Resolve typedefs.

lib/compiler/implementation/resolver.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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   Type getType(TypeAnnotation annotation);
 }
 
@@ skipping 194 matching lines @@
   TreeElements resolveParameter(Element element) {
     Node tree = element.parseNode(compiler);
     ResolverVisitor visitor =
         new ResolverVisitor(compiler, element.enclosingElement);
     initializerDo(tree, visitor.visit);
     return visitor.mapping;
   }
 
   Type resolveTypeAnnotation(Element element, TypeAnnotation annotation) {
     if (annotation === null) return compiler.types.dynamicType;
-    ResolverVisitor visitor = new ResolverVisitor(compiler, element);
-    Type result = visitor.resolveTypeAnnotation(annotation);
+    Scope context = new TopScope(element.getLibrary());

[ahe, 2012/06/22 08:59:11]

Why are you calling a "scope" a "context"?

+    Type result;
+    Element contextElement = element.getEnclosingClassOrTypedef();
+    if (contextElement !== null &&
+        (contextElement.isTypedef() || contextElement.isClass())) {
+      var typeDefinition = contextElement;
+      context = new TypeVariablesScope(context, contextElement,

[ahe, 2012/06/22 08:59:11]

Why is this not set up when resolving the type alias?

This seems very ad-hoc to me. I'm not sure I understand this method. Something
appears very wrong in that it tries to solve a type annotation in the context of
an element.

+                                       typeDefinition.typeParameters);
+      TypeResolver typeResolver = new TypeResolver(compiler);
+      result = typeResolver.resolveTypeAnnotation(annotation,
+                                                  inContext: context,
+                                                  onFailure: warning);
+    } else {
+      ResolverVisitor visitor = new ResolverVisitor(compiler, element);
+      result = visitor.resolveTypeAnnotation(annotation);
+    }
     if (result === null) {
       // TODO(karklose): warning.
       return compiler.types.dynamicType;
     }
     return result;
   }
 
   void resolveClass(ClassElement element) {
     if (element.isResolved) return;
     measure(() {
@@ skipping 11 matching lines @@
           compiler.parser.measure(() => element.parseNode(compiler));
       return measure(() => SignatureResolver.analyze(
           compiler, node.parameters, node.returnType, element));
     });
   }
 
   FunctionSignature resolveTypedef(TypedefElement element) {
     return compiler.withCurrentElement(element, () {
       Typedef node =
           compiler.parser.measure(() => element.parseNode(compiler));
-      return measure(() => SignatureResolver.analyze(
-          compiler, node.formals, node.returnType, element));
+      TypedefResolverVisitor visitor =
+          new TypedefResolverVisitor(compiler, element.getLibrary(), element);
+      return measure(() => visitor.visit(node));
     });
   }
 
   FunctionType computeFunctionType(Element element,
                                    FunctionSignature signature) {
     LinkBuilder<Type> parameterTypes = new LinkBuilder<Type>();
     for (Link<Element> link = signature.requiredParameters;
          !link.isEmpty();
          link = link.tail) {
        parameterTypes.addLast(link.head.computeType(compiler));
        // TODO(karlklose): optional parameters.
     }
     return new FunctionType(signature.returnType,
                             parameterTypes.toLink(),
                             element);
   }
 
   error(Node node, MessageKind kind, [arguments = const []]) {
     ResolutionError message = new ResolutionError(kind, arguments);
     compiler.reportError(node, message);
   }
+
+  warning(Node node, MessageKind kind, [arguments = const []]) {
+    ResolutionWarning message = new ResolutionWarning(kind, arguments);
+    compiler.reportWarning(node, message);
+  }
 }
 
 class InitializerResolver {
   final ResolverVisitor visitor;
   final Map<SourceString, Node> initialized;
   Link<Node> initializers;
   bool hasSuper;
 
   InitializerResolver(this.visitor)
     : initialized = new Map<SourceString, Node>(), hasSuper = false;
@@ skipping 1249 matching lines @@
     }
     visitIn(node.formals, scope);
     visitIn(node.block, scope);
   }
 
   visitTypedef(Typedef node) {
     unimplemented(node, 'typedef');
   }
 }
 
-class ClassResolverVisitor extends CommonResolverVisitor<Type> {
+class TypeDefinitionVisitor extends CommonResolverVisitor<Type> {
   Scope context;
-  ClassElement classElement;
+  LibraryElement library;
+  Element enclosing;
+  Function report;
 
-  ClassResolverVisitor(Compiler compiler, LibraryElement library,
-                       ClassElement this.classElement)
-    : context = new TopScope(library),
-      super(compiler);
+  visitTypeRequired(Node node) {
+    Function oldReport = report;
+    report = error;
+    Type result = super.visit(node);
+    report = oldReport;
+    return result;
+  }
 
-  Type visitClassNode(ClassNode node) {
-    compiler.ensure(classElement !== null);
-    compiler.ensure(!classElement.isResolved);
-    final Link<Node> parameters =
-        node.typeParameters !== null ? node.typeParameters.nodes
-                                     : const EmptyLink<TypeVariable>();
+  TypeDefinitionVisitor(Compiler compiler, LibraryElement library,
+                        Element this.enclosing)
+    : this.library = library,
+      context = new TopScope(library),
+      super(compiler) {
+    report = warning;
+  }
+
+  abstract Map<SourceString, Element> get typeParameters();
+
+  Type visitTypeAnnotation(TypeAnnotation node) {
+    return visit(node.typeName);
+  }
+
+  Type visitIdentifier(Identifier node) {
+    // TODO(karlklose): use a TypeResolver here.
+    if (node.source.stringValue === 'void') return compiler.types.voidType;
+    Element element = context.lookup(node.source);
+    if (element === null) {
+      report(node, MessageKind.CANNOT_RESOLVE_TYPE, [node]);
+      return null;
+    } else if (!element.impliesType() && !element.isTypeVariable()) {
+      report(node, MessageKind.NOT_A_TYPE, [node]);
+      return null;
+    } else {
+      if (element.isClass()) {
+        compiler.resolver.toResolve.add(element);
+      }
+      if (element.isTypeVariable()) {
+        TypeVariableElement variableElement = element;
+        return variableElement.type;
+      } else {
+        return element.computeType(compiler);
+      }
+    }
+    return null;
+  }
+
+  Type visitSend(Send node) {
+    Identifier prefix = node.receiver.asIdentifier();
+    if (prefix === null) {
+      report(node.receiver, MessageKind.NOT_A_PREFIX, [node.receiver]);
+      return null;
+    }
+    Element element = context.lookup(prefix.source);
+    if (element === null || element.kind !== ElementKind.PREFIX) {
+      report(node.receiver, MessageKind.NOT_A_PREFIX, [node.receiver]);
+      return null;
+    }
+    PrefixElement prefixElement = element;
+    Identifier selector = node.selector.asIdentifier();
+    var e = prefixElement.lookupLocalMember(selector.source);
+    if (e === null || !e.impliesType()) {
+      report(node.selector, MessageKind.CANNOT_RESOLVE_TYPE, [node.selector]);
+      return null;
+    }
+    return e.computeType(compiler);
+  }
+
+  createTypeVariables(NodeList node) {
+    if (node === null) return;
     // Create types and elements for type variable.
-    for (Link<Node> link = parameters; !link.isEmpty(); link = link.tail) {
+    for (Link<Node> link = node.nodes; !link.isEmpty(); link = link.tail) {
       TypeVariable typeNode = link.head;
       SourceString variableName = typeNode.name.source;
       TypeVariableType variableType = new TypeVariableType(variableName);
       TypeVariableElement variableElement =
-          new TypeVariableElement(variableName, classElement, node,
+          new TypeVariableElement(variableName, enclosing, typeNode,
                                   variableType);
       variableType.element = variableElement;
-      classElement.typeParameters[variableName] = variableElement;
-      context = new TypeVariablesScope(context, classElement);
+      typeParameters[variableName] = variableElement;
     }
+  }
+
+  visitNodeList(NodeList node) {
+    if (node === null) return;
     // Resolve the bounds of type variables.
-    for (Link<Node> link = parameters; !link.isEmpty(); link = link.tail) {
+    for (Link<Node> link = node.nodes; !link.isEmpty(); link = link.tail) {
       TypeVariable typeNode = link.head;
       SourceString variableName = typeNode.name.source;
-      TypeVariableElement variableElement =
-          classElement.typeParameters[variableName];
+      TypeVariableElement variableElement = typeParameters[variableName];
       if (typeNode.bound !== null) {
         Type boundType = visit(typeNode.bound);
         if (boundType !== null && boundType.element == variableElement) {
-          warning(node, MessageKind.CYCLIC_TYPE_VARIABLE,
-                  [variableElement.name]);
+          report(node, MessageKind.CYCLIC_TYPE_VARIABLE,
+                 [variableElement.name]);
         } else if (boundType !== null) {
           variableElement.bound = boundType;
         } else {
           variableElement.bound = compiler.objectClass.computeType(compiler);
         }
       }
     }
+  }
+}
+
+class TypedefResolverVisitor extends TypeDefinitionVisitor {
+  TypedefElement get typedefElement() => enclosing;
+  get typeParameters() => typedefElement.typeParameters;
+
+  TypedefResolverVisitor(Compiler compiler, LibraryElement library,
+                         TypedefElement typedefElement)
+    : super(compiler, library, typedefElement);
+
+  visitVariableDefinitions(VariableDefinitions variables) {
+    return visit(variables.type);
+  }
+
+  visitTypedef(Typedef node) {
+    createTypeVariables(node.typeParameters);
+    FunctionType type = new FunctionType(compiler.types.dynamicType,
+                                         null, typedefElement);
+    typedefElement.cachedType = type;
+    context = new TypeVariablesScope(context, enclosing, typeParameters);
+    Type returnType = visit(node.returnType);
+    if (returnType === null) {
+      returnType = compiler.types.dynamicType;
+    } else if (returnType.element === typedefElement) {
+      warning(node.returnType, MessageKind.CYCLIC_TYPEDEF);
+      returnType = compiler.types.dynamicType;
+    }
+    LinkBuilder<Type> formalsTypes = new LinkBuilder<Type>();
+    TypeResolver typeResolver = new TypeResolver(compiler);
+    for (Link<Node> formals = node.formals.nodes;
+         !formals.isEmpty();
+         formals = formals.tail) {
+      if (formals.head.asNodeList() !== null) {
+        // If there is a NodeList in the formal parameter list, it is the list
+        // of optional parameters.
+        // TODO(karlklose): support optional parameters.
+        break;
+      }
+      Type formalType = visit(formals.head);
+      if (formalType === null) {
+        formalType = compiler.types.dynamicType;
+      } else {
+        if (formalType.element === typedefElement) {
+          warning(formals.head, MessageKind.CYCLIC_TYPEDEF);
+          formalType = compiler.types.dynamicType;
+        }
+      }
+      formalsTypes.addLast(formalType);
+    }
+    type.parameterTypes = formalsTypes.toLink();
+    // Resolve type parameter bounds.
+    visit(node.typeParameters);
+  }
+}
+
+class ClassResolverVisitor extends TypeDefinitionVisitor {
+  ClassElement get classElement() => enclosing;
+
+  get typeParameters() => classElement.typeParameters;
+
+  ClassResolverVisitor(Compiler compiler, LibraryElement library,
+                       ClassElement classElement)
+    : super(compiler, library, classElement);
+
+  Type visitClassNode(ClassNode node) {
+    compiler.ensure(classElement !== null);
+    compiler.ensure(!classElement.isResolved);
+    createTypeVariables(node.typeParameters);
+    // Resolve type paramters.
+    context = new TypeVariablesScope(context, enclosing, typeParameters);
+    visit(node.typeParameters);
     // Find super type.
-    Type supertype = visit(node.superclass);
+    Type supertype = visitTypeRequired(node.superclass);
     if (supertype !== null && supertype.element.isExtendable()) {
       classElement.supertype = supertype;
       if (isBlackListed(supertype)) {
         error(node.superclass, MessageKind.CANNOT_EXTEND, [supertype]);
       }
     } else if (supertype !== null) {
       error(node.superclass, MessageKind.TYPE_NAME_EXPECTED);
     }
     final objectElement = compiler.objectClass;
     if (classElement !== objectElement && classElement.supertype === null) {
       if (objectElement === null) {
         compiler.internalError("Internal error: cannot resolve Object",
                                node: node);
       } else if (!objectElement.isResolved) {
         compiler.resolver.toResolve.add(objectElement);
       }
       classElement.supertype = new InterfaceType(objectElement);
     }
     if (node.defaultClause !== null) {
-      classElement.defaultClass = visit(node.defaultClause);
+      classElement.defaultClass = visitTypeRequired(node.defaultClause);
     }
     for (Link<Node> link = node.interfaces.nodes;
          !link.isEmpty();
          link = link.tail) {
-      Type interfaceType = visit(link.head);
+      Type interfaceType = visitTypeRequired(link.head);
       if (interfaceType !== null && interfaceType.element.isExtendable()) {
         classElement.interfaces =
             classElement.interfaces.prepend(interfaceType);
         if (isBlackListed(interfaceType)) {
           error(link.head, MessageKind.CANNOT_IMPLEMENT, [interfaceType]);
         }
       } else {
         error(link.head, MessageKind.TYPE_NAME_EXPECTED);
       }
     }
     calculateAllSupertypes(classElement, new Set<ClassElement>());
     addDefaultConstructorIfNeeded(classElement);
     return classElement.computeType(compiler);
   }
 
-  Type visitTypeAnnotation(TypeAnnotation node) {
-    return visit(node.typeName);
-  }
-
-  Type visitIdentifier(Identifier node) {
-    Element element = context.lookup(node.source);
-    if (element === null) {
-      error(node, MessageKind.CANNOT_RESOLVE_TYPE, [node]);
-      return null;
-    } else if (!element.impliesType() && !element.isTypeVariable()) {
-      error(node, MessageKind.NOT_A_TYPE, [node]);
-      return null;
-    } else {
-      if (element.isClass()) {
-        compiler.resolver.toResolve.add(element);
-      }
-      if (element.isTypeVariable()) {
-        TypeVariableElement variableElement = element;
-        return variableElement.type;
-      } else if (element.isTypedef()) {
-        compiler.unimplemented('visitIdentifier for typedefs', node: node);
-      } else {
-        // TODO(ngeoffray): Use type variables.
-        return element.computeType(compiler);
-      }
-    }
-    return null;
-  }
-
-  Type visitSend(Send node) {
-    Identifier prefix = node.receiver.asIdentifier();
-    if (prefix === null) {
-      error(node.receiver, MessageKind.NOT_A_PREFIX, [node.receiver]);
-      return null;
-    }
-    Element element = context.lookup(prefix.source);
-    if (element === null || element.kind !== ElementKind.PREFIX) {
-      error(node.receiver, MessageKind.NOT_A_PREFIX, [node.receiver]);
-      return null;
-    }
-    PrefixElement prefixElement = element;
-    Identifier selector = node.selector.asIdentifier();
-    var e = prefixElement.lookupLocalMember(selector.source);
-    if (e === null || !e.impliesType()) {
-      error(node.selector, MessageKind.CANNOT_RESOLVE_TYPE, [node.selector]);
-      return null;
-    }
-    return e.computeType(compiler);
-  }
-
   Link<Type> getOrCalculateAllSupertypes(ClassElement cls,
                                          [Set<ClassElement> seen]) {
     Link<Type> allSupertypes = cls.allSupertypes;
     if (allSupertypes !== null) return allSupertypes;
     if (seen === null) {
       seen = new Set<ClassElement>();
     }
     if (seen.contains(cls)) {
       error(cls.parseNode(compiler),
             MessageKind.CYCLIC_CLASS_HIERARCHY,
@@ skipping 337 matching lines @@
 class Scope {
   final Element element;
   final Scope parent;
 
   Scope(this.parent, this.element);
   abstract Element add(Element element);
   abstract Element lookup(SourceString name);
 }
 
 class TypeVariablesScope extends Scope {
-  TypeVariablesScope(parent, ClassElement element) : super(parent, element);
+  final Map<SourceString, TypeVariableElement> variables;
+
+  TypeVariablesScope(parent, element, this.variables) : super(parent, element);
+
   Element add(Element newElement) {
     throw "Cannot add element to TypeVariableScope";
   }
+
   Element lookup(SourceString name) {
-    ClassElement cls = element;
-    Element result = cls.lookupTypeParameter(name);
+    Element result = variables[name];
     if (result !== null) return result;
     if (parent !== null) return parent.lookup(name);
   }
 }
 
 class MethodScope extends Scope {
   final Map<SourceString, Element> elements;
 
   MethodScope(Scope parent, Element element)
     : super(parent, element), this.elements = new Map<SourceString, Element>();
@@ skipping 42 matching lines @@
 
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) {
     return library.find(name);
   }
 
   Element add(Element newElement) {
     throw "Cannot add an element in the top scope";
   }
 }