1 //===-- ThreadPlanStepRange.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/ThreadPlanStepRange.h" 10 #include "lldb/Breakpoint/BreakpointLocation.h" 11 #include "lldb/Breakpoint/BreakpointSite.h" 12 #include "lldb/Core/Disassembler.h" 13 #include "lldb/Symbol/Function.h" 14 #include "lldb/Symbol/Symbol.h" 15 #include "lldb/Target/ExecutionContext.h" 16 #include "lldb/Target/Process.h" 17 #include "lldb/Target/RegisterContext.h" 18 #include "lldb/Target/StopInfo.h" 19 #include "lldb/Target/Target.h" 20 #include "lldb/Target/Thread.h" 21 #include "lldb/Target/ThreadPlanRunToAddress.h" 22 #include "lldb/Utility/Log.h" 23 #include "lldb/Utility/Stream.h" 24 25 using namespace lldb; 26 using namespace lldb_private; 27 28 // ThreadPlanStepRange: Step through a stack range, either stepping over or 29 // into based on the value of \a type. 30 31 ThreadPlanStepRange::ThreadPlanStepRange(ThreadPlanKind kind, const char *name, 32 Thread &thread, 33 const AddressRange &range, 34 const SymbolContext &addr_context, 35 lldb::RunMode stop_others, 36 bool given_ranges_only) 37 : ThreadPlan(kind, name, thread, eVoteNoOpinion, eVoteNoOpinion), 38 m_addr_context(addr_context), m_address_ranges(), 39 m_stop_others(stop_others), m_stack_id(), m_parent_stack_id(), 40 m_no_more_plans(false), m_first_run_event(true), m_use_fast_step(false), 41 m_given_ranges_only(given_ranges_only) { 42 m_use_fast_step = GetTarget().GetUseFastStepping(); 43 AddRange(range); 44 m_stack_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 45 StackFrameSP parent_stack = m_thread.GetStackFrameAtIndex(1); 46 if (parent_stack) 47 m_parent_stack_id = parent_stack->GetStackID(); 48 } 49 50 ThreadPlanStepRange::~ThreadPlanStepRange() { ClearNextBranchBreakpoint(); } 51 52 void ThreadPlanStepRange::DidPush() { 53 // See if we can find a "next range" breakpoint: 54 SetNextBranchBreakpoint(); 55 } 56 57 bool ThreadPlanStepRange::ValidatePlan(Stream *error) { 58 if (m_could_not_resolve_hw_bp) { 59 if (error) 60 error->PutCString( 61 "Could not create hardware breakpoint for thread plan."); 62 return false; 63 } 64 return true; 65 } 66 67 Vote ThreadPlanStepRange::ShouldReportStop(Event *event_ptr) { 68 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 69 70 const Vote vote = IsPlanComplete() ? eVoteYes : eVoteNo; 71 LLDB_LOGF(log, "ThreadPlanStepRange::ShouldReportStop() returning vote %i\n", 72 vote); 73 return vote; 74 } 75 76 void ThreadPlanStepRange::AddRange(const AddressRange &new_range) { 77 // For now I'm just adding the ranges. At some point we may want to condense 78 // the ranges if they overlap, though I don't think it is likely to be very 79 // important. 80 m_address_ranges.push_back(new_range); 81 82 // Fill the slot for this address range with an empty DisassemblerSP in the 83 // instruction ranges. I want the indices to match, but I don't want to do 84 // the work to disassemble this range if I don't step into it. 85 m_instruction_ranges.push_back(DisassemblerSP()); 86 } 87 88 void ThreadPlanStepRange::DumpRanges(Stream *s) { 89 size_t num_ranges = m_address_ranges.size(); 90 if (num_ranges == 1) { 91 m_address_ranges[0].Dump(s, m_thread.CalculateTarget().get(), 92 Address::DumpStyleLoadAddress); 93 } else { 94 for (size_t i = 0; i < num_ranges; i++) { 95 s->Printf(" %" PRIu64 ": ", uint64_t(i)); 96 m_address_ranges[i].Dump(s, m_thread.CalculateTarget().get(), 97 Address::DumpStyleLoadAddress); 98 } 99 } 100 } 101 102 bool ThreadPlanStepRange::InRange() { 103 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 104 bool ret_value = false; 105 106 lldb::addr_t pc_load_addr = m_thread.GetRegisterContext()->GetPC(); 107 108 size_t num_ranges = m_address_ranges.size(); 109 for (size_t i = 0; i < num_ranges; i++) { 110 ret_value = m_address_ranges[i].ContainsLoadAddress( 111 pc_load_addr, m_thread.CalculateTarget().get()); 112 if (ret_value) 113 break; 114 } 115 116 if (!ret_value && !m_given_ranges_only) { 117 // See if we've just stepped to another part of the same line number... 118 StackFrame *frame = m_thread.GetStackFrameAtIndex(0).get(); 119 120 SymbolContext new_context( 121 frame->GetSymbolContext(eSymbolContextEverything)); 122 if (m_addr_context.line_entry.IsValid() && 123 new_context.line_entry.IsValid()) { 124 if (m_addr_context.line_entry.original_file == 125 new_context.line_entry.original_file) { 126 if (m_addr_context.line_entry.line == new_context.line_entry.line) { 127 m_addr_context = new_context; 128 const bool include_inlined_functions = 129 GetKind() == eKindStepOverRange; 130 AddRange(m_addr_context.line_entry.GetSameLineContiguousAddressRange( 131 include_inlined_functions)); 132 ret_value = true; 133 if (log) { 134 StreamString s; 135 m_addr_context.line_entry.Dump(&s, m_thread.CalculateTarget().get(), 136 true, Address::DumpStyleLoadAddress, 137 Address::DumpStyleLoadAddress, true); 138 139 LLDB_LOGF( 140 log, 141 "Step range plan stepped to another range of same line: %s", 142 s.GetData()); 143 } 144 } else if (new_context.line_entry.line == 0) { 145 new_context.line_entry.line = m_addr_context.line_entry.line; 146 m_addr_context = new_context; 147 const bool include_inlined_functions = 148 GetKind() == eKindStepOverRange; 149 AddRange(m_addr_context.line_entry.GetSameLineContiguousAddressRange( 150 include_inlined_functions)); 151 ret_value = true; 152 if (log) { 153 StreamString s; 154 m_addr_context.line_entry.Dump(&s, m_thread.CalculateTarget().get(), 155 true, Address::DumpStyleLoadAddress, 156 Address::DumpStyleLoadAddress, true); 157 158 LLDB_LOGF(log, 159 "Step range plan stepped to a range at linenumber 0 " 160 "stepping through that range: %s", 161 s.GetData()); 162 } 163 } else if (new_context.line_entry.range.GetBaseAddress().GetLoadAddress( 164 m_thread.CalculateTarget().get()) != pc_load_addr) { 165 // Another thing that sometimes happens here is that we step out of 166 // one line into the MIDDLE of another line. So far I mostly see 167 // this due to bugs in the debug information. But we probably don't 168 // want to be in the middle of a line range, so in that case reset 169 // the stepping range to the line we've stepped into the middle of 170 // and continue. 171 m_addr_context = new_context; 172 m_address_ranges.clear(); 173 AddRange(m_addr_context.line_entry.range); 174 ret_value = true; 175 if (log) { 176 StreamString s; 177 m_addr_context.line_entry.Dump(&s, m_thread.CalculateTarget().get(), 178 true, Address::DumpStyleLoadAddress, 179 Address::DumpStyleLoadAddress, true); 180 181 LLDB_LOGF(log, 182 "Step range plan stepped to the middle of new " 183 "line(%d): %s, continuing to clear this line.", 184 new_context.line_entry.line, s.GetData()); 185 } 186 } 187 } 188 } 189 } 190 191 if (!ret_value && log) 192 LLDB_LOGF(log, "Step range plan out of range to 0x%" PRIx64, pc_load_addr); 193 194 return ret_value; 195 } 196 197 bool ThreadPlanStepRange::InSymbol() { 198 lldb::addr_t cur_pc = m_thread.GetRegisterContext()->GetPC(); 199 if (m_addr_context.function != nullptr) { 200 return m_addr_context.function->GetAddressRange().ContainsLoadAddress( 201 cur_pc, m_thread.CalculateTarget().get()); 202 } else if (m_addr_context.symbol && m_addr_context.symbol->ValueIsAddress()) { 203 AddressRange range(m_addr_context.symbol->GetAddressRef(), 204 m_addr_context.symbol->GetByteSize()); 205 return range.ContainsLoadAddress(cur_pc, m_thread.CalculateTarget().get()); 206 } 207 return false; 208 } 209 210 // FIXME: This should also handle inlining if we aren't going to do inlining in 211 // the 212 // main stack. 213 // 214 // Ideally we should remember the whole stack frame list, and then compare that 215 // to the current list. 216 217 lldb::FrameComparison ThreadPlanStepRange::CompareCurrentFrameToStartFrame() { 218 FrameComparison frame_order; 219 220 StackID cur_frame_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 221 222 if (cur_frame_id == m_stack_id) { 223 frame_order = eFrameCompareEqual; 224 } else if (cur_frame_id < m_stack_id) { 225 frame_order = eFrameCompareYounger; 226 } else { 227 StackFrameSP cur_parent_frame = m_thread.GetStackFrameAtIndex(1); 228 StackID cur_parent_id; 229 if (cur_parent_frame) 230 cur_parent_id = cur_parent_frame->GetStackID(); 231 if (m_parent_stack_id.IsValid() && cur_parent_id.IsValid() && 232 m_parent_stack_id == cur_parent_id) 233 frame_order = eFrameCompareSameParent; 234 else 235 frame_order = eFrameCompareOlder; 236 } 237 return frame_order; 238 } 239 240 bool ThreadPlanStepRange::StopOthers() { 241 switch (m_stop_others) { 242 case lldb::eOnlyThisThread: 243 return true; 244 case lldb::eOnlyDuringStepping: 245 // If there is a call in the range of the next branch breakpoint, 246 // then we should always run all threads, since a call can execute 247 // arbitrary code which might for instance take a lock that's held 248 // by another thread. 249 return !m_found_calls; 250 case lldb::eAllThreads: 251 return false; 252 } 253 llvm_unreachable("Unhandled run mode!"); 254 } 255 256 InstructionList *ThreadPlanStepRange::GetInstructionsForAddress( 257 lldb::addr_t addr, size_t &range_index, size_t &insn_offset) { 258 size_t num_ranges = m_address_ranges.size(); 259 for (size_t i = 0; i < num_ranges; i++) { 260 if (m_address_ranges[i].ContainsLoadAddress(addr, &GetTarget())) { 261 // Some joker added a zero size range to the stepping range... 262 if (m_address_ranges[i].GetByteSize() == 0) 263 return nullptr; 264 265 if (!m_instruction_ranges[i]) { 266 // Disassemble the address range given: 267 ExecutionContext exe_ctx(m_thread.GetProcess()); 268 const char *plugin_name = nullptr; 269 const char *flavor = nullptr; 270 const bool prefer_file_cache = true; 271 m_instruction_ranges[i] = Disassembler::DisassembleRange( 272 GetTarget().GetArchitecture(), plugin_name, flavor, exe_ctx, 273 m_address_ranges[i], prefer_file_cache); 274 } 275 if (!m_instruction_ranges[i]) 276 return nullptr; 277 else { 278 // Find where we are in the instruction list as well. If we aren't at 279 // an instruction, return nullptr. In this case, we're probably lost, 280 // and shouldn't try to do anything fancy. 281 282 insn_offset = 283 m_instruction_ranges[i] 284 ->GetInstructionList() 285 .GetIndexOfInstructionAtLoadAddress(addr, GetTarget()); 286 if (insn_offset == UINT32_MAX) 287 return nullptr; 288 else { 289 range_index = i; 290 return &m_instruction_ranges[i]->GetInstructionList(); 291 } 292 } 293 } 294 } 295 return nullptr; 296 } 297 298 void ThreadPlanStepRange::ClearNextBranchBreakpoint() { 299 if (m_next_branch_bp_sp) { 300 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 301 LLDB_LOGF(log, "Removing next branch breakpoint: %d.", 302 m_next_branch_bp_sp->GetID()); 303 GetTarget().RemoveBreakpointByID(m_next_branch_bp_sp->GetID()); 304 m_next_branch_bp_sp.reset(); 305 m_could_not_resolve_hw_bp = false; 306 m_found_calls = false; 307 } 308 } 309 310 bool ThreadPlanStepRange::SetNextBranchBreakpoint() { 311 if (m_next_branch_bp_sp) 312 return true; 313 314 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 315 // Stepping through ranges using breakpoints doesn't work yet, but with this 316 // off we fall back to instruction single stepping. 317 if (!m_use_fast_step) 318 return false; 319 320 // clear the m_found_calls, we'll rediscover it for this range. 321 m_found_calls = false; 322 323 lldb::addr_t cur_addr = GetThread().GetRegisterContext()->GetPC(); 324 // Find the current address in our address ranges, and fetch the disassembly 325 // if we haven't already: 326 size_t pc_index; 327 size_t range_index; 328 InstructionList *instructions = 329 GetInstructionsForAddress(cur_addr, range_index, pc_index); 330 if (instructions == nullptr) 331 return false; 332 else { 333 Target &target = GetThread().GetProcess()->GetTarget(); 334 const bool ignore_calls = GetKind() == eKindStepOverRange; 335 uint32_t branch_index = 336 instructions->GetIndexOfNextBranchInstruction(pc_index, target, 337 ignore_calls, 338 &m_found_calls); 339 340 Address run_to_address; 341 342 // If we didn't find a branch, run to the end of the range. 343 if (branch_index == UINT32_MAX) { 344 uint32_t last_index = instructions->GetSize() - 1; 345 if (last_index - pc_index > 1) { 346 InstructionSP last_inst = 347 instructions->GetInstructionAtIndex(last_index); 348 size_t last_inst_size = last_inst->GetOpcode().GetByteSize(); 349 run_to_address = last_inst->GetAddress(); 350 run_to_address.Slide(last_inst_size); 351 } 352 } else if (branch_index - pc_index > 1) { 353 run_to_address = 354 instructions->GetInstructionAtIndex(branch_index)->GetAddress(); 355 } 356 357 if (run_to_address.IsValid()) { 358 const bool is_internal = true; 359 m_next_branch_bp_sp = 360 GetTarget().CreateBreakpoint(run_to_address, is_internal, false); 361 if (m_next_branch_bp_sp) { 362 363 if (m_next_branch_bp_sp->IsHardware() && 364 !m_next_branch_bp_sp->HasResolvedLocations()) 365 m_could_not_resolve_hw_bp = true; 366 367 if (log) { 368 lldb::break_id_t bp_site_id = LLDB_INVALID_BREAK_ID; 369 BreakpointLocationSP bp_loc = 370 m_next_branch_bp_sp->GetLocationAtIndex(0); 371 if (bp_loc) { 372 BreakpointSiteSP bp_site = bp_loc->GetBreakpointSite(); 373 if (bp_site) { 374 bp_site_id = bp_site->GetID(); 375 } 376 } 377 LLDB_LOGF(log, 378 "ThreadPlanStepRange::SetNextBranchBreakpoint - Setting " 379 "breakpoint %d (site %d) to run to address 0x%" PRIx64, 380 m_next_branch_bp_sp->GetID(), bp_site_id, 381 run_to_address.GetLoadAddress( 382 &m_thread.GetProcess()->GetTarget())); 383 } 384 385 m_next_branch_bp_sp->SetThreadID(m_thread.GetID()); 386 m_next_branch_bp_sp->SetBreakpointKind("next-branch-location"); 387 388 return true; 389 } else 390 return false; 391 } 392 } 393 return false; 394 } 395 396 bool ThreadPlanStepRange::NextRangeBreakpointExplainsStop( 397 lldb::StopInfoSP stop_info_sp) { 398 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 399 if (!m_next_branch_bp_sp) 400 return false; 401 402 break_id_t bp_site_id = stop_info_sp->GetValue(); 403 BreakpointSiteSP bp_site_sp = 404 m_thread.GetProcess()->GetBreakpointSiteList().FindByID(bp_site_id); 405 if (!bp_site_sp) 406 return false; 407 else if (!bp_site_sp->IsBreakpointAtThisSite(m_next_branch_bp_sp->GetID())) 408 return false; 409 else { 410 // If we've hit the next branch breakpoint, then clear it. 411 size_t num_owners = bp_site_sp->GetNumberOfOwners(); 412 bool explains_stop = true; 413 // If all the owners are internal, then we are probably just stepping over 414 // this range from multiple threads, or multiple frames, so we want to 415 // continue. If one is not internal, then we should not explain the stop, 416 // and let the user breakpoint handle the stop. 417 for (size_t i = 0; i < num_owners; i++) { 418 if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal()) { 419 explains_stop = false; 420 break; 421 } 422 } 423 LLDB_LOGF(log, 424 "ThreadPlanStepRange::NextRangeBreakpointExplainsStop - Hit " 425 "next range breakpoint which has %" PRIu64 426 " owners - explains stop: %u.", 427 (uint64_t)num_owners, explains_stop); 428 ClearNextBranchBreakpoint(); 429 return explains_stop; 430 } 431 } 432 433 bool ThreadPlanStepRange::WillStop() { return true; } 434 435 StateType ThreadPlanStepRange::GetPlanRunState() { 436 if (m_next_branch_bp_sp) 437 return eStateRunning; 438 else 439 return eStateStepping; 440 } 441 442 bool ThreadPlanStepRange::MischiefManaged() { 443 // If we have pushed some plans between ShouldStop & MischiefManaged, then 444 // we're not done... 445 // I do this check first because we might have stepped somewhere that will 446 // fool InRange into 447 // thinking it needs to step past the end of that line. This happens, for 448 // instance, when stepping over inlined code that is in the middle of the 449 // current line. 450 451 if (!m_no_more_plans) 452 return false; 453 454 bool done = true; 455 if (!IsPlanComplete()) { 456 if (InRange()) { 457 done = false; 458 } else { 459 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 460 done = (frame_order != eFrameCompareOlder) ? m_no_more_plans : true; 461 } 462 } 463 464 if (done) { 465 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 466 LLDB_LOGF(log, "Completed step through range plan."); 467 ClearNextBranchBreakpoint(); 468 ThreadPlan::MischiefManaged(); 469 return true; 470 } else { 471 return false; 472 } 473 } 474 475 bool ThreadPlanStepRange::IsPlanStale() { 476 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 477 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 478 479 if (frame_order == eFrameCompareOlder) { 480 if (log) { 481 LLDB_LOGF(log, "ThreadPlanStepRange::IsPlanStale returning true, we've " 482 "stepped out."); 483 } 484 return true; 485 } else if (frame_order == eFrameCompareEqual && InSymbol()) { 486 // If we are not in a place we should step through, we've gotten stale. One 487 // tricky bit here is that some stubs don't push a frame, so we should. 488 // check that we are in the same symbol. 489 if (!InRange()) { 490 // Set plan Complete when we reach next instruction just after the range 491 lldb::addr_t addr = m_thread.GetRegisterContext()->GetPC() - 1; 492 size_t num_ranges = m_address_ranges.size(); 493 for (size_t i = 0; i < num_ranges; i++) { 494 bool in_range = m_address_ranges[i].ContainsLoadAddress( 495 addr, m_thread.CalculateTarget().get()); 496 if (in_range) { 497 SetPlanComplete(); 498 } 499 } 500 return true; 501 } 502 } 503 return false; 504 } 505