Issue a strong mode warning for type inference that is unsafe with AST-based summaries.

pkg/analyzer/lib/src/generated/error.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.generated.error;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart' show AstNode;
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 2863 matching lines @@
     StrongModeCode.INFERRED_TYPE_CLOSURE,
     StrongModeCode.INFERRED_TYPE_LITERAL,
     StrongModeCode.INVALID_FIELD_OVERRIDE,
     StrongModeCode.INVALID_METHOD_OVERRIDE,
     StrongModeCode.INVALID_METHOD_OVERRIDE_FROM_BASE,
     StrongModeCode.INVALID_METHOD_OVERRIDE_FROM_MIXIN,
     StrongModeCode.INVALID_PARAMETER_DECLARATION,
     StrongModeCode.INVALID_SUPER_INVOCATION,
     StrongModeCode.NON_GROUND_TYPE_CHECK_INFO,
     StrongModeCode.STATIC_TYPE_ERROR,
+    StrongModeCode.UNSAFE_BLOCK_CLOSURE_INFERENCE,
 
     TodoCode.TODO,
 
     //
     // parser.dart:
     //
     ParserErrorCode.ABSTRACT_CLASS_MEMBER,
     ParserErrorCode.ABSTRACT_ENUM,
     ParserErrorCode.ABSTRACT_STATIC_METHOD,
     ParserErrorCode.ABSTRACT_TOP_LEVEL_FUNCTION,
@@ skipping 2996 matching lines @@
  *
  * These error codes tend to use the same message across different severity
  * levels, so they are grouped for clarity.
  *
  * All of these error codes also use the "STRONG_MODE_" prefix in their name.
  */
 class StrongModeCode extends ErrorCode {
   static const String _implicitCastMessage =
       'Unsound implicit cast from {0} to {1}';
 
+  static const String _unsafeBlockClosureInferenceMessage =
+      'Unsafe use of block closure in a type-inferred variable outside a '
+      'function body.  Workaround: add a type annotation for `{0}`.  See '
+      'dartbug.com/26947';
+
   static const String _typeCheckMessage =
       'Type check failed: {0} is not of type {1}';
 
   static const String _invalidOverrideMessage =
       'The type of {0}.{1} ({2}) is not a '
       'subtype of {3}.{1} ({4}).';
 
   /**
    * This is appended to the end of an error message about implicit dynamic.
    *
@@ skipping 127 matching lines @@
       'IMPLICIT_DYNAMIC_METHOD',
       "Missing type arguments for generic method '{0}<{1}>'"
       "$_implicitDynamicTip");
 
   static const StrongModeCode IMPLICIT_DYNAMIC_INVOKE = const StrongModeCode(
       ErrorType.COMPILE_TIME_ERROR,
       'IMPLICIT_DYNAMIC_INVOKE',
       "Missing type arguments for calling generic function type '{0}'"
       "$_implicitDynamicTip");
 
+  static const StrongModeCode UNSAFE_BLOCK_CLOSURE_INFERENCE =
+      const StrongModeCode(
+          ErrorType.STATIC_WARNING,
+          'UNSAFE_BLOCK_CLOSURE_INFERENCE',
+          _unsafeBlockClosureInferenceMessage);
+
   @override
   final ErrorType type;
 
   /**
    * Initialize a newly created error code to have the given [type] and [name].
    *
    * The message associated with the error will be created from the given
    * [message] template. The correction associated with the error will be
    * created from the optional [correction] template.
    */
@@ skipping 36 matching lines @@
    * Initialize a newly created error code to have the given [name].
    */
   const TodoCode(String name) : super(name, "{0}");
 
   @override
   ErrorSeverity get errorSeverity => ErrorSeverity.INFO;
 
   @override
   ErrorType get type => ErrorType.TODO;
 }