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, "%p: ThreadGDBRemote::ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
47 }
48 
49 ThreadGDBRemote::~ThreadGDBRemote ()
50 {
51     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::~ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
52     DestroyThread();
53 }
54 
55 
56 const char *
57 ThreadGDBRemote::GetInfo ()
58 {
59     return NULL;
60 }
61 
62 
63 const char *
64 ThreadGDBRemote::GetName ()
65 {
66     if (m_thread_name.empty())
67         return NULL;
68     return m_thread_name.c_str();
69 }
70 
71 
72 const char *
73 ThreadGDBRemote::GetQueueName ()
74 {
75     // Always re-fetch the dispatch queue name since it can change
76     if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
77         return GetGDBProcess().GetDispatchQueueNameForThread (m_thread_dispatch_qaddr, m_dispatch_queue_name);
78     return NULL;
79 }
80 
81 bool
82 ThreadGDBRemote::WillResume (StateType resume_state)
83 {
84     ClearStackFrames();
85     // Call the Thread::WillResume first. If we stop at a signal, the stop info
86     // class for signal will set the resume signal that we need below. The signal
87     // stuff obeys the Process::UnixSignal defaults.
88     Thread::WillResume(resume_state);
89 
90     int signo = GetResumeSignal();
91     lldb::LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_STEP));
92     if (log)
93         log->Printf ("Resuming thread: %4.4x with state: %s.", GetID(), StateAsCString(resume_state));
94 
95     ProcessGDBRemote &process = GetGDBProcess();
96     switch (resume_state)
97     {
98     case eStateSuspended:
99     case eStateStopped:
100         // Don't append anything for threads that should stay stopped.
101         break;
102 
103     case eStateRunning:
104         if (m_process.GetUnixSignals().SignalIsValid (signo))
105             process.m_continue_C_tids.push_back(std::make_pair(GetID(), signo));
106         else
107             process.m_continue_c_tids.push_back(GetID());
108         break;
109 
110     case eStateStepping:
111         if (m_process.GetUnixSignals().SignalIsValid (signo))
112             process.m_continue_S_tids.push_back(std::make_pair(GetID(), signo));
113         else
114             process.m_continue_s_tids.push_back(GetID());
115         break;
116 
117     default:
118         break;
119     }
120     return true;
121 }
122 
123 void
124 ThreadGDBRemote::RefreshStateAfterStop()
125 {
126     // Invalidate all registers in our register context. We don't set "force" to
127     // true because the stop reply packet might have had some register values
128     // that were expedited and these will already be copied into the register
129     // context by the time this function gets called. The GDBRemoteRegisterContext
130     // class has been made smart enough to detect when it needs to invalidate
131     // which registers are valid by putting hooks in the register read and
132     // register supply functions where they check the process stop ID and do
133     // the right thing.
134     const bool force = false;
135     GetRegisterContext()->InvalidateIfNeeded (force);
136 }
137 
138 Unwind *
139 ThreadGDBRemote::GetUnwinder ()
140 {
141     if (m_unwinder_ap.get() == NULL)
142     {
143         const ArchSpec target_arch (GetProcess().GetTarget().GetArchitecture ());
144         const llvm::Triple::ArchType machine = target_arch.GetMachine();
145         switch (machine)
146         {
147             case llvm::Triple::x86_64:
148             case llvm::Triple::x86:
149             case llvm::Triple::arm:
150             case llvm::Triple::thumb:
151                 m_unwinder_ap.reset (new UnwindLLDB (*this));
152                 break;
153 
154             default:
155 #if defined(__APPLE__)
156                 m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
157 #endif
158                 break;
159         }
160     }
161     return m_unwinder_ap.get();
162 }
163 
164 void
165 ThreadGDBRemote::ClearStackFrames ()
166 {
167     Unwind *unwinder = GetUnwinder ();
168     if (unwinder)
169         unwinder->Clear();
170     Thread::ClearStackFrames();
171 }
172 
173 
174 bool
175 ThreadGDBRemote::ThreadIDIsValid (lldb::tid_t thread)
176 {
177     return thread != 0;
178 }
179 
180 void
181 ThreadGDBRemote::Dump(Log *log, uint32_t index)
182 {
183 }
184 
185 
186 bool
187 ThreadGDBRemote::ShouldStop (bool &step_more)
188 {
189     return true;
190 }
191 lldb::RegisterContextSP
192 ThreadGDBRemote::GetRegisterContext ()
193 {
194     if (m_reg_context_sp.get() == NULL)
195         m_reg_context_sp = CreateRegisterContextForFrame (NULL);
196     return m_reg_context_sp;
197 }
198 
199 lldb::RegisterContextSP
200 ThreadGDBRemote::CreateRegisterContextForFrame (StackFrame *frame)
201 {
202     lldb::RegisterContextSP reg_ctx_sp;
203     const bool read_all_registers_at_once = false;
204     uint32_t concrete_frame_idx = 0;
205 
206     if (frame)
207         concrete_frame_idx = frame->GetConcreteFrameIndex ();
208 
209     if (concrete_frame_idx == 0)
210         reg_ctx_sp.reset (new GDBRemoteRegisterContext (*this, concrete_frame_idx, GetGDBProcess().m_register_info, read_all_registers_at_once));
211     else if (m_unwinder_ap.get())
212         reg_ctx_sp = m_unwinder_ap->CreateRegisterContextForFrame (frame);
213     return reg_ctx_sp;
214 }
215 
216 bool
217 ThreadGDBRemote::PrivateSetRegisterValue (uint32_t reg, StringExtractor &response)
218 {
219     GDBRemoteRegisterContext *gdb_reg_ctx = static_cast<GDBRemoteRegisterContext *>(GetRegisterContext ().get());
220     assert (gdb_reg_ctx);
221     return gdb_reg_ctx->PrivateSetRegisterValue (reg, response);
222 }
223 
224 bool
225 ThreadGDBRemote::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
226 {
227     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
228     if (frame_sp)
229     {
230         checkpoint.SetStackID(frame_sp->GetStackID());
231         return frame_sp->GetRegisterContext()->ReadAllRegisterValues (checkpoint.GetData());
232     }
233     return false;
234 }
235 
236 bool
237 ThreadGDBRemote::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
238 {
239     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
240     if (frame_sp)
241     {
242         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (checkpoint.GetData());
243         frame_sp->GetRegisterContext()->InvalidateIfNeeded(true);
244         ClearStackFrames();
245         return ret;
246     }
247     return false;
248 }
249 
250 lldb::StopInfoSP
251 ThreadGDBRemote::GetPrivateStopReason ()
252 {
253     const uint32_t process_stop_id = GetProcess().GetStopID();
254     if (m_thread_stop_reason_stop_id != process_stop_id ||
255         (m_actual_stop_info_sp && !m_actual_stop_info_sp->IsValid()))
256     {
257         // If GetGDBProcess().SetThreadStopInfo() doesn't find a stop reason
258         // for this thread, then m_actual_stop_info_sp will not ever contain
259         // a valid stop reason and the "m_actual_stop_info_sp->IsValid() == false"
260         // check will never be able to tell us if we have the correct stop info
261         // for this thread and we will continually send qThreadStopInfo packets
262         // down to the remote GDB server, so we need to keep our own notion
263         // of the stop ID that m_actual_stop_info_sp is valid for (even if it
264         // contains nothing). We use m_thread_stop_reason_stop_id for this below.
265         m_thread_stop_reason_stop_id = process_stop_id;
266         m_actual_stop_info_sp.reset();
267 
268         StringExtractorGDBRemote stop_packet;
269         ProcessGDBRemote &gdb_process = GetGDBProcess();
270         if (gdb_process.GetGDBRemote().GetThreadStopInfo(GetID(), stop_packet))
271             gdb_process.SetThreadStopInfo (stop_packet);
272     }
273     return m_actual_stop_info_sp;
274 }
275 
276 
277