[prev in list] [next in list] [prev in thread] [next in thread]
List: kwrite-devel
Subject: Re: Review Request 111754: syntax highlighter must deal more robustly with infinite loops
From: "Bruno Vasselle" <bruno.vasselle () laposte ! net>
Date: 2013-12-26 19:08:03
Message-ID: 20131226190803.27906.45975 () probe ! kde ! org
[Download RAW message or body]
[Attachment #2 (multipart/alternative)]
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/111754/
-----------------------------------------------------------
(Updated Dec. 26, 2013, 7:08 p.m.)
Status
------
This change has been marked as submitted.
Review request for Kate, Christoph Cullmann, Dominik Haumann, and Milian Wolff.
Repository: kate
Description
-------
The syntax highlighter currently has some kind of protection against infinite loops \
induced by buggy highlighting XML. Resolution of bug 144599 is an example of such a \
protection.
However, with such concepts as "lookAhead", which basically matches null strings, the \
risk of infinite loops cannot be sanely guaranteed by ad-hoc patches produced on an \
on-bug basis, but rather requires a framework that per se offers such a guaranty.
The patch proposes an implementation for this. It registers the current state, in \
terms of offset within the line coupled with context so that it is able to branch to \
"no match" when it encounters the same situation twice. The "no match" branch in turn \
does not loop on an already encountered context, but rather leads to the default \
path, which increments the offset.
The patch is a few lines long, but requires indentation, which leads to white space \
noise.
Test XML and text are included for the specific case of some infinite loops not dealt \
until now.
Diffs
-----
part/syntax/katehighlight.cpp f44f74e
tests/data/syntax/infinite.txt PRE-CREATION
tests/data/syntax/infinite.xml PRE-CREATION
Diff: https://git.reviewboard.kde.org/r/111754/diff/
Testing
-------
Opened randomly files with different syntaxes. Opened specifically infinite.xml with \
XML highlighter, and infinite.txt with infinite.xml highlighter.
infinite.txt with infinite.xml highlighter falls into infinite loop without the \
patch.
Thanks,
Bruno Vasselle
[Attachment #5 (text/html)]
<html>
<body>
<div style="font-family: Verdana, Arial, Helvetica, Sans-Serif;">
<table bgcolor="#f9f3c9" width="100%" cellpadding="8" style="border: 1px #c9c399 \
solid;"> <tr>
<td>
This is an automatically generated e-mail. To reply, visit:
<a href="https://git.reviewboard.kde.org/r/111754/">https://git.reviewboard.kde.org/r/111754/</a>
</td>
</tr>
</table>
<br />
<table bgcolor="#e0e0e0" width="100%" cellpadding="8" style="border: 1px gray \
solid;"> <tr>
<td>
<h1 style="margin-right: 0.2em; padding: 0; font-size: 10pt;">This change has been \
marked as submitted.</h1> </td>
</tr>
</table>
<br />
<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="8" \
style="background-image: \
url('https://git.reviewboard.kde.org/static/rb/images/review_request_box_top_bg.ab6f3b1072c9.png'); \
background-position: left top; background-repeat: repeat-x; border: 1px black \
solid;"> <tr>
<td>
<div>Review request for Kate, Christoph Cullmann, Dominik Haumann, and Milian \
Wolff.</div> <div>By Bruno Vasselle.</div>
<p style="color: grey;"><i>Updated Dec. 26, 2013, 7:08 p.m.</i></p>
<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt;">Repository: </b>
kate
</div>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0"> <tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">The syntax highlighter currently has some kind of protection against \
infinite loops induced by buggy highlighting XML. Resolution of bug 144599 is an \
example of such a protection.
However, with such concepts as "lookAhead", which basically matches null \
strings, the risk of infinite loops cannot be sanely guaranteed by ad-hoc patches \
produced on an on-bug basis, but rather requires a framework that per se offers such \
a guaranty.
The patch proposes an implementation for this. It registers the current state, in \
terms of offset within the line coupled with context so that it is able to branch to \
"no match" when it encounters the same situation twice. The "no \
match" branch in turn does not loop on an already encountered context, but \
rather leads to the default path, which increments the offset.
The patch is a few lines long, but requires indentation, which leads to white space \
noise.
Test XML and text are included for the specific case of some infinite loops not dealt \
until now. </pre>
</td>
</tr>
</table>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0"> <tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">Opened randomly files with different syntaxes. Opened specifically \
infinite.xml with XML highlighter, and infinite.txt with infinite.xml highlighter.
infinite.txt with infinite.xml highlighter falls into infinite loop without the \
patch.</pre> </td>
</tr>
</table>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">
<li>part/syntax/katehighlight.cpp <span style="color: grey">(f44f74e)</span></li>
<li>tests/data/syntax/infinite.txt <span style="color: \
grey">(PRE-CREATION)</span></li>
<li>tests/data/syntax/infinite.xml <span style="color: \
grey">(PRE-CREATION)</span></li>
</ul>
<p><a href="https://git.reviewboard.kde.org/r/111754/diff/" style="margin-left: \
3em;">View Diff</a></p>
</td>
</tr>
</table>
</div>
</body>
</html>
_______________________________________________
KWrite-Devel mailing list
KWrite-Devel@kde.org
https://mail.kde.org/mailman/listinfo/kwrite-devel
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic