Re: [PATCH 15/30] nptl: Remove pread from libpthread

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

On 17/03/2021 16:33, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> diff --git a/sysdeps/unix/sysv/linux/alpha/pread64.c b/sysdeps/unix/sysv/linux/alpha/pread64.c
>> new file mode 100644
>> index 0000000000..a40e4447e1
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/alpha/pread64.c
>> @@ -0,0 +1,33 @@
>> +/* Read from to a file descriptor at a given offset.  Linux/alpha version.
>> +   Copyright (C) 2021 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <https://www.gnu.org/licenses/>.  */
>> +
>> +#define PREAD64_REQUIRE_PREAD_COMPAT
>> +#include <sysdeps/unix/sysv/linux/pread64.c>
>> +
>> +/* libpthread compat symbols.  */
>> +# if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_2)
>> +strong_alias (__libc_pread64, __compat_pread)
>> +compat_symbol (libc, __compat_pread, pread, GLIBC_2_1);
>> +
>> +strong_alias (__libc_pread64, __default_pread)
>> +versioned_symbol (libc, __default_pread, pread, GLIBC_2_2);
>> +
>> +/* It is a libc_hidden_def (__pread), but with a redirection due the symbol
>> +   versioning.  */
>> +__hidden_ver1 (__compat_pread, __GI___pread, __compat_pread);
>> +#endif
> 
> I believe this is libc_hidden_ver.  It took me a while to find it (see
> the original dance around ___libc_once).
> 
> This applies else where in this patch and also the pwrite patch.

Yes and I simplified the versioned and compat definitions a bit with
newer macros.