/* trap.c -- Not the trap command, but useful functions for manipulating
those objects. The trap command is in builtins/trap.def. */
-/* Copyright (C) 1987-2009 Free Software Foundation, Inc.
+/* Copyright (C) 1987-2015 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
#include "bashintl.h"
+#include <signal.h>
+
#include "trap.h"
#include "shell.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
assumes this. */
static int sigmodes[BASH_NSIG];
-static void free_trap_command __P((int));
-static void change_signal __P((int, char *));
+static void free_trap_command (int);
+static void change_signal (int, char *);
-static void get_original_signal __P((int));
+static int _run_trap_internal (int, char *);
-static int _run_trap_internal __P((int, char *));
+static void free_trap_string (int);
+static void reset_signal (int);
+static void restore_signal (int);
+static void reset_or_restore_signal_handlers (sh_resetsig_func_t *);
-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 *));
+static void trap_if_untrapped (int, char *);
/* 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 volatile int from_return_trap;
+
extern char *this_command_name;
extern sh_builtin_func_t *this_shell_builtin;
extern procenv_t wait_intr_buf;
+extern int wait_intr_flag;
extern int return_catch_flag, return_catch_value;
extern int subshell_level;
extern WORD_LIST *subst_assign_varlist;
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
+ executed when that signal is received. 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. */
/* The (trapped) signal received while executing in the `wait' builtin */
int wait_signal_received;
-/* A value which can never be the target of a trap handler. */
-#define IMPOSSIBLE_TRAP_HANDLER (SigHandler *)initialize_traps
+int trapped_signal_received;
#define GETORIGSIG(sig) \
do { \
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)
{
pending_traps[i] = 0;
trap_list[i] = (char *)DEFAULT_SIG;
- sigmodes[i] = SIG_INHERITED;
+ sigmodes[i] = SIG_INHERITED; /* XXX - only set, not used */
original_signals[i] = IMPOSSIBLE_TRAP_HANDLER;
}
GETORIGSIG (SIGTERM);
sigmodes[SIGTERM] |= SIG_SPECIAL;
}
+
+ get_original_tty_job_signals ();
}
-#ifdef INCLUDE_UNUSED
+#ifdef DEBUG
/* Return a printable representation of the trap handler for SIG. */
static char *
trap_handler_string (sig)
if (name == 0 || name[0] == '\0')
continue;
- /* Check name without the SIG prefix first case sensitivly or
+ /* Check name without the SIG prefix first case sensitively or
insensitively depending on whether flags includes DSIG_NOCASE */
if (STREQN (name, "SIG", 3))
{
run_pending_traps ()
{
register int sig;
- int old_exit_value, *token_state;
+ int old_exit_value, x;
WORD_LIST *save_subst_varlist;
+ HASH_TABLE *save_tempenv;
+ sh_parser_state_t pstate;
+#if defined (ARRAY_VARS)
+ ARRAY *ps;
+#endif
if (catch_flag == 0) /* simple optimization */
return;
- catch_flag = 0;
+ if (running_trap > 0)
+ {
+#if defined (DEBUG)
+ internal_warning ("run_pending_traps: recursive invocation while running trap for signal %d", running_trap-1);
+#endif
+#if defined (SIGWINCH)
+ if (running_trap == SIGWINCH+1 && pending_traps[SIGWINCH])
+ return; /* no recursive SIGWINCH trap invocations */
+#else
+ ;
+#endif
+ }
+
+ catch_flag = trapped_signal_received = 0;
/* Preserve $? when running trap. */
- old_exit_value = last_command_exit_value;
+ trap_saved_exit_value = old_exit_value = last_command_exit_value;
+#if defined (ARRAY_VARS)
+ ps = save_pipestatus_array ();
+#endif
for (sig = 1; sig < NSIG; sig++)
{
while (pending_traps[sig]--) instead of the if statement. */
if (pending_traps[sig])
{
-#if defined (HAVE_POSIX_SIGNALS)
- sigset_t set, oset;
+ if (running_trap == sig+1)
+ /*continue*/;
- sigemptyset (&set);
- sigemptyset (&oset);
-
- sigaddset (&set, sig);
- sigprocmask (SIG_BLOCK, &set, &oset);
-#else
-# if defined (HAVE_BSD_SIGNALS)
- int oldmask = sigblock (sigmask (sig));
-# endif
-#endif /* HAVE_POSIX_SIGNALS */
+ running_trap = sig + 1;
if (sig == SIGINT)
{
- run_interrupt_trap ();
+ pending_traps[sig] = 0; /* XXX */
+ run_interrupt_trap (0);
CLRINTERRUPT;
}
#if defined (JOB_CONTROL) && defined (SIGCHLD)
trap_list[SIGCHLD] != (char *)IMPOSSIBLE_TRAP_HANDLER &&
(sigmodes[SIGCHLD] & SIG_INPROGRESS) == 0)
{
- run_sigchld_trap (pending_traps[sig]); /* use as counter */
+ sigmodes[SIGCHLD] |= SIG_INPROGRESS;
+ x = pending_traps[sig];
+ pending_traps[sig] = 0;
+ run_sigchld_trap (x); /* use as counter */
+ running_trap = 0;
+ sigmodes[SIGCHLD] &= ~SIG_INPROGRESS;
+ /* continue here rather than reset pending_traps[SIGCHLD] below in
+ case there are recursive calls to run_pending_traps and children
+ have been reaped while run_sigchld_trap was running. */
+ continue;
+ }
+ 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. */
+ running_trap = 0;
+ /* want to leave pending_traps[SIGCHLD] alone here */
+ continue; /* XXX */
+ }
+ else if (sig == SIGCHLD && (sigmodes[SIGCHLD] & SIG_INPROGRESS))
+ {
+ /* whoops -- print warning? */
+ running_trap = 0; /* XXX */
+ /* want to leave pending_traps[SIGCHLD] alone here */
+ continue;
}
#endif
else if (trap_list[sig] == (char *)DEFAULT_SIG ||
}
else
{
- token_state = save_token_state ();
+ /* XXX - should we use save_parser_state/restore_parser_state? */
+ save_parser_state (&pstate);
save_subst_varlist = subst_assign_varlist;
subst_assign_varlist = 0;
+ save_tempenv = temporary_env;
+ temporary_env = 0; /* traps should not run with temporary env */
- parse_and_execute (savestring (trap_list[sig]), "trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE);
- restore_token_state (token_state);
- free (token_state);
+#if defined (JOB_CONTROL)
+ save_pipeline (1); /* XXX only provides one save level */
+#endif
+ /* XXX - set pending_traps[sig] = 0 here? */
+ pending_traps[sig] = 0;
+ evalstring (savestring (trap_list[sig]), "trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE);
+#if defined (JOB_CONTROL)
+ restore_pipeline (1);
+#endif
subst_assign_varlist = save_subst_varlist;
+ restore_parser_state (&pstate);
+ temporary_env = save_tempenv;
}
- pending_traps[sig] = 0;
-
-#if defined (HAVE_POSIX_SIGNALS)
- sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
-#else
-# if defined (HAVE_BSD_SIGNALS)
- sigsetmask (oldmask);
-# endif
-#endif /* POSIX_VERSION */
+ pending_traps[sig] = 0; /* XXX - move before evalstring? */
+ running_trap = 0;
}
}
+#if defined (ARRAY_VARS)
+ restore_pipestatus_array (ps);
+#endif
last_command_exit_value = old_exit_value;
}
catch_flag = 1;
pending_traps[sig]++;
+ trapped_signal_received = sig;
- if (interrupt_immediately && this_shell_builtin && (this_shell_builtin == wait_builtin))
+ if (this_shell_builtin && (this_shell_builtin == wait_builtin))
{
wait_signal_received = sig;
- longjmp (wait_intr_buf, 1);
+ if (interrupt_immediately && wait_intr_flag)
+ sh_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 ();
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
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 */
+/* Set a trap for SIG only if SIG is not already trapped. */
+static inline void
+trap_if_untrapped (sig, command)
+ int sig;
+ char *command;
+{
+ if ((sigmodes[sig] & SIG_TRAPPED) == 0)
+ set_signal (sig, command);
+}
+
void
set_debug_trap (command)
char *command;
set_signal (DEBUG_TRAP, command);
}
+/* Separate function to call when functions and sourced files want to restore
+ the original version of the DEBUG trap before returning. Unless the -T
+ option is set, source and shell function execution save the old debug trap
+ and unset the trap. If the function or sourced file changes the DEBUG trap,
+ SIG_TRAPPED will be set and we don't bother restoring the original trap string.
+ This is used by both functions and the source builtin. */
+void
+maybe_set_debug_trap (command)
+ char *command;
+{
+ trap_if_untrapped (DEBUG_TRAP, command);
+}
+
void
set_error_trap (command)
char *command;
set_signal (ERROR_TRAP, command);
}
+void
+maybe_set_error_trap (command)
+ char *command;
+{
+ trap_if_untrapped (ERROR_TRAP, command);
+}
+
void
set_return_trap (command)
char *command;
set_signal (RETURN_TRAP, command);
}
+void
+maybe_set_return_trap (command)
+ char *command;
+{
+ trap_if_untrapped (RETURN_TRAP, command);
+}
+
#ifdef INCLUDE_UNUSED
void
set_sigint_trap (command)
int sig;
char *string;
{
+ sigset_t set, oset;
+
if (SPECIAL_TRAP (sig))
{
change_signal (sig, savestring (string));
environment in which it is safe to do so. */
if ((sigmodes[sig] & SIG_NO_TRAP) == 0)
{
- set_signal_handler (sig, SIG_IGN);
+ 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));
sigmodes[sig] |= SIG_CHANGED;
}
-static void
+void
get_original_signal (sig)
int sig;
{
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
return;
/* If we aren't trapping this signal, don't bother doing anything else. */
- if ((sigmodes[sig] & SIG_TRAPPED) == 0)
+ /* We special-case SIGCHLD and IMPOSSIBLE_TRAP_HANDLER (see above) as a
+ sentinel to determine whether or not disposition is reset to the default
+ while the trap handler is executing. */
+ if (((sigmodes[sig] & SIG_TRAPPED) == 0) &&
+ (sig != SIGCHLD || (sigmodes[sig] & SIG_INPROGRESS) == 0 || trap_list[sig] != (char *)IMPOSSIBLE_TRAP_HANDLER))
return;
/* Only change the signal handler for SIG if it allows it. */
{
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
retval = trap_saved_exit_value;
running_trap = 1;
- code = setjmp (top_level);
+ 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 (return_catch);
+ function_code = setjmp_nosigs (return_catch);
if (code == 0 && function_code == 0)
{
retval = trap_saved_exit_value;
running_trap = 0;
+#if defined (ARRAY_VARS)
+ array_dispose (ps);
+#endif
+
return retval;
}
+#if defined (ARRAY_VARS)
+ restore_pipestatus_array (ps);
+#endif
return (trap_saved_exit_value);
}
sigmodes[sig] &= ~(SIG_INPROGRESS|SIG_CHANGED);
}
+#define RECURSIVE_SIG(s) (SPECIAL_TRAP(s) == 0)
+
/* 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
{
char *trap_command, *old_trap;
int trap_exit_value, *token_state;
- int save_return_catch_flag, function_code, flags;
+ volatile int save_return_catch_flag, function_code, top_level_code, old_int;
+ int flags;
procenv_t save_return_catch;
WORD_LIST *save_subst_varlist;
+ HASH_TABLE *save_tempenv;
+ sh_parser_state_t pstate;
+#if defined (ARRAY_VARS)
+ ARRAY *ps;
+#endif
trap_exit_value = function_code = 0;
+ trap_saved_exit_value = last_command_exit_value;
/* 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) &&
+#if 0
+ /* Uncomment this to allow some special signals to recursively execute
+ trap handlers. */
+ (RECURSIVE_SIG (sig) || (sigmodes[sig] & SIG_INPROGRESS) == 0))
+#else
((sigmodes[sig] & SIG_INPROGRESS) == 0))
+#endif
{
old_trap = trap_list[sig];
sigmodes[sig] |= SIG_INPROGRESS;
trap_command = savestring (old_trap);
running_trap = sig + 1;
- trap_saved_exit_value = last_command_exit_value;
- token_state = save_token_state ();
+ old_int = interrupt_state; /* temporarily suppress pending interrupts */
+ CLRINTERRUPT;
+
+#if defined (ARRAY_VARS)
+ ps = save_pipestatus_array ();
+#endif
+
+ save_parser_state (&pstate);
save_subst_varlist = subst_assign_varlist;
subst_assign_varlist = 0;
+ save_tempenv = temporary_env;
+ temporary_env = 0; /* traps should not run with temporary env */
+
+#if defined (JOB_CONTROL)
+ if (sig != DEBUG_TRAP) /* run_debug_trap does this */
+ save_pipeline (1); /* XXX only provides one save level */
+#endif
/* 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 (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);
+ {
+ parse_and_execute (trap_command, tag, flags);
+ trap_exit_value = last_command_exit_value;
+ }
+ else
+ trap_exit_value = return_catch_value;
- restore_token_state (token_state);
- free (token_state);
+#if defined (JOB_CONTROL)
+ if (sig != DEBUG_TRAP) /* run_debug_trap does this */
+ restore_pipeline (1);
+#endif
subst_assign_varlist = save_subst_varlist;
+ restore_parser_state (&pstate);
- trap_exit_value = last_command_exit_value;
- last_command_exit_value = trap_saved_exit_value;
- running_trap = 0;
+#if defined (ARRAY_VARS)
+ restore_pipestatus_array (ps);
+#endif
+
+ temporary_env = save_tempenv;
sigmodes[sig] &= ~SIG_INPROGRESS;
+ running_trap = 0;
+ interrupt_state = old_int;
if (sigmodes[sig] & SIG_CHANGED)
{
return_catch_value = trap_exit_value;
COPY_PROCENV (save_return_catch, return_catch);
if (function_code)
- longjmp (return_catch, 1);
+ {
+#if 0
+ from_return_trap = sig == RETURN_TRAP;
+#endif
+ sh_longjmp (return_catch, 1);
+ }
}
}
if (debugging_mode && trap_exit_value == 2 && return_catch_flag)
{
return_catch_value = trap_exit_value;
- longjmp (return_catch, 1);
+ sh_longjmp (return_catch, 1);
}
#endif
}
/* 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_interrupt_trap (will_throw)
+ int will_throw; /* from throw_to_top_level? */
{
+ if (will_throw && running_trap > 0)
+ run_trap_cleanup (running_trap - 1);
_run_trap_internal (SIGINT, "interrupt trap");
}
-#ifdef INCLUDE_UNUSED
/* 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. */
+ 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++)
- free_trap_string (i);
- trap_list[DEBUG_TRAP] = trap_list[EXIT_TRAP] = trap_list[ERROR_TRAP] = trap_list[RETURN_TRAP] = (char *)NULL;
+ for (i = 0; i < NSIG; i++)
+ {
+ if (trap_list[i] != (char *)IGNORE_SIG)
+ free_trap_string (i);
+ }
+ for (i = NSIG; i < BASH_NSIG; i++)
+ {
+ /* Don't free the trap string if the subshell inherited the trap */
+ if ((sigmodes[i] & SIG_TRAPPED) == 0)
+ {
+ free_trap_string (i);
+ trap_list[i] = (char *)NULL;
+ }
+ }
}
/* Free a trap command string associated with SIG without changing signal
change_signal (sig, (char *)DEFAULT_SIG);
sigmodes[sig] &= ~SIG_TRAPPED;
}
-#endif
-/* Reset the handler for SIG to the original value. */
+/* Reset the handler for SIG to the original value but leave the trap string
+ in place. */
static void
reset_signal (sig)
int sig;
}
else if (sigmodes[i] & SIG_SPECIAL)
(*reset) (i);
+ pending_traps[i] = 0; /* XXX */
}
/* Command substitution and other child processes don't inherit the
}
/* Reset trapped signals to their original values, but don't free the
- trap strings. Called by the command substitution code. */
+ trap strings. Called by the command substitution code and other places
+ that create a "subshell environment". */
void
reset_signal_handlers ()
{
}
/* If a trap handler exists for signal SIG, then call it; otherwise just
- return failure. */
+ return failure. Returns 1 if it called the trap handler. */
int
maybe_call_trap_handler (sig)
int sig;
switch (sig)
{
case SIGINT:
- run_interrupt_trap ();
+ run_interrupt_trap (0);
break;
case EXIT_TRAP:
run_exit_trap ();
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_IGNORED);
}
+int
+signal_is_hard_ignored (sig)
+ int sig;
+{
+ return (sigmodes[sig] & SIG_HARD_IGNORE);
+}
+
void
-set_signal_ignored (sig)
+set_signal_hard_ignored (sig)
int sig;
{
sigmodes[sig] |= SIG_HARD_IGNORE;
original_signals[sig] = SIG_IGN;
}
+void
+set_signal_ignored (sig)
+ int sig;
+{
+ original_signals[sig] = SIG_IGN;
+}
+
int
signal_in_progress (sig)
int sig;
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