[lldb][ClangASTImporter] Assert that we never overwrite a record layout

Author: Michael137

lldb/source/Plugins/ExpressionParser/Clang/ClangASTImporter.cpp

@@ -767,7 +767,6 @@ bool ClangASTImporter::LayoutRecordType(
     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);
     return true;
   }
 
@@ -789,9 +788,15 @@ bool ClangASTImporter::LayoutRecordType(
 
 void ClangASTImporter::SetRecordLayout(clang::RecordDecl *decl,
                                         const LayoutInfo &layout) {
+  assert(!HasRecordLayout(decl) && "Trying to overwrite layout?");
   m_record_decl_to_layout_map.insert(std::make_pair(decl, layout));
 }
 
+bool ClangASTImporter::HasRecordLayout(const RecordDecl *decl) const {
+  decl = llvm::cast<RecordDecl>(decl->getFirstDecl());
+  return m_record_decl_to_layout_map.count(decl) > 0;
+}
+
 bool ClangASTImporter::CompleteTagDecl(clang::TagDecl *decl) {
   DeclOrigin decl_origin = GetDeclOrigin(decl);
 

lldb/source/Plugins/ExpressionParser/Clang/ClangASTImporter.h

@@ -119,6 +119,8 @@ class ClangASTImporter {
   /// \param layout The layout for the record.
   void SetRecordLayout(clang::RecordDecl *decl, const LayoutInfo &layout);
 
+  bool HasRecordLayout(const clang::RecordDecl *decl) const;
+
   bool LayoutRecordType(
       const clang::RecordDecl *record_decl, uint64_t &bit_size,
       uint64_t &alignment,

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

@@ -2276,8 +2276,9 @@ bool DWARFASTParserClang::CompleteRecordType(const DWARFDIE &die,
   TypeSystemClang::BuildIndirectFields(clang_type);
   TypeSystemClang::CompleteTagDeclarationDefinition(clang_type);
 
-  if (!layout_info.field_offsets.empty() || !layout_info.base_offsets.empty() ||
-      !layout_info.vbase_offsets.empty()) {
+  clang::CXXRecordDecl *record_decl =
+      m_ast.GetAsCXXRecordDecl(clang_type.GetOpaqueQualType());
+  if (record_decl && !GetClangASTImporter().HasRecordLayout(record_decl)) {
     if (type)
       layout_info.bit_size = type->GetByteSize(nullptr).value_or(0) * 8;
     if (layout_info.bit_size == 0)
@@ -2287,10 +2288,7 @@ bool DWARFASTParserClang::CompleteRecordType(const DWARFDIE &die,
       layout_info.alignment =
           die.GetAttributeValueAsUnsigned(llvm::dwarf::DW_AT_alignment, 0) * 8;
 
-    clang::CXXRecordDecl *record_decl =
-        m_ast.GetAsCXXRecordDecl(clang_type.GetOpaqueQualType());
-    if (record_decl)
-      GetClangASTImporter().SetRecordLayout(record_decl, layout_info);
+    GetClangASTImporter().SetRecordLayout(record_decl, layout_info);
   }
   // Now parse all contained types inside of the class. We make forward
   // declarations to all classes, but we need the CXXRecordDecl to have decls