/* Argument parsing and main program of GNU Make.
Copyright (C) 1988-2014 Free Software Foundation, Inc.
This file is part of GNU Make.

GNU Make is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3 of the License, or (at your option) any later
version.

GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "makeint.h"
#include "filedef.h"
#include "dep.h"
#include "variable.h"
#include "job.h"
#include "commands.h"
#include "rule.h"
#include "debug.h"
#include "getopt.h"

#include <assert.h>
#ifdef _AMIGA
# include <dos/dos.h>
# include <proto/dos.h>
#endif
#ifdef WINDOWS32
# include <windows.h>
# include <io.h>
# include "pathstuff.h"
# include "sub_proc.h"
# include "w32err.h"
#endif
#ifdef __EMX__
# include <sys/types.h>
# include <sys/wait.h>
#endif
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif

#ifdef _AMIGA
int __stack = 20000; /* Make sure we have 20K of stack space */
#endif
#ifdef VMS
int vms_use_mcr_command = 0;
int vms_always_use_cmd_file = 0;
int vms_gnv_shell = 0;
int vms_legacy_behavior = 0;
int vms_comma_separator = 0;
int vms_unix_simulation = 0;
int vms_report_unix_paths = 0;

/* Evaluates if a VMS environment option is set, only look at first character */
static int
get_vms_env_flag (const char *name, int default_value)
{
char * value;
char x;

  value = getenv (name);
  if (value == NULL)
    return default_value;

  x = toupper (value[0]);
  switch (x)
    {
    case '1':
    case 'T':
    case 'E':
      return 1;
      break;
    case '0':
    case 'F':
    case 'D':
      return 0;
    }
}
#endif

void init_dir (void);
void remote_setup (void);
void remote_cleanup (void);
RETSIGTYPE fatal_error_signal (int sig);

void print_variable_data_base (void);
void print_dir_data_base (void);
void print_rule_data_base (void);
void print_vpath_data_base (void);

void verify_file_data_base (void);

#if defined HAVE_WAITPID || defined HAVE_WAIT3
# define HAVE_WAIT_NOHANG
#endif

#ifndef HAVE_UNISTD_H
int chdir ();
#endif
#ifndef STDC_HEADERS
# ifndef sun                    /* Sun has an incorrect decl in a header.  */
void exit (int) __attribute__ ((noreturn));
# endif
double atof ();
#endif

static void clean_jobserver (int status);
static void print_data_base (void);
static void print_version (void);
static void decode_switches (int argc, const char **argv, int env);
static void decode_env_switches (const char *envar, unsigned int len);
static struct variable *define_makeflags (int all, int makefile);
static char *quote_for_env (char *out, const char *in);
static void initialize_global_hash_tables (void);


/* The structure that describes an accepted command switch.  */

struct command_switch
  {
    int c;                      /* The switch character.  */

    enum                        /* Type of the value.  */
      {
        flag,                   /* Turn int flag on.  */
        flag_off,               /* Turn int flag off.  */
        string,                 /* One string per invocation.  */
        strlist,                /* One string per switch.  */
        filename,               /* A string containing a file name.  */
        positive_int,           /* A positive integer.  */
        floating,               /* A floating-point number (double).  */
        ignore                  /* Ignored.  */
      } type;

    void *value_ptr;    /* Pointer to the value-holding variable.  */

    unsigned int env:1;         /* Can come from MAKEFLAGS.  */
    unsigned int toenv:1;       /* Should be put in MAKEFLAGS.  */
    unsigned int no_makefile:1; /* Don't propagate when remaking makefiles.  */

    const void *noarg_value;    /* Pointer to value used if no arg given.  */
    const void *default_value;  /* Pointer to default value.  */

    const char *long_name;      /* Long option name.  */
  };

/* True if C is a switch value that corresponds to a short option.  */

#define short_option(c) ((c) <= CHAR_MAX)

/* The structure used to hold the list of strings given
   in command switches of a type that takes strlist arguments.  */

struct stringlist
  {
    const char **list;  /* Nil-terminated list of strings.  */
    unsigned int idx;   /* Index into above.  */
    unsigned int max;   /* Number of pointers allocated.  */
  };


/* The recognized command switches.  */

/* Nonzero means do extra verification (that may slow things down).  */

int verify_flag;

/* Nonzero means do not print commands to be executed (-s).  */

int silent_flag;

/* Nonzero means just touch the files
   that would appear to need remaking (-t)  */

int touch_flag;

/* Nonzero means just print what commands would need to be executed,
   don't actually execute them (-n).  */

int just_print_flag;

/* Print debugging info (--debug).  */

static struct stringlist *db_flags = 0;
static int debug_flag = 0;

int db_level = 0;

/* Synchronize output (--output-sync).  */

char *output_sync_option = 0;

#ifdef WINDOWS32
/* Suspend make in main for a short time to allow debugger to attach */

int suspend_flag = 0;
#endif

/* Environment variables override makefile definitions.  */

int env_overrides = 0;

/* Nonzero means ignore status codes returned by commands
   executed to remake files.  Just treat them all as successful (-i).  */

int ignore_errors_flag = 0;

/* Nonzero means don't remake anything, just print the data base
   that results from reading the makefile (-p).  */

int print_data_base_flag = 0;

/* Nonzero means don't remake anything; just return a nonzero status
   if the specified targets are not up to date (-q).  */

int question_flag = 0;

/* Nonzero means do not use any of the builtin rules (-r) / variables (-R).  */

int no_builtin_rules_flag = 0;
int no_builtin_variables_flag = 0;

/* Nonzero means keep going even if remaking some file fails (-k).  */

int keep_going_flag;
int default_keep_going_flag = 0;

/* Nonzero means check symlink mtimes.  */

int check_symlink_flag = 0;

/* Nonzero means print directory before starting and when done (-w).  */

int print_directory_flag = 0;

/* Nonzero means ignore print_directory_flag and never print the directory.
   This is necessary because print_directory_flag is set implicitly.  */

int inhibit_print_directory_flag = 0;

/* Nonzero means print version information.  */

int print_version_flag = 0;

/* List of makefiles given with -f switches.  */

static struct stringlist *makefiles = 0;

/* Size of the stack when we started.  */

#ifdef SET_STACK_SIZE
struct rlimit stack_limit;
#endif


/* Number of job slots (commands that can be run at once).  */

unsigned int job_slots = 1;
unsigned int default_job_slots = 1;
static unsigned int master_job_slots = 0;

/* Value of job_slots that means no limit.  */

static unsigned int inf_jobs = 0;

/* File descriptors for the jobs pipe.  */

char *jobserver_fds = 0;

int job_fds[2] = { -1, -1 };
int job_rfd = -1;

/* Handle for the mutex used on Windows to synchronize output of our
   children under -O.  */

char *sync_mutex = 0;

/* Maximum load average at which multiple jobs will be run.
   Negative values mean unlimited, while zero means limit to
   zero load (which could be useful to start infinite jobs remotely
   but one at a time locally).  */
#ifndef NO_FLOAT
double max_load_average = -1.0;
double default_load_average = -1.0;
#else
int max_load_average = -1;
int default_load_average = -1;
#endif

/* List of directories given with -C switches.  */

static struct stringlist *directories = 0;

/* List of include directories given with -I switches.  */

static struct stringlist *include_directories = 0;

/* List of files given with -o switches.  */

static struct stringlist *old_files = 0;

/* List of files given with -W switches.  */

static struct stringlist *new_files = 0;

/* List of strings to be eval'd.  */
static struct stringlist *eval_strings = 0;

/* If nonzero, we should just print usage and exit.  */

static int print_usage_flag = 0;

/* If nonzero, we should print a warning message
   for each reference to an undefined variable.  */

int warn_undefined_variables_flag;

/* If nonzero, always build all targets, regardless of whether
   they appear out of date or not.  */

static int always_make_set = 0;
int always_make_flag = 0;

/* If nonzero, we're in the "try to rebuild makefiles" phase.  */

int rebuilding_makefiles = 0;

/* Remember the original value of the SHELL variable, from the environment.  */

struct variable shell_var;

/* This character introduces a command: it's the first char on the line.  */

char cmd_prefix = '\t';


/* The usage output.  We write it this way to make life easier for the
   translators, especially those trying to translate to right-to-left
   languages like Hebrew.  */

static const char *const usage[] =
  {
    N_("Options:\n"),
    N_("\
  -b, -m                      Ignored for compatibility.\n"),
    N_("\
  -B, --always-make           Unconditionally make all targets.\n"),
    N_("\
  -C DIRECTORY, --directory=DIRECTORY\n\
                              Change to DIRECTORY before doing anything.\n"),
    N_("\
  -d                          Print lots of debugging information.\n"),
    N_("\
  --debug[=FLAGS]             Print various types of debugging information.\n"),
    N_("\
  -e, --environment-overrides\n\
                              Environment variables override makefiles.\n"),
    N_("\
  --eval=STRING               Evaluate STRING as a makefile statement.\n"),
    N_("\
  -f FILE, --file=FILE, --makefile=FILE\n\
                              Read FILE as a makefile.\n"),
    N_("\
  -h, --help                  Print this message and exit.\n"),
    N_("\
  -i, --ignore-errors         Ignore errors from recipes.\n"),
    N_("\
  -I DIRECTORY, --include-dir=DIRECTORY\n\
                              Search DIRECTORY for included makefiles.\n"),
    N_("\
  -j [N], --jobs[=N]          Allow N jobs at once; infinite jobs with no arg.\n"),
    N_("\
  -k, --keep-going            Keep going when some targets can't be made.\n"),
    N_("\
  -l [N], --load-average[=N], --max-load[=N]\n\
                              Don't start multiple jobs unless load is below N.\n"),
    N_("\
  -L, --check-symlink-times   Use the latest mtime between symlinks and target.\n"),
    N_("\
  -n, --just-print, --dry-run, --recon\n\
                              Don't actually run any recipe; just print them.\n"),
    N_("\
  -o FILE, --old-file=FILE, --assume-old=FILE\n\
                              Consider FILE to be very old and don't remake it.\n"),
    N_("\
  -O[TYPE], --output-sync[=TYPE]\n\
                              Synchronize output of parallel jobs by TYPE.\n"),
    N_("\
  -p, --print-data-base       Print make's internal database.\n"),
    N_("\
  -q, --question              Run no recipe; exit status says if up to date.\n"),
    N_("\
  -r, --no-builtin-rules      Disable the built-in implicit rules.\n"),
    N_("\
  -R, --no-builtin-variables  Disable the built-in variable settings.\n"),
    N_("\
  -s, --silent, --quiet       Don't echo recipes.\n"),
    N_("\
  -S, --no-keep-going, --stop\n\
                              Turns off -k.\n"),
    N_("\
  -t, --touch                 Touch targets instead of remaking them.\n"),
    N_("\
  --trace                     Print tracing information.\n"),
    N_("\
  -v, --version               Print the version number of make and exit.\n"),
    N_("\
  -w, --print-directory       Print the current directory.\n"),
    N_("\
  --no-print-directory        Turn off -w, even if it was turned on implicitly.\n"),
    N_("\
  -W FILE, --what-if=FILE, --new-file=FILE, --assume-new=FILE\n\
                              Consider FILE to be infinitely new.\n"),
    N_("\
  --warn-undefined-variables  Warn when an undefined variable is referenced.\n"),
    NULL
  };

/* The table of command switches.
   Order matters here: this is the order MAKEFLAGS will be constructed.
   So be sure all simple flags (single char, no argument) come first.  */

static const struct command_switch switches[] =
  {
    { 'b', ignore, 0, 0, 0, 0, 0, 0, 0 },
    { 'B', flag, &always_make_set, 1, 1, 0, 0, 0, "always-make" },
    { 'd', flag, &debug_flag, 1, 1, 0, 0, 0, 0 },
#ifdef WINDOWS32
    { 'D', flag, &suspend_flag, 1, 1, 0, 0, 0, "suspend-for-debug" },
#endif
    { 'e', flag, &env_overrides, 1, 1, 0, 0, 0, "environment-overrides", },
    { 'h', flag, &print_usage_flag, 0, 0, 0, 0, 0, "help" },
    { 'i', flag, &ignore_errors_flag, 1, 1, 0, 0, 0, "ignore-errors" },
    { 'k', flag, &keep_going_flag, 1, 1, 0, 0, &default_keep_going_flag,
      "keep-going" },
    { 'L', flag, &check_symlink_flag, 1, 1, 0, 0, 0, "check-symlink-times" },
    { 'm', ignore, 0, 0, 0, 0, 0, 0, 0 },
    { 'n', flag, &just_print_flag, 1, 1, 1, 0, 0, "just-print" },
    { 'p', flag, &print_data_base_flag, 1, 1, 0, 0, 0, "print-data-base" },
    { 'q', flag, &question_flag, 1, 1, 1, 0, 0, "question" },
    { 'r', flag, &no_builtin_rules_flag, 1, 1, 0, 0, 0, "no-builtin-rules" },
    { 'R', flag, &no_builtin_variables_flag, 1, 1, 0, 0, 0,
      "no-builtin-variables" },
    { 's', flag, &silent_flag, 1, 1, 0, 0, 0, "silent" },
    { 'S', flag_off, &keep_going_flag, 1, 1, 0, 0, &default_keep_going_flag,
      "no-keep-going" },
    { 't', flag, &touch_flag, 1, 1, 1, 0, 0, "touch" },
    { 'v', flag, &print_version_flag, 1, 1, 0, 0, 0, "version" },
    { 'w', flag, &print_directory_flag, 1, 1, 0, 0, 0, "print-directory" },

    /* These options take arguments.  */
    { 'C', filename, &directories, 0, 0, 0, 0, 0, "directory" },
    { 'f', filename, &makefiles, 0, 0, 0, 0, 0, "file" },
    { 'I', filename, &include_directories, 1, 1, 0, 0, 0,
      "include-dir" },
    { 'j', positive_int, &job_slots, 1, 1, 0, &inf_jobs, &default_job_slots,
      "jobs" },
#ifndef NO_FLOAT
    { 'l', floating, &max_load_average, 1, 1, 0, &default_load_average,
      &default_load_average, "load-average" },
#else
    { 'l', positive_int, &max_load_average, 1, 1, 0, &default_load_average,
      &default_load_average, "load-average" },
#endif
    { 'o', filename, &old_files, 0, 0, 0, 0, 0, "old-file" },
    { 'O', string, &output_sync_option, 1, 1, 0, "target", 0, "output-sync" },
    { 'W', filename, &new_files, 0, 0, 0, 0, 0, "what-if" },

    /* These are long-style options.  */
    { CHAR_MAX+1, strlist, &db_flags, 1, 1, 0, "basic", 0, "debug" },
    { CHAR_MAX+2, string, &jobserver_fds, 1, 1, 0, 0, 0, "jobserver-fds" },
    { CHAR_MAX+3, flag, &trace_flag, 1, 1, 0, 0, 0, "trace" },
    { CHAR_MAX+4, flag, &inhibit_print_directory_flag, 1, 1, 0, 0, 0,
      "no-print-directory" },
    { CHAR_MAX+5, flag, &warn_undefined_variables_flag, 1, 1, 0, 0, 0,
      "warn-undefined-variables" },
    { CHAR_MAX+6, strlist, &eval_strings, 1, 0, 0, 0, 0, "eval" },
    { CHAR_MAX+7, string, &sync_mutex, 1, 1, 0, 0, 0, "sync-mutex" },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0 }
  };

/* Secondary long names for options.  */

static struct option long_option_aliases[] =
  {
    { "quiet",          no_argument,            0, 's' },
    { "stop",           no_argument,            0, 'S' },
    { "new-file",       required_argument,      0, 'W' },
    { "assume-new",     required_argument,      0, 'W' },
    { "assume-old",     required_argument,      0, 'o' },
    { "max-load",       optional_argument,      0, 'l' },
    { "dry-run",        no_argument,            0, 'n' },
    { "recon",          no_argument,            0, 'n' },
    { "makefile",       required_argument,      0, 'f' },
  };

/* List of goal targets.  */

static struct dep *goals, *lastgoal;

/* List of variables which were defined on the command line
   (or, equivalently, in MAKEFLAGS).  */

struct command_variable
  {
    struct command_variable *next;
    struct variable *variable;
  };
static struct command_variable *command_variables;

/* The name we were invoked with.  */

#ifdef WINDOWS32
/* On MS-Windows, we chop off the .exe suffix in 'main', so this
   cannot be 'const'.  */
char *program;
#else
const char *program;
#endif

/* Our current directory before processing any -C options.  */

char *directory_before_chdir;

/* Our current directory after processing all -C options.  */

char *starting_directory;

/* Value of the MAKELEVEL variable at startup (or 0).  */

unsigned int makelevel;

/* Pointer to the value of the .DEFAULT_GOAL special variable.
   The value will be the name of the goal to remake if the command line
   does not override it.  It can be set by the makefile, or else it's
   the first target defined in the makefile whose name does not start
   with '.'.  */

struct variable * default_goal_var;

/* Pointer to structure for the file .DEFAULT
   whose commands are used for any file that has none of its own.
   This is zero if the makefiles do not define .DEFAULT.  */

struct file *default_file;

/* Nonzero if we have seen the magic '.POSIX' target.
   This turns on pedantic compliance with POSIX.2.  */

int posix_pedantic;

/* Nonzero if we have seen the '.SECONDEXPANSION' target.
   This turns on secondary expansion of prerequisites.  */

int second_expansion;

/* Nonzero if we have seen the '.ONESHELL' target.
   This causes the entire recipe to be handed to SHELL
   as a single string, potentially containing newlines.  */

int one_shell;

/* One of OUTPUT_SYNC_* if the "--output-sync" option was given.  This
   attempts to synchronize the output of parallel jobs such that the results
   of each job stay together.  */

int output_sync = OUTPUT_SYNC_NONE;

/* Nonzero if the "--trace" option was given.  */

int trace_flag = 0;

/* Nonzero if we have seen the '.NOTPARALLEL' target.
   This turns off parallel builds for this invocation of make.  */

int not_parallel;

/* Nonzero if some rule detected clock skew; we keep track so (a) we only
   print one warning about it during the run, and (b) we can print a final
   warning at the end of the run. */

int clock_skew_detected;

/* Map of possible stop characters for searching strings.  */
#ifndef UCHAR_MAX
# define UCHAR_MAX 255
#endif
unsigned short stopchar_map[UCHAR_MAX + 1] = {0};

/* If output-sync is enabled we'll collect all the output generated due to
   options, while reading makefiles, etc.  */

struct output make_sync;


/* Mask of signals that are being caught with fatal_error_signal.  */

#ifdef  POSIX
sigset_t fatal_signal_set;
#else
# ifdef HAVE_SIGSETMASK
int fatal_signal_mask;
# endif
#endif

#if !HAVE_DECL_BSD_SIGNAL && !defined bsd_signal
# if !defined HAVE_SIGACTION
#  define bsd_signal signal
# else
typedef RETSIGTYPE (*bsd_signal_ret_t) (int);

static bsd_signal_ret_t
bsd_signal (int sig, bsd_signal_ret_t func)
{
  struct sigaction act, oact;
  act.sa_handler = func;
  act.sa_flags = SA_RESTART;
  sigemptyset (&act.sa_mask);
  sigaddset (&act.sa_mask, sig);
  if (sigaction (sig, &act, &oact) != 0)
    return SIG_ERR;
  return oact.sa_handler;
}
# endif
#endif

static void
initialize_global_hash_tables (void)
{
  init_hash_global_variable_set ();
  strcache_init ();
  init_hash_files ();
  hash_init_directories ();
  hash_init_function_table ();
}

/* This character map locate stop chars when parsing GNU makefiles.
   Each element is true if we should stop parsing on that character.  */

static void
initialize_stopchar_map ()
{
  int i;

  stopchar_map[(int)'\0'] = MAP_NUL;
  stopchar_map[(int)'#'] = MAP_COMMENT;
  stopchar_map[(int)';'] = MAP_SEMI;
  stopchar_map[(int)'='] = MAP_EQUALS;
  stopchar_map[(int)':'] = MAP_COLON;
  stopchar_map[(int)'%'] = MAP_PERCENT;
  stopchar_map[(int)'|'] = MAP_PIPE;
  stopchar_map[(int)'.'] = MAP_DOT | MAP_USERFUNC;
  stopchar_map[(int)','] = MAP_COMMA;
  stopchar_map[(int)'$'] = MAP_VARIABLE;

  stopchar_map[(int)'-'] = MAP_USERFUNC;
  stopchar_map[(int)'_'] = MAP_USERFUNC;

  stopchar_map[(int)'/'] = MAP_DIRSEP;
#if defined(VMS)
  stopchar_map[(int)':'] = MAP_COLON | MAP_DIRSEP;
  stopchar_map[(int)']'] = MAP_DIRSEP;
  stopchar_map[(int)'>'] = MAP_DIRSEP;
#elif defined(HAVE_DOS_PATHS)
  stopchar_map[(int)'\\'] = MAP_DIRSEP;
#endif

  for (i = 1; i <= UCHAR_MAX; ++i)
    {
      if (isblank(i))
        stopchar_map[i] = MAP_BLANK;
      if (isspace(i))
        stopchar_map[i] |= MAP_SPACE;
      if (isalnum(i))
        stopchar_map[i] = MAP_USERFUNC;
    }
}

static const char *
expand_command_line_file (const char *name)
{
  const char *cp;
  char *expanded = 0;

  if (name[0] == '\0')
    O (fatal, NILF, _("empty string invalid as file name"));

  if (name[0] == '~')
    {
      expanded = tilde_expand (name);
      if (expanded && expanded[0] != '\0')
        name = expanded;
    }

  /* This is also done in parse_file_seq, so this is redundant
     for names read from makefiles.  It is here for names passed
     on the command line.  */
  while (name[0] == '.' && name[1] == '/')
    {
      name += 2;
      while (name[0] == '/')
        /* Skip following slashes: ".//foo" is "foo", not "/foo".  */
        ++name;
    }

  if (name[0] == '\0')
    {
      /* Nothing else but one or more "./", maybe plus slashes!  */
      name = "./";
    }

  cp = strcache_add (name);

  free (expanded);

  return cp;
}

/* Toggle -d on receipt of SIGUSR1.  */

#ifdef SIGUSR1
static RETSIGTYPE
debug_signal_handler (int sig UNUSED)
{
  db_level = db_level ? DB_NONE : DB_BASIC;
}
#endif

static void
decode_debug_flags (void)
{
  const char **pp;

  if (debug_flag)
    db_level = DB_ALL;

  if (db_flags)
    for (pp=db_flags->list; *pp; ++pp)
      {
        const char *p = *pp;

        while (1)
          {
            switch (tolower (p[0]))
              {
              case 'a':
                db_level |= DB_ALL;
                break;
              case 'b':
                db_level |= DB_BASIC;
                break;
              case 'i':
                db_level |= DB_BASIC | DB_IMPLICIT;
                break;
              case 'j':
                db_level |= DB_JOBS;
                break;
              case 'm':
                db_level |= DB_BASIC | DB_MAKEFILES;
                break;
              case 'n':
                db_level = 0;
                break;
              case 'v':
                db_level |= DB_BASIC | DB_VERBOSE;
                break;
              default:
                OS (fatal, NILF,
                    _("unknown debug level specification '%s'"), p);
              }

            while (*(++p) != '\0')
              if (*p == ',' || *p == ' ')
                {
                  ++p;
                  break;
                }

            if (*p == '\0')
              break;
          }
      }

  if (db_level)
    verify_flag = 1;

  if (! db_level)
    debug_flag = 0;
}

static void
decode_output_sync_flags (void)
{
  if (output_sync_option)
    {
      if (streq (output_sync_option, "none"))
        output_sync = OUTPUT_SYNC_NONE;
      else if (streq (output_sync_option, "line"))
        output_sync = OUTPUT_SYNC_LINE;
      else if (streq (output_sync_option, "target"))
        output_sync = OUTPUT_SYNC_TARGET;
      else if (streq (output_sync_option, "recurse"))
        output_sync = OUTPUT_SYNC_RECURSE;
      else
        OS (fatal, NILF,
            _("unknown output-sync type '%s'"), output_sync_option);
    }

  if (sync_mutex)
    RECORD_SYNC_MUTEX (sync_mutex);
}

#ifdef WINDOWS32

#ifndef NO_OUTPUT_SYNC

/* This is called from start_job_command when it detects that
   output_sync option is in effect.  The handle to the synchronization
   mutex is passed, as a string, to sub-makes via the --sync-mutex
   command-line argument.  */
void
prepare_mutex_handle_string (sync_handle_t handle)
{
  if (!sync_mutex)
    {
      /* Prepare the mutex handle string for our children.  */
      /* 2 hex digits per byte + 2 characters for "0x" + null.  */
      sync_mutex = xmalloc ((2 * sizeof (sync_handle_t)) + 2 + 1);
      sprintf (sync_mutex, "0x%Ix", handle);
      define_makeflags (1, 0);
    }
}

#endif  /* NO_OUTPUT_SYNC */

/*
 * HANDLE runtime exceptions by avoiding a requestor on the GUI. Capture
 * exception and print it to stderr instead.
 *
 * If ! DB_VERBOSE, just print a simple message and exit.
 * If DB_VERBOSE, print a more verbose message.
 * If compiled for DEBUG, let exception pass through to GUI so that
 *   debuggers can attach.
 */
LONG WINAPI
handle_runtime_exceptions (struct _EXCEPTION_POINTERS *exinfo)
{
  PEXCEPTION_RECORD exrec = exinfo->ExceptionRecord;
  LPSTR cmdline = GetCommandLine ();
  LPSTR prg = strtok (cmdline, " ");
  CHAR errmsg[1024];
#ifdef USE_EVENT_LOG
  HANDLE hEventSource;
  LPTSTR lpszStrings[1];
#endif

  if (! ISDB (DB_VERBOSE))
    {
      sprintf (errmsg,
               _("%s: Interrupt/Exception caught (code = 0x%lx, addr = 0x%p)\n"),
               prg, exrec->ExceptionCode, exrec->ExceptionAddress);
      fprintf (stderr, errmsg);
      exit (255);
    }

  sprintf (errmsg,
           _("\nUnhandled exception filter called from program %s\nExceptionCode = %lx\nExceptionFlags = %lx\nExceptionAddress = 0x%p\n"),
           prg, exrec->ExceptionCode, exrec->ExceptionFlags,
           exrec->ExceptionAddress);

  if (exrec->ExceptionCode == EXCEPTION_ACCESS_VIOLATION
      && exrec->NumberParameters >= 2)
    sprintf (&errmsg[strlen(errmsg)],
             (exrec->ExceptionInformation[0]
              ? _("Access violation: write operation at address 0x%p\n")
              : _("Access violation: read operation at address 0x%p\n")),
             (PVOID)exrec->ExceptionInformation[1]);

  /* turn this on if we want to put stuff in the event log too */
#ifdef USE_EVENT_LOG
  hEventSource = RegisterEventSource (NULL, "GNU Make");
  lpszStrings[0] = errmsg;

  if (hEventSource != NULL)
    {
      ReportEvent (hEventSource,         /* handle of event source */
                   EVENTLOG_ERROR_TYPE,  /* event type */
                   0,                    /* event category */
                   0,                    /* event ID */
                   NULL,                 /* current user's SID */
                   1,                    /* strings in lpszStrings */
                   0,                    /* no bytes of raw data */
                   lpszStrings,          /* array of error strings */
                   NULL);                /* no raw data */

      (VOID) DeregisterEventSource (hEventSource);
    }
#endif

  /* Write the error to stderr too */
  fprintf (stderr, errmsg);

#ifdef DEBUG
  return EXCEPTION_CONTINUE_SEARCH;
#else
  exit (255);
  return (255); /* not reached */
#endif
}

/*
 * On WIN32 systems we don't have the luxury of a /bin directory that
 * is mapped globally to every drive mounted to the system. Since make could
 * be invoked from any drive, and we don't want to propagate /bin/sh
 * to every single drive. Allow ourselves a chance to search for
 * a value for default shell here (if the default path does not exist).
 */

int
find_and_set_default_shell (const char *token)
{
  int sh_found = 0;
  char *atoken = 0;
  const char *search_token;
  const char *tokend;
  PATH_VAR(sh_path);
  extern const char *default_shell;

  if (!token)
    search_token = default_shell;
  else
    search_token = atoken = xstrdup (token);

  /* If the user explicitly requests the DOS cmd shell, obey that request.
     However, make sure that's what they really want by requiring the value
     of SHELL either equal, or have a final path element of, "cmd" or
     "cmd.exe" case-insensitive.  */
  tokend = search_token + strlen (search_token) - 3;
  if (((tokend == search_token
        || (tokend > search_token
            && (tokend[-1] == '/' || tokend[-1] == '\\')))
       && !strcasecmp (tokend, "cmd"))
      || ((tokend - 4 == search_token
           || (tokend - 4 > search_token
               && (tokend[-5] == '/' || tokend[-5] == '\\')))
          && !strcasecmp (tokend - 4, "cmd.exe")))
    {
      batch_mode_shell = 1;
      unixy_shell = 0;
      sprintf (sh_path, "%s", search_token);
      default_shell = xstrdup (w32ify (sh_path, 0));
      DB (DB_VERBOSE, (_("find_and_set_shell() setting default_shell = %s\n"),
                       default_shell));
      sh_found = 1;
    }
  else if (!no_default_sh_exe
           && (token == NULL || !strcmp (search_token, default_shell)))
    {
      /* no new information, path already set or known */
      sh_found = 1;
    }
  else if (_access (search_token, 0) == 0)
    {
      /* search token path was found */
      sprintf (sh_path, "%s", search_token);
      default_shell = xstrdup (w32ify (sh_path, 0));
      DB (DB_VERBOSE, (_("find_and_set_shell() setting default_shell = %s\n"),
                       default_shell));
      sh_found = 1;
    }
  else
    {
      char *p;
      struct variable *v = lookup_variable (STRING_SIZE_TUPLE ("PATH"));

      /* Search Path for shell */
      if (v && v->value)
        {
          char *ep;

          p  = v->value;
          ep = strchr (p, PATH_SEPARATOR_CHAR);

          while (ep && *ep)
            {
              *ep = '\0';

              sprintf (sh_path, "%s/%s", p, search_token);
              if (_access (sh_path, 0) == 0)
                {
                  default_shell = xstrdup (w32ify (sh_path, 0));
                  sh_found = 1;
                  *ep = PATH_SEPARATOR_CHAR;

                  /* terminate loop */
                  p += strlen (p);
                }
              else
                {
                  *ep = PATH_SEPARATOR_CHAR;
                  p = ++ep;
                }

              ep = strchr (p, PATH_SEPARATOR_CHAR);
            }

          /* be sure to check last element of Path */
          if (p && *p)
            {
              sprintf (sh_path, "%s/%s", p, search_token);
              if (_access (sh_path, 0) == 0)
                {
                  default_shell = xstrdup (w32ify (sh_path, 0));
                  sh_found = 1;
                }
            }

          if (sh_found)
            DB (DB_VERBOSE,
                (_("find_and_set_shell() path search set default_shell = %s\n"),
                 default_shell));
        }
    }

  /* naive test */
  if (!unixy_shell && sh_found
      && (strstr (default_shell, "sh") || strstr (default_shell, "SH")))
    {
      unixy_shell = 1;
      batch_mode_shell = 0;
    }

#ifdef BATCH_MODE_ONLY_SHELL
  batch_mode_shell = 1;
#endif

  free (atoken);

  return (sh_found);
}
#endif  /* WINDOWS32 */

#ifdef __MSDOS__
static void
msdos_return_to_initial_directory (void)
{
  if (directory_before_chdir)
    chdir (directory_before_chdir);
}
#endif  /* __MSDOS__ */


#ifdef _AMIGA
int
main (int argc, char **argv)
#else
int
main (int argc, char **argv, char **envp)
#endif
{
  static char *stdin_nm = 0;
  int makefile_status = MAKE_SUCCESS;
  struct dep *read_files;
  PATH_VAR (current_directory);
  unsigned int restarts = 0;
  unsigned int syncing = 0;
#ifdef WINDOWS32
  const char *unix_path = NULL;
  const char *windows32_path = NULL;

  SetUnhandledExceptionFilter (handle_runtime_exceptions);

  /* start off assuming we have no shell */
  unixy_shell = 0;
  no_default_sh_exe = 1;
#endif

  output_init (&make_sync);

  initialize_stopchar_map();

#ifdef SET_STACK_SIZE
 /* Get rid of any avoidable limit on stack size.  */
  {
    struct rlimit rlim;

    /* Set the stack limit huge so that alloca does not fail.  */
    if (getrlimit (RLIMIT_STACK, &rlim) == 0
        && rlim.rlim_cur > 0 && rlim.rlim_cur < rlim.rlim_max)
      {
        stack_limit = rlim;
        rlim.rlim_cur = rlim.rlim_max;
        setrlimit (RLIMIT_STACK, &rlim);
      }
    else
      stack_limit.rlim_cur = 0;
  }
#endif

  /* Needed for OS/2 */
  initialize_main (&argc, &argv);

#ifdef MAKE_MAINTAINER_MODE
  /* In maintainer mode we always enable verification.  */
  verify_flag = 1;
#endif

#if defined (__MSDOS__) && !defined (_POSIX_SOURCE)
  /* Request the most powerful version of 'system', to
     make up for the dumb default shell.  */
  __system_flags = (__system_redirect
                    | __system_use_shell
                    | __system_allow_multiple_cmds
                    | __system_allow_long_cmds
                    | __system_handle_null_commands
                    | __system_emulate_chdir);

#endif

  /* Set up gettext/internationalization support.  */
  setlocale (LC_ALL, "");
  /* The cast to void shuts up compiler warnings on systems that
     disable NLS.  */
  (void)bindtextdomain (PACKAGE, LOCALEDIR);
  (void)textdomain (PACKAGE);

#ifdef  POSIX
  sigemptyset (&fatal_signal_set);
#define ADD_SIG(sig)    sigaddset (&fatal_signal_set, sig)
#else
#ifdef  HAVE_SIGSETMASK
  fatal_signal_mask = 0;
#define ADD_SIG(sig)    fatal_signal_mask |= sigmask (sig)
#else
#define ADD_SIG(sig)    (void)sig
#endif
#endif

#define FATAL_SIG(sig)                                                        \
  if (bsd_signal (sig, fatal_error_signal) == SIG_IGN)                        \
    bsd_signal (sig, SIG_IGN);                                                \
  else                                                                        \
    ADD_SIG (sig);

#ifdef SIGHUP
  FATAL_SIG (SIGHUP);
#endif
#ifdef SIGQUIT
  FATAL_SIG (SIGQUIT);
#endif
  FATAL_SIG (SIGINT);
  FATAL_SIG (SIGTERM);

#ifdef __MSDOS__
  /* Windows 9X delivers FP exceptions in child programs to their
     parent!  We don't want Make to die when a child divides by zero,
     so we work around that lossage by catching SIGFPE.  */
  FATAL_SIG (SIGFPE);
#endif

#ifdef  SIGDANGER
  FATAL_SIG (SIGDANGER);
#endif
#ifdef SIGXCPU
  FATAL_SIG (SIGXCPU);
#endif
#ifdef SIGXFSZ
  FATAL_SIG (SIGXFSZ);
#endif

#undef  FATAL_SIG

  /* Do not ignore the child-death signal.  This must be done before
     any children could possibly be created; otherwise, the wait
     functions won't work on systems with the SVR4 ECHILD brain
     damage, if our invoker is ignoring this signal.  */

#ifdef HAVE_WAIT_NOHANG
# if defined SIGCHLD
  (void) bsd_signal (SIGCHLD, SIG_DFL);
# endif
# if defined SIGCLD && SIGCLD != SIGCHLD
  (void) bsd_signal (SIGCLD, SIG_DFL);
# endif
#endif

  output_init (NULL);

  /* Figure out where this program lives.  */

  if (argv[0] == 0)
    argv[0] = (char *)"";
  if (argv[0][0] == '\0')
    program = "make";
  else
    {
      program = strrchr (argv[0], '/');
#if defined(__MSDOS__) || defined(__EMX__)
      if (program == 0)
        program = strrchr (argv[0], '\\');
      else
        {
          /* Some weird environments might pass us argv[0] with
             both kinds of slashes; we must find the rightmost.  */
          char *p = strrchr (argv[0], '\\');
          if (p && p > program)
            program = p;
        }
      if (program == 0 && argv[0][1] == ':')
        program = argv[0] + 1;
#endif
#ifdef WINDOWS32
      if (program == 0)
        {
          /* Extract program from full path */
          program = strrchr (argv[0], '\\');
          if (program)
            {
              int argv0_len = strlen (program);
              if (argv0_len > 4 && streq (&program[argv0_len - 4], ".exe"))
                /* Remove .exe extension */
                program[argv0_len - 4] = '\0';
            }
        }
#endif
#ifdef VMS
      set_program_name (argv[0]);
      program = program_name;
      {
        const char *shell;
        char pwdbuf[256];
        char *pwd;
        shell = getenv ("SHELL");
        if (shell != NULL)
          vms_gnv_shell = 1;

        /* Need to know if CRTL set to report UNIX paths.  Use getcwd as
           it works on all versions of VMS. */
        pwd = getcwd(pwdbuf, 256);
        if (pwd[0] == '/')
          vms_report_unix_paths = 1;

        vms_use_mcr_command = get_vms_env_flag ("GNV$MAKE_USE_MCR", 0);

        vms_always_use_cmd_file = get_vms_env_flag ("GNV$MAKE_USE_CMD_FILE", 0);

        /* Legacy behavior is on VMS is older behavior that needed to be
           changed to be compatible with standard make behavior.
           For now only completely disable when running under a Bash shell.
           TODO: Update VMS built in recipes and macros to not need this
           behavior, at which time the default may change. */
        vms_legacy_behavior = get_vms_env_flag ("GNV$MAKE_OLD_VMS",
                                                !vms_gnv_shell);

        /* VMS was changed to use a comma separator in the past, but that is
           incompatible with built in functions that expect space separated
           lists.  Allow this to be selectively turned off. */
        vms_comma_separator = get_vms_env_flag ("GNV$MAKE_COMMA",
                                                vms_legacy_behavior);

        /* Some Posix shell syntax options are incompatible with VMS syntax.
           VMS requires double quotes for strings and escapes quotes
           differently.  When this option is active, VMS will try
           to simulate Posix shell simulations instead of using
           VMS DCL behavior. */
        vms_unix_simulation = get_vms_env_flag ("GNV$MAKE_SHELL_SIM",
                                                !vms_legacy_behavior);

      }
      if (need_vms_symbol () && !vms_use_mcr_command)
        create_foreign_command (program_name, argv[0]);
#else
      if (program == 0)
        program = argv[0];
      else
        ++program;
#endif
    }

  /* Set up to access user data (files).  */
  user_access ();

  initialize_global_hash_tables ();

  /* Figure out where we are.  */

#ifdef WINDOWS32
  if (getcwd_fs (current_directory, GET_PATH_MAX) == 0)
#else
  if (getcwd (current_directory, GET_PATH_MAX) == 0)
#endif
    {
#ifdef  HAVE_GETCWD
      perror_with_name ("getcwd", "");
#else
      OS (error, NILF, "getwd: %s", current_directory);
#endif
      current_directory[0] = '\0';
      directory_before_chdir = 0;
    }
  else
    directory_before_chdir = xstrdup (current_directory);

#ifdef  __MSDOS__
  /* Make sure we will return to the initial directory, come what may.  */
  atexit (msdos_return_to_initial_directory);
#endif

  /* Initialize the special variables.  */
  define_variable_cname (".VARIABLES", "", o_default, 0)->special = 1;
  /* define_variable_cname (".TARGETS", "", o_default, 0)->special = 1; */
  define_variable_cname (".RECIPEPREFIX", "", o_default, 0)->special = 1;
  define_variable_cname (".SHELLFLAGS", "-c", o_default, 0);

  /* Set up .FEATURES
     Use a separate variable because define_variable_cname() is a macro and
     some compilers (MSVC) don't like conditionals in macros.  */
  {
    const char *features = "target-specific order-only second-expansion"
                           " else-if shortest-stem undefine oneshell"
#ifndef NO_ARCHIVES
                           " archives"
#endif
#ifdef MAKE_JOBSERVER
                           " jobserver"
#endif
#ifndef NO_OUTPUT_SYNC
                           " output-sync"
#endif
#ifdef MAKE_SYMLINKS
                           " check-symlink"
#endif
#ifdef HAVE_GUILE
                           " guile"
#endif
#ifdef MAKE_LOAD
                           " load"
#endif
                           ;

    define_variable_cname (".FEATURES", features, o_default, 0);
  }

  /* Configure GNU Guile support */
  guile_gmake_setup (NILF);

  /* Read in variables from the environment.  It is important that this be
     done before $(MAKE) is figured out so its definitions will not be
     from the environment.  */

#ifndef _AMIGA
  {
    unsigned int i;

    for (i = 0; envp[i] != 0; ++i)
      {
        struct variable *v;
        const char *ep = envp[i];
        /* By default, export all variables culled from the environment.  */
        enum variable_export export = v_export;
        unsigned int len;

        while (! STOP_SET (*ep, MAP_EQUALS))
          ++ep;

        /* If there's no equals sign it's a malformed environment.  Ignore.  */
        if (*ep == '\0')
          continue;

#ifdef WINDOWS32
        if (!unix_path && strneq (envp[i], "PATH=", 5))
          unix_path = ep+1;
        else if (!strnicmp (envp[i], "Path=", 5))
          {
            if (!windows32_path)
              windows32_path = ep+1;
            /* PATH gets defined after the loop exits.  */
            continue;
          }
#endif

        /* Length of the variable name, and skip the '='.  */
        len = ep++ - envp[i];

        /* If this is MAKE_RESTARTS, check to see if the "already printed
           the enter statement" flag is set.  */
        if (len == 13 && strneq (envp[i], "MAKE_RESTARTS", 13))
          {
            if (*ep == '-')
              {
                OUTPUT_TRACED ();
                ++ep;
              }
            restarts = (unsigned int) atoi (ep);
            export = v_noexport;
          }

        v = define_variable (envp[i], len, ep, o_env, 1);

        /* POSIX says the value of SHELL set in the makefile won't change the
           value of SHELL given to subprocesses.  */
        if (streq (v->name, "SHELL"))
          {
#ifndef __MSDOS__
            export = v_noexport;
#endif
            shell_var.name = xstrdup ("SHELL");
            shell_var.length = 5;
            shell_var.value = xstrdup (ep);
          }

        v->export = export;
      }
  }
#ifdef WINDOWS32
    /* If we didn't find a correctly spelled PATH we define PATH as
     * either the first misspelled value or an empty string
     */
    if (!unix_path)
      define_variable_cname ("PATH", windows32_path ? windows32_path : "",
                             o_env, 1)->export = v_export;
#endif
#else /* For Amiga, read the ENV: device, ignoring all dirs */
    {
        BPTR env, file, old;
        char buffer[1024];
        int len;
        __aligned struct FileInfoBlock fib;

        env = Lock ("ENV:", ACCESS_READ);
        if (env)
          {
            old = CurrentDir (DupLock (env));
            Examine (env, &fib);

            while (ExNext (env, &fib))
              {
                if (fib.fib_DirEntryType < 0) /* File */
                  {
                    /* Define an empty variable. It will be filled in
                       variable_lookup(). Makes startup quite a bit faster. */
                    define_variable (fib.fib_FileName,
                                     strlen (fib.fib_FileName),
                                     "", o_env, 1)->export = v_export;
                  }
              }
            UnLock (env);
            UnLock (CurrentDir (old));
          }
    }
#endif

  /* Decode the switches.  */
  decode_env_switches (STRING_SIZE_TUPLE ("GNUMAKEFLAGS"));

  /* Clear GNUMAKEFLAGS to avoid duplication.  */
  define_variable_cname ("GNUMAKEFLAGS", "", o_env, 0);

  decode_env_switches (STRING_SIZE_TUPLE ("MAKEFLAGS"));

  /* In output sync mode we need to sync any output generated by reading the
     makefiles, such as in $(info ...) or stderr from $(shell ...) etc.  */

  syncing = make_sync.syncout = (output_sync == OUTPUT_SYNC_LINE
                                 || output_sync == OUTPUT_SYNC_TARGET);
  OUTPUT_SET (&make_sync);

#if 0
  /* People write things like:
        MFLAGS="CC=gcc -pipe" "CFLAGS=-g"
     and we set the -p, -i and -e switches.  Doesn't seem quite right.  */
  decode_env_switches (STRING_SIZE_TUPLE ("MFLAGS"));
#endif

  decode_switches (argc, (const char **)argv, 0);

    /* Set a variable specifying whether stdout/stdin is hooked to a TTY.  */
#ifdef HAVE_ISATTY
    if (isatty (fileno (stdout)))
      if (! lookup_variable (STRING_SIZE_TUPLE ("MAKE_TERMOUT")))
        {
          const char *tty = TTYNAME (fileno (stdout));
          define_variable_cname ("MAKE_TERMOUT", tty ? tty : DEFAULT_TTYNAME,
                                 o_default, 0)->export = v_export;
        }
    if (isatty (fileno (stderr)))
      if (! lookup_variable (STRING_SIZE_TUPLE ("MAKE_TERMERR")))
        {
          const char *tty = TTYNAME (fileno (stderr));
          define_variable_cname ("MAKE_TERMERR", tty ? tty : DEFAULT_TTYNAME,
                                 o_default, 0)->export = v_export;
        }
#endif

  /* Reset in case the switches changed our minds.  */
  syncing = (output_sync == OUTPUT_SYNC_LINE
             || output_sync == OUTPUT_SYNC_TARGET);

  if (make_sync.syncout && ! syncing)
    output_close (&make_sync);

  make_sync.syncout = syncing;
  OUTPUT_SET (&make_sync);

  /* Figure out the level of recursion.  */
  {
    struct variable *v = lookup_variable (STRING_SIZE_TUPLE (MAKELEVEL_NAME));
    if (v && v->value[0] != '\0' && v->value[0] != '-')
      makelevel = (unsigned int) atoi (v->value);
    else
      makelevel = 0;
  }

#ifdef WINDOWS32
  if (suspend_flag)
    {
      fprintf (stderr, "%s (pid = %ld)\n", argv[0], GetCurrentProcessId ());
      fprintf (stderr, _("%s is suspending for 30 seconds..."), argv[0]);
      Sleep (30 * 1000);
      fprintf (stderr, _("done sleep(30). Continuing.\n"));
    }
#endif

  /* Set always_make_flag if -B was given and we've not restarted already.  */
  always_make_flag = always_make_set && (restarts == 0);

  /* Print version information, and exit.  */
  if (print_version_flag)
    {
      print_version ();
      die (MAKE_SUCCESS);
    }

  if (ISDB (DB_BASIC))
    print_version ();

#ifndef VMS
  /* Set the "MAKE_COMMAND" variable to the name we were invoked with.
     (If it is a relative pathname with a slash, prepend our directory name
     so the result will run the same program regardless of the current dir.
     If it is a name with no slash, we can only hope that PATH did not
     find it in the current directory.)  */
#ifdef WINDOWS32
  /*
   * Convert from backslashes to forward slashes for
   * programs like sh which don't like them. Shouldn't
   * matter if the path is one way or the other for
   * CreateProcess().
   */
  if (strpbrk (argv[0], "/:\\") || strstr (argv[0], "..")
      || strneq (argv[0], "//", 2))
    argv[0] = xstrdup (w32ify (argv[0], 1));
#else /* WINDOWS32 */
#if defined (__MSDOS__) || defined (__EMX__)
  if (strchr (argv[0], '\\'))
    {
      char *p;

      argv[0] = xstrdup (argv[0]);
      for (p = argv[0]; *p; p++)
        if (*p == '\\')
          *p = '/';
    }
  /* If argv[0] is not in absolute form, prepend the current
     directory.  This can happen when Make is invoked by another DJGPP
     program that uses a non-absolute name.  */
  if (current_directory[0] != '\0'
      && argv[0] != 0
      && (argv[0][0] != '/' && (argv[0][0] == '\0' || argv[0][1] != ':'))
# ifdef __EMX__
      /* do not prepend cwd if argv[0] contains no '/', e.g. "make" */
      && (strchr (argv[0], '/') != 0 || strchr (argv[0], '\\') != 0)
# endif
      )
    argv[0] = xstrdup (concat (3, current_directory, "/", argv[0]));
#else  /* !__MSDOS__ */
  if (current_directory[0] != '\0'
      && argv[0] != 0 && argv[0][0] != '/' && strchr (argv[0], '/') != 0
#ifdef HAVE_DOS_PATHS
      && (argv[0][0] != '\\' && (!argv[0][0] || argv[0][1] != ':'))
      && strchr (argv[0], '\\') != 0
#endif
      )
    argv[0] = xstrdup (concat (3, current_directory, "/", argv[0]));
#endif /* !__MSDOS__ */
#endif /* WINDOWS32 */
#endif

  /* We may move, but until we do, here we are.  */
  starting_directory = current_directory;

#ifdef MAKE_JOBSERVER
  /* If the jobserver-fds option is seen, make sure that -j is reasonable.
     This can't be usefully set in the makefile, and we want to verify the
     FDs are valid before any other aspect of make has a chance to start
     using them for something else.  */

  if (jobserver_fds)
    {
      /* Make sure the jobserver option has the proper format.  */
      const char *cp = jobserver_fds;

#ifdef WINDOWS32
      if (! open_jobserver_semaphore (cp))
        {
          DWORD err = GetLastError ();
          const char *estr = map_windows32_error_to_string (err);
          fatal (NILF, strlen (cp) + INTSTR_LENGTH + strlen (estr),
                 _("internal error: unable to open jobserver semaphore '%s': (Error %ld: %s)"),
                 cp, err, estr);
        }
      DB (DB_JOBS, (_("Jobserver client (semaphore %s)\n"), cp));
#else
      if (sscanf (cp, "%d,%d", &job_fds[0], &job_fds[1]) != 2)
        OS (fatal, NILF,
            _("internal error: invalid --jobserver-fds string '%s'"), cp);

      DB (DB_JOBS,
          (_("Jobserver client (fds %d,%d)\n"), job_fds[0], job_fds[1]));
#endif

      /* The combination of a pipe + !job_slots means we're using the
         jobserver.  If !job_slots and we don't have a pipe, we can start
         infinite jobs.  If we see both a pipe and job_slots >0 that means the
         user set -j explicitly.  This is broken; in this case obey the user
         (ignore the jobserver pipe for this make) but print a message.
         If we've restarted, we already printed this the first time.  */

      if (job_slots > 0)
        {
          if (! restarts)
            O (error, NILF,
               _("warning: -jN forced in submake: disabling jobserver mode."));
        }
#ifndef WINDOWS32
#ifdef HAVE_FCNTL
# define FD_OK(_f) ((fcntl ((_f), F_GETFD) != -1) || (errno != EBADF))
#else
# define FD_OK(_f) 1
#endif
      /* Create a duplicate pipe, that will be closed in the SIGCHLD
         handler.  If this fails with EBADF, the parent has closed the pipe
         on us because it didn't think we were a submake.  If so, print a
         warning then default to -j1.  */
      else if (!FD_OK (job_fds[0]) || !FD_OK (job_fds[1])
               || (job_rfd = dup (job_fds[0])) < 0)
        {
          if (errno != EBADF)
            pfatal_with_name (_("dup jobserver"));

          O (error, NILF,
             _("warning: jobserver unavailable: using -j1.  Add '+' to parent make rule."));
          job_slots = 1;
          job_fds[0] = job_fds[1] = -1;
        }
#endif

      if (job_slots > 0)
        {
#ifdef WINDOWS32
          free_jobserver_semaphore ();
#else
          if (job_fds[0] >= 0)
            close (job_fds[0]);
          if (job_fds[1] >= 0)
            close (job_fds[1]);
#endif
          job_fds[0] = job_fds[1] = -1;

          free (jobserver_fds);
          jobserver_fds = 0;
        }
    }
#endif

  /* The extra indirection through $(MAKE_COMMAND) is done
     for hysterical raisins.  */

#ifdef VMS
  if (vms_use_mcr_command)
    define_variable_cname ("MAKE_COMMAND", vms_command (argv[0]), o_default, 0);
  else
    define_variable_cname ("MAKE_COMMAND", program, o_default, 0);
#else
  define_variable_cname ("MAKE_COMMAND", argv[0], o_default, 0);
#endif
  define_variable_cname ("MAKE", "$(MAKE_COMMAND)", o_default, 1);

  if (command_variables != 0)
    {
      struct command_variable *cv;
      struct variable *v;
      unsigned int len = 0;
      char *value, *p;

      /* Figure out how much space will be taken up by the command-line
         variable definitions.  */
      for (cv = command_variables; cv != 0; cv = cv->next)
        {
          v = cv->variable;
          len += 2 * strlen (v->name);
          if (! v->recursive)
            ++len;
          ++len;
          len += 2 * strlen (v->value);
          ++len;
        }

      /* Now allocate a buffer big enough and fill it.  */
      p = value = alloca (len);
      for (cv = command_variables; cv != 0; cv = cv->next)
        {
          v = cv->variable;
          p = quote_for_env (p, v->name);
          if (! v->recursive)
            *p++ = ':';
          *p++ = '=';
          p = quote_for_env (p, v->value);
          *p++ = ' ';
        }
      p[-1] = '\0';             /* Kill the final space and terminate.  */

      /* Define an unchangeable variable with a name that no POSIX.2
         makefile could validly use for its own variable.  */
      define_variable_cname ("-*-command-variables-*-", value, o_automatic, 0);

      /* Define the variable; this will not override any user definition.
         Normally a reference to this variable is written into the value of
         MAKEFLAGS, allowing the user to override this value to affect the
         exported value of MAKEFLAGS.  In POSIX-pedantic mode, we cannot
         allow the user's setting of MAKEOVERRIDES to affect MAKEFLAGS, so
         a reference to this hidden variable is written instead. */
      define_variable_cname ("MAKEOVERRIDES", "${-*-command-variables-*-}",
                             o_env, 1);
#ifdef VMS
      vms_export_dcl_symbol ("MAKEOVERRIDES", "${-*-command-variables-*-}");
#endif
    }

  /* If there were -C flags, move ourselves about.  */
  if (directories != 0)
    {
      unsigned int i;
      for (i = 0; directories->list[i] != 0; ++i)
        {
          const char *dir = directories->list[i];
#ifdef WINDOWS32
          /* WINDOWS32 chdir() doesn't work if the directory has a trailing '/'
             But allow -C/ just in case someone wants that.  */
          {
            char *p = (char *)dir + strlen (dir) - 1;
            while (p > dir && (p[0] == '/' || p[0] == '\\'))
              --p;
            p[1] = '\0';
          }
#endif
          if (chdir (dir) < 0)
            pfatal_with_name (dir);
        }
    }

#ifdef WINDOWS32
  /*
   * THIS BLOCK OF CODE MUST COME AFTER chdir() CALL ABOVE IN ORDER
   * TO NOT CONFUSE THE DEPENDENCY CHECKING CODE IN implicit.c.
   *
   * The functions in dir.c can incorrectly cache information for "."
   * before we have changed directory and this can cause file
   * lookups to fail because the current directory (.) was pointing
   * at the wrong place when it was first evaluated.
   */
   no_default_sh_exe = !find_and_set_default_shell (NULL);
#endif /* WINDOWS32 */

  /* Except under -s, always do -w in sub-makes and under -C.  */
  if (!silent_flag && (directories != 0 || makelevel > 0))
    print_directory_flag = 1;

  /* Let the user disable that with --no-print-directory.  */
  if (inhibit_print_directory_flag)
    print_directory_flag = 0;

  /* If -R was given, set -r too (doesn't make sense otherwise!)  */
  if (no_builtin_variables_flag)
    no_builtin_rules_flag = 1;

  /* Construct the list of include directories to search.  */

  construct_include_path (include_directories == 0
                          ? 0 : include_directories->list);

  /* If we chdir'ed, figure out where we are now.  */
  if (directories)
    {
#ifdef WINDOWS32
      if (getcwd_fs (current_directory, GET_PATH_MAX) == 0)
#else
      if (getcwd (current_directory, GET_PATH_MAX) == 0)
#endif
        {
#ifdef  HAVE_GETCWD
          perror_with_name ("getcwd", "");
#else
          OS (error, NILF, "getwd: %s", current_directory);
#endif
          starting_directory = 0;
        }
      else
        starting_directory = current_directory;
    }

  define_variable_cname ("CURDIR", current_directory, o_file, 0);

  /* Read any stdin makefiles into temporary files.  */

  if (makefiles != 0)
    {
      unsigned int i;
      for (i = 0; i < makefiles->idx; ++i)
        if (makefiles->list[i][0] == '-' && makefiles->list[i][1] == '\0')
          {
            /* This makefile is standard input.  Since we may re-exec
               and thus re-read the makefiles, we read standard input
               into a temporary file and read from that.  */
            FILE *outfile;
            char *template;
            const char *tmpdir;

            if (stdin_nm)
              O (fatal, NILF,
                 _("Makefile from standard input specified twice."));

#ifdef VMS
# define DEFAULT_TMPDIR     "/sys$scratch/"
#else
# ifdef P_tmpdir
#  define DEFAULT_TMPDIR    P_tmpdir
# else
#  define DEFAULT_TMPDIR    "/tmp"
# endif
#endif
#define DEFAULT_TMPFILE     "GmXXXXXX"

            if (((tmpdir = getenv ("TMPDIR")) == NULL || *tmpdir == '\0')
#if defined (__MSDOS__) || defined (WINDOWS32) || defined (__EMX__)
                /* These are also used commonly on these platforms.  */
                && ((tmpdir = getenv ("TEMP")) == NULL || *tmpdir == '\0')
                && ((tmpdir = getenv ("TMP")) == NULL || *tmpdir == '\0')
#endif
               )
              tmpdir = DEFAULT_TMPDIR;

            template = alloca (strlen (tmpdir) + CSTRLEN (DEFAULT_TMPFILE) + 2);
            strcpy (template, tmpdir);

#ifdef HAVE_DOS_PATHS
            if (strchr ("/\\", template[strlen (template) - 1]) == NULL)
              strcat (template, "/");
#else
# ifndef VMS
            if (template[strlen (template) - 1] != '/')
              strcat (template, "/");
# endif /* !VMS */
#endif /* !HAVE_DOS_PATHS */

            strcat (template, DEFAULT_TMPFILE);
            outfile = output_tmpfile (&stdin_nm, template);
            if (outfile == 0)
              pfatal_with_name (_("fopen (temporary file)"));
            while (!feof (stdin) && ! ferror (stdin))
              {
                char buf[2048];
                unsigned int n = fread (buf, 1, sizeof (buf), stdin);
                if (n > 0 && fwrite (buf, 1, n, outfile) != n)
                  pfatal_with_name (_("fwrite (temporary file)"));
              }
            fclose (outfile);

            /* Replace the name that read_all_makefiles will
               see with the name of the temporary file.  */
            makefiles->list[i] = strcache_add (stdin_nm);

            /* Make sure the temporary file will not be remade.  */
            {
              struct file *f = enter_file (strcache_add (stdin_nm));
              f->updated = 1;
              f->update_status = us_success;
              f->command_state = cs_finished;
              /* Can't be intermediate, or it'll be removed too early for
                 make re-exec.  */
              f->intermediate = 0;
              f->dontcare = 0;
            }
          }
    }

#ifndef __EMX__ /* Don't use a SIGCHLD handler for OS/2 */
#if defined(MAKE_JOBSERVER) || !defined(HAVE_WAIT_NOHANG)
  /* Set up to handle children dying.  This must be done before
     reading in the makefiles so that 'shell' function calls will work.

     If we don't have a hanging wait we have to fall back to old, broken
     functionality here and rely on the signal handler and counting
     children.

     If we're using the jobs pipe we need a signal handler so that
     SIGCHLD is not ignored; we need it to interrupt the read(2) of the
     jobserver pipe in job.c if we're waiting for a token.

     If none of these are true, we don't need a signal handler at all.  */
  {
    RETSIGTYPE child_handler (int sig);
# if defined SIGCHLD
    bsd_signal (SIGCHLD, child_handler);
# endif
# if defined SIGCLD && SIGCLD != SIGCHLD
    bsd_signal (SIGCLD, child_handler);
# endif
  }
#endif
#endif

  /* Let the user send us SIGUSR1 to toggle the -d flag during the run.  */
#ifdef SIGUSR1
  bsd_signal (SIGUSR1, debug_signal_handler);
#endif

  /* Define the initial list of suffixes for old-style rules.  */
  set_default_suffixes ();

  /* Define the file rules for the built-in suffix rules.  These will later
     be converted into pattern rules.  We used to do this in
     install_default_implicit_rules, but since that happens after reading
     makefiles, it results in the built-in pattern rules taking precedence
     over makefile-specified suffix rules, which is wrong.  */
  install_default_suffix_rules ();

  /* Define some internal and special variables.  */
  define_automatic_variables ();

  /* Set up the MAKEFLAGS and MFLAGS variables for makefiles to see.
     Initialize it to be exported but allow the makefile to reset it.  */
  define_makeflags (0, 0)->export = v_export;

  /* Define the default variables.  */
  define_default_variables ();

  default_file = enter_file (strcache_add (".DEFAULT"));

  default_goal_var = define_variable_cname (".DEFAULT_GOAL", "", o_file, 0);

  /* Evaluate all strings provided with --eval.
     Also set up the $(-*-eval-flags-*-) variable.  */

  if (eval_strings)
    {
      char *p, *value;
      unsigned int i;
      unsigned int len = (CSTRLEN ("--eval=") + 1) * eval_strings->idx;

      for (i = 0; i < eval_strings->idx; ++i)
        {
          p = xstrdup (eval_strings->list[i]);
          len += 2 * strlen (p);
          eval_buffer (p, NULL);
          free (p);
        }

      p = value = alloca (len);
      for (i = 0; i < eval_strings->idx; ++i)
        {
          strcpy (p, "--eval=");
          p += CSTRLEN ("--eval=");
          p = quote_for_env (p, eval_strings->list[i]);
          *(p++) = ' ';
        }
      p[-1] = '\0';

      define_variable_cname ("-*-eval-flags-*-", value, o_automatic, 0);
    }

  /* Read all the makefiles.  */

  read_files = read_all_makefiles (makefiles == 0 ? 0 : makefiles->list);

#ifdef WINDOWS32
  /* look one last time after reading all Makefiles */
  if (no_default_sh_exe)
    no_default_sh_exe = !find_and_set_default_shell (NULL);
#endif /* WINDOWS32 */

#if defined (__MSDOS__) || defined (__EMX__) || defined (VMS)
  /* We need to know what kind of shell we will be using.  */
  {
    extern int _is_unixy_shell (const char *_path);
    struct variable *shv = lookup_variable (STRING_SIZE_TUPLE ("SHELL"));
    extern int unixy_shell;
    extern const char *default_shell;

    if (shv && *shv->value)
      {
        char *shell_path = recursively_expand (shv);

        if (shell_path && _is_unixy_shell (shell_path))
          unixy_shell = 1;
        else
          unixy_shell = 0;
        if (shell_path)
          default_shell = shell_path;
      }
  }
#endif /* __MSDOS__ || __EMX__ */

  {
    int old_builtin_rules_flag = no_builtin_rules_flag;
    int old_builtin_variables_flag = no_builtin_variables_flag;

    /* Decode switches again, for variables set by the makefile.  */
    decode_env_switches (STRING_SIZE_TUPLE ("GNUMAKEFLAGS"));

    /* Clear GNUMAKEFLAGS to avoid duplication.  */
    define_variable_cname ("GNUMAKEFLAGS", "", o_override, 0);

    decode_env_switches (STRING_SIZE_TUPLE ("MAKEFLAGS"));
#if 0
    decode_env_switches (STRING_SIZE_TUPLE ("MFLAGS"));
#endif

    /* Reset in case the switches changed our mind.  */
    syncing = (output_sync == OUTPUT_SYNC_LINE
               || output_sync == OUTPUT_SYNC_TARGET);

    if (make_sync.syncout && ! syncing)
      output_close (&make_sync);

    make_sync.syncout = syncing;
    OUTPUT_SET (&make_sync);

    /* If we've disabled builtin rules, get rid of them.  */
    if (no_builtin_rules_flag && ! old_builtin_rules_flag)
      {
        if (suffix_file->builtin)
          {
            free_dep_chain (suffix_file->deps);
            suffix_file->deps = 0;
          }
        define_variable_cname ("SUFFIXES", "", o_default, 0);
      }

    /* If we've disabled builtin variables, get rid of them.  */
    if (no_builtin_variables_flag && ! old_builtin_variables_flag)
      undefine_default_variables ();
  }

#if defined (__MSDOS__) || defined (__EMX__) || defined (VMS)
  if (job_slots != 1
# ifdef __EMX__
      && _osmode != OS2_MODE /* turn off -j if we are in DOS mode */
# endif
      )
    {
      O (error, NILF,
         _("Parallel jobs (-j) are not supported on this platform."));
      O (error, NILF, _("Resetting to single job (-j1) mode."));
      job_slots = 1;
    }
#endif

#ifdef MAKE_JOBSERVER
  /* If we have >1 slot but no jobserver-fds, then we're a top-level make.
     Set up the pipe and install the fds option for our children.  */

  if (job_slots > 1)
    {
#ifdef WINDOWS32
      /* sub_proc.c cannot wait for more than MAXIMUM_WAIT_OBJECTS objects
       * and one of them is the job-server semaphore object.  Limit the
       * number of available job slots to (MAXIMUM_WAIT_OBJECTS - 1). */

      if (job_slots >= MAXIMUM_WAIT_OBJECTS)
        {
          job_slots = MAXIMUM_WAIT_OBJECTS - 1;
          DB (DB_JOBS, (_("Jobserver slots limited to %d\n"), job_slots));
        }

      if (! create_jobserver_semaphore (job_slots - 1))
        {
          DWORD err = GetLastError ();
          const char *estr = map_windows32_error_to_string (err);
          ONS (fatal, NILF,
               _("creating jobserver semaphore: (Error %ld: %s)"), err, estr);
        }
#else
      char c = '+';

      if (pipe (job_fds) < 0 || (job_rfd = dup (job_fds[0])) < 0)
        pfatal_with_name (_("creating jobs pipe"));
#endif

      /* Every make assumes that it always has one job it can run.  For the
         submakes it's the token they were given by their parent.  For the
         top make, we just subtract one from the number the user wants.  We
         want job_slots to be 0 to indicate we're using the jobserver.  */

      master_job_slots = job_slots;

#ifdef WINDOWS32
      /* We're using the jobserver so set job_slots to 0. */
      job_slots = 0;
#else
      while (--job_slots)
        {
          int r;

          EINTRLOOP (r, write (job_fds[1], &c, 1));
          if (r != 1)
            pfatal_with_name (_("init jobserver pipe"));
        }
#endif

      /* Fill in the jobserver_fds for our children.  */

#ifdef WINDOWS32
      jobserver_fds = xmalloc (MAX_PATH + 1);
      strcpy (jobserver_fds, get_jobserver_semaphore_name ());
#else
      jobserver_fds = xmalloc ((INTSTR_LENGTH * 2) + 2);
      sprintf (jobserver_fds, "%d,%d", job_fds[0], job_fds[1]);
#endif
    }
#endif

#ifndef MAKE_SYMLINKS
  if (check_symlink_flag)
    {
      O (error, NILF, _("Symbolic links not supported: disabling -L."));
      check_symlink_flag = 0;
    }
#endif

  /* Set up MAKEFLAGS and MFLAGS again, so they will be right.  */

  define_makeflags (1, 0);

  /* Make each 'struct dep' point at the 'struct file' for the file
     depended on.  Also do magic for special targets.  */

  snap_deps ();

  /* Convert old-style suffix rules to pattern rules.  It is important to
     do this before installing the built-in pattern rules below, so that
     makefile-specified suffix rules take precedence over built-in pattern
     rules.  */

  convert_to_pattern ();

  /* Install the default implicit pattern rules.
     This used to be done before reading the makefiles.
     But in that case, built-in pattern rules were in the chain
     before user-defined ones, so they matched first.  */

  install_default_implicit_rules ();

  /* Compute implicit rule limits.  */

  count_implicit_rule_limits ();

  /* Construct the listings of directories in VPATH lists.  */

  build_vpath_lists ();

  /* Mark files given with -o flags as very old and as having been updated
     already, and files given with -W flags as brand new (time-stamp as far
     as possible into the future).  If restarts is set we'll do -W later.  */

  if (old_files != 0)
    {
      const char **p;
      for (p = old_files->list; *p != 0; ++p)
        {
          struct file *f = enter_file (*p);
          f->last_mtime = f->mtime_before_update = OLD_MTIME;
          f->updated = 1;
          f->update_status = us_success;
          f->command_state = cs_finished;
        }
    }

  if (!restarts && new_files != 0)
    {
      const char **p;
      for (p = new_files->list; *p != 0; ++p)
        {
          struct file *f = enter_file (*p);
          f->last_mtime = f->mtime_before_update = NEW_MTIME;
        }
    }

  /* Initialize the remote job module.  */
  remote_setup ();

  /* Dump any output we've collected.  */

  OUTPUT_UNSET ();
  output_close (&make_sync);

  if (read_files != 0)
    {
      /* Update any makefiles if necessary.  */

      FILE_TIMESTAMP *makefile_mtimes = 0;
      unsigned int mm_idx = 0;
      char **aargv = NULL;
      const char **nargv;
      int nargc;
      int orig_db_level = db_level;
      enum update_status status;

      if (! ISDB (DB_MAKEFILES))
        db_level = DB_NONE;

      DB (DB_BASIC, (_("Updating makefiles....\n")));

      /* Remove any makefiles we don't want to try to update.
         Also record the current modtimes so we can compare them later.  */
      {
        register struct dep *d, *last;
        last = 0;
        d = read_files;
        while (d != 0)
          {
            struct file *f = d->file;
            if (f->double_colon)
              for (f = f->double_colon; f != NULL; f = f->prev)
                {
                  if (f->deps == 0 && f->cmds != 0)
                    {
                      /* This makefile is a :: target with commands, but
                         no dependencies.  So, it will always be remade.
                         This might well cause an infinite loop, so don't
                         try to remake it.  (This will only happen if
                         your makefiles are written exceptionally
                         stupidly; but if you work for Athena, that's how
                         you write your makefiles.)  */

                      DB (DB_VERBOSE,
                          (_("Makefile '%s' might loop; not remaking it.\n"),
                           f->name));

                      if (last == 0)
                        read_files = d->next;
                      else
                        last->next = d->next;

                      /* Free the storage.  */
                      free_dep (d);

                      d = last == 0 ? read_files : last->next;

                      break;
                    }
                }
            if (f == NULL || !f->double_colon)
              {
                makefile_mtimes = xrealloc (makefile_mtimes,
                                            (mm_idx+1)
                                            * sizeof (FILE_TIMESTAMP));
                makefile_mtimes[mm_idx++] = file_mtime_no_search (d->file);
                last = d;
                d = d->next;
              }
          }
      }

      /* Set up 'MAKEFLAGS' specially while remaking makefiles.  */
      define_makeflags (1, 1);

      rebuilding_makefiles = 1;
      status = update_goal_chain (read_files);
      rebuilding_makefiles = 0;

      switch (status)
        {
        case us_question:
          /* The only way this can happen is if the user specified -q and asked
           * for one of the makefiles to be remade as a target on the command
           * line.  Since we're not actually updating anything with -q we can
           * treat this as "did nothing".
           */

        case us_none:
          /* Did nothing.  */
          break;

        case us_failed:
          /* Failed to update.  Figure out if we care.  */
          {
            /* Nonzero if any makefile was successfully remade.  */
            int any_remade = 0;
            /* Nonzero if any makefile we care about failed
               in updating or could not be found at all.  */
            int any_failed = 0;
            unsigned int i;
            struct dep *d;

            for (i = 0, d = read_files; d != 0; ++i, d = d->next)
              {
                /* Reset the considered flag; we may need to look at the file
                   again to print an error.  */
                d->file->considered = 0;

                if (d->file->updated)
                  {
                    /* This makefile was updated.  */
                    if (d->file->update_status == us_success)
                      {
                        /* It was successfully updated.  */
                        any_remade |= (file_mtime_no_search (d->file)
                                       != makefile_mtimes[i]);
                      }
                    else if (! (d->changed & RM_DONTCARE))
                      {
                        FILE_TIMESTAMP mtime;
                        /* The update failed and this makefile was not
                           from the MAKEFILES variable, so we care.  */
                        OS (error, NILF, _("Failed to remake makefile '%s'."),
                            d->file->name);
                        mtime = file_mtime_no_search (d->file);
                        any_remade |= (mtime != NONEXISTENT_MTIME
                                       && mtime != makefile_mtimes[i]);
                        makefile_status = MAKE_FAILURE;
                      }
                  }
                else
                  /* This makefile was not found at all.  */
                  if (! (d->changed & RM_DONTCARE))
                    {
                      const char *dnm = dep_name (d);
                      size_t l = strlen (dnm);

                      /* This is a makefile we care about.  See how much.  */
                      if (d->changed & RM_INCLUDED)
                        /* An included makefile.  We don't need to die, but we
                           do want to complain.  */
                        error (NILF, l,
                               _("Included makefile '%s' was not found."), dnm);
                      else
                        {
                          /* A normal makefile.  We must die later.  */
                          error (NILF, l,
                                 _("Makefile '%s' was not found"), dnm);
                          any_failed = 1;
                        }
                    }
              }
            /* Reset this to empty so we get the right error message below.  */
            read_files = 0;

            if (any_remade)
              goto re_exec;
            if (any_failed)
              die (MAKE_FAILURE);
            break;
          }

        case us_success:
        re_exec:
          /* Updated successfully.  Re-exec ourselves.  */

          remove_intermediates (0);

          if (print_data_base_flag)
            print_data_base ();

          clean_jobserver (0);

          if (makefiles != 0)
            {
              /* These names might have changed.  */
              int i, j = 0;
              for (i = 1; i < argc; ++i)
                if (strneq (argv[i], "-f", 2)) /* XXX */
                  {
                    if (argv[i][2] == '\0')
                      /* This cast is OK since we never modify argv.  */
                      argv[++i] = (char *) makefiles->list[j];
                    else
                      argv[i] = xstrdup (concat (2, "-f", makefiles->list[j]));
                    ++j;
                  }
            }

          /* Add -o option for the stdin temporary file, if necessary.  */
          nargc = argc;
          if (stdin_nm)
            {
              void *m = xmalloc ((nargc + 2) * sizeof (char *));
              aargv = m;
              memcpy (aargv, argv, argc * sizeof (char *));
              aargv[nargc++] = xstrdup (concat (2, "-o", stdin_nm));
              aargv[nargc] = 0;
              nargv = m;
            }
          else
            nargv = (const char**)argv;

          if (directories != 0 && directories->idx > 0)
            {
              int bad = 1;
              if (directory_before_chdir != 0)
                {
                  if (chdir (directory_before_chdir) < 0)
                      perror_with_name ("chdir", "");
                  else
                    bad = 0;
                }
              if (bad)
                O (fatal, NILF,
                   _("Couldn't change back to original directory."));
            }

          ++restarts;

          /* If we're re-exec'ing the first make, put back the number of
             job slots so define_makefiles() will get it right.  */
          if (master_job_slots)
            job_slots = master_job_slots;

          if (ISDB (DB_BASIC))
            {
              const char **p;
              printf (_("Re-executing[%u]:"), restarts);
              for (p = nargv; *p != 0; ++p)
                printf (" %s", *p);
              putchar ('\n');
            }

#ifndef _AMIGA
          {
            char **p;
            for (p = environ; *p != 0; ++p)
              {
                if (strneq (*p, MAKELEVEL_NAME "=", MAKELEVEL_LENGTH+1))
                  {
                    *p = alloca (40);
                    sprintf (*p, "%s=%u", MAKELEVEL_NAME, makelevel);
#ifdef VMS
                    vms_putenv_symbol (*p);
#endif
                  }
                else if (strneq (*p, "MAKE_RESTARTS=", CSTRLEN ("MAKE_RESTARTS=")))
                  {
                    *p = alloca (40);
                    sprintf (*p, "MAKE_RESTARTS=%s%u",
                             OUTPUT_IS_TRACED () ? "-" : "", restarts);
                    restarts = 0;
                  }
              }
          }
#else /* AMIGA */
          {
            char buffer[256];

            sprintf (buffer, "%u", makelevel);
            SetVar (MAKELEVEL_NAME, buffer, -1, GVF_GLOBAL_ONLY);

            sprintf (buffer, "%s%u", OUTPUT_IS_TRACED () ? "-" : "", restarts);
            SetVar ("MAKE_RESTARTS", buffer, -1, GVF_GLOBAL_ONLY);
            restarts = 0;
          }
#endif

          /* If we didn't set the restarts variable yet, add it.  */
          if (restarts)
            {
              char *b = alloca (40);
              sprintf (b, "MAKE_RESTARTS=%s%u",
                       OUTPUT_IS_TRACED () ? "-" : "", restarts);
              putenv (b);
            }

          fflush (stdout);
          fflush (stderr);

          /* Close the dup'd jobserver pipe if we opened one.  */
          if (job_rfd >= 0)
            close (job_rfd);

#ifdef _AMIGA
          exec_command (nargv);
          exit (0);
#elif defined (__EMX__)
          {
            /* It is not possible to use execve() here because this
               would cause the parent process to be terminated with
               exit code 0 before the child process has been terminated.
               Therefore it may be the best solution simply to spawn the
               child process including all file handles and to wait for its
               termination. */
            int pid;
            int r;
            pid = child_execute_job (FD_STDIN, FD_STDOUT, FD_STDERR,
                                     nargv, environ);

            /* is this loop really necessary? */
            do {
              pid = wait (&r);
            } while (pid <= 0);
            /* use the exit code of the child process */
            exit (WIFEXITED(r) ? WEXITSTATUS(r) : EXIT_FAILURE);
          }
#else
          exec_command ((char **)nargv, environ);
#endif
          free (aargv);
          break;
        }

      db_level = orig_db_level;

      /* Free the makefile mtimes.  */
      free (makefile_mtimes);
    }

  /* Set up 'MAKEFLAGS' again for the normal targets.  */
  define_makeflags (1, 0);

  /* Set always_make_flag if -B was given.  */
  always_make_flag = always_make_set;

  /* If restarts is set we haven't set up -W files yet, so do that now.  */
  if (restarts && new_files != 0)
    {
      const char **p;
      for (p = new_files->list; *p != 0; ++p)
        {
          struct file *f = enter_file (*p);
          f->last_mtime = f->mtime_before_update = NEW_MTIME;
        }
    }

  /* If there is a temp file from reading a makefile from stdin, get rid of
     it now.  */
  if (stdin_nm && unlink (stdin_nm) < 0 && errno != ENOENT)
    perror_with_name (_("unlink (temporary file): "), stdin_nm);

  /* If there were no command-line goals, use the default.  */
  if (goals == 0)
    {
      char *p;

      if (default_goal_var->recursive)
        p = variable_expand (default_goal_var->value);
      else
        {
          p = variable_buffer_output (variable_buffer, default_goal_var->value,
                                      strlen (default_goal_var->value));
          *p = '\0';
          p = variable_buffer;
        }

      if (*p != '\0')
        {
          struct file *f = lookup_file (p);

          /* If .DEFAULT_GOAL is a non-existent target, enter it into the
             table and let the standard logic sort it out. */
          if (f == 0)
            {
              struct nameseq *ns;

              ns = PARSE_SIMPLE_SEQ (&p, struct nameseq);
              if (ns)
                {
                  /* .DEFAULT_GOAL should contain one target. */
                  if (ns->next != 0)
                    O (fatal, NILF,
                       _(".DEFAULT_GOAL contains more than one target"));

                  f = enter_file (strcache_add (ns->name));

                  ns->name = 0; /* It was reused by enter_file(). */
                  free_ns_chain (ns);
                }
            }

          if (f)
            {
              goals = alloc_dep ();
              goals->file = f;
            }
        }
    }
  else
    lastgoal->next = 0;


  if (!goals)
    {
      if (read_files == 0)
        O (fatal, NILF, _("No targets specified and no makefile found"));

      O (fatal, NILF, _("No targets"));
    }

  /* Update the goals.  */

  DB (DB_BASIC, (_("Updating goal targets....\n")));

  {
    switch (update_goal_chain (goals))
    {
      case us_none:
        /* Nothing happened.  */
        /* FALLTHROUGH */
      case us_success:
        /* Keep the previous result.  */
        break;
      case us_question:
        /* We are under -q and would run some commands.  */
        makefile_status = MAKE_TROUBLE;
        break;
      case us_failed:
        /* Updating failed.  POSIX.2 specifies exit status >1 for this; */
        makefile_status = MAKE_FAILURE;
        break;
    }

    /* If we detected some clock skew, generate one last warning */
    if (clock_skew_detected)
      O (error, NILF,
         _("warning:  Clock skew detected.  Your build may be incomplete."));

    /* Exit.  */
    die (makefile_status);
  }

  /* NOTREACHED */
  exit (MAKE_SUCCESS);
}

/* Parsing of arguments, decoding of switches.  */

static char options[1 + sizeof (switches) / sizeof (switches[0]) * 3];
static struct option long_options[(sizeof (switches) / sizeof (switches[0])) +
                                  (sizeof (long_option_aliases) /
                                   sizeof (long_option_aliases[0]))];

/* Fill in the string and vector for getopt.  */
static void
init_switches (void)
{
  char *p;
  unsigned int c;
  unsigned int i;

  if (options[0] != '\0')
    /* Already done.  */
    return;

  p = options;

  /* Return switch and non-switch args in order, regardless of
     POSIXLY_CORRECT.  Non-switch args are returned as option 1.  */
  *p++ = '-';

  for (i = 0; switches[i].c != '\0'; ++i)
    {
      long_options[i].name = (switches[i].long_name == 0 ? "" :
                              switches[i].long_name);
      long_options[i].flag = 0;
      long_options[i].val = switches[i].c;
      if (short_option (switches[i].c))
        *p++ = switches[i].c;
      switch (switches[i].type)
        {
        case flag:
        case flag_off:
        case ignore:
          long_options[i].has_arg = no_argument;
          break;

        case string:
        case strlist:
        case filename:
        case positive_int:
        case floating:
          if (short_option (switches[i].c))
            *p++ = ':';
          if (switches[i].noarg_value != 0)
            {
              if (short_option (switches[i].c))
                *p++ = ':';
              long_options[i].has_arg = optional_argument;
            }
          else
            long_options[i].has_arg = required_argument;
          break;
        }
    }
  *p = '\0';
  for (c = 0; c < (sizeof (long_option_aliases) /
                   sizeof (long_option_aliases[0]));
       ++c)
    long_options[i++] = long_option_aliases[c];
  long_options[i].name = 0;
}


/* Non-option argument.  It might be a variable definition.  */
static void
handle_non_switch_argument (const char *arg, int env)
{
  struct variable *v;

  if (arg[0] == '-' && arg[1] == '\0')
    /* Ignore plain '-' for compatibility.  */
    return;

#ifdef VMS
  {
    /* VMS DCL quoting can result in foo="bar baz" showing up here.
       Need to remove the double quotes from the value. */
    char * eq_ptr;
    char * new_arg;
    eq_ptr = strchr (arg, '=');
    if ((eq_ptr != NULL) && (eq_ptr[1] == '"'))
      {
         int len;
         int seg1;
         int seg2;
         len = strlen(arg);
         new_arg = alloca(len);
         seg1 = eq_ptr - arg + 1;
         strncpy(new_arg, arg, (seg1));
         seg2 = len - seg1 - 1;
         strncpy(&new_arg[seg1], &eq_ptr[2], seg2);
         new_arg[seg1 + seg2] = 0;
         if (new_arg[seg1 + seg2 - 1] == '"')
           new_arg[seg1 + seg2 - 1] = 0;
         arg = new_arg;
      }
  }
#endif
  v = try_variable_definition (0, arg, o_command, 0);
  if (v != 0)
    {
      /* It is indeed a variable definition.  If we don't already have this
         one, record a pointer to the variable for later use in
         define_makeflags.  */
      struct command_variable *cv;

      for (cv = command_variables; cv != 0; cv = cv->next)
        if (cv->variable == v)
          break;

      if (! cv)
        {
          cv = xmalloc (sizeof (*cv));
          cv->variable = v;
          cv->next = command_variables;
          command_variables = cv;
        }
    }
  else if (! env)
    {
      /* Not an option or variable definition; it must be a goal
         target!  Enter it as a file and add it to the dep chain of
         goals.  */
      struct file *f = enter_file (strcache_add (expand_command_line_file (arg)));
      f->cmd_target = 1;

      if (goals == 0)
        {
          goals = alloc_dep ();
          lastgoal = goals;
        }
      else
        {
          lastgoal->next = alloc_dep ();
          lastgoal = lastgoal->next;
        }

      lastgoal->file = f;

      {
        /* Add this target name to the MAKECMDGOALS variable. */
        struct variable *gv;
        const char *value;

        gv = lookup_variable (STRING_SIZE_TUPLE ("MAKECMDGOALS"));
        if (gv == 0)
          value = f->name;
        else
          {
            /* Paste the old and new values together */
            unsigned int oldlen, newlen;
            char *vp;

            oldlen = strlen (gv->value);
            newlen = strlen (f->name);
            vp = alloca (oldlen + 1 + newlen + 1);
            memcpy (vp, gv->value, oldlen);
            vp[oldlen] = ' ';
            memcpy (&vp[oldlen + 1], f->name, newlen + 1);
            value = vp;
          }
        define_variable_cname ("MAKECMDGOALS", value, o_default, 0);
      }
    }
}

/* Print a nice usage method.  */

static void
print_usage (int bad)
{
  const char *const *cpp;
  FILE *usageto;

  if (print_version_flag)
    print_version ();

  usageto = bad ? stderr : stdout;

  fprintf (usageto, _("Usage: %s [options] [target] ...\n"), program);

  for (cpp = usage; *cpp; ++cpp)
    fputs (_(*cpp), usageto);

  if (!remote_description || *remote_description == '\0')
    fprintf (usageto, _("\nThis program built for %s\n"), make_host);
  else
    fprintf (usageto, _("\nThis program built for %s (%s)\n"),
             make_host, remote_description);

  fprintf (usageto, _("Report bugs to <bug-make@gnu.org>\n"));
}

/* Decode switches from ARGC and ARGV.
   They came from the environment if ENV is nonzero.  */

static void
decode_switches (int argc, const char **argv, int env)
{
  int bad = 0;
  register const struct command_switch *cs;
  register struct stringlist *sl;
  register int c;

  /* getopt does most of the parsing for us.
     First, get its vectors set up.  */

  init_switches ();

  /* Let getopt produce error messages for the command line,
     but not for options from the environment.  */
  opterr = !env;
  /* Reset getopt's state.  */
  optind = 0;

  while (optind < argc)
    {
      const char *coptarg;

      /* Parse the next argument.  */
      c = getopt_long (argc, (char*const*)argv, options, long_options, NULL);
      coptarg = optarg;
      if (c == EOF)
        /* End of arguments, or "--" marker seen.  */
        break;
      else if (c == 1)
        /* An argument not starting with a dash.  */
        handle_non_switch_argument (coptarg, env);
      else if (c == '?')
        /* Bad option.  We will print a usage message and die later.
           But continue to parse the other options so the user can
           see all he did wrong.  */
        bad = 1;
      else
        for (cs = switches; cs->c != '\0'; ++cs)
          if (cs->c == c)
            {
              /* Whether or not we will actually do anything with
                 this switch.  We test this individually inside the
                 switch below rather than just once outside it, so that
                 options which are to be ignored still consume args.  */
              int doit = !env || cs->env;

              switch (cs->type)
                {
                default:
                  abort ();

                case ignore:
                  break;

                case flag:
                case flag_off:
                  if (doit)
                    *(int *) cs->value_ptr = cs->type == flag;
                  break;

                case string:
                case strlist:
                case filename:
                  if (!doit)
                    break;

                  if (! coptarg)
                    coptarg = xstrdup (cs->noarg_value);
                  else if (*coptarg == '\0')
                    {
                      char opt[2] = "c";
                      const char *op = opt;

                      if (short_option (cs->c))
                        opt[0] = cs->c;
                      else
                        op = cs->long_name;

                      error (NILF, strlen (op),
                             _("the '%s%s' option requires a non-empty string argument"),
                             short_option (cs->c) ? "-" : "--", op);
                      bad = 1;
                      break;
                    }

                  if (cs->type == string)
                    {
                      char **val = (char **)cs->value_ptr;
                      free (*val);
                      *val = xstrdup (coptarg);
                      break;
                    }

                  sl = *(struct stringlist **) cs->value_ptr;
                  if (sl == 0)
                    {
                      sl = xmalloc (sizeof (struct stringlist));
                      sl->max = 5;
                      sl->idx = 0;
                      sl->list = xmalloc (5 * sizeof (char *));
                      *(struct stringlist **) cs->value_ptr = sl;
                    }
                  else if (sl->idx == sl->max - 1)
                    {
                      sl->max += 5;
                      /* MSVC erroneously warns without a cast here.  */
                      sl->list = xrealloc ((void *)sl->list,
                                           sl->max * sizeof (char *));
                    }
                  if (cs->type == filename)
                    sl->list[sl->idx++] = expand_command_line_file (coptarg);
                  else
                    sl->list[sl->idx++] = xstrdup (coptarg);
                  sl->list[sl->idx] = 0;
                  break;

                case positive_int:
                  /* See if we have an option argument; if we do require that
                     it's all digits, not something like "10foo".  */
                  if (coptarg == 0 && argc > optind)
                    {
                      const char *cp;
                      for (cp=argv[optind]; ISDIGIT (cp[0]); ++cp)
                        ;
                      if (cp[0] == '\0')
                        coptarg = argv[optind++];
                    }

                  if (!doit)
                    break;

                  if (coptarg)
                    {
                      int i = atoi (coptarg);
                      const char *cp;

                      /* Yes, I realize we're repeating this in some cases.  */
                      for (cp = coptarg; ISDIGIT (cp[0]); ++cp)
                        ;

                      if (i < 1 || cp[0] != '\0')
                        {
                          error (NILF, 0,
                                 _("the '-%c' option requires a positive integer argument"),
                                 cs->c);
                          bad = 1;
                        }
                      else
                        *(unsigned int *) cs->value_ptr = i;
                    }
                  else
                    *(unsigned int *) cs->value_ptr
                      = *(unsigned int *) cs->noarg_value;
                  break;

#ifndef NO_FLOAT
                case floating:
                  if (coptarg == 0 && optind < argc
                      && (ISDIGIT (argv[optind][0]) || argv[optind][0] == '.'))
                    coptarg = argv[optind++];

                  if (doit)
                    *(double *) cs->value_ptr
                      = (coptarg != 0 ? atof (coptarg)
                         : *(double *) cs->noarg_value);

                  break;
#endif
                }

              /* We've found the switch.  Stop looking.  */
              break;
            }
    }

  /* There are no more options according to getting getopt, but there may
     be some arguments left.  Since we have asked for non-option arguments
     to be returned in order, this only happens when there is a "--"
     argument to prevent later arguments from being options.  */
  while (optind < argc)
    handle_non_switch_argument (argv[optind++], env);

  if (!env && (bad || print_usage_flag))
    {
      print_usage (bad);
      die (bad ? MAKE_FAILURE : MAKE_SUCCESS);
    }

  /* If there are any options that need to be decoded do it now.  */
  decode_debug_flags ();
  decode_output_sync_flags ();
}

/* Decode switches from environment variable ENVAR (which is LEN chars long).
   We do this by chopping the value into a vector of words, prepending a
   dash to the first word if it lacks one, and passing the vector to
   decode_switches.  */

static void
decode_env_switches (const char *envar, unsigned int len)
{
  char *varref = alloca (2 + len + 2);
  char *value, *p, *buf;
  int argc;
  const char **argv;

  /* Get the variable's value.  */
  varref[0] = '$';
  varref[1] = '(';
  memcpy (&varref[2], envar, len);
  varref[2 + len] = ')';
  varref[2 + len + 1] = '\0';
  value = variable_expand (varref);

  /* Skip whitespace, and check for an empty value.  */
  value = next_token (value);
  len = strlen (value);
  if (len == 0)
    return;

  /* Allocate a vector that is definitely big enough.  */
  argv = alloca ((1 + len + 1) * sizeof (char *));

  /* getopt will look at the arguments starting at ARGV[1].
     Prepend a spacer word.  */
  argv[0] = 0;
  argc = 1;

  /* We need a buffer to copy the value into while we split it into words
     and unquote it.  Set up in case we need to prepend a dash later.  */
  buf = alloca (1 + len + 1);
  buf[0] = '-';
  p = buf+1;
  argv[argc] = p;
  while (*value != '\0')
    {
      if (*value == '\\' && value[1] != '\0')
        ++value;                /* Skip the backslash.  */
      else if (isblank ((unsigned char)*value))
        {
          /* End of the word.  */
          *p++ = '\0';
          argv[++argc] = p;
          do
            ++value;
          while (isblank ((unsigned char)*value));
          continue;
        }
      *p++ = *value++;
    }
  *p = '\0';
  argv[++argc] = 0;
  assert (p < buf + len + 2);

  if (argv[1][0] != '-' && strchr (argv[1], '=') == 0)
    /* The first word doesn't start with a dash and isn't a variable
       definition, so add a dash.  */
    argv[1] = buf;

  /* Parse those words.  */
  decode_switches (argc, argv, 1);
}

/* Quote the string IN so that it will be interpreted as a single word with
   no magic by decode_env_switches; also double dollar signs to avoid
   variable expansion in make itself.  Write the result into OUT, returning
   the address of the next character to be written.
   Allocating space for OUT twice the length of IN is always sufficient.  */

static char *
quote_for_env (char *out, const char *in)
{
  while (*in != '\0')
    {
      if (*in == '$')
        *out++ = '$';
      else if (isblank ((unsigned char)*in) || *in == '\\')
        *out++ = '\\';
      *out++ = *in++;
    }

  return out;
}

/* Define the MAKEFLAGS and MFLAGS variables to reflect the settings of the
   command switches.  Include options with args if ALL is nonzero.
   Don't include options with the 'no_makefile' flag set if MAKEFILE.  */

static struct variable *
define_makeflags (int all, int makefile)
{
  const char ref[] = "$(MAKEOVERRIDES)";
  const char posixref[] = "$(-*-command-variables-*-)";
  const char evalref[] = "$(-*-eval-flags-*-)";
  const struct command_switch *cs;
  char *flagstring;
  char *p;

  /* We will construct a linked list of 'struct flag's describing
     all the flags which need to go in MAKEFLAGS.  Then, once we
     know how many there are and their lengths, we can put them all
     together in a string.  */

  struct flag
    {
      struct flag *next;
      const struct command_switch *cs;
      const char *arg;
    };
  struct flag *flags = 0;
  struct flag *last = 0;
  unsigned int flagslen = 0;
#define ADD_FLAG(ARG, LEN) \
  do {                                                                        \
    struct flag *new = alloca (sizeof (struct flag));                         \
    new->cs = cs;                                                             \
    new->arg = (ARG);                                                         \
    new->next = 0;                                                            \
    if (! flags)                                                              \
      flags = new;                                                            \
    else                                                                      \
      last->next = new;                                                       \
    last = new;                                                               \
    if (new->arg == 0)                                                        \
      /* Just a single flag letter: " -x"  */                                 \
      flagslen += 3;                                                          \
    else                                                                      \
      /* " -xfoo", plus space to escape "foo".  */                            \
      flagslen += 1 + 1 + 1 + (3 * (LEN));                                    \
    if (!short_option (cs->c))                                                \
      /* This switch has no single-letter version, so we use the long.  */    \
      flagslen += 2 + strlen (cs->long_name);                                 \
  } while (0)

  for (cs = switches; cs->c != '\0'; ++cs)
    if (cs->toenv && (!makefile || !cs->no_makefile))
      switch (cs->type)
        {
        case ignore:
          break;

        case flag:
        case flag_off:
          if (!*(int *) cs->value_ptr == (cs->type == flag_off)
              && (cs->default_value == 0
                  || *(int *) cs->value_ptr != *(int *) cs->default_value))
            ADD_FLAG (0, 0);
          break;

        case positive_int:
          if (all)
            {
              if ((cs->default_value != 0
                   && (*(unsigned int *) cs->value_ptr
                       == *(unsigned int *) cs->default_value)))
                break;
              else if (cs->noarg_value != 0
                       && (*(unsigned int *) cs->value_ptr ==
                           *(unsigned int *) cs->noarg_value))
                ADD_FLAG ("", 0); /* Optional value omitted; see below.  */
              else
                {
                  char *buf = alloca (30);
                  sprintf (buf, "%u", *(unsigned int *) cs->value_ptr);
                  ADD_FLAG (buf, strlen (buf));
                }
            }
          break;

#ifndef NO_FLOAT
        case floating:
          if (all)
            {
              if (cs->default_value != 0
                  && (*(double *) cs->value_ptr
                      == *(double *) cs->default_value))
                break;
              else if (cs->noarg_value != 0
                       && (*(double *) cs->value_ptr
                           == *(double *) cs->noarg_value))
                ADD_FLAG ("", 0); /* Optional value omitted; see below.  */
              else
                {
                  char *buf = alloca (100);
                  sprintf (buf, "%g", *(double *) cs->value_ptr);
                  ADD_FLAG (buf, strlen (buf));
                }
            }
          break;
#endif

        case string:
          if (all)
            {
              p = *((char **)cs->value_ptr);
              if (p)
                ADD_FLAG (p, strlen (p));
            }
          break;

        case filename:
        case strlist:
          if (all)
            {
              struct stringlist *sl = *(struct stringlist **) cs->value_ptr;
              if (sl != 0)
                {
                  unsigned int i;
                  for (i = 0; i < sl->idx; ++i)
                    ADD_FLAG (sl->list[i], strlen (sl->list[i]));
                }
            }
          break;

        default:
          abort ();
        }

#undef  ADD_FLAG

  /* Four more for the possible " -- ", plus variable references.  */
  flagslen += 4 + CSTRLEN (posixref) + 1 + CSTRLEN (evalref) + 1;

  /* Construct the value in FLAGSTRING.
     We allocate enough space for a preceding dash and trailing null.  */
  flagstring = alloca (1 + flagslen + 1);
  memset (flagstring, '\0', 1 + flagslen + 1);
  p = flagstring;

  /* Start with a dash, for MFLAGS.  */
  *p++ = '-';

  /* Add simple options as a group.  */
  while (flags != 0 && !flags->arg && short_option (flags->cs->c))
    {
      *p++ = flags->cs->c;
      flags = flags->next;
    }

  /* Now add more complex flags: ones with options and/or long names.  */
  while (flags)
    {
      *p++ = ' ';
      *p++ = '-';

      /* Add the flag letter or name to the string.  */
      if (short_option (flags->cs->c))
        *p++ = flags->cs->c;
      else
        {
          /* Long options require a double-dash.  */
          *p++ = '-';
          strcpy (p, flags->cs->long_name);
          p += strlen (p);
        }
      /* An omitted optional argument has an ARG of "".  */
      if (flags->arg && flags->arg[0] != '\0')
        {
          if (!short_option (flags->cs->c))
            /* Long options require '='.  */
            *p++ = '=';
          p = quote_for_env (p, flags->arg);
        }
      flags = flags->next;
    }

  /* If no flags at all, get rid of the initial dash.  */
  if (p == &flagstring[1])
    {
      flagstring[0] = '\0';
      p = flagstring;
    }

  /* Define MFLAGS before appending variable definitions.  Omit an initial
     empty dash.  Since MFLAGS is not parsed for flags, there is no reason to
     override any makefile redefinition.  */
  define_variable_cname ("MFLAGS",
                         flagstring + (flagstring[0] == '-' && flagstring[1] == ' ' ? 2 : 0),
                         o_env, 1);

  /* Write a reference to -*-eval-flags-*-, which contains all the --eval
     flag options.  */
  if (eval_strings)
    {
      *p++ = ' ';
      memcpy (p, evalref, CSTRLEN (evalref));
      p += CSTRLEN (evalref);
    }

  if (all && command_variables)
    {
      /* Write a reference to $(MAKEOVERRIDES), which contains all the
         command-line variable definitions.  Separate the variables from the
         switches with a "--" arg.  */

      strcpy (p, " -- ");
      p += 4;

      /* Copy in the string.  */
      if (posix_pedantic)
        {
          memcpy (p, posixref, CSTRLEN (posixref));
          p += CSTRLEN (posixref);
        }
      else
        {
          memcpy (p, ref, CSTRLEN (ref));
          p += CSTRLEN (ref);
        }
    }

  /* If there is a leading dash, omit it.  */
  if (flagstring[0] == '-')
    ++flagstring;

  /* This used to use o_env, but that lost when a makefile defined MAKEFLAGS.
     Makefiles set MAKEFLAGS to add switches, but we still want to redefine
     its value with the full set of switches.  Then we used o_file, but that
     lost when users added -e, causing a previous MAKEFLAGS env. var. to take
     precedence over the new one.  Of course, an override or command
     definition will still take precedence.  */
  return define_variable_cname ("MAKEFLAGS", flagstring,
                                env_overrides ? o_env_override : o_file, 1);
}

/* Print version information.  */

static void
print_version (void)
{
  static int printed_version = 0;

  const char *precede = print_data_base_flag ? "# " : "";

  if (printed_version)
    /* Do it only once.  */
    return;

  printf ("%sGNU Make %s\n", precede, version_string);

  if (!remote_description || *remote_description == '\0')
    printf (_("%sBuilt for %s\n"), precede, make_host);
  else
    printf (_("%sBuilt for %s (%s)\n"),
            precede, make_host, remote_description);

  /* Print this untranslated.  The coding standards recommend translating the
     (C) to the copyright symbol, but this string is going to change every
     year, and none of the rest of it should be translated (including the
     word "Copyright"), so it hardly seems worth it.  */

  printf ("%sCopyright (C) 1988-2014 Free Software Foundation, Inc.\n",
          precede);

  printf (_("%sLicense GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n\
%sThis is free software: you are free to change and redistribute it.\n\
%sThere is NO WARRANTY, to the extent permitted by law.\n"),
            precede, precede, precede);

  printed_version = 1;

  /* Flush stdout so the user doesn't have to wait to see the
     version information while make thinks about things.  */
  fflush (stdout);
}

/* Print a bunch of information about this and that.  */

static void
print_data_base ()
{
  time_t when = time ((time_t *) 0);

  print_version ();

  printf (_("\n# Make data base, printed on %s"), ctime (&when));

  print_variable_data_base ();
  print_dir_data_base ();
  print_rule_data_base ();
  print_file_data_base ();
  print_vpath_data_base ();
  strcache_print_stats ("#");

  when = time ((time_t *) 0);
  printf (_("\n# Finished Make data base on %s\n"), ctime (&when));
}

static void
clean_jobserver (int status)
{
  /* Sanity: have we written all our jobserver tokens back?  If our
     exit status is 2 that means some kind of syntax error; we might not
     have written all our tokens so do that now.  If tokens are left
     after any other error code, that's bad.  */

#ifdef WINDOWS32
  if (has_jobserver_semaphore () && jobserver_tokens)
#else
  char token = '+';

  if (job_fds[0] != -1 && jobserver_tokens)
#endif
    {
      if (status != 2)
        ON (error, NILF,
            "INTERNAL: Exiting with %u jobserver tokens (should be 0)!",
            jobserver_tokens);
      else
        /* Don't write back the "free" token */
        while (--jobserver_tokens)
          {
#ifdef WINDOWS32
            if (! release_jobserver_semaphore ())
              perror_with_name ("release_jobserver_semaphore", "");
#else
            int r;

            EINTRLOOP (r, write (job_fds[1], &token, 1));
            if (r != 1)
              perror_with_name ("write", "");
#endif
          }
    }


  /* Sanity: If we're the master, were all the tokens written back?  */

  if (master_job_slots)
    {
      /* We didn't write one for ourself, so start at 1.  */
      unsigned int tcnt = 1;

#ifdef WINDOWS32
      while (acquire_jobserver_semaphore ())
          ++tcnt;
#else
      /* Close the write side, so the read() won't hang.  */
      close (job_fds[1]);

      while (read (job_fds[0], &token, 1) == 1)
        ++tcnt;
#endif

      if (tcnt != master_job_slots)
        ONN (error, NILF,
             "INTERNAL: Exiting with %u jobserver tokens available; should be %u!",
             tcnt, master_job_slots);

#ifdef WINDOWS32
      free_jobserver_semaphore ();
#else
      close (job_fds[0]);
#endif

      /* Clean out jobserver_fds so we don't pass this information to any
         sub-makes.  Also reset job_slots since it will be put on the command
         line, not in MAKEFLAGS.  */
      job_slots = default_job_slots;
      free (jobserver_fds);
      jobserver_fds = 0;
    }
}

/* Exit with STATUS, cleaning up as necessary.  */

void
die (int status)
{
  static char dying = 0;

  if (!dying)
    {
      int err;

      dying = 1;

      if (print_version_flag)
        print_version ();

      /* Wait for children to die.  */
      err = (status != 0);
      while (job_slots_used > 0)
        reap_children (1, err);

      /* Let the remote job module clean up its state.  */
      remote_cleanup ();

      /* Remove the intermediate files.  */
      remove_intermediates (0);

      if (print_data_base_flag)
        print_data_base ();

      if (verify_flag)
        verify_file_data_base ();

      clean_jobserver (status);

      if (output_context)
        {
          /* die() might be called in a recipe output context due to an
             $(error ...) function.  */
          output_close (output_context);

          if (output_context != &make_sync)
            output_close (&make_sync);

          OUTPUT_UNSET ();
        }

      output_close (NULL);

      /* Try to move back to the original directory.  This is essential on
         MS-DOS (where there is really only one process), and on Unix it
         puts core files in the original directory instead of the -C
         directory.  Must wait until after remove_intermediates(), or unlinks
         of relative pathnames fail.  */
      if (directory_before_chdir != 0)
        {
          /* If it fails we don't care: shut up GCC.  */
          int _x UNUSED;
          _x = chdir (directory_before_chdir);
        }
    }

  exit (status);
}