Use ExpressionClassifier for bindings.

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 1127 matching lines @@
         if (ok) ok = Check(Token::RPAREN);
       } else {
         // BindingIdentifier
         ParseFormalParameter(scope, &error_locs, has_rest, &ok);
       }
 
       if (ok) {
         ExpressionClassifier classifier;
         Expression* expression = ParseArrowFunctionLiteral(
             scope, error_locs, has_rest, &classifier, &ok);
-        // TODO(dslomov): report error if not a valid expression.
+        ValidateExpression(&classifier, &ok);
         if (ok) {
           // Scanning must end at the same position that was recorded
           // previously. If not, parsing has been interrupted due to a stack
           // overflow, at which point the partially parsed arrow function
           // concise body happens to be a valid expression. This is a problem
           // only for arrow functions with single expression bodies, since there
           // is no end token such as "}" for normal functions.
           if (scanner()->location().end_pos == shared_info->end_position()) {
             // The pre-parser saw an arrow function here, so the full parser
             // must produce a FunctionLiteral.
@@ skipping 441 matching lines @@
 
     case Token::CLASS:
       // TODO(ES6): Support parsing anonymous class declarations here.
       result = ParseClassDeclaration(&names, CHECK_OK);
       break;
 
     default: {
       int pos = peek_position();
       ExpressionClassifier classifier;
       Expression* expr = ParseAssignmentExpression(true, &classifier, CHECK_OK);
-      // TODO(dslomov): report error if not a valid expression.
+      ValidateExpression(&classifier, CHECK_OK);
 
       ExpectSemicolon(CHECK_OK);
       result = factory()->NewExpressionStatement(expr, pos);
       break;
     }
   }
 
   const AstRawString* default_string = ast_value_factory()->default_string();
 
   DCHECK_LE(names.length(), 1);
@@ skipping 735 matching lines @@
   int nvars = 0;  // the number of variables declared
   int bindings_start = peek_position();
   const AstRawString* name = NULL;
   const AstRawString* first_name = NULL;
   bool is_for_iteration_variable;
   do {
     if (fni_ != NULL) fni_->Enter();
 
     // Parse variable name.
     if (nvars > 0) Consume(Token::COMMA);
-    name = ParseIdentifier(kDontAllowRestrictedIdentifiers, CHECK_OK);
+
+    {
+      ExpressionClassifier pattern_classifier;
+      Token::Value next = peek();
+      Expression* pattern =
+          ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
+      ValidateBindingPattern(&pattern_classifier, CHECK_OK);
+      if (pattern->IsVariableProxy() &&
+          pattern->AsVariableProxy()->IsValidReferenceExpression()) {
+        scope_->RemoveUnresolved(pattern->AsVariableProxy());

[Dmitry Lomov (no reviews), 2015/04/23 16:29:24]

Here, instead of adding an unresolved proxy and then removing it, I can
propagate the information that a binding pattern is expected through the
ExpressionClassifier.

[arv (Not doing code reviews), 2015/04/23 16:52:52]

I like this better. I doubt it matters for performance.

+        name = pattern->AsVariableProxy()->raw_name();
+      } else {
+        ReportUnexpectedToken(next);
+        *ok = false;
+        return nullptr;
+      }
+    }
+
     if (!first_name) first_name = name;
     Scanner::Location variable_loc = scanner()->location();
     if (fni_ != NULL) fni_->PushVariableName(name);
 
     // Declare variable.
     // Note that we *always* must treat the initial value via a separate init
     // assignment for variables and constants because the value must be assigned
     // when the variable is encountered in the source. But the variable/constant
     // is declared (and set to 'undefined') upon entering the function within
     // which the variable or constant is declared. Only function variables have
@@ skipping 58 matching lines @@
     Expression* value = NULL;
     int pos = -1;
     // Harmony consts have non-optional initializers.
     if (peek() == Token::ASSIGN ||
         (mode == CONST && !is_for_iteration_variable)) {
       Expect(Token::ASSIGN, CHECK_OK);
       pos = position();
       ExpressionClassifier classifier;
       value = ParseAssignmentExpression(var_context != kForStatement,
                                         &classifier, CHECK_OK);
-      // TODO(dslomov): check that expression is valid.
+      ValidateExpression(&classifier, CHECK_OK);
       variable_loc.end_pos = scanner()->location().end_pos;
 
       if (first_initializer_loc && !first_initializer_loc->IsValid()) {
         *first_initializer_loc = variable_loc;
       }
 
       // Don't infer if it is "a = function(){...}();"-like expression.
       if (fni_ != NULL &&
           value->AsCall() == NULL &&
           value->AsCallNew() == NULL) {
@@ skipping 170 matching lines @@
       if (is_strong(language_mode()) &&
           i::IsConstructor(function_state_->kind())) {
         bool is_this = peek() == Token::THIS;
         Expression* expr;
         ExpressionClassifier classifier;
         if (is_this) {
           expr = ParseStrongInitializationExpression(&classifier, CHECK_OK);
         } else {
           expr = ParseStrongSuperCallExpression(&classifier, CHECK_OK);
         }
-        // TODO(dslomov): report error if not a valid expression.
+        ValidateExpression(&classifier, 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(),
@@ skipping 1708 matching lines @@
         proxy, CONST, block_scope, pos, is_class_declaration,
         scope_->class_declaration_group_start());
     Declare(declaration, true, CHECK_OK);
   }
 
   Expression* extends = NULL;
   if (Check(Token::EXTENDS)) {
     block_scope->set_start_position(scanner()->location().end_pos);
     ExpressionClassifier classifier;
     extends = ParseLeftHandSideExpression(&classifier, CHECK_OK);
-    // TODO(dslomov): report error if not a valid expression.
+    ValidateExpression(&classifier, CHECK_OK);
   } else {
     block_scope->set_start_position(scanner()->location().end_pos);
   }
 
 
   ClassLiteralChecker checker(this);
   ZoneList<ObjectLiteral::Property*>* properties = NewPropertyList(4, zone());
   FunctionLiteral* constructor = NULL;
   bool has_seen_constructor = false;
 
   Expect(Token::LBRACE, CHECK_OK);
 
   const bool has_extends = extends != nullptr;
   while (peek() != Token::RBRACE) {
     if (Check(Token::SEMICOLON)) continue;
     if (fni_ != NULL) fni_->Enter();
     const bool in_class = true;
     const bool is_static = false;
     bool is_computed_name = false;  // Classes do not care about computed
                                     // property names here.
     ExpressionClassifier classifier;
     ObjectLiteral::Property* property = ParsePropertyDefinition(
         &checker, in_class, has_extends, is_static, &is_computed_name,
         &has_seen_constructor, &classifier, CHECK_OK);
-    // TODO(dslomov): report error if not a valid expression.
+    ValidateExpression(&classifier, CHECK_OK);
 
     if (has_seen_constructor && constructor == NULL) {
       constructor = GetPropertyValue(property)->AsFunctionLiteral();
       DCHECK_NOT_NULL(constructor);
     } else {
       properties->Add(property, zone());
     }
 
     if (fni_ != NULL) {
       fni_->Infer();
@@ skipping 31 matching lines @@
 
   int pos = peek_position();
   Expect(Token::MOD, CHECK_OK);
   // Allow "eval" or "arguments" for backward compatibility.
   const AstRawString* name = ParseIdentifier(kAllowRestrictedIdentifiers,
                                              CHECK_OK);
   Scanner::Location spread_pos;
   ExpressionClassifier classifier;
   ZoneList<Expression*>* args =
       ParseArguments(&spread_pos, &classifier, CHECK_OK);
-  // TODO(dslomov): report error if not a valid expression.
+  ValidateExpression(&classifier, CHECK_OK);
 
   DCHECK(!spread_pos.IsValid());
 
   if (extension_ != NULL) {
     // The extension structures are only accessible while parsing the
     // very first time not when reparsing because of lazy compilation.
     scope_->DeclarationScope()->ForceEagerCompilation();
   }
 
   const Runtime::Function* function = Runtime::FunctionForName(name->string());
@@ skipping 1356 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