Temporarily disable deferencing for libstdcpp shared_ptr data formatter

Summary:
We have noticed a significant performance issue using .debug_names which is triggered from shared_ptr/weak_ptr summary and synthetic
children providers.
This is diff temporarily disables deferencing in the data formatters to avoid the expensive code path.
See T164523815 for more details.

Test Plan: Adfinder locals window immediately shows up.

Reviewers: gclayton, wanyi, hyubo, #lldb_team

Reviewed By: wanyi

Subscribers: #lldb_team

Differential Revision: https://phabricator.intern.facebook.com/D49614423

Tasks: T164523815

Author: jeffreytan81

lldb/source/Plugins/Language/CPlusPlus/LibStdcpp.cpp

@@ -336,17 +336,20 @@ bool lldb_private::formatters::LibStdcppSmartPointerSummaryProvider(
     return true;
   }
 
-  Status error;
-  ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
-  if (pointee_sp && error.Success()) {
-    if (pointee_sp->DumpPrintableRepresentation(
-            stream, ValueObject::eValueObjectRepresentationStyleSummary,
-            lldb::eFormatInvalid,
-            ValueObject::PrintableRepresentationSpecialCases::eDisable,
-            false)) {
-      return true;
-    }
-  }
+  // TODO: temporary disable the summary provider deference for smart pointers
+  // because it is causing performance issues while completing certain template
+  // heavy types. We will revisit this issue after T164523815 is fixed.
+  // Status error;
+  // ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
+  // if (pointee_sp && error.Success()) {
+  //   if (pointee_sp->DumpPrintableRepresentation(
+  //           stream, ValueObject::eValueObjectRepresentationStyleSummary,
+  //           lldb::eFormatInvalid,
+  //           ValueObject::PrintableRepresentationSpecialCases::eDisable,
+  //           false)) {
+  //     return true;
+  //   }
+  // }
 
   stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
   return true;

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libstdcpp/smart_ptr/TestDataFormatterStdSmartPtr.py

@@ -12,6 +12,7 @@
 class StdSmartPtrDataFormatterTestCase(TestBase):
     @add_test_categories(["libstdcxx"])
     @expectedFailureAll(bugnumber="llvm.org/pr50861", compiler="gcc")
+    @skipIf("T164523815")
     def test_with_run_command(self):
         self.build()
         self.runCmd("file " + self.getBuildArtifact("a.out"), CURRENT_EXECUTABLE_SET)