Home | History | Annotate | Download | only in DebugInfo
      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/Support/DataExtractor.h"
     15 #include <map>
     16 #include <string>
     17 #include <vector>
     18 
     19 namespace llvm {
     20 
     21 class raw_ostream;
     22 
     23 class DWARFDebugLine {
     24 public:
     25   DWARFDebugLine(const RelocAddrMap* LineInfoRelocMap) : RelocMap(LineInfoRelocMap) {}
     26   struct FileNameEntry {
     27     FileNameEntry() : Name(0), DirIdx(0), ModTime(0), Length(0) {}
     28 
     29     const char *Name;
     30     uint64_t DirIdx;
     31     uint64_t ModTime;
     32     uint64_t Length;
     33   };
     34 
     35   struct Prologue {
     36     Prologue()
     37       : TotalLength(0), Version(0), PrologueLength(0), MinInstLength(0),
     38         DefaultIsStmt(0), LineBase(0), LineRange(0), OpcodeBase(0) {}
     39 
     40     // The size in bytes of the statement information for this compilation unit
     41     // (not including the total_length field itself).
     42     uint32_t TotalLength;
     43     // Version identifier for the statement information format.
     44     uint16_t Version;
     45     // The number of bytes following the prologue_length field to the beginning
     46     // of the first byte of the statement program itself.
     47     uint32_t PrologueLength;
     48     // The size in bytes of the smallest target machine instruction. Statement
     49     // program opcodes that alter the address register first multiply their
     50     // operands by this value.
     51     uint8_t MinInstLength;
     52     // The initial value of theis_stmtregister.
     53     uint8_t DefaultIsStmt;
     54     // This parameter affects the meaning of the special opcodes. See below.
     55     int8_t LineBase;
     56     // This parameter affects the meaning of the special opcodes. See below.
     57     uint8_t LineRange;
     58     // The number assigned to the first special opcode.
     59     uint8_t OpcodeBase;
     60     std::vector<uint8_t> StandardOpcodeLengths;
     61     std::vector<const char*> IncludeDirectories;
     62     std::vector<FileNameEntry> FileNames;
     63 
     64     // Length of the prologue in bytes.
     65     uint32_t getLength() const {
     66       return PrologueLength + sizeof(TotalLength) + sizeof(Version) +
     67              sizeof(PrologueLength);
     68     }
     69     // Length of the line table data in bytes (not including the prologue).
     70     uint32_t getStatementTableLength() const {
     71       return TotalLength + sizeof(TotalLength) - getLength();
     72     }
     73     int32_t getMaxLineIncrementForSpecialOpcode() const {
     74       return LineBase + (int8_t)LineRange - 1;
     75     }
     76     void dump(raw_ostream &OS) const;
     77     void clear() {
     78       TotalLength = Version = PrologueLength = 0;
     79       MinInstLength = LineBase = LineRange = OpcodeBase = 0;
     80       StandardOpcodeLengths.clear();
     81       IncludeDirectories.clear();
     82       FileNames.clear();
     83     }
     84   };
     85 
     86   // Standard .debug_line state machine structure.
     87   struct Row {
     88     Row(bool default_is_stmt = false) { reset(default_is_stmt); }
     89     /// Called after a row is appended to the matrix.
     90     void postAppend();
     91     void reset(bool default_is_stmt);
     92     void dump(raw_ostream &OS) const;
     93 
     94     static bool orderByAddress(const Row& LHS, const Row& RHS) {
     95       return LHS.Address < RHS.Address;
     96     }
     97 
     98     // The program-counter value corresponding to a machine instruction
     99     // generated by the compiler.
    100     uint64_t Address;
    101     // An unsigned integer indicating a source line number. Lines are numbered
    102     // beginning at 1. The compiler may emit the value 0 in cases where an
    103     // instruction cannot be attributed to any source line.
    104     uint32_t Line;
    105     // An unsigned integer indicating a column number within a source line.
    106     // Columns are numbered beginning at 1. The value 0 is reserved to indicate
    107     // that a statement begins at the 'left edge' of the line.
    108     uint16_t Column;
    109     // An unsigned integer indicating the identity of the source file
    110     // corresponding to a machine instruction.
    111     uint16_t File;
    112     // An unsigned integer whose value encodes the applicable instruction set
    113     // architecture for the current instruction.
    114     uint8_t Isa;
    115     // A boolean indicating that the current instruction is the beginning of a
    116     // statement.
    117     uint8_t IsStmt:1,
    118             // A boolean indicating that the current instruction is the
    119             // beginning of a basic block.
    120             BasicBlock:1,
    121             // A boolean indicating that the current address is that of the
    122             // first byte after the end of a sequence of target machine
    123             // instructions.
    124             EndSequence:1,
    125             // A boolean indicating that the current address is one (of possibly
    126             // many) where execution should be suspended for an entry breakpoint
    127             // of a function.
    128             PrologueEnd:1,
    129             // A boolean indicating that the current address is one (of possibly
    130             // many) where execution should be suspended for an exit breakpoint
    131             // of a function.
    132             EpilogueBegin:1;
    133   };
    134 
    135   // Represents a series of contiguous machine instructions. Line table for each
    136   // compilation unit may consist of multiple sequences, which are not
    137   // guaranteed to be in the order of ascending instruction address.
    138   struct Sequence {
    139     // Sequence describes instructions at address range [LowPC, HighPC)
    140     // and is described by line table rows [FirstRowIndex, LastRowIndex).
    141     uint64_t LowPC;
    142     uint64_t HighPC;
    143     unsigned FirstRowIndex;
    144     unsigned LastRowIndex;
    145     bool Empty;
    146 
    147     Sequence() { reset(); }
    148     void reset() {
    149       LowPC = 0;
    150       HighPC = 0;
    151       FirstRowIndex = 0;
    152       LastRowIndex = 0;
    153       Empty = true;
    154     }
    155     static bool orderByLowPC(const Sequence& LHS, const Sequence& RHS) {
    156       return LHS.LowPC < RHS.LowPC;
    157     }
    158     bool isValid() const {
    159       return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex);
    160     }
    161     bool containsPC(uint64_t pc) const {
    162       return (LowPC <= pc && pc < HighPC);
    163     }
    164   };
    165 
    166   struct LineTable {
    167     void appendRow(const DWARFDebugLine::Row &state) { Rows.push_back(state); }
    168     void appendSequence(const DWARFDebugLine::Sequence &sequence) {
    169       Sequences.push_back(sequence);
    170     }
    171     void clear() {
    172       Prologue.clear();
    173       Rows.clear();
    174       Sequences.clear();
    175     }
    176 
    177     // Returns the index of the row with file/line info for a given address,
    178     // or -1 if there is no such row.
    179     uint32_t lookupAddress(uint64_t address) const;
    180 
    181     bool lookupAddressRange(uint64_t address,
    182                             uint64_t size,
    183                             std::vector<uint32_t>& result) const;
    184 
    185     // Extracts filename by its index in filename table in prologue.
    186     // Returns true on success.
    187     bool getFileNameByIndex(uint64_t FileIndex,
    188                             bool NeedsAbsoluteFilePath,
    189                             std::string &Result) const;
    190 
    191     void dump(raw_ostream &OS) const;
    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   struct State : public Row, public Sequence, public LineTable {
    203     // Special row codes.
    204     enum {
    205       StartParsingLineTable = 0,
    206       DoneParsingLineTable = -1
    207     };
    208 
    209     State() : row(StartParsingLineTable) {}
    210     virtual ~State();
    211 
    212     virtual void appendRowToMatrix(uint32_t offset);
    213     virtual void finalize();
    214     virtual void reset() {
    215       Row::reset(Prologue.DefaultIsStmt);
    216       Sequence::reset();
    217     }
    218 
    219     // The row number that starts at zero for the prologue, and increases for
    220     // each row added to the matrix.
    221     unsigned row;
    222   };
    223 
    224   struct DumpingState : public State {
    225     DumpingState(raw_ostream &OS) : OS(OS) {}
    226     virtual ~DumpingState();
    227     virtual void finalize();
    228   private:
    229     raw_ostream &OS;
    230   };
    231 
    232   static bool parsePrologue(DataExtractor debug_line_data, uint32_t *offset_ptr,
    233                             Prologue *prologue);
    234   /// Parse a single line table (prologue and all rows).
    235   static bool parseStatementTable(DataExtractor debug_line_data,
    236                                   const RelocAddrMap *RMap,
    237                                   uint32_t *offset_ptr, State &state);
    238 
    239   const LineTable *getLineTable(uint32_t offset) const;
    240   const LineTable *getOrParseLineTable(DataExtractor debug_line_data,
    241                                        uint32_t offset);
    242 
    243 private:
    244   typedef std::map<uint32_t, LineTable> LineTableMapTy;
    245   typedef LineTableMapTy::iterator LineTableIter;
    246   typedef LineTableMapTy::const_iterator LineTableConstIter;
    247 
    248   const RelocAddrMap *RelocMap;
    249   LineTableMapTy LineTableMap;
    250 };
    251 
    252 }
    253 
    254 #endif
    255