On 1/4/19 10:36 PM, Pádraig Brady wrote:
> On 04/01/19 13:07, Bernhard Voelker wrote:
>> On 1/4/19 6:38 PM, Pádraig Brady wrote:
>>> I wonder should we avoid VLAs in coreutils altogether?
>>> I.E. add -Werror=vla. The kernel has done this for security reaons.
>>
>> Well, why not? The only problem is still the one mentioned in
>> 'configure.ac':
>>
>> nw="$nw -Wvla" # warnings in gettext.h
>>
>> With -Werror=vla, we get a lot of warnings, but all originate from
>> these 2 places in gettext.h:
>>
>> ./lib/gettext.h: In function 'dcpgettext_expr':
>> ./lib/gettext.h:220:3: error: ISO C90 forbids variable length array
>> 'msg_ctxt_id' [-Werror=vla]
>> char msg_ctxt_id[msgctxt_len + msgid_len];
>> ^~~~
>> ./lib/gettext.h: In function 'dcnpgettext_expr':
>> ./lib/gettext.h:268:3: error: ISO C90 forbids variable length array
>> 'msg_ctxt_id' [-Werror=vla]
>> char msg_ctxt_id[msgctxt_len + msgid_len];
>> ^~~~
>
> It should be sufficient to also
>
> #define __STDC_NO_VLA__ 1
>
No, that is inactive in gettext.h;
#if (((__GNUC__ >= 3 || __GNUG__ >= 2) && !defined __STRICT_ANSI__) \
/* || (__STDC_VERSION__ == 199901L && !defined __HP_cc)
|| (__STDC_VERSION__ >= 201112L && !defined __STDC_NO_VLA__) */ )
# define _LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS 1
#else
# define _LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS 0
#endif
See Bruno's comment in gnulib commit a750b78e69:
* lib/gettext.h (_LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS): Extend comment
to include the theoretical condition for availability of variable size
arrays, if we could trust the value of __STDC_VERSION__.
Have a nice day,
Berny
