9fans - fans of the OS Plan 9 from Bell Labs
 help / color / mirror / Atom feed
From: Conor Williams <conor.williams@gmail.com>
To: 9fans <9fans@9fans.net>
Subject: Re: [9fans] Fix sam regexp bug with metacharacters in classes
Date: Sat, 25 Dec 2021 05:35:31 +0000	[thread overview]
Message-ID: <CAL6pNZ8H_hPDLdRa7_s0rBSA-4F65W8ukFQ7AWB+eT34S8XhMA@mail.gmail.com> (raw)
In-Reply-To: <171b6946-5a63-f723-b2c9-713ffcfea9e@SDF.ORG>

[-- Attachment #1: Type: text/plain, Size: 2570 bytes --]

are u getting confused between Runemax and Runemask...

I'm going to have my christmas dinner now ;; and reckon this patch
would break a few things... i'm working off a mounted iso at the minute...
it's handier: as in i have "-t iso9660" in it..

laters...
/c:2021 crimbo hay
ps: the jury is out on this one 'till after christmas but i'm not...
pps: am i close?..
ppps: in bb vi a search for minus both ways works...
ppps: should have an answer for you soon as to whether I would run with
this patch


On Tue, Nov 23, 2021 at 8:27 PM adr <adr@sdf.org> wrote:

> The code assumes runes are 16 bits long, not 21, creating faulting
> code parsing classes. I.e. '/[\-]' will not match '-'.
> 
> This is the same fix already in 9front.
> 
> http://adr.freeshell.org/plan9/patches/sam_fix_metachars_on_classes.diff
> 
> --- /sys/src/cmd/sam/regexp.c   Tue Apr 23 19:06:01 2013
> +++ regexp.c    Tue Nov 23 15:01:18 2021
> @@ -53,8 +53,8 @@
>   /*
>    * Actions and Tokens
>    *
> - *     0x100xx are operators, value == precedence
> - *     0x200xx are tokens, i.e. operands for operators
> + *     0x2000xx are operators, value == precedence
> + *     0x3000xx are tokens, i.e. operands for operators
>    */
>   enum {
>         OPERATOR = Runemask+1,  /* Bitmask of all operators */
> @@ -462,7 +462,8 @@
>                         exprp++;
>                         return '\n';
>                 }
> -               return *exprp++|(Runemax+1);
> +               /* add a flag so metacharacters aren't interpreted */
> +               return *exprp++|(Runemask+1);
>         }
>         return *exprp++;
>   }
> @@ -498,11 +499,12 @@
>                         if((c2 = nextrec()) == ']')
>                                 goto Error;
>                         classp[n+0] = Runemax;
> -                       classp[n+1] = c1;
> -                       classp[n+2] = c2;
> +                       /* remove possible flag from nextrec() */
> +                       classp[n+1] = c1 & Runemask;
> +                       classp[n+2] = c2 & Runemask;
>                         n += 3;
>                 }else
> -                       classp[n++] = c1;
> +                       classp[n++] = c1 & Runemask;
>         }
>         classp[n] = 0;
>         if(nclass == Nclass){
> 

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/Tccbdb20b670003a1-Mde1c714fd9ca1af9f3407d8d
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription

[-- Attachment #2: Type: text/html, Size: 5515 bytes --]

      parent reply	other threads:[~2021-12-25  5:35 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-23 20:26 adr
2021-11-24  1:28 ` Conor Williams
2021-11-24  1:29   ` Conor Williams
2021-12-25  3:10 ` Conor Williams
2021-12-25  5:35 ` Conor Williams [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAL6pNZ8H_hPDLdRa7_s0rBSA-4F65W8ukFQ7AWB+eT34S8XhMA@mail.gmail.com \
    --to=conor.williams@gmail.com \
    --cc=9fans@9fans.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).