Add ConstantConstructor to ConstantExpression system.

pkg/compiler/lib/src/constants/constructors.dart

Index: pkg/compiler/lib/src/constants/constructors.dart
diff --git a/pkg/compiler/lib/src/constants/constructors.dart b/pkg/compiler/lib/src/constants/constructors.dart
new file mode 100644
index 0000000000000000000000000000000000000000..3c09a94bc6086b6fdc761009017603dee8b6b718
--- /dev/null
+++ b/pkg/compiler/lib/src/constants/constructors.dart
@@ -0,0 +1,376 @@
+// Copyright (c) 2015, 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.constants.constructors;
+
+import '../elements/elements.dart';
+import 'expressions.dart';
+import 'values.dart';
+import '../dart_types.dart';
+import '../resolution/resolution.dart';
+import '../resolution/operators.dart';
+import '../resolution/semantic_visitor.dart';
+import '../resolution/send_structure.dart';
+import '../dart2jslib.dart';
+import '../tree/tree.dart';
+
+ConstantConstructor computeConstantConstructor(ResolvedAst resolvedAst) {
+  ConstantConstructorComputer visitor =
+      new ConstantConstructorComputer(resolvedAst.elements);
+  return resolvedAst.node.accept(visitor);
+}
+
+class ConstantConstructorComputer extends SemanticVisitor
+    with SemanticDeclarationResolvedMixin,
+         DeclarationResolverMixin,
+         GetBulkMixin,
+         SetBulkMixin,
+         ErrorBulkMixin,
+         InvokeBulkMixin,
+         IndexSetBulkMixin,
+         CompoundBulkMixin,
+         UnaryBulkMixin,
+         BaseBulkMixin,
+         BinaryBulkMixin,
+         PrefixBulkMixin,
+         PostfixBulkMixin,
+         NewBulkMixin,
+         InitializerBulkMixin,
+         FunctionBulkMixin,
+         VariableBulkMixin
+    implements SemanticDeclarationVisitor, SemanticSendVisitor {
+  final Map<FieldElement, ConstantExpression> fieldMap =
+      <FieldElement, ConstantExpression>{};
+  final Map<dynamic/*int|String*/, ConstantExpression> defaultValues =
+      <dynamic/*int|String*/, ConstantExpression>{};
+
+  ConstantConstructorComputer(TreeElements elements)
+      : super(elements);
+
+  SemanticDeclarationVisitor get declVisitor => this;
+
+  SemanticSendVisitor get sendVisitor => this;
+
+  ClassElement get currentClass => currentConstructor.enclosingClass;
+
+  ConstructorElement get currentConstructor => elements.analyzedElement;
+
+  apply(Node node, [_]) => node.accept(this);
+
+  visitNode(Node node) {
+    internalError(node, 'Unhandled node $node: ${node.toDebugString()}');
+  }
+
+  @override
+  bulkHandleNode(Node node, String template, _) {
+    internalError(node, template.replaceFirst('#' , '$node'));
+  }
+
+  internalError(Node node, String message) {
+    throw new UnsupportedError(message);
+  }
+
+  ConstantConstructor visitGenerativeConstructorDeclaration(
+        FunctionExpression node,
+        ConstructorElement constructor,
+        NodeList parameters,
+        NodeList initializers,
+        Node body,
+        _) {
+    applyParameters(parameters, _);
+    ConstructedConstantExpression constructorInvocation =
+        applyInitializers(initializers, _);
+    return new GenerativeConstantConstructor(
+        currentClass.thisType, defaultValues, fieldMap, constructorInvocation);
+  }
+
+  ConstantConstructor visitRedirectingGenerativeConstructorDeclaration(
+      FunctionExpression node,
+      ConstructorElement constructor,
+      NodeList parameters,
+      NodeList initializers,
+      _) {
+    applyParameters(parameters, _);
+    ConstructedConstantExpression constructorInvocation =
+        applyInitializers(initializers, _);
+    return new RedirectingGenerativeConstantConstructor(
+        defaultValues, constructorInvocation);
+  }
+
+  ConstantConstructor visitRedirectingFactoryConstructorDeclaration(
+      FunctionExpression node,
+      ConstructorElement constructor,
+      NodeList parameters,
+      InterfaceType redirectionType,
+      ConstructorElement redirectionTarget,
+      _) {
+    List<String> argumentNames = [];
+    List<ConstantExpression> arguments = [];
+    int index = 0;
+    for (ParameterElement parameter in constructor.parameters) {
+      if (parameter.isNamed) {
+        String name = parameter.name;
+        argumentNames.add(name);
+        arguments.add(new NamedArgumentReference(name));
+      } else {
+        arguments.add(new PositionalArgumentReference(index));
+      }
+      index++;
+    }
+    CallStructure callStructure = new CallStructure(index, argumentNames);
+
+    return new RedirectingFactoryConstantConstructor(
+        new ConstructedConstantExpression(null,
+            redirectionType,
+            redirectionTarget,
+            callStructure,
+            arguments));
+  }
+
+  @override
+  visitFactoryConstructorDeclaration(
+      FunctionExpression node,
+      ConstructorElement constructor,
+      NodeList parameters,
+      Node body, _) {
+    // TODO(johnniwinther): Handle constant constructors with errors.
+    internalError(node, "Factory constructor cannot be constant.");
+  }
+
+  applyParameters(NodeList parameters, _) {
+    computeParameterStructures(parameters).forEach((s) => s.dispatch(this, _));
+  }
+
+  visitParameterDeclaration(
+      VariableDefinitions node,
+      Node definition,
+      ParameterElement parameter,
+      int index,
+      _) {
+    // Do nothing.
+  }
+
+  visitOptionalParameterDeclaration(
+      VariableDefinitions node,
+      Node definition,
+      ParameterElement parameter,
+      ConstantExpression defaultValue,
+      int index,
+      _) {
+    assert(invariant(node, defaultValue != null));
+    defaultValues[index] = defaultValue;
+  }
+
+  visitNamedParameterDeclaration(
+      VariableDefinitions node,
+      Node definition,
+      ParameterElement parameter,
+      ConstantExpression defaultValue,
+      _) {
+    assert(invariant(node, defaultValue != null));
+    String name = parameter.name;
+    defaultValues[name] = defaultValue;
+  }
+
+  visitInitializingFormalDeclaration(
+      VariableDefinitions node,
+      Node definition,
+      InitializingFormalElement parameter,
+      int index,
+      _) {
+    fieldMap[parameter.fieldElement] = new PositionalArgumentReference(index);
+  }
+
+  visitOptionalInitializingFormalDeclaration(
+      VariableDefinitions node,
+      Node definition,
+      InitializingFormalElement parameter,
+      ConstantExpression defaultValue,
+      int index,
+      _) {
+    assert(invariant(node, defaultValue != null));
+    defaultValues[index] = defaultValue;
+    fieldMap[parameter.fieldElement] = new PositionalArgumentReference(index);
+  }
+
+  visitNamedInitializingFormalDeclaration(
+      VariableDefinitions node,
+      Node definition,
+      InitializingFormalElement parameter,
+      ConstantExpression defaultValue,
+      _) {
+    assert(invariant(node, defaultValue != null));
+    String name = parameter.name;
+    defaultValues[name] = defaultValue;
+    fieldMap[parameter.fieldElement] = new NamedArgumentReference(name);
+  }
+
+  /// Apply this visitor to the constructor [initializers].
+  ConstructedConstantExpression applyInitializers(NodeList initializers, _) {
+    ConstructedConstantExpression constructorInvocation;
+    if (initializers != null) {
+      for (Node initializer in initializers) {
+        InitializerStructure structure =
+            computeInitializerStructure(initializer);
+        if (structure is SuperConstructorInvokeStructure ||
+            structure is ThisConstructorInvokeStructure) {
+          constructorInvocation = structure.dispatch(this, initializer, _);
+        } else {
+          structure.dispatch(this, initializer, _);
+        }
+      }
+    }
+    if (constructorInvocation == null && !currentClass.isObject) {
+      constructorInvocation =
+          new ConstructedConstantExpression(null,
+              currentClass.supertype,
+              currentClass.superclass.lookupDefaultConstructor(),
+              CallStructure.NO_ARGS,
+              const <ConstantExpression>[]);
+    }
+    return constructorInvocation;
+  }
+
+  visitFieldInitializer(
+      SendSet node,
+      FieldElement field,
+      Node initializer,
+      _) {
+    fieldMap[field] = apply(initializer);
+  }
+
+  visitParameterGet(
+      Send node,
+      ParameterElement parameter,
+      _) {
+    if (parameter.isNamed) {
+      return new NamedArgumentReference(parameter.name);
+    } else {
+      return new PositionalArgumentReference(
+          parameter.functionDeclaration.parameters.indexOf(parameter));
+    }
+  }
+
+  ConstructedConstantExpression visitSuperConstructorInvoke(
+      Send node,
+      ConstructorElement superConstructor,
+      InterfaceType type,
+      NodeList arguments,
+      Selector selector,
+      _) {
+    List<ConstantExpression> argumentExpression =
+        arguments.nodes.map((a) => apply(a)).toList();
+    return new ConstructedConstantExpression(null,
+        type,
+        superConstructor,
+        selector.callStructure,
+        argumentExpression);
+  }
+
+  ConstructedConstantExpression visitThisConstructorInvoke(
+      Send node,
+      ConstructorElement thisConstructor,
+      NodeList arguments,
+      Selector selector,
+      _) {
+    List<ConstantExpression> argumentExpression =
+        arguments.nodes.map((a) => apply(a)).toList();
+    return new ConstructedConstantExpression(null,
+        currentClass.thisType,
+        thisConstructor,
+        selector.callStructure,
+        argumentExpression);
+  }
+
+  @override
+  ConstantExpression visitBinary(
+      Send node,
+      Node left,
+      BinaryOperator operator,
+      Node right,
+      _) {
+    return new BinaryConstantExpression(null,
+        apply(left), operator, apply(right));
+  }
+
+
+  @override
+  ConstantExpression visitUnary(
+      Send node,
+      UnaryOperator operator,
+      Node expression,
+      _) {
+    return new UnaryConstantExpression(null,
+        operator, apply(expression));
+  }
+
+  @override
+  ConstantExpression visitStaticFieldGet(
+      Send node,
+      FieldElement field,
+      _) {
+    return new VariableConstantExpression(null, field);
+  }
+
+  @override
+  ConstantExpression visitTopLevelFieldGet(
+      Send node,
+      FieldElement field,
+      _) {
+    return new VariableConstantExpression(null, field);
+  }
+
+  @override
+  ConstantExpression visitLiteralInt(LiteralInt node) {
+    return new IntConstantExpression(
+        node.value, new IntConstantValue(node.value));
+  }
+
+  @override
+  ConstantExpression visitLiteralBool(LiteralBool node) {
+    return new BoolConstantExpression(node.value, null);
+  }
+
+  @override
+  ConstantExpression visitLiteralNull(LiteralNull node) {
+    return new NullConstantExpression(new NullConstantValue());
+  }
+
+  @override
+  ConstantExpression visitLiteralString(LiteralString node) {
+    return new StringConstantExpression(node.dartString.slowToString(), null);
+  }
+
+  @override
+  ConstantExpression visitConditional(Conditional node) {
+    return new ConditionalConstantExpression(null,
+        apply(node.condition),
+        apply(node.thenExpression),
+        apply(node.elseExpression));
+  }
+
+  @override
+  ConstantExpression visitParenthesizedExpression(ParenthesizedExpression node) {
+    return apply(node.expression);
+  }
+
+  @override
+  ConstantExpression visitTopLevelFunctionInvoke(
+      Send node,
+      MethodElement function,
+      NodeList arguments,
+      CallStructure callStructure,
+      _) {
+    if (function.name != 'identical' || !function.library.isDartCore) {
+      throw new UnsupportedError("Unexpected function call: $function");
+    }
+    return new IdenticalConstantExpression(
+        null, apply(arguments.nodes.head), apply(arguments.nodes.tail.head));
+  }
+
+  @override
+  ConstantExpression visitNamedArgument(NamedArgument node) {
+    return apply(node.expression);
+  }
+}