Re: [PATCH 01/18] nptl: Move pthread_mutex_consistent into libc

[Florian Weimer <fweimer@redhat.com>]

* Adhemerval Zanella:

>> index 937c7c4640..0a84063a2b 100644
>> --- a/nptl/pthread_mutex_consistent.c
>> +++ b/nptl/pthread_mutex_consistent.c
>> @@ -18,10 +18,10 @@
>>  
>>  #include <errno.h>
>>  #include <pthreadP.h>
>> -
>> +#include <shlib-compat.h>
>>  
>>  int
>> -pthread_mutex_consistent (pthread_mutex_t *mutex)
>> +__pthread_mutex_consistent (pthread_mutex_t *mutex)
>>  {
>>    /* Test whether this is a robust mutex with a dead owner.
>>       See concurrency notes regarding __kind in struct __pthread_mutex_s
>> @@ -35,4 +35,20 @@ pthread_mutex_consistent (pthread_mutex_t *mutex)
>>  
>>    return 0;
>>  }
>> -weak_alias (pthread_mutex_consistent, pthread_mutex_consistent_np)
>> +versioned_symbol (libc, __pthread_mutex_consistent, pthread_mutex_consistent,
>> +                  GLIBC_2_34);
>> +
>> +#if SHLIB_COMPAT (libc, GLIBC_2_4, GLIBC_2_34)
>
> Shouldn't be GLIBC_2_12 here?

Where exactly?  There are so many symbol versions.  The _np variant was
introduced in GLIBC_2.4, so GLIBC_2_4 is correct here.  It ran parallel
with the non-_np variant until GLIBC_2.34, so that's the end range.

>> +/* Compat symbol with the old libc version, _np alias.  */
>> +# undef pthread_mutex_consistent_np
>
> I think should be out of SHLIB_COMPAT.

It will go away if I switch to __REDIRECT.

>> +strong_alias (__pthread_mutex_consistent, __pthread_mutex_consistent_1)
>> +compat_symbol (libc, __pthread_mutex_consistent_1,
>> +               pthread_mutex_consistent_np, GLIBC_2_4);
>> +#endif
>> +
>> +#if SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_34)
>> +/* Compat symbol with the old libc version.  */
>> +strong_alias (__pthread_mutex_consistent, __pthread_mutex_consistent_2)
>> +compat_symbol (libc, __pthread_mutex_consistent_2,
>> +               pthread_mutex_consistent, GLIBC_2_12);
>> +#endif
>
> I think we have compat_symbol_unique exactly for that.

It doesn't apply here because the symbol names are different
(__pthread_mutex_consistent vs pthread_mutex_consistent):

# define compat_symbol_unique(lib, name, version) \

The macro has just one name argument.

>> diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h
>> index a04a3a2754..2ec2caec98 100644
>> --- a/sysdeps/nptl/pthread.h
>> +++ b/sysdeps/nptl/pthread.h
>> @@ -809,8 +809,9 @@ extern int pthread_mutex_setprioceiling (pthread_mutex_t *__restrict __mutex,
>>  extern int pthread_mutex_consistent (pthread_mutex_t *__mutex)
>>       __THROW __nonnull ((1));
>>  # ifdef __USE_GNU
>> -extern int pthread_mutex_consistent_np (pthread_mutex_t *__mutex)
>> -     __THROW __nonnull ((1));
>> +#  define pthread_mutex_consistent_np __glibc_macro_warning ("\
>> +pthread_mutex_consistent_np is deprecated, use pthread_mutex_consistent") \
>> +  pthread_mutex_consistent
>>  # endif
>>  #endif
>>  
>
> Wouldn't be better to throw a link error instead an empty macro for such
> case?

It's not an empty macro, there's a third line.  I can see if I can use
__REDIRECT instead if that's clearer.

Thanks,
Florian