Major signal overhaul. We no longer longjmp all over the place.

Instead, routines responsible to gathering user input (or in some
cases outputting data) catch the signals and set flags as needed.
Because of this some handlers are install without the SA_RESTART
flag so syscalls are not restarted and we can check the flag.  All
signal handlers are now safe.

This should make the flow of control a bit more grokable but the
code is still ugly.

1 files changed, 24 insertions, 55 deletions

diff --git a/usr.bin/mail/lex.c b/usr.bin/mail/lex.c
index ff068f48529..a17a2d89b4a 100644
--- a/usr.bin/mail/lex.c
+++ b/usr.bin/mail/lex.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lex.c,v 1.24 2001/11/17 19:10:25 deraadt Exp $	*/
+/*	$OpenBSD: lex.c,v 1.25 2001/11/20 20:50:00 millert Exp $	*/
 /*	$NetBSD: lex.c,v 1.10 1997/05/17 19:55:13 pk Exp $	*/
 
 /*
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)lex.c	8.2 (Berkeley) 4/20/95";
 #else
-static char rcsid[] = "$OpenBSD: lex.c,v 1.24 2001/11/17 19:10:25 deraadt Exp $";
+static char rcsid[] = "$OpenBSD: lex.c,v 1.25 2001/11/20 20:50:00 millert Exp $";
 #endif
 #endif /* not lint */
 
@@ -209,7 +209,7 @@ incfile()
 
 
 int	*msgvec;
-int	reset_on_stop;			/* do a reset() if stopped */
+int	reset_on_stop;			/* reset prompt if stopped */
 
 /*
  * Interpret user commands one by one.  If standard input is not a tty,
@@ -218,20 +218,11 @@ int	reset_on_stop;			/* do a reset() if stopped */
 void
 commands()
 {
-	int n;
-	volatile int eofloop = 0;
+	int n, sig, *sigp;
+	int eofloop = 0;
 	char linebuf[LINESIZE];
 
-	if (!sourcing) {
-		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
-			(void)signal(SIGINT, intr);
-		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
-			(void)signal(SIGHUP, hangup);
-		(void)signal(SIGTSTP, stop);
-		(void)signal(SIGTTOU, stop);
-		(void)signal(SIGTTIN, stop);
-	}
-	setexit();
+	prompt:
 	for (;;) {
 		/*
 		 * Print the prompt, if needed.  Clear out
@@ -250,8 +241,24 @@ commands()
 		 * and handle end of file specially.
 		 */
 		n = 0;
+		sig = 0;
+		sigp = sourcing ? NULL : &sig;
 		for (;;) {
-			if (readline(input, &linebuf[n], LINESIZE - n) < 0) {
+			if (readline(input, &linebuf[n], LINESIZE - n, sigp) < 0) {
+				if (sig) {
+					if (sig == SIGINT)
+						dointr();
+					else if (sig == SIGHUP)
+						/* nothing to do? */
+						exit(1);
+					else {
+						/* Stopped by job control */
+						(void)kill(0, sig);
+						if (reset_on_stop)
+							reset_on_stop = 0;
+					}
+					goto prompt;
+				}
 				if (n == 0)
 					n = -1;
 				break;
@@ -597,10 +604,8 @@ isprefix(as1, as2)
 
 int	inithdr;			/* am printing startup headers */
 
-/*ARGSUSED*/
 void
-intr(s)
-	int s;
+dointr()
 {
 
 	noreset = 0;
@@ -617,42 +622,6 @@ intr(s)
 		image = -1;
 	}
 	fputs("Interrupt\n", stderr);
-	reset(0);
-}
-
-/*
- * When we wake up after ^Z, reprint the prompt.
- */
-void
-stop(s)
-	int s;
-{
-	sig_t old_action = signal(s, SIG_DFL);
-	sigset_t nset;
-
-	(void)sigemptyset(&nset);
-	(void)sigaddset(&nset, s);
-	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
-	(void)kill(0, s);
-	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
-	(void)signal(s, old_action);
-	if (reset_on_stop) {
-		reset_on_stop = 0;
-		reset(0);
-	}
-}
-
-/*
- * Branch here on hangup signal and simulate "exit".
- */
-/*ARGSUSED*/
-void
-hangup(s)
-	int s;
-{
-
-	/* nothing to do? */
-	exit(1);
 }
 
 /*