integrating fasta parser

* start integrating fasta parser into analyzer
* extract new Scanner.fasta factory

R=paulberry@google.com

Review-Url: https://codereview.chromium.org/2948473002 .

pkg/analyzer/lib/src/dart/scanner/scanner.dart

@@ -48,10 +48,16 @@ class Scanner extends fe.Scanner {
   factory Scanner(Source source, CharacterReader reader,
           AnalysisErrorListener errorListener) =>
       fe.Scanner.useFasta
-          ? new _Scanner2(
-              source, reader.getContents(), reader.offset, errorListener)
+          ? new Scanner.fasta(source, errorListener,
+              contents: reader.getContents(), offset: reader.offset)
           : new Scanner._(source, reader, errorListener);
 
+  factory Scanner.fasta(Source source, AnalysisErrorListener errorListener,
+      {String contents, int offset: 0}) {
+    return new _Scanner2(
+        source, contents ?? source.contents.data, offset, errorListener);
+  }
+
   Scanner._(this.source, CharacterReader reader, this._errorListener)
       : super.create(reader);
 

pkg/analyzer/lib/src/generated/parser.dart

@@ -2,6 +2,8 @@
 // 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.parser;
+
 import 'dart:collection';
 import "dart:math" as math;
 
@@ -16,15 +18,22 @@ import 'package:analyzer/src/dart/error/syntactic_errors.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/error/codes.dart';
+import 'package:analyzer/src/fasta/ast_builder.dart';
+import 'package:analyzer/src/fasta/element_store.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisEngine;
 import 'package:analyzer/src/generated/java_core.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
+import 'package:front_end/src/fasta/kernel/kernel_builder.dart';
+import 'package:front_end/src/fasta/kernel/kernel_library_builder.dart';
+import 'package:front_end/src/fasta/parser/parser.dart' as fasta;
 
 export 'package:analyzer/src/dart/ast/utilities.dart' show ResolutionCopier;
 export 'package:analyzer/src/dart/error/syntactic_errors.dart';
 
+part 'parser_fasta.dart';
+
 /**
  * A simple data-holder for a method that needs to return multiple values.
  */
@@ -260,11 +269,26 @@ class Parser {
    */
   bool parseGenericMethodComments = false;
 
+  /**
+   * A flag indicating whether the analyzer [Parser] factory method
+   * will return a fasta based parser or an analyzer based parser.
+   */
+  static bool useFasta = const bool.fromEnvironment("useFastaParser");
+
   /**
    * Initialize a newly created parser to parse tokens in the given [_source]
    * and to report any errors that are found to the given [_errorListener].
    */
-  Parser(this._source, this._errorListener);
+  factory Parser(Source source, AnalysisErrorListener errorListener,
+      {bool useFasta}) {
+    if (useFasta ?? Parser.useFasta) {
+      return new _Parser2(source, errorListener);
+    } else {
+      return new Parser._(source, errorListener);
+    }
+  }
+
+  Parser._(this._source, this._errorListener);
 
   /**
    * Return the current token.

pkg/analyzer/lib/src/generated/parser_fasta.dart

@@ -0,0 +1,94 @@
+// Copyright (c) 2017, 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.
+
+part of analyzer.parser;
+
+class _Builder implements Builder {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+class _ElementStore implements ElementStore {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+class _KernelLibraryBuilder implements KernelLibraryBuilder {
+  @override
+  final uri;
+
+  _KernelLibraryBuilder(this.uri);
+
+  @override
+  Uri get fileUri => uri;
+
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+/**
+ * Replacement parser based on Fasta.
+ */
+class _Parser2 implements Parser {
+  @override
+  Token currentToken;
+
+  /**
+   * The builder which creates the analyzer AST data structures
+   * based on the Fasta parser.
+   */
+  final AstBuilder _astBuilder;
+
+  /**
+   * The error listener that will be informed of any errors that are found
+   * during the parse.
+   */
+  final AnalysisErrorListener _errorListener;
+
+  /**
+   * The fasta parser being wrapped.
+   */
+  final fasta.Parser _fastaParser;
+
+  /**
+   * The source being parsed.
+   */
+  final Source _source;
+
+  factory _Parser2(Source source, AnalysisErrorListener errorListener) {
+    var errorReporter = new ErrorReporter(errorListener, source);
+    var library = new _KernelLibraryBuilder(source.uri);
+    var member = new _Builder();
+    var elementStore = new _ElementStore();
+    var scope = new Scope.top(isModifiable: true);
+
+    AstBuilder astBuilder = new AstBuilder(
+        errorReporter, library, member, elementStore, scope, true);
+    fasta.Parser fastaParser = new fasta.Parser(astBuilder);
+    astBuilder.parser = fastaParser;
+    return new _Parser2._(source, errorListener, fastaParser, astBuilder);
+  }
+
+  _Parser2._(
+      this._source, this._errorListener, this._fastaParser, this._astBuilder);
+
+  @override
+  bool get parseGenericMethodComments => _astBuilder.parseGenericMethodComments;
+
+  @override
+  set parseGenericMethodComments(bool value) {
+    _astBuilder.parseGenericMethodComments = value;
+  }
+
+  @override
+  CompilationUnit parseCompilationUnit(Token token) {
+    currentToken = token;
+    return parseCompilationUnit2();
+  }
+
+  @override
+  CompilationUnit parseCompilationUnit2() {
+    currentToken = _fastaParser.parseUnit(currentToken);
+    return _astBuilder.pop();
+  }
+
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}

pkg/analyzer/test/generated/parser_fasta_test.dart

@@ -6,10 +6,12 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart' as analyzer;
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
+import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/fasta/ast_builder.dart';
 import 'package:analyzer/src/fasta/element_store.dart';
 import 'package:analyzer/src/generated/parser.dart' as analyzer;
 import 'package:analyzer/src/generated/utilities_dart.dart';
+import 'package:analyzer/src/string_source.dart';
 import 'package:front_end/src/fasta/kernel/kernel_builder.dart';
 import 'package:front_end/src/fasta/kernel/kernel_library_builder.dart';
 import 'package:front_end/src/fasta/parser/identifier_context.dart'
@@ -21,6 +23,7 @@ import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'parser_test.dart';
+import 'test_support.dart';
 
 main() {
   defineReflectiveSuite(() {
@@ -387,10 +390,23 @@ class FastaParserTestCase extends Object
   }
 
   @override
-  CompilationUnit parseCompilationUnit(String source,
-      [List<ErrorCode> errorCodes = const <ErrorCode>[]]) {
-    return _runParser(source, (parser) => parser.parseUnit, errorCodes)
-        as CompilationUnit;
+  CompilationUnit parseCompilationUnit(String content,
+      [List<ErrorCode> expectedErrorCodes = const <ErrorCode>[]]) {
+    // Scan tokens
+    var source = new StringSource(content, 'parser_test_StringSource.dart');
+    GatheringErrorListener listener = new GatheringErrorListener();
+    var scanner = new Scanner.fasta(source, listener);
+    scanner.scanGenericMethodComments = enableGenericMethodComments;
+    _fastaTokens = scanner.tokenize();
+
+    // Run parser
+    analyzer.Parser parser =
+        new analyzer.Parser(source, listener, useFasta: true);
+    CompilationUnit unit = parser.parseCompilationUnit(_fastaTokens);
+
+    // Assert and return result
+    listener.assertErrorsWithCodes(expectedErrorCodes);
+    return unit;
   }
 
   @override

pkg/front_end/lib/src/scanner/scanner.dart

@@ -126,7 +126,7 @@ class KeywordState {
  */
 abstract class Scanner {
   /**
-   * A flag indicating whether the [Scanner] factory method
+   * A flag indicating whether the analyzer [Scanner] factory method
    * will return a fasta based scanner or an analyzer based scanner.
    */
   static bool useFasta = const bool.fromEnvironment("useFastaScanner");