Fire 'stack' getter of error objects after GC.

test/mjsunit/stack-traces-gc.js

 // 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
 
-var a = JSON.parse('{"b":1,"c":2,"d":3,"e":4}');
-var b = JSON.parse('{"12040200":1, "a":2, "b":2}');
-var c = JSON.parse('{"24050300":1}');
-b = null;
+var sum = 0;
+
+Error.prepareStackTrace = function(error, stack) {
+  sum += error.num;
+}
+
+for (var i = 0; i < 100; i++) {
+  var error = new Error();
+  error.num = i;
+  error = undefined;
+}
+
 gc();
+assertEquals(0, sum);
+
+var array = [];
+for (var i = 0; i < 100; i++) {
+  var error = new Error();
+  error.num = i;
+  array.push(error);
+  error = undefined;
+}
+
+var expected_sum = 99 * 50;
+
 gc();
-c.a1 = 2;
-c.a2 = 2;
-c.a3 = 2;
-c.a4 = 2;
-c.a5 = 2;
-c.a6 = 2;
-c.a7 = 2;
-c.a8 = 2;
+// We expect that not all stack traces are formatted after only one GC.
+assertTrue(expected_sum > sum);
+
+for (var i = 0; i < 10; i++) gc();
+assertEquals(expected_sum, sum);