1//===-- ThreadPlanStepUntil.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/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/Log.h" 18 19using namespace lldb; 20using namespace lldb_private; 21 22// ThreadPlanStepUntil: Run until we reach a given line number or step out of 23// the current frame 24 25ThreadPlanStepUntil::ThreadPlanStepUntil(Thread &thread, 26 lldb::addr_t *address_list, 27 size_t num_addresses, bool stop_others, 28 uint32_t frame_idx) 29 : ThreadPlan(ThreadPlan::eKindStepUntil, "Step until", thread, 30 eVoteNoOpinion, eVoteNoOpinion), 31 m_step_from_insn(LLDB_INVALID_ADDRESS), 32 m_return_bp_id(LLDB_INVALID_BREAK_ID), 33 m_return_addr(LLDB_INVALID_ADDRESS), m_stepped_out(false), 34 m_should_stop(false), m_ran_analyze(false), m_explains_stop(false), 35 m_until_points(), m_stop_others(stop_others) { 36 // Stash away our "until" addresses: 37 TargetSP target_sp(m_thread.CalculateTarget()); 38 39 StackFrameSP frame_sp(m_thread.GetStackFrameAtIndex(frame_idx)); 40 if (frame_sp) { 41 m_step_from_insn = frame_sp->GetStackID().GetPC(); 42 lldb::user_id_t thread_id = m_thread.GetID(); 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(m_thread.GetStackFrameAtIndex(frame_idx + 1)); 48 if (return_frame_sp) { 49 // TODO: add inline functionality 50 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(thread_id); 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(thread_id); 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 TargetSP target_sp(m_thread.CalculateTarget()); 84 if (target_sp) { 85 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) { 86 target_sp->RemoveBreakpointByID(m_return_bp_id); 87 m_return_bp_id = LLDB_INVALID_BREAK_ID; 88 } 89 90 until_collection::iterator pos, end = m_until_points.end(); 91 for (pos = m_until_points.begin(); pos != end; pos++) { 92 target_sp->RemoveBreakpointByID((*pos).second); 93 } 94 } 95 m_until_points.clear(); 96 m_could_not_resolve_hw_bp = false; 97} 98 99void ThreadPlanStepUntil::GetDescription(Stream *s, 100 lldb::DescriptionLevel level) { 101 if (level == lldb::eDescriptionLevelBrief) { 102 s->Printf("step until"); 103 if (m_stepped_out) 104 s->Printf(" - stepped out"); 105 } else { 106 if (m_until_points.size() == 1) 107 s->Printf("Stepping from address 0x%" PRIx64 " until we reach 0x%" PRIx64 108 " using breakpoint %d", 109 (uint64_t)m_step_from_insn, 110 (uint64_t)(*m_until_points.begin()).first, 111 (*m_until_points.begin()).second); 112 else { 113 until_collection::iterator pos, end = m_until_points.end(); 114 s->Printf("Stepping from address 0x%" PRIx64 " until we reach one of:", 115 (uint64_t)m_step_from_insn); 116 for (pos = m_until_points.begin(); pos != end; pos++) { 117 s->Printf("\n\t0x%" PRIx64 " (bp: %d)", (uint64_t)(*pos).first, 118 (*pos).second); 119 } 120 } 121 s->Printf(" stepped out address is 0x%" PRIx64 ".", 122 (uint64_t)m_return_addr); 123 } 124} 125 126bool ThreadPlanStepUntil::ValidatePlan(Stream *error) { 127 if (m_could_not_resolve_hw_bp) { 128 if (error) 129 error->PutCString( 130 "Could not create hardware breakpoint for thread plan."); 131 return false; 132 } else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) { 133 if (error) 134 error->PutCString("Could not create return breakpoint."); 135 return false; 136 } else { 137 until_collection::iterator pos, end = m_until_points.end(); 138 for (pos = m_until_points.begin(); pos != end; pos++) { 139 if (!LLDB_BREAK_ID_IS_VALID((*pos).second)) 140 return false; 141 } 142 return true; 143 } 144} 145 146void ThreadPlanStepUntil::AnalyzeStop() { 147 if (m_ran_analyze) 148 return; 149 150 StopInfoSP stop_info_sp = GetPrivateStopInfo(); 151 m_should_stop = true; 152 m_explains_stop = false; 153 154 if (stop_info_sp) { 155 StopReason reason = stop_info_sp->GetStopReason(); 156 157 if (reason == eStopReasonBreakpoint) { 158 // If this is OUR breakpoint, we're fine, otherwise we don't know why 159 // this happened... 160 BreakpointSiteSP this_site = 161 m_thread.GetProcess()->GetBreakpointSiteList().FindByID( 162 stop_info_sp->GetValue()); 163 if (!this_site) { 164 m_explains_stop = false; 165 return; 166 } 167 168 if (this_site->IsBreakpointAtThisSite(m_return_bp_id)) { 169 // If we are at our "step out" breakpoint, and the stack depth has 170 // shrunk, then this is indeed our stop. If the stack depth has grown, 171 // then we've hit our step out breakpoint recursively. If we are the 172 // only breakpoint at that location, then we do explain the stop, and 173 // we'll just continue. If there was another breakpoint here, then we 174 // don't explain the stop, but we won't mark ourselves Completed, 175 // because maybe that breakpoint will continue, and then we'll finish 176 // the "until". 177 bool done; 178 StackID cur_frame_zero_id; 179 180 done = (m_stack_id < cur_frame_zero_id); 181 182 if (done) { 183 m_stepped_out = true; 184 SetPlanComplete(); 185 } else 186 m_should_stop = false; 187 188 if (this_site->GetNumberOfOwners() == 1) 189 m_explains_stop = true; 190 else 191 m_explains_stop = false; 192 return; 193 } else { 194 // Check if we've hit one of our "until" breakpoints. 195 until_collection::iterator pos, end = m_until_points.end(); 196 for (pos = m_until_points.begin(); pos != end; pos++) { 197 if (this_site->IsBreakpointAtThisSite((*pos).second)) { 198 // If we're at the right stack depth, then we're done. 199 200 bool done; 201 StackID frame_zero_id = 202 m_thread.GetStackFrameAtIndex(0)->GetStackID(); 203 204 if (frame_zero_id == m_stack_id) 205 done = true; 206 else if (frame_zero_id < m_stack_id) 207 done = false; 208 else { 209 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(1); 210 211 // But if we can't even unwind one frame we should just get out 212 // of here & stop... 213 if (older_frame_sp) { 214 const SymbolContext &older_context = 215 older_frame_sp->GetSymbolContext(eSymbolContextEverything); 216 SymbolContext stack_context; 217 m_stack_id.GetSymbolContextScope()->CalculateSymbolContext( 218 &stack_context); 219 220 done = (older_context == stack_context); 221 } else 222 done = false; 223 } 224 225 if (done) 226 SetPlanComplete(); 227 else 228 m_should_stop = false; 229 230 // Otherwise we've hit this breakpoint recursively. If we're the 231 // only breakpoint here, then we do explain the stop, and we'll 232 // continue. If not then we should let higher plans handle this 233 // stop. 234 if (this_site->GetNumberOfOwners() == 1) 235 m_explains_stop = true; 236 else { 237 m_should_stop = true; 238 m_explains_stop = false; 239 } 240 return; 241 } 242 } 243 } 244 // If we get here we haven't hit any of our breakpoints, so let the 245 // higher plans take care of the stop. 246 m_explains_stop = false; 247 return; 248 } else if (IsUsuallyUnexplainedStopReason(reason)) { 249 m_explains_stop = false; 250 } else { 251 m_explains_stop = true; 252 } 253 } 254} 255 256bool ThreadPlanStepUntil::DoPlanExplainsStop(Event *event_ptr) { 257 // We don't explain signals or breakpoints (breakpoints that handle stepping 258 // in or out will be handled by a child plan. 259 AnalyzeStop(); 260 return m_explains_stop; 261} 262 263bool ThreadPlanStepUntil::ShouldStop(Event *event_ptr) { 264 // If we've told our self in ExplainsStop that we plan to continue, then do 265 // so here. Otherwise, as long as this thread has stopped for a reason, we 266 // will stop. 267 268 StopInfoSP stop_info_sp = GetPrivateStopInfo(); 269 if (!stop_info_sp || stop_info_sp->GetStopReason() == eStopReasonNone) 270 return false; 271 272 AnalyzeStop(); 273 return m_should_stop; 274} 275 276bool ThreadPlanStepUntil::StopOthers() { return m_stop_others; } 277 278StateType ThreadPlanStepUntil::GetPlanRunState() { return eStateRunning; } 279 280bool ThreadPlanStepUntil::DoWillResume(StateType resume_state, 281 bool current_plan) { 282 if (current_plan) { 283 TargetSP target_sp(m_thread.CalculateTarget()); 284 if (target_sp) { 285 Breakpoint *return_bp = 286 target_sp->GetBreakpointByID(m_return_bp_id).get(); 287 if (return_bp != nullptr) 288 return_bp->SetEnabled(true); 289 290 until_collection::iterator pos, end = m_until_points.end(); 291 for (pos = m_until_points.begin(); pos != end; pos++) { 292 Breakpoint *until_bp = 293 target_sp->GetBreakpointByID((*pos).second).get(); 294 if (until_bp != nullptr) 295 until_bp->SetEnabled(true); 296 } 297 } 298 } 299 300 m_should_stop = true; 301 m_ran_analyze = false; 302 m_explains_stop = false; 303 return true; 304} 305 306bool ThreadPlanStepUntil::WillStop() { 307 TargetSP target_sp(m_thread.CalculateTarget()); 308 if (target_sp) { 309 Breakpoint *return_bp = target_sp->GetBreakpointByID(m_return_bp_id).get(); 310 if (return_bp != nullptr) 311 return_bp->SetEnabled(false); 312 313 until_collection::iterator pos, end = m_until_points.end(); 314 for (pos = m_until_points.begin(); pos != end; pos++) { 315 Breakpoint *until_bp = target_sp->GetBreakpointByID((*pos).second).get(); 316 if (until_bp != nullptr) 317 until_bp->SetEnabled(false); 318 } 319 } 320 return true; 321} 322 323bool ThreadPlanStepUntil::MischiefManaged() { 324 // I'm letting "PlanExplainsStop" do all the work, and just reporting that 325 // here. 326 bool done = false; 327 if (IsPlanComplete()) { 328 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 329 LLDB_LOGF(log, "Completed step until plan."); 330 331 Clear(); 332 done = true; 333 } 334 if (done) 335 ThreadPlan::MischiefManaged(); 336 337 return done; 338} 339