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

[Eric Fiselier via cfe-commits]

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.