Initial revision

1 files changed, 748 insertions, 0 deletions

diff --git a/Src/signals.c b/Src/signals.c
new file mode 100644
index 000000000..5dc19dd22
--- /dev/null
+++ b/Src/signals.c
@@ -0,0 +1,748 @@
+/*
+ * signals.c - signals handling code
+ *
+ * This file is part of zsh, the Z shell.
+ *
+ * Copyright (c) 1992-1997 Paul Falstad
+ * All rights reserved.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and to distribute modified versions of this software for any
+ * purpose, provided that the above copyright notice and the following
+ * two paragraphs appear in all copies of this software.
+ *
+ * In no event shall Paul Falstad or the Zsh Development Group be liable
+ * to any party for direct, indirect, special, incidental, or consequential
+ * damages arising out of the use of this software and its documentation,
+ * even if Paul Falstad and the Zsh Development Group have been advised of
+ * the possibility of such damage.
+ *
+ * Paul Falstad and the Zsh Development Group specifically disclaim any
+ * warranties, including, but not limited to, the implied warranties of
+ * merchantability and fitness for a particular purpose.  The software
+ * provided hereunder is on an "as is" basis, and Paul Falstad and the
+ * Zsh Development Group have no obligation to provide maintenance,
+ * support, updates, enhancements, or modifications.
+ *
+ */
+
+#include "zsh.mdh"
+#include "signals.pro"
+ 
+/* Array describing the state of each signal: an element contains *
+ * 0 for the default action or some ZSIG_* flags ored together.   */
+
+/**/
+int sigtrapped[VSIGCOUNT];
+
+/* trap functions for each signal */
+
+/**/
+List sigfuncs[VSIGCOUNT];
+
+/* Variables used by signal queueing */
+
+/**/
+int queueing_enabled, queue_front, queue_rear;
+/**/
+int signal_queue[MAX_QUEUE_SIZE];
+/**/
+sigset_t signal_mask_queue[MAX_QUEUE_SIZE];
+
+/* This is only used on machines that don't understand signal sets.  *
+ * On SYSV machines this will represent the signals that are blocked *
+ * (held) using sighold.  On machines which can't block signals at   *
+ * all, we will simulate this by ignoring them and remembering them  *
+ * in this variable.                                                 */
+#if !defined(POSIX_SIGNALS) && !defined(BSD_SIGNALS)
+static sigset_t blocked_set;
+#endif
+
+#ifdef POSIX_SIGNALS
+# define signal_jmp_buf       sigjmp_buf
+# define signal_setjmp(b)     sigsetjmp((b),1)
+# define signal_longjmp(b,n)  siglongjmp((b),(n))
+#else
+# define signal_jmp_buf       jmp_buf
+# define signal_setjmp(b)     setjmp(b)
+# define signal_longjmp(b,n)  longjmp((b),(n))
+#endif
+ 
+#ifdef NO_SIGNAL_BLOCKING
+# define signal_process(sig)  signal_ignore(sig)
+# define signal_reset(sig)    install_handler(sig)
+#else
+# define signal_process(sig)  ;
+# define signal_reset(sig)    ;
+#endif
+
+/* Install signal handler for given signal.           *
+ * If possible, we want to make sure that interrupted *
+ * system calls are not restarted.                    */
+
+/**/
+void
+install_handler(int sig)
+{
+#ifdef POSIX_SIGNALS
+    struct sigaction act;
+ 
+    act.sa_handler = (SIGNAL_HANDTYPE) handler;
+    sigemptyset(&act.sa_mask);        /* only block sig while in handler */
+    act.sa_flags = 0;
+# ifdef SA_INTERRUPT                  /* SunOS 4.x */
+    if (interact)
+        act.sa_flags |= SA_INTERRUPT; /* make sure system calls are not restarted */
+# endif
+    sigaction(sig, &act, (struct sigaction *)NULL);
+#else
+# ifdef BSD_SIGNALS
+    struct sigvec vec;
+ 
+    vec.sv_handler = (SIGNAL_HANDTYPE) handler;
+    vec.sv_mask = sigmask(sig);    /* mask out this signal while in handler    */
+#  ifdef SV_INTERRUPT
+    vec.sv_flags = SV_INTERRUPT;   /* make sure system calls are not restarted */
+#  endif
+    sigvec(sig, &vec, (struct sigvec *)NULL);
+# else
+#  ifdef SYSV_SIGNALS
+    /* we want sigset rather than signal because it will   *
+     * block sig while in handler.  signal usually doesn't */
+    sigset(sig, handler);
+#  else  /* NO_SIGNAL_BLOCKING (bummer) */
+    signal(sig, handler);
+
+#  endif /* SYSV_SIGNALS  */
+# endif  /* BSD_SIGNALS   */
+#endif   /* POSIX_SIGNALS */
+}
+
+/* enable ^C interrupts */
+ 
+/**/
+void
+intr(void)
+{
+    if (interact)
+        install_handler(SIGINT);
+}
+
+#if 0
+/* disable ^C interrupts */
+ 
+/**/
+void
+nointr(void)
+{
+    if (interact)
+        signal_ignore(SIGINT);
+}
+#endif
+ 
+/* temporarily block ^C interrupts */
+ 
+/**/
+void
+holdintr(void)
+{
+    if (interact)
+        signal_block(signal_mask(SIGINT));
+}
+
+/* release ^C interrupts */
+ 
+/**/
+void
+noholdintr(void)
+{
+    if (interact)
+        signal_unblock(signal_mask(SIGINT));
+}
+ 
+/* create a signal mask containing *
+ * only the given signal           */
+ 
+/**/
+sigset_t
+signal_mask(int sig)
+{
+    sigset_t set;
+ 
+    sigemptyset(&set);
+    if (sig)
+        sigaddset(&set, sig);
+    return set;
+}
+
+/* Block the signals in the given signal *
+ * set. Return the old signal set.       */
+ 
+/**/
+sigset_t
+signal_block(sigset_t set)
+{
+    sigset_t oset;
+ 
+#ifdef POSIX_SIGNALS
+    sigprocmask(SIG_BLOCK, &set, &oset);
+#else
+# ifdef BSD_SIGNALS
+    oset = sigblock(set);
+# else
+#  ifdef SYSV_SIGNALS
+    int i;
+ 
+    oset = blocked_set;
+    for (i = 1; i <= NSIG; ++i) {
+        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
+            sigaddset(&blocked_set, i);
+            sighold(i);
+        }
+    }
+#  else  /* NO_SIGNAL_BLOCKING */
+/* We will just ignore signals if the system doesn't have *
+ * the ability to block them.                             */
+    int i;
+
+    oset = blocked_set;
+    for (i = 1; i <= NSIG; ++i) {
+        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
+            sigaddset(&blocked_set, i);
+            signal_ignore(i);
+        }
+   }
+#  endif /* SYSV_SIGNALS  */
+# endif  /* BSD_SIGNALS   */
+#endif   /* POSIX_SIGNALS */
+ 
+    return oset;
+}
+
+/* Unblock the signals in the given signal *
+ * set. Return the old signal set.         */
+
+/**/
+sigset_t
+signal_unblock(sigset_t set)
+{
+    sigset_t oset;
+ 
+#ifdef POSIX_SIGNALS
+    sigprocmask(SIG_UNBLOCK, &set, &oset);
+#else
+# ifdef BSD_SIGNALS
+    sigfillset(&oset);
+    oset = sigsetmask(oset);
+    sigsetmask(oset & ~set);
+# else
+#  ifdef SYSV_SIGNALS
+    int i;
+ 
+    oset = blocked_set;
+    for (i = 1; i <= NSIG; ++i) {
+        if (sigismember(&set, i) && sigismember(&blocked_set, i)) {
+            sigdelset(&blocked_set, i);
+            sigrelse(i);
+        }
+    }
+#  else  /* NO_SIGNAL_BLOCKING */
+/* On systems that can't block signals, we are just ignoring them.  So *
+ * to unblock signals, we just reenable the signal handler for them.   */
+    int i;
+
+    oset = blocked_set;
+    for (i = 1; i <= NSIG; ++i) {
+        if (sigismember(&set, i) && sigismember(&blocked_set, i)) {
+            sigdelset(&blocked_set, i);
+            install_handler(i);
+        }
+   }
+#  endif /* SYSV_SIGNALS  */
+# endif  /* BSD_SIGNALS   */
+#endif   /* POSIX_SIGNALS */
+ 
+    return oset;
+}
+
+/* set the process signal mask to *
+ * be the given signal mask       */
+
+/**/
+sigset_t
+signal_setmask(sigset_t set)
+{
+    sigset_t oset;
+ 
+#ifdef POSIX_SIGNALS
+    sigprocmask(SIG_SETMASK, &set, &oset);
+#else
+# ifdef BSD_SIGNALS
+    oset = sigsetmask(set);
+# else
+#  ifdef SYSV_SIGNALS
+    int i;
+ 
+    oset = blocked_set;
+    for (i = 1; i <= NSIG; ++i) {
+        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
+            sigaddset(&blocked_set, i);
+            sighold(i);
+        } else if (!sigismember(&set, i) && sigismember(&blocked_set, i)) {
+            sigdelset(&blocked_set, i);
+            sigrelse(i);
+        }
+    }
+#  else  /* NO_SIGNAL_BLOCKING */
+    int i;
+
+    oset = blocked_set;
+    for (i = 1; i < NSIG; ++i) {
+        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
+            sigaddset(&blocked_set, i);
+            signal_ignore(i);
+        } else if (!sigismember(&set, i) && sigismember(&blocked_set, i)) {
+            sigdelset(&blocked_set, i);
+            install_handler(i);
+        }
+    }
+#  endif /* SYSV_SIGNALS  */
+# endif  /* BSD_SIGNALS   */
+#endif   /* POSIX_SIGNALS */
+ 
+    return oset;
+}
+
+#if defined(NO_SIGNAL_BLOCKING)
+static int suspend_longjmp = 0;
+static signal_jmp_buf suspend_jmp_buf;
+#endif
+ 
+/**/
+int
+signal_suspend(int sig, int sig2)
+{
+    int ret;
+ 
+#ifdef POSIX_SIGNALS
+    sigset_t set;
+
+    sigfillset(&set);
+    sigdelset(&set, sig);
+    sigdelset(&set, SIGHUP);  /* still don't know why we add this? */
+    if (sig2)
+        sigdelset(&set, sig2);
+    ret = sigsuspend(&set);
+#else
+# ifdef BSD_SIGNALS
+    sigset_t set;
+
+    sigfillset(&set);
+    sigdelset(&set, sig);
+    if (sig2)
+      sigdelset(&set, sig2);
+    ret = sigpause(set);
+# else
+#  ifdef SYSV_SIGNALS
+    ret = sigpause(sig);
+
+#  else  /* NO_SIGNAL_BLOCKING */
+    /* need to use signal_longjmp to make this race-free *
+     * between the child_unblock() and pause()           */
+    if (signal_setjmp(suspend_jmp_buf) == 0) {
+        suspend_longjmp = 1;   /* we want to signal_longjmp after catching signal */
+        child_unblock();       /* do we need to unblock sig2 as well?             */
+        ret = pause();
+    }
+    suspend_longjmp = 0;       /* turn off using signal_longjmp since we are past *
+                                * the pause() function.                           */
+#  endif /* SYSV_SIGNALS  */
+# endif  /* BSD_SIGNALS   */
+#endif   /* POSIX_SIGNALS */
+ 
+    return ret;
+}
+
+/* What flavor of waitpid/wait3/wait shall we use? */
+ 
+#ifdef HAVE_WAITPID
+# define  WAIT(pid, statusp, options) waitpid(pid, statusp, options)
+#else
+# ifdef HAVE_WAIT3
+#  define WAIT(pid, statusp, options) wait3((void *) statusp, options, NULL)
+# else
+#  define WAIT(pid, statusp, options) wait(statusp)
+# endif
+#endif
+
+/* the signal handler */
+ 
+/**/
+RETSIGTYPE
+handler(int sig)
+{
+    sigset_t newmask, oldmask;
+
+#if defined(NO_SIGNAL_BLOCKING)
+    int do_jump;
+    signal_jmp_buf jump_to;
+#endif
+ 
+    signal_process(sig);
+ 
+    sigfillset(&newmask);
+    oldmask = signal_block(newmask);        /* Block all signals temporarily           */
+ 
+#if defined(NO_SIGNAL_BLOCKING)
+    do_jump = suspend_longjmp;              /* do we need to longjmp to signal_suspend */
+    suspend_longjmp = 0;                    /* In case a SIGCHLD somehow arrives       */
+
+    if (sig == SIGCHLD) {                   /* Traps can cause nested child_suspend()  */
+        if (do_jump)
+            jump_to = suspend_jmp_buf;      /* Copy suspend_jmp_buf                    */
+    }
+#endif
+
+    if (queueing_enabled) {           /* Are we queueing signals now?      */
+        int temp_rear = ++queue_rear % MAX_QUEUE_SIZE;
+
+	DPUTS(temp_rear == queue_front, "BUG: signal queue full");
+        if (temp_rear != queue_front) { /* Make sure it's not full (extremely unlikely) */
+            queue_rear = temp_rear;                  /* ok, not full, so add to queue   */
+            signal_queue[queue_rear] = sig;          /* save signal caught              */
+            signal_mask_queue[queue_rear] = oldmask; /* save current signal mask        */
+        }
+        signal_reset(sig);
+        return;
+    }
+ 
+    signal_setmask(oldmask);          /* Reset signal mask, signal traps ok now */
+ 
+    switch (sig) {
+    case SIGCHLD:
+
+	/* keep WAITING until no more child processes to reap */
+	for (;;)
+	  cont: {
+            int old_errno = errno; /* save the errno, since WAIT may change it */
+	    int status;
+	    Job jn;
+	    Process pn;
+            pid_t pid;
+	    pid_t *procsubpid = &cmdoutpid;
+	    int *procsubval = &cmdoutval;
+	    struct execstack *es = exstack;
+
+            pid = WAIT(-1, &status, WNOHANG|WUNTRACED);  /* reap the child process */
+
+            if (!pid)  /* no more children to reap */
+                break;
+
+	    /* check if child returned was from process substitution */
+	    for (;;) {
+		if (pid == *procsubpid) {
+		    *procsubpid = 0;
+		    if (WIFSIGNALED(status))
+			*procsubval = (0200 | WTERMSIG(status));
+		    else
+			*procsubval = WEXITSTATUS(status);
+		    times(&shtms);
+		    goto cont;
+		}
+		if (!es)
+		    break;
+		procsubpid = &es->cmdoutpid;
+		procsubval = &es->cmdoutval;
+		es = es->next;
+	    }
+
+	    /* check for WAIT error */
+            if (pid == -1) {
+                if (errno != ECHILD)
+                    zerr("wait failed: %e", NULL, errno);
+                errno = old_errno;    /* WAIT changed errno, so restore the original */
+                break;
+            }
+
+	    /* Find the process and job containing this pid and update it. */
+	    if (findproc(pid, &jn, &pn)) {
+		update_process(pn, status);
+		update_job(jn);
+	    } else {
+		/* If not found, update the shell record of time spent by
+		 * children in sub processes anyway:  otherwise, this
+		 * will get added on to the next found process that terminates.
+		 */
+		times(&shtms);
+	    }
+        }
+        break;
+ 
+    case SIGHUP:
+        if (sigtrapped[SIGHUP])
+            dotrap(SIGHUP);
+        else {
+            stopmsg = 1;
+            zexit(SIGHUP, 1);
+        }
+        break;
+ 
+    case SIGINT:
+        if (sigtrapped[SIGINT])
+            dotrap(SIGINT);
+        else {
+	    if ((isset(PRIVILEGED) || isset(RESTRICTED)) &&
+		isset(INTERACTIVE) && noerrexit < 0)
+		zexit(SIGINT, 1);
+            if (list_pipe || chline || simple_pline) {
+                breaks = loops;
+                errflag = 1;
+		inerrflush();
+            }
+        }
+        break;
+
+#ifdef SIGWINCH
+    case SIGWINCH:
+        adjustwinsize();  /* check window size and adjust */
+	if (sigtrapped[SIGWINCH])
+	    dotrap(SIGWINCH);
+        break;
+#endif
+
+    case SIGALRM:
+        if (sigtrapped[SIGALRM]) {
+	    int tmout;
+            dotrap(SIGALRM);
+            if ((tmout = getiparam("TMOUT")))
+                alarm(tmout);           /* reset the alarm */
+        } else {
+	    int idle = ttyidlegetfn(NULL);
+	    int tmout = getiparam("TMOUT");
+	    if (idle >= 0 && idle < tmout)
+		alarm(tmout - idle);
+	    else {
+		errflag = noerrs = 0;
+		zerr("timeout", NULL, 0);
+		errflag = 0;
+		stopmsg = 1;
+		zexit(SIGALRM, 1);
+	    }
+        }
+        break;
+ 
+    default:
+        dotrap(sig);
+        break;
+    }   /* end of switch(sig) */
+ 
+    signal_reset(sig);
+
+/* This is used to make signal_suspend() race-free */
+#if defined(NO_SIGNAL_BLOCKING)
+    if (do_jump)
+        signal_longjmp(jump_to, 1);
+#endif
+
+} /* handler */
+
+ 
+/* SIGHUP any jobs left running */
+ 
+/**/
+void
+killrunjobs(int from_signal)
+{
+    int i, killed = 0;
+ 
+    if (unset(HUP))
+        return;
+    for (i = 1; i < MAXJOB; i++)
+        if ((from_signal || i != thisjob) && (jobtab[i].stat & STAT_LOCKED) &&
+            !(jobtab[i].stat & STAT_NOPRINT) &&
+            !(jobtab[i].stat & STAT_STOPPED)) {
+            if (killpg(jobtab[i].gleader, SIGHUP) != -1)
+                killed++;
+        }
+    if (killed)
+        zerr("warning: %d jobs SIGHUPed", NULL, killed);
+}
+
+
+/* send a signal to a job (simply involves kill if monitoring is on) */
+ 
+/**/
+int
+killjb(Job jn, int sig)
+{
+    Process pn;
+    int err = 0;
+ 
+    if (jobbing) {
+        if (jn->stat & STAT_SUPERJOB) {
+            if (sig == SIGCONT) {
+                for (pn = jobtab[jn->other].procs; pn; pn = pn->next)
+                    kill(pn->pid, sig);
+ 
+                for (pn = jn->procs; pn->next; pn = pn->next)
+                    err = kill(pn->pid, sig);
+ 
+                return err;
+            }
+ 
+            killpg(jobtab[jn->other].gleader, sig);
+            return killpg(jn->gleader, sig);
+        }
+        else
+            return (killpg(jn->gleader, sig));
+    }
+    for (pn = jn->procs; pn; pn = pn->next)
+        if ((err = kill(pn->pid, sig)) == -1 && errno != ESRCH)
+            return -1;
+    return err;
+}
+
+/**/
+int
+settrap(int sig, List l)
+{
+    if (sig == -1)
+        return 1;
+    if (jobbing && (sig == SIGTTOU || sig == SIGTSTP || sig == SIGTTIN)) {
+        zerr("can't trap SIG%s in interactive shells", sigs[sig], 0);
+        return 1;
+    }
+    if (sigfuncs[sig])
+	unsettrap(sig);
+    sigfuncs[sig] = l;
+    if (!l) {
+	sigtrapped[sig] = ZSIG_IGNORED;
+        if (sig && sig <= SIGCOUNT &&
+#ifdef SIGWINCH
+            sig != SIGWINCH &&
+#endif
+            sig != SIGCHLD)
+            signal_ignore(sig);
+    } else {
+        sigtrapped[sig] = ZSIG_TRAPPED;
+        if (sig && sig <= SIGCOUNT &&
+#ifdef SIGWINCH
+            sig != SIGWINCH &&
+#endif
+            sig != SIGCHLD)
+            install_handler(sig);
+    }
+    return 0;
+}
+
+/**/
+void
+unsettrap(int sig)
+{
+    int trapped;
+
+    if (sig == -1 || !(trapped = sigtrapped[sig]) ||
+	(jobbing && (sig == SIGTTOU || sig == SIGTSTP || sig == SIGTTIN))) {
+        return;
+    }
+    sigtrapped[sig] = 0;
+    if (sig == SIGINT && interact) {
+	/* PWS 1995/05/16:  added test for interactive, also noholdintr() *
+	 * as subshells ignoring SIGINT have it blocked from delivery     */
+        intr();
+	noholdintr();
+    } else if (sig == SIGHUP)
+        install_handler(sig);
+    else if (sig && sig <= SIGCOUNT &&
+#ifdef SIGWINCH
+             sig != SIGWINCH &&
+#endif
+             sig != SIGCHLD)
+        signal_default(sig);
+    if (trapped & ZSIG_FUNC) {
+	char func[20];
+	HashNode hn;
+
+	sprintf(func, "TRAP%s", sigs[sig]);
+	if ((hn = shfunctab->removenode(shfunctab, func)))
+	    shfunctab->freenode(hn);
+    } else if (sigfuncs[sig]) {
+	freestruct(sigfuncs[sig]);
+	sigfuncs[sig] = NULL;
+    }
+}
+
+/* Execute a trap function for a given signal, possibly
+ * with non-standard sigtrapped & sigfuncs values
+ */
+
+/**/
+void
+dotrapargs(int sig, int *sigtr, void *sigfn)
+{
+    LinkList args;
+    char *name, num[4];
+    int trapret = 0;
+    int obreaks = breaks;
+ 
+    /* if signal is being ignored or the trap function		      *
+     * is NULL, then return					      *
+     *								      *
+     * Also return if errflag is set.  In fact, the code in the       *
+     * function will test for this, but this way we keep status flags *
+     * intact without working too hard.  Special cases (e.g. calling  *
+     * a trap for SIGINT after the error flag was set) are handled    *
+     * by the calling code.  (PWS 1995/06/08).			      */
+    if ((*sigtr & ZSIG_IGNORED) || !sigfn || errflag)
+        return;
+
+    *sigtr |= ZSIG_IGNORED;
+
+    lexsave();
+    execsave();
+    breaks = 0;
+    if (*sigtr & ZSIG_FUNC) {
+	PERMALLOC {
+	    args = newlinklist();
+	    name = (char *) zalloc(5 + strlen(sigs[sig]));
+	    sprintf(name, "TRAP%s", sigs[sig]);
+	    addlinknode(args, name);
+	    sprintf(num, "%d", sig);
+	    addlinknode(args, num);
+	} LASTALLOC;
+	trapreturn = -1;
+	doshfunc(sigfn, args, 0, 1);
+	freelinklist(args, (FreeFunc) NULL);
+	zsfree(name);
+    } else HEAPALLOC {
+	execlist(dupstruct(sigfn), 1, 0);
+    } LASTALLOC;
+    if (trapreturn > 0)
+	trapret = trapreturn;
+    else if (errflag)
+	trapret = 1;
+    execrestore();
+    lexrestore();
+
+    if (trapret > 0) {
+	breaks = loops;
+	errflag = 1;
+    } else {
+	breaks += obreaks;
+	if (breaks > loops)
+	    breaks = loops;
+    }
+
+    if (*sigtr != ZSIG_IGNORED)
+	*sigtr &= ~ZSIG_IGNORED;
+}
+
+/* Standard call to execute a trap for a given signal */
+
+/**/
+void
+dotrap(int sig)
+{
+    dotrapargs(sig, sigtrapped+sig, sigfuncs[sig]);
+}