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, 870 insertions, 0 deletions

diff --git a/contrib/libs/llvm16/lib/Object/ArchiveWriter.cpp b/contrib/libs/llvm16/lib/Object/ArchiveWriter.cpp
new file mode 100644
index 0000000000..0d3aad658f
--- /dev/null
+++ b/contrib/libs/llvm16/lib/Object/ArchiveWriter.cpp
@@ -0,0 +1,870 @@
+//===- ArchiveWriter.cpp - ar File Format implementation --------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the writeArchive function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/ArchiveWriter.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/BinaryFormat/Magic.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/Object/Archive.h"
+#include "llvm/Object/Error.h"
+#include "llvm/Object/IRObjectFile.h"
+#include "llvm/Object/MachO.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Object/SymbolicFile.h"
+#include "llvm/Object/XCOFFObjectFile.h"
+#include "llvm/Support/Alignment.h"
+#include "llvm/Support/EndianStream.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/SmallVectorMemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <map>
+
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
+
+using namespace llvm;
+
+NewArchiveMember::NewArchiveMember(MemoryBufferRef BufRef)
+    : Buf(MemoryBuffer::getMemBuffer(BufRef, false)),
+      MemberName(BufRef.getBufferIdentifier()) {}
+
+object::Archive::Kind NewArchiveMember::detectKindFromObject() const {
+  auto MemBufferRef = this->Buf->getMemBufferRef();
+  Expected<std::unique_ptr<object::ObjectFile>> OptionalObject =
+      object::ObjectFile::createObjectFile(MemBufferRef);
+
+  if (OptionalObject)
+    return isa<object::MachOObjectFile>(**OptionalObject)
+               ? object::Archive::K_DARWIN
+               : (isa<object::XCOFFObjectFile>(**OptionalObject)
+                      ? object::Archive::K_AIXBIG
+                      : object::Archive::K_GNU);
+
+  // Squelch the error in case we had a non-object file.
+  consumeError(OptionalObject.takeError());
+
+  // If we're adding a bitcode file to the archive, detect the Archive kind
+  // based on the target triple.
+  LLVMContext Context;
+  if (identify_magic(MemBufferRef.getBuffer()) == file_magic::bitcode) {
+    if (auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
+            MemBufferRef, file_magic::bitcode, &Context)) {
+      auto &IRObject = cast<object::IRObjectFile>(**ObjOrErr);
+      return Triple(IRObject.getTargetTriple()).isOSDarwin()
+                 ? object::Archive::K_DARWIN
+                 : object::Archive::K_GNU;
+    } else {
+      // Squelch the error in case this was not a SymbolicFile.
+      consumeError(ObjOrErr.takeError());
+    }
+  }
+
+  return object::Archive::getDefaultKindForHost();
+}
+
+Expected<NewArchiveMember>
+NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
+                               bool Deterministic) {
+  Expected<llvm::MemoryBufferRef> BufOrErr = OldMember.getMemoryBufferRef();
+  if (!BufOrErr)
+    return BufOrErr.takeError();
+
+  NewArchiveMember M;
+  M.Buf = MemoryBuffer::getMemBuffer(*BufOrErr, false);
+  M.MemberName = M.Buf->getBufferIdentifier();
+  if (!Deterministic) {
+    auto ModTimeOrErr = OldMember.getLastModified();
+    if (!ModTimeOrErr)
+      return ModTimeOrErr.takeError();
+    M.ModTime = ModTimeOrErr.get();
+    Expected<unsigned> UIDOrErr = OldMember.getUID();
+    if (!UIDOrErr)
+      return UIDOrErr.takeError();
+    M.UID = UIDOrErr.get();
+    Expected<unsigned> GIDOrErr = OldMember.getGID();
+    if (!GIDOrErr)
+      return GIDOrErr.takeError();
+    M.GID = GIDOrErr.get();
+    Expected<sys::fs::perms> AccessModeOrErr = OldMember.getAccessMode();
+    if (!AccessModeOrErr)
+      return AccessModeOrErr.takeError();
+    M.Perms = AccessModeOrErr.get();
+  }
+  return std::move(M);
+}
+
+Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
+                                                     bool Deterministic) {
+  sys::fs::file_status Status;
+  auto FDOrErr = sys::fs::openNativeFileForRead(FileName);
+  if (!FDOrErr)
+    return FDOrErr.takeError();
+  sys::fs::file_t FD = *FDOrErr;
+  assert(FD != sys::fs::kInvalidFile);
+
+  if (auto EC = sys::fs::status(FD, Status))
+    return errorCodeToError(EC);
+
+  // Opening a directory doesn't make sense. Let it fail.
+  // Linux cannot open directories with open(2), although
+  // cygwin and *bsd can.
+  if (Status.type() == sys::fs::file_type::directory_file)
+    return errorCodeToError(make_error_code(errc::is_a_directory));
+
+  ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
+      MemoryBuffer::getOpenFile(FD, FileName, Status.getSize(), false);
+  if (!MemberBufferOrErr)
+    return errorCodeToError(MemberBufferOrErr.getError());
+
+  if (auto EC = sys::fs::closeFile(FD))
+    return errorCodeToError(EC);
+
+  NewArchiveMember M;
+  M.Buf = std::move(*MemberBufferOrErr);
+  M.MemberName = M.Buf->getBufferIdentifier();
+  if (!Deterministic) {
+    M.ModTime = std::chrono::time_point_cast<std::chrono::seconds>(
+        Status.getLastModificationTime());
+    M.UID = Status.getUser();
+    M.GID = Status.getGroup();
+    M.Perms = Status.permissions();
+  }
+  return std::move(M);
+}
+
+template <typename T>
+static void printWithSpacePadding(raw_ostream &OS, T Data, unsigned Size) {
+  uint64_t OldPos = OS.tell();
+  OS << Data;
+  unsigned SizeSoFar = OS.tell() - OldPos;
+  assert(SizeSoFar <= Size && "Data doesn't fit in Size");
+  OS.indent(Size - SizeSoFar);
+}
+
+static bool isDarwin(object::Archive::Kind Kind) {
+  return Kind == object::Archive::K_DARWIN ||
+         Kind == object::Archive::K_DARWIN64;
+}
+
+static bool isAIXBigArchive(object::Archive::Kind Kind) {
+  return Kind == object::Archive::K_AIXBIG;
+}
+
+static bool isBSDLike(object::Archive::Kind Kind) {
+  switch (Kind) {
+  case object::Archive::K_GNU:
+  case object::Archive::K_GNU64:
+  case object::Archive::K_AIXBIG:
+    return false;
+  case object::Archive::K_BSD:
+  case object::Archive::K_DARWIN:
+  case object::Archive::K_DARWIN64:
+    return true;
+  case object::Archive::K_COFF:
+    break;
+  }
+  llvm_unreachable("not supported for writting");
+}
+
+template <class T>
+static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val) {
+  support::endian::write(Out, Val,
+                         isBSDLike(Kind) ? support::little : support::big);
+}
+
+static void printRestOfMemberHeader(
+    raw_ostream &Out, const sys::TimePoint<std::chrono::seconds> &ModTime,
+    unsigned UID, unsigned GID, unsigned Perms, uint64_t Size) {
+  printWithSpacePadding(Out, sys::toTimeT(ModTime), 12);
+
+  // The format has only 6 chars for uid and gid. Truncate if the provided
+  // values don't fit.
+  printWithSpacePadding(Out, UID % 1000000, 6);
+  printWithSpacePadding(Out, GID % 1000000, 6);
+
+  printWithSpacePadding(Out, format("%o", Perms), 8);
+  printWithSpacePadding(Out, Size, 10);
+  Out << "`\n";
+}
+
+static void
+printGNUSmallMemberHeader(raw_ostream &Out, StringRef Name,
+                          const sys::TimePoint<std::chrono::seconds> &ModTime,
+                          unsigned UID, unsigned GID, unsigned Perms,
+                          uint64_t Size) {
+  printWithSpacePadding(Out, Twine(Name) + "/", 16);
+  printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
+}
+
+static void
+printBSDMemberHeader(raw_ostream &Out, uint64_t Pos, StringRef Name,
+                     const sys::TimePoint<std::chrono::seconds> &ModTime,
+                     unsigned UID, unsigned GID, unsigned Perms, uint64_t Size) {
+  uint64_t PosAfterHeader = Pos + 60 + Name.size();
+  // Pad so that even 64 bit object files are aligned.
+  unsigned Pad = offsetToAlignment(PosAfterHeader, Align(8));
+  unsigned NameWithPadding = Name.size() + Pad;
+  printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
+  printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
+                          NameWithPadding + Size);
+  Out << Name;
+  while (Pad--)
+    Out.write(uint8_t(0));
+}
+
+static void
+printBigArchiveMemberHeader(raw_ostream &Out, StringRef Name,
+                            const sys::TimePoint<std::chrono::seconds> &ModTime,
+                            unsigned UID, unsigned GID, unsigned Perms,
+                            uint64_t Size, unsigned PrevOffset,
+                            unsigned NextOffset) {
+  unsigned NameLen = Name.size();
+
+  printWithSpacePadding(Out, Size, 20);           // File member size
+  printWithSpacePadding(Out, NextOffset, 20);     // Next member header offset
+  printWithSpacePadding(Out, PrevOffset, 20); // Previous member header offset
+  printWithSpacePadding(Out, sys::toTimeT(ModTime), 12); // File member date
+  // The big archive format has 12 chars for uid and gid.
+  printWithSpacePadding(Out, UID % 1000000000000, 12);   // UID
+  printWithSpacePadding(Out, GID % 1000000000000, 12);   // GID
+  printWithSpacePadding(Out, format("%o", Perms), 12);   // Permission
+  printWithSpacePadding(Out, NameLen, 4);                // Name length
+  if (NameLen) {
+    printWithSpacePadding(Out, Name, NameLen); // Name
+    if (NameLen % 2)
+      Out.write(uint8_t(0)); // Null byte padding
+  }
+  Out << "`\n"; // Terminator
+}
+
+static bool useStringTable(bool Thin, StringRef Name) {
+  return Thin || Name.size() >= 16 || Name.contains('/');
+}
+
+static bool is64BitKind(object::Archive::Kind Kind) {
+  switch (Kind) {
+  case object::Archive::K_GNU:
+  case object::Archive::K_BSD:
+  case object::Archive::K_DARWIN:
+  case object::Archive::K_COFF:
+    return false;
+  case object::Archive::K_AIXBIG:
+  case object::Archive::K_DARWIN64:
+  case object::Archive::K_GNU64:
+    return true;
+  }
+  llvm_unreachable("not supported for writting");
+}
+
+static void
+printMemberHeader(raw_ostream &Out, uint64_t Pos, raw_ostream &StringTable,
+                  StringMap<uint64_t> &MemberNames, object::Archive::Kind Kind,
+                  bool Thin, const NewArchiveMember &M,
+                  sys::TimePoint<std::chrono::seconds> ModTime, uint64_t Size) {
+  if (isBSDLike(Kind))
+    return printBSDMemberHeader(Out, Pos, M.MemberName, ModTime, M.UID, M.GID,
+                                M.Perms, Size);
+  if (!useStringTable(Thin, M.MemberName))
+    return printGNUSmallMemberHeader(Out, M.MemberName, ModTime, M.UID, M.GID,
+                                     M.Perms, Size);
+  Out << '/';
+  uint64_t NamePos;
+  if (Thin) {
+    NamePos = StringTable.tell();
+    StringTable << M.MemberName << "/\n";
+  } else {
+    auto Insertion = MemberNames.insert({M.MemberName, uint64_t(0)});
+    if (Insertion.second) {
+      Insertion.first->second = StringTable.tell();
+      StringTable << M.MemberName << "/\n";
+    }
+    NamePos = Insertion.first->second;
+  }
+  printWithSpacePadding(Out, NamePos, 15);
+  printRestOfMemberHeader(Out, ModTime, M.UID, M.GID, M.Perms, Size);
+}
+
+namespace {
+struct MemberData {
+  std::vector<unsigned> Symbols;
+  std::string Header;
+  StringRef Data;
+  StringRef Padding;
+};
+} // namespace
+
+static MemberData computeStringTable(StringRef Names) {
+  unsigned Size = Names.size();
+  unsigned Pad = offsetToAlignment(Size, Align(2));
+  std::string Header;
+  raw_string_ostream Out(Header);
+  printWithSpacePadding(Out, "//", 48);
+  printWithSpacePadding(Out, Size + Pad, 10);
+  Out << "`\n";
+  Out.flush();
+  return {{}, std::move(Header), Names, Pad ? "\n" : ""};
+}
+
+static sys::TimePoint<std::chrono::seconds> now(bool Deterministic) {
+  using namespace std::chrono;
+
+  if (!Deterministic)
+    return time_point_cast<seconds>(system_clock::now());
+  return sys::TimePoint<seconds>();
+}
+
+static bool isArchiveSymbol(const object::BasicSymbolRef &S) {
+  Expected<uint32_t> SymFlagsOrErr = S.getFlags();
+  if (!SymFlagsOrErr)
+    // TODO: Actually report errors helpfully.
+    report_fatal_error(SymFlagsOrErr.takeError());
+  if (*SymFlagsOrErr & object::SymbolRef::SF_FormatSpecific)
+    return false;
+  if (!(*SymFlagsOrErr & object::SymbolRef::SF_Global))
+    return false;
+  if (*SymFlagsOrErr & object::SymbolRef::SF_Undefined)
+    return false;
+  return true;
+}
+
+static void printNBits(raw_ostream &Out, object::Archive::Kind Kind,
+                       uint64_t Val) {
+  if (is64BitKind(Kind))
+    print<uint64_t>(Out, Kind, Val);
+  else
+    print<uint32_t>(Out, Kind, Val);
+}
+
+static uint64_t computeSymbolTableSize(object::Archive::Kind Kind,
+                                       uint64_t NumSyms, uint64_t OffsetSize,
+                                       StringRef StringTable,
+                                       uint32_t *Padding = nullptr) {
+  assert((OffsetSize == 4 || OffsetSize == 8) && "Unsupported OffsetSize");
+  uint64_t Size = OffsetSize; // Number of entries
+  if (isBSDLike(Kind))
+    Size += NumSyms * OffsetSize * 2; // Table
+  else
+    Size += NumSyms * OffsetSize; // Table
+  if (isBSDLike(Kind))
+    Size += OffsetSize; // byte count
+  Size += StringTable.size();
+  // ld64 expects the members to be 8-byte aligned for 64-bit content and at
+  // least 4-byte aligned for 32-bit content.  Opt for the larger encoding
+  // uniformly.
+  // We do this for all bsd formats because it simplifies aligning members.
+  // For the big archive format, the symbol table is the last member, so there
+  // is no need to align.
+  uint32_t Pad = isAIXBigArchive(Kind)
+                     ? 0
+                     : offsetToAlignment(Size, Align(isBSDLike(Kind) ? 8 : 2));
+  Size += Pad;
+  if (Padding)
+    *Padding = Pad;
+  return Size;
+}
+
+static void writeSymbolTableHeader(raw_ostream &Out, object::Archive::Kind Kind,
+                                   bool Deterministic, uint64_t Size,
+                                   uint64_t PrevMemberOffset = 0) {
+  if (isBSDLike(Kind)) {
+    const char *Name = is64BitKind(Kind) ? "__.SYMDEF_64" : "__.SYMDEF";
+    printBSDMemberHeader(Out, Out.tell(), Name, now(Deterministic), 0, 0, 0,
+                         Size);
+  } else if (isAIXBigArchive(Kind)) {
+    printBigArchiveMemberHeader(Out, "", now(Deterministic), 0, 0,
+                                0, Size, PrevMemberOffset, 0);
+  } else {
+    const char *Name = is64BitKind(Kind) ? "/SYM64" : "";
+    printGNUSmallMemberHeader(Out, Name, now(Deterministic), 0, 0, 0, Size);
+  }
+}
+
+static void writeSymbolTable(raw_ostream &Out, object::Archive::Kind Kind,
+                             bool Deterministic, ArrayRef<MemberData> Members,
+                             StringRef StringTable,
+                             uint64_t PrevMemberOffset = 0) {
+  // We don't write a symbol table on an archive with no members -- except on
+  // Darwin, where the linker will abort unless the archive has a symbol table.
+  if (StringTable.empty() && !isDarwin(Kind))
+    return;
+
+  unsigned NumSyms = 0;
+  for (const MemberData &M : Members)
+    NumSyms += M.Symbols.size();
+
+  uint64_t OffsetSize = is64BitKind(Kind) ? 8 : 4;
+  uint32_t Pad;
+  uint64_t Size = computeSymbolTableSize(Kind, NumSyms, OffsetSize, StringTable, &Pad);
+  writeSymbolTableHeader(Out, Kind, Deterministic, Size, PrevMemberOffset);
+
+  uint64_t Pos = isAIXBigArchive(Kind) ? sizeof(object::BigArchive::FixLenHdr)
+                                       : Out.tell() + Size;
+
+  if (isBSDLike(Kind))
+    printNBits(Out, Kind, NumSyms * 2 * OffsetSize);
+  else
+    printNBits(Out, Kind, NumSyms);
+
+  for (const MemberData &M : Members) {
+    for (unsigned StringOffset : M.Symbols) {
+      if (isBSDLike(Kind))
+        printNBits(Out, Kind, StringOffset);
+      printNBits(Out, Kind, Pos); // member offset
+    }
+    Pos += M.Header.size() + M.Data.size() + M.Padding.size();
+  }
+
+  if (isBSDLike(Kind))
+    // byte count of the string table
+    printNBits(Out, Kind, StringTable.size());
+  Out << StringTable;
+
+  while (Pad--)
+    Out.write(uint8_t(0));
+}
+
+static Expected<std::vector<unsigned>>
+getSymbols(MemoryBufferRef Buf, raw_ostream &SymNames, bool &HasObject) {
+  std::vector<unsigned> Ret;
+
+  // In the scenario when LLVMContext is populated SymbolicFile will contain a
+  // reference to it, thus SymbolicFile should be destroyed first.
+  LLVMContext Context;
+  std::unique_ptr<object::SymbolicFile> Obj;
+
+  const file_magic Type = identify_magic(Buf.getBuffer());
+  // Treat unsupported file types as having no symbols.
+  if (!object::SymbolicFile::isSymbolicFile(Type, &Context))
+    return Ret;
+  if (Type == file_magic::bitcode) {
+    auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
+        Buf, file_magic::bitcode, &Context);
+    if (!ObjOrErr)
+      return ObjOrErr.takeError();
+    Obj = std::move(*ObjOrErr);
+  } else {
+    auto ObjOrErr = object::SymbolicFile::createSymbolicFile(Buf);
+    if (!ObjOrErr)
+      return ObjOrErr.takeError();
+    Obj = std::move(*ObjOrErr);
+  }
+
+  HasObject = true;
+  for (const object::BasicSymbolRef &S : Obj->symbols()) {
+    if (!isArchiveSymbol(S))
+      continue;
+    Ret.push_back(SymNames.tell());
+    if (Error E = S.printName(SymNames))
+      return std::move(E);
+    SymNames << '\0';
+  }
+  return Ret;
+}
+
+static Expected<std::vector<MemberData>>
+computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
+                  object::Archive::Kind Kind, bool Thin, bool Deterministic,
+                  bool NeedSymbols, ArrayRef<NewArchiveMember> NewMembers) {
+  static char PaddingData[8] = {'\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n'};
+
+  uint64_t Pos =
+      isAIXBigArchive(Kind) ? sizeof(object::BigArchive::FixLenHdr) : 0;
+
+  std::vector<MemberData> Ret;
+  bool HasObject = false;
+
+  // Deduplicate long member names in the string table and reuse earlier name
+  // offsets. This especially saves space for COFF Import libraries where all
+  // members have the same name.
+  StringMap<uint64_t> MemberNames;
+
+  // UniqueTimestamps is a special case to improve debugging on Darwin:
+  //
+  // The Darwin linker does not link debug info into the final
+  // binary. Instead, it emits entries of type N_OSO in in the output
+  // binary's symbol table, containing references to the linked-in
+  // object files. Using that reference, the debugger can read the
+  // debug data directly from the object files. Alternatively, an
+  // invocation of 'dsymutil' will link the debug data from the object
+  // files into a dSYM bundle, which can be loaded by the debugger,
+  // instead of the object files.
+  //
+  // For an object file, the N_OSO entries contain the absolute path
+  // path to the file, and the file's timestamp. For an object
+  // included in an archive, the path is formatted like
+  // "/absolute/path/to/archive.a(member.o)", and the timestamp is the
+  // archive member's timestamp, rather than the archive's timestamp.
+  //
+  // However, this doesn't always uniquely identify an object within
+  // an archive -- an archive file can have multiple entries with the
+  // same filename. (This will happen commonly if the original object
+  // files started in different directories.) The only way they get
+  // distinguished, then, is via the timestamp. But this process is
+  // unable to find the correct object file in the archive when there
+  // are two files of the same name and timestamp.
+  //
+  // Additionally, timestamp==0 is treated specially, and causes the
+  // timestamp to be ignored as a match criteria.
+  //
+  // That will "usually" work out okay when creating an archive not in
+  // deterministic timestamp mode, because the objects will probably
+  // have been created at different timestamps.
+  //
+  // To ameliorate this problem, in deterministic archive mode (which
+  // is the default), on Darwin we will emit a unique non-zero
+  // timestamp for each entry with a duplicated name. This is still
+  // deterministic: the only thing affecting that timestamp is the
+  // order of the files in the resultant archive.
+  //
+  // See also the functions that handle the lookup:
+  // in lldb: ObjectContainerBSDArchive::Archive::FindObject()
+  // in llvm/tools/dsymutil: BinaryHolder::GetArchiveMemberBuffers().
+  bool UniqueTimestamps = Deterministic && isDarwin(Kind);
+  std::map<StringRef, unsigned> FilenameCount;
+  if (UniqueTimestamps) {
+    for (const NewArchiveMember &M : NewMembers)
+      FilenameCount[M.MemberName]++;
+    for (auto &Entry : FilenameCount)
+      Entry.second = Entry.second > 1 ? 1 : 0;
+  }
+
+  // The big archive format needs to know the offset of the previous member
+  // header.
+  unsigned PrevOffset = 0;
+  for (const NewArchiveMember &M : NewMembers) {
+    std::string Header;
+    raw_string_ostream Out(Header);
+
+    MemoryBufferRef Buf = M.Buf->getMemBufferRef();
+    StringRef Data = Thin ? "" : Buf.getBuffer();
+
+    // ld64 expects the members to be 8-byte aligned for 64-bit content and at
+    // least 4-byte aligned for 32-bit content.  Opt for the larger encoding
+    // uniformly.  This matches the behaviour with cctools and ensures that ld64
+    // is happy with archives that we generate.
+    unsigned MemberPadding =
+        isDarwin(Kind) ? offsetToAlignment(Data.size(), Align(8)) : 0;
+    unsigned TailPadding =
+        offsetToAlignment(Data.size() + MemberPadding, Align(2));
+    StringRef Padding = StringRef(PaddingData, MemberPadding + TailPadding);
+
+    sys::TimePoint<std::chrono::seconds> ModTime;
+    if (UniqueTimestamps)
+      // Increment timestamp for each file of a given name.
+      ModTime = sys::toTimePoint(FilenameCount[M.MemberName]++);
+    else
+      ModTime = M.ModTime;
+
+    uint64_t Size = Buf.getBufferSize() + MemberPadding;
+    if (Size > object::Archive::MaxMemberSize) {
+      std::string StringMsg =
+          "File " + M.MemberName.str() + " exceeds size limit";
+      return make_error<object::GenericBinaryError>(
+          std::move(StringMsg), object::object_error::parse_failed);
+    }
+
+    if (isAIXBigArchive(Kind)) {
+      unsigned NextOffset = Pos + sizeof(object::BigArMemHdrType) +
+                            alignTo(M.MemberName.size(), 2) + alignTo(Size, 2);
+      printBigArchiveMemberHeader(Out, M.MemberName, ModTime, M.UID, M.GID,
+                                  M.Perms, Size, PrevOffset, NextOffset);
+      PrevOffset = Pos;
+    } else {
+      printMemberHeader(Out, Pos, StringTable, MemberNames, Kind, Thin, M,
+                        ModTime, Size);
+    }
+    Out.flush();
+
+    std::vector<unsigned> Symbols;
+    if (NeedSymbols) {
+      Expected<std::vector<unsigned>> SymbolsOrErr =
+          getSymbols(Buf, SymNames, HasObject);
+      if (!SymbolsOrErr)
+        return createFileError(M.MemberName, SymbolsOrErr.takeError());
+      Symbols = std::move(*SymbolsOrErr);
+    }
+
+    Pos += Header.size() + Data.size() + Padding.size();
+    Ret.push_back({std::move(Symbols), std::move(Header), Data, Padding});
+  }
+  // If there are no symbols, emit an empty symbol table, to satisfy Solaris
+  // tools, older versions of which expect a symbol table in a non-empty
+  // archive, regardless of whether there are any symbols in it.
+  if (HasObject && SymNames.tell() == 0)
+    SymNames << '\0' << '\0' << '\0';
+  return Ret;
+}
+
+namespace llvm {
+
+static ErrorOr<SmallString<128>> canonicalizePath(StringRef P) {
+  SmallString<128> Ret = P;
+  std::error_code Err = sys::fs::make_absolute(Ret);
+  if (Err)
+    return Err;
+  sys::path::remove_dots(Ret, /*removedotdot*/ true);
+  return Ret;
+}
+
+// Compute the relative path from From to To.
+Expected<std::string> computeArchiveRelativePath(StringRef From, StringRef To) {
+  ErrorOr<SmallString<128>> PathToOrErr = canonicalizePath(To);
+  ErrorOr<SmallString<128>> DirFromOrErr = canonicalizePath(From);
+  if (!PathToOrErr || !DirFromOrErr)
+    return errorCodeToError(std::error_code(errno, std::generic_category()));
+
+  const SmallString<128> &PathTo = *PathToOrErr;
+  const SmallString<128> &DirFrom = sys::path::parent_path(*DirFromOrErr);
+
+  // Can't construct a relative path between different roots
+  if (sys::path::root_name(PathTo) != sys::path::root_name(DirFrom))
+    return sys::path::convert_to_slash(PathTo);
+
+  // Skip common prefixes
+  auto FromTo =
+      std::mismatch(sys::path::begin(DirFrom), sys::path::end(DirFrom),
+                    sys::path::begin(PathTo));
+  auto FromI = FromTo.first;
+  auto ToI = FromTo.second;
+
+  // Construct relative path
+  SmallString<128> Relative;
+  for (auto FromE = sys::path::end(DirFrom); FromI != FromE; ++FromI)
+    sys::path::append(Relative, sys::path::Style::posix, "..");
+
+  for (auto ToE = sys::path::end(PathTo); ToI != ToE; ++ToI)
+    sys::path::append(Relative, sys::path::Style::posix, *ToI);
+
+  return std::string(Relative.str());
+}
+
+static Error writeArchiveToStream(raw_ostream &Out,
+                                  ArrayRef<NewArchiveMember> NewMembers,
+                                  bool WriteSymtab, object::Archive::Kind Kind,
+                                  bool Deterministic, bool Thin) {
+  assert((!Thin || !isBSDLike(Kind)) && "Only the gnu format has a thin mode");
+
+  SmallString<0> SymNamesBuf;
+  raw_svector_ostream SymNames(SymNamesBuf);
+  SmallString<0> StringTableBuf;
+  raw_svector_ostream StringTable(StringTableBuf);
+
+  Expected<std::vector<MemberData>> DataOrErr =
+      computeMemberData(StringTable, SymNames, Kind, Thin, Deterministic,
+                        WriteSymtab, NewMembers);
+  if (Error E = DataOrErr.takeError())
+    return E;
+  std::vector<MemberData> &Data = *DataOrErr;
+
+  if (!StringTableBuf.empty() && !isAIXBigArchive(Kind))
+    Data.insert(Data.begin(), computeStringTable(StringTableBuf));
+
+  // We would like to detect if we need to switch to a 64-bit symbol table.
+  uint64_t LastMemberEndOffset =
+      isAIXBigArchive(Kind) ? sizeof(object::BigArchive::FixLenHdr) : 8;
+  uint64_t LastMemberHeaderOffset = LastMemberEndOffset;
+  uint64_t NumSyms = 0;
+  for (const auto &M : Data) {
+    // Record the start of the member's offset
+    LastMemberHeaderOffset = LastMemberEndOffset;
+    // Account for the size of each part associated with the member.
+    LastMemberEndOffset += M.Header.size() + M.Data.size() + M.Padding.size();
+    NumSyms += M.Symbols.size();
+  }
+
+  // The symbol table is put at the end of the big archive file. The symbol
+  // table is at the start of the archive file for other archive formats.
+  if (WriteSymtab && !isAIXBigArchive(Kind)) {
+    // We assume 32-bit offsets to see if 32-bit symbols are possible or not.
+    uint64_t SymtabSize = computeSymbolTableSize(Kind, NumSyms, 4, SymNamesBuf);
+    auto computeSymbolTableHeaderSize =
+        [=] {
+          SmallString<0> TmpBuf;
+          raw_svector_ostream Tmp(TmpBuf);
+          writeSymbolTableHeader(Tmp, Kind, Deterministic, SymtabSize);
+          return TmpBuf.size();
+        };
+    LastMemberHeaderOffset += computeSymbolTableHeaderSize() + SymtabSize;
+
+    // The SYM64 format is used when an archive's member offsets are larger than
+    // 32-bits can hold. The need for this shift in format is detected by
+    // writeArchive. To test this we need to generate a file with a member that
+    // has an offset larger than 32-bits but this demands a very slow test. To
+    // speed the test up we use this environment variable to pretend like the
+    // cutoff happens before 32-bits and instead happens at some much smaller
+    // value.
+    uint64_t Sym64Threshold = 1ULL << 32;
+    const char *Sym64Env = std::getenv("SYM64_THRESHOLD");
+    if (Sym64Env)
+      StringRef(Sym64Env).getAsInteger(10, Sym64Threshold);
+
+    // If LastMemberHeaderOffset isn't going to fit in a 32-bit varible we need
+    // to switch to 64-bit. Note that the file can be larger than 4GB as long as
+    // the last member starts before the 4GB offset.
+    if (LastMemberHeaderOffset >= Sym64Threshold) {
+      if (Kind == object::Archive::K_DARWIN)
+        Kind = object::Archive::K_DARWIN64;
+      else
+        Kind = object::Archive::K_GNU64;
+    }
+  }
+
+  if (Thin)
+    Out << "!<thin>\n";
+  else if (isAIXBigArchive(Kind))
+    Out << "<bigaf>\n";
+  else
+    Out << "!<arch>\n";
+
+  if (!isAIXBigArchive(Kind)) {
+    if (WriteSymtab)
+      writeSymbolTable(Out, Kind, Deterministic, Data, SymNamesBuf);
+    for (const MemberData &M : Data)
+      Out << M.Header << M.Data << M.Padding;
+  } else {
+    // For the big archive (AIX) format, compute a table of member names and
+    // offsets, used in the member table.
+    uint64_t MemberTableNameStrTblSize = 0;
+    std::vector<size_t> MemberOffsets;
+    std::vector<StringRef> MemberNames;
+    // Loop across object to find offset and names.
+    uint64_t MemberEndOffset = sizeof(object::BigArchive::FixLenHdr);
+    for (size_t I = 0, Size = NewMembers.size(); I != Size; ++I) {
+      const NewArchiveMember &Member = NewMembers[I];
+      MemberTableNameStrTblSize += Member.MemberName.size() + 1;
+      MemberOffsets.push_back(MemberEndOffset);
+      MemberNames.push_back(Member.MemberName);
+      // File member name ended with "`\n". The length is included in
+      // BigArMemHdrType.
+      MemberEndOffset += sizeof(object::BigArMemHdrType) +
+                             alignTo(Data[I].Data.size(), 2) +
+                             alignTo(Member.MemberName.size(), 2);
+    }
+
+    // AIX member table size.
+    unsigned MemberTableSize = 20 + // Number of members field
+                               20 * MemberOffsets.size() +
+                               MemberTableNameStrTblSize;
+
+    unsigned GlobalSymbolOffset =
+        (WriteSymtab && NumSyms > 0)
+            ? LastMemberEndOffset +
+                  alignTo(sizeof(object::BigArMemHdrType) + MemberTableSize, 2)
+            : 0;
+
+    // Fixed Sized Header.
+    printWithSpacePadding(Out, NewMembers.size() ? LastMemberEndOffset : 0,
+                          20); // Offset to member table
+    // If there are no file members in the archive, there will be no global
+    // symbol table.
+    printWithSpacePadding(Out, NewMembers.size() ? GlobalSymbolOffset : 0, 20);
+    printWithSpacePadding(
+        Out, 0,
+        20); // Offset to 64 bits global symbol table - Not supported yet
+    printWithSpacePadding(
+        Out, NewMembers.size() ? sizeof(object::BigArchive::FixLenHdr) : 0,
+        20); // Offset to first archive member
+    printWithSpacePadding(Out, NewMembers.size() ? LastMemberHeaderOffset : 0,
+                          20); // Offset to last archive member
+    printWithSpacePadding(
+        Out, 0,
+        20); // Offset to first member of free list - Not supported yet
+
+    for (const MemberData &M : Data) {
+      Out << M.Header << M.Data;
+      if (M.Data.size() % 2)
+        Out << '\0';
+    }
+
+    if (NewMembers.size()) {
+      // Member table.
+      printBigArchiveMemberHeader(Out, "", sys::toTimePoint(0), 0, 0, 0,
+                                  MemberTableSize, LastMemberHeaderOffset,
+                                  GlobalSymbolOffset);
+      printWithSpacePadding(Out, MemberOffsets.size(), 20); // Number of members
+      for (uint64_t MemberOffset : MemberOffsets)
+        printWithSpacePadding(Out, MemberOffset,
+                              20); // Offset to member file header.
+      for (StringRef MemberName : MemberNames)
+        Out << MemberName << '\0'; // Member file name, null byte padding.
+
+      if (MemberTableNameStrTblSize % 2)
+        Out << '\0'; // Name table must be tail padded to an even number of
+                     // bytes.
+
+      if (WriteSymtab && NumSyms > 0)
+        writeSymbolTable(Out, Kind, Deterministic, Data, SymNamesBuf,
+                         LastMemberEndOffset);
+    }
+  }
+  Out.flush();
+  return Error::success();
+}
+
+Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers,
+                   bool WriteSymtab, object::Archive::Kind Kind,
+                   bool Deterministic, bool Thin,
+                   std::unique_ptr<MemoryBuffer> OldArchiveBuf) {
+  Expected<sys::fs::TempFile> Temp =
+      sys::fs::TempFile::create(ArcName + ".temp-archive-%%%%%%%.a");
+  if (!Temp)
+    return Temp.takeError();
+  raw_fd_ostream Out(Temp->FD, false);
+
+  if (Error E = writeArchiveToStream(Out, NewMembers, WriteSymtab, Kind,
+                                     Deterministic, Thin)) {
+    if (Error DiscardError = Temp->discard())
+      return joinErrors(std::move(E), std::move(DiscardError));
+    return E;
+  }
+
+  // At this point, we no longer need whatever backing memory
+  // was used to generate the NewMembers. On Windows, this buffer
+  // could be a mapped view of the file we want to replace (if
+  // we're updating an existing archive, say). In that case, the
+  // rename would still succeed, but it would leave behind a
+  // temporary file (actually the original file renamed) because
+  // a file cannot be deleted while there's a handle open on it,
+  // only renamed. So by freeing this buffer, this ensures that
+  // the last open handle on the destination file, if any, is
+  // closed before we attempt to rename.
+  OldArchiveBuf.reset();
+
+  return Temp->keep(ArcName);
+}
+
+Expected<std::unique_ptr<MemoryBuffer>>
+writeArchiveToBuffer(ArrayRef<NewArchiveMember> NewMembers, bool WriteSymtab,
+                     object::Archive::Kind Kind, bool Deterministic,
+                     bool Thin) {
+  SmallVector<char, 0> ArchiveBufferVector;
+  raw_svector_ostream ArchiveStream(ArchiveBufferVector);
+
+  if (Error E = writeArchiveToStream(ArchiveStream, NewMembers, WriteSymtab,
+                                     Kind, Deterministic, Thin))
+    return std::move(E);
+
+  return std::make_unique<SmallVectorMemoryBuffer>(
+      std::move(ArchiveBufferVector), /*RequiresNullTerminator=*/false);
+}
+
+} // namespace llvm