Factor out shared definitions from bits/signum.h.

Many of the things defined by bits/signum.h are invariant across all
supported operating systems.  This patch factors out all of them to a
new header bits/signum-generic.h, which each bits/signum.h will include
and then override whichever things need adjustment.  Normally that will
mean, at most, adding or changing a few signal numbers.

A user-visible side effect is that the obsolete signal constant SIGUNUSED
(which is an alias for SIGSYS on all platforms that define it) is no
longer exposed by any version of bits/signum.h.

A side effect only relevant to glibc hackers is that _NSIG is now defined
in terms of __SIGRTMAX, instead of the other way around.  This is because
__SIGRTMAX varies from platform to platform, but _NSIG==__SIGRTMAX+1 is
true universally.  If your platform doesn't support realtime signals,
leave __SIGRTMAX equal to __SIGRTMIN.

I also added a Linux-specific test to make sure that our signal constants
match the ones in <asm/signal.h>, since we can't use that header (it's
not even vaguely namespace-clean).

	* bits/signum-generic.h: Renamed from bits/signum.h.
	Add proper multiple include guard and misuse check.
	Define __SIGRTMIN = __SIGRTMAX = 32, and define _NSIG = __SIGRTMAX+1.
	Move definition of SIGIO to "archaic names for compatibility" section.
	* bits/signum.h: New file which just includes bits/signum-generic.h.
	* sysdeps/unix/bsd/bits/signum.h
	* sysdeps/unix/sysv/linux/bits/signum.h
	* sysdeps/unix/sysv/linux/alpha/bits/signum.h
	* sysdeps/unix/sysv/linux/hppa/bits/signum.h
	* sysdeps/unix/sysv/linux/mips/bits/signum.h
	* sysdeps/unix/sysv/linux/sparc/bits/signum.h
	Just include <bits/signum-generic.h> and then add or adjust
	signal constants.  Do not define SIGUNUSED, SIGRTMIN, or SIGRTMAX.

	* signal/Makefile: Install bits/signum-generic.h.
	* signal/signal.h: Define SIGRTMIN and SIGRTMAX here.

	* sysdeps/generic/siglist.h: SIGSYS and SIGWINCH are
	universal.  Prefer SIGPOLL to SIGIO. Simplify #ifdeffage.

	* sysdeps/unix/sysv/linux/tst-signal-numbers.sh: New test.
	* sysdeps/unix/sysv/linux/Makefile: Run it.

1 files changed, 14 insertions, 55 deletions

diff --git a/sysdeps/unix/sysv/linux/alpha/bits/signum.h b/sysdeps/unix/sysv/linux/alpha/bits/signum.h
index e5cc5218e3..8227be91b5 100644
--- a/sysdeps/unix/sysv/linux/alpha/bits/signum.h
+++ b/sysdeps/unix/sysv/linux/alpha/bits/signum.h
@@ -16,66 +16,25 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-#ifdef	_SIGNAL_H
+#ifndef _BITS_SIGNUM_H
+#define _BITS_SIGNUM_H 1
 
-/* Fake signal functions.  */
-#define SIG_ERR ((__sighandler_t) -1) /* Error return.  */
-#define SIG_DFL ((__sighandler_t) 0) /* Default action.  */
-#define SIG_IGN ((__sighandler_t) 1) /* Ignore signal.  */
-
-#ifdef __USE_XOPEN
-# define SIG_HOLD	((__sighandler_t) 2)	/* Add signal to hold mask.  */
+#ifndef _SIGNAL_H
+#error "Never include <bits/signum.h> directly; use <signal.h> instead."
 #endif
 
-/*
- * Linux/AXP has different signal numbers that Linux/i386: I'm trying
- * to make it OSF/1 binary compatible, at least for normal binaries.
- */
-#define SIGHUP		 1
-#define SIGINT		 2
-#define SIGQUIT		 3
-#define SIGILL		 4
-#define SIGTRAP		 5
-#define SIGABRT		 6
-#define SIGEMT		 7
-#define SIGFPE		 8
-#define SIGKILL		 9
-#define SIGBUS		10
-#define SIGSEGV		11
-#define SIGSYS		12
-#define SIGPIPE		13
-#define SIGALRM		14
-#define SIGTERM		15
-#define SIGURG		16
-#define SIGSTOP		17
-#define SIGTSTP		18
-#define SIGCONT		19
-#define SIGCHLD		20
-#define SIGCLD          SIGCHLD
-#define SIGTTIN		21
-#define SIGTTOU		22
-#define SIGIO		23
-#define SIGXCPU		24
-#define SIGXFSZ		25
-#define SIGVTALRM	26
-#define SIGPROF		27
-#define SIGWINCH	28
-#define SIGINFO		29
-#define SIGUSR1		30
-#define SIGUSR2		31
-
-#define SIGPOLL	SIGIO
-#define SIGPWR	SIGINFO
-#define SIGIOT	SIGABRT
+#include <bits/signum-generic.h>
 
-#define	_NSIG		65	/* Biggest signal number + 1.  */
+/* Adjustments and additions to the signal number constants for
+   Linux/Alpha.  Signal values on this platform were chosen for OSF/1
+   binary compatibility, and are therefore almost identical to the
+   BSD-derived defaults.  */
 
-#define SIGRTMIN	(__libc_current_sigrtmin ())
-#define SIGRTMAX	(__libc_current_sigrtmax ())
+#define SIGEMT		 7	/* Emulator trap (4.2 BSD).  */
+#define SIGINFO		29	/* Information request (BSD).  */
+#define SIGPWR		SIGINFO	/* Power failure imminent (System V).  */
 
-/* These are the hard limits of the kernel.  These values should not be
-   used directly at user level.  */
-#define __SIGRTMIN	32
-#define __SIGRTMAX	(_NSIG - 1)
+#undef	__SIGRTMAX
+#define __SIGRTMAX	64
 
 #endif	/* <signal.h> included.  */