YQ Connector: support managed ClickHouse

Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.

1 files changed, 836 insertions, 0 deletions

diff --git a/contrib/libs/llvm14/include/llvm/DWARFLinker/DWARFLinker.h b/contrib/libs/llvm14/include/llvm/DWARFLinker/DWARFLinker.h
new file mode 100644
index 0000000000..6641641573
--- /dev/null
+++ b/contrib/libs/llvm14/include/llvm/DWARFLinker/DWARFLinker.h
@@ -0,0 +1,836 @@
+#pragma once
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
+
+//===- DWARFLinker.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_DWARFLINKER_DWARFLINKER_H
+#define LLVM_DWARFLINKER_DWARFLINKER_H
+
+#include "llvm/CodeGen/AccelTable.h"
+#include "llvm/CodeGen/NonRelocatableStringpool.h"
+#include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/MC/MCDwarf.h"
+#include <map>
+
+namespace llvm {
+
+enum class DwarfLinkerClient { Dsymutil, LLD, General };
+
+/// The kind of accelerator tables we should emit.
+enum class AccelTableKind {
+  Apple,   ///< .apple_names, .apple_namespaces, .apple_types, .apple_objc.
+  Dwarf,   ///< DWARF v5 .debug_names.
+  Default, ///< Dwarf for DWARF5 or later, Apple otherwise.
+  Pub,     ///< .debug_pubnames, .debug_pubtypes
+};
+
+/// Partial address range. Besides an offset, only the
+/// HighPC is stored. The structure is stored in a map where the LowPC is the
+/// key.
+struct ObjFileAddressRange {
+  /// Function HighPC.
+  uint64_t HighPC;
+  /// Offset to apply to the linked address.
+  /// should be 0 for not-linked object file.
+  int64_t Offset;
+
+  ObjFileAddressRange(uint64_t EndPC, int64_t Offset)
+      : HighPC(EndPC), Offset(Offset) {}
+
+  ObjFileAddressRange() : HighPC(0), Offset(0) {}
+};
+
+/// Map LowPC to ObjFileAddressRange.
+using RangesTy = std::map<uint64_t, ObjFileAddressRange>;
+
+/// AddressesMap represents information about valid addresses used
+/// by debug information. Valid addresses are those which points to
+/// live code sections. i.e. relocations for these addresses point
+/// into sections which would be/are placed into resulting binary.
+class AddressesMap {
+public:
+  virtual ~AddressesMap();
+
+  /// Returns true if represented addresses are from linked file.
+  /// Returns false if represented addresses are from not-linked
+  /// object file.
+  virtual bool areRelocationsResolved() const = 0;
+
+  /// Checks that there are valid relocations against a .debug_info
+  /// section.
+  virtual bool hasValidRelocs() = 0;
+
+  /// Checks that the specified DIE has a DW_AT_Location attribute
+  /// that references into a live code section.
+  ///
+  /// \returns true and sets Info.InDebugMap if it is the case.
+  virtual bool hasLiveMemoryLocation(const DWARFDie &DIE,
+                                     CompileUnit::DIEInfo &Info) = 0;
+
+  /// Checks that the specified DIE has a DW_AT_Low_pc attribute
+  /// that references into a live code section.
+  ///
+  /// \returns true and sets Info.InDebugMap if it is the case.
+  virtual bool hasLiveAddressRange(const DWARFDie &DIE,
+                                   CompileUnit::DIEInfo &Info) = 0;
+
+  /// Apply the valid relocations to the buffer \p Data, taking into
+  /// account that Data is at \p BaseOffset in the .debug_info section.
+  ///
+  /// \returns true whether any reloc has been applied.
+  virtual bool applyValidRelocs(MutableArrayRef<char> Data, uint64_t BaseOffset,
+                                bool IsLittleEndian) = 0;
+
+  /// Relocate the given address offset if a valid relocation exists.
+  virtual llvm::Expected<uint64_t> relocateIndexedAddr(uint64_t StartOffset,
+                                                       uint64_t EndOffset) = 0;
+
+  /// Returns all valid functions address ranges(i.e., those ranges
+  /// which points to sections with code).
+  virtual RangesTy &getValidAddressRanges() = 0;
+
+  /// Erases all data.
+  virtual void clear() = 0;
+};
+
+/// DwarfEmitter presents interface to generate all debug info tables.
+class DwarfEmitter {
+public:
+  virtual ~DwarfEmitter();
+
+  /// Emit DIE containing warnings.
+  virtual void emitPaperTrailWarningsDie(DIE &Die) = 0;
+
+  /// Emit section named SecName with data SecData.
+  virtual void emitSectionContents(StringRef SecData, StringRef SecName) = 0;
+
+  /// Emit the abbreviation table \p Abbrevs to the .debug_abbrev section.
+  virtual void
+  emitAbbrevs(const std::vector<std::unique_ptr<DIEAbbrev>> &Abbrevs,
+              unsigned DwarfVersion) = 0;
+
+  /// Emit the string table described by \p Pool.
+  virtual void emitStrings(const NonRelocatableStringpool &Pool) = 0;
+
+  /// Emit DWARF debug names.
+  virtual void
+  emitDebugNames(AccelTable<DWARF5AccelTableStaticData> &Table) = 0;
+
+  /// Emit Apple namespaces accelerator table.
+  virtual void
+  emitAppleNamespaces(AccelTable<AppleAccelTableStaticOffsetData> &Table) = 0;
+
+  /// Emit Apple names accelerator table.
+  virtual void
+  emitAppleNames(AccelTable<AppleAccelTableStaticOffsetData> &Table) = 0;
+
+  /// Emit Apple Objective-C accelerator table.
+  virtual void
+  emitAppleObjc(AccelTable<AppleAccelTableStaticOffsetData> &Table) = 0;
+
+  /// Emit Apple type accelerator table.
+  virtual void
+  emitAppleTypes(AccelTable<AppleAccelTableStaticTypeData> &Table) = 0;
+
+  /// Emit .debug_ranges for \p FuncRange by translating the
+  /// original \p Entries.
+  virtual void emitRangesEntries(
+      int64_t UnitPcOffset, uint64_t OrigLowPc,
+      const FunctionIntervals::const_iterator &FuncRange,
+      const std::vector<DWARFDebugRangeList::RangeListEntry> &Entries,
+      unsigned AddressSize) = 0;
+
+  /// 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.
+  virtual void emitUnitRangesEntries(CompileUnit &Unit,
+                                     bool DoRangesSection) = 0;
+
+  /// Copy the .debug_line over to the updated binary while unobfuscating the
+  /// file names and directories.
+  virtual void translateLineTable(DataExtractor LineData, uint64_t Offset) = 0;
+
+  /// Emit the line table described in \p Rows into the .debug_line section.
+  virtual void emitLineTableForUnit(MCDwarfLineTableParams Params,
+                                    StringRef PrologueBytes,
+                                    unsigned MinInstLength,
+                                    std::vector<DWARFDebugLine::Row> &Rows,
+                                    unsigned AdddressSize) = 0;
+
+  /// Emit the .debug_pubnames contribution for \p Unit.
+  virtual void emitPubNamesForUnit(const CompileUnit &Unit) = 0;
+
+  /// Emit the .debug_pubtypes contribution for \p Unit.
+  virtual void emitPubTypesForUnit(const CompileUnit &Unit) = 0;
+
+  /// Emit a CIE.
+  virtual void emitCIE(StringRef CIEBytes) = 0;
+
+  /// Emit an FDE with data \p Bytes.
+  virtual void emitFDE(uint32_t CIEOffset, uint32_t AddreSize, uint32_t Address,
+                       StringRef Bytes) = 0;
+
+  /// 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.
+  virtual void emitLocationsForUnit(
+      const CompileUnit &Unit, DWARFContext &Dwarf,
+      std::function<void(StringRef, SmallVectorImpl<uint8_t> &)>
+          ProcessExpr) = 0;
+
+  /// 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().
+  virtual void emitCompileUnitHeader(CompileUnit &Unit,
+                                     unsigned DwarfVersion) = 0;
+
+  /// Recursively emit the DIE tree rooted at \p Die.
+  virtual void emitDIE(DIE &Die) = 0;
+
+  /// Returns size of generated .debug_line section.
+  virtual uint64_t getLineSectionSize() const = 0;
+
+  /// Returns size of generated .debug_frame section.
+  virtual uint64_t getFrameSectionSize() const = 0;
+
+  /// Returns size of generated .debug_ranges section.
+  virtual uint64_t getRangesSectionSize() const = 0;
+
+  /// Returns size of generated .debug_info section.
+  virtual uint64_t getDebugInfoSectionSize() const = 0;
+};
+
+using UnitListTy = std::vector<std::unique_ptr<CompileUnit>>;
+
+/// this class represents DWARF information for source file
+/// and it`s address map.
+class DWARFFile {
+public:
+  DWARFFile(StringRef Name, DWARFContext *Dwarf, AddressesMap *Addresses,
+            const std::vector<std::string> &Warnings)
+      : FileName(Name), Dwarf(Dwarf), Addresses(Addresses), Warnings(Warnings) {
+  }
+
+  /// object file name.
+  StringRef FileName;
+  /// source DWARF information.
+  DWARFContext *Dwarf = nullptr;
+  /// helpful address information(list of valid address ranges, relocations).
+  AddressesMap *Addresses = nullptr;
+  /// warnings for object file.
+  const std::vector<std::string> &Warnings;
+};
+
+typedef std::function<void(const Twine &Warning, StringRef Context,
+                           const DWARFDie *DIE)>
+    messageHandler;
+typedef std::function<ErrorOr<DWARFFile &>(StringRef ContainerName,
+                                           StringRef Path)>
+    objFileLoader;
+typedef std::map<std::string, std::string> swiftInterfacesMap;
+typedef std::map<std::string, std::string> objectPrefixMap;
+
+/// The core of the Dwarf linking logic.
+///
+/// The generation of the dwarf information from the object files will be
+/// driven by the selection of 'root DIEs', which are DIEs that
+/// describe variables or functions that resolves to the corresponding
+/// code section(and thus have entries in the Addresses map). All the debug
+/// information that will be generated(the DIEs, but also the line
+/// tables, ranges, ...) is derived from that set of root DIEs.
+///
+/// The root DIEs are identified because they contain relocations that
+/// points to code section(the low_pc for a function, the location for
+/// a variable). These relocations are called ValidRelocs in the
+/// AddressesInfo and are gathered as a very first step when we start
+/// processing a object file.
+class DWARFLinker {
+public:
+  DWARFLinker(DwarfEmitter *Emitter,
+              DwarfLinkerClient ClientID = DwarfLinkerClient::General)
+      : TheDwarfEmitter(Emitter), DwarfLinkerClientID(ClientID) {}
+
+  /// Add object file to be linked.
+  void addObjectFile(DWARFFile &File);
+
+  /// Link debug info for added objFiles. Object
+  /// files are linked all together.
+  bool link();
+
+  /// A number of methods setting various linking options:
+
+  /// Allows to generate log of linking process to the standard output.
+  void setVerbosity(bool Verbose) { Options.Verbose = Verbose; }
+
+  /// Print statistics to standard output.
+  void setStatistics(bool Statistics) { Options.Statistics = Statistics; }
+
+  /// Do not emit linked dwarf info.
+  void setNoOutput(bool NoOut) { Options.NoOutput = NoOut; }
+
+  /// Do not unique types according to ODR.
+  void setNoODR(bool NoODR) { Options.NoODR = NoODR; }
+
+  /// update existing DWARF info(for the linked binary).
+  void setUpdate(bool Update) { Options.Update = Update; }
+
+  /// Set whether to keep the enclosing function for a static variable.
+  void setKeepFunctionForStatic(bool KeepFunctionForStatic) {
+    Options.KeepFunctionForStatic = KeepFunctionForStatic;
+  }
+
+  /// Use specified number of threads for parallel files linking.
+  void setNumThreads(unsigned NumThreads) { Options.Threads = NumThreads; }
+
+  /// Set kind of accelerator tables to be generated.
+  void setAccelTableKind(AccelTableKind Kind) {
+    Options.TheAccelTableKind = Kind;
+  }
+
+  /// Set prepend path for clang modules.
+  void setPrependPath(const std::string &Ppath) { Options.PrependPath = Ppath; }
+
+  /// Set translator which would be used for strings.
+  void
+  setStringsTranslator(std::function<StringRef(StringRef)> StringsTranslator) {
+    this->StringsTranslator = StringsTranslator;
+  }
+
+  /// Set estimated objects files amount, for preliminary data allocation.
+  void setEstimatedObjfilesAmount(unsigned ObjFilesNum) {
+    ObjectContexts.reserve(ObjFilesNum);
+  }
+
+  /// Set warning handler which would be used to report warnings.
+  void setWarningHandler(messageHandler Handler) {
+    Options.WarningHandler = Handler;
+  }
+
+  /// Set error handler which would be used to report errors.
+  void setErrorHandler(messageHandler Handler) {
+    Options.ErrorHandler = Handler;
+  }
+
+  /// Set object files loader which would be used to load
+  /// additional objects for splitted dwarf.
+  void setObjFileLoader(objFileLoader Loader) {
+    Options.ObjFileLoader = Loader;
+  }
+
+  /// Set map for Swift interfaces.
+  void setSwiftInterfacesMap(swiftInterfacesMap *Map) {
+    Options.ParseableSwiftInterfaces = Map;
+  }
+
+  /// Set prefix map for objects.
+  void setObjectPrefixMap(objectPrefixMap *Map) {
+    Options.ObjectPrefixMap = Map;
+  }
+
+private:
+  /// Flags passed to DwarfLinker::lookForDIEsToKeep
+  enum TraversalFlags {
+    TF_Keep = 1 << 0,            ///< Mark the traversed DIEs as kept.
+    TF_InFunctionScope = 1 << 1, ///< Current scope is a function scope.
+    TF_DependencyWalk = 1 << 2,  ///< Walking the dependencies of a kept DIE.
+    TF_ParentWalk = 1 << 3,      ///< Walking up the parents of a kept DIE.
+    TF_ODR = 1 << 4,             ///< Use the ODR while keeping dependents.
+    TF_SkipPC = 1 << 5,          ///< Skip all location attributes.
+  };
+
+  /// The  distinct types of work performed by the work loop.
+  enum class WorklistItemType {
+    /// Given a DIE, look for DIEs to be kept.
+    LookForDIEsToKeep,
+    /// Given a DIE, look for children of this DIE to be kept.
+    LookForChildDIEsToKeep,
+    /// Given a DIE, look for DIEs referencing this DIE to be kept.
+    LookForRefDIEsToKeep,
+    /// Given a DIE, look for parent DIEs to be kept.
+    LookForParentDIEsToKeep,
+    /// Given a DIE, update its incompleteness based on whether its children are
+    /// incomplete.
+    UpdateChildIncompleteness,
+    /// Given a DIE, update its incompleteness based on whether the DIEs it
+    /// references are incomplete.
+    UpdateRefIncompleteness,
+  };
+
+  /// This class represents an item in the work list. The type defines what kind
+  /// of work needs to be performed when processing the current item. The flags
+  /// and info fields are optional based on the type.
+  struct WorklistItem {
+    DWARFDie Die;
+    WorklistItemType Type;
+    CompileUnit &CU;
+    unsigned Flags;
+    union {
+      const unsigned AncestorIdx;
+      CompileUnit::DIEInfo *OtherInfo;
+    };
+
+    WorklistItem(DWARFDie Die, CompileUnit &CU, unsigned Flags,
+                 WorklistItemType T = WorklistItemType::LookForDIEsToKeep)
+        : Die(Die), Type(T), CU(CU), Flags(Flags), AncestorIdx(0) {}
+
+    WorklistItem(DWARFDie Die, CompileUnit &CU, WorklistItemType T,
+                 CompileUnit::DIEInfo *OtherInfo = nullptr)
+        : Die(Die), Type(T), CU(CU), Flags(0), OtherInfo(OtherInfo) {}
+
+    WorklistItem(unsigned AncestorIdx, CompileUnit &CU, unsigned Flags)
+        : Type(WorklistItemType::LookForParentDIEsToKeep), CU(CU), Flags(Flags),
+          AncestorIdx(AncestorIdx) {}
+  };
+
+  /// returns true if we need to translate strings.
+  bool needToTranslateStrings() { return StringsTranslator != nullptr; }
+
+  void reportWarning(const Twine &Warning, const DWARFFile &File,
+                     const DWARFDie *DIE = nullptr) const {
+    if (Options.WarningHandler != nullptr)
+      Options.WarningHandler(Warning, File.FileName, DIE);
+  }
+
+  void reportError(const Twine &Warning, const DWARFFile &File,
+                   const DWARFDie *DIE = nullptr) const {
+    if (Options.ErrorHandler != nullptr)
+      Options.ErrorHandler(Warning, File.FileName, DIE);
+  }
+
+  /// Remembers the oldest and newest DWARF version we've seen in a unit.
+  void updateDwarfVersion(unsigned Version) {
+    MaxDwarfVersion = std::max(MaxDwarfVersion, Version);
+    MinDwarfVersion = std::min(MinDwarfVersion, Version);
+  }
+
+  /// Remembers the kinds of accelerator tables we've seen in a unit.
+  void updateAccelKind(DWARFContext &Dwarf);
+
+  /// Emit warnings as Dwarf compile units to leave a trail after linking.
+  bool emitPaperTrailWarnings(const DWARFFile &File,
+                              OffsetsStringPool &StringPool);
+
+  void copyInvariantDebugSection(DWARFContext &Dwarf);
+
+  /// Keeps track of data associated with one object during linking.
+  struct LinkContext {
+    DWARFFile &File;
+    UnitListTy CompileUnits;
+    bool Skip = false;
+
+    LinkContext(DWARFFile &File) : File(File) {}
+
+    /// Clear part of the context that's no longer needed when we're done with
+    /// the debug object.
+    void clear() {
+      CompileUnits.clear();
+      File.Addresses->clear();
+    }
+  };
+
+  /// Called before emitting object data
+  void cleanupAuxiliarryData(LinkContext &Context);
+
+  /// Look at the parent of the given DIE and decide whether they should be
+  /// kept.
+  void lookForParentDIEsToKeep(unsigned AncestorIdx, CompileUnit &CU,
+                               unsigned Flags,
+                               SmallVectorImpl<WorklistItem> &Worklist);
+
+  /// Look at the children of the given DIE and decide whether they should be
+  /// kept.
+  void lookForChildDIEsToKeep(const DWARFDie &Die, CompileUnit &CU,
+                              unsigned Flags,
+                              SmallVectorImpl<WorklistItem> &Worklist);
+
+  /// Look at DIEs referenced by the given DIE and decide whether they should be
+  /// kept. All DIEs referenced though attributes should be kept.
+  void lookForRefDIEsToKeep(const DWARFDie &Die, CompileUnit &CU,
+                            unsigned Flags, const UnitListTy &Units,
+                            const DWARFFile &File,
+                            SmallVectorImpl<WorklistItem> &Worklist);
+
+  /// \defgroup FindRootDIEs Find DIEs corresponding to Address map entries.
+  ///
+  /// @{
+  /// Recursively walk the \p DIE tree and look for DIEs to
+  /// keep. Store that information in \p CU's DIEInfo.
+  ///
+  /// The return value indicates whether the DIE is incomplete.
+  void lookForDIEsToKeep(AddressesMap &RelocMgr, RangesTy &Ranges,
+                         const UnitListTy &Units, const DWARFDie &DIE,
+                         const DWARFFile &File, CompileUnit &CU,
+                         unsigned Flags);
+
+  /// If this compile unit is really a skeleton CU that points to a
+  /// clang module, register it in ClangModules and return true.
+  ///
+  /// A skeleton CU is a CU without children, a DW_AT_gnu_dwo_name
+  /// pointing to the module, and a DW_AT_gnu_dwo_id with the module
+  /// hash.
+  bool registerModuleReference(DWARFDie CUDie, const DWARFUnit &Unit,
+                               const DWARFFile &File,
+                               OffsetsStringPool &OffsetsStringPool,
+                               DeclContextTree &ODRContexts,
+                               uint64_t ModulesEndOffset, unsigned &UnitID,
+                               bool IsLittleEndian, unsigned Indent = 0,
+                               bool Quiet = false);
+
+  /// Recursively add the debug info in this clang module .pcm
+  /// file (and all the modules imported by it in a bottom-up fashion)
+  /// to Units.
+  Error loadClangModule(DWARFDie CUDie, StringRef FilePath,
+                        StringRef ModuleName, uint64_t DwoId,
+                        const DWARFFile &File,
+                        OffsetsStringPool &OffsetsStringPool,
+                        DeclContextTree &ODRContexts, uint64_t ModulesEndOffset,
+                        unsigned &UnitID, bool IsLittleEndian,
+                        unsigned Indent = 0, bool Quiet = false);
+
+  /// Mark the passed DIE as well as all the ones it depends on as kept.
+  void keepDIEAndDependencies(AddressesMap &RelocMgr, RangesTy &Ranges,
+                              const UnitListTy &Units, const DWARFDie &DIE,
+                              CompileUnit::DIEInfo &MyInfo,
+                              const DWARFFile &File, CompileUnit &CU,
+                              bool UseODR);
+
+  unsigned shouldKeepDIE(AddressesMap &RelocMgr, RangesTy &Ranges,
+                         const DWARFDie &DIE, const DWARFFile &File,
+                         CompileUnit &Unit, CompileUnit::DIEInfo &MyInfo,
+                         unsigned Flags);
+
+  /// Check if a variable describing DIE should be kept.
+  /// \returns updated TraversalFlags.
+  unsigned shouldKeepVariableDIE(AddressesMap &RelocMgr, const DWARFDie &DIE,
+                                 CompileUnit::DIEInfo &MyInfo, unsigned Flags);
+
+  unsigned shouldKeepSubprogramDIE(AddressesMap &RelocMgr, RangesTy &Ranges,
+                                   const DWARFDie &DIE, const DWARFFile &File,
+                                   CompileUnit &Unit,
+                                   CompileUnit::DIEInfo &MyInfo,
+                                   unsigned Flags);
+
+  /// Resolve the DIE attribute reference that has been extracted in \p
+  /// RefValue. The resulting DIE might be in another CompileUnit which is
+  /// stored into \p ReferencedCU. \returns null if resolving fails for any
+  /// reason.
+  DWARFDie resolveDIEReference(const DWARFFile &File, const UnitListTy &Units,
+                               const DWARFFormValue &RefValue,
+                               const DWARFDie &DIE, CompileUnit *&RefCU);
+
+  /// @}
+
+  /// \defgroup Methods used to link the debug information
+  ///
+  /// @{
+
+  struct DWARFLinkerOptions;
+
+  class DIECloner {
+    DWARFLinker &Linker;
+    DwarfEmitter *Emitter;
+    DWARFFile &ObjFile;
+
+    /// Allocator used for all the DIEValue objects.
+    BumpPtrAllocator &DIEAlloc;
+
+    std::vector<std::unique_ptr<CompileUnit>> &CompileUnits;
+
+    bool Update;
+
+  public:
+    DIECloner(DWARFLinker &Linker, DwarfEmitter *Emitter, DWARFFile &ObjFile,
+              BumpPtrAllocator &DIEAlloc,
+              std::vector<std::unique_ptr<CompileUnit>> &CompileUnits,
+              bool Update)
+        : Linker(Linker), Emitter(Emitter), ObjFile(ObjFile),
+          DIEAlloc(DIEAlloc), CompileUnits(CompileUnits), Update(Update) {}
+
+    /// Recursively clone \p InputDIE into an tree of DIE objects
+    /// where useless (as decided by lookForDIEsToKeep()) bits have been
+    /// stripped out and addresses have been rewritten according to the
+    /// address map.
+    ///
+    /// \param OutOffset is the offset the cloned DIE in the output
+    /// compile unit.
+    /// \param PCOffset (while cloning a function scope) is the offset
+    /// applied to the entry point of the function to get the linked address.
+    /// \param Die the output DIE to use, pass NULL to create one.
+    /// \returns the root of the cloned tree or null if nothing was selected.
+    DIE *cloneDIE(const DWARFDie &InputDIE, const DWARFFile &File,
+                  CompileUnit &U, OffsetsStringPool &StringPool,
+                  int64_t PCOffset, uint32_t OutOffset, unsigned Flags,
+                  bool IsLittleEndian, DIE *Die = nullptr);
+
+    /// Construct the output DIE tree by cloning the DIEs we
+    /// chose to keep above. If there are no valid relocs, then there's
+    /// nothing to clone/emit.
+    uint64_t cloneAllCompileUnits(DWARFContext &DwarfContext,
+                                  const DWARFFile &File,
+                                  OffsetsStringPool &StringPool,
+                                  bool IsLittleEndian);
+
+  private:
+    using AttributeSpec = DWARFAbbreviationDeclaration::AttributeSpec;
+
+    /// Information gathered and exchanged between the various
+    /// clone*Attributes helpers about the attributes of a particular DIE.
+    struct AttributesInfo {
+      /// Names.
+      DwarfStringPoolEntryRef Name, MangledName, NameWithoutTemplate;
+
+      /// Offsets in the string pool.
+      uint32_t NameOffset = 0;
+      uint32_t MangledNameOffset = 0;
+
+      /// Value of AT_low_pc in the input DIE
+      uint64_t OrigLowPc = std::numeric_limits<uint64_t>::max();
+
+      /// Value of AT_high_pc in the input DIE
+      uint64_t OrigHighPc = 0;
+
+      /// Value of DW_AT_call_return_pc in the input DIE
+      uint64_t OrigCallReturnPc = 0;
+
+      /// Value of DW_AT_call_pc in the input DIE
+      uint64_t OrigCallPc = 0;
+
+      /// Offset to apply to PC addresses inside a function.
+      int64_t PCOffset = 0;
+
+      /// Does the DIE have a low_pc attribute?
+      bool HasLowPc = false;
+
+      /// Does the DIE have a ranges attribute?
+      bool HasRanges = false;
+
+      /// Is this DIE only a declaration?
+      bool IsDeclaration = false;
+
+      AttributesInfo() = default;
+    };
+
+    /// Helper for cloneDIE.
+    unsigned cloneAttribute(DIE &Die, const DWARFDie &InputDIE,
+                            const DWARFFile &File, CompileUnit &U,
+                            OffsetsStringPool &StringPool,
+                            const DWARFFormValue &Val,
+                            const AttributeSpec AttrSpec, unsigned AttrSize,
+                            AttributesInfo &AttrInfo, bool IsLittleEndian);
+
+    /// Clone a string attribute described by \p AttrSpec and add
+    /// it to \p Die.
+    /// \returns the size of the new attribute.
+    unsigned cloneStringAttribute(DIE &Die, AttributeSpec AttrSpec,
+                                  const DWARFFormValue &Val, const DWARFUnit &U,
+                                  OffsetsStringPool &StringPool,
+                                  AttributesInfo &Info);
+
+    /// Clone an attribute referencing another DIE and add
+    /// it to \p Die.
+    /// \returns the size of the new attribute.
+    unsigned cloneDieReferenceAttribute(DIE &Die, const DWARFDie &InputDIE,
+                                        AttributeSpec AttrSpec,
+                                        unsigned AttrSize,
+                                        const DWARFFormValue &Val,
+                                        const DWARFFile &File,
+                                        CompileUnit &Unit);
+
+    /// Clone a DWARF expression that may be referencing another DIE.
+    void cloneExpression(DataExtractor &Data, DWARFExpression Expression,
+                         const DWARFFile &File, CompileUnit &Unit,
+                         SmallVectorImpl<uint8_t> &OutputBuffer);
+
+    /// Clone an attribute referencing another DIE and add
+    /// it to \p Die.
+    /// \returns the size of the new attribute.
+    unsigned cloneBlockAttribute(DIE &Die, const DWARFFile &File,
+                                 CompileUnit &Unit, AttributeSpec AttrSpec,
+                                 const DWARFFormValue &Val, unsigned AttrSize,
+                                 bool IsLittleEndian);
+
+    /// Clone an attribute referencing another DIE and add
+    /// it to \p Die.
+    /// \returns the size of the new attribute.
+    unsigned cloneAddressAttribute(DIE &Die, AttributeSpec AttrSpec,
+                                   const DWARFFormValue &Val,
+                                   const CompileUnit &Unit,
+                                   AttributesInfo &Info);
+
+    /// Clone a scalar attribute  and add it to \p Die.
+    /// \returns the size of the new attribute.
+    unsigned cloneScalarAttribute(DIE &Die, const DWARFDie &InputDIE,
+                                  const DWARFFile &File, CompileUnit &U,
+                                  AttributeSpec AttrSpec,
+                                  const DWARFFormValue &Val, unsigned AttrSize,
+                                  AttributesInfo &Info);
+
+    /// Get the potential name and mangled name for the entity
+    /// described by \p Die and store them in \Info if they are not
+    /// already there.
+    /// \returns is a name was found.
+    bool getDIENames(const DWARFDie &Die, AttributesInfo &Info,
+                     OffsetsStringPool &StringPool, bool StripTemplate = false);
+
+    /// Create a copy of abbreviation Abbrev.
+    void copyAbbrev(const DWARFAbbreviationDeclaration &Abbrev, bool hasODR);
+
+    uint32_t hashFullyQualifiedName(DWARFDie DIE, CompileUnit &U,
+                                    const DWARFFile &File,
+                                    int RecurseDepth = 0);
+
+    /// Helper for cloneDIE.
+    void addObjCAccelerator(CompileUnit &Unit, const DIE *Die,
+                            DwarfStringPoolEntryRef Name,
+                            OffsetsStringPool &StringPool, bool SkipPubSection);
+  };
+
+  /// Assign an abbreviation number to \p Abbrev
+  void assignAbbrev(DIEAbbrev &Abbrev);
+
+  /// Compute and emit .debug_ranges section for \p Unit, and
+  /// patch the attributes referencing it.
+  void patchRangesForUnit(const CompileUnit &Unit, DWARFContext &Dwarf,
+                          const DWARFFile &File) const;
+
+  /// Generate and emit the DW_AT_ranges attribute for a compile_unit if it had
+  /// one.
+  void generateUnitRanges(CompileUnit &Unit) const;
+
+  /// Extract the line tables from the original dwarf, extract the relevant
+  /// parts according to the linked function ranges and emit the result in the
+  /// .debug_line section.
+  void patchLineTableForUnit(CompileUnit &Unit, DWARFContext &OrigDwarf,
+                             const DWARFFile &File);
+
+  /// Emit the accelerator entries for \p Unit.
+  void emitAcceleratorEntriesForUnit(CompileUnit &Unit);
+  void emitDwarfAcceleratorEntriesForUnit(CompileUnit &Unit);
+  void emitAppleAcceleratorEntriesForUnit(CompileUnit &Unit);
+  void emitPubAcceleratorEntriesForUnit(CompileUnit &Unit);
+
+  /// Patch the frame info for an object file and emit it.
+  void patchFrameInfoForObject(const DWARFFile &, RangesTy &Ranges,
+                               DWARFContext &, unsigned AddressSize);
+
+  /// FoldingSet that uniques the abbreviations.
+  FoldingSet<DIEAbbrev> AbbreviationsSet;
+
+  /// Storage for the unique Abbreviations.
+  /// This is passed to AsmPrinter::emitDwarfAbbrevs(), thus it cannot be
+  /// changed to a vector of unique_ptrs.
+  std::vector<std::unique_ptr<DIEAbbrev>> Abbreviations;
+
+  /// DIELoc objects that need to be destructed (but not freed!).
+  std::vector<DIELoc *> DIELocs;
+
+  /// DIEBlock objects that need to be destructed (but not freed!).
+  std::vector<DIEBlock *> DIEBlocks;
+
+  /// Allocator used for all the DIEValue objects.
+  BumpPtrAllocator DIEAlloc;
+  /// @}
+
+  DwarfEmitter *TheDwarfEmitter;
+  std::vector<LinkContext> ObjectContexts;
+
+  unsigned MaxDwarfVersion = 0;
+  unsigned MinDwarfVersion = std::numeric_limits<unsigned>::max();
+
+  bool AtLeastOneAppleAccelTable = false;
+  bool AtLeastOneDwarfAccelTable = false;
+
+  /// The CIEs that have been emitted in the output section. The actual CIE
+  /// data serves a the key to this StringMap, this takes care of comparing the
+  /// semantics of CIEs defined in different object files.
+  StringMap<uint32_t> EmittedCIEs;
+
+  /// Offset of the last CIE that has been emitted in the output
+  /// .debug_frame section.
+  uint32_t LastCIEOffset = 0;
+
+  /// Apple accelerator tables.
+  AccelTable<DWARF5AccelTableStaticData> DebugNames;
+  AccelTable<AppleAccelTableStaticOffsetData> AppleNames;
+  AccelTable<AppleAccelTableStaticOffsetData> AppleNamespaces;
+  AccelTable<AppleAccelTableStaticOffsetData> AppleObjc;
+  AccelTable<AppleAccelTableStaticTypeData> AppleTypes;
+
+  /// Mapping the PCM filename to the DwoId.
+  StringMap<uint64_t> ClangModules;
+
+  DwarfLinkerClient DwarfLinkerClientID;
+
+  std::function<StringRef(StringRef)> StringsTranslator = nullptr;
+
+  /// linking options
+  struct DWARFLinkerOptions {
+    /// Generate processing log to the standard output.
+    bool Verbose = false;
+
+    /// Print statistics.
+    bool Statistics = false;
+
+    /// Skip emitting output
+    bool NoOutput = false;
+
+    /// Do not unique types according to ODR
+    bool NoODR = false;
+
+    /// Update
+    bool Update = false;
+
+    /// Whether we want a static variable to force us to keep its enclosing
+    /// function.
+    bool KeepFunctionForStatic = false;
+
+    /// Number of threads.
+    unsigned Threads = 1;
+
+    /// The accelerator table kind
+    AccelTableKind TheAccelTableKind = AccelTableKind::Default;
+
+    /// Prepend path for the clang modules.
+    std::string PrependPath;
+
+    // warning handler
+    messageHandler WarningHandler = nullptr;
+
+    // error handler
+    messageHandler ErrorHandler = nullptr;
+
+    objFileLoader ObjFileLoader = nullptr;
+
+    /// A list of all .swiftinterface files referenced by the debug
+    /// info, mapping Module name to path on disk. The entries need to
+    /// be uniqued and sorted and there are only few entries expected
+    /// per compile unit, which is why this is a std::map.
+    /// this is dsymutil specific fag.
+    swiftInterfacesMap *ParseableSwiftInterfaces = nullptr;
+
+    /// A list of remappings to apply to file paths.
+    objectPrefixMap *ObjectPrefixMap = nullptr;
+  } Options;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_DWARFLINKER_DWARFLINKER_H
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif