[PATCH][BZ 18234] struct stat is not posix conform

[Carlos O'Donell]

On 05/20/2015 11:20 AM, Szabolcs Nagy wrote:
> the generic definition of struct stat on linux miss the
> st_atim, st_mtim and st_ctim members when _POSIX_C_SOURCE
> is defined (affects at least aarch64 and arm).
> 
> i did not see regressions on aarch64.
> 
> 2015-05-20  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	[BZ #18234]
> 	* sysdeps/unix/sysv/linux/generic/bits/stat.h (struct stat): Make
> 	st_atim, st_ctim, st_mtim visible under __USE_XOPEN2K8.

I like the idea of the change.

Firstly it needs a test case.

Secondly, it changes when these members are made available, and that
might break applications unless you show that __USE_MISC is a subset
of __USE_XOPEN2K8, which I don't think it is.

Therefore you will have to use "__USE_MISC || __USE_XOPEN2K8" preceeded
by a lengthy comment about the fact that in _DEFAULT_SOURCE you'll get
these members, but in strict compliance you need to have POSIX Issue 7.
 
Joseph, does that sound right to you?

> diff --git a/sysdeps/unix/sysv/linux/generic/bits/stat.h b/sysdeps/unix/sysv/linux/generic/bits/stat.h
> index 42cb198..82e6b1d 100644
> --- a/sysdeps/unix/sysv/linux/generic/bits/stat.h
> +++ b/sysdeps/unix/sysv/linux/generic/bits/stat.h
> @@ -66,7 +66,7 @@ struct stat
>      __blksize_t st_blksize;	/* Optimal block size for I/O.  */
>      int __pad2;
>      __field64(__blkcnt_t, __blkcnt64_t, st_blocks);  /* 512-byte blocks */
> -#ifdef __USE_MISC
> +#ifdef __USE_XOPEN2K8
>      /* Nanosecond resolution timestamps are stored in a format
>         equivalent to 'struct timespec'.  This is the type used
>         whenever possible but the Unix namespace rules do not allow the

Cheers,
Carlos.