1 files changed, 24 insertions, 24 deletions

diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp
index 6fe85a1298fc..0f34c48c7e82 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp
@@ -71,20 +71,22 @@ ClangASTSource::~ClangASTSource() {
 
   if (!m_target)
     return;
-  // We are in the process of destruction, don't create clang ast context on
-  // demand by passing false to
-  // Target::GetScratchTypeSystemClang(create_on_demand).
-  TypeSystemClang *scratch_clang_ast_context =
-      TypeSystemClang::GetScratch(*m_target, false);
 
-  if (!scratch_clang_ast_context)
-    return;
+  // Unregister the current ASTContext as a source for all scratch
+  // ASTContexts in the ClangASTImporter. Without this the scratch AST might
+  // query the deleted ASTContext for additional type information.
+  // We unregister from *all* scratch ASTContexts in case a type got exported
+  // to a scratch AST that isn't the best fitting scratch ASTContext.
+  TypeSystemClang *scratch_ast = ScratchTypeSystemClang::GetForTarget(
+      *m_target, ScratchTypeSystemClang::DefaultAST, false);
 
-  clang::ASTContext &scratch_ast_context =
-      scratch_clang_ast_context->getASTContext();
+  if (!scratch_ast)
+    return;
 
-  if (m_ast_context != &scratch_ast_context && m_ast_importer_sp)
-    m_ast_importer_sp->ForgetSource(&scratch_ast_context, m_ast_context);
+  ScratchTypeSystemClang *default_scratch_ast =
+      llvm::cast<ScratchTypeSystemClang>(scratch_ast);
+  // Unregister from the default scratch AST (and all sub-ASTs).
+  default_scratch_ast->ForgetSource(m_ast_context, *m_ast_importer_sp);
 }
 
 void ClangASTSource::StartTranslationUnit(ASTConsumer *Consumer) {
@@ -482,6 +484,15 @@ void ClangASTSource::FindExternalLexicalDecls(
       if (!copied_decl)
         continue;
 
+      // FIXME: We should add the copied decl to the 'decls' list. This would
+      // add the copied Decl into the DeclContext and make sure that we
+      // correctly propagate that we added some Decls back to Clang.
+      // By leaving 'decls' empty we incorrectly return false from
+      // DeclContext::LoadLexicalDeclsFromExternalStorage which might cause
+      // lookup issues later on.
+      // We can't just add them for now as the ASTImporter already added the
+      // decl into the DeclContext and this would add it twice.
+
       if (FieldDecl *copied_field = dyn_cast<FieldDecl>(copied_decl)) {
         QualType copied_field_type = copied_field->getType();
 
@@ -679,12 +690,7 @@ void ClangASTSource::FillNamespaceMap(
     return;
   }
 
-  const ModuleList &target_images = m_target->GetImages();
-  std::lock_guard<std::recursive_mutex> guard(target_images.GetMutex());
-
-  for (size_t i = 0, e = target_images.GetSize(); i < e; ++i) {
-    lldb::ModuleSP image = target_images.GetModuleAtIndexUnlocked(i);
-
+  for (lldb::ModuleSP image : m_target->GetImages().Modules()) {
     if (!image)
       continue;
 
@@ -1656,14 +1662,8 @@ void ClangASTSource::CompleteNamespaceMap(
                module_sp->GetFileSpec().GetFilename());
     }
   } else {
-    const ModuleList &target_images = m_target->GetImages();
-    std::lock_guard<std::recursive_mutex> guard(target_images.GetMutex());
-
     CompilerDeclContext null_namespace_decl;
-
-    for (size_t i = 0, e = target_images.GetSize(); i < e; ++i) {
-      lldb::ModuleSP image = target_images.GetModuleAtIndexUnlocked(i);
-
+    for (lldb::ModuleSP image : m_target->GetImages().Modules()) {
       if (!image)
         continue;