Move ProcExec() into proc.c

[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 1.75 2005/02/10 14:32:14 harti Exp $
 * $DragonFly: src/usr.bin/make/job.c,v 1.108 2005/05/23 18:24:59 okumoto 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_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.
 *
 * compat.c
 *      The routines in this file implement the full-compatibility
 *      mode of PMake. Most of the special functionality of PMake
 *      is available in this mode. Things not supported:
 *          - different shells.
 *          - friendly variable substitution.
 *
 * Interface:
 *      Compat_Run          Initialize things for this module and recreate
 *                          thems as need creatin'
 */

#include <sys/queue.h>
#include <sys/types.h>
#include <sys/select.h>
#include <sys/stat.h>
#ifdef USE_KQUEUE
#include <sys/event.h>
#endif
#include <sys/wait.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <string.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <utime.h>

#include "arch.h"
#include "buf.h"
#include "config.h"
#include "dir.h"
#include "globals.h"
#include "GNode.h"
#include "job.h"
#include "make.h"
#include "parse.h"
#include "pathnames.h"
#include "proc.h"
#include "shell.h"
#include "str.h"
#include "suff.h"
#include "targ.h"
#include "util.h"
#include "var.h"

#define TMPPAT  "/tmp/makeXXXXXXXXXX"
#define MKLVL_MAXVAL    500
#define MKLVL_ENVVAR    "__MKLVL__"

#ifndef USE_KQUEUE
/*
 * The SEL_ constants determine the maximum amount of time spent in select
 * before coming out to see if a child has finished. SEL_SEC is the number of
 * seconds and SEL_USEC is the number of micro-seconds
 */
#define SEL_SEC         2
#define SEL_USEC        0
#endif /* !USE_KQUEUE */

/*
 * Job Table definitions.
 *
 * The job "table" is kept as a linked Lst in 'jobs', with the number of
 * active jobs maintained in the 'nJobs' variable. At no time will this
 * exceed the value of 'maxJobs', initialized by the Job_Init function.
 *
 * When a job is finished, the Make_Update function is called on each of the
 * parents of the node which was just remade. This takes care of the upward
 * traversal of the dependency graph.
 */
#define JOB_BUFSIZE     1024
typedef struct Job {
        pid_t           pid;    /* The child's process ID */

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

        /*
         * A LstNode for the first command to be saved after the job completes.
         * This is NULL if there was no "..." in the job's commands.
         */
        LstNode         *tailCmds;

        /*
         * An FILE* for writing out the commands. This is only
         * used before the job is actually started.
         */
        FILE            *cmdFILE;

        /*
         * A word of flags which determine how the module handles errors,
         * echoing, etc. for the job
         */
        short           flags;  /* Flags to control treatment of job */
#define JOB_IGNERR      0x001   /* Ignore non-zero exits */
#define JOB_SILENT      0x002   /* no output */
#define JOB_SPECIAL     0x004   /* Target is a special one. i.e. run it locally
                                 * if we can't export it and maxLocal is 0 */
#define JOB_IGNDOTS     0x008   /* Ignore "..." lines when processing
                                 * commands */
#define JOB_FIRST       0x020   /* Job is first job for the node */
#define JOB_RESTART     0x080   /* Job needs to be completely restarted */
#define JOB_RESUME      0x100   /* Job needs to be resumed b/c it stopped,
                                 * for some reason */
#define JOB_CONTINUING  0x200   /* We are in the process of resuming this job.
                                 * Used to avoid infinite recursion between
                                 * JobFinish and JobRestart */

        /* union for handling shell's output */
        union {
                /*
                 * This part is used when usePipes is true.
                 * The output is being caught via a pipe and the descriptors
                 * of our pipe, an array in which output is line buffered and
                 * the current position in that buffer are all maintained for
                 * each job.
                 */
                struct {
                        /*
                         * Input side of pipe associated with
                         * job's output channel
                         */
                        int     op_inPipe;

                        /*
                         * Output side of pipe associated with job's
                         * output channel
                         */
                        int     op_outPipe;

                        /*
                         * Buffer for storing the output of the
                         * job, line by line
                         */
                        char    op_outBuf[JOB_BUFSIZE + 1];

                        /* Current position in op_outBuf */
                        int     op_curPos;
                }       o_pipe;

                /*
                 * If usePipes is false the output is routed to a temporary
                 * file and all that is kept is the name of the file and the
                 * descriptor open to the file.
                 */
                struct {
                        /* Name of file to which shell output was rerouted */
                        char    of_outFile[sizeof(TMPPAT)];

                        /*
                         * Stream open to the output file. Used to funnel all
                         * from a single job to one file while still allowing
                         * multiple shell invocations
                         */
                        int     of_outFd;
                }       o_file;

        } output;       /* Data for tracking a shell's output */

        TAILQ_ENTRY(Job) link;  /* list link */
} Job;

#define outPipe         output.o_pipe.op_outPipe
#define inPipe          output.o_pipe.op_inPipe
#define outBuf          output.o_pipe.op_outBuf
#define curPos          output.o_pipe.op_curPos
#define outFile         output.o_file.of_outFile
#define outFd           output.o_file.of_outFd

TAILQ_HEAD(JobList, Job);

/*
 * 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;

/*
 * The number of commands actually printed for a target. Should this
 * number be 0, no shell will be executed.
 */
static int      numCommands;

/*
 * 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 */

/*
 * The maximum number of jobs that may run. This is initialize from the
 * -j argument for the leading make and from the FIFO for sub-makes.
 */
static int      maxJobs;
static int      nJobs;          /* The number of children currently running */

/* The structures that describe them */
static struct JobList jobs = TAILQ_HEAD_INITIALIZER(jobs);

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 */
#ifdef USE_KQUEUE
static int      kqfd;           /* File descriptor obtained by kqueue() */
#else
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 const char *targFmt;     /* Format string to use to head output from a
                                 * job when it's not the most-recent job heard
                                 * from */

#define TARG_FMT  "--- %s ---\n" /* Default format */
#define MESSAGE(fp, gn) \
         fprintf(fp, targFmt, gn->name);

/*
 * When JobStart attempts to run a job but isn't allowed to
 * or when Job_CatchChildren detects a job that has
 * been stopped somehow, the job is placed on the stoppedJobs queue to be run
 * when the next job finishes.
 *
 * Lst of Job structures describing jobs that were stopped due to
 * concurrency limits or externally
 */
static struct JobList stoppedJobs = TAILQ_HEAD_INITIALIZER(stoppedJobs);

static int      fifoFd;         /* Fd of our job fifo */
static char     fifoName[] = "/tmp/make_fifo_XXXXXXXXX";
static int      fifoMaster;

static sig_atomic_t interrupted;


#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 void JobRestart(Job *);
static int JobStart(GNode *, int, Job *);
static void JobDoOutput(Job *, Boolean);
static void JobInterrupt(int, int);
static void JobRestartJobs(void);
static int Compat_RunCommand(char *, struct GNode *);

static GNode        *curTarg = NULL;
static GNode        *ENDNode;

/**
 * Create a fifo file with a uniq filename, and returns a file
 * descriptor to that fifo.
 */
static int
mkfifotemp(char *template)
{
        char *start;
        char *pathend;
        char *ptr;
        const char padchar[] =
            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

        if (template[0] == '\0') {
                errno = EINVAL; /* bad input string */
                return (-1);
        }

        /* Find end of template string. */
        pathend = strchr(template, '\0');
        ptr = pathend - 1;

        /*
         * Starting from the end of the template replace spaces with 'X' in
         * them with random characters until there are no more 'X'.
         */
        while (ptr >= template && *ptr == 'X') {
                uint32_t rand_num = arc4random() % (sizeof(padchar) - 1);
                *ptr-- = padchar[rand_num];
        }
        start = ptr + 1;

        /* Check the target directory. */
        for (; ptr > template; --ptr) {
                if (*ptr == '/') {
                        struct stat sbuf;

                        *ptr = '\0';
                        if (stat(template, &sbuf) != 0)
                                return (-1);

                        if (!S_ISDIR(sbuf.st_mode)) {
                                errno = ENOTDIR;
                                return (-1);
                        }
                        *ptr = '/';
                        break;
                }
        }

        for (;;) {
                if (mkfifo(template, 0600) == 0) {
                        int fd;

                        if ((fd = open(template, O_RDWR, 0600)) < 0) {
                                unlink(template);
                                return (-1);
                        } else {
                                return (fd);
                        }
                } else {
                        if (errno != EEXIST) {
                                return (-1);
                        }
                }

                /*
                 * If we have a collision, cycle through the space of
                 * filenames.
                 */
                for (ptr = start;;) {
                        char *pad;

                        if (*ptr == '\0' || ptr == pathend)
                                return (-1);

                        pad = strchr(padchar, *ptr);
                        if (pad == NULL || *++pad == '\0') {
                                *ptr++ = padchar[0];
                        } else {
                                *ptr++ = *pad;
                                break;
                        }
                }
        }
        /*NOTREACHED*/
}

static void
catch_child(int sig __unused)
{
}

/**
 * In lieu of a good way to prevent every possible looping in make(1), stop
 * there from being more than MKLVL_MAXVAL processes forked by make(1), to
 * prevent a forkbomb from happening, in a dumb and mechanical way.
 *
 * Side Effects:
 *      Creates or modifies enviornment variable MKLVL_ENVVAR via setenv().
 */
static void
check_make_level(void)
{
        char    *value = getenv(MKLVL_ENVVAR);
        int     level = (value == NULL) ? 0 : atoi(value);

        if (level < 0) {
                errc(2, EAGAIN, "Invalid value for recursion level (%d).",
                    level);
        } else if (level > MKLVL_MAXVAL) {
                errc(2, EAGAIN, "Max recursion level (%d) exceeded.",
                    MKLVL_MAXVAL);
        } else {
                char new_value[32];
                sprintf(new_value, "%d", level + 1);
                setenv(MKLVL_ENVVAR, new_value, 1);
        }
}

/**
 */
void
Proc_Init()
{
        /*
         * Catch SIGCHLD so that we get kicked out of select() when we
         * need to look at a child.  This is only known to matter for the
         * -j case (perhaps without -P).
         *
         * XXX this is intentionally misplaced.
         */
        struct sigaction sa;

        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART | SA_NOCLDSTOP;
        sa.sa_handler = catch_child;
        sigaction(SIGCHLD, &sa, NULL);

        check_make_level();

#ifdef RLIMIT_NOFILE
        /*
         * get rid of resource limit on file descriptors
         */
        {
                struct rlimit rl;
                if (getrlimit(RLIMIT_NOFILE, &rl) == -1) {
                        err(2, "getrlimit");
                }
                rl.rlim_cur = rl.rlim_max;
                if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
                        err(2, "setrlimit");
                }
        }
#endif

#if DEFSHELL == 2
        /*
         * Turn off ENV to make ksh happier.
         */
        unsetenv("ENV");
#endif
}

/**
 * Wait for child process to terminate.
 */
static int
ProcWait(ProcStuff *ps)
{
        pid_t   pid;
        int     status;

        /*
         * Wait for the process to exit.
         */
        for (;;) {
                pid = waitpid(ps->child_pid, &status, 0);
                if (pid == -1 && errno != EINTR) {
                        Fatal("error in wait: %d", pid);
                        /* NOTREACHED */
                }
                if (pid == ps->child_pid) {
                        break;
                }
                if (interrupted) {
                        break;
                }
        }

        return (status);
}

/**
 * JobCatchSignal
 *      Got a signal. Set global variables and hope that someone will
 *      handle it.
 */
static void
JobCatchSig(int signo)
{

        interrupted = signo;
}

/**
 * JobPassSig
 *      Pass a signal on to all local jobs if
 *      USE_PGRP is defined, then die ourselves.
 *
 * Side Effects:
 *      We die by the same signal.
 */
static void
JobPassSig(int signo)
{
        Job     *job;
        sigset_t nmask, omask;
        struct sigaction act;

        sigemptyset(&nmask);
        sigaddset(&nmask, signo);
        sigprocmask(SIG_SETMASK, &nmask, &omask);

        DEBUGF(JOB, ("JobPassSig(%d) called.\n", signo));
        TAILQ_FOREACH(job, &jobs, link) {
                DEBUGF(JOB, ("JobPassSig passing signal %d to child %jd.\n",
                    signo, (intmax_t)job->pid));
                KILL(job->pid, 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.
         * XXX this comment seems wrong.
         */
        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))));
        signal(signo, SIG_DFL);

        KILL(getpid(), signo);

        signo = SIGCONT;
        TAILQ_FOREACH(job, &jobs, link) {
                DEBUGF(JOB, ("JobPassSig passing signal %d to child %jd.\n",
                    signo, (intmax_t)job->pid));
                KILL(job->pid, signo);
        }

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

/**
 * 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(char *cmd, Job *job)
{
        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 */
        const char *cmdTemplate;/* Template to use when printing the command */
        char    *cmdStart;      /* Start of expanded command */
        LstNode *cmdNode;       /* Node for replacing the command */

        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, cmd));
                        return (1);
                }
                return (0);
        }

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

        cmd = Buf_Peel(Var_Subst(cmd, job->node, FALSE));
        cmdStart = cmd;

        Lst_Replace(cmdNode, cmdStart);

        cmdTemplate = "%s\n";

        /*
         * Check for leading @', -' or +'s to control echoing, error checking,
         * and execution on -n.
         */
        while (*cmd == '@' || *cmd == '-' || *cmd == '+') {
                switch (*cmd) {

                  case '@':
                        shutUp = DEBUG(LOUD) ? FALSE : TRUE;
                        break;

                  case '-':
                        errOff = TRUE;
                        break;

                  case '+':
                        if (noSpecials) {
                                /*
                                 * We're not actually exececuting anything...
                                 * but this one needs to be - use compat mode
                                 * just for it.
                                 */
                                Compat_RunCommand(cmd, job->node);
                                return (0);
                        }
                        break;
                }
                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);
}

/**
 * JobClose
 *      Called to close both input and output pipes when a job is finished.
 *
 * Side Effects:
 *      The file descriptors associated with the job are closed.
 */
static void
JobClose(Job *job)
{

        if (usePipes) {
#if !defined(USE_KQUEUE)
                FD_CLR(job->inPipe, &outputs);
#endif
                if (job->outPipe != job->inPipe) {
                        close(job->outPipe);
                }
                JobDoOutput(job, TRUE);
                close(job->inPipe);
        } else {
                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.
 *
 * 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.
 */
static void
JobFinish(Job *job, int *status)
{
        Boolean done;
        LstNode *ln;

        if (WIFEXITED(*status)) {
                int     job_status = WEXITSTATUS(*status);

                JobClose(job);
                /*
                 * 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.
                 */
                if (job_status == 0) {
                        done = FALSE;
                } else {
                        if (job->flags & JOB_IGNERR) {
                                done = TRUE;
                        } else {
                                /*
                                 * 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...
                                 */
                                done = TRUE;
                                if (job->cmdFILE != NULL &&
                                    job->cmdFILE != stdout) {
                                        fclose(job->cmdFILE);
                                }

                        }
                }
        } else if (WIFSIGNALED(*status)) {
                if (WTERMSIG(*status) == SIGCONT) {
                        /*
                         * No need to close things down or anything.
                         */
                        done = FALSE;
                } else {
                        /*
                         * 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...
                         */
                        JobClose(job);
                        if (job->cmdFILE != NULL &&
                            job->cmdFILE != stdout) {
                                fclose(job->cmdFILE);
                        }
                        done = TRUE;
                }
        } else {
                /*
                 * No need to close things down or anything.
                 */
                done = FALSE;
        }

        if (WIFEXITED(*status)) {
                if (done || 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;
                        }

                        DEBUGF(JOB, ("Process %jd exited.\n",
                            (intmax_t)job->pid));

                        if (WEXITSTATUS(*status) == 0) {
                                if (DEBUG(JOB)) {
                                        if (usePipes && job->node != lastNode) {
                                                MESSAGE(out, job->node);
                                                lastNode = job->node;
                                        }
                                        fprintf(out,
                                            "*** Completed successfully\n");
                                }
                        } else {
                                if (usePipes && job->node != lastNode) {
                                        MESSAGE(out, job->node);
                                        lastNode = job->node;
                                }
                                fprintf(out, "*** Error code %d%s\n",
                                        WEXITSTATUS(*status),
                                        (job->flags & JOB_IGNERR) ?
                                        "(ignored)" : "");

                                if (job->flags & JOB_IGNERR) {
                                        *status = 0;
                                }
                        }

                        fflush(out);
                }
        } else if (WIFSIGNALED(*status)) {
                if (done || DEBUG(JOB) || (WTERMSIG(*status) == SIGCONT)) {
                        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 (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_RESTART)) {
                                        if (usePipes && job->node != lastNode) {
                                                MESSAGE(out, job->node);
                                                lastNode = job->node;
                                        }
                                        fprintf(out, "*** Continued\n");
                                }
                                if (!(job->flags & JOB_CONTINUING)) {
                                        DEBUGF(JOB, ("Warning: process %jd was not "
                                                     "continuing.\n", (intmax_t) 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;
                                TAILQ_INSERT_TAIL(&jobs, job, link);
                                nJobs += 1;
                                DEBUGF(JOB, ("Process %jd is continuing locally.\n",
                                             (intmax_t) job->pid));
                                if (nJobs == maxJobs) {
                                        jobFull = TRUE;
                                        DEBUGF(JOB, ("Job queue is full.\n"));
                                }
                                fflush(out);
                                return;

                        } else {
                                if (usePipes && job->node != lastNode) {
                                        MESSAGE(out, job->node);
                                        lastNode = job->node;
                                }
                                fprintf(out,
                                    "*** Signal %d\n", WTERMSIG(*status));
                                fflush(out);
                        }
                }
        } else {
                /* STOPPED */
                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;
                }

                DEBUGF(JOB, ("Process %jd stopped.\n", (intmax_t) job->pid));
                if (usePipes && job->node != lastNode) {
                        MESSAGE(out, job->node);
                        lastNode = job->node;
                }
                fprintf(out, "*** Stopped -- signal %d\n", WSTOPSIG(*status));
                job->flags |= JOB_RESUME;
                TAILQ_INSERT_TAIL(&stoppedJobs, job, link);
                fflush(out);
                return;
        }

        /*
         * 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_Succ(job->node->compat_command) != NULL) {
                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;
                  default:
                        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.
                 */
                for (ln = job->tailCmds; ln != NULL; ln = LST_NEXT(ln)) {
                        Lst_AtEnd(&postCommands->commands,
                            Buf_Peel(
                                Var_Subst(Lst_Datum(ln), job->node, FALSE)));
                }

                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.
 *
 * 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) {
                fprintf(stdout, "touch %s\n", gn->name);
                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) {
                                        lseek(streamID, (off_t)0, SEEK_SET);
                                        write(streamID, &c, 1);
                                }

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

                } 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) {
                                fprintf(stdout, "%s %s(ignored)\n",
                                    msg, gn->name);
                                fflush(stdout);
                        } else if (keepgoing) {
                                fprintf(stdout, "%s %s(continuing)\n",
                                    msg, gn->name);
                                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);
}

/**
 * JobExec
 *      Execute the shell for the given job. Called from JobStart and
 *      JobRestart.
 *
 * 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)
{
        ProcStuff       ps;

        if (DEBUG(JOB)) {
                int       i;

                DEBUGF(JOB, ("Running %s\n", job->node->name));
                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;
        }

        ps.in = FILENO(job->cmdFILE);
        if (usePipes) {
                /*
                 * Set up the child's output to be routed through the
                 * pipe we've created for it.
                 */
                ps.out = job->outPipe;
        } else {
                /*
                 * We're capturing output in a file, so we duplicate
                 * the descriptor to the temporary file into the
                 * standard output.
                 */
                ps.out = job->outFd;
        }
        ps.err = STDERR_FILENO;

        ps.merge_errors = 1;
        ps.pgroup = 1;
        ps.searchpath = 0;

        ps.argv = argv;
        ps.argv_free = 0;

        /*
         * Fork.  Warning since we are doing vfork() instead of fork(),
         * do not allocate memory in the child process!
         */
        if ((ps.child_pid = vfork()) == -1) {
                Punt("Cannot fork");

        } else if (ps.child_pid == 0) {
                /*
                 * Child
                 */
                if (fifoFd >= 0)
                        close(fifoFd);

                ProcExec(&ps);
                /* NOTREACHED */

        } else {
                /*
                 * Parent
                 */
                job->pid = ps.child_pid;

                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.
                         */
#ifdef USE_KQUEUE
                        struct kevent   kev[2];
#endif
                        job->curPos = 0;

#if defined(USE_KQUEUE)
                        EV_SET(&kev[0], job->inPipe, EVFILT_READ, EV_ADD, 0, 0, job);
                        EV_SET(&kev[1], job->pid, EVFILT_PROC,
                            EV_ADD | EV_ONESHOT, NOTE_EXIT, 0, NULL);
                        if (kevent(kqfd, kev, 2, NULL, 0, NULL) != 0) {
                                /*
                                 * kevent() will fail if the job is already
                                 * finished
                                 */
                                if (errno != EINTR && errno != EBADF && errno != ESRCH)
                                        Punt("kevent: %s", strerror(errno));
                        }
#else
                        FD_SET(job->inPipe, &outputs);
#endif /* USE_KQUEUE */
                }

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

                /*
                 * Now the job is actually running, add it to the table.
                 */
                nJobs += 1;
                TAILQ_INSERT_TAIL(&jobs, job, link);
                if (nJobs == maxJobs) {
                        jobFull = TRUE;
                }
        }
}

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

        argv[0] = commandShell->name;
        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.
                 */
                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. The job must be neither
 *      on the jobs nor on the stoppedJobs list.
 *
 * Side Effects:
 *      jobFull will be set if the job couldn't be run.
 */
static void
JobRestart(Job *job)
{

        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));
                if (nJobs >= maxJobs && !(job->flags & JOB_SPECIAL)) {
                        /*
                         * Not allowed to run -- put it back on the hold
                         * queue and mark the table full
                         */
                        DEBUGF(JOB, ("holding\n"));
                        TAILQ_INSERT_HEAD(&stoppedJobs, job, link);
                        jobFull = TRUE;
                        DEBUGF(JOB, ("Job queue is full.\n"));
                        return;
                } else {
                        /*
                         * Job may be run locally.
                         */
                        DEBUGF(JOB, ("running locally\n"));
                }
                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 ((nJobs < maxJobs || ((job->flags & JOB_SPECIAL) &&
                    maxJobs == 0)) && nJobs != maxJobs) {
                        /*
                         * If we haven't reached the concurrency limit already
                         * (or the job must be run and maxJobs is 0), it's ok
                         * to resume it.
                         */
                        Boolean error;
                        int status;

                        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;
                                status = 0;
                                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"));
                        TAILQ_INSERT_HEAD(&stoppedJobs, job, link);
                        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 noExec;         /* Set true if we decide not to run the job */
        int     tfd;            /* File descriptor for temp file */
        LstNode *ln;
        char    tfile[sizeof(TMPPAT)];

        if (interrupted) {
                JobPassSig(interrupted);
                return (JOB_ERROR);
        }
        if (previous != NULL) {
                previous->flags &= ~(JOB_FIRST | JOB_IGNERR | JOB_SILENT);
                job = previous;
        } else {
                job = emalloc(sizeof(Job));
                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();
                }

                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);
                }
                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)
                                gn->compat_command = Lst_First(&gn->commands);
                        else
                                gn->compat_command =
                                    Lst_Succ(gn->compat_command);

                        if (gn->compat_command == NULL ||
                            JobPrintCommand(Lst_Datum(gn->compat_command), job))
                                noExec = TRUE;

                        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(ln, &gn->commands) {
                                if (JobPrintCommand(Lst_Datum(ln), job))
                                        break;
                        }

                        /*
                         * 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(ln, &gn->commands) {
                                if (JobPrintCommand(Lst_Datum(ln), job))
                                        break;
                        }
                }
                /*
                * 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)
                                fclose(job->cmdFILE);
                } else {
                        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) {
                                for (ln = job->tailCmds; ln != NULL;
                                    ln = LST_NEXT(ln)) {
                                        Lst_AtEnd(&postCommands->commands,
                                            Buf_Peel(Var_Subst(Lst_Datum(ln),
                                            job->node, FALSE)));
                                }
                                job->node->made = MADE;
                                Make_Update(job->node);
                        }
                        free(job);
                        return(JOB_FINISHED);
                } else {
                        free(job);
                        return(JOB_ERROR);
                }
        } else {
                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];
                        fcntl(job->inPipe, F_SETFD, 1);
                        fcntl(job->outPipe, F_SETFD, 1);
                } else {
                        fprintf(stdout, "Remaking `%s'\n", gn->name);
                        fflush(stdout);
                        strcpy(job->outFile, TMPPAT);
                        if ((job->outFd = mkstemp(job->outFile)) == -1)
                                Punt("cannot create temp file: %s",
                                    strerror(errno));
                        fcntl(job->outFd, F_SETFD, 1);
                }
        }

        if (nJobs >= maxJobs && !(job->flags & JOB_SPECIAL) && maxJobs != 0) {
                /*
                 * We've hit the limit of concurrency, so put the job on hold
                 * until some other job finishes. Note that the special jobs
                 * (.BEGIN, .INTERRUPT and .END) may be run even when the
                 * limit has been reached (e.g. when maxJobs == 0).
                 */
                jobFull = TRUE;

                DEBUGF(JOB, ("Can only run job locally.\n"));
                job->flags |= JOB_RESTART;
                TAILQ_INSERT_TAIL(&stoppedJobs, job, link);
        } else {
                if (nJobs >= maxJobs) {
                        /*
                         * If we're running this job 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.
                                 */
                                fprintf(stdout, "%s", cp);
                                fflush(stdout);
                        }
                        cp = ecp + strlen(commandShell->noPrint);
                        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.
 *
 * 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);
                /*
                 * Check for interrupt here too, because the above read may
                 * block when the child process is stopped. In this case the
                 * interrupt will unblock it (we don't use SA_RESTART).
                 */
                if (interrupted)
                        JobPassSig(interrupted);

                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 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;
                                        }
                                        fprintf(stdout, "%s%s", cp,
                                            gotNL ? "\n" : "");
                                        fflush(stdout);
                                }
                        }
                        if (i < max - 1) {
                                /* shift the remaining characters down */
                                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) {
                        fprintf(stdout, "Results of making %s:\n",
                            job->node->name);
                        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 buffer. This time,
                                 * though, we know there's no newline at the
                                 * end, so we add one of our own free will.
                                 */
                                fprintf(stdout, "%s", cp);
                                fflush(stdout);
                                if (endp != oendp) {
                                        fprintf(stdout, "\n");
                                        fflush(stdout);
                                }
                        }
                        fclose(oFILE);
                        eunlink(job->outFile);
                }
        }
}

/**
 * Job_CatchChildren
 *      Handle the exit of a child. Called from Make_Make.
 *
 * 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)
{
        pid_t   pid;    /* pid of dead child */
        Job     *job;   /* job descriptor for dead child */
        int     status; /* Exit/termination status */

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

        for (;;) {
                pid = waitpid((pid_t)-1, &status,
                    (block ? 0 : WNOHANG) | WUNTRACED);
                if (pid <= 0)
                        break;

                DEBUGF(JOB, ("Process %jd exited or stopped.\n",
                    (intmax_t)pid));

                TAILQ_FOREACH(job, &jobs, link) {
                        if (job->pid == pid)
                                break;
                }

                if (job == NULL) {
                        if (WIFSIGNALED(status) &&
                            (WTERMSIG(status) == SIGCONT)) {
                                TAILQ_FOREACH(job, &jobs, link) {
                                        if (job->pid == pid)
                                                break;
                                }
                                if (job == NULL) {
                                        Error("Resumed child (%jd) "
                                            "not in table", (intmax_t)pid);
                                        continue;
                                }
                                TAILQ_REMOVE(&stoppedJobs, job, link);
                        } else {
                                Error("Child (%jd) not in table?",
                                    (intmax_t)pid);
                                continue;
                        }
                } else {
                        TAILQ_REMOVE(&jobs, job, link);
                        nJobs -= 1;
                        if (fifoFd >= 0 && maxJobs > 1) {
                                write(fifoFd, "+", 1);
                                maxJobs--;
                                if (nJobs >= maxJobs)
                                        jobFull = TRUE;
                                else
                                        jobFull = FALSE;
                        } else {
                                DEBUGF(JOB, ("Job queue is no longer full.\n"));
                                jobFull = FALSE;
                        }
                }

                JobFinish(job, &status);
        }
        if (interrupted)
                JobPassSig(interrupted);
}

/**
 * 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.
 *
 * Side Effects:
 *      Output is read from pipes if we're piping.
 */
void
#ifdef USE_KQUEUE
Job_CatchOutput(int flag __unused)
#else
Job_CatchOutput(int flag)
#endif
{
        int             nfds;
#ifdef USE_KQUEUE
#define KEV_SIZE        4
        struct kevent   kev[KEV_SIZE];
        int             i;
#else
        struct timeval  timeout;
        fd_set          readfds;
        Job             *job;
#endif

        fflush(stdout);

        if (usePipes) {
#ifdef USE_KQUEUE
                if ((nfds = kevent(kqfd, NULL, 0, kev, KEV_SIZE, NULL)) == -1) {
                        if (errno != EINTR)
                                Punt("kevent: %s", strerror(errno));
                        if (interrupted)
                                JobPassSig(interrupted);
                } else {
                        for (i = 0; i < nfds; i++) {
                                if (kev[i].flags & EV_ERROR) {
                                        warnc(kev[i].data, "kevent");
                                        continue;
                                }
                                switch (kev[i].filter) {
                                  case EVFILT_READ:
                                        JobDoOutput(kev[i].udata, FALSE);
                                        break;
                                  case EVFILT_PROC:
                                        /*
                                         * Just wake up and let
                                         * Job_CatchChildren() collect the
                                         * terminated job.
                                         */
                                        break;
                                }
                        }
                }
#else
                readfds = outputs;
                timeout.tv_sec = SEL_SEC;
                timeout.tv_usec = SEL_USEC;
                if (flag && jobFull && fifoFd >= 0)
                        FD_SET(fifoFd, &readfds);

                nfds = select(FD_SETSIZE, &readfds, (fd_set *)NULL,
                    (fd_set *)NULL, &timeout);
                if (nfds <= 0) {
                        if (interrupted)
                                JobPassSig(interrupted);
                        return;
                }
                if (fifoFd >= 0 && FD_ISSET(fifoFd, &readfds)) {
                        if (--nfds <= 0)
                                return;
                }
                job = TAILQ_FIRST(&jobs);
                while (nfds != 0 && job != NULL) {
                        if (FD_ISSET(job->inPipe, &readfds)) {
                                JobDoOutput(job, FALSE);
                                nfds--;
                        }
                        job = TAILQ_NEXT(job, link);
                }
#endif /* !USE_KQUEUE */
        }
}

/**
 * Job_Make
 *      Start the creation of a target. Basically a front-end for
 *      JobStart used by the Make module.
 *
 * Side Effects:
 *      Another job is started.
 */
void
Job_Make(GNode *gn)
{

        JobStart(gn, 0, NULL);
}

/**
 * Job_Init
 *      Initialize the process module, given a maximum number of jobs.
 *
 * Side Effects:
 *      lists and counters are initialized
 */
void
Job_Init(int maxproc)
{
        GNode           *begin; /* node for commands to do at the very start */
        const char      *env;
        struct sigaction sa;

        fifoFd = -1;
        env = getenv("MAKE_JOBS_FIFO");

        if (env == NULL && maxproc > 1) {
                /*
                 * We did not find the environment variable so we are the
                 * leader. Create the fifo, open it, write one char per
                 * allowed job into the pipe.
                 */
                fifoFd = mkfifotemp(fifoName);
                if (fifoFd < 0) {
                        env = NULL;
                } else {
                        fifoMaster = 1;
                        fcntl(fifoFd, F_SETFL, O_NONBLOCK);
                        env = fifoName;
                        setenv("MAKE_JOBS_FIFO", env, 1);
                        while (maxproc-- > 0) {
                                write(fifoFd, "+", 1);
                        }
                        /* The master make does not get a magic token */
                        jobFull = TRUE;
                        maxJobs = 0;
                }

        } else if (env != NULL) {
                /*
                 * We had the environment variable so we are a slave.
                 * Open fifo and give ourselves a magic token which represents
                 * the token our parent make has grabbed to start his make
                 * process. Otherwise the sub-makes would gobble up tokens and
                 * the proper number of tokens to specify to -j would depend
                 * on the depth of the tree and the order of execution.
                 */
                fifoFd = open(env, O_RDWR, 0);
                if (fifoFd >= 0) {
                        fcntl(fifoFd, F_SETFL, O_NONBLOCK);
                        maxJobs = 1;
                        jobFull = FALSE;
                }
        }
        if (fifoFd <= 0) {
                maxJobs = maxproc;
                jobFull = FALSE;
        } else {
        }
        nJobs = 0;

        aborting = 0;
        errors = 0;

        lastNode = NULL;

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

        /*
         * Catch the four signals that POSIX specifies if they aren't ignored.
         * JobCatchSignal will just set global variables and hope someone
         * else is going to handle the interrupt.
         */
        sa.sa_handler = JobCatchSig;
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = 0;

        if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
                sigaction(SIGINT, &sa, NULL);
        }
        if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
                sigaction(SIGHUP, &sa, NULL);
        }
        if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) {
                sigaction(SIGQUIT, &sa, NULL);
        }
        if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
                sigaction(SIGTERM, &sa, NULL);
        }
        /*
         * 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(USE_PGRP)
        if (signal(SIGTSTP, SIG_IGN) != SIG_IGN) {
                sigaction(SIGTSTP, &sa, NULL);
        }
        if (signal(SIGTTOU, SIG_IGN) != SIG_IGN) {
                sigaction(SIGTTOU, &sa, NULL);
        }
        if (signal(SIGTTIN, SIG_IGN) != SIG_IGN) {
                sigaction(SIGTTIN, &sa, NULL);
        }
        if (signal(SIGWINCH, SIG_IGN) != SIG_IGN) {
                sigaction(SIGWINCH, &sa, NULL);
        }
#endif

#ifdef USE_KQUEUE
        if ((kqfd = kqueue()) == -1) {
                Punt("kqueue: %s", strerror(errno));
        }
#endif

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

        if (begin != NULL) {
                JobStart(begin, JOB_SPECIAL, (Job *)NULL);
                while (nJobs) {
                        Job_CatchOutput(0);
                        Job_CatchChildren(!usePipes);
                }
        }
        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
 */
Boolean
Job_Full(void)
{
        char c;
        int i;

        if (aborting)
                return (aborting);
        if (fifoFd >= 0 && jobFull) {
                i = read(fifoFd, &c, 1);
                if (i > 0) {
                        maxJobs++;
                        jobFull = FALSE;
                }
        }
        return (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.
 */
Boolean
Job_Empty(void)
{
        if (nJobs == 0) {
                if (!TAILQ_EMPTY(&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);
        }
}

/**
 * JobInterrupt
 *      Handle the receipt of an interrupt.
 *
 * Side Effects:
 *      All children are killed. Another job will be started if the
 *      .INTERRUPT target was given.
 */
static void
JobInterrupt(int runINTERRUPT, int signo)
{
        Job     *job;           /* job descriptor in that element */
        GNode   *interrupt;     /* the node describing the .INTERRUPT target */

        aborting = ABORT_INTERRUPT;

        TAILQ_FOREACH(job, &jobs, link) {
                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);
                        }
                }
                if (job->pid) {
                        DEBUGF(JOB, ("JobInterrupt passing signal to child "
                            "%jd.\n", (intmax_t)job->pid));
                        KILL(job->pid, signo);
                }
        }

        if (runINTERRUPT && !touchFlag) {
                /*
                 * clear the interrupted flag because we would get an
                 * infinite loop otherwise.
                 */
                interrupted = 0;

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

                        JobStart(interrupt, JOB_IGNDOTS, (Job *)NULL);
                        while (nJobs) {
                                Job_CatchOutput(0);
                                Job_CatchChildren(!usePipes);
                        }
                }
        }
}

/**
 * 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(0);
                                Job_CatchChildren(!usePipes);
                        }
                }
        }
        if (fifoFd >= 0) {
                close(fifoFd);
                fifoFd = -1;
                if (fifoMaster)
                        unlink(fifoName);
        }
        return (errors);
}

/**
 * Job_Wait
 *      Waits for all running jobs to finish and returns. Sets 'aborting'
 *      to ABORT_WAIT to prevent other jobs from starting.
 *
 * Side Effects:
 *      Currently running jobs finish.
 */
void
Job_Wait(void)
{

        aborting = ABORT_WAIT;
        while (nJobs != 0) {
                Job_CatchOutput(0);
                Job_CatchChildren(!usePipes);
        }
        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.
 *
 * Side Effects:
 *      All children are killed, not just the firstborn
 */
void
Job_AbortAll(void)
{
        Job     *job;   /* the job descriptor in that element */
        int     status;

        aborting = ABORT_ERROR;

        if (nJobs) {
                TAILQ_FOREACH(job, &jobs, link) {
                        /*
                         * kill the child process with increasingly drastic
                         * signals to make darn sure it's dead.
                         */
                        KILL(job->pid, SIGINT);
                        KILL(job->pid, SIGKILL);
                }
        }

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

/**
 * 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!
 *
 * Side Effects:
 *      Resumes(and possibly migrates) jobs.
 */
static void
JobRestartJobs(void)
{
        Job *job;

        while (!jobFull && (job = TAILQ_FIRST(&stoppedJobs)) != NULL) {
                DEBUGF(JOB, ("Job queue is not full. "
                    "Restarting a stopped job.\n"));
                TAILQ_REMOVE(&stoppedJobs, job, link);
                JobRestart(job);
        }
}

/**
 * Cmd_Exec
 *      Execute the command in cmd, and return the output of that command
 *      in a string.
 *
 * Results:
 *      A string containing the output of the command, or the empty string
 *      If error is not NULL, it contains the reason for the command failure
 *      Any output sent to stderr in the child process is passed to stderr,
 *      and not captured in the string.
 *
 * Side Effects:
 *      The string must be freed by the caller.
 */
Buffer *
Cmd_Exec(const char *cmd, const char **error)
{
        int     fds[2]; /* Pipe streams */
        int     status; /* command exit status */
        Buffer  *buf;   /* buffer to store the result */
        ssize_t rcnt;
        ProcStuff       ps;

        *error = NULL;
        buf = Buf_Init(0);

        /*
         * Open a pipe for fetching its output
         */
        if (pipe(fds) == -1) {
                *error = "Couldn't create pipe for \"%s\"";
                return (buf);
        }

        /* Set close-on-exec on read side of pipe. */
        fcntl(fds[0], F_SETFD, fcntl(fds[0], F_GETFD) | FD_CLOEXEC);

        ps.in = STDIN_FILENO;
        ps.out = fds[1];
        ps.err = STDERR_FILENO;

        ps.merge_errors = 0;
        ps.pgroup = 0;
        ps.searchpath = 0;

        /* Set up arguments for shell */
        ps.argv = emalloc(4 * sizeof(char *));
        ps.argv[0] = strdup(commandShell->name);
        ps.argv[1] = strdup("-c");
        ps.argv[2] = strdup(cmd);
        ps.argv[3] = NULL;
        ps.argv_free = 1;

        /*
         * Fork.  Warning since we are doing vfork() instead of fork(),
         * do not allocate memory in the child process!
         */
        if ((ps.child_pid = vfork()) == -1) {
                *error = "Couldn't exec \"%s\"";

        } else if (ps.child_pid == 0) {
                /*
                 * Child
                 */
                ProcExec(&ps);
                /* NOTREACHED */

        } else {
                free(ps.argv[2]);
                free(ps.argv[1]);
                free(ps.argv[0]);
                free(ps.argv);

                close(fds[1]); /* No need for the writing half of the pipe. */

                do {
                        char    result[BUFSIZ];

                        rcnt = read(fds[0], result, sizeof(result));
                        if (rcnt != -1)
                                Buf_AddBytes(buf, (size_t)rcnt, (Byte *)result);
                } while (rcnt > 0 || (rcnt == -1 && errno == EINTR));

                if (rcnt == -1)
                        *error = "Error reading shell's output for \"%s\"";

                /*
                 * Close the input side of the pipe.
                 */
                close(fds[0]);

                status = ProcWait(&ps);
                if (status)
                        *error = "\"%s\" returned non-zero status";

                Buf_StripNewlines(buf);

        }
        return (buf);
}

/*
 * Interrupt handler - set flag and defer handling to the main code
 */
static void
CompatCatchSig(int signo)
{

        interrupted = signo;
}

/**
 * CompatInterrupt
 *      Interrupt the creation of the current target and remove it if
 *      it ain't precious.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      The target is removed and the process exits. If .INTERRUPT exists,
 *      its commands are run first WITH INTERRUPTS IGNORED..
 */
static void
CompatInterrupt(int signo)
{
        GNode           *gn;
        sigset_t        nmask, omask;
        LstNode         *ln;

        sigemptyset(&nmask);
        sigaddset(&nmask, SIGINT);
        sigaddset(&nmask, SIGTERM);
        sigaddset(&nmask, SIGHUP);
        sigaddset(&nmask, SIGQUIT);
        sigprocmask(SIG_SETMASK, &nmask, &omask);

        /* prevent recursion in evaluation of .INTERRUPT */
        interrupted = 0;

        if (curTarg != NULL && !Targ_Precious(curTarg)) {
                const char *file = Var_Value(TARGET, curTarg);

                if (!noExecute && eunlink(file) != -1) {
                        printf("*** %s removed\n", file);
                }
        }

        /*
         * Run .INTERRUPT only if hit with interrupt signal
         */
        if (signo == SIGINT) {
                gn = Targ_FindNode(".INTERRUPT", TARG_NOCREATE);
                if (gn != NULL) {
                        LST_FOREACH(ln, &gn->commands) {
                                if (Compat_RunCommand(Lst_Datum(ln), gn))
                                        break;
                        }
                }
        }

        sigprocmask(SIG_SETMASK, &omask, NULL);

        if (signo == SIGQUIT)
                exit(signo);
        signal(signo, SIG_DFL);
        kill(getpid(), signo);
}

/**
 * Compat_RunCommand
 *      Execute the next command for a target. If the command returns an
 *      error, the node's made field is set to ERROR and creation stops.
 *      The node from which the command came is also given.
 *
 * Results:
 *      0 if the command succeeded, 1 if an error occurred.
 *
 * Side Effects:
 *      The node's 'made' field may be set to ERROR.
 */
static int
Compat_RunCommand(char *cmd, GNode *gn)
{
        ArgArray        aa;
        char            *cmdStart;      /* Start of expanded command */
        Boolean         silent;         /* Don't print command */
        Boolean         doit;           /* Execute even in -n */
        Boolean         errCheck;       /* Check errors */
        int             reason;         /* Reason for child's death */
        int             status;         /* Description of child's death */
        LstNode         *cmdNode;       /* Node where current cmd is located */
        char            **av;           /* Argument vector for thing to exec */
        ProcStuff       ps;

        silent = gn->type & OP_SILENT;
        errCheck = !(gn->type & OP_IGNORE);
        doit = FALSE;

        cmdNode = Lst_Member(&gn->commands, cmd);
        cmdStart = Buf_Peel(Var_Subst(cmd, gn, FALSE));

        if (*cmdStart == '\0') {
                free(cmdStart);
                Error("%s expands to empty string", cmd);
                return (0);
        } else {
                cmd = cmdStart;
        }
        Lst_Replace(cmdNode, cmdStart);

        if ((gn->type & OP_SAVE_CMDS) && (gn != ENDNode)) {
                Lst_AtEnd(&ENDNode->commands, cmdStart);
                return (0);
        } else if (strcmp(cmdStart, "...") == 0) {
                gn->type |= OP_SAVE_CMDS;
                return (0);
        }

        while (*cmd == '@' || *cmd == '-' || *cmd == '+') {
                switch (*cmd) {

                  case '@':
                        silent = DEBUG(LOUD) ? FALSE : TRUE;
                        break;

                  case '-':
                        errCheck = FALSE;
                        break;

                case '+':
                        doit = TRUE;
                        break;
                }
                cmd++;
        }

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

        /*
         * Print the command before echoing if we're not supposed to be quiet
         * for this one. We also print the command if -n given, but not if '+'.
         */
        if (!silent || (noExecute && !doit)) {
                printf("%s\n", cmd);
                fflush(stdout);
        }

        /*
         * If we're not supposed to execute any commands, this is as far as
         * we go...
         */
        if (!doit && noExecute) {
                return (0);
        }

        if (strpbrk(cmd, "#=|^(){};&<>*?[]:$`\\\n")) {
                /*
                 * We found a "meta" character and need to pass the command
                 * off to the shell.
                 */
                av = NULL;

        } else {
                const char **p;
                const char *sh_builtin[] = {
                        "alias", "cd", "eval", "exec",
                        "exit", "read", "set", "ulimit",
                        "unalias", "umask", "unset", "wait",
                        ":", NULL
                };

                /*
                 * Break the command into words to form an argument
                 * vector we can execute.
                 */
                brk_string(&aa, cmd, TRUE);
                av = aa.argv + 1;

                for (p = sh_builtin; *p != 0; p++) {
                        if (strcmp(av[0], *p) == 0) {
                                /*
                                 * This command must be passed by the shell
                                 * for other reasons.. or.. possibly not at
                                 * all.
                                 */
                                av = NULL;
                                break;
                        }
                }
        }

        ps.in = STDIN_FILENO;
        ps.out = STDOUT_FILENO;
        ps.err = STDERR_FILENO;

        ps.merge_errors = 0;
        ps.pgroup = 0;
        ps.searchpath = 1;

        if (av == NULL) {
                /*
                 * We give the shell the -e flag as well as -c if it's
                 * supposed to exit when it hits an error.
                 */
                ps.argv = emalloc(4 * sizeof(char *));
                ps.argv[0] = strdup(commandShell->path);
                ps.argv[1] = strdup(errCheck ? "-ec" : "-c");
                ps.argv[2] = strdup(cmd);
                ps.argv[3] = NULL;
                ps.argv_free = 1;
        } else {
                ps.argv = av;
                ps.argv_free = 0;
        }
        ps.errCheck = errCheck;

        /*
         * Fork and execute the single command. If the fork fails, we abort.
         * Warning since we are doing vfork() instead of fork(),
         * do not allocate memory in the child process!
         */
        if ((ps.child_pid = vfork()) == -1) {
                Fatal("Could not fork");

        } else if (ps.child_pid == 0) {
                /*
                 * Child
                 */
                ProcExec(&ps);
                /* NOTREACHED */

        } else {
                if (ps.argv_free) {
                        free(ps.argv[2]);
                        free(ps.argv[1]);
                        free(ps.argv[0]);
                        free(ps.argv);
                } else {
                        ArgArray_Done(&aa);
                }

                /*
                 * we need to print out the command associated with this
                 * Gnode in Targ_PrintCmd from Targ_PrintGraph when debugging
                 * at level g2, in main(), Fatal() and DieHorribly(),
                 * therefore do not free it when debugging.
                 */
                if (!DEBUG(GRAPH2)) {
                        free(cmdStart);
                }

                /*
                 * The child is off and running. Now all we can do is wait...
                 */
                reason = ProcWait(&ps);

                if (interrupted)
                        CompatInterrupt(interrupted);

                /*
                 * Decode and report the reason child exited, then
                 * indicate how we handled it.
                 */
                if (WIFEXITED(reason)) {
                        status = WEXITSTATUS(reason);
                        if (status == 0) {
                                return (0);
                        } else {
                                printf("*** Error code %d", status);
                        }
                } else if (WIFSTOPPED(reason)) {
                        status = WSTOPSIG(reason);
                } else {
                        status = WTERMSIG(reason);
                        printf("*** Signal %d", status);
                }

                if (ps.errCheck) {
                        gn->made = ERROR;
                        if (keepgoing) {
                                /*
                                 * Abort the current
                                 * target, but let
                                 * others continue.
                                 */
                                printf(" (continuing)\n");
                        }
                        return (status);
                } else {
                        /*
                         * Continue executing
                         * commands for this target.
                         * If we return 0, this will
                         * happen...
                         */
                        printf(" (ignored)\n");
                        return (0);
                }
        }
}

/**
 * CompatMake
 *      Make a target, given the parent, to abort if necessary.
 *
 * Side Effects:
 *      If an error is detected and not being ignored, the process exits.
 */
static int
CompatMake(GNode *gn, GNode *pgn)
{
        LstNode *ln;

        if (gn->type & OP_USE) {
                Make_HandleUse(gn, pgn);

        } else if (gn->made == UNMADE) {
                /*
                 * First mark ourselves to be made, then apply whatever
                 * transformations the suffix module thinks are necessary.
                 * Once that's done, we can descend and make all our children.
                 * If any of them has an error but the -k flag was given, our
                 * 'make' field will be set FALSE again. This is our signal to
                 * not attempt to do anything but abort our parent as well.
                 */
                gn->make = TRUE;
                gn->made = BEINGMADE;
                Suff_FindDeps(gn);
                LST_FOREACH(ln, &gn->children)
                        CompatMake(Lst_Datum(ln), gn);
                if (!gn->make) {
                        gn->made = ABORTED;
                        pgn->make = FALSE;
                        return (0);
                }

                if (Lst_Member(&gn->iParents, pgn) != NULL) {
                        Var_Set(IMPSRC, Var_Value(TARGET, gn), pgn);
                }

                /*
                 * All the children were made ok. Now cmtime contains the
                 * modification time of the newest child, we need to find out
                 * if we exist and when we were modified last. The criteria for
                 * datedness are defined by the Make_OODate function.
                 */
                DEBUGF(MAKE, ("Examining %s...", gn->name));
                if (!Make_OODate(gn)) {
                        gn->made = UPTODATE;
                        DEBUGF(MAKE, ("up-to-date.\n"));
                        return (0);
                } else {
                        DEBUGF(MAKE, ("out-of-date.\n"));
                }

                /*
                 * If the user is just seeing if something is out-of-date,
                 * exit now to tell him/her "yes".
                 */
                if (queryFlag) {
                        exit(1);
                }

                /*
                 * We need to be re-made. We also have to make sure we've got
                 * a $? variable. To be nice, we also define the $> variable
                 * using Make_DoAllVar().
                 */
                Make_DoAllVar(gn);

                /*
                 * Alter our type to tell if errors should be ignored or things
                 * should not be printed so Compat_RunCommand knows what to do.
                 */
                if (Targ_Ignore(gn)) {
                        gn->type |= OP_IGNORE;
                }
                if (Targ_Silent(gn)) {
                        gn->type |= OP_SILENT;
                }

                if (Job_CheckCommands(gn, Fatal)) {
                        /*
                         * Our commands are ok, but we still have to worry
                         * about the -t flag...
                         */
                        if (!touchFlag) {
                                curTarg = gn;
                                LST_FOREACH(ln, &gn->commands) {
                                        if (Compat_RunCommand(Lst_Datum(ln),
                                            gn))
                                                break;
                                }
                                curTarg = NULL;
                        } else {
                                Job_Touch(gn, gn->type & OP_SILENT);
                        }
                } else {
                        gn->made = ERROR;
                }

                if (gn->made != ERROR) {
                        /*
                         * If the node was made successfully, mark it so, update
                         * its modification time and timestamp all its parents.
                         * Note that for .ZEROTIME targets, the timestamping
                         * isn't done. This is to keep its state from affecting
                         * that of its parent.
                         */
                        gn->made = MADE;
#ifndef RECHECK
                        /*
                         * We can't re-stat the thing, but we can at least take
                         * care of rules where a target depends on a source that
                         * actually creates the target, but only if it has
                         * changed, e.g.
                         *
                         * parse.h : parse.o
                         *
                         * parse.o : parse.y
                         *      yacc -d parse.y
                         *      cc -c y.tab.c
                         *      mv y.tab.o parse.o
                         *      cmp -s y.tab.h parse.h || mv y.tab.h parse.h
                         *
                         * In this case, if the definitions produced by yacc
                         * haven't changed from before, parse.h won't have been
                         * updated and gn->mtime will reflect the current
                         * modification time for parse.h. This is something of a
                         * kludge, I admit, but it's a useful one..
                         *
                         * XXX: People like to use a rule like
                         *
                         * FRC:
                         *
                         * To force things that depend on FRC to be made, so we
                         * have to check for gn->children being empty as well...
                         */
                        if (!Lst_IsEmpty(&gn->commands) ||
                            Lst_IsEmpty(&gn->children)) {
                                gn->mtime = now;
                        }
#else
                        /*
                         * This is what Make does and it's actually a good
                         * thing, as it allows rules like
                         *
                         *      cmp -s y.tab.h parse.h || cp y.tab.h parse.h
                         *
                         * to function as intended. Unfortunately, thanks to
                         * the stateless nature of NFS (and the speed of this
                         * program), there are times when the modification time
                         * of a file created on a remote machine will not be
                         * modified before the stat() implied by the Dir_MTime
                         * occurs, thus leading us to believe that the file
                         * is unchanged, wreaking havoc with files that depend
                         * on this one.
                         *
                         * I have decided it is better to make too much than to
                         * make too little, so this stuff is commented out
                         * unless you're sure it's ok.
                         * -- ardeb 1/12/88
                         */
                        if (noExecute || Dir_MTime(gn) == 0) {
                                gn->mtime = now;
                        }
                        if (gn->cmtime > gn->mtime)
                                gn->mtime = gn->cmtime;
                        DEBUGF(MAKE, ("update time: %s\n",
                            Targ_FmtTime(gn->mtime)));
#endif
                        if (!(gn->type & OP_EXEC)) {
                                pgn->childMade = TRUE;
                                Make_TimeStamp(pgn, gn);
                        }

                } else if (keepgoing) {
                        pgn->make = FALSE;

                } else {
                        printf("\n\nStop in %s.\n", Var_Value(".CURDIR", gn));
                        exit(1);
                }
        } else if (gn->made == ERROR) {
                /*
                 * Already had an error when making this beastie. Tell the
                 * parent to abort.
                 */
                pgn->make = FALSE;
        } else {
                if (Lst_Member(&gn->iParents, pgn) != NULL) {
                        Var_Set(IMPSRC, Var_Value(TARGET, gn), pgn);
                }
                switch(gn->made) {
                  case BEINGMADE:
                        Error("Graph cycles through %s\n", gn->name);
                        gn->made = ERROR;
                        pgn->make = FALSE;
                        break;
                  case MADE:
                        if ((gn->type & OP_EXEC) == 0) {
                            pgn->childMade = TRUE;
                            Make_TimeStamp(pgn, gn);
                        }
                        break;
                  case UPTODATE:
                        if ((gn->type & OP_EXEC) == 0) {
                            Make_TimeStamp(pgn, gn);
                        }
                        break;
                  default:
                        break;
                }
        }

        return (0);
}

/**
 * Compat_Run
 *      Start making again, given a list of target nodes.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      Guess what?
 */
void
Compat_Run(Lst *targs)
{
        GNode   *gn = NULL;     /* Current root target */
        int     error_cnt;      /* Number of targets not remade due to errors */
        LstNode *ln;

        if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
                signal(SIGINT, CompatCatchSig);
        }
        if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
                signal(SIGTERM, CompatCatchSig);
        }
        if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
                signal(SIGHUP, CompatCatchSig);
        }
        if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) {
                signal(SIGQUIT, CompatCatchSig);
        }

        ENDNode = Targ_FindNode(".END", TARG_CREATE);
        /*
         * If the user has defined a .BEGIN target, execute the commands
         * attached to it.
        */
        if (!queryFlag) {
                gn = Targ_FindNode(".BEGIN", TARG_NOCREATE);
                if (gn != NULL) {
                        LST_FOREACH(ln, &gn->commands) {
                                if (Compat_RunCommand(Lst_Datum(ln), gn))
                                        break;
                        }
                        if (gn->made == ERROR) {
                                printf("\n\nStop.\n");
                                exit(1);
                        }
                }
        }

        /*
         * For each entry in the list of targets to create, call CompatMake on
         * it to create the thing. CompatMake will leave the 'made' field of gn
         * in one of several states:
         *      UPTODATE  gn was already up-to-date
         *      MADE      gn was recreated successfully
         *      ERROR     An error occurred while gn was being created
         *      ABORTED   gn was not remade because one of its inferiors
         *                could not be made due to errors.
         */
        error_cnt = 0;
        while (!Lst_IsEmpty(targs)) {
                gn = Lst_DeQueue(targs);
                CompatMake(gn, gn);

                if (gn->made == UPTODATE) {
                        printf("`%s' is up to date.\n", gn->name);
                } else if (gn->made == ABORTED) {
                        printf("`%s' not remade because of errors.\n",
                            gn->name);
                        error_cnt += 1;
                }
        }

        /*
         * If the user has defined a .END target, run its commands.
         */
        if (error_cnt == 0) {
                LST_FOREACH(ln, &ENDNode->commands) {
                        if (Compat_RunCommand(Lst_Datum(ln), gn))
                                break;
                }
        }
}