diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParser.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParser.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParser.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParser.h
@@ -9,11 +9,12 @@
 #ifndef SymbolFileDWARF_DWARFASTParser_h_
 #define SymbolFileDWARF_DWARFASTParser_h_
 
+#include "DIERef.h"
 #include "DWARFDefines.h"
 #include "lldb/Core/PluginInterface.h"
-#include "lldb/Symbol/SymbolFile.h"
 #include "lldb/Symbol/CompilerDecl.h"
 #include "lldb/Symbol/CompilerDeclContext.h"
+#include "lldb/Symbol/SymbolFile.h"
 
 class DWARFDIE;
 namespace lldb_private {
@@ -39,7 +40,7 @@
                         lldb_private::CompilerType &compiler_type) = 0;
 
   virtual lldb_private::CompilerDecl
-  GetDeclForUIDFromDWARF(const DWARFDIE &die) = 0;
+  GetDeclForUIDFromDWARF(SymbolFileDWARF &dwarf, DIERef die_ref) = 0;
 
   virtual lldb_private::CompilerDeclContext
   GetDeclContextForUIDFromDWARF(const DWARFDIE &die) = 0;
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
@@ -36,7 +36,8 @@
 
 class DWARFASTParserClang : public DWARFASTParser {
 public:
-  DWARFASTParserClang(lldb_private::ClangASTContext &ast);
+  DWARFASTParserClang(lldb_private::ClangASTContext &ast,
+                      SymbolFileDWARF &dwarf);
 
   ~DWARFASTParserClang() override;
 
@@ -53,8 +54,8 @@
   CompleteTypeFromDWARF(const DWARFDIE &die, lldb_private::Type *type,
                         lldb_private::CompilerType &compiler_type) override;
 
-  lldb_private::CompilerDecl
-  GetDeclForUIDFromDWARF(const DWARFDIE &die) override;
+  lldb_private::CompilerDecl GetDeclForUIDFromDWARF(SymbolFileDWARF &dwarf,
+                                                    DIERef die_ref) override;
 
   void EnsureAllDIEsInDeclContextHaveBeenParsed(
       lldb_private::CompilerDeclContext decl_context) override;
@@ -83,6 +84,7 @@
   typedef llvm::DenseMap<const clang::Decl *, DIEPointerSet> DeclToDIEMap;
 
   lldb_private::ClangASTContext &m_ast;
+  SymbolFileDWARF &m_dwarf;
   DIEToDeclMap m_die_to_decl;
   DeclToDIEMap m_decl_to_die;
   DIEToDeclContextMap m_die_to_decl_ctx;
@@ -134,7 +136,7 @@
 
   lldb_private::Type *GetTypeForDIE(const DWARFDIE &die);
 
-  clang::Decl *GetClangDeclForDIE(const DWARFDIE &die);
+  clang::Decl *GetClangDeclForDIE(SymbolFileDWARF &dwarf, DIERef die_ref);
 
   clang::DeclContext *GetClangDeclContextForDIE(const DWARFDIE &die);
 
@@ -144,6 +146,7 @@
   bool CopyUniqueClassMethodTypes(const DWARFDIE &src_class_die,
                                   const DWARFDIE &dst_class_die,
                                   lldb_private::Type *class_type,
+                                  DWARFASTParserClang *dwarf_ast_parser,
                                   std::vector<DWARFDIE> &failures);
 
   clang::DeclContext *GetCachedClangDeclContextForDIE(const DWARFDIE &die);
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -55,8 +55,9 @@
 
 using namespace lldb;
 using namespace lldb_private;
-DWARFASTParserClang::DWARFASTParserClang(ClangASTContext &ast)
-    : m_ast(ast), m_die_to_decl_ctx(), m_decl_ctx_to_die() {}
+DWARFASTParserClang::DWARFASTParserClang(ClangASTContext &ast,
+                                         SymbolFileDWARF &dwarf)
+    : m_ast(ast), m_dwarf(dwarf), m_die_to_decl_ctx(), m_decl_ctx_to_die() {}
 
 DWARFASTParserClang::~DWARFASTParserClang() {}
 
@@ -135,43 +136,10 @@
   return false;
 }
 
-static DWARFDIE GetContainingClangModuleDIE(const DWARFDIE &die) {
-  if (die.IsValid()) {
-    DWARFDIE top_module_die;
-    // Now make sure this DIE is scoped in a DW_TAG_module tag and return true
-    // if so
-    for (DWARFDIE parent = die.GetParent(); parent.IsValid();
-         parent = parent.GetParent()) {
-      const dw_tag_t tag = parent.Tag();
-      if (tag == DW_TAG_module)
-        top_module_die = parent;
-      else if (tag == DW_TAG_compile_unit || tag == DW_TAG_partial_unit)
-        break;
-    }
-
-    return top_module_die;
-  }
-  return DWARFDIE();
-}
-
-static lldb::ModuleSP GetContainingClangModule(const DWARFDIE &die) {
-  if (die.IsValid()) {
-    DWARFDIE clang_module_die = GetContainingClangModuleDIE(die);
-
-    if (clang_module_die) {
-      const char *module_name = clang_module_die.GetName();
-      if (module_name)
-        return die.GetDWARF()->GetExternalModule(
-            lldb_private::ConstString(module_name));
-    }
-  }
-  return lldb::ModuleSP();
-}
-
 TypeSP DWARFASTParserClang::ParseTypeFromClangModule(const SymbolContext &sc,
                                                      const DWARFDIE &die,
                                                      Log *log) {
-  ModuleSP clang_module_sp = GetContainingClangModule(die);
+  const ModuleSP &clang_module_sp = sc.module_sp;
   if (!clang_module_sp)
     return TypeSP();
 
@@ -184,7 +152,8 @@
 
   // The type in the Clang module must have the same language as the current CU.
   LanguageSet languages;
-  languages.Insert(SymbolFileDWARF::GetLanguage(*die.GetCU()));
+  languages.Insert(!sc.comp_unit ? eLanguageTypeUnknown
+                                 : sc.comp_unit->GetLanguage());
   llvm::DenseSet<SymbolFile *> searched_symbol_files;
   clang_module_sp->GetSymbolFile()->FindTypes(decl_context, languages,
                                               searched_symbol_files, pcm_types);
@@ -193,7 +162,8 @@
     // by this symbol file, search all of them. Instead of calling
     // sym_file->FindTypes(), which would return this again, go straight
     // to the imported modules.
-    auto &sym_file = die.GetCU()->GetSymbolFileDWARF();
+    auto &sym_file =
+        static_cast<SymbolFileDWARF &>(*sc.module_sp->GetSymbolFile());
 
     // Well-formed clang modules never form cycles; guard against corrupted
     // ones by inserting the current file.
@@ -469,7 +439,8 @@
   CompilerType clang_type;
 
   TypeSP type_sp;
-  LanguageType cu_language = SymbolFileDWARF::GetLanguage(*die.GetCU());
+  LanguageType cu_language =
+      !sc.comp_unit ? eLanguageTypeUnknown : sc.comp_unit->GetLanguage();
   switch (tag) {
   case DW_TAG_typedef:
   case DW_TAG_base_type:
@@ -700,7 +671,8 @@
         return type_sp;
 
       DWARFDeclContext die_decl_ctx;
-      SymbolFileDWARF::GetDWARFDeclContext(die, die_decl_ctx);
+      die_decl_ctx.SetLanguage(cu_language);
+      die.GetDIE()->GetDWARFDeclContext(die.GetCU(), die_decl_ctx);
 
       type_sp = dwarf->FindDefinitionTypeForDWARFDeclContext(die_decl_ctx);
 
@@ -935,8 +907,10 @@
               if (class_type_die) {
                 std::vector<DWARFDIE> failures;
 
-                CopyUniqueClassMethodTypes(decl_ctx_die, class_type_die,
-                                           class_type, failures);
+                CopyUniqueClassMethodTypes(
+                    decl_ctx_die, class_type_die, class_type,
+                    (DWARFASTParserClang *)dwarf->GetDWARFParser(cu_language),
+                    failures);
 
                 // FIXME do something with these failures that's
                 // smarter than just dropping them on the ground.
@@ -1362,7 +1336,8 @@
   CompilerType clang_type;
   const dw_tag_t tag = die.Tag();
   SymbolFileDWARF *dwarf = die.GetDWARF();
-  LanguageType cu_language = SymbolFileDWARF::GetLanguage(*die.GetCU());
+  LanguageType cu_language =
+      !sc.comp_unit ? eLanguageTypeUnknown : sc.comp_unit->GetLanguage();
   Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_TYPE_COMPLETION |
                                           DWARF_LOG_LOOKUPS);
 
@@ -1495,7 +1470,8 @@
       return type_sp;
 
     DWARFDeclContext die_decl_ctx;
-    SymbolFileDWARF::GetDWARFDeclContext(die, die_decl_ctx);
+    die_decl_ctx.SetLanguage(cu_language);
+    die.GetDIE()->GetDWARFDeclContext(die.GetCU(), die_decl_ctx);
 
     // type_sp = FindDefinitionTypeForDIE (dwarf_cu, die,
     // type_name_const_str);
@@ -2240,12 +2216,17 @@
        it != m_decl_ctx_to_die.end() && it->first == opaque_decl_ctx;
        it = m_decl_ctx_to_die.erase(it))
     for (DWARFDIE decl = it->second.GetFirstChild(); decl;
-         decl = decl.GetSibling())
-      GetClangDeclForDIE(decl);
+         decl = decl.GetSibling()) {
+      llvm::Optional<DIERef> decl_ref = decl.GetDIERef();
+      if (!decl_ref)
+        continue;
+      GetClangDeclForDIE(m_dwarf, *decl_ref);
+    }
 }
 
-CompilerDecl DWARFASTParserClang::GetDeclForUIDFromDWARF(const DWARFDIE &die) {
-  clang::Decl *clang_decl = GetClangDeclForDIE(die);
+CompilerDecl DWARFASTParserClang::GetDeclForUIDFromDWARF(SymbolFileDWARF &dwarf,
+                                                         DIERef die_ref) {
+  clang::Decl *clang_decl = GetClangDeclForDIE(dwarf, die_ref);
   if (clang_decl != nullptr)
     return CompilerDecl(&m_ast, clang_decl);
   return CompilerDecl();
@@ -2424,11 +2405,9 @@
         func_name.SetValue(ConstString(mangled), true);
       else if ((die.GetParent().Tag() == DW_TAG_compile_unit ||
                 die.GetParent().Tag() == DW_TAG_partial_unit) &&
-               Language::LanguageIsCPlusPlus(
-                   SymbolFileDWARF::GetLanguage(*die.GetCU())) &&
-               !Language::LanguageIsObjC(
-                   SymbolFileDWARF::GetLanguage(*die.GetCU())) &&
-               name && strcmp(name, "main") != 0) {
+               Language::LanguageIsCPlusPlus(comp_unit.GetLanguage()) &&
+               !Language::LanguageIsObjC(comp_unit.GetLanguage()) && name &&
+               strcmp(name, "main") != 0) {
         // If the mangled name is not present in the DWARF, generate the
         // demangled name using the decl context. We skip if the function is
         // "main" as its name is never mangled.
@@ -2441,7 +2420,8 @@
         DWARFDeclContext decl_ctx;
         StreamString sstr;
 
-        SymbolFileDWARF::GetDWARFDeclContext(die, decl_ctx);
+        decl_ctx.SetLanguage(comp_unit.GetLanguage());
+        die.GetDIE()->GetDWARFDeclContext(die.GetCU(), decl_ctx);
         sstr << decl_ctx.GetQualifiedName();
 
         clang::DeclContext *containing_decl_ctx =
@@ -3356,7 +3336,9 @@
   return nullptr;
 }
 
-clang::Decl *DWARFASTParserClang::GetClangDeclForDIE(const DWARFDIE &die) {
+clang::Decl *DWARFASTParserClang::GetClangDeclForDIE(SymbolFileDWARF &dwarf,
+                                                     DIERef die_ref) {
+  DWARFDIE die = dwarf.GetDIE(die_ref);
   if (!die)
     return nullptr;
 
@@ -3376,7 +3358,10 @@
     return cache_pos->second;
 
   if (DWARFDIE spec_die = die.GetReferencedDIE(DW_AT_specification)) {
-    clang::Decl *decl = GetClangDeclForDIE(spec_die);
+    llvm::Optional<DIERef> spec_die_ref = spec_die.GetDIERef();
+    if (!spec_die_ref)
+      return nullptr;
+    clang::Decl *decl = GetClangDeclForDIE(dwarf, *spec_die_ref);
     m_die_to_decl[die.GetDIE()] = decl;
     m_decl_to_die[decl].insert(die.GetDIE());
     return decl;
@@ -3384,7 +3369,11 @@
 
   if (DWARFDIE abstract_origin_die =
           die.GetReferencedDIE(DW_AT_abstract_origin)) {
-    clang::Decl *decl = GetClangDeclForDIE(abstract_origin_die);
+    llvm::Optional<DIERef> abstract_origin_die_ref =
+        abstract_origin_die.GetDIERef();
+    if (!abstract_origin_die_ref)
+      return nullptr;
+    clang::Decl *decl = GetClangDeclForDIE(dwarf, *abstract_origin_die_ref);
     m_die_to_decl[die.GetDIE()] = decl;
     m_decl_to_die[decl].insert(die.GetDIE());
     return decl;
@@ -3395,13 +3384,12 @@
   case DW_TAG_variable:
   case DW_TAG_constant:
   case DW_TAG_formal_parameter: {
-    SymbolFileDWARF *dwarf = die.GetDWARF();
     Type *type = GetTypeForDIE(die);
-    if (dwarf && type) {
+    if (type) {
       const char *name = die.GetName();
       clang::DeclContext *decl_context =
           ClangASTContext::DeclContextGetAsDeclContext(
-              dwarf->GetDeclContextContainingUID(die.GetID()));
+              dwarf.GetDeclContextContainingUID(die.GetID()));
       decl = m_ast.CreateVariableDeclaration(
           decl_context, name,
           ClangUtil::GetQualType(type->GetForwardCompilerType()));
@@ -3409,14 +3397,16 @@
     break;
   }
   case DW_TAG_imported_declaration: {
-    SymbolFileDWARF *dwarf = die.GetDWARF();
-    DWARFDIE imported_uid = die.GetAttributeValueAsReferenceDIE(DW_AT_import);
-    if (imported_uid) {
-      CompilerDecl imported_decl = SymbolFileDWARF::GetDecl(imported_uid);
+    DWARFDIE imported_die = die.GetAttributeValueAsReferenceDIE(DW_AT_import);
+    if (imported_die) {
+      llvm::Optional<DIERef> imported_die_ref = imported_die.GetDIERef();
+      if (!imported_die_ref)
+        return nullptr;
+      CompilerDecl imported_decl = dwarf.GetDecl(*imported_die_ref);
       if (imported_decl) {
         clang::DeclContext *decl_context =
             ClangASTContext::DeclContextGetAsDeclContext(
-                dwarf->GetDeclContextContainingUID(die.GetID()));
+                dwarf.GetDeclContextContainingUID(die.GetID()));
         if (clang::NamedDecl *clang_imported_decl =
                 llvm::dyn_cast<clang::NamedDecl>(
                     (clang::Decl *)imported_decl.GetOpaqueDecl()))
@@ -3427,16 +3417,17 @@
     break;
   }
   case DW_TAG_imported_module: {
-    SymbolFileDWARF *dwarf = die.GetDWARF();
-    DWARFDIE imported_uid = die.GetAttributeValueAsReferenceDIE(DW_AT_import);
-
-    if (imported_uid) {
+    DWARFDIE imported_die = die.GetAttributeValueAsReferenceDIE(DW_AT_import);
+    if (imported_die) {
+      llvm::Optional<DIERef> imported_die_ref = imported_die.GetDIERef();
+      if (!imported_die_ref)
+        return nullptr;
       CompilerDeclContext imported_decl_ctx =
-          SymbolFileDWARF::GetDeclContext(imported_uid);
+          dwarf.GetDeclContext(*imported_die_ref);
       if (imported_decl_ctx) {
         clang::DeclContext *decl_context =
             ClangASTContext::DeclContextGetAsDeclContext(
-                dwarf->GetDeclContextContainingUID(die.GetID()));
+                dwarf.GetDeclContextContainingUID(die.GetID()));
         if (clang::NamespaceDecl *ns_decl =
                 ClangASTContext::DeclContextGetAsNamespaceDecl(
                     imported_decl_ctx))
@@ -3668,7 +3659,8 @@
 
 bool DWARFASTParserClang::CopyUniqueClassMethodTypes(
     const DWARFDIE &src_class_die, const DWARFDIE &dst_class_die,
-    lldb_private::Type *class_type, std::vector<DWARFDIE> &failures) {
+    lldb_private::Type *class_type, DWARFASTParserClang *dwarf_ast_parser,
+    std::vector<DWARFDIE> &failures) {
   if (!class_type || !src_class_die || !dst_class_die)
     return false;
   if (src_class_die.Tag() != dst_class_die.Tag())
@@ -3777,10 +3769,6 @@
     }
   }
 
-  DWARFASTParserClang *dwarf_ast_parser =
-      (DWARFASTParserClang *)SymbolFileDWARF::GetDWARFParser(*src_die.GetCU());
-  lldbassert(dwarf_ast_parser == (DWARFASTParserClang *)SymbolFileDWARF::GetDWARFParser(*dst_die.GetCU());
-
   // Now do the work of linking the DeclContexts and Types.
   if (fast_path) {
     // We can do this quickly.  Just run across the tables index-for-index
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp
@@ -36,7 +36,7 @@
 
   // Otherwise, we need to also check that the context matches. If it does not
   // match, we do nothing.
-  if (!SymbolFileDWARF::DIEInDeclContext(&parent_decl_ctx, die))
+  if (!dwarf.DIEInDeclContext(&parent_decl_ctx, die, ref))
     return;
 
   // In case of a full match, we just insert everything we find.
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
@@ -100,7 +100,8 @@
         unit.GetOffset());
   }
 
-  const LanguageType cu_language = SymbolFileDWARF::GetLanguage(unit);
+  const LanguageType cu_language =
+      SymbolFileDWARF::LanguageTypeFromDWARF(unit.GetDWARFLanguageType());
 
   IndexUnitImpl(unit, cu_language, set);
 
@@ -408,7 +409,7 @@
       DWARFDIE die = dwarf.GetDIE(die_ref);
       if (!die)
         continue;
-      if (SymbolFileDWARF::DIEInDeclContext(&parent_decl_ctx, die))
+      if (dwarf.DIEInDeclContext(&parent_decl_ctx, die, die_ref))
         dies.push_back(die);
     }
   }
@@ -419,7 +420,7 @@
       DWARFDIE die = dwarf.GetDIE(die_ref);
       if (!die)
         continue;
-      if (SymbolFileDWARF::DIEInDeclContext(&parent_decl_ctx, die))
+      if (dwarf.DIEInDeclContext(&parent_decl_ctx, die, die_ref))
         dies.push_back(die);
     }
     offsets.clear();
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
@@ -275,7 +275,9 @@
       return m_external_type_modules;
   }
 
-  virtual DWARFDIE GetDIE(const DIERef &die_ref);
+  virtual DWARFUnit *GetUnit(DIERef die_ref);
+
+  DWARFDIE GetDIE(DIERef die_ref);
 
   DWARFDIE GetDIE(lldb::user_id_t uid);
 
@@ -303,9 +305,9 @@
   /// If this is a DWARF object with a single CU, return its DW_AT_dwo_id.
   llvm::Optional<uint64_t> GetDWOId();
 
-  static bool
+  bool
   DIEInDeclContext(const lldb_private::CompilerDeclContext *parent_decl_ctx,
-                   const DWARFDIE &die);
+                   const DWARFDIE &die, DIERef die_ref);
 
   std::vector<std::unique_ptr<lldb_private::CallEdge>>
   ParseCallEdgesInFunction(UserID func_id) override;
@@ -318,26 +320,29 @@
 
   lldb_private::FileSpec GetFile(DWARFUnit &unit, size_t file_idx);
 
-  static llvm::Expected<lldb_private::TypeSystem &>
-  GetTypeSystem(DWARFUnit &unit);
+  lldb::LanguageType GetLanguage(DIERef die_ref);
+
+  DWARFASTParser *GetDWARFParser(lldb::LanguageType language);
+
+  DWARFASTParser *GetDWARFParser(DIERef die_ref);
 
-  static DWARFASTParser *GetDWARFParser(DWARFUnit &unit);
+  DWARFASTParser *GetDWARFParser(lldb::user_id_t die_uid,
+                                 DWARFDIE *die = nullptr);
 
   // CompilerDecl related functions
 
-  static lldb_private::CompilerDecl GetDecl(const DWARFDIE &die);
+  lldb_private::CompilerDecl GetDecl(lldb::user_id_t die_uid);
 
-  static lldb_private::CompilerDeclContext GetDeclContext(const DWARFDIE &die);
+  lldb_private::CompilerDecl GetDecl(DIERef die_ref);
 
-  static lldb_private::CompilerDeclContext
-  GetContainingDeclContext(const DWARFDIE &die);
+  lldb_private::CompilerDeclContext GetDeclContext(lldb::user_id_t die_uid);
 
-  static void GetDWARFDeclContext(const DWARFDIE &die,
-                                  DWARFDeclContext &dwarf_decl_ctx);
+  lldb_private::CompilerDeclContext GetDeclContext(DIERef die_ref);
 
-  static lldb::LanguageType LanguageTypeFromDWARF(uint64_t val);
+  lldb_private::CompilerDeclContext
+  GetContainingDeclContext(lldb::user_id_t die_uid);
 
-  static lldb::LanguageType GetLanguage(DWARFUnit &unit);
+  static lldb::LanguageType LanguageTypeFromDWARF(uint64_t val);
 
 protected:
   typedef llvm::DenseMap<const DWARFDebugInfoEntry *, lldb_private::Type *>
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
@@ -800,7 +800,7 @@
   if (!die.IsValid())
     return nullptr;
 
-  auto type_system_or_err = GetTypeSystemForLanguage(GetLanguage(*die.GetCU()));
+  auto type_system_or_err = GetTypeSystemForLanguage(comp_unit.GetLanguage());
   if (auto err = type_system_or_err.takeError()) {
     LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                    std::move(err), "Unable to parse function");
@@ -825,7 +825,7 @@
   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
   if (dwarf_cu)
-    return GetLanguage(*dwarf_cu);
+    return LanguageTypeFromDWARF(dwarf_cu->GetDWARFLanguageType());
   else
     return eLanguageTypeUnknown;
 }
@@ -1307,9 +1307,7 @@
   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
   // SymbolFileDWARF::GetDIE(). See comments inside the
   // SymbolFileDWARF::GetDIE() for details.
-  if (DWARFDIE die = GetDIE(type_uid))
-    return GetDecl(die);
-  return CompilerDecl();
+  return GetDecl(type_uid);
 }
 
 CompilerDeclContext
@@ -1320,9 +1318,7 @@
   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
   // SymbolFileDWARF::GetDIE(). See comments inside the
   // SymbolFileDWARF::GetDIE() for details.
-  if (DWARFDIE die = GetDIE(type_uid))
-    return GetDeclContext(die);
-  return CompilerDeclContext();
+  return GetDeclContext(type_uid);
 }
 
 CompilerDeclContext
@@ -1331,9 +1327,7 @@
   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
   // SymbolFileDWARF::GetDIE(). See comments inside the
   // SymbolFileDWARF::GetDIE() for details.
-  if (DWARFDIE die = GetDIE(type_uid))
-    return GetContainingDeclContext(die);
-  return CompilerDeclContext();
+  return GetContainingDeclContext(type_uid);
 }
 
 Type *SymbolFileDWARF::ResolveTypeUID(lldb::user_id_t type_uid) {
@@ -1445,8 +1439,9 @@
     return true;
   }
 
-  DWARFDIE dwarf_die = GetDIE(die_it->getSecond());
-  if (dwarf_die) {
+  DWARFDIE dwarf_die;
+  DWARFASTParser *dwarf_ast = GetDWARFParser(die_it->getSecond(), &dwarf_die);
+  if (dwarf_ast) {
     // Once we start resolving this type, remove it from the forward
     // declaration map in case anyone child members or other types require this
     // type to get resolved. The type will get resolved when all of the calls
@@ -1463,9 +1458,7 @@
           dwarf_die.GetID(), dwarf_die.GetTagAsCString(),
           type->GetName().AsCString());
     assert(compiler_type);
-    DWARFASTParser *dwarf_ast = GetDWARFParser(*dwarf_die.GetCU());
-    if (dwarf_ast)
-      return dwarf_ast->CompleteTypeFromDWARF(dwarf_die, type, compiler_type);
+    return dwarf_ast->CompleteTypeFromDWARF(dwarf_die, type, compiler_type);
   }
   return false;
 }
@@ -1538,20 +1531,27 @@
     return lldb::ModuleSP();
 }
 
-DWARFDIE
-SymbolFileDWARF::GetDIE(const DIERef &die_ref) {
+DWARFUnit *SymbolFileDWARF::GetUnit(DIERef die_ref) {
   if (die_ref.dwo_num()) {
     return DebugInfo()
         ->GetUnitAtIndex(*die_ref.dwo_num())
         ->GetDwoSymbolFile()
-        ->GetDIE(die_ref);
+        ->GetUnit(die_ref);
   }
 
   DWARFDebugInfo *debug_info = DebugInfo();
   if (debug_info)
-    return debug_info->GetDIE(die_ref);
+    return debug_info->GetUnit(die_ref);
   else
-    return DWARFDIE();
+    return nullptr;
+}
+
+DWARFDIE
+SymbolFileDWARF::GetDIE(DIERef die_ref) {
+  DWARFUnit *unit = GetUnit(die_ref);
+  if (!unit)
+    return {};
+  return unit->GetDIE(die_ref.die_offset());
 }
 
 /// Return the DW_AT_(GNU_)dwo_name.
@@ -2151,7 +2151,7 @@
           sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
 
           if (parent_decl_ctx) {
-            DWARFASTParser *dwarf_ast = GetDWARFParser(*die.GetCU());
+            DWARFASTParser *dwarf_ast = GetDWARFParser(die_ref);
             if (dwarf_ast) {
               CompilerDeclContext actual_parent_decl_ctx =
                   dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
@@ -2299,7 +2299,8 @@
 }
 
 bool SymbolFileDWARF::DIEInDeclContext(const CompilerDeclContext *decl_ctx,
-                                       const DWARFDIE &die) {
+                                       const DWARFDIE &die, DIERef die_ref) {
+  assert(die.GetOffset() == die_ref.die_offset());
   // If we have no parent decl context to match this DIE matches, and if the
   // parent decl context isn't valid, we aren't trying to look for any
   // particular decl context so any die matches.
@@ -2307,7 +2308,7 @@
     return true;
 
   if (die) {
-    DWARFASTParser *dwarf_ast = GetDWARFParser(*die.GetCU());
+    DWARFASTParser *dwarf_ast = GetDWARFParser(die_ref);
     if (dwarf_ast) {
       CompilerDeclContext actual_decl_ctx =
           dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
@@ -2482,7 +2483,7 @@
     const DIERef &die_ref = die_offsets[i];
     DWARFDIE die = GetDIE(die_ref);
     if (die) {
-      if (!DIEInDeclContext(parent_decl_ctx, die))
+      if (!DIEInDeclContext(parent_decl_ctx, die, die_ref))
         continue; // The containing decl contexts don't match
 
       Type *matching_type = ResolveType(die, true, true);
@@ -2558,7 +2559,7 @@
       m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
       continue;
     }
-    if (!languages[GetLanguage(*die.GetCU())])
+    if (!languages[GetLanguage(die_ref)])
       continue;
 
     llvm::SmallVector<CompilerContext, 4> die_context;
@@ -2612,10 +2613,10 @@
         DWARFDIE die = GetDIE(die_ref);
 
         if (die) {
-          if (!DIEInDeclContext(parent_decl_ctx, die))
+          if (!DIEInDeclContext(parent_decl_ctx, die, die_ref))
             continue; // The containing decl contexts don't match
 
-          DWARFASTParser *dwarf_ast = GetDWARFParser(*die.GetCU());
+          DWARFASTParser *dwarf_ast = GetDWARFParser(die_ref);
           if (dwarf_ast) {
             namespace_decl_ctx = dwarf_ast->GetDeclContextForUIDFromDWARF(die);
             if (namespace_decl_ctx)
@@ -2977,7 +2978,7 @@
             // looking for. We don't want to find a "Foo" type from Java if we
             // are looking for a "Foo" type for C, C++, ObjC, or ObjC++.
             if (type_system &&
-                !type_system->SupportsLanguage(GetLanguage(*type_die.GetCU())))
+                !type_system->SupportsLanguage(GetLanguage(die_ref)))
               continue;
             bool try_resolving_type = false;
 
@@ -3012,7 +3013,9 @@
 
             if (try_resolving_type) {
               DWARFDeclContext type_dwarf_decl_ctx;
-              GetDWARFDeclContext(type_die, type_dwarf_decl_ctx);
+              type_dwarf_decl_ctx.SetLanguage(dwarf_decl_ctx.GetLanguage());
+              type_die.GetDIE()->GetDWARFDeclContext(type_die.GetCU(),
+                                                     type_dwarf_decl_ctx);
 
               if (log) {
                 GetObjectFile()->GetModule()->LogMessage(
@@ -3062,7 +3065,8 @@
   if (!die)
     return {};
 
-  auto type_system_or_err = GetTypeSystemForLanguage(GetLanguage(*die.GetCU()));
+  auto type_system_or_err = GetTypeSystemForLanguage(
+      !sc.comp_unit ? eLanguageTypeUnknown : sc.comp_unit->GetLanguage());
   if (auto err = type_system_or_err.takeError()) {
     LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                    std::move(err), "Unable to parse type");
@@ -3426,10 +3430,14 @@
         // declaration context.
         if ((parent_tag == DW_TAG_compile_unit ||
              parent_tag == DW_TAG_partial_unit) &&
-            Language::LanguageIsCPlusPlus(GetLanguage(*die.GetCU()))) {
+            Language::LanguageIsCPlusPlus(!sc.comp_unit
+                                              ? eLanguageTypeUnknown
+                                              : sc.comp_unit->GetLanguage())) {
           DWARFDeclContext decl_ctx;
 
-          GetDWARFDeclContext(die, decl_ctx);
+          decl_ctx.SetLanguage(!sc.comp_unit ? eLanguageTypeUnknown
+                                             : sc.comp_unit->GetLanguage());
+          die.GetDIE()->GetDWARFDeclContext(die.GetCU(), decl_ctx);
           mangled = decl_ctx.GetQualifiedNameAsConstString().GetCString();
         }
       }
@@ -4002,12 +4010,8 @@
   return m_dwp_symfile.get();
 }
 
-llvm::Expected<TypeSystem &> SymbolFileDWARF::GetTypeSystem(DWARFUnit &unit) {
-  return unit.GetSymbolFileDWARF().GetTypeSystemForLanguage(GetLanguage(unit));
-}
-
-DWARFASTParser *SymbolFileDWARF::GetDWARFParser(DWARFUnit &unit) {
-  auto type_system_or_err = GetTypeSystem(unit);
+DWARFASTParser *SymbolFileDWARF::GetDWARFParser(LanguageType language) {
+  auto type_system_or_err = GetTypeSystemForLanguage(language);
   if (auto err = type_system_or_err.takeError()) {
     LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                    std::move(err), "Unable to get DWARFASTParser");
@@ -4016,39 +4020,70 @@
   return type_system_or_err->GetDWARFParser();
 }
 
-CompilerDecl SymbolFileDWARF::GetDecl(const DWARFDIE &die) {
-  DWARFASTParser *dwarf_ast = GetDWARFParser(*die.GetCU());
+DWARFASTParser *SymbolFileDWARF::GetDWARFParser(DIERef die_ref) {
+  return GetDWARFParser(GetLanguage(die_ref));
+}
+
+DWARFASTParser *SymbolFileDWARF::GetDWARFParser(user_id_t die_uid,
+                                                DWARFDIE *die) {
+  llvm::Optional<SymbolFileDWARF::DecodedUID> decoded = DecodeUID(die_uid);
+  if (!decoded)
+    return nullptr;
+  if (die) {
+    *die = decoded->dwarf.GetDIE(decoded->ref);
+    if (!*die)
+      return nullptr;
+  }
+  return decoded->dwarf.GetDWARFParser(decoded->ref);
+}
+
+CompilerDecl SymbolFileDWARF::GetDecl(lldb::user_id_t die_uid) {
+  llvm::Optional<SymbolFileDWARF::DecodedUID> decoded = DecodeUID(die_uid);
+  if (!decoded)
+    return {};
+  DWARFASTParser *dwarf_ast = decoded->dwarf.GetDWARFParser(decoded->ref);
+  if (dwarf_ast)
+    return dwarf_ast->GetDeclForUIDFromDWARF(decoded->dwarf, decoded->ref);
+  else
+    return CompilerDecl();
+}
+
+CompilerDecl SymbolFileDWARF::GetDecl(DIERef die_ref) {
+  DWARFASTParser *dwarf_ast = GetDWARFParser(die_ref);
   if (dwarf_ast)
-    return dwarf_ast->GetDeclForUIDFromDWARF(die);
+    return dwarf_ast->GetDeclForUIDFromDWARF(*this, die_ref);
   else
     return CompilerDecl();
 }
 
-CompilerDeclContext SymbolFileDWARF::GetDeclContext(const DWARFDIE &die) {
-  DWARFASTParser *dwarf_ast = GetDWARFParser(*die.GetCU());
+CompilerDeclContext SymbolFileDWARF::GetDeclContext(lldb::user_id_t die_uid) {
+  DWARFDIE die;
+  DWARFASTParser *dwarf_ast = GetDWARFParser(die_uid, &die);
   if (dwarf_ast)
     return dwarf_ast->GetDeclContextForUIDFromDWARF(die);
   else
     return CompilerDeclContext();
 }
 
-CompilerDeclContext
-SymbolFileDWARF::GetContainingDeclContext(const DWARFDIE &die) {
-  DWARFASTParser *dwarf_ast = GetDWARFParser(*die.GetCU());
+CompilerDeclContext SymbolFileDWARF::GetDeclContext(DIERef die_ref) {
+  DWARFDIE die = GetDIE(die_ref);
+  if (!die)
+    return {};
+  DWARFASTParser *dwarf_ast = GetDWARFParser(die_ref);
   if (dwarf_ast)
-    return dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
+    return dwarf_ast->GetDeclContextForUIDFromDWARF(die);
   else
     return CompilerDeclContext();
 }
 
-void SymbolFileDWARF::GetDWARFDeclContext(const DWARFDIE &die,
-                                          DWARFDeclContext &dwarf_decl_ctx) {
-  if (!die.IsValid()) {
-    dwarf_decl_ctx.Clear();
-    return;
-  }
-  dwarf_decl_ctx.SetLanguage(GetLanguage(*die.GetCU()));
-  die.GetDIE()->GetDWARFDeclContext(die.GetCU(), dwarf_decl_ctx);
+CompilerDeclContext
+SymbolFileDWARF::GetContainingDeclContext(lldb::user_id_t die_uid) {
+  DWARFDIE die;
+  DWARFASTParser *dwarf_ast = GetDWARFParser(die_uid, &die);
+  if (dwarf_ast)
+    return dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
+  else
+    return CompilerDeclContext();
 }
 
 LanguageType SymbolFileDWARF::LanguageTypeFromDWARF(uint64_t val) {
@@ -4064,6 +4099,9 @@
   }
 }
 
-LanguageType SymbolFileDWARF::GetLanguage(DWARFUnit &unit) {
-  return LanguageTypeFromDWARF(unit.GetDWARFLanguageType());
+LanguageType SymbolFileDWARF::GetLanguage(DIERef die_ref) {
+  DWARFUnit *unit = GetUnit(die_ref);
+  if (!unit)
+    return eLanguageTypeUnknown;
+  return LanguageTypeFromDWARF(unit->GetDWARFLanguageType());
 }
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
@@ -44,8 +44,7 @@
   llvm::Expected<lldb_private::TypeSystem &>
   GetTypeSystemForLanguage(lldb::LanguageType language) override;
 
-  DWARFDIE
-  GetDIE(const DIERef &die_ref) override;
+  DWARFUnit *GetUnit(DIERef die_ref) override;
 
   std::unique_ptr<SymbolFileDWARFDwo>
   GetDwoSymbolFileForCompileUnit(DWARFUnit &dwarf_cu,
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
@@ -147,9 +147,8 @@
   return GetBaseSymbolFile().GetTypeSystemForLanguage(language);
 }
 
-DWARFDIE
-SymbolFileDWARFDwo::GetDIE(const DIERef &die_ref) {
+DWARFUnit *SymbolFileDWARFDwo::GetUnit(DIERef die_ref) {
   if (*die_ref.dwo_num() == GetDwoNum())
-    return DebugInfo()->GetDIE(die_ref);
-  return GetBaseSymbolFile().GetDIE(die_ref);
+    return DebugInfo()->GetUnit(die_ref);
+  return GetBaseSymbolFile().GetUnit(die_ref);
 }
diff --git a/lldb/source/Symbol/ClangASTContext.cpp b/lldb/source/Symbol/ClangASTContext.cpp
--- a/lldb/source/Symbol/ClangASTContext.cpp
+++ b/lldb/source/Symbol/ClangASTContext.cpp
@@ -95,6 +95,7 @@
 
 #include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h"
 #include "Plugins/SymbolFile/DWARF/DWARFASTParserClang.h"
+#include "Plugins/SymbolFile/DWARF/SymbolFileDWARF.h"
 #include "Plugins/SymbolFile/PDB/PDBASTParser.h"
 
 #include <stdio.h>
@@ -9812,8 +9813,11 @@
 }
 
 DWARFASTParser *ClangASTContext::GetDWARFParser() {
-  if (!m_dwarf_ast_parser_up)
-    m_dwarf_ast_parser_up.reset(new DWARFASTParserClang(*this));
+  if (!m_dwarf_ast_parser_up) {
+    SymbolFileDWARF *dwarf = llvm::dyn_cast<SymbolFileDWARF>(m_sym_file);
+    if (dwarf)
+      m_dwarf_ast_parser_up.reset(new DWARFASTParserClang(*this, *dwarf));
+  }
   return m_dwarf_ast_parser_up.get();
 }
 
diff --git a/lldb/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp b/lldb/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
--- a/lldb/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
+++ b/lldb/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
@@ -48,7 +48,7 @@
 TEST_F(DWARFASTParserClangTests,
        EnsureAllDIEsInDeclContextHaveBeenParsedParsesOnlyMatchingEntries) {
   ClangASTContext ast_ctx;
-  DWARFASTParserClangStub ast_parser(ast_ctx);
+  DWARFASTParserClangStub ast_parser(ast_ctx, *(SymbolFileDWARF *)1LL);
 
   DWARFUnit *unit = nullptr;
   std::vector<DWARFDIE> dies = {DWARFDIE(unit, (DWARFDebugInfoEntry *)1LL),