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
19namespace llvm {
20
21class raw_ostream;
22
23class DWARFDebugLine {
24public:
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
243private:
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