adds array bounds checking

frog/corejs.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Generates JS helpers for dart:core. This used to be in a file "core.js".
  * Having them in Dart code means we can easily control which are generated.
  */
 // TODO(jmesserly): one idea to make this cleaner: put these as private "native"
 // methods somewhere in a library that we import. This would be rather elegant
 // because they'd get the right name collision behavior, conversions,
 // include-if-used, etc for free. Not sure if it's worth doing that.
 class CoreJs {
   // These values track if the helper is actually used. If it is we generate it.
   bool useThrow = false;
-  bool useAssert = false;
   bool useNotNullBool = false;
   bool useIndex = false;
   bool useSetIndex = false;
 
   bool useWrap0 = false;
   bool useWrap1 = false;
   bool useIsolates = false;
 
   // These helpers had to switch to a new pattern, because they can be generated
   // after everything else.
   bool _generatedTypeNameOf = false;
   bool _generatedDynamicProto = false;
   bool _generatedInherits = false;
 
+
   Map<String, String> _usedOperators;
 
   CodeWriter writer;
 
   CoreJs(): _usedOperators = {}, writer = new CodeWriter();
 
   /**
    * Generates the special operator method, e.g. $add.
    * We want to do $add(x, y) instead of x.$add(y) so it doesn't box.
    * Same idea for the other methods.
@@ skipping 18 matching lines @@
       case ':negate':
         code = _NEGATE_FUNCTION;
         break;
 
       case ':add':
         code = _ADD_FUNCTION;
         break;
 
       case ':truncdiv':
         useThrow = true;
+        // TODO(jimhug): Only do this once!
+        world.gen.markTypeUsed(
+          world.corelib.types['IntegerDivisionByZeroException']);
         code = _TRUNCDIV_FUNCTION;
         break;
 
       case ':mod':
         code = _MOD_FUNCTION;
         break;
 
       default:
         // All of the other helpers are generated the same way
         var op = TokenKind.rawOperatorFromMethod(name);
@@ skipping 38 matching lines @@
     if (useNotNullBool) {
       useThrow = true;
       w.writeln(_NOTNULL_BOOL_FUNCTION);
     }
 
     if (useThrow) {
       w.writeln(_THROW_FUNCTION);
     }
 
     if (useIndex) {
-      w.writeln(_INDEX_OPERATORS);
+      w.writeln(options.disableBoundsChecks ?
+        _INDEX_OPERATORS : _CHECKED_INDEX_OPERATORS);
     }
 
     if (useSetIndex) {
-      w.writeln(_SETINDEX_OPERATORS);
+      w.writeln(options.disableBoundsChecks ?
+        _SETINDEX_OPERATORS : _CHECKED_SETINDEX_OPERATORS);
     }
 
     if (useIsolates) {
       if (useWrap0) {
         w.writeln(_WRAP_CALL0_FUNCTION);
       }
       if (useWrap1) {
         w.writeln(_WRAP_CALL1_FUNCTION);
       }
       w.writeln(_ISOLATE_INIT_CODE);
@@ skipping 37 matching lines @@
 /** Snippet for `$eq`. */
 final String _EQ_FUNCTION = @"""
 function $eq(x, y) {
   if (x == null) return y == null;
   return (typeof(x) == 'number' && typeof(y) == 'number') ||
          (typeof(x) == 'boolean' && typeof(y) == 'boolean') ||
          (typeof(x) == 'string' && typeof(y) == 'string')
     ? x == y : x.$eq(y);
 }
 // TODO(jimhug): Should this or should it not match equals?
-Object.defineProperty(Object.prototype, '$eq', { value: function(other) { 
+Object.defineProperty(Object.prototype, '$eq', { value: function(other) {
   return this === other;
 }, enumerable: false, writable: true, configurable: true });""";
 
 /** Snippet for `$bit_not`. */
 final String _BIT_NOT_FUNCTION = @"""
 function $bit_not(x) {
   return (typeof(x) == 'number') ? ~x : x.$bit_not();
 }""";
 
 /** Snippet for `$negate`. */
@@ skipping 75 matching lines @@
         if (entry.map.hasOwnProperty(tag)) {
           method = methods[entry.tag];
           if (method) break;
         }
       }
     }
     method = method || methods.Object;
     var proto = Object.getPrototypeOf(obj);
     if (!proto.hasOwnProperty(name)) {
       Object.defineProperty(proto, name,
-        { value: method, enumerable: false, writable: true, 
+        { value: method, enumerable: false, writable: true,
         configurable: true });
     }
 
     return method.apply(this, Array.prototype.slice.call(arguments));
   };
   $dynamicBind.methods = methods;
   Object.defineProperty(Object.prototype, name, { value: $dynamicBind,
       enumerable: false, writable: true, configurable: true});
   return methods;
 }
@@ skipping 92 matching lines @@
 // prototype. TODO(jmesserly): make this go away by handling index more
 // like a normal method.
 final String _INDEX_OPERATORS = @"""
 Object.defineProperty(Object.prototype, '$index', { value: function(i) {
   var proto = Object.getPrototypeOf(this);
   if (proto !== Object) {
     proto.$index = function(i) { return this[i]; }
   }
   return this[i];
 }, enumerable: false, writable: true, configurable: true});
-Object.defineProperty(Array.prototype, '$index', { value: function(i) { 
-  return this[i]; 
+Object.defineProperty(Array.prototype, '$index', { value: function(i) {
+  return this[i];
 }, enumerable: false, writable: true, configurable: true});
-Object.defineProperty(String.prototype, '$index', { value: function(i) { 
-  return this[i]; 
+Object.defineProperty(String.prototype, '$index', { value: function(i) {
+  return this[i];
 }, enumerable: false, writable: true, configurable: true});""";
 
+final String _CHECKED_INDEX_OPERATORS = @"""
+Object.defineProperty(Object.prototype, '$index', { value: function(i) {
+  var proto = Object.getPrototypeOf(this);
+  if (proto !== Object) {
+    proto.$index = function(i) { return this[i]; }
+  }
+  return this[i];
+}, enumerable: false, writable: true, configurable: true});
+Object.defineProperty(Array.prototype, '$index', { value: function(index) {
+  var i = index | 0;
+  if (i !== index) {
+    throw new IllegalArgumentException('index is not int');
+  } else if (i < 0 || i >= this.length) {
+    throw new IndexOutOfRangeException(index);
+  }
+  return this[i];
+}, enumerable: false, writable: true, configurable: true});
+Object.defineProperty(String.prototype, '$index', { value: function(i) {
+  return this[i];
+}, enumerable: false, writable: true, configurable: true});""";
+
+
+
 /** Snippet for `$setindex` in Object, Array, and String. */
-// TODO(jimhug): Add array bounds checking in checked mode
-/*
-function $inlineArrayIndexCheck(array, index) {
-  if (index >= 0 && index < array.length) {
-    return index;
-  }
-  native__ArrayJsUtil__throwIndexOutOfRangeException(index);
-}*/
 final String _SETINDEX_OPERATORS = @"""
 Object.defineProperty(Object.prototype, '$setindex', { value: function(i, value) {
   var proto = Object.getPrototypeOf(this);
   if (proto !== Object) {
     proto.$setindex = function(i, value) { return this[i] = value; }
   }
   return this[i] = value;
 }, enumerable: false, writable: true, configurable: true});
-Object.defineProperty(Array.prototype, '$setindex', { value: function(i, value) { 
-  return this[i] = value; }, enumerable: false, writable: true, 
+Object.defineProperty(Array.prototype, '$setindex', { value: function(i, value) {
+  return this[i] = value; }, enumerable: false, writable: true,
+  configurable: true});""";
+
+final String _CHECKED_SETINDEX_OPERATORS = @"""
+Object.defineProperty(Object.prototype, '$setindex', { value: function(i, value) {
+  var proto = Object.getPrototypeOf(this);
+  if (proto !== Object) {
+    proto.$setindex = function(i, value) { return this[i] = value; }
+  }
+  return this[i] = value;
+}, enumerable: false, writable: true, configurable: true});
+Object.defineProperty(Array.prototype, '$setindex', { value: function(index, value) {
+  var i = index | 0;
+  if (i !== index) {
+    throw new IllegalArgumentException('index is not int');
+  } else if (i < 0 || i >= this.length) {
+    throw new IndexOutOfRangeException(index);
+  }
+  return this[i] = value; }, enumerable: false, writable: true,
   configurable: true});""";
 
 /** Snippet for `$wrap_call$0`. */
 final String _WRAP_CALL0_FUNCTION = @"""
 // Wrap a 0-arg dom-callback to bind it with the current isolate:
 function $wrap_call$0(fn) { return fn && fn.wrap$call$0(); }
 Function.prototype.wrap$call$0 = function() {
   var isolateContext = $globalState.currentContext;
   var self = this;
   this.wrap$0 = function() {
@@ skipping 25 matching lines @@
 
 /** Snippet for `$wrap_call$1`, in case it was not necessary. */
 final String _EMPTY_WRAP_CALL1_FUNCTION =
     @"function $wrap_call$1(fn) { return fn; }";
 
 /** Snippet that initializes the isolates state. */
 final String _ISOLATE_INIT_CODE = @"""
 var $globalThis = this;
 var $globals = null;
 var $globalState = null;""";