Link type feedback vectors to the shared function info.

src/debug/liveedit.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/debug/liveedit.h"
 
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/compiler.h"
@@ skipping 740 matching lines @@
   static void PatchFeedbackVector(FunctionInfoWrapper* compile_info_wrapper,
                                   Handle<SharedFunctionInfo> shared_info,
                                   Isolate* isolate) {
     int new_literal_count = compile_info_wrapper->GetLiteralCount();
 
     // When feedback metadata changes, we have to create new array instances.
     // Since we cannot create instances when iterating heap, we should first
     // collect all functions and fix their literal arrays.
     Handle<FixedArray> function_instances =
         CollectJSFunctions(shared_info, isolate);
-    Handle<FeedbackMetadata> feedback_metadata(
-        shared_info->feedback_metadata());
 
     for (int i = 0; i < function_instances->length(); i++) {
       Handle<JSFunction> fun(JSFunction::cast(function_instances->get(i)));
-      Handle<FeedbackVector> vector =
-          FeedbackVector::New(isolate, feedback_metadata);
-      fun->feedback_vector_cell()->set_value(*vector);
-      }
+      fun->set_feedback_vector_cell(isolate->heap()->undefined_cell());
+      // Only create feedback vectors if we already have the metadata.
+      if (shared_info->is_compiled()) JSFunction::EnsureLiterals(fun);
+    }
 
-      shared_info->set_num_literals(new_literal_count);
+    shared_info->set_num_literals(new_literal_count);
   }
 
  private:
   // Iterates all function instances in the HEAP that refers to the
   // provided shared_info.
   template<typename Visitor>
   static void IterateJSFunctions(Handle<SharedFunctionInfo> shared_info,
                                  Visitor* visitor) {
     HeapIterator iterator(shared_info->GetHeap());
     for (HeapObject* obj = iterator.next(); obj != NULL;
@@ skipping 136 matching lines @@
       isolate->debug()->RemoveDebugInfoAndClearFromShared(
           handle(shared_info->GetDebugInfo()));
     }
     shared_info->set_scope_info(new_shared_info->scope_info());
     shared_info->set_outer_scope_info(new_shared_info->outer_scope_info());
     shared_info->DisableOptimization(kLiveEdit);
     // Update the type feedback vector, if needed.
     Handle<FeedbackMetadata> new_feedback_metadata(
         new_shared_info->feedback_metadata());
     shared_info->set_feedback_metadata(*new_feedback_metadata);
+  } else {
+    shared_info->set_feedback_metadata(
+        FeedbackMetadata::cast(isolate->heap()->empty_fixed_array()));
   }
 
   int start_position = compile_info_wrapper.GetStartPosition();
   int end_position = compile_info_wrapper.GetEndPosition();
   shared_info->set_start_position(start_position);
   shared_info->set_end_position(end_position);
 
   FeedbackVectorFixer::PatchFeedbackVector(&compile_info_wrapper, shared_info,
                                            isolate);
 
@@ skipping 707 matching lines @@
     scope_info_length++;
 
     current_scope = current_scope->outer_scope();
   }
 
   return scope_info_list;
 }
 
 }  // namespace internal
 }  // namespace v8