From: Samuel Thibault <samuel.thibault@gnu.org>
To: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org,
Jonathan Wakely <jwakely@redhat.com>
Cc: bug-hurd@gnu.org
Subject: [PATCHv2] libstdc++: Mark pieces of gnu-linux/os_support.h linux-specific
Date: Fri, 7 Oct 2022 22:45:06 +0200 [thread overview]
Message-ID: <20221007204506.cokw3lkkn5aequ5h@begin> (raw)
This is notably needed because in glibc 2.34, the move of pthread functions
into libc.so happened for Linux only, not GNU/Hurd.
The pthread_self() function can also always be used fine as it is on
GNU/Hurd.
libstdc++-v3/ChangeLog:
* config/os/gnu-linux/os_defines.h [!__linux__]
(_GLIBCXX_NATIVE_THREAD_ID, _GLIBCXX_GTHREAD_USE_WEAK): Do not define.
diff --git a/libstdc++-v3/config/os/gnu-linux/os_defines.h b/libstdc++-v3/config/os/gnu-linux/os_defines.h
index c0caa21a013..4de93d752e1 100644
--- a/libstdc++-v3/config/os/gnu-linux/os_defines.h
+++ b/libstdc++-v3/config/os/gnu-linux/os_defines.h
@@ -49,22 +49,24 @@
// version dynamically in case it has changed since libstdc++ was configured.
#define _GLIBCXX_NO_OBSOLETE_ISINF_ISNAN_DYNAMIC __GLIBC_PREREQ(2,23)
-#if __GLIBC_PREREQ(2, 27)
-// Since glibc 2.27 pthread_self() is usable without linking to libpthread.
-# define _GLIBCXX_NATIVE_THREAD_ID pthread_self()
-#else
+#ifdef __linux__
+# if __GLIBC_PREREQ(2, 27)
+// Since glibc 2.27 Linux' pthread_self() is usable without linking to libpthread.
+# define _GLIBCXX_NATIVE_THREAD_ID pthread_self()
+# else
// Before then it was in libc.so.6 but not libc.a, and always returns 0,
// which breaks the invariant this_thread::get_id() != thread::id{}.
// So only use it if we know the libpthread version is available.
// Otherwise use (__gthread_t)1 as the ID of the main (and only) thread.
-# define _GLIBCXX_NATIVE_THREAD_ID \
- (__gthread_active_p() ? __gthread_self() : (__gthread_t)1)
-#endif
+# define _GLIBCXX_NATIVE_THREAD_ID \
+ (__gthread_active_p() ? __gthread_self() : (__gthread_t)1)
+# endif
-#if __GLIBC_PREREQ(2, 34)
-// Since glibc 2.34 all pthreads functions are usable without linking to
+# if __GLIBC_PREREQ(2, 34)
+// Since glibc 2.34 all Linux pthreads functions are usable without linking to
// libpthread.
-# define _GLIBCXX_GTHREAD_USE_WEAK 0
+# define _GLIBCXX_GTHREAD_USE_WEAK 0
+# endif
#endif
#endif
next reply other threads:[~2022-10-07 20:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-07 20:45 Samuel Thibault [this message]
2023-02-03 12:36 ` Jonathan Wakely
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