llvm-project/llvm/tools/dsymutil/DwarfStreamer.h

//===- tools/dsymutil/DwarfStreamer.h - Dwarf Streamer ----------*- 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_TOOLS_DSYMUTIL_DWARFSTREAMER_H
#define LLVM_TOOLS_DSYMUTIL_DWARFSTREAMER_H

#include "CompileUnit.h"
#include "DebugMap.h"
#include "LinkUtils.h"
#include "NonRelocatableStringpool.h"
#include "llvm/CodeGen/AccelTable.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"

namespace llvm {
namespace dsymutil {

/// The Dwarf streaming logic.
///
/// All interactions with the MC layer that is used to build the debug
/// information binary representation are handled in this class.
class DwarfStreamer {
public:
  DwarfStreamer(raw_fd_ostream &OutFile, LinkOptions Options)
      : OutFile(OutFile), Options(std::move(Options)) {}

  bool init(Triple TheTriple);

  /// Dump the file to the disk.
  bool finish(const DebugMap &, SymbolMapTranslator &T);

  AsmPrinter &getAsmPrinter() const { return *Asm; }

  /// Set the current output section to debug_info and change
  /// the MC Dwarf version to \p DwarfVersion.
  void switchToDebugInfoSection(unsigned DwarfVersion);

  /// Emit the compilation unit header for \p Unit in the
  /// debug_info section.
  ///
  /// As a side effect, this also switches the current Dwarf version
  /// of the MC layer to the one of U.getOrigUnit().
  void emitCompileUnitHeader(CompileUnit &Unit);

  /// Recursively emit the DIE tree rooted at \p Die.
  void emitDIE(DIE &Die);

  /// Emit the abbreviation table \p Abbrevs to the debug_abbrev section.
  void emitAbbrevs(const std::vector<std::unique_ptr<DIEAbbrev>> &Abbrevs,
                   unsigned DwarfVersion);

  /// Emit the string table described by \p Pool.
  void emitStrings(const NonRelocatableStringpool &Pool);

  /// Emit the swift_ast section stored in \p Buffer.
  void emitSwiftAST(StringRef Buffer);

  /// Emit debug_ranges for \p FuncRange by translating the
  /// original \p Entries.
  void emitRangesEntries(
      int64_t UnitPcOffset, uint64_t OrigLowPc,
      const FunctionIntervals::const_iterator &FuncRange,
      const std::vector<DWARFDebugRangeList::RangeListEntry> &Entries,
      unsigned AddressSize);

  /// Emit debug_aranges entries for \p Unit and if \p DoRangesSection is true,
  /// also emit the debug_ranges entries for the DW_TAG_compile_unit's
  /// DW_AT_ranges attribute.
  void emitUnitRangesEntries(CompileUnit &Unit, bool DoRangesSection);

  uint32_t getRangesSectionSize() const { return RangesSectionSize; }

  /// Emit the debug_loc contribution for \p Unit by copying the entries from
  /// \p Dwarf and offsetting them. Update the location attributes to point to
  /// the new entries.
  void emitLocationsForUnit(
      const CompileUnit &Unit, DWARFContext &Dwarf,
      std::function<void(StringRef, SmallVectorImpl<uint8_t> &)> ProcessExpr);

  /// Emit the line table described in \p Rows into the debug_line section.
  void emitLineTableForUnit(MCDwarfLineTableParams Params,
                            StringRef PrologueBytes, unsigned MinInstLength,
                            std::vector<DWARFDebugLine::Row> &Rows,
                            unsigned AdddressSize);

  /// Copy the debug_line over to the updated binary while unobfuscating the
  /// file names and directories.
  void translateLineTable(DataExtractor LineData, uint32_t Offset);

  /// Copy over the debug sections that are not modified when updating.
  void copyInvariantDebugSection(const object::ObjectFile &Obj);

  uint32_t getLineSectionSize() const { return LineSectionSize; }

  /// Emit the .debug_pubnames contribution for \p Unit.
  void emitPubNamesForUnit(const CompileUnit &Unit);

  /// Emit the .debug_pubtypes contribution for \p Unit.
  void emitPubTypesForUnit(const CompileUnit &Unit);

  /// Emit a CIE.
  void emitCIE(StringRef CIEBytes);

  /// Emit an FDE with data \p Bytes.
  void emitFDE(uint32_t CIEOffset, uint32_t AddreSize, uint32_t Address,
               StringRef Bytes);

  /// Emit DWARF debug names.
  void emitDebugNames(AccelTable<DWARF5AccelTableStaticData> &Table);

  /// Emit Apple namespaces accelerator table.
  void emitAppleNamespaces(AccelTable<AppleAccelTableStaticOffsetData> &Table);

  /// Emit Apple names accelerator table.
  void emitAppleNames(AccelTable<AppleAccelTableStaticOffsetData> &Table);

  /// Emit Apple Objective-C accelerator table.
  void emitAppleObjc(AccelTable<AppleAccelTableStaticOffsetData> &Table);

  /// Emit Apple type accelerator table.
  void emitAppleTypes(AccelTable<AppleAccelTableStaticTypeData> &Table);

  uint32_t getFrameSectionSize() const { return FrameSectionSize; }

private:
  /// \defgroup MCObjects MC layer objects constructed by the streamer
  /// @{
  std::unique_ptr<MCRegisterInfo> MRI;
  std::unique_ptr<MCAsmInfo> MAI;
  std::unique_ptr<MCObjectFileInfo> MOFI;
  std::unique_ptr<MCContext> MC;
  MCAsmBackend *MAB; // Owned by MCStreamer
  std::unique_ptr<MCInstrInfo> MII;
  std::unique_ptr<MCSubtargetInfo> MSTI;
  MCInstPrinter *MIP; // Owned by AsmPrinter
  MCCodeEmitter *MCE; // Owned by MCStreamer
  MCStreamer *MS;     // Owned by AsmPrinter
  std::unique_ptr<TargetMachine> TM;
  std::unique_ptr<AsmPrinter> Asm;
  /// @}

  /// The file we stream the linked Dwarf to.
  raw_fd_ostream &OutFile;

  LinkOptions Options;

  uint32_t RangesSectionSize;
  uint32_t LocSectionSize;
  uint32_t LineSectionSize;
  uint32_t FrameSectionSize;

  /// Keep track of emitted CUs and their Unique ID.
  struct EmittedUnit {
    unsigned ID;
    MCSymbol *LabelBegin;
  };
  std::vector<EmittedUnit> EmittedUnits;

  /// Emit the pubnames or pubtypes section contribution for \p
  /// Unit into \p Sec. The data is provided in \p Names.
  void emitPubSectionForUnit(MCSection *Sec, StringRef Name,
                             const CompileUnit &Unit,
                             const std::vector<CompileUnit::AccelInfo> &Names);
};

} // end namespace dsymutil
} // end namespace llvm

#endif // LLVM_TOOLS_DSYMUTIL_DWARFSTREAMER_H