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From: Conor Williams <conor.williams@gmail.com>
To: 9fans <9fans@9fans.net>
Subject: Re: [9fans] Fix sam regexp bug with metacharacters in classes
Date: Wed, 24 Nov 2021 01:29:31 +0000	[thread overview]
Message-ID: <CAL6pNZ-LSyfbjjqMeA_48agb_rzF_8zfszy4=Rz=kPVXro5GWg@mail.gmail.com> (raw)
In-Reply-To: <CAL6pNZ8HJeceN8ozPYycGpTg_xPF09Q67qdbX3VvZmscpGjGwA@mail.gmail.com>

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sorry that s should have a k preceding _ /c:2021248pm

On Wed, Nov 24, 2021 at 1:28 AM Conor Williams <conor.williams@gmail.com>
wrote:

> why on Gaia do you not have a
> Runemas_Incremented_By_One_To_Keep_A_Negative_Sub
> variable?
> apart from that, it looks okay... will tango it in later...
>
> /c:2022November!^N^M
>
> 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){
>> 

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  reply	other threads:[~2021-11-24  1:29 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 [this message]
2021-12-25  3:10 ` Conor Williams
2021-12-25  5:35 ` Conor Williams

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