Index: include/llvm/Object/MachO.h
===================================================================
--- include/llvm/Object/MachO.h
+++ include/llvm/Object/MachO.h
@@ -100,6 +100,7 @@
   error_code getRelocationValueString(DataRefImpl Rel,
                                   SmallVectorImpl<char> &Result) const override;
   error_code getRelocationHidden(DataRefImpl Rel, bool &Result) const override;
+  error_code getRelocationLength(DataRefImpl Rel, uint8_t &Res) const;
 
   error_code getLibraryNext(DataRefImpl LibData,
                             LibraryRef &Res) const override;
Index: include/llvm/Object/RelocVisitor.h
===================================================================
--- include/llvm/Object/RelocVisitor.h
+++ include/llvm/Object/RelocVisitor.h
@@ -18,9 +18,11 @@
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/MachO.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ELF.h"
+#include "llvm/Support/MachO.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace llvm {
@@ -161,6 +163,14 @@
       case llvm::ELF::R_ARM_ABS32:
         return visitELF_ARM_ABS32(R, Value);
       }
+    } else if (FileFormat == "Mach-O 64-bit x86-64") {
+      switch (RelocType) {
+      case llvm::MachO::X86_64_RELOC_UNSIGNED:
+        return visitMACHO_X86_64_UNSIGNED(R, Value);
+      default:
+        HasError = true;
+        return RelocToApply();
+      }
     }
     HasError = true;
     return RelocToApply();
@@ -203,6 +213,15 @@
     Obj->getRelocationAddend(DRI, Addend);
     return Addend;
   }
+
+  uint8_t getLengthMachO64(RelocationRef R) {
+    const MachOObjectFile *Obj = cast<MachOObjectFile>(R.getObjectFile());
+    DataRefImpl DRI = R.getRawDataRefImpl();
+    uint8_t Length;
+    Obj->getRelocationLength(DRI, Length);
+    return Length;
+  }
+
   /// Operations
 
   /// 386-ELF
@@ -338,6 +357,14 @@
     return RelocToApply(Value + Addend, 4);
   }
 
+  RelocToApply visitMACHO_X86_64_UNSIGNED(RelocationRef R, uint64_t Value) {
+    uint8_t Length = getLengthMachO64(R);
+    Length = 1<<Length;
+    // Addend is taken care of when the relocation is actually applied
+    // i.e. the relocation is applied using += rather than =
+    return RelocToApply(Value, Length);
+  }
+
 };
 
 }
Index: lib/DebugInfo/DWARFContext.cpp
===================================================================
--- lib/DebugInfo/DWARFContext.cpp
+++ lib/DebugInfo/DWARFContext.cpp
@@ -724,11 +724,19 @@
         Reloc.getType(Type);
         uint64_t SymAddr = 0;
         // ELF relocations may need the symbol address
-        if (Obj->isELF()) {
+        if (Obj->isELF() || Obj->isMachO()) {
           object::symbol_iterator Sym = Reloc.getSymbol();
-          Sym->getAddress(SymAddr);
+          if (Sym != Obj->symbol_end())
+            Sym->getAddress(SymAddr);
+          else {
+            // MachO relocations can target sections however,
+            // when one is not moving sections the resulting
+            // relocation is a noop, so don't do anything here.
+          }
         }
 
+        DEBUG(dbgs() << "Sym Addr " << format("%p", SymAddr) << "\n");
+
         object::RelocVisitor V(Obj->getFileFormatName());
         // The section address is always 0 for debug sections.
         object::RelocToApply R(V.visit(Type, Reloc, 0, SymAddr));
Index: lib/Object/MachOObjectFile.cpp
===================================================================
--- lib/Object/MachOObjectFile.cpp
+++ lib/Object/MachOObjectFile.cpp
@@ -1170,6 +1170,13 @@
   return object_error::success;
 }
 
+error_code
+MachOObjectFile::getRelocationLength(DataRefImpl Rel, uint8_t &Res) const {
+  MachO::any_relocation_info RE = getRelocation(Rel);
+  Res = getAnyRelocationLength(RE);
+  return object_error::success;
+}
+
 error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
                                            LibraryRef &Res) const {
   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");