diff --git a/lldb/include/lldb/Symbol/SymbolFile.h b/lldb/include/lldb/Symbol/SymbolFile.h
--- a/lldb/include/lldb/Symbol/SymbolFile.h
+++ b/lldb/include/lldb/Symbol/SymbolFile.h
@@ -36,6 +36,12 @@
 
 namespace lldb_private {
 
+/// Provides public interface for all SymbolFiles. Any protected
+/// virtual member functions should go into SymbolFileActual; most
+/// SymbolFile implementations should also inherit from SymbolFileActual
+/// to override the behaviors except SymbolFileOnDemand which inherits
+/// public interfaces from SymbolFile and forward to underlying concrete
+/// SymbolFile implementation.
 class SymbolFile : public PluginInterface {
   /// LLVM RTTI support.
   static char ID;
@@ -125,8 +131,9 @@
 
   // Compile Unit function calls
   // Approach 1 - iterator
-  uint32_t GetNumCompileUnits();
-  lldb::CompUnitSP GetCompileUnitAtIndex(uint32_t idx);
+  // Make virtual so that SymbolFileOnDemand can override.
+  virtual uint32_t GetNumCompileUnits() = 0;
+  virtual lldb::CompUnitSP GetCompileUnitAtIndex(uint32_t idx) = 0;
 
   Symtab *GetSymtab();
 
@@ -297,7 +304,7 @@
                                    "Operation not supported.");
   }
 
-  virtual void Dump(Stream &s);
+  virtual void Dump(Stream &s) = 0;
 
   /// Metrics gathering functions
 
@@ -360,18 +367,11 @@
 
 protected:
   void AssertModuleLock();
-  virtual uint32_t CalculateNumCompileUnits() = 0;
-  virtual lldb::CompUnitSP ParseCompileUnitAtIndex(uint32_t idx) = 0;
-  virtual TypeList &GetTypeList() { return m_type_list; }
-
-  void SetCompileUnitAtIndex(uint32_t idx, const lldb::CompUnitSP &cu_sp);
 
   lldb::ObjectFileSP m_objfile_sp; // Keep a reference to the object file in
                                    // case it isn't the same as the module
                                    // object file (debug symbols in a separate
                                    // file)
-  llvm::Optional<std::vector<lldb::CompUnitSP>> m_compile_units;
-  TypeList m_type_list;
   Symtab *m_symtab = nullptr;
   uint32_t m_abilities = 0;
   bool m_calculated_abilities = false;
diff --git a/lldb/include/lldb/Symbol/SymbolFileActual.h b/lldb/include/lldb/Symbol/SymbolFileActual.h
new file mode 100644
--- /dev/null
+++ b/lldb/include/lldb/Symbol/SymbolFileActual.h
@@ -0,0 +1,60 @@
+//===-- SymbolFileActual.h --------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SYMBOL_SYMBOLFILEACTUAL_H
+#define LLDB_SYMBOL_SYMBOLFILEACTUAL_H
+
+#include "lldb/Symbol/SymbolFile.h"
+
+namespace lldb_private {
+
+/// Containing protected virtual methods for child classes to override.
+/// Most actual SymbolFile implementations should inherit from this class.
+class SymbolFileActual : public SymbolFile {
+  /// LLVM RTTI support.
+  static char ID;
+
+public:
+  /// LLVM RTTI support.
+  /// \{
+  bool isA(const void *ClassID) const override {
+    return ClassID == &ID || SymbolFile::isA(ClassID);
+  }
+  static bool classof(const SymbolFileActual *obj) { return obj->isA(&ID); }
+  /// \}
+
+  // Constructors and Destructors
+  SymbolFileActual(lldb::ObjectFileSP objfile_sp)
+      : SymbolFile(std::move(objfile_sp)) {}
+
+  ~SymbolFileActual() override = default;
+
+  // Compile Unit function calls
+  // Approach 1 - iterator
+  uint32_t GetNumCompileUnits() override;
+  lldb::CompUnitSP GetCompileUnitAtIndex(uint32_t idx) override;
+
+  void Dump(Stream &s) override;
+
+protected:
+  virtual uint32_t CalculateNumCompileUnits() = 0;
+  virtual lldb::CompUnitSP ParseCompileUnitAtIndex(uint32_t idx) = 0;
+  virtual TypeList &GetTypeList() { return m_type_list; }
+  void SetCompileUnitAtIndex(uint32_t idx, const lldb::CompUnitSP &cu_sp);
+
+  llvm::Optional<std::vector<lldb::CompUnitSP>> m_compile_units;
+  TypeList m_type_list;
+
+private:
+  SymbolFileActual(const SymbolFileActual &) = delete;
+  const SymbolFileActual &operator=(const SymbolFileActual &) = delete;
+};
+
+} // namespace lldb_private
+
+#endif // LLDB_SYMBOL_SYMBOLFILEACTUAL_H
diff --git a/lldb/source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h b/lldb/source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
--- a/lldb/source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
+++ b/lldb/source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
@@ -13,14 +13,14 @@
 #include "lldb/Core/FileSpecList.h"
 #include "lldb/Symbol/LineTable.h"
 #include "lldb/Symbol/PostfixExpression.h"
-#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/SymbolFileActual.h"
 #include "lldb/Symbol/UnwindPlan.h"
 
 namespace lldb_private {
 
 namespace breakpad {
 
-class SymbolFileBreakpad : public SymbolFile {
+class SymbolFileBreakpad : public SymbolFileActual {
   /// LLVM RTTI support.
   static char ID;
 
@@ -28,7 +28,7 @@
   /// LLVM RTTI support.
   /// \{
   bool isA(const void *ClassID) const override {
-    return ClassID == &ID || SymbolFile::isA(ClassID);
+    return ClassID == &ID || SymbolFileActual::isA(ClassID);
   }
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
@@ -49,7 +49,7 @@
 
   // Constructors and Destructors
   SymbolFileBreakpad(lldb::ObjectFileSP objfile_sp)
-      : SymbolFile(std::move(objfile_sp)) {}
+      : SymbolFileActual(std::move(objfile_sp)) {}
 
   ~SymbolFileBreakpad() override = default;
 
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
@@ -23,7 +23,7 @@
 #include "lldb/Core/dwarf.h"
 #include "lldb/Symbol/DebugMacros.h"
 #include "lldb/Symbol/SymbolContext.h"
-#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/SymbolFileActual.h"
 #include "lldb/Target/Statistics.h"
 #include "lldb/Utility/ConstString.h"
 #include "lldb/Utility/Flags.h"
@@ -56,7 +56,7 @@
 
 #define DIE_IS_BEING_PARSED ((lldb_private::Type *)1)
 
-class SymbolFileDWARF : public lldb_private::SymbolFile,
+class SymbolFileDWARF : public lldb_private::SymbolFileActual,
                         public lldb_private::UserID {
   /// LLVM RTTI support.
   static char ID;
@@ -65,7 +65,7 @@
   /// LLVM RTTI support.
   /// \{
   bool isA(const void *ClassID) const override {
-    return ClassID == &ID || SymbolFile::isA(ClassID);
+    return ClassID == &ID || SymbolFileActual::isA(ClassID);
   }
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
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
@@ -274,7 +274,7 @@
   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile())
     return debug_map_symfile->GetTypeList();
-  return SymbolFile::GetTypeList();
+  return SymbolFileActual::GetTypeList();
 }
 void SymbolFileDWARF::GetTypes(const DWARFDIE &die, dw_offset_t min_die_offset,
                                dw_offset_t max_die_offset, uint32_t type_mask,
@@ -407,7 +407,7 @@
 
 SymbolFileDWARF::SymbolFileDWARF(ObjectFileSP objfile_sp,
                                  SectionList *dwo_section_list)
-    : SymbolFile(std::move(objfile_sp)),
+    : SymbolFileActual(std::move(objfile_sp)),
       UserID(0x7fffffff00000000), // Used by SymbolFileDWARFDebugMap to
                                   // when this class parses .o files to
                                   // contain the .o file index/ID
@@ -3968,7 +3968,7 @@
 }
 
 void SymbolFileDWARF::Dump(lldb_private::Stream &s) {
-  SymbolFile::Dump(s);
+  SymbolFileActual::Dump(s);
   m_index->Dump(s);
 }
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h
@@ -9,7 +9,7 @@
 #ifndef LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_SYMBOLFILEDWARFDEBUGMAP_H
 #define LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_SYMBOLFILEDWARFDEBUGMAP_H
 
-#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/SymbolFileActual.h"
 #include "lldb/Utility/RangeMap.h"
 #include "llvm/Support/Chrono.h"
 #include <bitset>
@@ -22,7 +22,7 @@
 class DWARFDebugAranges;
 class DWARFDeclContext;
 
-class SymbolFileDWARFDebugMap : public lldb_private::SymbolFile {
+class SymbolFileDWARFDebugMap : public lldb_private::SymbolFileActual {
   /// LLVM RTTI support.
   static char ID;
 
@@ -30,7 +30,7 @@
   /// LLVM RTTI support.
   /// \{
   bool isA(const void *ClassID) const override {
-    return ClassID == &ID || SymbolFile::isA(ClassID);
+    return ClassID == &ID || SymbolFileActual::isA(ClassID);
   }
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp
@@ -237,7 +237,7 @@
 }
 
 SymbolFileDWARFDebugMap::SymbolFileDWARFDebugMap(ObjectFileSP objfile_sp)
-    : SymbolFile(std::move(objfile_sp)), m_flags(), m_compile_unit_infos(),
+    : SymbolFileActual(std::move(objfile_sp)), m_flags(), m_compile_unit_infos(),
       m_func_indexes(), m_glob_indexes(),
       m_supports_DW_AT_APPLE_objc_complete_type(eLazyBoolCalculate) {}
 
diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
@@ -10,7 +10,7 @@
 #define LLDB_SOURCE_PLUGINS_SYMBOLFILE_NATIVEPDB_SYMBOLFILENATIVEPDB_H
 
 #include "lldb/Symbol/LineTable.h"
-#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/SymbolFileActual.h"
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/DebugInfo/CodeView/CVRecord.h"
@@ -39,7 +39,7 @@
 namespace npdb {
 class PdbAstBuilder;
 
-class SymbolFileNativePDB : public SymbolFile {
+class SymbolFileNativePDB : public SymbolFileActual {
   friend class UdtRecordCompleter;
 
   /// LLVM RTTI support.
@@ -49,7 +49,7 @@
   /// LLVM RTTI support.
   /// \{
   bool isA(const void *ClassID) const override {
-    return ClassID == &ID || SymbolFile::isA(ClassID);
+    return ClassID == &ID || SymbolFileActual::isA(ClassID);
   }
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -254,7 +254,7 @@
 }
 
 SymbolFileNativePDB::SymbolFileNativePDB(ObjectFileSP objfile_sp)
-    : SymbolFile(std::move(objfile_sp)) {}
+    : SymbolFileActual(std::move(objfile_sp)) {}
 
 SymbolFileNativePDB::~SymbolFileNativePDB() = default;
 
@@ -1916,4 +1916,3 @@
   // PDB files are a separate file that contains all debug info.
   return m_index->pdb().getFileSize();
 }
-
diff --git a/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h b/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h
--- a/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h
+++ b/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h
@@ -10,7 +10,7 @@
 #define LLDB_SOURCE_PLUGINS_SYMBOLFILE_PDB_SYMBOLFILEPDB_H
 
 #include "lldb/Core/UniqueCStringMap.h"
-#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/SymbolFileActual.h"
 #include "lldb/Symbol/VariableList.h"
 #include "lldb/Utility/UserID.h"
 
@@ -21,7 +21,7 @@
 
 class PDBASTParser;
 
-class SymbolFilePDB : public lldb_private::SymbolFile {
+class SymbolFilePDB : public lldb_private::SymbolFileActual {
   /// LLVM RTTI support.
   static char ID;
 
@@ -29,7 +29,7 @@
   /// LLVM RTTI support.
   /// \{
   bool isA(const void *ClassID) const override {
-    return ClassID == &ID || SymbolFile::isA(ClassID);
+    return ClassID == &ID || SymbolFileActual::isA(ClassID);
   }
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
diff --git a/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp b/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
--- a/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
@@ -135,7 +135,7 @@
 }
 
 SymbolFilePDB::SymbolFilePDB(lldb::ObjectFileSP objfile_sp)
-    : SymbolFile(std::move(objfile_sp)), m_session_up(), m_global_scope_up() {}
+    : SymbolFileActual(std::move(objfile_sp)), m_session_up(), m_global_scope_up() {}
 
 SymbolFilePDB::~SymbolFilePDB() = default;
 
diff --git a/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.h b/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.h
--- a/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.h
+++ b/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.h
@@ -12,10 +12,10 @@
 #include <map>
 #include <vector>
 
-#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/SymbolFileActual.h"
 #include "lldb/Symbol/Symtab.h"
 
-class SymbolFileSymtab : public lldb_private::SymbolFile {
+class SymbolFileSymtab : public lldb_private::SymbolFileActual {
   /// LLVM RTTI support.
   static char ID;
 
@@ -23,7 +23,7 @@
   /// LLVM RTTI support.
   /// \{
   bool isA(const void *ClassID) const override {
-    return ClassID == &ID || SymbolFile::isA(ClassID);
+    return ClassID == &ID || SymbolFileActual::isA(ClassID);
   }
   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
   /// \}
diff --git a/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp b/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp
--- a/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp
+++ b/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp
@@ -51,8 +51,8 @@
                                 lldb_private::TypeList &type_list) {}
 
 SymbolFileSymtab::SymbolFileSymtab(ObjectFileSP objfile_sp)
-    : SymbolFile(std::move(objfile_sp)), m_source_indexes(), m_func_indexes(),
-      m_code_indexes(), m_objc_class_name_to_index() {}
+    : SymbolFileActual(std::move(objfile_sp)), m_source_indexes(),
+      m_func_indexes(), m_code_indexes(), m_objc_class_name_to_index() {}
 
 uint32_t SymbolFileSymtab::CalculateAbilities() {
   uint32_t abilities = 0;
diff --git a/lldb/source/Symbol/CMakeLists.txt b/lldb/source/Symbol/CMakeLists.txt
--- a/lldb/source/Symbol/CMakeLists.txt
+++ b/lldb/source/Symbol/CMakeLists.txt
@@ -27,6 +27,7 @@
   Symbol.cpp
   SymbolContext.cpp
   SymbolFile.cpp
+  SymbolFileActual.cpp
   SymbolVendor.cpp
   Symtab.cpp
   Type.cpp
diff --git a/lldb/source/Symbol/SymbolFile.cpp b/lldb/source/Symbol/SymbolFile.cpp
--- a/lldb/source/Symbol/SymbolFile.cpp
+++ b/lldb/source/Symbol/SymbolFile.cpp
@@ -154,42 +154,6 @@
 #endif
 }
 
-uint32_t SymbolFile::GetNumCompileUnits() {
-  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
-  if (!m_compile_units) {
-    // Create an array of compile unit shared pointers -- which will each
-    // remain NULL until someone asks for the actual compile unit information.
-    m_compile_units.emplace(CalculateNumCompileUnits());
-  }
-  return m_compile_units->size();
-}
-
-CompUnitSP SymbolFile::GetCompileUnitAtIndex(uint32_t idx) {
-  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
-  uint32_t num = GetNumCompileUnits();
-  if (idx >= num)
-    return nullptr;
-  lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
-  if (!cu_sp)
-    cu_sp = ParseCompileUnitAtIndex(idx);
-  return cu_sp;
-}
-
-void SymbolFile::SetCompileUnitAtIndex(uint32_t idx, const CompUnitSP &cu_sp) {
-  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
-  const size_t num_compile_units = GetNumCompileUnits();
-  assert(idx < num_compile_units);
-  (void)num_compile_units;
-
-  // Fire off an assertion if this compile unit already exists for now. The
-  // partial parsing should take care of only setting the compile unit
-  // once, so if this assertion fails, we need to make sure that we don't
-  // have a race condition, or have a second parse of the same compile
-  // unit.
-  assert((*m_compile_units)[idx] == nullptr);
-  (*m_compile_units)[idx] = cu_sp;
-}
-
 Symtab *SymbolFile::GetSymtab() {
   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   if (m_symtab)
@@ -214,27 +178,6 @@
     m_symtab->SectionFileAddressesChanged();
 }
 
-void SymbolFile::Dump(Stream &s) {
-  s.Format("SymbolFile {0} ({1})\n", GetPluginName(),
-           GetMainObjectFile()->GetFileSpec());
-  s.PutCString("Types:\n");
-  m_type_list.Dump(&s, /*show_context*/ false);
-  s.PutChar('\n');
-
-  s.PutCString("Compile units:\n");
-  if (m_compile_units) {
-    for (const CompUnitSP &cu_sp : *m_compile_units) {
-      // We currently only dump the compile units that have been parsed
-      if (cu_sp)
-        cu_sp->Dump(&s, /*show_context*/ false);
-    }
-  }
-  s.PutChar('\n');
-
-  if (Symtab *symtab = GetSymtab())
-    symtab->Dump(&s, nullptr, eSortOrderNone);
-}
-
 SymbolFile::RegisterInfoResolver::~RegisterInfoResolver() = default;
 
 uint64_t SymbolFile::GetDebugInfoSize() {
diff --git a/lldb/source/Symbol/SymbolFileActual.cpp b/lldb/source/Symbol/SymbolFileActual.cpp
new file mode 100644
--- /dev/null
+++ b/lldb/source/Symbol/SymbolFileActual.cpp
@@ -0,0 +1,68 @@
+#include "lldb/Symbol/SymbolFileActual.h"
+
+#include "lldb/Symbol/CompileUnit.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Symbol/Symtab.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+char SymbolFileActual::ID;
+
+uint32_t SymbolFileActual::GetNumCompileUnits() {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
+  if (!m_compile_units) {
+    // Create an array of compile unit shared pointers -- which will each
+    // remain NULL until someone asks for the actual compile unit information.
+    m_compile_units.emplace(CalculateNumCompileUnits());
+  }
+  return m_compile_units->size();
+}
+
+CompUnitSP SymbolFileActual::GetCompileUnitAtIndex(uint32_t idx) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
+  uint32_t num = GetNumCompileUnits();
+  if (idx >= num)
+    return nullptr;
+  lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
+  if (!cu_sp)
+    cu_sp = ParseCompileUnitAtIndex(idx);
+  return cu_sp;
+}
+
+void SymbolFileActual::SetCompileUnitAtIndex(uint32_t idx,
+                                             const CompUnitSP &cu_sp) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
+  const size_t num_compile_units = GetNumCompileUnits();
+  assert(idx < num_compile_units);
+  (void)num_compile_units;
+
+  // Fire off an assertion if this compile unit already exists for now. The
+  // partial parsing should take care of only setting the compile unit
+  // once, so if this assertion fails, we need to make sure that we don't
+  // have a race condition, or have a second parse of the same compile
+  // unit.
+  assert((*m_compile_units)[idx] == nullptr);
+  (*m_compile_units)[idx] = cu_sp;
+}
+
+void SymbolFileActual::Dump(Stream &s) {
+  s.Format("SymbolFile {0} ({1})\n", GetPluginName(),
+           GetMainObjectFile()->GetFileSpec());
+  s.PutCString("Types:\n");
+  m_type_list.Dump(&s, /*show_context*/ false);
+  s.PutChar('\n');
+
+  s.PutCString("Compile units:\n");
+  if (m_compile_units) {
+    for (const CompUnitSP &cu_sp : *m_compile_units) {
+      // We currently only dump the compile units that have been parsed
+      if (cu_sp)
+        cu_sp->Dump(&s, /*show_context*/ false);
+    }
+  }
+  s.PutChar('\n');
+
+  if (Symtab *symtab = GetSymtab())
+    symtab->Dump(&s, nullptr, eSortOrderNone);
+}