[TypeFeedbackVector] Root literal arrays in function literals slots

test/mjsunit/strong-rooted-literals.js

Index: test/mjsunit/strong-rooted-literals.js
diff --git a/test/mjsunit/strong-rooted-literals.js b/test/mjsunit/strong-rooted-literals.js
new file mode 100644
index 0000000000000000000000000000000000000000..87ba966c1f0c0b6b2cbe2346eac1a278c4d83b86
--- /dev/null
+++ b/test/mjsunit/strong-rooted-literals.js
@@ -0,0 +1,40 @@
+// Copyright 2016 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.
+
+// Flags: --allow-natives-syntax --expose-gc
+
+// Make sure literals are strongly rooted and safe from weak-code deopts.
+(function() {
+  function foo() {
+    var a = { y: 0 };
+    a.y = 1;
+    return a;
+  }
+
+  foo();
+  foo();
+  %OptimizeFunctionOnNextCall(foo);
+  foo();
+  gc();
+  assertOptimized(foo);
+})();
+
+
+(function() {
+  function hot(o) {
+    return o.x + o.y;
+  }
+  function mapPlus(a, y) {
+    return a.map(x => hot({x, y}));
+  }
+
+  var a = [1, 2, 3];
+  print(mapPlus(a, 1));
+  print(mapPlus(a, 2));
+  %OptimizeFunctionOnNextCall(hot);
+  print(mapPlus(a, 3));
+  gc();  // BOOOM!
+  assertOptimized(hot);
+  print(mapPlus(a, 4));
+})();