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/Target/Process.h"
17 #include "lldb/Target/RegisterContext.h"
18 #include "lldb/Target/StopInfo.h"
19 #include "lldb/Target/Target.h"
20 #include "lldb/Target/Unwind.h"
21 #include "lldb/Breakpoint/WatchpointLocation.h"
22 
23 #include "ProcessGDBRemote.h"
24 #include "ProcessGDBRemoteLog.h"
25 #include "Utility/StringExtractorGDBRemote.h"
26 #include "UnwindMacOSXFrameBackchain.h"
27 #include "UnwindLLDB.h"
28 
29 using namespace lldb;
30 using namespace lldb_private;
31 
32 //----------------------------------------------------------------------
33 // Thread Registers
34 //----------------------------------------------------------------------
35 
36 ThreadGDBRemote::ThreadGDBRemote (ProcessGDBRemote &process, lldb::tid_t tid) :
37     Thread(process, tid),
38     m_thread_name (),
39     m_dispatch_queue_name (),
40     m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS)
41 {
42 //    ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD | GDBR_LOG_VERBOSE, "ThreadGDBRemote::ThreadGDBRemote ( pid = %i, tid = 0x%4.4x, )", m_process.GetID(), GetID());
43     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
44 }
45 
46 ThreadGDBRemote::~ThreadGDBRemote ()
47 {
48     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::~ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
49     DestroyThread();
50 }
51 
52 
53 const char *
54 ThreadGDBRemote::GetInfo ()
55 {
56     return NULL;
57 }
58 
59 
60 const char *
61 ThreadGDBRemote::GetName ()
62 {
63     if (m_thread_name.empty())
64         return NULL;
65     return m_thread_name.c_str();
66 }
67 
68 
69 const char *
70 ThreadGDBRemote::GetQueueName ()
71 {
72     // Always re-fetch the dispatch queue name since it can change
73     if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
74         return GetGDBProcess().GetDispatchQueueNameForThread (m_thread_dispatch_qaddr, m_dispatch_queue_name);
75     return NULL;
76 }
77 
78 bool
79 ThreadGDBRemote::WillResume (StateType resume_state)
80 {
81     ClearStackFrames();
82     // Call the Thread::WillResume first. If we stop at a signal, the stop info
83     // class for signal will set the resume signal that we need below. The signal
84     // stuff obeys the Process::UnixSignal defaults.
85     Thread::WillResume(resume_state);
86 
87     int signo = GetResumeSignal();
88 
89     switch (resume_state)
90     {
91     case eStateSuspended:
92     case eStateStopped:
93         // Don't append anything for threads that should stay stopped.
94         break;
95 
96     case eStateRunning:
97         if (m_process.GetUnixSignals().SignalIsValid (signo))
98             GetGDBProcess().m_continue_packet.Printf(";C%2.2x:%4.4x", signo, GetID());
99         else
100             GetGDBProcess().m_continue_packet.Printf(";c:%4.4x", GetID());
101         break;
102 
103     case eStateStepping:
104         if (m_process.GetUnixSignals().SignalIsValid (signo))
105             GetGDBProcess().m_continue_packet.Printf(";S%2.2x:%4.4x", signo, GetID());
106         else
107             GetGDBProcess().m_continue_packet.Printf(";s:%4.4x", GetID());
108         break;
109 
110     default:
111         break;
112     }
113     return true;
114 }
115 
116 void
117 ThreadGDBRemote::RefreshStateAfterStop()
118 {
119     // Invalidate all registers in our register context. We don't set "force" to
120     // true because the stop reply packet might have had some register values
121     // that were expedited and these will already be copied into the register
122     // context by the time this function gets called. The GDBRemoteRegisterContext
123     // class has been made smart enough to detect when it needs to invalidate
124     // which registers are valid by putting hooks in the register read and
125     // register supply functions where they check the process stop ID and do
126     // the right thing.
127     const bool force = false;
128     GetRegisterContext()->InvalidateIfNeeded (force);
129 }
130 
131 Unwind *
132 ThreadGDBRemote::GetUnwinder ()
133 {
134     if (m_unwinder_ap.get() == NULL)
135     {
136         const ArchSpec target_arch (GetProcess().GetTarget().GetArchitecture ());
137         if (target_arch == ArchSpec("x86_64") ||  target_arch == ArchSpec("i386"))
138         {
139             m_unwinder_ap.reset (new UnwindLLDB (*this));
140         }
141         else
142         {
143             m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
144         }
145     }
146     return m_unwinder_ap.get();
147 }
148 
149 void
150 ThreadGDBRemote::ClearStackFrames ()
151 {
152     Unwind *unwinder = GetUnwinder ();
153     if (unwinder)
154         unwinder->Clear();
155     Thread::ClearStackFrames();
156 }
157 
158 
159 bool
160 ThreadGDBRemote::ThreadIDIsValid (lldb::tid_t thread)
161 {
162     return thread != 0;
163 }
164 
165 void
166 ThreadGDBRemote::Dump(Log *log, uint32_t index)
167 {
168 }
169 
170 
171 bool
172 ThreadGDBRemote::ShouldStop (bool &step_more)
173 {
174     return true;
175 }
176 lldb::RegisterContextSP
177 ThreadGDBRemote::GetRegisterContext ()
178 {
179     if (m_reg_context_sp.get() == NULL)
180         m_reg_context_sp = CreateRegisterContextForFrame (NULL);
181     return m_reg_context_sp;
182 }
183 
184 lldb::RegisterContextSP
185 ThreadGDBRemote::CreateRegisterContextForFrame (StackFrame *frame)
186 {
187     lldb::RegisterContextSP reg_ctx_sp;
188     const bool read_all_registers_at_once = false;
189     uint32_t concrete_frame_idx = 0;
190 
191     if (frame)
192         concrete_frame_idx = frame->GetConcreteFrameIndex ();
193 
194     if (concrete_frame_idx == 0)
195         reg_ctx_sp.reset (new GDBRemoteRegisterContext (*this, concrete_frame_idx, GetGDBProcess().m_register_info, read_all_registers_at_once));
196     else if (m_unwinder_ap.get())
197         reg_ctx_sp = m_unwinder_ap->CreateRegisterContextForFrame (frame);
198     return reg_ctx_sp;
199 }
200 
201 void
202 ThreadGDBRemote::PrivateSetRegisterValue (uint32_t reg, StringExtractor &response)
203 {
204     GDBRemoteRegisterContext *gdb_reg_ctx = static_cast<GDBRemoteRegisterContext *>(GetRegisterContext ().get());
205     assert (gdb_reg_ctx);
206     gdb_reg_ctx->PrivateSetRegisterValue (reg, response);
207 }
208 
209 bool
210 ThreadGDBRemote::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
211 {
212     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
213     if (frame_sp)
214     {
215         checkpoint.SetStackID(frame_sp->GetStackID());
216         return frame_sp->GetRegisterContext()->ReadAllRegisterValues (checkpoint.GetData());
217     }
218     return false;
219 }
220 
221 bool
222 ThreadGDBRemote::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
223 {
224     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
225     if (frame_sp)
226     {
227         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (checkpoint.GetData());
228         frame_sp->GetRegisterContext()->InvalidateIfNeeded(true);
229         ClearStackFrames();
230         return ret;
231     }
232     return false;
233 }
234 
235 lldb::StopInfoSP
236 ThreadGDBRemote::GetPrivateStopReason ()
237 {
238     const uint32_t process_stop_id = GetProcess().GetStopID();
239     if (m_thread_stop_reason_stop_id != process_stop_id ||
240         (m_actual_stop_info_sp && !m_actual_stop_info_sp->IsValid()))
241     {
242         // If GetGDBProcess().SetThreadStopInfo() doesn't find a stop reason
243         // for this thread, then m_actual_stop_info_sp will not ever contain
244         // a valid stop reason and the "m_actual_stop_info_sp->IsValid() == false"
245         // check will never be able to tell us if we have the correct stop info
246         // for this thread and we will continually send qThreadStopInfo packets
247         // down to the remote GDB server, so we need to keep our own notion
248         // of the stop ID that m_actual_stop_info_sp is valid for (even if it
249         // contains nothing). We use m_thread_stop_reason_stop_id for this below.
250         m_thread_stop_reason_stop_id = process_stop_id;
251         m_actual_stop_info_sp.reset();
252 
253         char packet[256];
254         ::snprintf(packet, sizeof(packet), "qThreadStopInfo%x", GetID());
255         StringExtractorGDBRemote stop_packet;
256         if (GetGDBProcess().GetGDBRemote().SendPacketAndWaitForResponse(packet, stop_packet, 1, false))
257         {
258             GetGDBProcess().SetThreadStopInfo (stop_packet);
259         }
260     }
261     return m_actual_stop_info_sp;
262 }
263 
264 
265