On Mon, Feb 15, 2016 at 03:05:36PM +0100, Marek Polacek wrote:
> On Sat, Feb 13, 2016 at 03:16:49AM +0000, Stuart Brady wrote:
> > I will look into submitting a PR for this properly soon, but will not
> > mind if someone wants to take this task upon themselves instead,
> > especially as we are into the release phase for GCC 6 and this may be
> > an issue worth fixing. (Note that Debian's GCC 5.3.1 is also affected.)
>
> Sure, I've just filed this:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69824
Thank you!
> > For a hypothetical change to the C standard itself, I think one might use
> > the name "_ArraySize", but for a non-standard extension this would not be
> > appropriate. I think "__array_size" is fine, though, and is consistent
> > with "__alignof".
>
> Please no CamelCase, that's ugly ;). I also think that "__array_size" is
> fine.
Okay. I was wondering about __arraysize, __array_len, or some such
thing but I suppose one just needs to pick something. ARRAY_SIZE seems
common as macro name that I find __array_size to be immediately obvious.
Certainly, the name is something that doesn't need to be decided just now
although it's better to consider alternatives sooner rather than later.
Hypothetically, I suppose _Array_Size, _Array_size or _Arraysize would
all be better than the CamelCase verison.
> (I haven't had time so far to read the patch.)
Jospeh's point that documentation and testcases are of much more value is
good one, and reveals a problem with my patch. It does not work in the
following case:
vla-array-size.c:19:55: error: invalid use of flexible array member
int foo6(int a, int b[*][*], int c[static __array_size(*b)]);
^
sizeof() *does* work in this case -- my test is based on gcc.dg/vla-5.c
which uses sizeof() instead. __array_size(*b) works fine the function
body but not in the prototype, and also works fine with C99 variable
length arrays.
This message has been borrowed from c_incomplete_type_error(), along with
the test for TYPE_DOMAIN (type) && TYPE_MAX_VALUE (TYPE_DOMAIN (type)).
Unfortunately, I'm at a loss to say whether TYPE_MAX_VALUE should be
set in this instance, or whether I should be going about things
differently. It seems interesting that TYPE_SIZE_UNIT (type) is set
but TYPE_MAX_VALUE (TYPE_DOMAIN (type)) is not. Can anyone help?
Also, it's not obvious to me whether I need to consider the case of
TYPE_MIN_VALUE (TYPE_DOMAIN (type)) being nonzero.
--
Many thanks,
Stuart Brady
