Allocate arguments object on-demand instead of at function entry....

test/mjsunit/arguments-apply.js

+// 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 ReturnArguments() {
+  return arguments;
+}
+
+function ReturnReceiver() {
+  return this;
+}
+
+
+function Global() {
+  return ReturnArguments.apply(this, arguments);
+}
+
+assertEquals(0, Global().length);
+assertEquals(1, Global(1).length);
+assertEquals(2, Global(2)[0]);
+assertEquals(2, Global(3, 4).length);
+assertEquals(3, Global(3, 4)[0]);
+assertEquals(4, Global(3, 4)[1]);
+
+
+function Local() {
+  var object = { f: ReturnArguments };
+  return object.f.apply(this, arguments);
+}
+
+assertEquals(0, Local().length);
+assertEquals(1, Local(1).length);
+assertEquals(2, Local(2)[0]);
+assertEquals(2, Local(3, 4).length);
+assertEquals(3, Local(3, 4)[0]);
+assertEquals(4, Local(3, 4)[1]);
+
+
+function ShadowArguments() {
+  var arguments = [3, 4];
+  return ReturnArguments.apply(this, arguments);
+}
+
+assertEquals(2, ShadowArguments().length);
+assertEquals(3, ShadowArguments()[0]);
+assertEquals(4, ShadowArguments()[1]);
+
+
+function NonObjectReceiver(receiver) {
+  return ReturnReceiver.apply(receiver, arguments);
+}
+
+assertEquals(42, NonObjectReceiver(42));
+assertEquals("object", typeof NonObjectReceiver(42));
+assertTrue(NonObjectReceiver(42) instanceof Number);
+assertTrue(this === NonObjectReceiver(null));
+assertTrue(this === NonObjectReceiver(void 0));
+
+
+function ShadowApply() {
+  function f() { return 42; }
+  f.apply = function() { return 87; }
+  return f.apply(this, arguments);
+}
+
+assertEquals(87, ShadowApply());
+assertEquals(87, ShadowApply(1));
+assertEquals(87, ShadowApply(1, 2));
+
+
+function CallNonFunction() {
+  var object = { apply: Function.prototype.apply };
+  return object.apply(this, arguments);
+}
+
+assertThrows(CallNonFunction, TypeError);
+
+
+// Make sure that the stack after the apply optimization is
+// in a valid state.
+function SimpleStackCheck() {
+  var sentinel = 42;
+  var result = ReturnArguments.apply(this, arguments);
+  assertTrue(result != null);
+  assertEquals(42, sentinel);
+}
+
+SimpleStackCheck();
+
+
+function ShadowArgumentsWithConstant() {
+  var arguments = null;
+  return ReturnArguments.apply(this, arguments);
+}
+
+assertEquals(0, ShadowArgumentsWithConstant().length);
+assertEquals(0, ShadowArgumentsWithConstant(1).length);
+assertEquals(0, ShadowArgumentsWithConstant(1, 2).length);
+
+
+// Make sure we can deal with unfolding lots of arguments on the
+// stack even in the presence of the apply optimizations.
+var array = new Array(2048);
+assertEquals(2048, Global.apply(this, array).length);