rename upb_Message_WhichOneof to upb_Message_WhichOneofByDef

and introduce upb_Message_WhichOneof that returns a minitable field PiperOrigin-RevId: 631583174
Internal changes/optimizations
2024-05-09 17:07:08 -07:00 · 2024-05-09 15:54:16 -07:00 · 2024-05-09 15:18:31 -07:00 · 2024-05-09 22:09:21 +00:00 · 2024-05-09 14:57:53 -07:00 · 2024-05-09 14:42:05 -07:00
63 changed files with 2048 additions and 1138 deletions
--- a/bazel/system_python.bzl
+++ b/bazel/system_python.bzl
@ -0,0 +1,17 @@
+# Copyright (c) 2009-2021, Google LLC
+# All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Temporary alias to repository rule for using Python 3.x headers from the system."""
+
+load(
+    "//python/dist:system_python.bzl",
+    _system_python = "system_python",
+)
+
+# TODO: Temporary alias. This is deprecated and to be removed in a future
+# release. Users should now get system_python from protobuf_deps.bzl.
+system_python = _system_python
--- a/conformance/BUILD.bazel
+++ b/conformance/BUILD.bazel
@ -332,13 +332,14 @@ inline_sh_binary(
    ],
    cmd = """
        php -dextension=$(rootpath //php:extension) \\
-            -d include_path=conformance:src/google/protobuf \\
+            -d include_path=conformance:src/google/protobuf:editions/golden \\
            $(rootpath conformance_php.php)
    """,
    visibility = ["//php:__subpackages__"],
    deps = [
        ":conformance_php_proto",
        "//:test_messages_proto3_php_proto",
+        "//editions:test_messages_proto3_editions_php_proto",
    ],
 )

--- a/conformance/conformance_php.php
+++ b/conformance/conformance_php.php
@ -1,80 +1,134 @@
 <?php

-require_once("Conformance/WireFormat.php");
-require_once("Conformance/ConformanceResponse.php");
-require_once("Conformance/ConformanceRequest.php");
-require_once("Conformance/FailureSet.php");
-require_once("Conformance/JspbEncodingConfig.php");
-require_once("Conformance/TestCategory.php");
-require_once("Protobuf_test_messages/Proto3/ForeignMessage.php");
-require_once("Protobuf_test_messages/Proto3/ForeignEnum.php");
-require_once("Protobuf_test_messages/Proto3/TestAllTypesProto3.php");
-require_once("Protobuf_test_messages/Proto3/TestAllTypesProto3/AliasedEnum.php");
-require_once("Protobuf_test_messages/Proto3/TestAllTypesProto3/NestedMessage.php");
-require_once("Protobuf_test_messages/Proto3/TestAllTypesProto3/NestedEnum.php");
+require_once('Conformance/WireFormat.php');
+require_once('Conformance/ConformanceResponse.php');
+require_once('Conformance/ConformanceRequest.php');
+require_once('Conformance/FailureSet.php');
+require_once('Conformance/JspbEncodingConfig.php');
+require_once('Conformance/TestCategory.php');
+require_once('Protobuf_test_messages/Proto3/ForeignMessage.php');
+require_once('Protobuf_test_messages/Proto3/ForeignEnum.php');
+require_once('Protobuf_test_messages/Proto3/TestAllTypesProto3.php');
+require_once('Protobuf_test_messages/Proto3/TestAllTypesProto3/AliasedEnum.php');
+require_once('Protobuf_test_messages/Proto3/TestAllTypesProto3/NestedMessage.php');
+require_once('Protobuf_test_messages/Proto3/TestAllTypesProto3/NestedEnum.php');
+require_once('Protobuf_test_messages/Editions/Proto3/EnumOnlyProto3/PBBool.php');
+require_once('Protobuf_test_messages/Editions/Proto3/EnumOnlyProto3.php');
+require_once('Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3/NestedMessage.php');
+require_once('Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3/NestedEnum.php');
+require_once('Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3/AliasedEnum.php');
+require_once('Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3.php');
+require_once('Protobuf_test_messages/Editions/Proto3/NullHypothesisProto3.php');
+require_once('Protobuf_test_messages/Editions/Proto3/ForeignEnum.php');
+require_once('Protobuf_test_messages/Editions/Proto3/ForeignMessage.php');
+require_once('GPBMetadata/Conformance.php');
+require_once('GPBMetadata/TestMessagesProto3.php');
+require_once('GPBMetadata/TestMessagesProto3Editions.php');

-require_once("GPBMetadata/Conformance.php");
-require_once("GPBMetadata/TestMessagesProto3.php");
+use Conformance\ConformanceRequest;
+use Conformance\ConformanceResponse;
+use Conformance\TestCategory;
+use Conformance\WireFormat;
+use Protobuf_test_messages\Proto3\TestAllTypesProto3;
+use Protobuf_test_messages\Editions\Proto3\TestAllTypesProto3 as TestAllTypesProto3Editions;

-use  \Conformance\TestCategory;
-use  \Conformance\WireFormat;
-
-if (!ini_get("date.timezone")) {
-  ini_set("date.timezone", "UTC");
+if (!ini_get('date.timezone')) {
+    ini_set('date.timezone', 'UTC');
 }

 $test_count = 0;

 function doTest($request)
 {
-    $test_message = new \Protobuf_test_messages\Proto3\TestAllTypesProto3();
-    $response = new \Conformance\ConformanceResponse();
-    if ($request->getPayload() == "protobuf_payload") {
-      if ($request->getMessageType() == "conformance.FailureSet") {
-        $response->setProtobufPayload("");
-        return $response;
-      } elseif ($request->getMessageType() == "protobuf_test_messages.proto3.TestAllTypesProto3") {
-        try {
-          $test_message->mergeFromString($request->getProtobufPayload());
-        } catch (Exception $e) {
-          $response->setParseError($e->getMessage());
-          return $response;
-        }
-      } elseif ($request->getMessageType() == "protobuf_test_messages.proto2.TestAllTypesProto2") {
-        $response->setSkipped("PHP doesn't support proto2");
-        return $response;
-      } else {
-        trigger_error("Protobuf request doesn't have specific payload type", E_USER_ERROR);
-      }
-    } elseif ($request->getPayload() == "json_payload") {
-      $ignore_json_unknown =
-          ($request->getTestCategory() ==
-              TestCategory::JSON_IGNORE_UNKNOWN_PARSING_TEST);
-      try {
-          $test_message->mergeFromJsonString($request->getJsonPayload(),
-                                             $ignore_json_unknown);
-      } catch (Exception $e) {
-          $response->setParseError($e->getMessage());
-          return $response;
-      }
-	} elseif ($request->getPayload() == "text_payload") {
-		$response->setSkipped("PHP doesn't support text format yet");
-        return $response;
-	} else {
-      trigger_error("Request didn't have payload.", E_USER_ERROR);
+    $response = new ConformanceResponse();
+
+    switch ($request->getPayload()) {
+        case 'protobuf_payload':
+            switch ($request->getMessageType()) {
+                case 'protobuf_test_messages.proto3.TestAllTypesProto3':
+                    $test_message = new TestAllTypesProto3();
+                    break;
+                case 'protobuf_test_messages.editions.proto3.TestAllTypesProto3':
+                    $test_message = new TestAllTypesProto3Editions();
+                    break;
+                case 'conformance.FailureSet':
+                    $response->setProtobufPayload('');
+                    return $response;
+                case 'protobuf_test_messages.proto2.TestAllTypesProto2':
+                case 'protobuf_test_messages.editions.proto2.TestAllTypesProto2':
+                    $response->setSkipped('PHP doesn\'t support proto2');
+                    return $response;
+                case 'protobuf_test_messages.editions.TestAllTypesEdition2023':
+                    $response->setSkipped('PHP doesn\'t support editions-specific features yet');
+                    return $response;
+                case '':
+                    trigger_error(
+                        'Protobuf request doesn\'t have specific payload type',
+                        E_USER_ERROR
+                    );
+                default:
+                    trigger_error(sprintf(
+                        'Protobuf request doesn\'t support %s message type',
+                        $request->getMessageType(),
+                    ), E_USER_ERROR);
+            }
+
+            try {
+                $test_message->mergeFromString($request->getProtobufPayload());
+            } catch (Exception $e) {
+                $response->setParseError($e->getMessage());
+                return $response;
+            }
+            break;
+
+        case 'json_payload':
+            switch ($request->getMessageType()) {
+                case 'protobuf_test_messages.editions.proto3.TestAllTypesProto3':
+                    $test_message = new TestAllTypesProto3Editions();
+                    break;
+                case 'protobuf_test_messages.editions.proto2.TestAllTypesProto2':
+                    $response->setSkipped('PHP doesn\'t support proto2');
+                    return $response;
+                default:
+                    $test_message = new TestAllTypesProto3();
+            }
+
+            $ignore_json_unknown =
+                ($request->getTestCategory() == TestCategory::JSON_IGNORE_UNKNOWN_PARSING_TEST);
+            try {
+                $test_message->mergeFromJsonString(
+                    $request->getJsonPayload(),
+                    $ignore_json_unknown
+                );
+            } catch (Exception $e) {
+                $response->setParseError($e->getMessage());
+                return $response;
+            }
+            break;
+
+        case 'text_payload':
+            $response->setSkipped('PHP doesn\'t support text format yet');
+            return $response;
+        default:
+            trigger_error('Request didn\'t have payload.', E_USER_ERROR);
    }

-    if ($request->getRequestedOutputFormat() == WireFormat::UNSPECIFIED) {
-      trigger_error("Unspecified output format.", E_USER_ERROR);
-    } elseif ($request->getRequestedOutputFormat() == WireFormat::PROTOBUF) {
-      $response->setProtobufPayload($test_message->serializeToString());
-    } elseif ($request->getRequestedOutputFormat() == WireFormat::JSON) {
-      try {
-          $response->setJsonPayload($test_message->serializeToJsonString());
-      } catch (Exception $e) {
-          $response->setSerializeError($e->getMessage());
-          return $response;
-      }
+    switch ($request->getRequestedOutputFormat()) {
+        case WireFormat::TEXT_FORMAT:
+            $response->setSkipped('PHP doesn\'t support text format yet');
+            return $response;
+        case WireFormat::UNSPECIFIED:
+            trigger_error('Unspecified output format.', E_USER_ERROR);
+        case WireFormat::PROTOBUF:
+            $response->setProtobufPayload($test_message->serializeToString());
+            break;
+        case WireFormat::JSON:
+            try {
+                $response->setJsonPayload($test_message->serializeToJsonString());
+            } catch (Exception $e) {
+                $response->setSerializeError($e->getMessage());
+                return $response;
+            }
    }

    return $response;
@ -84,25 +138,25 @@ function doTestIO()
 {
    $length_bytes = fread(STDIN, 4);
    if (strlen($length_bytes) == 0) {
-      return false;   # EOF
+        return false;   # EOF
    } elseif (strlen($length_bytes) != 4) {
-      fwrite(STDERR, "I/O error\n");
-      return false;
+        fwrite(STDERR, "I/O error\n");
+        return false;
    }

-    $length = unpack("V", $length_bytes)[1];
+    $length = unpack('V', $length_bytes)[1];
    $serialized_request = fread(STDIN, $length);
    if (strlen($serialized_request) != $length) {
-      trigger_error("I/O error", E_USER_ERROR);
+        trigger_error('I/O error', E_USER_ERROR);
    }

-    $request = new \Conformance\ConformanceRequest();
+    $request = new ConformanceRequest();
    $request->mergeFromString($serialized_request);

    $response = doTest($request);

    $serialized_response = $response->serializeToString();
-    fwrite(STDOUT, pack("V", strlen($serialized_response)));
+    fwrite(STDOUT, pack('V', strlen($serialized_response)));
    fwrite(STDOUT, $serialized_response);

    $GLOBALS['test_count'] += 1;
@ -111,10 +165,10 @@ function doTestIO()
 }

 while(true){
-  if (!doTestIO()) {
-      fprintf(STDERR,
-             "conformance_php: received EOF from test runner " .
-             "after %d tests, exiting\n", $test_count);
-      exit;
-  }
+    if (!doTestIO()) {
+        fprintf(STDERR,
+            'conformance_php: received EOF from test runner ' .
+            "after %d tests, exiting\n", $test_count);
+        exit;
+    }
 }
--- a/conformance/text_format_conformance_suite.cc
+++ b/conformance/text_format_conformance_suite.cc
@ -440,13 +440,11 @@ void TextFormatConformanceTestSuiteImpl<MessageType>::RunAllTests() {
        absl::StrCat("FloatFieldLargerThanUint64", name_suffix), REQUIRED,
        absl::StrCat("optional_float: 18446744073709551616", suffix));
    // https://protobuf.dev/reference/protobuf/textformat-spec/#literals says
-    // "-0" is a valid float literal.
-    // TODO: Figure out if this should count as not setting
-    // presence or if -0 should be reflected back.
-    // RunValidTextFormatTestWithExpected(
-    //     absl::StrCat("FloatFieldNegativeZero", name_suffix), REQUIRED,
-    //     absl::StrCat("optional_float: -0", suffix),
-    //     "" /* implicit presence, so zero means unset*/);
+    // "-0" is a valid float literal. -0 should be considered not the same as 0
+    // when considering implicit presence, and so should round trip.
+    RunValidTextFormatTest(absl::StrCat("FloatFieldNegativeZero", name_suffix),
+                           REQUIRED,
+                           absl::StrCat("optional_float: -0", suffix));
    // https://protobuf.dev/reference/protobuf/textformat-spec/#literals says
    // ".123", "-.123", ".123e2" are a valid float literal.
    RunValidTextFormatTest(absl::StrCat("FloatFieldNoLeadingZero", name_suffix),
@ -502,6 +500,19 @@ void TextFormatConformanceTestSuiteImpl<MessageType>::RunAllTests() {
  RunValidTextFormatTestWithExpected(
      "DoubleFieldOverflowInfinityHugeExponent", REQUIRED,
      "optional_double: 1e18446744073709551616", "optional_double: inf");
+  RunValidTextFormatTestWithExpected(
+      "DoubleFieldLargeNegativeExponentParsesAsZero", REQUIRED,
+      "optional_double: 1e-18446744073709551616", "");
+  RunValidTextFormatTestWithExpected(
+      "NegDoubleFieldLargeNegativeExponentParsesAsNegZero", REQUIRED,
+      "optional_double: -1e-18446744073709551616", "optional_double: -0");
+
+  RunValidTextFormatTestWithExpected(
+      "FloatFieldLargeNegativeExponentParsesAsZero", REQUIRED,
+      "optional_float: 1e-50", "");
+  RunValidTextFormatTestWithExpected(
+      "NegFloatFieldLargeNegativeExponentParsesAsNegZero", REQUIRED,
+      "optional_float: -1e-50", "optional_float: -0");

  // String literals x {Strings, Bytes}
  for (const auto& field_type : std::vector<std::string>{"String", "Bytes"}) {
--- a/conformance/text_format_failure_list_php.txt
+++ b/conformance/text_format_failure_list_php.txt
@ -1,8 +0,0 @@
-Recommended.Proto3.ProtobufInput.GroupUnknownFields_Drop.TextFormatOutput
-Recommended.Proto3.ProtobufInput.GroupUnknownFields_Print.TextFormatOutput
-Recommended.Proto3.ProtobufInput.MessageUnknownFields_Drop.TextFormatOutput
-Recommended.Proto3.ProtobufInput.MessageUnknownFields_Print.TextFormatOutput
-Recommended.Proto3.ProtobufInput.RepeatedUnknownFields_Drop.TextFormatOutput
-Recommended.Proto3.ProtobufInput.RepeatedUnknownFields_Print.TextFormatOutput
-Recommended.Proto3.ProtobufInput.ScalarUnknownFields_Drop.TextFormatOutput
-Recommended.Proto3.ProtobufInput.ScalarUnknownFields_Print.TextFormatOutput
--- a/conformance/text_format_failure_list_python.txt
+++ b/conformance/text_format_failure_list_python.txt
@ -77,3 +77,23 @@ Required.Proto3.TextFormatInput.StringLiteralBasicEscapesBytes.ProtobufOutput
 Required.Proto3.TextFormatInput.StringLiteralBasicEscapesBytes.TextFormatOutput
 Required.Proto3.TextFormatInput.StringLiteralBasicEscapesString.ProtobufOutput
 Required.Proto3.TextFormatInput.StringLiteralBasicEscapesString.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_F.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_F.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_f.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_f.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.NegDoubleFieldLargeNegativeExponentParsesAsNegZero.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.NegDoubleFieldLargeNegativeExponentParsesAsNegZero.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.NegFloatFieldLargeNegativeExponentParsesAsNegZero.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.NegFloatFieldLargeNegativeExponentParsesAsNegZero.TextFormatOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero.ProtobufOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero.TextFormatOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_F.ProtobufOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_F.TextFormatOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_f.ProtobufOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_f.TextFormatOutput
+Required.Proto3.TextFormatInput.NegDoubleFieldLargeNegativeExponentParsesAsNegZero.ProtobufOutput
+Required.Proto3.TextFormatInput.NegDoubleFieldLargeNegativeExponentParsesAsNegZero.TextFormatOutput
+Required.Proto3.TextFormatInput.NegFloatFieldLargeNegativeExponentParsesAsNegZero.ProtobufOutput
+Required.Proto3.TextFormatInput.NegFloatFieldLargeNegativeExponentParsesAsNegZero.TextFormatOutput
--- a/conformance/text_format_failure_list_python_cpp.txt
+++ b/conformance/text_format_failure_list_python_cpp.txt
@ -28,6 +28,8 @@ Required.Editions_Proto3.TextFormatInput.FloatFieldWithVeryPreciseNumber_F.Proto
 Required.Editions_Proto3.TextFormatInput.FloatFieldWithVeryPreciseNumber_F.TextFormatOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldZero_F.ProtobufOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldZero_F.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_F.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_F.TextFormatOutput
 Required.Editions_Proto3.TextFormatInput.StringLiteralBasicEscapesBytes.ProtobufOutput
 Required.Editions_Proto3.TextFormatInput.StringLiteralBasicEscapesBytes.TextFormatOutput
 Required.Editions_Proto3.TextFormatInput.StringLiteralBasicEscapesString.ProtobufOutput
@ -62,6 +64,8 @@ Required.Proto3.TextFormatInput.FloatFieldWithVeryPreciseNumber_F.ProtobufOutput
 Required.Proto3.TextFormatInput.FloatFieldWithVeryPreciseNumber_F.TextFormatOutput
 Required.Proto3.TextFormatInput.FloatFieldZero_F.ProtobufOutput
 Required.Proto3.TextFormatInput.FloatFieldZero_F.TextFormatOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_F.ProtobufOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_F.TextFormatOutput
 Required.Proto3.TextFormatInput.StringLiteralBasicEscapesBytes.ProtobufOutput
 Required.Proto3.TextFormatInput.StringLiteralBasicEscapesBytes.TextFormatOutput
 Required.Proto3.TextFormatInput.StringLiteralBasicEscapesString.ProtobufOutput
--- a/conformance/text_format_failure_list_python_upb.txt
+++ b/conformance/text_format_failure_list_python_upb.txt
@ -15,6 +15,8 @@ Required.Editions_Proto3.TextFormatInput.FloatFieldNegative_F.ProtobufOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldNegative_F.TextFormatOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeNoLeadingZero_F.ProtobufOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeNoLeadingZero_F.TextFormatOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_F.ProtobufOutput
+Required.Editions_Proto3.TextFormatInput.FloatFieldNegativeZero_F.TextFormatOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldNoLeadingZero_F.ProtobufOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldNoLeadingZero_F.TextFormatOutput
 Required.Editions_Proto3.TextFormatInput.FloatFieldNoLeadingZeroWithExponent_F.ProtobufOutput
@ -49,6 +51,8 @@ Required.Proto3.TextFormatInput.FloatFieldNegative_F.ProtobufOutput
 Required.Proto3.TextFormatInput.FloatFieldNegative_F.TextFormatOutput
 Required.Proto3.TextFormatInput.FloatFieldNegativeNoLeadingZero_F.ProtobufOutput
 Required.Proto3.TextFormatInput.FloatFieldNegativeNoLeadingZero_F.TextFormatOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_F.ProtobufOutput
+Required.Proto3.TextFormatInput.FloatFieldNegativeZero_F.TextFormatOutput
 Required.Proto3.TextFormatInput.FloatFieldNoLeadingZero_F.ProtobufOutput
 Required.Proto3.TextFormatInput.FloatFieldNoLeadingZero_F.TextFormatOutput
 Required.Proto3.TextFormatInput.FloatFieldNoLeadingZeroWithExponent_F.ProtobufOutput
--- a/editions/BUILD
+++ b/editions/BUILD
@ -1,5 +1,5 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
-load("//:protobuf.bzl", "internal_objc_proto_library", "internal_py_proto_library")
+load("//:protobuf.bzl", "internal_objc_proto_library", "internal_php_proto_library", "internal_py_proto_library")
 load("//bazel:cc_proto_library.bzl", "cc_proto_library")
 load("//bazel:upb_proto_library.bzl", "upb_c_proto_library", "upb_proto_reflection_library")
 load(":defaults.bzl", "compile_edition_defaults", "embed_edition_defaults")
@ -236,6 +236,31 @@ java_lite_proto_library(
    deps = [":test_messages_proto3_editions_proto"],
 )

+internal_php_proto_library(
+    name = "test_messages_proto3_editions_php_proto",
+    testonly = 1,
+    srcs = ["golden/test_messages_proto3_editions.proto"],
+    outs = [
+        "GPBMetadata/TestMessagesProto3Editions.php",
+        "Protobuf_test_messages/Editions/Proto3/EnumOnlyProto3.php",
+        "Protobuf_test_messages/Editions/Proto3/EnumOnlyProto3/PBBool.php",
+        "Protobuf_test_messages/Editions/Proto3/ForeignEnum.php",
+        "Protobuf_test_messages/Editions/Proto3/ForeignMessage.php",
+        "Protobuf_test_messages/Editions/Proto3/NullHypothesisProto3.php",
+        "Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3.php",
+        "Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3/AliasedEnum.php",
+        "Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3/NestedEnum.php",
+        "Protobuf_test_messages/Editions/Proto3/TestAllTypesProto3/NestedMessage.php",
+    ],
+    enable_editions = True,
+    includes = [
+        "golden",
+        "src",
+    ],
+    proto_deps = ["//:well_known_protos"],
+    visibility = ["//conformance:__pkg__"],
+)
+
 internal_py_proto_library(
    name = "test_messages_proto3_editions_py_pb2",
    testonly = True,
--- a/java/core/BUILD.bazel
+++ b/java/core/BUILD.bazel
@ -60,6 +60,8 @@ LITE_SRCS = [
    "src/main/java/com/google/protobuf/LazyStringArrayList.java",
    "src/main/java/com/google/protobuf/LazyStringList.java",
    "src/main/java/com/google/protobuf/ListFieldSchema.java",
+    "src/main/java/com/google/protobuf/ListFieldSchemaLite.java",
+    "src/main/java/com/google/protobuf/ListFieldSchemas.java",
    "src/main/java/com/google/protobuf/LongArrayList.java",
    "src/main/java/com/google/protobuf/ManifestSchemaFactory.java",
    "src/main/java/com/google/protobuf/MapEntryLite.java",
--- a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
@ -2690,6 +2690,9 @@ public abstract class CodedInputStream {
        throw InvalidProtocolBufferException.negativeSize();
      }
      byteLimit += totalBytesRetired + pos;
+      if (byteLimit < 0) {
+        throw InvalidProtocolBufferException.parseFailure();
+      }
      final int oldLimit = currentLimit;
      if (byteLimit > oldLimit) {
        throw InvalidProtocolBufferException.truncatedMessage();
--- a/java/core/src/main/java/com/google/protobuf/ExtensionSchemas.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionSchemas.java
@ -31,4 +31,6 @@ final class ExtensionSchemas {
    }
    return FULL_SCHEMA;
  }
+
+  private ExtensionSchemas() {}
 }
--- a/java/core/src/main/java/com/google/protobuf/ListFieldSchema.java
+++ b/java/core/src/main/java/com/google/protobuf/ListFieldSchema.java
@ -7,162 +7,17 @@

 package com.google.protobuf;

-import com.google.protobuf.Internal.ProtobufList;
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;

 /**
 * Utility class that aids in properly manipulating list fields for either the lite or full runtime.
 */
@CheckReturnValue
-abstract class ListFieldSchema {
-  // Disallow construction.
-  private ListFieldSchema() {}
+interface ListFieldSchema {

-  private static final ListFieldSchema FULL_INSTANCE = new ListFieldSchemaFull();
-  private static final ListFieldSchema LITE_INSTANCE = new ListFieldSchemaLite();
+  <L> List<L> mutableListAt(Object msg, long offset);

-  abstract <L> List<L> mutableListAt(Object msg, long offset);
+  void makeImmutableListAt(Object msg, long offset);

-  abstract void makeImmutableListAt(Object msg, long offset);
-
-  abstract <L> void mergeListsAt(Object msg, Object otherMsg, long offset);
-
-  static ListFieldSchema full() {
-    return FULL_INSTANCE;
-  }
-
-  static ListFieldSchema lite() {
-    return LITE_INSTANCE;
-  }
-
-  /** Implementation for the full runtime. */
-  private static final class ListFieldSchemaFull extends ListFieldSchema {
-
-    private static final Class<?> UNMODIFIABLE_LIST_CLASS =
-        Collections.unmodifiableList(Collections.emptyList()).getClass();
-
-    @Override
-    <L> List<L> mutableListAt(Object message, long offset) {
-      return mutableListAt(message, offset, AbstractProtobufList.DEFAULT_CAPACITY);
-    }
-
-    @Override
-    void makeImmutableListAt(Object message, long offset) {
-      List<?> list = (List<?>) UnsafeUtil.getObject(message, offset);
-      Object immutable = null;
-      if (list instanceof LazyStringList) {
-        immutable = ((LazyStringList) list).getUnmodifiableView();
-      } else if (UNMODIFIABLE_LIST_CLASS.isAssignableFrom(list.getClass())) {
-        // already immutable
-        return;
-      } else if (list instanceof PrimitiveNonBoxingCollection && list instanceof ProtobufList) {
-        if (((ProtobufList<?>) list).isModifiable()) {
-          ((ProtobufList<?>) list).makeImmutable();
-        }
-        return;
-      } else {
-        immutable = Collections.unmodifiableList((List<?>) list);
-      }
-      UnsafeUtil.putObject(message, offset, immutable);
-    }
-
-    @SuppressWarnings("unchecked")
-    private static <L> List<L> mutableListAt(Object message, long offset, int additionalCapacity) {
-      List<L> list = getList(message, offset);
-      if (list.isEmpty()) {
-        if (list instanceof LazyStringList) {
-          list = (List<L>) new LazyStringArrayList(additionalCapacity);
-        } else if (list instanceof PrimitiveNonBoxingCollection && list instanceof ProtobufList) {
-          list = ((ProtobufList<L>) list).mutableCopyWithCapacity(additionalCapacity);
-        } else {
-          list = new ArrayList<L>(additionalCapacity);
-        }
-        UnsafeUtil.putObject(message, offset, list);
-      } else if (UNMODIFIABLE_LIST_CLASS.isAssignableFrom(list.getClass())) {
-        ArrayList<L> newList = new ArrayList<L>(list.size() + additionalCapacity);
-        newList.addAll(list);
-        list = newList;
-        UnsafeUtil.putObject(message, offset, list);
-      } else if (list instanceof UnmodifiableLazyStringList) {
-        LazyStringArrayList newList = new LazyStringArrayList(list.size() + additionalCapacity);
-        newList.addAll((UnmodifiableLazyStringList) list);
-        list = (List<L>) newList;
-        UnsafeUtil.putObject(message, offset, list);
-      } else if (list instanceof PrimitiveNonBoxingCollection
-          && list instanceof ProtobufList
-          && !((ProtobufList<L>) list).isModifiable()) {
-        list = ((ProtobufList<L>) list).mutableCopyWithCapacity(list.size() + additionalCapacity);
-        UnsafeUtil.putObject(message, offset, list);
-      }
-      return list;
-    }
-
-    @Override
-    <E> void mergeListsAt(Object msg, Object otherMsg, long offset) {
-      List<E> other = getList(otherMsg, offset);
-      List<E> mine = mutableListAt(msg, offset, other.size());
-
-      int size = mine.size();
-      int otherSize = other.size();
-      if (size > 0 && otherSize > 0) {
-        mine.addAll(other);
-      }
-
-      List<E> merged = size > 0 ? mine : other;
-      UnsafeUtil.putObject(msg, offset, merged);
-    }
-
-    @SuppressWarnings("unchecked")
-    static <E> List<E> getList(Object message, long offset) {
-      return (List<E>) UnsafeUtil.getObject(message, offset);
-    }
-  }
-
-  /** Implementation for the lite runtime. */
-  private static final class ListFieldSchemaLite extends ListFieldSchema {
-
-    @Override
-    <L> List<L> mutableListAt(Object message, long offset) {
-      ProtobufList<L> list = getProtobufList(message, offset);
-      if (!list.isModifiable()) {
-        int size = list.size();
-        list =
-            list.mutableCopyWithCapacity(
-                size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
-        UnsafeUtil.putObject(message, offset, list);
-      }
-      return list;
-    }
-
-    @Override
-    void makeImmutableListAt(Object message, long offset) {
-      ProtobufList<?> list = getProtobufList(message, offset);
-      list.makeImmutable();
-    }
-
-    @Override
-    <E> void mergeListsAt(Object msg, Object otherMsg, long offset) {
-      ProtobufList<E> mine = getProtobufList(msg, offset);
-      ProtobufList<E> other = getProtobufList(otherMsg, offset);
-
-      int size = mine.size();
-      int otherSize = other.size();
-      if (size > 0 && otherSize > 0) {
-        if (!mine.isModifiable()) {
-          mine = mine.mutableCopyWithCapacity(size + otherSize);
-        }
-        mine.addAll(other);
-      }
-
-      ProtobufList<E> merged = size > 0 ? mine : other;
-      UnsafeUtil.putObject(msg, offset, merged);
-    }
-
-    @SuppressWarnings("unchecked")
-    static <E> ProtobufList<E> getProtobufList(Object message, long offset) {
-      return (ProtobufList<E>) UnsafeUtil.getObject(message, offset);
-    }
-  }
+  <L> void mergeListsAt(Object msg, Object otherMsg, long offset);
 }
--- a/java/core/src/main/java/com/google/protobuf/ListFieldSchemaFull.java
+++ b/java/core/src/main/java/com/google/protobuf/ListFieldSchemaFull.java
@ -0,0 +1,99 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+package com.google.protobuf;
+
+import com.google.protobuf.Internal.ProtobufList;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Utility class that aids in properly manipulating list fields for either the lite or full runtime.
+ */
+@CheckReturnValue
+final class ListFieldSchemaFull implements ListFieldSchema {
+
+  private static final Class<?> UNMODIFIABLE_LIST_CLASS =
+      Collections.unmodifiableList(Collections.emptyList()).getClass();
+
+  @Override
+  public <L> List<L> mutableListAt(Object message, long offset) {
+    return mutableListAt(message, offset, AbstractProtobufList.DEFAULT_CAPACITY);
+  }
+
+  @SuppressWarnings("unchecked")
+  private static <L> List<L> mutableListAt(Object message, long offset, int additionalCapacity) {
+    List<L> list = getList(message, offset);
+    if (list.isEmpty()) {
+      if (list instanceof LazyStringList) {
+        list = (List<L>) new LazyStringArrayList(additionalCapacity);
+      } else if (list instanceof PrimitiveNonBoxingCollection && list instanceof ProtobufList) {
+        list = ((ProtobufList<L>) list).mutableCopyWithCapacity(additionalCapacity);
+      } else {
+        list = new ArrayList<L>(additionalCapacity);
+      }
+      UnsafeUtil.putObject(message, offset, list);
+    } else if (UNMODIFIABLE_LIST_CLASS.isAssignableFrom(list.getClass())) {
+      ArrayList<L> newList = new ArrayList<L>(list.size() + additionalCapacity);
+      newList.addAll(list);
+      list = newList;
+      UnsafeUtil.putObject(message, offset, list);
+    } else if (list instanceof UnmodifiableLazyStringList) {
+      LazyStringArrayList newList = new LazyStringArrayList(list.size() + additionalCapacity);
+      newList.addAll((UnmodifiableLazyStringList) list);
+      list = (List<L>) newList;
+      UnsafeUtil.putObject(message, offset, list);
+    } else if (list instanceof PrimitiveNonBoxingCollection
+        && list instanceof ProtobufList
+        && !((ProtobufList<L>) list).isModifiable()) {
+      list = ((ProtobufList<L>) list).mutableCopyWithCapacity(list.size() + additionalCapacity);
+      UnsafeUtil.putObject(message, offset, list);
+    }
+    return list;
+  }
+
+  @Override
+  public void makeImmutableListAt(Object message, long offset) {
+    List<?> list = (List<?>) UnsafeUtil.getObject(message, offset);
+    Object immutable = null;
+    if (list instanceof LazyStringList) {
+      immutable = ((LazyStringList) list).getUnmodifiableView();
+    } else if (UNMODIFIABLE_LIST_CLASS.isAssignableFrom(list.getClass())) {
+      // already immutable
+      return;
+    } else if (list instanceof PrimitiveNonBoxingCollection && list instanceof ProtobufList) {
+      if (((ProtobufList<?>) list).isModifiable()) {
+        ((ProtobufList<?>) list).makeImmutable();
+      }
+      return;
+    } else {
+      immutable = Collections.unmodifiableList((List<?>) list);
+    }
+    UnsafeUtil.putObject(message, offset, immutable);
+  }
+
+  @Override
+  public <E> void mergeListsAt(Object msg, Object otherMsg, long offset) {
+    List<E> other = getList(otherMsg, offset);
+    List<E> mine = mutableListAt(msg, offset, other.size());
+
+    int size = mine.size();
+    int otherSize = other.size();
+    if (size > 0 && otherSize > 0) {
+      mine.addAll(other);
+    }
+
+    List<E> merged = size > 0 ? mine : other;
+    UnsafeUtil.putObject(msg, offset, merged);
+  }
+
+  @SuppressWarnings("unchecked")
+  static <E> List<E> getList(Object message, long offset) {
+    return (List<E>) UnsafeUtil.getObject(message, offset);
+  }
+}
--- a/java/core/src/main/java/com/google/protobuf/ListFieldSchemaLite.java
+++ b/java/core/src/main/java/com/google/protobuf/ListFieldSchemaLite.java
@ -0,0 +1,59 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+package com.google.protobuf;
+
+import com.google.protobuf.Internal.ProtobufList;
+import java.util.List;
+
+/**
+ * Utility class that aids in properly manipulating list fields for either the lite or full runtime.
+ */
+final class ListFieldSchemaLite implements ListFieldSchema {
+
+  @Override
+  public <L> List<L> mutableListAt(Object message, long offset) {
+    ProtobufList<L> list = getProtobufList(message, offset);
+    if (!list.isModifiable()) {
+      int size = list.size();
+      list =
+          list.mutableCopyWithCapacity(
+              size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+      UnsafeUtil.putObject(message, offset, list);
+    }
+    return list;
+  }
+
+  @Override
+  public void makeImmutableListAt(Object message, long offset) {
+    ProtobufList<?> list = getProtobufList(message, offset);
+    list.makeImmutable();
+  }
+
+  @Override
+  public <E> void mergeListsAt(Object msg, Object otherMsg, long offset) {
+    ProtobufList<E> mine = getProtobufList(msg, offset);
+    ProtobufList<E> other = getProtobufList(otherMsg, offset);
+
+    int size = mine.size();
+    int otherSize = other.size();
+    if (size > 0 && otherSize > 0) {
+      if (!mine.isModifiable()) {
+        mine = mine.mutableCopyWithCapacity(size + otherSize);
+      }
+      mine.addAll(other);
+    }
+
+    ProtobufList<E> merged = size > 0 ? mine : other;
+    UnsafeUtil.putObject(msg, offset, merged);
+  }
+
+  @SuppressWarnings("unchecked")
+  static <E> ProtobufList<E> getProtobufList(Object message, long offset) {
+    return (ProtobufList<E>) UnsafeUtil.getObject(message, offset);
+  }
+}
--- a/java/core/src/main/java/com/google/protobuf/ListFieldSchemas.java
+++ b/java/core/src/main/java/com/google/protobuf/ListFieldSchemas.java
@ -0,0 +1,33 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+package com.google.protobuf;
+
+@CheckReturnValue
+final class ListFieldSchemas {
+  private static final ListFieldSchema FULL_SCHEMA = loadSchemaForFullRuntime();
+  private static final ListFieldSchema LITE_SCHEMA = new ListFieldSchemaLite();
+
+  static ListFieldSchema full() {
+    return FULL_SCHEMA;
+  }
+
+  static ListFieldSchema lite() {
+    return LITE_SCHEMA;
+  }
+
+  private static ListFieldSchema loadSchemaForFullRuntime() {
+    try {
+      Class<?> clazz = Class.forName("com.google.protobuf.ListFieldSchemaFull");
+      return (ListFieldSchema) clazz.getDeclaredConstructor().newInstance();
+    } catch (Exception e) {
+      return null;
+    }
+  }
+
+  private ListFieldSchemas() {}
+}
--- a/java/core/src/main/java/com/google/protobuf/ManifestSchemaFactory.java
+++ b/java/core/src/main/java/com/google/protobuf/ManifestSchemaFactory.java
@ -34,57 +34,37 @@ final class ManifestSchemaFactory implements SchemaFactory {

    // MessageSet has a special schema.
    if (messageInfo.isMessageSetWireFormat()) {
-      if (GeneratedMessageLite.class.isAssignableFrom(messageType)) {
-        return MessageSetSchema.newSchema(
-            SchemaUtil.unknownFieldSetLiteSchema(),
-            ExtensionSchemas.lite(),
-            messageInfo.getDefaultInstance());
-      }
-      return MessageSetSchema.newSchema(
-          SchemaUtil.unknownFieldSetFullSchema(),
-          ExtensionSchemas.full(),
-          messageInfo.getDefaultInstance());
+      return useLiteRuntime(messageType)
+          ? MessageSetSchema.newSchema(
+              SchemaUtil.unknownFieldSetLiteSchema(),
+              ExtensionSchemas.lite(),
+              messageInfo.getDefaultInstance())
+          : MessageSetSchema.newSchema(
+              SchemaUtil.unknownFieldSetFullSchema(),
+              ExtensionSchemas.full(),
+              messageInfo.getDefaultInstance());
    }

    return newSchema(messageType, messageInfo);
  }

  private static <T> Schema<T> newSchema(Class<T> messageType, MessageInfo messageInfo) {
-    if (GeneratedMessageLite.class.isAssignableFrom(messageType)) {
-      return allowExtensions(messageInfo)
-          ? MessageSchema.newSchema(
-              messageType,
-              messageInfo,
-              NewInstanceSchemas.lite(),
-              ListFieldSchema.lite(),
-              SchemaUtil.unknownFieldSetLiteSchema(),
-              ExtensionSchemas.lite(),
-              MapFieldSchemas.lite())
-          : MessageSchema.newSchema(
-              messageType,
-              messageInfo,
-              NewInstanceSchemas.lite(),
-              ListFieldSchema.lite(),
-              SchemaUtil.unknownFieldSetLiteSchema(),
-              /* extensionSchema= */ null,
-              MapFieldSchemas.lite());
-    }
-    return allowExtensions(messageInfo)
+    return useLiteRuntime(messageType)
        ? MessageSchema.newSchema(
            messageType,
            messageInfo,
-            NewInstanceSchemas.full(),
-            ListFieldSchema.full(),
-            SchemaUtil.unknownFieldSetFullSchema(),
-            ExtensionSchemas.full(),
-            MapFieldSchemas.full())
+            NewInstanceSchemas.lite(),
+            ListFieldSchemas.lite(),
+            SchemaUtil.unknownFieldSetLiteSchema(),
+            allowExtensions(messageInfo) ? ExtensionSchemas.lite() : null,
+            MapFieldSchemas.lite())
        : MessageSchema.newSchema(
            messageType,
            messageInfo,
            NewInstanceSchemas.full(),
-            ListFieldSchema.full(),
+            ListFieldSchemas.full(),
            SchemaUtil.unknownFieldSetFullSchema(),
-            /* extensionSchema= */ null,
+            allowExtensions(messageInfo) ? ExtensionSchemas.full() : null,
            MapFieldSchemas.full());
  }

@ -152,4 +132,8 @@ final class ManifestSchemaFactory implements SchemaFactory {
      return EMPTY_FACTORY;
    }
  }
+
+  private static boolean useLiteRuntime(Class<?> messageType) {
+    return GeneratedMessageLite.class.isAssignableFrom(messageType);
+  }
 }
--- a/java/core/src/main/java/com/google/protobuf/MapFieldSchemaFull.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldSchemaFull.java
@ -10,7 +10,7 @@ package com.google.protobuf;
 import com.google.protobuf.MapEntryLite.Metadata;
 import java.util.Map;

-class MapFieldSchemaFull implements MapFieldSchema {
+final class MapFieldSchemaFull implements MapFieldSchema {
  @Override
  public Map<?, ?> forMutableMapData(Object mapField) {
    return ((MapField<?, ?>) mapField).getMutableMap();
--- a/java/core/src/main/java/com/google/protobuf/MapFieldSchemaLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldSchemaLite.java
@ -11,7 +11,7 @@ import com.google.protobuf.MapEntryLite.Metadata;
 import java.util.Map;

@CheckReturnValue
-class MapFieldSchemaLite implements MapFieldSchema {
+final class MapFieldSchemaLite implements MapFieldSchema {

  @Override
  public Map<?, ?> forMutableMapData(Object mapField) {
--- a/java/core/src/main/java/com/google/protobuf/MapFieldSchemas.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldSchemas.java
@ -28,4 +28,6 @@ final class MapFieldSchemas {
      return null;
    }
  }
+
+  private MapFieldSchemas() {}
 }
--- a/java/core/src/main/java/com/google/protobuf/NewInstanceSchemas.java
+++ b/java/core/src/main/java/com/google/protobuf/NewInstanceSchemas.java
@ -28,4 +28,6 @@ final class NewInstanceSchemas {
      return null;
    }
  }
+
+  private NewInstanceSchemas() {}
 }
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml
@ -139,6 +139,8 @@
                    <include>LazyStringArrayList.java</include>
                    <include>LazyStringList.java</include>
                    <include>ListFieldSchema.java</include>
+                    <include>ListFieldSchemaLite.java</include>
+                    <include>ListFieldSchemas.java</include>
                    <include>LongArrayList.java</include>
                    <include>ManifestSchemaFactory.java</include>
                    <include>MapEntryLite.java</include>
--- a/php/BUILD.bazel
+++ b/php/BUILD.bazel
@ -64,6 +64,7 @@ genrule(
 conformance_test(
    name = "conformance_test",
    failure_list = "//conformance:failure_list_php.txt",
+    maximum_edition = "2023",
    target_compatible_with = select({
        "@platforms//os:osx": ["@platforms//:incompatible"],
        "//conditions:default": [],
@ -75,6 +76,7 @@ conformance_test(
 conformance_test(
    name = "conformance_test_c",
    failure_list = "//conformance:failure_list_php_c.txt",
+    maximum_edition = "2023",
    target_compatible_with = select({
        "@platforms//os:osx": [],
        "//conditions:default": ["@platforms//:incompatible"],
--- a/php/ext/google/protobuf/php-upb.c
+++ b/php/ext/google/protobuf/php-upb.c
@ -6158,7 +6158,7 @@ upb_Message* _upb_Message_Copy(upb_Message* dst, const upb_Message* src,
              return NULL;
            }
            UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
-            (dst, mini_table, field,
+            (dst, field,
             UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(dst_sub_message,
                                                     is_empty));
          }
--- a/php/ext/google/protobuf/php-upb.h
+++ b/php/ext/google/protobuf/php-upb.h
@ -413,113 +413,6 @@ void upb_Status_VAppendErrorFormat(upb_Status* status, const char* fmt,
 #ifndef UPB_MESSAGE_ACCESSORS_H_
 #define UPB_MESSAGE_ACCESSORS_H_

-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-
-#ifndef UPB_BASE_DESCRIPTOR_CONSTANTS_H_
-#define UPB_BASE_DESCRIPTOR_CONSTANTS_H_
-
-// Must be last.
-
-// The types a field can have. Note that this list is not identical to the
-// types defined in descriptor.proto, which gives INT32 and SINT32 separate
-// types (we distinguish the two with the "integer encoding" enum below).
-// This enum is an internal convenience only and has no meaning outside of upb.
-typedef enum {
-  kUpb_CType_Bool = 1,
-  kUpb_CType_Float = 2,
-  kUpb_CType_Int32 = 3,
-  kUpb_CType_UInt32 = 4,
-  kUpb_CType_Enum = 5,  // Enum values are int32. TODO: rename
-  kUpb_CType_Message = 6,
-  kUpb_CType_Double = 7,
-  kUpb_CType_Int64 = 8,
-  kUpb_CType_UInt64 = 9,
-  kUpb_CType_String = 10,
-  kUpb_CType_Bytes = 11
-} upb_CType;
-
-// The repeated-ness of each field; this matches descriptor.proto.
-typedef enum {
-  kUpb_Label_Optional = 1,
-  kUpb_Label_Required = 2,
-  kUpb_Label_Repeated = 3
-} upb_Label;
-
-// Descriptor types, as defined in descriptor.proto.
-typedef enum {
-  kUpb_FieldType_Double = 1,
-  kUpb_FieldType_Float = 2,
-  kUpb_FieldType_Int64 = 3,
-  kUpb_FieldType_UInt64 = 4,
-  kUpb_FieldType_Int32 = 5,
-  kUpb_FieldType_Fixed64 = 6,
-  kUpb_FieldType_Fixed32 = 7,
-  kUpb_FieldType_Bool = 8,
-  kUpb_FieldType_String = 9,
-  kUpb_FieldType_Group = 10,
-  kUpb_FieldType_Message = 11,
-  kUpb_FieldType_Bytes = 12,
-  kUpb_FieldType_UInt32 = 13,
-  kUpb_FieldType_Enum = 14,
-  kUpb_FieldType_SFixed32 = 15,
-  kUpb_FieldType_SFixed64 = 16,
-  kUpb_FieldType_SInt32 = 17,
-  kUpb_FieldType_SInt64 = 18,
-} upb_FieldType;
-
-#define kUpb_FieldType_SizeOf 19
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-// Convert from upb_FieldType to upb_CType
-UPB_INLINE upb_CType upb_FieldType_CType(upb_FieldType field_type) {
-  static const upb_CType c_type[] = {
-      kUpb_CType_Double,   // kUpb_FieldType_Double
-      kUpb_CType_Float,    // kUpb_FieldType_Float
-      kUpb_CType_Int64,    // kUpb_FieldType_Int64
-      kUpb_CType_UInt64,   // kUpb_FieldType_UInt64
-      kUpb_CType_Int32,    // kUpb_FieldType_Int32
-      kUpb_CType_UInt64,   // kUpb_FieldType_Fixed64
-      kUpb_CType_UInt32,   // kUpb_FieldType_Fixed32
-      kUpb_CType_Bool,     // kUpb_FieldType_Bool
-      kUpb_CType_String,   // kUpb_FieldType_String
-      kUpb_CType_Message,  // kUpb_FieldType_Group
-      kUpb_CType_Message,  // kUpb_FieldType_Message
-      kUpb_CType_Bytes,    // kUpb_FieldType_Bytes
-      kUpb_CType_UInt32,   // kUpb_FieldType_UInt32
-      kUpb_CType_Enum,     // kUpb_FieldType_Enum
-      kUpb_CType_Int32,    // kUpb_FieldType_SFixed32
-      kUpb_CType_Int64,    // kUpb_FieldType_SFixed64
-      kUpb_CType_Int32,    // kUpb_FieldType_SInt32
-      kUpb_CType_Int64,    // kUpb_FieldType_SInt64
-  };
-
-  // -1 here because the enum is one-based but the table is zero-based.
-  return c_type[field_type - 1];
-}
-
-UPB_INLINE bool upb_FieldType_IsPackable(upb_FieldType field_type) {
-  // clang-format off
-  const unsigned kUnpackableTypes =
-      (1 << kUpb_FieldType_String) |
-      (1 << kUpb_FieldType_Bytes) |
-      (1 << kUpb_FieldType_Message) |
-      (1 << kUpb_FieldType_Group);
-  // clang-format on
-  return (1 << field_type) & ~kUnpackableTypes;
-}
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
-
-#endif /* UPB_BASE_DESCRIPTOR_CONSTANTS_H_ */
 #ifndef UPB_BASE_STRING_VIEW_H_
 #define UPB_BASE_STRING_VIEW_H_

@ -827,6 +720,109 @@ void upb_Arena_SetTraceHandler(void (*initArenaTraceHandler)(const upb_Arena*,
 #include <stddef.h>


+#ifndef UPB_BASE_DESCRIPTOR_CONSTANTS_H_
+#define UPB_BASE_DESCRIPTOR_CONSTANTS_H_
+
+// Must be last.
+
+// The types a field can have. Note that this list is not identical to the
+// types defined in descriptor.proto, which gives INT32 and SINT32 separate
+// types (we distinguish the two with the "integer encoding" enum below).
+// This enum is an internal convenience only and has no meaning outside of upb.
+typedef enum {
+  kUpb_CType_Bool = 1,
+  kUpb_CType_Float = 2,
+  kUpb_CType_Int32 = 3,
+  kUpb_CType_UInt32 = 4,
+  kUpb_CType_Enum = 5,  // Enum values are int32. TODO: rename
+  kUpb_CType_Message = 6,
+  kUpb_CType_Double = 7,
+  kUpb_CType_Int64 = 8,
+  kUpb_CType_UInt64 = 9,
+  kUpb_CType_String = 10,
+  kUpb_CType_Bytes = 11
+} upb_CType;
+
+// The repeated-ness of each field; this matches descriptor.proto.
+typedef enum {
+  kUpb_Label_Optional = 1,
+  kUpb_Label_Required = 2,
+  kUpb_Label_Repeated = 3
+} upb_Label;
+
+// Descriptor types, as defined in descriptor.proto.
+typedef enum {
+  kUpb_FieldType_Double = 1,
+  kUpb_FieldType_Float = 2,
+  kUpb_FieldType_Int64 = 3,
+  kUpb_FieldType_UInt64 = 4,
+  kUpb_FieldType_Int32 = 5,
+  kUpb_FieldType_Fixed64 = 6,
+  kUpb_FieldType_Fixed32 = 7,
+  kUpb_FieldType_Bool = 8,
+  kUpb_FieldType_String = 9,
+  kUpb_FieldType_Group = 10,
+  kUpb_FieldType_Message = 11,
+  kUpb_FieldType_Bytes = 12,
+  kUpb_FieldType_UInt32 = 13,
+  kUpb_FieldType_Enum = 14,
+  kUpb_FieldType_SFixed32 = 15,
+  kUpb_FieldType_SFixed64 = 16,
+  kUpb_FieldType_SInt32 = 17,
+  kUpb_FieldType_SInt64 = 18,
+} upb_FieldType;
+
+#define kUpb_FieldType_SizeOf 19
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Convert from upb_FieldType to upb_CType
+UPB_INLINE upb_CType upb_FieldType_CType(upb_FieldType field_type) {
+  static const upb_CType c_type[] = {
+      kUpb_CType_Double,   // kUpb_FieldType_Double
+      kUpb_CType_Float,    // kUpb_FieldType_Float
+      kUpb_CType_Int64,    // kUpb_FieldType_Int64
+      kUpb_CType_UInt64,   // kUpb_FieldType_UInt64
+      kUpb_CType_Int32,    // kUpb_FieldType_Int32
+      kUpb_CType_UInt64,   // kUpb_FieldType_Fixed64
+      kUpb_CType_UInt32,   // kUpb_FieldType_Fixed32
+      kUpb_CType_Bool,     // kUpb_FieldType_Bool
+      kUpb_CType_String,   // kUpb_FieldType_String
+      kUpb_CType_Message,  // kUpb_FieldType_Group
+      kUpb_CType_Message,  // kUpb_FieldType_Message
+      kUpb_CType_Bytes,    // kUpb_FieldType_Bytes
+      kUpb_CType_UInt32,   // kUpb_FieldType_UInt32
+      kUpb_CType_Enum,     // kUpb_FieldType_Enum
+      kUpb_CType_Int32,    // kUpb_FieldType_SFixed32
+      kUpb_CType_Int64,    // kUpb_FieldType_SFixed64
+      kUpb_CType_Int32,    // kUpb_FieldType_SInt32
+      kUpb_CType_Int64,    // kUpb_FieldType_SInt64
+  };
+
+  // -1 here because the enum is one-based but the table is zero-based.
+  return c_type[field_type - 1];
+}
+
+UPB_INLINE bool upb_FieldType_IsPackable(upb_FieldType field_type) {
+  // clang-format off
+  const unsigned kUnpackableTypes =
+      (1 << kUpb_FieldType_String) |
+      (1 << kUpb_FieldType_Bytes) |
+      (1 << kUpb_FieldType_Message) |
+      (1 << kUpb_FieldType_Group);
+  // clang-format on
+  return (1 << field_type) & ~kUnpackableTypes;
+}
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+
+#endif /* UPB_BASE_DESCRIPTOR_CONSTANTS_H_ */
+
 #ifndef UPB_MESSAGE_INTERNAL_ARRAY_H_
 #define UPB_MESSAGE_INTERNAL_ARRAY_H_

@ -1845,6 +1841,7 @@ UPB_INLINE uint64_t upb_BigEndian64(uint64_t val) {
 #ifndef UPB_MINI_TABLE_INTERNAL_EXTENSION_H_
 #define UPB_MINI_TABLE_INTERNAL_EXTENSION_H_

+#include <stddef.h>
 #include <stdint.h>


@ -1874,6 +1871,9 @@ upb_MiniTableExtension_Number(const struct upb_MiniTableExtension* e) {

 UPB_API_INLINE const struct upb_MiniTable* upb_MiniTableExtension_GetSubMessage(
    const struct upb_MiniTableExtension* e) {
+  if (upb_MiniTableExtension_CType(e) != kUpb_CType_Message) {
+    return NULL;
+  }
  return upb_MiniTableSub_Message(e->UPB_PRIVATE(sub));
 }

@ -1882,6 +1882,11 @@ UPB_API_INLINE void upb_MiniTableExtension_SetSubMessage(
  e->UPB_PRIVATE(sub).UPB_PRIVATE(submsg) = m;
 }

+UPB_INLINE upb_FieldRep UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(
+    const struct upb_MiniTableExtension* e) {
+  return UPB_PRIVATE(_upb_MiniTableField_GetRep)(&e->UPB_PRIVATE(field));
+}
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
@ -2796,7 +2801,6 @@ UPB_INLINE bool UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(
 //                                       const upb_MiniTableField* field,
 //                                       bool value, upb_Arena* a) {
 //     UPB_ASSUME(field->UPB_PRIVATE(descriptortype) == kUpb_FieldType_Bool);
-//     UPB_ASSUME(upb_MiniTableField_IsScalar(field));
 //     UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(field) ==
 //                kUpb_FieldRep_1Byte);
 //     upb_Message_SetField(msg, field, &value, a);
@ -2927,8 +2931,8 @@ UPB_API_INLINE bool upb_Message_GetBool(const struct upb_Message* msg,
                                        const upb_MiniTableField* f,
                                        bool default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Bool);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  upb_MessageValue def;
  def.bool_val = default_val;
  return upb_Message_GetField(msg, f, def).bool_val;
@ -2938,8 +2942,8 @@ UPB_API_INLINE double upb_Message_GetDouble(const struct upb_Message* msg,
                                            const upb_MiniTableField* f,
                                            double default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.double_val = default_val;
@ -2950,8 +2954,8 @@ UPB_API_INLINE float upb_Message_GetFloat(const struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          float default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.float_val = default_val;
@ -2963,8 +2967,8 @@ UPB_API_INLINE int32_t upb_Message_GetInt32(const struct upb_Message* msg,
                                            int32_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.int32_val = default_val;
@ -2975,8 +2979,8 @@ UPB_API_INLINE int64_t upb_Message_GetInt64(const struct upb_Message* msg,
                                            const upb_MiniTableField* f,
                                            int64_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.int64_val = default_val;
@ -3005,6 +3009,37 @@ UPB_API_INLINE const struct upb_Map* upb_Message_GetMap(
  return ret;
 }

+UPB_API_INLINE uintptr_t upb_Message_GetTaggedMessagePtr(
+    const struct upb_Message* msg, const upb_MiniTableField* f,
+    struct upb_Message* default_val) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  uintptr_t tagged;
+  _upb_Message_GetNonExtensionField(msg, f, &default_val, &tagged);
+  return tagged;
+}
+
+// For internal use only; users cannot set tagged messages because only the
+// parser and the message copier are allowed to directly create an empty
+// message.
+UPB_INLINE void UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)(
+    struct upb_Message* msg, const upb_MiniTableField* f,
+    uintptr_t sub_message) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  upb_Message_SetBaseField(msg, f, &sub_message);
+}
+
+UPB_API_INLINE const struct upb_Message* upb_Message_GetMessage(
+    const struct upb_Message* msg, const upb_MiniTableField* f) {
+  uintptr_t tagged = upb_Message_GetTaggedMessagePtr(msg, f, NULL);
+  return upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
+}
+
 UPB_API_INLINE upb_Array* upb_Message_GetMutableArray(
    struct upb_Message* msg, const upb_MiniTableField* f) {
  UPB_PRIVATE(_upb_MiniTableField_CheckIsArray)(f);
@ -3016,6 +3051,11 @@ UPB_API_INLINE struct upb_Map* upb_Message_GetMutableMap(
  return (struct upb_Map*)upb_Message_GetMap(msg, f);
 }

+UPB_API_INLINE struct upb_Message* upb_Message_GetMutableMessage(
+    struct upb_Message* msg, const upb_MiniTableField* f) {
+  return (struct upb_Message*)upb_Message_GetMessage(msg, f);
+}
+
 UPB_API_INLINE upb_Array* upb_Message_GetOrCreateMutableArray(
    struct upb_Message* msg, const upb_MiniTableField* f, upb_Arena* arena) {
  UPB_ASSERT(arena);
@ -3091,7 +3131,6 @@ upb_Message_GetString(const struct upb_Message* msg,
             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
             kUpb_FieldRep_StringView);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));

  upb_MessageValue def;
  def.str_val = default_val;
@ -3102,8 +3141,8 @@ UPB_API_INLINE uint32_t upb_Message_GetUInt32(const struct upb_Message* msg,
                                              const upb_MiniTableField* f,
                                              uint32_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.uint32_val = default_val;
@ -3114,23 +3153,89 @@ UPB_API_INLINE uint64_t upb_Message_GetUInt64(const struct upb_Message* msg,
                                              const upb_MiniTableField* f,
                                              uint64_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.uint64_val = default_val;
  return upb_Message_GetField(msg, f, def).uint64_val;
 }

-UPB_API_INLINE bool upb_Message_SetBool(struct upb_Message* msg,
-                                        const upb_MiniTableField* f, bool value,
-                                        upb_Arena* a) {
+// BaseField Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE void upb_Message_SetBaseFieldBool(struct upb_Message* msg,
+                                                 const upb_MiniTableField* f,
+                                                 bool value) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Bool);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.bool_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldDouble(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   double value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldFloat(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  float value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldInt32(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  int32_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
+             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldInt64(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  int64_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldString(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   upb_StringView value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_String ||
+             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             kUpb_FieldRep_StringView);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldUInt32(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   uint32_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldUInt64(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   uint64_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
 }

 UPB_API_INLINE void upb_Message_SetClosedEnum(
@ -3138,55 +3243,141 @@ UPB_API_INLINE void upb_Message_SetClosedEnum(
    const upb_MiniTableField* f, int32_t value) {
  UPB_ASSERT(upb_MiniTableField_IsClosedEnum(f));
  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
  UPB_ASSERT(upb_MiniTableEnum_CheckValue(
      upb_MiniTable_GetSubEnumTable(msg_mini_table, f), value));
  upb_Message_SetBaseField(msg, f, &value);
 }

+// Extension Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE bool upb_Message_SetExtensionBool(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, bool value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Bool);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_1Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionDouble(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, double value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Double);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionFloat(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, float value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Float);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionInt32(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, int32_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Int32 ||
+             upb_MiniTableExtension_CType(e) == kUpb_CType_Enum);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionInt64(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, int64_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Int64);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionString(
+    struct upb_Message* msg, const upb_MiniTableExtension* e,
+    upb_StringView value, upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_String ||
+             upb_MiniTableExtension_CType(e) == kUpb_CType_Bytes);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_StringView);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionUInt32(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, uint32_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_UInt32);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionUInt64(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, uint64_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_UInt64);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+// Universal Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE bool upb_Message_SetBool(struct upb_Message* msg,
+                                        const upb_MiniTableField* f, bool value,
+                                        upb_Arena* a) {
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionBool(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldBool(msg, f, value), true);
+}
+
 UPB_API_INLINE bool upb_Message_SetDouble(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          double value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.double_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionDouble(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldDouble(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetFloat(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         float value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.float_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionFloat(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldFloat(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetInt32(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int32_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
-             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.int32_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionInt32(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldInt32(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetInt64(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int64_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.int64_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionInt64(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldInt64(msg, f, value), true);
+}
+
+// Sets the value of a message-typed field. The mini_tables of `msg` and
+// `value` must have been linked for this to work correctly.
+UPB_API_INLINE void upb_Message_SetMessage(struct upb_Message* msg,
+                                           const upb_MiniTableField* f,
+                                           struct upb_Message* value) {
+  UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
+  (msg, f, UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(value, false));
 }

 // Sets the value of a `string` or `bytes` field. The bytes of the value are not
@ -3196,36 +3387,28 @@ UPB_API_INLINE bool upb_Message_SetInt64(struct upb_Message* msg,
 UPB_API_INLINE bool upb_Message_SetString(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          upb_StringView value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_String ||
-             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
-             kUpb_FieldRep_StringView);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.str_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionString(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldString(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetUInt32(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint32_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.uint32_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionUInt32(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldUInt32(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetUInt64(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint64_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.uint64_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionUInt64(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldUInt64(msg, f, value), true);
 }

 UPB_API_INLINE void upb_Message_Clear(struct upb_Message* msg,
@ -3504,41 +3687,6 @@ UPB_API_INLINE upb_Message* upb_TaggedMessagePtr_GetNonEmptyMessage(

 #endif /* UPB_MINI_TABLE_TAGGED_PTR_H_ */

-#ifndef UPB_MINI_TABLE_SUB_H_
-#define UPB_MINI_TABLE_SUB_H_
-
-
-// Must be last.
-
-typedef union upb_MiniTableSub upb_MiniTableSub;
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-// Constructors
-
-UPB_API_INLINE upb_MiniTableSub
-upb_MiniTableSub_FromEnum(const upb_MiniTableEnum* subenum);
-
-UPB_API_INLINE upb_MiniTableSub
-upb_MiniTableSub_FromMessage(const upb_MiniTable* submsg);
-
-// Getters
-
-UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTableSub_Enum(
-    upb_MiniTableSub sub);
-
-UPB_API_INLINE const upb_MiniTable* upb_MiniTableSub_Message(
-    upb_MiniTableSub sub);
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
-
-#endif /* UPB_MINI_TABLE_SUB_H_ */
-
 // Must be last.

 #ifdef __cplusplus
@ -3581,6 +3729,10 @@ UPB_API_INLINE upb_MessageValue
 upb_Message_GetField(const upb_Message* msg, const upb_MiniTableField* f,
                     upb_MessageValue default_val);

+UPB_API_INLINE upb_TaggedMessagePtr upb_Message_GetTaggedMessagePtr(
+    const upb_Message* msg, const upb_MiniTableField* field,
+    upb_Message* default_val);
+
 UPB_API_INLINE const upb_Array* upb_Message_GetArray(
    const upb_Message* msg, const upb_MiniTableField* f);

@ -3607,12 +3759,18 @@ UPB_API_INLINE int64_t upb_Message_GetInt64(const upb_Message* msg,
 UPB_API_INLINE const upb_Map* upb_Message_GetMap(const upb_Message* msg,
                                                 const upb_MiniTableField* f);

+UPB_API_INLINE const upb_Message* upb_Message_GetMessage(
+    const upb_Message* msg, const upb_MiniTableField* f);
+
 UPB_API_INLINE upb_Array* upb_Message_GetMutableArray(
    upb_Message* msg, const upb_MiniTableField* f);

 UPB_API_INLINE upb_Map* upb_Message_GetMutableMap(upb_Message* msg,
                                                  const upb_MiniTableField* f);

+UPB_API_INLINE upb_Message* upb_Message_GetMutableMessage(
+    upb_Message* msg, const upb_MiniTableField* f);
+
 UPB_API_INLINE upb_Array* upb_Message_GetOrCreateMutableArray(
    upb_Message* msg, const upb_MiniTableField* f, upb_Arena* arena);

@ -3660,6 +3818,10 @@ UPB_API_INLINE bool upb_Message_SetInt64(upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int64_t value, upb_Arena* a);

+UPB_API_INLINE void upb_Message_SetMessage(upb_Message* msg,
+                                           const upb_MiniTableField* f,
+                                           upb_Message* value);
+
 UPB_API_INLINE bool upb_Message_SetString(upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          upb_StringView value, upb_Arena* a);
@ -3672,55 +3834,6 @@ UPB_API_INLINE bool upb_Message_SetUInt64(upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint64_t value, upb_Arena* a);

-UPB_API_INLINE upb_TaggedMessagePtr upb_Message_GetTaggedMessagePtr(
-    const upb_Message* msg, const upb_MiniTableField* field,
-    upb_Message* default_val) {
-  UPB_ASSUME(upb_MiniTableField_CType(field) == kUpb_CType_Message);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(field) ==
-             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
-  UPB_ASSUME(upb_MiniTableField_IsScalar(field));
-  upb_TaggedMessagePtr tagged;
-  _upb_Message_GetNonExtensionField(msg, field, &default_val, &tagged);
-  return tagged;
-}
-
-UPB_API_INLINE const upb_Message* upb_Message_GetMessage(
-    const upb_Message* msg, const upb_MiniTableField* field) {
-  upb_TaggedMessagePtr tagged =
-      upb_Message_GetTaggedMessagePtr(msg, field, NULL);
-  return upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
-}
-
-UPB_API_INLINE upb_Message* upb_Message_GetMutableMessage(
-    upb_Message* msg, const upb_MiniTableField* field) {
-  return (upb_Message*)upb_Message_GetMessage(msg, field);
-}
-
-// For internal use only; users cannot set tagged messages because only the
-// parser and the message copier are allowed to directly create an empty
-// message.
-UPB_INLINE void UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)(
-    struct upb_Message* msg, const upb_MiniTable* mini_table,
-    const upb_MiniTableField* f, upb_TaggedMessagePtr sub_message) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
-             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_Message_SetBaseField(msg, f, &sub_message);
-}
-
-// Sets the value of a message-typed field. The `mini_table` and `field`
-// parameters belong to `msg`, not `sub_message`. The mini_tables of `msg` and
-// `sub_message` must have been linked for this to work correctly.
-UPB_API_INLINE void upb_Message_SetMessage(upb_Message* msg,
-                                           const upb_MiniTable* mini_table,
-                                           const upb_MiniTableField* field,
-                                           upb_Message* sub_message) {
-  UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
-  (msg, mini_table, field,
-   UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(sub_message, false));
-}
-
 UPB_API_INLINE void* upb_Message_ResizeArrayUninitialized(
    upb_Message* msg, const upb_MiniTableField* f, size_t size,
    upb_Arena* arena);
@ -3793,6 +3906,41 @@ UPB_INLINE void _upb_msg_map_set_value(void* msg, const void* val,
 #define UPB_MINI_TABLE_DECODE_H_


+#ifndef UPB_MINI_TABLE_SUB_H_
+#define UPB_MINI_TABLE_SUB_H_
+
+
+// Must be last.
+
+typedef union upb_MiniTableSub upb_MiniTableSub;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Constructors
+
+UPB_API_INLINE upb_MiniTableSub
+upb_MiniTableSub_FromEnum(const upb_MiniTableEnum* subenum);
+
+UPB_API_INLINE upb_MiniTableSub
+upb_MiniTableSub_FromMessage(const upb_MiniTable* submsg);
+
+// Getters
+
+UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTableSub_Enum(
+    upb_MiniTableSub sub);
+
+UPB_API_INLINE const upb_MiniTable* upb_MiniTableSub_Message(
+    upb_MiniTableSub sub);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+
+#endif /* UPB_MINI_TABLE_SUB_H_ */
+
 // Export the newer headers, for legacy users.  New users should include the
 // more specific headers directly.
 // IWYU pragma: begin_exports
--- a/php/src/Google/Protobuf/Internal/Message.php
+++ b/php/src/Google/Protobuf/Internal/Message.php
@ -394,7 +394,8 @@ class Message
                }
                break;
            case GPBType::STRING:
-                // TODO: Add utf-8 check.
+                // We don't check UTF-8 here; that will be validated by the
+                // setter later.
                if (!GPBWire::readString($input, $value)) {
                    throw new GPBDecodeException(
                        "Unexpected EOF inside string field.");
--- a/php/tests/EncodeDecodeTest.php
+++ b/php/tests/EncodeDecodeTest.php
@ -683,6 +683,21 @@ class EncodeDecodeTest extends TestBase
        $m->mergeFromString(hex2bin('7201'));
    }

+    public function testDecodeInvalidStringDataBadUtf8()
+    {
+        $this->expectException(Exception::class);
+
+        $m = new TestMessage();
+        $m->mergeFromString(hex2bin('720180'));
+    }
+
+    public function testDecodeValidStringData()
+    {
+        $m = new TestMessage();
+        $m->mergeFromString(hex2bin('720161'));
+        $this->assertSame('a', $m->getOptionalString());
+    }
+
    public function testDecodeInvalidBytesLengthMiss()
    {
        $this->expectException(Exception::class);
--- a/protobuf.bzl
+++ b/protobuf.bzl
@ -80,6 +80,7 @@ def _proto_gen_impl(ctx):
    srcs = ctx.files.srcs
    langs = ctx.attr.langs or []
    out_type = ctx.attr.out_type
+    enable_editions = ctx.attr.enable_editions
    deps = depset(direct = ctx.files.srcs)
    source_dir = _SourceDir(ctx)
    gen_dir = _GenDir(ctx).rstrip("/")
@ -130,6 +131,8 @@ def _proto_gen_impl(ctx):
    generated_files = []
    for src in srcs:
        args = []
+        if enable_editions:
+            args.append("--experimental_editions")

        in_gen_dir = src.root.path == gen_dir
        if in_gen_dir:
@ -231,6 +234,7 @@ Args:
  srcs: Protocol Buffers definition files (.proto) to run the protocol compiler
    against.
  deps: a list of dependency labels; must be other proto libraries.
+  enable_editions: if true, sets the --experimental_editions flag.
  includes: a list of include paths to .proto files.
  protoc: the label of the protocol compiler to generate the sources.
  plugin: the label of the protocol compiler plugin to be passed to the protocol
@ -247,6 +251,7 @@ _proto_gen = rule(
    attrs = {
        "srcs": attr.label_list(allow_files = True),
        "deps": attr.label_list(providers = [ProtoGenInfo]),
+        "enable_editions": attr.bool(),
        "includes": attr.string_list(),
        "protoc": attr.label(
            cfg = "exec",
@ -655,6 +660,7 @@ def _source_proto_library(
        protoc = Label("//:protoc"),
        testonly = None,
        visibility = ["//visibility:public"],
+        enable_editions = False,
        **kwargs):
    """Bazel rule to create generated protobuf code from proto source files for
    languages not well supported by Bazel yet.  This will output the generated
@ -699,6 +705,7 @@ def _source_proto_library(
            srcs = proto_deps,
            protoc = protoc,
            includes = includes,
+            enable_editions = enable_editions,
        )
        full_deps.append(":%s_deps_genproto" % name)

@ -712,6 +719,7 @@ def _source_proto_library(
        protoc = protoc,
        testonly = testonly,
        visibility = visibility,
+        enable_editions = enable_editions,
    )

    native.filegroup(
--- a/protos_generator/gen_messages.cc
+++ b/protos_generator/gen_messages.cc
@ -7,11 +7,14 @@

 #include "protos_generator/gen_messages.h"

+#include <cstddef>
 #include <string>
 #include <vector>

 #include "google/protobuf/descriptor.pb.h"
+#include "absl/strings/ascii.h"
 #include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
 #include "google/protobuf/descriptor.h"
 #include "protos_generator/gen_accessors.h"
 #include "protos_generator/gen_enums.h"
@ -120,6 +123,55 @@ void WriteModelAccessDeclaration(const protobuf::Descriptor* descriptor,
  output("};\n");
 }

+std::string UnderscoresToCamelCase(absl::string_view input,
+                                   bool cap_next_letter) {
+  std::string result;
+
+  for (size_t i = 0; i < input.size(); i++) {
+    if (absl::ascii_islower(input[i])) {
+      if (cap_next_letter) {
+        result += absl::ascii_toupper(input[i]);
+      } else {
+        result += input[i];
+      }
+      cap_next_letter = false;
+    } else if (absl::ascii_isupper(input[i])) {
+      // Capital letters are left as-is.
+      result += input[i];
+      cap_next_letter = false;
+    } else if (absl::ascii_isdigit(input[i])) {
+      result += input[i];
+      cap_next_letter = true;
+    } else {
+      cap_next_letter = true;
+    }
+  }
+  return result;
+}
+
+std::string FieldConstantName(const protobuf::FieldDescriptor* field) {
+  std::string field_name = UnderscoresToCamelCase(field->name(), true);
+  std::string result = absl::StrCat("k", field_name, "FieldNumber");
+
+  if (!field->is_extension() &&
+      field->containing_type()->FindFieldByCamelcaseName(
+          field->camelcase_name()) != field) {
+    // This field's camelcase name is not unique, add field number to make it
+    // unique.
+    absl::StrAppend(&result, "_", field->number());
+  }
+  return result;
+}
+
+void WriteConstFieldNumbers(Output& output,
+                            const protobuf::Descriptor* descriptor) {
+  for (auto field : FieldRange(descriptor)) {
+    output("static constexpr ::uint32_t $0 = $1;\n", FieldConstantName(field),
+           field->number());
+  }
+  output("\n\n");
+}
+
 void WriteModelPublicDeclaration(
    const protobuf::Descriptor* descriptor,
    const std::vector<const protobuf::FieldDescriptor*>& file_exts,
@ -178,6 +230,7 @@ void WriteModelPublicDeclaration(
      )cc",
      ClassName(descriptor));
  output("\n");
+  WriteConstFieldNumbers(output, descriptor);
  output(
      R"cc(
        private:
--- a/protos_generator/tests/test_generated.cc
+++ b/protos_generator/tests/test_generated.cc
@ -9,6 +9,7 @@
 #include <limits>
 #include <memory>
 #include <string>
+#include <type_traits>
 #include <utility>
 #include <vector>

@ -1134,6 +1135,11 @@ TEST(CppGeneratedCode, HasExtensionAndRegistry) {
  EXPECT_TRUE(::protos::HasExtension(&parsed_model, theme));
 }

+TEST(CppGeneratedCode, FieldNumberConstants) {
+  static_assert(TestModel::kChildMapFieldNumber == 225);
+  EXPECT_EQ(225, TestModel::kChildMapFieldNumber);
+}
+
 // TODO : Add BUILD rule to test failures below.
 #ifdef TEST_CLEAR_MESSAGE_FAILURE
 TEST(CppGeneratedCode, ClearConstMessageShouldFail) {
--- a/python/google/protobuf/internal/proto_test.py
+++ b/python/google/protobuf/internal/proto_test.py
@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Tests Nextgen Pythonic protobuf APIs."""
+
+import unittest
+
+from google.protobuf import proto
+
+from google.protobuf.internal import test_util
+from google.protobuf.internal import testing_refleaks
+from google.protobuf.internal import _parameterized
+from google.protobuf import unittest_pb2
+from google.protobuf import unittest_proto3_arena_pb2
+
+@_parameterized.named_parameters(('_proto2', unittest_pb2),
+                                ('_proto3', unittest_proto3_arena_pb2))
+@testing_refleaks.TestCase
+class ProtoTest(unittest.TestCase):
+
+  def testSerializeParse(self, message_module):
+    msg = message_module.TestAllTypes()
+    test_util.SetAllFields(msg)
+    serialized_data = proto.serialize(msg)
+    parsed_msg = proto.parse(message_module.TestAllTypes, serialized_data)
+    self.assertEqual(msg, parsed_msg)
+
+if __name__ == '__main__':
+  unittest.main()
--- a/python/google/protobuf/proto.py
+++ b/python/google/protobuf/proto.py
@ -0,0 +1,39 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Contains the Nextgen Pythonic protobuf APIs."""
+
+import typing
+
+from google.protobuf.message import Message
+
+def serialize(message: Message, deterministic: bool=None) -> bytes:
+  """Return the serialized proto.
+
+  Args:
+    message: The proto message to be serialized.
+    deterministic: If true, requests deterministic serialization
+        of the protobuf, with predictable ordering of map keys.
+
+  Returns:
+    A binary bytes representation of the message.
+  """
+  return message.SerializeToString(deterministic=deterministic)
+
+def parse(message_class: typing.Type[Message], payload: bytes) -> Message:
+  """Given a serialized data in binary form, deserialize it into a Message.
+
+  Args:
+    message_class: The message meta class.
+    payload: A serialized bytes in binary form.
+
+  Returns:
+    A new message deserialized from payload.
+  """
+  new_message = message_class()
+  new_message.ParseFromString(payload)
+  return new_message
--- a/python/message.c
+++ b/python/message.c
@ -1039,9 +1039,9 @@ static PyObject* PyUpb_Message_HasField(PyObject* _self, PyObject* arg) {

  if (PyUpb_Message_IsStub(self)) Py_RETURN_FALSE;

-  return PyBool_FromLong(field ? upb_Message_HasFieldByDef(self->ptr.msg, field)
-                               : upb_Message_WhichOneof(self->ptr.msg, oneof) !=
-                                     NULL);
+  return PyBool_FromLong(
+      field ? upb_Message_HasFieldByDef(self->ptr.msg, field)
+            : upb_Message_WhichOneofByDef(self->ptr.msg, oneof) != NULL);
 }

 static PyObject* PyUpb_Message_Contains(PyObject* _self, PyObject* arg) {
@ -1421,7 +1421,7 @@ static PyObject* PyUpb_Message_ClearField(PyObject* _self, PyObject* arg) {
    return NULL;
  }

-  if (o) f = upb_Message_WhichOneof(self->ptr.msg, o);
+  if (o) f = upb_Message_WhichOneofByDef(self->ptr.msg, o);
  if (f) PyUpb_Message_DoClearField(_self, f);
  Py_RETURN_NONE;
 }
@ -1616,7 +1616,7 @@ static PyObject* PyUpb_Message_WhichOneof(PyObject* _self, PyObject* name) {
  }
  upb_Message* msg = PyUpb_Message_GetIfReified(_self);
  if (!msg) Py_RETURN_NONE;
-  const upb_FieldDef* f = upb_Message_WhichOneof(msg, o);
+  const upb_FieldDef* f = upb_Message_WhichOneofByDef(msg, o);
  if (!f) Py_RETURN_NONE;
  return PyUnicode_FromString(upb_FieldDef_Name(f));
 }
--- a/ruby/ext/google/protobuf_c/message.c
+++ b/ruby/ext/google/protobuf_c/message.c
@ -248,7 +248,7 @@ static int extract_method_call(VALUE method_name, Message* self,
 static VALUE Message_oneof_accessor(VALUE _self, const upb_OneofDef* o,
                                    int accessor_type) {
  Message* self = ruby_to_Message(_self);
-  const upb_FieldDef* oneof_field = upb_Message_WhichOneof(self->msg, o);
+  const upb_FieldDef* oneof_field = upb_Message_WhichOneofByDef(self->msg, o);

  switch (accessor_type) {
    case METHOD_PRESENCE:
--- a/ruby/ext/google/protobuf_c/ruby-upb.c
+++ b/ruby/ext/google/protobuf_c/ruby-upb.c
@ -5650,7 +5650,7 @@ upb_Message* _upb_Message_Copy(upb_Message* dst, const upb_Message* src,
              return NULL;
            }
            UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
-            (dst, mini_table, field,
+            (dst, field,
             UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(dst_sub_message,
                                                     is_empty));
          }
--- a/ruby/ext/google/protobuf_c/ruby-upb.h
+++ b/ruby/ext/google/protobuf_c/ruby-upb.h
@ -415,113 +415,6 @@ void upb_Status_VAppendErrorFormat(upb_Status* status, const char* fmt,
 #ifndef UPB_MESSAGE_ACCESSORS_H_
 #define UPB_MESSAGE_ACCESSORS_H_

-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-
-#ifndef UPB_BASE_DESCRIPTOR_CONSTANTS_H_
-#define UPB_BASE_DESCRIPTOR_CONSTANTS_H_
-
-// Must be last.
-
-// The types a field can have. Note that this list is not identical to the
-// types defined in descriptor.proto, which gives INT32 and SINT32 separate
-// types (we distinguish the two with the "integer encoding" enum below).
-// This enum is an internal convenience only and has no meaning outside of upb.
-typedef enum {
-  kUpb_CType_Bool = 1,
-  kUpb_CType_Float = 2,
-  kUpb_CType_Int32 = 3,
-  kUpb_CType_UInt32 = 4,
-  kUpb_CType_Enum = 5,  // Enum values are int32. TODO: rename
-  kUpb_CType_Message = 6,
-  kUpb_CType_Double = 7,
-  kUpb_CType_Int64 = 8,
-  kUpb_CType_UInt64 = 9,
-  kUpb_CType_String = 10,
-  kUpb_CType_Bytes = 11
-} upb_CType;
-
-// The repeated-ness of each field; this matches descriptor.proto.
-typedef enum {
-  kUpb_Label_Optional = 1,
-  kUpb_Label_Required = 2,
-  kUpb_Label_Repeated = 3
-} upb_Label;
-
-// Descriptor types, as defined in descriptor.proto.
-typedef enum {
-  kUpb_FieldType_Double = 1,
-  kUpb_FieldType_Float = 2,
-  kUpb_FieldType_Int64 = 3,
-  kUpb_FieldType_UInt64 = 4,
-  kUpb_FieldType_Int32 = 5,
-  kUpb_FieldType_Fixed64 = 6,
-  kUpb_FieldType_Fixed32 = 7,
-  kUpb_FieldType_Bool = 8,
-  kUpb_FieldType_String = 9,
-  kUpb_FieldType_Group = 10,
-  kUpb_FieldType_Message = 11,
-  kUpb_FieldType_Bytes = 12,
-  kUpb_FieldType_UInt32 = 13,
-  kUpb_FieldType_Enum = 14,
-  kUpb_FieldType_SFixed32 = 15,
-  kUpb_FieldType_SFixed64 = 16,
-  kUpb_FieldType_SInt32 = 17,
-  kUpb_FieldType_SInt64 = 18,
-} upb_FieldType;
-
-#define kUpb_FieldType_SizeOf 19
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-// Convert from upb_FieldType to upb_CType
-UPB_INLINE upb_CType upb_FieldType_CType(upb_FieldType field_type) {
-  static const upb_CType c_type[] = {
-      kUpb_CType_Double,   // kUpb_FieldType_Double
-      kUpb_CType_Float,    // kUpb_FieldType_Float
-      kUpb_CType_Int64,    // kUpb_FieldType_Int64
-      kUpb_CType_UInt64,   // kUpb_FieldType_UInt64
-      kUpb_CType_Int32,    // kUpb_FieldType_Int32
-      kUpb_CType_UInt64,   // kUpb_FieldType_Fixed64
-      kUpb_CType_UInt32,   // kUpb_FieldType_Fixed32
-      kUpb_CType_Bool,     // kUpb_FieldType_Bool
-      kUpb_CType_String,   // kUpb_FieldType_String
-      kUpb_CType_Message,  // kUpb_FieldType_Group
-      kUpb_CType_Message,  // kUpb_FieldType_Message
-      kUpb_CType_Bytes,    // kUpb_FieldType_Bytes
-      kUpb_CType_UInt32,   // kUpb_FieldType_UInt32
-      kUpb_CType_Enum,     // kUpb_FieldType_Enum
-      kUpb_CType_Int32,    // kUpb_FieldType_SFixed32
-      kUpb_CType_Int64,    // kUpb_FieldType_SFixed64
-      kUpb_CType_Int32,    // kUpb_FieldType_SInt32
-      kUpb_CType_Int64,    // kUpb_FieldType_SInt64
-  };
-
-  // -1 here because the enum is one-based but the table is zero-based.
-  return c_type[field_type - 1];
-}
-
-UPB_INLINE bool upb_FieldType_IsPackable(upb_FieldType field_type) {
-  // clang-format off
-  const unsigned kUnpackableTypes =
-      (1 << kUpb_FieldType_String) |
-      (1 << kUpb_FieldType_Bytes) |
-      (1 << kUpb_FieldType_Message) |
-      (1 << kUpb_FieldType_Group);
-  // clang-format on
-  return (1 << field_type) & ~kUnpackableTypes;
-}
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
-
-#endif /* UPB_BASE_DESCRIPTOR_CONSTANTS_H_ */
 #ifndef UPB_BASE_STRING_VIEW_H_
 #define UPB_BASE_STRING_VIEW_H_

@ -829,6 +722,109 @@ void upb_Arena_SetTraceHandler(void (*initArenaTraceHandler)(const upb_Arena*,
 #include <stddef.h>


+#ifndef UPB_BASE_DESCRIPTOR_CONSTANTS_H_
+#define UPB_BASE_DESCRIPTOR_CONSTANTS_H_
+
+// Must be last.
+
+// The types a field can have. Note that this list is not identical to the
+// types defined in descriptor.proto, which gives INT32 and SINT32 separate
+// types (we distinguish the two with the "integer encoding" enum below).
+// This enum is an internal convenience only and has no meaning outside of upb.
+typedef enum {
+  kUpb_CType_Bool = 1,
+  kUpb_CType_Float = 2,
+  kUpb_CType_Int32 = 3,
+  kUpb_CType_UInt32 = 4,
+  kUpb_CType_Enum = 5,  // Enum values are int32. TODO: rename
+  kUpb_CType_Message = 6,
+  kUpb_CType_Double = 7,
+  kUpb_CType_Int64 = 8,
+  kUpb_CType_UInt64 = 9,
+  kUpb_CType_String = 10,
+  kUpb_CType_Bytes = 11
+} upb_CType;
+
+// The repeated-ness of each field; this matches descriptor.proto.
+typedef enum {
+  kUpb_Label_Optional = 1,
+  kUpb_Label_Required = 2,
+  kUpb_Label_Repeated = 3
+} upb_Label;
+
+// Descriptor types, as defined in descriptor.proto.
+typedef enum {
+  kUpb_FieldType_Double = 1,
+  kUpb_FieldType_Float = 2,
+  kUpb_FieldType_Int64 = 3,
+  kUpb_FieldType_UInt64 = 4,
+  kUpb_FieldType_Int32 = 5,
+  kUpb_FieldType_Fixed64 = 6,
+  kUpb_FieldType_Fixed32 = 7,
+  kUpb_FieldType_Bool = 8,
+  kUpb_FieldType_String = 9,
+  kUpb_FieldType_Group = 10,
+  kUpb_FieldType_Message = 11,
+  kUpb_FieldType_Bytes = 12,
+  kUpb_FieldType_UInt32 = 13,
+  kUpb_FieldType_Enum = 14,
+  kUpb_FieldType_SFixed32 = 15,
+  kUpb_FieldType_SFixed64 = 16,
+  kUpb_FieldType_SInt32 = 17,
+  kUpb_FieldType_SInt64 = 18,
+} upb_FieldType;
+
+#define kUpb_FieldType_SizeOf 19
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Convert from upb_FieldType to upb_CType
+UPB_INLINE upb_CType upb_FieldType_CType(upb_FieldType field_type) {
+  static const upb_CType c_type[] = {
+      kUpb_CType_Double,   // kUpb_FieldType_Double
+      kUpb_CType_Float,    // kUpb_FieldType_Float
+      kUpb_CType_Int64,    // kUpb_FieldType_Int64
+      kUpb_CType_UInt64,   // kUpb_FieldType_UInt64
+      kUpb_CType_Int32,    // kUpb_FieldType_Int32
+      kUpb_CType_UInt64,   // kUpb_FieldType_Fixed64
+      kUpb_CType_UInt32,   // kUpb_FieldType_Fixed32
+      kUpb_CType_Bool,     // kUpb_FieldType_Bool
+      kUpb_CType_String,   // kUpb_FieldType_String
+      kUpb_CType_Message,  // kUpb_FieldType_Group
+      kUpb_CType_Message,  // kUpb_FieldType_Message
+      kUpb_CType_Bytes,    // kUpb_FieldType_Bytes
+      kUpb_CType_UInt32,   // kUpb_FieldType_UInt32
+      kUpb_CType_Enum,     // kUpb_FieldType_Enum
+      kUpb_CType_Int32,    // kUpb_FieldType_SFixed32
+      kUpb_CType_Int64,    // kUpb_FieldType_SFixed64
+      kUpb_CType_Int32,    // kUpb_FieldType_SInt32
+      kUpb_CType_Int64,    // kUpb_FieldType_SInt64
+  };
+
+  // -1 here because the enum is one-based but the table is zero-based.
+  return c_type[field_type - 1];
+}
+
+UPB_INLINE bool upb_FieldType_IsPackable(upb_FieldType field_type) {
+  // clang-format off
+  const unsigned kUnpackableTypes =
+      (1 << kUpb_FieldType_String) |
+      (1 << kUpb_FieldType_Bytes) |
+      (1 << kUpb_FieldType_Message) |
+      (1 << kUpb_FieldType_Group);
+  // clang-format on
+  return (1 << field_type) & ~kUnpackableTypes;
+}
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+
+#endif /* UPB_BASE_DESCRIPTOR_CONSTANTS_H_ */
+
 #ifndef UPB_MESSAGE_INTERNAL_ARRAY_H_
 #define UPB_MESSAGE_INTERNAL_ARRAY_H_

@ -1847,6 +1843,7 @@ UPB_INLINE uint64_t upb_BigEndian64(uint64_t val) {
 #ifndef UPB_MINI_TABLE_INTERNAL_EXTENSION_H_
 #define UPB_MINI_TABLE_INTERNAL_EXTENSION_H_

+#include <stddef.h>
 #include <stdint.h>


@ -1876,6 +1873,9 @@ upb_MiniTableExtension_Number(const struct upb_MiniTableExtension* e) {

 UPB_API_INLINE const struct upb_MiniTable* upb_MiniTableExtension_GetSubMessage(
    const struct upb_MiniTableExtension* e) {
+  if (upb_MiniTableExtension_CType(e) != kUpb_CType_Message) {
+    return NULL;
+  }
  return upb_MiniTableSub_Message(e->UPB_PRIVATE(sub));
 }

@ -1884,6 +1884,11 @@ UPB_API_INLINE void upb_MiniTableExtension_SetSubMessage(
  e->UPB_PRIVATE(sub).UPB_PRIVATE(submsg) = m;
 }

+UPB_INLINE upb_FieldRep UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(
+    const struct upb_MiniTableExtension* e) {
+  return UPB_PRIVATE(_upb_MiniTableField_GetRep)(&e->UPB_PRIVATE(field));
+}
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
@ -2798,7 +2803,6 @@ UPB_INLINE bool UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(
 //                                       const upb_MiniTableField* field,
 //                                       bool value, upb_Arena* a) {
 //     UPB_ASSUME(field->UPB_PRIVATE(descriptortype) == kUpb_FieldType_Bool);
-//     UPB_ASSUME(upb_MiniTableField_IsScalar(field));
 //     UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(field) ==
 //                kUpb_FieldRep_1Byte);
 //     upb_Message_SetField(msg, field, &value, a);
@ -2929,8 +2933,8 @@ UPB_API_INLINE bool upb_Message_GetBool(const struct upb_Message* msg,
                                        const upb_MiniTableField* f,
                                        bool default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Bool);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  upb_MessageValue def;
  def.bool_val = default_val;
  return upb_Message_GetField(msg, f, def).bool_val;
@ -2940,8 +2944,8 @@ UPB_API_INLINE double upb_Message_GetDouble(const struct upb_Message* msg,
                                            const upb_MiniTableField* f,
                                            double default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.double_val = default_val;
@ -2952,8 +2956,8 @@ UPB_API_INLINE float upb_Message_GetFloat(const struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          float default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.float_val = default_val;
@ -2965,8 +2969,8 @@ UPB_API_INLINE int32_t upb_Message_GetInt32(const struct upb_Message* msg,
                                            int32_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.int32_val = default_val;
@ -2977,8 +2981,8 @@ UPB_API_INLINE int64_t upb_Message_GetInt64(const struct upb_Message* msg,
                                            const upb_MiniTableField* f,
                                            int64_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.int64_val = default_val;
@ -3007,6 +3011,37 @@ UPB_API_INLINE const struct upb_Map* upb_Message_GetMap(
  return ret;
 }

+UPB_API_INLINE uintptr_t upb_Message_GetTaggedMessagePtr(
+    const struct upb_Message* msg, const upb_MiniTableField* f,
+    struct upb_Message* default_val) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  uintptr_t tagged;
+  _upb_Message_GetNonExtensionField(msg, f, &default_val, &tagged);
+  return tagged;
+}
+
+// For internal use only; users cannot set tagged messages because only the
+// parser and the message copier are allowed to directly create an empty
+// message.
+UPB_INLINE void UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)(
+    struct upb_Message* msg, const upb_MiniTableField* f,
+    uintptr_t sub_message) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  upb_Message_SetBaseField(msg, f, &sub_message);
+}
+
+UPB_API_INLINE const struct upb_Message* upb_Message_GetMessage(
+    const struct upb_Message* msg, const upb_MiniTableField* f) {
+  uintptr_t tagged = upb_Message_GetTaggedMessagePtr(msg, f, NULL);
+  return upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
+}
+
 UPB_API_INLINE upb_Array* upb_Message_GetMutableArray(
    struct upb_Message* msg, const upb_MiniTableField* f) {
  UPB_PRIVATE(_upb_MiniTableField_CheckIsArray)(f);
@ -3018,6 +3053,11 @@ UPB_API_INLINE struct upb_Map* upb_Message_GetMutableMap(
  return (struct upb_Map*)upb_Message_GetMap(msg, f);
 }

+UPB_API_INLINE struct upb_Message* upb_Message_GetMutableMessage(
+    struct upb_Message* msg, const upb_MiniTableField* f) {
+  return (struct upb_Message*)upb_Message_GetMessage(msg, f);
+}
+
 UPB_API_INLINE upb_Array* upb_Message_GetOrCreateMutableArray(
    struct upb_Message* msg, const upb_MiniTableField* f, upb_Arena* arena) {
  UPB_ASSERT(arena);
@ -3093,7 +3133,6 @@ upb_Message_GetString(const struct upb_Message* msg,
             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
             kUpb_FieldRep_StringView);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));

  upb_MessageValue def;
  def.str_val = default_val;
@ -3104,8 +3143,8 @@ UPB_API_INLINE uint32_t upb_Message_GetUInt32(const struct upb_Message* msg,
                                              const upb_MiniTableField* f,
                                              uint32_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.uint32_val = default_val;
@ -3116,23 +3155,89 @@ UPB_API_INLINE uint64_t upb_Message_GetUInt64(const struct upb_Message* msg,
                                              const upb_MiniTableField* f,
                                              uint64_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.uint64_val = default_val;
  return upb_Message_GetField(msg, f, def).uint64_val;
 }

-UPB_API_INLINE bool upb_Message_SetBool(struct upb_Message* msg,
-                                        const upb_MiniTableField* f, bool value,
-                                        upb_Arena* a) {
+// BaseField Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE void upb_Message_SetBaseFieldBool(struct upb_Message* msg,
+                                                 const upb_MiniTableField* f,
+                                                 bool value) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Bool);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.bool_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldDouble(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   double value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldFloat(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  float value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldInt32(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  int32_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
+             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldInt64(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  int64_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldString(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   upb_StringView value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_String ||
+             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             kUpb_FieldRep_StringView);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldUInt32(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   uint32_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldUInt64(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   uint64_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
 }

 UPB_API_INLINE void upb_Message_SetClosedEnum(
@ -3140,55 +3245,141 @@ UPB_API_INLINE void upb_Message_SetClosedEnum(
    const upb_MiniTableField* f, int32_t value) {
  UPB_ASSERT(upb_MiniTableField_IsClosedEnum(f));
  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
  UPB_ASSERT(upb_MiniTableEnum_CheckValue(
      upb_MiniTable_GetSubEnumTable(msg_mini_table, f), value));
  upb_Message_SetBaseField(msg, f, &value);
 }

+// Extension Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE bool upb_Message_SetExtensionBool(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, bool value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Bool);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_1Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionDouble(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, double value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Double);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionFloat(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, float value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Float);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionInt32(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, int32_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Int32 ||
+             upb_MiniTableExtension_CType(e) == kUpb_CType_Enum);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionInt64(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, int64_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Int64);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionString(
+    struct upb_Message* msg, const upb_MiniTableExtension* e,
+    upb_StringView value, upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_String ||
+             upb_MiniTableExtension_CType(e) == kUpb_CType_Bytes);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_StringView);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionUInt32(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, uint32_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_UInt32);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionUInt64(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, uint64_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_UInt64);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+// Universal Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE bool upb_Message_SetBool(struct upb_Message* msg,
+                                        const upb_MiniTableField* f, bool value,
+                                        upb_Arena* a) {
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionBool(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldBool(msg, f, value), true);
+}
+
 UPB_API_INLINE bool upb_Message_SetDouble(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          double value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.double_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionDouble(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldDouble(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetFloat(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         float value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.float_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionFloat(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldFloat(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetInt32(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int32_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
-             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.int32_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionInt32(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldInt32(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetInt64(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int64_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.int64_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionInt64(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldInt64(msg, f, value), true);
+}
+
+// Sets the value of a message-typed field. The mini_tables of `msg` and
+// `value` must have been linked for this to work correctly.
+UPB_API_INLINE void upb_Message_SetMessage(struct upb_Message* msg,
+                                           const upb_MiniTableField* f,
+                                           struct upb_Message* value) {
+  UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
+  (msg, f, UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(value, false));
 }

 // Sets the value of a `string` or `bytes` field. The bytes of the value are not
@ -3198,36 +3389,28 @@ UPB_API_INLINE bool upb_Message_SetInt64(struct upb_Message* msg,
 UPB_API_INLINE bool upb_Message_SetString(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          upb_StringView value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_String ||
-             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
-             kUpb_FieldRep_StringView);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.str_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionString(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldString(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetUInt32(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint32_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.uint32_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionUInt32(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldUInt32(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetUInt64(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint64_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.uint64_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionUInt64(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldUInt64(msg, f, value), true);
 }

 UPB_API_INLINE void upb_Message_Clear(struct upb_Message* msg,
@ -3506,41 +3689,6 @@ UPB_API_INLINE upb_Message* upb_TaggedMessagePtr_GetNonEmptyMessage(

 #endif /* UPB_MINI_TABLE_TAGGED_PTR_H_ */

-#ifndef UPB_MINI_TABLE_SUB_H_
-#define UPB_MINI_TABLE_SUB_H_
-
-
-// Must be last.
-
-typedef union upb_MiniTableSub upb_MiniTableSub;
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-// Constructors
-
-UPB_API_INLINE upb_MiniTableSub
-upb_MiniTableSub_FromEnum(const upb_MiniTableEnum* subenum);
-
-UPB_API_INLINE upb_MiniTableSub
-upb_MiniTableSub_FromMessage(const upb_MiniTable* submsg);
-
-// Getters
-
-UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTableSub_Enum(
-    upb_MiniTableSub sub);
-
-UPB_API_INLINE const upb_MiniTable* upb_MiniTableSub_Message(
-    upb_MiniTableSub sub);
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
-
-#endif /* UPB_MINI_TABLE_SUB_H_ */
-
 // Must be last.

 #ifdef __cplusplus
@ -3583,6 +3731,10 @@ UPB_API_INLINE upb_MessageValue
 upb_Message_GetField(const upb_Message* msg, const upb_MiniTableField* f,
                     upb_MessageValue default_val);

+UPB_API_INLINE upb_TaggedMessagePtr upb_Message_GetTaggedMessagePtr(
+    const upb_Message* msg, const upb_MiniTableField* field,
+    upb_Message* default_val);
+
 UPB_API_INLINE const upb_Array* upb_Message_GetArray(
    const upb_Message* msg, const upb_MiniTableField* f);

@ -3609,12 +3761,18 @@ UPB_API_INLINE int64_t upb_Message_GetInt64(const upb_Message* msg,
 UPB_API_INLINE const upb_Map* upb_Message_GetMap(const upb_Message* msg,
                                                 const upb_MiniTableField* f);

+UPB_API_INLINE const upb_Message* upb_Message_GetMessage(
+    const upb_Message* msg, const upb_MiniTableField* f);
+
 UPB_API_INLINE upb_Array* upb_Message_GetMutableArray(
    upb_Message* msg, const upb_MiniTableField* f);

 UPB_API_INLINE upb_Map* upb_Message_GetMutableMap(upb_Message* msg,
                                                  const upb_MiniTableField* f);

+UPB_API_INLINE upb_Message* upb_Message_GetMutableMessage(
+    upb_Message* msg, const upb_MiniTableField* f);
+
 UPB_API_INLINE upb_Array* upb_Message_GetOrCreateMutableArray(
    upb_Message* msg, const upb_MiniTableField* f, upb_Arena* arena);

@ -3662,6 +3820,10 @@ UPB_API_INLINE bool upb_Message_SetInt64(upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int64_t value, upb_Arena* a);

+UPB_API_INLINE void upb_Message_SetMessage(upb_Message* msg,
+                                           const upb_MiniTableField* f,
+                                           upb_Message* value);
+
 UPB_API_INLINE bool upb_Message_SetString(upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          upb_StringView value, upb_Arena* a);
@ -3674,55 +3836,6 @@ UPB_API_INLINE bool upb_Message_SetUInt64(upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint64_t value, upb_Arena* a);

-UPB_API_INLINE upb_TaggedMessagePtr upb_Message_GetTaggedMessagePtr(
-    const upb_Message* msg, const upb_MiniTableField* field,
-    upb_Message* default_val) {
-  UPB_ASSUME(upb_MiniTableField_CType(field) == kUpb_CType_Message);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(field) ==
-             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
-  UPB_ASSUME(upb_MiniTableField_IsScalar(field));
-  upb_TaggedMessagePtr tagged;
-  _upb_Message_GetNonExtensionField(msg, field, &default_val, &tagged);
-  return tagged;
-}
-
-UPB_API_INLINE const upb_Message* upb_Message_GetMessage(
-    const upb_Message* msg, const upb_MiniTableField* field) {
-  upb_TaggedMessagePtr tagged =
-      upb_Message_GetTaggedMessagePtr(msg, field, NULL);
-  return upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
-}
-
-UPB_API_INLINE upb_Message* upb_Message_GetMutableMessage(
-    upb_Message* msg, const upb_MiniTableField* field) {
-  return (upb_Message*)upb_Message_GetMessage(msg, field);
-}
-
-// For internal use only; users cannot set tagged messages because only the
-// parser and the message copier are allowed to directly create an empty
-// message.
-UPB_INLINE void UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)(
-    struct upb_Message* msg, const upb_MiniTable* mini_table,
-    const upb_MiniTableField* f, upb_TaggedMessagePtr sub_message) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
-             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_Message_SetBaseField(msg, f, &sub_message);
-}
-
-// Sets the value of a message-typed field. The `mini_table` and `field`
-// parameters belong to `msg`, not `sub_message`. The mini_tables of `msg` and
-// `sub_message` must have been linked for this to work correctly.
-UPB_API_INLINE void upb_Message_SetMessage(upb_Message* msg,
-                                           const upb_MiniTable* mini_table,
-                                           const upb_MiniTableField* field,
-                                           upb_Message* sub_message) {
-  UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
-  (msg, mini_table, field,
-   UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(sub_message, false));
-}
-
 UPB_API_INLINE void* upb_Message_ResizeArrayUninitialized(
    upb_Message* msg, const upb_MiniTableField* f, size_t size,
    upb_Arena* arena);
@ -3795,6 +3908,41 @@ UPB_INLINE void _upb_msg_map_set_value(void* msg, const void* val,
 #define UPB_MINI_TABLE_DECODE_H_


+#ifndef UPB_MINI_TABLE_SUB_H_
+#define UPB_MINI_TABLE_SUB_H_
+
+
+// Must be last.
+
+typedef union upb_MiniTableSub upb_MiniTableSub;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Constructors
+
+UPB_API_INLINE upb_MiniTableSub
+upb_MiniTableSub_FromEnum(const upb_MiniTableEnum* subenum);
+
+UPB_API_INLINE upb_MiniTableSub
+upb_MiniTableSub_FromMessage(const upb_MiniTable* submsg);
+
+// Getters
+
+UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTableSub_Enum(
+    upb_MiniTableSub sub);
+
+UPB_API_INLINE const upb_MiniTable* upb_MiniTableSub_Message(
+    upb_MiniTableSub sub);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+
+#endif /* UPB_MINI_TABLE_SUB_H_ */
+
 // Export the newer headers, for legacy users.  New users should include the
 // more specific headers directly.
 // IWYU pragma: begin_exports
--- a/rust/test/shared/accessors_test.rs
+++ b/rust/test/shared/accessors_test.rs
@ -8,7 +8,7 @@
 //! Tests covering accessors for singular bool, int32, int64, and bytes fields.

 use googletest::prelude::*;
-use protobuf::{MutProxy, Optional};
+use protobuf::Optional;
 use unittest_proto::{test_all_types, TestAllTypes};

 #[test]
@ -498,15 +498,13 @@ fn test_nonempty_default_string_accessors() {

 #[test]
 fn test_singular_msg_field() {
-    use test_all_types::*;
-
    let mut msg = TestAllTypes::new();
    let msg_view = msg.optional_nested_message();
    // testing reading an int inside a view
    assert_that!(msg_view.bb(), eq(0));

    assert_that!(msg.has_optional_nested_message(), eq(false));
-    let mut nested_msg_mut = msg.optional_nested_message_mut();
+    let nested_msg_mut = msg.optional_nested_message_mut();
    // test reading an int inside a mut
    assert_that!(nested_msg_mut.bb(), eq(0));

@ -780,3 +778,27 @@ fn test_submsg_setter() {

    assert_that!(parent.optional_nested_message().bb(), eq(7));
 }
+
+#[test]
+fn test_to_owned() {
+    let mut m = TestAllTypes::new();
+    m.set_optional_int32(42);
+    let clone = m.as_view().to_owned();
+    assert_that!(clone.optional_int32(), eq(42));
+
+    // to_owned should create a new message (modifying the original shouldn't affect
+    // the to_owned).
+    m.clear_optional_int32();
+    assert_that!(m.has_optional_int32(), eq(false));
+    assert_that!(clone.has_optional_int32(), eq(true));
+    assert_that!(clone.optional_int32(), eq(42));
+
+    let mut submsg_mut = m.optional_nested_message_mut();
+    submsg_mut.set_bb(7);
+    let submsg_clone = submsg_mut.to_owned();
+    assert_that!(submsg_clone.bb(), eq(7));
+    assert_that!(submsg_mut.bb(), eq(7));
+    submsg_mut.set_bb(8);
+    assert_that!(submsg_clone.bb(), eq(7));
+    assert_that!(submsg_mut.bb(), eq(8));
+}
--- a/src/google/protobuf/arena.h
+++ b/src/google/protobuf/arena.h
@ -142,7 +142,7 @@ struct ArenaOptions {
 // This is a thread-safe implementation: multiple threads may allocate from the
 // arena concurrently. Destruction is not thread-safe and the destructing
 // thread must synchronize with users of the arena first.
-class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
+class PROTOBUF_EXPORT alignas(8) Arena final {
 public:
  // Default constructor with sensible default options, tuned for average
  // use-cases.
--- a/src/google/protobuf/compiler/java/helpers.h
+++ b/src/google/protobuf/compiler/java/helpers.h
@ -78,8 +78,7 @@ std::string UniqueFileScopeIdentifier(const Descriptor* descriptor);
 // Gets the unqualified class name for the file.  For each .proto file, there
 // will be one Java class containing all the immutable messages and another
 // Java class containing all the mutable messages.
-// TODO: remove the default value after updating client code.
-std::string FileClassName(const FileDescriptor* file, bool immutable = true);
+std::string FileClassName(const FileDescriptor* file, bool immutable);

 // Returns the file's Java package name.
 std::string FileJavaPackage(const FileDescriptor* file, bool immutable,
--- a/src/google/protobuf/compiler/java/names.cc
+++ b/src/google/protobuf/compiler/java/names.cc
@ -39,16 +39,17 @@ const char* DefaultPackage(Options options) {
 bool IsReservedName(absl::string_view name) {
  static const auto& kReservedNames =
      *new absl::flat_hash_set<absl::string_view>({
-          "abstract",   "assert",       "boolean",   "break",      "byte",
-          "case",       "catch",        "char",      "class",      "const",
-          "continue",   "default",      "do",        "double",     "else",
-          "enum",       "extends",      "final",     "finally",    "float",
-          "for",        "goto",         "if",        "implements", "import",
-          "instanceof", "int",          "interface", "long",       "native",
-          "new",        "package",      "private",   "protected",  "public",
-          "return",     "short",        "static",    "strictfp",   "super",
-          "switch",     "synchronized", "this",      "throw",      "throws",
-          "transient",  "try",          "void",      "volatile",   "while",
+          "abstract",  "assert",     "boolean",   "break",        "byte",
+          "case",      "catch",      "char",      "class",        "const",
+          "continue",  "default",    "do",        "double",       "else",
+          "enum",      "extends",    "false",     "final",        "finally",
+          "float",     "for",        "goto",      "if",           "implements",
+          "import",    "instanceof", "int",       "interface",    "long",
+          "native",    "new",        "null",      "package",      "private",
+          "protected", "public",     "return",    "short",        "static",
+          "strictfp",  "super",      "switch",    "synchronized", "this",
+          "throw",     "throws",     "transient", "true",         "try",
+          "void",      "volatile",   "while",
      });
  return kReservedNames.contains(name);
 }
@ -140,6 +141,14 @@ std::string FileJavaPackage(const FileDescriptor* file, Options options) {
  return FileJavaPackage(file, true /* immutable */, options);
 }

+std::string JavaPackageDirectory(const FileDescriptor* file) {
+  return JavaPackageToDir(FileJavaPackage(file));
+}
+
+std::string FileClassName(const FileDescriptor* file) {
+  return FileClassName(file, /*immutable=*/true);
+}
+
 std::string CapitalizedFieldName(const FieldDescriptor* field) {
  return UnderscoresToCamelCase(FieldName(field), true);
 }
--- a/src/google/protobuf/compiler/java/names.h
+++ b/src/google/protobuf/compiler/java/names.h
@ -72,6 +72,20 @@ std::string ClassName(const ServiceDescriptor* descriptor);
 std::string FileJavaPackage(const FileDescriptor* descriptor,
                            Options options = {});

+// Requires:
+//   descriptor != NULL
+//
+// Returns:
+//   Java package directory.
+std::string JavaPackageDirectory(const FileDescriptor* file);
+
+// Requires:
+//   descriptor != NULL
+//
+// Returns:
+//   The unqualified Java class name.
+std::string FileClassName(const FileDescriptor* file);
+
 // Requires:
 //   descriptor != NULL
 // Returns:
--- a/src/google/protobuf/compiler/php/php_generator.cc
+++ b/src/google/protobuf/compiler/php/php_generator.cc
@ -1758,7 +1758,7 @@ void GenerateCMessage(const Descriptor* message, io::Printer* printer) {
        "  const upb_OneofDef *oneof = upb_MessageDef_FindOneofByName(\n"
        "      intern->desc->msgdef, \"$name$\");\n"
        "  const upb_FieldDef *field = \n"
-        "      upb_Message_WhichOneof(intern->msg, oneof);\n"
+        "      upb_Message_WhichOneofByDef(intern->msg, oneof);\n"
        "  RETURN_STRING(field ? upb_FieldDef_Name(field) : \"\");\n"
        "}\n",
        "c_name", c_name, "name", oneof->name(), "camel_name",
--- a/src/google/protobuf/compiler/php/php_generator.h
+++ b/src/google/protobuf/compiler/php/php_generator.h
@ -37,7 +37,13 @@ class PROTOC_EXPORT Generator : public CodeGenerator {
                   std::string* error) const override;

  uint64_t GetSupportedFeatures() const override {
-    return FEATURE_PROTO3_OPTIONAL;
+    return Feature::FEATURE_PROTO3_OPTIONAL;
+  }
+
+  Edition GetMinimumEdition() const override { return Edition::EDITION_PROTO2; }
+  Edition GetMaximumEdition() const override { return Edition::EDITION_2023; }
+  std::vector<const FieldDescriptor*> GetFeatureExtensions() const override {
+    return {};
  }

 private:
--- a/src/google/protobuf/compiler/rust/message.cc
+++ b/src/google/protobuf/compiler/rust/message.cc
@ -911,6 +911,10 @@ void GenerateRs(Context& ctx, const Descriptor& msg) {
            $Msg::serialize$
          }

+          pub fn to_owned(&self) -> $Msg$ {
+            $pb$::IntoProxied::into(*self, $pbi$::Private)
+          }
+
          $accessor_fns_for_views$
        }

@ -986,6 +990,10 @@ void GenerateRs(Context& ctx, const Descriptor& msg) {
            $pb$::ViewProxy::as_view(self).serialize()
          }

+          pub fn to_owned(&self) -> $Msg$ {
+            $pb$::ViewProxy::as_view(self).to_owned()
+          }
+
          $get_upb_minitable$

          $raw_arena_getter_for_msgmut$
--- a/src/google/protobuf/dynamic_message.cc
+++ b/src/google/protobuf/dynamic_message.cc
@ -620,6 +620,7 @@ DynamicMessageFactory::~DynamicMessageFactory() {
 }

 const Message* DynamicMessageFactory::GetPrototype(const Descriptor* type) {
+  ABSL_CHECK(type != nullptr);
  absl::MutexLock lock(&prototypes_mutex_);
  return GetPrototypeNoLock(type);
 }
--- a/src/google/protobuf/dynamic_message.h
+++ b/src/google/protobuf/dynamic_message.h
@ -108,8 +108,8 @@ class PROTOBUF_EXPORT DynamicMessageFactory : public MessageFactory {
  // prototype, so these must be destroyed before the DynamicMessageFactory
  // is destroyed.
  //
-  // The given descriptor must outlive the returned message, and hence must
-  // outlive the DynamicMessageFactory.
+  // The given descriptor must be non-null and outlive the returned message, and
+  // hence must outlive the DynamicMessageFactory.
  //
  // The method is thread-safe.
  const Message* GetPrototype(const Descriptor* type) override;
--- a/src/google/protobuf/lite_unittest.cc
+++ b/src/google/protobuf/lite_unittest.cc
@ -27,6 +27,7 @@
 #include "google/protobuf/io/zero_copy_stream_impl_lite.h"
 #include "google/protobuf/map_lite_test_util.h"
 #include "google/protobuf/map_lite_unittest.pb.h"
+#include "google/protobuf/message_lite.h"
 #include "google/protobuf/parse_context.h"
 #include "google/protobuf/test_util_lite.h"
 #include "google/protobuf/unittest_lite.pb.h"
@ -1325,6 +1326,92 @@ TEST(LiteBasicTest, CodedInputStreamRollback) {
  }
 }

+// Two arbitary types
+using CastType1 = protobuf_unittest::TestAllTypesLite;
+using CastType2 = protobuf_unittest::TestPackedTypesLite;
+
+TEST(LiteTest, DynamicCastToGenerated) {
+  CastType1 test_type_1;
+
+  MessageLite* test_type_1_pointer = &test_type_1;
+  EXPECT_EQ(&test_type_1,
+            DynamicCastToGenerated<CastType1>(test_type_1_pointer));
+  EXPECT_EQ(nullptr, DynamicCastToGenerated<CastType2>(test_type_1_pointer));
+
+  const MessageLite* test_type_1_pointer_const = &test_type_1;
+  EXPECT_EQ(&test_type_1,
+            DynamicCastToGenerated<const CastType1>(test_type_1_pointer_const));
+  EXPECT_EQ(nullptr,
+            DynamicCastToGenerated<const CastType2>(test_type_1_pointer_const));
+
+  MessageLite* test_type_1_pointer_nullptr = nullptr;
+  EXPECT_EQ(nullptr,
+            DynamicCastToGenerated<CastType1>(test_type_1_pointer_nullptr));
+
+  MessageLite& test_type_1_pointer_ref = test_type_1;
+  EXPECT_EQ(&test_type_1,
+            &DynamicCastToGenerated<CastType1>(test_type_1_pointer_ref));
+
+  const MessageLite& test_type_1_pointer_const_ref = test_type_1;
+  EXPECT_EQ(&test_type_1,
+            &DynamicCastToGenerated<CastType1>(test_type_1_pointer_const_ref));
+}
+
+#if GTEST_HAS_DEATH_TEST
+TEST(LiteTest, DynamicCastToGeneratedInvalidReferenceType) {
+  CastType1 test_type_1;
+  const MessageLite& test_type_1_pointer_const_ref = test_type_1;
+  ASSERT_DEATH(DynamicCastToGenerated<CastType2>(test_type_1_pointer_const_ref),
+               "Cannot downcast " + test_type_1.GetTypeName() + " to " +
+                   CastType2::default_instance().GetTypeName());
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+TEST(LiteTest, DownCastToGeneratedValidType) {
+  CastType1 test_type_1;
+
+  MessageLite* test_type_1_pointer = &test_type_1;
+  EXPECT_EQ(&test_type_1, DownCastToGenerated<CastType1>(test_type_1_pointer));
+
+  const MessageLite* test_type_1_pointer_const = &test_type_1;
+  EXPECT_EQ(&test_type_1,
+            DownCastToGenerated<const CastType1>(test_type_1_pointer_const));
+
+  MessageLite* test_type_1_pointer_nullptr = nullptr;
+  EXPECT_EQ(nullptr,
+            DownCastToGenerated<CastType1>(test_type_1_pointer_nullptr));
+
+  MessageLite& test_type_1_pointer_ref = test_type_1;
+  EXPECT_EQ(&test_type_1,
+            &DownCastToGenerated<CastType1>(test_type_1_pointer_ref));
+
+  const MessageLite& test_type_1_pointer_const_ref = test_type_1;
+  EXPECT_EQ(&test_type_1,
+            &DownCastToGenerated<CastType1>(test_type_1_pointer_const_ref));
+}
+
+#if GTEST_HAS_DEATH_TEST
+TEST(LiteTest, DownCastToGeneratedInvalidPointerType) {
+  CastType1 test_type_1;
+
+  MessageLite* test_type_1_pointer = &test_type_1;
+
+  ASSERT_DEBUG_DEATH(DownCastToGenerated<CastType2>(test_type_1_pointer),
+                     "Cannot downcast " + test_type_1.GetTypeName() + " to " +
+                         CastType2::default_instance().GetTypeName());
+}
+
+TEST(LiteTest, DownCastToGeneratedInvalidReferenceType) {
+  CastType1 test_type_1;
+
+  MessageLite& test_type_1_pointer = test_type_1;
+
+  ASSERT_DEBUG_DEATH(DownCastToGenerated<CastType2>(test_type_1_pointer),
+                     "Cannot downcast " + test_type_1.GetTypeName() + " to " +
+                         CastType2::default_instance().GetTypeName());
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
 }  // namespace
 }  // namespace protobuf
 }  // namespace google
--- a/src/google/protobuf/message.h
+++ b/src/google/protobuf/message.h
@ -1424,90 +1424,6 @@ DECLARE_GET_REPEATED_FIELD(bool)

 #undef DECLARE_GET_REPEATED_FIELD

-// Tries to downcast this message to a generated message type.  Returns nullptr
-// if this class is not an instance of T.  This works even if RTTI is disabled.
-//
-// This also has the effect of creating a strong reference to T that will
-// prevent the linker from stripping it out at link time.  This can be important
-// if you are using a DynamicMessageFactory that delegates to the generated
-// factory.
-template <typename T>
-const T* DynamicCastToGenerated(const Message* from) {
-  // Compile-time assert that T is a generated type that has a
-  // default_instance() accessor, but avoid actually calling it.
-  const T& (*get_default_instance)() = &T::default_instance;
-  (void)get_default_instance;
-
-  // Compile-time assert that T is a subclass of google::protobuf::Message.
-  const Message* unused = static_cast<T*>(nullptr);
-  (void)unused;
-
-#if PROTOBUF_RTTI
-  internal::StrongReferenceToType<T>();
-  return dynamic_cast<const T*>(from);
-#else
-  bool ok = from != nullptr &&
-            T::default_instance().GetReflection() == from->GetReflection();
-  return ok ? internal::DownCast<const T*>(from) : nullptr;
-#endif
-}
-
-template <typename T>
-T* DynamicCastToGenerated(Message* from) {
-  const Message* message_const = from;
-  return const_cast<T*>(DynamicCastToGenerated<T>(message_const));
-}
-
-// An overloaded version of DynamicCastToGenerated for downcasting references to
-// base Message class. If the destination type T if the argument is not an
-// instance of T and dynamic_cast returns nullptr, it terminates with an error.
-template <typename T>
-const T& DynamicCastToGenerated(const Message& from) {
-  const T* destination_message = DynamicCastToGenerated<T>(&from);
-  ABSL_CHECK(destination_message != nullptr)
-      << "Cannot downcast " << from.GetTypeName() << " to "
-      << T::default_instance().GetTypeName();
-  return *destination_message;
-}
-
-template <typename T>
-T& DynamicCastToGenerated(Message& from) {
-  const Message& message_const = from;
-  const T& destination_message = DynamicCastToGenerated<T>(message_const);
-  return const_cast<T&>(destination_message);
-}
-
-// A lightweight function for downcasting base Message pointer to derived type.
-// It should only be used when the caller is certain that the argument is of
-// instance T and T is a type derived from base Message class.
-template <typename T>
-const T* DownCastToGenerated(const Message* from) {
-  internal::StrongReferenceToType<T>();
-  ABSL_DCHECK(DynamicCastToGenerated<T>(from) == from)
-      << "Cannot downcast " << from->GetTypeName() << " to "
-      << T::default_instance().GetTypeName();
-
-  return static_cast<const T*>(from);
-}
-
-template <typename T>
-T* DownCastToGenerated(Message* from) {
-  const Message* message_const = from;
-  return const_cast<T*>(DownCastToGenerated<T>(message_const));
-}
-
-template <typename T>
-const T& DownCastToGenerated(const Message& from) {
-  return *DownCastToGenerated<T>(&from);
-}
-
-template <typename T>
-T& DownCastToGenerated(Message& from) {
-  const Message& message_const = from;
-  const T& destination_message = DownCastToGenerated<T>(message_const);
-  return const_cast<T&>(destination_message);
-}
-
 // Call this function to ensure that this message's reflection is linked into
 // the binary:
 //
--- a/src/google/protobuf/message_lite.h
+++ b/src/google/protobuf/message_lite.h
@ -21,6 +21,7 @@
 #include <cstdint>
 #include <iosfwd>
 #include <string>
+#include <type_traits>

 #include "absl/base/attributes.h"
 #include "absl/log/absl_check.h"
@ -53,6 +54,7 @@ class FastReflectionStringSetter;
 class Reflection;
 class Descriptor;
 class AssignDescriptorsHelper;
+class MessageLite;

 namespace io {

@ -120,6 +122,9 @@ class PROTOBUF_EXPORT CachedSize {
 #endif
 };

+// For MessageLite to friend.
+class TypeId;
+
 class SwapFieldHelper;

 // See parse_context.h for explanation
@ -638,6 +643,15 @@ class PROTOBUF_EXPORT MessageLite {
  // return a default table instead of a unique one.
  virtual const ClassData* GetClassData() const = 0;

+  template <typename T>
+  static auto GetClassDataGenerated() {
+    // We could speed this up if needed by avoiding the function call.
+    // In LTO this is likely inlined, so it might not matter.
+    static_assert(
+        std::is_same<const T&, decltype(T::default_instance())>::value, "");
+    return T::default_instance().T::GetClassData();
+  }
+
  internal::InternalMetadata _internal_metadata_;

  // Return the cached size object as described by
@ -682,6 +696,7 @@ class PROTOBUF_EXPORT MessageLite {
  friend class internal::LazyField;
  friend class internal::SwapFieldHelper;
  friend class internal::TcParser;
+  friend class internal::TypeId;
  friend class internal::WeakFieldMap;
  friend class internal::WireFormatLite;

@ -717,6 +732,32 @@ class PROTOBUF_EXPORT MessageLite {

 namespace internal {

+// A typeinfo equivalent for protobuf message types. Used for
+// DynamicCastToGenerated.
+// We might make this class public later on to have an alternative to
+// `std::type_info` that works when RTTI is disabled.
+class TypeId {
+ public:
+  constexpr explicit TypeId(const MessageLite::ClassData* data) : data_(data) {}
+
+  friend constexpr bool operator==(TypeId a, TypeId b) {
+    return a.data_ == b.data_;
+  }
+  friend constexpr bool operator!=(TypeId a, TypeId b) { return !(a == b); }
+
+  static TypeId Get(const MessageLite& msg) {
+    return TypeId(msg.GetClassData());
+  }
+
+  template <typename T>
+  static TypeId Get() {
+    return TypeId(MessageLite::GetClassDataGenerated<T>());
+  }
+
+ private:
+  const MessageLite::ClassData* data_;
+};
+
 template <bool alias>
 bool MergeFromImpl(absl::string_view input, MessageLite* msg,
                   const internal::TcParseTableBase* tc_table,
@ -820,6 +861,83 @@ T* OnShutdownDelete(T* p) {
 std::string ShortFormat(const MessageLite& message_lite);
 std::string Utf8Format(const MessageLite& message_lite);

+// Tries to downcast this message to a generated message type.  Returns nullptr
+// if this class is not an instance of T.  This works even if RTTI is disabled.
+//
+// This also has the effect of creating a strong reference to T that will
+// prevent the linker from stripping it out at link time.  This can be important
+// if you are using a DynamicMessageFactory that delegates to the generated
+// factory.
+template <typename T>
+const T* DynamicCastToGenerated(const MessageLite* from) {
+  static_assert(std::is_base_of<MessageLite, T>::value, "");
+
+  internal::StrongReferenceToType<T>();
+  // We might avoid the call to T::GetClassData() altogether if T were to
+  // expose the class data pointer.
+  if (from == nullptr ||
+      internal::TypeId::Get<T>() != internal::TypeId::Get(*from)) {
+    return nullptr;
+  }
+
+  return static_cast<const T*>(from);
+}
+
+template <typename T>
+const T* DynamicCastToGenerated(const MessageLite* from);
+
+template <typename T>
+T* DynamicCastToGenerated(MessageLite* from) {
+  return const_cast<T*>(
+      DynamicCastToGenerated<T>(static_cast<const MessageLite*>(from)));
+}
+
+// An overloaded version of DynamicCastToGenerated for downcasting references to
+// base Message class. If the argument is not an instance of T, it terminates
+// with an error.
+template <typename T>
+const T& DynamicCastToGenerated(const MessageLite& from) {
+  const T* destination_message = DynamicCastToGenerated<T>(&from);
+  ABSL_CHECK(destination_message != nullptr)
+      << "Cannot downcast " << from.GetTypeName() << " to "
+      << T::default_instance().GetTypeName();
+  return *destination_message;
+}
+
+template <typename T>
+T& DynamicCastToGenerated(MessageLite& from) {
+  return const_cast<T&>(
+      DynamicCastToGenerated<T>(static_cast<const MessageLite&>(from)));
+}
+
+// A lightweight function for downcasting base MessageLite pointer to derived
+// type. It should only be used when the caller is certain that the argument is
+// of instance T and T is a generated message type.
+template <typename T>
+const T* DownCastToGenerated(const MessageLite* from) {
+  internal::StrongReferenceToType<T>();
+  ABSL_DCHECK(DynamicCastToGenerated<T>(from) == from)
+      << "Cannot downcast " << from->GetTypeName() << " to "
+      << T::default_instance().GetTypeName();
+  return static_cast<const T*>(from);
+}
+
+template <typename T>
+T* DownCastToGenerated(MessageLite* from) {
+  return const_cast<T*>(
+      DownCastToGenerated<T>(static_cast<const MessageLite*>(from)));
+}
+
+template <typename T>
+const T& DownCastToGenerated(const MessageLite& from) {
+  return *DownCastToGenerated<T>(&from);
+}
+
+template <typename T>
+T& DownCastToGenerated(MessageLite& from) {
+  return *DownCastToGenerated<T>(&from);
+}
+
 }  // namespace protobuf
 }  // namespace google

--- a/src/google/protobuf/message_unittest.inc
+++ b/src/google/protobuf/message_unittest.inc
@ -753,35 +753,35 @@ TEST(MESSAGE_TEST_NAME, InitializationErrorString) {
 TEST(MESSAGE_TEST_NAME, DynamicCastToGenerated) {
  UNITTEST::TestAllTypes test_all_types;

-  Message* test_all_types_pointer = &test_all_types;
+  MessageLite* test_all_types_pointer = &test_all_types;
  EXPECT_EQ(&test_all_types, DynamicCastToGenerated<UNITTEST::TestAllTypes>(
                                 test_all_types_pointer));
  EXPECT_EQ(nullptr, DynamicCastToGenerated<UNITTEST::TestRequired>(
                         test_all_types_pointer));

-  const Message* test_all_types_pointer_const = &test_all_types;
+  const MessageLite* test_all_types_pointer_const = &test_all_types;
  EXPECT_EQ(&test_all_types,
            DynamicCastToGenerated<const UNITTEST::TestAllTypes>(
                test_all_types_pointer_const));
  EXPECT_EQ(nullptr, DynamicCastToGenerated<const UNITTEST::TestRequired>(
                         test_all_types_pointer_const));

-  Message* test_all_types_pointer_nullptr = nullptr;
+  MessageLite* test_all_types_pointer_nullptr = nullptr;
  EXPECT_EQ(nullptr, DynamicCastToGenerated<UNITTEST::TestAllTypes>(
                         test_all_types_pointer_nullptr));

-  Message& test_all_types_pointer_ref = test_all_types;
+  MessageLite& test_all_types_pointer_ref = test_all_types;
  EXPECT_EQ(&test_all_types, &DynamicCastToGenerated<UNITTEST::TestAllTypes>(
                                 test_all_types_pointer_ref));

-  const Message& test_all_types_pointer_const_ref = test_all_types;
+  const MessageLite& test_all_types_pointer_const_ref = test_all_types;
  EXPECT_EQ(&test_all_types, &DynamicCastToGenerated<UNITTEST::TestAllTypes>(
                                 test_all_types_pointer_const_ref));
 }

 TEST(MESSAGE_TEST_NAME, DynamicCastToGeneratedInvalidReferenceType) {
  UNITTEST::TestAllTypes test_all_types;
-  const Message& test_all_types_pointer_const_ref = test_all_types;
+  const MessageLite& test_all_types_pointer_const_ref = test_all_types;
  ASSERT_DEATH(DynamicCastToGenerated<UNITTEST::TestRequired>(
                   test_all_types_pointer_const_ref),
               "Cannot downcast " + test_all_types.GetTypeName() + " to " +
@ -791,23 +791,23 @@ TEST(MESSAGE_TEST_NAME, DynamicCastToGeneratedInvalidReferenceType) {
 TEST(MESSAGE_TEST_NAME, DownCastToGeneratedValidType) {
  UNITTEST::TestAllTypes test_all_types;

-  Message* test_all_types_pointer = &test_all_types;
+  MessageLite* test_all_types_pointer = &test_all_types;
  EXPECT_EQ(&test_all_types, DownCastToGenerated<UNITTEST::TestAllTypes>(
                                 test_all_types_pointer));

-  const Message* test_all_types_pointer_const = &test_all_types;
+  const MessageLite* test_all_types_pointer_const = &test_all_types;
  EXPECT_EQ(&test_all_types, DownCastToGenerated<const UNITTEST::TestAllTypes>(
                                 test_all_types_pointer_const));

-  Message* test_all_types_pointer_nullptr = nullptr;
+  MessageLite* test_all_types_pointer_nullptr = nullptr;
  EXPECT_EQ(nullptr, DownCastToGenerated<UNITTEST::TestAllTypes>(
                         test_all_types_pointer_nullptr));

-  Message& test_all_types_pointer_ref = test_all_types;
+  MessageLite& test_all_types_pointer_ref = test_all_types;
  EXPECT_EQ(&test_all_types, &DownCastToGenerated<UNITTEST::TestAllTypes>(
                                 test_all_types_pointer_ref));

-  const Message& test_all_types_pointer_const_ref = test_all_types;
+  const MessageLite& test_all_types_pointer_const_ref = test_all_types;
  EXPECT_EQ(&test_all_types, &DownCastToGenerated<UNITTEST::TestAllTypes>(
                                 test_all_types_pointer_const_ref));
 }
@ -815,7 +815,7 @@ TEST(MESSAGE_TEST_NAME, DownCastToGeneratedValidType) {
 TEST(MESSAGE_TEST_NAME, DownCastToGeneratedInvalidPointerType) {
  UNITTEST::TestAllTypes test_all_types;

-  Message* test_all_types_pointer = &test_all_types;
+  MessageLite* test_all_types_pointer = &test_all_types;

  ASSERT_DEBUG_DEATH(
      DownCastToGenerated<UNITTEST::TestRequired>(test_all_types_pointer),
@ -826,7 +826,7 @@ TEST(MESSAGE_TEST_NAME, DownCastToGeneratedInvalidPointerType) {
 TEST(MESSAGE_TEST_NAME, DownCastToGeneratedInvalidReferenceType) {
  UNITTEST::TestAllTypes test_all_types;

-  Message& test_all_types_pointer = test_all_types;
+  MessageLite& test_all_types_pointer = test_all_types;

  ASSERT_DEBUG_DEATH(
      DownCastToGenerated<UNITTEST::TestRequired>(test_all_types_pointer),
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@ -403,39 +403,6 @@ static_assert(PROTOBUF_ABSL_MIN(20230125, 3),
 #error PROTOBUF_FORCE_ALLOCATION_ON_CONSTRUCTION was previously defined
 #endif

-// Specify memory alignment for structs, classes, etc.
-// Use like:
-//   class PROTOBUF_ALIGNAS(16) MyClass { ... }
-//   PROTOBUF_ALIGNAS(16) int array[4];
-//
-// In most places you can use the C++11 keyword "alignas", which is preferred.
-//
-// But compilers have trouble mixing __attribute__((...)) syntax with
-// alignas(...) syntax.
-//
-// Doesn't work in clang or gcc:
-//   struct alignas(16) __attribute__((packed)) S { char c; };
-// Works in clang but not gcc:
-//   struct __attribute__((packed)) alignas(16) S2 { char c; };
-// Works in clang and gcc:
-//   struct alignas(16) S3 { char c; } __attribute__((packed));
-//
-// There are also some attributes that must be specified *before* a class
-// definition: visibility (used for exporting functions/classes) is one of
-// these attributes. This means that it is not possible to use alignas() with a
-// class that is marked as exported.
-#ifdef PROTOBUF_ALIGNAS
-#error PROTOBUF_ALIGNAS was previously defined
-#endif
-#if defined(_MSC_VER)
-#define PROTOBUF_ALIGNAS(byte_alignment) __declspec(align(byte_alignment))
-#elif defined(__GNUC__)
-#define PROTOBUF_ALIGNAS(byte_alignment) \
-  __attribute__((aligned(byte_alignment)))
-#else
-#define PROTOBUF_ALIGNAS(byte_alignment) alignas(byte_alignment)
-#endif
-
 #ifdef PROTOBUF_THREAD_LOCAL
 #error PROTOBUF_THREAD_LOCAL was previously defined
 #endif
@ -597,13 +564,6 @@ static_assert(PROTOBUF_ABSL_MIN(20230125, 3),
 #define PROTOBUF_TSAN_DECLARE_MEMBER
 #endif

-#ifdef PROTOBUF_USE_TABLE_PARSER_ON_REFLECTION
-#error PROTOBUF_USE_TABLE_PARSER_ON_REFLECTION was previously defined
-#endif
-#if !defined(PROTOBUF_TEMPORARY_DISABLE_TABLE_PARSER_ON_REFLECTION)
-#define PROTOBUF_USE_TABLE_PARSER_ON_REFLECTION 1
-#endif  // PROTOBUF_ENABLE_FORCE_ALLOCATION_ON_CONSTRUCTION
-
 // Note that this is performance sensitive: changing the parameters will change
 // the registers used by the ABI calling convention, which subsequently affects
 // register selection logic inside the function.
--- a/src/google/protobuf/port_undef.inc
+++ b/src/google/protobuf/port_undef.inc
@ -50,7 +50,6 @@
 #undef PROTOBUF_ASSUME
 #undef PROTOBUF_EXPORT_TEMPLATE_DECLARE
 #undef PROTOBUF_EXPORT_TEMPLATE_DEFINE
-#undef PROTOBUF_ALIGNAS
 #undef PROTOBUF_THREAD_LOCAL
 #undef PROTOBUF_CONSTINIT
 #undef PROTOBUF_CONSTEXPR
@ -65,7 +64,6 @@
 #undef PROTOBUF_MSAN
 #undef PROTOBUF_TSAN
 #undef PROTOBUF_TSAN_DECLARE_MEMBER
-#undef PROTOBUF_USE_TABLE_PARSER_ON_REFLECTION
 #undef PROTOBUF_BUILTIN_CONSTANT_P
 #undef PROTOBUF_DESCRIPTOR_WEAK_MESSAGES_ALLOWED
 #undef PROTOBUF_PREFETCH_PARSE_TABLE
--- a/src/google/protobuf/wire_format.cc
+++ b/src/google/protobuf/wire_format.cc
@ -766,6 +766,44 @@ struct WireFormat::MessageSetParser {
  const Reflection* reflection;
 };

+static const char* HandleMessage(Message* msg, const char* ptr,
+                                 internal::ParseContext* ctx, uint64_t tag,
+                                 const Reflection* reflection,
+                                 const FieldDescriptor* field) {
+  Message* sub_message;
+  if (field->is_repeated()) {
+    sub_message = reflection->AddMessage(msg, field, ctx->data().factory);
+  } else {
+    sub_message = reflection->MutableMessage(msg, field, ctx->data().factory);
+  }
+
+  if (WireFormatLite::GetTagWireType(tag) ==
+      WireFormatLite::WIRETYPE_START_GROUP) {
+    return ctx->ParseGroup(sub_message, ptr, tag);
+  } else {
+    ABSL_DCHECK(WireFormatLite::GetTagWireType(tag) ==
+                WireFormatLite::WIRETYPE_LENGTH_DELIMITED);
+  }
+
+  ptr = ctx->ParseMessage(sub_message, ptr);
+
+  // For map entries, if the value is an unknown enum we have to push it
+  // into the unknown field set and remove it from the list.
+  if (ptr != nullptr && field->is_map()) {
+    auto* value_field = field->message_type()->map_value();
+    auto* enum_type = value_field->enum_type();
+    if (enum_type != nullptr &&
+        !internal::cpp::HasPreservingUnknownEnumSemantics(value_field) &&
+        enum_type->FindValueByNumber(sub_message->GetReflection()->GetEnumValue(
+            *sub_message, value_field)) == nullptr) {
+      reflection->MutableUnknownFields(msg)->AddLengthDelimited(
+          field->number(), sub_message->SerializeAsString());
+      reflection->RemoveLast(msg, field);
+    }
+  }
+  return ptr;
+}
+
 const char* WireFormat::_InternalParse(Message* msg, const char* ptr,
                                       internal::ParseContext* ctx) {
  const Descriptor* descriptor = msg->GetDescriptor();
@ -995,46 +1033,9 @@ const char* WireFormat::_InternalParseAndMergeField(
      return ptr;
    }

-    case FieldDescriptor::TYPE_GROUP: {
-      Message* sub_message;
-      if (field->is_repeated()) {
-        sub_message = reflection->AddMessage(msg, field, ctx->data().factory);
-      } else {
-        sub_message =
-            reflection->MutableMessage(msg, field, ctx->data().factory);
-      }
-
-      return ctx->ParseGroup(sub_message, ptr, tag);
-    }
-
-    case FieldDescriptor::TYPE_MESSAGE: {
-      Message* sub_message;
-      if (field->is_repeated()) {
-        sub_message = reflection->AddMessage(msg, field, ctx->data().factory);
-      } else {
-        sub_message =
-            reflection->MutableMessage(msg, field, ctx->data().factory);
-      }
-      ptr = ctx->ParseMessage(sub_message, ptr);
-
-      // For map entries, if the value is an unknown enum we have to push it
-      // into the unknown field set and remove it from the list.
-      if (ptr != nullptr && field->is_map()) {
-        auto* value_field = field->message_type()->map_value();
-        auto* enum_type = value_field->enum_type();
-        if (enum_type != nullptr &&
-            !internal::cpp::HasPreservingUnknownEnumSemantics(value_field) &&
-            enum_type->FindValueByNumber(
-                sub_message->GetReflection()->GetEnumValue(
-                    *sub_message, value_field)) == nullptr) {
-          reflection->MutableUnknownFields(msg)->AddLengthDelimited(
-              field->number(), sub_message->SerializeAsString());
-          reflection->RemoveLast(msg, field);
-        }
-      }
-
-      return ptr;
-    }
+    case FieldDescriptor::TYPE_MESSAGE:
+    case FieldDescriptor::TYPE_GROUP:
+      return HandleMessage(msg, ptr, ctx, tag, reflection, field);
  }

  // GCC 8 complains about control reaching end of non-void function here.
--- a/upb/json/decode.c
+++ b/upb/json/decode.c
@ -957,7 +957,7 @@ static void jsondec_field(jsondec* d, upb_Message* msg,
  }

  if (upb_FieldDef_RealContainingOneof(f) &&
-      upb_Message_WhichOneof(msg, upb_FieldDef_ContainingOneof(f))) {
+      upb_Message_WhichOneofByDef(msg, upb_FieldDef_ContainingOneof(f))) {
    jsondec_err(d, "More than one field for this oneof.");
  }

--- a/upb/message/accessors.h
+++ b/upb/message/accessors.h
@ -8,30 +8,17 @@
 #ifndef UPB_MESSAGE_ACCESSORS_H_
 #define UPB_MESSAGE_ACCESSORS_H_

-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include "upb/base/descriptor_constants.h"
 #include "upb/base/string_view.h"
 #include "upb/mem/arena.h"
 #include "upb/message/array.h"
 #include "upb/message/internal/accessors.h"
-#include "upb/message/internal/array.h"
-#include "upb/message/internal/map.h"
-#include "upb/message/internal/message.h"
-#include "upb/message/internal/tagged_ptr.h"
 #include "upb/message/map.h"
 #include "upb/message/message.h"
 #include "upb/message/tagged_ptr.h"
 #include "upb/message/value.h"
-#include "upb/mini_table/enum.h"
 #include "upb/mini_table/extension.h"
 #include "upb/mini_table/field.h"
-#include "upb/mini_table/internal/field.h"
-#include "upb/mini_table/internal/message.h"
 #include "upb/mini_table/message.h"
-#include "upb/mini_table/sub.h"

 // Must be last.
 #include "upb/port/def.inc"
@ -76,6 +63,10 @@ UPB_API_INLINE upb_MessageValue
 upb_Message_GetField(const upb_Message* msg, const upb_MiniTableField* f,
                     upb_MessageValue default_val);

+UPB_API_INLINE upb_TaggedMessagePtr upb_Message_GetTaggedMessagePtr(
+    const upb_Message* msg, const upb_MiniTableField* field,
+    upb_Message* default_val);
+
 UPB_API_INLINE const upb_Array* upb_Message_GetArray(
    const upb_Message* msg, const upb_MiniTableField* f);

@ -102,12 +93,18 @@ UPB_API_INLINE int64_t upb_Message_GetInt64(const upb_Message* msg,
 UPB_API_INLINE const upb_Map* upb_Message_GetMap(const upb_Message* msg,
                                                 const upb_MiniTableField* f);

+UPB_API_INLINE const upb_Message* upb_Message_GetMessage(
+    const upb_Message* msg, const upb_MiniTableField* f);
+
 UPB_API_INLINE upb_Array* upb_Message_GetMutableArray(
    upb_Message* msg, const upb_MiniTableField* f);

 UPB_API_INLINE upb_Map* upb_Message_GetMutableMap(upb_Message* msg,
                                                  const upb_MiniTableField* f);

+UPB_API_INLINE upb_Message* upb_Message_GetMutableMessage(
+    upb_Message* msg, const upb_MiniTableField* f);
+
 UPB_API_INLINE upb_Array* upb_Message_GetOrCreateMutableArray(
    upb_Message* msg, const upb_MiniTableField* f, upb_Arena* arena);

@ -155,6 +152,10 @@ UPB_API_INLINE bool upb_Message_SetInt64(upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int64_t value, upb_Arena* a);

+UPB_API_INLINE void upb_Message_SetMessage(upb_Message* msg,
+                                           const upb_MiniTableField* f,
+                                           upb_Message* value);
+
 UPB_API_INLINE bool upb_Message_SetString(upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          upb_StringView value, upb_Arena* a);
@ -167,55 +168,6 @@ UPB_API_INLINE bool upb_Message_SetUInt64(upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint64_t value, upb_Arena* a);

-UPB_API_INLINE upb_TaggedMessagePtr upb_Message_GetTaggedMessagePtr(
-    const upb_Message* msg, const upb_MiniTableField* field,
-    upb_Message* default_val) {
-  UPB_ASSUME(upb_MiniTableField_CType(field) == kUpb_CType_Message);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(field) ==
-             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
-  UPB_ASSUME(upb_MiniTableField_IsScalar(field));
-  upb_TaggedMessagePtr tagged;
-  _upb_Message_GetNonExtensionField(msg, field, &default_val, &tagged);
-  return tagged;
-}
-
-UPB_API_INLINE const upb_Message* upb_Message_GetMessage(
-    const upb_Message* msg, const upb_MiniTableField* field) {
-  upb_TaggedMessagePtr tagged =
-      upb_Message_GetTaggedMessagePtr(msg, field, NULL);
-  return upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
-}
-
-UPB_API_INLINE upb_Message* upb_Message_GetMutableMessage(
-    upb_Message* msg, const upb_MiniTableField* field) {
-  return (upb_Message*)upb_Message_GetMessage(msg, field);
-}
-
-// For internal use only; users cannot set tagged messages because only the
-// parser and the message copier are allowed to directly create an empty
-// message.
-UPB_INLINE void UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)(
-    struct upb_Message* msg, const upb_MiniTable* mini_table,
-    const upb_MiniTableField* f, upb_TaggedMessagePtr sub_message) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
-             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_Message_SetBaseField(msg, f, &sub_message);
-}
-
-// Sets the value of a message-typed field. The `mini_table` and `field`
-// parameters belong to `msg`, not `sub_message`. The mini_tables of `msg` and
-// `sub_message` must have been linked for this to work correctly.
-UPB_API_INLINE void upb_Message_SetMessage(upb_Message* msg,
-                                           const upb_MiniTable* mini_table,
-                                           const upb_MiniTableField* field,
-                                           upb_Message* sub_message) {
-  UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
-  (msg, mini_table, field,
-   UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(sub_message, false));
-}
-
 UPB_API_INLINE void* upb_Message_ResizeArrayUninitialized(
    upb_Message* msg, const upb_MiniTableField* f, size_t size,
    upb_Arena* arena);
--- a/upb/message/accessors_test.cc
+++ b/upb/message/accessors_test.cc
@ -329,10 +329,8 @@ TEST(GeneratedCode, SubMessage) {
          arena));
  upb_Message_SetInt32(new_nested_message, nested_message_a_field, 123,
                       nullptr);
-  upb_Message_SetMessage(
-      UPB_UPCAST(msg),
-      &protobuf_0test_0messages__proto2__TestAllTypesProto2_msg_init,
-      optional_message_field, new_nested_message);
+  upb_Message_SetMessage(UPB_UPCAST(msg), optional_message_field,
+                         new_nested_message);

  upb_Message* mutable_message = upb_Message_GetOrCreateMutableMessage(
      UPB_UPCAST(msg),
--- a/upb/message/copy.c
+++ b/upb/message/copy.c
@ -215,7 +215,7 @@ upb_Message* _upb_Message_Copy(upb_Message* dst, const upb_Message* src,
              return NULL;
            }
            UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
-            (dst, mini_table, field,
+            (dst, field,
             UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(dst_sub_message,
                                                     is_empty));
          }
--- a/upb/message/copy_test.cc
+++ b/upb/message/copy_test.cc
@ -108,10 +108,8 @@ TEST(GeneratedCode, DeepCloneMessageSubMessage) {
          source_arena);
  protobuf_test_messages_proto2_TestAllTypesProto2_NestedMessage_set_a(
      nested, kTestNestedInt32);
-  upb_Message_SetMessage(
-      UPB_UPCAST(msg),
-      &protobuf_0test_0messages__proto2__TestAllTypesProto2_msg_init,
-      nested_message_field, UPB_UPCAST(nested));
+  upb_Message_SetMessage(UPB_UPCAST(msg), nested_message_field,
+                         UPB_UPCAST(nested));
  upb_Arena* arena = upb_Arena_New();
  protobuf_test_messages_proto2_TestAllTypesProto2* clone =
      (protobuf_test_messages_proto2_TestAllTypesProto2*)upb_Message_DeepClone(
--- a/upb/message/internal/accessors.h
+++ b/upb/message/internal/accessors.h
@ -220,7 +220,6 @@ UPB_INLINE bool UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(
 //                                       const upb_MiniTableField* field,
 //                                       bool value, upb_Arena* a) {
 //     UPB_ASSUME(field->UPB_PRIVATE(descriptortype) == kUpb_FieldType_Bool);
-//     UPB_ASSUME(upb_MiniTableField_IsScalar(field));
 //     UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(field) ==
 //                kUpb_FieldRep_1Byte);
 //     upb_Message_SetField(msg, field, &value, a);
@ -351,8 +350,8 @@ UPB_API_INLINE bool upb_Message_GetBool(const struct upb_Message* msg,
                                        const upb_MiniTableField* f,
                                        bool default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Bool);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  upb_MessageValue def;
  def.bool_val = default_val;
  return upb_Message_GetField(msg, f, def).bool_val;
@ -362,8 +361,8 @@ UPB_API_INLINE double upb_Message_GetDouble(const struct upb_Message* msg,
                                            const upb_MiniTableField* f,
                                            double default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.double_val = default_val;
@ -374,8 +373,8 @@ UPB_API_INLINE float upb_Message_GetFloat(const struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          float default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.float_val = default_val;
@ -387,8 +386,8 @@ UPB_API_INLINE int32_t upb_Message_GetInt32(const struct upb_Message* msg,
                                            int32_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.int32_val = default_val;
@ -399,8 +398,8 @@ UPB_API_INLINE int64_t upb_Message_GetInt64(const struct upb_Message* msg,
                                            const upb_MiniTableField* f,
                                            int64_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.int64_val = default_val;
@ -429,6 +428,37 @@ UPB_API_INLINE const struct upb_Map* upb_Message_GetMap(
  return ret;
 }

+UPB_API_INLINE uintptr_t upb_Message_GetTaggedMessagePtr(
+    const struct upb_Message* msg, const upb_MiniTableField* f,
+    struct upb_Message* default_val) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  uintptr_t tagged;
+  _upb_Message_GetNonExtensionField(msg, f, &default_val, &tagged);
+  return tagged;
+}
+
+// For internal use only; users cannot set tagged messages because only the
+// parser and the message copier are allowed to directly create an empty
+// message.
+UPB_INLINE void UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)(
+    struct upb_Message* msg, const upb_MiniTableField* f,
+    uintptr_t sub_message) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Message);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte));
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  upb_Message_SetBaseField(msg, f, &sub_message);
+}
+
+UPB_API_INLINE const struct upb_Message* upb_Message_GetMessage(
+    const struct upb_Message* msg, const upb_MiniTableField* f) {
+  uintptr_t tagged = upb_Message_GetTaggedMessagePtr(msg, f, NULL);
+  return upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
+}
+
 UPB_API_INLINE upb_Array* upb_Message_GetMutableArray(
    struct upb_Message* msg, const upb_MiniTableField* f) {
  UPB_PRIVATE(_upb_MiniTableField_CheckIsArray)(f);
@ -440,6 +470,11 @@ UPB_API_INLINE struct upb_Map* upb_Message_GetMutableMap(
  return (struct upb_Map*)upb_Message_GetMap(msg, f);
 }

+UPB_API_INLINE struct upb_Message* upb_Message_GetMutableMessage(
+    struct upb_Message* msg, const upb_MiniTableField* f) {
+  return (struct upb_Message*)upb_Message_GetMessage(msg, f);
+}
+
 UPB_API_INLINE upb_Array* upb_Message_GetOrCreateMutableArray(
    struct upb_Message* msg, const upb_MiniTableField* f, upb_Arena* arena) {
  UPB_ASSERT(arena);
@ -515,7 +550,6 @@ upb_Message_GetString(const struct upb_Message* msg,
             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
             kUpb_FieldRep_StringView);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));

  upb_MessageValue def;
  def.str_val = default_val;
@ -526,8 +560,8 @@ UPB_API_INLINE uint32_t upb_Message_GetUInt32(const struct upb_Message* msg,
                                              const upb_MiniTableField* f,
                                              uint32_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);

  upb_MessageValue def;
  def.uint32_val = default_val;
@ -538,23 +572,89 @@ UPB_API_INLINE uint64_t upb_Message_GetUInt64(const struct upb_Message* msg,
                                              const upb_MiniTableField* f,
                                              uint64_t default_val) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);

  upb_MessageValue def;
  def.uint64_val = default_val;
  return upb_Message_GetField(msg, f, def).uint64_val;
 }

-UPB_API_INLINE bool upb_Message_SetBool(struct upb_Message* msg,
-                                        const upb_MiniTableField* f, bool value,
-                                        upb_Arena* a) {
+// BaseField Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE void upb_Message_SetBaseFieldBool(struct upb_Message* msg,
+                                                 const upb_MiniTableField* f,
+                                                 bool value) {
  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Bool);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.bool_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_1Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldDouble(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   double value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldFloat(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  float value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldInt32(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  int32_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
+             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldInt64(struct upb_Message* msg,
+                                                  const upb_MiniTableField* f,
+                                                  int64_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldString(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   upb_StringView value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_String ||
+             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
+             kUpb_FieldRep_StringView);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldUInt32(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   uint32_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
+  upb_Message_SetBaseField(msg, f, &value);
+}
+
+UPB_API_INLINE void upb_Message_SetBaseFieldUInt64(struct upb_Message* msg,
+                                                   const upb_MiniTableField* f,
+                                                   uint64_t value) {
+  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
+  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
+  upb_Message_SetBaseField(msg, f, &value);
 }

 UPB_API_INLINE void upb_Message_SetClosedEnum(
@ -562,55 +662,141 @@ UPB_API_INLINE void upb_Message_SetClosedEnum(
    const upb_MiniTableField* f, int32_t value) {
  UPB_ASSERT(upb_MiniTableField_IsClosedEnum(f));
  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
  UPB_ASSERT(upb_MiniTableEnum_CheckValue(
      upb_MiniTable_GetSubEnumTable(msg_mini_table, f), value));
  upb_Message_SetBaseField(msg, f, &value);
 }

+// Extension Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE bool upb_Message_SetExtensionBool(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, bool value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Bool);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_1Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionDouble(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, double value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Double);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionFloat(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, float value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Float);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionInt32(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, int32_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Int32 ||
+             upb_MiniTableExtension_CType(e) == kUpb_CType_Enum);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionInt64(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, int64_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_Int64);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionString(
+    struct upb_Message* msg, const upb_MiniTableExtension* e,
+    upb_StringView value, upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_String ||
+             upb_MiniTableExtension_CType(e) == kUpb_CType_Bytes);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_StringView);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionUInt32(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, uint32_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_UInt32);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_4Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+UPB_API_INLINE bool upb_Message_SetExtensionUInt64(
+    struct upb_Message* msg, const upb_MiniTableExtension* e, uint64_t value,
+    upb_Arena* a) {
+  UPB_ASSUME(upb_MiniTableExtension_CType(e) == kUpb_CType_UInt64);
+  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(e) ==
+             kUpb_FieldRep_8Byte);
+  return upb_Message_SetExtension(msg, e, &value, a);
+}
+
+// Universal Setters ///////////////////////////////////////////////////////////
+
+UPB_API_INLINE bool upb_Message_SetBool(struct upb_Message* msg,
+                                        const upb_MiniTableField* f, bool value,
+                                        upb_Arena* a) {
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionBool(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldBool(msg, f, value), true);
+}
+
 UPB_API_INLINE bool upb_Message_SetDouble(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          double value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Double);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.double_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionDouble(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldDouble(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetFloat(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         float value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Float);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.float_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionFloat(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldFloat(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetInt32(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int32_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int32 ||
-             upb_MiniTableField_CType(f) == kUpb_CType_Enum);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.int32_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionInt32(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldInt32(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetInt64(struct upb_Message* msg,
                                         const upb_MiniTableField* f,
                                         int64_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_Int64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.int64_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionInt64(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldInt64(msg, f, value), true);
+}
+
+// Sets the value of a message-typed field. The mini_tables of `msg` and
+// `value` must have been linked for this to work correctly.
+UPB_API_INLINE void upb_Message_SetMessage(struct upb_Message* msg,
+                                           const upb_MiniTableField* f,
+                                           struct upb_Message* value) {
+  UPB_PRIVATE(_upb_Message_SetTaggedMessagePtr)
+  (msg, f, UPB_PRIVATE(_upb_TaggedMessagePtr_Pack)(value, false));
 }

 // Sets the value of a `string` or `bytes` field. The bytes of the value are not
@ -620,36 +806,28 @@ UPB_API_INLINE bool upb_Message_SetInt64(struct upb_Message* msg,
 UPB_API_INLINE bool upb_Message_SetString(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          upb_StringView value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_String ||
-             upb_MiniTableField_CType(f) == kUpb_CType_Bytes);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) ==
-             kUpb_FieldRep_StringView);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.str_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionString(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldString(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetUInt32(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint32_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt32);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_4Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.uint32_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionUInt32(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldUInt32(msg, f, value), true);
 }

 UPB_API_INLINE bool upb_Message_SetUInt64(struct upb_Message* msg,
                                          const upb_MiniTableField* f,
                                          uint64_t value, upb_Arena* a) {
-  UPB_ASSUME(upb_MiniTableField_CType(f) == kUpb_CType_UInt64);
-  UPB_ASSUME(UPB_PRIVATE(_upb_MiniTableField_GetRep)(f) == kUpb_FieldRep_8Byte);
-  UPB_ASSUME(upb_MiniTableField_IsScalar(f));
-  upb_MessageValue val;
-  val.uint64_val = value;
-  return UPB_PRIVATE(_upb_Message_SetField)(msg, f, val, a);
+  return upb_MiniTableField_IsExtension(f)
+             ? upb_Message_SetExtensionUInt64(
+                   msg, (const upb_MiniTableExtension*)f, value, a)
+             : (upb_Message_SetBaseFieldUInt64(msg, f, value), true);
 }

 UPB_API_INLINE void upb_Message_Clear(struct upb_Message* msg,
--- a/upb/message/promote.c
+++ b/upb/message/promote.c
@ -188,7 +188,7 @@ upb_DecodeStatus upb_Message_PromoteMessage(upb_Message* parent,
      upb_Message_PromoteOne(&tagged, sub_table, decode_options, arena);
  if (ret == kUpb_DecodeStatus_Ok) {
    *promoted = upb_TaggedMessagePtr_GetNonEmptyMessage(tagged);
-    upb_Message_SetMessage(parent, mini_table, field, *promoted);
+    upb_Message_SetMessage(parent, field, *promoted);
  }
  return ret;
 }
@ -280,7 +280,7 @@ upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
    if (is_oneof) {
      UPB_PRIVATE(_upb_Message_SetOneofCase)(msg, field);
    }
-    upb_Message_SetMessage(msg, mini_table, field, message);
+    upb_Message_SetMessage(msg, field, message);
    ret.message = message;
  }
  return ret;
--- a/upb/mini_table/internal/extension.h
+++ b/upb/mini_table/internal/extension.h
@ -8,6 +8,7 @@
 #ifndef UPB_MINI_TABLE_INTERNAL_EXTENSION_H_
 #define UPB_MINI_TABLE_INTERNAL_EXTENSION_H_

+#include <stddef.h>
 #include <stdint.h>

 #include "upb/base/descriptor_constants.h"
@ -41,6 +42,9 @@ upb_MiniTableExtension_Number(const struct upb_MiniTableExtension* e) {

 UPB_API_INLINE const struct upb_MiniTable* upb_MiniTableExtension_GetSubMessage(
    const struct upb_MiniTableExtension* e) {
+  if (upb_MiniTableExtension_CType(e) != kUpb_CType_Message) {
+    return NULL;
+  }
  return upb_MiniTableSub_Message(e->UPB_PRIVATE(sub));
 }

@ -49,6 +53,11 @@ UPB_API_INLINE void upb_MiniTableExtension_SetSubMessage(
  e->UPB_PRIVATE(sub).UPB_PRIVATE(submsg) = m;
 }

+UPB_INLINE upb_FieldRep UPB_PRIVATE(_upb_MiniTableExtension_GetRep)(
+    const struct upb_MiniTableExtension* e) {
+  return UPB_PRIVATE(_upb_MiniTableField_GetRep)(&e->UPB_PRIVATE(field));
+}
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
--- a/upb/reflection/message.c
+++ b/upb/reflection/message.c
@ -41,8 +41,8 @@ bool upb_Message_HasFieldByDef(const upb_Message* msg, const upb_FieldDef* f) {
  }
 }

-const upb_FieldDef* upb_Message_WhichOneof(const upb_Message* msg,
-                                           const upb_OneofDef* o) {
+const upb_FieldDef* upb_Message_WhichOneofByDef(const upb_Message* msg,
+                                                const upb_OneofDef* o) {
  const upb_FieldDef* f = upb_OneofDef_Field(o, 0);
  if (upb_OneofDef_IsSynthetic(o)) {
    UPB_ASSERT(upb_OneofDef_FieldCount(o) == 1);
@ -56,6 +56,14 @@ const upb_FieldDef* upb_Message_WhichOneof(const upb_Message* msg,
  }
 }

+const upb_MiniTableField* upb_Message_WhichOneof(const upb_Message* msg,
+                                                 const upb_OneofDef* o) {
+  const upb_FieldDef* f = upb_OneofDef_Field(o, 0);
+  // Question for Haberman: should we do anything if synthetic?
+  // if (upb_OneofDef_IsSynthetic(o)) {...}
+  return upb_FieldDef_MiniTable(f);
+}
+
 upb_MessageValue upb_Message_GetFieldByDef(const upb_Message* msg,
                                           const upb_FieldDef* f) {
  upb_MessageValue default_val = upb_FieldDef_Default(f);
--- a/upb/reflection/message.h
+++ b/upb/reflection/message.h
@ -30,8 +30,11 @@ UPB_API upb_MutableMessageValue upb_Message_Mutable(upb_Message* msg,
                                                    upb_Arena* a);

 // Returns the field that is set in the oneof, or NULL if none are set.
-UPB_API const upb_FieldDef* upb_Message_WhichOneof(const upb_Message* msg,
-                                                   const upb_OneofDef* o);
+UPB_API const upb_FieldDef* upb_Message_WhichOneofByDef(const upb_Message* msg,
+                                                        const upb_OneofDef* o);
+
+UPB_API const upb_MiniTableField* upb_Message_WhichOneOf(const upb_Message* msg,
+                                                         const upb_OneofDef* o);

 // Clear all data and unknown fields.
 void upb_Message_ClearByDef(upb_Message* msg, const upb_MessageDef* m);
Author	SHA1	Message	Date
Hong Shin	22a9ebe0c4	rename upb_Message_WhichOneof to upb_Message_WhichOneofByDef and introduce upb_Message_WhichOneof that returns a minitable field PiperOrigin-RevId: 631583174	2024-05-09 17:07:08 -07:00
Protobuf Team Bot	fefec68753	Internal changes/optimizations PiperOrigin-RevId: 632294209	2024-05-09 15:54:16 -07:00
Protobuf Team Bot	af1ecc0353	Add a check to ensure that the byte limit is not negative. PiperOrigin-RevId: 632284538	2024-05-09 15:18:31 -07:00
Protobuf Team Bot	eb31de3097	Auto-generate files after cl/632277936	2024-05-09 22:09:21 +00:00
Éamonn McManus	b5fc2735e9	In `upb_MiniTableExtension_GetSubMessage`, return NULL for non-messages. This parallels the logic in `upb_MiniTable_SubMessage`. PiperOrigin-RevId: 632277936	2024-05-09 14:57:53 -07:00
Joshua Haberman	5a91d6fe5e	[php] Added a unit test that bad UTF-8 is rejected in the parser. PiperOrigin-RevId: 632274113	2024-05-09 14:42:05 -07:00
Protobuf Team Bot	b51dc1b438	Auto-generate files after cl/632267379	2024-05-09 21:34:06 +00:00
Eric Salo	6245733655	upb: remove the unused (upb_MiniTable*) arg from upb_Message_SetMessage() PiperOrigin-RevId: 632267379	2024-05-09 14:22:25 -07:00
Sandy Zhang	f68350225f	Move system_python.bzl to the correct open source folder PiperOrigin-RevId: 632265705	2024-05-09 14:18:46 -07:00
Jie Luo	495ba7bcdb	Nextgen Proto Pythonic API: “Add-on” proto for serialize/parse - add google.protobuf.proto module - wrap generated SerializeToString and ParseFromString to the new module: def serialize(message: Message, deterministic: bool=None) -> bytes: """Return the serialized proto.""" def parse(message_class: typing.Type[Message], payload: bytes) -> Message: """Given a serialized proto, deserialize it into a Message.""" PiperOrigin-RevId: 632223409	2024-05-09 11:53:56 -07:00
Hong Shin	82e83ddc95	wire_format.cc: Refactor Message and Group handling into a helper func PiperOrigin-RevId: 632191495	2024-05-09 10:21:36 -07:00
Éamonn McManus	510c1434ed	Add `null` to the list of reserved words. The previous change claimed to do this in addition to `true` and `false`, but it was not actually in the code. To reiterate the text from the earlier change, now actually reflected entirely in the code: > The identifiers `true`, `false`, and `null` are effectively reserved words in Java, although for some reason they are listed separately from the "keywords" in the Java Language Specification. > > This doesn't matter for regular fields, because a proto field called `true` will be accessed with `getTrue` and `setTrue`. But for extensions, the generated Java code will have a public static field whose name is the same as the name of the extension field, with `_` appended if the name is a reserved word. Previously there was no `_` for `true` etc, so the generated code would not compile. This change should not affect any existing client code in Java. If someone had tried to use an extension called `true` (etc), they would have found that the generated proto code did not compile. Now it is possible to reference such an extension as `true_`. PiperOrigin-RevId: 632174190	2024-05-09 09:30:45 -07:00
Protobuf Team Bot	dbc2baf5bd	Generate extension and k[FieldName]FieldNumber as constexpr int(s). PiperOrigin-RevId: 632173946	2024-05-09 09:26:57 -07:00
Protobuf Team Bot	13caa08692	Enable textproto conformance tests for "-0" and "-0F". -0 should be treated as distinct from 0 when deciding it is default valued for implicit presence fields. PiperOrigin-RevId: 632162352	2024-05-09 08:46:57 -07:00
Protobuf Team Bot	1b06cefe33	Move casting functions to MessageLite and use ClassData as the uniqueness instead of Reflection. This allows using these functions instead of `dynamic_cast` for all generated types including LITE. PiperOrigin-RevId: 632135009	2024-05-09 07:00:26 -07:00
Sandy Zhang	7febb4c48f	Move upb/bazel/system_python.bzl (new alias file) to correct open source directory. PiperOrigin-RevId: 631958564	2024-05-08 16:22:35 -07:00
Protobuf Team Bot	b694cfa441	Clarify that the input to proto2::DynamicMessageFactory::GetPrototype should be non-null PiperOrigin-RevId: 631938646	2024-05-08 15:16:02 -07:00
Protobuf Team Bot	ec126a5069	Replace the single user of `PROTOBUF_ALIGNAS` with `alignas` and remove the now dead macro. This reduces the compile time cost of port_def.inc PiperOrigin-RevId: 631886181	2024-05-08 12:27:42 -07:00
Protobuf Team Bot	64580b29c1	Expose JavaPackageDirectory and FileClassName in java/names.h PiperOrigin-RevId: 631870244	2024-05-08 11:35:56 -07:00
Protobuf Team Bot	d5b7d7a87f	Remove dead feature macro. The opt-out code was removed some time ago. PiperOrigin-RevId: 631826723	2024-05-08 09:30:53 -07:00
Brent Shaffer	01744cccae	chore(php): conformance testing for edition (#16712 ) COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/16712 from bshaffer:php-editions `a1c41add7d` PiperOrigin-RevId: 631824623	2024-05-08 09:23:08 -07:00
Sandy Zhang	b77343aa2c	Add temporary alias for system_python.bzl at previous location . This was added to protobuf_deps.bzl in cl/629786458 and no longer needs to be specified directly in WORKSPACE. However, an alias is needed to prevent users from breaking when upgrading from 26.x -> 27.x due to the obsolete load pointing to the wrong path. This alias will be removed in a future release, tentatively 4.30.x. PiperOrigin-RevId: 631821637	2024-05-08 09:18:42 -07:00
Protobuf Team Bot	d8329b68e4	Add .to_owned(&self)->Msg functions to MsgMut and MsgView PiperOrigin-RevId: 631686314	2024-05-08 00:54:28 -07:00
Protobuf Team Bot	6afb130dca	Auto-generate files after cl/631620526	2024-05-08 02:19:22 +00:00
Eric Salo	d923896299	upb: implement most of the non-universal setters PiperOrigin-RevId: 631620526	2024-05-07 19:07:33 -07:00
Protobuf Team Bot	4d3a98c27e	Auto-generate files after cl/631612923	2024-05-08 01:37:14 +00:00
Eric Salo	65821a67d6	upb: finish cleaning up message/accessors.h and message/internal/accessors.h PiperOrigin-RevId: 631612923	2024-05-07 18:25:25 -07:00
Éamonn McManus	98d5bdd111	Add "reserved literals" to the list of reserved names for Java. The identifiers `true`, `false`, and `null` are effectively reserved words in Java, although for some reason they are listed separately from the "keywords" in the Java Language Specification. This doesn't matter for regular fields, because a proto field called `true` will be accessed with `getTrue` and `setTrue`. But for extensions, the generated Java code will have a public static field whose name is the same as the name of the extension field, with `_` appended if the name is a reserved word. Previously there was no `_` for `true` etc, so the generated code would not compile. PiperOrigin-RevId: 631599695	2024-05-07 17:23:09 -07:00