Merge branch 'master' into 3.15.x

4 years ago · 87aa9adb86
parent 878be3569e 97cb3a862f
commit 87aa9adb86
248 changed files with 5350 additions and 4956 deletions
--- a/.github/mergeable.yml
+++ b/.github/mergeable.yml
@ -11,8 +11,8 @@ mergeable:
                regex: 'release notes: yes'
                message: 'Please include release notes: yes'
            - must_include:
-                regex: '^(c#|c\+\+|cleanup|conformance tests|integration|java|javascript|go|objective-c|php|python|ruby|bazel|cmake|protoc)'
-                message: 'Please include at least a language label (e.g., c++, java, python). Or apply one of the following labels: bazel, cmake, cleanup, conformance tests, integration, protoc.'
+                regex: '^(autotools|bazel|c#|c\+\+|cleanup|cmake|conformance tests|integration|go|java|javascript|objective-c|php|protoc|python|ruby|kotlin)'
+                message: 'Please include at least a language label (e.g., c++, java, python). Or apply one of the following labels: autotools, bazel, cmake, cleanup, conformance tests, integration, protoc.'
          - must_include:
              regex: 'release notes: no'
              message: 'Please include release notes: no'
--- a/.github/workflows/codespell.yml
+++ b/.github/workflows/codespell.yml
@ -13,4 +13,4 @@ jobs:
        with:
          check_filenames: true
          skip: ./.git,./conformance/third_party,*.snk,*.pb,*.pb.cc,*.pb.h,./src/google/protobuf/testdata,./objectivec/Tests,./python/compatibility_tests/v2.5.0/tests/google/protobuf/internal
-          ignore_words_list: "alow,alse,ba,cleare,copyable,cloneable,dedup,dur,errorprone,files',fo,fundementals,hel,importd,inout,leapyear,nd,nin,ois,ons,parseable,process',te,testof,ue,unparseable,wasn,wee,gae,keyserver,objext,od"
+          ignore_words_list: "alow,alse,ba,cleare,copyable,cloneable,dedup,dur,errorprone,files',fo,fundementals,hel,importd,inout,leapyear,nd,nin,ois,ons,parseable,process',te,testof,ue,unparseable,wasn,wee,gae,keyserver,objext,od,OptIn"
--- a/.gitignore
+++ b/.gitignore
@ -83,6 +83,7 @@ src/**/*.trs

 # JavaBuild output.
 java/core/target
+java/lite/target
 java/util/target
 javanano/target
 java/.idea
--- a/44
+++ b/44
@ -14,38 +14,6 @@ exports_files(["LICENSE"])
 # build configuration
 ################################################################################

-# TODO(yannic): Remove in 3.14.0.
-string_flag(
-    name = "incompatible_use_com_google_googletest",
-    build_setting_default = "true",
-    values = ["true", "false"]
-)
-
-config_setting(
-    name = "use_com_google_googletest",
-    flag_values = {
-        "//:incompatible_use_com_google_googletest": "true"
-    },
-)
-
-GTEST = select({
-    "//:use_com_google_googletest": [
-        "@com_google_googletest//:gtest",
-    ],
-    "//conditions:default": [
-        "//external:gtest",
-    ],
-})
-
-GTEST_MAIN = select({
-    "//:use_com_google_googletest": [
-        "@com_google_googletest//:gtest_main",
-    ],
-    "//conditions:default": [
-        "//external:gtest_main",
-    ],
-})
-
 ################################################################################
 # ZLIB configuration
 ################################################################################
@ -571,6 +539,7 @@ COMMON_TEST_SRCS = [

 cc_binary(
    name = "test_plugin",
+    testonly = True,
    srcs = [
        # AUTOGEN(test_plugin_srcs)
        "src/google/protobuf/compiler/mock_code_generator.cc",
@ -580,7 +549,8 @@ cc_binary(
    deps = [
        ":protobuf",
        ":protoc_lib",
-    ] + GTEST,
+        "@com_google_googletest//:gtest",
+    ],
 )

 cc_test(
@ -592,7 +562,9 @@ cc_test(
    ],
    deps = [
        ":protobuf_lite",
-    ] + GTEST_MAIN,
+        "@com_google_googletest//:gtest",
+        "@com_google_googletest//:gtest_main",
+    ],
 )

 cc_test(
@ -695,7 +667,9 @@ cc_test(
        ":cc_test_protos",
        ":protobuf",
        ":protoc_lib",
-    ] + PROTOBUF_DEPS + GTEST_MAIN,
+        "@com_google_googletest//:gtest",
+        "@com_google_googletest//:gtest_main",
+    ] + PROTOBUF_DEPS,
 )

 ################################################################################
--- a/CHANGES.txt
+++ b/CHANGES.txt
@ -1,3 +1,45 @@
+Unreleased Changes (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
+
+  C++
+  * The ::pb namespace is no longer exposed due to conflicts.
+  * Allow MessageDifferencer::TreatAsSet() (and friends) to override previous
+    calls instead of crashing.
+  * Reduce the size of generated proto headers for protos with `string` or
+    `bytes` fields.
+  * Move arena() operation on uncommon path to out-of-line routine
+  * For iterator-pair function parameter types, take both iterators by value.
+  * Code-space savings and perhaps some modest performance improvements in
+    RepeatedPtrField.
+  * Eliminate nullptr check from every tag parse.
+  * Remove unused _$name$_cached_byte_size_ fields.
+  * Serialize extension ranges together when not broken by a proto field in the
+    middle.
+  * Do out-of-line allocation and deallocation of string object in ArenaString.
+  * Streamline ParseContext::ParseMessage<T> to avoid code bloat and improve
+    performance.
+  * New member functions RepeatedField::Assign, RepeatedPtrField::{Add, Assign}.
+  * Fix undefined behavior warning due to innocuous uninitialization of value
+    on an error path.
+  * Avoid expensive inlined code space for encoding message length for messages
+    >= 128 bytes and instead do a procedure call to a shared out-of-line routine.
+  * util::DefaultFieldComparator will be final in a future version of protobuf.
+    Subclasses should inherit from SimpleFieldComparator instead.
+
+  Java:
+  * Detect invalid overflow of byteLimit and return InvalidProtocolBufferException as documented.
+  * Exceptions thrown while reading from an InputStream in parseFrom are now
+    included as causes.
+  * Support potentially more efficient proto parsing from RopeByteStrings.
+  * Clarify runtime of ByteString.Output.toStringBuffer().
+
+  Python
+  * Fixed a bug in text format where a trailing colon was printed for repeated field.
+  * When TextFormat encounters a duplicate message map key, replace the current
+    one instead of merging.
+
+  JavaScript
+  * Make Any.pack() chainable.
+
 2021-04-02 version 3.15.7 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)

  C++
--- a/Makefile.am
+++ b/Makefile.am
@ -529,7 +529,6 @@ java_EXTRA_DIST=
  java/core/src/test/proto/com/google/protobuf/test_check_utf8.proto               \
  java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto          \
  java/core/src/test/proto/com/google/protobuf/test_custom_options.proto           \
-  java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto         \
  java/core/src/test/proto/com/google/protobuf/wrappers_test.proto                 \
  java/lite.md                                                                     \
  java/lite/BUILD                                                                  \
--- a/21
+++ b/21
@ -17,6 +17,15 @@ http_archive(
    ],
 )

+http_archive(
+    name = "com_github_google_benchmark",
+    sha256 = "2a778d821997df7d8646c9c59b8edb9a573a6e04c534c01892a40aa524a7b68c",
+    strip_prefix = "benchmark-bf585a2789e30585b4e3ce6baf11ef2750b54677",
+    urls = [
+        "https://github.com/google/benchmark/archive/bf585a2789e30585b4e3ce6baf11ef2750b54677.zip",
+    ],
+)
+
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("//:protobuf_deps.bzl", "protobuf_deps")

@ -29,18 +38,6 @@ bind(
    actual = "//util/python:python_headers",
 )

-# TODO(yannic): Remove in 3.14.0.
-bind(
-    name = "gtest",
-    actual = "@com_google_googletest//:gtest",
-)
-
-# TODO(yannic): Remove in 3.14.0.
-bind(
-    name = "gtest_main",
-    actual = "@com_google_googletest//:gtest_main",
-)
-
 jvm_maven_import_external(
    name = "guava_maven",
    artifact = "com.google.guava:guava:18.0",
--- a/benchmarks/BUILD
+++ b/benchmarks/BUILD
@ -0,0 +1,65 @@
+load("@rules_cc//cc:defs.bzl", "cc_proto_library")
+load("@rules_java//java:defs.bzl", "java_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+proto_library(
+    name = "benchmarks_proto",
+    srcs = [
+        "benchmarks.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+)
+
+cc_proto_library(
+    name = "benchmarks_cc_proto",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    deps = [
+        "benchmarks_proto",
+    ],
+)
+
+java_proto_library(
+    name = "benchmarks_java_proto",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    deps = [
+        "benchmarks_proto",
+    ],
+)
+
+proto_library(
+    name = "google_size_proto",
+    srcs = [
+        "google_size.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+)
+
+cc_proto_library(
+    name = "google_size_cc_proto",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    deps = [
+        "google_size_proto",
+    ],
+)
+
+java_proto_library(
+    name = "google_size_java_proto",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    deps = [
+        "google_size_proto",
+    ],
+)
--- a/benchmarks/cpp/BUILD
+++ b/benchmarks/cpp/BUILD
@ -0,0 +1,15 @@
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+
+cc_binary(
+    name = "cpp",
+    srcs = [
+        "cpp_benchmark.cc",
+    ],
+    tags = ["benchmark"],
+    deps = [
+        "//:protobuf",
+        "//benchmarks:benchmarks_cc_proto",
+        "//benchmarks/datasets:cc_protos",
+        "@com_github_google_benchmark//:benchmark_main",
+    ],
+)
--- a/benchmarks/datasets/BUILD
+++ b/benchmarks/datasets/BUILD
@ -0,0 +1,59 @@
+load("@rules_cc//cc:defs.bzl", "cc_library")
+load("@rules_java//java:defs.bzl", "java_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+filegroup(
+    name = "datasets",
+    srcs = [
+        "//benchmarks/datasets/google_message1/proto2:datasets",
+        "//benchmarks/datasets/google_message1/proto3:datasets",
+        "//benchmarks/datasets/google_message2:datasets",
+        "//benchmarks/datasets/google_message3:datasets",
+        "//benchmarks/datasets/google_message4:datasets",
+    ],
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+)
+
+proto_library(
+    name = "protos",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    deps = [
+        "//benchmarks/datasets/google_message1/proto2:benchmark_message1_proto2_proto",
+        "//benchmarks/datasets/google_message1/proto3:benchmark_message1_proto3_proto",
+        "//benchmarks/datasets/google_message2:benchmark_message2_proto",
+        "//benchmarks/datasets/google_message3:benchmark_message3_proto",
+        "//benchmarks/datasets/google_message4:benchmark_message4_proto",
+    ],
+)
+
+cc_library(
+    name = "cc_protos",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    deps = [
+        "//benchmarks/datasets/google_message1/proto2:benchmark_message1_proto2_cc_proto",
+        "//benchmarks/datasets/google_message1/proto3:benchmark_message1_proto3_cc_proto",
+        "//benchmarks/datasets/google_message2:benchmark_message2_cc_proto",
+        "//benchmarks/datasets/google_message3:benchmark_message3_cc_proto",
+        "//benchmarks/datasets/google_message4:benchmark_message4_cc_proto",
+    ],
+)
+
+java_library(
+    name = "java_protos",
+    visibility = [
+        "//benchmarks:__subpackages__",
+    ],
+    exports = [
+        "//benchmarks/datasets/google_message1/proto2:benchmark_message1_proto2_java_proto",
+        "//benchmarks/datasets/google_message1/proto3:benchmark_message1_proto3_java_proto",
+        "//benchmarks/datasets/google_message2:benchmark_message2_java_proto",
+        "//benchmarks/datasets/google_message3:benchmark_message3_java_proto",
+        "//benchmarks/datasets/google_message4:benchmark_message4_java_proto",
+    ],
+)
--- a/benchmarks/datasets/google_message1/proto2/BUILD
+++ b/benchmarks/datasets/google_message1/proto2/BUILD
@ -0,0 +1,44 @@
+load("@rules_cc//cc:defs.bzl", "cc_proto_library")
+load("@rules_java//java:defs.bzl", "java_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+filegroup(
+    name = "datasets",
+    srcs = [
+        "dataset.google_message1_proto2.pb",
+    ],
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+proto_library(
+    name = "benchmark_message1_proto2_proto",
+    srcs = [
+        "benchmark_message1_proto2.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+cc_proto_library(
+    name = "benchmark_message1_proto2_cc_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message1_proto2_proto",
+    ],
+)
+
+java_proto_library(
+    name = "benchmark_message1_proto2_java_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message1_proto2_proto",
+    ],
+)
--- a/benchmarks/datasets/google_message1/proto3/BUILD
+++ b/benchmarks/datasets/google_message1/proto3/BUILD
@ -0,0 +1,44 @@
+load("@rules_cc//cc:defs.bzl", "cc_proto_library")
+load("@rules_java//java:defs.bzl", "java_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+filegroup(
+    name = "datasets",
+    srcs = [
+        "dataset.google_message1_proto3.pb",
+    ],
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+proto_library(
+    name = "benchmark_message1_proto3_proto",
+    srcs = [
+        "benchmark_message1_proto3.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+cc_proto_library(
+    name = "benchmark_message1_proto3_cc_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message1_proto3_proto",
+    ],
+)
+
+java_proto_library(
+    name = "benchmark_message1_proto3_java_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message1_proto3_proto",
+    ],
+)
--- a/benchmarks/datasets/google_message2/BUILD
+++ b/benchmarks/datasets/google_message2/BUILD
@ -0,0 +1,44 @@
+load("@rules_cc//cc:defs.bzl", "cc_proto_library")
+load("@rules_java//java:defs.bzl", "java_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+filegroup(
+    name = "datasets",
+    srcs = [
+        "dataset.google_message2.pb",
+    ],
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+proto_library(
+    name = "benchmark_message2_proto",
+    srcs = [
+        "benchmark_message2.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+cc_proto_library(
+    name = "benchmark_message2_cc_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message2_proto",
+    ],
+)
+
+java_proto_library(
+    name = "benchmark_message2_java_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message2_proto",
+    ],
+)
--- a/benchmarks/datasets/google_message3/BUILD
+++ b/benchmarks/datasets/google_message3/BUILD
@ -0,0 +1,50 @@
+load("@rules_cc//cc:defs.bzl", "cc_proto_library")
+load("@rules_java//java:defs.bzl", "java_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+filegroup(
+    name = "datasets",
+    srcs = [],
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+proto_library(
+    name = "benchmark_message3_proto",
+    srcs = [
+        "benchmark_message3.proto",
+        "benchmark_message3_1.proto",
+        "benchmark_message3_2.proto",
+        "benchmark_message3_3.proto",
+        "benchmark_message3_4.proto",
+        "benchmark_message3_5.proto",
+        "benchmark_message3_6.proto",
+        "benchmark_message3_7.proto",
+        "benchmark_message3_8.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+cc_proto_library(
+    name = "benchmark_message3_cc_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message3_proto",
+    ],
+)
+
+java_proto_library(
+    name = "benchmark_message3_java_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message3_proto",
+    ],
+)
--- a/benchmarks/datasets/google_message4/BUILD
+++ b/benchmarks/datasets/google_message4/BUILD
@ -0,0 +1,45 @@
+load("@rules_cc//cc:defs.bzl", "cc_proto_library")
+load("@rules_java//java:defs.bzl", "java_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+
+filegroup(
+    name = "datasets",
+    srcs = [],
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+proto_library(
+    name = "benchmark_message4_proto",
+    srcs = [
+        "benchmark_message4.proto",
+        "benchmark_message4_1.proto",
+        "benchmark_message4_2.proto",
+        "benchmark_message4_3.proto",
+    ],
+    strip_import_prefix = "/benchmarks",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+)
+
+cc_proto_library(
+    name = "benchmark_message4_cc_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message4_proto",
+    ],
+)
+
+java_proto_library(
+    name = "benchmark_message4_java_proto",
+    visibility = [
+        "//benchmarks/datasets:__pkg__",
+    ],
+    deps = [
+        "benchmark_message4_proto",
+    ],
+)
--- a/cmake/install.cmake
+++ b/cmake/install.cmake
@ -30,7 +30,9 @@ endforeach()

 if (protobuf_BUILD_PROTOC_BINARIES)
  install(TARGETS protoc EXPORT protobuf-targets
-    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT protoc)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    BUNDLE DESTINATION ${CMAKE_INSTALL_BINDIR}
+    COMPONENT protoc)
  if (UNIX AND NOT APPLE)
    set_property(TARGET protoc
      PROPERTY INSTALL_RPATH "$ORIGIN/../${CMAKE_INSTALL_LIBDIR}")
--- a/cmake/protobuf-config.cmake.in
+++ b/cmake/protobuf-config.cmake.in
@ -15,7 +15,7 @@ function(protobuf_generate)
  if(COMMAND target_sources)
    list(APPEND _singleargs TARGET)
  endif()
-  set(_multiargs PROTOS IMPORT_DIRS GENERATE_EXTENSIONS)
+  set(_multiargs PROTOS IMPORT_DIRS GENERATE_EXTENSIONS PROTOC_OPTIONS)

  cmake_parse_arguments(protobuf_generate "${_options}" "${_singleargs}" "${_multiargs}" "${ARGN}")

@ -130,9 +130,9 @@ function(protobuf_generate)
    add_custom_command(
      OUTPUT ${_generated_srcs}
      COMMAND  protobuf::protoc
-      ARGS --${protobuf_generate_LANGUAGE}_out ${_dll_export_decl}${protobuf_generate_PROTOC_OUT_DIR} ${_plugin} ${_protobuf_include_path} ${_abs_file}
+      ARGS ${protobuf_generate_PROTOC_OPTIONS} --${protobuf_generate_LANGUAGE}_out ${_dll_export_decl}${protobuf_generate_PROTOC_OUT_DIR} ${_plugin} ${_protobuf_include_path} ${_abs_file}
      DEPENDS ${_abs_file} protobuf::protoc
-      COMMENT "Running ${protobuf_generate_LANGUAGE} protocol buffer compiler on ${_proto}"
+      COMMENT "Running ${protobuf_generate_LANGUAGE} protocol buffer compiler on ${_proto}. Custom options: ${protobuf_generate_PROTOC_OPTIONS}"
      VERBATIM )
  endforeach()

--- a/configure.ac
+++ b/configure.ac
@ -223,6 +223,19 @@ case "$target_os" in
 esac
 AM_CONDITIONAL([OBJC_CONFORMANCE_TEST], [test $OBJC_CONFORMANCE_TEST = 1])

+AC_MSG_CHECKING(whether -llog is needed)
+ANDROID_TEST=no
+case "$target_os" in
+  *android*)
+    ANDROID_TEST=yes
+    ;;
+esac
+AC_MSG_RESULT($ANDROID_TEST)
+if test "x$ANDROID_TEST" = xyes; then
+  LIBLOG_LIBS="-llog"
+fi
+AC_SUBST([LIBLOG_LIBS])
+
 # HACK:  Make gmock's configure script pick up our copy of CFLAGS and CXXFLAGS,
 #   since the flags added by ACX_CHECK_SUNCC must be used when compiling gmock
 #   too.
--- a/conformance/binary_json_conformance_suite.cc
+++ b/conformance/binary_json_conformance_suite.cc
@ -300,7 +300,7 @@ const FieldDescriptor* GetFieldForOneofType(FieldDescriptor::Type type,
 }

 string UpperCase(string str) {
-  for (int i = 0; i < str.size(); i++) {
+  for (size_t i = 0; i < str.size(); i++) {
    str[i] = toupper(str[i]);
  }
  return str;
--- a/conformance/conformance_cpp.cc
+++ b/conformance/conformance_cpp.cc
@ -55,6 +55,7 @@ using google::protobuf::util::JsonToBinaryString;
 using google::protobuf::util::NewTypeResolverForDescriptorPool;
 using google::protobuf::util::TypeResolver;
 using protobuf_test_messages::proto3::TestAllTypesProto3;
+using protobuf_test_messages::proto2::TestAllTypesProto2;
 using std::string;

 static const char kTypeUrlPrefix[] = "type.googleapis.com";
@ -102,6 +103,8 @@ void CheckedWrite(int fd, const void *buf, size_t len) {

 void DoTest(const ConformanceRequest& request, ConformanceResponse* response) {
  Message *test_message;
+  google::protobuf::LinkMessageReflection<TestAllTypesProto2>();
+  google::protobuf::LinkMessageReflection<TestAllTypesProto3>();
  const Descriptor *descriptor = DescriptorPool::generated_pool()->FindMessageTypeByName(
      request.message_type());
  if (!descriptor) {
@ -131,7 +134,7 @@ void DoTest(const ConformanceRequest& request, ConformanceResponse* response) {
                             &proto_binary, options);
      if (!status.ok()) {
        response->set_parse_error(string("Parse error: ") +
-                                  std::string(status.error_message()));
+                                  std::string(status.message()));
        return;
      }

@ -186,7 +189,7 @@ void DoTest(const ConformanceRequest& request, ConformanceResponse* response) {
      if (!status.ok()) {
        response->set_serialize_error(
            string("Failed to serialize JSON output: ") +
-            std::string(status.error_message()));
+            std::string(status.message()));
        return;
      }
      break;
--- a/conformance/conformance_test_runner.cc
+++ b/conformance/conformance_test_runner.cc
@ -297,7 +297,7 @@ void ForkPipeRunner::SpawnTestProgram() {

    std::vector<const char *> argv;
    argv.push_back(executable.get());
-    for (int i = 0; i < executable_args_.size(); ++i) {
+    for (size_t i = 0; i < executable_args_.size(); ++i) {
      argv.push_back(executable_args_[i].c_str());
    }
    argv.push_back(nullptr);
@ -307,7 +307,7 @@ void ForkPipeRunner::SpawnTestProgram() {
 }

 void ForkPipeRunner::CheckedWrite(int fd, const void *buf, size_t len) {
-  if (write(fd, buf, len) != len) {
+  if (static_cast<size_t>(write(fd, buf, len)) != len) {
    GOOGLE_LOG(FATAL) << current_test_name_
               << ": error writing to test program: " << strerror(errno);
  }
--- a/conformance/text_format_conformance_suite.cc
+++ b/conformance/text_format_conformance_suite.cc
@ -451,6 +451,27 @@ void TextFormatConformanceTestSuite::RunSuiteImpl() {
      }
      )",
                                    prototype);
+
+  prototype.Clear();
+  ConformanceRequestSetting setting_map(
+      REQUIRED, conformance::TEXT_FORMAT, conformance::PROTOBUF,
+      conformance::TEXT_FORMAT_TEST, prototype, "DuplicateMapKey", R"(
+      map_string_nested_message {
+        key: "duplicate"
+        value: { a: 123 }
+      }
+      map_string_nested_message {
+        key: "duplicate"
+        value: { corecursive: {} }
+      }
+      )");
+  // The last-specified value will be retained in a parsed map
+  RunValidInputTest(setting_map, R"(
+      map_string_nested_message {
+        key: "duplicate"
+        value: { corecursive: {} }
+      }
+      )");
 }

 }  // namespace protobuf
--- a/csharp/install_dotnet_sdk.ps1
+++ b/csharp/install_dotnet_sdk.ps1
@ -17,4 +17,4 @@ Invoke-WebRequest -Uri $InstallScriptUrl -OutFile $InstallScriptPath
 # The SDK versions to install should be kept in sync with versions
 # installed by kokoro/linux/dockerfile/test/csharp/Dockerfile
 &$InstallScriptPath -Version 2.1.802
-&$InstallScriptPath -Version 3.1.301
+&$InstallScriptPath -Version 5.0.102
--- a/csharp/src/Google.Protobuf.Benchmarks/Google.Protobuf.Benchmarks.csproj
+++ b/csharp/src/Google.Protobuf.Benchmarks/Google.Protobuf.Benchmarks.csproj
@ -2,7 +2,7 @@

  <PropertyGroup>
    <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
    <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
    <SignAssembly>true</SignAssembly>
    <IsPackable>False</IsPackable>
--- a/csharp/src/Google.Protobuf.Test.TestProtos/UnittestProto3Optional.cs
+++ b/csharp/src/Google.Protobuf.Test.TestProtos/UnittestProto3Optional.cs
@ -25,49 +25,54 @@ namespace ProtobufUnittest {
      byte[] descriptorData = global::System.Convert.FromBase64String(
          string.Concat(
            "Ci5nb29nbGUvcHJvdG9idWYvdW5pdHRlc3RfcHJvdG8zX29wdGlvbmFsLnBy",
-            "b3RvEhFwcm90b2J1Zl91bml0dGVzdCKxCgoSVGVzdFByb3RvM09wdGlvbmFs",
-            "EhsKDm9wdGlvbmFsX2ludDMyGAEgASgFSACIAQESGwoOb3B0aW9uYWxfaW50",
-            "NjQYAiABKANIAYgBARIcCg9vcHRpb25hbF91aW50MzIYAyABKA1IAogBARIc",
-            "Cg9vcHRpb25hbF91aW50NjQYBCABKARIA4gBARIcCg9vcHRpb25hbF9zaW50",
-            "MzIYBSABKBFIBIgBARIcCg9vcHRpb25hbF9zaW50NjQYBiABKBJIBYgBARId",
-            "ChBvcHRpb25hbF9maXhlZDMyGAcgASgHSAaIAQESHQoQb3B0aW9uYWxfZml4",
-            "ZWQ2NBgIIAEoBkgHiAEBEh4KEW9wdGlvbmFsX3NmaXhlZDMyGAkgASgPSAiI",
-            "AQESHgoRb3B0aW9uYWxfc2ZpeGVkNjQYCiABKBBICYgBARIbCg5vcHRpb25h",
-            "bF9mbG9hdBgLIAEoAkgKiAEBEhwKD29wdGlvbmFsX2RvdWJsZRgMIAEoAUgL",
-            "iAEBEhoKDW9wdGlvbmFsX2Jvb2wYDSABKAhIDIgBARIcCg9vcHRpb25hbF9z",
-            "dHJpbmcYDiABKAlIDYgBARIbCg5vcHRpb25hbF9ieXRlcxgPIAEoDEgOiAEB",
-            "Eh4KDW9wdGlvbmFsX2NvcmQYECABKAlCAggBSA+IAQESWQoXb3B0aW9uYWxf",
-            "bmVzdGVkX21lc3NhZ2UYEiABKAsyMy5wcm90b2J1Zl91bml0dGVzdC5UZXN0",
-            "UHJvdG8zT3B0aW9uYWwuTmVzdGVkTWVzc2FnZUgQiAEBElkKE2xhenlfbmVz",
-            "dGVkX21lc3NhZ2UYEyABKAsyMy5wcm90b2J1Zl91bml0dGVzdC5UZXN0UHJv",
-            "dG8zT3B0aW9uYWwuTmVzdGVkTWVzc2FnZUICKAFIEYgBARJTChRvcHRpb25h",
-            "bF9uZXN0ZWRfZW51bRgVIAEoDjIwLnByb3RvYnVmX3VuaXR0ZXN0LlRlc3RQ",
-            "cm90bzNPcHRpb25hbC5OZXN0ZWRFbnVtSBKIAQESFgoOc2luZ3VsYXJfaW50",
-            "MzIYFiABKAUSFgoOc2luZ3VsYXJfaW50NjQYFyABKAMaJwoNTmVzdGVkTWVz",
-            "c2FnZRIPCgJiYhgBIAEoBUgAiAEBQgUKA19iYiJKCgpOZXN0ZWRFbnVtEg8K",
-            "C1VOU1BFQ0lGSUVEEAASBwoDRk9PEAESBwoDQkFSEAISBwoDQkFaEAMSEAoD",
-            "TkVHEP///////////wFCEQoPX29wdGlvbmFsX2ludDMyQhEKD19vcHRpb25h",
-            "bF9pbnQ2NEISChBfb3B0aW9uYWxfdWludDMyQhIKEF9vcHRpb25hbF91aW50",
-            "NjRCEgoQX29wdGlvbmFsX3NpbnQzMkISChBfb3B0aW9uYWxfc2ludDY0QhMK",
-            "EV9vcHRpb25hbF9maXhlZDMyQhMKEV9vcHRpb25hbF9maXhlZDY0QhQKEl9v",
-            "cHRpb25hbF9zZml4ZWQzMkIUChJfb3B0aW9uYWxfc2ZpeGVkNjRCEQoPX29w",
-            "dGlvbmFsX2Zsb2F0QhIKEF9vcHRpb25hbF9kb3VibGVCEAoOX29wdGlvbmFs",
-            "X2Jvb2xCEgoQX29wdGlvbmFsX3N0cmluZ0IRCg9fb3B0aW9uYWxfYnl0ZXNC",
-            "EAoOX29wdGlvbmFsX2NvcmRCGgoYX29wdGlvbmFsX25lc3RlZF9tZXNzYWdl",
-            "QhYKFF9sYXp5X25lc3RlZF9tZXNzYWdlQhcKFV9vcHRpb25hbF9uZXN0ZWRf",
-            "ZW51bSKJAgoZVGVzdFByb3RvM09wdGlvbmFsTWVzc2FnZRJSCg5uZXN0ZWRf",
-            "bWVzc2FnZRgBIAEoCzI6LnByb3RvYnVmX3VuaXR0ZXN0LlRlc3RQcm90bzNP",
-            "cHRpb25hbE1lc3NhZ2UuTmVzdGVkTWVzc2FnZRJgChdvcHRpb25hbF9uZXN0",
-            "ZWRfbWVzc2FnZRgCIAEoCzI6LnByb3RvYnVmX3VuaXR0ZXN0LlRlc3RQcm90",
-            "bzNPcHRpb25hbE1lc3NhZ2UuTmVzdGVkTWVzc2FnZUgAiAEBGhoKDU5lc3Rl",
-            "ZE1lc3NhZ2USCQoBcxgBIAEoCUIaChhfb3B0aW9uYWxfbmVzdGVkX21lc3Nh",
-            "Z2VCJQohY29tLmdvb2dsZS5wcm90b2J1Zi50ZXN0aW5nLnByb3RvUAFiBnBy",
-            "b3RvMw=="));
+            "b3RvEhFwcm90b2J1Zl91bml0dGVzdBogZ29vZ2xlL3Byb3RvYnVmL2Rlc2Ny",
+            "aXB0b3IucHJvdG8isQoKElRlc3RQcm90bzNPcHRpb25hbBIbCg5vcHRpb25h",
+            "bF9pbnQzMhgBIAEoBUgAiAEBEhsKDm9wdGlvbmFsX2ludDY0GAIgASgDSAGI",
+            "AQESHAoPb3B0aW9uYWxfdWludDMyGAMgASgNSAKIAQESHAoPb3B0aW9uYWxf",
+            "dWludDY0GAQgASgESAOIAQESHAoPb3B0aW9uYWxfc2ludDMyGAUgASgRSASI",
+            "AQESHAoPb3B0aW9uYWxfc2ludDY0GAYgASgSSAWIAQESHQoQb3B0aW9uYWxf",
+            "Zml4ZWQzMhgHIAEoB0gGiAEBEh0KEG9wdGlvbmFsX2ZpeGVkNjQYCCABKAZI",
+            "B4gBARIeChFvcHRpb25hbF9zZml4ZWQzMhgJIAEoD0gIiAEBEh4KEW9wdGlv",
+            "bmFsX3NmaXhlZDY0GAogASgQSAmIAQESGwoOb3B0aW9uYWxfZmxvYXQYCyAB",
+            "KAJICogBARIcCg9vcHRpb25hbF9kb3VibGUYDCABKAFIC4gBARIaCg1vcHRp",
+            "b25hbF9ib29sGA0gASgISAyIAQESHAoPb3B0aW9uYWxfc3RyaW5nGA4gASgJ",
+            "SA2IAQESGwoOb3B0aW9uYWxfYnl0ZXMYDyABKAxIDogBARIeCg1vcHRpb25h",
+            "bF9jb3JkGBAgASgJQgIIAUgPiAEBElkKF29wdGlvbmFsX25lc3RlZF9tZXNz",
+            "YWdlGBIgASgLMjMucHJvdG9idWZfdW5pdHRlc3QuVGVzdFByb3RvM09wdGlv",
+            "bmFsLk5lc3RlZE1lc3NhZ2VIEIgBARJZChNsYXp5X25lc3RlZF9tZXNzYWdl",
+            "GBMgASgLMjMucHJvdG9idWZfdW5pdHRlc3QuVGVzdFByb3RvM09wdGlvbmFs",
+            "Lk5lc3RlZE1lc3NhZ2VCAigBSBGIAQESUwoUb3B0aW9uYWxfbmVzdGVkX2Vu",
+            "dW0YFSABKA4yMC5wcm90b2J1Zl91bml0dGVzdC5UZXN0UHJvdG8zT3B0aW9u",
+            "YWwuTmVzdGVkRW51bUgSiAEBEhYKDnNpbmd1bGFyX2ludDMyGBYgASgFEhYK",
+            "DnNpbmd1bGFyX2ludDY0GBcgASgDGicKDU5lc3RlZE1lc3NhZ2USDwoCYmIY",
+            "ASABKAVIAIgBAUIFCgNfYmIiSgoKTmVzdGVkRW51bRIPCgtVTlNQRUNJRklF",
+            "RBAAEgcKA0ZPTxABEgcKA0JBUhACEgcKA0JBWhADEhAKA05FRxD/////////",
+            "//8BQhEKD19vcHRpb25hbF9pbnQzMkIRCg9fb3B0aW9uYWxfaW50NjRCEgoQ",
+            "X29wdGlvbmFsX3VpbnQzMkISChBfb3B0aW9uYWxfdWludDY0QhIKEF9vcHRp",
+            "b25hbF9zaW50MzJCEgoQX29wdGlvbmFsX3NpbnQ2NEITChFfb3B0aW9uYWxf",
+            "Zml4ZWQzMkITChFfb3B0aW9uYWxfZml4ZWQ2NEIUChJfb3B0aW9uYWxfc2Zp",
+            "eGVkMzJCFAoSX29wdGlvbmFsX3NmaXhlZDY0QhEKD19vcHRpb25hbF9mbG9h",
+            "dEISChBfb3B0aW9uYWxfZG91YmxlQhAKDl9vcHRpb25hbF9ib29sQhIKEF9v",
+            "cHRpb25hbF9zdHJpbmdCEQoPX29wdGlvbmFsX2J5dGVzQhAKDl9vcHRpb25h",
+            "bF9jb3JkQhoKGF9vcHRpb25hbF9uZXN0ZWRfbWVzc2FnZUIWChRfbGF6eV9u",
+            "ZXN0ZWRfbWVzc2FnZUIXChVfb3B0aW9uYWxfbmVzdGVkX2VudW0iiQIKGVRl",
+            "c3RQcm90bzNPcHRpb25hbE1lc3NhZ2USUgoObmVzdGVkX21lc3NhZ2UYASAB",
+            "KAsyOi5wcm90b2J1Zl91bml0dGVzdC5UZXN0UHJvdG8zT3B0aW9uYWxNZXNz",
+            "YWdlLk5lc3RlZE1lc3NhZ2USYAoXb3B0aW9uYWxfbmVzdGVkX21lc3NhZ2UY",
+            "AiABKAsyOi5wcm90b2J1Zl91bml0dGVzdC5UZXN0UHJvdG8zT3B0aW9uYWxN",
+            "ZXNzYWdlLk5lc3RlZE1lc3NhZ2VIAIgBARoaCg1OZXN0ZWRNZXNzYWdlEgkK",
+            "AXMYASABKAlCGgoYX29wdGlvbmFsX25lc3RlZF9tZXNzYWdlIqkBChhQcm90",
+            "bzNPcHRpb25hbEV4dGVuc2lvbnMyPAoPZXh0X25vX29wdGlvbmFsEh8uZ29v",
+            "Z2xlLnByb3RvYnVmLk1lc3NhZ2VPcHRpb25zGIjN2akBIAEoBTJBChFleHRf",
+            "d2l0aF9vcHRpb25hbBIfLmdvb2dsZS5wcm90b2J1Zi5NZXNzYWdlT3B0aW9u",
+            "cxiJzdmpASABKAWIAQE6DMDozM0KCMjozM0KEEIlCiFjb20uZ29vZ2xlLnBy",
+            "b3RvYnVmLnRlc3RpbmcucHJvdG9QAWIGcHJvdG8z"));
      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
-          new pbr::FileDescriptor[] { },
+          new pbr::FileDescriptor[] { global::Google.Protobuf.Reflection.DescriptorReflection.Descriptor, },
          new pbr::GeneratedClrTypeInfo(null, null, new pbr::GeneratedClrTypeInfo[] {
            new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.TestProto3Optional), global::ProtobufUnittest.TestProto3Optional.Parser, new[]{ "OptionalInt32", "OptionalInt64", "OptionalUint32", "OptionalUint64", "OptionalSint32", "OptionalSint64", "OptionalFixed32", "OptionalFixed64", "OptionalSfixed32", "OptionalSfixed64", "OptionalFloat", "OptionalDouble", "OptionalBool", "OptionalString", "OptionalBytes", "OptionalCord", "OptionalNestedMessage", "LazyNestedMessage", "OptionalNestedEnum", "SingularInt32", "SingularInt64" }, new[]{ "OptionalInt32", "OptionalInt64", "OptionalUint32", "OptionalUint64", "OptionalSint32", "OptionalSint64", "OptionalFixed32", "OptionalFixed64", "OptionalSfixed32", "OptionalSfixed64", "OptionalFloat", "OptionalDouble", "OptionalBool", "OptionalString", "OptionalBytes", "OptionalCord", "OptionalNestedMessage", "LazyNestedMessage", "OptionalNestedEnum" }, new[]{ typeof(global::ProtobufUnittest.TestProto3Optional.Types.NestedEnum) }, null, new pbr::GeneratedClrTypeInfo[] { new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.TestProto3Optional.Types.NestedMessage), global::ProtobufUnittest.TestProto3Optional.Types.NestedMessage.Parser, new[]{ "Bb" }, new[]{ "Bb" }, null, null, null)}),
-            new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.TestProto3OptionalMessage), global::ProtobufUnittest.TestProto3OptionalMessage.Parser, new[]{ "NestedMessage", "OptionalNestedMessage" }, new[]{ "OptionalNestedMessage" }, null, null, new pbr::GeneratedClrTypeInfo[] { new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.TestProto3OptionalMessage.Types.NestedMessage), global::ProtobufUnittest.TestProto3OptionalMessage.Types.NestedMessage.Parser, new[]{ "S" }, null, null, null, null)})
+            new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.TestProto3OptionalMessage), global::ProtobufUnittest.TestProto3OptionalMessage.Parser, new[]{ "NestedMessage", "OptionalNestedMessage" }, new[]{ "OptionalNestedMessage" }, null, null, new pbr::GeneratedClrTypeInfo[] { new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.TestProto3OptionalMessage.Types.NestedMessage), global::ProtobufUnittest.TestProto3OptionalMessage.Types.NestedMessage.Parser, new[]{ "S" }, null, null, null, null)}),
+            new pbr::GeneratedClrTypeInfo(typeof(global::ProtobufUnittest.Proto3OptionalExtensions), global::ProtobufUnittest.Proto3OptionalExtensions.Parser, null, null, null, new pb::Extension[] { global::ProtobufUnittest.Proto3OptionalExtensions.Extensions.ExtNoOptional, global::ProtobufUnittest.Proto3OptionalExtensions.Extensions.ExtWithOptional }, null)
          }));
    }
    #endregion
@ -1789,6 +1794,153 @@ namespace ProtobufUnittest {

  }

+  public sealed partial class Proto3OptionalExtensions : pb::IMessage<Proto3OptionalExtensions>
+  #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE
+      , pb::IBufferMessage
+  #endif
+  {
+    private static readonly pb::MessageParser<Proto3OptionalExtensions> _parser = new pb::MessageParser<Proto3OptionalExtensions>(() => new Proto3OptionalExtensions());
+    private pb::UnknownFieldSet _unknownFields;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pb::MessageParser<Proto3OptionalExtensions> Parser { get { return _parser; } }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::ProtobufUnittest.UnittestProto3OptionalReflection.Descriptor.MessageTypes[2]; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Proto3OptionalExtensions() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Proto3OptionalExtensions(Proto3OptionalExtensions other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Proto3OptionalExtensions Clone() {
+      return new Proto3OptionalExtensions(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override bool Equals(object other) {
+      return Equals(other as Proto3OptionalExtensions);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool Equals(Proto3OptionalExtensions other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      return Equals(_unknownFields, other._unknownFields);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override int GetHashCode() {
+      int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
+      return hash;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void WriteTo(pb::CodedOutputStream output) {
+    #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE
+      output.WriteRawMessage(this);
+    #else
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
+    #endif
+    }
+
+    #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    void pb::IBufferMessage.InternalWriteTo(ref pb::WriteContext output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(ref output);
+      }
+    }
+    #endif
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int CalculateSize() {
+      int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
+      return size;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(Proto3OptionalExtensions other) {
+      if (other == null) {
+        return;
+      }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(pb::CodedInputStream input) {
+    #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE
+      input.ReadRawMessage(this);
+    #else
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
+            break;
+        }
+      }
+    #endif
+    }
+
+    #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    void pb::IBufferMessage.InternalMergeFrom(ref pb::ParseContext input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, ref input);
+            break;
+        }
+      }
+    }
+    #endif
+
+    #region Extensions
+    /// <summary>Container for extensions for other messages declared in the Proto3OptionalExtensions message type.</summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static partial class Extensions {
+      public static readonly pb::Extension<global::Google.Protobuf.Reflection.MessageOptions, int> ExtNoOptional =
+        new pb::Extension<global::Google.Protobuf.Reflection.MessageOptions, int>(355886728, pb::FieldCodec.ForInt32(2847093824, 0));
+      public static readonly pb::Extension<global::Google.Protobuf.Reflection.MessageOptions, int> ExtWithOptional =
+        new pb::Extension<global::Google.Protobuf.Reflection.MessageOptions, int>(355886729, pb::FieldCodec.ForInt32(2847093832, 0));
+    }
+    #endregion
+
+  }
+
  #endregion

 }
--- a/csharp/src/Google.Protobuf.Test/Buffers/ArrayBufferWriter.cs
+++ b/csharp/src/Google.Protobuf.Test/Buffers/ArrayBufferWriter.cs
@ -42,7 +42,7 @@ namespace Google.Protobuf.Buffers
    /// ArrayBufferWriter is originally from corefx, and has been contributed to Protobuf
    /// https://github.com/dotnet/runtime/blob/071da4c41aa808c949a773b92dca6f88de9d11f3/src/libraries/Common/src/System/Buffers/ArrayBufferWriter.cs
    /// </summary>
-    internal sealed class ArrayBufferWriter<T> : IBufferWriter<T>
+    internal sealed class TestArrayBufferWriter<T> : IBufferWriter<T>
    {
        private T[] _buffer;
        private int _index;
@ -50,10 +50,10 @@ namespace Google.Protobuf.Buffers
        private const int DefaultInitialBufferSize = 256;

        /// <summary>
-        /// Creates an instance of an <see cref="ArrayBufferWriter{T}"/>, in which data can be written to,
+        /// Creates an instance of an <see cref="TestArrayBufferWriter{T}"/>, in which data can be written to,
        /// with the default initial capacity.
        /// </summary>
-        public ArrayBufferWriter()
+        public TestArrayBufferWriter()
        {
            _buffer = new T[0];
            _index = 0;
@ -66,14 +66,14 @@ namespace Google.Protobuf.Buffers
        public int? MaxGrowBy { get; set; }

        /// <summary>
-        /// Creates an instance of an <see cref="ArrayBufferWriter{T}"/>, in which data can be written to,
+        /// Creates an instance of an <see cref="TestArrayBufferWriter{T}"/>, in which data can be written to,
        /// with an initial capacity specified.
        /// </summary>
        /// <param name="initialCapacity">The minimum capacity with which to initialize the underlying buffer.</param>
        /// <exception cref="ArgumentException">
        /// Thrown when <paramref name="initialCapacity"/> is not positive (i.e. less than or equal to 0).
        /// </exception>
-        public ArrayBufferWriter(int initialCapacity)
+        public TestArrayBufferWriter(int initialCapacity)
        {
            if (initialCapacity <= 0)
                throw new ArgumentException(nameof(initialCapacity));
@ -111,7 +111,7 @@ namespace Google.Protobuf.Buffers
        /// Clears the data written to the underlying buffer.
        /// </summary>
        /// <remarks>
-        /// You must clear the <see cref="ArrayBufferWriter{T}"/> before trying to re-use it.
+        /// You must clear the <see cref="TestArrayBufferWriter{T}"/> before trying to re-use it.
        /// </remarks>
        public void Clear()
        {
--- a/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
+++ b/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
@ -58,7 +58,7 @@ namespace Google.Protobuf
                Assert.AreEqual(data, rawOutput.ToArray());

                // IBufferWriter
-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                ctx.WriteUInt32((uint) value);
                ctx.Flush();
@ -77,7 +77,7 @@ namespace Google.Protobuf
                Assert.AreEqual(data, rawOutput.ToArray());

                // IBufferWriter
-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                ctx.WriteUInt64(value);
                ctx.Flush();
@ -100,7 +100,7 @@ namespace Google.Protobuf
                    output.Flush();
                    Assert.AreEqual(data, rawOutput.ToArray());

-                    var bufferWriter = new ArrayBufferWriter<byte>();
+                    var bufferWriter = new TestArrayBufferWriter<byte>();
                    bufferWriter.MaxGrowBy = bufferSize;
                    WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                    ctx.WriteUInt32((uint) value);
@ -115,7 +115,7 @@ namespace Google.Protobuf
                    output.Flush();
                    Assert.AreEqual(data, rawOutput.ToArray());

-                    var bufferWriter = new ArrayBufferWriter<byte>();
+                    var bufferWriter = new TestArrayBufferWriter<byte>();
                    bufferWriter.MaxGrowBy = bufferSize;
                    WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                    ctx.WriteUInt64(value);
@ -174,7 +174,7 @@ namespace Google.Protobuf
                output.Flush();
                Assert.AreEqual(data, rawOutput.ToArray());

-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                ctx.WriteFixed32(value);
                ctx.Flush();
@ -190,7 +190,7 @@ namespace Google.Protobuf
                output.Flush();
                Assert.AreEqual(data, rawOutput.ToArray());

-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                bufferWriter.MaxGrowBy = bufferSize;
                WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                ctx.WriteFixed32(value);
@ -212,7 +212,7 @@ namespace Google.Protobuf
                output.Flush();
                Assert.AreEqual(data, rawOutput.ToArray());

-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                ctx.WriteFixed64(value);
                ctx.Flush();
@ -228,7 +228,7 @@ namespace Google.Protobuf
                output.Flush();
                Assert.AreEqual(data, rawOutput.ToArray());

-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                bufferWriter.MaxGrowBy = blockSize;
                WriteContext.Initialize(bufferWriter, out WriteContext ctx);
                ctx.WriteFixed64(value);
@ -270,7 +270,7 @@ namespace Google.Protobuf
                output.Flush();
                Assert.AreEqual(rawBytes, rawOutput.ToArray());

-                var bufferWriter = new ArrayBufferWriter<byte>();
+                var bufferWriter = new TestArrayBufferWriter<byte>();
                bufferWriter.MaxGrowBy = blockSize;
                message.WriteTo(bufferWriter);
                Assert.AreEqual(rawBytes, bufferWriter.WrittenSpan.ToArray()); 
@ -292,7 +292,7 @@ namespace Google.Protobuf
            output.Flush();
            byte[] expectedBytes2 = expectedOutput.ToArray();

-            var bufferWriter = new ArrayBufferWriter<byte>();
+            var bufferWriter = new TestArrayBufferWriter<byte>();
            WriteContext.Initialize(bufferWriter, out WriteContext ctx);
            ctx.WriteMessage(message);
            ctx.Flush();
@ -519,7 +519,21 @@ namespace Google.Protobuf
        }

        [Test]
-        public void WriteStringsOfDifferentSizes()
+        public void WriteString_AsciiSmall_MaxUtf8SizeExceedsBuffer()
+        {
+            var buffer = new byte[5];
+            var output = new CodedOutputStream(buffer);
+            output.WriteString("ABC");
+
+            output.Flush();
+
+            // Verify written content
+            var input = new CodedInputStream(buffer);
+            Assert.AreEqual("ABC", input.ReadString());
+        }
+
+        [Test]
+        public void WriteStringsOfDifferentSizes_Ascii()
        {
            for (int i = 1; i <= 1024; i++)
            {
@ -540,5 +554,30 @@ namespace Google.Protobuf
                Assert.AreEqual(s, input.ReadString());
            }
        }
+
+        [Test]
+        public void WriteStringsOfDifferentSizes_Unicode()
+        {
+            for (int i = 1; i <= 1024; i++)
+            {
+                var buffer = new byte[4096];
+                var output = new CodedOutputStream(buffer);
+                var sb = new StringBuilder();
+                for (int j = 0; j < i; j++)
+                {
+                    char c = (char)((j % 10) + 10112);
+                    sb.Append(c.ToString()); // incrementing unicode numbers, repeating
+                }
+                var s = sb.ToString();
+                output.WriteString(s);
+
+                output.Flush();
+
+                // Verify written content
+                var input = new CodedInputStream(buffer);
+
+                Assert.AreEqual(s, input.ReadString());
+            }
+        }
    }
 }
--- a/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
+++ b/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFrameworks>net451;netcoreapp2.1</TargetFrameworks>
+    <TargetFrameworks>net451;netcoreapp2.1;net50</TargetFrameworks>
    <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
    <SignAssembly>true</SignAssembly>
    <IsPackable>False</IsPackable>
--- a/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
+++ b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
@ -551,9 +551,13 @@ namespace Google.Protobuf
        }

        [Test]
+        // Skip these test cases in .NET 5 because floating point parsing supports bigger values.
+        // These big values won't throw an error in the test.
+#if !NET5_0
        [TestCase("1.7977e308")]
        [TestCase("-1.7977e308")]
        [TestCase("1e309")]
+#endif
        [TestCase("1,0")]
        [TestCase("1.0.0")]
        [TestCase("+1")]
--- a/csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs
+++ b/csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs
@ -199,8 +199,12 @@ namespace Google.Protobuf
        [TestCase("1e-")]
        [TestCase("--")]
        [TestCase("--1")]
+        // Skip these test cases in .NET 5 because floating point parsing supports bigger values.
+        // These big values won't throw an error in the test.
+#if !NET5_0
        [TestCase("-1.7977e308")]
        [TestCase("1.7977e308")]
+#endif
        public void InvalidNumberValue(string json)
        {
            AssertThrowsAfter(json);
--- a/csharp/src/Google.Protobuf.Test/LegacyGeneratedCodeTest.cs
+++ b/csharp/src/Google.Protobuf.Test/LegacyGeneratedCodeTest.cs
@ -141,7 +141,7 @@ namespace Google.Protobuf
            };
            var exception = Assert.Throws<InvalidProtocolBufferException>(() =>
            {
-                WriteContext.Initialize(new ArrayBufferWriter<byte>(), out WriteContext writeCtx);
+                WriteContext.Initialize(new TestArrayBufferWriter<byte>(), out WriteContext writeCtx);
                ((IBufferMessage)message).InternalWriteTo(ref writeCtx);
            });
            Assert.AreEqual($"Message {typeof(LegacyGeneratedCodeMessageA).Name} doesn't provide the generated method that enables WriteContext-based serialization. You might need to regenerate the generated protobuf code.", exception.Message);
--- a/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
+++ b/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
@ -83,7 +83,7 @@ namespace Google.Protobuf
            var bytes = message.ToByteArray();

            // also serialize using IBufferWriter and check it leads to the same data
-            var bufferWriter = new ArrayBufferWriter<byte>();
+            var bufferWriter = new TestArrayBufferWriter<byte>();
            message.WriteTo(bufferWriter);
            Assert.AreEqual(bytes, bufferWriter.WrittenSpan.ToArray(), "Both serialization approaches need to result in the same data.");

@ -112,7 +112,7 @@ namespace Google.Protobuf
            Assert.AreEqual(message.CalculateSize(), bytes.Length);

            // serialize using IBufferWriter and check it leads to the same output
-            var bufferWriter = new ArrayBufferWriter<byte>();
+            var bufferWriter = new TestArrayBufferWriter<byte>();
            message.WriteTo(bufferWriter);
            Assert.AreEqual(bytes, bufferWriter.WrittenSpan.ToArray());

@ -124,7 +124,7 @@ namespace Google.Protobuf
            // test for different IBufferWriter.GetSpan() segment sizes
            for (int blockSize = 1; blockSize < 256; blockSize *= 2)
            {
-                var segmentedBufferWriter = new ArrayBufferWriter<byte>();
+                var segmentedBufferWriter = new TestArrayBufferWriter<byte>();
                segmentedBufferWriter.MaxGrowBy = blockSize;
                message.WriteTo(segmentedBufferWriter);
                Assert.AreEqual(bytes, segmentedBufferWriter.WrittenSpan.ToArray());
--- a/csharp/src/Google.Protobuf.Test/testprotos.pb
+++ b/csharp/src/Google.Protobuf.Test/testprotos.pb
--- a/csharp/src/Google.Protobuf/Google.Protobuf.csproj
+++ b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <Description>C# runtime library for Protocol Buffers - Google's data interchange format.</Description>
@ -8,7 +8,7 @@
    <!-- C# 7.2 is required for Span/BufferWriter/ReadOnlySequence -->
    <LangVersion>7.2</LangVersion>
    <Authors>Google Inc.</Authors>
-    <TargetFrameworks>netstandard1.1;netstandard2.0;net45</TargetFrameworks>
+    <TargetFrameworks>netstandard1.1;netstandard2.0;net45;net50</TargetFrameworks>
    <GenerateDocumentationFile>true</GenerateDocumentationFile>
    <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
    <SignAssembly>true</SignAssembly>
@ -27,15 +27,23 @@
    <DefineConstants>$(DefineConstants);GOOGLE_PROTOBUF_SUPPORT_FAST_STRING</DefineConstants>
  </PropertyGroup>

+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net50' ">
+    <DefineConstants>$(DefineConstants);GOOGLE_PROTOBUF_SUPPORT_FAST_STRING;GOOGLE_PROTOBUF_SIMD</DefineConstants>
+  </PropertyGroup>
+
  <ItemGroup>
-    <PackageReference Include="System.Memory" Version="4.5.3"/>
    <PackageReference Include="Microsoft.SourceLink.GitHub" PrivateAssets="All" Version="1.0.0"/>
    <!-- Needed for the net45 build to work on Unix. See https://github.com/dotnet/designs/pull/33 -->
    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0"/>
  </ItemGroup>

-  <!-- Needed for netcoreapp2.1 to work correctly. .NET is not able to load the assembly without this -->
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net45' OR '$(TargetFramework)' == 'netstandard1.1' ">
+    <PackageReference Include="System.Memory" Version="4.5.3"/>
+  </ItemGroup>
+
  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
+    <PackageReference Include="System.Memory" Version="4.5.3"/>
+    <!-- Needed for netcoreapp2.1 to work correctly. .NET is not able to load the assembly without this -->
    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.5.2"/>
  </ItemGroup>

--- a/csharp/src/Google.Protobuf/Reflection/Descriptor.cs
+++ b/csharp/src/Google.Protobuf/Reflection/Descriptor.cs
@ -107,57 +107,58 @@ namespace Google.Protobuf.Reflection {
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            "CzIkLmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uIjoKDE9w",
            "dGltaXplTW9kZRIJCgVTUEVFRBABEg0KCUNPREVfU0laRRACEhAKDExJVEVf",
-            "UlVOVElNRRADKgkI6AcQgICAgAJKBAgmECci8gEKDk1lc3NhZ2VPcHRpb25z",
+            "UlVOVElNRRADKgkI6AcQgICAgAJKBAgmECcihAIKDk1lc3NhZ2VPcHRpb25z",
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            "b19zdGFuZGFyZF9kZXNjcmlwdG9yX2FjY2Vzc29yGAIgASgIOgVmYWxzZRIZ",
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            "QwoUdW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3Rv",
-            "YnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAkoECAgQCUoECAkQ",
-            "CiKeAwoMRmllbGRPcHRpb25zEjoKBWN0eXBlGAEgASgOMiMuZ29vZ2xlLnBy",
-            "b3RvYnVmLkZpZWxkT3B0aW9ucy5DVHlwZToGU1RSSU5HEg4KBnBhY2tlZBgC",
-            "IAEoCBI/CgZqc3R5cGUYBiABKA4yJC5nb29nbGUucHJvdG9idWYuRmllbGRP",
-            "cHRpb25zLkpTVHlwZToJSlNfTk9STUFMEhMKBGxhenkYBSABKAg6BWZhbHNl",
-            "EhkKCmRlcHJlY2F0ZWQYAyABKAg6BWZhbHNlEhMKBHdlYWsYCiABKAg6BWZh",
-            "bHNlEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5w",
-            "cm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uIi8KBUNUeXBlEgoKBlNUUklO",
-            "RxAAEggKBENPUkQQARIQCgxTVFJJTkdfUElFQ0UQAiI1CgZKU1R5cGUSDQoJ",
-            "SlNfTk9STUFMEAASDQoJSlNfU1RSSU5HEAESDQoJSlNfTlVNQkVSEAIqCQjo",
-            "BxCAgICAAkoECAQQBSJeCgxPbmVvZk9wdGlvbnMSQwoUdW5pbnRlcnByZXRl",
-            "ZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0",
-            "ZWRPcHRpb24qCQjoBxCAgICAAiKTAQoLRW51bU9wdGlvbnMSEwoLYWxsb3df",
-            "YWxpYXMYAiABKAgSGQoKZGVwcmVjYXRlZBgDIAEoCDoFZmFsc2USQwoUdW5p",
-            "bnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVu",
-            "aW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAkoECAUQBiJ9ChBFbnVtVmFs",
-            "dWVPcHRpb25zEhkKCmRlcHJlY2F0ZWQYASABKAg6BWZhbHNlEkMKFHVuaW50",
-            "ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5Vbmlu",
-            "dGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIiewoOU2VydmljZU9wdGlvbnMS",
-            "GQoKZGVwcmVjYXRlZBghIAEoCDoFZmFsc2USQwoUdW5pbnRlcnByZXRlZF9v",
-            "cHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0ZWRP",
-            "cHRpb24qCQjoBxCAgICAAiKtAgoNTWV0aG9kT3B0aW9ucxIZCgpkZXByZWNh",
-            "dGVkGCEgASgIOgVmYWxzZRJfChFpZGVtcG90ZW5jeV9sZXZlbBgiIAEoDjIv",
-            "Lmdvb2dsZS5wcm90b2J1Zi5NZXRob2RPcHRpb25zLklkZW1wb3RlbmN5TGV2",
-            "ZWw6E0lERU1QT1RFTkNZX1VOS05PV04SQwoUdW5pbnRlcnByZXRlZF9vcHRp",
-            "b24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0ZWRPcHRp",
-            "b24iUAoQSWRlbXBvdGVuY3lMZXZlbBIXChNJREVNUE9URU5DWV9VTktOT1dO",
-            "EAASEwoPTk9fU0lERV9FRkZFQ1RTEAESDgoKSURFTVBPVEVOVBACKgkI6AcQ",
-            "gICAgAIingIKE1VuaW50ZXJwcmV0ZWRPcHRpb24SOwoEbmFtZRgCIAMoCzIt",
-            "Lmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uLk5hbWVQYXJ0",
-            "EhgKEGlkZW50aWZpZXJfdmFsdWUYAyABKAkSGgoScG9zaXRpdmVfaW50X3Zh",
-            "bHVlGAQgASgEEhoKEm5lZ2F0aXZlX2ludF92YWx1ZRgFIAEoAxIUCgxkb3Vi",
-            "bGVfdmFsdWUYBiABKAESFAoMc3RyaW5nX3ZhbHVlGAcgASgMEhcKD2FnZ3Jl",
-            "Z2F0ZV92YWx1ZRgIIAEoCRozCghOYW1lUGFydBIRCgluYW1lX3BhcnQYASAC",
-            "KAkSFAoMaXNfZXh0ZW5zaW9uGAIgAigIItUBCg5Tb3VyY2VDb2RlSW5mbxI6",
-            "Cghsb2NhdGlvbhgBIAMoCzIoLmdvb2dsZS5wcm90b2J1Zi5Tb3VyY2VDb2Rl",
-            "SW5mby5Mb2NhdGlvbhqGAQoITG9jYXRpb24SEAoEcGF0aBgBIAMoBUICEAES",
-            "EAoEc3BhbhgCIAMoBUICEAESGAoQbGVhZGluZ19jb21tZW50cxgDIAEoCRIZ",
-            "ChF0cmFpbGluZ19jb21tZW50cxgEIAEoCRIhChlsZWFkaW5nX2RldGFjaGVk",
-            "X2NvbW1lbnRzGAYgAygJIqcBChFHZW5lcmF0ZWRDb2RlSW5mbxJBCgphbm5v",
-            "dGF0aW9uGAEgAygLMi0uZ29vZ2xlLnByb3RvYnVmLkdlbmVyYXRlZENvZGVJ",
-            "bmZvLkFubm90YXRpb24aTwoKQW5ub3RhdGlvbhIQCgRwYXRoGAEgAygFQgIQ",
-            "ARITCgtzb3VyY2VfZmlsZRgCIAEoCRINCgViZWdpbhgDIAEoBRILCgNlbmQY",
-            "BCABKAVCfgoTY29tLmdvb2dsZS5wcm90b2J1ZkIQRGVzY3JpcHRvclByb3Rv",
-            "c0gBWi1nb29nbGUuZ29sYW5nLm9yZy9wcm90b2J1Zi90eXBlcy9kZXNjcmlw",
-            "dG9ycGL4AQGiAgNHUEKqAhpHb29nbGUuUHJvdG9idWYuUmVmbGVjdGlvbg=="));
+            "YnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAkoECAQQBUoECAUQ",
+            "BkoECAYQB0oECAgQCUoECAkQCiKeAwoMRmllbGRPcHRpb25zEjoKBWN0eXBl",
+            "GAEgASgOMiMuZ29vZ2xlLnByb3RvYnVmLkZpZWxkT3B0aW9ucy5DVHlwZToG",
+            "U1RSSU5HEg4KBnBhY2tlZBgCIAEoCBI/CgZqc3R5cGUYBiABKA4yJC5nb29n",
+            "bGUucHJvdG9idWYuRmllbGRPcHRpb25zLkpTVHlwZToJSlNfTk9STUFMEhMK",
+            "BGxhenkYBSABKAg6BWZhbHNlEhkKCmRlcHJlY2F0ZWQYAyABKAg6BWZhbHNl",
+            "EhMKBHdlYWsYCiABKAg6BWZhbHNlEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9u",
+            "GOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9u",
+            "Ii8KBUNUeXBlEgoKBlNUUklORxAAEggKBENPUkQQARIQCgxTVFJJTkdfUElF",
+            "Q0UQAiI1CgZKU1R5cGUSDQoJSlNfTk9STUFMEAASDQoJSlNfU1RSSU5HEAES",
+            "DQoJSlNfTlVNQkVSEAIqCQjoBxCAgICAAkoECAQQBSJeCgxPbmVvZk9wdGlv",
+            "bnMSQwoUdW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnBy",
+            "b3RvYnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAiKTAQoLRW51",
+            "bU9wdGlvbnMSEwoLYWxsb3dfYWxpYXMYAiABKAgSGQoKZGVwcmVjYXRlZBgD",
+            "IAEoCDoFZmFsc2USQwoUdW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQu",
+            "Z29vZ2xlLnByb3RvYnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICA",
+            "AkoECAUQBiJ9ChBFbnVtVmFsdWVPcHRpb25zEhkKCmRlcHJlY2F0ZWQYASAB",
+            "KAg6BWZhbHNlEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdv",
+            "b2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIi",
+            "ewoOU2VydmljZU9wdGlvbnMSGQoKZGVwcmVjYXRlZBghIAEoCDoFZmFsc2US",
+            "QwoUdW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3Rv",
+            "YnVmLlVuaW50ZXJwcmV0ZWRPcHRpb24qCQjoBxCAgICAAiKtAgoNTWV0aG9k",
+            "T3B0aW9ucxIZCgpkZXByZWNhdGVkGCEgASgIOgVmYWxzZRJfChFpZGVtcG90",
+            "ZW5jeV9sZXZlbBgiIAEoDjIvLmdvb2dsZS5wcm90b2J1Zi5NZXRob2RPcHRp",
+            "b25zLklkZW1wb3RlbmN5TGV2ZWw6E0lERU1QT1RFTkNZX1VOS05PV04SQwoU",
+            "dW5pbnRlcnByZXRlZF9vcHRpb24Y5wcgAygLMiQuZ29vZ2xlLnByb3RvYnVm",
+            "LlVuaW50ZXJwcmV0ZWRPcHRpb24iUAoQSWRlbXBvdGVuY3lMZXZlbBIXChNJ",
+            "REVNUE9URU5DWV9VTktOT1dOEAASEwoPTk9fU0lERV9FRkZFQ1RTEAESDgoK",
+            "SURFTVBPVEVOVBACKgkI6AcQgICAgAIingIKE1VuaW50ZXJwcmV0ZWRPcHRp",
+            "b24SOwoEbmFtZRgCIAMoCzItLmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJl",
+            "dGVkT3B0aW9uLk5hbWVQYXJ0EhgKEGlkZW50aWZpZXJfdmFsdWUYAyABKAkS",
+            "GgoScG9zaXRpdmVfaW50X3ZhbHVlGAQgASgEEhoKEm5lZ2F0aXZlX2ludF92",
+            "YWx1ZRgFIAEoAxIUCgxkb3VibGVfdmFsdWUYBiABKAESFAoMc3RyaW5nX3Zh",
+            "bHVlGAcgASgMEhcKD2FnZ3JlZ2F0ZV92YWx1ZRgIIAEoCRozCghOYW1lUGFy",
+            "dBIRCgluYW1lX3BhcnQYASACKAkSFAoMaXNfZXh0ZW5zaW9uGAIgAigIItUB",
+            "Cg5Tb3VyY2VDb2RlSW5mbxI6Cghsb2NhdGlvbhgBIAMoCzIoLmdvb2dsZS5w",
+            "cm90b2J1Zi5Tb3VyY2VDb2RlSW5mby5Mb2NhdGlvbhqGAQoITG9jYXRpb24S",
+            "EAoEcGF0aBgBIAMoBUICEAESEAoEc3BhbhgCIAMoBUICEAESGAoQbGVhZGlu",
+            "Z19jb21tZW50cxgDIAEoCRIZChF0cmFpbGluZ19jb21tZW50cxgEIAEoCRIh",
+            "ChlsZWFkaW5nX2RldGFjaGVkX2NvbW1lbnRzGAYgAygJIqcBChFHZW5lcmF0",
+            "ZWRDb2RlSW5mbxJBCgphbm5vdGF0aW9uGAEgAygLMi0uZ29vZ2xlLnByb3Rv",
+            "YnVmLkdlbmVyYXRlZENvZGVJbmZvLkFubm90YXRpb24aTwoKQW5ub3RhdGlv",
+            "bhIQCgRwYXRoGAEgAygFQgIQARITCgtzb3VyY2VfZmlsZRgCIAEoCRINCgVi",
+            "ZWdpbhgDIAEoBRILCgNlbmQYBCABKAVCfgoTY29tLmdvb2dsZS5wcm90b2J1",
+            "ZkIQRGVzY3JpcHRvclByb3Rvc0gBWi1nb29nbGUuZ29sYW5nLm9yZy9wcm90",
+            "b2J1Zi90eXBlcy9kZXNjcmlwdG9ycGL4AQGiAgNHUEKqAhpHb29nbGUuUHJv",
+            "dG9idWYuUmVmbGVjdGlvbg=="));
      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
          new pbr::FileDescriptor[] { },
          new pbr::GeneratedClrTypeInfo(null, null, new pbr::GeneratedClrTypeInfo[] {
@ -4795,11 +4796,11 @@ namespace Google.Protobuf.Reflection {

    private string javaOuterClassname_;
    /// <summary>
-    /// If set, all the classes from the .proto file are wrapped in a single
-    /// outer class with the given name.  This applies to both Proto1
-    /// (equivalent to the old "--one_java_file" option) and Proto2 (where
-    /// a .proto always translates to a single class, but you may want to
-    /// explicitly choose the class name).
+    /// Controls the name of the wrapper Java class generated for the .proto file.
+    /// That class will always contain the .proto file's getDescriptor() method as
+    /// well as any top-level extensions defined in the .proto file.
+    /// If java_multiple_files is disabled, then all the other classes from the
+    /// .proto file will be nested inside the single wrapper outer class.
    /// </summary>
    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
    public string JavaOuterClassname {
@ -4825,10 +4826,10 @@ namespace Google.Protobuf.Reflection {

    private bool javaMultipleFiles_;
    /// <summary>
-    /// If set true, then the Java code generator will generate a separate .java
+    /// If enabled, then the Java code generator will generate a separate .java
    /// file for each top-level message, enum, and service defined in the .proto
-    /// file.  Thus, these types will *not* be nested inside the outer class
-    /// named by java_outer_classname.  However, the outer class will still be
+    /// file.  Thus, these types will *not* be nested inside the wrapper class
+    /// named by java_outer_classname.  However, the wrapper class will still be
    /// generated to contain the file's getDescriptor() method as well as any
    /// top-level extensions defined in the file.
    /// </summary>
--- a/csharp/src/Google.Protobuf/WritingPrimitives.cs
+++ b/csharp/src/Google.Protobuf/WritingPrimitives.cs
@ -32,8 +32,14 @@

 using System;
 using System.Buffers.Binary;
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+#if GOOGLE_PROTOBUF_SIMD
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.Arm;
+using System.Runtime.Intrinsics.X86;
+#endif
 using System.Security;
 using System.Text;

@ -45,8 +51,11 @@ namespace Google.Protobuf
    [SecuritySafeCritical]
    internal static class WritingPrimitives
    {
-        // "Local" copy of Encoding.UTF8, for efficiency. (Yes, it makes a difference.)
-        internal static readonly Encoding Utf8Encoding = Encoding.UTF8;
+#if NET5_0
+        internal static Encoding Utf8Encoding => Encoding.UTF8; // allows JIT to devirtualize
+#else
+        internal static readonly Encoding Utf8Encoding = Encoding.UTF8; // "Local" copy of Encoding.UTF8, for efficiency. (Yes, it makes a difference.)
+#endif

        #region Writing of values (not including tags)

@ -186,11 +195,7 @@ namespace Google.Protobuf
            {
                if (length == value.Length) // Must be all ASCII...
                {
-                    for (int i = 0; i < length; i++)
-                    {
-                        buffer[state.position + i] = (byte)value[i];
-                    }
-                    state.position += length;
+                    WriteAsciiStringToBuffer(buffer, ref state, value, length);
                }
                else
                {
@ -208,6 +213,104 @@ namespace Google.Protobuf
            }
        }

+        // Calling this method with non-ASCII content will break.
+        // Content must be verified to be all ASCII before using this method.
+        private static void WriteAsciiStringToBuffer(Span<byte> buffer, ref WriterInternalState state, string value, int length)
+        {
+            ref char sourceChars = ref MemoryMarshal.GetReference(value.AsSpan());
+            ref byte destinationBytes = ref MemoryMarshal.GetReference(buffer.Slice(state.position));
+
+            int currentIndex = 0;
+            // If 64bit, process 4 chars at a time.
+            // The logic inside this check will be elided by JIT in 32bit programs.
+            if (IntPtr.Size == 8)
+            {
+                // Need at least 4 chars available to use this optimization. 
+                if (length >= 4)
+                {
+                    ref byte sourceBytes = ref Unsafe.As<char, byte>(ref sourceChars);
+
+                    // Process 4 chars at a time until there are less than 4 remaining.
+                    // We already know all characters are ASCII so there is no need to validate the source.
+                    int lastIndexWhereCanReadFourChars = value.Length - 4;
+                    do
+                    {
+                        NarrowFourUtf16CharsToAsciiAndWriteToBuffer(
+                            ref Unsafe.AddByteOffset(ref destinationBytes, (IntPtr)currentIndex),
+                            Unsafe.ReadUnaligned<ulong>(ref Unsafe.AddByteOffset(ref sourceBytes, (IntPtr)(currentIndex * 2))));
+
+                    } while ((currentIndex += 4) <= lastIndexWhereCanReadFourChars);
+                }
+            }
+
+            // Process any remaining, 1 char at a time.
+            // Avoid bounds checking with ref + Unsafe
+            for (; currentIndex < length; currentIndex++)
+            {
+                Unsafe.AddByteOffset(ref destinationBytes, (IntPtr)currentIndex) = (byte)Unsafe.AddByteOffset(ref sourceChars, (IntPtr)(currentIndex * 2));
+            }
+
+            state.position += length;
+        }
+
+        // Copied with permission from https://github.com/dotnet/runtime/blob/1cdafd27e4afd2c916af5df949c13f8b373c4335/src/libraries/System.Private.CoreLib/src/System/Text/ASCIIUtility.cs#L1119-L1171
+        //
+        /// <summary>
+        /// Given a QWORD which represents a buffer of 4 ASCII chars in machine-endian order,
+        /// narrows each WORD to a BYTE, then writes the 4-byte result to the output buffer
+        /// also in machine-endian order.
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static void NarrowFourUtf16CharsToAsciiAndWriteToBuffer(ref byte outputBuffer, ulong value)
+        {
+#if GOOGLE_PROTOBUF_SIMD
+            if (Sse2.X64.IsSupported)
+            {
+                // Narrows a vector of words [ w0 w1 w2 w3 ] to a vector of bytes
+                // [ b0 b1 b2 b3 b0 b1 b2 b3 ], then writes 4 bytes (32 bits) to the destination.
+
+                Vector128<short> vecWide = Sse2.X64.ConvertScalarToVector128UInt64(value).AsInt16();
+                Vector128<uint> vecNarrow = Sse2.PackUnsignedSaturate(vecWide, vecWide).AsUInt32();
+                Unsafe.WriteUnaligned<uint>(ref outputBuffer, Sse2.ConvertToUInt32(vecNarrow));
+            }
+            else if (AdvSimd.IsSupported)
+            {
+                // Narrows a vector of words [ w0 w1 w2 w3 ] to a vector of bytes
+                // [ b0 b1 b2 b3 * * * * ], then writes 4 bytes (32 bits) to the destination.
+
+                Vector128<short> vecWide = Vector128.CreateScalarUnsafe(value).AsInt16();
+                Vector64<byte> lower = AdvSimd.ExtractNarrowingSaturateUnsignedLower(vecWide);
+                Unsafe.WriteUnaligned<uint>(ref outputBuffer, lower.AsUInt32().ToScalar());
+            }
+            else
+#endif
+            {
+                // Fallback to non-SIMD approach when SIMD is not available.
+                // This could happen either because the APIs are not available, or hardware doesn't support it.
+                // Processing 4 chars at a time in this fallback is still faster than casting one char at a time.
+                if (BitConverter.IsLittleEndian)
+                {
+                    outputBuffer = (byte)value;
+                    value >>= 16;
+                    Unsafe.Add(ref outputBuffer, 1) = (byte)value;
+                    value >>= 16;
+                    Unsafe.Add(ref outputBuffer, 2) = (byte)value;
+                    value >>= 16;
+                    Unsafe.Add(ref outputBuffer, 3) = (byte)value;
+                }
+                else
+                {
+                    Unsafe.Add(ref outputBuffer, 3) = (byte)value;
+                    value >>= 16;
+                    Unsafe.Add(ref outputBuffer, 2) = (byte)value;
+                    value >>= 16;
+                    Unsafe.Add(ref outputBuffer, 1) = (byte)value;
+                    value >>= 16;
+                    outputBuffer = (byte)value;
+                }
+            }
+        }
+
        private static int WriteStringToBuffer(Span<byte> buffer, ref WriterInternalState state, string value)
        {
 #if NETSTANDARD1_1
--- a/docs/implementing_proto3_presence.md
+++ b/docs/implementing_proto3_presence.md
@ -261,7 +261,7 @@ bool FieldHasPresence(const google::protobuf::FieldDescriptor* field) {
 Old:

 ```c++
-bool FieldIsInOneof(const google::protobuf::FielDescriptor* field) {
+bool FieldIsInOneof(const google::protobuf::FieldDescriptor* field) {
  return field->containing_oneof() != nullptr;
 }
 ```
@ -269,7 +269,7 @@ bool FieldIsInOneof(const google::protobuf::FielDescriptor* field) {
 New:

 ```c++
-bool FieldIsInOneof(const google::protobuf::FielDescriptor* field) {
+bool FieldIsInOneof(const google::protobuf::FieldDescriptor* field) {
  // real_containing_oneof() returns nullptr for synthetic oneofs.
  return field->real_containing_oneof() != nullptr;
 }
--- a/docs/jvm_aot.md
+++ b/docs/jvm_aot.md
@ -0,0 +1,18 @@
+# Ahead Of Time (AOT) compilation for the Java Virtual Machine (JVM)"
+
+Ahead Of Time (AOT) compilation build tools such as those provided by [GraalVM's `native-image`](https://www.graalvm.org/reference-manual/native-image/) can require some configuration when using protobuf.
+Protobuf for the JVM uses reflection and some of its target classes are not possible to determine in advance.
+Historically, there were good reasons to use reflection based on APIs that were published effectively requiring them, and this situation is unlikely to change.
+
+[The Lite version of protobuf for the JVM](https://github.com/protocolbuffers/protobuf/blob/master/java/lite.md)
+avoids reflection and may be better suited for use with AOT compilation tooling. This Lite version was originally targeted for use on Android which has similar AOT compilation
+goals as GraalVM's native-image tool.
+
+## GraalVM native-image
+
+This section addresses GraalVM's `native-image` configuration specifically as this AOT compilation tool due to its popularity. The `native-image` tool can be configured
+with respect to: the [Java Native Interface](https://en.wikipedia.org/wiki/Java_Native_Interface) (JNI), http proxying, reflection, and other resources. While these
+considerations can be manually declared as JSON files, we recommend that a JVM application is exercised along with 
+[the assisted configuration agent](https://www.graalvm.org/reference-manual/native-image/BuildConfiguration/#assisted-configuration-of-native-image-builds). The agent
+will generate files that you can then subsequently point at when invoking `native-image`. We recommend that the generated files are retained with a project's source
+code.
--- a/docs/options.md
+++ b/docs/options.md
@ -263,8 +263,16 @@ with info about your project (name and website) so we can add an entry for you.

 1. Protoc-gen-psql
   * Website: https://github.com/Intrinsec/protoc-gen-psql
-   * Extension: 1091
+   * Extension: 1091-1101

 1. Protoc-gen-sanitize
   * Website: https://github.com/Intrinsec/protoc-gen-sanitize
-   * Extension: 1092
+   * Extension: 1102-1106
+
+1. Coach Client Connect (planned release in March 2021)
+   * Website: https://www.coachclientconnect.com
+   * Extension: 1107
+
+1. Kratos API Errors
+   * Website: https://go-kratos.dev
+   * Extension: 1108
--- a/docs/third_party.md
+++ b/docs/third_party.md
@ -11,6 +11,7 @@ These are projects we know about implementing Protocol Buffers for other program
 * Action Script: https://code.google.com/p/protoc-gen-as3/
 * Action Script: https://github.com/matrix3d/JProtoc
 * Action Script: https://github.com/zhongfq/protobuf-as3/
+* Ada: https://github.com/reznikmm/protobuf
 * C: https://github.com/protobuf-c/protobuf-c
 * C: http://koti.kapsi.fi/jpa/nanopb/
 * C: https://github.com/cloudwu/pbc/
@ -101,7 +102,6 @@ These are projects we know about implementing Protocol Buffers for other program
 * Solidity: https://github.com/celer-network/pb3-gen-sol
 * Swift: https://github.com/alexeyxo/protobuf-swift
 * Swift: https://github.com/apple/swift-protobuf/
-* Typescript: https://github.com/y3llowcake/protoc-gen-ts
 * Vala: https://launchpad.net/protobuf-vala
 * Visual Basic: http://code.google.com/p/protobuf-net/

--- a/global.json
+++ b/global.json
@ -1,6 +1,6 @@
 {
  "sdk": {
-    "version": "3.0.100",
+    "version": "5.0.102",
    "rollForward": "latestMinor"
  }
 }
--- a/java/README.md
+++ b/java/README.md
@ -23,7 +23,7 @@ If you are using Maven, use the following:
 <dependency>
  <groupId>com.google.protobuf</groupId>
  <artifactId>protobuf-java</artifactId>
-  <version>3.11.0</version>
+  <version>3.15.3</version>
 </dependency>
 ```

@ -37,7 +37,7 @@ protobuf-java-util package:
 <dependency>
  <groupId>com.google.protobuf</groupId>
  <artifactId>protobuf-java-util</artifactId>
-  <version>3.11.0</version>
+  <version>3.15.3</version>
 </dependency>
 ```

--- a/java/core/BUILD
+++ b/java/core/BUILD
@ -85,6 +85,7 @@ LITE_SRCS = [
    "src/main/java/com/google/protobuf/UnknownFieldSetLite.java",
    "src/main/java/com/google/protobuf/UnknownFieldSetLiteSchema.java",
    "src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java",
+    "src/main/java/com/google/protobuf/UnsafeByteOperations.java",
    "src/main/java/com/google/protobuf/UnsafeUtil.java",
    "src/main/java/com/google/protobuf/Utf8.java",
    "src/main/java/com/google/protobuf/WireFormat.java",
--- a/java/core/src/main/java/com/google/protobuf/ByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/ByteString.java
@ -1043,8 +1043,10 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    }

    /**
-     * Creates a byte string. Its size is the current size of this output stream and its output has
-     * been copied to it.
+     * Creates a byte string with the size and contents of this output stream. This does not create
+     * a new copy of the underlying bytes. If the stream size grows dynamically, the runtime is
+     * O(log n) in respect to the number of bytes written to the {@link Output}. If the stream size
+     * stays within the initial capacity, the runtime is O(1).
     *
     * @return the current contents of this output stream, as a byte string.
     */
--- a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
@ -1185,6 +1185,9 @@ public abstract class CodedInputStream {
        throw InvalidProtocolBufferException.negativeSize();
      }
      byteLimit += getTotalBytesRead();
+      if (byteLimit < 0) {
+        throw InvalidProtocolBufferException.parseFailure();
+      }
      final int oldLimit = currentLimit;
      if (byteLimit > oldLimit) {
        throw InvalidProtocolBufferException.truncatedMessage();
@ -2055,6 +2058,44 @@ public abstract class CodedInputStream {
      totalBytesRetired = 0;
    }

+    /*
+     * The following wrapper methods exist so that InvalidProtocolBufferExceptions thrown by the
+     * InputStream can be differentiated from ones thrown by CodedInputStream itself. Each call to
+     * an InputStream method that can throw IOException must be wrapped like this. We do this
+     * because we sometimes need to modify IPBE instances after they are thrown far away from where
+     * they are thrown (ex. to add unfinished messages) and we use this signal elsewhere in the
+     * exception catch chain to know when to perform these operations directly or to wrap the
+     * exception in their own IPBE so the extra information can be communicated without trampling
+     * downstream information.
+     */
+    private static int read(InputStream input, byte[] data, int offset, int length)
+        throws IOException {
+      try {
+        return input.read(data, offset, length);
+      } catch (InvalidProtocolBufferException e) {
+        e.setThrownFromInputStream();
+        throw e;
+      }
+    }
+
+    private static long skip(InputStream input, long length) throws IOException {
+      try {
+        return input.skip(length);
+      } catch (InvalidProtocolBufferException e) {
+        e.setThrownFromInputStream();
+        throw e;
+      }
+    }
+
+    private static int available(InputStream input) throws IOException {
+      try {
+        return input.available();
+      } catch (InvalidProtocolBufferException e) {
+        e.setThrownFromInputStream();
+        throw e;
+      }
+    }
+
    @Override
    public int readTag() throws IOException {
      if (isAtEnd()) {
@ -2783,7 +2824,8 @@ public abstract class CodedInputStream {

      // Here we should refill the buffer as many bytes as possible.
      int bytesRead =
-          input.read(
+          read(
+              input,
              buffer,
              bufferSize,
              Math.min(
@ -2905,7 +2947,7 @@ public abstract class CodedInputStream {
      // Determine the number of bytes we need to read from the input stream.
      int sizeLeft = size - bufferedBytes;
      // TODO(nathanmittler): Consider using a value larger than DEFAULT_BUFFER_SIZE.
-      if (sizeLeft < DEFAULT_BUFFER_SIZE || sizeLeft <= input.available()) {
+      if (sizeLeft < DEFAULT_BUFFER_SIZE || sizeLeft <= available(input)) {
        // Either the bytes we need are known to be available, or the required buffer is
        // within an allowed threshold - go ahead and allocate the buffer now.
        final byte[] bytes = new byte[size];
@ -2919,7 +2961,7 @@ public abstract class CodedInputStream {
        // Fill the remaining bytes from the input stream.
        int tempPos = bufferedBytes;
        while (tempPos < bytes.length) {
-          int n = input.read(bytes, tempPos, size - tempPos);
+          int n = read(input, bytes, tempPos, size - tempPos);
          if (n == -1) {
            throw InvalidProtocolBufferException.truncatedMessage();
          }
@ -3047,7 +3089,7 @@ public abstract class CodedInputStream {
        try {
          while (totalSkipped < size) {
            int toSkip = size - totalSkipped;
-            long skipped = input.skip(toSkip);
+            long skipped = skip(input, toSkip);
            if (skipped < 0 || skipped > toSkip) {
              throw new IllegalStateException(
                  input.getClass()
@ -3484,9 +3526,25 @@ public abstract class CodedInputStream {
          return ByteString.wrap(bytes);
        }
      } else if (size > 0 && size <= remaining()) {
-        byte[] temp = new byte[size];
-        readRawBytesTo(temp, 0, size);
-        return ByteString.wrap(temp);
+        if (immutable && enableAliasing) {
+          ArrayList<ByteString> byteStrings = new ArrayList<>();
+          int l = size;
+          while (l > 0) {
+            if (currentRemaining() == 0) {
+              getNextByteBuffer();
+            }
+            int bytesToCopy = Math.min(l, (int) currentRemaining());
+            int idx = (int) (currentByteBufferPos - currentAddress);
+            byteStrings.add(ByteString.wrap(slice(idx, idx + bytesToCopy)));
+            l -= bytesToCopy;
+            currentByteBufferPos += bytesToCopy;
+          }
+          return ByteString.copyFrom(byteStrings);
+        } else {
+          byte[] temp = new byte[size];
+          readRawBytesTo(temp, 0, size);
+          return ByteString.wrap(temp);
+        }
      }

      if (size == 0) {
--- a/java/core/src/main/java/com/google/protobuf/FieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/FieldSet.java
@ -282,7 +282,7 @@ final class FieldSet<T extends FieldSet.FieldDescriptorLite<T>> {

      // Wrap the contents in a new list so that the caller cannot change
      // the list's contents after setting it.
-      final List newList = new ArrayList();
+      final List newList = new ArrayList<>();
      newList.addAll((List) value);
      for (final Object element : newList) {
        verifyType(descriptor, element);
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
@ -1537,11 +1537,16 @@ public abstract class GeneratedMessageLite<
      Schema<T> schema = Protobuf.getInstance().schemaFor(result);
      schema.mergeFrom(result, CodedInputStreamReader.forCodedInput(input), extensionRegistry);
      schema.makeImmutable(result);
+    } catch (InvalidProtocolBufferException e) {
+      if (e.getThrownFromInputStream()) {
+        e = new InvalidProtocolBufferException(e);
+      }
+      throw e.setUnfinishedMessage(result);
    } catch (IOException e) {
      if (e.getCause() instanceof InvalidProtocolBufferException) {
        throw (InvalidProtocolBufferException) e.getCause();
      }
-      throw new InvalidProtocolBufferException(e.getMessage()).setUnfinishedMessage(result);
+      throw new InvalidProtocolBufferException(e).setUnfinishedMessage(result);
    } catch (RuntimeException e) {
      if (e.getCause() instanceof InvalidProtocolBufferException) {
        throw (InvalidProtocolBufferException) e.getCause();
@ -1565,11 +1570,16 @@ public abstract class GeneratedMessageLite<
      if (result.memoizedHashCode != 0) {
        throw new RuntimeException();
      }
+    } catch (InvalidProtocolBufferException e) {
+      if (e.getThrownFromInputStream()) {
+        e = new InvalidProtocolBufferException(e);
+      }
+      throw e.setUnfinishedMessage(result);
    } catch (IOException e) {
      if (e.getCause() instanceof InvalidProtocolBufferException) {
        throw (InvalidProtocolBufferException) e.getCause();
      }
-      throw new InvalidProtocolBufferException(e.getMessage()).setUnfinishedMessage(result);
+      throw new InvalidProtocolBufferException(e).setUnfinishedMessage(result);
    } catch (IndexOutOfBoundsException e) {
      throw InvalidProtocolBufferException.truncatedMessage().setUnfinishedMessage(result);
    }
@ -1727,8 +1737,13 @@ public abstract class GeneratedMessageLite<
        return null;
      }
      size = CodedInputStream.readRawVarint32(firstByte, input);
+    } catch (InvalidProtocolBufferException e) {
+      if (e.getThrownFromInputStream()) {
+        e = new InvalidProtocolBufferException(e);
+      }
+      throw e;
    } catch (IOException e) {
-      throw new InvalidProtocolBufferException(e.getMessage());
+      throw new InvalidProtocolBufferException(e);
    }
    InputStream limitedInput = new LimitedInputStream(input, size);
    CodedInputStream codedInput = CodedInputStream.newInstance(limitedInput);
--- a/java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
+++ b/java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
@ -41,6 +41,7 @@ import java.io.IOException;
 public class InvalidProtocolBufferException extends IOException {
  private static final long serialVersionUID = -1616151763072450476L;
  private MessageLite unfinishedMessage = null;
+  private boolean wasThrownFromInputStream;

  public InvalidProtocolBufferException(final String description) {
    super(description);
@ -72,6 +73,28 @@ public class InvalidProtocolBufferException extends IOException {
    return unfinishedMessage;
  }

+  /** Set by CodedInputStream */
+  void setThrownFromInputStream() {
+    /* This write can be racy if the same exception is stored and then thrown by multiple custom
+     * InputStreams on different threads. But since it only ever moves from false->true, there's no
+     * problem. A thread checking this condition after catching this exception from a delegate
+     * stream of CodedInputStream is guaranteed to always observe true, because a write on the same
+     * thread set the value when the exception left the delegate. A thread checking the same
+     * condition with an exception created by CodedInputStream is guaranteed to always see false,
+     * because the exception has not been exposed to any code that could publish it to other threads
+     * and cause a write.
+     */
+    wasThrownFromInputStream = true;
+  }
+
+  /**
+   * Allows code catching IOException from CodedInputStream to tell whether this instance was thrown
+   * by a delegate InputStream, rather than directly by a parse failure.
+   */
+  boolean getThrownFromInputStream() {
+    return wasThrownFromInputStream;
+  }
+
  /**
   * Unwraps the underlying {@link IOException} if this exception was caused by an I/O problem.
   * Otherwise, returns {@code this}.
--- a/java/core/src/main/java/com/google/protobuf/RopeByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/RopeByteString.java
@ -603,7 +603,12 @@ final class RopeByteString extends ByteString {

  @Override
  public CodedInputStream newCodedInput() {
-    return CodedInputStream.newInstance(new RopeInputStream());
+    // Passing along direct references to internal ByteBuffers can support more efficient parsing
+    // via aliasing in CodedInputStream for users who wish to use it.
+    //
+    // Otherwise we force data copies, both in copying as an input stream and in buffering in the
+    // CodedInputSteam.
+    return CodedInputStream.newInstance(asReadOnlyByteBufferList(), /* bufferIsImmutable= */ true);
  }

  @Override
--- a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
@ -346,7 +346,7 @@ final class UnsafeUtil {
    return MEMORY_ACCESSOR.supportsUnsafeByteBufferOperations();
  }

-  private static boolean determineAndroidSupportByAddressSize(Class<?> addressClass) {
+  static boolean determineAndroidSupportByAddressSize(Class<?> addressClass) {
    if (!Android.isOnAndroidDevice()) {
      return false;
    }
--- a/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
@ -283,7 +283,7 @@ public class AbstractMessageTest extends TestCase {
    Message.Builder abstractMessageBuilder =
        new AbstractMessageWrapper.Builder(TestRequiredForeign.newBuilder());
    // mergeFrom() should not throw initialization error.
-    abstractMessageBuilder.mergeFrom(bytes).buildPartial();
+    Message unused1 = abstractMessageBuilder.mergeFrom(bytes).buildPartial();
    try {
      abstractMessageBuilder.mergeFrom(bytes).build();
      fail();
@ -295,7 +295,7 @@ public class AbstractMessageTest extends TestCase {
    Message.Builder dynamicMessageBuilder =
        DynamicMessage.newBuilder(TestRequiredForeign.getDescriptor());
    // mergeFrom() should not throw initialization error.
-    dynamicMessageBuilder.mergeFrom(bytes).buildPartial();
+    Message unused2 = dynamicMessageBuilder.mergeFrom(bytes).buildPartial();
    try {
      dynamicMessageBuilder.mergeFrom(bytes).build();
      fail();
--- a/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
+++ b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
@ -1142,6 +1142,39 @@ public class CodedInputStreamTest extends TestCase {
    }
  }

+  public void testIterableByteBufferInputStreamReadBytesWithAlias() throws Exception {
+    ByteArrayOutputStream byteArrayStream = new ByteArrayOutputStream();
+    CodedOutputStream output = CodedOutputStream.newInstance(byteArrayStream);
+    // A bytes field large enough that won't fit into the default block buffer.
+    // 4.5 is to test the case where the total size of input is not aligned with DEFAULT_BLOCK_SIZE.
+    final int bytesLength = DEFAULT_BLOCK_SIZE * 4 + (DEFAULT_BLOCK_SIZE / 2);
+    byte[] bytes = new byte[bytesLength];
+    for (int i = 0; i < bytesLength; i++) {
+      bytes[i] = (byte) (i % 256);
+    }
+    output.writeByteArrayNoTag(bytes);
+    output.flush();
+
+    // Input data is split into multiple ByteBuffers so that a single bytes spans across them.
+    // CodedInputStream with aliasing will decode it as a consequent rope by wrapping ByteBuffers.
+    byte[] data = byteArrayStream.toByteArray();
+    ArrayList<ByteBuffer> input = new ArrayList<>();
+    for (int i = 0; i < data.length; i += DEFAULT_BLOCK_SIZE) {
+      int rl = Math.min(DEFAULT_BLOCK_SIZE, data.length - i);
+      ByteBuffer rb = ByteBuffer.allocateDirect(rl);
+      rb.put(data, i, rl);
+      rb.flip();
+      input.add(rb);
+    }
+    final CodedInputStream inputStream = CodedInputStream.newInstance(input, true);
+    inputStream.enableAliasing(true);
+
+    ByteString result = inputStream.readBytes();
+    for (int i = 0; i < bytesLength; i++) {
+      assertEquals((byte) (i % 256), result.byteAt(i));
+    }
+  }
+
  public void testCompatibleTypes() throws Exception {
    long data = 0x100000000L;
    Int64Message message = Int64Message.newBuilder().setData(data).build();
@ -1196,7 +1229,7 @@ public class CodedInputStreamTest extends TestCase {
      // Expected
    }
  }
-  
+
  public void testMaliciousInputStream() throws Exception {
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
    CodedOutputStream codedOutputStream = CodedOutputStream.newInstance(outputStream);
@ -1210,17 +1243,17 @@ public class CodedInputStreamTest extends TestCase {
        return super.read(b, off, len);
      }
    };
-    
+
    // test ByteString
-    
+
    CodedInputStream codedInputStream = CodedInputStream.newInstance(inputStream, 1);
    ByteString byteString = codedInputStream.readBytes();
    assertEquals(0x0, byteString.byteAt(0));
    maliciousCapture.get(1)[0] = 0x9;
    assertEquals(0x0, byteString.byteAt(0));
-    
+
    // test ByteBuffer
-    
+
    inputStream.reset();
    maliciousCapture.clear();
    codedInputStream = CodedInputStream.newInstance(inputStream, 1);
@ -1228,10 +1261,10 @@ public class CodedInputStreamTest extends TestCase {
    assertEquals(0x0, byteBuffer.get(0));
    maliciousCapture.get(1)[0] = 0x9;
    assertEquals(0x0, byteBuffer.get(0));
-    
+

    // test byte[]
-    
+
    inputStream.reset();
    maliciousCapture.clear();
    codedInputStream = CodedInputStream.newInstance(inputStream, 1);
@ -1241,7 +1274,7 @@ public class CodedInputStreamTest extends TestCase {
    assertEquals(0x9, byteArray[0]); // MODIFICATION! Should we fix?

    // test rawBytes
-    
+
    inputStream.reset();
    maliciousCapture.clear();
    codedInputStream = CodedInputStream.newInstance(inputStream, 1);
@ -1251,4 +1284,33 @@ public class CodedInputStreamTest extends TestCase {
    maliciousCapture.get(1)[0] = 0x9;
    assertEquals(0x9, byteArray[0]); // MODIFICATION! Should we fix?
  }
+
+  public void testInvalidInputYieldsInvalidProtocolBufferException_readTag() throws Exception {
+    byte[] input = new byte[] {0x0a, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, 0x77};
+    CodedInputStream inputStream = CodedInputStream.newInstance(input);
+    try {
+      inputStream.readTag();
+      int size = inputStream.readRawVarint32();
+      inputStream.pushLimit(size);
+      inputStream.readTag();
+      fail();
+    } catch (InvalidProtocolBufferException ex) {
+      // Expected.
+    }
+  }
+
+  public void testInvalidInputYieldsInvalidProtocolBufferException_readBytes() throws Exception {
+    byte[] input =
+        new byte[] {0x0a, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, 0x67, 0x1a, 0x1a};
+    CodedInputStream inputStream = CodedInputStream.newInstance(input);
+    try {
+      inputStream.readTag();
+      int size = inputStream.readRawVarint32();
+      inputStream.pushLimit(size);
+      inputStream.readBytes();
+      fail();
+    } catch (InvalidProtocolBufferException ex) {
+      // Expected.
+    }
+  }
 }
--- a/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
@ -69,7 +69,7 @@ public class DynamicMessageTest extends TestCase {
    Message.Builder builder = DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
    Message firstMessage = builder.build();
    // double build()
-    builder.build();
+    Message unused = builder.build();
    // clear() after build()
    builder.clear();
    // setters after build()
--- a/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
@ -76,6 +76,7 @@ import junit.framework.TestCase;
 *
 * @author kenton@google.com Kenton Varda
 */
+@SuppressWarnings({"ProtoBuilderReturnValueIgnored", "ReturnValueIgnored"})
 public class GeneratedMessageTest extends TestCase {
  TestUtil.ReflectionTester reflectionTester =
      new TestUtil.ReflectionTester(TestAllTypes.getDescriptor(), null);
--- a/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
@ -1163,8 +1163,8 @@ public class MapForProto2Test extends TestCase {
  }

  public void testReservedWordsFieldNames() {
-    ReservedAsMapField.newBuilder().build();
-    ReservedAsMapFieldWithEnumValue.newBuilder().build();
+    ReservedAsMapField unused1 = ReservedAsMapField.newBuilder().build();
+    ReservedAsMapFieldWithEnumValue unused2 = ReservedAsMapFieldWithEnumValue.newBuilder().build();
  }

  public void testGetMap() {
--- a/java/core/src/test/java/com/google/protobuf/MapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapTest.java
@ -1294,8 +1294,8 @@ public class MapTest extends TestCase {
  }

  public void testReservedWordsFieldNames() {
-    ReservedAsMapField.newBuilder().build();
-    ReservedAsMapFieldWithEnumValue.newBuilder().build();
+    ReservedAsMapField unused1 = ReservedAsMapField.newBuilder().build();
+    ReservedAsMapFieldWithEnumValue unused2 = ReservedAsMapFieldWithEnumValue.newBuilder().build();
  }

  public void testDeterministicSerialziation() throws Exception {
--- a/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
+++ b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
@ -43,8 +43,10 @@ public class TestBadIdentifiers extends TestCase {

  public void testCompilation() {
    // If this compiles, it means the generation was correct.
-    TestBadIdentifiersProto.Deprecated.newBuilder();
-    TestBadIdentifiersProto.Override.newBuilder();
+    TestBadIdentifiersProto.Deprecated unused1 =
+        TestBadIdentifiersProto.Deprecated.newBuilder().build();
+    TestBadIdentifiersProto.Override unused2 =
+        TestBadIdentifiersProto.Override.getDefaultInstance();
  }

  public void testGetDescriptor() {
--- a/java/core/src/test/java/com/google/protobuf/TestBadIdentifiersLite.java
+++ b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiersLite.java
@ -45,8 +45,10 @@ public final class TestBadIdentifiersLite extends TestCase {

  public void testCompilation() {
    // If this compiles, it means the generation was correct.
-    TestBadIdentifiersProto.Deprecated.newBuilder();
-    TestBadIdentifiersProto.Override.newBuilder();
+    TestBadIdentifiersProto.Deprecated.Builder builder1 =
+        TestBadIdentifiersProto.Deprecated.newBuilder();
+    TestBadIdentifiersProto.Override.Builder builder2 =
+        TestBadIdentifiersProto.Override.newBuilder();
  }

  public void testConflictingFieldNames() throws Exception {
--- a/java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto
@ -1,56 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Author: Darick Tong (darick@google.com)
-syntax = "proto2";
-
-package protobuf_unittest;
-
-message Proto1 {
-  option experimental_java_message_interface =
-      "com.google.protobuf.ExtraInterfaces.HasBoolValue";
-  option experimental_java_message_interface =
-      "com.google.protobuf.ExtraInterfaces.HasStringValue<Proto1>";
-  option experimental_java_builder_interface =
-      "com.google.protobuf.ExtraInterfaces.HasStringValueBuilder"
-      "<Proto1, Builder>";
-
-  optional string string_value = 1;
-  optional bool bool_value = 2;
-  optional bytes byte_value = 3;
-  optional int32 int_value = 4;
-}
-
-message Proto2 {
-  option experimental_java_message_interface =
-      "com.google.protobuf.ExtraInterfaces.HasBoolValue";
-
-  optional bool bool_value = 1;
-}
--- a/java/lite/generate-test-sources-build.xml
+++ b/java/lite/generate-test-sources-build.xml
@ -4,6 +4,7 @@
        <arg value="--java_out=lite:${generated.testsources.dir}"/>
        <arg value="--proto_path=${protobuf.source.dir}"/>
        <arg value="--proto_path=${protobuf.basedir}/java/core/${test.proto.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/descriptor.proto"/>
        <arg value="${protobuf.source.dir}/google/protobuf/unittest.proto"/>
        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import.proto"/>
        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_lite.proto"/>
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml
@ -173,6 +173,7 @@
                    <include>UnknownFieldSetLite.java</include>
                    <include>UnknownFieldSetLiteSchema.java</include>
                    <include>UnmodifiableLazyStringList.java</include>
+                    <include>UnsafeByteOperations.java</include>
                    <include>UnsafeUtil.java</include>
                    <include>Utf8.java</include>
                    <include>WireFormat.java</include>
--- a/java/lite/src/test/java/com/google/protobuf/LiteTest.java
+++ b/java/lite/src/test/java/com/google/protobuf/LiteTest.java
@ -38,6 +38,7 @@ import com.google.protobuf.UnittestImportLite.ImportEnumLite;
 import com.google.protobuf.UnittestImportPublicLite.PublicImportMessageLite;
 import com.google.protobuf.UnittestLite.ForeignEnumLite;
 import com.google.protobuf.UnittestLite.ForeignMessageLite;
+import com.google.protobuf.UnittestLite.RecursiveMessage;
 import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
 import com.google.protobuf.UnittestLite.TestAllTypesLite;
 import com.google.protobuf.UnittestLite.TestAllTypesLite.NestedEnum;
@ -61,6 +62,7 @@ import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestRecursiveOne
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.lang.reflect.Field;
 import java.nio.ByteBuffer;
@ -1638,6 +1640,160 @@ public class LiteTest extends TestCase {
    }
  }

+  public void testParseFromStream_IOExceptionNotLost() throws Exception {
+    final IOException readException = new IOException();
+    try {
+      TestAllTypesLite.parseFrom(
+          CodedInputStream.newInstance(
+              new InputStream() {
+                @Override
+                public int read() throws IOException {
+                  throw readException;
+                }
+              }));
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+      boolean found = false;
+      for (Throwable exception = expected; exception != null; exception = exception.getCause()) {
+        if (exception == readException) {
+          found = true;
+          break;
+        }
+      }
+      if (!found) {
+        throw new AssertionError("Lost cause of parsing error", expected);
+      }
+    }
+  }
+
+  public void testParseDelimitedFromStream_IOExceptionNotLost() throws Exception {
+    final IOException readException = new IOException();
+    try {
+      TestAllTypesLite.parseDelimitedFrom(
+          new InputStream() {
+            @Override
+            public int read() throws IOException {
+              throw readException;
+            }
+          });
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+      boolean found = false;
+      for (Throwable exception = expected; exception != null; exception = exception.getCause()) {
+        if (exception == readException) {
+          found = true;
+          break;
+        }
+      }
+      if (!found) {
+        throw new AssertionError("Lost cause of parsing error", expected);
+      }
+    }
+  }
+
+  public void testParseFromArray_manyNestedMessagesError() throws Exception {
+    RecursiveMessage.Builder recursiveMessage =
+        RecursiveMessage.newBuilder().setPayload(ByteString.copyFrom(new byte[1]));
+    for (int i = 0; i < 20; i++) {
+      recursiveMessage = RecursiveMessage.newBuilder().setRecurse(recursiveMessage.build());
+    }
+    byte[] result = recursiveMessage.build().toByteArray();
+    result[
+            result.length
+                - CodedOutputStream.computeTagSize(RecursiveMessage.PAYLOAD_FIELD_NUMBER)
+                - CodedOutputStream.computeLengthDelimitedFieldSize(1)] =
+        0; // Set invalid tag
+    try {
+      RecursiveMessage.parseFrom(result);
+      fail("Result was: " + Arrays.toString(result));
+    } catch (InvalidProtocolBufferException expected) {
+      boolean found = false;
+      int exceptionCount = 0;
+      for (Throwable exception = expected; exception != null; exception = exception.getCause()) {
+        if (exception instanceof InvalidProtocolBufferException) {
+          exceptionCount++;
+        }
+        for (StackTraceElement element : exception.getStackTrace()) {
+          if (InvalidProtocolBufferException.class.getName().equals(element.getClassName())
+              && "invalidTag".equals(element.getMethodName())) {
+            found = true;
+          } else if (Android.isOnAndroidDevice()
+              && "decodeUnknownField".equals(element.getMethodName())) {
+            // Android is missing the first element of the stack trace - b/181147885
+            found = true;
+          }
+        }
+      }
+      if (!found) {
+        throw new AssertionError("Lost cause of parsing error", expected);
+      }
+      if (exceptionCount > 1) {
+        throw new AssertionError(exceptionCount + " nested parsing exceptions", expected);
+      }
+    }
+  }
+
+  public void testParseFromStream_manyNestedMessagesError() throws Exception {
+    RecursiveMessage.Builder recursiveMessage =
+        RecursiveMessage.newBuilder().setPayload(ByteString.copyFrom(new byte[1]));
+    for (int i = 0; i < 20; i++) {
+      recursiveMessage = RecursiveMessage.newBuilder().setRecurse(recursiveMessage.build());
+    }
+    byte[] result = recursiveMessage.build().toByteArray();
+    result[
+            result.length
+                - CodedOutputStream.computeTagSize(RecursiveMessage.PAYLOAD_FIELD_NUMBER)
+                - CodedOutputStream.computeLengthDelimitedFieldSize(1)] =
+        0; // Set invalid tag
+    try {
+      RecursiveMessage.parseFrom(CodedInputStream.newInstance(new ByteArrayInputStream(result)));
+      fail("Result was: " + Arrays.toString(result));
+    } catch (InvalidProtocolBufferException expected) {
+      boolean found = false;
+      int exceptionCount = 0;
+      for (Throwable exception = expected; exception != null; exception = exception.getCause()) {
+        if (exception instanceof InvalidProtocolBufferException) {
+          exceptionCount++;
+        }
+        for (StackTraceElement element : exception.getStackTrace()) {
+          if (InvalidProtocolBufferException.class.getName().equals(element.getClassName())
+              && "invalidTag".equals(element.getMethodName())) {
+            found = true;
+          } else if (Android.isOnAndroidDevice() && "readTag".equals(element.getMethodName())) {
+            // Android is missing the first element of the stack trace - b/181147885
+            found = true;
+          }
+        }
+      }
+      if (!found) {
+        throw new AssertionError("Lost cause of parsing error", expected);
+      }
+      if (exceptionCount > 1) {
+        throw new AssertionError(exceptionCount + " nested parsing exceptions", expected);
+      }
+    }
+  }
+
+  public void testParseFromStream_sneakyNestedException() throws Exception {
+    final InvalidProtocolBufferException sketchy =
+        new InvalidProtocolBufferException("Created in a sketchy way!")
+            .setUnfinishedMessage(TestAllTypesLite.getDefaultInstance());
+    try {
+      RecursiveMessage.parseFrom(
+          CodedInputStream.newInstance(
+              new InputStream() {
+                @Override
+                public int read() throws IOException {
+                  throw sketchy;
+                }
+              }));
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+      assertNotSame(expected, sketchy);
+    }
+    assertEquals(sketchy.getUnfinishedMessage(), TestAllTypesLite.getDefaultInstance());
+  }
+
  public void testMergeFrom_sanity() throws Exception {
    TestAllTypesLite one = TestUtilLite.getAllLiteSetBuilder().build();
    byte[] bytes = one.toByteArray();
@ -2250,24 +2406,26 @@ public class LiteTest extends TestCase {
  }

  public void testAddAllIteratesOnce() {
-    TestAllTypesLite.newBuilder()
-        .addAllRepeatedBool(new OneTimeIterableList<>(false))
-        .addAllRepeatedInt32(new OneTimeIterableList<>(0))
-        .addAllRepeatedInt64(new OneTimeIterableList<>(0L))
-        .addAllRepeatedFloat(new OneTimeIterableList<>(0f))
-        .addAllRepeatedDouble(new OneTimeIterableList<>(0d))
-        .addAllRepeatedBytes(new OneTimeIterableList<>(ByteString.EMPTY))
-        .addAllRepeatedString(new OneTimeIterableList<>(""))
-        .addAllRepeatedNestedMessage(new OneTimeIterableList<>(NestedMessage.getDefaultInstance()))
-        .addAllRepeatedBool(new OneTimeIterable<>(false))
-        .addAllRepeatedInt32(new OneTimeIterable<>(0))
-        .addAllRepeatedInt64(new OneTimeIterable<>(0L))
-        .addAllRepeatedFloat(new OneTimeIterable<>(0f))
-        .addAllRepeatedDouble(new OneTimeIterable<>(0d))
-        .addAllRepeatedBytes(new OneTimeIterable<>(ByteString.EMPTY))
-        .addAllRepeatedString(new OneTimeIterable<>(""))
-        .addAllRepeatedNestedMessage(new OneTimeIterable<>(NestedMessage.getDefaultInstance()))
-        .build();
+    TestAllTypesLite unused =
+        TestAllTypesLite.newBuilder()
+            .addAllRepeatedBool(new OneTimeIterableList<>(false))
+            .addAllRepeatedInt32(new OneTimeIterableList<>(0))
+            .addAllRepeatedInt64(new OneTimeIterableList<>(0L))
+            .addAllRepeatedFloat(new OneTimeIterableList<>(0f))
+            .addAllRepeatedDouble(new OneTimeIterableList<>(0d))
+            .addAllRepeatedBytes(new OneTimeIterableList<>(ByteString.EMPTY))
+            .addAllRepeatedString(new OneTimeIterableList<>(""))
+            .addAllRepeatedNestedMessage(
+                new OneTimeIterableList<>(NestedMessage.getDefaultInstance()))
+            .addAllRepeatedBool(new OneTimeIterable<>(false))
+            .addAllRepeatedInt32(new OneTimeIterable<>(0))
+            .addAllRepeatedInt64(new OneTimeIterable<>(0L))
+            .addAllRepeatedFloat(new OneTimeIterable<>(0f))
+            .addAllRepeatedDouble(new OneTimeIterable<>(0d))
+            .addAllRepeatedBytes(new OneTimeIterable<>(ByteString.EMPTY))
+            .addAllRepeatedString(new OneTimeIterable<>(""))
+            .addAllRepeatedNestedMessage(new OneTimeIterable<>(NestedMessage.getDefaultInstance()))
+            .build();
  }

  public void testAddAllIteratesOnce_throwsOnNull() {
--- a/java/pom.xml
+++ b/java/pom.xml
@ -75,7 +75,7 @@
      <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
-        <version>4.13.1</version>
+        <version>4.13.2</version>
        <scope>test</scope>
      </dependency>
      <dependency>
@ -93,18 +93,18 @@
      <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
-        <version>30.0-android</version>
+        <version>30.1-android</version>
      </dependency>
      <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava-testlib</artifactId>
-        <version>30.0-android</version>
+        <version>30.1-android</version>
        <scope>test</scope>
      </dependency>
      <dependency>
        <groupId>com.google.truth</groupId>
        <artifactId>truth</artifactId>
-        <version>1.0.1</version>
+        <version>1.1.2</version>
        <scope>test</scope>
      </dependency>
    </dependencies>
--- a/java/util/src/main/java/com/google/protobuf/util/Durations.java
+++ b/java/util/src/main/java/com/google/protobuf/util/Durations.java
@ -149,6 +149,12 @@ public final class Durations {
    return (duration.getSeconds() == 0) ? duration.getNanos() < 0 : duration.getSeconds() < 0;
  }

+  /** Returns whether the given {@link Duration} is positive or not. */
+  public static boolean isPositive(Duration duration) {
+    checkValid(duration);
+    return !isNegative(duration) && !duration.equals(ZERO);
+  }
+
  /**
   * Ensures that the given {@link Duration} is not negative.
   *
@ -157,7 +163,6 @@ public final class Durations {
   */
  @CanIgnoreReturnValue
  public static Duration checkNotNegative(Duration duration) {
-    checkValid(duration);
    checkArgument(!isNegative(duration), "duration (%s) must not be negative", toString(duration));
    return duration;
  }
@ -170,11 +175,7 @@ public final class Durations {
   */
  @CanIgnoreReturnValue
  public static Duration checkPositive(Duration duration) {
-    checkValid(duration);
-    checkArgument(
-        !isNegative(duration) && !duration.equals(ZERO),
-        "duration (%s) must be positive",
-        toString(duration));
+    checkArgument(isPositive(duration), "duration (%s) must be positive", toString(duration));
    return duration;
  }

--- a/kokoro/linux/dockerfile/test/csharp/Dockerfile
+++ b/kokoro/linux/dockerfile/test/csharp/Dockerfile
@ -1,4 +1,4 @@
-FROM debian:stretch
+FROM debian:buster

 # Install dependencies.  We start with the basic ones require to build protoc
 # and the C++ build
@ -22,14 +22,18 @@ RUN apt-get update && apt-get install -y \
  wget \
  && apt-get clean

+# Update ca-certificates to fix known buster + .NET 5 issue
+# https://github.com/NuGet/Announcements/issues/49
+RUN apt-get update && apt-get install -y ca-certificates && apt-get clean
+
 # dotnet SDK prerequisites
-RUN apt-get update && apt-get install -y libunwind8 libicu57 && apt-get clean
+RUN apt-get update && apt-get install -y libunwind8 libicu63 && apt-get clean

 # Install dotnet SDK via install script
 RUN wget -q https://dot.net/v1/dotnet-install.sh && \
    chmod u+x dotnet-install.sh && \
    ./dotnet-install.sh --version 2.1.802 && \
-    ./dotnet-install.sh --version 3.1.301 && \
+    ./dotnet-install.sh --version 5.0.102 && \
    ln -s /root/.dotnet/dotnet /usr/local/bin

 RUN wget -q www.nuget.org/NuGet.exe -O /usr/local/bin/nuget.exe
--- a/kokoro/linux/python/build.sh
+++ b/kokoro/linux/python/build.sh
@ -1,17 +0,0 @@
-#!/bin/bash
-#
-# This is the top-level script we give to Kokoro as the entry point for
-# running the "pull request" project:
-#
-# This script selects a specific Dockerfile (for building a Docker image) and
-# a script to run inside that image.  Then we delegate to the general
-# build_and_run_docker.sh script.
-
-# Change to repo root
-cd $(dirname $0)/../../..
-
-export DOCKERFILE_DIR=kokoro/linux/64-bit
-export DOCKER_RUN_SCRIPT=kokoro/linux/pull_request_in_docker.sh
-export OUTPUT_DIR=testoutput
-export TEST_SET="python"
-./kokoro/linux/build_and_run_docker.sh
--- a/kokoro/linux/python/continuous.cfg
+++ b/kokoro/linux/python/continuous.cfg
@ -1,11 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/linux/python/build.sh"
-timeout_mins: 120
-
-action {
-  define_artifacts {
-    regex: "**/sponge_log.xml"
-  }
-}
--- a/kokoro/linux/python/presubmit.cfg
+++ b/kokoro/linux/python/presubmit.cfg
@ -1,11 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/linux/python/build.sh"
-timeout_mins: 120
-
-action {
-  define_artifacts {
-    regex: "**/sponge_log.xml"
-  }
-}
--- a/kokoro/release/protoc/linux/build.sh
+++ b/kokoro/release/protoc/linux/build.sh
@ -23,7 +23,7 @@ sudo apt install -y g++-powerpc64le-linux-gnu
 protoc-artifacts/build-protoc.sh linux ppcle_64 protoc

 sudo apt install -y g++-s390x-linux-gnu
-protoc-artifacts/build-protoc.sh linux s390x protoc
+protoc-artifacts/build-protoc.sh linux s390_64 protoc

 # Use docker image to build linux artifacts.
 DOCKER_IMAGE_NAME=protobuf/protoc_$(sha1sum protoc-artifacts/Dockerfile | cut -f1 -d " ")
--- a/kokoro/release/python/linux/build_artifacts.sh
+++ b/kokoro/release/python/linux/build_artifacts.sh
@ -49,9 +49,31 @@ build_artifact_version() {
  sudo rm -rf $REPO_DIR
 }

+build_crosscompiled_aarch64_artifact_version() {
+  # crosscompilation is only supported with the dockcross manylinux2014 image
+  DOCKER_IMAGE=dockcross/manylinux2014-aarch64
+  PLAT=aarch64
+
+  # TODO(jtatermusch): currently when crosscompiling, "auditwheel repair" will be disabled
+  # since auditwheel doesn't work for crosscomiled wheels.
+  build_artifact_version $@
+}
+
 build_artifact_version 2.7
 build_artifact_version 3.5
 build_artifact_version 3.6
 build_artifact_version 3.7
 build_artifact_version 3.8
 build_artifact_version 3.9
+
+build_crosscompiled_aarch64_artifact_version 3.7
+build_crosscompiled_aarch64_artifact_version 3.8
+build_crosscompiled_aarch64_artifact_version 3.9
+
+# Put the aarch64 manylinux wheels under the "unofficial" subdirectory.
+# Only wheels directly under the artifacts/ directory will be published
+# to PyPI as part of the protobuf release process.
+# TODO(jtattermusch): include aarch64 wheels in the release
+# once they are sufficiently tested.
+mkdir -p $ARTIFACT_DIR/unofficial
+mv $ARTIFACT_DIR/protobuf-*-manylinux*_aarch64.whl $ARTIFACT_DIR/unofficial
--- a/kokoro/release/python/linux/config.sh
+++ b/kokoro/release/python/linux/config.sh
@ -6,15 +6,38 @@ function pre_build {
    # Runs in the root directory of this repository.
    pushd protobuf

-    yum install -y devtoolset-2-libatomic-devel
+    if [ "$PLAT" == "aarch64" ]
+    then
+      local configure_host_flag="--host=aarch64"
+    else
+      yum install -y devtoolset-2-libatomic-devel
+    fi

-    # Build protoc
+    # Build protoc and libprotobuf
    ./autogen.sh
-    ./configure
-
-    CXXFLAGS="-fPIC -g -O2" ./configure
+    CXXFLAGS="-fPIC -g -O2" ./configure $configure_host_flag
    make -j8

+    if [ "$PLAT" == "aarch64" ]
+    then
+      # we are crosscompiling for aarch64 while running on x64
+      # the simplest way for build_py command to be able to generate
+      # the protos is by running the protoc process under
+      # an emulator. That way we don't have to build a x64 version
+      # of protoc. The qemu-arm emulator is already included
+      # in the dockcross docker image.
+      # Running protoc under an emulator is fast as protoc doesn't
+      # really do much.
+
+      # create a simple shell wrapper that runs crosscompiled protoc under qemu
+      echo '#!/bin/bash' >protoc_qemu_wrapper.sh
+      echo 'exec qemu-aarch64 "../src/protoc" "$@"' >>protoc_qemu_wrapper.sh
+      chmod ugo+x protoc_qemu_wrapper.sh
+
+      # PROTOC variable is by build_py step that runs under ./python directory
+      export PROTOC=../protoc_qemu_wrapper.sh
+    fi
+
    # Generate python dependencies.
    pushd python
    python setup.py build_py
@ -35,7 +58,20 @@ function bdist_wheel_cmd {
    # Modify build version
    pwd
    ls
-    python setup.py bdist_wheel --cpp_implementation --compile_static_extension
+
+    if [ "$PLAT" == "aarch64" ]
+    then
+      # when crosscompiling for aarch64, --plat-name needs to be set explicitly
+      # to end up with correctly named wheel file
+      # the value should be manylinuxABC_ARCH and dockcross docker image
+      # conveniently provides the value in the AUDITWHEEL_PLAT env
+      local plat_name_flag="--plat-name=$AUDITWHEEL_PLAT"
+
+      # override the value of EXT_SUFFIX to make sure the crosscompiled .so files in the wheel have the correct filename suffix
+      export PROTOCOL_BUFFERS_OVERRIDE_EXT_SUFFIX="$(python -c 'import sysconfig; print(sysconfig.get_config_var("EXT_SUFFIX").replace("-x86_64-linux-gnu.so", "-aarch64-linux-gnu.so"))')"
+    fi
+
+    python setup.py bdist_wheel --cpp_implementation --compile_static_extension $plat_name_flag
    cp dist/*.whl $abs_wheelhouse
 }

@ -48,3 +84,12 @@ function run_tests {
    python --version
    python -c "from google.protobuf.pyext import _message;"
 }
+
+if [ "$PLAT" == "aarch64" ]
+then
+  # when crosscompiling for aarch64, override the default multibuild's repair_wheelhouse logic
+  # since "auditwheel repair" doesn't work for crosscompiled wheels
+  function repair_wheelhouse {
+      echo "Skipping repair_wheelhouse since auditwheel requires build architecture to match wheel architecture."
+  }
+fi
--- a/objectivec/GPBExtensionRegistry.m
+++ b/objectivec/GPBExtensionRegistry.m
@ -34,18 +34,20 @@
 #import "GPBDescriptor.h"

@implementation GPBExtensionRegistry {
-  NSMutableDictionary *mutableClassMap_;
+  CFMutableDictionaryRef mutableClassMap_;
 }

 - (instancetype)init {
  if ((self = [super init])) {
-    mutableClassMap_ = [[NSMutableDictionary alloc] init];
+    // The keys are ObjC classes, so straight up ptr comparisons are fine.
+    mutableClassMap_ = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, NULL,
+                                             &kCFTypeDictionaryValueCallBacks);
  }
  return self;
 }

 - (void)dealloc {
-  [mutableClassMap_ release];
+  CFRelease(mutableClassMap_);
  [super dealloc];
 }

@ -68,14 +70,13 @@

  Class containingMessageClass = extension.containingMessageClass;
  CFMutableDictionaryRef extensionMap = (CFMutableDictionaryRef)
-      [mutableClassMap_ objectForKey:containingMessageClass];
+      CFDictionaryGetValue(mutableClassMap_, containingMessageClass);
  if (extensionMap == nil) {
    // Use a custom dictionary here because the keys are numbers and conversion
    // back and forth from NSNumber isn't worth the cost.
    extensionMap = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, NULL,
                                             &kCFTypeDictionaryValueCallBacks);
-    [mutableClassMap_ setObject:(id)extensionMap
-                         forKey:(id<NSCopying>)containingMessageClass];
+    CFDictionarySetValue(mutableClassMap_, containingMessageClass, extensionMap);
    CFRelease(extensionMap);
  }

@ -87,7 +88,7 @@
                                       fieldNumber:(NSInteger)fieldNumber {
  Class messageClass = descriptor.messageClass;
  CFMutableDictionaryRef extensionMap = (CFMutableDictionaryRef)
-      [mutableClassMap_ objectForKey:messageClass];
+      CFDictionaryGetValue(mutableClassMap_, messageClass);
  ssize_t key = fieldNumber;
  GPBExtensionDescriptor *result =
      (extensionMap
@ -101,28 +102,28 @@ static void CopyKeyValue(const void *key, const void *value, void *context) {
  CFDictionarySetValue(extensionMap, key, value);
 }

+static void CopySubDictionary(const void *key, const void *value, void *context) {
+  CFMutableDictionaryRef mutableClassMap = (CFMutableDictionaryRef)context;
+  Class containingMessageClass = key;
+  CFMutableDictionaryRef otherExtensionMap = (CFMutableDictionaryRef)value;
+
+  CFMutableDictionaryRef extensionMap = (CFMutableDictionaryRef)
+      CFDictionaryGetValue(mutableClassMap, containingMessageClass);
+  if (extensionMap == nil) {
+    extensionMap = CFDictionaryCreateMutableCopy(kCFAllocatorDefault, 0, otherExtensionMap);
+    CFDictionarySetValue(mutableClassMap, containingMessageClass, extensionMap);
+    CFRelease(extensionMap);
+  } else {
+    CFDictionaryApplyFunction(otherExtensionMap, CopyKeyValue, extensionMap);
+  }
+}
+
 - (void)addExtensions:(GPBExtensionRegistry *)registry {
  if (registry == nil) {
    // In the case where there are no extensions just ignore.
    return;
  }
-  NSMutableDictionary *otherClassMap = registry->mutableClassMap_;
-  [otherClassMap enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL * stop) {
-#pragma unused(stop)
-    Class containingMessageClass = key;
-    CFMutableDictionaryRef otherExtensionMap = (CFMutableDictionaryRef)value;
-
-    CFMutableDictionaryRef extensionMap = (CFMutableDictionaryRef)
-        [mutableClassMap_ objectForKey:containingMessageClass];
-    if (extensionMap == nil) {
-      extensionMap = CFDictionaryCreateMutableCopy(kCFAllocatorDefault, 0, otherExtensionMap);
-      [mutableClassMap_ setObject:(id)extensionMap
-                           forKey:(id<NSCopying>)containingMessageClass];
-      CFRelease(extensionMap);
-    } else {
-      CFDictionaryApplyFunction(otherExtensionMap, CopyKeyValue, extensionMap);
-    }
-  }];
+  CFDictionaryApplyFunction(registry->mutableClassMap_, CopySubDictionary, mutableClassMap_);
 }

 #pragma clang diagnostic pop
--- a/php/README.md
+++ b/php/README.md
@ -16,8 +16,8 @@ generation functionality.

 To use PHP runtime library requires:

- C extension: PHP 5.5, 5.6, or 7.
- [PHP package](http://php.net/downloads.php): PHP 5.5, 5.6 or 7.
+- C extension: PHP 7.x, 8.0
+- [PHP package](http://php.net/downloads.php): PHP 5.5, 5.6, 7.x, or 8.0.

 ## Installation

--- a/php/src/Google/Protobuf/Internal/FileOptions.php
+++ b/php/src/Google/Protobuf/Internal/FileOptions.php
@ -25,20 +25,20 @@ class FileOptions extends \Google\Protobuf\Internal\Message
     */
    protected $java_package = null;
    /**
-     * If set, all the classes from the .proto file are wrapped in a single
-     * outer class with the given name.  This applies to both Proto1
-     * (equivalent to the old "--one_java_file" option) and Proto2 (where
-     * a .proto always translates to a single class, but you may want to
-     * explicitly choose the class name).
+     * Controls the name of the wrapper Java class generated for the .proto file.
+     * That class will always contain the .proto file's getDescriptor() method as
+     * well as any top-level extensions defined in the .proto file.
+     * If java_multiple_files is disabled, then all the other classes from the
+     * .proto file will be nested inside the single wrapper outer class.
     *
     * Generated from protobuf field <code>optional string java_outer_classname = 8;</code>
     */
    protected $java_outer_classname = null;
    /**
-     * If set true, then the Java code generator will generate a separate .java
+     * If enabled, then the Java code generator will generate a separate .java
     * file for each top-level message, enum, and service defined in the .proto
-     * file.  Thus, these types will *not* be nested inside the outer class
-     * named by java_outer_classname.  However, the outer class will still be
+     * file.  Thus, these types will *not* be nested inside the wrapper class
+     * named by java_outer_classname.  However, the wrapper class will still be
     * generated to contain the file's getDescriptor() method as well as any
     * top-level extensions defined in the file.
     *
@ -192,16 +192,16 @@ class FileOptions extends \Google\Protobuf\Internal\Message
     *           inappropriate because proto packages do not normally start with backwards
     *           domain names.
     *     @type string $java_outer_classname
-     *           If set, all the classes from the .proto file are wrapped in a single
-     *           outer class with the given name.  This applies to both Proto1
-     *           (equivalent to the old "--one_java_file" option) and Proto2 (where
-     *           a .proto always translates to a single class, but you may want to
-     *           explicitly choose the class name).
+     *           Controls the name of the wrapper Java class generated for the .proto file.
+     *           That class will always contain the .proto file's getDescriptor() method as
+     *           well as any top-level extensions defined in the .proto file.
+     *           If java_multiple_files is disabled, then all the other classes from the
+     *           .proto file will be nested inside the single wrapper outer class.
     *     @type bool $java_multiple_files
-     *           If set true, then the Java code generator will generate a separate .java
+     *           If enabled, then the Java code generator will generate a separate .java
     *           file for each top-level message, enum, and service defined in the .proto
-     *           file.  Thus, these types will *not* be nested inside the outer class
-     *           named by java_outer_classname.  However, the outer class will still be
+     *           file.  Thus, these types will *not* be nested inside the wrapper class
+     *           named by java_outer_classname.  However, the wrapper class will still be
     *           generated to contain the file's getDescriptor() method as well as any
     *           top-level extensions defined in the file.
     *     @type bool $java_generate_equals_and_hash
@ -319,11 +319,11 @@ class FileOptions extends \Google\Protobuf\Internal\Message
    }

    /**
-     * If set, all the classes from the .proto file are wrapped in a single
-     * outer class with the given name.  This applies to both Proto1
-     * (equivalent to the old "--one_java_file" option) and Proto2 (where
-     * a .proto always translates to a single class, but you may want to
-     * explicitly choose the class name).
+     * Controls the name of the wrapper Java class generated for the .proto file.
+     * That class will always contain the .proto file's getDescriptor() method as
+     * well as any top-level extensions defined in the .proto file.
+     * If java_multiple_files is disabled, then all the other classes from the
+     * .proto file will be nested inside the single wrapper outer class.
     *
     * Generated from protobuf field <code>optional string java_outer_classname = 8;</code>
     * @return string
@ -344,11 +344,11 @@ class FileOptions extends \Google\Protobuf\Internal\Message
    }

    /**
-     * If set, all the classes from the .proto file are wrapped in a single
-     * outer class with the given name.  This applies to both Proto1
-     * (equivalent to the old "--one_java_file" option) and Proto2 (where
-     * a .proto always translates to a single class, but you may want to
-     * explicitly choose the class name).
+     * Controls the name of the wrapper Java class generated for the .proto file.
+     * That class will always contain the .proto file's getDescriptor() method as
+     * well as any top-level extensions defined in the .proto file.
+     * If java_multiple_files is disabled, then all the other classes from the
+     * .proto file will be nested inside the single wrapper outer class.
     *
     * Generated from protobuf field <code>optional string java_outer_classname = 8;</code>
     * @param string $var
@ -363,10 +363,10 @@ class FileOptions extends \Google\Protobuf\Internal\Message
    }

    /**
-     * If set true, then the Java code generator will generate a separate .java
+     * If enabled, then the Java code generator will generate a separate .java
     * file for each top-level message, enum, and service defined in the .proto
-     * file.  Thus, these types will *not* be nested inside the outer class
-     * named by java_outer_classname.  However, the outer class will still be
+     * file.  Thus, these types will *not* be nested inside the wrapper class
+     * named by java_outer_classname.  However, the wrapper class will still be
     * generated to contain the file's getDescriptor() method as well as any
     * top-level extensions defined in the file.
     *
@ -389,10 +389,10 @@ class FileOptions extends \Google\Protobuf\Internal\Message
    }

    /**
-     * If set true, then the Java code generator will generate a separate .java
+     * If enabled, then the Java code generator will generate a separate .java
     * file for each top-level message, enum, and service defined in the .proto
-     * file.  Thus, these types will *not* be nested inside the outer class
-     * named by java_outer_classname.  However, the outer class will still be
+     * file.  Thus, these types will *not* be nested inside the wrapper class
+     * named by java_outer_classname.  However, the wrapper class will still be
     * generated to contain the file's getDescriptor() method as well as any
     * top-level extensions defined in the file.
     *
--- a/php/src/Google/Protobuf/Internal/RepeatedField.php
+++ b/php/src/Google/Protobuf/Internal/RepeatedField.php
@ -67,7 +67,7 @@ class RepeatedField implements \ArrayAccess, \IteratorAggregate, \Countable
    /**
     * Constructs an instance of RepeatedField.
     *
-     * @param long $type Type of the stored element.
+     * @param integer $type Type of the stored element.
     * @param string $klass Message/Enum class name (message/enum fields only).
     * @ignore
     */
@ -116,7 +116,7 @@ class RepeatedField implements \ArrayAccess, \IteratorAggregate, \Countable
     *
     * This will also be called for: $ele = $arr[0]
     *
-     * @param long $offset The index of the element to be fetched.
+     * @param integer $offset The index of the element to be fetched.
     * @return object The stored element at given index.
     * @throws \ErrorException Invalid type for index.
     * @throws \ErrorException Non-existing index.
@ -131,7 +131,7 @@ class RepeatedField implements \ArrayAccess, \IteratorAggregate, \Countable
     *
     * This will also be called for: $arr []= $ele and $arr[0] = ele
     *
-     * @param long $offset The index of the element to be assigned.
+     * @param integer $offset The index of the element to be assigned.
     * @param object $value The element to be assigned.
     * @return void
     * @throws \ErrorException Invalid type for index.
@ -204,7 +204,7 @@ class RepeatedField implements \ArrayAccess, \IteratorAggregate, \Countable
     *
     * This will also be called for: unset($arr)
     *
-     * @param long $offset The index of the element to be removed.
+     * @param integer $offset The index of the element to be removed.
     * @return void
     * @throws \ErrorException Invalid type for index.
     * @throws \ErrorException The element to be removed is not at the end of the
@ -227,7 +227,7 @@ class RepeatedField implements \ArrayAccess, \IteratorAggregate, \Countable
     *
     * This will also be called for: isset($arr)
     *
-     * @param long $offset The index of the element to be removed.
+     * @param integer $offset The index of the element to be removed.
     * @return bool True if the element at the given offset exists.
     * @throws \ErrorException Invalid type for index.
     */
--- a/protoc-artifacts/README.md
+++ b/protoc-artifacts/README.md
@ -20,7 +20,7 @@ the following files:
 ## Maven Location
 The published protoc artifacts are available on Maven here:

-    http://central.maven.org/maven2/com/google/protobuf/protoc/
+    https://repo.maven.apache.org/maven2/com/google/protobuf/protoc/

 ## Versioning
 The version of the ``protoc`` artifact must be the same as the version of the
@ -123,7 +123,7 @@ target directory layout:
          protoc.exe
        + ppcle_64
          protoc.exe
-        + s390x
+        + s390_64
          protoc.exe
      + osx
        + x86_64
--- a/protoc-artifacts/build-protoc.sh
+++ b/protoc-artifacts/build-protoc.sh
@ -93,7 +93,7 @@ checkArch ()
        assertEq $format "elf64-x86-64" $LINENO
      elif [[ "$ARCH" == aarch_64 ]]; then
        assertEq $format "elf64-little" $LINENO
-      elif [[ "$ARCH" == s390x ]]; then
+      elif [[ "$ARCH" == s390_64 ]]; then
 	if [[ $host_machine == s390x ]];then
 	  assertEq $format "elf64-s390" $LINENO
 	else
@ -149,7 +149,7 @@ checkDependencies ()
      white_list="linux-gate\.so\.1\|libpthread\.so\.0\|libm\.so\.6\|libc\.so\.6\|ld-linux\.so\.2"
    elif [[ "$ARCH" == x86_64 ]]; then
      white_list="linux-vdso\.so\.1\|libpthread\.so\.0\|libm\.so\.6\|libc\.so\.6\|ld-linux-x86-64\.so\.2"
-    elif [[ "$ARCH" == s390x ]]; then
+    elif [[ "$ARCH" == s390_64 ]]; then
      if [[ $host_machine != s390x ]];then
        dump_cmd='objdump -p '"$1"' | grep NEEDED'
      fi
@ -226,7 +226,7 @@ elif [[ "$(uname)" == Linux* ]]; then
    elif [[ "$ARCH" == ppcle_64 ]]; then
      CXXFLAGS="$CXXFLAGS -m64"
      CONFIGURE_ARGS="$CONFIGURE_ARGS --host=powerpc64le-linux-gnu"
-    elif [[ "$ARCH" == s390x ]]; then
+    elif [[ "$ARCH" == s390_64 ]]; then
      CXXFLAGS="$CXXFLAGS -m64"
      CONFIGURE_ARGS="$CONFIGURE_ARGS --host=s390x-linux-gnu"
    else
--- a/protoc-artifacts/build-zip.sh
+++ b/protoc-artifacts/build-zip.sh
@ -21,7 +21,7 @@ included. Each invocation will create 8 zip packages:
  dist/<TARGET>-<VERSION_NUMBER>-linux-x86_64.zip
  dist/<TARGET>-<VERSION_NUMBER>-linux-aarch_64.zip
  dist/<TARGET>-<VERSION_NUMBER>-linux-ppcle_64.zip
-  dist/<TARGET>-<VERSION_NUMBER>-linux-s390x.zip
+  dist/<TARGET>-<VERSION_NUMBER>-linux-s390_64.zip
 EOF
  exit 1
 fi
@ -38,7 +38,7 @@ declare -a FILE_NAMES=( \
  linux-x86_64.zip linux-x86_64.exe \
  linux-aarch_64.zip linux-aarch_64.exe \
  linux-ppcle_64.zip linux-ppcle_64.exe \
-  linux-s390x.zip linux-s390x.exe \
+  linux-s390_64.zip linux-s390_64.exe \
 )

 # List of all well-known types to be included.
--- a/protoc-artifacts/pom.xml
+++ b/protoc-artifacts/pom.xml
@ -81,8 +81,8 @@
                  <type>exe</type>
 	  	</artifact>
                <artifact>
-                  <file>${basedir}/target/linux/s390x/protoc.exe</file>
-                  <classifier>linux-s390x</classifier>
+                  <file>${basedir}/target/linux/s390_64/protoc.exe</file>
+                  <classifier>linux-s390_64</classifier>
                  <type>exe</type>
                </artifact>
              </artifacts>
--- a/python/google/protobuf/internal/message_test.py
+++ b/python/google/protobuf/internal/message_test.py
@ -841,8 +841,7 @@ class MessageTest(unittest.TestCase):
    m1.MergeFromString(m2.SerializeToString())
    self.assertEqual(1, m1.optional_nested_message.bb)

-  @unittest.skipIf(six.PY2, 'memoryview objects are not supported on py2')
-  def testMergeFromStringUsingMemoryViewWorksInPy3(self, message_module):
+  def testMergeFromStringUsingMemoryView(self, message_module):
    m2 = message_module.TestAllTypes()
    m2.optional_string = 'scalar string'
    m2.repeated_string.append('repeated string')
@ -864,12 +863,6 @@ class MessageTest(unittest.TestCase):
    self.assertIsInstance(m1.optional_string, six.text_type)
    self.assertIsInstance(m1.repeated_string[0], six.text_type)

-  @unittest.skipIf(six.PY3, 'memoryview is supported by py3')
-  def testMergeFromStringUsingMemoryViewIsPy2Error(self, message_module):
-    memview = memoryview(b'')
-    with self.assertRaises(TypeError):
-      message_module.TestAllTypes.FromString(memview)
-
  def testMergeFromEmpty(self, message_module):
    m1 = message_module.TestAllTypes()
    # Cpp extension will lazily create a sub message which is immutable.
--- a/python/google/protobuf/internal/python_message.py
+++ b/python/google/protobuf/internal/python_message.py
@ -1133,12 +1133,6 @@ def _AddSerializePartialToStringMethod(message_descriptor, cls):
 def _AddMergeFromStringMethod(message_descriptor, cls):
  """Helper for _AddMessageMethods()."""
  def MergeFromString(self, serialized):
-    if isinstance(serialized, memoryview) and six.PY2:
-      raise TypeError(
-          'memoryview not supported in Python 2 with the pure Python proto '
-          'implementation: this is to maintain compatibility with the C++ '
-          'implementation')
-
    serialized = memoryview(serialized)
    length = len(serialized)
    try:
--- a/python/google/protobuf/internal/text_format_test.py
+++ b/python/google/protobuf/internal/text_format_test.py
@ -1176,6 +1176,54 @@ class OnlyWorksWithProto2RightNowTests(TextFormatBase):
        '  }\n'
        '}\n')

+  def testDuplicateMapKey(self):
+    message = map_unittest_pb2.TestMap()
+    text = (
+        'map_uint64_uint64 {\n'
+        '  key: 123\n'
+        '  value: 17179869184\n'
+        '}\n'
+        'map_string_string {\n'
+        '  key: "abc"\n'
+        '  value: "first"\n'
+        '}\n'
+        'map_int32_foreign_message {\n'
+        '  key: 111\n'
+        '  value {\n'
+        '    c: 5\n'
+        '  }\n'
+        '}\n'
+        'map_uint64_uint64 {\n'
+        '  key: 123\n'
+        '  value: 321\n'
+        '}\n'
+        'map_string_string {\n'
+        '  key: "abc"\n'
+        '  value: "second"\n'
+        '}\n'
+        'map_int32_foreign_message {\n'
+        '  key: 111\n'
+        '  value {\n'
+        '    d: 5\n'
+        '  }\n'
+        '}\n')
+    text_format.Parse(text, message)
+    self.CompareToGoldenText(
+        text_format.MessageToString(message), 'map_uint64_uint64 {\n'
+        '  key: 123\n'
+        '  value: 321\n'
+        '}\n'
+        'map_string_string {\n'
+        '  key: "abc"\n'
+        '  value: "second"\n'
+        '}\n'
+        'map_int32_foreign_message {\n'
+        '  key: 111\n'
+        '  value {\n'
+        '    d: 5\n'
+        '  }\n'
+        '}\n')
+
  # In cpp implementation, __str__ calls the cpp implementation of text format.
  def testPrintMapUsingCppImplementation(self):
    message = map_unittest_pb2.TestMap()
@ -2348,6 +2396,13 @@ class OptionalColonMessageToStringTest(unittest.TestCase):
                '}\n')
    self.assertEqual(expected, output)

+  def testPrintShortFormatRepeatedFields(self):
+    message = unittest_pb2.TestAllTypes()
+    message.repeated_int32.append(1)
+    output = text_format.MessageToString(
+        message, use_short_repeated_primitives=True, force_colon=True)
+    self.assertEqual('repeated_int32: [1]\n', output)
+

 if __name__ == '__main__':
  unittest.main()
--- a/python/google/protobuf/pyext/descriptor.cc
+++ b/python/google/protobuf/pyext/descriptor.cc
@ -30,15 +30,18 @@

 // Author: petar@google.com (Petar Petrov)

+#include <google/protobuf/pyext/descriptor.h>
+
 #include <Python.h>
 #include <frameobject.h>
+
+#include <cstdint>
 #include <string>
 #include <unordered_map>

 #include <google/protobuf/io/coded_stream.h>
 #include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/dynamic_message.h>
-#include <google/protobuf/pyext/descriptor.h>
 #include <google/protobuf/pyext/descriptor_containers.h>
 #include <google/protobuf/pyext/descriptor_pool.h>
 #include <google/protobuf/pyext/message.h>
@ -195,7 +198,7 @@ bool Reparse(
  std::string serialized;
  from.SerializeToString(&serialized);
  io::CodedInputStream input(
-      reinterpret_cast<const uint8*>(serialized.c_str()), serialized.size());
+      reinterpret_cast<const uint8_t*>(serialized.c_str()), serialized.size());
  input.SetExtensionRegistry(message_factory->pool->pool,
                             message_factory->message_factory);
  bool success = to->ParseFromCodedStream(&input);
@ -247,8 +250,9 @@ static PyObject* GetOrBuildOptions(const DescriptorClass *descriptor) {
                 message_type->full_name().c_str());
    return NULL;
  }
+  ScopedPyObjectPtr args(PyTuple_New(0));
  ScopedPyObjectPtr value(
-      PyEval_CallObject(message_class->AsPyObject(), NULL));
+      PyObject_Call(message_class->AsPyObject(), args.get(), NULL));
  Py_DECREF(message_class);
  if (value == NULL) {
    return NULL;
@ -804,22 +808,22 @@ static PyObject* GetDefaultValue(PyBaseDescriptor *self, void *closure) {

  switch (_GetDescriptor(self)->cpp_type()) {
    case FieldDescriptor::CPPTYPE_INT32: {
-      int32 value = _GetDescriptor(self)->default_value_int32();
+      int32_t value = _GetDescriptor(self)->default_value_int32();
      result = PyInt_FromLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_INT64: {
-      int64 value = _GetDescriptor(self)->default_value_int64();
+      int64_t value = _GetDescriptor(self)->default_value_int64();
      result = PyLong_FromLongLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_UINT32: {
-      uint32 value = _GetDescriptor(self)->default_value_uint32();
+      uint32_t value = _GetDescriptor(self)->default_value_uint32();
      result = PyInt_FromSize_t(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_UINT64: {
-      uint64 value = _GetDescriptor(self)->default_value_uint64();
+      uint64_t value = _GetDescriptor(self)->default_value_uint64();
      result = PyLong_FromUnsignedLongLong(value);
      break;
    }
--- a/python/google/protobuf/pyext/descriptor_database.cc
+++ b/python/google/protobuf/pyext/descriptor_database.cc
@ -33,6 +33,8 @@

 #include <google/protobuf/pyext/descriptor_database.h>

+#include <cstdint>
+
 #include <google/protobuf/stubs/logging.h>
 #include <google/protobuf/stubs/common.h>
 #include <google/protobuf/descriptor.pb.h>
@ -164,7 +166,7 @@ bool PyDescriptorDatabase::FindAllExtensionNumbers(
    return false;
  }
  Py_ssize_t size = PyList_Size(py_list.get());
-  int64 item_value;
+  int64_t item_value;
  for (Py_ssize_t i = 0 ; i < size; ++i) {
    ScopedPyObjectPtr item(PySequence_GetItem(py_list.get(), i));
    item_value = PyLong_AsLong(item.get());
--- a/python/google/protobuf/pyext/descriptor_pool.cc
+++ b/python/google/protobuf/pyext/descriptor_pool.cc
@ -176,9 +176,10 @@ static PyDescriptorPool* PyDescriptorPool_NewWithDatabase(
 // The public DescriptorPool constructor.
 static PyObject* New(PyTypeObject* type,
                     PyObject* args, PyObject* kwargs) {
-  static char* kwlist[] = {"descriptor_db", 0};
+  static const char* kwlist[] = {"descriptor_db", 0};
  PyObject* py_database = NULL;
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|O", kwlist, &py_database)) {
+  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|O",
+                                   const_cast<char**>(kwlist), &py_database)) {
    return NULL;
  }
  DescriptorDatabase* database = NULL;
--- a/python/google/protobuf/pyext/extension_dict.cc
+++ b/python/google/protobuf/pyext/extension_dict.cc
@ -32,14 +32,16 @@
 // Author: tibell@google.com (Johan Tibell)

 #include <google/protobuf/pyext/extension_dict.h>
+
+#include <cstdint>
 #include <memory>

 #include <google/protobuf/stubs/logging.h>
 #include <google/protobuf/stubs/common.h>
+#include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/descriptor.h>
 #include <google/protobuf/dynamic_message.h>
 #include <google/protobuf/message.h>
-#include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/pyext/descriptor.h>
 #include <google/protobuf/pyext/message.h>
 #include <google/protobuf/pyext/message_factory.h>
@ -263,7 +265,7 @@ PyObject* _FindExtensionByName(ExtensionDict* self, PyObject* arg) {
 }

 PyObject* _FindExtensionByNumber(ExtensionDict* self, PyObject* arg) {
-  int64 number = PyLong_AsLong(arg);
+  int64_t number = PyLong_AsLong(arg);
  if (number == -1 && PyErr_Occurred()) {
    return NULL;
  }
--- a/python/google/protobuf/pyext/map_container.cc
+++ b/python/google/protobuf/pyext/map_container.cc
@ -32,15 +32,16 @@

 #include <google/protobuf/pyext/map_container.h>

+#include <cstdint>
 #include <memory>

 #include <google/protobuf/stubs/logging.h>
 #include <google/protobuf/stubs/common.h>
-#include <google/protobuf/map_field.h>
 #include <google/protobuf/map.h>
+#include <google/protobuf/map_field.h>
 #include <google/protobuf/message.h>
-#include <google/protobuf/pyext/message_factory.h>
 #include <google/protobuf/pyext/message.h>
+#include <google/protobuf/pyext/message_factory.h>
 #include <google/protobuf/pyext/repeated_composite_container.h>
 #include <google/protobuf/pyext/scoped_pyobject_ptr.h>
 #include <google/protobuf/stubs/map_util.h>
@ -99,7 +100,7 @@ struct MapIterator {
  //
  // We store this so that if the map is modified during iteration we can throw
  // an error.
-  uint64 version;
+  uint64_t version;
 };

 Message* MapContainer::GetMutableMessage() {
@ -462,10 +463,11 @@ int MapReflectionFriend::ScalarMapSetItem(PyObject* _self, PyObject* key,

 static PyObject* ScalarMapGet(PyObject* self, PyObject* args,
                              PyObject* kwargs) {
-  static char* kwlist[] = {"key", "default", nullptr};
+  static const char* kwlist[] = {"key", "default", nullptr};
  PyObject* key;
  PyObject* default_value = NULL;
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|O", kwlist, &key,
+  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|O",
+                                   const_cast<char**>(kwlist), &key,
                                   &default_value)) {
    return NULL;
  }
@ -757,10 +759,11 @@ PyObject* MapReflectionFriend::MessageMapToStr(PyObject* _self) {
 }

 PyObject* MessageMapGet(PyObject* self, PyObject* args, PyObject* kwargs) {
-  static char* kwlist[] = {"key", "default", nullptr};
+  static const char* kwlist[] = {"key", "default", nullptr};
  PyObject* key;
  PyObject* default_value = NULL;
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|O", kwlist, &key,
+  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|O",
+                                   const_cast<char**>(kwlist), &key,
                                   &default_value)) {
    return NULL;
  }
--- a/python/google/protobuf/pyext/map_container.h
+++ b/python/google/protobuf/pyext/map_container.h
@ -33,6 +33,7 @@

 #include <Python.h>

+#include <cstdint>
 #include <memory>

 #include <google/protobuf/descriptor.h>
@ -56,7 +57,7 @@ struct MapContainer : public ContainerBase {

  // We bump this whenever we perform a mutation, to invalidate existing
  // iterators.
-  uint64 version;
+  uint64_t version;
 };

 struct MessageMapContainer : public MapContainer {
--- a/python/google/protobuf/pyext/message.cc
+++ b/python/google/protobuf/pyext/message.cc
@ -35,6 +35,7 @@

 #include <structmember.h>  // A Python header file.

+#include <cstdint>
 #include <map>
 #include <memory>
 #include <string>
@ -196,15 +197,14 @@ static int AddDescriptors(PyObject* cls, const Descriptor* descriptor) {
 }

 static PyObject* New(PyTypeObject* type, PyObject* args, PyObject* kwargs) {
-  static char *kwlist[] = {"name", "bases", "dict", 0};
+  static const char* kwlist[] = {"name", "bases", "dict", 0};
  PyObject *bases, *dict;
  const char* name;

  // Check arguments: (name, bases, dict)
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "sO!O!:type", kwlist,
-                                   &name,
-                                   &PyTuple_Type, &bases,
-                                   &PyDict_Type, &dict)) {
+  if (!PyArg_ParseTupleAndKeywords(
+          args, kwargs, "sO!O!:type", const_cast<char**>(kwlist), &name,
+          &PyTuple_Type, &bases, &PyDict_Type, &dict)) {
    return NULL;
  }

@ -546,7 +546,7 @@ PyObject* PickleError_class;

 // Format an error message for unexpected types.
 // Always return with an exception set.
-void FormatTypeError(PyObject* arg, char* expected_types) {
+void FormatTypeError(PyObject* arg, const char* expected_types) {
  // This function is often called with an exception set.
  // Clear it to call PyObject_Repr() in good conditions.
  PyErr_Clear();
@ -1679,10 +1679,10 @@ static PyObject* InternalSerializeToString(
    CMessage* self, PyObject* args, PyObject* kwargs,
    bool require_initialized) {
  // Parse the "deterministic" kwarg; defaults to False.
-  static char* kwlist[] = { "deterministic", 0 };
+  static const char* kwlist[] = {"deterministic", 0};
  PyObject* deterministic_obj = Py_None;
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|O", kwlist,
-                                   &deterministic_obj)) {
+  if (!PyArg_ParseTupleAndKeywords(
+          args, kwargs, "|O", const_cast<char**>(kwlist), &deterministic_obj)) {
    return NULL;
  }
  // Preemptively convert to a bool first, so we don't need to back out of
@ -1927,9 +1927,8 @@ PyObject* SetAllowOversizeProtos(PyObject* m, PyObject* arg) {
 }

 static PyObject* MergeFromString(CMessage* self, PyObject* arg) {
-  const void* data;
-  Py_ssize_t data_length;
-  if (PyObject_AsReadBuffer(arg, &data, &data_length) < 0) {
+  Py_buffer data;
+  if (PyObject_GetBuffer(arg, &data, PyBUF_SIMPLE) < 0) {
    return NULL;
  }

@ -1942,7 +1941,8 @@ static PyObject* MergeFromString(CMessage* self, PyObject* arg) {
  const char* ptr;
  internal::ParseContext ctx(
      depth, false, &ptr,
-      StringPiece(static_cast<const char*>(data), data_length));
+      StringPiece(static_cast<const char*>(data.buf), data.len));
+  PyBuffer_Release(&data);
  ctx.data().pool = factory->pool->pool;
  ctx.data().factory = factory->message_factory;

@ -1968,9 +1968,9 @@ static PyObject* MergeFromString(CMessage* self, PyObject* arg) {
    // TODO(jieluo): Raise error and return NULL instead.
    // b/27494216
    PyErr_Warn(nullptr, "Unexpected end-group tag: Not all data was converted");
-    return PyInt_FromLong(data_length - ctx.BytesUntilLimit(ptr));
+    return PyInt_FromLong(data.len - ctx.BytesUntilLimit(ptr));
  }
-  return PyInt_FromLong(data_length);
+  return PyInt_FromLong(data.len);
 }

 static PyObject* ParseFromString(CMessage* self, PyObject* arg) {
@ -2191,22 +2191,22 @@ PyObject* InternalGetScalar(const Message* message,
  PyObject* result = NULL;
  switch (field_descriptor->cpp_type()) {
    case FieldDescriptor::CPPTYPE_INT32: {
-      int32 value = reflection->GetInt32(*message, field_descriptor);
+      int32_t value = reflection->GetInt32(*message, field_descriptor);
      result = PyInt_FromLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_INT64: {
-      int64 value = reflection->GetInt64(*message, field_descriptor);
+      int64_t value = reflection->GetInt64(*message, field_descriptor);
      result = PyLong_FromLongLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_UINT32: {
-      uint32 value = reflection->GetUInt32(*message, field_descriptor);
+      uint32_t value = reflection->GetUInt32(*message, field_descriptor);
      result = PyInt_FromSize_t(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_UINT64: {
-      uint64 value = reflection->GetUInt64(*message, field_descriptor);
+      uint64_t value = reflection->GetUInt64(*message, field_descriptor);
      result = PyLong_FromUnsignedLongLong(value);
      break;
    }
--- a/python/google/protobuf/pyext/message.h
+++ b/python/google/protobuf/pyext/message.h
@ -36,6 +36,7 @@

 #include <Python.h>

+#include <cstdint>
 #include <memory>
 #include <string>
 #include <unordered_map>
@ -286,25 +287,25 @@ PyObject* SetAllowOversizeProtos(PyObject* m, PyObject* arg);
  ((field_descriptor)->label() == FieldDescriptor::LABEL_REPEATED)

 #define GOOGLE_CHECK_GET_INT32(arg, value, err)  \
-  int32 value;                            \
+  int32_t value;                          \
  if (!CheckAndGetInteger(arg, &value)) { \
    return err;                           \
  }

 #define GOOGLE_CHECK_GET_INT64(arg, value, err)  \
-  int64 value;                            \
+  int64_t value;                          \
  if (!CheckAndGetInteger(arg, &value)) { \
    return err;                           \
  }

 #define GOOGLE_CHECK_GET_UINT32(arg, value, err) \
-  uint32 value;                           \
+  uint32_t value;                         \
  if (!CheckAndGetInteger(arg, &value)) { \
    return err;                           \
  }

 #define GOOGLE_CHECK_GET_UINT64(arg, value, err) \
-  uint64 value;                           \
+  uint64_t value;                         \
  if (!CheckAndGetInteger(arg, &value)) { \
    return err;                           \
  }
@ -329,7 +330,7 @@ PyObject* SetAllowOversizeProtos(PyObject* m, PyObject* arg);

 #define FULL_MODULE_NAME "google.protobuf.pyext._message"

-void FormatTypeError(PyObject* arg, char* expected_types);
+void FormatTypeError(PyObject* arg, const char* expected_types);
 template<class T>
 bool CheckAndGetInteger(PyObject* arg, T* value);
 bool CheckAndGetDouble(PyObject* arg, double* value);
--- a/python/google/protobuf/pyext/message_factory.cc
+++ b/python/google/protobuf/pyext/message_factory.cc
@ -77,9 +77,10 @@ PyMessageFactory* NewMessageFactory(PyTypeObject* type, PyDescriptorPool* pool)
 }

 PyObject* New(PyTypeObject* type, PyObject* args, PyObject* kwargs) {
-  static char* kwlist[] = {"pool", 0};
+  static const char* kwlist[] = {"pool", 0};
  PyObject* pool = NULL;
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|O", kwlist, &pool)) {
+  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|O",
+                                   const_cast<char**>(kwlist), &pool)) {
    return NULL;
  }
  ScopedPyObjectPtr owned_pool;
--- a/python/google/protobuf/pyext/repeated_scalar_container.cc
+++ b/python/google/protobuf/pyext/repeated_scalar_container.cc
@ -33,6 +33,7 @@

 #include <google/protobuf/pyext/repeated_scalar_container.h>

+#include <cstdint>
 #include <memory>

 #include <google/protobuf/stubs/common.h>
@ -207,25 +208,25 @@ static PyObject* Item(PyObject* pself, Py_ssize_t index) {
  PyObject* result = nullptr;
  switch (field_descriptor->cpp_type()) {
    case FieldDescriptor::CPPTYPE_INT32: {
-      int32 value =
+      int32_t value =
          reflection->GetRepeatedInt32(*message, field_descriptor, index);
      result = PyInt_FromLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_INT64: {
-      int64 value =
+      int64_t value =
          reflection->GetRepeatedInt64(*message, field_descriptor, index);
      result = PyLong_FromLongLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_UINT32: {
-      uint32 value =
+      uint32_t value =
          reflection->GetRepeatedUInt32(*message, field_descriptor, index);
      result = PyLong_FromLongLong(value);
      break;
    }
    case FieldDescriptor::CPPTYPE_UINT64: {
-      uint64 value =
+      uint64_t value =
          reflection->GetRepeatedUInt64(*message, field_descriptor, index);
      result = PyLong_FromUnsignedLongLong(value);
      break;
--- a/python/google/protobuf/text_format.py
+++ b/python/google/protobuf/text_format.py
@ -567,8 +567,6 @@ class _Printer(object):
      self.out.write(', ')
    self.PrintFieldValue(field, value[-1])
    self.out.write(']')
-    if self.force_colon:
-      self.out.write(':')
    self.out.write(' ' if self.as_one_line else '\n')

  def _PrintMessageFieldValue(self, value):
@ -1060,7 +1058,7 @@ class _Parser(object):
      value_cpptype = field.message_type.fields_by_name['value'].cpp_type
      if value_cpptype == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
        value = getattr(message, field.name)[sub_message.key]
-        value.MergeFrom(sub_message.value)
+        value.CopyFrom(sub_message.value)
      else:
        getattr(message, field.name)[sub_message.key] = sub_message.value

--- a/python/setup.py
+++ b/python/setup.py
@ -18,6 +18,7 @@ from setuptools import setup, Extension, find_packages

 from distutils.command.build_py import build_py as _build_py
 from distutils.command.clean import clean as _clean
+from distutils.command.build_ext import build_ext as _build_ext
 from distutils.spawn import find_executable

 # Find the Protocol Compiler.
@ -157,6 +158,22 @@ class build_py(_build_py):
            if not any(fnmatch.fnmatchcase(fil, pat=pat) for pat in exclude)]


+class build_ext(_build_ext):
+  def get_ext_filename(self, ext_name):
+      # since python3.5, python extensions' shared libraries use a suffix that corresponds to the value
+      # of sysconfig.get_config_var('EXT_SUFFIX') and contains info about the architecture the library targets.
+      # E.g. on x64 linux the suffix is ".cpython-XYZ-x86_64-linux-gnu.so"
+      # When crosscompiling python wheels, we need to be able to override this suffix
+      # so that the resulting file name matches the target architecture and we end up with a well-formed
+      # wheel.
+      filename = _build_ext.get_ext_filename(self, ext_name)
+      orig_ext_suffix = sysconfig.get_config_var("EXT_SUFFIX")
+      new_ext_suffix = os.getenv("PROTOCOL_BUFFERS_OVERRIDE_EXT_SUFFIX")
+      if new_ext_suffix and filename.endswith(orig_ext_suffix):
+        filename = filename[:-len(orig_ext_suffix)] + new_ext_suffix
+      return filename
+
+
 class test_conformance(_build_py):
  target = 'test_python'
  def run(self):
@ -279,8 +296,6 @@ if __name__ == '__main__':
        "Programming Language :: Python :: 3.5",
        "Programming Language :: Python :: 3.6",
        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: 3.8",
-        "Programming Language :: Python :: 3.9",
        ],
      namespace_packages=['google'],
      packages=find_packages(
@ -293,6 +308,7 @@ if __name__ == '__main__':
      cmdclass={
          'clean': clean,
          'build_py': build_py,
+          'build_ext': build_ext,
          'test_conformance': test_conformance,
      },
      install_requires=install_requires,
--- a/python/tox.ini
+++ b/python/tox.ini
@ -14,10 +14,9 @@ setenv =
 commands =
    python setup.py -q build_py
    python: python setup.py -q build
-    # --warnings_as_errors disabled until we update the Python C extension. See:
-    # https://github.com/protocolbuffers/protobuf/issues/7930
-    # cpp: python setup.py -q build --cpp_implementation --warnings_as_errors --compile_static_extension
-    cpp: python setup.py -q build --cpp_implementation --compile_static_extension
+    # --warnings_as_errors disabled for Python 2.7 because _POSIX_C_SOURCE and _XOPEN_SOURCE are redefined
+    py27-cpp: python setup.py -q build --cpp_implementation --compile_static_extension
+    py{33,34,35,36,37,38,39}-cpp: python setup.py -q build --cpp_implementation --warnings_as_errors --compile_static_extension
    python: python setup.py -q test -q
    cpp: python setup.py -q test -q --cpp_implementation
    python: python setup.py -q test_conformance
--- a/ruby/ext/google/protobuf_c/protobuf.c
+++ b/ruby/ext/google/protobuf_c/protobuf.c
@ -37,7 +37,7 @@
 #include "message.h"
 #include "repeated_field.h"

-VALUE cError;
+VALUE cParseError;
 VALUE cTypeError;

 const upb_fielddef* map_field_key(const upb_fielddef* field) {
@ -441,8 +441,10 @@ void Init_protobuf_c() {
  Map_register(protobuf);
  Message_register(protobuf);

-  cError = rb_const_get(protobuf, rb_intern("Error"));
+  cParseError = rb_const_get(protobuf, rb_intern("ParseError"));
+  rb_gc_register_mark_object(cParseError);
  cTypeError = rb_const_get(protobuf, rb_intern("TypeError"));
+  rb_gc_register_mark_object(cTypeError);

  rb_define_singleton_method(protobuf, "discard_unknown",
                             Google_Protobuf_discard_unknown, 1);
--- a/src/Makefile.am
+++ b/src/Makefile.am
@ -30,7 +30,7 @@ endif

 AM_CXXFLAGS = $(NO_OPT_CXXFLAGS) $(PROTOBUF_OPT_FLAG)

-AM_LDFLAGS = $(PTHREAD_CFLAGS)
+AM_LDFLAGS = $(PTHREAD_CFLAGS) ${LIBLOG_LIBS}

 # If I say "dist_include_DATA", automake complains that $(includedir) is not
 # a "legitimate" directory for DATA.  Screw you, automake.
--- a/src/google/protobuf/any.pb.cc
+++ b/src/google/protobuf/any.pb.cc
@ -68,10 +68,8 @@ const ::PROTOBUF_NAMESPACE_ID::internal::DescriptorTable descriptor_table_google
  schemas, file_default_instances, TableStruct_google_2fprotobuf_2fany_2eproto::offsets,
  file_level_metadata_google_2fprotobuf_2fany_2eproto, file_level_enum_descriptors_google_2fprotobuf_2fany_2eproto, file_level_service_descriptors_google_2fprotobuf_2fany_2eproto,
 };
-PROTOBUF_ATTRIBUTE_WEAK ::PROTOBUF_NAMESPACE_ID::Metadata
-descriptor_table_google_2fprotobuf_2fany_2eproto_metadata_getter(int index) {
-  ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(&descriptor_table_google_2fprotobuf_2fany_2eproto);
-  return descriptor_table_google_2fprotobuf_2fany_2eproto.file_level_metadata[index];
+PROTOBUF_ATTRIBUTE_WEAK const ::PROTOBUF_NAMESPACE_ID::internal::DescriptorTable* descriptor_table_google_2fprotobuf_2fany_2eproto_getter() {
+  return &descriptor_table_google_2fprotobuf_2fany_2eproto;
 }

 // Force running AddDescriptors() at dynamic initialization time.
@ -165,7 +163,6 @@ const char* Any::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::intern
  while (!ctx->Done(&ptr)) {
    ::PROTOBUF_NAMESPACE_ID::uint32 tag;
    ptr = ::PROTOBUF_NAMESPACE_ID::internal::ReadTag(ptr, &tag);
-    CHK_(ptr);
    switch (tag >> 3) {
      // string type_url = 1;
      case 1:
@ -186,7 +183,8 @@ const char* Any::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::intern
        continue;
      default: {
      handle_unusual:
-        if ((tag & 7) == 4 || tag == 0) {
+        if ((tag == 0) || ((tag & 7) == 4)) {
+          CHK_(ptr);
          ctx->SetLastTag(tag);
          goto success;
        }
@ -323,10 +321,11 @@ void Any::InternalSwap(Any* other) {
 }

 ::PROTOBUF_NAMESPACE_ID::Metadata Any::GetMetadata() const {
-  return GetMetadataStatic();
+  return ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(
+      &descriptor_table_google_2fprotobuf_2fany_2eproto_getter, &descriptor_table_google_2fprotobuf_2fany_2eproto_once,
+      file_level_metadata_google_2fprotobuf_2fany_2eproto[0]);
 }

-
 // @@protoc_insertion_point(namespace_scope)
 PROTOBUF_NAMESPACE_CLOSE
 PROTOBUF_NAMESPACE_OPEN
--- a/src/google/protobuf/any.pb.h
+++ b/src/google/protobuf/any.pb.h
@ -53,7 +53,6 @@ struct PROTOBUF_EXPORT TableStruct_google_2fprotobuf_2fany_2eproto {
  static const ::PROTOBUF_NAMESPACE_ID::uint32 offsets[];
 };
 extern PROTOBUF_EXPORT const ::PROTOBUF_NAMESPACE_ID::internal::DescriptorTable descriptor_table_google_2fprotobuf_2fany_2eproto;
-PROTOBUF_EXPORT ::PROTOBUF_NAMESPACE_ID::Metadata descriptor_table_google_2fprotobuf_2fany_2eproto_metadata_getter(int index);
 PROTOBUF_NAMESPACE_OPEN
 class Any;
 struct AnyDefaultTypeInternal;
@ -70,7 +69,7 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
    public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Any) */ {
 public:
  inline Any() : Any(nullptr) {}
-  virtual ~Any();
+  ~Any() override;
  explicit constexpr Any(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized);

  Any(const Any& from);
@ -96,10 +95,10 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
    return GetDescriptor();
  }
  static const ::PROTOBUF_NAMESPACE_ID::Descriptor* GetDescriptor() {
-    return GetMetadataStatic().descriptor;
+    return default_instance().GetMetadata().descriptor;
  }
  static const ::PROTOBUF_NAMESPACE_ID::Reflection* GetReflection() {
-    return GetMetadataStatic().reflection;
+    return default_instance().GetMetadata().reflection;
  }
  static const Any& default_instance() {
    return *internal_default_instance();
@ -200,12 +199,6 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
  public:

  ::PROTOBUF_NAMESPACE_ID::Metadata GetMetadata() const final;
-  private:
-  static ::PROTOBUF_NAMESPACE_ID::Metadata GetMetadataStatic() {
-    return ::descriptor_table_google_2fprotobuf_2fany_2eproto_metadata_getter(kIndexInFileMessages);
-  }
-
-  public:

  // nested types ----------------------------------------------------

@ -218,10 +211,8 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
  // string type_url = 1;
  void clear_type_url();
  const std::string& type_url() const;
-  void set_type_url(const std::string& value);
-  void set_type_url(std::string&& value);
-  void set_type_url(const char* value);
-  void set_type_url(const char* value, size_t size);
+  template <typename ArgT0 = const std::string&, typename... ArgT>
+  void set_type_url(ArgT0&& arg0, ArgT... args);
  std::string* mutable_type_url();
  std::string* release_type_url();
  void set_allocated_type_url(std::string* type_url);
@ -234,10 +225,8 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
  // bytes value = 2;
  void clear_value();
  const std::string& value() const;
-  void set_value(const std::string& value);
-  void set_value(std::string&& value);
-  void set_value(const char* value);
-  void set_value(const void* value, size_t size);
+  template <typename ArgT0 = const std::string&, typename... ArgT>
+  void set_value(ArgT0&& arg0, ArgT... args);
  std::string* mutable_value();
  std::string* release_value();
  void set_allocated_value(std::string* value);
@ -279,8 +268,11 @@ inline const std::string& Any::type_url() const {
  // @@protoc_insertion_point(field_get:google.protobuf.Any.type_url)
  return _internal_type_url();
 }
-inline void Any::set_type_url(const std::string& value) {
-  _internal_set_type_url(value);
+template <typename ArgT0, typename... ArgT>
+PROTOBUF_ALWAYS_INLINE
+inline void Any::set_type_url(ArgT0&& arg0, ArgT... args) {
+ 
+ type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
  // @@protoc_insertion_point(field_set:google.protobuf.Any.type_url)
 }
 inline std::string* Any::mutable_type_url() {
@ -294,25 +286,6 @@ inline void Any::_internal_set_type_url(const std::string& value) {
  
  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
 }
-inline void Any::set_type_url(std::string&& value) {
-  
-  type_url_.Set(
-    ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, ::std::move(value), GetArena());
-  // @@protoc_insertion_point(field_set_rvalue:google.protobuf.Any.type_url)
-}
-inline void Any::set_type_url(const char* value) {
-  GOOGLE_DCHECK(value != nullptr);
-  
-  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, ::std::string(value), GetArena());
-  // @@protoc_insertion_point(field_set_char:google.protobuf.Any.type_url)
-}
-inline void Any::set_type_url(const char* value,
-    size_t size) {
-  
-  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, ::std::string(
-      reinterpret_cast<const char*>(value), size), GetArena());
-  // @@protoc_insertion_point(field_set_pointer:google.protobuf.Any.type_url)
-}
 inline std::string* Any::_internal_mutable_type_url() {
  
  return type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
@ -340,8 +313,11 @@ inline const std::string& Any::value() const {
  // @@protoc_insertion_point(field_get:google.protobuf.Any.value)
  return _internal_value();
 }
-inline void Any::set_value(const std::string& value) {
-  _internal_set_value(value);
+template <typename ArgT0, typename... ArgT>
+PROTOBUF_ALWAYS_INLINE
+inline void Any::set_value(ArgT0&& arg0, ArgT... args) {
+ 
+ value_.SetBytes(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
  // @@protoc_insertion_point(field_set:google.protobuf.Any.value)
 }
 inline std::string* Any::mutable_value() {
@ -355,25 +331,6 @@ inline void Any::_internal_set_value(const std::string& value) {
  
  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
 }
-inline void Any::set_value(std::string&& value) {
-  
-  value_.Set(
-    ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, ::std::move(value), GetArena());
-  // @@protoc_insertion_point(field_set_rvalue:google.protobuf.Any.value)
-}
-inline void Any::set_value(const char* value) {
-  GOOGLE_DCHECK(value != nullptr);
-  
-  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, ::std::string(value), GetArena());
-  // @@protoc_insertion_point(field_set_char:google.protobuf.Any.value)
-}
-inline void Any::set_value(const void* value,
-    size_t size) {
-  
-  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, ::std::string(
-      reinterpret_cast<const char*>(value), size), GetArena());
-  // @@protoc_insertion_point(field_set_pointer:google.protobuf.Any.value)
-}
 inline std::string* Any::_internal_mutable_value() {
  
  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
--- a/src/google/protobuf/api.pb.cc
+++ b/src/google/protobuf/api.pb.cc
@ -150,10 +150,8 @@ const ::PROTOBUF_NAMESPACE_ID::internal::DescriptorTable descriptor_table_google
  schemas, file_default_instances, TableStruct_google_2fprotobuf_2fapi_2eproto::offsets,
  file_level_metadata_google_2fprotobuf_2fapi_2eproto, file_level_enum_descriptors_google_2fprotobuf_2fapi_2eproto, file_level_service_descriptors_google_2fprotobuf_2fapi_2eproto,
 };
-PROTOBUF_ATTRIBUTE_WEAK ::PROTOBUF_NAMESPACE_ID::Metadata
-descriptor_table_google_2fprotobuf_2fapi_2eproto_metadata_getter(int index) {
-  ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(&descriptor_table_google_2fprotobuf_2fapi_2eproto);
-  return descriptor_table_google_2fprotobuf_2fapi_2eproto.file_level_metadata[index];
+PROTOBUF_ATTRIBUTE_WEAK const ::PROTOBUF_NAMESPACE_ID::internal::DescriptorTable* descriptor_table_google_2fprotobuf_2fapi_2eproto_getter() {
+  return &descriptor_table_google_2fprotobuf_2fapi_2eproto;
 }

 // Force running AddDescriptors() at dynamic initialization time.
@ -270,7 +268,6 @@ const char* Api::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::intern
  while (!ctx->Done(&ptr)) {
    ::PROTOBUF_NAMESPACE_ID::uint32 tag;
    ptr = ::PROTOBUF_NAMESPACE_ID::internal::ReadTag(ptr, &tag);
-    CHK_(ptr);
    switch (tag >> 3) {
      // string name = 1;
      case 1:
@ -343,7 +340,8 @@ const char* Api::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::intern
        continue;
      default: {
      handle_unusual:
-        if ((tag & 7) == 4 || tag == 0) {
+        if ((tag == 0) || ((tag & 7) == 4)) {
+          CHK_(ptr);
          ctx->SetLastTag(tag);
          goto success;
        }
@ -575,10 +573,11 @@ void Api::InternalSwap(Api* other) {
 }

 ::PROTOBUF_NAMESPACE_ID::Metadata Api::GetMetadata() const {
-  return GetMetadataStatic();
+  return ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(
+      &descriptor_table_google_2fprotobuf_2fapi_2eproto_getter, &descriptor_table_google_2fprotobuf_2fapi_2eproto_once,
+      file_level_metadata_google_2fprotobuf_2fapi_2eproto[0]);
 }

-
 // ===================================================================

 class Method::_Internal {
@ -674,7 +673,6 @@ const char* Method::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::int
  while (!ctx->Done(&ptr)) {
    ::PROTOBUF_NAMESPACE_ID::uint32 tag;
    ptr = ::PROTOBUF_NAMESPACE_ID::internal::ReadTag(ptr, &tag);
-    CHK_(ptr);
    switch (tag >> 3) {
      // string name = 1;
      case 1:
@ -739,7 +737,8 @@ const char* Method::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::int
        continue;
      default: {
      handle_unusual:
-        if ((tag & 7) == 4 || tag == 0) {
+        if ((tag == 0) || ((tag & 7) == 4)) {
+          CHK_(ptr);
          ctx->SetLastTag(tag);
          goto success;
        }
@ -968,10 +967,11 @@ void Method::InternalSwap(Method* other) {
 }

 ::PROTOBUF_NAMESPACE_ID::Metadata Method::GetMetadata() const {
-  return GetMetadataStatic();
+  return ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(
+      &descriptor_table_google_2fprotobuf_2fapi_2eproto_getter, &descriptor_table_google_2fprotobuf_2fapi_2eproto_once,
+      file_level_metadata_google_2fprotobuf_2fapi_2eproto[1]);
 }

-
 // ===================================================================

 class Mixin::_Internal {
@ -1043,7 +1043,6 @@ const char* Mixin::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::inte
  while (!ctx->Done(&ptr)) {
    ::PROTOBUF_NAMESPACE_ID::uint32 tag;
    ptr = ::PROTOBUF_NAMESPACE_ID::internal::ReadTag(ptr, &tag);
-    CHK_(ptr);
    switch (tag >> 3) {
      // string name = 1;
      case 1:
@ -1065,7 +1064,8 @@ const char* Mixin::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::inte
        continue;
      default: {
      handle_unusual:
-        if ((tag & 7) == 4 || tag == 0) {
+        if ((tag == 0) || ((tag & 7) == 4)) {
+          CHK_(ptr);
          ctx->SetLastTag(tag);
          goto success;
        }
@ -1206,10 +1206,11 @@ void Mixin::InternalSwap(Mixin* other) {
 }

 ::PROTOBUF_NAMESPACE_ID::Metadata Mixin::GetMetadata() const {
-  return GetMetadataStatic();
+  return ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(
+      &descriptor_table_google_2fprotobuf_2fapi_2eproto_getter, &descriptor_table_google_2fprotobuf_2fapi_2eproto_once,
+      file_level_metadata_google_2fprotobuf_2fapi_2eproto[2]);
 }

-
 // @@protoc_insertion_point(namespace_scope)
 PROTOBUF_NAMESPACE_CLOSE
 PROTOBUF_NAMESPACE_OPEN
--- a/Show More
+++ b/Show More