Merge from vendor branch GDB:

[dragonfly.git] / usr.bin / make / job.c

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1988, 1989 by Adam de Boor
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#)job.c    8.2 (Berkeley) 3/19/94
 * $FreeBSD: src/usr.bin/make/job.c,v 1.17.2.2 2001/02/13 03:13:57 will Exp $
 * $DragonFly: src/usr.bin/make/job.c,v 1.14 2004/11/13 22:42:39 dillon Exp $
 */

#ifndef OLD_JOKE
#define OLD_JOKE 0
#endif /* OLD_JOKE */

/*-
 * job.c --
 *      handle the creation etc. of our child processes.
 *
 * Interface:
 *      Job_Make                Start the creation of the given target.
 *
 *      Job_CatchChildren       Check for and handle the termination of any
 *                              children. This must be called reasonably
 *                              frequently to keep the whole make going at
 *                              a decent clip, since job table entries aren't
 *                              removed until their process is caught this way.
 *                              Its single argument is TRUE if the function
 *                              should block waiting for a child to terminate.
 *
 *      Job_CatchOutput         Print any output our children have produced.
 *                              Should also be called fairly frequently to
 *                              keep the user informed of what's going on.
 *                              If no output is waiting, it will block for
 *                              a time given by the SEL_* constants, below,
 *                              or until output is ready.
 *
 *      Job_Init                Called to intialize this module. in addition,
 *                              any commands attached to the .BEGIN target
 *                              are executed before this function returns.
 *                              Hence, the makefile must have been parsed
 *                              before this function is called.
 *
 *      Job_Full                Return TRUE if the job table is filled.
 *
 *      Job_Empty               Return TRUE if the job table is completely
 *                              empty.
 *
 *      Job_ParseShell          Given the line following a .SHELL target, parse
 *                              the line as a shell specification. Returns
 *                              FAILURE if the spec was incorrect.
 *
 *      Job_Finish                      Perform any final processing which needs doing.
 *                              This includes the execution of any commands
 *                              which have been/were attached to the .END
 *                              target. It should only be called when the
 *                              job table is empty.
 *
 *      Job_AbortAll            Abort all currently running jobs. It doesn't
 *                              handle output or do anything for the jobs,
 *                              just kills them. It should only be called in
 *                              an emergency, as it were.
 *
 *      Job_CheckCommands       Verify that the commands for a target are
 *                              ok. Provide them if necessary and possible.
 *
 *      Job_Touch               Update a target without really updating it.
 *
 *      Job_Wait                Wait for all currently-running jobs to finish.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <errno.h>
#include <utime.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include "make.h"
#include "hash.h"
#include "dir.h"
#include "job.h"
#include "pathnames.h"
#ifdef REMOTE
#include "rmt.h"
# define STATIC
#else
# define STATIC static
#endif

/*
 * error handling variables
 */
static int      errors = 0;         /* number of errors reported */
static int      aborting = 0;       /* why is the make aborting? */
#define ABORT_ERROR     1           /* Because of an error */
#define ABORT_INTERRUPT 2           /* Because it was interrupted */
#define ABORT_WAIT      3           /* Waiting for jobs to finish */

/*
 * XXX: Avoid SunOS bug... FILENO() is fp->_file, and file
 * is a char! So when we go above 127 we turn negative!
 */
#define FILENO(a) ((unsigned) fileno(a))

/*
 * post-make command processing. The node postCommands is really just the
 * .END target but we keep it around to avoid having to search for it
 * all the time.
 */
static GNode      *postCommands;    /* node containing commands to execute when
                                     * everything else is done */
static int        numCommands;      /* The number of commands actually printed
                                     * for a target. Should this number be
                                     * 0, no shell will be executed. */

/*
 * Return values from JobStart.
 */
#define JOB_RUNNING     0       /* Job is running */
#define JOB_ERROR       1       /* Error in starting the job */
#define JOB_FINISHED    2       /* The job is already finished */
#define JOB_STOPPED     3       /* The job is stopped */

/*
 * tfile is used to build temp file names to store shell commands to
 * execute. 
 */
static char     tfile[sizeof(TMPPAT)];


/*
 * Descriptions for various shells.
 */
static Shell    shells[] = {
    /*
     * CSH description. The csh can do echo control by playing
     * with the setting of the 'echo' shell variable. Sadly,
     * however, it is unable to do error control nicely.
     */
{
    "csh",
    TRUE, "unset verbose", "set verbose", "unset verbose", 10,
    FALSE, "echo \"%s\"\n", "csh -c \"%s || exit 0\"",
    "v", "e",
},
    /*
     * SH description. Echo control is also possible and, under
     * sun UNIX anyway, one can even control error checking.
     */
{
    "sh",
    TRUE, "set -", "set -v", "set -", 5,
    TRUE, "set -e", "set +e",
#ifdef OLDBOURNESHELL
    FALSE, "echo \"%s\"\n", "sh -c '%s || exit 0'\n",
#endif
    "v", "e",
},
    /*
     * UNKNOWN.
     */
{
    (char *) 0,
    FALSE, (char *) 0, (char *) 0, (char *) 0, 0,
    FALSE, (char *) 0, (char *) 0,
    (char *) 0, (char *) 0,
}
};
static Shell    *commandShell = &shells[DEFSHELL];/* this is the shell to
                                                   * which we pass all
                                                   * commands in the Makefile.
                                                   * It is set by the
                                                   * Job_ParseShell function */
static char     *shellPath = NULL,                /* full pathname of
                                                   * executable image */
                *shellName;                       /* last component of shell */


static int      maxJobs;        /* The most children we can run at once */
static int      maxLocal;       /* The most local ones we can have */
STATIC int      nJobs;          /* The number of children currently running */
STATIC int      nLocal;         /* The number of local children */
STATIC Lst      jobs;           /* The structures that describe them */
STATIC Boolean  jobFull;        /* Flag to tell when the job table is full. It
                                 * is set TRUE when (1) the total number of
                                 * running jobs equals the maximum allowed or
                                 * (2) a job can only be run locally, but
                                 * nLocal equals maxLocal */
#ifndef RMT_WILL_WATCH
static fd_set   outputs;        /* Set of descriptors of pipes connected to
                                 * the output channels of children */
#endif

STATIC GNode    *lastNode;      /* The node for which output was most recently
                                 * produced. */
STATIC char     *targFmt;       /* Format string to use to head output from a
                                 * job when it's not the most-recent job heard
                                 * from */

#ifdef REMOTE
# define TARG_FMT  "--- %s at %s ---\n" /* Default format */
# define MESSAGE(fp, gn) \
        (void) fprintf(fp, targFmt, gn->name, gn->rem.hname);
#else
# define TARG_FMT  "--- %s ---\n" /* Default format */
# define MESSAGE(fp, gn) \
        (void) fprintf(fp, targFmt, gn->name);
#endif

/*
 * When JobStart attempts to run a job remotely but can't, and isn't allowed
 * to run the job locally, or when Job_CatchChildren detects a job that has
 * been migrated home, the job is placed on the stoppedJobs queue to be run
 * when the next job finishes.
 */
STATIC Lst      stoppedJobs;    /* Lst of Job structures describing
                                 * jobs that were stopped due to concurrency
                                 * limits or migration home */


#if defined(USE_PGRP) && defined(SYSV)
# define KILL(pid, sig)         killpg(-(pid), (sig))
#else
# if defined(USE_PGRP)
#  define KILL(pid, sig)        killpg((pid), (sig))
# else
#  define KILL(pid, sig)        kill((pid), (sig))
# endif
#endif

/*
 * Grmpf... There is no way to set bits of the wait structure
 * anymore with the stupid W*() macros. I liked the union wait
 * stuff much more. So, we devise our own macros... This is
 * really ugly, use dramamine sparingly. You have been warned.
 */
#define W_SETMASKED(st, val, fun)                               \
        {                                                       \
                int sh = (int) ~0;                              \
                int mask = fun(sh);                             \
                                                                \
                for (sh = 0; ((mask >> sh) & 1) == 0; sh++)     \
                        continue;                               \
                *(st) = (*(st) & ~mask) | ((val) << sh);        \
        }

#define W_SETTERMSIG(st, val) W_SETMASKED(st, val, WTERMSIG)
#define W_SETEXITSTATUS(st, val) W_SETMASKED(st, val, WEXITSTATUS)


static int JobCondPassSig(void *, void *);
static void JobPassSig(int);
static int JobCmpPid(void *, void *);
static int JobPrintCommand(void *, void *);
static int JobSaveCommand(void *, void *);
static void JobClose(Job *);
#ifdef REMOTE
static int JobCmpRmtID(Job *, int);
# ifdef RMT_WILL_WATCH
static void JobLocalInput(int, Job *);
# endif
#else
static void JobFinish(Job *, int *);
static void JobExec(Job *, char **);
#endif
static void JobMakeArgv(Job *, char **);
static void JobRestart(Job *);
static int JobStart(GNode *, int, Job *);
static char *JobOutput(Job *, char *, char *, int);
static void JobDoOutput(Job *, Boolean);
static Shell *JobMatchShell(char *);
static void JobInterrupt(int, int);
static void JobRestartJobs(void);

/*-
 *-----------------------------------------------------------------------
 * JobCondPassSig --
 *      Pass a signal to a job if the job is remote or if USE_PGRP
 *      is defined.
 *
 * Results:
 *      === 0
 *
 * Side Effects:
 *      None, except the job may bite it.
 *
 *-----------------------------------------------------------------------
 */
static int
JobCondPassSig(void *jobp, void *signop)
{
    Job *job = (Job *) jobp;
    int signo = *(int *) signop;
#ifdef RMT_WANTS_SIGNALS
    if (job->flags & JOB_REMOTE) {
        (void) Rmt_Signal(job, signo);
    } else {
        KILL(job->pid, signo);
    }
#else
    /*
     * Assume that sending the signal to job->pid will signal any remote
     * job as well.
     */
    DEBUGF(JOB, ("JobCondPassSig passing signal %d to child %d.\n", signo, job->pid));
    KILL(job->pid, signo);
#endif
    return 0;
}

/*-
 *-----------------------------------------------------------------------
 * JobPassSig --
 *      Pass a signal on to all remote jobs and to all local jobs if
 *      USE_PGRP is defined, then die ourselves.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      We die by the same signal.
 *
 *-----------------------------------------------------------------------
 */
static void
JobPassSig(int signo)
{
    sigset_t nmask, omask;
    struct sigaction act;

    DEBUGF(JOB, ("JobPassSig(%d) called.\n", signo));
    Lst_ForEach(jobs, JobCondPassSig, (void *) &signo);

    /*
     * Deal with proper cleanup based on the signal received. We only run
     * the .INTERRUPT target if the signal was in fact an interrupt. The other
     * three termination signals are more of a "get out *now*" command.
     */
    if (signo == SIGINT) {
        JobInterrupt(TRUE, signo);
    } else if ((signo == SIGHUP) || (signo == SIGTERM) || (signo == SIGQUIT)) {
        JobInterrupt(FALSE, signo);
    }

    /*
     * Leave gracefully if SIGQUIT, rather than core dumping.
     */
    if (signo == SIGQUIT) {
        signo = SIGINT;
    }

    /*
     * Send ourselves the signal now we've given the message to everyone else.
     * Note we block everything else possible while we're getting the signal.
     * This ensures that all our jobs get continued when we wake up before
     * we take any other signal.
     */
    sigemptyset(&nmask);
    sigaddset(&nmask, signo);
    sigprocmask(SIG_SETMASK, &nmask, &omask);
    act.sa_handler = SIG_DFL;
    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;
    sigaction(signo, &act, NULL);

    DEBUGF(JOB, ("JobPassSig passing signal to self, mask = %x.\n", ~0 & ~(1 << (signo-1))));
    (void) signal(signo, SIG_DFL);

    (void) KILL(getpid(), signo);

    signo = SIGCONT;
    Lst_ForEach(jobs, JobCondPassSig, (void *) &signo);

    (void) sigprocmask(SIG_SETMASK, &omask, NULL);
    sigprocmask(SIG_SETMASK, &omask, NULL);
    act.sa_handler = JobPassSig;
    sigaction(signo, &act, NULL);
}

/*-
 *-----------------------------------------------------------------------
 * JobCmpPid  --
 *      Compare the pid of the job with the given pid and return 0 if they
 *      are equal. This function is called from Job_CatchChildren via
 *      Lst_Find to find the job descriptor of the finished job.
 *
 * Results:
 *      0 if the pid's match
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static int
JobCmpPid(void *job, void *pid)
{
    return *(int *) pid - ((Job *) job)->pid;
}

#ifdef REMOTE
/*-
 *-----------------------------------------------------------------------
 * JobCmpRmtID  --
 *      Compare the rmtID of the job with the given rmtID and return 0 if they
 *      are equal.
 *
 * Results:
 *      0 if the rmtID's match
 *
 * Side Effects:
 *      None.
 *-----------------------------------------------------------------------
 */
static int
JobCmpRmtID(void *job, void *rmtID)
{
    return(*(int *) rmtID - *(int *) job->rmtID);
}
#endif

/*-
 *-----------------------------------------------------------------------
 * JobPrintCommand  --
 *      Put out another command for the given job. If the command starts
 *      with an @ or a - we process it specially. In the former case,
 *      so long as the -s and -n flags weren't given to make, we stick
 *      a shell-specific echoOff command in the script. In the latter,
 *      we ignore errors for the entire job, unless the shell has error
 *      control.
 *      If the command is just "..." we take all future commands for this
 *      job to be commands to be executed once the entire graph has been
 *      made and return non-zero to signal that the end of the commands
 *      was reached. These commands are later attached to the postCommands
 *      node and executed by Job_Finish when all things are done.
 *      This function is called from JobStart via Lst_ForEach.
 *
 * Results:
 *      Always 0, unless the command was "..."
 *
 * Side Effects:
 *      If the command begins with a '-' and the shell has no error control,
 *      the JOB_IGNERR flag is set in the job descriptor.
 *      If the command is "..." and we're not ignoring such things,
 *      tailCmds is set to the successor node of the cmd.
 *      numCommands is incremented if the command is actually printed.
 *-----------------------------------------------------------------------
 */
static int
JobPrintCommand(void *cmdp, void *jobp)
{
    Boolean       noSpecials;       /* true if we shouldn't worry about
                                     * inserting special commands into
                                     * the input stream. */
    Boolean       shutUp = FALSE;   /* true if we put a no echo command
                                     * into the command file */
    Boolean       errOff = FALSE;   /* true if we turned error checking
                                     * off before printing the command
                                     * and need to turn it back on */
    char          *cmdTemplate;     /* Template to use when printing the
                                     * command */
    char          *cmdStart;        /* Start of expanded command */
    LstNode       cmdNode;          /* Node for replacing the command */
    char          *cmd = (char *) cmdp;
    Job           *job = (Job *) jobp;

    noSpecials = (noExecute && !(job->node->type & OP_MAKE));

    if (strcmp(cmd, "...") == 0) {
        job->node->type |= OP_SAVE_CMDS;
        if ((job->flags & JOB_IGNDOTS) == 0) {
            job->tailCmds = Lst_Succ(Lst_Member(job->node->commands,
                                                (void *)cmd));
            return 1;
        }
        return 0;
    }

#define DBPRINTF(fmt, arg)                      \
   DEBUGF(JOB, (fmt, arg));                     \
   (void) fprintf(job->cmdFILE, fmt, arg);      \
   (void) fflush(job->cmdFILE);

    numCommands += 1;

    /*
     * For debugging, we replace each command with the result of expanding
     * the variables in the command.
     */
    cmdNode = Lst_Member(job->node->commands, (void *)cmd);
    cmdStart = cmd = Var_Subst(NULL, cmd, job->node, FALSE);
    Lst_Replace(cmdNode, (void *)cmdStart);

    cmdTemplate = "%s\n";

    /*
     * Check for leading @' and -'s to control echoing and error checking.
     */
    while (*cmd == '@' || *cmd == '-') {
        if (*cmd == '@') {
            shutUp = DEBUG(LOUD) ? FALSE : TRUE;
        } else {
            errOff = TRUE;
        }
        cmd++;
    }

    while (isspace((unsigned char) *cmd))
        cmd++;

    if (shutUp) {
        if (!(job->flags & JOB_SILENT) && !noSpecials &&
            commandShell->hasEchoCtl) {
                DBPRINTF("%s\n", commandShell->echoOff);
        } else {
            shutUp = FALSE;
        }
    }

    if (errOff) {
        if ( !(job->flags & JOB_IGNERR) && !noSpecials) {
            if (commandShell->hasErrCtl) {
                /*
                 * we don't want the error-control commands showing
                 * up either, so we turn off echoing while executing
                 * them. We could put another field in the shell
                 * structure to tell JobDoOutput to look for this
                 * string too, but why make it any more complex than
                 * it already is?
                 */
                if (!(job->flags & JOB_SILENT) && !shutUp &&
                    commandShell->hasEchoCtl) {
                        DBPRINTF("%s\n", commandShell->echoOff);
                        DBPRINTF("%s\n", commandShell->ignErr);
                        DBPRINTF("%s\n", commandShell->echoOn);
                } else {
                    DBPRINTF("%s\n", commandShell->ignErr);
                }
            } else if (commandShell->ignErr &&
                      (*commandShell->ignErr != '\0'))
            {
                /*
                 * The shell has no error control, so we need to be
                 * weird to get it to ignore any errors from the command.
                 * If echoing is turned on, we turn it off and use the
                 * errCheck template to echo the command. Leave echoing
                 * off so the user doesn't see the weirdness we go through
                 * to ignore errors. Set cmdTemplate to use the weirdness
                 * instead of the simple "%s\n" template.
                 */
                if (!(job->flags & JOB_SILENT) && !shutUp &&
                    commandShell->hasEchoCtl) {
                        DBPRINTF("%s\n", commandShell->echoOff);
                        DBPRINTF(commandShell->errCheck, cmd);
                        shutUp = TRUE;
                }
                cmdTemplate = commandShell->ignErr;
                /*
                 * The error ignoration (hee hee) is already taken care
                 * of by the ignErr template, so pretend error checking
                 * is still on.
                 */
                errOff = FALSE;
            } else {
                errOff = FALSE;
            }
        } else {
            errOff = FALSE;
        }
    }

    DBPRINTF(cmdTemplate, cmd);

    if (errOff) {
        /*
         * If echoing is already off, there's no point in issuing the
         * echoOff command. Otherwise we issue it and pretend it was on
         * for the whole command...
         */
        if (!shutUp && !(job->flags & JOB_SILENT) && commandShell->hasEchoCtl){
            DBPRINTF("%s\n", commandShell->echoOff);
            shutUp = TRUE;
        }
        DBPRINTF("%s\n", commandShell->errCheck);
    }
    if (shutUp) {
        DBPRINTF("%s\n", commandShell->echoOn);
    }
    return 0;
}

/*-
 *-----------------------------------------------------------------------
 * JobSaveCommand --
 *      Save a command to be executed when everything else is done.
 *      Callback function for JobFinish...
 *
 * Results:
 *      Always returns 0
 *
 * Side Effects:
 *      The command is tacked onto the end of postCommands's commands list.
 *
 *-----------------------------------------------------------------------
 */
static int
JobSaveCommand(void *cmd, void *gn)
{
    cmd = (void *) Var_Subst(NULL, (char *) cmd, (GNode *) gn, FALSE);
    (void) Lst_AtEnd(postCommands->commands, cmd);
    return(0);
}


/*-
 *-----------------------------------------------------------------------
 * JobClose --
 *      Called to close both input and output pipes when a job is finished.
 *
 * Results:
 *      Nada
 *
 * Side Effects:
 *      The file descriptors associated with the job are closed.
 *
 *-----------------------------------------------------------------------
 */
static void
JobClose(Job *job)
{
    if (usePipes) {
#ifdef RMT_WILL_WATCH
        Rmt_Ignore(job->inPipe);
#else
        FD_CLR(job->inPipe, &outputs);
#endif
        if (job->outPipe != job->inPipe) {
           (void) close(job->outPipe);
        }
        JobDoOutput(job, TRUE);
        (void) close(job->inPipe);
    } else {
        (void) close(job->outFd);
        JobDoOutput(job, TRUE);
    }
}

/*-
 *-----------------------------------------------------------------------
 * JobFinish  --
 *      Do final processing for the given job including updating
 *      parents and starting new jobs as available/necessary. Note
 *      that we pay no attention to the JOB_IGNERR flag here.
 *      This is because when we're called because of a noexecute flag
 *      or something, jstat.w_status is 0 and when called from
 *      Job_CatchChildren, the status is zeroed if it s/b ignored.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Some nodes may be put on the toBeMade queue.
 *      Final commands for the job are placed on postCommands.
 *
 *      If we got an error and are aborting (aborting == ABORT_ERROR) and
 *      the job list is now empty, we are done for the day.
 *      If we recognized an error (errors !=0), we set the aborting flag
 *      to ABORT_ERROR so no more jobs will be started.
 *-----------------------------------------------------------------------
 */
/*ARGSUSED*/
static void
JobFinish(Job *job, int *status)
{
    Boolean      done;

    if ((WIFEXITED(*status) &&
         (((WEXITSTATUS(*status) != 0) && !(job->flags & JOB_IGNERR)))) ||
        (WIFSIGNALED(*status) && (WTERMSIG(*status) != SIGCONT)))
    {
        /*
         * If it exited non-zero and either we're doing things our
         * way or we're not ignoring errors, the job is finished.
         * Similarly, if the shell died because of a signal
         * the job is also finished. In these
         * cases, finish out the job's output before printing the exit
         * status...
         */
#ifdef REMOTE
        KILL(job->pid, SIGCONT);
#endif
        JobClose(job);
        if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
           (void) fclose(job->cmdFILE);
        }
        done = TRUE;
#ifdef REMOTE
        if (job->flags & JOB_REMOTE)
            Rmt_Done(job->rmtID, job->node);
#endif
    } else if (WIFEXITED(*status)) {
        /*
         * Deal with ignored errors in -B mode. We need to print a message
         * telling of the ignored error as well as setting status.w_status
         * to 0 so the next command gets run. To do this, we set done to be
         * TRUE if in -B mode and the job exited non-zero.
         */
        done = WEXITSTATUS(*status) != 0;
        /*
         * Old comment said: "Note we don't
         * want to close down any of the streams until we know we're at the
         * end."
         * But we do. Otherwise when are we going to print the rest of the
         * stuff?
         */
        JobClose(job);
#ifdef REMOTE
        if (job->flags & JOB_REMOTE)
            Rmt_Done(job->rmtID, job->node);
#endif /* REMOTE */
    } else {
        /*
         * No need to close things down or anything.
         */
        done = FALSE;
    }

    if (done ||
        WIFSTOPPED(*status) ||
        (WIFSIGNALED(*status) && (WTERMSIG(*status) == SIGCONT)) ||
        DEBUG(JOB))
    {
        FILE      *out;

        if (compatMake && !usePipes && (job->flags & JOB_IGNERR)) {
            /*
             * If output is going to a file and this job is ignoring
             * errors, arrange to have the exit status sent to the
             * output file as well.
             */
            out = fdopen(job->outFd, "w");
            if (out == NULL)
                Punt("Cannot fdopen");
        } else {
            out = stdout;
        }

        if (WIFEXITED(*status)) {
            DEBUGF(JOB, ("Process %d exited.\n", job->pid));
            if (WEXITSTATUS(*status) != 0) {
                if (usePipes && job->node != lastNode) {
                    MESSAGE(out, job->node);
                    lastNode = job->node;
                }
                (void) fprintf(out, "*** Error code %d%s\n",
                               WEXITSTATUS(*status),
                               (job->flags & JOB_IGNERR) ? "(ignored)" : "");

                if (job->flags & JOB_IGNERR) {
                    *status = 0;
                }
            } else if (DEBUG(JOB)) {
                if (usePipes && job->node != lastNode) {
                    MESSAGE(out, job->node);
                    lastNode = job->node;
                }
                (void) fprintf(out, "*** Completed successfully\n");
            }
        } else if (WIFSTOPPED(*status)) {
            DEBUGF(JOB, ("Process %d stopped.\n", job->pid));
            if (usePipes && job->node != lastNode) {
                MESSAGE(out, job->node);
                lastNode = job->node;
            }
            if (!(job->flags & JOB_REMIGRATE)) {
                (void) fprintf(out, "*** Stopped -- signal %d\n",
                    WSTOPSIG(*status));
            }
            job->flags |= JOB_RESUME;
            (void)Lst_AtEnd(stoppedJobs, (void *)job);
#ifdef REMOTE
            if (job->flags & JOB_REMIGRATE)
                JobRestart(job);
#endif
            (void) fflush(out);
            return;
        } else if (WTERMSIG(*status) == SIGCONT) {
            /*
             * If the beastie has continued, shift the Job from the stopped
             * list to the running one (or re-stop it if concurrency is
             * exceeded) and go and get another child.
             */
            if (job->flags & (JOB_RESUME|JOB_REMIGRATE|JOB_RESTART)) {
                if (usePipes && job->node != lastNode) {
                    MESSAGE(out, job->node);
                    lastNode = job->node;
                }
                (void) fprintf(out, "*** Continued\n");
            }
            if (!(job->flags & JOB_CONTINUING)) {
                DEBUGF(JOB, ("Warning: process %d was not continuing.\n", job->pid));
#ifdef notdef
                /*
                 * We don't really want to restart a job from scratch just
                 * because it continued, especially not without killing the
                 * continuing process!  That's why this is ifdef'ed out.
                 * FD - 9/17/90
                 */
                JobRestart(job);
#endif
            }
            job->flags &= ~JOB_CONTINUING;
            Lst_AtEnd(jobs, (void *)job);
            nJobs += 1;
            if (!(job->flags & JOB_REMOTE)) {
                DEBUGF(JOB, ("Process %d is continuing locally.\n", job->pid));
                nLocal += 1;
            }
            if (nJobs == maxJobs) {
                jobFull = TRUE;
                DEBUGF(JOB, ("Job queue is full.\n"));
            }
            (void) fflush(out);
            return;
        } else {
            if (usePipes && job->node != lastNode) {
                MESSAGE(out, job->node);
                lastNode = job->node;
            }
            (void) fprintf(out, "*** Signal %d\n", WTERMSIG(*status));
        }

        (void) fflush(out);
    }

    /*
     * Now handle the -B-mode stuff. If the beast still isn't finished,
     * try and restart the job on the next command. If JobStart says it's
     * ok, it's ok. If there's an error, this puppy is done.
     */
    if (compatMake && (WIFEXITED(*status) &&
        !Lst_IsAtEnd(job->node->commands))) {
        switch (JobStart(job->node, job->flags & JOB_IGNDOTS, job)) {
        case JOB_RUNNING:
            done = FALSE;
            break;
        case JOB_ERROR:
            done = TRUE;
            W_SETEXITSTATUS(status, 1);
            break;
        case JOB_FINISHED:
            /*
             * If we got back a JOB_FINISHED code, JobStart has already
             * called Make_Update and freed the job descriptor. We set
             * done to false here to avoid fake cycles and double frees.
             * JobStart needs to do the update so we can proceed up the
             * graph when given the -n flag..
             */
            done = FALSE;
            break;
        }
    } else {
        done = TRUE;
    }


    if (done &&
        (aborting != ABORT_ERROR) &&
        (aborting != ABORT_INTERRUPT) &&
        (*status == 0))
    {
        /*
         * As long as we aren't aborting and the job didn't return a non-zero
         * status that we shouldn't ignore, we call Make_Update to update
         * the parents. In addition, any saved commands for the node are placed
         * on the .END target.
         */
        if (job->tailCmds != NULL) {
            Lst_ForEachFrom(job->node->commands, job->tailCmds,
                             JobSaveCommand,
                            (void *)job->node);
        }
        job->node->made = MADE;
        Make_Update(job->node);
        free(job);
    } else if (*status != 0) {
        errors += 1;
        free(job);
    }

    JobRestartJobs();

    /*
     * Set aborting if any error.
     */
    if (errors && !keepgoing && (aborting != ABORT_INTERRUPT)) {
        /*
         * If we found any errors in this batch of children and the -k flag
         * wasn't given, we set the aborting flag so no more jobs get
         * started.
         */
        aborting = ABORT_ERROR;
    }

    if ((aborting == ABORT_ERROR) && Job_Empty())
        /*
         * If we are aborting and the job table is now empty, we finish.
         */
        Finish(errors);
}

/*-
 *-----------------------------------------------------------------------
 * Job_Touch --
 *      Touch the given target. Called by JobStart when the -t flag was
 *      given.  Prints messages unless told to be silent.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      The data modification of the file is changed. In addition, if the
 *      file did not exist, it is created.
 *-----------------------------------------------------------------------
 */
void
Job_Touch(GNode *gn, Boolean silent)
{
    int           streamID;     /* ID of stream opened to do the touch */
    struct utimbuf times;       /* Times for utime() call */

    if (gn->type & (OP_JOIN|OP_USE|OP_EXEC|OP_OPTIONAL)) {
        /*
         * .JOIN, .USE, .ZEROTIME and .OPTIONAL targets are "virtual" targets
         * and, as such, shouldn't really be created.
         */
        return;
    }

    if (!silent) {
        (void) fprintf(stdout, "touch %s\n", gn->name);
        (void) fflush(stdout);
    }

    if (noExecute) {
        return;
    }

    if (gn->type & OP_ARCHV) {
        Arch_Touch(gn);
    } else if (gn->type & OP_LIB) {
        Arch_TouchLib(gn);
    } else {
        char    *file = gn->path ? gn->path : gn->name;

        times.actime = times.modtime = now;
        if (utime(file, &times) < 0){
            streamID = open(file, O_RDWR | O_CREAT, 0666);

            if (streamID >= 0) {
                char    c;

                /*
                 * Read and write a byte to the file to change the
                 * modification time, then close the file.
                 */
                if (read(streamID, &c, 1) == 1) {
                    (void) lseek(streamID, 0L, SEEK_SET);
                    (void) write(streamID, &c, 1);
                }

                (void) close(streamID);
            } else {
                (void) fprintf(stdout, "*** couldn't touch %s: %s",
                               file, strerror(errno));
                (void) fflush(stdout);
            }
        }
    }
}

/*-
 *-----------------------------------------------------------------------
 * Job_CheckCommands --
 *      Make sure the given node has all the commands it needs.
 *
 * Results:
 *      TRUE if the commands list is/was ok.
 *
 * Side Effects:
 *      The node will have commands from the .DEFAULT rule added to it
 *      if it needs them.
 *-----------------------------------------------------------------------
 */
Boolean
Job_CheckCommands(GNode *gn, void (*abortProc)(const char *, ...))
{
    if (OP_NOP(gn->type) && Lst_IsEmpty(gn->commands) &&
        (gn->type & OP_LIB) == 0) {
        /*
         * No commands. Look for .DEFAULT rule from which we might infer
         * commands
         */
        if ((DEFAULT != NULL) && !Lst_IsEmpty(DEFAULT->commands)) {
            char *p1;
            /*
             * Make only looks for a .DEFAULT if the node was never the
             * target of an operator, so that's what we do too. If
             * a .DEFAULT was given, we substitute its commands for gn's
             * commands and set the IMPSRC variable to be the target's name
             * The DEFAULT node acts like a transformation rule, in that
             * gn also inherits any attributes or sources attached to
             * .DEFAULT itself.
             */
            Make_HandleUse(DEFAULT, gn);
            Var_Set(IMPSRC, Var_Value(TARGET, gn, &p1), gn);
            free(p1);
        } else if (Dir_MTime(gn) == 0) {
            /*
             * The node wasn't the target of an operator we have no .DEFAULT
             * rule to go on and the target doesn't already exist. There's
             * nothing more we can do for this branch. If the -k flag wasn't
             * given, we stop in our tracks, otherwise we just don't update
             * this node's parents so they never get examined.
             */
            static const char msg[] = "make: don't know how to make";

            if (gn->type & OP_OPTIONAL) {
                (void) fprintf(stdout, "%s %s(ignored)\n", msg, gn->name);
                (void) fflush(stdout);
            } else if (keepgoing) {
                (void) fprintf(stdout, "%s %s(continuing)\n", msg, gn->name);
                (void) fflush(stdout);
                return FALSE;
            } else {
#if OLD_JOKE
                if (strcmp(gn->name,"love") == 0)
                    (*abortProc)("Not war.");
                else
#endif
                    (*abortProc)("%s %s. Stop", msg, gn->name);
                return FALSE;
            }
        }
    }
    return TRUE;
}
#ifdef RMT_WILL_WATCH
/*-
 *-----------------------------------------------------------------------
 * JobLocalInput --
 *      Handle a pipe becoming readable. Callback function for Rmt_Watch
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      JobDoOutput is called.
 *
 *-----------------------------------------------------------------------
 */
/*ARGSUSED*/
static void
JobLocalInput(int stream, Job *job)
{
    JobDoOutput(job, FALSE);
}
#endif /* RMT_WILL_WATCH */

/*-
 *-----------------------------------------------------------------------
 * JobExec --
 *      Execute the shell for the given job. Called from JobStart and
 *      JobRestart.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      A shell is executed, outputs is altered and the Job structure added
 *      to the job table.
 *
 *-----------------------------------------------------------------------
 */
static void
JobExec(Job *job, char **argv)
{
    int           cpid;         /* ID of new child */

    if (DEBUG(JOB)) {
        int       i;

        DEBUGF(JOB, ("Running %s %sly\n", job->node->name,
               job->flags&JOB_REMOTE?"remote":"local"));
        DEBUGF(JOB, ("\tCommand: "));
        for (i = 0; argv[i] != NULL; i++) {
            DEBUGF(JOB, ("%s ", argv[i]));
        }
        DEBUGF(JOB, ("\n"));
    }

    /*
     * Some jobs produce no output and it's disconcerting to have
     * no feedback of their running (since they produce no output, the
     * banner with their name in it never appears). This is an attempt to
     * provide that feedback, even if nothing follows it.
     */
    if ((lastNode != job->node) && (job->flags & JOB_FIRST) &&
        !(job->flags & JOB_SILENT)) {
        MESSAGE(stdout, job->node);
        lastNode = job->node;
    }

#ifdef RMT_NO_EXEC
    if (job->flags & JOB_REMOTE) {
        goto jobExecFinish;
    }
#endif /* RMT_NO_EXEC */

    if ((cpid = vfork()) == -1) {
        Punt("Cannot fork");
    } else if (cpid == 0) {

        /*
         * Must duplicate the input stream down to the child's input and
         * reset it to the beginning (again). Since the stream was marked
         * close-on-exec, we must clear that bit in the new input.
         */
        if (dup2(FILENO(job->cmdFILE), 0) == -1)
            Punt("Cannot dup2: %s", strerror(errno));
        (void) fcntl(0, F_SETFD, 0);
        (void) lseek(0, 0, SEEK_SET);

        if (usePipes) {
            /*
             * Set up the child's output to be routed through the pipe
             * we've created for it.
             */
            if (dup2(job->outPipe, 1) == -1)
                Punt("Cannot dup2: %s", strerror(errno));
        } else {
            /*
             * We're capturing output in a file, so we duplicate the
             * descriptor to the temporary file into the standard
             * output.
             */
            if (dup2(job->outFd, 1) == -1)
                Punt("Cannot dup2: %s", strerror(errno));
        }
        /*
         * The output channels are marked close on exec. This bit was
         * duplicated by the dup2 (on some systems), so we have to clear
         * it before routing the shell's error output to the same place as
         * its standard output.
         */
        (void) fcntl(1, F_SETFD, 0);
        if (dup2(1, 2) == -1)
            Punt("Cannot dup2: %s", strerror(errno));

#ifdef USE_PGRP
        /*
         * We want to switch the child into a different process family so
         * we can kill it and all its descendants in one fell swoop,
         * by killing its process family, but not commit suicide.
         */
# if defined(SYSV)
        (void) setsid();
# else
        (void) setpgid(0, getpid());
# endif
#endif /* USE_PGRP */

#ifdef REMOTE
        if (job->flags & JOB_REMOTE) {
            Rmt_Exec(shellPath, argv, FALSE);
        } else
#endif /* REMOTE */
           (void) execv(shellPath, argv);

        (void) write(2, "Could not execute shell\n",
                     sizeof("Could not execute shell"));
        _exit(1);
    } else {
#ifdef REMOTE
        long omask = sigblock(sigmask(SIGCHLD));
#endif
        job->pid = cpid;

        if (usePipes && (job->flags & JOB_FIRST) ) {
            /*
             * The first time a job is run for a node, we set the current
             * position in the buffer to the beginning and mark another
             * stream to watch in the outputs mask
             */
            job->curPos = 0;

#ifdef RMT_WILL_WATCH
            Rmt_Watch(job->inPipe, JobLocalInput, job);
#else
            FD_SET(job->inPipe, &outputs);
#endif /* RMT_WILL_WATCH */
        }

        if (job->flags & JOB_REMOTE) {
#ifndef REMOTE
            job->rmtID = 0;
#else
            job->rmtID = Rmt_LastID(job->pid);
#endif /* REMOTE */
        } else {
            nLocal += 1;
            /*
             * XXX: Used to not happen if REMOTE. Why?
             */
            if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
                (void) fclose(job->cmdFILE);
                job->cmdFILE = NULL;
            }
        }
#ifdef REMOTE
        (void) sigsetmask(omask);
#endif
    }

#ifdef RMT_NO_EXEC
jobExecFinish:
#endif
    /*
     * Now the job is actually running, add it to the table.
     */
    nJobs += 1;
    (void) Lst_AtEnd(jobs, (void *)job);
    if (nJobs == maxJobs) {
        jobFull = TRUE;
    }
}

/*-
 *-----------------------------------------------------------------------
 * JobMakeArgv --
 *      Create the argv needed to execute the shell for a given job.
 *
 *
 * Results:
 *
 * Side Effects:
 *
 *-----------------------------------------------------------------------
 */
static void
JobMakeArgv(Job *job, char **argv)
{
    int           argc;
    static char   args[10];     /* For merged arguments */

    argv[0] = shellName;
    argc = 1;

    if ((commandShell->exit && (*commandShell->exit != '-')) ||
        (commandShell->echo && (*commandShell->echo != '-')))
    {
        /*
         * At least one of the flags doesn't have a minus before it, so
         * merge them together. Have to do this because the *(&(@*#*&#$#
         * Bourne shell thinks its second argument is a file to source.
         * Grrrr. Note the ten-character limitation on the combined arguments.
         */
        (void)sprintf(args, "-%s%s",
                      ((job->flags & JOB_IGNERR) ? "" :
                       (commandShell->exit ? commandShell->exit : "")),
                      ((job->flags & JOB_SILENT) ? "" :
                       (commandShell->echo ? commandShell->echo : "")));

        if (args[1]) {
            argv[argc] = args;
            argc++;
        }
    } else {
        if (!(job->flags & JOB_IGNERR) && commandShell->exit) {
            argv[argc] = commandShell->exit;
            argc++;
        }
        if (!(job->flags & JOB_SILENT) && commandShell->echo) {
            argv[argc] = commandShell->echo;
            argc++;
        }
    }
    argv[argc] = NULL;
}

/*-
 *-----------------------------------------------------------------------
 * JobRestart --
 *      Restart a job that stopped for some reason.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      jobFull will be set if the job couldn't be run.
 *
 *-----------------------------------------------------------------------
 */
static void
JobRestart(Job *job)
{
#ifdef REMOTE
    int host;
#endif

    if (job->flags & JOB_REMIGRATE) {
        if (
#ifdef REMOTE
            verboseRemigrates ||
#endif
            DEBUG(JOB)) {
           (void) fprintf(stdout, "*** remigrating %x(%s)\n",
                           job->pid, job->node->name);
           (void) fflush(stdout);
        }

#ifdef REMOTE
        if (!Rmt_ReExport(job->pid, job->node, &host)) {
            if (verboseRemigrates || DEBUG(JOB)) {
                (void) fprintf(stdout, "*** couldn't migrate...\n");
                (void) fflush(stdout);
            }
#endif
            if (nLocal != maxLocal) {
                /*
                 * Job cannot be remigrated, but there's room on the local
                 * machine, so resume the job and note that another
                 * local job has started.
                 */
                if (
#ifdef REMOTE
                    verboseRemigrates ||
#endif
                    DEBUG(JOB)) {
                    (void) fprintf(stdout, "*** resuming on local machine\n");
                    (void) fflush(stdout);
                }
                KILL(job->pid, SIGCONT);
                nLocal +=1;
#ifdef REMOTE
                job->flags &= ~(JOB_REMIGRATE|JOB_RESUME|JOB_REMOTE);
                job->flags |= JOB_CONTINUING;
#else
                job->flags &= ~(JOB_REMIGRATE|JOB_RESUME);
#endif
        } else {
                /*
                 * Job cannot be restarted. Mark the table as full and
                 * place the job back on the list of stopped jobs.
                 */
                if (
#ifdef REMOTE
                    verboseRemigrates ||
#endif
                    DEBUG(JOB)) {
                   (void) fprintf(stdout, "*** holding\n");
                   (void) fflush(stdout);
                }
                (void)Lst_AtFront(stoppedJobs, (void *)job);
                jobFull = TRUE;
                DEBUGF(JOB, ("Job queue is full.\n"));
                return;
            }
#ifdef REMOTE
        } else {
            /*
             * Clear out the remigrate and resume flags. Set the continuing
             * flag so we know later on that the process isn't exiting just
             * because of a signal.
             */
            job->flags &= ~(JOB_REMIGRATE|JOB_RESUME);
            job->flags |= JOB_CONTINUING;
            job->rmtID = host;
        }
#endif

        (void)Lst_AtEnd(jobs, (void *)job);
        nJobs += 1;
        if (nJobs == maxJobs) {
            jobFull = TRUE;
            DEBUGF(JOB, ("Job queue is full.\n"));
        }
    } else if (job->flags & JOB_RESTART) {
        /*
         * Set up the control arguments to the shell. This is based on the
         * flags set earlier for this job. If the JOB_IGNERR flag is clear,
         * the 'exit' flag of the commandShell is used to cause it to exit
         * upon receiving an error. If the JOB_SILENT flag is clear, the
         * 'echo' flag of the commandShell is used to get it to start echoing
         * as soon as it starts processing commands.
         */
        char      *argv[4];

        JobMakeArgv(job, argv);

        DEBUGF(JOB, ("Restarting %s...", job->node->name));
#ifdef REMOTE
        if ((job->node->type&OP_NOEXPORT) ||
            (nLocal < maxLocal && runLocalFirst)
# ifdef RMT_NO_EXEC
            || !Rmt_Export(shellPath, argv, job)
# else
            || !Rmt_Begin(shellPath, argv, job->node)
# endif
#endif
        {
            if (((nLocal >= maxLocal) && !(job->flags & JOB_SPECIAL))) {
                /*
                 * Can't be exported and not allowed to run locally -- put it
                 * back on the hold queue and mark the table full
                 */
                DEBUGF(JOB, ("holding\n"));
                (void)Lst_AtFront(stoppedJobs, (void *)job);
                jobFull = TRUE;
                DEBUGF(JOB, ("Job queue is full.\n"));
                return;
            } else {
                /*
                 * Job may be run locally.
                 */
                DEBUGF(JOB, ("running locally\n"));
                job->flags &= ~JOB_REMOTE;
            }
        }
#ifdef REMOTE
        else {
            /*
             * Can be exported. Hooray!
             */
            DEBUGF(JOB, ("exporting\n"));
            job->flags |= JOB_REMOTE;
        }
#endif
        JobExec(job, argv);
    } else {
        /*
         * The job has stopped and needs to be restarted. Why it stopped,
         * we don't know...
         */
        DEBUGF(JOB, ("Resuming %s...", job->node->name));
        if (((job->flags & JOB_REMOTE) ||
            (nLocal < maxLocal) ||
#ifdef REMOTE
            (((job->flags & JOB_SPECIAL) &&
              (job->node->type & OP_NOEXPORT)) &&
             (maxLocal == 0))) &&
#else
            ((job->flags & JOB_SPECIAL) &&
             (maxLocal == 0))) &&
#endif
           (nJobs != maxJobs))
        {
            /*
             * If the job is remote, it's ok to resume it as long as the
             * maximum concurrency won't be exceeded. If it's local and
             * we haven't reached the local concurrency limit already (or the
             * job must be run locally and maxLocal is 0), it's also ok to
             * resume it.
             */
            Boolean error;
            int status;

#ifdef RMT_WANTS_SIGNALS
            if (job->flags & JOB_REMOTE) {
                error = !Rmt_Signal(job, SIGCONT);
            } else
#endif  /* RMT_WANTS_SIGNALS */
                error = (KILL(job->pid, SIGCONT) != 0);

            if (!error) {
                /*
                 * Make sure the user knows we've continued the beast and
                 * actually put the thing in the job table.
                 */
                job->flags |= JOB_CONTINUING;
                W_SETTERMSIG(&status, SIGCONT);
                JobFinish(job, &status);

                job->flags &= ~(JOB_RESUME|JOB_CONTINUING);
                DEBUGF(JOB, ("done\n"));
            } else {
                Error("couldn't resume %s: %s",
                    job->node->name, strerror(errno));
                status = 0;
                W_SETEXITSTATUS(&status, 1);
                JobFinish(job, &status);
            }
        } else {
            /*
             * Job cannot be restarted. Mark the table as full and
             * place the job back on the list of stopped jobs.
             */
            DEBUGF(JOB, ("table full\n"));
            (void) Lst_AtFront(stoppedJobs, (void *)job);
            jobFull = TRUE;
            DEBUGF(JOB, ("Job queue is full.\n"));
        }
    }
}

/*-
 *-----------------------------------------------------------------------
 * JobStart  --
 *      Start a target-creation process going for the target described
 *      by the graph node gn.
 *
 * Results:
 *      JOB_ERROR if there was an error in the commands, JOB_FINISHED
 *      if there isn't actually anything left to do for the job and
 *      JOB_RUNNING if the job has been started.
 *
 * Side Effects:
 *      A new Job node is created and added to the list of running
 *      jobs. PMake is forked and a child shell created.
 *-----------------------------------------------------------------------
 */
static int
JobStart(GNode *gn, int flags, Job *previous)
{
    Job           *job;       /* new job descriptor */
    char          *argv[4];   /* Argument vector to shell */
    Boolean       cmdsOK;     /* true if the nodes commands were all right */
    Boolean       local;      /* Set true if the job was run locally */
    Boolean       noExec;     /* Set true if we decide not to run the job */
    int           tfd;        /* File descriptor for temp file */

    if (previous != NULL) {
        previous->flags &= ~(JOB_FIRST|JOB_IGNERR|JOB_SILENT|JOB_REMOTE);
        job = previous;
    } else {
        job = (Job *) emalloc(sizeof(Job));
        if (job == NULL) {
            Punt("JobStart out of memory");
        }
        flags |= JOB_FIRST;
    }

    job->node = gn;
    job->tailCmds = NULL;

    /*
     * Set the initial value of the flags for this job based on the global
     * ones and the node's attributes... Any flags supplied by the caller
     * are also added to the field.
     */
    job->flags = 0;
    if (Targ_Ignore(gn)) {
        job->flags |= JOB_IGNERR;
    }
    if (Targ_Silent(gn)) {
        job->flags |= JOB_SILENT;
    }
    job->flags |= flags;

    /*
     * Check the commands now so any attributes from .DEFAULT have a chance
     * to migrate to the node
     */
    if (!compatMake && job->flags & JOB_FIRST) {
        cmdsOK = Job_CheckCommands(gn, Error);
    } else {
        cmdsOK = TRUE;
    }

    /*
     * If the -n flag wasn't given, we open up OUR (not the child's)
     * temporary file to stuff commands in it. The thing is rd/wr so we don't
     * need to reopen it to feed it to the shell. If the -n flag *was* given,
     * we just set the file to be stdout. Cute, huh?
     */
    if ((gn->type & OP_MAKE) || (!noExecute && !touchFlag)) {
        /*
         * We're serious here, but if the commands were bogus, we're
         * also dead...
         */
        if (!cmdsOK) {
            DieHorribly();
        }

        (void) strcpy(tfile, TMPPAT);
        if ((tfd = mkstemp(tfile)) == -1)
            Punt("Cannot create temp file: %s", strerror(errno));
        job->cmdFILE = fdopen(tfd, "w+");
        eunlink(tfile);
        if (job->cmdFILE == NULL) {
            close(tfd);
            Punt("Could not open %s", tfile);
        }
        (void) fcntl(FILENO(job->cmdFILE), F_SETFD, 1);
        /*
         * Send the commands to the command file, flush all its buffers then
         * rewind and remove the thing.
         */
        noExec = FALSE;

        /*
         * used to be backwards; replace when start doing multiple commands
         * per shell.
         */
        if (compatMake) {
            /*
             * Be compatible: If this is the first time for this node,
             * verify its commands are ok and open the commands list for
             * sequential access by later invocations of JobStart.
             * Once that is done, we take the next command off the list
             * and print it to the command file. If the command was an
             * ellipsis, note that there's nothing more to execute.
             */
            if ((job->flags&JOB_FIRST) && (Lst_Open(gn->commands) != SUCCESS)){
                cmdsOK = FALSE;
            } else {
                LstNode ln = Lst_Next(gn->commands);

                if ((ln == NULL) ||
                    JobPrintCommand((void *) Lst_Datum(ln),
                                    (void *) job))
                {
                    noExec = TRUE;
                    Lst_Close(gn->commands);
                }
                if (noExec && !(job->flags & JOB_FIRST)) {
                    /*
                     * If we're not going to execute anything, the job
                     * is done and we need to close down the various
                     * file descriptors we've opened for output, then
                     * call JobDoOutput to catch the final characters or
                     * send the file to the screen... Note that the i/o streams
                     * are only open if this isn't the first job.
                     * Note also that this could not be done in
                     * Job_CatchChildren b/c it wasn't clear if there were
                     * more commands to execute or not...
                     */
                    JobClose(job);
                }
            }
        } else {
            /*
             * We can do all the commands at once. hooray for sanity
             */
            numCommands = 0;
            Lst_ForEach(gn->commands, JobPrintCommand, (void *)job);

            /*
             * If we didn't print out any commands to the shell script,
             * there's not much point in executing the shell, is there?
             */
            if (numCommands == 0) {
                noExec = TRUE;
            }
        }
    } else if (noExecute) {
        /*
         * Not executing anything -- just print all the commands to stdout
         * in one fell swoop. This will still set up job->tailCmds correctly.
         */
        if (lastNode != gn) {
            MESSAGE(stdout, gn);
            lastNode = gn;
        }
        job->cmdFILE = stdout;
        /*
         * Only print the commands if they're ok, but don't die if they're
         * not -- just let the user know they're bad and keep going. It
         * doesn't do any harm in this case and may do some good.
         */
        if (cmdsOK) {
            Lst_ForEach(gn->commands, JobPrintCommand, (void *)job);
        }
        /*
         * Don't execute the shell, thank you.
         */
        noExec = TRUE;
    } else {
        /*
         * Just touch the target and note that no shell should be executed.
         * Set cmdFILE to stdout to make life easier. Check the commands, too,
         * but don't die if they're no good -- it does no harm to keep working
         * up the graph.
         */
        job->cmdFILE = stdout;
        Job_Touch(gn, job->flags&JOB_SILENT);
        noExec = TRUE;
    }

    /*
     * If we're not supposed to execute a shell, don't.
     */
    if (noExec) {
        /*
         * Unlink and close the command file if we opened one
         */
        if (job->cmdFILE != stdout) {
            if (job->cmdFILE != NULL)
                (void) fclose(job->cmdFILE);
        } else {
             (void) fflush(stdout);
        }

        /*
         * We only want to work our way up the graph if we aren't here because
         * the commands for the job were no good.
         */
        if (cmdsOK) {
            if (aborting == 0) {
                if (job->tailCmds != NULL) {
                    Lst_ForEachFrom(job->node->commands, job->tailCmds,
                                    JobSaveCommand,
                                   (void *)job->node);
                }
                job->node->made = MADE;
                Make_Update(job->node);
            }
            free(job);
            return(JOB_FINISHED);
        } else {
            free(job);
            return(JOB_ERROR);
        }
    } else {
        (void) fflush(job->cmdFILE);
    }

    /*
     * Set up the control arguments to the shell. This is based on the flags
     * set earlier for this job.
     */
    JobMakeArgv(job, argv);

    /*
     * If we're using pipes to catch output, create the pipe by which we'll
     * get the shell's output. If we're using files, print out that we're
     * starting a job and then set up its temporary-file name.
     */
    if (!compatMake || (job->flags & JOB_FIRST)) {
        if (usePipes) {
            int fd[2];
            if (pipe(fd) == -1)
                Punt("Cannot create pipe: %s", strerror(errno));
            job->inPipe = fd[0];
            job->outPipe = fd[1];
            (void) fcntl(job->inPipe, F_SETFD, 1);
            (void) fcntl(job->outPipe, F_SETFD, 1);
        } else {
            (void) fprintf(stdout, "Remaking `%s'\n", gn->name);
            (void) fflush(stdout);
            (void) strcpy(job->outFile, TMPPAT);
            if ((job->outFd = mkstemp(job->outFile)) == -1)
                Punt("cannot create temp file: %s", strerror(errno));
            (void) fcntl(job->outFd, F_SETFD, 1);
        }
    }

#ifdef REMOTE
    if (!(gn->type & OP_NOEXPORT) && !(runLocalFirst && nLocal < maxLocal)) {
#ifdef RMT_NO_EXEC
        local = !Rmt_Export(shellPath, argv, job);
#else
        local = !Rmt_Begin(shellPath, argv, job->node);
#endif /* RMT_NO_EXEC */
        if (!local) {
            job->flags |= JOB_REMOTE;
        }
    } else
#endif
        local = TRUE;

    if (local && (((nLocal >= maxLocal) &&
        !(job->flags & JOB_SPECIAL) &&
#ifdef REMOTE
        (!(gn->type & OP_NOEXPORT) || (maxLocal != 0))
#else
        (maxLocal != 0)
#endif
        )))
    {
        /*
         * The job can only be run locally, but we've hit the limit of
         * local concurrency, so put the job on hold until some other job
         * finishes. Note that the special jobs (.BEGIN, .INTERRUPT and .END)
         * may be run locally even when the local limit has been reached
         * (e.g. when maxLocal == 0), though they will be exported if at
         * all possible. In addition, any target marked with .NOEXPORT will
         * be run locally if maxLocal is 0.
         */
        jobFull = TRUE;

        DEBUGF(JOB, ("Can only run job locally.\n"));
        job->flags |= JOB_RESTART;
        (void) Lst_AtEnd(stoppedJobs, (void *)job);
    } else {
        if ((nLocal >= maxLocal) && local) {
            /*
             * If we're running this job locally as a special case (see above),
             * at least say the table is full.
             */
            jobFull = TRUE;
            DEBUGF(JOB, ("Local job queue is full.\n"));
        }
        JobExec(job, argv);
    }
    return(JOB_RUNNING);
}

static char *
JobOutput(Job *job, char *cp, char *endp, int msg)
{
    char *ecp;

    if (commandShell->noPrint) {
        ecp = strstr(cp, commandShell->noPrint);
        while (ecp != NULL) {
            if (cp != ecp) {
                *ecp = '\0';
                if (msg && job->node != lastNode) {
                    MESSAGE(stdout, job->node);
                    lastNode = job->node;
                }
                /*
                 * The only way there wouldn't be a newline after
                 * this line is if it were the last in the buffer.
                 * however, since the non-printable comes after it,
                 * there must be a newline, so we don't print one.
                 */
                (void) fprintf(stdout, "%s", cp);
                (void) fflush(stdout);
            }
            cp = ecp + commandShell->noPLen;
            if (cp != endp) {
                /*
                 * Still more to print, look again after skipping
                 * the whitespace following the non-printable
                 * command....
                 */
                cp++;
                while (*cp == ' ' || *cp == '\t' || *cp == '\n') {
                    cp++;
                }
                ecp = strstr(cp, commandShell->noPrint);
            } else {
                return cp;
            }
        }
    }
    return cp;
}

/*-
 *-----------------------------------------------------------------------
 * JobDoOutput  --
 *      This function is called at different times depending on
 *      whether the user has specified that output is to be collected
 *      via pipes or temporary files. In the former case, we are called
 *      whenever there is something to read on the pipe. We collect more
 *      output from the given job and store it in the job's outBuf. If
 *      this makes up a line, we print it tagged by the job's identifier,
 *      as necessary.
 *      If output has been collected in a temporary file, we open the
 *      file and read it line by line, transfering it to our own
 *      output channel until the file is empty. At which point we
 *      remove the temporary file.
 *      In both cases, however, we keep our figurative eye out for the
 *      'noPrint' line for the shell from which the output came. If
 *      we recognize a line, we don't print it. If the command is not
 *      alone on the line (the character after it is not \0 or \n), we
 *      do print whatever follows it.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      curPos may be shifted as may the contents of outBuf.
 *-----------------------------------------------------------------------
 */
STATIC void
JobDoOutput(Job *job, Boolean finish)
{
    Boolean       gotNL = FALSE;  /* true if got a newline */
    Boolean       fbuf;           /* true if our buffer filled up */
    int           nr;             /* number of bytes read */
    int           i;              /* auxiliary index into outBuf */
    int           max;            /* limit for i (end of current data) */
    int           nRead;          /* (Temporary) number of bytes read */

    FILE          *oFILE;         /* Stream pointer to shell's output file */
    char          inLine[132];


    if (usePipes) {
        /*
         * Read as many bytes as will fit in the buffer.
         */
end_loop:
        gotNL = FALSE;
        fbuf = FALSE;

        nRead = read(job->inPipe, &job->outBuf[job->curPos],
                         JOB_BUFSIZE - job->curPos);
        if (nRead < 0) {
            DEBUGF(JOB, ("JobDoOutput(piperead)"));
            nr = 0;
        } else {
            nr = nRead;
        }

        /*
         * If we hit the end-of-file (the job is dead), we must flush its
         * remaining output, so pretend we read a newline if there's any
         * output remaining in the buffer.
         * Also clear the 'finish' flag so we stop looping.
         */
        if ((nr == 0) && (job->curPos != 0)) {
            job->outBuf[job->curPos] = '\n';
            nr = 1;
            finish = FALSE;
        } else if (nr == 0) {
            finish = FALSE;
        }

        /*
         * Look for the last newline in the bytes we just got. If there is
         * one, break out of the loop with 'i' as its index and gotNL set
         * TRUE.
         */
        max = job->curPos + nr;
        for (i = job->curPos + nr - 1; i >= job->curPos; i--) {
            if (job->outBuf[i] == '\n') {
                gotNL = TRUE;
                break;
            } else if (job->outBuf[i] == '\0') {
                /*
                 * Why?
                 */
                job->outBuf[i] = ' ';
            }
        }

        if (!gotNL) {
            job->curPos += nr;
            if (job->curPos == JOB_BUFSIZE) {
                /*
                 * If we've run out of buffer space, we have no choice
                 * but to print the stuff. sigh.
                 */
                fbuf = TRUE;
                i = job->curPos;
            }
        }
        if (gotNL || fbuf) {
            /*
             * Need to send the output to the screen. Null terminate it
             * first, overwriting the newline character if there was one.
             * So long as the line isn't one we should filter (according
             * to the shell description), we print the line, preceded
             * by a target banner if this target isn't the same as the
             * one for which we last printed something.
             * The rest of the data in the buffer are then shifted down
             * to the start of the buffer and curPos is set accordingly.
             */
            job->outBuf[i] = '\0';
            if (i >= job->curPos) {
                char *cp;

                cp = JobOutput(job, job->outBuf, &job->outBuf[i], FALSE);

                /*
                 * There's still more in that thar buffer. This time, though,
                 * we know there's no newline at the end, so we add one of
                 * our own free will.
                 */
                if (*cp != '\0') {
                    if (job->node != lastNode) {
                        MESSAGE(stdout, job->node);
                        lastNode = job->node;
                    }
                    (void) fprintf(stdout, "%s%s", cp, gotNL ? "\n" : "");
                    (void) fflush(stdout);
                }
            }
            if (i < max - 1) {
                /* shift the remaining characters down */
                (void) memcpy(job->outBuf, &job->outBuf[i + 1], max - (i + 1));
                job->curPos = max - (i + 1);

            } else {
                /*
                 * We have written everything out, so we just start over
                 * from the start of the buffer. No copying. No nothing.
                 */
                job->curPos = 0;
            }
        }
        if (finish) {
            /*
             * If the finish flag is true, we must loop until we hit
             * end-of-file on the pipe. This is guaranteed to happen
             * eventually since the other end of the pipe is now closed
             * (we closed it explicitly and the child has exited). When
             * we do get an EOF, finish will be set FALSE and we'll fall
             * through and out.
             */
            goto end_loop;
        }
    } else {
        /*
         * We've been called to retrieve the output of the job from the
         * temporary file where it's been squirreled away. This consists of
         * opening the file, reading the output line by line, being sure not
         * to print the noPrint line for the shell we used, then close and
         * remove the temporary file. Very simple.
         *
         * Change to read in blocks and do FindSubString type things as for
         * pipes? That would allow for "@echo -n..."
         */
        oFILE = fopen(job->outFile, "r");
        if (oFILE != NULL) {
            (void) fprintf(stdout, "Results of making %s:\n", job->node->name);
            (void) fflush(stdout);
            while (fgets(inLine, sizeof(inLine), oFILE) != NULL) {
                char    *cp, *endp, *oendp;

                cp = inLine;
                oendp = endp = inLine + strlen(inLine);
                if (endp[-1] == '\n') {
                    *--endp = '\0';
                }
                cp = JobOutput(job, inLine, endp, FALSE);

                /*
                 * There's still more in that thar buffer. This time, though,
                 * we know there's no newline at the end, so we add one of
                 * our own free will.
                 */
                (void) fprintf(stdout, "%s", cp);
                (void) fflush(stdout);
                if (endp != oendp) {
                    (void) fprintf(stdout, "\n");
                    (void) fflush(stdout);
                }
            }
            (void) fclose(oFILE);
            (void) eunlink(job->outFile);
        }
    }
}

/*-
 *-----------------------------------------------------------------------
 * Job_CatchChildren --
 *      Handle the exit of a child. Called from Make_Make.
 *
 * Results:
 *      none.
 *
 * Side Effects:
 *      The job descriptor is removed from the list of children.
 *
 * Notes:
 *      We do waits, blocking or not, according to the wisdom of our
 *      caller, until there are no more children to report. For each
 *      job, call JobFinish to finish things off. This will take care of
 *      putting jobs on the stoppedJobs queue.
 *
 *-----------------------------------------------------------------------
 */
void
Job_CatchChildren(Boolean block)
{
    int           pid;          /* pid of dead child */
    Job           *job;         /* job descriptor for dead child */
    LstNode       jnode;        /* list element for finding job */
    int           status;       /* Exit/termination status */

    /*
     * Don't even bother if we know there's no one around.
     */
    if (nLocal == 0) {
        return;
    }

    while ((pid = waitpid((pid_t) -1, &status,
                          (block?0:WNOHANG)|WUNTRACED)) > 0)
    {
        DEBUGF(JOB, ("Process %d exited or stopped.\n", pid));

        jnode = Lst_Find(jobs, (void *)&pid, JobCmpPid);

        if (jnode == NULL) {
            if (WIFSIGNALED(status) && (WTERMSIG(status) == SIGCONT)) {
                jnode = Lst_Find(stoppedJobs, (void *) &pid, JobCmpPid);
                if (jnode == NULL) {
                    Error("Resumed child (%d) not in table", pid);
                    continue;
                }
                job = (Job *)Lst_Datum(jnode);
                (void) Lst_Remove(stoppedJobs, jnode);
            } else {
                Error("Child (%d) not in table?", pid);
                continue;
            }
        } else {
            job = (Job *) Lst_Datum(jnode);
            (void) Lst_Remove(jobs, jnode);
            nJobs -= 1;
            DEBUGF(JOB, ("Job queue is no longer full.\n"));
            jobFull = FALSE;
#ifdef REMOTE
            if (!(job->flags & JOB_REMOTE)) {
                DEBUGF(JOB, ("Job queue has one fewer local process.\n"));
                nLocal -= 1;
            }
#else
            nLocal -= 1;
#endif
        }

        JobFinish(job, &status);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Job_CatchOutput --
 *      Catch the output from our children, if we're using
 *      pipes do so. Otherwise just block time until we get a
 *      signal (most likely a SIGCHLD) since there's no point in
 *      just spinning when there's nothing to do and the reaping
 *      of a child can wait for a while.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Output is read from pipes if we're piping.
 * -----------------------------------------------------------------------
 */
void
Job_CatchOutput(void)
{
    int                   nfds;
    struct timeval        timeout;
    fd_set                readfds;
    LstNode               ln;
    Job                   *job;
#ifdef RMT_WILL_WATCH
    int                   pnJobs;       /* Previous nJobs */
#endif

    (void) fflush(stdout);
#ifdef RMT_WILL_WATCH
    pnJobs = nJobs;

    /*
     * It is possible for us to be called with nJobs equal to 0. This happens
     * if all the jobs finish and a job that is stopped cannot be run
     * locally (eg if maxLocal is 0) and cannot be exported. The job will
     * be placed back on the stoppedJobs queue, Job_Empty() will return false,
     * Make_Run will call us again when there's nothing for which to wait.
     * nJobs never changes, so we loop forever. Hence the check. It could
     * be argued that we should sleep for a bit so as not to swamp the
     * exportation system with requests. Perhaps we should.
     *
     * NOTE: IT IS THE RESPONSIBILITY OF Rmt_Wait TO CALL Job_CatchChildren
     * IN A TIMELY FASHION TO CATCH ANY LOCALLY RUNNING JOBS THAT EXIT.
     * It may use the variable nLocal to determine if it needs to call
     * Job_CatchChildren (if nLocal is 0, there's nothing for which to
     * wait...)
     */
    while (nJobs != 0 && pnJobs == nJobs) {
        Rmt_Wait();
    }
#else
    if (usePipes) {
        readfds = outputs;
        timeout.tv_sec = SEL_SEC;
        timeout.tv_usec = SEL_USEC;

        if ((nfds = select(FD_SETSIZE, &readfds, (fd_set *) 0,
                           (fd_set *) 0, &timeout)) <= 0)
            return;
        else {
            if (Lst_Open(jobs) == FAILURE) {
                Punt("Cannot open job table");
            }
            while (nfds && (ln = Lst_Next(jobs)) != NULL) {
                job = (Job *) Lst_Datum(ln);
                if (FD_ISSET(job->inPipe, &readfds)) {
                    JobDoOutput(job, FALSE);
                    nfds -= 1;
                }
            }
            Lst_Close(jobs);
        }
    }
#endif /* RMT_WILL_WATCH */
}

/*-
 *-----------------------------------------------------------------------
 * Job_Make --
 *      Start the creation of a target. Basically a front-end for
 *      JobStart used by the Make module.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      Another job is started.
 *
 *-----------------------------------------------------------------------
 */
void
Job_Make(GNode *gn)
{
    (void) JobStart(gn, 0, NULL);
}

/*-
 *-----------------------------------------------------------------------
 * Job_Init --
 *      Initialize the process module, given a maximum number of jobs, and
 *      a maximum number of local jobs.
 *
 * Results:
 *      none
 *
 * Side Effects:
 *      lists and counters are initialized
 *-----------------------------------------------------------------------
 */
void
Job_Init(int maxproc, int maxlocal)
{
    GNode         *begin;     /* node for commands to do at the very start */

    jobs =        Lst_Init(FALSE);
    stoppedJobs = Lst_Init(FALSE);
    maxJobs =     maxproc;
    maxLocal =    maxlocal;
    nJobs =       0;
    nLocal =      0;
    jobFull =     FALSE;

    aborting =    0;
    errors =      0;

    lastNode =    NULL;

    if (maxJobs == 1 || beVerbose == 0
#ifdef REMOTE
        || noMessages
#endif
                     ) {
        /*
         * If only one job can run at a time, there's no need for a banner,
         * no is there?
         */
        targFmt = "";
    } else {
        targFmt = TARG_FMT;
    }

    if (shellPath == NULL) {
        /*
         * The user didn't specify a shell to use, so we are using the
         * default one... Both the absolute path and the last component
         * must be set. The last component is taken from the 'name' field
         * of the default shell description pointed-to by commandShell.
         * All default shells are located in _PATH_DEFSHELLDIR.
         */
        shellName = commandShell->name;
        shellPath = str_concat(_PATH_DEFSHELLDIR, shellName, STR_ADDSLASH);
    }

    if (commandShell->exit == NULL) {
        commandShell->exit = "";
    }
    if (commandShell->echo == NULL) {
        commandShell->echo = "";
    }

    /*
     * Catch the four signals that POSIX specifies if they aren't ignored.
     * JobPassSig will take care of calling JobInterrupt if appropriate.
     */
    if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGINT, JobPassSig);
    }
    if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGHUP, JobPassSig);
    }
    if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGQUIT, JobPassSig);
    }
    if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGTERM, JobPassSig);
    }
    /*
     * There are additional signals that need to be caught and passed if
     * either the export system wants to be told directly of signals or if
     * we're giving each job its own process group (since then it won't get
     * signals from the terminal driver as we own the terminal)
     */
#if defined(RMT_WANTS_SIGNALS) || defined(USE_PGRP)
    if (signal(SIGTSTP, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGTSTP, JobPassSig);
    }
    if (signal(SIGTTOU, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGTTOU, JobPassSig);
    }
    if (signal(SIGTTIN, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGTTIN, JobPassSig);
    }
    if (signal(SIGWINCH, SIG_IGN) != SIG_IGN) {
        (void) signal(SIGWINCH, JobPassSig);
    }
#endif

    begin = Targ_FindNode(".BEGIN", TARG_NOCREATE);

    if (begin != NULL) {
        JobStart(begin, JOB_SPECIAL, (Job *)0);
        while (nJobs) {
            Job_CatchOutput();
#ifndef RMT_WILL_WATCH
            Job_CatchChildren(!usePipes);
#endif /* RMT_WILL_WATCH */
        }
    }
    postCommands = Targ_FindNode(".END", TARG_CREATE);
}

/*-
 *-----------------------------------------------------------------------
 * Job_Full --
 *      See if the job table is full. It is considered full if it is OR
 *      if we are in the process of aborting OR if we have
 *      reached/exceeded our local quota. This prevents any more jobs
 *      from starting up.
 *
 * Results:
 *      TRUE if the job table is full, FALSE otherwise
 * Side Effects:
 *      None.
 *-----------------------------------------------------------------------
 */
Boolean
Job_Full(void)
{
    return(aborting || jobFull);
}

/*-
 *-----------------------------------------------------------------------
 * Job_Empty --
 *      See if the job table is empty.  Because the local concurrency may
 *      be set to 0, it is possible for the job table to become empty,
 *      while the list of stoppedJobs remains non-empty. In such a case,
 *      we want to restart as many jobs as we can.
 *
 * Results:
 *      TRUE if it is. FALSE if it ain't.
 *
 * Side Effects:
 *      None.
 *
 * -----------------------------------------------------------------------
 */
Boolean
Job_Empty(void)
{
    if (nJobs == 0) {
        if (!Lst_IsEmpty(stoppedJobs) && !aborting) {
            /*
             * The job table is obviously not full if it has no jobs in
             * it...Try and restart the stopped jobs.
             */
            jobFull = FALSE;
            JobRestartJobs();
            return(FALSE);
        } else {
            return(TRUE);
        }
    } else {
        return(FALSE);
    }
}

/*-
 *-----------------------------------------------------------------------
 * JobMatchShell --
 *      Find a matching shell in 'shells' given its final component.
 *
 * Results:
 *      A pointer to the Shell structure.
 *
 * Side Effects:
 *      None.
 *
 *-----------------------------------------------------------------------
 */
static Shell *
JobMatchShell(char *name)
{
    Shell         *sh;        /* Pointer into shells table */
    Shell         *match;     /* Longest-matching shell */
    char          *cp1,
                  *cp2;
    char          *eoname;

    eoname = name + strlen(name);

    match = NULL;

    for (sh = shells; sh->name != NULL; sh++) {
        for (cp1 = eoname - strlen(sh->name), cp2 = sh->name;
             *cp1 != '\0' && *cp1 == *cp2;
             cp1++, cp2++) {
                 continue;
        }
        if (*cp1 != *cp2) {
            continue;
        } else if (match == NULL || strlen(match->name) < strlen(sh->name)) {
           match = sh;
        }
    }
    return(match == NULL ? sh : match);
}

/*-
 *-----------------------------------------------------------------------
 * Job_ParseShell --
 *      Parse a shell specification and set up commandShell, shellPath
 *      and shellName appropriately.
 *
 * Results:
 *      FAILURE if the specification was incorrect.
 *
 * Side Effects:
 *      commandShell points to a Shell structure (either predefined or
 *      created from the shell spec), shellPath is the full path of the
 *      shell described by commandShell, while shellName is just the
 *      final component of shellPath.
 *
 * Notes:
 *      A shell specification consists of a .SHELL target, with dependency
 *      operator, followed by a series of blank-separated words. Double
 *      quotes can be used to use blanks in words. A backslash escapes
 *      anything (most notably a double-quote and a space) and
 *      provides the functionality it does in C. Each word consists of
 *      keyword and value separated by an equal sign. There should be no
 *      unnecessary spaces in the word. The keywords are as follows:
 *          name            Name of shell.
 *          path            Location of shell. Overrides "name" if given
 *          quiet           Command to turn off echoing.
 *          echo            Command to turn echoing on
 *          filter          Result of turning off echoing that shouldn't be
 *                          printed.
 *          echoFlag        Flag to turn echoing on at the start
 *          errFlag         Flag to turn error checking on at the start
 *          hasErrCtl       True if shell has error checking control
 *          check           Command to turn on error checking if hasErrCtl
 *                          is TRUE or template of command to echo a command
 *                          for which error checking is off if hasErrCtl is
 *                          FALSE.
 *          ignore          Command to turn off error checking if hasErrCtl
 *                          is TRUE or template of command to execute a
 *                          command so as to ignore any errors it returns if
 *                          hasErrCtl is FALSE.
 *
 *-----------------------------------------------------------------------
 */
ReturnStatus
Job_ParseShell(char *line)
{
    char          **words;
    int           wordCount;
    char          **argv;
    int           argc;
    char          *path;
    Shell         newShell;
    Boolean       fullSpec = FALSE;

    while (isspace((unsigned char) *line)) {
        line++;
    }
    words = brk_string(line, &wordCount, TRUE);

    memset(&newShell, 0, sizeof(newShell));

    /*
     * Parse the specification by keyword
     */
    for (path = NULL, argc = wordCount - 1, argv = words + 1;
         argc != 0;
         argc--, argv++) {
             if (strncmp(*argv, "path=", 5) == 0) {
                 path = &argv[0][5];
             } else if (strncmp(*argv, "name=", 5) == 0) {
                 newShell.name = &argv[0][5];
             } else {
                 if (strncmp(*argv, "quiet=", 6) == 0) {
                     newShell.echoOff = &argv[0][6];
                 } else if (strncmp(*argv, "echo=", 5) == 0) {
                     newShell.echoOn = &argv[0][5];
                 } else if (strncmp(*argv, "filter=", 7) == 0) {
                     newShell.noPrint = &argv[0][7];
                     newShell.noPLen = strlen(newShell.noPrint);
                 } else if (strncmp(*argv, "echoFlag=", 9) == 0) {
                     newShell.echo = &argv[0][9];
                 } else if (strncmp(*argv, "errFlag=", 8) == 0) {
                     newShell.exit = &argv[0][8];
                 } else if (strncmp(*argv, "hasErrCtl=", 10) == 0) {
                     char c = argv[0][10];
                     newShell.hasErrCtl = !((c != 'Y') && (c != 'y') &&
                                           (c != 'T') && (c != 't'));
                 } else if (strncmp(*argv, "check=", 6) == 0) {
                     newShell.errCheck = &argv[0][6];
                 } else if (strncmp(*argv, "ignore=", 7) == 0) {
                     newShell.ignErr = &argv[0][7];
                 } else {
                     Parse_Error(PARSE_FATAL, "Unknown keyword \"%s\"",
                                  *argv);
                     return(FAILURE);
                 }
                 fullSpec = TRUE;
             }
    }

    if (path == NULL) {
        /*
         * If no path was given, the user wants one of the pre-defined shells,
         * yes? So we find the one s/he wants with the help of JobMatchShell
         * and set things up the right way. shellPath will be set up by
         * Job_Init.
         */
        if (newShell.name == NULL) {
            Parse_Error(PARSE_FATAL, "Neither path nor name specified");
            return(FAILURE);
        } else {
            commandShell = JobMatchShell(newShell.name);
            shellName = newShell.name;
        }
    } else {
        /*
         * The user provided a path. If s/he gave nothing else (fullSpec is
         * FALSE), try and find a matching shell in the ones we know of.
         * Else we just take the specification at its word and copy it
         * to a new location. In either case, we need to record the
         * path the user gave for the shell.
         */
        shellPath = path;
        path = strrchr(path, '/');
        if (path == NULL) {
            path = shellPath;
        } else {
            path += 1;
        }
        if (newShell.name != NULL) {
            shellName = newShell.name;
        } else {
            shellName = path;
        }
        if (!fullSpec) {
            commandShell = JobMatchShell(shellName);
        } else {
            commandShell = (Shell *) emalloc(sizeof(Shell));
            *commandShell = newShell;
        }
    }

    if (commandShell->echoOn && commandShell->echoOff) {
        commandShell->hasEchoCtl = TRUE;
    }

    if (!commandShell->hasErrCtl) {
        if (commandShell->errCheck == NULL) {
            commandShell->errCheck = "";
        }
        if (commandShell->ignErr == NULL) {
            commandShell->ignErr = "%s\n";
        }
    }
    return SUCCESS;
}

/*-
 *-----------------------------------------------------------------------
 * JobInterrupt --
 *      Handle the receipt of an interrupt.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      All children are killed. Another job will be started if the
 *      .INTERRUPT target was given.
 *-----------------------------------------------------------------------
 */
static void
JobInterrupt(int runINTERRUPT, int signo)
{
    LstNode       ln;           /* element in job table */
    Job           *job = NULL;  /* job descriptor in that element */
    GNode         *interrupt;   /* the node describing the .INTERRUPT target */

    aborting = ABORT_INTERRUPT;

   (void) Lst_Open(jobs);
    while ((ln = Lst_Next(jobs)) != NULL) {
        job = (Job *) Lst_Datum(ln);

        if (!Targ_Precious(job->node)) {
            char        *file = (job->node->path == NULL ?
                                 job->node->name :
                                 job->node->path);
            if (!noExecute && eunlink(file) != -1) {
                Error("*** %s removed", file);
            }
        }
#ifdef RMT_WANTS_SIGNALS
        if (job->flags & JOB_REMOTE) {
            /*
             * If job is remote, let the Rmt module do the killing.
             */
            if (!Rmt_Signal(job, signo)) {
                /*
                 * If couldn't kill the thing, finish it out now with an
                 * error code, since no exit report will come in likely.
                 */
                int status;

                status.w_status = 0;
                status.w_retcode = 1;
                JobFinish(job, &status);
            }
        } else if (job->pid) {
            KILL(job->pid, signo);
        }
#else
        if (job->pid) {
            DEBUGF(JOB, ("JobInterrupt passing signal to child %d.\n",
                   job->pid));
            KILL(job->pid, signo);
        }
#endif /* RMT_WANTS_SIGNALS */
    }

#ifdef REMOTE
   (void)Lst_Open(stoppedJobs);
    while ((ln = Lst_Next(stoppedJobs)) != NULL) {
        job = (Job *) Lst_Datum(ln);

        if (job->flags & JOB_RESTART) {
            DEBUGF(JOB, "JobInterrupt skipping job on stopped queue"
                   "-- it was waiting to be restarted.\n");
            continue;
        }
        if (!Targ_Precious(job->node)) {
            char        *file = (job->node->path == NULL ?
                                 job->node->name :
                                 job->node->path);
            if (eunlink(file) == 0) {
                Error("*** %s removed", file);
            }
        }
        /*
         * Resume the thing so it will take the signal.
         */
        DEBUGF(JOB, ("JobInterrupt passing CONT to stopped child %d.\n", job->pid));
        KILL(job->pid, SIGCONT);
#ifdef RMT_WANTS_SIGNALS
        if (job->flags & JOB_REMOTE) {
            /*
             * If job is remote, let the Rmt module do the killing.
             */
            if (!Rmt_Signal(job, SIGINT)) {
                /*
                 * If couldn't kill the thing, finish it out now with an
                 * error code, since no exit report will come in likely.
                 */
                int status;
                status.w_status = 0;
                status.w_retcode = 1;
                JobFinish(job, &status);
            }
        } else if (job->pid) {
            DEBUGF(JOB, "JobInterrupt passing interrupt to stopped child %d.\n",
                   job->pid);
            KILL(job->pid, SIGINT);
        }
#endif /* RMT_WANTS_SIGNALS */
    }
#endif
    Lst_Close(stoppedJobs);

    if (runINTERRUPT && !touchFlag) {
        interrupt = Targ_FindNode(".INTERRUPT", TARG_NOCREATE);
        if (interrupt != NULL) {
            ignoreErrors = FALSE;

            JobStart(interrupt, JOB_IGNDOTS, (Job *)0);
            while (nJobs) {
                Job_CatchOutput();
#ifndef RMT_WILL_WATCH
                Job_CatchChildren(!usePipes);
#endif /* RMT_WILL_WATCH */
            }
        }
    }
}

/*
 *-----------------------------------------------------------------------
 * Job_Finish --
 *      Do final processing such as the running of the commands
 *      attached to the .END target.
 *
 * Results:
 *      Number of errors reported.
 *-----------------------------------------------------------------------
 */
int
Job_Finish(void)
{
    if (postCommands != NULL && !Lst_IsEmpty(postCommands->commands)) {
        if (errors) {
            Error("Errors reported so .END ignored");
        } else {
            JobStart(postCommands, JOB_SPECIAL | JOB_IGNDOTS, NULL);

            while (nJobs) {
                Job_CatchOutput();
#ifndef RMT_WILL_WATCH
                Job_CatchChildren(!usePipes);
#endif /* RMT_WILL_WATCH */
            }
        }
    }
    return(errors);
}

/*-
 *-----------------------------------------------------------------------
 * Job_Wait --
 *      Waits for all running jobs to finish and returns. Sets 'aborting'
 *      to ABORT_WAIT to prevent other jobs from starting.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      Currently running jobs finish.
 *
 *-----------------------------------------------------------------------
 */
void
Job_Wait(void)
{
    aborting = ABORT_WAIT;
    while (nJobs != 0) {
        Job_CatchOutput();
#ifndef RMT_WILL_WATCH
        Job_CatchChildren(!usePipes);
#endif /* RMT_WILL_WATCH */
    }
    aborting = 0;
}

/*-
 *-----------------------------------------------------------------------
 * Job_AbortAll --
 *      Abort all currently running jobs without handling output or anything.
 *      This function is to be called only in the event of a major
 *      error. Most definitely NOT to be called from JobInterrupt.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      All children are killed, not just the firstborn
 *-----------------------------------------------------------------------
 */
void
Job_AbortAll(void)
{
    LstNode             ln;     /* element in job table */
    Job                 *job;   /* the job descriptor in that element */
    int                 foo;

    aborting = ABORT_ERROR;

    if (nJobs) {

        (void) Lst_Open(jobs);
        while ((ln = Lst_Next(jobs)) != NULL) {
            job = (Job *) Lst_Datum(ln);

            /*
             * kill the child process with increasingly drastic signals to make
             * darn sure it's dead.
             */
#ifdef RMT_WANTS_SIGNALS
            if (job->flags & JOB_REMOTE) {
                Rmt_Signal(job, SIGINT);
                Rmt_Signal(job, SIGKILL);
            } else {
                KILL(job->pid, SIGINT);
                KILL(job->pid, SIGKILL);
            }
#else
            KILL(job->pid, SIGINT);
            KILL(job->pid, SIGKILL);
#endif /* RMT_WANTS_SIGNALS */
        }
    }

    /*
     * Catch as many children as want to report in at first, then give up
     */
    while (waitpid((pid_t) -1, &foo, WNOHANG) > 0)
        continue;
}

#ifdef REMOTE
/*-
 *-----------------------------------------------------------------------
 * JobFlagForMigration --
 *      Handle the eviction of a child. Called from RmtStatusChange.
 *      Flags the child as remigratable and then suspends it.  Takes
 *      the ID of the host we used, for matching children.
 *
 * Results:
 *      none.
 *
 * Side Effects:
 *      The job descriptor is flagged for remigration.
 *
 *-----------------------------------------------------------------------
 */
void
JobFlagForMigration(int hostID)
{
    Job           *job;         /* job descriptor for dead child */
    LstNode       jnode;        /* list element for finding job */

    DEBUGF(JOB, ("JobFlagForMigration(%d) called.\n", hostID));
    jnode = Lst_Find(jobs, (void *)hostID, JobCmpRmtID);

    if (jnode == NULL) {
        jnode = Lst_Find(stoppedJobs, (void *)hostID, JobCmpRmtID);
                if (jnode == NULL) {
                    if (DEBUG(JOB)) {
                        Error("Evicting host(%d) not in table", hostID);
                    }
                    return;
                }
    }
    job = (Job *) Lst_Datum(jnode);

    DEBUGF(JOB, ("JobFlagForMigration(%d) found job '%s'.\n", hostID, job->node->name));

    KILL(job->pid, SIGSTOP);

    job->flags |= JOB_REMIGRATE;
}

#endif
\f
/*-
 *-----------------------------------------------------------------------
 * JobRestartJobs --
 *      Tries to restart stopped jobs if there are slots available.
 *      Note that this tries to restart them regardless of pending errors.
 *      It's not good to leave stopped jobs lying around!
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      Resumes(and possibly migrates) jobs.
 *
 *-----------------------------------------------------------------------
 */
static void
JobRestartJobs(void)
{
    while (!jobFull && !Lst_IsEmpty(stoppedJobs)) {
        DEBUGF(JOB, ("Job queue is not full. Restarting a stopped job.\n"));
        JobRestart((Job *)Lst_DeQueue(stoppedJobs));
    }
}