DWARFASTParserClang: Move attribute parsing into a single function

[labath]

Summary

The ParseTypeFromDWARF function consists of a huge switch on the kind of
type being parsed. Each case in this switch starts with parsing the
attributes of the current DIE. A lot of these attributes are specific to
one kind of a type, but a lot of them are common too, leading to code
duplication.

This patch reduces the duplication (and the size of ParseTypeFromDWARF)
by moving the attribute parsing to a separate function. It creates a
struct (ParsedTypeAttributes), which contains a parsed form of all
attributes which are useful for parsing any kind of a type. The parsing
code for a specific type kind can then access the fields which are
relevant for that specific case.

[labath]

• also include DW_AT_signature in the attribute list to increase consistency and avoid iterating over the attribute list twice.

[clayborg]

Minor nit where we are storing name a ConstString but mangled name as "const char *". Fix if needed.

Would be good to verify performance doesn't regress from this somehow. Maybe having a large DWARF file with many types and accessing each type and making sure it is completed via the external AST.

source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

248

Why is this stored as a "const char *" and "name" below as a ConstString?

[labath]

In D62477#1519318, @clayborg wrote:

Would be good to verify performance doesn't regress from this somehow. Maybe having a large DWARF file with many types and accessing each type and making sure it is completed via the external AST.

I tried to measure this by calling ParseTypes for each compile unit in a loop. If anything, the readings seem to indicate that the new version is faster (which is possible because we now don't iterate the attribute list twice to search for DW_AT_signature). However, the readings were pretty inconsistent even for identical runs, so this is most likely just noise.

TBH, I'd be surprised if this affects the performance in any way because there is so much other work being done while parsing/completing a type, and this only changes how we iterate over the attribute list. And the complexity of the iteration is still bound by the actual number of attirbutes, the only difference now is that the contained switch will have ~40 case labels instead of some slightly smaller number.

source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

248

It's stored in the form in which the code expects to use it. Name used both as ConstString and as a c string, so I chose the first. The mangled name is only used as a c string, so I did not want to const-ify it needlessly (though the string will probably end up in the string pool anyway at some point.

[clayborg]

As long as the perf is similar I am good.

source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

die.GetDWARF()->GetObjectFile()->GetModule()->ReportError(
         type_name_cstr ? type_name_cstr : "", die.GetOffset());
     // We need to make the type look complete otherwise, we might crash in
     // Clang when adding children.
     if (ClangASTContext::StartTagDeclarationDefinition(type))
       ClangASTContext::CompleteTagDeclarationDefinition(type);
   }
 }
 
+namespace {
+/// Parsed form of all attributes that are relevant for type reconstruction.
+/// Some attributes are relevant for all kinds of types (declaration), while
+/// others are only meaningful to a specific type (is_virtual)
+struct ParsedTypeAttributes {
+  ParsedTypeAttributes(const DWARFDIE &die, CompileUnit &comp_unit);
+
+  AccessType accessibility = eAccessNone;
+  bool is_artificial = false;
+  bool is_complete_objc_class = false;
+  bool is_explicit = false;
+  bool is_forward_declaration = false;
+  bool is_inline = false;
+  bool is_scoped_enum = false;
+  bool is_vector = false;
+  bool is_virtual = false;
+  clang::StorageClass storage = clang::SC_None;
+  const char *mangled_name = nullptr;
+  ConstString name;
+  Declaration decl;
+  DWARFDIE object_pointer;
+  DWARFFormValue abstract_origin;
+  DWARFFormValue containing_type;
+  DWARFFormValue specification;
+  DWARFFormValue type;
+  LanguageType class_language = eLanguageTypeUnknown;
+  llvm::Optional<uint64_t> byte_size;
+  size_t calling_convention = llvm::dwarf::DW_CC_normal;
+  uint32_t bit_stride = 0;
+  uint32_t byte_stride = 0;
+  uint32_t encoding = 0;
+};
+} // namespace
+
+ParsedTypeAttributes::ParsedTypeAttributes(const DWARFDIE &die,
+                                           CompileUnit &comp_unit) {
+  DWARFAttributes attributes;
+  size_t num_attributes = die.GetAttributes(attributes);
+  for (size_t i = 0; i < num_attributes; ++i) {
+    dw_attr_t attr = attributes.AttributeAtIndex(i);
+    DWARFFormValue form_value;
+    if (!attributes.ExtractFormValueAtIndex(i, form_value))
+      continue;
+    switch (attr) {
+    case DW_AT_abstract_origin:
+      abstract_origin = form_value;
+      break;
+
+    case DW_AT_accessibility:
+      accessibility = DW_ACCESS_to_AccessType(form_value.Unsigned());
+      break;
+
+    case DW_AT_artificial:
+      is_artificial = form_value.Boolean();
+      break;
+
+    case DW_AT_bit_stride:
+      bit_stride = form_value.Unsigned();
+      break;
+
+    case DW_AT_byte_size:
+      byte_size = form_value.Unsigned();
+      break;
+
+    case DW_AT_byte_stride:
+      byte_stride = form_value.Unsigned();
+      break;
+
+    case DW_AT_calling_convention:
+      calling_convention = form_value.Unsigned();
+      break;
+
+    case DW_AT_containing_type:
+      containing_type = form_value;
+      break;
+
+    case DW_AT_decl_file:
+      decl.SetFile(comp_unit.GetSupportFiles().GetFileSpecAtIndex(
+          form_value.Unsigned()));
+      break;
+    case DW_AT_decl_line:
+      decl.SetLine(form_value.Unsigned());
+      break;
+    case DW_AT_decl_column:
+      decl.SetColumn(form_value.Unsigned());
+      break;
+
+    case DW_AT_declaration:
+      is_forward_declaration = form_value.Boolean();
+      break;
+
+    case DW_AT_encoding:
+      encoding = form_value.Unsigned();
+      break;
+
+    case DW_AT_enum_class:
+      is_scoped_enum = form_value.Boolean();
+      break;
+
+    case DW_AT_explicit:
+      is_explicit = form_value.Boolean();
+      break;
+
+    case DW_AT_external:
+      if (form_value.Unsigned())
+        storage = clang::SC_Extern;
+      break;
+
+    case DW_AT_inline:
+      is_inline = form_value.Boolean();
+      break;
+
+    case DW_AT_linkage_name:
+    case DW_AT_MIPS_linkage_name:
+      mangled_name = form_value.AsCString();
+      break;
+
+    case DW_AT_name:
+      name.SetCString(form_value.AsCString());
+      break;
+
+    case DW_AT_object_pointer:
+      object_pointer = form_value.Reference();
+      break;
+
+    case DW_AT_specification:
+      specification = form_value;
+      break;
+
+    case DW_AT_type:
+      type = form_value;
+      break;
+
+    case DW_AT_virtuality:
+      is_virtual = form_value.Boolean();
+      break;
+
+    case DW_AT_APPLE_objc_complete_type:
+      is_complete_objc_class = form_value.Signed();
+      break;
+
+    case DW_AT_APPLE_runtime_class:
+      class_language = (LanguageType)form_value.Signed();
+      break;
+
+    case DW_AT_GNU_vector:
+      is_vector = form_value.Boolean();
+      break;
+    }
+  }
+}
+
 TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
                                                const DWARFDIE &die, Log *log,
                                                bool *type_is_new_ptr) {
   if (type_is_new_ptr)
     *type_is_new_ptr = false;
 
-  AccessType accessibility = eAccessNone;
   if (!die)
     return nullptr;
   SymbolFileDWARF *dwarf = die.GetDWARF();
   if (log) {
     DWARFDIE context_die;
     clang::DeclContext *context =
         GetClangDeclContextContainingDIE(die, &context_die);
 
TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
   }
 
   TypeList *type_list = dwarf->GetTypeList();
   if (type_is_new_ptr)
     *type_is_new_ptr = true;
 
   const dw_tag_t tag = die.Tag();
 
-  bool is_forward_declaration = false;
-  DWARFAttributes attributes;
-  const char *type_name_cstr = NULL;
-  const char *mangled_name_cstr = NULL;
-  ConstString type_name_const_str;
   Type::ResolveState resolve_state = Type::eResolveStateUnresolved;
-  llvm::Optional<uint64_t> byte_size;
-  Declaration decl;
 
   Type::EncodingDataType encoding_data_type = Type::eEncodingIsUID;
   CompilerType clang_type;
-  DWARFFormValue form_value;
 
-  dw_attr_t attr;
+  ParsedTypeAttributes attrs(die, *sc.comp_unit);
   TypeSP type_sp;
   switch (tag) {
   case DW_TAG_typedef:
   case DW_TAG_base_type:
   case DW_TAG_pointer_type:
   case DW_TAG_reference_type:
   case DW_TAG_rvalue_reference_type:
   case DW_TAG_const_type:
   case DW_TAG_restrict_type:
   case DW_TAG_volatile_type:
   case DW_TAG_unspecified_type: {
-    const size_t num_attributes = die.GetAttributes(attributes);
-    uint32_t encoding = 0;
-    DWARFFormValue encoding_uid;
-
-    if (num_attributes > 0) {
-      uint32_t i;
-      for (i = 0; i < num_attributes; ++i) {
-        attr = attributes.AttributeAtIndex(i);
-        if (attributes.ExtractFormValueAtIndex(i, form_value)) {
-          switch (attr) {
-          case DW_AT_decl_file:
-            decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
-                form_value.Unsigned()));
-            break;
-          case DW_AT_decl_line:
-            decl.SetLine(form_value.Unsigned());
-            break;
-          case DW_AT_decl_column:
-            decl.SetColumn(form_value.Unsigned());
-            break;
-          case DW_AT_name:
-            type_name_cstr = form_value.AsCString();
-            if (type_name_cstr)
-              type_name_const_str.SetCString(type_name_cstr);
-            break;
-          case DW_AT_byte_size:
-            byte_size = form_value.Unsigned();
-            break;
-          case DW_AT_encoding:
-            encoding = form_value.Unsigned();
-            break;
-          case DW_AT_type:
-            encoding_uid = form_value;
-            break;
-          default:
-          case DW_AT_sibling:
-            break;
-          }
-        }
-      }
-    }
-
-    if (tag == DW_TAG_typedef && encoding_uid.IsValid()) {
+    if (tag == DW_TAG_typedef && attrs.type.IsValid()) {
       // Try to parse a typedef from the DWO file first as modules can
       // contain typedef'ed structures that have no names like:
       //
       //  typedef struct { int a; } Foo;
       //
       // In this case we will have a structure with no name and a typedef
       // named "Foo" that points to this unnamed structure. The name in the
       // typedef is the only identifier for the struct, so always try to
       // get typedefs from DWO files if possible.
       //
       // The type_sp returned will be empty if the typedef doesn't exist in
       // a DWO file, so it is cheap to call this function just to check.
       //
       // If we don't do this we end up creating a TypeSP that says this is
       // a typedef to type 0x123 (the DW_AT_type value would be 0x123 in
       // the DW_TAG_typedef), and this is the unnamed structure type. We
       // will have a hard time tracking down an unnammed structure type in
       // the module DWO file, so we make sure we don't get into this
       // situation by always resolving typedefs from the DWO file.
-      const DWARFDIE encoding_die = encoding_uid.Reference();
+      const DWARFDIE encoding_die = attrs.type.Reference();
 
       // First make sure that the die that this is typedef'ed to _is_ just
       // a declaration (DW_AT_declaration == 1), not a full definition
       // since template types can't be represented in modules since only
       // concrete instances of templates are ever emitted and modules won't
       // contain those
       if (encoding_die &&
           encoding_die.GetAttributeValueAsUnsigned(DW_AT_declaration, 0) == 1) {
         type_sp = ParseTypeFromDWO(die, log);
         if (type_sp)
           return type_sp;
       }
     }
 
     DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\") type => 0x%8.8lx\n",
                  die.GetID(), DW_TAG_value_to_name(tag), type_name_cstr,
                  encoding_uid.Reference());
 
     switch (tag) {
     default:
       break;
 
     case DW_TAG_unspecified_type:
-      if (strcmp(type_name_cstr, "nullptr_t") == 0 ||
-          strcmp(type_name_cstr, "decltype(nullptr)") == 0) {
+      if (attrs.name == "nullptr_t" || attrs.name == "decltype(nullptr)") {
         resolve_state = Type::eResolveStateFull;
         clang_type = m_ast.GetBasicType(eBasicTypeNullPtr);
         break;
       }
       // Fall through to base type below in case we can handle the type
       // there...
       LLVM_FALLTHROUGH;
 
     case DW_TAG_base_type:
       resolve_state = Type::eResolveStateFull;
       clang_type = m_ast.GetBuiltinTypeForDWARFEncodingAndBitSize(
-          type_name_cstr, encoding, byte_size.getValueOr(0) * 8);
+          attrs.name.GetCString(), attrs.encoding,
+          attrs.byte_size.getValueOr(0) * 8);
       break;
 
     case DW_TAG_pointer_type:
       encoding_data_type = Type::eEncodingIsPointerUID;
       break;
     case DW_TAG_reference_type:
       encoding_data_type = Type::eEncodingIsLValueReferenceUID;
       break;
if (!clang_type && (encoding_data_type == Type::eEncodingIsPointerUID ||
                 bool function_type_is_new_pointer;
                 TypeSP lldb_function_type_sp = ParseTypeFromDWARF(
                     sc, function_type, log, &function_type_is_new_pointer);
 
                 if (lldb_function_type_sp) {
                   clang_type = m_ast.CreateBlockPointerType(
                       lldb_function_type_sp->GetForwardCompilerType());
                   encoding_data_type = Type::eEncodingIsUID;
-                  encoding_uid.Clear();
+                  attrs.type.Clear();
                   resolve_state = Type::eResolveStateFull;
                 }
               }
 
               break;
             }
           }
         }
       }
 
       bool translation_unit_is_objc =
           (sc.comp_unit->GetLanguage() == eLanguageTypeObjC ||
            sc.comp_unit->GetLanguage() == eLanguageTypeObjC_plus_plus);
 
       if (translation_unit_is_objc) {
-        if (type_name_cstr != nullptr) {
+        if (attrs.name) {
           static ConstString g_objc_type_name_id("id");
           static ConstString g_objc_type_name_Class("Class");
           static ConstString g_objc_type_name_selector("SEL");
 
-          if (type_name_const_str == g_objc_type_name_id) {
+          if (attrs.name == g_objc_type_name_id) {
             if (log)
               dwarf->GetObjectFile()->GetModule()->LogMessage(
                   log,
                   "SymbolFileDWARF::ParseType (die = 0x%8.8x) %s '%s' "
                   "is Objective-C 'id' built-in type.",
                   die.GetOffset(), die.GetTagAsCString(), die.GetName());
             clang_type = m_ast.GetBasicType(eBasicTypeObjCID);
             encoding_data_type = Type::eEncodingIsUID;
-            encoding_uid.Clear();
+            attrs.type.Clear();
             resolve_state = Type::eResolveStateFull;
 
-          } else if (type_name_const_str == g_objc_type_name_Class) {
+          } else if (attrs.name == g_objc_type_name_Class) {
             if (log)
               dwarf->GetObjectFile()->GetModule()->LogMessage(
                   log,
                   "SymbolFileDWARF::ParseType (die = 0x%8.8x) %s '%s' "
                   "is Objective-C 'Class' built-in type.",
                   die.GetOffset(), die.GetTagAsCString(), die.GetName());
             clang_type = m_ast.GetBasicType(eBasicTypeObjCClass);
             encoding_data_type = Type::eEncodingIsUID;
-            encoding_uid.Clear();
+            attrs.type.Clear();
             resolve_state = Type::eResolveStateFull;
-          } else if (type_name_const_str == g_objc_type_name_selector) {
+          } else if (attrs.name == g_objc_type_name_selector) {
             if (log)
               dwarf->GetObjectFile()->GetModule()->LogMessage(
                   log,
                   "SymbolFileDWARF::ParseType (die = 0x%8.8x) %s '%s' "
                   "is Objective-C 'selector' built-in type.",
                   die.GetOffset(), die.GetTagAsCString(), die.GetName());
             clang_type = m_ast.GetBasicType(eBasicTypeObjCSel);
             encoding_data_type = Type::eEncodingIsUID;
-            encoding_uid.Clear();
+            attrs.type.Clear();
             resolve_state = Type::eResolveStateFull;
           }
         } else if (encoding_data_type == Type::eEncodingIsPointerUID &&
-                   encoding_uid.IsValid()) {
+                   attrs.type.IsValid()) {
           // Clang sometimes erroneously emits id as objc_object*.  In that
           // case we fix up the type to "id".
 
-          const DWARFDIE encoding_die = encoding_uid.Reference();
+          const DWARFDIE encoding_die = attrs.type.Reference();
 
           if (encoding_die && encoding_die.Tag() == DW_TAG_structure_type) {
             if (const char *struct_name = encoding_die.GetName()) {
               if (!strcmp(struct_name, "objc_object")) {
                 if (log)
                   dwarf->GetObjectFile()->GetModule()->LogMessage(
                       log,
                       "SymbolFileDWARF::ParseType (die = 0x%8.8x) %s "
                       "'%s' is 'objc_object*', which we overrode to "
                       "'id'.",
                       die.GetOffset(), die.GetTagAsCString(), die.GetName());
                 clang_type = m_ast.GetBasicType(eBasicTypeObjCID);
                 encoding_data_type = Type::eEncodingIsUID;
-                encoding_uid.Clear();
+                attrs.type.Clear();
                 resolve_state = Type::eResolveStateFull;
               }
             }
           }
         }
       }
     }
 
     type_sp = std::make_shared<Type>(
-        die.GetID(), dwarf, type_name_const_str, byte_size, nullptr,
-        dwarf->GetUID(DIERef(encoding_uid)), encoding_data_type, &decl,
+        die.GetID(), dwarf, attrs.name, attrs.byte_size, nullptr,
+        dwarf->GetUID(DIERef(attrs.type)), encoding_data_type, &attrs.decl,
         clang_type, resolve_state);
 
     dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
   } break;
 
   case DW_TAG_structure_type:
   case DW_TAG_union_type:
   case DW_TAG_class_type: {
-    LanguageType class_language = eLanguageTypeUnknown;
-    bool is_complete_objc_class = false;
-    size_t calling_convention = llvm::dwarf::CallingConvention::DW_CC_normal;
-
-    const size_t num_attributes = die.GetAttributes(attributes);
-    if (num_attributes > 0) {
-      uint32_t i;
-      for (i = 0; i < num_attributes; ++i) {
-        attr = attributes.AttributeAtIndex(i);
-        if (attributes.ExtractFormValueAtIndex(i, form_value)) {
-          switch (attr) {
-          case DW_AT_decl_file:
-            decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
-                form_value.Unsigned()));
-            break;
-
-          case DW_AT_decl_line:
-            decl.SetLine(form_value.Unsigned());
-            break;
-
-          case DW_AT_decl_column:
-            decl.SetColumn(form_value.Unsigned());
-            break;
-
-          case DW_AT_name:
-            type_name_cstr = form_value.AsCString();
-            type_name_const_str.SetCString(type_name_cstr);
-            break;
-
-          case DW_AT_byte_size:
-            byte_size = form_value.Unsigned();
-            break;
-
-          case DW_AT_accessibility:
-            accessibility = DW_ACCESS_to_AccessType(form_value.Unsigned());
-            break;
-
-          case DW_AT_declaration:
-            is_forward_declaration = form_value.Boolean();
-            break;
-
-          case DW_AT_APPLE_runtime_class:
-            class_language = (LanguageType)form_value.Signed();
-            break;
-
-          case DW_AT_APPLE_objc_complete_type:
-            is_complete_objc_class = form_value.Signed();
-            break;
-          case DW_AT_calling_convention:
-            calling_convention = form_value.Unsigned();
-            break;
-
-          case DW_AT_allocated:
-          case DW_AT_associated:
-          case DW_AT_data_location:
-          case DW_AT_description:
-          case DW_AT_start_scope:
-          case DW_AT_visibility:
-          default:
-          case DW_AT_sibling:
-            break;
-          }
-        }
-      }
-    }
-
     // UniqueDWARFASTType is large, so don't create a local variables on
     // the stack, put it on the heap. This function is often called
     // recursively and clang isn't good and sharing the stack space for
     // variables in different blocks.
     std::unique_ptr<UniqueDWARFASTType> unique_ast_entry_up(
         new UniqueDWARFASTType());
 
-    ConstString unique_typename(type_name_const_str);
-    Declaration unique_decl(decl);
+    ConstString unique_typename(attrs.name);
+    Declaration unique_decl(attrs.decl);
 
-    if (type_name_const_str) {
+    if (attrs.name) {
       LanguageType die_language = die.GetLanguage();
       if (Language::LanguageIsCPlusPlus(die_language)) {
         // For C++, we rely solely upon the one definition rule that says
         // only one thing can exist at a given decl context. We ignore the
         // file and line that things are declared on.
         std::string qualified_name;
         if (die.GetQualifiedName(qualified_name))
           unique_typename = ConstString(qualified_name);
         unique_decl.Clear();
       }
 
       if (dwarf->GetUniqueDWARFASTTypeMap().Find(
-              unique_typename, die, unique_decl, byte_size ? *byte_size : -1,
+              unique_typename, die, unique_decl, attrs.byte_size.getValueOr(-1),
               *unique_ast_entry_up)) {
         type_sp = unique_ast_entry_up->m_type_sp;
         if (type_sp) {
           dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
           return type_sp;
         }
       }
     }
case DW_TAG_class_type: {
     } else if (tag == DW_TAG_union_type) {
       tag_decl_kind = clang::TTK_Union;
       default_accessibility = eAccessPublic;
     } else if (tag == DW_TAG_class_type) {
       tag_decl_kind = clang::TTK_Class;
       default_accessibility = eAccessPrivate;
     }
 
-    if (byte_size && *byte_size == 0 && type_name_cstr && !die.HasChildren() &&
+    if (attrs.byte_size && *attrs.byte_size == 0 && attrs.name &&
+        !die.HasChildren() &&
         sc.comp_unit->GetLanguage() == eLanguageTypeObjC) {
       // Work around an issue with clang at the moment where forward
       // declarations for objective C classes are emitted as:
       //  DW_TAG_structure_type [2]
       //  DW_AT_name( "ForwardObjcClass" )
       //  DW_AT_byte_size( 0x00 )
       //  DW_AT_decl_file( "..." )
       //  DW_AT_decl_line( 1 )
       //
       // Note that there is no DW_AT_declaration and there are no children,
       // and the byte size is zero.
-      is_forward_declaration = true;
+      attrs.is_forward_declaration = true;
     }
 
-    if (class_language == eLanguageTypeObjC ||
-        class_language == eLanguageTypeObjC_plus_plus) {
-      if (!is_complete_objc_class &&
+    if (attrs.class_language == eLanguageTypeObjC ||
+        attrs.class_language == eLanguageTypeObjC_plus_plus) {
+      if (!attrs.is_complete_objc_class &&
           die.Supports_DW_AT_APPLE_objc_complete_type()) {
         // We have a valid eSymbolTypeObjCClass class symbol whose name
         // matches the current objective C class that we are trying to find
         // and this DIE isn't the complete definition (we checked
         // is_complete_objc_class above and know it is false), so the real
         // definition is in here somewhere
-        type_sp = dwarf->FindCompleteObjCDefinitionTypeForDIE(
-            die, type_name_const_str, true);
+        type_sp =
+            dwarf->FindCompleteObjCDefinitionTypeForDIE(die, attrs.name, true);
 
         if (!type_sp) {
           SymbolFileDWARFDebugMap *debug_map_symfile =
               dwarf->GetDebugMapSymfile();
           if (debug_map_symfile) {
             // We weren't able to find a full declaration in this DWARF,
             // see if we have a declaration anywhere else...
             type_sp = debug_map_symfile->FindCompleteObjCDefinitionTypeForDIE(
-                die, type_name_const_str, true);
+                die, attrs.name, true);
           }
         }
 
         if (type_sp) {
           if (log) {
             dwarf->GetObjectFile()->GetModule()->LogMessage(
                 log,
                 "SymbolFileDWARF(%p) - 0x%8.8x: %s type \"%s\" is an "
                 "incomplete objc type, complete type is 0x%8.8" PRIx64,
                 static_cast<void *>(this), die.GetOffset(),
-                DW_TAG_value_to_name(tag), type_name_cstr, type_sp->GetID());
+                DW_TAG_value_to_name(tag), attrs.name.GetCString(),
+                type_sp->GetID());
           }
 
           // We found a real definition for this type elsewhere so lets use
           // it and cache the fact that we found a complete type for this
           // die
           dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
           return type_sp;
         }
       }
     }
 
-    if (is_forward_declaration) {
+    if (attrs.is_forward_declaration) {
       // We have a forward declaration to a type and we need to try and
       // find a full declaration. We look in the current type index just in
       // case we have a forward declaration followed by an actual
       // declarations in the DWARF. If this fails, we need to look
       // elsewhere...
       if (log) {
         dwarf->GetObjectFile()->GetModule()->LogMessage(
             log,
             "SymbolFileDWARF(%p) - 0x%8.8x: %s type \"%s\" is a "
             "forward declaration, trying to find complete type",
             static_cast<void *>(this), die.GetOffset(),
-            DW_TAG_value_to_name(tag), type_name_cstr);
+            DW_TAG_value_to_name(tag), attrs.name.GetCString());
       }
 
       // See if the type comes from a DWO module and if so, track down that
       // type.
       type_sp = ParseTypeFromDWO(die, log);
       if (type_sp)
         return type_sp;
 
if (attrs.is_forward_declaration) {
 
       if (type_sp) {
         if (log) {
           dwarf->GetObjectFile()->GetModule()->LogMessage(
               log,
               "SymbolFileDWARF(%p) - 0x%8.8x: %s type \"%s\" is a "
               "forward declaration, complete type is 0x%8.8" PRIx64,
               static_cast<void *>(this), die.GetOffset(),
-              DW_TAG_value_to_name(tag), type_name_cstr, type_sp->GetID());
+              DW_TAG_value_to_name(tag), attrs.name.GetCString(),
+              type_sp->GetID());
         }
 
         // We found a real definition for this type elsewhere so lets use
         // it and cache the fact that we found a complete type for this die
         dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
         clang::DeclContext *defn_decl_ctx =
             GetCachedClangDeclContextForDIE(dwarf->GetDIE(type_sp->GetID()));
         if (defn_decl_ctx)
if (!clang_type) {
           GetClangDeclContextContainingDIE(die, nullptr);
 
       // If your decl context is a record that was imported from another
       // AST context (in the gmodules case), we need to make sure the type
       // backing the Decl is complete before adding children to it. This is
       // not an issue in the non-gmodules case because the debug info will
       // always contain a full definition of parent types in that case.
       CompleteExternalTagDeclType(GetClangASTImporter(), decl_ctx, die,
-                                  type_name_cstr);
+                                  attrs.name.GetCString());
 
-      if (accessibility == eAccessNone && decl_ctx) {
+      if (attrs.accessibility == eAccessNone && decl_ctx) {
         // Check the decl context that contains this class/struct/union. If
         // it is a class we must give it an accessibility.
         const clang::Decl::Kind containing_decl_kind = decl_ctx->getDeclKind();
         if (DeclKindIsCXXClass(containing_decl_kind))
-          accessibility = default_accessibility;
+          attrs.accessibility = default_accessibility;
       }
 
       ClangASTMetadata metadata;
       metadata.SetUserID(die.GetID());
       metadata.SetIsDynamicCXXType(dwarf->ClassOrStructIsVirtual(die));
 
-      if (type_name_cstr && strchr(type_name_cstr, '<')) {
+      if (attrs.name.GetStringRef().contains('<')) {
         ClangASTContext::TemplateParameterInfos template_param_infos;
         if (ParseTemplateParameterInfos(die, template_param_infos)) {
           clang::ClassTemplateDecl *class_template_decl =
-              m_ast.ParseClassTemplateDecl(decl_ctx, accessibility,
-                                           type_name_cstr, tag_decl_kind,
-                                           template_param_infos);
+              m_ast.ParseClassTemplateDecl(decl_ctx, attrs.accessibility,
+                                           attrs.name.GetCString(),
+                                           tag_decl_kind, template_param_infos);
           if (!class_template_decl) {
             if (log) {
               dwarf->GetObjectFile()->GetModule()->LogMessage(
                   log,
                   "SymbolFileDWARF(%p) - 0x%8.8x: %s type \"%s\" "
                   "clang::ClassTemplateDecl failed to return a decl.",
                   static_cast<void *>(this), die.GetOffset(),
-                  DW_TAG_value_to_name(tag), type_name_cstr);
+                  DW_TAG_value_to_name(tag), attrs.name.GetCString());
             }
             return TypeSP();
           }
 
           clang::ClassTemplateSpecializationDecl *class_specialization_decl =
               m_ast.CreateClassTemplateSpecializationDecl(
                   decl_ctx, class_template_decl, tag_decl_kind,
                   template_param_infos);
           clang_type = m_ast.CreateClassTemplateSpecializationType(
               class_specialization_decl);
           clang_type_was_created = true;
 
           m_ast.SetMetadata(class_template_decl, metadata);
           m_ast.SetMetadata(class_specialization_decl, metadata);
         }
       }
 
       if (!clang_type_was_created) {
         clang_type_was_created = true;
-        clang_type =
-            m_ast.CreateRecordType(decl_ctx, accessibility, type_name_cstr,
-                                   tag_decl_kind, class_language, &metadata);
+        clang_type = m_ast.CreateRecordType(
+            decl_ctx, attrs.accessibility, attrs.name.GetCString(),
+            tag_decl_kind, attrs.class_language, &metadata);
       }
     }
 
     // Store a forward declaration to this class type in case any
     // parameters in any class methods need it for the clang types for
     // function prototypes.
     LinkDeclContextToDIE(m_ast.GetDeclContextForType(clang_type), die);
-    type_sp = std::make_shared<Type>(die.GetID(), dwarf, type_name_const_str,
-                                     byte_size, nullptr, LLDB_INVALID_UID,
-                                     Type::eEncodingIsUID, &decl, clang_type,
+    type_sp = std::make_shared<Type>(die.GetID(), dwarf, attrs.name,
+                                     attrs.byte_size, nullptr, LLDB_INVALID_UID,
+                                     Type::eEncodingIsUID, &attrs.decl, clang_type,
                                      Type::eResolveStateForward);
 
-    type_sp->SetIsCompleteObjCClass(is_complete_objc_class);
+    type_sp->SetIsCompleteObjCClass(attrs.is_complete_objc_class);
 
     // Add our type to the unique type map so we don't end up creating many
     // copies of the same type over and over in the ASTContext for our
     // module
     unique_ast_entry_up->m_type_sp = type_sp;
     unique_ast_entry_up->m_die = die;
     unique_ast_entry_up->m_declaration = unique_decl;
-    unique_ast_entry_up->m_byte_size = byte_size.getValueOr(0);
+    unique_ast_entry_up->m_byte_size = attrs.byte_size.getValueOr(0);
     dwarf->GetUniqueDWARFASTTypeMap().Insert(unique_typename,
                                              *unique_ast_entry_up);
 
-    if (is_forward_declaration && die.HasChildren()) {
+    if (attrs.is_forward_declaration && die.HasChildren()) {
       // Check to see if the DIE actually has a definition, some version of
       // GCC will
       // emit DIEs with DW_AT_declaration set to true, but yet still have
       // subprogram, members, or inheritance, so we can't trust it
       DWARFDIE child_die = die.GetFirstChild();
       while (child_die) {
         switch (child_die.Tag()) {
         case DW_TAG_inheritance:
         case DW_TAG_subprogram:
         case DW_TAG_member:
         case DW_TAG_APPLE_property:
         case DW_TAG_class_type:
         case DW_TAG_structure_type:
         case DW_TAG_enumeration_type:
         case DW_TAG_typedef:
         case DW_TAG_union_type:
           child_die.Clear();
-          is_forward_declaration = false;
+          attrs.is_forward_declaration = false;
           break;
         default:
           child_die = child_die.GetSibling();
           break;
         }
       }
     }
 
-    if (!is_forward_declaration) {
+    if (!attrs.is_forward_declaration) {
       // Always start the definition for a class type so that if the class
       // has child classes or types that require the class to be created
       // for use as their decl contexts the class will be ready to accept
       // these child definitions.
       if (!die.HasChildren()) {
         // No children for this struct/union/class, lets finish it
         if (ClangASTContext::StartTagDeclarationDefinition(clang_type)) {
           ClangASTContext::CompleteTagDeclarationDefinition(clang_type);
         } else {
           dwarf->GetObjectFile()->GetModule()->ReportError(
               "DWARF DIE at 0x%8.8x named \"%s\" was not able to start its "
               "definition.\nPlease file a bug and attach the file at the "
               "start of this error message",
-              die.GetOffset(), type_name_cstr);
+              die.GetOffset(), attrs.name.GetCString());
         }
 
         if (tag == DW_TAG_structure_type) // this only applies in C
         {
           clang::RecordDecl *record_decl =
               ClangASTContext::GetAsRecordDecl(clang_type);
 
           if (record_decl) {
             GetClangASTImporter().InsertRecordDecl(
                 record_decl, ClangASTImporter::LayoutInfo());
           }
         }
       } else if (clang_type_was_created) {
         // Start the definition if the class is not objective C since the
         // underlying decls respond to isCompleteDefinition(). Objective
         // C decls don't respond to isCompleteDefinition() so we can't
         // start the declaration definition right away. For C++
         // class/union/structs we want to start the definition in case the
         // class is needed as the declaration context for a contained class
         // or type without the need to complete that type..
 
-        if (class_language != eLanguageTypeObjC &&
-            class_language != eLanguageTypeObjC_plus_plus)
+        if (attrs.class_language != eLanguageTypeObjC &&
+            attrs.class_language != eLanguageTypeObjC_plus_plus)
           ClangASTContext::StartTagDeclarationDefinition(clang_type);
 
         // Leave this as a forward declaration until we need to know the
         // details of the type. lldb_private::Type will automatically call
         // the SymbolFile virtual function
         // "SymbolFileDWARF::CompleteType(Type *)" When the definition
         // needs to be defined.
         assert(!dwarf->GetForwardDeclClangTypeToDie().count(
if (!attrs.is_forward_declaration) {
         m_ast.SetHasExternalStorage(clang_type.GetOpaqueQualType(), true);
       }
     }
 
     // If we made a clang type, set the trivial abi if applicable: We only
     // do this for pass by value - which implies the Trivial ABI. There
     // isn't a way to assert that something that would normally be pass by
     // value is pass by reference, so we ignore that attribute if set.
-    if (calling_convention == llvm::dwarf::DW_CC_pass_by_value) {
+    if (attrs.calling_convention == llvm::dwarf::DW_CC_pass_by_value) {
       clang::CXXRecordDecl *record_decl =
           m_ast.GetAsCXXRecordDecl(clang_type.GetOpaqueQualType());
       if (record_decl) {
         record_decl->setHasTrivialSpecialMemberForCall();
       }
     }
 
-    if (calling_convention == llvm::dwarf::DW_CC_pass_by_reference) {
+    if (attrs.calling_convention == llvm::dwarf::DW_CC_pass_by_reference) {
       clang::CXXRecordDecl *record_decl =
           m_ast.GetAsCXXRecordDecl(clang_type.GetOpaqueQualType());
       if (record_decl)
         record_decl->setArgPassingRestrictions(
             clang::RecordDecl::APK_CannotPassInRegs);
     }
 
   } break;
 
   case DW_TAG_enumeration_type: {
-    bool is_scoped = false;
-    DWARFFormValue encoding_form;
-
-    const size_t num_attributes = die.GetAttributes(attributes);
-    if (num_attributes > 0) {
-      uint32_t i;
-
-      for (i = 0; i < num_attributes; ++i) {
-        attr = attributes.AttributeAtIndex(i);
-        if (attributes.ExtractFormValueAtIndex(i, form_value)) {
-          switch (attr) {
-          case DW_AT_decl_file:
-            decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
-                form_value.Unsigned()));
-            break;
-          case DW_AT_decl_line:
-            decl.SetLine(form_value.Unsigned());
-            break;
-          case DW_AT_decl_column:
-            decl.SetColumn(form_value.Unsigned());
-            break;
-          case DW_AT_name:
-            type_name_cstr = form_value.AsCString();
-            type_name_const_str.SetCString(type_name_cstr);
-            break;
-          case DW_AT_type:
-            encoding_form = form_value;
-            break;
-          case DW_AT_byte_size:
-            byte_size = form_value.Unsigned();
-            break;
-          case DW_AT_accessibility:
-            break; // accessibility =
-                   // DW_ACCESS_to_AccessType(form_value.Unsigned()); break;
-          case DW_AT_declaration:
-            is_forward_declaration = form_value.Boolean();
-            break;
-          case DW_AT_enum_class:
-            is_scoped = form_value.Boolean();
-            break;
-          case DW_AT_allocated:
-          case DW_AT_associated:
-          case DW_AT_bit_stride:
-          case DW_AT_byte_stride:
-          case DW_AT_data_location:
-          case DW_AT_description:
-          case DW_AT_start_scope:
-          case DW_AT_visibility:
-          case DW_AT_specification:
-          case DW_AT_abstract_origin:
-          case DW_AT_sibling:
-            break;
-          }
-        }
-      }
-
-      if (is_forward_declaration) {
-        type_sp = ParseTypeFromDWO(die, log);
-        if (type_sp)
-          return type_sp;
+    if (attrs.is_forward_declaration) {
 
-        DWARFDeclContext die_decl_ctx;
-        die.GetDWARFDeclContext(die_decl_ctx);
 
-        type_sp = dwarf->FindDefinitionTypeForDWARFDeclContext(die_decl_ctx);
 
-        if (!type_sp) {
-          SymbolFileDWARFDebugMap *debug_map_symfile =
-              dwarf->GetDebugMapSymfile();
-          if (debug_map_symfile) {
-            // We weren't able to find a full declaration in this DWARF,
-            // see if we have a declaration anywhere else...
-            type_sp = debug_map_symfile->FindDefinitionTypeForDWARFDeclContext(
-                die_decl_ctx);
-          }
-        }
 
-        if (type_sp) {
-          if (log) {
-            dwarf->GetObjectFile()->GetModule()->LogMessage(
-                log,
-                "SymbolFileDWARF(%p) - 0x%8.8x: %s type \"%s\" is a "
-                "forward declaration, complete type is 0x%8.8" PRIx64,
-                static_cast<void *>(this), die.GetOffset(),
-                DW_TAG_value_to_name(tag), type_name_cstr, type_sp->GetID());
-          }
+              DW_TAG_value_to_name(tag), attrs.name.GetCString(),
+              type_sp->GetID());
 
-          // We found a real definition for this type elsewhere so lets use
-          // it and cache the fact that we found a complete type for this
-          // die
-          dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
-          clang::DeclContext *defn_decl_ctx =
-              GetCachedClangDeclContextForDIE(dwarf->GetDIE(type_sp->GetID()));
-          if (defn_decl_ctx)
-            LinkDeclContextToDIE(defn_decl_ctx, die);
-          return type_sp;
-        }
-      }
-      DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\")\n", die.GetID(),
-                   DW_TAG_value_to_name(tag), type_name_cstr);
 
-      CompilerType enumerator_clang_type;
-      clang_type.SetCompilerType(
-          &m_ast, dwarf->GetForwardDeclDieToClangType().lookup(die.GetDIE()));
-      if (!clang_type) {
-        if (encoding_form.IsValid()) {
-          Type *enumerator_type = dwarf->ResolveTypeUID(DIERef(encoding_form));
-          if (enumerator_type)
-            enumerator_clang_type = enumerator_type->GetFullCompilerType();
-        }
+      if (attrs.type.IsValid()) {
+        Type *enumerator_type = dwarf->ResolveTypeUID(DIERef(attrs.type));
 
-        if (!enumerator_clang_type) {
-          if (byte_size) {
-            enumerator_clang_type =
-                m_ast.GetBuiltinTypeForDWARFEncodingAndBitSize(
-                    NULL, DW_ATE_signed, *byte_size * 8);
-          } else {
-            enumerator_clang_type = m_ast.GetBasicType(eBasicTypeInt);
-          }
-        }
+        if (attrs.byte_size) {
+                  NULL, DW_ATE_signed, *attrs.byte_size * 8);
 
-        clang_type = m_ast.CreateEnumerationType(
-            type_name_cstr, GetClangDeclContextContainingDIE(die, nullptr),
-            decl, enumerator_clang_type, is_scoped);
-      } else {
-        enumerator_clang_type =
-            m_ast.GetEnumerationIntegerType(clang_type.GetOpaqueQualType());
-      }
+          attrs.name.GetCString(),
+          GetClangDeclContextContainingDIE(die, nullptr), attrs.decl,
+          enumerator_clang_type, attrs.is_scoped_enum);
 
-      LinkDeclContextToDIE(ClangASTContext::GetDeclContextForType(clang_type),
-                           die);
 
-      type_sp = std::make_shared<Type>(
-          die.GetID(), dwarf, type_name_const_str, byte_size, nullptr,
-          dwarf->GetUID(DIERef(encoding_form)), Type::eEncodingIsUID, &decl,
-          clang_type, Type::eResolveStateForward);
+        die.GetID(), dwarf, attrs.name, attrs.byte_size, nullptr,
+        dwarf->GetUID(DIERef(attrs.type)), Type::eEncodingIsUID, &attrs.decl,
 
-      if (ClangASTContext::StartTagDeclarationDefinition(clang_type)) {
-        if (die.HasChildren()) {
-          SymbolContext cu_sc(die.GetLLDBCompileUnit());
-          bool is_signed = false;
-          enumerator_clang_type.IsIntegerType(is_signed);
-          ParseChildEnumerators(cu_sc, clang_type, is_signed,
-                                type_sp->GetByteSize().getValueOr(0), die);
-        }
-        ClangASTContext::CompleteTagDeclarationDefinition(clang_type);
-      } else {
-        dwarf->GetObjectFile()->GetModule()->ReportError(
-            "DWARF DIE at 0x%8.8x named \"%s\" was not able to start its "
-            "definition.\nPlease file a bug and attach the file at the "
-            "start of this error message",
-            die.GetOffset(), type_name_cstr);
-      }
+          die.GetOffset(), attrs.name.GetCString());
     }
   } break;
 
   case DW_TAG_inlined_subroutine:
   case DW_TAG_subprogram:
   case DW_TAG_subroutine_type: {
-    DWARFFormValue type_die_form;
     bool is_variadic = false;
-    bool is_inline = false;
     bool is_static = false;
-    bool is_virtual = false;
-    bool is_explicit = false;
-    bool is_artificial = false;
     bool has_template_params = false;
-    DWARFFormValue specification_die_form;
-    DWARFFormValue abstract_origin_die_form;
-    DWARFDIE object_pointer_die;
 
     unsigned type_quals = 0;
-    clang::StorageClass storage =
-        clang::SC_None; //, Extern, Static, PrivateExtern
-
-    const size_t num_attributes = die.GetAttributes(attributes);
-    if (num_attributes > 0) {
-      uint32_t i;
-      for (i = 0; i < num_attributes; ++i) {
-        attr = attributes.AttributeAtIndex(i);
-        if (attributes.ExtractFormValueAtIndex(i, form_value)) {
-          switch (attr) {
-          case DW_AT_decl_file:
-            decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
-                form_value.Unsigned()));
-            break;
-          case DW_AT_decl_line:
-            decl.SetLine(form_value.Unsigned());
-            break;
-          case DW_AT_decl_column:
-            decl.SetColumn(form_value.Unsigned());
-            break;
-          case DW_AT_name:
-            type_name_cstr = form_value.AsCString();
-            type_name_const_str.SetCString(type_name_cstr);
-            break;
-
-          case DW_AT_linkage_name:
-          case DW_AT_MIPS_linkage_name:
-            mangled_name_cstr = form_value.AsCString();
-            break;
-          case DW_AT_type:
-            type_die_form = form_value;
-            break;
-          case DW_AT_accessibility:
-            accessibility = DW_ACCESS_to_AccessType(form_value.Unsigned());
-            break;
-          case DW_AT_declaration:
-            break; // is_forward_declaration = form_value.Boolean(); break;
-          case DW_AT_inline:
-            is_inline = form_value.Boolean();
-            break;
-          case DW_AT_virtuality:
-            is_virtual = form_value.Boolean();
-            break;
-          case DW_AT_explicit:
-            is_explicit = form_value.Boolean();
-            break;
-          case DW_AT_artificial:
-            is_artificial = form_value.Boolean();
-            break;
-
-          case DW_AT_external:
-            if (form_value.Unsigned()) {
-              if (storage == clang::SC_None)
-                storage = clang::SC_Extern;
-              else
-                storage = clang::SC_PrivateExtern;
-            }
-            break;
-
-          case DW_AT_specification:
-            specification_die_form = form_value;
-            break;
-
-          case DW_AT_abstract_origin:
-            abstract_origin_die_form = form_value;
-            break;
-
-          case DW_AT_object_pointer:
-            object_pointer_die = form_value.Reference();
-            break;
-
-          case DW_AT_allocated:
-          case DW_AT_associated:
-          case DW_AT_address_class:
-          case DW_AT_calling_convention:
-          case DW_AT_data_location:
-          case DW_AT_elemental:
-          case DW_AT_entry_pc:
-          case DW_AT_frame_base:
-          case DW_AT_high_pc:
-          case DW_AT_low_pc:
-          case DW_AT_prototyped:
-          case DW_AT_pure:
-          case DW_AT_ranges:
-          case DW_AT_recursive:
-          case DW_AT_return_addr:
-          case DW_AT_segment:
-          case DW_AT_start_scope:
-          case DW_AT_static_link:
-          case DW_AT_trampoline:
-          case DW_AT_visibility:
-          case DW_AT_vtable_elem_location:
-          case DW_AT_description:
-          case DW_AT_sibling:
-            break;
-          }
-        }
-      }
-    }
 
     std::string object_pointer_name;
-    if (object_pointer_die) {
-      const char *object_pointer_name_cstr = object_pointer_die.GetName();
+    if (attrs.object_pointer) {
+      const char *object_pointer_name_cstr = attrs.object_pointer.GetName();
       if (object_pointer_name_cstr)
         object_pointer_name = object_pointer_name_cstr;
     }
 
     DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\")\n", die.GetID(),
                  DW_TAG_value_to_name(tag), type_name_cstr);
 
     CompilerType return_clang_type;
     Type *func_type = NULL;
 
-    if (type_die_form.IsValid())
-      func_type = dwarf->ResolveTypeUID(DIERef(type_die_form));
+    if (attrs.type.IsValid())
+      func_type = dwarf->ResolveTypeUID(DIERef(attrs.type));
 
     if (func_type)
       return_clang_type = func_type->GetForwardCompilerType();
     else
       return_clang_type = m_ast.GetBasicType(eBasicTypeVoid);
 
     std::vector<CompilerType> function_param_types;
     std::vector<clang::ParmVarDecl *> function_param_decls;
case DW_TAG_subroutine_type: {
     }
 
     // clang_type will get the function prototype clang type after this
     // call
     clang_type = m_ast.CreateFunctionType(
         return_clang_type, function_param_types.data(),
         function_param_types.size(), is_variadic, type_quals);
 
-    if (type_name_cstr) {
+    if (attrs.name) {
       bool type_handled = false;
       if (tag == DW_TAG_subprogram || tag == DW_TAG_inlined_subroutine) {
-        ObjCLanguage::MethodName objc_method(type_name_cstr, true);
+        ObjCLanguage::MethodName objc_method(attrs.name.GetStringRef(), true);
         if (objc_method.IsValid(true)) {
           CompilerType class_opaque_type;
           ConstString class_name(objc_method.GetClassName());
           if (class_name) {
             TypeSP complete_objc_class_type_sp(
                 dwarf->FindCompleteObjCDefinitionTypeForDIE(DWARFDIE(),
                                                             class_name, false));
 
             if (complete_objc_class_type_sp) {
               CompilerType type_clang_forward_type =
                   complete_objc_class_type_sp->GetForwardCompilerType();
               if (ClangASTContext::IsObjCObjectOrInterfaceType(
                       type_clang_forward_type))
                 class_opaque_type = type_clang_forward_type;
             }
           }
 
           if (class_opaque_type) {
             // If accessibility isn't set to anything valid, assume public
             // for now...
-            if (accessibility == eAccessNone)
-              accessibility = eAccessPublic;
+            if (attrs.accessibility == eAccessNone)
+              attrs.accessibility = eAccessPublic;
 
             clang::ObjCMethodDecl *objc_method_decl =
                 m_ast.AddMethodToObjCObjectType(
-                    class_opaque_type, type_name_cstr, clang_type,
-                    accessibility, is_artificial, is_variadic);
+                    class_opaque_type, attrs.name.GetCString(), clang_type,
+                    attrs.accessibility, attrs.is_artificial, is_variadic);
             type_handled = objc_method_decl != NULL;
             if (type_handled) {
               LinkDeclContextToDIE(
                   ClangASTContext::GetAsDeclContext(objc_method_decl), die);
               m_ast.SetMetadataAsUserID(objc_method_decl, die.GetID());
             } else {
               dwarf->GetObjectFile()->GetModule()->ReportError(
                   "{0x%8.8x}: invalid Objective-C method 0x%4.4x (%s), "
if (attrs.name) {
                 type_ptr = dwarf->GetDIEToType()[die.GetDIE()];
                 if (type_ptr && type_ptr != DIE_IS_BEING_PARSED) {
                   type_sp = type_ptr->shared_from_this();
                   break;
                 }
               }
             }
 
-            if (specification_die_form.IsValid()) {
+            if (attrs.specification.IsValid()) {
               // We have a specification which we are going to base our
               // function prototype off of, so we need this type to be
               // completed so that the m_die_to_decl_ctx for the method in
               // the specification has a valid clang decl context.
               class_type->GetForwardCompilerType();
               // If we have a specification, then the function type should
               // have been made with the specification and not with this
               // die.
               DWARFDIE spec_die =
-                  dwarf->DebugInfo()->GetDIE(DIERef(specification_die_form));
+                  dwarf->DebugInfo()->GetDIE(DIERef(attrs.specification));
               clang::DeclContext *spec_clang_decl_ctx =
                   GetClangDeclContextForDIE(spec_die);
               if (spec_clang_decl_ctx) {
                 LinkDeclContextToDIE(spec_clang_decl_ctx, die);
               } else {
                 dwarf->GetObjectFile()->GetModule()->ReportWarning(
                     "0x%8.8" PRIx64 ": DW_AT_specification(0x%8.8x"
                     ") has no decl\n",
-                    die.GetID(),
-                    specification_die_form.Reference().GetOffset());
+                    die.GetID(), attrs.specification.Reference().GetOffset());
               }
               type_handled = true;
-            } else if (abstract_origin_die_form.IsValid()) {
+            } else if (attrs.abstract_origin.IsValid()) {
               // We have a specification which we are going to base our
               // function prototype off of, so we need this type to be
               // completed so that the m_die_to_decl_ctx for the method in
               // the abstract origin has a valid clang decl context.
               class_type->GetForwardCompilerType();
 
               DWARFDIE abs_die =
-                  dwarf->DebugInfo()->GetDIE(DIERef(abstract_origin_die_form));
+                  dwarf->DebugInfo()->GetDIE(DIERef(attrs.abstract_origin));
               clang::DeclContext *abs_clang_decl_ctx =
                   GetClangDeclContextForDIE(abs_die);
               if (abs_clang_decl_ctx) {
                 LinkDeclContextToDIE(abs_clang_decl_ctx, die);
               } else {
                 dwarf->GetObjectFile()->GetModule()->ReportWarning(
                     "0x%8.8" PRIx64 ": DW_AT_abstract_origin(0x%8.8x"
                     ") has no decl\n",
-                    die.GetID(),
-                    abstract_origin_die_form.Reference().GetOffset());
+                    die.GetID(), attrs.abstract_origin.Reference().GetOffset());
               }
               type_handled = true;
             } else {
               CompilerType class_opaque_type =
                   class_type->GetForwardCompilerType();
               if (ClangASTContext::IsCXXClassType(class_opaque_type)) {
                 if (class_opaque_type.IsBeingDefined() || alternate_defn) {
                   if (!is_static && !die.HasChildren()) {
if (attrs.name) {
                           m_ast.GetAsCXXRecordDecl(
                               class_opaque_type.GetOpaqueQualType());
                       if (record_decl) {
                         for (auto method_iter = record_decl->method_begin();
                              method_iter != record_decl->method_end();
                              method_iter++) {
                           clang::CXXMethodDecl *method_decl = *method_iter;
                           if (method_decl->getNameInfo().getAsString() ==
-                              std::string(type_name_cstr)) {
+                              attrs.name.GetStringRef()) {
                             if (method_decl->getType() ==
                                 ClangUtil::GetQualType(clang_type)) {
                               add_method = false;
                               LinkDeclContextToDIE(
                                   ClangASTContext::GetAsDeclContext(
                                       method_decl),
                                   die);
                               type_handled = true;
 
                               break;
                             }
                           }
                         }
                       }
                     }
 
                     if (add_method) {
                       llvm::PrettyStackTraceFormat stack_trace(
                           "SymbolFileDWARF::ParseType() is adding a method "
                           "%s to class %s in DIE 0x%8.8" PRIx64 " from %s",
-                          type_name_cstr, class_type->GetName().GetCString(),
-                          die.GetID(),
+                          attrs.name.GetCString(),
+                          class_type->GetName().GetCString(), die.GetID(),
                           dwarf->GetObjectFile()
                               ->GetFileSpec()
                               .GetPath()
                               .c_str());
 
                       const bool is_attr_used = false;
                       // Neither GCC 4.2 nor clang++ currently set a valid
                       // accessibility in the DWARF for C++ methods...
                       // Default to public for now...
-                      if (accessibility == eAccessNone)
-                        accessibility = eAccessPublic;
+                      if (attrs.accessibility == eAccessNone)
+                        attrs.accessibility = eAccessPublic;
 
                       clang::CXXMethodDecl *cxx_method_decl =
                           m_ast.AddMethodToCXXRecordType(
                               class_opaque_type.GetOpaqueQualType(),
-                              type_name_cstr, mangled_name_cstr, clang_type,
-                              accessibility, is_virtual, is_static, is_inline,
-                              is_explicit, is_attr_used, is_artificial);
+                              attrs.name.GetCString(), attrs.mangled_name,
+                              clang_type, attrs.accessibility, attrs.is_virtual,
+                              is_static, attrs.is_inline, attrs.is_explicit,
+                              is_attr_used, attrs.is_artificial);
 
                       type_handled = cxx_method_decl != NULL;
 
                       if (type_handled) {
                         LinkDeclContextToDIE(
                             ClangASTContext::GetAsDeclContext(cxx_method_decl),
                             die);
 
if (attrs.name) {
           }
         }
       }
 
       if (!type_handled) {
         clang::FunctionDecl *function_decl = nullptr;
         clang::FunctionDecl *template_function_decl = nullptr;
 
-        if (abstract_origin_die_form.IsValid()) {
-          DWARFDIE abs_die = abstract_origin_die_form.Reference();
+        if (attrs.abstract_origin.IsValid()) {
+          DWARFDIE abs_die = attrs.abstract_origin.Reference();
 
           SymbolContext sc;
 
           if (dwarf->ResolveType(abs_die)) {
             function_decl = llvm::dyn_cast_or_null<clang::FunctionDecl>(
                 GetCachedClangDeclContextForDIE(abs_die));
 
             if (function_decl) {
               LinkDeclContextToDIE(function_decl, die);
             }
           }
         }
 
         if (!function_decl) {
           // We just have a function that isn't part of a class
           function_decl = m_ast.CreateFunctionDeclaration(
               ignore_containing_context ? m_ast.GetTranslationUnitDecl()
                                         : containing_decl_ctx,
-              type_name_cstr, clang_type, storage, is_inline);
+              attrs.name.GetCString(), clang_type, attrs.storage,
+              attrs.is_inline);
 
           if (has_template_params) {
             ClangASTContext::TemplateParameterInfos template_param_infos;
             ParseTemplateParameterInfos(die, template_param_infos);
             template_function_decl = m_ast.CreateFunctionDeclaration(
                 ignore_containing_context ? m_ast.GetTranslationUnitDecl()
                                           : containing_decl_ctx,
-                type_name_cstr, clang_type, storage, is_inline);
+                attrs.name.GetCString(), clang_type, attrs.storage,
+                attrs.is_inline);
             clang::FunctionTemplateDecl *func_template_decl =
                 m_ast.CreateFunctionTemplateDecl(
-                    containing_decl_ctx, template_function_decl, type_name_cstr,
-                    template_param_infos);
+                    containing_decl_ctx, template_function_decl,
+                    attrs.name.GetCString(), template_param_infos);
             m_ast.CreateFunctionTemplateSpecializationInfo(
                 function_decl, func_template_decl, template_param_infos);
           }
 
           lldbassert(function_decl);
 
           if (function_decl) {
             LinkDeclContextToDIE(function_decl, die);
if (attrs.name) {
                             object_pointer_name.c_str(),
                             static_cast<void *>(function_decl));
             }
             m_ast.SetMetadata(function_decl, metadata);
           }
         }
       }
     }
-    type_sp = std::make_shared<Type>(die.GetID(), dwarf, type_name_const_str,
-                                     llvm::None, nullptr, LLDB_INVALID_UID,
-                                     Type::eEncodingIsUID, &decl, clang_type,
-                                     Type::eResolveStateFull);
+    type_sp = std::make_shared<Type>(
+        die.GetID(), dwarf, attrs.name, llvm::None, nullptr, LLDB_INVALID_UID,
+        Type::eEncodingIsUID, &attrs.decl, clang_type, Type::eResolveStateFull);
     assert(type_sp.get());
   } break;
 
   case DW_TAG_array_type: {
-    DWARFFormValue type_die_form;
-    uint32_t byte_stride = 0;
-    uint32_t bit_stride = 0;
-    bool is_vector = false;
-    const size_t num_attributes = die.GetAttributes(attributes);
-
-    if (num_attributes > 0) {
-      uint32_t i;
-      for (i = 0; i < num_attributes; ++i) {
-        attr = attributes.AttributeAtIndex(i);
-        if (attributes.ExtractFormValueAtIndex(i, form_value)) {
-          switch (attr) {
-          case DW_AT_decl_file:
-            decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
-                form_value.Unsigned()));
-            break;
-          case DW_AT_decl_line:
-            decl.SetLine(form_value.Unsigned());
-            break;
-          case DW_AT_decl_column:
-            decl.SetColumn(form_value.Unsigned());
-            break;
-          case DW_AT_name:
-            type_name_cstr = form_value.AsCString();
-            type_name_const_str.SetCString(type_name_cstr);
-            break;
-
-          case DW_AT_type:
-            type_die_form = form_value;
-            break;
-          case DW_AT_byte_size:
-            break; // byte_size = form_value.Unsigned(); break;
-          case DW_AT_byte_stride:
-            byte_stride = form_value.Unsigned();
-            break;
-          case DW_AT_bit_stride:
-            bit_stride = form_value.Unsigned();
-            break;
-          case DW_AT_GNU_vector:
-            is_vector = form_value.Boolean();
-            break;
-          case DW_AT_accessibility:
-            break; // accessibility =
-                   // DW_ACCESS_to_AccessType(form_value.Unsigned()); break;
-          case DW_AT_declaration:
-            break; // is_forward_declaration = form_value.Boolean(); break;
-          case DW_AT_allocated:
-          case DW_AT_associated:
-          case DW_AT_data_location:
-          case DW_AT_description:
-          case DW_AT_ordering:
-          case DW_AT_start_scope:
-          case DW_AT_visibility:
-          case DW_AT_specification:
-          case DW_AT_abstract_origin:
-          case DW_AT_sibling:
-            break;
-          }
-        }
-      }
-
-      DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\")\n", die.GetID(),
-                   DW_TAG_value_to_name(tag), type_name_cstr);
 
-      DIERef type_die_ref(type_die_form);
-      Type *element_type = dwarf->ResolveTypeUID(type_die_ref);
+    DIERef type_die_ref(attrs.type);
 
-      if (element_type) {
-        auto array_info = ParseChildArrayInfo(die);
-        if (array_info) {
-          byte_stride = array_info->byte_stride;
-          bit_stride = array_info->bit_stride;
-        }
-        if (byte_stride == 0 && bit_stride == 0)
-          byte_stride = element_type->GetByteSize().getValueOr(0);
-        CompilerType array_element_type =
-            element_type->GetForwardCompilerType();
+        attrs.byte_stride = array_info->byte_stride;
+        attrs.bit_stride = array_info->bit_stride;
+      if (attrs.byte_stride == 0 && attrs.bit_stride == 0)
+        attrs.byte_stride = element_type->GetByteSize().getValueOr(0);
+      CompilerType array_element_type = element_type->GetForwardCompilerType();
 
-        if (ClangASTContext::IsCXXClassType(array_element_type) &&
-            !array_element_type.GetCompleteType()) {
-          ModuleSP module_sp = die.GetModule();
-          if (module_sp) {
-            if (die.GetCU()->GetProducer() == eProducerClang)
-              module_sp->ReportError(
-                  "DWARF DW_TAG_array_type DIE at 0x%8.8x has a "
-                  "class/union/struct element type DIE 0x%8.8x that is a "
-                  "forward declaration, not a complete definition.\nTry "
-                  "compiling the source file with -fstandalone-debug or "
-                  "disable -gmodules",
-                  die.GetOffset(), type_die_ref.die_offset);
-            else
-              module_sp->ReportError(
-                  "DWARF DW_TAG_array_type DIE at 0x%8.8x has a "
-                  "class/union/struct element type DIE 0x%8.8x that is a "
-                  "forward declaration, not a complete definition.\nPlease "
-                  "file a bug against the compiler and include the "
-                  "preprocessed output for %s",
-                  die.GetOffset(), type_die_ref.die_offset,
-                  die.GetLLDBCompileUnit()
-                      ? die.GetLLDBCompileUnit()->GetPath().c_str()
-                      : "the source file");
-          }
 
-          // We have no choice other than to pretend that the element class
-          // type is complete. If we don't do this, clang will crash when
-          // trying to layout the class. Since we provide layout
-          // assistance, all ivars in this class and other classes will be
-          // fine, this is the best we can do short of crashing.
-          if (ClangASTContext::StartTagDeclarationDefinition(
-                  array_element_type)) {
-            ClangASTContext::CompleteTagDeclarationDefinition(
-                array_element_type);
-          } else {
-            module_sp->ReportError("DWARF DIE at 0x%8.8x was not able to "
-                                   "start its definition.\nPlease file a "
-                                   "bug and attach the file at the start "
-                                   "of this error message",
-                                   type_die_ref.die_offset);
-          }
-        }
+          ClangASTContext::CompleteTagDeclarationDefinition(array_element_type);
 
-        uint64_t array_element_bit_stride = byte_stride * 8 + bit_stride;
-        if (array_info && array_info->element_orders.size() > 0) {
-          uint64_t num_elements = 0;
-          auto end = array_info->element_orders.rend();
-          for (auto pos = array_info->element_orders.rbegin(); pos != end;
-               ++pos) {
-            num_elements = *pos;
-            clang_type = m_ast.CreateArrayType(array_element_type, num_elements,
-                                               is_vector);
-            array_element_type = clang_type;
-            array_element_bit_stride =
-                num_elements ? array_element_bit_stride * num_elements
-                             : array_element_bit_stride;
-          }
-        } else {
-          clang_type = m_ast.CreateArrayType(array_element_type, 0, is_vector);
-        }
-        ConstString empty_name;
-        type_sp = std::make_shared<Type>(
-            die.GetID(), dwarf, empty_name, array_element_bit_stride / 8,
-            nullptr, dwarf->GetUID(DIERef(type_die_form)), Type::eEncodingIsUID,
-            &decl, clang_type, Type::eResolveStateFull);
-        type_sp->SetEncodingType(element_type);
-        m_ast.SetMetadataAsUserID(clang_type.GetOpaqueQualType(), die.GetID());
-      }
-    }
+      uint64_t array_element_bit_stride =
+          attrs.byte_stride * 8 + attrs.bit_stride;
+                                             attrs.is_vector);
+        clang_type = m_ast.CreateArrayType(array_element_type, 0, attrs.is_vector);
+          die.GetID(), dwarf, empty_name, array_element_bit_stride / 8, nullptr,
+          dwarf->GetUID(type_die_ref), Type::eEncodingIsUID, &attrs.decl,
+          clang_type, Type::eResolveStateFull);
   } break;
 
   case DW_TAG_ptr_to_member_type: {
-    DWARFFormValue type_die_form;
-    DWARFFormValue containing_type_die_form;
-
-    const size_t num_attributes = die.GetAttributes(attributes);
-
-    if (num_attributes > 0) {
-      uint32_t i;
-      for (i = 0; i < num_attributes; ++i) {
-        attr = attributes.AttributeAtIndex(i);
-        if (attributes.ExtractFormValueAtIndex(i, form_value)) {
-          switch (attr) {
-          case DW_AT_type:
-            type_die_form = form_value;
-            break;
-          case DW_AT_containing_type:
-            containing_type_die_form = form_value;
-            break;
-          }
-        }
-      }
-
-      Type *pointee_type = dwarf->ResolveTypeUID(DIERef(type_die_form));
-      Type *class_type =
-          dwarf->ResolveTypeUID(DIERef(containing_type_die_form));
+    Type *pointee_type = dwarf->ResolveTypeUID(DIERef(attrs.type));
+    Type *class_type = dwarf->ResolveTypeUID(DIERef(attrs.containing_type));
 
-      CompilerType pointee_clang_type = pointee_type->GetForwardCompilerType();
-      CompilerType class_clang_type = class_type->GetLayoutCompilerType();
 
-      clang_type = ClangASTContext::CreateMemberPointerType(class_clang_type,
-                                                            pointee_clang_type);
 
-      if (llvm::Optional<uint64_t> clang_type_size =
-              clang_type.GetByteSize(nullptr)) {
-        byte_size = *clang_type_size;
-        type_sp = std::make_shared<Type>(
-            die.GetID(), dwarf, type_name_const_str, byte_size, nullptr,
-            LLDB_INVALID_UID, Type::eEncodingIsUID, nullptr, clang_type,
-            Type::eResolveStateForward);
-      }
-    }
+          die.GetID(), dwarf, attrs.name, *clang_type_size, nullptr,
 
     break;
   }
   default:
     dwarf->GetObjectFile()->GetModule()->ReportError(
         "{0x%8.8x}: unhandled type tag 0x%4.4x (%s), please file a bug and "
         "attach the file at the start of this error message",
         die.GetOffset(), tag, DW_TAG_value_to_name(tag));