Sync usage with man page.

[netbsd-mini2440.git] / usr.bin / make / main.c

/*      $NetBSD: main.c,v 1.174 2009/09/09 17:09:49 sjg Exp $   */

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

/*
 * Copyright (c) 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.
 */

#ifndef MAKE_NATIVE
static char rcsid[] = "$NetBSD: main.c,v 1.174 2009/09/09 17:09:49 sjg Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1990, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)main.c      8.3 (Berkeley) 3/19/94";
#else
__RCSID("$NetBSD: main.c,v 1.174 2009/09/09 17:09:49 sjg Exp $");
#endif
#endif /* not lint */
#endif

/*-
 * main.c --
 *      The main file for this entire program. Exit routines etc
 *      reside here.
 *
 * Utility functions defined in this file:
 *      Main_ParseArgLine       Takes a line of arguments, breaks them and
 *                              treats them as if they were given when first
 *                              invoked. Used by the parse module to implement
 *                              the .MFLAGS target.
 *
 *      Error                   Print a tagged error message. The global
 *                              MAKE variable must have been defined. This
 *                              takes a format string and two optional
 *                              arguments for it.
 *
 *      Fatal                   Print an error message and exit. Also takes
 *                              a format string and two arguments.
 *
 *      Punt                    Aborts all jobs and exits with a message. Also
 *                              takes a format string and two arguments.
 *
 *      Finish                  Finish things up by printing the number of
 *                              errors which occurred, as passed to it, and
 *                              exiting.
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/signal.h>
#include <sys/stat.h>
#ifdef MAKE_NATIVE
#include <sys/utsname.h>
#endif
#include <sys/wait.h>

#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#include "make.h"
#include "hash.h"
#include "dir.h"
#include "job.h"
#include "pathnames.h"
#include "trace.h"

#ifdef USE_IOVEC
#include <sys/uio.h>
#endif

#ifndef DEFMAXLOCAL
#define DEFMAXLOCAL DEFMAXJOBS
#endif  /* DEFMAXLOCAL */

Lst                     create;         /* Targets to be made */
time_t                  now;            /* Time at start of make */
GNode                   *DEFAULT;       /* .DEFAULT node */
Boolean                 allPrecious;    /* .PRECIOUS given on line by itself */

static Boolean          noBuiltins;     /* -r flag */
static Lst              makefiles;      /* ordered list of makefiles to read */
static Boolean          printVars;      /* print value of one or more vars */
static Lst              variables;      /* list of variables to print */
int                     maxJobs;        /* -j argument */
static int              maxJobTokens;   /* -j argument */
Boolean                 compatMake;     /* -B argument */
int                     debug;          /* -d argument */
Boolean                 noExecute;      /* -n flag */
Boolean                 noRecursiveExecute;     /* -N flag */
Boolean                 keepgoing;      /* -k flag */
Boolean                 queryFlag;      /* -q flag */
Boolean                 touchFlag;      /* -t flag */
Boolean                 ignoreErrors;   /* -i flag */
Boolean                 beSilent;       /* -s flag */
Boolean                 oldVars;        /* variable substitution style */
Boolean                 checkEnvFirst;  /* -e flag */
Boolean                 parseWarnFatal; /* -W flag */
Boolean                 jobServer;      /* -J flag */
static int jp_0 = -1, jp_1 = -1;        /* ends of parent job pipe */
Boolean                 varNoExportEnv; /* -X flag */
Boolean                 doing_depend;   /* Set while reading .depend */
static Boolean          jobsRunning;    /* TRUE if the jobs might be running */
static const char *     tracefile;
static char *           Check_Cwd_av(int, char **, int);
static void             MainParseArgs(int, char **);
static int              ReadMakefile(const void *, const void *);
static void             usage(void);

static Boolean          ignorePWD;      /* if we use -C, PWD is meaningless */
static char curdir[MAXPATHLEN + 1];     /* startup directory */
static char objdir[MAXPATHLEN + 1];     /* where we chdir'ed to */
char *progname;                         /* the program name */

Boolean forceJobs = FALSE;

extern Lst parseIncPath;

static void
parse_debug_options(const char *argvalue)
{
        const char *modules;
        const char *mode;
        char *fname;
        int len;

        for (modules = argvalue; *modules; ++modules) {
                switch (*modules) {
                case 'A':
                        debug = ~0;
                        break;
                case 'a':
                        debug |= DEBUG_ARCH;
                        break;
                case 'C':
                        debug |= DEBUG_CWD;
                        break;
                case 'c':
                        debug |= DEBUG_COND;
                        break;
                case 'd':
                        debug |= DEBUG_DIR;
                        break;
                case 'e':
                        debug |= DEBUG_ERROR;
                        break;
                case 'f':
                        debug |= DEBUG_FOR;
                        break;
                case 'g':
                        if (modules[1] == '1') {
                                debug |= DEBUG_GRAPH1;
                                ++modules;
                        }
                        else if (modules[1] == '2') {
                                debug |= DEBUG_GRAPH2;
                                ++modules;
                        }
                        else if (modules[1] == '3') {
                                debug |= DEBUG_GRAPH3;
                                ++modules;
                        }
                        break;
                case 'j':
                        debug |= DEBUG_JOB;
                        break;
                case 'l':
                        debug |= DEBUG_LOUD;
                        break;
                case 'm':
                        debug |= DEBUG_MAKE;
                        break;
                case 'n':
                        debug |= DEBUG_SCRIPT;
                        break;
                case 'p':
                        debug |= DEBUG_PARSE;
                        break;
                case 's':
                        debug |= DEBUG_SUFF;
                        break;
                case 't':
                        debug |= DEBUG_TARG;
                        break;
                case 'v':
                        debug |= DEBUG_VAR;
                        break;
                case 'x':
                        debug |= DEBUG_SHELL;
                        break;
                case 'F':
                        if (debug_file != stdout && debug_file != stderr)
                                fclose(debug_file);
                        if (*++modules == '+')
                                mode = "a";
                        else
                                mode = "w";
                        if (strcmp(modules, "stdout") == 0) {
                                debug_file = stdout;
                                goto debug_setbuf;
                        }
                        if (strcmp(modules, "stderr") == 0) {
                                debug_file = stderr;
                                goto debug_setbuf;
                        }
                        len = strlen(modules);
                        fname = malloc(len + 20);
                        memcpy(fname, modules, len + 1);
                        /* Let the filename be modified by the pid */
                        if (strcmp(fname + len - 3, ".%d") == 0)
                                snprintf(fname + len - 2, 20, "%d", getpid());
                        debug_file = fopen(fname, mode);
                        if (!debug_file) {
                                fprintf(stderr, "Cannot open debug file %s\n",
                                    fname);
                                usage();
                        }
                        free(fname);
                        goto debug_setbuf;
                default:
                        (void)fprintf(stderr,
                            "%s: illegal argument to d option -- %c\n",
                            progname, *modules);
                        usage();
                }
        }
debug_setbuf:
        /*
         * Make the debug_file unbuffered, and make
         * stdout line buffered (unless debugfile == stdout).
         */
        setvbuf(debug_file, NULL, _IONBF, 0);
        if (debug_file != stdout) {
                setvbuf(stdout, NULL, _IOLBF, 0);
        }
}

/*-
 * MainParseArgs --
 *      Parse a given argument vector. Called from main() and from
 *      Main_ParseArgLine() when the .MAKEFLAGS target is used.
 *
 *      XXX: Deal with command line overriding .MAKEFLAGS in makefile
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Various global and local flags will be set depending on the flags
 *      given
 */
static void
MainParseArgs(int argc, char **argv)
{
        char *p;
        int c = '?';
        int arginc;
        char *argvalue;
        const char *getopt_def;
        char *optscan;
        Boolean inOption, dashDash = FALSE;
        char found_path[MAXPATHLEN + 1];        /* for searching for sys.mk */

#define OPTFLAGS "BC:D:I:J:NST:V:WXd:ef:ij:km:nqrst"
/* Can't actually use getopt(3) because rescanning is not portable */

        getopt_def = OPTFLAGS;
rearg:  
        inOption = FALSE;
        optscan = NULL;
        while(argc > 1) {
                char *getopt_spec;
                if(!inOption)
                        optscan = argv[1];
                c = *optscan++;
                arginc = 0;
                if(inOption) {
                        if(c == '\0') {
                                ++argv;
                                --argc;
                                inOption = FALSE;
                                continue;
                        }
                } else {
                        if (c != '-' || dashDash)
                                break;
                        inOption = TRUE;
                        c = *optscan++;
                }
                /* '-' found at some earlier point */
                getopt_spec = strchr(getopt_def, c);
                if(c != '\0' && getopt_spec != NULL && getopt_spec[1] == ':') {
                        /* -<something> found, and <something> should have an arg */
                        inOption = FALSE;
                        arginc = 1;
                        argvalue = optscan;
                        if(*argvalue == '\0') {
                                if (argc < 3)
                                        goto noarg;
                                argvalue = argv[2];
                                arginc = 2;
                        }
                } else {
                        argvalue = NULL; 
                }
                switch(c) {
                case '\0':
                        arginc = 1;
                        inOption = FALSE;
                        break;
                case 'B':
                        compatMake = TRUE;
                        Var_Append(MAKEFLAGS, "-B", VAR_GLOBAL);
                        break;
                case 'C':
                        if (chdir(argvalue) == -1) {
                                (void)fprintf(stderr,
                                              "%s: chdir %s: %s\n",
                                              progname, argvalue,
                                              strerror(errno));
                                exit(1);
                        }
                        if (getcwd(curdir, MAXPATHLEN) == NULL) {
                                (void)fprintf(stderr, "%s: %s.\n", progname, strerror(errno));
                                exit(2);
                        }
                        ignorePWD = TRUE;
                        break;
                case 'D':
                        if (argvalue == NULL || argvalue[0] == 0) goto noarg;
                        Var_Set(argvalue, "1", VAR_GLOBAL, 0);
                        Var_Append(MAKEFLAGS, "-D", VAR_GLOBAL);
                        Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        break;
                case 'I':
                        if (argvalue == NULL) goto noarg;
                        Parse_AddIncludeDir(argvalue);
                        Var_Append(MAKEFLAGS, "-I", VAR_GLOBAL);
                        Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        break;
                case 'J':
                        if (argvalue == NULL) goto noarg;
                        if (sscanf(argvalue, "%d,%d", &jp_0, &jp_1) != 2) {
                            (void)fprintf(stderr,
                                "%s: internal error -- J option malformed (%s)\n",
                                progname, argvalue);
                                usage();
                        }
                        if ((fcntl(jp_0, F_GETFD, 0) < 0) ||
                            (fcntl(jp_1, F_GETFD, 0) < 0)) {
#if 0
                            (void)fprintf(stderr,
                                "%s: ###### warning -- J descriptors were closed!\n",
                                progname);
                            exit(2);
#endif
                            jp_0 = -1;
                            jp_1 = -1;
                            compatMake = TRUE;
                        } else {
                            Var_Append(MAKEFLAGS, "-J", VAR_GLOBAL);
                            Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                            jobServer = TRUE;
                        }
                        break;
                case 'N':
                        noExecute = TRUE;
                        noRecursiveExecute = TRUE;
                        Var_Append(MAKEFLAGS, "-N", VAR_GLOBAL);
                        break;
                case 'S':
                        keepgoing = FALSE;
                        Var_Append(MAKEFLAGS, "-S", VAR_GLOBAL);
                        break;
                case 'T':
                        if (argvalue == NULL) goto noarg;
                        tracefile = bmake_strdup(argvalue);
                        Var_Append(MAKEFLAGS, "-T", VAR_GLOBAL);
                        Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        break;
                case 'V':
                        if (argvalue == NULL) goto noarg;
                        printVars = TRUE;
                        (void)Lst_AtEnd(variables, argvalue);
                        Var_Append(MAKEFLAGS, "-V", VAR_GLOBAL);
                        Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        break;
                case 'W':
                        parseWarnFatal = TRUE;
                        break;
                case 'X':
                        varNoExportEnv = TRUE;
                        Var_Append(MAKEFLAGS, "-X", VAR_GLOBAL);
                        break;
                case 'd':
                        if (argvalue == NULL) goto noarg;
                        /* If '-d-opts' don't pass to children */
                        if (argvalue[0] == '-')
                            argvalue++;
                        else {
                            Var_Append(MAKEFLAGS, "-d", VAR_GLOBAL);
                            Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        }
                        parse_debug_options(argvalue);
                        break;
                case 'e':
                        checkEnvFirst = TRUE;
                        Var_Append(MAKEFLAGS, "-e", VAR_GLOBAL);
                        break;
                case 'f':
                        if (argvalue == NULL) goto noarg;
                        (void)Lst_AtEnd(makefiles, argvalue);
                        break;
                case 'i':
                        ignoreErrors = TRUE;
                        Var_Append(MAKEFLAGS, "-i", VAR_GLOBAL);
                        break;
                case 'j':
                        if (argvalue == NULL) goto noarg;
                        forceJobs = TRUE;
                        maxJobs = strtol(argvalue, &p, 0);
                        if (*p != '\0' || maxJobs < 1) {
                                (void)fprintf(stderr, "%s: illegal argument to -j -- must be positive integer!\n",
                                    progname);
                                exit(1);
                        }
                        Var_Append(MAKEFLAGS, "-j", VAR_GLOBAL);
                        Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        maxJobTokens = maxJobs;
                        break;
                case 'k':
                        keepgoing = TRUE;
                        Var_Append(MAKEFLAGS, "-k", VAR_GLOBAL);
                        break;
                case 'm':
                        if (argvalue == NULL) goto noarg;
                        /* look for magic parent directory search string */
                        if (strncmp(".../", argvalue, 4) == 0) {
                                if (!Dir_FindHereOrAbove(curdir, argvalue+4,
                                    found_path, sizeof(found_path)))
                                        break;          /* nothing doing */
                                (void)Dir_AddDir(sysIncPath, found_path);
                        } else {
                                (void)Dir_AddDir(sysIncPath, argvalue);
                        }
                        Var_Append(MAKEFLAGS, "-m", VAR_GLOBAL);
                        Var_Append(MAKEFLAGS, argvalue, VAR_GLOBAL);
                        break;
                case 'n':
                        noExecute = TRUE;
                        Var_Append(MAKEFLAGS, "-n", VAR_GLOBAL);
                        break;
                case 'q':
                        queryFlag = TRUE;
                        /* Kind of nonsensical, wot? */
                        Var_Append(MAKEFLAGS, "-q", VAR_GLOBAL);
                        break;
                case 'r':
                        noBuiltins = TRUE;
                        Var_Append(MAKEFLAGS, "-r", VAR_GLOBAL);
                        break;
                case 's':
                        beSilent = TRUE;
                        Var_Append(MAKEFLAGS, "-s", VAR_GLOBAL);
                        break;
                case 't':
                        touchFlag = TRUE;
                        Var_Append(MAKEFLAGS, "-t", VAR_GLOBAL);
                        break;
                case '-':
                        dashDash = TRUE;
                        break;
                default:
                case '?':
                        usage();
                }
                argv += arginc;
                argc -= arginc;
        }

        oldVars = TRUE;

        /*
         * See if the rest of the arguments are variable assignments and
         * perform them if so. Else take them to be targets and stuff them
         * on the end of the "create" list.
         */
        for (; argc > 1; ++argv, --argc)
                if (Parse_IsVar(argv[1])) {
                        Parse_DoVar(argv[1], VAR_CMD);
                } else {
                        if (!*argv[1])
                                Punt("illegal (null) argument.");
                        if (*argv[1] == '-' && !dashDash)
                                goto rearg;
                        (void)Lst_AtEnd(create, bmake_strdup(argv[1]));
                }

        return;
noarg:
        (void)fprintf(stderr, "%s: option requires an argument -- %c\n",
            progname, c);
        usage();
}

/*-
 * Main_ParseArgLine --
 *      Used by the parse module when a .MFLAGS or .MAKEFLAGS target
 *      is encountered and by main() when reading the .MAKEFLAGS envariable.
 *      Takes a line of arguments and breaks it into its
 *      component words and passes those words and the number of them to the
 *      MainParseArgs function.
 *      The line should have all its leading whitespace removed.
 *
 * Input:
 *      line            Line to fracture
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Only those that come from the various arguments.
 */
void
Main_ParseArgLine(const char *line)
{
        char **argv;                    /* Manufactured argument vector */
        int argc;                       /* Number of arguments in argv */
        char *args;                     /* Space used by the args */
        char *buf, *p1;
        char *argv0 = Var_Value(".MAKE", VAR_GLOBAL, &p1);
        size_t len;

        if (line == NULL)
                return;
        for (; *line == ' '; ++line)
                continue;
        if (!*line)
                return;

        buf = bmake_malloc(len = strlen(line) + strlen(argv0) + 2);
        (void)snprintf(buf, len, "%s %s", argv0, line);
        if (p1)
                free(p1);

        argv = brk_string(buf, &argc, TRUE, &args);
        if (argv == NULL) {
                Error("Unterminated quoted string [%s]", buf);
                free(buf);
                return;
        }
        free(buf);
        MainParseArgs(argc, argv);

        free(args);
        free(argv);
}

Boolean
Main_SetObjdir(const char *path)
{
        struct stat sb;
        char *p = NULL;
        char buf[MAXPATHLEN + 1];
        Boolean rc = FALSE;

        /* expand variable substitutions */
        if (strchr(path, '$') != 0) {
                snprintf(buf, MAXPATHLEN, "%s", path);
                path = p = Var_Subst(NULL, buf, VAR_GLOBAL, 0);
        }

        if (path[0] != '/') {
                snprintf(buf, MAXPATHLEN, "%s/%s", curdir, path);
                path = buf;
        }

        /* look for the directory and try to chdir there */
        if (stat(path, &sb) == 0 && S_ISDIR(sb.st_mode)) {
                if (chdir(path)) {
                        (void)fprintf(stderr, "make warning: %s: %s.\n",
                                      path, strerror(errno));
                } else {
                        strncpy(objdir, path, MAXPATHLEN);
                        Var_Set(".OBJDIR", objdir, VAR_GLOBAL, 0);
                        setenv("PWD", objdir, 1);
                        Dir_InitDot();
                        rc = TRUE;
                }
        }

        if (p)
                free(p);
        return rc;
}

/*-
 * ReadAllMakefiles --
 *      wrapper around ReadMakefile() to read all.
 *
 * Results:
 *      TRUE if ok, FALSE on error
 */
static int
ReadAllMakefiles(const void *p, const void *q)
{
        return (ReadMakefile(p, q) == 0);
}

#ifdef SIGINFO
/*ARGSUSED*/
static void
siginfo(int signo)
{
        char dir[MAXPATHLEN];
        char str[2 * MAXPATHLEN];
        int len;
        if (getcwd(dir, sizeof(dir)) == NULL)
                return;
        len = snprintf(str, sizeof(str), "%s: Working in: %s\n", progname, dir);
        if (len > 0)
                (void)write(STDERR_FILENO, str, (size_t)len);
}
#endif

/*-
 * main --
 *      The main function, for obvious reasons. Initializes variables
 *      and a few modules, then parses the arguments give it in the
 *      environment and on the command line. Reads the system makefile
 *      followed by either Makefile, makefile or the file given by the
 *      -f argument. Sets the .MAKEFLAGS PMake variable based on all the
 *      flags it has received by then uses either the Make or the Compat
 *      module to create the initial list of targets.
 *
 * Results:
 *      If -q was given, exits -1 if anything was out-of-date. Else it exits
 *      0.
 *
 * Side Effects:
 *      The program exits when done. Targets are created. etc. etc. etc.
 */
int
main(int argc, char **argv)
{
        Lst targs;      /* target nodes to create -- passed to Make_Init */
        Boolean outOfDate = FALSE;      /* FALSE if all targets up to date */
        struct stat sb, sa;
        char *p1, *path, *pwd;
        char mdpath[MAXPATHLEN];
        char *machine = getenv("MACHINE");
        const char *machine_arch = getenv("MACHINE_ARCH");
        char *syspath = getenv("MAKESYSPATH");
        Lst sysMkPath;                  /* Path of sys.mk */
        char *cp = NULL, *start;
                                        /* avoid faults on read-only strings */
        static char defsyspath[] = _PATH_DEFSYSPATH;
        char found_path[MAXPATHLEN + 1];        /* for searching for sys.mk */
        struct timeval rightnow;                /* to initialize random seed */
#ifdef MAKE_NATIVE
        struct utsname utsname;
#endif

        /* default to writing debug to stderr */
        debug_file = stderr;

#ifdef SIGINFO
        (void)signal(SIGINFO, siginfo);
#endif
        /*
         * Set the seed to produce a different random sequence
         * on each program execution.
         */
        gettimeofday(&rightnow, NULL);
        srandom(rightnow.tv_sec + rightnow.tv_usec);
        
        if ((progname = strrchr(argv[0], '/')) != NULL)
                progname++;
        else
                progname = argv[0];
#ifdef RLIMIT_NOFILE
        /*
         * get rid of resource limit on file descriptors
         */
        {
                struct rlimit rl;
                if (getrlimit(RLIMIT_NOFILE, &rl) != -1 &&
                    rl.rlim_cur != rl.rlim_max) {
                        rl.rlim_cur = rl.rlim_max;
                        (void)setrlimit(RLIMIT_NOFILE, &rl);
                }
        }
#endif

        /*
         * Get the name of this type of MACHINE from utsname
         * so we can share an executable for similar machines.
         * (i.e. m68k: amiga hp300, mac68k, sun3, ...)
         *
         * Note that both MACHINE and MACHINE_ARCH are decided at
         * run-time.
         */
        if (!machine) {
#ifdef MAKE_NATIVE
            if (uname(&utsname) == -1) {
                (void)fprintf(stderr, "%s: uname failed (%s).\n", progname,
                    strerror(errno));
                exit(2);
            }
            machine = utsname.machine;
#else
#ifdef MAKE_MACHINE
            machine = MAKE_MACHINE;
#else
            machine = "unknown";
#endif
#endif
        }

        if (!machine_arch) {
#ifndef MACHINE_ARCH
#ifdef MAKE_MACHINE_ARCH
            machine_arch = MAKE_MACHINE_ARCH;
#else
            machine_arch = "unknown";
#endif
#else
            machine_arch = MACHINE_ARCH;
#endif
        }

        /*
         * Just in case MAKEOBJDIR wants us to do something tricky.
         */
        Var_Init();             /* Initialize the lists of variables for
                                 * parsing arguments */
        Var_Set("MACHINE", machine, VAR_GLOBAL, 0);
        Var_Set("MACHINE_ARCH", machine_arch, VAR_GLOBAL, 0);
#ifdef MAKE_VERSION
        Var_Set("MAKE_VERSION", MAKE_VERSION, VAR_GLOBAL, 0);
#endif
        Var_Set(".newline", "\n", VAR_GLOBAL, 0); /* handy for :@ loops */

        create = Lst_Init(FALSE);
        makefiles = Lst_Init(FALSE);
        printVars = FALSE;
        variables = Lst_Init(FALSE);
        beSilent = FALSE;               /* Print commands as executed */
        ignoreErrors = FALSE;           /* Pay attention to non-zero returns */
        noExecute = FALSE;              /* Execute all commands */
        noRecursiveExecute = FALSE;     /* Execute all .MAKE targets */
        keepgoing = FALSE;              /* Stop on error */
        allPrecious = FALSE;            /* Remove targets when interrupted */
        queryFlag = FALSE;              /* This is not just a check-run */
        noBuiltins = FALSE;             /* Read the built-in rules */
        touchFlag = FALSE;              /* Actually update targets */
        debug = 0;                      /* No debug verbosity, please. */
        jobsRunning = FALSE;

        maxJobs = DEFMAXLOCAL;          /* Set default local max concurrency */
        maxJobTokens = maxJobs;
        compatMake = FALSE;             /* No compat mode */
        ignorePWD = FALSE;

        /*
         * Initialize the parsing, directory and variable modules to prepare
         * for the reading of inclusion paths and variable settings on the
         * command line
         */

        /*
         * Initialize various variables.
         *      MAKE also gets this name, for compatibility
         *      .MAKEFLAGS gets set to the empty string just in case.
         *      MFLAGS also gets initialized empty, for compatibility.
         */
        Parse_Init();
        Var_Set("MAKE", argv[0], VAR_GLOBAL, 0);
        Var_Set(".MAKE", argv[0], VAR_GLOBAL, 0);
        Var_Set(MAKEFLAGS, "", VAR_GLOBAL, 0);
        Var_Set(MAKEOVERRIDES, "", VAR_GLOBAL, 0);
        Var_Set("MFLAGS", "", VAR_GLOBAL, 0);
        Var_Set(".ALLTARGETS", "", VAR_GLOBAL, 0);

        /*
         * Set some other useful macros
         */
        {
            char tmp[64];
            const char *ep;

            if (!(ep = getenv(MAKE_LEVEL))) {
                ep = "0";
            }
            Var_Set(MAKE_LEVEL, ep, VAR_GLOBAL, 0);
            snprintf(tmp, sizeof(tmp), "%u", getpid());
            Var_Set(".MAKE.PID", tmp, VAR_GLOBAL, 0);
            snprintf(tmp, sizeof(tmp), "%u", getppid());
            Var_Set(".MAKE.PPID", tmp, VAR_GLOBAL, 0);
        }
        Job_SetPrefix();

        /*
         * First snag any flags out of the MAKE environment variable.
         * (Note this is *not* MAKEFLAGS since /bin/make uses that and it's
         * in a different format).
         */
#ifdef POSIX
        Main_ParseArgLine(getenv("MAKEFLAGS"));
#else
        Main_ParseArgLine(getenv("MAKE"));
#endif

        /*
         * Find where we are (now).
         * We take care of PWD for the automounter below...
         */
        if (getcwd(curdir, MAXPATHLEN) == NULL) {
                (void)fprintf(stderr, "%s: %s.\n", progname, strerror(errno));
                exit(2);
        }

        MainParseArgs(argc, argv);

        /*
         * Verify that cwd is sane.
         */
        if (stat(curdir, &sa) == -1) {
            (void)fprintf(stderr, "%s: %s: %s.\n",
                 progname, curdir, strerror(errno));
            exit(2);
        }

        /*
         * All this code is so that we know where we are when we start up
         * on a different machine with pmake.
         * Overriding getcwd() with $PWD totally breaks MAKEOBJDIRPREFIX
         * since the value of curdir can vary depending on how we got
         * here.  Ie sitting at a shell prompt (shell that provides $PWD)
         * or via subdir.mk in which case its likely a shell which does
         * not provide it.
         * So, to stop it breaking this case only, we ignore PWD if
         * MAKEOBJDIRPREFIX is set or MAKEOBJDIR contains a transform.
         */
        if (!ignorePWD &&
            (pwd = getenv("PWD")) != NULL &&
            getenv("MAKEOBJDIRPREFIX") == NULL) {
                const char *makeobjdir = getenv("MAKEOBJDIR");

                if (makeobjdir == NULL || !strchr(makeobjdir, '$')) {
                        if (stat(pwd, &sb) == 0 && sa.st_ino == sb.st_ino &&
                            sa.st_dev == sb.st_dev)
                                (void)strncpy(curdir, pwd, MAXPATHLEN);
                }
        }
        Var_Set(".CURDIR", curdir, VAR_GLOBAL, 0);

        /*
         * Find the .OBJDIR.  If MAKEOBJDIRPREFIX, or failing that,
         * MAKEOBJDIR is set in the environment, try only that value
         * and fall back to .CURDIR if it does not exist.
         *
         * Otherwise, try _PATH_OBJDIR.MACHINE, _PATH_OBJDIR, and
         * finally _PATH_OBJDIRPREFIX`pwd`, in that order.  If none
         * of these paths exist, just use .CURDIR.
         */
        Dir_Init(curdir);
        (void)Main_SetObjdir(curdir);

        if ((path = getenv("MAKEOBJDIRPREFIX")) != NULL) {
                (void)snprintf(mdpath, MAXPATHLEN, "%s%s", path, curdir);
                (void)Main_SetObjdir(mdpath);
        } else if ((path = getenv("MAKEOBJDIR")) != NULL) {
                (void)Main_SetObjdir(path);
        } else {
                (void)snprintf(mdpath, MAXPATHLEN, "%s.%s", _PATH_OBJDIR, machine);
                if (!Main_SetObjdir(mdpath) && !Main_SetObjdir(_PATH_OBJDIR)) {
                        (void)snprintf(mdpath, MAXPATHLEN, "%s%s", 
                                        _PATH_OBJDIRPREFIX, curdir);
                        (void)Main_SetObjdir(mdpath);
                }
        }

        /*
         * Be compatible if user did not specify -j and did not explicitly
         * turned compatibility on
         */
        if (!compatMake && !forceJobs) {
                compatMake = TRUE;
        }
        
        /*
         * Initialize archive, target and suffix modules in preparation for
         * parsing the makefile(s)
         */
        Arch_Init();
        Targ_Init();
        Suff_Init();
        Trace_Init(tracefile);

        DEFAULT = NULL;
        (void)time(&now);

        Trace_Log(MAKESTART, NULL);
        
        /*
         * Set up the .TARGETS variable to contain the list of targets to be
         * created. If none specified, make the variable empty -- the parser
         * will fill the thing in with the default or .MAIN target.
         */
        if (!Lst_IsEmpty(create)) {
                LstNode ln;

                for (ln = Lst_First(create); ln != NULL;
                    ln = Lst_Succ(ln)) {
                        char *name = (char *)Lst_Datum(ln);

                        Var_Append(".TARGETS", name, VAR_GLOBAL);
                }
        } else
                Var_Set(".TARGETS", "", VAR_GLOBAL, 0);


        /*
         * If no user-supplied system path was given (through the -m option)
         * add the directories from the DEFSYSPATH (more than one may be given
         * as dir1:...:dirn) to the system include path.
         */
        if (syspath == NULL || *syspath == '\0')
                syspath = defsyspath;
        else
                syspath = bmake_strdup(syspath);

        for (start = syspath; *start != '\0'; start = cp) {
                for (cp = start; *cp != '\0' && *cp != ':'; cp++)
                        continue;
                if (*cp == ':') {
                        *cp++ = '\0';
                }
                /* look for magic parent directory search string */
                if (strncmp(".../", start, 4) != 0) {
                        (void)Dir_AddDir(defIncPath, start);
                } else {
                        if (Dir_FindHereOrAbove(curdir, start+4, 
                            found_path, sizeof(found_path))) {
                                (void)Dir_AddDir(defIncPath, found_path);
                        }
                }
        }
        if (syspath != defsyspath)
                free(syspath);

        /*
         * Read in the built-in rules first, followed by the specified
         * makefile, if it was (makefile != NULL), or the default
         * makefile and Makefile, in that order, if it wasn't.
         */
        if (!noBuiltins) {
                LstNode ln;

                sysMkPath = Lst_Init(FALSE);
                Dir_Expand(_PATH_DEFSYSMK,
                           Lst_IsEmpty(sysIncPath) ? defIncPath : sysIncPath,
                           sysMkPath);
                if (Lst_IsEmpty(sysMkPath))
                        Fatal("%s: no system rules (%s).", progname,
                            _PATH_DEFSYSMK);
                ln = Lst_Find(sysMkPath, NULL, ReadMakefile);
                if (ln == NULL)
                        Fatal("%s: cannot open %s.", progname,
                            (char *)Lst_Datum(ln));
        }

        if (!Lst_IsEmpty(makefiles)) {
                LstNode ln;

                ln = Lst_Find(makefiles, NULL, ReadAllMakefiles);
                if (ln != NULL)
                        Fatal("%s: cannot open %s.", progname, 
                            (char *)Lst_Datum(ln));
        } else if (ReadMakefile("makefile", NULL) != 0)
                (void)ReadMakefile("Makefile", NULL);

        /* In particular suppress .depend for '-r -V .OBJDIR -f /dev/null' */
        if (!noBuiltins || !printVars) {
                doing_depend = TRUE;
                (void)ReadMakefile(".depend", NULL);
                doing_depend = FALSE;
        }

        Var_Append("MFLAGS", Var_Value(MAKEFLAGS, VAR_GLOBAL, &p1), VAR_GLOBAL);
        if (p1)
            free(p1);

        if (!compatMake)
            Job_ServerStart(maxJobTokens, jp_0, jp_1);
        if (DEBUG(JOB))
            fprintf(debug_file, "job_pipe %d %d, maxjobs %d, tokens %d, compat %d\n",
                jp_0, jp_1, maxJobs, maxJobTokens, compatMake);

        Main_ExportMAKEFLAGS(TRUE);     /* initial export */

        Check_Cwd_av(0, NULL, 0);       /* initialize it */
        

        /*
         * For compatibility, look at the directories in the VPATH variable
         * and add them to the search path, if the variable is defined. The
         * variable's value is in the same format as the PATH envariable, i.e.
         * <directory>:<directory>:<directory>...
         */
        if (Var_Exists("VPATH", VAR_CMD)) {
                char *vpath, savec;
                /*
                 * GCC stores string constants in read-only memory, but
                 * Var_Subst will want to write this thing, so store it
                 * in an array
                 */
                static char VPATH[] = "${VPATH}";

                vpath = Var_Subst(NULL, VPATH, VAR_CMD, FALSE);
                path = vpath;
                do {
                        /* skip to end of directory */
                        for (cp = path; *cp != ':' && *cp != '\0'; cp++)
                                continue;
                        /* Save terminator character so know when to stop */
                        savec = *cp;
                        *cp = '\0';
                        /* Add directory to search path */
                        (void)Dir_AddDir(dirSearchPath, path);
                        *cp = savec;
                        path = cp + 1;
                } while (savec == ':');
                free(vpath);
        }

        /*
         * Now that all search paths have been read for suffixes et al, it's
         * time to add the default search path to their lists...
         */
        Suff_DoPaths();

        /*
         * Propagate attributes through :: dependency lists.
         */
        Targ_Propagate();

        /* print the initial graph, if the user requested it */
        if (DEBUG(GRAPH1))
                Targ_PrintGraph(1);

        /* print the values of any variables requested by the user */
        if (printVars) {
                LstNode ln;

                for (ln = Lst_First(variables); ln != NULL;
                    ln = Lst_Succ(ln)) {
                        char *var = (char *)Lst_Datum(ln);
                        char *value;
                        
                        if (strchr(var, '$')) {
                                value = p1 = Var_Subst(NULL, var, VAR_GLOBAL, 0);
                        } else {
                                value = Var_Value(var, VAR_GLOBAL, &p1);
                        }
                        printf("%s\n", value ? value : "");
                        if (p1)
                                free(p1);
                }
        } else {
                /*
                 * Have now read the entire graph and need to make a list of
                 * targets to create. If none was given on the command line,
                 * we consult the parsing module to find the main target(s)
                 * to create.
                 */
                if (Lst_IsEmpty(create))
                        targs = Parse_MainName();
                else
                        targs = Targ_FindList(create, TARG_CREATE);

                if (!compatMake) {
                        /*
                         * Initialize job module before traversing the graph
                         * now that any .BEGIN and .END targets have been read.
                         * This is done only if the -q flag wasn't given
                         * (to prevent the .BEGIN from being executed should
                         * it exist).
                         */
                        if (!queryFlag) {
                                Job_Init();
                                jobsRunning = TRUE;
                        }

                        /* Traverse the graph, checking on all the targets */
                        outOfDate = Make_Run(targs);
                } else {
                        /*
                         * Compat_Init will take care of creating all the
                         * targets as well as initializing the module.
                         */
                        Compat_Run(targs);
                }
        }

#ifdef CLEANUP
        Lst_Destroy(targs, NULL);
        Lst_Destroy(variables, NULL);
        Lst_Destroy(makefiles, NULL);
        Lst_Destroy(create, (FreeProc *)free);
#endif

        /* print the graph now it's been processed if the user requested it */
        if (DEBUG(GRAPH2))
                Targ_PrintGraph(2);

        Trace_Log(MAKEEND, 0);

        Suff_End();
        Targ_End();
        Arch_End();
        Var_End();
        Parse_End();
        Dir_End();
        Job_End();
        Trace_End();

        return outOfDate ? 1 : 0;
}

/*-
 * ReadMakefile  --
 *      Open and parse the given makefile.
 *
 * Results:
 *      0 if ok. -1 if couldn't open file.
 *
 * Side Effects:
 *      lots
 */
static int
ReadMakefile(const void *p, const void *q __unused)
{
        const char *fname = p;          /* makefile to read */
        int fd;
        size_t len = MAXPATHLEN;
        char *name, *path = bmake_malloc(len);
        int setMAKEFILE;

        if (!strcmp(fname, "-")) {
                Parse_File("(stdin)", dup(fileno(stdin)));
                Var_Set("MAKEFILE", "", VAR_GLOBAL, 0);
        } else {
                setMAKEFILE = strcmp(fname, ".depend");

                /* if we've chdir'd, rebuild the path name */
                if (strcmp(curdir, objdir) && *fname != '/') {
                        size_t plen = strlen(curdir) + strlen(fname) + 2;
                        if (len < plen)
                                path = bmake_realloc(path, len = 2 * plen);
                        
                        (void)snprintf(path, len, "%s/%s", curdir, fname);
                        fd = open(path, O_RDONLY);
                        if (fd != -1) {
                                fname = path;
                                goto found;
                        }
                        
                        /* If curdir failed, try objdir (ala .depend) */
                        plen = strlen(objdir) + strlen(fname) + 2;
                        if (len < plen)
                                path = bmake_realloc(path, len = 2 * plen);
                        (void)snprintf(path, len, "%s/%s", objdir, fname);
                        fd = open(path, O_RDONLY);
                        if (fd != -1) {
                                fname = path;
                                goto found;
                        }
                } else {
                        fd = open(fname, O_RDONLY);
                        if (fd != -1)
                                goto found;
                }
                /* look in -I and system include directories. */
                name = Dir_FindFile(fname, parseIncPath);
                if (!name)
                        name = Dir_FindFile(fname,
                                Lst_IsEmpty(sysIncPath) ? defIncPath : sysIncPath);
                if (!name || (fd = open(name, O_RDONLY)) == -1) {
                        if (name)
                                free(name);
                        free(path);
                        return(-1);
                }
                fname = name;
                /*
                 * set the MAKEFILE variable desired by System V fans -- the
                 * placement of the setting here means it gets set to the last
                 * makefile specified, as it is set by SysV make.
                 */
found:
                if (setMAKEFILE)
                        Var_Set("MAKEFILE", fname, VAR_GLOBAL, 0);
                Parse_File(fname, fd);
        }
        free(path);
        return(0);
}


/*
 * If MAKEOBJDIRPREFIX is in use, make ends up not in .CURDIR
 * in situations that would not arrise with ./obj (links or not).
 * This tends to break things like:
 *
 * build:
 *      ${MAKE} includes
 *
 * This function spots when ${.MAKE:T} or ${.MAKE} is a command (as
 * opposed to an argument) in a command line and if so returns
 * ${.CURDIR} so caller can chdir() so that the assumptions made by
 * the Makefile hold true.
 *
 * If ${.MAKE} does not contain any '/', then ${.MAKE:T} is skipped.
 *
 * The chdir() only happens in the child process, and does nothing if
 * MAKEOBJDIRPREFIX and MAKEOBJDIR are not in the environment so it
 * should not break anything.  Also if NOCHECKMAKECHDIR is set we
 * do nothing - to ensure historic semantics can be retained.
 */
static int  Check_Cwd_Off = 0;

static char *
Check_Cwd_av(int ac, char **av, int copy)
{
    static char *make[4];
    static char *cur_dir = NULL;
    char **mp;
    char *cp;
    int is_cmd, next_cmd;
    int i;
    int n;

    if (Check_Cwd_Off) {
        if (DEBUG(CWD))
            fprintf(debug_file, "check_cwd: check is off.\n");
        return NULL;
    }
    
    if (make[0] == NULL) {
        if (Var_Exists("NOCHECKMAKECHDIR", VAR_GLOBAL)) {
            Check_Cwd_Off = 1;
            if (DEBUG(CWD))
                fprintf(debug_file, "check_cwd: turning check off.\n");
            return NULL;
        }
            
        make[1] = Var_Value(".MAKE", VAR_GLOBAL, &cp);
        if ((make[0] = strrchr(make[1], '/')) == NULL) {
            make[0] = make[1];
            make[1] = NULL;
        } else
            ++make[0];
        make[2] = NULL;
        cur_dir = Var_Value(".CURDIR", VAR_GLOBAL, &cp);
    }
    if (ac == 0 || av == NULL) {
        if (DEBUG(CWD))
            fprintf(debug_file, "check_cwd: empty command.\n");
        return NULL;                    /* initialization only */
    }

    if (getenv("MAKEOBJDIR") == NULL &&
        getenv("MAKEOBJDIRPREFIX") == NULL) {
        if (DEBUG(CWD))
            fprintf(debug_file, "check_cwd: no obj dirs.\n");
        return NULL;
    }

    
    next_cmd = 1;
    for (i = 0; i < ac; ++i) {
        is_cmd = next_cmd;

        n = strlen(av[i]);
        cp = &(av[i])[n - 1];
        if (strspn(av[i], "|&;") == (size_t)n) {
            next_cmd = 1;
            continue;
        } else if (*cp == ';' || *cp == '&' || *cp == '|' || *cp == ')') {
            next_cmd = 1;
            if (copy) {
                do {
                    *cp-- = '\0';
                } while (*cp == ';' || *cp == '&' || *cp == '|' ||
                         *cp == ')' || *cp == '}') ;
            } else {
                /*
                 * XXX this should not happen.
                 */
                fprintf(stderr, "%s: WARNING: raw arg ends in shell meta '%s'\n",
                    progname, av[i]);
            }
        } else
            next_cmd = 0;

        cp = av[i];
        if (*cp == ';' || *cp == '&' || *cp == '|')
            is_cmd = 1;
        
        if (DEBUG(CWD))
            fprintf(debug_file, "av[%d] == %s '%s'",
                i, (is_cmd) ? "cmd" : "arg", av[i]);
        if (is_cmd != 0) {
            if (*cp == '(' || *cp == '{' ||
                *cp == ';' || *cp == '&' || *cp == '|') {
                do {
                    ++cp;
                } while (*cp == '(' || *cp == '{' ||
                         *cp == ';' || *cp == '&' || *cp == '|');
                if (*cp == '\0') {
                    next_cmd = 1;
                    continue;
                }
            }
            if (strcmp(cp, "cd") == 0 || strcmp(cp, "chdir") == 0) {
                if (DEBUG(CWD))
                    fprintf(debug_file, " == cd, done.\n");
                return NULL;
            }
            for (mp = make; *mp != NULL; ++mp) {
                n = strlen(*mp);
                if (strcmp(cp, *mp) == 0) {
                    if (DEBUG(CWD))
                        fprintf(debug_file, " %s == '%s', chdir(%s)\n",
                            cp, *mp, cur_dir);
                    return cur_dir;
                }
            }
        }
        if (DEBUG(CWD))
            fprintf(debug_file, "\n");
    }
    return NULL;
}

char *
Check_Cwd_Cmd(const char *cmd)
{
    char *cp, *bp;
    char **av;
    int ac;

    if (Check_Cwd_Off)
        return NULL;
    
    if (cmd) {
        av = brk_string(cmd, &ac, TRUE, &bp);
        if (DEBUG(CWD))
            fprintf(debug_file, "splitting: '%s' -> %d words\n",
                cmd, ac);
    } else {
        ac = 0;
        av = NULL;
        bp = NULL;
    }
    cp = Check_Cwd_av(ac, av, 1);
    if (bp)
        free(bp);
    if (av)
        free(av);
    return cp;
}

void
Check_Cwd(const char **argv)
{
    char *cp;
    int ac;
    
    if (Check_Cwd_Off)
        return;
    
    for (ac = 0; argv[ac] != NULL; ++ac)
        /* NOTHING */;
    if (ac == 3 && *argv[1] == '-') {
        cp =  Check_Cwd_Cmd(argv[2]);
    } else {
        cp = Check_Cwd_av(ac, UNCONST(argv), 0);
    }
    if (cp) {
        chdir(cp);
    }
}

/*-
 * 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 errnum is not NULL, it contains the reason for the command failure
 *
 * Side Effects:
 *      The string must be freed by the caller.
 */
char *
Cmd_Exec(const char *cmd, const char **errnum)
{
    const char  *args[4];       /* Args for invoking the shell */
    int         fds[2];         /* Pipe streams */
    int         cpid;           /* Child PID */
    int         pid;            /* PID from wait() */
    char        *res;           /* result */
    int         status;         /* command exit status */
    Buffer      buf;            /* buffer to store the result */
    char        *cp;
    int         cc;


    *errnum = NULL;

    if (!shellName)
        Shell_Init();
    /*
     * Set up arguments for shell
     */
    args[0] = shellName;
    args[1] = "-c";
    args[2] = cmd;
    args[3] = NULL;

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

    /*
     * Fork
     */
    switch (cpid = vfork()) {
    case 0:
        /*
         * Close input side of pipe
         */
        (void)close(fds[0]);

        /*
         * Duplicate the output stream to the shell's output, then
         * shut the extra thing down. Note we don't fetch the error
         * stream...why not? Why?
         */
        (void)dup2(fds[1], 1);
        (void)close(fds[1]);

        Var_ExportVars();

        (void)execv(shellPath, UNCONST(args));
        _exit(1);
        /*NOTREACHED*/

    case -1:
        *errnum = "Couldn't exec \"%s\"";
        goto bad;

    default:
        /*
         * No need for the writing half
         */
        (void)close(fds[1]);

        Buf_Init(&buf, 0);

        do {
            char   result[BUFSIZ];
            cc = read(fds[0], result, sizeof(result));
            if (cc > 0)
                Buf_AddBytes(&buf, cc, result);
        }
        while (cc > 0 || (cc == -1 && errno == EINTR));

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

        /*
         * Wait for the process to exit.
         */
        while(((pid = waitpid(cpid, &status, 0)) != cpid) && (pid >= 0))
            continue;

        cc = Buf_Size(&buf);
        res = Buf_Destroy(&buf, FALSE);

        if (cc == 0)
            *errnum = "Couldn't read shell's output for \"%s\"";

        if (WIFSIGNALED(status))
            *errnum = "\"%s\" exited on a signal";
        else if (WEXITSTATUS(status) != 0)
            *errnum = "\"%s\" returned non-zero status";

        /*
         * Null-terminate the result, convert newlines to spaces and
         * install it in the variable.
         */
        res[cc] = '\0';
        cp = &res[cc];

        if (cc > 0 && *--cp == '\n') {
            /*
             * A final newline is just stripped
             */
            *cp-- = '\0';
        }
        while (cp >= res) {
            if (*cp == '\n') {
                *cp = ' ';
            }
            cp--;
        }
        break;
    }
    return res;
bad:
    res = bmake_malloc(1);
    *res = '\0';
    return res;
}

/*-
 * Error --
 *      Print an error message given its format.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      The message is printed.
 */
/* VARARGS */
void
Error(const char *fmt, ...)
{
        va_list ap;
        FILE *err_file;

        err_file = debug_file;
        if (err_file == stdout)
                err_file = stderr;
        for (;;) {
                va_start(ap, fmt);
                fprintf(err_file, "%s: ", progname);
                (void)vfprintf(err_file, fmt, ap);
                va_end(ap);
                (void)fprintf(err_file, "\n");
                (void)fflush(err_file);
                if (err_file == stderr)
                        break;
                err_file = stderr;
        }
}

/*-
 * Fatal --
 *      Produce a Fatal error message. If jobs are running, waits for them
 *      to finish.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      The program exits
 */
/* VARARGS */
void
Fatal(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        if (jobsRunning)
                Job_Wait();

        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        (void)fflush(stderr);

        PrintOnError(NULL);

        if (DEBUG(GRAPH2) || DEBUG(GRAPH3))
                Targ_PrintGraph(2);
        Trace_Log(MAKEERROR, 0);
        exit(2);                /* Not 1 so -q can distinguish error */
}

/*
 * Punt --
 *      Major exception once jobs are being created. Kills all jobs, prints
 *      a message and exits.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      All children are killed indiscriminately and the program Lib_Exits
 */
/* VARARGS */
void
Punt(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        (void)fprintf(stderr, "%s: ", progname);
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        (void)fflush(stderr);

        PrintOnError(NULL);

        DieHorribly();
}

/*-
 * DieHorribly --
 *      Exit without giving a message.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      A big one...
 */
void
DieHorribly(void)
{
        if (jobsRunning)
                Job_AbortAll();
        if (DEBUG(GRAPH2))
                Targ_PrintGraph(2);
        Trace_Log(MAKEERROR, 0);
        exit(2);                /* Not 1, so -q can distinguish error */
}

/*
 * Finish --
 *      Called when aborting due to errors in child shell to signal
 *      abnormal exit.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      The program exits
 */
void
Finish(int errors)
                        /* number of errors encountered in Make_Make */
{
        Fatal("%d error%s", errors, errors == 1 ? "" : "s");
}

/*
 * enunlink --
 *      Remove a file carefully, avoiding directories.
 */
int
eunlink(const char *file)
{
        struct stat st;

        if (lstat(file, &st) == -1)
                return -1;

        if (S_ISDIR(st.st_mode)) {
                errno = EISDIR;
                return -1;
        }
        return unlink(file);
}

/*
 * execError --
 *      Print why exec failed, avoiding stdio.
 */
void
execError(const char *af, const char *av)
{
#ifdef USE_IOVEC
        int i = 0;
        struct iovec iov[8];
#define IOADD(s) \
        (void)(iov[i].iov_base = UNCONST(s), \
            iov[i].iov_len = strlen(iov[i].iov_base), \
            i++)
#else
#define IOADD(void)write(2, s, strlen(s))
#endif

        IOADD(progname);
        IOADD(": ");
        IOADD(af);
        IOADD("(");
        IOADD(av);
        IOADD(") failed (");
        IOADD(strerror(errno));
        IOADD(")\n");

#ifdef USE_IOVEC
        (void)writev(2, iov, 8);
#endif
}

/*
 * usage --
 *      exit with usage message
 */
static void
usage(void)
{
        (void)fprintf(stderr,
"usage: %s [-BeikNnqrstWX] \n\
            [-C directory] [-D variable] [-d flags] [-f makefile]\n\
            [-I directory] [-J private] [-j max_jobs] [-m directory] [-T file]\n\
            [-V variable] [variable=value] [target ...]\n", progname);
        exit(2);
}


int
PrintAddr(void *a, void *b)
{
    printf("%lx ", (unsigned long) a);
    return b ? 0 : 0;
}



void
PrintOnError(const char *s)
{
    char tmp[64];
    char *cp;

    if (s)
            printf("%s", s);
        
    printf("\n%s: stopped in %s\n", progname, curdir);
    strncpy(tmp, "${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'\n@}",
            sizeof(tmp) - 1);
    cp = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
    if (cp) {
            if (*cp)
                    printf("%s", cp);
            free(cp);
    }
}

void
Main_ExportMAKEFLAGS(Boolean first)
{
    static int once = 1;
    char tmp[64];
    char *s;

    if (once != first)
        return;
    once = 0;
    
    strncpy(tmp, "${.MAKEFLAGS} ${.MAKEOVERRIDES:O:u:@v@$v=${$v:Q}@}",
            sizeof(tmp));
    s = Var_Subst(NULL, tmp, VAR_CMD, 0);
    if (s && *s) {
#ifdef POSIX
        setenv("MAKEFLAGS", s, 1);
#else
        setenv("MAKE", s, 1);
#endif
    }
}