Revert of Non-pattern rewriting revisited

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 555 matching lines @@
   // of a let declared variable is the scope of the immediately enclosing
   // block.
   int nvars = 0;  // the number of variables declared
   int bindings_start = peek_position();
   do {
     // Parse binding pattern.
     if (nvars > 0) Consume(Token::COMMA);
     int decl_pos = peek_position();
     PreParserExpression pattern = PreParserExpression::Default();
     {
-      ExpressionClassifier pattern_classifier(this);
+      ExpressionClassifier pattern_classifier;
       Token::Value next = peek();
       pattern = ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
 
       ValidateBindingPattern(&pattern_classifier, CHECK_OK);
       if (lexical) {
         ValidateLetPattern(&pattern_classifier, CHECK_OK);
       }
 
       if (!allow_harmony_destructuring_bind() && !pattern.IsIdentifier()) {
         ReportUnexpectedToken(next);
         *ok = false;
         return Statement::Default();
       }
     }
 
     is_pattern = pattern.IsObjectLiteral() || pattern.IsArrayLiteral();
 
     Scanner::Location variable_loc = scanner()->location();
     nvars++;
     if (Check(Token::ASSIGN)) {
-      ExpressionClassifier classifier(this);
+      ExpressionClassifier classifier;
       ParseAssignmentExpression(var_context != kForStatement, &classifier,
                                 CHECK_OK);
       ValidateExpression(&classifier, CHECK_OK);
 
       variable_loc.end_pos = scanner()->location().end_pos;
       if (first_initializer_loc && !first_initializer_loc->IsValid()) {
         *first_initializer_loc = variable_loc;
       }
     } else if ((require_initializer || is_pattern) &&
                (var_context != kForStatement || !PeekInOrOf())) {
@@ skipping 33 matching lines @@
       return Statement::Default();
 
     case Token::THIS:
       if (!FLAG_strong_this) break;
       // Fall through.
     case Token::SUPER:
       if (is_strong(language_mode()) &&
           IsClassConstructor(function_state_->kind())) {
         bool is_this = peek() == Token::THIS;
         Expression expr = Expression::Default();
-        ExpressionClassifier classifier(this);
+        ExpressionClassifier classifier;
         if (is_this) {
           expr = ParseStrongInitializationExpression(&classifier, CHECK_OK);
         } else {
           expr = ParseStrongSuperCallExpression(&classifier, CHECK_OK);
         }
         ValidateExpression(&classifier, CHECK_OK);
         switch (peek()) {
           case Token::SEMICOLON:
             Consume(Token::SEMICOLON);
             break;
@@ skipping 15 matching lines @@
       break;
 
     // TODO(arv): Handle `let [`
     // https://code.google.com/p/v8/issues/detail?id=3847
 
     default:
       break;
   }
 
   bool starts_with_identifier = peek_any_identifier();
-  ExpressionClassifier classifier(this);
+  ExpressionClassifier classifier;
   Expression expr = ParseExpression(true, &classifier, CHECK_OK);
   ValidateExpression(&classifier, CHECK_OK);
 
   // Even if the expression starts with an identifier, it is not necessarily an
   // identifier. For example, "foo + bar" starts with an identifier but is not
   // an identifier.
   if (starts_with_identifier && expr.IsIdentifier() && peek() == Token::COLON) {
     // Expression is a single identifier, and not, e.g., a parenthesized
     // identifier.
     DCHECK(!expr.AsIdentifier().IsFutureReserved());
@@ skipping 232 matching lines @@
             (is_strict(language_mode()) || mode == ForEachStatement::ITERATE ||
              is_lexical || is_binding_pattern)) {
           PreParserTraits::ReportMessageAt(
               first_initializer_loc, MessageTemplate::kForInOfLoopInitializer,
               ForEachStatement::VisitModeString(mode));
           *ok = false;
           return Statement::Default();
         }
 
         if (mode == ForEachStatement::ITERATE) {
-          ExpressionClassifier classifier(this);
-          ParseAssignmentExpression(true, &classifier, CHECK_OK);
-          RewriteNonPattern(&classifier, CHECK_OK);
+          ExpressionClassifier classifier;
+          Expression enumerable =
+              ParseAssignmentExpression(true, &classifier, CHECK_OK);
+          PreParserTraits::RewriteNonPattern(enumerable, &classifier, CHECK_OK);
         } else {
           ParseExpression(true, CHECK_OK);
         }
 
         Expect(Token::RPAREN, CHECK_OK);
         ParseSubStatement(CHECK_OK);
         return Statement::Default();
       }
     } else {
       int lhs_beg_pos = peek_position();
-      ExpressionClassifier classifier(this);
+      ExpressionClassifier classifier;
       Expression lhs = ParseExpression(false, &classifier, CHECK_OK);
       int lhs_end_pos = scanner()->location().end_pos;
       is_let_identifier_expression =
           lhs.IsIdentifier() && lhs.AsIdentifier().IsLet();
       bool is_for_each = CheckInOrOf(&mode, ok);
       if (!*ok) return Statement::Default();
       bool is_destructuring = is_for_each &&
                               allow_harmony_destructuring_assignment() &&
                               (lhs->IsArrayLiteral() || lhs->IsObjectLiteral());
 
       if (is_destructuring) {
         ValidateAssignmentPattern(&classifier, CHECK_OK);
       } else {
         ValidateExpression(&classifier, CHECK_OK);
       }
 
       if (is_for_each) {
         if (!is_destructuring) {
           lhs = CheckAndRewriteReferenceExpression(
               lhs, lhs_beg_pos, lhs_end_pos, MessageTemplate::kInvalidLhsInFor,
               kSyntaxError, CHECK_OK);
         }
 
         if (mode == ForEachStatement::ITERATE) {
-          ExpressionClassifier classifier(this);
-          ParseAssignmentExpression(true, &classifier, CHECK_OK);
-          RewriteNonPattern(&classifier, CHECK_OK);
+          ExpressionClassifier classifier;
+          Expression enumerable =
+              ParseAssignmentExpression(true, &classifier, CHECK_OK);
+          PreParserTraits::RewriteNonPattern(enumerable, &classifier, CHECK_OK);
         } else {
           ParseExpression(true, CHECK_OK);
         }
 
         Expect(Token::RPAREN, CHECK_OK);
         ParseSubStatement(CHECK_OK);
         return Statement::Default();
       }
     }
   }
@@ skipping 57 matching lines @@
 
   Token::Value tok = peek();
   if (tok != Token::CATCH && tok != Token::FINALLY) {
     ReportMessageAt(scanner()->location(), MessageTemplate::kNoCatchOrFinally);
     *ok = false;
     return Statement::Default();
   }
   if (tok == Token::CATCH) {
     Consume(Token::CATCH);
     Expect(Token::LPAREN, CHECK_OK);
-    ExpressionClassifier pattern_classifier(this);
+    ExpressionClassifier pattern_classifier;
     ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
     ValidateBindingPattern(&pattern_classifier, CHECK_OK);
     Expect(Token::RPAREN, CHECK_OK);
     {
       // TODO(adamk): Make this CATCH_SCOPE
       Scope* with_scope = NewScope(scope_, WITH_SCOPE);
       BlockState block_state(&scope_, with_scope);
       ParseBlock(CHECK_OK);
     }
     tok = peek();
@@ skipping 36 matching lines @@
   //   '(' FormalParameterList? ')' '{' FunctionBody '}'
 
   // Parse function body.
   bool outer_is_script_scope = scope_->is_script_scope();
   Scope* function_scope = NewScope(scope_, FUNCTION_SCOPE, kind);
   function_scope->SetLanguageMode(language_mode);
   PreParserFactory factory(NULL);
   FunctionState function_state(&function_state_, &scope_, function_scope, kind,
                                &factory);
   DuplicateFinder duplicate_finder(scanner()->unicode_cache());
-  ExpressionClassifier formals_classifier(this, &duplicate_finder);
+  ExpressionClassifier formals_classifier(&duplicate_finder);
 
   Expect(Token::LPAREN, CHECK_OK);
   int start_position = scanner()->location().beg_pos;
   function_scope->set_start_position(start_position);
   PreParserFormalParameters formals(function_scope);
   ParseFormalParameterList(&formals, &formals_classifier, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
   int formals_end_position = scanner()->location().end_pos;
 
   CheckArityRestrictions(formals.arity, kind, formals.has_rest, start_position,
@@ skipping 85 matching lines @@
 
   Scope* scope = NewScope(scope_, BLOCK_SCOPE);
   BlockState block_state(&scope_, scope);
   scope_->SetLanguageMode(
       static_cast<LanguageMode>(class_language_mode | STRICT));
   // TODO(marja): Make PreParser use scope names too.
   // scope_->SetScopeName(name);
 
   bool has_extends = Check(Token::EXTENDS);
   if (has_extends) {
-    ExpressionClassifier classifier(this);
+    ExpressionClassifier classifier;
     ParseLeftHandSideExpression(&classifier, CHECK_OK);
     ValidateExpression(&classifier, CHECK_OK);
   }
 
   ClassLiteralChecker checker(this);
   bool has_seen_constructor = false;
 
   Expect(Token::LBRACE, CHECK_OK);
   while (peek() != Token::RBRACE) {
     if (Check(Token::SEMICOLON)) continue;
     const bool in_class = true;
     const bool is_static = false;
     bool is_computed_name = false;  // Classes do not care about computed
                                     // property names here.
     Identifier name;
-    ExpressionClassifier classifier(this);
+    ExpressionClassifier classifier;
     ParsePropertyDefinition(&checker, in_class, has_extends, is_static,
                             &is_computed_name, &has_seen_constructor,
                             &classifier, &name, CHECK_OK);
     ValidateExpression(&classifier, CHECK_OK);
   }
 
   Expect(Token::RBRACE, CHECK_OK);
 
   return Expression::Default();
 }
 
 
 PreParser::Expression PreParser::ParseV8Intrinsic(bool* ok) {
   // CallRuntime ::
   //   '%' Identifier Arguments
   Expect(Token::MOD, CHECK_OK);
   if (!allow_natives()) {
     *ok = false;
     return Expression::Default();
   }
   // Allow "eval" or "arguments" for backward compatibility.
   ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
   Scanner::Location spread_pos;
-  ExpressionClassifier classifier(this);
+  ExpressionClassifier classifier;
   ParseArguments(&spread_pos, &classifier, ok);
   ValidateExpression(&classifier, CHECK_OK);
 
   DCHECK(!spread_pos.IsValid());
 
   return Expression::Default();
 }
 
 
 PreParserExpression PreParser::ParseDoExpression(bool* ok) {
@@ skipping 10 matching lines @@
     Expect(Token::RBRACE, CHECK_OK);
     return PreParserExpression::Default();
   }
 }
 
 #undef CHECK_OK
 
 
 }  // namespace internal
 }  // namespace v8