[parser] make kInvalidLhsInFor a SyntaxError

src/preparser.h

Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index 249eed983c4f4c08485073b60f67651f5a3cb407..1051f97b8af2554510dc0ffd6fe589958511a1b3 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -714,6 +714,9 @@ class ParserBase : public Traits {
   ExpressionT CheckAndRewriteReferenceExpression(
       ExpressionT expression, int beg_pos, int end_pos,
       MessageTemplate::Template message, bool* ok);
+  ExpressionT CheckAndRewriteReferenceExpression(
+      ExpressionT expression, int beg_pos, int end_pos,
+      MessageTemplate::Template message, ParseErrorType type, bool* ok);
 
   // Used to validate property names in object literals and class literals
   enum PropertyKind {
@@ -1473,6 +1476,10 @@ class PreParserTraits {
                                           Handle<Object> arg, int pos) {
     return PreParserExpression::Default();
   }
+  PreParserExpression NewThrowSyntaxError(MessageTemplate::Template message,
+                                          int pos) {
+    return PreParserExpression::Default();
+  }
   PreParserExpression NewThrowTypeError(MessageTemplate::Template message,
                                         Handle<Object> arg, int pos) {
     return PreParserExpression::Default();
@@ -3937,6 +3944,16 @@ typename ParserBase<Traits>::ExpressionT
 ParserBase<Traits>::CheckAndRewriteReferenceExpression(
     ExpressionT expression, int beg_pos, int end_pos,
     MessageTemplate::Template message, bool* ok) {
+  return this->CheckAndRewriteReferenceExpression(expression, beg_pos, end_pos,
+                                                  message, kReferenceError, ok);
+}
+
+
+template <typename Traits>
+typename ParserBase<Traits>::ExpressionT
+ParserBase<Traits>::CheckAndRewriteReferenceExpression(
+    ExpressionT expression, int beg_pos, int end_pos,
+    MessageTemplate::Template message, ParseErrorType type, bool* ok) {
   Scanner::Location location(beg_pos, end_pos);
   if (this->IsIdentifier(expression)) {
     if (is_strict(language_mode()) &&
@@ -3960,10 +3977,12 @@ ParserBase<Traits>::CheckAndRewriteReferenceExpression(
     // If it is a call, make it a runtime error for legacy web compatibility.
     // Rewrite `expr' to `expr[throw ReferenceError]'.
     int pos = location.beg_pos;
-    ExpressionT error = this->NewThrowReferenceError(message, pos);
+    ExpressionT error = type == kReferenceError
+                            ? this->NewThrowReferenceError(message, pos)
+                            : this->NewThrowSyntaxError(message, pos);

[caitp (gmail), 2015/08/14 17:06:17]

I'm not sure if this distinction is necessary or good here --- getting rid of
this does make the patch a lot smaller.

SpiderMonkey does not make the distinction, at any rate.

[adamk, 2015/08/15 01:06:15]

Seems fine to me, and also makes sense tonot throw a SyntaxError at runtime...

     return factory()->NewProperty(expression, error, pos);
   } else {
-    this->ReportMessageAt(location, message, kReferenceError);
+    this->ReportMessageAt(location, message, type);
     *ok = false;
     return this->EmptyExpression();
   }