lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp - toolchain/llvm-project - Gitiles

 //===-- NativeThreadLinux.cpp --------------------------------- -*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//

 #include "NativeThreadLinux.h"

 #include <signal.h>
 #include <sstream>

 #include "NativeProcessLinux.h"
 #include "NativeRegisterContextLinux_arm64.h"
 #include "NativeRegisterContextLinux_x86_64.h"
 #include "NativeRegisterContextLinux_mips64.h"

 #include "lldb/Core/Log.h"
 #include "lldb/Core/State.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Host/HostInfo.h"
 #include "lldb/Host/HostNativeThread.h"
 #include "lldb/lldb-enumerations.h"

 #include "llvm/ADT/SmallString.h"

 #include "Plugins/Process/POSIX/CrashReason.h"

 #include "Plugins/Process/Utility/RegisterContextLinux_arm64.h"
 #include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
 #include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
 #include "Plugins/Process/Utility/RegisterContextLinux_mips64.h"
 #include "Plugins/Process/Utility/RegisterInfoInterface.h"

 using namespace lldb;
 using namespace lldb_private;

 namespace
 {
     void LogThreadStopInfo (Log &log, const ThreadStopInfo &stop_info, const char *const header)
     {
         switch (stop_info.reason)
         {
             case eStopReasonSignal:
                 log.Printf ("%s: %s signal 0x%02" PRIx32, __FUNCTION__, header, stop_info.details.signal.signo);
                 return;
             case eStopReasonException:
                 log.Printf ("%s: %s exception type 0x%02" PRIx64, __FUNCTION__, header, stop_info.details.exception.type);
                 return;
             case eStopReasonExec:
                 log.Printf ("%s: %s exec, stopping signal 0x%" PRIx32, __FUNCTION__, header, stop_info.details.signal.signo);
                 return;
             default:
                 log.Printf ("%s: %s invalid stop reason %" PRIu32, __FUNCTION__, header, static_cast<uint32_t> (stop_info.reason));
         }
     }
 }

 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 ()
 {
 }

 std::string
 NativeThreadLinux::GetName()
 {
     NativeProcessProtocolSP process_sp = m_process_wp.lock ();
     if (!process_sp)
         return "<unknown: no process>";

     // const NativeProcessLinux *const process = reinterpret_cast<NativeProcessLinux*> (process_sp->get ());
     llvm::SmallString<32> thread_name;
     HostNativeThread::GetName(GetID(), thread_name);
     return thread_name.c_str();
 }

 lldb::StateType
 NativeThreadLinux::GetState ()
 {
     return m_state;
 }


 bool
 NativeThreadLinux::GetStopReason (ThreadStopInfo &stop_info, std::string& description)
 {
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));

     description.clear();

     switch (m_state)
     {
     case eStateStopped:
     case eStateCrashed:
     case eStateExited:
     case eStateSuspended:
     case eStateUnloaded:
         if (log)
             LogThreadStopInfo (*log, m_stop_info, "m_stop_info in thread:");
         stop_info = m_stop_info;
         switch (m_stop_info.reason)
         {
             case StopReason::eStopReasonException:
             case StopReason::eStopReasonBreakpoint:
             case StopReason::eStopReasonWatchpoint:
                 description = m_stop_description;
             default:
                 break;
         }
         if (log)
             LogThreadStopInfo (*log, stop_info, "returned stop_info:");

         return true;

     case eStateInvalid:
     case eStateConnected:
     case eStateAttaching:
     case eStateLaunching:
     case eStateRunning:
     case eStateStepping:
     case eStateDetached:
         if (log)
         {
             log->Printf ("NativeThreadLinux::%s tid %" PRIu64 " in state %s cannot answer stop reason",
                     __FUNCTION__, GetID (), StateAsCString (m_state));
         }
         return false;
     }
     llvm_unreachable("unhandled StateType!");
 }

 lldb_private::NativeRegisterContextSP
 NativeThreadLinux::GetRegisterContext ()
 {
     // Return the register context if we already created it.
     if (m_reg_context_sp)
         return m_reg_context_sp;

     // First select the appropriate RegisterInfoInterface.
     RegisterInfoInterface *reg_interface = nullptr;
     NativeProcessProtocolSP m_process_sp = m_process_wp.lock ();
     if (!m_process_sp)
         return NativeRegisterContextSP ();

     ArchSpec target_arch;
     if (!m_process_sp->GetArchitecture (target_arch))
         return NativeRegisterContextSP ();

     switch (target_arch.GetTriple().getOS())
     {
         case llvm::Triple::Linux:
             switch (target_arch.GetMachine())
             {
             case llvm::Triple::aarch64:
                 assert((HostInfo::GetArchitecture ().GetAddressByteSize() == 8) && "Register setting path assumes this is a 64-bit host");
                 reg_interface = static_cast<RegisterInfoInterface*>(new RegisterContextLinux_arm64(target_arch));
                 break;
             case llvm::Triple::x86:
             case llvm::Triple::x86_64:
                 if (HostInfo::GetArchitecture().GetAddressByteSize() == 4)
                 {
                     // 32-bit hosts run with a RegisterContextLinux_i386 context.
                     reg_interface = static_cast<RegisterInfoInterface*>(new RegisterContextLinux_i386(target_arch));
                 }
                 else
                 {
                     assert((HostInfo::GetArchitecture().GetAddressByteSize() == 8) &&
                            "Register setting path assumes this is a 64-bit host");
                     // X86_64 hosts know how to work with 64-bit and 32-bit EXEs using the x86_64 register context.
                     reg_interface = static_cast<RegisterInfoInterface*> (new RegisterContextLinux_x86_64 (target_arch));
                 }
                 break;
             case llvm::Triple::mips64:
             case llvm::Triple::mips64el:
                 assert((HostInfo::GetArchitecture ().GetAddressByteSize() == 8)
                     && "Register setting path assumes this is a 64-bit host");
                 reg_interface = static_cast<RegisterInfoInterface*>(new RegisterContextLinux_mips64 (target_arch));
                 break;
             default:
                 break;
             }
             break;
         default:
             break;
     }

     assert(reg_interface && "OS or CPU not supported!");
     if (!reg_interface)
         return NativeRegisterContextSP ();

     // Now create the register context.
     switch (target_arch.GetMachine())
     {
 #if 0
         case llvm::Triple::mips64:
         {
             RegisterContextPOSIXProcessMonitor_mips64 *reg_ctx = new RegisterContextPOSIXProcessMonitor_mips64(*this, 0, reg_interface);
             m_posix_thread = reg_ctx;
             m_reg_context_sp.reset(reg_ctx);
             break;
         }
 #endif
         case llvm::Triple::mips64:
         case llvm::Triple::mips64el:
         {
             const uint32_t concrete_frame_idx = 0;
             m_reg_context_sp.reset (new NativeRegisterContextLinux_mips64 (*this, concrete_frame_idx, reg_interface));
             break;
         }
         case llvm::Triple::aarch64:
         {
             const uint32_t concrete_frame_idx = 0;
             m_reg_context_sp.reset (new NativeRegisterContextLinux_arm64(*this, concrete_frame_idx, reg_interface));
             break;
         }
         case llvm::Triple::x86:
         case llvm::Triple::x86_64:
         {
             const uint32_t concrete_frame_idx = 0;
             m_reg_context_sp.reset (new NativeRegisterContextLinux_x86_64(*this, concrete_frame_idx, reg_interface));
             break;
         }
         default:
             break;
     }

     return m_reg_context_sp;
 }

 Error
 NativeThreadLinux::SetWatchpoint (lldb::addr_t addr, size_t size, uint32_t watch_flags, bool hardware)
 {
     if (!hardware)
         return Error ("not implemented");
     if (m_state == eStateLaunching)
         return Error ();
     Error error = RemoveWatchpoint(addr);
     if (error.Fail()) return error;
     NativeRegisterContextSP reg_ctx = GetRegisterContext ();
     uint32_t wp_index =
         reg_ctx->SetHardwareWatchpoint (addr, size, watch_flags);
     if (wp_index == LLDB_INVALID_INDEX32)
         return Error ("Setting hardware watchpoint failed.");
     m_watchpoint_index_map.insert({addr, wp_index});
     return Error ();
 }

 Error
 NativeThreadLinux::RemoveWatchpoint (lldb::addr_t addr)
 {
     auto wp = m_watchpoint_index_map.find(addr);
     if (wp == m_watchpoint_index_map.end())
         return Error ();
     uint32_t wp_index = wp->second;
     m_watchpoint_index_map.erase(wp);
     if (GetRegisterContext()->ClearHardwareWatchpoint(wp_index))
         return Error ();
     return Error ("Clearing hardware watchpoint failed.");
 }

 void
 NativeThreadLinux::SetLaunching ()
 {
     const StateType new_state = StateType::eStateLaunching;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     // Also mark it as stopped since launching temporarily stops the newly created thread
     // in the ptrace machinery.
     m_stop_info.reason = StopReason::eStopReasonSignal;
     m_stop_info.details.signal.signo = SIGSTOP;
 }


 void
 NativeThreadLinux::SetRunning ()
 {
     const StateType new_state = StateType::eStateRunning;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonNone;
     m_stop_description.clear();

     // If watchpoints have been set, but none on this thread,
     // then this is a new thread. So set all existing watchpoints.
     if (m_watchpoint_index_map.empty())
     {
         const auto process_sp = GetProcess();
         if (process_sp)
         {
             const auto &watchpoint_map = process_sp->GetWatchpointMap();
             if (watchpoint_map.empty()) return;
             GetRegisterContext()->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);
             }
         }
     }
 }

 void
 NativeThreadLinux::SetStepping ()
 {
     const StateType new_state = StateType::eStateStepping;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonNone;
 }

 void
 NativeThreadLinux::SetStoppedBySignal (uint32_t signo)
 {
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
     if (log)
         log->Printf ("NativeThreadLinux::%s called with signal 0x%02" PRIx32, __FUNCTION__, signo);

     const StateType new_state = StateType::eStateStopped;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonSignal;
     m_stop_info.details.signal.signo = signo;
 }

 bool
 NativeThreadLinux::IsStopped (int *signo)
 {
     if (!StateIsStoppedState (m_state, false))
         return false;

     // If we are stopped by a signal, return the signo.
     if (signo &&
         m_state == StateType::eStateStopped &&
         m_stop_info.reason == StopReason::eStopReasonSignal)
     {
         *signo = m_stop_info.details.signal.signo;
     }

     // Regardless, we are stopped.
     return true;
 }


 void
 NativeThreadLinux::SetStoppedByExec ()
 {
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
     if (log)
         log->Printf ("NativeThreadLinux::%s()", __FUNCTION__);

     const StateType new_state = StateType::eStateStopped;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonExec;
     m_stop_info.details.signal.signo = SIGSTOP;
 }

 void
 NativeThreadLinux::SetStoppedByBreakpoint ()
 {
     const StateType new_state = StateType::eStateStopped;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonBreakpoint;
     m_stop_info.details.signal.signo = SIGTRAP;
     m_stop_description.clear();
 }

 void
 NativeThreadLinux::SetStoppedByWatchpoint ()
 {
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
     lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
     if (log)
     {
         NativeProcessProtocolSP process_sp = m_process_wp.lock ();
         if (process_sp)
             pid = process_sp->GetID ();
     }

     const StateType new_state = StateType::eStateStopped;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     NativeRegisterContextSP reg_ctx = GetRegisterContext ();
     const uint32_t num_hw_watchpoints = reg_ctx->NumSupportedHardwareWatchpoints ();

     m_stop_description.clear ();
     for (uint32_t wp_index = 0; wp_index < num_hw_watchpoints; ++wp_index)
     {
         if (reg_ctx->IsWatchpointHit (wp_index).Success())
         {
             if (log)
                 log->Printf ("NativeThreadLinux:%s (pid=%" PRIu64 ", tid=%" PRIu64 ") watchpoint found with idx: %u",
                              __FUNCTION__, pid, GetID (), wp_index);

             std::ostringstream ostr;
             ostr << reg_ctx->GetWatchpointAddress (wp_index) << " " << wp_index;
             m_stop_description = ostr.str();

             m_stop_info.reason = StopReason::eStopReasonWatchpoint;
             m_stop_info.details.signal.signo = SIGTRAP;
             return;
         }
     }

     // The process reported a watchpoint was hit, but we haven't found the
     // watchpoint. Assume that a stopped by trace is reported as a hardware
     // watchpoint what happens on some linux kernels (e.g.: android-arm64
     // platfrom-21).

     if (log)
         log->Printf ("NativeThreadLinux:%s (pid=%" PRIu64 ", tid=%" PRIu64 ") none of the watchpoint was hit.",
                      __FUNCTION__, pid, GetID ());

     SetStoppedByTrace ();
 }

 bool
 NativeThreadLinux::IsStoppedAtBreakpoint ()
 {
     return GetState () == StateType::eStateStopped &&
         m_stop_info.reason == StopReason::eStopReasonBreakpoint;
 }

 bool
 NativeThreadLinux::IsStoppedAtWatchpoint ()
 {
     return GetState () == StateType::eStateStopped &&
         m_stop_info.reason == StopReason::eStopReasonWatchpoint;
 }

 void
 NativeThreadLinux::SetStoppedByTrace ()
 {
     const StateType new_state = StateType::eStateStopped;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonTrace;
     m_stop_info.details.signal.signo = SIGTRAP;
 }

 void
 NativeThreadLinux::SetCrashedWithException (const siginfo_t& info)
 {
     const StateType new_state = StateType::eStateCrashed;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonException;
     m_stop_info.details.signal.signo = info.si_signo;

     const auto reason = GetCrashReason (info);
     m_stop_description = GetCrashReasonString (reason, reinterpret_cast<lldb::addr_t> (info.si_addr));
 }

 void
 NativeThreadLinux::SetSuspended ()
 {
     const StateType new_state = StateType::eStateSuspended;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     // FIXME what makes sense here? Do we need a suspended StopReason?
     m_stop_info.reason = StopReason::eStopReasonNone;
 }

 void
 NativeThreadLinux::SetExited ()
 {
     const StateType new_state = StateType::eStateExited;
     MaybeLogStateChange (new_state);
     m_state = new_state;

     m_stop_info.reason = StopReason::eStopReasonThreadExiting;
 }

 void
 NativeThreadLinux::MaybeLogStateChange (lldb::StateType new_state)
 {
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
     // If we're not logging, we're done.
     if (!log)
         return;

     // If this is a state change to the same state, we're done.
     lldb::StateType old_state = m_state;
     if (new_state == old_state)
         return;

     NativeProcessProtocolSP m_process_sp = m_process_wp.lock ();
     lldb::pid_t pid = m_process_sp ? m_process_sp->GetID () : LLDB_INVALID_PROCESS_ID;

     // Log it.
     log->Printf ("NativeThreadLinux: thread (pid=%" PRIu64 ", tid=%" PRIu64 ") changing from state %s to %s", pid, GetID (), StateAsCString (old_state), StateAsCString (new_state));
 }
	//===-- NativeThreadLinux.cpp --------------------------------- -- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//

	#include "NativeThreadLinux.h"

	#include <signal.h>
	#include <sstream>

	#include "NativeProcessLinux.h"
	#include "NativeRegisterContextLinux_arm64.h"
	#include "NativeRegisterContextLinux_x86_64.h"
	#include "NativeRegisterContextLinux_mips64.h"

	#include "lldb/Core/Log.h"
	#include "lldb/Core/State.h"
	#include "lldb/Host/Host.h"
	#include "lldb/Host/HostInfo.h"
	#include "lldb/Host/HostNativeThread.h"
	#include "lldb/lldb-enumerations.h"

	#include "llvm/ADT/SmallString.h"

	#include "Plugins/Process/POSIX/CrashReason.h"

	#include "Plugins/Process/Utility/RegisterContextLinux_arm64.h"
	#include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
	#include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
	#include "Plugins/Process/Utility/RegisterContextLinux_mips64.h"
	#include "Plugins/Process/Utility/RegisterInfoInterface.h"

	using namespace lldb;
	using namespace lldb_private;

	namespace
	{
	void LogThreadStopInfo (Log &log, const ThreadStopInfo &stop_info, const char *const header)
	{
	switch (stop_info.reason)
	{
	case eStopReasonSignal:
	log.Printf ("%s: %s signal 0x%02" PRIx32, __FUNCTION__, header, stop_info.details.signal.signo);
	return;
	case eStopReasonException:
	log.Printf ("%s: %s exception type 0x%02" PRIx64, __FUNCTION__, header, stop_info.details.exception.type);
	return;
	case eStopReasonExec:
	log.Printf ("%s: %s exec, stopping signal 0x%" PRIx32, __FUNCTION__, header, stop_info.details.signal.signo);
	return;
	default:
	log.Printf ("%s: %s invalid stop reason %" PRIu32, __FUNCTION__, header, static_cast<uint32_t> (stop_info.reason));
	}
	}
	}

	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 ()
	{
	}

	std::string
	NativeThreadLinux::GetName()
	{
	NativeProcessProtocolSP process_sp = m_process_wp.lock ();
	if (!process_sp)
	return "<unknown: no process>";

	// const NativeProcessLinux const process = reinterpret_cast<NativeProcessLinux> (process_sp->get ());
	llvm::SmallString<32> thread_name;
	HostNativeThread::GetName(GetID(), thread_name);
	return thread_name.c_str();
	}

	lldb::StateType
	NativeThreadLinux::GetState ()
	{
	return m_state;
	}


	bool
	NativeThreadLinux::GetStopReason (ThreadStopInfo &stop_info, std::string& description)
	{
	Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));

	description.clear();

	switch (m_state)
	{
	case eStateStopped:
	case eStateCrashed:
	case eStateExited:
	case eStateSuspended:
	case eStateUnloaded:
	if (log)
	LogThreadStopInfo (*log, m_stop_info, "m_stop_info in thread:");
	stop_info = m_stop_info;
	switch (m_stop_info.reason)
	{
	case StopReason::eStopReasonException:
	case StopReason::eStopReasonBreakpoint:
	case StopReason::eStopReasonWatchpoint:
	description = m_stop_description;
	default:
	break;
	}
	if (log)
	LogThreadStopInfo (*log, stop_info, "returned stop_info:");

	return true;

	case eStateInvalid:
	case eStateConnected:
	case eStateAttaching:
	case eStateLaunching:
	case eStateRunning:
	case eStateStepping:
	case eStateDetached:
	if (log)
	{
	log->Printf ("NativeThreadLinux::%s tid %" PRIu64 " in state %s cannot answer stop reason",
	__FUNCTION__, GetID (), StateAsCString (m_state));
	}
	return false;
	}
	llvm_unreachable("unhandled StateType!");
	}

	lldb_private::NativeRegisterContextSP
	NativeThreadLinux::GetRegisterContext ()
	{
	// Return the register context if we already created it.
	if (m_reg_context_sp)
	return m_reg_context_sp;

	// First select the appropriate RegisterInfoInterface.
	RegisterInfoInterface *reg_interface = nullptr;
	NativeProcessProtocolSP m_process_sp = m_process_wp.lock ();
	if (!m_process_sp)
	return NativeRegisterContextSP ();

	ArchSpec target_arch;
	if (!m_process_sp->GetArchitecture (target_arch))
	return NativeRegisterContextSP ();

	switch (target_arch.GetTriple().getOS())
	{
	case llvm::Triple::Linux:
	switch (target_arch.GetMachine())
	{
	case llvm::Triple::aarch64:
	assert((HostInfo::GetArchitecture ().GetAddressByteSize() == 8) && "Register setting path assumes this is a 64-bit host");
	reg_interface = static_cast<RegisterInfoInterface*>(new RegisterContextLinux_arm64(target_arch));
	break;
	case llvm::Triple::x86:
	case llvm::Triple::x86_64:
	if (HostInfo::GetArchitecture().GetAddressByteSize() == 4)
	{
	// 32-bit hosts run with a RegisterContextLinux_i386 context.
	reg_interface = static_cast<RegisterInfoInterface*>(new RegisterContextLinux_i386(target_arch));
	}
	else
	{
	assert((HostInfo::GetArchitecture().GetAddressByteSize() == 8) &&
	"Register setting path assumes this is a 64-bit host");
	// X86_64 hosts know how to work with 64-bit and 32-bit EXEs using the x86_64 register context.
	reg_interface = static_cast<RegisterInfoInterface*> (new RegisterContextLinux_x86_64 (target_arch));
	}
	break;
	case llvm::Triple::mips64:
	case llvm::Triple::mips64el:
	assert((HostInfo::GetArchitecture ().GetAddressByteSize() == 8)
	&& "Register setting path assumes this is a 64-bit host");
	reg_interface = static_cast<RegisterInfoInterface*>(new RegisterContextLinux_mips64 (target_arch));
	break;
	default:
	break;
	}
	break;
	default:
	break;
	}

	assert(reg_interface && "OS or CPU not supported!");
	if (!reg_interface)
	return NativeRegisterContextSP ();

	// Now create the register context.
	switch (target_arch.GetMachine())
	{
	#if 0
	case llvm::Triple::mips64:
	{
	RegisterContextPOSIXProcessMonitor_mips64 reg_ctx = new RegisterContextPOSIXProcessMonitor_mips64(this, 0, reg_interface);
	m_posix_thread = reg_ctx;
	m_reg_context_sp.reset(reg_ctx);
	break;
	}
	#endif
	case llvm::Triple::mips64:
	case llvm::Triple::mips64el:
	{
	const uint32_t concrete_frame_idx = 0;
	m_reg_context_sp.reset (new NativeRegisterContextLinux_mips64 (*this, concrete_frame_idx, reg_interface));
	break;
	}
	case llvm::Triple::aarch64:
	{
	const uint32_t concrete_frame_idx = 0;
	m_reg_context_sp.reset (new NativeRegisterContextLinux_arm64(*this, concrete_frame_idx, reg_interface));
	break;
	}
	case llvm::Triple::x86:
	case llvm::Triple::x86_64:
	{
	const uint32_t concrete_frame_idx = 0;
	m_reg_context_sp.reset (new NativeRegisterContextLinux_x86_64(*this, concrete_frame_idx, reg_interface));
	break;
	}
	default:
	break;
	}

	return m_reg_context_sp;
	}

	Error
	NativeThreadLinux::SetWatchpoint (lldb::addr_t addr, size_t size, uint32_t watch_flags, bool hardware)
	{
	if (!hardware)
	return Error ("not implemented");
	if (m_state == eStateLaunching)
	return Error ();
	Error error = RemoveWatchpoint(addr);
	if (error.Fail()) return error;
	NativeRegisterContextSP reg_ctx = GetRegisterContext ();
	uint32_t wp_index =
	reg_ctx->SetHardwareWatchpoint (addr, size, watch_flags);
	if (wp_index == LLDB_INVALID_INDEX32)
	return Error ("Setting hardware watchpoint failed.");
	m_watchpoint_index_map.insert({addr, wp_index});
	return Error ();
	}

	Error
	NativeThreadLinux::RemoveWatchpoint (lldb::addr_t addr)
	{
	auto wp = m_watchpoint_index_map.find(addr);
	if (wp == m_watchpoint_index_map.end())
	return Error ();
	uint32_t wp_index = wp->second;
	m_watchpoint_index_map.erase(wp);
	if (GetRegisterContext()->ClearHardwareWatchpoint(wp_index))
	return Error ();
	return Error ("Clearing hardware watchpoint failed.");
	}

	void
	NativeThreadLinux::SetLaunching ()
	{
	const StateType new_state = StateType::eStateLaunching;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	// Also mark it as stopped since launching temporarily stops the newly created thread
	// in the ptrace machinery.
	m_stop_info.reason = StopReason::eStopReasonSignal;
	m_stop_info.details.signal.signo = SIGSTOP;
	}


	void
	NativeThreadLinux::SetRunning ()
	{
	const StateType new_state = StateType::eStateRunning;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonNone;
	m_stop_description.clear();

	// If watchpoints have been set, but none on this thread,
	// then this is a new thread. So set all existing watchpoints.
	if (m_watchpoint_index_map.empty())
	{
	const auto process_sp = GetProcess();
	if (process_sp)
	{
	const auto &watchpoint_map = process_sp->GetWatchpointMap();
	if (watchpoint_map.empty()) return;
	GetRegisterContext()->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);
	}
	}
	}
	}

	void
	NativeThreadLinux::SetStepping ()
	{
	const StateType new_state = StateType::eStateStepping;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonNone;
	}

	void
	NativeThreadLinux::SetStoppedBySignal (uint32_t signo)
	{
	Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
	if (log)
	log->Printf ("NativeThreadLinux::%s called with signal 0x%02" PRIx32, __FUNCTION__, signo);

	const StateType new_state = StateType::eStateStopped;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonSignal;
	m_stop_info.details.signal.signo = signo;
	}

	bool
	NativeThreadLinux::IsStopped (int *signo)
	{
	if (!StateIsStoppedState (m_state, false))
	return false;

	// If we are stopped by a signal, return the signo.
	if (signo &&
	m_state == StateType::eStateStopped &&
	m_stop_info.reason == StopReason::eStopReasonSignal)
	{
	*signo = m_stop_info.details.signal.signo;
	}

	// Regardless, we are stopped.
	return true;
	}


	void
	NativeThreadLinux::SetStoppedByExec ()
	{
	Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
	if (log)
	log->Printf ("NativeThreadLinux::%s()", __FUNCTION__);

	const StateType new_state = StateType::eStateStopped;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonExec;
	m_stop_info.details.signal.signo = SIGSTOP;
	}

	void
	NativeThreadLinux::SetStoppedByBreakpoint ()
	{
	const StateType new_state = StateType::eStateStopped;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonBreakpoint;
	m_stop_info.details.signal.signo = SIGTRAP;
	m_stop_description.clear();
	}

	void
	NativeThreadLinux::SetStoppedByWatchpoint ()
	{
	Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
	lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
	if (log)
	{
	NativeProcessProtocolSP process_sp = m_process_wp.lock ();
	if (process_sp)
	pid = process_sp->GetID ();
	}

	const StateType new_state = StateType::eStateStopped;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	NativeRegisterContextSP reg_ctx = GetRegisterContext ();
	const uint32_t num_hw_watchpoints = reg_ctx->NumSupportedHardwareWatchpoints ();

	m_stop_description.clear ();
	for (uint32_t wp_index = 0; wp_index < num_hw_watchpoints; ++wp_index)
	{
	if (reg_ctx->IsWatchpointHit (wp_index).Success())
	{
	if (log)
	log->Printf ("NativeThreadLinux:%s (pid=%" PRIu64 ", tid=%" PRIu64 ") watchpoint found with idx: %u",
	__FUNCTION__, pid, GetID (), wp_index);

	std::ostringstream ostr;
	ostr << reg_ctx->GetWatchpointAddress (wp_index) << " " << wp_index;
	m_stop_description = ostr.str();

	m_stop_info.reason = StopReason::eStopReasonWatchpoint;
	m_stop_info.details.signal.signo = SIGTRAP;
	return;
	}
	}

	// The process reported a watchpoint was hit, but we haven't found the
	// watchpoint. Assume that a stopped by trace is reported as a hardware
	// watchpoint what happens on some linux kernels (e.g.: android-arm64
	// platfrom-21).

	if (log)
	log->Printf ("NativeThreadLinux:%s (pid=%" PRIu64 ", tid=%" PRIu64 ") none of the watchpoint was hit.",
	__FUNCTION__, pid, GetID ());

	SetStoppedByTrace ();
	}

	bool
	NativeThreadLinux::IsStoppedAtBreakpoint ()
	{
	return GetState () == StateType::eStateStopped &&
	m_stop_info.reason == StopReason::eStopReasonBreakpoint;
	}

	bool
	NativeThreadLinux::IsStoppedAtWatchpoint ()
	{
	return GetState () == StateType::eStateStopped &&
	m_stop_info.reason == StopReason::eStopReasonWatchpoint;
	}

	void
	NativeThreadLinux::SetStoppedByTrace ()
	{
	const StateType new_state = StateType::eStateStopped;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonTrace;
	m_stop_info.details.signal.signo = SIGTRAP;
	}

	void
	NativeThreadLinux::SetCrashedWithException (const siginfo_t& info)
	{
	const StateType new_state = StateType::eStateCrashed;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonException;
	m_stop_info.details.signal.signo = info.si_signo;

	const auto reason = GetCrashReason (info);
	m_stop_description = GetCrashReasonString (reason, reinterpret_cast<lldb::addr_t> (info.si_addr));
	}

	void
	NativeThreadLinux::SetSuspended ()
	{
	const StateType new_state = StateType::eStateSuspended;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	// FIXME what makes sense here? Do we need a suspended StopReason?
	m_stop_info.reason = StopReason::eStopReasonNone;
	}

	void
	NativeThreadLinux::SetExited ()
	{
	const StateType new_state = StateType::eStateExited;
	MaybeLogStateChange (new_state);
	m_state = new_state;

	m_stop_info.reason = StopReason::eStopReasonThreadExiting;
	}

	void
	NativeThreadLinux::MaybeLogStateChange (lldb::StateType new_state)
	{
	Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
	// If we're not logging, we're done.
	if (!log)
	return;

	// If this is a state change to the same state, we're done.
	lldb::StateType old_state = m_state;
	if (new_state == old_state)
	return;

	NativeProcessProtocolSP m_process_sp = m_process_wp.lock ();
	lldb::pid_t pid = m_process_sp ? m_process_sp->GetID () : LLDB_INVALID_PROCESS_ID;

	// Log it.
	log->Printf ("NativeThreadLinux: thread (pid=%" PRIu64 ", tid=%" PRIu64 ") changing from state %s to %s", pid, GetID (), StateAsCString (old_state), StateAsCString (new_state));
	}