1 //===-- ThreadPlan.cpp ----------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Target/ThreadPlan.h"
10 #include "lldb/Core/Debugger.h"
11 #include "lldb/Target/Process.h"
12 #include "lldb/Target/RegisterContext.h"
13 #include "lldb/Target/Target.h"
14 #include "lldb/Target/Thread.h"
15 #include "lldb/Utility/Log.h"
16 #include "lldb/Utility/State.h"
17 
18 using namespace lldb;
19 using namespace lldb_private;
20 
21 // ThreadPlan constructor
22 ThreadPlan::ThreadPlan(ThreadPlanKind kind, const char *name, Thread &thread,
23                        Vote stop_vote, Vote run_vote)
24     : m_process(*thread.GetProcess().get()), m_tid(thread.GetID()),
25       m_stop_vote(stop_vote), m_run_vote(run_vote),
26       m_takes_iteration_count(false), m_could_not_resolve_hw_bp(false),
27       m_kind(kind), m_thread(&thread), m_name(name), m_plan_complete_mutex(),
28       m_cached_plan_explains_stop(eLazyBoolCalculate), m_plan_complete(false),
29       m_plan_private(false), m_okay_to_discard(true), m_is_master_plan(false),
30       m_plan_succeeded(true) {
31   SetID(GetNextID());
32 }
33 
34 // Destructor
35 ThreadPlan::~ThreadPlan() = default;
36 
37 Target &ThreadPlan::GetTarget() { return m_process.GetTarget(); }
38 
39 const Target &ThreadPlan::GetTarget() const { return m_process.GetTarget(); }
40 
41 Thread &ThreadPlan::GetThread() {
42   if (m_thread)
43     return *m_thread;
44 
45   ThreadSP thread_sp = m_process.GetThreadList().FindThreadByID(m_tid);
46   m_thread = thread_sp.get();
47   return *m_thread;
48 }
49 
50 bool ThreadPlan::PlanExplainsStop(Event *event_ptr) {
51   if (m_cached_plan_explains_stop == eLazyBoolCalculate) {
52     bool actual_value = DoPlanExplainsStop(event_ptr);
53     m_cached_plan_explains_stop = actual_value ? eLazyBoolYes : eLazyBoolNo;
54     return actual_value;
55   } else {
56     return m_cached_plan_explains_stop == eLazyBoolYes;
57   }
58 }
59 
60 bool ThreadPlan::IsPlanComplete() {
61   std::lock_guard<std::recursive_mutex> guard(m_plan_complete_mutex);
62   return m_plan_complete;
63 }
64 
65 void ThreadPlan::SetPlanComplete(bool success) {
66   std::lock_guard<std::recursive_mutex> guard(m_plan_complete_mutex);
67   m_plan_complete = true;
68   m_plan_succeeded = success;
69 }
70 
71 bool ThreadPlan::MischiefManaged() {
72   std::lock_guard<std::recursive_mutex> guard(m_plan_complete_mutex);
73   // Mark the plan is complete, but don't override the success flag.
74   m_plan_complete = true;
75   return true;
76 }
77 
78 Vote ThreadPlan::ShouldReportStop(Event *event_ptr) {
79   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
80 
81   if (m_stop_vote == eVoteNoOpinion) {
82     ThreadPlan *prev_plan = GetPreviousPlan();
83     if (prev_plan) {
84       Vote prev_vote = prev_plan->ShouldReportStop(event_ptr);
85       LLDB_LOG(log, "returning previous thread plan vote: {0}", prev_vote);
86       return prev_vote;
87     }
88   }
89   LLDB_LOG(log, "Returning vote: {0}", m_stop_vote);
90   return m_stop_vote;
91 }
92 
93 Vote ThreadPlan::ShouldReportRun(Event *event_ptr) {
94   if (m_run_vote == eVoteNoOpinion) {
95     ThreadPlan *prev_plan = GetPreviousPlan();
96     if (prev_plan)
97       return prev_plan->ShouldReportRun(event_ptr);
98   }
99   return m_run_vote;
100 }
101 
102 bool ThreadPlan::StopOthers() {
103   ThreadPlan *prev_plan;
104   prev_plan = GetPreviousPlan();
105   return (prev_plan == nullptr) ? false : prev_plan->StopOthers();
106 }
107 
108 void ThreadPlan::SetStopOthers(bool new_value) {
109   // SetStopOthers doesn't work up the hierarchy.  You have to set the explicit
110   // ThreadPlan you want to affect.
111 }
112 
113 bool ThreadPlan::WillResume(StateType resume_state, bool current_plan) {
114   m_cached_plan_explains_stop = eLazyBoolCalculate;
115 
116   if (current_plan) {
117     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
118 
119     if (log) {
120       RegisterContext *reg_ctx = GetThread().GetRegisterContext().get();
121       assert(reg_ctx);
122       addr_t pc = reg_ctx->GetPC();
123       addr_t sp = reg_ctx->GetSP();
124       addr_t fp = reg_ctx->GetFP();
125       LLDB_LOGF(
126           log,
127           "%s Thread #%u (0x%p): tid = 0x%4.4" PRIx64 ", pc = 0x%8.8" PRIx64
128           ", sp = 0x%8.8" PRIx64 ", fp = 0x%8.8" PRIx64 ", "
129           "plan = '%s', state = %s, stop others = %d",
130           __FUNCTION__, GetThread().GetIndexID(),
131           static_cast<void *>(&GetThread()), m_tid, static_cast<uint64_t>(pc),
132           static_cast<uint64_t>(sp), static_cast<uint64_t>(fp), m_name.c_str(),
133           StateAsCString(resume_state), StopOthers());
134     }
135   }
136   return DoWillResume(resume_state, current_plan);
137 }
138 
139 lldb::user_id_t ThreadPlan::GetNextID() {
140   static uint32_t g_nextPlanID = 0;
141   return ++g_nextPlanID;
142 }
143 
144 void ThreadPlan::DidPush() {}
145 
146 void ThreadPlan::WillPop() {}
147 
148 bool ThreadPlan::OkayToDiscard() {
149   return IsMasterPlan() ? m_okay_to_discard : true;
150 }
151 
152 lldb::StateType ThreadPlan::RunState() {
153   if (m_tracer_sp && m_tracer_sp->TracingEnabled() &&
154       m_tracer_sp->SingleStepEnabled())
155     return eStateStepping;
156   else
157     return GetPlanRunState();
158 }
159 
160 bool ThreadPlan::IsUsuallyUnexplainedStopReason(lldb::StopReason reason) {
161   switch (reason) {
162   case eStopReasonWatchpoint:
163   case eStopReasonSignal:
164   case eStopReasonException:
165   case eStopReasonExec:
166   case eStopReasonThreadExiting:
167   case eStopReasonInstrumentation:
168     return true;
169   default:
170     return false;
171   }
172 }
173 
174 // ThreadPlanNull
175 
176 ThreadPlanNull::ThreadPlanNull(Thread &thread)
177     : ThreadPlan(ThreadPlan::eKindNull, "Null Thread Plan", thread,
178                  eVoteNoOpinion, eVoteNoOpinion) {}
179 
180 ThreadPlanNull::~ThreadPlanNull() = default;
181 
182 void ThreadPlanNull::GetDescription(Stream *s, lldb::DescriptionLevel level) {
183   s->PutCString("Null thread plan - thread has been destroyed.");
184 }
185 
186 bool ThreadPlanNull::ValidatePlan(Stream *error) {
187 #ifdef LLDB_CONFIGURATION_DEBUG
188   fprintf(stderr,
189           "error: %s called on thread that has been destroyed (tid = 0x%" PRIx64
190           ", ptid = 0x%" PRIx64 ")",
191           LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
192 #else
193   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
194   if (log)
195     log->Error("%s called on thread that has been destroyed (tid = 0x%" PRIx64
196                ", ptid = 0x%" PRIx64 ")",
197                LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
198 #endif
199   return true;
200 }
201 
202 bool ThreadPlanNull::ShouldStop(Event *event_ptr) {
203 #ifdef LLDB_CONFIGURATION_DEBUG
204   fprintf(stderr,
205           "error: %s called on thread that has been destroyed (tid = 0x%" PRIx64
206           ", ptid = 0x%" PRIx64 ")",
207           LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
208 #else
209   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
210   if (log)
211     log->Error("%s called on thread that has been destroyed (tid = 0x%" PRIx64
212                ", ptid = 0x%" PRIx64 ")",
213                LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
214 #endif
215   return true;
216 }
217 
218 bool ThreadPlanNull::WillStop() {
219 #ifdef LLDB_CONFIGURATION_DEBUG
220   fprintf(stderr,
221           "error: %s called on thread that has been destroyed (tid = 0x%" PRIx64
222           ", ptid = 0x%" PRIx64 ")",
223           LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
224 #else
225   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
226   if (log)
227     log->Error("%s called on thread that has been destroyed (tid = 0x%" PRIx64
228                ", ptid = 0x%" PRIx64 ")",
229                LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
230 #endif
231   return true;
232 }
233 
234 bool ThreadPlanNull::DoPlanExplainsStop(Event *event_ptr) {
235 #ifdef LLDB_CONFIGURATION_DEBUG
236   fprintf(stderr,
237           "error: %s called on thread that has been destroyed (tid = 0x%" PRIx64
238           ", ptid = 0x%" PRIx64 ")",
239           LLVM_PRETTY_FUNCTION, m_thread.GetID(), m_thread.GetProtocolID());
240 #else
241   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
242   if (log)
243     log->Error("%s called on thread that has been destroyed (tid = 0x%" PRIx64
244                ", ptid = 0x%" PRIx64 ")",
245                LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
246 #endif
247   return true;
248 }
249 
250 // The null plan is never done.
251 bool ThreadPlanNull::MischiefManaged() {
252 // The null plan is never done.
253 #ifdef LLDB_CONFIGURATION_DEBUG
254   fprintf(stderr,
255           "error: %s called on thread that has been destroyed (tid = 0x%" PRIx64
256           ", ptid = 0x%" PRIx64 ")",
257           LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
258 #else
259   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
260   if (log)
261     log->Error("%s called on thread that has been destroyed (tid = 0x%" PRIx64
262                ", ptid = 0x%" PRIx64 ")",
263                LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
264 #endif
265   return false;
266 }
267 
268 lldb::StateType ThreadPlanNull::GetPlanRunState() {
269 // Not sure what to return here.  This is a dead thread.
270 #ifdef LLDB_CONFIGURATION_DEBUG
271   fprintf(stderr,
272           "error: %s called on thread that has been destroyed (tid = 0x%" PRIx64
273           ", ptid = 0x%" PRIx64 ")",
274           LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
275 #else
276   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
277   if (log)
278     log->Error("%s called on thread that has been destroyed (tid = 0x%" PRIx64
279                ", ptid = 0x%" PRIx64 ")",
280                LLVM_PRETTY_FUNCTION, m_tid, GetThread().GetProtocolID());
281 #endif
282   return eStateRunning;
283 }
284