Make cells pointing to JSObjects weak in optimized code.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3646 matching lines @@
   for (int i = 0; i < 4; i++) {
     heap->CollectAllGarbage(false);
   }
 
   // The site still exists because of our global handle, but the code is no
   // longer referred to by dependent_code().
   DependentCode::GroupStartIndexes starts(site->dependent_code());
   int index = starts.at(DependentCode::kAllocationSiteTransitionChangedGroup);
   CHECK(!(site->dependent_code()->is_code_at(index)));
 }
+
+
+TEST(CellsInOptimizedCodeAreWeak) {
+  if (i::FLAG_always_opt || !i::FLAG_crankshaft) return;
+  i::FLAG_weak_embedded_objects_in_optimized_code = true;
+  i::FLAG_allow_natives_syntax = true;
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  v8::internal::Heap* heap = CcTest::heap();
+
+  if (!isolate->use_crankshaft()) return;
+  HandleScope outer_scope(heap->isolate());
+  Handle<Code> code;
+  {
+    LocalContext context;
+    HandleScope scope(heap->isolate());
+
+    CompileRun("bar = (function() {"
+               "  function bar() {"
+               "    return foo(1);"
+               "  };"
+               "  var foo = function(x) { with (x) { return 1 + x; } };"
+               "  bar(foo);"
+               "  bar(foo);"
+               "  bar(foo);"
+               "  %OptimizeFunctionOnNextCall(bar);"
+               "  bar(foo);"
+               "  return bar;})();");
+
+    Handle<JSFunction> bar =
+        v8::Utils::OpenHandle(
+            *v8::Handle<v8::Function>::Cast(
+                CcTest::global()->Get(v8_str("bar"))));
+    code = scope.CloseAndEscape(Handle<Code>(bar->code()));
+  }
+
+  // Now make sure that a gc should get rid of the function
+  for (int i = 0; i < 4; i++) {
+    heap->CollectAllGarbage(false);

[Hannes Payer (out of office), 2014/01/14 15:04:19]

Is calling 3 times the GC not good enough? Moreover, I would call
CollectAllGarbage with Heap::kAbortIncrementalMarkingMask to make it more robust
on the stress GC builders.

[ulan, 2014/01/14 17:14:00]

I am passing Heap::kAbortIncrementalMarkingMask now.

I left the number of GCs at four, because three GCs are not collecting the
function.

+  }
+
+  ASSERT(code->marked_for_deoptimization());
+}
+
+
+TEST(ObjectsInOptimizedCodeAreWeak) {
+  if (i::FLAG_always_opt || !i::FLAG_crankshaft) return;
+  i::FLAG_weak_embedded_objects_in_optimized_code = true;
+  i::FLAG_allow_natives_syntax = true;
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  v8::internal::Heap* heap = CcTest::heap();
+
+  if (!isolate->use_crankshaft()) return;
+  HandleScope outer_scope(heap->isolate());
+  Handle<Code> code;
+  {
+    LocalContext context;
+    HandleScope scope(heap->isolate());
+
+    CompileRun("function bar() {"
+               "  return foo(1);"
+               "};"
+               "function foo(x) { with (x) { return 1 + x; } };"
+               "bar();"
+               "bar();"
+               "bar();"
+               "%OptimizeFunctionOnNextCall(bar);"
+               "bar();");
+
+    Handle<JSFunction> bar =
+        v8::Utils::OpenHandle(
+            *v8::Handle<v8::Function>::Cast(
+                CcTest::global()->Get(v8_str("bar"))));
+    code = scope.CloseAndEscape(Handle<Code>(bar->code()));
+  }
+
+  // Now make sure that a gc should get rid of the function
+  for (int i = 0; i < 10; i++) {
+    heap->CollectAllGarbage(false);

[Hannes Payer (out of office), 2014/01/14 15:04:19]

Same as above.

+  }
+
+  ASSERT(code->marked_for_deoptimization());
+}