//===- DWARFContext.h -------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===/

#ifndef LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H
#define LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H

#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
#include "llvm/DebugInfo/DWARF/DWARFObject.h"
#include "llvm/DebugInfo/DWARF/DWARFSection.h"
#include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/Host.h"
#include <cstdint>
#include <deque>
#include <map>
#include <memory>

namespace llvm {

class MCRegisterInfo;
class MemoryBuffer;
class raw_ostream;

/// Used as a return value for a error callback passed to DWARF context.
/// Callback should return Halt if client application wants to stop
/// object parsing, or should return Continue otherwise.
enum class ErrorPolicy { Halt, Continue };

/// DWARFContext
/// This data structure is the top level entity that deals with dwarf debug
/// information parsing. The actual data is supplied through DWARFObj.
class DWARFContext : public DIContext {
  DWARFUnitSection<DWARFCompileUnit> CUs;
  std::deque<DWARFUnitSection<DWARFTypeUnit>> TUs;
  std::unique_ptr<DWARFUnitIndex> CUIndex;
  std::unique_ptr<DWARFGdbIndex> GdbIndex;
  std::unique_ptr<DWARFUnitIndex> TUIndex;
  std::unique_ptr<DWARFDebugAbbrev> Abbrev;
  std::unique_ptr<DWARFDebugLoc> Loc;
  std::unique_ptr<DWARFDebugAranges> Aranges;
  std::unique_ptr<DWARFDebugLine> Line;
  std::unique_ptr<DWARFDebugFrame> DebugFrame;
  std::unique_ptr<DWARFDebugFrame> EHFrame;
  std::unique_ptr<DWARFDebugMacro> Macro;
  std::unique_ptr<DWARFDebugNames> Names;
  std::unique_ptr<AppleAcceleratorTable> AppleNames;
  std::unique_ptr<AppleAcceleratorTable> AppleTypes;
  std::unique_ptr<AppleAcceleratorTable> AppleNamespaces;
  std::unique_ptr<AppleAcceleratorTable> AppleObjC;

  DWARFUnitSection<DWARFCompileUnit> DWOCUs;
  std::deque<DWARFUnitSection<DWARFTypeUnit>> DWOTUs;
  std::unique_ptr<DWARFDebugAbbrev> AbbrevDWO;
  std::unique_ptr<DWARFDebugLocDWO> LocDWO;

  /// The maximum DWARF version of all units.
  unsigned MaxVersion = 0;

  struct DWOFile {
    object::OwningBinary<object::ObjectFile> File;
    std::unique_ptr<DWARFContext> Context;
  };
  StringMap<std::weak_ptr<DWOFile>> DWOFiles;
  std::weak_ptr<DWOFile> DWP;
  bool CheckedForDWP = false;
  std::string DWPName;

  std::unique_ptr<MCRegisterInfo> RegInfo;

  /// Read compile units from the debug_info section (if necessary)
  /// and store them in CUs.
  void parseCompileUnits();

  /// Read type units from the debug_types sections (if necessary)
  /// and store them in TUs.
  void parseTypeUnits();

  /// Read compile units from the debug_info.dwo section (if necessary)
  /// and store them in DWOCUs.
  void parseDWOCompileUnits();

  /// Read type units from the debug_types.dwo section (if necessary)
  /// and store them in DWOTUs.
  void parseDWOTypeUnits();

protected:
  std::unique_ptr<const DWARFObject> DObj;

public:
  DWARFContext(std::unique_ptr<const DWARFObject> DObj,
               std::string DWPName = "");
  ~DWARFContext();

  DWARFContext(DWARFContext &) = delete;
  DWARFContext &operator=(DWARFContext &) = delete;

  const DWARFObject &getDWARFObj() const { return *DObj; }

  static bool classof(const DIContext *DICtx) {
    return DICtx->getKind() == CK_DWARF;
  }

  /// Dump a textual representation to \p OS. If any \p DumpOffsets are present,
  /// dump only the record at the specified offset.
  void dump(raw_ostream &OS, DIDumpOptions DumpOpts,
            std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets);

  void dump(raw_ostream &OS, DIDumpOptions DumpOpts) override {
    std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets;
    dump(OS, DumpOpts, DumpOffsets);
  }

  bool verify(raw_ostream &OS, DIDumpOptions DumpOpts = {}) override;

  using cu_iterator_range = DWARFUnitSection<DWARFCompileUnit>::iterator_range;
  using tu_iterator_range = DWARFUnitSection<DWARFTypeUnit>::iterator_range;
  using tu_section_iterator_range = iterator_range<decltype(TUs)::iterator>;

  /// Get compile units in this context.
  cu_iterator_range compile_units() {
    parseCompileUnits();
    return cu_iterator_range(CUs.begin(), CUs.end());
  }

  /// Get type units in this context.
  tu_section_iterator_range type_unit_sections() {
    parseTypeUnits();
    return tu_section_iterator_range(TUs.begin(), TUs.end());
  }

  /// Get compile units in the DWO context.
  cu_iterator_range dwo_compile_units() {
    parseDWOCompileUnits();
    return cu_iterator_range(DWOCUs.begin(), DWOCUs.end());
  }

  /// Get type units in the DWO context.
  tu_section_iterator_range dwo_type_unit_sections() {
    parseDWOTypeUnits();
    return tu_section_iterator_range(DWOTUs.begin(), DWOTUs.end());
  }

  /// Get the number of compile units in this context.
  unsigned getNumCompileUnits() {
    parseCompileUnits();
    return CUs.size();
  }

  /// Get the number of compile units in this context.
  unsigned getNumTypeUnits() {
    parseTypeUnits();
    return TUs.size();
  }

  /// Get the number of compile units in the DWO context.
  unsigned getNumDWOCompileUnits() {
    parseDWOCompileUnits();
    return DWOCUs.size();
  }

  /// Get the number of compile units in the DWO context.
  unsigned getNumDWOTypeUnits() {
    parseDWOTypeUnits();
    return DWOTUs.size();
  }

  /// Get the compile unit at the specified index for this compile unit.
  DWARFCompileUnit *getCompileUnitAtIndex(unsigned index) {
    parseCompileUnits();
    return CUs[index].get();
  }

  /// Get the compile unit at the specified index for the DWO compile units.
  DWARFCompileUnit *getDWOCompileUnitAtIndex(unsigned index) {
    parseDWOCompileUnits();
    return DWOCUs[index].get();
  }

  DWARFCompileUnit *getDWOCompileUnitForHash(uint64_t Hash);

  /// Get a DIE given an exact offset.
  DWARFDie getDIEForOffset(uint32_t Offset);

  unsigned getMaxVersion() const { return MaxVersion; }

  void setMaxVersionIfGreater(unsigned Version) {
    if (Version > MaxVersion)
      MaxVersion = Version;
  }

  const DWARFUnitIndex &getCUIndex();
  DWARFGdbIndex &getGdbIndex();
  const DWARFUnitIndex &getTUIndex();

  /// Get a pointer to the parsed DebugAbbrev object.
  const DWARFDebugAbbrev *getDebugAbbrev();

  /// Get a pointer to the parsed DebugLoc object.
  const DWARFDebugLoc *getDebugLoc();

  /// Get a pointer to the parsed dwo abbreviations object.
  const DWARFDebugAbbrev *getDebugAbbrevDWO();

  /// Get a pointer to the parsed DebugLoc object.
  const DWARFDebugLocDWO *getDebugLocDWO();

  /// Get a pointer to the parsed DebugAranges object.
  const DWARFDebugAranges *getDebugAranges();

  /// Get a pointer to the parsed frame information object.
  const DWARFDebugFrame *getDebugFrame();

  /// Get a pointer to the parsed eh frame information object.
  const DWARFDebugFrame *getEHFrame();

  /// Get a pointer to the parsed DebugMacro object.
  const DWARFDebugMacro *getDebugMacro();

  /// Get a reference to the parsed accelerator table object.
  const DWARFDebugNames &getDebugNames();

  /// Get a reference to the parsed accelerator table object.
  const AppleAcceleratorTable &getAppleNames();

  /// Get a reference to the parsed accelerator table object.
  const AppleAcceleratorTable &getAppleTypes();

  /// Get a reference to the parsed accelerator table object.
  const AppleAcceleratorTable &getAppleNamespaces();

  /// Get a reference to the parsed accelerator table object.
  const AppleAcceleratorTable &getAppleObjC();

  /// Get a pointer to a parsed line table corresponding to a compile unit.
  const DWARFDebugLine::LineTable *getLineTableForUnit(DWARFUnit *cu);

  DataExtractor getStringExtractor() const {
    return DataExtractor(DObj->getStringSection(), false, 0);
  }
  DataExtractor getLineStringExtractor() const {
    return DataExtractor(DObj->getLineStringSection(), false, 0);
  }

  /// Wraps the returned DIEs for a given address.
  struct DIEsForAddress {
    DWARFCompileUnit *CompileUnit = nullptr;
    DWARFDie FunctionDIE;
    DWARFDie BlockDIE;
    explicit operator bool() const { return CompileUnit != nullptr; }
  };

  /// Get the compilation unit, the function DIE and lexical block DIE for the
  /// given address where applicable.
  DIEsForAddress getDIEsForAddress(uint64_t Address);

  DILineInfo getLineInfoForAddress(uint64_t Address,
      DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
  DILineInfoTable getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
      DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
  DIInliningInfo getInliningInfoForAddress(uint64_t Address,
      DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;

  bool isLittleEndian() const { return DObj->isLittleEndian(); }
  static bool isSupportedVersion(unsigned version) {
    return version == 2 || version == 3 || version == 4 || version == 5;
  }

  std::shared_ptr<DWARFContext> getDWOContext(StringRef AbsolutePath);

  const MCRegisterInfo *getRegisterInfo() const { return RegInfo.get(); }

  /// Function used to handle default error reporting policy. Prints a error
  /// message and returns Continue, so DWARF context ignores the error.
  static ErrorPolicy defaultErrorHandler(Error E);
  static std::unique_ptr<DWARFContext>
  create(const object::ObjectFile &Obj, const LoadedObjectInfo *L = nullptr,
         function_ref<ErrorPolicy(Error)> HandleError = defaultErrorHandler,
         std::string DWPName = "");

  static std::unique_ptr<DWARFContext>
  create(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
         uint8_t AddrSize, bool isLittleEndian = sys::IsLittleEndianHost);

  /// Loads register info for the architecture of the provided object file.
  /// Improves readability of dumped DWARF expressions. Requires the caller to
  /// have initialized the relevant target descriptions.
  Error loadRegisterInfo(const object::ObjectFile &Obj);

private:
  /// Return the compile unit that includes an offset (relative to .debug_info).
  DWARFCompileUnit *getCompileUnitForOffset(uint32_t Offset);

  /// Return the compile unit which contains instruction with provided
  /// address.
  DWARFCompileUnit *getCompileUnitForAddress(uint64_t Address);
};

} // end namespace llvm

#endif // LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H