[parser] Refactor of (Parse|Desugar)*(Async|Arrow)*

src/parsing/preparser.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <cmath>
 
 #include "src/allocation.h"
 #include "src/base/logging.h"
 #include "src/conversions-inl.h"
 #include "src/conversions.h"
@@ skipping 117 matching lines @@
 
 // The PreParser checks that the syntax follows the grammar for JavaScript,
 // and collects some information about the program along the way.
 // The grammar check is only performed in order to understand the program
 // sufficiently to deduce some information about it, that can be used
 // to speed up later parsing. Finding errors is not the goal of pre-parsing,
 // rather it is to speed up properly written and correct programs.
 // That means that contextual checks (like a label being declared where
 // it is used) are generally omitted.
 
-PreParser::Statement PreParser::ParseAsyncFunctionDeclaration(
-    ZoneList<const AstRawString*>* names, bool default_export, bool* ok) {
-  // AsyncFunctionDeclaration ::
-  //   async [no LineTerminator here] function BindingIdentifier[Await]
-  //       ( FormalParameters[Await] ) { AsyncFunctionBody }
-  DCHECK_EQ(scanner()->current_token(), Token::ASYNC);
-  int pos = position();
-  Expect(Token::FUNCTION, CHECK_OK);
-  ParseFunctionFlags flags = ParseFunctionFlags::kIsAsync;
-  return ParseHoistableDeclaration(pos, flags, names, default_export, ok);
-}
-
 PreParser::Statement PreParser::ParseClassDeclaration(
     ZoneList<const AstRawString*>* names, bool default_export, bool* ok) {
   int pos = position();
   bool is_strict_reserved = false;
   Identifier name =
       ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
   ExpressionClassifier no_classifier(this);
   ParseClassLiteral(name, scanner()->location(), is_strict_reserved, pos,
                     CHECK_OK);
   return Statement::Default();
@@ skipping 76 matching lines @@
 
   if (is_strict(language_mode)) {
     int end_position = scanner()->location().end_pos;
     CheckStrictOctalLiteral(start_position, end_position, CHECK_OK);
     CheckDecimalLiteralWithLeadingZero(start_position, end_position);
   }
 
   return Expression::Default();
 }
 
-PreParser::Expression PreParser::ParseAsyncFunctionExpression(bool* ok) {
-  // AsyncFunctionDeclaration ::
-  //   async [no LineTerminator here] function ( FormalParameters[Await] )
-  //       { AsyncFunctionBody }
-  //
-  //   async [no LineTerminator here] function BindingIdentifier[Await]
-  //       ( FormalParameters[Await] ) { AsyncFunctionBody }
-  int pos = position();
-  Expect(Token::FUNCTION, CHECK_OK);
-  bool is_strict_reserved = false;
-  Identifier name;
-  FunctionLiteral::FunctionType type = FunctionLiteral::kAnonymousExpression;
-
-  if (peek_any_identifier()) {
-    type = FunctionLiteral::kNamedExpression;
-    name = ParseIdentifierOrStrictReservedWord(FunctionKind::kAsyncFunction,
-                                               &is_strict_reserved, CHECK_OK);
-  }
-
-  ParseFunctionLiteral(name, scanner()->location(),
-                       is_strict_reserved ? kFunctionNameIsStrictReserved
-                                          : kFunctionNameValidityUnknown,
-                       FunctionKind::kAsyncFunction, pos, type, language_mode(),
-                       CHECK_OK);
-  return Expression::Default();
-}
-
 PreParser::LazyParsingResult PreParser::ParseLazyFunctionLiteralBody(
     bool may_abort, bool* ok) {
   int body_start = position();
   PreParserStatementList body;
   LazyParsingResult result = ParseStatementList(
       body, Token::RBRACE, may_abort, CHECK_OK_VALUE(kLazyParsingComplete));
   if (result == kLazyParsingAborted) return result;
 
   // Position right after terminal '}'.
   DCHECK_EQ(Token::RBRACE, scanner()->peek());
@@ skipping 52 matching lines @@
                                  &has_seen_constructor, CHECK_OK);
     ValidateExpression(CHECK_OK);
     impl()->AccumulateFormalParameterContainmentErrors();
   }
 
   Expect(Token::RBRACE, CHECK_OK);
 
   return Expression::Default();
 }
 
-void PreParser::ParseAsyncArrowSingleExpressionBody(PreParserStatementList body,
-                                                    bool accept_IN, int pos,
-                                                    bool* ok) {
-  scope()->ForceContextAllocation();
-
-  PreParserExpression return_value =
-      ParseAssignmentExpression(accept_IN, CHECK_OK_VOID);
-
-  body->Add(PreParserStatement::ExpressionStatement(return_value), zone());
-}
-
 PreParserExpression PreParser::ExpressionFromIdentifier(
     PreParserIdentifier name, int start_position, int end_position,
     InferName infer) {
   if (track_unresolved_variables_) {
     AstNodeFactory factory(ast_value_factory());
     // Setting the Zone is necessary because zone_ might be the temp Zone, and
     // AstValueFactory doesn't know about it.
     factory.set_zone(zone());
     DCHECK_NOT_NULL(name.string_);
     scope()->NewUnresolved(&factory, name.string_, start_position, end_position,
                            NORMAL_VARIABLE);
   }
   return PreParserExpression::FromIdentifier(name);
 }
 
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM
 
 
 }  // namespace internal
 }  // namespace v8