[strong] Implement per-object restrictions behaviour of delete operator

test/mjsunit/strong/object-delete.js

+// Copyright 2015 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: --strong-mode --allow-natives-syntax
+
+// TODO(conradw): Track implementation of strong bit for other objects, add
+// tests.
+
+function getSloppyObjects() {
+  return [(function(){}), ({})];
+}
+
+function getStrictObjects() {
+  "use strict";
+  return [(function(){}), ({})];
+}
+
+function getStrongObjects() {
+  "use strong";
+// Strong functions can't have properties added to them, and will be tested as a

[rossberg, 2015/05/22 11:34:50]

Instead of this, why not make the test below check with Object.isExtensible, and
skip the respective bits if false?

[conradw, 2015/05/22 13:37:57]

It's kind of nasty because I interleave asserts that the property still exists
after each attempted delete. I didn't want to introduce a lot of logic just for
this one case. The actual special case test is just one extra line.

+// special case.
+  return [({})];
+}
+
+function strongFunction() {
+  "use strong";
+}
+
+function deleteFromObjectSloppy(o) {
+  return delete o.foo;
+}
+
+function deleteFromObjectKeyedSloppy(o) {
+  return delete o["foo"];

[rossberg, 2015/05/22 11:34:50]

Change this to an actual computation (e.g., Date()+""), otherwise it won't be
distinguishable from the previous (same below).

[conradw, 2015/05/22 13:37:57]

Done. Added as another case (want to keep both of these in case we do something
crazy with [] later).

+}
+
+function deleteFromObjectKeyedVarSloppy(o) {
+  var a = "foo";
+  return delete o[a];
+}
+
+function deleteFromObjectWith(o) {
+  with(o){
+    return delete foo;
+  }
+}
+
+function deleteFromObjectStrict(o) {
+  "use strict";
+  return delete o.foo;
+}
+
+function deleteFromObjectKeyedStrict(o) {
+  "use strict";
+  return delete o["foo"];
+}
+
+function deleteFromObjectKeyedVarStrict(o) {
+  "use strict";
+  var a = "foo";
+  return delete o[a];
+}
+
+function testStrongObjectDelete() {
+  "use strict";
+  let sloppyObjects = getSloppyObjects();
+  let strictObjects = getStrictObjects();
+  let strongObjects = getStrongObjects();
+  let nonStrongObjects = sloppyObjects.concat(strictObjects);
+
+  let deleteFuncsSloppy = [deleteFromObjectSloppy, deleteFromObjectKeyedSloppy,
+                           deleteFromObjectKeyedletSloppy, deleteFromObjectWith
+                          ];
+  let deleteFuncsStrict = [deleteFromObjectStrict, deleteFromObjectKeyedStrict,
+                           deleteFromObjectKeyedletStrict
+                          ];
+
+  for (let deleteFunc of deleteFuncsSloppy) {
+    for (let o of nonStrongObjects) {
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertTrue(deleteFunc(o));
+      assertFalse(o.hasOwnProperty("foo"));
+      %OptimizeFunctionOnNextCall(deleteFunc);
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertTrue(deleteFunc(o));
+      assertFalse(o.hasOwnProperty("foo"));
+      %DeoptimizeFunction(deleteFunc);
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertTrue(deleteFunc(o));
+      assertFalse(o.hasOwnProperty("foo"));
+    }
+    for (let o of strongObjects) {
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertFalse(deleteFunc(o));
+      assertTrue(o.hasOwnProperty("foo"));
+      %OptimizeFunctionOnNextCall(deleteFunc);
+      assertFalse(deleteFunc(o));
+      assertTrue(o.hasOwnProperty("foo"));
+      %DeoptimizeFunction(deleteFunc);
+      assertFalse(deleteFunc(o));
+      assertTrue(o.hasOwnProperty("foo"));
+      assertTrue(delete o);
+    }
+    assertFalse(deleteFunc(strongFunction));
+  }
+  for (let deleteFunc of deleteFuncsStrict) {
+    for (let o of nonStrongObjects) {
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertTrue(deleteFunc(o));
+      assertFalse(o.hasOwnProperty("foo"));
+      %OptimizeFunctionOnNextCall(deleteFunc);
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertTrue(deleteFunc(o));
+      assertFalse(o.hasOwnProperty("foo"));
+      %DeoptimizeFunction(deleteFunc);
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertTrue(deleteFunc(o));
+      assertFalse(o.hasOwnProperty("foo"));
+    }
+    for (let o of strongObjects) {
+      Object.defineProperty(o, "foo", {configurable:true, value:"bar"});
+      assertThrows(deleteFunc(o), TypeError);
+      assertTrue(o.hasOwnProperty("foo"));
+      %OptimizeFunctionOnNextCall(deleteFunc);
+      assertThrows(deleteFunc(o), TypeError);
+      assertTrue(o.hasOwnProperty("foo"));
+      %DeoptimizeFunction(deleteFunc);
+      assertThrows(deleteFunc(o), TypeError);
+      assertTrue(o.hasOwnProperty("foo"));
+      assertTrue(delete o);
+    }
+    assertThrows(deleteFunc(strongFunction), TypeError);
+  }
+}
+testStrongObjectDelete();