+++ /dev/null
-/* 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);
-}
projects / thirdparty / bash.git / blobdiff