Split up bits/sigstack.h.

bits/sigstack.h contains four things: the legacy struct sigstack type,
the preferred stack_t type, the SS_* enum values and macros for signal
stack sizes.

These vary in different ways between glibc configurations; in
particular, the stack sizes vary much more than any of the other
pieces.  Furthermore, these pieces have different standard namespace
rules for when they should be visible (not currently visible in
conform/ results both because the relevant tests are XFAILed for
sys/ucontext.h namespace issues, and because some of the expectations
are incorrect in the same way as the headers, e.g. neither
expectations nor headers reflect that current POSIX no longer has
either the sigstack function or the sigstack structure).

To reduce duplication of identical definitions, and facilitate
namespace fixes without requiring the same feature test macro
conditions to be repeated in many versions of the same header, this
patch splits bits/sigstack.h up into four headers.  It keeps the stack
size macros, while new bits/types/struct_sigstack.h,
bits/types/stack_t.h and bits/ss_flags.h are added for the other
pieces.  bits/types/struct_sigstack.h is the same everywhere,
bits/types/stack_t.h has three variants different in the order of the
structure elements (generic = MIPS Linux, and other Linux), and
bits/ss_flags.h has generic and Linux variants.

This patch includes the new headers everywhere that included
<bits/sigstack.h>, so should cause no difference to what any public
header defines.  Subsequent namespace fixes would then remove or
condition some of those includes.

There should be no conflicts with Zack's changes to signal.h types,
beyond the trivial conflict of both making additions to
signal/Makefile's headers list; the two patches affect disjoint sets
of types and other definitions.

Tested for x86_64 and x86, and with build-many-glibcs.py.

	* bits/ss_flags.h: New file.
	* bits/types/stack_t.h: Likewise.
	* include/bits/types/struct_sigstack.h: Likewise.
	* signal/bits/types/struct_sigstack.h: Likewise.
	* sysdeps/unix/sysv/linux/bits/ss_flags.h: Likewise.
	* sysdeps/unix/sysv/linux/bits/types/stack_t.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/types/stack_t.h: Likewise.
	* signal/Makefile (headers): Add bits/types/struct_sigstack.h,
	bits/types/stack_t.h and bits/ss_flags.h.
	* signal/signal.h [__USE_XOPEN_EXTENDED || __USE_XOPEN2K8]:
	Include <bits/types/struct_sigstack.h>, <bits/types/stack_t.h> and
	<bits/ss_flags.h>.
	* bits/sigstack.h (struct sigstack): Remove.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/unix/sysv/linux/aarch64/bits/sigstack.h
	(struct sigstack): Likewise.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/sigstack.h (struct sigstack):
	Likewise.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/unix/sysv/linux/bits/sigstack.h (struct sigstack):
	Likewise.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/sigstack.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/bits/sigstack.h (struct sigstack):
	Likewise.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h
	(struct sigstack): Likewise.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/sigstack.h (struct sigstack):
	Likewise.
	(stack_t): Likewise.
	(SS_ONSTACK): Likewise.
	(SS_DISABLE): Likewise.
	* sysdeps/arm/sys/ucontext.h: Include
	<bits/types/struct_sigstack.h>, <bits/types/stack_t.h> and
	<bits/ss_flags.h>.
	* sysdeps/generic/sys/ucontext.h: Likewise.
	* sysdeps/i386/sys/ucontext.h: Likewise.
	* sysdeps/m68k/sys/ucontext.h: Likewise.
	* sysdeps/mips/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/alpha/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/arm/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/bits/sigcontext.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/sh/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/tile/sys/ucontext.h: Likewise.
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h: Likewise.

3 files changed, 68 insertions, 27 deletions

diff --git a/bits/sigstack.h b/bits/sigstack.h
index 42143e363a..3127c325e5 100644
--- a/bits/sigstack.h
+++ b/bits/sigstack.h
@@ -23,33 +23,6 @@
 # error "Never include this file directly.  Use <signal.h> instead"
 #endif
 
-
-/* Structure describing a signal stack (obsolete).  */
-struct sigstack
-  {
-    __ptr_t ss_sp;		/* Signal stack pointer.  */
-    int ss_onstack;		/* Nonzero if executing on this stack.  */
-  };
-
-
-/* Alternate, preferred interface.  */
-typedef struct sigaltstack
-  {
-    __ptr_t ss_sp;
-    size_t ss_size;
-    int ss_flags;
-  } stack_t;
-
-
-/* Possible values for `ss_flags.'.  */
-enum
-{
-  SS_ONSTACK = 0x0001,
-#define SS_ONSTACK	SS_ONSTACK
-  SS_DISABLE = 0x0004
-#define SS_DISABLE	SS_DISABLE
-};
-
 /* Minumum stack size for a signal handler.  */
 #define MINSIGSTKSZ	8192
 
diff --git a/bits/ss_flags.h b/bits/ss_flags.h
new file mode 100644
index 0000000000..fa3836c122
--- /dev/null
+++ b/bits/ss_flags.h
@@ -0,0 +1,35 @@
+/* ss_flags values for stack_t.
+   Copyright (C) 1998-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#ifndef _BITS_SS_FLAGS_H
+#define _BITS_SS_FLAGS_H 1
+
+#if !defined _SIGNAL_H && !defined _SYS_UCONTEXT_H
+# error "Never include this file directly.  Use <signal.h> instead"
+#endif
+
+/* Possible values for `ss_flags.'.  */
+enum
+{
+  SS_ONSTACK = 0x0001,
+#define SS_ONSTACK	SS_ONSTACK
+  SS_DISABLE = 0x0004
+#define SS_DISABLE	SS_DISABLE
+};
+
+#endif /* bits/ss_flags.h */
diff --git a/bits/types/stack_t.h b/bits/types/stack_t.h
new file mode 100644
index 0000000000..3cf0a4019a
--- /dev/null
+++ b/bits/types/stack_t.h
@@ -0,0 +1,33 @@
+/* Define stack_t.
+   Copyright (C) 1998-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#ifndef __stack_t_defined
+#define __stack_t_defined 1
+
+#define __need_size_t
+#include <stddef.h>
+
+/* Structure describing a signal stack.  */
+typedef struct sigaltstack
+  {
+    void *ss_sp;
+    size_t ss_size;
+    int ss_flags;
+  } stack_t;
+
+#endif