[PATCH] D12747: Implement [depr.c.headers]

[Eric Fiselier via cfe-commits]

Patch #14 LGTM modulo pragmas.

On Thu, Oct 8, 2015 at 7:39 PM, Eric Fiselier <eric at efcs.ca> wrote:
> Patch #13 LGTM after revision.
>
> a system header pragma needs to be added to the __need_wint_t path of wchar.h.
> The existing pragma also needs fixing as previously discussed.
>
> On Thu, Oct 8, 2015 at 7:25 PM, Eric Fiselier <eric at efcs.ca> wrote:
>> Patch #12 needs revision. A bunch of function definitions were moved
>> out of the std namespace and into the global.
>> That change is incorrect.
>>
>>
>>
>> On Thu, Oct 8, 2015 at 7:09 PM, Eric Fiselier <eric at efcs.ca> wrote:
>>> Patch #11 LGTM. Any reason you removed the "#pragma diagnostic ignored
>>> "-Wnonnull"" in test/std/depr/depr.c.headers/stdlib_h.pass.cpp?
>>> I would like to leave it in so this test doesn't fail with older clang
>>> versions.
>>>
>>> /Eric
>>>
>>> On Thu, Oct 8, 2015 at 6:47 PM, Eric Fiselier <eric at efcs.ca> wrote:
>>>> Patch #10 LGTM.
>>>>
>>>> On Thu, Oct 8, 2015 at 4:28 PM, Richard Smith <richard at metafoo.co.uk> wrote:
>>>>> On Thu, Oct 8, 2015 at 11:50 AM, Marshall Clow <mclow.lists at gmail.com>
>>>>> wrote:
>>>>>>
>>>>>> On Tue, Oct 6, 2015 at 3:57 PM, Richard Smith <richard at metafoo.co.uk>
>>>>>> wrote:
>>>>>>>
>>>>>>> <stddef.h>. This one is tricky:
>>>>>>>
>>>>>>> 1) There's an (undocumented) interface between the C standard library and
>>>>>>> this header, where the macros __need_ptrdiff_t, __need_size_t,
>>>>>>> __need_wchar_t, __need_NULL, __need_wint_t request just a piece of this
>>>>>>> header rather than the whole thing. If we see any of those, just go straight
>>>>>>> to the underlying header.
>>>>>>
>>>>>>
>>>>>> Ok, but in that case we don't get nullptr.  I suspect that's OK.
>>>>>>
>>>>>>>
>>>>>>> 2) We probably don't want <stddef.h> to include <cstddef> (for
>>>>>>> consistency with other headers)
>>>>>>
>>>>>>
>>>>>> No, we do not! :-)
>>>>>>
>>>>>>>
>>>>>>> , but <stddef.h> must provide a ::nullptr_t (which we don't want
>>>>>>> <cstddef> to provide). So neither header includes the other. Instead, both
>>>>>>> include <__nullptr> for std::nullptr_t, and we duplicate the definition of
>>>>>>> max_align_t between them, in the case where the compiler's <stddef.h>
>>>>>>> doesn't provide it.
>>>>>>>
>>>>>>> If you prefer, I could make <stddef.h> include <cstddef> to avoid the
>>>>>>> duplication of the max_align_t logic.
>>>>>>
>>>>>>
>>>>>> No; this is a minor annoyance, and layer jumping (<stdXXX.h> including
>>>>>> <cstdXXX>) is a major annoyance - and I'm pretty sure that that would come
>>>>>> back to bite us in the future.
>>>>>>
>>>>>> Looks ok to me.
>>>>>
>>>>>
>>>>> Thanks, everything up to and including patch 09 is now committed.