Emulate POSIX_SIGNALS on MS-Windows.

s/ms-w32.h (POSIX_SIGNALS, struct sigaction, SIG_BLOCK)
 (SIG_SETMASK, SIG_UNBLOCK): Define.
 sysdep.c (sys_signal) [WINDOWSNT]: #ifdef away.
 (wait_for_termination) [WINDOWSNT]: Move MS-Windows specific code
 from non-POSIX_SIGNALS section to POSIX_SIGNALS section.
 w32.c (sigemptyset, sigaddset, sigfillset, sigprocmask): New stubs.

src/ChangeLog

@@ -1,9 +1,20 @@
 2010-05-01  Eli Zaretskii  <eliz@gnu.org>
 
+	Emulate POSIX_SIGNALS on MS-Windows.
+
+	* s/ms-w32.h (POSIX_SIGNALS, struct sigaction, SIG_BLOCK)
+	(SIG_SETMASK, SIG_UNBLOCK): Define.
+
+	* sysdep.c (sys_signal) [WINDOWSNT]: #ifdef away.
+	(wait_for_termination) [WINDOWSNT]: Move MS-Windows specific code
+	from non-POSIX_SIGNALS section to POSIX_SIGNALS section.
+
+	* w32.c (sigemptyset, sigaddset, sigfillset, sigprocmask): New
+	stubs.
+
 	Miscellaneous fixes of bidi display.
 
-	* xdisp.c (find_row_end): New function, refactored from
-	display_line.
+	* xdisp.c (find_row_end): New function, refactored from display_line.
 	(display_line): Use it.
 	(extend_face_to_end_of_line): In almost-filled rows, extend only
 	if the row is R2L and not continued.

src/s/ms-w32.h

@@ -123,6 +123,18 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define IS_DIRECTORY_SEP(_c_) ((_c_) == '/' || (_c_) == '\\')
 #define IS_ANY_SEP(_c_) (IS_DIRECTORY_SEP (_c_) || IS_DEVICE_SEP (_c_))
 
+/* Do we have POSIX signals?  (We don't, but we don't care, either.)  */
+#define POSIX_SIGNALS  1
+#include <sys/types.h>
+struct sigaction {
+  int sa_flags;
+  void (*sa_handler)(int);
+  sigset_t sa_mask;
+};
+#define SIG_BLOCK       1
+#define SIG_SETMASK     2
+#define SIG_UNBLOCK     3
+
 /* The null device on Windows NT. */
 #define NULL_DEVICE     "NUL:"
 

src/sysdep.c

@@ -420,6 +420,10 @@ wait_for_termination (pid)
 	sigpause (SIGEMPTYMASK);
 #else /* not BSD_SYSTEM, and not HPUX version >= 6 */
 #ifdef POSIX_SIGNALS    /* would this work for GNU/Linux as well? */
+#ifdef WINDOWSNT
+      wait (0);
+      break;
+#else /* not WINDOWSNT */
       sigblock (sigmask (SIGCHLD));
       errno = 0;
       if (kill (pid, 0) == -1 && errno == ESRCH)
@@ -429,6 +433,7 @@ wait_for_termination (pid)
 	}
 
       sigsuspend (&empty_mask);
+#endif /* not WINDOWSNT */
 #else /* not POSIX_SIGNALS */
 #ifdef HAVE_SYSV_SIGPAUSE
       sighold (SIGCHLD);
@@ -439,17 +444,12 @@ wait_for_termination (pid)
 	}
       sigpause (SIGCHLD);
 #else /* not HAVE_SYSV_SIGPAUSE */
-#ifdef WINDOWSNT
-      wait (0);
-      break;
-#else /* not WINDOWSNT */
       if (0 > kill (pid, 0))
 	break;
       /* Using sleep instead of pause avoids timing error.
 	 If the inferior dies just before the sleep,
 	 we lose just one second.  */
       sleep (1);
-#endif /* not WINDOWSNT */
 #endif /* not HAVE_SYSV_SIGPAUSE */
 #endif /* not POSIX_SIGNALS */
 #endif /* not BSD_SYSTEM, and not HPUX version >= 6 */
@@ -2105,6 +2105,8 @@ read_input_waiting ()
 
 sigset_t empty_mask, full_mask;
 
+#ifndef WINDOWSNT
+
 signal_handler_t
 sys_signal (int signal_number, signal_handler_t action)
 {
@@ -2133,6 +2135,8 @@ sys_signal (int signal_number, signal_handler_t action)
   return (old_action.sa_handler);
 }
 
+#endif	/* WINDOWSNT */
+
 #ifndef __GNUC__
 /* If we're compiling with GCC, we don't need this function, since it
    can be written as a macro.  */

src/w32.c

@@ -1481,6 +1481,30 @@ sigunblock (int sig)
   return 0;
 }
 
+int
+sigemptyset (sigset_t *set)
+{
+  return 0;
+}
+
+int
+sigaddset (sigset_t *set, int signo)
+{
+  return 0;
+}
+
+int
+sigfillset (sigset_t *set)
+{
+  return 0;
+}
+
+int
+sigprocmask (int how, const sigset_t *set, sigset_t *oset)
+{
+  return 0;
+}
+
 int
 setpgrp (int pid, int gid)
 {