Improve strong-mode implementation and fix several failing tests

pkg/analyzer/lib/src/generated/resolver.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 engine.resolver;
 
 import 'dart:collection';
 
 import 'ast.dart';
 import 'constant.dart';
@@ skipping 9529 matching lines @@
   /**
    * Return `true` if the given element has an override annotation associated with it.
    *
    * @param element the element being tested
    * @return `true` if the element has an override annotation associated with it
    */
   bool _isOverride(Element element) => element != null && element.isOverride;
 }
 
 /**
+ * An AST visitor that is used to resolve the some of the nodes within a single
+ * compilation unit. The nodes that are skipped are those that are within
+ * function bodies.
+ */
+class PartialResolverVisitor extends ResolverVisitor {
+  /**
+   * A flag indicating whether the resolver is being run in strong mode.
+   */
+  bool strongMode;

[Paul Berry, 2015/09/08 16:13:30]

This could be made final.

[Brian Wilkerson, 2015/09/08 17:10:33]

Done

+
+  /**
+   * The static variables that should have types inferred for them. The list

[Paul Berry, 2015/09/08 16:13:30]

This comment is misleading, since we add *all* static variables to the list in
strong mode, not just those that need static type inference.

Consider changing to say something like "If [strongMode] is true, a list of
static variables that have been visited.  Otherwise, an empty list."

[Brian Wilkerson, 2015/09/08 17:10:33]

Actually, that's not true either. We only add static variables that have an
initializer. Comment updated.

+   * will be empty unless the resolver is being run in strong mode.
+   */
+  final List<VariableElement> staticVariables = <VariableElement>[];
+
+  /**
+   * A flag indicating whether we should discard errors while resolving the
+   * initializer for variable declarations. We do this for top-level variables
+   * and fields because their initializer will be re-resolved at a later time.
+   */
+  bool discardErrorsInInitializer = false;
+
+  /**
+   * Initialize a newly created visitor to resolve the nodes in an AST node.
+   *
+   * The [definingLibrary] is the element for the library containing the node
+   * being visited. The [source] is the source representing the compilation unit
+   * containing the node being visited. The [typeProvider] is the object used to
+   * access the types from the core library. The [errorListener] is the error
+   * listener that will be informed of any errors that are found during
+   * resolution. The [nameScope] is the scope used to resolve identifiers in the
+   * node that will first be visited.  If `null` or unspecified, a new
+   * [LibraryScope] will be created based on [definingLibrary] and
+   * [typeProvider]. The [inheritanceManager] is used to perform inheritance
+   * lookups.  If `null` or unspecified, a new [InheritanceManager] will be
+   * created based on [definingLibrary]. The [typeAnalyzerFactory] is used to
+   * create the type analyzer.  If `null` or unspecified, a type analyzer of
+   * type [StaticTypeAnalyzer] will be created.
+   */
+  PartialResolverVisitor(LibraryElement definingLibrary, Source source,
+      TypeProvider typeProvider, AnalysisErrorListener errorListener,
+      {Scope nameScope,
+      InheritanceManager inheritanceManager,
+      StaticTypeAnalyzerFactory typeAnalyzerFactory})
+      : super(definingLibrary, source, typeProvider,
+            new DisablableErrorListener(errorListener)) {
+    strongMode = definingLibrary.context.analysisOptions.strongMode;
+  }
+
+  @override
+  Object visitBlockFunctionBody(BlockFunctionBody node) {
+    return null;
+  }
+
+  @override
+  Object visitExpressionFunctionBody(ExpressionFunctionBody node) {
+    return null;
+  }
+
+  @override
+  Object visitFieldDeclaration(FieldDeclaration node) {
+    if (strongMode && node.isStatic) {
+      _addStaticVariables(node.fields.variables);
+      bool wasDiscarded = discardErrorsInInitializer;

[Paul Berry, 2015/09/08 16:13:30]

Suggestion: rename "wasDiscarded" to "wasDiscarding".  "Discarded" makes it
sound like the errors were discarded at some point in the past.

[Brian Wilkerson, 2015/09/08 17:10:33]

Done

+      discardErrorsInInitializer = true;
+      try {
+        return super.visitFieldDeclaration(node);
+      } finally {
+        discardErrorsInInitializer = wasDiscarded;
+      }
+    }
+    return super.visitFieldDeclaration(node);
+  }
+
+  @override
+  Object visitNode(AstNode node) {
+    if (discardErrorsInInitializer) {
+      AstNode parent = node.parent;
+      if (parent is VariableDeclaration && parent.initializer == node) {
+        DisablableErrorListener listener = errorListener;
+        return listener.disableWhile(() => super.visitNode(node));
+      }
+    }
+    return super.visitNode(node);
+  }
+
+  @override
+  Object visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
+    if (strongMode) {
+      _addStaticVariables(node.variables.variables);
+      bool wasDiscarded = discardErrorsInInitializer;

[Paul Berry, 2015/09/08 16:13:30]

Similar suggestion here.

[Brian Wilkerson, 2015/09/08 17:10:33]

Done

+      discardErrorsInInitializer = true;
+      try {
+        return super.visitTopLevelVariableDeclaration(node);
+      } finally {
+        discardErrorsInInitializer = wasDiscarded;
+      }
+    }
+    return super.visitTopLevelVariableDeclaration(node);
+  }
+
+  /**
+   * Add all of the [variables] with initializers to the list of variables whose
+   * type can be inferred. Technically, we only infer the types of variables
+   * that do not have a static type, but all variables with initializers
+   * potentially need to be re-resolved after inference because they might
+   * refer to a field whose type was inferred.
+   */
+  void _addStaticVariables(NodeList<VariableDeclaration> variables) {
+    for (VariableDeclaration variable in variables) {
+      if (variable.initializer != null) {
+        staticVariables.add(variable.element);
+      }
+    }
+  }
+}
+
+/**
  * Instances of the class `PubVerifier` traverse an AST structure looking for deviations from
  * pub best practices.
  */
 class PubVerifier extends RecursiveAstVisitor<Object> {
 //  static String _PUBSPEC_YAML = "pubspec.yaml";
 
   /**
    * The analysis context containing the sources to be analyzed
    */
   final AnalysisContext _context;
@@ skipping 565 matching lines @@
    * resolve the whole function.
    *
    * So, this flag is set to `true`, when just context of the function should
    * be built and the comment resolved.
    */
   bool resolveOnlyCommentInFunctionBody = false;
 
   /**
    * Initialize a newly created visitor to resolve the nodes in an AST node.
    *
-   * [definingLibrary] is the element for the library containing the node being
-   * visited.
-   * [source] is the source representing the compilation unit containing the
-   * node being visited.
-   * [typeProvider] the object used to access the types from the core library.
-   * [errorListener] the error listener that will be informed of any errors
-   * that are found during resolution.
-   * [nameScope] is the scope used to resolve identifiers in the node that will
-   * first be visited.  If `null` or unspecified, a new [LibraryScope] will be
-   * created based on [definingLibrary] and [typeProvider].
-   * [inheritanceManager] is used to perform inheritance lookups.  If `null` or
-   * unspecified, a new [InheritanceManager] will be created based on
-   * [definingLibrary].
-   * [typeAnalyzerFactory] is used to create the type analyzer.  If `null` or
-   * unspecified, a type analyzer of type [StaticTypeAnalyzer] will be created.
+   * The [definingLibrary] is the element for the library containing the node
+   * being visited. The [source] is the source representing the compilation unit
+   * containing the node being visited. The [typeProvider] is the object used to
+   * access the types from the core library. The [errorListener] is the error
+   * listener that will be informed of any errors that are found during
+   * resolution. The [nameScope] is the scope used to resolve identifiers in the
+   * node that will first be visited.  If `null` or unspecified, a new
+   * [LibraryScope] will be created based on [definingLibrary] and
+   * [typeProvider]. The [inheritanceManager] is used to perform inheritance
+   * lookups.  If `null` or unspecified, a new [InheritanceManager] will be
+   * created based on [definingLibrary]. The [typeAnalyzerFactory] is used to
+   * create the type analyzer.  If `null` or unspecified, a type analyzer of
+   * type [StaticTypeAnalyzer] will be created.
    */
   ResolverVisitor(LibraryElement definingLibrary, Source source,
       TypeProvider typeProvider, AnalysisErrorListener errorListener,
       {Scope nameScope,
       InheritanceManager inheritanceManager,
       StaticTypeAnalyzerFactory typeAnalyzerFactory})
       : super(definingLibrary, source, typeProvider, errorListener,
             nameScope: nameScope) {
     if (inheritanceManager == null) {
       this._inheritanceManager = new InheritanceManager(definingLibrary);
@@ skipping 118 matching lines @@
     }
     if (kind == ElementKind.PARAMETER) {
       return element as VariableElement;
     }
     return null;
   }
 
   /**
    * Prepares this [ResolverVisitor] to using it for incremental resolution.
    */
-  void initForIncrementalResolution() {
+  void initForIncrementalResolution([Declaration declaration = null]) {
+    if (declaration != null) {
+      Element element = declaration.element;
+      if (element is ExecutableElement) {
+        _enclosingFunction = element;
+      }
+      _commentBeforeFunction = declaration.documentationComment;
+    }
     _overrideManager.enterScope();
   }
 
   /**
    * If it is appropriate to do so, override the current type of the static and propagated elements
    * associated with the given expression with the given type. Generally speaking, it is appropriate
    * if the given type is more specific than the current type.
    *
    * @param expression the expression used to access the static and propagated elements whose types
    *          might be overridden
@@ skipping 5114 matching lines @@
     nonFields.add(node);
     return null;
   }
 
   @override
   Object visitNode(AstNode node) => node.accept(TypeResolverVisitor_this);
 
   @override
   Object visitWithClause(WithClause node) => null;
 }