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diff --git a/lib/fatal-signal.h b/lib/fatal-signal.h
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+++ b/lib/fatal-signal.h
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+/* Emergency actions in case of a fatal signal.
+   Copyright (C) 2003-2004, 2009-2022 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   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 _FATAL_SIGNAL_H
+#define _FATAL_SIGNAL_H
+
+#include <signal.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* It is often useful to do some cleanup action when a usually fatal signal
+   terminates the process, like removing a temporary file or killing a
+   subprocess that may be stuck waiting for a device, pipe or network input.
+   Such signals are SIGHUP, SIGINT, SIGPIPE, SIGTERM, and possibly others.
+   The limitation of this facility is that it cannot work for SIGKILL.
+
+   Signals with a SIG_IGN handler are considered to be non-fatal.  The
+   functions in this file assume that when a SIG_IGN handler is installed
+   for a signal, it was installed before any functions in this file were
+   called and it stays so for the whole lifetime of the process.  */
+
+/* Register a cleanup function to be executed when a catchable fatal signal
+   occurs.
+
+   Restrictions for the cleanup function:
+     - The cleanup function can do all kinds of system calls.  It may also
+       modify (clobber) errno.
+     - It can also access application dependent memory locations and data
+       structures provided they are in a consistent state. One way to ensure
+       this is through block_fatal_signals()/unblock_fatal_signals(), see
+       below.  Another - more tricky - way to ensure this is the careful use
+       of 'volatile'.
+   However,
+     - malloc() and similarly complex facilities are not safe to be called
+       because they are not guaranteed to be in a consistent state.
+     - Also, the cleanup function must not block the catchable fatal signals
+       and leave them blocked upon return.
+
+   The cleanup function is executed asynchronously.  It is unspecified
+   whether during its execution the catchable fatal signals are blocked
+   or not.
+
+   Return 0 upon success, or -1 if there was a memory allocation problem.  */
+extern int at_fatal_signal (_GL_ASYNC_SAFE void (*function) (int sig));
+
+
+/* Sometimes it is necessary to block the usually fatal signals while the
+   data structures being accessed by the cleanup action are being built or
+   reorganized.  This is the case, for example, when a temporary file or
+   directory is created through mkstemp() or mkdtemp(), because these
+   functions create the temporary file or directory _before_ returning its
+   name to the application.  */
+
+/* Temporarily delay the catchable fatal signals.
+   The signals will be blocked (= delayed) until the next call to
+   unblock_fatal_signals().  If the signals are already blocked, a further
+   call to block_fatal_signals() has no effect.  */
+extern void block_fatal_signals (void);
+
+/* Stop delaying the catchable fatal signals.  */
+extern void unblock_fatal_signals (void);
+
+
+/* Return the list of signals that block_fatal_signals/unblock_fatal_signals
+   would block or unblock.
+   Fills signals[0..count-1] and returns count.  */
+extern unsigned int get_fatal_signals (int signals[64]);
+
+/* Return the list of signals that block_fatal_signals/unblock_fatal_signals
+   would block or unblock.  */
+extern const sigset_t * get_fatal_signal_set (void);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _FATAL_SIGNAL_H */