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/Target.h"
19 #include "lldb/Target/Unwind.h"
20 #include "lldb/Breakpoint/WatchpointLocation.h"
21 
22 #include "LibUnwindRegisterContext.h"
23 #include "ProcessGDBRemote.h"
24 #include "ProcessGDBRemoteLog.h"
25 #include "StringExtractorGDBRemote.h"
26 #include "UnwindLibUnwind.h"
27 #include "UnwindMacOSXFrameBackchain.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_stop_info_stop_id (0),
39     m_stop_info (this),
40     m_thread_name (),
41     m_dispatch_queue_name (),
42     m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS),
43     m_unwinder_ap ()
44 {
45 //    ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD | GDBR_LOG_VERBOSE, "ThreadGDBRemote::ThreadGDBRemote ( pid = %i, tid = 0x%4.4x, )", m_process.GetID(), GetID());
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 }
53 
54 
55 const char *
56 ThreadGDBRemote::GetInfo ()
57 {
58     return NULL;
59 }
60 
61 
62 const char *
63 ThreadGDBRemote::GetName ()
64 {
65     if (m_thread_name.empty())
66         return NULL;
67     return m_thread_name.c_str();
68 }
69 
70 
71 const char *
72 ThreadGDBRemote::GetQueueName ()
73 {
74     // Always re-fetch the dispatch queue name since it can change
75     if (m_thread_dispatch_qaddr != 0 || m_thread_dispatch_qaddr != LLDB_INVALID_ADDRESS)
76         return GetGDBProcess().GetDispatchQueueNameForThread (m_thread_dispatch_qaddr, m_dispatch_queue_name);
77     return NULL;
78 }
79 
80 bool
81 ThreadGDBRemote::WillResume (StateType resume_state)
82 {
83     // TODO: cache for next time in case we can match things up??
84     ClearStackFrames();
85     int signo = GetResumeSignal();
86     m_stop_info.Clear();
87     switch (resume_state)
88     {
89     case eStateSuspended:
90     case eStateStopped:
91         // Don't append anything for threads that should stay stopped.
92         break;
93 
94     case eStateRunning:
95         if (m_process.GetUnixSignals().SignalIsValid (signo))
96             GetGDBProcess().m_continue_packet.Printf(";C%2.2x:%4.4x", signo, GetID());
97         else
98             GetGDBProcess().m_continue_packet.Printf(";c:%4.4x", GetID());
99         break;
100 
101     case eStateStepping:
102         if (m_process.GetUnixSignals().SignalIsValid (signo))
103             GetGDBProcess().m_continue_packet.Printf(";S%2.2x:%4.4x", signo, GetID());
104         else
105             GetGDBProcess().m_continue_packet.Printf(";s:%4.4x", GetID());
106         break;
107     }
108     Thread::WillResume(resume_state);
109     return true;
110 }
111 
112 void
113 ThreadGDBRemote::RefreshStateAfterStop()
114 {
115     // Invalidate all registers in our register context
116     GetRegisterContext()->Invalidate();
117 }
118 
119 Unwind *
120 ThreadGDBRemote::GetUnwinder ()
121 {
122     if (m_unwinder_ap.get() == NULL)
123     {
124         const ArchSpec target_arch (GetProcess().GetTarget().GetArchitecture ());
125         if (target_arch == ArchSpec("x86_64") ||  target_arch == ArchSpec("i386"))
126         {
127             m_unwinder_ap.reset (new UnwindLibUnwind (*this, GetGDBProcess().GetLibUnwindAddressSpace()));
128         }
129         else
130         {
131             m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
132         }
133     }
134     return m_unwinder_ap.get();
135 }
136 
137 uint32_t
138 ThreadGDBRemote::GetStackFrameCount()
139 {
140     Unwind *unwinder = GetUnwinder ();
141     if (unwinder)
142         return unwinder->GetFrameCount();
143     return 0;
144 }
145 
146 // Make sure that GetStackFrameAtIndex() does NOT call GetStackFrameCount() when
147 // getting the stack frame at index zero! This way GetStackFrameCount() (via
148 // GetStackFRameData()) can call this function to get the first frame in order
149 // to provide the first frame to a lower call for efficiency sake (avoid
150 // redundant lookups in the frame symbol context).
151 lldb::StackFrameSP
152 ThreadGDBRemote::GetStackFrameAtIndex (uint32_t idx)
153 {
154 
155     StackFrameSP frame_sp (m_frames.GetFrameAtIndex(idx));
156 
157     if (frame_sp.get())
158         return frame_sp;
159 
160     // Don't try and fetch a frame while process is running
161 // FIXME: This check isn't right because IsRunning checks the Public state, but this
162 // is work you need to do - for instance in ShouldStop & friends - before the public
163 // state has been changed.
164 //    if (m_process.IsRunning())
165 //        return frame_sp;
166 
167     // Special case the first frame (idx == 0) so that we don't need to
168     // know how many stack frames there are to get it. If we need any other
169     // frames, then we do need to know if "idx" is a valid index.
170     if (idx == 0)
171     {
172         // If this is the first frame, we want to share the thread register
173         // context with the stack frame at index zero.
174         GetRegisterContext();
175         assert (m_reg_context_sp.get());
176         frame_sp.reset (new StackFrame (idx, *this, m_reg_context_sp, m_reg_context_sp->GetSP(), m_reg_context_sp->GetPC()));
177     }
178     else if (idx < GetStackFrameCount())
179     {
180         Unwind *unwinder = GetUnwinder ();
181         if (unwinder)
182         {
183             addr_t pc, cfa;
184             if (unwinder->GetFrameInfoAtIndex(idx, cfa, pc))
185                 frame_sp.reset (new StackFrame (idx, *this, cfa, pc));
186         }
187     }
188     m_frames.SetFrameAtIndex(idx, frame_sp);
189     return frame_sp;
190 }
191 
192 void
193 ThreadGDBRemote::ClearStackFrames ()
194 {
195     Unwind *unwinder = GetUnwinder ();
196     if (unwinder)
197         unwinder->Clear();
198     Thread::ClearStackFrames();
199 }
200 
201 
202 bool
203 ThreadGDBRemote::ThreadIDIsValid (lldb::tid_t thread)
204 {
205     return thread != 0;
206 }
207 
208 void
209 ThreadGDBRemote::Dump(Log *log, uint32_t index)
210 {
211 }
212 
213 
214 bool
215 ThreadGDBRemote::ShouldStop (bool &step_more)
216 {
217     return true;
218 }
219 RegisterContext *
220 ThreadGDBRemote::GetRegisterContext ()
221 {
222     if (m_reg_context_sp.get() == NULL)
223         m_reg_context_sp.reset (CreateRegisterContextForFrame (NULL));
224     return m_reg_context_sp.get();
225 }
226 
227 RegisterContext *
228 ThreadGDBRemote::CreateRegisterContextForFrame (StackFrame *frame)
229 {
230     const bool read_all_registers_at_once = false;
231     uint32_t frame_idx = 0;
232 
233     if (frame)
234         frame_idx = frame->GetID();
235 
236     if (frame_idx == 0)
237         return new GDBRemoteRegisterContext (*this, frame, GetGDBProcess().m_register_info, read_all_registers_at_once);
238     else if (m_unwinder_ap.get() && frame_idx < m_unwinder_ap->GetFrameCount())
239         return m_unwinder_ap->CreateRegisterContextForFrame (frame);
240     return NULL;
241 }
242 
243 bool
244 ThreadGDBRemote::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
245 {
246     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
247     if (frame_sp)
248     {
249         checkpoint.SetStackID(frame_sp->GetStackID());
250         return frame_sp->GetRegisterContext()->ReadAllRegisterValues (checkpoint.GetData());
251     }
252     return false;
253 }
254 
255 bool
256 ThreadGDBRemote::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
257 {
258     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
259     if (frame_sp)
260     {
261         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (checkpoint.GetData());
262         frame_sp->GetRegisterContext()->Invalidate();
263         ClearStackFrames();
264         return ret;
265     }
266     return false;
267 }
268 
269 bool
270 ThreadGDBRemote::GetRawStopReason (StopInfo *stop_info)
271 {
272     if (m_stop_info_stop_id != m_process.GetStopID())
273     {
274         char packet[256];
275         const int packet_len = snprintf(packet, sizeof(packet), "qThreadStopInfo%x", GetID());
276         assert (packet_len < (sizeof(packet) - 1));
277         StringExtractorGDBRemote stop_packet;
278         if (GetGDBProcess().GetGDBRemote().SendPacketAndWaitForResponse(packet, stop_packet, 1, false))
279         {
280             std::string copy(stop_packet.GetStringRef());
281             GetGDBProcess().SetThreadStopInfo (stop_packet);
282             // The process should have set the stop info stop ID and also
283             // filled this thread in with valid stop info
284             if (m_stop_info_stop_id != m_process.GetStopID())
285             {
286                 //ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "warning: qThreadStopInfo problem: '%s' => '%s'", packet, stop_packet.GetStringRef().c_str());
287                 printf("warning: qThreadStopInfo problem: '%s' => '%s'\n\torig '%s'\n", packet, stop_packet.GetStringRef().c_str(), copy.c_str()); /// REMOVE THIS
288                 return false;
289             }
290         }
291     }
292     *stop_info = m_stop_info;
293     return true;
294 }
295 
296 
297