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

src/preparser.h

 // 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.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/bailout-reason.h"
 #include "src/expression-classifier.h"
 #include "src/func-name-inferrer.h"
@@ skipping 1630 matching lines @@
   static bool IsTaggedTemplate(const PreParserExpression tag) {
     return !tag.IsNoTemplateTag();
   }
 
   void AddFormalParameter(
       PreParserFormalParameters* parameters, PreParserExpression pattern,
       PreParserExpression initializer, bool is_rest) {
     ++parameters->arity;
   }
   void DeclareFormalParameter(Scope* scope, PreParserIdentifier parameter,
-                              bool is_simple,
-                              ExpressionClassifier* classifier) {}
+                              ExpressionClassifier* classifier) {
+    if (!classifier->is_simple_parameter_list()) {
+      scope->SetHasNonSimpleParameters();
+    }
+  }
 
   void CheckConflictingVarDeclarations(Scope* scope, bool* ok) {}
 
   // Temporary glue; these functions will move to ParserBase.
   PreParserExpression ParseV8Intrinsic(bool* ok);
   PreParserExpression ParseFunctionLiteral(
       PreParserIdentifier name, Scanner::Location function_name_location,
       FunctionNameValidity function_name_validity, FunctionKind kind,
       int function_token_position, FunctionLiteral::FunctionType type,
       FunctionLiteral::ArityRestriction arity_restriction,
@@ skipping 77 matching lines @@
 
   // Parses a single function literal, from the opening parentheses before
   // parameters to the closing brace after the body.
   // Returns a FunctionEntry describing the body of the function in enough
   // detail that it can be lazily compiled.
   // The scanner is expected to have matched the "function" or "function*"
   // keyword and parameters, and have consumed the initial '{'.
   // At return, unless an error occurred, the scanner is positioned before the
   // the final '}'.
   PreParseResult PreParseLazyFunction(
-      LanguageMode language_mode, FunctionKind kind, ParserRecorder* log,
-      Scanner::BookmarkScope* bookmark = nullptr);
+      LanguageMode language_mode, FunctionKind kind, bool has_simple_parameters,
+      ParserRecorder* log, Scanner::BookmarkScope* bookmark = nullptr);
 
  private:
   friend class PreParserTraits;
 
   static const int kLazyParseTrialLimit = 200;
 
   // These types form an algebra over syntactic categories that is just
   // rich enough to let us recognize and propagate the constructs that
   // are either being counted in the preparser data, or is important
   // to throw the correct syntax error exceptions.
@@ skipping 514 matching lines @@
                                               MessageTemplate::kUnexpectedToken,
                                               Token::String(Token::RPAREN));
         result = factory()->NewEmptyParentheses(beg_pos);
       } else if (allow_harmony_rest_parameters() && Check(Token::ELLIPSIS)) {
         // (...x)=>x.  The continuation that looks for the => is in
         // ParseAssignmentExpression.
         int ellipsis_pos = scanner()->location().beg_pos;
         classifier->RecordExpressionError(scanner()->location(),
                                           MessageTemplate::kUnexpectedToken,
                                           Token::String(Token::ELLIPSIS));
+        classifier->RecordNonSimpleParameter();
         Scanner::Location expr_loc = scanner()->peek_location();
         Token::Value tok = peek();
         result = this->ParseAssignmentExpression(true, classifier, CHECK_OK);
         // Patterns are not allowed as rest parameters.  There is no way we can
         // succeed so go ahead and use the convenient ReportUnexpectedToken
         // interface.
         if (!Traits::IsIdentifier(result)) {
           ReportUnexpectedTokenAt(expr_loc, tok);
           *ok = false;
           return this->EmptyExpression();
         }
         result = factory()->NewSpread(result, ellipsis_pos);
+
         if (peek() == Token::COMMA) {
           ReportMessageAt(scanner()->peek_location(),
                           MessageTemplate::kParamAfterRest);
           *ok = false;
           return this->EmptyExpression();
         }
         Expect(Token::RPAREN, CHECK_OK);
       } else {
         // Heuristically try to detect immediately called functions before
         // seeing the call parentheses.
@@ skipping 70 matching lines @@
     bool accept_IN, ExpressionClassifier* classifier, bool* ok) {
   // Expression ::
   //   AssignmentExpression
   //   Expression ',' AssignmentExpression
 
   ExpressionClassifier binding_classifier;
   ExpressionT result =
       this->ParseAssignmentExpression(accept_IN, &binding_classifier, CHECK_OK);
   classifier->Accumulate(binding_classifier,
                          ExpressionClassifier::AllProductions);
+  bool is_simple_parameter_list = this->IsIdentifier(result);
   bool seen_rest = false;
   while (peek() == Token::COMMA) {
     if (seen_rest) {
       // At this point the production can't possibly be valid, but we don't know
       // which error to signal.
       classifier->RecordArrowFormalParametersError(
           scanner()->peek_location(), MessageTemplate::kParamAfterRest);
     }
     Consume(Token::COMMA);
     bool is_rest = false;
     if (allow_harmony_rest_parameters() && peek() == Token::ELLIPSIS) {
       // 'x, y, ...z' in CoverParenthesizedExpressionAndArrowParameterList only
       // as the formal parameters of'(x, y, ...z) => foo', and is not itself a
       // valid expression or binding pattern.
       ExpressionUnexpectedToken(classifier);
       BindingPatternUnexpectedToken(classifier);
       Consume(Token::ELLIPSIS);
       seen_rest = is_rest = true;
     }
     int pos = position();
     ExpressionT right = this->ParseAssignmentExpression(
         accept_IN, &binding_classifier, CHECK_OK);
     if (is_rest) right = factory()->NewSpread(right, pos);
+    is_simple_parameter_list =
+        is_simple_parameter_list && this->IsIdentifier(right);
     classifier->Accumulate(binding_classifier,
                            ExpressionClassifier::AllProductions);
     result = factory()->NewBinaryOperation(Token::COMMA, result, right, pos);
   }
+  if (!is_simple_parameter_list || seen_rest) {
+    classifier->RecordNonSimpleParameter();
+  }
   return result;
 }
 
 
 template <class Traits>
 typename ParserBase<Traits>::ExpressionT ParserBase<Traits>::ParseArrayLiteral(
     ExpressionClassifier* classifier, bool* ok) {
   // ArrayLiteral ::
   //   '[' Expression? (',' Expression?)* ']'
 
@@ skipping 407 matching lines @@
 
   if (fni_ != NULL) fni_->Enter();
   ParserBase<Traits>::Checkpoint checkpoint(this);
   ExpressionClassifier arrow_formals_classifier(classifier->duplicate_finder());
   bool parenthesized_formals = peek() == Token::LPAREN;
   if (!parenthesized_formals) {
     ArrowFormalParametersUnexpectedToken(&arrow_formals_classifier);
   }
   ExpressionT expression = this->ParseConditionalExpression(
       accept_IN, &arrow_formals_classifier, CHECK_OK);
-
   if (allow_harmony_arrow_functions() && peek() == Token::ARROW) {
     BindingPatternUnexpectedToken(classifier);
     ValidateArrowFormalParameters(&arrow_formals_classifier, expression,
                                   parenthesized_formals, CHECK_OK);
     Scanner::Location loc(lhs_beg_pos, scanner()->location().end_pos);
     Scope* scope =
         this->NewScope(scope_, ARROW_SCOPE, FunctionKind::kArrowFunction);
+    bool is_simple = arrow_formals_classifier.is_simple_parameter_list();

[rossberg, 2015/08/24 13:11:08]

Nit: avoid the extra variable by storing to parameters.is_simple directly.

[conradw, 2015/08/25 11:31:20]

Done.

+    if (!is_simple) scope->SetHasNonSimpleParameters();
     FormalParametersT parameters(scope);
+    parameters.is_simple = is_simple;
     checkpoint.Restore(&parameters.materialized_literals_count);
 
     scope->set_start_position(lhs_beg_pos);
     Scanner::Location duplicate_loc = Scanner::Location::invalid();
     this->ParseArrowFunctionFormalParameterList(&parameters, expression, loc,
                                                 &duplicate_loc, CHECK_OK);
     if (duplicate_loc.IsValid()) {
       arrow_formals_classifier.RecordDuplicateFormalParameterError(
           duplicate_loc);
     }
@@ skipping 793 matching lines @@
   ValidateBindingPattern(classifier, ok);
   if (!*ok) return;
 
   if (!Traits::IsIdentifier(pattern)) {
     if (is_rest || !allow_harmony_destructuring()) {
       ReportUnexpectedToken(next);
       *ok = false;
       return;
     }
     parameters->is_simple = false;
+    classifier->RecordNonSimpleParameter();
   }
 
   ExpressionT initializer = Traits::EmptyExpression();
   if (!is_rest && allow_harmony_default_parameters() && Check(Token::ASSIGN)) {
     ExpressionClassifier init_classifier;
     initializer = ParseAssignmentExpression(true, &init_classifier, ok);
     if (!*ok) return;
     ValidateExpression(&init_classifier, ok);
     if (!*ok) return;
     parameters->is_simple = false;
+    classifier->RecordNonSimpleParameter();
   }
 
   Traits::AddFormalParameter(parameters, pattern, initializer, is_rest);
 }
 
 
 template <class Traits>
 void ParserBase<Traits>::ParseFormalParameterList(
     FormalParametersT* parameters, ExpressionClassifier* classifier, bool* ok) {
   // FormalParameters[Yield,GeneratorParameter] :
@@ skipping 20 matching lines @@
         return;
       }
       parameters->has_rest =
           allow_harmony_rest_parameters() && Check(Token::ELLIPSIS);
       ParseFormalParameter(parameters, classifier, ok);
       if (!*ok) return;
     } while (!parameters->has_rest && Check(Token::COMMA));
 
     if (parameters->has_rest) {
       parameters->is_simple = false;
+      classifier->RecordNonSimpleParameter();
       if (peek() == Token::COMMA) {
         ReportMessageAt(scanner()->peek_location(),
                       MessageTemplate::kParamAfterRest);
         *ok = false;
         return;
       }
     }
   }
 
   for (int i = 0; i < parameters->Arity(); ++i) {
     auto parameter = parameters->at(i);
-    Traits::DeclareFormalParameter(
-        parameters->scope, parameter, parameters->is_simple, classifier);
+    Traits::DeclareFormalParameter(parameters->scope, parameter, classifier);
   }
 }
 
 
 template <class Traits>
 void ParserBase<Traits>::CheckArityRestrictions(
     int param_count, FunctionLiteral::ArityRestriction arity_restriction,
     bool has_rest, int formals_start_pos, int formals_end_pos, bool* ok) {
   switch (arity_restriction) {
     case FunctionLiteral::GETTER_ARITY:
@@ skipping 322 matching lines @@
       *ok = false;
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H