Add option to the protoc code generator to avoid generating deprecated code

servicetalk-examples/grpc/protoc-options/build.gradle

@@ -74,6 +74,8 @@ protobuf {
           outputSubDir = "java"
           // Option to append a suffix to type names to avoid naming collisions with other code generation.
           option 'typeNameSuffix=St'
+          // Option to tell the compiler to exclude all Deprecated fields, types, and methods from the output
+          option 'skipDeprecated=true'
         }
       }
     }

servicetalk-examples/grpc/protoc-options/src/main/proto/test_service.proto

@@ -0,0 +1,37 @@
+//
+// Copyright © 2019 Apple Inc. and the ServiceTalk project authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+option java_multiple_files = true;
+option java_package = "io.servicetalk.grpc.netty";
+option java_outer_classname = "TesterProto";
+
+package grpc.netty;
+
+service Tester {
+    rpc test (TestRequest) returns (TestResponse) {}
+    rpc testBiDiStream (stream TestRequest) returns (stream TestResponse) {}
+    rpc testResponseStream (TestRequest) returns (stream TestResponse) {}
+    rpc testRequestStream (stream TestRequest) returns (TestResponse) {}
+}
+
+message TestRequest {
+    string name = 1;
+}
+
+message TestResponse {
+    string message = 1;
+}

servicetalk-grpc-api/src/main/java/io/servicetalk/grpc/api/GrpcRoutes.java

@@ -138,7 +138,9 @@ final Single<GrpcServerContext> bind(final ServerBinder binder, final GrpcExecut
      * In case you have a use-case, let us know.
      */
     @Deprecated
-    protected abstract void registerRoutes(Service service);    // FIXME: 0.43 - remove deprecated method
+    protected void registerRoutes(Service service) {    // FIXME: 0.43 - remove deprecated method
+        throw new UnsupportedOperationException("This method is not used starting from version 0.42.0");
+    }
 
     /**
      * Create a new {@link Service} from the passed {@link AllGrpcRoutes}.
@@ -150,7 +152,9 @@ final Single<GrpcServerContext> bind(final ServerBinder binder, final GrpcExecut
      * In case you have a use-case, let us know.
      */
     @Deprecated
-    protected abstract Service newServiceFromRoutes(AllGrpcRoutes routes);  // FIXME: 0.43 - remove deprecated method
+    protected Service newServiceFromRoutes(AllGrpcRoutes routes) {  // FIXME: 0.43 - remove deprecated method
+        throw new UnsupportedOperationException("This method is not used starting from version 0.42.0");
+    }
 
     static GrpcRoutes<?> merge(GrpcRoutes<?>... allRoutes) {
         final GrpcRouter.Builder[] builders = new GrpcRouter.Builder[allRoutes.length];

servicetalk-grpc-protoc/README.adoc

@@ -22,7 +22,7 @@ link:{source-root}/servicetalk-examples/grpc/helloworld[gRPC HelloWorld Example]
 This plugin supports the following
 link:https://developers.google.com/protocol-buffers/docs/reference/cpp/google.protobuf.compiler.command_line_interface[options]:
 
-==== `javaDocs=<true|false>`
+==== `javaDocs=<true|false>`  (default: true)
 Control if `javadoc` is generated by this plugin. Here is an example of how you can specify this option with gradle:
 
 [source,gradle]
@@ -47,7 +47,7 @@ And with Maven:
 </protocPlugin>
 ----
 
-==== `typeNameSuffix=<value>`
+==== `typeNameSuffix=<value>` (default: not enabled)
 Appends the <value> onto service type names generated by this plugin. This helps to avoid service type name
 collisions if other protoc plugins are generating code in the same gradle project, or in the same package name.
 
@@ -78,3 +78,36 @@ And with Maven:
   </args>
 </protocPlugin>
 ----
+
+==== `skipDeprecated=<true|false>` (default: false)
+Instructs the generator to remove all deprecated methods and fields from the generated code, as well as remove calls
+to deprecated code either to internal ServiceTalk libraries, or outside. This will almost certainly cause breaking changes
+to code that uses these deprecated methods but will be forward compatible.
+
+If you are using the
+link:https://github.com/google/protobuf-gradle-plugin#configure-what-to-generate[protobuf-gradle-plugin] this is how you
+can specify an option:
+
+[source,gradle]
+----
+task.plugins {
+  servicetalk_grpc {
+    option 'skipDeprecated=true'
+  }
+}
+----
+
+And with Maven:
+
+And with Maven:
+
+[source, xml]
+----
+<protocPlugin>
+  <id>servicetalk-grpc-protoc</id>
+  <!-- more params -->
+  <args>
+    <arg>skipDeprecated=true</arg>
+  </args>
+</protocPlugin>
+----