diff --git a/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp b/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp
--- a/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp
@@ -78,10 +78,10 @@
     const char *const FuncPtr_name("__FuncPtr");
 
     m_block_struct_type = clang_ast_context->CreateStructForIdentifier(
-        ConstString(), {{isa_name, isa_type},
-                        {flags_name, flags_type},
-                        {reserved_name, reserved_type},
-                        {FuncPtr_name, function_pointer_type}});
+        llvm::StringRef(), {{isa_name, isa_type},
+                            {flags_name, flags_type},
+                            {reserved_name, reserved_type},
+                            {FuncPtr_name, function_pointer_type}});
   }
 
   ~BlockPointerSyntheticFrontEnd() override = default;
diff --git a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
--- a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
@@ -338,7 +338,7 @@
         //        +-----------------------------+
         //
         CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
-            ConstString(),
+            llvm::StringRef(),
             {{"ptr0",
               ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
              {"ptr1",
@@ -503,7 +503,7 @@
     //         +-----------------------------+
     //
     CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
-        ConstString(),
+        llvm::StringRef(),
         {{"__next_",
           ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
          {"__hash_", ast_ctx->GetBasicType(lldb::eBasicTypeUnsignedLongLong)},
diff --git a/lldb/source/Plugins/Language/CPlusPlus/LibCxxMap.cpp b/lldb/source/Plugins/Language/CPlusPlus/LibCxxMap.cpp
--- a/lldb/source/Plugins/Language/CPlusPlus/LibCxxMap.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/LibCxxMap.cpp
@@ -291,7 +291,7 @@
     if (!ast_ctx)
       return;
     CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
-        ConstString(),
+        llvm::StringRef(),
         {{"ptr0", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
          {"ptr1", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
          {"ptr2", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
diff --git a/lldb/source/Plugins/Platform/FreeBSD/PlatformFreeBSD.cpp b/lldb/source/Plugins/Platform/FreeBSD/PlatformFreeBSD.cpp
--- a/lldb/source/Plugins/Platform/FreeBSD/PlatformFreeBSD.cpp
+++ b/lldb/source/Plugins/Platform/FreeBSD/PlatformFreeBSD.cpp
@@ -244,7 +244,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_fault",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_trapno", int_type},
                                      }),
@@ -252,7 +252,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_timer",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_timerid", int_type},
                                          {"_overrun", int_type},
@@ -261,7 +261,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_mesgq",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_mqd", int_type},
                                      }),
@@ -269,7 +269,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_poll",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_band", long_type},
                                      }),
diff --git a/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp b/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp
--- a/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp
+++ b/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp
@@ -360,13 +360,14 @@
       nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "",
       clang::TTK_Union, lldb::eLanguageTypeC);
   ast->StartTagDeclarationDefinition(sigfault_bounds_type);
-  ast->AddFieldToRecordType(sigfault_bounds_type, "_addr_bnd",
-      ast->CreateStructForIdentifier(ConstString(),
+  ast->AddFieldToRecordType(
+      sigfault_bounds_type, "_addr_bnd",
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_lower", voidp_type},
                                          {"_upper", voidp_type},
                                      }),
-                            lldb::eAccessPublic, 0);
+      lldb::eAccessPublic, 0);
   ast->AddFieldToRecordType(sigfault_bounds_type, "_pkey", uint_type,
                             lldb::eAccessPublic, 0);
   ast->CompleteTagDeclarationDefinition(sigfault_bounds_type);
@@ -404,7 +405,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_kill",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"si_pid", pid_type},
                                          {"si_uid", uid_type},
@@ -413,7 +414,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_timer",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"si_tid", int_type},
                                          {"si_overrun", int_type},
@@ -423,7 +424,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_rt",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"si_pid", pid_type},
                                          {"si_uid", uid_type},
@@ -433,7 +434,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_sigchld",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"si_pid", pid_type},
                                          {"si_uid", uid_type},
@@ -445,7 +446,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_sigfault",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"si_addr", voidp_type},
                                          {"si_addr_lsb", short_type},
@@ -455,7 +456,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_sigpoll",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"si_band", band_type},
                                          {"si_fd", int_type},
@@ -465,7 +466,7 @@
   // NB: SIGSYS is not present on ia64 but we don't seem to support that
   ast->AddFieldToRecordType(
       union_type, "_sigsys",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_call_addr", voidp_type},
                                          {"_syscall", int_type},
diff --git a/lldb/source/Plugins/Platform/NetBSD/PlatformNetBSD.cpp b/lldb/source/Plugins/Platform/NetBSD/PlatformNetBSD.cpp
--- a/lldb/source/Plugins/Platform/NetBSD/PlatformNetBSD.cpp
+++ b/lldb/source/Plugins/Platform/NetBSD/PlatformNetBSD.cpp
@@ -277,7 +277,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_rt",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_pid", pid_type},
                                          {"_uid", uid_type},
@@ -287,7 +287,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_child",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_pid", pid_type},
                                          {"_uid", uid_type},
@@ -299,7 +299,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_fault",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_addr", voidp_type},
                                          {"_trap", int_type},
@@ -310,7 +310,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_poll",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_band", long_type},
                                          {"_fd", int_type},
@@ -319,7 +319,7 @@
 
   ast->AddFieldToRecordType(union_type, "_syscall",
                             ast->CreateStructForIdentifier(
-                                ConstString(),
+                                llvm::StringRef(),
                                 {
                                     {"_sysnum", int_type},
                                     {"_retval", int_type.GetArrayType(2)},
@@ -330,7 +330,7 @@
 
   ast->AddFieldToRecordType(
       union_type, "_ptrace_state",
-      ast->CreateStructForIdentifier(ConstString(),
+      ast->CreateStructForIdentifier(llvm::StringRef(),
                                      {
                                          {"_pe_report_event", int_type},
                                          {"_option", ptrace_option_type},
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
--- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
+++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
@@ -280,13 +280,13 @@
   }
 
   CompilerType CreateStructForIdentifier(
-      ConstString type_name,
+      llvm::StringRef type_name,
       const std::initializer_list<std::pair<const char *, CompilerType>>
           &type_fields,
       bool packed = false);
 
   CompilerType GetOrCreateStructForIdentifier(
-      ConstString type_name,
+      llvm::StringRef type_name,
       const std::initializer_list<std::pair<const char *, CompilerType>>
           &type_fields,
       bool packed = false);
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
--- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
+++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -2308,12 +2308,12 @@
 }
 
 CompilerType TypeSystemClang::CreateStructForIdentifier(
-    ConstString type_name,
+    llvm::StringRef type_name,
     const std::initializer_list<std::pair<const char *, CompilerType>>
         &type_fields,
     bool packed) {
   CompilerType type;
-  if (!type_name.IsEmpty() &&
+  if (!type_name.empty() &&
       (type = GetTypeForIdentifier<clang::CXXRecordDecl>(type_name))
           .IsValid()) {
     lldbassert(0 && "Trying to create a type for an existing name");
@@ -2321,8 +2321,7 @@
   }
 
   type = CreateRecordType(nullptr, OptionalClangModuleID(), lldb::eAccessPublic,
-                          type_name.GetCString(), clang::TTK_Struct,
-                          lldb::eLanguageTypeC);
+                          type_name, clang::TTK_Struct, lldb::eLanguageTypeC);
   StartTagDeclarationDefinition(type);
   for (const auto &field : type_fields)
     AddFieldToRecordType(type, field.first, field.second, lldb::eAccessPublic,
@@ -2334,7 +2333,7 @@
 }
 
 CompilerType TypeSystemClang::GetOrCreateStructForIdentifier(
-    ConstString type_name,
+    llvm::StringRef type_name,
     const std::initializer_list<std::pair<const char *, CompilerType>>
         &type_fields,
     bool packed) {