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Don't clear EnumLength but rather copy the enum cache. Added regression test for crashes from chromecrash.

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Review URL: https://chromiumcodereview.appspot.com/11103036

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12704 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
verwaest@chromium.org 2012-10-11 15:33:34 +00:00
parent 942e7424e9
commit b75705f07b
2 changed files with 63 additions and 2 deletions
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5
src/objects.cc
View File

@ -1806,6 +1806,9 @@ MaybeObject* JSObject::ConvertTransitionToMapTransition(
Map* map;
DescriptorArray* new_descriptors = new_map->instance_descriptors();
DescriptorArray* old_descriptors = old_map->instance_descriptors();
if (old_descriptors->HasEnumCache()) {
new_descriptors->CopyEnumCacheFrom(old_descriptors);
}
for (Object* current = old_map;
!current->IsUndefined();
current = map->GetBackPointer()) {
@ -1813,8 +1816,6 @@ MaybeObject* JSObject::ConvertTransitionToMapTransition(
if (!map->HasTransitionArray()) break;
TransitionArray* transitions = map->transitions();
if (transitions->descriptors() != old_descriptors) break;
// Invalidate the enum caches only if the map did not own its descriptors.
if (!owned_descriptors) map->SetEnumLength(Map::kInvalidEnumCache);
transitions->set_descriptors(new_descriptors);
}
old_map->set_owns_descriptors(false);

60
test/mjsunit/regress/regress-convert-enum.js Normal file
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@ -0,0 +1,60 @@
// Copyright 2012 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.
// Flags: --expose-gc
// Create a transition tree A (no descriptors) -> B (descriptor for a) -> C
// (descriptor for a and c), that all share the descriptor array [a,c]. C is the
// owner of the descriptor array.
var o = {};
o.a = 1;
o.c = 2;
// Add a transition B -> D where D has its own descriptor array [a,b] where b is
// a constant function.
var o1 = {};
o1.a = 1;
// Install an enumeration cache in the descriptor array [a,c] at map B.
for (var x in o1) { }
o1.b = function() { return 1; };
// Return ownership of the descriptor array [a,c] to B and trim it to [a].
o = null;
gc();
// Convert the transition B -> D into a transition to B -> E so that E uses the
// instance descriptors [a,b] with b being a field.
var o2 = {};
o2.a = 1;
o2.b = 10;
// Create an object with map B and iterate over it.
var o3 = {};
o3.a = 1;
for (var y in o3) { }