Refactor PrintFieldComment in protoc to use io::Printer and Emit.

PiperOrigin-RevId: 1002701946

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

diff --git a/src/google/protobuf/compiler/cpp/helpers.h b/src/google/protobuf/compiler/cpp/helpers.h
index db4003c..b63fdec 100644
--- a/src/google/protobuf/compiler/cpp/helpers.h
+++ b/src/google/protobuf/compiler/cpp/helpers.h
@@ -1077,9 +1077,10 @@
 }
 
 template <class T>
-void PrintFieldComment(const Formatter& format, const T* field,
-                       const Options& options) {
-  format("// $1$\n", FieldComment(field, options));
+void PrintFieldComment(io::Printer* p, const T* field, const Options& options) {
+  p->Emit({{"comment", FieldComment(field, options)}}, R"cc(
+    // $comment$
+  )cc");
 }
 
 class PROTOC_EXPORT NamespaceOpener {

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

diff --git a/src/google/protobuf/compiler/cpp/message.cc b/src/google/protobuf/compiler/cpp/message.cc
index 1659027..c7c8a7b 100644
--- a/src/google/protobuf/compiler/cpp/message.cc
+++ b/src/google/protobuf/compiler/cpp/message.cc
@@ -1283,7 +1283,7 @@
     const FieldDescriptor* field, io::Printer* p,
     int& cached_has_word_index) const {
   p->Emit(
-      {{"comment", [&] { PrintFieldComment(Formatter{p}, field, options_); }},
+      {{"comment", [&] { PrintFieldComment(p, field, options_); }},
        {"update_cached_has_bits",
         [&] { MaybeEmitUpdateCachedHasbits(field, p, cached_has_word_index); }},
        {"check_and_update_byte_size_for_field",
@@ -1312,7 +1312,7 @@
     const auto accessor_verifier =
         p->WithSubstitutionListener(AccessorVerifier(field));
 
-    PrintFieldComment(Formatter{p}, field, options_);
+    PrintFieldComment(p, field, options_);
 
     auto v = p->WithVars(FieldVars(field, options_));
     auto t = p->WithVars(MakeTrackerCalls(field, options_));
@@ -4252,7 +4252,7 @@
     field_generators_.get(field).GenerateSerializeWithCachedSizesToArray(p);
   };
 
-  PrintFieldComment(Formatter{p}, field, options_);
+  PrintFieldComment(p, field, options_);
   if (HasHasbit(field, options_)) {
     int has_bit_index = field_layout_.GetHasBitIndex(field).value();
     int has_word_index = field_layout_.GetHasWordIndex(field).value();
@@ -4997,7 +4997,7 @@
                  {"case_per_field",
                   [&] {
                     for (auto field : internal::FieldRange(oneof)) {
-                      PrintFieldComment(Formatter{p}, field, options_);
+                      PrintFieldComment(p, field, options_);
                       p->Emit(
                           {{"field_name",
                             UnderscoresToCamelCase(field->name(), true)},
@@ -5086,7 +5086,7 @@
              {"case_per_field",
               [&] {
                 for (auto field : internal::FieldRange(oneof)) {
-                  PrintFieldComment(Formatter{p}, field, options_);
+                  PrintFieldComment(p, field, options_);
                   p->Emit({{"field_name",
                             UnderscoresToCamelCase(field->name(), true)},
                            {"field_byte_size", [&] { emitter(p, field); }}},

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

diff --git a/src/google/protobuf/compiler/cpp/parse_function_generator.cc b/src/google/protobuf/compiler/cpp/parse_function_generator.cc
index b479a18..b4080ea 100644
--- a/src/google/protobuf/compiler/cpp/parse_function_generator.cc
+++ b/src/google/protobuf/compiler/cpp/parse_function_generator.cc
@@ -464,16 +464,14 @@
                 {$target$, {$coded_tag$, ::uint16_t{$nonfield_info$}}},
               )cc");
     } else if (auto* mp_field = info.AsMpField()) {
-      {
-        // TODO: refactor this to use Emit.
-        Formatter format(p, variables_);
-        PrintFieldComment(format, mp_field->field, options_);
-      }
-      p->Emit({{"target", TcParseFunctionName(mp_field->func)},
+      p->Emit({{"comment",
+                [&] { PrintFieldComment(p, mp_field->field, options_); }},
+               {"target", TcParseFunctionName(mp_field->func)},
                {"coded_tag", mp_field->coded_tag},
                {"function_index", mp_field->function_index},
                {"index", mp_field->field_index}},
               R"cc(
+                $comment$;
                 {$target$,
                  {$coded_tag$, ::uint8_t{$function_index$},
                   ::uint32_t{
@@ -481,11 +479,6 @@
                       sizeof(_pbi::TcParseTableBase::FieldEntry) * $index$}}},
               )cc");
     } else if (auto* as_field = info.AsField()) {
-      {
-        // TODO: refactor this to use Emit.
-        Formatter format(p, variables_);
-        PrintFieldComment(format, as_field->field, options_);
-      }
       ABSL_CHECK(!ShouldSplit(as_field->field, options_));
 
       std::string func_name = TcParseFunctionName(as_field->func);
@@ -514,6 +507,8 @@
 
       p->Emit(
           {
+              {"comment",
+               [&] { PrintFieldComment(p, as_field->field, options_); }},
               {"target", func_name},
               {"coded_tag", as_field->coded_tag},
               {"hasbit_idx", as_field->hasbit_idx},
@@ -521,6 +516,7 @@
               {"field_name", FieldMemberName(as_field->field, /*split=*/false)},
           },
           R"cc(
+            $comment$;
             {$target$,
              {$coded_tag$, $hasbit_idx$, $aux_idx$,
               PROTOBUF_FIELD_OFFSET($Msg$, $field_name$)}},
@@ -537,9 +533,6 @@
 void ParseFunctionGenerator::GenerateFieldEntries(io::Printer* p) {
   for (const auto& entry : tc_table_info_->field_entries) {
     const FieldDescriptor* field = entry.field;
-    // TODO: refactor this to use Emit.
-    Formatter format(p, variables_);
-    PrintFieldComment(format, field, options_);
 
     bool weak = IsWeak(field, options_);
     bool split = ShouldSplit(field, options_);
@@ -549,7 +542,8 @@
         {{"field_name", FieldName(field)},
          {"field_member_name", FieldMemberName(field, /*split=*/false)}});
 
-    p->Emit({{"offset",
+    p->Emit({{"comment", [&] { PrintFieldComment(p, field, options_); }},
+             {"offset",
               [&] {
                 if (weak) {
                   p->Emit("/* weak */ 0,");
@@ -580,6 +574,7 @@
             // Use `0|` prefix to eagerly convert the enums to int to avoid
             // enum-enum operations. They are deprecated in C++20.
             R"cc(
+              $comment$;
               {$offset$, $has_idx$, $aux_idx$, (0 | $type_card$)},
             )cc");
   }