Index: include/lldb/Host/common/NativeRegisterContext.h
===================================================================
--- include/lldb/Host/common/NativeRegisterContext.h
+++ include/lldb/Host/common/NativeRegisterContext.h
@@ -27,8 +27,7 @@
   //------------------------------------------------------------------
   // Constructors and Destructors
   //------------------------------------------------------------------
-  NativeRegisterContext(NativeThreadProtocol &thread,
-                        uint32_t concrete_frame_idx);
+  NativeRegisterContext(NativeThreadProtocol &thread);
 
   virtual ~NativeRegisterContext();
 
@@ -184,8 +183,6 @@
   //------------------------------------------------------------------
   NativeThreadProtocol
       &m_thread; // The thread that this register context belongs to.
-  uint32_t m_concrete_frame_idx; // The concrete frame index for this register
-                                 // context
   // uint32_t m_stop_id;             // The stop ID that any data in this
   // context is valid for
 
Index: include/lldb/Host/common/NativeThreadProtocol.h
===================================================================
--- include/lldb/Host/common/NativeThreadProtocol.h
+++ include/lldb/Host/common/NativeThreadProtocol.h
@@ -30,7 +30,7 @@
 
   virtual lldb::StateType GetState() = 0;
 
-  virtual NativeRegisterContextSP GetRegisterContext() = 0;
+  virtual NativeRegisterContext &GetRegisterContext() = 0;
 
   virtual Status ReadRegister(uint32_t reg, RegisterValue &reg_value);
 
Index: include/lldb/lldb-private-forward.h
===================================================================
--- include/lldb/lldb-private-forward.h
+++ include/lldb/lldb-private-forward.h
@@ -30,8 +30,6 @@
 // SP/WP decls.
 // ---------------------------------------------------------------
 typedef std::shared_ptr<NativeBreakpoint> NativeBreakpointSP;
-typedef std::shared_ptr<lldb_private::NativeRegisterContext>
-    NativeRegisterContextSP;
 }
 
 #endif // #if defined(__cplusplus)
Index: source/Host/common/NativeProcessProtocol.cpp
===================================================================
--- source/Host/common/NativeProcessProtocol.cpp
+++ source/Host/common/NativeProcessProtocol.cpp
@@ -131,16 +131,9 @@
     return llvm::None;
   }
 
-  NativeRegisterContextSP reg_ctx_sp(thread->GetRegisterContext());
-  if (!reg_ctx_sp) {
-    LLDB_LOG(
-        log,
-        "failed to get a RegisterContextNativeProcess from the first thread!");
-    return llvm::None;
-  }
-
-  return std::make_pair(reg_ctx_sp->NumSupportedHardwareBreakpoints(),
-                        reg_ctx_sp->NumSupportedHardwareWatchpoints());
+  NativeRegisterContext &reg_ctx = thread->GetRegisterContext();
+  return std::make_pair(reg_ctx.NumSupportedHardwareBreakpoints(),
+                        reg_ctx.NumSupportedHardwareWatchpoints());
 }
 
 Status NativeProcessProtocol::SetWatchpoint(lldb::addr_t addr, size_t size,
Index: source/Host/common/NativeRegisterContext.cpp
===================================================================
--- source/Host/common/NativeRegisterContext.cpp
+++ source/Host/common/NativeRegisterContext.cpp
@@ -19,9 +19,8 @@
 using namespace lldb;
 using namespace lldb_private;
 
-NativeRegisterContext::NativeRegisterContext(NativeThreadProtocol &thread,
-                                             uint32_t concrete_frame_idx)
-    : m_thread(thread), m_concrete_frame_idx(concrete_frame_idx) {}
+NativeRegisterContext::NativeRegisterContext(NativeThreadProtocol &thread)
+    : m_thread(thread) {}
 
 //----------------------------------------------------------------------
 // Destructor
Index: source/Host/common/NativeThreadProtocol.cpp
===================================================================
--- source/Host/common/NativeThreadProtocol.cpp
+++ source/Host/common/NativeThreadProtocol.cpp
@@ -22,43 +22,33 @@
 
 Status NativeThreadProtocol::ReadRegister(uint32_t reg,
                                           RegisterValue &reg_value) {
-  NativeRegisterContextSP register_context_sp = GetRegisterContext();
-  if (!register_context_sp)
-    return Status("no register context");
+  NativeRegisterContext &register_context = GetRegisterContext();
 
   const RegisterInfo *const reg_info =
-      register_context_sp->GetRegisterInfoAtIndex(reg);
+      register_context.GetRegisterInfoAtIndex(reg);
   if (!reg_info)
     return Status("no register info for reg num %" PRIu32, reg);
 
-  return register_context_sp->ReadRegister(reg_info, reg_value);
+  return register_context.ReadRegister(reg_info, reg_value);
   ;
 }
 
 Status NativeThreadProtocol::WriteRegister(uint32_t reg,
                                            const RegisterValue &reg_value) {
-  NativeRegisterContextSP register_context_sp = GetRegisterContext();
-  if (!register_context_sp)
-    return Status("no register context");
+  NativeRegisterContext& register_context = GetRegisterContext();
 
   const RegisterInfo *const reg_info =
-      register_context_sp->GetRegisterInfoAtIndex(reg);
+      register_context.GetRegisterInfoAtIndex(reg);
   if (!reg_info)
     return Status("no register info for reg num %" PRIu32, reg);
 
-  return register_context_sp->WriteRegister(reg_info, reg_value);
+  return register_context.WriteRegister(reg_info, reg_value);
 }
 
 Status NativeThreadProtocol::SaveAllRegisters(lldb::DataBufferSP &data_sp) {
-  NativeRegisterContextSP register_context_sp = GetRegisterContext();
-  if (!register_context_sp)
-    return Status("no register context");
-  return register_context_sp->WriteAllRegisterValues(data_sp);
+  return GetRegisterContext().WriteAllRegisterValues(data_sp);
 }
 
 Status NativeThreadProtocol::RestoreAllRegisters(lldb::DataBufferSP &data_sp) {
-  NativeRegisterContextSP register_context_sp = GetRegisterContext();
-  if (!register_context_sp)
-    return Status("no register context");
-  return register_context_sp->ReadAllRegisterValues(data_sp);
+  return GetRegisterContext().ReadAllRegisterValues(data_sp);
 }
Index: source/Plugins/Process/Linux/NativeProcessLinux.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -702,7 +702,7 @@
   {
     // If a watchpoint was hit, report it
     uint32_t wp_index;
-    Status error = thread.GetRegisterContext()->GetWatchpointHitIndex(
+    Status error = thread.GetRegisterContext().GetWatchpointHitIndex(
         wp_index, (uintptr_t)info.si_addr);
     if (error.Fail())
       LLDB_LOG(log,
@@ -716,7 +716,7 @@
 
     // If a breakpoint was hit, report it
     uint32_t bp_index;
-    error = thread.GetRegisterContext()->GetHardwareBreakHitIndex(
+    error = thread.GetRegisterContext().GetHardwareBreakHitIndex(
         bp_index, (uintptr_t)info.si_addr);
     if (error.Fail())
       LLDB_LOG(log, "received error while checking for hardware "
@@ -739,7 +739,7 @@
     {
       // If a watchpoint was hit, report it
       uint32_t wp_index;
-      Status error = thread.GetRegisterContext()->GetWatchpointHitIndex(
+      Status error = thread.GetRegisterContext().GetWatchpointHitIndex(
           wp_index, LLDB_INVALID_ADDRESS);
       if (error.Fail())
         LLDB_LOG(log,
@@ -910,13 +910,13 @@
 namespace {
 
 struct EmulatorBaton {
-  NativeProcessLinux *m_process;
-  NativeRegisterContext *m_reg_context;
+  NativeProcessLinux &m_process;
+  NativeRegisterContext &m_reg_context;
 
   // eRegisterKindDWARF -> RegsiterValue
   std::unordered_map<uint32_t, RegisterValue> m_register_values;
 
-  EmulatorBaton(NativeProcessLinux *process, NativeRegisterContext *reg_context)
+  EmulatorBaton(NativeProcessLinux &process, NativeRegisterContext &reg_context)
       : m_process(process), m_reg_context(reg_context) {}
 };
 
@@ -928,7 +928,7 @@
   EmulatorBaton *emulator_baton = static_cast<EmulatorBaton *>(baton);
 
   size_t bytes_read;
-  emulator_baton->m_process->ReadMemory(addr, dst, length, bytes_read);
+  emulator_baton->m_process.ReadMemory(addr, dst, length, bytes_read);
   return bytes_read;
 }
 
@@ -948,11 +948,11 @@
   // the generic register numbers). Get the full register info from the
   // register context based on the dwarf register numbers.
   const RegisterInfo *full_reg_info =
-      emulator_baton->m_reg_context->GetRegisterInfo(
+      emulator_baton->m_reg_context.GetRegisterInfo(
           eRegisterKindDWARF, reg_info->kinds[eRegisterKindDWARF]);
 
   Status error =
-      emulator_baton->m_reg_context->ReadRegister(full_reg_info, reg_value);
+      emulator_baton->m_reg_context.ReadRegister(full_reg_info, reg_value);
   if (error.Success())
     return true;
 
@@ -976,17 +976,17 @@
   return length;
 }
 
-static lldb::addr_t ReadFlags(NativeRegisterContext *regsiter_context) {
-  const RegisterInfo *flags_info = regsiter_context->GetRegisterInfo(
+static lldb::addr_t ReadFlags(NativeRegisterContext &regsiter_context) {
+  const RegisterInfo *flags_info = regsiter_context.GetRegisterInfo(
       eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FLAGS);
-  return regsiter_context->ReadRegisterAsUnsigned(flags_info,
-                                                  LLDB_INVALID_ADDRESS);
+  return regsiter_context.ReadRegisterAsUnsigned(flags_info,
+                                                 LLDB_INVALID_ADDRESS);
 }
 
 Status
 NativeProcessLinux::SetupSoftwareSingleStepping(NativeThreadLinux &thread) {
   Status error;
-  NativeRegisterContextSP register_context_sp = thread.GetRegisterContext();
+  NativeRegisterContext& register_context = thread.GetRegisterContext();
 
   std::unique_ptr<EmulateInstruction> emulator_ap(
       EmulateInstruction::FindPlugin(m_arch, eInstructionTypePCModifying,
@@ -995,7 +995,7 @@
   if (emulator_ap == nullptr)
     return Status("Instruction emulator not found!");
 
-  EmulatorBaton baton(this, register_context_sp.get());
+  EmulatorBaton baton(*this, register_context);
   emulator_ap->SetBaton(&baton);
   emulator_ap->SetReadMemCallback(&ReadMemoryCallback);
   emulator_ap->SetReadRegCallback(&ReadRegisterCallback);
@@ -1008,9 +1008,9 @@
   bool emulation_result =
       emulator_ap->EvaluateInstruction(eEmulateInstructionOptionAutoAdvancePC);
 
-  const RegisterInfo *reg_info_pc = register_context_sp->GetRegisterInfo(
+  const RegisterInfo *reg_info_pc = register_context.GetRegisterInfo(
       eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
-  const RegisterInfo *reg_info_flags = register_context_sp->GetRegisterInfo(
+  const RegisterInfo *reg_info_flags = register_context.GetRegisterInfo(
       eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FLAGS);
 
   auto pc_it =
@@ -1028,15 +1028,14 @@
     if (flags_it != baton.m_register_values.end())
       next_flags = flags_it->second.GetAsUInt64();
     else
-      next_flags = ReadFlags(register_context_sp.get());
+      next_flags = ReadFlags(register_context);
   } else if (pc_it == baton.m_register_values.end()) {
     // Emulate instruction failed and it haven't changed PC. Advance PC
     // with the size of the current opcode because the emulation of all
     // PC modifying instruction should be successful. The failure most
     // likely caused by a not supported instruction which don't modify PC.
-    next_pc =
-        register_context_sp->GetPC() + emulator_ap->GetOpcode().GetByteSize();
-    next_flags = ReadFlags(register_context_sp.get());
+    next_pc = register_context.GetPC() + emulator_ap->GetOpcode().GetByteSize();
+    next_flags = ReadFlags(register_context);
   } else {
     // The instruction emulation failed after it modified the PC. It is an
     // unknown error where we can't continue because the next instruction is
@@ -2012,12 +2011,7 @@
 
   // Find out the size of a breakpoint (might depend on where we are in the
   // code).
-  NativeRegisterContextSP context_sp = thread.GetRegisterContext();
-  if (!context_sp) {
-    error.SetErrorString("cannot get a NativeRegisterContext for the thread");
-    LLDB_LOG(log, "failed: {0}", error);
-    return error;
-  }
+  NativeRegisterContext &context = thread.GetRegisterContext();
 
   uint32_t breakpoint_size = 0;
   error = GetSoftwareBreakpointPCOffset(breakpoint_size);
@@ -2029,8 +2023,7 @@
 
   // First try probing for a breakpoint at a software breakpoint location: PC -
   // breakpoint size.
-  const lldb::addr_t initial_pc_addr =
-      context_sp->GetPCfromBreakpointLocation();
+  const lldb::addr_t initial_pc_addr = context.GetPCfromBreakpointLocation();
   lldb::addr_t breakpoint_addr = initial_pc_addr;
   if (breakpoint_size > 0) {
     // Do not allow breakpoint probe to wrap around.
@@ -2077,7 +2070,7 @@
   LLDB_LOG(log, "pid {0} tid {1}: changing PC from {2:x} to {3:x}", GetID(),
            thread.GetID(), initial_pc_addr, breakpoint_addr);
 
-  error = context_sp->SetPC(breakpoint_addr);
+  error = context.SetPC(breakpoint_addr);
   if (error.Fail()) {
     LLDB_LOG(log, "pid {0} tid {1}: failed to set PC: {2}", GetID(),
              thread.GetID(), error);
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux.h
@@ -10,10 +10,8 @@
 #ifndef lldb_NativeRegisterContextLinux_h
 #define lldb_NativeRegisterContextLinux_h
 
-#include "lldb/Host/common/NativeThreadProtocol.h"
-
-#include "Plugins/Process/Linux/NativeProcessLinux.h"
 #include "Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h"
+#include "lldb/Host/common/NativeThreadProtocol.h"
 
 namespace lldb_private {
 namespace process_linux {
@@ -21,20 +19,15 @@
 class NativeRegisterContextLinux : public NativeRegisterContextRegisterInfo {
 public:
   NativeRegisterContextLinux(NativeThreadProtocol &native_thread,
-                             uint32_t concrete_frame_idx,
                              RegisterInfoInterface *reg_info_interface_p);
 
   // This function is implemented in the NativeRegisterContextLinux_* subclasses
-  // to create a new
-  // instance of the host specific NativeRegisterContextLinux. The
-  // implementations can't collide
-  // as only one NativeRegisterContextLinux_* variant should be compiled into
-  // the final
-  // executable.
-  static NativeRegisterContextLinux *
+  // to create a new instance of the host specific NativeRegisterContextLinux.
+  // The implementations can't collide as only one NativeRegisterContextLinux_*
+  // variant should be compiled into the final executable.
+  static std::unique_ptr<NativeRegisterContextLinux>
   CreateHostNativeRegisterContextLinux(const ArchSpec &target_arch,
-                                       NativeThreadProtocol &native_thread,
-                                       uint32_t concrete_frame_idx);
+                                       NativeThreadProtocol &native_thread);
 
 protected:
   lldb::ByteOrder GetByteOrder() const;
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux.cpp
@@ -14,16 +14,16 @@
 #include "lldb/Host/common/NativeThreadProtocol.h"
 #include "lldb/Host/linux/Ptrace.h"
 
+#include "Plugins/Process/Linux/NativeProcessLinux.h"
 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
 
 using namespace lldb_private;
 using namespace lldb_private::process_linux;
 
 NativeRegisterContextLinux::NativeRegisterContextLinux(
-    NativeThreadProtocol &native_thread, uint32_t concrete_frame_idx,
+    NativeThreadProtocol &native_thread,
     RegisterInfoInterface *reg_info_interface_p)
-    : NativeRegisterContextRegisterInfo(native_thread, concrete_frame_idx,
-                                        reg_info_interface_p) {}
+    : NativeRegisterContextRegisterInfo(native_thread, reg_info_interface_p) {}
 
 lldb::ByteOrder NativeRegisterContextLinux::GetByteOrder() const {
   return m_thread.GetProcess().GetByteOrder();
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.h
@@ -23,8 +23,7 @@
 class NativeRegisterContextLinux_arm : public NativeRegisterContextLinux {
 public:
   NativeRegisterContextLinux_arm(const ArchSpec &target_arch,
-                                 NativeThreadProtocol &native_thread,
-                                 uint32_t concrete_frame_idx);
+                                 NativeThreadProtocol &native_thread);
 
   uint32_t GetRegisterSetCount() const override;
 
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.cpp
@@ -11,15 +11,15 @@
 
 #include "NativeRegisterContextLinux_arm.h"
 
+#include "Plugins/Process/Linux/NativeProcessLinux.h"
+#include "Plugins/Process/Linux/Procfs.h"
+#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
+#include "Plugins/Process/Utility/RegisterInfoPOSIX_arm.h"
 #include "lldb/Core/RegisterValue.h"
 #include "lldb/Utility/DataBufferHeap.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Status.h"
 
-#include "Plugins/Process/Linux/Procfs.h"
-#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
-#include "Plugins/Process/Utility/RegisterInfoPOSIX_arm.h"
-
 #include <elf.h>
 #include <sys/socket.h>
 
@@ -95,20 +95,18 @@
 
 #if defined(__arm__)
 
-NativeRegisterContextLinux *
+std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
-  return new NativeRegisterContextLinux_arm(target_arch, native_thread,
-                                            concrete_frame_idx);
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
+  return llvm::make_unique<NativeRegisterContextLinux_arm>(target_arch,
+                                                           native_thread);
 }
 
 #endif // defined(__arm__)
 
 NativeRegisterContextLinux_arm::NativeRegisterContextLinux_arm(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextLinux(native_thread,
                                  new RegisterInfoPOSIX_arm(target_arch)) {
   switch (target_arch.GetMachine()) {
   case llvm::Triple::arm:
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
@@ -23,8 +23,7 @@
 class NativeRegisterContextLinux_arm64 : public NativeRegisterContextLinux {
 public:
   NativeRegisterContextLinux_arm64(const ArchSpec &target_arch,
-                                   NativeThreadProtocol &native_thread,
-                                   uint32_t concrete_frame_idx);
+                                   NativeThreadProtocol &native_thread);
 
   uint32_t GetRegisterSetCount() const override;
 
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
@@ -112,26 +112,24 @@
     {"Floating Point Registers", "fpu", k_num_fpr_registers_arm64,
      g_fpu_regnums_arm64}};
 
-NativeRegisterContextLinux *
+std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
   switch (target_arch.GetMachine()) {
   case llvm::Triple::arm:
-    return new NativeRegisterContextLinux_arm(target_arch, native_thread,
-                                              concrete_frame_idx);
+    return llvm::make_unique<NativeRegisterContextLinux_arm>(target_arch,
+                                                             native_thread);
   case llvm::Triple::aarch64:
-    return new NativeRegisterContextLinux_arm64(target_arch, native_thread,
-                                                concrete_frame_idx);
+    return llvm::make_unique<NativeRegisterContextLinux_arm64>(target_arch,
+                                                               native_thread);
   default:
     llvm_unreachable("have no register context for architecture");
   }
 }
 
 NativeRegisterContextLinux_arm64::NativeRegisterContextLinux_arm64(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextLinux(native_thread,
                                  new RegisterInfoPOSIX_arm64(target_arch)) {
   switch (target_arch.GetMachine()) {
   case llvm::Triple::aarch64:
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h
@@ -26,8 +26,7 @@
 class NativeRegisterContextLinux_mips64 : public NativeRegisterContextLinux {
 public:
   NativeRegisterContextLinux_mips64(const ArchSpec &target_arch,
-                                    NativeThreadProtocol &native_thread,
-                                    uint32_t concrete_frame_idx);
+                                    NativeThreadProtocol &native_thread);
 
   uint32_t GetRegisterSetCount() const override;
 
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp
@@ -80,12 +80,11 @@
 using namespace lldb_private;
 using namespace lldb_private::process_linux;
 
-NativeRegisterContextLinux *
+std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
-  return new NativeRegisterContextLinux_mips64(target_arch, native_thread,
-                                               concrete_frame_idx);
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
+  return llvm::make_unique<NativeRegisterContextLinux_mips64>(target_arch,
+                                                              native_thread);
 }
 
 #define REG_CONTEXT_SIZE                                                       \
@@ -110,9 +109,8 @@
 }
 
 NativeRegisterContextLinux_mips64::NativeRegisterContextLinux_mips64(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextLinux(native_thread,
                                  CreateRegisterInfoInterface(target_arch)) {
   switch (target_arch.GetMachine()) {
   case llvm::Triple::mips:
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_ppc64le.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_ppc64le.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_ppc64le.h
@@ -30,8 +30,7 @@
 class NativeRegisterContextLinux_ppc64le : public NativeRegisterContextLinux {
 public:
   NativeRegisterContextLinux_ppc64le(const ArchSpec &target_arch,
-                                   NativeThreadProtocol &native_thread,
-                                   uint32_t concrete_frame_idx);
+                                     NativeThreadProtocol &native_thread);
 
   uint32_t GetRegisterSetCount() const override;
 
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_ppc64le.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_ppc64le.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_ppc64le.cpp
@@ -111,23 +111,21 @@
      g_vsx_regnums_ppc64le},
 };
 
-NativeRegisterContextLinux *
+std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
   switch (target_arch.GetMachine()) {
   case llvm::Triple::ppc64le:
-    return new NativeRegisterContextLinux_ppc64le(target_arch, native_thread,
-                                              concrete_frame_idx);
+    return llvm::make_unique<NativeRegisterContextLinux_ppc64le>(target_arch,
+                                                                 native_thread);
   default:
     llvm_unreachable("have no register context for architecture");
   }
 }
 
 NativeRegisterContextLinux_ppc64le::NativeRegisterContextLinux_ppc64le(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextLinux(native_thread,
                                  new RegisterInfoPOSIX_ppc64le(target_arch)) {
   if (target_arch.GetMachine() != llvm::Triple::ppc64le) {
     llvm_unreachable("Unhandled target architecture.");
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_s390x.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_s390x.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_s390x.h
@@ -24,8 +24,7 @@
 class NativeRegisterContextLinux_s390x : public NativeRegisterContextLinux {
 public:
   NativeRegisterContextLinux_s390x(const ArchSpec &target_arch,
-                                   NativeThreadProtocol &native_thread,
-                                   uint32_t concrete_frame_idx);
+                                   NativeThreadProtocol &native_thread);
 
   uint32_t GetRegisterSetCount() const override;
 
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_s390x.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_s390x.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_s390x.cpp
@@ -97,12 +97,11 @@
 #define NT_S390_LAST_BREAK 0x306  /* s390 breaking event address */
 #define NT_S390_SYSTEM_CALL 0x307 /* s390 system call restart data */
 
-NativeRegisterContextLinux *
+std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
-  return new NativeRegisterContextLinux_s390x(target_arch, native_thread,
-                                              concrete_frame_idx);
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
+  return llvm::make_unique<NativeRegisterContextLinux_s390x>(target_arch,
+                                                             native_thread);
 }
 
 // ----------------------------------------------------------------------------
@@ -117,9 +116,8 @@
 }
 
 NativeRegisterContextLinux_s390x::NativeRegisterContextLinux_s390x(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextLinux(native_thread,
                                  CreateRegisterInfoInterface(target_arch)) {
   // Set up data about ranges of valid registers.
   switch (target_arch.GetMachine()) {
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h
@@ -24,8 +24,7 @@
 class NativeRegisterContextLinux_x86_64 : public NativeRegisterContextLinux {
 public:
   NativeRegisterContextLinux_x86_64(const ArchSpec &target_arch,
-                                    NativeThreadProtocol &native_thread,
-                                    uint32_t concrete_frame_idx);
+                                    NativeThreadProtocol &native_thread);
 
   uint32_t GetRegisterSetCount() const override;
 
Index: source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
+++ source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
@@ -243,12 +243,11 @@
 #define mask_XSTATE_BNDCFG (1ULL << 4)
 #define mask_XSTATE_MPX (mask_XSTATE_BNDREGS | mask_XSTATE_BNDCFG)
 
-NativeRegisterContextLinux *
+std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
-  return new NativeRegisterContextLinux_x86_64(target_arch, native_thread,
-                                               concrete_frame_idx);
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
+  return std::unique_ptr<NativeRegisterContextLinux>(
+      new NativeRegisterContextLinux_x86_64(target_arch, native_thread));
 }
 
 // ----------------------------------------------------------------------------
@@ -270,9 +269,8 @@
 }
 
 NativeRegisterContextLinux_x86_64::NativeRegisterContextLinux_x86_64(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextLinux(native_thread,
                                  CreateRegisterInfoInterface(target_arch)),
       m_xstate_type(XStateType::Invalid), m_fpr(), m_iovec(), m_ymm_set(),
       m_mpx_set(), m_reg_info(), m_gpr_x86_64() {
Index: source/Plugins/Process/Linux/NativeThreadLinux.h
===================================================================
--- source/Plugins/Process/Linux/NativeThreadLinux.h
+++ source/Plugins/Process/Linux/NativeThreadLinux.h
@@ -10,7 +10,8 @@
 #ifndef liblldb_NativeThreadLinux_H_
 #define liblldb_NativeThreadLinux_H_
 
-#include "SingleStepCheck.h"
+#include "Plugins/Process/Linux/NativeRegisterContextLinux.h"
+#include "Plugins/Process/Linux/SingleStepCheck.h"
 #include "lldb/Host/common/NativeThreadProtocol.h"
 #include "lldb/lldb-private-forward.h"
 
@@ -40,7 +41,9 @@
   bool GetStopReason(ThreadStopInfo &stop_info,
                      std::string &description) override;
 
-  NativeRegisterContextSP GetRegisterContext() override;
+  NativeRegisterContextLinux &GetRegisterContext() override {
+    return *m_reg_context_up;
+  }
 
   Status SetWatchpoint(lldb::addr_t addr, size_t size, uint32_t watch_flags,
                        bool hardware) override;
@@ -103,7 +106,7 @@
   // ---------------------------------------------------------------------
   lldb::StateType m_state;
   ThreadStopInfo m_stop_info;
-  NativeRegisterContextSP m_reg_context_sp;
+  std::unique_ptr<NativeRegisterContextLinux> m_reg_context_up;
   std::string m_stop_description;
   using WatchpointIndexMap = std::map<lldb::addr_t, uint32_t>;
   WatchpointIndexMap m_watchpoint_index_map;
Index: source/Plugins/Process/Linux/NativeThreadLinux.cpp
===================================================================
--- source/Plugins/Process/Linux/NativeThreadLinux.cpp
+++ source/Plugins/Process/Linux/NativeThreadLinux.cpp
@@ -88,7 +88,11 @@
 NativeThreadLinux::NativeThreadLinux(NativeProcessLinux &process,
                                      lldb::tid_t tid)
     : NativeThreadProtocol(process, tid), m_state(StateType::eStateInvalid),
-      m_stop_info(), m_reg_context_sp(), m_stop_description() {}
+      m_stop_info(),
+      m_reg_context_up(
+          NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
+              process.GetArchitecture(), *this)),
+      m_stop_description() {}
 
 std::string NativeThreadLinux::GetName() {
   NativeProcessLinux &process = GetProcess();
@@ -139,19 +143,6 @@
   llvm_unreachable("unhandled StateType!");
 }
 
-NativeRegisterContextSP NativeThreadLinux::GetRegisterContext() {
-  // Return the register context if we already created it.
-  if (m_reg_context_sp)
-    return m_reg_context_sp;
-
-  const uint32_t concrete_frame_idx = 0;
-  m_reg_context_sp.reset(
-      NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
-          m_process.GetArchitecture(), *this, concrete_frame_idx));
-
-  return m_reg_context_sp;
-}
-
 Status NativeThreadLinux::SetWatchpoint(lldb::addr_t addr, size_t size,
                                         uint32_t watch_flags, bool hardware) {
   if (!hardware)
@@ -161,8 +152,8 @@
   Status error = RemoveWatchpoint(addr);
   if (error.Fail())
     return error;
-  NativeRegisterContextSP reg_ctx = GetRegisterContext();
-  uint32_t wp_index = reg_ctx->SetHardwareWatchpoint(addr, size, watch_flags);
+  uint32_t wp_index =
+      m_reg_context_up->SetHardwareWatchpoint(addr, size, watch_flags);
   if (wp_index == LLDB_INVALID_INDEX32)
     return Status("Setting hardware watchpoint failed.");
   m_watchpoint_index_map.insert({addr, wp_index});
@@ -175,7 +166,7 @@
     return Status();
   uint32_t wp_index = wp->second;
   m_watchpoint_index_map.erase(wp);
-  if (GetRegisterContext()->ClearHardwareWatchpoint(wp_index))
+  if (m_reg_context_up->ClearHardwareWatchpoint(wp_index))
     return Status();
   return Status("Clearing hardware watchpoint failed.");
 }
@@ -189,8 +180,7 @@
   if (error.Fail())
     return error;
 
-  NativeRegisterContextSP reg_ctx = GetRegisterContext();
-  uint32_t bp_index = reg_ctx->SetHardwareBreakpoint(addr, size);
+  uint32_t bp_index = m_reg_context_up->SetHardwareBreakpoint(addr, size);
 
   if (bp_index == LLDB_INVALID_INDEX32)
     return Status("Setting hardware breakpoint failed.");
@@ -205,7 +195,7 @@
     return Status();
 
   uint32_t bp_index = bp->second;
-  if (GetRegisterContext()->ClearHardwareBreakpoint(bp_index)) {
+  if (m_reg_context_up->ClearHardwareBreakpoint(bp_index)) {
     m_hw_break_index_map.erase(bp);
     return Status();
   }
@@ -227,7 +217,7 @@
     NativeProcessLinux &process = GetProcess();
 
     const auto &watchpoint_map = process.GetWatchpointMap();
-    GetRegisterContext()->ClearAllHardwareWatchpoints();
+    m_reg_context_up->ClearAllHardwareWatchpoints();
     for (const auto &pair : watchpoint_map) {
       const auto &wp = pair.second;
       SetWatchpoint(wp.m_addr, wp.m_size, wp.m_watch_flags, wp.m_hardware);
@@ -239,7 +229,7 @@
     NativeProcessLinux &process = GetProcess();
 
     const auto &hw_breakpoint_map = process.GetHardwareBreakpointMap();
-    GetRegisterContext()->ClearAllHardwareBreakpoints();
+    m_reg_context_up->ClearAllHardwareBreakpoints();
     for (const auto &pair : hw_breakpoint_map) {
       const auto &bp = pair.second;
       SetHardwareBreakpoint(bp.m_addr, bp.m_size);
@@ -361,7 +351,7 @@
   lldbassert(wp_index != LLDB_INVALID_INDEX32 && "wp_index cannot be invalid");
 
   std::ostringstream ostr;
-  ostr << GetRegisterContext()->GetWatchpointAddress(wp_index) << " ";
+  ostr << m_reg_context_up->GetWatchpointAddress(wp_index) << " ";
   ostr << wp_index;
 
   /*
@@ -375,7 +365,7 @@
    * stop-info
    * packet.
   */
-  ostr << " " << GetRegisterContext()->GetWatchpointHitAddress(wp_index);
+  ostr << " " << m_reg_context_up->GetWatchpointHitAddress(wp_index);
 
   m_stop_description = ostr.str();
 
Index: source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
===================================================================
--- source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
+++ source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
@@ -249,7 +249,7 @@
     uint32_t wp_index;
     Status error = static_cast<NativeThreadNetBSD &>(*m_threads[info.psi_lwpid])
                        .GetRegisterContext()
-                       ->GetWatchpointHitIndex(
+                       .GetWatchpointHitIndex(
                            wp_index, (uintptr_t)info.psi_siginfo.si_addr);
     if (error.Fail())
       LLDB_LOG(log,
@@ -268,7 +268,7 @@
     uint32_t bp_index;
     error = static_cast<NativeThreadNetBSD &>(*m_threads[info.psi_lwpid])
                 .GetRegisterContext()
-                ->GetHardwareBreakHitIndex(bp_index,
+                .GetHardwareBreakHitIndex(bp_index,
                                            (uintptr_t)info.psi_siginfo.si_addr);
     if (error.Fail())
       LLDB_LOG(log,
@@ -341,12 +341,7 @@
   Status error;
   // Find out the size of a breakpoint (might depend on where we are in the
   // code).
-  NativeRegisterContextSP context_sp = thread.GetRegisterContext();
-  if (!context_sp) {
-    error.SetErrorString("cannot get a NativeRegisterContext for the thread");
-    LLDB_LOG(log, "failed: {0}", error);
-    return error;
-  }
+  NativeRegisterContext& context = thread.GetRegisterContext();
   uint32_t breakpoint_size = 0;
   error = GetSoftwareBreakpointPCOffset(breakpoint_size);
   if (error.Fail()) {
@@ -357,7 +352,7 @@
   // First try probing for a breakpoint at a software breakpoint location: PC
   // - breakpoint size.
   const lldb::addr_t initial_pc_addr =
-      context_sp->GetPCfromBreakpointLocation();
+      context.GetPCfromBreakpointLocation();
   lldb::addr_t breakpoint_addr = initial_pc_addr;
   if (breakpoint_size > 0) {
     // Do not allow breakpoint probe to wrap around.
@@ -410,7 +405,7 @@
   // Change the program counter.
   LLDB_LOG(log, "pid {0} tid {1}: changing PC from {2:x} to {3:x}", GetID(),
            thread.GetID(), initial_pc_addr, breakpoint_addr);
-  error = context_sp->SetPC(breakpoint_addr);
+  error = context.SetPC(breakpoint_addr);
   if (error.Fail()) {
     LLDB_LOG(log, "pid {0} tid {1}: failed to set PC: {2}", GetID(),
              thread.GetID(), error);
Index: source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.h
===================================================================
--- source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.h
+++ source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.h
@@ -21,7 +21,6 @@
 class NativeRegisterContextNetBSD : public NativeRegisterContextRegisterInfo {
 public:
   NativeRegisterContextNetBSD(NativeThreadProtocol &native_thread,
-                              uint32_t concrete_frame_idx,
                               RegisterInfoInterface *reg_info_interface_p);
 
   // This function is implemented in the NativeRegisterContextNetBSD_*
@@ -31,8 +30,7 @@
   // executable.
   static NativeRegisterContextNetBSD *
   CreateHostNativeRegisterContextNetBSD(const ArchSpec &target_arch,
-                                        NativeThreadProtocol &native_thread,
-                                        uint32_t concrete_frame_idx);
+                                        NativeThreadProtocol &native_thread);
 
 protected:
   virtual Status ReadGPR();
Index: source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.cpp
===================================================================
--- source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.cpp
+++ source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.cpp
@@ -20,9 +20,9 @@
 // clang-format on
 
 NativeRegisterContextNetBSD::NativeRegisterContextNetBSD(
-    NativeThreadProtocol &native_thread, uint32_t concrete_frame_idx,
+    NativeThreadProtocol &native_thread,
     RegisterInfoInterface *reg_info_interface_p)
-    : NativeRegisterContextRegisterInfo(native_thread, concrete_frame_idx,
+    : NativeRegisterContextRegisterInfo(native_thread,
                                         reg_info_interface_p) {}
 
 Status NativeRegisterContextNetBSD::ReadGPR() {
Index: source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.h
===================================================================
--- source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.h
+++ source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.h
@@ -30,8 +30,7 @@
 class NativeRegisterContextNetBSD_x86_64 : public NativeRegisterContextNetBSD {
 public:
   NativeRegisterContextNetBSD_x86_64(const ArchSpec &target_arch,
-                                     NativeThreadProtocol &native_thread,
-                                     uint32_t concrete_frame_idx);
+                                     NativeThreadProtocol &native_thread);
   uint32_t GetRegisterSetCount() const override;
 
   const RegisterSet *GetRegisterSet(uint32_t set_index) const override;
Index: source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.cpp
===================================================================
--- source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.cpp
+++ source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.cpp
@@ -149,10 +149,8 @@
 
 NativeRegisterContextNetBSD *
 NativeRegisterContextNetBSD::CreateHostNativeRegisterContextNetBSD(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx) {
-  return new NativeRegisterContextNetBSD_x86_64(target_arch, native_thread,
-                                                concrete_frame_idx);
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
+  return new NativeRegisterContextNetBSD_x86_64(target_arch, native_thread);
 }
 
 // ----------------------------------------------------------------------------
@@ -169,9 +167,8 @@
 }
 
 NativeRegisterContextNetBSD_x86_64::NativeRegisterContextNetBSD_x86_64(
-    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
-    uint32_t concrete_frame_idx)
-    : NativeRegisterContextNetBSD(native_thread, concrete_frame_idx,
+    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
+    : NativeRegisterContextNetBSD(native_thread,
                                   CreateRegisterInfoInterface(target_arch)),
       m_gpr_x86_64(), m_fpr_x86_64(), m_dbr_x86_64() {}
 
Index: source/Plugins/Process/NetBSD/NativeThreadNetBSD.h
===================================================================
--- source/Plugins/Process/NetBSD/NativeThreadNetBSD.h
+++ source/Plugins/Process/NetBSD/NativeThreadNetBSD.h
@@ -37,7 +37,7 @@
   bool GetStopReason(ThreadStopInfo &stop_info,
                      std::string &description) override;
 
-  NativeRegisterContextSP GetRegisterContext() override;
+  NativeRegisterContext& GetRegisterContext() override;
 
   Status SetWatchpoint(lldb::addr_t addr, size_t size, uint32_t watch_flags,
                        bool hardware) override;
@@ -67,7 +67,7 @@
   // ---------------------------------------------------------------------
   lldb::StateType m_state;
   ThreadStopInfo m_stop_info;
-  NativeRegisterContextSP m_reg_context_sp;
+  std::unique_ptr<NativeRegisterContext> m_reg_context_up;
   std::string m_stop_description;
   using WatchpointIndexMap = std::map<lldb::addr_t, uint32_t>;
   WatchpointIndexMap m_watchpoint_index_map;
Index: source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
===================================================================
--- source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
+++ source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
@@ -27,7 +27,9 @@
 NativeThreadNetBSD::NativeThreadNetBSD(NativeProcessNetBSD &process,
                                        lldb::tid_t tid)
     : NativeThreadProtocol(process, tid), m_state(StateType::eStateInvalid),
-      m_stop_info(), m_reg_context_sp(), m_stop_description() {}
+      m_stop_info(), m_reg_context_up(
+NativeRegisterContextNetBSD::CreateHostNativeRegisterContextNetBSD(process.GetArchitecture(), *this)
+), m_stop_description() {}
 
 void NativeThreadNetBSD::SetStoppedBySignal(uint32_t signo,
                                             const siginfo_t *info) {
@@ -77,10 +79,10 @@
   lldbassert(wp_index != LLDB_INVALID_INDEX32 && "wp_index cannot be invalid");
 
   std::ostringstream ostr;
-  ostr << GetRegisterContext()->GetWatchpointAddress(wp_index) << " ";
+  ostr << GetRegisterContext().GetWatchpointAddress(wp_index) << " ";
   ostr << wp_index;
 
-  ostr << " " << GetRegisterContext()->GetWatchpointHitAddress(wp_index);
+  ostr << " " << GetRegisterContext().GetWatchpointHitAddress(wp_index);
 
   m_stop_description = ostr.str();
 
@@ -139,17 +141,9 @@
   llvm_unreachable("unhandled StateType!");
 }
 
-NativeRegisterContextSP NativeThreadNetBSD::GetRegisterContext() {
-  // Return the register context if we already created it.
-  if (m_reg_context_sp)
-    return m_reg_context_sp;
-
-  const uint32_t concrete_frame_idx = 0;
-  m_reg_context_sp.reset(
-      NativeRegisterContextNetBSD::CreateHostNativeRegisterContextNetBSD(
-          m_process.GetArchitecture(), *this, concrete_frame_idx));
-
-  return m_reg_context_sp;
+NativeRegisterContext& NativeThreadNetBSD::GetRegisterContext() {
+  assert(m_reg_context_up);
+return  *m_reg_context_up;
 }
 
 Status NativeThreadNetBSD::SetWatchpoint(lldb::addr_t addr, size_t size,
@@ -161,8 +155,7 @@
   Status error = RemoveWatchpoint(addr);
   if (error.Fail())
     return error;
-  NativeRegisterContextSP reg_ctx = GetRegisterContext();
-  uint32_t wp_index = reg_ctx->SetHardwareWatchpoint(addr, size, watch_flags);
+  uint32_t wp_index = GetRegisterContext().SetHardwareWatchpoint(addr, size, watch_flags);
   if (wp_index == LLDB_INVALID_INDEX32)
     return Status("Setting hardware watchpoint failed.");
   m_watchpoint_index_map.insert({addr, wp_index});
@@ -175,7 +168,7 @@
     return Status();
   uint32_t wp_index = wp->second;
   m_watchpoint_index_map.erase(wp);
-  if (GetRegisterContext()->ClearHardwareWatchpoint(wp_index))
+  if (GetRegisterContext().ClearHardwareWatchpoint(wp_index))
     return Status();
   return Status("Clearing hardware watchpoint failed.");
 }
@@ -189,8 +182,7 @@
   if (error.Fail())
     return error;
 
-  NativeRegisterContextSP reg_ctx = GetRegisterContext();
-  uint32_t bp_index = reg_ctx->SetHardwareBreakpoint(addr, size);
+  uint32_t bp_index = GetRegisterContext().SetHardwareBreakpoint(addr, size);
 
   if (bp_index == LLDB_INVALID_INDEX32)
     return Status("Setting hardware breakpoint failed.");
@@ -205,7 +197,7 @@
     return Status();
 
   uint32_t bp_index = bp->second;
-  if (GetRegisterContext()->ClearHardwareBreakpoint(bp_index)) {
+  if (GetRegisterContext().ClearHardwareBreakpoint(bp_index)) {
     m_hw_break_index_map.erase(bp);
     return Status();
   }
Index: source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
===================================================================
--- source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
+++ source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
@@ -23,7 +23,7 @@
   /// of the register_info_interface pointer.
   ///
   NativeRegisterContextRegisterInfo(
-      NativeThreadProtocol &thread, uint32_t concrete_frame_idx,
+      NativeThreadProtocol &thread,
       RegisterInfoInterface *register_info_interface);
 
   uint32_t GetRegisterCount() const override;
Index: source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.cpp
===================================================================
--- source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.cpp
+++ source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.cpp
@@ -14,9 +14,9 @@
 using namespace lldb_private;
 
 NativeRegisterContextRegisterInfo::NativeRegisterContextRegisterInfo(
-    NativeThreadProtocol &thread, uint32_t concrete_frame_idx,
+    NativeThreadProtocol &thread,
     RegisterInfoInterface *register_info_interface)
-    : NativeRegisterContext(thread, concrete_frame_idx),
+    : NativeRegisterContext(thread),
       m_register_info_interface_up(register_info_interface) {
   assert(register_info_interface && "null register_info_interface");
 }
Index: source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
===================================================================
--- source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -396,12 +396,12 @@
 }
 
 static void WriteRegisterValueInHexFixedWidth(
-    StreamString &response, NativeRegisterContextSP &reg_ctx_sp,
+    StreamString &response, NativeRegisterContext &reg_ctx,
     const RegisterInfo &reg_info, const RegisterValue *reg_value_p,
     lldb::ByteOrder byte_order) {
   RegisterValue reg_value;
   if (!reg_value_p) {
-    Status error = reg_ctx_sp->ReadRegister(&reg_info, reg_value);
+    Status error = reg_ctx.ReadRegister(&reg_info, reg_value);
     if (error.Success())
       reg_value_p = &reg_value;
     // else log.
@@ -423,9 +423,7 @@
 static JSONObject::SP GetRegistersAsJSON(NativeThreadProtocol &thread) {
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_THREAD));
 
-  NativeRegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
-  if (!reg_ctx_sp)
-    return nullptr;
+  NativeRegisterContext& reg_ctx = thread.GetRegisterContext();
 
   JSONObject::SP register_object_sp = std::make_shared<JSONObject>();
 
@@ -448,14 +446,14 @@
 
   for (const uint32_t *generic_reg_p = k_expedited_registers;
        *generic_reg_p != LLDB_INVALID_REGNUM; ++generic_reg_p) {
-    uint32_t reg_num = reg_ctx_sp->ConvertRegisterKindToRegisterNumber(
+    uint32_t reg_num = reg_ctx.ConvertRegisterKindToRegisterNumber(
         eRegisterKindGeneric, *generic_reg_p);
     if (reg_num == LLDB_INVALID_REGNUM)
       continue; // Target does not support the given register.
 #endif
 
     const RegisterInfo *const reg_info_p =
-        reg_ctx_sp->GetRegisterInfoAtIndex(reg_num);
+        reg_ctx.GetRegisterInfoAtIndex(reg_num);
     if (reg_info_p == nullptr) {
       if (log)
         log->Printf(
@@ -469,7 +467,7 @@
                 // registers.
 
     RegisterValue reg_value;
-    Status error = reg_ctx_sp->ReadRegister(reg_info_p, reg_value);
+    Status error = reg_ctx.ReadRegister(reg_info_p, reg_value);
     if (error.Fail()) {
       if (log)
         log->Printf("%s failed to read register '%s' index %" PRIu32 ": %s",
@@ -480,7 +478,7 @@
     }
 
     StreamString stream;
-    WriteRegisterValueInHexFixedWidth(stream, reg_ctx_sp, *reg_info_p,
+    WriteRegisterValueInHexFixedWidth(stream, reg_ctx, *reg_info_p,
                                       &reg_value, lldb::eByteOrderBig);
 
     register_object_sp->SetObject(
@@ -702,17 +700,15 @@
     for (NativeThreadProtocol *thread;
          (thread = m_debugged_process_up->GetThreadAtIndex(i)) != nullptr;
          ++i) {
-      NativeRegisterContextSP reg_ctx_sp = thread->GetRegisterContext();
-      if (!reg_ctx_sp)
-        continue;
+      NativeRegisterContext& reg_ctx = thread->GetRegisterContext();
 
-      uint32_t reg_to_read = reg_ctx_sp->ConvertRegisterKindToRegisterNumber(
+      uint32_t reg_to_read = reg_ctx.ConvertRegisterKindToRegisterNumber(
           eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
       const RegisterInfo *const reg_info_p =
-          reg_ctx_sp->GetRegisterInfoAtIndex(reg_to_read);
+          reg_ctx.GetRegisterInfoAtIndex(reg_to_read);
 
       RegisterValue reg_value;
-      Status error = reg_ctx_sp->ReadRegister(reg_info_p, reg_value);
+      Status error = reg_ctx.ReadRegister(reg_info_p, reg_value);
       if (error.Fail()) {
         if (log)
           log->Printf("%s failed to read register '%s' index %" PRIu32 ": %s",
@@ -725,7 +721,7 @@
 
       response.PutChar(delimiter);
       delimiter = ',';
-      WriteRegisterValueInHexFixedWidth(response, reg_ctx_sp, *reg_info_p,
+      WriteRegisterValueInHexFixedWidth(response, reg_ctx, *reg_info_p,
                                         &reg_value, endian::InlHostByteOrder());
     }
 
@@ -737,49 +733,48 @@
   //
 
   // Grab the register context.
-  NativeRegisterContextSP reg_ctx_sp = thread->GetRegisterContext();
-  if (reg_ctx_sp) {
-    // Expedite all registers in the first register set (i.e. should be GPRs)
-    // that are not contained in other registers.
-    const RegisterSet *reg_set_p;
-    if (reg_ctx_sp->GetRegisterSetCount() > 0 &&
-        ((reg_set_p = reg_ctx_sp->GetRegisterSet(0)) != nullptr)) {
-      if (log)
-        log->Printf("GDBRemoteCommunicationServerLLGS::%s expediting registers "
-                    "from set '%s' (registers set count: %zu)",
-                    __FUNCTION__,
-                    reg_set_p->name ? reg_set_p->name : "<unnamed-set>",
-                    reg_set_p->num_registers);
-
-      for (const uint32_t *reg_num_p = reg_set_p->registers;
-           *reg_num_p != LLDB_INVALID_REGNUM; ++reg_num_p) {
-        const RegisterInfo *const reg_info_p =
-            reg_ctx_sp->GetRegisterInfoAtIndex(*reg_num_p);
-        if (reg_info_p == nullptr) {
+  NativeRegisterContext& reg_ctx = thread->GetRegisterContext();
+  // Expedite all registers in the first register set (i.e. should be GPRs)
+  // that are not contained in other registers.
+  const RegisterSet *reg_set_p;
+  if (reg_ctx.GetRegisterSetCount() > 0 &&
+      ((reg_set_p = reg_ctx.GetRegisterSet(0)) != nullptr)) {
+    if (log)
+      log->Printf("GDBRemoteCommunicationServerLLGS::%s expediting registers "
+                  "from set '%s' (registers set count: %zu)",
+                  __FUNCTION__,
+                  reg_set_p->name ? reg_set_p->name : "<unnamed-set>",
+                  reg_set_p->num_registers);
+
+    for (const uint32_t *reg_num_p = reg_set_p->registers;
+         *reg_num_p != LLDB_INVALID_REGNUM; ++reg_num_p) {
+      const RegisterInfo *const reg_info_p =
+          reg_ctx.GetRegisterInfoAtIndex(*reg_num_p);
+      if (reg_info_p == nullptr) {
+        if (log)
+          log->Printf("GDBRemoteCommunicationServerLLGS::%s failed to get "
+                      "register info for register set '%s', register index "
+                      "%" PRIu32,
+                      __FUNCTION__,
+                      reg_set_p->name ? reg_set_p->name : "<unnamed-set>",
+                      *reg_num_p);
+      } else if (reg_info_p->value_regs == nullptr) {
+        // Only expediate registers that are not contained in other registers.
+        RegisterValue reg_value;
+        Status error = reg_ctx.ReadRegister(reg_info_p, reg_value);
+        if (error.Success()) {
+          response.Printf("%.02x:", *reg_num_p);
+          WriteRegisterValueInHexFixedWidth(response, reg_ctx, *reg_info_p,
+                                            &reg_value, lldb::eByteOrderBig);
+          response.PutChar(';');
+        } else {
           if (log)
-            log->Printf("GDBRemoteCommunicationServerLLGS::%s failed to get "
-                        "register info for register set '%s', register index "
-                        "%" PRIu32,
+            log->Printf("GDBRemoteCommunicationServerLLGS::%s failed to read "
+                        "register '%s' index %" PRIu32 ": %s",
                         __FUNCTION__,
-                        reg_set_p->name ? reg_set_p->name : "<unnamed-set>",
-                        *reg_num_p);
-        } else if (reg_info_p->value_regs == nullptr) {
-          // Only expediate registers that are not contained in other registers.
-          RegisterValue reg_value;
-          Status error = reg_ctx_sp->ReadRegister(reg_info_p, reg_value);
-          if (error.Success()) {
-            response.Printf("%.02x:", *reg_num_p);
-            WriteRegisterValueInHexFixedWidth(response, reg_ctx_sp, *reg_info_p,
-                                              &reg_value, lldb::eByteOrderBig);
-            response.PutChar(';');
-          } else {
-            if (log)
-              log->Printf("GDBRemoteCommunicationServerLLGS::%s failed to read "
-                          "register '%s' index %" PRIu32 ": %s",
-                          __FUNCTION__, reg_info_p->name ? reg_info_p->name
-                                                         : "<unnamed-register>",
-                          *reg_num_p, error.AsCString());
-          }
+                        reg_info_p->name ? reg_info_p->name
+                                         : "<unnamed-register>",
+                        *reg_num_p, error.AsCString());
         }
       }
     }
@@ -1695,9 +1690,7 @@
     return SendErrorResponse(69);
 
   // Get the register context for the first thread.
-  NativeRegisterContextSP reg_context_sp(thread->GetRegisterContext());
-  if (!reg_context_sp)
-    return SendErrorResponse(69);
+  NativeRegisterContext &reg_context = thread->GetRegisterContext();
 
   // Parse out the register number from the request.
   packet.SetFilePos(strlen("qRegisterInfo"));
@@ -1708,11 +1701,10 @@
 
   // Return the end of registers response if we've iterated one past the end of
   // the register set.
-  if (reg_index >= reg_context_sp->GetUserRegisterCount())
+  if (reg_index >= reg_context.GetUserRegisterCount())
     return SendErrorResponse(69);
 
-  const RegisterInfo *reg_info =
-      reg_context_sp->GetRegisterInfoAtIndex(reg_index);
+  const RegisterInfo *reg_info = reg_context.GetRegisterInfoAtIndex(reg_index);
   if (!reg_info)
     return SendErrorResponse(69);
 
@@ -1794,7 +1786,7 @@
   };
 
   const char *const register_set_name =
-      reg_context_sp->GetRegisterSetNameForRegisterAtIndex(reg_index);
+      reg_context.GetRegisterSetNameForRegisterAtIndex(reg_index);
   if (register_set_name) {
     response.PutCString("set:");
     response.PutCString(register_set_name);
@@ -1955,28 +1947,20 @@
   }
 
   // Get the thread's register context.
-  NativeRegisterContextSP reg_context_sp(thread->GetRegisterContext());
-  if (!reg_context_sp) {
-    LLDB_LOG(
-        log,
-        "pid {0} tid {1} failed, no register context available for the thread",
-        m_debugged_process_up->GetID(), thread->GetID());
-    return SendErrorResponse(0x15);
-  }
+  NativeRegisterContext &reg_context = thread->GetRegisterContext();
 
   // Return the end of registers response if we've iterated one past the end of
   // the register set.
-  if (reg_index >= reg_context_sp->GetUserRegisterCount()) {
+  if (reg_index >= reg_context.GetUserRegisterCount()) {
     if (log)
       log->Printf("GDBRemoteCommunicationServerLLGS::%s failed, requested "
                   "register %" PRIu32 " beyond register count %" PRIu32,
                   __FUNCTION__, reg_index,
-                  reg_context_sp->GetUserRegisterCount());
+                  reg_context.GetUserRegisterCount());
     return SendErrorResponse(0x15);
   }
 
-  const RegisterInfo *reg_info =
-      reg_context_sp->GetRegisterInfoAtIndex(reg_index);
+  const RegisterInfo *reg_info = reg_context.GetRegisterInfoAtIndex(reg_index);
   if (!reg_info) {
     if (log)
       log->Printf("GDBRemoteCommunicationServerLLGS::%s failed, requested "
@@ -1990,7 +1974,7 @@
 
   // Retrieve the value
   RegisterValue reg_value;
-  Status error = reg_context_sp->ReadRegister(reg_info, reg_value);
+  Status error = reg_context.ReadRegister(reg_info, reg_value);
   if (error.Fail()) {
     if (log)
       log->Printf("GDBRemoteCommunicationServerLLGS::%s failed, read of "
@@ -2056,18 +2040,8 @@
   }
 
   // Get the thread's register context.
-  NativeRegisterContextSP reg_context_sp(thread->GetRegisterContext());
-  if (!reg_context_sp) {
-    if (log)
-      log->Printf(
-          "GDBRemoteCommunicationServerLLGS::%s pid %" PRIu64 " tid %" PRIu64
-          " failed, no register context available for the thread",
-          __FUNCTION__, m_debugged_process_up->GetID(), thread->GetID());
-    return SendErrorResponse(0x15);
-  }
-
-  const RegisterInfo *reg_info =
-      reg_context_sp->GetRegisterInfoAtIndex(reg_index);
+  NativeRegisterContext &reg_context = thread->GetRegisterContext();
+  const RegisterInfo *reg_info = reg_context.GetRegisterInfoAtIndex(reg_index);
   if (!reg_info) {
     if (log)
       log->Printf("GDBRemoteCommunicationServerLLGS::%s failed, requested "
@@ -2078,12 +2052,11 @@
 
   // Return the end of registers response if we've iterated one past the end of
   // the register set.
-  if (reg_index >= reg_context_sp->GetUserRegisterCount()) {
+  if (reg_index >= reg_context.GetUserRegisterCount()) {
     if (log)
       log->Printf("GDBRemoteCommunicationServerLLGS::%s failed, requested "
                   "register %" PRIu32 " beyond register count %" PRIu32,
-                  __FUNCTION__, reg_index,
-                  reg_context_sp->GetUserRegisterCount());
+                  __FUNCTION__, reg_index, reg_context.GetUserRegisterCount());
     return SendErrorResponse(0x47);
   }
 
@@ -2101,7 +2074,7 @@
   RegisterValue reg_value(
       reg_bytes, reg_size,
       m_debugged_process_up->GetArchitecture().GetByteOrder());
-  Status error = reg_context_sp->WriteRegister(reg_info, reg_value);
+  Status error = reg_context.WriteRegister(reg_info, reg_value);
   if (error.Fail()) {
     if (log)
       log->Printf("GDBRemoteCommunicationServerLLGS::%s failed, write of "
@@ -2861,18 +2834,11 @@
   }
 
   // Grab the register context for the thread.
-  NativeRegisterContextSP reg_context_sp(thread->GetRegisterContext());
-  if (!reg_context_sp) {
-    LLDB_LOG(
-        log,
-        "pid {0} tid {1} failed, no register context available for the thread",
-        m_debugged_process_up->GetID(), thread->GetID());
-    return SendErrorResponse(0x15);
-  }
+  NativeRegisterContext& reg_context = thread->GetRegisterContext();
 
   // Save registers to a buffer.
   DataBufferSP register_data_sp;
-  Status error = reg_context_sp->ReadAllRegisterValues(register_data_sp);
+  Status error = reg_context.ReadAllRegisterValues(register_data_sp);
   if (error.Fail()) {
     LLDB_LOG(log, "pid {0} failed to save all register values: {1}",
              m_debugged_process_up->GetID(), error);
@@ -2926,14 +2892,7 @@
   }
 
   // Grab the register context for the thread.
-  NativeRegisterContextSP reg_context_sp(thread->GetRegisterContext());
-  if (!reg_context_sp) {
-    LLDB_LOG(
-        log,
-        "pid {0} tid {1} failed, no register context available for the thread",
-        m_debugged_process_up->GetID(), thread->GetID());
-    return SendErrorResponse(0x15);
-  }
+  NativeRegisterContext &reg_context = thread->GetRegisterContext();
 
   // Retrieve register state buffer, then remove from the list.
   DataBufferSP register_data_sp;
@@ -2954,7 +2913,7 @@
     m_saved_registers_map.erase(it);
   }
 
-  Status error = reg_context_sp->WriteAllRegisterValues(register_data_sp);
+  Status error = reg_context.WriteAllRegisterValues(register_data_sp);
   if (error.Fail()) {
     LLDB_LOG(log, "pid {0} failed to restore all register values: {1}",
              m_debugged_process_up->GetID(), error);