Internal change.

PiperOrigin-RevId: 546314630

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

@@ -896,6 +896,11 @@ bool IsRarelyPresent(const FieldDescriptor* field, const Options& options) {
   return false;
 }
 
+float GetPresenceProbability(const FieldDescriptor* field,
+                             const Options& options) {
+  return 1.f;
+}
+
 bool IsStringInlined(const FieldDescriptor* field, const Options& options) {
   (void)field;
   (void)options;

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

@@ -367,6 +367,9 @@ bool IsProfileDriven(const Options& options);
 // Returns true if `field` is unlikely to be present based on PDProto profile.
 bool IsRarelyPresent(const FieldDescriptor* field, const Options& options);
 
+float GetPresenceProbability(const FieldDescriptor* field,
+                             const Options& options);
+
 // Returns true if `field` should be inlined based on PDProto profile.
 bool IsStringInlined(const FieldDescriptor* field, const Options& options);
 

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

@@ -114,6 +114,7 @@ class ParseFunctionGenerator::GeneratedOptionProvider final
       return internal::field_layout::TransformValidation{};
     };
     return {
+        GetPresenceProbability(field, gen_->options_),
         verify_flag(),
         IsStringInlined(field, gen_->options_),
         IsImplicitWeakField(field, gen_->options_, gen_->scc_analyzer_),

src/google/protobuf/generated_message_reflection.cc

@@ -3391,6 +3391,7 @@ const internal::TcParseTableBase* Reflection::CreateTcParseTable() const {
         return internal::field_layout::TransformValidation{};
       };
       return {
+          1.f,                    // All fields are assumed present.
           verify_flag(),          //
           ref_.IsInlined(field),  //
 

src/google/protobuf/generated_message_tctable_gen.cc

@@ -391,12 +391,18 @@ std::vector<TailCallTableInfo::FastFieldInfo> SplitFastFieldsForSize(
 
     TailCallTableInfo::FastFieldInfo& info = result[fast_idx];
     if (!info.func_name.empty()) {
-      // This field entry is already filled.
+      // Null field means END_GROUP which is guaranteed to be present.
-      continue;
+      if (info.field == nullptr) continue;
+
+      // This field entry is already filled. Skip if previous entry is more
+      // likely present.
+      const auto prev_options = option_provider.GetForField(info.field);
+      if (prev_options.presence_probability >= options.presence_probability) {
+        continue;
+      }
     }
 
     // Fill in this field's entry:
-    ABSL_CHECK(info.func_name.empty()) << info.func_name;
     PopulateFastFieldEntry(entry, options, info);
     info.field = field;
     info.coded_tag = tag;

src/google/protobuf/generated_message_tctable_gen.h

@@ -57,6 +57,8 @@ enum TransformValidation : uint16_t;
 // Helper class for generating tailcall parsing functions.
 struct PROTOBUF_EXPORT TailCallTableInfo {
   struct PerFieldOptions {
+    // For presence awareness (e.g. PDProto).
+    float presence_probability;
     // kTvEager, kTvLazy, or 0
     field_layout::TransformValidation lazy_opt;
     bool is_string_inlined;