[CodeGen] Model machine debug metadata

Replace marker-based metadata operands with scoped references and inline DIExpression values. Add structured DILocation chains, instruction debug attachments, stack variable records, and entry values with unified verification, builder support, and deterministic cloning.

1 files changed, 5 insertions, 4 deletions

diff --git a/backend/lib/CodeGen/MachineOperand.cpp b/backend/lib/CodeGen/MachineOperand.cpp
index 0e5febd..cd2d217 100644
--- a/backend/lib/CodeGen/MachineOperand.cpp
+++ b/backend/lib/CodeGen/MachineOperand.cpp
@@ -158,11 +158,12 @@ Expected<MachineOperand> MachineOperand::registerMask(std::shared_ptr<const Regi
   return MachineOperand(Kind::RegisterMask, RegisterMaskOperand{std::move(Mask)}, TargetFlags);
 }
 
-Expected<MachineOperand> MachineOperand::metadata(std::string Marker, std::uint32_t TargetFlags) {
-  if (Marker.empty()) {
-    return makeUnexpected(ErrorCode::InvalidArgument, "metadata operand marker cannot be empty");
+Expected<MachineOperand> MachineOperand::metadata(MachineMetadataValue Value,
+                                                  std::uint32_t TargetFlags) {
+  if (!Value.isValid()) {
+    return makeUnexpected(ErrorCode::InvalidArgument, "metadata operand value must be valid");
   }
-  return MachineOperand(Kind::Metadata, MetadataOperand{std::move(Marker)}, TargetFlags);
+  return MachineOperand(Kind::Metadata, MetadataOperand{std::move(Value)}, TargetFlags);
 }
 
 MachineOperand MachineOperand::targetIndex(TargetIndex Index, std::int64_t Offset,