make/src/main.c

/* Argument parsing and main program of GNU Make.
Copyright (C) 1988-2023 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 <https://www.gnu.org/licenses/>.  */

#include "makeint.h"
#include "os.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 "shuffle.h"

#include <assert.h>
#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

#if MK_OS_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

#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) 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,
                             enum variable_origin origin);
static void decode_env_switches (const char *envar, size_t len,
                                 enum variable_origin origin);
static char *quote_for_env (char *out, const char *in);
static void initialize_global_hash_tables (void);


/* 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).  */

static int silent_flag;
static const int default_silent_flag = 0;
static enum variable_origin silent_origin = o_default;

/* Nonzero means either -s was given, or .SILENT-with-no-deps was seen.  */

int run_silent = 0;

/* 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;

/* 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;
static const int default_keep_going_flag = 0;
static enum variable_origin keep_going_origin = o_default;

/* Nonzero means check symlink mtimes.  */

int check_symlink_flag = 0;

static int print_directory_flag = -1;
static const int default_print_directory_flag = -1;
static enum variable_origin print_directory_origin = o_default;

/* 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 for parallelism.  */

unsigned int job_slots;

#define INVALID_JOB_SLOTS (-1)
static unsigned int master_job_slots = 0;
static int arg_job_slots = INVALID_JOB_SLOTS;

static const int default_job_slots = INVALID_JOB_SLOTS;

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

static const int inf_jobs = 0;

/* Authorization for the jobserver.  */

char *jobserver_auth = NULL;

/* Style for the jobserver.  */

static char *jobserver_style = NULL;

/* Shuffle mode for goals and prerequisites.  */

static char *shuffle_mode = NULL;

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

static char *sync_mutex = NULL;

/* 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).  */
double max_load_average = -1.0;
double default_load_average = -1.0;

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

static struct stringlist *directories = 0;

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

static struct stringlist *include_dirs = 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';

/* Whether or not .NOTINTERMEDIATE with no prerequisites was given.  */
unsigned int no_intermediates;

/* Count the number of commands we've invoked, that might change something in
   the filesystem.  Start with 1 so calloc'd memory never matches.  */

unsigned long command_count = 1;

/* Remember the location of the name of the batch file from stdin.  */

static int stdin_offset = -1;


/* 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_("\
  -E STRING, --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_("\
  --jobserver-style=STYLE     Select the style of jobserver to use.\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_("\
  --shuffle[={SEED|random|reverse|none}]\n\
                              Perform shuffle of prerequisites and goals.\n"),
    N_("\
  -s, --silent, --quiet       Don't echo recipes.\n"),
    N_("\
  --no-silent                 Echo recipes (disable --silent mode).\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
  };

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

static int trace_flag = 0;

/* 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. */
    unsigned int specified:1;     /* Set if the switch was specified somewhere.
                                     Allows switches that are ON by default to
                                     appear in MAKEFLAGS when set explicitly. */

    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.  */
    enum variable_origin *origin; /* Origin of the value.  */
  };

/* 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.  */

#define TEMP_STDIN_OPT (CHAR_MAX+10)

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

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

    /* These are long-style options.  */
    { CHAR_MAX+1, strlist, &db_flags, 1, 1, 0, 0, "basic", 0, "debug", 0 },
    { CHAR_MAX+2, string, &jobserver_auth, 1, 1, 0, 0, 0, 0, JOBSERVER_AUTH_OPT, 0 },
    { CHAR_MAX+3, flag, &trace_flag, 1, 1, 0, 0, 0, 0, "trace", 0 },
    { CHAR_MAX+4, flag_off, &print_directory_flag, 1, 1, 0, 0, 0,
      &default_print_directory_flag, "no-print-directory", &print_directory_origin },
    { CHAR_MAX+5, flag, &warn_undefined_variables_flag, 1, 1, 0, 0, 0, 0,
      "warn-undefined-variables", 0 },
    { CHAR_MAX+7, string, &sync_mutex, 1, 1, 0, 0, 0, 0, "sync-mutex", 0 },
    { CHAR_MAX+8, flag_off, &silent_flag, 1, 1, 0, 0, 0, &default_silent_flag,
      "no-silent", &silent_origin },
    { CHAR_MAX+9, string, &jobserver_auth, 1, 0, 0, 0, 0, 0, "jobserver-fds", 0 },
    /* There is special-case handling for this in decode_switches() as well.  */
    { TEMP_STDIN_OPT, filename, &makefiles, 0, 0, 0, 0, 0, 0, "temp-stdin", 0 },
    { CHAR_MAX+11, string, &shuffle_mode, 1, 1, 0, 0, "random", 0, "shuffle", 0 },
    { CHAR_MAX+12, string, &jobserver_style, 1, 0, 0, 0, 0, 0, "jobserver-style", 0 },
    { 0, 0, 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 goaldep *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.  */

const char *program;

/* 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 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.  */

#if defined(POSIX)
sigset_t fatal_signal_set;
#elif defined(HAVE_SIGSETMASK)
int fatal_signal_mask;
#endif

#if !HAVE_DECL_BSD_SIGNAL && !defined bsd_signal
# if !defined HAVE_SIGACTION
#  define bsd_signal signal
# else
typedef void (*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 (void)
{
  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_PIPE;
  stopchar_map[(int)'.'] = MAP_DOT | MAP_USERFUNC;
  stopchar_map[(int)','] = MAP_COMMA;
  stopchar_map[(int)'('] = MAP_VARSEP;
  stopchar_map[(int)'{'] = MAP_VARSEP;
  stopchar_map[(int)'}'] = MAP_VARSEP;
  stopchar_map[(int)')'] = MAP_VARSEP;
  stopchar_map[(int)'$'] = MAP_VARIABLE;

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

  stopchar_map[(int)' '] = MAP_BLANK;
  stopchar_map[(int)'\t'] = MAP_BLANK;

  stopchar_map[(int)'/'] = MAP_DIRSEP;
#if MK_OS_VMS
  stopchar_map[(int)':'] |= 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 (isspace (i) && NONE_SET (stopchar_map[i], MAP_BLANK))
        /* Don't mark blank characters as newline characters.  */
        stopchar_map[i] |= MAP_NEWLINE;
      else if (isalnum (i))
        stopchar_map[i] |= MAP_USERFUNC;
    }
}

/* This code is stolen from gnulib.
   If/when we abandon the requirement to work with K&R compilers, we can
   remove this (and perhaps other parts of GNU Make!) and migrate to using
   gnulib directly.

   This is called only through atexit(), which means die() has already been
   invoked.  So, call exit() here directly.  Apparently that works...?
*/

/* Close standard output, exiting with status 'exit_failure' on failure.
   If a program writes *anything* to stdout, that program should close
   stdout and make sure that it succeeds before exiting.  Otherwise,
   suppose that you go to the extreme of checking the return status
   of every function that does an explicit write to stdout.  The last
   printf can succeed in writing to the internal stream buffer, and yet
   the fclose(stdout) could still fail (due e.g., to a disk full error)
   when it tries to write out that buffered data.  Thus, you would be
   left with an incomplete output file and the offending program would
   exit successfully.  Even calling fflush is not always sufficient,
   since some file systems (NFS and CODA) buffer written/flushed data
   until an actual close call.

   Besides, it's wasteful to check the return value from every call
   that writes to stdout -- just let the internal stream state record
   the failure.  That's what the ferror test is checking below.

   It's important to detect such failures and exit nonzero because many
   tools (most notably 'make' and other build-management systems) depend
   on being able to detect failure in other tools via their exit status.  */

static void
close_stdout (void)
{
  int prev_fail = ferror (stdout);
  int fclose_fail = fclose (stdout);

  if (prev_fail || fclose_fail)
    {
      if (fclose_fail)
        perror_with_name (_("write error: stdout"), "");
      else
        O (error, NILF, _("write error: stdout"));
      exit (MAKE_TROUBLE);
    }
}

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 void
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 (trace_flag)
    db_level |= DB_PRINT | DB_WHY;

  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 'p':
                db_level |= DB_PRINT;
                break;
              case 'v':
                db_level |= DB_BASIC | DB_VERBOSE;
                break;
              case 'w':
                db_level |= DB_WHY;
                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)
{
#ifdef NO_OUTPUT_SYNC
  output_sync = OUTPUT_SYNC_NONE;
#else
  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)
    osync_parse_mutex (sync_mutex);
#endif
}

/* Print a nice usage method and exit.  */

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

  if (print_version_flag)
    {
      print_version ();
      fputs ("\n", stdout);
    }

  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"));

  die (bad ? MAKE_FAILURE : MAKE_SUCCESS);
}

#ifdef WINDOWS32

/*
 * 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 W32 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;
  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 && ISDIRSEP (tokend[-1])))
       && !strcasecmp (tokend, "cmd"))
      || ((tokend - 4 == search_token
           || (tokend - 4 > search_token && ISDIRSEP (tokend[-5])))
          && !strcasecmp (tokend - 4, "cmd.exe")))
    {
      batch_mode_shell = 1;
      unixy_shell = 0;
      default_shell = xstrdup (w32ify (search_token, 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 */
      default_shell = xstrdup (w32ify (search_token, 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)
            {
              PATH_VAR (sh_path);

              *ep = '\0';

              snprintf (sh_path, GET_PATH_MAX, "%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)
            {
              PATH_VAR (sh_path);
              snprintf (sh_path, GET_PATH_MAX, "%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__ */

static void
reset_jobserver (void)
{
  jobserver_clear ();
  free (jobserver_auth);
  jobserver_auth = NULL;
}

void
temp_stdin_unlink ()
{
  /* This function is called from a signal handler.  Keep async-signal-safe.
     If there is a temp file from reading from stdin, get rid of it.  */
  if (stdin_offset >= 0)
    {
      const char *nm = makefiles->list[stdin_offset];
      int r = 0;

      stdin_offset = -1;
      EINTRLOOP(r, unlink (nm));
      if (r < 0 && errno != ENOENT && !handling_fatal_signal)
        perror_with_name (_("unlink (temporary file): "), nm);
    }
}

#ifdef MK_OS_ZOS
extern char **environ;
#endif

#if defined(MK_OS_ZOS)
int
main (int argc, char **argv)
#else
int
main (int argc, char **argv, char **envp)
#endif
{
  int makefile_status = MAKE_SUCCESS;
  struct goaldep *read_files;
  PATH_VAR (current_directory);
  unsigned int restarts = 0;
  unsigned int syncing = 0;
  int argv_slots;  /* The jobslot info we got from our parent process.  */
#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

  initialize_variable_output ();

  /* Useful for attaching debuggers, etc.  */
  SPIN ("main-entry");

#ifdef HAVE_ATEXIT
  if (ANY_SET (check_io_state (), IO_STDOUT_OK))
    atexit (close_stdout);
#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
#ifdef SIGPIPE
  FATAL_SIG (SIGPIPE);
#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
    {
#if defined(HAVE_DOS_PATHS)
      const char* start = argv[0];

      /* Skip an initial drive specifier if present.  */
      if (isalpha ((unsigned char)start[0]) && start[1] == ':')
        start += 2;

      if (start[0] == '\0')
        program = "make";
      else
        {
          program = start + strlen (start);
          while (program > start && ! ISDIRSEP (program[-1]))
            --program;

          /* Remove the .exe extension if present.  */
          {
            size_t len = strlen (program);
            if (len > 4 && streq (&program[len - 4], ".exe"))
              program = xstrndup (program, len - 4);
          }
        }
#elif MK_OS_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
      program = strrchr (argv[0], '/');
      if (program == 0)
        program = argv[0];
      else
        ++program;
#endif
    }

  initialize_global_hash_tables ();

  /* Ensure the temp directory is set up: we don't want the first time we use
     it to be in a forked process.  */
  get_tmpdir ();

  /* 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);
  define_variable_cname (".LOADED", "", 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 nocomment"
                           " grouped-target extra-prereqs notintermediate"
                           " shell-export"
#ifndef NO_ARCHIVES
                           " archives"
#endif
#ifdef MAKE_JOBSERVER
                           " jobserver"
# if JOBSERVER_USE_FIFO
                           " jobserver-fifo"
# endif
#endif
#ifndef NO_OUTPUT_SYNC
                           " output-sync"
#endif
#ifdef MAKE_SYMLINKS
                           " check-symlink"
#endif
#ifdef HAVE_GUILE
                           " guile"
#endif
#ifdef MAKE_LOAD
                           " load"
#endif
#ifdef HAVE_DOS_PATHS
                           " dospaths"
#endif
#ifdef MAKE_MAINTAINER_MODE
                           " maintainer"
#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.  */

#ifdef MK_OS_ZOS
  char **envp = environ;
#endif

  {
    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;
        size_t len;

        while (! STOP_SET (*ep, MAP_EQUALS|MAP_NUL))
          ++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 && memcmp (envp[i], "MAKE_RESTARTS", CSTRLEN ("MAKE_RESTARTS")) == 0)
          {
            if (*ep == '-')
              {
                OUTPUT_TRACED ();
                ++ep;
              }
            restarts = make_toui (ep, NULL);
            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

  /* Decode the switches.  */
  if (lookup_variable (STRING_SIZE_TUPLE (GNUMAKEFLAGS_NAME)))
    {
      decode_env_switches (STRING_SIZE_TUPLE (GNUMAKEFLAGS_NAME), o_command);

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

   /* Set MAKEFLAGS's origin to command line: in submakes MAKEFLAGS will carry
      command line switches.  This causes env variable MAKEFLAGS to beat
      makefile modifications to MAKEFLAGS.  */
  decode_env_switches (STRING_SIZE_TUPLE (MAKEFLAGS_NAME), o_command);

#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

  /* 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);

  /* Parse the command line options.  Remember the job slots set this way.  */
  {
    int env_slots = arg_job_slots;
    arg_job_slots = INVALID_JOB_SLOTS;

    decode_switches (argc, (const char **)argv, o_command);
    argv_slots = arg_job_slots;

    if (arg_job_slots == INVALID_JOB_SLOTS)
      arg_job_slots = env_slots;
  }

  if (print_usage_flag)
    print_usage (0);

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

  /* Now that we know we'll be running, force stdout to be line-buffered.  */
#ifdef HAVE_SETVBUF
  setvbuf (stdout, 0, _IOLBF, BUFSIZ);
#elif HAVE_SETLINEBUF
  setlinebuf (stdout);
#endif

  /* Handle shuffle mode argument.  */
  if (shuffle_mode)
    {
      const char *effective_mode;
      shuffle_set_mode (shuffle_mode);

      /* Write fixed seed back to argument list to propagate mode and
         fixed seed to child $(MAKE) runs.  */
      free (shuffle_mode);
      effective_mode = shuffle_get_mode ();
      if (effective_mode)
        shuffle_mode = xstrdup (effective_mode);
      else
        shuffle_mode = NULL;
    }

  /* 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 = make_toui (v->value, NULL);
    else
      makelevel = 0;
  }

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

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

  if (ISDB (DB_BASIC))
    {
      print_version ();

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

#if !MK_OS_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;

  /* 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 && ISDIRSEP (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 */

  /* 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);

  /* Construct the list of include directories to search.
     This will check for existence so it must be done after chdir.  */
  construct_include_path (include_dirs ? include_dirs->list : NULL);

  /* Validate the arg_job_slots configuration before we define MAKEFLAGS so
     users get an accurate value in their makefiles.
     At this point arg_job_slots is the argv setting, if there is one, else
     the MAKEFLAGS env setting, if there is one.  */

  if (jobserver_auth)
    {
      /* We're a child in an existing jobserver group.  */
      if (argv_slots == INVALID_JOB_SLOTS)
        {
          /* There's no -j option on the command line: check authorization.  */
          if (jobserver_parse_auth (jobserver_auth))
            /* Success!  Use the jobserver.  */
            goto job_setup_complete;

          /* Oops: we have jobserver-auth but it's invalid :(.  */
          O (error, NILF, _("warning: jobserver unavailable: using -j1.  Add '+' to parent make rule."));
          arg_job_slots = 1;
        }

      /* The user provided a -j setting on the command line so use it: we're
         the master make of a new jobserver group.  */
      else if (!restarts)
        ON (error, NILF,
            _("warning: -j%d forced in submake: resetting jobserver mode."),
            argv_slots);

      /* We can't use our parent's jobserver, so reset.  */
      reset_jobserver ();
    }

 job_setup_complete:

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

#if MK_OS_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;
      size_t 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", "${-*-command-variables-*-}",
                             o_default, 1);
#if MK_OS_VMS
      vms_export_dcl_symbol ("MAKEOVERRIDES", "${-*-command-variables-*-}");
#endif
    }

  /* 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 *newnm;

            if (stdin_offset >= 0)
              O (fatal, NILF,
                 _("Makefile from standard input specified twice"));

            outfile = get_tmpfile (&newnm);
            if (!outfile)
              O (fatal, NILF,
                 _("cannot store makefile from stdin to a temporary file"));

            while (!feof (stdin) && ! ferror (stdin))
              {
                char buf[2048];
                size_t n = fread (buf, 1, sizeof (buf), stdin);
                if (n > 0 && fwrite (buf, 1, n, outfile) != n)
                  OSS (fatal, NILF,
                       _("fwrite: temporary file %s: %s"), newnm, strerror (errno));
              }
            fclose (outfile);

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

            free (newnm);
          }
    }

  /* Make sure the temporary file is never considered updated.  */
  if (stdin_offset >= 0)
    {
      struct file *f = enter_file (makefiles->list[stdin_offset]);
      f->updated = 1;
      f->update_status = us_success;
      f->command_state = cs_finished;
      /* Can't be intermediate, or it'll be removed before make re-exec.  */
      f->intermediate = 0;
      f->dontcare = 0;
      /* Avoid re-exec due to stdin temp file timestamps.  */
      f->last_mtime = f->mtime_before_update = f_mtime (f, 0);
    }

#ifndef __EMX__ /* Don't use a SIGCHLD handler for OS/2 */
#if !defined(HAVE_WAIT_NOHANG) || defined(MAKE_JOBSERVER)
  /* 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 if
     we're waiting for a token.

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

#if defined(HAVE_PSELECT) && !defined(MK_OS_ZOS)
  /* If we have pselect() then we need to block SIGCHLD so it's deferred.  */
  {
    sigset_t block;
    sigemptyset (&block);
    sigaddset (&block, SIGCHLD);
    if (sigprocmask (SIG_SETMASK, &block, NULL) < 0)
      pfatal_with_name ("sigprocmask(SIG_SETMASK, SIGCHLD)");
  }
#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 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)->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, *endp, *value;
      unsigned int i;
      size_t 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 = endp = value = alloca (len);
      for (i = 0; i < eval_strings->idx; ++i)
        {
          p = stpcpy (p, "--eval=");
          p = quote_for_env (p, eval_strings->list[i]);
          endp = p++;
          *endp = ' ';
        }
      *endp = '\0';

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

  {
    int old_builtin_rules_flag = no_builtin_rules_flag;
    int old_builtin_variables_flag = no_builtin_variables_flag;
    int old_arg_job_slots = arg_job_slots;

    /* Read all the makefiles.  */
    read_files = read_all_makefiles (makefiles == 0 ? 0 : makefiles->list);

    arg_job_slots = INVALID_JOB_SLOTS;

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

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

    decode_env_switches (STRING_SIZE_TUPLE (MAKEFLAGS_NAME), o_env);
#if 0
    decode_env_switches (STRING_SIZE_TUPLE ("MFLAGS"));
#endif

    /* If -j is not set in the makefile, or it was set on the command line,
       reset to use the previous value.  */
    if (arg_job_slots == INVALID_JOB_SLOTS || argv_slots != INVALID_JOB_SLOTS)
      arg_job_slots = old_arg_job_slots;

    else if (jobserver_auth && arg_job_slots != old_arg_job_slots)
      {
        /* Makefile MAKEFLAGS set -j, but we already have a jobserver.
           Make us the master of a new jobserver group.  */
        if (!restarts)
          ON (error, NILF,
              _("warning: -j%d forced in makefile: resetting jobserver mode."),
              arg_job_slots);

        /* We can't use our parent's jobserver, so reset.  */
        reset_jobserver ();
      }

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

    /* 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 ();
  }

#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__) || MK_OS_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__ */

  /* Final jobserver configuration.

     If we have jobserver_auth then we are a client in an existing jobserver
     group, that's already been verified OK above.  If we don't have
     jobserver_auth and jobserver is enabled, then start a new jobserver.

     arg_job_slots = INVALID_JOB_SLOTS if we don't want -j in MAKEFLAGS

     arg_job_slots = # of jobs of parallelism

     job_slots = 0 for no limits on jobs, or when limiting via jobserver.

     job_slots = 1 for standard non-parallel mode.

     job_slots >1 for old-style parallelism without jobservers.  */

  if (jobserver_auth)
    job_slots = 0;
  else if (arg_job_slots == INVALID_JOB_SLOTS)
    job_slots = 1;
  else
    job_slots = arg_job_slots;

#if defined (__MSDOS__) || defined (__EMX__) || MK_OS_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."));
      arg_job_slots = INVALID_JOB_SLOTS;
      job_slots = 1;
    }
#endif

  /* If we have >1 slot at this point, then we're a top-level make.
     Set up the jobserver.

     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.  */

  if (job_slots > 1 && jobserver_setup (job_slots - 1, jobserver_style))
    {
      /* Fill in the jobserver_auth for our children.  */
      jobserver_auth = jobserver_get_auth ();

      if (jobserver_auth)
        {
          /* We're using the jobserver so set job_slots to 0.  */
          master_job_slots = job_slots;
          job_slots = 0;
        }
    }

  /* If we're not using parallel jobs, then we don't need output sync.
     This is so people can enable output sync in GNUMAKEFLAGS or similar, but
     not have it take effect unless parallel builds are enabled.  */
  if (syncing && job_slots == 1)
    {
      OUTPUT_UNSET ();
      output_close (&make_sync);
      syncing = 0;
      output_sync = OUTPUT_SYNC_NONE;
    }

  if (syncing)
    {
      /* If there is no mutex we're the base: create one.  Else parse it.  */
      if (!sync_mutex)
        {
          osync_setup ();
          sync_mutex = osync_get_mutex ();
        }
      else if (!osync_parse_mutex (sync_mutex))
        {
          /* Parsing failed; continue without output sync.  */
          osync_clear ();
          free (sync_mutex);
          sync_mutex = NULL;
          syncing = 0;
        }
    }

  if (jobserver_auth)
    DB (DB_VERBOSE|DB_JOBS, (_("Using jobserver controller %s\n"), jobserver_auth));
  if (sync_mutex)
    DB (DB_VERBOSE, (_("Using output-sync mutex %s\n"), sync_mutex));

#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 (0);

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

  snap_deps ();

  /* Define the file rules for the built-in suffix rules.  These will later
     be converted into pattern rules.  */

  install_default_suffix_rules ();

  /* 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 and do magic for pattern rules.  */

  snap_implicit_rules ();

  /* 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 (shuffle_mode)
    DB (DB_BASIC, (_("Enabled shuffle mode: %s\n"), shuffle_mode));

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

      FILE_TIMESTAMP *makefile_mtimes;
      struct goaldep *skipped_makefiles = NULL;
      const char **nargv = (const char **) argv;
      int any_failed = 0;
      enum update_status status;

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

      /* Count the makefiles, and reverse the order so that we attempt to
         rebuild them in the order they were read.  */
      {
        unsigned int num_mkfiles = 0;
        struct goaldep *d = read_files;
        read_files = NULL;
        while (d != NULL)
          {
            struct goaldep *t = d;
            d = d->next;
            t->next = read_files;
            read_files = t;
            ++num_mkfiles;
          }

        makefile_mtimes = alloca (num_mkfiles * sizeof (FILE_TIMESTAMP));
      }

      /* Remove any makefiles we don't want to try to update.  Record the
         current modtimes of the others so we can compare them later.  */
      {
        struct goaldep *d = read_files;
        struct goaldep *last = NULL;
        unsigned int mm_idx = 0;

        while (d != 0)
          {
            int skip = 0;
            struct file *f = d->file;

            /* Check for makefiles that are either phony or a :: target with
               commands, but no dependencies.  These will always be remade,
               which will cause an infinite restart 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.)  */

            if (f->phony)
              skip = 1;
            else
              for (f = f->double_colon; f != NULL; f = f->prev)
                if (f->deps == NULL && f->cmds != NULL)
                  {
                    skip = 1;
                    break;
                  }

            if (!skip)
              {
                makefile_mtimes[mm_idx++] = file_mtime_no_search (d->file);
                last = d;
                d = d->next;
              }
            else
              {
                DB (DB_VERBOSE,
                    (_("Makefile '%s' might loop; not remaking it.\n"),
                     f->name));

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

                if (d->error && ! (d->flags & RM_DONTCARE))
                  {
                    /* This file won't be rebuilt, was not found, and we care,
                       so remember it to report later.  */
                    d->next = skipped_makefiles;
                    skipped_makefiles = d;
                    any_failed = 1;
                  }
                else
                  free_goaldep (d);

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

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

      {
        int orig_db_level = db_level;

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

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

        db_level = orig_db_level;
      }

      /* Report errors for makefiles that needed to be remade but were not.  */
      while (skipped_makefiles != NULL)
        {
          struct goaldep *d = skipped_makefiles;
          const char *err = strerror (d->error);

          OSS (error, &d->floc, _("%s: %s"), dep_name (d), err);

          skipped_makefiles = skipped_makefiles->next;
          free_goaldep (d);
        }

      /* If we couldn't build something we need but otherwise we succeeded,
         reset the status.  */
      if (any_failed && status == us_success)
        status = us_none;

      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".  */
          break;

        case us_none:
          {
             /* Reload any unloaded shared objects.  Do not re-exec to have
                that shared object loaded: a re-exec would cause an infinite
                loop, because the shared object was not updated.  */
            struct goaldep *d;

            for (d = read_files; d; d = d->next)
              if (d->file->unloaded)
                {
                  struct file *f = d->file;
                  /* Load the file.  0 means failure.  */
                  if (load_file (&d->floc, f, 0) == 0)
                    OS (fatal, &d->floc, _("%s: failed to load"), f->name);
                  f->unloaded = 0;
                  f->loaded = 1;
                }
          }

          /* No makefiles needed to be updated.  If we couldn't read some
             included file that we care about, fail.  */
          if (0)
            {
              /* This runs afoul of https://savannah.gnu.org/bugs/?61226
                 The problem is that many makefiles use a "dummy rule" to
                 pretend that an included file is rebuilt, without actually
                 rebuilding it, and this has always worked.  There are a
                 number of solutions proposed in that bug but for now we'll
                 put things back so they work the way they did before.  */
              struct goaldep *d;

              for (d = read_files; d != 0; d = d->next)
                if (d->error && ! (d->flags & RM_DONTCARE))
                  {
                    /* This makefile couldn't be loaded, and we care.  */
                    const char *err = strerror (d->error);
                    OSS (error, &d->floc, _("%s: %s"), dep_name (d), err);
                    any_failed = 1;
                  }
            }
          break;

        case us_failed:
          /* Failed to update.  Figure out if we care.  */
          {
            /* Nonzero if any makefile was successfully remade.  */
            int any_remade = 0;
            unsigned int i;
            struct goaldep *d;

            for (i = 0, d = read_files; d != 0; ++i, d = d->next)
              {
                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->flags & RM_DONTCARE))
                      {
                        FILE_TIMESTAMP mtime;
                        /* The update failed and this makefile was not
                           from the MAKEFILES variable, so we care.  */
                        OS (error, &d->floc,
                            _("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;
                        any_failed = 1;
                      }
                  }

                /* This makefile was not found at all.  */
                else if (! (d->flags & RM_DONTCARE))
                  {
                    const char *dnm = dep_name (d);

                    /* This is a makefile we care about.  See how much.  */
                    if (d->flags & RM_INCLUDED)
                      /* An included makefile.  We don't need to die, but we
                         do want to complain.  */
                      OS (error, &d->floc,
                          _("Included makefile '%s' was not found."), dnm);
                    else
                      {
                        /* A normal makefile.  We must die later.  */
                        OS (error, NILF, _("Makefile '%s' was not found"), dnm);
                        any_failed = 1;
                      }
                  }
              }

            if (any_remade)
              goto re_exec;

            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)
            {
              /* Makefile names might have changed due to expansion.
                 It's possible we'll need one extra argument:
                   make -Rf-
                 will expand to:
                   make -R --temp-stdin=<tmpfile>
                 so allocate more space.
              */
              int mfidx = 0;
              char** av = argv;
              const char** nv;

              nv = nargv = alloca (sizeof (char*) * (argc + 1 + 1));
              *(nv++) = *(av++);

              for (; *av; ++av, ++nv)
                {
                  char *f;
                  char *a = *av;
                  const char *mf = makefiles->list[mfidx];

                  assert (strlen (a) > 0);

                  *nv = a;

                  /* Not an option: we handled option args earlier.  */
                  if (a[0] != '-')
                    continue;

                  /* See if this option specifies a filename.  If so we need
                     to replace it with the value from makefiles->list.

                     To simplify, we'll replace all possible versions of this
                     flag with a simple "-f<name>".  */

                  /* Handle long options.  */
                  if (a[1] == '-')
                    {
                      if (strcmp (a, "--file") == 0 || strcmp (a, "--makefile") == 0)
                        /* Skip the next arg as we'll combine them.  */
                        ++av;
                      else if (!strneq (a, "--file=", 7)
                               && !strneq (a, "--makefile=", 11))
                        continue;

                      if (mfidx == stdin_offset)
                        {
                          char *na = alloca (CSTRLEN ("--temp-stdin=")
                                             + strlen (mf) +  1);
                          sprintf (na, "--temp-stdin=%s", mf);
                          *nv = na;
                        }
                      else
                        {
                          char *na = alloca (strlen (mf) + 3);
                          sprintf (na, "-f%s", mf);
                          *nv = na;
                        }

                      ++mfidx;
                      continue;
                    }

                  /* Handle short options.  If 'f' is the last option, it may
                     be followed by <name>.  */
                  f = strchr (a, 'f');
                  if (!f)
                    continue;

                  /* If there's an extra argument option skip it.  */
                  if (f[1] == '\0')
                    ++av;

                  if (mfidx == stdin_offset)
                    {
                      const size_t al = f - a;
                      char *na;

                      if (al > 1)
                        {
                          /* Preserve the prior options.  */
                          na = alloca (al + 1);
                          memcpy (na, a, al);
                          na[al] = '\0';
                          *(nv++) = na;
                        }

                      /* Remove the "f" and any subsequent content.  */
                      na = alloca (CSTRLEN ("--temp-stdin=") + strlen (mf) + 1);
                      sprintf (na, "--temp-stdin=%s", mf);
                      *nv = na;
                    }
                  else if (f[1] == '\0')
                    /* -f <name> or -xyzf <name>.  Replace the name.  */
                    *(++nv) = mf;
                  else
                    {
                      /* -f<name> or -xyzf<name>. */
                      const size_t al = f - a + 1;
                      const size_t ml = strlen (mf) + 1;
                      char *na = alloca (al + ml);
                      memcpy (na, a, al);
                      memcpy (na + al, mf, ml);
                      *nv = na;
                    }

                  ++mfidx;
                }

              *nv = NULL;
            }

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

          {
            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);
#if MK_OS_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;
                  }
              }
          }

          /* 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);

          osync_clear();

          /* The exec'd "child" will be another make, of course.  */
          jobserver_pre_child(1);

#if 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. */
            pid_t pid;
            int r;
            struct childbase child;
            child.cmd_name = NULL;
            child.output.syncout = 0;
            child.environment = environ;

            pid = child_execute_job (&child, 1, (char **)nargv);

            /* 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
#ifdef SET_STACK_SIZE
          /* Reset limits, if necessary.  */
          if (stack_limit.rlim_cur)
            setrlimit (RLIMIT_STACK, &stack_limit);
#endif
          exec_command ((char **)nargv, environ);
#endif
          jobserver_post_child(1);

          temp_stdin_unlink ();

          _exit (127);
        }

      if (any_failed)
        die (MAKE_FAILURE);
    }

  /* Set up 'MAKEFLAGS' again for the normal targets.  */
  define_makeflags (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;
        }
    }

  temp_stdin_unlink ();

  /* 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_goaldep ();
              goals->file = f;
            }
        }
    }
  else
    lastgoal->next = 0;


  if (!goals)
    {
      struct variable *v = lookup_variable (STRING_SIZE_TUPLE ("MAKEFILE_LIST"));
      if (v && v->value && v->value[0] != '\0')
        O (fatal, NILF, _("No targets"));

      O (fatal, NILF, _("No targets specified and no makefile found"));
    }

  /* Shuffle prerequisites to catch makefiles with incomplete depends. */

  shuffle_goaldeps_recursive (goals);

  /* 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 = (char *) (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++ = (char) 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, enum variable_origin origin)
{
  struct variable *v;

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

#if MK_OS_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, origin, 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 (arg[0] != '\0' && origin == o_command)
    {
      /* 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.
         Check ARG[0] because if the top makefile resets MAKEOVERRIDES
         then ARG points to an empty string in the submake.  */
      struct file *f = enter_file (strcache_add (expand_command_line_file (arg)));
      f->cmd_target = 1;

      if (goals == 0)
        {
          goals = alloc_goaldep ();
          lastgoal = goals;
        }
      else
        {
          lastgoal->next = alloc_goaldep ();
          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 */
            size_t 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);
      }
    }
}

/* Called if the makefile resets the MAKEFLAGS variable.  */
void
reset_makeflags (enum variable_origin origin)
{
  decode_env_switches (STRING_SIZE_TUPLE(MAKEFLAGS_NAME), origin);
  construct_include_path (include_dirs ? include_dirs->list : NULL);
  define_makeflags (rebuilding_makefiles);
}

/* Decode switches from ARGC and ARGV.
   They came from the environment if ORIGIN is o_env.  */

static void
decode_switches (int argc, const char **argv, enum variable_origin origin)
{
  int bad = 0;
  struct command_switch *cs;
  struct stringlist *sl;
  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 = origin == o_command;
  /* 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, origin);
      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 = (origin == o_command
                          || (cs->env &&
                              (cs->origin == NULL || origin >= *cs->origin)));

              if (doit)
                cs->specified = 1;

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

                case ignore:
                  break;

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

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

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

                      if (short_option (cs->c))
                        opt[0] = (char) 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);
                      if (cs->origin)
                        *cs->origin = origin;
                      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 *));
                    }

                  /* Filter out duplicate options.
                   * Allow duplicate makefiles for backward compatibility.  */
                  if (cs->c != 'f')
                    {
                      unsigned int k;
                      for (k = 0; k < sl->idx; ++k)
                        if (streq (sl->list[k], coptarg))
                          break;
                      if (k < sl->idx)
                        break;
                    }

                  if (cs->type == strlist)
                    {
                      sl->list[sl->idx++] = xstrdup (coptarg);
                      if (cs->origin)
                        *cs->origin = origin;
                    }
                  else if (cs->c == TEMP_STDIN_OPT)
                    {
                      if (stdin_offset > 0)
                        fatal (NILF, 0, "INTERNAL: multiple --temp-stdin options provided!");
                      /* We don't need to expand the temp file.  */
                      stdin_offset = sl->idx;
                      sl->list[sl->idx++] = strcache_add (coptarg);
                      if (cs->origin)
                        *cs->origin = origin;
                    }
                  else
                    {
                      sl->list[sl->idx++] = expand_command_line_file (coptarg);
                      if (cs->origin)
                        *cs->origin = origin;
                    }
                  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)
                    {
                      const char *err;
                      unsigned int i = make_toui (coptarg, &err);

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

                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);
                      if (cs->origin)
                        *cs->origin = origin;
                    }

                  break;
                }

              /* 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++], origin);

  if (bad && origin == o_command)
    print_usage (bad);

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

  /* Perform any special switch handling.  */
  run_silent = silent_flag;
}

/* 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, size_t len, enum variable_origin origin)
{
  char *varref = alloca (2 + len + 2);
  char *value, *p, *buf;
  int argc;
  const char **argv;

  /* Get the variable's value.  */
  p = varref;
  *(p++) = '$';
  *(p++) = '(';
  p = mempcpy (p, envar, len);
  *(p++) = ')';
  *p = '\0';
  value = variable_expand (varref);

  /* Skip whitespace, and check for an empty 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] = "";
  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 (*value))
        {
          /* End of the word.  */
          *p++ = '\0';
          argv[++argc] = p;
          do
            ++value;
          while (ISBLANK (*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, origin);
}

/* 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 (*in) || *in == '\\')
        *out++ = '\\';
      *out++ = *in++;
    }

  return out;
}

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

struct variable *
define_makeflags (int makefile)
{
  const char ref[] = "MAKEOVERRIDES";
  const char posixref[] = "-*-command-variables-*-";
  const char evalref[] = "$(-*-eval-flags-*-)";
  const struct command_switch *cs;
  struct variable *v;
  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;
  size_t 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 == NULL || cs->specified
                  || *(int *) cs->value_ptr != *(int *) cs->default_value))
            ADD_FLAG (0, 0);
          break;

        case positive_int:
          if ((cs->default_value != 0
               && (*(unsigned int *) cs->value_ptr
                   == *(unsigned int *) cs->default_value)))
            break;
          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;

        case floating:
          if (cs->default_value != 0
              && (*(double *) cs->value_ptr == *(double *) cs->default_value))
            break;
          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;

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

        case filename:
        case strlist:
          {
            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) + 4 + CSTRLEN (evalref) + 4;

  /* 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++ = (char) 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++ = (char) flags->cs->c;
      else
        {
          /* Long options require a double-dash.  */
          *p++ = '-';
          p = stpcpy (p, flags->cs->long_name);
        }
      /* 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++ = ' ';
      p = mempcpy (p, evalref, CSTRLEN (evalref));
    }

  {
    /* If there are any overrides to add, write a reference to
       $(MAKEOVERRIDES), which contains command-line variable definitions.
       Separate the variables from the switches with a "--" arg.  */

    const char *r = posix_pedantic ? posixref : ref;
    size_t l = strlen (r);
    v = lookup_variable (r, l);

    if (v && v->value && v->value[0] != '\0')
      {
        p = stpcpy (p, " -- ");
        *(p++) = '$';
        *(p++) = '(';
        p = mempcpy (p, r, l);
        *(p++) = ')';
      }
  }

  /* 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.  */
  v =  define_variable_cname (MAKEFLAGS_NAME, flagstring,
                              env_overrides ? o_env_override : o_file, 1);
  v->special = 1;

  return v;
}

/* Return 1 if the working directory change message should be printed.
   Otherwise, return 0.  */
int
should_print_dir (void)
{
    if (print_directory_flag >= 0)
        return print_directory_flag;

    /* If the user didn't specify any print-directory options, compute the
       default setting: disable under -s / print in sub-makes and under -C.  */
    return !silent_flag && (makelevel > 0 || directories != NULL);
}

/* 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) 1988-2023 Free Software Foundation, Inc.\n",
          precede);

  printf (_("%sLicense GPLv3+: GNU GPL version 3 or later <https://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;
}

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

static void
print_data_base (void)
{
  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.  */

  if (jobserver_enabled() && jobserver_tokens)
    {
      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)
          jobserver_release (0);
    }


  /* 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 tokens = 1 + jobserver_acquire_all ();

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

      reset_jobserver ();
    }
}

/* 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 ();

      /* Get rid of a temp file from reading a makefile from stdin.  */
      temp_stdin_unlink ();

      /* 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);

      osync_clear ();

      /* 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);
}