Re: [PATCH v2 10/12] gaih_inet: split loopback lookup into its own function

[DJ Delorie <dj@redhat.com>]

Siddhesh Poyarekar via Libc-alpha <libc-alpha@sourceware.org> writes:

> Flatten the condition nesting and replace the alloca for RET.AT/ATR with
> a single array LOCAL_AT[2].  This gets rid of alloca and alloca
> accounting.
>
> `git diff -b` is probably the best way to view this change since much of
> the diff is whitespace changes.

reviewing alternate diff then... ;-)

LGTM.

Reviewed-by: DJ Delorie <dj@redhat.com>

> +/* Add local address information into RES.  RES->AT is assumed to have enough
> +   space for two tuples and is zeroed out.  */
> +
> +static void
> +get_local_addresses (const struct addrinfo *req, struct gaih_result *res)
> +{
> +  struct gaih_addrtuple *atr = res->at;
> +  if (req->ai_family == AF_UNSPEC)
> +    res->at->next = res->at + 1;
> +
> +  if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
> +    {
> +      res->at->family = AF_INET6;
> +      if ((req->ai_flags & AI_PASSIVE) == 0)
> +	memcpy (res->at->addr, &in6addr_loopback, sizeof (struct in6_addr));
> +      atr = res->at->next;
> +    }
> +
> +  if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET)
> +    {
> +      atr->family = AF_INET;
> +      if ((req->ai_flags & AI_PASSIVE) == 0)
> +	atr->addr[0] = htonl (INADDR_LOOPBACK);
> +    }
> +}

Ok.

>  
> -  /* Reserve stack memory for the scratch buffer in the getaddrinfo
> -     function.  */
> -  size_t alloca_used = sizeof (struct scratch_buffer);
> -

Ok.

>    struct gaih_result res = {0};
> +  struct gaih_addrtuple local_at[2] = {0};
> +
> +  res.at = local_at;
> +
> +  if (__glibc_unlikely (name == NULL))
> -  if (name != NULL)
>      {
> +      get_local_addresses (req, &res);
> +      goto process_list;
> +    }
> +

Ok.

>  
> -      res.at = alloca_account (sizeof (struct gaih_addrtuple), alloca_used);
> -      res.at->scopeid = 0;
> -      res.at->next = NULL;

Ok.

> -  else
> -    {
> -      struct gaih_addrtuple *atr;
> -      atr = res.at = alloca_account (sizeof (struct gaih_addrtuple),
> -				     alloca_used);
> -      memset (res.at, '\0', sizeof (struct gaih_addrtuple));
> -
> -      if (req->ai_family == AF_UNSPEC)
> -	{
> -	  res.at->next = __alloca (sizeof (struct gaih_addrtuple));
> -	  memset (res.at->next, '\0', sizeof (struct gaih_addrtuple));
> -	}
> -
> -      if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
> -	{
> -	  res.at->family = AF_INET6;
> -	  if ((req->ai_flags & AI_PASSIVE) == 0)
> -	    memcpy (res.at->addr, &in6addr_loopback, sizeof (struct in6_addr));
> -	  atr = res.at->next;
> -	}
> -
> -      if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET)
> -	{
> -	  atr->family = AF_INET;
> -	  if ((req->ai_flags & AI_PASSIVE) == 0)
> -	    atr->addr[0] = htonl (INADDR_LOOPBACK);
> -	}
> -    }

Ok.