Remove support for String operator + from dart2js.

dart/lib/compiler/implementation/ssa/nodes.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.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
   R visitBitXor(HBitXor node);
@@ skipping 1379 matching lines @@
 
   // TODO(1603): The class should be marked as abstract.
   abstract BinaryOperation get operation();
 }
 
 class HAdd extends HBinaryArithmetic {
   HAdd(HStatic target, HInstruction left, HInstruction right)
       : super(target, left, right);
   accept(HVisitor visitor) => visitor.visitAdd(this);
 
-  bool get builtin() {
-    return (left.isNumber() && right.isNumber())
-            || (left.isString() && right.isString())
-            || (left.isString() && right is HConstant);
-  }
+  bool get builtin() => left.isNumber() && right.isNumber();

[kasperl, 2012/06/18 11:35:55]

This isn't needed anymore.

[ahe, 2012/06/18 11:47:19]

Because this is what the superclass does already. I'll fix this in a follow-up
CL.

 
   HType computeTypeFromInputTypes() {
     if (left.isInteger() && right.isInteger()) return left.propagatedType;
     if (left.isNumber()) {
       if (left.isDouble() || right.isDouble()) return HType.DOUBLE;
       return HType.NUMBER;
     }
-    if (left.isString()) return HType.STRING;
     return HType.UNKNOWN;
   }
 
   HType computeDesiredTypeForNonTargetInput(HInstruction input) {
     // If the desired output type is an integer we want two integers as input.
     if (propagatedType.isInteger()) {
       return HType.INTEGER;
     }
-    // TODO(floitsch): remove string specialization once string+ is removed
-    // from dart2js.
-    if (propagatedType.isString() || left.isString() || right.isString()) {
-      return HType.STRING;
-    }
     // If the desired output is a number or any of the inputs is a number
     // ask for a number. Note that we might return the input's (say 'left')
     // type depending on its (the 'left's) type. But that shouldn't matter.
     if (propagatedType.isNumber() || left.isNumber() || right.isNumber()) {
       return HType.NUMBER;
     }
     return HType.UNKNOWN;
   }
 
   HType get likelyType() {
-    if (left.isString() || right.isString()) return HType.STRING;
     if (left.isTypeUnknown() || left.isNumber()) return HType.NUMBER;
     return HType.UNKNOWN;
   }
 
   AddOperation get operation() => const AddOperation();
 
   int typeCode() => 5;
   bool typeEquals(other) => other is HAdd;
   bool dataEquals(HInstruction other) => true;
 }
@@ skipping 1146 matching lines @@
   HBasicBlock get start() => expression.start;
   HBasicBlock get end() {
     // We don't create a switch block if there are no cases.
     assert(!statements.isEmpty());
     return statements.last().end;
   }
 
   bool accept(HStatementInformationVisitor visitor) =>
       visitor.visitSwitchInfo(this);
 }