[lldb][ClangASTImporter][NFC] Factor out completion logic out of ClangASTImporterDelegate

Upstreams two helpers that make this more readable.

Author: Michael137

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

@@ -235,6 +235,35 @@ class CompleteTagDeclsScope : public ClangASTImporter::NewDeclListener {
   clang::ASTContext *m_src_ctx;
   ClangASTImporter &importer;
 
+  void CompleteDecl(
+      Decl *decl,
+      lldb_private::ClangASTImporter::ASTContextMetadata const &to_context_md) {
+    // The decl that should be completed has to be imported into the target
+    // context from some other context.
+    assert(to_context_md.hasOrigin(decl));
+    // We should only complete decls coming from the source context.
+    assert(to_context_md.getOrigin(decl).ctx == m_src_ctx);
+
+    Decl *original_decl = to_context_md.getOrigin(decl).decl;
+
+    // Complete the decl now.
+    TypeSystemClang::GetCompleteDecl(m_src_ctx, original_decl);
+    if (auto *tag_decl = dyn_cast<TagDecl>(decl)) {
+      if (auto *original_tag_decl = dyn_cast<TagDecl>(original_decl)) {
+        if (original_tag_decl->isCompleteDefinition()) {
+          m_delegate->ImportDefinitionTo(tag_decl, original_tag_decl);
+          tag_decl->setCompleteDefinition(true);
+        }
+      }
+
+      tag_decl->setHasExternalLexicalStorage(false);
+      tag_decl->setHasExternalVisibleStorage(false);
+    } else if (auto *container_decl = dyn_cast<ObjCContainerDecl>(decl)) {
+      container_decl->setHasExternalLexicalStorage(false);
+      container_decl->setHasExternalVisibleStorage(false);
+    }
+  }
+
 public:
   /// Constructs a CompleteTagDeclsScope.
   /// \param importer The ClangASTImporter that we should observe.
@@ -257,30 +286,7 @@ class CompleteTagDeclsScope : public ClangASTImporter::NewDeclListener {
       NamedDecl *decl = m_decls_to_complete.pop_back_val();
       m_decls_already_completed.insert(decl);
 
-      // The decl that should be completed has to be imported into the target
-      // context from some other context.
-      assert(to_context_md->hasOrigin(decl));
-      // We should only complete decls coming from the source context.
-      assert(to_context_md->getOrigin(decl).ctx == m_src_ctx);
-
-      Decl *original_decl = to_context_md->getOrigin(decl).decl;
-
-      // Complete the decl now.
-      TypeSystemClang::GetCompleteDecl(m_src_ctx, original_decl);
-      if (auto *tag_decl = dyn_cast<TagDecl>(decl)) {
-        if (auto *original_tag_decl = dyn_cast<TagDecl>(original_decl)) {
-          if (original_tag_decl->isCompleteDefinition()) {
-            m_delegate->ImportDefinitionTo(tag_decl, original_tag_decl);
-            tag_decl->setCompleteDefinition(true);
-          }
-        }
-
-        tag_decl->setHasExternalLexicalStorage(false);
-        tag_decl->setHasExternalVisibleStorage(false);
-      } else if (auto *container_decl = dyn_cast<ObjCContainerDecl>(decl)) {
-        container_decl->setHasExternalLexicalStorage(false);
-        container_decl->setHasExternalVisibleStorage(false);
-      }
+      CompleteDecl(decl, *to_context_md);
 
       to_context_md->removeOrigin(decl);
     }
@@ -1370,6 +1376,18 @@ void ClangASTImporter::ASTImporterDelegate::Imported(clang::Decl *from,
              from, m_source_ctx, &to->getASTContext());
   }
 
+  if (auto *to_namespace_decl = dyn_cast<NamespaceDecl>(to)) {
+    m_main.BuildNamespaceMap(to_namespace_decl);
+    to_namespace_decl->setHasExternalVisibleStorage();
+  }
+
+  MarkDeclImported(from, to);
+}
+
+void ClangASTImporter::ASTImporterDelegate::MarkDeclImported(Decl *from,
+                                                             Decl *to) {
+  Log *log = GetLog(LLDBLog::Expressions);
+
   if (auto *to_tag_decl = dyn_cast<TagDecl>(to)) {
     to_tag_decl->setHasExternalLexicalStorage();
     to_tag_decl->getPrimaryContext()->setMustBuildLookupTable();
@@ -1384,11 +1402,6 @@ void ClangASTImporter::ASTImporterDelegate::Imported(clang::Decl *from,
         (to_tag_decl->isCompleteDefinition() ? "complete" : "incomplete"));
   }
 
-  if (auto *to_namespace_decl = dyn_cast<NamespaceDecl>(to)) {
-    m_main.BuildNamespaceMap(to_namespace_decl);
-    to_namespace_decl->setHasExternalVisibleStorage();
-  }
-
   if (auto *to_container_decl = dyn_cast<ObjCContainerDecl>(to)) {
     to_container_decl->setHasExternalLexicalStorage();
     to_container_decl->setHasExternalVisibleStorage();

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

@@ -346,6 +346,8 @@ class ClangASTImporter {
     llvm::Expected<clang::Decl *> ImportImpl(clang::Decl *From) override;
 
   private:
+    void MarkDeclImported(clang::Decl *from, clang::Decl *to);
+
     /// Decls we should ignore when mapping decls back to their original
     /// ASTContext. Used by the CxxModuleHandler to mark declarations that
     /// were created from the 'std' C++ module to prevent that the Importer