feat: support reserved enum values

pbj-core/pbj-compiler/src/main/antlr/com/hedera/hashgraph/protoparser/grammar/Protobuf3.g4

@@ -170,6 +170,7 @@ enumElement
   : optionStatement
   | optionComment
   | enumField
+  | reserved
   | emptyStatement_
   ;
 
@@ -205,6 +206,7 @@ messageElement
   | mapField
   | reserved
   | emptyStatement_
+  | DOC_COMMENT
   ;
 
 // service

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/EnumGenerator.java

@@ -84,6 +84,8 @@ public static void generateEnum(
                     System.err.printf(
                             "Unhandled Option: %s%n", item.optionStatement().getText());
                 }
+            } else if (item.reserved() != null) {
+                // Ignore reserved enum values
             } else {
                 System.err.printf("EnumGenerator Warning - Unknown element: %s -- %s%n", item, item.getText());
             }

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/ModelGenerator.java

@@ -97,7 +97,10 @@ public void generate(
 
         // Iterate over all the items in the protobuf schema
         for (final var item : msgDef.messageBody().messageElement()) {
-            if (item.messageDef() != null) { // process sub messages down below in generateClass()
+            if (item.messageDef() != null
+                    || item.enumDef() != null
+                    || item.DOC_COMMENT()
+                            != null) { // process sub messages and inner enums down below in generateClass()
             } else if (item.oneof() != null) { // process one ofs
                 oneofGetters.addAll(generateCodeForOneOf(
                         lookupHelper, item, javaRecordName, writer::addImport, oneofEnums, fields));

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/SchemaGenerator.java

@@ -32,7 +32,9 @@ public void generate(
         final String schemaClassName = lookupHelper.getUnqualifiedClassForMessage(FileType.SCHEMA, msgDef);
         final List<Field> fields = new ArrayList<>();
         for (final var item : msgDef.messageBody().messageElement()) {
-            if (item.messageDef() != null) { // process sub messages down below
+            if (item.messageDef() != null
+                    || item.enumDef() != null
+                    || item.DOC_COMMENT() != null) { // process sub messages down below
             } else if (item.oneof() != null) { // process one ofs
                 final var field = new OneOfField(item.oneof(), modelClassName, lookupHelper);
                 fields.add(field);

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/ServiceGenerator.java

@@ -475,6 +475,8 @@ public static void generateService(
                     System.err.printf(
                             "Unhandled Option: %s%n", item.optionStatement().getText());
                 }
+            } else if (item.optionComment() != null || item.emptyStatement_() != null) {
+                // Ignore these
             } else {
                 System.err.printf("ServiceGenerator Warning - Unknown element: %s -- %s%n", item, item.getText());
             }

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/TestGenerator.java

@@ -45,7 +45,9 @@ public void generate(
         writer.addImport(lookupHelper.getPackage(FileType.MODEL, msgDef) + ".*");
 
         for (final var item : msgDef.messageBody().messageElement()) {
-            if (item.messageDef() != null) { // process sub messages down below
+            if (item.messageDef() != null
+                    || item.enumDef() != null
+                    || item.DOC_COMMENT() != null) { // process sub messages down below
             } else if (item.oneof() != null) { // process one ofs
                 final var field = new OneOfField(item.oneof(), modelClassName, lookupHelper);
                 fields.add(field);

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/json/JsonCodecGenerator.java

@@ -36,7 +36,9 @@ public void generate(
         writer.addImport(lookupHelper.getPackage(FileType.SCHEMA, msgDef) + ".*");
 
         for (var item : msgDef.messageBody().messageElement()) {
-            if (item.messageDef() != null) { // process sub messages down below
+            if (item.messageDef() != null
+                    || item.enumDef() != null
+                    || item.DOC_COMMENT() != null) { // process sub messages down below
             } else if (item.oneof() != null) { // process one ofs
                 final var field = new OneOfField(item.oneof(), modelClassName, lookupHelper);
                 fields.add(field);

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/protobuf/CodecGenerator.java

@@ -40,7 +40,9 @@ public void generate(
         writer.addImport(lookupHelper.getPackage(FileType.SCHEMA, msgDef) + ".*");
 
         for (var item : msgDef.messageBody().messageElement()) {
-            if (item.messageDef() != null) { // process sub messages down below
+            if (item.messageDef() != null
+                    || item.enumDef() != null
+                    || item.DOC_COMMENT() != null) { // process sub messages down below
             } else if (item.oneof() != null) { // process one ofs
                 final var field = new OneOfField(item.oneof(), modelClassName, lookupHelper);
                 fields.add(field);

pbj-integration-tests/src/main/proto/enum_reserved.proto

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: Apache-2.0
+syntax = "proto3";
+package pbj.integ.test.enumeration.reserved;
+option java_multiple_files = true;
+
+enum PbjEnumReserved {
+  reserved 6;
+
+  READ_STREAM_UNKNOWN_TEST = 0;
+  READ_STREAM_INSUFFICIENT_BALANCE_TEST = 1;
+  READ_STREAM_SUCCESS_TEST = 2;
+  READ_STREAM_INVALID_START_BLOCK_NUMBER_TEST = 3;
+  READ_STREAM_INVALID_END_BLOCK_NUMBER_TEST = 4;
+  READ_STREAM_NOT_AVAILABLE_TEST = 5;
+}
+
+message MessageWithReservedEnum {
+  PbjEnumReserved the_enum_with_reserved_values = 1;
+}