Revert of Revert of [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 1192 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 1344 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 @@
     // that it will be compiled lazily.
 
     // To make this additional case work, both Parser and PreParser implement a
     // logic where only top-level functions will be parsed lazily.
     bool is_lazily_parsed = (mode() == PARSE_LAZILY &&
                              scope_->AllowsLazyCompilation() &&
                              !parenthesized_function_);
     parenthesized_function_ = false;  // The bit was set for this function only.
 
     if (is_lazily_parsed) {
-      SkipLazyFunctionBody(function_name, &materialized_literal_count,
+      SkipLazyFunctionBody(&materialized_literal_count,
                            &expected_property_count, CHECK_OK);
     } else {
       body = ParseEagerFunctionBody(function_name, pos, fvar, fvar_init_op,
                                     kind, CHECK_OK);
       materialized_literal_count = function_state.materialized_literal_count();
       expected_property_count = function_state.expected_property_count();
       handler_count = function_state.handler_count();
+
+      if (is_strong(language_mode()) && IsSubclassConstructor(kind)) {
+        if (!function_state.super_location().IsValid()) {
+          ReportMessageAt(function_name_location,
+                          "strong_super_call_missing", kReferenceError);
+          *ok = false;
+          return nullptr;
+        }
+      }
     }
 
     // Validate name and parameter names. We can do this only after parsing the
     // function, since the function can declare itself strict.
     CheckFunctionName(language_mode(), kind, function_name,
                       name_is_strict_reserved, function_name_location,
                       CHECK_OK);
     const bool use_strict_params = has_rest || IsConciseMethod(kind);
     CheckFunctionParameterNames(language_mode(), use_strict_params, error_locs,
                                 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()) {
-        ReportMessageAt(function_name_location, "strong_super_call_missing",
-                        kReferenceError);
-        *ok = false;
-        return nullptr;
-      }
-    }
   }
 
   FunctionLiteral::ParameterFlag duplicate_parameters =
       error_locs.duplicate.IsValid() ? FunctionLiteral::kHasDuplicateParameters
                                      : FunctionLiteral::kNoDuplicateParameters;
 
   FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
       function_name, ast_value_factory(), scope, body,
       materialized_literal_count, expected_property_count, handler_count,
       num_parameters, duplicate_parameters, function_type,
       FunctionLiteral::kIsFunction, parenthesized, kind, pos);
   function_literal->set_function_token_position(function_token_pos);
 
   if (scope->has_rest_parameter()) {
     // TODO(caitp): enable optimization of functions with rest params
     function_literal->set_dont_optimize_reason(kRestParameter);
   }
 
   if (fni_ != NULL && should_infer_name) fni_->AddFunction(function_literal);
   return function_literal;
 }
 
 
-void Parser::SkipLazyFunctionBody(const AstRawString* function_name,
-                                  int* materialized_literal_count,
+void Parser::SkipLazyFunctionBody(int* materialized_literal_count,
                                   int* expected_property_count,
                                   bool* ok) {
   if (produce_cached_parse_data()) CHECK(log_);
 
   int function_block_pos = position();
   if (consume_cached_parse_data() && !cached_parse_data_->rejected()) {
     // If we have cached data, we use it to skip parsing the function body. The
     // data contains the information we need to construct the lazy function.
     FunctionEntry entry =
         cached_parse_data_->GetFunctionEntry(function_block_pos);
@@ skipping 1672 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 v8::internal