[Lldb-commits] [lldb] [lldb][DWARF] Delay struct/class/union definition DIE searching when parsing declaration DIEs. (PR #90663)

[Pavel Labath via lldb-commits]

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@@ -1667,13 +1791,40 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
     }
 
     if (dwarf->GetUniqueDWARFASTTypeMap().Find(
-            unique_typename, die, unique_decl, attrs.byte_size.value_or(-1),
-            *unique_ast_entry_up)) {
+            unique_typename, die, unique_decl, byte_size,
+            attrs.is_forward_declaration, *unique_ast_entry_up)) {
       type_sp = unique_ast_entry_up->m_type_sp;
       if (type_sp) {
         dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
         LinkDeclContextToDIE(
             GetCachedClangDeclContextForDIE(unique_ast_entry_up->m_die), die);
+        if (!attrs.is_forward_declaration) {
+          // If the DIE being parsed in this function is a definition and the
+          // entry in the map is a declaration, then we need to update the entry
+          // to point to the definition DIE.
+          if (unique_ast_entry_up->m_is_forward_declaration) {
+            unique_ast_entry_up->m_die = die;
+            unique_ast_entry_up->m_byte_size = byte_size;
+            unique_ast_entry_up->m_declaration = unique_decl;
+            unique_ast_entry_up->m_is_forward_declaration = false;
+            // Need to update Type ID to refer to the definition DIE. because
+            // it's used in ParseSubroutine to determine if we need to copy cxx
+            // method types from a declaration DIE to this definition DIE.
+            type_sp->SetID(die.GetID());
+            clang_type = type_sp->GetForwardCompilerType();
+            if (attrs.class_language != eLanguageTypeObjC &&
+                attrs.class_language != eLanguageTypeObjC_plus_plus)
+              TypeSystemClang::StartTagDeclarationDefinition(clang_type);
+
+            CompilerType compiler_type_no_qualifiers =
+                ClangUtil::RemoveFastQualifiers(clang_type);
+            auto result = dwarf->GetForwardDeclCompilerTypeToDIE().try_emplace(
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labath wrote:

The if below is just implementing overwrite semantics, but maps already have APIs for that. How about `dwarf->GetForwardDeclCompilerTypeToDIE()[compiler_type_no_qualifiers.GetOpaqueQualType()] = *die.GetDIERef()` ?

https://github.com/llvm/llvm-project/pull/90663