remove global "jmp_buf die_jmp" from !FEATURE_PREFER_APPLETS builds

function                                             old     new   delta
xfunc_has_died                                         -      21     +21
sleep_much                                             -      12     +12
sleep10                                                -       9      +9
die_func                                               -       4      +4
fflush_stdout_and_exit                                35      36      +1
builtin_type                                         121     119      -2
die_sleep                                              4       -      -4
xfunc_die                                             60      24     -36
hush_main                                           1128    1011    -117
die_jmp                                              156       -    -156
------------------------------------------------------------------------------
(add/remove: 4/2 grow/shrink: 1/3 up/down: 47/-315)          Total: -268 bytes
   text	   data	    bss	    dec	    hex	filename
 939992	    992	  17652	 958636	  ea0ac	busybox_old
 939880	    992	  17496	 958368	  e9fa0	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 14 insertions, 11 deletions

diff --git a/shell/hush.c b/shell/hush.c
index f085ed3eb..0d107715f 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1479,10 +1479,11 @@ static sighandler_t install_sighandler(int sig, sighandler_t handler)
 
 #if ENABLE_HUSH_JOB
 
+static void xfunc_has_died(void);
 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
-# define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
+# define disable_restore_tty_pgrp_on_exit() (die_func = NULL)
 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
-# define enable_restore_tty_pgrp_on_exit()  (die_sleep = -1)
+# define enable_restore_tty_pgrp_on_exit()  (die_func = xfunc_has_died)
 
 /* Restores tty foreground process group, and exits.
  * May be called as signal handler for fatal signal
@@ -1587,6 +1588,15 @@ static void hush_exit(int exitcode)
 #endif
 }
 
+static void xfunc_has_died(void) NORETURN;
+static void xfunc_has_died(void)
+{
+        /* xfunc has failed! die die die */
+        /* no EXIT traps, this is an escape hatch! */
+        G.exiting = 1;
+        hush_exit(xfunc_error_retval);
+}
+
 
 //TODO: return a mask of ALL handled sigs?
 static int check_and_run_traps(void)
@@ -7866,12 +7876,7 @@ int hush_main(int argc, char **argv)
         /* Initialize some more globals to non-zero values */
         cmdedit_update_prompt();
 
-        if (setjmp(die_jmp)) {
-                /* xfunc has failed! die die die */
-                /* no EXIT traps, this is an escape hatch! */
-                G.exiting = 1;
-                hush_exit(xfunc_error_retval);
-        }
+        die_func = xfunc_has_died;
 
         /* Shell is non-interactive at first. We need to call
          * install_special_sighandlers() if we are going to execute "sh <script>",
@@ -8129,9 +8134,7 @@ int hush_main(int argc, char **argv)
                         /* Grab control of the terminal */
                         tcsetpgrp(G_interactive_fd, getpid());
                 }
-                /* -1 is special - makes xfuncs longjmp, not exit
-                 * (we reset die_sleep = 0 whereever we [v]fork) */
-                enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
+                enable_restore_tty_pgrp_on_exit();
 
 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
                 {