Sync from Piper @mkruskal/footmitten

PROTOBUF_SYNC_PIPER

BUILD.bazel

@@ -324,6 +324,12 @@ alias(
 # Test protos
 ################################################################################
 
+alias(
+    name = "lite_test_proto_srcs",
+    actual = "//src/google/protobuf:lite_test_proto_srcs",  # proto_library
+    visibility = ["//:__subpackages__"],
+)
+
 alias(
     name = "lite_test_protos",
     actual = "//src/google/protobuf:lite_test_protos",  # proto_library

CHANGES.txt

@@ -39,6 +39,9 @@
     constructed FieldMaskTrees.
   * Optimized Java proto serialization gencode for protos having many extension ranges with few fields in between.
   * More thoroughly annotate public generated code in Java lite protocol buffers.
+  * Fixed Bug in proto3 java lite repeated enum fields. Failed to call copyOnWrite before modifying previously built message. Causes modification to already "built" messages that should be immutable.
+  * Refactoring java full runtime to reuse sub-message builders and prepare to migrate parsing logic from parse constructor to builder.
+  * Fix Java reflection serialization of empty packed fields.
 
   Python
   * Changes ordering of printed fields in .pyi files from lexicographic to the same ordering found in the proto descriptor.

Protobuf-C++.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = 'Protobuf-C++'
-  s.version  = '3.21.5'
+  s.version  = '3.21.6'
   s.summary  = 'Protocol Buffers v3 runtime library for C++.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = 'BSD-3-Clause'

cmake/conformance.cmake

@@ -1,6 +1,8 @@
 
 add_custom_command(
-  OUTPUT ${protobuf_SOURCE_DIR}/conformance/conformance.pb.cc
+  OUTPUT
+    ${protobuf_SOURCE_DIR}/conformance/conformance.pb.h
+    ${protobuf_SOURCE_DIR}/conformance/conformance.pb.cc
   DEPENDS ${protobuf_PROTOC_EXE} ${protobuf_SOURCE_DIR}/conformance/conformance.proto
   COMMAND ${protobuf_PROTOC_EXE} ${protobuf_SOURCE_DIR}/conformance/conformance.proto
       --proto_path=${protobuf_SOURCE_DIR}/conformance
@@ -8,8 +10,11 @@ add_custom_command(
 )
 
 add_custom_command(
-  OUTPUT ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.cc
-         ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.cc
+  OUTPUT
+    ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.h
+    ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.cc
+    ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.h
+    ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.cc
   DEPENDS ${protobuf_PROTOC_EXE} ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.proto
           ${protobuf_PROTOC_EXE} ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.proto
   COMMAND ${protobuf_PROTOC_EXE} ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.proto
@@ -21,6 +26,7 @@ add_custom_command(
 add_executable(conformance_test_runner
   ${protobuf_SOURCE_DIR}/conformance/binary_json_conformance_suite.cc
   ${protobuf_SOURCE_DIR}/conformance/binary_json_conformance_suite.h
+  ${protobuf_SOURCE_DIR}/conformance/conformance.pb.h
   ${protobuf_SOURCE_DIR}/conformance/conformance.pb.cc
   ${protobuf_SOURCE_DIR}/conformance/conformance_test.cc
   ${protobuf_SOURCE_DIR}/conformance/conformance_test_runner.cc
@@ -29,14 +35,19 @@ add_executable(conformance_test_runner
   ${protobuf_SOURCE_DIR}/conformance/text_format_conformance_suite.h
   ${protobuf_SOURCE_DIR}/conformance/third_party/jsoncpp/json.h
   ${protobuf_SOURCE_DIR}/conformance/third_party/jsoncpp/jsoncpp.cpp
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.cc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.cc
 )
 
 add_executable(conformance_cpp
+  ${protobuf_SOURCE_DIR}/conformance/conformance.pb.h
   ${protobuf_SOURCE_DIR}/conformance/conformance.pb.cc
   ${protobuf_SOURCE_DIR}/conformance/conformance_cpp.cc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto2.pb.cc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_messages_proto3.pb.cc
 )
 

cmake/install.cmake

@@ -47,7 +47,7 @@ include(${protobuf_SOURCE_DIR}/src/file_lists.cmake)
 set(protobuf_HEADERS
   ${libprotobuf_hdrs}
   ${libprotoc_hdrs}
-  ${wkt_protos_proto_srcs}
+  ${wkt_protos_files}
   ${descriptor_proto_proto_srcs}
   ${plugin_proto_proto_srcs}
 )

cmake/tests.cmake

@@ -43,19 +43,20 @@ endif()
 include(${protobuf_SOURCE_DIR}/src/file_lists.cmake)
 
 set(lite_test_protos
-  ${protobuf_lite_test_protos_proto_srcs}
+  ${protobuf_lite_test_protos_files}
 )
 
 set(tests_protos
-  ${protobuf_test_protos_proto_srcs}
+  ${protobuf_test_protos_files}
   ${compiler_test_protos_files}
   ${util_test_protos_files}
 )
 
 macro(compile_proto_file filename)
-  string(REPLACE .proto .pb.cc pb_file ${filename})
+  string(REPLACE .proto .pb.h pb_hdr ${filename})
+  string(REPLACE .proto .pb.cc pb_src ${filename})
   add_custom_command(
-    OUTPUT ${pb_file}
+    OUTPUT ${pb_hdr} ${pb_src}
     DEPENDS ${protobuf_PROTOC_EXE} ${filename}
     COMMAND ${protobuf_PROTOC_EXE} ${filename}
         --proto_path=${protobuf_SOURCE_DIR}/src
@@ -67,13 +68,13 @@ endmacro(compile_proto_file)
 set(lite_test_proto_files)
 foreach(proto_file ${lite_test_protos})
   compile_proto_file(${proto_file})
-  set(lite_test_proto_files ${lite_test_proto_files} ${pb_file})
+  set(lite_test_proto_files ${lite_test_proto_files} ${pb_src} ${pb_hdr})
 endforeach(proto_file)
 
 set(tests_proto_files)
 foreach(proto_file ${tests_protos})
   compile_proto_file(${proto_file})
-  set(tests_proto_files ${tests_proto_files} ${pb_file})
+  set(tests_proto_files ${tests_proto_files} ${pb_src} ${pb_hdr})
 endforeach(proto_file)
 
 add_library(protobuf-lite-test-common STATIC
@@ -85,8 +86,8 @@ target_link_libraries(protobuf-lite-test-common
 set(common_test_files
   ${test_util_hdrs}
   ${test_util_srcs}
-  ${mock_code_generator_srcs}
-  ${testing_srcs}
+  ${common_test_hdrs}
+  ${common_test_srcs}
 )
 
 add_library(protobuf-test-common STATIC
@@ -138,8 +139,8 @@ target_link_libraries(tests protobuf-lite-test-common protobuf-test-common ${pro
 
 set(test_plugin_files
   ${test_plugin_files}
-  ${mock_code_generator_srcs}
-  ${testing_srcs}
+  ${common_test_hdrs}
+  ${common_test_srcs}
 )
 
 add_executable(test_plugin ${test_plugin_files})
@@ -172,13 +173,23 @@ add_custom_target(save-installed-headers)
 add_custom_target(remove-installed-headers)
 add_custom_target(restore-installed-headers)
 
-# Explicitly skip the bootstrapping headers as it's directly used in tests
-set(_installed_hdrs ${libprotobuf_hdrs} ${libprotoc_hdrs})
-list(REMOVE_ITEM _installed_hdrs
+file(GLOB_RECURSE _local_hdrs
+  "${PROJECT_SOURCE_DIR}/src/*.h"
+  "${PROJECT_SOURCE_DIR}/src/*.inc")
+
+# Exclude the bootstrapping that are directly used by tests.
+set(_exclude_hdrs
   "${protobuf_SOURCE_DIR}/src/google/protobuf/descriptor.pb.h"
   "${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/plugin.pb.h")
 
-foreach(_hdr ${_installed_hdrs})
+# Exclude test library headers.
+list(APPEND _exclude_hdrs ${test_util_hdrs} ${lite_test_util_hdrs} ${common_test_hdrs}
+  ${compiler_test_utils_hdrs})
+foreach(_hdr ${_exclude_hdrs})
+  list(REMOVE_ITEM _local_hdrs ${_hdr})
+endforeach()
+
+foreach(_hdr ${_local_hdrs})
   string(REPLACE "${protobuf_SOURCE_DIR}/src" "" _file ${_hdr})
   set(_tmp_file "${CMAKE_BINARY_DIR}/tmp-install-test/${_file}")
   add_custom_command(TARGET remove-installed-headers PRE_BUILD
@@ -193,6 +204,6 @@ endforeach()
 
 add_dependencies(remove-installed-headers save-installed-headers)
 if(protobuf_REMOVE_INSTALLED_HEADERS)
-  add_dependencies(protobuf-lite-test-common remove-installed-headers)
-  add_dependencies(protobuf-test-common remove-installed-headers)
+  # Make sure we remove all the headers *before* any codegen occurs.
+  add_dependencies(${protobuf_PROTOC_EXE} remove-installed-headers)
 endif()

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

@@ -424,27 +424,22 @@ public abstract class AbstractMessage
         throws IOException {
       boolean discardUnknown = input.shouldDiscardUnknownFields();
       final UnknownFieldSet.Builder unknownFields =
-          discardUnknown ? null : UnknownFieldSet.newBuilder(getUnknownFields());
-      while (true) {
-        final int tag = input.readTag();
-        if (tag == 0) {
-          break;
-        }
-
-        MessageReflection.BuilderAdapter builderAdapter =
-            new MessageReflection.BuilderAdapter(this);
-        if (!MessageReflection.mergeFieldFrom(
-            input, unknownFields, extensionRegistry, getDescriptorForType(), builderAdapter, tag)) {
-          // end group tag
-          break;
-        }
-      }
+          discardUnknown ? null : getUnknownFieldSetBuilder();
+      MessageReflection.mergeMessageFrom(this, unknownFields, input, extensionRegistry);
       if (unknownFields != null) {
-        setUnknownFields(unknownFields.build());
+        setUnknownFieldSetBuilder(unknownFields);
       }
       return (BuilderType) this;
     }
 
+    protected UnknownFieldSet.Builder getUnknownFieldSetBuilder() {
+      return UnknownFieldSet.newBuilder(getUnknownFields());
+    }
+
+    protected void setUnknownFieldSetBuilder(final UnknownFieldSet.Builder builder) {
+      setUnknownFields(builder.build());
+    }
+
     @Override
     public BuilderType mergeUnknownFields(final UnknownFieldSet unknownFields) {
       setUnknownFields(

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

@@ -427,8 +427,8 @@ final class DescriptorMessageInfoFactory implements MessageInfoFactory {
     boolean enforceUtf8 = true;
     for (int i = 0; i < fieldDescriptors.size(); ++i) {
       FieldDescriptor fd = fieldDescriptors.get(i);
-      if (fd.getContainingOneof() != null) {
-        // Build a oneof member field.
+      if (fd.getContainingOneof() != null && !fd.getContainingOneof().isSynthetic()) {
+        // Build a oneof member field. But only if it is a real oneof, not a proto3 optional
         builder.withField(buildOneofMember(messageType, fd, oneofState, enforceUtf8, null));
         continue;
       }

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

@@ -413,7 +413,10 @@ public final class DynamicMessage extends AbstractMessage {
 
       DynamicMessage result =
           new DynamicMessage(
-              type, fields.build(), Arrays.copyOf(oneofCases, oneofCases.length), unknownFields);
+              type,
+              fields.buildPartial(),
+              Arrays.copyOf(oneofCases, oneofCases.length),
+              unknownFields);
       return result;
     }
 

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

@@ -926,8 +926,27 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
       this.isMutable = true;
     }
 
-    /** Creates the FieldSet */
+    /**
+     * Creates the FieldSet
+     *
+     * @throws UninitializedMessageException if a message field is missing required fields.
+     */
     public FieldSet<T> build() {
+      return buildImpl(false);
+    }
+
+    /** Creates the FieldSet but does not validate that all required fields are present. */
+    public FieldSet<T> buildPartial() {
+      return buildImpl(true);
+    }
+
+    /**
+     * Creates the FieldSet.
+     *
+     * @param partial controls whether to do a build() or buildPartial() when converting submessage
+     *     builders to messages.
+     */
+    private FieldSet<T> buildImpl(boolean partial) {
       if (fields.isEmpty()) {
         return FieldSet.emptySet();
       }
@@ -936,7 +955,7 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
       if (hasNestedBuilders) {
         // Make a copy of the fields map with all Builders replaced by Message.
         fieldsForBuild = cloneAllFieldsMap(fields, /* copyList */ false);
-        replaceBuilders(fieldsForBuild);
+        replaceBuilders(fieldsForBuild, partial);
       }
       FieldSet<T> fieldSet = new FieldSet<>(fieldsForBuild);
       fieldSet.hasLazyField = hasLazyField;
@@ -944,22 +963,22 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
     }
 
     private static <T extends FieldDescriptorLite<T>> void replaceBuilders(
-        SmallSortedMap<T, Object> fieldMap) {
+        SmallSortedMap<T, Object> fieldMap, boolean partial) {
       for (int i = 0; i < fieldMap.getNumArrayEntries(); i++) {
-        replaceBuilders(fieldMap.getArrayEntryAt(i));
+        replaceBuilders(fieldMap.getArrayEntryAt(i), partial);
       }
       for (Map.Entry<T, Object> entry : fieldMap.getOverflowEntries()) {
-        replaceBuilders(entry);
+        replaceBuilders(entry, partial);
       }
     }
 
     private static <T extends FieldDescriptorLite<T>> void replaceBuilders(
-        Map.Entry<T, Object> entry) {
-      entry.setValue(replaceBuilders(entry.getKey(), entry.getValue()));
+        Map.Entry<T, Object> entry, boolean partial) {
+      entry.setValue(replaceBuilders(entry.getKey(), entry.getValue(), partial));
     }
 
     private static <T extends FieldDescriptorLite<T>> Object replaceBuilders(
-        T descriptor, Object value) {
+        T descriptor, Object value, boolean partial) {
       if (value == null) {
         return value;
       }
@@ -974,7 +993,7 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
           List<Object> list = (List<Object>) value;
           for (int i = 0; i < list.size(); i++) {
             Object oldElement = list.get(i);
-            Object newElement = replaceBuilder(oldElement);
+            Object newElement = replaceBuilder(oldElement, partial);
             if (newElement != oldElement) {
               // If the list contains a Message.Builder, then make a copy of that list and then
               // modify the Message.Builder into a Message and return the new list. This way, the
@@ -988,14 +1007,21 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
           }
           return list;
         } else {
-          return replaceBuilder(value);
+          return replaceBuilder(value, partial);
         }
       }
       return value;
     }
 
-    private static Object replaceBuilder(Object value) {
-      return (value instanceof MessageLite.Builder) ? ((MessageLite.Builder) value).build() : value;
+    private static Object replaceBuilder(Object value, boolean partial) {
+      if (!(value instanceof MessageLite.Builder)) {
+        return value;
+      }
+      MessageLite.Builder builder = (MessageLite.Builder) value;
+      if (partial) {
+        return builder.buildPartial();
+      }
+      return builder.build();
     }
 
     /** Returns a new Builder using the fields from {@code fieldSet}. */
@@ -1014,7 +1040,7 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
         if (fields.isImmutable()) {
           result.makeImmutable();
         } else {
-          replaceBuilders(result);
+          replaceBuilders(result, true);
         }
         return result;
       }
@@ -1037,7 +1063,7 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
      */
     public Object getField(final T descriptor) {
       Object value = getFieldAllowBuilders(descriptor);
-      return replaceBuilders(descriptor, value);
+      return replaceBuilders(descriptor, value, true);
     }
 
     /** Same as {@link #getField(F)}, but allow a {@link MessageLite.Builder} to be returned. */
@@ -1123,7 +1149,7 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {
         ensureIsMutable();
       }
       Object value = getRepeatedFieldAllowBuilders(descriptor, index);
-      return replaceBuilder(value);
+      return replaceBuilder(value, true);
     }
 
     /**

java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java

@@ -129,7 +129,10 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
     return internalGetFieldAccessorTable().descriptor;
   }
 
-  // TODO(gberg): remove this. Have to leave it for now to support old gencode.
+  // TODO(b/248143958): This method should be removed. It enables parsing directly into an
+  // "immutable" message. Have to leave it for now to support old gencode.
+  // @deprecated use newBuilder().mergeFrom() instead
+  @Deprecated
   protected void mergeFromAndMakeImmutableInternal(
       CodedInputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
@@ -287,12 +290,14 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
 
   @Override
   public UnknownFieldSet getUnknownFields() {
-    throw new UnsupportedOperationException("This is supposed to be overridden by subclasses.");
+    return unknownFields;
   }
 
   /**
    * Called by subclasses to parse an unknown field.
    *
+   * <p>TODO(b/248153893) remove this method
+   *
    * @return {@code true} unless the tag is an end-group tag.
    */
   protected boolean parseUnknownField(
@@ -310,6 +315,8 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
   /**
    * Delegates to parseUnknownField. This method is obsolete, but we must retain it for
    * compatibility with older generated code.
+   *
+   * <p>TODO(b/248153893) remove this method
    */
   protected boolean parseUnknownFieldProto3(
       CodedInputStream input,
@@ -525,7 +532,18 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
     // to dispatch dirty invalidations. See GeneratedMessageV3.BuilderListener.
     private boolean isClean;
 
-    private UnknownFieldSet unknownFields = UnknownFieldSet.getDefaultInstance();
+    /**
+     * This field holds either an {@link UnknownFieldSet} or {@link UnknownFieldSet.Builder}.
+     *
+     * <p>We use an object because it should only be one or the other of those things at a time and
+     * Object is the only common base. This also saves space.
+     *
+     * <p>Conversions are lazy: if {@link #setUnknownFields} is called, this will contain {@link
+     * UnknownFieldSet}. If unknown fields are merged into this builder, the current {@link
+     * UnknownFieldSet} will be converted to a {@link UnknownFieldSet.Builder} and left that way
+     * until either {@link #setUnknownFields} or {@link #buildPartial} or {@link #build} is called.
+     */
+    private Object unknownFieldsOrBuilder = UnknownFieldSet.getDefaultInstance();
 
     protected Builder() {
       this(null);
@@ -578,7 +596,7 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
      */
     @Override
     public BuilderType clear() {
-      unknownFields = UnknownFieldSet.getDefaultInstance();
+      unknownFieldsOrBuilder = UnknownFieldSet.getDefaultInstance();
       onChanged();
       return (BuilderType) this;
     }
@@ -725,7 +743,7 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
     }
 
     private BuilderType setUnknownFieldsInternal(final UnknownFieldSet unknownFields) {
-      this.unknownFields = unknownFields;
+      unknownFieldsOrBuilder = unknownFields;
       onChanged();
       return (BuilderType) this;
     }
@@ -744,8 +762,19 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
 
     @Override
     public BuilderType mergeUnknownFields(final UnknownFieldSet unknownFields) {
-      return setUnknownFields(
-          UnknownFieldSet.newBuilder(this.unknownFields).mergeFrom(unknownFields).build());
+      if (UnknownFieldSet.getDefaultInstance().equals(unknownFields)) {
+        return (BuilderType) this;
+      }
+
+      if (UnknownFieldSet.getDefaultInstance().equals(unknownFieldsOrBuilder)) {
+        unknownFieldsOrBuilder = unknownFields;
+        onChanged();
+        return (BuilderType) this;
+      }
+
+      getUnknownFieldSetBuilder().mergeFrom(unknownFields);
+      onChanged();
+      return (BuilderType) this;
     }
 
     @Override
@@ -779,7 +808,50 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
 
     @Override
     public final UnknownFieldSet getUnknownFields() {
-      return unknownFields;
+      if (unknownFieldsOrBuilder instanceof UnknownFieldSet) {
+        return (UnknownFieldSet) unknownFieldsOrBuilder;
+      } else {
+        return ((UnknownFieldSet.Builder) unknownFieldsOrBuilder).buildPartial();
+      }
+    }
+
+    /**
+     * Called by generated subclasses to parse an unknown field.
+     *
+     * @return {@code true} unless the tag is an end-group tag.
+     */
+    protected boolean parseUnknownField(
+        CodedInputStream input, ExtensionRegistryLite extensionRegistry, int tag)
+        throws IOException {
+      if (input.shouldDiscardUnknownFields()) {
+        return input.skipField(tag);
+      }
+      return getUnknownFieldSetBuilder().mergeFieldFrom(tag, input);
+    }
+
+    /** Called by generated subclasses to add to the unknown field set. */
+    protected final void mergeUnknownLengthDelimitedField(int number, ByteString bytes) {
+      getUnknownFieldSetBuilder().mergeLengthDelimitedField(number, bytes);
+    }
+
+    /** Called by generated subclasses to add to the unknown field set. */
+    protected final void mergeUnknownVarintField(int number, int value) {
+      getUnknownFieldSetBuilder().mergeVarintField(number, value);
+    }
+
+    @Override
+    protected UnknownFieldSet.Builder getUnknownFieldSetBuilder() {
+      if (unknownFieldsOrBuilder instanceof UnknownFieldSet) {
+        unknownFieldsOrBuilder = ((UnknownFieldSet) unknownFieldsOrBuilder).toBuilder();
+      }
+      onChanged();
+      return (UnknownFieldSet.Builder) unknownFieldsOrBuilder;
+    }
+
+    @Override
+    protected void setUnknownFieldSetBuilder(UnknownFieldSet.Builder builder) {
+      unknownFieldsOrBuilder = builder;
+      onChanged();
     }
 
     /**
@@ -1541,7 +1613,7 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
     private FieldSet<FieldDescriptor> buildExtensions() {
       return extensions == null
           ? (FieldSet<FieldDescriptor>) FieldSet.emptySet()
-          : extensions.build();
+          : extensions.buildPartial();
     }
 
     @Override
@@ -1744,6 +1816,20 @@ public abstract class GeneratedMessageV3 extends AbstractMessage implements Seri
       }
     }
 
+    @Override
+    protected boolean parseUnknownField(
+        CodedInputStream input, ExtensionRegistryLite extensionRegistry, int tag)
+        throws IOException {
+      ensureExtensionsIsMutable();
+      return MessageReflection.mergeFieldFrom(
+          input,
+          input.shouldDiscardUnknownFields() ? null : getUnknownFieldSetBuilder(),
+          extensionRegistry,
+          getDescriptorForType(),
+          new MessageReflection.ExtensionBuilderAdapter(extensions),
+          tag);
+    }
+
     private void verifyContainingType(final FieldDescriptor field) {
       if (field.getContainingType() != getDescriptorForType()) {
         throw new IllegalArgumentException("FieldDescriptor does not match message type.");

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

@@ -30,6 +30,7 @@
 
 package com.google.protobuf;
 
+import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -323,6 +324,34 @@ class MessageReflection {
         Message defaultInstance)
         throws IOException;
 
+    /**
+     * Read the given group field from the wire, merging with the existing field if it is already
+     * present.
+     *
+     * <p>For extensions, defaultInstance must be specified. For regular fields, defaultInstance can
+     * be null.
+     */
+    void mergeGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException;
+
+    /**
+     * Read the given message field from the wire, merging with the existing field if it is already
+     * present.
+     *
+     * <p>For extensions, defaultInstance must be specified. For regular fields, defaultInstance can
+     * be null.
+     */
+    void mergeMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException;
+
     /** Returns the UTF8 validation level for the field. */
     WireFormat.Utf8Validation getUtf8Validation(Descriptors.FieldDescriptor descriptor);
 
@@ -499,6 +528,60 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
+    @Override
+    public void mergeGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      if (!field.isRepeated()) {
+        if (hasField(field)) {
+          input.readGroup(field.getNumber(), builder.getFieldBuilder(field), extensionRegistry);
+          return;
+        }
+        Message.Builder subBuilder = newMessageFieldInstance(field, defaultInstance);
+        input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+        Object unused = setField(field, subBuilder.buildPartial());
+      } else {
+        Message.Builder subBuilder = newMessageFieldInstance(field, defaultInstance);
+        input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+        Object unused = addRepeatedField(field, subBuilder.buildPartial());
+      }
+    }
+
+    @Override
+    public void mergeMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      if (!field.isRepeated()) {
+        if (hasField(field)) {
+          input.readMessage(builder.getFieldBuilder(field), extensionRegistry);
+          return;
+        }
+        Message.Builder subBuilder = newMessageFieldInstance(field, defaultInstance);
+        input.readMessage(subBuilder, extensionRegistry);
+        Object unused = setField(field, subBuilder.buildPartial());
+      } else {
+        Message.Builder subBuilder = newMessageFieldInstance(field, defaultInstance);
+        input.readMessage(subBuilder, extensionRegistry);
+        Object unused = addRepeatedField(field, subBuilder.buildPartial());
+      }
+    }
+
+    private Message.Builder newMessageFieldInstance(
+        FieldDescriptor field, Message defaultInstance) {
+      // When default instance is not null. The field is an extension field.
+      if (defaultInstance != null) {
+        return defaultInstance.newBuilderForType();
+      } else {
+        return builder.newBuilderForField(field);
+      }
+    }
+
     @Override
     public MergeTarget newMergeTargetForField(
         Descriptors.FieldDescriptor field, Message defaultInstance) {
@@ -665,6 +748,54 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
+    @Override
+    public void mergeGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      if (!field.isRepeated()) {
+        if (hasField(field)) {
+          MessageLite.Builder current = ((MessageLite) getField(field)).toBuilder();
+          input.readGroup(field.getNumber(), current, extensionRegistry);
+          Object unused = setField(field, current.buildPartial());
+          return;
+        }
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+        Object unused = setField(field, subBuilder.buildPartial());
+      } else {
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+        Object unused = addRepeatedField(field, subBuilder.buildPartial());
+      }
+    }
+
+    @Override
+    public void mergeMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      if (!field.isRepeated()) {
+        if (hasField(field)) {
+          MessageLite.Builder current = ((MessageLite) getField(field)).toBuilder();
+          input.readMessage(current, extensionRegistry);
+          Object unused = setField(field, current.buildPartial());
+          return;
+        }
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readMessage(subBuilder, extensionRegistry);
+        Object unused = setField(field, subBuilder.buildPartial());
+      } else {
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readMessage(subBuilder, extensionRegistry);
+        Object unused = addRepeatedField(field, subBuilder.buildPartial());
+      }
+    }
+
     @Override
     public Object parseMessageFromBytes(
         ByteString bytes,
@@ -700,7 +831,234 @@ class MessageReflection {
       if (descriptor.needsUtf8Check()) {
         return WireFormat.Utf8Validation.STRICT;
       }
-      // TODO(liujisi): support lazy strings for ExtesnsionSet.
+      // TODO(b/248145492): support lazy strings for ExtesnsionSet.
+      return WireFormat.Utf8Validation.LOOSE;
+    }
+
+    @Override
+    public Object finish() {
+      throw new UnsupportedOperationException("finish() called on FieldSet object");
+    }
+  }
+
+  static class ExtensionBuilderAdapter implements MergeTarget {
+
+    private final FieldSet.Builder<Descriptors.FieldDescriptor> extensions;
+
+    ExtensionBuilderAdapter(FieldSet.Builder<Descriptors.FieldDescriptor> extensions) {
+      this.extensions = extensions;
+    }
+
+    @Override
+    public Descriptors.Descriptor getDescriptorForType() {
+      throw new UnsupportedOperationException("getDescriptorForType() called on FieldSet object");
+    }
+
+    @Override
+    public Object getField(Descriptors.FieldDescriptor field) {
+      return extensions.getField(field);
+    }
+
+    @Override
+    public boolean hasField(Descriptors.FieldDescriptor field) {
+      return extensions.hasField(field);
+    }
+
+    @Override
+    @CanIgnoreReturnValue
+    public MergeTarget setField(Descriptors.FieldDescriptor field, Object value) {
+      extensions.setField(field, value);
+      return this;
+    }
+
+    @Override
+    @CanIgnoreReturnValue
+    public MergeTarget clearField(Descriptors.FieldDescriptor field) {
+      extensions.clearField(field);
+      return this;
+    }
+
+    @Override
+    @CanIgnoreReturnValue
+    public MergeTarget setRepeatedField(
+        Descriptors.FieldDescriptor field, int index, Object value) {
+      extensions.setRepeatedField(field, index, value);
+      return this;
+    }
+
+    @Override
+    @CanIgnoreReturnValue
+    public MergeTarget addRepeatedField(Descriptors.FieldDescriptor field, Object value) {
+      extensions.addRepeatedField(field, value);
+      return this;
+    }
+
+    @Override
+    public boolean hasOneof(Descriptors.OneofDescriptor oneof) {
+      return false;
+    }
+
+    @Override
+    @CanIgnoreReturnValue
+    public MergeTarget clearOneof(Descriptors.OneofDescriptor oneof) {
+      // Nothing to clear.
+      return this;
+    }
+
+    @Override
+    public Descriptors.FieldDescriptor getOneofFieldDescriptor(Descriptors.OneofDescriptor oneof) {
+      return null;
+    }
+
+    @Override
+    public ContainerType getContainerType() {
+      return ContainerType.EXTENSION_SET;
+    }
+
+    @Override
+    public ExtensionRegistry.ExtensionInfo findExtensionByName(
+        ExtensionRegistry registry, String name) {
+      return registry.findImmutableExtensionByName(name);
+    }
+
+    @Override
+    public ExtensionRegistry.ExtensionInfo findExtensionByNumber(
+        ExtensionRegistry registry, Descriptors.Descriptor containingType, int fieldNumber) {
+      return registry.findImmutableExtensionByNumber(containingType, fieldNumber);
+    }
+
+    @Override
+    public Object parseGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      Message.Builder subBuilder = defaultInstance.newBuilderForType();
+      if (!field.isRepeated()) {
+        Message originalMessage = (Message) getField(field);
+        if (originalMessage != null) {
+          subBuilder.mergeFrom(originalMessage);
+        }
+      }
+      input.readGroup(field.getNumber(), subBuilder, registry);
+      return subBuilder.buildPartial();
+    }
+
+    @Override
+    public Object parseMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      Message.Builder subBuilder = defaultInstance.newBuilderForType();
+      if (!field.isRepeated()) {
+        Message originalMessage = (Message) getField(field);
+        if (originalMessage != null) {
+          subBuilder.mergeFrom(originalMessage);
+        }
+      }
+      input.readMessage(subBuilder, registry);
+      return subBuilder.buildPartial();
+    }
+
+    @Override
+    public void mergeGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      if (!field.isRepeated()) {
+        if (hasField(field)) {
+          Object fieldOrBuilder = extensions.getFieldAllowBuilders(field);
+          MessageLite.Builder subBuilder;
+          if (fieldOrBuilder instanceof MessageLite.Builder) {
+            subBuilder = (MessageLite.Builder) fieldOrBuilder;
+          } else {
+            subBuilder = ((MessageLite) fieldOrBuilder).toBuilder();
+            extensions.setField(field, subBuilder);
+          }
+          input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+          return;
+        }
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+        Object unused = setField(field, subBuilder);
+      } else {
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
+        Object unused = addRepeatedField(field, subBuilder.buildPartial());
+      }
+    }
+
+    @Override
+    public void mergeMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite extensionRegistry,
+        FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      if (!field.isRepeated()) {
+        if (hasField(field)) {
+          Object fieldOrBuilder = extensions.getFieldAllowBuilders(field);
+          MessageLite.Builder subBuilder;
+          if (fieldOrBuilder instanceof MessageLite.Builder) {
+            subBuilder = (MessageLite.Builder) fieldOrBuilder;
+          } else {
+            subBuilder = ((MessageLite) fieldOrBuilder).toBuilder();
+            extensions.setField(field, subBuilder);
+          }
+          input.readMessage(subBuilder, extensionRegistry);
+          return;
+        }
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readMessage(subBuilder, extensionRegistry);
+        Object unused = setField(field, subBuilder);
+      } else {
+        Message.Builder subBuilder = defaultInstance.newBuilderForType();
+        input.readMessage(subBuilder, extensionRegistry);
+        Object unused = addRepeatedField(field, subBuilder.buildPartial());
+      }
+    }
+
+    @Override
+    public Object parseMessageFromBytes(
+        ByteString bytes,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
+      Message.Builder subBuilder = defaultInstance.newBuilderForType();
+      if (!field.isRepeated()) {
+        Message originalMessage = (Message) getField(field);
+        if (originalMessage != null) {
+          subBuilder.mergeFrom(originalMessage);
+        }
+      }
+      subBuilder.mergeFrom(bytes, registry);
+      return subBuilder.buildPartial();
+    }
+
+    @Override
+    public MergeTarget newMergeTargetForField(
+        Descriptors.FieldDescriptor descriptor, Message defaultInstance) {
+      throw new UnsupportedOperationException("newMergeTargetForField() called on FieldSet object");
+    }
+
+    @Override
+    public MergeTarget newEmptyTargetForField(
+        Descriptors.FieldDescriptor descriptor, Message defaultInstance) {
+      throw new UnsupportedOperationException("newEmptyTargetForField() called on FieldSet object");
+    }
+
+    @Override
+    public WireFormat.Utf8Validation getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
+      if (descriptor.needsUtf8Check()) {
+        return WireFormat.Utf8Validation.STRICT;
+      }
+      // TODO(b/248145492): support lazy strings for ExtesnsionSet.
       return WireFormat.Utf8Validation.LOOSE;
     }
 
@@ -829,13 +1187,13 @@ class MessageReflection {
       switch (field.getType()) {
         case GROUP:
           {
-            value = target.parseGroup(input, extensionRegistry, field, defaultInstance);
-            break;
+            target.mergeGroup(input, extensionRegistry, field, defaultInstance);
+            return true;
           }
         case MESSAGE:
           {
-            value = target.parseMessage(input, extensionRegistry, field, defaultInstance);
-            break;
+            target.mergeMessage(input, extensionRegistry, field, defaultInstance);
+            return true;
           }
         case ENUM:
           final int rawValue = input.readEnum();
@@ -870,6 +1228,29 @@ class MessageReflection {
     return true;
   }
 
+  /** Read a message from the given input stream into the provided target and UnknownFieldSet. */
+  static void mergeMessageFrom(
+      Message.Builder target,
+      UnknownFieldSet.Builder unknownFields,
+      CodedInputStream input,
+      ExtensionRegistryLite extensionRegistry)
+      throws IOException {
+    BuilderAdapter builderAdapter = new BuilderAdapter(target);
+    Descriptor descriptorForType = target.getDescriptorForType();
+    while (true) {
+      final int tag = input.readTag();
+      if (tag == 0) {
+        break;
+      }
+
+      if (!mergeFieldFrom(
+          input, unknownFields, extensionRegistry, descriptorForType, builderAdapter, tag)) {
+        // end group tag
+        break;
+      }
+    }
+  }
+
   /** Called by {@code #mergeFieldFrom()} to parse a MessageSet extension into MergeTarget. */
   private static void mergeMessageSetExtensionFromCodedStream(
       CodedInputStream input,

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

@@ -604,7 +604,7 @@ public final class TextFormat {
 
         case MESSAGE:
         case GROUP:
-          print((Message) value, generator);
+          print((MessageOrBuilder) value, generator);
           break;
       }
     }

java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java

@@ -35,6 +35,7 @@ import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.FieldMask;
+import com.google.protobuf.GeneratedMessage;
 import com.google.protobuf.Message;
 import java.util.ArrayList;
 import java.util.List;
@@ -292,7 +293,11 @@ final class FieldMaskTree {
           // so we don't create unnecessary empty messages.
           continue;
         }
-        Message.Builder childBuilder = ((Message) destination.getField(field)).toBuilder();
+        // This is a mess because of java proto API 1 still hanging around.
+        Message.Builder childBuilder =
+            destination instanceof GeneratedMessage.Builder
+                ? destination.getFieldBuilder(field)
+                : ((Message) destination.getField(field)).toBuilder();
         merge(entry.getValue(), (Message) source.getField(field), childBuilder, options);
         destination.setField(field, childBuilder.buildPartial());
         continue;

pkg/BUILD.bazel

@@ -314,20 +314,18 @@ gen_file_lists(
         "//src/google/protobuf:descriptor_proto": "descriptor_proto",
         "//src/google/protobuf/compiler:plugin_proto": "plugin_proto",
         # Test libraries:
+        ":common_test": "common_test",
         ":lite_test_util": "lite_test_util",
         ":test_util": "test_util",
         # Tests and test-only protos:
         "//src/google/protobuf:full_test_srcs": "protobuf_test",
-        "//src/google/protobuf:test_protos": "protobuf_test_protos",
+        "//src/google/protobuf:test_proto_srcs": "protobuf_test_protos",
         "//src/google/protobuf:lite_test_srcs": "protobuf_lite_test",
-        "//src/google/protobuf:lite_test_protos": "protobuf_lite_test_protos",
+        "//src/google/protobuf:lite_test_proto_srcs": "protobuf_lite_test_protos",
         "//src/google/protobuf/compiler:test_srcs": "compiler_test",
-        ":compiler_annotation_test_util": "annotation_test_util",
-        ":compiler_mock_code_generator": "mock_code_generator",
         "//src/google/protobuf/compiler:test_proto_srcs": "compiler_test_protos",
         "//src/google/protobuf/compiler:test_plugin_srcs": "test_plugin",
         "//src/google/protobuf/io:test_srcs": "io_test",
-        ":testinglib": "testing",
         "//src/google/protobuf/util:test_srcs": "util_test",
         "//src/google/protobuf/util:test_proto_srcs": "util_test_protos",
         "//src/google/protobuf/stubs:test_srcs": "stubs_test",
@@ -365,10 +363,11 @@ cc_dist_library(
     }),
     tags = ["manual"],
     deps = [
-        "//src/google/protobuf:wkt_cc_proto",
-        "//src/google/protobuf:protobuf_nowkt",
         "//src/google/protobuf:arena",
+        "//src/google/protobuf:port_def",
         "//src/google/protobuf:protobuf_lite",
+        "//src/google/protobuf:protobuf_nowkt",
+        "//src/google/protobuf:wkt_cc_proto",
         "//src/google/protobuf/compiler:importer",
         "//src/google/protobuf/io",
         "//src/google/protobuf/io:gzip_stream",
@@ -384,6 +383,7 @@ cc_dist_library(
         "//src/google/protobuf/util:json_util",
         "//src/google/protobuf/util:time_util",
         "//src/google/protobuf/util:type_resolver_util",
+        "//src/google/protobuf/util/internal:constants",
         "//src/google/protobuf/util/internal:datapiece",
         "//src/google/protobuf/util/internal:default_value",
         "//src/google/protobuf/util/internal:field_mask_utility",
@@ -422,28 +422,25 @@ cc_dist_library(
     name = "test_util",
     testonly = 1,
     tags = ["manual"],
-    deps = ["//src/google/protobuf:test_util"],
-)
-
-cc_dist_library(
-    name = "compiler_annotation_test_util",
-    testonly = 1,
-    tags = ["manual"],
-    deps = ["//src/google/protobuf/compiler:annotation_test_util"],
-)
-
-cc_dist_library(
-    name = "compiler_mock_code_generator",
-    testonly = 1,
-    tags = ["manual"],
-    deps = ["//src/google/protobuf/compiler:mock_code_generator"],
+    deps = [
+        "//src/google/protobuf:test_util",
+        "//src/google/protobuf:test_util2",
+        "//src/google/protobuf/compiler:annotation_test_util",
+        "//src/google/protobuf/compiler/cpp:unittest_lib",
+        "//src/google/protobuf/util/internal:expecting_objectwriter",
+        "//src/google/protobuf/util/internal:mock_error_listener",
+        "//src/google/protobuf/util/internal:type_info_test_helper",
+    ],
 )
 
 cc_dist_library(
-    name = "testinglib",
+    name = "common_test",
     testonly = 1,
     tags = ["manual"],
-    deps = ["//src/google/protobuf/testing"],
+    deps = [
+        "//src/google/protobuf/compiler:mock_code_generator",
+        "//src/google/protobuf/testing",
+    ],
 )
 
 ################################################################################

python/google/protobuf/__init__.py

@@ -30,4 +30,4 @@
 
 # Copyright 2007 Google Inc. All Rights Reserved.
 
-__version__ = '4.21.5'
+__version__ = '4.21.6'

src/file_lists.cmake

@@ -156,6 +156,8 @@ set(libprotobuf_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/metadata_lite.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/parse_context.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/port.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/port_def.inc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/port_undef.inc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/reflection.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/reflection_internal.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/reflection_ops.h
@@ -177,6 +179,7 @@ set(libprotobuf_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/delimited_message_util.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/field_comparator.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/field_mask_util.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/constants.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/datapiece.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/default_value_objectwriter.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/error_listener.h
@@ -520,6 +523,20 @@ set(plugin_proto_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/plugin_proto-descriptor-set.proto.bin
 )
 
+# //pkg:common_test
+set(common_test_srcs
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/mock_code_generator.cc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/file.cc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/googletest.cc
+)
+
+# //pkg:common_test
+set(common_test_hdrs
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/mock_code_generator.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/file.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/googletest.h
+)
+
 # //pkg:lite_test_util
 set(lite_test_util_srcs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/arena_test_util.cc
@@ -538,12 +555,17 @@ set(lite_test_util_hdrs
 
 # //pkg:test_util
 set(test_util_srcs
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/annotation_test_util.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/reflection_tester.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_util.cc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/type_info_test_helper.cc
 )
 
 # //pkg:test_util
 set(test_util_hdrs
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/annotation_test_util.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/cpp/unittest.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/cpp/unittest.inc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/map_test.inc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/map_test_util.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/map_test_util.inc
@@ -551,7 +573,11 @@ set(test_util_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/reflection_tester.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_util.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_util.inc
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/test_util2.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/test_util_lite.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/expecting_objectwriter.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/mock_error_listener.h
+  ${protobuf_SOURCE_DIR}/src/google/protobuf/util/internal/type_info_test_helper.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/wire_format_unittest.inc
 )
 
@@ -586,8 +612,8 @@ set(protobuf_test_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/wire_format_unittest.cc
 )
 
-# //src/google/protobuf:test_protos
-set(protobuf_test_protos_proto_srcs
+# //src/google/protobuf:test_proto_srcs
+set(protobuf_test_protos_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/any_test.proto
   ${protobuf_SOURCE_DIR}/src/google/protobuf/map_proto2_unittest.proto
   ${protobuf_SOURCE_DIR}/src/google/protobuf/map_unittest.proto
@@ -619,112 +645,20 @@ set(protobuf_test_protos_proto_srcs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_well_known_types.proto
 )
 
-# //src/google/protobuf:test_protos
-set(protobuf_test_protos_srcs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/any_test.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/map_proto2_unittest.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/map_unittest.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_arena.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_custom_options.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_drop_unknown_fields.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_embed_optimize_for.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_empty.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_enormous_descriptor.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_public.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lazy_dependencies.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lazy_dependencies_custom_option.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lazy_dependencies_enum.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lite_imports_nonlite.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_mset.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_mset_wire_format.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_no_field_presence.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_no_generic_services.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_optimize_for.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_preserve_unknown_enum.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_preserve_unknown_enum2.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_arena.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_arena_lite.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_lite.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_optional.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_well_known_types.proto.pb.cc
-)
-
-# //src/google/protobuf:test_protos
-set(protobuf_test_protos_hdrs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/any_test.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/map_proto2_unittest.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/map_unittest.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_arena.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_custom_options.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_drop_unknown_fields.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_embed_optimize_for.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_empty.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_enormous_descriptor.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_public.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lazy_dependencies.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lazy_dependencies_custom_option.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lazy_dependencies_enum.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lite_imports_nonlite.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_mset.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_mset_wire_format.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_no_field_presence.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_no_generic_services.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_optimize_for.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_preserve_unknown_enum.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_preserve_unknown_enum2.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_arena.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_arena_lite.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_lite.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_proto3_optional.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_well_known_types.proto.pb.h
-)
-
-# //src/google/protobuf:test_protos
-set(protobuf_test_protos_files
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/test_protos-descriptor-set.proto.bin
-)
-
 # //src/google/protobuf:lite_test_srcs
 set(protobuf_lite_test_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/lite_arena_unittest.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/lite_unittest.cc
 )
 
-# //src/google/protobuf:lite_test_protos
-set(protobuf_lite_test_protos_proto_srcs
+# //src/google/protobuf:lite_test_proto_srcs
+set(protobuf_lite_test_protos_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/map_lite_unittest.proto
   ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_lite.proto
   ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_public_lite.proto
   ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lite.proto
 )
 
-# //src/google/protobuf:lite_test_protos
-set(protobuf_lite_test_protos_srcs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/map_lite_unittest.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_lite.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_public_lite.proto.pb.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lite.proto.pb.cc
-)
-
-# //src/google/protobuf:lite_test_protos
-set(protobuf_lite_test_protos_hdrs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/map_lite_unittest.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_lite.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_import_public_lite.proto.pb.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/unittest_lite.proto.pb.h
-)
-
-# //src/google/protobuf:lite_test_protos
-set(protobuf_lite_test_protos_files
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/lite_test_protos-descriptor-set.proto.bin
-)
-
 # //src/google/protobuf/compiler:test_srcs
 set(compiler_test_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/command_line_interface_unittest.cc
@@ -746,26 +680,6 @@ set(compiler_test_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/ruby/ruby_generator_unittest.cc
 )
 
-# //pkg:compiler_annotation_test_util
-set(annotation_test_util_srcs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/annotation_test_util.cc
-)
-
-# //pkg:compiler_annotation_test_util
-set(annotation_test_util_hdrs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/annotation_test_util.h
-)
-
-# //pkg:compiler_mock_code_generator
-set(mock_code_generator_srcs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/mock_code_generator.cc
-)
-
-# //pkg:compiler_mock_code_generator
-set(mock_code_generator_hdrs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/mock_code_generator.h
-)
-
 # //src/google/protobuf/compiler:test_proto_srcs
 set(compiler_test_protos_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/compiler/cpp/test_bad_identifiers.proto
@@ -788,18 +702,6 @@ set(io_test_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/io/zero_copy_stream_unittest.cc
 )
 
-# //pkg:testinglib
-set(testing_srcs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/file.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/googletest.cc
-)
-
-# //pkg:testinglib
-set(testing_hdrs
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/file.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/testing/googletest.h
-)
-
 # //src/google/protobuf/util:test_srcs
 set(util_test_files
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/delimited_message_util_test.cc

src/google/protobuf/BUILD.bazel

@@ -392,14 +392,20 @@ filegroup(
     ],
 )
 
-proto_library(
-    name = "lite_test_protos",
+filegroup(
+    name = "lite_test_proto_srcs",
     srcs = [
         "map_lite_unittest.proto",
         "unittest_import_lite.proto",
         "unittest_import_public_lite.proto",
         "unittest_lite.proto",
     ],
+    visibility = ["//:__subpackages__"],
+)
+
+proto_library(
+    name = "lite_test_protos",
+    srcs = [":lite_test_proto_srcs"],
     strip_import_prefix = "/src",
     visibility = ["//:__subpackages__"],
     deps = [

src/google/protobuf/arena.cc

@@ -122,7 +122,7 @@ SerialArena::SerialArena(ArenaBlock* b, ThreadSafeArena& parent)
     : ptr_{b->Pointer(kBlockHeaderSize + ThreadSafeArena::kSerialArenaSize)},
       limit_{b->Limit()},
       head_{b},
-      space_allocated_{b->size()},
+      space_allocated_{b->size},
       parent_{parent} {
   GOOGLE_DCHECK(!b->IsSentry());
 }
@@ -135,7 +135,7 @@ SerialArena::SerialArena(ThreadSafeArena& parent)
 // provided or newly allocated to store AllocationPolicy.
 SerialArena::SerialArena(FirstSerialArena, ArenaBlock* b,
                          ThreadSafeArena& parent)
-    : head_{b}, space_allocated_{b->size()}, parent_{parent} {
+    : head_{b}, space_allocated_{b->size}, parent_{parent} {
   if (b->IsSentry()) return;
 
   set_ptr(b->Pointer(kBlockHeaderSize));
@@ -145,9 +145,9 @@ SerialArena::SerialArena(FirstSerialArena, ArenaBlock* b,
 void SerialArena::Init(ArenaBlock* b, size_t offset) {
   set_ptr(b->Pointer(offset));
   limit_ = b->Limit();
-  set_head(b);
+  head_.relaxed_set(b);
   space_used_.relaxed_set(0);
-  space_allocated_.relaxed_set(b->size());
+  space_allocated_.relaxed_set(b->size);
   cached_block_length_ = 0;
   cached_blocks_ = nullptr;
 }
@@ -164,11 +164,11 @@ SerialArena* SerialArena::New(Memory mem, ThreadSafeArena& parent) {
 template <typename Deallocator>
 SerialArena::Memory SerialArena::Free(Deallocator deallocator) {
   ArenaBlock* b = head();
-  Memory mem = {b, b->size()};
+  Memory mem = {b, b->size};
   while (b->next) {
     b = b->next;  // We must first advance before deleting this block
     deallocator(mem);
-    mem = {b, b->size()};
+    mem = {b, b->size};
   }
   return mem;
 }
@@ -204,7 +204,7 @@ void SerialArena::AllocateNewBlock(size_t n) {
 
     // Record how much used in this block.
     used = static_cast<size_t>(ptr() - old_head->Pointer(kBlockHeaderSize));
-    wasted = old_head->size() - used;
+    wasted = old_head->size - used;
     space_used_.relaxed_set(space_used_.relaxed_get() + used);
   }
 
@@ -213,7 +213,7 @@ void SerialArena::AllocateNewBlock(size_t n) {
   // but with a CPU regression. The regression might have been an artifact of
   // the microbenchmark.
 
-  auto mem = AllocateMemory(parent_.AllocPolicy(), old_head->size(), n);
+  auto mem = AllocateMemory(parent_.AllocPolicy(), old_head->size, n);
   // We don't want to emit an expensive RMW instruction that requires
   // exclusive access to a cacheline. Hence we write it in terms of a
   // regular add.
@@ -222,9 +222,10 @@ void SerialArena::AllocateNewBlock(size_t n) {
                                             /*used=*/used,
                                             /*allocated=*/mem.size, wasted);
   auto* new_head = new (mem.ptr) ArenaBlock{old_head, mem.size};
-  set_head(new_head);
   set_ptr(new_head->Pointer(kBlockHeaderSize));
   limit_ = new_head->Limit();
+  // Previous writes must take effect before writing new head.
+  head_.atomic_set(new_head);
 
 #ifdef ADDRESS_SANITIZER
   ASAN_POISON_MEMORY_REGION(ptr(), limit_ - ptr());
@@ -239,10 +240,10 @@ uint64_t SerialArena::SpaceUsed() const {
   // usage of the *current* block.
   // TODO(mkruskal) Consider eliminating this race in exchange for a possible
   // performance hit on ARM (see cl/455186837).
-  const ArenaBlock* h = head();
+  const ArenaBlock* h = head_.atomic_get();
   if (h->IsSentry()) return 0;
 
-  const uint64_t current_block_size = h->size();
+  const uint64_t current_block_size = h->size;
   uint64_t current_space_used = std::min(
       static_cast<uint64_t>(
           ptr() - const_cast<ArenaBlock*>(h)->Pointer(kBlockHeaderSize)),
@@ -400,7 +401,7 @@ class ThreadSafeArena::SerialArenaChunk {
     }
 
     id(idx).relaxed_set(me);
-    arena(idx).relaxed_set(serial);
+    arena(idx).atomic_set(serial);
     return true;
   }
 
@@ -774,7 +775,7 @@ template <typename Functor>
 void ThreadSafeArena::PerConstSerialArenaInChunk(Functor fn) const {
   WalkConstSerialArenaChunk([&fn](const SerialArenaChunk* chunk) {
     for (const auto& each : chunk->arenas()) {
-      const SerialArena* serial = each.relaxed_get();
+      const SerialArena* serial = each.atomic_get();
       // It is possible that newly added SerialArena is not updated although
       // size was. This is acceptable for SpaceAllocated and SpaceUsed.
       if (serial == nullptr) continue;

src/google/protobuf/arena_impl.h

@@ -94,11 +94,9 @@ struct Atomic {
   PROTOBUF_CONSTEXPR explicit Atomic(T v) : val(v) {}
 
   T relaxed_get() const { return val.load(std::memory_order_relaxed); }
-  T relaxed_get() { return val.load(std::memory_order_relaxed); }
   void relaxed_set(T v) { val.store(v, std::memory_order_relaxed); }
 
   T atomic_get() const { return val.load(std::memory_order_acquire); }
-  T atomic_get() { return val.load(std::memory_order_acquire); }
   void atomic_set(T v) { val.store(v, std::memory_order_release); }
 
   T relaxed_fetch_add(T v) {
@@ -115,27 +113,24 @@ struct ArenaBlock {
   // For the sentry block with zero-size where ptr_, limit_, cleanup_nodes all
   // point to "this".
   PROTOBUF_CONSTEXPR ArenaBlock()
-      : next(nullptr), cleanup_nodes(this), relaxed_size(0) {}
+      : next(nullptr), cleanup_nodes(this), size(0) {}
 
   ArenaBlock(ArenaBlock* next, size_t size)
-      : next(next), cleanup_nodes(nullptr), relaxed_size(size) {
+      : next(next), cleanup_nodes(nullptr), size(size) {
     GOOGLE_DCHECK_GT(size, sizeof(ArenaBlock));
   }
 
   char* Pointer(size_t n) {
-    GOOGLE_DCHECK_LE(n, size());
+    GOOGLE_DCHECK_LE(n, size);
     return reinterpret_cast<char*>(this) + n;
   }
-  char* Limit() { return Pointer(size() & static_cast<size_t>(-8)); }
+  char* Limit() { return Pointer(size & static_cast<size_t>(-8)); }
 
-  size_t size() const { return relaxed_size.relaxed_get(); }
-  bool IsSentry() const { return size() == 0; }
+  bool IsSentry() const { return size == 0; }
 
   ArenaBlock* const next;
   void* cleanup_nodes;
-
- private:
-  const Atomic<size_t> relaxed_size;
+  const size_t size;
   // data follows
 };
 
@@ -618,7 +613,6 @@ class PROTOBUF_EXPORT SerialArena {
   // Helper getters/setters to handle relaxed operations on atomic variables.
   ArenaBlock* head() { return head_.relaxed_get(); }
   const ArenaBlock* head() const { return head_.relaxed_get(); }
-  void set_head(ArenaBlock* head) { return head_.relaxed_set(head); }
 
   char* ptr() { return ptr_.relaxed_get(); }
   const char* ptr() const { return ptr_.relaxed_get(); }

src/google/protobuf/compiler/cpp/BUILD.bazel

@@ -98,6 +98,7 @@ cc_library(
         "unittest.inc",
     ],
     strip_include_prefix = "/src",
+    visibility = ["//pkg:__pkg__"],
 )
 
 cc_test(

src/google/protobuf/compiler/cpp/message_size_unittest.cc

@@ -139,9 +139,9 @@ TEST(GeneratedMessageTest, OneStringSize) {
 
 TEST(GeneratedMessageTest, MoreStringSize) {
   struct MockGenerated : public MockMessageBase {  // 16 bytes
-    int has_bits[1];                               // 4 bytes
     int cached_size;                               // 4 bytes
     MockRepeatedPtrField data;                     // 24 bytes
+    // + 4 bytes padding
   };
   GOOGLE_CHECK_MESSAGE_SIZE(MockGenerated, 48);
   EXPECT_EQ(sizeof(protobuf_unittest::MoreString), sizeof(MockGenerated));

src/google/protobuf/compiler/java/enum_field.cc

@@ -116,13 +116,6 @@ void SetEnumVariables(const FieldDescriptor* descriptor, int messageBitIndex,
   (*variables)["set_mutable_bit_builder"] = GenerateSetBit(builderBitIndex);
   (*variables)["clear_mutable_bit_builder"] = GenerateClearBit(builderBitIndex);
 
-  // For repeated fields, one bit is used for whether the array is immutable
-  // in the parsing constructor.
-  (*variables)["get_mutable_bit_parser"] =
-      GenerateGetBitMutableLocal(builderBitIndex);
-  (*variables)["set_mutable_bit_parser"] =
-      GenerateSetBitMutableLocal(builderBitIndex);
-
   (*variables)["get_has_field_bit_from_local"] =
       GenerateGetBitFromLocal(builderBitIndex);
   (*variables)["set_has_field_bit_to_local"] =
@@ -276,7 +269,7 @@ void ImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ var $kt_name$: $kt_type$\n"
+                 "$kt_deprecation$public var $kt_name$: $kt_type$\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -299,7 +292,7 @@ void ImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -308,7 +301,7 @@ void ImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
                                  /* builder */ false, /* kdoc */ true);
     printer->Print(
         variables_,
-        "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+        "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
         "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
         "}\n");
   }
@@ -360,31 +353,26 @@ void ImmutableEnumFieldGenerator::GenerateBuildingCode(
   printer->Print(variables_, "result.$name$_ = $name$_;\n");
 }
 
-void ImmutableEnumFieldGenerator::GenerateParsingCode(
+void ImmutableEnumFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   if (SupportUnknownEnumValue(descriptor_->file())) {
     printer->Print(variables_,
-                   "int rawValue = input.readEnum();\n"
-                   "$set_has_field_bit_message$\n"
-                   "$name$_ = rawValue;\n");
+                   "$name$_ = input.readEnum();\n"
+                   "$set_has_field_bit_builder$\n");
   } else {
     printer->Print(variables_,
-                   "int rawValue = input.readEnum();\n"
-                   "$type$ value = $type$.forNumber(rawValue);\n"
-                   "if (value == null) {\n"
-                   "  unknownFields.mergeVarintField($number$, rawValue);\n"
+                   "int tmpRaw = input.readEnum();\n"
+                   "$type$ tmpValue =\n"
+                   "    $type$.forNumber(tmpRaw);\n"
+                   "if (tmpValue == null) {\n"
+                   "  mergeUnknownVarintField($number$, tmpRaw);\n"
                    "} else {\n"
-                   "  $set_has_field_bit_message$\n"
-                   "  $name$_ = rawValue;\n"
+                   "  $name$_ = tmpRaw;\n"
+                   "  $set_has_field_bit_builder$\n"
                    "}\n");
   }
 }
 
-void ImmutableEnumFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  // noop for enums
-}
-
 void ImmutableEnumFieldGenerator::GenerateSerializationCode(
     io::Printer* printer) const {
   printer->Print(variables_,
@@ -543,6 +531,11 @@ void ImmutableEnumOneofFieldGenerator::GenerateBuilderMembers(
   printer->Annotate("{", "}", descriptor_);
 }
 
+void ImmutableEnumOneofFieldGenerator::GenerateBuilderClearCode(
+    io::Printer* printer) const {
+  // Enum fields in oneofs are correctly cleared by clearing the oneof
+}
+
 void ImmutableEnumOneofFieldGenerator::GenerateBuildingCode(
     io::Printer* printer) const {
   printer->Print(variables_,
@@ -563,7 +556,7 @@ void ImmutableEnumOneofFieldGenerator::GenerateMergingCode(
   }
 }
 
-void ImmutableEnumOneofFieldGenerator::GenerateParsingCode(
+void ImmutableEnumOneofFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   if (SupportUnknownEnumValue(descriptor_->file())) {
     printer->Print(variables_,
@@ -573,9 +566,10 @@ void ImmutableEnumOneofFieldGenerator::GenerateParsingCode(
   } else {
     printer->Print(variables_,
                    "int rawValue = input.readEnum();\n"
-                   "$type$ value = $type$.forNumber(rawValue);\n"
+                   "$type$ value =\n"
+                   "    $type$.forNumber(rawValue);\n"
                    "if (value == null) {\n"
-                   "  unknownFields.mergeVarintField($number$, rawValue);\n"
+                   "  mergeUnknownVarintField($number$, rawValue);\n"
                    "} else {\n"
                    "  $set_oneof_case_message$;\n"
                    "  $oneof_name$_ = rawValue;\n"
@@ -953,35 +947,29 @@ void RepeatedImmutableEnumFieldGenerator::GenerateBuildingCode(
       "result.$name$_ = $name$_;\n");
 }
 
-void RepeatedImmutableEnumFieldGenerator::GenerateParsingCode(
+void RepeatedImmutableEnumFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   // Read and store the enum
   if (SupportUnknownEnumValue(descriptor_->file())) {
     printer->Print(variables_,
-                   "int rawValue = input.readEnum();\n"
-                   "if (!$get_mutable_bit_parser$) {\n"
-                   "  $name$_ = new java.util.ArrayList<java.lang.Integer>();\n"
-                   "  $set_mutable_bit_parser$;\n"
-                   "}\n"
-                   "$name$_.add(rawValue);\n");
+                   "int tmpRaw = input.readEnum();\n"
+                   "ensure$capitalized_name$IsMutable();\n"
+                   "$name$_.add(tmpRaw);\n");
   } else {
-    printer->Print(
-        variables_,
-        "int rawValue = input.readEnum();\n"
-        "$type$ value = $type$.forNumber(rawValue);\n"
-        "if (value == null) {\n"
-        "  unknownFields.mergeVarintField($number$, rawValue);\n"
-        "} else {\n"
-        "  if (!$get_mutable_bit_parser$) {\n"
-        "    $name$_ = new java.util.ArrayList<java.lang.Integer>();\n"
-        "    $set_mutable_bit_parser$;\n"
-        "  }\n"
-        "  $name$_.add(rawValue);\n"
-        "}\n");
+    printer->Print(variables_,
+                   "int tmpRaw = input.readEnum();\n"
+                   "$type$ tmpValue =\n"
+                   "    $type$.forNumber(tmpRaw);\n"
+                   "if (tmpValue == null) {\n"
+                   "  mergeUnknownVarintField($number$, tmpRaw);\n"
+                   "} else {\n"
+                   "  ensure$capitalized_name$IsMutable();\n"
+                   "  $name$_.add(tmpRaw);\n"
+                   "}\n");
   }
 }
 
-void RepeatedImmutableEnumFieldGenerator::GenerateParsingCodeFromPacked(
+void RepeatedImmutableEnumFieldGenerator::GenerateBuilderParsingCodeFromPacked(
     io::Printer* printer) const {
   // Wrap GenerateParsingCode's contents with a while loop.
 
@@ -991,7 +979,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateParsingCodeFromPacked(
                  "while(input.getBytesUntilLimit() > 0) {\n");
   printer->Indent();
 
-  GenerateParsingCode(printer);
+  GenerateBuilderParsingCode(printer);
 
   printer->Outdent();
   printer->Print(variables_,
@@ -999,15 +987,6 @@ void RepeatedImmutableEnumFieldGenerator::GenerateParsingCodeFromPacked(
                  "input.popLimit(oldLimit);\n");
 }
 
-void RepeatedImmutableEnumFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  printer->Print(
-      variables_,
-      "if ($get_mutable_bit_parser$) {\n"
-      "  $name$_ = java.util.Collections.unmodifiableList($name$_);\n"
-      "}\n");
-}
-
 void RepeatedImmutableEnumFieldGenerator::GenerateSerializationCode(
     io::Printer* printer) const {
   if (descriptor_->is_packed()) {
@@ -1085,12 +1064,12 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -1103,7 +1082,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: $kt_type$) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -1115,7 +1094,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: $kt_type$) {\n"
                  "  add(value)\n"
@@ -1126,7 +1105,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "addAll(values: kotlin.collections.Iterable<$kt_type$>) {\n"
                  "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -1139,7 +1118,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<$kt_type$>) {\n"
       "  addAll(values)\n"
@@ -1151,7 +1130,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: $kt_type$) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -1162,7 +1141,7 @@ void RepeatedImmutableEnumFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/java/enum_field.h

@@ -75,10 +75,9 @@ class ImmutableEnumFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderMembers(io::Printer* printer) const override;
   void GenerateInitializationCode(io::Printer* printer) const override;
   void GenerateBuilderClearCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(
@@ -108,9 +107,10 @@ class ImmutableEnumOneofFieldGenerator : public ImmutableEnumFieldGenerator {
 
   void GenerateMembers(io::Printer* printer) const override;
   void GenerateBuilderMembers(io::Printer* printer) const override;
+  void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateEqualsCode(io::Printer* printer) const override;
@@ -138,9 +138,9 @@ class RepeatedImmutableEnumFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingCodeFromPacked(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCodeFromPacked(
+      io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(

src/google/protobuf/compiler/java/enum_field_lite.cc

@@ -318,7 +318,7 @@ void ImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: $kt_type$\n"
+                 "$kt_deprecation$public var $kt_name$: $kt_type$\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -341,17 +341,18 @@ void ImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
   if (HasHazzer(descriptor_)) {
     WriteFieldAccessorDocComment(printer, descriptor_, HAZZER,
                                  /* builder */ false, /* kdoc */ true);
-    printer->Print(variables_,
-                   "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
-                   "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
-                   "}\n");
+    printer->Print(
+        variables_,
+        "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+        "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
+        "}\n");
   }
 }
 
@@ -884,12 +885,12 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$ public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -902,7 +903,7 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: $kt_type$) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -914,7 +915,7 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: $kt_type$) {\n"
                  "  add(value)\n"
@@ -925,7 +926,7 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "addAll(values: kotlin.collections.Iterable<$kt_type$>) {\n"
                  "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -938,7 +939,7 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<$kt_type$>) {\n"
       "  addAll(values)\n"
@@ -950,7 +951,7 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: $kt_type$) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -961,7 +962,7 @@ void RepeatedImmutableEnumFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/java/field.cc

@@ -186,7 +186,7 @@ static inline void ReportUnexpectedPackedFieldsCall(io::Printer* printer) {
   //     but this method should be overridden.
   //   - This FieldGenerator doesn't support packing, and this method
   //     should never have been called.
-  GOOGLE_LOG(FATAL) << "GenerateParsingCodeFromPacked() "
+  GOOGLE_LOG(FATAL) << "GenerateBuilderParsingCodeFromPacked() "
              << "called on field generator that does not support packing.";
 }
 
@@ -194,7 +194,7 @@ static inline void ReportUnexpectedPackedFieldsCall(io::Printer* printer) {
 
 ImmutableFieldGenerator::~ImmutableFieldGenerator() {}
 
-void ImmutableFieldGenerator::GenerateParsingCodeFromPacked(
+void ImmutableFieldGenerator::GenerateBuilderParsingCodeFromPacked(
     io::Printer* printer) const {
   ReportUnexpectedPackedFieldsCall(printer);
 }

src/google/protobuf/compiler/java/field.h

@@ -80,9 +80,8 @@ class ImmutableFieldGenerator {
   virtual void GenerateBuilderClearCode(io::Printer* printer) const = 0;
   virtual void GenerateMergingCode(io::Printer* printer) const = 0;
   virtual void GenerateBuildingCode(io::Printer* printer) const = 0;
-  virtual void GenerateParsingCode(io::Printer* printer) const = 0;
-  virtual void GenerateParsingCodeFromPacked(io::Printer* printer) const;
-  virtual void GenerateParsingDoneCode(io::Printer* printer) const = 0;
+  virtual void GenerateBuilderParsingCode(io::Printer* printer) const = 0;
+  virtual void GenerateBuilderParsingCodeFromPacked(io::Printer* printer) const;
   virtual void GenerateSerializationCode(io::Printer* printer) const = 0;
   virtual void GenerateSerializedSizeCode(io::Printer* printer) const = 0;
   virtual void GenerateFieldBuilderInitializationCode(

src/google/protobuf/compiler/java/map_field.cc

@@ -180,13 +180,6 @@ void SetMessageVariables(const FieldDescriptor* descriptor, int messageBitIndex,
           : "";
   (*variables)["on_changed"] = "onChanged();";
 
-  // For repeated fields, one bit is used for whether the array is immutable
-  // in the parsing constructor.
-  (*variables)["get_mutable_bit_parser"] =
-      GenerateGetBitMutableLocal(builderBitIndex);
-  (*variables)["set_mutable_bit_parser"] =
-      GenerateSetBitMutableLocal(builderBitIndex);
-
   (*variables)["default_entry"] =
       (*variables)["capitalized_name"] + "DefaultEntryHolder.defaultEntry";
   (*variables)["map_field_parameter"] = (*variables)["default_entry"];
@@ -727,13 +720,13 @@ void ImmutableMapFieldGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(
       variables_,
-      "$kt_deprecation$ val $kt_name$: "
+      "$kt_deprecation$ public val $kt_name$: "
       "com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  @kotlin.jvm.JvmSynthetic\n"
@@ -746,7 +739,7 @@ void ImmutableMapFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(
       variables_,
       "@JvmName(\"put$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .put(key: $kt_key_type$, value: $kt_value_type$) {\n"
       "     $kt_dsl_builder$.${$put$capitalized_name$$}$(key, value)\n"
@@ -758,7 +751,7 @@ void ImmutableMapFieldGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"set$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslMap"
+      "public inline operator fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .set(key: $kt_key_type$, value: $kt_value_type$) {\n"
       "     put(key, value)\n"
@@ -769,7 +762,7 @@ void ImmutableMapFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"remove$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .remove(key: $kt_key_type$) {\n"
       "     $kt_dsl_builder$.${$remove$capitalized_name$$}$(key)\n"
@@ -780,7 +773,7 @@ void ImmutableMapFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"putAll$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .putAll(map: kotlin.collections.Map<$kt_key_type$, $kt_value_type$>) "
       "{\n"
@@ -792,7 +785,7 @@ void ImmutableMapFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"clear$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .clear() {\n"
       "     $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
@@ -829,27 +822,19 @@ void ImmutableMapFieldGenerator::GenerateBuildingCode(
                  "result.$name$_.makeImmutable();\n");
 }
 
-void ImmutableMapFieldGenerator::GenerateParsingCode(
+void ImmutableMapFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
-  printer->Print(variables_,
-                 "if (!$get_mutable_bit_parser$) {\n"
-                 "  $name$_ = com.google.protobuf.MapField.newMapField(\n"
-                 "      $map_field_parameter$);\n"
-                 "  $set_mutable_bit_parser$;\n"
-                 "}\n");
   if (!SupportUnknownEnumValue(descriptor_->file()) &&
       GetJavaType(ValueField(descriptor_)) == JAVATYPE_ENUM) {
     printer->Print(
         variables_,
         "com.google.protobuf.ByteString bytes = input.readBytes();\n"
         "com.google.protobuf.MapEntry<$type_parameters$>\n"
-        "$name$__ = $default_entry$.getParserForType().parseFrom(bytes);\n");
-    printer->Print(
-        variables_,
+        "$name$__ = $default_entry$.getParserForType().parseFrom(bytes);\n"
         "if ($value_enum_type$.forNumber($name$__.getValue()) == null) {\n"
-        "  unknownFields.mergeLengthDelimitedField($number$, bytes);\n"
+        "  mergeUnknownLengthDelimitedField($number$, bytes);\n"
         "} else {\n"
-        "  $name$_.getMutableMap().put(\n"
+        "  internalGetMutable$capitalized_name$().getMutableMap().put(\n"
         "      $name$__.getKey(), $name$__.getValue());\n"
         "}\n");
   } else {
@@ -858,16 +843,11 @@ void ImmutableMapFieldGenerator::GenerateParsingCode(
         "com.google.protobuf.MapEntry<$type_parameters$>\n"
         "$name$__ = input.readMessage(\n"
         "    $default_entry$.getParserForType(), extensionRegistry);\n"
-        "$name$_.getMutableMap().put(\n"
+        "internalGetMutable$capitalized_name$().getMutableMap().put(\n"
         "    $name$__.getKey(), $name$__.getValue());\n");
   }
 }
 
-void ImmutableMapFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  // Nothing to do here.
-}
-
 void ImmutableMapFieldGenerator::GenerateSerializationCode(
     io::Printer* printer) const {
   printer->Print(variables_,

src/google/protobuf/compiler/java/map_field.h

@@ -55,8 +55,7 @@ class ImmutableMapFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(

src/google/protobuf/compiler/java/map_field_lite.cc

@@ -873,13 +873,13 @@ void ImmutableMapFieldLiteGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(
       variables_,
-      "$kt_deprecation$ val $kt_name$: "
+      "$kt_deprecation$ public val $kt_name$: "
       "com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  @kotlin.jvm.JvmSynthetic\n"
@@ -892,7 +892,7 @@ void ImmutableMapFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(
       variables_,
       "@JvmName(\"put$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .put(key: $kt_key_type$, value: $kt_value_type$) {\n"
       "     $kt_dsl_builder$.${$put$capitalized_name$$}$(key, value)\n"
@@ -904,7 +904,7 @@ void ImmutableMapFieldLiteGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"set$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslMap"
+      "public inline operator fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .set(key: $kt_key_type$, value: $kt_value_type$) {\n"
       "     put(key, value)\n"
@@ -915,7 +915,7 @@ void ImmutableMapFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"remove$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .remove(key: $kt_key_type$) {\n"
       "     $kt_dsl_builder$.${$remove$capitalized_name$$}$(key)\n"
@@ -926,7 +926,7 @@ void ImmutableMapFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"putAll$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .putAll(map: kotlin.collections.Map<$kt_key_type$, $kt_value_type$>) "
       "{\n"
@@ -938,7 +938,7 @@ void ImmutableMapFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@JvmName(\"clear$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslMap"
+      "public fun com.google.protobuf.kotlin.DslMap"
       "<$kt_key_type$, $kt_value_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
       "  .clear() {\n"
       "     $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/java/message.cc

@@ -42,6 +42,7 @@
 
 #include "google/protobuf/io/coded_stream.h"
 #include "google/protobuf/io/printer.h"
+#include "google/protobuf/descriptor.h"
 #include "google/protobuf/wire_format.h"
 #include "google/protobuf/stubs/strutil.h"
 #include "absl/strings/ascii.h"
@@ -389,6 +390,7 @@ void ImmutableMessageGenerator::Generate(io::Printer* printer) {
                  "}\n"
                  "\n");
 
+  // TODO(b/248149118): Remove this superfluous override.
   printer->Print(
       "@java.lang.Override\n"
       "public final com.google.protobuf.UnknownFieldSet\n"
@@ -396,10 +398,6 @@ void ImmutableMessageGenerator::Generate(io::Printer* printer) {
       "  return this.unknownFields;\n"
       "}\n");
 
-  if (context_->HasGeneratedMethods(descriptor_)) {
-    GenerateParsingConstructor(printer);
-  }
-
   GenerateDescriptorMethods(printer);
 
   // Nested types
@@ -639,9 +637,9 @@ void ImmutableMessageGenerator::GenerateMessageSerializationMethods(
                                        sorted_fields.get());
 
   if (descriptor_->options().message_set_wire_format()) {
-    printer->Print("unknownFields.writeAsMessageSetTo(output);\n");
+    printer->Print("getUnknownFields().writeAsMessageSetTo(output);\n");
   } else {
-    printer->Print("unknownFields.writeTo(output);\n");
+    printer->Print("getUnknownFields().writeTo(output);\n");
   }
 
   printer->Outdent();
@@ -670,9 +668,10 @@ void ImmutableMessageGenerator::GenerateMessageSerializationMethods(
   }
 
   if (descriptor_->options().message_set_wire_format()) {
-    printer->Print("size += unknownFields.getSerializedSizeAsMessageSet();\n");
+    printer->Print(
+        "size += getUnknownFields().getSerializedSizeAsMessageSet();\n");
   } else {
-    printer->Print("size += unknownFields.getSerializedSize();\n");
+    printer->Print("size += getUnknownFields().getSerializedSize();\n");
   }
 
   printer->Print(
@@ -1064,7 +1063,8 @@ void ImmutableMessageGenerator::GenerateEqualsAndHashCode(
   // false for non-canonical ordering when running in LITE_RUNTIME but it's
   // the best we can do.
   printer->Print(
-      "if (!unknownFields.equals(other.unknownFields)) return false;\n");
+      "if (!getUnknownFields().equals(other.getUnknownFields())) return "
+      "false;\n");
   if (descriptor_->extension_range_count() > 0) {
     printer->Print(
         "if (!getExtensionFields().equals(other.getExtensionFields()))\n"
@@ -1138,7 +1138,7 @@ void ImmutableMessageGenerator::GenerateEqualsAndHashCode(
     printer->Print("hash = hashFields(hash, getExtensionFields());\n");
   }
 
-  printer->Print("hash = (29 * hash) + unknownFields.hashCode();\n");
+  printer->Print("hash = (29 * hash) + getUnknownFields().hashCode();\n");
   printer->Print(
       "memoizedHashCode = hash;\n"
       "return hash;\n");
@@ -1163,189 +1163,33 @@ void ImmutableMessageGenerator::GenerateExtensionRegistrationCode(
   }
 }
 
-// ===================================================================
-void ImmutableMessageGenerator::GenerateParsingConstructor(
-    io::Printer* printer) {
-  std::unique_ptr<const FieldDescriptor*[]> sorted_fields(
-      SortFieldsByNumber(descriptor_));
-
-  printer->Print(
-      "private $classname$(\n"
-      "    com.google.protobuf.CodedInputStream input,\n"
-      "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
-      "    throws com.google.protobuf.InvalidProtocolBufferException {\n",
-      "classname", descriptor_->name());
-  printer->Indent();
-
-  // Initialize all fields to default.
-  printer->Print(
-      "this();\n"
-      "if (extensionRegistry == null) {\n"
-      "  throw new java.lang.NullPointerException();\n"
-      "}\n");
-
-  // Use builder bits to track mutable repeated fields.
-  int totalBuilderBits = 0;
-  for (int i = 0; i < descriptor_->field_count(); i++) {
-    const ImmutableFieldGenerator& field =
-        field_generators_.get(descriptor_->field(i));
-    totalBuilderBits += field.GetNumBitsForBuilder();
-  }
-  int totalBuilderInts = (totalBuilderBits + 31) / 32;
-  for (int i = 0; i < totalBuilderInts; i++) {
-    printer->Print("int mutable_$bit_field_name$ = 0;\n", "bit_field_name",
-                   GetBitFieldName(i));
-  }
-
-  printer->Print(
-      "com.google.protobuf.UnknownFieldSet.Builder unknownFields =\n"
-      "    com.google.protobuf.UnknownFieldSet.newBuilder();\n");
-
-  printer->Print("try {\n");
-  printer->Indent();
-
-  printer->Print(
-      "boolean done = false;\n"
-      "while (!done) {\n");
-  printer->Indent();
-
-  printer->Print(
-      "int tag = input.readTag();\n"
-      "switch (tag) {\n");
-  printer->Indent();
-
-  printer->Print(
-      "case 0:\n"  // zero signals EOF / limit reached
-      "  done = true;\n"
-      "  break;\n");
-
-  for (int i = 0; i < descriptor_->field_count(); i++) {
-    const FieldDescriptor* field = sorted_fields[i];
-    uint32_t tag = WireFormatLite::MakeTag(
-        field->number(), WireFormat::WireTypeForFieldType(field->type()));
-
-    printer->Print("case $tag$: {\n", "tag",
-                   absl::StrCat(static_cast<int32_t>(tag)));
-    printer->Indent();
-
-    field_generators_.get(field).GenerateParsingCode(printer);
-
-    printer->Outdent();
-    printer->Print(
-        "  break;\n"
-        "}\n");
-
-    if (field->is_packable()) {
-      // To make packed = true wire compatible, we generate parsing code from a
-      // packed version of this field regardless of field->options().packed().
-      uint32_t packed_tag = WireFormatLite::MakeTag(
-          field->number(), WireFormatLite::WIRETYPE_LENGTH_DELIMITED);
-      printer->Print("case $tag$: {\n", "tag",
-                     absl::StrCat(static_cast<int32_t>(packed_tag)));
-      printer->Indent();
-
-      field_generators_.get(field).GenerateParsingCodeFromPacked(printer);
-
-      printer->Outdent();
-      printer->Print(
-          "  break;\n"
-          "}\n");
-    }
-  }
-
-  printer->Print(
-      "default: {\n"
-      "  if (!parseUnknownField(\n"
-      "      input, unknownFields, extensionRegistry, tag)) {\n"
-      "    done = true;\n"  // it's an endgroup tag
-      "  }\n"
-      "  break;\n"
-      "}\n");
-
-  printer->Outdent();
-  printer->Outdent();
-  printer->Print(
-      "  }\n"  // switch (tag)
-      "}\n");  // while (!done)
-
-  printer->Outdent();
-  printer->Print(
-      "} catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
-      "  throw e.setUnfinishedMessage(this);\n"
-      "} catch (com.google.protobuf.UninitializedMessageException e) {\n"
-      "  throw "
-      "e.asInvalidProtocolBufferException().setUnfinishedMessage(this);\n"
-      "} catch (java.io.IOException e) {\n"
-      "  throw new com.google.protobuf.InvalidProtocolBufferException(\n"
-      "      e).setUnfinishedMessage(this);\n"
-      "} finally {\n");
-  printer->Indent();
-
-  // Make repeated field list immutable.
-  for (int i = 0; i < descriptor_->field_count(); i++) {
-    const FieldDescriptor* field = sorted_fields[i];
-    field_generators_.get(field).GenerateParsingDoneCode(printer);
-  }
-
-  // Make unknown fields immutable.
-  printer->Print("this.unknownFields = unknownFields.build();\n");
-
-  // Make extensions immutable.
-  printer->Print("makeExtensionsImmutable();\n");
-
-  printer->Outdent();
-  printer->Outdent();
-  printer->Print(
-      "  }\n"  // finally
-      "}\n");
-}
-
 // ===================================================================
 void ImmutableMessageGenerator::GenerateParser(io::Printer* printer) {
   printer->Print(
       "$visibility$ static final com.google.protobuf.Parser<$classname$>\n"
-      "    PARSER = new com.google.protobuf.AbstractParser<$classname$>() {\n",
-      "visibility",
-      ExposePublicParser(descriptor_->file()) ? "@java.lang.Deprecated public"
-                                              : "private",
-      "classname", descriptor_->name());
-  printer->Indent();
-  printer->Print(
-      "@java.lang.Override\n"
-      "public $classname$ parsePartialFrom(\n"
-      "    com.google.protobuf.CodedInputStream input,\n"
-      "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
-      "    throws com.google.protobuf.InvalidProtocolBufferException {\n",
-      "classname", descriptor_->name());
-  if (context_->HasGeneratedMethods(descriptor_)) {
-    printer->Print("  return new $classname$(input, extensionRegistry);\n",
-                   "classname", descriptor_->name());
-  } else {
-    // When parsing constructor isn't generated, use builder to parse
-    // messages. Note, will fallback to use reflection based mergeFieldFrom()
-    // in AbstractMessage.Builder.
-    printer->Indent();
-    printer->Print(
-        "Builder builder = newBuilder();\n"
-        "try {\n"
-        "  builder.mergeFrom(input, extensionRegistry);\n"
-        "} catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
-        "  throw e.setUnfinishedMessage(builder.buildPartial());\n"
-        "} catch (java.io.IOException e) {\n"
-        "  throw new com.google.protobuf.InvalidProtocolBufferException(\n"
-        "      e.getMessage()).setUnfinishedMessage(\n"
-        "          builder.buildPartial());\n"
-        "}\n"
-        "return builder.buildPartial();\n");
-    printer->Outdent();
-  }
-  printer->Print("}\n");
-  printer->Outdent();
-  printer->Print(
+      "    PARSER = new com.google.protobuf.AbstractParser<$classname$>() {\n"
+      "  @java.lang.Override\n"
+      "  public $classname$ parsePartialFrom(\n"
+      "      com.google.protobuf.CodedInputStream input,\n"
+      "      com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
+      "      throws com.google.protobuf.InvalidProtocolBufferException {\n"
+      "    Builder builder = newBuilder();\n"
+      "    try {\n"
+      "      builder.mergeFrom(input, extensionRegistry);\n"
+      "    } catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
+      "      throw e.setUnfinishedMessage(builder.buildPartial());\n"
+      "    } catch (com.google.protobuf.UninitializedMessageException e) {\n"
+      "      throw "
+      "e.asInvalidProtocolBufferException().setUnfinishedMessage(builder."
+      "buildPartial());\n"
+      "    } catch (java.io.IOException e) {\n"
+      "      throw new com.google.protobuf.InvalidProtocolBufferException(e)\n"
+      "          .setUnfinishedMessage(builder.buildPartial());\n"
+      "    }\n"
+      "    return builder.buildPartial();\n"
+      "  }\n"
       "};\n"
-      "\n");
-
-  printer->Print(
+      "\n"
       "public static com.google.protobuf.Parser<$classname$> parser() {\n"
       "  return PARSER;\n"
       "}\n"
@@ -1355,6 +1199,9 @@ void ImmutableMessageGenerator::GenerateParser(io::Printer* printer) {
       "  return PARSER;\n"
       "}\n"
       "\n",
+      "visibility",
+      ExposePublicParser(descriptor_->file()) ? "@java.lang.Deprecated public"
+                                              : "private",
       "classname", descriptor_->name());
 }
 
@@ -1409,10 +1256,10 @@ void ImmutableMessageGenerator::GenerateKotlinDsl(io::Printer* printer) const {
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
       "@com.google.protobuf.kotlin.ProtoDslMarker\n");
   printer->Print(
-      "class Dsl private constructor(\n"
+      "public class Dsl private constructor(\n"
       "  private val _builder: $message$.Builder\n"
       ") {\n"
-      "  companion object {\n"
+      "  public companion object {\n"
       "    @kotlin.jvm.JvmSynthetic\n"
       "    @kotlin.PublishedApi\n"
       "    internal fun _create(builder: $message$.Builder): Dsl = "
@@ -1435,10 +1282,10 @@ void ImmutableMessageGenerator::GenerateKotlinDsl(io::Printer* printer) const {
 
   for (auto oneof : oneofs_) {
     printer->Print(
-        "val $oneof_name$Case: $message$.$oneof_capitalized_name$Case\n"
+        "public val $oneof_name$Case: $message$.$oneof_capitalized_name$Case\n"
         "  @JvmName(\"get$oneof_capitalized_name$Case\")\n"
         "  get() = _builder.get$oneof_capitalized_name$Case()\n\n"
-        "fun clear$oneof_capitalized_name$() {\n"
+        "public fun clear$oneof_capitalized_name$() {\n"
         "  _builder.clear$oneof_capitalized_name$()\n"
         "}\n",
         "oneof_name", context_->GetOneofGeneratorInfo(oneof)->name,
@@ -1466,7 +1313,7 @@ void ImmutableMessageGenerator::GenerateKotlinMembers(
   }
 
   printer->Print(
-      "inline fun $camelcase_name$(block: $message_kt$.Dsl.() -> "
+      "public inline fun $camelcase_name$(block: $message_kt$.Dsl.() -> "
       "kotlin.Unit): "
       "$message$ "
       "=\n"
@@ -1480,7 +1327,7 @@ void ImmutableMessageGenerator::GenerateKotlinMembers(
       EscapeKotlinKeywords(name_resolver_->GetClassName(descriptor_, true)));
 
   WriteMessageDocComment(printer, descriptor_, /* kdoc */ true);
-  printer->Print("object $name$Kt {\n", "name", descriptor_->name());
+  printer->Print("public object $name$Kt {\n", "name", descriptor_->name());
   printer->Indent();
   GenerateKotlinDsl(printer);
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
@@ -1501,7 +1348,7 @@ void ImmutableMessageGenerator::GenerateTopLevelKotlinMembers(
   }
 
   printer->Print(
-      "inline fun $message$.copy(block: $message_kt$.Dsl.() -> "
+      "public inline fun $message$.copy(block: $message_kt$.Dsl.() -> "
       "kotlin.Unit): $message$ =\n"
       "  $message_kt$.Dsl._create(this.toBuilder()).apply { block() "
       "}._build()\n\n",
@@ -1546,7 +1393,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@Suppress(\"UNCHECKED_CAST\")\n"
       "@kotlin.jvm.JvmSynthetic\n"
-      "operator fun <T : kotlin.Any> get(extension: "
+      "public operator fun <T : kotlin.Any> get(extension: "
       "com.google.protobuf.ExtensionLite<$message$, T>): T {\n"
       "  return if (extension.isRepeated) {\n"
       "    get(extension as com.google.protobuf.ExtensionLite<$message$, "
@@ -1562,7 +1409,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
       "@kotlin.jvm.JvmName(\"-getRepeatedExtension\")\n"
-      "operator fun <E : kotlin.Any> get(\n"
+      "public operator fun <E : kotlin.Any> get(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, List<E>>\n"
       "): com.google.protobuf.kotlin.ExtensionList<E, $message$> {\n"
       "  return com.google.protobuf.kotlin.ExtensionList(extension, "
@@ -1572,7 +1419,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "operator fun contains(extension: "
+      "public operator fun contains(extension: "
       "com.google.protobuf.ExtensionLite<$message$, *>): "
       "Boolean {\n"
       "  return _builder.hasExtension(extension)\n"
@@ -1581,7 +1428,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "fun clear(extension: "
+      "public fun clear(extension: "
       "com.google.protobuf.ExtensionLite<$message$, *>) "
       "{\n"
       "  _builder.clearExtension(extension)\n"
@@ -1601,7 +1448,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <T : Comparable<T>> set(\n"
+      "public inline operator fun <T : Comparable<T>> set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, T>,\n"
       "  value: T\n"
       ") {\n"
@@ -1612,7 +1459,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun set(\n"
+      "public inline operator fun set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, "
       "com.google.protobuf.ByteString>,\n"
       "  value: com.google.protobuf.ByteString\n"
@@ -1624,7 +1471,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <T : com.google.protobuf.MessageLite> set(\n"
+      "public inline operator fun <T : com.google.protobuf.MessageLite> set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, T>,\n"
       "  value: T\n"
       ") {\n"
@@ -1634,7 +1481,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "fun <E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
+      "public fun <E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.add(value: E) {\n"
       "  _builder.addExtension(this.extension, value)\n"
       "}\n\n",
@@ -1643,7 +1490,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <E : kotlin.Any> "
+      "public inline operator fun <E : kotlin.Any> "
       "com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.plusAssign"
       "(value: E) {\n"
@@ -1653,7 +1500,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "fun <E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
+      "public fun <E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.addAll(values: Iterable<E>) {\n"
       "  for (value in values) {\n"
       "    add(value)\n"
@@ -1664,7 +1511,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <E : kotlin.Any> "
+      "public inline operator fun <E : kotlin.Any> "
       "com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.plusAssign(values: "
       "Iterable<E>) {\n"
@@ -1674,7 +1521,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "operator fun <E : kotlin.Any> "
+      "public operator fun <E : kotlin.Any> "
       "com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.set(index: Int, value: "
       "E) {\n"
@@ -1685,7 +1532,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline fun com.google.protobuf.kotlin.ExtensionList<*, "
+      "public inline fun com.google.protobuf.kotlin.ExtensionList<*, "
       "$message$>.clear() {\n"
       "  clear(extension)\n"
       "}\n\n",

src/google/protobuf/compiler/java/message_builder.cc

@@ -63,6 +63,9 @@ namespace protobuf {
 namespace compiler {
 namespace java {
 
+using internal::WireFormat;
+using internal::WireFormatLite;
+
 namespace {
 std::string MapValueImmutableClassdName(const Descriptor* descriptor,
                                         ClassNameResolver* name_resolver) {
@@ -292,43 +295,60 @@ void MessageBuilderGenerator::GenerateDescriptorMethods(io::Printer* printer) {
 
 void MessageBuilderGenerator::GenerateCommonBuilderMethods(
     io::Printer* printer) {
+  bool need_maybe_force_builder_init = false;
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+    if (descriptor_->field(i)->message_type() != nullptr &&
+        !IsRealOneof(descriptor_->field(i)) &&
+        HasHasbit(descriptor_->field(i))) {
+      need_maybe_force_builder_init = true;
+      break;
+    }
+  }
+
+  const char* force_builder_init = need_maybe_force_builder_init
+                                       ? "  maybeForceBuilderInitialization();"
+                                       : "";
+
   printer->Print(
       "// Construct using $classname$.newBuilder()\n"
       "private Builder() {\n"
-      "  maybeForceBuilderInitialization();\n"
+      "$force_builder_init$\n"
       "}\n"
       "\n",
-      "classname", name_resolver_->GetImmutableClassName(descriptor_));
+      "classname", name_resolver_->GetImmutableClassName(descriptor_),
+      "force_builder_init", force_builder_init);
 
   printer->Print(
       "private Builder(\n"
       "    com.google.protobuf.GeneratedMessage$ver$.BuilderParent parent) {\n"
       "  super(parent);\n"
-      "  maybeForceBuilderInitialization();\n"
+      "$force_builder_init$\n"
       "}\n",
       "classname", name_resolver_->GetImmutableClassName(descriptor_), "ver",
-      GeneratedCodeVersionSuffix());
+      GeneratedCodeVersionSuffix(), "force_builder_init", force_builder_init);
 
-  printer->Print(
-      "private void maybeForceBuilderInitialization() {\n"
-      "  if (com.google.protobuf.GeneratedMessage$ver$\n"
-      "          .alwaysUseFieldBuilders) {\n",
-      "ver", GeneratedCodeVersionSuffix());
+  if (need_maybe_force_builder_init) {
+    printer->Print(
+        "private void maybeForceBuilderInitialization() {\n"
+        "  if (com.google.protobuf.GeneratedMessage$ver$\n"
+        "          .alwaysUseFieldBuilders) {\n",
+        "ver", GeneratedCodeVersionSuffix());
 
-  printer->Indent();
-  printer->Indent();
-  for (int i = 0; i < descriptor_->field_count(); i++) {
-    if (!IsRealOneof(descriptor_->field(i))) {
-      field_generators_.get(descriptor_->field(i))
-          .GenerateFieldBuilderInitializationCode(printer);
+    printer->Indent();
+    printer->Indent();
+    for (int i = 0; i < descriptor_->field_count(); i++) {
+      if (!IsRealOneof(descriptor_->field(i))) {
+        field_generators_.get(descriptor_->field(i))
+            .GenerateFieldBuilderInitializationCode(printer);
+      }
     }
-  }
-  printer->Outdent();
-  printer->Outdent();
+    printer->Outdent();
+    printer->Outdent();
 
-  printer->Print(
-      "  }\n"
-      "}\n");
+    printer->Print(
+        "  }\n"
+        "}\n");
+  }
 
   printer->Print(
       "@java.lang.Override\n"
@@ -338,10 +358,8 @@ void MessageBuilderGenerator::GenerateCommonBuilderMethods(
   printer->Indent();
 
   for (int i = 0; i < descriptor_->field_count(); i++) {
-    if (!IsRealOneof(descriptor_->field(i))) {
-      field_generators_.get(descriptor_->field(i))
-          .GenerateBuilderClearCode(printer);
-    }
+    field_generators_.get(descriptor_->field(i))
+        .GenerateBuilderClearCode(printer);
   }
 
   for (auto oneof : oneofs_) {
@@ -584,7 +602,7 @@ void MessageBuilderGenerator::GenerateCommonBuilderMethods(
       printer->Print("  this.mergeExtensionFields(other);\n");
     }
 
-    printer->Print("  this.mergeUnknownFields(other.unknownFields);\n");
+    printer->Print("  this.mergeUnknownFields(other.getUnknownFields());\n");
 
     printer->Print("  onChanged();\n");
 
@@ -605,20 +623,92 @@ void MessageBuilderGenerator::GenerateBuilderParsingMethods(
       "    com.google.protobuf.CodedInputStream input,\n"
       "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
       "    throws java.io.IOException {\n"
-      "  $classname$ parsedMessage = null;\n"
+      "  if (extensionRegistry == null) {\n"
+      "    throw new java.lang.NullPointerException();\n"
+      "  }\n"
       "  try {\n"
-      "    parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);\n"
+      "    boolean done = false;\n"
+      "    while (!done) {\n"
+      "      int tag = input.readTag();\n"
+      "      switch (tag) {\n"
+      "        case 0:\n"  // zero signals EOF / limit reached
+      "          done = true;\n"
+      "          break;\n");
+  printer->Indent();  // method
+  printer->Indent();  // try
+  printer->Indent();  // while
+  printer->Indent();  // switch
+  GenerateBuilderFieldParsingCases(printer);
+  printer->Outdent();  // switch
+  printer->Outdent();  // while
+  printer->Outdent();  // try
+  printer->Outdent();  // method
+  printer->Print(
+      "        default: {\n"
+      "          if (!super.parseUnknownField(input, extensionRegistry, tag)) "
+      "{\n"
+      "            done = true; // was an endgroup tag\n"
+      "          }\n"
+      "          break;\n"
+      "        } // default:\n"
+      "      } // switch (tag)\n"
+      "    } // while (!done)\n"
       "  } catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
-      "    parsedMessage = ($classname$) e.getUnfinishedMessage();\n"
       "    throw e.unwrapIOException();\n"
       "  } finally {\n"
-      "    if (parsedMessage != null) {\n"
-      "      mergeFrom(parsedMessage);\n"
-      "    }\n"
-      "  }\n"
+      "    onChanged();\n"
+      "  } // finally\n"
       "  return this;\n"
-      "}\n",
-      "classname", name_resolver_->GetImmutableClassName(descriptor_));
+      "}\n");
+}
+
+void MessageBuilderGenerator::GenerateBuilderFieldParsingCases(
+    io::Printer* printer) {
+  std::unique_ptr<const FieldDescriptor*[]> sorted_fields(
+      SortFieldsByNumber(descriptor_));
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+    const FieldDescriptor* field = sorted_fields[i];
+    GenerateBuilderFieldParsingCase(printer, field);
+    if (field->is_packable()) {
+      GenerateBuilderPackedFieldParsingCase(printer, field);
+    }
+  }
+}
+
+void MessageBuilderGenerator::GenerateBuilderFieldParsingCase(
+    io::Printer* printer, const FieldDescriptor* field) {
+  uint32_t tag = WireFormatLite::MakeTag(
+      field->number(), WireFormat::WireTypeForFieldType(field->type()));
+  std::string tagString = absl::StrCat(static_cast<int32_t>(tag));
+  printer->Print("case $tag$: {\n", "tag", tagString);
+  printer->Indent();
+
+  field_generators_.get(field).GenerateBuilderParsingCode(printer);
+
+  printer->Outdent();
+  printer->Print(
+      "  break;\n"
+      "} // case $tag$\n",
+      "tag", tagString);
+}
+
+void MessageBuilderGenerator::GenerateBuilderPackedFieldParsingCase(
+    io::Printer* printer, const FieldDescriptor* field) {
+  // To make packed = true wire compatible, we generate parsing code from a
+  // packed version of this field regardless of field->options().packed().
+  uint32_t tag = WireFormatLite::MakeTag(
+      field->number(), WireFormatLite::WIRETYPE_LENGTH_DELIMITED);
+  std::string tagString = absl::StrCat(static_cast<int32_t>(tag));
+  printer->Print("case $tag$: {\n", "tag", tagString);
+  printer->Indent();
+
+  field_generators_.get(field).GenerateBuilderParsingCodeFromPacked(printer);
+
+  printer->Outdent();
+  printer->Print(
+      "  break;\n"
+      "} // case $tag$\n",
+      "tag", tagString);
 }
 
 // ===================================================================

src/google/protobuf/compiler/java/message_builder.h

@@ -73,6 +73,11 @@ class MessageBuilderGenerator {
   void GenerateCommonBuilderMethods(io::Printer* printer);
   void GenerateDescriptorMethods(io::Printer* printer);
   void GenerateBuilderParsingMethods(io::Printer* printer);
+  void GenerateBuilderFieldParsingCases(io::Printer* printer);
+  void GenerateBuilderFieldParsingCase(io::Printer* printer,
+                                       const FieldDescriptor* field);
+  void GenerateBuilderPackedFieldParsingCase(io::Printer* printer,
+                                             const FieldDescriptor* field);
   void GenerateIsInitialized(io::Printer* printer);
 
   const Descriptor* descriptor_;

src/google/protobuf/compiler/java/message_field.cc

@@ -116,13 +116,6 @@ void SetMessageVariables(const FieldDescriptor* descriptor, int messageBitIndex,
   (*variables)["set_mutable_bit_builder"] = GenerateSetBit(builderBitIndex);
   (*variables)["clear_mutable_bit_builder"] = GenerateClearBit(builderBitIndex);
 
-  // For repeated fields, one bit is used for whether the array is immutable
-  // in the parsing constructor.
-  (*variables)["get_mutable_bit_parser"] =
-      GenerateGetBitMutableLocal(builderBitIndex);
-  (*variables)["set_mutable_bit_parser"] =
-      GenerateSetBitMutableLocal(builderBitIndex);
-
   (*variables)["get_has_field_bit_from_local"] =
       GenerateGetBitFromLocal(builderBitIndex);
   (*variables)["set_has_field_bit_to_local"] =
@@ -426,7 +419,7 @@ void ImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: $kt_type$\n"
+                 "$kt_deprecation$public var $kt_name$: $kt_type$\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -437,7 +430,7 @@ void ImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -445,7 +438,7 @@ void ImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
                                /* builder */ false, /* kdoc */ true);
   printer->Print(
       variables_,
-      "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+      "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
       "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
       "}\n");
 
@@ -455,7 +448,7 @@ void ImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
 void ImmutableMessageFieldGenerator::GenerateKotlinOrNull(io::Printer* printer) const {
   if (descriptor_->has_optional_keyword()) {
     printer->Print(variables_,
-                   "val $classname$Kt.Dsl.$name$OrNull: $kt_type$?\n"
+                   "public val $classname$Kt.Dsl.$name$OrNull: $kt_type$?\n"
                    "  get() = $kt_dsl_builder$.$name$OrNull\n");
   }
 }
@@ -510,35 +503,21 @@ void ImmutableMessageFieldGenerator::GenerateBuildingCode(
   }
 }
 
-void ImmutableMessageFieldGenerator::GenerateParsingCode(
+void ImmutableMessageFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
-  printer->Print(variables_,
-                 "$type$.Builder subBuilder = null;\n"
-                 "if ($is_field_present_message$) {\n"
-                 "  subBuilder = $name$_.toBuilder();\n"
-                 "}\n");
-
   if (GetType(descriptor_) == FieldDescriptor::TYPE_GROUP) {
     printer->Print(variables_,
-                   "$name$_ = input.readGroup($number$, $type$.$get_parser$,\n"
-                   "    extensionRegistry);\n");
+                   "input.readGroup($number$,\n"
+                   "    get$capitalized_name$FieldBuilder().getBuilder(),\n"
+                   "    extensionRegistry);\n"
+                   "$set_has_field_bit_builder$\n");
   } else {
     printer->Print(variables_,
-                   "$name$_ = input.readMessage($type$.$get_parser$, "
-                   "extensionRegistry);\n");
+                   "input.readMessage(\n"
+                   "    get$capitalized_name$FieldBuilder().getBuilder(),\n"
+                   "    extensionRegistry);\n"
+                   "$set_has_field_bit_builder$\n");
   }
-
-  printer->Print(variables_,
-                 "if (subBuilder != null) {\n"
-                 "  subBuilder.mergeFrom($name$_);\n"
-                 "  $name$_ = subBuilder.buildPartial();\n"
-                 "}\n"
-                 "$set_has_field_bit_message$\n");
-}
-
-void ImmutableMessageFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  // noop for messages.
 }
 
 void ImmutableMessageFieldGenerator::GenerateSerializationCode(
@@ -791,6 +770,15 @@ void ImmutableMessageOneofFieldGenerator::GenerateBuilderMembers(
   printer->Annotate("{", "}", descriptor_);
 }
 
+void ImmutableMessageOneofFieldGenerator::GenerateBuilderClearCode(
+    io::Printer* printer) const {
+  // Make sure the builder gets cleared.
+  printer->Print(variables_,
+                 "if ($name$Builder_ != null) {\n"
+                 "  $name$Builder_.clear();\n"
+                 "}\n");
+}
+
 void ImmutableMessageOneofFieldGenerator::GenerateBuildingCode(
     io::Printer* printer) const {
   printer->Print(variables_, "if ($has_oneof_case_message$) {\n");
@@ -811,32 +799,21 @@ void ImmutableMessageOneofFieldGenerator::GenerateMergingCode(
                  "merge$capitalized_name$(other.get$capitalized_name$());\n");
 }
 
-void ImmutableMessageOneofFieldGenerator::GenerateParsingCode(
+void ImmutableMessageOneofFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
-  printer->Print(variables_,
-                 "$type$.Builder subBuilder = null;\n"
-                 "if ($has_oneof_case_message$) {\n"
-                 "  subBuilder = (($type$) $oneof_name$_).toBuilder();\n"
-                 "}\n");
-
   if (GetType(descriptor_) == FieldDescriptor::TYPE_GROUP) {
-    printer->Print(
-        variables_,
-        "$oneof_name$_ = input.readGroup($number$, $type$.$get_parser$,\n"
-        "    extensionRegistry);\n");
+    printer->Print(variables_,
+                   "input.readGroup($number$,\n"
+                   "    get$capitalized_name$FieldBuilder().getBuilder(),\n"
+                   "    extensionRegistry);\n"
+                   "$set_oneof_case_message$;\n");
   } else {
-    printer->Print(
-        variables_,
-        "$oneof_name$_ =\n"
-        "    input.readMessage($type$.$get_parser$, extensionRegistry);\n");
+    printer->Print(variables_,
+                   "input.readMessage(\n"
+                   "    get$capitalized_name$FieldBuilder().getBuilder(),\n"
+                   "    extensionRegistry);\n"
+                   "$set_oneof_case_message$;\n");
   }
-
-  printer->Print(variables_,
-                 "if (subBuilder != null) {\n"
-                 "  subBuilder.mergeFrom(($type$) $oneof_name$_);\n"
-                 "  $oneof_name$_ = subBuilder.buildPartial();\n"
-                 "}\n");
-  printer->Print(variables_, "$set_oneof_case_message$;\n");
 }
 
 void ImmutableMessageOneofFieldGenerator::GenerateSerializationCode(
@@ -1287,10 +1264,12 @@ void RepeatedImmutableMessageFieldGenerator::GenerateInitializationCode(
 void RepeatedImmutableMessageFieldGenerator::GenerateBuilderClearCode(
     io::Printer* printer) const {
   PrintNestedBuilderCondition(printer,
-                              "$name$_ = java.util.Collections.emptyList();\n"
-                              "$clear_mutable_bit_builder$;\n",
+                              "$name$_ = java.util.Collections.emptyList();\n",
 
+                              "$name$_ = null;\n"
                               "$name$Builder_.clear();\n");
+
+  printer->Print(variables_, "$clear_mutable_bit_builder$;\n");
 }
 
 void RepeatedImmutableMessageFieldGenerator::GenerateMergingCode(
@@ -1345,34 +1324,25 @@ void RepeatedImmutableMessageFieldGenerator::GenerateBuildingCode(
       "result.$name$_ = $name$Builder_.build();\n");
 }
 
-void RepeatedImmutableMessageFieldGenerator::GenerateParsingCode(
+void RepeatedImmutableMessageFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
-  printer->Print(variables_,
-                 "if (!$get_mutable_bit_parser$) {\n"
-                 "  $name$_ = new java.util.ArrayList<$type$>();\n"
-                 "  $set_mutable_bit_parser$;\n"
-                 "}\n");
-
   if (GetType(descriptor_) == FieldDescriptor::TYPE_GROUP) {
-    printer->Print(
-        variables_,
-        "$name$_.add(input.readGroup($number$, $type$.$get_parser$,\n"
-        "    extensionRegistry));\n");
+    printer->Print(variables_,
+                   "$type$ m =\n"
+                   "    input.readGroup($number$,\n"
+                   "        $type$.$get_parser$,\n"
+                   "        extensionRegistry);\n");
   } else {
-    printer->Print(
-        variables_,
-        "$name$_.add(\n"
-        "    input.readMessage($type$.$get_parser$, extensionRegistry));\n");
+    printer->Print(variables_,
+                   "$type$ m =\n"
+                   "    input.readMessage(\n"
+                   "        $type$.$get_parser$,\n"
+                   "        extensionRegistry);\n");
   }
-}
-
-void RepeatedImmutableMessageFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  printer->Print(
-      variables_,
-      "if ($get_mutable_bit_parser$) {\n"
-      "  $name$_ = java.util.Collections.unmodifiableList($name$_);\n"
-      "}\n");
+  PrintNestedBuilderCondition(printer,
+                              "ensure$capitalized_name$IsMutable();\n"
+                              "$name$_.add(m);\n",
+                              "$name$Builder_.addMessage(m);\n");
 }
 
 void RepeatedImmutableMessageFieldGenerator::GenerateSerializationCode(
@@ -1425,12 +1395,12 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$ public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -1443,7 +1413,7 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: $kt_type$) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -1455,7 +1425,7 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: $kt_type$) {\n"
                  "  add(value)\n"
@@ -1466,7 +1436,7 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "addAll(values: kotlin.collections.Iterable<$kt_type$>) {\n"
                  "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -1479,7 +1449,7 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<$kt_type$>) {\n"
       "  addAll(values)\n"
@@ -1491,7 +1461,7 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: $kt_type$) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -1502,7 +1472,7 @@ void RepeatedImmutableMessageFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/java/message_field.h

@@ -79,8 +79,7 @@ class ImmutableMessageFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(
@@ -124,9 +123,10 @@ class ImmutableMessageOneofFieldGenerator
 
   void GenerateMembers(io::Printer* printer) const override;
   void GenerateBuilderMembers(io::Printer* printer) const override;
+  void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
 };
@@ -152,8 +152,7 @@ class RepeatedImmutableMessageFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(

src/google/protobuf/compiler/java/message_field_lite.cc

@@ -300,7 +300,7 @@ void ImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: $kt_type$\n"
+                 "$kt_deprecation$public var $kt_name$: $kt_type$\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -311,7 +311,7 @@ void ImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -319,7 +319,7 @@ void ImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
                                /* builder */ false, /* kdoc */ true);
   printer->Print(
       variables_,
-      "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+      "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
       "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
       "}\n");
   GenerateKotlinOrNull(printer);
@@ -328,7 +328,7 @@ void ImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
 void ImmutableMessageFieldLiteGenerator::GenerateKotlinOrNull(io::Printer* printer) const {
   if (descriptor_->has_optional_keyword()) {
     printer->Print(variables_,
-                   "val $classname$Kt.Dsl.$name$OrNull: $kt_type$?\n"
+                   "public val $classname$Kt.Dsl.$name$OrNull: $kt_type$?\n"
                    "  get() = $kt_dsl_builder$.$name$OrNull\n");
   }
 }
@@ -830,12 +830,12 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$ public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -848,7 +848,7 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: $kt_type$) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -860,7 +860,7 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: $kt_type$) {\n"
                  "  add(value)\n"
@@ -871,7 +871,7 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "addAll(values: kotlin.collections.Iterable<$kt_type$>) {\n"
                  "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -884,7 +884,7 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<$kt_type$>) {\n"
       "  addAll(values)\n"
@@ -896,7 +896,7 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: $kt_type$) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -907,7 +907,7 @@ void RepeatedImmutableMessageFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/java/message_lite.cc

@@ -759,10 +759,10 @@ void ImmutableMessageLiteGenerator::GenerateKotlinDsl(
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
       "@com.google.protobuf.kotlin.ProtoDslMarker\n");
   printer->Print(
-      "class Dsl private constructor(\n"
+      "public class Dsl private constructor(\n"
       "  private val _builder: $message$.Builder\n"
       ") {\n"
-      "  companion object {\n"
+      "  public companion object {\n"
       "    @kotlin.jvm.JvmSynthetic\n"
       "    @kotlin.PublishedApi\n"
       "    internal fun _create(builder: $message$.Builder): Dsl = "
@@ -785,10 +785,10 @@ void ImmutableMessageLiteGenerator::GenerateKotlinDsl(
 
   for (auto oneof : oneofs_) {
     printer->Print(
-        "val $oneof_name$Case: $message$.$oneof_capitalized_name$Case\n"
+        "public val $oneof_name$Case: $message$.$oneof_capitalized_name$Case\n"
         "  @JvmName(\"get$oneof_capitalized_name$Case\")\n"
         "  get() = _builder.get$oneof_capitalized_name$Case()\n\n"
-        "fun clear$oneof_capitalized_name$() {\n"
+        "public fun clear$oneof_capitalized_name$() {\n"
         "  _builder.clear$oneof_capitalized_name$()\n"
         "}\n",
         "oneof_name", context_->GetOneofGeneratorInfo(oneof)->name,
@@ -815,7 +815,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinMembers(
     printer->Print("@com.google.errorprone.annotations.CheckReturnValue\n");
   }
   printer->Print(
-      "inline fun $camelcase_name$(block: $message_kt$.Dsl.() -> "
+      "public inline fun $camelcase_name$(block: $message_kt$.Dsl.() -> "
       "kotlin.Unit): $message$ =\n"
       "  $message_kt$.Dsl._create($message$.newBuilder()).apply { block() "
       "}._build()\n",
@@ -827,7 +827,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinMembers(
       EscapeKotlinKeywords(name_resolver_->GetClassName(descriptor_, true)));
 
   WriteMessageDocComment(printer, descriptor_, /* kdoc */ true);
-  printer->Print("object $name$Kt {\n", "name", descriptor_->name());
+  printer->Print("public object $name$Kt {\n", "name", descriptor_->name());
   printer->Indent();
   GenerateKotlinDsl(printer);
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
@@ -845,7 +845,7 @@ void ImmutableMessageLiteGenerator::GenerateTopLevelKotlinMembers(
     printer->Print("@com.google.errorprone.annotations.CheckReturnValue\n");
   }
   printer->Print(
-      "inline fun $message$.copy(block: $message_kt$.Dsl.() -> "
+      "public inline fun $message$.copy(block: $message_kt$.Dsl.() -> "
       "kotlin.Unit): $message$ =\n"
       "  $message_kt$.Dsl._create(this.toBuilder()).apply { block() "
       "}._build()\n\n",
@@ -892,7 +892,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@Suppress(\"UNCHECKED_CAST\")\n"
       "@kotlin.jvm.JvmSynthetic\n"
-      "operator fun <T : kotlin.Any> get(extension: "
+      "public operator fun <T : kotlin.Any> get(extension: "
       "com.google.protobuf.ExtensionLite<$message$, T>): T {\n"
       "  return if (extension.isRepeated) {\n"
       "    get(extension as com.google.protobuf.ExtensionLite<$message$, "
@@ -908,7 +908,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
       "@kotlin.jvm.JvmName(\"-getRepeatedExtension\")\n"
-      "operator fun <E : kotlin.Any> get(\n"
+      "public operator fun <E : kotlin.Any> get(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, List<E>>\n"
       "): com.google.protobuf.kotlin.ExtensionList<E, $message$> {\n"
       "  return com.google.protobuf.kotlin.ExtensionList(extension, "
@@ -918,7 +918,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "operator fun contains(extension: "
+      "public operator fun contains(extension: "
       "com.google.protobuf.ExtensionLite<$message$, *>): "
       "Boolean {\n"
       "  return _builder.hasExtension(extension)\n"
@@ -927,7 +927,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "fun clear(extension: "
+      "public fun clear(extension: "
       "com.google.protobuf.ExtensionLite<$message$, *>) "
       "{\n"
       "  _builder.clearExtension(extension)\n"
@@ -947,7 +947,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <T : Comparable<T>> set(\n"
+      "public inline operator fun <T : Comparable<T>> set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, T>,\n"
       "  value: T\n"
       ") {\n"
@@ -958,7 +958,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun set(\n"
+      "public inline operator fun set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, "
       "com.google.protobuf.ByteString>,\n"
       "  value: com.google.protobuf.ByteString\n"
@@ -970,7 +970,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <T : com.google.protobuf.MessageLite> set(\n"
+      "public inline operator fun <T : com.google.protobuf.MessageLite> set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, T>,\n"
       "  value: T\n"
       ") {\n"
@@ -980,7 +980,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "fun<E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
+      "public fun<E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.add(value: E) {\n"
       "  _builder.addExtension(this.extension, value)\n"
       "}\n\n",
@@ -989,7 +989,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <E : kotlin.Any> "
+      "public inline operator fun <E : kotlin.Any> "
       "com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.plusAssign"
       "(value: E) {\n"
@@ -999,7 +999,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "fun<E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
+      "public fun<E : kotlin.Any> com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.addAll(values: Iterable<E>) {\n"
       "  for (value in values) {\n"
       "    add(value)\n"
@@ -1010,7 +1010,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <E : kotlin.Any> "
+      "public inline operator fun <E : kotlin.Any> "
       "com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.plusAssign(values: "
       "Iterable<E>) {\n"
@@ -1020,7 +1020,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
 
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
-      "operator fun <E : kotlin.Any> "
+      "public operator fun <E : kotlin.Any> "
       "com.google.protobuf.kotlin.ExtensionList<E, "
       "$message$>.set(index: Int, value: "
       "E) {\n"
@@ -1031,7 +1031,7 @@ void ImmutableMessageLiteGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline fun com.google.protobuf.kotlin.ExtensionList<*, "
+      "public inline fun com.google.protobuf.kotlin.ExtensionList<*, "
       "$message$>.clear() {\n"
       "  clear(extension)\n"
       "}\n\n",

src/google/protobuf/compiler/java/primitive_field.cc

@@ -190,13 +190,6 @@ void SetPrimitiveVariables(const FieldDescriptor* descriptor,
   (*variables)["set_mutable_bit_builder"] = GenerateSetBit(builderBitIndex);
   (*variables)["clear_mutable_bit_builder"] = GenerateClearBit(builderBitIndex);
 
-  // For repeated fields, one bit is used for whether the array is immutable
-  // in the parsing constructor.
-  (*variables)["get_mutable_bit_parser"] =
-      GenerateGetBitMutableLocal(builderBitIndex);
-  (*variables)["set_mutable_bit_parser"] =
-      GenerateSetBitMutableLocal(builderBitIndex);
-
   (*variables)["get_has_field_bit_from_local"] =
       GenerateGetBitFromLocal(builderBitIndex);
   (*variables)["set_has_field_bit_to_local"] =
@@ -324,7 +317,7 @@ void ImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: $kt_type$\n"
+                 "$kt_deprecation$public var $kt_name$: $kt_type$\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -335,7 +328,7 @@ void ImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -344,7 +337,7 @@ void ImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
                                  /* builder */ false, /* kdoc */ true);
     printer->Print(
         variables_,
-        "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+        "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
         "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
         "}\n");
   }
@@ -405,16 +398,11 @@ void ImmutablePrimitiveFieldGenerator::GenerateBuildingCode(
   }
 }
 
-void ImmutablePrimitiveFieldGenerator::GenerateParsingCode(
+void ImmutablePrimitiveFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   printer->Print(variables_,
-                 "$set_has_field_bit_message$\n"
-                 "$name$_ = input.read$capitalized_type$();\n");
-}
-
-void ImmutablePrimitiveFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  // noop for primitives.
+                 "$name$_ = input.read$capitalized_type$();\n"
+                 "$set_has_field_bit_builder$\n");
 }
 
 void ImmutablePrimitiveFieldGenerator::GenerateSerializationCode(
@@ -619,6 +607,11 @@ void ImmutablePrimitiveOneofFieldGenerator::GenerateBuilderMembers(
   printer->Annotate("{", "}", descriptor_);
 }
 
+void ImmutablePrimitiveOneofFieldGenerator::GenerateBuilderClearCode(
+    io::Printer* printer) const {
+  // When a primitive field is in a oneof, clearing the oneof clears that field.
+}
+
 void ImmutablePrimitiveOneofFieldGenerator::GenerateBuildingCode(
     io::Printer* printer) const {
   printer->Print(variables_,
@@ -633,7 +626,7 @@ void ImmutablePrimitiveOneofFieldGenerator::GenerateMergingCode(
                  "set$capitalized_name$(other.get$capitalized_name$());\n");
 }
 
-void ImmutablePrimitiveOneofFieldGenerator::GenerateParsingCode(
+void ImmutablePrimitiveOneofFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   printer->Print(variables_,
                  "$oneof_name$_ = input.read$capitalized_type$();\n"
@@ -854,12 +847,12 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$ public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -872,7 +865,7 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: $kt_type$) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -884,7 +877,7 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: $kt_type$) {\n"
                  "  add(value)\n"
@@ -895,7 +888,7 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "addAll(values: kotlin.collections.Iterable<$kt_type$>) {\n"
                  "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -908,7 +901,7 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<$kt_type$>) {\n"
       "  addAll(values)\n"
@@ -920,7 +913,7 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: $kt_type$) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -931,7 +924,7 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
@@ -987,38 +980,24 @@ void RepeatedImmutablePrimitiveFieldGenerator::GenerateBuildingCode(
                  "result.$name$_ = $name$_;\n");
 }
 
-void RepeatedImmutablePrimitiveFieldGenerator::GenerateParsingCode(
+void RepeatedImmutablePrimitiveFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   printer->Print(variables_,
-                 "if (!$get_mutable_bit_parser$) {\n"
-                 "  $name$_ = $create_list$;\n"
-                 "  $set_mutable_bit_parser$;\n"
-                 "}\n"
-                 "$repeated_add$(input.read$capitalized_type$());\n");
+                 "$type$ v = input.read$capitalized_type$();\n"
+                 "ensure$capitalized_name$IsMutable();\n"
+                 "$repeated_add$(v);\n");
 }
 
-void RepeatedImmutablePrimitiveFieldGenerator::GenerateParsingCodeFromPacked(
-    io::Printer* printer) const {
-  printer->Print(
-      variables_,
-      "int length = input.readRawVarint32();\n"
-      "int limit = input.pushLimit(length);\n"
-      "if (!$get_mutable_bit_parser$ && input.getBytesUntilLimit() > 0) {\n"
-      "  $name$_ = $create_list$;\n"
-      "  $set_mutable_bit_parser$;\n"
-      "}\n"
-      "while (input.getBytesUntilLimit() > 0) {\n"
-      "  $repeated_add$(input.read$capitalized_type$());\n"
-      "}\n"
-      "input.popLimit(limit);\n");
-}
-
-void RepeatedImmutablePrimitiveFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
+void RepeatedImmutablePrimitiveFieldGenerator::
+    GenerateBuilderParsingCodeFromPacked(io::Printer* printer) const {
   printer->Print(variables_,
-                 "if ($get_mutable_bit_parser$) {\n"
-                 "  $name_make_immutable$; // C\n"
-                 "}\n");
+                 "int length = input.readRawVarint32();\n"
+                 "int limit = input.pushLimit(length);\n"
+                 "ensure$capitalized_name$IsMutable();\n"
+                 "while (input.getBytesUntilLimit() > 0) {\n"
+                 "  $repeated_add$(input.read$capitalized_type$());\n"
+                 "}\n"
+                 "input.popLimit(limit);\n");
 }
 
 void RepeatedImmutablePrimitiveFieldGenerator::GenerateSerializationCode(

src/google/protobuf/compiler/java/primitive_field.h

@@ -79,8 +79,7 @@ class ImmutablePrimitiveFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(
@@ -111,9 +110,10 @@ class ImmutablePrimitiveOneofFieldGenerator
 
   void GenerateMembers(io::Printer* printer) const override;
   void GenerateBuilderMembers(io::Printer* printer) const override;
+  void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
 };
@@ -140,9 +140,9 @@ class RepeatedImmutablePrimitiveFieldGenerator
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingCodeFromPacked(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCodeFromPacked(
+      io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(

src/google/protobuf/compiler/java/primitive_field_lite.cc

@@ -348,7 +348,7 @@ void ImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: $kt_type$\n"
+                 "$kt_deprecation$public var $kt_name$: $kt_type$\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -359,7 +359,7 @@ void ImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -368,7 +368,7 @@ void ImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
                                  /* builder */ false, /* kdoc */ true);
     printer->Print(
         variables_,
-        "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+        "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
         "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
         "}\n");
   }
@@ -699,12 +699,12 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   WriteFieldDocComment(printer, descriptor_);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$ public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -717,7 +717,7 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: $kt_type$) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -729,7 +729,7 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: $kt_type$) {\n"
                  "  add(value)\n"
@@ -740,7 +740,7 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "addAll(values: kotlin.collections.Iterable<$kt_type$>) {\n"
                  "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -753,7 +753,7 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<$kt_type$>) {\n"
       "  addAll(values)\n"
@@ -765,7 +765,7 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: $kt_type$) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -776,7 +776,7 @@ void RepeatedImmutablePrimitiveFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<$kt_type$, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/java/string_field.cc

@@ -132,13 +132,6 @@ void SetPrimitiveVariables(const FieldDescriptor* descriptor,
   (*variables)["set_mutable_bit_builder"] = GenerateSetBit(builderBitIndex);
   (*variables)["clear_mutable_bit_builder"] = GenerateClearBit(builderBitIndex);
 
-  // For repeated fields, one bit is used for whether the array is immutable
-  // in the parsing constructor.
-  (*variables)["get_mutable_bit_parser"] =
-      GenerateGetBitMutableLocal(builderBitIndex);
-  (*variables)["set_mutable_bit_parser"] =
-      GenerateSetBitMutableLocal(builderBitIndex);
-
   (*variables)["get_has_field_bit_from_local"] =
       GenerateGetBitFromLocal(builderBitIndex);
   (*variables)["set_has_field_bit_to_local"] =
@@ -383,7 +376,7 @@ void ImmutableStringFieldGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: kotlin.String\n"
+                 "$kt_deprecation$public var $kt_name$: kotlin.String\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -394,7 +387,7 @@ void ImmutableStringFieldGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -403,7 +396,7 @@ void ImmutableStringFieldGenerator::GenerateKotlinDslMembers(
                                  /* builder */ false, /* kdoc */ true);
     printer->Print(
         variables_,
-        "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+        "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
         "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
         "}\n");
   }
@@ -457,26 +450,19 @@ void ImmutableStringFieldGenerator::GenerateBuildingCode(
   printer->Print(variables_, "result.$name$_ = $name$_;\n");
 }
 
-void ImmutableStringFieldGenerator::GenerateParsingCode(
+void ImmutableStringFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   if (CheckUtf8(descriptor_)) {
     printer->Print(variables_,
-                   "java.lang.String s = input.readStringRequireUtf8();\n"
-                   "$set_has_field_bit_message$\n"
-                   "$name$_ = s;\n");
+                   "$name$_ = input.readStringRequireUtf8();\n"
+                   "$set_has_field_bit_builder$\n");
   } else {
     printer->Print(variables_,
-                   "com.google.protobuf.ByteString bs = input.readBytes();\n"
-                   "$set_has_field_bit_message$\n"
-                   "$name$_ = bs;\n");
+                   "$name$_ = input.readBytes();\n"
+                   "$set_has_field_bit_builder$\n");
   }
 }
 
-void ImmutableStringFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  // noop for strings.
-}
-
 void ImmutableStringFieldGenerator::GenerateSerializationCode(
     io::Printer* printer) const {
   printer->Print(variables_,
@@ -700,6 +686,11 @@ void ImmutableStringOneofFieldGenerator::GenerateBuilderMembers(
                  "}\n");
 }
 
+void ImmutableStringOneofFieldGenerator::GenerateBuilderClearCode(
+    io::Printer* printer) const {
+  // String fields in oneofs are correctly cleared by clearing the oneof
+}
+
 void ImmutableStringOneofFieldGenerator::GenerateMergingCode(
     io::Printer* printer) const {
   // Allow a slight breach of abstraction here in order to avoid forcing
@@ -718,7 +709,7 @@ void ImmutableStringOneofFieldGenerator::GenerateBuildingCode(
                  "}\n");
 }
 
-void ImmutableStringOneofFieldGenerator::GenerateParsingCode(
+void ImmutableStringOneofFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   if (CheckUtf8(descriptor_)) {
     printer->Print(variables_,
@@ -968,14 +959,14 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   // property for List<String>
   WriteFieldAccessorDocComment(printer, descriptor_, LIST_GETTER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$ val $kt_name$: "
+                 "$kt_deprecation$public val $kt_name$: "
                  "com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>\n"
                  "  @kotlin.jvm.JvmSynthetic\n"
@@ -989,7 +980,7 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: kotlin.String) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -1002,7 +993,7 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: kotlin.String) {\n"
                  "  add(value)\n"
@@ -1015,7 +1006,7 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslList"
+      "public fun com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
       "addAll(values: kotlin.collections.Iterable<kotlin.String>) {\n"
       "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -1029,7 +1020,7 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<kotlin.String>) {\n"
       "  addAll(values)\n"
@@ -1042,7 +1033,7 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: kotlin.String) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -1053,7 +1044,7 @@ void RepeatedImmutableStringFieldGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
@@ -1110,35 +1101,21 @@ void RepeatedImmutableStringFieldGenerator::GenerateBuildingCode(
                  "result.$name$_ = $name$_;\n");
 }
 
-void RepeatedImmutableStringFieldGenerator::GenerateParsingCode(
+void RepeatedImmutableStringFieldGenerator::GenerateBuilderParsingCode(
     io::Printer* printer) const {
   if (CheckUtf8(descriptor_)) {
     printer->Print(variables_,
-                   "java.lang.String s = input.readStringRequireUtf8();\n");
+                   "java.lang.String s = input.readStringRequireUtf8();\n"
+                   "ensure$capitalized_name$IsMutable();\n"
+                   "$name$_.add(s);\n");
   } else {
     printer->Print(variables_,
-                   "com.google.protobuf.ByteString bs = input.readBytes();\n");
-  }
-  printer->Print(variables_,
-                 "if (!$get_mutable_bit_parser$) {\n"
-                 "  $name$_ = new com.google.protobuf.LazyStringArrayList();\n"
-                 "  $set_mutable_bit_parser$;\n"
-                 "}\n");
-  if (CheckUtf8(descriptor_)) {
-    printer->Print(variables_, "$name$_.add(s);\n");
-  } else {
-    printer->Print(variables_, "$name$_.add(bs);\n");
+                   "com.google.protobuf.ByteString bs = input.readBytes();\n"
+                   "ensure$capitalized_name$IsMutable();\n"
+                   "$name$_.add(bs);\n");
   }
 }
 
-void RepeatedImmutableStringFieldGenerator::GenerateParsingDoneCode(
-    io::Printer* printer) const {
-  printer->Print(variables_,
-                 "if ($get_mutable_bit_parser$) {\n"
-                 "  $name$_ = $name$_.getUnmodifiableView();\n"
-                 "}\n");
-}
-
 void RepeatedImmutableStringFieldGenerator::GenerateSerializationCode(
     io::Printer* printer) const {
   printer->Print(variables_,

src/google/protobuf/compiler/java/string_field.h

@@ -78,8 +78,7 @@ class ImmutableStringFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(
@@ -111,9 +110,10 @@ class ImmutableStringOneofFieldGenerator
  private:
   void GenerateMembers(io::Printer* printer) const override;
   void GenerateBuilderMembers(io::Printer* printer) const override;
+  void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
 };
@@ -139,8 +139,7 @@ class RepeatedImmutableStringFieldGenerator : public ImmutableFieldGenerator {
   void GenerateBuilderClearCode(io::Printer* printer) const override;
   void GenerateMergingCode(io::Printer* printer) const override;
   void GenerateBuildingCode(io::Printer* printer) const override;
-  void GenerateParsingCode(io::Printer* printer) const override;
-  void GenerateParsingDoneCode(io::Printer* printer) const override;
+  void GenerateBuilderParsingCode(io::Printer* printer) const override;
   void GenerateSerializationCode(io::Printer* printer) const override;
   void GenerateSerializedSizeCode(io::Printer* printer) const override;
   void GenerateFieldBuilderInitializationCode(

src/google/protobuf/compiler/java/string_field_lite.cc

@@ -348,7 +348,7 @@ void ImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
     io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_, /* kdoc */ true);
   printer->Print(variables_,
-                 "$kt_deprecation$var $kt_name$: kotlin.String\n"
+                 "$kt_deprecation$public var $kt_name$: kotlin.String\n"
                  "  @JvmName(\"${$get$kt_capitalized_name$$}$\")\n"
                  "  get() = $kt_dsl_builder$.${$get$capitalized_name$$}$()\n"
                  "  @JvmName(\"${$set$kt_capitalized_name$$}$\")\n"
@@ -359,7 +359,7 @@ void ImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
   WriteFieldAccessorDocComment(printer, descriptor_, CLEARER,
                                /* builder */ false, /* kdoc */ true);
   printer->Print(variables_,
-                 "fun ${$clear$kt_capitalized_name$$}$() {\n"
+                 "public fun ${$clear$kt_capitalized_name$$}$() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"
                  "}\n");
 
@@ -368,7 +368,7 @@ void ImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
                                  /* builder */ false, /* kdoc */ true);
     printer->Print(
         variables_,
-        "fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
+        "public fun ${$has$kt_capitalized_name$$}$(): kotlin.Boolean {\n"
         "  return $kt_dsl_builder$.${$has$capitalized_name$$}$()\n"
         "}\n");
   }
@@ -798,7 +798,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
       " */\n"
       "@kotlin.OptIn"
       "(com.google.protobuf.kotlin.OnlyForUseByGeneratedProtoCode::class)\n"
-      "class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
+      "public class ${$$kt_capitalized_name$Proxy$}$ private constructor()"
       " : com.google.protobuf.kotlin.DslProxy()\n");
 
   // property for List<String>
@@ -806,7 +806,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
                                /* builder */ false, /* kdoc */ true);
   printer->Print(
       variables_,
-      "$kt_deprecation$ val $kt_name$: "
+      "$kt_deprecation$public val $kt_name$: "
       "com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>\n"
       "@kotlin.OptIn"
@@ -821,7 +821,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"add$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
                  "add(value: kotlin.String) {\n"
                  "  $kt_dsl_builder$.${$add$capitalized_name$$}$(value)\n"
@@ -834,7 +834,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"plusAssign$kt_capitalized_name$\")\n"
                  "@Suppress(\"NOTHING_TO_INLINE\")\n"
-                 "inline operator fun com.google.protobuf.kotlin.DslList"
+                 "public inline operator fun com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
                  "plusAssign(value: kotlin.String) {\n"
                  "  add(value)\n"
@@ -847,7 +847,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"addAll$kt_capitalized_name$\")\n"
-      "fun com.google.protobuf.kotlin.DslList"
+      "public fun com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
       "addAll(values: kotlin.collections.Iterable<kotlin.String>) {\n"
       "  $kt_dsl_builder$.${$addAll$capitalized_name$$}$(values)\n"
@@ -861,7 +861,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"plusAssignAll$kt_capitalized_name$\")\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun com.google.protobuf.kotlin.DslList"
+      "public inline operator fun com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
       "plusAssign(values: kotlin.collections.Iterable<kotlin.String>) {\n"
       "  addAll(values)\n"
@@ -874,7 +874,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
       variables_,
       "@kotlin.jvm.JvmSynthetic\n"
       "@kotlin.jvm.JvmName(\"set$kt_capitalized_name$\")\n"
-      "operator fun com.google.protobuf.kotlin.DslList"
+      "public operator fun com.google.protobuf.kotlin.DslList"
       "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
       "set(index: kotlin.Int, value: kotlin.String) {\n"
       "  $kt_dsl_builder$.${$set$capitalized_name$$}$(index, value)\n"
@@ -885,7 +885,7 @@ void RepeatedImmutableStringFieldLiteGenerator::GenerateKotlinDslMembers(
   printer->Print(variables_,
                  "@kotlin.jvm.JvmSynthetic\n"
                  "@kotlin.jvm.JvmName(\"clear$kt_capitalized_name$\")\n"
-                 "fun com.google.protobuf.kotlin.DslList"
+                 "public fun com.google.protobuf.kotlin.DslList"
                  "<kotlin.String, ${$$kt_capitalized_name$Proxy$}$>."
                  "clear() {\n"
                  "  $kt_dsl_builder$.${$clear$capitalized_name$$}$()\n"

src/google/protobuf/compiler/parser.cc

@@ -51,6 +51,7 @@
 #include "absl/strings/ascii.h"
 #include "absl/strings/escaping.h"
 #include "absl/strings/str_cat.h"
+#include "absl/strings/str_format.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/descriptor.pb.h"
 #include "google/protobuf/io/tokenizer.h"
@@ -288,6 +289,15 @@ bool Parser::ConsumeInteger64(uint64_t max_value, uint64_t* output,
   }
 }
 
+bool Parser::TryConsumeInteger64(uint64_t max_value, uint64_t* output) {
+  if (LookingAtType(io::Tokenizer::TYPE_INTEGER) &&
+      io::Tokenizer::ParseInteger(input_->current().text, max_value, output)) {
+    input_->Next();
+    return true;
+  }
+  return false;
+}
+
 bool Parser::ConsumeNumber(double* output, const char* error) {
   if (LookingAtType(io::Tokenizer::TYPE_FLOAT)) {
     *output = io::Tokenizer::ParseFloat(input_->current().text);
@@ -296,13 +306,19 @@ bool Parser::ConsumeNumber(double* output, const char* error) {
   } else if (LookingAtType(io::Tokenizer::TYPE_INTEGER)) {
     // Also accept integers.
     uint64_t value = 0;
-    if (!io::Tokenizer::ParseInteger(input_->current().text,
-                                     std::numeric_limits<uint64_t>::max(),
-                                     &value)) {
+    if (io::Tokenizer::ParseInteger(input_->current().text,
+                                    std::numeric_limits<uint64_t>::max(),
+                                    &value)) {
+      *output = value;
+    } else if (input_->current().text[0] == '0') {
+      // octal or hexadecimal; don't bother parsing as float
+      AddError("Integer out of range.");
+      // We still return true because we did, in fact, parse a number.
+    } else if (!io::Tokenizer::TryParseFloat(input_->current().text, output)) {
+      // out of int range, and not valid float? 🤷
       AddError("Integer out of range.");
       // We still return true because we did, in fact, parse a number.
     }
-    *output = value;
     input_->Next();
     return true;
   } else if (LookingAt("inf")) {
@@ -389,13 +405,16 @@ void Parser::AddError(const std::string& error) {
   AddError(input_->current().line, input_->current().column, error);
 }
 
-void Parser::AddWarning(const std::string& warning) {
+void Parser::AddWarning(int line, int column, const std::string& warning) {
   if (error_collector_ != nullptr) {
-    error_collector_->AddWarning(input_->current().line,
-                                 input_->current().column, warning);
+    error_collector_->AddWarning(line, column, warning);
   }
 }
 
+void Parser::AddWarning(const std::string& warning) {
+  AddWarning(input_->current().line, input_->current().column, warning);
+}
+
 // -------------------------------------------------------------------
 
 Parser::LocationRecorder::LocationRecorder(Parser* parser)
@@ -410,6 +429,11 @@ Parser::LocationRecorder::LocationRecorder(const LocationRecorder& parent) {
   Init(parent, parent.source_code_info_);
 }
 
+Parser::LocationRecorder::LocationRecorder(const LocationRecorder& parent,
+                                           SourceCodeInfo* source_code_info) {
+  Init(parent, source_code_info);
+}
+
 Parser::LocationRecorder::LocationRecorder(const LocationRecorder& parent,
                                            int path1,
                                            SourceCodeInfo* source_code_info) {
@@ -1239,13 +1263,22 @@ bool Parser::ParseDefaultAssignment(
     field->clear_default_value();
   }
 
+  LocationRecorder location(field_location,
+                            FieldDescriptorProto::kDefaultValueFieldNumber);
+
   DO(Consume("default"));
   DO(Consume("="));
 
-  LocationRecorder location(field_location,
-                            FieldDescriptorProto::kDefaultValueFieldNumber);
-  location.RecordLegacyLocation(field,
-                                DescriptorPool::ErrorCollector::DEFAULT_VALUE);
+  // We don't need to create separate spans in source code info for name and
+  // value, since there's no way to represent them distinctly in a location
+  // path. But we will want a separate recorder for the value, just to have more
+  // precise location info in error messages. So we let it create a location in
+  // no_op, so it doesn't add a span to the file descriptor.
+  SourceCodeInfo no_op;
+  LocationRecorder value_location(location, &no_op);
+  value_location.RecordLegacyLocation(
+      field, DescriptorPool::ErrorCollector::DEFAULT_VALUE);
+
   std::string* default_value = field->mutable_default_value();
 
   if (!field->has_type()) {
@@ -1316,18 +1349,19 @@ bool Parser::ParseDefaultAssignment(
     }
 
     case FieldDescriptorProto::TYPE_FLOAT:
-    case FieldDescriptorProto::TYPE_DOUBLE:
+    case FieldDescriptorProto::TYPE_DOUBLE: {
       // These types can be negative.
       if (TryConsume("-")) {
         default_value->append("-");
       }
       // Parse the integer because we have to convert hex integers to decimal
       // floats.
-      double value;
+      double value = 0;
       DO(ConsumeNumber(&value, "Expected number."));
       // And stringify it again.
       default_value->append(SimpleDtoa(value));
       break;
+    }
 
     case FieldDescriptorProto::TYPE_BOOL:
       if (TryConsume("true")) {
@@ -1379,13 +1413,23 @@ bool Parser::ParseJsonName(FieldDescriptorProto* field,
 
   LocationRecorder location(field_location,
                             FieldDescriptorProto::kJsonNameFieldNumber);
-  location.RecordLegacyLocation(field,
-                                DescriptorPool::ErrorCollector::OPTION_NAME);
 
-  DO(Consume("json_name"));
+  // We don't need to create separate spans in source code info for name and
+  // value, since there's no way to represent them distinctly in a location
+  // path. But we will want a separate recorder for them, just to have more
+  // precise location info in error messages. So we let them create a location
+  // in no_op, so they don't add a span to the file descriptor.
+  SourceCodeInfo no_op;
+  {
+    LocationRecorder name_location(location, &no_op);
+    name_location.RecordLegacyLocation(
+        field, DescriptorPool::ErrorCollector::OPTION_NAME);
+
+    DO(Consume("json_name"));
+  }
   DO(Consume("="));
 
-  LocationRecorder value_location(location);
+  LocationRecorder value_location(location, &no_op);
   value_location.RecordLegacyLocation(
       field, DescriptorPool::ErrorCollector::OPTION_VALUE);
 
@@ -1551,18 +1595,22 @@ bool Parser::ParseOption(Message* options,
             is_negative
                 ? static_cast<uint64_t>(std::numeric_limits<int64_t>::max()) + 1
                 : std::numeric_limits<uint64_t>::max();
-        DO(ConsumeInteger64(max_value, &value, "Expected integer."));
-        if (is_negative) {
-          value_location.AddPath(
-              UninterpretedOption::kNegativeIntValueFieldNumber);
-          uninterpreted_option->set_negative_int_value(
-              static_cast<int64_t>(0 - value));
-        } else {
-          value_location.AddPath(
-              UninterpretedOption::kPositiveIntValueFieldNumber);
-          uninterpreted_option->set_positive_int_value(value);
+        if (TryConsumeInteger64(max_value, &value)) {
+          if (is_negative) {
+            value_location.AddPath(
+                UninterpretedOption::kNegativeIntValueFieldNumber);
+            uninterpreted_option->set_negative_int_value(
+                static_cast<int64_t>(0 - value));
+          } else {
+            value_location.AddPath(
+                UninterpretedOption::kPositiveIntValueFieldNumber);
+            uninterpreted_option->set_positive_int_value(value);
+          }
+          break;
         }
-        break;
+        // value too large for an integer; fall through below to treat as
+        // floating point
+        ABSL_FALLTHROUGH_INTENDED;
       }
 
       case io::Tokenizer::TYPE_FLOAT: {
@@ -1728,11 +1776,25 @@ bool Parser::ParseReserved(DescriptorProto* message,
   }
 }
 
+bool Parser::ParseReservedName(std::string* name, const char* error_message) {
+  // Capture the position of the token, in case we have to report an
+  // error after it is consumed.
+  int line = input_->current().line;
+  int col = input_->current().column;
+  DO(ConsumeString(name, error_message));
+  if (!io::Tokenizer::IsIdentifier(*name)) {
+    AddWarning(line, col,
+               absl::StrFormat(
+                   "Reserved name \"%s\" is not a valid identifier.", *name));
+  }
+  return true;
+}
+
 bool Parser::ParseReservedNames(DescriptorProto* message,
                                 const LocationRecorder& parent_location) {
   do {
     LocationRecorder location(parent_location, message->reserved_name_size());
-    DO(ConsumeString(message->add_reserved_name(), "Expected field name."));
+    DO(ParseReservedName(message->add_reserved_name(), "Expected field name."));
   } while (TryConsume(","));
   DO(ConsumeEndOfDeclaration(";", &parent_location));
   return true;
@@ -1787,42 +1849,41 @@ bool Parser::ParseReservedNumbers(DescriptorProto* message,
   return true;
 }
 
-bool Parser::ParseReserved(EnumDescriptorProto* message,
-                           const LocationRecorder& message_location) {
+bool Parser::ParseReserved(EnumDescriptorProto* proto,
+                           const LocationRecorder& enum_location) {
   io::Tokenizer::Token start_token = input_->current();
   // Parse the declaration.
   DO(Consume("reserved"));
   if (LookingAtType(io::Tokenizer::TYPE_STRING)) {
-    LocationRecorder location(message_location,
+    LocationRecorder location(enum_location,
                               EnumDescriptorProto::kReservedNameFieldNumber);
     location.StartAt(start_token);
-    return ParseReservedNames(message, location);
+    return ParseReservedNames(proto, location);
   } else {
-    LocationRecorder location(message_location,
+    LocationRecorder location(enum_location,
                               EnumDescriptorProto::kReservedRangeFieldNumber);
     location.StartAt(start_token);
-    return ParseReservedNumbers(message, location);
+    return ParseReservedNumbers(proto, location);
   }
 }
 
-bool Parser::ParseReservedNames(EnumDescriptorProto* message,
+bool Parser::ParseReservedNames(EnumDescriptorProto* proto,
                                 const LocationRecorder& parent_location) {
   do {
-    LocationRecorder location(parent_location, message->reserved_name_size());
-    DO(ConsumeString(message->add_reserved_name(), "Expected enum value."));
+    LocationRecorder location(parent_location, proto->reserved_name_size());
+    DO(ParseReservedName(proto->add_reserved_name(), "Expected enum value."));
   } while (TryConsume(","));
   DO(ConsumeEndOfDeclaration(";", &parent_location));
   return true;
 }
 
-bool Parser::ParseReservedNumbers(EnumDescriptorProto* message,
+bool Parser::ParseReservedNumbers(EnumDescriptorProto* proto,
                                   const LocationRecorder& parent_location) {
   bool first = true;
   do {
-    LocationRecorder location(parent_location, message->reserved_range_size());
+    LocationRecorder location(parent_location, proto->reserved_range_size());
 
-    EnumDescriptorProto::EnumReservedRange* range =
-        message->add_reserved_range();
+    EnumDescriptorProto::EnumReservedRange* range = proto->add_reserved_range();
     int start, end;
     io::Tokenizer::Token start_token;
     {

src/google/protobuf/compiler/parser.h

@@ -180,6 +180,9 @@ class PROTOBUF_EXPORT Parser {
   // is greater than max_value, an error will be reported.
   bool ConsumeInteger64(uint64_t max_value, uint64_t* output,
                         const char* error);
+  // Try to consume a 64-bit integer and store its value in "output".  No
+  // error is reported on failure, allowing caller to consume token another way.
+  bool TryConsumeInteger64(uint64_t max_value, uint64_t* output);
   // Consume a number and store its value in "output".  This will accept
   // tokens of either INTEGER or FLOAT type.
   bool ConsumeNumber(double* output, const char* error);
@@ -213,6 +216,9 @@ class PROTOBUF_EXPORT Parser {
   // of the current token.
   void AddError(const std::string& error);
 
+  // Invokes error_collector_->AddWarning(), if error_collector_ is not NULL.
+  void AddWarning(int line, int column, const std::string& warning);
+
   // Invokes error_collector_->AddWarning() with the line and column number
   // of the current token.
   void AddWarning(const std::string& warning);
@@ -239,6 +245,10 @@ class PROTOBUF_EXPORT Parser {
     LocationRecorder(const LocationRecorder& parent, int path1, int path2);
 
     // Creates a recorder that generates locations into given source code info.
+    LocationRecorder(const LocationRecorder& parent,
+                     SourceCodeInfo* source_code_info);
+    // Creates a recorder that generates locations into given source code info
+    // and calls AddPath() one time.
     LocationRecorder(const LocationRecorder& parent, int path1,
                      SourceCodeInfo* source_code_info);
 
@@ -394,6 +404,7 @@ class PROTOBUF_EXPORT Parser {
                      const LocationRecorder& message_location);
   bool ParseReservedNames(DescriptorProto* message,
                           const LocationRecorder& parent_location);
+  bool ParseReservedName(std::string* name, const char* error_message);
   bool ParseReservedNumbers(DescriptorProto* message,
                             const LocationRecorder& parent_location);
   bool ParseReserved(EnumDescriptorProto* message,

src/google/protobuf/compiler/parser_unittest.cc

@@ -147,6 +147,16 @@ class ParserTest : public testing::Test {
     EXPECT_EQ(io::Tokenizer::TYPE_END, input_->current().type);
   }
 
+  // Parse the text and expect that the given warnings are reported.
+  void ExpectHasWarnings(const char* text, const char* expected_warnings) {
+    SetupParser(text);
+    FileDescriptorProto file;
+    ASSERT_TRUE(parser_->Parse(input_.get(), &file));
+    EXPECT_EQ(io::Tokenizer::TYPE_END, input_->current().type);
+    ASSERT_EQ("", error_collector_.text_);
+    EXPECT_EQ(expected_warnings, error_collector_.warning_);
+  }
+
   // Same as above but does not expect that the parser parses the complete
   // input.
   void ExpectHasEarlyExitErrors(const char* text, const char* expected_errors) {
@@ -592,6 +602,56 @@ TEST_F(ParseMessageTest, FieldOptions) {
       "}");
 }
 
+TEST_F(ParseMessageTest, FieldOptionsSupportLargeDecimalLiteral) {
+  // decimal integer literal > uint64 max
+  ExpectParsesTo(
+      "import \"google/protobuf/descriptor.proto\";\n"
+      "extend google.protobuf.FieldOptions {\n"
+      "  optional double f = 10101;\n"
+      "}\n"
+      "message TestMessage {\n"
+      "  optional double a = 1 [default = 18446744073709551616];\n"
+      "  optional double b = 2 [default = -18446744073709551616];\n"
+      "  optional double c = 3 [(f) = 18446744073709551616];\n"
+      "  optional double d = 4 [(f) = -18446744073709551616];\n"
+      "}\n",
+
+      "dependency: \"google/protobuf/descriptor.proto\""
+      "extension {"
+      "  name: \"f\" label: LABEL_OPTIONAL type: TYPE_DOUBLE number: 10101"
+      "  extendee: \"google.protobuf.FieldOptions\""
+      "}"
+      "message_type {"
+      "  name: \"TestMessage\""
+      "  field {"
+      "    name: \"a\" label: LABEL_OPTIONAL type: TYPE_DOUBLE number: 1"
+      "    default_value: \"1.8446744073709552e+19\""
+      "  }"
+      "  field {"
+      "    name: \"b\" label: LABEL_OPTIONAL type: TYPE_DOUBLE number: 2"
+      "    default_value: \"-1.8446744073709552e+19\""
+      "  }"
+      "  field {"
+      "    name: \"c\" label: LABEL_OPTIONAL type: TYPE_DOUBLE number: 3"
+      "    options{"
+      "      uninterpreted_option{"
+      "        name{ name_part: \"f\" is_extension: true }"
+      "        double_value: 1.8446744073709552e+19"
+      "      }"
+      "    }"
+      "  }"
+      "  field {"
+      "    name: \"d\" label: LABEL_OPTIONAL type: TYPE_DOUBLE number: 4"
+      "    options{"
+      "      uninterpreted_option{"
+      "        name{ name_part: \"f\" is_extension: true }"
+      "        double_value: -1.8446744073709552e+19"
+      "      }"
+      "    }"
+      "  }"
+      "}");
+}
+
 TEST_F(ParseMessageTest, Oneof) {
   ExpectParsesTo(
       "message TestMessage {\n"
@@ -1675,6 +1735,15 @@ TEST_F(ParseErrorTest, EnumReservedMissingQuotes) {
       "2:11: Expected enum value or number range.\n");
 }
 
+TEST_F(ParseErrorTest, EnumReservedInvalidIdentifier) {
+  ExpectHasWarnings(
+      "enum TestEnum {\n"
+      "  FOO = 1;\n"
+      "  reserved \"foo bar\";\n"
+      "}\n",
+      "2:11: Reserved name \"foo bar\" is not a valid identifier.\n");
+}
+
 // -------------------------------------------------------------------
 // Reserved field number errors
 
@@ -1702,6 +1771,14 @@ TEST_F(ParseErrorTest, ReservedMissingQuotes) {
       "1:11: Expected field name or number range.\n");
 }
 
+TEST_F(ParseErrorTest, ReservedInvalidIdentifier) {
+  ExpectHasWarnings(
+      "enum TestEnum {\n"
+      "  reserved \"foo bar\";\n"
+      "}\n",
+      "1:11: Reserved name \"foo bar\" is not a valid identifier.\n");
+}
+
 TEST_F(ParseErrorTest, ReservedNegativeNumber) {
   ExpectHasErrors(
       "message Foo {\n"
@@ -1891,6 +1968,22 @@ TEST_F(ParserValidationErrorTest, FieldDefaultValueError) {
       "2:32: Enum type \"Baz\" has no value named \"NO_SUCH_VALUE\".\n");
 }
 
+TEST_F(ParserValidationErrorTest, FieldDefaultIntegerOutOfRange) {
+  ExpectHasErrors(
+      "message Foo {\n"
+      "  optional double bar = 1 [default = 0x10000000000000000];\n"
+      "}\n",
+      "1:37: Integer out of range.\n");
+}
+
+TEST_F(ParserValidationErrorTest, FieldOptionOutOfRange) {
+  ExpectHasErrors(
+      "message Foo {\n"
+      "  optional double bar = 1 [foo = 0x10000000000000000];\n"
+      "}\n",
+      "1:33: Integer out of range.\n");
+}
+
 TEST_F(ParserValidationErrorTest, FileOptionNameError) {
   ExpectHasValidationErrors(
       "option foo = 5;",
@@ -1977,8 +2070,117 @@ TEST_F(ParserValidationErrorTest, Proto3JsonConflictError) {
       "  uint32 foo = 1;\n"
       "  uint32 Foo = 2;\n"
       "}\n",
-      "3:9: The JSON camel-case name of field \"Foo\" conflicts with field "
-      "\"foo\". This is not allowed in proto3.\n");
+      "3:9: The default JSON name of field \"Foo\" (\"Foo\") conflicts "
+      "with the default JSON name of field \"foo\" (\"foo\"). "
+      "This is not allowed in proto3.\n");
+}
+
+TEST_F(ParserValidationErrorTest, Proto2JsonConflictError) {
+  // conflicts with default JSON names are not errors in proto2
+  ExpectParsesTo(
+      R"pb(
+        syntax = "proto2"
+        ;
+      message TestMessage {
+        optional uint32 foo = 1;
+        optional uint32 Foo = 2;
+      }
+      )pb",
+      R"pb(
+        syntax: 'proto2'
+        message_type {
+          name: 'TestMessage'
+          field {
+            label: LABEL_OPTIONAL
+            type: TYPE_UINT32
+            name: 'foo'
+            number: 1
+          }
+          field {
+            label: LABEL_OPTIONAL
+            type: TYPE_UINT32
+            name: 'Foo'
+            number: 2
+          }
+        }
+      )pb");
+}
+
+TEST_F(ParserValidationErrorTest, Proto2CustomJsonConflictWithDefaultError) {
+  // conflicts with default JSON names are not errors in proto2
+  ExpectParsesTo(
+      R"pb(
+        syntax = 'proto2'
+        ;
+      message TestMessage {
+        optional uint32 foo = 1 [json_name='bar'];
+        optional uint32 bar = 2;
+      }
+      )pb",
+      R"pb(
+        syntax: 'proto2'
+        message_type {
+          name: 'TestMessage'
+          field {
+            label: LABEL_OPTIONAL
+            type: TYPE_UINT32
+            name: 'foo'
+            number: 1
+            json_name: 'bar'
+          }
+          field {
+            label: LABEL_OPTIONAL
+            type: TYPE_UINT32
+            name: 'bar'
+            number: 2
+          }
+        }
+      )pb");
+}
+
+// TODO(b/248626372) Re-enable these in google3.
+TEST_F(ParserValidationErrorTest, Proto3CustomJsonConflictWithDefaultError) {
+  ExpectHasValidationErrors(
+      R"pb(
+        syntax = 'proto3'
+        ;
+      message TestMessage {
+        uint32 foo = 1 [json_name='bar'];
+        uint32 bar = 2;
+      }
+      )pb",
+      "5:15: The default JSON name of field \"bar\" (\"bar\") conflicts "
+      "with the custom JSON name of field \"foo\". "
+      "This is not allowed in proto3.\n");
+}
+
+TEST_F(ParserValidationErrorTest, Proto3CustomJsonConflictError) {
+  ExpectHasValidationErrors(
+      R"pb(
+        syntax = 'proto3'
+        ;
+      message TestMessage {
+        uint32 foo = 1 [json_name='baz'];
+        uint32 bar = 2 [json_name='baz'];
+      }
+      )pb",
+      "5:15: The custom JSON name of field \"bar\" (\"baz\") conflicts "
+      "with the custom JSON name of field \"foo\".\n");
+}
+
+TEST_F(ParserValidationErrorTest, Proto2CustomJsonConflictError) {
+  ExpectHasValidationErrors(
+      R"pb(
+        syntax = 'proto2'
+        ;
+      message TestMessage {
+        optional uint32 foo = 1 [json_name='baz'];
+        optional uint32 bar = 2 [json_name='baz'];
+      }
+      )pb",
+      // fails in proto2 also: can't explicitly configure bad custom JSON names
+      "5:24: The custom JSON name of field \"bar\" (\"baz\") conflicts "
+      "with the custom JSON name of field \"foo\".\n");
 }
 
 TEST_F(ParserValidationErrorTest, EnumNameError) {
@@ -3415,18 +3617,19 @@ TEST_F(SourceInfoTest, FieldOptions) {
   EXPECT_TRUE(
       Parse("message Foo {"
             "  optional int32 bar = 1 "
-            "$a$[default=$b$123$c$,$d$opt1=123$e$,"
-            "$f$opt2='hi'$g$]$h$;"
+            "$a$[$b$default=123$c$, $d$opt1=123$e$, "
+            "$f$opt2='hi'$g$, $h$json_name='barBar'$i$]$j$;"
             "}\n"));
 
   const FieldDescriptorProto& field = file_.message_type(0).field(0);
   const UninterpretedOption& option1 = field.options().uninterpreted_option(0);
   const UninterpretedOption& option2 = field.options().uninterpreted_option(1);
 
-  EXPECT_TRUE(HasSpan('a', 'h', field.options()));
+  EXPECT_TRUE(HasSpan('a', 'j', field.options()));
   EXPECT_TRUE(HasSpan('b', 'c', field, "default_value"));
   EXPECT_TRUE(HasSpan('d', 'e', option1));
   EXPECT_TRUE(HasSpan('f', 'g', option2));
+  EXPECT_TRUE(HasSpan('h', 'i', field, "json_name"));
 
   // Ignore these.
   EXPECT_TRUE(HasSpan(file_));

src/google/protobuf/compiler/plugin.pb.h

@@ -15,7 +15,7 @@
 #error "your headers."
 #endif  // PROTOBUF_VERSION
 
-#if 3021005 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021006 < PROTOBUF_MIN_PROTOC_VERSION
 #error "This file was generated by an older version of protoc which is"
 #error "incompatible with your Protocol Buffer headers. Please"
 #error "regenerate this file with a newer version of protoc."

src/google/protobuf/descriptor.cc

@@ -3855,8 +3855,6 @@ class DescriptorBuilder {
                           internal::FlatAllocator& alloc);
   void BuildOneof(const OneofDescriptorProto& proto, Descriptor* parent,
                   OneofDescriptor* result, internal::FlatAllocator& alloc);
-  void CheckEnumValueUniqueness(const EnumDescriptorProto& proto,
-                                const EnumDescriptor* result);
   void BuildEnum(const EnumDescriptorProto& proto, const Descriptor* parent,
                  EnumDescriptor* result, internal::FlatAllocator& alloc);
   void BuildEnumValue(const EnumValueDescriptorProto& proto,
@@ -3868,6 +3866,15 @@ class DescriptorBuilder {
                    const ServiceDescriptor* parent, MethodDescriptor* result,
                    internal::FlatAllocator& alloc);
 
+  void CheckFieldJsonNameUniqueness(const DescriptorProto& proto,
+                                    const Descriptor* result);
+  void CheckFieldJsonNameUniqueness(const std::string& message_name,
+                                    const DescriptorProto& message,
+                                    FileDescriptor::Syntax syntax,
+                                    bool use_custom_names);
+  void CheckEnumValueUniqueness(const EnumDescriptorProto& proto,
+                                const EnumDescriptor* result);
+
   void LogUnusedDependency(const FileDescriptorProto& proto,
                            const FileDescriptor* result);
 
@@ -5423,7 +5430,11 @@ void DescriptorBuilder::BuildMessage(const DescriptorProto& proto,
     }
   }
 
+  // TODO(b/248626372) Make this consistent with OSS behavior.
+  CheckFieldJsonNameUniqueness(proto, result);
 
+  // Check that fields aren't using reserved names or numbers and that they
+  // aren't using extension numbers.
   for (int i = 0; i < result->field_count(); i++) {
     const FieldDescriptor* field = result->field(i);
     for (int j = 0; j < result->extension_range_count(); j++) {
@@ -5488,6 +5499,83 @@ void DescriptorBuilder::BuildMessage(const DescriptorProto& proto,
   }
 }
 
+void DescriptorBuilder::CheckFieldJsonNameUniqueness(
+    const DescriptorProto& proto, const Descriptor* result) {
+  FileDescriptor::Syntax syntax = result->file()->syntax();
+  std::string message_name = result->full_name();
+  // two passes: one looking only at default JSON names, and one that considers
+  // custom JSON names
+  CheckFieldJsonNameUniqueness(message_name, proto, syntax, false);
+  CheckFieldJsonNameUniqueness(message_name, proto, syntax, true);
+}
+
+namespace {
+// Helpers for function below
+
+struct JsonNameDetails {
+  const FieldDescriptorProto* field;
+  std::string orig_name;
+  bool is_custom;
+};
+
+JsonNameDetails GetJsonNameDetails(const FieldDescriptorProto* field,
+                                   bool use_custom) {
+  if (use_custom && field->has_json_name()) {
+    return {field, field->json_name(), true};
+  }
+  return {field, ToJsonName(field->name()), false};
+}
+
+}  // namespace
+
+void DescriptorBuilder::CheckFieldJsonNameUniqueness(
+    const std::string& message_name, const DescriptorProto& message,
+    FileDescriptor::Syntax syntax, bool use_custom_names) {
+  absl::flat_hash_map<std::string, JsonNameDetails> name_to_field;
+  for (const FieldDescriptorProto& field : message.field()) {
+    JsonNameDetails details = GetJsonNameDetails(&field, use_custom_names);
+    std::string lowercase_name = absl::AsciiStrToLower(details.orig_name);
+    auto existing = name_to_field.find(lowercase_name);
+    if (existing == name_to_field.end()) {
+      name_to_field[lowercase_name] = details;
+      continue;
+    }
+    JsonNameDetails& match = existing->second;
+    if (use_custom_names && !details.is_custom && !match.is_custom) {
+      // if this pass is considering custom JSON names, but neither of the
+      // names involved in the conflict are custom, don't bother with a
+      // message. That will have been reported from other pass (non-custom
+      // JSON names).
+      continue;
+    }
+    absl::string_view this_type = details.is_custom ? "custom" : "default";
+    absl::string_view existing_type = match.is_custom ? "custom" : "default";
+    // If the matched name differs (which it can only differ in case), include
+    // it in the error message, for maximum clarity to user.
+    std::string name_suffix;
+    if (details.orig_name != match.orig_name) {
+      name_suffix = absl::StrCat(" (\"", match.orig_name, "\")");
+    }
+    std::string error_message = absl::StrFormat(
+        "The %s JSON name of field \"%s\" (\"%s\") conflicts "
+        "with the %s JSON name of field \"%s\"%s.",
+        this_type, field.name(), details.orig_name, existing_type,
+        match.field->name(), name_suffix);
+
+    bool involves_default = !details.is_custom || !match.is_custom;
+    if (syntax == FileDescriptor::SYNTAX_PROTO2 && involves_default) {
+      AddWarning(message_name, field, DescriptorPool::ErrorCollector::NAME,
+                 error_message);
+    } else {
+      if (involves_default) {
+        absl::StrAppend(&error_message, " This is not allowed in proto3.");
+      }
+      AddError(message_name, field, DescriptorPool::ErrorCollector::NAME,
+               error_message);
+    }
+  }
+}
+
 void DescriptorBuilder::BuildFieldOrExtension(const FieldDescriptorProto& proto,
                                               Descriptor* parent,
                                               FieldDescriptor* result,
@@ -5891,13 +5979,12 @@ void DescriptorBuilder::CheckEnumValueUniqueness(
   //     NAME_TYPE_LAST_NAME = 2,
   //   }
   PrefixRemover remover(result->name());
-  std::map<std::string, const EnumValueDescriptor*> values;
+  absl::flat_hash_map<std::string, const EnumValueDescriptor*> values;
   for (int i = 0; i < result->value_count(); i++) {
     const EnumValueDescriptor* value = result->value(i);
     std::string stripped =
         EnumValueToPascalCase(remover.MaybeRemove(value->name()));
-    std::pair<std::map<std::string, const EnumValueDescriptor*>::iterator, bool>
-        insert_result = values.insert(std::make_pair(stripped, value));
+    auto insert_result = values.insert(std::make_pair(stripped, value));
     bool inserted = insert_result.second;
 
     // We don't throw the error if the two conflicting symbols are identical, or
@@ -5908,19 +5995,18 @@ void DescriptorBuilder::CheckEnumValueUniqueness(
     // stripping should de-dup the labels in this case).
     if (!inserted && insert_result.first->second->name() != value->name() &&
         insert_result.first->second->number() != value->number()) {
-      std::string error_message =
-          "Enum name " + value->name() + " has the same name as " +
-          values[stripped]->name() +
-          " if you ignore case and strip out the enum name prefix (if any). "
-          "This is error-prone and can lead to undefined behavior. "
-          "Please avoid doing this. If you are using allow_alias, please "
-          "assign the same numeric value to both enums.";
+      std::string error_message = absl::StrFormat(
+          "Enum name %s has the same name as %s if you ignore case and strip "
+          "out the enum name prefix (if any). (If you are using allow_alias, "
+          "please assign the same numeric value to both enums.)",
+          value->name(), values[stripped]->name());
       // There are proto2 enums out there with conflicting names, so to preserve
       // compatibility we issue only a warning for proto2.
       if (result->file()->syntax() == FileDescriptor::SYNTAX_PROTO2) {
         AddWarning(value->full_name(), proto.value(i),
                    DescriptorPool::ErrorCollector::NAME, error_message);
       } else {
+        absl::StrAppend(&error_message, " This is not allowed in proto3.");
         AddError(value->full_name(), proto.value(i),
                  DescriptorPool::ErrorCollector::NAME, error_message);
       }
@@ -6787,19 +6873,6 @@ void DescriptorBuilder::ValidateProto3(FileDescriptor* file,
   }
 }
 
-static std::string ToLowercaseWithoutUnderscores(const std::string& name) {
-  std::string result;
-  for (char character : name) {
-    if (character != '_') {
-      if (character >= 'A' && character <= 'Z') {
-        result.push_back(character - 'A' + 'a');
-      } else {
-        result.push_back(character);
-      }
-    }
-  }
-  return result;
-}
 
 void DescriptorBuilder::ValidateProto3Message(Descriptor* message,
                                               const DescriptorProto& proto) {
@@ -6826,24 +6899,6 @@ void DescriptorBuilder::ValidateProto3Message(Descriptor* message,
              "MessageSet is not supported in proto3.");
   }
 
-  // In proto3, we reject field names if they conflict in camelCase.
-  // Note that we currently enforce a stricter rule: Field names must be
-  // unique after being converted to lowercase with underscores removed.
-  std::map<std::string, const FieldDescriptor*> name_to_field;
-  for (int i = 0; i < message->field_count(); ++i) {
-    std::string lowercase_name =
-        ToLowercaseWithoutUnderscores(message->field(i)->name());
-    if (name_to_field.find(lowercase_name) != name_to_field.end()) {
-      AddError(message->full_name(), proto.field(i),
-               DescriptorPool::ErrorCollector::NAME,
-               "The JSON camel-case name of field \"" +
-                   message->field(i)->name() + "\" conflicts with field \"" +
-                   name_to_field[lowercase_name]->name() + "\". This is not " +
-                   "allowed in proto3.");
-    } else {
-      name_to_field[lowercase_name] = message->field(i);
-    }
-  }
 }
 
 void DescriptorBuilder::ValidateProto3Field(FieldDescriptor* field,
@@ -7683,6 +7738,28 @@ bool DescriptorBuilder::OptionInterpreter::ExamineIfOptionIsSet(
   return true;
 }
 
+namespace {
+// Helpers for method below
+
+template <typename T>
+std::string ValueOutOfRange(absl::string_view type_name,
+                            absl::string_view option_name) {
+  return absl::StrFormat("Value out of range, %d to %d, for %s option \"%s\".",
+                         std::numeric_limits<T>::min(),
+                         std::numeric_limits<T>::max(), type_name, option_name);
+}
+
+template <typename T>
+std::string ValueMustBeInt(absl::string_view type_name,
+                           absl::string_view option_name) {
+  return absl::StrFormat(
+      "Value must be integer, from %d to %d, for %s option \"%s\".",
+      std::numeric_limits<T>::min(), std::numeric_limits<T>::max(), type_name,
+      option_name);
+}
+
+}  // namespace
+
 bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
     const FieldDescriptor* option_field, UnknownFieldSet* unknown_fields) {
   // We switch on the CppType to validate.
@@ -7691,8 +7768,8 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
       if (uninterpreted_option_->has_positive_int_value()) {
         if (uninterpreted_option_->positive_int_value() >
             static_cast<uint64_t>(std::numeric_limits<int32_t>::max())) {
-          return AddValueError("Value out of range for int32 option \"" +
-                               option_field->full_name() + "\".");
+          return AddValueError(
+              ValueOutOfRange<int32_t>("int32", option_field->full_name()));
         } else {
           SetInt32(option_field->number(),
                    uninterpreted_option_->positive_int_value(),
@@ -7701,16 +7778,16 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
       } else if (uninterpreted_option_->has_negative_int_value()) {
         if (uninterpreted_option_->negative_int_value() <
             static_cast<int64_t>(std::numeric_limits<int32_t>::min())) {
-          return AddValueError("Value out of range for int32 option \"" +
-                               option_field->full_name() + "\".");
+          return AddValueError(
+              ValueOutOfRange<int32_t>("int32", option_field->full_name()));
         } else {
           SetInt32(option_field->number(),
                    uninterpreted_option_->negative_int_value(),
                    option_field->type(), unknown_fields);
         }
       } else {
-        return AddValueError("Value must be integer for int32 option \"" +
-                             option_field->full_name() + "\".");
+        return AddValueError(
+            ValueMustBeInt<int32_t>("int32", option_field->full_name()));
       }
       break;
 
@@ -7718,8 +7795,8 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
       if (uninterpreted_option_->has_positive_int_value()) {
         if (uninterpreted_option_->positive_int_value() >
             static_cast<uint64_t>(std::numeric_limits<int64_t>::max())) {
-          return AddValueError("Value out of range for int64 option \"" +
-                               option_field->full_name() + "\".");
+          return AddValueError(
+              ValueOutOfRange<int64_t>("int64", option_field->full_name()));
         } else {
           SetInt64(option_field->number(),
                    uninterpreted_option_->positive_int_value(),
@@ -7730,8 +7807,8 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
                  uninterpreted_option_->negative_int_value(),
                  option_field->type(), unknown_fields);
       } else {
-        return AddValueError("Value must be integer for int64 option \"" +
-                             option_field->full_name() + "\".");
+        return AddValueError(
+            ValueMustBeInt<int64_t>("int64", option_field->full_name()));
       }
       break;
 
@@ -7739,8 +7816,8 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
       if (uninterpreted_option_->has_positive_int_value()) {
         if (uninterpreted_option_->positive_int_value() >
             std::numeric_limits<uint32_t>::max()) {
-          return AddValueError("Value out of range for uint32 option \"" +
-                               option_field->name() + "\".");
+          return AddValueError(
+              ValueOutOfRange<uint32_t>("uint32", option_field->full_name()));
         } else {
           SetUInt32(option_field->number(),
                     uninterpreted_option_->positive_int_value(),
@@ -7748,9 +7825,7 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
         }
       } else {
         return AddValueError(
-            "Value must be non-negative integer for uint32 "
-            "option \"" +
-            option_field->full_name() + "\".");
+            ValueMustBeInt<uint32_t>("uint32", option_field->full_name()));
       }
       break;
 
@@ -7761,9 +7836,7 @@ bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
                   option_field->type(), unknown_fields);
       } else {
         return AddValueError(
-            "Value must be non-negative integer for uint64 "
-            "option \"" +
-            option_field->full_name() + "\".");
+            ValueMustBeInt<uint64_t>("uint64", option_field->full_name()));
       }
       break;
 

src/google/protobuf/descriptor.pb.h

@@ -15,7 +15,7 @@
 #error "your headers."
 #endif  // PROTOBUF_VERSION
 
-#if 3021005 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021006 < PROTOBUF_MIN_PROTOC_VERSION
 #error "This file was generated by an older version of protoc which is"
 #error "incompatible with your Protocol Buffer headers. Please"
 #error "regenerate this file with a newer version of protoc."

src/google/protobuf/descriptor_unittest.cc

@@ -5624,7 +5624,8 @@ TEST_F(ValidationErrorTest, Int32OptionValueOutOfPositiveRange) {
       "                                 positive_int_value: 0x80000000 } "
       "}",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value out of range "
+      "foo.proto: foo.proto: OPTION_VALUE: Value out of range, -2147483648 to "
+      "2147483647, "
       "for int32 option \"foo\".\n");
 }
 
@@ -5641,7 +5642,8 @@ TEST_F(ValidationErrorTest, Int32OptionValueOutOfNegativeRange) {
       "                                 negative_int_value: -0x80000001 } "
       "}",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value out of range "
+      "foo.proto: foo.proto: OPTION_VALUE: Value out of range, -2147483648 to "
+      "2147483647, "
       "for int32 option \"foo\".\n");
 }
 
@@ -5657,7 +5659,8 @@ TEST_F(ValidationErrorTest, Int32OptionValueIsNotPositiveInt) {
       "                                        is_extension: true } "
       "                                 string_value: \"5\" } }",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value must be integer "
+      "foo.proto: foo.proto: OPTION_VALUE: Value must be integer, from "
+      "-2147483648 to 2147483647, "
       "for int32 option \"foo\".\n");
 }
 
@@ -5675,7 +5678,8 @@ TEST_F(ValidationErrorTest, Int64OptionValueOutOfRange) {
       "} "
       "}",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value out of range "
+      "foo.proto: foo.proto: OPTION_VALUE: Value out of range, "
+      "-9223372036854775808 to 9223372036854775807, "
       "for int64 option \"foo\".\n");
 }
 
@@ -5691,7 +5695,8 @@ TEST_F(ValidationErrorTest, Int64OptionValueIsNotPositiveInt) {
       "                                        is_extension: true } "
       "                                 identifier_value: \"5\" } }",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value must be integer "
+      "foo.proto: foo.proto: OPTION_VALUE: Value must be integer, from "
+      "-9223372036854775808 to 9223372036854775807, "
       "for int64 option \"foo\".\n");
 }
 
@@ -5707,7 +5712,8 @@ TEST_F(ValidationErrorTest, UInt32OptionValueOutOfRange) {
       "                                        is_extension: true } "
       "                                 positive_int_value: 0x100000000 } }",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value out of range "
+      "foo.proto: foo.proto: OPTION_VALUE: Value out of range, 0 to "
+      "4294967295, "
       "for uint32 option \"foo\".\n");
 }
 
@@ -5723,7 +5729,8 @@ TEST_F(ValidationErrorTest, UInt32OptionValueIsNotPositiveInt) {
       "                                        is_extension: true } "
       "                                 double_value: -5.6 } }",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value must be non-negative integer "
+      "foo.proto: foo.proto: OPTION_VALUE: Value must be integer, from 0 to "
+      "4294967295, "
       "for uint32 option \"foo\".\n");
 }
 
@@ -5739,7 +5746,8 @@ TEST_F(ValidationErrorTest, UInt64OptionValueIsNotPositiveInt) {
       "                                        is_extension: true } "
       "                                 negative_int_value: -5 } }",
 
-      "foo.proto: foo.proto: OPTION_VALUE: Value must be non-negative integer "
+      "foo.proto: foo.proto: OPTION_VALUE: Value must be integer, from 0 to "
+      "18446744073709551615, "
       "for uint64 option \"foo\".\n");
 }
 
@@ -6478,9 +6486,10 @@ TEST_F(ValidationErrorTest, EnumValuesConflictWithDifferentCasing) {
       "}",
       "foo.proto: bar: NAME: Enum name bar has the same name as BAR "
       "if you ignore case and strip out the enum name prefix (if any). "
-      "This is error-prone and can lead to undefined behavior. "
-      "Please avoid doing this. If you are using allow_alias, please assign "
-      "the same numeric value to both enums.\n");
+      "(If you are using allow_alias, please assign the same numeric "
+      "value to both enums.)"
+      " This is not allowed in proto3.\n"
+  );
 
   // Not an error because both enums are mapped to the same value.
   BuildFile(
@@ -6496,6 +6505,20 @@ TEST_F(ValidationErrorTest, EnumValuesConflictWithDifferentCasing) {
 }
 
 TEST_F(ValidationErrorTest, EnumValuesConflictWhenPrefixesStripped) {
+  BuildFileWithErrors(
+      "syntax: 'proto3'"
+      "name: 'foo.proto' "
+      "enum_type {"
+      "  name: 'FooEnum' "
+      "  value { name: 'BAR' number: 0 }"
+      "  value { name: 'bar' number: 1 }"
+      "}",
+      "foo.proto: bar: NAME: Enum name bar has the same name as BAR "
+      "if you ignore case and strip out the enum name prefix (if any). "
+      "(If you are using allow_alias, please assign the same numeric "
+      "value to both enums.)"
+      " This is not allowed in proto3.\n"
+  );
   BuildFileWithErrors(
       "syntax: 'proto3'"
       "name: 'foo.proto' "
@@ -6506,9 +6529,10 @@ TEST_F(ValidationErrorTest, EnumValuesConflictWhenPrefixesStripped) {
       "}",
       "foo.proto: BAZ: NAME: Enum name BAZ has the same name as FOO_ENUM_BAZ "
       "if you ignore case and strip out the enum name prefix (if any). "
-      "This is error-prone and can lead to undefined behavior. "
-      "Please avoid doing this. If you are using allow_alias, please assign "
-      "the same numeric value to both enums.\n");
+      "(If you are using allow_alias, please assign the same numeric value "
+      "to both enums.)"
+      " This is not allowed in proto3.\n"
+  );
 
   BuildFileWithErrors(
       "syntax: 'proto3'"
@@ -6520,9 +6544,10 @@ TEST_F(ValidationErrorTest, EnumValuesConflictWhenPrefixesStripped) {
       "}",
       "foo.proto: BAZ: NAME: Enum name BAZ has the same name as FOOENUM_BAZ "
       "if you ignore case and strip out the enum name prefix (if any). "
-      "This is error-prone and can lead to undefined behavior. "
-      "Please avoid doing this. If you are using allow_alias, please assign "
-      "the same numeric value to both enums.\n");
+      "(If you are using allow_alias, please assign the same numeric value "
+      "to both enums.)"
+      " This is not allowed in proto3.\n"
+  );
 
   BuildFileWithErrors(
       "syntax: 'proto3'"
@@ -6534,9 +6559,10 @@ TEST_F(ValidationErrorTest, EnumValuesConflictWhenPrefixesStripped) {
       "}",
       "foo.proto: BAR__BAZ: NAME: Enum name BAR__BAZ has the same name as "
       "FOO_ENUM_BAR_BAZ if you ignore case and strip out the enum name prefix "
-      "(if any). This is error-prone and can lead to undefined behavior. "
-      "Please avoid doing this. If you are using allow_alias, please assign "
-      "the same numeric value to both enums.\n");
+      "(if any). (If you are using allow_alias, please assign the same numeric "
+      "value to both enums.)"
+      " This is not allowed in proto3.\n"
+  );
 
   BuildFileWithErrors(
       "syntax: 'proto3'"
@@ -6548,9 +6574,10 @@ TEST_F(ValidationErrorTest, EnumValuesConflictWhenPrefixesStripped) {
       "}",
       "foo.proto: BAR_BAZ: NAME: Enum name BAR_BAZ has the same name as "
       "FOO_ENUM__BAR_BAZ if you ignore case and strip out the enum name prefix "
-      "(if any). This is error-prone and can lead to undefined behavior. "
-      "Please avoid doing this. If you are using allow_alias, please assign "
-      "the same numeric value to both enums.\n");
+      "(if any). (If you are using allow_alias, please assign the same numeric "
+      "value to both enums.)"
+      " This is not allowed in proto3.\n"
+  );
 
   // This isn't an error because the underscore will cause the PascalCase to
   // differ by case (BarBaz vs. Barbaz).
@@ -6886,6 +6913,7 @@ TEST_F(ValidationErrorTest, ValidateProto3Extension) {
 
 // Test that field names that may conflict in JSON is not allowed by protoc.
 TEST_F(ValidationErrorTest, ValidateProto3JsonName) {
+  // TODO(b/248626372) Re-enable this once they're errors in google3.
   // The comparison is case-insensitive.
   BuildFileWithErrors(
       "name: 'foo.proto' "
@@ -6895,8 +6923,11 @@ TEST_F(ValidationErrorTest, ValidateProto3JsonName) {
       "  field { name:'name' number:1 label:LABEL_OPTIONAL type:TYPE_INT32 }"
       "  field { name:'Name' number:2 label:LABEL_OPTIONAL type:TYPE_INT32 }"
       "}",
-      "foo.proto: Foo: NAME: The JSON camel-case name of field \"Name\" "
-      "conflicts with field \"name\". This is not allowed in proto3.\n");
+      "foo.proto: Foo: NAME: The default JSON name of field \"Name\" "
+      "(\"Name\") "
+      "conflicts with the default JSON name of field \"name\" (\"name\"). This "
+      "is "
+      "not allowed in proto3.\n");
   // Underscores are ignored.
   BuildFileWithErrors(
       "name: 'foo.proto' "
@@ -6906,8 +6937,11 @@ TEST_F(ValidationErrorTest, ValidateProto3JsonName) {
       "  field { name:'ab' number:1 label:LABEL_OPTIONAL type:TYPE_INT32 }"
       "  field { name:'_a__b_' number:2 label:LABEL_OPTIONAL type:TYPE_INT32 }"
       "}",
-      "foo.proto: Foo: NAME: The JSON camel-case name of field \"_a__b_\" "
-      "conflicts with field \"ab\". This is not allowed in proto3.\n");
+      "foo.proto: Foo: NAME: The default JSON name of field \"_a__b_\" "
+      "(\"AB\") "
+      "conflicts with the default JSON name of field \"ab\" (\"ab\"). This is "
+      "not "
+      "allowed in proto3.\n");
 }
 
 

src/google/protobuf/io/tokenizer.cc

@@ -1002,9 +1002,20 @@ bool Tokenizer::ParseInteger(const std::string& text, uint64_t max_value,
 }
 
 double Tokenizer::ParseFloat(const std::string& text) {
+  double result = 0;
+  if (!TryParseFloat(text, &result)) {
+    GOOGLE_LOG(DFATAL)
+        << " Tokenizer::ParseFloat() passed text that could not have been"
+           " tokenized as a float: "
+        << absl::CEscape(text);
+  }
+  return result;
+}
+
+bool Tokenizer::TryParseFloat(const std::string& text, double* result) {
   const char* start = text.c_str();
   char* end;
-  double result = NoLocaleStrtod(start, &end);
+  *result = NoLocaleStrtod(start, &end);
 
   // "1e" is not a valid float, but if the tokenizer reads it, it will
   // report an error but still return it as a valid token.  We need to
@@ -1020,12 +1031,7 @@ double Tokenizer::ParseFloat(const std::string& text) {
     ++end;
   }
 
-  GOOGLE_LOG_IF(DFATAL,
-         static_cast<size_t>(end - start) != text.size() || *start == '-')
-      << " Tokenizer::ParseFloat() passed text that could not have been"
-         " tokenized as a float: "
-      << absl::CEscape(text);
-  return result;
+  return static_cast<size_t>(end - start) == text.size() && *start != '-';
 }
 
 // Helper to append a Unicode code point to a string as UTF8, without bringing

src/google/protobuf/io/tokenizer.h

@@ -214,6 +214,10 @@ class PROTOBUF_EXPORT Tokenizer {
   // result is undefined (possibly an assert failure).
   static double ParseFloat(const std::string& text);
 
+  // Parses given text as if it were a TYPE_FLOAT token.  Returns false if the
+  // given text is not actually a valid float literal.
+  static bool TryParseFloat(const std::string& text, double* result);
+
   // Parses a TYPE_STRING token.  This never fails, so long as the text actually
   // comes from a TYPE_STRING token parsed by Tokenizer.  If it doesn't, the
   // result is undefined (possibly an assert failure).

src/google/protobuf/io/zero_copy_stream_unittest.cc

@@ -720,6 +720,9 @@ TEST_F(IoTest, StringIo) {
 
 // Verifies that outputs up to kint32max can be created.
 TEST_F(IoTest, LargeOutput) {
+  // Filter out this test on 32-bit architectures.
+  if (sizeof(void*) < 8) return;
+
   std::string str;
   StringOutputStream output(&str);
   void* unused_data;

src/google/protobuf/port_def.inc

@@ -221,7 +221,7 @@
 #ifdef PROTOBUF_VERSION
 #error PROTOBUF_VERSION was previously defined
 #endif
-#define PROTOBUF_VERSION 3021005
+#define PROTOBUF_VERSION 3021006
 
 #ifdef PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC
 #error PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC was previously defined

src/google/protobuf/repeated_field_unittest.cc

@@ -429,14 +429,14 @@ TEST(RepeatedField, ReserveNothing) {
 
 TEST(RepeatedField, ReserveLowerClamp) {
   int clamped_value = internal::CalculateReserveSize<bool, sizeof(void*)>(0, 1);
-  EXPECT_GE(clamped_value, 8 / sizeof(bool));
+  EXPECT_GE(clamped_value, sizeof(void*) / sizeof(bool));
   EXPECT_EQ((internal::RepeatedFieldLowerClampLimit<bool, sizeof(void*)>()),
             clamped_value);
   // EXPECT_EQ(clamped_value, (internal::CalculateReserveSize<bool,
   // sizeof(void*)>( clamped_value, 2)));
 
   clamped_value = internal::CalculateReserveSize<int, sizeof(void*)>(0, 1);
-  EXPECT_GE(clamped_value, 8 / sizeof(int));
+  EXPECT_GE(clamped_value, sizeof(void*) / sizeof(int));
   EXPECT_EQ((internal::RepeatedFieldLowerClampLimit<int, sizeof(void*)>()),
             clamped_value);
   // EXPECT_EQ(clamped_value, (internal::CalculateReserveSize<int,

src/google/protobuf/stubs/common.h

@@ -81,7 +81,7 @@ namespace internal {
 
 // The current version, represented as a single integer to make comparison
 // easier:  major * 10^6 + minor * 10^3 + micro
-#define GOOGLE_PROTOBUF_VERSION 3021005
+#define GOOGLE_PROTOBUF_VERSION 3021006
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
 #define GOOGLE_PROTOBUF_VERSION_SUFFIX ""

src/google/protobuf/util/time_util_test.cc

@@ -48,15 +48,18 @@ using google::protobuf::Timestamp;
 namespace {
 
 TEST(TimeUtilTest, TimestampStringFormat) {
-  Timestamp begin, end;
-  EXPECT_TRUE(TimeUtil::FromString("0001-01-01T00:00:00Z", &begin));
-  EXPECT_EQ(TimeUtil::kTimestampMinSeconds, begin.seconds());
-  EXPECT_EQ(0, begin.nanos());
-  EXPECT_TRUE(TimeUtil::FromString("9999-12-31T23:59:59.999999999Z", &end));
-  EXPECT_EQ(TimeUtil::kTimestampMaxSeconds, end.seconds());
-  EXPECT_EQ(999999999, end.nanos());
-  EXPECT_EQ("0001-01-01T00:00:00Z", TimeUtil::ToString(begin));
-  EXPECT_EQ("9999-12-31T23:59:59.999999999Z", TimeUtil::ToString(end));
+  // These these are out of bounds for 32-bit architectures.
+  if (sizeof(time_t) >= sizeof(uint64_t)) {
+    Timestamp begin, end;
+    EXPECT_TRUE(TimeUtil::FromString("0001-01-01T00:00:00Z", &begin));
+    EXPECT_EQ(TimeUtil::kTimestampMinSeconds, begin.seconds());
+    EXPECT_EQ(0, begin.nanos());
+    EXPECT_TRUE(TimeUtil::FromString("9999-12-31T23:59:59.999999999Z", &end));
+    EXPECT_EQ(TimeUtil::kTimestampMaxSeconds, end.seconds());
+    EXPECT_EQ(999999999, end.nanos());
+    EXPECT_EQ("0001-01-01T00:00:00Z", TimeUtil::ToString(begin));
+    EXPECT_EQ("9999-12-31T23:59:59.999999999Z", TimeUtil::ToString(end));
+  }
 
   // Test negative timestamps.
   Timestamp time = TimeUtil::NanosecondsToTimestamp(-1);
@@ -94,9 +97,12 @@ TEST(TimeUtilTest, DurationStringFormat) {
   EXPECT_TRUE(TimeUtil::FromString("0001-01-01T00:00:00Z", &begin));
   EXPECT_TRUE(TimeUtil::FromString("9999-12-31T23:59:59.999999999Z", &end));
 
-  EXPECT_EQ("315537897599.999999999s", TimeUtil::ToString(end - begin));
+  // These these are out of bounds for 32-bit architectures.
+  if (sizeof(time_t) >= sizeof(uint64_t)) {
+    EXPECT_EQ("315537897599.999999999s", TimeUtil::ToString(end - begin));
+    EXPECT_EQ("-315537897599.999999999s", TimeUtil::ToString(begin - end));
+  }
   EXPECT_EQ(999999999, (end - begin).nanos());
-  EXPECT_EQ("-315537897599.999999999s", TimeUtil::ToString(begin - end));
   EXPECT_EQ(-999999999, (begin - end).nanos());
 
   // Generated output should contain 3, 6, or 9 fractional digits.