Remove __need macros from signal.h.

The types affected are __sig_atomic_t, sig_atomic_t, __sigset_t,
sigset_t, sigval_t, sigevent_t, and siginfo_t. __sig_atomic_t is a
scalar, so it's now directly available from bits/types.h.  The others
get bits/types/ headers.

Side effects include: There have been small changes to which
non-signal headers expose which subset of the signal-related types.
A couple of architectures' nested siginfo_t fields had to be renamed
to prevent undesired macro expansion.  Internal code that wants to
manipulate signal masks must now include <sigsetops.h> (which is not
installed) and should be aware that __sigaddset, __sigandset,
__sigdelset, __sigemptyset, and __sigorset no longer return a value
(unlike the public API).  Relatedly, the public signal.h no longer
declares any of those functions.  The obsolete sigmask() macro no
longer has a system-specific definition -- in the cases where it
matters, it didn't work anyway.

New Linux architectures should create bits/siginfo-arch.h and/or
bits/siginfo-consts-arch.h to customize their siginfo_t, rather than
duplicating everything in bits/siginfo.h (which no longer exists).
Add new __SI_* macros if necessary.  Ports to other operating systems
are strongly encouraged to generalize this scheme further.

	* bits/sigevent-consts.h
	* bits/siginfo-consts.h
	* bits/types/__sigset_t.h
	* bits/types/sigevent_t.h
	* bits/types/siginfo_t.h
	* sysdeps/unix/sysv/linux/bits/sigevent-consts.h
	* sysdeps/unix/sysv/linux/bits/siginfo-consts.h
	* sysdeps/unix/sysv/linux/bits/types/__sigset_t.h
	* sysdeps/unix/sysv/linux/bits/types/sigevent_t.h
	* sysdeps/unix/sysv/linux/bits/types/siginfo_t.h:
	New system-dependent bits headers.

	* sysdeps/unix/sysv/linux/bits/siginfo-arch.h
	* sysdeps/unix/sysv/linux/bits/siginfo-consts-arch.h
	* sysdeps/unix/sysv/linux/ia64/bits/siginfo-arch.h
	* sysdeps/unix/sysv/linux/ia64/bits/siginfo-consts-arch.h
	* sysdeps/unix/sysv/linux/mips/bits/siginfo-arch.h
	* sysdeps/unix/sysv/linux/sparc/bits/siginfo-arch.h
	* sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h
	* sysdeps/unix/sysv/linux/tile/bits/siginfo-consts-arch.h
	* sysdeps/unix/sysv/linux/x86/bits/siginfo-arch.h:
	New Linux-only system-dependent bits headers.

	* signal/bits/types/sig_atomic_t.h
	* signal/bits/types/sigset_t.h
	* signal/bits/types/sigval_t.h:
	New non-system-dependent bits headers.

	* sysdeps/generic/sigsetops.h
	* sysdeps/unix/sysv/linux/sigsetops.h:
	New internal headers.

	* include/bits/types/sig_atomic_t.h
	* include/bits/types/sigset_t.h
	* include/bits/types/sigval_t.h:
	New wrappers.

	* signal/sigsetops.h
	* bits/siginfo.h
	* bits/sigset.h
	* sysdeps/unix/sysv/linux/bits/siginfo.h
	* sysdeps/unix/sysv/linux/bits/sigset.h
	* sysdeps/unix/sysv/linux/ia64/bits/siginfo.h
	* sysdeps/unix/sysv/linux/mips/bits/siginfo.h
	* sysdeps/unix/sysv/linux/s390/bits/siginfo.h
	* sysdeps/unix/sysv/linux/sparc/bits/siginfo.h
	* sysdeps/unix/sysv/linux/tile/bits/siginfo.h
	* sysdeps/unix/sysv/linux/x86/bits/siginfo.h:
	Deleted.

	* signal/Makefile, sysdeps/unix/sysv/linux/Makefile:
	Update lists of installed headers.

	* posix/bits/types.h: Define __sig_atomic_t here.
	* signal/signal.h: Use the new bits headers; no need to handle
	__need_sig_atomic_t nor __need_sigset_t.  Don't use __sigmask
	to define sigmask.
	* include/signal.h: No need to handle __need_sig_atomic_t
	nor __need_sigset_t.  Don't define __sigemptyset.

	* io/sys/poll.h, setjmp/setjmp.h
	* sysdeps/arm/sys/ucontext.h, sysdeps/generic/sys/ucontext.h
	* sysdeps/i386/sys/ucontext.h, sysdeps/m68k/sys/ucontext.h
	* sysdeps/mach/hurd/i386/bits/sigcontext.h
	* sysdeps/mips/sys/ucontext.h, sysdeps/powerpc/novmxsetjmp.h
	* sysdeps/pthread/bits/sigthread.h
	* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h
	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h
	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h
	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
	* sysdeps/unix/sysv/linux/s390/sys/ucontext.h
	* sysdeps/unix/sysv/linux/sh/sys/ucontext.h
	* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h
	* sysdeps/unix/sysv/linux/tile/sys/ucontext.h
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h:
	Use bits/types/__sigset_t.h.

	* misc/sys/select.h, posix/spawn.h
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
	* sysdeps/unix/sysv/linux/sys/epoll.h
	* sysdeps/unix/sysv/linux/sys/signalfd.h:
	Use bits/types/sigset_t.h.

	* resolv/netdb.h, rt/mqueue.h: Use bits/types/sigevent_t.h.
	* rt/aio.h: Use bits/types/sigevent_t.h and bits/sigevent-consts.h.
	* socket/sys/socket.h: Don't include bits/sigset.h.

	* login/utmp_file.c, shadow/lckpwdf.c, signal/sigandset.c
	* signal/sigisempty.c, stdlib/abort.c, sysdeps/posix/profil.c
	* sysdeps/posix/sigignore.c, sysdeps/posix/sigintr.c
	* sysdeps/posix/signal.c, sysdeps/posix/sigset.c
	* sysdeps/posix/sprofil.c, sysdeps/posix/sysv_signal.c
	* sysdeps/unix/sysv/linux/nptl-signals.h:
	Include sigsetops.h.

	* signal/sigaddset.c, signal/sigandset.c, signal/sigdelset.c
	* signal/sigorset.c, stdlib/abort.c, sysdeps/posix/sigignore.c
	* sysdeps/posix/signal.c, sysdeps/posix/sigset.c:
	__sigaddset, __sigandset, __sigdelset, __sigemptyset, __sigorset
	now return no value.

	* signal/sigaddset.c, signal/sigdelset.c, signal/sigismem.c
	Include <errno.h>, <signal.h>, and <sigsetops.h> instead of
	"sigsetops.h".

	* signal/sigsetops.c: Explicitly define __sigismember,
	__sigaddset, and __sigdelset as compatibility symbols.

	* signal/Versions: Correct commentary on __sigpause,
	__sigaddset, __sigdelset, __sigismember.

	* inet/rcmd.c: Include sigsetops.h.  Convert old code using
	__sigblock/__sigsetmask to use __sigprocmask and friends.

4 files changed, 26 insertions, 347 deletions

diff --git a/sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h b/sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h
new file mode 100644
index 0000000000..013ad7187d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h
@@ -0,0 +1,11 @@
+/* Architecture-specific adjustments to siginfo_t.  Tile version.  */
+#ifndef _BITS_SIGINFO_ARCH_H
+#define _BITS_SIGINFO_ARCH_H 1
+
+#undef __SI_SIGFAULT_ADDL
+#define __SI_SIGFAULT_ADDL \
+  int _si_trapno;
+
+#define si_trapno	_sifields._sigfault._si_trapno
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/tile/bits/siginfo-consts-arch.h b/sysdeps/unix/sysv/linux/tile/bits/siginfo-consts-arch.h
new file mode 100644
index 0000000000..2e76d2082a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tile/bits/siginfo-consts-arch.h
@@ -0,0 +1,14 @@
+/* Architecture-specific additional siginfo constants.  Tile version.  */
+#ifndef _BITS_SIGINFO_CONSTS_ARCH_H
+#define _BITS_SIGINFO_CONSTS_ARCH_H 1
+
+/* `si_code' values for SIGILL signal.  */
+enum
+{
+  ILL_DBLFLT = ILL_BADSTK + 1,	/* Double fault.  */
+#define ILL_DBLFLT ILL_DBLFLT
+  ILL_HARDWALL			/* User networks hardwall violation.  */
+#define ILL_HARDWALL ILL_HARDWALL
+};
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/tile/bits/siginfo.h b/sysdeps/unix/sysv/linux/tile/bits/siginfo.h
deleted file mode 100644
index 44d66a0597..0000000000
--- a/sysdeps/unix/sysv/linux/tile/bits/siginfo.h
+++ /dev/null
@@ -1,347 +0,0 @@
-/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
-
-   The GNU C Library 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.
-
-   The GNU C Library 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 the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#if !defined _SIGNAL_H && !defined __need_siginfo_t \
-    && !defined __need_sigevent_t
-# error "Never include this file directly.  Use <signal.h> instead"
-#endif
-
-#include <bits/wordsize.h>
-
-#if (!defined __have_sigval_t \
-     && (defined _SIGNAL_H || defined __need_siginfo_t \
-	 || defined __need_sigevent_t))
-# define __have_sigval_t	1
-
-/* Type for data associated with a signal.  */
-typedef union sigval
-  {
-    int sival_int;
-    void *sival_ptr;
-  } sigval_t;
-#endif
-
-#if (!defined __have_siginfo_t \
-     && (defined _SIGNAL_H || defined __need_siginfo_t))
-# define __have_siginfo_t	1
-
-# define __SI_MAX_SIZE     128
-# if __WORDSIZE == 64
-#  define __SI_PAD_SIZE     ((__SI_MAX_SIZE / sizeof (int)) - 4)
-# else
-#  define __SI_PAD_SIZE     ((__SI_MAX_SIZE / sizeof (int)) - 3)
-# endif
-
-typedef struct
-  {
-    int si_signo;		/* Signal number.  */
-    int si_errno;		/* If non-zero, an errno value associated with
-				   this signal, as defined in <errno.h>.  */
-    int si_code;		/* Signal code.  */
-
-    union
-      {
-	int _pad[__SI_PAD_SIZE];
-
-	 /* kill().  */
-	struct
-	  {
-	    __pid_t si_pid;	/* Sending process ID.  */
-	    __uid_t si_uid;	/* Real user ID of sending process.  */
-	  } _kill;
-
-	/* POSIX.1b timers.  */
-	struct
-	  {
-	    int si_tid;		/* Timer ID.  */
-	    int si_overrun;	/* Overrun count.  */
-	    sigval_t si_sigval;	/* Signal value.  */
-	  } _timer;
-
-	/* POSIX.1b signals.  */
-	struct
-	  {
-	    __pid_t si_pid;	/* Sending process ID.  */
-	    __uid_t si_uid;	/* Real user ID of sending process.  */
-	    sigval_t si_sigval;	/* Signal value.  */
-	  } _rt;
-
-	/* SIGCHLD.  */
-	struct
-	  {
-	    __pid_t si_pid;	/* Which child.  */
-	    __uid_t si_uid;	/* Real user ID of sending process.  */
-	    int si_status;	/* Exit value or signal.  */
-	    __clock_t si_utime;
-	    __clock_t si_stime;
-	  } _sigchld;
-
-	/* SIGILL, SIGFPE, SIGSEGV, SIGBUS.  */
-	struct
-	  {
-	    void *si_addr;	/* Faulting insn/memory ref.  */
-	    int si_trapno;	/* TRAP # which caused the signal.  */
-	    short int si_addr_lsb;	/* Valid LSB of the reported address.  */
-	  } _sigfault;
-
-	/* SIGPOLL.  */
-	struct
-	  {
-	    long int si_band;	/* Band event for SIGPOLL.  */
-	    int si_fd;
-	  } _sigpoll;
-
-	/* SIGSYS.  */
-	struct
-	  {
-	    void *_call_addr;	/* Calling user insn.  */
-	    int _syscall;	/* Triggering system call number.  */
-	    unsigned int _arch; /* AUDIT_ARCH_* of syscall.  */
-	  } _sigsys;
-      } _sifields;
-  } siginfo_t;
-
-
-/* X/Open requires some more fields with fixed names.  */
-# define si_pid		_sifields._kill.si_pid
-# define si_uid		_sifields._kill.si_uid
-# define si_timerid	_sifields._timer.si_tid
-# define si_overrun	_sifields._timer.si_overrun
-# define si_status	_sifields._sigchld.si_status
-# define si_utime	_sifields._sigchld.si_utime
-# define si_stime	_sifields._sigchld.si_stime
-# define si_value	_sifields._rt.si_sigval
-# define si_int		_sifields._rt.si_sigval.sival_int
-# define si_ptr		_sifields._rt.si_sigval.sival_ptr
-# define si_addr	_sifields._sigfault.si_addr
-# define si_trapno	_sifields._sigfault.si_trapno
-# define si_addr_lsb	_sifields._sigfault.si_addr_lsb
-# define si_band	_sifields._sigpoll.si_band
-# define si_fd		_sifields._sigpoll.si_fd
-# define si_call_addr 	_sifields._sigsys._call_addr
-# define si_syscall	_sifields._sigsys._syscall
-# define si_arch	_sifields._sigsys._arch
-
-
-/* Values for `si_code'.  Positive values are reserved for kernel-generated
-   signals.  */
-enum
-{
-  SI_ASYNCNL = -60,		/* Sent by asynch name lookup completion.  */
-# define SI_ASYNCNL	SI_ASYNCNL
-  SI_TKILL = -6,		/* Sent by tkill.  */
-# define SI_TKILL	SI_TKILL
-  SI_SIGIO,			/* Sent by queued SIGIO. */
-# define SI_SIGIO	SI_SIGIO
-  SI_ASYNCIO,			/* Sent by AIO completion.  */
-# define SI_ASYNCIO	SI_ASYNCIO
-  SI_MESGQ,			/* Sent by real time mesq state change.  */
-# define SI_MESGQ	SI_MESGQ
-  SI_TIMER,			/* Sent by timer expiration.  */
-# define SI_TIMER	SI_TIMER
-  SI_QUEUE,			/* Sent by sigqueue.  */
-# define SI_QUEUE	SI_QUEUE
-  SI_USER,			/* Sent by kill, sigsend, raise.  */
-# define SI_USER	SI_USER
-  SI_KERNEL = 0x80		/* Send by kernel.  */
-#define SI_KERNEL	SI_KERNEL
-};
-
-
-# if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
-/* `si_code' values for SIGILL signal.  */
-enum
-{
-  ILL_ILLOPC = 1,		/* Illegal opcode.  */
-#  define ILL_ILLOPC	ILL_ILLOPC
-  ILL_ILLOPN,			/* Illegal operand.  */
-#  define ILL_ILLOPN	ILL_ILLOPN
-  ILL_ILLADR,			/* Illegal addressing mode.  */
-#  define ILL_ILLADR	ILL_ILLADR
-  ILL_ILLTRP,			/* Illegal trap. */
-#  define ILL_ILLTRP	ILL_ILLTRP
-  ILL_PRVOPC,			/* Privileged opcode.  */
-#  define ILL_PRVOPC	ILL_PRVOPC
-  ILL_PRVREG,			/* Privileged register.  */
-#  define ILL_PRVREG	ILL_PRVREG
-  ILL_COPROC,			/* Coprocessor error.  */
-#  define ILL_COPROC	ILL_COPROC
-  ILL_BADSTK,			/* Internal stack error.  */
-#  define ILL_BADSTK	ILL_BADSTK
-  ILL_DBLFLT,			/* Double fault.  */
-#  define ILL_DBLFLT	ILL_DBLFLT
-  ILL_HARDWALL			/* User networks hardwall violation.  */
-#  define ILL_HARDWALL	ILL_HARDWALL
-};
-
-/* `si_code' values for SIGFPE signal.  */
-enum
-{
-  FPE_INTDIV = 1,		/* Integer divide by zero.  */
-#  define FPE_INTDIV	FPE_INTDIV
-  FPE_INTOVF,			/* Integer overflow.  */
-#  define FPE_INTOVF	FPE_INTOVF
-  FPE_FLTDIV,			/* Floating point divide by zero.  */
-#  define FPE_FLTDIV	FPE_FLTDIV
-  FPE_FLTOVF,			/* Floating point overflow.  */
-#  define FPE_FLTOVF	FPE_FLTOVF
-  FPE_FLTUND,			/* Floating point underflow.  */
-#  define FPE_FLTUND	FPE_FLTUND
-  FPE_FLTRES,			/* Floating point inexact result.  */
-#  define FPE_FLTRES	FPE_FLTRES
-  FPE_FLTINV,			/* Floating point invalid operation.  */
-#  define FPE_FLTINV	FPE_FLTINV
-  FPE_FLTSUB			/* Subscript out of range.  */
-#  define FPE_FLTSUB	FPE_FLTSUB
-};
-
-/* `si_code' values for SIGSEGV signal.  */
-enum
-{
-  SEGV_MAPERR = 1,		/* Address not mapped to object.  */
-#  define SEGV_MAPERR	SEGV_MAPERR
-  SEGV_ACCERR			/* Invalid permissions for mapped object.  */
-#  define SEGV_ACCERR	SEGV_ACCERR
-};
-
-/* `si_code' values for SIGBUS signal.  */
-enum
-{
-  BUS_ADRALN = 1,		/* Invalid address alignment.  */
-#  define BUS_ADRALN	BUS_ADRALN
-  BUS_ADRERR,			/* Non-existant physical address.  */
-#  define BUS_ADRERR	BUS_ADRERR
-  BUS_OBJERR,			/* Object specific hardware error.  */
-#  define BUS_OBJERR	BUS_OBJERR
-  BUS_MCEERR_AR,		/* Hardware memory error: action required.  */
-#  define BUS_MCEERR_AR	BUS_MCEERR_AR
-  BUS_MCEERR_AO			/* Hardware memory error: action optional.  */
-#  define BUS_MCEERR_AO	BUS_MCEERR_AO
-};
-# endif
-
-# ifdef __USE_XOPEN_EXTENDED
-/* `si_code' values for SIGTRAP signal.  */
-enum
-{
-  TRAP_BRKPT = 1,		/* Process breakpoint.  */
-#  define TRAP_BRKPT	TRAP_BRKPT
-  TRAP_TRACE			/* Process trace trap.  */
-#  define TRAP_TRACE	TRAP_TRACE
-};
-# endif
-
-# if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
-/* `si_code' values for SIGCHLD signal.  */
-enum
-{
-  CLD_EXITED = 1,		/* Child has exited.  */
-#  define CLD_EXITED	CLD_EXITED
-  CLD_KILLED,			/* Child was killed.  */
-#  define CLD_KILLED	CLD_KILLED
-  CLD_DUMPED,			/* Child terminated abnormally.  */
-#  define CLD_DUMPED	CLD_DUMPED
-  CLD_TRAPPED,			/* Traced child has trapped.  */
-#  define CLD_TRAPPED	CLD_TRAPPED
-  CLD_STOPPED,			/* Child has stopped.  */
-#  define CLD_STOPPED	CLD_STOPPED
-  CLD_CONTINUED			/* Stopped child has continued.  */
-#  define CLD_CONTINUED	CLD_CONTINUED
-};
-
-/* `si_code' values for SIGPOLL signal.  */
-enum
-{
-  POLL_IN = 1,			/* Data input available.  */
-#  define POLL_IN	POLL_IN
-  POLL_OUT,			/* Output buffers available.  */
-#  define POLL_OUT	POLL_OUT
-  POLL_MSG,			/* Input message available.   */
-#  define POLL_MSG	POLL_MSG
-  POLL_ERR,			/* I/O error.  */
-#  define POLL_ERR	POLL_ERR
-  POLL_PRI,			/* High priority input available.  */
-#  define POLL_PRI	POLL_PRI
-  POLL_HUP			/* Device disconnected.  */
-#  define POLL_HUP	POLL_HUP
-};
-# endif
-
-# undef __need_siginfo_t
-#endif	/* !have siginfo_t && (have _SIGNAL_H || need siginfo_t).  */
-
-
-#if (defined _SIGNAL_H || defined __need_sigevent_t) \
-    && !defined __have_sigevent_t
-# define __have_sigevent_t	1
-
-/* Structure to transport application-defined values with signals.  */
-# define __SIGEV_MAX_SIZE	64
-# if __WORDSIZE == 64
-#  define __SIGEV_PAD_SIZE	((__SIGEV_MAX_SIZE / sizeof (int)) - 4)
-# else
-#  define __SIGEV_PAD_SIZE	((__SIGEV_MAX_SIZE / sizeof (int)) - 3)
-# endif
-
-/* Forward declaration.  */
-# ifndef __have_pthread_attr_t
-typedef union pthread_attr_t pthread_attr_t;
-#  define __have_pthread_attr_t	1
-# endif
-
-typedef struct sigevent
-  {
-    sigval_t sigev_value;
-    int sigev_signo;
-    int sigev_notify;
-
-    union
-      {
-	int _pad[__SIGEV_PAD_SIZE];
-
-	/* When SIGEV_SIGNAL and SIGEV_THREAD_ID set, LWP ID of the
-	   thread to receive the signal.  */
-	__pid_t _tid;
-
-	struct
-	  {
-	    void (*_function) (sigval_t);	/* Function to start.  */
-	    pthread_attr_t *_attribute;		/* Thread attributes.  */
-	  } _sigev_thread;
-      } _sigev_un;
-  } sigevent_t;
-
-/* POSIX names to access some of the members.  */
-# define sigev_notify_function   _sigev_un._sigev_thread._function
-# define sigev_notify_attributes _sigev_un._sigev_thread._attribute
-
-/* `sigev_notify' values.  */
-enum
-{
-  SIGEV_SIGNAL = 0,		/* Notify via signal.  */
-# define SIGEV_SIGNAL	SIGEV_SIGNAL
-  SIGEV_NONE,			/* Other notification: meaningless.  */
-# define SIGEV_NONE	SIGEV_NONE
-  SIGEV_THREAD,			/* Deliver via thread creation.  */
-# define SIGEV_THREAD	SIGEV_THREAD
-
-  SIGEV_THREAD_ID = 4		/* Send signal to specific thread.  */
-#define SIGEV_THREAD_ID	SIGEV_THREAD_ID
-};
-
-#endif	/* have _SIGNAL_H.  */
diff --git a/sysdeps/unix/sysv/linux/tile/sys/ucontext.h b/sysdeps/unix/sysv/linux/tile/sys/ucontext.h
index 8fc2f13834..4a40e5710f 100644
--- a/sysdeps/unix/sysv/linux/tile/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/tile/sys/ucontext.h
@@ -24,6 +24,7 @@
 
 /* We need the signal context definitions even if they are not exposed
    by <signal.h>.  */
+#include <bits/types/__sigset_t.h>
 #include <bits/sigcontext.h>
 #include <bits/sigstack.h>
 #include <bits/types/struct_sigstack.h>