[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, 12 insertions, 4 deletions

diff --git a/backend/unittests/CodeGen/MachineIRCoreTest.cpp b/backend/unittests/CodeGen/MachineIRCoreTest.cpp
index 1083422..028afc5 100644
--- a/backend/unittests/CodeGen/MachineIRCoreTest.cpp
+++ b/backend/unittests/CodeGen/MachineIRCoreTest.cpp
@@ -169,10 +169,18 @@ void testOperandKinds(TestContext &Context) {
   Context.expect(!rcc::MachineOperand::registerMask(nullptr),
                  "null register mask operand must be rejected");
 
-  auto Metadata = rcc::MachineOperand::metadata("source-marker");
-  Context.expect(Metadata && Metadata->kind() == rcc::MachineOperand::Kind::Metadata,
-                 "metadata operand must preserve its kind");
-  Context.expect(!rcc::MachineOperand::metadata(""), "empty metadata marker must be rejected");
+  auto MetadataReference =
+      rcc::MachineMetadataValue::reference(rcc::MachineMetadataReference::embeddedIR(0));
+  Context.expect(MetadataReference.has_value(),
+                 "a valid scoped metadata reference must form an operand value");
+  if (!MetadataReference)
+    return;
+  auto Metadata = rcc::MachineOperand::metadata(std::move(*MetadataReference));
+  Context.expect(Metadata && Metadata->kind() == rcc::MachineOperand::Kind::Metadata &&
+                     Metadata->getIf<rcc::MetadataOperand>()->Value.reference() != nullptr,
+                 "metadata operand must preserve its scoped semantic value");
+  Context.expect(!rcc::MachineOperand::metadata({}),
+                 "an unrepresented metadata operand value must be rejected");
 
   auto Target = rcc::MachineOperand::targetIndex(rcc::TargetIndex::fromValue(8), 9);
   Context.expect(Target.getIf<rcc::TargetIndexOperand>()->Offset == 9,