[parser] disallow language mode directive in body of function with non-simple parameters

src/parser.cc

 // Copyright 2012 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 "src/parser.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/ast-literal-reindexer.h"
 #include "src/bailout-reason.h"
@@ skipping 1183 matching lines @@
         // scope for formal parameter parsing.
         BlockState block_state(&scope_, scope);
         if (Check(Token::LPAREN)) {
           // '(' StrictFormalParameters ')'
           ParseFormalParameterList(&formals, &formals_classifier, &ok);
           if (ok) ok = Check(Token::RPAREN);
         } else {
           // BindingIdentifier
           ParseFormalParameter(&formals, &formals_classifier, &ok);
           if (ok) {
-            DeclareFormalParameter(
-                formals.scope, formals.at(0), formals.is_simple,
-                &formals_classifier);
+            DeclareFormalParameter(formals.scope, formals.at(0),
+                                   &formals_classifier);
           }
         }
       }
 
       if (ok) {
         checkpoint.Restore(&formals.materialized_literals_count);
         Expression* expression =
             ParseArrowFunctionLiteral(formals, formals_classifier, &ok);
         if (ok) {
           // Scanning must end at the same position that was recorded
@@ skipping 101 matching lines @@
                 ast_value_factory()->use_strict_string() &&
             token_loc.end_pos - token_loc.beg_pos ==
                 ast_value_factory()->use_strict_string()->length() + 2;
         bool use_strong_found =
             allow_strong_mode() &&
             literal->raw_value()->AsString() ==
                 ast_value_factory()->use_strong_string() &&
             token_loc.end_pos - token_loc.beg_pos ==
                 ast_value_factory()->use_strong_string()->length() + 2;
         if (use_strict_found || use_strong_found) {
+          if (!scope_->HasSimpleParameters()) {
+            // A block declaration scope as a child scope of a function scope
+            // indicates that a function has a non-simple parameter list.
+            // TC39 deemed "use strict" directives to be an error in this case,
+            // on 29/7/2015. https://goo.gl/ueA7Ln
+            //
+            // In V8, this also applies to "use strong " directives.
+            const AstRawString* string = literal->raw_value()->AsString();
+            ParserTraits::ReportMessageAt(
+                token_loc, MessageTemplate::kIllegalLanguageModeDirective,
+                string);
+            *ok = false;
+            return nullptr;
+          }
+
           // Strong mode implies strict mode. If there are several "use strict"
           // / "use strong" directives, do the strict mode changes only once.
           if (is_sloppy(scope_->language_mode())) {
             scope_->SetLanguageMode(static_cast<LanguageMode>(
                 scope_->language_mode() | STRICT));
           }
 
           if (use_strong_found) {
             scope_->SetLanguageMode(static_cast<LanguageMode>(
                 scope_->language_mode() | STRONG));
@@ skipping 2513 matching lines @@
 }
 
 
 Handle<FixedArray> CompileTimeValue::GetElements(Handle<FixedArray> value) {
   return Handle<FixedArray>(FixedArray::cast(value->get(kElementsSlot)));
 }
 
 
 void ParserTraits::ParseArrowFunctionFormalParameters(
     ParserFormalParameters* parameters, Expression* expr,
-    const Scanner::Location& params_loc,
-    Scanner::Location* duplicate_loc, bool* ok) {
+    const Scanner::Location& params_loc, bool* ok) {
   if (parameters->Arity() >= Code::kMaxArguments) {
     ReportMessageAt(params_loc, MessageTemplate::kMalformedArrowFunParamList);
     *ok = false;
     return;
   }
 
   // ArrowFunctionFormals ::
   //    Binary(Token::COMMA, NonTailArrowFunctionFormals, Tail)
   //    Tail
   // NonTailArrowFunctionFormals ::
   //    Binary(Token::COMMA, NonTailArrowFunctionFormals, VariableProxy)
   //    VariableProxy
   // Tail ::
   //    VariableProxy
   //    Spread(VariableProxy)
   //
   // As we need to visit the parameters in left-to-right order, we recurse on
   // the left-hand side of comma expressions.
   //
   if (expr->IsBinaryOperation()) {
     BinaryOperation* binop = expr->AsBinaryOperation();
     // The classifier has already run, so we know that the expression is a valid
     // arrow function formals production.
     DCHECK_EQ(binop->op(), Token::COMMA);
     Expression* left = binop->left();
     Expression* right = binop->right();
-    ParseArrowFunctionFormalParameters(parameters, left, params_loc,
-                                       duplicate_loc, ok);
+    ParseArrowFunctionFormalParameters(parameters, left, params_loc, ok);
     if (!*ok) return;
     // LHS of comma expression should be unparenthesized.
     expr = right;
   }
 
   // Only the right-most expression may be a rest parameter.
   DCHECK(!parameters->has_rest);
 
   bool is_rest = expr->IsSpread();
   if (is_rest) {
@@ skipping 28 matching lines @@
   AddFormalParameter(parameters, expr, initializer, is_rest);
 }
 
 
 void ParserTraits::ParseArrowFunctionFormalParameterList(
     ParserFormalParameters* parameters, Expression* expr,
     const Scanner::Location& params_loc,
     Scanner::Location* duplicate_loc, bool* ok) {
   if (expr->IsEmptyParentheses()) return;
 
-  ParseArrowFunctionFormalParameters(parameters, expr, params_loc,
-                                     duplicate_loc, ok);
+  ParseArrowFunctionFormalParameters(parameters, expr, params_loc, ok);
   if (!*ok) return;
 
+  ExpressionClassifier classifier;
+  if (!parameters->is_simple) {
+    classifier.RecordNonSimpleParameter();
+  }
   for (int i = 0; i < parameters->Arity(); ++i) {
     auto parameter = parameters->at(i);
-    ExpressionClassifier classifier;
-    DeclareFormalParameter(
-        parameters->scope, parameter, parameters->is_simple, &classifier);
+    DeclareFormalParameter(parameters->scope, parameter, &classifier);
     if (!duplicate_loc->IsValid()) {
       *duplicate_loc = classifier.duplicate_formal_parameter_error().location;
     }
   }
   DCHECK_EQ(parameters->is_simple, parameters->scope->has_simple_parameters());
 }
 
 
 void ParserTraits::ReindexLiterals(const ParserFormalParameters& parameters) {
   if (parser_->function_state_->materialized_literal_count() > 0) {
@@ skipping 598 matching lines @@
     SET_ALLOW(harmony_rest_parameters);
     SET_ALLOW(harmony_default_parameters);
     SET_ALLOW(harmony_spreadcalls);
     SET_ALLOW(harmony_destructuring);
     SET_ALLOW(harmony_spread_arrays);
     SET_ALLOW(harmony_new_target);
     SET_ALLOW(strong_mode);
 #undef SET_ALLOW
   }
   PreParser::PreParseResult result = reusable_preparser_->PreParseLazyFunction(
-      language_mode(), function_state_->kind(), logger, bookmark);
+      language_mode(), function_state_->kind(), scope_->has_simple_parameters(),
+      logger, bookmark);
   if (pre_parse_timer_ != NULL) {
     pre_parse_timer_->Stop();
   }
   return result;
 }
 
 
 ClassLiteral* Parser::ParseClassLiteral(const AstRawString* name,
                                         Scanner::Location class_name_location,
                                         bool name_is_strict_reserved, int pos,
@@ skipping 1496 matching lines @@
 Expression* Parser::SpreadCallNew(Expression* function,
                                   ZoneList<v8::internal::Expression*>* args,
                                   int pos) {
   args->InsertAt(0, function, zone());
 
   return factory()->NewCallRuntime(
       ast_value_factory()->reflect_construct_string(), NULL, args, pos);
 }
 }  // namespace internal
 }  // namespace v8