signal: Add signum-{generic,arch}.h

It refactor how signals are defined by each architecture.  Instead of
include a generic header (bits/signum-generic.h) and undef non-default
values in an arch specific header (bits/signum.h) the new scheme uses a
common definition (bits/signum-generic.h) and each architectures add
its specific definitions on a new header (bits/signum-arch.h).

For Linux it requires copy some system default definitions to alpha,
hppa, and sparc.  They are historical values and newer ports uses
the generic Linux signum-arch.h.

For Hurd the BSD signum is removed and moved to a new header (it is
used currently only on Hurd).

Checked on a build against all affected ABIs.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

3 files changed, 62 insertions, 56 deletions

diff --git a/bits/signum-arch.h b/bits/signum-arch.h
new file mode 100644
index 0000000000..abecff2345
--- /dev/null
+++ b/bits/signum-arch.h
@@ -0,0 +1,59 @@
+/* Signal number constants.  Specific architecture definitions.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef	_BITS_SIGNUM_ARCH_H
+#define _BITS_SIGNUM_ARCH_H 1
+
+#ifndef _SIGNAL_H
+#error "Never include <bits/signum-generic.h> directly; use <signal.h> instead."
+#endif
+
+/* Historical signals specified by POSIX. */
+#define SIGBUS		10	/* Bus error.  */
+#define SIGSYS		12	/* Bad system call.  */
+
+/* New(er) POSIX signals (1003.1-2008, 1003.1-2013).  */
+#define SIGURG		16	/* Urgent data is available at a socket.  */
+#define SIGSTOP		17	/* Stop, unblockable.  */
+#define SIGTSTP		18	/* Keyboard stop.  */
+#define SIGCONT		19	/* Continue.  */
+#define SIGCHLD		20	/* Child terminated or stopped.  */
+#define SIGTTIN		21	/* Background read from control terminal.  */
+#define SIGTTOU		22	/* Background write to control terminal.  */
+#define SIGPOLL		23	/* Pollable event occurred (System V).  */
+#define SIGXCPU		24	/* CPU time limit exceeded.  */
+#define SIGVTALRM	26	/* Virtual timer expired.  */
+#define SIGPROF		27	/* Profiling timer expired.  */
+#define SIGXFSZ		25	/* File size limit exceeded.  */
+#define SIGUSR1		30	/* User-defined signal 1.  */
+#define SIGUSR2		31	/* User-defined signal 2.  */
+
+/* Nonstandard signals found in all modern POSIX systems
+   (including both BSD and Linux).  */
+#define SIGWINCH	28	/* Window size change (4.3 BSD, Sun).  */
+
+/* Archaic names for compatibility.  */
+#define SIGIO		SIGPOLL	/* I/O now possible (4.2 BSD).  */
+#define SIGIOT		SIGABRT	/* IOT instruction, abort() on a PDP-11.  */
+#define SIGCLD		SIGCHLD	/* Old System V name */
+
+/* By default no real-time signals are supported.  */
+#define __SIGRTMIN	32
+#define __SIGRTMAX	__SIGRTMIN
+
+#endif
diff --git a/bits/signum-generic.h b/bits/signum-generic.h
index 504e5fb8c8..67131853c2 100644
--- a/bits/signum-generic.h
+++ b/bits/signum-generic.h
@@ -57,31 +57,9 @@
 #define	SIGQUIT		3	/* Quit.  */
 #define	SIGTRAP		5	/* Trace/breakpoint trap.  */
 #define	SIGKILL		9	/* Killed.  */
-#define SIGBUS		10	/* Bus error.  */
-#define	SIGSYS		12	/* Bad system call.  */
 #define	SIGPIPE		13	/* Broken pipe.  */
 #define	SIGALRM		14	/* Alarm clock.  */
 
-/* New(er) POSIX signals (1003.1-2008, 1003.1-2013).  */
-#define	SIGURG		16	/* Urgent data is available at a socket.  */
-#define	SIGSTOP		17	/* Stop, unblockable.  */
-#define	SIGTSTP		18	/* Keyboard stop.  */
-#define	SIGCONT		19	/* Continue.  */
-#define	SIGCHLD		20	/* Child terminated or stopped.  */
-#define	SIGTTIN		21	/* Background read from control terminal.  */
-#define	SIGTTOU		22	/* Background write to control terminal.  */
-#define	SIGPOLL		23	/* Pollable event occurred (System V).  */
-#define	SIGXCPU		24	/* CPU time limit exceeded.  */
-#define	SIGXFSZ		25	/* File size limit exceeded.  */
-#define	SIGVTALRM	26	/* Virtual timer expired.  */
-#define	SIGPROF		27	/* Profiling timer expired.  */
-#define	SIGUSR1		30	/* User-defined signal 1.  */
-#define	SIGUSR2		31	/* User-defined signal 2.  */
-
-/* Nonstandard signals found in all modern POSIX systems
-   (including both BSD and Linux).  */
-#define	SIGWINCH	28	/* Window size change (4.3 BSD, Sun).  */
-
 /* Archaic names for compatibility.  */
 #define	SIGIO		SIGPOLL	/* I/O now possible (4.2 BSD).  */
 #define	SIGIOT		SIGABRT	/* IOT instruction, abort() on a PDP-11.  */
@@ -93,8 +71,9 @@
    but some real-time signals may be used internally by glibc.  Do not
    use these constants in application code; use SIGRTMIN and SIGRTMAX
    (defined in signal.h) instead.  */
-#define __SIGRTMIN	32
-#define __SIGRTMAX	__SIGRTMIN
+
+/* Include system specific bits.  */
+#include <bits/signum-arch.h>
 
 /* Biggest signal number + 1 (including real-time signals).  */
 #define _NSIG		(__SIGRTMAX + 1)
diff --git a/bits/signum.h b/bits/signum.h
deleted file mode 100644
index 183e3c0545..0000000000
--- a/bits/signum.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Signal number constants.  Generic version.
-   Copyright (C) 2017-2020 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
-   <https://www.gnu.org/licenses/>.  */
-
-#ifndef _BITS_SIGNUM_H
-#define _BITS_SIGNUM_H 1
-
-#ifndef _SIGNAL_H
-#error "Never include <bits/signum.h> directly; use <signal.h> instead."
-#endif
-
-#include <bits/signum-generic.h>
-
-/* This operating system does not need to override any of the generic
-   signal number assignments in bits/signum-generic.h, nor to add any
-   additional signal constants.  */
-
-#endif /* bits/signum.h.  */