MFC r309124:

Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0.  Also completely revamp the build system for
clang, llvm, lldb and their related tools.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.

Relnotes:	yes

MFC r309147:

Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):

  [PPC] Set SP after loading data from stack frame, if no red zone is
  present

  Follow-up to r280705: Make sure that the SP is only restored after
  all data is loaded from the stack frame, if there is no red zone.

  This completes the fix for
  https://llvm.org/bugs/show_bug.cgi?id=26519.

  Differential Revision: https://reviews.llvm.org/D24466

Reported by:    Mark Millard
PR:             214433

MFC r309149:

Pull in r283060 from upstream llvm trunk (by Hal Finkel):

  [PowerPC] Refactor soft-float support, and enable PPC64 soft float

  This change enables soft-float for PowerPC64, and also makes
  soft-float disable all vector instruction sets for both 32-bit and
  64-bit modes. This latter part is necessary because the PPC backend
  canonicalizes many Altivec vector types to floating-point types, and
  so soft-float breaks scalarization support for many operations. Both
  for embedded targets and for operating-system kernels desiring
  soft-float support, it seems reasonable that disabling hardware
  floating-point also disables vector instructions (embedded targets
  without hardware floating point support are unlikely to have Altivec,
  etc. and operating system kernels desiring not to use floating-point
  registers to lower syscall cost are unlikely to want to use vector
  registers either). If someone needs this to work, we'll need to
  change the fact that we promote many Altivec operations to act on
  v4f32. To make it possible to disable Altivec when soft-float is
  enabled, hardware floating-point support needs to be expressed as a
  positive feature, like the others, and not a negative feature,
  because target features cannot have dependencies on the disabling of
  some other feature. So +soft-float has now become -hard-float.

  Fixes PR26970.

Pull in r283061 from upstream clang trunk (by Hal Finkel):

  [PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float

  Enable soft-float support on PPC64, as the backend now supports it.
  Also, the backend now uses -hard-float instead of +soft-float, so set
  the target features accordingly.

  Fixes PR26970.

Reported by:	Mark Millard
PR:		214433

MFC r309212:

Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.

MFC r309262:

Fix packaging for clang, lldb and lld 3.9.0

During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.

Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package

Reviewed by:	gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666

MFC r309656:

During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp.  This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.

Reported by:	Mark Millard
PR:		214902

MFC r309835:

Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.

Reported by:	https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/

MFC r310194:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>

Relnotes:	yes

1 files changed, 586 insertions, 0 deletions

diff --git a/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryReader.cpp b/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryReader.cpp
new file mode 100644
index 0000000..a17de5b
--- /dev/null
+++ b/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryReader.cpp
@@ -0,0 +1,586 @@
+//===- lib/ReaderWriter/MachO/MachONormalizedFileBinaryReader.cpp ---------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+///
+/// \file For mach-o object files, this implementation converts from
+/// mach-o on-disk binary format to in-memory normalized mach-o.
+///
+///                 +---------------+
+///                 | binary mach-o |
+///                 +---------------+
+///                        |
+///                        |
+///                        v
+///                  +------------+
+///                  | normalized |
+///                  +------------+
+
+#include "MachONormalizedFile.h"
+#include "ArchHandler.h"
+#include "MachONormalizedFileBinaryUtils.h"
+#include "lld/Core/Error.h"
+#include "lld/Core/LLVM.h"
+#include "lld/Core/SharedLibraryFile.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Object/MachO.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileOutputBuffer.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MachO.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include <functional>
+#include <system_error>
+
+using namespace llvm::MachO;
+using llvm::object::ExportEntry;
+using llvm::object::MachOObjectFile;
+
+namespace lld {
+namespace mach_o {
+namespace normalized {
+
+// Utility to call a lambda expression on each load command.
+static llvm::Error forEachLoadCommand(
+    StringRef lcRange, unsigned lcCount, bool isBig, bool is64,
+    std::function<bool(uint32_t cmd, uint32_t size, const char *lc)> func) {
+  const char* p = lcRange.begin();
+  for (unsigned i=0; i < lcCount; ++i) {
+    const load_command *lc = reinterpret_cast<const load_command*>(p);
+    load_command lcCopy;
+    const load_command *slc = lc;
+    if (isBig != llvm::sys::IsBigEndianHost) {
+      memcpy(&lcCopy, lc, sizeof(load_command));
+      swapStruct(lcCopy);
+      slc = &lcCopy;
+    }
+    if ( (p + slc->cmdsize) > lcRange.end() )
+      return llvm::make_error<GenericError>("Load command exceeds range");
+
+    if (func(slc->cmd, slc->cmdsize, p))
+      return llvm::Error();
+
+    p += slc->cmdsize;
+  }
+
+  return llvm::Error();
+}
+
+static std::error_code appendRelocations(Relocations &relocs, StringRef buffer,
+                                         bool bigEndian,
+                                         uint32_t reloff, uint32_t nreloc) {
+  if ((reloff + nreloc*8) > buffer.size())
+    return make_error_code(llvm::errc::executable_format_error);
+  const any_relocation_info* relocsArray =
+            reinterpret_cast<const any_relocation_info*>(buffer.begin()+reloff);
+
+  for(uint32_t i=0; i < nreloc; ++i) {
+    relocs.push_back(unpackRelocation(relocsArray[i], bigEndian));
+  }
+  return std::error_code();
+}
+
+static std::error_code
+appendIndirectSymbols(IndirectSymbols &isyms, StringRef buffer, bool isBig,
+                      uint32_t istOffset, uint32_t istCount,
+                      uint32_t startIndex, uint32_t count) {
+  if ((istOffset + istCount*4) > buffer.size())
+    return make_error_code(llvm::errc::executable_format_error);
+  if (startIndex+count  > istCount)
+    return make_error_code(llvm::errc::executable_format_error);
+  const uint8_t *indirectSymbolArray = (const uint8_t *)buffer.data();
+
+  for(uint32_t i=0; i < count; ++i) {
+    isyms.push_back(read32(
+        indirectSymbolArray + (startIndex + i) * sizeof(uint32_t), isBig));
+  }
+  return std::error_code();
+}
+
+
+template <typename T> static T readBigEndian(T t) {
+  if (llvm::sys::IsLittleEndianHost)
+    llvm::sys::swapByteOrder(t);
+  return t;
+}
+
+
+static bool isMachOHeader(const mach_header *mh, bool &is64, bool &isBig) {
+  switch (read32(&mh->magic, false)) {
+  case llvm::MachO::MH_MAGIC:
+    is64 = false;
+    isBig = false;
+    return true;
+  case llvm::MachO::MH_MAGIC_64:
+    is64 = true;
+    isBig = false;
+    return true;
+  case llvm::MachO::MH_CIGAM:
+    is64 = false;
+    isBig = true;
+    return true;
+  case llvm::MachO::MH_CIGAM_64:
+    is64 = true;
+    isBig = true;
+    return true;
+  default:
+    return false;
+  }
+}
+
+
+bool isThinObjectFile(StringRef path, MachOLinkingContext::Arch &arch) {
+  // Try opening and mapping file at path.
+  ErrorOr<std::unique_ptr<MemoryBuffer>> b = MemoryBuffer::getFileOrSTDIN(path);
+  if (b.getError())
+    return false;
+
+  // If file length < 32 it is too small to be mach-o object file.
+  StringRef fileBuffer = b->get()->getBuffer();
+  if (fileBuffer.size() < 32)
+    return false;
+
+  // If file buffer does not start with MH_MAGIC (and variants), not obj file.
+  const mach_header *mh = reinterpret_cast<const mach_header *>(
+                                                            fileBuffer.begin());
+  bool is64, isBig;
+  if (!isMachOHeader(mh, is64, isBig))
+    return false;
+
+  // If not MH_OBJECT, not object file.
+  if (read32(&mh->filetype, isBig) != MH_OBJECT)
+    return false;
+
+  // Lookup up arch from cpu/subtype pair.
+  arch = MachOLinkingContext::archFromCpuType(
+      read32(&mh->cputype, isBig),
+      read32(&mh->cpusubtype, isBig));
+  return true;
+}
+
+bool sliceFromFatFile(MemoryBufferRef mb, MachOLinkingContext::Arch arch,
+                      uint32_t &offset, uint32_t &size) {
+  const char *start = mb.getBufferStart();
+  const llvm::MachO::fat_header *fh =
+      reinterpret_cast<const llvm::MachO::fat_header *>(start);
+  if (readBigEndian(fh->magic) != llvm::MachO::FAT_MAGIC)
+    return false;
+  uint32_t nfat_arch = readBigEndian(fh->nfat_arch);
+  const fat_arch *fstart =
+      reinterpret_cast<const fat_arch *>(start + sizeof(fat_header));
+  const fat_arch *fend =
+      reinterpret_cast<const fat_arch *>(start + sizeof(fat_header) +
+                                         sizeof(fat_arch) * nfat_arch);
+  const uint32_t reqCpuType = MachOLinkingContext::cpuTypeFromArch(arch);
+  const uint32_t reqCpuSubtype = MachOLinkingContext::cpuSubtypeFromArch(arch);
+  for (const fat_arch *fa = fstart; fa < fend; ++fa) {
+    if ((readBigEndian(fa->cputype) == reqCpuType) &&
+        (readBigEndian(fa->cpusubtype) == reqCpuSubtype)) {
+      offset = readBigEndian(fa->offset);
+      size = readBigEndian(fa->size);
+      if ((offset + size) > mb.getBufferSize())
+        return false;
+      return true;
+    }
+  }
+  return false;
+}
+
+/// Reads a mach-o file and produces an in-memory normalized view.
+llvm::Expected<std::unique_ptr<NormalizedFile>>
+readBinary(std::unique_ptr<MemoryBuffer> &mb,
+           const MachOLinkingContext::Arch arch) {
+  // Make empty NormalizedFile.
+  std::unique_ptr<NormalizedFile> f(new NormalizedFile());
+
+  const char *start = mb->getBufferStart();
+  size_t objSize = mb->getBufferSize();
+  const mach_header *mh = reinterpret_cast<const mach_header *>(start);
+
+  uint32_t sliceOffset;
+  uint32_t sliceSize;
+  if (sliceFromFatFile(mb->getMemBufferRef(), arch, sliceOffset, sliceSize)) {
+    start = &start[sliceOffset];
+    objSize = sliceSize;
+    mh = reinterpret_cast<const mach_header *>(start);
+  }
+
+  // Determine endianness and pointer size for mach-o file.
+  bool is64, isBig;
+  if (!isMachOHeader(mh, is64, isBig))
+    return llvm::make_error<GenericError>("File is not a mach-o");
+
+  // Endian swap header, if needed.
+  mach_header headerCopy;
+  const mach_header *smh = mh;
+  if (isBig != llvm::sys::IsBigEndianHost) {
+    memcpy(&headerCopy, mh, sizeof(mach_header));
+    swapStruct(headerCopy);
+    smh = &headerCopy;
+  }
+
+  // Validate head and load commands fit in buffer.
+  const uint32_t lcCount = smh->ncmds;
+  const char *lcStart =
+      start + (is64 ? sizeof(mach_header_64) : sizeof(mach_header));
+  StringRef lcRange(lcStart, smh->sizeofcmds);
+  if (lcRange.end() > (start + objSize))
+    return llvm::make_error<GenericError>("Load commands exceed file size");
+
+  // Get architecture from mach_header.
+  f->arch = MachOLinkingContext::archFromCpuType(smh->cputype, smh->cpusubtype);
+  if (f->arch != arch) {
+    return llvm::make_error<GenericError>(
+                                  Twine("file is wrong architecture. Expected "
+                                  "(" + MachOLinkingContext::nameFromArch(arch)
+                                  + ") found ("
+                                  + MachOLinkingContext::nameFromArch(f->arch)
+                                  + ")" ));
+  }
+  // Copy file type and flags
+  f->fileType = HeaderFileType(smh->filetype);
+  f->flags = smh->flags;
+
+
+  // Pre-scan load commands looking for indirect symbol table.
+  uint32_t indirectSymbolTableOffset = 0;
+  uint32_t indirectSymbolTableCount = 0;
+  auto ec = forEachLoadCommand(lcRange, lcCount, isBig, is64,
+                               [&](uint32_t cmd, uint32_t size,
+                                   const char *lc) -> bool {
+    if (cmd == LC_DYSYMTAB) {
+      const dysymtab_command *d = reinterpret_cast<const dysymtab_command*>(lc);
+      indirectSymbolTableOffset = read32(&d->indirectsymoff, isBig);
+      indirectSymbolTableCount = read32(&d->nindirectsyms, isBig);
+      return true;
+    }
+    return false;
+  });
+  if (ec)
+    return std::move(ec);
+
+  // Walk load commands looking for segments/sections and the symbol table.
+  const data_in_code_entry *dataInCode = nullptr;
+  const dyld_info_command *dyldInfo = nullptr;
+  uint32_t dataInCodeSize = 0;
+  ec = forEachLoadCommand(lcRange, lcCount, isBig, is64,
+                    [&] (uint32_t cmd, uint32_t size, const char* lc) -> bool {
+    switch(cmd) {
+    case LC_SEGMENT_64:
+      if (is64) {
+        const segment_command_64 *seg =
+                              reinterpret_cast<const segment_command_64*>(lc);
+        const unsigned sectionCount = read32(&seg->nsects, isBig);
+        const section_64 *sects = reinterpret_cast<const section_64*>
+                                  (lc + sizeof(segment_command_64));
+        const unsigned lcSize = sizeof(segment_command_64)
+                                              + sectionCount*sizeof(section_64);
+        // Verify sections don't extend beyond end of segment load command.
+        if (lcSize > size)
+          return true;
+        for (unsigned i=0; i < sectionCount; ++i) {
+          const section_64 *sect = &sects[i];
+          Section section;
+          section.segmentName = getString16(sect->segname);
+          section.sectionName = getString16(sect->sectname);
+          section.type = (SectionType)(read32(&sect->flags, isBig) &
+                                       SECTION_TYPE);
+          section.attributes  = read32(&sect->flags, isBig) & SECTION_ATTRIBUTES;
+          section.alignment   = 1 << read32(&sect->align, isBig);
+          section.address     = read64(&sect->addr, isBig);
+          const uint8_t *content =
+            (const uint8_t *)start + read32(&sect->offset, isBig);
+          size_t contentSize = read64(&sect->size, isBig);
+          // Note: this assign() is copying the content bytes.  Ideally,
+          // we can use a custom allocator for vector to avoid the copy.
+          section.content = llvm::makeArrayRef(content, contentSize);
+          appendRelocations(section.relocations, mb->getBuffer(), isBig,
+                            read32(&sect->reloff, isBig),
+                            read32(&sect->nreloc, isBig));
+          if (section.type == S_NON_LAZY_SYMBOL_POINTERS) {
+            appendIndirectSymbols(section.indirectSymbols, mb->getBuffer(),
+                                  isBig,
+                                  indirectSymbolTableOffset,
+                                  indirectSymbolTableCount,
+                                  read32(&sect->reserved1, isBig),
+                                  contentSize/4);
+          }
+          f->sections.push_back(section);
+        }
+      }
+      break;
+    case LC_SEGMENT:
+      if (!is64) {
+        const segment_command *seg =
+                              reinterpret_cast<const segment_command*>(lc);
+        const unsigned sectionCount = read32(&seg->nsects, isBig);
+        const section *sects = reinterpret_cast<const section*>
+                                  (lc + sizeof(segment_command));
+        const unsigned lcSize = sizeof(segment_command)
+                                              + sectionCount*sizeof(section);
+        // Verify sections don't extend beyond end of segment load command.
+        if (lcSize > size)
+          return true;
+        for (unsigned i=0; i < sectionCount; ++i) {
+          const section *sect = &sects[i];
+          Section section;
+          section.segmentName = getString16(sect->segname);
+          section.sectionName = getString16(sect->sectname);
+          section.type = (SectionType)(read32(&sect->flags, isBig) &
+                                       SECTION_TYPE);
+          section.attributes =
+              read32((const uint8_t *)&sect->flags, isBig) & SECTION_ATTRIBUTES;
+          section.alignment   = 1 << read32(&sect->align, isBig);
+          section.address     = read32(&sect->addr, isBig);
+          const uint8_t *content =
+            (const uint8_t *)start + read32(&sect->offset, isBig);
+          size_t contentSize = read32(&sect->size, isBig);
+          // Note: this assign() is copying the content bytes.  Ideally,
+          // we can use a custom allocator for vector to avoid the copy.
+          section.content = llvm::makeArrayRef(content, contentSize);
+          appendRelocations(section.relocations, mb->getBuffer(), isBig,
+                            read32(&sect->reloff, isBig),
+                            read32(&sect->nreloc, isBig));
+          if (section.type == S_NON_LAZY_SYMBOL_POINTERS) {
+            appendIndirectSymbols(
+                section.indirectSymbols, mb->getBuffer(), isBig,
+                indirectSymbolTableOffset, indirectSymbolTableCount,
+                read32(&sect->reserved1, isBig), contentSize / 4);
+          }
+          f->sections.push_back(section);
+        }
+      }
+      break;
+    case LC_SYMTAB: {
+      const symtab_command *st = reinterpret_cast<const symtab_command*>(lc);
+      const char *strings = start + read32(&st->stroff, isBig);
+      const uint32_t strSize = read32(&st->strsize, isBig);
+      // Validate string pool and symbol table all in buffer.
+      if (read32((const uint8_t *)&st->stroff, isBig) +
+              read32((const uint8_t *)&st->strsize, isBig) >
+          objSize)
+        return true;
+      if (is64) {
+        const uint32_t symOffset = read32(&st->symoff, isBig);
+        const uint32_t symCount = read32(&st->nsyms, isBig);
+        if ( symOffset+(symCount*sizeof(nlist_64)) > objSize)
+          return true;
+        const nlist_64 *symbols =
+            reinterpret_cast<const nlist_64 *>(start + symOffset);
+        // Convert each nlist_64 to a lld::mach_o::normalized::Symbol.
+        for(uint32_t i=0; i < symCount; ++i) {
+          nlist_64 tempSym;
+          memcpy(&tempSym, &symbols[i], sizeof(nlist_64));
+          const nlist_64 *sin = &tempSym;
+          if (isBig != llvm::sys::IsBigEndianHost)
+            swapStruct(tempSym);
+          Symbol sout;
+          if (sin->n_strx > strSize)
+            return true;
+          sout.name  = &strings[sin->n_strx];
+          sout.type  = (NListType)(sin->n_type & N_TYPE);
+          sout.scope = (sin->n_type & (N_PEXT|N_EXT));
+          sout.sect  = sin->n_sect;
+          sout.desc  = sin->n_desc;
+          sout.value = sin->n_value;
+          if (sout.type == N_UNDF)
+            f->undefinedSymbols.push_back(sout);
+          else if (sin->n_type & N_EXT)
+            f->globalSymbols.push_back(sout);
+          else
+            f->localSymbols.push_back(sout);
+        }
+      } else {
+        const uint32_t symOffset = read32(&st->symoff, isBig);
+        const uint32_t symCount = read32(&st->nsyms, isBig);
+        if ( symOffset+(symCount*sizeof(nlist)) > objSize)
+          return true;
+        const nlist *symbols =
+            reinterpret_cast<const nlist *>(start + symOffset);
+        // Convert each nlist to a lld::mach_o::normalized::Symbol.
+        for(uint32_t i=0; i < symCount; ++i) {
+          const nlist *sin = &symbols[i];
+          nlist tempSym;
+          if (isBig != llvm::sys::IsBigEndianHost) {
+            tempSym = *sin; swapStruct(tempSym); sin = &tempSym;
+          }
+          Symbol sout;
+          if (sin->n_strx > strSize)
+            return true;
+          sout.name  = &strings[sin->n_strx];
+          sout.type  = (NListType)(sin->n_type & N_TYPE);
+          sout.scope = (sin->n_type & (N_PEXT|N_EXT));
+          sout.sect  = sin->n_sect;
+          sout.desc  = sin->n_desc;
+          sout.value = sin->n_value;
+          if (sout.type == N_UNDF)
+            f->undefinedSymbols.push_back(sout);
+          else if (sout.scope == (SymbolScope)N_EXT)
+            f->globalSymbols.push_back(sout);
+          else
+            f->localSymbols.push_back(sout);
+        }
+      }
+      }
+      break;
+    case LC_ID_DYLIB: {
+      const dylib_command *dl = reinterpret_cast<const dylib_command*>(lc);
+      f->installName = lc + read32(&dl->dylib.name, isBig);
+      f->currentVersion = read32(&dl->dylib.current_version, isBig);
+      f->compatVersion = read32(&dl->dylib.compatibility_version, isBig);
+      }
+      break;
+    case LC_DATA_IN_CODE: {
+      const linkedit_data_command *ldc =
+                            reinterpret_cast<const linkedit_data_command*>(lc);
+      dataInCode = reinterpret_cast<const data_in_code_entry *>(
+          start + read32(&ldc->dataoff, isBig));
+      dataInCodeSize = read32(&ldc->datasize, isBig);
+      }
+      break;
+    case LC_LOAD_DYLIB:
+    case LC_LOAD_WEAK_DYLIB:
+    case LC_REEXPORT_DYLIB:
+    case LC_LOAD_UPWARD_DYLIB: {
+      const dylib_command *dl = reinterpret_cast<const dylib_command*>(lc);
+      DependentDylib entry;
+      entry.path = lc + read32(&dl->dylib.name, isBig);
+      entry.kind = LoadCommandType(cmd);
+      entry.compatVersion = read32(&dl->dylib.compatibility_version, isBig);
+      entry.currentVersion = read32(&dl->dylib.current_version, isBig);
+      f->dependentDylibs.push_back(entry);
+     }
+      break;
+    case LC_RPATH: {
+      const rpath_command *rpc = reinterpret_cast<const rpath_command *>(lc);
+      f->rpaths.push_back(lc + read32(&rpc->path, isBig));
+     }
+      break;
+    case LC_DYLD_INFO:
+    case LC_DYLD_INFO_ONLY:
+      dyldInfo = reinterpret_cast<const dyld_info_command*>(lc);
+      break;
+    case LC_VERSION_MIN_MACOSX:
+    case LC_VERSION_MIN_IPHONEOS:
+    case LC_VERSION_MIN_WATCHOS:
+    case LC_VERSION_MIN_TVOS:
+      // If we are emitting an object file, then we may take the load command
+      // kind from these commands and pass it on to the output
+      // file.
+      f->minOSVersionKind = (LoadCommandType)cmd;
+      break;
+    }
+    return false;
+  });
+  if (ec)
+    return std::move(ec);
+
+  if (dataInCode) {
+    // Convert on-disk data_in_code_entry array to DataInCode vector.
+    for (unsigned i=0; i < dataInCodeSize/sizeof(data_in_code_entry); ++i) {
+      DataInCode entry;
+      entry.offset = read32(&dataInCode[i].offset, isBig);
+      entry.length = read16(&dataInCode[i].length, isBig);
+      entry.kind =
+          (DataRegionType)read16((const uint8_t *)&dataInCode[i].kind, isBig);
+      f->dataInCode.push_back(entry);
+    }
+  }
+
+  if (dyldInfo) {
+    // If any exports, extract and add to normalized exportInfo vector.
+    if (dyldInfo->export_size) {
+      const uint8_t *trieStart = reinterpret_cast<const uint8_t*>(start +
+                                                          dyldInfo->export_off);
+      ArrayRef<uint8_t> trie(trieStart, dyldInfo->export_size);
+      for (const ExportEntry &trieExport : MachOObjectFile::exports(trie)) {
+        Export normExport;
+        normExport.name = trieExport.name().copy(f->ownedAllocations);
+        normExport.offset = trieExport.address();
+        normExport.kind = ExportSymbolKind(trieExport.flags() & EXPORT_SYMBOL_FLAGS_KIND_MASK);
+        normExport.flags = trieExport.flags() & ~EXPORT_SYMBOL_FLAGS_KIND_MASK;
+        normExport.otherOffset = trieExport.other();
+        if (!trieExport.otherName().empty())
+          normExport.otherName = trieExport.otherName().copy(f->ownedAllocations);
+        f->exportInfo.push_back(normExport);
+      }
+    }
+  }
+
+  return std::move(f);
+}
+
+class MachOObjectReader : public Reader {
+public:
+  MachOObjectReader(MachOLinkingContext &ctx) : _ctx(ctx) {}
+
+  bool canParse(file_magic magic, MemoryBufferRef mb) const override {
+    return (magic == llvm::sys::fs::file_magic::macho_object &&
+            mb.getBufferSize() > 32);
+  }
+
+  ErrorOr<std::unique_ptr<File>>
+  loadFile(std::unique_ptr<MemoryBuffer> mb,
+           const Registry &registry) const override {
+    std::unique_ptr<File> ret =
+        llvm::make_unique<MachOFile>(std::move(mb), &_ctx);
+    return std::move(ret);
+  }
+
+private:
+  MachOLinkingContext &_ctx;
+};
+
+class MachODylibReader : public Reader {
+public:
+  MachODylibReader(MachOLinkingContext &ctx) : _ctx(ctx) {}
+
+  bool canParse(file_magic magic, MemoryBufferRef mb) const override {
+    switch (magic) {
+    case llvm::sys::fs::file_magic::macho_dynamically_linked_shared_lib:
+    case llvm::sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
+      return mb.getBufferSize() > 32;
+    default:
+      return false;
+    }
+  }
+
+  ErrorOr<std::unique_ptr<File>>
+  loadFile(std::unique_ptr<MemoryBuffer> mb,
+           const Registry &registry) const override {
+    std::unique_ptr<File> ret =
+        llvm::make_unique<MachODylibFile>(std::move(mb), &_ctx);
+    return std::move(ret);
+  }
+
+private:
+  MachOLinkingContext &_ctx;
+};
+
+} // namespace normalized
+} // namespace mach_o
+
+void Registry::addSupportMachOObjects(MachOLinkingContext &ctx) {
+  MachOLinkingContext::Arch arch = ctx.arch();
+  add(std::unique_ptr<Reader>(new mach_o::normalized::MachOObjectReader(ctx)));
+  add(std::unique_ptr<Reader>(new mach_o::normalized::MachODylibReader(ctx)));
+  addKindTable(Reference::KindNamespace::mach_o, ctx.archHandler().kindArch(),
+               ctx.archHandler().kindStrings());
+  add(std::unique_ptr<YamlIOTaggedDocumentHandler>(
+                           new mach_o::MachOYamlIOTaggedDocumentHandler(arch)));
+}
+
+
+} // namespace lld