Index: lib/DebugInfo/DWARFCompileUnit.h
===================================================================
--- lib/DebugInfo/DWARFCompileUnit.h
+++ lib/DebugInfo/DWARFCompileUnit.h
@@ -17,10 +17,8 @@
 class DWARFCompileUnit : public DWARFUnit {
 public:
   DWARFCompileUnit(DWARFContext &Context, const DWARFSection &Section,
-                   const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
-                   StringRef SOS, StringRef AOS, bool LE,
-                   const DWARFUnitSectionBase &UnitSection)
-      : DWARFUnit(Context, Section, DA, RS, SS, SOS, AOS, LE, UnitSection) {}
+                   bool IsDWO, const DWARFUnitSectionBase &UnitSection)
+      : DWARFUnit(Context, Section, IsDWO, UnitSection) {}
   void dump(raw_ostream &OS);
   // VTable anchor.
   ~DWARFCompileUnit() override;
Index: lib/DebugInfo/DWARFTypeUnit.h
===================================================================
--- lib/DebugInfo/DWARFTypeUnit.h
+++ lib/DebugInfo/DWARFTypeUnit.h
@@ -19,11 +19,9 @@
   uint64_t TypeHash;
   uint32_t TypeOffset;
 public:
-  DWARFTypeUnit(DWARFContext &Context, const DWARFSection &Section,
-                const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
-                StringRef SOS, StringRef AOS, bool LE,
+  DWARFTypeUnit(DWARFContext &Context, const DWARFSection &Section, bool IsDWO,
                 const DWARFUnitSectionBase &UnitSection)
-      : DWARFUnit(Context, Section, DA, RS, SS, SOS, AOS, LE, UnitSection) {}
+      : DWARFUnit(Context, Section, IsDWO, UnitSection) {}
   uint32_t getHeaderSize() const override {
     return DWARFUnit::getHeaderSize() + 12;
   }
Index: lib/DebugInfo/DWARFUnit.h
===================================================================
--- lib/DebugInfo/DWARFUnit.h
+++ lib/DebugInfo/DWARFUnit.h
@@ -42,8 +42,7 @@
 
 protected:
   virtual void parseImpl(DWARFContext &Context, const DWARFSection &Section,
-                         const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
-                         StringRef SOS, StringRef AOS, bool isLittleEndian) = 0;
+                         bool IsDWO, bool isLittleEndian) = 0;
 
   ~DWARFUnitSectionBase() {}
 };
@@ -80,16 +79,14 @@
   }
 
 private:
-  void parseImpl(DWARFContext &Context, const DWARFSection &Section,
-                 const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
-                 StringRef SOS, StringRef AOS, bool LE) override {
+  void parseImpl(DWARFContext &Context, const DWARFSection &Section, bool IsDWO,
+                 bool LE) override {
     if (Parsed)
       return;
     DataExtractor Data(Section.Data, LE, 0);
     uint32_t Offset = 0;
     while (Data.isValidOffset(Offset)) {
-      auto U = llvm::make_unique<UnitType>(Context, Section, DA, RS, SS, SOS,
-                                           AOS, LE, *this);
+      auto U = llvm::make_unique<UnitType>(Context, Section, IsDWO, *this);
       if (!U->extract(Data, &Offset))
         break;
       this->push_back(std::move(U));
@@ -139,9 +136,7 @@
   virtual uint32_t getHeaderSize() const { return 11; }
 
 public:
-  DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
-            const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
-            StringRef SOS, StringRef AOS, bool LE,
+  DWARFUnit(DWARFContext &Context, const DWARFSection &Section, bool IsDWO,
             const DWARFUnitSectionBase &UnitSection);
 
   virtual ~DWARFUnit();
Index: lib/DebugInfo/DWARFUnit.cpp
===================================================================
--- lib/DebugInfo/DWARFUnit.cpp
+++ lib/DebugInfo/DWARFUnit.cpp
@@ -18,25 +18,23 @@
 using namespace dwarf;
 
 void DWARFUnitSectionBase::parse(DWARFContext &C, const DWARFSection &Section) {
-  parseImpl(C, Section, C.getDebugAbbrev(), C.getRangeSection(),
-            C.getStringSection(), StringRef(), C.getAddrSection(),
-            C.isLittleEndian());
+  parseImpl(C, Section, false, C.isLittleEndian());
 }
 
 void DWARFUnitSectionBase::parseDWO(DWARFContext &C,
                                     const DWARFSection &DWOSection) {
-  parseImpl(C, DWOSection, C.getDebugAbbrevDWO(), C.getRangeDWOSection(),
-            C.getStringDWOSection(), C.getStringOffsetDWOSection(),
-            C.getAddrSection(), C.isLittleEndian());
+  parseImpl(C, DWOSection, true, C.isLittleEndian());
 }
 
-DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section,
-                     const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
-                     StringRef SOS, StringRef AOS, bool LE,
+DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section, bool IsDWO,
                      const DWARFUnitSectionBase &UnitSection)
-    : Context(DC), InfoSection(Section), Abbrev(DA), RangeSection(RS),
-      StringSection(SS), StringOffsetSection(SOS), AddrOffsetSection(AOS),
-      isLittleEndian(LE), UnitSection(UnitSection) {
+    : Context(DC), InfoSection(Section),
+      Abbrev(IsDWO ? DC.getDebugAbbrevDWO() : DC.getDebugAbbrev()),
+      RangeSection(IsDWO ? DC.getRangeDWOSection() : DC.getRangeSection()),
+      StringSection(IsDWO ? DC.getStringDWOSection() : DC.getStringSection()),
+      StringOffsetSection(IsDWO ? DC.getStringOffsetDWOSection() : StringRef()),
+      AddrOffsetSection(DC.getAddrSection()),
+      isLittleEndian(DC.isLittleEndian()), UnitSection(UnitSection) {
   clear();
 }