[PATCH] PR other/24689: Fix NetBSD bootstrap failure

[Roger Sayle <roger at eyesopen dot com>]

The following patch should resolve PR other/24689, which is a bootstrap
failure on NetBSD caused by NetBSD's pthread.h using #define to rename/map
pthread_once, pthread_self and other identifiers to alternate libc
symbols.  The use of the preprocessor conflicts with gthr-posix.h's
attempts to map __gthrw_pthread_once as a weak reference to pthread_once.

The fix below is to precisely control when these symbols get expanded
by the preprocessor, such that we declare __gthrw_pthread_once to have
the correct type, and alias the expanded symbol.  This required a
compensating change to the way that Tru64 maps symbols such as
__gthrw_pthread_once to __pthread_once.


The following code has been tested on alphaev67-dec-osf5.1 with a
full "make bootstrap", all default langauges, and regression tested
with a top-level "make -k check" with no new failures.  It's also
been reported by the bug submitter to fix things for him/her.

Now that the window for 4.1.0 has passed, there's no immediate rush
to get this onto the gcc-4_1-branch, so hopefully it'll get some
NetBSD testing on mainline (which has been broken for some time).

Ok for mainline?



2006-03-01  Roger Sayle  <roger@eyesopen.com>

	PR other/26489
	* gthr-posix.h (__gthrw2): Define to take three parameters, the
	declared name, the weak reference name, and the typeof name.
	(__gthrw): Avoid expanding the declared name suffix.
	(__gthrw3): New Tru64 specific macro to simplify the OSF/1 decls.


Index: gthr-posix.h
===================================================================
*** gthr-posix.h	(revision 111507)
--- gthr-posix.h	(working copy)
*************** typedef pthread_mutex_t __gthread_recurs
*** 59,88 ****
  #endif

  #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
! # define __gthrw2(name,name2) \
!   static __typeof(name) __gthrw_ ## name __attribute__ ((__weakref__(#name2)));
  # define __gthrw_(name) __gthrw_ ## name
  #else
! # define __gthrw2(name,name2)
  # define __gthrw_(name) name
  #endif

  /* Typically, __gthrw_foo is a weak reference to symbol foo.  */
! #define __gthrw(name) __gthrw2(name,name)

  /* On Tru64, /usr/include/pthread.h uses #pragma extern_prefix "__" to
     map a subset of the POSIX pthread API to mangled versions of their
     names.  */
  #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
! __gthrw2(pthread_once,__pthread_once)
! __gthrw2(pthread_getspecific,__pthread_getspecific)
! __gthrw2(pthread_setspecific,__pthread_setspecific)
! __gthrw2(pthread_create,__pthread_create)
! __gthrw2(pthread_cancel,__pthread_cancel)
! __gthrw2(pthread_mutex_lock,__pthread_mutex_lock)
! __gthrw2(pthread_mutex_trylock,__pthread_mutex_trylock)
! __gthrw2(pthread_mutex_unlock,__pthread_mutex_unlock)
! __gthrw2(pthread_mutex_init,__pthread_mutex_init)
  #else
  __gthrw(pthread_once)
  __gthrw(pthread_getspecific)
--- 59,89 ----
  #endif

  #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
! # define __gthrw2(name,name2,type) \
!   static __typeof(type) name __attribute__ ((__weakref__(#name2)));
  # define __gthrw_(name) __gthrw_ ## name
  #else
! # define __gthrw2(name,name2,type)
  # define __gthrw_(name) name
  #endif

  /* Typically, __gthrw_foo is a weak reference to symbol foo.  */
! #define __gthrw(name) __gthrw2(__gthrw_ ## name,name,name)

  /* On Tru64, /usr/include/pthread.h uses #pragma extern_prefix "__" to
     map a subset of the POSIX pthread API to mangled versions of their
     names.  */
  #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
! #define __gthrw3(name) __gthrw2(__gthrw_ ## name, __ ## name, name)
! __gthrw3(pthread_once)
! __gthrw3(pthread_getspecific)
! __gthrw3(pthread_setspecific)
! __gthrw3(pthread_create)
! __gthrw3(pthread_cancel)
! __gthrw3(pthread_mutex_lock)
! __gthrw3(pthread_mutex_trylock)
! __gthrw3(pthread_mutex_unlock)
! __gthrw3(pthread_mutex_init)
  #else
  __gthrw(pthread_once)
  __gthrw(pthread_getspecific)
*************** __gthrw(pthread_mutexattr_destroy)
*** 105,118 ****
  #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
  /* Objective-C.  */
  #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
! __gthrw2(pthread_cond_broadcast,__pthread_cond_broadcast)
! __gthrw2(pthread_cond_destroy,__pthread_cond_destroy)
! __gthrw2(pthread_cond_init,__pthread_cond_init)
! __gthrw2(pthread_cond_signal,__pthread_cond_signal)
! __gthrw2(pthread_cond_wait,__pthread_cond_wait)
! __gthrw2(pthread_exit,__pthread_exit)
! __gthrw2(pthread_mutex_destroy,__pthread_mutex_destroy)
! __gthrw2(pthread_self,__pthread_self)
  #else
  __gthrw(pthread_cond_broadcast)
  __gthrw(pthread_cond_destroy)
--- 106,119 ----
  #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
  /* Objective-C.  */
  #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
! __gthrw3(pthread_cond_broadcast)
! __gthrw3(pthread_cond_destroy)
! __gthrw3(pthread_cond_init)
! __gthrw3(pthread_cond_signal)
! __gthrw3(pthread_cond_wait)
! __gthrw3(pthread_exit)
! __gthrw3(pthread_mutex_destroy)
! __gthrw3(pthread_self)
  #else
  __gthrw(pthread_cond_broadcast)
  __gthrw(pthread_cond_destroy)


Roger
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