Reapply part of r237975, "Fix Clang -Wmissing-override warning", except for DIContext...
[oota-llvm.git] / lib / ExecutionEngine / RuntimeDyld / RuntimeDyldMachO.cpp
index 71b914d49056f2334090717158173efa0de17b5f..d4a680d749a163e95a2aa33a727ea6965b0187ab 100644 (file)
 //===----------------------------------------------------------------------===//
 
 #include "RuntimeDyldMachO.h"
+#include "Targets/RuntimeDyldMachOAArch64.h"
+#include "Targets/RuntimeDyldMachOARM.h"
+#include "Targets/RuntimeDyldMachOI386.h"
+#include "Targets/RuntimeDyldMachOX86_64.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
-#include "ObjectImageCommon.h"
-#include "JITRegistrar.h"
+
 using namespace llvm;
 using namespace llvm::object;
 
 #define DEBUG_TYPE "dyld"
 
-namespace llvm {
-
-class MachOObjectImage : public ObjectImageCommon {
-private:
-  typedef SmallVector<uint64_t, 1> SectionAddrList;
-  SectionAddrList OldSectionAddrList;
-
-protected:
-  bool is64;
-  bool Registered;
-
-private:
-  void initOldAddress() {
-    MachOObjectFile *objf = static_cast<MachOObjectFile *>(ObjFile.get());
-    // Unfortunately we need to do this, since there's information encoded
-    // in the original addr of the section that we could not otherwise
-    // recover. The reason for this is that symbols do not actually store
-    // their file offset, but only their vmaddr. This means that in order
-    // to locate the symbol correctly in the object file, we need to know
-    // where the original start of the section was (including any padding,
-    // etc).
-    for (section_iterator i = objf->section_begin(), e = objf->section_end();
-         i != e; ++i) {
-      uint64_t Addr;
-      i->getAddress(Addr);
-      OldSectionAddrList[i->getRawDataRefImpl().d.a] = Addr;
-    }
-  }
+namespace {
 
+class LoadedMachOObjectInfo
+    : public RuntimeDyld::LoadedObjectInfoHelper<LoadedMachOObjectInfo> {
 public:
-  MachOObjectImage(ObjectBuffer *Input, bool is64)
-      : ObjectImageCommon(Input),
-        OldSectionAddrList(ObjFile->section_end()->getRawDataRefImpl().d.a, 0),
-        is64(is64), Registered(false) {
-    initOldAddress();
-  }
+  LoadedMachOObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
+                        unsigned EndIdx)
+      : LoadedObjectInfoHelper(RTDyld, BeginIdx, EndIdx) {}
 
-  MachOObjectImage(std::unique_ptr<object::ObjectFile> Input, bool is64)
-      : ObjectImageCommon(std::move(Input)),
-        OldSectionAddrList(ObjFile->section_end()->getRawDataRefImpl().d.a, 0),
-        is64(is64), Registered(false) {
-    initOldAddress();
+  OwningBinary<ObjectFile>
+  getObjectForDebug(const ObjectFile &Obj) const override {
+    return OwningBinary<ObjectFile>();
   }
+};
 
-  virtual ~MachOObjectImage() {
-    if (Registered)
-      deregisterWithDebugger();
-  }
+}
 
-  // Subclasses can override these methods to update the image with loaded
-  // addresses for sections and common symbols
-  virtual void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) {
-    MachOObjectFile *objf = static_cast<MachOObjectFile *>(ObjFile.get());
-    char *data =
-        const_cast<char *>(objf->getSectionPointer(Sec.getRawDataRefImpl()));
+namespace llvm {
 
-    uint64_t oldAddr = OldSectionAddrList[Sec.getRawDataRefImpl().d.a];
+int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const {
+  unsigned NumBytes = 1 << RE.Size;
+  uint8_t *Src = Sections[RE.SectionID].Address + RE.Offset;
 
-    if (is64) {
-      ((MachO::section_64 *)data)->addr = Addr;
-    } else {
-      ((MachO::section *)data)->addr = Addr;
-    }
+  return static_cast<int64_t>(readBytesUnaligned(Src, NumBytes));
+}
+
+RelocationValueRef RuntimeDyldMachO::getRelocationValueRef(
+    const ObjectFile &BaseTObj, const relocation_iterator &RI,
+    const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) {
 
-    for (symbol_iterator i = objf->symbol_begin(), e = objf->symbol_end();
-         i != e; ++i) {
-      section_iterator symSec(objf->section_end());
-      (*i).getSection(symSec);
-      if (*symSec == Sec) {
-        uint64_t symAddr;
-        (*i).getAddress(symAddr);
-        updateSymbolAddress(*i, symAddr + Addr - oldAddr);
-      }
+  const MachOObjectFile &Obj =
+      static_cast<const MachOObjectFile &>(BaseTObj);
+  MachO::any_relocation_info RelInfo =
+      Obj.getRelocation(RI->getRawDataRefImpl());
+  RelocationValueRef Value;
+
+  bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);
+  if (IsExternal) {
+    symbol_iterator Symbol = RI->getSymbol();
+    StringRef TargetName;
+    Symbol->getName(TargetName);
+    RTDyldSymbolTable::const_iterator SI =
+      GlobalSymbolTable.find(TargetName.data());
+    if (SI != GlobalSymbolTable.end()) {
+      const auto &SymInfo = SI->second;
+      Value.SectionID = SymInfo.getSectionID();
+      Value.Offset = SymInfo.getOffset() + RE.Addend;
+    } else {
+      Value.SymbolName = TargetName.data();
+      Value.Offset = RE.Addend;
     }
+  } else {
+    SectionRef Sec = Obj.getAnyRelocationSection(RelInfo);
+    bool IsCode = Sec.isText();
+    Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
+    uint64_t Addr = Sec.getAddress();
+    Value.Offset = RE.Addend - Addr;
   }
 
-  uint64_t getOldSectionAddr(const SectionRef &Sec) const {
-    return OldSectionAddrList[Sec.getRawDataRefImpl().d.a];
-  }
+  return Value;
+}
 
-  virtual void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) {
-    char *data = const_cast<char *>(
-        reinterpret_cast<const char *>(Sym.getRawDataRefImpl().p));
-    if (is64)
-      ((MachO::nlist_64 *)data)->n_value = Addr;
-    else
-      ((MachO::nlist *)data)->n_value = Addr;
+void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
+                                            const ObjectFile &BaseTObj,
+                                            const relocation_iterator &RI,
+                                            unsigned OffsetToNextPC) {
+  const MachOObjectFile &Obj =
+      static_cast<const MachOObjectFile &>(BaseTObj);
+  MachO::any_relocation_info RelInfo =
+      Obj.getRelocation(RI->getRawDataRefImpl());
+
+  bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
+  if (IsPCRel) {
+    uint64_t RelocAddr = 0;
+    RI->getAddress(RelocAddr);
+    Value.Offset += RelocAddr + OffsetToNextPC;
   }
+}
+
+void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
+                                               uint64_t Value) const {
+  const SectionEntry &Section = Sections[RE.SectionID];
+  uint8_t *LocalAddress = Section.Address + RE.Offset;
+  uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
+
+  dbgs() << "resolveRelocation Section: " << RE.SectionID
+         << " LocalAddress: " << format("%p", LocalAddress)
+         << " FinalAddress: " << format("0x%016" PRIx64, FinalAddress)
+         << " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend
+         << " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType
+         << " Size: " << (1 << RE.Size) << "\n";
+}
 
-  virtual void registerWithDebugger() {
-    JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
-    Registered = true;
+section_iterator
+RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,
+                                      uint64_t Addr) {
+  section_iterator SI = Obj.section_begin();
+  section_iterator SE = Obj.section_end();
+
+  for (; SI != SE; ++SI) {
+    uint64_t SAddr = SI->getAddress();
+    uint64_t SSize = SI->getSize();
+    if ((Addr >= SAddr) && (Addr < SAddr + SSize))
+      return SI;
   }
 
-  virtual void deregisterWithDebugger() {
-    JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
+  return SE;
+}
+
+
+// Populate __pointers section.
+void RuntimeDyldMachO::populateIndirectSymbolPointersSection(
+                                                    const MachOObjectFile &Obj,
+                                                    const SectionRef &PTSection,
+                                                    unsigned PTSectionID) {
+  assert(!Obj.is64Bit() &&
+         "Pointer table section not supported in 64-bit MachO.");
+
+  MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
+  MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
+  uint32_t PTSectionSize = Sec32.size;
+  unsigned FirstIndirectSymbol = Sec32.reserved1;
+  const unsigned PTEntrySize = 4;
+  unsigned NumPTEntries = PTSectionSize / PTEntrySize;
+  unsigned PTEntryOffset = 0;
+
+  assert((PTSectionSize % PTEntrySize) == 0 &&
+         "Pointers section does not contain a whole number of stubs?");
+
+  DEBUG(dbgs() << "Populating pointer table section "
+               << Sections[PTSectionID].Name
+               << ", Section ID " << PTSectionID << ", "
+               << NumPTEntries << " entries, " << PTEntrySize
+               << " bytes each:\n");
+
+  for (unsigned i = 0; i < NumPTEntries; ++i) {
+    unsigned SymbolIndex =
+      Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
+    symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
+    StringRef IndirectSymbolName;
+    SI->getName(IndirectSymbolName);
+    DEBUG(dbgs() << "  " << IndirectSymbolName << ": index " << SymbolIndex
+          << ", PT offset: " << PTEntryOffset << "\n");
+    RelocationEntry RE(PTSectionID, PTEntryOffset,
+                       MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
+    addRelocationForSymbol(RE, IndirectSymbolName);
+    PTEntryOffset += PTEntrySize;
   }
-};
+}
 
-ObjectImage *RuntimeDyldMachO::createObjectImage(ObjectBuffer *Buffer) {
-  uint32_t magic = *((uint32_t *)Buffer->getBufferStart());
-  bool is64 = (magic == MachO::MH_MAGIC_64);
-  assert((magic == MachO::MH_MAGIC_64 || magic == MachO::MH_MAGIC) &&
-         "Unrecognized Macho Magic");
-  return new MachOObjectImage(Buffer, is64);
+bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile &Obj) const {
+  return Obj.isMachO();
 }
 
-ObjectImage *RuntimeDyldMachO::createObjectImageFromFile(
-    std::unique_ptr<object::ObjectFile> ObjFile) {
-  if (!ObjFile)
-    return nullptr;
+template <typename Impl>
+void RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &Obj,
+                                                  ObjSectionToIDMap &SectionMap) {
+  unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
+  unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
+  unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
 
-  MemoryBuffer *Buffer =
-      MemoryBuffer::getMemBuffer(ObjFile->getData(), "", false);
+  for (const auto &Section : Obj.sections()) {
+    StringRef Name;
+    Section.getName(Name);
 
-  uint32_t magic = *((uint32_t *)Buffer->getBufferStart());
-  bool is64 = (magic == MachO::MH_MAGIC_64);
-  assert((magic == MachO::MH_MAGIC_64 || magic == MachO::MH_MAGIC) &&
-         "Unrecognized Macho Magic");
-  return new MachOObjectImage(std::move(ObjFile), is64);
+    // Force emission of the __text, __eh_frame, and __gcc_except_tab sections
+    // if they're present. Otherwise call down to the impl to handle other
+    // sections that have already been emitted.
+    if (Name == "__text")
+      TextSID = findOrEmitSection(Obj, Section, true, SectionMap);
+    else if (Name == "__eh_frame")
+      EHFrameSID = findOrEmitSection(Obj, Section, false, SectionMap);
+    else if (Name == "__gcc_except_tab")
+      ExceptTabSID = findOrEmitSection(Obj, Section, true, SectionMap);
+    else {
+      auto I = SectionMap.find(Section);
+      if (I != SectionMap.end())
+        impl().finalizeSection(Obj, I->second, Section);
+    }
+  }
+  UnregisteredEHFrameSections.push_back(
+    EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
 }
 
-static unsigned char *processFDE(unsigned char *P, intptr_t DeltaForText,
-                                 intptr_t DeltaForEH) {
+template <typename Impl>
+unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(unsigned char *P,
+                                                          int64_t DeltaForText,
+                                                          int64_t DeltaForEH) {
+  typedef typename Impl::TargetPtrT TargetPtrT;
+
   DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
                << ", Delta for EH: " << DeltaForEH << "\n");
-  uint32_t Length = *((uint32_t *)P);
+  uint32_t Length = readBytesUnaligned(P, 4);
   P += 4;
   unsigned char *Ret = P + Length;
-  uint32_t Offset = *((uint32_t *)P);
+  uint32_t Offset = readBytesUnaligned(P, 4);
   if (Offset == 0) // is a CIE
     return Ret;
 
   P += 4;
-  intptr_t FDELocation = *((intptr_t *)P);
-  intptr_t NewLocation = FDELocation - DeltaForText;
-  *((intptr_t *)P) = NewLocation;
-  P += sizeof(intptr_t);
+  TargetPtrT FDELocation = readBytesUnaligned(P, sizeof(TargetPtrT));
+  TargetPtrT NewLocation = FDELocation - DeltaForText;
+  writeBytesUnaligned(NewLocation, P, sizeof(TargetPtrT));
+
+  P += sizeof(TargetPtrT);
 
   // Skip the FDE address range
-  P += sizeof(intptr_t);
+  P += sizeof(TargetPtrT);
 
   uint8_t Augmentationsize = *P;
   P += 1;
   if (Augmentationsize != 0) {
-    intptr_t LSDA = *((intptr_t *)P);
-    intptr_t NewLSDA = LSDA - DeltaForEH;
-    *((intptr_t *)P) = NewLSDA;
+    TargetPtrT LSDA = readBytesUnaligned(P, sizeof(TargetPtrT));
+    TargetPtrT NewLSDA = LSDA - DeltaForEH;
+    writeBytesUnaligned(NewLSDA, P, sizeof(TargetPtrT));
   }
 
   return Ret;
 }
 
-static intptr_t computeDelta(SectionEntry *A, SectionEntry *B) {
-  intptr_t ObjDistance = A->ObjAddress - B->ObjAddress;
-  intptr_t MemDistance = A->LoadAddress - B->LoadAddress;
+static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {
+  int64_t ObjDistance =
+    static_cast<int64_t>(A->ObjAddress) - static_cast<int64_t>(B->ObjAddress);
+  int64_t MemDistance = A->LoadAddress - B->LoadAddress;
   return ObjDistance - MemDistance;
 }
 
-void RuntimeDyldMachO::registerEHFrames() {
+template <typename Impl>
+void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
 
-  if (!MemMgr)
-    return;
   for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
     EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
     if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
@@ -195,8 +265,8 @@ void RuntimeDyldMachO::registerEHFrames() {
     if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
       ExceptTab = &Sections[SectionInfo.ExceptTabSID];
 
-    intptr_t DeltaForText = computeDelta(Text, EHFrame);
-    intptr_t DeltaForEH = 0;
+    int64_t DeltaForText = computeDelta(Text, EHFrame);
+    int64_t DeltaForEH = 0;
     if (ExceptTab)
       DeltaForEH = computeDelta(ExceptTab, EHFrame);
 
@@ -206,621 +276,37 @@ void RuntimeDyldMachO::registerEHFrames() {
       P = processFDE(P, DeltaForText, DeltaForEH);
     } while (P != End);
 
-    MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
-                             EHFrame->Size);
+    MemMgr.registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
+                            EHFrame->Size);
   }
   UnregisteredEHFrameSections.clear();
 }
 
-void RuntimeDyldMachO::finalizeLoad(ObjectImage &ObjImg,
-                                    ObjSectionToIDMap &SectionMap) {
-  unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
-  unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
-  unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
-  ObjSectionToIDMap::iterator i, e;
-  for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
-    const SectionRef &Section = i->first;
-    StringRef Name;
-    Section.getName(Name);
-    if (Name == "__eh_frame")
-      EHFrameSID = i->second;
-    else if (Name == "__text")
-      TextSID = i->second;
-    else if (Name == "__gcc_except_tab")
-      ExceptTabSID = i->second;
-    else if (Name == "__jump_table")
-      populateJumpTable(cast<MachOObjectFile>(*ObjImg.getObjectFile()),
-                        Section, i->second);
-    else if (Name == "__pointers")
-      populatePointersSection(cast<MachOObjectFile>(*ObjImg.getObjectFile()),
-                              Section, i->second);
-  }
-  UnregisteredEHFrameSections.push_back(
-      EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
-}
-
-// The target location for the relocation is described by RE.SectionID and
-// RE.Offset.  RE.SectionID can be used to find the SectionEntry.  Each
-// SectionEntry has three members describing its location.
-// SectionEntry::Address is the address at which the section has been loaded
-// into memory in the current (host) process.  SectionEntry::LoadAddress is the
-// address that the section will have in the target process.
-// SectionEntry::ObjAddress is the address of the bits for this section in the
-// original emitted object image (also in the current address space).
-//
-// Relocations will be applied as if the section were loaded at
-// SectionEntry::LoadAddress, but they will be applied at an address based
-// on SectionEntry::Address.  SectionEntry::ObjAddress will be used to refer to
-// Target memory contents if they are required for value calculations.
-//
-// The Value parameter here is the load address of the symbol for the
-// relocation to be applied.  For relocations which refer to symbols in the
-// current object Value will be the LoadAddress of the section in which
-// the symbol resides (RE.Addend provides additional information about the
-// symbol location).  For external symbols, Value will be the address of the
-// symbol in the target address space.
-void RuntimeDyldMachO::resolveRelocation(const RelocationEntry &RE,
-                                         uint64_t Value) {
-  DEBUG (
-    const SectionEntry &Section = Sections[RE.SectionID];
-    uint8_t* LocalAddress = Section.Address + RE.Offset;
-    uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
-
-    dbgs() << "resolveRelocation Section: " << RE.SectionID
-           << " LocalAddress: " << format("%p", LocalAddress)
-           << " FinalAddress: " << format("%p", FinalAddress)
-           << " Value: " << format("%p", Value)
-           << " Addend: " << RE.Addend
-           << " isPCRel: " << RE.IsPCRel
-           << " MachoType: " << RE.RelType
-           << " Size: " << (1 << RE.Size) << "\n";
-  );
-
-  // This just dispatches to the proper target specific routine.
+std::unique_ptr<RuntimeDyldMachO>
+RuntimeDyldMachO::create(Triple::ArchType Arch,
+                         RuntimeDyld::MemoryManager &MemMgr,
+                         RuntimeDyld::SymbolResolver &Resolver) {
   switch (Arch) {
   default:
-    llvm_unreachable("Unsupported CPU type!");
-  case Triple::x86_64:
-    resolveX86_64Relocation(RE, Value);
-    break;
-  case Triple::x86:
-    resolveI386Relocation(RE, Value);
-    break;
-  case Triple::arm: // Fall through.
-  case Triple::thumb:
-    resolveARMRelocation(RE, Value);
+    llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
     break;
+  case Triple::arm:
+    return make_unique<RuntimeDyldMachOARM>(MemMgr, Resolver);
   case Triple::aarch64:
-  case Triple::arm64:
-    resolveAArch64Relocation(RE, Value);
-    break;
-  }
-}
-
-bool RuntimeDyldMachO::resolveI386Relocation(const RelocationEntry &RE,
-                                             uint64_t Value) {
-  const SectionEntry &Section = Sections[RE.SectionID];
-  uint8_t* LocalAddress = Section.Address + RE.Offset;
-
-  if (RE.IsPCRel) {
-    uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
-    Value -= FinalAddress + 4; // see MachOX86_64::resolveRelocation.
-  }
-
-  switch (RE.RelType) {
-    default:
-      llvm_unreachable("Invalid relocation type!");
-    case MachO::GENERIC_RELOC_VANILLA:
-      return applyRelocationValue(LocalAddress, Value + RE.Addend,
-                                  1 << RE.Size);
-    case MachO::GENERIC_RELOC_SECTDIFF:
-    case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
-      uint64_t SectionABase = Sections[RE.Sections.SectionA].LoadAddress;
-      uint64_t SectionBBase = Sections[RE.Sections.SectionB].LoadAddress;
-      assert((Value == SectionABase || Value == SectionBBase) &&
-             "Unexpected SECTDIFF relocation value.");
-      Value = SectionABase - SectionBBase + RE.Addend;
-      return applyRelocationValue(LocalAddress, Value, 1 << RE.Size);
-    }
-    case MachO::GENERIC_RELOC_PB_LA_PTR:
-      return Error("Relocation type not implemented yet!");
-  }
-}
-
-bool RuntimeDyldMachO::resolveX86_64Relocation(const RelocationEntry &RE,
-                                               uint64_t Value) {
-  const SectionEntry &Section = Sections[RE.SectionID];
-  uint8_t* LocalAddress = Section.Address + RE.Offset;
-
-  // If the relocation is PC-relative, the value to be encoded is the
-  // pointer difference.
-  if (RE.IsPCRel) {
-    // FIXME: It seems this value needs to be adjusted by 4 for an effective PC
-    // address. Is that expected? Only for branches, perhaps?
-    uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
-    Value -= FinalAddress + 4; // see MachOX86_64::resolveRelocation.
-  }
-
-  switch (RE.RelType) {
-  default:
-    llvm_unreachable("Invalid relocation type!");
-  case MachO::X86_64_RELOC_SIGNED_1:
-  case MachO::X86_64_RELOC_SIGNED_2:
-  case MachO::X86_64_RELOC_SIGNED_4:
-  case MachO::X86_64_RELOC_SIGNED:
-  case MachO::X86_64_RELOC_UNSIGNED:
-  case MachO::X86_64_RELOC_BRANCH:
-    return applyRelocationValue(LocalAddress, Value + RE.Addend, 1 << RE.Size);
-  case MachO::X86_64_RELOC_GOT_LOAD:
-  case MachO::X86_64_RELOC_GOT:
-  case MachO::X86_64_RELOC_SUBTRACTOR:
-  case MachO::X86_64_RELOC_TLV:
-    return Error("Relocation type not implemented yet!");
-  }
-}
-
-bool RuntimeDyldMachO::resolveARMRelocation(const RelocationEntry &RE,
-                                            uint64_t Value) {
-  const SectionEntry &Section = Sections[RE.SectionID];
-  uint8_t* LocalAddress = Section.Address + RE.Offset;
-
-  // If the relocation is PC-relative, the value to be encoded is the
-  // pointer difference.
-  if (RE.IsPCRel) {
-    uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
-    Value -= FinalAddress;
-    // ARM PCRel relocations have an effective-PC offset of two instructions
-    // (four bytes in Thumb mode, 8 bytes in ARM mode).
-    // FIXME: For now, assume ARM mode.
-    Value -= 8;
-  }
-
-  switch (RE.RelType) {
-  default:
-    llvm_unreachable("Invalid relocation type!");
-  case MachO::ARM_RELOC_VANILLA:
-    return applyRelocationValue(LocalAddress, Value, 1 << RE.Size);
-  case MachO::ARM_RELOC_BR24: {
-    // Mask the value into the target address. We know instructions are
-    // 32-bit aligned, so we can do it all at once.
-    uint32_t *p = (uint32_t *)LocalAddress;
-    // The low two bits of the value are not encoded.
-    Value >>= 2;
-    // Mask the value to 24 bits.
-    uint64_t FinalValue = Value & 0xffffff;
-    // Check for overflow.
-    if (Value != FinalValue)
-      return Error("ARM BR24 relocation out of range.");
-    // FIXME: If the destination is a Thumb function (and the instruction
-    // is a non-predicated BL instruction), we need to change it to a BLX
-    // instruction instead.
-
-    // Insert the value into the instruction.
-    *p = (*p & ~0xffffff) | FinalValue;
-    break;
-  }
-  case MachO::ARM_THUMB_RELOC_BR22:
-  case MachO::ARM_THUMB_32BIT_BRANCH:
-  case MachO::ARM_RELOC_HALF:
-  case MachO::ARM_RELOC_HALF_SECTDIFF:
-  case MachO::ARM_RELOC_PAIR:
-  case MachO::ARM_RELOC_SECTDIFF:
-  case MachO::ARM_RELOC_LOCAL_SECTDIFF:
-  case MachO::ARM_RELOC_PB_LA_PTR:
-    return Error("Relocation type not implemented yet!");
-  }
-  return false;
-}
-
-bool RuntimeDyldMachO::resolveAArch64Relocation(const RelocationEntry &RE,
-                                                uint64_t Value) {
-  const SectionEntry &Section = Sections[RE.SectionID];
-  uint8_t* LocalAddress = Section.Address + RE.Offset;
-
-  // If the relocation is PC-relative, the value to be encoded is the
-  // pointer difference.
-  if (RE.IsPCRel) {
-    uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
-    Value -= FinalAddress;
-  }
-
-  switch (RE.RelType) {
-  default:
-    llvm_unreachable("Invalid relocation type!");
-  case MachO::ARM64_RELOC_UNSIGNED:
-    return applyRelocationValue(LocalAddress, Value, 1 << RE.Size);
-  case MachO::ARM64_RELOC_BRANCH26: {
-    // Mask the value into the target address. We know instructions are
-    // 32-bit aligned, so we can do it all at once.
-    uint32_t *p = (uint32_t *)LocalAddress;
-    // The low two bits of the value are not encoded.
-    Value >>= 2;
-    // Mask the value to 26 bits.
-    uint64_t FinalValue = Value & 0x3ffffff;
-    // Check for overflow.
-    if (FinalValue != Value)
-      return Error("ARM64 BRANCH26 relocation out of range.");
-    // Insert the value into the instruction.
-    *p = (*p & ~0x3ffffff) | FinalValue;
-    break;
-  }
-  case MachO::ARM64_RELOC_SUBTRACTOR:
-  case MachO::ARM64_RELOC_PAGE21:
-  case MachO::ARM64_RELOC_PAGEOFF12:
-  case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
-  case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12:
-  case MachO::ARM64_RELOC_POINTER_TO_GOT:
-  case MachO::ARM64_RELOC_TLVP_LOAD_PAGE21:
-  case MachO::ARM64_RELOC_TLVP_LOAD_PAGEOFF12:
-  case MachO::ARM64_RELOC_ADDEND:
-    return Error("Relocation type not implemented yet!");
-  }
-  return false;
-}
-
-void RuntimeDyldMachO::populateJumpTable(MachOObjectFile &Obj,
-                                         const SectionRef &JTSection,
-                                         unsigned JTSectionID) {
-  assert(!Obj.is64Bit() &&
-         "__jump_table section not supported in 64-bit MachO.");
-
-  MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
-  MachO::section Sec32 = Obj.getSection(JTSection.getRawDataRefImpl());
-  uint32_t JTSectionSize = Sec32.size;
-  unsigned FirstIndirectSymbol = Sec32.reserved1;
-  unsigned JTEntrySize = Sec32.reserved2;
-  unsigned NumJTEntries = JTSectionSize / JTEntrySize;
-  uint8_t* JTSectionAddr = getSectionAddress(JTSectionID);
-  unsigned JTEntryOffset = 0;
-
-  assert((JTSectionSize % JTEntrySize) == 0 &&
-         "Jump-table section does not contain a whole number of stubs?");
-
-  for (unsigned i = 0; i < NumJTEntries; ++i) {
-    unsigned SymbolIndex =
-      Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
-    symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
-    StringRef IndirectSymbolName;
-    SI->getName(IndirectSymbolName);
-    uint8_t* JTEntryAddr = JTSectionAddr + JTEntryOffset;
-    createStubFunction(JTEntryAddr);
-    RelocationEntry RE(JTSectionID, JTEntryOffset + 1,
-                       MachO::GENERIC_RELOC_VANILLA, 0, true, 2);
-    addRelocationForSymbol(RE, IndirectSymbolName);
-    JTEntryOffset += JTEntrySize;
-  }
-}
-
-void RuntimeDyldMachO::populatePointersSection(MachOObjectFile &Obj,
-                                               const SectionRef &PTSection,
-                                               unsigned PTSectionID) {
-  assert(!Obj.is64Bit() &&
-         "__pointers section not supported in 64-bit MachO.");
-
-  MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
-  MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
-  uint32_t PTSectionSize = Sec32.size;
-  unsigned FirstIndirectSymbol = Sec32.reserved1;
-  const unsigned PTEntrySize = 4;
-  unsigned NumPTEntries = PTSectionSize / PTEntrySize;
-  unsigned PTEntryOffset = 0;
-
-  assert((PTSectionSize % PTEntrySize) == 0 &&
-         "Pointers section does not contain a whole number of stubs?");
-
-  DEBUG(dbgs() << "Populating __pointers, Section ID " << PTSectionID
-               << ", " << NumPTEntries << " entries, "
-               << PTEntrySize << " bytes each:\n");
-
-  for (unsigned i = 0; i < NumPTEntries; ++i) {
-    unsigned SymbolIndex =
-      Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
-    symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
-    StringRef IndirectSymbolName;
-    SI->getName(IndirectSymbolName);
-    DEBUG(dbgs() << "  " << IndirectSymbolName << ": index " << SymbolIndex
-          << ", PT offset: " << PTEntryOffset << "\n");
-    RelocationEntry RE(PTSectionID, PTEntryOffset,
-                       MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
-    addRelocationForSymbol(RE, IndirectSymbolName);
-    PTEntryOffset += PTEntrySize;
-  }
-}
-
-
-section_iterator getSectionByAddress(const MachOObjectFile &Obj,
-                                     uint64_t Addr) {
-  section_iterator SI = Obj.section_begin();
-  section_iterator SE = Obj.section_end();
-
-  for (; SI != SE; ++SI) {
-    uint64_t SAddr, SSize;
-    SI->getAddress(SAddr);
-    SI->getSize(SSize);
-    if ((Addr >= SAddr) && (Addr < SAddr + SSize))
-      return SI;
-  }
-
-  return SE;
-}
-
-relocation_iterator RuntimeDyldMachO::processSECTDIFFRelocation(
-                                            unsigned SectionID,
-                                            relocation_iterator RelI,
-                                            ObjectImage &Obj,
-                                            ObjSectionToIDMap &ObjSectionToID) {
-  const MachOObjectFile *MachO =
-    static_cast<const MachOObjectFile*>(Obj.getObjectFile());
-  MachO::any_relocation_info RE =
-    MachO->getRelocation(RelI->getRawDataRefImpl());
-
-  SectionEntry &Section = Sections[SectionID];
-  uint32_t RelocType = MachO->getAnyRelocationType(RE);
-  bool IsPCRel = MachO->getAnyRelocationPCRel(RE);
-  unsigned Size = MachO->getAnyRelocationLength(RE);
-  uint64_t Offset;
-  RelI->getOffset(Offset);
-  uint8_t *LocalAddress = Section.Address + Offset;
-  unsigned NumBytes = 1 << Size;
-  int64_t Addend = 0;
-  memcpy(&Addend, LocalAddress, NumBytes);
-
-  ++RelI;
-  MachO::any_relocation_info RE2 =
-    MachO->getRelocation(RelI->getRawDataRefImpl());
-
-  uint32_t AddrA = MachO->getScatteredRelocationValue(RE);
-  section_iterator SAI = getSectionByAddress(*MachO, AddrA);
-  assert(SAI != MachO->section_end() && "Can't find section for address A");
-  uint64_t SectionABase;
-  SAI->getAddress(SectionABase);
-  uint64_t SectionAOffset = AddrA - SectionABase;
-  SectionRef SectionA = *SAI;
-  bool IsCode;
-  SectionA.isText(IsCode);
-  uint32_t SectionAID = findOrEmitSection(Obj, SectionA, IsCode,
-                                          ObjSectionToID);
-
-  uint32_t AddrB = MachO->getScatteredRelocationValue(RE2);
-  section_iterator SBI = getSectionByAddress(*MachO, AddrB);
-  assert(SBI != MachO->section_end() && "Can't find section for address B");
-  uint64_t SectionBBase;
-  SBI->getAddress(SectionBBase);
-  uint64_t SectionBOffset = AddrB - SectionBBase;
-  SectionRef SectionB = *SBI;
-  uint32_t SectionBID = findOrEmitSection(Obj, SectionB, IsCode,
-                                          ObjSectionToID);
-
-  if (Addend != AddrA - AddrB)
-    Error("Unexpected SECTDIFF relocation addend.");
-
-  DEBUG(dbgs() << "Found SECTDIFF: AddrA: " << AddrA << ", AddrB: " << AddrB
-               << ", Addend: " << Addend << ", SectionA ID: "
-               << SectionAID << ", SectionAOffset: " << SectionAOffset
-               << ", SectionB ID: " << SectionBID << ", SectionBOffset: "
-               << SectionBOffset << "\n");
-  RelocationEntry R(SectionID, Offset, RelocType, 0,
-                    SectionAID, SectionAOffset, SectionBID, SectionBOffset,
-                    IsPCRel, Size);
-
-  addRelocationForSection(R, SectionAID);
-  addRelocationForSection(R, SectionBID);
-
-  return ++RelI;
-}
-
-relocation_iterator RuntimeDyldMachO::processI386ScatteredVANILLA(
-                                            unsigned SectionID,
-                                            relocation_iterator RelI,
-                                            ObjectImage &Obj,
-                                            ObjSectionToIDMap &ObjSectionToID) {
-  const MachOObjectFile *MachO =
-    static_cast<const MachOObjectFile*>(Obj.getObjectFile());
-  MachO::any_relocation_info RE =
-    MachO->getRelocation(RelI->getRawDataRefImpl());
-
-  SectionEntry &Section = Sections[SectionID];
-  uint32_t RelocType = MachO->getAnyRelocationType(RE);
-  bool IsPCRel = MachO->getAnyRelocationPCRel(RE);
-  unsigned Size = MachO->getAnyRelocationLength(RE);
-  uint64_t Offset;
-  RelI->getOffset(Offset);
-  uint8_t *LocalAddress = Section.Address + Offset;
-  unsigned NumBytes = 1 << Size;
-  int64_t Addend = 0;
-  memcpy(&Addend, LocalAddress, NumBytes);
-
-  unsigned SymbolBaseAddr = MachO->getScatteredRelocationValue(RE);
-  section_iterator TargetSI = getSectionByAddress(*MachO, SymbolBaseAddr);
-  assert(TargetSI != MachO->section_end() && "Can't find section for symbol");
-  uint64_t SectionBaseAddr;
-  TargetSI->getAddress(SectionBaseAddr);
-  SectionRef TargetSection = *TargetSI;
-  bool IsCode;
-  TargetSection.isText(IsCode);
-  uint32_t TargetSectionID = findOrEmitSection(Obj, TargetSection, IsCode,
-                                               ObjSectionToID);
-
-  Addend -= SectionBaseAddr;
-  RelocationEntry R(SectionID, Offset, RelocType, Addend,
-                    IsPCRel, Size);
-
-  addRelocationForSection(R, TargetSectionID);
-
-  return ++RelI;
-}
-
-relocation_iterator RuntimeDyldMachO::processRelocationRef(
-    unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
-    ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
-    StubMap &Stubs) {
-  const ObjectFile *OF = Obj.getObjectFile();
-  const MachOObjectImage &MachOObj = *static_cast<MachOObjectImage *>(&Obj);
-  const MachOObjectFile *MachO = static_cast<const MachOObjectFile *>(OF);
-  MachO::any_relocation_info RE =
-      MachO->getRelocation(RelI->getRawDataRefImpl());
-
-  uint32_t RelType = MachO->getAnyRelocationType(RE);
-
-  // FIXME: Properly handle scattered relocations.
-  //        Special case the couple of scattered relocations that we know how
-  //        to handle: SECTDIFF relocations, and scattered VANILLA relocations
-  //        on I386.
-  //        For all other scattered relocations, just bail out and hope for the
-  //        best, since the offsets computed by scattered relocations have often
-  //        been optimisticaly filled in by the compiler. This will fail
-  //        horribly where the relocations *do* need to be applied, but that was
-  //        already the case.
-  if (MachO->isRelocationScattered(RE)) {
-    if (RelType == MachO::GENERIC_RELOC_SECTDIFF ||
-        RelType == MachO::GENERIC_RELOC_LOCAL_SECTDIFF)
-      return processSECTDIFFRelocation(SectionID, RelI, Obj, ObjSectionToID);
-    else if (Arch == Triple::x86 && RelType == MachO::GENERIC_RELOC_VANILLA)
-      return processI386ScatteredVANILLA(SectionID, RelI, Obj, ObjSectionToID);
-    else
-      return ++RelI;
-  }
-
-  RelocationValueRef Value;
-  SectionEntry &Section = Sections[SectionID];
-
-  bool IsExtern = MachO->getPlainRelocationExternal(RE);
-  bool IsPCRel = MachO->getAnyRelocationPCRel(RE);
-  unsigned Size = MachO->getAnyRelocationLength(RE);
-  uint64_t Offset;
-  RelI->getOffset(Offset);
-  uint8_t *LocalAddress = Section.Address + Offset;
-  unsigned NumBytes = 1 << Size;
-  uint64_t Addend = 0;
-  memcpy(&Addend, LocalAddress, NumBytes);
-
-  if (IsExtern) {
-    // Obtain the symbol name which is referenced in the relocation
-    symbol_iterator Symbol = RelI->getSymbol();
-    StringRef TargetName;
-    Symbol->getName(TargetName);
-    // First search for the symbol in the local symbol table
-    SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
-    if (lsi != Symbols.end()) {
-      Value.SectionID = lsi->second.first;
-      Value.Addend = lsi->second.second + Addend;
-    } else {
-      // Search for the symbol in the global symbol table
-      SymbolTableMap::const_iterator gsi =
-          GlobalSymbolTable.find(TargetName.data());
-      if (gsi != GlobalSymbolTable.end()) {
-        Value.SectionID = gsi->second.first;
-        Value.Addend = gsi->second.second + Addend;
-      } else {
-        Value.SymbolName = TargetName.data();
-        Value.Addend = Addend;
-      }
-    }
-
-    // Addends for external, PC-rel relocations on i386 point back to the zero
-    // offset. Calculate the final offset from the relocation target instead.
-    // This allows us to use the same logic for both external and internal
-    // relocations in resolveI386RelocationRef.
-    if (Arch == Triple::x86 && IsPCRel) {
-      uint64_t RelocAddr = 0;
-      RelI->getAddress(RelocAddr);
-      Value.Addend += RelocAddr + 4;
-    }
-
-  } else {
-    SectionRef Sec = MachO->getRelocationSection(RE);
-    bool IsCode = false;
-    Sec.isText(IsCode);
-    Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
-    uint64_t Addr = MachOObj.getOldSectionAddr(Sec);
-    DEBUG(dbgs() << "\nAddr: " << Addr << "\nAddend: " << Addend);
-    Value.Addend = Addend - Addr;
-    if (IsPCRel)
-      Value.Addend += Offset + NumBytes;
-  }
-
-  if (Arch == Triple::x86_64 && (RelType == MachO::X86_64_RELOC_GOT ||
-                                 RelType == MachO::X86_64_RELOC_GOT_LOAD)) {
-    assert(IsPCRel);
-    assert(Size == 2);
-
-    // FIXME: Teach the generic code above not to prematurely conflate
-    //        relocation addends and symbol offsets.
-    Value.Addend -= Addend;
-    StubMap::const_iterator i = Stubs.find(Value);
-    uint8_t *Addr;
-    if (i != Stubs.end()) {
-      Addr = Section.Address + i->second;
-    } else {
-      Stubs[Value] = Section.StubOffset;
-      uint8_t *GOTEntry = Section.Address + Section.StubOffset;
-      RelocationEntry GOTRE(SectionID, Section.StubOffset,
-                            MachO::X86_64_RELOC_UNSIGNED, Value.Addend, false,
-                            3);
-      if (Value.SymbolName)
-        addRelocationForSymbol(GOTRE, Value.SymbolName);
-      else
-        addRelocationForSection(GOTRE, Value.SectionID);
-      Section.StubOffset += 8;
-      Addr = GOTEntry;
-    }
-    RelocationEntry TargetRE(SectionID, Offset,
-                             MachO::X86_64_RELOC_UNSIGNED, Addend, true,
-                             2);
-    resolveRelocation(TargetRE, (uint64_t)Addr);
-  } else if (Arch == Triple::arm && (RelType & 0xf) == MachO::ARM_RELOC_BR24) {
-    // This is an ARM branch relocation, need to use a stub function.
-
-    //  Look up for existing stub.
-    StubMap::const_iterator i = Stubs.find(Value);
-    uint8_t *Addr;
-    if (i != Stubs.end()) {
-      Addr = Section.Address + i->second;
-    } else {
-      // Create a new stub function.
-      Stubs[Value] = Section.StubOffset;
-      uint8_t *StubTargetAddr =
-          createStubFunction(Section.Address + Section.StubOffset);
-      RelocationEntry StubRE(SectionID, StubTargetAddr - Section.Address,
-                             MachO::GENERIC_RELOC_VANILLA, Value.Addend);
-      if (Value.SymbolName)
-        addRelocationForSymbol(StubRE, Value.SymbolName);
-      else
-        addRelocationForSection(StubRE, Value.SectionID);
-      Addr = Section.Address + Section.StubOffset;
-      Section.StubOffset += getMaxStubSize();
-    }
-    RelocationEntry TargetRE(Value.SectionID, Offset, RelType, 0, IsPCRel,
-                             Size);
-    resolveRelocation(TargetRE, (uint64_t)Addr);
-  } else {
-    RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, IsPCRel, Size);
-    if (Value.SymbolName)
-      addRelocationForSymbol(RE, Value.SymbolName);
-    else
-      addRelocationForSection(RE, Value.SectionID);
+    return make_unique<RuntimeDyldMachOAArch64>(MemMgr, Resolver);
+  case Triple::x86:
+    return make_unique<RuntimeDyldMachOI386>(MemMgr, Resolver);
+  case Triple::x86_64:
+    return make_unique<RuntimeDyldMachOX86_64>(MemMgr, Resolver);
   }
-  return ++RelI;
-}
-
-bool
-RuntimeDyldMachO::isCompatibleFormat(const ObjectBuffer *InputBuffer) const {
-  if (InputBuffer->getBufferSize() < 4)
-    return false;
-  StringRef Magic(InputBuffer->getBufferStart(), 4);
-  if (Magic == "\xFE\xED\xFA\xCE")
-    return true;
-  if (Magic == "\xCE\xFA\xED\xFE")
-    return true;
-  if (Magic == "\xFE\xED\xFA\xCF")
-    return true;
-  if (Magic == "\xCF\xFA\xED\xFE")
-    return true;
-  return false;
 }
 
-bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile *Obj) const {
-  return Obj->isMachO();
+std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
+RuntimeDyldMachO::loadObject(const object::ObjectFile &O) {
+  unsigned SectionStartIdx, SectionEndIdx;
+  std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
+  return llvm::make_unique<LoadedMachOObjectInfo>(*this, SectionStartIdx,
+                                                  SectionEndIdx);
 }
 
 } // end namespace llvm