Re: [PATCH 12/35] libmultipath: strlcpy()/strlcat(): use restrict qualifier

[Benjamin Marzinski <bmarzins@redhat.com>]

On Thu, Jul 09, 2020 at 12:15:57PM +0200, mwilck@suse.com wrote:
> From: Martin Wilck <mwilck@suse.com>
> 
> Also remove the redundant local variables. It's not necessary to
> make "restrict" work, but it makes the intention more clear.
> 
> Signed-off-by: Martin Wilck <mwilck@suse.com>
> ---
>  libmultipath/util.c | 28 ++++++++++++----------------
>  libmultipath/util.h |  4 ++--
>  2 files changed, 14 insertions(+), 18 deletions(-)
> 
> diff --git a/libmultipath/util.c b/libmultipath/util.c
> index 957fb97..f965094 100644
> --- a/libmultipath/util.c
> +++ b/libmultipath/util.c
> @@ -113,46 +113,42 @@ get_word (const char *sentence, char **word)
>  	return skip + len;
>  }
>  
> -size_t strlcpy(char *dst, const char *src, size_t size)
> +size_t strlcpy(char * restrict dst, const char * restrict src, size_t size)
>  {
>  	size_t bytes = 0;
> -	char *q = dst;
> -	const char *p = src;
>  	char ch;
>  
> -	while ((ch = *p++)) {
> -		if (bytes+1 < size)
> -			*q++ = ch;
> +	while ((ch = *src++)) {
> +		if (bytes + 1 < size)
> +			*dst++ = ch;
>  		bytes++;
>  	}
>  
>  	/* If size == 0 there is no space for a final null... */
>  	if (size)
> -		*q = '\0';
> +		*dst = '\0';
>  	return bytes;
>  }
>  
> -size_t strlcat(char *dst, const char *src, size_t size)
> +size_t strlcat(char * restrict dst, const char * restrict src, size_t size)
>  {
>  	size_t bytes = 0;
> -	char *q = dst;
> -	const char *p = src;
>  	char ch;
>  
> -	while (bytes < size && *q) {
> -		q++;
> +	while (bytes < size && *dst) {
> +		dst++;
>  		bytes++;
>  	}
>  	if (bytes == size)

this should return the strlen(dst) + strlen(src). It wouldn't in the
admittedly weird case where size isn't large enough to fit dst.

>  		return (bytes + strlen(src));
>  
> -	while ((ch = *p++)) {
> -		if (bytes+1 < size)
> -		*q++ = ch;
> +	while ((ch = *src++)) {
> +		if (bytes + 1 < size)
> +			*dst++ = ch;
>  		bytes++;
>  	}
>  
> -	*q = '\0';
> +	*dst = '\0';
>  	return bytes;
>  }
>  
> diff --git a/libmultipath/util.h b/libmultipath/util.h
> index ae18d8b..7e29b26 100644
> --- a/libmultipath/util.h
> +++ b/libmultipath/util.h
> @@ -15,8 +15,8 @@ int basenamecpy (const char *src, char *dst, size_t size);
>  int filepresent (const char *run);
>  char *get_next_string(char **temp, const char *split_char);
>  int get_word (const char * sentence, char ** word);
> -size_t strlcpy(char *dst, const char *src, size_t size);
> -size_t strlcat(char *dst, const char *src, size_t size);
> +size_t strlcpy(char * restrict dst, const char * restrict src, size_t size);
> +size_t strlcat(char * restrict dst, const char * restrict src, size_t size);
>  int devt2devname (char *, int, const char *);
>  dev_t parse_devt(const char *dev_t);
>  char *convert_dev(char *dev, int is_path_device);
> -- 
> 2.26.2