JezK
Edit File: debug-referenced-by.js
// Copyright 2008 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-debug-as debug // Get the Debug object exposed from the debug context global object. Debug = debug.Debug // Simple object. var a = {}; // Create mirror for the object. var mirror = debug.MakeMirror(a); // Initially one reference from the global object. assertEquals(1, mirror.referencedBy().length); assertEquals(1, mirror.referencedBy(0).length); assertEquals(1, mirror.referencedBy(1).length); assertEquals(1, mirror.referencedBy(10).length); // Add some more references from simple objects and arrays. var b = {} b.a = a; assertEquals(2, mirror.referencedBy().length); var c = {} c.a = a; c.aa = a; c.aaa = a; assertEquals(3, mirror.referencedBy().length); function d(){}; d.a = a assertEquals(4, mirror.referencedBy().length); e = [a,b,c,d]; assertEquals(5, mirror.referencedBy().length); // Simple closure. function closure_simple(p) { return function() { p = null; }; } // This adds a reference (function context). f = closure_simple(a); assertEquals(6, mirror.referencedBy().length); // This clears the reference (in function context). f() assertEquals(5, mirror.referencedBy().length); // Use closure with eval - creates arguments array. function closure_eval(p, s) { if (s) { eval(s); } return function e(s) { eval(s); }; } // This adds a references (function context). g = closure_eval(a); assertEquals(6, mirror.referencedBy().length); // Dynamically create a variable. This should create a context extension. h = closure_eval(null, "var x_"); assertEquals(6, mirror.referencedBy().length); // Adds a reference when set. h("x_ = a"); var x = mirror.referencedBy(); assertEquals(7, mirror.referencedBy().length); // Removes a reference when cleared. h("x_ = null"); assertEquals(6, mirror.referencedBy().length); // Check circular references. x = {} mirror = debug.MakeMirror(x); assertEquals(1, mirror.referencedBy().length); x.x = x; assertEquals(2, mirror.referencedBy().length); x = null; assertEquals(0, mirror.referencedBy().length); // Check many references. y = {} mirror = debug.MakeMirror(y); refs = []; for (var i = 0; i < 200; i++) { refs[i] = {'y': y}; } y = null; assertEquals(200, mirror.referencedBy().length);