330 lines · cpp
1//===-- ThreadPlanStepUntil.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "lldb/Target/ThreadPlanStepUntil.h"10 11#include "lldb/Breakpoint/Breakpoint.h"12#include "lldb/Symbol/SymbolContextScope.h"13#include "lldb/Target/Process.h"14#include "lldb/Target/RegisterContext.h"15#include "lldb/Target/StopInfo.h"16#include "lldb/Target/Target.h"17#include "lldb/Utility/LLDBLog.h"18#include "lldb/Utility/Log.h"19 20using namespace lldb;21using namespace lldb_private;22 23// ThreadPlanStepUntil: Run until we reach a given line number or step out of24// the current frame25 26ThreadPlanStepUntil::ThreadPlanStepUntil(Thread &thread,27 lldb::addr_t *address_list,28 size_t num_addresses, bool stop_others,29 uint32_t frame_idx)30 : ThreadPlan(ThreadPlan::eKindStepUntil, "Step until", thread,31 eVoteNoOpinion, eVoteNoOpinion),32 m_step_from_insn(LLDB_INVALID_ADDRESS),33 m_return_bp_id(LLDB_INVALID_BREAK_ID),34 m_return_addr(LLDB_INVALID_ADDRESS), m_stepped_out(false),35 m_should_stop(false), m_ran_analyze(false), m_explains_stop(false),36 m_until_points(), m_stop_others(stop_others) {37 // Stash away our "until" addresses:38 TargetSP target_sp(thread.CalculateTarget());39 40 StackFrameSP frame_sp(thread.GetStackFrameAtIndex(frame_idx));41 if (frame_sp) {42 m_step_from_insn = frame_sp->GetStackID().GetPC();43 44 // Find the return address and set a breakpoint there:45 // FIXME - can we do this more securely if we know first_insn?46 47 StackFrameSP return_frame_sp(thread.GetStackFrameAtIndex(frame_idx + 1));48 if (return_frame_sp) {49 // TODO: add inline functionality50 m_return_addr = return_frame_sp->GetStackID().GetPC();51 Breakpoint *return_bp =52 target_sp->CreateBreakpoint(m_return_addr, true, false).get();53 54 if (return_bp != nullptr) {55 if (return_bp->IsHardware() && !return_bp->HasResolvedLocations())56 m_could_not_resolve_hw_bp = true;57 return_bp->SetThreadID(m_tid);58 m_return_bp_id = return_bp->GetID();59 return_bp->SetBreakpointKind("until-return-backstop");60 }61 }62 63 m_stack_id = frame_sp->GetStackID();64 65 // Now set breakpoints on all our return addresses:66 for (size_t i = 0; i < num_addresses; i++) {67 Breakpoint *until_bp =68 target_sp->CreateBreakpoint(address_list[i], true, false).get();69 if (until_bp != nullptr) {70 until_bp->SetThreadID(m_tid);71 m_until_points[address_list[i]] = until_bp->GetID();72 until_bp->SetBreakpointKind("until-target");73 } else {74 m_until_points[address_list[i]] = LLDB_INVALID_BREAK_ID;75 }76 }77 }78}79 80ThreadPlanStepUntil::~ThreadPlanStepUntil() { Clear(); }81 82void ThreadPlanStepUntil::Clear() {83 Target &target = GetTarget();84 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) {85 target.RemoveBreakpointByID(m_return_bp_id);86 m_return_bp_id = LLDB_INVALID_BREAK_ID;87 }88 89 until_collection::iterator pos, end = m_until_points.end();90 for (pos = m_until_points.begin(); pos != end; pos++) {91 target.RemoveBreakpointByID((*pos).second);92 }93 m_until_points.clear();94 m_could_not_resolve_hw_bp = false;95}96 97void ThreadPlanStepUntil::GetDescription(Stream *s,98 lldb::DescriptionLevel level) {99 if (level == lldb::eDescriptionLevelBrief) {100 s->Printf("step until");101 if (m_stepped_out)102 s->Printf(" - stepped out");103 } else {104 if (m_until_points.size() == 1)105 s->Printf("Stepping from address 0x%" PRIx64 " until we reach 0x%" PRIx64106 " using breakpoint %d",107 (uint64_t)m_step_from_insn,108 (uint64_t)(*m_until_points.begin()).first,109 (*m_until_points.begin()).second);110 else {111 until_collection::iterator pos, end = m_until_points.end();112 s->Printf("Stepping from address 0x%" PRIx64 " until we reach one of:",113 (uint64_t)m_step_from_insn);114 for (pos = m_until_points.begin(); pos != end; pos++) {115 s->Printf("\n\t0x%" PRIx64 " (bp: %d)", (uint64_t)(*pos).first,116 (*pos).second);117 }118 }119 s->Printf(" stepped out address is 0x%" PRIx64 ".",120 (uint64_t)m_return_addr);121 }122}123 124bool ThreadPlanStepUntil::ValidatePlan(Stream *error) {125 if (m_could_not_resolve_hw_bp) {126 if (error)127 error->PutCString(128 "Could not create hardware breakpoint for thread plan.");129 return false;130 } else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) {131 if (error)132 error->PutCString("Could not create return breakpoint.");133 return false;134 } else {135 until_collection::iterator pos, end = m_until_points.end();136 for (pos = m_until_points.begin(); pos != end; pos++) {137 if (!LLDB_BREAK_ID_IS_VALID((*pos).second))138 return false;139 }140 return true;141 }142}143 144void ThreadPlanStepUntil::AnalyzeStop() {145 if (m_ran_analyze)146 return;147 148 StopInfoSP stop_info_sp = GetPrivateStopInfo();149 m_should_stop = true;150 m_explains_stop = false;151 152 if (stop_info_sp) {153 StopReason reason = stop_info_sp->GetStopReason();154 155 if (reason == eStopReasonBreakpoint) {156 // If this is OUR breakpoint, we're fine, otherwise we don't know why157 // this happened...158 BreakpointSiteSP this_site =159 m_process.GetBreakpointSiteList().FindByID(stop_info_sp->GetValue());160 if (!this_site) {161 m_explains_stop = false;162 return;163 }164 165 if (this_site->IsBreakpointAtThisSite(m_return_bp_id)) {166 // If we are at our "step out" breakpoint, and the stack depth has167 // shrunk, then this is indeed our stop. If the stack depth has grown,168 // then we've hit our step out breakpoint recursively. If we are the169 // only breakpoint at that location, then we do explain the stop, and170 // we'll just continue. If there was another breakpoint here, then we171 // don't explain the stop, but we won't mark ourselves Completed,172 // because maybe that breakpoint will continue, and then we'll finish173 // the "until".174 bool done;175 StackID cur_frame_zero_id;176 177 done = (m_stack_id < cur_frame_zero_id);178 179 if (done) {180 m_stepped_out = true;181 SetPlanComplete();182 } else183 m_should_stop = false;184 185 if (this_site->GetNumberOfConstituents() == 1)186 m_explains_stop = true;187 else188 m_explains_stop = false;189 return;190 } else {191 // Check if we've hit one of our "until" breakpoints.192 until_collection::iterator pos, end = m_until_points.end();193 for (pos = m_until_points.begin(); pos != end; pos++) {194 if (this_site->IsBreakpointAtThisSite((*pos).second)) {195 // If we're at the right stack depth, then we're done.196 Thread &thread = GetThread();197 bool done;198 StackID frame_zero_id =199 thread.GetStackFrameAtIndex(0)->GetStackID();200 201 if (frame_zero_id == m_stack_id)202 done = true;203 else if (frame_zero_id < m_stack_id)204 done = false;205 else {206 StackFrameSP older_frame_sp = thread.GetStackFrameAtIndex(1);207 208 // But if we can't even unwind one frame we should just get out209 // of here & stop...210 if (older_frame_sp) {211 const SymbolContext &older_context =212 older_frame_sp->GetSymbolContext(eSymbolContextEverything);213 SymbolContext stack_context;214 m_stack_id.GetSymbolContextScope()->CalculateSymbolContext(215 &stack_context);216 217 done = (older_context == stack_context);218 } else219 done = false;220 }221 222 if (done)223 SetPlanComplete();224 else225 m_should_stop = false;226 227 // Otherwise we've hit this breakpoint recursively. If we're the228 // only breakpoint here, then we do explain the stop, and we'll229 // continue. If not then we should let higher plans handle this230 // stop.231 if (this_site->GetNumberOfConstituents() == 1)232 m_explains_stop = true;233 else {234 m_should_stop = true;235 m_explains_stop = false;236 }237 return;238 }239 }240 }241 // If we get here we haven't hit any of our breakpoints, so let the242 // higher plans take care of the stop.243 m_explains_stop = false;244 return;245 } else if (IsUsuallyUnexplainedStopReason(reason)) {246 m_explains_stop = false;247 } else {248 m_explains_stop = true;249 }250 }251}252 253bool ThreadPlanStepUntil::DoPlanExplainsStop(Event *event_ptr) {254 // We don't explain signals or breakpoints (breakpoints that handle stepping255 // in or out will be handled by a child plan.256 AnalyzeStop();257 return m_explains_stop;258}259 260bool ThreadPlanStepUntil::ShouldStop(Event *event_ptr) {261 // If we've told our self in ExplainsStop that we plan to continue, then do262 // so here. Otherwise, as long as this thread has stopped for a reason, we263 // will stop.264 265 StopInfoSP stop_info_sp = GetPrivateStopInfo();266 if (!stop_info_sp || stop_info_sp->GetStopReason() == eStopReasonNone)267 return false;268 269 AnalyzeStop();270 return m_should_stop;271}272 273bool ThreadPlanStepUntil::StopOthers() { return m_stop_others; }274 275StateType ThreadPlanStepUntil::GetPlanRunState() { return eStateRunning; }276 277bool ThreadPlanStepUntil::DoWillResume(StateType resume_state,278 bool current_plan) {279 if (current_plan) {280 Target &target = GetTarget();281 Breakpoint *return_bp = target.GetBreakpointByID(m_return_bp_id).get();282 if (return_bp != nullptr)283 return_bp->SetEnabled(true);284 285 until_collection::iterator pos, end = m_until_points.end();286 for (pos = m_until_points.begin(); pos != end; pos++) {287 Breakpoint *until_bp = target.GetBreakpointByID((*pos).second).get();288 if (until_bp != nullptr)289 until_bp->SetEnabled(true);290 }291 }292 293 m_should_stop = true;294 m_ran_analyze = false;295 m_explains_stop = false;296 return true;297}298 299bool ThreadPlanStepUntil::WillStop() {300 Target &target = GetTarget();301 Breakpoint *return_bp = target.GetBreakpointByID(m_return_bp_id).get();302 if (return_bp != nullptr)303 return_bp->SetEnabled(false);304 305 until_collection::iterator pos, end = m_until_points.end();306 for (pos = m_until_points.begin(); pos != end; pos++) {307 Breakpoint *until_bp = target.GetBreakpointByID((*pos).second).get();308 if (until_bp != nullptr)309 until_bp->SetEnabled(false);310 }311 return true;312}313 314bool ThreadPlanStepUntil::MischiefManaged() {315 // I'm letting "PlanExplainsStop" do all the work, and just reporting that316 // here.317 bool done = false;318 if (IsPlanComplete()) {319 Log *log = GetLog(LLDBLog::Step);320 LLDB_LOGF(log, "Completed step until plan.");321 322 Clear();323 done = true;324 }325 if (done)326 ThreadPlan::MischiefManaged();327 328 return done;329}330