Nano support for extensions and unknown fields.

You can use the processor option store_unknown_fields to switch
this support on:

  aprotoc --javanano_out=store_unknown_fields=true:/tmp/out

A separate option for extensions isn't required. Support
for unknown fields must be turned on to allow storing and
retrieving extensions, because they are just stored as
unknown fields. If unknown fields are switched on, extension
related code will be generated when a proto message includes
an extension range, or an extension is encountered.

By default, store_unknown_fields is false. No additional
code is generated, and the generator will error out if protos
contain extension ranges or extensions.

Change-Id: I1e034c9e8f3305612953f72438189a7da6ed2167

7 files changed, 308 insertions, 21 deletions

diff --git a/src/google/protobuf/compiler/javanano/javanano_extension.cc b/src/google/protobuf/compiler/javanano/javanano_extension.cc
new file mode 100644
index 0000000..ea74af9
--- /dev/null
+++ b/src/google/protobuf/compiler/javanano/javanano_extension.cc
@@ -0,0 +1,96 @@
+// 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: bduff@google.com (Brian Duff)
+
+#include <google/protobuf/compiler/javanano/javanano_extension.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/wire_format.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+using internal::WireFormat;
+
+void SetVariables(const FieldDescriptor* descriptor, const Params params,
+                  map<string, string>* variables) {
+  (*variables)["name"] = UnderscoresToCamelCase(descriptor);
+  (*variables)["number"] = SimpleItoa(descriptor->number());
+  (*variables)["extends"] = ClassName(params, descriptor->containing_type());
+
+  string type;
+  JavaType java_type = GetJavaType(descriptor->type());
+  switch (java_type) {
+    case JAVATYPE_ENUM:
+      type = "java.lang.Integer";
+      break;
+    case JAVATYPE_MESSAGE:
+      type = ClassName(params, descriptor->message_type());
+      break;
+    default:
+      type = BoxedPrimitiveTypeName(java_type);
+      break;
+  }
+  (*variables)["type"] = type;
+}
+
+ExtensionGenerator::
+ExtensionGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : params_(params), descriptor_(descriptor) {
+  SetVariables(descriptor, params, &variables_);
+}
+
+ExtensionGenerator::~ExtensionGenerator() {}
+
+void ExtensionGenerator::Generate(io::Printer* printer) const {
+  if (descriptor_->is_repeated()) {
+    printer->Print(variables_,
+      "// Extends $extends$\n"
+      "public static final com.google.protobuf.nano.Extension<java.util.List<$type$>> $name$ = \n"
+      "    com.google.protobuf.nano.Extension.createRepeated($number$,\n"
+      "        new com.google.protobuf.nano.Extension.TypeLiteral<java.util.List<$type$>>(){});\n");
+  } else {
+    printer->Print(variables_,
+      "// Extends $extends$\n"
+      "public static final com.google.protobuf.nano.Extension<$type$> $name$ =\n"
+      "    com.google.protobuf.nano.Extension.create($number$,\n"
+      "        new com.google.protobuf.nano.Extension.TypeLiteral<$type$>(){});\n");
+  }
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google
+
diff --git a/src/google/protobuf/compiler/javanano/javanano_extension.h b/src/google/protobuf/compiler/javanano/javanano_extension.h
new file mode 100644
index 0000000..c6543eb
--- /dev/null
+++ b/src/google/protobuf/compiler/javanano/javanano_extension.h
@@ -0,0 +1,74 @@
+// 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: bduff@google.com (Brian Duff)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_EXTENSION_H_
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_EXTENSION_H_
+
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/descriptor.pb.h>
+
+
+namespace google {
+namespace protobuf {
+  namespace io {
+    class Printer;             // printer.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class ExtensionGenerator {
+ public:
+  explicit ExtensionGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~ExtensionGenerator();
+
+  void Generate(io::Printer* printer) const;
+
+ private:
+  const Params& params_;
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ExtensionGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_EXTENSION_H_
diff --git a/src/google/protobuf/compiler/javanano/javanano_file.cc b/src/google/protobuf/compiler/javanano/javanano_file.cc
index 2f42fa0..6efa2bf 100644
--- a/src/google/protobuf/compiler/javanano/javanano_file.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_file.cc
@@ -34,6 +34,7 @@
 
 #include <google/protobuf/compiler/javanano/javanano_file.h>
 #include <google/protobuf/compiler/javanano/javanano_enum.h>
+#include <google/protobuf/compiler/javanano/javanano_extension.h>
 #include <google/protobuf/compiler/javanano/javanano_helpers.h>
 #include <google/protobuf/compiler/javanano/javanano_message.h>
 #include <google/protobuf/compiler/code_generator.h>
@@ -94,10 +95,11 @@ bool FileGenerator::Validate(string* error) {
   // Check for extensions
   FileDescriptorProto file_proto;
   file_->CopyTo(&file_proto);
-  if (UsesExtensions(file_proto)) {
+  if (UsesExtensions(file_proto) && !params_.store_unknown_fields()) {
     error->assign(file_->name());
     error->append(
-      ": Java NANO_RUNTIME does not support extensions\"");
+        ": Java NANO_RUNTIME only supports extensions when the "
+        "'store_unknown_fields' generator option is 'true'.");
     return false;
   }
 
@@ -179,6 +181,11 @@ void FileGenerator::Generate(io::Printer* printer) {
 
   // -----------------------------------------------------------------
 
+  // Extensions.
+  for (int i = 0; i < file_->extension_count(); i++) {
+    ExtensionGenerator(file_->extension(i), params_).Generate(printer);
+  }
+
   if (!params_.java_multiple_files()) {
     for (int i = 0; i < file_->enum_type_count(); i++) {
       EnumGenerator(file_->enum_type(i), params_).Generate(printer);
diff --git a/src/google/protobuf/compiler/javanano/javanano_generator.cc b/src/google/protobuf/compiler/javanano/javanano_generator.cc
index 554f6d4..19a3dcc 100644
--- a/src/google/protobuf/compiler/javanano/javanano_generator.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_generator.cc
@@ -115,6 +115,8 @@ bool JavaNanoGenerator::Generate(const FileDescriptor* file,
           return false;
         }
         params.set_java_outer_classname(parts[0], parts[1]);
+    } else if (options[i].first == "store_unknown_fields") {
+      params.set_store_unknown_fields(options[i].second == "true");
     } else if (options[i].first == "java_multiple_files") {
         params.set_java_multiple_files(options[i].second == "true");
     } else {
diff --git a/src/google/protobuf/compiler/javanano/javanano_message.cc b/src/google/protobuf/compiler/javanano/javanano_message.cc
index f8a4fe7..2740779 100644
--- a/src/google/protobuf/compiler/javanano/javanano_message.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_message.cc
@@ -36,6 +36,7 @@
 #include <google/protobuf/stubs/hash.h>
 #include <google/protobuf/compiler/javanano/javanano_message.h>
 #include <google/protobuf/compiler/javanano/javanano_enum.h>
+#include <google/protobuf/compiler/javanano/javanano_extension.h>
 #include <google/protobuf/compiler/javanano/javanano_helpers.h>
 #include <google/protobuf/stubs/strutil.h>
 #include <google/protobuf/io/printer.h>
@@ -117,10 +118,6 @@ void MessageGenerator::GenerateStaticVariableInitializers(
     MessageGenerator(descriptor_->nested_type(i), params_)
       .GenerateStaticVariableInitializers(printer);
   }
-
-  if (descriptor_->extension_count() != 0) {
-    GOOGLE_LOG(FATAL) << "Extensions not supported in NANO_RUNTIME\n";
-  }
 }
 
 void MessageGenerator::Generate(io::Printer* printer) {
@@ -135,9 +132,10 @@ void MessageGenerator::Generate(io::Printer* printer) {
   GOOGLE_LOG(INFO) << "has_java_outer_classname()=" << params_.has_java_outer_classname(file_->name());
 #endif
 
-  if ((descriptor_->extension_count() != 0)
-      || (descriptor_->extension_range_count() != 0)) {
-    GOOGLE_LOG(FATAL) << "Extensions not supported in NANO_RUNTIME\n";
+  if (!params_.store_unknown_fields() &&
+      (descriptor_->extension_count() != 0 || descriptor_->extension_range_count() != 0)) {
+    GOOGLE_LOG(FATAL) << "Extensions are only supported in NANO_RUNTIME if the "
+        "'store_unknown_fields' generator option is 'true'\n";
   }
 
   // Note: Fields (which will be emitted in the loop, below) may have the same names as fields in
@@ -156,7 +154,17 @@ void MessageGenerator::Generate(io::Printer* printer) {
     "\n",
     "classname", descriptor_->name());
 
+  if (params_.store_unknown_fields()) {
+    printer->Print(
+        "private java.util.List<com.google.protobuf.nano.UnknownFieldData>\n"
+        "    unknownFieldData;\n");
+  }
+
   // Nested types and extensions
+  for (int i = 0; i < descriptor_->extension_count(); i++) {
+    ExtensionGenerator(descriptor_->extension(i), params_).Generate(printer);
+  }
+
   for (int i = 0; i < descriptor_->enum_type_count(); i++) {
     EnumGenerator(descriptor_->enum_type(i), params_).Generate(printer);
   }
@@ -173,6 +181,24 @@ void MessageGenerator::Generate(io::Printer* printer) {
   }
 
   GenerateClear(printer);
+
+  // If we have an extension range, generate accessors for extensions.
+  if (params_.store_unknown_fields()
+      && descriptor_->extension_range_count() > 0) {
+    printer->Print(
+      "public <T> T getExtension(com.google.protobuf.nano.Extension<T> extension) {\n"
+      "  return com.google.protobuf.nano.WireFormatNano.getExtension(\n"
+      "      extension, unknownFieldData);\n"
+      "}\n\n"
+      "public <T> void setExtension(com.google.protobuf.nano.Extension<T> extension, T value) {\n"
+      "  if (unknownFieldData == null) {\n"
+      "    unknownFieldData = \n"
+      "        new java.util.ArrayList<com.google.protobuf.nano.UnknownFieldData>();\n"
+      "  }\n"
+      "  com.google.protobuf.nano.WireFormatNano.setExtension(\n"
+      "      extension, value, unknownFieldData);\n"
+      "}\n\n");
+  }
   GenerateMessageSerializationMethods(printer);
   GenerateMergeFromMethods(printer);
   GenerateParseFromMethods(printer);
@@ -188,12 +214,8 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
   scoped_array<const FieldDescriptor*> sorted_fields(
     SortFieldsByNumber(descriptor_));
 
-  if (descriptor_->extension_range_count() != 0) {
-    GOOGLE_LOG(FATAL) << "Extensions not supported in NANO_RUNTIME\n";
-  }
-
   // writeTo only throws an exception if it contains one or more fields to write
-  if (descriptor_->field_count() > 0) {
+  if (descriptor_->field_count() > 0 || params_.store_unknown_fields()) {
     printer->Print(
       "@Override\n"
       "public void writeTo(com.google.protobuf.nano.CodedOutputByteBufferNano output)\n"
@@ -207,7 +229,14 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
 
   // Output the fields in sorted order
   for (int i = 0; i < descriptor_->field_count(); i++) {
-      GenerateSerializeOneField(printer, sorted_fields[i]);
+    GenerateSerializeOneField(printer, sorted_fields[i]);
+  }
+
+  // Write unknown fields.
+  if (params_.store_unknown_fields()) {
+    printer->Print(
+      "com.google.protobuf.nano.WireFormatNano.writeUnknownFields(\n"
+      "    unknownFieldData, output);\n");
   }
 
   printer->Outdent();
@@ -233,6 +262,11 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
     field_generators_.get(sorted_fields[i]).GenerateSerializedSizeCode(printer);
   }
 
+  if (params_.store_unknown_fields()) {
+    printer->Print(
+      "size += com.google.protobuf.nano.WireFormatNano.computeWireSize(unknownFieldData);\n");
+  }
+
   printer->Outdent();
   printer->Print(
     "  cachedSize = size;\n"
@@ -266,12 +300,28 @@ void MessageGenerator::GenerateMergeFromMethods(io::Printer* printer) {
   printer->Print(
     "case 0:\n"          // zero signals EOF / limit reached
     "  return this;\n"
-    "default: {\n"
-    "  if (!com.google.protobuf.nano.WireFormatNano.parseUnknownField(input, tag)) {\n"
-    "    return this;\n"   // it's an endgroup tag
-    "  }\n"
-    "  break;\n"
-    "}\n");
+    "default: {\n");
+
+  printer->Indent();
+  if (params_.store_unknown_fields()) {
+    printer->Print(
+        "if (unknownFieldData == null) {\n"
+        "  unknownFieldData = \n"
+        "      new java.util.ArrayList<com.google.protobuf.nano.UnknownFieldData>();\n"
+        "}\n"
+        "if (!com.google.protobuf.nano.WireFormatNano.storeUnknownField(unknownFieldData, \n"
+        "    input, tag)) {\n"
+        "  return this;\n"
+        "}\n");
+  } else {
+    printer->Print(
+        "if (!com.google.protobuf.nano.WireFormatNano.parseUnknownField(input, tag)) {\n"
+        "  return this;\n"   // it's an endgroup tag
+        "}\n");
+  }
+  printer->Print("break;\n");
+  printer->Outdent();
+  printer->Print("}\n");
 
   for (int i = 0; i < descriptor_->field_count(); i++) {
     const FieldDescriptor* field = sorted_fields[i];
@@ -356,6 +406,11 @@ void MessageGenerator::GenerateClear(io::Printer* printer) {
     }
   }
 
+  // Clear unknown fields.
+  if (params_.store_unknown_fields()) {
+    printer->Print("unknownFieldData = null;\n");
+  }
+
   printer->Outdent();
   printer->Print(
     "  cachedSize = -1;\n"
diff --git a/src/google/protobuf/compiler/javanano/javanano_params.h b/src/google/protobuf/compiler/javanano/javanano_params.h
index f6192ea..30eedff 100644
--- a/src/google/protobuf/compiler/javanano/javanano_params.h
+++ b/src/google/protobuf/compiler/javanano/javanano_params.h
@@ -49,6 +49,7 @@ class Params {
   string empty_;
   string base_name_;
   bool java_multiple_files_;
+  bool store_unknown_fields_;
   NameMap java_packages_;
   NameMap java_outer_classnames_;
 
@@ -56,6 +57,7 @@ class Params {
   Params(const string & base_name) :
     empty_(""),
     base_name_(base_name),
+    store_unknown_fields_(false),
     java_multiple_files_(false) {
   }
 
@@ -107,6 +109,13 @@ class Params {
     return java_outer_classnames_;
   }
 
+  void set_store_unknown_fields(bool value) {
+    store_unknown_fields_ = value;
+  }
+  bool store_unknown_fields() const {
+    return store_unknown_fields_;
+  }
+
   void set_java_multiple_files(bool value) {
     java_multiple_files_ = value;
   }
diff --git a/src/google/protobuf/unittest_extension_nano.proto b/src/google/protobuf/unittest_extension_nano.proto
new file mode 100644
index 0000000..f2906f0
--- /dev/null
+++ b/src/google/protobuf/unittest_extension_nano.proto
@@ -0,0 +1,44 @@
+syntax = "proto2";
+
+option java_outer_classname = "Extensions";
+option java_package = "com.google.protobuf.nano";
+
+message ExtendableMessage {
+  optional int32 field = 1;
+  extensions 10 to max;
+}
+
+enum AnEnum {
+  FIRST_VALUE = 1;
+  SECOND_VALUE = 2;
+}
+
+message AnotherMessage {
+  optional string string = 1;
+  optional bool value = 2;
+}
+
+extend ExtendableMessage {
+  optional string some_string = 10;
+  optional int32 some_int = 11;
+  optional int64 some_long = 12;
+  optional float some_float = 13;
+  optional double some_double = 14;
+  optional bool some_bool = 15;
+  optional AnEnum some_enum = 16;
+  optional AnotherMessage some_message = 17;
+  repeated string some_repeated_string = 18;
+  repeated int32 some_repeated_int = 19;
+  repeated int64 some_repeated_long = 20;
+  repeated float some_repeated_float = 21;
+  repeated double some_repeated_double = 22;
+  repeated bool some_repeated_bool = 23;
+  repeated AnEnum some_repeated_enum = 24;
+  repeated AnotherMessage some_repeated_message = 25;
+}
+
+message ContainerMessage {
+  extend ExtendableMessage {
+    optional bool another_thing = 100;
+  }
+}