[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, 27 insertions, 0 deletions

diff --git a/backend/lib/CodeGen/MachineFunctionRecords.cpp b/backend/lib/CodeGen/MachineFunctionRecords.cpp
index 9fda0d7..0a21581 100644
--- a/backend/lib/CodeGen/MachineFunctionRecords.cpp
+++ b/backend/lib/CodeGen/MachineFunctionRecords.cpp
@@ -80,6 +80,14 @@ verifyDebugValueSubstitution(const MachineDebugValueSubstitution &Substitution)
   return {};
 }
 
+[[nodiscard]] Expected<void> verifyEntryValue(const MachineEntryValueInfo &EntryValue) {
+  if (!EntryValue.Reg.isValid()) {
+    return makeUnexpected(ErrorCode::VerificationError,
+                          "entry-value record requires a physical register");
+  }
+  return EntryValue.DebugInfo.verifyStructure();
+}
+
 } // namespace
 
 Expected<void>
@@ -143,6 +151,14 @@ MachineFunctionRecords::addDebugValueSubstitution(MachineDebugValueSubstitution
   return {};
 }
 
+Expected<void> MachineFunctionRecords::addEntryValue(MachineEntryValueInfo EntryValue) {
+  auto Verification = verifyEntryValue(EntryValue);
+  if (!Verification)
+    return std::unexpected(Verification.error());
+  EntryValues.push_back(std::move(EntryValue));
+  return {};
+}
+
 Expected<void> MachineFunctionRecords::verify() const {
   if (CalleeSavedRegisters) {
     auto CalleeSavedVerification = verifyCalleeSavedRegisters(*CalleeSavedRegisters);
@@ -210,6 +226,12 @@ Expected<void> MachineFunctionRecords::verify() const {
     }
     CompletedDebugReferences.insert(Path.begin(), Path.end());
   }
+
+  for (const MachineEntryValueInfo &EntryValue : EntryValues) {
+    auto EntryValueVerification = verifyEntryValue(EntryValue);
+    if (!EntryValueVerification)
+      return EntryValueVerification;
+  }
   return {};
 }
 
@@ -258,6 +280,11 @@ MachineFunctionRecords::clone(const MachineFunctionCloneContext &CloneContext) c
     if (!AddResult)
       return std::unexpected(AddResult.error());
   }
+  for (const MachineEntryValueInfo &Source : EntryValues) {
+    auto AddResult = Result.addEntryValue(Source);
+    if (!AddResult)
+      return std::unexpected(AddResult.error());
+  }
   return Result;
 }