[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, 11 insertions, 0 deletions

diff --git a/backend/include/rcc/CodeGen/MachineInstr.h b/backend/include/rcc/CodeGen/MachineInstr.h
index 78d48cb..69d7dd7 100644
--- a/backend/include/rcc/CodeGen/MachineInstr.h
+++ b/backend/include/rcc/CodeGen/MachineInstr.h
@@ -121,6 +121,16 @@ public:
     Location.reset();
   }
 
+  [[nodiscard]] const std::optional<MachineDebugLocation> &debugLocation() const noexcept {
+    return DebugLocation;
+  }
+
+  [[nodiscard]] Expected<void> setDebugLocation(MachineDebugLocation NewLocation);
+
+  void clearDebugLocation() noexcept {
+    DebugLocation.reset();
+  }
+
   [[nodiscard]] std::optional<OriginID> origin() const noexcept {
     return Origin;
   }
@@ -164,6 +174,7 @@ private:
   std::vector<const MachineMemOperand *> MemOperands;
   MachineInstrFlags Flags;
   std::optional<SourceLocation> Location;
+  std::optional<MachineDebugLocation> DebugLocation;
   std::optional<OriginID> Origin;
   std::uint32_t DebugInstrNumber = 0;