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      1 // Copyright 2006-2008 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // This files contains runtime support implemented in JavaScript.
      6 
      7 // CAUTION: Some of the functions specified in this file are called
      8 // directly from compiled code. These are the functions with names in
      9 // ALL CAPS. The compiled code passes the first argument in 'this'.
     10 
     11 
     12 // The following declarations are shared with other native JS files.
     13 // They are all declared at this one spot to avoid redeclaration errors.
     14 
     15 (function(global, utils) {
     16 
     17 %CheckIsBootstrapping();
     18 
     19 var GlobalArray = global.Array;
     20 var GlobalBoolean = global.Boolean;
     21 var GlobalString = global.String;
     22 var MakeRangeError;
     23 var MakeTypeError;
     24 var speciesSymbol;
     25 
     26 utils.Import(function(from) {
     27   MakeRangeError = from.MakeRangeError;
     28   MakeTypeError = from.MakeTypeError;
     29   speciesSymbol = from.species_symbol;
     30 });
     31 
     32 // ----------------------------------------------------------------------------
     33 
     34 
     35 /* ---------------------------------
     36    - - -   U t i l i t i e s   - - -
     37    ---------------------------------
     38 */
     39 
     40 
     41 function ToPositiveInteger(x, rangeErrorIndex) {
     42   var i = TO_INTEGER(x) + 0;
     43   if (i < 0) throw MakeRangeError(rangeErrorIndex);
     44   return i;
     45 }
     46 
     47 
     48 function MaxSimple(a, b) {
     49   return a > b ? a : b;
     50 }
     51 
     52 
     53 function MinSimple(a, b) {
     54   return a > b ? b : a;
     55 }
     56 
     57 
     58 %SetForceInlineFlag(MaxSimple);
     59 %SetForceInlineFlag(MinSimple);
     60 
     61 
     62 // ES2015 7.3.20
     63 function SpeciesConstructor(object, defaultConstructor) {
     64   var constructor = object.constructor;
     65   if (IS_UNDEFINED(constructor)) {
     66     return defaultConstructor;
     67   }
     68   if (!IS_RECEIVER(constructor)) {
     69     throw MakeTypeError(kConstructorNotReceiver);
     70   }
     71   var species = constructor[speciesSymbol];
     72   if (IS_NULL_OR_UNDEFINED(species)) {
     73     return defaultConstructor;
     74   }
     75   if (%IsConstructor(species)) {
     76     return species;
     77   }
     78   throw MakeTypeError(kSpeciesNotConstructor);
     79 }
     80 
     81 //----------------------------------------------------------------------------
     82 
     83 // NOTE: Setting the prototype for Array must take place as early as
     84 // possible due to code generation for array literals.  When
     85 // generating code for a array literal a boilerplate array is created
     86 // that is cloned when running the code.  It is essential that the
     87 // boilerplate gets the right prototype.
     88 %FunctionSetPrototype(GlobalArray, new GlobalArray(0));
     89 
     90 // ----------------------------------------------------------------------------
     91 // Exports
     92 
     93 utils.Export(function(to) {
     94   to.MaxSimple = MaxSimple;
     95   to.MinSimple = MinSimple;
     96   to.ToPositiveInteger = ToPositiveInteger;
     97   to.SpeciesConstructor = SpeciesConstructor;
     98 });
     99 
    100 })
    101