[strong] checking of this & super in constructors

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/v8.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
@@ skipping 1190 matching lines @@
   TargetScope scope(&this->target_stack_);
 
   DCHECK(body != NULL);
   bool directive_prologue = true;     // Parsing directive prologue.
 
   while (peek() != end_token) {
     if (directive_prologue && peek() != Token::STRING) {
       directive_prologue = false;
     }
 
-    Token::Value token = peek();
     Scanner::Location token_loc = scanner()->peek_location();
-    Scanner::Location old_super_loc = function_state_->super_call_location();
+    Scanner::Location old_this_loc = function_state_->this_location();
+    Scanner::Location old_super_loc = function_state_->super_location();
     Statement* stat = ParseStatementListItem(CHECK_OK);
-    Scanner::Location super_loc = function_state_->super_call_location();
 
     if (is_strong(language_mode()) &&
-        i::IsConstructor(function_state_->kind()) &&
-        !old_super_loc.IsValid() && super_loc.IsValid() &&
-        token != Token::SUPER) {
-      // TODO(rossberg): This is more permissive than spec'ed, it allows e.g.
-      //   super(), 1;
-      //   super() + "";
-      //   super() = 0;
-      // That should still be safe, though, thanks to left-to-right evaluation.
-      // The proper check would be difficult to implement in the preparser.
-      ReportMessageAt(super_loc, "strong_super_call_nested");
-      *ok = false;
-      return NULL;
+        scope_->is_function_scope() &&
+        i::IsConstructor(function_state_->kind())) {
+      Scanner::Location this_loc = function_state_->this_location();
+      Scanner::Location super_loc = function_state_->super_location();
+      if (this_loc.beg_pos != old_this_loc.beg_pos &&
+          this_loc.beg_pos != token_loc.beg_pos) {
+        ReportMessageAt(this_loc, "strong_constructor_this");
+        *ok = false;
+        return nullptr;
+      }
+      if (super_loc.beg_pos != old_super_loc.beg_pos &&
+          super_loc.beg_pos != token_loc.beg_pos) {
+        ReportMessageAt(super_loc, "strong_constructor_super");
+        *ok = false;
+        return nullptr;
+      }
     }
 
     if (stat == NULL || stat->IsEmpty()) {
       directive_prologue = false;   // End of directive prologue.
       continue;
     }
 
     if (directive_prologue) {
       // A shot at a directive.
       ExpressionStatement* e_stat;
@@ skipping 1304 matching lines @@
 
 Statement* Parser::ParseExpressionOrLabelledStatement(
     ZoneList<const AstRawString*>* labels, bool* ok) {
   // ExpressionStatement | LabelledStatement ::
   //   Expression ';'
   //   Identifier ':' Statement
   //
   // ExpressionStatement[Yield] :
   //   [lookahead ∉ {{, function, class, let [}] Expression[In, ?Yield] ;
 
+  int pos = peek_position();
+
   switch (peek()) {
     case Token::FUNCTION:
     case Token::LBRACE:
       UNREACHABLE();  // Always handled by the callers.
     case Token::CLASS:
       ReportUnexpectedToken(Next());
       *ok = false;
       return nullptr;
 
+    case Token::THIS:
+    case Token::SUPER:
+      if (is_strong(language_mode()) &&
+          i::IsConstructor(function_state_->kind())) {
+        bool is_this = peek() == Token::THIS;
+        Expression* expr;
+        if (is_this) {
+          expr = ParseStrongInitializationExpression(CHECK_OK);
+        } else {
+          expr = ParseStrongSuperCallExpression(CHECK_OK);
+        }
+        switch (peek()) {
+          case Token::SEMICOLON:
+            Consume(Token::SEMICOLON);
+            break;
+          case Token::RBRACE:
+          case Token::EOS:
+            break;
+          default:
+            if (!scanner()->HasAnyLineTerminatorBeforeNext()) {
+              ReportMessageAt(function_state_->this_location(),
+                              is_this ? "strong_constructor_this"
+                                      : "strong_constructor_super");
+              *ok = false;
+              return nullptr;
+            }
+        }
+        return factory()->NewExpressionStatement(expr, pos);
+      }
+      break;
+
     // TODO(arv): Handle `let [`
     // https://code.google.com/p/v8/issues/detail?id=3847
 
     default:
       break;
   }
 
-  int pos = peek_position();
   bool starts_with_idenfifier = peek_any_identifier();
   Expression* expr = ParseExpression(true, CHECK_OK);
   if (peek() == Token::COLON && starts_with_idenfifier && expr != NULL &&
       expr->AsVariableProxy() != NULL &&
       !expr->AsVariableProxy()->is_this()) {
     // Expression is a single identifier, and not, e.g., a parenthesized
     // identifier.
     VariableProxy* var = expr->AsVariableProxy();
     const AstRawString* label = var->raw_name();
     // TODO(1240780): We don't check for redeclaration of labels
@@ skipping 1373 matching lines @@
                                 reserved_error_loc, CHECK_OK);
 
     if (is_strict(language_mode())) {
       CheckStrictOctalLiteral(scope->start_position(), scope->end_position(),
                               CHECK_OK);
     }
     if (is_strict(language_mode())) {
       CheckConflictingVarDeclarations(scope, CHECK_OK);
     }
     if (is_strong(language_mode()) && IsSubclassConstructor(kind)) {
-      if (!function_state.super_call_location().IsValid()) {
+      if (!function_state.super_location().IsValid()) {
         ReportMessageAt(function_name_location, "strong_super_call_missing",
                         kReferenceError);
         *ok = false;
         return nullptr;
       }
     }
   }
 
   FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
       function_name, ast_value_factory(), scope, body,
@@ skipping 1585 matching lines @@
     } else {
       const uc16* data = reinterpret_cast<const uc16*>(raw_string->raw_data());
       running_hash = StringHasher::ComputeRunningHash(running_hash, data,
                                                       raw_string->length());
     }
   }
 
   return running_hash;
 }
 } }  // namespace v8::internal