implement `Invocation.typeArguments` in DDC

pkg/dev_compiler/tool/input_sdk/private/js_array.dart

 // Copyright (c) 2012, 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.
 
 part of dart._interceptors;
 
 /**
  * The interceptor class for [List]. The compiler recognizes this
  * class as an interceptor, and changes references to [:this:] to
  * actually use the receiver of the method, which is generated as an extra
  * argument added to each member.
  */
 @JsPeerInterface(name: 'Array')
 class JSArray<E> implements List<E>, JSIndexable<E> {
   const JSArray();
 
   /**
-   * Constructor for adding type parameters to an existing JavaScript Array.
-   */
-  factory JSArray.typed(allocation) =>
-      // TODO(jmesserly): skip this when E is dynamic and Object.
-      JS('-dynamic', 'dart.list(#, #)', allocation, E);
-
-  /**
    * Constructor for adding type parameters to an existing JavaScript
    * Array. Used for creating literal lists.
    */
   factory JSArray.of(allocation) {
     // TODO(sra): Move this to core.List for better readability.
     // Capture the parameterized ES6 'JSArray' class.
-    return JS('-dynamic', 'dart.setType(#, JSArray)', allocation);
+    return dart.setType(allocation, JS('', 'JSArray'));

[Leaf, 2017/07/26 00:46:31]

This change caused a dart._check to be added here, which seems to be causing a
massive performance regression.  I tested out changing just this line in google3
and saw a 5X or worse slowdown in test performance.  

I'll follow up with a CL to change this tomorrow.  I think we need to look at
alternatives to setType as well - still preliminary, but I think I'm seeing a
lot of slowdown for our pattern.

[Jennifer Messerly, 2017/07/26 01:23:00]

oh shoot, I thought I'd fixed that before landing :(. I'll fix that real quick &
TBR to remove the cast

I can also try out some alternate patterns. Since JSArray is in the SDK and
cannot be subclassed, we have a lot of options in the implementation

[Jennifer Messerly, 2017/07/26 01:33:47]

fixed in
https://codereview.chromium.org/2985063002/diff/1/pkg/dev_compiler/tool/input...

   }
 
   // TODO(jmesserly): consider a fixed array subclass instead.
   factory JSArray.markFixed(allocation) =>
-      new JSArray<E>.typed(markFixedList(allocation));
+      new JSArray<E>.of(markFixedList(allocation));
 
-  factory JSArray.markGrowable(allocation) = JSArray<E>.typed;
+  factory JSArray.markGrowable(allocation) = JSArray<E>.of;
 
   static List markFixedList(List list) {
     // Functions are stored in the hidden class and not as properties in
     // the object. We never actually look at the value, but only want
     // to know if the property exists.
     JS('void', r'#.fixed$length = Array', list);
     return JS('JSFixedArray', '#', list);
   }
 
   static List markUnmodifiableList(List list) {
@@ skipping 271 matching lines @@
     }
     if (end == null) {
       end = length;
     } else {
       if (end is! int) throw argumentErrorValue(end);
       if (end < start || end > length) {
         throw new RangeError.range(end, start, length, "end");
       }
     }
     if (start == end) return <E>[];
-    return new JSArray<E>.typed(JS('', r'#.slice(#, #)', this, start, end));
+    return new JSArray<E>.of(JS('', r'#.slice(#, #)', this, start, end));
   }
 
   Iterable<E> getRange(int start, int end) {
     RangeError.checkValidRange(start, end, this.length);
     return new SubListIterable<E>(this, start, end);
   }
 
   E get first {
     if (length > 0) return this[0];
     throw IterableElementError.noElement();
@@ skipping 184 matching lines @@
 
   bool get isEmpty => length == 0;
 
   bool get isNotEmpty => !isEmpty;
 
   String toString() => ListBase.listToString(this);
 
   List<E> toList({bool growable: true}) {
     var list = JS('', '#.slice()', this);
     if (!growable) markFixedList(list);
-    return new JSArray<E>.typed(list);
+    return new JSArray<E>.of(list);
   }
 
   Set<E> toSet() => new Set<E>.from(this);
 
   Iterator<E> get iterator => new ArrayIterator<E>(this);
 
   int get hashCode => Primitives.objectHashCode(this);
 
   bool operator ==(other) => identical(this, other);
 
@@ skipping 30 matching lines @@
         JS('int', '#', index) < 0) {
       throw diagnoseIndexError(this, index);
     }
     JS('void', r'#[#] = #', this, index, value);
   }
 
   Map<int, E> asMap() {
     return new ListMapView<E>(this);
   }
 
-  Type get runtimeType => wrapType(JS('', '#(#)', getGenericClass(List), E));
+  Type get runtimeType =>
+      dart.wrapType(JS('', '#(#)', dart.getGenericClass(List), E));
 }
 
 /**
  * Dummy subclasses that allow the backend to track more precise
  * information about arrays through their type. The CPA type inference
  * relies on the fact that these classes do not override [] nor []=.
  *
  * These classes are really a fiction, and can have no methods, since
  * getInterceptor always returns JSArray.  We should consider pushing the
  * 'isGrowable' and 'isMutable' checks into the getInterceptor implementation so
@@ skipping 35 matching lines @@
 
     if (_index >= length) {
       _current = null;
       return false;
     }
     _current = _iterable[_index];
     _index++;
     return true;
   }
 }