gcc/libgcc/gthr-single.h
Nathaniel Shead 6a4d1c374e libgcc, libstdc++: Make declarations no longer TU-local [PR115126]
In C++20, modules streaming check for exposures of TU-local entities.
In general exposing internal linkage functions in a header is liable to
cause ODR violations in C++, and this is now detected in a module
context.

This patch goes through and removes 'static' from many declarations
exposed through libstdc++ to prevent code like the following from
failing:

  export module M;
  extern "C++" {
    #include <bits/stdc++.h>
  }

Since gthreads is used from C as well, we need to choose whether to use
'inline' or 'static inline' depending on whether we're compiling for C
or C++ (since the semantics of 'inline' are different between the
languages).  Additionally we need to remove static global variables, so
we migrate these to function-local statics to avoid the ODR issues.

There doesn't seem to be a good workaround for weakrefs, so I've left
them as-is and will work around it in the modules streaming code to
consider them as not TU-local.

The same issue occurs in the objective-C specific parts of gthreads, but
I'm not familiar with the surrounding context and we don't currently
test modules with Objective C++ anyway so I've left it as-is.

	PR libstdc++/115126

libgcc/ChangeLog:

	* gthr-posix.h (__GTHREAD_ALWAYS_INLINE): New macro.
	(__GTHREAD_INLINE): New macro.
	(__gthread_active): Convert from variable to (hidden) function.
	(__gthread_active_p): Mark as __GTHREAD_INLINE instead of
	static; make visibility("hidden") when it has a static local
	variable.
	(__gthread_trigger): Mark as __GTHREAD_INLINE instead of static.
	(__gthread_create): Likewise.
	(__gthread_join): Likewise.
	(__gthread_detach): Likewise.
	(__gthread_equal): Likewise.
	(__gthread_self): Likewise.
	(__gthread_yield): Likewise.
	(__gthread_once): Likewise.
	(__gthread_key_create): Likewise.
	(__gthread_key_delete): Likewise.
	(__gthread_getspecific): Likewise.
	(__gthread_setspecific): Likewise.
	(__gthread_mutex_init_function): Likewise.
	(__gthread_mutex_destroy): Likewise.
	(__gthread_mutex_lock): Likewise.
	(__gthread_mutex_trylock): Likewise.
	(__gthread_mutex_timedlock): Likewise.
	(__gthread_mutex_unlock): Likewise.
	(__gthread_recursive_mutex_init_function): Likewise.
	(__gthread_recursive_mutex_lock): Likewise.
	(__gthread_recursive_mutex_trylock): Likewise.
	(__gthread_recursive_mutex_timedlock): Likewise.
	(__gthread_recursive_mutex_unlock): Likewise.
	(__gthread_recursive_mutex_destroy): Likewise.
	(__gthread_cond_init_function): Likewise.
	(__gthread_cond_broadcast): Likewise.
	(__gthread_cond_signal): Likewise.
	(__gthread_cond_wait): Likewise.
	(__gthread_cond_timedwait): Likewise.
	(__gthread_cond_wait_recursive): Likewise.
	(__gthread_cond_destroy): Likewise.
	(__gthread_rwlock_rdlock): Likewise.
	(__gthread_rwlock_tryrdlock): Likewise.
	(__gthread_rwlock_wrlock): Likewise.
	(__gthread_rwlock_trywrlock): Likewise.
	(__gthread_rwlock_unlock): Likewise.
	* gthr-single.h: (__GTHREAD_ALWAYS_INLINE): New macro.
	(__GTHREAD_INLINE): New macro.
	(__gthread_active_p): Mark as __GTHREAD_INLINE instead of static.
	(__gthread_once): Likewise.
	(__gthread_key_create): Likewise.
	(__gthread_key_delete): Likewise.
	(__gthread_getspecific): Likewise.
	(__gthread_setspecific): Likewise.
	(__gthread_mutex_destroy): Likewise.
	(__gthread_mutex_lock): Likewise.
	(__gthread_mutex_trylock): Likewise.
	(__gthread_mutex_unlock): Likewise.
	(__gthread_recursive_mutex_lock): Likewise.
	(__gthread_recursive_mutex_trylock): Likewise.
	(__gthread_recursive_mutex_unlock): Likewise.
	(__gthread_recursive_mutex_destroy): Likewise.

libstdc++-v3/ChangeLog:

	* include/bits/shared_ptr.h (std::__is_shared_ptr): Remove
	unnecessary 'static'.
	* include/bits/unique_ptr.h (std::__is_unique_ptr): Likewise.
	* include/std/future (std::__create_task_state): Likewise.
	* include/std/shared_mutex (_GLIBCXX_GTRHW): Likewise.
	(__glibcxx_rwlock_init): Likewise.
	(__glibcxx_rwlock_timedrdlock): Likewise.
	(__glibcxx_rwlock_timedwrlock): Likewise.
	(__glibcxx_rwlock_rdlock): Likewise.
	(__glibcxx_rwlock_tryrdlock): Likewise.
	(__glibcxx_rwlock_wrlock): Likewise.
	(__glibcxx_rwlock_trywrlock): Likewise.
	(__glibcxx_rwlock_unlock): Likewise.
	(__glibcxx_rwlock_destroy): Likewise.
	(__glibcxx_rwlock_init): Likewise.
	* include/pstl/algorithm_impl.h
	(__pstl::__internal::__set_algo_cut_off): Mark inline.
	* include/pstl/unseq_backend_simd.h
	(__pstl::__unseq_backend::__lane_size): Mark inline.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Reviewed-by: Jakub Jelinek <jakub@redhat.com>
2024-09-27 09:16:53 +10:00

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6.8 KiB
C

/* Threads compatibility routines for libgcc2 and libobjc. */
/* Compile this one with gcc. */
/* Copyright (C) 1997-2024 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef GCC_GTHR_SINGLE_H
#define GCC_GTHR_SINGLE_H
/* Just provide compatibility for mutex handling. */
typedef int __gthread_key_t;
typedef int __gthread_once_t;
typedef int __gthread_mutex_t;
typedef int __gthread_recursive_mutex_t;
#define __GTHREAD_ONCE_INIT 0
#define __GTHREAD_MUTEX_INIT 0
#define __GTHREAD_MUTEX_INIT_FUNCTION(mx) do {} while (0)
#define __GTHREAD_RECURSIVE_MUTEX_INIT 0
#ifdef __has_attribute
# if __has_attribute(__always_inline__)
# define __GTHREAD_ALWAYS_INLINE __attribute__((__always_inline__))
# endif
#endif
#ifndef __GTHREAD_ALWAYS_INLINE
# define __GTHREAD_ALWAYS_INLINE
#endif
#ifdef __cplusplus
# define __GTHREAD_INLINE inline __GTHREAD_ALWAYS_INLINE
#else
# define __GTHREAD_INLINE static inline
#endif
#define UNUSED __attribute__((__unused__))
#ifdef _LIBOBJC
/* Thread local storage for a single thread */
static void *thread_local_storage = NULL;
/* Backend initialization functions */
/* Initialize the threads subsystem. */
static inline int
__gthread_objc_init_thread_system (void)
{
/* No thread support available */
return -1;
}
/* Close the threads subsystem. */
static inline int
__gthread_objc_close_thread_system (void)
{
/* No thread support available */
return -1;
}
/* Backend thread functions */
/* Create a new thread of execution. */
static inline objc_thread_t
__gthread_objc_thread_detach (void (* func)(void *), void * arg UNUSED)
{
/* No thread support available */
return NULL;
}
/* Set the current thread's priority. */
static inline int
__gthread_objc_thread_set_priority (int priority UNUSED)
{
/* No thread support available */
return -1;
}
/* Return the current thread's priority. */
static inline int
__gthread_objc_thread_get_priority (void)
{
return OBJC_THREAD_INTERACTIVE_PRIORITY;
}
/* Yield our process time to another thread. */
static inline void
__gthread_objc_thread_yield (void)
{
return;
}
/* Terminate the current thread. */
static inline int
__gthread_objc_thread_exit (void)
{
/* No thread support available */
/* Should we really exit the program */
/* exit (&__objc_thread_exit_status); */
return -1;
}
/* Returns an integer value which uniquely describes a thread. */
static inline objc_thread_t
__gthread_objc_thread_id (void)
{
/* No thread support, use 1. */
return (objc_thread_t) 1;
}
/* Sets the thread's local storage pointer. */
static inline int
__gthread_objc_thread_set_data (void *value)
{
thread_local_storage = value;
return 0;
}
/* Returns the thread's local storage pointer. */
static inline void *
__gthread_objc_thread_get_data (void)
{
return thread_local_storage;
}
/* Backend mutex functions */
/* Allocate a mutex. */
static inline int
__gthread_objc_mutex_allocate (objc_mutex_t mutex UNUSED)
{
return 0;
}
/* Deallocate a mutex. */
static inline int
__gthread_objc_mutex_deallocate (objc_mutex_t mutex UNUSED)
{
return 0;
}
/* Grab a lock on a mutex. */
static inline int
__gthread_objc_mutex_lock (objc_mutex_t mutex UNUSED)
{
/* There can only be one thread, so we always get the lock */
return 0;
}
/* Try to grab a lock on a mutex. */
static inline int
__gthread_objc_mutex_trylock (objc_mutex_t mutex UNUSED)
{
/* There can only be one thread, so we always get the lock */
return 0;
}
/* Unlock the mutex */
static inline int
__gthread_objc_mutex_unlock (objc_mutex_t mutex UNUSED)
{
return 0;
}
/* Backend condition mutex functions */
/* Allocate a condition. */
static inline int
__gthread_objc_condition_allocate (objc_condition_t condition UNUSED)
{
return 0;
}
/* Deallocate a condition. */
static inline int
__gthread_objc_condition_deallocate (objc_condition_t condition UNUSED)
{
return 0;
}
/* Wait on the condition */
static inline int
__gthread_objc_condition_wait (objc_condition_t condition UNUSED,
objc_mutex_t mutex UNUSED)
{
return 0;
}
/* Wake up all threads waiting on this condition. */
static inline int
__gthread_objc_condition_broadcast (objc_condition_t condition UNUSED)
{
return 0;
}
/* Wake up one thread waiting on this condition. */
static inline int
__gthread_objc_condition_signal (objc_condition_t condition UNUSED)
{
return 0;
}
#else /* _LIBOBJC */
__GTHREAD_INLINE int
__gthread_active_p (void)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_once (__gthread_once_t *__once UNUSED, void (*__func) (void) UNUSED)
{
return 0;
}
__GTHREAD_INLINE int UNUSED
__gthread_key_create (__gthread_key_t *__key UNUSED, void (*__func) (void *) UNUSED)
{
return 0;
}
__GTHREAD_INLINE int UNUSED
__gthread_key_delete (__gthread_key_t __key UNUSED)
{
return 0;
}
__GTHREAD_INLINE void *
__gthread_getspecific (__gthread_key_t __key UNUSED)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_setspecific (__gthread_key_t __key UNUSED, const void *__v UNUSED)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_mutex_destroy (__gthread_mutex_t *__mutex UNUSED)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_mutex_lock (__gthread_mutex_t *__mutex UNUSED)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_mutex_trylock (__gthread_mutex_t *__mutex UNUSED)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_mutex_unlock (__gthread_mutex_t *__mutex UNUSED)
{
return 0;
}
__GTHREAD_INLINE int
__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *__mutex)
{
return __gthread_mutex_lock (__mutex);
}
__GTHREAD_INLINE int
__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *__mutex)
{
return __gthread_mutex_trylock (__mutex);
}
__GTHREAD_INLINE int
__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
{
return __gthread_mutex_unlock (__mutex);
}
__GTHREAD_INLINE int
__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
{
return __gthread_mutex_destroy (__mutex);
}
#endif /* _LIBOBJC */
#undef UNUSED
#undef __GTHREAD_INLINE
#undef __GTHREAD_ALWAYS_INLINE
#endif /* ! GCC_GTHR_SINGLE_H */