[error messages] Enhance the "unexpected identifier" error message

Bug: chromium:1338838
Change-Id: I1b8c54b460d272b19a4faa180a491e725bee4b79
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3726147Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81658}

src/common/message-template.h

@@ -605,7 +605,7 @@ namespace internal {
   T(UnexpectedTokenUnaryExponentiation,                                        \
     "Unary operator used immediately before exponentiation expression. "       \
     "Parenthesis must be used to disambiguate operator precedence")            \
-  T(UnexpectedTokenIdentifier, "Unexpected identifier")                        \
+  T(UnexpectedTokenIdentifier, "Unexpected identifier '%'")                    \
   T(UnexpectedTokenNumber, "Unexpected number")                                \
   T(UnexpectedTokenString, "Unexpected string")                                \
   T(UnexpectedTokenRegExp, "Unexpected regular expression")                    \

src/parsing/parser.cc

@@ -107,7 +107,10 @@ void Parser::ReportUnexpectedTokenAt(Scanner::Location location,
     case Token::PRIVATE_NAME:
     case Token::IDENTIFIER:
       message = MessageTemplate::kUnexpectedTokenIdentifier;
-      break;
+      // Use ReportMessageAt with the AstRawString parameter; skip the
+      // ReportMessageAt below.
+      ReportMessageAt(location, message, GetIdentifier());
+      return;
     case Token::AWAIT:
     case Token::ENUM:
       message = MessageTemplate::kUnexpectedReserved;
@@ -119,6 +122,7 @@ void Parser::ReportUnexpectedTokenAt(Scanner::Location location,
       message = is_strict(language_mode())
                     ? MessageTemplate::kUnexpectedStrictReserved
                     : MessageTemplate::kUnexpectedTokenIdentifier;
+      arg = Token::String(token);
       break;
     case Token::TEMPLATE_SPAN:
     case Token::TEMPLATE_TAIL:

test/inspector/debugger/break-on-exception-compiler-errors-expected.txt

@@ -25,7 +25,7 @@ Runtime.evaluate exceptionDetails:
     columnNumber : 2
     exception : {
         className : SyntaxError
-        description : SyntaxError: Unexpected identifier
+        description : SyntaxError: Unexpected identifier 'x'
         objectId : <objectId>
         subtype : error
         type : object
@@ -68,7 +68,7 @@ Runs eval('x x')
 paused on exception:
 {
     className : SyntaxError
-    description : SyntaxError: Unexpected identifier     at <anonymous>:1:1
+    description : SyntaxError: Unexpected identifier 'x'     at <anonymous>:1:1
     objectId : <objectId>
     subtype : error
     type : object
@@ -79,7 +79,7 @@ Runtime.evaluate exceptionDetails:
     columnNumber : 2
     exception : {
         className : SyntaxError
-        description : SyntaxError: Unexpected identifier     at <anonymous>:1:1
+        description : SyntaxError: Unexpected identifier 'x'     at <anonymous>:1:1
         objectId : <objectId>
         subtype : error
         type : object

test/inspector/runtime/compile-script-expected.txt

@@ -52,7 +52,7 @@ compilation result:
             columnNumber : 13
             exception : {
                 className : SyntaxError
-                description : SyntaxError: Unexpected identifier
+                description : SyntaxError: Unexpected identifier 'f'
                 objectId : <objectId>
                 subtype : error
                 type : object

test/message/fail/destructuring-object-private-name.out

-*%(basename)s:8: SyntaxError: Unexpected identifier
+*%(basename)s:8: SyntaxError: Unexpected identifier '#x'
     const { #x: x } = this;
             ^^
-SyntaxError: Unexpected identifier
+SyntaxError: Unexpected identifier '#x'

test/message/fail/nf-yield-in-generator.out

-*%(basename)s:6: SyntaxError: Unexpected identifier
+*%(basename)s:6: SyntaxError: Unexpected identifier 'yield'
   function yield() {}
            ^^^^^
-SyntaxError: Unexpected identifier
+SyntaxError: Unexpected identifier 'yield'

test/message/fail/nfe-yield-generator.out

-*%(basename)s:5: SyntaxError: Unexpected identifier
+*%(basename)s:5: SyntaxError: Unexpected identifier 'yield'
 (function* yield() {})
            ^^^^^
-SyntaxError: Unexpected identifier
+SyntaxError: Unexpected identifier 'yield'

test/message/fail/unexpected-identifier.js

+// Copyright 2022 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.
+
+foo bar

test/message/fail/unexpected-identifier.out

+# Copyright 2016 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.
+
+*%(basename)s:5: SyntaxError: Unexpected identifier 'bar'
+foo bar
+    ^^^
+SyntaxError: Unexpected identifier 'bar'