Revert r153694. It was causing failures in the buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153701 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 1046 insertions, 753 deletions

diff --git a/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h b/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h
index a68949aa41..118b0d42ee 100644
--- a/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h
+++ b/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h
@@ -34,12 +34,12 @@ public:
 
   uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
                                unsigned SectionID) {
-    return JMM->allocateSpace(Size, Alignment);
+    return JMM->allocateDataSection(Size, Alignment, SectionID);
   }
 
   uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
                                unsigned SectionID) {
-    return JMM->allocateSpace(Size, Alignment);
+    return JMM->allocateCodeSection(Size, Alignment, SectionID);
   }
 
   virtual void *getPointerToNamedFunction(const std::string &Name,
@@ -47,6 +47,40 @@ public:
     return JMM->getPointerToNamedFunction(Name, AbortOnFailure);
   }
 
+  // Allocate ActualSize bytes, or more, for the named function. Return
+  // a pointer to the allocated memory and update Size to reflect how much
+  // memory was acutally allocated.
+  uint8_t *startFunctionBody(const char *Name, uintptr_t &Size) {
+    // FIXME: This should really reference the MCAsmInfo to get the global
+    //        prefix.
+    if (Name[0] == '_') ++Name;
+    Function *F = M->getFunction(Name);
+    // Some ObjC names have a prefixed \01 in the IR. If we failed to find
+    // the symbol and it's of the ObjC conventions (starts with "-" or
+    // "+"), try prepending a \01 and see if we can find it that way.
+    if (!F && (Name[0] == '-' || Name[0] == '+'))
+      F = M->getFunction((Twine("\1") + Name).str());
+    assert(F && "No matching function in JIT IR Module!");
+    return JMM->startFunctionBody(F, Size);
+  }
+
+  // Mark the end of the function, including how much of the allocated
+  // memory was actually used.
+  void endFunctionBody(const char *Name, uint8_t *FunctionStart,
+                       uint8_t *FunctionEnd) {
+    // FIXME: This should really reference the MCAsmInfo to get the global
+    //        prefix.
+    if (Name[0] == '_') ++Name;
+    Function *F = M->getFunction(Name);
+    // Some ObjC names have a prefixed \01 in the IR. If we failed to find
+    // the symbol and it's of the ObjC conventions (starts with "-" or
+    // "+"), try prepending a \01 and see if we can find it that way.
+    if (!F && (Name[0] == '-' || Name[0] == '+'))
+      F = M->getFunction((Twine("\1") + Name).str());
+    assert(F && "No matching function in JIT IR Module!");
+    JMM->endFunctionBody(F, FunctionStart, FunctionEnd);
+  }
+
 };
 
 } // End llvm namespace
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 7a2b858611..2896c2d556 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -26,290 +26,45 @@ RuntimeDyldImpl::~RuntimeDyldImpl() {}
 
 namespace llvm {
 
-namespace {
-  // Helper for extensive error checking in debug builds.
-  error_code Check(error_code Err) {
-    if (Err) {
-      report_fatal_error(Err.message());
-    }
-    return Err;
-  }
-} // end anonymous namespace
+void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress,
+                                      uint8_t *EndAddress) {
+  // FIXME: DEPRECATED in favor of by-section allocation.
+  // Allocate memory for the function via the memory manager.
+  uintptr_t Size = EndAddress - StartAddress + 1;
+  uintptr_t AllocSize = Size;
+  uint8_t *Mem = MemMgr->startFunctionBody(Name.data(), AllocSize);
+  assert(Size >= (uint64_t)(EndAddress - StartAddress + 1) &&
+         "Memory manager failed to allocate enough memory!");
+  // Copy the function payload into the memory block.
+  memcpy(Mem, StartAddress, Size);
+  MemMgr->endFunctionBody(Name.data(), Mem, Mem + Size);
+  // Remember where we put it.
+  unsigned SectionID = Sections.size();
+  Sections.push_back(sys::MemoryBlock(Mem, Size));
 
+  // Default the assigned address for this symbol to wherever this
+  // allocated it.
+  SymbolTable[Name] = SymbolLoc(SectionID, 0);
+  DEBUG(dbgs() << "    allocated to [" << Mem << ", " << Mem + Size << "]\n");
+}
 
 // Resolve the relocations for all symbols we currently know about.
 void RuntimeDyldImpl::resolveRelocations() {
-  // First, resolve relocations assotiated with external symbols.
-  resolveSymbols();
-
   // Just iterate over the sections we have and resolve all the relocations
   // in them. Gross overkill, but it gets the job done.
   for (int i = 0, e = Sections.size(); i != e; ++i) {
-    reassignSectionAddress(i, Sections[i].LoadAddress);
+    reassignSectionAddress(i, SectionLoadAddress[i]);
   }
 }
 
 void RuntimeDyldImpl::mapSectionAddress(void *LocalAddress,
                                         uint64_t TargetAddress) {
-  for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
-    if (Sections[i].Address == LocalAddress) {
-      reassignSectionAddress(i, TargetAddress);
-      return;
-    }
-  }
-  llvm_unreachable("Attempting to remap address of unknown section!");
-}
-
-bool RuntimeDyldImpl::loadObject(const MemoryBuffer *InputBuffer) {
-  // FIXME: ObjectFile don't modify MemoryBuffer.
-  //        It should use const MemoryBuffer as parameter.
-  ObjectFile *obj
-    = ObjectFile::createObjectFile(const_cast<MemoryBuffer*>(InputBuffer));
-
-  Arch = (Triple::ArchType)obj->getArch();
-
-  LocalSymbolMap LocalSymbols;     // Functions and data symbols from the
-                                   // object file.
-  ObjSectionToIDMap LocalSections; // Used sections from the object file
-
-  error_code err;
-  // Parse symbols
-  DEBUG(dbgs() << "Parse symbols:\n");
-  for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols();
-       i != e; i.increment(err)) {
-    Check(err);
-    object::SymbolRef::Type SymType;
-    StringRef Name;
-    Check(i->getType(SymType));
-    Check(i->getName(Name));
-
-    if (SymType == object::SymbolRef::ST_Function ||
-        SymType == object::SymbolRef::ST_Data) {
-      uint64_t FileOffset;
-      uint32_t flags;
-      StringRef sData;
-      section_iterator si = obj->end_sections();
-      Check(i->getFileOffset(FileOffset));
-      Check(i->getFlags(flags));
-      Check(i->getSection(si));
-      if (si == obj->end_sections()) continue;
-      Check(si->getContents(sData));
-      const uint8_t* SymPtr = (const uint8_t*)InputBuffer->getBufferStart() +
-                              (uintptr_t)FileOffset;
-      uintptr_t SectOffset = (uintptr_t)(SymPtr - (const uint8_t*)sData.begin());
-      unsigned SectionID
-        = findOrEmitSection(*si,
-                          SymType == object::SymbolRef::ST_Function,
-                          LocalSections);
-      bool isGlobal = flags & SymbolRef::SF_Global;
-      LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset);
-      DEBUG(dbgs() << "\tFileOffset: " << format("%p", (uintptr_t)FileOffset)
-                   << " flags: " << flags
-                   << " SID: " << SectionID
-                   << " Offset: " << format("%p", SectOffset));
-      if (isGlobal)
-        SymbolTable[Name] = SymbolLoc(SectionID, SectOffset);
-    }
-    DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n");
-  }
-
-  // Parse and proccess relocations
-  DEBUG(dbgs() << "Parse relocations:\n");
-  for (section_iterator si = obj->begin_sections(),
-       se = obj->end_sections(); si != se; si.increment(err)) {
-    Check(err);
-    bool isFirstRelocation = true;
-    unsigned SectionID = 0;
-    StubMap Stubs;
-
-    for (relocation_iterator i = si->begin_relocations(),
-         e = si->end_relocations(); i != e; i.increment(err)) {
-      Check(err);
-
-      // If it's first relocation in this section, find its SectionID
-      if (isFirstRelocation) {
-        SectionID = findOrEmitSection(*si, true, LocalSections);
-        DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
-        isFirstRelocation = false;
-      }
-
-      ObjRelocationInfo RI;
-      RI.SectionID = SectionID;
-      Check(i->getAdditionalInfo(RI.AdditionalInfo));
-      Check(i->getOffset(RI.Offset));
-      Check(i->getSymbol(RI.Symbol));
-      Check(i->getType(RI.Type));
-
-      DEBUG(dbgs() << "\t\tAddend: " << RI.AdditionalInfo
-                   << " Offset: " << format("%p", (uintptr_t)RI.Offset)
-                   << " Type: " << (uint32_t)(RI.Type & 0xffffffffL)
-                   << "\n");
-      processRelocationRef(RI, *obj, LocalSections, LocalSymbols, Stubs);
-    }
-  }
-  return false;
-}
-
-unsigned RuntimeDyldImpl::emitSection(const SectionRef &Section,
-                                      bool IsCode) {
-
-  unsigned StubBufSize = 0,
-           StubSize = getMaxStubSize();
-  error_code err;
-  if (StubSize > 0) {
-    for (relocation_iterator i = Section.begin_relocations(),
-         e = Section.end_relocations(); i != e; i.increment(err))
-      StubBufSize += StubSize;
-  }
-  StringRef data;
-  uint64_t Alignment64;
-  Check(Section.getContents(data));
-  Check(Section.getAlignment(Alignment64));
-
-  unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
-  unsigned DataSize = data.size();
-  unsigned Allocate = DataSize + StubBufSize;
-  unsigned SectionID = Sections.size();
-  const char *pData = data.data();
-  uint8_t *Addr = IsCode
-    ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID)
-    : MemMgr->allocateDataSection(Allocate, Alignment, SectionID);
-
-  memcpy(Addr, pData, DataSize);
-  DEBUG(dbgs() << "emitSection SectionID: " << SectionID
-               << " obj addr: " << format("%p", pData)
-               << " new addr: " << format("%p", Addr)
-               << " DataSize: " << DataSize
-               << " StubBufSize: " << StubBufSize
-               << " Allocate: " << Allocate
-               << "\n");
-  Sections.push_back(SectionEntry(Addr, Allocate, DataSize,(uintptr_t)pData));
-  return SectionID;
-}
-
-unsigned RuntimeDyldImpl::findOrEmitSection(const SectionRef &Section,
-                                            bool IsCode,
-                                            ObjSectionToIDMap &LocalSections) {
-
-  unsigned SectionID = 0;
-  ObjSectionToIDMap::iterator i = LocalSections.find(Section);
-  if (i != LocalSections.end())
-    SectionID = i->second;
-  else {
-    SectionID = emitSection(Section, IsCode);
-    LocalSections[Section] = SectionID;
-  }
-  return SectionID;
-}
-
-void RuntimeDyldImpl::AddRelocation(const RelocationValueRef &Value,
-                                   unsigned SectionID, uintptr_t Offset,
-                                   uint32_t RelType) {
-  DEBUG(dbgs() << "AddRelocation SymNamePtr: " << format("%p", Value.SymbolName)
-               << " SID: " << Value.SectionID
-               << " Addend: " << format("%p", Value.Addend)
-               << " Offset: " << format("%p", Offset)
-               << " RelType: " << format("%x", RelType)
-               << "\n");
-
-  if (Value.SymbolName == 0) {
-    Relocations[Value.SectionID].push_back(RelocationEntry(
-      SectionID,
-      Offset,
-      RelType,
-      Value.Addend));
-  } else
-    SymbolRelocations[Value.SymbolName].push_back(RelocationEntry(
-      SectionID,
-      Offset,
-      RelType,
-      Value.Addend));
-}
-
-uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) {
-  // TODO: There is only ARM far stub now. We should add the Thumb stub,
-  // and stubs for branches Thumb - ARM and ARM - Thumb.
-  if (Arch == Triple::arm) {
-    uint32_t *StubAddr = (uint32_t*)Addr;
-    *StubAddr = 0xe51ff004; // ldr pc,<label>
-    return (uint8_t*)++StubAddr;
-  }
-  else
-    return Addr;
+  assert(SectionLocalMemToID.count(LocalAddress) &&
+         "Attempting to remap address of unknown section!");
+  unsigned SectionID = SectionLocalMemToID[LocalAddress];
+  reassignSectionAddress(SectionID, TargetAddress);
 }
 
-// Assign an address to a symbol name and resolve all the relocations
-// associated with it.
-void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
-                                             uint64_t Addr) {
-  // The address to use for relocation resolution is not
-  // the address of the local section buffer. We must be doing
-  // a remote execution environment of some sort. Re-apply any
-  // relocations referencing this section with the given address.
-  //
-  // Addr is a uint64_t because we can't assume the pointer width
-  // of the target is the same as that of the host. Just use a generic
-  // "big enough" type.
-  Sections[SectionID].LoadAddress = Addr;
-  DEBUG(dbgs() << "Resolving relocations Section #" << SectionID
-          << "\t" << format("%p", (uint8_t *)Addr)
-          << "\n");
-  resolveRelocationList(Relocations[SectionID], Addr);
-}
-
-void RuntimeDyldImpl::resolveRelocationEntry(const RelocationEntry &RE,
-                                             uint64_t Value) {
-    uint8_t *Target = Sections[RE.SectionID].Address + RE.Offset;
-    DEBUG(dbgs() << "\tSectionID: " << RE.SectionID
-          << " + " << RE.Offset << " (" << format("%p", Target) << ")"
-          << " Data: " << RE.Data
-          << " Addend: " << RE.Addend
-          << "\n");
-
-    resolveRelocation(Target, Sections[RE.SectionID].LoadAddress + RE.Offset,
-                      Value, RE.Data, RE.Addend);
-}
-
-void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
-                                            uint64_t Value) {
-  for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
-    resolveRelocationEntry(Relocs[i], Value);
-  }
-}
-
-// resolveSymbols - Resolve any relocations to the specified symbols if
-// we know where it lives.
-void RuntimeDyldImpl::resolveSymbols() {
-  StringMap<RelocationList>::iterator i = SymbolRelocations.begin(),
-                                      e = SymbolRelocations.end();
-  for (; i != e; i++) {
-    StringRef Name = i->first();
-    RelocationList &Relocs = i->second;
-    StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Name);
-    if (Loc == SymbolTable.end()) {
-      // This is an external symbol, try to get it address from
-      // MemoryManager.
-      uint8_t *Addr = (uint8_t*) MemMgr->getPointerToNamedFunction(Name.data(),
-                                                                   true);
-      DEBUG(dbgs() << "Resolving relocations Name: " << Name
-              << "\t" << format("%p", Addr)
-              << "\n");
-      resolveRelocationList(Relocs, (uintptr_t)Addr);
-    } else {
-      // Change the relocation to be section relative rather than symbol
-      // relative and move it to the resolved relocation list.
-      DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n");
-      for (int i = 0, e = Relocs.size(); i != e; ++i) {
-        RelocationEntry Entry = Relocs[i];
-        Entry.Addend += Loc->second.second;
-        Relocations[Loc->second.first].push_back(Entry);
-      }
-      Relocs.clear();
-    }
-  }
-}
-
-
 //===----------------------------------------------------------------------===//
 // RuntimeDyld class implementation
 RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index 9d46b21f59..e15b200c5e 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -25,58 +25,222 @@ using namespace llvm::object;
 
 namespace llvm {
 
+namespace {
 
-void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress,
-                                             uint64_t FinalAddress,
-                                             uint64_t Value,
-                                             uint32_t Type,
-                                             int64_t Addend) {
-  switch (Type) {
-  default:
-    llvm_unreachable("Relocation type not implemented yet!");
-  break;
+// FIXME: this function should probably not live here...
+//
+// Returns the name and address of an unrelocated symbol in an ELF section
+void getSymbolInfo(symbol_iterator Sym, uint64_t &Addr, StringRef &Name) {
+  //FIXME: error checking here required to catch corrupt ELF objects...
+  error_code Err = Sym->getName(Name);
+
+  uint64_t AddrInSection;
+  Err = Sym->getAddress(AddrInSection);
+
+  SectionRef empty_section;
+  section_iterator Section(empty_section);
+  Err = Sym->getSection(Section);
+
+  StringRef SectionContents;
+  Section->getContents(SectionContents);
+
+  Addr = reinterpret_cast<uint64_t>(SectionContents.data()) + AddrInSection;
+}
+
+}
+
+bool RuntimeDyldELF::loadObject(MemoryBuffer *InputBuffer) {
+  if (!isCompatibleFormat(InputBuffer))
+    return true;
+
+  OwningPtr<ObjectFile> Obj(ObjectFile::createELFObjectFile(InputBuffer));
+
+  Arch = Obj->getArch();
+
+  // Map address in the Object file image to function names
+  IntervalMap<uint64_t, StringRef>::Allocator A;
+  IntervalMap<uint64_t, StringRef> FuncMap(A);
+
+  // This is a bit of a hack.  The ObjectFile we've just loaded reports
+  // section addresses as 0 and doesn't provide access to the section
+  // offset (from which we could calculate the address.  Instead,
+  // we're storing the address when it comes up in the ST_Debug case
+  // below.
+  //
+  StringMap<uint64_t> DebugSymbolMap;
+
+  symbol_iterator SymEnd = Obj->end_symbols();
+  error_code Err;
+  for (symbol_iterator Sym = Obj->begin_symbols();
+       Sym != SymEnd; Sym.increment(Err)) {
+    SymbolRef::Type Type;
+    Sym->getType(Type);
+    if (Type == SymbolRef::ST_Function) {
+      StringRef Name;
+      uint64_t Addr;
+      getSymbolInfo(Sym, Addr, Name);
+
+      uint64_t Size;
+      Err = Sym->getSize(Size);
+
+      uint8_t *Start;
+      uint8_t *End;
+      Start = reinterpret_cast<uint8_t*>(Addr);
+      End   = reinterpret_cast<uint8_t*>(Addr + Size - 1);
+
+      extractFunction(Name, Start, End);
+      FuncMap.insert(Addr, Addr + Size - 1, Name);
+    } else if (Type == SymbolRef::ST_Debug) {
+      // This case helps us find section addresses
+      StringRef Name;
+      uint64_t Addr;
+      getSymbolInfo(Sym, Addr, Name);
+      DebugSymbolMap[Name] = Addr;
+    }
+  }
+
+  // Iterate through the relocations for this object
+  section_iterator SecEnd = Obj->end_sections();
+  for (section_iterator Sec = Obj->begin_sections();
+       Sec != SecEnd; Sec.increment(Err)) {
+    StringRef SecName;
+    uint64_t  SecAddr;
+    Sec->getName(SecName);
+    // Ignore sections that aren't in our map
+    if (DebugSymbolMap.find(SecName) == DebugSymbolMap.end()) {
+      continue;
+    }
+    SecAddr = DebugSymbolMap[SecName];
+    relocation_iterator RelEnd = Sec->end_relocations();
+    for (relocation_iterator Rel = Sec->begin_relocations();
+         Rel != RelEnd; Rel.increment(Err)) {
+      uint64_t RelOffset;
+      uint64_t RelType;
+      int64_t RelAddend;
+      SymbolRef RelSym;
+      StringRef SymName;
+      uint64_t SymAddr;
+      uint64_t SymOffset;
+
+      Rel->getAddress(RelOffset);
+      Rel->getType(RelType);
+      Rel->getAdditionalInfo(RelAddend);
+      Rel->getSymbol(RelSym);
+      RelSym.getName(SymName);
+      RelSym.getAddress(SymAddr);
+      RelSym.getFileOffset(SymOffset);
+
+      // If this relocation is inside a function, we want to store the
+      // function name and a function-relative offset
+      IntervalMap<uint64_t, StringRef>::iterator ContainingFunc
+        = FuncMap.find(SecAddr + RelOffset);
+      if (ContainingFunc.valid()) {
+        // Re-base the relocation to make it relative to the target function
+        RelOffset = (SecAddr + RelOffset) - ContainingFunc.start();
+        Relocations[SymName].push_back(RelocationEntry(ContainingFunc.value(),
+                                                       RelOffset,
+                                                       RelType,
+                                                       RelAddend,
+                                                       true));
+      } else {
+        Relocations[SymName].push_back(RelocationEntry(SecName,
+                                                       RelOffset,
+                                                       RelType,
+                                                       RelAddend,
+                                                       false));
+      }
+    }
+  }
+  return false;
+}
+
+void RuntimeDyldELF::resolveRelocations() {
+  // FIXME: deprecated. should be changed to use the by-section
+  // allocation and relocation scheme.
+
+  // Just iterate over the symbols in our symbol table and assign their
+  // addresses.
+  StringMap<SymbolLoc>::iterator i = SymbolTable.begin();
+  StringMap<SymbolLoc>::iterator e = SymbolTable.end();
+  for (;i != e; ++i) {
+    assert (i->getValue().second == 0 && "non-zero offset in by-function sym!");
+    reassignSymbolAddress(i->getKey(),
+                          (uint8_t*)Sections[i->getValue().first].base());
+  }
+}
+
+void RuntimeDyldELF::resolveX86_64Relocation(StringRef Name,
+                                             uint8_t *Addr,
+                                             const RelocationEntry &RE) {
+  uint8_t *TargetAddr;
+  if (RE.IsFunctionRelative) {
+    StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(RE.Target);
+    assert(Loc != SymbolTable.end() && "Function for relocation not found");
+    TargetAddr =
+      reinterpret_cast<uint8_t*>(Sections[Loc->second.first].base()) +
+      Loc->second.second + RE.Offset;
+  } else {
+    // FIXME: Get the address of the target section and add that to RE.Offset
+    llvm_unreachable("Non-function relocation not implemented yet!");
+  }
+
+  switch (RE.Type) {
+  default: llvm_unreachable("Relocation type not implemented yet!");
   case ELF::R_X86_64_64: {
-    uint64_t *Target = (uint64_t*)(LocalAddress);
-    *Target = Value + Addend;
+    uint8_t **Target = reinterpret_cast<uint8_t**>(TargetAddr);
+    *Target = Addr + RE.Addend;
     break;
   }
   case ELF::R_X86_64_32:
   case ELF::R_X86_64_32S: {
-    Value += Addend;
+    uint64_t Value = reinterpret_cast<uint64_t>(Addr) + RE.Addend;
     // FIXME: Handle the possibility of this assertion failing
-    assert((Type == ELF::R_X86_64_32 && !(Value & 0xFFFFFFFF00000000ULL)) ||
-           (Type == ELF::R_X86_64_32S &&
+    assert((RE.Type == ELF::R_X86_64_32 && !(Value & 0xFFFFFFFF00000000ULL)) ||
+           (RE.Type == ELF::R_X86_64_32S &&
             (Value & 0xFFFFFFFF00000000ULL) == 0xFFFFFFFF00000000ULL));
     uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
-    uint32_t *Target = reinterpret_cast<uint32_t*>(LocalAddress);
+    uint32_t *Target = reinterpret_cast<uint32_t*>(TargetAddr);
     *Target = TruncatedAddr;
     break;
   }
   case ELF::R_X86_64_PC32: {
-    uint32_t *Placeholder = reinterpret_cast<uint32_t*>(LocalAddress);
-    int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
-    assert(RealOffset <= 214783647 && RealOffset >= -214783648);
-    int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
+    uint32_t *Placeholder = reinterpret_cast<uint32_t*>(TargetAddr);
+    uint64_t RealOffset = *Placeholder +
+                           reinterpret_cast<uint64_t>(Addr) +
+                           RE.Addend - reinterpret_cast<uint64_t>(TargetAddr);
+    assert((RealOffset & 0xFFFFFFFF) == RealOffset);
+    uint32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
     *Placeholder = TruncOffset;
     break;
   }
   }
 }
 
-void RuntimeDyldELF::resolveX86Relocation(uint8_t *LocalAddress,
-                                          uint32_t FinalAddress,
-                                          uint32_t Value,
-                                          uint32_t Type,
-                                          int32_t Addend) {
-  switch (Type) {
+void RuntimeDyldELF::resolveX86Relocation(StringRef Name,
+                                          uint8_t *Addr,
+                                          const RelocationEntry &RE) {
+  uint8_t *TargetAddr;
+  if (RE.IsFunctionRelative) {
+    StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(RE.Target);
+    assert(Loc != SymbolTable.end() && "Function for relocation not found");
+    TargetAddr =
+      reinterpret_cast<uint8_t*>(Sections[Loc->second.first].base()) +
+      Loc->second.second + RE.Offset;
+  } else {
+    // FIXME: Get the address of the target section and add that to RE.Offset
+    llvm_unreachable("Non-function relocation not implemented yet!");
+  }
+
+  switch (RE.Type) {
   case ELF::R_386_32: {
-    uint32_t *Target = (uint32_t*)(LocalAddress);
-    *Target = Value + Addend;
+    uint8_t **Target = reinterpret_cast<uint8_t**>(TargetAddr);
+    *Target = Addr + RE.Addend;
     break;
   }
   case ELF::R_386_PC32: {
-    uint32_t *Placeholder = reinterpret_cast<uint32_t*>(LocalAddress);
-    uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
+    uint32_t *Placeholder = reinterpret_cast<uint32_t*>(TargetAddr);
+    uint32_t RealOffset = *Placeholder + reinterpret_cast<uintptr_t>(Addr) +
+                           RE.Addend - reinterpret_cast<uintptr_t>(TargetAddr);
     *Placeholder = RealOffset;
     break;
     }
@@ -84,174 +248,57 @@ void RuntimeDyldELF::resolveX86Relocation(uint8_t *LocalAddress,
       // There are other relocation types, but it appears these are the
       //  only ones currently used by the LLVM ELF object writer
       llvm_unreachable("Relocation type not implemented yet!");
-      break;
   }
 }
 
-void RuntimeDyldELF::resolveARMRelocation(uint8_t *LocalAddress,
-                                          uint32_t FinalAddress,
-                                          uint32_t Value,
-                                          uint32_t Type,
-                                          int32_t Addend) {
-  // TODO: Add Thumb relocations.
-  uint32_t* TargetPtr = (uint32_t*)LocalAddress;
-  Value += Addend;
-
-  DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " << LocalAddress
-               << " FinalAddress: " << format("%p",FinalAddress)
-               << " Value: " << format("%x",Value)
-               << " Type: " << format("%x",Type)
-               << " Addend: " << format("%x",Addend)
-               << "\n");
-
-  switch(Type) {
-  default:
-    llvm_unreachable("Not implemented relocation type!");
-
-  // Just write 32bit value to relocation address
-  case ELF::R_ARM_ABS32 :
-    *TargetPtr = Value;
-    break;
-
-  // Write first 16 bit of 32 bit value to the mov instruction.
-  // Last 4 bit should be shifted.
-  case ELF::R_ARM_MOVW_ABS_NC :
-    Value = Value & 0xFFFF;
-    *TargetPtr |= Value & 0xFFF;
-    *TargetPtr |= ((Value >> 12) & 0xF) << 16;
-    break;
-
-  // Write last 16 bit of 32 bit value to the mov instruction.
-  // Last 4 bit should be shifted.
-  case ELF::R_ARM_MOVT_ABS :
-    Value = (Value >> 16) & 0xFFFF;
-    *TargetPtr |= Value & 0xFFF;
-    *TargetPtr |= ((Value >> 12) & 0xF) << 16;
-    break;
-
-  // Write 24 bit relative value to the branch instruction.
-  case ELF::R_ARM_PC24 :    // Fall through.
-  case ELF::R_ARM_CALL :    // Fall through.
-  case ELF::R_ARM_JUMP24 :
-    int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
-    RelValue = (RelValue & 0x03FFFFFC) >> 2;
-    *TargetPtr &= 0xFF000000;
-    *TargetPtr |= RelValue;
-    break;
-  }
+void RuntimeDyldELF::resolveArmRelocation(StringRef Name,
+                                          uint8_t *Addr,
+                                          const RelocationEntry &RE) {
 }
 
-void RuntimeDyldELF::resolveRelocation(uint8_t *LocalAddress,
-                                       uint64_t FinalAddress,
-                                       uint64_t Value,
-                                       uint32_t Type,
-                                       int64_t Addend) {
+void RuntimeDyldELF::resolveRelocation(StringRef Name,
+                                       uint8_t *Addr,
+                                       const RelocationEntry &RE) {
   switch (Arch) {
   case Triple::x86_64:
-    resolveX86_64Relocation(LocalAddress, FinalAddress, Value, Type, Addend);
+    resolveX86_64Relocation(Name, Addr, RE);
     break;
   case Triple::x86:
-    resolveX86Relocation(LocalAddress, (uint32_t)(FinalAddress & 0xffffffffL),
-                         (uint32_t)(Value & 0xffffffffL), Type,
-                         (uint32_t)(Addend & 0xffffffffL));
+    resolveX86Relocation(Name, Addr, RE);
     break;
-  case Triple::arm:    // Fall through.
-  case Triple::thumb:
-    resolveARMRelocation(LocalAddress, (uint32_t)(FinalAddress & 0xffffffffL),
-                         (uint32_t)(Value & 0xffffffffL), Type,
-                         (uint32_t)(Addend & 0xffffffffL));
+  case Triple::arm:
+    resolveArmRelocation(Name, Addr, RE);
     break;
   default: llvm_unreachable("Unsupported CPU type!");
   }
 }
 
-void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel,
-                                          const ObjectFile &Obj,
-                                          ObjSectionToIDMap &ObjSectionToID,
-                                          LocalSymbolMap &Symbols,
-                                          StubMap &Stubs) {
-
-  uint32_t RelType = (uint32_t)(Rel.Type & 0xffffffffL);
-  intptr_t Addend = (intptr_t)Rel.AdditionalInfo;
-  RelocationValueRef Value;
-  StringRef TargetName;
-  const SymbolRef &Symbol = Rel.Symbol;
-  Symbol.getName(TargetName);
-  DEBUG(dbgs() << "\t\tRelType: " << RelType
-               << " Addend: " << Addend
-               << " TargetName: " << TargetName
-               << "\n");
-  // First look the symbol in object file symbols.
-  LocalSymbolMap::iterator lsi = Symbols.find(TargetName.data());
-  if (lsi != Symbols.end()) {
-    Value.SectionID = lsi->second.first;
-    Value.Addend = lsi->second.second;
-  } else {
-    // Second look the symbol in global symbol table.
-    StringMap<SymbolLoc>::iterator gsi = SymbolTable.find(TargetName.data());
-    if (gsi != SymbolTable.end()) {
-      Value.SectionID = gsi->second.first;
-      Value.Addend = gsi->second.second;
-    } else {
-      SymbolRef::Type SymType;
-      Symbol.getType(SymType);
-      switch (SymType) {
-        case SymbolRef::ST_Debug: {
-          // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
-          // and can be changed by another developers. Maybe best way is add
-          // a new symbol type ST_Section to SymbolRef and use it.
-          section_iterator si = Obj.end_sections();
-          Symbol.getSection(si);
-          if (si == Obj.end_sections())
-            llvm_unreachable("Symbol section not found, bad object file format!");
-          DEBUG(dbgs() << "\t\tThis is section symbol\n");
-          Value.SectionID = findOrEmitSection((*si), true, ObjSectionToID);
-          Value.Addend = Addend;
-          break;
-        }
-        case SymbolRef::ST_Unknown: {
-          Value.SymbolName = TargetName.data();
-          Value.Addend = Addend;
-          break;
-        }
-        default:
-          llvm_unreachable("Unresolved symbol type!");
-          break;
-      }
-    }
+void RuntimeDyldELF::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
+  // FIXME: deprecated. switch to reassignSectionAddress() instead.
+  //
+  // Actually moving the symbol address requires by-section mapping.
+  assert(Sections[SymbolTable.lookup(Name).first].base() == (void*)Addr &&
+         "Unable to relocate section in by-function JIT allocation model!");
+
+  RelocationList &Relocs = Relocations[Name];
+  for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
+    RelocationEntry &RE = Relocs[i];
+    resolveRelocation(Name, Addr, RE);
   }
-  DEBUG(dbgs() << "\t\tRel.SectionID: " << Rel.SectionID
-               << " Rel.Offset: " << Rel.Offset
-               << "\n");
-  if (Arch == Triple::arm &&
-      (RelType == ELF::R_ARM_PC24 ||
-       RelType == ELF::R_ARM_CALL ||
-       RelType == ELF::R_ARM_JUMP24)) {
-    // This is an ARM branch relocation, need to use a stub function.
-    DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
-    SectionEntry &Section = Sections[Rel.SectionID];
-    uint8_t *Target = Section.Address + Rel.Offset;
-
-    //  Look up for existing stub.
-    StubMap::const_iterator i = Stubs.find(Value);
-    if (i != Stubs.end()) {
-      resolveRelocation(Target, Section.LoadAddress, (uint64_t)Section.Address +
-                        i->second, RelType, 0);
-      DEBUG(dbgs() << " Stub function found\n");
-    } else {
-      // Create a new stub function.
-      DEBUG(dbgs() << " Create a new stub function\n");
-      Stubs[Value] = Section.StubOffset;
-      uint8_t *StubTargetAddr = createStubFunction(Section.Address +
-                                                   Section.StubOffset);
-      AddRelocation(Value, Rel.SectionID,
-                    StubTargetAddr - Section.Address, ELF::R_ARM_ABS32);
-      resolveRelocation(Target, Section.LoadAddress, (uint64_t)Section.Address +
-                        Section.StubOffset, RelType, 0);
-      Section.StubOffset += getMaxStubSize();
-    }
-  } else
-    AddRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
+}
+
+// Assign an address to a symbol name and resolve all the relocations
+// associated with it.
+void RuntimeDyldELF::reassignSectionAddress(unsigned SectionID, uint64_t Addr) {
+  // The address to use for relocation resolution is not
+  // the address of the local section buffer. We must be doing
+  // a remote execution environment of some sort. Re-apply any
+  // relocations referencing this section with the given address.
+  //
+  // Addr is a uint64_t because we can't assume the pointer width
+  // of the target is the same as that of the host. Just use a generic
+  // "big enough" type.
+  assert(0);
 }
 
 bool RuntimeDyldELF::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
index 36566da57a..e0f7d54f43 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
@@ -21,42 +21,158 @@ using namespace llvm;
 
 namespace llvm {
 class RuntimeDyldELF : public RuntimeDyldImpl {
-protected:
-  void resolveX86_64Relocation(uint8_t *LocalAddress,
-                               uint64_t FinalAddress,
-                               uint64_t Value,
-                               uint32_t Type,
-                               int64_t Addend);
-
-  void resolveX86Relocation(uint8_t *LocalAddress,
-                            uint32_t FinalAddress,
-                            uint32_t Value,
-                            uint32_t Type,
-                            int32_t Addend);
-
-  void resolveARMRelocation(uint8_t *LocalAddress,
-                            uint32_t FinalAddress,
-                            uint32_t Value,
-                            uint32_t Type,
-                            int32_t Addend);
-
-  virtual void resolveRelocation(uint8_t *LocalAddress,
-                                 uint64_t FinalAddress,
-                                 uint64_t Value,
-                                 uint32_t Type,
-                                 int64_t Addend);
-
-  virtual void processRelocationRef(const ObjRelocationInfo &Rel,
-                                    const ObjectFile &Obj,
-                                    ObjSectionToIDMap &ObjSectionToID,
-                                    LocalSymbolMap &Symbols, StubMap &Stubs);
+    // For each symbol, keep a list of relocations based on it. Anytime
+    // its address is reassigned (the JIT re-compiled the function, e.g.),
+    // the relocations get re-resolved.
+    struct RelocationEntry {
+      // Function or section this relocation is contained in.
+      std::string Target;
+      // Offset into the target function or section for the relocation.
+      uint32_t    Offset;
+      // Relocation type
+      uint32_t    Type;
+      // Addend encoded in the instruction itself, if any.
+      int32_t     Addend;
+      // Has the relocation been recalcuated as an offset within a function?
+      bool        IsFunctionRelative;
+      // Has this relocation been resolved previously?
+      bool        isResolved;
+
+      RelocationEntry(StringRef t,
+                      uint32_t offset,
+                      uint32_t type,
+                      int32_t addend,
+                      bool isFunctionRelative)
+        : Target(t)
+        , Offset(offset)
+        , Type(type)
+        , Addend(addend)
+        , IsFunctionRelative(isFunctionRelative)
+        , isResolved(false) { }
+    };
+    typedef SmallVector<RelocationEntry, 4> RelocationList;
+    StringMap<RelocationList> Relocations;
+    unsigned Arch;
+
+    void resolveRelocations();
+
+    void resolveX86_64Relocation(StringRef Name,
+                                 uint8_t *Addr,
+                                 const RelocationEntry &RE);
+
+    void resolveX86Relocation(StringRef Name,
+                              uint8_t *Addr,
+                              const RelocationEntry &RE);
+
+    void resolveArmRelocation(StringRef Name,
+                              uint8_t *Addr,
+                              const RelocationEntry &RE);
+
+    void resolveRelocation(StringRef Name,
+                           uint8_t *Addr,
+                           const RelocationEntry &RE);
+
+public:
+  RuntimeDyldELF(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
+
+  bool loadObject(MemoryBuffer *InputBuffer);
+
+  void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
+  void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
+
+  bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const;
+};
+
+} // end namespace llvm
+
+#endif 
+
+//===-- RuntimeDyldELF.h - Run-time dynamic linker for MC-JIT ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// ELF support for MC-JIT runtime dynamic linker.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_RUNTIME_DYLD_ELF_H
+#define LLVM_RUNTIME_DYLD_ELF_H
+
+#include "RuntimeDyldImpl.h"
+
+using namespace llvm;
+
+
+namespace llvm {
+class RuntimeDyldELF : public RuntimeDyldImpl {
+    // For each symbol, keep a list of relocations based on it. Anytime
+    // its address is reassigned (the JIT re-compiled the function, e.g.),
+    // the relocations get re-resolved.
+    struct RelocationEntry {
+      // Function or section this relocation is contained in.
+      std::string Target;
+      // Offset into the target function or section for the relocation.
+      uint32_t    Offset;
+      // Relocation type
+      uint32_t    Type;
+      // Addend encoded in the instruction itself, if any.
+      int32_t     Addend;
+      // Has the relocation been recalcuated as an offset within a function?
+      bool        IsFunctionRelative;
+      // Has this relocation been resolved previously?
+      bool        isResolved;
+
+      RelocationEntry(StringRef t,
+                      uint32_t offset,
+                      uint32_t type,
+                      int32_t addend,
+                      bool isFunctionRelative)
+        : Target(t)
+        , Offset(offset)
+        , Type(type)
+        , Addend(addend)
+        , IsFunctionRelative(isFunctionRelative)
+        , isResolved(false) { }
+    };
+    typedef SmallVector<RelocationEntry, 4> RelocationList;
+    StringMap<RelocationList> Relocations;
+    unsigned Arch;
+
+    void resolveRelocations();
+
+    void resolveX86_64Relocation(StringRef Name,
+                                 uint8_t *Addr,
+                                 const RelocationEntry &RE);
+
+    void resolveX86Relocation(StringRef Name,
+                              uint8_t *Addr,
+                              const RelocationEntry &RE);
+
+    void resolveArmRelocation(StringRef Name,
+                              uint8_t *Addr,
+                              const RelocationEntry &RE);
+
+    void resolveRelocation(StringRef Name,
+                           uint8_t *Addr,
+                           const RelocationEntry &RE);
 
 public:
   RuntimeDyldELF(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
 
+  bool loadObject(MemoryBuffer *InputBuffer);
+
+  void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
+  void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
+
   bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const;
 };
 
 } // end namespace llvm
 
-#endif
+#endif 
+
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
index d6430a91c2..28e99be9ab 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
@@ -15,125 +15,45 @@
 #define LLVM_RUNTIME_DYLD_IMPL_H
 
 #include "llvm/ExecutionEngine/RuntimeDyld.h"
-#include "llvm/Object/ObjectFile.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
 #include "llvm/Support/Memory.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/system_error.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/ADT/Triple.h"
-#include <map>
-#include "llvm/Support/Format.h"
 
 using namespace llvm;
-using namespace llvm::object;
 
 namespace llvm {
-
-class SectionEntry {
-public:
-  uint8_t* Address;
-  size_t Size;
-  uint64_t LoadAddress;   // For each section, the address it will be
-                          // considered to live at for relocations. The same
-                          // as the pointer to the above memory block for
-                          // hosted JITs.
-  uintptr_t StubOffset;   // It's used for architecturies with stub
-                          // functions for far relocations like ARM.
-  uintptr_t ObjAddress;   // Section address in object file. It's use for
-                          // calculate MachO relocation addend
-  SectionEntry(uint8_t* address, size_t size, uintptr_t stubOffset,
-               uintptr_t objAddress)
-    : Address(address), Size(size), LoadAddress((uintptr_t)address),
-      StubOffset(stubOffset), ObjAddress(objAddress) {}
-};
-
-class RelocationEntry {
-public:
-  unsigned    SectionID;  // Section the relocation is contained in.
-  uintptr_t   Offset;     // Offset into the section for the relocation.
-  uint32_t    Data;       // Relocatino data. Including type of relocation
-                          // and another flags and parameners from
-  intptr_t    Addend;     // Addend encoded in the instruction itself, if any,
-                          // plus the offset into the source section for
-                          // the symbol once the relocation is resolvable.
-  RelocationEntry(unsigned id, uint64_t offset, uint32_t data, int64_t addend)
-    : SectionID(id), Offset(offset), Data(data), Addend(addend) {}
-};
-
-// Raw relocation data from object file
-class ObjRelocationInfo {
-public:
-  unsigned  SectionID;
-  uint64_t  Offset;
-  SymbolRef Symbol;
-  uint64_t  Type;
-  int64_t   AdditionalInfo;
-};
-
-class RelocationValueRef {
-public:
-  unsigned  SectionID;
-  intptr_t  Addend;
-  const char *SymbolName;
-  RelocationValueRef(): SectionID(0), Addend(0), SymbolName(0) {}
-
-  inline bool operator==(const RelocationValueRef &Other) const {
-    return std::memcmp(this, &Other, sizeof(RelocationValueRef)) == 0;
-  }
-  inline bool operator <(const RelocationValueRef &Other) const {
-    return std::memcmp(this, &Other, sizeof(RelocationValueRef)) < 0;
-  }
-};
-
 class RuntimeDyldImpl {
 protected:
+  unsigned CPUType;
+  unsigned CPUSubtype;
+
   // The MemoryManager to load objects into.
   RTDyldMemoryManager *MemMgr;
 
-  // A list of emmitted sections.
-  typedef SmallVector<SectionEntry, 64> SectionList;
-  SectionList Sections;
+  // For each section, we have a MemoryBlock of it's data.
+  // Indexed by SectionID.
+  SmallVector<sys::MemoryBlock, 32> Sections;
+  // For each section, the address it will be considered to live at for
+  // relocations. The same as the pointer to the above memory block for hosted
+  // JITs. Indexed by SectionID.
+  SmallVector<uint64_t, 32> SectionLoadAddress;
 
-  // Keep a map of sections from object file to the SectionID which
-  // references it.
-  typedef std::map<SectionRef, unsigned> ObjSectionToIDMap;
+  // Keep a map of starting local address to the SectionID which references it.
+  // Lookup function for when we assign virtual addresses.
+  DenseMap<void *, unsigned> SectionLocalMemToID;
 
   // Master symbol table. As modules are loaded and external symbols are
   // resolved, their addresses are stored here as a SectionID/Offset pair.
-  typedef std::pair<unsigned, uintptr_t> SymbolLoc;
+  typedef std::pair<unsigned, uint64_t> SymbolLoc;
   StringMap<SymbolLoc> SymbolTable;
-  typedef DenseMap<const char*, SymbolLoc> LocalSymbolMap;
-
-  // For each symbol, keep a list of relocations based on it. Anytime
-  // its address is reassigned (the JIT re-compiled the function, e.g.),
-  // the relocations get re-resolved.
-  // The symbol (or section) the relocation is sourced from is the Key
-  // in the relocation list where it's stored.
-  typedef SmallVector<RelocationEntry, 64> RelocationList;
-  // Relocations to sections already loaded. Indexed by SectionID which is the
-  // source of the address. The target where the address will be writen is
-  // SectionID/Offset in the relocation itself.
-  DenseMap<unsigned, RelocationList> Relocations;
-  // Relocations to external symbols that are not yet resolved.
-  // Indexed by symbol name.
-  StringMap<RelocationList> SymbolRelocations;
-
-  typedef std::map<RelocationValueRef, uintptr_t> StubMap;
-
-  Triple::ArchType Arch;
-
-  inline unsigned getMaxStubSize() {
-    if (Arch == Triple::arm || Arch == Triple::thumb)
-      return 8; // 32-bit instruction and 32-bit address
-    else
-      return 0;
-  }
 
   bool HasError;
   std::string ErrorStr;
@@ -146,62 +66,17 @@ protected:
   }
 
   uint8_t *getSectionAddress(unsigned SectionID) {
-    return (uint8_t*)Sections[SectionID].Address;
+    return (uint8_t*)Sections[SectionID].base();
   }
+  void extractFunction(StringRef Name, uint8_t *StartAddress,
+                       uint8_t *EndAddress);
 
-  /// \brief Emits section data from the object file to the MemoryManager.
-  /// \param IsCode if it's true then allocateCodeSection() will be
-  ///        used for emmits, else allocateDataSection() will be used.
-  /// \return SectionID.
-  unsigned emitSection(const SectionRef &Section, bool IsCode);
-
-  /// \brief Find Section in LocalSections. If the secton is not found - emit
-  ///        it and store in LocalSections.
-  /// \param IsCode if it's true then allocateCodeSection() will be
-  ///        used for emmits, else allocateDataSection() will be used.
-  /// \return SectionID.
-  unsigned findOrEmitSection(const SectionRef &Section, bool IsCode,
-                             ObjSectionToIDMap &LocalSections);
-
-  /// \brief If Value.SymbolName is NULL then store relocation to the
-  ///        Relocations, else store it in the SymbolRelocations.
-  void AddRelocation(const RelocationValueRef &Value, unsigned SectionID,
-                     uintptr_t Offset, uint32_t RelType);
-
-  /// \brief Emits long jump instruction to Addr.
-  /// \return Pointer to the memory area for emitting target address.
-  uint8_t* createStubFunction(uint8_t *Addr);
-
-  /// \brief Resolves relocations from Relocs list with address from Value.
-  void resolveRelocationList(const RelocationList &Relocs, uint64_t Value);
-  void resolveRelocationEntry(const RelocationEntry &RE, uint64_t Value);
-
-  /// \brief A object file specific relocation resolver
-  /// \param Address Address to apply the relocation action
-  /// \param Value Target symbol address to apply the relocation action
-  /// \param Type object file specific relocation type
-  /// \param Addend A constant addend used to compute the value to be stored
-  ///        into the relocatable field
-  virtual void resolveRelocation(uint8_t *LocalAddress,
-                                 uint64_t FinalAddress,
-                                 uint64_t Value,
-                                 uint32_t Type,
-                                 int64_t Addend) = 0;
-
-  /// \brief Parses the object file relocation and store it to Relocations
-  ///        or SymbolRelocations. Its depend from object file type.
-  virtual void processRelocationRef(const ObjRelocationInfo &Rel,
-                                    const ObjectFile &Obj,
-                                    ObjSectionToIDMap &ObjSectionToID,
-                                    LocalSymbolMap &Symbols, StubMap &Stubs) = 0;
-
-  void resolveSymbols();
 public:
   RuntimeDyldImpl(RTDyldMemoryManager *mm) : MemMgr(mm), HasError(false) {}
 
   virtual ~RuntimeDyldImpl();
 
-  bool loadObject(const MemoryBuffer *InputBuffer);
+  virtual bool loadObject(MemoryBuffer *InputBuffer) = 0;
 
   void *getSymbolAddress(StringRef Name) {
     // FIXME: Just look up as a function for now. Overly simple of course.
@@ -212,9 +87,9 @@ public:
     return getSectionAddress(Loc.first) + Loc.second;
   }
 
-  void resolveRelocations();
+  virtual void resolveRelocations();
 
-  void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
+  virtual void reassignSectionAddress(unsigned SectionID, uint64_t Addr) = 0;
 
   void mapSectionAddress(void *LocalAddress, uint64_t TargetAddress);
 
@@ -228,7 +103,6 @@ public:
   StringRef getErrorString() { return ErrorStr; }
 
   virtual bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const = 0;
-
 };
 
 } // end namespace llvm
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 1318b44542..7130e0e174 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -21,55 +21,41 @@ using namespace llvm::object;
 
 namespace llvm {
 
-void RuntimeDyldMachO::resolveRelocation(uint8_t *LocalAddress,
-                                         uint64_t FinalAddress,
-                                         uint64_t Value,
-                                         uint32_t Type,
-                                         int64_t Addend) {
-  bool isPCRel = (Type >> 24) & 1;
-  unsigned MachoType = (Type >> 28) & 0xf;
-  unsigned Size = 1 << ((Type >> 25) & 3);
-
-  DEBUG(dbgs() << "resolveRelocation LocalAddress: " << format("%p", LocalAddress)
-        << " FinalAddress: " << format("%p", FinalAddress)
-        << " Value: " << format("%p", Value)
-        << " Addend: " << Addend
-        << " isPCRel: " << isPCRel
-        << " MachoType: " << MachoType
-        << " Size: " << Size
-        << "\n");
-
+bool RuntimeDyldMachO::
+resolveRelocation(uint8_t *LocalAddress,
+                  uint64_t FinalAddress,
+                  uint64_t Value,
+                  bool isPCRel,
+                  unsigned Type,
+                  unsigned Size,
+                  int64_t Addend) {
   // This just dispatches to the proper target specific routine.
-  switch (Arch) {
+  switch (CPUType) {
   default: llvm_unreachable("Unsupported CPU type!");
-  case Triple::x86_64:
-    resolveX86_64Relocation(LocalAddress,
-                            FinalAddress,
-                            (uintptr_t)Value,
-                            isPCRel,
-                            MachoType,
-                            Size,
-                            Addend);
-    break;
-  case Triple::x86:
-    resolveI386Relocation(LocalAddress,
+  case mach::CTM_i386:
+    return resolveI386Relocation(LocalAddress,
                                  FinalAddress,
                                  (uintptr_t)Value,
                                  isPCRel,
                                  Type,
                                  Size,
                                  Addend);
-    break;
-  case Triple::arm:    // Fall through.
-  case Triple::thumb:
-    resolveARMRelocation(LocalAddress,
-                         FinalAddress,
-                         (uintptr_t)Value,
-                         isPCRel,
-                         MachoType,
-                         Size,
-                         Addend);
-    break;
+  case mach::CTM_x86_64:
+    return resolveX86_64Relocation(LocalAddress,
+                                   FinalAddress,
+                                   (uintptr_t)Value,
+                                   isPCRel,
+                                   Type,
+                                   Size,
+                                   Addend);
+  case mach::CTM_ARM:
+    return resolveARMRelocation(LocalAddress,
+                                FinalAddress,
+                                (uintptr_t)Value,
+                                isPCRel,
+                                Type,
+                                Size,
+                                Addend);
   }
 }
 
@@ -204,84 +190,503 @@ resolveARMRelocation(uint8_t *LocalAddress,
   return false;
 }
 
-void RuntimeDyldMachO::processRelocationRef(const ObjRelocationInfo &Rel,
-                                            const ObjectFile &Obj,
-                                            ObjSectionToIDMap &ObjSectionToID,
-                                            LocalSymbolMap &Symbols,
-                                            StubMap &Stubs) {
-
-  uint32_t RelType = (uint32_t) (Rel.Type & 0xffffffffL);
-  RelocationValueRef Value;
-  SectionEntry &Section = Sections[Rel.SectionID];
-  uint8_t *Target = Section.Address + Rel.Offset;
-
-  bool isExtern = (RelType >> 27) & 1;
-  if (isExtern) {
-    StringRef TargetName;
-    const SymbolRef &Symbol = Rel.Symbol;
-    Symbol.getName(TargetName);
-    // First look the symbol in object file symbols.
-    LocalSymbolMap::iterator lsi = Symbols.find(TargetName.data());
-    if (lsi != Symbols.end()) {
-      Value.SectionID = lsi->second.first;
-      Value.Addend = lsi->second.second;
-    } else {
-      // Second look the symbol in global symbol table.
-      StringMap<SymbolLoc>::iterator gsi = SymbolTable.find(TargetName.data());
-      if (gsi != SymbolTable.end()) {
-        Value.SectionID = gsi->second.first;
-        Value.Addend = gsi->second.second;
-      } else
-        Value.SymbolName = TargetName.data();
-    }
-  } else {
-    error_code err;
-    uint8_t sectionIndex = static_cast<uint8_t>(RelType & 0xFF);
-    section_iterator si = Obj.begin_sections(),
-                     se = Obj.end_sections();
-    for (uint8_t i = 1; i < sectionIndex; i++) {
-      error_code err;
-      si.increment(err);
-      if (si == se)
-        break;
+bool RuntimeDyldMachO::
+loadSegment32(const MachOObject *Obj,
+              const MachOObject::LoadCommandInfo *SegmentLCI,
+              const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
+  // FIXME: This should really be combined w/ loadSegment64. Templatized
+  // function on the 32/64 datatypes maybe?
+  InMemoryStruct<macho::SegmentLoadCommand> SegmentLC;
+  Obj->ReadSegmentLoadCommand(*SegmentLCI, SegmentLC);
+  if (!SegmentLC)
+    return Error("unable to load segment load command");
+
+
+  SmallVector<unsigned, 16> SectionMap;
+  for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
+    InMemoryStruct<macho::Section> Sect;
+    Obj->ReadSection(*SegmentLCI, SectNum, Sect);
+    if (!Sect)
+      return Error("unable to load section: '" + Twine(SectNum) + "'");
+
+    // Allocate memory via the MM for the section.
+    uint8_t *Buffer;
+    uint32_t SectionID = Sections.size();
+    if (Sect->Flags == 0x80000400)
+      Buffer = MemMgr->allocateCodeSection(Sect->Size, Sect->Align, SectionID);
+    else
+      Buffer = MemMgr->allocateDataSection(Sect->Size, Sect->Align, SectionID);
+
+    DEBUG(dbgs() << "Loading "
+                 << ((Sect->Flags == 0x80000400) ? "text" : "data")
+                 << " (ID #" << SectionID << ")"
+                 << " '" << Sect->SegmentName << ","
+                 << Sect->Name << "' of size " << Sect->Size
+                 << " to address " << Buffer << ".\n");
+
+    // Copy the payload from the object file into the allocated buffer.
+    uint8_t *Base = (uint8_t*)Obj->getData(SegmentLC->FileOffset,
+                                           SegmentLC->FileSize).data();
+    memcpy(Buffer, Base + Sect->Address, Sect->Size);
+
+    // Remember what got allocated for this SectionID.
+    Sections.push_back(sys::MemoryBlock(Buffer, Sect->Size));
+    SectionLocalMemToID[Buffer] = SectionID;
+
+    // By default, the load address of a section is its memory buffer.
+    SectionLoadAddress.push_back((uint64_t)Buffer);
+
+    // Keep a map of object file section numbers to corresponding SectionIDs
+    // while processing the file.
+    SectionMap.push_back(SectionID);
+  }
+
+  // Process the symbol table.
+  SmallVector<StringRef, 64> SymbolNames;
+  processSymbols32(Obj, SectionMap, SymbolNames, SymtabLC);
+
+  // Process the relocations for each section we're loading.
+  Relocations.grow(Relocations.size() + SegmentLC->NumSections);
+  Referrers.grow(Referrers.size() + SegmentLC->NumSections);
+  for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
+    InMemoryStruct<macho::Section> Sect;
+    Obj->ReadSection(*SegmentLCI, SectNum, Sect);
+    if (!Sect)
+      return Error("unable to load section: '" + Twine(SectNum) + "'");
+    for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
+      InMemoryStruct<macho::RelocationEntry> RE;
+      Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
+      if (RE->Word0 & macho::RF_Scattered)
+        return Error("NOT YET IMPLEMENTED: scattered relocations.");
+      // Word0 of the relocation is the offset into the section where the
+      // relocation should be applied. We need to translate that into an
+      // offset into a function since that's our atom.
+      uint32_t Offset = RE->Word0;
+      bool isExtern = (RE->Word1 >> 27) & 1;
+
+      // FIXME: Get the relocation addend from the target address.
+      // FIXME: VERY imporant for internal relocations.
+
+      // Figure out the source symbol of the relocation. If isExtern is true,
+      // this relocation references the symbol table, otherwise it references
+      // a section in the same object, numbered from 1 through NumSections
+      // (SectionBases is [0, NumSections-1]).
+      uint32_t SourceNum = RE->Word1 & 0xffffff; // 24-bit value
+      if (!isExtern) {
+        assert(SourceNum > 0 && "Invalid relocation section number!");
+        unsigned SectionID = SectionMap[SourceNum - 1];
+        unsigned TargetID = SectionMap[SectNum];
+        DEBUG(dbgs() << "Internal relocation at Section #"
+                     << TargetID << " + " << Offset
+                     << " from Section #"
+                     << SectionID << " (Word1: "
+                     << format("0x%x", RE->Word1) << ")\n");
+
+        // Store the relocation information. It will get resolved when
+        // the section addresses are assigned.
+        uint32_t RelocationIndex = Relocations[SectionID].size();
+        Relocations[SectionID].push_back(RelocationEntry(TargetID,
+                                                         Offset,
+                                                         RE->Word1,
+                                                         0 /*Addend*/));
+        Referrers[TargetID].push_back(Referrer(SectionID, RelocationIndex));
+      } else {
+        StringRef SourceName = SymbolNames[SourceNum];
+
+        // Now store the relocation information. Associate it with the source
+        // symbol. Just add it to the unresolved list and let the general
+        // path post-load resolve it if we know where the symbol is.
+        UnresolvedRelocations[SourceName].push_back(RelocationEntry(SectNum,
+                                                                    Offset,
+                                                                    RE->Word1,
+                                                                 0 /*Addend*/));
+        DEBUG(dbgs() << "Relocation at Section #" << SectNum << " + " << Offset
+              << " from '" << SourceName << "(Word1: "
+              << format("0x%x", RE->Word1) << ")\n");
+      }
     }
-    assert(si != se && "No section containing relocation!");
-    Value.SectionID = findOrEmitSection(*si, true, ObjSectionToID);
-    Value.Addend = *(const intptr_t *)Target;
-    if (Value.Addend) {
-      // The MachO addend is offset from the current section, we need set it
-      // as offset from destination section
-      Value.Addend += Section.ObjAddress - Sections[Value.SectionID].ObjAddress;
+  }
+
+  // Resolve the addresses of any symbols that were defined in this segment.
+  for (int i = 0, e = SymbolNames.size(); i != e; ++i)
+    resolveSymbol(SymbolNames[i]);
+
+  return false;
+}
+
+
+bool RuntimeDyldMachO::
+loadSegment64(const MachOObject *Obj,
+              const MachOObject::LoadCommandInfo *SegmentLCI,
+              const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
+  InMemoryStruct<macho::Segment64LoadCommand> Segment64LC;
+  Obj->ReadSegment64LoadCommand(*SegmentLCI, Segment64LC);
+  if (!Segment64LC)
+    return Error("unable to load segment load command");
+
+
+  SmallVector<unsigned, 16> SectionMap;
+  for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
+    InMemoryStruct<macho::Section64> Sect;
+    Obj->ReadSection64(*SegmentLCI, SectNum, Sect);
+    if (!Sect)
+      return Error("unable to load section: '" + Twine(SectNum) + "'");
+
+    // Allocate memory via the MM for the section.
+    uint8_t *Buffer;
+    uint32_t SectionID = Sections.size();
+    unsigned Align = 1 << Sect->Align; // .o file has log2 alignment.
+    if (Sect->Flags == 0x80000400)
+      Buffer = MemMgr->allocateCodeSection(Sect->Size, Align, SectionID);
+    else
+      Buffer = MemMgr->allocateDataSection(Sect->Size, Align, SectionID);
+
+    DEBUG(dbgs() << "Loading "
+                 << ((Sect->Flags == 0x80000400) ? "text" : "data")
+                 << " (ID #" << SectionID << ")"
+                 << " '" << Sect->SegmentName << ","
+                 << Sect->Name << "' of size " << Sect->Size
+                 << " (align " << Align << ")"
+                 << " to address " << Buffer << ".\n");
+
+    // Copy the payload from the object file into the allocated buffer.
+    uint8_t *Base = (uint8_t*)Obj->getData(Segment64LC->FileOffset,
+                                           Segment64LC->FileSize).data();
+    memcpy(Buffer, Base + Sect->Address, Sect->Size);
+
+    // Remember what got allocated for this SectionID.
+    Sections.push_back(sys::MemoryBlock(Buffer, Sect->Size));
+    SectionLocalMemToID[Buffer] = SectionID;
+
+    // By default, the load address of a section is its memory buffer.
+    SectionLoadAddress.push_back((uint64_t)Buffer);
+
+    // Keep a map of object file section numbers to corresponding SectionIDs
+    // while processing the file.
+    SectionMap.push_back(SectionID);
+  }
+
+  // Process the symbol table.
+  SmallVector<StringRef, 64> SymbolNames;
+  processSymbols64(Obj, SectionMap, SymbolNames, SymtabLC);
+
+  // Process the relocations for each section we're loading.
+  Relocations.grow(Relocations.size() + Segment64LC->NumSections);
+  Referrers.grow(Referrers.size() + Segment64LC->NumSections);
+  for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
+    InMemoryStruct<macho::Section64> Sect;
+    Obj->ReadSection64(*SegmentLCI, SectNum, Sect);
+    if (!Sect)
+      return Error("unable to load section: '" + Twine(SectNum) + "'");
+    for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
+      InMemoryStruct<macho::RelocationEntry> RE;
+      Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
+      if (RE->Word0 & macho::RF_Scattered)
+        return Error("NOT YET IMPLEMENTED: scattered relocations.");
+      // Word0 of the relocation is the offset into the section where the
+      // relocation should be applied. We need to translate that into an
+      // offset into a function since that's our atom.
+      uint32_t Offset = RE->Word0;
+      bool isExtern = (RE->Word1 >> 27) & 1;
+
+      // FIXME: Get the relocation addend from the target address.
+      // FIXME: VERY imporant for internal relocations.
+
+      // Figure out the source symbol of the relocation. If isExtern is true,
+      // this relocation references the symbol table, otherwise it references
+      // a section in the same object, numbered from 1 through NumSections
+      // (SectionBases is [0, NumSections-1]).
+      uint32_t SourceNum = RE->Word1 & 0xffffff; // 24-bit value
+      if (!isExtern) {
+        assert(SourceNum > 0 && "Invalid relocation section number!");
+        unsigned SectionID = SectionMap[SourceNum - 1];
+        unsigned TargetID = SectionMap[SectNum];
+        DEBUG(dbgs() << "Internal relocation at Section #"
+                     << TargetID << " + " << Offset
+                     << " from Section #"
+                     << SectionID << " (Word1: "
+                     << format("0x%x", RE->Word1) << ")\n");
+
+        // Store the relocation information. It will get resolved when
+        // the section addresses are assigned.
+        uint32_t RelocationIndex = Relocations[SectionID].size();
+        Relocations[SectionID].push_back(RelocationEntry(TargetID,
+                                                         Offset,
+                                                         RE->Word1,
+                                                         0 /*Addend*/));
+        Referrers[TargetID].push_back(Referrer(SectionID, RelocationIndex));
+      } else {
+        StringRef SourceName = SymbolNames[SourceNum];
+
+        // Now store the relocation information. Associate it with the source
+        // symbol. Just add it to the unresolved list and let the general
+        // path post-load resolve it if we know where the symbol is.
+        UnresolvedRelocations[SourceName].push_back(RelocationEntry(SectNum,
+                                                                    Offset,
+                                                                    RE->Word1,
+                                                                 0 /*Addend*/));
+        DEBUG(dbgs() << "Relocation at Section #" << SectNum << " + " << Offset
+              << " from '" << SourceName << "(Word1: "
+              << format("0x%x", RE->Word1) << ")\n");
+      }
     }
   }
 
-  if (Arch == Triple::arm && RelType == macho::RIT_ARM_Branch24Bit) {
-    // This is an ARM branch relocation, need to use a stub function.
-
-    //  Look up for existing stub.
-    StubMap::const_iterator i = Stubs.find(Value);
-    if (i != Stubs.end())
-      resolveRelocation(Target, (uint64_t)Target,
-                        (uint64_t)Section.Address + i->second,
-                        RelType, 0);
-    else {
-      // Create a new stub function.
-      Stubs[Value] = Section.StubOffset;
-      uint8_t *StubTargetAddr = createStubFunction(Section.Address +
-                                                   Section.StubOffset);
-      AddRelocation(Value, Rel.SectionID, StubTargetAddr - Section.Address,
-                    macho::RIT_Vanilla);
-      resolveRelocation(Target, (uint64_t)Target,
-                        (uint64_t)Section.Address + Section.StubOffset,
-                        RelType, 0);
-      Section.StubOffset += getMaxStubSize();
+  // Resolve the addresses of any symbols that were defined in this segment.
+  for (int i = 0, e = SymbolNames.size(); i != e; ++i)
+    resolveSymbol(SymbolNames[i]);
+
+  return false;
+}
+
+bool RuntimeDyldMachO::
+processSymbols32(const MachOObject *Obj,
+                 SmallVectorImpl<unsigned> &SectionMap,
+                 SmallVectorImpl<StringRef> &SymbolNames,
+                 const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
+  // FIXME: Combine w/ processSymbols64. Factor 64/32 datatype and such.
+  for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
+    InMemoryStruct<macho::SymbolTableEntry> STE;
+    Obj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE);
+    if (!STE)
+      return Error("unable to read symbol: '" + Twine(i) + "'");
+    // Get the symbol name.
+    StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
+    SymbolNames.push_back(Name);
+
+    // FIXME: Check the symbol type and flags.
+    if (STE->Type != 0xF)  // external, defined in this segment.
+      continue;
+    // Flags in the upper nibble we don't care about.
+    if ((STE->Flags & 0xf) != 0x0)
+      continue;
+
+    // Remember the symbol.
+    uint32_t SectionID = SectionMap[STE->SectionIndex - 1];
+    SymbolTable[Name] = SymbolLoc(SectionID, STE->Value);
+
+    DEBUG(dbgs() << "Symbol: '" << Name << "' @ "
+                 << (getSectionAddress(SectionID) + STE->Value)
+                 << "\n");
+  }
+  return false;
+}
+
+bool RuntimeDyldMachO::
+processSymbols64(const MachOObject *Obj,
+                 SmallVectorImpl<unsigned> &SectionMap,
+                 SmallVectorImpl<StringRef> &SymbolNames,
+                 const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
+  for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
+    InMemoryStruct<macho::Symbol64TableEntry> STE;
+    Obj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE);
+    if (!STE)
+      return Error("unable to read symbol: '" + Twine(i) + "'");
+    // Get the symbol name.
+    StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
+    SymbolNames.push_back(Name);
+
+    // FIXME: Check the symbol type and flags.
+    if (STE->Type != 0xF)  // external, defined in this segment.
+      continue;
+    // Flags in the upper nibble we don't care about.
+    if ((STE->Flags & 0xf) != 0x0)
+      continue;
+
+    // Remember the symbol.
+    uint32_t SectionID = SectionMap[STE->SectionIndex - 1];
+    SymbolTable[Name] = SymbolLoc(SectionID, STE->Value);
+
+    DEBUG(dbgs() << "Symbol: '" << Name << "' @ "
+                 << (getSectionAddress(SectionID) + STE->Value)
+                 << "\n");
+  }
+  return false;
+}
+
+// resolveSymbol - Resolve any relocations to the specified symbol if
+// we know where it lives.
+void RuntimeDyldMachO::resolveSymbol(StringRef Name) {
+  StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Name);
+  if (Loc == SymbolTable.end())
+    return;
+
+  RelocationList &Relocs = UnresolvedRelocations[Name];
+  DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n");
+  for (int i = 0, e = Relocs.size(); i != e; ++i) {
+    // Change the relocation to be section relative rather than symbol
+    // relative and move it to the resolved relocation list.
+    RelocationEntry Entry = Relocs[i];
+    Entry.Addend += Loc->second.second;
+    uint32_t RelocationIndex = Relocations[Loc->second.first].size();
+    Relocations[Loc->second.first].push_back(Entry);
+    Referrers[Entry.SectionID].push_back(Referrer(Loc->second.first, RelocationIndex));
+  }
+  // FIXME: Keep a worklist of the relocations we've added so that we can
+  // resolve more selectively later.
+  Relocs.clear();
+}
+
+bool RuntimeDyldMachO::loadObject(MemoryBuffer *InputBuffer) {
+  // If the linker is in an error state, don't do anything.
+  if (hasError())
+    return true;
+  // Load the Mach-O wrapper object.
+  std::string ErrorStr;
+  OwningPtr<MachOObject> Obj(
+    MachOObject::LoadFromBuffer(InputBuffer, &ErrorStr));
+  if (!Obj)
+    return Error("unable to load object: '" + ErrorStr + "'");
+
+  // Get the CPU type information from the header.
+  const macho::Header &Header = Obj->getHeader();
+
+  // FIXME: Error checking that the loaded object is compatible with
+  //        the system we're running on.
+  CPUType = Header.CPUType;
+  CPUSubtype = Header.CPUSubtype;
+
+  // Validate that the load commands match what we expect.
+  const MachOObject::LoadCommandInfo *SegmentLCI = 0, *SymtabLCI = 0,
+    *DysymtabLCI = 0;
+  for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
+    const MachOObject::LoadCommandInfo &LCI = Obj->getLoadCommandInfo(i);
+    switch (LCI.Command.Type) {
+    case macho::LCT_Segment:
+    case macho::LCT_Segment64:
+      if (SegmentLCI)
+        return Error("unexpected input object (multiple segments)");
+      SegmentLCI = &LCI;
+      break;
+    case macho::LCT_Symtab:
+      if (SymtabLCI)
+        return Error("unexpected input object (multiple symbol tables)");
+      SymtabLCI = &LCI;
+      break;
+    case macho::LCT_Dysymtab:
+      if (DysymtabLCI)
+        return Error("unexpected input object (multiple symbol tables)");
+      DysymtabLCI = &LCI;
+      break;
+    default:
+      return Error("unexpected input object (unexpected load command");
     }
-  } else
-    AddRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
+  }
+
+  if (!SymtabLCI)
+    return Error("no symbol table found in object");
+  if (!SegmentLCI)
+    return Error("no segments found in object");
+
+  // Read and register the symbol table data.
+  InMemoryStruct<macho::SymtabLoadCommand> SymtabLC;
+  Obj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
+  if (!SymtabLC)
+    return Error("unable to load symbol table load command");
+  Obj->RegisterStringTable(*SymtabLC);
+
+  // Read the dynamic link-edit information, if present (not present in static
+  // objects).
+  if (DysymtabLCI) {
+    InMemoryStruct<macho::DysymtabLoadCommand> DysymtabLC;
+    Obj->ReadDysymtabLoadCommand(*DysymtabLCI, DysymtabLC);
+    if (!DysymtabLC)
+      return Error("unable to load dynamic link-exit load command");
+
+    // FIXME: We don't support anything interesting yet.
+//    if (DysymtabLC->LocalSymbolsIndex != 0)
+//      return Error("NOT YET IMPLEMENTED: local symbol entries");
+//    if (DysymtabLC->ExternalSymbolsIndex != 0)
+//      return Error("NOT YET IMPLEMENTED: non-external symbol entries");
+//    if (DysymtabLC->UndefinedSymbolsIndex != SymtabLC->NumSymbolTableEntries)
+//      return Error("NOT YET IMPLEMENTED: undefined symbol entries");
+  }
+
+  // Load the segment load command.
+  if (SegmentLCI->Command.Type == macho::LCT_Segment) {
+    if (loadSegment32(Obj.get(), SegmentLCI, SymtabLC))
+      return true;
+  } else {
+    if (loadSegment64(Obj.get(), SegmentLCI, SymtabLC))
+      return true;
+  }
+
+  // Assign the addresses of the sections from the object so that any
+  // relocations to them get set properly.
+  // FIXME: This is done directly from the client at the moment. We should
+  // default the values to the local storage, at least when the target arch
+  // is the same as the host arch.
+
+  return false;
 }
 
+// Assign an address to a symbol name and resolve all the relocations
+// associated with it.
+void RuntimeDyldMachO::reassignSectionAddress(unsigned SectionID,
+                                              uint64_t Addr) {
+  // The address to use for relocation resolution is not
+  // the address of the local section buffer. We must be doing
+  // a remote execution environment of some sort. Re-apply any
+  // relocations referencing this section with the given address.
+  //
+  // Addr is a uint64_t because we can't assume the pointer width
+  // of the target is the same as that of the host. Just use a generic
+  // "big enough" type.
+
+  SectionLoadAddress[SectionID] = Addr;
+
+  RelocationList &Relocs = Relocations[SectionID];
+  for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
+    RelocationEntry &RE = Relocs[i];
+    uint8_t *Target = (uint8_t*)Sections[RE.SectionID].base() + RE.Offset;
+    uint64_t FinalTarget = (uint64_t)SectionLoadAddress[RE.SectionID] + RE.Offset;
+    bool isPCRel = (RE.Data >> 24) & 1;
+    unsigned Type = (RE.Data >> 28) & 0xf;
+    unsigned Size = 1 << ((RE.Data >> 25) & 3);
+
+    DEBUG(dbgs() << "Resolving relocation at Section #" << RE.SectionID
+          << " + " << RE.Offset << " (" << format("%p", Target) << ")"
+          << " from Section #" << SectionID << " (" << format("%p", Addr) << ")"
+          << "(" << (isPCRel ? "pcrel" : "absolute")
+          << ", type: " << Type << ", Size: " << Size << ", Addend: "
+          << RE.Addend << ").\n");
+
+    resolveRelocation(Target,
+                      FinalTarget,
+                      Addr,
+                      isPCRel,
+                      Type,
+                      Size,
+                      RE.Addend);
+  }
+  ReferrerList &Refers = Referrers[SectionID];
+  for (unsigned i = 0, e = Refers.size(); i != e; ++i) {
+    Referrer &R = Refers[i];
+    RelocationEntry &RE = Relocations[R.SectionID][R.Index];
+    uint8_t *Target = (uint8_t*)Sections[RE.SectionID].base() + RE.Offset;
+    uint64_t FinalTarget = (uint64_t)SectionLoadAddress[RE.SectionID] + RE.Offset;
+    bool isPCRel = (RE.Data >> 24) & 1;
+    unsigned Type = (RE.Data >> 28) & 0xf;
+    unsigned Size = 1 << ((RE.Data >> 25) & 3);
+
+    DEBUG(dbgs() << "Resolving relocation at Section #" << RE.SectionID
+          << " + " << RE.Offset << " (" << format("%p", Target) << ")"
+          << " from Section #" << SectionID << " (" << format("%p", Addr) << ")"
+          << "(" << (isPCRel ? "pcrel" : "absolute")
+          << ", type: " << Type << ", Size: " << Size << ", Addend: "
+          << RE.Addend << ").\n");
+
+    resolveRelocation(Target,
+                      FinalTarget,
+                      Addr,
+                      isPCRel,
+                      Type,
+                      Size,
+                      RE.Addend);
+  }
+}
 
-bool RuntimeDyldMachO::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
+bool RuntimeDyldMachO::isKnownFormat(const MemoryBuffer *InputBuffer) {
   StringRef Magic = InputBuffer->getBuffer().slice(0, 4);
   if (Magic == "\xFE\xED\xFA\xCE") return true;
   if (Magic == "\xCE\xFA\xED\xFE") return true;
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
index 898b85190e..48a7253242 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
@@ -25,7 +25,55 @@ using namespace llvm::object;
 
 namespace llvm {
 class RuntimeDyldMachO : public RuntimeDyldImpl {
-protected:
+
+  // For each symbol, keep a list of relocations based on it. Anytime
+  // its address is reassigned (the JIT re-compiled the function, e.g.),
+  // the relocations get re-resolved.
+  // The symbol (or section) the relocation is sourced from is the Key
+  // in the relocation list where it's stored.
+  struct RelocationEntry {
+    unsigned    SectionID;  // Section the relocation is contained in.
+    uint64_t    Offset;     // Offset into the section for the relocation.
+    uint32_t    Data;       // Second word of the raw macho relocation entry.
+    int64_t     Addend;     // Addend encoded in the instruction itself, if any,
+                            // plus the offset into the source section for
+                            // the symbol once the relocation is resolvable.
+
+    RelocationEntry(unsigned id, uint64_t offset, uint32_t data, int64_t addend)
+      : SectionID(id), Offset(offset), Data(data), Addend(addend) {}
+  };
+  typedef SmallVector<RelocationEntry, 4> RelocationList;
+
+  // For each section, keep a list of referrers in that section that are clients
+  // of relocations in other sections.  Whenever a relocation gets created,
+  // create a corresponding referrer.  Whenever relocations are re-resolved,
+  // re-resolve the referrers' relocations as well.
+  struct Referrer {
+    unsigned    SectionID;  // Section whose RelocationList contains the relocation.
+    uint32_t    Index;      // Index of the RelocatonEntry in that RelocationList.
+
+    Referrer(unsigned id, uint32_t index)
+      : SectionID(id), Index(index) {}
+  };
+  typedef SmallVector<Referrer, 4> ReferrerList;
+
+  // Relocations to sections already loaded. Indexed by SectionID which is the
+  // source of the address. The target where the address will be writen is
+  // SectionID/Offset in the relocation itself.
+  IndexedMap<RelocationList> Relocations;
+  // Referrers corresponding to Relocations.
+  IndexedMap<ReferrerList> Referrers;
+  // Relocations to symbols that are not yet resolved. Must be external
+  // relocations by definition. Indexed by symbol name.
+  StringMap<RelocationList> UnresolvedRelocations;
+
+  bool resolveRelocation(uint8_t *LocalAddress,
+                         uint64_t FinalAddress,
+                         uint64_t Value,
+                         bool isPCRel,
+                         unsigned Type,
+                         unsigned Size,
+                         int64_t Addend);
   bool resolveI386Relocation(uint8_t *LocalAddress,
                              uint64_t FinalAddress,
                              uint64_t Value,
@@ -48,21 +96,35 @@ protected:
                             unsigned Size,
                             int64_t Addend);
 
-  virtual void processRelocationRef(const ObjRelocationInfo &Rel,
-                                    const ObjectFile &Obj,
-                                    ObjSectionToIDMap &ObjSectionToID,
-                                    LocalSymbolMap &Symbols, StubMap &Stubs);
+  bool loadSegment32(const MachOObject *Obj,
+                     const MachOObject::LoadCommandInfo *SegmentLCI,
+                     const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
+  bool loadSegment64(const MachOObject *Obj,
+                     const MachOObject::LoadCommandInfo *SegmentLCI,
+                     const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
+  bool processSymbols32(const MachOObject *Obj,
+                      SmallVectorImpl<unsigned> &SectionMap,
+                      SmallVectorImpl<StringRef> &SymbolNames,
+                      const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
+  bool processSymbols64(const MachOObject *Obj,
+                      SmallVectorImpl<unsigned> &SectionMap,
+                      SmallVectorImpl<StringRef> &SymbolNames,
+                      const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
+
+  void resolveSymbol(StringRef Name);
 
 public:
-  virtual void resolveRelocation(uint8_t *LocalAddress,
-                                 uint64_t FinalAddress,
-                                 uint64_t Value,
-                                 uint32_t Type,
-                                 int64_t Addend);
-                                 
   RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
 
-  bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const;
+  bool loadObject(MemoryBuffer *InputBuffer);
+
+  void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
+
+  static bool isKnownFormat(const MemoryBuffer *InputBuffer);
+
+  bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
+    return isKnownFormat(InputBuffer);
+  }
 };
 
 } // end namespace llvm