[parser] Fix fatal error on spread in class properties

Bug: v8:6337
Change-Id: I7de330c77e5f4cbb2cd4bf327c8b60783e78880c
Reviewed-on: https://chromium-review.googlesource.com/493786
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45043}

src/parsing/parser-base.h

@@ -2259,12 +2259,12 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
 
   Token::Value name_token = peek();
 
-  int function_token_position = scanner()->peek_location().beg_pos;
+  int name_token_position = scanner()->peek_location().beg_pos;
   IdentifierT name = impl()->EmptyIdentifier();
   ExpressionT name_expression;
   if (name_token == Token::STATIC) {
     Consume(Token::STATIC);
-    function_token_position = scanner()->peek_location().beg_pos;
+    name_token_position = scanner()->peek_location().beg_pos;
     if (peek() == Token::LPAREN) {
       kind = PropertyKind::kMethodProperty;
       name = impl()->GetSymbol();  // TODO(bakkot) specialize on 'static'
@@ -2342,7 +2342,7 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
 
       ExpressionT value = impl()->ParseFunctionLiteral(
           name, scanner()->location(), kSkipFunctionNameCheck, kind,
-          FLAG_harmony_function_tostring ? function_token_position
+          FLAG_harmony_function_tostring ? name_token_position
                                          : kNoSourcePosition,
           FunctionLiteral::kAccessorOrMethod, language_mode(),
           CHECK_OK_CUSTOM(EmptyClassLiteralProperty));
@@ -2372,7 +2372,7 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
 
       FunctionLiteralT value = impl()->ParseFunctionLiteral(
           name, scanner()->location(), kSkipFunctionNameCheck, kind,
-          FLAG_harmony_function_tostring ? function_token_position
+          FLAG_harmony_function_tostring ? name_token_position
                                          : kNoSourcePosition,
           FunctionLiteral::kAccessorOrMethod, language_mode(),
           CHECK_OK_CUSTOM(EmptyClassLiteralProperty));
@@ -2388,7 +2388,11 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
                                                 *is_computed_name);
     }
     case PropertyKind::kSpreadProperty:
-      UNREACHABLE();
+      ReportUnexpectedTokenAt(
+          Scanner::Location(name_token_position, name_expression->position()),
+          name_token);
+      *ok = false;
+      return impl()->EmptyClassLiteralProperty();
   }
   UNREACHABLE();
   return impl()->EmptyClassLiteralProperty();

test/message/class-spread-property.js

+// Copyright 2017 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.
+
+class C { ...[] }

test/message/class-spread-property.out

+*%(basename)s:5: SyntaxError: Unexpected token ...
+class C { ...[] }
+          ^^^
+SyntaxError: Unexpected token ...
\ No newline at end of file

test/mjsunit/regress/regress-6337.js

+// Copyright 2017 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.
+
+assertThrows(function() { eval(`class C { ...[] }`); } )