1 //===- DWARFDebugLine.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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h" 10 #include "llvm/ADT/Optional.h" 11 #include "llvm/ADT/SmallString.h" 12 #include "llvm/ADT/SmallVector.h" 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/BinaryFormat/Dwarf.h" 15 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h" 16 #include "llvm/DebugInfo/DWARF/DWARFDie.h" 17 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 18 #include "llvm/Support/Errc.h" 19 #include "llvm/Support/Format.h" 20 #include "llvm/Support/FormatVariadic.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <algorithm> 23 #include <cassert> 24 #include <cinttypes> 25 #include <cstdint> 26 #include <cstdio> 27 #include <utility> 28 29 using namespace llvm; 30 using namespace dwarf; 31 32 namespace llvm { 33 class DwarfContext; 34 } 35 36 using FileLineInfoKind = DILineInfoSpecifier::FileLineInfoKind; 37 38 namespace { 39 40 struct ContentDescriptor { 41 dwarf::LineNumberEntryFormat Type; 42 dwarf::Form Form; 43 }; 44 45 using ContentDescriptors = SmallVector<ContentDescriptor, 4>; 46 47 } // end anonymous namespace 48 49 static bool versionIsSupported(uint16_t Version) { 50 return Version >= 2 && Version <= 5; 51 } 52 53 void DWARFDebugLine::ContentTypeTracker::trackContentType( 54 dwarf::LineNumberEntryFormat ContentType) { 55 switch (ContentType) { 56 case dwarf::DW_LNCT_timestamp: 57 HasModTime = true; 58 break; 59 case dwarf::DW_LNCT_size: 60 HasLength = true; 61 break; 62 case dwarf::DW_LNCT_MD5: 63 HasMD5 = true; 64 break; 65 case dwarf::DW_LNCT_LLVM_source: 66 HasSource = true; 67 break; 68 default: 69 // We only care about values we consider optional, and new values may be 70 // added in the vendor extension range, so we do not match exhaustively. 71 break; 72 } 73 } 74 75 DWARFDebugLine::Prologue::Prologue() { clear(); } 76 77 bool DWARFDebugLine::Prologue::hasFileAtIndex(uint64_t FileIndex) const { 78 uint16_t DwarfVersion = getVersion(); 79 assert(DwarfVersion != 0 && 80 "line table prologue has no dwarf version information"); 81 if (DwarfVersion >= 5) 82 return FileIndex < FileNames.size(); 83 return FileIndex != 0 && FileIndex <= FileNames.size(); 84 } 85 86 Optional<uint64_t> DWARFDebugLine::Prologue::getLastValidFileIndex() const { 87 if (FileNames.empty()) 88 return None; 89 uint16_t DwarfVersion = getVersion(); 90 assert(DwarfVersion != 0 && 91 "line table prologue has no dwarf version information"); 92 // In DWARF v5 the file names are 0-indexed. 93 if (DwarfVersion >= 5) 94 return FileNames.size() - 1; 95 return FileNames.size(); 96 } 97 98 const llvm::DWARFDebugLine::FileNameEntry & 99 DWARFDebugLine::Prologue::getFileNameEntry(uint64_t Index) const { 100 uint16_t DwarfVersion = getVersion(); 101 assert(DwarfVersion != 0 && 102 "line table prologue has no dwarf version information"); 103 // In DWARF v5 the file names are 0-indexed. 104 if (DwarfVersion >= 5) 105 return FileNames[Index]; 106 return FileNames[Index - 1]; 107 } 108 109 void DWARFDebugLine::Prologue::clear() { 110 TotalLength = PrologueLength = 0; 111 SegSelectorSize = 0; 112 MinInstLength = MaxOpsPerInst = DefaultIsStmt = LineBase = LineRange = 0; 113 OpcodeBase = 0; 114 FormParams = dwarf::FormParams({0, 0, DWARF32}); 115 ContentTypes = ContentTypeTracker(); 116 StandardOpcodeLengths.clear(); 117 IncludeDirectories.clear(); 118 FileNames.clear(); 119 } 120 121 void DWARFDebugLine::Prologue::dump(raw_ostream &OS, 122 DIDumpOptions DumpOptions) const { 123 if (!totalLengthIsValid()) 124 return; 125 int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(FormParams.Format); 126 OS << "Line table prologue:\n" 127 << format(" total_length: 0x%0*" PRIx64 "\n", OffsetDumpWidth, 128 TotalLength) 129 << " format: " << dwarf::FormatString(FormParams.Format) << "\n" 130 << format(" version: %u\n", getVersion()); 131 if (!versionIsSupported(getVersion())) 132 return; 133 if (getVersion() >= 5) 134 OS << format(" address_size: %u\n", getAddressSize()) 135 << format(" seg_select_size: %u\n", SegSelectorSize); 136 OS << format(" prologue_length: 0x%0*" PRIx64 "\n", OffsetDumpWidth, 137 PrologueLength) 138 << format(" min_inst_length: %u\n", MinInstLength) 139 << format(getVersion() >= 4 ? "max_ops_per_inst: %u\n" : "", MaxOpsPerInst) 140 << format(" default_is_stmt: %u\n", DefaultIsStmt) 141 << format(" line_base: %i\n", LineBase) 142 << format(" line_range: %u\n", LineRange) 143 << format(" opcode_base: %u\n", OpcodeBase); 144 145 for (uint32_t I = 0; I != StandardOpcodeLengths.size(); ++I) 146 OS << formatv("standard_opcode_lengths[{0}] = {1}\n", 147 static_cast<dwarf::LineNumberOps>(I + 1), 148 StandardOpcodeLengths[I]); 149 150 if (!IncludeDirectories.empty()) { 151 // DWARF v5 starts directory indexes at 0. 152 uint32_t DirBase = getVersion() >= 5 ? 0 : 1; 153 for (uint32_t I = 0; I != IncludeDirectories.size(); ++I) { 154 OS << format("include_directories[%3u] = ", I + DirBase); 155 IncludeDirectories[I].dump(OS, DumpOptions); 156 OS << '\n'; 157 } 158 } 159 160 if (!FileNames.empty()) { 161 // DWARF v5 starts file indexes at 0. 162 uint32_t FileBase = getVersion() >= 5 ? 0 : 1; 163 for (uint32_t I = 0; I != FileNames.size(); ++I) { 164 const FileNameEntry &FileEntry = FileNames[I]; 165 OS << format("file_names[%3u]:\n", I + FileBase); 166 OS << " name: "; 167 FileEntry.Name.dump(OS, DumpOptions); 168 OS << '\n' 169 << format(" dir_index: %" PRIu64 "\n", FileEntry.DirIdx); 170 if (ContentTypes.HasMD5) 171 OS << " md5_checksum: " << FileEntry.Checksum.digest() << '\n'; 172 if (ContentTypes.HasModTime) 173 OS << format(" mod_time: 0x%8.8" PRIx64 "\n", FileEntry.ModTime); 174 if (ContentTypes.HasLength) 175 OS << format(" length: 0x%8.8" PRIx64 "\n", FileEntry.Length); 176 if (ContentTypes.HasSource) { 177 OS << " source: "; 178 FileEntry.Source.dump(OS, DumpOptions); 179 OS << '\n'; 180 } 181 } 182 } 183 } 184 185 // Parse v2-v4 directory and file tables. 186 static Error 187 parseV2DirFileTables(const DWARFDataExtractor &DebugLineData, 188 uint64_t *OffsetPtr, 189 DWARFDebugLine::ContentTypeTracker &ContentTypes, 190 std::vector<DWARFFormValue> &IncludeDirectories, 191 std::vector<DWARFDebugLine::FileNameEntry> &FileNames) { 192 while (true) { 193 Error Err = Error::success(); 194 StringRef S = DebugLineData.getCStrRef(OffsetPtr, &Err); 195 if (Err) { 196 consumeError(std::move(Err)); 197 return createStringError(errc::invalid_argument, 198 "include directories table was not null " 199 "terminated before the end of the prologue"); 200 } 201 if (S.empty()) 202 break; 203 DWARFFormValue Dir = 204 DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, S.data()); 205 IncludeDirectories.push_back(Dir); 206 } 207 208 ContentTypes.HasModTime = true; 209 ContentTypes.HasLength = true; 210 211 while (true) { 212 Error Err = Error::success(); 213 StringRef Name = DebugLineData.getCStrRef(OffsetPtr, &Err); 214 if (!Err && Name.empty()) 215 break; 216 217 DWARFDebugLine::FileNameEntry FileEntry; 218 FileEntry.Name = 219 DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name.data()); 220 FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr, &Err); 221 FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr, &Err); 222 FileEntry.Length = DebugLineData.getULEB128(OffsetPtr, &Err); 223 224 if (Err) { 225 consumeError(std::move(Err)); 226 return createStringError( 227 errc::invalid_argument, 228 "file names table was not null terminated before " 229 "the end of the prologue"); 230 } 231 FileNames.push_back(FileEntry); 232 } 233 234 return Error::success(); 235 } 236 237 // Parse v5 directory/file entry content descriptions. 238 // Returns the descriptors, or an error if we did not find a path or ran off 239 // the end of the prologue. 240 static llvm::Expected<ContentDescriptors> 241 parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, 242 DWARFDebugLine::ContentTypeTracker *ContentTypes) { 243 Error Err = Error::success(); 244 ContentDescriptors Descriptors; 245 int FormatCount = DebugLineData.getU8(OffsetPtr, &Err); 246 bool HasPath = false; 247 for (int I = 0; I != FormatCount && !Err; ++I) { 248 ContentDescriptor Descriptor; 249 Descriptor.Type = 250 dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr, &Err)); 251 Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr, &Err)); 252 if (Descriptor.Type == dwarf::DW_LNCT_path) 253 HasPath = true; 254 if (ContentTypes) 255 ContentTypes->trackContentType(Descriptor.Type); 256 Descriptors.push_back(Descriptor); 257 } 258 259 if (Err) 260 return createStringError(errc::invalid_argument, 261 "failed to parse entry content descriptors: %s", 262 toString(std::move(Err)).c_str()); 263 264 if (!HasPath) 265 return createStringError(errc::invalid_argument, 266 "failed to parse entry content descriptions" 267 " because no path was found"); 268 return Descriptors; 269 } 270 271 static Error 272 parseV5DirFileTables(const DWARFDataExtractor &DebugLineData, 273 uint64_t *OffsetPtr, const dwarf::FormParams &FormParams, 274 const DWARFContext &Ctx, const DWARFUnit *U, 275 DWARFDebugLine::ContentTypeTracker &ContentTypes, 276 std::vector<DWARFFormValue> &IncludeDirectories, 277 std::vector<DWARFDebugLine::FileNameEntry> &FileNames) { 278 // Get the directory entry description. 279 llvm::Expected<ContentDescriptors> DirDescriptors = 280 parseV5EntryFormat(DebugLineData, OffsetPtr, nullptr); 281 if (!DirDescriptors) 282 return DirDescriptors.takeError(); 283 284 // Get the directory entries, according to the format described above. 285 uint64_t DirEntryCount = DebugLineData.getULEB128(OffsetPtr); 286 for (uint64_t I = 0; I != DirEntryCount; ++I) { 287 for (auto Descriptor : *DirDescriptors) { 288 DWARFFormValue Value(Descriptor.Form); 289 switch (Descriptor.Type) { 290 case DW_LNCT_path: 291 if (!Value.extractValue(DebugLineData, OffsetPtr, FormParams, &Ctx, U)) 292 return createStringError(errc::invalid_argument, 293 "failed to parse directory entry because " 294 "extracting the form value failed"); 295 IncludeDirectories.push_back(Value); 296 break; 297 default: 298 if (!Value.skipValue(DebugLineData, OffsetPtr, FormParams)) 299 return createStringError(errc::invalid_argument, 300 "failed to parse directory entry because " 301 "skipping the form value failed"); 302 } 303 } 304 } 305 306 // Get the file entry description. 307 llvm::Expected<ContentDescriptors> FileDescriptors = 308 parseV5EntryFormat(DebugLineData, OffsetPtr, &ContentTypes); 309 if (!FileDescriptors) 310 return FileDescriptors.takeError(); 311 312 // Get the file entries, according to the format described above. 313 uint64_t FileEntryCount = DebugLineData.getULEB128(OffsetPtr); 314 for (uint64_t I = 0; I != FileEntryCount; ++I) { 315 DWARFDebugLine::FileNameEntry FileEntry; 316 for (auto Descriptor : *FileDescriptors) { 317 DWARFFormValue Value(Descriptor.Form); 318 if (!Value.extractValue(DebugLineData, OffsetPtr, FormParams, &Ctx, U)) 319 return createStringError(errc::invalid_argument, 320 "failed to parse file entry because " 321 "extracting the form value failed"); 322 switch (Descriptor.Type) { 323 case DW_LNCT_path: 324 FileEntry.Name = Value; 325 break; 326 case DW_LNCT_LLVM_source: 327 FileEntry.Source = Value; 328 break; 329 case DW_LNCT_directory_index: 330 FileEntry.DirIdx = Value.getAsUnsignedConstant().value(); 331 break; 332 case DW_LNCT_timestamp: 333 FileEntry.ModTime = Value.getAsUnsignedConstant().value(); 334 break; 335 case DW_LNCT_size: 336 FileEntry.Length = Value.getAsUnsignedConstant().value(); 337 break; 338 case DW_LNCT_MD5: 339 if (!Value.getAsBlock() || Value.getAsBlock().value().size() != 16) 340 return createStringError( 341 errc::invalid_argument, 342 "failed to parse file entry because the MD5 hash is invalid"); 343 std::uninitialized_copy_n(Value.getAsBlock().value().begin(), 16, 344 FileEntry.Checksum.begin()); 345 break; 346 default: 347 break; 348 } 349 } 350 FileNames.push_back(FileEntry); 351 } 352 return Error::success(); 353 } 354 355 uint64_t DWARFDebugLine::Prologue::getLength() const { 356 uint64_t Length = PrologueLength + sizeofTotalLength() + 357 sizeof(getVersion()) + sizeofPrologueLength(); 358 if (getVersion() >= 5) 359 Length += 2; // Address + Segment selector sizes. 360 return Length; 361 } 362 363 Error DWARFDebugLine::Prologue::parse( 364 DWARFDataExtractor DebugLineData, uint64_t *OffsetPtr, 365 function_ref<void(Error)> RecoverableErrorHandler, const DWARFContext &Ctx, 366 const DWARFUnit *U) { 367 const uint64_t PrologueOffset = *OffsetPtr; 368 369 clear(); 370 DataExtractor::Cursor Cursor(*OffsetPtr); 371 std::tie(TotalLength, FormParams.Format) = 372 DebugLineData.getInitialLength(Cursor); 373 374 DebugLineData = 375 DWARFDataExtractor(DebugLineData, Cursor.tell() + TotalLength); 376 FormParams.Version = DebugLineData.getU16(Cursor); 377 if (Cursor && !versionIsSupported(getVersion())) { 378 // Treat this error as unrecoverable - we cannot be sure what any of 379 // the data represents including the length field, so cannot skip it or make 380 // any reasonable assumptions. 381 *OffsetPtr = Cursor.tell(); 382 return createStringError( 383 errc::not_supported, 384 "parsing line table prologue at offset 0x%8.8" PRIx64 385 ": unsupported version %" PRIu16, 386 PrologueOffset, getVersion()); 387 } 388 389 if (getVersion() >= 5) { 390 FormParams.AddrSize = DebugLineData.getU8(Cursor); 391 assert((!Cursor || DebugLineData.getAddressSize() == 0 || 392 DebugLineData.getAddressSize() == getAddressSize()) && 393 "Line table header and data extractor disagree"); 394 SegSelectorSize = DebugLineData.getU8(Cursor); 395 } 396 397 PrologueLength = 398 DebugLineData.getRelocatedValue(Cursor, sizeofPrologueLength()); 399 const uint64_t EndPrologueOffset = PrologueLength + Cursor.tell(); 400 DebugLineData = DWARFDataExtractor(DebugLineData, EndPrologueOffset); 401 MinInstLength = DebugLineData.getU8(Cursor); 402 if (getVersion() >= 4) 403 MaxOpsPerInst = DebugLineData.getU8(Cursor); 404 DefaultIsStmt = DebugLineData.getU8(Cursor); 405 LineBase = DebugLineData.getU8(Cursor); 406 LineRange = DebugLineData.getU8(Cursor); 407 OpcodeBase = DebugLineData.getU8(Cursor); 408 409 if (Cursor && OpcodeBase == 0) { 410 // If the opcode base is 0, we cannot read the standard opcode lengths (of 411 // which there are supposed to be one fewer than the opcode base). Assume 412 // there are no standard opcodes and continue parsing. 413 RecoverableErrorHandler(createStringError( 414 errc::invalid_argument, 415 "parsing line table prologue at offset 0x%8.8" PRIx64 416 " found opcode base of 0. Assuming no standard opcodes", 417 PrologueOffset)); 418 } else if (Cursor) { 419 StandardOpcodeLengths.reserve(OpcodeBase - 1); 420 for (uint32_t I = 1; I < OpcodeBase; ++I) { 421 uint8_t OpLen = DebugLineData.getU8(Cursor); 422 StandardOpcodeLengths.push_back(OpLen); 423 } 424 } 425 426 *OffsetPtr = Cursor.tell(); 427 // A corrupt file name or directory table does not prevent interpretation of 428 // the main line program, so check the cursor state now so that its errors can 429 // be handled separately. 430 if (!Cursor) 431 return createStringError( 432 errc::invalid_argument, 433 "parsing line table prologue at offset 0x%8.8" PRIx64 ": %s", 434 PrologueOffset, toString(Cursor.takeError()).c_str()); 435 436 Error E = 437 getVersion() >= 5 438 ? parseV5DirFileTables(DebugLineData, OffsetPtr, FormParams, Ctx, U, 439 ContentTypes, IncludeDirectories, FileNames) 440 : parseV2DirFileTables(DebugLineData, OffsetPtr, ContentTypes, 441 IncludeDirectories, FileNames); 442 if (E) { 443 RecoverableErrorHandler(joinErrors( 444 createStringError( 445 errc::invalid_argument, 446 "parsing line table prologue at 0x%8.8" PRIx64 447 " found an invalid directory or file table description at" 448 " 0x%8.8" PRIx64, 449 PrologueOffset, *OffsetPtr), 450 std::move(E))); 451 return Error::success(); 452 } 453 454 assert(*OffsetPtr <= EndPrologueOffset); 455 if (*OffsetPtr != EndPrologueOffset) { 456 RecoverableErrorHandler(createStringError( 457 errc::invalid_argument, 458 "unknown data in line table prologue at offset 0x%8.8" PRIx64 459 ": parsing ended (at offset 0x%8.8" PRIx64 460 ") before reaching the prologue end at offset 0x%8.8" PRIx64, 461 PrologueOffset, *OffsetPtr, EndPrologueOffset)); 462 } 463 return Error::success(); 464 } 465 466 DWARFDebugLine::Row::Row(bool DefaultIsStmt) { reset(DefaultIsStmt); } 467 468 void DWARFDebugLine::Row::postAppend() { 469 Discriminator = 0; 470 BasicBlock = false; 471 PrologueEnd = false; 472 EpilogueBegin = false; 473 } 474 475 void DWARFDebugLine::Row::reset(bool DefaultIsStmt) { 476 Address.Address = 0; 477 Address.SectionIndex = object::SectionedAddress::UndefSection; 478 Line = 1; 479 Column = 0; 480 File = 1; 481 Isa = 0; 482 Discriminator = 0; 483 IsStmt = DefaultIsStmt; 484 BasicBlock = false; 485 EndSequence = false; 486 PrologueEnd = false; 487 EpilogueBegin = false; 488 } 489 490 void DWARFDebugLine::Row::dumpTableHeader(raw_ostream &OS, unsigned Indent) { 491 OS.indent(Indent) 492 << "Address Line Column File ISA Discriminator Flags\n"; 493 OS.indent(Indent) 494 << "------------------ ------ ------ ------ --- ------------- " 495 "-------------\n"; 496 } 497 498 void DWARFDebugLine::Row::dump(raw_ostream &OS) const { 499 OS << format("0x%16.16" PRIx64 " %6u %6u", Address.Address, Line, Column) 500 << format(" %6u %3u %13u ", File, Isa, Discriminator) 501 << (IsStmt ? " is_stmt" : "") << (BasicBlock ? " basic_block" : "") 502 << (PrologueEnd ? " prologue_end" : "") 503 << (EpilogueBegin ? " epilogue_begin" : "") 504 << (EndSequence ? " end_sequence" : "") << '\n'; 505 } 506 507 DWARFDebugLine::Sequence::Sequence() { reset(); } 508 509 void DWARFDebugLine::Sequence::reset() { 510 LowPC = 0; 511 HighPC = 0; 512 SectionIndex = object::SectionedAddress::UndefSection; 513 FirstRowIndex = 0; 514 LastRowIndex = 0; 515 Empty = true; 516 } 517 518 DWARFDebugLine::LineTable::LineTable() { clear(); } 519 520 void DWARFDebugLine::LineTable::dump(raw_ostream &OS, 521 DIDumpOptions DumpOptions) const { 522 Prologue.dump(OS, DumpOptions); 523 524 if (!Rows.empty()) { 525 OS << '\n'; 526 Row::dumpTableHeader(OS, 0); 527 for (const Row &R : Rows) { 528 R.dump(OS); 529 } 530 } 531 532 // Terminate the table with a final blank line to clearly delineate it from 533 // later dumps. 534 OS << '\n'; 535 } 536 537 void DWARFDebugLine::LineTable::clear() { 538 Prologue.clear(); 539 Rows.clear(); 540 Sequences.clear(); 541 } 542 543 DWARFDebugLine::ParsingState::ParsingState( 544 struct LineTable *LT, uint64_t TableOffset, 545 function_ref<void(Error)> ErrorHandler) 546 : LineTable(LT), LineTableOffset(TableOffset), ErrorHandler(ErrorHandler) { 547 resetRowAndSequence(); 548 } 549 550 void DWARFDebugLine::ParsingState::resetRowAndSequence() { 551 Row.reset(LineTable->Prologue.DefaultIsStmt); 552 Sequence.reset(); 553 } 554 555 void DWARFDebugLine::ParsingState::appendRowToMatrix() { 556 unsigned RowNumber = LineTable->Rows.size(); 557 if (Sequence.Empty) { 558 // Record the beginning of instruction sequence. 559 Sequence.Empty = false; 560 Sequence.LowPC = Row.Address.Address; 561 Sequence.FirstRowIndex = RowNumber; 562 } 563 LineTable->appendRow(Row); 564 if (Row.EndSequence) { 565 // Record the end of instruction sequence. 566 Sequence.HighPC = Row.Address.Address; 567 Sequence.LastRowIndex = RowNumber + 1; 568 Sequence.SectionIndex = Row.Address.SectionIndex; 569 if (Sequence.isValid()) 570 LineTable->appendSequence(Sequence); 571 Sequence.reset(); 572 } 573 Row.postAppend(); 574 } 575 576 const DWARFDebugLine::LineTable * 577 DWARFDebugLine::getLineTable(uint64_t Offset) const { 578 LineTableConstIter Pos = LineTableMap.find(Offset); 579 if (Pos != LineTableMap.end()) 580 return &Pos->second; 581 return nullptr; 582 } 583 584 Expected<const DWARFDebugLine::LineTable *> DWARFDebugLine::getOrParseLineTable( 585 DWARFDataExtractor &DebugLineData, uint64_t Offset, const DWARFContext &Ctx, 586 const DWARFUnit *U, function_ref<void(Error)> RecoverableErrorHandler) { 587 if (!DebugLineData.isValidOffset(Offset)) 588 return createStringError(errc::invalid_argument, "offset 0x%8.8" PRIx64 589 " is not a valid debug line section offset", 590 Offset); 591 592 std::pair<LineTableIter, bool> Pos = 593 LineTableMap.insert(LineTableMapTy::value_type(Offset, LineTable())); 594 LineTable *LT = &Pos.first->second; 595 if (Pos.second) { 596 if (Error Err = 597 LT->parse(DebugLineData, &Offset, Ctx, U, RecoverableErrorHandler)) 598 return std::move(Err); 599 return LT; 600 } 601 return LT; 602 } 603 604 void DWARFDebugLine::clearLineTable(uint64_t Offset) { 605 LineTableMap.erase(Offset); 606 } 607 608 static StringRef getOpcodeName(uint8_t Opcode, uint8_t OpcodeBase) { 609 assert(Opcode != 0); 610 if (Opcode < OpcodeBase) 611 return LNStandardString(Opcode); 612 return "special"; 613 } 614 615 uint64_t DWARFDebugLine::ParsingState::advanceAddr(uint64_t OperationAdvance, 616 uint8_t Opcode, 617 uint64_t OpcodeOffset) { 618 StringRef OpcodeName = getOpcodeName(Opcode, LineTable->Prologue.OpcodeBase); 619 // For versions less than 4, the MaxOpsPerInst member is set to 0, as the 620 // maximum_operations_per_instruction field wasn't introduced until DWARFv4. 621 // Don't warn about bad values in this situation. 622 if (ReportAdvanceAddrProblem && LineTable->Prologue.getVersion() >= 4 && 623 LineTable->Prologue.MaxOpsPerInst != 1) 624 ErrorHandler(createStringError( 625 errc::not_supported, 626 "line table program at offset 0x%8.8" PRIx64 627 " contains a %s opcode at offset 0x%8.8" PRIx64 628 ", but the prologue maximum_operations_per_instruction value is %" PRId8 629 ", which is unsupported. Assuming a value of 1 instead", 630 LineTableOffset, OpcodeName.data(), OpcodeOffset, 631 LineTable->Prologue.MaxOpsPerInst)); 632 if (ReportAdvanceAddrProblem && LineTable->Prologue.MinInstLength == 0) 633 ErrorHandler( 634 createStringError(errc::invalid_argument, 635 "line table program at offset 0x%8.8" PRIx64 636 " contains a %s opcode at offset 0x%8.8" PRIx64 637 ", but the prologue minimum_instruction_length value " 638 "is 0, which prevents any address advancing", 639 LineTableOffset, OpcodeName.data(), OpcodeOffset)); 640 ReportAdvanceAddrProblem = false; 641 uint64_t AddrOffset = OperationAdvance * LineTable->Prologue.MinInstLength; 642 Row.Address.Address += AddrOffset; 643 return AddrOffset; 644 } 645 646 DWARFDebugLine::ParsingState::AddrAndAdjustedOpcode 647 DWARFDebugLine::ParsingState::advanceAddrForOpcode(uint8_t Opcode, 648 uint64_t OpcodeOffset) { 649 assert(Opcode == DW_LNS_const_add_pc || 650 Opcode >= LineTable->Prologue.OpcodeBase); 651 if (ReportBadLineRange && LineTable->Prologue.LineRange == 0) { 652 StringRef OpcodeName = 653 getOpcodeName(Opcode, LineTable->Prologue.OpcodeBase); 654 ErrorHandler( 655 createStringError(errc::not_supported, 656 "line table program at offset 0x%8.8" PRIx64 657 " contains a %s opcode at offset 0x%8.8" PRIx64 658 ", but the prologue line_range value is 0. The " 659 "address and line will not be adjusted", 660 LineTableOffset, OpcodeName.data(), OpcodeOffset)); 661 ReportBadLineRange = false; 662 } 663 664 uint8_t OpcodeValue = Opcode; 665 if (Opcode == DW_LNS_const_add_pc) 666 OpcodeValue = 255; 667 uint8_t AdjustedOpcode = OpcodeValue - LineTable->Prologue.OpcodeBase; 668 uint64_t OperationAdvance = 669 LineTable->Prologue.LineRange != 0 670 ? AdjustedOpcode / LineTable->Prologue.LineRange 671 : 0; 672 uint64_t AddrOffset = advanceAddr(OperationAdvance, Opcode, OpcodeOffset); 673 return {AddrOffset, AdjustedOpcode}; 674 } 675 676 DWARFDebugLine::ParsingState::AddrAndLineDelta 677 DWARFDebugLine::ParsingState::handleSpecialOpcode(uint8_t Opcode, 678 uint64_t OpcodeOffset) { 679 // A special opcode value is chosen based on the amount that needs 680 // to be added to the line and address registers. The maximum line 681 // increment for a special opcode is the value of the line_base 682 // field in the header, plus the value of the line_range field, 683 // minus 1 (line base + line range - 1). If the desired line 684 // increment is greater than the maximum line increment, a standard 685 // opcode must be used instead of a special opcode. The "address 686 // advance" is calculated by dividing the desired address increment 687 // by the minimum_instruction_length field from the header. The 688 // special opcode is then calculated using the following formula: 689 // 690 // opcode = (desired line increment - line_base) + 691 // (line_range * address advance) + opcode_base 692 // 693 // If the resulting opcode is greater than 255, a standard opcode 694 // must be used instead. 695 // 696 // To decode a special opcode, subtract the opcode_base from the 697 // opcode itself to give the adjusted opcode. The amount to 698 // increment the address register is the result of the adjusted 699 // opcode divided by the line_range multiplied by the 700 // minimum_instruction_length field from the header. That is: 701 // 702 // address increment = (adjusted opcode / line_range) * 703 // minimum_instruction_length 704 // 705 // The amount to increment the line register is the line_base plus 706 // the result of the adjusted opcode modulo the line_range. That is: 707 // 708 // line increment = line_base + (adjusted opcode % line_range) 709 710 DWARFDebugLine::ParsingState::AddrAndAdjustedOpcode AddrAdvanceResult = 711 advanceAddrForOpcode(Opcode, OpcodeOffset); 712 int32_t LineOffset = 0; 713 if (LineTable->Prologue.LineRange != 0) 714 LineOffset = 715 LineTable->Prologue.LineBase + 716 (AddrAdvanceResult.AdjustedOpcode % LineTable->Prologue.LineRange); 717 Row.Line += LineOffset; 718 return {AddrAdvanceResult.AddrDelta, LineOffset}; 719 } 720 721 /// Parse a ULEB128 using the specified \p Cursor. \returns the parsed value on 722 /// success, or None if \p Cursor is in a failing state. 723 template <typename T> 724 static Optional<T> parseULEB128(DWARFDataExtractor &Data, 725 DataExtractor::Cursor &Cursor) { 726 T Value = Data.getULEB128(Cursor); 727 if (Cursor) 728 return Value; 729 return None; 730 } 731 732 Error DWARFDebugLine::LineTable::parse( 733 DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, 734 const DWARFContext &Ctx, const DWARFUnit *U, 735 function_ref<void(Error)> RecoverableErrorHandler, raw_ostream *OS, 736 bool Verbose) { 737 assert((OS || !Verbose) && "cannot have verbose output without stream"); 738 const uint64_t DebugLineOffset = *OffsetPtr; 739 740 clear(); 741 742 Error PrologueErr = 743 Prologue.parse(DebugLineData, OffsetPtr, RecoverableErrorHandler, Ctx, U); 744 745 if (OS) { 746 DIDumpOptions DumpOptions; 747 DumpOptions.Verbose = Verbose; 748 Prologue.dump(*OS, DumpOptions); 749 } 750 751 if (PrologueErr) { 752 // Ensure there is a blank line after the prologue to clearly delineate it 753 // from later dumps. 754 if (OS) 755 *OS << "\n"; 756 return PrologueErr; 757 } 758 759 uint64_t ProgramLength = Prologue.TotalLength + Prologue.sizeofTotalLength(); 760 if (!DebugLineData.isValidOffsetForDataOfSize(DebugLineOffset, 761 ProgramLength)) { 762 assert(DebugLineData.size() > DebugLineOffset && 763 "prologue parsing should handle invalid offset"); 764 uint64_t BytesRemaining = DebugLineData.size() - DebugLineOffset; 765 RecoverableErrorHandler( 766 createStringError(errc::invalid_argument, 767 "line table program with offset 0x%8.8" PRIx64 768 " has length 0x%8.8" PRIx64 " but only 0x%8.8" PRIx64 769 " bytes are available", 770 DebugLineOffset, ProgramLength, BytesRemaining)); 771 // Continue by capping the length at the number of remaining bytes. 772 ProgramLength = BytesRemaining; 773 } 774 775 // Create a DataExtractor which can only see the data up to the end of the 776 // table, to prevent reading past the end. 777 const uint64_t EndOffset = DebugLineOffset + ProgramLength; 778 DWARFDataExtractor TableData(DebugLineData, EndOffset); 779 780 // See if we should tell the data extractor the address size. 781 if (TableData.getAddressSize() == 0) 782 TableData.setAddressSize(Prologue.getAddressSize()); 783 else 784 assert(Prologue.getAddressSize() == 0 || 785 Prologue.getAddressSize() == TableData.getAddressSize()); 786 787 ParsingState State(this, DebugLineOffset, RecoverableErrorHandler); 788 789 *OffsetPtr = DebugLineOffset + Prologue.getLength(); 790 if (OS && *OffsetPtr < EndOffset) { 791 *OS << '\n'; 792 Row::dumpTableHeader(*OS, /*Indent=*/Verbose ? 12 : 0); 793 } 794 bool TombstonedAddress = false; 795 auto EmitRow = [&] { 796 if (!TombstonedAddress) { 797 if (Verbose) { 798 *OS << "\n"; 799 OS->indent(12); 800 } 801 if (OS) 802 State.Row.dump(*OS); 803 State.appendRowToMatrix(); 804 } 805 }; 806 while (*OffsetPtr < EndOffset) { 807 DataExtractor::Cursor Cursor(*OffsetPtr); 808 809 if (Verbose) 810 *OS << format("0x%08.08" PRIx64 ": ", *OffsetPtr); 811 812 uint64_t OpcodeOffset = *OffsetPtr; 813 uint8_t Opcode = TableData.getU8(Cursor); 814 size_t RowCount = Rows.size(); 815 816 if (Cursor && Verbose) 817 *OS << format("%02.02" PRIx8 " ", Opcode); 818 819 if (Opcode == 0) { 820 // Extended Opcodes always start with a zero opcode followed by 821 // a uleb128 length so you can skip ones you don't know about 822 uint64_t Len = TableData.getULEB128(Cursor); 823 uint64_t ExtOffset = Cursor.tell(); 824 825 // Tolerate zero-length; assume length is correct and soldier on. 826 if (Len == 0) { 827 if (Cursor && Verbose) 828 *OS << "Badly formed extended line op (length 0)\n"; 829 if (!Cursor) { 830 if (Verbose) 831 *OS << "\n"; 832 RecoverableErrorHandler(Cursor.takeError()); 833 } 834 *OffsetPtr = Cursor.tell(); 835 continue; 836 } 837 838 uint8_t SubOpcode = TableData.getU8(Cursor); 839 // OperandOffset will be the same as ExtOffset, if it was not possible to 840 // read the SubOpcode. 841 uint64_t OperandOffset = Cursor.tell(); 842 if (Verbose) 843 *OS << LNExtendedString(SubOpcode); 844 switch (SubOpcode) { 845 case DW_LNE_end_sequence: 846 // Set the end_sequence register of the state machine to true and 847 // append a row to the matrix using the current values of the 848 // state-machine registers. Then reset the registers to the initial 849 // values specified above. Every statement program sequence must end 850 // with a DW_LNE_end_sequence instruction which creates a row whose 851 // address is that of the byte after the last target machine instruction 852 // of the sequence. 853 State.Row.EndSequence = true; 854 // No need to test the Cursor is valid here, since it must be to get 855 // into this code path - if it were invalid, the default case would be 856 // followed. 857 EmitRow(); 858 State.resetRowAndSequence(); 859 break; 860 861 case DW_LNE_set_address: 862 // Takes a single relocatable address as an operand. The size of the 863 // operand is the size appropriate to hold an address on the target 864 // machine. Set the address register to the value given by the 865 // relocatable address. All of the other statement program opcodes 866 // that affect the address register add a delta to it. This instruction 867 // stores a relocatable value into it instead. 868 // 869 // Make sure the extractor knows the address size. If not, infer it 870 // from the size of the operand. 871 { 872 uint8_t ExtractorAddressSize = TableData.getAddressSize(); 873 uint64_t OpcodeAddressSize = Len - 1; 874 if (ExtractorAddressSize != OpcodeAddressSize && 875 ExtractorAddressSize != 0) 876 RecoverableErrorHandler(createStringError( 877 errc::invalid_argument, 878 "mismatching address size at offset 0x%8.8" PRIx64 879 " expected 0x%2.2" PRIx8 " found 0x%2.2" PRIx64, 880 ExtOffset, ExtractorAddressSize, Len - 1)); 881 882 // Assume that the line table is correct and temporarily override the 883 // address size. If the size is unsupported, give up trying to read 884 // the address and continue to the next opcode. 885 if (OpcodeAddressSize != 1 && OpcodeAddressSize != 2 && 886 OpcodeAddressSize != 4 && OpcodeAddressSize != 8) { 887 RecoverableErrorHandler(createStringError( 888 errc::invalid_argument, 889 "address size 0x%2.2" PRIx64 890 " of DW_LNE_set_address opcode at offset 0x%8.8" PRIx64 891 " is unsupported", 892 OpcodeAddressSize, ExtOffset)); 893 TableData.skip(Cursor, OpcodeAddressSize); 894 } else { 895 TableData.setAddressSize(OpcodeAddressSize); 896 State.Row.Address.Address = TableData.getRelocatedAddress( 897 Cursor, &State.Row.Address.SectionIndex); 898 899 uint64_t Tombstone = 900 dwarf::computeTombstoneAddress(OpcodeAddressSize); 901 TombstonedAddress = State.Row.Address.Address == Tombstone; 902 903 // Restore the address size if the extractor already had it. 904 if (ExtractorAddressSize != 0) 905 TableData.setAddressSize(ExtractorAddressSize); 906 } 907 908 if (Cursor && Verbose) { 909 *OS << " ("; 910 DWARFFormValue::dumpAddress(*OS, OpcodeAddressSize, State.Row.Address.Address); 911 *OS << ')'; 912 } 913 } 914 break; 915 916 case DW_LNE_define_file: 917 // Takes 4 arguments. The first is a null terminated string containing 918 // a source file name. The second is an unsigned LEB128 number 919 // representing the directory index of the directory in which the file 920 // was found. The third is an unsigned LEB128 number representing the 921 // time of last modification of the file. The fourth is an unsigned 922 // LEB128 number representing the length in bytes of the file. The time 923 // and length fields may contain LEB128(0) if the information is not 924 // available. 925 // 926 // The directory index represents an entry in the include_directories 927 // section of the statement program prologue. The index is LEB128(0) 928 // if the file was found in the current directory of the compilation, 929 // LEB128(1) if it was found in the first directory in the 930 // include_directories section, and so on. The directory index is 931 // ignored for file names that represent full path names. 932 // 933 // The files are numbered, starting at 1, in the order in which they 934 // appear; the names in the prologue come before names defined by 935 // the DW_LNE_define_file instruction. These numbers are used in the 936 // the file register of the state machine. 937 { 938 FileNameEntry FileEntry; 939 const char *Name = TableData.getCStr(Cursor); 940 FileEntry.Name = 941 DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name); 942 FileEntry.DirIdx = TableData.getULEB128(Cursor); 943 FileEntry.ModTime = TableData.getULEB128(Cursor); 944 FileEntry.Length = TableData.getULEB128(Cursor); 945 Prologue.FileNames.push_back(FileEntry); 946 if (Cursor && Verbose) 947 *OS << " (" << Name << ", dir=" << FileEntry.DirIdx << ", mod_time=" 948 << format("(0x%16.16" PRIx64 ")", FileEntry.ModTime) 949 << ", length=" << FileEntry.Length << ")"; 950 } 951 break; 952 953 case DW_LNE_set_discriminator: 954 State.Row.Discriminator = TableData.getULEB128(Cursor); 955 if (Cursor && Verbose) 956 *OS << " (" << State.Row.Discriminator << ")"; 957 break; 958 959 default: 960 if (Cursor && Verbose) 961 *OS << format("Unrecognized extended op 0x%02.02" PRIx8, SubOpcode) 962 << format(" length %" PRIx64, Len); 963 // Len doesn't include the zero opcode byte or the length itself, but 964 // it does include the sub_opcode, so we have to adjust for that. 965 TableData.skip(Cursor, Len - 1); 966 break; 967 } 968 // Make sure the length as recorded in the table and the standard length 969 // for the opcode match. If they don't, continue from the end as claimed 970 // by the table. Similarly, continue from the claimed end in the event of 971 // a parsing error. 972 uint64_t End = ExtOffset + Len; 973 if (Cursor && Cursor.tell() != End) 974 RecoverableErrorHandler(createStringError( 975 errc::illegal_byte_sequence, 976 "unexpected line op length at offset 0x%8.8" PRIx64 977 " expected 0x%2.2" PRIx64 " found 0x%2.2" PRIx64, 978 ExtOffset, Len, Cursor.tell() - ExtOffset)); 979 if (!Cursor && Verbose) { 980 DWARFDataExtractor::Cursor ByteCursor(OperandOffset); 981 uint8_t Byte = TableData.getU8(ByteCursor); 982 if (ByteCursor) { 983 *OS << " (<parsing error>"; 984 do { 985 *OS << format(" %2.2" PRIx8, Byte); 986 Byte = TableData.getU8(ByteCursor); 987 } while (ByteCursor); 988 *OS << ")"; 989 } 990 991 // The only parse failure in this case should be if the end was reached. 992 // In that case, throw away the error, as the main Cursor's error will 993 // be sufficient. 994 consumeError(ByteCursor.takeError()); 995 } 996 *OffsetPtr = End; 997 } else if (Opcode < Prologue.OpcodeBase) { 998 if (Verbose) 999 *OS << LNStandardString(Opcode); 1000 switch (Opcode) { 1001 // Standard Opcodes 1002 case DW_LNS_copy: 1003 // Takes no arguments. Append a row to the matrix using the 1004 // current values of the state-machine registers. 1005 EmitRow(); 1006 break; 1007 1008 case DW_LNS_advance_pc: 1009 // Takes a single unsigned LEB128 operand, multiplies it by the 1010 // min_inst_length field of the prologue, and adds the 1011 // result to the address register of the state machine. 1012 if (Optional<uint64_t> Operand = 1013 parseULEB128<uint64_t>(TableData, Cursor)) { 1014 uint64_t AddrOffset = 1015 State.advanceAddr(*Operand, Opcode, OpcodeOffset); 1016 if (Verbose) 1017 *OS << " (" << AddrOffset << ")"; 1018 } 1019 break; 1020 1021 case DW_LNS_advance_line: 1022 // Takes a single signed LEB128 operand and adds that value to 1023 // the line register of the state machine. 1024 { 1025 int64_t LineDelta = TableData.getSLEB128(Cursor); 1026 if (Cursor) { 1027 State.Row.Line += LineDelta; 1028 if (Verbose) 1029 *OS << " (" << State.Row.Line << ")"; 1030 } 1031 } 1032 break; 1033 1034 case DW_LNS_set_file: 1035 // Takes a single unsigned LEB128 operand and stores it in the file 1036 // register of the state machine. 1037 if (Optional<uint16_t> File = 1038 parseULEB128<uint16_t>(TableData, Cursor)) { 1039 State.Row.File = *File; 1040 if (Verbose) 1041 *OS << " (" << State.Row.File << ")"; 1042 } 1043 break; 1044 1045 case DW_LNS_set_column: 1046 // Takes a single unsigned LEB128 operand and stores it in the 1047 // column register of the state machine. 1048 if (Optional<uint16_t> Column = 1049 parseULEB128<uint16_t>(TableData, Cursor)) { 1050 State.Row.Column = *Column; 1051 if (Verbose) 1052 *OS << " (" << State.Row.Column << ")"; 1053 } 1054 break; 1055 1056 case DW_LNS_negate_stmt: 1057 // Takes no arguments. Set the is_stmt register of the state 1058 // machine to the logical negation of its current value. 1059 State.Row.IsStmt = !State.Row.IsStmt; 1060 break; 1061 1062 case DW_LNS_set_basic_block: 1063 // Takes no arguments. Set the basic_block register of the 1064 // state machine to true 1065 State.Row.BasicBlock = true; 1066 break; 1067 1068 case DW_LNS_const_add_pc: 1069 // Takes no arguments. Add to the address register of the state 1070 // machine the address increment value corresponding to special 1071 // opcode 255. The motivation for DW_LNS_const_add_pc is this: 1072 // when the statement program needs to advance the address by a 1073 // small amount, it can use a single special opcode, which occupies 1074 // a single byte. When it needs to advance the address by up to 1075 // twice the range of the last special opcode, it can use 1076 // DW_LNS_const_add_pc followed by a special opcode, for a total 1077 // of two bytes. Only if it needs to advance the address by more 1078 // than twice that range will it need to use both DW_LNS_advance_pc 1079 // and a special opcode, requiring three or more bytes. 1080 { 1081 uint64_t AddrOffset = 1082 State.advanceAddrForOpcode(Opcode, OpcodeOffset).AddrDelta; 1083 if (Verbose) 1084 *OS << format(" (0x%16.16" PRIx64 ")", AddrOffset); 1085 } 1086 break; 1087 1088 case DW_LNS_fixed_advance_pc: 1089 // Takes a single uhalf operand. Add to the address register of 1090 // the state machine the value of the (unencoded) operand. This 1091 // is the only extended opcode that takes an argument that is not 1092 // a variable length number. The motivation for DW_LNS_fixed_advance_pc 1093 // is this: existing assemblers cannot emit DW_LNS_advance_pc or 1094 // special opcodes because they cannot encode LEB128 numbers or 1095 // judge when the computation of a special opcode overflows and 1096 // requires the use of DW_LNS_advance_pc. Such assemblers, however, 1097 // can use DW_LNS_fixed_advance_pc instead, sacrificing compression. 1098 { 1099 uint16_t PCOffset = 1100 TableData.getRelocatedValue(Cursor, 2); 1101 if (Cursor) { 1102 State.Row.Address.Address += PCOffset; 1103 if (Verbose) 1104 *OS << format(" (0x%4.4" PRIx16 ")", PCOffset); 1105 } 1106 } 1107 break; 1108 1109 case DW_LNS_set_prologue_end: 1110 // Takes no arguments. Set the prologue_end register of the 1111 // state machine to true 1112 State.Row.PrologueEnd = true; 1113 break; 1114 1115 case DW_LNS_set_epilogue_begin: 1116 // Takes no arguments. Set the basic_block register of the 1117 // state machine to true 1118 State.Row.EpilogueBegin = true; 1119 break; 1120 1121 case DW_LNS_set_isa: 1122 // Takes a single unsigned LEB128 operand and stores it in the 1123 // ISA register of the state machine. 1124 if (Optional<uint8_t> Isa = parseULEB128<uint8_t>(TableData, Cursor)) { 1125 State.Row.Isa = *Isa; 1126 if (Verbose) 1127 *OS << " (" << (uint64_t)State.Row.Isa << ")"; 1128 } 1129 break; 1130 1131 default: 1132 // Handle any unknown standard opcodes here. We know the lengths 1133 // of such opcodes because they are specified in the prologue 1134 // as a multiple of LEB128 operands for each opcode. 1135 { 1136 assert(Opcode - 1U < Prologue.StandardOpcodeLengths.size()); 1137 if (Verbose) 1138 *OS << "Unrecognized standard opcode"; 1139 uint8_t OpcodeLength = Prologue.StandardOpcodeLengths[Opcode - 1]; 1140 std::vector<uint64_t> Operands; 1141 for (uint8_t I = 0; I < OpcodeLength; ++I) { 1142 if (Optional<uint64_t> Value = 1143 parseULEB128<uint64_t>(TableData, Cursor)) 1144 Operands.push_back(*Value); 1145 else 1146 break; 1147 } 1148 if (Verbose && !Operands.empty()) { 1149 *OS << " (operands: "; 1150 bool First = true; 1151 for (uint64_t Value : Operands) { 1152 if (!First) 1153 *OS << ", "; 1154 First = false; 1155 *OS << format("0x%16.16" PRIx64, Value); 1156 } 1157 if (Verbose) 1158 *OS << ')'; 1159 } 1160 } 1161 break; 1162 } 1163 1164 *OffsetPtr = Cursor.tell(); 1165 } else { 1166 // Special Opcodes. 1167 ParsingState::AddrAndLineDelta Delta = 1168 State.handleSpecialOpcode(Opcode, OpcodeOffset); 1169 1170 if (Verbose) 1171 *OS << "address += " << Delta.Address << ", line += " << Delta.Line; 1172 EmitRow(); 1173 *OffsetPtr = Cursor.tell(); 1174 } 1175 1176 // When a row is added to the matrix, it is also dumped, which includes a 1177 // new line already, so don't add an extra one. 1178 if (Verbose && Rows.size() == RowCount) 1179 *OS << "\n"; 1180 1181 // Most parse failures other than when parsing extended opcodes are due to 1182 // failures to read ULEBs. Bail out of parsing, since we don't know where to 1183 // continue reading from as there is no stated length for such byte 1184 // sequences. Print the final trailing new line if needed before doing so. 1185 if (!Cursor && Opcode != 0) { 1186 if (Verbose) 1187 *OS << "\n"; 1188 return Cursor.takeError(); 1189 } 1190 1191 if (!Cursor) 1192 RecoverableErrorHandler(Cursor.takeError()); 1193 } 1194 1195 if (!State.Sequence.Empty) 1196 RecoverableErrorHandler(createStringError( 1197 errc::illegal_byte_sequence, 1198 "last sequence in debug line table at offset 0x%8.8" PRIx64 1199 " is not terminated", 1200 DebugLineOffset)); 1201 1202 // Sort all sequences so that address lookup will work faster. 1203 if (!Sequences.empty()) { 1204 llvm::sort(Sequences, Sequence::orderByHighPC); 1205 // Note: actually, instruction address ranges of sequences should not 1206 // overlap (in shared objects and executables). If they do, the address 1207 // lookup would still work, though, but result would be ambiguous. 1208 // We don't report warning in this case. For example, 1209 // sometimes .so compiled from multiple object files contains a few 1210 // rudimentary sequences for address ranges [0x0, 0xsomething). 1211 } 1212 1213 // Terminate the table with a final blank line to clearly delineate it from 1214 // later dumps. 1215 if (OS) 1216 *OS << "\n"; 1217 1218 return Error::success(); 1219 } 1220 1221 uint32_t DWARFDebugLine::LineTable::findRowInSeq( 1222 const DWARFDebugLine::Sequence &Seq, 1223 object::SectionedAddress Address) const { 1224 if (!Seq.containsPC(Address)) 1225 return UnknownRowIndex; 1226 assert(Seq.SectionIndex == Address.SectionIndex); 1227 // In some cases, e.g. first instruction in a function, the compiler generates 1228 // two entries, both with the same address. We want the last one. 1229 // 1230 // In general we want a non-empty range: the last row whose address is less 1231 // than or equal to Address. This can be computed as upper_bound - 1. 1232 DWARFDebugLine::Row Row; 1233 Row.Address = Address; 1234 RowIter FirstRow = Rows.begin() + Seq.FirstRowIndex; 1235 RowIter LastRow = Rows.begin() + Seq.LastRowIndex; 1236 assert(FirstRow->Address.Address <= Row.Address.Address && 1237 Row.Address.Address < LastRow[-1].Address.Address); 1238 RowIter RowPos = std::upper_bound(FirstRow + 1, LastRow - 1, Row, 1239 DWARFDebugLine::Row::orderByAddress) - 1240 1; 1241 assert(Seq.SectionIndex == RowPos->Address.SectionIndex); 1242 return RowPos - Rows.begin(); 1243 } 1244 1245 uint32_t DWARFDebugLine::LineTable::lookupAddress( 1246 object::SectionedAddress Address) const { 1247 1248 // Search for relocatable addresses 1249 uint32_t Result = lookupAddressImpl(Address); 1250 1251 if (Result != UnknownRowIndex || 1252 Address.SectionIndex == object::SectionedAddress::UndefSection) 1253 return Result; 1254 1255 // Search for absolute addresses 1256 Address.SectionIndex = object::SectionedAddress::UndefSection; 1257 return lookupAddressImpl(Address); 1258 } 1259 1260 uint32_t DWARFDebugLine::LineTable::lookupAddressImpl( 1261 object::SectionedAddress Address) const { 1262 // First, find an instruction sequence containing the given address. 1263 DWARFDebugLine::Sequence Sequence; 1264 Sequence.SectionIndex = Address.SectionIndex; 1265 Sequence.HighPC = Address.Address; 1266 SequenceIter It = llvm::upper_bound(Sequences, Sequence, 1267 DWARFDebugLine::Sequence::orderByHighPC); 1268 if (It == Sequences.end() || It->SectionIndex != Address.SectionIndex) 1269 return UnknownRowIndex; 1270 return findRowInSeq(*It, Address); 1271 } 1272 1273 bool DWARFDebugLine::LineTable::lookupAddressRange( 1274 object::SectionedAddress Address, uint64_t Size, 1275 std::vector<uint32_t> &Result) const { 1276 1277 // Search for relocatable addresses 1278 if (lookupAddressRangeImpl(Address, Size, Result)) 1279 return true; 1280 1281 if (Address.SectionIndex == object::SectionedAddress::UndefSection) 1282 return false; 1283 1284 // Search for absolute addresses 1285 Address.SectionIndex = object::SectionedAddress::UndefSection; 1286 return lookupAddressRangeImpl(Address, Size, Result); 1287 } 1288 1289 bool DWARFDebugLine::LineTable::lookupAddressRangeImpl( 1290 object::SectionedAddress Address, uint64_t Size, 1291 std::vector<uint32_t> &Result) const { 1292 if (Sequences.empty()) 1293 return false; 1294 uint64_t EndAddr = Address.Address + Size; 1295 // First, find an instruction sequence containing the given address. 1296 DWARFDebugLine::Sequence Sequence; 1297 Sequence.SectionIndex = Address.SectionIndex; 1298 Sequence.HighPC = Address.Address; 1299 SequenceIter LastSeq = Sequences.end(); 1300 SequenceIter SeqPos = llvm::upper_bound( 1301 Sequences, Sequence, DWARFDebugLine::Sequence::orderByHighPC); 1302 if (SeqPos == LastSeq || !SeqPos->containsPC(Address)) 1303 return false; 1304 1305 SequenceIter StartPos = SeqPos; 1306 1307 // Add the rows from the first sequence to the vector, starting with the 1308 // index we just calculated 1309 1310 while (SeqPos != LastSeq && SeqPos->LowPC < EndAddr) { 1311 const DWARFDebugLine::Sequence &CurSeq = *SeqPos; 1312 // For the first sequence, we need to find which row in the sequence is the 1313 // first in our range. 1314 uint32_t FirstRowIndex = CurSeq.FirstRowIndex; 1315 if (SeqPos == StartPos) 1316 FirstRowIndex = findRowInSeq(CurSeq, Address); 1317 1318 // Figure out the last row in the range. 1319 uint32_t LastRowIndex = 1320 findRowInSeq(CurSeq, {EndAddr - 1, Address.SectionIndex}); 1321 if (LastRowIndex == UnknownRowIndex) 1322 LastRowIndex = CurSeq.LastRowIndex - 1; 1323 1324 assert(FirstRowIndex != UnknownRowIndex); 1325 assert(LastRowIndex != UnknownRowIndex); 1326 1327 for (uint32_t I = FirstRowIndex; I <= LastRowIndex; ++I) { 1328 Result.push_back(I); 1329 } 1330 1331 ++SeqPos; 1332 } 1333 1334 return true; 1335 } 1336 1337 Optional<StringRef> DWARFDebugLine::LineTable::getSourceByIndex(uint64_t FileIndex, 1338 FileLineInfoKind Kind) const { 1339 if (Kind == FileLineInfoKind::None || !Prologue.hasFileAtIndex(FileIndex)) 1340 return None; 1341 const FileNameEntry &Entry = Prologue.getFileNameEntry(FileIndex); 1342 if (auto E = dwarf::toString(Entry.Source)) 1343 return StringRef(*E); 1344 return None; 1345 } 1346 1347 static bool isPathAbsoluteOnWindowsOrPosix(const Twine &Path) { 1348 // Debug info can contain paths from any OS, not necessarily 1349 // an OS we're currently running on. Moreover different compilation units can 1350 // be compiled on different operating systems and linked together later. 1351 return sys::path::is_absolute(Path, sys::path::Style::posix) || 1352 sys::path::is_absolute(Path, sys::path::Style::windows); 1353 } 1354 1355 bool DWARFDebugLine::Prologue::getFileNameByIndex( 1356 uint64_t FileIndex, StringRef CompDir, FileLineInfoKind Kind, 1357 std::string &Result, sys::path::Style Style) const { 1358 if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex)) 1359 return false; 1360 const FileNameEntry &Entry = getFileNameEntry(FileIndex); 1361 auto E = dwarf::toString(Entry.Name); 1362 if (!E) 1363 return false; 1364 StringRef FileName = *E; 1365 if (Kind == FileLineInfoKind::RawValue || 1366 isPathAbsoluteOnWindowsOrPosix(FileName)) { 1367 Result = std::string(FileName); 1368 return true; 1369 } 1370 if (Kind == FileLineInfoKind::BaseNameOnly) { 1371 Result = std::string(llvm::sys::path::filename(FileName)); 1372 return true; 1373 } 1374 1375 SmallString<16> FilePath; 1376 StringRef IncludeDir; 1377 // Be defensive about the contents of Entry. 1378 if (getVersion() >= 5) { 1379 // DirIdx 0 is the compilation directory, so don't include it for 1380 // relative names. 1381 if ((Entry.DirIdx != 0 || Kind != FileLineInfoKind::RelativeFilePath) && 1382 Entry.DirIdx < IncludeDirectories.size()) 1383 IncludeDir = dwarf::toStringRef(IncludeDirectories[Entry.DirIdx]); 1384 } else { 1385 if (0 < Entry.DirIdx && Entry.DirIdx <= IncludeDirectories.size()) 1386 IncludeDir = dwarf::toStringRef(IncludeDirectories[Entry.DirIdx - 1]); 1387 } 1388 1389 // For absolute paths only, include the compilation directory of compile unit. 1390 // We know that FileName is not absolute, the only way to have an absolute 1391 // path at this point would be if IncludeDir is absolute. 1392 if (Kind == FileLineInfoKind::AbsoluteFilePath && !CompDir.empty() && 1393 !isPathAbsoluteOnWindowsOrPosix(IncludeDir)) 1394 sys::path::append(FilePath, Style, CompDir); 1395 1396 assert((Kind == FileLineInfoKind::AbsoluteFilePath || 1397 Kind == FileLineInfoKind::RelativeFilePath) && 1398 "invalid FileLineInfo Kind"); 1399 1400 // sys::path::append skips empty strings. 1401 sys::path::append(FilePath, Style, IncludeDir, FileName); 1402 Result = std::string(FilePath.str()); 1403 return true; 1404 } 1405 1406 bool DWARFDebugLine::LineTable::getFileLineInfoForAddress( 1407 object::SectionedAddress Address, const char *CompDir, 1408 FileLineInfoKind Kind, DILineInfo &Result) const { 1409 // Get the index of row we're looking for in the line table. 1410 uint32_t RowIndex = lookupAddress(Address); 1411 if (RowIndex == -1U) 1412 return false; 1413 // Take file number and line/column from the row. 1414 const auto &Row = Rows[RowIndex]; 1415 if (!getFileNameByIndex(Row.File, CompDir, Kind, Result.FileName)) 1416 return false; 1417 Result.Line = Row.Line; 1418 Result.Column = Row.Column; 1419 Result.Discriminator = Row.Discriminator; 1420 Result.Source = getSourceByIndex(Row.File, Kind); 1421 return true; 1422 } 1423 1424 // We want to supply the Unit associated with a .debug_line[.dwo] table when 1425 // we dump it, if possible, but still dump the table even if there isn't a Unit. 1426 // Therefore, collect up handles on all the Units that point into the 1427 // line-table section. 1428 static DWARFDebugLine::SectionParser::LineToUnitMap 1429 buildLineToUnitMap(DWARFUnitVector::iterator_range Units) { 1430 DWARFDebugLine::SectionParser::LineToUnitMap LineToUnit; 1431 for (const auto &U : Units) 1432 if (auto CUDIE = U->getUnitDIE()) 1433 if (auto StmtOffset = toSectionOffset(CUDIE.find(DW_AT_stmt_list))) 1434 LineToUnit.insert(std::make_pair(*StmtOffset, &*U)); 1435 return LineToUnit; 1436 } 1437 1438 DWARFDebugLine::SectionParser::SectionParser( 1439 DWARFDataExtractor &Data, const DWARFContext &C, 1440 DWARFUnitVector::iterator_range Units) 1441 : DebugLineData(Data), Context(C) { 1442 LineToUnit = buildLineToUnitMap(Units); 1443 if (!DebugLineData.isValidOffset(Offset)) 1444 Done = true; 1445 } 1446 1447 bool DWARFDebugLine::Prologue::totalLengthIsValid() const { 1448 return TotalLength != 0u; 1449 } 1450 1451 DWARFDebugLine::LineTable DWARFDebugLine::SectionParser::parseNext( 1452 function_ref<void(Error)> RecoverableErrorHandler, 1453 function_ref<void(Error)> UnrecoverableErrorHandler, raw_ostream *OS, 1454 bool Verbose) { 1455 assert(DebugLineData.isValidOffset(Offset) && 1456 "parsing should have terminated"); 1457 DWARFUnit *U = prepareToParse(Offset); 1458 uint64_t OldOffset = Offset; 1459 LineTable LT; 1460 if (Error Err = LT.parse(DebugLineData, &Offset, Context, U, 1461 RecoverableErrorHandler, OS, Verbose)) 1462 UnrecoverableErrorHandler(std::move(Err)); 1463 moveToNextTable(OldOffset, LT.Prologue); 1464 return LT; 1465 } 1466 1467 void DWARFDebugLine::SectionParser::skip( 1468 function_ref<void(Error)> RecoverableErrorHandler, 1469 function_ref<void(Error)> UnrecoverableErrorHandler) { 1470 assert(DebugLineData.isValidOffset(Offset) && 1471 "parsing should have terminated"); 1472 DWARFUnit *U = prepareToParse(Offset); 1473 uint64_t OldOffset = Offset; 1474 LineTable LT; 1475 if (Error Err = LT.Prologue.parse(DebugLineData, &Offset, 1476 RecoverableErrorHandler, Context, U)) 1477 UnrecoverableErrorHandler(std::move(Err)); 1478 moveToNextTable(OldOffset, LT.Prologue); 1479 } 1480 1481 DWARFUnit *DWARFDebugLine::SectionParser::prepareToParse(uint64_t Offset) { 1482 DWARFUnit *U = nullptr; 1483 auto It = LineToUnit.find(Offset); 1484 if (It != LineToUnit.end()) 1485 U = It->second; 1486 DebugLineData.setAddressSize(U ? U->getAddressByteSize() : 0); 1487 return U; 1488 } 1489 1490 void DWARFDebugLine::SectionParser::moveToNextTable(uint64_t OldOffset, 1491 const Prologue &P) { 1492 // If the length field is not valid, we don't know where the next table is, so 1493 // cannot continue to parse. Mark the parser as done, and leave the Offset 1494 // value as it currently is. This will be the end of the bad length field. 1495 if (!P.totalLengthIsValid()) { 1496 Done = true; 1497 return; 1498 } 1499 1500 Offset = OldOffset + P.TotalLength + P.sizeofTotalLength(); 1501 if (!DebugLineData.isValidOffset(Offset)) { 1502 Done = true; 1503 } 1504 } 1505