Remove some rawtypes warning suppressions in ArrayDecoders

I think all these generics only change things at compile-time, not at runtime. So should be safe.

It's not a huge win; there's still some unchecked casts. But I was able to remove some unchecked casts, and some warning suppressions, so it's incrementally better.

PiperOrigin-RevId: 683793374

java/core/src/main/java/com/google/protobuf/ArrayDecoders.java

@@ -215,10 +215,10 @@ final class ArrayDecoders {
   }
 
   /** Decodes a message value. */
-  @SuppressWarnings({"unchecked", "rawtypes"})
-  static int decodeMessageField(
-      Schema schema, byte[] data, int position, int limit, Registers registers) throws IOException {
-    Object msg = schema.newInstance();
+  static <T> int decodeMessageField(
+      Schema<T> schema, byte[] data, int position, int limit, Registers registers)
+      throws IOException {
+    T msg = schema.newInstance();
     int offset = mergeMessageField(msg, schema, data, position, limit, registers);
     schema.makeImmutable(msg);
     registers.object1 = msg;
@@ -226,20 +226,19 @@ final class ArrayDecoders {
   }
 
   /** Decodes a group value. */
-  @SuppressWarnings({"unchecked", "rawtypes"})
-  static int decodeGroupField(
-      Schema schema, byte[] data, int position, int limit, int endGroup, Registers registers)
+  static <T> int decodeGroupField(
+      Schema<T> schema, byte[] data, int position, int limit, int endGroup, Registers registers)
       throws IOException {
-    Object msg = schema.newInstance();
+    T msg = schema.newInstance();
     int offset = mergeGroupField(msg, schema, data, position, limit, endGroup, registers);
     schema.makeImmutable(msg);
     registers.object1 = msg;
     return offset;
   }
 
-  @SuppressWarnings({"unchecked", "rawtypes"})
-  static int mergeMessageField(
-      Object msg, Schema schema, byte[] data, int position, int limit, Registers registers)
+  @SuppressWarnings("unchecked")
+  static <T> int mergeMessageField(
+      Object msg, Schema<T> schema, byte[] data, int position, int limit, Registers registers)
       throws IOException {
     int length = data[position++];
     if (length < 0) {
@@ -251,16 +250,16 @@ final class ArrayDecoders {
     }
     registers.recursionDepth++;
     checkRecursionLimit(registers.recursionDepth);
-    schema.mergeFrom(msg, data, position, position + length, registers);
+    schema.mergeFrom((T) msg, data, position, position + length, registers);
     registers.recursionDepth--;
     registers.object1 = msg;
     return position + length;
   }
 
-  @SuppressWarnings({"unchecked", "rawtypes"})
-  static int mergeGroupField(
+  @SuppressWarnings("unchecked")
+  static <T> int mergeGroupField(
       Object msg,
-      Schema schema,
+      Schema<T> schema,
       byte[] data,
       int position,
       int limit,
@@ -269,11 +268,11 @@ final class ArrayDecoders {
       throws IOException {
     // A group field must has a MessageSchema (the only other subclass of Schema is MessageSetSchema
     // and it can't be used in group fields).
-    final MessageSchema messageSchema = (MessageSchema) schema;
+    final MessageSchema<T> messageSchema = (MessageSchema<T>) schema;
     registers.recursionDepth++;
     checkRecursionLimit(registers.recursionDepth);
     final int endPosition =
-        messageSchema.parseMessage(msg, data, position, limit, endGroup, registers);
+        messageSchema.parseMessage((T) msg, data, position, limit, endGroup, registers);
     registers.recursionDepth--;
     registers.object1 = msg;
     return endPosition;
@@ -758,17 +757,15 @@ final class ArrayDecoders {
    *
    * @return The position of after read all groups
    */
-  @SuppressWarnings({"unchecked", "rawtypes"})
   static int decodeGroupList(
-      Schema schema,
+      Schema<?> schema,
       int tag,
       byte[] data,
       int position,
       int limit,
-      ProtobufList<?> list,
+      ProtobufList<Object> output,
       Registers registers)
       throws IOException {
-    final ProtobufList<Object> output = (ProtobufList<Object>) list;
     final int endgroup = (tag & ~0x7) | WireFormat.WIRETYPE_END_GROUP;
     position = decodeGroupField(schema, data, position, limit, endgroup, registers);
     output.add(registers.object1);
@@ -791,7 +788,7 @@ final class ArrayDecoders {
       Registers registers)
       throws IOException {
     final int number = tag >>> 3;
-    GeneratedMessageLite.GeneratedExtension extension =
+    GeneratedMessageLite.GeneratedExtension<?, ?> extension =
         registers.extensionRegistry.findLiteExtensionByNumber(defaultInstance, number);
     if (extension == null) {
       return decodeUnknownField(
@@ -972,7 +969,7 @@ final class ArrayDecoders {
           case GROUP:
             {
               final int endTag = (fieldNumber << 3) | WireFormat.WIRETYPE_END_GROUP;
-              final Schema fieldSchema =
+              final Schema<?> fieldSchema =
                   Protobuf.getInstance()
                       .schemaFor(extension.getMessageDefaultInstance().getClass());
               if (extension.isRepeated()) {
@@ -992,7 +989,7 @@ final class ArrayDecoders {
             }
           case MESSAGE:
             {
-              final Schema fieldSchema =
+              final Schema<?> fieldSchema =
                   Protobuf.getInstance()
                       .schemaFor(extension.getMessageDefaultInstance().getClass());
               if (extension.isRepeated()) {

java/core/src/main/java/com/google/protobuf/MessageSchema.java

@@ -3714,7 +3714,7 @@ final class MessageSchema<T> implements Schema<T> {
                   data,
                   position,
                   limit,
-                  list,
+                  (ProtobufList<Object>) list,
                   registers);
         }
         break;