Fix constant evaluation of division.

pkg/analyzer/lib/src/generated/constant.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.constant;
 
 import 'dart:collection';
@@ skipping 2764 matching lines @@
 
   @override
   NumState divide(InstanceState rightOperand) {
     assertNumOrNull(rightOperand);
     if (value == null) {
       return UNKNOWN_VALUE;
     }
     if (rightOperand is IntState) {
       int rightValue = rightOperand.value;
       if (rightValue == null) {
         return UNKNOWN_VALUE;

[danrubel, 2015/03/23 16:48:48]

DoubleState.UNKNOWN_VALUE ?

[Paul Berry, 2015/03/23 19:30:18]

This code is in the DoubleState class so it would be redundant.

       }
       return new DoubleState(value / rightValue.toDouble());
     } else if (rightOperand is DoubleState) {
       double rightValue = rightOperand.value;
       if (rightValue == null) {
         return UNKNOWN_VALUE;
       }
       return new DoubleState(value / rightValue);
     } else if (rightOperand is DynamicState || rightOperand is NumState) {
       return UNKNOWN_VALUE;
@@ skipping 1246 matching lines @@
     if (value == null) {
       return StringState.UNKNOWN_VALUE;
     }
     return new StringState(value.toString());
   }
 
   @override
   NumState divide(InstanceState rightOperand) {
     assertNumOrNull(rightOperand);
     if (value == null) {
-      if (rightOperand is DoubleState) {
-        return DoubleState.UNKNOWN_VALUE;
-      }
-      return UNKNOWN_VALUE;
+      return DoubleState.UNKNOWN_VALUE;
     }
     if (rightOperand is IntState) {
       int rightValue = rightOperand.value;
       if (rightValue == null) {
-        return UNKNOWN_VALUE;
-      } else if (rightValue == 0) {
+        return DoubleState.UNKNOWN_VALUE;
+      } else {
         return new DoubleState(value.toDouble() / rightValue.toDouble());
       }
-      return new IntState(value ~/ rightValue);
     } else if (rightOperand is DoubleState) {
       double rightValue = rightOperand.value;
       if (rightValue == null) {
         return DoubleState.UNKNOWN_VALUE;
       }
       return new DoubleState(value.toDouble() / rightValue);
     } else if (rightOperand is DynamicState || rightOperand is NumState) {
-      return UNKNOWN_VALUE;
+      return DoubleState.UNKNOWN_VALUE;
     }
     throw new EvaluationException(
         CompileTimeErrorCode.CONST_EVAL_THROWS_EXCEPTION);
   }
 
   @override
   BoolState equalEqual(InstanceState rightOperand) {
     assertBoolNumStringOrNull(rightOperand);
     return isIdentical(rightOperand);
   }
@@ skipping 594 matching lines @@
     assertNumOrNull(rightOperand);
     return UNKNOWN_VALUE;
   }
 
   @override
   StringState convertToString() => StringState.UNKNOWN_VALUE;
 
   @override
   NumState divide(InstanceState rightOperand) {
     assertNumOrNull(rightOperand);
-    return UNKNOWN_VALUE;
+    return DoubleState.UNKNOWN_VALUE;
   }
 
   @override
   BoolState equalEqual(InstanceState rightOperand) {
     assertBoolNumStringOrNull(rightOperand);
     return BoolState.UNKNOWN_VALUE;
   }
 
   @override
   BoolState greaterThan(InstanceState rightOperand) {
@@ skipping 379 matching lines @@
       return BoolState.from(_element == rightElement);
     } else if (rightOperand is DynamicState) {
       return BoolState.UNKNOWN_VALUE;
     }
     return BoolState.FALSE_STATE;
   }
 
   @override
   String toString() => _element == null ? "-unknown-" : _element.name;
 }