MS-Windows followup for 2012-09-07T01:27:44Z!eggert@cs.ucla.edu, signal-handler cleanup.

 src/w32proc.c (sigaction): New function, emulates Posix 'sigaction'.
 src/w32.c (sigemptyset): Empty the set.
 (sigsetmask, sigmask, sigblock, sigunblock): Remove unused functions.

 nt/inc/ms-w32.h (struct sigaction): Declare sa_handler __cdecl.

Fixes: debbugs:12327

nt/ChangeLog

+2012-09-07  Eli Zaretskii  <eliz@gnu.org>
+
+	* inc/ms-w32.h (struct sigaction): Declare sa_handler __cdecl.
+
 2012-09-05  Juanma Barranquero  <lekktu@gmail.com>
 
 	* config.nt: Sync with autogen/config.in.

nt/inc/ms-w32.h

@@ -127,7 +127,7 @@ typedef int ssize_t;
 
 struct sigaction {
   int sa_flags;
-  void (*sa_handler)(int);
+  void (_CALLBACK_ *sa_handler)(int);
   sigset_t sa_mask;
 };
 #define SIG_BLOCK       1

src/ChangeLog

 2012-09-07  Eli Zaretskii  <eliz@gnu.org>
 
+	* w32proc.c (sigaction): New function, emulates Posix 'sigaction'.
+
+	* w32.c (sigemptyset): Empty the set.
+	(sigsetmask, sigmask, sigblock, sigunblock): Remove unused functions.
+
 	* alloc.c [ENABLE_CHECKING]: Include signal.h, since we need SIGABRT.
 
 2012-09-07  Dmitry Antipov  <dmantipov@yandex.ru>

src/w32.c

@@ -1530,34 +1530,10 @@ is_unc_volume (const char *filename)
 }
 
 /* Routines that are no-ops on NT but are defined to get Emacs to compile.  */
-
-int
-sigsetmask (int signal_mask)
-{
-  return 0;
-}
-
-int
-sigmask (int sig)
-{
-  return 0;
-}
-
-int
-sigblock (int sig)
-{
-  return 0;
-}
-
-int
-sigunblock (int sig)
-{
-  return 0;
-}
-
 int
 sigemptyset (sigset_t *set)
 {
+  *set = 0;
   return 0;
 }
 

src/w32proc.c

@@ -103,6 +103,29 @@ sys_signal (int sig, signal_handler handler)
   return old;
 }
 
+/* Emulate sigaction. */
+int
+sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
+{
+  signal_handler old;
+
+  if (sig != SIGCHLD)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  old = sig_handlers[sig];
+  if (act)
+    sig_handlers[sig] = act->sa_handler;
+  if (oact)
+    {
+      oact->sa_handler = old;
+      oact->sa_flags = 0;
+      oact->sa_mask = empty_mask;
+    }
+  return 0;
+}
+
 /* Defined in <process.h> which conflicts with the local copy */
 #define _P_NOWAIT 1