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

src/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 84 matching lines @@
     int function_token_position, FunctionLiteral::FunctionType type,
     FunctionLiteral::ArityRestriction arity_restriction,
     LanguageMode language_mode, bool* ok) {
   return pre_parser_->ParseFunctionLiteral(
       name, function_name_location, function_name_validity, kind,
       function_token_position, type, arity_restriction, language_mode, ok);
 }
 
 
 PreParser::PreParseResult PreParser::PreParseLazyFunction(
-    LanguageMode language_mode, FunctionKind kind, ParserRecorder* log,
-    Scanner::BookmarkScope* bookmark) {
+    LanguageMode language_mode, FunctionKind kind, bool has_simple_parameters,
+    ParserRecorder* log, Scanner::BookmarkScope* bookmark) {
   log_ = log;
   // 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_, IsArrowFunction(kind) ? ARROW_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);
   if (bookmark && bookmark->HasBeenReset()) {
     ;  // Do nothing, as we've just aborted scanning this function.
   } else if (stack_overflow()) {
@@ skipping 118 matching lines @@
       }
       if (super_loc.beg_pos != old_super_loc.beg_pos &&
           super_loc.beg_pos != token_loc.beg_pos) {
         ReportMessageAt(super_loc, MessageTemplate::kStrongConstructorSuper);
         *ok = false;
         return;
       }
     }
 
     if (directive_prologue) {
-      if (statement.IsUseStrictLiteral()) {
+      bool use_strict_found = statement.IsUseStrictLiteral();
+      bool use_strong_found =
+          statement.IsUseStrongLiteral() && allow_strong_mode();
+
+      if (use_strict_found) {
         scope_->SetLanguageMode(
             static_cast<LanguageMode>(scope_->language_mode() | STRICT));
-      } else if (statement.IsUseStrongLiteral() && allow_strong_mode()) {
+      } else if (use_strong_found) {
         scope_->SetLanguageMode(static_cast<LanguageMode>(
             scope_->language_mode() | STRONG));
       } else if (!statement.IsStringLiteral()) {
         directive_prologue = false;
       }
+
+      if ((use_strict_found || use_strong_found) &&
+          !scope_->HasSimpleParameters()) {
+        // TC39 deemed "use strict" directives to be an error when occurring
+        // in the body of a function with non-simple parameter list, on
+        // 29/7/2015. https://goo.gl/ueA7Ln
+        //
+        // In V8, this also applies to "use strong " directives.
+        PreParserTraits::ReportMessageAt(
+            token_loc, MessageTemplate::kIllegalLanguageModeDirective,
+            use_strict_found ? "use strict" : "use strong");
+        *ok = false;
+        return;
+      }
     }
 
     // If we're allowed to reset to a bookmark, we will do so when we see a long
     // and trivial function.
     // Our current definition of 'long and trivial' is:
     // - over 200 statements
     // - all starting with an identifier (i.e., no if, for, while, etc.)
     if (maybe_reset && (!starts_with_identifier ||
                         ++count_statements > kLazyParseTrialLimit)) {
       if (count_statements > kLazyParseTrialLimit) {
@@ skipping 777 matching lines @@
   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(&duplicate_finder);
 
   Expect(Token::LPAREN, CHECK_OK);
   int start_position = scanner()->location().beg_pos;
   function_scope->set_start_position(start_position);
-  PreParserFormalParameters formals(nullptr);
+  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, arity_restriction,
                          formals.has_rest, start_position,
                          formals_end_position, CHECK_OK);
 
   // See Parser::ParseFunctionLiteral for more information about lazy parsing
   // and lazy compilation.
@@ skipping 133 matching lines @@
 
   DCHECK(!spread_pos.IsValid());
 
   return Expression::Default();
 }
 
 #undef CHECK_OK
 
 
 } }  // v8::internal