Make NamespaceOpener track source locations

PiperOrigin-RevId: 554504627

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

@@ -1190,7 +1190,8 @@ bool IsWellKnownMessage(const FileDescriptor* file) {
   return well_known_files->find(file->name()) != well_known_files->end();
 }
 
-void NamespaceOpener::ChangeTo(absl::string_view name) {
+void NamespaceOpener::ChangeTo(absl::string_view name,
+                               io::Printer::SourceLocation loc) {
   std::vector<std::string> new_stack =
       absl::StrSplit(name, "::", absl::SkipEmpty());
   size_t len = std::min(name_stack_.size(), new_stack.size());
@@ -1205,12 +1206,14 @@ void NamespaceOpener::ChangeTo(absl::string_view name) {
   for (size_t i = name_stack_.size(); i > common_idx; i--) {
     p_->Emit({{"ns", name_stack_[i - 1]}}, R"(
       }  // namespace $ns$
-    )");
+    )",
+             loc);
   }
   for (size_t i = common_idx; i < new_stack.size(); ++i) {
     p_->Emit({{"ns", new_stack[i]}}, R"(
       namespace $ns$ {
-    )");
+    )",
+             loc);
   }
 
   name_stack_ = std::move(new_stack);

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

@@ -979,21 +979,37 @@ void PrintFieldComment(const Formatter& format, const T* field,
 
 class PROTOC_EXPORT NamespaceOpener {
  public:
-  explicit NamespaceOpener(io::Printer* p) : p_(p) {}
-  explicit NamespaceOpener(const Formatter& format) : p_(format.printer()) {}
-  NamespaceOpener(absl::string_view name, const Formatter& format)
-      : NamespaceOpener(format) {
-    ChangeTo(name);
-  }
-  NamespaceOpener(absl::string_view name, io::Printer* p) : NamespaceOpener(p) {
-    ChangeTo(name);
+  explicit NamespaceOpener(
+      io::Printer* p,
+      io::Printer::SourceLocation loc = io::Printer::SourceLocation::current())
+      : p_(p), loc_(loc) {}
+
+  explicit NamespaceOpener(
+      const Formatter& format,
+      io::Printer::SourceLocation loc = io::Printer::SourceLocation::current())
+      : NamespaceOpener(format.printer(), loc) {}
+
+  NamespaceOpener(
+      absl::string_view name, const Formatter& format,
+      io::Printer::SourceLocation loc = io::Printer::SourceLocation::current())
+      : NamespaceOpener(name, format.printer(), loc) {}
+
+  NamespaceOpener(
+      absl::string_view name, io::Printer* p,
+      io::Printer::SourceLocation loc = io::Printer::SourceLocation::current())
+      : NamespaceOpener(p, loc) {
+    ChangeTo(name, loc);
   }
-  ~NamespaceOpener() { ChangeTo(""); }
 
-  void ChangeTo(absl::string_view name);
+  ~NamespaceOpener() { ChangeTo("", loc_); }
+
+  void ChangeTo(
+      absl::string_view name,
+      io::Printer::SourceLocation loc = io::Printer::SourceLocation::current());
 
  private:
   io::Printer* p_;
+  io::Printer::SourceLocation loc_;
   std::vector<std::string> name_stack_;
 };