Remove the exception for multiple extension ranges for TDP.

It is unnecessary since the regular extension parser can handle unknown fields
directly.

PiperOrigin-RevId: 509946221

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

@@ -494,14 +494,10 @@ void ParseFunctionGenerator::GenerateTailCallTable(Formatter& format) {
       } else {
         format("0,  // no _has_bits_\n");
       }
-      if (descriptor_->extension_range_count() == 1) {
-        format(
-            "PROTOBUF_FIELD_OFFSET($classname$, $extensions$),\n"
-            "$1$, $2$,  // extension_range_{low,high}\n",
-            descriptor_->extension_range(0)->start,
-            descriptor_->extension_range(0)->end);
+      if (descriptor_->extension_range_count() != 0) {
+        format("PROTOBUF_FIELD_OFFSET($classname$, $extensions$),\n");
       } else {
-        format("0, 0, 0,  // no _extensions_\n");
+        format("0, // no _extensions_\n");
       }
       format("$1$, $2$,  // max_field_number, fast_idx_mask\n",
              (ordered_fields_.empty() ? 0 : ordered_fields_.back()->number()),

src/google/protobuf/generated_message_reflection.cc

@@ -3092,8 +3092,8 @@ const internal::TcParseTableBase* Reflection::CreateTcParseTableForMessageSet()
   // We use `operator new` here because the destruction will be done with
   // `operator delete` unconditionally.
   void* p = ::operator new(sizeof(Table));
-  auto* full_table = ::new (p) Table{
-      {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, schema_.default_instance_, nullptr},
+  auto* full_table = ::new (p)
+      Table{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, schema_.default_instance_, nullptr},
             {{{&internal::TcParser::ReflectionParseLoop, {}}}}};
   ABSL_DCHECK_EQ(static_cast<void*>(&full_table->header),
                  static_cast<void*>(full_table));
@@ -3292,14 +3292,19 @@ const internal::TcParseTableBase* Reflection::CreateTcParseTable() const {
   void* p = ::operator new(byte_size);
   auto* res = ::new (p) TcParseTableBase{
       static_cast<uint16_t>(schema_.HasHasbits() ? schema_.HasBitsOffset() : 0),
-      // extensions handled through reflection.
-      0, 0, 0,
+      schema_.HasExtensionSet()
+          ? static_cast<uint16_t>(schema_.GetExtensionSetOffset())
+          : uint16_t{0},
       static_cast<uint32_t>(fields.empty() ? 0 : fields.back()->number()),
-      static_cast<uint8_t>((fast_entries_count - 1) << 3), lookup_table_offset,
-      table_info.num_to_entry_table.skipmap32, field_entry_offset,
+      static_cast<uint8_t>((fast_entries_count - 1) << 3),
+      lookup_table_offset,
+      table_info.num_to_entry_table.skipmap32,
+      field_entry_offset,
       static_cast<uint16_t>(fields.size()),
-      static_cast<uint16_t>(table_info.aux_entries.size()), aux_offset,
-      schema_.default_instance_, &internal::TcParser::ReflectionFallback};
+      static_cast<uint16_t>(table_info.aux_entries.size()),
+      aux_offset,
+      schema_.default_instance_,
+      &internal::TcParser::ReflectionFallback};
 
   // Now copy the rest of the payloads
   PopulateTcParseFastEntries(table_info, res->fast_entry(0));

src/google/protobuf/generated_message_tctable_decl.h

@@ -170,8 +170,6 @@ struct alignas(uint64_t) TcParseTableBase {
   // Common attributes for message layout:
   uint16_t has_bits_offset;
   uint16_t extension_offset;
-  uint32_t extension_range_low;
-  uint32_t extension_range_high;
   uint32_t max_field_number;
   uint8_t fast_idx_mask;
   uint16_t lookup_table_offset;
@@ -194,7 +192,6 @@ struct alignas(uint64_t) TcParseTableBase {
   // compiled.
   constexpr TcParseTableBase(
       uint16_t has_bits_offset, uint16_t extension_offset,
-      uint32_t extension_range_low, uint32_t extension_range_high,
       uint32_t max_field_number, uint8_t fast_idx_mask,
       uint16_t lookup_table_offset, uint32_t skipmap32,
       uint32_t field_entries_offset, uint16_t num_field_entries,
@@ -202,8 +199,6 @@ struct alignas(uint64_t) TcParseTableBase {
       const MessageLite* default_instance, TailCallParseFunc fallback)
       : has_bits_offset(has_bits_offset),
         extension_offset(extension_offset),
-        extension_range_low(extension_range_low),
-        extension_range_high(extension_range_high),
         max_field_number(max_field_number),
         fast_idx_mask(fast_idx_mask),
         lookup_table_offset(lookup_table_offset),

src/google/protobuf/generated_message_tctable_gen.cc

@@ -824,8 +824,7 @@ TailCallTableInfo::TailCallTableInfo(
   // If there are no fallback fields, and at most one extension range, the
   // parser can use a generic fallback function. Otherwise, a message-specific
   // fallback routine is needed.
-  use_generated_fallback =
-      !fallback_fields.empty() || descriptor->extension_range_count() > 1;
+  use_generated_fallback = !fallback_fields.empty();
 }
 
 }  // namespace internal

src/google/protobuf/generated_message_tctable_impl.h

@@ -602,19 +602,22 @@ class PROTOBUF_EXPORT TcParser final {
       return ptr;
     }
 
-    uint32_t num = tag >> 3;
-    if (table->extension_range_low <= num &&
-        num <= table->extension_range_high) {
+    if (table->extension_offset != 0) {
+      // We don't need to check the extension ranges. If it is not an extension
+      // it will be handled just like if it was an unknown extension: sent to
+      // the unknown field set.
       return RefAt<ExtensionSet>(msg, table->extension_offset)
           .ParseField(tag, ptr,
                       static_cast<const MessageBaseT*>(table->default_instance),
                       &msg->_internal_metadata_, ctx);
-    }
-
+    } else {
+      // Otherwise, we directly put it on the unknown field set.
       return UnknownFieldParse(
-        tag, msg->_internal_metadata_.mutable_unknown_fields<UnknownFieldsT>(),
+          tag,
+          msg->_internal_metadata_.mutable_unknown_fields<UnknownFieldsT>(),
           ptr, ctx);
     }
+  }
 
   // Note: `inline` is needed on template function declarations below to avoid
   // -Wattributes diagnostic in GCC.

src/google/protobuf/generated_message_tctable_lite_test.cc

@@ -94,7 +94,7 @@ TEST(FastVarints, NameHere) {
   const TcParseTable<0, 1, 0, 0, 2> parse_table = {
       {
           kHasBitsOffset,  //
-          0, 0, 0,         // no _extensions_
+          0,               // no _extensions_
           1, 0,            // max_field_number, fast_idx_mask
           offsetof(decltype(parse_table), field_lookup_table),
           0xFFFFFFFF - 1,  // skipmap
@@ -285,7 +285,7 @@ TEST(IsEntryForFieldNumTest, Matcher) {
   TcParseTable<0, 3, 0, 0, 2> table = {
       // header:
       {
-          0, 0, 0, 0,  // has_bits_offset, extensions
+          0, 0,  // has_bits_offset, extensions
           0,     // max_field_number
           0,     // fast_idx_mask,
           offsetof(decltype(table), field_lookup_table),
@@ -352,7 +352,7 @@ TEST_F(FindFieldEntryTest, SequentialFieldRange) {
   TcParseTable<0, 5, 0, 0, 8> table = {
       // header:
       {
-          0, 0, 0, 0,  // has_bits_offset, extensions
+          0, 0,  // has_bits_offset, extensions
           111,   // max_field_number
           0,     // fast_idx_mask,
           offsetof(decltype(table), field_lookup_table),
@@ -393,7 +393,7 @@ TEST_F(FindFieldEntryTest, SmallScanRange) {
   TcParseTable<0, 6, 0, 0, 8> table = {
       // header:
       {
-          0, 0, 0, 0,  // has_bits_offset, extensions
+          0, 0,  // has_bits_offset, extensions
           111,   // max_field_number
           0,     // fast_idx_mask,
           offsetof(decltype(table), field_lookup_table),
@@ -439,7 +439,7 @@ TEST_F(FindFieldEntryTest, BinarySearchRange) {
   TcParseTable<0, 10, 0, 0, 8> table = {
       // header:
       {
-          0, 0, 0, 0,  // has_bits_offset, extensions
+          0, 0,  // has_bits_offset, extensions
           70,    // max_field_number
           0,     // fast_idx_mask,
           offsetof(decltype(table), field_lookup_table),
@@ -485,7 +485,7 @@ TEST_F(FindFieldEntryTest, OutOfRange) {
   TcParseTable<0, 3, 0, 15, 2> table = {
       // header:
       {
-          0, 0, 0, 0,  // has_bits_offset, extensions
+          0, 0,  // has_bits_offset, extensions
           3,     // max_field_number
           0,     // fast_idx_mask,
           offsetof(decltype(table), field_lookup_table),
@@ -535,7 +535,7 @@ TEST_F(FindFieldEntryTest, EmptyMessage) {
   TableType table = {
       // header:
       {
-          0, 0, 0, 0,  // has_bits_offset, extensions
+          0, 0,  // has_bits_offset, extensions
           0,     // max_field_number
           0,     // fast_idx_mask,
           offsetof(decltype(table), field_lookup_table),
@@ -586,7 +586,7 @@ int32_t test_all_types_table_field_numbers[] = {
 const TcParseTable<5, 134, 5, 2176, 55> test_all_types_table = {
     // header:
     {
-        0, 0, 0, 0,  // has_bits_offset, extensions
+        0, 0,  // has_bits_offset, extensions
         418, 248,    // max_field_number, fast_idx_mask
         offsetof(decltype(test_all_types_table), field_lookup_table),
         977895424,  // skipmap for fields 1-15,18-19,21-22,24-25,27,31-32