Non-pattern rewriting revisited

src/parsing/preparser.cc

Index: src/parsing/preparser.cc
diff --git a/src/parsing/preparser.cc b/src/parsing/preparser.cc
index f2559e4a8bbf9f98f22c8744cb2a9611aa3d8300..d335c8bdcd29433337d1173c9e17b3a1e116a999 100644
--- a/src/parsing/preparser.cc
+++ b/src/parsing/preparser.cc
@@ -573,7 +573,7 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
     int decl_pos = peek_position();
     PreParserExpression pattern = PreParserExpression::Default();
     {
-      ExpressionClassifier pattern_classifier;
+      ExpressionClassifier pattern_classifier(this);
       Token::Value next = peek();
       pattern = ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
 
@@ -594,7 +594,7 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
     Scanner::Location variable_loc = scanner()->location();
     nvars++;
     if (Check(Token::ASSIGN)) {
-      ExpressionClassifier classifier;
+      ExpressionClassifier classifier(this);
       ParseAssignmentExpression(var_context != kForStatement, &classifier,
                                 CHECK_OK);
       ValidateExpression(&classifier, CHECK_OK);
@@ -648,7 +648,7 @@ PreParser::Statement PreParser::ParseExpressionOrLabelledStatement(bool* ok) {
           IsClassConstructor(function_state_->kind())) {
         bool is_this = peek() == Token::THIS;
         Expression expr = Expression::Default();
-        ExpressionClassifier classifier;
+        ExpressionClassifier classifier(this);
         if (is_this) {
           expr = ParseStrongInitializationExpression(&classifier, CHECK_OK);
         } else {
@@ -684,7 +684,7 @@ PreParser::Statement PreParser::ParseExpressionOrLabelledStatement(bool* ok) {
   }
 
   bool starts_with_identifier = peek_any_identifier();
-  ExpressionClassifier classifier;
+  ExpressionClassifier classifier(this);
   Expression expr = ParseExpression(true, &classifier, CHECK_OK);
   ValidateExpression(&classifier, CHECK_OK);
 
@@ -937,10 +937,9 @@ PreParser::Statement PreParser::ParseForStatement(bool* ok) {
         }
 
         if (mode == ForEachStatement::ITERATE) {
-          ExpressionClassifier classifier;
-          Expression enumerable =
-              ParseAssignmentExpression(true, &classifier, CHECK_OK);
-          PreParserTraits::RewriteNonPattern(enumerable, &classifier, CHECK_OK);
+          ExpressionClassifier classifier(this);
+          ParseAssignmentExpression(true, &classifier, CHECK_OK);
+          RewriteNonPattern(&classifier, CHECK_OK);
         } else {
           ParseExpression(true, CHECK_OK);
         }
@@ -951,7 +950,7 @@ PreParser::Statement PreParser::ParseForStatement(bool* ok) {
       }
     } else {
       int lhs_beg_pos = peek_position();
-      ExpressionClassifier classifier;
+      ExpressionClassifier classifier(this);
       Expression lhs = ParseExpression(false, &classifier, CHECK_OK);
       int lhs_end_pos = scanner()->location().end_pos;
       is_let_identifier_expression =
@@ -976,10 +975,9 @@ PreParser::Statement PreParser::ParseForStatement(bool* ok) {
         }
 
         if (mode == ForEachStatement::ITERATE) {
-          ExpressionClassifier classifier;
-          Expression enumerable =
-              ParseAssignmentExpression(true, &classifier, CHECK_OK);
-          PreParserTraits::RewriteNonPattern(enumerable, &classifier, CHECK_OK);
+          ExpressionClassifier classifier(this);
+          ParseAssignmentExpression(true, &classifier, CHECK_OK);
+          RewriteNonPattern(&classifier, CHECK_OK);
         } else {
           ParseExpression(true, CHECK_OK);
         }
@@ -1057,7 +1055,7 @@ PreParser::Statement PreParser::ParseTryStatement(bool* ok) {
   if (tok == Token::CATCH) {
     Consume(Token::CATCH);
     Expect(Token::LPAREN, CHECK_OK);
-    ExpressionClassifier pattern_classifier;
+    ExpressionClassifier pattern_classifier(this);
     ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
     ValidateBindingPattern(&pattern_classifier, CHECK_OK);
     Expect(Token::RPAREN, CHECK_OK);
@@ -1114,7 +1112,7 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
   FunctionState function_state(&function_state_, &scope_, function_scope, kind,
                                &factory);
   DuplicateFinder duplicate_finder(scanner()->unicode_cache());
-  ExpressionClassifier formals_classifier(&duplicate_finder);
+  ExpressionClassifier formals_classifier(this, &duplicate_finder);
 
   Expect(Token::LPAREN, CHECK_OK);
   int start_position = scanner()->location().beg_pos;
@@ -1220,7 +1218,7 @@ PreParserExpression PreParser::ParseClassLiteral(
 
   bool has_extends = Check(Token::EXTENDS);
   if (has_extends) {
-    ExpressionClassifier classifier;
+    ExpressionClassifier classifier(this);
     ParseLeftHandSideExpression(&classifier, CHECK_OK);
     ValidateExpression(&classifier, CHECK_OK);
   }
@@ -1236,7 +1234,7 @@ PreParserExpression PreParser::ParseClassLiteral(
     bool is_computed_name = false;  // Classes do not care about computed
                                     // property names here.
     Identifier name;
-    ExpressionClassifier classifier;
+    ExpressionClassifier classifier(this);
     ParsePropertyDefinition(&checker, in_class, has_extends, is_static,
                             &is_computed_name, &has_seen_constructor,
                             &classifier, &name, CHECK_OK);
@@ -1260,7 +1258,7 @@ PreParser::Expression PreParser::ParseV8Intrinsic(bool* ok) {
   // Allow "eval" or "arguments" for backward compatibility.
   ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
   Scanner::Location spread_pos;
-  ExpressionClassifier classifier;
+  ExpressionClassifier classifier(this);
   ParseArguments(&spread_pos, &classifier, ok);
   ValidateExpression(&classifier, CHECK_OK);