Support for parsing native function bodies with Fasta.

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' as analyzer show Token;
 import 'package:analyzer/dart/element/element.dart' show Element;
 import 'package:front_end/src/fasta/parser/parser.dart'
-    show FormalParameterType;
+    show FormalParameterType, Parser;
 import 'package:front_end/src/fasta/scanner/token.dart'
     show BeginGroupToken, Token;
 
 import 'package:front_end/src/fasta/errors.dart' show internalError;
 import 'package:front_end/src/fasta/fasta_codes.dart'
-    show FastaMessage, codeExpectedExpression;
+    show FastaMessage, codeExpectedExpression, codeExpectedFunctionBody;
 import 'package:front_end/src/fasta/kernel/kernel_builder.dart'
     show Builder, KernelLibraryBuilder, ProcedureBuilder, Scope;
 import 'package:front_end/src/fasta/parser/identifier_context.dart'
     show IdentifierContext;
 import 'package:front_end/src/fasta/quote.dart';
 import 'package:front_end/src/fasta/source/scope_listener.dart'
     show JumpTargetKind, NullValue, ScopeListener;
 import 'analyzer.dart' show toKernel;
 import 'element_store.dart'
     show
         AnalyzerLocalVariableElemment,
         AnalyzerParameterElement,
         ElementStore,
         KernelClassElement;
 import 'package:analyzer/src/dart/error/syntactic_errors.dart';
 import 'token_utils.dart' show toAnalyzerToken, toAnalyzerCommentToken;
 
 class AstBuilder extends ScopeListener {
   final AstFactory ast = standard.astFactory;
 
   final ErrorReporter errorReporter;
   final KernelLibraryBuilder library;
   final Builder member;
   final ElementStore elementStore;
 
   @override
   final Uri uri;
 
+  /**
+   * The [Parser] that uses this listener, used to parse optional parts, e.g.
+   * `native` support.
+   */
+  Parser parser;
+
   /// The name of the class currently being parsed, or `null` if no class is
   /// being parsed.
   String className;
 
   AstBuilder(this.errorReporter, this.library, this.member, this.elementStore,
       Scope scope,
       [Uri uri])
       : uri = uri ?? library.fileUri,
         super(scope);
 
@@ skipping 1047 matching lines @@
           toAnalyzerToken(closeCurlyBracket)));
     }
   }
 
   @override
   void handleInvalidExpression(Token token) {
     debugEvent("InvalidExpression");
   }
 
   @override
+  void handleInvalidFunctionBody(Token token) {
+    debugEvent("InvalidFunctionBody");
+  }
+
+  @override
   Token handleUnrecoverableError(Token token, FastaMessage message) {
-    if (message.code == codeExpectedExpression) {
+    if (message.code == codeExpectedFunctionBody) {
+      if (identical('native', token.stringValue) && parser != null) {
+        Token nativeKeyword = token;
+        Token semicolon = parser.parseLiteralString(token.next);
+        token = parser.expectSemicolon(semicolon);
+        StringLiteral name = pop();
+        pop(); // star
+        pop(); // async
+        push(ast.nativeFunctionBody(
+            toAnalyzerToken(nativeKeyword), name, toAnalyzerToken(semicolon)));
+        return token;
+      }
+    } else if (message.code == codeExpectedExpression) {
       String lexeme = token.lexeme;
       if (identical('async', lexeme) || identical('yield', lexeme)) {
         errorReporter?.reportErrorForOffset(
             ParserErrorCode.ASYNC_KEYWORD_USED_AS_IDENTIFIER,
             token.charOffset,
             token.charCount);
         push(ast.simpleIdentifier(toAnalyzerToken(token)));
         return token;
       }
     }
@@ skipping 838 matching lines @@
       } else if (identical('static', s)) {
         staticKeyword = token;
       } else if (identical('var', s)) {
         finalConstOrVarKeyword = token;
       } else {
         internalError('Unhandled modifier: $s');
       }
     }
   }
 }