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//===-- DWARFDebugLine.h ----------------------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
#include "DWARFRelocMap.h"
#include "llvm/Support/DataExtractor.h"
#include <map>
#include <string>
#include <vector>
namespace llvm {
class raw_ostream;
class DWARFDebugLine {
DWARFDebugLine(const RelocAddrMap* LineInfoRelocMap) : RelocMap(LineInfoRelocMap) {}
struct FileNameEntry {
FileNameEntry() : Name(nullptr), DirIdx(0), ModTime(0), Length(0) {}
const char *Name;
uint64_t DirIdx;
uint64_t ModTime;
uint64_t Length;
struct Prologue {
// The size in bytes of the statement information for this compilation unit
// (not including the total_length field itself).
uint32_t TotalLength;
// Version identifier for the statement information format.
uint16_t Version;
// The number of bytes following the prologue_length field to the beginning
// of the first byte of the statement program itself.
uint32_t PrologueLength;
// The size in bytes of the smallest target machine instruction. Statement
// program opcodes that alter the address register first multiply their
// operands by this value.
uint8_t MinInstLength;
// The maximum number of individual operations that may be encoded in an
// instruction.
uint8_t MaxOpsPerInst;
// The initial value of theis_stmtregister.
uint8_t DefaultIsStmt;
// This parameter affects the meaning of the special opcodes. See below.
int8_t LineBase;
// This parameter affects the meaning of the special opcodes. See below.
uint8_t LineRange;
// The number assigned to the first special opcode.
uint8_t OpcodeBase;
std::vector<uint8_t> StandardOpcodeLengths;
std::vector<const char*> IncludeDirectories;
std::vector<FileNameEntry> FileNames;
// Length of the prologue in bytes.
uint32_t getLength() const {
return PrologueLength + sizeof(TotalLength) + sizeof(Version) +
// Length of the line table data in bytes (not including the prologue).
uint32_t getStatementTableLength() const {
return TotalLength + sizeof(TotalLength) - getLength();
int32_t getMaxLineIncrementForSpecialOpcode() const {
return LineBase + (int8_t)LineRange - 1;
void clear();
void dump(raw_ostream &OS) const;
bool parse(DataExtractor debug_line_data, uint32_t *offset_ptr);
// Standard .debug_line state machine structure.
struct Row {
explicit Row(bool default_is_stmt = false);
/// Called after a row is appended to the matrix.
void postAppend();
void reset(bool default_is_stmt);
void dump(raw_ostream &OS) const;
static bool orderByAddress(const Row& LHS, const Row& RHS) {
return LHS.Address < RHS.Address;
// The program-counter value corresponding to a machine instruction
// generated by the compiler.
uint64_t Address;
// An unsigned integer indicating a source line number. Lines are numbered
// beginning at 1. The compiler may emit the value 0 in cases where an
// instruction cannot be attributed to any source line.
uint32_t Line;
// An unsigned integer indicating a column number within a source line.
// Columns are numbered beginning at 1. The value 0 is reserved to indicate
// that a statement begins at the 'left edge' of the line.
uint16_t Column;
// An unsigned integer indicating the identity of the source file
// corresponding to a machine instruction.
uint16_t File;
// An unsigned integer whose value encodes the applicable instruction set
// architecture for the current instruction.
uint8_t Isa;
// An unsigned integer representing the DWARF path discriminator value
// for this location.
uint32_t Discriminator;
// A boolean indicating that the current instruction is the beginning of a
// statement.
uint8_t IsStmt:1,
// A boolean indicating that the current instruction is the
// beginning of a basic block.
// A boolean indicating that the current address is that of the
// first byte after the end of a sequence of target machine
// instructions.
// A boolean indicating that the current address is one (of possibly
// many) where execution should be suspended for an entry breakpoint
// of a function.
// A boolean indicating that the current address is one (of possibly
// many) where execution should be suspended for an exit breakpoint
// of a function.
// Represents a series of contiguous machine instructions. Line table for each
// compilation unit may consist of multiple sequences, which are not
// guaranteed to be in the order of ascending instruction address.
struct Sequence {
// Sequence describes instructions at address range [LowPC, HighPC)
// and is described by line table rows [FirstRowIndex, LastRowIndex).
uint64_t LowPC;
uint64_t HighPC;
unsigned FirstRowIndex;
unsigned LastRowIndex;
bool Empty;
void reset();
static bool orderByLowPC(const Sequence& LHS, const Sequence& RHS) {
return LHS.LowPC < RHS.LowPC;
bool isValid() const {
return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex);
bool containsPC(uint64_t pc) const {
return (LowPC <= pc && pc < HighPC);
struct LineTable {
void appendRow(const DWARFDebugLine::Row &R) {
void appendSequence(const DWARFDebugLine::Sequence &S) {
// Returns the index of the row with file/line info for a given address,
// or -1 if there is no such row.
uint32_t lookupAddress(uint64_t address) const;
bool lookupAddressRange(uint64_t address, uint64_t size,
std::vector<uint32_t> &result) const;
// Extracts filename by its index in filename table in prologue.
// Returns true on success.
bool getFileNameByIndex(uint64_t FileIndex,
bool NeedsAbsoluteFilePath,
std::string &Result) const;
void dump(raw_ostream &OS) const;
void clear();
/// Parse prologue and all rows.
bool parse(DataExtractor debug_line_data, const RelocAddrMap *RMap,
uint32_t *offset_ptr);
struct Prologue Prologue;
typedef std::vector<Row> RowVector;
typedef RowVector::const_iterator RowIter;
typedef std::vector<Sequence> SequenceVector;
typedef SequenceVector::const_iterator SequenceIter;
RowVector Rows;
SequenceVector Sequences;
const LineTable *getLineTable(uint32_t offset) const;
const LineTable *getOrParseLineTable(DataExtractor debug_line_data,
uint32_t offset);
struct ParsingState {
ParsingState(struct LineTable *LT);
void resetRowAndSequence();
void appendRowToMatrix(uint32_t offset);
// Line table we're currently parsing.
struct LineTable *LineTable;
// The row number that starts at zero for the prologue, and increases for
// each row added to the matrix.
unsigned RowNumber;
struct Row Row;
struct Sequence Sequence;
typedef std::map<uint32_t, LineTable> LineTableMapTy;
typedef LineTableMapTy::iterator LineTableIter;
typedef LineTableMapTy::const_iterator LineTableConstIter;
const RelocAddrMap *RelocMap;
LineTableMapTy LineTableMap;