Two changes, one a refactoring and one that affects V8's JS semantics....

src/parser.cc

Index: src/parser.cc
===================================================================
--- src/parser.cc	(revision 2993)
+++ src/parser.cc	(working copy)
@@ -2660,25 +2660,13 @@
     } else {
       Expression* expression = ParseExpression(false, CHECK_OK);
       if (peek() == Token::IN) {
-        // Report syntax error if the expression is an invalid
-        // left-hand side 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.
         if (expression == NULL || !expression->IsValidLeftHandSide()) {
-          if (expression != NULL && expression->AsCall() != NULL) {
-            // According to ECMA-262 host function calls are permitted to
-            // return references.  This cannot happen in our system so we
-            // will always get an error.  We could report this as a syntax
-            // error here but for compatibility with KJS and SpiderMonkey we
-            // choose to report the error at runtime.
-            Handle<String> type = Factory::invalid_lhs_in_for_in_symbol();
-            expression = NewThrowReferenceError(type);
-          } else {
-            // Invalid left hand side expressions that are not function
-            // calls are reported as syntax errors at compile time.
-            ReportMessage("invalid_lhs_in_for_in",
-                          Vector<const char*>::empty());
-            *ok = false;
-            return NULL;
-          }
+          Handle<String> type = Factory::invalid_lhs_in_for_in_symbol();
+          expression = NewThrowReferenceError(type);
         }
         ForInStatement* loop = NEW(ForInStatement(labels));
         Target target(this, loop);
@@ -2755,30 +2743,15 @@
     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.
   if (expression == NULL || !expression->IsValidLeftHandSide()) {
-    if (expression != NULL && expression->AsCall() != NULL) {
-      // According to ECMA-262 host function calls are permitted to
-      // return references.  This cannot happen in our system so we
-      // will always get an error.  We could report this as a syntax
-      // error here but for compatibility with KJS and SpiderMonkey we
-      // choose to report the error at runtime.
-      Handle<String> type = Factory::invalid_lhs_in_assignment_symbol();
-      expression = NewThrowReferenceError(type);
-    } else {
-      // Invalid left hand side expressions that are not function
-      // calls are reported as syntax errors at compile time.
-      //
-      // NOTE: KJS sometimes delay the error reporting to runtime. If
-      // we want to be completely compatible we should do the same.
-      // For example: "(x++) = 42" gives a reference error at runtime
-      // with KJS whereas we report a syntax error at compile time.
-      ReportMessage("invalid_lhs_in_assignment", Vector<const char*>::empty());
-      *ok = false;
-      return NULL;
-    }
+    Handle<String> type = Factory::invalid_lhs_in_assignment_symbol();
+    expression = NewThrowReferenceError(type);
   }
 
-
   Token::Value op = Next();  // Get assignment operator.
   int pos = scanner().location().beg_pos;
   Expression* right = ParseAssignmentExpression(accept_IN, CHECK_OK);
@@ -2951,45 +2924,37 @@
   Token::Value op = peek();
   if (Token::IsUnaryOp(op)) {
     op = Next();
-    Expression* x = ParseUnaryExpression(CHECK_OK);
+    Expression* expression = ParseUnaryExpression(CHECK_OK);
 
     // Compute some expressions involving only number literals.
-    if (x && x->AsLiteral() && x->AsLiteral()->handle()->IsNumber()) {
-      double x_val = x->AsLiteral()->handle()->Number();
+    if (expression != NULL && expression->AsLiteral() &&
+        expression->AsLiteral()->handle()->IsNumber()) {
+      double value = expression->AsLiteral()->handle()->Number();
       switch (op) {
         case Token::ADD:
-          return x;
+          return expression;
         case Token::SUB:
-          return NewNumberLiteral(-x_val);
+          return NewNumberLiteral(-value);
         case Token::BIT_NOT:
-          return NewNumberLiteral(~DoubleToInt32(x_val));
+          return NewNumberLiteral(~DoubleToInt32(value));
         default: break;
       }
     }
 
-    return NEW(UnaryOperation(op, x));
+    return NEW(UnaryOperation(op, expression));
 
   } else if (Token::IsCountOp(op)) {
     op = Next();
-    Expression* x = ParseUnaryExpression(CHECK_OK);
-    if (x == NULL || !x->IsValidLeftHandSide()) {
-      if (x != NULL && x->AsCall() != NULL) {
-        // According to ECMA-262 host function calls are permitted to
-        // return references.  This cannot happen in our system so we
-        // will always get an error.  We could report this as a syntax
-        // error here but for compatibility with KJS and SpiderMonkey we
-        // choose to report the error at runtime.
-        Handle<String> type = Factory::invalid_lhs_in_prefix_op_symbol();
-        x = NewThrowReferenceError(type);
-      } else {
-        // Invalid left hand side expressions that are not function
-        // calls are reported as syntax errors at compile time.
-        ReportMessage("invalid_lhs_in_prefix_op", Vector<const char*>::empty());
-        *ok = false;
-        return NULL;
-      }
+    Expression* expression = ParseUnaryExpression(CHECK_OK);
+    // 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.
+    if (expression == NULL || !expression->IsValidLeftHandSide()) {
+      Handle<String> type = Factory::invalid_lhs_in_prefix_op_symbol();
+      expression = NewThrowReferenceError(type);
     }
-    return NEW(CountOperation(true /* prefix */, op, x));
+    return NEW(CountOperation(true /* prefix */, op, expression));
 
   } else {
     return ParsePostfixExpression(ok);
@@ -3001,30 +2966,20 @@
   // PostfixExpression ::
   //   LeftHandSideExpression ('++' | '--')?
 
-  Expression* result = ParseLeftHandSideExpression(CHECK_OK);
+  Expression* expression = ParseLeftHandSideExpression(CHECK_OK);
   if (!scanner_.has_line_terminator_before_next() && Token::IsCountOp(peek())) {
-    if (result == NULL || !result->IsValidLeftHandSide()) {
-      if (result != NULL && result->AsCall() != NULL) {
-        // According to ECMA-262 host function calls are permitted to
-        // return references.  This cannot happen in our system so we
-        // will always get an error.  We could report this as a syntax
-        // error here but for compatibility with KJS and SpiderMonkey we
-        // choose to report the error at runtime.
-        Handle<String> type = Factory::invalid_lhs_in_postfix_op_symbol();
-        result = NewThrowReferenceError(type);
-      } else {
-        // Invalid left hand side expressions that are not function
-        // calls are reported as syntax errors at compile time.
-        ReportMessage("invalid_lhs_in_postfix_op",
-                      Vector<const char*>::empty());
-        *ok = false;
-        return NULL;
-      }
+    // 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.
+    if (expression == NULL || !expression->IsValidLeftHandSide()) {
+      Handle<String> type = Factory::invalid_lhs_in_postfix_op_symbol();
+      expression = NewThrowReferenceError(type);
     }
     Token::Value next = Next();
-    result = NEW(CountOperation(false /* postfix */, next, result));
+    expression = NEW(CountOperation(false /* postfix */, next, expression));
   }
-  return result;
+  return expression;
 }