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