Revert "Add sharedfrontend package"

pkg/analyzer2dart/lib/src/identifier_semantics.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.
 
 /**
  * Code for classifying the semantics of identifiers appearing in a Dart file.
  */
 library analyzer2dart.identifierSemantics;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/element.dart';
-import 'package:sharedfrontend/elements.dart' as shared;
-import 'package:sharedfrontend/src/access_semantics.dart';
-
 
 // TODO(johnniwinther,paulberry): This should be a constant.
 final AccessSemanticsVisitor ACCESS_SEMANTICS_VISITOR =
     new AccessSemanticsVisitor();
 
+/**
+ * Enum representing the different kinds of destinations which a property
+ * access or method or function invocation might refer to.
+ */
+class AccessKind {
+  /**
+   * The destination of the access is an instance method, property, or field
+   * of a class, and thus must be determined dynamically.
+   */
+  static const AccessKind DYNAMIC = const AccessKind._('DYNAMIC');
+
+  /**
+   * The destination of the access is a function that is defined locally within
+   * an enclosing function or method.
+   */
+  static const AccessKind LOCAL_FUNCTION = const AccessKind._('LOCAL_FUNCTION');
+
+  /**
+   * The destination of the access is a variable that is defined locally within
+   * an enclosing function or method.
+   */
+  static const AccessKind LOCAL_VARIABLE = const AccessKind._('LOCAL_VARIABLE');
+
+  /**
+   * The destination of the access is a variable that is defined as a parameter
+   * to an enclosing function or method.
+   */
+  static const AccessKind PARAMETER = const AccessKind._('PARAMETER');
+
+  /**
+   * The destination of the access is a field that is defined statically within
+   * a class, or a top level variable within a library.
+   */
+  static const AccessKind STATIC_FIELD = const AccessKind._('STATIC_FIELD');
+
+  /**
+   * The destination of the access is a method that is defined statically
+   * within a class, or at top level within a library.
+   */
+  static const AccessKind STATIC_METHOD = const AccessKind._('STATIC_METHOD');
+
+  /**
+   * The destination of the access is a property getter/setter that is defined
+   * statically within a class, or at top level within a library.
+   */
+  static const AccessKind STATIC_PROPERTY =
+      const AccessKind._('STATIC_PROPERTY');
+
+  /**
+   * The destination of the access is a toplevel class, function typedef, mixin
+   * application, or the built-in type "dynamic".
+   */
+  static const AccessKind TOPLEVEL_TYPE = const AccessKind._('TOPLEVEL_TYPE');
+
+  /**
+   * The destination of the access is a type parameter of the enclosing class.
+   */
+  static const AccessKind TYPE_PARAMETER = const AccessKind._('TYPE_PARAMETER');
+
+  final String name;
+
+  const AccessKind._(this.name);
+
+  String toString() => name;
+}
+
+/**
+ * Data structure used to classify the semantics of a property access or method
+ * or function invocation.
+ */
+// TODO(paulberry,johnniwinther): Support index operations in AccessSemantics.
+class AccessSemantics {
+  /**
+   * The kind of access.
+   */
+  final AccessKind kind;
+
+  /**
+   * The identifier being used to access the property, method, or function.
+   */
+  final SimpleIdentifier identifier;
+
+  /**
+   * The element being accessed, if statically known.  This will be null if
+   * [kind] is DYNAMIC or if the element is undefined (e.g. an attempt to
+   * access a non-existent static method in a class).
+   */
+  final Element element;
+
+  /**
+   * The class containing the element being accessed, if this is a static
+   * reference to an element in a class.  This will be null if [kind] is
+   * DYNAMIC, LOCAL_FUNCTION, LOCAL_VARIABLE, PARAMETER, TOPLEVEL_CLASS, or
+   * TYPE_PARAMETER, or if the element being accessed is defined at toplevel
+   * within a library.
+   *
+   * Note: it is possible for [classElement] to be non-null and for [element]
+   * to be null; for example this occurs if the element being accessed is a
+   * non-existent static method or field inside an existing class.
+   */
+  final ClassElement classElement;
+
+  // TODO(paulberry): would it also be useful to store the libraryElement?
+
+  /**
+   * When [kind] is DYNAMIC, the expression whose runtime type determines the
+   * class in which [identifier] should be looked up.  Null if the expression
+   * is implicit "this".
+   *
+   * When [kind] is not DYNAMIC, this field is always null.
+   */
+  final Expression target;
+
+  /**
+   * True if this is an invocation of a method, or a call on a property.
+   */
+  final bool isInvoke;
+
+  AccessSemantics.dynamic(this.identifier, this.target, {this.isInvoke: false})
+      : kind = AccessKind.DYNAMIC,
+        element = null,
+        classElement = null;
+
+  AccessSemantics.localFunction(this.identifier, this.element, {this.isInvoke:
+      false})
+      : kind = AccessKind.LOCAL_FUNCTION,
+        classElement = null,
+        target = null;
+
+  AccessSemantics.localVariable(this.identifier, this.element, {this.isInvoke:
+      false})
+      : kind = AccessKind.LOCAL_VARIABLE,
+        classElement = null,
+        target = null;
+
+  AccessSemantics.parameter(this.identifier, this.element, {this.isInvoke:
+      false})
+      : kind = AccessKind.PARAMETER,
+        classElement = null,
+        target = null;
+
+  AccessSemantics.staticField(this.identifier, this.element, this.classElement,
+      {this.isInvoke: false})
+      : kind = AccessKind.STATIC_FIELD,
+        target = null;
+
+  AccessSemantics.staticMethod(this.identifier, this.element, this.classElement,
+      {this.isInvoke: false})
+      : kind = AccessKind.STATIC_METHOD,
+        target = null;
+
+  AccessSemantics.staticProperty(this.identifier, this.element,
+      this.classElement, {this.isInvoke: false})
+      : kind = AccessKind.STATIC_PROPERTY,
+        target = null;
+
+  AccessSemantics.toplevelType(this.identifier, this.element, {this.isInvoke:
+      false})
+      : kind = AccessKind.TOPLEVEL_TYPE,
+        classElement = null,
+        target = null;
+
+  AccessSemantics.typeParameter(this.identifier, this.element, {this.isInvoke:
+      false})
+      : kind = AccessKind.TYPE_PARAMETER,
+        classElement = null,
+        target = null;
+
+  /**
+   * True if this is a read access to a property, or a method tear-off.  Note
+   * that both [isRead] and [isWrite] will be true in the case of a
+   * read-modify-write operation (e.g. "+=").
+   */
+  bool get isRead => !isInvoke && identifier.inGetterContext();
+
+  /**
+   * True if this is a write access to a property, or an (erroneous) attempt to
+   * write to a method.  Note that both [isRead] and [isWrite] will be true in
+   * the case of a read-modify-write operation (e.g. "+=").
+   */
+  bool get isWrite => identifier.inSetterContext();
+
+  String toString() {
+    StringBuffer sb = new StringBuffer();
+    sb.write('AccessSemantics[');
+    sb.write('kind=$kind,');
+    if (isRead && isWrite) {
+      assert(!isInvoke);
+      sb.write('read/write,');
+    } else if (isRead) {
+      sb.write('read,');
+    } else if (isWrite) {
+      sb.write('write,');
+    } else if (isInvoke) {
+      sb.write('call,');
+    }
+    if (element != null) {
+      sb.write('element=');
+      if (classElement != null) {
+        sb.write('${classElement.name}.');
+      }
+      sb.write('${element}');
+    } else {
+      if (target == null) {
+        sb.write('target=this.$identifier');
+      } else {
+        sb.write('target=$target.$identifier');
+      }
+    }
+    sb.write(']');
+    return sb.toString();
+  }
+}
+
 // TODO(johnniwinther,paulberry): This should extend a non-recursive visitor.
 class AccessSemanticsVisitor extends RecursiveAstVisitor<AccessSemantics> {
   /**
    * Return the semantics for [node].
    */
   @override
   AccessSemantics visitMethodInvocation(MethodInvocation node) {
     Expression target = node.realTarget;
     Element staticElement = node.methodName.staticElement;
     if (target == null) {
       if (staticElement is FunctionElement) {
         if (staticElement.enclosingElement is CompilationUnitElement) {
           return new AccessSemantics.staticMethod(
-              node.methodName.name,
+              node.methodName,
               staticElement,
               null,
               isInvoke: true);
         } else {
           return new AccessSemantics.localFunction(
-              node.methodName.name,
+              node.methodName,
               staticElement,
               isInvoke: true);
         }
       } else if (staticElement is MethodElement && staticElement.isStatic) {
         return new AccessSemantics.staticMethod(
-            node.methodName.name,
+            node.methodName,
             staticElement,
             staticElement.enclosingElement,
             isInvoke: true);
       } else if (staticElement is PropertyAccessorElement) {
         if (staticElement.isSynthetic) {
           if (staticElement.enclosingElement is CompilationUnitElement) {
             return new AccessSemantics.staticField(
-                node.methodName.name,
+                node.methodName,
                 staticElement.variable,
                 null,
                 isInvoke: true);
           } else if (staticElement.isStatic) {
-            shared.Element classElement = staticElement.enclosingElement;
             return new AccessSemantics.staticField(
-                node.methodName.name,
+                node.methodName,
                 staticElement.variable,
-                classElement,
+                staticElement.enclosingElement,
                 isInvoke: true);
           }
         } else {
           if (staticElement.enclosingElement is CompilationUnitElement) {
             return new AccessSemantics.staticProperty(
-                node.methodName.name,
+                node.methodName,
                 staticElement,
                 null,
                 isInvoke: true);
           } else if (staticElement.isStatic) {
-            shared.Element classElement = staticElement.enclosingElement;
             return new AccessSemantics.staticProperty(
-                node.methodName.name,
+                node.methodName,
                 staticElement,
-                classElement,
+                staticElement.enclosingElement,
                 isInvoke: true);
           }
         }
       } else if (staticElement is LocalVariableElement) {
         return new AccessSemantics.localVariable(
-            node.methodName.name,
+            node.methodName,
             staticElement,
             isInvoke: true);
       } else if (staticElement is ParameterElement) {
         return new AccessSemantics.parameter(
-            node.methodName.name,
+            node.methodName,
             staticElement,
             isInvoke: true);
       } else if (staticElement is TypeParameterElement) {
         return new AccessSemantics.typeParameter(
-            node.methodName.name,
+            node.methodName,
             staticElement,
             isInvoke: true);
       } else if (staticElement is ClassElement ||
           staticElement is FunctionTypeAliasElement ||
           staticElement is DynamicElementImpl) {
         return new AccessSemantics.toplevelType(
-            node.methodName.name,
+            node.methodName,
             staticElement,
             isInvoke: true);
       }
     } else if (target is Identifier) {
       Element targetStaticElement = target.staticElement;
       if (targetStaticElement is PrefixElement) {
         if (staticElement == null) {
           return new AccessSemantics.dynamic(
-              node.methodName.name,
+              node.methodName,
               null,
               isInvoke: true);
         } else if (staticElement is PropertyAccessorElement) {
           if (staticElement.isSynthetic) {
             return new AccessSemantics.staticField(
-                node.methodName.name,
+                node.methodName,
                 staticElement.variable,
                 null,
                 isInvoke: true);
           } else {
             return new AccessSemantics.staticProperty(
-                node.methodName.name,
+                node.methodName,
                 staticElement,
                 null,
                 isInvoke: true);
           }
         } else if (staticElement is TypeParameterElement) {
           return new AccessSemantics.typeParameter(
-              node.methodName.name,
+              node.methodName,
               staticElement,
               isInvoke: true);
         } else if (staticElement is ClassElement ||
             staticElement is FunctionTypeAliasElement) {
           return new AccessSemantics.toplevelType(
-              node.methodName.name,
+              node.methodName,
               staticElement,
               isInvoke: true);
         } else {
           return new AccessSemantics.staticMethod(
-              node.methodName.name,
+              node.methodName,
               staticElement,
               null,
               isInvoke: true);
         }
       } else if (targetStaticElement is ClassElement) {
         if (staticElement is PropertyAccessorElement) {
           if (staticElement.isSynthetic) {
             return new AccessSemantics.staticField(
-                node.methodName.name,
+                node.methodName,
                 staticElement.variable,
                 targetStaticElement,
                 isInvoke: true);
           } else {
             return new AccessSemantics.staticProperty(
-                node.methodName.name,
+                node.methodName,
                 staticElement,
                 targetStaticElement,
                 isInvoke: true);
           }
         } else {
           return new AccessSemantics.staticMethod(
-              node.methodName.name,
+              node.methodName,
               staticElement,
               targetStaticElement,
               isInvoke: true);
         }
       }
     }
-    return new AccessSemantics.dynamic(
-        node.methodName.name, target, isInvoke: true);
+    return new AccessSemantics.dynamic(node.methodName, target, isInvoke: true);
   }
 
   /**
    * Return the access semantics for [node].
    */
   @override
   AccessSemantics visitPrefixedIdentifier(PrefixedIdentifier node) {
     return _classifyPrefixed(node.prefix, node.identifier);
   }
 
   /**
    * Return the access semantics for [node].
    */
   @override
   AccessSemantics visitPropertyAccess(PropertyAccess node) {
     if (node.target is Identifier) {
       return _classifyPrefixed(node.target, node.propertyName);
     } else {
-      return new AccessSemantics.dynamic(
-          node.propertyName.name,
-          node.realTarget,
-          isRead: node.propertyName.inGetterContext(),
-          isWrite: node.propertyName.inSetterContext());
+      return new AccessSemantics.dynamic(node.propertyName, node.realTarget);
     }
   }
 
   /**
    * Return the access semantics for [node].
    *
    * Note: if [node] is the right hand side of a [PropertyAccess] or
    * [PrefixedIdentifier], or the method name of a [MethodInvocation], the return
    * value is null, since the semantics are determined by the parent.  In
    * practice these cases should never arise because the parent will visit the
@@ skipping 15 matching lines @@
         (parent is MethodInvocation && parent.methodName == node)) {
       // The access semantics are determined by the parent.
       return null;
     }
     // TODO(paulberry): handle PrefixElement.
     Element staticElement = node.staticElement;
     if (staticElement is PropertyAccessorElement) {
       if (staticElement.isSynthetic) {
         if (staticElement.enclosingElement is CompilationUnitElement) {
           return new AccessSemantics.staticField(
-              node.name,
+              node,
               staticElement.variable,
-              null,
-              isRead: node.inGetterContext(),
-              isWrite: node.inSetterContext());
+              null);
         } else if (staticElement.isStatic) {
-          shared.Element classElement = staticElement.enclosingElement;
           return new AccessSemantics.staticField(
-              node.name,
+              node,
               staticElement.variable,
-              classElement,
-              isRead: node.inGetterContext(),
-              isWrite: node.inSetterContext());
+              staticElement.enclosingElement);
         }
       } else {
         if (staticElement.enclosingElement is CompilationUnitElement) {
+          return new AccessSemantics.staticProperty(node, staticElement, null);
+        } else if (staticElement.isStatic) {
           return new AccessSemantics.staticProperty(
-              node.name,
+              node,
               staticElement,
-              null,
-              isRead: node.inGetterContext(),
-              isWrite: node.inSetterContext());
-        } else if (staticElement.isStatic) {
-          shared.Element classElement = staticElement.enclosingElement;
-          return new AccessSemantics.staticProperty(
-              node.name,
-              staticElement,
-              classElement,
-              isRead: node.inGetterContext(),
-              isWrite: node.inSetterContext());
+              staticElement.enclosingElement);
         }
       }
     } else if (staticElement is LocalVariableElement) {
-      return new AccessSemantics.localVariable(
-          node.name,
-          staticElement,
-          isRead: node.inGetterContext(),
-          isWrite: node.inSetterContext());
+      return new AccessSemantics.localVariable(node, staticElement);
     } else if (staticElement is ParameterElement) {
-      return new AccessSemantics.parameter(
-          node.name,
-          staticElement,
-          isRead: node.inGetterContext(),
-          isWrite: node.inSetterContext());
+      return new AccessSemantics.parameter(node, staticElement);
     } else if (staticElement is FunctionElement) {
       if (staticElement.enclosingElement is CompilationUnitElement) {
-        return new AccessSemantics.staticMethod(
-            node.name,
-            staticElement,
-            null,
-            isRead: node.inGetterContext(),
-            isWrite: node.inSetterContext());
+        return new AccessSemantics.staticMethod(node, staticElement, null);
       } else {
-        return new AccessSemantics.localFunction(
-            node.name,
-            staticElement,
-            isRead: node.inGetterContext(),
-            isWrite: node.inSetterContext());
+        return new AccessSemantics.localFunction(node, staticElement);
       }
     } else if (staticElement is MethodElement && staticElement.isStatic) {
       return new AccessSemantics.staticMethod(
-          node.name,
+          node,
           staticElement,
-          staticElement.enclosingElement,
-          isRead: node.inGetterContext(),
-          isWrite: node.inSetterContext());
+          staticElement.enclosingElement);
     } else if (staticElement is TypeParameterElement) {
-      return new AccessSemantics.typeParameter(
-          node.name,
-          staticElement,
-          isRead: node.inGetterContext(),
-          isWrite: node.inSetterContext());
+      return new AccessSemantics.typeParameter(node, staticElement);
     } else if (staticElement is ClassElement ||
         staticElement is FunctionTypeAliasElement ||
         staticElement is DynamicElementImpl) {
-      return new AccessSemantics.toplevelType(
-          node.name,
-          staticElement,
-          isRead: node.inGetterContext(),
-          isWrite: node.inSetterContext());
+      return new AccessSemantics.toplevelType(node, staticElement);
     }
-    return new AccessSemantics.dynamic(
-        node.name,
-        null,
-        isRead: node.inGetterContext(),
-        isWrite: node.inSetterContext());
+    return new AccessSemantics.dynamic(node, null);
   }
 
   /**
    * Helper function for classifying an expression of type
    * Identifier.SimpleIdentifier.
    */
   AccessSemantics _classifyPrefixed(Identifier lhs, SimpleIdentifier rhs) {
     Element lhsElement = lhs.staticElement;
     Element rhsElement = rhs.staticElement;
     if (lhsElement is PrefixElement) {
       if (rhsElement is PropertyAccessorElement) {
         if (rhsElement.isSynthetic) {
           return new AccessSemantics.staticField(
-              rhs.name,
+              rhs,
               rhsElement.variable,
-              null,
-              isRead: rhs.inGetterContext(),
-              isWrite: rhs.inSetterContext());
+              null);
         } else {
-          return new AccessSemantics.staticProperty(
-              rhs.name,
-              rhsElement,
-              null,
-              isRead: rhs.inGetterContext(),
-              isWrite: rhs.inSetterContext());
+          return new AccessSemantics.staticProperty(rhs, rhsElement, null);
         }
       } else if (rhsElement is FunctionElement) {
-        return new AccessSemantics.staticMethod(
-            rhs.name,
-            rhsElement,
-            null,
-            isRead: rhs.inGetterContext(),
-            isWrite: rhs.inSetterContext());
+        return new AccessSemantics.staticMethod(rhs, rhsElement, null);
       } else if (rhsElement is ClassElement ||
-                 rhsElement is FunctionTypeAliasElement) {
-        return new AccessSemantics.toplevelType(
-            rhs.name,
-            rhsElement,
-            isRead: rhs.inGetterContext(),
-            isWrite: rhs.inSetterContext());
+          rhsElement is FunctionTypeAliasElement) {
+        return new AccessSemantics.toplevelType(rhs, rhsElement);
       } else {
-        return new AccessSemantics.dynamic(
-            rhs.name,
-            null,
-            isRead: rhs.inGetterContext(),
-            isWrite: rhs.inSetterContext());
+        return new AccessSemantics.dynamic(rhs, null);
       }
     } else if (lhsElement is ClassElement) {
       if (rhsElement is PropertyAccessorElement && rhsElement.isSynthetic) {
         return new AccessSemantics.staticField(
-            rhs.name,
+            rhs,
             rhsElement.variable,
-            lhsElement,
-            isRead: rhs.inGetterContext(),
-            isWrite: rhs.inSetterContext());
+            lhsElement);
       } else if (rhsElement is MethodElement) {
-        return new AccessSemantics.staticMethod(
-            rhs.name,
-            rhsElement,
-            lhsElement,
-            isRead: rhs.inGetterContext(),
-            isWrite: rhs.inSetterContext());
+        return new AccessSemantics.staticMethod(rhs, rhsElement, lhsElement);
       } else {
-        return new AccessSemantics.staticProperty(
-            rhs.name,
-            rhsElement,
-            lhsElement,
-            isRead: rhs.inGetterContext(),
-            isWrite: rhs.inSetterContext());
+        return new AccessSemantics.staticProperty(rhs, rhsElement, lhsElement);
       }
     } else {
-      return new AccessSemantics.dynamic(
-          rhs.name,
-          lhs,
-          isRead: rhs.inGetterContext(),
-          isWrite: rhs.inSetterContext());
+      return new AccessSemantics.dynamic(rhs, lhs);
     }
   }
 }