[SILVerifier] Verify that debug variable types match the SSA type

(cherry picked from commit ac865eb)

Author: Snowy1803

lib/SIL/Verifier/SILVerifier.cpp

@@ -1465,39 +1465,34 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
 
   void checkDebugVariable(SILInstruction *inst) {
     std::optional<SILDebugVariable> varInfo;
-    if (auto *di = dyn_cast<AllocStackInst>(inst))
-      varInfo = di->getVarInfo();
-    else if (auto *di = dyn_cast<AllocBoxInst>(inst))
-      varInfo = di->getVarInfo();
-    else if (auto *di = dyn_cast<DebugValueInst>(inst))
-      varInfo = di->getVarInfo();
+    if (auto di = DebugVarCarryingInst(inst))
+      varInfo = di.getVarInfo();
 
     if (!varInfo)
       return;
 
     // Retrieve debug variable type
-    SILType DebugVarTy;
-    if (varInfo->Type)
-      DebugVarTy = *varInfo->Type;
-    else {
-      // Fetch from related SSA value
-      switch (inst->getKind()) {
-      case SILInstructionKind::AllocStackInst:
-      case SILInstructionKind::AllocBoxInst:
-        DebugVarTy = inst->getResult(0)->getType();
-        break;
-      case SILInstructionKind::DebugValueInst:
-        DebugVarTy = inst->getOperand(0)->getType();
-        if (DebugVarTy.isAddress()) {
-          // FIXME: op_deref could be applied to address types only.
-          // FIXME: Add this check
-          if (varInfo->DIExpr.startsWithDeref())
-            DebugVarTy = DebugVarTy.getObjectType();
-        }
-        break;
-      default:
-        llvm_unreachable("impossible instruction kind");
-      }
+    SILType SSAType;
+    switch (inst->getKind()) {
+    case SILInstructionKind::AllocStackInst:
+    case SILInstructionKind::AllocBoxInst:
+      // TODO: unwrap box for AllocBox
+      SSAType = inst->getResult(0)->getType().getObjectType();
+      break;
+    case SILInstructionKind::DebugValueInst:
+      SSAType = inst->getOperand(0)->getType();
+      break;
+    default:
+      llvm_unreachable("impossible instruction kind");
+    }
+    
+    SILType DebugVarTy = varInfo->Type ? *varInfo->Type :
+      SSAType.getObjectType();
+    if (!varInfo->DIExpr && !isa<AllocBoxInst>(inst)) {
+      // FIXME: Remove getObjectType() below when we fix create/createAddr
+      require(DebugVarTy.removingMoveOnlyWrapper()
+              == SSAType.getObjectType().removingMoveOnlyWrapper(),
+              "debug type mismatch without a DIExpr");
     }
 
     auto *debugScope = inst->getDebugScope();