llvm-project/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp

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


#include "ThreadGDBRemote.h"

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

#include "ProcessGDBRemote.h"
#include "ProcessGDBRemoteLog.h"
#include "Utility/StringExtractorGDBRemote.h"

using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::process_gdb_remote;

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

ThreadGDBRemote::ThreadGDBRemote (Process &process, lldb::tid_t tid) :
    Thread(process, tid),
    m_thread_name (),
    m_dispatch_queue_name (),
    m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS),
    m_queue_kind(eQueueKindUnknown),
    m_queue_serial(0)
{
    ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::ThreadGDBRemote (pid = %i, tid = 0x%4.4x)",
                               this, 
                               process.GetID(),
                               GetID());
}

ThreadGDBRemote::~ThreadGDBRemote ()
{
    ProcessSP process_sp(GetProcess());
    ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::~ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", 
                               this, 
                               process_sp ? process_sp->GetID() : LLDB_INVALID_PROCESS_ID, 
                               GetID());
    DestroyThread();
}

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

void
ThreadGDBRemote::ClearQueueInfo ()
{
    m_dispatch_queue_name.clear();
    m_queue_kind = eQueueKindUnknown;
    m_queue_serial = 0;
}

void
ThreadGDBRemote::SetQueueInfo (std::string &&queue_name, QueueKind queue_kind, uint64_t queue_serial)
{
    m_dispatch_queue_name = queue_name;
    m_queue_kind = queue_kind;
    m_queue_serial = queue_serial;
}


const char *
ThreadGDBRemote::GetQueueName ()
{
    // If our cached queue info is valid, then someone called ThreadGDBRemote::SetQueueInfo(...)
    // with valid information that was gleaned from the stop reply packet. In this case we trust
    // that the info is valid in m_dispatch_queue_name without refetching it
    if (CachedQueueInfoIsValid())
    {
        if (m_dispatch_queue_name.empty())
            return nullptr;
        else
            return m_dispatch_queue_name.c_str();
    }
    // Always re-fetch the dispatch queue name since it can change

    if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
    {
        ProcessSP process_sp (GetProcess());
        if (process_sp)
        {
            SystemRuntime *runtime = process_sp->GetSystemRuntime ();
            if (runtime)
                m_dispatch_queue_name = runtime->GetQueueNameFromThreadQAddress (m_thread_dispatch_qaddr);
            else
                m_dispatch_queue_name.clear();

            if (!m_dispatch_queue_name.empty())
                return m_dispatch_queue_name.c_str();
        }
    }
    return NULL;
}

queue_id_t
ThreadGDBRemote::GetQueueID ()
{
    // If our cached queue info is valid, then someone called ThreadGDBRemote::SetQueueInfo(...)
    // with valid information that was gleaned from the stop reply packet. In this case we trust
    // that the info is valid in m_dispatch_queue_name without refetching it
    if (CachedQueueInfoIsValid())
        return m_queue_serial;

    if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
    {
        ProcessSP process_sp (GetProcess());
        if (process_sp)
        {
            SystemRuntime *runtime = process_sp->GetSystemRuntime ();
            if (runtime)
            {
                return runtime->GetQueueIDFromThreadQAddress (m_thread_dispatch_qaddr);
            }
        }
    }
    return LLDB_INVALID_QUEUE_ID;
}

QueueSP
ThreadGDBRemote::GetQueue ()
{
    queue_id_t queue_id = GetQueueID();
    QueueSP queue;
    if (queue_id != LLDB_INVALID_QUEUE_ID)
    {
        ProcessSP process_sp (GetProcess());
        if (process_sp)
        {
            queue = process_sp->GetQueueList().FindQueueByID (queue_id);
        }
    }
    return queue;
}

addr_t
ThreadGDBRemote::GetQueueLibdispatchQueueAddress ()
{
    addr_t dispatch_queue_t_addr = LLDB_INVALID_ADDRESS;
    if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
    {
        ProcessSP process_sp (GetProcess());
        if (process_sp)
        {
            SystemRuntime *runtime = process_sp->GetSystemRuntime ();
            if (runtime)
            {
                dispatch_queue_t_addr = runtime->GetLibdispatchQueueAddressFromThreadQAddress (m_thread_dispatch_qaddr);
            }
        }
    }
    return dispatch_queue_t_addr;
}

StructuredData::ObjectSP
ThreadGDBRemote::FetchThreadExtendedInfo ()
{
    StructuredData::ObjectSP object_sp;
    const lldb::user_id_t tid = GetProtocolID();
    Log *log(GetLogIfAnyCategoriesSet (GDBR_LOG_THREAD));
    if (log)
        log->Printf ("Fetching extended information for thread %4.4" PRIx64, tid);
    ProcessSP process_sp (GetProcess());
    if (process_sp)
    {
        ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
        object_sp = gdb_process->GetExtendedInfoForThread (tid);
    }
    return object_sp;
}

void
ThreadGDBRemote::WillResume (StateType resume_state)
{
    int signo = GetResumeSignal();
    const lldb::user_id_t tid = GetProtocolID();
    Log *log(GetLogIfAnyCategoriesSet (GDBR_LOG_THREAD));
    if (log)
        log->Printf ("Resuming thread: %4.4" PRIx64 " with state: %s.", tid, StateAsCString(resume_state));

    ProcessSP process_sp (GetProcess());
    if (process_sp)
    {
        ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
        switch (resume_state)
        {
        case eStateSuspended:
        case eStateStopped:
            // Don't append anything for threads that should stay stopped.
            break;

        case eStateRunning:
            if (gdb_process->GetUnixSignals()->SignalIsValid(signo))
                gdb_process->m_continue_C_tids.push_back(std::make_pair(tid, signo));
            else
                gdb_process->m_continue_c_tids.push_back(tid);
            break;

        case eStateStepping:
            if (gdb_process->GetUnixSignals()->SignalIsValid(signo))
                gdb_process->m_continue_S_tids.push_back(std::make_pair(tid, signo));
            else
                gdb_process->m_continue_s_tids.push_back(tid);
            break;

        default:
            break;
        }
    }
}

void
ThreadGDBRemote::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 GDBRemoteRegisterContext
    // 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);
}

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

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


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

lldb::RegisterContextSP
ThreadGDBRemote::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 (GetProcess());
        if (process_sp)
        {
            ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
            // read_all_registers_at_once will be true if 'p' packet is not supported.
            bool read_all_registers_at_once = !gdb_process->GetGDBRemote().GetpPacketSupported (GetID());
            reg_ctx_sp.reset (new GDBRemoteRegisterContext (*this, concrete_frame_idx, gdb_process->m_register_info, read_all_registers_at_once));
        }
    }
    else
    {
        Unwind *unwinder = GetUnwinder ();
        if (unwinder)
            reg_ctx_sp = unwinder->CreateRegisterContextForFrame (frame);
    }
    return reg_ctx_sp;
}

bool
ThreadGDBRemote::PrivateSetRegisterValue (uint32_t reg, StringExtractor &response)
{
    GDBRemoteRegisterContext *gdb_reg_ctx = static_cast<GDBRemoteRegisterContext *>(GetRegisterContext ().get());
    assert (gdb_reg_ctx);
    return gdb_reg_ctx->PrivateSetRegisterValue (reg, response);
}

bool
ThreadGDBRemote::CalculateStopInfo ()
{
    ProcessSP process_sp (GetProcess());
    if (process_sp)
        return static_cast<ProcessGDBRemote *>(process_sp.get())->CalculateThreadStopInfo(this);
    return false;
}