Move ParseAssignmentExpression to ParserBase.

src/preparser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 325 matching lines @@
                                                                   bool* ok);
 
   typename Traits::Type::Expression ParseRegExpLiteral(bool seen_equal,
                                                        bool* ok);
 
   typename Traits::Type::Expression ParsePrimaryExpression(bool* ok);
   typename Traits::Type::Expression ParseExpression(bool accept_IN, bool* ok);
   typename Traits::Type::Expression ParseArrayLiteral(bool* ok);
   typename Traits::Type::Expression ParseObjectLiteral(bool* ok);
   typename Traits::Type::ExpressionList ParseArguments(bool* ok);
+  typename Traits::Type::Expression ParseAssignmentExpression(bool accept_IN,
+                                                              bool* ok);
 
   // Used to detect duplicates in object literals. Each of the values
   // kGetterProperty, kSetterProperty and kValueProperty represents
   // a type of object literal property. When parsing a property, its
   // type value is stored in the DuplicateFinder for the property name.
   // Values are chosen so that having intersection bits means the there is
   // an incompatibility.
   // I.e., you can add a getter to a property that already has a setter, since
   // kGetterProperty and kSetterProperty doesn't intersect, but not if it
   // already has a getter or a value. Adding the getter to an existing
@@ skipping 162 matching lines @@
   bool IsUseStrictLiteral() {
     return (code_ & kStringLiteralMask) == kUseStrictString;
   }
 
   bool IsThis() { return code_ == kThisExpression; }
 
   bool IsThisProperty() { return code_ == kThisPropertyExpression; }
 
   bool IsStrictFunction() { return code_ == kStrictFunctionExpression; }
 
+  // Dummy implementation for making expression->AsCall() work (see below).
+  PreParserExpression* operator->() { return this; }
+
+  // These are only used when doing function name inferring, and PreParser
+  // doesn't do function name inferring.
+  void* AsCall() const { return NULL; }
+  void* AsCallNew() const { return NULL; }
+
  private:
   // First two/three bits are used as flags.
   // Bit 0 and 1 represent identifiers or strings literals, and are
   // mutually exclusive, but can both be absent.
   enum {
     kUnknownExpression = 0,
     // Identifiers
     kIdentifierFlag = 1,  // Used to detect labels.
     kIdentifierShift = 3,
 
@@ skipping 99 matching lines @@
 
   PreParserExpression NewLiteral(PreParserIdentifier identifier,
                                  int pos) {
     return PreParserExpression::Default();
   }
 
   PreParserExpression NewNumberLiteral(double number,
                                        int pos) {
     return PreParserExpression::Default();
   }
+
+  PreParserExpression NewAssignment(Token::Value op,
+                                    PreParserExpression left,
+                                    PreParserExpression right,
+                                    int pos) {
+    return PreParserExpression::Default();
+  }
 };
 
 
 class PreParser;
 
 class PreParserTraits {
  public:
   struct Type {
     typedef PreParser* Parser;
 
@@ skipping 22 matching lines @@
   template<typename FunctionState>
   static void SetUpFunctionState(FunctionState* function_state, void*) {}
   template<typename FunctionState>
   static void TearDownFunctionState(FunctionState* function_state) {}
 
   // Helper functions for recursive descent.
   static bool IsEvalOrArguments(PreParserIdentifier identifier) {
     return identifier.IsEvalOrArguments();
   }
 
+  // Returns true if the expression is of type "this.foo".
+  static bool IsThisProperty(PreParserExpression expression) {
+    return expression.IsThisProperty();
+  }
+
   static bool IsBoilerplateProperty(PreParserExpression property) {
     // PreParser doesn't count boilerplate properties.
     return false;
   }
 
   static bool IsArrayIndex(PreParserIdentifier string, uint32_t* index) {
     return false;
   }
 
+  // Functions for encapsulating the differences between parsing and preparsing;
+  // operations interleaved with the recursive descent.
   static void PushLiteralName(FuncNameInferrer* fni, PreParserIdentifier id) {
     // PreParser should not use FuncNameInferrer.
     ASSERT(false);
   }
 
   static void CheckFunctionLiteralInsideTopLevelObjectLiteral(
       PreParserScope* scope, PreParserExpression value, bool* has_function) {}
 
+  static void CheckAssigningFunctionLiteralToProperty(
+      PreParserExpression left, PreParserExpression right) {}
+
+
+  static PreParserExpression ValidateAssignmentLeftHandSide(
+      PreParserExpression expression) {
+    // Parser generates a runtime error here if the left hand side is not valid.
+    // PreParser doesn't have to.
+    return expression;
+  }
+
+  static PreParserExpression MarkExpressionAsLValue(
+      PreParserExpression expression) {
+    // TODO(marja): To be able to produce the same errors, the preparser needs
+    // to start tracking which expressions are variables and which are lvalues.
+    return expression;
+  }
+
+  // Checks LHS expression for assignment and prefix/postfix increment/decrement
+  // in strict mode.
+  void CheckStrictModeLValue(PreParserExpression expression, bool* ok);
+
+
   // Reporting errors.
   void ReportMessageAt(Scanner::Location location,
                        const char* message,
                        Vector<const char*> args);
   void ReportMessageAt(Scanner::Location location,
                        const char* type,
                        const char* name_opt);
   void ReportMessageAt(int start_pos,
                        int end_pos,
                        const char* type,
@@ skipping 49 matching lines @@
 
   static PreParserExpressionList NewExpressionList(int size, void* zone) {
     return PreParserExpressionList();
   }
 
   static PreParserExpressionList NewPropertyList(int size, void* zone) {
     return PreParserExpressionList();
   }
 
   // Temporary glue; these functions will move to ParserBase.
-  PreParserExpression ParseAssignmentExpression(bool accept_IN, bool* ok);
   PreParserExpression ParseV8Intrinsic(bool* ok);
   PreParserExpression ParseFunctionLiteral(
       PreParserIdentifier name,
       Scanner::Location function_name_location,
       bool name_is_strict_reserved,
       bool is_generator,
       int function_token_position,
       FunctionLiteral::FunctionType type,
       bool* ok);
+  PreParserExpression ParseYieldExpression(bool* ok);
+  PreParserExpression ParseConditionalExpression(bool accept_IN, bool* ok);
 
  private:
   PreParser* pre_parser_;
 };
 
 
 // Preparsing checks a JavaScript program and emits preparse-data that helps
 // a later parsing to be faster.
 // See preparse-data-format.h for the data format.
 
@@ skipping 144 matching lines @@
   Statement ParseBreakStatement(bool* ok);
   Statement ParseReturnStatement(bool* ok);
   Statement ParseWithStatement(bool* ok);
   Statement ParseSwitchStatement(bool* ok);
   Statement ParseDoWhileStatement(bool* ok);
   Statement ParseWhileStatement(bool* ok);
   Statement ParseForStatement(bool* ok);
   Statement ParseThrowStatement(bool* ok);
   Statement ParseTryStatement(bool* ok);
   Statement ParseDebuggerStatement(bool* ok);
-
-  Expression ParseAssignmentExpression(bool accept_IN, bool* ok);
   Expression ParseYieldExpression(bool* ok);
   Expression ParseConditionalExpression(bool accept_IN, bool* ok);
   Expression ParseBinaryExpression(int prec, bool accept_IN, bool* ok);
   Expression ParseUnaryExpression(bool* ok);
   Expression ParsePostfixExpression(bool* ok);
   Expression ParseLeftHandSideExpression(bool* ok);
   Expression ParseMemberExpression(bool* ok);
   Expression ParseMemberExpressionContinuation(PreParserExpression expression,
                                                bool* ok);
   Expression ParseMemberWithNewPrefixesExpression(bool* ok);
@@ skipping 532 matching lines @@
     done = (peek() == Token::RPAREN);
     if (!done) {
       // Need {} because of the CHECK_OK_CUSTOM macro.
       Expect(Token::COMMA, CHECK_OK_CUSTOM(NullExpressionList));
     }
   }
   Expect(Token::RPAREN, CHECK_OK_CUSTOM(NullExpressionList));
   return result;
 }
 
+// Precedence = 2
+template <class Traits>
+typename Traits::Type::Expression ParserBase<Traits>::ParseAssignmentExpression(
+    bool accept_IN, bool* ok) {
+  // AssignmentExpression ::
+  //   ConditionalExpression
+  //   YieldExpression
+  //   LeftHandSideExpression AssignmentOperator AssignmentExpression
+
+  if (peek() == Token::YIELD && is_generator()) {
+    return this->ParseYieldExpression(ok);

[Michael Starzinger, 2014/03/13 08:52:41]

As discussed offline: It would be nice to get rid of all this explicit "this->"
prefixes. But since this is on your plate as final cleanup anyways, I am fine
with it.

[rossberg, 2014/03/13 09:25:34]

FWIW, I like the explicit this->, and would prefer a style guide that requires
them, always. Makes reading and esp refactoring so much easier. Remember
handlification? :)

+  }
+
+  if (fni_ != NULL) fni_->Enter();
+  typename Traits::Type::Expression expression =
+      this->ParseConditionalExpression(accept_IN, CHECK_OK);
+
+  if (!Token::IsAssignmentOp(peek())) {
+    if (fni_ != NULL) fni_->Leave();
+    // Parsed conditional expression only (no assignment).
+    return expression;
+  }
+
+  // Signal a reference error if the expression is an invalid left-hand
+  // side expression.  We could report this as a syntax error here but
+  // for compatibility with JSC we choose to report the error at
+  // runtime.
+  // TODO(ES5): Should change parsing for spec conformance.
+  expression = this->ValidateAssignmentLeftHandSide(expression);
+
+  if (strict_mode() == STRICT) {
+    // Assignment to eval or arguments is disallowed in strict mode.
+    CheckStrictModeLValue(expression, CHECK_OK);
+  }
+  expression = this->MarkExpressionAsLValue(expression);
+
+  Token::Value op = Next();  // Get assignment operator.
+  int pos = position();
+  typename Traits::Type::Expression right =
+      this->ParseAssignmentExpression(accept_IN, CHECK_OK);
+
+  // TODO(1231235): We try to estimate the set of properties set by
+  // constructors. We define a new property whenever there is an
+  // assignment to a property of 'this'. We should probably only add
+  // properties if we haven't seen them before. Otherwise we'll
+  // probably overestimate the number of properties.
+  if (op == Token::ASSIGN && this->IsThisProperty(expression)) {
+    function_state_->AddProperty();
+  }
+
+  this->CheckAssigningFunctionLiteralToProperty(expression, right);
+
+  if (fni_ != NULL) {
+    // Check if the right hand side is a call to avoid inferring a
+    // name if we're dealing with "a = function(){...}();"-like
+    // expression.
+    if ((op == Token::INIT_VAR
+         || op == Token::INIT_CONST_LEGACY
+         || op == Token::ASSIGN)
+        && (right->AsCall() == NULL && right->AsCallNew() == NULL)) {
+      fni_->Infer();
+    } else {
+      fni_->RemoveLastFunction();
+    }
+    fni_->Leave();
+  }
+
+  return factory()->NewAssignment(op, expression, right, pos);
+}
 
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM
 
 
 template <typename Traits>
 void ParserBase<Traits>::ObjectLiteralChecker::CheckProperty(
     Token::Value property,
     PropertyKind type,
     bool* ok) {
@@ skipping 23 matching lines @@
                                "accessor_get_set");
     }
     *ok = false;
   }
 }
 
 
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H