Re: [Xenomai-core] [PATCH] posix: Avoid double declarations

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Jan Kiszka wrote:
> Gilles Chanteperdrix wrote:
>> Jan Kiszka wrote:
>>> Please pull from git://git.xenomai.org/xenomai-jki.git for-upstream
>>> and run bootstrap.
>>>
>>> ---------->
>>>
>>> Recent glibc versions come with support for
>>> pthread_mutexattr_get/setprotocol and pthread_condattr_get/setclock.
>>> Make sure we don't declare those prototypes in Xenomai's pthread.h a
>>> second time as this can cause g++ warnings and even errors.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>>> ---
>>>
>>>  configure.in            |    4 ++--
>>>  include/posix/pthread.h |    4 ++++
>>>  2 files changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/configure.in b/configure.in
>>> index b291ce4..6a8b821 100644
>>> --- a/configure.in
>>> +++ b/configure.in
>>> @@ -750,8 +750,8 @@ if test x$CONFIG_XENO_POSIX_UITRON_MLOCKALL = xy; then
>>>  fi
>>>  
>>>  save_LIBS="$LIBS"
>>> -LIBS="$LIBS -lrt"
>>> -AC_CHECK_FUNCS([shm_open shm_unlink mmap64 ftruncate64])
>>> +LIBS="$LIBS -lrt -lpthread"
>>> +AC_CHECK_FUNCS([shm_open shm_unlink mmap64 ftruncate64 pthread_mutexattr_setprotocol pthread_condattr_setclock])
>>>  LIBS="$save_LIBS"
>>>  
>>>  AC_MSG_CHECKING(whether to enable dlopen support for skin libraries)
>>> diff --git a/include/posix/pthread.h b/include/posix/pthread.h
>>> index 2344158..98db325 100644
>>> --- a/include/posix/pthread.h
>>> +++ b/include/posix/pthread.h
>>> @@ -418,17 +418,21 @@ int pthread_intr_control_np(pthread_intr_t intr,
>>>  extern "C" {
>>>  #endif
>>>  
>>> +#ifndef HAVE_PTHREAD_MUTEXATTR_SETPROTOCOL
>>>  int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *attr,
>>>  				  int *proto);
>>>  
>>>  int pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr,
>>>  				  int proto);
>>> +#endif
>> That is not enough, if these functions are defined, then the
>> PTHREAD_PRIO_NONE, PTHREAD_PRIO_INHERIT, PTHREAD_PRIO_PROTECT are going
>> to be defined.
>>
>> Are you sure that the missing "restrict" are not causing the errors ?
> 
> This is enough to fix our build breakage due to different prototypes of
> those functions, at least under C++. The magic __THROW may make the
> difference, but I didn't test that in details as I think its simply
> fragile to redeclare them.
> 
> Don't know if those constants can cause trouble, they didn't do so here
> so far. But I can Include them if preferred.

If it works, it is just as fragile as trying to match function
declarations of Xenomai's pthread.h and glibc's pthread.h.

-- 
                                                 Gilles.