[es8] Report proper syntax error for tail call expressions in for-in and for-of bodies.

src/parsing/preparser.cc

Index: src/parsing/preparser.cc
diff --git a/src/parsing/preparser.cc b/src/parsing/preparser.cc
index f1ef8ab60b384b9adac6b9e7e17aec20d8589d0d..a670b3e44be1c0c0b4e5bca533e1096fc38c371e 100644
--- a/src/parsing/preparser.cc
+++ b/src/parsing/preparser.cc
@@ -693,9 +693,15 @@ PreParser::Statement PreParser::ParseReturnStatement(bool* ok) {
       tok != Token::EOS) {
     ParseExpression(true, CHECK_OK);
     if (tail_call_position >= 0) {
-      if (!function_state_->collect_expressions_in_tail_position()) {
+      ReturnExprContext return_expr_context =
+          function_state_->return_expr_context();
+      if (return_expr_context != ReturnExprContext::kNormal) {
         Scanner::Location loc(tail_call_position, tail_call_position + 1);
-        ReportMessageAt(loc, MessageTemplate::kTailCallInTryBlock);
+        MessageTemplate::Template msg =
+            return_expr_context == ReturnExprContext::kInsideTryBlock

[rossberg, 2016/04/27 11:12:01]

Use a switch here, to be robust against extensions of the enum.

[Igor Sheludko, 2016/04/27 11:39:47]

I moved this code to ReportIllegalTailCallAt() to the base class.

+                ? MessageTemplate::kTailCallInTryBlock
+                : MessageTemplate::kTailCallInForInOf;
+        ReportMessageAt(loc, msg);
         *ok = false;
         return Statement::Default();
       }
@@ -850,7 +856,11 @@ PreParser::Statement PreParser::ParseForStatement(bool* ok) {
         }
 
         Expect(Token::RPAREN, CHECK_OK);
-        ParseScopedStatement(true, CHECK_OK);
+        {
+          ReturnExprScope no_tail_calls(function_state_,
+                                        ReturnExprContext::kInsideForInOfBody);
+          ParseScopedStatement(true, CHECK_OK);
+        }
         return Statement::Default();
       }
     } else {
@@ -953,7 +963,8 @@ PreParser::Statement PreParser::ParseTryStatement(bool* ok) {
   Expect(Token::TRY, CHECK_OK);
 
   {
-    DontCollectExpressionsInTailPositionScope no_tail_calls(function_state_);
+    ReturnExprScope no_tail_calls(function_state_,
+                                  ReturnExprContext::kInsideTryBlock);
     ParseBlock(CHECK_OK);
   }