Don't resolve FieldFormalParameter field if not in constructor.

pkg/analyzer/lib/src/dart/element/builder.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 analyzer.src.dart.element.builder;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 213 matching lines @@
 
   @override
   Object visitExpressionFunctionBody(ExpressionFunctionBody node) {
     return null;
   }
 
   @override
   Object visitFieldFormalParameter(FieldFormalParameter node) {
     if (node.parent is! DefaultFormalParameter) {
       SimpleIdentifier parameterName = node.identifier;
-      FieldElement field =
-          _fieldMap == null ? null : _fieldMap[parameterName.name];
       FieldFormalParameterElementImpl parameter =
           new FieldFormalParameterElementImpl.forNode(parameterName);
       _setCodeRange(parameter, node);
+      _setFieldParameterField(node, parameter);
       parameter.isConst = node.isConst;
       parameter.isExplicitlyCovariant = node.covariantKeyword != null;
       parameter.isFinal = node.isFinal;
       parameter.parameterKind = node.kind;
-      if (field != null) {
-        parameter.field = field;
-      }
       _currentHolder.addParameter(parameter);
       parameterName.staticElement = parameter;
     }
     //
     // The children of this parameter include any parameters defined on the type
     // of this parameter.
     //
     ElementHolder holder = new ElementHolder();
     _visitChildren(holder, node);
     ParameterElementImpl element = node.element;
@@ skipping 471 matching lines @@
           typeParameters[i] as TypeParameterElementImpl;
       TypeParameterTypeImpl typeParameterType =
           new TypeParameterTypeImpl(typeParameter);
       typeParameter.type = typeParameterType;
       typeArguments[i] = typeParameterType;
     }
     return typeArguments;
   }
 
   @override
-  void _setFieldParameterField(FieldFormalParameterElementImpl parameter) {
-    FieldElement field = _fieldMap == null ? null : _fieldMap[parameter.name];
-    if (field != null) {
-      parameter.field = field;
+  void _setFieldParameterField(
+      FormalParameter node, FieldFormalParameterElementImpl element) {
+    if (node.parent?.parent is ConstructorDeclaration) {
+      FieldElement field = _fieldMap == null ? null : _fieldMap[element.name];
+      if (field != null) {
+        element.field = field;
+      }
     }
   }
 }
 
 /**
  * A `CompilationUnitBuilder` builds an element model for a single compilation
  * unit.
  */
 class CompilationUnitBuilder {
   /**
@@ skipping 631 matching lines @@
   }
 
   @override
   Object visitDefaultFormalParameter(DefaultFormalParameter node) {
     NormalFormalParameter normalParameter = node.parameter;
     SimpleIdentifier parameterName = normalParameter.identifier;
     ParameterElementImpl parameter;
     if (normalParameter is FieldFormalParameter) {
       DefaultFieldFormalParameterElementImpl fieldParameter =
           new DefaultFieldFormalParameterElementImpl.forNode(parameterName);
-      _setFieldParameterField(fieldParameter);
+      _setFieldParameterField(node, fieldParameter);
       parameter = fieldParameter;
     } else {
       parameter = new DefaultParameterElementImpl.forNode(parameterName);
     }
     _setCodeRange(parameter, node);
     parameter.isConst = node.isConst;
     parameter.isExplicitlyCovariant = node.parameter.covariantKeyword != null;
     parameter.isFinal = node.isFinal;
     parameter.parameterKind = node.kind;
     // visible range
@@ skipping 106 matching lines @@
     } else if (parent is MethodDeclaration) {
       return parent.body;
     }
     return null;
   }
 
   void _setCodeRange(ElementImpl element, AstNode node) {
     element.setCodeRange(node.offset, node.length);
   }
 
-  void _setFieldParameterField(FieldFormalParameterElementImpl parameter) {}
+  void _setFieldParameterField(
+      FormalParameter node, FieldFormalParameterElementImpl element) {}
 
   /**
    * Sets the visible source range for formal parameter.
    */
   void _setParameterVisibleRange(
       FormalParameter node, ParameterElementImpl element) {
     FunctionBody body = _getFunctionBody(node);
     if (body is BlockFunctionBody || body is ExpressionFunctionBody) {
       element.setVisibleRange(body.offset, body.length);
     }
@@ skipping 96 matching lines @@
     return null;
   }
 
   /**
    * Return the lexical identifiers associated with the given [identifiers].
    */
   static List<String> _getIdentifiers(NodeList<SimpleIdentifier> identifiers) {
     return identifiers.map((identifier) => identifier.name).toList();
   }
 }