Switch to C23 and use [[noreturn]] attribute port

The __dead attribute is not standard on FreeBSD (which uses __dead2
instead) or Linux. C23 provides the [[noreturn]] attribute, which
accomplishes the same thing in a portable manner. (C11 provides
_Noreturn/noreturn, but this is deprecated in C23. C23 also provides us
with memccpy(), which we can use to replace strlcpy() and strlcat(), so
we might as well make the jump.)

3 files changed, 8 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 49416f8..7ec12c6 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ MAN_DIR = $(PREFIX)/share/man/man6
 MAN = rogue.6
 
 CC = cc
-CFLAGS = -std=c99 -O2 -Wall -Wextra -Wpedantic
+CFLAGS = -std=c23 -O2 -Wall -Wextra -Wpedantic
 CPPFLAGS = -DUNIX -DUNIX_SYSV -Dlint
 LDLIBS = -lcurses
 
diff --git a/rogue.h b/rogue.h
index b097bf2..35fc0c5 100644
--- a/rogue.h
+++ b/rogue.h
@@ -471,7 +471,7 @@ void	check_gold_seeker(object *);
 boolean	check_imitator(object *);
 void	check_message(void);
 int	check_up(void);
-void	clean_up(const char *) __dead;
+[[noreturn]] void clean_up(const char *);
 void	clear_level(void);
 void	cnfs(void);
 int	coin_toss(void);
@@ -488,7 +488,7 @@ void	drop(void);
 int	drop_check(void);
 void	eat(void);
 void	edit_opts(void);
-void	error_save(int) __dead;
+[[noreturn]] void	error_save(int);
 void	fight(boolean);
 boolean	flame_broil(object *);
 void	free_object(object *);
@@ -531,7 +531,7 @@ boolean	is_direction(short, short *);
 boolean	is_passable(int, int);
 boolean	is_vowel(short);
 void	kick_into_pack(void);
-void	killed_by(const object *, short) __dead;
+[[noreturn]] void	killed_by(const object *, short);
 long	lget_number(const char *);
 void	light_passage(int, int);
 void	light_up_room(int);
@@ -539,7 +539,7 @@ boolean	m_confuse(object *);
 void	make_level(void);
 void	make_scroll_titles(void);
 boolean	md_df(const char *);
-void	md_exit(int) __dead;
+[[noreturn]] void	md_exit(int);
 void	md_gct(struct rogue_time *);
 int	md_get_file_id(const char *);
 void	md_gfmt(const char *, struct rogue_time *);
@@ -580,7 +580,7 @@ void	put_mons(void);
 void	put_objects(void);
 void	put_on_ring(void);
 void	put_player(short);
-void	put_scores(const object *, short) __dead;
+[[noreturn]] void	put_scores(const object *, short);
 void	put_stairs(void);
 void	quaff(void);
 void	quit(boolean);
@@ -636,7 +636,7 @@ void	wake_up(object *);
 void	wanderer(void);
 void	wear(void);
 void	wield(void);
-void	win(void) __dead;
+[[noreturn]] void	win(void);
 void	wizardize(void);
 long	xxx(boolean);
 void	xxxx(char *, short);
diff --git a/score.c b/score.c
index 6a8a24d..723eaed 100644
--- a/score.c
+++ b/score.c
@@ -63,7 +63,7 @@ static void center(short, const char *);
 static int get_value(const object *);
 static void id_all(void);
 static void sell_pack(void);
-static void sf_error(void) __dead;
+[[noreturn]] static void sf_error(void);
 
 void
 killed_by(const object *monster, short other)