Change the S-expression representation of constant values.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.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.
 
 library dart2js.ir_nodes_sexpr;
 
+import '../constants/values.dart';
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 
 /// A [Decorator] is a function used by [SExpressionStringifier] to augment the
 /// output produced for a node.  It can be provided to the constructor.
 typedef String Decorator(Node node, String s);
 
 /// Generate a Lisp-like S-expression representation of an IR node as a string.
 class SExpressionStringifier extends Visitor<String> with Indentation {
   final _Namer namer = new _Namer();
@@ skipping 135 matching lines @@
   }
 
   String visitBranch(Branch node) {
     String condition = visit(node.condition);
     String trueCont = access(node.trueContinuation);
     String falseCont = access(node.falseContinuation);
     return '$indentation(Branch $condition $trueCont $falseCont)';
   }
 
   String visitConstant(Constant node) {
-    return '(Constant ${node.expression.value.toStructuredString()})';
+    String value =
+        node.expression.value.accept(new ConstantStringifier(), null);
+    return '(Constant $value)';
   }
 
   String visitThis(This node) {
     return '(This)';
   }
 
   String visitReifyTypeVar(ReifyTypeVar node) {
     return '$indentation(ReifyTypeVar ${node.typeVariable.name})';
   }
 
@@ skipping 54 matching lines @@
     String left = access(node.left);
     String right = access(node.right);
     return '(Identical $left $right)';
   }
 
   String visitInterceptor(Interceptor node) {
     return '(Interceptor ${node.input})';
   }
 }
 
+class ConstantStringifier extends ConstantValueVisitor<String, Null> {
+  // Some of these methods are unimplemented because we haven't had a need
+  // to print such constants.  When printing is implemented, the corresponding
+  // parsing support should be added to SExpressionUnstringifier.parseConstant
+  // in the dart2js tests (currently in the file
+  // tests/compiler/dart2js/backend_dart/sexpr_unstringifier.dart).
+
+  String _failWith(ConstantValue constant) {
+    throw 'Stringification not supported for ${constant.toStructuredString()}';
+  }
+
+  String visitFunction(FunctionConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitNull(NullConstantValue constant, _) {
+    return '(Null)';
+  }
+
+  String visitInt(IntConstantValue constant, _) {
+    return '(Int ${constant.unparse()})';
+  }
+
+  String visitDouble(DoubleConstantValue constant, _) {
+    return '(Double ${constant.unparse()})';
+  }
+
+  String visitBool(BoolConstantValue constant, _) {
+    return '(Bool ${constant.unparse()})';
+  }
+
+  String visitString(StringConstantValue constant, _) {
+    return '(String ${constant.unparse()})';
+  }
+
+  String visitList(ListConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitMap(MapConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitConstructed(ConstructedConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitType(TypeConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitInterceptor(InterceptorConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitDummy(DummyConstantValue constant, _) {
+    return _failWith(constant);
+  }
+
+  String visitDeferred(DeferredConstantValue constant, _) {
+    return _failWith(constant);
+  }
+}
+
 class _Namer {
   final Map<Node, String> _names = <Node, String>{};
   int _valueCounter = 0;
   int _continuationCounter = 0;
 
   String nameParameter(Parameter parameter) {
     assert(!_names.containsKey(parameter));
     return _names[parameter] = parameter.hint.name;
   }
 
@@ skipping 15 matching lines @@
   void setReturnContinuation(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     _names[node] = 'return';
   }
 
   String getName(Node node) {
     assert(_names.containsKey(node));
     return _names[node];
   }
 }