source/Plugins/Process/POSIX/POSIXThread.cpp

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

#include "lldb/lldb-python.h"

// C Includes
#include <errno.h>

// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Breakpoint/Watchpoint.h"
#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/State.h"
#include "lldb/Host/Host.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadSpec.h"
#include "POSIXStopInfo.h"
#include "POSIXThread.h"
#include "ProcessPOSIX.h"
#include "ProcessPOSIXLog.h"
#include "ProcessMonitor.h"
#include "RegisterContext_i386.h"
#include "RegisterContext_x86_64.h"
#include "RegisterContextPOSIX.h"
#include "RegisterContextLinux_x86_64.h"
#include "RegisterContextFreeBSD_x86_64.h"

#include "UnwindLLDB.h"

using namespace lldb;
using namespace lldb_private;


POSIXThread::POSIXThread(Process &process, lldb::tid_t tid)
    : Thread(process, tid),
      m_frame_ap (),
      m_breakpoint (),
      m_thread_name ()
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
        log->Printf ("POSIXThread::%s (tid = %" PRIi64 ")", __FUNCTION__, tid);

    // Set the current watchpoints for this thread.
    Target &target = GetProcess()->GetTarget();
    const WatchpointList &wp_list = target.GetWatchpointList();
    size_t wp_size = wp_list.GetSize();

    for (uint32_t wp_idx = 0; wp_idx < wp_size; wp_idx++)
    {
        lldb::WatchpointSP wp = wp_list.GetByIndex(wp_idx);
        if (wp.get() && wp->IsEnabled())
        {
            assert(EnableHardwareWatchpoint(wp.get()));
        }
    }
}

POSIXThread::~POSIXThread()
{
    DestroyThread();
}

ProcessMonitor &
POSIXThread::GetMonitor()
{
    ProcessSP base = GetProcess();
    ProcessPOSIX &process = static_cast<ProcessPOSIX&>(*base);
    return process.GetMonitor();
}

void
POSIXThread::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.
    //if (StateIsStoppedState(GetState())
    {
        const bool force = false;
        GetRegisterContext()->InvalidateIfNeeded (force);
    }
    // FIXME: This should probably happen somewhere else.
    SetResumeState(eStateRunning);
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log)
        log->Printf ("POSIXThread::%s (tid = %" PRIi64 ") setting thread resume state to running", __FUNCTION__, GetID());
}

const char *
POSIXThread::GetInfo()
{
    return NULL;
}

void
POSIXThread::SetName (const char *name)
{
    if (name && name[0])
        m_thread_name.assign (name);
    else
        m_thread_name.clear();
}

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

lldb::RegisterContextSP
POSIXThread::GetRegisterContext()
{
    if (!m_reg_context_sp)
    {
        ArchSpec arch = Host::GetArchitecture();

        switch (arch.GetCore())
        {
        default:
            assert(false && "CPU type not supported!");
            break;

        case ArchSpec::eCore_x86_32_i386:
        case ArchSpec::eCore_x86_32_i486:
        case ArchSpec::eCore_x86_32_i486sx:
            m_reg_context_sp.reset(new RegisterContext_i386(*this, 0));
            break;

        case ArchSpec::eCore_x86_64_x86_64:
            switch (arch.GetTriple().getOS())
            {
                case llvm::Triple::FreeBSD:
                    m_reg_context_sp.reset(new RegisterContextFreeBSD_x86_64(*this, 0));
                    break;
                case llvm::Triple::Linux:
                    m_reg_context_sp.reset(new RegisterContextLinux_x86_64(*this, 0));
                    break;
                default:
                    assert(false && "OS not supported");
                    break;
            }
            break;
        }
    }
    return m_reg_context_sp;
}

lldb::RegisterContextSP
POSIXThread::CreateRegisterContextForFrame(lldb_private::StackFrame *frame)
{
    lldb::RegisterContextSP reg_ctx_sp;
    uint32_t concrete_frame_idx = 0;

    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
        log->Printf ("POSIXThread::%s ()", __FUNCTION__);

    if (frame)
        concrete_frame_idx = frame->GetConcreteFrameIndex();

    if (concrete_frame_idx == 0)
        reg_ctx_sp = GetRegisterContext();
    else
    {
        assert(GetUnwinder());
        reg_ctx_sp = GetUnwinder()->CreateRegisterContextForFrame(frame);
    }

    return reg_ctx_sp;
}

bool
POSIXThread::CalculateStopInfo()
{
    SetStopInfo (m_stop_info_sp);
    return true;
}

Unwind *
POSIXThread::GetUnwinder()
{
    if (m_unwinder_ap.get() == NULL)
        m_unwinder_ap.reset(new UnwindLLDB(*this));

    return m_unwinder_ap.get();
}

void
POSIXThread::WillResume(lldb::StateType resume_state)
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log)
        log->Printf ("POSIXThread::%s (tid = %" PRIi64 ") setting thread resume state to %s", __FUNCTION__, GetID(), StateAsCString(resume_state));
    // TODO: the line below shouldn't really be done, but
    // the POSIXThread might rely on this so I will leave this in for now
    SetResumeState(resume_state);
}

void
POSIXThread::DidStop()
{
    // Don't set the thread state to stopped unless we really stopped.
}

bool
POSIXThread::Resume()
{
    lldb::StateType resume_state = GetResumeState();
    ProcessMonitor &monitor = GetMonitor();
    bool status;

    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log)
        log->Printf ("POSIXThread::%s (), resume_state = %s", __FUNCTION__,
                         StateAsCString(resume_state));

    switch (resume_state)
    {
    default:
        assert(false && "Unexpected state for resume!");
        status = false;
        break;

    case lldb::eStateRunning:
        SetState(resume_state);
        status = monitor.Resume(GetID(), GetResumeSignal());
        break;

    case lldb::eStateStepping:
        SetState(resume_state);
        status = monitor.SingleStep(GetID(), GetResumeSignal());
        break;
    case lldb::eStateStopped:
    case lldb::eStateSuspended:
        status = true;
        break;
    }

    return status;
}

void
POSIXThread::Notify(const ProcessMessage &message)
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log)
        log->Printf ("POSIXThread::%s () message kind = '%s' for tid %" PRIu64,
                     __FUNCTION__, message.PrintKind(), GetID());

    switch (message.GetKind())
    {
    default:
        assert(false && "Unexpected message kind!");
        break;

    case ProcessMessage::eExitMessage:
        // Nothing to be done.
        break;

    case ProcessMessage::eLimboMessage:
        LimboNotify(message);
        break;

    case ProcessMessage::eSignalMessage:
        SignalNotify(message);
        break;

    case ProcessMessage::eSignalDeliveredMessage:
        SignalDeliveredNotify(message);
        break;

    case ProcessMessage::eTraceMessage:
        TraceNotify(message);
        break;

    case ProcessMessage::eBreakpointMessage:
        BreakNotify(message);
        break;

    case ProcessMessage::eWatchpointMessage:
        WatchNotify(message);
        break;

    case ProcessMessage::eCrashMessage:
        CrashNotify(message);
        break;

    case ProcessMessage::eNewThreadMessage:
        ThreadNotify(message);
        break;
    }
}

bool
POSIXThread::EnableHardwareWatchpoint(Watchpoint *wp)
{
    bool wp_set = false;
    if (wp)
    {
        addr_t wp_addr = wp->GetLoadAddress();
        size_t wp_size = wp->GetByteSize();
        bool wp_read = wp->WatchpointRead();
        bool wp_write = wp->WatchpointWrite();
        uint32_t wp_hw_index = wp->GetHardwareIndex();
        RegisterContextPOSIX* reg_ctx = GetRegisterContextPOSIX();
        if (reg_ctx)
            wp_set = reg_ctx->SetHardwareWatchpointWithIndex(wp_addr, wp_size,
                                                             wp_read, wp_write,
                                                             wp_hw_index);
    }
    return wp_set;
}

bool
POSIXThread::DisableHardwareWatchpoint(Watchpoint *wp)
{
    bool result = false;
    if (wp)
    {
        lldb::RegisterContextSP reg_ctx_sp = GetRegisterContext();
        if (reg_ctx_sp.get())
            result = reg_ctx_sp->ClearHardwareWatchpoint(wp->GetHardwareIndex());
    }
    return result;
}

uint32_t
POSIXThread::NumSupportedHardwareWatchpoints()
{
    lldb::RegisterContextSP reg_ctx_sp = GetRegisterContext();
    if (reg_ctx_sp.get())
        return reg_ctx_sp->NumSupportedHardwareWatchpoints();
    return 0;
}

uint32_t
POSIXThread::FindVacantWatchpointIndex()
{
    uint32_t hw_index = LLDB_INVALID_INDEX32;
    uint32_t num_hw_wps = NumSupportedHardwareWatchpoints();
    uint32_t wp_idx;
    RegisterContextPOSIX* reg_ctx = GetRegisterContextPOSIX();
    if (reg_ctx)
    {
        for (wp_idx = 0; wp_idx < num_hw_wps; wp_idx++)
        {
            if (reg_ctx->IsWatchpointVacant(wp_idx))
            {
                hw_index = wp_idx;
                break;
            }
        }
    }
    return hw_index;
}

void
POSIXThread::BreakNotify(const ProcessMessage &message)
{
    bool status;
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));

    assert(GetRegisterContext());
    status = GetRegisterContextPOSIX()->UpdateAfterBreakpoint();
    assert(status && "Breakpoint update failed!");

    // With our register state restored, resolve the breakpoint object
    // corresponding to our current PC.
    assert(GetRegisterContext());
    lldb::addr_t pc = GetRegisterContext()->GetPC();
    if (log)
        log->Printf ("POSIXThread::%s () PC=0x%8.8" PRIx64, __FUNCTION__, pc);
    lldb::BreakpointSiteSP bp_site(GetProcess()->GetBreakpointSiteList().FindByAddress(pc));

    // If the breakpoint is for this thread, then we'll report the hit, but if it is for another thread,
    // we can just report no reason.  We don't need to worry about stepping over the breakpoint here, that
    // will be taken care of when the thread resumes and notices that there's a breakpoint under the pc.
    if (bp_site && bp_site->ValidForThisThread(this))
    {
        lldb::break_id_t bp_id = bp_site->GetID();
        if (GetProcess()->GetThreadList().SetSelectedThreadByID(GetID()))
            SetStopInfo (StopInfo::CreateStopReasonWithBreakpointSiteID(*this, bp_id));
        else
            assert(false && "Invalid thread ID during BreakNotify.");
    }
    else
    {
        const ThreadSpec *spec = bp_site ? 
            bp_site->GetOwnerAtIndex(0)->GetOptionsNoCreate()->GetThreadSpecNoCreate() : 0;

        if (spec && spec->TIDMatches(*this))
            assert(false && "BreakpointSite is invalid for the current ThreadSpec.");
        else
        {
            if (!m_stop_info_sp) {
                StopInfoSP invalid_stop_info_sp;
                SetStopInfo (invalid_stop_info_sp);
            }
        }
    }
}

void
POSIXThread::WatchNotify(const ProcessMessage &message)
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));

    lldb::addr_t halt_addr = message.GetHWAddress();
    if (log)
        log->Printf ("POSIXThread::%s () Hardware Watchpoint Address = 0x%8.8"
                     PRIx64, __FUNCTION__, halt_addr);

    RegisterContextPOSIX* reg_ctx = GetRegisterContextPOSIX();
    if (reg_ctx)
    {
        uint32_t num_hw_wps = reg_ctx->NumSupportedHardwareWatchpoints();
        uint32_t wp_idx;
        for (wp_idx = 0; wp_idx < num_hw_wps; wp_idx++)
        {
            if (reg_ctx->IsWatchpointHit(wp_idx))
            {
                // Clear the watchpoint hit here
                reg_ctx->ClearWatchpointHits();
                break;
            }
        }

        if (wp_idx == num_hw_wps)
            return;

        Target &target = GetProcess()->GetTarget();
        lldb::addr_t wp_monitor_addr = reg_ctx->GetWatchpointAddress(wp_idx);
        const WatchpointList &wp_list = target.GetWatchpointList();
        lldb::WatchpointSP wp_sp = wp_list.FindByAddress(wp_monitor_addr);

        assert(wp_sp.get() && "No watchpoint found");
        SetStopInfo (StopInfo::CreateStopReasonWithWatchpointID(*this,
                                                                wp_sp->GetID()));
    }
}

void
POSIXThread::TraceNotify(const ProcessMessage &message)
{
#ifndef __FreeBSD__
    RegisterContextPOSIX* reg_ctx = GetRegisterContextPOSIX();
    if (reg_ctx)
    {
        uint32_t num_hw_wps = reg_ctx->NumSupportedHardwareWatchpoints();
        uint32_t wp_idx;
        for (wp_idx = 0; wp_idx < num_hw_wps; wp_idx++)
        {
            if (reg_ctx->IsWatchpointHit(wp_idx))
            {
                WatchNotify(message);
                return;
            }
        }
    }
#endif
    SetStopInfo (StopInfo::CreateStopReasonToTrace(*this));
}

void
POSIXThread::LimboNotify(const ProcessMessage &message)
{
    SetStopInfo (lldb::StopInfoSP(new POSIXLimboStopInfo(*this)));
}

void
POSIXThread::SignalNotify(const ProcessMessage &message)
{
    int signo = message.GetSignal();

    SetStopInfo (StopInfo::CreateStopReasonWithSignal(*this, signo));
    SetResumeSignal(signo);
}

void
POSIXThread::SignalDeliveredNotify(const ProcessMessage &message)
{
    int signo = message.GetSignal();

    SetStopInfo (StopInfo::CreateStopReasonWithSignal(*this, signo));
    SetResumeSignal(signo);
}

void
POSIXThread::CrashNotify(const ProcessMessage &message)
{
    // FIXME: Update stop reason as per bugzilla 14598
    int signo = message.GetSignal();

    assert(message.GetKind() == ProcessMessage::eCrashMessage);

    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log)
        log->Printf ("POSIXThread::%s () signo = %i, reason = '%s'",
                     __FUNCTION__, signo, message.PrintCrashReason());

    SetStopInfo (lldb::StopInfoSP(new POSIXCrashStopInfo(*this, signo,
                                                         message.GetCrashReason(),
                                                         message.GetFaultAddress())));
    SetResumeSignal(signo);
}

void
POSIXThread::ThreadNotify(const ProcessMessage &message)
{
    SetStopInfo (lldb::StopInfoSP(new POSIXNewThreadStopInfo(*this)));
}

unsigned
POSIXThread::GetRegisterIndexFromOffset(unsigned offset)
{
    unsigned reg = LLDB_INVALID_REGNUM;
    ArchSpec arch = Host::GetArchitecture();

    switch (arch.GetCore())
    {
    default:
        llvm_unreachable("CPU type not supported!");
        break;

    case ArchSpec::eCore_x86_32_i386:
    case ArchSpec::eCore_x86_32_i486:
    case ArchSpec::eCore_x86_32_i486sx:
    case ArchSpec::eCore_x86_64_x86_64:
        {
            RegisterContextSP base = GetRegisterContext();
            if (base) {
                RegisterContextPOSIX &context = static_cast<RegisterContextPOSIX &>(*base);
                reg = context.GetRegisterIndexFromOffset(offset);
            }
        }
        break;
    }
    return reg;
}

const char *
POSIXThread::GetRegisterName(unsigned reg)
{
    const char * name = nullptr;
    ArchSpec arch = Host::GetArchitecture();

    switch (arch.GetCore())
    {
    default:
        assert(false && "CPU type not supported!");
        break;

    case ArchSpec::eCore_x86_32_i386:
    case ArchSpec::eCore_x86_32_i486:
    case ArchSpec::eCore_x86_32_i486sx:
    case ArchSpec::eCore_x86_64_x86_64:
        name = GetRegisterContext()->GetRegisterName(reg);
        break;
    }
    return name;
}

const char *
POSIXThread::GetRegisterNameFromOffset(unsigned offset)
{
    return GetRegisterName(GetRegisterIndexFromOffset(offset));
}