Abstract the debug info parser from the ASTContext

[zturner]

Summary

ClangASTContext was assuming the presence of DWARF debug info, so it was baked into the class that DWARFASTParserClang would be used. This won't be the case with PDB, which will need a PDBASTParserClang. This will be used for PDB's generated by MSVC (since it is ABI compatible with clang-cl) as well as (in the future) PDBs generated directly by clang.

For now PDBASTParserClang is not implemented, this only breaks up the DWARFASTParser class into an abstraction that is not dwarf dependent, and has ClangASTContext deal only with this abstraction, while SymbolFileDWARF can deal directly with the DWARFASTParser.

[zturner]

Abandoning this for now, I ran into some difficulties when trying to implement the PDB version. Will have to resolve those first and then come back to this.

[zturner]

Re-opening this after an update. I had to move CanCompleteType, CompleteType, and LayoutRecordType implementations into another class (which I've called ClangTypeImportHelper, because PDB needed to use the exact same implementation.

[zturner]

ping, any objections here Greg?

[clayborg]

I need to speak with you about this and I do have objections. I made a ton of comments inline and as I started to understand what you were trying to do many objections changed, but I still have them. There is a ton of stuff in there and I would like to speak with you offline about this before I actually make my recommendation.

[zturner]

Abandoning this revision and will re-open a new revision.

include/lldb/Symbol/ClangASTContext.h

 
 // Project includes
 #include "Plugins/ExpressionParser/Clang/ClangPersistentVariables.h"
-#include "lldb/lldb-enumerations.h"
 #include "lldb/Core/ClangForward.h"
 #include "lldb/Core/ConstString.h"
 #include "lldb/Symbol/CompilerType.h"
+#include "lldb/Symbol/DebugInfoASTParser.h"
 #include "lldb/Symbol/TypeSystem.h"
+#include "lldb/lldb-enumerations.h"
 
 namespace lldb_private {
 

     //------------------------------------------------------------------
     // TypeSystem methods
     //------------------------------------------------------------------
-    DWARFASTParser *
-    GetDWARFParser () override;
+    DebugInfoASTParser *
+    GetDebugInfoASTParser() override;
 
     //------------------------------------------------------------------
     // ClangASTContext callbacks for external source lookups.

     //------------------------------------------------------------------
     // Classes that inherit from ClangASTContext can see and modify these
     //------------------------------------------------------------------
+    // clang-format off
     std::string                                     m_target_triple;
     std::unique_ptr<clang::ASTContext>              m_ast_ap;
     std::unique_ptr<clang::LangOptions>             m_language_options_ap;

     std::unique_ptr<clang::IdentifierTable>         m_identifier_table_ap;
     std::unique_ptr<clang::SelectorTable>           m_selector_table_ap;
     std::unique_ptr<clang::Builtin::Context>        m_builtins_ap;
-    std::unique_ptr<DWARFASTParser>                 m_dwarf_ast_parser_ap;
+    std::unique_ptr<DebugInfoASTParser>             m_di_ast_parser_ap;
     std::unique_ptr<ClangASTSource>                 m_scratch_ast_source_ap;
     std::unique_ptr<clang::MangleContext>           m_mangle_ctx_ap;
     CompleteTagDeclCallback                         m_callback_tag_decl;

     bool                                            m_ast_owned;
     bool                                            m_can_evaluate_expressions;
     std::map<void *, std::shared_ptr<void>>         m_decl_objects;
-
+    // clang-format on
 private:
     //------------------------------------------------------------------
     // For ClangASTContext only

include/lldb/Symbol/ClangTypeImportHelper.h

+//===-- ClangTypeImportHelper.h ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SYMBOL_CLANG_TYPE_IMPORT_HELPER_H
+#define LLDB_SYMBOL_CLANG_TYPE_IMPORT_HELPER_H
+
+#include "clang/AST/CharUnits.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+
+#include "lldb/Symbol/ClangASTImporter.h"
+
+#include "llvm/ADT/DenseMap.h"
+
+namespace lldb_private
+{
+
+class ClangASTImporter;
+
+class ClangTypeImportHelper
+{
+public:
+    struct LayoutInfo
+    {
+        LayoutInfo() : bit_size(0), alignment(0), field_offsets(), base_offsets(), vbase_offsets() {}
+        uint64_t bit_size;
+        uint64_t alignment;
+        llvm::DenseMap<const clang::FieldDecl *, uint64_t> field_offsets;
+        llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> base_offsets;
+        llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> vbase_offsets;
+    };
+
+    bool
+    CanCompleteType(const lldb_private::CompilerType &compiler_type, ClangASTImporter &importer);
+
+    bool
+    CompleteType(const lldb_private::CompilerType &compiler_type, ClangASTImporter &importer);
+
+    void
+    InsertRecordDecl(clang::RecordDecl *decl, const LayoutInfo &layout);
+
+    bool
+    LayoutRecordType(const clang::RecordDecl *record_decl, uint64_t &bit_size, uint64_t &alignment,
+                     llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
+                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
+                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets);
+
+private:
+    typedef llvm::DenseMap<const clang::RecordDecl *, LayoutInfo> RecordDeclToLayoutMap;
+
+    RecordDeclToLayoutMap m_record_decl_to_layout_map;
+};
+}
+
+#endif

include/lldb/Symbol/DebugInfoASTParser.h

+//===-- DebugInfoASTParser.h ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_INCLUDE_SYMBOL_DEBUGINFO_AST_PARSER_H
+#define LLDB_INCLUDE_SYMBOL_DEBUGINFO_AST_PARSER_H
+
+#include "lldb/Symbol/CompilerType.h"
+#include "lldb/Symbol/SymbolFile.h"
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/Casting.h"
+
+#include "clang/AST/CharUnits.h"
+
+#define DECLARE_DEBUG_INFO_PARSER_TYPE(TypeValue)                                                                      \
+    static const lldb_private::SymbolFileFormat type = TypeValue;                                                      \
+    lldb_private::SymbolFileFormat GetDebugInfoFormat() const override { return TypeValue; }                           \
+    static bool classof(const DebugInfoASTParser *parser) { return parser->GetDebugInfoFormat() == type; }
+
+class DebugInfoASTParser
+{
+public:
+    virtual ~DebugInfoASTParser() {}
+
+    virtual lldb_private::SymbolFileFormat
+    GetDebugInfoFormat() const = 0;
+
+    virtual bool
+    CanCompleteType(const lldb_private::CompilerType &compiler_type)
+    {
+        return false;
+    }
+
+    virtual bool
+    CompleteType(const lldb_private::CompilerType &compiler_type)
+    {
+        return false;
+    }
+
+    virtual bool
+    LayoutRecordType(const clang::RecordDecl *record_decl, uint64_t &bit_size, uint64_t &alignment,
+                     llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
+                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
+                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
+    {
+        return false;
+    }
+};
+
+#endif // LLDB_INCLUDE_SYMBOL_DEBUGINFO_AST_PARSER_H

include/lldb/Symbol/GoASTContext.h

 #include "lldb/Core/ConstString.h"
 #include "lldb/Symbol/TypeSystem.h"
 #include "lldb/Symbol/CompilerType.h"
+class DWARFASTParser;
 
 namespace lldb_private
 {

 
     static void
     Terminate ();
-    
-    DWARFASTParser *GetDWARFParser() override;
+    DebugInfoASTParser *
+    GetDebugInfoASTParser() override;
 
     void
     SetAddressByteSize(int byte_size)

include/lldb/Symbol/JavaASTContext.h

 #include "lldb/Core/ConstString.h"
 #include "lldb/Symbol/TypeSystem.h"
 
+class DWARFASTParser;
+
 namespace lldb_private
 {
 

     static void
     Terminate();
 
-    DWARFASTParser *
-    GetDWARFParser() override;
+    DebugInfoASTParser *
+    GetDebugInfoASTParser() override;
 
     uint32_t
     GetPointerByteSize() override;

include/lldb/Symbol/SymbolFile.h

 
 namespace lldb_private {
 
+enum class SymbolFileFormat
+{
+    DWARF,
+    PDB,
+    Other
+};
+
 class SymbolFile :
     public PluginInterface
 {

     //------------------------------------------------------------------    
     virtual void            InitializeObject() {}
 
+    virtual SymbolFileFormat
+    GetSymbolFileFormat() const
+    {
+        return SymbolFileFormat::Other;
+    }
+
     //------------------------------------------------------------------
     // Compile Unit function calls
     //------------------------------------------------------------------

                                       lldb_private::TypeList &type_list) = 0;
 
     virtual lldb_private::TypeSystem *
-                            GetTypeSystemForLanguage (lldb::LanguageType language);
+    GetTypeSystemForLanguage(lldb::LanguageType language);
 
     virtual CompilerDeclContext
-                            FindNamespace (const SymbolContext& sc, 
-                                           const ConstString &name,
-                                           const CompilerDeclContext *parent_decl_ctx)
+    FindNamespace(const SymbolContext &sc, const ConstString &name, const CompilerDeclContext *parent_decl_ctx)
     {
         return CompilerDeclContext();
     }

include/lldb/Symbol/TypeSystem.h

 #include "lldb/Symbol/CompilerDecl.h"
 #include "lldb/Symbol/CompilerDeclContext.h"
 
-class DWARFDIE;
-class DWARFASTParser;
+class DebugInfoASTParser;
 
 namespace lldb_private {
     

     virtual void
     Finalize() {}
 
-    virtual DWARFASTParser *
-    GetDWARFParser ()
+    virtual DebugInfoASTParser *
+    GetDebugInfoASTParser()
     {
         return nullptr;
     }

source/Plugins/SymbolFile/DWARF/DWARFASTParser.h

 #include "lldb/Core/PluginInterface.h"
 #include "lldb/Symbol/CompilerDecl.h"
 #include "lldb/Symbol/CompilerDeclContext.h"
+#include "lldb/Symbol/DebugInfoASTParser.h"
 
 class DWARFDIE;
 
-class DWARFASTParser
+class DWARFASTParser : public DebugInfoASTParser
 {
 public:
     virtual ~DWARFASTParser() {}
 
+    DECLARE_DEBUG_INFO_PARSER_TYPE(lldb_private::SymbolFileFormat::DWARF)
+
     virtual lldb::TypeSP
     ParseTypeFromDWARF (const lldb_private::SymbolContext& sc,
                         const DWARFDIE &die,

                             const DWARFDIE &die) = 0;
 
     virtual bool
-    CanCompleteType (const lldb_private::CompilerType &compiler_type)
-    {
-        return false;
-    }
-
-    virtual bool
-    CompleteType (const lldb_private::CompilerType &compiler_type)
-    {
-        return false;
-    }
-
-    virtual bool
     CompleteTypeFromDWARF (const DWARFDIE &die,
                            lldb_private::Type *type,
                            lldb_private::CompilerType &compiler_type) = 0;

source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h

 #include "clang/AST/CharUnits.h"
 
 // Project includes
+#include "DWARFASTParser.h"
+#include "DWARFDefines.h"
 #include "lldb/Core/ClangForward.h"
 #include "lldb/Core/PluginInterface.h"
 #include "lldb/Symbol/ClangASTContext.h"
-#include "DWARFDefines.h"
-#include "DWARFASTParser.h"
+#include "lldb/Symbol/ClangTypeImportHelper.h"
 
 class DWARFDebugInfoEntry;
 class DWARFDIECollection;

 
     ~DWARFASTParserClang() override;
 
-    lldb::TypeSP
-    ParseTypeFromDWARF (const lldb_private::SymbolContext& sc,
-                        const DWARFDIE &die,
-                        lldb_private::Log *log,
-                        bool *type_is_new_ptr) override;
-
-
-    lldb_private::Function *
-    ParseFunctionFromDWARF (const lldb_private::SymbolContext& sc,
-                            const DWARFDIE &die) override;
-
+    // DebugInfoASTParser interface
     bool
     CanCompleteType (const lldb_private::CompilerType &compiler_type) override;
 

     CompleteType (const lldb_private::CompilerType &compiler_type) override;
 
     bool
-    CompleteTypeFromDWARF (const DWARFDIE &die,
-                           lldb_private::Type *type,
-                           lldb_private::CompilerType &compiler_type) override;
+    LayoutRecordType(const clang::RecordDecl *record_decl, uint64_t &bit_size, uint64_t &alignment,
+                     llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
+                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
+                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets) override;
+
+    // DWARFASTParser interface.
+    lldb::TypeSP
+    ParseTypeFromDWARF(const lldb_private::SymbolContext &sc, const DWARFDIE &die, lldb_private::Log *log,
+                       bool *type_is_new_ptr) override;
+
+    lldb_private::Function *
+    ParseFunctionFromDWARF(const lldb_private::SymbolContext &sc, const DWARFDIE &die) override;
+
+    bool
+    CompleteTypeFromDWARF(const DWARFDIE &die, lldb_private::Type *type,
+                          lldb_private::CompilerType &compiler_type) override;
 
     lldb_private::CompilerDecl
     GetDeclForUIDFromDWARF (const DWARFDIE &die) override;

     lldb_private::CompilerDeclContext
     GetDeclContextContainingUIDFromDWARF (const DWARFDIE &die) override;
 
-    bool
-    LayoutRecordType(const clang::RecordDecl *record_decl,
-                     uint64_t &bit_size,
-                     uint64_t &alignment,
-                     llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
-                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
-                     llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets);
-
 protected:
     class DelayedAddObjCClassProperty;
     typedef std::vector <DelayedAddObjCClassProperty> DelayedPropertyList;
 
-    struct LayoutInfo
-    {
-        LayoutInfo () :
-        bit_size(0),
-        alignment(0),
-        field_offsets(),
-        base_offsets(),
-        vbase_offsets()
-        {
-        }
-        uint64_t bit_size;
-        uint64_t alignment;
-        llvm::DenseMap<const clang::FieldDecl *, uint64_t> field_offsets;
-        llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> base_offsets;
-        llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> vbase_offsets;
-    };
-
     clang::BlockDecl *
     ResolveBlockDIE (const DWARFDIE &die);
 
     clang::NamespaceDecl *
     ResolveNamespaceDIE (const DWARFDIE &die);
 
-    typedef llvm::DenseMap<const clang::RecordDecl *, LayoutInfo> RecordDeclToLayoutMap;
-
     bool
     ParseTemplateDIE (const DWARFDIE &die,
                       lldb_private::ClangASTContext::TemplateParameterInfos &template_param_infos);

                                  lldb_private::ClangASTContext::TemplateParameterInfos &template_param_infos);
 
     bool
-    ParseChildMembers (const lldb_private::SymbolContext& sc,
-                       const DWARFDIE &die,
-                       lldb_private::CompilerType &class_compiler_type,
-                       const lldb::LanguageType class_language,
-                       std::vector<clang::CXXBaseSpecifier *>& base_classes,
-                       std::vector<int>& member_accessibilities,
-                       DWARFDIECollection& member_function_dies,
-                       DelayedPropertyList& delayed_properties,
-                       lldb::AccessType &default_accessibility,
-                       bool &is_a_class,
-                       LayoutInfo &layout_info);
+    ParseChildMembers(const lldb_private::SymbolContext &sc, const DWARFDIE &die,
+                      lldb_private::CompilerType &class_compiler_type, const lldb::LanguageType class_language,
+                      std::vector<clang::CXXBaseSpecifier *> &base_classes, std::vector<int> &member_accessibilities,
+                      DWARFDIECollection &member_function_dies, DelayedPropertyList &delayed_properties,
+                      lldb::AccessType &default_accessibility, bool &is_a_class,
+                      lldb_private::ClangTypeImportHelper::LayoutInfo &layout_info);
 
     size_t
     ParseChildParameters (const lldb_private::SymbolContext& sc,

     DeclToDIEMap m_decl_to_die;
     DIEToDeclContextMap m_die_to_decl_ctx;
     DeclContextToDIEMap m_decl_ctx_to_die;
-    RecordDeclToLayoutMap m_record_decl_to_layout_map;
+    lldb_private::ClangTypeImportHelper m_type_import_helper;
     std::unique_ptr<lldb_private::ClangASTImporter> m_clang_ast_importer_ap;
 };
 

source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

 DWARFASTParserClang::GetClangASTImporter()
 {
     if (!m_clang_ast_importer_ap)
-    {
         m_clang_ast_importer_ap.reset (new ClangASTImporter);
-    }
     return *m_clang_ast_importer_ap;
 }
 

                                 clang::RecordDecl *record_decl = ClangASTContext::GetAsRecordDecl(clang_type);
 
                                 if (record_decl)
-                                    m_record_decl_to_layout_map.insert(std::make_pair(record_decl, LayoutInfo()));
+                                    m_type_import_helper.InsertRecordDecl(record_decl,
+                                                                          ClangTypeImportHelper::LayoutInfo());
                             }
                         }
                         else if (clang_type_was_created)

 bool
 DWARFASTParserClang::CanCompleteType (const lldb_private::CompilerType &compiler_type)
 {
-    if (m_clang_ast_importer_ap)
-        return ClangASTContext::CanImport(compiler_type, GetClangASTImporter());
-    else
-        return false;
+    return m_type_import_helper.CanCompleteType(compiler_type, GetClangASTImporter());
 }
 
 bool
 DWARFASTParserClang::CompleteType (const lldb_private::CompilerType &compiler_type)
 {
-    if (CanCompleteType(compiler_type))
-    {
-        if (ClangASTContext::Import(compiler_type, GetClangASTImporter()))
-        {
-            ClangASTContext::CompleteTagDeclarationDefinition(compiler_type);
-            return true;
-        }
-        else
-        {
-            ClangASTContext::SetHasExternalStorage (compiler_type.GetOpaqueQualType(), false);
-        }
-    }
-    return false;
+    return m_type_import_helper.CompleteType(compiler_type, GetClangASTImporter());
 }
 
 bool
-DWARFASTParserClang::CompleteTypeFromDWARF (const DWARFDIE &die,
-                                            lldb_private::Type *type,
-                                            CompilerType &clang_type)
+DWARFASTParserClang::LayoutRecordType(const clang::RecordDecl *record_decl, uint64_t &bit_size, uint64_t &alignment,
+                                      llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
+                                      llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
+                                      llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
+{
+    return m_type_import_helper.LayoutRecordType(record_decl, bit_size, alignment, field_offsets, base_offsets,
+                                                 vbase_offsets);
+}
+
+bool
+DWARFASTParserClang::CompleteTypeFromDWARF(const DWARFDIE &die, lldb_private::Type *type, CompilerType &clang_type)
 {
     SymbolFileDWARF *dwarf = die.GetDWARF();
 

         case DW_TAG_union_type:
         case DW_TAG_class_type:
         {
-            LayoutInfo layout_info;
+            ClangTypeImportHelper::LayoutInfo layout_info;
 
             {
                 if (die.HasChildren())

 
                         }
                     }
-                    m_record_decl_to_layout_map.insert(std::make_pair(record_decl, layout_info));
+                    m_type_import_helper.InsertRecordDecl(record_decl, layout_info);
                 }
             }
         }

     return NULL;
 }
 
-
 bool
-DWARFASTParserClang::ParseChildMembers (const SymbolContext& sc,
-                                        const DWARFDIE &parent_die,
-                                        CompilerType &class_clang_type,
-                                        const LanguageType class_language,
-                                        std::vector<clang::CXXBaseSpecifier *>& base_classes,
-                                        std::vector<int>& member_accessibilities,
-                                        DWARFDIECollection& member_function_dies,
-                                        DelayedPropertyList& delayed_properties,
-                                        AccessType& default_accessibility,
-                                        bool &is_a_class,
-                                        LayoutInfo &layout_info)
+DWARFASTParserClang::ParseChildMembers(const SymbolContext &sc, const DWARFDIE &parent_die,
+                                       CompilerType &class_clang_type, const LanguageType class_language,
+                                       std::vector<clang::CXXBaseSpecifier *> &base_classes,
+                                       std::vector<int> &member_accessibilities,
+                                       DWARFDIECollection &member_function_dies,
+                                       DelayedPropertyList &delayed_properties, AccessType &default_accessibility,
+                                       bool &is_a_class, ClangTypeImportHelper::LayoutInfo &layout_info)
 {
     if (!parent_die)
         return 0;

     return (failures.Size() != 0);
 }
 
-
-bool
-DWARFASTParserClang::LayoutRecordType(const clang::RecordDecl *record_decl,
-                                      uint64_t &bit_size,
-                                      uint64_t &alignment,
-                                      llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
-                                      llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
-                                      llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
-{
-    RecordDeclToLayoutMap::iterator pos = m_record_decl_to_layout_map.find (record_decl);
-    bool success = false;
-    base_offsets.clear();
-    vbase_offsets.clear();
-    if (pos != m_record_decl_to_layout_map.end())
-    {
-        bit_size = pos->second.bit_size;
-        alignment = pos->second.alignment;
-        field_offsets.swap(pos->second.field_offsets);
-        base_offsets.swap (pos->second.base_offsets);
-        vbase_offsets.swap (pos->second.vbase_offsets);
-        m_record_decl_to_layout_map.erase(pos);
-        success = true;
-    }
-    else
-    {
-        bit_size = 0;
-        alignment = 0;
-        field_offsets.clear();
-    }
-    return success;
-}

source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp

 
 #include "DWARFDIE.h"
 
+#include "DWARFASTParser.h"
 #include "DWARFCompileUnit.h"
+#include "DWARFDIECollection.h"
 #include "DWARFDebugAbbrev.h"
 #include "DWARFDebugAranges.h"
 #include "DWARFDebugInfo.h"
 #include "DWARFDebugInfoEntry.h"
 #include "DWARFDebugRanges.h"
 #include "DWARFDeclContext.h"
-#include "DWARFDIECollection.h"
 #include "DWARFFormValue.h"
 #include "SymbolFileDWARF.h"
 
 #include "lldb/Core/Module.h"
+#include "lldb/Symbol/DebugInfoASTParser.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Symbol/Type.h"
 #include "lldb/Symbol/TypeSystem.h"

 {
     lldb_private::TypeSystem *type_system = GetTypeSystem ();
     if (type_system)
-        return type_system->GetDWARFParser();
+        return llvm::dyn_cast<DWARFASTParser>(type_system->GetDebugInfoASTParser());
     else
         return nullptr;
 }

source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h

     void
     InitializeObject() override;
 
+    lldb_private::SymbolFileFormat
+    GetSymbolFileFormat() const override;
+
     //------------------------------------------------------------------
     // Compile Unit function calls
     //------------------------------------------------------------------

                    const lldb_private::ConstString &name,
                    const lldb_private::CompilerDeclContext *parent_decl_ctx) override;
 
-
     //------------------------------------------------------------------
     // PluginInterface protocol
     //------------------------------------------------------------------

source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

     }
 }
 
+SymbolFileFormat
+SymbolFileDWARF::GetSymbolFileFormat() const
+{
+    return SymbolFileFormat::DWARF;
+}
+
 bool
 SymbolFileDWARF::SupportedVersion(uint16_t version)
 {

 
         if (type_system)
         {
-            DWARFASTParser *dwarf_ast = type_system->GetDWARFParser();
+            DWARFASTParser *dwarf_ast = llvm::dyn_cast_or_null<DWARFASTParser>(type_system->GetDebugInfoASTParser());
             if (dwarf_ast)
                 return dwarf_ast->ParseFunctionFromDWARF(sc, die);
         }

 SymbolFileDWARF::ParseDeclsForContext (CompilerDeclContext decl_ctx)
 {
     TypeSystem *type_system = decl_ctx.GetTypeSystem();
-    DWARFASTParser *ast_parser = type_system->GetDWARFParser();
+    DWARFASTParser *ast_parser = llvm::dyn_cast_or_null<DWARFASTParser>(type_system->GetDebugInfoASTParser());
     std::vector<DWARFDIE> decl_ctx_die_list = ast_parser->GetDIEForDeclContext(decl_ctx);
 
     for (DWARFDIE decl_ctx_die : decl_ctx_die_list)

     TypeSystem *type_system = compiler_type.GetTypeSystem();
     if (type_system)
     {
-        DWARFASTParser *dwarf_ast = type_system->GetDWARFParser();
-        if (dwarf_ast)
-            return dwarf_ast->CanCompleteType(compiler_type);
+        DebugInfoASTParser *ast_parser = type_system->GetDebugInfoASTParser();
+        if (ast_parser)
+            return ast_parser->CanCompleteType(compiler_type);
     }
     return false;
 }

     TypeSystem *type_system = compiler_type.GetTypeSystem();
     if (type_system)
     {
-        DWARFASTParser *dwarf_ast = type_system->GetDWARFParser();
+        DebugInfoASTParser *dwarf_ast = type_system->GetDebugInfoASTParser();
         if (dwarf_ast && dwarf_ast->CanCompleteType(compiler_type))
             return dwarf_ast->CompleteType(compiler_type);
     }

 
         if (type_system)
         {
-            DWARFASTParser *dwarf_ast = type_system->GetDWARFParser();
+            DWARFASTParser *dwarf_ast = llvm::dyn_cast_or_null<DWARFASTParser>(type_system->GetDebugInfoASTParser());
             if (dwarf_ast)
             {
                 Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);

source/Plugins/SymbolFile/PDB/SymbolFilePDB.h

     void
     InitializeObject() override;
 
+    lldb_private::SymbolFileFormat
+    GetSymbolFileFormat() const override;
+
     //------------------------------------------------------------------
     // Compile Unit function calls
     //------------------------------------------------------------------

source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp

     m_session_up->setLoadAddress(obj_load_address);
 }
 
+lldb_private::SymbolFileFormat
+SymbolFilePDB::GetSymbolFileFormat() const
+{
+    return SymbolFileFormat::PDB;
+}
+
 uint32_t
 SymbolFilePDB::GetNumCompileUnits()
 {

source/Symbol/CMakeLists.txt

   ClangASTImporter.cpp
   ClangExternalASTSourceCallbacks.cpp
   ClangExternalASTSourceCommon.cpp
+  ClangTypeImportHelper.cpp
   CompilerDecl.cpp
   CompilerDeclContext.cpp
   CompilerType.cpp

source/Symbol/ClangASTContext.cpp

     }
 }
 
-
-DWARFASTParser *
-ClangASTContext::GetDWARFParser ()
+DebugInfoASTParser *
+ClangASTContext::GetDebugInfoASTParser()
 {
-    if (!m_dwarf_ast_parser_ap)
-        m_dwarf_ast_parser_ap.reset(new DWARFASTParserClang(*this));
-    return m_dwarf_ast_parser_ap.get();
+    if (!m_di_ast_parser_ap)
+    {
+        if (m_sym_file->GetSymbolFileFormat() == SymbolFileFormat::DWARF)
+            m_di_ast_parser_ap.reset(new DWARFASTParserClang(*this));
+    }
+    return m_di_ast_parser_ap.get();
 }
 
-
 bool
 ClangASTContext::LayoutRecordType(void *baton,
                                   const clang::RecordDecl *record_decl,

                                   llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
 {
     ClangASTContext *ast = (ClangASTContext *)baton;
-    DWARFASTParserClang *dwarf_ast_parser = (DWARFASTParserClang *)ast->GetDWARFParser();
-    return dwarf_ast_parser->LayoutRecordType(record_decl, bit_size, alignment, field_offsets, base_offsets, vbase_offsets);
+    DebugInfoASTParser *di_ast_parser = ast->GetDebugInfoASTParser();
+    return di_ast_parser->LayoutRecordType(record_decl, bit_size, alignment, field_offsets, base_offsets,
+                                           vbase_offsets);
 }
 
 //----------------------------------------------------------------------

source/Symbol/ClangTypeImportHelper.cpp

+//===-- ClangTypeImportHelper.cpp -------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Symbol/ClangTypeImportHelper.h"
+#include "lldb/Symbol/ClangASTContext.h"
+#include "lldb/Symbol/ClangASTImporter.h"
+
+using namespace lldb_private;
+
+bool
+ClangTypeImportHelper::CanCompleteType(const CompilerType &compiler_type, ClangASTImporter &importer)
+{
+    return ClangASTContext::CanImport(compiler_type, importer);
+}
+
+bool
+ClangTypeImportHelper::CompleteType(const CompilerType &compiler_type, ClangASTImporter &importer)
+{
+    if (!CanCompleteType(compiler_type, importer))
+        return false;
+
+    if (ClangASTContext::Import(compiler_type, importer))
+    {
+        ClangASTContext::CompleteTagDeclarationDefinition(compiler_type);
+        return true;
+    }
+
+    ClangASTContext::SetHasExternalStorage(compiler_type.GetOpaqueQualType(), false);
+    return false;
+}
+
+bool
+ClangTypeImportHelper::LayoutRecordType(const clang::RecordDecl *record_decl, uint64_t &bit_size, uint64_t &alignment,
+                                        llvm::DenseMap<const clang::FieldDecl *, uint64_t> &field_offsets,
+                                        llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
+                                        llvm::DenseMap<const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
+{
+    RecordDeclToLayoutMap::iterator pos = m_record_decl_to_layout_map.find(record_decl);
+    bool success = false;
+    base_offsets.clear();
+    vbase_offsets.clear();
+    if (pos != m_record_decl_to_layout_map.end())
+    {
+        bit_size = pos->second.bit_size;
+        alignment = pos->second.alignment;
+        field_offsets.swap(pos->second.field_offsets);
+        base_offsets.swap(pos->second.base_offsets);
+        vbase_offsets.swap(pos->second.vbase_offsets);
+        m_record_decl_to_layout_map.erase(pos);
+        success = true;
+    }
+    else
+    {
+        bit_size = 0;
+        alignment = 0;
+        field_offsets.clear();
+    }
+    return success;
+}
+
+void
+ClangTypeImportHelper::InsertRecordDecl(clang::RecordDecl *decl, const LayoutInfo &layout)
+{
+    m_record_decl_to_layout_map.insert(std::make_pair(decl, layout));
+}
 No newline at end of file

source/Symbol/GoASTContext.cpp

     return (kind & GoType::KIND_DIRECT_IFACE) == GoType::KIND_DIRECT_IFACE;
 }
 
-DWARFASTParser *
-GoASTContext::GetDWARFParser()
+DebugInfoASTParser *
+GoASTContext::GetDebugInfoASTParser()
 {
     if (!m_dwarf_ast_parser_ap)
         m_dwarf_ast_parser_ap.reset(new DWARFASTParserGo(*this));

source/Symbol/JavaASTContext.cpp

     return m_pointer_byte_size;
 }
 
-DWARFASTParser *
-JavaASTContext::GetDWARFParser()
+DebugInfoASTParser *
+JavaASTContext::GetDebugInfoASTParser()
 {
     if (!m_dwarf_ast_parser_ap)
         m_dwarf_ast_parser_ap.reset(new DWARFASTParserJava(*this));