/*      $NetBSD: job.c,v 1.529 2026/04/06 17:13:54 rillig Exp $ */

/*
 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
 * 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. 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.
 */

/*
 * 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.
 */

/*
 * Create child processes and collect their output.
 *
 * Interface:
 *      Job_Init        Initialize this module and make the .BEGIN target.
 *
 *      Job_End         Clean up any memory used.
 *
 *      Job_Make        Start making the given target.
 *
 *      Job_CatchChildren
 *                      Handle the termination of any children.
 *
 *      Job_CatchOutput
 *                      Print any output the child processes have produced.
 *
 *      Job_ParseShell  Given a special dependency line with target '.SHELL',
 *                      define the shell that is used for the creation
 *                      commands in jobs mode.
 *
 *      Job_MakeDotEnd  Make the .END target. Must only be called when the
 *                      job table is empty.
 *
 *      Job_AbortAll    Kill all currently running jobs, in an emergency.
 *
 *      Job_CheckCommands
 *                      Add fallback commands to a target, if necessary.
 *
 *      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/time.h>
#include <sys/wait.h>

#include <errno.h>
#ifndef USE_SELECT
#include <poll.h>
#endif
#include <signal.h>
#include <utime.h>

#include "make.h"
#include "dir.h"
#include "job.h"
#ifdef USE_META
# include "meta.h"
#endif
#include "pathnames.h"
#include "trace.h"

/*      "@(#)job.c      8.2 (Berkeley) 3/19/94" */
MAKE_RCSID("$NetBSD: job.c,v 1.529 2026/04/06 17:13:54 rillig Exp $");


#ifdef USE_SELECT
/*
 * Emulate poll() in terms of select().  This is not a complete
 * emulation but it is sufficient for make's purposes.
 */

#define poll emul_poll
#define pollfd emul_pollfd

struct emul_pollfd {
        int fd;
        short events;
        short revents;
};

#define POLLIN          0x0001
#define POLLOUT         0x0004

int emul_poll(struct pollfd *, int, int);
#endif

struct pollfd;


enum JobStatus {
        JOB_ST_FREE,            /* Job is available */
        JOB_ST_SET_UP,          /* Job is allocated but otherwise invalid */
        JOB_ST_RUNNING,         /* Job is running, pid valid */
        JOB_ST_FINISHED         /* Job is done (i.e. after SIGCHLD) */
};

static const char JobStatus_Name[][9] = {
        "free",
        "set-up",
        "running",
        "finished",
};

/*
 * A Job manages the shell commands that are run to create a single target.
 * Each job is run in a separate subprocess by a shell.  Several jobs can run
 * in parallel.
 *
 * The shell commands for the target are written to a temporary file,
 * then the shell is run with the temporary file as stdin, and the output
 * of that shell is captured via a pipe.
 *
 * When a job is finished, Make_Update updates all parents of the node
 * that was just remade, marking them as ready to be made next if all
 * other dependencies are finished as well.
 */
struct Job {
        /* The process ID of the shell running the commands */
        int pid;

        /* The target the child is making */
        GNode *node;

        /*
         * If one of the shell commands is "...", all following commands are
         * delayed until the .END node is made.  This list node points to the
         * first of these commands, if any.
         */
        StringListNode *tailCmds;

        /* This is where the shell commands go. */
        FILE *cmdFILE;

        int exit_status;        /* from wait4() in signal handler */

        enum JobStatus status;

        bool suspended;

        /* Ignore non-zero exits */
        bool ignerr;
        /* Output the command before or instead of running it. */
        bool echo;
        /* Target is a special one. */
        bool special;

        int inPipe;             /* Pipe for reading output from job */
        int outPipe;            /* Pipe for writing control commands */
        struct pollfd *inPollfd; /* pollfd associated with inPipe */

#define JOB_BUFSIZE     1024
        /* Buffer for storing the output of the job, line by line. */
        char outBuf[JOB_BUFSIZE + 1];
        size_t outBufLen;

#ifdef USE_META
        struct BuildMon bm;
#endif
};


/*
 * A shell defines how the commands are run.  All commands for a target are
 * written into a single file, which is then given to the shell to execute
 * the commands from it.  The commands are written to the file using a few
 * templates for echo control and error control.
 *
 * The name of the shell is the basename for the predefined shells, such as
 * "sh", "csh", "bash".  For custom shells, it is the full pathname, and its
 * basename is used to select the type of shell; the longest match wins.
 * So /usr/pkg/bin/bash has type sh, /usr/local/bin/tcsh has type csh.
 *
 * The echoing of command lines is controlled using hasEchoCtl, echoOff,
 * echoOn, noPrint and noPrintLen.  When echoOff is executed by the shell, it
 * still outputs something, but this something is not interesting, therefore
 * it is filtered out using noPrint and noPrintLen.
 *
 * The error checking for individual commands is controlled using hasErrCtl,
 * errOn, errOff and runChkTmpl.
 *
 * In case a shell doesn't have error control, echoTmpl is a printf template
 * for echoing the command, should echoing be on; runIgnTmpl is another
 * printf template for executing the command while ignoring the return
 * status. Finally runChkTmpl is a printf template for running the command and
 * causing the shell to exit on error. If any of these strings are empty when
 * hasErrCtl is false, the command will be executed anyway as is, and if it
 * causes an error, so be it. Any templates set up to echo the command will
 * escape any '$ ` \ "' characters in the command string to avoid unwanted
 * shell code injection, the escaped command is safe to use in double quotes.
 *
 * The command-line flags "echo" and "exit" also control the behavior.  The
 * "echo" flag causes the shell to start echoing commands right away.  The
 * "exit" flag causes the shell to exit when an error is detected in one of
 * the commands.
 */
typedef struct Shell {

        /*
         * The name of the shell. For Bourne and C shells, this is used only
         * to find the shell description when used as the single source of a
         * .SHELL target. For user-defined shells, this is the full path of
         * the shell.
         */
        const char *name;

        bool hasEchoCtl;        /* whether both echoOff and echoOn are there */
        const char *echoOff;    /* command to turn echoing off */
        const char *echoOn;     /* command to turn echoing back on */
        const char *noPrint;    /* text to skip when printing output from the
                                 * shell. This is usually the same as echoOff */
        size_t noPrintLen;      /* length of noPrint command */

        bool hasErrCtl;         /* whether error checking can be controlled
                                 * for individual commands */
        const char *errOn;      /* command to turn on error checking */
        const char *errOff;     /* command to turn off error checking */

        const char *echoTmpl;   /* template to echo a command */
        const char *runIgnTmpl; /* template to run a command without error
                                 * checking */
        const char *runChkTmpl; /* template to run a command with error
                                 * checking */

        /*
         * A string literal that results in a newline character when it
         * occurs outside of any 'quote' or "quote" characters.
         */
        const char *newline;
        char commentChar;       /* character used by shell for comment lines */

        const char *echoFlag;   /* shell flag to echo commands */
        const char *errFlag;    /* shell flag to exit on error */
} Shell;

typedef struct CommandFlags {
        /* Whether to echo the command before or instead of running it. */
        bool echo;

        /* Run the command even in -n or -N mode. */
        bool always;

        /*
         * true if we turned error checking off before writing the command to
         * the commands file and need to turn it back on
         */
        bool ignerr;
} CommandFlags;

/*
 * Write shell commands to a file.
 *
 * TODO: keep track of whether commands are echoed.
 * TODO: keep track of whether error checking is active.
 */
typedef struct ShellWriter {
        FILE *f;

        /* we've sent 'set -x' */
        bool xtraced;

} ShellWriter;

/* error handling variables */
static int job_errors = 0;      /* number of errors reported */
static enum {                   /* Why is the make aborting? */
        ABORT_NONE,
        ABORT_ERROR,            /* Aborted because of an error */
        ABORT_INTERRUPT,        /* Aborted because it was interrupted */
        ABORT_WAIT              /* Waiting for jobs to finish */
} aborting = ABORT_NONE;
#define JOB_TOKENS "+EI+"       /* Token to requeue for each abort state */

static const char aborting_name[][6] = { "NONE", "ERROR", "INTR", "WAIT" };

/* Tracks the number of tokens currently "out" to build jobs. */
int jobTokensRunning = 0;

/*
 * Descriptions for various shells.
 *
 * The build environment may set DEFSHELL_INDEX to one of
 * DEFSHELL_INDEX_SH, DEFSHELL_INDEX_KSH, or DEFSHELL_INDEX_CSH, to
 * select one of the predefined shells as the default shell.
 *
 * Alternatively, the build environment may set DEFSHELL_CUSTOM to the
 * name or the full path of a sh-compatible shell, which will be used as
 * the default shell.
 *
 * ".SHELL" lines in Makefiles can choose the default shell from the
 * set defined here, or add additional shells.
 */

#ifdef DEFSHELL_CUSTOM
#define DEFSHELL_INDEX_CUSTOM 0
#define DEFSHELL_INDEX_SH     1
#define DEFSHELL_INDEX_KSH    2
#define DEFSHELL_INDEX_CSH    3
#else
#define DEFSHELL_INDEX_SH     0
#define DEFSHELL_INDEX_KSH    1
#define DEFSHELL_INDEX_CSH    2
#endif

#ifndef DEFSHELL_INDEX
#define DEFSHELL_INDEX 0        /* DEFSHELL_INDEX_CUSTOM or DEFSHELL_INDEX_SH */
#endif

static Shell shells[] = {
#ifdef DEFSHELL_CUSTOM
    /*
     * An sh-compatible shell with a non-standard name.
     *
     * Keep this in sync with the "sh" description below, but avoid
     * non-portable features that might not be supplied by all
     * sh-compatible shells.
     */
    {
        DEFSHELL_CUSTOM,        /* .name */
        false,                  /* .hasEchoCtl */
        "",                     /* .echoOff */
        "",                     /* .echoOn */
        "",                     /* .noPrint */
        0,                      /* .noPrintLen */
        false,                  /* .hasErrCtl */
        "",                     /* .errOn */
        "",                     /* .errOff */
        "echo \"%s\"\n",        /* .echoTmpl */
        "%s\n",                 /* .runIgnTmpl */
        "{ %s \n} || exit $?\n", /* .runChkTmpl */
        "'\n'",                 /* .newline */
        '#',                    /* .commentChar */
        "",                     /* .echoFlag */
        "",                     /* .errFlag */
    },
#endif /* DEFSHELL_CUSTOM */
    /*
     * SH description. Echo control is also possible and, under
     * sun UNIX anyway, one can even control error checking.
     */
    {
        "sh",                   /* .name */
        false,                  /* .hasEchoCtl */
        "",                     /* .echoOff */
        "",                     /* .echoOn */
        "",                     /* .noPrint */
        0,                      /* .noPrintLen */
        false,                  /* .hasErrCtl */
        "",                     /* .errOn */
        "",                     /* .errOff */
        "echo \"%s\"\n",        /* .echoTmpl */
        "%s\n",                 /* .runIgnTmpl */
        "{ %s \n} || exit $?\n", /* .runChkTmpl */
        "'\n'",                 /* .newline */
        '#',                    /* .commentChar*/
#if defined(MAKE_NATIVE) && defined(__NetBSD__)
        /* XXX: -q is not really echoFlag, it's more like noEchoInSysFlag. */
        "q",                    /* .echoFlag */
#else
        "",                     /* .echoFlag */
#endif
        "",                     /* .errFlag */
    },
    /*
     * KSH description.
     */
    {
        "ksh",                  /* .name */
        true,                   /* .hasEchoCtl */
        "set +v",               /* .echoOff */
        "set -v",               /* .echoOn */
        "set +v",               /* .noPrint */
        6,                      /* .noPrintLen */
        false,                  /* .hasErrCtl */
        "",                     /* .errOn */
        "",                     /* .errOff */
        "echo \"%s\"\n",        /* .echoTmpl */
        "%s\n",                 /* .runIgnTmpl */
        "{ %s \n} || exit $?\n", /* .runChkTmpl */
        "'\n'",                 /* .newline */
        '#',                    /* .commentChar */
        "v",                    /* .echoFlag */
        "",                     /* .errFlag */
    },
    /*
     * 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",                  /* .name */
        true,                   /* .hasEchoCtl */
        "unset verbose",        /* .echoOff */
        "set verbose",          /* .echoOn */
        "unset verbose",        /* .noPrint */
        13,                     /* .noPrintLen */
        false,                  /* .hasErrCtl */
        "",                     /* .errOn */
        "",                     /* .errOff */
        "echo \"%s\"\n",        /* .echoTmpl */
        "csh -c \"%s || exit 0\"\n", /* .runIgnTmpl */
        "",                     /* .runChkTmpl */
        "'\\\n'",               /* .newline */
        '#',                    /* .commentChar */
        "v",                    /* .echoFlag */
        "e",                    /* .errFlag */
    }
};

/*
 * This is the shell to which we pass all commands in the Makefile.
 * It is set by the Job_ParseShell function.
 */
static Shell *shell = &shells[DEFSHELL_INDEX];
char *shellPath;                /* full pathname of executable image */
const char *shellName = NULL;   /* last component of shellPath */
char *shellErrFlag = NULL;
static char *shell_freeIt = NULL; /* Allocated memory for custom .SHELL */


static Job *job_table;          /* The structures that describe them */
static Job *job_table_end;      /* job_table + maxJobs */
static bool wantToken;
static bool lurking_children = false;
static bool make_suspended = false; /* Whether we've seen a SIGTSTP (etc) */

/*
 * Set of descriptors of pipes connected to
 * the output channels of children
 */
static struct pollfd *fds = NULL;
static Job **jobByFdIndex = NULL;
static nfds_t fdsLen = 0;
static void watchfd(Job *);
static void clearfd(Job *);

static char *targPrefix = NULL; /* To identify a job change in the output. */

static Job tokenPoolJob;        /* token wait pseudo-job */

static Job childExitJob;        /* child exit pseudo-job */
#define CEJ_CHILD_EXITED '.'
#define CEJ_RESUME_JOBS 'R'

enum {
        npseudojobs = 2         /* number of pseudo-jobs */
};

static sigset_t caught_signals; /* Set of signals we handle */
static volatile sig_atomic_t caught_sigchld;

static void CollectOutput(Job *, bool);
static void JobInterrupt(bool, int) MAKE_ATTR_DEAD;
static void JobSigReset(void);

static void
SwitchOutputTo(GNode *gn)
{
        /* The node for which output was most recently produced. */
        static GNode *lastNode = NULL;

        if (gn == lastNode)
                return;
        lastNode = gn;

        if (opts.maxJobs != 1 && targPrefix != NULL && targPrefix[0] != '\0')
                (void)fprintf(stdout, "%s %s ---\n", targPrefix, gn->name);
}

static unsigned
nfds_per_job(void)
{
#if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
        if (useMeta)
                return 2;
#endif
        return 1;
}

void
Job_FlagsToString(const Job *job, char *buf, size_t bufsize)
{
        snprintf(buf, bufsize, "%c%c%c",
            job->ignerr ? 'i' : '-',
            !job->echo ? 's' : '-',
            job->special ? 'S' : '-');
}

#ifdef USE_META
struct BuildMon *
Job_BuildMon(Job *job)
{
        return &job->bm;
}
#endif

GNode *
Job_Node(Job *job)
{
        return job->node;
}

int
Job_Pid(Job *job)
{
        return job->pid;
}

static void
JobTable_Dump(const char *where)
{
        const Job *job;
        char flags[4];

        debug_printf("%s, job table:\n", where);
        for (job = job_table; job < job_table_end; job++) {
                Job_FlagsToString(job, flags, sizeof flags);
                debug_printf("job %d, status %s, flags %s, pid %d\n",
                    (int)(job - job_table), JobStatus_Name[job->status],
                    flags, job->pid);
        }
}

/*
 * Delete the target of a failed, interrupted, or otherwise
 * unsuccessful job unless inhibited by .PRECIOUS.
 */
static void
JobDeleteTarget(GNode *gn)
{
        const char *file;

        if (gn->type & OP_JOIN)
                return;
        if (gn->type & OP_PHONY)
                return;
        if (GNode_IsPrecious(gn))
                return;
        if (opts.noExecute)
                return;

        file = GNode_Path(gn);
        if (unlink_file(file) == 0)
                Error("*** %s removed", file);
}

/* Lock the jobs table and the jobs therein. */
static void
JobsTable_Lock(sigset_t *omaskp)
{
        if (sigprocmask(SIG_BLOCK, &caught_signals, omaskp) != 0)
                Punt("JobsTable_Lock: %s", strerror(errno));
}

/* Unlock the jobs table and the jobs therein. */
static void
JobsTable_Unlock(sigset_t *omaskp)
{
        (void)sigprocmask(SIG_SETMASK, omaskp, NULL);
}

static void
SetNonblocking(int fd)
{
        int flags = fcntl(fd, F_GETFL, 0);
        if (flags == -1)
                Punt("SetNonblocking.get: %s", strerror(errno));
        flags |= O_NONBLOCK;
        if (fcntl(fd, F_SETFL, flags) == -1)
                Punt("SetNonblocking.set: %s", strerror(errno));
}

static void
SetCloseOnExec(int fd)
{
        if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
                Punt("SetCloseOnExec: %s", strerror(errno));
}

static void
JobCreatePipe(Job *job, int minfd)
{
        int i;
        int pipe_fds[2];

        if (pipe(pipe_fds) == -1)
                Punt("JobCreatePipe: %s", strerror(errno));

        for (i = 0; i < 2; i++) {
                /* Avoid using low-numbered fds */
                int fd = fcntl(pipe_fds[i], F_DUPFD, minfd);
                if (fd != -1) {
                        close(pipe_fds[i]);
                        pipe_fds[i] = fd;
                }
        }

        job->inPipe = pipe_fds[0];
        job->outPipe = pipe_fds[1];

        SetCloseOnExec(job->inPipe);
        SetCloseOnExec(job->outPipe);

        /*
         * We mark the input side of the pipe non-blocking; we poll(2) the
         * pipe when we're waiting for a job token, but we might lose the
         * race for the token when a new one becomes available, so the read
         * from the pipe should not block.
         */
        SetNonblocking(job->inPipe);
}

/* Pass the signal to each running job. */
static void
JobCondPassSig(int signo)
{
        Job *job;

        DEBUG1(JOB, "JobCondPassSig: signal %d\n", signo);

        for (job = job_table; job < job_table_end; job++) {
                if (job->status != JOB_ST_RUNNING)
                        continue;
                DEBUG2(JOB, "JobCondPassSig passing signal %d to pid %d\n",
                    signo, job->pid);
                KILLPG(job->pid, signo);
        }
}

static void
WriteOrDie(int fd, char ch)
{
        if (write(fd, &ch, 1) != 1)
                execDie("write", "child");
}

static void
HandleSIGCHLD(int signo MAKE_ATTR_UNUSED)
{
        caught_sigchld = 1;
        /* Wake up from poll(). */
        WriteOrDie(childExitJob.outPipe, CEJ_CHILD_EXITED);
}

static void
HandleSIGCONT(int signo MAKE_ATTR_UNUSED)
{
        WriteOrDie(childExitJob.outPipe, CEJ_RESUME_JOBS);
}

/*
 * Pass a signal on to all jobs, then resend to ourselves.
 * We die by the same signal.
 */
MAKE_ATTR_DEAD static void
JobPassSig_int(int signo)
{
        /* Run .INTERRUPT target then exit */
        JobInterrupt(true, signo);
}

/*
 * Pass a signal on to all jobs, then resend to ourselves.
 * We die by the same signal.
 */
MAKE_ATTR_DEAD static void
JobPassSig_term(int signo)
{
        /* Dont run .INTERRUPT target then exit */
        JobInterrupt(false, signo);
}

static void
JobPassSig_suspend(int signo)
{
        sigset_t nmask, omask;
        struct sigaction act;

        /* Suppress job started/continued messages */
        make_suspended = true;

        /* Pass the signal onto every job */
        JobCondPassSig(signo);

        /*
         * 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.
         */
        sigfillset(&nmask);
        sigdelset(&nmask, signo);
        (void)sigprocmask(SIG_SETMASK, &nmask, &omask);

        act.sa_handler = SIG_DFL;
        sigemptyset(&act.sa_mask);
        act.sa_flags = 0;
        (void)sigaction(signo, &act, NULL);

        DEBUG1(JOB, "JobPassSig_suspend passing signal %d to self\n", signo);

        (void)kill(getpid(), signo);

        /*
         * We've been continued.
         *
         * A whole host of signals is going to happen!
         * SIGCHLD for any processes that actually suspended themselves.
         * SIGCHLD for any processes that exited while we were asleep.
         * The SIGCONT that actually caused us to wake up.
         *
         * Since we defer passing the SIGCONT on to our children until
         * the main processing loop, we can be sure that all the SIGCHLD
         * events will have happened by then - and that the waitpid() will
         * collect the child 'suspended' events.
         * For correct sequencing we just need to ensure we process the
         * waitpid() before passing on the SIGCONT.
         *
         * In any case nothing else is needed here.
         */

        /* Restore handler and signal mask */
        act.sa_handler = JobPassSig_suspend;
        (void)sigaction(signo, &act, NULL);
        (void)sigprocmask(SIG_SETMASK, &omask, NULL);
}

static Job *
JobFindPid(int pid, enum JobStatus status, bool isJobs)
{
        Job *job;

        for (job = job_table; job < job_table_end; job++) {
                if (job->status == status && job->pid == pid)
                        return job;
        }
        if (DEBUG(JOB) && isJobs)
                JobTable_Dump("no pid");
        return NULL;
}

/* Parse leading '@', '-' and '+', which control the exact execution mode. */
static void
ParseCommandFlags(char **pp, CommandFlags *out_cmdFlags)
{
        char *p = *pp;
        out_cmdFlags->echo = true;
        out_cmdFlags->ignerr = false;
        out_cmdFlags->always = false;

        for (;;) {
                if (*p == '@')
                        out_cmdFlags->echo = DEBUG(LOUD);
                else if (*p == '-')
                        out_cmdFlags->ignerr = true;
                else if (*p == '+')
                        out_cmdFlags->always = true;
                else if (!ch_isspace(*p))
                        /* Ignore whitespace for compatibility with GNU make */
                        break;
                p++;
        }

        *pp = p;
}

/* Escape a string for a double-quoted string literal in sh, csh and ksh. */
static char *
EscapeShellDblQuot(const char *cmd)
{
        size_t i, j;

        /* Worst that could happen is every char needs escaping. */
        char *esc = bmake_malloc(strlen(cmd) * 2 + 1);
        for (i = 0, j = 0; cmd[i] != '\0'; i++, j++) {
                if (cmd[i] == '$' || cmd[i] == '`' || cmd[i] == '\\' ||
                    cmd[i] == '"')
                        esc[j++] = '\\';
                esc[j] = cmd[i];
        }
        esc[j] = '\0';

        return esc;
}

static void
ShellWriter_WriteFmt(ShellWriter *wr, const char *fmt, const char *arg)
{
        DEBUG1(JOB, fmt, arg);

        (void)fprintf(wr->f, fmt, arg);
        if (wr->f == stdout)
                (void)fflush(wr->f);
}

static void
ShellWriter_WriteLine(ShellWriter *wr, const char *line)
{
        ShellWriter_WriteFmt(wr, "%s\n", line);
}

static void
ShellWriter_EchoOff(ShellWriter *wr)
{
        if (shell->hasEchoCtl)
                ShellWriter_WriteLine(wr, shell->echoOff);
}

static void
ShellWriter_EchoCmd(ShellWriter *wr, const char *escCmd)
{
        ShellWriter_WriteFmt(wr, shell->echoTmpl, escCmd);
}

static void
ShellWriter_EchoOn(ShellWriter *wr)
{
        if (shell->hasEchoCtl)
                ShellWriter_WriteLine(wr, shell->echoOn);
}

static void
ShellWriter_TraceOn(ShellWriter *wr)
{
        if (!wr->xtraced) {
                ShellWriter_WriteLine(wr, "set -x");
                wr->xtraced = true;
        }
}

static void
ShellWriter_ErrOff(ShellWriter *wr, bool echo)
{
        if (echo)
                ShellWriter_EchoOff(wr);
        ShellWriter_WriteLine(wr, shell->errOff);
        if (echo)
                ShellWriter_EchoOn(wr);
}

static void
ShellWriter_ErrOn(ShellWriter *wr, bool echo)
{
        if (echo)
                ShellWriter_EchoOff(wr);
        ShellWriter_WriteLine(wr, shell->errOn);
        if (echo)
                ShellWriter_EchoOn(wr);
}

/*
 * The shell has no built-in error control, so emulate error control by
 * enclosing each shell command in a template like "{ %s \n } || exit $?"
 * (configurable per shell).
 */
static void
JobWriteSpecialsEchoCtl(Job *job, ShellWriter *wr, CommandFlags *inout_cmdFlags,
                        const char *escCmd, const char **inout_cmdTemplate)
{
        /* XXX: Why is the whole job modified at this point? */
        job->ignerr = true;

        if (job->echo && inout_cmdFlags->echo) {
                ShellWriter_EchoOff(wr);
                ShellWriter_EchoCmd(wr, escCmd);

                /*
                 * Leave echoing off so the user doesn't see the commands
                 * for toggling the error checking.
                 */
                inout_cmdFlags->echo = false;
        }
        *inout_cmdTemplate = shell->runIgnTmpl;

        /*
         * The template runIgnTmpl already takes care of ignoring errors,
         * so pretend error checking is still on.
         * XXX: What effects does this have, and why is it necessary?
         */
        inout_cmdFlags->ignerr = false;
}

static void
JobWriteSpecials(Job *job, ShellWriter *wr, const char *escCmd, bool run,
                 CommandFlags *inout_cmdFlags, const char **inout_cmdTemplate)
{
        if (!run)
                inout_cmdFlags->ignerr = false;
        else if (shell->hasErrCtl)
                ShellWriter_ErrOff(wr, job->echo && inout_cmdFlags->echo);
        else if (shell->runIgnTmpl != NULL && shell->runIgnTmpl[0] != '\0') {
                JobWriteSpecialsEchoCtl(job, wr, inout_cmdFlags, escCmd,
                    inout_cmdTemplate);
        } else
                inout_cmdFlags->ignerr = false;
}

static bool
find_make(const char *cmd, const char *make, size_t len)
{
        const char *p;

        for (p = strstr(cmd, make); p != NULL; p = strstr(&p[1], make)) {
                if (p == cmd || ch_isspace(p[-1])) {
                        if (p[len] == '\0' || ch_isspace(p[len])) {
                                DEBUG4(JOB, "find_make: matched \"%.*s\" in \"%.*s...\"\n",
                                    (int)len, p,
                                    (int)len + 32, cmd);

                                return true;
                        }
                }
        }
        return false;
}

/*
 * See if the command possibly calls a sub-make by checking
 * for expansion of ${.MAKE} and possibly ${.MAKE:T}.
 */
bool
MaybeSubMake(const char *cmd)
{
        static char *make, *make_name;
        static size_t make_len, make_name_len;

        if (make == NULL) {
                make = Var_Subst("${.MAKE}", SCOPE_GLOBAL, VARE_EVAL);
                make_len = strlen(make);
                make_name = strrchr(make, '/');
                if (make_name != NULL) {
                        make_name++;
                        make_name_len = strlen(make_name);
                } else
                        make_name_len = 0;
                DEBUG1(JOB, "MaybeSubMake: Looking for \"%s\"\n", make);
        }
        cmd += strspn(cmd, "@ \t+-");
        if (find_make(cmd, make, make_len))
                return true;
        if (make_name_len > 0 && find_make(cmd, make_name, make_name_len))
                return true;
        return false;
}

/*
 * Write a shell command to the job's commands file, to be run later.
 *
 * If the command starts with '@' and neither the -s nor the -n flag was
 * given to make, stick a shell-specific echoOff command in the script.
 *
 * If the command starts with '-' and the shell has no error control (none
 * of the predefined shells has that), ignore errors for the rest of the job.
 *
 * XXX: Why ignore errors for the entire job?  This is documented in the
 * manual page, but without giving a rationale.
 *
 * If the command is just "...", attach all further commands of this job to
 * the .END node instead, see Job_Finish.
 */
static void
JobWriteCommand(Job *job, ShellWriter *wr, StringListNode *ln, const char *ucmd)
{
        bool run;

        CommandFlags cmdFlags;
        /* Template for writing a command to the shell file */
        const char *cmdTemplate;
        char *xcmd;             /* The expanded command */
        char *xcmdStart;
        char *escCmd;           /* xcmd escaped to be used in double quotes */

        run = GNode_ShouldExecute(job->node);

        xcmd = Var_SubstInTarget(ucmd, job->node);
        /* TODO: handle errors */
        xcmdStart = xcmd;

        if (job->node->flags.doneSubmake == false
            && (job->node->type & (OP_MAKE | OP_SUBMAKE)) == 0) {
                if (MaybeSubMake(xcmd))
                        job->node->type |= OP_SUBMAKE;
        }

        cmdTemplate = "%s\n";

        ParseCommandFlags(&xcmd, &cmdFlags);

        /* The '+' command flag overrides the -n or -N options. */
        if (cmdFlags.always && !run) {
                /*
                 * We're not actually executing anything...
                 * but this one needs to be - use compat mode just for it.
                 */
                (void)Compat_RunCommand(ucmd, job->node, ln);
                free(xcmdStart);
                return;
        }

        /*
         * If the shell doesn't have error control, the alternate echoing
         * will be done (to avoid showing additional error checking code)
         * and this needs some characters escaped.
         */
        escCmd = shell->hasErrCtl ? NULL : EscapeShellDblQuot(xcmd);

        if (!cmdFlags.echo) {
                if (job->echo && run && shell->hasEchoCtl)
                        ShellWriter_EchoOff(wr);
                else if (shell->hasErrCtl)
                        cmdFlags.echo = true;
        }

        if (cmdFlags.ignerr) {
                JobWriteSpecials(job, wr, escCmd, run, &cmdFlags, &cmdTemplate);
        } else {

                /*
                 * If errors are being checked and the shell doesn't have
                 * error control but does supply an runChkTmpl template, then
                 * set up commands to run through it.
                 */

                if (!shell->hasErrCtl && shell->runChkTmpl != NULL &&
                    shell->runChkTmpl[0] != '\0') {
                        if (job->echo && cmdFlags.echo) {
                                ShellWriter_EchoOff(wr);
                                ShellWriter_EchoCmd(wr, escCmd);
                                cmdFlags.echo = false;
                        }
                        /*
                         * If it's a comment line or blank, avoid the possible
                         * syntax error generated by "{\n} || exit $?".
                         */
                        cmdTemplate = escCmd[0] == shell->commentChar ||
                                      escCmd[0] == '\0'
                            ? shell->runIgnTmpl
                            : shell->runChkTmpl;
                        cmdFlags.ignerr = false;
                }
        }

        if (DEBUG(SHELL) && strcmp(shellName, "sh") == 0)
                ShellWriter_TraceOn(wr);

        ShellWriter_WriteFmt(wr, cmdTemplate, xcmd);
        free(xcmdStart);
        free(escCmd);

        if (cmdFlags.ignerr)
                ShellWriter_ErrOn(wr, cmdFlags.echo && job->echo);

        if (!cmdFlags.echo)
                ShellWriter_EchoOn(wr);
}

/*
 * Write all commands to the shell file that is later executed.
 *
 * The special command "..." stops writing and saves the remaining commands
 * to be executed later, when the target '.END' is made.
 *
 * Return whether at least one command was written to the shell file.
 */
static bool
JobWriteCommands(Job *job)
{
        StringListNode *ln;
        bool seen = false;
        ShellWriter wr;

        wr.f = job->cmdFILE;
        wr.xtraced = false;

        for (ln = job->node->commands.first; ln != NULL; ln = ln->next) {
                const char *cmd = ln->datum;

                if (strcmp(cmd, "...") == 0) {
                        job->node->type |= OP_SAVE_CMDS;
                        job->tailCmds = ln->next;
                        break;
                }

                JobWriteCommand(job, &wr, ln, ln->datum);
                seen = true;
        }
        job->node->flags.doneSubmake = true;

        return seen;
}

/*
 * Save the delayed commands (those after '...'), to be executed later in
 * the '.END' node, when everything else is done.
 */
static void
JobSaveCommands(Job *job)
{
        StringListNode *ln;

        for (ln = job->tailCmds; ln != NULL; ln = ln->next) {
                const char *cmd = ln->datum;
                char *expanded_cmd;
                /*
                 * XXX: This Var_Subst is only intended to expand the dynamic
                 * variables such as .TARGET, .IMPSRC.  It is not intended to
                 * expand the other variables as well; see deptgt-end.mk.
                 */
                expanded_cmd = Var_SubstInTarget(cmd, job->node);
                /* TODO: handle errors */
                Lst_Append(&Targ_GetEndNode()->commands, expanded_cmd);
                Parse_RegisterCommand(expanded_cmd);
        }
}


/* Close both input and output pipes when a job is finished. */
static void
JobClosePipes(Job *job)
{
        clearfd(job);
        (void)close(job->outPipe);
        job->outPipe = -1;

        CollectOutput(job, true);
        (void)close(job->inPipe);
        job->inPipe = -1;
}

static void
DebugFailedJob(const Job *job)
{
        const StringListNode *ln;

        if (!DEBUG(ERROR))
                return;

        debug_printf("\n");
        debug_printf("*** Failed target: %s\n", job->node->name);
        debug_printf("*** In directory: %s\n", curdir);
        debug_printf("*** Failed commands:\n");
        for (ln = job->node->commands.first; ln != NULL; ln = ln->next) {
                const char *cmd = ln->datum;
                debug_printf("\t%s\n", cmd);

                if (strchr(cmd, '$') != NULL) {
                        char *xcmd = Var_Subst(cmd, job->node, VARE_EVAL);
                        debug_printf("\t=> %s\n", xcmd);
                        free(xcmd);
                }
        }
}

static void
JobFinishDoneExitedError(Job *job, int *inout_status)
{
        SwitchOutputTo(job->node);
#ifdef USE_META
        if (useMeta) {
                meta_job_error(job, job->node,
                    job->ignerr, WEXITSTATUS(*inout_status));
        }
#endif
        if (!shouldDieQuietly(job->node, -1)) {
                DebugFailedJob(job);
                (void)printf("*** [%s] Error code %d%s\n",
                    job->node->name, WEXITSTATUS(*inout_status),
                    job->ignerr ? " (ignored)" : "");
        }

        if (job->ignerr)
                *inout_status = 0;
        else {
                if (deleteOnError)
                        JobDeleteTarget(job->node);
                PrintOnError(job->node, "\n");
        }
}

static void
JobFinishDoneExited(Job *job, int *inout_status)
{
        DEBUG2(JOB, "Target %s, pid %d exited\n",
            job->node->name, job->pid);

        if (WEXITSTATUS(*inout_status) != 0)
                JobFinishDoneExitedError(job, inout_status);
        else if (DEBUG(JOB)) {
                SwitchOutputTo(job->node);
                (void)printf("Target %s, pid %d exited successfully\n",
                    job->node->name, job->pid);
        }
}

static void
JobFinishDoneSignaled(Job *job, int status)
{
        SwitchOutputTo(job->node);
        DebugFailedJob(job);
        (void)printf("*** [%s] Signal %d\n", job->node->name, WTERMSIG(status));
        if (deleteOnError)
                JobDeleteTarget(job->node);
}

static void
JobFinishDone(Job *job, int *inout_status)
{
        if (WIFEXITED(*inout_status))
                JobFinishDoneExited(job, inout_status);
        else
                JobFinishDoneSignaled(job, *inout_status);

        (void)fflush(stdout);
}

/*
 * Finish the job, add deferred commands to the .END node, mark the job as
 * free, update parent nodes and start new jobs as available/necessary.
 */
static void
JobFinish(Job *job, int status)
{
        bool done, return_job_token;

        DEBUG3(JOB, "JobFinish: target %s, pid %d, status %#x\n",
            job->node->name, job->pid, status);

        if ((WIFEXITED(status) && WEXITSTATUS(status) != 0 && !job->ignerr) ||
            WIFSIGNALED(status)) {
                /* Finished because of an error. */

                JobClosePipes(job);
                if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
                        if (fclose(job->cmdFILE) != 0)
                                Punt("Cannot write shell script for \"%s\": %s",
                                    job->node->name, strerror(errno));
                        job->cmdFILE = NULL;
                }
                done = true;

        } 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 to run
                 * the next command.
                 */
                done = WEXITSTATUS(status) != 0;

                JobClosePipes(job);

        } else {
                /* No need to close things down or anything. */
                done = false;
        }

        if (done)
                JobFinishDone(job, &status);

#ifdef USE_META
        if (useMeta) {
                int meta_status = meta_job_finish(job);
                if (meta_status != 0 && status == 0)
                        status = meta_status;
        }
#endif

        return_job_token = false;

        Trace_Log(JOBEND, job);
        if (!job->special) {
                if (status != 0 ||
                    aborting == ABORT_ERROR || aborting == ABORT_INTERRUPT)
                        return_job_token = true;
        }

        if (aborting != ABORT_ERROR && aborting != ABORT_INTERRUPT &&
            status == 0) {
                JobSaveCommands(job);
                job->node->made = MADE;
                if (!job->special)
                        return_job_token = true;
                Make_Update(job->node);
                job->status = JOB_ST_FREE;
        } else if (status != 0) {
                job_errors++;
                job->status = JOB_ST_FREE;
        }

        if (job_errors > 0 && !opts.keepgoing && aborting != ABORT_INTERRUPT) {
                /* Prevent more jobs from getting started. */
                aborting = ABORT_ERROR;
        }

        if (return_job_token)
                TokenPool_Return();

        if (aborting == ABORT_ERROR && jobTokensRunning == 0) {
                if (shouldDieQuietly(NULL, -1))
                        exit(2);
                Fatal("%d error%s", job_errors, job_errors == 1 ? "" : "s");
        }
}

static void
TouchRegular(GNode *gn)
{
        const char *file = GNode_Path(gn);
        struct utimbuf times;
        int fd;
        char c;

        times.actime = now;
        times.modtime = now;
        if (utime(file, &times) >= 0)
                return;

        fd = open(file, O_RDWR | O_CREAT, 0666);
        if (fd < 0) {
                (void)fprintf(stderr, "*** couldn't touch %s: %s\n",
                    file, strerror(errno));
                (void)fflush(stderr);
                return;         /* XXX: What about propagating the error? */
        }

        /*
         * Last resort: update the file's time stamps in the traditional way.
         * XXX: This doesn't work for empty files, which are sometimes used
         * as marker files.
         */
        if (read(fd, &c, 1) == 1) {
                (void)lseek(fd, 0, SEEK_SET);
                while (write(fd, &c, 1) == -1 && errno == EAGAIN)
                        continue;
        }
        (void)close(fd);        /* XXX: What about propagating the error? */
}

/*
 * Touch the given target. Called by Job_Make when the -t flag was given.
 *
 * The modification date of the file is changed.
 * If the file did not exist, it is created.
 */
void
Job_Touch(GNode *gn, bool echo)
{
        if (gn->type &
            (OP_JOIN | OP_USE | OP_USEBEFORE | OP_EXEC | OP_OPTIONAL |
             OP_SPECIAL | OP_PHONY)) {
                /*
                 * These are "virtual" targets and should not really be
                 * created.
                 */
                return;
        }

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

        if (!GNode_ShouldExecute(gn))
                return;

        if (gn->type & OP_ARCHV)
                Arch_Touch(gn);
        else if (gn->type & OP_LIB)
                Arch_TouchLib(gn);
        else
                TouchRegular(gn);
}

/*
 * Make sure the given node has all the commands it needs.
 *
 * The node will have commands from the .DEFAULT rule added to it if it
 * needs them.
 *
 * Input:
 *      gn              The target whose commands need verifying
 *      abortProc       Function to abort with message
 *
 * Results:
 *      true if the commands are ok.
 */
bool
Job_CheckCommands(GNode *gn, void (*abortProc)(const char *, ...))
{
        if (GNode_IsTarget(gn))
                return true;
        if (!Lst_IsEmpty(&gn->commands))
                return true;
        if ((gn->type & OP_LIB) && !Lst_IsEmpty(&gn->children))
                return true;

        /*
         * No commands. Look for .DEFAULT rule from which we might infer
         * commands.
         */
        if (defaultNode != NULL && !Lst_IsEmpty(&defaultNode->commands) &&
            !(gn->type & OP_SPECIAL)) {
                /*
                 * The traditional Make only looks for a .DEFAULT if the node
                 * was never the target of an operator, so that's what we do
                 * too.
                 *
                 * The .DEFAULT node acts like a transformation rule, in that
                 * gn also inherits any attributes or sources attached to
                 * .DEFAULT itself.
                 */
                Make_HandleUse(defaultNode, gn);
                Var_Set(gn, IMPSRC, GNode_VarTarget(gn));
                return true;
        }

        Dir_UpdateMTime(gn, false);
        if (gn->mtime != 0 || (gn->type & OP_SPECIAL))
                return true;

        /*
         * 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.
         */

        if (gn->flags.fromDepend) {
                if (!Job_RunTarget(".STALE", gn->fname))
                        fprintf(stdout,
                            "%s: %s:%u: ignoring stale %s for %s\n",
                            progname, gn->fname, gn->lineno, makeDependfile,
                            gn->name);
                return true;
        }

        if (gn->type & OP_OPTIONAL) {
                (void)fprintf(stdout, "%s: don't know how to make %s (%s)\n",
                    progname, gn->name, "ignored");
                (void)fflush(stdout);
                return true;
        }

        if (opts.keepgoing) {
                (void)fprintf(stdout, "%s: don't know how to make %s (%s)\n",
                    progname, gn->name, "continuing");
                (void)fflush(stdout);
                return false;
        }

        abortProc("don't know how to make %s. Stop", gn->name);
        return false;
}

/*
 * Execute the shell for the given job.
 *
 * See Job_CatchOutput for handling the output of the shell.
 */
static void
JobExec(Job *job, char **argv)
{
        int cpid;               /* ID of new child */
        sigset_t mask;

        if (DEBUG(JOB)) {
                int i;

                debug_printf("Running %s\n", job->node->name);
                debug_printf("\tCommand:");
                for (i = 0; argv[i] != NULL; i++) {
                        debug_printf(" %s", argv[i]);
                }
                debug_printf("\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 (job->echo)
                SwitchOutputTo(job->node);

        /* No interruptions until this job is in the jobs table. */
        JobsTable_Lock(&mask);

        /* Pre-emptively mark job running, pid still zero though */
        job->status = JOB_ST_RUNNING;

        Var_ReexportVars(job->node);
        Var_ExportStackTrace(job->node->name, NULL);

        cpid = FORK_FUNCTION();
        if (cpid == -1)
                Punt("fork: %s", strerror(errno));

        if (cpid == 0) {
                /* Child */
                sigset_t tmask;

#ifdef USE_META
                if (useMeta)
                        meta_job_child(job);
#endif
                /*
                 * Reset all signal handlers; this is necessary because we
                 * also need to unblock signals before we exec(2).
                 */
                JobSigReset();

                sigemptyset(&tmask);
                JobsTable_Unlock(&tmask);

                if (dup2(fileno(job->cmdFILE), STDIN_FILENO) == -1)
                        execDie("dup2", "job->cmdFILE");
                if (fcntl(STDIN_FILENO, F_SETFD, 0) == -1)
                        execDie("clear close-on-exec", "stdin");
                if (lseek(STDIN_FILENO, 0, SEEK_SET) == -1)
                        execDie("lseek to 0", "stdin");

                if (job->node->type & (OP_MAKE | OP_SUBMAKE)) {
                        /* Pass job token pipe to submakes. */
                        if (fcntl(tokenPoolJob.inPipe, F_SETFD, 0) == -1)
                                execDie("clear close-on-exec",
                                    "tokenPoolJob.inPipe");
                        if (fcntl(tokenPoolJob.outPipe, F_SETFD, 0) == -1)
                                execDie("clear close-on-exec",
                                    "tokenPoolJob.outPipe");
                }

                if (dup2(job->outPipe, STDOUT_FILENO) == -1)
                        execDie("dup2", "job->outPipe");

                /*
                 * The output channels are marked close on exec. This bit
                 * was duplicated by 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.
                 */
                if (fcntl(STDOUT_FILENO, F_SETFD, 0) == -1)
                        execDie("clear close-on-exec", "stdout");
                if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
                        execDie("dup2", "1, 2");

                /*
                 * 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(MAKE_NATIVE) || defined(HAVE_SETPGID)
# if defined(SYSV)
                /* XXX: dsl - I'm sure this should be setpgrp()... */
                (void)setsid();
# else
                (void)setpgid(0, getpid());
# endif
#endif

                (void)execv(shellPath, argv);
                execDie("exec", shellPath);
        }

        /* Parent, continuing after the child exec */
        job->pid = cpid;

        Trace_Log(JOBSTART, job);

#ifdef USE_META
        if (useMeta)
                meta_job_parent(job, cpid);
#endif

        job->outBufLen = 0;

        watchfd(job);

        if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
                if (fclose(job->cmdFILE) != 0)
                        Punt("Cannot write shell script for \"%s\": %s",
                            job->node->name, strerror(errno));
                job->cmdFILE = NULL;
        }

        if (DEBUG(JOB)) {
                debug_printf(
                    "JobExec: target %s, pid %d added to jobs table\n",
                    job->node->name, job->pid);
                JobTable_Dump("job started");
        }
        JobsTable_Unlock(&mask);
}

static void
BuildArgv(Job *job, char **argv)
{
        int argc;
        static char args[10];

        argv[0] = UNCONST(shellName);
        argc = 1;

        if ((shell->errFlag != NULL && shell->errFlag[0] != '-') ||
            (shell->echoFlag != NULL && shell->echoFlag[0] != '-')) {
                /*
                 * 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.
                 *
                 * TODO: Research until when the above comments were
                 * practically relevant.
                 */
                (void)snprintf(args, sizeof args, "-%s%s",
                    !job->ignerr && shell->errFlag != NULL
                        ? shell->errFlag : "",
                    job->echo && shell->echoFlag != NULL
                        ? shell->echoFlag : "");
                if (args[1] != '\0') {
                        argv[argc] = args;
                        argc++;
                }
        } else {
                if (!job->ignerr && shell->errFlag != NULL) {
                        argv[argc] = UNCONST(shell->errFlag);
                        argc++;
                }
                if (job->echo && shell->echoFlag != NULL) {
                        argv[argc] = UNCONST(shell->echoFlag);
                        argc++;
                }
        }
        argv[argc] = NULL;
}

static void
JobWriteShellCommands(Job *job, GNode *gn, bool *out_run)
{
        char fname[MAXPATHLEN];
        int fd;

        fd = Job_TempFile(NULL, fname, sizeof fname);

        job->cmdFILE = fdopen(fd, "w+");
        if (job->cmdFILE == NULL)
                Punt("Could not fdopen %s", fname);

        (void)fcntl(fd, F_SETFD, FD_CLOEXEC);

#ifdef USE_META
        if (useMeta) {
                meta_job_start(job, gn);
                if (gn->type & OP_SILENT)       /* might have changed */
                        job->echo = false;
        }
#endif

        *out_run = JobWriteCommands(job);
}

void
Job_Make(GNode *gn)
{
        Job *job;
        char *argv[10];
        bool cmdsOK;            /* true if the nodes commands were all right */
        bool run;

        for (job = job_table; job < job_table_end; job++) {
                if (job->status == JOB_ST_FREE)
                        break;
        }
        if (job >= job_table_end)
                Punt("Job_Make no job slots vacant");

        memset(job, 0, sizeof *job);
        job->node = gn;
        job->tailCmds = NULL;
        job->status = JOB_ST_SET_UP;

        job->special = (gn->type & OP_SPECIAL) != OP_NONE;
        job->ignerr = opts.ignoreErrors || gn->type & OP_IGNORE;
        job->echo = !(opts.silent || gn->type & OP_SILENT);

        /*
         * Check the commands now so any attributes from .DEFAULT have a
         * chance to migrate to the node.
         */
        cmdsOK = Job_CheckCommands(gn, Error);

        job->inPollfd = NULL;

        if (Lst_IsEmpty(&gn->commands)) {
                job->cmdFILE = stdout;
                run = false;

                if (!cmdsOK) {
                        PrintOnError(gn, "\n");
                        DieHorribly();
                }
        } else if (((gn->type & OP_MAKE) && !opts.noRecursiveExecute) ||
            (!opts.noExecute && !opts.touch)) {
                int parseErrorsBefore;

                if (!cmdsOK) {
                        PrintOnError(gn, "\n");
                        DieHorribly();
                }

                parseErrorsBefore = parseErrors;
                JobWriteShellCommands(job, gn, &run);
                if (parseErrors != parseErrorsBefore)
                        run = false;
                (void)fflush(job->cmdFILE);
        } else if (!GNode_ShouldExecute(gn)) {
                SwitchOutputTo(gn);
                job->cmdFILE = stdout;
                if (cmdsOK)
                        JobWriteCommands(job);
                run = false;
                (void)fflush(job->cmdFILE);
        } else {
                Job_Touch(gn, job->echo);
                run = false;
        }

        if (!run) {
                if (!job->special)
                        TokenPool_Return();

                if (job->cmdFILE != NULL && job->cmdFILE != stdout) {
                        (void)fclose(job->cmdFILE);
                        job->cmdFILE = NULL;
                }

                if (cmdsOK && aborting == ABORT_NONE) {
                        JobSaveCommands(job);
                        job->node->made = MADE;
                        Make_Update(job->node);
                }
                job->status = JOB_ST_FREE;
                return;
        }

        BuildArgv(job, argv);
        JobCreatePipe(job, 3);
        JobExec(job, argv);
}

/*
 * If the shell has an output filter (which only csh and ksh have by default),
 * print the output of the child process, skipping the noPrint text of the
 * shell.
 *
 * Return the part of the output that the calling function needs to output by
 * itself.
 */
static const char *
PrintFilteredOutput(Job *job, size_t len)
{
        const char *p = job->outBuf, *ep, *endp;

        if (shell->noPrint == NULL || shell->noPrint[0] == '\0')
                return p;

        endp = p + len;
        while ((ep = strstr(p, shell->noPrint)) != NULL && ep < endp) {
                if (ep > p) {
                        if (!opts.silent)
                                SwitchOutputTo(job->node);
                        (void)fwrite(p, 1, (size_t)(ep - p), stdout);
                        (void)fflush(stdout);
                }
                p = ep + shell->noPrintLen;
                if (p == endp)
                        break;
                p++;            /* skip over the (XXX: assumed) newline */
                cpp_skip_whitespace(&p);
        }
        return p;
}

/*
 * Collect output from the job. Print any complete lines.
 *
 * In the output of the shell, the 'noPrint' lines are removed. If the
 * command is not alone on the line (the character after it is not \0 or
 * \n), we do print whatever follows it.
 *
 * If finish is true, collect all remaining output for the job.
 */
static void
CollectOutput(Job *job, bool finish)
{
        const char *p;
        size_t nr;              /* number of bytes read */
        size_t i;               /* auxiliary index into outBuf */
        size_t max;             /* limit for i (end of current data) */

again:
        nr = (size_t)read(job->inPipe, job->outBuf + job->outBufLen,
            JOB_BUFSIZE - job->outBufLen);
        if (nr == (size_t)-1) {
                if (errno == EAGAIN)
                        return;
                if (DEBUG(JOB))
                        perror("CollectOutput(piperead)");
                nr = 0;
        }

        if (nr == 0)
                finish = false; /* stop looping */

        if (nr == 0 && job->outBufLen > 0) {
                job->outBuf[job->outBufLen] = '\n';
                nr = 1;
        }

        max = job->outBufLen + nr;
        job->outBuf[max] = '\0';

        for (i = job->outBufLen; i < max; i++)
                if (job->outBuf[i] == '\0')
                        job->outBuf[i] = ' ';

        for (i = max; i > job->outBufLen; i--)
                if (job->outBuf[i - 1] == '\n')
                        break;

        if (i == job->outBufLen) {
                job->outBufLen = max;
                if (max < JOB_BUFSIZE)
                        goto unfinished_line;
                i = max;
        }

        p = PrintFilteredOutput(job, i);
        if (*p != '\0') {
                if (!opts.silent)
                        SwitchOutputTo(job->node);
#ifdef USE_META
                if (useMeta)
                        meta_job_output(job, p, i < max ? i : max);
#endif
                (void)fwrite(p, 1, (size_t)(job->outBuf + i - p), stdout);
                (void)fflush(stdout);
        }
        memmove(job->outBuf, job->outBuf + i, max - i);
        job->outBufLen = max - i;

unfinished_line:
        if (finish)
                goto again;
}

static void
JobRun(GNode *target)
{
        /* Don't let these special jobs overlap with other unrelated jobs. */
        Compat_Make(target, target);
        if (GNode_IsError(target)) {
                PrintOnError(target, "\n\nStop.\n");
                exit(1);
        }
}

void
Job_CatchChildren(void)
{
        int pid;
        int status;

        if (jobTokensRunning == 0)
                return;
        if (caught_sigchld == 0)
                return;
        caught_sigchld = 0;

        while ((pid = waitpid((pid_t)-1, &status, WNOHANG | WUNTRACED)) > 0) {
                DEBUG2(JOB,
                    "Process with pid %d exited/stopped with status %#x.\n",
                    pid, status);
                JobReapChild(pid, status, true);
        }
}

/*
 * It is possible that wait[pid]() was called from elsewhere,
 * this lets us reap jobs regardless.
 */
void
JobReapChild(pid_t pid, int status, bool isJobs)
{
        Job *job;

        if (jobTokensRunning == 0)
                return;

        job = JobFindPid(pid, JOB_ST_RUNNING, isJobs);
        if (job == NULL) {
                if (isJobs && !lurking_children)
                        Error("Child with pid %d and status %#x not in table?",
                            pid, status);
                return;
        }

        if (WIFSTOPPED(status)) {
                DEBUG2(JOB, "Process for target %s, pid %d stopped\n",
                    job->node->name, job->pid);
                if (!make_suspended) {
                        switch (WSTOPSIG(status)) {
                        case SIGTSTP:
                                (void)printf("*** [%s] Suspended\n",
                                    job->node->name);
                                break;
                        case SIGSTOP:
                                (void)printf("*** [%s] Stopped\n",
                                    job->node->name);
                                break;
                        default:
                                (void)printf("*** [%s] Stopped -- signal %d\n",
                                    job->node->name, WSTOPSIG(status));
                        }
                        job->suspended = true;
                }
                (void)fflush(stdout);
                return;
        }

        job->status = JOB_ST_FINISHED;
        job->exit_status = status;
        if (WIFEXITED(status))
                job->node->exit_status = WEXITSTATUS(status);

        JobFinish(job, status);
}

static void
Job_Continue(Job *job)
{
        DEBUG1(JOB, "Continuing pid %d\n", job->pid);
        if (job->suspended) {
                (void)printf("*** [%s] Continued\n", job->node->name);
                (void)fflush(stdout);
                job->suspended = false;
        }
        if (KILLPG(job->pid, SIGCONT) != 0)
                DEBUG1(JOB, "Failed to send SIGCONT to pid %d\n", job->pid);
}

static void
ContinueJobs(void)
{
        Job *job;

        for (job = job_table; job < job_table_end; job++) {
                if (job->status == JOB_ST_RUNNING &&
                    (make_suspended || job->suspended))
                        Job_Continue(job);
                else if (job->status == JOB_ST_FINISHED)
                        JobFinish(job, job->exit_status);
        }
        make_suspended = false;
}

void
Job_CatchOutput(void)
{
        int nready;
        Job *job;
        unsigned i;

        (void)fflush(stdout);

        do {
                /* Maybe skip the job token pipe. */
                nfds_t skip = wantToken ? 0 : 1;
                nready = poll(fds + skip, fdsLen - skip, -1);
        } while (nready < 0 && errno == EINTR);

        if (nready < 0)
                Punt("poll: %s", strerror(errno));

        if (nready > 0 && childExitJob.inPollfd->revents & POLLIN) {
                char token;
                ssize_t count = read(childExitJob.inPipe, &token, 1);
                if (count != 1)
                        Punt("childExitJob.read: %s",
                            count == 0 ? "EOF" : strerror(errno));
                if (token == CEJ_RESUME_JOBS)
                        ContinueJobs();
                nready--;
        }

        Job_CatchChildren();
        if (nready == 0)
                return;

        for (i = npseudojobs * nfds_per_job(); i < fdsLen; i++) {
                if (fds[i].revents == 0)
                        continue;
                job = jobByFdIndex[i];
                if (job->status == JOB_ST_RUNNING)
                        CollectOutput(job, false);
#if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
                /*
                 * With meta mode, we may have activity on the job's filemon
                 * descriptor too, which at the moment is any pollfd other
                 * than job->inPollfd.
                 */
                if (useMeta && job->inPollfd != &fds[i]) {
                        if (meta_job_event(job) <= 0)
                                fds[i].events = 0;      /* never mind */
                }
#endif
                if (--nready == 0)
                        return;
        }
}

static void
InitShellNameAndPath(void)
{
        shellName = shell->name;

#ifdef DEFSHELL_CUSTOM
        if (shellName[0] == '/') {
                shellPath = bmake_strdup(shellName);
                shellName = str_basename(shellPath);
                return;
        }
#endif

        shellPath = str_concat3(_PATH_DEFSHELLDIR, "/", shellName);
}

void
Shell_Init(void)
{
        if (shellPath == NULL)
                InitShellNameAndPath();

        Var_SetWithFlags(SCOPE_CMDLINE, ".SHELL", shellPath,
                         VAR_SET_INTERNAL|VAR_SET_READONLY);
        if (shell->errFlag == NULL)
                shell->errFlag = "";
        if (shell->echoFlag == NULL)
                shell->echoFlag = "";
        if (shell->hasErrCtl && shell->errFlag[0] != '\0') {
                if (shellErrFlag != NULL &&
                    strcmp(shell->errFlag, &shellErrFlag[1]) != 0) {
                        free(shellErrFlag);
                        shellErrFlag = NULL;
                }
                if (shellErrFlag == NULL)
                        shellErrFlag = str_concat2("-", shell->errFlag);
        } else if (shellErrFlag != NULL) {
                free(shellErrFlag);
                shellErrFlag = NULL;
        }
}

/* Return the shell string literal that results in a newline character. */
const char *
Shell_GetNewline(void)
{
        return shell->newline;
}

void
Job_SetPrefix(void)
{
        if (targPrefix != NULL)
                free(targPrefix);
        else if (!Var_Exists(SCOPE_GLOBAL, ".MAKE.JOB.PREFIX"))
                Global_Set(".MAKE.JOB.PREFIX", "---");

        targPrefix = Var_Subst("${.MAKE.JOB.PREFIX}",
            SCOPE_GLOBAL, VARE_EVAL);
        /* TODO: handle errors */
}

static void
AddSig(int sig, SignalProc handler)
{
        if (bmake_signal(sig, SIG_IGN) != SIG_IGN) {
                sigaddset(&caught_signals, sig);
                (void)bmake_signal(sig, handler);
        }
}

void
Job_Init(void)
{
        Job_SetPrefix();

        job_table = bmake_malloc((size_t)opts.maxJobs * sizeof *job_table);
        memset(job_table, 0, (size_t)opts.maxJobs * sizeof *job_table);
        job_table_end = job_table + opts.maxJobs;
        wantToken = false;
        caught_sigchld = 0;

        aborting = ABORT_NONE;
        job_errors = 0;

        /*
         * There is a non-zero chance that we already have children,
         * e.g. after 'make -f- <<EOF'.
         * Since their termination causes a 'Child (pid) not in table'
         * message, Collect the status of any that are already dead, and
         * suppress the error message if there are any undead ones.
         */
        for (;;) {
                int rval, status;
                rval = waitpid((pid_t)-1, &status, WNOHANG);
                if (rval > 0)
                        continue;
                if (rval == 0)
                        lurking_children = true;
                break;
        }

        Shell_Init();

        JobCreatePipe(&childExitJob, 3);

        {
                size_t nfds = (npseudojobs + (size_t)opts.maxJobs) *
                              nfds_per_job();
                fds = bmake_malloc(sizeof *fds * nfds);
                jobByFdIndex = bmake_malloc(sizeof *jobByFdIndex * nfds);
        }

        /* These are permanent entries and take slots 0 and 1 */
        watchfd(&tokenPoolJob);
        watchfd(&childExitJob);

        sigemptyset(&caught_signals);
        (void)bmake_signal(SIGCHLD, HandleSIGCHLD);
        sigaddset(&caught_signals, SIGCHLD);

        /* Handle the signals specified by POSIX. */
        AddSig(SIGINT, JobPassSig_int);
        AddSig(SIGHUP, JobPassSig_term);
        AddSig(SIGTERM, JobPassSig_term);
        AddSig(SIGQUIT, JobPassSig_term);

        /*
         * These signals need to be passed to the jobs, as each job has its
         * own process group and thus the terminal driver doesn't forward the
         * signals itself.
         */
        AddSig(SIGTSTP, JobPassSig_suspend);
        AddSig(SIGTTOU, JobPassSig_suspend);
        AddSig(SIGTTIN, JobPassSig_suspend);
        AddSig(SIGWINCH, JobCondPassSig);
        AddSig(SIGCONT, HandleSIGCONT);

        (void)Job_RunTarget(".BEGIN", NULL);
        /* Create the .END node, see Targ_GetEndNode in Compat_MakeAll. */
        (void)Targ_GetEndNode();
}

static void
DelSig(int sig)
{
        if (sigismember(&caught_signals, sig) != 0)
                (void)bmake_signal(sig, SIG_DFL);
}

static void
JobSigReset(void)
{
        DelSig(SIGINT);
        DelSig(SIGHUP);
        DelSig(SIGQUIT);
        DelSig(SIGTERM);
        DelSig(SIGTSTP);
        DelSig(SIGTTOU);
        DelSig(SIGTTIN);
        DelSig(SIGWINCH);
        DelSig(SIGCONT);
        (void)bmake_signal(SIGCHLD, SIG_DFL);
}

static Shell *
FindShellByName(const char *name)
{
        Shell *sh = shells;
        const Shell *shellsEnd = sh + sizeof shells / sizeof shells[0];

        for (sh = shells; sh < shellsEnd; sh++) {
                if (strcmp(name, sh->name) == 0)
                        return sh;
        }
        return NULL;
}

/*
 * Parse a shell specification and set up 'shell', shellPath and
 * shellName appropriately.
 *
 * Input:
 *      line            The shell spec
 *
 * Results:
 *      Returns false if the specification was incorrect.
 *      If successful, 'shell' is usable, shellPath is the full path of the
 *      shell described by 'shell', and shellName is the final component of
 *      shellPath.
 *
 * Notes:
 *      A shell specification has the form ".SHELL: keyword=value...". Double
 *      quotes can be used to enclose blanks in words. A backslash escapes
 *      anything (most notably a double-quote and a space) and
 *      provides the usual escape sequences from C. There should be no
 *      unnecessary spaces in the word. The keywords are:
 *          name        Name of shell.
 *          path        Location of shell.
 *          quiet       Command to turn off echoing.
 *          echo        Command to turn echoing on
 *          filter      The output from the shell command that turns off
 *                      echoing, to be filtered from the final output.
 *          echoFlag    Flag to turn echoing on at the start.
 *          errFlag     Flag to turn error checking on at the start.
 *          hasErrCtl   True if the shell has error checking control.
 *          newline     String literal to represent a newline character.
 *          check       If hasErrCtl is true: The command to turn on error
 *                      checking. If hasErrCtl is false: The template for a
 *                      shell command that echoes a command for which error
 *                      checking is off.
 *          ignore      If hasErrCtl is true: The command to turn off error
 *                      checking. If hasErrCtl is false: The template for a
 *                      shell command that executes a command so as to ignore
 *                      any errors it returns.
 */
bool
Job_ParseShell(char *line)
{
        Words wordsList;
        char **words;
        char **argv;
        size_t argc;
        char *path;
        Shell newShell;
        bool fullSpec = false;
        Shell *sh;

        /* XXX: don't use line as an iterator variable */
        pp_skip_whitespace(&line);

        free(shell_freeIt);

        memset(&newShell, 0, sizeof newShell);

        wordsList = Str_Words(line, true);
        words = wordsList.words;
        argc = wordsList.len;
        path = wordsList.freeIt;
        if (words == NULL) {
                Error("Unterminated quoted string [%s]", line);
                return false;
        }
        shell_freeIt = path;

        for (path = NULL, argv = words; argc != 0; argc--, argv++) {
                char *arg = *argv;
                if (strncmp(arg, "path=", 5) == 0) {
                        path = arg + 5;
                } else if (strncmp(arg, "name=", 5) == 0) {
                        newShell.name = arg + 5;
                } else {
                        if (strncmp(arg, "quiet=", 6) == 0) {
                                newShell.echoOff = arg + 6;
                        } else if (strncmp(arg, "echo=", 5) == 0) {
                                newShell.echoOn = arg + 5;
                        } else if (strncmp(arg, "filter=", 7) == 0) {
                                newShell.noPrint = arg + 7;
                                newShell.noPrintLen = strlen(newShell.noPrint);
                        } else if (strncmp(arg, "echoFlag=", 9) == 0) {
                                newShell.echoFlag = arg + 9;
                        } else if (strncmp(arg, "errFlag=", 8) == 0) {
                                newShell.errFlag = arg + 8;
                        } else if (strncmp(arg, "hasErrCtl=", 10) == 0) {
                                char c = arg[10];
                                newShell.hasErrCtl = c == 'Y' || c == 'y' ||
                                                     c == 'T' || c == 't';
                        } else if (strncmp(arg, "newline=", 8) == 0) {
                                newShell.newline = arg + 8;
                        } else if (strncmp(arg, "check=", 6) == 0) {
                                /*
                                 * Before 2020-12-10, these two variables had
                                 * been a single variable.
                                 */
                                newShell.errOn = arg + 6;
                                newShell.echoTmpl = arg + 6;
                        } else if (strncmp(arg, "ignore=", 7) == 0) {
                                /*
                                 * Before 2020-12-10, these two variables had
                                 * been a single variable.
                                 */
                                newShell.errOff = arg + 7;
                                newShell.runIgnTmpl = arg + 7;
                        } else if (strncmp(arg, "errout=", 7) == 0) {
                                newShell.runChkTmpl = arg + 7;
                        } else if (strncmp(arg, "comment=", 8) == 0) {
                                newShell.commentChar = arg[8];
                        } else {
                                Parse_Error(PARSE_FATAL,
                                    "Unknown keyword \"%s\"", arg);
                                free(words);
                                return false;
                        }
                        fullSpec = true;
                }
        }

        if (path == NULL) {
                if (newShell.name == NULL) {
                        Parse_Error(PARSE_FATAL,
                            "Neither path nor name specified");
                        free(words);
                        return false;
                } else {
                        if ((sh = FindShellByName(newShell.name)) == NULL) {
                                Parse_Error(PARSE_WARNING,
                                    "%s: No matching shell", newShell.name);
                                free(words);
                                return false;
                        }
                        shell = sh;
                        shellName = newShell.name;
                        if (shellPath != NULL) {
                                free(shellPath);
                                shellPath = NULL;
                                Shell_Init();
                        }
                }
        } else {
                free(shellPath);
                shellPath = bmake_strdup(path);
                shellName = newShell.name != NULL ? newShell.name
                    : str_basename(path);
                if (!fullSpec) {
                        if ((sh = FindShellByName(shellName)) == NULL) {
                                Parse_Error(PARSE_WARNING,
                                    "%s: No matching shell", shellName);
                                free(words);
                                return false;
                        }
                        shell = sh;
                } else {
                        shell = bmake_malloc(sizeof *shell);
                        *shell = newShell;
                }
                /* This will take care of shellErrFlag. */
                Shell_Init();
        }

        if (shell->echoOn != NULL && shell->echoOff != NULL)
                shell->hasEchoCtl = true;

        if (!shell->hasErrCtl) {
                if (shell->echoTmpl == NULL)
                        shell->echoTmpl = "";
                if (shell->runIgnTmpl == NULL)
                        shell->runIgnTmpl = "%s\n";
        }

        /*
         * Do not free up the words themselves, since they may be in use
         * by the shell specification.
         */
        free(words);
        return true;
}

/*
 * After receiving an interrupt signal, terminate all child processes and if
 * necessary make the .INTERRUPT target.
 */
static void
JobInterrupt(bool runINTERRUPT, int signo)
{
        Job *job;
        sigset_t mask;

        aborting = ABORT_INTERRUPT;

        JobsTable_Lock(&mask);

        for (job = job_table; job < job_table_end; job++) {
                if (job->status == JOB_ST_RUNNING && job->pid != 0) {
                        DEBUG2(JOB,
                            "JobInterrupt passing signal %d to child %d.\n",
                            signo, job->pid);
                        KILLPG(job->pid, signo);
                }
        }

        for (job = job_table; job < job_table_end; job++) {
                if (job->status == JOB_ST_RUNNING && job->pid != 0) {
                        int status;
                        (void)waitpid(job->pid, &status, 0);
                        JobDeleteTarget(job->node);
                }
        }

        JobsTable_Unlock(&mask);

        if (runINTERRUPT && !opts.touch) {
                GNode *dotInterrupt = Targ_FindNode(".INTERRUPT");
                if (dotInterrupt != NULL) {
                        opts.ignoreErrors = false;
                        JobRun(dotInterrupt);
                }
        }
        Trace_Log(MAKEINTR, NULL);
        exit(signo);            /* XXX: why signo? */
}

/* Make the .END target, returning the number of job-related errors. */
int
Job_MakeDotEnd(void)
{
        GNode *dotEnd = Targ_GetEndNode();
        if (!Lst_IsEmpty(&dotEnd->commands) ||
            !Lst_IsEmpty(&dotEnd->children)) {
                if (job_errors != 0)
                        Error("Errors reported so .END ignored");
                else
                        JobRun(dotEnd);
        }
        return job_errors;
}

#ifdef CLEANUP
void
Job_End(void)
{
        free(shell_freeIt);
}
#endif

/* Waits for all running jobs to finish. */
void
Job_Wait(void)
{
        aborting = ABORT_WAIT;  /* Prevent other jobs from starting. */
        while (jobTokensRunning != 0)
                Job_CatchOutput();
        aborting = ABORT_NONE;
}

/*
 * 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.
 */
void
Job_AbortAll(void)
{
        Job *job;
        int status;

        aborting = ABORT_ERROR;

        if (jobTokensRunning != 0) {
                for (job = job_table; job < job_table_end; job++) {
                        if (job->status != JOB_ST_RUNNING)
                                continue;
                        KILLPG(job->pid, SIGINT);
                        KILLPG(job->pid, SIGKILL);
                }
        }

        while (waitpid((pid_t)-1, &status, WNOHANG) > 0)
                continue;
}

static void
watchfd(Job *job)
{
        if (job->inPollfd != NULL)
                Punt("Watching watched job");

        fds[fdsLen].fd = job->inPipe;
        fds[fdsLen].events = POLLIN;
        jobByFdIndex[fdsLen] = job;
        job->inPollfd = &fds[fdsLen];
        fdsLen++;
#if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
        if (useMeta) {
                fds[fdsLen].fd = meta_job_fd(job);
                fds[fdsLen].events = fds[fdsLen].fd == -1 ? 0 : POLLIN;
                jobByFdIndex[fdsLen] = job;
                fdsLen++;
        }
#endif
}

static void
clearfd(Job *job)
{
        size_t i;
        if (job->inPollfd == NULL)
                Punt("Unwatching unwatched job");
        i = (size_t)(job->inPollfd - fds);
        fdsLen--;
#if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
        if (useMeta) {
                assert(nfds_per_job() == 2);
                if (i % 2 != 0)
                        Punt("odd-numbered fd with meta");
                fdsLen--;
        }
#endif
        /* Move last job in table into hole made by dead job. */
        if (fdsLen != i) {
                fds[i] = fds[fdsLen];
                jobByFdIndex[i] = jobByFdIndex[fdsLen];
                jobByFdIndex[i]->inPollfd = &fds[i];
#if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
                if (useMeta) {
                        fds[i + 1] = fds[fdsLen + 1];
                        jobByFdIndex[i + 1] = jobByFdIndex[fdsLen + 1];
                }
#endif
        }
        job->inPollfd = NULL;
}

int
Job_TempFile(const char *pattern, char *tfile, size_t tfile_sz)
{
        int fd;
        sigset_t mask;

        JobsTable_Lock(&mask);
        fd = mkTempFile(pattern, tfile, tfile_sz);
        if (tfile != NULL && !DEBUG(SCRIPT))
                unlink(tfile);
        JobsTable_Unlock(&mask);

        return fd;
}

static void
TokenPool_Write(char tok)
{
        if (write(tokenPoolJob.outPipe, &tok, 1) != 1)
                Punt("Cannot write \"%c\" to the token pool: %s",
                    tok, strerror(errno));
}

/*
 * Put a token (back) into the job token pool.
 * This allows a make process to start a build job.
 */
static void
TokenPool_Add(void)
{
        char tok = JOB_TOKENS[aborting], tok1;

        /* If we are depositing an error token, flush everything else. */
        while (tok != '+' && read(tokenPoolJob.inPipe, &tok1, 1) == 1)
                continue;

        DEBUG3(JOB, "TokenPool_Add: pid %d, aborting %s, token %c\n",
            getpid(), aborting_name[aborting], tok);
        TokenPool_Write(tok);
}

static void
TokenPool_InitClient(int tokenPoolReader, int tokenPoolWriter)
{
        tokenPoolJob.inPipe = tokenPoolReader;
        tokenPoolJob.outPipe = tokenPoolWriter;
        (void)fcntl(tokenPoolReader, F_SETFD, FD_CLOEXEC);
        (void)fcntl(tokenPoolWriter, F_SETFD, FD_CLOEXEC);
}

/* Prepare the job token pipe in the root make process. */
static void
TokenPool_InitServer(int maxJobTokens)
{
        int i;
        char jobarg[64];

        JobCreatePipe(&tokenPoolJob, 15);

        snprintf(jobarg, sizeof jobarg, "%d,%d",
            tokenPoolJob.inPipe, tokenPoolJob.outPipe);

        Global_Append(MAKEFLAGS, "-J");
        Global_Append(MAKEFLAGS, jobarg);

        /*
         * Preload the job pipe with one token per job, save the one
         * "extra" token for the primary job.
         */
        SetNonblocking(tokenPoolJob.outPipe);
        for (i = 1; i < maxJobTokens; i++)
                TokenPool_Add();
}

void
TokenPool_Init(int maxJobTokens, int tokenPoolReader, int tokenPoolWriter)
{
        if (tokenPoolReader >= 0 && tokenPoolWriter >= 0)
                TokenPool_InitClient(tokenPoolReader, tokenPoolWriter);
        else
                TokenPool_InitServer(maxJobTokens);
}

/* Return a taken token to the pool. */
void
TokenPool_Return(void)
{
        jobTokensRunning--;
        if (jobTokensRunning < 0)
                Punt("token botch");
        if (jobTokensRunning != 0 || JOB_TOKENS[aborting] != '+')
                TokenPool_Add();
}

/*
 * Attempt to take a token from the pool.
 *
 * If the pool is empty, set wantToken so that we wake up when a token is
 * released.
 *
 * Returns true if a token was taken, and false if the pool is currently
 * empty.
 */
bool
TokenPool_Take(void)
{
        char tok, tok1;
        ssize_t count;

        wantToken = false;
        DEBUG3(JOB, "TokenPool_Take: pid %d, aborting %s, running %d\n",
            getpid(), aborting_name[aborting], jobTokensRunning);

        if (aborting != ABORT_NONE || jobTokensRunning >= opts.maxJobs)
                return false;

        count = read(tokenPoolJob.inPipe, &tok, 1);
        if (count == 0)
                Fatal("eof on job pipe");
        if (count < 0 && jobTokensRunning != 0) {
                if (errno != EAGAIN)
                        Fatal("job pipe read: %s", strerror(errno));
                DEBUG1(JOB, "TokenPool_Take: pid %d blocked for token\n",
                    getpid());
                wantToken = true;
                return false;
        }

        if (count == 1 && tok != '+') {
                /* make being aborted - remove any other job tokens */
                DEBUG2(JOB, "TokenPool_Take: pid %d aborted by token %c\n",
                    getpid(), tok);
                while (read(tokenPoolJob.inPipe, &tok1, 1) == 1)
                        continue;
                /* And put the stopper back */
                TokenPool_Write(tok);
                if (shouldDieQuietly(NULL, 1)) {
                        Job_Wait();
                        exit(6);
                }
                Fatal("A failure has been detected "
                      "in another branch of the parallel make");
        }

        if (count == 1 && jobTokensRunning == 0)
                /* We didn't want the token really */
                TokenPool_Write(tok);

        jobTokensRunning++;
        DEBUG1(JOB, "TokenPool_Take: pid %d took a token\n", getpid());
        return true;
}

/* Make the named target if found, exit if the target fails. */
bool
Job_RunTarget(const char *target, const char *fname)
{
        GNode *gn = Targ_FindNode(target);
        if (gn == NULL)
                return false;

        if (fname != NULL)
                Var_Set(gn, ALLSRC, fname);

        JobRun(gn);
        return true;
}

#ifdef USE_SELECT
int
emul_poll(struct pollfd *fd, int nfd, int timeout)
{
        fd_set rfds, wfds;
        int i, maxfd, nselect, npoll;
        struct timeval tv, *tvp;
        long usecs;

        FD_ZERO(&rfds);
        FD_ZERO(&wfds);

        maxfd = -1;
        for (i = 0; i < nfd; i++) {
                fd[i].revents = 0;

                if (fd[i].events & POLLIN)
                        FD_SET(fd[i].fd, &rfds);

                if (fd[i].events & POLLOUT)
                        FD_SET(fd[i].fd, &wfds);

                if (fd[i].fd > maxfd)
                        maxfd = fd[i].fd;
        }

        if (maxfd >= FD_SETSIZE) {
                Punt("Ran out of fd_set slots; "
                     "recompile with a larger FD_SETSIZE.");
        }

        if (timeout < 0) {
                tvp = NULL;
        } else {
                usecs = timeout * 1000;
                tv.tv_sec = usecs / 1000000;
                tv.tv_usec = usecs % 1000000;
                tvp = &tv;
        }

        nselect = select(maxfd + 1, &rfds, &wfds, NULL, tvp);

        if (nselect <= 0)
                return nselect;

        npoll = 0;
        for (i = 0; i < nfd; i++) {
                if (FD_ISSET(fd[i].fd, &rfds))
                        fd[i].revents |= POLLIN;

                if (FD_ISSET(fd[i].fd, &wfds))
                        fd[i].revents |= POLLOUT;

                if (fd[i].revents)
                        npoll++;
        }

        return npoll;
}
#endif                          /* USE_SELECT */