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