diff --git a/tools/dsymutil/DwarfLinker.cpp b/tools/dsymutil/DwarfLinker.cpp
index 4af8efb03af..7f6d69cc7de 100644
--- a/tools/dsymutil/DwarfLinker.cpp
+++ b/tools/dsymutil/DwarfLinker.cpp
@@ -20,6 +20,30 @@ namespace dsymutil {
 
 namespace {
 
+/// \brief Stores all information relating to a compile unit, be it in
+/// its original instance in the object file to its brand new cloned
+/// and linked DIE tree.
+class CompileUnit {
+public:
+  /// \brief Information gathered about a DIE in the object file.
+  struct DIEInfo {
+    uint32_t ParentIdx;
+  };
+
+  CompileUnit(DWARFUnit &OrigUnit) : OrigUnit(OrigUnit) {
+    Info.resize(OrigUnit.getNumDIEs());
+  }
+
+  DWARFUnit &getOrigUnit() { return OrigUnit; }
+
+  DIEInfo &getInfo(unsigned Idx) { return Info[Idx]; }
+  const DIEInfo &getInfo(unsigned Idx) const { return Info[Idx]; }
+
+private:
+  DWARFUnit &OrigUnit;
+  std::vector<DIEInfo> Info; ///< DIE info indexed by DIE index.
+};
+
 /// \brief The core of the Dwarf linking logic.
 class DwarfLinker {
 public:
@@ -29,12 +53,41 @@ public:
   /// \brief Link the contents of the DebugMap.
   bool link(const DebugMap &);
 
+private:
+  /// \brief Called at the start of a debug object link.
+  void startDebugObject(DWARFContext &);
+
+  /// \brief Called at the end of a debug object link.
+  void endDebugObject();
+
 private:
   std::string OutputFilename;
   bool Verbose;
   BinaryHolder BinHolder;
+
+  /// The units of the current debug map object.
+  std::vector<CompileUnit> Units;
 };
 
+/// \brief Recursive helper to gather the child->parent relationships in the
+/// original compile unit.
+void GatherDIEParents(const DWARFDebugInfoEntryMinimal *DIE, unsigned ParentIdx,
+                      CompileUnit &CU) {
+  unsigned MyIdx = CU.getOrigUnit().getDIEIndex(DIE);
+  CU.getInfo(MyIdx).ParentIdx = ParentIdx;
+
+  if (DIE->hasChildren())
+    for (auto *Child = DIE->getFirstChild(); Child && !Child->isNULL();
+         Child = Child->getSibling())
+      GatherDIEParents(Child, MyIdx, CU);
+}
+
+void DwarfLinker::startDebugObject(DWARFContext &Dwarf) {
+  Units.reserve(Dwarf.getNumCompileUnits());
+}
+
+void DwarfLinker::endDebugObject() { Units.clear(); }
+
 bool DwarfLinker::link(const DebugMap &Map) {
 
   if (Map.begin() == Map.end()) {
@@ -51,15 +104,24 @@ bool DwarfLinker::link(const DebugMap &Map) {
       continue;
     }
 
+    // Setup access to the debug info.
     DWARFContextInMemory DwarfContext(*ErrOrObj);
+    startDebugObject(DwarfContext);
 
+    // In a first phase, just read in the debug info and store the DIE
+    // parent links that we will use during the next phase.
     for (const auto &CU : DwarfContext.compile_units()) {
       auto *CUDie = CU->getCompileUnitDIE(false);
       if (Verbose) {
         outs() << "Input compilation unit:";
         CUDie->dump(outs(), CU.get(), 0);
       }
+      Units.emplace_back(*CU);
+      GatherDIEParents(CUDie, 0, Units.back());
     }
+
+    // Clean-up before starting working on the next object.
+    endDebugObject();
   }
 
   return true;