[PATCH] check_native: Get rid of alloca

[Andreas Schwab]

On Jun 01 2023, Florian Weimer via Libc-alpha wrote:

> * Adhemerval Zanella Netto via Libc-alpha:
>
>> +static void
>> +iclose (int *fd)
>> +{
>> +  if (*fd >= 0)
>> +    __close_nocancel_nostatus (*fd);
>> +}
>> +
>>  void
>>  __check_native (uint32_t a1_index, int *a1_native,
>>  		uint32_t a2_index, int *a2_native)
>>  {
>> -  int fd = __socket (PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
>> +  int __attribute__ ((__cleanup__ (iclose))) fd
>> +    = __socket (PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
>> +  if (fd < 0)
>> +    return;
>
> I think introducing attribute cleanup where equivalent functionality can
> be implemented otherwise requires a discussion first.

The cleanup attribute requires compiling the function and all callees
with -fasynchronous-unwind-tables.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
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