1 //===-- StopInfo.h ----------------------------------------------*- 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 #ifndef LLDB_TARGET_STOPINFO_H 10 #define LLDB_TARGET_STOPINFO_H 11 12 #include <string> 13 14 #include "lldb/Target/Process.h" 15 #include "lldb/Utility/StructuredData.h" 16 #include "lldb/lldb-public.h" 17 18 namespace lldb_private { 19 20 class StopInfo : public std::enable_shared_from_this<StopInfo> { 21 friend class Process::ProcessEventData; 22 friend class ThreadPlanBase; 23 24 public: 25 // Constructors and Destructors 26 StopInfo(Thread &thread, uint64_t value); 27 28 virtual ~StopInfo() = default; 29 30 bool IsValid() const; 31 32 void SetThread(const lldb::ThreadSP &thread_sp) { m_thread_wp = thread_sp; } 33 34 lldb::ThreadSP GetThread() const { return m_thread_wp.lock(); } 35 36 // The value of the StopInfo depends on the StopReason. 37 // 38 // StopReason Meaning 39 // ------------------------------------------------ 40 // eStopReasonBreakpoint BreakpointSiteID 41 // eStopReasonSignal Signal number 42 // eStopReasonWatchpoint WatchpointLocationID 43 // eStopReasonPlanComplete No significance 44 45 uint64_t GetValue() const { return m_value; } 46 47 virtual lldb::StopReason GetStopReason() const = 0; 48 49 // ShouldStopSynchronous will get called before any thread plans are 50 // consulted, and if it says we should resume the target, then we will just 51 // immediately resume. This should not run any code in or resume the target. 52 53 virtual bool ShouldStopSynchronous(Event *event_ptr) { return true; } 54 55 void OverrideShouldNotify(bool override_value) { 56 m_override_should_notify = override_value ? eLazyBoolYes : eLazyBoolNo; 57 } 58 59 // If should stop returns false, check if we should notify of this event 60 virtual bool ShouldNotify(Event *event_ptr) { 61 if (m_override_should_notify == eLazyBoolCalculate) 62 return DoShouldNotify(event_ptr); 63 else 64 return m_override_should_notify == eLazyBoolYes; 65 } 66 67 virtual void WillResume(lldb::StateType resume_state) { 68 // By default, don't do anything 69 } 70 71 virtual const char *GetDescription() { return m_description.c_str(); } 72 73 virtual void SetDescription(const char *desc_cstr) { 74 if (desc_cstr && desc_cstr[0]) 75 m_description.assign(desc_cstr); 76 else 77 m_description.clear(); 78 } 79 80 /// This gives the StopInfo a chance to suggest a stack frame to select. 81 /// Passing true for inlined_stack will request changes to the inlined 82 /// call stack. Passing false will request changes to the real stack 83 /// frame. The inlined stack gets adjusted before we call into the thread 84 /// plans so they can reason based on the correct values. The real stack 85 /// adjustment is handled after the frame recognizers get a chance to adjust 86 /// the frame. 87 virtual std::optional<uint32_t> 88 GetSuggestedStackFrameIndex(bool inlined_stack) { 89 return {}; 90 } 91 92 virtual bool IsValidForOperatingSystemThread(Thread &thread) { return true; } 93 94 /// A Continue operation can result in a false stop event 95 /// before any execution has happened. We need to detect this 96 /// and silently continue again one more time. 97 virtual bool WasContinueInterrupted(Thread &thread) { return false; } 98 99 // Sometimes the thread plan logic will know that it wants a given stop to 100 // stop or not, regardless of what the ordinary logic for that StopInfo would 101 // dictate. The main example of this is the ThreadPlanCallFunction, which 102 // for instance knows - based on how that particular expression was executed 103 // - whether it wants all breakpoints to auto-continue or not. Use 104 // OverrideShouldStop on the StopInfo to implement this. 105 106 void OverrideShouldStop(bool override_value) { 107 m_override_should_stop = override_value ? eLazyBoolYes : eLazyBoolNo; 108 } 109 110 bool GetOverrideShouldStop() { 111 return m_override_should_stop != eLazyBoolCalculate; 112 } 113 114 bool GetOverriddenShouldStopValue() { 115 return m_override_should_stop == eLazyBoolYes; 116 } 117 118 StructuredData::ObjectSP GetExtendedInfo() { return m_extended_info; } 119 120 static lldb::StopInfoSP 121 CreateStopReasonWithBreakpointSiteID(Thread &thread, 122 lldb::break_id_t break_id); 123 124 // This creates a StopInfo for the thread where the should_stop is already 125 // set, and won't be recalculated. 126 static lldb::StopInfoSP CreateStopReasonWithBreakpointSiteID( 127 Thread &thread, lldb::break_id_t break_id, bool should_stop); 128 129 static lldb::StopInfoSP 130 CreateStopReasonWithWatchpointID(Thread &thread, lldb::break_id_t watch_id, 131 bool silently_continue = false); 132 133 static lldb::StopInfoSP 134 CreateStopReasonWithSignal(Thread &thread, int signo, 135 const char *description = nullptr, 136 std::optional<int> code = std::nullopt); 137 138 static lldb::StopInfoSP 139 CreateStopReasonWithInterrupt(Thread &thread, int signo, 140 const char *description); 141 142 static lldb::StopInfoSP CreateStopReasonToTrace(Thread &thread); 143 144 static lldb::StopInfoSP 145 CreateStopReasonWithPlan(lldb::ThreadPlanSP &plan, 146 lldb::ValueObjectSP return_valobj_sp, 147 lldb::ExpressionVariableSP expression_variable_sp); 148 149 static lldb::StopInfoSP 150 CreateStopReasonWithException(Thread &thread, const char *description); 151 152 static lldb::StopInfoSP CreateStopReasonWithExec(Thread &thread); 153 154 static lldb::StopInfoSP 155 CreateStopReasonProcessorTrace(Thread &thread, const char *description); 156 157 static lldb::StopInfoSP CreateStopReasonFork(Thread &thread, 158 lldb::pid_t child_pid, 159 lldb::tid_t child_tid); 160 161 static lldb::StopInfoSP CreateStopReasonVFork(Thread &thread, 162 lldb::pid_t child_pid, 163 lldb::tid_t child_tid); 164 165 static lldb::StopInfoSP CreateStopReasonVForkDone(Thread &thread); 166 167 static lldb::ValueObjectSP 168 GetReturnValueObject(lldb::StopInfoSP &stop_info_sp); 169 170 static lldb::ExpressionVariableSP 171 GetExpressionVariable(lldb::StopInfoSP &stop_info_sp); 172 173 static lldb::ValueObjectSP 174 GetCrashingDereference(lldb::StopInfoSP &stop_info_sp, 175 lldb::addr_t *crashing_address = nullptr); 176 177 protected: 178 // Perform any action that is associated with this stop. This is done as the 179 // Event is removed from the event queue. ProcessEventData::DoOnRemoval does 180 // the job. 181 182 virtual void PerformAction(Event *event_ptr) {} 183 184 virtual bool DoShouldNotify(Event *event_ptr) { return false; } 185 186 // Stop the thread by default. Subclasses can override this to allow the 187 // thread to continue if desired. The ShouldStop method should not do 188 // anything that might run code. If you need to run code when deciding 189 // whether to stop at this StopInfo, that must be done in the PerformAction. 190 // The PerformAction will always get called before the ShouldStop. This is 191 // done by the ProcessEventData::DoOnRemoval, though the ThreadPlanBase needs 192 // to consult this later on. 193 virtual bool ShouldStop(Event *event_ptr) { return true; } 194 195 // Classes that inherit from StackID can see and modify these 196 lldb::ThreadWP m_thread_wp; // The thread corresponding to the stop reason. 197 uint32_t m_stop_id; // The process stop ID for which this stop info is valid 198 uint32_t m_resume_id; // This is the resume ID when we made this stop ID. 199 uint64_t m_value; // A generic value that can be used for things pertaining to 200 // this stop info 201 std::string m_description; // A textual description describing this stop. 202 LazyBool m_override_should_notify; 203 LazyBool m_override_should_stop; 204 205 StructuredData::ObjectSP 206 m_extended_info; // The extended info for this stop info 207 208 // This determines whether the target has run since this stop info. N.B. 209 // running to evaluate a user expression does not count. 210 bool HasTargetRunSinceMe(); 211 212 // MakeStopInfoValid is necessary to allow saved stop infos to resurrect 213 // themselves as valid. It should only be used by 214 // Thread::RestoreThreadStateFromCheckpoint and to make sure the one-step 215 // needed for before-the-fact watchpoints does not prevent us from stopping 216 void MakeStopInfoValid(); 217 218 private: 219 friend class Thread; 220 221 StopInfo(const StopInfo &) = delete; 222 const StopInfo &operator=(const StopInfo &) = delete; 223 }; 224 225 } // namespace lldb_private 226 227 #endif // LLDB_TARGET_STOPINFO_H 228