llvm-project/lldb/source/Plugins/Process/MacOSX-Kernel/ThreadKDP.cpp

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


#include "ThreadKDP.h"

#include "llvm/Support/MachO.h"

#include "lldb/Core/ArchSpec.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Core/State.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Unwind.h"
#include "lldb/Breakpoint/Watchpoint.h"

#include "ProcessKDP.h"
#include "ProcessKDPLog.h"
#include "RegisterContextKDP_arm.h"
#include "RegisterContextKDP_i386.h"
#include "RegisterContextKDP_x86_64.h"

using namespace lldb;
using namespace lldb_private;

//----------------------------------------------------------------------
// Thread Registers
//----------------------------------------------------------------------

ThreadKDP::ThreadKDP (const lldb::ProcessSP &process_sp, lldb::tid_t tid) :
    Thread(process_sp, tid),
    m_thread_name (),
    m_dispatch_queue_name (),
    m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS)
{
    ProcessKDPLog::LogIf(KDP_LOG_THREAD, "%p: ThreadKDP::ThreadKDP (tid = 0x%4.4x)", this, GetID());
}

ThreadKDP::~ThreadKDP ()
{
    ProcessKDPLog::LogIf(KDP_LOG_THREAD, "%p: ThreadKDP::~ThreadKDP (tid = 0x%4.4x)", this, GetID());
    DestroyThread();
}

const char *
ThreadKDP::GetName ()
{
    if (m_thread_name.empty())
        return NULL;
    return m_thread_name.c_str();
}

const char *
ThreadKDP::GetQueueName ()
{
    return NULL;
}

bool
ThreadKDP::WillResume (StateType resume_state)
{
    ClearStackFrames();
    // Call the Thread::WillResume first. If we stop at a signal, the stop info
    // class for signal will set the resume signal that we need below. The signal
    // stuff obeys the Process::UnixSignal defaults. 
    Thread::WillResume(resume_state);

    lldb::LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_STEP));
    if (log)
        log->Printf ("Resuming thread: %4.4llx with state: %s.", GetID(), StateAsCString(resume_state));

//    ProcessKDP &process = GetKDPProcess();
//    switch (resume_state)
//    {
//    case eStateSuspended:
//    case eStateStopped:
//        // Don't append anything for threads that should stay stopped.
//        break;
//
//    case eStateRunning:
//    case eStateStepping:
//        break;
//
//    default:
//        break;
//    }
    return true;
}

void
ThreadKDP::RefreshStateAfterStop()
{
    // Invalidate all registers in our register context. We don't set "force" to
    // true because the stop reply packet might have had some register values
    // that were expedited and these will already be copied into the register
    // context by the time this function gets called. The KDPRegisterContext
    // class has been made smart enough to detect when it needs to invalidate
    // which registers are valid by putting hooks in the register read and 
    // register supply functions where they check the process stop ID and do
    // the right thing.
    const bool force = false;
    GetRegisterContext()->InvalidateIfNeeded (force);
}

void
ThreadKDP::ClearStackFrames ()
{
    Unwind *unwinder = GetUnwinder ();
    if (unwinder)
        unwinder->Clear();
    Thread::ClearStackFrames();
}


bool
ThreadKDP::ThreadIDIsValid (lldb::tid_t thread)
{
    return thread != 0;
}

void
ThreadKDP::Dump(Log *log, uint32_t index)
{
}


bool
ThreadKDP::ShouldStop (bool &step_more)
{
    return true;
}
lldb::RegisterContextSP
ThreadKDP::GetRegisterContext ()
{
    if (m_reg_context_sp.get() == NULL)
        m_reg_context_sp = CreateRegisterContextForFrame (NULL);
    return m_reg_context_sp;
}

lldb::RegisterContextSP
ThreadKDP::CreateRegisterContextForFrame (StackFrame *frame)
{
    lldb::RegisterContextSP reg_ctx_sp;
    uint32_t concrete_frame_idx = 0;
    
    if (frame)
        concrete_frame_idx = frame->GetConcreteFrameIndex ();

    if (concrete_frame_idx == 0)
    {
        ProcessSP process_sp (CalculateProcess());
        if (process_sp)
        {
            switch (static_cast<ProcessKDP *>(process_sp.get())->GetCommunication().GetCPUType())
            {
                case llvm::MachO::CPUTypeARM:
                    reg_ctx_sp.reset (new RegisterContextKDP_arm (*this, concrete_frame_idx));
                    break;
                case llvm::MachO::CPUTypeI386:
                    reg_ctx_sp.reset (new RegisterContextKDP_i386 (*this, concrete_frame_idx));
                    break;
                case llvm::MachO::CPUTypeX86_64:
                    reg_ctx_sp.reset (new RegisterContextKDP_x86_64 (*this, concrete_frame_idx));
                    break;
                default:
                    assert (!"Add CPU type support in KDP");
                    break;
            }
        }
    }
    else if (m_unwinder_ap.get())
        reg_ctx_sp = m_unwinder_ap->CreateRegisterContextForFrame (frame);
    return reg_ctx_sp;
}

lldb::StopInfoSP
ThreadKDP::GetPrivateStopReason ()
{
    ProcessSP process_sp (GetProcess());
    if (process_sp)
    {
        const uint32_t process_stop_id = process_sp->GetStopID();
        if (m_thread_stop_reason_stop_id != process_stop_id ||
            (m_actual_stop_info_sp && !m_actual_stop_info_sp->IsValid()))
        {
            // TODO: can we query the initial state of the thread here?
            // For now I am just going to pretend that a SIGSTOP happened.

            SetStopInfo(StopInfo::CreateStopReasonWithSignal (*this, SIGSTOP));

            // If GetKDPProcess().SetThreadStopInfo() doesn't find a stop reason
            // for this thread, then m_actual_stop_info_sp will not ever contain
            // a valid stop reason and the "m_actual_stop_info_sp->IsValid() == false"
            // check will never be able to tell us if we have the correct stop info
            // for this thread and we will continually send qThreadStopInfo packets
            // down to the remote KDP server, so we need to keep our own notion
            // of the stop ID that m_actual_stop_info_sp is valid for (even if it
            // contains nothing). We use m_thread_stop_reason_stop_id for this below.
    //        m_thread_stop_reason_stop_id = process_stop_id;
    //        m_actual_stop_info_sp.reset();

        }
    }
    return m_actual_stop_info_sp;
}