[torque] Emit source position comments to generated files

Change-Id: I36d230fa3e51eb27109a8dd2adc0e7802fc77a7d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3177221Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77007}

src/torque/cpp-builder.cc

@@ -14,6 +14,8 @@ void Function::PrintDeclarationHeader(std::ostream& stream,
   if (!description_.empty()) {
     stream << std::string(indentation, ' ') << "// " << description_ << "\n";
   }
+  stream << std::string(indentation, ' ') << "// " << PositionAsString(pos_)
+         << "\n";
   stream << std::string(indentation, ' ');
   if (IsExport()) stream << "V8_EXPORT_PRIVATE ";
   if (IsV8Inline())
@@ -63,6 +65,8 @@ void Function::PrintInlineDefinition(
 
 void Function::PrintBeginDefinition(std::ostream& stream,
                                     int indentation) const {
+  stream << std::string(indentation, ' ') << "// " << PositionAsString(pos_)
+         << "\n";
   std::string scope;
   if (owning_class_) {
     scope = owning_class_->GetName();

src/torque/cpp-builder.h

@@ -71,9 +71,13 @@ class Function {
   };
 
   explicit Function(std::string name)
-      : owning_class_(nullptr), name_(std::move(name)) {}
+      : pos_(CurrentSourcePosition::Get()),
+        owning_class_(nullptr),
+        name_(std::move(name)) {}
   Function(Class* owning_class, std::string name)
-      : owning_class_(owning_class), name_(std::move(name)) {}
+      : pos_(CurrentSourcePosition::Get()),
+        owning_class_(owning_class),
+        name_(std::move(name)) {}
   ~Function() = default;
 
   static Function DefaultGetter(std::string return_type, Class* owner,
@@ -159,6 +163,7 @@ class Function {
   void PrintDeclarationHeader(std::ostream& stream, int indentation) const;
 
  private:
+  SourcePosition pos_;
   Class* owning_class_;
   std::string description_;
   std::string name_;

src/torque/implementation-visitor.cc

@@ -3726,6 +3726,7 @@ class MacroFieldOffsetsGenerator : public FieldOffsetsGenerator {
          << "_FIELDS(V) \\\n";
   }
   void WriteField(const Field& f, const std::string& size_string) override {
+    out_ << "/* " << PositionAsString(f.pos) << " */ \\\n";
     out_ << "V(k" << CamelifyString(f.name_and_type.name) << "Offset, "
          << size_string << ") \\\n";
   }
@@ -3868,7 +3869,9 @@ class ClassFieldOffsetGenerator : public FieldOffsetsGenerator {
         previous_field_end_((parent && parent->IsShape()) ? "P::kSize"
                                                           : "P::kHeaderSize"),
         gen_name_(gen_name) {}
+
   void WriteField(const Field& f, const std::string& size_string) override {
+    hdr_ << "  // " << PositionAsString(f.pos) << "\n";
     std::string field = "k" + CamelifyString(f.name_and_type.name) + "Offset";
     std::string field_end = field + "End";
     hdr_ << "  static constexpr int " << field << " = " << previous_field_end_
@@ -3877,6 +3880,7 @@ class ClassFieldOffsetGenerator : public FieldOffsetsGenerator {
          << size_string << " - 1;\n";
     previous_field_end_ = field_end + " + 1";
   }
+
   void WriteFieldOffsetGetter(const Field& f) override {
     // A static constexpr int is more convenient than a getter if the offset is
     // known.
@@ -3929,6 +3933,8 @@ class CppClassGenerator {
   void GenerateClass();
 
  private:
+  SourcePosition Position();
+
   void GenerateClassConstructors();
 
   // Generates getter and setter runtime member functions for the given class
@@ -4001,7 +4007,7 @@ void CppClassGenerator::GenerateClass() {
       stream << "  return o.Is" << name_ << "();";
     });
   }
-
+  hdr_ << "// Definition" << PositionAsString(Position()) << "\n";
   hdr_ << template_decl() << "\n";
   hdr_ << "class " << gen_name_ << " : public P {\n";
   hdr_ << "  static_assert(std::is_same<" << name_ << ", D>::value,\n"
@@ -4016,6 +4022,7 @@ void CppClassGenerator::GenerateClass() {
     hdr_ << " protected: // not extern or @export\n";
   }
   for (const Field& f : type_->fields()) {
+    CurrentSourcePosition::Scope scope(f.pos);
     std::vector<const Field*> struct_fields;
     GenerateFieldAccessors(f, struct_fields);
   }
@@ -4181,6 +4188,8 @@ void CppClassGenerator::GenerateClassCasts() {
   });
 }
 
+SourcePosition CppClassGenerator::Position() { return type_->GetPosition(); }
+
 void CppClassGenerator::GenerateClassConstructors() {
   const ClassType* typecheck_type = type_;
   while (typecheck_type->IsShape()) {
@@ -4619,6 +4628,7 @@ void ImplementationVisitor::GenerateClassDefinitions(
 
     // Emit forward declarations.
     for (const ClassType* type : TypeOracle::GetClasses()) {
+      CurrentSourcePosition::Scope position_activator(type->GetPosition());
       auto& streams = GlobalContext::GeneratedPerFile(type->AttributedToFile());
       std::ostream& header = streams.class_definition_headerfile;
       std::string name = type->GenerateCppClassDefinitions()
@@ -4629,6 +4639,7 @@ void ImplementationVisitor::GenerateClassDefinitions(
     }
 
     for (const ClassType* type : TypeOracle::GetClasses()) {
+      CurrentSourcePosition::Scope position_activator(type->GetPosition());
       auto& streams = GlobalContext::GeneratedPerFile(type->AttributedToFile());
       std::ostream& header = streams.class_definition_headerfile;
       std::ostream& inline_header = streams.class_definition_inline_headerfile;
@@ -4730,6 +4741,7 @@ void ImplementationVisitor::GenerateClassDefinitions(
     }
 
     for (const StructType* type : structs_used_in_classes) {
+      CurrentSourcePosition::Scope position_activator(type->GetPosition());
       std::ostream& header =
           GlobalContext::GeneratedPerFile(type->GetPosition().source)
               .class_definition_headerfile;
@@ -5294,6 +5306,7 @@ void ImplementationVisitor::GenerateExportedMacrosAssembler(
     for (auto& declarable : GlobalContext::AllDeclarables()) {
       TorqueMacro* macro = TorqueMacro::DynamicCast(declarable.get());
       if (!(macro && macro->IsExportedToCSA())) continue;
+      CurrentSourcePosition::Scope position_activator(macro->Position());
 
       cpp::Class assembler("TorqueGeneratedExportedMacrosAssembler");
       std::vector<std::string> generated_parameter_names;