diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -153,7 +153,7 @@
   void setTag(unsigned Tag) { SubclassData16 = Tag; }
 
 public:
-  unsigned getTag() const { return SubclassData16; }
+  dwarf::Tag getTag() const { return (dwarf::Tag)SubclassData16; }
 
   /// Debug info flags.
   ///
@@ -262,7 +262,7 @@
   /// Return a (temporary) clone of this.
   TempGenericDINode clone() const { return cloneImpl(); }
 
-  unsigned getTag() const { return SubclassData16; }
+  dwarf::Tag getTag() const { return (dwarf::Tag)SubclassData16; }
   StringRef getHeader() const { return getStringOperand(0); }
   MDString *getRawHeader() const { return getOperandAs<MDString>(0); }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -273,9 +273,9 @@
     return "<unnamed-tag>";
   case dwarf::DW_TAG_namespace:
     return "`anonymous namespace'";
+  default:
+    return StringRef();
   }
-
-  return StringRef();
 }
 
 const DISubprogram *CodeViewDebug::collectParentScopeNames(
@@ -1487,6 +1487,9 @@
       case dwarf::DW_TAG_class_type:
       case dwarf::DW_TAG_union_type:
         return false;
+      default:
+          // do nothing.
+          ;
       }
     }
   }
@@ -2032,10 +2035,13 @@
 
 static TypeRecordKind getRecordKind(const DICompositeType *Ty) {
   switch (Ty->getTag()) {
-  case dwarf::DW_TAG_class_type:     return TypeRecordKind::Class;
-  case dwarf::DW_TAG_structure_type: return TypeRecordKind::Struct;
+  case dwarf::DW_TAG_class_type:
+    return TypeRecordKind::Class;
+  case dwarf::DW_TAG_structure_type:
+    return TypeRecordKind::Struct;
+  default:
+    llvm_unreachable("unexpected tag");
   }
-  llvm_unreachable("unexpected tag");
 }
 
 /// Return ClassOptions that should be present on both the forward declaration
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -257,7 +257,7 @@
 
   /// Create a DIE with the given Tag, add the DIE to its parent, and
   /// call insertDIE if MD is not null.
-  DIE &createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N = nullptr);
+  DIE &createAndAddDIE(dwarf::Tag Tag, DIE &Parent, const DINode *N = nullptr);
 
   bool useSegmentedStringOffsetsTable() const {
     return DD->useSegmentedStringOffsetsTable();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -385,8 +385,8 @@
                Entry);
 }
 
-DIE &DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N) {
-  DIE &Die = Parent.addChild(DIE::get(DIEValueAllocator, (dwarf::Tag)Tag));
+DIE &DwarfUnit::createAndAddDIE(dwarf::Tag Tag, DIE &Parent, const DINode *N) {
+  DIE &Die = Parent.addChild(DIE::get(DIEValueAllocator, Tag));
   if (N)
     insertDIE(N, &Die);
   return Die;