diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
@@ -79,6 +79,8 @@
           DIERef::Section section, lldb::offset_t *offset_ptr);
   virtual ~DWARFUnit();
 
+  bool IsDWOUnit() { return m_is_dwo; }
+
   void ExtractUnitDIEIfNeeded();
   void ExtractDIEsIfNeeded();
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -347,6 +347,7 @@
   DWARFUnit *dwo_cu = dwo_symbol_file->GetCompileUnit();
   if (!dwo_cu)
     return; // Can't fetch the compile unit from the dwo file.
+  dwo_cu->SetUserData(this);
 
   DWARFBaseDIE dwo_cu_die = dwo_cu->GetUnitDIEOnly();
   if (!dwo_cu_die.IsValid())
@@ -563,11 +564,7 @@
 
 void *DWARFUnit::GetUserData() const { return m_user_data; }
 
-void DWARFUnit::SetUserData(void *d) {
-  m_user_data = d;
-  if (m_dwo_symbol_file)
-    m_dwo_symbol_file->GetCompileUnit()->SetUserData(d);
-}
+void DWARFUnit::SetUserData(void *d) { m_user_data = d; }
 
 bool DWARFUnit::Supports_DW_AT_APPLE_objc_complete_type() {
   return GetProducer() != eProducerLLVMGCC;
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/ManualDWARFIndex.cpp b/lldb/source/Plugins/SymbolFile/DWARF/ManualDWARFIndex.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/ManualDWARFIndex.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/ManualDWARFIndex.cpp
@@ -89,7 +89,7 @@
 
 void ManualDWARFIndex::IndexUnit(DWARFUnit &unit, IndexSet &set) {
   assert(
-      !unit.GetSymbolFileDWARF().GetBaseCompileUnit() &&
+      !unit.IsDWOUnit() &&
       "DWARFUnit associated with .dwo or .dwp should not be indexed directly");
 
   Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS);
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
@@ -246,8 +246,6 @@
 
   static DWARFDIE GetParentSymbolContextDIE(const DWARFDIE &die);
 
-  virtual lldb::CompUnitSP ParseCompileUnit(DWARFCompileUnit &dwarf_cu);
-
   lldb::ModuleSP GetExternalModule(lldb_private::ConstString name);
 
   typedef std::map<lldb_private::ConstString, lldb::ModuleSP>
@@ -276,11 +274,6 @@
   GetDwoSymbolFileForCompileUnit(DWARFUnit &dwarf_cu,
                                  const DWARFDebugInfoEntry &cu_die);
 
-  // For regular SymbolFileDWARF instances the method returns nullptr,
-  // for the instances of the subclass SymbolFileDWARFDwo
-  // the method returns a pointer to the base compile unit.
-  virtual DWARFCompileUnit *GetBaseCompileUnit() { return nullptr; }
-
   virtual llvm::Optional<uint32_t> GetDwoNum() { return llvm::None; }
 
   /// If this is a DWARF object with a single CU, return its DW_AT_dwo_id.
@@ -347,6 +340,8 @@
 
   lldb_private::TypeList &GetTypeList() override;
 
+  lldb::CompUnitSP ParseCompileUnit(DWARFCompileUnit &dwarf_cu);
+
   virtual DWARFUnit *
   GetDWARFCompileUnit(lldb_private::CompileUnit *comp_unit);
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -645,9 +645,7 @@
     // We already parsed this compile unit, had out a shared pointer to it
     cu_sp = comp_unit->shared_from_this();
   } else {
-    if (&dwarf_cu.GetSymbolFileDWARF() != this) {
-      return dwarf_cu.GetSymbolFileDWARF().ParseCompileUnit(dwarf_cu);
-    } else if (dwarf_cu.GetOffset() == 0 && GetDebugMapSymfile()) {
+    if (dwarf_cu.GetOffset() == 0 && GetDebugMapSymfile()) {
       // Let the debug map create the compile unit
       cu_sp = m_debug_map_symfile->GetCompileUnit(this);
       dwarf_cu.SetUserData(cu_sp.get());
@@ -1454,13 +1452,17 @@
 
 CompileUnit *
 SymbolFileDWARF::GetCompUnitForDWARFCompUnit(DWARFCompileUnit &dwarf_cu) {
+  DWARFCompileUnit *non_dwo_cu =
+      dwarf_cu.IsDWOUnit()
+          ? static_cast<DWARFCompileUnit *>(dwarf_cu.GetUserData())
+          : &dwarf_cu;
   // Check if the symbol vendor already knows about this compile unit?
-  if (dwarf_cu.GetUserData() == nullptr) {
+  if (non_dwo_cu->GetUserData() == nullptr) {
     // The symbol vendor doesn't know about this compile unit, we need to parse
     // and add it to the symbol vendor object.
-    return ParseCompileUnit(dwarf_cu).get();
+    return ParseCompileUnit(*non_dwo_cu).get();
   }
-  return (CompileUnit *)dwarf_cu.GetUserData();
+  return static_cast<CompileUnit *>(non_dwo_cu->GetUserData());
 }
 
 size_t SymbolFileDWARF::GetObjCMethodDIEOffsets(ConstString class_name,
@@ -1605,7 +1607,8 @@
   if (dwo_obj_file == nullptr)
     return nullptr;
 
-  return std::make_unique<SymbolFileDWARFDwo>(dwo_obj_file, *dwarf_cu);
+  return std::make_unique<SymbolFileDWARFDwo>(*this, dwo_obj_file,
+                                              dwarf_cu->GetID());
 }
 
 void SymbolFileDWARF::UpdateExternalModuleListIfNeeded() {
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.h b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.h
@@ -24,12 +24,11 @@
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
 
-  SymbolFileDWARFDwo(lldb::ObjectFileSP objfile, DWARFCompileUnit &dwarf_cu);
+  SymbolFileDWARFDwo(SymbolFileDWARF &m_base_symbol_file,
+                     lldb::ObjectFileSP objfile, uint32_t id);
 
   ~SymbolFileDWARFDwo() override = default;
 
-  lldb::CompUnitSP ParseCompileUnit(DWARFCompileUnit &dwarf_cu) override;
-
   DWARFCompileUnit *GetCompileUnit();
 
   DWARFUnit *
@@ -44,8 +43,6 @@
   DWARFDIE
   GetDIE(const DIERef &die_ref) override;
 
-  DWARFCompileUnit *GetBaseCompileUnit() override { return &m_base_dwarf_cu; }
-
   llvm::Optional<uint32_t> GetDwoNum() override { return GetID() >> 32; }
 
 protected:
@@ -69,11 +66,11 @@
       const DWARFDIE &die, lldb_private::ConstString type_name,
       bool must_be_implementation) override;
 
-  SymbolFileDWARF &GetBaseSymbolFile();
+  SymbolFileDWARF &GetBaseSymbolFile() { return m_base_symbol_file; }
 
   DWARFCompileUnit *ComputeCompileUnit();
 
-  DWARFCompileUnit &m_base_dwarf_cu;
+  SymbolFileDWARF &m_base_symbol_file;
   DWARFCompileUnit *m_cu = nullptr;
 };
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.cpp
@@ -23,12 +23,12 @@
 
 char SymbolFileDWARFDwo::ID;
 
-SymbolFileDWARFDwo::SymbolFileDWARFDwo(ObjectFileSP objfile,
-                                       DWARFCompileUnit &dwarf_cu)
+SymbolFileDWARFDwo::SymbolFileDWARFDwo(SymbolFileDWARF &base_symbol_file,
+                                       ObjectFileSP objfile, uint32_t id)
     : SymbolFileDWARF(objfile, objfile->GetSectionList(
                                    /*update_module_section_list*/ false)),
-      m_base_dwarf_cu(dwarf_cu) {
-  SetID(((lldb::user_id_t)dwarf_cu.GetID()) << 32);
+      m_base_symbol_file(base_symbol_file) {
+  SetID(user_id_t(id) << 32);
 }
 
 void SymbolFileDWARFDwo::LoadSectionData(lldb::SectionType sect_type,
@@ -49,14 +49,6 @@
   SymbolFileDWARF::LoadSectionData(sect_type, data);
 }
 
-lldb::CompUnitSP
-SymbolFileDWARFDwo::ParseCompileUnit(DWARFCompileUnit &dwarf_cu) {
-  assert(GetCompileUnit() == &dwarf_cu &&
-         "SymbolFileDWARFDwo::ParseCompileUnit called with incompatible "
-         "compile unit");
-  return GetBaseSymbolFile().ParseCompileUnit(m_base_dwarf_cu);
-}
-
 DWARFCompileUnit *SymbolFileDWARFDwo::GetCompileUnit() {
   if (!m_cu)
     m_cu = ComputeCompileUnit();
@@ -133,10 +125,6 @@
       die, type_name, must_be_implementation);
 }
 
-SymbolFileDWARF &SymbolFileDWARFDwo::GetBaseSymbolFile() {
-  return m_base_dwarf_cu.GetSymbolFileDWARF();
-}
-
 llvm::Expected<TypeSystem &>
 SymbolFileDWARFDwo::GetTypeSystemForLanguage(LanguageType language) {
   return GetBaseSymbolFile().GetTypeSystemForLanguage(language);
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwoDwp.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwoDwp.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwoDwp.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwoDwp.cpp
@@ -13,7 +13,7 @@
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Utility/LLDBAssert.h"
 
-#include "DWARFUnit.h"
+#include "DWARFCompileUnit.h"
 #include "DWARFDebugInfo.h"
 
 using namespace lldb;
@@ -25,8 +25,9 @@
                                              ObjectFileSP objfile,
                                              DWARFCompileUnit &dwarf_cu,
                                              uint64_t dwo_id)
-    : SymbolFileDWARFDwo(objfile, dwarf_cu), m_dwp_symfile(dwp_symfile),
-      m_dwo_id(dwo_id) {}
+    : SymbolFileDWARFDwo(dwarf_cu.GetSymbolFileDWARF(), objfile,
+                         dwarf_cu.GetID()),
+      m_dwp_symfile(dwp_symfile), m_dwo_id(dwo_id) {}
 
 void SymbolFileDWARFDwoDwp::LoadSectionData(lldb::SectionType sect_type,
                                             DWARFDataExtractor &data) {