| 1 | // Specific definitions for GNU/Linux -*- C++ -*- |
| 2 | |
| 3 | // Copyright (C) 2000-2021 Free Software Foundation, Inc. |
| 4 | // |
| 5 | // This file is part of the GNU ISO C++ Library. This library is free |
| 6 | // software; you can redistribute it and/or modify it under the |
| 7 | // terms of the GNU General Public License as published by the |
| 8 | // Free Software Foundation; either version 3, or (at your option) |
| 9 | // any later version. |
| 10 | |
| 11 | // This library is distributed in the hope that it will be useful, |
| 12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | // GNU General Public License for more details. |
| 15 | |
| 16 | // Under Section 7 of GPL version 3, you are granted additional |
| 17 | // permissions described in the GCC Runtime Library Exception, version |
| 18 | // 3.1, as published by the Free Software Foundation. |
| 19 | |
| 20 | // You should have received a copy of the GNU General Public License and |
| 21 | // a copy of the GCC Runtime Library Exception along with this program; |
| 22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| 23 | // <http://www.gnu.org/licenses/>. |
| 24 | |
| 25 | /** @file bits/os_defines.h |
| 26 | * This is an internal header file, included by other library headers. |
| 27 | * Do not attempt to use it directly. @headername{iosfwd} |
| 28 | */ |
| 29 | |
| 30 | #ifndef _GLIBCXX_OS_DEFINES |
| 31 | #define _GLIBCXX_OS_DEFINES 1 |
| 32 | |
| 33 | // System-specific #define, typedefs, corrections, etc, go here. This |
| 34 | // file will come before all others. |
| 35 | |
| 36 | // This keeps isanum, et al from being propagated as macros. |
| 37 | #define __NO_CTYPE 1 |
| 38 | |
| 39 | #include <features.h> |
| 40 | |
| 41 | // Provide a declaration for the possibly deprecated gets function, as |
| 42 | // glibc 2.15 and later does not declare gets for ISO C11 when |
| 43 | // __GNU_SOURCE is defined. |
| 44 | #if __GLIBC_PREREQ(2,15) && defined(_GNU_SOURCE) |
| 45 | # undef _GLIBCXX_HAVE_GETS |
| 46 | #endif |
| 47 | |
| 48 | // Glibc 2.23 removed the obsolete isinf and isnan declarations. Check the |
| 49 | // version dynamically in case it has changed since libstdc++ was configured. |
| 50 | #define _GLIBCXX_NO_OBSOLETE_ISINF_ISNAN_DYNAMIC __GLIBC_PREREQ(2,23) |
| 51 | |
| 52 | #ifdef __linux__ |
| 53 | # if __GLIBC_PREREQ(2, 27) |
| 54 | // Since glibc 2.27 Linux' pthread_self() is usable without linking to libpthread. |
| 55 | # define _GLIBCXX_NATIVE_THREAD_ID pthread_self() |
| 56 | # else |
| 57 | // Before then it was in libc.so.6 but not libc.a, and always returns 0, |
| 58 | // which breaks the invariant this_thread::get_id() != thread::id{}. |
| 59 | // So only use it if we know the libpthread version is available. |
| 60 | // Otherwise use (__gthread_t)1 as the ID of the main (and only) thread. |
| 61 | # define _GLIBCXX_NATIVE_THREAD_ID \ |
| 62 | (__gthread_active_p() ? __gthread_self() : (__gthread_t)1) |
| 63 | # endif |
| 64 | |
| 65 | # if __GLIBC_PREREQ(2, 34) |
| 66 | // Since glibc 2.34 all Linux pthreads functions are usable without linking to |
| 67 | // libpthread. |
| 68 | # define _GLIBCXX_GTHREAD_USE_WEAK 0 |
| 69 | # endif |
| 70 | #endif |
| 71 | |
| 72 | #endif |
| 73 | |