Fix stale entries in optimized code map.

src/objects.cc

 // Copyright 2013 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 <iomanip>
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 9490 matching lines @@
 }
 
 
 void SharedFunctionInfo::AddToOptimizedCodeMap(
     Handle<SharedFunctionInfo> shared,
     Handle<Context> native_context,
     Handle<Code> code,
     Handle<FixedArray> literals,
     BailoutId osr_ast_id) {
   Isolate* isolate = shared->GetIsolate();
+  DCHECK(!shared->SearchOptimizedCodeMap(*native_context, osr_ast_id).code);
   DCHECK(code->kind() == Code::OPTIMIZED_FUNCTION);
   DCHECK(native_context->IsNativeContext());
   STATIC_ASSERT(kEntryLength == 4);
   Handle<FixedArray> new_code_map;
   Handle<Object> value(shared->optimized_code_map(), isolate);
   int old_length;
   if (value->IsSmi()) {
     // No optimized code map.
     DCHECK_EQ(0, Smi::cast(*value)->value());
-    new_code_map = isolate->factory()->NewFixedArray(kInitialLength);
+    new_code_map = isolate->factory()->NewFixedArray(kInitialLength, TENURED);
     old_length = kEntriesStart;
   } else {
-    // Copy old map and append one new entry.
+    // Copy old optimized code map and append one new entry.
     Handle<FixedArray> old_code_map = Handle<FixedArray>::cast(value);
-    DCHECK(!shared->SearchOptimizedCodeMap(*native_context, osr_ast_id).code);
-    new_code_map =
-        isolate->factory()->CopyFixedArrayAndGrow(old_code_map, kEntryLength);
+    new_code_map = isolate->factory()->CopyFixedArrayAndGrow(
+        old_code_map, kEntryLength, TENURED);
     old_length = old_code_map->length();
-    // Zap the old map for the sake of the heap verifier.
-    if (Heap::ShouldZapGarbage()) {
-      Object** data = old_code_map->data_start();
-      MemsetPointer(data, isolate->heap()->the_hole_value(), old_length);
-    }
+    // Zap the old map to avoid any stale entries. Note that this is required
+    // for correctness because entries are being treated weakly by the GC.
+    MemsetPointer(old_code_map->data_start(), isolate->heap()->the_hole_value(),
+                  old_length);
   }
   new_code_map->set(old_length + kContextOffset, *native_context);
   new_code_map->set(old_length + kCachedCodeOffset, *code);
   new_code_map->set(old_length + kLiteralsOffset, *literals);
   new_code_map->set(old_length + kOsrAstIdOffset,
                     Smi::FromInt(osr_ast_id.ToInt()));
 
 #ifdef DEBUG
   for (int i = kEntriesStart; i < new_code_map->length(); i += kEntryLength) {
     DCHECK(new_code_map->get(i + kContextOffset)->IsNativeContext());
@@ skipping 6318 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8