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Re: Removing internal symbols (Was: htl: Rename _pthread_mutex_init/destroy to __pthread_mutex_init/destroy)
On 27/01/2020 18:55, Samuel Thibault wrote:
> Hello,
>
> Expanding the subject a bit to catch more opinions on this:
>
> Samuel Thibault, le mar. 21 janv. 2020 22:28:50 +0100, a ecrit:
>> Adhemerval Zanella, le ven. 17 janv. 2020 17:40:09 -0300, a ecrit:
>>>> diff --git a/sysdeps/mach/hurd/i386/libpthread.abilist b/sysdeps/mach/hurd/i386/libpthread.abilist
>>>> index 0ede90859c..cda8755960 100644
>>>> --- a/sysdeps/mach/hurd/i386/libpthread.abilist
>>>> +++ b/sysdeps/mach/hurd/i386/libpthread.abilist
>>>> @@ -14,8 +14,6 @@ GLIBC_2.12 _cthread_init_routine D 0x4
>>>> GLIBC_2.12 _cthreads_flockfile F
>>>> GLIBC_2.12 _cthreads_ftrylockfile F
>>>> GLIBC_2.12 _cthreads_funlockfile F
>>>> -GLIBC_2.12 _pthread_mutex_destroy F
>>>> -GLIBC_2.12 _pthread_mutex_init F
>>>> GLIBC_2.12 _pthread_mutex_lock F
>>>> GLIBC_2.12 _pthread_mutex_trylock F
>>>> GLIBC_2.12 _pthread_mutex_unlock F
>>>
>>> I understand this change is follow Linux internal implementation
>>> and make mtx_init.c generic, but I don't think changing hurd
>>> libpthread exported symbols is the correct solution.
>>>
>>> Since the symbol won't be used anymore I think we can move to
>>> a compat symbol, something like:
>>>
>>> +strong_alias (__pthread_mutex_init, pthread_mutex_init);
>>> +hidden_def (__pthread_mutex_init)
>>> +#if SHLIB_COMPAT (libpthread, GLIBC_2_12, GLIBC_2_31)
>>> +compat_symbol (libpthread, __pthread_mutex_init, _pthread_mutex_init, GLIBC_2_12);
>>> +#endif
>>
>> But do we need to keep the compat symbols at all?
>>
>> _pthread_mutex_lock has never been exposed in a .h file, it should have
>> gotten version GLIBC_PRIVATE actually since it's only used between
>> libc.so and libpthread.so.
I think it might be fine in this case, assuming there is no external linkage
possible with header redirection. It is still a ABI break, but if an
application is using such symbol it is abusing the API.