Remove dead code dealing with POSIX_SIGNALS.

* atimer.c (set_alarm): Remove dead code, all USG systems define
POSIX_SIGNALS.
* data.c (arith_error): Likewise.
* keyboard.c (input_available_signal, handle_user_signal)
(interrupt_signal): Likewise.
* process.c (sigchld_handler): Likewise.
(create_process): Remove if 0 code.  Remove HPUX conditional when
!defined (POSIX_SIGNALS), it cannot be true.
* syssignal.h: Remove USG5_4 and USG conditionals when
!POSIX_SIGNALS, they cannot be true.

6 files changed, 19 insertions, 94 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index ab47c2cab02..7242bd4c371 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,17 @@
 2010-03-22  Dan Nicolaescu  <dann@ics.uci.edu>
 
+        Remove dead code dealing with POSIX_SIGNALS.
+        * atimer.c (set_alarm): Remove dead code, all USG systems define
+        POSIX_SIGNALS.
+        * data.c (arith_error): Likewise.
+        * keyboard.c (input_available_signal, handle_user_signal)
+        (interrupt_signal): Likewise.
+        * process.c (sigchld_handler): Likewise.
+        (create_process): Remove if 0 code.  Remove HPUX conditional when
+        !defined (POSIX_SIGNALS), it cannot be true.
+        * syssignal.h: Remove USG5_4 and USG conditionals when
+        !POSIX_SIGNALS, they cannot be true.
+
         * keyboard.c (Fset_input_interrupt_mode): Remove code depending on
         NO_SOCK_SIGIO, not used anymore.
 
diff --git a/src/atimer.c b/src/atimer.c
index 432e2590dad..556272d7918 100644
--- a/src/atimer.c
+++ b/src/atimer.c
@@ -296,12 +296,6 @@ unwind_stop_other_atimers (dummy)
 static void
 set_alarm ()
 {
-#if defined (USG) && !defined (POSIX_SIGNALS)
-  /* USG systems forget handlers when they are used;
-     must reestablish each time.  */
-  signal (SIGALRM, alarm_signal_handler);
-#endif /* USG */
-
   if (atimers)
     {
       EMACS_TIME now, time;
diff --git a/src/data.c b/src/data.c
index e405ca6af9e..bdba3a9bb36 100644
--- a/src/data.c
+++ b/src/data.c
@@ -3291,11 +3291,6 @@ SIGTYPE
 arith_error (signo)
      int signo;
 {
-#if defined(USG) && !defined(POSIX_SIGNALS)
-  /* USG systems forget handlers when they are used;
-     must reestablish each time */
-  signal (signo, arith_error);
-#endif /* USG */
   sigsetmask (SIGEMPTYMASK);
 
   SIGNAL_THREAD_CHECK (signo);
diff --git a/src/keyboard.c b/src/keyboard.c
index 6582af7f805..f6d6704b373 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -7507,12 +7507,6 @@ input_available_signal (signo)
 {
   /* Must preserve main program's value of errno.  */
   int old_errno = errno;
-#if defined (USG) && !defined (POSIX_SIGNALS)
-  /* USG systems forget handlers when they are used;
-     must reestablish each time */
-  signal (signo, input_available_signal);
-#endif /* USG */
-
   SIGNAL_THREAD_CHECK (signo);
 
 #ifdef SYNC_INPUT
@@ -7595,12 +7589,6 @@ handle_user_signal (sig)
   int old_errno = errno;
   struct user_signal_info *p;
 
-#if defined (USG) && !defined (POSIX_SIGNALS)
-  /* USG systems forget handlers when they are used;
-     must reestablish each time */
-  signal (sig, handle_user_signal);
-#endif
-
   SIGNAL_THREAD_CHECK (sig);
 
   for (p = user_signals; p; p = p->next)
@@ -11089,13 +11077,6 @@ interrupt_signal (signalnum)	/* If we don't have an argument, */
   int old_errno = errno;
   struct terminal *terminal;
 
-#if defined (USG) && !defined (POSIX_SIGNALS)
-  /* USG systems forget handlers when they are used;
-     must reestablish each time */
-  signal (SIGINT, interrupt_signal);
-  signal (SIGQUIT, interrupt_signal);
-#endif /* USG */
-
   SIGNAL_THREAD_CHECK (signalnum);
 
   /* See if we have an active terminal on our controlling tty. */
diff --git a/src/process.c b/src/process.c
index 53cc42f223e..5d2d64e3ddc 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1878,13 +1878,7 @@ create_process (process, new_argv, current_dir)
 #ifdef AIX
   struct sigaction sighup_action;
 #endif
-#else /* !POSIX_SIGNALS */
-#if 0
-#ifdef SIGCHLD
-  SIGTYPE (*sigchld)();
-#endif
-#endif /* 0 */
-#endif /* !POSIX_SIGNALS */
+#endif /* POSIX_SIGNALS */
   /* Use volatile to protect variables from being clobbered by longjmp.  */
   volatile int forkin, forkout;
   volatile int pty_flag = 0;
@@ -2008,14 +2002,9 @@ create_process (process, new_argv, current_dir)
   sigprocmask (SIG_BLOCK, &blocked, &procmask);
 #else /* !POSIX_SIGNALS */
 #ifdef SIGCHLD
-#if defined (BSD_SYSTEM) || defined (HPUX)
+#if defined (BSD_SYSTEM)
   sigsetmask (sigmask (SIGCHLD));
-#else /* ordinary USG */
-#if 0
-  sigchld_deferred = 0;
-  sigchld = signal (SIGCHLD, create_process_sigchld);
-#endif
-#endif /* ordinary USG */
+#endif /* BSD_SYSTEM */
 #endif /* SIGCHLD */
 #endif /* !POSIX_SIGNALS */
 
@@ -2172,13 +2161,9 @@ create_process (process, new_argv, current_dir)
         sigprocmask (SIG_SETMASK, &procmask, 0);
 #else /* !POSIX_SIGNALS */
 #ifdef SIGCHLD
-#if defined (BSD_SYSTEM) || defined (HPUX)
+#if defined (BSD_SYSTEM)
         sigsetmask (SIGEMPTYMASK);
-#else /* ordinary USG */
-#if 0
-        signal (SIGCHLD, sigchld);
-#endif
-#endif /* ordinary USG */
+#endif /* BSD_SYSTEM */
 #endif /* SIGCHLD */
 #endif /* !POSIX_SIGNALS */
 
@@ -2275,17 +2260,9 @@ create_process (process, new_argv, current_dir)
   sigprocmask (SIG_SETMASK, &procmask, 0);
 #else /* !POSIX_SIGNALS */
 #ifdef SIGCHLD
-#if defined (BSD_SYSTEM) || defined (HPUX)
+#if defined (BSD_SYSTEM)
   sigsetmask (SIGEMPTYMASK);
-#else /* ordinary USG */
-#if 0
-  signal (SIGCHLD, sigchld);
-  /* Now really handle any of these signals
-     that came in during this function.  */
-  if (sigchld_deferred)
-    kill (getpid (), SIGCHLD);
-#endif
-#endif /* ordinary USG */
+#endif /* BSD_SYSTEM */
 #endif /* SIGCHLD */
 #endif /* !POSIX_SIGNALS */
 
@@ -6704,11 +6681,6 @@ sigchld_handler (signo)
           /* PID == 0 means no processes found, PID == -1 means a real
              failure.  We have done all our job, so return.  */
 
-          /* USG systems forget handlers when they are used;
-             must reestablish each time */
-#if defined (USG) && !defined (POSIX_SIGNALS)
-          signal (signo, sigchld_handler);   /* WARNING - must come after wait3() */
-#endif
           errno = old_errno;
           return;
         }
@@ -6809,9 +6781,6 @@ sigchld_handler (signo)
 #if (defined WINDOWSNT \
      || (defined USG && !defined GNU_LINUX \
          && !(defined HPUX && defined WNOHANG)))
-#if defined (USG) && ! defined (POSIX_SIGNALS)
-      signal (signo, sigchld_handler);
-#endif
       errno = old_errno;
       return;
 #endif /* USG, but not HPUX with WNOHANG */
diff --git a/src/syssignal.h b/src/syssignal.h
index 64dacc671ce..f435d338594 100644
--- a/src/syssignal.h
+++ b/src/syssignal.h
@@ -88,38 +88,12 @@ sigset_t sys_sigsetmask P_ ((sigset_t new_mask));
 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
 
 #else /* ! defined (POSIX_SIGNALS) */
-#ifdef USG5_4
-
-extern SIGMASKTYPE sigprocmask_set;
-
-#ifndef sigblock
-#define sigblock(sig)                                   \
-     (sigprocmask_set = SIGEMPTYMASK | (sig),           \
-      sigprocmask (SIG_BLOCK, &sigprocmask_set, NULL))
-#endif
-
-#ifndef sigunblock
-#define sigunblock(sig)                                         \
-     (sigprocmask_set = SIGFULLMASK & ~(sig),                   \
-      sigprocmask (SIG_SETMASK, &sigprocmask_set, NULL))
-#endif
-
-#else
-#ifdef USG
-
-#ifndef sigunblock
-#define sigunblock(sig)
-#endif
-
-#else
 
 #ifndef sigunblock
 #define sigunblock(SIG) \
 { SIGMASKTYPE omask = sigblock (SIGEMPTYMASK); sigsetmask (omask & ~SIG); }
 #endif
 
-#endif /* ! defined (USG) */
-#endif /* ! defined (USG5_4) */
 #endif /* ! defined (POSIX_SIGNALS) */
 
 #ifndef SIGMASKTYPE