add support for native methods in class

pkg/analyzer/lib/src/fasta/ast_builder.dart

 // Copyright (c) 2016, 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 fasta.analyzer.ast_builder;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast_factory.dart' show AstFactory;
 import 'package:analyzer/dart/ast/standard_ast_factory.dart' as standard;
 import 'package:analyzer/dart/ast/token.dart' show Token, TokenType;
@@ skipping 1272 matching lines @@
   }
 
   @override
   void beginClassDeclaration(Token beginToken, Token name) {
     assert(className == null);
     className = name.lexeme;
   }
 
   @override
   void handleNativeClause(Token nativeToken, bool hasName) {
-    push(ast.nativeClause(nativeToken, hasName ? pop() : null));
+    if (!hasName) push(NullValue.StringLiteral);
   }
 
   @override
   void endClassDeclaration(
       int interfacesCount,
       Token beginToken,
       Token classKeyword,
       Token extendsKeyword,
       Token implementsKeyword,
       Token nativeToken,
       Token endToken) {
     debugEvent("ClassDeclaration");
     _ClassBody body = pop();
-    NativeClause nativeClause = nativeToken != null ? pop() : null;
+    NativeClause nativeClause;
+    if (nativeToken != null) {
+      var nativeName = pop();
+      nativeClause = ast.nativeClause(nativeToken,
+          nativeName == NullValue.StringLiteral ? null : nativeName);
+    }
     ImplementsClause implementsClause;
     if (implementsKeyword != null) {
       List<TypeName> interfaces = popList(interfacesCount);
       implementsClause = ast.implementsClause(implementsKeyword, interfaces);
     }
     ExtendsClause extendsClause;
     WithClause withClause;
     var supertype = pop();
     if (supertype == null) {
       // No extends clause
@@ skipping 282 matching lines @@
   }
 
   @override
   void endTypeVariables(int count, Token beginToken, Token endToken) {
     debugEvent("TypeVariables");
     List<TypeParameter> typeParameters = popList(count);
     push(ast.typeParameterList(beginToken, typeParameters, endToken));
   }
 
   @override
-  void endMethod(Token getOrSet, Token beginToken, Token endToken) {
+  void endMethod(
+      Token getOrSet, Token beginToken, Token nativeToken, Token endToken) {
     debugEvent("Method");
     FunctionBody body = pop();
+    if (nativeToken != null) {
+      var nativeName = pop();
+      if (nativeName == NullValue.StringLiteral) {
+        nativeName = null;
+      }
+      if (body is EmptyFunctionBody) {
+        body = ast.nativeFunctionBody(nativeToken, nativeName, body.endToken);
+      } else {
+        // TODO(danrubel): Report error if native clause is used with
+        // non-empty function body.
+      }
+    }
     ConstructorName redirectedConstructor = null; // TODO(paulberry)
     List<ConstructorInitializer> initializers = pop() ?? const [];
     Token separator = pop();
     FormalParameterList parameters = pop();
     TypeParameterList typeParameters = pop();
     var name = pop();
     TypeAnnotation returnType = pop();
     _Modifiers modifiers = pop();
     List<Annotation> metadata = pop();
     Comment comment = pop();
@@ skipping 421 matching lines @@
       } else if (identical('var', s)) {
         finalConstOrVarKeyword = token;
       } else if (identical('covariant', s)) {
         covariantKeyword = token;
       } else {
         unhandled("$s", "modifier", token.charOffset, null);
       }
     }
   }
 }