[LLDB] Move NativeRegisterContextLinux/RegisterContextPOSIX*_arm to RegisterInfoAndSetInterface

[omjavaid]

Summary

This patch removes register set definitions and other redundant code from NativeRegisterContextLinux/RegisterContextPOSIX*_arm.
Register sets are now moved under RegisterInfosPOSIX_arm which now uses RegisterInfoAndSetInterface. This is similar to what we earlier did for AArch64.

[omjavaid]

NativeRegisterContextLinux_arm still uses "Plugins/Process/Utility/lldb-arm-register-enums.h" which I intend to deal in a later patch.

[omjavaid]

Fixed last diff it contained an invalid change.

[omjavaid]

Adding changes to FreeBSD/* missed earlier.

[labath]

This is great, thanks for doing this. Just a couple of minor comments inline.

lldb/source/Plugins/Process/FreeBSD/FreeBSDThread.cpp

167

delete this break.

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.cpp

61–63

Actually, I'd just change this to assert(target_arch.GetMachine() == llvm::Triple::arm)

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm.cpp

93–95

You can skip this if you want to keep things consistent (or put it in a separate patch, etc), but I just realized that this is completely unnecessary. Instead of the assert, we could just make the assert expression _be_ the definition of the constant (k_num_gpr_registers = ((sizeof g_gpr_regnums_arm / sizeof g_gpr_regnums_arm[0]) - 1)). Given that llvm::array_lengthof is constexpr, it might even work to make this llvm::array_lengthof(g_gpr_regnums_arm)-1.

lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp

84–86

I think you should either keep both aarch64 and arm cases, or delete both of them. I'm fine with either.

lldb/source/Plugins/Process/FreeBSD/FreeBSDThread.cpp

if (!m_reg_context_sp) {
     m_posix_thread = nullptr;
 
     RegisterInfoInterface *reg_interface = nullptr;
     const ArchSpec &target_arch = GetProcess()->GetTarget().GetArchitecture();
 
     assert(target_arch.GetTriple().getOS() == llvm::Triple::FreeBSD);
     switch (target_arch.GetMachine()) {
     case llvm::Triple::aarch64:
       break;
     case llvm::Triple::arm:
-      reg_interface = new RegisterInfoPOSIX_arm(target_arch);
       break;
     case llvm::Triple::ppc:
 #ifndef __powerpc64__
       reg_interface = new RegisterContextFreeBSD_powerpc32(target_arch);
       break;
 #endif
     case llvm::Triple::ppc64:
       reg_interface = new RegisterContextFreeBSD_powerpc64(target_arch);
case llvm::Triple::aarch64: {
           new RegisterContextPOSIXProcessMonitor_arm64(
               *this, std::make_unique<RegisterInfoPOSIX_arm64>(target_arch));
       m_posix_thread = reg_ctx;
       m_reg_context_sp.reset(reg_ctx);
       break;
     }
     case llvm::Triple::arm: {
       RegisterContextPOSIXProcessMonitor_arm *reg_ctx =
-          new RegisterContextPOSIXProcessMonitor_arm(*this, 0, reg_interface);
+          new RegisterContextPOSIXProcessMonitor_arm(
+              *this, std::make_unique<RegisterInfoPOSIX_arm>(target_arch));
       m_posix_thread = reg_ctx;
       m_reg_context_sp.reset(reg_ctx);
       break;
     }
     case llvm::Triple::mips64: {
       RegisterContextPOSIXProcessMonitor_mips64 *reg_ctx =
           new RegisterContextPOSIXProcessMonitor_mips64(*this, 0,
                                                         reg_interface);

lldb/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm.h

 
 #include "Plugins/Process/Utility/RegisterContextPOSIX_arm.h"
 #include "RegisterContextPOSIX.h"
 
 class RegisterContextPOSIXProcessMonitor_arm : public RegisterContextPOSIX_arm,
                                                public POSIXBreakpointProtocol {
 public:
   RegisterContextPOSIXProcessMonitor_arm(
-      lldb_private::Thread &thread, uint32_t concrete_frame_idx,
-      lldb_private::RegisterInfoInterface *register_info);
+      lldb_private::Thread &thread,
+      std::unique_ptr<RegisterInfoPOSIX_arm> register_info);
 
 protected:
   bool ReadGPR();
 
   bool ReadFPR();
 
   bool WriteGPR();
 

lldb/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm.cpp

 #include "Plugins/Process/Utility/RegisterContextPOSIX_arm.h"
 
 using namespace lldb_private;
 using namespace lldb;
 
 #define REG_CONTEXT_SIZE (GetGPRSize())
 
 RegisterContextPOSIXProcessMonitor_arm::RegisterContextPOSIXProcessMonitor_arm(
-    Thread &thread, uint32_t concrete_frame_idx,
-    lldb_private::RegisterInfoInterface *register_info)
-    : RegisterContextPOSIX_arm(thread, concrete_frame_idx, register_info) {}
+    lldb_private::Thread &thread,
+    std::unique_ptr<RegisterInfoPOSIX_arm> register_info)
+    : RegisterContextPOSIX_arm(thread, std::move(register_info)) {}
 
 ProcessMonitor &RegisterContextPOSIXProcessMonitor_arm::GetMonitor() {
   ProcessSP base = CalculateProcess();
   ProcessFreeBSD *process = static_cast<ProcessFreeBSD *>(base.get());
   return process->GetMonitor();
 }
 
 bool RegisterContextPOSIXProcessMonitor_arm::ReadGPR() {

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.h

 //===-- NativeRegisterContextLinux_arm.h ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #if defined(__arm__) || defined(__arm64__) || defined(__aarch64__)
 
 #ifndef lldb_NativeRegisterContextLinux_arm_h
 #define lldb_NativeRegisterContextLinux_arm_h
 
 #include "Plugins/Process/Linux/NativeRegisterContextLinux.h"
+#include "Plugins/Process/Utility/RegisterInfoPOSIX_arm.h"
 #include "Plugins/Process/Utility/lldb-arm-register-enums.h"
 
 namespace lldb_private {
 namespace process_linux {
 
 class NativeProcessLinux;
 
 class NativeRegisterContextLinux_arm : public NativeRegisterContextLinux {
protected:
 
   void *GetGPRBuffer() override { return &m_gpr_arm; }
 
   void *GetFPRBuffer() override { return &m_fpr; }
 
   size_t GetFPRSize() override { return sizeof(m_fpr); }
 
 private:
-  struct RegInfo {
-    uint32_t num_registers;
-    uint32_t num_gpr_registers;
-    uint32_t num_fpr_registers;
-
-    uint32_t last_gpr;
-    uint32_t first_fpr;
-    uint32_t last_fpr;
-
-    uint32_t first_fpr_v;
-    uint32_t last_fpr_v;
-
-    uint32_t gpr_flags;
-  };
-
-  struct QReg {
-    uint8_t bytes[16];
-  };
-
-  struct FPU {
-    union {
-      uint32_t s[32];
-      uint64_t d[32];
-      QReg q[16]; // the 128-bit NEON registers
-    } floats;
-    uint32_t fpscr;
-  };
-
   uint32_t m_gpr_arm[k_num_gpr_registers_arm];
-  RegInfo m_reg_info;
-  FPU m_fpr;
+  RegisterInfoPOSIX_arm::FPU m_fpr;
 
   // Debug register info for hardware breakpoints and watchpoints management.
   struct DREG {
     lldb::addr_t address;  // Breakpoint/watchpoint address value.
     lldb::addr_t hit_addr; // Address at which last watchpoint trigger exception
                            // occurred.
     lldb::addr_t real_addr; // Address value that should cause target to stop.
     uint32_t control;       // Breakpoint/watchpoint control value.
private:
 
   bool IsFPR(unsigned reg) const;
 
   Status ReadHardwareDebugInfo();
 
   Status WriteHardwareDebugRegs(int hwbType, int hwb_index);
 
   uint32_t CalculateFprOffset(const RegisterInfo *reg_info) const;
+
+  RegisterInfoPOSIX_arm &GetRegisterInfo() const;
 };
 
 } // namespace process_linux
 } // namespace lldb_private
 
 #endif // #ifndef lldb_NativeRegisterContextLinux_arm_h
 
 #endif // defined(__arm__) || defined(__arm64__) || defined(__aarch64__)

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm.cpp

 #if !defined(PTRACE_TYPE_ARG4)
 #define PTRACE_TYPE_ARG4 void *
 #endif
 
 using namespace lldb;
 using namespace lldb_private;
 using namespace lldb_private::process_linux;
 
-// arm general purpose registers.
-static const uint32_t g_gpr_regnums_arm[] = {
-    gpr_r0_arm,         gpr_r1_arm,   gpr_r2_arm,  gpr_r3_arm, gpr_r4_arm,
-    gpr_r5_arm,         gpr_r6_arm,   gpr_r7_arm,  gpr_r8_arm, gpr_r9_arm,
-    gpr_r10_arm,        gpr_r11_arm,  gpr_r12_arm, gpr_sp_arm, gpr_lr_arm,
-    gpr_pc_arm,         gpr_cpsr_arm,
-    LLDB_INVALID_REGNUM // register sets need to end with this flag
-};
-static_assert(((sizeof g_gpr_regnums_arm / sizeof g_gpr_regnums_arm[0]) - 1) ==
-                  k_num_gpr_registers_arm,
-              "g_gpr_regnums_arm has wrong number of register infos");
-
-// arm floating point registers.
-static const uint32_t g_fpu_regnums_arm[] = {
-    fpu_s0_arm,         fpu_s1_arm,  fpu_s2_arm,    fpu_s3_arm,  fpu_s4_arm,
-    fpu_s5_arm,         fpu_s6_arm,  fpu_s7_arm,    fpu_s8_arm,  fpu_s9_arm,
-    fpu_s10_arm,        fpu_s11_arm, fpu_s12_arm,   fpu_s13_arm, fpu_s14_arm,
-    fpu_s15_arm,        fpu_s16_arm, fpu_s17_arm,   fpu_s18_arm, fpu_s19_arm,
-    fpu_s20_arm,        fpu_s21_arm, fpu_s22_arm,   fpu_s23_arm, fpu_s24_arm,
-    fpu_s25_arm,        fpu_s26_arm, fpu_s27_arm,   fpu_s28_arm, fpu_s29_arm,
-    fpu_s30_arm,        fpu_s31_arm, fpu_fpscr_arm, fpu_d0_arm,  fpu_d1_arm,
-    fpu_d2_arm,         fpu_d3_arm,  fpu_d4_arm,    fpu_d5_arm,  fpu_d6_arm,
-    fpu_d7_arm,         fpu_d8_arm,  fpu_d9_arm,    fpu_d10_arm, fpu_d11_arm,
-    fpu_d12_arm,        fpu_d13_arm, fpu_d14_arm,   fpu_d15_arm, fpu_d16_arm,
-    fpu_d17_arm,        fpu_d18_arm, fpu_d19_arm,   fpu_d20_arm, fpu_d21_arm,
-    fpu_d22_arm,        fpu_d23_arm, fpu_d24_arm,   fpu_d25_arm, fpu_d26_arm,
-    fpu_d27_arm,        fpu_d28_arm, fpu_d29_arm,   fpu_d30_arm, fpu_d31_arm,
-    fpu_q0_arm,         fpu_q1_arm,  fpu_q2_arm,    fpu_q3_arm,  fpu_q4_arm,
-    fpu_q5_arm,         fpu_q6_arm,  fpu_q7_arm,    fpu_q8_arm,  fpu_q9_arm,
-    fpu_q10_arm,        fpu_q11_arm, fpu_q12_arm,   fpu_q13_arm, fpu_q14_arm,
-    fpu_q15_arm,
-    LLDB_INVALID_REGNUM // register sets need to end with this flag
-};
-static_assert(((sizeof g_fpu_regnums_arm / sizeof g_fpu_regnums_arm[0]) - 1) ==
-                  k_num_fpr_registers_arm,
-              "g_fpu_regnums_arm has wrong number of register infos");
-
-namespace {
-// Number of register sets provided by this context.
-enum { k_num_register_sets = 2 };
-}
-
-// Register sets for arm.
-static const RegisterSet g_reg_sets_arm[k_num_register_sets] = {
-    {"General Purpose Registers", "gpr", k_num_gpr_registers_arm,
-     g_gpr_regnums_arm},
-    {"Floating Point Registers", "fpu", k_num_fpr_registers_arm,
-     g_fpu_regnums_arm}};
-
 #if defined(__arm__)
 
 std::unique_ptr<NativeRegisterContextLinux>
 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
     const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
   return std::make_unique<NativeRegisterContextLinux_arm>(target_arch,
                                                            native_thread);
 }
 
 #endif // defined(__arm__)
 
 NativeRegisterContextLinux_arm::NativeRegisterContextLinux_arm(
     const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
     : NativeRegisterContextLinux(native_thread,
                                  new RegisterInfoPOSIX_arm(target_arch)) {
   switch (target_arch.GetMachine()) {
   case llvm::Triple::arm:
-    m_reg_info.num_registers = k_num_registers_arm;
-    m_reg_info.num_gpr_registers = k_num_gpr_registers_arm;
-    m_reg_info.num_fpr_registers = k_num_fpr_registers_arm;
-    m_reg_info.last_gpr = k_last_gpr_arm;
-    m_reg_info.first_fpr = k_first_fpr_arm;
-    m_reg_info.last_fpr = k_last_fpr_arm;
-    m_reg_info.first_fpr_v = fpu_s0_arm;
-    m_reg_info.last_fpr_v = fpu_s31_arm;
-    m_reg_info.gpr_flags = gpr_cpsr_arm;
-    break;
-  default:
-    assert(false && "Unhandled target architecture.");
-    break;
-  }
-
     ::memset(&m_fpr, 0, sizeof(m_fpr));
     ::memset(&m_gpr_arm, 0, sizeof(m_gpr_arm));
     ::memset(&m_hwp_regs, 0, sizeof(m_hwp_regs));
     ::memset(&m_hbr_regs, 0, sizeof(m_hbr_regs));
 
     // 16 is just a maximum value, query hardware for actual watchpoint count
     m_max_hwp_supported = 16;
     m_max_hbp_supported = 16;
     m_refresh_hwdebug_info = true;
+
+    break;
+  default:
+    assert(false && "Unhandled target architecture.");
+    break;
+  }
+}
+
+RegisterInfoPOSIX_arm &NativeRegisterContextLinux_arm::GetRegisterInfo() const {
+  return static_cast<RegisterInfoPOSIX_arm &>(*m_register_info_interface_up);
 }
 
 uint32_t NativeRegisterContextLinux_arm::GetRegisterSetCount() const {
-  return k_num_register_sets;
+  return GetRegisterInfo().GetRegisterSetCount();
 }
 
 uint32_t NativeRegisterContextLinux_arm::GetUserRegisterCount() const {
   uint32_t count = 0;
-  for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index)
-    count += g_reg_sets_arm[set_index].num_registers;
+  for (uint32_t set_index = 0; set_index < GetRegisterSetCount(); ++set_index)
+    count += GetRegisterSet(set_index)->num_registers;
   return count;
 }
 
 const RegisterSet *
 NativeRegisterContextLinux_arm::GetRegisterSet(uint32_t set_index) const {
-  if (set_index < k_num_register_sets)
-    return &g_reg_sets_arm[set_index];
-
-  return nullptr;
+  return GetRegisterInfo().GetRegisterSet(set_index);
 }
 
 Status
 NativeRegisterContextLinux_arm::ReadRegister(const RegisterInfo *reg_info,
                                              RegisterValue &reg_value) {
   Status error;
 
   if (!reg_info) {
Status NativeRegisterContextLinux_arm::WriteAllRegisterValues(
   error = WriteFPR();
   if (error.Fail())
     return error;
 
   return error;
 }
 
 bool NativeRegisterContextLinux_arm::IsGPR(unsigned reg) const {
-  return reg <= m_reg_info.last_gpr; // GPR's come first.
+  if (GetRegisterInfo().GetRegisterSetFromRegisterIndex(reg) ==
+      RegisterInfoPOSIX_arm::GPRegSet)
+    return true;
+  return false;
 }
 
 bool NativeRegisterContextLinux_arm::IsFPR(unsigned reg) const {
-  return (m_reg_info.first_fpr <= reg && reg <= m_reg_info.last_fpr);
+  if (GetRegisterInfo().GetRegisterSetFromRegisterIndex(reg) ==
+      RegisterInfoPOSIX_arm::FPRegSet)
+    return true;
+  return false;
 }
 
 uint32_t NativeRegisterContextLinux_arm::NumSupportedHardwareBreakpoints() {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_BREAKPOINTS));
 
   LLDB_LOGF(log, "NativeRegisterContextLinux_arm::%s()", __FUNCTION__);
 
   Status error;
error = NativeProcessLinux::PtraceWrapper(
         sizeof(unsigned int));
   }
 
   return error;
 }
 
 uint32_t NativeRegisterContextLinux_arm::CalculateFprOffset(
     const RegisterInfo *reg_info) const {
-  return reg_info->byte_offset -
-         GetRegisterInfoAtIndex(m_reg_info.first_fpr)->byte_offset;
+  return reg_info->byte_offset - GetGPRSize();
 }
 
 Status NativeRegisterContextLinux_arm::DoReadRegisterValue(
     uint32_t offset, const char *reg_name, uint32_t size,
     RegisterValue &value) {
   // PTRACE_PEEKUSER don't work in the aarch64 linux kernel used on android
   // devices (always return "Bad address"). To avoid using PTRACE_PEEKUSER we
   // read out the full GPR register set instead. This approach is about 4 times

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_arm.h

 //===-- RegisterContextPOSIX_arm.h ------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERCONTEXTPOSIX_ARM_H
 #define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERCONTEXTPOSIX_ARM_H
 
 #include "RegisterInfoInterface.h"
-#include "lldb-arm-register-enums.h"
+#include "RegisterInfoPOSIX_arm.h"
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
 class ProcessMonitor;
 
 class RegisterContextPOSIX_arm : public lldb_private::RegisterContext {
 public:
-  RegisterContextPOSIX_arm(lldb_private::Thread &thread,
-                           uint32_t concrete_frame_idx,
-                           lldb_private::RegisterInfoInterface *register_info);
+  RegisterContextPOSIX_arm(
+      lldb_private::Thread &thread,
+      std::unique_ptr<RegisterInfoPOSIX_arm> register_info);
 
   ~RegisterContextPOSIX_arm() override;
 
   void Invalidate();
 
   void InvalidateAllRegisters() override;
 
   size_t GetRegisterCount() override;
 
   virtual size_t GetGPRSize();
 
   virtual unsigned GetRegisterSize(unsigned reg);
 
   virtual unsigned GetRegisterOffset(unsigned reg);
 
   const lldb_private::RegisterInfo *GetRegisterInfoAtIndex(size_t reg) override;
 
   size_t GetRegisterSetCount() override;
 
   const lldb_private::RegisterSet *GetRegisterSet(size_t set) override;
 
   const char *GetRegisterName(unsigned reg);
 
 protected:
-  struct RegInfo {
-    uint32_t num_registers;
-    uint32_t num_gpr_registers;
-    uint32_t num_fpr_registers;
-
-    uint32_t last_gpr;
-    uint32_t first_fpr;
-    uint32_t last_fpr;
-
-    uint32_t first_fpr_v;
-    uint32_t last_fpr_v;
-
-    uint32_t gpr_flags;
-  };
-
-  struct QReg {
-    uint8_t bytes[16];
-  };
-
-  struct FPU {
-    union {
-      uint32_t s[32];
-      uint64_t d[32];
-      QReg q[16]; // the 128-bit NEON registers
-    } floats;
-    uint32_t fpscr;
-  };
-
-  uint32_t m_gpr_arm[lldb_private::k_num_gpr_registers_arm]; // 32-bit general
-                                                             // purpose
-                                                             // registers.
-  RegInfo m_reg_info;
-  struct RegisterContextPOSIX_arm::FPU
-      m_fpr; // floating-point registers including extended register sets.
-  std::unique_ptr<lldb_private::RegisterInfoInterface>
-      m_register_info_up; // Register Info Interface (FreeBSD or Linux)
-
-  // Determines if an extended register set is supported on the processor
-  // running the inferior process.
-  virtual bool IsRegisterSetAvailable(size_t set_index);
+  std::unique_ptr<RegisterInfoPOSIX_arm> m_register_info_up;
 
   virtual const lldb_private::RegisterInfo *GetRegisterInfo();
 
   bool IsGPR(unsigned reg);
 
   bool IsFPR(unsigned reg);
 
+  size_t GetFPUSize() { return sizeof(RegisterInfoPOSIX_arm::FPU); }
+
   virtual bool ReadGPR() = 0;
   virtual bool ReadFPR() = 0;
   virtual bool WriteGPR() = 0;
   virtual bool WriteFPR() = 0;
 };
 
 #endif // LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERCONTEXTPOSIX_ARM_H

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_arm.cpp

 #include "lldb/Utility/Scalar.h"
 #include "llvm/Support/Compiler.h"
 
 #include "RegisterContextPOSIX_arm.h"
 
 using namespace lldb;
 using namespace lldb_private;
 
-// arm general purpose registers.
-const uint32_t g_gpr_regnums_arm[] = {
-    gpr_r0_arm,         gpr_r1_arm,   gpr_r2_arm,  gpr_r3_arm, gpr_r4_arm,
-    gpr_r5_arm,         gpr_r6_arm,   gpr_r7_arm,  gpr_r8_arm, gpr_r9_arm,
-    gpr_r10_arm,        gpr_r11_arm,  gpr_r12_arm, gpr_sp_arm, gpr_lr_arm,
-    gpr_pc_arm,         gpr_cpsr_arm,
-    LLDB_INVALID_REGNUM // register sets need to end with this flag
-
-};
-static_assert(((sizeof g_gpr_regnums_arm / sizeof g_gpr_regnums_arm[0]) - 1) ==
-                  k_num_gpr_registers_arm,
-              "g_gpr_regnums_arm has wrong number of register infos");
-
-// arm floating point registers.
-static const uint32_t g_fpu_regnums_arm[] = {
-    fpu_s0_arm,         fpu_s1_arm,  fpu_s2_arm,    fpu_s3_arm,  fpu_s4_arm,
-    fpu_s5_arm,         fpu_s6_arm,  fpu_s7_arm,    fpu_s8_arm,  fpu_s9_arm,
-    fpu_s10_arm,        fpu_s11_arm, fpu_s12_arm,   fpu_s13_arm, fpu_s14_arm,
-    fpu_s15_arm,        fpu_s16_arm, fpu_s17_arm,   fpu_s18_arm, fpu_s19_arm,
-    fpu_s20_arm,        fpu_s21_arm, fpu_s22_arm,   fpu_s23_arm, fpu_s24_arm,
-    fpu_s25_arm,        fpu_s26_arm, fpu_s27_arm,   fpu_s28_arm, fpu_s29_arm,
-    fpu_s30_arm,        fpu_s31_arm, fpu_fpscr_arm, fpu_d0_arm,  fpu_d1_arm,
-    fpu_d2_arm,         fpu_d3_arm,  fpu_d4_arm,    fpu_d5_arm,  fpu_d6_arm,
-    fpu_d7_arm,         fpu_d8_arm,  fpu_d9_arm,    fpu_d10_arm, fpu_d11_arm,
-    fpu_d12_arm,        fpu_d13_arm, fpu_d14_arm,   fpu_d15_arm, fpu_d16_arm,
-    fpu_d17_arm,        fpu_d18_arm, fpu_d19_arm,   fpu_d20_arm, fpu_d21_arm,
-    fpu_d22_arm,        fpu_d23_arm, fpu_d24_arm,   fpu_d25_arm, fpu_d26_arm,
-    fpu_d27_arm,        fpu_d28_arm, fpu_d29_arm,   fpu_d30_arm, fpu_d31_arm,
-    fpu_q0_arm,         fpu_q1_arm,  fpu_q2_arm,    fpu_q3_arm,  fpu_q4_arm,
-    fpu_q5_arm,         fpu_q6_arm,  fpu_q7_arm,    fpu_q8_arm,  fpu_q9_arm,
-    fpu_q10_arm,        fpu_q11_arm, fpu_q12_arm,   fpu_q13_arm, fpu_q14_arm,
-    fpu_q15_arm,
-    LLDB_INVALID_REGNUM // register sets need to end with this flag
-
-};
-static_assert(((sizeof g_fpu_regnums_arm / sizeof g_fpu_regnums_arm[0]) - 1) ==
-                  k_num_fpr_registers_arm,
-              "g_fpu_regnums_arm has wrong number of register infos");
-
-// Number of register sets provided by this context.
-enum { k_num_register_sets = 2 };
-
-// Register sets for arm.
-static const lldb_private::RegisterSet g_reg_sets_arm[k_num_register_sets] = {
-    {"General Purpose Registers", "gpr", k_num_gpr_registers_arm,
-     g_gpr_regnums_arm},
-    {"Floating Point Registers", "fpu", k_num_fpr_registers_arm,
-     g_fpu_regnums_arm}};
-
 bool RegisterContextPOSIX_arm::IsGPR(unsigned reg) {
-  return reg <= m_reg_info.last_gpr; // GPR's come first.
+  if (m_register_info_up->GetRegisterSetFromRegisterIndex(reg) ==
+      RegisterInfoPOSIX_arm::GPRegSet)
+    return true;
+  return false;
 }
 
 bool RegisterContextPOSIX_arm::IsFPR(unsigned reg) {
-  return (m_reg_info.first_fpr <= reg && reg <= m_reg_info.last_fpr);
+  if (m_register_info_up->GetRegisterSetFromRegisterIndex(reg) ==
+      RegisterInfoPOSIX_arm::FPRegSet)
+    return true;
+  return false;
 }
 
 RegisterContextPOSIX_arm::RegisterContextPOSIX_arm(
-    lldb_private::Thread &thread, uint32_t concrete_frame_idx,
-    lldb_private::RegisterInfoInterface *register_info)
-    : lldb_private::RegisterContext(thread, concrete_frame_idx) {
-  m_register_info_up.reset(register_info);
-
-  switch (register_info->m_target_arch.GetMachine()) {
-  case llvm::Triple::arm:
-    m_reg_info.num_registers = k_num_registers_arm;
-    m_reg_info.num_gpr_registers = k_num_gpr_registers_arm;
-    m_reg_info.num_fpr_registers = k_num_fpr_registers_arm;
-    m_reg_info.last_gpr = k_last_gpr_arm;
-    m_reg_info.first_fpr = k_first_fpr_arm;
-    m_reg_info.last_fpr = k_last_fpr_arm;
-    m_reg_info.first_fpr_v = fpu_s0_arm;
-    m_reg_info.last_fpr_v = fpu_s31_arm;
-    m_reg_info.gpr_flags = gpr_cpsr_arm;
-    break;
-  default:
-    assert(false && "Unhandled target architecture.");
-    break;
-  }
-
-  ::memset(&m_fpr, 0, sizeof m_fpr);
-}
+    lldb_private::Thread &thread,
+    std::unique_ptr<RegisterInfoPOSIX_arm> register_info)
+    : lldb_private::RegisterContext(thread, 0),
+      m_register_info_up(std::move(register_info)) {}
 
 RegisterContextPOSIX_arm::~RegisterContextPOSIX_arm() {}
 
 void RegisterContextPOSIX_arm::Invalidate() {}
 
 void RegisterContextPOSIX_arm::InvalidateAllRegisters() {}
 
 unsigned RegisterContextPOSIX_arm::GetRegisterOffset(unsigned reg) {
-  assert(reg < m_reg_info.num_registers && "Invalid register number.");
-  return GetRegisterInfo()[reg].byte_offset;
+  return m_register_info_up->GetRegisterInfo()[reg].byte_offset;
 }
 
 unsigned RegisterContextPOSIX_arm::GetRegisterSize(unsigned reg) {
-  assert(reg < m_reg_info.num_registers && "Invalid register number.");
-  return GetRegisterInfo()[reg].byte_size;
+  return m_register_info_up->GetRegisterInfo()[reg].byte_size;
 }
 
 size_t RegisterContextPOSIX_arm::GetRegisterCount() {
-  size_t num_registers =
-      m_reg_info.num_gpr_registers + m_reg_info.num_fpr_registers;
-  return num_registers;
+  return m_register_info_up->GetRegisterCount();
 }
 
 size_t RegisterContextPOSIX_arm::GetGPRSize() {
   return m_register_info_up->GetGPRSize();
 }
 
 const lldb_private::RegisterInfo *RegisterContextPOSIX_arm::GetRegisterInfo() {
   // Commonly, this method is overridden and g_register_infos is copied and
   // specialized. So, use GetRegisterInfo() rather than g_register_infos in
   // this scope.
   return m_register_info_up->GetRegisterInfo();
 }
 
 const lldb_private::RegisterInfo *
 RegisterContextPOSIX_arm::GetRegisterInfoAtIndex(size_t reg) {
-  if (reg < m_reg_info.num_registers)
+  if (reg < GetRegisterCount())
     return &GetRegisterInfo()[reg];
-  else
-    return nullptr;
+
 }
 
 size_t RegisterContextPOSIX_arm::GetRegisterSetCount() {
-  size_t sets = 0;
-  for (size_t set = 0; set < k_num_register_sets; ++set) {
-    if (IsRegisterSetAvailable(set))
-      ++sets;
-  }
-
-  return sets;
+  return m_register_info_up->GetRegisterSetCount();
 }
 
 const lldb_private::RegisterSet *
 RegisterContextPOSIX_arm::GetRegisterSet(size_t set) {
-  if (IsRegisterSetAvailable(set)) {
-    switch (m_register_info_up->m_target_arch.GetMachine()) {
-    case llvm::Triple::arm:
-      return &g_reg_sets_arm[set];
-    default:
-      assert(false && "Unhandled target architecture.");
-      return nullptr;
-    }
-  }
-  return nullptr;
+  return m_register_info_up->GetRegisterSet(set);
 }
 
 const char *RegisterContextPOSIX_arm::GetRegisterName(unsigned reg) {
-  assert(reg < m_reg_info.num_registers && "Invalid register offset.");
+  if (reg < GetRegisterCount())
     return GetRegisterInfo()[reg].name;
-}
-
-bool RegisterContextPOSIX_arm::IsRegisterSetAvailable(size_t set_index) {
-  return set_index < k_num_register_sets;
+  return nullptr;
 }

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm.h

 //===-- RegisterInfoPOSIX_arm.h ---------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERINFOPOSIX_ARM_H
 #define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERINFOPOSIX_ARM_H
 
-#include "RegisterInfoInterface.h"
+#include "RegisterInfoAndSetInterface.h"
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/lldb-private.h"
 
-class RegisterInfoPOSIX_arm : public lldb_private::RegisterInfoInterface {
+class RegisterInfoPOSIX_arm : public lldb_private::RegisterInfoAndSetInterface {
 public:
+  enum { GPRegSet = 0, FPRegSet, SVERegSet };
+
   struct GPR {
     uint32_t r[16]; // R0-R15
     uint32_t cpsr;  // CPSR
   };
 
   struct QReg {
     uint8_t bytes[16];
   };
struct DBG {
     uint32_t wvr[16];
     uint32_t wcr[16];
   };
 
   RegisterInfoPOSIX_arm(const lldb_private::ArchSpec &target_arch);
 
   size_t GetGPRSize() const override;
 
+  size_t GetFPRSize() const override;
+
   const lldb_private::RegisterInfo *GetRegisterInfo() const override;
 
   uint32_t GetRegisterCount() const override;
 
+  const lldb_private::RegisterSet *
+  GetRegisterSet(size_t reg_set) const override;
+
+  size_t GetRegisterSetCount() const override;
+
+  size_t GetRegisterSetFromRegisterIndex(uint32_t reg_index) const override;
+
 private:
   const lldb_private::RegisterInfo *m_register_info_p;
   uint32_t m_register_info_count;
 };
 
 #endif // LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERINFOPOSIX_ARM_H

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm.cpp

case llvm::Triple::arm:
     return static_cast<uint32_t>(sizeof(g_register_infos_arm) /
                                  sizeof(g_register_infos_arm[0]));
   default:
     assert(false && "Unhandled target architecture.");
     return 0;
   }
 }
 
+// Number of register sets provided by this context.
+enum {
+  k_num_gpr_registers = gpr_cpsr - gpr_r0 + 1,
+  k_num_fpr_registers = fpu_q15 - fpu_s0 + 1,
+  k_num_register_sets = 2
+};
+
+// arm general purpose registers.
+static const uint32_t g_gpr_regnums_arm[] = {
+    gpr_r0,   gpr_r1,
+    gpr_r2,   gpr_r3,
+    gpr_r4,   gpr_r5,
+    gpr_r6,   gpr_r7,
+    gpr_r8,   gpr_r9,
+    gpr_r10,  gpr_r11,
+    gpr_r12,  gpr_sp,
+    gpr_lr,   gpr_pc,
+    gpr_cpsr, LLDB_INVALID_REGNUM // register sets need to end with this flag
+};
+static_assert(((sizeof g_gpr_regnums_arm / sizeof g_gpr_regnums_arm[0]) - 1) ==
+                  k_num_gpr_registers,
+              "g_gpr_regnums_arm has wrong number of register infos");
+
+// arm floating point registers.
+static const uint32_t g_fpu_regnums_arm[] = {
+    fpu_s0,    fpu_s1,
+    fpu_s2,    fpu_s3,
+    fpu_s4,    fpu_s5,
+    fpu_s6,    fpu_s7,
+    fpu_s8,    fpu_s9,
+    fpu_s10,   fpu_s11,
+    fpu_s12,   fpu_s13,
+    fpu_s14,   fpu_s15,
+    fpu_s16,   fpu_s17,
+    fpu_s18,   fpu_s19,
+    fpu_s20,   fpu_s21,
+    fpu_s22,   fpu_s23,
+    fpu_s24,   fpu_s25,
+    fpu_s26,   fpu_s27,
+    fpu_s28,   fpu_s29,
+    fpu_s30,   fpu_s31,
+    fpu_fpscr, fpu_d0,
+    fpu_d1,    fpu_d2,
+    fpu_d3,    fpu_d4,
+    fpu_d5,    fpu_d6,
+    fpu_d7,    fpu_d8,
+    fpu_d9,    fpu_d10,
+    fpu_d11,   fpu_d12,
+    fpu_d13,   fpu_d14,
+    fpu_d15,   fpu_d16,
+    fpu_d17,   fpu_d18,
+    fpu_d19,   fpu_d20,
+    fpu_d21,   fpu_d22,
+    fpu_d23,   fpu_d24,
+    fpu_d25,   fpu_d26,
+    fpu_d27,   fpu_d28,
+    fpu_d29,   fpu_d30,
+    fpu_d31,   fpu_q0,
+    fpu_q1,    fpu_q2,
+    fpu_q3,    fpu_q4,
+    fpu_q5,    fpu_q6,
+    fpu_q7,    fpu_q8,
+    fpu_q9,    fpu_q10,
+    fpu_q11,   fpu_q12,
+    fpu_q13,   fpu_q14,
+    fpu_q15,   LLDB_INVALID_REGNUM // register sets need to end with this flag
+};
+static_assert(((sizeof g_fpu_regnums_arm / sizeof g_fpu_regnums_arm[0]) - 1) ==
+                  k_num_fpr_registers,
+              "g_fpu_regnums_arm has wrong number of register infos");
+
+// Register sets for arm.
+static const RegisterSet g_reg_sets_arm[k_num_register_sets] = {
+    {"General Purpose Registers", "gpr", k_num_gpr_registers,
+     g_gpr_regnums_arm},
+    {"Floating Point Registers", "fpu", k_num_fpr_registers,
+     g_fpu_regnums_arm}};
+
 RegisterInfoPOSIX_arm::RegisterInfoPOSIX_arm(
     const lldb_private::ArchSpec &target_arch)
-    : lldb_private::RegisterInfoInterface(target_arch),
+    : lldb_private::RegisterInfoAndSetInterface(target_arch),
       m_register_info_p(GetRegisterInfoPtr(target_arch)),
       m_register_info_count(GetRegisterInfoCount(target_arch)) {}
 
 size_t RegisterInfoPOSIX_arm::GetGPRSize() const {
   return sizeof(struct RegisterInfoPOSIX_arm::GPR);
 }
 
+size_t RegisterInfoPOSIX_arm::GetFPRSize() const {
+  return sizeof(struct RegisterInfoPOSIX_arm::FPU);
+}
+
 const lldb_private::RegisterInfo *
 RegisterInfoPOSIX_arm::GetRegisterInfo() const {
   return m_register_info_p;
 }
 
+size_t RegisterInfoPOSIX_arm::GetRegisterSetCount() const {
+  return k_num_register_sets;
+}
+
+size_t RegisterInfoPOSIX_arm::GetRegisterSetFromRegisterIndex(
+    uint32_t reg_index) const {
+  if (reg_index <= gpr_cpsr)
+    return GPRegSet;
+  if (reg_index <= fpu_q15)
+    return FPRegSet;
+  return LLDB_INVALID_REGNUM;
+}
+
+const lldb_private::RegisterSet *
+RegisterInfoPOSIX_arm::GetRegisterSet(size_t set_index) const {
+  if (set_index < GetRegisterSetCount())
+    return &g_reg_sets_arm[set_index];
+  return nullptr;
+}
+
 uint32_t RegisterInfoPOSIX_arm::GetRegisterCount() const {
   return m_register_info_count;
 }

lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_arm.h

 #include "Plugins/Process/elf-core/RegisterUtilities.h"
 #include "lldb/Utility/DataBufferHeap.h"
 #include "lldb/Utility/DataExtractor.h"
 
 class RegisterContextCorePOSIX_arm : public RegisterContextPOSIX_arm {
 public:
   RegisterContextCorePOSIX_arm(
       lldb_private::Thread &thread,
-      lldb_private::RegisterInfoInterface *register_info,
+      std::unique_ptr<RegisterInfoPOSIX_arm> register_info,
       const lldb_private::DataExtractor &gpregset,
       llvm::ArrayRef<lldb_private::CoreNote> notes);
 
   ~RegisterContextCorePOSIX_arm() override;
 
   bool ReadRegister(const lldb_private::RegisterInfo *reg_info,
                     lldb_private::RegisterValue &value) override;
 

lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_arm.cpp

 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/RegisterValue.h"
 
 #include <memory>
 
 using namespace lldb_private;
 
 RegisterContextCorePOSIX_arm::RegisterContextCorePOSIX_arm(
-    Thread &thread, RegisterInfoInterface *register_info,
+    Thread &thread, std::unique_ptr<RegisterInfoPOSIX_arm> register_info,
     const DataExtractor &gpregset, llvm::ArrayRef<CoreNote> notes)
-    : RegisterContextPOSIX_arm(thread, 0, register_info) {
+    : RegisterContextPOSIX_arm(thread, std::move(register_info)) {
   m_gpr_buffer = std::make_shared<DataBufferHeap>(gpregset.GetDataStart(),
                                                   gpregset.GetByteSize());
   m_gpr.SetData(m_gpr_buffer);
   m_gpr.SetByteOrder(gpregset.GetByteOrder());
 }
 
 RegisterContextCorePOSIX_arm::~RegisterContextCorePOSIX_arm() {}
 

lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp

if (concrete_frame_idx == 0) {
 
     ProcessElfCore *process = static_cast<ProcessElfCore *>(GetProcess().get());
     ArchSpec arch = process->GetArchitecture();
     RegisterInfoInterface *reg_interface = nullptr;
 
     switch (arch.GetTriple().getOS()) {
     case llvm::Triple::FreeBSD: {
       switch (arch.GetMachine()) {
       case llvm::Triple::aarch64:
         break;
-      case llvm::Triple::arm:
-        reg_interface = new RegisterInfoPOSIX_arm(arch);
-        break;
       case llvm::Triple::ppc:
         reg_interface = new RegisterContextFreeBSD_powerpc32(arch);
         break;
       case llvm::Triple::ppc64:
         reg_interface = new RegisterContextFreeBSD_powerpc64(arch);
         break;
       case llvm::Triple::mips64:
         reg_interface = new RegisterContextFreeBSD_mips64(arch);
         break;
case llvm::Triple::NetBSD: {
       default:
         break;
       }
       break;
     }
 
     case llvm::Triple::Linux: {
       switch (arch.GetMachine()) {
-      case llvm::Triple::arm:
-        reg_interface = new RegisterInfoPOSIX_arm(arch);
-        break;
       case llvm::Triple::aarch64:
         break;
       case llvm::Triple::mipsel:
       case llvm::Triple::mips:
         reg_interface = new RegisterContextLinux_mips(arch);
         break;
       case llvm::Triple::mips64el:
       case llvm::Triple::mips64:
case llvm::Triple::Linux: {
       }
       break;
     }
 
     case llvm::Triple::OpenBSD: {
       switch (arch.GetMachine()) {
       case llvm::Triple::aarch64:
         break;
-      case llvm::Triple::arm:
-        reg_interface = new RegisterInfoPOSIX_arm(arch);
-        break;
       case llvm::Triple::x86:
         reg_interface = new RegisterContextOpenBSD_i386(arch);
         break;
       case llvm::Triple::x86_64:
         reg_interface = new RegisterContextOpenBSD_x86_64(arch);
         break;
       default:
         break;
       }
       break;
     }
 
     default:
       break;
     }
 
-    if (!reg_interface && arch.GetMachine() != llvm::Triple::aarch64) {
+    if (!reg_interface && arch.GetMachine() != llvm::Triple::aarch64 &&
+        arch.GetMachine() != llvm::Triple::arm) {
       LLDB_LOGF(log, "elf-core::%s:: Architecture(%d) or OS(%d) not supported",
                 __FUNCTION__, arch.GetMachine(), arch.GetTriple().getOS());
       assert(false && "Architecture or OS not supported");
     }
 
     switch (arch.GetMachine()) {
     case llvm::Triple::aarch64:
       m_thread_reg_ctx_sp = std::make_shared<RegisterContextCorePOSIX_arm64>(
           *this, std::make_unique<RegisterInfoPOSIX_arm64>(arch),
           m_gpregset_data, m_notes);
       break;
     case llvm::Triple::arm:
       m_thread_reg_ctx_sp = std::make_shared<RegisterContextCorePOSIX_arm>(
-          *this, reg_interface, m_gpregset_data, m_notes);
+          *this, std::make_unique<RegisterInfoPOSIX_arm>(arch), m_gpregset_data,
+          m_notes);
       break;
     case llvm::Triple::mipsel:
     case llvm::Triple::mips:
       m_thread_reg_ctx_sp = std::make_shared<RegisterContextCorePOSIX_mips64>(
           *this, reg_interface, m_gpregset_data, m_notes);
       break;
     case llvm::Triple::mips64:
     case llvm::Triple::mips64el: