teak-llvm/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
Greg Clayton 0b90be1c4f Implement the "qSymbol" packet in order to be able to read queue information in debugserver and return the info in the stop reply packets.
A "qSymbol::" is sent when shared libraries have been loaded by hooking into the Process::ModulesDidLoad() function from within ProcessGDBRemote. This function was made virtual so that the ProcessGDBRemote version is called, which then first calls the Process::ModulesDidLoad(), and then it queries for any symbol lookups that the remote GDB server might want to do.

This allows debugserver to request the "dispatch_queue_offsets" symbol so that it can read the queue name, queue kind and queue serial number and include this data as part of the stop reply packet. Previously each thread would have to do 3 memory reads in order to read the queue name.

This is part of reducing the number of packets that are sent between LLDB and the remote GDB server.

<rdar://problem/21494354>

llvm-svn: 240466
2015-06-23 21:27:50 +00:00

330 lines
10 KiB
C++

//===-- 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)
{
StringExtractorGDBRemote stop_packet;
ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
if (gdb_process->GetGDBRemote().GetThreadStopInfo(GetProtocolID(), stop_packet))
return gdb_process->SetThreadStopInfo (stop_packet) == eStateStopped;
}
return false;
}