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_DWARFDEBUGLINE_H 10 #define LLVM_DEBUGINFO_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 bool 125 getFileNameByIndex(uint64_t FileIndex, StringRef CompDir, 126 DILineInfoSpecifier::FileLineInfoKind Kind, 127 std::string &Result, 128 sys::path::Style Style = sys::path::Style::native) const; 129 130 void clear(); 131 void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const; 132 Error parse(DWARFDataExtractor Data, uint64_t *OffsetPtr, 133 function_ref<void(Error)> RecoverableErrorHandler, 134 const DWARFContext &Ctx, const DWARFUnit *U = nullptr); 135 }; 136 137 /// Standard .debug_line state machine structure. 138 struct Row { 139 explicit Row(bool DefaultIsStmt = false); 140 141 /// Called after a row is appended to the matrix. 142 void postAppend(); 143 void reset(bool DefaultIsStmt); 144 void dump(raw_ostream &OS) const; 145 146 static void dumpTableHeader(raw_ostream &OS, unsigned Indent); 147 148 static bool orderByAddress(const Row &LHS, const Row &RHS) { 149 return std::tie(LHS.Address.SectionIndex, LHS.Address.Address) < 150 std::tie(RHS.Address.SectionIndex, RHS.Address.Address); 151 } 152 153 /// The program-counter value corresponding to a machine instruction 154 /// generated by the compiler and section index pointing to the section 155 /// containg this PC. If relocation information is present then section 156 /// index is the index of the section which contains above address. 157 /// Otherwise this is object::SectionedAddress::Undef value. 158 object::SectionedAddress Address; 159 /// An unsigned integer indicating a source line number. Lines are numbered 160 /// beginning at 1. The compiler may emit the value 0 in cases where an 161 /// instruction cannot be attributed to any source line. 162 uint32_t Line; 163 /// An unsigned integer indicating a column number within a source line. 164 /// Columns are numbered beginning at 1. The value 0 is reserved to indicate 165 /// that a statement begins at the 'left edge' of the line. 166 uint16_t Column; 167 /// An unsigned integer indicating the identity of the source file 168 /// corresponding to a machine instruction. 169 uint16_t File; 170 /// An unsigned integer representing the DWARF path discriminator value 171 /// for this location. 172 uint32_t Discriminator; 173 /// An unsigned integer whose value encodes the applicable instruction set 174 /// architecture for the current instruction. 175 uint8_t Isa; 176 /// A boolean indicating that the current instruction is the beginning of a 177 /// statement. 178 uint8_t IsStmt : 1, 179 /// A boolean indicating that the current instruction is the 180 /// beginning of a basic block. 181 BasicBlock : 1, 182 /// A boolean indicating that the current address is that of the 183 /// first byte after the end of a sequence of target machine 184 /// instructions. 185 EndSequence : 1, 186 /// A boolean indicating that the current address is one (of possibly 187 /// many) where execution should be suspended for an entry breakpoint 188 /// of a function. 189 PrologueEnd : 1, 190 /// A boolean indicating that the current address is one (of possibly 191 /// many) where execution should be suspended for an exit breakpoint 192 /// of a function. 193 EpilogueBegin : 1; 194 }; 195 196 /// Represents a series of contiguous machine instructions. Line table for 197 /// each compilation unit may consist of multiple sequences, which are not 198 /// guaranteed to be in the order of ascending instruction address. 199 struct Sequence { 200 Sequence(); 201 202 /// Sequence describes instructions at address range [LowPC, HighPC) 203 /// and is described by line table rows [FirstRowIndex, LastRowIndex). 204 uint64_t LowPC; 205 uint64_t HighPC; 206 /// If relocation information is present then this is the index of the 207 /// section which contains above addresses. Otherwise this is 208 /// object::SectionedAddress::Undef value. 209 uint64_t SectionIndex; 210 unsigned FirstRowIndex; 211 unsigned LastRowIndex; 212 bool Empty; 213 214 void reset(); 215 216 static bool orderByHighPC(const Sequence &LHS, const Sequence &RHS) { 217 return std::tie(LHS.SectionIndex, LHS.HighPC) < 218 std::tie(RHS.SectionIndex, RHS.HighPC); 219 } 220 221 bool isValid() const { 222 return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex); 223 } 224 225 bool containsPC(object::SectionedAddress PC) const { 226 return SectionIndex == PC.SectionIndex && 227 (LowPC <= PC.Address && PC.Address < HighPC); 228 } 229 }; 230 231 struct LineTable { 232 LineTable(); 233 234 /// Represents an invalid row 235 const uint32_t UnknownRowIndex = UINT32_MAX; 236 237 void appendRow(const DWARFDebugLine::Row &R) { Rows.push_back(R); } 238 239 void appendSequence(const DWARFDebugLine::Sequence &S) { 240 Sequences.push_back(S); 241 } 242 243 /// Returns the index of the row with file/line info for a given address, 244 /// or UnknownRowIndex if there is no such row. 245 uint32_t lookupAddress(object::SectionedAddress Address) const; 246 247 bool lookupAddressRange(object::SectionedAddress Address, uint64_t Size, 248 std::vector<uint32_t> &Result) const; 249 250 bool hasFileAtIndex(uint64_t FileIndex) const { 251 return Prologue.hasFileAtIndex(FileIndex); 252 } 253 254 /// Extracts filename by its index in filename table in prologue. 255 /// In Dwarf 4, the files are 1-indexed and the current compilation file 256 /// name is not represented in the list. In DWARF v5, the files are 257 /// 0-indexed and the primary source file has the index 0. 258 /// Returns true on success. 259 bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir, 260 DILineInfoSpecifier::FileLineInfoKind Kind, 261 std::string &Result) const { 262 return Prologue.getFileNameByIndex(FileIndex, CompDir, Kind, Result); 263 } 264 265 /// Fills the Result argument with the file and line information 266 /// corresponding to Address. Returns true on success. 267 bool getFileLineInfoForAddress(object::SectionedAddress Address, 268 const char *CompDir, 269 DILineInfoSpecifier::FileLineInfoKind Kind, 270 DILineInfo &Result) const; 271 272 void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const; 273 void clear(); 274 275 /// Parse prologue and all rows. 276 Error parse(DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, 277 const DWARFContext &Ctx, const DWARFUnit *U, 278 function_ref<void(Error)> RecoverableErrorHandler, 279 raw_ostream *OS = nullptr, bool Verbose = false); 280 281 using RowVector = std::vector<Row>; 282 using RowIter = RowVector::const_iterator; 283 using SequenceVector = std::vector<Sequence>; 284 using SequenceIter = SequenceVector::const_iterator; 285 286 struct Prologue Prologue; 287 RowVector Rows; 288 SequenceVector Sequences; 289 290 private: 291 uint32_t findRowInSeq(const DWARFDebugLine::Sequence &Seq, 292 object::SectionedAddress Address) const; 293 Optional<StringRef> 294 getSourceByIndex(uint64_t FileIndex, 295 DILineInfoSpecifier::FileLineInfoKind Kind) const; 296 297 uint32_t lookupAddressImpl(object::SectionedAddress Address) const; 298 299 bool lookupAddressRangeImpl(object::SectionedAddress Address, uint64_t Size, 300 std::vector<uint32_t> &Result) const; 301 }; 302 303 const LineTable *getLineTable(uint64_t Offset) const; 304 Expected<const LineTable *> 305 getOrParseLineTable(DWARFDataExtractor &DebugLineData, uint64_t Offset, 306 const DWARFContext &Ctx, const DWARFUnit *U, 307 function_ref<void(Error)> RecoverableErrorHandler); 308 309 /// Helper to allow for parsing of an entire .debug_line section in sequence. 310 class SectionParser { 311 public: 312 using cu_range = DWARFUnitVector::iterator_range; 313 using tu_range = DWARFUnitVector::iterator_range; 314 using LineToUnitMap = std::map<uint64_t, DWARFUnit *>; 315 316 SectionParser(DWARFDataExtractor &Data, const DWARFContext &C, cu_range CUs, 317 tu_range TUs); 318 319 /// Get the next line table from the section. Report any issues via the 320 /// handlers. 321 /// 322 /// \param RecoverableErrorHandler - any issues that don't prevent further 323 /// parsing of the table will be reported through this handler. 324 /// \param UnrecoverableErrorHandler - any issues that prevent further 325 /// parsing of the table will be reported through this handler. 326 /// \param OS - if not null, the parser will print information about the 327 /// table as it parses it. 328 /// \param Verbose - if true, the parser will print verbose information when 329 /// printing to the output. 330 LineTable parseNext(function_ref<void(Error)> RecoverableErrorHandler, 331 function_ref<void(Error)> UnrecoverableErrorHandler, 332 raw_ostream *OS = nullptr, bool Verbose = false); 333 334 /// Skip the current line table and go to the following line table (if 335 /// present) immediately. 336 /// 337 /// \param RecoverableErrorHandler - report any recoverable prologue 338 /// parsing issues via this handler. 339 /// \param UnrecoverableErrorHandler - report any unrecoverable prologue 340 /// parsing issues via this handler. 341 void skip(function_ref<void(Error)> RecoverableErrorHandler, 342 function_ref<void(Error)> UnrecoverableErrorHandler); 343 344 /// Indicates if the parser has parsed as much as possible. 345 /// 346 /// \note Certain problems with the line table structure might mean that 347 /// parsing stops before the end of the section is reached. 348 bool done() const { return Done; } 349 350 /// Get the offset the parser has reached. 351 uint64_t getOffset() const { return Offset; } 352 353 private: 354 DWARFUnit *prepareToParse(uint64_t Offset); 355 void moveToNextTable(uint64_t OldOffset, const Prologue &P); 356 357 LineToUnitMap LineToUnit; 358 359 DWARFDataExtractor &DebugLineData; 360 const DWARFContext &Context; 361 uint64_t Offset = 0; 362 bool Done = false; 363 }; 364 365 private: 366 struct ParsingState { 367 ParsingState(struct LineTable *LT, uint64_t TableOffset, 368 function_ref<void(Error)> ErrorHandler); 369 370 void resetRowAndSequence(); 371 void appendRowToMatrix(); 372 373 /// Advance the address by the \p OperationAdvance value. \returns the 374 /// amount advanced by. 375 uint64_t advanceAddr(uint64_t OperationAdvance, uint8_t Opcode, 376 uint64_t OpcodeOffset); 377 378 struct AddrAndAdjustedOpcode { 379 uint64_t AddrDelta; 380 uint8_t AdjustedOpcode; 381 }; 382 383 /// Advance the address as required by the specified \p Opcode. 384 /// \returns the amount advanced by and the calculated adjusted opcode. 385 AddrAndAdjustedOpcode advanceAddrForOpcode(uint8_t Opcode, 386 uint64_t OpcodeOffset); 387 388 struct AddrAndLineDelta { 389 uint64_t Address; 390 int32_t Line; 391 }; 392 393 /// Advance the line and address as required by the specified special \p 394 /// Opcode. \returns the address and line delta. 395 AddrAndLineDelta handleSpecialOpcode(uint8_t Opcode, uint64_t OpcodeOffset); 396 397 /// Line table we're currently parsing. 398 struct LineTable *LineTable; 399 struct Row Row; 400 struct Sequence Sequence; 401 402 private: 403 uint64_t LineTableOffset; 404 405 bool ReportAdvanceAddrProblem = true; 406 bool ReportBadLineRange = true; 407 function_ref<void(Error)> ErrorHandler; 408 }; 409 410 using LineTableMapTy = std::map<uint64_t, LineTable>; 411 using LineTableIter = LineTableMapTy::iterator; 412 using LineTableConstIter = LineTableMapTy::const_iterator; 413 414 LineTableMapTy LineTableMap; 415 }; 416 417 } // end namespace llvm 418 419 #endif // LLVM_DEBUGINFO_DWARFDEBUGLINE_H 420