//===- DWARFDebugLine.h -----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGLINE_H
#define LLVM_DEBUGINFO_DWARF_DWARFDEBUGLINE_H
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/Support/MD5.h"
#include "llvm/Support/Path.h"
#include <cstdint>
#include <map>
#include <string>
#include <vector>
namespace llvm {
class raw_ostream;
class DWARFDebugLine {
public:
struct FileNameEntry {
FileNameEntry() = default;
DWARFFormValue Name;
uint64_t DirIdx = 0;
uint64_t ModTime = 0;
uint64_t Length = 0;
MD5::MD5Result Checksum;
DWARFFormValue Source;
};
/// Tracks which optional content types are present in a DWARF file name
/// entry format.
struct ContentTypeTracker {
ContentTypeTracker() = default;
/// Whether filename entries provide a modification timestamp.
bool HasModTime = false;
/// Whether filename entries provide a file size.
bool HasLength = false;
/// For v5, whether filename entries provide an MD5 checksum.
bool HasMD5 = false;
/// For v5, whether filename entries provide source text.
bool HasSource = false;
/// Update tracked content types with \p ContentType.
void trackContentType(dwarf::LineNumberEntryFormat ContentType);
};
struct Prologue {
Prologue();
/// The size in bytes of the statement information for this compilation unit
/// (not including the total_length field itself).
uint64_t TotalLength;
/// Version, address size (starting in v5), and DWARF32/64 format; these
/// parameters affect interpretation of forms (used in the directory and
/// file tables starting with v5).
dwarf::FormParams FormParams;
/// The number of bytes following the prologue_length field to the beginning
/// of the first byte of the statement program itself.
uint64_t PrologueLength;
/// In v5, size in bytes of a segment selector.
uint8_t SegSelectorSize;
/// 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;
/// This tracks which optional file format content types are present.
ContentTypeTracker ContentTypes;
std::vector<uint8_t> StandardOpcodeLengths;
std::vector<DWARFFormValue> IncludeDirectories;
std::vector<FileNameEntry> FileNames;
const dwarf::FormParams getFormParams() const { return FormParams; }
uint16_t getVersion() const { return FormParams.Version; }
uint8_t getAddressSize() const { return FormParams.AddrSize; }
bool isDWARF64() const { return FormParams.Format == dwarf::DWARF64; }
uint32_t sizeofTotalLength() const { return isDWARF64() ? 12 : 4; }
uint32_t sizeofPrologueLength() const { return isDWARF64() ? 8 : 4; }
bool totalLengthIsValid() const;
/// Length of the prologue in bytes.
uint64_t getLength() const;
/// Get DWARF-version aware access to the file name entry at the provided
/// index.
const llvm::DWARFDebugLine::FileNameEntry &
getFileNameEntry(uint64_t Index) const;
bool hasFileAtIndex(uint64_t FileIndex) const;
std::optional<uint64_t> getLastValidFileIndex() const;
bool
getFileNameByIndex(uint64_t FileIndex, StringRef CompDir,
DILineInfoSpecifier::FileLineInfoKind Kind,
std::string &Result,
sys::path::Style Style = sys::path::Style::native) const;
void clear();
void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const;
Error parse(DWARFDataExtractor Data, uint64_t *OffsetPtr,
function_ref<void(Error)> RecoverableErrorHandler,
const DWARFContext &Ctx, const DWARFUnit *U = nullptr);
};
/// Standard .debug_line state machine structure.
struct Row {
explicit Row(bool DefaultIsStmt = false);
/// Called after a row is appended to the matrix.
void postAppend();
void reset(bool DefaultIsStmt);
void dump(raw_ostream &OS) const;
static void dumpTableHeader(raw_ostream &OS, unsigned Indent);
static bool orderByAddress(const Row &LHS, const Row &RHS) {
return std::tie(LHS.Address.SectionIndex, LHS.Address.Address) <
std::tie(RHS.Address.SectionIndex, RHS.Address.Address);
}
/// The program-counter value corresponding to a machine instruction
/// generated by the compiler and section index pointing to the section
/// containg this PC. If relocation information is present then section
/// index is the index of the section which contains above address.
/// Otherwise this is object::SectionedAddress::Undef value.
object::SectionedAddress 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 representing the DWARF path discriminator value
/// for this location.
uint32_t Discriminator;
/// An unsigned integer whose value encodes the applicable instruction set
/// architecture for the current instruction.
uint8_t Isa;
/// 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.
BasicBlock : 1,
/// A boolean indicating that the current address is that of the
/// first byte after the end of a sequence of target machine
/// instructions.
EndSequence : 1,
/// A boolean indicating that the current address is one (of possibly
/// many) where execution should be suspended for an entry breakpoint
/// of a function.
PrologueEnd : 1,
/// A boolean indicating that the current address is one (of possibly
/// many) where execution should be suspended for an exit breakpoint
/// of a function.
EpilogueBegin : 1;
};
/// 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();
/// Sequence describes instructions at address range [LowPC, HighPC)
/// and is described by line table rows [FirstRowIndex, LastRowIndex).
uint64_t LowPC;
uint64_t HighPC;
/// If relocation information is present then this is the index of the
/// section which contains above addresses. Otherwise this is
/// object::SectionedAddress::Undef value.
uint64_t SectionIndex;
unsigned FirstRowIndex;
unsigned LastRowIndex;
bool Empty;
void reset();
static bool orderByHighPC(const Sequence &LHS, const Sequence &RHS) {
return std::tie(LHS.SectionIndex, LHS.HighPC) <
std::tie(RHS.SectionIndex, RHS.HighPC);
}
bool isValid() const {
return !Empty && (LowPC < HighPC) && (FirstRowIndex < LastRowIndex);
}
bool containsPC(object::SectionedAddress PC) const {
return SectionIndex == PC.SectionIndex &&
(LowPC <= PC.Address && PC.Address < HighPC);
}
};
struct LineTable {
LineTable();
/// Represents an invalid row
const uint32_t UnknownRowIndex = UINT32_MAX;
void appendRow(const DWARFDebugLine::Row &R) { Rows.push_back(R); }
void appendSequence(const DWARFDebugLine::Sequence &S) {
Sequences.push_back(S);
}
/// Returns the index of the row with file/line info for a given address,
/// or UnknownRowIndex if there is no such row.
uint32_t lookupAddress(object::SectionedAddress Address) const;
bool lookupAddressRange(object::SectionedAddress Address, uint64_t Size,
std::vector<uint32_t> &Result) const;
bool hasFileAtIndex(uint64_t FileIndex) const {
return Prologue.hasFileAtIndex(FileIndex);
}
std::optional<uint64_t> getLastValidFileIndex() const {
return Prologue.getLastValidFileIndex();
}
/// Extracts filename by its index in filename table in prologue.
/// In Dwarf 4, the files are 1-indexed and the current compilation file
/// name is not represented in the list. In DWARF v5, the files are
/// 0-indexed and the primary source file has the index 0.
/// Returns true on success.
bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir,
DILineInfoSpecifier::FileLineInfoKind Kind,
std::string &Result) const {
return Prologue.getFileNameByIndex(FileIndex, CompDir, Kind, Result);
}
/// Fills the Result argument with the file and line information
/// corresponding to Address. Returns true on success.
bool getFileLineInfoForAddress(object::SectionedAddress Address,
const char *CompDir,
DILineInfoSpecifier::FileLineInfoKind Kind,
DILineInfo &Result) const;
/// Extracts directory name by its Entry in include directories table
/// in prologue. Returns true on success.
bool getDirectoryForEntry(const FileNameEntry &Entry,
std::string &Directory) const;
void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const;
void clear();
/// Parse prologue and all rows.
Error parse(DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr,
const DWARFContext &Ctx, const DWARFUnit *U,
function_ref<void(Error)> RecoverableErrorHandler,
raw_ostream *OS = nullptr, bool Verbose = false);
using RowVector = std::vector<Row>;
using RowIter = RowVector::const_iterator;
using SequenceVector = std::vector<Sequence>;
using SequenceIter = SequenceVector::const_iterator;
struct Prologue Prologue;
RowVector Rows;
SequenceVector Sequences;
private:
uint32_t findRowInSeq(const DWARFDebugLine::Sequence &Seq,
object::SectionedAddress Address) const;
std::optional<StringRef>
getSourceByIndex(uint64_t FileIndex,
DILineInfoSpecifier::FileLineInfoKind Kind) const;
uint32_t lookupAddressImpl(object::SectionedAddress Address) const;
bool lookupAddressRangeImpl(object::SectionedAddress Address, uint64_t Size,
std::vector<uint32_t> &Result) const;
};
const LineTable *getLineTable(uint64_t Offset) const;
Expected<const LineTable *>
getOrParseLineTable(DWARFDataExtractor &DebugLineData, uint64_t Offset,
const DWARFContext &Ctx, const DWARFUnit *U,
function_ref<void(Error)> RecoverableErrorHandler);
void clearLineTable(uint64_t Offset);
/// Helper to allow for parsing of an entire .debug_line section in sequence.
class SectionParser {
public:
using LineToUnitMap = std::map<uint64_t, DWARFUnit *>;
SectionParser(DWARFDataExtractor &Data, const DWARFContext &C,
DWARFUnitVector::iterator_range Units);
/// Get the next line table from the section. Report any issues via the
/// handlers.
///
/// \param RecoverableErrorHandler - any issues that don't prevent further
/// parsing of the table will be reported through this handler.
/// \param UnrecoverableErrorHandler - any issues that prevent further
/// parsing of the table will be reported through this handler.
/// \param OS - if not null, the parser will print information about the
/// table as it parses it.
/// \param Verbose - if true, the parser will print verbose information when
/// printing to the output.
LineTable parseNext(function_ref<void(Error)> RecoverableErrorHandler,
function_ref<void(Error)> UnrecoverableErrorHandler,
raw_ostream *OS = nullptr, bool Verbose = false);
/// Skip the current line table and go to the following line table (if
/// present) immediately.
///
/// \param RecoverableErrorHandler - report any recoverable prologue
/// parsing issues via this handler.
/// \param UnrecoverableErrorHandler - report any unrecoverable prologue
/// parsing issues via this handler.
void skip(function_ref<void(Error)> RecoverableErrorHandler,
function_ref<void(Error)> UnrecoverableErrorHandler);
/// Indicates if the parser has parsed as much as possible.
///
/// \note Certain problems with the line table structure might mean that
/// parsing stops before the end of the section is reached.
bool done() const { return Done; }
/// Get the offset the parser has reached.
uint64_t getOffset() const { return Offset; }
private:
DWARFUnit *prepareToParse(uint64_t Offset);
void moveToNextTable(uint64_t OldOffset, const Prologue &P);
LineToUnitMap LineToUnit;
DWARFDataExtractor &DebugLineData;
const DWARFContext &Context;
uint64_t Offset = 0;
bool Done = false;
};
private:
struct ParsingState {
ParsingState(struct LineTable *LT, uint64_t TableOffset,
function_ref<void(Error)> ErrorHandler);
void resetRowAndSequence();
void appendRowToMatrix();
/// Advance the address by the \p OperationAdvance value. \returns the
/// amount advanced by.
uint64_t advanceAddr(uint64_t OperationAdvance, uint8_t Opcode,
uint64_t OpcodeOffset);
struct AddrAndAdjustedOpcode {
uint64_t AddrDelta;
uint8_t AdjustedOpcode;
};
/// Advance the address as required by the specified \p Opcode.
/// \returns the amount advanced by and the calculated adjusted opcode.
AddrAndAdjustedOpcode advanceAddrForOpcode(uint8_t Opcode,
uint64_t OpcodeOffset);
struct AddrAndLineDelta {
uint64_t Address;
int32_t Line;
};
/// Advance the line and address as required by the specified special \p
/// Opcode. \returns the address and line delta.
AddrAndLineDelta handleSpecialOpcode(uint8_t Opcode, uint64_t OpcodeOffset);
/// Line table we're currently parsing.
struct LineTable *LineTable;
struct Row Row;
struct Sequence Sequence;
private:
uint64_t LineTableOffset;
bool ReportAdvanceAddrProblem = true;
bool ReportBadLineRange = true;
function_ref<void(Error)> ErrorHandler;
};
using LineTableMapTy = std::map<uint64_t, LineTable>;
using LineTableIter = LineTableMapTy::iterator;
using LineTableConstIter = LineTableMapTy::const_iterator;
LineTableMapTy LineTableMap;
};
} // end namespace llvm
#endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGLINE_H