Re: [PATCH 02/11] Disable __USE_EXTERN_INLINES for clang

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 28/10/22 19:02, Fangrui Song wrote:
> On 2022-10-28, Joseph Myers wrote:
>> On Fri, 28 Oct 2022, Adhemerval Zanella via Libc-alpha wrote:
>>
>>> From: Fangrui Song <maskray@google.com>
>>>
>>> clang does not allow to redefine attributes after function declaration.
>>> Although it work for external usage, its breaks the build for internal
>>> symbol that glibc provides as optimization (for instance bsearch with
>>> stdlib-bsearch.h or __cmsg_nxthdr).
>>
>> If it works for external usage, I'd expect the disabling to be only when
>> _LIBC is defined and not for building normal applications using this
>> installed header file.
> 
> Thanks for mentioning _LIBC (I did not know).  Then it looks like we can use this:
> 
> /* Decide whether we can define 'extern inline' functions in headers.  */
> #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
>     && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
>     && defined __extern_inline && !(defined __clang__ && defined _LIBC)
> # define __USE_EXTERN_INLINES   1
> #endif
> 
> https://sourceware.org/git/?p=glibc.git;a=shortlog;h=refs/heads/azanella/clang builds with this change.

Right, I will check and resend it.