Author: [email protected]
Date: Wed Jul 8 00:13:44 2009
New Revision: 2385
Added:
branches/bleeding_edge/test/mjsunit/global-deleted-property-ic.js
Modified:
branches/bleeding_edge/src/objects.cc
Log:
Fix issue with skipping global object during lookup through
the prototype chain. In case we're skipping a global object,
we have to be careful not to use ICs for the load, because
it's possible to introduce variables on the global object
without a map change.
Review URL: http://codereview.chromium.org/149316
Modified: branches/bleeding_edge/src/objects.cc
==============================================================================
--- branches/bleeding_edge/src/objects.cc (original)
+++ branches/bleeding_edge/src/objects.cc Wed Jul 8 00:13:44 2009
@@ -1711,6 +1711,10 @@
if (IsGlobalObject()) {
PropertyDetails d = property_dictionary()->DetailsAt(entry);
if (d.IsDeleted()) {
+ // We've skipped a global object during lookup, so we cannot
+ // use inline caching because the map of the global object
+ // doesn't change if the property should be re-added.
+ result->DisallowCaching();
result->NotFound();
return;
}
Added: branches/bleeding_edge/test/mjsunit/global-deleted-property-ic.js
==============================================================================
--- (empty file)
+++ branches/bleeding_edge/test/mjsunit/global-deleted-property-ic.js Wed
Jul 8 00:13:44 2009
@@ -0,0 +1,45 @@
+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// 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
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+function LoadX(obj) { return obj.x; }
+
+// Load x from the prototype of this. Make sure to initialize the IC.
+this.__proto__ = { x: 42 };
+for (var i = 0; i < 3; i++) assertEquals(42, LoadX(this));
+
+// Introduce a global variable and make sure we load that from LoadX.
+this.x = 87;
+for (var i = 0; i < 3; i++) assertEquals(87, LoadX(this));
+
+// Delete the global variable and make sure we get back to loading from
+// the prototype.
+delete this.x;
+for (var i = 0; i < 3; i++) assertEquals(42, LoadX(this));
+
+// ... and go back again to loading directly from the object.
+this.x = 99;
+for (var i = 0; i < 3; i++) assertEquals(99, LoadX(this));
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