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