less uses a correct raceless signal method of indicating signal events in

a volatile sig_atomic_t variable, and then processing events in the mainloop.
But only one variable was used for 3 signals, with |= bit operations which
are signal interruptable!  Rewrite the code to use 3 independent variables
and cleanup how the mainloop observes indications.
ok schwarze

15 files changed, 57 insertions, 61 deletions

diff --git a/usr.bin/less/ch.c b/usr.bin/less/ch.c
index 6c4bae2df63..1a679767a42 100644
--- a/usr.bin/less/ch.c
+++ b/usr.bin/less/ch.c
@@ -122,7 +122,6 @@ static int ch_ungotchar = -1;
 static int maxbufs = -1;
 
 extern int autobuf;
-extern volatile sig_atomic_t sigs;
 extern int secure;
 extern int screen_trashed;
 extern int follow_mode;
@@ -304,7 +303,7 @@ read_more:
 				}
 			}
 		}
-		if (sigs)
+		if (any_sigs())
 			return (EOI);
 	}
 
@@ -361,7 +360,7 @@ end_logfile(void)
 		tried = TRUE;
 		ierror("Finishing logfile", NULL);
 		while (ch_forw_get() != EOI)
-			if (ABORT_SIGS())
+			if (abort_sigs())
 				break;
 	}
 	close(logfile);
@@ -447,7 +446,7 @@ ch_seek(off_t pos)
 		while (ch_fpos < pos) {
 			if (ch_forw_get() == EOI)
 				return (1);
-			if (ABORT_SIGS())
+			if (abort_sigs())
 				return (1);
 		}
 		return (0);
@@ -482,7 +481,7 @@ ch_end_seek(void)
 	 * Do it the slow way: read till end of data.
 	 */
 	while (ch_forw_get() != EOI)
-		if (ABORT_SIGS())
+		if (abort_sigs())
 			return (1);
 	return (0);
 }
diff --git a/usr.bin/less/command.c b/usr.bin/less/command.c
index 2447887bcdd..4a90d74d185 100644
--- a/usr.bin/less/command.c
+++ b/usr.bin/less/command.c
@@ -19,7 +19,6 @@
 #include "position.h"
 
 extern int erase_char, erase2_char, kill_char;
-extern volatile sig_atomic_t sigs;
 extern int quit_if_one_screen;
 extern int less_is_more;
 extern int squished;
@@ -885,7 +884,7 @@ forw_loop(int until_hilite)
 	curr_len = ch_length();
 	highest_hilite = until_hilite ? curr_len : -1;
 	ignore_eoi = 1;
-	while (!sigs) {
+	while (!any_sigs()) {
 		if (until_hilite && highest_hilite > curr_len) {
 			ring_bell();
 			break;
@@ -900,7 +899,7 @@ forw_loop(int until_hilite)
 	 * This gets us back in "F mode" after processing
 	 * a non-abort signal (e.g. window-change).
 	 */
-	if (sigs && !ABORT_SIGS())
+	if (any_sigs() && !abort_sigs())
 		return (until_hilite ? A_F_UNTIL_HILITE : A_F_FOREVER);
 
 	return (A_NOACTION);
@@ -938,7 +937,7 @@ commands(void)
 		/*
 		 * See if any signals need processing.
 		 */
-		if (sigs) {
+		if (any_sigs()) {
 			psignals();
 			if (quitting)
 				quit(QUIT_SAVED_STATUS);
@@ -949,13 +948,13 @@ commands(void)
 		 */
 		cmd_reset();
 		prompt();
-		if (sigs)
+		if (any_sigs())
 			continue;
 		if (newaction == A_NOACTION)
 			c = getcc();
 
 again:
-		if (sigs)
+		if (any_sigs())
 			continue;
 
 		if (newaction != A_NOACTION) {
diff --git a/usr.bin/less/edit.c b/usr.bin/less/edit.c
index 8acd89231d0..eff4d28dcf7 100644
--- a/usr.bin/less/edit.c
+++ b/usr.bin/less/edit.c
@@ -21,7 +21,6 @@ extern char *every_first_cmd;
 extern int any_display;
 extern int force_open;
 extern int is_tty;
-extern volatile sig_atomic_t sigs;
 extern IFILE curr_ifile;
 extern IFILE old_ifile;
 extern struct scrpos initial_scrpos;
@@ -478,7 +477,7 @@ edit_istep(IFILE h, int n, int dir)
 			 */
 			return (1);
 		}
-		if (ABORT_SIGS()) {
+		if (abort_sigs()) {
 			/*
 			 * Interrupt breaks out, if we're in a long
 			 * list of files that can't be opened.
diff --git a/usr.bin/less/forwback.c b/usr.bin/less/forwback.c
index bc31a5ea279..023e93ec985 100644
--- a/usr.bin/less/forwback.c
+++ b/usr.bin/less/forwback.c
@@ -22,7 +22,6 @@ int squished;
 int no_back_scroll = 0;
 int forw_prompt;
 
-extern volatile sig_atomic_t sigs;
 extern int top_scroll;
 extern int quiet;
 extern int sc_width, sc_height;
diff --git a/usr.bin/less/input.c b/usr.bin/less/input.c
index dd5f622e07c..18ce8a93341 100644
--- a/usr.bin/less/input.c
+++ b/usr.bin/less/input.c
@@ -25,7 +25,6 @@ extern int squeeze;
 extern int chopline;
 extern int hshift;
 extern int quit_if_one_screen;
-extern volatile sig_atomic_t sigs;
 extern int ignore_eoi;
 extern int status_col;
 extern off_t start_attnpos;
@@ -75,7 +74,7 @@ get_forw_line:
 	 */
 	base_pos = curr_pos;
 	for (;;) {
-		if (ABORT_SIGS()) {
+		if (abort_sigs()) {
 			null_line();
 			return (-1);
 		}
@@ -97,7 +96,7 @@ get_forw_line:
 	(void) ch_seek(base_pos);
 	new_pos = base_pos;
 	while (new_pos < curr_pos) {
-		if (ABORT_SIGS()) {
+		if (abort_sigs()) {
 			null_line();
 			return (-1);
 		}
@@ -128,7 +127,7 @@ get_forw_line:
 	 * Read each character in the line and append to the line buffer.
 	 */
 	for (;;) {
-		if (ABORT_SIGS()) {
+		if (abort_sigs()) {
 			null_line();
 			return (-1);
 		}
@@ -160,7 +159,7 @@ get_forw_line:
 			 */
 			if (chopline || hshift > 0) {
 				do {
-					if (ABORT_SIGS()) {
+					if (abort_sigs()) {
 						null_line();
 						return (-1);
 					}
@@ -199,7 +198,7 @@ get_forw_line:
 		 * and pretend it is the one which we are returning.
 		 */
 		while ((c = ch_forw_get()) == '\n' || c == '\r')
-			if (ABORT_SIGS()) {
+			if (abort_sigs()) {
 				null_line();
 				return (-1);
 			}
@@ -255,7 +254,7 @@ get_back_line:
 			 * since we skipped them in forw_line().
 			 */
 			while ((c = ch_back_get()) == '\n' || c == '\r')
-				if (ABORT_SIGS()) {
+				if (abort_sigs()) {
 					null_line();
 					return (-1);
 				}
@@ -271,7 +270,7 @@ get_back_line:
 	 * Scan backwards until we hit the beginning of the line.
 	 */
 	for (;;) {
-		if (ABORT_SIGS()) {
+		if (abort_sigs()) {
 			null_line();
 			return (-1);
 		}
@@ -318,7 +317,7 @@ loop:
 
 	do {
 		c = ch_forw_get();
-		if (c == EOI || ABORT_SIGS()) {
+		if (c == EOI || abort_sigs()) {
 			null_line();
 			return (-1);
 		}
diff --git a/usr.bin/less/less.h b/usr.bin/less/less.h
index 3bd9e307201..259ade82ed9 100644
--- a/usr.bin/less/less.h
+++ b/usr.bin/less/less.h
@@ -151,10 +151,8 @@ struct textlist {
 #define	CONTROL(c)	((c)&037)
 #define	ESC		CONTROL('[')
 
-#define	S_INTERRUPT	01
-#define	S_STOP		02
-#define	S_WINCH		04
-#define	ABORT_SIGS()	(sigs & (S_INTERRUPT|S_STOP))
+extern int any_sigs(void);
+extern int abort_sigs(void);
 
 #define	QUIT_OK		0
 #define	QUIT_ERROR	1
diff --git a/usr.bin/less/line.c b/usr.bin/less/line.c
index 123353d2121..b76b067c875 100644
--- a/usr.bin/less/line.c
+++ b/usr.bin/less/line.c
@@ -46,7 +46,6 @@ static int attr_swidth(int);
 static int attr_ewidth(int);
 static int do_append(LWCHAR, char *, off_t);
 
-extern volatile sig_atomic_t sigs;
 extern int bs_mode;
 extern int linenums;
 extern int ctldisp;
@@ -685,7 +684,7 @@ pappend(char c, off_t pos)
 			mbc_buf[mbc_buf_index++] = c;
 			memset(&mbs, 0, sizeof(mbs));
 			sz = mbrtowc(&ch, mbc_buf, mbc_buf_index, &mbs);
-			
+
 			/* Incomplete UTF-8: wait for more bytes. */
 			if (sz == (size_t)-2)
 				return (0);
@@ -1034,7 +1033,7 @@ forw_raw_line(off_t curr_pos, char **linep, int *line_lenp)
 
 	n = 0;
 	for (;;) {
-		if (c == '\n' || c == EOI || ABORT_SIGS()) {
+		if (c == '\n' || c == EOI || abort_sigs()) {
 			new_pos = ch_tell();
 			break;
 		}
@@ -1077,7 +1076,7 @@ back_raw_line(off_t curr_pos, char **linep, int *line_lenp)
 	linebuf[--n] = '\0';
 	for (;;) {
 		c = ch_back_get();
-		if (c == '\n' || ABORT_SIGS()) {
+		if (c == '\n' || abort_sigs()) {
 			/*
 			 * This is the newline ending the previous line.
 			 * We have hit the beginning of the line.
diff --git a/usr.bin/less/linenum.c b/usr.bin/less/linenum.c
index 14a569cef1f..c76984078d6 100644
--- a/usr.bin/less/linenum.c
+++ b/usr.bin/less/linenum.c
@@ -69,7 +69,6 @@ static struct linenum_info pool[NPOOL];	/* The pool itself */
 static struct linenum_info *spare;	/* We always keep one spare entry */
 
 extern int linenums;
-extern volatile sig_atomic_t sigs;
 extern int sc_height;
 extern int screen_trashed;
 
@@ -308,7 +307,7 @@ find_linenum(off_t pos)
 			 * Allow a signal to abort this loop.
 			 */
 			cpos = forw_raw_line(cpos, NULL, NULL);
-			if (ABORT_SIGS()) {
+			if (abort_sigs()) {
 				abort_long();
 				return (0);
 			}
@@ -338,7 +337,7 @@ find_linenum(off_t pos)
 			 * Allow a signal to abort this loop.
 			 */
 			cpos = back_raw_line(cpos, NULL, NULL);
-			if (ABORT_SIGS()) {
+			if (abort_sigs()) {
 				abort_long();
 				return (0);
 			}
@@ -395,7 +394,7 @@ find_pos(off_t linenum)
 			 * Allow a signal to abort this loop.
 			 */
 			cpos = forw_raw_line(cpos, NULL, NULL);
-			if (ABORT_SIGS())
+			if (abort_sigs())
 				return (-1);
 			if (cpos == -1)
 				return (-1);
@@ -413,7 +412,7 @@ find_pos(off_t linenum)
 			 * Allow a signal to abort this loop.
 			 */
 			cpos = back_raw_line(cpos, (char **)NULL, (int *)NULL);
-			if (ABORT_SIGS())
+			if (abort_sigs())
 				return (-1);
 			if (cpos == -1)
 				return (-1);
diff --git a/usr.bin/less/os.c b/usr.bin/less/os.c
index 6eca5824fc3..e0be4af7097 100644
--- a/usr.bin/less/os.c
+++ b/usr.bin/less/os.c
@@ -27,7 +27,6 @@
 
 #include "less.h"
 
-extern volatile sig_atomic_t sigs;
 
 /*
  * Like read() system call, but is deliberately interruptible.
diff --git a/usr.bin/less/output.c b/usr.bin/less/output.c
index bafe48b8146..3dee60bab1a 100644
--- a/usr.bin/less/output.c
+++ b/usr.bin/less/output.c
@@ -17,7 +17,6 @@
 
 int errmsgs;	/* Count of messages displayed by error() */
 
-extern volatile sig_atomic_t sigs;
 extern int sc_width;
 extern int so_s_width, so_e_width;
 extern int screen_trashed;
@@ -37,7 +36,7 @@ put_line(void)
 	int i;
 	int a;
 
-	if (ABORT_SIGS()) {
+	if (abort_sigs()) {
 		/*
 		 * Don't output if a signal is pending.
 		 */
diff --git a/usr.bin/less/screen.c b/usr.bin/less/screen.c
index a794afc680b..893eb8def8c 100644
--- a/usr.bin/less/screen.c
+++ b/usr.bin/less/screen.c
@@ -81,7 +81,6 @@ extern int no_back_scroll;
 extern int swindow;
 extern int no_init;
 extern int no_keypad;
-extern volatile sig_atomic_t sigs;
 extern int wscroll;
 extern int screen_trashed;
 extern int tty;
diff --git a/usr.bin/less/search.c b/usr.bin/less/search.c
index 770ff0cf5b1..9d7613b665b 100644
--- a/usr.bin/less/search.c
+++ b/usr.bin/less/search.c
@@ -21,7 +21,6 @@
 #define	MINPOS(a, b)	(((a) < (b)) ? (a) : (b))
 #define	MAXPOS(a, b)	(((a) > (b)) ? (a) : (b))
 
-extern volatile sig_atomic_t sigs;
 extern int how_search;
 extern int caseless;
 extern int linenums;
@@ -677,7 +676,7 @@ search_range(off_t pos, off_t endpos, int search_type, int matches,
 		 * we hit end-of-file (or beginning-of-file if we're
 		 * going backwards), or until we hit the end position.
 		 */
-		if (ABORT_SIGS()) {
+		if (abort_sigs()) {
 			/*
 			 * A signal aborts the search.
 			 */
diff --git a/usr.bin/less/signal.c b/usr.bin/less/signal.c
index 5bf672c06bb..d2ae3319c76 100644
--- a/usr.bin/less/signal.c
+++ b/usr.bin/less/signal.c
@@ -22,9 +22,11 @@
 #include "less.h"
 
 /*
- * "sigs" contains bits indicating signals which need to be processed.
+ * signals which need to be processed.
  */
-volatile sig_atomic_t sigs;
+volatile sig_atomic_t signal_intr;
+volatile sig_atomic_t signal_stop;
+volatile sig_atomic_t signal_winch;
 
 extern int sc_width, sc_height;
 extern int screen_trashed;
@@ -39,7 +41,7 @@ extern long jump_sline_fraction;
 static void
 u_interrupt(int type)
 {
-	sigs |= S_INTERRUPT;
+	signal_intr = 1;
 }
 
 /*
@@ -48,7 +50,7 @@ u_interrupt(int type)
 static void
 stop(int type)
 {
-	sigs |= S_STOP;
+	signal_stop = 1;
 }
 
 /*
@@ -57,7 +59,7 @@ stop(int type)
 void
 sigwinch(int type)
 {
-	sigs |= S_WINCH;
+	signal_winch = 1;
 }
 
 /*
@@ -87,18 +89,12 @@ init_signals(int on)
 
 /*
  * Process any signals we have received.
- * A received signal cause a bit to be set in "sigs".
  */
 void
 psignals(void)
 {
-	int tsignals;
-
-	if ((tsignals = sigs) == 0)
-		return;
-	sigs = 0;
-
-	if (tsignals & S_STOP) {
+	if (signal_stop) {
+		signal_stop = 0;
 		/*
 		 * Clean up the terminal.
 		 */
@@ -120,9 +116,10 @@ psignals(void)
 		raw_mode(1);
 		init();
 		screen_trashed = 1;
-		tsignals |= S_WINCH;
+		signal_winch = 1;
 	}
-	if (tsignals & S_WINCH) {
+	if (signal_winch) {
+		signal_winch = 0;
 		int old_width, old_height;
 		/*
 		 * Re-execute scrsize() to read the new window size.
@@ -137,7 +134,8 @@ psignals(void)
 			screen_trashed = 1;
 		}
 	}
-	if (tsignals & S_INTERRUPT) {
+	if (signal_intr) {
+		signal_intr = 0;
 		ring_bell();
 		if (quit_on_intr)
 			quit(QUIT_INTERRUPT);
@@ -159,3 +157,16 @@ lsignal(int s, void (*a)(int))
 		return (SIG_ERR);
 	return (osa.sa_handler);
 }
+
+int
+any_sigs(void)
+{
+	return (signal_intr || signal_stop || signal_winch);
+}
+
+int
+abort_sigs(void)
+{
+	return (signal_intr || signal_stop);
+}
+
diff --git a/usr.bin/less/tags.c b/usr.bin/less/tags.c
index 9c7cba96883..ddc8d6541df 100644
--- a/usr.bin/less/tags.c
+++ b/usr.bin/less/tags.c
@@ -19,7 +19,6 @@ static int total;
 static int curseq;
 
 extern int linenums;
-extern volatile sig_atomic_t sigs;
 
 enum tag_result {
 	TAG_FOUND,
@@ -331,7 +330,7 @@ ctagsearch(void)
 		 * Get lines until we find a matching one or
 		 * until we hit end-of-file.
 		 */
-		if (ABORT_SIGS())
+		if (abort_sigs())
 			return (-1);
 
 		/*
diff --git a/usr.bin/less/ttyin.c b/usr.bin/less/ttyin.c
index 7511f44765a..cfe051365f5 100644
--- a/usr.bin/less/ttyin.c
+++ b/usr.bin/less/ttyin.c
@@ -16,7 +16,6 @@
 #include "less.h"
 
 int tty;
-extern volatile sig_atomic_t sigs;
 extern int utf_mode;
 
 /*