3 files changed, 20 insertions, 9 deletions

diff --git a/src/emacs.c b/src/emacs.c
index 68d0ce31696..dac22ca1c23 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -407,9 +407,13 @@ main (argc, argv, envp)
       signal (SIGEMT, fatal_error_signal);
 #endif
       signal (SIGFPE, fatal_error_signal);
+#ifdef SIGBUS
       signal (SIGBUS, fatal_error_signal);
+#endif
       signal (SIGSEGV, fatal_error_signal);
+#ifdef SIGSYS
       signal (SIGSYS, fatal_error_signal);
+#endif
       signal (SIGTERM, fatal_error_signal);
 #ifdef SIGXCPU
       signal (SIGXCPU, fatal_error_signal);
diff --git a/src/sysdep.c b/src/sysdep.c
index a6c1bdfbb34..99df6865338 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -2040,14 +2040,10 @@ static struct sigaction new_action, old_action;
 
 init_signals ()
 {
-#ifdef POSIX_SIGNALS
-  sigemptyset (&signal_empty_mask);
-  sigfillset (&signal_full_mask);
-#endif
+  sigemptyset (&empty_mask);
+  sigfillset (&full_mask);
 }
 
-int (*signal_handler_t) ();
-
 signal_handler_t
 sys_signal (int signal_number, signal_handler_t action)
 {
@@ -2417,6 +2413,7 @@ sys_write (fildes, buf, nbyte)
  *      always negligible.   Fred Fish, Unisoft Systems Inc.
  */
 
+#ifndef HAVE_SYS_SIGLIST
 char *sys_siglist[NSIG + 1] =
 {
 #ifdef AIX
@@ -2477,6 +2474,7 @@ char *sys_siglist[NSIG + 1] =
 #endif /* not AIX */
   0
   };
+#endif HAVE_SYS_SIGLIST
 
 /*
  *      Warning, this function may not duplicate 4.2 action properly
diff --git a/src/syssignal.h b/src/syssignal.h
index dddaee80924..ad3958647f2 100644
--- a/src/syssignal.h
+++ b/src/syssignal.h
@@ -18,6 +18,9 @@ along with GNU Emacs; see the file COPYING.  If not, write to
 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #ifdef POSIX_SIGNALS
+
+#include <signal.h>
+
 #define SIGMASKTYPE sigset_t
 
 #define SIGEMPTYMASK (empty_mask)
@@ -26,6 +29,7 @@ extern sigset_t empty_mask, full_mask, temp_mask;
 
 /* POSIX pretty much destroys any possibility of writing sigmask as a
    macro in standard C.  */
+#ifndef sigmask
 #ifdef __GNUC__
 #define sigmask(SIG)                            \
   ({                                            \
@@ -37,6 +41,7 @@ extern sigset_t empty_mask, full_mask, temp_mask;
 #else /* ! defined (__GNUC__) */
 #define sigmask(SIG) (sys_sigmask (SIG))
 #endif /* ! defined (__GNUC__) */
+#endif
 
 #define sigpause(SIG)    sys_sigpause(SIG)
 #define sigblock(SIG)    sys_sigblock(SIG)
@@ -45,9 +50,13 @@ extern sigset_t empty_mask, full_mask, temp_mask;
 #define sighold(SIG)     ONLY_USED_IN_BSD_4_1
 #define sigrelse(SIG)    ONLY_USED_IN_BSD_4_1
 
-int (*sys_signal (int signal_number, int (*action)())) ();
-int sys_sigpause (int signal_number);
-sigset_t sys_sigblock (sigset_t new_mask);
+/* Whether this is what all systems want or not, this is what
+   appears to be assumed in the source, for example data.c:arith_error() */
+typedef RETSIGTYPE (*signal_handler_t) (int);
+
+signal_handler_t sys_signal (int signal_number, int (*action)());
+int      sys_sigpause   (sigset_t new_mask);
+sigset_t sys_sigblock   (sigset_t new_mask);
 sigset_t sys_sigunblock (sigset_t new_mask);
 sigset_t sys_sigsetmask (sigset_t new_mask);