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Diffstat (limited to 'trap.c~')
| -rw-r--r-- | trap.c~ | 1209 |
1 files changed, 0 insertions, 1209 deletions
diff --git a/trap.c~ b/trap.c~ deleted file mode 100644 index b030747b..00000000 --- a/trap.c~ +++ /dev/null @@ -1,1209 +0,0 @@ -/* trap.c -- Not the trap command, but useful functions for manipulating - those objects. The trap command is in builtins/trap.def. */ - -/* Copyright (C) 1987-2013 Free Software Foundation, Inc. - - This file is part of GNU Bash, the Bourne Again SHell. - - Bash is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation, either version 3 of the License, or - (at your option) any later version. - - Bash is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with Bash. If not, see <http://www.gnu.org/licenses/>. -*/ - -#include "config.h" - -#if defined (HAVE_UNISTD_H) -# include <unistd.h> -#endif - -#include "bashtypes.h" -#include "bashansi.h" - -#include <stdio.h> -#include <errno.h> - -#include "bashintl.h" - -#include <signal.h> - -#include "trap.h" - -#include "shell.h" -#include "flags.h" -#include "input.h" /* for save_token_state, restore_token_state */ -#include "jobs.h" -#include "signames.h" -#include "builtins.h" -#include "builtins/common.h" -#include "builtins/builtext.h" - -#if defined (READLINE) -# include <readline/readline.h> -# include "bashline.h" -#endif - -#ifndef errno -extern int errno; -#endif - -/* Flags which describe the current handling state of a signal. */ -#define SIG_INHERITED 0x0 /* Value inherited from parent. */ -#define SIG_TRAPPED 0x1 /* Currently trapped. */ -#define SIG_HARD_IGNORE 0x2 /* Signal was ignored on shell entry. */ -#define SIG_SPECIAL 0x4 /* Treat this signal specially. */ -#define SIG_NO_TRAP 0x8 /* Signal cannot be trapped. */ -#define SIG_INPROGRESS 0x10 /* Signal handler currently executing. */ -#define SIG_CHANGED 0x20 /* Trap value changed in trap handler. */ -#define SIG_IGNORED 0x40 /* The signal is currently being ignored. */ - -#define SPECIAL_TRAP(s) ((s) == EXIT_TRAP || (s) == DEBUG_TRAP || (s) == ERROR_TRAP || (s) == RETURN_TRAP) - -/* An array of such flags, one for each signal, describing what the - shell will do with a signal. DEBUG_TRAP == NSIG; some code below - assumes this. */ -static int sigmodes[BASH_NSIG]; - -static void free_trap_command __P((int)); -static void change_signal __P((int, char *)); - -static void get_original_signal __P((int)); - -static int _run_trap_internal __P((int, char *)); - -static void free_trap_string __P((int)); -static void reset_signal __P((int)); -static void restore_signal __P((int)); -static void reset_or_restore_signal_handlers __P((sh_resetsig_func_t *)); - -/* Variables used here but defined in other files. */ -extern int last_command_exit_value; -extern int line_number; - -extern int sigalrm_seen; -extern procenv_t alrmbuf; - -extern char *this_command_name; -extern sh_builtin_func_t *this_shell_builtin; -extern procenv_t wait_intr_buf; -extern int return_catch_flag, return_catch_value; -extern int subshell_level; -extern WORD_LIST *subst_assign_varlist; - -/* The list of things to do originally, before we started trapping. */ -SigHandler *original_signals[NSIG]; - -/* For each signal, a slot for a string, which is a command to be - executed when that signal is recieved. The slot can also contain - DEFAULT_SIG, which means do whatever you were going to do before - you were so rudely interrupted, or IGNORE_SIG, which says ignore - this signal. */ -char *trap_list[BASH_NSIG]; - -/* A bitmap of signals received for which we have trap handlers. */ -int pending_traps[NSIG]; - -/* Set to the number of the signal we're running the trap for + 1. - Used in execute_cmd.c and builtins/common.c to clean up when - parse_and_execute does not return normally after executing the - trap command (e.g., when `return' is executed in the trap command). */ -int running_trap; - -/* Set to last_command_exit_value before running a trap. */ -int trap_saved_exit_value; - -/* The (trapped) signal received while executing in the `wait' builtin */ -int wait_signal_received; - -int trapped_signal_received; - -#define GETORIGSIG(sig) \ - do { \ - original_signals[sig] = (SigHandler *)set_signal_handler (sig, SIG_DFL); \ - set_signal_handler (sig, original_signals[sig]); \ - if (original_signals[sig] == SIG_IGN) \ - sigmodes[sig] |= SIG_HARD_IGNORE; \ - } while (0) - -#define SETORIGSIG(sig,handler) \ - do { \ - original_signals[sig] = handler; \ - if (original_signals[sig] == SIG_IGN) \ - sigmodes[sig] |= SIG_HARD_IGNORE; \ - } while (0) - -#define GET_ORIGINAL_SIGNAL(sig) \ - if (sig && sig < NSIG && original_signals[sig] == IMPOSSIBLE_TRAP_HANDLER) \ - GETORIGSIG(sig) - -void -initialize_traps () -{ - register int i; - - initialize_signames(); - - trap_list[EXIT_TRAP] = trap_list[DEBUG_TRAP] = trap_list[ERROR_TRAP] = trap_list[RETURN_TRAP] = (char *)NULL; - sigmodes[EXIT_TRAP] = sigmodes[DEBUG_TRAP] = sigmodes[ERROR_TRAP] = sigmodes[RETURN_TRAP] = SIG_INHERITED; - original_signals[EXIT_TRAP] = IMPOSSIBLE_TRAP_HANDLER; - - for (i = 1; i < NSIG; i++) - { - pending_traps[i] = 0; - trap_list[i] = (char *)DEFAULT_SIG; - sigmodes[i] = SIG_INHERITED; /* XXX - only set, not used */ - original_signals[i] = IMPOSSIBLE_TRAP_HANDLER; - } - - /* Show which signals are treated specially by the shell. */ -#if defined (SIGCHLD) - GETORIGSIG (SIGCHLD); - sigmodes[SIGCHLD] |= (SIG_SPECIAL | SIG_NO_TRAP); -#endif /* SIGCHLD */ - - GETORIGSIG (SIGINT); - sigmodes[SIGINT] |= SIG_SPECIAL; - -#if defined (__BEOS__) - /* BeOS sets SIGINT to SIG_IGN! */ - original_signals[SIGINT] = SIG_DFL; - sigmodes[SIGINT] &= ~SIG_HARD_IGNORE; -#endif - - GETORIGSIG (SIGQUIT); - sigmodes[SIGQUIT] |= SIG_SPECIAL; - - if (interactive) - { - GETORIGSIG (SIGTERM); - sigmodes[SIGTERM] |= SIG_SPECIAL; - } -} - -#ifdef DEBUG -/* Return a printable representation of the trap handler for SIG. */ -static char * -trap_handler_string (sig) - int sig; -{ - if (trap_list[sig] == (char *)DEFAULT_SIG) - return "DEFAULT_SIG"; - else if (trap_list[sig] == (char *)IGNORE_SIG) - return "IGNORE_SIG"; - else if (trap_list[sig] == (char *)IMPOSSIBLE_TRAP_HANDLER) - return "IMPOSSIBLE_TRAP_HANDLER"; - else if (trap_list[sig]) - return trap_list[sig]; - else - return "NULL"; -} -#endif - -/* Return the print name of this signal. */ -char * -signal_name (sig) - int sig; -{ - char *ret; - - /* on cygwin32, signal_names[sig] could be null */ - ret = (sig >= BASH_NSIG || sig < 0 || signal_names[sig] == NULL) - ? _("invalid signal number") - : signal_names[sig]; - - return ret; -} - -/* Turn a string into a signal number, or a number into - a signal number. If STRING is "2", "SIGINT", or "INT", - then (int)2 is returned. Return NO_SIG if STRING doesn't - contain a valid signal descriptor. */ -int -decode_signal (string, flags) - char *string; - int flags; -{ - intmax_t sig; - char *name; - - if (legal_number (string, &sig)) - return ((sig >= 0 && sig < NSIG) ? (int)sig : NO_SIG); - - /* A leading `SIG' may be omitted. */ - for (sig = 0; sig < BASH_NSIG; sig++) - { - name = signal_names[sig]; - if (name == 0 || name[0] == '\0') - continue; - - /* Check name without the SIG prefix first case sensitivly or - insensitively depending on whether flags includes DSIG_NOCASE */ - if (STREQN (name, "SIG", 3)) - { - name += 3; - - if ((flags & DSIG_NOCASE) && strcasecmp (string, name) == 0) - return ((int)sig); - else if ((flags & DSIG_NOCASE) == 0 && strcmp (string, name) == 0) - return ((int)sig); - /* If we can't use the `SIG' prefix to match, punt on this - name now. */ - else if ((flags & DSIG_SIGPREFIX) == 0) - continue; - } - - /* Check name with SIG prefix case sensitively or insensitively - depending on whether flags includes DSIG_NOCASE */ - name = signal_names[sig]; - if ((flags & DSIG_NOCASE) && strcasecmp (string, name) == 0) - return ((int)sig); - else if ((flags & DSIG_NOCASE) == 0 && strcmp (string, name) == 0) - return ((int)sig); - } - - return (NO_SIG); -} - -/* Non-zero when we catch a trapped signal. */ -static int catch_flag; - -void -run_pending_traps () -{ - register int sig; - int old_exit_value, *token_state; - WORD_LIST *save_subst_varlist; -#if defined (ARRAY_VARS) - ARRAY *ps; -#endif - - if (catch_flag == 0) /* simple optimization */ - return; - - catch_flag = trapped_signal_received = 0; - - /* Preserve $? when running trap. */ - old_exit_value = last_command_exit_value; -#if defined (ARRAY_VARS) - ps = save_pipestatus_array (); -#endif - - for (sig = 1; sig < NSIG; sig++) - { - /* XXX this could be made into a counter by using - while (pending_traps[sig]--) instead of the if statement. */ - if (pending_traps[sig]) - { - sigset_t set, oset; - - BLOCK_SIGNAL (sig, set, oset); - - if (sig == SIGINT) - { - run_interrupt_trap (); - CLRINTERRUPT; - } -#if defined (JOB_CONTROL) && defined (SIGCHLD) - else if (sig == SIGCHLD && - trap_list[SIGCHLD] != (char *)IMPOSSIBLE_TRAP_HANDLER && - (sigmodes[SIGCHLD] & SIG_INPROGRESS) == 0) - { - sigmodes[SIGCHLD] |= SIG_INPROGRESS; - run_sigchld_trap (pending_traps[sig]); /* use as counter */ - sigmodes[SIGCHLD] &= ~SIG_INPROGRESS; - } - else if (sig == SIGCHLD && - trap_list[SIGCHLD] == (char *)IMPOSSIBLE_TRAP_HANDLER && - (sigmodes[SIGCHLD] & SIG_INPROGRESS) != 0) - { - /* This can happen when run_pending_traps is called while - running a SIGCHLD trap handler. */ - UNBLOCK_SIGNAL (oset); - continue; /* XXX */ - } -#endif - else if (trap_list[sig] == (char *)DEFAULT_SIG || - trap_list[sig] == (char *)IGNORE_SIG || - trap_list[sig] == (char *)IMPOSSIBLE_TRAP_HANDLER) - { - /* This is possible due to a race condition. Say a bash - process has SIGTERM trapped. A subshell is spawned - using { list; } & and the parent does something and kills - the subshell with SIGTERM. It's possible for the subshell - to set pending_traps[SIGTERM] to 1 before the code in - execute_cmd.c eventually calls restore_original_signals - to reset the SIGTERM signal handler in the subshell. The - next time run_pending_traps is called, pending_traps[SIGTERM] - will be 1, but the trap handler in trap_list[SIGTERM] will - be invalid (probably DEFAULT_SIG, but it could be IGNORE_SIG). - Unless we catch this, the subshell will dump core when - trap_list[SIGTERM] == DEFAULT_SIG, because DEFAULT_SIG is - usually 0x0. */ - internal_warning (_("run_pending_traps: bad value in trap_list[%d]: %p"), - sig, trap_list[sig]); - if (trap_list[sig] == (char *)DEFAULT_SIG) - { - internal_warning (_("run_pending_traps: signal handler is SIG_DFL, resending %d (%s) to myself"), sig, signal_name (sig)); - kill (getpid (), sig); - } - } - else - { - token_state = save_token_state (); - save_subst_varlist = subst_assign_varlist; - subst_assign_varlist = 0; - - evalstring (savestring (trap_list[sig]), "trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE); - restore_token_state (token_state); - free (token_state); - - subst_assign_varlist = save_subst_varlist; - } - - pending_traps[sig] = 0; - - UNBLOCK_SIGNAL (oset); - } - } - -#if defined (ARRAY_VARS) - restore_pipestatus_array (ps); -#endif - last_command_exit_value = old_exit_value; -} - -sighandler -trap_handler (sig) - int sig; -{ - int oerrno; - - if ((sigmodes[sig] & SIG_TRAPPED) == 0) - { -#if defined (DEBUG) - internal_warning ("trap_handler: signal %d: signal not trapped", sig); -#endif - SIGRETURN (0); - } - - if ((sig >= NSIG) || - (trap_list[sig] == (char *)DEFAULT_SIG) || - (trap_list[sig] == (char *)IGNORE_SIG)) - programming_error (_("trap_handler: bad signal %d"), sig); - else - { - oerrno = errno; -#if defined (MUST_REINSTALL_SIGHANDLERS) -# if defined (JOB_CONTROL) && defined (SIGCHLD) - if (sig != SIGCHLD) -# endif /* JOB_CONTROL && SIGCHLD */ - set_signal_handler (sig, trap_handler); -#endif /* MUST_REINSTALL_SIGHANDLERS */ - - catch_flag = 1; - pending_traps[sig]++; - - trapped_signal_received = sig; - - if (this_shell_builtin && (this_shell_builtin == wait_builtin)) - { - wait_signal_received = sig; - if (interrupt_immediately) - longjmp (wait_intr_buf, 1); - } - -#if defined (READLINE) - /* Set the event hook so readline will call it after the signal handlers - finish executing, so if this interrupted character input we can get - quick response. */ - if (RL_ISSTATE (RL_STATE_SIGHANDLER) && interrupt_immediately == 0) - bashline_set_event_hook (); -#endif - - if (interrupt_immediately) - run_pending_traps (); - - errno = oerrno; - } - - SIGRETURN (0); -} - -int -first_pending_trap () -{ - register int i; - - for (i = 1; i < NSIG; i++) - if (pending_traps[i]) - return i; - return -1; -} - -int -any_signals_trapped () -{ - register int i; - - for (i = 1; i < NSIG; i++) - if (sigmodes[i] & SIG_TRAPPED) - return i; - return -1; -} - -void -check_signals () -{ - CHECK_ALRM; /* set by the read builtin */ - QUIT; -} - -/* Convenience functions the rest of the shell can use */ -void -check_signals_and_traps () -{ - check_signals (); - - run_pending_traps (); -} - -#if defined (JOB_CONTROL) && defined (SIGCHLD) - -#ifdef INCLUDE_UNUSED -/* Make COMMAND_STRING be executed when SIGCHLD is caught. */ -void -set_sigchld_trap (command_string) - char *command_string; -{ - set_signal (SIGCHLD, command_string); -} -#endif - -/* Make COMMAND_STRING be executed when SIGCHLD is caught iff SIGCHLD - is not already trapped. IMPOSSIBLE_TRAP_HANDLER is used as a sentinel - to make sure that a SIGCHLD trap handler run via run_sigchld_trap can - reset the disposition to the default and not have the original signal - accidentally restored, undoing the user's command. */ -void -maybe_set_sigchld_trap (command_string) - char *command_string; -{ - if ((sigmodes[SIGCHLD] & SIG_TRAPPED) == 0 && trap_list[SIGCHLD] == (char *)IMPOSSIBLE_TRAP_HANDLER) - set_signal (SIGCHLD, command_string); -} - -/* Temporarily set the SIGCHLD trap string to IMPOSSIBLE_TRAP_HANDLER. Used - as a sentinel in run_sigchld_trap and maybe_set_sigchld_trap to see whether - or not a SIGCHLD trap handler reset SIGCHLD disposition to the default. */ -void -set_impossible_sigchld_trap () -{ - restore_default_signal (SIGCHLD); - change_signal (SIGCHLD, (char *)IMPOSSIBLE_TRAP_HANDLER); - sigmodes[SIGCHLD] &= ~SIG_TRAPPED; /* maybe_set_sigchld_trap checks this */ -} - -/* Act as if we received SIGCHLD NCHILD times and increment - pending_traps[SIGCHLD] by that amount. This allows us to still run the - SIGCHLD trap once for each exited child. */ -void -queue_sigchld_trap (nchild) - int nchild; -{ - if (nchild > 0) - { - catch_flag = 1; - pending_traps[SIGCHLD] += nchild; - trapped_signal_received = SIGCHLD; - } -} -#endif /* JOB_CONTROL && SIGCHLD */ - -void -set_debug_trap (command) - char *command; -{ - set_signal (DEBUG_TRAP, command); -} - -void -set_error_trap (command) - char *command; -{ - set_signal (ERROR_TRAP, command); -} - -void -set_return_trap (command) - char *command; -{ - set_signal (RETURN_TRAP, command); -} - -#ifdef INCLUDE_UNUSED -void -set_sigint_trap (command) - char *command; -{ - set_signal (SIGINT, command); -} -#endif - -/* Reset the SIGINT handler so that subshells that are doing `shellsy' - things, like waiting for command substitution or executing commands - in explicit subshells ( ( cmd ) ), can catch interrupts properly. */ -SigHandler * -set_sigint_handler () -{ - if (sigmodes[SIGINT] & SIG_HARD_IGNORE) - return ((SigHandler *)SIG_IGN); - - else if (sigmodes[SIGINT] & SIG_IGNORED) - return ((SigHandler *)set_signal_handler (SIGINT, SIG_IGN)); /* XXX */ - - else if (sigmodes[SIGINT] & SIG_TRAPPED) - return ((SigHandler *)set_signal_handler (SIGINT, trap_handler)); - - /* The signal is not trapped, so set the handler to the shell's special - interrupt handler. */ - else if (interactive) /* XXX - was interactive_shell */ - return (set_signal_handler (SIGINT, sigint_sighandler)); - else - return (set_signal_handler (SIGINT, termsig_sighandler)); -} - -/* Return the correct handler for signal SIG according to the values in - sigmodes[SIG]. */ -SigHandler * -trap_to_sighandler (sig) - int sig; -{ - if (sigmodes[sig] & (SIG_IGNORED|SIG_HARD_IGNORE)) - return (SIG_IGN); - else if (sigmodes[sig] & SIG_TRAPPED) - return (trap_handler); - else - return (SIG_DFL); -} - -/* Set SIG to call STRING as a command. */ -void -set_signal (sig, string) - int sig; - char *string; -{ - sigset_t set, oset; - - if (SPECIAL_TRAP (sig)) - { - change_signal (sig, savestring (string)); - if (sig == EXIT_TRAP && interactive == 0) - initialize_terminating_signals (); - return; - } - - /* A signal ignored on entry to the shell cannot be trapped or reset, but - no error is reported when attempting to do so. -- Posix.2 */ - if (sigmodes[sig] & SIG_HARD_IGNORE) - return; - - /* Make sure we have original_signals[sig] if the signal has not yet - been trapped. */ - if ((sigmodes[sig] & SIG_TRAPPED) == 0) - { - /* If we aren't sure of the original value, check it. */ - if (original_signals[sig] == IMPOSSIBLE_TRAP_HANDLER) - GETORIGSIG (sig); - if (original_signals[sig] == SIG_IGN) - return; - } - - /* Only change the system signal handler if SIG_NO_TRAP is not set. - The trap command string is changed in either case. The shell signal - handlers for SIGINT and SIGCHLD run the user specified traps in an - environment in which it is safe to do so. */ - if ((sigmodes[sig] & SIG_NO_TRAP) == 0) - { - BLOCK_SIGNAL (sig, set, oset); - change_signal (sig, savestring (string)); - set_signal_handler (sig, trap_handler); - UNBLOCK_SIGNAL (oset); - } - else - change_signal (sig, savestring (string)); -} - -static void -free_trap_command (sig) - int sig; -{ - if ((sigmodes[sig] & SIG_TRAPPED) && trap_list[sig] && - (trap_list[sig] != (char *)IGNORE_SIG) && - (trap_list[sig] != (char *)DEFAULT_SIG) && - (trap_list[sig] != (char *)IMPOSSIBLE_TRAP_HANDLER)) - free (trap_list[sig]); -} - -/* If SIG has a string assigned to it, get rid of it. Then give it - VALUE. */ -static void -change_signal (sig, value) - int sig; - char *value; -{ - if ((sigmodes[sig] & SIG_INPROGRESS) == 0) - free_trap_command (sig); - trap_list[sig] = value; - - sigmodes[sig] |= SIG_TRAPPED; - if (value == (char *)IGNORE_SIG) - sigmodes[sig] |= SIG_IGNORED; - else - sigmodes[sig] &= ~SIG_IGNORED; - if (sigmodes[sig] & SIG_INPROGRESS) - sigmodes[sig] |= SIG_CHANGED; -} - -static void -get_original_signal (sig) - int sig; -{ - /* If we aren't sure the of the original value, then get it. */ - if (sig > 0 && sig < NSIG && original_signals[sig] == (SigHandler *)IMPOSSIBLE_TRAP_HANDLER) - GETORIGSIG (sig); -} - -void -get_all_original_signals () -{ - register int i; - - for (i = 1; i < NSIG; i++) - GET_ORIGINAL_SIGNAL (i); -} - -void -set_original_signal (sig, handler) - int sig; - SigHandler *handler; -{ - if (sig > 0 && sig < NSIG && original_signals[sig] == (SigHandler *)IMPOSSIBLE_TRAP_HANDLER) - SETORIGSIG (sig, handler); -} - -/* Restore the default action for SIG; i.e., the action the shell - would have taken before you used the trap command. This is called - from trap_builtin (), which takes care to restore the handlers for - the signals the shell treats specially. */ -void -restore_default_signal (sig) - int sig; -{ - if (SPECIAL_TRAP (sig)) - { - if ((sig != DEBUG_TRAP && sig != ERROR_TRAP && sig != RETURN_TRAP) || - (sigmodes[sig] & SIG_INPROGRESS) == 0) - free_trap_command (sig); - trap_list[sig] = (char *)NULL; - sigmodes[sig] &= ~SIG_TRAPPED; - if (sigmodes[sig] & SIG_INPROGRESS) - sigmodes[sig] |= SIG_CHANGED; - return; - } - - GET_ORIGINAL_SIGNAL (sig); - - /* A signal ignored on entry to the shell cannot be trapped or reset, but - no error is reported when attempting to do so. Thanks Posix.2. */ - if (sigmodes[sig] & SIG_HARD_IGNORE) - return; - - /* If we aren't trapping this signal, don't bother doing anything else. */ - if ((sigmodes[sig] & SIG_TRAPPED) == 0) - return; - - /* Only change the signal handler for SIG if it allows it. */ - if ((sigmodes[sig] & SIG_NO_TRAP) == 0) - set_signal_handler (sig, original_signals[sig]); - - /* Change the trap command in either case. */ - change_signal (sig, (char *)DEFAULT_SIG); - - /* Mark the signal as no longer trapped. */ - sigmodes[sig] &= ~SIG_TRAPPED; -} - -/* Make this signal be ignored. */ -void -ignore_signal (sig) - int sig; -{ - if (SPECIAL_TRAP (sig) && ((sigmodes[sig] & SIG_IGNORED) == 0)) - { - change_signal (sig, (char *)IGNORE_SIG); - return; - } - - GET_ORIGINAL_SIGNAL (sig); - - /* A signal ignored on entry to the shell cannot be trapped or reset. - No error is reported when the user attempts to do so. */ - if (sigmodes[sig] & SIG_HARD_IGNORE) - return; - - /* If already trapped and ignored, no change necessary. */ - if (sigmodes[sig] & SIG_IGNORED) - return; - - /* Only change the signal handler for SIG if it allows it. */ - if ((sigmodes[sig] & SIG_NO_TRAP) == 0) - set_signal_handler (sig, SIG_IGN); - - /* Change the trap command in either case. */ - change_signal (sig, (char *)IGNORE_SIG); -} - -/* Handle the calling of "trap 0". The only sticky situation is when - the command to be executed includes an "exit". This is why we have - to provide our own place for top_level to jump to. */ -int -run_exit_trap () -{ - char *trap_command; - int code, function_code, retval; -#if defined (ARRAY_VARS) - ARRAY *ps; -#endif - - trap_saved_exit_value = last_command_exit_value; -#if defined (ARRAY_VARS) - ps = save_pipestatus_array (); -#endif - function_code = 0; - - /* Run the trap only if signal 0 is trapped and not ignored, and we are not - currently running in the trap handler (call to exit in the list of - commands given to trap 0). */ - if ((sigmodes[EXIT_TRAP] & SIG_TRAPPED) && - (sigmodes[EXIT_TRAP] & (SIG_IGNORED|SIG_INPROGRESS)) == 0) - { - trap_command = savestring (trap_list[EXIT_TRAP]); - sigmodes[EXIT_TRAP] &= ~SIG_TRAPPED; - sigmodes[EXIT_TRAP] |= SIG_INPROGRESS; - - retval = trap_saved_exit_value; - running_trap = 1; - - code = setjmp_nosigs (top_level); - - /* If we're in a function, make sure return longjmps come here, too. */ - if (return_catch_flag) - function_code = setjmp_nosigs (return_catch); - - if (code == 0 && function_code == 0) - { - reset_parser (); - parse_and_execute (trap_command, "exit trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE); - } - else if (code == ERREXIT) - retval = last_command_exit_value; - else if (code == EXITPROG) - retval = last_command_exit_value; - else if (function_code != 0) - retval = return_catch_value; - else - retval = trap_saved_exit_value; - - running_trap = 0; - return retval; - } - -#if defined (ARRAY_VARS) - restore_pipestatus_array (ps); -#endif - return (trap_saved_exit_value); -} - -void -run_trap_cleanup (sig) - int sig; -{ - sigmodes[sig] &= ~(SIG_INPROGRESS|SIG_CHANGED); -} - -/* Run a trap command for SIG. SIG is one of the signals the shell treats - specially. Returns the exit status of the executed trap command list. */ -static int -_run_trap_internal (sig, tag) - int sig; - char *tag; -{ - char *trap_command, *old_trap; - int trap_exit_value, *token_state; - volatile int save_return_catch_flag, function_code; - int flags; - procenv_t save_return_catch; - WORD_LIST *save_subst_varlist; -#if defined (ARRAY_VARS) - ARRAY *ps; -#endif - - trap_exit_value = function_code = 0; - /* Run the trap only if SIG is trapped and not ignored, and we are not - currently executing in the trap handler. */ - if ((sigmodes[sig] & SIG_TRAPPED) && ((sigmodes[sig] & SIG_IGNORED) == 0) && - (trap_list[sig] != (char *)IMPOSSIBLE_TRAP_HANDLER) && - ((sigmodes[sig] & SIG_INPROGRESS) == 0)) - { - old_trap = trap_list[sig]; - sigmodes[sig] |= SIG_INPROGRESS; - sigmodes[sig] &= ~SIG_CHANGED; /* just to be sure */ - trap_command = savestring (old_trap); - - running_trap = sig + 1; - trap_saved_exit_value = last_command_exit_value; -#if defined (ARRAY_VARS) - ps = save_pipestatus_array (); -#endif - - token_state = save_token_state (); - save_subst_varlist = subst_assign_varlist; - subst_assign_varlist = 0; - - /* If we're in a function, make sure return longjmps come here, too. */ - save_return_catch_flag = return_catch_flag; - if (return_catch_flag) - { - COPY_PROCENV (return_catch, save_return_catch); - function_code = setjmp_nosigs (return_catch); - } - - flags = SEVAL_NONINT|SEVAL_NOHIST; - if (sig != DEBUG_TRAP && sig != RETURN_TRAP && sig != ERROR_TRAP) - flags |= SEVAL_RESETLINE; - if (function_code == 0) - parse_and_execute (trap_command, tag, flags); - - restore_token_state (token_state); - free (token_state); - - subst_assign_varlist = save_subst_varlist; - - trap_exit_value = last_command_exit_value; - last_command_exit_value = trap_saved_exit_value; -#if defined (ARRAY_VARS) - restore_pipestatus_array (ps); -#endif - running_trap = 0; - - sigmodes[sig] &= ~SIG_INPROGRESS; - - if (sigmodes[sig] & SIG_CHANGED) - { -#if 0 - /* Special traps like EXIT, DEBUG, RETURN are handled explicitly in - the places where they can be changed using unwind-protects. For - example, look at execute_cmd.c:execute_function(). */ - if (SPECIAL_TRAP (sig) == 0) -#endif - free (old_trap); - sigmodes[sig] &= ~SIG_CHANGED; - } - - if (save_return_catch_flag) - { - return_catch_flag = save_return_catch_flag; - return_catch_value = trap_exit_value; - COPY_PROCENV (save_return_catch, return_catch); - if (function_code) - longjmp (return_catch, 1); - } - } - - return trap_exit_value; -} - -int -run_debug_trap () -{ - int trap_exit_value; - pid_t save_pgrp; - int save_pipe[2]; - - /* XXX - question: should the DEBUG trap inherit the RETURN trap? */ - trap_exit_value = 0; - if ((sigmodes[DEBUG_TRAP] & SIG_TRAPPED) && ((sigmodes[DEBUG_TRAP] & SIG_IGNORED) == 0) && ((sigmodes[DEBUG_TRAP] & SIG_INPROGRESS) == 0)) - { -#if defined (JOB_CONTROL) - save_pgrp = pipeline_pgrp; - pipeline_pgrp = 0; - save_pipeline (1); -# if defined (PGRP_PIPE) - save_pgrp_pipe (save_pipe, 1); -# endif - stop_making_children (); -#endif - - trap_exit_value = _run_trap_internal (DEBUG_TRAP, "debug trap"); - -#if defined (JOB_CONTROL) - pipeline_pgrp = save_pgrp; - restore_pipeline (1); -# if defined (PGRP_PIPE) - close_pgrp_pipe (); - restore_pgrp_pipe (save_pipe); -# endif - if (pipeline_pgrp > 0) - give_terminal_to (pipeline_pgrp, 1); - notify_and_cleanup (); -#endif - -#if defined (DEBUGGER) - /* If we're in the debugger and the DEBUG trap returns 2 while we're in - a function or sourced script, we force a `return'. */ - if (debugging_mode && trap_exit_value == 2 && return_catch_flag) - { - return_catch_value = trap_exit_value; - longjmp (return_catch, 1); - } -#endif - } - return trap_exit_value; -} - -void -run_error_trap () -{ - if ((sigmodes[ERROR_TRAP] & SIG_TRAPPED) && ((sigmodes[ERROR_TRAP] & SIG_IGNORED) == 0) && (sigmodes[ERROR_TRAP] & SIG_INPROGRESS) == 0) - _run_trap_internal (ERROR_TRAP, "error trap"); -} - -void -run_return_trap () -{ - int old_exit_value; - -#if 0 - if ((sigmodes[DEBUG_TRAP] & SIG_TRAPPED) && (sigmodes[DEBUG_TRAP] & SIG_INPROGRESS)) - return; -#endif - - if ((sigmodes[RETURN_TRAP] & SIG_TRAPPED) && ((sigmodes[RETURN_TRAP] & SIG_IGNORED) == 0) && (sigmodes[RETURN_TRAP] & SIG_INPROGRESS) == 0) - { - old_exit_value = last_command_exit_value; - _run_trap_internal (RETURN_TRAP, "return trap"); - last_command_exit_value = old_exit_value; - } -} - -/* Run a trap set on SIGINT. This is called from throw_to_top_level (), and - declared here to localize the trap functions. */ -void -run_interrupt_trap () -{ - _run_trap_internal (SIGINT, "interrupt trap"); -} - -/* Free all the allocated strings in the list of traps and reset the trap - values to the default. Intended to be called from subshells that want - to complete work done by reset_signal_handlers upon execution of a - subsequent `trap' command that changes a signal's disposition. We need - to make sure that we duplicate the behavior of - reset_or_restore_signal_handlers and not change the disposition of signals - that are set to be ignored. */ -void -free_trap_strings () -{ - register int i; - - for (i = 0; i < BASH_NSIG; i++) - { - if (trap_list[i] != (char *)IGNORE_SIG) - free_trap_string (i); - } - trap_list[DEBUG_TRAP] = trap_list[EXIT_TRAP] = trap_list[ERROR_TRAP] = trap_list[RETURN_TRAP] = (char *)NULL; -} - -/* Free a trap command string associated with SIG without changing signal - disposition. Intended to be called from free_trap_strings() */ -static void -free_trap_string (sig) - int sig; -{ - change_signal (sig, (char *)DEFAULT_SIG); - sigmodes[sig] &= ~SIG_TRAPPED; -} - -/* Reset the handler for SIG to the original value but leave the trap string - in place. */ -static void -reset_signal (sig) - int sig; -{ - set_signal_handler (sig, original_signals[sig]); - sigmodes[sig] &= ~SIG_TRAPPED; -} - -/* Set the handler signal SIG to the original and free any trap - command associated with it. */ -static void -restore_signal (sig) - int sig; -{ - set_signal_handler (sig, original_signals[sig]); - change_signal (sig, (char *)DEFAULT_SIG); - sigmodes[sig] &= ~SIG_TRAPPED; -} - -static void -reset_or_restore_signal_handlers (reset) - sh_resetsig_func_t *reset; -{ - register int i; - - /* Take care of the exit trap first */ - if (sigmodes[EXIT_TRAP] & SIG_TRAPPED) - { - sigmodes[EXIT_TRAP] &= ~SIG_TRAPPED; - if (reset != reset_signal) - { - free_trap_command (EXIT_TRAP); - trap_list[EXIT_TRAP] = (char *)NULL; - } - } - - for (i = 1; i < NSIG; i++) - { - if (sigmodes[i] & SIG_TRAPPED) - { - if (trap_list[i] == (char *)IGNORE_SIG) - set_signal_handler (i, SIG_IGN); - else - (*reset) (i); - } - else if (sigmodes[i] & SIG_SPECIAL) - (*reset) (i); - } - - /* Command substitution and other child processes don't inherit the - debug, error, or return traps. If we're in the debugger, and the - `functrace' or `errtrace' options have been set, then let command - substitutions inherit them. Let command substitution inherit the - RETURN trap if we're in the debugger and tracing functions. */ - if (function_trace_mode == 0) - { - sigmodes[DEBUG_TRAP] &= ~SIG_TRAPPED; - sigmodes[RETURN_TRAP] &= ~SIG_TRAPPED; - } - if (error_trace_mode == 0) - sigmodes[ERROR_TRAP] &= ~SIG_TRAPPED; -} - -/* Reset trapped signals to their original values, but don't free the - trap strings. Called by the command substitution code and other places - that create a "subshell environment". */ -void -reset_signal_handlers () -{ - reset_or_restore_signal_handlers (reset_signal); -} - -/* Reset all trapped signals to their original values. Signals set to be - ignored with trap '' SIGNAL should be ignored, so we make sure that they - are. Called by child processes after they are forked. */ -void -restore_original_signals () -{ - reset_or_restore_signal_handlers (restore_signal); -} - -/* If a trap handler exists for signal SIG, then call it; otherwise just - return failure. Returns 1 if it called the trap handler. */ -int -maybe_call_trap_handler (sig) - int sig; -{ - /* Call the trap handler for SIG if the signal is trapped and not ignored. */ - if ((sigmodes[sig] & SIG_TRAPPED) && ((sigmodes[sig] & SIG_IGNORED) == 0)) - { - switch (sig) - { - case SIGINT: - run_interrupt_trap (); - break; - case EXIT_TRAP: - run_exit_trap (); - break; - case DEBUG_TRAP: - run_debug_trap (); - break; - case ERROR_TRAP: - run_error_trap (); - break; - default: - trap_handler (sig); - break; - } - return (1); - } - else - return (0); -} - -int -signal_is_trapped (sig) - int sig; -{ - return (sigmodes[sig] & SIG_TRAPPED); -} - -int -signal_is_pending (sig) - int sig; -{ - return (pending_traps[sig]); -} - -int -signal_is_special (sig) - int sig; -{ - return (sigmodes[sig] & SIG_SPECIAL); -} - -int -signal_is_ignored (sig) - int sig; -{ - return (sigmodes[sig] & SIG_IGNORED); -} - -int -signal_is_hard_ignored (sig) - int sig; -{ - return (sigmodes[sig] & SIG_HARD_IGNORE); -} - -void -set_signal_ignored (sig) - int sig; -{ - sigmodes[sig] |= SIG_HARD_IGNORE; - original_signals[sig] = SIG_IGN; -} - -int -signal_in_progress (sig) - int sig; -{ - return (sigmodes[sig] & SIG_INPROGRESS); -} |