Index: cfe/trunk/include/clang/AST/ASTImporter.h
===================================================================
--- cfe/trunk/include/clang/AST/ASTImporter.h
+++ cfe/trunk/include/clang/AST/ASTImporter.h
@@ -425,7 +425,7 @@
 
     /// Subclasses can override this function to observe all of the \c From ->
     /// \c To declaration mappings as they are imported.
-    virtual Decl *Imported(Decl *From, Decl *To) { return To; }
+    virtual void Imported(Decl *From, Decl *To) {}
 
     /// Store and assign the imported declaration to its counterpart.
     Decl *MapImported(Decl *From, Decl *To);
Index: cfe/trunk/lib/AST/ExternalASTMerger.cpp
===================================================================
--- cfe/trunk/lib/AST/ExternalASTMerger.cpp
+++ cfe/trunk/lib/AST/ExternalASTMerger.cpp
@@ -110,7 +110,7 @@
 
   /// Whenever a DeclContext is imported, ensure that ExternalASTSource's origin
   /// map is kept up to date.  Also set the appropriate flags.
-  Decl *Imported(Decl *From, Decl *To) override {
+  void Imported(Decl *From, Decl *To) override {
     if (auto *ToDC = dyn_cast<DeclContext>(To)) {
       const bool LoggingEnabled = Parent.LoggingEnabled();
       if (LoggingEnabled)
@@ -153,7 +153,6 @@
       ToContainer->getPrimaryContext()->setMustBuildLookupTable();
       assert(Parent.CanComplete(ToContainer));
     }
-    return To;
   }
   ASTImporter &GetReverse() { return Reverse; }
 };
Index: lldb/trunk/include/lldb/Symbol/ClangASTImporter.h
===================================================================
--- lldb/trunk/include/lldb/Symbol/ClangASTImporter.h
+++ lldb/trunk/include/lldb/Symbol/ClangASTImporter.h
@@ -262,7 +262,7 @@
 
     void ImportDefinitionTo(clang::Decl *to, clang::Decl *from);
 
-    clang::Decl *Imported(clang::Decl *from, clang::Decl *to) override;
+    void Imported(clang::Decl *from, clang::Decl *to) override;
 
     clang::Decl *GetOriginalDecl(clang::Decl *To) override;
 
Index: lldb/trunk/source/Symbol/ClangASTImporter.cpp
===================================================================
--- lldb/trunk/source/Symbol/ClangASTImporter.cpp
+++ lldb/trunk/source/Symbol/ClangASTImporter.cpp
@@ -937,7 +937,7 @@
   }
 }
 
-clang::Decl *ClangASTImporter::Minion::Imported(clang::Decl *from,
+void ClangASTImporter::Minion::Imported(clang::Decl *from,
                                                 clang::Decl *to) {
   ClangASTMetrics::RegisterClangImport();
 
@@ -1096,8 +1096,6 @@
       }
     }
   }
-
-  return clang::ASTImporter::Imported(from, to);
 }
 
 clang::Decl *ClangASTImporter::Minion::GetOriginalDecl(clang::Decl *To) {