[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, 16 insertions, 0 deletions

diff --git a/backend/include/rcc/CodeGen/MachineFunctionRecords.h b/backend/include/rcc/CodeGen/MachineFunctionRecords.h
index 7929ed3..b792494 100644
--- a/backend/include/rcc/CodeGen/MachineFunctionRecords.h
+++ b/backend/include/rcc/CodeGen/MachineFunctionRecords.h
@@ -4,6 +4,7 @@
 #define RCC_CODEGEN_MACHINEFUNCTIONRECORDS_H
 
 #include "rcc/CodeGen/MachineBasicBlockAttributes.h"
+#include "rcc/CodeGen/MachineDebugInfo.h"
 #include "rcc/CodeGen/Register.h"
 #include "rcc/CodeGen/StableID.h"
 #include "rcc/Support/Error.h"
@@ -37,6 +38,14 @@ struct MachineDebugValueSubstitution final {
                                    MachineDebugValueSubstitution Right) noexcept = default;
 };
 
+struct MachineEntryValueInfo final {
+  PhysicalRegister Reg;
+  MachineVariableDebugInfo DebugInfo;
+
+  friend bool operator==(const MachineEntryValueInfo &Left,
+                         const MachineEntryValueInfo &Right) = default;
+};
+
 struct MachineCallSiteArgument final {
   PhysicalRegister Reg;
   std::uint16_t ArgumentNumber = 0;
@@ -122,6 +131,12 @@ public:
   [[nodiscard]] Expected<void>
   addDebugValueSubstitution(MachineDebugValueSubstitution Substitution);
 
+  [[nodiscard]] std::span<const MachineEntryValueInfo> entryValues() const noexcept {
+    return EntryValues;
+  }
+
+  [[nodiscard]] Expected<void> addEntryValue(MachineEntryValueInfo EntryValue);
+
   [[nodiscard]] Expected<void> verify() const;
   [[nodiscard]] Expected<MachineFunctionRecords>
   clone(const MachineFunctionCloneContext &CloneContext) const;
@@ -135,6 +150,7 @@ private:
   std::vector<MachineCalledGlobal> CalledGlobals;
   std::vector<MachinePrefetchTarget> PrefetchTargets;
   std::vector<MachineDebugValueSubstitution> DebugValueSubstitutions;
+  std::vector<MachineEntryValueInfo> EntryValues;
 };
 
 } // namespace rcc