xref: /llvm-project/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp (revision b3ae87617437c5850003cd7ab35e0b3581d2b7da)
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/Watchpoint.h"
23 
24 #include "ProcessGDBRemote.h"
25 #include "ProcessGDBRemoteLog.h"
26 #include "Utility/StringExtractorGDBRemote.h"
27 
28 using namespace lldb;
29 using namespace lldb_private;
30 
31 //----------------------------------------------------------------------
32 // Thread Registers
33 //----------------------------------------------------------------------
34 
35 ThreadGDBRemote::ThreadGDBRemote (Process &process, lldb::tid_t tid) :
36     Thread(process, tid),
37     m_thread_name (),
38     m_dispatch_queue_name (),
39     m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS)
40 {
41     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::ThreadGDBRemote (pid = %i, tid = 0x%4.4x)",
42                                this,
43                                process.GetID(),
44                                GetID());
45 }
46 
47 ThreadGDBRemote::~ThreadGDBRemote ()
48 {
49     ProcessSP process_sp(GetProcess());
50     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::~ThreadGDBRemote (pid = %i, tid = 0x%4.4x)",
51                                this,
52                                process_sp ? process_sp->GetID() : LLDB_INVALID_PROCESS_ID,
53                                GetID());
54     DestroyThread();
55 }
56 
57 const char *
58 ThreadGDBRemote::GetName ()
59 {
60     if (m_thread_name.empty())
61         return NULL;
62     return m_thread_name.c_str();
63 }
64 
65 
66 const char *
67 ThreadGDBRemote::GetQueueName ()
68 {
69     // Always re-fetch the dispatch queue name since it can change
70 
71     if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
72     {
73         ProcessSP process_sp (GetProcess());
74         if (process_sp)
75         {
76             ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
77             return gdb_process->GetDispatchQueueNameForThread (m_thread_dispatch_qaddr, m_dispatch_queue_name);
78         }
79     }
80     return NULL;
81 }
82 
83 bool
84 ThreadGDBRemote::WillResume (StateType resume_state)
85 {
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     // If the thread's WillResume returns false, that means that we aren't going to actually resume,
90     // in which case we should not do the rest of our "resume" work.
91 
92     if (!Thread::WillResume(resume_state))
93         return false;
94 
95     ClearStackFrames();
96 
97     int signo = GetResumeSignal();
98     Log *log(lldb_private::GetLogIfAnyCategoriesSet (GDBR_LOG_THREAD));
99     if (log)
100         log->Printf ("Resuming thread: %4.4" PRIx64 " with state: %s.", GetID(), StateAsCString(resume_state));
101 
102     ProcessSP process_sp (GetProcess());
103     if (process_sp)
104     {
105         ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
106         switch (resume_state)
107         {
108         case eStateSuspended:
109         case eStateStopped:
110             // Don't append anything for threads that should stay stopped.
111             break;
112 
113         case eStateRunning:
114             if (gdb_process->GetUnixSignals().SignalIsValid (signo))
115                 gdb_process->m_continue_C_tids.push_back(std::make_pair(GetID(), signo));
116             else
117                 gdb_process->m_continue_c_tids.push_back(GetID());
118             break;
119 
120         case eStateStepping:
121             if (gdb_process->GetUnixSignals().SignalIsValid (signo))
122                 gdb_process->m_continue_S_tids.push_back(std::make_pair(GetID(), signo));
123             else
124                 gdb_process->m_continue_s_tids.push_back(GetID());
125             break;
126 
127         default:
128             break;
129         }
130         return true;
131     }
132     return false;
133 }
134 
135 void
136 ThreadGDBRemote::RefreshStateAfterStop()
137 {
138     // Invalidate all registers in our register context. We don't set "force" to
139     // true because the stop reply packet might have had some register values
140     // that were expedited and these will already be copied into the register
141     // context by the time this function gets called. The GDBRemoteRegisterContext
142     // class has been made smart enough to detect when it needs to invalidate
143     // which registers are valid by putting hooks in the register read and
144     // register supply functions where they check the process stop ID and do
145     // the right thing.
146     const bool force = false;
147     GetRegisterContext()->InvalidateIfNeeded (force);
148 }
149 
150 void
151 ThreadGDBRemote::ClearStackFrames ()
152 {
153     Unwind *unwinder = GetUnwinder ();
154     if (unwinder)
155         unwinder->Clear();
156     Thread::ClearStackFrames();
157 }
158 
159 
160 bool
161 ThreadGDBRemote::ThreadIDIsValid (lldb::tid_t thread)
162 {
163     return thread != 0;
164 }
165 
166 void
167 ThreadGDBRemote::Dump(Log *log, uint32_t index)
168 {
169 }
170 
171 
172 bool
173 ThreadGDBRemote::ShouldStop (bool &step_more)
174 {
175     return true;
176 }
177 lldb::RegisterContextSP
178 ThreadGDBRemote::GetRegisterContext ()
179 {
180     if (m_reg_context_sp.get() == NULL)
181         m_reg_context_sp = CreateRegisterContextForFrame (NULL);
182     return m_reg_context_sp;
183 }
184 
185 lldb::RegisterContextSP
186 ThreadGDBRemote::CreateRegisterContextForFrame (StackFrame *frame)
187 {
188     lldb::RegisterContextSP reg_ctx_sp;
189     const bool read_all_registers_at_once = false;
190     uint32_t concrete_frame_idx = 0;
191 
192     if (frame)
193         concrete_frame_idx = frame->GetConcreteFrameIndex ();
194 
195 
196     if (concrete_frame_idx == 0)
197     {
198         ProcessSP process_sp (GetProcess());
199         if (process_sp)
200         {
201             ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
202             reg_ctx_sp.reset (new GDBRemoteRegisterContext (*this, concrete_frame_idx, gdb_process->m_register_info, read_all_registers_at_once));
203         }
204     }
205     else
206     {
207         Unwind *unwinder = GetUnwinder ();
208         if (unwinder)
209             reg_ctx_sp = unwinder->CreateRegisterContextForFrame (frame);
210     }
211     return reg_ctx_sp;
212 }
213 
214 bool
215 ThreadGDBRemote::PrivateSetRegisterValue (uint32_t reg, StringExtractor &response)
216 {
217     GDBRemoteRegisterContext *gdb_reg_ctx = static_cast<GDBRemoteRegisterContext *>(GetRegisterContext ().get());
218     assert (gdb_reg_ctx);
219     return gdb_reg_ctx->PrivateSetRegisterValue (reg, response);
220 }
221 
222 lldb::StopInfoSP
223 ThreadGDBRemote::GetPrivateStopReason ()
224 {
225     ProcessSP process_sp (GetProcess());
226     if (process_sp)
227     {
228         const uint32_t process_stop_id = process_sp->GetStopID();
229         if (m_thread_stop_reason_stop_id != process_stop_id ||
230             (m_actual_stop_info_sp && !m_actual_stop_info_sp->IsValid()))
231         {
232             if (IsStillAtLastBreakpointHit())
233                 return m_actual_stop_info_sp;
234 
235             // If GetGDBProcess().SetThreadStopInfo() doesn't find a stop reason
236             // for this thread, then m_actual_stop_info_sp will not ever contain
237             // a valid stop reason and the "m_actual_stop_info_sp->IsValid() == false"
238             // check will never be able to tell us if we have the correct stop info
239             // for this thread and we will continually send qThreadStopInfo packets
240             // down to the remote GDB server, so we need to keep our own notion
241             // of the stop ID that m_actual_stop_info_sp is valid for (even if it
242             // contains nothing). We use m_thread_stop_reason_stop_id for this below.
243             m_thread_stop_reason_stop_id = process_stop_id;
244             m_actual_stop_info_sp.reset();
245 
246             StringExtractorGDBRemote stop_packet;
247             ProcessGDBRemote *gdb_process = static_cast<ProcessGDBRemote *>(process_sp.get());
248             if (gdb_process->GetGDBRemote().GetThreadStopInfo(GetID(), stop_packet))
249                 gdb_process->SetThreadStopInfo (stop_packet);
250         }
251     }
252     return m_actual_stop_info_sp;
253 }
254 
255 
256