.number = number;
+      }
+
+      public override int GetHashCode() {
+        return msgType.GetHashCode() * ((1 << 16) - 1) + number;
+      }
+
+      public override bool Equals(object obj) {
+        if (!(obj is ExtensionIntPair)) {
+          return false;
+        }
+        return Equals((ExtensionIntPair)obj);
+      }
+
+      public bool Equals(ExtensionIntPair other) {
+        return msgType.Equals(other.msgType) && 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();
     }
 

src/ProtocolBuffers/FieldSet.cs

@@ -39,6 +39,21 @@ using Google.ProtocolBuffers.Collections;
 using Google.ProtocolBuffers.Descriptors;
 
 namespace Google.ProtocolBuffers {
+
+  public interface IFieldDescriptorLite : IComparable<IFieldDescriptorLite> {
+    bool IsRepeated { get; }
+    bool IsRequired { get; }
+    bool IsPacked { get; }
+    bool IsExtension { get; }
+    bool MessageSetWireFormat { get; } //field.ContainingType.Options.MessageSetWireFormat
+    int FieldNumber { get; }
+    string FullName { get; }
+    IEnumLiteMap EnumType { get; }
+    FieldType FieldType { get; }
+    MappedType MappedType { get; }
+    object DefaultValue { get; }
+  }
+
   /// <summary>
   /// A class which represents an arbitrary set of fields of some message type.
   /// This is used to implement DynamicMessage, and also to represent extensions
@@ -56,17 +71,17 @@ namespace Google.ProtocolBuffers {
   /// </summary>
   internal sealed class FieldSet {
 
-    private static readonly FieldSet defaultInstance = new FieldSet(new Dictionary<FieldDescriptor, object>()).MakeImmutable();
+    private static readonly FieldSet defaultInstance = new FieldSet(new Dictionary<IFieldDescriptorLite, object>()).MakeImmutable();
 
-    private IDictionary<FieldDescriptor, object> fields;
+    private IDictionary<IFieldDescriptorLite, object> fields;
 
-    private FieldSet(IDictionary<FieldDescriptor, object> fields) {
+    private FieldSet(IDictionary<IFieldDescriptorLite, object> fields) {
       this.fields = fields;
     }
 
     public static FieldSet CreateInstance() {
       // Use SortedList to keep fields in the canonical order
-      return new FieldSet(new SortedList<FieldDescriptor, object>());
+      return new FieldSet(new SortedList<IFieldDescriptorLite, object>());
     }
 
     /// <summary>
@@ -85,8 +100,8 @@ namespace Google.ProtocolBuffers {
       }
 
       if (hasRepeats) {
-        var tmp = new SortedList<FieldDescriptor, object>();
-        foreach (KeyValuePair<FieldDescriptor, object> entry in fields) {
+        var tmp = new SortedList<IFieldDescriptorLite, object>();
+        foreach (KeyValuePair<IFieldDescriptorLite, object> entry in fields) {
           IList<object> list = entry.Value as IList<object>;
           tmp[entry.Key] = list == null ? entry.Value : Lists.AsReadOnly(list);
         }
@@ -110,14 +125,26 @@ namespace Google.ProtocolBuffers {
     /// is immutable, the entries may not be (i.e. any repeated values are represented by
     /// mutable lists). The behaviour is not specified if the contents are mutated.
     /// </summary>
-    internal IDictionary<FieldDescriptor, object> AllFields {
+    internal IDictionary<IFieldDescriptorLite, object> AllFields {
       get { return Dictionaries.AsReadOnly(fields); }
     }
-
+#if !LITE
+    /// <summary>
+    /// Force coercion to full descriptor dictionary.
+    /// </summary>
+    internal IDictionary<Descriptors.FieldDescriptor, object> AllFieldDescriptors {
+      get {
+        SortedList<Descriptors.FieldDescriptor, object> copy = new SortedList<Google.ProtocolBuffers.Descriptors.FieldDescriptor, object>();
+        foreach (KeyValuePair<IFieldDescriptorLite, object> fd in fields)
+          copy.Add((Descriptors.FieldDescriptor)fd.Key, fd.Value);
+        return Dictionaries.AsReadOnly(copy); 
+      }
+    }
+#endif
     /// <summary>
-    /// See <see cref="IMessage.HasField"/>.
+    /// See <see cref="IMessageLite.HasField"/>.
     /// </summary>
-    public bool HasField(FieldDescriptor field) {
+    public bool HasField(IFieldDescriptorLite field) {
       if (field.IsRepeated) {
         throw new ArgumentException("HasField() can only be called on non-repeated fields.");
       }
@@ -133,7 +160,7 @@ namespace Google.ProtocolBuffers {
     }
 
     /// <summary>
-    /// See <see cref="IMessage.Item(FieldDescriptor)"/>
+    /// See <see cref="IMessageLite.Item(IFieldDescriptorLite)"/>
     /// </summary>
     /// <remarks>
     /// If the field is not set, the behaviour when fetching this property varies by field type:
@@ -153,7 +180,7 @@ namespace Google.ProtocolBuffers {
     /// to ensure it is of an appropriate type.
     /// </remarks>
     /// 
-    internal object this[FieldDescriptor field] {
+    internal object this[IFieldDescriptorLite field] {
       get {
         object result;
         if (fields.TryGetValue(field, out result)) {
@@ -191,9 +218,9 @@ namespace Google.ProtocolBuffers {
     }
 
     /// <summary>
-    /// See <see cref="IMessage.Item(FieldDescriptor,int)" />
+    /// See <see cref="IMessageLite.Item(IFieldDescriptorLite,int)" />
     /// </summary>
-    internal object this[FieldDescriptor field, int index] {
+    internal object this[IFieldDescriptorLite field, int index] {
       get {
         if (!field.IsRepeated) {
           throw new ArgumentException("Indexer specifying field and index can only be called on repeated fields.");
@@ -217,7 +244,7 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// See <see cref="IBuilder{TMessage, TBuilder}.AddRepeatedField" />
     /// </summary>
-    internal void AddRepeatedField(FieldDescriptor field, object value) {
+    internal void AddRepeatedField(IFieldDescriptorLite field, object value) {
       if (!field.IsRepeated) {
         throw new ArgumentException("AddRepeatedField can only be called on repeated fields.");
       }
@@ -233,12 +260,12 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Returns an enumerator for the field map. Used to write the fields out.
     /// </summary>
-    internal IEnumerator<KeyValuePair<FieldDescriptor, object>> GetEnumerator() {
+    internal IEnumerator<KeyValuePair<IFieldDescriptorLite, object>> GetEnumerator() {
       return fields.GetEnumerator();
     }
 
     /// <summary>
-    /// See <see cref="IMessage.IsInitialized" />
+    /// See <see cref="IMessageLite.IsInitialized" />
     /// </summary>
     /// <remarks>
     /// Since FieldSet itself does not have any way of knowing about
@@ -248,17 +275,17 @@ namespace Google.ProtocolBuffers {
     /// </remarks>
     internal bool IsInitialized {
       get {
-        foreach (KeyValuePair<FieldDescriptor, object> entry in fields) {
-          FieldDescriptor field = entry.Key;
+        foreach (KeyValuePair<IFieldDescriptorLite, object> entry in fields) {
+          IFieldDescriptorLite field = entry.Key;
           if (field.MappedType == MappedType.Message) {
             if (field.IsRepeated) {
-              foreach(IMessage message in (IEnumerable) entry.Value) {
+              foreach(IMessageLite message in (IEnumerable) entry.Value) {
                 if (!message.IsInitialized) {
                   return false;
                 }
               }
             } else {
-              if (!((IMessage) entry.Value).IsInitialized) {
+              if (!((IMessageLite)entry.Value).IsInitialized) {
                 return false;
               }
             }
@@ -273,8 +300,8 @@ namespace Google.ProtocolBuffers {
     /// descriptor are present in this field set, as well as whether
     /// all the embedded messages are themselves initialized.
     /// </summary>
-    internal bool IsInitializedWithRespectTo(MessageDescriptor type) {
-      foreach (FieldDescriptor field in type.Fields) {
+    internal bool IsInitializedWithRespectTo(IEnumerable typeFields) {
+      foreach (IFieldDescriptorLite field in typeFields) {
         if (field.IsRequired && !HasField(field)) {
           return false;
         }
@@ -285,14 +312,14 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// See <see cref="IBuilder{TMessage, TBuilder}.ClearField" />
     /// </summary>
-    public void ClearField(FieldDescriptor field) {
+    public void ClearField(IFieldDescriptorLite field) {
       fields.Remove(field);
     }
 
     /// <summary>
-    /// See <see cref="IMessage.GetRepeatedFieldCount" />
+    /// See <see cref="IMessageLite.GetRepeatedFieldCount" />
     /// </summary>
-    public int GetRepeatedFieldCount(FieldDescriptor field) {
+    public int GetRepeatedFieldCount(IFieldDescriptorLite field) {
       if (!field.IsRepeated) {
         throw new ArgumentException("GetRepeatedFieldCount() can only be called on repeated fields.");
       }
@@ -300,64 +327,63 @@ namespace Google.ProtocolBuffers {
       return ((IList<object>) this[field]).Count;
     }
 
+#if !LITE
+    /// <summary>
+    /// See <see cref="IBuilder{TMessage, TBuilder}.MergeFrom(IMessageLite)" />
+    /// </summary>
+    public void MergeFrom(IMessage other) {
+      foreach (KeyValuePair<Descriptors.FieldDescriptor, object> fd in other.AllFields)
+        MergeField(fd.Key, fd.Value);
+    }
+#endif
+
     /// <summary>
     /// Implementation of both <c>MergeFrom</c> methods.
     /// </summary>
     /// <param name="otherFields"></param>
-    private void MergeFields(IEnumerable<KeyValuePair<FieldDescriptor, object>> otherFields) {
+    public void MergeFrom(FieldSet other) {
       // Note:  We don't attempt to verify that other's fields have valid
       //   types.  Doing so would be a losing battle.  We'd have to verify
       //   all sub-messages as well, and we'd have to make copies of all of
       //   them to insure that they don't change after verification (since
-      //   the IMessage interface itself cannot enforce immutability of
+      //   the IMessageLite interface itself cannot enforce immutability of
       //   implementations).
       // TODO(jonskeet):  Provide a function somewhere called MakeDeepCopy()
       //   which allows people to make secure deep copies of messages.
 
-      foreach (KeyValuePair<FieldDescriptor, object> entry in otherFields) {
-        FieldDescriptor field = entry.Key;
-        object existingValue;
-        fields.TryGetValue(field, out existingValue);
-        if (field.IsRepeated) {
-          if (existingValue == null) {
-            existingValue = new List<object>();
-            fields[field] = existingValue;
-          }
-          IList<object> list = (IList<object>) existingValue;
-          foreach (object otherValue in (IEnumerable) entry.Value) {
-            list.Add(otherValue);
-          }
-        } else if (field.MappedType == MappedType.Message && existingValue != null) {
-          IMessage existingMessage = (IMessage)existingValue;
-          IMessage merged = existingMessage.WeakToBuilder()
-              .WeakMergeFrom((IMessage) entry.Value)
-              .WeakBuild();
-          this[field] = merged;
-        } else {
-          this[field] = entry.Value;
-        }
+      foreach (KeyValuePair<IFieldDescriptorLite, object> entry in other.fields) {
+        MergeField(entry.Key, entry.Value);
       }
     }
 
-    /// <summary>
-    /// See <see cref="IBuilder{TMessage, TBuilder}.MergeFrom(IMessage)" />
-    /// </summary>
-    public void MergeFrom(IMessage other) {
-      MergeFields(other.AllFields);
-    }
-
-    /// <summary>
-    /// Like <see cref="MergeFrom(IMessage)"/>, but merges from another <c>FieldSet</c>.
-    /// </summary>
-    public void MergeFrom(FieldSet other) {
-      MergeFields(other.fields);
+    private void MergeField(IFieldDescriptorLite field, object mergeValue) {
+      object existingValue;
+      fields.TryGetValue(field, out existingValue);
+      if (field.IsRepeated) {
+        if (existingValue == null) {
+          existingValue = new List<object>();
+          fields[field] = existingValue;
+        }
+        IList<object> list = (IList<object>) existingValue;
+        foreach (object otherValue in (IEnumerable)mergeValue) {
+          list.Add(otherValue);
+        }
+      } else if (field.MappedType == MappedType.Message && existingValue != null) {
+        IMessageLite existingMessage = (IMessageLite)existingValue;
+        IMessageLite merged = existingMessage.WeakToBuilder()
+          .WeakMergeFrom((IMessageLite)mergeValue)
+          .WeakBuild();
+        this[field] = merged;
+      } else {
+        this[field] = mergeValue;
+      }
     }
 
     /// <summary>
-    /// See <see cref="IMessage.WriteTo(CodedOutputStream)" />.
+    /// See <see cref="IMessageLite.WriteTo(CodedOutputStream)" />.
     /// </summary>
     public void WriteTo(CodedOutputStream output) {
-      foreach (KeyValuePair<FieldDescriptor, object> entry in fields) {
+      foreach (KeyValuePair<IFieldDescriptorLite, object> entry in fields) {
         WriteField(entry.Key, entry.Value, output);
       }
     }
@@ -365,9 +391,9 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Writes a single field to a CodedOutputStream.
     /// </summary>
-    public void WriteField(FieldDescriptor field, Object value, CodedOutputStream output) {
-      if (field.IsExtension && field.ContainingType.Options.MessageSetWireFormat) {
-        output.WriteMessageSetExtension(field.FieldNumber, (IMessage) value);
+    public void WriteField(IFieldDescriptorLite field, Object value, CodedOutputStream output) {
+      if (field.IsExtension && field.MessageSetWireFormat) {
+        output.WriteMessageSetExtension(field.FieldNumber, (IMessageLite) value);
       } else {
         if (field.IsRepeated) {
           IEnumerable valueList = (IEnumerable) value;
@@ -395,18 +421,18 @@ namespace Google.ProtocolBuffers {
     }
 
     /// <summary>
-    /// See <see cref="IMessage.SerializedSize" />. It's up to the caller to
+    /// See <see cref="IMessageLite.SerializedSize" />. It's up to the caller to
     /// cache the resulting size if desired.
     /// </summary>
     public int SerializedSize {
       get {
         int size = 0;
-        foreach (KeyValuePair<FieldDescriptor, object> entry in fields) {
-          FieldDescriptor field = entry.Key;
+        foreach (KeyValuePair<IFieldDescriptorLite, object> entry in fields) {
+          IFieldDescriptorLite field = entry.Key;
           object value = entry.Value;
 
-          if (field.IsExtension && field.ContainingType.Options.MessageSetWireFormat) {
-            size += CodedOutputStream.ComputeMessageSetExtensionSize(field.FieldNumber, (IMessage)value);
+          if (field.IsExtension && field.MessageSetWireFormat) {
+            size += CodedOutputStream.ComputeMessageSetExtensionSize(field.FieldNumber, (IMessageLite)value);
           } else {
             if (field.IsRepeated) {
               IEnumerable valueList = (IEnumerable)value;
@@ -440,7 +466,7 @@ namespace Google.ProtocolBuffers {
     /// </remarks>
     /// <exception cref="ArgumentException">The value is not of the right type.</exception>
     /// <exception cref="ArgumentNullException">The value is null.</exception>
-    private static void VerifyType(FieldDescriptor field, object value) {
+    private static void VerifyType(IFieldDescriptorLite field, object value) {
       ThrowHelper.ThrowIfNull(value, "value");
       bool isValid = false;
       switch (field.MappedType) {
@@ -454,12 +480,17 @@ namespace Google.ProtocolBuffers {
         case MappedType.String:      isValid = value is string; break;
         case MappedType.ByteString:  isValid = value is ByteString; break;        
         case MappedType.Enum:
-          EnumValueDescriptor enumValue = value as EnumValueDescriptor;
-          isValid = enumValue != null && enumValue.EnumDescriptor == field.EnumType;
+          IEnumLite enumValue = value as IEnumLite;
+          isValid = enumValue != null && field.EnumType.IsValidValue(enumValue);
           break;
         case MappedType.Message:
-          IMessage messageValue = value as IMessage;
-          isValid = messageValue != null && messageValue.DescriptorForType == field.MessageType;
+          IMessageLite messageValue = value as IMessageLite;
+          isValid = messageValue != null;
+#if !LITE
+          if (isValid && messageValue is IMessage && field is FieldDescriptor) {
+            isValid = ((IMessage) messageValue).DescriptorForType == ((FieldDescriptor) field).MessageType;
+          }
+#endif
           break;
       }
 
@@ -468,10 +499,16 @@ namespace Google.ProtocolBuffers {
         // the stack trace which exact call failed, since the whole chain is
         // considered one line of code.  So, let's make sure to include the
         // field name and other useful info in the exception.
-        throw new ArgumentException("Wrong object type used with protocol message reflection. "
-            + "Message type \"" + field.ContainingType.FullName
-            + "\", field \"" + (field.IsExtension ? field.FullName : field.Name)
-            + "\", value was type \"" + value.GetType().Name + "\".");
+        string message = "Wrong object type used with protocol message reflection.";
+#if !LITE
+        Google.ProtocolBuffers.Descriptors.FieldDescriptor fieldinfo = field as Google.ProtocolBuffers.Descriptors.FieldDescriptor;
+        if (fieldinfo != null) {
+          message += "Message type \"" + fieldinfo.ContainingType.FullName;
+          message += "\", field \"" + (fieldinfo.IsExtension ? fieldinfo.FullName : fieldinfo.Name);
+          message += "\", value was type \"" + value.GetType().Name + "\".";
+        }
+#endif
+        throw new ArgumentException(message);
       }
     }     
   }

src/ProtocolBuffers/GeneratedBuilder.cs

@@ -148,16 +148,20 @@ namespace Google.ProtocolBuffers {
           }
         } else if (field.MappedType == MappedType.Message && HasField(field)) {
           // Merge singular embedded messages
-          IMessage oldValue = (IMessage)this[field];
+          IMessageLite oldValue = (IMessageLite)this[field];
           this[field] = oldValue.WeakCreateBuilderForType()
               .WeakMergeFrom(oldValue)
-              .WeakMergeFrom((IMessage)entry.Value)
+              .WeakMergeFrom((IMessageLite)entry.Value)
               .WeakBuildPartial();
         } else {
           // Just overwrite
           this[field] = entry.Value;
         }
       }
+
+      //Fix for unknown fields not merging, see java's AbstractMessage.Builder<T> line 236
+      MergeUnknownFields(other.UnknownFields);
+
       return ThisBuilder;
     }
 

src/ProtocolBuffers/GeneratedBuilderLite.cs

@@ -0,0 +1,117 @@
+#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;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// All generated protocol message builder classes extend this class. It implements
+  /// most of the IBuilder interface using reflection. Users can ignore this class
+  /// as an implementation detail.
+  /// </summary>
+  public abstract class GeneratedBuilderLite<TMessage, TBuilder> : AbstractBuilderLite<TMessage, TBuilder>
+    where TMessage : GeneratedMessageLite<TMessage, TBuilder>
+    where TBuilder : GeneratedBuilderLite<TMessage, TBuilder> {
+
+    /// <summary>
+    /// Returns the message being built at the moment.
+    /// </summary>
+    protected abstract TMessage MessageBeingBuilt { get; }
+
+    public override TBuilder MergeFrom(IMessageLite other) {
+      //do nothing, Lite runtime does not support cross-message merges
+      return ThisBuilder;
+    }
+
+    public abstract TBuilder MergeFrom(TMessage other);
+
+    public override bool IsInitialized {
+      get { return MessageBeingBuilt.IsInitialized; }
+    }
+
+    /// <summary>
+    /// Adds all of the specified values to the given collection.
+    /// </summary>
+    /// <exception cref="ArgumentNullException">Any element of the list is null</exception>
+    protected void AddRange<T>(IEnumerable<T> source, IList<T> destination) {
+      ThrowHelper.ThrowIfNull(source);
+      // We only need to check this for nullable types.
+      if (default(T) == null) {
+        ThrowHelper.ThrowIfAnyNull(source);
+      }
+      List<T> list = destination as List<T>;
+      if (list != null) {
+        list.AddRange(source);
+      } else {
+        foreach (T element in source) {
+          destination.Add(element);
+        }
+      }
+    }
+
+    /// <summary>
+    /// Called by derived classes to parse an unknown field.
+    /// </summary>
+    /// <returns>true unless the tag is an end-group tag</returns>
+    [CLSCompliant(false)]
+    protected virtual bool ParseUnknownField(CodedInputStream input, 
+                                     ExtensionRegistry extensionRegistry, uint tag) {
+      return input.SkipField(tag);
+    }
+
+    /// <summary>
+    /// Like Build(), but will wrap UninitializedMessageException in
+    /// InvalidProtocolBufferException.
+    /// </summary>
+    public TMessage BuildParsed() {
+      if (!IsInitialized) {
+        throw new UninitializedMessageException(MessageBeingBuilt).AsInvalidProtocolBufferException();
+      }
+      return BuildPartial();
+    }
+
+    /// <summary>
+    /// Implementation of <see cref="IBuilder{TMessage, TBuilder}.Build" />.
+    /// </summary>
+    public override TMessage Build() {
+      // If the message is null, we'll throw a more appropriate exception in BuildPartial.
+      if (MessageBeingBuilt != null && !IsInitialized) {
+        throw new UninitializedMessageException(MessageBeingBuilt);
+      }
+      return BuildPartial();
+    }
+  }
+}

src/ProtocolBuffers/GeneratedExtensionBase.cs

@@ -39,6 +39,7 @@ using System.Reflection;
 using Google.ProtocolBuffers.Descriptors;
 
 namespace Google.ProtocolBuffers {
+
   /// <summary>
   /// Base type for all generated extensions.
   /// </summary>
@@ -65,7 +66,7 @@ namespace Google.ProtocolBuffers {
   public abstract class GeneratedExtensionBase<TExtension> {
 
     private readonly FieldDescriptor descriptor;
-    private readonly IMessage messageDefaultInstance;
+    private readonly IMessageLite messageDefaultInstance;
 
     protected GeneratedExtensionBase(FieldDescriptor descriptor, Type singularExtensionType) {
       if (!descriptor.IsExtension) {
@@ -79,7 +80,8 @@ namespace Google.ProtocolBuffers {
         if (defaultInstanceProperty == null) {
           throw new ArgumentException("No public static DefaultInstance property for type " + typeof(TExtension).Name);
         }
-        messageDefaultInstance = (IMessage)defaultInstanceProperty.GetValue(null, null);
+
+        messageDefaultInstance = (IMessageLite)defaultInstanceProperty.GetValue(null, null);
       }
     }
 
@@ -87,10 +89,14 @@ namespace Google.ProtocolBuffers {
       get { return descriptor; }
     }
 
+    public int Number {
+      get { return Descriptor.FieldNumber; }
+    }
+
     /// <summary>
     /// Returns the default message instance for extensions which are message types.
     /// </summary>
-    public IMessage MessageDefaultInstance {
+    public IMessageLite MessageDefaultInstance {
       get { return messageDefaultInstance; }
     }
 
@@ -107,7 +113,7 @@ namespace Google.ProtocolBuffers {
             // This should not happen in normal use.  But, to be nice, we'll
             // copy the message to whatever type the caller was expecting.
             return MessageDefaultInstance.WeakCreateBuilderForType()
-                           .WeakMergeFrom((IMessage)value).WeakBuild();
+                           .WeakMergeFrom((IMessageLite)value).WeakBuild();
           }
         case MappedType.Enum:
           // Just return a boxed int - that can be unboxed to the enum

src/ProtocolBuffers/GeneratedExtensionLite.cs

@@ -0,0 +1,294 @@
+#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 Google.ProtocolBuffers.Collections;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+
+  public interface IGeneratedExtensionLite {
+    int Number { get; }
+    object ContainingType { get; }
+    IMessageLite MessageDefaultInstance { get; }
+    IFieldDescriptorLite Descriptor { get; }
+  }
+
+  public class ExtensionDescriptorLite : IFieldDescriptorLite {
+    private readonly string fullName;
+    private readonly IEnumLiteMap enumTypeMap;
+    private readonly int number;
+    private readonly FieldType type;
+    private readonly bool isRepeated;
+    private readonly bool isPacked;
+    private readonly MappedType mapType;
+    private readonly object defaultValue;
+
+    public ExtensionDescriptorLite(string fullName, IEnumLiteMap enumTypeMap, int number, FieldType type, object defaultValue, bool isRepeated, bool isPacked) {
+      this.fullName = fullName;
+      this.enumTypeMap = enumTypeMap;
+      this.number = number;
+      this.type = type;
+      this.mapType = FieldMappingAttribute.MappedTypeFromFieldType(type);
+      this.isRepeated = isRepeated;
+      this.isPacked = isPacked;
+      this.defaultValue = defaultValue;
+    }
+
+    public string FullName { get { return fullName; } }
+
+    public bool IsRepeated {
+      get { return isRepeated; }
+    }
+
+    public bool IsRequired {
+      get { return false; }
+    }
+
+    public bool IsPacked {
+      get { return isPacked; }
+    }
+
+    public bool IsExtension {
+      get { return true; }
+    }
+
+    /// <summary>
+    /// This is not supported and assertions are made to ensure this does not exist on extensions of Lite types
+    /// </summary>
+    public bool MessageSetWireFormat {
+      get { return false; }
+    }
+
+    public int FieldNumber {
+      get { return number; }
+    }
+
+    public IEnumLiteMap EnumType {
+      get { return enumTypeMap; }
+    }
+
+    public FieldType FieldType {
+      get { return type; }
+    }
+
+    public MappedType MappedType {
+      get { return mapType; }
+    }
+
+    public object DefaultValue {
+      get { return defaultValue; }
+    }
+
+    public int CompareTo(IFieldDescriptorLite other) {
+      return FieldNumber.CompareTo(other.FieldNumber);
+    }
+  }
+
+  public class GeneratedRepeatExtensionLite<TContainingType, TExtensionType> : GeneratedExtensionLite<TContainingType, IList<TExtensionType>>
+    where TContainingType : IMessageLite {
+    public GeneratedRepeatExtensionLite(string fullName, TContainingType containingTypeDefaultInstance,
+      IMessageLite messageDefaultInstance, IEnumLiteMap enumTypeMap, int number, FieldType type, bool isPacked) :
+      base(fullName, containingTypeDefaultInstance, new List<TExtensionType>(), messageDefaultInstance, enumTypeMap, number, type, isPacked) {
+    }
+
+    public override object ToReflectionType(object value) {
+      IList<object> result = new List<object>();
+      foreach (object element in (IEnumerable) value) {
+        result.Add(SingularToReflectionType(element));
+      }
+      return result;
+    }
+
+    public override object FromReflectionType(object value) {
+      // Must convert the whole list.
+      List<TExtensionType> result = new List<TExtensionType>();
+      foreach (object element in (IEnumerable)value) {
+        result.Add((TExtensionType)SingularFromReflectionType(element));
+      }
+      return result;
+    }
+  }
+
+  public class GeneratedExtensionLite<TContainingType, TExtensionType> : IGeneratedExtensionLite
+    where TContainingType : IMessageLite {
+
+    private readonly TContainingType containingTypeDefaultInstance;
+    private readonly TExtensionType defaultValue;
+    private readonly IMessageLite messageDefaultInstance;
+    private readonly ExtensionDescriptorLite descriptor;
+
+    // We can't always initialize a GeneratedExtension when we first construct
+    // it due to initialization order difficulties (namely, the default
+    // instances may not have been constructed yet).  So, we construct an
+    // uninitialized GeneratedExtension once, then call internalInit() on it
+    // later.  Generated code will always call internalInit() on all extensions
+    // as part of the static initialization code, and internalInit() throws an
+    // exception if called more than once, so this method is useless to users.
+    protected GeneratedExtensionLite(
+        TContainingType containingTypeDefaultInstance,
+        TExtensionType defaultValue,
+        IMessageLite messageDefaultInstance,
+        ExtensionDescriptorLite descriptor) {
+      this.containingTypeDefaultInstance = containingTypeDefaultInstance;
+      this.messageDefaultInstance = messageDefaultInstance;
+      this.defaultValue = defaultValue;
+      this.descriptor = descriptor;
+    }
+
+    /** For use by generated code only. */
+    public GeneratedExtensionLite(
+        string fullName,
+        TContainingType containingTypeDefaultInstance,
+        TExtensionType defaultValue,
+        IMessageLite messageDefaultInstance,
+        IEnumLiteMap enumTypeMap,
+        int number,
+        FieldType type)
+      : this(containingTypeDefaultInstance, defaultValue, messageDefaultInstance,
+          new ExtensionDescriptorLite(fullName, enumTypeMap, number, type, defaultValue,
+            false /* isRepeated */, false /* isPacked */)) {
+    }
+
+    private static readonly IList<object> Empty = new object[0];
+    /** Repeating fields: For use by generated code only. */
+    protected GeneratedExtensionLite(
+      string fullName,
+      TContainingType containingTypeDefaultInstance,
+      TExtensionType defaultValue,
+      IMessageLite messageDefaultInstance,
+      IEnumLiteMap enumTypeMap,
+      int number,
+      FieldType type,
+      bool isPacked)
+      : this(containingTypeDefaultInstance, defaultValue, messageDefaultInstance,
+          new ExtensionDescriptorLite(fullName, enumTypeMap, number, type, Empty,
+            true /* isRepeated */, isPacked)) {
+    }
+
+    /// <summary>
+    /// Returns information about this extension
+    /// </summary>
+    public IFieldDescriptorLite Descriptor {
+      get { return descriptor; }
+    } 
+
+    /// <summary>
+    /// Returns the default value for this extension
+    /// </summary>
+    public TExtensionType DefaultValue {
+      get { return defaultValue; }
+    } 
+
+    /// <summary>
+    /// used for the extension registry
+    /// </summary>
+    object IGeneratedExtensionLite.ContainingType {
+      get { return ContainingTypeDefaultInstance; }
+    }
+      /**
+     * Default instance of the type being extended, used to identify that type.
+     */
+    public TContainingType ContainingTypeDefaultInstance {
+      get {
+        return containingTypeDefaultInstance;
+      }
+    }
+
+    /** Get the field number. */
+    public int Number {
+      get {
+        return descriptor.FieldNumber;
+      }
+    }
+    /**
+     * If the extension is an embedded message, this is the default instance of
+     * that type.
+     */
+    public IMessageLite MessageDefaultInstance {
+      get {
+        return messageDefaultInstance;
+      }
+    }
+
+    /// <summary>
+    /// Converts from the type used by the native accessors to the type
+    /// used by reflection accessors. For example, the reflection accessors
+    /// for enums use EnumValueDescriptors but the native accessors use
+    /// the generated enum type.
+    /// </summary>
+    public virtual object ToReflectionType(object value) {
+        return SingularToReflectionType(value);
+    }
+
+    /// <summary>
+    /// Like ToReflectionType(object) but for a single element.
+    /// </summary>
+    public object SingularToReflectionType(object value) {
+      return descriptor.MappedType == MappedType.Enum
+          ? descriptor.EnumType.FindValueByNumber((int)value)
+          : value;
+    }
+
+    public virtual object FromReflectionType(object value) {
+        return SingularFromReflectionType(value);
+    }
+
+    public object SingularFromReflectionType(object value) {
+      switch (Descriptor.MappedType) {
+        case MappedType.Message:
+          if (value is TExtensionType) {
+            return value;
+          } else {
+            // It seems the copy of the embedded message stored inside the
+            // extended message is not of the exact type the user was
+            // expecting.  This can happen if a user defines a
+            // GeneratedExtension manually and gives it a different type.
+            // This should not happen in normal use.  But, to be nice, we'll
+            // copy the message to whatever type the caller was expecting.
+            return MessageDefaultInstance.WeakCreateBuilderForType()
+                           .WeakMergeFrom((IMessageLite)value).WeakBuild();
+          }
+        case MappedType.Enum:
+          // Just return a boxed int - that can be unboxed to the enum
+          IEnumLite enumValue = (IEnumLite)value;
+          return enumValue.Number;
+        default:
+          return value;
+      }
+    }
+  }
+}

src/ProtocolBuffers/GeneratedMessage.cs

@@ -99,13 +99,13 @@ 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) this[field]) {
+              foreach (IMessageLite element in (IEnumerable) this[field]) {
                 if (!element.IsInitialized) {
                   return false;
                 }
               }
             } else {
-              if (HasField(field) && !((IMessage) this[field]).IsInitialized) {
+              if (HasField(field) && !((IMessageLite) this[field]).IsInitialized) {
                 return false;
               }
             }

src/ProtocolBuffers/GeneratedMessageLite.cs

@@ -0,0 +1,132 @@
+#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.Collections;
+using System.Globalization;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// All generated protocol message classes extend this class. It implements
+  /// most of the IMessage interface using reflection. Users
+  /// can ignore this class as an implementation detail.
+  /// </summary>
+  public abstract class GeneratedMessageLite<TMessage, TBuilder> : AbstractMessageLite<TMessage, TBuilder>
+    where TMessage : GeneratedMessageLite<TMessage, TBuilder>
+    where TBuilder : GeneratedBuilderLite<TMessage, TBuilder> {
+
+    protected abstract TMessage ThisMessage { get; }
+
+    public sealed override string ToString() {
+      using (System.IO.StringWriter wtr = new System.IO.StringWriter()) {
+        PrintTo(wtr);
+        return wtr.ToString();
+      }
+    }
+
+    /// <summary>
+    /// PrintTo() helper methods for Lite Runtime
+    /// </summary>
+    protected static void PrintField<T>(string name, IList<T> value, System.IO.TextWriter writer) {
+      foreach (T item in value)
+        PrintField(name, true, (object)item, writer);
+    }
+    /// <summary>
+    /// PrintTo() helper methods for Lite Runtime
+    /// </summary>
+    protected static void PrintField(string name, bool hasValue, object value, System.IO.TextWriter writer) {
+      if (!hasValue) return;
+      if (value is IMessageLite) {
+        writer.WriteLine("{0} {{", name);
+        ((IMessageLite)value).PrintTo(writer);
+        writer.WriteLine("}");
+      } else if (value is ByteString || value is String) {
+        writer.Write("{0}: \"", name);
+        if(value is String)
+          EscapeBytes( System.Text.Encoding.UTF8.GetBytes((string)value), writer);
+        else
+          EscapeBytes(((ByteString)value), writer);
+        writer.WriteLine("\"");
+      } else if (value is bool) {
+        writer.WriteLine("{0}: {1}", name, (bool)value ? "true" : "false");
+      } else if (value is IEnumLite) {
+        writer.WriteLine("{0}: {1}", name, ((IEnumLite)value).Name);
+      }
+      else {
+        writer.WriteLine("{0}: {1}", name, ((IConvertible)value).ToString(CultureInfo.InvariantCulture));
+      }
+    }
+
+    /// <summary>
+    /// COPIED from TextFormat
+    /// Escapes bytes in the format used in protocol buffer text format, which
+    /// is the same as the format used for C string literals.  All bytes
+    /// that are not printable 7-bit ASCII characters are escaped, as well as
+    /// backslash, single-quote, and double-quote characters.  Characters for
+    /// which no defined short-hand escape sequence is defined will be escaped
+    /// using 3-digit octal sequences.
+    /// The returned value is guaranteed to be entirely ASCII.
+    /// </summary>
+    private static void EscapeBytes(IEnumerable<byte> input, System.IO.TextWriter writer) {
+      foreach (byte b in input) {
+        switch (b) {
+          // C# does not use \a or \v
+          case 0x07: writer.Write("\\a"); break;
+          case (byte)'\b': writer.Write("\\b"); break;
+          case (byte)'\f': writer.Write("\\f"); break;
+          case (byte)'\n': writer.Write("\\n"); break;
+          case (byte)'\r': writer.Write("\\r"); break;
+          case (byte)'\t': writer.Write("\\t"); break;
+          case 0x0b: writer.Write("\\v"); break;
+          case (byte)'\\': writer.Write("\\\\"); break;
+          case (byte)'\'': writer.Write("\\\'"); break;
+          case (byte)'"': writer.Write("\\\""); break;
+          default:
+            if (b >= 0x20 && b < 128) {
+              writer.Write((char)b);
+            } else {
+              writer.Write('\\');
+              writer.Write((char)('0' + ((b >> 6) & 3)));
+              writer.Write((char)('0' + ((b >> 3) & 7)));
+              writer.Write((char)('0' + (b & 7)));
+            }
+            break;
+        }
+      }
+    }
+  }
+}

src/ProtocolBuffers/IBuilder.cs

@@ -47,12 +47,12 @@ namespace Google.ProtocolBuffers {
   /// use explicit interface implemenation for the non-generic form. This mirrors
   /// how IEnumerable and IEnumerable<T> work.
   /// </summary>
-  public interface IBuilder {
+  public interface IBuilder : IBuilderLite {
     /// <summary>
     /// Returns true iff all required fields in the message and all
     /// embedded messages are set.
     /// </summary>
-    bool IsInitialized { get; }
+    new bool IsInitialized { get; }
 
     /// <summary>
     /// Only present in the nongeneric interface - useful for tests, but
@@ -119,17 +119,17 @@ namespace Google.ProtocolBuffers {
 
     #region Methods which are like those of the generic form, but without any knowledge of the type parameters
     IBuilder WeakAddRepeatedField(FieldDescriptor field, object value);
-    IBuilder WeakClear();
+    new IBuilder WeakClear();
     IBuilder WeakClearField(FieldDescriptor field);
     IBuilder WeakMergeFrom(IMessage message);
-    IBuilder WeakMergeFrom(ByteString data);
-    IBuilder WeakMergeFrom(ByteString data, ExtensionRegistry registry);
-    IBuilder WeakMergeFrom(CodedInputStream input);
-    IBuilder WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry);
-    IMessage WeakBuild();
-    IMessage WeakBuildPartial();
-    IBuilder WeakClone();
-    IMessage WeakDefaultInstanceForType { get; }
+    new IBuilder WeakMergeFrom(ByteString data);
+    new IBuilder WeakMergeFrom(ByteString data, ExtensionRegistry registry);
+    new IBuilder WeakMergeFrom(CodedInputStream input);
+    new IBuilder WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry);
+    new IMessage WeakBuild();
+    new IMessage WeakBuildPartial();
+    new IBuilder WeakClone();
+    new IMessage WeakDefaultInstanceForType { get; }
     #endregion
   }
 
@@ -139,7 +139,7 @@ namespace Google.ProtocolBuffers {
   /// </summary>
   /// <typeparam name="TMessage">Type of message</typeparam>
   /// <typeparam name="TBuilder">Type of builder</typeparam>
-  public interface IBuilder<TMessage, TBuilder> : IBuilder
+  public interface IBuilder<TMessage, TBuilder> : IBuilder, IBuilderLite<TMessage, TBuilder>
       where TMessage : IMessage<TMessage, TBuilder> 
       where TBuilder : IBuilder<TMessage, TBuilder> {
 
@@ -148,22 +148,7 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Resets all fields to their default values.
     /// </summary>
-    TBuilder Clear();
-
-    /// <summary>
-    /// Merge the specified other message into the message being
-    /// built. Merging occurs as follows. For each field:
-    /// For singular primitive fields, if the field is set in <paramref name="other"/>,
-    /// then <paramref name="other"/>'s value overwrites the value in this message.
-    /// For singular message fields, if the field is set in <paramref name="other"/>,
-    /// it is merged into the corresponding sub-message of this message using the same
-    /// merging rules.
-    /// For repeated fields, the elements in <paramref name="other"/> are concatenated
-    /// with the elements in this message.
-    /// </summary>
-    /// <param name="other"></param>
-    /// <returns></returns>
-    TBuilder MergeFrom(TMessage other);
+    new TBuilder Clear();
 
     /// <summary>
     /// Merge the specified other message which may be a different implementation of
@@ -180,19 +165,19 @@ namespace Google.ProtocolBuffers {
     /// <exception cref="UninitializedMessageException">the message
     /// is missing one or more required fields; use BuildPartial to bypass
     /// this check</exception>
-    TMessage Build();
+    new TMessage Build();
 
     /// <summary>
     /// Like Build(), but does not throw an exception if the message is missing
     /// required fields. Instead, a partial message is returned.
     /// </summary>
-    TMessage BuildPartial();
+    new TMessage BuildPartial();
 
     /// <summary>
     /// Clones this builder.
     /// TODO(jonskeet): Explain depth of clone.
     /// </summary>
-    TBuilder Clone();
+    new TBuilder Clone();
 
     /// <summary>
     /// Parses a message of this type from the input and merges it with this
@@ -213,7 +198,7 @@ namespace Google.ProtocolBuffers {
     /// Use BuildPartial to build, which ignores missing required fields.
     /// </list>
     /// </remarks>
-    TBuilder MergeFrom(CodedInputStream input);
+    new TBuilder MergeFrom(CodedInputStream input);
 
     /// <summary>
     /// Like MergeFrom(CodedInputStream), but also parses extensions.
@@ -221,13 +206,13 @@ namespace Google.ProtocolBuffers {
     /// in <paramref name="extensionRegistry"/>. Extensions not in the registry
     /// will be treated as unknown fields.
     /// </summary>
-    TBuilder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry);
+    new TBuilder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry);
 
     /// <summary>
     /// Get's the message's type's default instance.
     /// <see cref="IMessage{TMessage}.DefaultInstanceForType" />
     /// </summary>
-    TMessage DefaultInstanceForType { get; }
+    new TMessage DefaultInstanceForType { get; }
 
     /// <summary>
     /// Clears the field. This is exactly equivalent to calling the generated
@@ -258,12 +243,12 @@ namespace Google.ProtocolBuffers {
     /// write messages in this format.
     /// </summary>
     /// <param name="input"></param>
-    TBuilder MergeDelimitedFrom(Stream input);
+    new TBuilder MergeDelimitedFrom(Stream input);
 
     /// <summary>
     /// Like MergeDelimitedFrom(Stream) but supporting extensions.
     /// </summary>
-    TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry);
+    new TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry);
 
     #region Convenience methods
     /// <summary>
@@ -271,28 +256,28 @@ namespace Google.ProtocolBuffers {
     /// it with the message being built. This is just a small wrapper around
     /// MergeFrom(CodedInputStream).
     /// </summary>
-    TBuilder MergeFrom(ByteString data);
+    new TBuilder MergeFrom(ByteString data);
 
     /// <summary>
     /// Parse <paramref name="data"/> as a message of this type and merge
     /// it with the message being built. This is just a small wrapper around
-    /// MergeFrom(CodedInputStream, ExtensionRegistry).
+    /// MergeFrom(CodedInputStream, extensionRegistry).
     /// </summary>
-    TBuilder MergeFrom(ByteString data, ExtensionRegistry extensionRegistry);
+    new TBuilder MergeFrom(ByteString data, ExtensionRegistry extensionRegistry);
 
     /// <summary>
     /// Parse <paramref name="data"/> as a message of this type and merge
     /// it with the message being built. This is just a small wrapper around
     /// MergeFrom(CodedInputStream).
     /// </summary>
-    TBuilder MergeFrom(byte[] data);
+    new TBuilder MergeFrom(byte[] data);
 
     /// <summary>
     /// Parse <paramref name="data"/> as a message of this type and merge
     /// it with the message being built. This is just a small wrapper around
-    /// MergeFrom(CodedInputStream, ExtensionRegistry).
+    /// MergeFrom(CodedInputStream, extensionRegistry).
     /// </summary>
-    TBuilder MergeFrom(byte[] data, ExtensionRegistry extensionRegistry);
+    new TBuilder MergeFrom(byte[] data, ExtensionRegistry extensionRegistry);
 
     /// <summary>
     /// Parse <paramref name="input"/> as a message of this type and merge
@@ -304,14 +289,14 @@ namespace Google.ProtocolBuffers {
     /// to write your message and MmergeDelimitedFrom(Stream) to read it.
     /// Despite usually reading the entire stream, this method never closes the stream. 
     /// </summary>
-    TBuilder MergeFrom(Stream input);
+    new TBuilder MergeFrom(Stream input);
 
     /// <summary>
     /// Parse <paramref name="input"/> as a message of this type and merge
     /// it with the message being built. This is just a small wrapper around
-    /// MergeFrom(CodedInputStream, ExtensionRegistry).
+    /// MergeFrom(CodedInputStream, extensionRegistry).
     /// </summary>
-    TBuilder MergeFrom(Stream input, ExtensionRegistry extensionRegistry);
+    new TBuilder MergeFrom(Stream input, ExtensionRegistry extensionRegistry);
     #endregion
   }
 }

src/ProtocolBuffers/IBuilderLite.cs

@@ -0,0 +1,210 @@
+#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.IO;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// Non-generic interface for all members whose signatures don't require knowledge of
+  /// the type being built. The generic interface extends this one. Some methods return
+  /// either an IBuilder or an IMessage; in these cases the generic interface redeclares
+  /// the same method with a type-specific signature. Implementations are encouraged to
+  /// use explicit interface implemenation for the non-generic form. This mirrors
+  /// how IEnumerable and IEnumerable&lt;T&gt; work.
+  /// </summary>
+  public interface IBuilderLite {
+    /// <summary>
+    /// Returns true iff all required fields in the message and all
+    /// embedded messages are set.
+    /// </summary>
+    bool IsInitialized { get; }
+
+    IBuilderLite WeakClear();
+    IBuilderLite WeakMergeFrom(IMessageLite message);
+    IBuilderLite WeakMergeFrom(ByteString data);
+    IBuilderLite WeakMergeFrom(ByteString data, ExtensionRegistry registry);
+    IBuilderLite WeakMergeFrom(CodedInputStream input);
+    IBuilderLite WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry);
+    IMessageLite WeakBuild();
+    IMessageLite WeakBuildPartial();
+    IBuilderLite WeakClone();
+    IMessageLite WeakDefaultInstanceForType { get; }
+  }
+
+  /// <summary>
+  /// Interface implemented by Protocol Message builders.
+  /// TODO(jonskeet): Consider "SetXXX" methods returning the builder, as well as the properties.
+  /// </summary>
+  /// <typeparam name="TMessage">Type of message</typeparam>
+  /// <typeparam name="TBuilder">Type of builder</typeparam>
+  public interface IBuilderLite<TMessage, TBuilder> : IBuilderLite
+      where TMessage : IMessageLite<TMessage, TBuilder> 
+      where TBuilder : IBuilderLite<TMessage, TBuilder> {
+
+    /// <summary>
+    /// Resets all fields to their default values.
+    /// </summary>
+    TBuilder Clear();
+
+    /// <summary>
+    /// Merge the specified other message which may be a different implementation of
+    /// the same message descriptor.
+    /// </summary>
+    TBuilder MergeFrom(IMessageLite other);
+
+    /// <summary>
+    /// Constructs the final message. Once this is called, this Builder instance
+    /// is no longer valid, and calling any other method may throw a
+    /// NullReferenceException. If you need to continue working with the builder
+    /// after calling Build, call Clone first.
+    /// </summary>
+    /// <exception cref="UninitializedMessageException">the message
+    /// is missing one or more required fields; use BuildPartial to bypass
+    /// this check</exception>
+    TMessage Build();
+
+    /// <summary>
+    /// Like Build(), but does not throw an exception if the message is missing
+    /// required fields. Instead, a partial message is returned.
+    /// </summary>
+    TMessage BuildPartial();
+
+    /// <summary>
+    /// Clones this builder.
+    /// TODO(jonskeet): Explain depth of clone.
+    /// </summary>
+    TBuilder Clone();
+
+    /// <summary>
+    /// Parses a message of this type from the input and merges it with this
+    /// message, as if using MergeFrom(IMessage&lt;T&gt;).
+    /// </summary>
+    /// <remarks>
+    /// Warning: This does not verify that all required fields are present
+    /// in the input message. If you call Build() without setting all
+    /// required fields, it will throw an UninitializedMessageException.
+    /// There are a few good ways to deal with this:
+    /// <list>
+    /// <item>Call IsInitialized to verify to verify that all required fields are
+    /// set before building.</item>
+    /// <item>Parse  the message separately using one of the static ParseFrom
+    /// methods, then use MergeFrom(IMessage&lt;T&gt;) to merge it with
+    /// this one. ParseFrom will throw an InvalidProtocolBufferException
+    /// (an IOException) if some required fields are missing.
+    /// Use BuildPartial to build, which ignores missing required fields.
+    /// </list>
+    /// </remarks>
+    TBuilder MergeFrom(CodedInputStream input);
+
+    /// <summary>
+    /// Like MergeFrom(CodedInputStream), but also parses extensions.
+    /// The extensions that you want to be able to parse must be registered
+    /// in <paramref name="extensionRegistry"/>. Extensions not in the registry
+    /// will be treated as unknown fields.
+    /// </summary>
+    TBuilder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry);
+
+    /// <summary>
+    /// Get's the message's type's default instance.
+    /// <see cref="IMessageLite{TMessage}.DefaultInstanceForType" />
+    /// </summary>
+    TMessage DefaultInstanceForType { get; }
+
+    /// <summary>
+    /// Like MergeFrom(Stream), but does not read until the end of the file.
+    /// Instead, the size of the message (encoded as a varint) is read first,
+    /// then the message data. Use Message.WriteDelimitedTo(Stream) to
+    /// write messages in this format.
+    /// </summary>
+    /// <param name="input"></param>
+    TBuilder MergeDelimitedFrom(Stream input);
+
+    /// <summary>
+    /// Like MergeDelimitedFrom(Stream) but supporting extensions.
+    /// </summary>
+    TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry);
+
+    #region Convenience methods
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of this type and merge
+    /// it with the message being built. This is just a small wrapper around
+    /// MergeFrom(CodedInputStream).
+    /// </summary>
+    TBuilder MergeFrom(ByteString data);
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of this type and merge
+    /// it with the message being built. This is just a small wrapper around
+    /// MergeFrom(CodedInputStream, ExtensionRegistry).
+    /// </summary>
+    TBuilder MergeFrom(ByteString data, ExtensionRegistry extensionRegistry);
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of this type and merge
+    /// it with the message being built. This is just a small wrapper around
+    /// MergeFrom(CodedInputStream).
+    /// </summary>
+    TBuilder MergeFrom(byte[] data);
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of this type and merge
+    /// it with the message being built. This is just a small wrapper around
+    /// MergeFrom(CodedInputStream, ExtensionRegistry).
+    /// </summary>
+    TBuilder MergeFrom(byte[] data, ExtensionRegistry extensionRegistry);
+
+    /// <summary>
+    /// Parse <paramref name="input"/> as a message of this type and merge
+    /// it with the message being built. This is just a small wrapper around
+    /// MergeFrom(CodedInputStream). Note that this method always reads
+    /// the entire input (unless it throws an exception). If you want it to
+    /// stop earlier, you will need to wrap the input in a wrapper
+    /// stream which limits reading. Or, use IMessage.WriteDelimitedTo(Stream)
+    /// to write your message and MmergeDelimitedFrom(Stream) to read it.
+    /// Despite usually reading the entire stream, this method never closes the stream. 
+    /// </summary>
+    TBuilder MergeFrom(Stream input);
+
+    /// <summary>
+    /// Parse <paramref name="input"/> as a message of this type and merge
+    /// it with the message being built. This is just a small wrapper around
+    /// MergeFrom(CodedInputStream, ExtensionRegistry).
+    /// </summary>
+    TBuilder MergeFrom(Stream input, ExtensionRegistry extensionRegistry);
+    #endregion
+  }
+}

src/ProtocolBuffers/IMessage.cs

@@ -43,7 +43,7 @@ namespace Google.ProtocolBuffers {
   /// Non-generic interface used for all parts of the API which don't require
   /// any type knowledge.
   /// </summary>
-  public interface IMessage {
+  public interface IMessage : IMessageLite {
     /// <summary>
     /// Returns the message's type's descriptor. This differs from the
     /// Descriptor property of each generated message class in that this
@@ -110,7 +110,7 @@ namespace Google.ProtocolBuffers {
     /// Returns true iff all required fields in the message and all embedded
     /// messages are set.
     /// </summary>
-    bool IsInitialized { get; }
+    new bool IsInitialized { get; }
 
     /// <summary>
     /// Serializes the message and writes it to the given output stream.
@@ -124,7 +124,7 @@ namespace Google.ProtocolBuffers {
     /// 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>
-    void WriteTo(CodedOutputStream output);
+    new void WriteTo(CodedOutputStream output);
 
     /// <summary>
     /// Like WriteTo(Stream) but writes the size of the message as a varint before
@@ -134,13 +134,13 @@ namespace Google.ProtocolBuffers {
     /// YourMessageType.ParseDelimitedFrom(Stream) to parse messages written by this method.
     /// </summary>
     /// <param name="output"></param>
-    void WriteDelimitedTo(Stream output);
+    new void WriteDelimitedTo(Stream output);
 
     /// <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>
-    int SerializedSize { get; }
+    new int SerializedSize { get; }
 
     #region Comparison and hashing
     /// <summary>
@@ -149,13 +149,13 @@ namespace Google.ProtocolBuffers {
     /// (as defined by DescriptorForType) and has identical values
     /// for all its fields.
     /// </summary>
-    bool Equals(object other);
+    new bool Equals(object other);
 
     /// <summary>
     /// Returns the hash code value for this message.
     /// TODO(jonskeet): Specify the hash algorithm, but better than the Java one!
     /// </summary>
-    int GetHashCode();
+    new int GetHashCode();
     #endregion
 
     #region Convenience methods
@@ -163,19 +163,19 @@ namespace Google.ProtocolBuffers {
     /// Converts the message to a string in protocol buffer text format.
     /// This is just a trivial wrapper around TextFormat.PrintToString.
     /// </summary>
-    string ToString();
+    new string ToString();
 
     /// <summary>
     /// Serializes the message to a ByteString. This is a trivial wrapper
     /// around WriteTo(CodedOutputStream).
     /// </summary>
-    ByteString ToByteString();
+    new ByteString ToByteString();
 
     /// <summary>
     /// Serializes the message to a byte array. This is a trivial wrapper
     /// around WriteTo(CodedOutputStream).
     /// </summary>
-    byte[] ToByteArray();
+    new byte[] ToByteArray();
 
     /// <summary>
     /// Serializes the message and writes it to the given stream.
@@ -183,7 +183,7 @@ namespace Google.ProtocolBuffers {
     /// does not flush or close the stream.
     /// </summary>
     /// <param name="output"></param>
-    void WriteTo(Stream output);
+    new void WriteTo(Stream output);
     #endregion
 
     /// <summary>
@@ -191,19 +191,19 @@ namespace Google.ProtocolBuffers {
     /// is typically implemented by strongly typed messages by just returning
     /// the result of CreateBuilderForType.
     /// </summary>
-    IBuilder WeakCreateBuilderForType();
+    new IBuilder WeakCreateBuilderForType();
 
     /// <summary>
     /// Creates a builder with the same contents as this message. This
     /// is typically implemented by strongly typed messages by just returning
     /// the result of ToBuilder.
     /// </summary>
-    IBuilder WeakToBuilder();
+    new IBuilder WeakToBuilder();
 
-    IMessage WeakDefaultInstanceForType { get; }
+    new IMessage WeakDefaultInstanceForType { get; }
   }
 
-  public interface IMessage<TMessage> : IMessage {
+  public interface IMessage<TMessage> : IMessage, IMessageLite<TMessage> {
     /// <summary>
     /// Returns an instance of this message type with all fields set to
     /// their default values. This may or may not be a singleton. This differs
@@ -211,26 +211,26 @@ namespace Google.ProtocolBuffers {
     /// method is an abstract method of IMessage whereas DefaultInstance is
     /// a static property of a specific class. They return the same thing.
     /// </summary>
-    TMessage DefaultInstanceForType { get; }
+    new TMessage DefaultInstanceForType { get; }
   }
 
   /// <summary>
   /// Type-safe interface for all generated messages to implement.
   /// </summary>
-  public interface IMessage<TMessage, TBuilder> : IMessage<TMessage>
+  public interface IMessage<TMessage, TBuilder> : IMessage<TMessage>, IMessageLite<TMessage, TBuilder>
       where TMessage : IMessage<TMessage, TBuilder> 
       where TBuilder : IBuilder<TMessage, TBuilder> {
     #region Builders
     /// <summary>
     /// Constructs a new builder for a message of the same type as this message.
     /// </summary>
-    TBuilder CreateBuilderForType();
+    new TBuilder CreateBuilderForType();
     /// <summary>
     /// Creates a builder with the same contents as this current instance.
     /// This is typically implemented by strongly typed messages by just
     /// returning the result of ToBuilder().
     /// </summary>
-    TBuilder ToBuilder();
+    new TBuilder ToBuilder();
     #endregion
   }
 }

src/ProtocolBuffers/IMessageLite.cs

@@ -0,0 +1,179 @@
+#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.IO;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// Non-generic interface used for all parts of the API which don't require
+  /// any type knowledge.
+  /// </summary>
+  public interface IMessageLite {
+
+    /// <summary>
+    /// Returns true iff all required fields in the message and all embedded
+    /// messages are set.
+    /// </summary>
+    bool IsInitialized { get; }
+
+    /// <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>
+    void WriteTo(CodedOutputStream output);
+
+    /// <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>
+    void WriteDelimitedTo(Stream output);
+
+    /// <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>
+    int SerializedSize { get; }
+
+    #region Comparison and hashing
+    /// <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>
+    bool Equals(object other);
+
+    /// <summary>
+    /// Returns the hash code value for this message.
+    /// TODO(jonskeet): Specify the hash algorithm, but better than the Java one!
+    /// </summary>
+    int GetHashCode();
+    #endregion
+
+    #region Convenience methods
+    /// <summary>
+    /// Converts the message to a string in protocol buffer text format.
+    /// This is just a trivial wrapper around TextFormat.PrintToString.
+    /// </summary>
+    string ToString();
+
+    /// <summary>
+    /// Converts the message to a string.
+    /// </summary>
+    void PrintTo(TextWriter writer);
+
+    /// <summary>
+    /// Serializes the message to a ByteString. This is a trivial wrapper
+    /// around WriteTo(CodedOutputStream).
+    /// </summary>
+    ByteString ToByteString();
+
+    /// <summary>
+    /// Serializes the message to a byte array. This is a trivial wrapper
+    /// around WriteTo(CodedOutputStream).
+    /// </summary>
+    byte[] ToByteArray();
+
+    /// <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>
+    void WriteTo(Stream output);
+    #endregion
+
+    /// <summary>
+    /// Creates a builder for the type, but in a weakly typed manner. This
+    /// is typically implemented by strongly typed messages by just returning
+    /// the result of CreateBuilderForType.
+    /// </summary>
+    IBuilderLite WeakCreateBuilderForType();
+
+    /// <summary>
+    /// Creates a builder with the same contents as this message. This
+    /// is typically implemented by strongly typed messages by just returning
+    /// the result of ToBuilder.
+    /// </summary>
+    IBuilderLite WeakToBuilder();
+
+    IMessageLite WeakDefaultInstanceForType { get; }
+  }
+
+  public interface IMessageLite<TMessage> : IMessageLite {
+    /// <summary>
+    /// Returns an instance of this message type with all fields set to
+    /// their default values. This may or may not be a singleton. This differs
+    /// from the DefaultInstance property of each generated message class in that this
+    /// method is an abstract method of IMessage whereas DefaultInstance is
+    /// a static property of a specific class. They return the same thing.
+    /// </summary>
+    TMessage DefaultInstanceForType { get; }
+  }
+
+  /// <summary>
+  /// Type-safe interface for all generated messages to implement.
+  /// </summary>
+  public interface IMessageLite<TMessage, TBuilder> : IMessageLite<TMessage>
+      where TMessage : IMessageLite<TMessage, TBuilder> 
+      where TBuilder : IBuilderLite<TMessage, TBuilder> {
+    #region Builders
+    /// <summary>
+    /// Constructs a new builder for a message of the same type as this message.
+    /// </summary>
+    TBuilder CreateBuilderForType();
+    /// <summary>
+    /// Creates a builder with the same contents as this current instance.
+    /// This is typically implemented by strongly typed messages by just
+    /// returning the result of ToBuilder().
+    /// </summary>
+    TBuilder ToBuilder();
+    #endregion
+  }
+}

src/ProtocolBuffers/Properties/AssemblyInfo.cs

@@ -74,6 +74,12 @@ using System.Runtime.CompilerServices;
 "72f738140072bb69990bc4f98a21365de2c105e848974a3d210e938b0a56103c0662901efd6b78"+
 "0ee6dbe977923d46a8fda18fb25c65dd73b149a5cd9f3100668b56649932dadd8cf5be52eb1dce"+
 "ad5cedbf")]
+[assembly: InternalsVisibleTo("Google.ProtocolBuffersLite.Test,PublicKey=" +
+"00240000048000009400000006020000002400005253413100040000010001008179f2dd31a648" +
+"2a2359dbe33e53701167a888e7c369a9ae3210b64f93861d8a7d286447e58bc167e3d99483beda" +
+"72f738140072bb69990bc4f98a21365de2c105e848974a3d210e938b0a56103c0662901efd6b78" +
+"0ee6dbe977923d46a8fda18fb25c65dd73b149a5cd9f3100668b56649932dadd8cf5be52eb1dce" +
+"ad5cedbf")]
 [assembly: InternalsVisibleTo("ProtoGen,PublicKey=" +
 "00240000048000009400000006020000002400005253413100040000010001006d739020e13bdc" +
 "038e86fa8aa5e1b13aae65d3ae79d622816c6067ab5b6955be50cc887130117582349208c13a55" +

src/ProtocolBuffers/ProtocolBuffers.csproj

@@ -80,10 +80,18 @@
   <ItemGroup>
     <Reference Include="mscorlib" />
     <Reference Include="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AbstractBuilder.cs" />
+    <Compile Include="AbstractBuilderLite.cs">
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="AbstractMessage.cs" />
+    <Compile Include="AbstractMessageLite.cs">
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="ByteString.cs" />
     <Compile Include="Collections\Enumerables.cs" />
     <Compile Include="Collections\IPopsicleList.cs" />
@@ -116,10 +124,16 @@
     <Compile Include="Descriptors\PackageDescriptor.cs" />
     <Compile Include="Descriptors\ServiceDescriptor.cs" />
     <Compile Include="DynamicMessage.cs" />
+    <Compile Include="EnumLite.cs" />
     <Compile Include="ExtendableBuilder.cs" />
+    <Compile Include="ExtendableBuilderLite.cs" />
     <Compile Include="ExtendableMessage.cs" />
-    <Compile Include="ExtensionInfo.cs" />
+    <Compile Include="ExtendableMessageLite.cs" />
+    <Compile Include="ExtensionInfo.cs">
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="ExtensionRegistry.cs" />
+    <Compile Include="ExtensionRegistryLite.cs" />
     <Compile Include="FieldAccess\ReflectionUtil.cs" />
     <Compile Include="FieldAccess\SingleEnumAccessor.cs" />
     <Compile Include="FieldAccess\SingleMessageAccessor.cs" />
@@ -131,12 +145,19 @@
     <Compile Include="FieldAccess\RepeatedMessageAccessor.cs" />
     <Compile Include="FieldSet.cs" />
     <Compile Include="GeneratedBuilder.cs" />
+    <Compile Include="GeneratedBuilderLite.cs" />
+    <Compile Include="GeneratedExtensionLite.cs" />
+    <Compile Include="GeneratedMessageLite.cs" />
     <Compile Include="GeneratedRepeatExtension.cs" />
     <Compile Include="GeneratedSingleExtension.cs" />
     <Compile Include="GeneratedMessage.cs" />
     <Compile Include="IBuilder.cs" />
     <Compile Include="GeneratedExtensionBase.cs" />
+    <Compile Include="IBuilderLite.cs">
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="IMessage.cs" />
+    <Compile Include="IMessageLite.cs" />
     <Compile Include="InvalidProtocolBufferException.cs" />
     <Compile Include="IRpcChannel.cs" />
     <Compile Include="IRpcController.cs" />

src/ProtocolBuffers/ProtocolBuffersLite.csproj

@@ -0,0 +1,115 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{6969BDCE-D925-43F3-94AC-A531E6DF2591}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.ProtocolBuffers</RootNamespace>
+    <AssemblyName>Google.ProtocolBuffersLite</AssemblyName>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>Properties\Google.ProtocolBuffers.snk</AssemblyOriginatorKeyFile>
+    <FileUpgradeFlags>
+    </FileUpgradeFlags>
+    <OldToolsVersion>3.5</OldToolsVersion>
+    <UpgradeBackupLocation />
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>TRACE;DEBUG;LITE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE;LITE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+  </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;LITE</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;LITE</DefineConstants>
+	  <ErrorReport>prompt</ErrorReport>
+	  <WarningLevel>4</WarningLevel>
+	  <NoStdLib>true</NoStdLib>
+	  <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="mscorlib" />
+    <Reference Include="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="Properties\Google.ProtocolBuffers.snk" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="AbstractBuilderLite.cs" />
+    <Compile Include="AbstractMessageLite.cs" />
+    <Compile Include="Collections\Dictionaries.cs" />
+    <Compile Include="Collections\Enumerables.cs" />
+    <Compile Include="Collections\IPopsicleList.cs" />
+    <Compile Include="Collections\Lists.cs" />
+    <Compile Include="Collections\PopsicleList.cs" />
+    <Compile Include="Collections\ReadOnlyDictionary.cs" />
+    <Compile Include="Descriptors\FieldMappingAttribute.cs" />
+    <Compile Include="Descriptors\FieldType.cs" />
+    <Compile Include="Descriptors\MappedType.cs" />
+    <Compile Include="EnumLite.cs" />
+    <Compile Include="ExtendableBuilderLite.cs" />
+    <Compile Include="ExtendableMessageLite.cs" />
+    <Compile Include="FieldSet.cs" />
+    <Compile Include="GeneratedBuilderLite.cs" />
+    <Compile Include="GeneratedExtensionLite.cs" />
+    <Compile Include="GeneratedMessageLite.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="ByteString.cs" />
+    <Compile Include="CodedInputStream.cs" />
+    <Compile Include="CodedOutputStream.cs" />
+    <Compile Include="ExtensionRegistryLite.cs" />
+    <Compile Include="IBuilderLite.cs" />
+    <Compile Include="IMessageLite.cs">
+      <SubType>Code</SubType>
+    </Compile>
+    <Compile Include="InvalidProtocolBufferException.cs" />
+    <Compile Include="ThrowHelper.cs" />
+    <Compile Include="UninitializedMessageException.cs" />
+    <Compile Include="WireFormat.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" Condition=" '$(Configuration)' != 'Silverlight2' " />
+  <Import Project="$(MSBuildExtensionsPath)\Microsoft\Silverlight\v2.0\Microsoft.Silverlight.CSharp.targets" Condition=" '$(Configuration)' == 'Silverlight2' " />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

src/ProtocolBuffers/SortedList.cs

@@ -50,6 +50,18 @@ namespace Google.ProtocolBuffers
     {
         private readonly IDictionary<TKey, TValue> wrapped = new Dictionary<TKey, TValue>();
 
+        public SortedList()
+        {
+        }
+
+        public SortedList(IDictionary<TKey, TValue> dictionary)
+        {
+            foreach (KeyValuePair<TKey, TValue> entry in dictionary)
+            {
+                Add(entry.Key, entry.Value);
+            }
+        }
+
         public void Add(TKey key, TValue value)
         {
             wrapped.Add(key, value);

src/ProtocolBuffers/TextFormat.cs

@@ -170,13 +170,19 @@ namespace Google.ProtocolBuffers {
         }
 
         case FieldType.Enum: {
-          generator.Print(((EnumValueDescriptor) value).Name);
+          if (value is IEnumLite && !(value is EnumValueDescriptor)) {
+            throw new NotSupportedException("Lite enumerations are not supported.");
+          }
+          generator.Print(((EnumValueDescriptor)value).Name);
           break;
         }
 
         case FieldType.Message:
         case FieldType.Group:
-          Print((IMessage) value, generator);
+          if (value is IMessageLite && !(value is IMessage)) {
+            throw new NotSupportedException("Lite messages are not supported.");
+          }
+          Print((IMessage)value, generator);
           break;
       }
     }
@@ -576,7 +582,9 @@ namespace Google.ProtocolBuffers {
         if (extension == null) {
           subBuilder = builder.CreateBuilderForField(field);
         } else {
-          subBuilder = extension.DefaultInstance.WeakCreateBuilderForType();
+          subBuilder = extension.DefaultInstance.WeakCreateBuilderForType() as IBuilder;
+          if (subBuilder == null)
+            throw new NotSupportedException("Lite messages are not supported.");
         }
 
         while (!tokenizer.TryConsume(endToken)) {

src/ProtocolBuffers/UninitializedMessageException.cs

@@ -36,8 +36,10 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Text;
+#if !LITE
 using Google.ProtocolBuffers.Collections;
 using Google.ProtocolBuffers.Descriptors;
+#endif
 
 namespace Google.ProtocolBuffers {
   /// <summary>
@@ -47,16 +49,10 @@ namespace Google.ProtocolBuffers {
 
     private readonly IList<string> missingFields;
 
-    public UninitializedMessageException(IMessage message)
-        : this(FindMissingFields(message)) {
-    }
-
     private UninitializedMessageException(IList<string> missingFields)
         : base(BuildDescription(missingFields)) {
-      this.missingFields = Lists.AsReadOnly(missingFields);
+      this.missingFields = new List<string>(missingFields);
     }
-
-    
     /// <summary>
     /// Returns a read-only list of human-readable names of
     /// required fields missing from this message. Each name
@@ -92,6 +88,19 @@ namespace Google.ProtocolBuffers {
       return description.ToString();
     }
 
+    /// <summary>
+    /// For Lite exceptions that do not known how to enumerate missing fields
+    /// </summary>
+    public UninitializedMessageException(IMessageLite message)
+      : base(String.Format("Message {0} is missing required fields", message.GetType())) {
+      missingFields = new List<string>();
+    }
+
+#if !LITE
+    public UninitializedMessageException(IMessage message)
+        : this(FindMissingFields(message)) {
+    }
+
     /// <summary>
     /// Returns a list of the full "paths" of missing required
     /// fields in the specified message.
@@ -120,11 +129,19 @@ namespace Google.ProtocolBuffers {
           if (field.IsRepeated) {
             int i = 0;
             foreach (object element in (IEnumerable) value) {
-              FindMissingFields((IMessage) element, SubMessagePrefix(prefix, field, i++), results);
+              if (element is IMessage) {
+                FindMissingFields((IMessage)element, SubMessagePrefix(prefix, field, i++), results);
+              } else {
+                results.Add(prefix + field.Name);
+              }
             }
           } else {
             if (message.HasField(field)) {
-              FindMissingFields((IMessage) value, SubMessagePrefix(prefix, field, -1), results);
+              if (value is IMessage) {
+                FindMissingFields((IMessage)value, SubMessagePrefix(prefix, field, -1), results);
+              } else {
+                results.Add(prefix + field.Name);
+              }
             }
           }
         }
@@ -148,5 +165,6 @@ namespace Google.ProtocolBuffers {
       result.Append('.');
       return result.ToString();
     }
+#endif
   }
 }

src/ProtocolBuffers/UnknownField.cs

@@ -172,7 +172,9 @@ namespace Google.ProtocolBuffers {
         output.WriteBytes(fieldNumber, value);
       }
       foreach (UnknownFieldSet value in groupList) {
+#pragma warning disable 0612
         output.WriteUnknownGroup(fieldNumber, value);
+#pragma warning restore 0612
       }
     }
 
@@ -195,7 +197,9 @@ namespace Google.ProtocolBuffers {
         result += CodedOutputStream.ComputeBytesSize(fieldNumber, value);
       }
       foreach (UnknownFieldSet value in groupList) {
+#pragma warning disable 0612
         result += CodedOutputStream.ComputeUnknownGroupSize(fieldNumber, value);
+#pragma warning restore 0612
       }
       return result;
     }

src/ProtocolBuffers/UnknownFieldSet.cs

@@ -51,7 +51,7 @@ namespace Google.ProtocolBuffers {
   /// 
   /// Most users will never need to use this class directly.
   /// </summary>
-  public sealed class UnknownFieldSet {
+  public sealed class UnknownFieldSet : IMessageLite {
 
     private static readonly UnknownFieldSet defaultInstance = new UnknownFieldSet(new Dictionary<int, UnknownField>());
 
@@ -138,6 +138,14 @@ namespace Google.ProtocolBuffers {
       return TextFormat.PrintToString(this);
     }
 
+    /// <summary>
+    /// Converts the set to a string in protocol buffer text format. This
+    /// is just a trivial wrapper around TextFormat.PrintToString.
+    /// </summary>
+    public void PrintTo(TextWriter writer) {
+      TextFormat.Print(this, writer);
+    }
+
     /// <summary>
     /// Serializes the message to a ByteString and returns it. This is
     /// just a trivial wrapper around WriteTo(CodedOutputStream).
@@ -237,16 +245,43 @@ namespace Google.ProtocolBuffers {
       return CreateBuilder().MergeFrom(input).Build();
     }
 
+    #region IMessageLite Members
+
+    public bool IsInitialized {
+      get { return fields != null; }
+    }
+
+    public void WriteDelimitedTo(Stream output) {
+      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
+      codedOutput.WriteRawVarint32((uint) SerializedSize);
+      WriteTo(codedOutput);
+      codedOutput.Flush();
+    }
+
+    public IBuilderLite WeakCreateBuilderForType() {
+      return new Builder();
+    }
+
+    public IBuilderLite WeakToBuilder() {
+      return new Builder(fields);
+    }
+
+    public IMessageLite WeakDefaultInstanceForType {
+      get { return defaultInstance; }
+    }
+
+    #endregion
+
     /// <summary>
     /// Builder for UnknownFieldSets.
     /// </summary>
-    public sealed class Builder
+    public sealed class Builder : IBuilderLite
     {
       /// <summary>
       /// Mapping from number to field. Note that by using a SortedList we ensure
       /// that the fields will be serialized in ascending order.
       /// </summary>
-      private IDictionary<int, UnknownField> fields = new SortedList<int, UnknownField>();
+      private IDictionary<int, UnknownField> fields;
       // Optimization:  We keep around a builder for the last field that was
       // modified so that we can efficiently add to it multiple times in a
       // row (important when parsing an unknown repeated field).
@@ -254,6 +289,11 @@ namespace Google.ProtocolBuffers {
       private UnknownField.Builder lastField;
 
       internal Builder() {
+        fields = new SortedList<int, UnknownField>();
+      }
+
+      internal Builder(IDictionary<int, UnknownField> dictionary) {
+        fields = new SortedList<int, UnknownField>(dictionary); 
       }
 
       /// <summary>
@@ -356,7 +396,9 @@ namespace Google.ProtocolBuffers {
             return true;
           case WireFormat.WireType.StartGroup: {
             Builder subBuilder = CreateBuilder();
+#pragma warning disable 0612
             input.ReadUnknownGroup(number, subBuilder);
+#pragma warning restore 0612
             GetFieldBuilder(number).AddGroup(subBuilder.Build());
             return true;
           }
@@ -469,6 +511,7 @@ namespace Google.ProtocolBuffers {
           if (tag == 0) {
             break;
           }
+
           if (!MergeFieldFrom(input, extensionRegistry, builder, tag)) {
             // end group tag
             break;
@@ -485,7 +528,7 @@ namespace Google.ProtocolBuffers {
       /// <param name="builder">Builder to merge field into, if it's a known field</param>
       /// <param name="tag">The tag, which should already have been read from the input</param>
       /// <returns>true unless the tag is an end-group tag</returns>
-      internal bool MergeFieldFrom(CodedInputStream input, 
+      internal bool MergeFieldFrom(CodedInputStream input,
           ExtensionRegistry extensionRegistry, IBuilder builder, uint tag) {
 
         MessageDescriptor type = builder.DescriptorForType;
@@ -498,7 +541,7 @@ namespace Google.ProtocolBuffers {
         int fieldNumber = WireFormat.GetTagFieldNumber(tag);
 
         FieldDescriptor field;
-        IMessage defaultFieldInstance = null;
+        IMessageLite defaultFieldInstance = null;
 
         if (type.IsExtensionNumber(fieldNumber)) {
           ExtensionInfo extension = extensionRegistry[type, fieldNumber];
@@ -543,14 +586,14 @@ namespace Google.ProtocolBuffers {
           switch (field.FieldType) {
             case FieldType.Group:
             case FieldType.Message: {
-                IBuilder subBuilder;
+                IBuilderLite subBuilder;
                 if (defaultFieldInstance != null) {
                   subBuilder = defaultFieldInstance.WeakCreateBuilderForType();
                 } else {
                   subBuilder = builder.CreateBuilderForField(field);
                 }
                 if (!field.IsRepeated) {
-                  subBuilder.WeakMergeFrom((IMessage)builder[field]);
+                  subBuilder.WeakMergeFrom((IMessageLite)builder[field]);
                 }
                 if (field.FieldType == FieldType.Group) {
                   input.ReadGroup(field.FieldNumber, subBuilder, extensionRegistry);
@@ -609,7 +652,7 @@ namespace Google.ProtocolBuffers {
 
         int typeId = 0;
         ByteString rawBytes = null;  // If we encounter "message" before "typeId"
-        IBuilder subBuilder = null;
+        IBuilderLite subBuilder = null;
         FieldDescriptor field = null;
 
         while (true) {
@@ -626,7 +669,7 @@ namespace Google.ProtocolBuffers {
               if (extension != null) {
                 field = extension.Descriptor;
                 subBuilder = extension.DefaultInstance.WeakCreateBuilderForType();
-                IMessage originalMessage = (IMessage)builder[field];
+                IMessageLite originalMessage = (IMessageLite)builder[field];
                 if (originalMessage != null) {
                   subBuilder.WeakMergeFrom(originalMessage);
                 }
@@ -672,6 +715,54 @@ namespace Google.ProtocolBuffers {
           builder[field] = subBuilder.WeakBuild();
         }
       }
+
+      #region IBuilderLite Members
+
+      bool IBuilderLite.IsInitialized {
+        get { return fields != null; }
+      }
+
+      IBuilderLite IBuilderLite.WeakClear() {
+        return Clear();
+      }
+
+      IBuilderLite IBuilderLite.WeakMergeFrom(IMessageLite message) {
+        return MergeFrom((UnknownFieldSet)message);
+      }
+
+      IBuilderLite IBuilderLite.WeakMergeFrom(ByteString data) {
+        return MergeFrom(data);
+      }
+
+      IBuilderLite IBuilderLite.WeakMergeFrom(ByteString data, ExtensionRegistry registry) {
+        return MergeFrom(data);
+      }
+
+      IBuilderLite IBuilderLite.WeakMergeFrom(CodedInputStream input) {
+        return MergeFrom(input);
+      }
+
+      IBuilderLite IBuilderLite.WeakMergeFrom(CodedInputStream input, ExtensionRegistry registry) {
+        return MergeFrom(input);
+      }
+
+      IMessageLite IBuilderLite.WeakBuild() {
+        return Build();
+      }
+
+      IMessageLite IBuilderLite.WeakBuildPartial() {
+        return Build();
+      }
+
+      IBuilderLite IBuilderLite.WeakClone() {
+        return Build().WeakToBuilder();
+      }
+
+      IMessageLite IBuilderLite.WeakDefaultInstanceForType {
+        get { return DefaultInstance; }
+      }
+
+      #endregion
     }
   }
 }

src/ProtocolBuffers/WireFormat.cs

@@ -33,7 +33,9 @@
 #endregion
 
 using System;
+#if !LITE
 using Google.ProtocolBuffers.Descriptors;
+#endif
 
 namespace Google.ProtocolBuffers {
   
@@ -115,6 +117,7 @@ namespace Google.ProtocolBuffers {
       return (uint) (fieldNumber << TagTypeBits) | (uint) wireType;
     }
 
+#if !LITE
     [CLSCompliant(false)]
     public static uint MakeTag(FieldDescriptor field) {
       return MakeTag(field.FieldNumber, GetWireType(field));
@@ -170,5 +173,6 @@ namespace Google.ProtocolBuffers {
           throw new ArgumentOutOfRangeException("No such field type");
       }
     }
+#endif
   }
 }

src/ProtocolBuffersLite.Test/AbstractBuilderLiteTest.cs

@@ -0,0 +1,268 @@
+#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.IO;
+using Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class AbstractBuilderLiteTest {
+
+    [Test]
+    public void TestMergeFromCodedInputStream() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalUint32(uint.MaxValue).Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      using (MemoryStream ms = new MemoryStream(msg.ToByteArray())) {
+        CodedInputStream ci = CodedInputStream.CreateInstance(ms);
+        copy = copy.ToBuilder().MergeFrom(ci).Build();
+      }
+
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakClear() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.DefaultInstance;
+
+      copy = msg.ToBuilder().SetOptionalString("Should be removed.").Build();
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      copy = (TestAllTypesLite)((IBuilderLite)copy.ToBuilder()).WeakClear().WeakBuild();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestBuilderLiteMergeFromCodedInputStream() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalString("Should be merged.").Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      copy = copy.ToBuilder().MergeFrom(CodedInputStream.CreateInstance(new MemoryStream(msg.ToByteArray()))).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestBuilderLiteMergeDelimitedFrom() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalString("Should be merged.").Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+      Stream s = new MemoryStream();
+      msg.WriteDelimitedTo(s);
+      s.Position = 0;
+      copy = copy.ToBuilder().MergeDelimitedFrom(s).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestBuilderLiteMergeDelimitedFromExtensions() {
+      TestAllExtensionsLite copy, msg = TestAllExtensionsLite.CreateBuilder()
+        .SetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite, "Should be merged.").Build();
+
+      copy = TestAllExtensionsLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      Stream s = new MemoryStream();
+      msg.WriteDelimitedTo(s);
+      s.Position = 0;
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      copy = copy.ToBuilder().MergeDelimitedFrom(s, registry).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+      Assert.AreEqual("Should be merged.", copy.GetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite));
+    }
+
+    [Test]
+    public void TestBuilderLiteMergeFromStream() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalString("Should be merged.").Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+      Stream s = new MemoryStream();
+      msg.WriteTo(s);
+      s.Position = 0;
+      copy = copy.ToBuilder().MergeFrom(s).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestBuilderLiteMergeFromStreamExtensions() {
+      TestAllExtensionsLite copy, msg = TestAllExtensionsLite.CreateBuilder()
+        .SetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite, "Should be merged.").Build();
+
+      copy = TestAllExtensionsLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      Stream s = new MemoryStream();
+      msg.WriteTo(s);
+      s.Position = 0;
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      copy = copy.ToBuilder().MergeFrom(s, registry).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+      Assert.AreEqual("Should be merged.", copy.GetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite));
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakMergeFromIMessageLite() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalString("Should be merged.").Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      copy = (TestAllTypesLite)((IBuilderLite)copy.ToBuilder()).WeakMergeFrom((IMessageLite)msg).WeakBuild();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakMergeFromByteString() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalString("Should be merged.").Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      copy = (TestAllTypesLite)((IBuilderLite)copy.ToBuilder()).WeakMergeFrom(msg.ToByteString()).WeakBuild();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakMergeFromByteStringExtensions() {
+      TestAllExtensionsLite copy, msg = TestAllExtensionsLite.CreateBuilder()
+        .SetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite, "Should be merged.").Build();
+
+      copy = TestAllExtensionsLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      copy = (TestAllExtensionsLite)((IBuilderLite)copy.ToBuilder()).WeakMergeFrom(msg.ToByteString(), ExtensionRegistry.Empty).WeakBuild();
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      copy = (TestAllExtensionsLite)((IBuilderLite)copy.ToBuilder()).WeakMergeFrom(msg.ToByteString(), registry).WeakBuild();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+      Assert.AreEqual("Should be merged.", copy.GetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite));
+    }
+    
+    [Test]
+    public void TestIBuilderLiteWeakMergeFromCodedInputStream() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalUint32(uint.MaxValue).Build();
+
+      copy = TestAllTypesLite.DefaultInstance;
+      Assert.AreNotEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      using (MemoryStream ms = new MemoryStream(msg.ToByteArray())) {
+        CodedInputStream ci = CodedInputStream.CreateInstance(ms);
+        copy = (TestAllTypesLite)((IBuilderLite)copy.ToBuilder()).WeakMergeFrom(ci).WeakBuild();
+      }
+
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakBuildPartial() {
+      IBuilderLite builder = TestRequiredLite.CreateBuilder();
+      Assert.IsFalse(builder.IsInitialized);
+
+      IMessageLite msg = builder.WeakBuildPartial();
+      Assert.IsFalse(msg.IsInitialized);
+
+      Assert.AreEqual(msg.ToByteArray(), TestRequiredLite.DefaultInstance.ToByteArray());
+    }
+
+    [Test, ExpectedException(typeof(UninitializedMessageException ))]
+    public void TestIBuilderLiteWeakBuildUninitialized() {
+      IBuilderLite builder = TestRequiredLite.CreateBuilder();
+      Assert.IsFalse(builder.IsInitialized);
+      builder.WeakBuild();
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakBuild() {
+      IBuilderLite builder = TestRequiredLite.CreateBuilder()
+        .SetD(0)
+        .SetEn(ExtraEnum.EXLITE_BAZ);
+      Assert.IsTrue(builder.IsInitialized);
+      builder.WeakBuild();
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakClone() {
+      TestRequiredLite msg = TestRequiredLite.CreateBuilder()
+        .SetD(1).SetEn(ExtraEnum.EXLITE_BAR).Build();
+      Assert.IsTrue(msg.IsInitialized);
+
+      IMessageLite copy = ((IBuilderLite)msg.ToBuilder()).WeakClone().WeakBuild();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestIBuilderLiteWeakDefaultInstance() {
+      Assert.IsTrue(ReferenceEquals(TestRequiredLite.DefaultInstance,
+        ((IBuilderLite)TestRequiredLite.CreateBuilder()).WeakDefaultInstanceForType));
+    }
+
+    [Test]
+    public void TestGeneratedBuilderLiteAddRange() {
+      TestAllTypesLite copy, msg = TestAllTypesLite.CreateBuilder()
+        .SetOptionalUint32(123)
+        .AddRepeatedInt32(1)
+        .AddRepeatedInt32(2)
+        .AddRepeatedInt32(3)
+        .Build();
+
+      copy = msg.DefaultInstanceForType.ToBuilder().MergeFrom(msg).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+  }
+}

src/ProtocolBuffersLite.Test/AbstractMessageLiteTest.cs

@@ -0,0 +1,126 @@
+#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.IO;
+using Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class AbstractMessageLiteTest {
+
+    [Test]
+    public void TestMessageLiteToByteString() {
+      TestRequiredLite msg = TestRequiredLite.CreateBuilder()
+        .SetD(42)
+        .SetEn(ExtraEnum.EXLITE_BAZ)
+        .Build();
+      
+      ByteString b = msg.ToByteString();
+      Assert.AreEqual(4, b.Length);
+      Assert.AreEqual(TestRequiredLite.DFieldNumber << 3, b[0]);
+      Assert.AreEqual(42, b[1]);
+      Assert.AreEqual(TestRequiredLite.EnFieldNumber << 3, b[2]);
+      Assert.AreEqual((int)ExtraEnum.EXLITE_BAZ, b[3]);
+    }
+
+    [Test]
+    public void TestMessageLiteToByteArray() {
+      TestRequiredLite msg = TestRequiredLite.CreateBuilder()
+        .SetD(42)
+        .SetEn(ExtraEnum.EXLITE_BAZ)
+        .Build();
+
+      ByteString b = msg.ToByteString();
+      ByteString copy = ByteString.CopyFrom(msg.ToByteArray());
+      Assert.AreEqual(b, copy);
+    }
+
+    [Test]
+    public void TestMessageLiteWriteTo() {
+      TestRequiredLite msg = TestRequiredLite.CreateBuilder()
+        .SetD(42)
+        .SetEn(ExtraEnum.EXLITE_BAZ)
+        .Build();
+
+      MemoryStream ms = new MemoryStream();
+      msg.WriteTo(ms);
+      Assert.AreEqual(msg.ToByteArray(), ms.ToArray());
+    }
+
+    [Test]
+    public void TestMessageLiteWriteDelimitedTo() {
+      TestRequiredLite msg = TestRequiredLite.CreateBuilder()
+        .SetD(42)
+        .SetEn(ExtraEnum.EXLITE_BAZ)
+        .Build();
+
+      MemoryStream ms = new MemoryStream();
+      msg.WriteDelimitedTo(ms);
+      byte[] buffer = ms.ToArray();
+
+      Assert.AreEqual(5, buffer.Length);
+      Assert.AreEqual(4, buffer[0]);
+      byte[] msgBytes = new byte[4];
+      Array.Copy(buffer, 1, msgBytes, 0, 4);
+      Assert.AreEqual(msg.ToByteArray(), msgBytes);
+    }
+
+    [Test]
+    public void TestIMessageLiteWeakCreateBuilderForType() {
+      IMessageLite msg = TestRequiredLite.DefaultInstance;
+      Assert.AreEqual(typeof(TestRequiredLite.Builder), msg.WeakCreateBuilderForType().GetType());
+    }
+
+    [Test]
+    public void TestMessageLiteWeakToBuilder() {
+      IMessageLite msg = TestRequiredLite.CreateBuilder()
+        .SetD(42)
+        .SetEn(ExtraEnum.EXLITE_BAZ)
+        .Build();
+
+      IMessageLite copy = msg.WeakToBuilder().WeakBuild();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestMessageLiteWeakDefaultInstanceForType() {
+      IMessageLite msg = TestRequiredLite.DefaultInstance;
+      Assert.IsTrue(Object.ReferenceEquals(TestRequiredLite.DefaultInstance, msg.WeakDefaultInstanceForType));
+    }
+  }
+}

src/ProtocolBuffersLite.Test/ExtendableBuilderLiteTest.cs

@@ -0,0 +1,267 @@
+#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 Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class ExtendableBuilderLiteTest {
+
+    [Test]
+    public void TestHasExtensionT() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+          .SetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite, 123);
+
+      Assert.IsTrue(builder.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestHasExtensionTMissing() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      Assert.IsFalse(builder.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestGetExtensionCountT() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 1)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 2)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 3);
+
+      Assert.AreEqual(3, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestGetExtensionCountTEmpty() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      Assert.AreEqual(0, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestGetExtensionTNull() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      string value = builder.GetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite);
+      Assert.IsNull(value);
+    }
+
+    [Test]
+    public void TestGetExtensionTValue() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+          .SetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite, 3);
+
+      Assert.AreEqual(3, builder.GetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestGetExtensionTEmpty() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      Assert.AreEqual(0, builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite).Count);
+    }
+
+    [Test]
+    public void TestGetExtensionTList() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 1)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 2)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 3);
+
+      IList<int> values = builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite);
+      Assert.AreEqual(3, values.Count);
+    }
+
+    [Test]
+    public void TestGetExtensionTIndex() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 1)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 2);
+
+      for(int i = 0; i < 3; i++ )
+        Assert.AreEqual(i, builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, i));
+    }
+
+    [Test,ExpectedException(typeof(ArgumentOutOfRangeException))]
+    public void TestGetExtensionTIndexOutOfRange() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0);
+    }
+
+    [Test]
+    public void TestSetExtensionTIndex() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 1)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 2);
+
+      for (int i = 0; i < 3; i++)
+        Assert.AreEqual(i, builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, i));
+
+      builder.SetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0, 5);
+      builder.SetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 1, 6);
+      builder.SetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 2, 7);
+
+      for (int i = 0; i < 3; i++)
+        Assert.AreEqual(5 + i, builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, i));
+    }
+
+    [Test, ExpectedException(typeof(ArgumentOutOfRangeException))]
+    public void TestSetExtensionTIndexOutOfRange() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      builder.SetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0, -1);
+    }
+
+    [Test]
+    public void TestClearExtensionTList() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0);
+      Assert.AreEqual(1, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+      
+      builder.ClearExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite);
+      Assert.AreEqual(0, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestClearExtensionTValue() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .SetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite, 0);
+      Assert.IsTrue(builder.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+
+      builder.ClearExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite);
+      Assert.IsFalse(builder.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestIndexedByDescriptor() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      Assert.IsFalse(builder.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+      
+      builder[UnitTestLiteProtoFile.OptionalInt32ExtensionLite.Descriptor] = 123;
+      
+      Assert.IsTrue(builder.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+      Assert.AreEqual(123, builder.GetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestIndexedByDescriptorAndOrdinal() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0);
+      Assert.AreEqual(1, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+
+      IFieldDescriptorLite f = UnitTestLiteProtoFile.RepeatedInt32ExtensionLite.Descriptor;
+      builder[f, 0] = 123;
+
+      Assert.AreEqual(1, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+      Assert.AreEqual(123, builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0));
+    }
+
+    [Test, ExpectedException(typeof(ArgumentOutOfRangeException))]
+    public void TestIndexedByDescriptorAndOrdinalOutOfRange() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+      Assert.AreEqual(0, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+
+      IFieldDescriptorLite f = UnitTestLiteProtoFile.RepeatedInt32ExtensionLite.Descriptor;
+      builder[f, 0] = 123;
+    }
+
+    [Test]
+    public void TestClearFieldByDescriptor() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0);
+      Assert.AreEqual(1, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+
+      IFieldDescriptorLite f = UnitTestLiteProtoFile.RepeatedInt32ExtensionLite.Descriptor;
+      builder.ClearField(f);
+      Assert.AreEqual(0, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+    }
+
+    [Test]
+    public void TestAddRepeatedFieldByDescriptor() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0);
+      Assert.AreEqual(1, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+
+      IFieldDescriptorLite f = UnitTestLiteProtoFile.RepeatedInt32ExtensionLite.Descriptor;
+      builder.AddRepeatedField(f, 123);
+      Assert.AreEqual(2, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
+      Assert.AreEqual(123, builder.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 1));
+    }
+
+    [Test]
+    public void TestMissingExtensionsLite()
+    {
+        const int optionalInt32 = 12345678;
+        TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder();
+        builder.SetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite, optionalInt32);
+        builder.AddExtension(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite, 1.1);
+        builder.AddExtension(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite, 1.2);
+        builder.AddExtension(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite, 1.3);
+        TestAllExtensionsLite msg = builder.Build();
+
+        Assert.IsTrue(msg.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+        Assert.AreEqual(3, msg.GetExtensionCount(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite));
+
+        byte[] bits = msg.ToByteArray();
+        TestAllExtensionsLite copy = TestAllExtensionsLite.ParseFrom(bits);
+        Assert.IsFalse(copy.HasExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+        Assert.AreEqual(0, copy.GetExtensionCount(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite));
+        Assert.AreNotEqual(msg, copy);
+
+        //The lite runtime removes all unknown fields and extensions
+        byte[] copybits = copy.ToByteArray();
+        Assert.AreEqual(0, copybits.Length);
+    }
+
+    [Test]
+    public void TestMissingFieldsLite()
+    {
+        TestAllTypesLite msg = TestAllTypesLite.CreateBuilder()
+            .SetOptionalInt32(123)
+            .SetOptionalString("123")
+            .Build();
+
+        byte[] bits = msg.ToByteArray();
+        TestAllExtensionsLite copy = TestAllExtensionsLite.ParseFrom(bits);
+        Assert.AreNotEqual(msg, copy);
+
+        //The lite runtime removes all unknown fields and extensions
+        byte[] copybits = copy.ToByteArray();
+        Assert.AreEqual(0, copybits.Length);
+    }
+  }
+}

src/ProtocolBuffersLite.Test/ExtendableMessageLiteTest.cs

@@ -0,0 +1,304 @@
+#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.Text;
+using Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class ExtendableMessageLiteTest {
+
+    [Test, Ignore("Not implemented, no assertion made"), ExpectedException(typeof(ArgumentException))]
+    public void ExtensionWriterInvalidExtension() {
+      TestPackedExtensionsLite.CreateBuilder()[UnitTestLiteProtoFile.OptionalForeignMessageExtensionLite.Descriptor] = 
+        ForeignMessageLite.DefaultInstance;
+    }
+
+    [Test]
+    public void ExtensionWriterTestMessages() {
+      TestAllExtensionsLite.Builder b = TestAllExtensionsLite.CreateBuilder().SetExtension(
+        UnitTestLiteProtoFile.OptionalForeignMessageExtensionLite, ForeignMessageLite.CreateBuilder().SetC(123).Build());
+      TestAllExtensionsLite copy, msg = b.Build();
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      copy = TestAllExtensionsLite.ParseFrom(msg.ToByteArray(), registry);
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void ExtensionWriterIsInitialized() {
+      Assert.IsTrue(ForeignMessageLite.DefaultInstance.IsInitialized);
+      Assert.IsTrue(TestPackedExtensionsLite.CreateBuilder().IsInitialized);
+      Assert.IsTrue(TestAllExtensionsLite.CreateBuilder().SetExtension(
+        UnitTestLiteProtoFile.OptionalForeignMessageExtensionLite, ForeignMessageLite.DefaultInstance)
+        .IsInitialized);
+    }
+
+    [Test]
+    public void ExtensionWriterTestSetExtensionLists() {
+      TestAllExtensionsLite msg, copy;
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .SetExtension(UnitTestLiteProtoFile.RepeatedBoolExtensionLite, new[] { true, false })
+        .SetExtension(UnitTestLiteProtoFile.RepeatedCordExtensionLite, new[] { "123", "456" })
+        .SetExtension(UnitTestLiteProtoFile.RepeatedForeignEnumExtensionLite, new[] { ForeignEnumLite.FOREIGN_LITE_BAZ, ForeignEnumLite.FOREIGN_LITE_FOO })
+        ;
+
+      msg = builder.Build();
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      copy = TestAllExtensionsLite.ParseFrom(msg.ToByteArray(), registry);
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      Assert.AreEqual(ForeignEnumLite.FOREIGN_LITE_FOO, copy.GetExtension(UnitTestLiteProtoFile.RepeatedForeignEnumExtensionLite, 1));
+    }
+
+    [Test]
+    public void ExtensionWriterTest() {
+      TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
+        .SetExtension(UnitTestLiteProtoFile.DefaultBoolExtensionLite, true)
+        .SetExtension(UnitTestLiteProtoFile.DefaultBytesExtensionLite, ByteString.CopyFromUtf8("123"))
+        .SetExtension(UnitTestLiteProtoFile.DefaultCordExtensionLite, "123")
+        .SetExtension(UnitTestLiteProtoFile.DefaultDoubleExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultFixed32ExtensionLite, 123u)
+        .SetExtension(UnitTestLiteProtoFile.DefaultFixed64ExtensionLite, 123u)
+        .SetExtension(UnitTestLiteProtoFile.DefaultFloatExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ)
+        .SetExtension(UnitTestLiteProtoFile.DefaultImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ)
+        .SetExtension(UnitTestLiteProtoFile.DefaultInt32ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultInt64ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultNestedEnumExtensionLite, TestAllTypesLite.Types.NestedEnum.FOO)
+        .SetExtension(UnitTestLiteProtoFile.DefaultSfixed32ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultSfixed64ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultSint32ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultSint64ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.DefaultStringExtensionLite, "123")
+        .SetExtension(UnitTestLiteProtoFile.DefaultStringPieceExtensionLite, "123")
+        .SetExtension(UnitTestLiteProtoFile.DefaultUint32ExtensionLite, 123u)
+        .SetExtension(UnitTestLiteProtoFile.DefaultUint64ExtensionLite, 123u)
+        //Optional
+        .SetExtension(UnitTestLiteProtoFile.OptionalBoolExtensionLite, true)
+        .SetExtension(UnitTestLiteProtoFile.OptionalBytesExtensionLite, ByteString.CopyFromUtf8("123"))
+        .SetExtension(UnitTestLiteProtoFile.OptionalCordExtensionLite, "123")
+        .SetExtension(UnitTestLiteProtoFile.OptionalDoubleExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalFixed32ExtensionLite, 123u)
+        .SetExtension(UnitTestLiteProtoFile.OptionalFixed64ExtensionLite, 123u)
+        .SetExtension(UnitTestLiteProtoFile.OptionalFloatExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ)
+        .SetExtension(UnitTestLiteProtoFile.OptionalImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ)
+        .SetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalInt64ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalNestedEnumExtensionLite, TestAllTypesLite.Types.NestedEnum.FOO)
+        .SetExtension(UnitTestLiteProtoFile.OptionalSfixed32ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalSfixed64ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalSint32ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalSint64ExtensionLite, 123)
+        .SetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite, "123")
+        .SetExtension(UnitTestLiteProtoFile.OptionalStringPieceExtensionLite, "123")
+        .SetExtension(UnitTestLiteProtoFile.OptionalUint32ExtensionLite, 123u)
+        .SetExtension(UnitTestLiteProtoFile.OptionalUint64ExtensionLite, 123u)
+        //Repeated
+        .AddExtension(UnitTestLiteProtoFile.RepeatedBoolExtensionLite, true)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedBytesExtensionLite, ByteString.CopyFromUtf8("123"))
+        .AddExtension(UnitTestLiteProtoFile.RepeatedCordExtensionLite, "123")
+        .AddExtension(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedFixed32ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedFixed64ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedFloatExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedInt64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedNestedEnumExtensionLite, TestAllTypesLite.Types.NestedEnum.FOO)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedSfixed32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedSfixed64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedSint32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedSint64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedStringExtensionLite, "123")
+        .AddExtension(UnitTestLiteProtoFile.RepeatedStringPieceExtensionLite, "123")
+        .AddExtension(UnitTestLiteProtoFile.RepeatedUint32ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.RepeatedUint64ExtensionLite, 123u)
+        ;
+      TestAllExtensionsLite msg = builder.Build();
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      TestAllExtensionsLite.Builder copyBuilder = TestAllExtensionsLite.CreateBuilder().MergeFrom(msg.ToByteArray(), registry);
+      TestAllExtensionsLite copy = copyBuilder.Build();
+
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestLiteProtoFile.DefaultBoolExtensionLite));
+      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestLiteProtoFile.DefaultBytesExtensionLite));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.DefaultCordExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultDoubleExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.DefaultFixed32ExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.DefaultFixed64ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultFloatExtensionLite));
+      Assert.AreEqual(ForeignEnumLite.FOREIGN_LITE_BAZ, copy.GetExtension(UnitTestLiteProtoFile.DefaultForeignEnumExtensionLite));
+      Assert.AreEqual(ImportEnumLite.IMPORT_LITE_BAZ, copy.GetExtension(UnitTestLiteProtoFile.DefaultImportEnumExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultInt32ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultInt64ExtensionLite));
+      Assert.AreEqual(TestAllTypesLite.Types.NestedEnum.FOO, copy.GetExtension(UnitTestLiteProtoFile.DefaultNestedEnumExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultSfixed32ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultSfixed64ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultSint32ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.DefaultSint64ExtensionLite));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.DefaultStringExtensionLite));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.DefaultStringPieceExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.DefaultUint32ExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.DefaultUint64ExtensionLite));
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestLiteProtoFile.OptionalBoolExtensionLite));
+      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestLiteProtoFile.OptionalBytesExtensionLite));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.OptionalCordExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalDoubleExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.OptionalFixed32ExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.OptionalFixed64ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalFloatExtensionLite));
+      Assert.AreEqual(ForeignEnumLite.FOREIGN_LITE_BAZ, copy.GetExtension(UnitTestLiteProtoFile.OptionalForeignEnumExtensionLite));
+      Assert.AreEqual(ImportEnumLite.IMPORT_LITE_BAZ, copy.GetExtension(UnitTestLiteProtoFile.OptionalImportEnumExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalInt64ExtensionLite));
+      Assert.AreEqual(TestAllTypesLite.Types.NestedEnum.FOO, copy.GetExtension(UnitTestLiteProtoFile.OptionalNestedEnumExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalSfixed32ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalSfixed64ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalSint32ExtensionLite));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.OptionalSint64ExtensionLite));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.OptionalStringPieceExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.OptionalUint32ExtensionLite));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.OptionalUint64ExtensionLite));
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestLiteProtoFile.RepeatedBoolExtensionLite, 0));
+      Assert.AreEqual(ByteString.CopyFromUtf8("123"), copy.GetExtension(UnitTestLiteProtoFile.RepeatedBytesExtensionLite, 0));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.RepeatedCordExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedDoubleExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.RepeatedFixed32ExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.RepeatedFixed64ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedFloatExtensionLite, 0));
+      Assert.AreEqual(ForeignEnumLite.FOREIGN_LITE_BAZ, copy.GetExtension(UnitTestLiteProtoFile.RepeatedForeignEnumExtensionLite, 0));
+      Assert.AreEqual(ImportEnumLite.IMPORT_LITE_BAZ, copy.GetExtension(UnitTestLiteProtoFile.RepeatedImportEnumExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedInt64ExtensionLite, 0));
+      Assert.AreEqual(TestAllTypesLite.Types.NestedEnum.FOO, copy.GetExtension(UnitTestLiteProtoFile.RepeatedNestedEnumExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedSfixed32ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedSfixed64ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedSint32ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.RepeatedSint64ExtensionLite, 0));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.RepeatedStringExtensionLite, 0));
+      Assert.AreEqual("123", copy.GetExtension(UnitTestLiteProtoFile.RepeatedStringPieceExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.RepeatedUint32ExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.RepeatedUint64ExtensionLite, 0));
+    }
+
+    [Test]
+    public void ExtensionWriterTestPacked() {
+
+      TestPackedExtensionsLite.Builder builder = TestPackedExtensionsLite.CreateBuilder()
+        .AddExtension(UnitTestLiteProtoFile.PackedBoolExtensionLite, true)
+        .AddExtension(UnitTestLiteProtoFile.PackedDoubleExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedFixed32ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedFixed64ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedFloatExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedInt32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedInt64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSfixed32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSfixed64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSint32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSint64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedUint32ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedUint64ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedBoolExtensionLite, true)
+        .AddExtension(UnitTestLiteProtoFile.PackedDoubleExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedFixed32ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedFixed64ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedFloatExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedInt32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedInt64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSfixed32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSfixed64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSint32ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedSint64ExtensionLite, 123)
+        .AddExtension(UnitTestLiteProtoFile.PackedUint32ExtensionLite, 123u)
+        .AddExtension(UnitTestLiteProtoFile.PackedUint64ExtensionLite, 123u);
+
+      TestPackedExtensionsLite msg = builder.Build();
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestLiteProtoFile.RegisterAllExtensions(registry);
+
+      TestPackedExtensionsLite.Builder copyBuilder = TestPackedExtensionsLite.CreateBuilder().MergeFrom(msg.ToByteArray(), registry);
+      TestPackedExtensionsLite copy = copyBuilder.Build();
+
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestLiteProtoFile.PackedBoolExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedDoubleExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedFixed32ExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedFixed64ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedFloatExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedInt32ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedInt64ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSfixed32ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSfixed64ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSint32ExtensionLite, 0));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSint64ExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedUint32ExtensionLite, 0));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedUint64ExtensionLite, 0));
+
+      Assert.AreEqual(true, copy.GetExtension(UnitTestLiteProtoFile.PackedBoolExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedDoubleExtensionLite, 1));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedFixed32ExtensionLite, 1));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedFixed64ExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedFloatExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedInt32ExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedInt64ExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSfixed32ExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSfixed64ExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSint32ExtensionLite, 1));
+      Assert.AreEqual(123, copy.GetExtension(UnitTestLiteProtoFile.PackedSint64ExtensionLite, 1));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedUint32ExtensionLite, 1));
+      Assert.AreEqual(123u, copy.GetExtension(UnitTestLiteProtoFile.PackedUint64ExtensionLite, 1));
+
+    }
+  }
+}

src/ProtocolBuffersLite.Test/InteropLiteTest.cs

@@ -0,0 +1,162 @@
+#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 Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class InteropLiteTest {
+
+    [Test]
+    public void TestConvertFromFullMinimal() {
+      TestInteropPerson person = TestInteropPerson.CreateBuilder()
+        .SetId(123)
+        .SetName("abc")
+        .Build();
+      Assert.IsTrue(person.IsInitialized);
+
+      TestInteropPersonLite copy = TestInteropPersonLite.ParseFrom(person.ToByteArray());
+
+      Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestConvertFromFullComplete() {
+      TestInteropPerson person = TestInteropPerson.CreateBuilder()
+        .SetId(123)
+        .SetName("abc")
+        .SetEmail("abc@123.com")
+        .AddRangeCodes(new[] { 1, 2, 3 })
+        .AddPhone(TestInteropPerson.Types.PhoneNumber.CreateBuilder().SetNumber("555-1234").Build())
+        .AddPhone(TestInteropPerson.Types.PhoneNumber.CreateBuilder().SetNumber("555-5678").Build())
+        .AddAddresses(TestInteropPerson.Types.Addresses.CreateBuilder().SetAddress("123 Seseme").SetCity("Wonderland").SetState("NA").SetZip(12345).Build())
+        .SetExtension(UnitTestExtrasFullProtoFile.EmployeeId, TestInteropEmployeeId.CreateBuilder().SetNumber("123").Build())
+        .Build();
+      Assert.IsTrue(person.IsInitialized);
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestExtrasLiteProtoFile.RegisterAllExtensions(registry);
+
+      TestInteropPersonLite copy = TestInteropPersonLite.ParseFrom(person.ToByteArray(), registry);
+
+      Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestConvertFromLiteMinimal() {
+      TestInteropPersonLite person = TestInteropPersonLite.CreateBuilder()
+        .SetId(123)
+        .SetName("abc")
+        .Build();
+      Assert.IsTrue(person.IsInitialized);
+
+      TestInteropPerson copy = TestInteropPerson.ParseFrom(person.ToByteArray());
+
+      Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestConvertFromLiteComplete() {
+      TestInteropPersonLite person = TestInteropPersonLite.CreateBuilder()
+        .SetId(123)
+        .SetName("abc")
+        .SetEmail("abc@123.com")
+        .AddRangeCodes(new[] { 1, 2, 3 })
+        .AddPhone(TestInteropPersonLite.Types.PhoneNumber.CreateBuilder().SetNumber("555-1234").Build())
+        .AddPhone(TestInteropPersonLite.Types.PhoneNumber.CreateBuilder().SetNumber("555-5678").Build())
+        .AddAddresses(TestInteropPersonLite.Types.Addresses.CreateBuilder().SetAddress("123 Seseme").SetCity("Wonderland").SetState("NA").SetZip(12345).Build())
+        .SetExtension(UnitTestExtrasLiteProtoFile.EmployeeIdLite, TestInteropEmployeeIdLite.CreateBuilder().SetNumber("123").Build())
+        .Build();
+      Assert.IsTrue(person.IsInitialized);
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestExtrasFullProtoFile.RegisterAllExtensions(registry);
+
+      TestInteropPerson copy = TestInteropPerson.ParseFrom(person.ToByteArray(), registry);
+
+      Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+    }
+
+    public ByteString AllBytes {
+      get {
+        byte[] bytes = new byte[256];
+        for (int i = 0; i < bytes.Length; i++)
+          bytes[i] = (byte)i;
+        return ByteString.CopyFrom(bytes);
+      }
+    }
+
+      [Test]
+    public void TestCompareStringValues() {
+      TestInteropPersonLite person = TestInteropPersonLite.CreateBuilder()
+        .SetId(123)
+        .SetName("abc")
+        .SetEmail("abc@123.com")
+        .AddRangeCodes(new[] { 1, 2, 3 })
+        .AddPhone(TestInteropPersonLite.Types.PhoneNumber.CreateBuilder().SetNumber("555-1234").Build())
+        .AddPhone(TestInteropPersonLite.Types.PhoneNumber.CreateBuilder().SetNumber(System.Text.Encoding.ASCII.GetString(AllBytes.ToByteArray())).Build())
+        .AddAddresses(TestInteropPersonLite.Types.Addresses.CreateBuilder().SetAddress("123 Seseme").SetCity("Wonderland").SetState("NA").SetZip(12345).Build())
+        .SetExtension(UnitTestExtrasLiteProtoFile.EmployeeIdLite, TestInteropEmployeeIdLite.CreateBuilder().SetNumber("123").Build())
+        .Build();
+      Assert.IsTrue(person.IsInitialized);
+
+      ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+      UnitTestExtrasFullProtoFile.RegisterAllExtensions(registry);
+
+      TestInteropPerson copy = TestInteropPerson.ParseFrom(person.ToByteArray(), registry);
+
+      Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+
+      TestInteropPerson.Builder copyBuilder = TestInteropPerson.CreateBuilder();
+      TextFormat.Merge(person.ToString().Replace("[protobuf_unittest_extra.employee_id_lite]", "[protobuf_unittest_extra.employee_id]"), registry, copyBuilder);
+
+      copy = copyBuilder.Build();
+      Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+
+      string liteText = person.ToString().TrimEnd().Replace("\r", "");
+      string fullText = copy.ToString().TrimEnd().Replace("\r", "");
+      //map the extension type
+      liteText = liteText.Replace("[protobuf_unittest_extra.employee_id_lite]", "[protobuf_unittest_extra.employee_id]");
+      //lite version does not indent
+      while (fullText.IndexOf("\n ") >= 0)
+        fullText = fullText.Replace("\n ", "\n");
+
+      Assert.AreEqual(fullText, liteText);
+    }
+  }
+}

src/ProtocolBuffersLite.Test/LiteTest.cs

@@ -0,0 +1,112 @@
+#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.IO;
+using Google.ProtocolBuffers.Descriptors;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Miscellaneous tests for message operations that apply to both
+  /// generated and dynamic messages.
+  /// </summary>
+  [TestFixture]
+  public class LiteTest {
+    [Test]
+    public void TestLite() {
+      // Since lite messages are a subset of regular messages, we can mostly
+      // assume that the functionality of lite messages is already thoroughly
+      // tested by the regular tests.  All this test really verifies is that
+      // a proto with optimize_for = LITE_RUNTIME compiles correctly when
+      // linked only against the lite library.  That is all tested at compile
+      // time, leaving not much to do in this method.  Let's just do some random
+      // stuff to make sure the lite message is actually here and usable.
+
+      TestAllTypesLite message =
+        TestAllTypesLite.CreateBuilder()
+                        .SetOptionalInt32(123)
+                        .AddRepeatedString("hello")
+                        .SetOptionalNestedMessage(
+                            TestAllTypesLite.Types.NestedMessage.CreateBuilder().SetBb(7))
+                        .Build();
+
+      ByteString data = message.ToByteString();
+
+      TestAllTypesLite message2 = TestAllTypesLite.ParseFrom(data);
+
+      Assert.AreEqual(123, message2.OptionalInt32);
+      Assert.AreEqual(1, message2.RepeatedStringCount);
+      Assert.AreEqual("hello", message2.RepeatedStringList[0]);
+      Assert.AreEqual(7, message2.OptionalNestedMessage.Bb);
+    }
+
+    [Test]
+    public void TestLiteExtensions() {
+      // TODO(kenton):  Unlike other features of the lite library, extensions are
+      //   implemented completely differently from the regular library.  We
+      //   should probably test them more thoroughly.
+
+      TestAllExtensionsLite message =
+        TestAllExtensionsLite.CreateBuilder()
+          .SetExtension(UnitTestLiteProtoFile.OptionalInt32ExtensionLite, 123)
+          .AddExtension(UnitTestLiteProtoFile.RepeatedStringExtensionLite, "hello")
+          .SetExtension(UnitTestLiteProtoFile.OptionalNestedEnumExtensionLite,
+              TestAllTypesLite.Types.NestedEnum.BAZ)
+          .SetExtension(UnitTestLiteProtoFile.OptionalNestedMessageExtensionLite,
+              TestAllTypesLite.Types.NestedMessage.CreateBuilder().SetBb(7).Build())
+          .Build();
+
+      // Test copying a message, since coping extensions actually does use a
+      // different code path between lite and regular libraries, and as of this
+      // writing, parsing hasn't been implemented yet.
+      TestAllExtensionsLite message2 = message.ToBuilder().Build();
+
+      Assert.AreEqual(123, (int)message2.GetExtension(
+          UnitTestLiteProtoFile.OptionalInt32ExtensionLite));
+      Assert.AreEqual(1, message2.GetExtensionCount(
+          UnitTestLiteProtoFile.RepeatedStringExtensionLite));
+      Assert.AreEqual(1, message2.GetExtension(
+          UnitTestLiteProtoFile.RepeatedStringExtensionLite).Count);
+      Assert.AreEqual("hello", message2.GetExtension(
+          UnitTestLiteProtoFile.RepeatedStringExtensionLite, 0));
+      Assert.AreEqual(TestAllTypesLite.Types.NestedEnum.BAZ, message2.GetExtension(
+          UnitTestLiteProtoFile.OptionalNestedEnumExtensionLite));
+      Assert.AreEqual(7, message2.GetExtension(
+          UnitTestLiteProtoFile.OptionalNestedMessageExtensionLite).Bb);
+    }
+  }
+}

src/ProtocolBuffersLite.Test/MissingFieldAndExtensionTest.cs

@@ -0,0 +1,219 @@
+#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.IO;
+using NUnit.Framework;
+using System.Collections.Generic;
+using Google.ProtocolBuffers.TestProtos;
+
+namespace Google.ProtocolBuffers {
+    [TestFixture]
+    public class MissingFieldAndExtensionTest {
+        [Test]
+        public void TestRecoverMissingExtensions() {
+            const int optionalInt32 = 12345678;
+            TestAllExtensions.Builder builder = TestAllExtensions.CreateBuilder();
+            builder.SetExtension(UnitTestProtoFile.OptionalInt32Extension, optionalInt32);
+            builder.AddExtension(UnitTestProtoFile.RepeatedDoubleExtension, 1.1);
+            builder.AddExtension(UnitTestProtoFile.RepeatedDoubleExtension, 1.2);
+            builder.AddExtension(UnitTestProtoFile.RepeatedDoubleExtension, 1.3);
+            TestAllExtensions msg = builder.Build();
+
+            Assert.IsTrue(msg.HasExtension(UnitTestProtoFile.OptionalInt32Extension));
+            Assert.AreEqual(3, msg.GetExtensionCount(UnitTestProtoFile.RepeatedDoubleExtension));
+
+            byte[] bits = msg.ToByteArray();
+            TestAllExtensions copy = TestAllExtensions.ParseFrom(bits);
+            Assert.IsFalse(copy.HasExtension(UnitTestProtoFile.OptionalInt32Extension));
+            Assert.AreEqual(0, copy.GetExtensionCount(UnitTestProtoFile.RepeatedDoubleExtension));
+            Assert.AreNotEqual(msg, copy);
+
+            //Even though copy does not understand the typees they serialize correctly
+            byte[] copybits = copy.ToByteArray();
+            Assert.AreEqual(bits, copybits);
+
+            ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+            UnitTestProtoFile.RegisterAllExtensions(registry);
+
+            //Now we can take those copy bits and restore the full message with extensions
+            copy = TestAllExtensions.ParseFrom(copybits, registry);
+            Assert.IsTrue(copy.HasExtension(UnitTestProtoFile.OptionalInt32Extension));
+            Assert.AreEqual(3, copy.GetExtensionCount(UnitTestProtoFile.RepeatedDoubleExtension));
+
+            Assert.AreEqual(msg, copy);
+            Assert.AreEqual(bits, copy.ToByteArray());
+
+            //If we modify the object this should all continue to work as before
+            copybits = copy.ToBuilder().Build().ToByteArray();
+            Assert.AreEqual(bits, copybits);
+
+            //If we replace extension the object this should all continue to work as before
+            copybits = copy.ToBuilder()
+                .SetExtension(UnitTestProtoFile.OptionalInt32Extension, optionalInt32)
+                .Build().ToByteArray();
+            Assert.AreEqual(bits, copybits);
+        }
+
+        [Test]
+        public void TestRecoverMissingFields() {
+            TestMissingFieldsA msga = TestMissingFieldsA.CreateBuilder()
+                .SetId(1001)
+                .SetName("Name")
+                .SetEmail("missing@field.value")
+                .Build();
+
+            //serialize to type B and verify all fields exist
+            TestMissingFieldsB msgb = TestMissingFieldsB.ParseFrom(msga.ToByteArray());
+            Assert.AreEqual(1001, msgb.Id);
+            Assert.AreEqual("Name", msgb.Name);
+            Assert.IsFalse(msgb.HasWebsite);
+            Assert.AreEqual(1, msgb.UnknownFields.FieldDictionary.Count);
+            Assert.AreEqual("missing@field.value", msgb.UnknownFields[TestMissingFieldsA.EmailFieldNumber].LengthDelimitedList[0].ToStringUtf8());
+
+            //serializes exactly the same (at least for this simple example)
+            Assert.AreEqual(msga.ToByteArray(), msgb.ToByteArray());
+            Assert.AreEqual(msga, TestMissingFieldsA.ParseFrom(msgb.ToByteArray()));
+
+            //now re-create an exact copy of A from serialized B
+            TestMissingFieldsA copya = TestMissingFieldsA.ParseFrom(msgb.ToByteArray());
+            Assert.AreEqual(msga, copya);
+            Assert.AreEqual(1001, copya.Id);
+            Assert.AreEqual("Name", copya.Name);
+            Assert.AreEqual("missing@field.value", copya.Email);
+
+            //Now we modify B... and try again
+            msgb = msgb.ToBuilder().SetWebsite("http://new.missing.field").Build();
+            //Does B still have the missing field?
+            Assert.AreEqual(1, msgb.UnknownFields.FieldDictionary.Count);
+
+            //Convert back to A and see if all fields are there?
+            copya = TestMissingFieldsA.ParseFrom(msgb.ToByteArray());
+            Assert.AreNotEqual(msga, copya);
+            Assert.AreEqual(1001, copya.Id);
+            Assert.AreEqual("Name", copya.Name);
+            Assert.AreEqual("missing@field.value", copya.Email);
+            Assert.AreEqual(1, copya.UnknownFields.FieldDictionary.Count);
+            Assert.AreEqual("http://new.missing.field", copya.UnknownFields[TestMissingFieldsB.WebsiteFieldNumber].LengthDelimitedList[0].ToStringUtf8());
+
+            //Lastly we can even still trip back to type B and see all fields:
+            TestMissingFieldsB copyb = TestMissingFieldsB.ParseFrom(copya.ToByteArray());
+            Assert.AreEqual(copya.ToByteArray().Length, copyb.ToByteArray().Length); //not exact order.
+            Assert.AreEqual(1001, copyb.Id);
+            Assert.AreEqual("Name", copyb.Name);
+            Assert.AreEqual("http://new.missing.field", copyb.Website);
+            Assert.AreEqual(1, copyb.UnknownFields.FieldDictionary.Count);
+            Assert.AreEqual("missing@field.value", copyb.UnknownFields[TestMissingFieldsA.EmailFieldNumber].LengthDelimitedList[0].ToStringUtf8());
+        }
+
+        [Test]
+        public void TestRecoverMissingMessage() {
+            TestMissingFieldsA.Types.SubA suba = TestMissingFieldsA.Types.SubA.CreateBuilder().SetCount(3).AddValues("a").AddValues("b").AddValues("c").Build();
+            TestMissingFieldsA msga = TestMissingFieldsA.CreateBuilder()
+                .SetId(1001)
+                .SetName("Name")
+                .SetTestA(suba)
+                .Build();
+
+            //serialize to type B and verify all fields exist
+            TestMissingFieldsB msgb = TestMissingFieldsB.ParseFrom(msga.ToByteArray());
+            Assert.AreEqual(1001, msgb.Id);
+            Assert.AreEqual("Name", msgb.Name);
+            Assert.AreEqual(1, msgb.UnknownFields.FieldDictionary.Count);
+            Assert.AreEqual(suba.ToString(), TestMissingFieldsA.Types.SubA.ParseFrom(msgb.UnknownFields[TestMissingFieldsA.TestAFieldNumber].LengthDelimitedList[0]).ToString());
+
+            //serializes exactly the same (at least for this simple example)
+            Assert.AreEqual(msga.ToByteArray(), msgb.ToByteArray());
+            Assert.AreEqual(msga, TestMissingFieldsA.ParseFrom(msgb.ToByteArray()));
+
+            //now re-create an exact copy of A from serialized B
+            TestMissingFieldsA copya = TestMissingFieldsA.ParseFrom(msgb.ToByteArray());
+            Assert.AreEqual(msga, copya);
+            Assert.AreEqual(1001, copya.Id);
+            Assert.AreEqual("Name", copya.Name);
+            Assert.AreEqual(suba, copya.TestA);
+
+            //Now we modify B... and try again
+            TestMissingFieldsB.Types.SubB subb = TestMissingFieldsB.Types.SubB.CreateBuilder().AddValues("test-b").Build();
+            msgb = msgb.ToBuilder().SetTestB(subb).Build();
+            //Does B still have the missing field?
+            Assert.AreEqual(1, msgb.UnknownFields.FieldDictionary.Count);
+
+            //Convert back to A and see if all fields are there?
+            copya = TestMissingFieldsA.ParseFrom(msgb.ToByteArray());
+            Assert.AreNotEqual(msga, copya);
+            Assert.AreEqual(1001, copya.Id);
+            Assert.AreEqual("Name", copya.Name);
+            Assert.AreEqual(suba, copya.TestA);
+            Assert.AreEqual(1, copya.UnknownFields.FieldDictionary.Count);
+            Assert.AreEqual(subb.ToByteArray(), copya.UnknownFields[TestMissingFieldsB.TestBFieldNumber].LengthDelimitedList[0].ToByteArray());
+
+            //Lastly we can even still trip back to type B and see all fields:
+            TestMissingFieldsB copyb = TestMissingFieldsB.ParseFrom(copya.ToByteArray());
+            Assert.AreEqual(copya.ToByteArray().Length, copyb.ToByteArray().Length); //not exact order.
+            Assert.AreEqual(1001, copyb.Id);
+            Assert.AreEqual("Name", copyb.Name);
+            Assert.AreEqual(subb, copyb.TestB);
+            Assert.AreEqual(1, copyb.UnknownFields.FieldDictionary.Count);
+        }
+
+        [Test]
+        public void TestRestoreFromOtherType() {
+            TestInteropPerson person = TestInteropPerson.CreateBuilder()
+                .SetId(123)
+                .SetName("abc")
+                .SetEmail("abc@123.com")
+                .AddRangeCodes(new[] {1, 2, 3})
+                .AddPhone(TestInteropPerson.Types.PhoneNumber.CreateBuilder().SetNumber("555-1234").Build())
+                .AddPhone(TestInteropPerson.Types.PhoneNumber.CreateBuilder().SetNumber("555-5678").Build())
+                .AddAddresses(TestInteropPerson.Types.Addresses.CreateBuilder().SetAddress("123 Seseme").SetCity("Wonderland").SetState("NA").SetZip(12345).Build())
+                .SetExtension(UnitTestExtrasFullProtoFile.EmployeeId, TestInteropEmployeeId.CreateBuilder().SetNumber("123").Build())
+                .Build();
+            Assert.IsTrue(person.IsInitialized);
+
+            TestEmptyMessage temp = TestEmptyMessage.ParseFrom(person.ToByteArray());
+            Assert.AreEqual(7, temp.UnknownFields.FieldDictionary.Count);
+            temp = temp.ToBuilder().Build();
+            Assert.AreEqual(7, temp.UnknownFields.FieldDictionary.Count);
+
+            ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+            UnitTestExtrasFullProtoFile.RegisterAllExtensions(registry);
+
+            TestInteropPerson copy = TestInteropPerson.ParseFrom(temp.ToByteArray(), registry);
+            Assert.AreEqual(person, copy);
+            Assert.AreEqual(person.ToByteArray(), copy.ToByteArray());
+        }
+    }
+}

src/ProtocolBuffersLite.Test/ProtocolBuffersLite.Test.csproj

@@ -0,0 +1,110 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{EE01ED24-3750-4567-9A23-1DB676A15610}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.ProtocolBuffers</RootNamespace>
+    <AssemblyName>Google.ProtocolBuffersLite.Test</AssemblyName>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>..\ProtocolBuffers.Test\Properties\Google.ProtocolBuffers.Test.snk</AssemblyOriginatorKeyFile>
+    <FileUpgradeFlags>
+    </FileUpgradeFlags>
+    <OldToolsVersion>3.5</OldToolsVersion>
+    <UpgradeBackupLocation />
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+  </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 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="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\ProtocolBuffers.Test\Properties\AssemblyInfo.cs">
+      <Link>Properties\AssemblyInfo.cs</Link>
+    </Compile>
+    <Compile Include="AbstractBuilderLiteTest.cs" />
+    <Compile Include="AbstractMessageLiteTest.cs" />
+    <Compile Include="ExtendableBuilderLiteTest.cs" />
+    <Compile Include="ExtendableMessageLiteTest.cs" />
+    <Compile Include="LiteTest.cs" />
+    <Compile Include="TestLiteByApi.cs" />
+    <Compile Include="TestProtos\UnitTestExtrasLiteProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestImportLiteProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestLiteProtoFile.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="..\ProtocolBuffers.Test\Properties\Google.ProtocolBuffers.Test.snk">
+      <Link>Properties\Google.ProtocolBuffers.Test.snk</Link>
+    </None>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\ProtocolBuffers\ProtocolBuffersLite.csproj">
+      <Project>{6969BDCE-D925-43F3-94AC-A531E6DF2591}</Project>
+      <Name>ProtocolBuffersLite</Name>
+      <Private>True</Private>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

src/ProtocolBuffersLite.Test/ProtocolBuffersLiteMixed.Test.csproj

@@ -0,0 +1,115 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{EEFFED24-3750-4567-9A23-1DB676A15610}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.ProtocolBuffers</RootNamespace>
+    <AssemblyName>Google.ProtocolBuffersMixedLite.Test</AssemblyName>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>..\ProtocolBuffers.Test\Properties\Google.ProtocolBuffers.Test.snk</AssemblyOriginatorKeyFile>
+    <FileUpgradeFlags>
+    </FileUpgradeFlags>
+    <OldToolsVersion>3.5</OldToolsVersion>
+    <UpgradeBackupLocation />
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <NoStdLib>true</NoStdLib>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <NoStdLib>true</NoStdLib>
+    <WarningLevel>4</WarningLevel>
+  </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 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="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\ProtocolBuffers.Test\Properties\AssemblyInfo.cs">
+      <Link>Properties\AssemblyInfo.cs</Link>
+    </Compile>
+    <Compile Include="AbstractBuilderLiteTest.cs" />
+    <Compile Include="AbstractMessageLiteTest.cs" />
+    <Compile Include="ExtendableBuilderLiteTest.cs" />
+    <Compile Include="ExtendableMessageLiteTest.cs" />
+    <Compile Include="InteropLiteTest.cs" />
+    <Compile Include="LiteTest.cs" />
+    <Compile Include="MissingFieldAndExtensionTest.cs" />
+    <Compile Include="TestLiteByApi.cs" />
+    <Compile Include="TestProtos\UnitTestExtrasFullProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestExtrasLiteProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestImportLiteProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestImportProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestLiteImportNonLiteProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestLiteProtoFile.cs" />
+    <Compile Include="TestProtos\UnitTestProtoFile.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="..\ProtocolBuffers.Test\Properties\Google.ProtocolBuffers.Test.snk">
+      <Link>Properties\Google.ProtocolBuffers.Test.snk</Link>
+    </None>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\ProtocolBuffers\ProtocolBuffers.csproj">
+      <Project>{6908BDCE-D925-43F3-94AC-A531E6DF2591}</Project>
+      <Name>ProtocolBuffers</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

src/ProtocolBuffersLite.Test/TestLiteByApi.cs

@@ -0,0 +1,116 @@
+#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 Google.ProtocolBuffers;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class TestLiteByApi {
+
+    [Test]
+    public void TestAllTypesEquality() {
+      TestAllTypesLite msg = TestAllTypesLite.DefaultInstance;
+      TestAllTypesLite copy = msg.ToBuilder().Build();
+      Assert.AreEqual(msg.GetHashCode(), copy.GetHashCode());
+      Assert.IsTrue(msg.Equals(copy));
+      msg = msg.ToBuilder().SetOptionalString("Hi").Build();
+      Assert.AreNotEqual(msg.GetHashCode(), copy.GetHashCode());
+      Assert.IsFalse(msg.Equals(copy));
+      copy = copy.ToBuilder().SetOptionalString("Hi").Build();
+      Assert.AreEqual(msg.GetHashCode(), copy.GetHashCode());
+      Assert.IsTrue(msg.Equals(copy));
+    }
+
+    [Test]
+    public void TestEqualityOnExtensions() {
+      TestAllExtensionsLite msg = TestAllExtensionsLite.DefaultInstance;
+      TestAllExtensionsLite copy = msg.ToBuilder().Build();
+      Assert.AreEqual(msg.GetHashCode(), copy.GetHashCode());
+      Assert.IsTrue(msg.Equals(copy));
+      msg = msg.ToBuilder().SetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite, "Hi").Build();
+      Assert.AreNotEqual(msg.GetHashCode(), copy.GetHashCode());
+      Assert.IsFalse(msg.Equals(copy));
+      copy = copy.ToBuilder().SetExtension(UnitTestLiteProtoFile.OptionalStringExtensionLite, "Hi").Build();
+      Assert.AreEqual(msg.GetHashCode(), copy.GetHashCode());
+      Assert.IsTrue(msg.Equals(copy));
+    }
+
+    [Test]
+    public void TestAllTypesToString() {
+      TestAllTypesLite msg = TestAllTypesLite.DefaultInstance;
+      TestAllTypesLite copy = msg.ToBuilder().Build();
+      Assert.AreEqual(msg.ToString(), copy.ToString());
+      Assert.IsEmpty(msg.ToString());
+      msg = msg.ToBuilder().SetOptionalInt32(-1).Build();
+      Assert.AreEqual("optional_int32: -1", msg.ToString().TrimEnd());
+      msg = msg.ToBuilder().SetOptionalString("abc123").Build();
+      Assert.AreEqual("optional_int32: -1\noptional_string: \"abc123\"", msg.ToString().Replace("\r", "").TrimEnd());
+    }
+
+    [Test]
+    public void TestAllTypesDefaultedRoundTrip() {
+      TestAllTypesLite msg = TestAllTypesLite.DefaultInstance;
+      Assert.IsTrue(msg.IsInitialized);
+      TestAllTypesLite copy = TestAllTypesLite.CreateBuilder().MergeFrom(msg.ToByteArray()).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+    [Test]
+    public void TestAllTypesModifiedRoundTrip() {
+      TestAllTypesLite msg = TestAllTypesLite.DefaultInstance;
+      msg.ToBuilder()
+        .SetOptionalBool(true)
+        .SetOptionalCord("Hi")
+        .SetOptionalDouble(1.123)
+        .SetOptionalForeignEnum(ForeignEnumLite.FOREIGN_LITE_FOO)
+        .SetOptionalForeignMessage(ForeignMessageLite.CreateBuilder().SetC('c').Build())
+        .SetOptionalGroup(TestAllTypesLite.Types.OptionalGroup.CreateBuilder().SetA('a').Build())
+        .SetOptionalImportEnum(ImportEnumLite.IMPORT_LITE_BAR)
+        .SetOptionalInt32(32)
+        .SetOptionalInt64(64)
+        .SetOptionalNestedEnum(TestAllTypesLite.Types.NestedEnum.FOO)
+        .SetOptionalString("SetOptionalString")
+        .AddRepeatedGroup(TestAllTypesLite.Types.RepeatedGroup.CreateBuilder().SetA('a').Build())
+        .AddRepeatedGroup(TestAllTypesLite.Types.RepeatedGroup.CreateBuilder().SetA('A').Build())
+        ;
+      TestAllTypesLite copy = TestAllTypesLite.CreateBuilder().MergeFrom(msg.ToByteArray()).Build();
+      Assert.AreEqual(msg.ToByteArray(), copy.ToByteArray());
+    }
+
+  }
+}

src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs

@@ -0,0 +1,246 @@
+// 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 UnitTestImportLiteProtoFile {
+  
+    #region Extension registration
+    public static void RegisterAllExtensions(pb::ExtensionRegistry registry) {
+    }
+    #endregion
+    #region Static variables
+    #endregion
+    #region Extensions
+    internal static readonly object Descriptor;
+    static UnitTestImportLiteProtoFile() {
+      Descriptor = null;
+    }
+    #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::GeneratedMessageLite<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 const int DFieldNumber = 1;
+    private bool hasD;
+    private int d_ = 0;
+    public bool HasD {
+      get { return hasD; }
+    }
+    public int D {
+      get { return d_; }
+    }
+    
+    public override bool IsInitialized {
+      get {
+        return true;
+      }
+    }
+    
+    public override void WriteTo(pb::CodedOutputStream output) {
+      int size = SerializedSize;
+      if (HasD) {
+        output.WriteInt32(1, D);
+      }
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public override int SerializedSize {
+      get {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+        
+        size = 0;
+        if (HasD) {
+          size += pb::CodedOutputStream.ComputeInt32Size(1, D);
+        }
+        memoizedSerializedSize = size;
+        return size;
+      }
+    }
+    
+    #region Lite runtime methods
+    public override int GetHashCode() {
+      int hash = GetType().GetHashCode();
+      if (hasD) hash ^= d_.GetHashCode();
+      return hash;
+    }
+    
+    public override bool Equals(object obj) {
+      ImportMessageLite other = obj as ImportMessageLite;
+      if (other == null) return false;
+      if (hasD != other.hasD || (hasD && !d_.Equals(other.d_))) return false;
+      return true;
+    }
+    
+    public override void PrintTo(global::System.IO.TextWriter writer) {
+      PrintField("d", hasD, d_, writer);
+    }
+    #endregion
+    
+    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::GeneratedBuilderLite<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 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 override Builder MergeFrom(pb::IMessageLite other) {
+        if (other is ImportMessageLite) {
+          return MergeFrom((ImportMessageLite) other);
+        } else {
+          base.MergeFrom(other);
+          return this;
+        }
+      }
+      
+      public override Builder MergeFrom(ImportMessageLite other) {
+        if (other == global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.DefaultInstance) return this;
+        if (other.HasD) {
+          D = other.D;
+        }
+        return this;
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input) {
+        return MergeFrom(input, pb::ExtensionRegistry.Empty);
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {
+        while (true) {
+          uint tag = input.ReadTag();
+          switch (tag) {
+            case 0: {
+              return this;
+            }
+            default: {
+              if (pb::WireFormat.IsEndGroupTag(tag)) {
+                return this;
+              }
+              ParseUnknownField(input, extensionRegistry, tag);
+              break;
+            }
+            case 8: {
+              D = input.ReadInt32();
+              break;
+            }
+          }
+        }
+      }
+      
+      
+      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/ProtocolBuffersLite.Test/TestProtos/UnitTestImportProtoFile.cs

@@ -0,0 +1,280 @@
+// 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 UnitTestImportProtoFile {
+  
+    #region Extension registration
+    public static void RegisterAllExtensions(pb::ExtensionRegistry registry) {
+    }
+    #endregion
+    #region Static variables
+    internal static pbd::MessageDescriptor internal__static_protobuf_unittest_import_ImportMessage__Descriptor;
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ImportMessage, global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder> internal__static_protobuf_unittest_import_ImportMessage__FieldAccessorTable;
+    #endregion
+    #region Descriptor
+    public static pbd::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbd::FileDescriptor descriptor;
+    
+    static UnitTestImportProtoFile() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          "CiVnb29nbGUvcHJvdG9idWYvdW5pdHRlc3RfaW1wb3J0LnByb3RvEhhwcm90" + 
+          "b2J1Zl91bml0dGVzdF9pbXBvcnQaJGdvb2dsZS9wcm90b2J1Zi9jc2hhcnBf" + 
+          "b3B0aW9ucy5wcm90byIaCg1JbXBvcnRNZXNzYWdlEgkKAWQYASABKAUqPAoK" + 
+          "SW1wb3J0RW51bRIOCgpJTVBPUlRfRk9PEAcSDgoKSU1QT1JUX0JBUhAIEg4K" + 
+          "CklNUE9SVF9CQVoQCUJbChhjb20uZ29vZ2xlLnByb3RvYnVmLnRlc3RIAcI+" + 
+          "PAohR29vZ2xlLlByb3RvY29sQnVmZmVycy5UZXN0UHJvdG9zEhdVbml0VGVz" + 
+          "dEltcG9ydFByb3RvRmlsZQ==");
+      pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {
+        descriptor = root;
+        internal__static_protobuf_unittest_import_ImportMessage__Descriptor = Descriptor.MessageTypes[0];
+        internal__static_protobuf_unittest_import_ImportMessage__FieldAccessorTable = 
+            new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ImportMessage, global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder>(internal__static_protobuf_unittest_import_ImportMessage__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 ImportEnum {
+    IMPORT_FOO = 7,
+    IMPORT_BAR = 8,
+    IMPORT_BAZ = 9,
+  }
+  
+  #endregion
+  
+  #region Messages
+  public sealed partial class ImportMessage : pb::GeneratedMessage<ImportMessage, ImportMessage.Builder> {
+    private static readonly ImportMessage defaultInstance = new Builder().BuildPartial();
+    public static ImportMessage DefaultInstance {
+      get { return defaultInstance; }
+    }
+    
+    public override ImportMessage DefaultInstanceForType {
+      get { return defaultInstance; }
+    }
+    
+    protected override ImportMessage ThisMessage {
+      get { return this; }
+    }
+    
+    public static pbd::MessageDescriptor Descriptor {
+      get { return global::Google.ProtocolBuffers.TestProtos.UnitTestImportProtoFile.internal__static_protobuf_unittest_import_ImportMessage__Descriptor; }
+    }
+    
+    protected override pb::FieldAccess.FieldAccessorTable<ImportMessage, ImportMessage.Builder> InternalFieldAccessors {
+      get { return global::Google.ProtocolBuffers.TestProtos.UnitTestImportProtoFile.internal__static_protobuf_unittest_import_ImportMessage__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 override bool IsInitialized {
+      get {
+        return true;
+      }
+    }
+    
+    public override void WriteTo(pb::CodedOutputStream output) {
+      int size = SerializedSize;
+      if (HasD) {
+        output.WriteInt32(1, D);
+      }
+      UnknownFields.WriteTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public override int SerializedSize {
+      get {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+        
+        size = 0;
+        if (HasD) {
+          size += pb::CodedOutputStream.ComputeInt32Size(1, D);
+        }
+        size += UnknownFields.SerializedSize;
+        memoizedSerializedSize = size;
+        return size;
+      }
+    }
+    
+    public static ImportMessage ParseFrom(pb::ByteString data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static ImportMessage ParseFrom(pb::ByteString data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessage ParseFrom(byte[] data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static ImportMessage ParseFrom(byte[] data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessage ParseFrom(global::System.IO.Stream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static ImportMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ImportMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
+    public static ImportMessage ParseFrom(pb::CodedInputStream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static ImportMessage 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(ImportMessage prototype) {
+      return (Builder) new Builder().MergeFrom(prototype);
+    }
+    
+    public sealed partial class Builder : pb::GeneratedBuilder<ImportMessage, Builder> {
+      protected override Builder ThisBuilder {
+        get { return this; }
+      }
+      public Builder() {}
+      
+      ImportMessage result = new ImportMessage();
+      
+      protected override ImportMessage MessageBeingBuilt {
+        get { return result; }
+      }
+      
+      public override Builder Clear() {
+        result = new ImportMessage();
+        return this;
+      }
+      
+      public override Builder Clone() {
+        return new Builder().MergeFrom(result);
+      }
+      
+      public override pbd::MessageDescriptor DescriptorForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.ImportMessage.Descriptor; }
+      }
+      
+      public override ImportMessage DefaultInstanceForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.ImportMessage.DefaultInstance; }
+      }
+      
+      public override ImportMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
+        ImportMessage returnMe = result;
+        result = null;
+        return returnMe;
+      }
+      
+      public override Builder MergeFrom(pb::IMessage other) {
+        if (other is ImportMessage) {
+          return MergeFrom((ImportMessage) other);
+        } else {
+          base.MergeFrom(other);
+          return this;
+        }
+      }
+      
+      public override Builder MergeFrom(ImportMessage other) {
+        if (other == global::Google.ProtocolBuffers.TestProtos.ImportMessage.DefaultInstance) return this;
+        if (other.HasD) {
+          D = other.D;
+        }
+        this.MergeUnknownFields(other.UnknownFields);
+        return this;
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input) {
+        return MergeFrom(input, pb::ExtensionRegistry.Empty);
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {
+        pb::UnknownFieldSet.Builder unknownFields = null;
+        while (true) {
+          uint tag = input.ReadTag();
+          switch (tag) {
+            case 0: {
+              if (unknownFields != null) {
+                this.UnknownFields = unknownFields.Build();
+              }
+              return this;
+            }
+            default: {
+              if (pb::WireFormat.IsEndGroupTag(tag)) {
+                if (unknownFields != null) {
+                  this.UnknownFields = unknownFields.Build();
+                }
+                return this;
+              }
+              if (unknownFields == null) {
+                unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
+              }
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              break;
+            }
+            case 8: {
+              D = input.ReadInt32();
+              break;
+            }
+          }
+        }
+      }
+      
+      
+      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 ImportMessage() {
+      object.ReferenceEquals(global::Google.ProtocolBuffers.TestProtos.UnitTestImportProtoFile.Descriptor, null);
+    }
+  }
+  
+  #endregion
+  
+}