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[builtins] Properly handle DICTIONARY_ELEMENTS in Promise.all closures.

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Bug: chromium:820312
Change-Id: Ie9237a5c53ac7121e469af460a2f0ad5016d9d03
Reviewed-on: https://chromium-review.googlesource.com/957090
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51844}
This commit is contained in:
Benedikt Meurer 2018-03-09 13:47:35 +01:00 committed by Commit Bot
parent b10dc352ff
commit fd29e1d841
2 changed files with 30 additions and 0 deletions
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4
src/builtins/builtins-promise-gen.cc
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@ -1980,6 +1980,10 @@ TF_BUILTIN(PromiseAllResolveElementClosure, PromiseBuiltinsAssembler) {
{
VARIABLE(var_elements, MachineRepresentation::kTagged,
LoadElements(values_array));
// Check that the {values_array} is still in fast mode.
Node* const elements_kind = LoadMapElementsKind(LoadMap(values_array));
GotoIf(Word32Equal(elements_kind, Int32Constant(DICTIONARY_ELEMENTS)),
&runtime_set_element);
PossiblyGrowElementsCapacity(SMI_PARAMETERS, PACKED_ELEMENTS, values_array,
index, &var_elements, SmiConstant(1),
&runtime_set_element);

26
test/mjsunit/regress/regress-crbug-820312.js Normal file
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@ -0,0 +1,26 @@
// Copyright 2018 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
let arr = new Array(0x10000);
let resolve_element_closures = new Array(0x10000);
for (let i = 0; i < arr.length; i++) {
arr[i] = new Promise(() => {});
arr[i].then = ((idx, resolve) => {
resolve_element_closures[idx] = resolve;
}).bind(null, i);
}
Promise.all(arr);
// 0xffff is too large, transitions to DICTIONARY_ELEMENTS
resolve_element_closures[0xffff]();
// grows the capacity, the elements kind of the result array is still DICTIONARY_ELEMENTS, but the elements object of it is no more a dictionary.
resolve_element_closures[100]();
// You can observe that V8 crashes here in debug mode.
resolve_element_closures[0xfffe]();