1 //===- DWARFDebugLine.h -----------------------------------------*- 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 #ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGLINE_H 10 #define LLVM_DEBUGINFO_DWARF_DWARFDEBUGLINE_H 11 12 #include "llvm/ADT/StringRef.h" 13 #include "llvm/BinaryFormat/Dwarf.h" 14 #include "llvm/DebugInfo/DIContext.h" 15 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 16 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 17 #include "llvm/Support/MD5.h" 18 #include "llvm/Support/Path.h" 19 #include <cstdint> 20 #include <map> 21 #include <string> 22 #include <vector> 23 24 namespace llvm { 25 26 class raw_ostream; 27 28 class DWARFDebugLine { 29 public: 30 struct FileNameEntry { 31 FileNameEntry() = default; 32 33 DWARFFormValue Name; 34 uint64_t DirIdx = 0; 35 uint64_t ModTime = 0; 36 uint64_t Length = 0; 37 MD5::MD5Result Checksum; 38 DWARFFormValue Source; 39 }; 40 41 /// Tracks which optional content types are present in a DWARF file name 42 /// entry format. 43 struct ContentTypeTracker { 44 ContentTypeTracker() = default; 45 46 /// Whether filename entries provide a modification timestamp. 47 bool HasModTime = false; 48 /// Whether filename entries provide a file size. 49 bool HasLength = false; 50 /// For v5, whether filename entries provide an MD5 checksum. 51 bool HasMD5 = false; 52 /// For v5, whether filename entries provide source text. 53 bool HasSource = false; 54 55 /// Update tracked content types with \p ContentType. 56 void trackContentType(dwarf::LineNumberEntryFormat ContentType); 57 }; 58 59 struct Prologue { 60 Prologue(); 61 62 /// The size in bytes of the statement information for this compilation unit 63 /// (not including the total_length field itself). 64 uint64_t TotalLength; 65 /// Version, address size (starting in v5), and DWARF32/64 format; these 66 /// parameters affect interpretation of forms (used in the directory and 67 /// file tables starting with v5). 68 dwarf::FormParams FormParams; 69 /// The number of bytes following the prologue_length field to the beginning 70 /// of the first byte of the statement program itself. 71 uint64_t PrologueLength; 72 /// In v5, size in bytes of a segment selector. 73 uint8_t SegSelectorSize; 74 /// The size in bytes of the smallest target machine instruction. Statement 75 /// program opcodes that alter the address register first multiply their 76 /// operands by this value. 77 uint8_t MinInstLength; 78 /// The maximum number of individual operations that may be encoded in an 79 /// instruction. 80 uint8_t MaxOpsPerInst; 81 /// The initial value of theis_stmtregister. 82 uint8_t DefaultIsStmt; 83 /// This parameter affects the meaning of the special opcodes. See below. 84 int8_t LineBase; 85 /// This parameter affects the meaning of the special opcodes. See below. 86 uint8_t LineRange; 87 /// The number assigned to the first special opcode. 88 uint8_t OpcodeBase; 89 /// This tracks which optional file format content types are present. 90 ContentTypeTracker ContentTypes; 91 std::vector<uint8_t> StandardOpcodeLengths; 92 std::vector<DWARFFormValue> IncludeDirectories; 93 std::vector<FileNameEntry> FileNames; 94 95 const dwarf::FormParams getFormParams() const { return FormParams; } 96 uint16_t getVersion() const { return FormParams.Version; } 97 uint8_t getAddressSize() const { return FormParams.AddrSize; } 98 bool isDWARF64() const { return FormParams.Format == dwarf::DWARF64; } 99 100 uint32_t sizeofTotalLength() const { return isDWARF64() ? 12 : 4; } 101 102 uint32_t sizeofPrologueLength() const { return isDWARF64() ? 8 : 4; } 103 104 bool totalLengthIsValid() const; 105 106 /// Length of the prologue in bytes. 107 uint64_t getLength() const; 108 109 /// Get DWARF-version aware access to the file name entry at the provided 110 /// index. 111 const llvm::DWARFDebugLine::FileNameEntry & 112 getFileNameEntry(uint64_t Index) const; 113 114 bool hasFileAtIndex(uint64_t FileIndex) const; 115 116 std::optional<uint64_t> getLastValidFileIndex() const; 117 118 bool 119 getFileNameByIndex(uint64_t FileIndex, StringRef CompDir, 120 DILineInfoSpecifier::FileLineInfoKind Kind, 121 std::string &Result, 122 sys::path::Style Style = sys::path::Style::native) const; 123 124 void clear(); 125 void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const; 126 Error parse(DWARFDataExtractor Data, uint64_t *OffsetPtr, 127 function_ref<void(Error)> RecoverableErrorHandler, 128 const DWARFContext &Ctx, const DWARFUnit *U = nullptr); 129 }; 130 131 /// Standard .debug_line state machine structure. 132 struct Row { 133 explicit Row(bool DefaultIsStmt = false); 134 135 /// Called after a row is appended to the matrix. 136 void postAppend(); 137 void reset(bool DefaultIsStmt); 138 void dump(raw_ostream &OS) const; 139 140 static void dumpTableHeader(raw_ostream &OS, unsigned Indent); 141 142 static bool orderByAddress(const Row &LHS, const Row &RHS) { 143 return std::tie(LHS.Address.SectionIndex, LHS.Address.Address) < 144 std::tie(RHS.Address.SectionIndex, RHS.Address.Address); 145 } 146 147 /// The program-counter value corresponding to a machine instruction 148 /// generated by the compiler and section index pointing to the section 149 /// containg this PC. If relocation information is present then section 150 /// index is the index of the section which contains above address. 151 /// Otherwise this is object::SectionedAddress::Undef value. 152 object::SectionedAddress Address; 153 /// An unsigned integer indicating a source line number. Lines are numbered 154 /// beginning at 1. The compiler may emit the value 0 in cases where an 155 /// instruction cannot be attributed to any source line. 156 uint32_t Line; 157 /// An unsigned integer indicating a column number within a source line. 158 /// Columns are numbered beginning at 1. The value 0 is reserved to indicate 159 /// that a statement begins at the 'left edge' of the line. 160 uint16_t Column; 161 /// An unsigned integer indicating the identity of the source file 162 /// corresponding to a machine instruction. 163 uint16_t File; 164 /// An unsigned integer representing the DWARF path discriminator value 165 /// for this location. 166 uint32_t Discriminator; 167 /// An unsigned integer whose value encodes the applicable instruction set 168 /// architecture for the current instruction. 169 uint8_t Isa; 170 /// An unsigned integer representing the index of an operation within a 171 /// VLIW instruction. The index of the first operation is 0. 172 /// For non-VLIW architectures, this register will always be 0. 173 uint8_t OpIndex; 174 /// A boolean indicating that the current instruction is the beginning of a 175 /// statement. 176 uint8_t IsStmt : 1, 177 /// A boolean indicating that the current instruction is the 178 /// beginning of a basic block. 179 BasicBlock : 1, 180 /// A boolean indicating that the current address is that of the 181 /// first byte after the end of a sequence of target machine 182 /// instructions. 183 EndSequence : 1, 184 /// A boolean indicating that the current address is one (of possibly 185 /// many) where execution should be suspended for an entry breakpoint 186 /// of a function. 187 PrologueEnd : 1, 188 /// A boolean indicating that the current address is one (of possibly 189 /// many) where execution should be suspended for an exit breakpoint 190 /// of a function. 191 EpilogueBegin : 1; 192 }; 193 194 /// Represents a series of contiguous machine instructions. Line table for 195 /// each compilation unit may consist of multiple sequences, which are not 196 /// guaranteed to be in the order of ascending instruction address. 197 struct Sequence { 198 Sequence(); 199 200 /// Sequence describes instructions at address range [LowPC, HighPC) 201 /// and is described by line table rows [FirstRowIndex, LastRowIndex). 202 uint64_t LowPC; 203 uint64_t HighPC; 204 /// If relocation information is present then this is the index of the 205 /// section which contains above addresses. Otherwise this is 206 /// object::SectionedAddress::Undef value. 207 uint64_t SectionIndex; 208 unsigned FirstRowIndex; 209 unsigned LastRowIndex; 210 bool Empty; 211 212 void reset(); 213 214 static bool orderByHighPC(const Sequence &LHS, const Sequence &RHS) { 215 return std::tie(LHS.SectionIndex, LHS.HighPC) < 216 std::tie(RHS.SectionIndex, RHS.HighPC); 217 } 218 219 bool isValid() const { 220 return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex); 221 } 222 223 bool containsPC(object::SectionedAddress PC) const { 224 return SectionIndex == PC.SectionIndex && 225 (LowPC <= PC.Address && PC.Address < HighPC); 226 } 227 }; 228 229 struct LineTable { 230 LineTable(); 231 232 /// Represents an invalid row 233 const uint32_t UnknownRowIndex = UINT32_MAX; 234 235 void appendRow(const DWARFDebugLine::Row &R) { Rows.push_back(R); } 236 237 void appendSequence(const DWARFDebugLine::Sequence &S) { 238 Sequences.push_back(S); 239 } 240 241 /// Returns the index of the row with file/line info for a given address, 242 /// or UnknownRowIndex if there is no such row. 243 uint32_t lookupAddress(object::SectionedAddress Address) const; 244 245 bool lookupAddressRange(object::SectionedAddress Address, uint64_t Size, 246 std::vector<uint32_t> &Result) const; 247 248 bool hasFileAtIndex(uint64_t FileIndex) const { 249 return Prologue.hasFileAtIndex(FileIndex); 250 } 251 252 std::optional<uint64_t> getLastValidFileIndex() const { 253 return Prologue.getLastValidFileIndex(); 254 } 255 256 /// Extracts filename by its index in filename table in prologue. 257 /// In Dwarf 4, the files are 1-indexed and the current compilation file 258 /// name is not represented in the list. In DWARF v5, the files are 259 /// 0-indexed and the primary source file has the index 0. 260 /// Returns true on success. 261 bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir, 262 DILineInfoSpecifier::FileLineInfoKind Kind, 263 std::string &Result) const { 264 return Prologue.getFileNameByIndex(FileIndex, CompDir, Kind, Result); 265 } 266 267 /// Fills the Result argument with the file and line information 268 /// corresponding to Address. Returns true on success. 269 bool getFileLineInfoForAddress(object::SectionedAddress Address, 270 const char *CompDir, 271 DILineInfoSpecifier::FileLineInfoKind Kind, 272 DILineInfo &Result) const; 273 274 /// Extracts directory name by its Entry in include directories table 275 /// in prologue. Returns true on success. 276 bool getDirectoryForEntry(const FileNameEntry &Entry, 277 std::string &Directory) const; 278 279 void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const; 280 void clear(); 281 282 /// Parse prologue and all rows. 283 Error parse(DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, 284 const DWARFContext &Ctx, const DWARFUnit *U, 285 function_ref<void(Error)> RecoverableErrorHandler, 286 raw_ostream *OS = nullptr, bool Verbose = false); 287 288 using RowVector = std::vector<Row>; 289 using RowIter = RowVector::const_iterator; 290 using SequenceVector = std::vector<Sequence>; 291 using SequenceIter = SequenceVector::const_iterator; 292 293 struct Prologue Prologue; 294 RowVector Rows; 295 SequenceVector Sequences; 296 297 private: 298 uint32_t findRowInSeq(const DWARFDebugLine::Sequence &Seq, 299 object::SectionedAddress Address) const; 300 std::optional<StringRef> 301 getSourceByIndex(uint64_t FileIndex, 302 DILineInfoSpecifier::FileLineInfoKind Kind) const; 303 304 uint32_t lookupAddressImpl(object::SectionedAddress Address) const; 305 306 bool lookupAddressRangeImpl(object::SectionedAddress Address, uint64_t Size, 307 std::vector<uint32_t> &Result) const; 308 }; 309 310 const LineTable *getLineTable(uint64_t Offset) const; 311 Expected<const LineTable *> 312 getOrParseLineTable(DWARFDataExtractor &DebugLineData, uint64_t Offset, 313 const DWARFContext &Ctx, const DWARFUnit *U, 314 function_ref<void(Error)> RecoverableErrorHandler); 315 void clearLineTable(uint64_t Offset); 316 317 /// Helper to allow for parsing of an entire .debug_line section in sequence. 318 class SectionParser { 319 public: 320 using LineToUnitMap = std::map<uint64_t, DWARFUnit *>; 321 322 SectionParser(DWARFDataExtractor &Data, const DWARFContext &C, 323 DWARFUnitVector::iterator_range Units); 324 325 /// Get the next line table from the section. Report any issues via the 326 /// handlers. 327 /// 328 /// \param RecoverableErrorHandler - any issues that don't prevent further 329 /// parsing of the table will be reported through this handler. 330 /// \param UnrecoverableErrorHandler - any issues that prevent further 331 /// parsing of the table will be reported through this handler. 332 /// \param OS - if not null, the parser will print information about the 333 /// table as it parses it. 334 /// \param Verbose - if true, the parser will print verbose information when 335 /// printing to the output. 336 LineTable parseNext(function_ref<void(Error)> RecoverableErrorHandler, 337 function_ref<void(Error)> UnrecoverableErrorHandler, 338 raw_ostream *OS = nullptr, bool Verbose = false); 339 340 /// Skip the current line table and go to the following line table (if 341 /// present) immediately. 342 /// 343 /// \param RecoverableErrorHandler - report any recoverable prologue 344 /// parsing issues via this handler. 345 /// \param UnrecoverableErrorHandler - report any unrecoverable prologue 346 /// parsing issues via this handler. 347 void skip(function_ref<void(Error)> RecoverableErrorHandler, 348 function_ref<void(Error)> UnrecoverableErrorHandler); 349 350 /// Indicates if the parser has parsed as much as possible. 351 /// 352 /// \note Certain problems with the line table structure might mean that 353 /// parsing stops before the end of the section is reached. 354 bool done() const { return Done; } 355 356 /// Get the offset the parser has reached. 357 uint64_t getOffset() const { return Offset; } 358 359 private: 360 DWARFUnit *prepareToParse(uint64_t Offset); 361 void moveToNextTable(uint64_t OldOffset, const Prologue &P); 362 bool hasValidVersion(uint64_t Offset); 363 364 LineToUnitMap LineToUnit; 365 366 DWARFDataExtractor &DebugLineData; 367 const DWARFContext &Context; 368 uint64_t Offset = 0; 369 bool Done = false; 370 }; 371 372 private: 373 struct ParsingState { 374 ParsingState(struct LineTable *LT, uint64_t TableOffset, 375 function_ref<void(Error)> ErrorHandler); 376 377 void resetRowAndSequence(); 378 void appendRowToMatrix(); 379 380 struct AddrOpIndexDelta { 381 uint64_t AddrOffset; 382 int16_t OpIndexDelta; 383 }; 384 385 /// Advance the address and op-index by the \p OperationAdvance value. 386 /// \returns the amount advanced by. 387 AddrOpIndexDelta advanceAddrOpIndex(uint64_t OperationAdvance, 388 uint8_t Opcode, uint64_t OpcodeOffset); 389 390 struct OpcodeAdvanceResults { 391 uint64_t AddrDelta; 392 int16_t OpIndexDelta; 393 uint8_t AdjustedOpcode; 394 }; 395 396 /// Advance the address and op-index as required by the specified \p Opcode. 397 /// \returns the amount advanced by and the calculated adjusted opcode. 398 OpcodeAdvanceResults advanceForOpcode(uint8_t Opcode, 399 uint64_t OpcodeOffset); 400 401 struct SpecialOpcodeDelta { 402 uint64_t Address; 403 int32_t Line; 404 int16_t OpIndex; 405 }; 406 407 /// Advance the line, address and op-index as required by the specified 408 /// special \p Opcode. \returns the address, op-index and line delta. 409 SpecialOpcodeDelta handleSpecialOpcode(uint8_t Opcode, 410 uint64_t OpcodeOffset); 411 412 /// Line table we're currently parsing. 413 struct LineTable *LineTable; 414 struct Row Row; 415 struct Sequence Sequence; 416 417 private: 418 uint64_t LineTableOffset; 419 420 bool ReportAdvanceAddrProblem = true; 421 bool ReportBadLineRange = true; 422 function_ref<void(Error)> ErrorHandler; 423 }; 424 425 using LineTableMapTy = std::map<uint64_t, LineTable>; 426 using LineTableIter = LineTableMapTy::iterator; 427 using LineTableConstIter = LineTableMapTy::const_iterator; 428 429 LineTableMapTy LineTableMap; 430 }; 431 432 } // end namespace llvm 433 434 #endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGLINE_H 435