internal changes

PiperOrigin-RevId: 503201591

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

@@ -1100,10 +1100,11 @@ void FileGenerator::GenerateReflectionInitializationCode(io::Printer* p) {
         }
       )cc");
 
-  // For descriptor.proto we want to avoid doing any dynamic initialization,
-  // because in some situations that would otherwise pull in a lot of
-  // unnecessary code that can't be stripped by --gc-sections. Descriptor
-  // initialization will still be performed lazily when it's needed.
+  // For proto files included in the full runtime (i.e. descriptor.proto
+  // and extension_declarations.proto), we want to avoid doing any dynamic
+  // initialization, because in some situations that would otherwise pull
+  // in a lot of unnecessary code that can't be stripped by --gc-sections.
+  // Initialization will still be performed lazily when it's needed.
   if (file_->name() == "net/proto2/proto/descriptor.proto") {
     return;
   }

src/google/protobuf/descriptor.cc

@@ -38,6 +38,7 @@
 #include <array>
 #include <cstdlib>
 #include <functional>
+#include <iterator>
 #include <limits>
 #include <memory>
 #include <sstream>
@@ -62,8 +63,11 @@
 #include "absl/strings/str_format.h"
 #include "absl/strings/str_join.h"
 #include "absl/strings/str_split.h"
+#include "absl/strings/string_view.h"
+#include "absl/strings/strip.h"
 #include "absl/strings/substitute.h"
 #include "absl/synchronization/mutex.h"
+#include "absl/types/optional.h"
 #include "google/protobuf/any.h"
 #include "google/protobuf/descriptor.pb.h"
 #include "google/protobuf/descriptor_database.h"
@@ -1872,6 +1876,7 @@ void DescriptorPool::AddUnusedImportTrackFile(absl::string_view file_name,
   unused_import_track_files_[file_name] = is_error;
 }
 
+
 void DescriptorPool::ClearUnusedImportTrackFiles() {
   unused_import_track_files_.clear();
 }
@@ -1912,7 +1917,11 @@ DescriptorPool* DescriptorPool::internal_generated_pool() {
 
 const DescriptorPool* DescriptorPool::generated_pool() {
   const DescriptorPool* pool = internal_generated_pool();
-  // Ensure that descriptor.proto has been registered in the generated pool.
+  // Ensure that descriptor.proto and extension_declarations.proto get
+  // registered in the generated pool. These protos are a special case
+  // because they are included in the full runtime. We have to avoid
+  // registering them pre-main, because we need to ensure that the linker
+  // --gc-sections step can strip out the full runtime if it is unused.
   DescriptorProto::descriptor();
   return pool;
 }
@@ -6465,6 +6474,7 @@ void DescriptorBuilder::CrossLinkExtensionRange(
   }
 }
 
+
 void DescriptorBuilder::CrossLinkField(FieldDescriptor* field,
                                        const FieldDescriptorProto& proto) {
   if (field->options_ == nullptr) {
@@ -7104,7 +7114,7 @@ void DescriptorBuilder::ValidateFieldOptions(
   // determine whether the json_name option is set on the field. Here we
   // compare it against the default calculated json_name value and consider
   // the option set if they are different. This won't catch the case when
-  // an user explicitly sets json_name to the default value, but should be
+  // a user explicitly sets json_name to the default value, but should be
   // good enough to catch common misuses.
   if (field->is_extension() &&
       (field->has_json_name() &&

src/google/protobuf/descriptor.h

@@ -70,6 +70,7 @@
 #include "google/protobuf/stubs/logging.h"
 #include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
+#include "absl/types/optional.h"
 #include "google/protobuf/port.h"
 
 // Must be included last.
@@ -83,6 +84,9 @@
 namespace google {
 namespace protobuf {
 
+// Defined in extension_declaration.proto.
+class ExtensionMetadata;
+
 // Defined in this file.
 class Descriptor;
 class FieldDescriptor;
@@ -140,6 +144,7 @@ class Formatter;
 
 namespace descriptor_unittest {
 class DescriptorTest;
+class ValidationErrorTest;
 }  // namespace descriptor_unittest
 
 // Defined in printer.h
@@ -2056,6 +2061,7 @@ class PROTOBUF_EXPORT DescriptorPool {
   friend class FileDescriptor;
   friend class DescriptorBuilder;
   friend class FileDescriptorTables;
+  friend class google::protobuf::descriptor_unittest::ValidationErrorTest;
 
   // Return true if the given name is a sub-symbol of any non-package
   // descriptor that already exists in the descriptor pool.  (The full
@@ -2131,6 +2137,7 @@ class PROTOBUF_EXPORT DescriptorPool {
   // Set of files to track for unused imports. The bool value when true means
   // unused imports are treated as errors (and as warnings when false).
   absl::flat_hash_map<std::string, bool> unused_import_track_files_;
+
 };
 
 

src/google/protobuf/descriptor_unittest.cc

@@ -45,6 +45,7 @@
 #include "absl/container/btree_set.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/strings/str_format.h"
+#include "absl/strings/string_view.h"
 #include "google/protobuf/unittest.pb.h"
 #include "google/protobuf/unittest_custom_options.pb.h"
 #include "google/protobuf/stubs/common.h"
@@ -3933,6 +3934,7 @@ class ValidationErrorTest : public testing::Test {
     return GOOGLE_CHECK_NOTNULL(pool_.BuildFile(file_proto));
   }
 
+
   // Parse file_text as a FileDescriptorProto in text format and add it
   // to the DescriptorPool.  Expect errors to be produced which match the
   // given error text.
@@ -7078,6 +7080,7 @@ TEST_F(ValidationErrorTest, UnusedImportWithOtherError) {
 }
 
 
+
 TEST_F(ValidationErrorTest, PackageTooLong) {
   BuildFileWithErrors(
       "name: \"foo.proto\" "

src/google/protobuf/port_def.inc

@@ -221,6 +221,10 @@ static_assert(PROTOBUF_CPLUSPLUS_MIN(201402L), "Protobuf only supports C++14 and
 // Owner: mkruskal@
 #define PROTOBUF_FUTURE_REMOVE_CLEARED_API 1
 
+// Used for descriptor proto extension declarations.
+// Owner: shaod@, gberg@
+#define PROTOBUF_FUTURE_DESCRIPTOR_EXTENSION_DECL 1
+
 #else
 #define PROTOBUF_FUTURE_FINAL
 #endif

src/google/protobuf/port_undef.inc

@@ -119,6 +119,7 @@
 #undef PROTOBUF_FUTURE_MAP_PAIR_UPGRADE
 #undef PROTOBUF_FUTURE_REMOVE_DEFAULT_FIELD_COMPARATOR
 #undef PROTOBUF_FUTURE_REMOVE_CLEARED_API
+#undef PROTOBUF_FUTURE_DESCRIPTOR_EXTENSION_DECL
 #endif
 
 #undef PROTOBUF_FUTURE_FINAL