Widen --harmony-for-in flag to throw errors in PreParser

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 80 matching lines @@
 PreParserExpression PreParserTraits::ParseFunctionLiteral(
     PreParserIdentifier name, Scanner::Location function_name_location,
     FunctionNameValidity function_name_validity, FunctionKind kind,
     int function_token_position, FunctionLiteral::FunctionType type,
     LanguageMode language_mode, bool* ok) {
   return pre_parser_->ParseFunctionLiteral(
       name, function_name_location, function_name_validity, kind,
       function_token_position, type, language_mode, ok);
 }
 
-
 PreParser::PreParseResult PreParser::PreParseLazyFunction(
     LanguageMode language_mode, FunctionKind kind, bool has_simple_parameters,
-    ParserRecorder* log, Scanner::BookmarkScope* bookmark) {
+    ParserRecorder* log, Scanner::BookmarkScope* bookmark, int* use_counts) {
   log_ = log;
+  use_counts_ = use_counts;
   // Lazy functions always have trivial outer scopes (no with/catch scopes).
   Scope* top_scope = NewScope(scope_, SCRIPT_SCOPE);
   PreParserFactory top_factory(NULL);
   FunctionState top_state(&function_state_, &scope_, top_scope, kNormalFunction,
                           &top_factory);
   scope_->SetLanguageMode(language_mode);
   Scope* function_scope = NewScope(scope_, FUNCTION_SCOPE, kind);
   if (!has_simple_parameters) function_scope->SetHasNonSimpleParameters();
   PreParserFactory function_factory(NULL);
   FunctionState function_state(&function_state_, &scope_, function_scope, kind,
                                &function_factory);
   DCHECK_EQ(Token::LBRACE, scanner()->current_token());
   bool ok = true;
   int start_position = peek_position();
   ParseLazyFunctionLiteralBody(&ok, bookmark);
+  use_counts_ = nullptr;
   if (bookmark && bookmark->HasBeenReset()) {
     // Do nothing, as we've just aborted scanning this function.
   } else if (stack_overflow()) {
     return kPreParseStackOverflow;
   } else if (!ok) {
     ReportUnexpectedToken(scanner()->current_token());
   } else {
     DCHECK_EQ(Token::RBRACE, scanner()->peek());
     if (is_strict(scope_->language_mode())) {
       int end_pos = scanner()->location().end_pos;
@@ skipping 673 matching lines @@
         if (!*ok) return Statement::Default();
         if (decl_count != 1) {
           PreParserTraits::ReportMessageAt(
               bindings_loc, MessageTemplate::kForInOfLoopMultiBindings,
               ForEachStatement::VisitModeString(mode));
           *ok = false;
           return Statement::Default();
         }
         if (first_initializer_loc.IsValid() &&
             (is_strict(language_mode()) || mode == ForEachStatement::ITERATE ||
-             is_lexical || is_binding_pattern)) {
+             is_lexical || is_binding_pattern || allow_harmony_for_in())) {
+          // Only increment the use count if we would have let this through
+          // without the flag.
+          if (use_counts_ != nullptr && allow_harmony_for_in()) {
+            ++use_counts_[v8::Isolate::kForInInitializer];
+          }
           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);
@@ skipping 326 matching lines @@
   }
   Expect(Token::RBRACE, CHECK_OK);
   return PreParserExpression::Default();
 }
 
 #undef CHECK_OK
 
 
 }  // namespace internal
 }  // namespace v8