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hush: fix EXIT trap recursion case; check redirection failures

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function                                             old     new   delta                          
run_pipe                                            1299    1328     +29                          
hush_exit                                             90     102     +12                          
hush_main                                           1172    1179      +7                          
run_list                                            1226    1225      -1                          
------------------------------------------------------------------------------                    
(add/remove: 0/0 grow/shrink: 3/1 up/down: 48/-1)              Total: 47 bytes
This commit is contained in:
Denis Vlasenko 2009-04-09 13:43:11 +00:00
parent f81e8dbc74
commit efea9d2819
5 changed files with 74 additions and 30 deletions
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76
shell/hush.c
View File

@ -513,6 +513,7 @@ struct globals {
smallint flag_break_continue;
#endif
smallint fake_mode;
smallint exiting; /* used to prevent EXIT trap recursion */
/* These four support $?, $#, and $1 */
smalluint last_exitcode;
/* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
@ -851,7 +852,7 @@ static void free_strings(char **strings)
*
* Trap handlers will execute even within trap handlers. (right?)
*
* User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
* User trap handlers are forgotten when subshell ("(cmd)") is entered.
*
* If job control is off, backgrounded commands ("cmd &")
* have SIGINT, SIGQUIT set to SIG_IGN.
@ -905,7 +906,7 @@ static void free_strings(char **strings)
* set bit in blocked_set (even if 'cmd' is '')
* after [v]fork, if we plan to be a shell:
* nothing for {} child shell (say, "true | { true; true; } | true")
* unset all traps if () shell. [TODO]
* unset all traps if () shell.
* after [v]fork, if we plan to exec:
* POSIX says pending signal mask is cleared in child - no need to clear it.
* Restore blocked signal set to one inherited by shell just prior to exec.
@ -1005,9 +1006,13 @@ static void sigexit(int sig)
static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
if (G.traps && G.traps[0] && G.traps[0][0]) {
char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
//TODO: do we need to prevent recursion?
if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
/* Prevent recursion:
* trap "echo Hi; exit" EXIT; exit
*/
char *argv[] = { NULL, G.traps[0], NULL };
G.traps[0] = NULL;
G.exiting = 1;
builtin_eval(argv);
free(argv[1]);
}
@ -2350,7 +2355,6 @@ static void setup_heredoc(struct redir_struct *redir)
* and stderr if they are redirected. */
static int setup_redirects(struct command *prog, int squirrel[])
{
//TODO: no callers ever check return value - ?!
int openfd, mode;
struct redir_struct *redir;
@ -2952,11 +2956,13 @@ static int run_pipe(struct pipe *pi)
#endif
/* { list } */
debug_printf("non-subshell group\n");
setup_redirects(command, squirrel);
debug_printf_exec(": run_list\n");
rcode = run_list(command->group) & 0xff;
rcode = 1; /* exitcode if redir failed */
if (setup_redirects(command, squirrel) == 0) {
debug_printf_exec(": run_list\n");
rcode = run_list(command->group) & 0xff;
debug_printf_exec("run_pipe return %d\n", rcode);
}
restore_redirects(squirrel);
debug_printf_exec("run_pipe return %d\n", rcode);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
}
@ -2970,7 +2976,7 @@ static int run_pipe(struct pipe *pi)
if (argv[command->assignment_cnt] == NULL) {
/* Assignments, but no command */
/* Ensure redirects take effect. Try "a=t >file" */
setup_redirects(command, squirrel);
rcode = setup_redirects(command, squirrel);
restore_redirects(squirrel);
/* Set shell variables */
while (*argv) {
@ -2983,7 +2989,8 @@ static int run_pipe(struct pipe *pi)
/* Do we need to flag set_local_var() errors?
* "assignment to readonly var" and "putenv error"
*/
return EXIT_SUCCESS;
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
}
/* Expand the rest into (possibly) many strings each */
@ -2994,8 +3001,7 @@ static int run_pipe(struct pipe *pi)
continue;
if (x->function == builtin_exec && argv_expanded[1] == NULL) {
debug_printf("exec with redirects only\n");
setup_redirects(command, NULL);
rcode = EXIT_SUCCESS;
rcode = setup_redirects(command, NULL);
goto clean_up_and_ret1;
}
debug_printf("builtin inline %s\n", argv_expanded[0]);
@ -3003,12 +3009,14 @@ static int run_pipe(struct pipe *pi)
* This is perfect for work that comes after exec().
* Is it really safe for inline use? Experimentally,
* things seem to work with glibc. */
setup_redirects(command, squirrel);
new_env = expand_assignments(argv, command->assignment_cnt);
old_env = putenv_all_and_save_old(new_env);
debug_printf_exec(": builtin '%s' '%s'...\n",
x->cmd, argv_expanded[1]);
rcode = x->function(argv_expanded) & 0xff;
rcode = setup_redirects(command, squirrel);
if (rcode == 0) {
new_env = expand_assignments(argv, command->assignment_cnt);
old_env = putenv_all_and_save_old(new_env);
debug_printf_exec(": builtin '%s' '%s'...\n",
x->cmd, argv_expanded[1]);
rcode = x->function(argv_expanded) & 0xff;
}
#if ENABLE_FEATURE_SH_STANDALONE
clean_up_and_ret:
#endif
@ -3027,13 +3035,15 @@ static int run_pipe(struct pipe *pi)
#if ENABLE_FEATURE_SH_STANDALONE
i = find_applet_by_name(argv_expanded[0]);
if (i >= 0 && APPLET_IS_NOFORK(i)) {
setup_redirects(command, squirrel);
save_nofork_data(&G.nofork_save);
new_env = expand_assignments(argv, command->assignment_cnt);
old_env = putenv_all_and_save_old(new_env);
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
rcode = setup_redirects(command, squirrel);
if (rcode == 0) {
save_nofork_data(&G.nofork_save);
new_env = expand_assignments(argv, command->assignment_cnt);
old_env = putenv_all_and_save_old(new_env);
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
argv_expanded[0], argv_expanded[1]);
rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
}
goto clean_up_and_ret;
}
#endif
@ -3095,7 +3105,8 @@ static int run_pipe(struct pipe *pi)
close(pipefds[0]); /* read end */
/* Like bash, explicit redirects override pipes,
* and the pipe fd is available for dup'ing. */
setup_redirects(command, NULL);
if (setup_redirects(command, NULL))
_exit(1);
/* Restore default handlers just prior to exec */
/*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
@ -3324,9 +3335,9 @@ static int run_list(struct pipe *pi)
//// /* ctrl-Z handler will store pid etc in pi */
//// G.toplevel_list = pi;
//// G.ctrl_z_flag = 0;
////#if ENABLE_FEATURE_SH_STANDALONE
//// G.nofork_save.saved = 0; /* in case we will run a nofork later */
////#endif
#if ENABLE_FEATURE_SH_STANDALONE
G.nofork_save.saved = 0; /* in case we will run a nofork later */
#endif
//// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
//// signal(SIGINT, handler_ctrl_c);
}
@ -5680,6 +5691,8 @@ int hush_main(int argc, char **argv)
enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
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);
}
} else if (!signal_mask_is_inited) {
@ -5907,6 +5920,9 @@ static int builtin_exit(char **argv)
//puts("exit"); /* bash does it */
// TODO: warn if we have background jobs: "There are stopped jobs"
// On second consecutive 'exit', exit anyway.
// perhaps use G.exiting = -1 as indicator "last cmd was exit"
/* note: EXIT trap is run by hush_exit */
if (*++argv == NULL)
hush_exit(G.last_exitcode);
/* mimic bash: exit 123abc == exit 255 + error msg */

1
shell/hush_test/hush-misc/exit1.right Normal file
View File

@ -0,0 +1 @@
Once

4
shell/hush_test/hush-misc/exit1.tests Executable file
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@ -0,0 +1,4 @@
trap "echo Not shown" EXIT
(exit) # must be silent
trap "echo Once; exit" EXIT
{ exit; }

14
shell/hush_test/hush-misc/redir3.right Normal file
View File

@ -0,0 +1,14 @@
hush: can't open '/does/not/exist': No such file or directory
One:1
hush: can't open '/cant/be/created': No such file or directory
One:1
Ok
hush: can't open '/cant/be/created': No such file or directory
Zero:0
hush: can't open '/cant/be/created': No such file or directory
One:1
hush: can't open '/cant/be/created': No such file or directory
One:1
hush: can't open '/cant/be/created': No such file or directory
Zero:0
Done

9
shell/hush_test/hush-misc/redir3.tests Executable file
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@ -0,0 +1,9 @@
echo Error >/does/not/exist; echo One:$?
t=BAD
t=Ok >>/cant/be/created; echo One:$?
echo $t
! >/cant/be/created; echo Zero:$?
exec >/cant/be/created; echo One:$?
exec /bin/true >/cant/be/created; echo One:$?
! exec /bin/true >/cant/be/created; echo Zero:$?
echo Done