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Re: [PATCH] Use strlen when searching for a nul char

From: Mike Frysinger <vapier at gentoo dot org>
To: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
Cc: 'GNU C Library' <libc-alpha at sourceware dot org>, nd <nd at arm dot com>
Date: Wed, 20 Apr 2016 11:24:13 -0400
Subject: Re: [PATCH] Use strlen when searching for a nul char
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References: <DB3PR08MB008978DA72CE0E1B93BB477483A60 at DB3PR08MB0089 dot eurprd08 dot prod dot outlook dot com> <20160419175706 dot GI5369 at vapier dot lan> <AM3PR08MB0088C41881332E9D5DF94BCC836C0 at AM3PR08MB0088 dot eurprd08 dot prod dot outlook dot com> <20160419222134 dot GQ5369 at vapier dot lan> <AM3PR08MB0088858A7DD08414E65F8375836D0 at AM3PR08MB0088 dot eurprd08 dot prod dot outlook dot com>

On 20 Apr 2016 14:50, Wilco Dijkstra wrote:
>  #ifndef _HAVE_STRING_ARCH_strchr
>  extern void *__rawmemchr (const void *__s, int __c);
> -#  define strchr(s, c) \
> +# define strchr(s, c) \
>    (__extension__ (__builtin_constant_p (c) && !__builtin_constant_p (s)	      \
>  		  && (c) == '\0'					      \
>  		  ? (char *) __rawmemchr (s, c)				      \
>  		  : __builtin_strchr (s, c)))
>  #endif
>  
> +#ifndef _HAVE_STRING_ARCH_rawmemchr
> +extern void *__rawmemchr (const void *__s, int __c);
> +# define __rawmemchr(s, c) \
> +    (__extension__ ({ char *__s = (char *)(s);		\
> +      __builtin_constant_p (c) && (c) == '\0'		\
> +      ? (void *)(__s + strlen (__s))			\
> +      : __rawmemchr (__s, (c));}))
> +# ifdef __USE_GNU
> +#  define rawmemchr(s,c) __rawmemchr ((s), (c))
> +# endif
> +#endif

this relies on _HAVE_STRING_ARCH_strchr & _HAVE_STRING_ARCH_rawmemchr
being in sync in order for the strchr->strlen rewrite.  should we just
do the strlen change in strchr itself too ?
-mike

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Follow-Ups:
- Re: [PATCH] Use strlen when searching for a nul char
  - From: Wilco Dijkstra

References:
- Re: [PATCH] Use strlen when searching for a nul char
  - From: Mike Frysinger
- Re: [PATCH] Use strlen when searching for a nul char
  - From: Wilco Dijkstra
- Re: [PATCH] Use strlen when searching for a nul char
  - From: Mike Frysinger
- Re: [PATCH] Use strlen when searching for a nul char
  - From: Wilco Dijkstra

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