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      1 // Copyright 2013 the V8 project authors. All rights reserved.
      2 // Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
      3 //
      4 // Redistribution and use in source and binary forms, with or without
      5 // modification, are permitted provided that the following conditions
      6 // are met:
      7 // 1.  Redistributions of source code must retain the above copyright
      8 //     notice, this list of conditions and the following disclaimer.
      9 // 2.  Redistributions in binary form must reproduce the above copyright
     10 //     notice, this list of conditions and the following disclaimer in the
     11 //     documentation and/or other materials provided with the distribution.
     12 //
     13 // THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
     14 // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16 // DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     17 // DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     18 // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     19 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
     20 // ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     21 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     22 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     23 
     24 description(
     25 'This tests for caller property in functions. Only functions that are called from inside of other functions and have a parent should have this property set. Tests return true when caller is found and false when the caller is null.'
     26 )
     27 function child()
     28 {
     29     return (child.caller !== null);
     30 }
     31 
     32 function parent()
     33 {
     34     return child();
     35 }
     36 
     37 var childHasCallerWhenExecutingGlobalCode = (child.caller !== null);
     38 var childHasCallerWhenCalledWithoutParent = child();
     39 var childHasCallerWhenCalledFromWithinParent = parent();
     40 
     41 shouldBe('childHasCallerWhenExecutingGlobalCode', 'false');
     42 shouldBe('childHasCallerWhenCalledWithoutParent', 'false');
     43 shouldBe('childHasCallerWhenCalledFromWithinParent', 'true')
     44 
     45 // The caller property should throw in strict mode, and a non-strict function cannot use caller to reach a strict caller (see ES5.1 15.3.5.4).
     46 function nonStrictCallee() { return nonStrictCallee.caller; }
     47 function strictCallee() { "use strict"; return strictCallee.caller; }
     48 function nonStrictCaller(x) { return x(); }
     49 function strictCaller(x) { "use strict"; return x(); }
     50 shouldBe("nonStrictCaller(nonStrictCallee)", "nonStrictCaller");
     51 shouldThrow("nonStrictCaller(strictCallee)", '"TypeError: Type error"');
     52 shouldThrow("strictCaller(nonStrictCallee)", '"TypeError: Function.caller used to retrieve strict caller"');
     53 shouldThrow("strictCaller(strictCallee)", '"TypeError: Type error"');
     54 
     55 // .caller within a bound function reaches the caller, ignoring the binding.
     56 var boundNonStrictCallee = nonStrictCallee.bind();
     57 var boundStrictCallee = strictCallee.bind();
     58 shouldBe("nonStrictCaller(boundNonStrictCallee)", "nonStrictCaller");
     59 shouldThrow("nonStrictCaller(boundStrictCallee)", '"TypeError: Type error"');
     60 shouldThrow("strictCaller(boundNonStrictCallee)", '"TypeError: Function.caller used to retrieve strict caller"');
     61 shouldThrow("strictCaller(boundStrictCallee)", '"TypeError: Type error"');
     62 
     63 // Check that .caller works (or throws) as expected, over an accessor call.
     64 function getFooGetter(x) { return Object.getOwnPropertyDescriptor(x, 'foo').get; }
     65 function getFooSetter(x) { return Object.getOwnPropertyDescriptor(x, 'foo').set; }
     66 var nonStrictAccessor = {
     67     get foo() { return getFooGetter(nonStrictAccessor).caller; },
     68     set foo(x) { if (getFooSetter(nonStrictAccessor).caller !==x) throw false; }
     69 };
     70 var strictAccessor = {
     71     get foo() { "use strict"; return getFooGetter(strictAccessor).caller; },
     72     set foo(x) { "use strict"; if (getFooSetter(strictAccessor).caller !==x) throw false; }
     73 };
     74 function nonStrictGetter(x) { return x.foo; }
     75 function nonStrictSetter(x) { x.foo = nonStrictSetter; return true; }
     76 function strictGetter(x) { "use strict"; return x.foo; }
     77 function strictSetter(x) { "use strict"; x.foo = nonStrictSetter; return true; }
     78 shouldBe("nonStrictGetter(nonStrictAccessor)", "nonStrictGetter");
     79 shouldBeTrue("nonStrictSetter(nonStrictAccessor)");
     80 shouldThrow("nonStrictGetter(strictAccessor)", '"TypeError: Type error"');
     81 shouldThrow("nonStrictSetter(strictAccessor)", '"TypeError: Type error"');
     82 shouldThrow("strictGetter(nonStrictAccessor)", '"TypeError: Function.caller used to retrieve strict caller"');
     83 shouldThrow("strictSetter(nonStrictAccessor)", '"TypeError: Function.caller used to retrieve strict caller"');
     84 shouldThrow("strictGetter(strictAccessor)", '"TypeError: Type error"');
     85 shouldThrow("strictSetter(strictAccessor)", '"TypeError: Type error"');
     86