| /* Convenience declarations when working with <signal.h>. |
| |
| Copyright (C) 2008-2021 Free Software Foundation, Inc. |
| |
| This file is free software: you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as |
| published by the Free Software Foundation; either version 2.1 of the |
| License, or (at your option) any later version. |
| |
| This file 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 Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| #ifndef _GL_SIG_HANDLER_H |
| #define _GL_SIG_HANDLER_H |
| |
| #include <signal.h> |
| |
| #ifndef _GL_INLINE_HEADER_BEGIN |
| #error "Please include config.h first." |
| #endif |
| _GL_INLINE_HEADER_BEGIN |
| #ifndef SIG_HANDLER_INLINE |
| # define SIG_HANDLER_INLINE _GL_INLINE |
| #endif |
| |
| /* Convenience type when working with signal handlers. */ |
| typedef void (*sa_handler_t) (int); |
| |
| /* Return the handler of a signal, as a sa_handler_t value regardless |
| of its true type. The resulting function can be compared to |
| special values like SIG_IGN but it is not portable to call it. */ |
| SIG_HANDLER_INLINE sa_handler_t _GL_ATTRIBUTE_PURE |
| get_handler (struct sigaction const *a) |
| { |
| /* POSIX says that special values like SIG_IGN can only occur when |
| action.sa_flags does not contain SA_SIGINFO. But in Linux 2.4, |
| for example, sa_sigaction and sa_handler are aliases and a signal |
| is ignored if sa_sigaction (after casting) equals SIG_IGN. In |
| this case, this implementation relies on the fact that the two |
| are aliases, and simply returns sa_handler. */ |
| return a->sa_handler; |
| } |
| |
| _GL_INLINE_HEADER_END |
| |
| #endif /* _GL_SIG_HANDLER_H */ |