1 //===-- DWARFDebugLine.h ----------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_DEBUGINFO_DWARFDEBUGLINE_H 11 #define LLVM_DEBUGINFO_DWARFDEBUGLINE_H 12 13 #include "DWARFRelocMap.h" 14 #include "llvm/DebugInfo/DIContext.h" 15 #include "llvm/Support/DataExtractor.h" 16 #include <map> 17 #include <string> 18 #include <vector> 19 20 namespace llvm { 21 22 class raw_ostream; 23 24 class DWARFDebugLine { 25 public: 26 DWARFDebugLine(const RelocAddrMap* LineInfoRelocMap) : RelocMap(LineInfoRelocMap) {} 27 struct FileNameEntry { 28 FileNameEntry() : Name(nullptr), DirIdx(0), ModTime(0), Length(0) {} 29 30 const char *Name; 31 uint64_t DirIdx; 32 uint64_t ModTime; 33 uint64_t Length; 34 }; 35 36 struct Prologue { 37 Prologue(); 38 39 // The size in bytes of the statement information for this compilation unit 40 // (not including the total_length field itself). 41 uint32_t TotalLength; 42 // Version identifier for the statement information format. 43 uint16_t Version; 44 // The number of bytes following the prologue_length field to the beginning 45 // of the first byte of the statement program itself. 46 uint32_t PrologueLength; 47 // The size in bytes of the smallest target machine instruction. Statement 48 // program opcodes that alter the address register first multiply their 49 // operands by this value. 50 uint8_t MinInstLength; 51 // The maximum number of individual operations that may be encoded in an 52 // instruction. 53 uint8_t MaxOpsPerInst; 54 // The initial value of theis_stmtregister. 55 uint8_t DefaultIsStmt; 56 // This parameter affects the meaning of the special opcodes. See below. 57 int8_t LineBase; 58 // This parameter affects the meaning of the special opcodes. See below. 59 uint8_t LineRange; 60 // The number assigned to the first special opcode. 61 uint8_t OpcodeBase; 62 std::vector<uint8_t> StandardOpcodeLengths; 63 std::vector<const char*> IncludeDirectories; 64 std::vector<FileNameEntry> FileNames; 65 66 // Length of the prologue in bytes. 67 uint32_t getLength() const { 68 return PrologueLength + sizeof(TotalLength) + sizeof(Version) + 69 sizeof(PrologueLength); 70 } 71 // Length of the line table data in bytes (not including the prologue). 72 uint32_t getStatementTableLength() const { 73 return TotalLength + sizeof(TotalLength) - getLength(); 74 } 75 int32_t getMaxLineIncrementForSpecialOpcode() const { 76 return LineBase + (int8_t)LineRange - 1; 77 } 78 79 void clear(); 80 void dump(raw_ostream &OS) const; 81 bool parse(DataExtractor debug_line_data, uint32_t *offset_ptr); 82 }; 83 84 // Standard .debug_line state machine structure. 85 struct Row { 86 explicit Row(bool default_is_stmt = false); 87 88 /// Called after a row is appended to the matrix. 89 void postAppend(); 90 void reset(bool default_is_stmt); 91 void dump(raw_ostream &OS) const; 92 93 static bool orderByAddress(const Row& LHS, const Row& RHS) { 94 return LHS.Address < RHS.Address; 95 } 96 97 // The program-counter value corresponding to a machine instruction 98 // generated by the compiler. 99 uint64_t Address; 100 // An unsigned integer indicating a source line number. Lines are numbered 101 // beginning at 1. The compiler may emit the value 0 in cases where an 102 // instruction cannot be attributed to any source line. 103 uint32_t Line; 104 // An unsigned integer indicating a column number within a source line. 105 // Columns are numbered beginning at 1. The value 0 is reserved to indicate 106 // that a statement begins at the 'left edge' of the line. 107 uint16_t Column; 108 // An unsigned integer indicating the identity of the source file 109 // corresponding to a machine instruction. 110 uint16_t File; 111 // An unsigned integer whose value encodes the applicable instruction set 112 // architecture for the current instruction. 113 uint8_t Isa; 114 // An unsigned integer representing the DWARF path discriminator value 115 // for this location. 116 uint32_t Discriminator; 117 // A boolean indicating that the current instruction is the beginning of a 118 // statement. 119 uint8_t IsStmt:1, 120 // A boolean indicating that the current instruction is the 121 // beginning of a basic block. 122 BasicBlock:1, 123 // A boolean indicating that the current address is that of the 124 // first byte after the end of a sequence of target machine 125 // instructions. 126 EndSequence:1, 127 // A boolean indicating that the current address is one (of possibly 128 // many) where execution should be suspended for an entry breakpoint 129 // of a function. 130 PrologueEnd:1, 131 // A boolean indicating that the current address is one (of possibly 132 // many) where execution should be suspended for an exit breakpoint 133 // of a function. 134 EpilogueBegin:1; 135 }; 136 137 // Represents a series of contiguous machine instructions. Line table for each 138 // compilation unit may consist of multiple sequences, which are not 139 // guaranteed to be in the order of ascending instruction address. 140 struct Sequence { 141 // Sequence describes instructions at address range [LowPC, HighPC) 142 // and is described by line table rows [FirstRowIndex, LastRowIndex). 143 uint64_t LowPC; 144 uint64_t HighPC; 145 unsigned FirstRowIndex; 146 unsigned LastRowIndex; 147 bool Empty; 148 149 Sequence(); 150 void reset(); 151 152 static bool orderByLowPC(const Sequence& LHS, const Sequence& RHS) { 153 return LHS.LowPC < RHS.LowPC; 154 } 155 bool isValid() const { 156 return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex); 157 } 158 bool containsPC(uint64_t pc) const { 159 return (LowPC <= pc && pc < HighPC); 160 } 161 }; 162 163 struct LineTable { 164 LineTable(); 165 166 void appendRow(const DWARFDebugLine::Row &R) { 167 Rows.push_back(R); 168 } 169 void appendSequence(const DWARFDebugLine::Sequence &S) { 170 Sequences.push_back(S); 171 } 172 173 // Returns the index of the row with file/line info for a given address, 174 // or -1 if there is no such row. 175 uint32_t lookupAddress(uint64_t address) const; 176 177 bool lookupAddressRange(uint64_t address, uint64_t size, 178 std::vector<uint32_t> &result) const; 179 180 // Extracts filename by its index in filename table in prologue. 181 // Returns true on success. 182 bool getFileNameByIndex(uint64_t FileIndex, 183 DILineInfoSpecifier::FileLineInfoKind Kind, 184 std::string &Result) const; 185 186 void dump(raw_ostream &OS) const; 187 void clear(); 188 189 /// Parse prologue and all rows. 190 bool parse(DataExtractor debug_line_data, const RelocAddrMap *RMap, 191 uint32_t *offset_ptr); 192 193 struct Prologue Prologue; 194 typedef std::vector<Row> RowVector; 195 typedef RowVector::const_iterator RowIter; 196 typedef std::vector<Sequence> SequenceVector; 197 typedef SequenceVector::const_iterator SequenceIter; 198 RowVector Rows; 199 SequenceVector Sequences; 200 }; 201 202 const LineTable *getLineTable(uint32_t offset) const; 203 const LineTable *getOrParseLineTable(DataExtractor debug_line_data, 204 uint32_t offset); 205 206 private: 207 struct ParsingState { 208 ParsingState(struct LineTable *LT); 209 210 void resetRowAndSequence(); 211 void appendRowToMatrix(uint32_t offset); 212 213 // Line table we're currently parsing. 214 struct LineTable *LineTable; 215 // The row number that starts at zero for the prologue, and increases for 216 // each row added to the matrix. 217 unsigned RowNumber; 218 struct Row Row; 219 struct Sequence Sequence; 220 }; 221 222 typedef std::map<uint32_t, LineTable> LineTableMapTy; 223 typedef LineTableMapTy::iterator LineTableIter; 224 typedef LineTableMapTy::const_iterator LineTableConstIter; 225 226 const RelocAddrMap *RelocMap; 227 LineTableMapTy LineTableMap; 228 }; 229 230 } 231 232 #endif 233
