[modules] Disable HTML-like comments

src/parsing/scanner.cc

 // Copyright 2011 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.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include "src/parsing/scanner.h"
 
 #include <stdint.h>
 
@@ skipping 24 matching lines @@
 
 // ----------------------------------------------------------------------------
 // Scanner
 
 Scanner::Scanner(UnicodeCache* unicode_cache)
     : unicode_cache_(unicode_cache),
       bookmark_c0_(kNoBookmark),
       octal_pos_(Location::invalid()),
       decimal_with_leading_zero_pos_(Location::invalid()),
       found_html_comment_(false),
+      allow_html_comments_(false),
       allow_harmony_exponentiation_operator_(false) {
   bookmark_current_.literal_chars = &bookmark_current_literal_;
   bookmark_current_.raw_literal_chars = &bookmark_current_raw_literal_;
   bookmark_next_.literal_chars = &bookmark_next_literal_;
   bookmark_next_.raw_literal_chars = &bookmark_next_raw_literal_;
 }
 
 
 void Scanner::Initialize(Utf16CharacterStream* source) {
   source_ = source;
@@ skipping 267 matching lines @@
     }
 
     // If there is an HTML comment end '-->' at the beginning of a
     // line (with only whitespace in front of it), we treat the rest
     // of the line as a comment. This is in line with the way
     // SpiderMonkey handles it.
     if (c0_ == '-' && has_line_terminator_before_next_) {
       Advance();
       if (c0_ == '-') {
         Advance();
-        if (c0_ == '>') {
+        if (c0_ == '>' && !allow_html_comments_) {
           // Treat the rest of the line as a comment.
           SkipSingleLineComment();
           // Continue skipping white space after the comment.
           continue;
         }
         PushBack('-');  // undo Advance()
       }
       PushBack('-');  // undo Advance()
     }
     // Return whether or not we skipped any characters.
@@ skipping 104 matching lines @@
   return Token::ILLEGAL;
 }
 
 
 Token::Value Scanner::ScanHtmlComment() {
   // Check for <!-- comments.
   DCHECK(c0_ == '!');
   Advance();
   if (c0_ == '-') {
     Advance();
-    if (c0_ == '-') {
+    if (c0_ == '-' && !allow_html_comments_) {

[vogelheim, 2016/05/27 08:08:49]

nitpick: It seems more logical to check this at the calling site; but that's
admittedly a matter of taste.

[mike3, 2016/05/27 15:53:22]

Maybe, but it's good taste. I was suffering from tunnel vision when I wrote this
(still kind of intimidated by the source). I'll move this to the call site and
update the other references to occur earlier (e.g. no need to scan all the way
through "-->" before checking if these are enabled).

       found_html_comment_ = true;
       return SkipSingleLineComment();
     }
     PushBack('-');  // undo Advance()
   }
   PushBack('!');  // undo Advance()
   DCHECK(c0_ == '!');
   return Token::LT;
 }
 
@@ skipping 89 matching lines @@
         } else {
           token = Token::ADD;
         }
         break;
 
       case '-':
         // - -- --> -=
         Advance();
         if (c0_ == '-') {
           Advance();
-          if (c0_ == '>' && has_line_terminator_before_next_) {
+          if (c0_ == '>' && has_line_terminator_before_next_ &&
+              !allow_html_comments_) {
             // For compatibility with SpiderMonkey, we skip lines that
             // start with an HTML comment end '-->'.
             token = SkipSingleLineComment();
           } else {
             token = Token::DEC;
           }
         } else if (c0_ == '=') {
           token = Select(Token::ASSIGN_SUB);
         } else {
           token = Token::SUB;
@@ skipping 1131 matching lines @@
     backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
   }
   backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
 
   backing_store_.AddBlock(bytes);
   return backing_store_.EndSequence().start();
 }
 
 }  // namespace internal
 }  // namespace v8