infer field formal parameter types

pkg/analyzer/lib/src/task/strong_mode.dart

 // 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 analyzer.src.task.strong_mode;
 
 import 'dart:collection';
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 245 matching lines @@
         //
         _inferType(classElement.supertype);
         classElement.mixins.forEach(_inferType);
         classElement.interfaces.forEach(_inferType);
         //
         // Then infer the types for the members.
         //
         classElement.fields.forEach(_inferField);
         classElement.accessors.forEach(_inferExecutable);
         classElement.methods.forEach(_inferExecutable);
+        //
+        // Infer initializing formal parameter types. This must happen after
+        // field types are inferred.
+        //
+        classElement.constructors.forEach(_inferConstructorFieldFormals);
         classElement.hasBeenInferred = true;
       } finally {
         elementsBeingInferred.remove(classElement);
       }
     }
   }
 
   /**
    * If the given [fieldElement] represents a non-synthetic instance field for
    * which no type was provided, infer the type of the field.
@@ skipping 158 matching lines @@
     return true;
   }
 
   /**
    * Return `true` if the list of [elements] contains only methods.
    */
   bool _allSameElementKind(
       ExecutableElement element, List<ExecutableElement> elements) {
     return elements.every((e) => e.kind == element.kind);
   }
+
+  void _inferConstructorFieldFormals(ConstructorElement element) {
+    for (ParameterElement p in element.parameters) {
+      if (p is FieldFormalParameterElement) {
+        _inferFieldFormalParameter(p);
+      }
+    }
+  }
+
+  void _inferFieldFormalParameter(FieldFormalParameterElement element) {
+    FieldElement field = element.field;
+    if (field != null && element.hasImplicitType) {
+      (element as FieldFormalParameterElementImpl).type = field.type;
+    }
+  }
 }
 
 /**
  * A visitor that will gather all of the variables referenced within a given
  * AST structure. The collection can be restricted to contain only those
  * variables that pass a specified filter.
  */
 class VariableGatherer extends RecursiveAstVisitor {
   /**
    * The filter used to limit which variables are gathered, or `null` if no
@@ skipping 23 matching lines @@
         results.add(element);
       }
     }
   }
 }
 
 /**
  * A class of exception that is not used anywhere else.
  */
 class _CycleException implements Exception {}