1 //===-- ThreadPlanStepRange.cpp ---------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "lldb/Target/ThreadPlanStepRange.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 #include "lldb/Breakpoint/BreakpointLocation.h" 17 #include "lldb/Breakpoint/BreakpointSite.h" 18 #include "lldb/Core/Disassembler.h" 19 #include "lldb/Core/Log.h" 20 #include "lldb/Core/Stream.h" 21 #include "lldb/Symbol/Function.h" 22 #include "lldb/Symbol/Symbol.h" 23 #include "lldb/Target/ExecutionContext.h" 24 #include "lldb/Target/Process.h" 25 #include "lldb/Target/RegisterContext.h" 26 #include "lldb/Target/StopInfo.h" 27 #include "lldb/Target/Target.h" 28 #include "lldb/Target/Thread.h" 29 #include "lldb/Target/ThreadPlanRunToAddress.h" 30 31 using namespace lldb; 32 using namespace lldb_private; 33 34 35 //---------------------------------------------------------------------- 36 // ThreadPlanStepRange: Step through a stack range, either stepping over or into 37 // based on the value of \a type. 38 //---------------------------------------------------------------------- 39 40 ThreadPlanStepRange::ThreadPlanStepRange (ThreadPlanKind kind, 41 const char *name, 42 Thread &thread, 43 const AddressRange &range, 44 const SymbolContext &addr_context, 45 lldb::RunMode stop_others, 46 bool given_ranges_only) : 47 ThreadPlan (kind, name, thread, eVoteNoOpinion, eVoteNoOpinion), 48 m_addr_context (addr_context), 49 m_address_ranges (), 50 m_stop_others (stop_others), 51 m_stack_id (), 52 m_parent_stack_id(), 53 m_no_more_plans (false), 54 m_first_run_event (true), 55 m_use_fast_step(false), 56 m_given_ranges_only (given_ranges_only) 57 { 58 m_use_fast_step = GetTarget().GetUseFastStepping(); 59 AddRange(range); 60 m_stack_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 61 StackFrameSP parent_stack = m_thread.GetStackFrameAtIndex(1); 62 if (parent_stack) 63 m_parent_stack_id = parent_stack->GetStackID(); 64 } 65 66 ThreadPlanStepRange::~ThreadPlanStepRange () 67 { 68 ClearNextBranchBreakpoint(); 69 70 size_t num_instruction_ranges = m_instruction_ranges.size(); 71 72 // FIXME: The DisassemblerLLVMC has a reference cycle and won't go away if it has any active instructions. 73 // I'll fix that but for now, just clear the list and it will go away nicely. 74 for (size_t i = 0; i < num_instruction_ranges; i++) 75 { 76 if (m_instruction_ranges[i]) 77 m_instruction_ranges[i]->GetInstructionList().Clear(); 78 } 79 } 80 81 void 82 ThreadPlanStepRange::DidPush () 83 { 84 // See if we can find a "next range" breakpoint: 85 SetNextBranchBreakpoint(); 86 } 87 88 bool 89 ThreadPlanStepRange::ValidatePlan (Stream *error) 90 { 91 return true; 92 } 93 94 Vote 95 ThreadPlanStepRange::ShouldReportStop (Event *event_ptr) 96 { 97 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 98 99 const Vote vote = IsPlanComplete() ? eVoteYes : eVoteNo; 100 if (log) 101 log->Printf ("ThreadPlanStepRange::ShouldReportStop() returning vote %i\n", vote); 102 return vote; 103 } 104 105 void 106 ThreadPlanStepRange::AddRange(const AddressRange &new_range) 107 { 108 // For now I'm just adding the ranges. At some point we may want to 109 // condense the ranges if they overlap, though I don't think it is likely 110 // to be very important. 111 m_address_ranges.push_back (new_range); 112 113 // Fill the slot for this address range with an empty DisassemblerSP in the instruction ranges. I want the 114 // indices to match, but I don't want to do the work to disassemble this range if I don't step into it. 115 m_instruction_ranges.push_back (DisassemblerSP()); 116 } 117 118 void 119 ThreadPlanStepRange::DumpRanges(Stream *s) 120 { 121 size_t num_ranges = m_address_ranges.size(); 122 if (num_ranges == 1) 123 { 124 m_address_ranges[0].Dump (s, m_thread.CalculateTarget().get(), Address::DumpStyleLoadAddress); 125 } 126 else 127 { 128 for (size_t i = 0; i < num_ranges; i++) 129 { 130 s->Printf(" %" PRIu64 ": ", uint64_t(i)); 131 m_address_ranges[i].Dump (s, m_thread.CalculateTarget().get(), Address::DumpStyleLoadAddress); 132 } 133 } 134 } 135 136 bool 137 ThreadPlanStepRange::InRange () 138 { 139 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 140 bool ret_value = false; 141 142 lldb::addr_t pc_load_addr = m_thread.GetRegisterContext()->GetPC(); 143 144 size_t num_ranges = m_address_ranges.size(); 145 for (size_t i = 0; i < num_ranges; i++) 146 { 147 ret_value = m_address_ranges[i].ContainsLoadAddress(pc_load_addr, m_thread.CalculateTarget().get()); 148 if (ret_value) 149 break; 150 } 151 152 if (!ret_value && !m_given_ranges_only) 153 { 154 // See if we've just stepped to another part of the same line number... 155 StackFrame *frame = m_thread.GetStackFrameAtIndex(0).get(); 156 157 SymbolContext new_context(frame->GetSymbolContext(eSymbolContextEverything)); 158 if (m_addr_context.line_entry.IsValid() && new_context.line_entry.IsValid()) 159 { 160 if (m_addr_context.line_entry.file == new_context.line_entry.file) 161 { 162 if (m_addr_context.line_entry.line == new_context.line_entry.line) 163 { 164 m_addr_context = new_context; 165 AddRange(m_addr_context.line_entry.range); 166 ret_value = true; 167 if (log) 168 { 169 StreamString s; 170 m_addr_context.line_entry.Dump (&s, 171 m_thread.CalculateTarget().get(), 172 true, 173 Address::DumpStyleLoadAddress, 174 Address::DumpStyleLoadAddress, 175 true); 176 177 log->Printf ("Step range plan stepped to another range of same line: %s", s.GetData()); 178 } 179 } 180 else if (new_context.line_entry.line == 0) 181 { 182 new_context.line_entry.line = m_addr_context.line_entry.line; 183 m_addr_context = new_context; 184 AddRange(m_addr_context.line_entry.range); 185 ret_value = true; 186 if (log) 187 { 188 StreamString s; 189 m_addr_context.line_entry.Dump (&s, 190 m_thread.CalculateTarget().get(), 191 true, 192 Address::DumpStyleLoadAddress, 193 Address::DumpStyleLoadAddress, 194 true); 195 196 log->Printf ("Step range plan stepped to a range at linenumber 0 stepping through that range: %s", s.GetData()); 197 } 198 } 199 else if (new_context.line_entry.range.GetBaseAddress().GetLoadAddress(m_thread.CalculateTarget().get()) 200 != pc_load_addr) 201 { 202 // Another thing that sometimes happens here is that we step out of one line into the MIDDLE of another 203 // line. So far I mostly see this due to bugs in the debug information. 204 // But we probably don't want to be in the middle of a line range, so in that case reset the stepping 205 // range to the line we've stepped into the middle of and continue. 206 m_addr_context = new_context; 207 m_address_ranges.clear(); 208 AddRange(m_addr_context.line_entry.range); 209 ret_value = true; 210 if (log) 211 { 212 StreamString s; 213 m_addr_context.line_entry.Dump (&s, 214 m_thread.CalculateTarget().get(), 215 true, 216 Address::DumpStyleLoadAddress, 217 Address::DumpStyleLoadAddress, 218 true); 219 220 log->Printf ("Step range plan stepped to the middle of new line(%d): %s, continuing to clear this line.", 221 new_context.line_entry.line, 222 s.GetData()); 223 } 224 225 } 226 } 227 228 } 229 230 } 231 232 if (!ret_value && log) 233 log->Printf ("Step range plan out of range to 0x%" PRIx64, pc_load_addr); 234 235 return ret_value; 236 } 237 238 bool 239 ThreadPlanStepRange::InSymbol() 240 { 241 lldb::addr_t cur_pc = m_thread.GetRegisterContext()->GetPC(); 242 if (m_addr_context.function != NULL) 243 { 244 return m_addr_context.function->GetAddressRange().ContainsLoadAddress (cur_pc, m_thread.CalculateTarget().get()); 245 } 246 else if (m_addr_context.symbol && m_addr_context.symbol->ValueIsAddress()) 247 { 248 AddressRange range(m_addr_context.symbol->GetAddressRef(), m_addr_context.symbol->GetByteSize()); 249 return range.ContainsLoadAddress (cur_pc, m_thread.CalculateTarget().get()); 250 } 251 return false; 252 } 253 254 // FIXME: This should also handle inlining if we aren't going to do inlining in the 255 // main stack. 256 // 257 // Ideally we should remember the whole stack frame list, and then compare that 258 // to the current list. 259 260 lldb::FrameComparison 261 ThreadPlanStepRange::CompareCurrentFrameToStartFrame() 262 { 263 FrameComparison frame_order; 264 265 StackID cur_frame_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 266 267 if (cur_frame_id == m_stack_id) 268 { 269 frame_order = eFrameCompareEqual; 270 } 271 else if (cur_frame_id < m_stack_id) 272 { 273 frame_order = eFrameCompareYounger; 274 } 275 else 276 { 277 StackFrameSP cur_parent_frame = m_thread.GetStackFrameAtIndex(1); 278 StackID cur_parent_id; 279 if (cur_parent_frame) 280 cur_parent_id = cur_parent_frame->GetStackID(); 281 if (m_parent_stack_id.IsValid() 282 && cur_parent_id.IsValid() 283 && m_parent_stack_id == cur_parent_id) 284 frame_order = eFrameCompareSameParent; 285 else 286 frame_order = eFrameCompareOlder; 287 } 288 return frame_order; 289 } 290 291 bool 292 ThreadPlanStepRange::StopOthers () 293 { 294 if (m_stop_others == lldb::eOnlyThisThread 295 || m_stop_others == lldb::eOnlyDuringStepping) 296 return true; 297 else 298 return false; 299 } 300 301 InstructionList * 302 ThreadPlanStepRange::GetInstructionsForAddress(lldb::addr_t addr, size_t &range_index, size_t &insn_offset) 303 { 304 size_t num_ranges = m_address_ranges.size(); 305 for (size_t i = 0; i < num_ranges; i++) 306 { 307 if (m_address_ranges[i].ContainsLoadAddress(addr, &GetTarget())) 308 { 309 // Some joker added a zero size range to the stepping range... 310 if (m_address_ranges[i].GetByteSize() == 0) 311 return NULL; 312 313 if (!m_instruction_ranges[i]) 314 { 315 //Disassemble the address range given: 316 ExecutionContext exe_ctx (m_thread.GetProcess()); 317 const char *plugin_name = NULL; 318 const char *flavor = NULL; 319 const bool prefer_file_cache = true; 320 m_instruction_ranges[i] = Disassembler::DisassembleRange(GetTarget().GetArchitecture(), 321 plugin_name, 322 flavor, 323 exe_ctx, 324 m_address_ranges[i], 325 prefer_file_cache); 326 327 } 328 if (!m_instruction_ranges[i]) 329 return NULL; 330 else 331 { 332 // Find where we are in the instruction list as well. If we aren't at an instruction, 333 // return NULL. In this case, we're probably lost, and shouldn't try to do anything fancy. 334 335 insn_offset = m_instruction_ranges[i]->GetInstructionList().GetIndexOfInstructionAtLoadAddress(addr, GetTarget()); 336 if (insn_offset == UINT32_MAX) 337 return NULL; 338 else 339 { 340 range_index = i; 341 return &m_instruction_ranges[i]->GetInstructionList(); 342 } 343 } 344 } 345 } 346 return NULL; 347 } 348 349 void 350 ThreadPlanStepRange::ClearNextBranchBreakpoint() 351 { 352 if (m_next_branch_bp_sp) 353 { 354 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 355 if (log) 356 log->Printf ("Removing next branch breakpoint: %d.", m_next_branch_bp_sp->GetID()); 357 GetTarget().RemoveBreakpointByID (m_next_branch_bp_sp->GetID()); 358 m_next_branch_bp_sp.reset(); 359 } 360 } 361 362 bool 363 ThreadPlanStepRange::SetNextBranchBreakpoint () 364 { 365 if (m_next_branch_bp_sp) 366 return true; 367 368 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 369 // Stepping through ranges using breakpoints doesn't work yet, but with this off we fall back to instruction 370 // single stepping. 371 if (!m_use_fast_step) 372 return false; 373 374 lldb::addr_t cur_addr = GetThread().GetRegisterContext()->GetPC(); 375 // Find the current address in our address ranges, and fetch the disassembly if we haven't already: 376 size_t pc_index; 377 size_t range_index; 378 InstructionList *instructions = GetInstructionsForAddress (cur_addr, range_index, pc_index); 379 if (instructions == NULL) 380 return false; 381 else 382 { 383 Target &target = GetThread().GetProcess()->GetTarget(); 384 uint32_t branch_index; 385 branch_index = instructions->GetIndexOfNextBranchInstruction (pc_index, target); 386 387 Address run_to_address; 388 389 // If we didn't find a branch, run to the end of the range. 390 if (branch_index == UINT32_MAX) 391 { 392 uint32_t last_index = instructions->GetSize() - 1; 393 if (last_index - pc_index > 1) 394 { 395 InstructionSP last_inst = instructions->GetInstructionAtIndex(last_index); 396 size_t last_inst_size = last_inst->GetOpcode().GetByteSize(); 397 run_to_address = last_inst->GetAddress(); 398 run_to_address.Slide(last_inst_size); 399 } 400 } 401 else if (branch_index - pc_index > 1) 402 { 403 run_to_address = instructions->GetInstructionAtIndex(branch_index)->GetAddress(); 404 } 405 406 if (run_to_address.IsValid()) 407 { 408 const bool is_internal = true; 409 m_next_branch_bp_sp = GetTarget().CreateBreakpoint(run_to_address, is_internal, false); 410 if (m_next_branch_bp_sp) 411 { 412 if (log) 413 { 414 lldb::break_id_t bp_site_id = LLDB_INVALID_BREAK_ID; 415 BreakpointLocationSP bp_loc = m_next_branch_bp_sp->GetLocationAtIndex(0); 416 if (bp_loc) 417 { 418 BreakpointSiteSP bp_site = bp_loc->GetBreakpointSite(); 419 if (bp_site) 420 { 421 bp_site_id = bp_site->GetID(); 422 } 423 } 424 log->Printf ("ThreadPlanStepRange::SetNextBranchBreakpoint - Setting breakpoint %d (site %d) to run to address 0x%" PRIx64, 425 m_next_branch_bp_sp->GetID(), 426 bp_site_id, 427 run_to_address.GetLoadAddress(&m_thread.GetProcess()->GetTarget())); 428 } 429 m_next_branch_bp_sp->SetThreadID(m_thread.GetID()); 430 m_next_branch_bp_sp->SetBreakpointKind ("next-branch-location"); 431 return true; 432 } 433 else 434 return false; 435 } 436 } 437 return false; 438 } 439 440 bool 441 ThreadPlanStepRange::NextRangeBreakpointExplainsStop (lldb::StopInfoSP stop_info_sp) 442 { 443 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 444 if (!m_next_branch_bp_sp) 445 return false; 446 447 break_id_t bp_site_id = stop_info_sp->GetValue(); 448 BreakpointSiteSP bp_site_sp = m_thread.GetProcess()->GetBreakpointSiteList().FindByID(bp_site_id); 449 if (!bp_site_sp) 450 return false; 451 else if (!bp_site_sp->IsBreakpointAtThisSite (m_next_branch_bp_sp->GetID())) 452 return false; 453 else 454 { 455 // If we've hit the next branch breakpoint, then clear it. 456 size_t num_owners = bp_site_sp->GetNumberOfOwners(); 457 bool explains_stop = true; 458 // If all the owners are internal, then we are probably just stepping over this range from multiple threads, 459 // or multiple frames, so we want to continue. If one is not internal, then we should not explain the stop, 460 // and let the user breakpoint handle the stop. 461 for (size_t i = 0; i < num_owners; i++) 462 { 463 if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal()) 464 { 465 explains_stop = false; 466 break; 467 } 468 } 469 if (log) 470 log->Printf ("ThreadPlanStepRange::NextRangeBreakpointExplainsStop - Hit next range breakpoint which has %" PRIu64 " owners - explains stop: %u.", 471 (uint64_t)num_owners, 472 explains_stop); 473 ClearNextBranchBreakpoint(); 474 return explains_stop; 475 } 476 } 477 478 bool 479 ThreadPlanStepRange::WillStop () 480 { 481 return true; 482 } 483 484 StateType 485 ThreadPlanStepRange::GetPlanRunState () 486 { 487 if (m_next_branch_bp_sp) 488 return eStateRunning; 489 else 490 return eStateStepping; 491 } 492 493 bool 494 ThreadPlanStepRange::MischiefManaged () 495 { 496 // If we have pushed some plans between ShouldStop & MischiefManaged, then we're not done... 497 // I do this check first because we might have stepped somewhere that will fool InRange into 498 // thinking it needs to step past the end of that line. This happens, for instance, when stepping 499 // over inlined code that is in the middle of the current line. 500 501 if (!m_no_more_plans) 502 return false; 503 504 bool done = true; 505 if (!IsPlanComplete()) 506 { 507 if (InRange()) 508 { 509 done = false; 510 } 511 else 512 { 513 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 514 if (frame_order != eFrameCompareOlder) 515 { 516 if (m_no_more_plans) 517 done = true; 518 else 519 done = false; 520 } 521 else 522 done = true; 523 } 524 } 525 526 if (done) 527 { 528 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 529 if (log) 530 log->Printf("Completed step through range plan."); 531 ClearNextBranchBreakpoint(); 532 ThreadPlan::MischiefManaged (); 533 return true; 534 } 535 else 536 { 537 return false; 538 } 539 540 } 541 542 bool 543 ThreadPlanStepRange::IsPlanStale () 544 { 545 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 546 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 547 548 if (frame_order == eFrameCompareOlder) 549 { 550 if (log) 551 { 552 log->Printf("ThreadPlanStepRange::IsPlanStale returning true, we've stepped out."); 553 } 554 return true; 555 } 556 else if (frame_order == eFrameCompareEqual && InSymbol()) 557 { 558 // If we are not in a place we should step through, we've gotten stale. 559 // One tricky bit here is that some stubs don't push a frame, so we should. 560 // check that we are in the same symbol. 561 if (!InRange()) 562 { 563 return true; 564 } 565 } 566 return false; 567 } 568