From 1c2ea908abd8944ac306a3af0a3a643633615b38 Mon Sep 17 00:00:00 2001
From: Protobuf Team Bot <protobuf-github-bot@google.com>
Date: Tue, 21 Jan 2025 12:58:46 -0800
Subject: [PATCH] Modify GetEmitRepeatedFieldMutableSub to take in a
 FieldDescriptor instead of a boolean and ensure split is enabled for string
 piece.

PiperOrigin-RevId: 718036356
---
 .../cpp/field_generators/message_field.cc       |  2 +-
 .../cpp/field_generators/string_field.cc        |  2 +-
 .../cpp/field_generators/string_view_field.cc   |  2 +-
 src/google/protobuf/compiler/cpp/helpers.h      | 17 +++++++++++------
 4 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/google/protobuf/compiler/cpp/field_generators/message_field.cc b/src/google/protobuf/compiler/cpp/field_generators/message_field.cc
index 30496c9522ac4..b6f9bd169c0fa 100644
--- a/src/google/protobuf/compiler/cpp/field_generators/message_field.cc
+++ b/src/google/protobuf/compiler/cpp/field_generators/message_field.cc
@@ -783,7 +783,7 @@ void RepeatedMessage::GenerateAccessorDeclarations(io::Printer* p) const {
 
 void RepeatedMessage::GenerateInlineAccessorDefinitions(io::Printer* p) const {
   // TODO: move insertion points
-  p->Emit({GetEmitRepeatedFieldMutableSub(*opts_, p)},
+  p->Emit({GetEmitRepeatedFieldMutableSub(*opts_, p, field_)},
           R"cc(
             inline $Submsg$* $nonnull$ $Msg$::mutable_$name$(int index)
                 ABSL_ATTRIBUTE_LIFETIME_BOUND {
diff --git a/src/google/protobuf/compiler/cpp/field_generators/string_field.cc b/src/google/protobuf/compiler/cpp/field_generators/string_field.cc
index f135cd2f76462..071c71be5461f 100644
--- a/src/google/protobuf/compiler/cpp/field_generators/string_field.cc
+++ b/src/google/protobuf/compiler/cpp/field_generators/string_field.cc
@@ -858,7 +858,7 @@ void RepeatedString::GenerateInlineAccessorDefinitions(io::Printer* p) const {
                p->Emit(", $pbi$::BytesTag{}");
              }
            }},
-          GetEmitRepeatedFieldMutableSub(*opts_, p),
+          GetEmitRepeatedFieldMutableSub(*opts_, p, field_),
       },
       R"cc(
         inline std::string* $nonnull$ $Msg$::add_$name$()
diff --git a/src/google/protobuf/compiler/cpp/field_generators/string_view_field.cc b/src/google/protobuf/compiler/cpp/field_generators/string_view_field.cc
index 7c85ca9fa7974..27fa4dac2fa5b 100644
--- a/src/google/protobuf/compiler/cpp/field_generators/string_view_field.cc
+++ b/src/google/protobuf/compiler/cpp/field_generators/string_view_field.cc
@@ -669,7 +669,7 @@ void RepeatedStringView::GenerateInlineAccessorDefinitions(
   p->Emit(
       {
           {GetEmitRepeatedFieldGetterSub(*opts_, p)},
-          {GetEmitRepeatedFieldMutableSub(*opts_, p)},
+          {GetEmitRepeatedFieldMutableSub(*opts_, p, field_)},
       },
       R"cc(
         inline absl::string_view $Msg$::$name$(int index) const
diff --git a/src/google/protobuf/compiler/cpp/helpers.h b/src/google/protobuf/compiler/cpp/helpers.h
index d7092c51e3751..c7eb7632d8a3c 100644
--- a/src/google/protobuf/compiler/cpp/helpers.h
+++ b/src/google/protobuf/compiler/cpp/helpers.h
@@ -1216,18 +1216,23 @@ inline auto GetEmitRepeatedFieldGetterSub(const Options& options,
 // Emit the code for getting a mutable element from a repeated field. This will
 // generate different code depending on the `bounds_check_mode` specified in the
 // options.
-// TODO: b/347304492 Harden this function by taking in the field and checking
-// if splitting is supported.
 inline auto GetEmitRepeatedFieldMutableSub(const Options& options,
                                            io::Printer* p,
-                                           bool use_stringpiecefield = false) {
+                                           const FieldDescriptor* field) {
+  bool is_stringpiecefield =
+      field->cpp_type() == FieldDescriptor::CPPTYPE_STRING &&
+      field->options().ctype() == FieldOptions::STRING;
+
+  if (is_stringpiecefield) {
+    // ABSL_CHECK(!IsSplitEnabledForField(field, options));
+  }
   return io::Printer::Sub{
       "mutable",
-      [&options, p, use_stringpiecefield] {
+      [&options, p, is_stringpiecefield] {
         switch (options.bounds_check_mode) {
           case BoundsCheckMode::kNoEnforcement:
           case BoundsCheckMode::kReturnDefaultValue:
-            if (use_stringpiecefield) {
+            if (is_stringpiecefield) {
               p->Emit("$field$.Mutable(index)");
             } else {
               p->Emit(
@@ -1235,7 +1240,7 @@ inline auto GetEmitRepeatedFieldMutableSub(const Options& options,
             }
             break;
           case BoundsCheckMode::kAbort:
-            if (use_stringpiecefield) {
+            if (is_stringpiecefield) {
               p->Emit("$pbi$::CheckedMutableOrAbort(&$field$, index)");
             } else {
               p->Emit(R"cc(