1 //===-- ThreadGDBRemote.cpp -------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 
11 #include "ThreadGDBRemote.h"
12 
13 #include "lldb/Core/ArchSpec.h"
14 #include "lldb/Core/DataExtractor.h"
15 #include "lldb/Core/StreamString.h"
16 #include "lldb/Core/State.h"
17 #include "lldb/Target/Process.h"
18 #include "lldb/Target/RegisterContext.h"
19 #include "lldb/Target/StopInfo.h"
20 #include "lldb/Target/Target.h"
21 #include "lldb/Target/Unwind.h"
22 #include "lldb/Breakpoint/WatchpointLocation.h"
23 
24 #include "ProcessGDBRemote.h"
25 #include "ProcessGDBRemoteLog.h"
26 #include "Plugins/Process/Utility/UnwindLLDB.h"
27 #include "Utility/StringExtractorGDBRemote.h"
28 
29 #if defined(__APPLE__)
30 #include "UnwindMacOSXFrameBackchain.h"
31 #endif
32 
33 using namespace lldb;
34 using namespace lldb_private;
35 
36 //----------------------------------------------------------------------
37 // Thread Registers
38 //----------------------------------------------------------------------
39 
40 ThreadGDBRemote::ThreadGDBRemote (ProcessGDBRemote &process, lldb::tid_t tid) :
41     Thread(process, tid),
42     m_thread_name (),
43     m_dispatch_queue_name (),
44     m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS)
45 {
46 //    ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD | GDBR_LOG_VERBOSE, "ThreadGDBRemote::ThreadGDBRemote ( pid = %i, tid = 0x%4.4x, )", m_process.GetID(), GetID());
47     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
48 }
49 
50 ThreadGDBRemote::~ThreadGDBRemote ()
51 {
52     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::~ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
53     DestroyThread();
54 }
55 
56 
57 const char *
58 ThreadGDBRemote::GetInfo ()
59 {
60     return NULL;
61 }
62 
63 
64 const char *
65 ThreadGDBRemote::GetName ()
66 {
67     if (m_thread_name.empty())
68         return NULL;
69     return m_thread_name.c_str();
70 }
71 
72 
73 const char *
74 ThreadGDBRemote::GetQueueName ()
75 {
76     // Always re-fetch the dispatch queue name since it can change
77     if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
78         return GetGDBProcess().GetDispatchQueueNameForThread (m_thread_dispatch_qaddr, m_dispatch_queue_name);
79     return NULL;
80 }
81 
82 bool
83 ThreadGDBRemote::WillResume (StateType resume_state)
84 {
85     ClearStackFrames();
86     // Call the Thread::WillResume first. If we stop at a signal, the stop info
87     // class for signal will set the resume signal that we need below. The signal
88     // stuff obeys the Process::UnixSignal defaults.
89     Thread::WillResume(resume_state);
90 
91     int signo = GetResumeSignal();
92     lldb::LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_STEP));
93     if (log)
94         log->Printf ("Resuming thread: %4.4x with state: %s.", GetID(), StateAsCString(resume_state));
95 
96     ProcessGDBRemote &process = GetGDBProcess();
97     switch (resume_state)
98     {
99     case eStateSuspended:
100     case eStateStopped:
101         // Don't append anything for threads that should stay stopped.
102         break;
103 
104     case eStateRunning:
105         if (m_process.GetUnixSignals().SignalIsValid (signo))
106             process.m_continue_C_tids.push_back(std::make_pair(GetID(), signo));
107         else
108             process.m_continue_c_tids.push_back(GetID());
109         break;
110 
111     case eStateStepping:
112         if (m_process.GetUnixSignals().SignalIsValid (signo))
113             process.m_continue_S_tids.push_back(std::make_pair(GetID(), signo));
114         else
115             process.m_continue_s_tids.push_back(GetID());
116         break;
117 
118     default:
119         break;
120     }
121     return true;
122 }
123 
124 void
125 ThreadGDBRemote::RefreshStateAfterStop()
126 {
127     // Invalidate all registers in our register context. We don't set "force" to
128     // true because the stop reply packet might have had some register values
129     // that were expedited and these will already be copied into the register
130     // context by the time this function gets called. The GDBRemoteRegisterContext
131     // class has been made smart enough to detect when it needs to invalidate
132     // which registers are valid by putting hooks in the register read and
133     // register supply functions where they check the process stop ID and do
134     // the right thing.
135     const bool force = false;
136     GetRegisterContext()->InvalidateIfNeeded (force);
137 }
138 
139 Unwind *
140 ThreadGDBRemote::GetUnwinder ()
141 {
142     if (m_unwinder_ap.get() == NULL)
143     {
144         const ArchSpec target_arch (GetProcess().GetTarget().GetArchitecture ());
145         const llvm::Triple::ArchType machine = target_arch.GetMachine();
146         if (machine == llvm::Triple::x86_64 || machine == llvm::Triple::x86)
147         {
148             m_unwinder_ap.reset (new UnwindLLDB (*this));
149         }
150 #if defined(__APPLE__)
151         else
152         {
153             m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
154         }
155 #endif
156     }
157     return m_unwinder_ap.get();
158 }
159 
160 void
161 ThreadGDBRemote::ClearStackFrames ()
162 {
163     Unwind *unwinder = GetUnwinder ();
164     if (unwinder)
165         unwinder->Clear();
166     Thread::ClearStackFrames();
167 }
168 
169 
170 bool
171 ThreadGDBRemote::ThreadIDIsValid (lldb::tid_t thread)
172 {
173     return thread != 0;
174 }
175 
176 void
177 ThreadGDBRemote::Dump(Log *log, uint32_t index)
178 {
179 }
180 
181 
182 bool
183 ThreadGDBRemote::ShouldStop (bool &step_more)
184 {
185     return true;
186 }
187 lldb::RegisterContextSP
188 ThreadGDBRemote::GetRegisterContext ()
189 {
190     if (m_reg_context_sp.get() == NULL)
191         m_reg_context_sp = CreateRegisterContextForFrame (NULL);
192     return m_reg_context_sp;
193 }
194 
195 lldb::RegisterContextSP
196 ThreadGDBRemote::CreateRegisterContextForFrame (StackFrame *frame)
197 {
198     lldb::RegisterContextSP reg_ctx_sp;
199     const bool read_all_registers_at_once = false;
200     uint32_t concrete_frame_idx = 0;
201 
202     if (frame)
203         concrete_frame_idx = frame->GetConcreteFrameIndex ();
204 
205     if (concrete_frame_idx == 0)
206         reg_ctx_sp.reset (new GDBRemoteRegisterContext (*this, concrete_frame_idx, GetGDBProcess().m_register_info, read_all_registers_at_once));
207     else if (m_unwinder_ap.get())
208         reg_ctx_sp = m_unwinder_ap->CreateRegisterContextForFrame (frame);
209     return reg_ctx_sp;
210 }
211 
212 bool
213 ThreadGDBRemote::PrivateSetRegisterValue (uint32_t reg, StringExtractor &response)
214 {
215     GDBRemoteRegisterContext *gdb_reg_ctx = static_cast<GDBRemoteRegisterContext *>(GetRegisterContext ().get());
216     assert (gdb_reg_ctx);
217     return gdb_reg_ctx->PrivateSetRegisterValue (reg, response);
218 }
219 
220 bool
221 ThreadGDBRemote::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
222 {
223     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
224     if (frame_sp)
225     {
226         checkpoint.SetStackID(frame_sp->GetStackID());
227         return frame_sp->GetRegisterContext()->ReadAllRegisterValues (checkpoint.GetData());
228     }
229     return false;
230 }
231 
232 bool
233 ThreadGDBRemote::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
234 {
235     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
236     if (frame_sp)
237     {
238         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (checkpoint.GetData());
239         frame_sp->GetRegisterContext()->InvalidateIfNeeded(true);
240         ClearStackFrames();
241         return ret;
242     }
243     return false;
244 }
245 
246 lldb::StopInfoSP
247 ThreadGDBRemote::GetPrivateStopReason ()
248 {
249     const uint32_t process_stop_id = GetProcess().GetStopID();
250     if (m_thread_stop_reason_stop_id != process_stop_id ||
251         (m_actual_stop_info_sp && !m_actual_stop_info_sp->IsValid()))
252     {
253         // If GetGDBProcess().SetThreadStopInfo() doesn't find a stop reason
254         // for this thread, then m_actual_stop_info_sp will not ever contain
255         // a valid stop reason and the "m_actual_stop_info_sp->IsValid() == false"
256         // check will never be able to tell us if we have the correct stop info
257         // for this thread and we will continually send qThreadStopInfo packets
258         // down to the remote GDB server, so we need to keep our own notion
259         // of the stop ID that m_actual_stop_info_sp is valid for (even if it
260         // contains nothing). We use m_thread_stop_reason_stop_id for this below.
261         m_thread_stop_reason_stop_id = process_stop_id;
262         m_actual_stop_info_sp.reset();
263 
264         StringExtractorGDBRemote stop_packet;
265         ProcessGDBRemote &gdb_process = GetGDBProcess();
266         if (gdb_process.GetGDBRemote().GetThreadStopInfo(GetID(), stop_packet))
267             gdb_process.SetThreadStopInfo (stop_packet);
268     }
269     return m_actual_stop_info_sp;
270 }
271 
272 
273