Index: lib/DebugInfo/DWARFUnit.h
===================================================================
--- lib/DebugInfo/DWARFUnit.h
+++ lib/DebugInfo/DWARFUnit.h
@@ -14,6 +14,7 @@
 #include "DWARFDebugInfoEntry.h"
 #include "DWARFDebugRangeList.h"
 #include "DWARFRelocMap.h"
+#include <utility>
 #include <vector>
 
 namespace llvm {
@@ -39,8 +40,8 @@
 
 /// Concrete instance of DWARFUnitSection, specialized for one Unit type.
 template<typename UnitType>
-class DWARFUnitSection : public SmallVector<std::unique_ptr<UnitType>, 1>,
-                         public DWARFUnitSectionBase {
+class DWARFUnitSection : public DWARFUnitSectionBase {
+  SmallVector<std::unique_ptr<UnitType>, 1> Units;
 
   struct UnitOffsetComparator {
     bool operator()(const std::unique_ptr<UnitType> &LHS,
@@ -59,13 +60,58 @@
 
 public:
   typedef llvm::SmallVectorImpl<std::unique_ptr<UnitType>> UnitVector;
+  typedef typename UnitVector::size_type size_type;
   typedef typename UnitVector::iterator iterator;
+  typedef typename UnitVector::const_iterator const_iterator;
+  typedef typename UnitVector::reference reference;
+  typedef typename UnitVector::const_reference const_reference;
   typedef llvm::iterator_range<typename UnitVector::iterator> iterator_range;
+  typedef llvm::iterator_range<typename UnitVector::const_iterator> const_iterator_range;
+
+  iterator begin() {
+    return Units.begin();
+  }
+  const_iterator begin() const {
+    return Units.begin();
+  }
+
+  iterator end() {
+    return Units.end();
+  }
+  const_iterator end() const {
+    return Units.end();
+  }
+
+  size_type size() {
+    return Units.size();
+  }
+
+  reference operator[](unsigned Index) {
+    return Units[Index];
+  }
+  const_reference operator[](unsigned Index) const {
+    return Units[Index];
+  }
+
+  bool empty() const {
+    return Units.empty();
+  }
+
+  reference back() {
+    return Units.back();
+  }
+  const_reference back() const {
+    return Units.back();
+  }
+
+  void push_back(std::unique_ptr<UnitType> &&Elt) {
+    Units.push_back(std::forward<std::unique_ptr<UnitType> &&>(Elt));
+  }
 
   UnitType *getUnitForOffset(uint32_t Offset) const {
-    auto *CU = std::lower_bound(this->begin(), this->end(), Offset,
+    auto *CU = std::lower_bound(Units.begin(), Units.end(), Offset,
                                 UnitOffsetComparator());
-    if (CU != this->end())
+    if (CU != Units.end())
       return CU->get();
     return nullptr;
   }