Revision: 12547
Author: [email protected]
Date: Wed Sep 19 04:52:33 2012
Log: Fix setting array length to zero for slow elements.
[email protected]
BUG=chromium:146910
TEST=mjsunit/regress/regress-crbug-146910
Review URL: https://codereview.chromium.org/10937026
http://code.google.com/p/v8/source/detail?r=12547
Added:
/branches/bleeding_edge/test/mjsunit/regress/regress-crbug-146910.js
Modified:
/branches/bleeding_edge/src/elements.cc
=======================================
--- /dev/null
+++ /branches/bleeding_edge/test/mjsunit/regress/regress-crbug-146910.js
Wed Sep 19 04:52:33 2012
@@ -0,0 +1,38 @@
+// 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.
+
+var x = [];
+assertSame(0, x.length);
+assertSame(undefined, x[0]);
+
+Object.defineProperty(x, '0', { value: 7, configurable: false });
+assertSame(1, x.length);
+assertSame(7, x[0]);
+
+x.length = 0;
+assertSame(1, x.length);
+assertSame(7, x[0]);
=======================================
--- /branches/bleeding_edge/src/elements.cc Mon Jul 30 01:34:26 2012
+++ /branches/bleeding_edge/src/elements.cc Wed Sep 19 04:52:33 2012
@@ -1268,7 +1268,30 @@
JSArray* array,
Object* length_object,
uint32_t length) {
- if (length == 0) {
+ Heap* heap = array->GetHeap();
+ int capacity = dict->Capacity();
+ uint32_t new_length = length;
+ uint32_t old_length = static_cast<uint32_t>(array->length()->Number());
+ if (new_length < old_length) {
+ // Find last non-deletable element in range of elements to be
+ // deleted and adjust range accordingly.
+ for (int i = 0; i < capacity; i++) {
+ Object* key = dict->KeyAt(i);
+ if (key->IsNumber()) {
+ uint32_t number = static_cast<uint32_t>(key->Number());
+ if (new_length <= number && number < old_length) {
+ PropertyDetails details = dict->DetailsAt(i);
+ if (details.IsDontDelete()) new_length = number + 1;
+ }
+ }
+ }
+ if (new_length != length) {
+ MaybeObject* maybe_object = heap->NumberFromUint32(new_length);
+ if (!maybe_object->To(&length_object)) return maybe_object;
+ }
+ }
+
+ if (new_length == 0) {
// If the length of a slow array is reset to zero, we clear
// the array and flush backing storage. This has the added
// benefit that the array returns to fast mode.
@@ -1276,45 +1299,22 @@
MaybeObject* maybe_obj = array->ResetElements();
if (!maybe_obj->ToObject(&obj)) return maybe_obj;
} else {
- uint32_t new_length = length;
- uint32_t old_length =
static_cast<uint32_t>(array->length()->Number());
- if (new_length < old_length) {
- // Find last non-deletable element in range of elements to be
- // deleted and adjust range accordingly.
- Heap* heap = array->GetHeap();
- int capacity = dict->Capacity();
- for (int i = 0; i < capacity; i++) {
- Object* key = dict->KeyAt(i);
- if (key->IsNumber()) {
- uint32_t number = static_cast<uint32_t>(key->Number());
- if (new_length <= number && number < old_length) {
- PropertyDetails details = dict->DetailsAt(i);
- if (details.IsDontDelete()) new_length = number + 1;
- }
+ // Remove elements that should be deleted.
+ int removed_entries = 0;
+ Object* the_hole_value = heap->the_hole_value();
+ for (int i = 0; i < capacity; i++) {
+ Object* key = dict->KeyAt(i);
+ if (key->IsNumber()) {
+ uint32_t number = static_cast<uint32_t>(key->Number());
+ if (new_length <= number && number < old_length) {
+ dict->SetEntry(i, the_hole_value, the_hole_value);
+ removed_entries++;
}
}
- if (new_length != length) {
- MaybeObject* maybe_object = heap->NumberFromUint32(new_length);
- if (!maybe_object->To(&length_object)) return maybe_object;
- }
-
- // Remove elements that should be deleted.
- int removed_entries = 0;
- Object* the_hole_value = heap->the_hole_value();
- for (int i = 0; i < capacity; i++) {
- Object* key = dict->KeyAt(i);
- if (key->IsNumber()) {
- uint32_t number = static_cast<uint32_t>(key->Number());
- if (new_length <= number && number < old_length) {
- dict->SetEntry(i, the_hole_value, the_hole_value);
- removed_entries++;
- }
- }
- }
-
- // Update the number of elements.
- dict->ElementsRemoved(removed_entries);
}
+
+ // Update the number of elements.
+ dict->ElementsRemoved(removed_entries);
}
return length_object;
}
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