[debug-wrapper] Further extend the debug wrapper

test/mjsunit/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);