[es6] Tail calls support.

test/mjsunit/es6/tail-call-proxies.js

+// Copyright 2016 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 --harmony-tailcalls --harmony-proxies
+"use strict";
+
+Error.prepareStackTrace = (e,s) => s;
+
+function CheckStackTrace(expected) {
+  var stack = (new Error()).stack;
+  assertEquals("CheckStackTrace", stack[0].getFunctionName());
+  for (var i = 0; i < expected.length; i++) {
+    assertEquals(expected[i].name, stack[i + 1].getFunctionName());
+  }
+}
+
+
+// Tail call proxy function when caller does not have an arguments
+// adaptor frame.
+(function test() {
+  // Caller and callee have same number of arguments.
+  function f1(a) {
+    CheckStackTrace([f1, test]);
+    return 10 + a;
+  }
+  var p1 = new Proxy(f1, {});
+  function g1(a) { return p1(2); }
+  assertEquals(12, g1(1));
+
+  // Caller has more arguments than callee.
+  function f2(a) {
+    CheckStackTrace([f2, test]);
+    return 10 + a;
+  }
+  var p2 = new Proxy(f2, {});
+  function g2(a, b, c) { return p2(2); }
+  assertEquals(12, g2(1, 2, 3));
+
+  // Caller has less arguments than callee.
+  function f3(a, b, c) {
+    CheckStackTrace([f3, test]);
+    return 10 + a + b + c;
+  }
+  var p3 = new Proxy(f3, {});
+  function g3(a) { return p3(2, 3, 4); }
+  assertEquals(19, g3(1));
+
+  // Callee has arguments adaptor frame.
+  function f4(a, b, c) {
+    CheckStackTrace([f4, test]);
+    return 10 + a;
+  }
+  var p4 = new Proxy(f4, {});
+  function g4(a) { return p4(2); }
+  assertEquals(12, g4(1));
+})();
+
+
+// Tail call proxy function when caller has an arguments adaptor frame.
+(function test() {
+  // Caller and callee have same number of arguments.
+  function f1(a) {
+    CheckStackTrace([f1, test]);
+    return 10 + a;
+  }
+  var p1 = new Proxy(f1, {});
+  function g1(a) { return p1(2); }
+  assertEquals(12, g1());
+
+  // Caller has more arguments than callee.
+  function f2(a) {
+    CheckStackTrace([f2, test]);
+    return 10 + a;
+  }
+  var p2 = new Proxy(f2, {});
+  function g2(a, b, c) { return p2(2); }
+  assertEquals(12, g2());
+
+  // Caller has less arguments than callee.
+  function f3(a, b, c) {
+    CheckStackTrace([f3, test]);
+    return 10 + a + b + c;
+  }
+  var p3 = new Proxy(f3, {});
+  function g3(a) { return p3(2, 3, 4); }
+  assertEquals(19, g3());
+
+  // Callee has arguments adaptor frame.
+  function f4(a, b, c) {
+    CheckStackTrace([f4, test]);
+    return 10 + a;
+  }
+  var p4 = new Proxy(f4, {});
+  function g4(a) { return p4(2); }
+  assertEquals(12, g4());
+})();