Merge tag 'refs/tags/sync-piper' into sync-stage

# Conflicts:
#	build_defs/cpp_opts.bzl

.bazelrc

@@ -1,35 +1 @@
 build --cxxopt=-std=c++14 --host_cxxopt=-std=c++14
-
-build:dbg --compilation_mode=dbg
-
-build:opt --compilation_mode=opt
-
-build:san-common --config=dbg --strip=never --copt=-O0 --copt=-fno-omit-frame-pointer
-
-build:asan --config=san-common --copt=-fsanitize=address --linkopt=-fsanitize=address
-build:asan --copt=-DADDRESS_SANITIZER=1
-# ASAN hits ODR violations with shared linkage due to rules_proto.
-build:asan --dynamic_mode=off
-
-build:msan --config=san-common --copt=-fsanitize=memory --linkopt=-fsanitize=memory
-build:msan --copt=-fsanitize-memory-track-origins
-build:msan --copt=-fsanitize-memory-use-after-dtor
-build:msan --action_env=MSAN_OPTIONS=poison_in_dtor=1
-build:msan --copt=-DMEMORY_SANITIZER=1
-
-# Use our instrumented LLVM libc++ in Kokoro.
-build:kokoro-msan --config=msan
-build:kokoro-msan --linkopt=-L/opt/libcxx_msan/lib
-build:kokoro-msan --linkopt=-Wl,-rpath,/opt/libcxx_msan/lib
-build:kokoro-msan --cxxopt=-stdlib=libc++ --linkopt=-stdlib=libc++
-
-
-build:tsan --config=san-common --copt=-fsanitize=thread --linkopt=-fsanitize=thread
-build:tsan --copt=-DTHREAD_SANITIZER=1
-
-build:ubsan --config=san-common --copt=-fsanitize=undefined --linkopt=-fsanitize=undefined
-build:ubsan --action_env=UBSAN_OPTIONS=halt_on_error=1:print_stacktrace=1
-build:ubsan --copt=-DUNDEFINED_SANITIZER=1
-# Workaround for the fact that Bazel links with $CC, not $CXX
-# https://github.com/bazelbuild/bazel/issues/11122#issuecomment-613746748
-build:ubsan --copt=-fno-sanitize=function --copt=-fno-sanitize=vptr

CMakeLists.txt

@@ -330,6 +330,7 @@ set_property(CACHE protobuf_ABSL_PROVIDER PROPERTY STRINGS "module" "package")
 include(${protobuf_SOURCE_DIR}/cmake/abseil-cpp.cmake)
 
 if (protobuf_BUILD_PROTOBUF_BINARIES)
+  include(${protobuf_SOURCE_DIR}/cmake/utf8_range.cmake)
   include(${protobuf_SOURCE_DIR}/cmake/libprotobuf-lite.cmake)
   if (NOT DEFINED protobuf_LIB_PROTOBUF_LITE)
     set(protobuf_LIB_PROTOBUF_LITE libprotobuf-lite)

build_defs/cpp_opts.bzl

@@ -22,6 +22,7 @@ COPTS = select({
         "-Werror",
     ],
 })
+
 # Android and MSVC builds do not need to link in a separate pthread library.
 LINK_OPTS = select({
     "//build_defs:config_android": [],

cmake/libprotobuf-lite.cmake

@@ -34,3 +34,6 @@ set_target_properties(libprotobuf-lite PROPERTIES
     OUTPUT_NAME ${LIB_PREFIX}protobuf-lite
     DEBUG_POSTFIX "${protobuf_DEBUG_POSTFIX}")
 add_library(protobuf::libprotobuf-lite ALIAS libprotobuf-lite)
+
+target_include_directories(libprotobuf-lite PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range)
+target_link_libraries(libprotobuf-lite PRIVATE utf8_validity)

cmake/libprotobuf.cmake

@@ -37,3 +37,6 @@ set_target_properties(libprotobuf PROPERTIES
     OUTPUT_NAME ${LIB_PREFIX}protobuf
     DEBUG_POSTFIX "${protobuf_DEBUG_POSTFIX}")
 add_library(protobuf::libprotobuf ALIAS libprotobuf)
+
+target_include_directories(libprotobuf PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range)
+target_link_libraries(libprotobuf PRIVATE utf8_validity)

cmake/utf8_range.cmake

@@ -0,0 +1,12 @@
+set(utf8_range_ENABLE_TESTS OFF)
+
+if (NOT EXISTS "${protobuf_SOURCE_DIR}/third_party/utf8_range/CMakeLists.txt")
+  message(FATAL_ERROR
+          "Cannot find third_party/utf8_range directory that's needed to "
+          "build conformance tests. If you use git, make sure you have cloned "
+          "submodules:\n"
+          "  git submodule update --init --recursive\n")
+endif()
+
+set(utf8_range_ENABLE_INSTALL ${protobuf_INSTALL})
+add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range third_party/utf8_range)

conformance/BUILD.bazel

@@ -5,7 +5,6 @@ load("//:protobuf.bzl", "internal_csharp_proto_library", "internal_objc_proto_li
 load("//build_defs:internal_shell.bzl", "inline_sh_binary")
 load(
     "@rules_pkg//:mappings.bzl",
-    "pkg_attributes",
     "pkg_filegroup",
     "pkg_files",
     "strip_prefix",
@@ -149,10 +148,10 @@ cc_library(
     hdrs = ["binary_json_conformance_suite.h"],
     deps = [
         ":conformance_test",
-        "@jsoncpp//:jsoncpp",
         ":test_messages_proto2_proto_cc",
         ":test_messages_proto3_proto_cc",
         "@com_google_absl//absl/status",
+        "@jsoncpp",
     ],
 )
 

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

@@ -202,6 +202,9 @@ public class SingleFieldBuilder<
       builder = null;
     }
     onChanged();
+    // After clearing, parent is dirty, but this field builder is now clean and any changes should
+    // trickle up.
+    isClean = true;
     return this;
   }
 

java/core/src/main/java/com/google/protobuf/SingleFieldBuilderV3.java

@@ -202,6 +202,9 @@ public class SingleFieldBuilderV3<
       builder = null;
     }
     onChanged();
+    // After clearing, parent is dirty, but this field builder is now clean and any changes should
+    // trickle up.
+    isClean = true;
     return this;
   }
 

java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java

@@ -33,6 +33,7 @@ package com.google.protobuf;
 import static com.google.common.truth.Truth.assertThat;
 
 import protobuf_unittest.Engine;
+import protobuf_unittest.TimingBelt;
 import protobuf_unittest.Vehicle;
 import protobuf_unittest.Wheel;
 import java.util.ArrayList;
@@ -48,6 +49,27 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class NestedBuildersTest {
 
+  @Test
+  public void test3LayerPropagationWithIntermediateClear() {
+    Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();
+    vehicleBuilder.getEngineBuilder().getTimingBeltBuilder();
+
+    // This step detaches the TimingBelt.Builder (though it leaves a SingleFieldBuilder in place)
+    vehicleBuilder.getEngineBuilder().clear();
+
+    // These steps build the middle and top level messages, it used to leave the vestigial
+    // TimingBelt.Builder in a state where further changes didn't propagate anymore
+    Object unused = vehicleBuilder.getEngineBuilder().build();
+    unused = vehicleBuilder.build();
+
+    TimingBelt expected = TimingBelt.newBuilder().setNumberOfTeeth(124).build();
+    vehicleBuilder.getEngineBuilder().setTimingBelt(expected);
+    // Testing that b/254158939 is fixed. It used to be that the setTimingBelt call above didn't
+    // propagate a change notification and the call below would return a stale version of the timing
+    // belt.
+    assertThat(vehicleBuilder.getEngine().getTimingBelt()).isEqualTo(expected);
+  }
+
   @Test
   public void testMessagesAndBuilders() {
     Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();

java/core/src/test/proto/com/google/protobuf/map_for_proto2_lite_test.proto

@@ -30,8 +30,8 @@
 
 syntax = "proto2";
 
-
 package map_for_proto2_lite_test;
+
 option java_outer_classname = "MapForProto2TestProto";
 option optimize_for = LITE_RUNTIME;
 option java_package = "map_lite_test";

java/core/src/test/proto/com/google/protobuf/nested_builders_test.proto

@@ -45,6 +45,11 @@ message Vehicle {
 message Engine {
   optional int32 cylinder = 1;
   optional int32 liters = 2;
+  optional TimingBelt timing_belt = 3;
+}
+
+message TimingBelt {
+  optional int32 number_of_teeth = 1;
 }
 
 message Wheel {

java/kotlin-lite/src/main/kotlin/com/google/protobuf/ExtendableMessageLiteExtensions.kt

@@ -37,22 +37,19 @@ import com.google.protobuf.GeneratedMessageLite
 operator fun <
   M : GeneratedMessageLite.ExtendableMessage<M, *>,
   MOrBT : GeneratedMessageLite.ExtendableMessageOrBuilder<M, *>,
-  T : Any
-  > MOrBT.get(extension: ExtensionLite<M, T>): T = getExtension(extension)
+  T : Any> MOrBT.get(extension: ExtensionLite<M, T>): T = getExtension(extension)
 
 /** Sets the current value of the proto extension in this builder. */
 operator fun <
   M : GeneratedMessageLite.ExtendableMessage<M, B>,
   B : GeneratedMessageLite.ExtendableBuilder<M, B>,
-  T : Any
-  > B.set(extension: ExtensionLite<M, T>, value: T) {
+  T : Any> B.set(extension: ExtensionLite<M, T>, value: T) {
   setExtension(extension, value)
 }
 
 /** Returns true if the specified extension is set. */
 operator fun <
   M : GeneratedMessageLite.ExtendableMessage<M, *>,
-  MorBT : GeneratedMessageLite.ExtendableMessageOrBuilder<M, *>
-  > MorBT.contains(
+  MorBT : GeneratedMessageLite.ExtendableMessageOrBuilder<M, *>> MorBT.contains(
   extension: ExtensionLite<M, *>
 ): Boolean = hasExtension(extension)

java/kotlin-lite/src/test/kotlin/com/google/protobuf/ExtendableMessageLiteExtensionsTest.kt

@@ -48,31 +48,27 @@ class ExtendableMessageLiteExtensionsTest {
 
   @Test
   fun getOnBuilder() {
-    val builder = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
+    val builder = ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6)
     assertThat(builder[TestProto.int32Extension]).isEqualTo(6)
   }
 
   @Test
   fun getOnMessage() {
-    val message = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
-      .build()
+    val message =
+      ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6).build()
     assertThat(message[TestProto.int32Extension]).isEqualTo(6)
   }
 
   @Test
   fun containsPositiveOnMessage() {
-    val message = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
-      .build()
+    val message =
+      ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6).build()
     assertThat(TestProto.int32Extension in message).isTrue()
   }
 
   @Test
   fun containsPositiveOnBuilder() {
-    val builder = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
+    val builder = ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6)
     assertThat(TestProto.int32Extension in builder).isTrue()
   }
 

java/kotlin/src/main/kotlin/com/google/protobuf/DslList.kt

@@ -39,9 +39,9 @@ package com.google.protobuf.kotlin
  * class directly in any way.
  */
 @Suppress("unused") // the unused type parameter
-class DslList<E, P : DslProxy> @OnlyForUseByGeneratedProtoCode constructor(
-  private val delegate: List<E>
-) : List<E> by delegate {
+class DslList<E, P : DslProxy>
+@OnlyForUseByGeneratedProtoCode
+constructor(private val delegate: List<E>) : List<E> by delegate {
   override fun iterator(): Iterator<E> = UnmodifiableIterator(delegate.iterator())
 
   override fun listIterator(): ListIterator<E> = UnmodifiableListIterator(delegate.listIterator())

java/kotlin/src/main/kotlin/com/google/protobuf/DslMap.kt

@@ -39,9 +39,9 @@ package com.google.protobuf.kotlin
  * class directly in any way.
  */
 @Suppress("unused") // the unused type parameter
-class DslMap<K, V, P : DslProxy> @OnlyForUseByGeneratedProtoCode constructor(
-  private val delegate: Map<K, V>
-) : Map<K, V> by delegate {
+class DslMap<K, V, P : DslProxy>
+@OnlyForUseByGeneratedProtoCode
+constructor(private val delegate: Map<K, V>) : Map<K, V> by delegate {
   // We allocate the wrappers on calls to get, not with lazy {...}, because lazy allocates
   // a few objects up front, and any kind of query operation on this object should be rare.
 

java/kotlin/src/main/kotlin/com/google/protobuf/DslProxy.kt

@@ -31,9 +31,9 @@
 package com.google.protobuf.kotlin
 
 /**
- * A type meaningful only for its existence, never intended to be instantiated.  For example,
- * a `DslList<Int, FooProxy>` can be given different extension methods than a
- * `DslList<Int, BarProxy>`.
+ * A type meaningful only for its existence, never intended to be instantiated. For example, a
+ * `DslList<Int, FooProxy>` can be given different extension methods than a `DslList<Int,
+ * BarProxy>`.
  */
 abstract class DslProxy @OnlyForUseByGeneratedProtoCode protected constructor() {
   init {

java/kotlin/src/main/kotlin/com/google/protobuf/ExtendableMessageExtensions.kt

@@ -33,12 +33,11 @@ package com.google.protobuf.kotlin
 import com.google.protobuf.ExtensionLite
 import com.google.protobuf.GeneratedMessageV3
 
-/** Sets the current value of the proto extension in this builder.*/
+/** Sets the current value of the proto extension in this builder. */
 operator fun <
   M : GeneratedMessageV3.ExtendableMessage<M>,
   B : GeneratedMessageV3.ExtendableBuilder<M, B>,
-  T : Any
-  > B.set(extension: ExtensionLite<M, T>, value: T) {
+  T : Any> B.set(extension: ExtensionLite<M, T>, value: T) {
   setExtension(extension, value)
 }
 
@@ -46,11 +45,11 @@ operator fun <
 operator fun <
   M : GeneratedMessageV3.ExtendableMessage<M>,
   MorBT : GeneratedMessageV3.ExtendableMessageOrBuilder<M>,
-  T : Any
-  > MorBT.get(extension: ExtensionLite<M, T>): T = getExtension(extension)
+  T : Any> MorBT.get(extension: ExtensionLite<M, T>): T = getExtension(extension)
 
 /** Returns true if the specified extension is set on this builder. */
 operator fun <
   M : GeneratedMessageV3.ExtendableMessage<M>,
-  MorBT : GeneratedMessageV3.ExtendableMessageOrBuilder<M>
-  > MorBT.contains(extension: ExtensionLite<M, *>): Boolean = hasExtension(extension)
+  MorBT : GeneratedMessageV3.ExtendableMessageOrBuilder<M>> MorBT.contains(
+  extension: ExtensionLite<M, *>
+): Boolean = hasExtension(extension)

java/kotlin/src/main/kotlin/com/google/protobuf/OnlyForUseByGeneratedProtoCode.kt

@@ -32,8 +32,8 @@ package com.google.protobuf.kotlin
 
 /**
  * Opt-in annotation to make it difficult to accidentally use APIs only intended for use by proto
- * generated code.  See https://kotlinlang.org/docs/reference/opt-in-requirements.html for details
- * on how this API works.
+ * generated code. See https://kotlinlang.org/docs/reference/opt-in-requirements.html for details on
+ * how this API works.
  */
 @RequiresOptIn(
   message =

java/kotlin/src/main/kotlin/com/google/protobuf/ProtoDslMarker.kt

@@ -30,9 +30,7 @@
 
 package com.google.protobuf.kotlin
 
-/**
- * Indicates an API that is part of a DSL to generate protocol buffer messages.
- */
+/** Indicates an API that is part of a DSL to generate protocol buffer messages. */
 @DslMarker
 @Target(AnnotationTarget.CLASS)
 @Retention(AnnotationRetention.BINARY)

java/kotlin/src/main/kotlin/com/google/protobuf/UnmodifiableCollections.kt

@@ -34,29 +34,24 @@ package com.google.protobuf.kotlin
 internal class UnmodifiableIterator<E>(delegate: Iterator<E>) : Iterator<E> by delegate
 
 /** Wraps a [ListIterator] and makes it unmodifiable even from Java. */
-internal class UnmodifiableListIterator<E>(
-  delegate: ListIterator<E>
-) : ListIterator<E> by delegate
+internal class UnmodifiableListIterator<E>(delegate: ListIterator<E>) : ListIterator<E> by delegate
 
 /** Wraps a [Collection] and makes it unmodifiable even from Java. */
-internal open class UnmodifiableCollection<E>(
-  private val delegate: Collection<E>
-) : Collection<E> by delegate {
+internal open class UnmodifiableCollection<E>(private val delegate: Collection<E>) :
+  Collection<E> by delegate {
   override fun iterator(): Iterator<E> = UnmodifiableIterator(delegate.iterator())
 }
 
 /** Wraps a [Set] and makes it unmodifiable even from Java. */
-internal class UnmodifiableSet<E>(
-  delegate: Collection<E>
-) : UnmodifiableCollection<E>(delegate), Set<E>
+internal class UnmodifiableSet<E>(delegate: Collection<E>) :
+  UnmodifiableCollection<E>(delegate), Set<E>
 
 /** Wraps a [Map.Entry] and makes it unmodifiable even from Java. */
 internal class UnmodifiableMapEntry<K, V>(delegate: Map.Entry<K, V>) : Map.Entry<K, V> by delegate
 
 /** Wraps a [Set] of map entries and makes it unmodifiable even from Java. */
-internal class UnmodifiableMapEntries<K, V>(
-  private val delegate: Set<Map.Entry<K, V>>
-) : UnmodifiableCollection<Map.Entry<K, V>>(delegate), Set<Map.Entry<K, V>> {
+internal class UnmodifiableMapEntries<K, V>(private val delegate: Set<Map.Entry<K, V>>) :
+  UnmodifiableCollection<Map.Entry<K, V>>(delegate), Set<Map.Entry<K, V>> {
 
   // Is this overkill? Probably.
 

java/kotlin/src/test/kotlin/com/google/protobuf/DslListTest.kt

@@ -67,9 +67,7 @@ class DslListTest {
   fun dslListIsNotEvenSecretlyMutable() {
     val dslList = DslList<Int, DummyProxy>(mutableListOf(1, 2, 3))
     val dslListAsJavaUtil = dslList as java.util.List<Int>
-    assertFailsWith<UnsupportedOperationException> {
-      dslListAsJavaUtil.add(4)
-    }
+    assertFailsWith<UnsupportedOperationException> { dslListAsJavaUtil.add(4) }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -79,9 +77,7 @@ class DslListTest {
     val iterator = dslList.iterator() as java.util.Iterator<Int>
     iterator.next()
 
-    assertFailsWith<UnsupportedOperationException> {
-      iterator.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { iterator.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -91,9 +87,7 @@ class DslListTest {
     val iterator = dslList.listIterator() as java.util.ListIterator<Int>
     iterator.next()
 
-    assertFailsWith<UnsupportedOperationException> {
-      iterator.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { iterator.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -103,9 +97,7 @@ class DslListTest {
     val iterator = dslList.listIterator(1) as java.util.ListIterator<Int>
     iterator.next()
 
-    assertFailsWith<UnsupportedOperationException> {
-      iterator.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { iterator.remove() }
   }
 
   @Test

java/kotlin/src/test/kotlin/com/google/protobuf/DslMapTest.kt

@@ -44,8 +44,7 @@ class DslMapTest {
 
   @Test
   fun matchesMap() {
-    assertThat(DslMap<Int, Int, DummyProxy>(mapOf(1 to -1, 2 to -2)))
-      .containsExactly(1, -1, 2, -2)
+    assertThat(DslMap<Int, Int, DummyProxy>(mapOf(1 to -1, 2 to -2))).containsExactly(1, -1, 2, -2)
   }
 
   @Test
@@ -91,9 +90,7 @@ class DslMapTest {
   fun dslMapIsNotEvenSecretlyMutable() {
     val dslMap = DslMap<Int, Int, DummyProxy>(mutableMapOf(1 to -1))
     val dslMapAsJavaUtilMap = dslMap as java.util.Map<Int, Int>
-    assertFailsWith<UnsupportedOperationException> {
-      dslMapAsJavaUtilMap.put(2, -2)
-    }
+    assertFailsWith<UnsupportedOperationException> { dslMapAsJavaUtilMap.put(2, -2) }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -101,9 +98,7 @@ class DslMapTest {
   fun dslMapKeysAreNotEvenSecretlyMutable() {
     val dslMap = DslMap<Int, Int, DummyProxy>(mutableMapOf(1 to -1))
     val dslMapKeysAsJavaUtilSet = dslMap.keys as java.util.Set<Int>
-    assertFailsWith<UnsupportedOperationException> {
-      dslMapKeysAsJavaUtilSet.remove(1)
-    }
+    assertFailsWith<UnsupportedOperationException> { dslMapKeysAsJavaUtilSet.remove(1) }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -113,9 +108,7 @@ class DslMapTest {
     val dslMapKeysAsJavaUtilSet = dslMap.keys as java.util.Set<Int>
     val itr = dslMapKeysAsJavaUtilSet.iterator()
     itr.next()
-    assertFailsWith<UnsupportedOperationException> {
-      itr.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { itr.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -123,9 +116,7 @@ class DslMapTest {
   fun dslMapValuesAreNotEvenSecretlyMutable() {
     val dslMap = DslMap<Int, Int, DummyProxy>(mutableMapOf(1 to -1))
     val dslMapValuesAsJavaUtilCollection = dslMap.values as java.util.Collection<Int>
-    assertFailsWith<UnsupportedOperationException> {
-      dslMapValuesAsJavaUtilCollection.remove(1)
-    }
+    assertFailsWith<UnsupportedOperationException> { dslMapValuesAsJavaUtilCollection.remove(1) }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -135,9 +126,7 @@ class DslMapTest {
     val dslMapValuesAsJavaUtilCollection = dslMap.values as java.util.Collection<Int>
     val itr = dslMapValuesAsJavaUtilCollection.iterator()
     itr.next()
-    assertFailsWith<UnsupportedOperationException> {
-      itr.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { itr.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -146,9 +135,7 @@ class DslMapTest {
     val dslMap = DslMap<Int, Int, DummyProxy>(mutableMapOf(1 to -1))
     val dslMapEntriesAsJavaUtilSet = dslMap.entries as java.util.Set<Map.Entry<Int, Int>>
     val entry = dslMap.entries.single()
-    assertFailsWith<UnsupportedOperationException> {
-      dslMapEntriesAsJavaUtilSet.remove(entry)
-    }
+    assertFailsWith<UnsupportedOperationException> { dslMapEntriesAsJavaUtilSet.remove(entry) }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -158,9 +145,7 @@ class DslMapTest {
     val dslMapEntriesAsJavaUtilSet = dslMap.entries as java.util.Set<Map.Entry<Int, Int>>
     val itr = dslMapEntriesAsJavaUtilSet.iterator()
     itr.next()
-    assertFailsWith<UnsupportedOperationException> {
-      itr.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { itr.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
@@ -168,9 +153,7 @@ class DslMapTest {
   fun dslMapEntryObjectsAreNotEvenSecretlyMutable() {
     val dslMap = DslMap<Int, Int, DummyProxy>(mutableMapOf(1 to -1))
     val dslMapEntryAsJavaUtilMapEntry = dslMap.entries.single() as java.util.Map.Entry<Int, Int>
-    assertFailsWith<UnsupportedOperationException> {
-      dslMapEntryAsJavaUtilMapEntry.value = 2
-    }
+    assertFailsWith<UnsupportedOperationException> { dslMapEntryAsJavaUtilMapEntry.value = 2 }
   }
 
   @Test

java/kotlin/src/test/kotlin/com/google/protobuf/ExtendableMessageExtensionsTest.kt

@@ -48,31 +48,27 @@ class ExtendableMessageExtensionsTest {
 
   @Test
   fun getOnBuilder() {
-    val builder = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
+    val builder = ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6)
     assertThat(builder[TestProto.int32Extension]).isEqualTo(6)
   }
 
   @Test
   fun getOnMessage() {
-    val message = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
-      .build()
+    val message =
+      ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6).build()
     assertThat(message[TestProto.int32Extension]).isEqualTo(6)
   }
 
   @Test
   fun containsPositiveOnMessage() {
-    val message = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
-      .build()
+    val message =
+      ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6).build()
     assertThat(TestProto.int32Extension in message).isTrue()
   }
 
   @Test
   fun containsPositiveOnBuilder() {
-    val builder = ExampleExtensibleMessage.newBuilder()
-      .setExtension(TestProto.int32Extension, 6)
+    val builder = ExampleExtensibleMessage.newBuilder().setExtension(TestProto.int32Extension, 6)
     assertThat(TestProto.int32Extension in builder).isTrue()
   }
 

java/kotlin/src/test/kotlin/com/google/protobuf/ExtensionListTest.kt

@@ -48,26 +48,27 @@ class ExtensionListTest {
   @Test
   fun matchesList() {
     assertThat(
-      ExtensionList<Int, ExampleExtensibleMessage>(
-        TestProto.repeatedExtension, listOf(1, 2, 3)
+        ExtensionList<Int, ExampleExtensibleMessage>(TestProto.repeatedExtension, listOf(1, 2, 3))
       )
-    ).containsExactly(1, 2, 3).inOrder()
+      .containsExactly(1, 2, 3)
+      .inOrder()
   }
 
   @Test
   fun reflectsChangesInList() {
     val mutableList = mutableListOf(1, 2, 3)
-    val extensionList = ExtensionList<Int, ExampleExtensibleMessage>(
-      TestProto.repeatedExtension, mutableList
-    )
+    val extensionList =
+      ExtensionList<Int, ExampleExtensibleMessage>(TestProto.repeatedExtension, mutableList)
     mutableList.add(4)
     assertThat(extensionList).containsExactly(1, 2, 3, 4).inOrder()
   }
 
   @Test
   fun extensionListIsNotMutable() {
-    val extensionList = ExtensionList<Int, ExampleExtensibleMessage>(
-      TestProto.repeatedExtension, mutableListOf(1, 2, 3)
+    val extensionList =
+      ExtensionList<Int, ExampleExtensibleMessage>(
+        TestProto.repeatedExtension,
+        mutableListOf(1, 2, 3)
       )
     assertThat(extensionList is MutableList<*>).isFalse()
   }
@@ -75,55 +76,55 @@ class ExtensionListTest {
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
   @Test
   fun extensionListIsNotEvenSecretlyMutable() {
-    val extensionList = ExtensionList<Int, ExampleExtensibleMessage>(
-      TestProto.repeatedExtension, mutableListOf(1, 2, 3)
+    val extensionList =
+      ExtensionList<Int, ExampleExtensibleMessage>(
+        TestProto.repeatedExtension,
+        mutableListOf(1, 2, 3)
       )
     val extensionListAsJavaUtil = extensionList as java.util.List<Int>
-    assertFailsWith<UnsupportedOperationException> {
-      extensionListAsJavaUtil.add(4)
-    }
+    assertFailsWith<UnsupportedOperationException> { extensionListAsJavaUtil.add(4) }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
   @Test
   fun extensionList_IteratorIsNotEvenSecretlyMutable() {
-    val extensionList = ExtensionList<Int, ExampleExtensibleMessage>(
-      TestProto.repeatedExtension, mutableListOf(1, 2, 3)
+    val extensionList =
+      ExtensionList<Int, ExampleExtensibleMessage>(
+        TestProto.repeatedExtension,
+        mutableListOf(1, 2, 3)
       )
     val iterator = extensionList.iterator() as java.util.Iterator<Int>
     iterator.next()
 
-    assertFailsWith<UnsupportedOperationException> {
-      iterator.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { iterator.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
   @Test
   fun extensionList_ListIteratorIsNotEvenSecretlyMutable() {
-    val extensionList = ExtensionList<Int, ExampleExtensibleMessage>(
-      TestProto.repeatedExtension, mutableListOf(1, 2, 3)
+    val extensionList =
+      ExtensionList<Int, ExampleExtensibleMessage>(
+        TestProto.repeatedExtension,
+        mutableListOf(1, 2, 3)
       )
     val iterator = extensionList.listIterator() as java.util.ListIterator<Int>
     iterator.next()
 
-    assertFailsWith<UnsupportedOperationException> {
-      iterator.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { iterator.remove() }
   }
 
   @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "UNCHECKED_CAST")
   @Test
   fun extensionList_ListIteratorIndexIsNotEvenSecretlyMutable() {
-    val extensionList = ExtensionList<Int, ExampleExtensibleMessage>(
-      TestProto.repeatedExtension, mutableListOf(1, 2, 3)
+    val extensionList =
+      ExtensionList<Int, ExampleExtensibleMessage>(
+        TestProto.repeatedExtension,
+        mutableListOf(1, 2, 3)
       )
     val iterator = extensionList.listIterator(1) as java.util.ListIterator<Int>
     iterator.next()
 
-    assertFailsWith<UnsupportedOperationException> {
-      iterator.remove()
-    }
+    assertFailsWith<UnsupportedOperationException> { iterator.remove() }
   }
 
   @Test
@@ -131,7 +132,8 @@ class ExtensionListTest {
     assertThat(
         ExtensionList<Int, ExampleExtensibleMessage>(TestProto.repeatedExtension, listOf(1, 2))
           .toString()
-    ).isEqualTo("[1, 2]")
+      )
+      .isEqualTo("[1, 2]")
   }
 
   @Test

protobuf_deps.bzl

@@ -67,8 +67,8 @@ def protobuf_deps():
         _github_archive(
             name = "utf8_range",
             repo = "https://github.com/protocolbuffers/utf8_range",
-            commit = "45fbf543fec00020a08650791a37575319a3ea1d",
-            sha256 = "dd93db062025f563068abaa224549e9d341434b5851e959c7853dfa263c96416",
+            commit = "a67b76f9f40107f2c78a5aa860bb6ce37ed83d85",
+            sha256 = "de5f99318f3b5073dd99f3d4ca31e00e90a86cc400fb375e2147ae1fd41711ed",
         )
 
     if not native.existing_rule("rules_cc"):

python/google/protobuf/internal/any_test.proto

@@ -39,7 +39,7 @@ import "google/protobuf/any.proto";
 message TestAny {
   optional google.protobuf.Any value = 1;
   optional int32 int_value = 2;
-  map<string,int32> map_value = 3;
+  map<string, int32> map_value = 3;
   extensions 10 to max;
 }
 

python/google/protobuf/internal/descriptor_pool_test.py

@@ -1127,33 +1127,49 @@ TEST1_FILE = ProtoFile(
 
 TEST2_FILE = ProtoFile(
     'google/protobuf/internal/descriptor_pool_test2.proto',
-    'google.protobuf.python.internal',
+    'google.protobuf.python.internal', {
+        'DescriptorPoolTest3':
+            MessageType(
                 {
-        'DescriptorPoolTest3': MessageType({
-            'NestedEnum': EnumType([('NU', 13), ('XI', 14)]),
-            'NestedMessage': MessageType({
-                'NestedEnum': EnumType([('OMICRON', 15), ('PI', 16)]),
-                'DeepNestedMessage': MessageType({
-                    'NestedEnum': EnumType([('RHO', 17), ('SIGMA', 18)]),
+                    'NestedEnum':
+                        EnumType([('NU', 13), ('XI', 14)]),
+                    'NestedMessage':
+                        MessageType(
+                            {
+                                'NestedEnum':
+                                    EnumType([('OMICRON', 15), ('PI', 16)]),
+                                'DeepNestedMessage':
+                                    MessageType(
+                                        {
+                                            'NestedEnum':
+                                                EnumType([('RHO', 17),
+                                                          ('SIGMA', 18)]),
                                         }, [
-                    ('nested_enum', EnumField(1, 'NestedEnum', 'RHO')),
-                    ('nested_field', StringField(2, 'sigma')),
+                                            ('nested_enum',
+                                             EnumField(1, 'NestedEnum', 'RHO')),
+                                            ('nested_field',
+                                             StringField(2, 'sigma')),
                                         ]),
                             }, [
-                ('nested_enum', EnumField(1, 'NestedEnum', 'PI')),
+                                ('nested_enum', EnumField(
+                                    1, 'NestedEnum', 'PI')),
                                 ('nested_field', StringField(2, 'nu')),
-                ('deep_nested_message', MessageField(3, 'DeepNestedMessage')),
+                                ('deep_nested_message',
+                                 MessageField(3, 'DeepNestedMessage')),
                             ])
                 }, [
                     ('nested_enum', EnumField(1, 'NestedEnum', 'XI')),
                     ('nested_message', MessageField(2, 'NestedMessage')),
-        ], extensions=[
+                ],
+                extensions=[
                     ('descriptor_pool_test',
                      ExtensionField(1001, 'DescriptorPoolTest1')),
                 ]),
     },
-    dependencies=['google/protobuf/internal/descriptor_pool_test1.proto',
-                  'google/protobuf/internal/more_messages.proto'],
+    dependencies=[
+        'google/protobuf/internal/more_messages.proto',
+        'google/protobuf/internal/descriptor_pool_test1.proto',
+    ],
     public_dependencies=['google/protobuf/internal/more_messages.proto'])
 
 

python/google/protobuf/internal/descriptor_pool_test1.proto

@@ -32,7 +32,6 @@ syntax = "proto2";
 
 package google.protobuf.python.internal;
 
-
 message DescriptorPoolTest1 {
   extensions 1000 to max;
 

python/google/protobuf/internal/descriptor_pool_test2.proto

@@ -32,12 +32,11 @@ syntax = "proto2";
 
 package google.protobuf.python.internal;
 
-import "google/protobuf/internal/descriptor_pool_test1.proto";
 import public "google/protobuf/internal/more_messages.proto";
 
+import "google/protobuf/internal/descriptor_pool_test1.proto";
 
 message DescriptorPoolTest3 {
-
   extend DescriptorPoolTest1 {
     optional DescriptorPoolTest3 descriptor_pool_test = 1001;
   }
@@ -70,4 +69,3 @@ message DescriptorPoolTest3 {
 
   optional NestedMessage nested_message = 2;
 }
-

python/google/protobuf/internal/descriptor_test.py

@@ -823,6 +823,16 @@ class DescriptorCopyToProtoTest(unittest.TestCase):
           deprecated: true
         >
       >
+      field {
+        name: "deprecated_message"
+        number: 3
+        label: LABEL_OPTIONAL
+        type: TYPE_MESSAGE
+        type_name: ".protobuf_unittest.TestAllTypes.NestedMessage"
+        options {
+          deprecated: true
+        }
+      }
       field {
         name: "deprecated_int32_in_oneof"
         number: 2

python/google/protobuf/internal/factory_test2.proto

@@ -36,7 +36,6 @@ package google.protobuf.python.internal;
 
 import "google/protobuf/internal/factory_test1.proto";
 
-
 enum Factory2Enum {
   FACTORY_2_VALUE_0 = 0;
   FACTORY_2_VALUE_1 = 1;
@@ -73,7 +72,6 @@ message Factory2Message {
   optional Factory2Enum enum_with_default = 20 [default = FACTORY_2_VALUE_1];
   optional bytes bytes_with_default = 21 [default = "a\373\000c"];
 
-
   extend Factory1Message {
     optional string one_more_field = 1001;
   }
@@ -100,5 +98,6 @@ extend Factory1Message {
 
 message MessageWithOption {
   option no_standard_descriptor_accessor = true;
+
   optional int32 field1 = 1;
 }

python/google/protobuf/internal/file_options_test.proto

@@ -30,10 +30,10 @@
 
 syntax = "proto2";
 
-import "google/protobuf/descriptor.proto";
-
 package google.protobuf.python.internal;
 
+import "google/protobuf/descriptor.proto";
+
 message FooOptions {
   optional string foo_name = 1;
 }

python/google/protobuf/internal/message_set_extensions.proto

@@ -31,12 +31,13 @@
 // This file contains messages that extend MessageSet.
 
 syntax = "proto2";
-package google.protobuf.internal;
 
+package google.protobuf.internal;
 
 // A message with message_set_wire_format.
 message TestMessageSet {
   option message_set_wire_format = true;
+
   extensions 4 to max;
 }
 

python/google/protobuf/internal/missing_enum_values.proto

@@ -43,7 +43,9 @@ message TestEnumValues {
 }
 
 message TestMissingEnumValues {
-  enum NestedEnum { TWO = 2; }
+  enum NestedEnum {
+    TWO = 2;
+  }
   optional NestedEnum optional_nested_enum = 1;
   repeated NestedEnum repeated_nested_enum = 2;
   repeated NestedEnum packed_nested_enum = 3 [packed = true];

python/google/protobuf/internal/more_extensions_dynamic.proto

@@ -36,10 +36,10 @@
 
 syntax = "proto2";
 
-import "google/protobuf/internal/more_extensions.proto";
-
 package google.protobuf.internal;
 
+import "google/protobuf/internal/more_extensions.proto";
+
 message DynamicMessageType {
   optional int32 a = 1;
 }

python/google/protobuf/internal/no_package.proto

@@ -1,3 +1,5 @@
+// NOLINT(no_package_specified): Test proto with no package
+
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

python/google/protobuf/internal/packed_field_test.proto

@@ -69,5 +69,6 @@ message TestUnpackedTypes {
   repeated float repeated_float = 11 [packed = false];
   repeated double repeated_double = 12 [packed = false];
   repeated bool repeated_bool = 13 [packed = false];
-  repeated TestPackedTypes.NestedEnum repeated_nested_enum = 14 [packed = false];
+  repeated TestPackedTypes.NestedEnum repeated_nested_enum = 14
+      [packed = false];
 }

python/google/protobuf/pyext/message.cc

@@ -70,7 +70,7 @@
 #include "google/protobuf/pyext/unknown_field_set.h"
 #include "google/protobuf/pyext/unknown_fields.h"
 #include "google/protobuf/util/message_differencer.h"
-#include "google/protobuf/stubs/strutil.h"
+#include "strings/util.h"
 #include "absl/strings/string_view.h"
 #include "google/protobuf/io/coded_stream.h"
 #include "google/protobuf/io/strtod.h"

src/file_lists.cmake

@@ -72,10 +72,7 @@ set(libprotobuf_srcs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_field.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_ptr_field.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/service.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/bytestream.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/common.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/structurally_valid.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/strutil.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/text_format.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/unknown_field_set.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/delimited_message_util.cc
@@ -173,7 +170,6 @@ set(libprotobuf_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_field.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_ptr_field.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/service.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/bytestream.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/callback.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/common.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/logging.h
@@ -181,7 +177,6 @@ set(libprotobuf_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/platform_macros.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/port.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/status_macros.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/strutil.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/text_format.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/unknown_field_set.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/util/delimited_message_util.h
@@ -220,10 +215,7 @@ set(libprotobuf_lite_srcs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/parse_context.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_field.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_ptr_field.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/bytestream.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/common.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/structurally_valid.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/strutil.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/wire_format_lite.cc
 )
 
@@ -264,7 +256,6 @@ set(libprotobuf_lite_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/port.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_field.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/repeated_ptr_field.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/bytestream.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/callback.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/common.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/logging.h
@@ -272,7 +263,6 @@ set(libprotobuf_lite_hdrs
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/platform_macros.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/port.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/status_macros.h
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/strutil.h
   ${protobuf_SOURCE_DIR}/src/google/protobuf/wire_format_lite.h
 )
 
@@ -725,8 +715,5 @@ set(util_test_protos_files
 
 # //src/google/protobuf/stubs:test_srcs
 set(stubs_test_files
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/bytestream_unittest.cc
   ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/common_unittest.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/structurally_valid_unittest.cc
-  ${protobuf_SOURCE_DIR}/src/google/protobuf/stubs/strutil_unittest.cc
 )

src/google/protobuf/BUILD.bazel

@@ -316,6 +316,7 @@ cc_library(
         "@com_google_absl//absl/strings:internal",
         "@com_google_absl//absl/synchronization",
         "@com_google_absl//absl/time",
+        "@utf8_range//:utf8_validity",
     ],
 )
 
@@ -385,6 +386,7 @@ cc_library(
         "@com_google_absl//absl/strings:internal",
         "@com_google_absl//absl/synchronization",
         "@com_google_absl//absl/time",
+        "@utf8_range//:utf8_validity",
     ],
 )
 

src/google/protobuf/any.proto

@@ -32,12 +32,12 @@ syntax = "proto3";
 
 package google.protobuf;
 
-option csharp_namespace = "Google.Protobuf.WellKnownTypes";
 option go_package = "google.golang.org/protobuf/types/known/anypb";
 option java_package = "com.google.protobuf";
 option java_outer_classname = "AnyProto";
 option java_multiple_files = true;
 option objc_class_prefix = "GPB";
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
 
 // `Any` contains an arbitrary serialized protocol buffer message along with a
 // URL that describes the type of the serialized message.

src/google/protobuf/api.proto

@@ -35,11 +35,11 @@ package google.protobuf;
 import "google/protobuf/source_context.proto";
 import "google/protobuf/type.proto";
 
-option csharp_namespace = "Google.Protobuf.WellKnownTypes";
 option java_package = "com.google.protobuf";
 option java_outer_classname = "ApiProto";
 option java_multiple_files = true;
 option objc_class_prefix = "GPB";
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
 option go_package = "google.golang.org/protobuf/types/known/apipb";
 
 // Api is a light-weight descriptor for an API Interface.

src/google/protobuf/arena_align.h

@@ -71,6 +71,9 @@
 #include "google/protobuf/stubs/common.h"
 #include "absl/numeric/bits.h"
 
+// Must be included last.
+#include "google/protobuf/port_def.inc"
+
 namespace google {
 namespace protobuf {
 namespace internal {
@@ -152,4 +155,6 @@ inline ArenaAlign ArenaAlignAs(size_t align) {
 }  // namespace protobuf
 }  // namespace google
 
+#include "google/protobuf/port_undef.inc"
+
 #endif  // GOOGLE_PROTOBUF_ARENA_ALIGN_H__

src/google/protobuf/arena_cleanup.h

@@ -40,6 +40,8 @@
 #include "absl/base/attributes.h"
 
 
+// Must be included last.
+#include "google/protobuf/port_def.inc"
 
 namespace google {
 namespace protobuf {
@@ -186,4 +188,6 @@ inline ABSL_ATTRIBUTE_ALWAYS_INLINE size_t Size(void (*destructor)(void*)) {
 }  // namespace protobuf
 }  // namespace google
 
+#include "google/protobuf/port_undef.inc"
+
 #endif  // GOOGLE_PROTOBUF_ARENA_CLEANUP_H__

src/google/protobuf/arena_config.cc

@@ -40,7 +40,7 @@ namespace google {
 namespace protobuf {
 namespace internal {
 
-PROTOBUF_CONSTINIT const size_t kDefaultDefaultArenaMaxBlockSize = 8 << 10;
+PROTOBUF_CONSTINIT const size_t kDefaultDefaultArenaMaxBlockSize = 32 << 10;
 
 namespace arena_config_internal {
 

src/google/protobuf/compiler/command_line_interface.cc

@@ -60,7 +60,6 @@
 
 #include <memory>
 #include <string>
-#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -74,10 +73,12 @@
 #include "google/protobuf/stubs/logging.h"
 #include "google/protobuf/compiler/subprocess.h"
 #include "google/protobuf/compiler/plugin.pb.h"
+#include "absl/container/flat_hash_set.h"
 #include "absl/strings/match.h"
 #include "absl/strings/str_format.h"
 #include "absl/strings/str_replace.h"
 #include "absl/strings/str_split.h"
+#include "absl/strings/string_view.h"
 #include "absl/strings/substitute.h"
 #include "google/protobuf/compiler/code_generator.h"
 #include "google/protobuf/compiler/importer.h"
@@ -1073,7 +1074,7 @@ int CommandLineInterface::Run(int argc, const char* const argv[]) {
 
       if (!generator) {
         // First time we've seen this output location.
-        generator.reset(new GeneratorContextImpl(parsed_files));
+        generator = std::make_unique<GeneratorContextImpl>(parsed_files);
       }
 
       if (!GenerateOutput(parsed_files, output_directives_[i],
@@ -2252,7 +2253,7 @@ bool CommandLineInterface::GenerateDependencyManifestFile(
   io::Printer printer(&out, '$');
 
   for (int i = 0; i < output_filenames.size(); i++) {
-    printer.Print(output_filenames[i].c_str());
+    printer.Print(output_filenames[i]);
     if (i == output_filenames.size() - 1) {
       printer.Print(":");
     } else {

src/google/protobuf/compiler/command_line_interface.h

@@ -44,11 +44,11 @@
 #include <memory>
 #include <set>
 #include <string>
-#include <unordered_map>
-#include <unordered_set>
 #include <utility>
 #include <vector>
 
+#include "absl/container/flat_hash_map.h"
+#include "absl/container/flat_hash_set.h"
 #include "absl/strings/string_view.h"
 #include "google/protobuf/port.h"
 
@@ -216,8 +216,8 @@ class PROTOC_EXPORT CommandLineInterface {
   class ErrorPrinter;
   class GeneratorContextImpl;
   class MemoryOutputStream;
-  typedef std::unordered_map<std::string, std::unique_ptr<GeneratorContextImpl>>
-      GeneratorContextMap;
+  using GeneratorContextMap =
+      absl::flat_hash_map<std::string, std::unique_ptr<GeneratorContextImpl>>;
 
   // Clear state from previous Run().
   void Clear();

src/google/protobuf/compiler/command_line_interface_unittest.cc

@@ -71,8 +71,6 @@
 #include "google/protobuf/io/printer.h"
 #include "google/protobuf/io/zero_copy_stream.h"
 
-#include "google/protobuf/stubs/strutil.h"
-
 // Must be included last.
 #include "google/protobuf/port_def.inc"
 

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

@@ -165,9 +165,9 @@ void EnumGenerator::GenerateDefinition(io::Printer* p) {
                                     p->LookupVar("Msg_Enum_"))}},
                      R"cc(
                        $Msg_Enum_Msg_Enum_$INT_MIN_SENTINEL_DO_NOT_USE_ =
-                           std::numeric_limits<int32_t>::min(),
+                           std::numeric_limits<::int32_t>::min(),
                        $Msg_Enum_Msg_Enum_$INT_MAX_SENTINEL_DO_NOT_USE_ =
-                           std::numeric_limits<int32_t>::max(),
+                           std::numeric_limits<::int32_t>::max(),
                      )cc");
            }},
       },
@@ -289,9 +289,12 @@ void EnumGenerator::GenerateGetEnumDescriptorSpecializations(io::Printer* p) {
 void EnumGenerator::GenerateSymbolImports(io::Printer* p) const {
   auto v = p->WithVars(EnumVars(enum_, options_, limits_.min, limits_.max));
 
+  {
+    auto a = p->WithVars({{"Enum_annotated", p->LookupVar("Enum_"), enum_}});
     p->Emit(R"cc(
-    using $Enum_$ = $Msg_Enum$;
+      using $Enum_annotated$ = $Msg_Enum$;
     )cc");
+  }
 
   for (int j = 0; j < enum_->value_count(); ++j) {
     const auto* value = enum_->value(j);

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

@@ -385,7 +385,7 @@ void RepeatedEnumFieldGenerator::GenerateByteSize(io::Printer* printer) const {
   Formatter format(printer, variables_);
   format(
       "{\n"
-      "  size_t data_size = 0;\n"
+      "  ::size_t data_size = 0;\n"
       "  unsigned int count = static_cast<unsigned "
       "int>(this->_internal_$name$_size());");
   format.Indent();

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

@@ -39,8 +39,6 @@
 #include <memory>
 #include <set>
 #include <string>
-#include <unordered_map>
-#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -53,7 +51,6 @@
 #include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
-#include "absl/strings/str_replace.h"
 #include "absl/strings/string_view.h"
 #include "absl/strings/strip.h"
 #include "google/protobuf/compiler/cpp/enum.h"
@@ -66,8 +63,6 @@
 #include "google/protobuf/descriptor.pb.h"
 #include "google/protobuf/io/printer.h"
 
-#include "google/protobuf/stubs/strutil.h"  // for StringReplace.
-
 // Must be last.
 #include "google/protobuf/port_def.inc"
 
@@ -379,7 +374,7 @@ void FileGenerator::GeneratePBHeader(io::Printer* p,
 
 void FileGenerator::DoIncludeFile(absl::string_view google3_name,
                                   bool do_export, io::Printer* p) {
-  absl::string_view prefix = "net/proto2/";
+  constexpr absl::string_view prefix = "net/proto2/";
   GOOGLE_CHECK(absl::StartsWith(google3_name, prefix)) << google3_name;
 
   auto v = p->WithVars(
@@ -387,18 +382,24 @@ void FileGenerator::DoIncludeFile(absl::string_view google3_name,
 
   if (options_.opensource_runtime) {
     absl::ConsumePrefix(&google3_name, prefix);
-    std::string path(google3_name);
+    absl::ConsumePrefix(&google3_name, "internal/");
+    absl::ConsumePrefix(&google3_name, "proto/");
+    absl::ConsumePrefix(&google3_name, "public/");
 
-    path = StringReplace(path, "internal/", "", false);
-    path = StringReplace(path, "proto/", "", false);
-    path = StringReplace(path, "public/", "", false);
+    std::string path;
+    if (absl::ConsumePrefix(&google3_name, "io/public/")) {
+      path = absl::StrCat("io/", google3_name);
+    } else {
+      path = std::string(google3_name);
+    }
 
     if (options_.runtime_include_base.empty()) {
       p->Emit({{"path", path}}, R"(
         #include "google/protobuf/$path$"$  export_suffix$
       )");
     } else {
-      p->Emit({{"base", options_.runtime_include_base}, {"path", path}}, R"(
+      p->Emit({{"base", options_.runtime_include_base}, {"path", path}},
+              R"(
         #include "$base$google/protobuf/$path$"$  export_suffix$
       )");
     }
@@ -407,8 +408,10 @@ void FileGenerator::DoIncludeFile(absl::string_view google3_name,
     // The bootstrapped proto generated code needs to use the
     // third_party/protobuf header paths to avoid circular dependencies.
     if (options_.bootstrap) {
-      path = StringReplace(path, "net/proto2/public", "third_party/protobuf",
-                           false);
+      constexpr absl::string_view bootstrap_prefix = "net/proto2/public";
+      if (absl::ConsumePrefix(&google3_name, bootstrap_prefix)) {
+        path = absl::StrCat("third_party/protobuf", google3_name);
+      }
     }
 
     p->Emit({{"path", path}}, R"(
@@ -928,7 +931,7 @@ void FileGenerator::GenerateReflectionInitializationCode(io::Printer* p) {
              }},
         },
         R"cc(
-          const uint32_t $tablename$::offsets[] PROTOBUF_SECTION_VARIABLE(
+          const ::uint32_t $tablename$::offsets[] PROTOBUF_SECTION_VARIABLE(
               protodesc_cold) = {
               $offsets$,
           };
@@ -947,7 +950,7 @@ void FileGenerator::GenerateReflectionInitializationCode(io::Printer* p) {
     //
     // MSVC doesn't like empty arrays, so we add a dummy.
     p->Emit(R"cc(
-      const uint32_t $tablename$::offsets[1] = {};
+      const ::uint32_t $tablename$::offsets[1] = {};
       static constexpr ::_pbi::MigrationSchema* schemas = nullptr;
       static constexpr ::_pb::Message* const* file_default_instances = nullptr;
     )cc");
@@ -1406,7 +1409,7 @@ void FileGenerator::GenerateGlobalStateFunctionDeclarations(io::Printer* p) {
   p->Emit(R"cc(
     // Internal implementation detail -- do not use these members.
     struct $dllexport_decl $$tablename$ {
-      static const uint32_t offsets[];
+      static const ::uint32_t offsets[];
     };
   )cc");
 

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

@@ -34,16 +34,14 @@
 
 #include "google/protobuf/compiler/cpp/generator.h"
 
+#include <cstdlib>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
-#include "google/protobuf/stubs/strutil.h"
-#include "google/protobuf/io/printer.h"
-#include "google/protobuf/io/zero_copy_stream.h"
+#include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
-#include "absl/strings/str_replace.h"
 #include "google/protobuf/compiler/cpp/file.h"
 #include "google/protobuf/compiler/cpp/helpers.h"
 #include "google/protobuf/descriptor.pb.h"
@@ -63,12 +61,12 @@ absl::flat_hash_map<std::string, std::string> CommonVars(
   return {
       {"proto_ns", ProtobufNamespace(options)},
       {"string", "std::string"},
-      {"int8", "int8_t"},
-      {"int32", "int32_t"},
-      {"int64", "int64_t"},
-      {"uint8", "uint8_t"},
-      {"uint32", "uint32_t"},
-      {"uint64", "uint64_t"},
+      {"int8", "::int8_t"},
+      {"int32", "::int32_t"},
+      {"int64", "::int64_t"},
+      {"uint8", "::uint8_t"},
+      {"uint32", "::uint32_t"},
+      {"uint64", "::uint64_t"},
 
       {"hrule_thick", kThickSeparator},
       {"hrule_thin", kThinSeparator},
@@ -152,7 +150,7 @@ bool CppGenerator::Generate(const FileDescriptor* file,
       file_options.enforce_mode = EnforceOptimizeMode::kLiteRuntime;
       file_options.lite_implicit_weak_fields = true;
       if (!value.empty()) {
-        file_options.num_cc_files = strto32(value.c_str(), nullptr, 10);
+        file_options.num_cc_files = std::strtol(value.c_str(), nullptr, 10);
       }
     } else if (key == "proto_h") {
       file_options.proto_h = true;

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

@@ -49,13 +49,10 @@
 #include "google/protobuf/stubs/common.h"
 #include "google/protobuf/stubs/logging.h"
 #include "google/protobuf/compiler/scc.h"
-#include "google/protobuf/io/printer.h"
-#include "google/protobuf/io/zero_copy_stream.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/dynamic_message.h"
 #include "google/protobuf/wire_format.h"
 #include "google/protobuf/wire_format_lite.h"
-#include "google/protobuf/stubs/strutil.h"
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/strings/ascii.h"
@@ -63,11 +60,13 @@
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_replace.h"
 #include "absl/strings/string_view.h"
+#include "absl/strings/strip.h"
 #include "absl/strings/substitute.h"
 #include "absl/synchronization/mutex.h"
 #include "google/protobuf/compiler/cpp/names.h"
 #include "google/protobuf/compiler/cpp/options.h"
 #include "google/protobuf/descriptor.pb.h"
+#include "google/protobuf/io/strtod.h"
 
 
 // Must be last.
@@ -172,7 +171,6 @@ static const char* const kKeywordList[] = {
     "while",
     "xor",
     "xor_eq",
-#ifdef PROTOBUF_FUTURE_CPP20_KEYWORDS  // C++20 keywords.
     "char8_t",
     "char16_t",
     "char32_t",
@@ -183,12 +181,11 @@ static const char* const kKeywordList[] = {
     "co_return",
     "co_yield",
     "requires",
-#endif  // !PROTOBUF_FUTURE_BREAKING_CHANGES
 };
 
-const absl::flat_hash_set<std::string>& Keywords() {
+const absl::flat_hash_set<absl::string_view>& Keywords() {
   static const auto* keywords = [] {
-    auto* keywords = new absl::flat_hash_set<std::string>();
+    auto* keywords = new absl::flat_hash_set<absl::string_view>();
 
     for (const auto keyword : kKeywordList) {
       keywords->emplace(keyword);
@@ -199,7 +196,7 @@ const absl::flat_hash_set<std::string>& Keywords() {
 }
 
 std::string IntTypeName(const Options& options, const std::string& type) {
-  return type + "_t";
+  return absl::StrCat("::", type, "_t");
 }
 
 // Returns true if the message can potentially allocate memory for its field.
@@ -409,16 +406,18 @@ std::string Namespace(const std::string& package) {
 }
 
 std::string Namespace(const FileDescriptor* d, const Options& options) {
-  std::string ret = Namespace(d->package());
+  std::string ns = Namespace(d->package());
   if (IsWellKnownMessage(d) && options.opensource_runtime) {
     // Written with string concatenation to prevent rewriting of
     // ::google::protobuf.
-    ret = StringReplace(ret,
-                        "::google::"
-                        "protobuf",
-                        "::PROTOBUF_NAMESPACE_ID", false);
+    constexpr absl::string_view prefix =
+        "::google::"  // prevent clang-format reflowing
+        "protobuf";
+    absl::string_view new_ns(ns);
+    absl::ConsumePrefix(&new_ns, prefix);
+    return absl::StrCat("::PROTOBUF_NAMESPACE_ID", new_ns);
   }
-  return ret;
+  return ns;
 }
 
 std::string Namespace(const Descriptor* d, const Options& options) {
@@ -591,13 +590,13 @@ std::string StripProto(const std::string& filename) {
 const char* PrimitiveTypeName(FieldDescriptor::CppType type) {
   switch (type) {
     case FieldDescriptor::CPPTYPE_INT32:
-      return "int32_t";
+      return "::int32_t";
     case FieldDescriptor::CPPTYPE_INT64:
-      return "int64_t";
+      return "::int64_t";
     case FieldDescriptor::CPPTYPE_UINT32:
-      return "uint32_t";
+      return "::uint32_t";
     case FieldDescriptor::CPPTYPE_UINT64:
-      return "uint64_t";
+      return "::uint64_t";
     case FieldDescriptor::CPPTYPE_DOUBLE:
       return "double";
     case FieldDescriptor::CPPTYPE_FLOAT:
@@ -713,13 +712,13 @@ static std::string Int64ToString(int64_t number) {
   if (number == std::numeric_limits<int64_t>::min()) {
     // This needs to be special-cased, see explanation here:
     // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52661
-    return absl::StrCat("int64_t{", number + 1, "} - 1");
+    return absl::StrCat("::int64_t{", number + 1, "} - 1");
   }
-  return absl::StrCat("int64_t{", number, "}");
+  return absl::StrCat("::int64_t{", number, "}");
 }
 
 static std::string UInt64ToString(uint64_t number) {
-  return absl::StrCat("uint64_t{", number, "u}");
+  return absl::StrCat("::uint64_t{", number, "u}");
 }
 
 std::string DefaultValue(const FieldDescriptor* field) {
@@ -745,7 +744,7 @@ std::string DefaultValue(const Options& options, const FieldDescriptor* field) {
       } else if (value != value) {
         return "std::numeric_limits<double>::quiet_NaN()";
       } else {
-        return SimpleDtoa(value);
+        return io::SimpleDtoa(value);
       }
     }
     case FieldDescriptor::CPPTYPE_FLOAT: {
@@ -757,7 +756,7 @@ std::string DefaultValue(const Options& options, const FieldDescriptor* field) {
       } else if (value != value) {
         return "std::numeric_limits<float>::quiet_NaN()";
       } else {
-        std::string float_value = SimpleFtoa(value);
+        std::string float_value = io::SimpleFtoa(value);
         // If floating point value contains a period (.) or an exponent
         // (either E or e), then append suffix 'f' to make it a float
         // literal.

src/google/protobuf/compiler/cpp/helpers.h

@@ -53,7 +53,6 @@
 #include "google/protobuf/io/printer.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/port.h"
-#include "google/protobuf/stubs/strutil.h"
 #include "absl/strings/str_cat.h"
 
 // Must be included last.

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

@@ -30,12 +30,10 @@
 
 #include "google/protobuf/compiler/cpp/map_field.h"
 
-#include "google/protobuf/io/printer.h"
 #include "google/protobuf/wire_format.h"
 #include "absl/strings/ascii.h"
 #include "google/protobuf/compiler/cpp/helpers.h"
-
-#include "google/protobuf/stubs/strutil.h"
+#include "absl/strings/str_cat.h"
 
 namespace google {
 namespace protobuf {

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

@@ -42,7 +42,6 @@
 #include <map>
 #include <memory>
 #include <type_traits>
-#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -62,6 +61,7 @@
 #include "google/protobuf/compiler/cpp/extension.h"
 #include "google/protobuf/compiler/cpp/field.h"
 #include "google/protobuf/compiler/cpp/helpers.h"
+#include "google/protobuf/compiler/cpp/names.h"
 #include "google/protobuf/compiler/cpp/padding_optimizer.h"
 #include "google/protobuf/compiler/cpp/parse_function_generator.h"
 #include "google/protobuf/descriptor.pb.h"
@@ -195,7 +195,7 @@ bool CanBeManipulatedAsRawBytes(const FieldDescriptor* field,
 // RunMap maps from fields that start each run to the number of fields in that
 // run.  This is optimized for the common case that there are very few runs in
 // a message and that most of the eligible fields appear together.
-using RunMap = std::unordered_map<const FieldDescriptor*, size_t>;
+using RunMap = absl::flat_hash_map<const FieldDescriptor*, size_t>;
 RunMap FindRuns(const std::vector<const FieldDescriptor*>& fields,
                 const std::function<bool(const FieldDescriptor*)>& predicate) {
   RunMap runs;
@@ -237,18 +237,18 @@ bool EmitFieldNonDefaultCondition(io::Printer* p, const std::string& prefix,
       format("if ($prefix$_internal_has_$name$()) {\n");
     } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_FLOAT) {
       format(
-          "static_assert(sizeof(uint32_t) == sizeof(float), \"Code assumes "
-          "uint32_t and float are the same size.\");\n"
+          "static_assert(sizeof(::uint32_t) == sizeof(float), \"Code assumes "
+          "::uint32_t and float are the same size.\");\n"
           "float tmp_$name$ = $prefix$_internal_$name$();\n"
-          "uint32_t raw_$name$;\n"
+          "::uint32_t raw_$name$;\n"
           "memcpy(&raw_$name$, &tmp_$name$, sizeof(tmp_$name$));\n"
           "if (raw_$name$ != 0) {\n");
     } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_DOUBLE) {
       format(
-          "static_assert(sizeof(uint64_t) == sizeof(double), \"Code assumes "
-          "uint64_t and double are the same size.\");\n"
+          "static_assert(sizeof(::uint64_t) == sizeof(double), \"Code assumes "
+          "::uint64_t and double are the same size.\");\n"
           "double tmp_$name$ = $prefix$_internal_$name$();\n"
-          "uint64_t raw_$name$;\n"
+          "::uint64_t raw_$name$;\n"
           "memcpy(&raw_$name$, &tmp_$name$, sizeof(tmp_$name$));\n"
           "if (raw_$name$ != 0) {\n");
     } else {
@@ -1661,7 +1661,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* p) {
           "PROTOBUF_ATTRIBUTE_REINITIALIZES void Clear() final;\n"
           "bool IsInitialized() const final;\n"
           "\n"
-          "size_t ByteSizeLong() const final;\n");
+          "::size_t ByteSizeLong() const final;\n");
 
       parse_function_generator_->GenerateMethodDecls(p);
 
@@ -1833,7 +1833,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* p) {
       num_required_fields_ > 1) {
     format(
         "// helper for ByteSizeLong()\n"
-        "size_t RequiredFieldsByteSizeFallback() const;\n\n");
+        "::size_t RequiredFieldsByteSizeFallback() const;\n\n");
   }
 
   if (HasGeneratedMethods(descriptor_->file(), options_)) {
@@ -2103,12 +2103,12 @@ void MessageGenerator::GenerateClassMethods(io::Printer* p) {
     format(
         "using HasBits = "
         "decltype(std::declval<$classname$>().$has_bits$);\n"
-        "static constexpr int32_t kHasBitsOffset =\n"
+        "static constexpr ::int32_t kHasBitsOffset =\n"
         "  8 * PROTOBUF_FIELD_OFFSET($classname$, _impl_._has_bits_);\n");
   }
   if (descriptor_->real_oneof_decl_count() > 0) {
     format(
-        "static constexpr int32_t kOneofCaseOffset =\n"
+        "static constexpr ::int32_t kOneofCaseOffset =\n"
         "  PROTOBUF_FIELD_OFFSET($classtype$, $oneof_case$);\n");
   }
   for (auto field : FieldRange(descriptor_)) {
@@ -2731,7 +2731,7 @@ void MessageGenerator::GenerateCopyConstructorBody(io::Printer* p) const {
 
   std::string pod_template =
       "::memcpy(&$first$, &from.$first$,\n"
-      "  static_cast<size_t>(reinterpret_cast<char*>(&$last$) -\n"
+      "  static_cast<::size_t>(reinterpret_cast<char*>(&$last$) -\n"
       "  reinterpret_cast<char*>(&$first$)) + sizeof($last$));\n";
 
   if (ShouldForceAllocationOnConstruction(descriptor_, options_)) {
@@ -3159,7 +3159,7 @@ void MessageGenerator::GenerateClear(io::Printer* p) {
         GOOGLE_CHECK_EQ(chunk_is_split, ShouldSplit(memset_start, options_));
         GOOGLE_CHECK_EQ(chunk_is_split, ShouldSplit(memset_end, options_));
         format(
-            "::memset(&$1$, 0, static_cast<size_t>(\n"
+            "::memset(&$1$, 0, static_cast<::size_t>(\n"
             "    reinterpret_cast<char*>(&$2$) -\n"
             "    reinterpret_cast<char*>(&$1$)) + sizeof($2$));\n",
             FieldMemberName(memset_start, chunk_is_split),
@@ -3656,7 +3656,7 @@ void MessageGenerator::GenerateCopyFrom(io::Printer* p) {
     if (HasDescriptorMethods(descriptor_->file(), options_)) {
       format("FailIfCopyFromDescendant(*this, from);\n");
     } else {
-      format("size_t from_size = from.ByteSizeLong();\n");
+      format("::size_t from_size = from.ByteSizeLong();\n");
     }
     format(
         "#endif\n"
@@ -4137,10 +4137,10 @@ void MessageGenerator::GenerateByteSize(io::Printer* p) {
   if (descriptor_->options().message_set_wire_format()) {
     // Special-case MessageSet.
     format(
-        "size_t $classname$::ByteSizeLong() const {\n"
+        "::size_t $classname$::ByteSizeLong() const {\n"
         "$annotate_bytesize$"
         "// @@protoc_insertion_point(message_set_byte_size_start:$full_name$)\n"
-        "  size_t total_size = $extensions$.MessageSetByteSize();\n"
+        "  ::size_t total_size = $extensions$.MessageSetByteSize();\n"
         "  if ($have_unknown_fields$) {\n"
         "    total_size += ::_pbi::\n"
         "        ComputeUnknownMessageSetItemsSize($unknown_fields$);\n"
@@ -4157,11 +4157,11 @@ void MessageGenerator::GenerateByteSize(io::Printer* p) {
     // Emit a function (rarely used, we hope) that handles the required fields
     // by checking for each one individually.
     format(
-        "size_t $classname$::RequiredFieldsByteSizeFallback() const {\n"
+        "::size_t $classname$::RequiredFieldsByteSizeFallback() const {\n"
         "// @@protoc_insertion_point(required_fields_byte_size_fallback_start:"
         "$full_name$)\n");
     format.Indent();
-    format("size_t total_size = 0;\n");
+    format("::size_t total_size = 0;\n");
     for (auto field : optimized_order_) {
       if (field->is_required()) {
         format(
@@ -4183,12 +4183,12 @@ void MessageGenerator::GenerateByteSize(io::Printer* p) {
   }
 
   format(
-      "size_t $classname$::ByteSizeLong() const {\n"
+      "::size_t $classname$::ByteSizeLong() const {\n"
       "$annotate_bytesize$"
       "// @@protoc_insertion_point(message_byte_size_start:$full_name$)\n");
   format.Indent();
   format(
-      "size_t total_size = 0;\n"
+      "::size_t total_size = 0;\n"
       "\n");
 
   if (descriptor_->extension_range_count() > 0) {

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

@@ -37,8 +37,7 @@
 #include "google/protobuf/io/printer.h"
 #include "google/protobuf/compiler/cpp/field.h"
 #include "google/protobuf/compiler/cpp/helpers.h"
-
-#include "google/protobuf/stubs/strutil.h"
+#include "absl/strings/str_cat.h"
 
 namespace google {
 namespace protobuf {

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

@@ -32,8 +32,10 @@
 
 #include <algorithm>
 #include <limits>
+#include <map>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "google/protobuf/wire_format.h"
 #include "absl/strings/str_cat.h"
@@ -59,7 +61,7 @@ bool UseDirectTcParserTable(const FieldDescriptor* field,
   return !m->options().message_set_wire_format() &&
          m->file()->options().optimize_for() != FileOptions::CODE_SIZE &&
          !HasSimpleBaseClass(m, options) && !HasTracker(m, options)
-      ;
+      ;  // NOLINT(whitespace/semicolon)
 }
 
 std::vector<const FieldDescriptor*> GetOrderedFields(
@@ -215,6 +217,17 @@ void ParseFunctionGenerator::GenerateTailcallParseFunction(Formatter& format) {
       "}\n\n");
 }
 
+static bool NeedsUnknownEnumSupport(const Descriptor* descriptor) {
+  for (int i = 0; i < descriptor->field_count(); ++i) {
+    auto* field = descriptor->field(i);
+    if (field->is_repeated() && field->cpp_type() == field->CPPTYPE_ENUM &&
+        !internal::cpp::HasPreservingUnknownEnumSemantics(field)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 void ParseFunctionGenerator::GenerateTailcallFallbackFunction(
     Formatter& format) {
   GOOGLE_CHECK(should_generate_tctable());
@@ -224,11 +237,27 @@ void ParseFunctionGenerator::GenerateTailcallFallbackFunction(
   format.Indent();
   format("auto* typed_msg = static_cast<$classname$*>(msg);\n");
 
+  // If we need a side channel, generate the check to jump to the generic
+  // handler to deal with the side channel data.
+  if (NeedsUnknownEnumSupport(descriptor_)) {
+    format(
+        "if (PROTOBUF_PREDICT_FALSE(\n"
+        "    _pbi::TcParser::MustFallbackToGeneric(PROTOBUF_TC_PARAM_PASS))) "
+        "{\n"
+        "  PROTOBUF_MUSTTAIL return "
+        "::_pbi::TcParser::GenericFallback$1$(PROTOBUF_TC_PARAM_PASS);\n"
+        "}\n",
+        GetOptimizeFor(descriptor_->file(), options_) ==
+                FileOptions::LITE_RUNTIME
+            ? "Lite"
+            : "");
+  }
+
   if (num_hasbits_ > 0) {
     // Sync hasbits
     format("typed_msg->_impl_._has_bits_[0] |= hasbits;\n");
   }
-  format("uint32_t tag = data.tag();\n");
+  format("::uint32_t tag = data.tag();\n");
 
   format.Set("msg", "typed_msg->");
   format.Set("this", "typed_msg");
@@ -343,7 +372,7 @@ void ParseFunctionGenerator::GenerateLoopingParseFunction(Formatter& format) {
   format.Indent();
 
   format(
-      "uint32_t tag;\n"
+      "::uint32_t tag;\n"
       "ptr = ::_pbi::ReadTag(ptr, &tag);\n");
   GenerateParseIterationBody(format, descriptor_, ordered_fields_);
 
@@ -645,8 +674,8 @@ void ParseFunctionGenerator::GenerateFastFieldEntries(Formatter& format) {
             absl::EndsWith(func_name, "V64S1")) {
           std::string field_type = absl::EndsWith(func_name, "V8S1") ? "bool"
                                    : absl::EndsWith(func_name, "V32S1")
-                                       ? "uint32_t"
-                                       : "uint64_t";
+                                       ? "::uint32_t"
+                                       : "::uint64_t";
           func_name = absl::StrCat(
               "::_pbi::TcParser::SingularVarintNoZag1<", field_type,
               ", offsetof(",                                 //
@@ -1352,8 +1381,9 @@ void ParseFunctionGenerator::GenerateFieldSwitch(
       format.Outdent();
     }
     format(
-        "} else\n"
+        "} else {\n"
         "  goto handle_unusual;\n"
+        "}\n"
         "$next_tag$;\n");
     format.Outdent();
   }  // for loop over ordered fields
@@ -1382,7 +1412,7 @@ void PopulateFastFieldEntry(const Descriptor* descriptor,
         ">()");
   } else if (name == "V32S1") {
     info.func_name = absl::StrCat(
-        "::_pbi::TcParser::SingularVarintNoZag1<uint32_t, offsetof(",  //
+        "::_pbi::TcParser::SingularVarintNoZag1<::uint32_t, offsetof(",  //
         ClassName(descriptor),                                           //
         ", ",                                                            //
         FieldMemberName(field, /*split=*/false),                         //
@@ -1391,7 +1421,7 @@ void PopulateFastFieldEntry(const Descriptor* descriptor,
         ">()");
   } else if (name == "V64S1") {
     info.func_name = absl::StrCat(
-        "::_pbi::TcParser::SingularVarintNoZag1<uint64_t, offsetof(",  //
+        "::_pbi::TcParser::SingularVarintNoZag1<::uint64_t, offsetof(",  //
         ClassName(descriptor),                                           //
         ", ",                                                            //
         FieldMemberName(field, /*split=*/false),                         //

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

@@ -467,13 +467,13 @@ void RepeatedPrimitiveFieldGenerator::GenerateByteSize(
   int fixed_size = FixedSize(descriptor_->type());
   if (fixed_size == -1) {
     format(
-        "size_t data_size = ::_pbi::WireFormatLite::\n"
+        "::size_t data_size = ::_pbi::WireFormatLite::\n"
         "  $declared_type$Size(this->$field$);\n");
   } else {
     format(
         "unsigned int count = static_cast<unsigned "
         "int>(this->_internal_$name$_size());\n"
-        "size_t data_size = $fixed_size$UL * count;\n");
+        "::size_t data_size = $fixed_size$UL * count;\n");
   }
 
   if (descriptor_->is_packed()) {

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

@@ -34,13 +34,10 @@
 
 #include "google/protobuf/compiler/cpp/string_field.h"
 
-#include "google/protobuf/io/printer.h"
 #include "absl/strings/str_cat.h"
 #include "google/protobuf/compiler/cpp/helpers.h"
 #include "google/protobuf/descriptor.pb.h"
 
-#include "google/protobuf/stubs/strutil.h"
-
 namespace google {
 namespace protobuf {
 namespace compiler {
@@ -729,7 +726,7 @@ void RepeatedStringFieldGenerator::GenerateAccessorDeclarations(
   }
   format(
       "$deprecated_attr$void ${1$set_$name$$}$("
-      "int index, const $pointer_type$* value, size_t size);\n"
+      "int index, const $pointer_type$* value, ::size_t size);\n"
       "$deprecated_attr$std::string* ${1$add_$name$$}$();\n"
       "$deprecated_attr$void ${1$add_$name$$}$(const std::string& value);\n"
       "$deprecated_attr$void ${1$add_$name$$}$(std::string&& value);\n"
@@ -742,7 +739,7 @@ void RepeatedStringFieldGenerator::GenerateAccessorDeclarations(
   }
   format(
       "$deprecated_attr$void ${1$add_$name$$}$(const $pointer_type$* "
-      "value, size_t size)"
+      "value, ::size_t size)"
       ";\n"
       "$deprecated_attr$const ::$proto_ns$::RepeatedPtrField<std::string>& "
       "${1$$name$$}$() "
@@ -828,7 +825,7 @@ void RepeatedStringFieldGenerator::GenerateInlineAccessorDefinitions(
   format(
       "inline void "
       "$classname$::set_$name$"
-      "(int index, const $pointer_type$* value, size_t size) {\n"
+      "(int index, const $pointer_type$* value, ::size_t size) {\n"
       "  $field$.Mutable(index)->assign(\n"
       "    reinterpret_cast<const char*>(value), size);\n"
       "$annotate_set$"
@@ -863,7 +860,7 @@ void RepeatedStringFieldGenerator::GenerateInlineAccessorDefinitions(
   }
   format(
       "inline void "
-      "$classname$::add_$name$(const $pointer_type$* value, size_t size) {\n"
+      "$classname$::add_$name$(const $pointer_type$* value, ::size_t size) {\n"
       "  $field$.Add()->assign(reinterpret_cast<const char*>(value), size);\n"
       "$annotate_add$"
       "  // @@protoc_insertion_point(field_add_pointer:$full_name$)\n"

src/google/protobuf/compiler/cpp/test_bad_identifiers.proto

@@ -93,11 +93,16 @@ message TestConflictingSymbolNames {
   optional int32 already_here = 15;
 
   optional uint32 uint32 = 16;
+  optional uint32 uint32_t = 41;
   optional uint64 uint64 = 17;
+  optional uint32 uint64_t = 42;
   optional string string = 18;
   optional int32 memset = 19;
   optional int32 int32 = 20;
+  optional int32 int32_t = 43;
   optional int64 int64 = 21;
+  optional int64 int64_t = 44;
+  optional int64 size_t = 45;
 
   optional uint32 cached_size = 22;
   optional uint32 extensions = 23;

src/google/protobuf/compiler/csharp/csharp_field_base.h

@@ -34,7 +34,6 @@
 #include <string>
 
 #include "google/protobuf/compiler/code_generator.h"
-#include "google/protobuf/stubs/strutil.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/escaping.h"
 #include "absl/strings/str_replace.h"

src/google/protobuf/compiler/csharp/csharp_map_field.cc

@@ -88,7 +88,7 @@ void MapFieldGenerator::GenerateMembers(io::Printer* printer) {
 void MapFieldGenerator::GenerateMergingCode(io::Printer* printer) {
   printer->Print(
       variables_,
-      "$name$_.MergeFrom(other.$name$_);\n");
+      "$name$_.Add(other.$name$_);\n");
 }
 
 void MapFieldGenerator::GenerateParsingCode(io::Printer* printer) {

src/google/protobuf/compiler/importer_unittest.cc

@@ -46,10 +46,9 @@
 #include "google/protobuf/testing/googletest.h"
 #include <gtest/gtest.h>
 #include "absl/container/flat_hash_map.h"
+#include "absl/status/status.h"
 #include "absl/strings/substitute.h"
 
-#include "google/protobuf/stubs/strutil.h"
-
 namespace google {
 namespace protobuf {
 namespace compiler {

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

@@ -37,18 +37,14 @@
 
 #include <memory>
 
-#include "google/protobuf/io/printer.h"
-#include "google/protobuf/io/zero_copy_stream.h"
 #include "absl/strings/str_format.h"
 #include "google/protobuf/compiler/java/file.h"
-#include "google/protobuf/compiler/java/generator_factory.h"
 #include "google/protobuf/compiler/java/helpers.h"
 #include "google/protobuf/compiler/java/name_resolver.h"
 #include "google/protobuf/compiler/java/options.h"
 #include "google/protobuf/compiler/java/shared_code_generator.h"
 #include "google/protobuf/descriptor.pb.h"
 
-#include "google/protobuf/stubs/strutil.h"
 
 namespace google {
 namespace protobuf {

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

@@ -40,7 +40,6 @@
 #include <vector>
 
 #include "google/protobuf/wire_format.h"
-#include "google/protobuf/stubs/strutil.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/escaping.h"
@@ -52,6 +51,7 @@
 #include "absl/strings/substitute.h"
 #include "google/protobuf/compiler/java/name_resolver.h"
 #include "google/protobuf/descriptor.pb.h"
+#include "google/protobuf/io/strtod.h"
 
 // Must be last.
 #include "google/protobuf/port_def.inc"
@@ -479,7 +479,7 @@ std::string DefaultValue(const FieldDescriptor* field, bool immutable,
       } else if (value != value) {
         return "Double.NaN";
       } else {
-        return SimpleDtoa(value) + "D";
+        return io::SimpleDtoa(value) + "D";
       }
     }
     case FieldDescriptor::CPPTYPE_FLOAT: {
@@ -491,7 +491,7 @@ std::string DefaultValue(const FieldDescriptor* field, bool immutable,
       } else if (value != value) {
         return "Float.NaN";
       } else {
-        return SimpleFtoa(value) + "F";
+        return io::SimpleFtoa(value) + "F";
       }
     }
     case FieldDescriptor::CPPTYPE_BOOL:

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

@@ -33,6 +33,7 @@ cc_library(
         ":line_consumer",
         "//src/google/protobuf/compiler:code_generator",
         "//src/google/protobuf:protobuf_nowkt",
+        "@com_google_absl//absl/container:flat_hash_set",
     ],
 )
 

src/google/protobuf/compiler/objectivec/enum.cc

@@ -31,7 +31,9 @@
 #include "google/protobuf/compiler/objectivec/enum.h"
 
 #include <algorithm>
+#include <limits>
 #include <map>
+#include <set>
 #include <string>
 
 #include "absl/strings/escaping.h"
@@ -90,8 +92,6 @@ EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor)
   }
 }
 
-EnumGenerator::~EnumGenerator() {}
-
 void EnumGenerator::GenerateHeader(io::Printer* printer) {
   std::string enum_comments;
   SourceLocation location;
@@ -151,7 +151,7 @@ void EnumGenerator::GenerateHeader(io::Printer* printer) {
         if (i > 0) {
           printer->Print("\n");
         }
-        printer->Print(comments.c_str());
+        printer->Print(comments);
       }
     }
 

src/google/protobuf/compiler/objectivec/enum.h

@@ -46,7 +46,7 @@ namespace objectivec {
 class EnumGenerator {
  public:
   explicit EnumGenerator(const EnumDescriptor* descriptor);
-  ~EnumGenerator();
+  ~EnumGenerator() = default;
 
   EnumGenerator(const EnumGenerator&) = delete;
   EnumGenerator& operator=(const EnumGenerator&) = delete;

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

@@ -31,6 +31,7 @@
 #include "google/protobuf/compiler/objectivec/enum_field.h"
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "google/protobuf/compiler/objectivec/helpers.h"
@@ -71,8 +72,6 @@ EnumFieldGenerator::EnumFieldGenerator(const FieldDescriptor* descriptor)
   SetEnumVariables(descriptor, &variables_);
 }
 
-EnumFieldGenerator::~EnumFieldGenerator() {}
-
 void EnumFieldGenerator::GenerateCFunctionDeclarations(
     io::Printer* printer) const {
   if (!HasPreservingUnknownEnumSemantics(descriptor_->file())) {
@@ -142,9 +141,7 @@ RepeatedEnumFieldGenerator::RepeatedEnumFieldGenerator(
   variables_["array_storage_type"] = "GPBEnumArray";
 }
 
-RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {}
-
-void RepeatedEnumFieldGenerator::FinishInitialization(void) {
+void RepeatedEnumFieldGenerator::FinishInitialization() {
   RepeatedFieldGenerator::FinishInitialization();
   variables_["array_comment"] = "// |" + variables_["name"] + "| contains |" +
                                 variables_["storage_type"] + "|\n";

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

@@ -32,6 +32,7 @@
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_ENUM_FIELD_H__
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "google/protobuf/compiler/objectivec/field.h"
@@ -48,28 +49,25 @@ class EnumFieldGenerator : public SingleFieldGenerator {
   EnumFieldGenerator& operator=(const EnumFieldGenerator&) = delete;
 
  public:
-  virtual void GenerateCFunctionDeclarations(
-      io::Printer* printer) const override;
-  virtual void GenerateCFunctionImplementations(
-      io::Printer* printer) const override;
-  virtual void DetermineForwardDeclarations(
-      std::set<std::string>* fwd_decls,
+  void GenerateCFunctionDeclarations(io::Printer* printer) const override;
+  void GenerateCFunctionImplementations(io::Printer* printer) const override;
+  void DetermineForwardDeclarations(std::set<std::string>* fwd_decls,
                                     bool include_external_types) const override;
 
  protected:
   explicit EnumFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~EnumFieldGenerator();
+  ~EnumFieldGenerator() override = default;
 };
 
 class RepeatedEnumFieldGenerator : public RepeatedFieldGenerator {
   friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
 
  public:
-  virtual void FinishInitialization() override;
+  void FinishInitialization() override;
 
  protected:
   explicit RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~RepeatedEnumFieldGenerator();
+  ~RepeatedEnumFieldGenerator() override = default;
 };
 
 }  // namespace objectivec

src/google/protobuf/compiler/objectivec/extension.cc

@@ -31,6 +31,11 @@
 #include "google/protobuf/compiler/objectivec/extension.h"
 
 #include <iostream>
+#include <map>
+#include <ostream>
+#include <set>
+#include <string>
+#include <vector>
 
 #include "absl/strings/str_cat.h"
 #include "google/protobuf/compiler/objectivec/helpers.h"
@@ -58,8 +63,6 @@ ExtensionGenerator::ExtensionGenerator(const std::string& root_class_name,
   }
 }
 
-ExtensionGenerator::~ExtensionGenerator() {}
-
 void ExtensionGenerator::GenerateMembersHeader(io::Printer* printer) {
   std::map<std::string, std::string> vars;
   vars["method_name"] = method_name_;

src/google/protobuf/compiler/objectivec/extension.h

@@ -31,6 +31,8 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_EXTENSION_H__
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_EXTENSION_H__
 
+#include <string>
+
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/io/printer.h"
 
@@ -43,7 +45,7 @@ class ExtensionGenerator {
  public:
   ExtensionGenerator(const std::string& root_class_name,
                      const FieldDescriptor* descriptor);
-  ~ExtensionGenerator();
+  ~ExtensionGenerator() = default;
 
   ExtensionGenerator(const ExtensionGenerator&) = delete;
   ExtensionGenerator& operator=(const ExtensionGenerator&) = delete;

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

@@ -31,6 +31,11 @@
 #include "google/protobuf/compiler/objectivec/field.h"
 
 #include <iostream>
+#include <map>
+#include <ostream>
+#include <set>
+#include <string>
+#include <vector>
 
 #include "absl/strings/str_cat.h"
 #include "google/protobuf/compiler/objectivec/enum_field.h"
@@ -166,7 +171,7 @@ bool HasNonZeroDefaultValue(const FieldDescriptor* field) {
 }  // namespace
 
 FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field) {
-  FieldGenerator* result = NULL;
+  FieldGenerator* result = nullptr;
   if (field->is_repeated()) {
     switch (GetObjectiveCType(field)) {
       case OBJECTIVECTYPE_MESSAGE: {
@@ -211,8 +216,6 @@ FieldGenerator::FieldGenerator(const FieldDescriptor* descriptor)
   SetCommonFieldVariables(descriptor, &variables_);
 }
 
-FieldGenerator::~FieldGenerator() {}
-
 void FieldGenerator::GenerateFieldNumberConstant(io::Printer* printer) const {
   printer->Print(variables_, "$field_number_name$ = $field_number$,\n");
 }
@@ -275,11 +278,9 @@ void FieldGenerator::SetRuntimeHasBit(int has_index) {
   variables_["has_index"] = absl::StrCat(has_index);
 }
 
-void FieldGenerator::SetNoHasBit(void) {
-  variables_["has_index"] = "GPBNoHasBit";
-}
+void FieldGenerator::SetNoHasBit() { variables_["has_index"] = "GPBNoHasBit"; }
 
-int FieldGenerator::ExtraRuntimeHasBitsNeeded(void) const { return 0; }
+int FieldGenerator::ExtraRuntimeHasBitsNeeded() const { return 0; }
 
 void FieldGenerator::SetExtraRuntimeHasBitsBase(int index_base) {
   // NOTE: src/google/protobuf/compiler/plugin.cc makes use of cerr for some
@@ -292,18 +293,18 @@ void FieldGenerator::SetExtraRuntimeHasBitsBase(int index_base) {
 
 void FieldGenerator::SetOneofIndexBase(int index_base) {
   const OneofDescriptor* oneof = descriptor_->real_containing_oneof();
-  if (oneof != NULL) {
+  if (oneof != nullptr) {
     int index = oneof->index() + index_base;
     // Flip the sign to mark it as a oneof.
     variables_["has_index"] = absl::StrCat(-index);
   }
 }
 
-bool FieldGenerator::WantsHasProperty(void) const {
+bool FieldGenerator::WantsHasProperty() const {
   return descriptor_->has_presence() && !descriptor_->real_containing_oneof();
 }
 
-void FieldGenerator::FinishInitialization(void) {
+void FieldGenerator::FinishInitialization() {
   // If "property_type" wasn't set, make it "storage_type".
   if ((variables_.find("property_type") == variables_.end()) &&
       (variables_.find("storage_type") != variables_.end())) {
@@ -316,8 +317,6 @@ SingleFieldGenerator::SingleFieldGenerator(const FieldDescriptor* descriptor)
   // Nothing
 }
 
-SingleFieldGenerator::~SingleFieldGenerator() {}
-
 void SingleFieldGenerator::GenerateFieldStorageDeclaration(
     io::Printer* printer) const {
   printer->Print(variables_, "$storage_type$ $name$;\n");
@@ -350,7 +349,7 @@ void SingleFieldGenerator::GeneratePropertyImplementation(
   }
 }
 
-bool SingleFieldGenerator::RuntimeUsesHasBit(void) const {
+bool SingleFieldGenerator::RuntimeUsesHasBit() const {
   if (descriptor_->real_containing_oneof()) {
     // The oneof tracks what is set instead.
     return false;
@@ -366,8 +365,6 @@ ObjCObjFieldGenerator::ObjCObjFieldGenerator(const FieldDescriptor* descriptor)
   }
 }
 
-ObjCObjFieldGenerator::~ObjCObjFieldGenerator() {}
-
 void ObjCObjFieldGenerator::GenerateFieldStorageDeclaration(
     io::Printer* printer) const {
   printer->Print(variables_, "$storage_type$ *$name$;\n");
@@ -410,9 +407,7 @@ RepeatedFieldGenerator::RepeatedFieldGenerator(
   variables_["array_comment"] = "";
 }
 
-RepeatedFieldGenerator::~RepeatedFieldGenerator() {}
-
-void RepeatedFieldGenerator::FinishInitialization(void) {
+void RepeatedFieldGenerator::FinishInitialization() {
   FieldGenerator::FinishInitialization();
   if (variables_.find("array_property_type") == variables_.end()) {
     variables_["array_property_type"] = variable("array_storage_type");
@@ -457,7 +452,7 @@ void RepeatedFieldGenerator::GeneratePropertyDeclaration(
   printer->Print("\n");
 }
 
-bool RepeatedFieldGenerator::RuntimeUsesHasBit(void) const {
+bool RepeatedFieldGenerator::RuntimeUsesHasBit() const {
   return false;  // The array (or map/dict) having anything is what is used.
 }
 
@@ -475,8 +470,6 @@ FieldGeneratorMap::FieldGeneratorMap(const Descriptor* descriptor)
   }
 }
 
-FieldGeneratorMap::~FieldGeneratorMap() {}
-
 const FieldGenerator& FieldGeneratorMap::get(
     const FieldDescriptor* field) const {
   GOOGLE_CHECK_EQ(field->containing_type(), descriptor_);
@@ -487,7 +480,7 @@ const FieldGenerator& FieldGeneratorMap::get_extension(int index) const {
   return *extension_generators_[index];
 }
 
-int FieldGeneratorMap::CalculateHasBits(void) {
+int FieldGeneratorMap::CalculateHasBits() {
   int total_bits = 0;
   for (int i = 0; i < descriptor_->field_count(); i++) {
     if (field_generators_[i]->RuntimeUsesHasBit()) {
@@ -511,7 +504,7 @@ void FieldGeneratorMap::SetOneofIndexBase(int index_base) {
   }
 }
 
-bool FieldGeneratorMap::DoesAnyFieldHaveNonZeroDefault(void) const {
+bool FieldGeneratorMap::DoesAnyFieldHaveNonZeroDefault() const {
   for (int i = 0; i < descriptor_->field_count(); i++) {
     if (HasNonZeroDefaultValue(descriptor_->field(i))) {
       return true;

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

@@ -32,8 +32,12 @@
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_FIELD_H__
 
 #include <map>
+#include <memory>
+#include <set>
 #include <string>
+#include <vector>
 
+#include "absl/strings/match.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/io/printer.h"
 
@@ -46,7 +50,7 @@ class FieldGenerator {
  public:
   static FieldGenerator* Make(const FieldDescriptor* field);
 
-  virtual ~FieldGenerator();
+  virtual ~FieldGenerator() = default;
 
   FieldGenerator(const FieldGenerator&) = delete;
   FieldGenerator& operator=(const FieldGenerator&) = delete;
@@ -75,10 +79,10 @@ class FieldGenerator {
   void GenerateFieldNumberConstant(io::Printer* printer) const;
 
   // Exposed to get and set the has bits information.
-  virtual bool RuntimeUsesHasBit(void) const = 0;
+  virtual bool RuntimeUsesHasBit() const = 0;
   void SetRuntimeHasBit(int has_index);
-  void SetNoHasBit(void);
-  virtual int ExtraRuntimeHasBitsNeeded(void) const;
+  void SetNoHasBit();
+  virtual int ExtraRuntimeHasBitsNeeded() const;
   virtual void SetExtraRuntimeHasBitsBase(int index_base);
   void SetOneofIndexBase(int index_base);
 
@@ -88,8 +92,7 @@ class FieldGenerator {
 
   bool needs_textformat_name_support() const {
     const std::string& field_flags = variable("fieldflags");
-    return field_flags.find("GPBFieldTextFormatNameCustom") !=
-           std::string::npos;
+    return absl::StrContains(field_flags, "GPBFieldTextFormatNameCustom");
   }
   std::string generated_objc_name() const { return variable("name"); }
   std::string raw_field_name() const { return variable("raw_field_name"); }
@@ -97,8 +100,8 @@ class FieldGenerator {
  protected:
   explicit FieldGenerator(const FieldDescriptor* descriptor);
 
-  virtual void FinishInitialization(void);
-  bool WantsHasProperty(void) const;
+  virtual void FinishInitialization();
+  bool WantsHasProperty() const;
 
   const FieldDescriptor* descriptor_;
   std::map<std::string, std::string> variables_;
@@ -106,19 +109,17 @@ class FieldGenerator {
 
 class SingleFieldGenerator : public FieldGenerator {
  public:
-  virtual ~SingleFieldGenerator();
+  ~SingleFieldGenerator() override = default;
 
   SingleFieldGenerator(const SingleFieldGenerator&) = delete;
   SingleFieldGenerator& operator=(const SingleFieldGenerator&) = delete;
 
-  virtual void GenerateFieldStorageDeclaration(
-      io::Printer* printer) const override;
-  virtual void GeneratePropertyDeclaration(io::Printer* printer) const override;
+  void GenerateFieldStorageDeclaration(io::Printer* printer) const override;
+  void GeneratePropertyDeclaration(io::Printer* printer) const override;
 
-  virtual void GeneratePropertyImplementation(
-      io::Printer* printer) const override;
+  void GeneratePropertyImplementation(io::Printer* printer) const override;
 
-  virtual bool RuntimeUsesHasBit(void) const override;
+  bool RuntimeUsesHasBit() const override;
 
  protected:
   explicit SingleFieldGenerator(const FieldDescriptor* descriptor);
@@ -127,14 +128,13 @@ class SingleFieldGenerator : public FieldGenerator {
 // Subclass with common support for when the field ends up as an ObjC Object.
 class ObjCObjFieldGenerator : public SingleFieldGenerator {
  public:
-  virtual ~ObjCObjFieldGenerator();
+  ~ObjCObjFieldGenerator() override = default;
 
   ObjCObjFieldGenerator(const ObjCObjFieldGenerator&) = delete;
   ObjCObjFieldGenerator& operator=(const ObjCObjFieldGenerator&) = delete;
 
-  virtual void GenerateFieldStorageDeclaration(
-      io::Printer* printer) const override;
-  virtual void GeneratePropertyDeclaration(io::Printer* printer) const override;
+  void GenerateFieldStorageDeclaration(io::Printer* printer) const override;
+  void GeneratePropertyDeclaration(io::Printer* printer) const override;
 
  protected:
   explicit ObjCObjFieldGenerator(const FieldDescriptor* descriptor);
@@ -142,30 +142,28 @@ class ObjCObjFieldGenerator : public SingleFieldGenerator {
 
 class RepeatedFieldGenerator : public ObjCObjFieldGenerator {
  public:
-  virtual ~RepeatedFieldGenerator();
+  ~RepeatedFieldGenerator() override = default;
 
   RepeatedFieldGenerator(const RepeatedFieldGenerator&) = delete;
   RepeatedFieldGenerator& operator=(const RepeatedFieldGenerator&) = delete;
 
-  virtual void GenerateFieldStorageDeclaration(
-      io::Printer* printer) const override;
-  virtual void GeneratePropertyDeclaration(io::Printer* printer) const override;
+  void GenerateFieldStorageDeclaration(io::Printer* printer) const override;
+  void GeneratePropertyDeclaration(io::Printer* printer) const override;
 
-  virtual void GeneratePropertyImplementation(
-      io::Printer* printer) const override;
+  void GeneratePropertyImplementation(io::Printer* printer) const override;
 
-  virtual bool RuntimeUsesHasBit(void) const override;
+  bool RuntimeUsesHasBit() const override;
 
  protected:
   explicit RepeatedFieldGenerator(const FieldDescriptor* descriptor);
-  virtual void FinishInitialization(void) override;
+  void FinishInitialization() override;
 };
 
 // Convenience class which constructs FieldGenerators for a Descriptor.
 class FieldGeneratorMap {
  public:
   explicit FieldGeneratorMap(const Descriptor* descriptor);
-  ~FieldGeneratorMap();
+  ~FieldGeneratorMap() = default;
 
   FieldGeneratorMap(const FieldGeneratorMap&) = delete;
   FieldGeneratorMap& operator=(const FieldGeneratorMap&) = delete;
@@ -174,12 +172,12 @@ class FieldGeneratorMap {
   const FieldGenerator& get_extension(int index) const;
 
   // Assigns the has bits and returns the number of bits needed.
-  int CalculateHasBits(void);
+  int CalculateHasBits();
 
   void SetOneofIndexBase(int index_base);
 
   // Check if any field of this message has a non zero default.
-  bool DoesAnyFieldHaveNonZeroDefault(void) const;
+  bool DoesAnyFieldHaveNonZeroDefault() const;
 
  private:
   const Descriptor* descriptor_;

src/google/protobuf/compiler/objectivec/file.cc

@@ -32,13 +32,18 @@
 
 #include <algorithm>
 #include <iostream>
+#include <iterator>
+#include <map>
+#include <set>
 #include <sstream>
+#include <string>
+#include <vector>
 
-#include "absl/strings/str_cat.h"
 #include "google/protobuf/compiler/code_generator.h"
+#include "absl/container/flat_hash_set.h"
+#include "absl/strings/str_cat.h"
 #include "google/protobuf/compiler/objectivec/enum.h"
 #include "google/protobuf/compiler/objectivec/extension.h"
-#include "google/protobuf/compiler/objectivec/helpers.h"
 #include "google/protobuf/compiler/objectivec/import_writer.h"
 #include "google/protobuf/compiler/objectivec/message.h"
 #include "google/protobuf/compiler/objectivec/names.h"
@@ -137,19 +142,17 @@ struct FileDescriptorsOrderedByName {
 
 }  // namespace
 
-FileGenerator::CommonState::CommonState() {}
-
 const FileGenerator::CommonState::MinDepsEntry&
 FileGenerator::CommonState::CollectMinimalFileDepsContainingExtensionsInternal(
     const FileDescriptor* file) {
-  auto it = deps_info_cache_.find(file);
-  if (it != deps_info_cache_.end()) {
+  auto it = deps_info_cache.find(file);
+  if (it != deps_info_cache.end()) {
     return it->second;
   }
 
-  std::unordered_set<const FileDescriptor*> min_deps_collector;
-  std::unordered_set<const FileDescriptor*> covered_deps_collector;
-  std::unordered_set<const FileDescriptor*> to_prune;
+  absl::flat_hash_set<const FileDescriptor*> min_deps_collector;
+  absl::flat_hash_set<const FileDescriptor*> covered_deps_collector;
+  absl::flat_hash_set<const FileDescriptor*> to_prune;
   for (int i = 0; i < file->dependency_count(); i++) {
     const FileDescriptor* dep = file->dependency(i);
     MinDepsEntry dep_info =
@@ -182,19 +185,19 @@ FileGenerator::CommonState::CollectMinimalFileDepsContainingExtensionsInternal(
   // Fast path: if nothing to prune or there was only one dep, the prune work is
   // a waste, skip it.
   if (to_prune.empty() || file->dependency_count() == 1) {
-    return deps_info_cache_
+    return deps_info_cache
         .insert(
             {file, {file_has_exts, min_deps_collector, covered_deps_collector}})
         .first->second;
   }
 
-  std::unordered_set<const FileDescriptor*> min_deps;
+  absl::flat_hash_set<const FileDescriptor*> min_deps;
   std::copy_if(min_deps_collector.begin(), min_deps_collector.end(),
                std::inserter(min_deps, min_deps.end()),
                [&](const FileDescriptor* value) {
                  return to_prune.find(value) == to_prune.end();
                });
-  return deps_info_cache_
+  return deps_info_cache
       .insert({file, {file_has_exts, min_deps, covered_deps_collector}})
       .first->second;
 }
@@ -211,7 +214,7 @@ FileGenerator::CommonState::CollectMinimalFileDepsContainingExtensionsInternal(
 const std::vector<const FileDescriptor*>
 FileGenerator::CommonState::CollectMinimalFileDepsContainingExtensions(
     const FileDescriptor* file) {
-  std::unordered_set<const FileDescriptor*> min_deps =
+  absl::flat_hash_set<const FileDescriptor*> min_deps =
       CollectMinimalFileDepsContainingExtensionsInternal(file).min_deps;
   // Sort the list since pointer order isn't stable across runs.
   std::vector<const FileDescriptor*> result(min_deps.begin(), min_deps.end());
@@ -243,8 +246,6 @@ FileGenerator::FileGenerator(const FileDescriptor* file,
   }
 }
 
-FileGenerator::~FileGenerator() {}
-
 void FileGenerator::GenerateHeader(io::Printer* printer) {
   std::vector<std::string> headers;
   // Generated files bundled with the library get minimal imports, everything

src/google/protobuf/compiler/objectivec/file.h

@@ -31,11 +31,15 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_FILE_H__
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_FILE_H__
 
+#include <memory>
 #include <string>
-#include <unordered_map>
-#include <unordered_set>
 #include <vector>
 
+#include "absl/container/flat_hash_map.h"
+#include "absl/container/flat_hash_set.h"
+#include "google/protobuf/compiler/objectivec/enum.h"
+#include "google/protobuf/compiler/objectivec/extension.h"
+#include "google/protobuf/compiler/objectivec/message.h"
 #include "google/protobuf/compiler/objectivec/options.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/io/printer.h"
@@ -45,16 +49,12 @@ namespace protobuf {
 namespace compiler {
 namespace objectivec {
 
-class EnumGenerator;
-class ExtensionGenerator;
-class MessageGenerator;
-
 class FileGenerator {
  public:
   // Wrapper for some common state that is shared between file generations to
   // improve performance when more than one file is generated at a time.
   struct CommonState {
-    CommonState();
+    CommonState() = default;
 
     const std::vector<const FileDescriptor*>
     CollectMinimalFileDepsContainingExtensions(const FileDescriptor* file);
@@ -62,20 +62,20 @@ class FileGenerator {
    private:
     struct MinDepsEntry {
       bool has_extensions;
-      std::unordered_set<const FileDescriptor*> min_deps;
+      absl::flat_hash_set<const FileDescriptor*> min_deps;
       // `covered_deps` are the transtive deps of `min_deps_w_exts` that also
       // have extensions.
-      std::unordered_set<const FileDescriptor*> covered_deps;
+      absl::flat_hash_set<const FileDescriptor*> covered_deps;
     };
     const MinDepsEntry& CollectMinimalFileDepsContainingExtensionsInternal(
         const FileDescriptor* file);
-    std::unordered_map<const FileDescriptor*, MinDepsEntry> deps_info_cache_;
+    absl::flat_hash_map<const FileDescriptor*, MinDepsEntry> deps_info_cache;
   };
 
   FileGenerator(const FileDescriptor* file,
                 const GenerationOptions& generation_options,
                 CommonState& common_state);
-  ~FileGenerator();
+  ~FileGenerator() = default;
 
   FileGenerator(const FileGenerator&) = delete;
   FileGenerator& operator=(const FileGenerator&) = delete;

src/google/protobuf/compiler/objectivec/generator.cc

@@ -32,14 +32,16 @@
 
 #include <fstream>
 #include <iostream>
+#include <memory>
 #include <string>
-#include <unordered_set>
+#include <utility>
+#include <vector>
 
+#include "absl/container/flat_hash_set.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/str_split.h"
 #include "absl/strings/strip.h"
 #include "google/protobuf/compiler/objectivec/file.h"
-#include "google/protobuf/compiler/objectivec/helpers.h"
 #include "google/protobuf/compiler/objectivec/names.h"
 #include "google/protobuf/io/printer.h"
 #include "google/protobuf/io/zero_copy_stream.h"
@@ -71,10 +73,6 @@ bool StringToBool(const std::string& value, bool* result) {
 
 }  // namespace
 
-ObjectiveCGenerator::ObjectiveCGenerator() {}
-
-ObjectiveCGenerator::~ObjectiveCGenerator() {}
-
 bool ObjectiveCGenerator::HasGenerateAll() const { return true; }
 
 bool ObjectiveCGenerator::Generate(const FileDescriptor* file,
@@ -127,7 +125,7 @@ bool ObjectiveCGenerator::GenerateAll(
       // exclude from the package prefix validations (expected_prefixes_path).
       // This is provided as an "out", to skip some files being checked.
       for (absl::string_view split_piece :
-           absl::StrSplit(options[i].second, ";", absl::SkipEmpty())) {
+           absl::StrSplit(options[i].second, ';', absl::SkipEmpty())) {
         validation_options.expected_prefixes_suppressions.push_back(
             std::string(split_piece));
       }
@@ -261,9 +259,9 @@ bool ObjectiveCGenerator::GenerateAll(
 
   // These are not official generation options and could be removed/changed in
   // the future and doing that won't count as a breaking change.
-  bool headers_only = getenv("GPB_OBJC_HEADERS_ONLY") != NULL;
-  std::unordered_set<std::string> skip_impls;
-  if (getenv("GPB_OBJC_SKIP_IMPLS_FILE") != NULL) {
+  bool headers_only = getenv("GPB_OBJC_HEADERS_ONLY") != nullptr;
+  absl::flat_hash_set<std::string> skip_impls;
+  if (getenv("GPB_OBJC_SKIP_IMPLS_FILE") != nullptr) {
     std::ifstream skip_file(getenv("GPB_OBJC_SKIP_IMPLS_FILE"));
     if (skip_file.is_open()) {
       std::string line;

src/google/protobuf/compiler/objectivec/generator.h

@@ -34,6 +34,7 @@
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_GENERATOR_H__
 
 #include <string>
+#include <vector>
 
 #include "google/protobuf/compiler/code_generator.h"
 #include "google/protobuf/descriptor.h"
@@ -52,8 +53,8 @@ namespace objectivec {
 // CodeGenerator with the CommandLineInterface in your main() function.
 class PROTOC_EXPORT ObjectiveCGenerator : public CodeGenerator {
  public:
-  ObjectiveCGenerator();
-  ~ObjectiveCGenerator();
+  ObjectiveCGenerator() = default;
+  ~ObjectiveCGenerator() override = default;
 
   ObjectiveCGenerator(const ObjectiveCGenerator&) = delete;
   ObjectiveCGenerator& operator=(const ObjectiveCGenerator&) = delete;

src/google/protobuf/compiler/objectivec/helpers.cc

@@ -30,15 +30,18 @@
 
 #include "google/protobuf/compiler/objectivec/helpers.h"
 
+#include <string>
+#include <vector>
+
+#include "google/protobuf/compiler/code_generator.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/escaping.h"
-#include "absl/strings/str_split.h"
+#include "absl/strings/match.h"
 #include "absl/strings/str_replace.h"
-#include "google/protobuf/compiler/code_generator.h"
+#include "absl/strings/str_split.h"
 #include "google/protobuf/compiler/objectivec/names.h"
-#include "google/protobuf/io/printer.h"
-#include "google/protobuf/io/zero_copy_stream_impl.h"
-#include "google/protobuf/stubs/strutil.h"
+#include "google/protobuf/io/strtod.h"
+#include "google/protobuf/stubs/common.h"
 
 // NOTE: src/google/protobuf/compiler/plugin.cc makes use of cerr for some
 // error cases, so it seems to be ok to use as a back door for errors.
@@ -91,9 +94,9 @@ std::string HandleExtremeFloatingPoint(std::string val, bool add_float_suffix) {
     return "-INFINITY";
   } else {
     // float strings with ., e or E need to have f appended
-    if (add_float_suffix && (val.find('.') != std::string::npos ||
-                             val.find('e') != std::string::npos ||
-                             val.find('E') != std::string::npos)) {
+    if (add_float_suffix &&
+        (absl::StrContains(val, '.') || absl::StrContains(val, 'e') ||
+         absl::StrContains(val, 'E'))) {
       val += "f";
     }
     return val;
@@ -263,10 +266,10 @@ std::string DefaultValue(const FieldDescriptor* field) {
       return absl::StrCat(field->default_value_uint64()) + "ULL";
     case FieldDescriptor::CPPTYPE_DOUBLE:
       return HandleExtremeFloatingPoint(
-          SimpleDtoa(field->default_value_double()), false);
+          io::SimpleDtoa(field->default_value_double()), false);
     case FieldDescriptor::CPPTYPE_FLOAT:
       return HandleExtremeFloatingPoint(
-          SimpleFtoa(field->default_value_float()), true);
+          io::SimpleFtoa(field->default_value_float()), true);
     case FieldDescriptor::CPPTYPE_BOOL:
       return field->default_value_bool() ? "YES" : "NO";
     case FieldDescriptor::CPPTYPE_STRING: {
@@ -339,7 +342,7 @@ std::string BuildCommentsString(const SourceLocation& location,
                                     ? location.trailing_comments
                                     : location.leading_comments;
   std::vector<std::string> lines;
-  lines = absl::StrSplit(comments, "\n", absl::AllowEmpty());
+  lines = absl::StrSplit(comments, '\n', absl::AllowEmpty());
   while (!lines.empty() && lines.back().empty()) {
     lines.pop_back();
   }

src/google/protobuf/compiler/objectivec/helpers.h

@@ -122,7 +122,7 @@ std::string BuildCommentsString(const SourceLocation& location,
 
 template <class TDescriptor>
 std::string GetOptionalDeprecatedAttribute(const TDescriptor* descriptor,
-                                           const FileDescriptor* file = NULL,
+                                           const FileDescriptor* file = nullptr,
                                            bool preSpace = true,
                                            bool postNewline = false) {
   bool isDeprecated = descriptor->options().deprecated();

src/google/protobuf/compiler/objectivec/import_writer.cc

@@ -30,7 +30,14 @@
 
 #include "google/protobuf/compiler/objectivec/import_writer.h"
 
+#include <iostream>
+#include <map>
+#include <ostream>
+#include <string>
+#include <vector>
+
 #include "absl/strings/ascii.h"
+#include "absl/strings/match.h"
 #include "google/protobuf/compiler/objectivec/line_consumer.h"
 #include "google/protobuf/compiler/objectivec/names.h"
 #include "google/protobuf/io/printer.h"
@@ -47,18 +54,17 @@ namespace {
 
 class ProtoFrameworkCollector : public LineConsumer {
  public:
-  ProtoFrameworkCollector(
+  explicit ProtoFrameworkCollector(
       std::map<std::string, std::string>* inout_proto_file_to_framework_name)
       : map_(inout_proto_file_to_framework_name) {}
 
-  virtual bool ConsumeLine(const absl::string_view& line,
-                           std::string* out_error) override;
+  bool ConsumeLine(absl::string_view line, std::string* out_error) override;
 
  private:
   std::map<std::string, std::string>* map_;
 };
 
-bool ProtoFrameworkCollector::ConsumeLine(const absl::string_view& line,
+bool ProtoFrameworkCollector::ConsumeLine(absl::string_view line,
                                           std::string* out_error) {
   int offset = line.find(':');
   if (offset == absl::string_view::npos) {
@@ -93,7 +99,7 @@ bool ProtoFrameworkCollector::ConsumeLine(const absl::string_view& line,
         std::cerr.flush();
       }
 
-      if (proto_file.find(' ') != absl::string_view::npos) {
+      if (absl::StrContains(proto_file, ' ')) {
         std::cerr << "note: framework mapping file had a proto file with a "
                      "space in, hopefully that isn't a missing comma: '"
                   << std::string(proto_file) << "'" << std::endl;
@@ -122,8 +128,6 @@ ImportWriter::ImportWriter(
       include_wkt_imports_(include_wkt_imports),
       need_to_parse_mapping_file_(true) {}
 
-ImportWriter::~ImportWriter() {}
-
 void ImportWriter::AddFile(const FileDescriptor* file,
                            const std::string& header_extension) {
   if (IsProtobufLibraryBundledProtoFile(file)) {

src/google/protobuf/compiler/objectivec/import_writer.h

@@ -31,6 +31,7 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_IMPORT_WRITER_H__
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_IMPORT_WRITER_H__
 
+#include <map>
 #include <string>
 #include <vector>
 
@@ -50,7 +51,7 @@ class ImportWriter {
                const std::string& named_framework_to_proto_path_mappings_path,
                const std::string& runtime_import_prefix,
                bool include_wkt_imports);
-  ~ImportWriter();
+  ~ImportWriter() = default;
 
   void AddFile(const FileDescriptor* file, const std::string& header_extension);
   void Print(io::Printer* printer) const;

src/google/protobuf/compiler/objectivec/line_consumer.cc

@@ -39,15 +39,18 @@
 #include <fstream>
 #include <iostream>
 #include <sstream>
+#include <string>
 #include <vector>
 
 #include "absl/strings/ascii.h"
 #include "absl/strings/str_cat.h"
-#include "absl/strings/str_split.h"
 #include "google/protobuf/compiler/objectivec/line_consumer.h"
-#include "google/protobuf/io/io_win32.h"
 #include "google/protobuf/io/zero_copy_stream_impl.h"
 
+#ifdef _WIN32
+#include "google/protobuf/io/io_win32.h"
+#endif
+
 // NOTE: src/google/protobuf/compiler/plugin.cc makes use of cerr for some
 // error cases, so it seems to be ok to use as a back door for errors.
 
@@ -91,7 +94,7 @@ void RemoveComment(absl::string_view* input) {
 
 class Parser {
  public:
-  Parser(LineConsumer* line_consumer)
+  explicit Parser(LineConsumer* line_consumer)
       : line_consumer_(line_consumer), line_(0) {}
 
   // Feeds in some input, parse what it can, returning success/failure. Calling
@@ -156,18 +159,8 @@ bool Parser::Finish(std::string* out_error) {
   return true;
 }
 
-std::string FullErrorString(const std::string& name, int line_num,
-                            const std::string& msg) {
-  return std::string("error: ") + name + " Line " + absl::StrCat(line_num) +
-         ", " + msg;
-}
-
 }  // namespace
 
-LineConsumer::LineConsumer() {}
-
-LineConsumer::~LineConsumer() {}
-
 bool ParseSimpleFile(const std::string& path, LineConsumer* line_consumer,
                      std::string* out_error) {
   int fd;
@@ -175,8 +168,8 @@ bool ParseSimpleFile(const std::string& path, LineConsumer* line_consumer,
     fd = posix::open(path.c_str(), O_RDONLY);
   } while (fd < 0 && errno == EINTR);
   if (fd < 0) {
-    *out_error = std::string("error: Unable to open \"") + path + "\", " +
-                 strerror(errno);
+    *out_error =
+        absl::StrCat("error: Unable to open \"", path, "\", ", strerror(errno));
     return false;
   }
   io::FileInputStream file_stream(fd);
@@ -200,13 +193,14 @@ bool ParseSimpleStream(io::ZeroCopyInputStream& input_stream,
     if (!parser.ParseChunk(
             absl::string_view(static_cast<const char*>(buf), buf_len),
             &local_error)) {
-      *out_error =
-          FullErrorString(stream_name, parser.last_line(), local_error);
+      *out_error = absl::StrCat("error: ", stream_name, " Line ",
+                                parser.last_line(), ", ", local_error);
       return false;
     }
   }
   if (!parser.Finish(&local_error)) {
-    *out_error = FullErrorString(stream_name, parser.last_line(), local_error);
+    *out_error = absl::StrCat("error: ", stream_name, " Line ",
+                              parser.last_line(), ", ", local_error);
     return false;
   }
   return true;

src/google/protobuf/compiler/objectivec/line_consumer.h

@@ -50,10 +50,9 @@ namespace objectivec {
 // Helper for parsing simple files.
 class PROTOC_EXPORT LineConsumer {
  public:
-  LineConsumer();
-  virtual ~LineConsumer();
-  virtual bool ConsumeLine(const absl::string_view& line,
-                           std::string* out_error) = 0;
+  LineConsumer() = default;
+  virtual ~LineConsumer() = default;
+  virtual bool ConsumeLine(absl::string_view line, std::string* out_error) = 0;
 };
 
 bool PROTOC_EXPORT ParseSimpleFile(const std::string& path,

src/google/protobuf/compiler/objectivec/line_consumer_unittest.cc

@@ -30,8 +30,12 @@
 
 #include "google/protobuf/compiler/objectivec/line_consumer.h"
 
-#include <gtest/gtest.h>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
 
+#include <gtest/gtest.h>
 #include "absl/strings/str_cat.h"
 #include "google/protobuf/io/zero_copy_stream_impl_lite.h"
 
@@ -48,8 +52,7 @@ class TestLineCollector : public LineConsumer {
                              bool skip_msg = false)
       : lines_(inout_lines), reject_(reject_line), skip_msg_(skip_msg) {}
 
-  bool ConsumeLine(const absl::string_view& line,
-                   std::string* out_error) override {
+  bool ConsumeLine(absl::string_view line, std::string* out_error) override {
     if (reject_ && *reject_ == line) {
       if (!skip_msg_) {
         *out_error = std::string("Rejected '") + *reject_ + "'";

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

@@ -31,11 +31,13 @@
 #include "google/protobuf/compiler/objectivec/map_field.h"
 
 #include <map>
+#include <set>
 #include <string>
+#include <vector>
 
+#include "absl/strings/match.h"
 #include "google/protobuf/compiler/objectivec/helpers.h"
 #include "google/protobuf/compiler/objectivec/names.h"
-#include "google/protobuf/io/printer.h"
 
 namespace google {
 namespace protobuf {
@@ -78,7 +80,7 @@ const char* MapEntryTypeName(const FieldDescriptor* descriptor, bool isKey) {
   // Some compilers report reaching end of function even though all cases of
   // the enum are handed in the switch.
   GOOGLE_LOG(FATAL) << "Can't get here.";
-  return NULL;
+  return nullptr;
 }
 
 }  // namespace
@@ -99,18 +101,17 @@ MapFieldGenerator::MapFieldGenerator(const FieldDescriptor* descriptor)
   std::vector<std::string> field_flags;
   field_flags.push_back("GPBFieldMapKey" + GetCapitalizedType(key_descriptor));
   // Pull over the current text format custom name values that was calculated.
-  if (variables_["fieldflags"].find("GPBFieldTextFormatNameCustom") !=
-      std::string::npos) {
+  if (absl::StrContains(variables_["fieldflags"],
+                        "GPBFieldTextFormatNameCustom")) {
     field_flags.push_back("GPBFieldTextFormatNameCustom");
   }
   // Pull over some info from the value's flags.
   const std::string& value_field_flags =
       value_field_generator_->variable("fieldflags");
-  if (value_field_flags.find("GPBFieldHasDefaultValue") != std::string::npos) {
+  if (absl::StrContains(value_field_flags, "GPBFieldHasDefaultValue")) {
     field_flags.push_back("GPBFieldHasDefaultValue");
   }
-  if (value_field_flags.find("GPBFieldHasEnumDescriptor") !=
-      std::string::npos) {
+  if (absl::StrContains(value_field_flags, "GPBFieldHasEnumDescriptor")) {
     field_flags.push_back("GPBFieldHasEnumDescriptor");
   }
 
@@ -146,9 +147,7 @@ MapFieldGenerator::MapFieldGenerator(const FieldDescriptor* descriptor)
       value_field_generator_->variable("dataTypeSpecific_value");
 }
 
-MapFieldGenerator::~MapFieldGenerator() {}
-
-void MapFieldGenerator::FinishInitialization(void) {
+void MapFieldGenerator::FinishInitialization() {
   RepeatedFieldGenerator::FinishInitialization();
   // Use the array_comment support in RepeatedFieldGenerator to output what the
   // values in the map are.

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

@@ -32,6 +32,8 @@
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_MAP_FIELD_H__
 
 #include <map>
+#include <memory>
+#include <set>
 #include <string>
 
 #include "google/protobuf/compiler/objectivec/field.h"
@@ -45,19 +47,18 @@ class MapFieldGenerator : public RepeatedFieldGenerator {
   friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
 
  public:
-  virtual void FinishInitialization(void) override;
+  void FinishInitialization() override;
 
   MapFieldGenerator(const MapFieldGenerator&) = delete;
   MapFieldGenerator& operator=(const MapFieldGenerator&) = delete;
 
  protected:
   explicit MapFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~MapFieldGenerator();
+  ~MapFieldGenerator() override = default;
 
-  virtual void DetermineObjectiveCClassDefinitions(
+  void DetermineObjectiveCClassDefinitions(
       std::set<std::string>* fwd_decls) const override;
-  virtual void DetermineForwardDeclarations(
-      std::set<std::string>* fwd_decls,
+  void DetermineForwardDeclarations(std::set<std::string>* fwd_decls,
                                     bool include_external_types) const override;
 
  private:

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

@@ -32,7 +32,12 @@
 
 #include <algorithm>
 #include <iostream>
+#include <map>
+#include <memory>
+#include <set>
 #include <sstream>
+#include <string>
+#include <vector>
 
 #include "absl/strings/escaping.h"
 #include "absl/strings/str_cat.h"
@@ -206,8 +211,6 @@ MessageGenerator::MessageGenerator(const std::string& root_classname,
   }
 }
 
-MessageGenerator::~MessageGenerator() {}
-
 void MessageGenerator::GenerateStaticVariablesInitialization(
     io::Printer* printer) {
   for (const auto& generator : extension_generators_) {
@@ -253,7 +256,7 @@ void MessageGenerator::DetermineObjectiveCClassDefinitions(
   }
 
   const Descriptor* containing_descriptor = descriptor_->containing_type();
-  if (containing_descriptor != NULL) {
+  if (containing_descriptor != nullptr) {
     std::string containing_class = ClassName(containing_descriptor);
     fwd_decls->insert(ObjCClassDeclaration(containing_class));
   }
@@ -598,7 +601,7 @@ void MessageGenerator::GenerateSource(io::Printer* printer) {
           "                                    count:(uint32_t)(sizeof(ranges) / sizeof(GPBExtensionRange))];\n");
       // clang-format on
     }
-    if (descriptor_->containing_type() != NULL) {
+    if (descriptor_->containing_type() != nullptr) {
       std::string containing_class = ClassName(descriptor_->containing_type());
       std::string parent_class_ref = ObjCClass(containing_class);
       printer->Print(

src/google/protobuf/compiler/objectivec/message.h

@@ -31,6 +31,7 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_MESSAGE_H__
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_MESSAGE_H__
 
+#include <memory>
 #include <set>
 #include <string>
 #include <vector>
@@ -52,7 +53,7 @@ class MessageGenerator {
  public:
   MessageGenerator(const std::string& root_classname,
                    const Descriptor* descriptor);
-  ~MessageGenerator();
+  ~MessageGenerator() = default;
 
   MessageGenerator(const MessageGenerator&) = delete;
   MessageGenerator& operator=(const MessageGenerator&) = delete;

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

@@ -31,11 +31,11 @@
 #include "google/protobuf/compiler/objectivec/message_field.h"
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "google/protobuf/compiler/objectivec/helpers.h"
 #include "google/protobuf/compiler/objectivec/names.h"
-#include "google/protobuf/io/printer.h"
 
 namespace google {
 namespace protobuf {
@@ -64,8 +64,6 @@ MessageFieldGenerator::MessageFieldGenerator(const FieldDescriptor* descriptor)
   SetMessageVariables(descriptor, &variables_);
 }
 
-MessageFieldGenerator::~MessageFieldGenerator() {}
-
 void MessageFieldGenerator::DetermineForwardDeclarations(
     std::set<std::string>* fwd_decls, bool include_external_types) const {
   ObjCObjFieldGenerator::DetermineForwardDeclarations(fwd_decls,
@@ -95,8 +93,6 @@ RepeatedMessageFieldGenerator::RepeatedMessageFieldGenerator(
       "NSMutableArray<" + variables_["storage_type"] + "*>";
 }
 
-RepeatedMessageFieldGenerator::~RepeatedMessageFieldGenerator() {}
-
 void RepeatedMessageFieldGenerator::DetermineForwardDeclarations(
     std::set<std::string>* fwd_decls, bool include_external_types) const {
   RepeatedFieldGenerator::DetermineForwardDeclarations(fwd_decls,

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

@@ -32,6 +32,7 @@
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_MESSAGE_FIELD_H__
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "google/protobuf/compiler/objectivec/field.h"
@@ -46,17 +47,15 @@ class MessageFieldGenerator : public ObjCObjFieldGenerator {
 
  protected:
   explicit MessageFieldGenerator(const FieldDescriptor* descriptor);
+  ~MessageFieldGenerator() override = default;
 
   MessageFieldGenerator(const MessageFieldGenerator&) = delete;
   MessageFieldGenerator& operator=(const MessageFieldGenerator&) = delete;
 
-  virtual ~MessageFieldGenerator();
-
  public:
-  virtual void DetermineForwardDeclarations(
-      std::set<std::string>* fwd_decls,
+  void DetermineForwardDeclarations(std::set<std::string>* fwd_decls,
                                     bool include_external_types) const override;
-  virtual void DetermineObjectiveCClassDefinitions(
+  void DetermineObjectiveCClassDefinitions(
       std::set<std::string>* fwd_decls) const override;
 };
 
@@ -65,17 +64,16 @@ class RepeatedMessageFieldGenerator : public RepeatedFieldGenerator {
 
  protected:
   explicit RepeatedMessageFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~RepeatedMessageFieldGenerator();
+  ~RepeatedMessageFieldGenerator() override = default;
 
   RepeatedMessageFieldGenerator(const RepeatedMessageFieldGenerator&) = delete;
   RepeatedMessageFieldGenerator operator=(
       const RepeatedMessageFieldGenerator&) = delete;
 
  public:
-  virtual void DetermineForwardDeclarations(
-      std::set<std::string>* fwd_decls,
+  void DetermineForwardDeclarations(std::set<std::string>* fwd_decls,
                                     bool include_external_types) const override;
-  virtual void DetermineObjectiveCClassDefinitions(
+  void DetermineObjectiveCClassDefinitions(
       std::set<std::string>* fwd_decls) const override;
 };
 

src/google/protobuf/compiler/objectivec/names.cc

@@ -30,20 +30,24 @@
 
 #include "google/protobuf/compiler/objectivec/names.h"
 
+#include <algorithm>
 #include <climits>
 #include <fstream>
 #include <iostream>
+#include <map>
+#include <ostream>
 #include <sstream>
-#include <unordered_set>
+#include <string>
 #include <vector>
 
+#include "google/protobuf/compiler/code_generator.h"
+#include "absl/container/flat_hash_set.h"
 #include "absl/strings/ascii.h"
+#include "absl/strings/str_cat.h"
 #include "absl/strings/str_split.h"
-#include "google/protobuf/compiler/code_generator.h"
 #include "google/protobuf/compiler/objectivec/line_consumer.h"
 #include "google/protobuf/compiler/objectivec/nsobject_methods.h"
 #include "google/protobuf/descriptor.pb.h"
-#include "google/protobuf/io/zero_copy_stream_impl.h"
 
 // NOTE: src/google/protobuf/compiler/plugin.cc makes use of cerr for some
 // error cases, so it seems to be ok to use as a back door for errors.
@@ -65,17 +69,16 @@ bool BoolFromEnvVar(const char* env_var, bool default_value) {
 
 class SimpleLineCollector : public LineConsumer {
  public:
-  explicit SimpleLineCollector(std::unordered_set<std::string>* inout_set)
+  explicit SimpleLineCollector(absl::flat_hash_set<std::string>* inout_set)
       : set_(inout_set) {}
 
-  virtual bool ConsumeLine(const absl::string_view& line,
-                           std::string* out_error) override {
+  bool ConsumeLine(absl::string_view line, std::string* out_error) override {
     set_->insert(std::string(line));
     return true;
   }
 
  private:
-  std::unordered_set<std::string>* set_;
+  absl::flat_hash_set<std::string>* set_;
 };
 
 class PackageToPrefixesCollector : public LineConsumer {
@@ -85,8 +88,7 @@ class PackageToPrefixesCollector : public LineConsumer {
       std::map<std::string, std::string>* inout_package_to_prefix_map)
       : usage_(usage), prefix_map_(inout_package_to_prefix_map) {}
 
-  virtual bool ConsumeLine(const absl::string_view& line,
-                           std::string* out_error) override;
+  bool ConsumeLine(absl::string_view line, std::string* out_error) override;
 
  private:
   const std::string usage_;
@@ -131,7 +133,7 @@ class PrefixModeStorage {
   std::string package_to_prefix_mappings_path_;
   std::string exception_path_;
   std::string forced_prefix_;
-  std::unordered_set<std::string> exceptions_;
+  absl::flat_hash_set<std::string> exceptions_;
 };
 
 PrefixModeStorage::PrefixModeStorage() {
@@ -181,7 +183,7 @@ std::string PrefixModeStorage::prefix_from_proto_package_mappings(
   const std::string package = file->package();
   // For files without packages, the can be registered as "no_package:PATH",
   // allowing the expected prefixes file.
-  static const std::string no_package_prefix("no_package:");
+  const std::string no_package_prefix("no_package:");
   const std::string lookup_key =
       package.empty() ? no_package_prefix + file->name() : package;
 
@@ -220,7 +222,7 @@ bool PrefixModeStorage::is_package_exempted(const std::string& package) {
   return exceptions_.count(package) != 0;
 }
 
-PrefixModeStorage g_prefix_mode;
+PrefixModeStorage& g_prefix_mode = *new PrefixModeStorage();
 
 }  // namespace
 
@@ -258,19 +260,19 @@ void SetForcedPackagePrefix(const std::string& prefix) {
 
 namespace {
 
-std::unordered_set<std::string> MakeWordsMap(const char* const words[],
-                                             size_t num_words) {
-  std::unordered_set<std::string> result;
-  for (int i = 0; i < num_words; i++) {
-    result.insert(words[i]);
-  }
-  return result;
-}
-
 const char* const kUpperSegmentsList[] = {"url", "http", "https"};
 
-std::unordered_set<std::string> kUpperSegments =
-    MakeWordsMap(kUpperSegmentsList, ABSL_ARRAYSIZE(kUpperSegmentsList));
+const absl::flat_hash_set<absl::string_view>& UpperSegments() {
+  static const auto* words = [] {
+    auto* words = new absl::flat_hash_set<absl::string_view>();
+
+    for (const auto word : kUpperSegmentsList) {
+      words->emplace(word);
+    }
+    return words;
+  }();
+  return *words;
+}
 
 // Internal helper for name handing.
 // Do not expose this outside of helpers, stick to having functions for specific
@@ -318,19 +320,15 @@ std::string UnderscoresToCamelCase(const std::string& input,
 
   std::string result;
   bool first_segment_forces_upper = false;
-  for (std::vector<std::string>::iterator i = values.begin(); i != values.end();
-       ++i) {
-    std::string value = *i;
-    bool all_upper = (kUpperSegments.count(value) > 0);
+  for (auto& value : values) {
+    bool all_upper = (UpperSegments().count(value) > 0);
     if (all_upper && (result.length() == 0)) {
       first_segment_forces_upper = true;
     }
-    for (int j = 0; j < value.length(); j++) {
-      if (j == 0 || all_upper) {
-        value[j] = absl::ascii_toupper(value[j]);
+    if (all_upper) {
+      absl::AsciiStrToUpper(&value);
     } else {
-        // Nothing, already in lower.
-      }
+      value[0] = absl::ascii_toupper(value[0]);
     }
     result += value;
   }
@@ -525,6 +523,30 @@ const char* const kReservedWordList[] = {
     "TimeRecord",
 };
 
+const absl::flat_hash_set<absl::string_view>& ReservedWords() {
+  static const auto* words = [] {
+    auto* words = new absl::flat_hash_set<absl::string_view>();
+
+    for (const auto word : kReservedWordList) {
+      words->emplace(word);
+    }
+    return words;
+  }();
+  return *words;
+}
+
+const absl::flat_hash_set<absl::string_view>& NSObjectMethods() {
+  static const auto* words = [] {
+    auto* words = new absl::flat_hash_set<absl::string_view>();
+
+    for (const auto word : kNSObjectMethodsList) {
+      words->emplace(word);
+    }
+    return words;
+  }();
+  return *words;
+}
+
 // returns true is input starts with __ or _[A-Z] which are reserved identifiers
 // in C/ C++. All calls should go through UnderscoresToCamelCase before getting
 // here but this verifies and allows for future expansion if we decide to
@@ -545,10 +567,6 @@ std::string SanitizeNameForObjC(const std::string& prefix,
                                 const std::string& input,
                                 const std::string& extension,
                                 std::string* out_suffix_added) {
-  static const std::unordered_set<std::string> kReservedWords =
-      MakeWordsMap(kReservedWordList, ABSL_ARRAYSIZE(kReservedWordList));
-  static const std::unordered_set<std::string> kNSObjectMethods =
-      MakeWordsMap(kNSObjectMethodsList, ABSL_ARRAYSIZE(kNSObjectMethodsList));
   std::string sanitized;
   // We add the prefix in the cases where the string is missing a prefix.
   // We define "missing a prefix" as where 'input':
@@ -566,8 +584,8 @@ std::string SanitizeNameForObjC(const std::string& prefix,
     sanitized = prefix + input;
   }
   if (IsReservedCIdentifier(sanitized) ||
-      (kReservedWords.count(sanitized) > 0) ||
-      (kNSObjectMethods.count(sanitized) > 0)) {
+      (ReservedWords().count(sanitized) > 0) ||
+      (NSObjectMethods().count(sanitized) > 0)) {
     if (out_suffix_added) *out_suffix_added = extension;
     return sanitized + extension;
   }
@@ -604,14 +622,13 @@ void PathSplit(const std::string& path, std::string* directory,
 }
 
 bool IsSpecialNamePrefix(const std::string& name,
-                         const std::string* special_names, size_t count) {
-  for (size_t i = 0; i < count; ++i) {
-    const size_t length = special_names[i].length();
-    if (name.compare(0, length, special_names[i]) == 0) {
+                         const std::vector<std::string>& special_names) {
+  for (const auto& special_name : special_names) {
+    const size_t length = special_name.length();
+    if (name.compare(0, length, special_name) == 0) {
       if (name.length() > length) {
-        // If name is longer than the special_names[i] that it matches
-        // the next character must be not lower case (newton vs newTon vs
-        // new_ton).
+        // If name is longer than the special_name that it matches the next
+        // character must be not lower case (newton vs newTon vs new_ton).
         return !absl::ascii_islower(name[length]);
       } else {
         return true;
@@ -635,27 +652,26 @@ void MaybeUnQuote(absl::string_view* input) {
 bool IsRetainedName(const std::string& name) {
   // List of prefixes from
   // http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/MemoryMgmt/Articles/mmRules.html
-  static const std::string retained_names[] = {"new", "alloc", "copy",
-                                               "mutableCopy"};
-  return IsSpecialNamePrefix(
-      name, retained_names, sizeof(retained_names) / sizeof(retained_names[0]));
+  static const std::vector<std::string>* retained_names =
+      new std::vector<std::string>({"new", "alloc", "copy", "mutableCopy"});
+  return IsSpecialNamePrefix(name, *retained_names);
 }
 
 bool IsInitName(const std::string& name) {
-  static const std::string init_names[] = {"init"};
-  return IsSpecialNamePrefix(name, init_names,
-                             sizeof(init_names) / sizeof(init_names[0]));
+  static const std::vector<std::string>* init_names =
+      new std::vector<std::string>({"init"});
+  return IsSpecialNamePrefix(name, *init_names);
 }
 
 bool IsCreateName(const std::string& name) {
   // List of segments from
   // https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html#//apple_ref/doc/uid/20001148-103029
-  static const std::string create_names[] = {"Create", "Copy"};
-  const size_t count = sizeof(create_names) / sizeof(create_names[0]);
+  static const std::vector<std::string>* create_names =
+      new std::vector<std::string>({"Create", "Copy"});
 
-  for (size_t i = 0; i < count; ++i) {
-    const size_t length = create_names[i].length();
-    size_t pos = name.find(create_names[i]);
+  for (const auto& create_name : *create_names) {
+    const size_t length = create_name.length();
+    size_t pos = name.find(create_name);
     if (pos != std::string::npos) {
       // The above docs don't actually call out anything about the characters
       // before the special words. So it's not clear if something like
@@ -681,7 +697,7 @@ bool IsCreateName(const std::string& name) {
 
 std::string BaseFileName(const FileDescriptor* file) {
   std::string basename;
-  PathSplit(file->name(), NULL, &basename);
+  PathSplit(file->name(), nullptr, &basename);
   return basename;
 }
 
@@ -714,7 +730,7 @@ std::string FileClassPrefix(const FileDescriptor* file) {
   // underscore at the end.
   std::string result;
   const std::vector<std::string> segments =
-      absl::StrSplit(file->package(), ".", absl::SkipEmpty());
+      absl::StrSplit(file->package(), '.', absl::SkipEmpty());
   for (const auto& segment : segments) {
     const std::string part = UnderscoresToCamelCase(segment, true);
     if (part.empty()) {
@@ -767,12 +783,12 @@ std::string FileClassName(const FileDescriptor* file) {
       UnderscoresToCamelCase(StripProto(BaseFileName(file)), true) + "Root";
   // There aren't really any reserved words that end in "Root", but playing
   // it safe and checking.
-  return SanitizeNameForObjC(prefix, name, "_RootClass", NULL);
+  return SanitizeNameForObjC(prefix, name, "_RootClass", nullptr);
 }
 
 std::string ClassNameWorker(const Descriptor* descriptor) {
   std::string name;
-  if (descriptor->containing_type() != NULL) {
+  if (descriptor->containing_type() != nullptr) {
     name = ClassNameWorker(descriptor->containing_type());
     name += "_";
   }
@@ -781,7 +797,7 @@ std::string ClassNameWorker(const Descriptor* descriptor) {
 
 std::string ClassNameWorker(const EnumDescriptor* descriptor) {
   std::string name;
-  if (descriptor->containing_type() != NULL) {
+  if (descriptor->containing_type() != nullptr) {
     name = ClassNameWorker(descriptor->containing_type());
     name += "_";
   }
@@ -789,7 +805,7 @@ std::string ClassNameWorker(const EnumDescriptor* descriptor) {
 }
 
 std::string ClassName(const Descriptor* descriptor) {
-  return ClassName(descriptor, NULL);
+  return ClassName(descriptor, nullptr);
 }
 
 std::string ClassName(const Descriptor* descriptor,
@@ -812,7 +828,7 @@ std::string EnumName(const EnumDescriptor* descriptor) {
   //    yields Fixed_Class, Fixed_Size.
   const std::string prefix = FileClassPrefix(descriptor->file());
   const std::string name = ClassNameWorker(descriptor);
-  return SanitizeNameForObjC(prefix, name, "_Enum", NULL);
+  return SanitizeNameForObjC(prefix, name, "_Enum", nullptr);
 }
 
 std::string EnumValueName(const EnumValueDescriptor* descriptor) {
@@ -828,7 +844,7 @@ std::string EnumValueName(const EnumValueDescriptor* descriptor) {
   const std::string name = class_name + "_" + value_str;
   // There aren't really any reserved words with an underscore and a leading
   // capital letter, but playing it safe and checking.
-  return SanitizeNameForObjC("", name, "_Value", NULL);
+  return SanitizeNameForObjC("", name, "_Value", nullptr);
 }
 
 std::string EnumValueShortName(const EnumValueDescriptor* descriptor) {
@@ -865,7 +881,7 @@ std::string UnCamelCaseEnumShortName(const std::string& name) {
 std::string ExtensionMethodName(const FieldDescriptor* descriptor) {
   const std::string name = NameFromFieldDescriptor(descriptor);
   const std::string result = UnderscoresToCamelCase(name, false);
-  return SanitizeNameForObjC("", result, "_Extension", NULL);
+  return SanitizeNameForObjC("", result, "_Extension", nullptr);
 }
 
 std::string FieldName(const FieldDescriptor* field) {
@@ -880,7 +896,7 @@ std::string FieldName(const FieldDescriptor* field) {
       result += "_p";
     }
   }
-  return SanitizeNameForObjC("", result, "_p", NULL);
+  return SanitizeNameForObjC("", result, "_p", nullptr);
 }
 
 std::string FieldNameCapitalized(const FieldDescriptor* field) {
@@ -960,10 +976,8 @@ const char* const ProtobufLibraryFrameworkName = "Protobuf";
 
 std::string ProtobufFrameworkImportSymbol(const std::string& framework_name) {
   // GPB_USE_[framework_name]_FRAMEWORK_IMPORTS
-  std::string result = std::string("GPB_USE_");
-  result += absl::AsciiStrToUpper(framework_name);
-  result += "_FRAMEWORK_IMPORTS";
-  return result;
+  return absl::StrCat("GPB_USE_", absl::AsciiStrToUpper(framework_name),
+                      "_FRAMEWORK_IMPORTS");
 }
 
 bool IsProtobufLibraryBundledProtoFile(const FileDescriptor* file) {
@@ -988,12 +1002,12 @@ bool IsProtobufLibraryBundledProtoFile(const FileDescriptor* file) {
 
 namespace {
 
-bool PackageToPrefixesCollector::ConsumeLine(const absl::string_view& line,
+bool PackageToPrefixesCollector::ConsumeLine(absl::string_view line,
                                              std::string* out_error) {
   int offset = line.find('=');
   if (offset == absl::string_view::npos) {
     *out_error =
-        usage_ + " file line without equal sign: '" + absl::StrCat(line) + "'.";
+        absl::StrCat(usage_, " file line without equal sign: '", line, "'.");
     return false;
   }
   absl::string_view package =
@@ -1034,7 +1048,7 @@ bool ValidateObjCClassPrefix(
   const std::string package = file->package();
   // For files without packages, the can be registered as "no_package:PATH",
   // allowing the expected prefixes file.
-  static const std::string no_package_prefix("no_package:");
+  const std::string no_package_prefix("no_package:");
   const std::string lookup_key =
       package.empty() ? no_package_prefix + file->name() : package;
 
@@ -1175,7 +1189,7 @@ Options::Options() {
       getenv("GPB_OBJC_EXPECTED_PACKAGE_PREFIXES_SUPPRESSIONS");
   if (suppressions) {
     expected_prefixes_suppressions =
-        absl::StrSplit(suppressions, ";", absl::SkipEmpty());
+        absl::StrSplit(suppressions, ';', absl::SkipEmpty());
   }
   prefixes_must_be_registered =
       BoolFromEnvVar("GPB_OBJC_PREFIXES_MUST_BE_REGISTERED", false);
@@ -1190,36 +1204,36 @@ bool ValidateObjCClassPrefixes(const std::vector<const FileDescriptor*>& files,
 }
 
 bool ValidateObjCClassPrefixes(const std::vector<const FileDescriptor*>& files,
-                               const Options& generation_options,
+                               const Options& validation_options,
                                std::string* out_error) {
   // Allow a '-' as the path for the expected prefixes to completely disable
   // even the most basic of checks.
-  if (generation_options.expected_prefixes_path == "-") {
+  if (validation_options.expected_prefixes_path == "-") {
     return true;
   }
 
   // Load the expected package prefixes, if available, to validate against.
   std::map<std::string, std::string> expected_package_prefixes;
-  if (!LoadExpectedPackagePrefixes(generation_options.expected_prefixes_path,
+  if (!LoadExpectedPackagePrefixes(validation_options.expected_prefixes_path,
                                    &expected_package_prefixes, out_error)) {
     return false;
   }
 
-  for (int i = 0; i < files.size(); i++) {
+  for (auto file : files) {
     bool should_skip =
-        (std::find(generation_options.expected_prefixes_suppressions.begin(),
-                   generation_options.expected_prefixes_suppressions.end(),
-                   files[i]->name()) !=
-         generation_options.expected_prefixes_suppressions.end());
+        (std::find(validation_options.expected_prefixes_suppressions.begin(),
+                   validation_options.expected_prefixes_suppressions.end(),
+                   file->name()) !=
+         validation_options.expected_prefixes_suppressions.end());
     if (should_skip) {
       continue;
     }
 
-    bool is_valid = ValidateObjCClassPrefix(
-        files[i], generation_options.expected_prefixes_path,
+    bool is_valid =
+        ValidateObjCClassPrefix(file, validation_options.expected_prefixes_path,
                                 expected_package_prefixes,
-        generation_options.prefixes_must_be_registered,
-        generation_options.require_prefixes, out_error);
+                                validation_options.prefixes_must_be_registered,
+                                validation_options.require_prefixes, out_error);
     if (!is_valid) {
       return false;
     }

src/google/protobuf/compiler/objectivec/names.h

@@ -37,7 +37,6 @@
 #include <vector>
 
 #include "google/protobuf/descriptor.h"
-#include "google/protobuf/io/zero_copy_stream.h"
 
 // Must be included last
 #include "google/protobuf/port_def.inc"
@@ -48,88 +47,88 @@ namespace compiler {
 namespace objectivec {
 
 // Get/Set the path to a file to load for objc class prefix lookups.
-std::string PROTOC_EXPORT GetPackageToPrefixMappingsPath();
-void PROTOC_EXPORT SetPackageToPrefixMappingsPath(const std::string& file_path);
+PROTOC_EXPORT std::string GetPackageToPrefixMappingsPath();
+PROTOC_EXPORT void SetPackageToPrefixMappingsPath(const std::string& file_path);
 // Get/Set if the proto package should be used to make the default prefix for
 // symbols. This will then impact most of the type naming apis below. It is done
 // as a global to not break any other generator reusing the methods since they
 // are exported.
-bool PROTOC_EXPORT UseProtoPackageAsDefaultPrefix();
-void PROTOC_EXPORT SetUseProtoPackageAsDefaultPrefix(bool on_or_off);
+PROTOC_EXPORT bool UseProtoPackageAsDefaultPrefix();
+PROTOC_EXPORT void SetUseProtoPackageAsDefaultPrefix(bool on_or_off);
 // Get/Set the path to a file to load as exceptions when
 // `UseProtoPackageAsDefaultPrefix()` is `true`. An empty string means there
 // should be no exceptions.
-std::string PROTOC_EXPORT GetProtoPackagePrefixExceptionList();
-void PROTOC_EXPORT
-SetProtoPackagePrefixExceptionList(const std::string& file_path);
+PROTOC_EXPORT std::string GetProtoPackagePrefixExceptionList();
+PROTOC_EXPORT void SetProtoPackagePrefixExceptionList(
+    const std::string& file_path);
 // Get/Set a prefix to add before the prefix generated from the package name.
 // This is only used when UseProtoPackageAsDefaultPrefix() is True.
-std::string PROTOC_EXPORT GetForcedPackagePrefix();
-void PROTOC_EXPORT SetForcedPackagePrefix(const std::string& prefix);
+PROTOC_EXPORT std::string GetForcedPackagePrefix();
+PROTOC_EXPORT void SetForcedPackagePrefix(const std::string& prefix);
 
 // Returns true if the name requires a ns_returns_not_retained attribute applied
 // to it.
-bool PROTOC_EXPORT IsRetainedName(const std::string& name);
+PROTOC_EXPORT bool IsRetainedName(const std::string& name);
 
 // Returns true if the name starts with "init" and will need to have special
 // handling under ARC.
-bool PROTOC_EXPORT IsInitName(const std::string& name);
+PROTOC_EXPORT bool IsInitName(const std::string& name);
 
 // Returns true if the name requires a cf_returns_not_retained attribute applied
 // to it.
-bool PROTOC_EXPORT IsCreateName(const std::string& name);
+PROTOC_EXPORT bool IsCreateName(const std::string& name);
 
 // Gets the objc_class_prefix or the prefix made from the proto package.
-std::string PROTOC_EXPORT FileClassPrefix(const FileDescriptor* file);
+PROTOC_EXPORT std::string FileClassPrefix(const FileDescriptor* file);
 
 // Gets the path of the file we're going to generate (sans the .pb.h
 // extension).  The path will be dependent on the objectivec package
 // declared in the proto package.
-std::string PROTOC_EXPORT FilePath(const FileDescriptor* file);
+PROTOC_EXPORT std::string FilePath(const FileDescriptor* file);
 
 // Just like FilePath(), but without the directory part.
-std::string PROTOC_EXPORT FilePathBasename(const FileDescriptor* file);
+PROTOC_EXPORT std::string FilePathBasename(const FileDescriptor* file);
 
 // Gets the name of the root class we'll generate in the file.  This class
 // is not meant for external consumption, but instead contains helpers that
 // the rest of the classes need
-std::string PROTOC_EXPORT FileClassName(const FileDescriptor* file);
+PROTOC_EXPORT std::string FileClassName(const FileDescriptor* file);
 
 // These return the fully-qualified class name corresponding to the given
 // descriptor.
-std::string PROTOC_EXPORT ClassName(const Descriptor* descriptor);
-std::string PROTOC_EXPORT ClassName(const Descriptor* descriptor,
+PROTOC_EXPORT std::string ClassName(const Descriptor* descriptor);
+PROTOC_EXPORT std::string ClassName(const Descriptor* descriptor,
                                     std::string* out_suffix_added);
-std::string PROTOC_EXPORT EnumName(const EnumDescriptor* descriptor);
+PROTOC_EXPORT std::string EnumName(const EnumDescriptor* descriptor);
 
 // Returns the fully-qualified name of the enum value corresponding to the
 // the descriptor.
-std::string PROTOC_EXPORT EnumValueName(const EnumValueDescriptor* descriptor);
+PROTOC_EXPORT std::string EnumValueName(const EnumValueDescriptor* descriptor);
 
 // Returns the name of the enum value corresponding to the descriptor.
-std::string PROTOC_EXPORT
-EnumValueShortName(const EnumValueDescriptor* descriptor);
+PROTOC_EXPORT std::string EnumValueShortName(
+    const EnumValueDescriptor* descriptor);
 
 // Reverse what an enum does.
-std::string PROTOC_EXPORT UnCamelCaseEnumShortName(const std::string& name);
+PROTOC_EXPORT std::string UnCamelCaseEnumShortName(const std::string& name);
 
 // Returns the name to use for the extension (used as the method off the file's
 // Root class).
-std::string PROTOC_EXPORT
-ExtensionMethodName(const FieldDescriptor* descriptor);
+PROTOC_EXPORT std::string ExtensionMethodName(
+    const FieldDescriptor* descriptor);
 
 // Returns the transformed field name.
-std::string PROTOC_EXPORT FieldName(const FieldDescriptor* field);
-std::string PROTOC_EXPORT FieldNameCapitalized(const FieldDescriptor* field);
+PROTOC_EXPORT std::string FieldName(const FieldDescriptor* field);
+PROTOC_EXPORT std::string FieldNameCapitalized(const FieldDescriptor* field);
 
 // Returns the transformed oneof name.
-std::string PROTOC_EXPORT OneofEnumName(const OneofDescriptor* descriptor);
-std::string PROTOC_EXPORT OneofName(const OneofDescriptor* descriptor);
-std::string PROTOC_EXPORT
-OneofNameCapitalized(const OneofDescriptor* descriptor);
+PROTOC_EXPORT std::string OneofEnumName(const OneofDescriptor* descriptor);
+PROTOC_EXPORT std::string OneofName(const OneofDescriptor* descriptor);
+PROTOC_EXPORT std::string OneofNameCapitalized(
+    const OneofDescriptor* descriptor);
 
 // Reverse of the above.
-std::string PROTOC_EXPORT UnCamelCaseFieldName(const std::string& name,
+PROTOC_EXPORT std::string UnCamelCaseFieldName(const std::string& name,
                                                const FieldDescriptor* field);
 
 // The name the commonly used by the library when built as a framework.
@@ -137,8 +136,8 @@ std::string PROTOC_EXPORT UnCamelCaseFieldName(const std::string& name,
 extern PROTOC_EXPORT const char* const ProtobufLibraryFrameworkName;
 // Returns the CPP symbol name to use as the gate for framework style imports
 // for the given framework name to use.
-std::string PROTOC_EXPORT
-ProtobufFrameworkImportSymbol(const std::string& framework_name);
+PROTOC_EXPORT std::string ProtobufFrameworkImportSymbol(
+    const std::string& framework_name);
 
 // ---------------------------------------------------------------------------
 
@@ -146,8 +145,8 @@ ProtobufFrameworkImportSymbol(const std::string& framework_name);
 // building on top of ObjC Protos to be able to share the knowledge/enforcement.
 
 // Checks if the file is one of the proto's bundled with the library.
-bool PROTOC_EXPORT
-IsProtobufLibraryBundledProtoFile(const FileDescriptor* file);
+PROTOC_EXPORT bool IsProtobufLibraryBundledProtoFile(
+    const FileDescriptor* file);
 
 // Generator Prefix Validation Options (see generator.cc for a
 // description of each):
@@ -162,12 +161,12 @@ struct Options {
 // Checks the prefix for the given files and outputs any warnings as needed. If
 // there are flat out errors, then out_error is filled in with the first error
 // and the result is false.
-bool PROTOC_EXPORT ValidateObjCClassPrefixes(
+PROTOC_EXPORT bool ValidateObjCClassPrefixes(
     const std::vector<const FileDescriptor*>& files,
     const Options& validation_options, std::string* out_error);
 // Same was the other ValidateObjCClassPrefixes() calls, but the options all
 // come from the environment variables.
-bool PROTOC_EXPORT ValidateObjCClassPrefixes(
+PROTOC_EXPORT bool ValidateObjCClassPrefixes(
     const std::vector<const FileDescriptor*>& files, std::string* out_error);
 
 }  // namespace objectivec

src/google/protobuf/compiler/objectivec/names_unittest.cc

@@ -32,8 +32,6 @@
 
 #include <gtest/gtest.h>
 
-#include "google/protobuf/io/zero_copy_stream_impl_lite.h"
-
 namespace google {
 namespace protobuf {
 namespace compiler {

src/google/protobuf/compiler/objectivec/oneof.cc

@@ -62,8 +62,6 @@ OneofGenerator::OneofGenerator(const OneofDescriptor* descriptor)
   variables_["comments"] = comments;
 }
 
-OneofGenerator::~OneofGenerator() {}
-
 void OneofGenerator::SetOneofIndexBase(int index_base) {
   int index = descriptor_->index() + index_base;
   // Flip the sign to mark it as a oneof.
@@ -128,11 +126,11 @@ void OneofGenerator::GenerateClearFunctionImplementation(io::Printer* printer) {
   // clang-format on
 }
 
-std::string OneofGenerator::DescriptorName(void) const {
+std::string OneofGenerator::DescriptorName() const {
   return variables_.find("name")->second;
 }
 
-std::string OneofGenerator::HasIndexAsString(void) const {
+std::string OneofGenerator::HasIndexAsString() const {
   return variables_.find("index")->second;
 }
 

src/google/protobuf/compiler/objectivec/oneof.h

@@ -31,6 +31,7 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_ONEOF_H__
 #define GOOGLE_PROTOBUF_COMPILER_OBJECTIVEC_ONEOF_H__
 
+#include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ -46,7 +47,7 @@ namespace objectivec {
 class OneofGenerator {
  public:
   explicit OneofGenerator(const OneofDescriptor* descriptor);
-  ~OneofGenerator();
+  ~OneofGenerator() = default;
 
   OneofGenerator(const OneofGenerator&) = delete;
   OneofGenerator& operator=(const OneofGenerator&) = delete;
@@ -61,8 +62,8 @@ class OneofGenerator {
   void GeneratePropertyImplementation(io::Printer* printer);
   void GenerateClearFunctionImplementation(io::Printer* printer);
 
-  std::string DescriptorName(void) const;
-  std::string HasIndexAsString(void) const;
+  std::string DescriptorName() const;
+  std::string HasIndexAsString() const;
 
  private:
   const OneofDescriptor* descriptor_;

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

@@ -35,7 +35,6 @@
 
 #include "absl/strings/str_cat.h"
 #include "google/protobuf/compiler/objectivec/helpers.h"
-#include "google/protobuf/compiler/objectivec/names.h"
 #include "google/protobuf/io/printer.h"
 
 namespace google {
@@ -43,9 +42,6 @@ namespace protobuf {
 namespace compiler {
 namespace objectivec {
 
-using internal::WireFormat;
-using internal::WireFormatLite;
-
 namespace {
 
 const char* PrimitiveTypeName(const FieldDescriptor* descriptor) {
@@ -72,13 +68,13 @@ const char* PrimitiveTypeName(const FieldDescriptor* descriptor) {
     case OBJECTIVECTYPE_ENUM:
       return "int32_t";
     case OBJECTIVECTYPE_MESSAGE:
-      return NULL;  // Messages go through message_field.cc|h.
+      return nullptr;  // Messages go through message_field.cc|h.
   }
 
   // Some compilers report reaching end of function even though all cases of
   // the enum are handed in the switch.
   GOOGLE_LOG(FATAL) << "Can't get here.";
-  return NULL;
+  return nullptr;
 }
 
 const char* PrimitiveArrayTypeName(const FieldDescriptor* descriptor) {
@@ -112,7 +108,7 @@ const char* PrimitiveArrayTypeName(const FieldDescriptor* descriptor) {
   // Some compilers report reaching end of function even though all cases of
   // the enum are handed in the switch.
   GOOGLE_LOG(FATAL) << "Can't get here.";
-  return NULL;
+  return nullptr;
 }
 
 void SetPrimitiveVariables(const FieldDescriptor* descriptor,
@@ -130,8 +126,6 @@ PrimitiveFieldGenerator::PrimitiveFieldGenerator(
   SetPrimitiveVariables(descriptor, &variables_);
 }
 
-PrimitiveFieldGenerator::~PrimitiveFieldGenerator() {}
-
 void PrimitiveFieldGenerator::GenerateFieldStorageDeclaration(
     io::Printer* printer) const {
   if (GetObjectiveCType(descriptor_) == OBJECTIVECTYPE_BOOLEAN) {
@@ -141,7 +135,7 @@ void PrimitiveFieldGenerator::GenerateFieldStorageDeclaration(
   }
 }
 
-int PrimitiveFieldGenerator::ExtraRuntimeHasBitsNeeded(void) const {
+int PrimitiveFieldGenerator::ExtraRuntimeHasBitsNeeded() const {
   if (GetObjectiveCType(descriptor_) == OBJECTIVECTYPE_BOOLEAN) {
     // Reserve a bit for the storage of the boolean.
     return 1;
@@ -149,10 +143,10 @@ int PrimitiveFieldGenerator::ExtraRuntimeHasBitsNeeded(void) const {
   return 0;
 }
 
-void PrimitiveFieldGenerator::SetExtraRuntimeHasBitsBase(int has_base) {
+void PrimitiveFieldGenerator::SetExtraRuntimeHasBitsBase(int index_base) {
   if (GetObjectiveCType(descriptor_) == OBJECTIVECTYPE_BOOLEAN) {
     // Set into the offset the has bit to use for the actual value.
-    variables_["storage_offset_value"] = absl::StrCat(has_base);
+    variables_["storage_offset_value"] = absl::StrCat(index_base);
     variables_["storage_offset_comment"] =
         "  // Stored in _has_storage_ to save space.";
   }
@@ -165,8 +159,6 @@ PrimitiveObjFieldGenerator::PrimitiveObjFieldGenerator(
   variables_["property_storage_attribute"] = "copy";
 }
 
-PrimitiveObjFieldGenerator::~PrimitiveObjFieldGenerator() {}
-
 RepeatedPrimitiveFieldGenerator::RepeatedPrimitiveFieldGenerator(
     const FieldDescriptor* descriptor)
     : RepeatedFieldGenerator(descriptor) {
@@ -182,8 +174,6 @@ RepeatedPrimitiveFieldGenerator::RepeatedPrimitiveFieldGenerator(
   }
 }
 
-RepeatedPrimitiveFieldGenerator::~RepeatedPrimitiveFieldGenerator() {}
-
 }  // namespace objectivec
 }  // namespace compiler
 }  // namespace protobuf

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

@@ -43,16 +43,15 @@ class PrimitiveFieldGenerator : public SingleFieldGenerator {
 
  protected:
   explicit PrimitiveFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~PrimitiveFieldGenerator();
+  ~PrimitiveFieldGenerator() override = default;
 
   PrimitiveFieldGenerator(const PrimitiveFieldGenerator&) = delete;
   PrimitiveFieldGenerator& operator=(const PrimitiveFieldGenerator&) = delete;
 
-  virtual void GenerateFieldStorageDeclaration(
-      io::Printer* printer) const override;
+  void GenerateFieldStorageDeclaration(io::Printer* printer) const override;
 
-  virtual int ExtraRuntimeHasBitsNeeded(void) const override;
-  virtual void SetExtraRuntimeHasBitsBase(int index_base) override;
+  int ExtraRuntimeHasBitsNeeded() const override;
+  void SetExtraRuntimeHasBitsBase(int index_base) override;
 };
 
 class PrimitiveObjFieldGenerator : public ObjCObjFieldGenerator {
@@ -60,7 +59,7 @@ class PrimitiveObjFieldGenerator : public ObjCObjFieldGenerator {
 
  protected:
   explicit PrimitiveObjFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~PrimitiveObjFieldGenerator();
+  ~PrimitiveObjFieldGenerator() override = default;
 
   PrimitiveObjFieldGenerator(const PrimitiveObjFieldGenerator&) = delete;
   PrimitiveObjFieldGenerator& operator=(const PrimitiveObjFieldGenerator&) =
@@ -72,7 +71,7 @@ class RepeatedPrimitiveFieldGenerator : public RepeatedFieldGenerator {
 
  protected:
   explicit RepeatedPrimitiveFieldGenerator(const FieldDescriptor* descriptor);
-  virtual ~RepeatedPrimitiveFieldGenerator();
+  ~RepeatedPrimitiveFieldGenerator() override = default;
 
   RepeatedPrimitiveFieldGenerator(const RepeatedPrimitiveFieldGenerator&) =
       delete;