Internal changes

editions/golden/compare_cpp_codegen_failure.xml

@@ -2,10 +2,10 @@
 <testsuites tests="1" name="AllTests">
 <testsuite name="EditionsCodegenTests">
 <testcase name="third_party/protobuf/editions/golden/simple_proto3.pb.cc" status="run" result="completed" classname="DiffTest">
-<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.cc&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#include &quot;third_party/protobuf/editions/golden/simple_proto3.pb.h&quot;&#x0A;&#x0A;#include &lt;algorithm&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_impl.h&quot;&#x0A;#include &quot;third_party/protobuf/internal_visibility.h&quot;&#x0A;#include &quot;third_party/protobuf/extension_set.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/wire_format_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/io/zero_copy_stream_impl_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/generated_message_table_impl.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;, with the difference:&#x0A;@@ @@&#x0A;     ::_pbi::TcParser::GetTable&lt;::protobuf_editions_test::golden::SimpleProto3&gt;(),  // to_prefetch&#x0A;     #endif  // PROTOBUF_PREFETCH_PARSE_TABLE&#x0A;   }, {{&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1;&#x0A;     {::_pbi::TcParser::FastV32S1,&#x0A;      {8, 0, 0,&#x0A;       PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_)}},&#x0A;   }}, {{&#x0A;     65535, 65535&#x0A;   }}, {{&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1;&#x0A;     {PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_), _Internal::kHasBitsOffset + 0, 0, (0 | ::_fl::kFcOptional | ::_fl::kInt32)},&#x0A;   }},&#x0A;   // no aux_entries&#x0A;@@ @@&#x0A;   (void)cached_has_bits;&#x0A; &#x0A;   cached_has_bits = this_._impl_._has_bits_[0];&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1;&#x0A;   if (CheckHasBit(cached_has_bits, 0x00000001U)) {&#x0A;     target =&#x0A;         ::proto2::internal::WireFormatLite::WriteInt32ToArrayWithField&lt;1&gt;(&#x0A;@@ @@&#x0A;   (void)cached_has_bits;&#x0A; &#x0A;    {&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1;&#x0A;     cached_has_bits = this_._impl_._has_bits_[0];&#x0A;     if (CheckHasBit(cached_has_bits, 0x00000001U)) {&#x0A;       total_size += ::_pbi::WireFormatLite::Int32SizePlusOne(" type=""></failure>
+<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.cc&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#include &quot;third_party/protobuf/editions/golden/simple_proto3.pb.h&quot;&#x0A;&#x0A;#include &lt;algorithm&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_impl.h&quot;&#x0A;#include &quot;third_party/protobuf/internal_visibility.h&quot;&#x0A;#include &quot;third_party/protobuf/extension_set.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/wire_format_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/io/zero_copy_stream_impl_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;, with the difference:&#x0A;@@ @@&#x0A;     ::_pbi::TcParser::GetTable&lt;::protobuf_editions_test::golden::SimpleProto3&gt;(),  // to_prefetch&#x0A;     #endif  // PROTOBUF_PREFETCH_PARSE_TABLE&#x0A;   }, {{&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1;&#x0A;     {::_pbi::TcParser::FastV32S1,&#x0A;      {8, 0, 0,&#x0A;       PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_)}},&#x0A;   }}, {{&#x0A;     65535, 65535&#x0A;   }}, {{&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1;&#x0A;     {PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_), _Internal::kHasBitsOffset + 0, 0, (0 | ::_fl::kFcOptional | ::_fl::kInt32)},&#x0A;   }},&#x0A;   // no aux_entries&#x0A;@@ @@&#x0A;   (void)cached_has_bits;&#x0A; &#x0A;   cached_has_bits = this_._impl_._has_bits_[0];&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1;&#x0A;   if (CheckHasBit(cached_has_bits, 0x00000001U)) {&#x0A;     target =&#x0A;         ::proto2::internal::WireFormatLite::WriteInt32ToArrayWithField&lt;1&gt;(&#x0A;@@ @@&#x0A;   (void)cached_has_bits;&#x0A; &#x0A;    {&#x0A;-    // optional int32 int32_field = 1;&#x0A;+    // int32 int32_field = 1;&#x0A;     cached_has_bits = this_._impl_._has_bits_[0];&#x0A;     if (CheckHasBit(cached_has_bits, 0x00000001U)) {&#x0A;       total_size += ::_pbi::WireFormatLite::Int32SizePlusOne(" type=""></failure>
 </testcase>
 <testcase name="third_party/protobuf/editions/golden/simple_proto3.pb.h" status="run" result="completed" classname="DiffTest">
-<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.h&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#ifndef third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;#define third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;&#x0A;#include &lt;limits&gt;&#x0A;#include &lt;string&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &lt;utility&gt;&#x0A;&#x0A;// clang-format off&#x0A;#include &quot;third_party/protobuf/runtime_version.h&quot;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/arena.h&quot;&#x0A;#include &quot;third_party/protobuf/arenastring.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_decl.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/generated_message_table.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/generated_message_table_impl.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/batch_builder.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/batch_wire_format.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/metadata_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/message_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;// clang-format on&#x0A;&#x0A;#endif  // third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;, with the difference:&#x0A;@@ @@&#x0A;   enum : int {&#x0A;     kInt32FieldFieldNumber = 1,&#x0A;   };&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1;&#x0A;   [[nodiscard]] bool has_int32_field()&#x0A;       const;&#x0A;   void clear_int32_field() ;&#x0A;@@ @@&#x0A; &#x0A; // SimpleProto3&#x0A; &#x0A;-// optional int32 int32_field = 1;&#x0A;+// int32 int32_field = 1;&#x0A; inline bool SimpleProto3::has_int32_field() const {&#x0A;   bool value = CheckHasBit(_impl_._has_bits_[0], 0x00000001U);&#x0A;   return value;" type=""></failure>
+<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.h&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler.  DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;&#x0A;#ifndef third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;#define third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;&#x0A;#include &lt;limits&gt;&#x0A;#include &lt;string&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &lt;utility&gt;&#x0A;&#x0A;// clang-format off&#x0A;#include &quot;third_party/protobuf/runtime_version.h&quot;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/arena.h&quot;&#x0A;#include &quot;third_party/protobuf/arenastring.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_decl.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/batch_builder.h&quot;&#x0A;#include &quot;third_party/protobuf/v2/batch_wire_format.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/metadata_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/message_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;// clang-format on&#x0A;&#x0A;#endif  // third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;, with the difference:&#x0A;@@ @@&#x0A;   enum : int {&#x0A;     kInt32FieldFieldNumber = 1,&#x0A;   };&#x0A;-  // optional int32 int32_field = 1;&#x0A;+  // int32 int32_field = 1;&#x0A;   [[nodiscard]] bool has_int32_field()&#x0A;       const;&#x0A;   void clear_int32_field() ;&#x0A;@@ @@&#x0A; &#x0A; // SimpleProto3&#x0A; &#x0A;-// optional int32 int32_field = 1;&#x0A;+// int32 int32_field = 1;&#x0A; inline bool SimpleProto3::has_int32_field() const {&#x0A;   bool value = CheckHasBit(_impl_._has_bits_[0], 0x00000001U);&#x0A;   return value;" type=""></failure>
 </testcase>
 <testcase name="third_party/protobuf/editions/golden/simple_proto3.proto.static_reflection.h" status="run" result="completed" classname="DiffTest">
 </testcase>

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

@@ -216,6 +216,7 @@ void SingularEnum::GenerateInlineAccessorDefinitions(io::Printer* p) const {
   }
 }
 
+
 class RepeatedEnum : public FieldGeneratorBase {
  public:
   RepeatedEnum(const FieldDescriptor* field, const Options& opts,
@@ -584,6 +585,7 @@ void RepeatedEnum::GenerateByteSize(io::Printer* p) const {
         total_size += data_size + tag_size;
       )cc");
 }
+
 }  // namespace
 
 std::unique_ptr<FieldGeneratorBase> MakeSinguarEnumGenerator(

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

@@ -423,6 +423,9 @@ class RepeatedPrimitive final : public FieldGeneratorBase {
   void GenerateByteSize(io::Printer* p) const override;
 
  private:
+  template <bool kUseCompactFieldNumbers>
+  void GenerateByteSizeV2Impl(io::Printer* p, bool try_batch) const;
+
   bool HasCachedSize() const {
     bool is_packed_varint =
         field_->is_packed() && !FixedSize(field_->type()).has_value();
@@ -668,6 +671,7 @@ void RepeatedPrimitive::GenerateByteSize(io::Printer* p) const {
         total_size += tag_size + data_size;
       )cc");
 }
+
 }  // namespace
 
 std::unique_ptr<FieldGeneratorBase> MakeSinguarPrimitiveGenerator(

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

@@ -243,6 +243,20 @@ bool HasV2Table(const Descriptor* descriptor, const Options& options) {
 
 }  // namespace
 
+bool EligibleForCompactV2Fields(const Descriptor* desc) {
+  for (int i = 0; i < desc->field_count(); ++i) {
+    if (desc->field(i)->number() >= std::numeric_limits<uint8_t>::max()) {
+      return false;
+    }
+  }
+  for (int i = 0; i < desc->extension_count(); ++i) {
+    if (desc->extension(i)->number() >= std::numeric_limits<uint8_t>::max()) {
+      return false;
+    }
+  }
+  return true;
+}
+
 bool IsLazy(const FieldDescriptor* field, const Options& options,
             MessageSCCAnalyzer* scc_analyzer) {
   return IsLazilyVerifiedLazy(field, options) ||

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

@@ -46,6 +46,10 @@ namespace compiler {
 namespace cpp {
 enum class ArenaDtorNeeds { kNone = 0, kOnDemand = 1, kRequired = 2 };
 
+// Returns true if the message is eligible for compact v2 fields, i.e. all field
+// numbers can be stored in a uint8_t.
+bool EligibleForCompactV2Fields(const Descriptor* desc);
+
 inline absl::string_view ProtobufNamespace(const Options& opts) {
   // This won't be transformed by copybara, since copybara looks for google::protobuf::.
   constexpr absl::string_view kGoogle3Ns = "proto2";

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

@@ -1377,7 +1377,8 @@ class AccessorVerifier {
 
 template <bool kIsV2>
 void MessageGenerator::EmitCheckAndUpdateByteSizeForField(
-    const FieldDescriptor* field, io::Printer* p, bool try_batch) const {
+    const FieldDescriptor* field, io::Printer* p, bool try_batch,
+    bool use_compact_field_numbers) const {
   absl::AnyInvocable<void()> emit_body = [&] {
     const auto& gen = field_generators_.get(field);
     if constexpr (!kIsV2) {
@@ -1447,7 +1448,8 @@ void MessageGenerator::EmitUpdateByteSizeForField(
        {"check_and_update_byte_size_for_field",
         [&]() {
           EmitCheckAndUpdateByteSizeForField</*kIsV2=*/false>(
-              field, p, /*try_batch=*/false);
+              field, p, /*try_batch=*/false,
+              /*use_compact_field_numbers=*/false);
         }}},
       R"cc(
         $comment$;

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

@@ -214,7 +214,8 @@ class MessageGenerator {
   // Helper functions to reduce nesting levels of deep Emit calls.
   template <bool kIsV2 = false>
   void EmitCheckAndUpdateByteSizeForField(const FieldDescriptor* field,
-                                          io::Printer* p, bool try_batch) const;
+                                          io::Printer* p, bool try_batch,
+                                          bool compact_field_numbers) const;
   void EmitUpdateByteSizeForField(const FieldDescriptor* field, io::Printer* p,
                                   int& cached_has_word_index) const;