src/main.c

   1 /* GNU m4 -- A simple macro processor
   2
   3    Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 1999, 2000, 2003,
   4    2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6    This file is part of GNU M4.
   7
   8    GNU M4 is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    GNU M4 is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include <config.h>
  23
  24 #include <locale.h>
  25
  26 #include "m4.h"
  27
  28 #include "close-stream.h"
  29 #include "closein.h"
  30 #include "configmake.h"
  31 #include "getopt.h"
  32 #include "propername.h"
  33 #include "quotearg.h"
  34 #include "version-etc.h"
  35 #include "xstrtol.h"
  36
  37 #define AUTHORS                                                 \
  38   proper_name_utf8 ("Rene' Seindal", "Ren\xc3\xa9 Seindal"),    \
  39   proper_name ("Gary V. Vaughan"),                              \
  40   proper_name ("Eric Blake")
  41
  42 typedef struct deferred
  43 {
  44   struct deferred *next;
  45   int code;                     /* deferred optchar */
  46   const char *value;
  47 } deferred;
  48
  49 \f
  50 /* Error handling functions.  */
  51
  52 #ifdef USE_STACKOVF
  53
  54 /* Tell user stack overflowed and abort.  */
  55 static void
  56 stackovf_handler (void)
  57 {
  58   /* FIXME - calling gettext and error inside a signal handler is dangerous,
  59      since these functions invoke functions that are not signal-safe.  We
  60      are sort of justified by the fact that we will exit and never return,
  61      but this should really be fixed.  */
  62   error (EXIT_FAILURE, 0, _("stack overflow (infinite define recursion?)"));
  63 }
  64
  65 #endif /* USE_STACKOVF */
  66
  67
  68 \f
  69 /* Print a usage message and exit with STATUS.  */
  70 static void
  71 usage (int status)
  72 {
  73   if (status != EXIT_SUCCESS)
  74     xfprintf (stderr, _("Try `%s --help' for more information.\n"),
  75               m4_get_program_name ());
  76   else
  77     {
  78       xprintf (_("Usage: %s [OPTION]... [FILE]...\n"), m4_get_program_name ());
  79       fputs (_("\
  80 Process macros in FILEs.\n\
  81 If no FILE or if FILE is `-', standard input is read.  If no FILE, and both\n\
  82 standard input and standard error are terminals, -i is implied.\n\
  83 "), stdout);
  84       puts ("");
  85       fputs (_("\
  86 Mandatory or optional arguments to long options are mandatory or optional\n\
  87 for short options too.\n\
  88 \n\
  89 Operation modes:\n\
  90       --help                   display this help and exit\n\
  91       --version                output version information and exit\n\
  92 "), stdout);
  93       fputs (_("\
  94   -b, --batch                  buffer output, process interrupts\n\
  95   -c, --discard-comments       do not copy comments to the output\n\
  96   -E, --fatal-warnings         once: warnings become errors, twice: stop\n\
  97                                execution at first error\n\
  98   -i, --interactive            unbuffer output, ignore interrupts\n\
  99   -P, --prefix-builtins        force a `m4_' prefix to all builtins\n\
 100   -Q, --quiet, --silent        suppress some warnings for builtins\n\
 101   -r, --regexp-syntax[=SPEC]   set default regexp syntax to SPEC [GNU_M4]\n\
 102       --safer                  disable potentially unsafe builtins\n\
 103   -W, --warnings               enable all warnings\n\
 104 "), stdout);
 105       puts ("");
 106       fputs (_("\
 107 SPEC is any one of:\n\
 108   AWK, BASIC, BSD_M4, ED, EMACS, EXTENDED, GNU_AWK, GNU_EGREP, GNU_M4,\n\
 109   GREP, POSIX_AWK, POSIX_EGREP, MINIMAL, MINIMAL_BASIC, SED.\n\
 110 "), stdout);
 111       puts ("");
 112       xprintf (_("\
 113 Dynamic loading features:\n\
 114   -M, --module-directory=DIR   add DIR to module search path before\n\
 115                                `%s'\n\
 116   -m, --load-module=MODULE     load dynamic MODULE\n\
 117       --unload-module=MODULE   unload dynamic MODULE\n\
 118 "), PKGLIBEXECDIR);
 119       puts ("");
 120       fputs (_("\
 121 Preprocessor features:\n\
 122   -B, --prepend-include=DIR    add DIR to include path before `.'\n\
 123   -D, --define=NAME[=VALUE]    define NAME as having VALUE, or empty\n\
 124       --import-environment     import all environment variables as macros\n\
 125   -I, --include=DIR            add DIR to include path after `.'\n\
 126 "), stdout);
 127       fputs (_("\
 128       --popdef=NAME            popdef NAME\n\
 129   -p, --pushdef=NAME[=VALUE]   pushdef NAME as having VALUE, or empty\n\
 130   -s, --synclines              short for --syncoutput=1\n\
 131       --syncoutput[=STATE]     set generation of `#line NUM \"FILE\"' lines\n\
 132                                to STATE (0=off, 1=on, default 0 if omitted)\n\
 133   -U, --undefine=NAME          undefine NAME\n\
 134 "), stdout);
 135       puts ("");
 136       fputs (_("\
 137 Limits control:\n\
 138   -g, --gnu                    override -G to re-enable GNU extensions\n\
 139   -G, --traditional, --posix   suppress all GNU extensions\n\
 140   -L, --nesting-limit=NUMBER   change artificial nesting limit [1024]\n\
 141 "), stdout);
 142       puts ("");
 143       fputs (_("\
 144 Frozen state files:\n\
 145   -F, --freeze-state=FILE      produce a frozen state on FILE at end\n\
 146   -R, --reload-state=FILE      reload a frozen state from FILE at start\n\
 147 "), stdout);
 148       puts ("");
 149       fputs (_("\
 150 Debugging:\n\
 151   -d, --debug[=[-|+]FLAGS], --debugmode[=[-|+]FLAGS]\n\
 152                                set debug level (no FLAGS implies `+adeq')\n\
 153       --debugfile=FILE         redirect debug and trace output\n\
 154   -l, --debuglen=NUM           restrict macro tracing size\n\
 155   -t, --trace=NAME, --traceon=NAME\n\
 156                                trace NAME when it is defined\n\
 157       --traceoff=NAME          no longer trace NAME\n\
 158 "), stdout);
 159       puts ("");
 160       fputs (_("\
 161 FLAGS is any of:\n\
 162   a   show actual arguments in trace\n\
 163   c   show collection line in trace\n\
 164   d   warn when dereferencing undefined macros (default on unless -E)\n\
 165   e   show expansion in trace\n\
 166   f   include current input file name in trace and debug\n\
 167   i   show changes in input files in debug\n\
 168   l   include current input line number in trace and debug\n\
 169 "), stdout);
 170       fputs (_("\
 171   m   show module information in trace, debug, and dumpdef\n\
 172   p   show results of path searches in debug\n\
 173   q   quote values in dumpdef and trace, useful with a or e\n\
 174   s   show full stack of pushdef values in dumpdef\n\
 175   t   trace all macro calls, regardless of per-macro traceon state\n\
 176   x   include unique macro call id in trace, useful with c\n\
 177   V   shorthand for all of the above flags\n\
 178 "), stdout);
 179       puts ("");
 180       fputs (_("\
 181 If defined, the environment variable `M4PATH' is a colon-separated list\n\
 182 of directories included after any specified by `-I', and the variable\n\
 183 `M4MODPATH' is a colon-separated list of directories searched before any\n\
 184 specified by `-M'.  The environment variable `POSIXLY_CORRECT' implies\n\
 185 -G -Q; otherwise GNU extensions are enabled by default.\n\
 186 "), stdout);
 187       puts ("");
 188       fputs (_("\
 189 Exit status is 0 for success, 1 for failure, 63 for frozen file version\n\
 190 mismatch, or whatever value was passed to the m4exit macro.\n\
 191 "), stdout);
 192       puts ("");
 193       /* TRANSLATORS: the placeholder indicates the bug-reporting
 194          address for this application.  Please add _another line_
 195          saying "Report translation bugs to <...>\n" with the address
 196          for translation bugs (typically your translation team's web
 197          or email address).  */
 198       xprintf (_("Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 199     }
 200   exit (status);
 201 }
 202
 203 /* For long options that have no equivalent short option, use a
 204    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
 205 enum
 206 {
 207   ARGLENGTH_OPTION = CHAR_MAX + 1,      /* not quite -l, because of message */
 208   DEBUGFILE_OPTION,                     /* no short opt */
 209   ERROR_OUTPUT_OPTION,                  /* not quite -o, because of message */
 210   HASHSIZE_OPTION,                      /* not quite -H, because of message */
 211   IMPORT_ENVIRONMENT_OPTION,            /* no short opt */
 212   POPDEF_OPTION,                        /* no short opt */
 213   PREPEND_INCLUDE_OPTION,               /* not quite -B, because of message */
 214   SAFER_OPTION,                         /* -S still has old no-op semantics */
 215   SYNCOUTPUT_OPTION,                    /* not quite -s, because of opt arg */
 216   TRACEOFF_OPTION,                      /* no short opt */
 217   UNLOAD_MODULE_OPTION,                 /* no short opt */
 218   WORD_REGEXP_OPTION,                   /* deprecated, used to be -W */
 219
 220   HELP_OPTION,                          /* no short opt */
 221   VERSION_OPTION                        /* no short opt */
 222 };
 223
 224 /* Decode options and launch execution.  */
 225 static const struct option long_options[] =
 226 {
 227   {"batch", no_argument, NULL, 'b'},
 228   {"debug", optional_argument, NULL, 'd'},
 229   {"debuglen", required_argument, NULL, 'l'},
 230   {"debugmode", optional_argument, NULL, 'd'},
 231   {"define", required_argument, NULL, 'D'},
 232   {"discard-comments", no_argument, NULL, 'c'},
 233   {"fatal-warnings", no_argument, NULL, 'E'},
 234   {"freeze-state", required_argument, NULL, 'F'},
 235   {"gnu", no_argument, NULL, 'g'},
 236   {"include", required_argument, NULL, 'I'},
 237   {"interactive", no_argument, NULL, 'i'},
 238   {"load-module", required_argument, NULL, 'm'},
 239   {"module-directory", required_argument, NULL, 'M'},
 240   {"nesting-limit", required_argument, NULL, 'L'},
 241   {"posix", no_argument, NULL, 'G'},
 242   {"prefix-builtins", no_argument, NULL, 'P'},
 243   {"pushdef", required_argument, NULL, 'p'},
 244   {"quiet", no_argument, NULL, 'Q'},
 245   {"regexp-syntax", optional_argument, NULL, 'r'},
 246   {"reload-state", required_argument, NULL, 'R'},
 247   {"silent", no_argument, NULL, 'Q'},
 248   {"synclines", no_argument, NULL, 's'},
 249   {"trace", required_argument, NULL, 't'},
 250   {"traceon", required_argument, NULL, 't'},
 251   {"traditional", no_argument, NULL, 'G'},
 252   {"undefine", required_argument, NULL, 'U'},
 253   {"warnings", no_argument, NULL, 'W'},
 254
 255   {"arglength", required_argument, NULL, ARGLENGTH_OPTION},
 256   {"debugfile", required_argument, NULL, DEBUGFILE_OPTION},
 257   {"hashsize", required_argument, NULL, HASHSIZE_OPTION},
 258   {"error-output", required_argument, NULL, ERROR_OUTPUT_OPTION},
 259   {"import-environment", no_argument, NULL, IMPORT_ENVIRONMENT_OPTION},
 260   {"popdef", required_argument, NULL, POPDEF_OPTION},
 261   {"prepend-include", required_argument, NULL, PREPEND_INCLUDE_OPTION},
 262   {"safer", no_argument, NULL, SAFER_OPTION},
 263   {"syncoutput", optional_argument, NULL, SYNCOUTPUT_OPTION},
 264   {"traceoff", required_argument, NULL, TRACEOFF_OPTION},
 265   {"unload-module", required_argument, NULL, UNLOAD_MODULE_OPTION},
 266   {"word-regexp", required_argument, NULL, WORD_REGEXP_OPTION},
 267
 268   {"help", no_argument, NULL, HELP_OPTION},
 269   {"version", no_argument, NULL, VERSION_OPTION},
 270
 271   { NULL, 0, NULL, 0 },
 272 };
 273
 274 /* POSIX requires only -D, -U, and -s; and says that the first two
 275    must be recognized when interspersed with file names.  Traditional
 276    behavior also handles -s between files.  Starting OPTSTRING with
 277    '-' forces getopt_long to hand back file names as arguments to opt
 278    '\1', rather than reordering the command line.  */
 279 #define OPTSTRING "-B:D:EF:GH:I:L:M:PQR:S:T:U:Wbcd::egil:m:o:p:r::st:"
 280
 281 /* For determining whether to be interactive.  */
 282 enum interactive_choice
 283 {
 284   INTERACTIVE_UNKNOWN,  /* Still processing arguments, no -b or -i yet */
 285   INTERACTIVE_YES,      /* -i specified last */
 286   INTERACTIVE_NO        /* -b specified last */
 287 };
 288
 289 /* Convert OPT to size_t, reporting an error using long option index
 290    OI or short option character OPTCHAR if it does not fit.  */
 291 static size_t
 292 size_opt (char const *opt, int oi, int optchar)
 293 {
 294   unsigned long int size;
 295   strtol_error status = xstrtoul (opt, NULL, 10, &size, "kKmMgGtTPEZY0");
 296   if (SIZE_MAX < size && status == LONGINT_OK)
 297     status = LONGINT_OVERFLOW;
 298   if (status != LONGINT_OK)
 299     xstrtol_fatal (status, oi, optchar, long_options, opt);
 300   return size;
 301 }
 302
 303 /* Process a command line file NAME, and return true only if it was
 304    stdin.  */
 305 static void
 306 process_file (m4 *context, const char *name)
 307 {
 308   if (strcmp (name, "-") == 0)
 309     m4_push_file (context, stdin, "stdin", false);
 310   else
 311     {
 312       char *full_name;
 313       FILE *fp = m4_path_search (context, name, &full_name);
 314       if (fp == NULL)
 315         {
 316           m4_error (context, 0, errno, NULL, _("cannot open file `%s'"), name);
 317           return;
 318         }
 319       m4_push_file (context, fp, full_name, true);
 320       free (full_name);
 321     }
 322   m4_macro_expand_input (context);
 323 }
 324
 325
 326 /* Main entry point.  Parse arguments, load modules, then parse input.  */
 327 int
 328 main (int argc, char *const *argv, char *const *envp)
 329 {
 330   deferred *head = NULL;        /* head of deferred argument list */
 331   deferred *tail = NULL;
 332   deferred *defn;
 333   size_t size;                  /* for parsing numeric option arguments */
 334
 335   bool import_environment = false; /* true to import environment */
 336   bool seen_file = false;
 337   const char *debugfile = NULL;
 338   const char *frozen_file_to_read = NULL;
 339   const char *frozen_file_to_write = NULL;
 340   enum interactive_choice interactive = INTERACTIVE_UNKNOWN;
 341
 342   m4 *context;
 343
 344   int exit_status;
 345
 346   /* Initialize gnulib error module.  */
 347   m4_set_program_name (argv[0]);
 348   atexit (close_stdin);
 349
 350   setlocale (LC_ALL, "");
 351 #ifdef ENABLE_NLS
 352   textdomain (PACKAGE);
 353 #endif
 354
 355   LTDL_SET_PRELOADED_SYMBOLS ();
 356
 357   context = m4_create ();
 358
 359   m4__module_init (context);
 360
 361 #ifdef USE_STACKOVF
 362   setup_stackovf_trap (argv, envp, stackovf_handler);
 363 #endif
 364
 365   if (getenv ("POSIXLY_CORRECT"))
 366     {
 367       m4_set_posixly_correct_opt (context, true);
 368       m4_set_suppress_warnings_opt (context, true);
 369     }
 370   set_quoting_style (NULL, escape_quoting_style);
 371   set_char_quoting (NULL, ':', 1);
 372
 373   /* First, we decode the arguments, to size up tables and stuff.
 374      Avoid lasting side effects; for example 'm4 --debugfile=oops
 375      --help' must not create the file `oops'.  */
 376   while (1)
 377     {
 378       int oi = -1;
 379       int optchar = getopt_long (argc, (char **) argv, OPTSTRING,
 380                                  long_options, &oi);
 381       if (optchar == -1)
 382         break;
 383
 384       switch (optchar)
 385         {
 386         default:
 387           usage (EXIT_FAILURE);
 388
 389         case 'H':
 390         case HASHSIZE_OPTION:
 391           /* -H was supported in 1.4.x, but is a no-op now.  FIXME -
 392              remove support for -H after 2.0.  */
 393           error (0, 0, _("Warning: `%s' is deprecated"),
 394                  optchar == 'H' ? "-H" : "--hashsize");
 395           break;
 396
 397         case 'S':
 398         case 'T':
 399           /* Compatibility junk: options that other implementations
 400              support, but which we ignore as no-ops and don't list in
 401              --help.  */
 402           error (0, 0, _("Warning: `-%c' is deprecated"),
 403                  optchar);
 404           break;
 405
 406         case WORD_REGEXP_OPTION:
 407           /* Supported in 1.4.x as -W, but no longer present.  */
 408           error (0, 0, _("Warning: `%s' is deprecated"), "--word-regexp");
 409           break;
 410
 411         case 's':
 412           optchar = SYNCOUTPUT_OPTION;
 413           optarg = "1";
 414           /* fall through */
 415         case 'D':
 416         case 'U':
 417         case 'm':
 418         case 'p':
 419         case 'r':
 420         case 't':
 421         case POPDEF_OPTION:
 422         case SYNCOUTPUT_OPTION:
 423         case TRACEOFF_OPTION:
 424         case UNLOAD_MODULE_OPTION:
 425         defer:
 426           /* Arguments that cannot be handled until later are accumulated.  */
 427
 428           defn = (deferred *) xmalloc (sizeof *defn);
 429           defn->code = optchar;
 430           defn->value = optarg;
 431           defn->next = NULL;
 432
 433           if (head == NULL)
 434             head = defn;
 435           else
 436             tail->next = defn;
 437           tail = defn;
 438           break;
 439
 440         case '\1':
 441           seen_file = true;
 442           goto defer;
 443
 444         case 'B':
 445           /* In 1.4.x, -B<num> was a no-op option for compatibility with
 446              Solaris m4.  Warn if optarg is all numeric.  FIXME -
 447              silence this warning after 2.0.  */
 448           if (isdigit (to_uchar (*optarg)))
 449             {
 450               char *end;
 451               errno = 0;
 452               strtol (optarg, &end, 10);
 453               if (*end == '\0' && errno == 0)
 454                 error (0, 0, _("Warning: recommend using `-B ./%s' instead"),
 455                        optarg);
 456             }
 457           /* fall through */
 458         case PREPEND_INCLUDE_OPTION:
 459           m4_add_include_directory (context, optarg, true);
 460           break;
 461
 462         case 'E':
 463           m4_debug_decode (context, "-d");
 464           if (m4_get_fatal_warnings_opt (context))
 465             m4_set_warnings_exit_opt (context, true);
 466           else
 467             m4_set_fatal_warnings_opt (context, true);
 468           break;
 469
 470         case 'F':
 471           frozen_file_to_write = optarg;
 472           break;
 473
 474         case 'G':
 475           m4_set_posixly_correct_opt (context, true);
 476           break;
 477
 478         case 'I':
 479           m4_add_include_directory (context, optarg, false);
 480           break;
 481
 482         case 'L':
 483           size = size_opt (optarg, oi, optchar);
 484           if (!size)
 485             size = SIZE_MAX;
 486           m4_set_nesting_limit_opt (context, size);
 487           break;
 488
 489         case 'M':
 490           if (lt_dlinsertsearchdir (lt_dlgetsearchpath (), optarg) != 0)
 491             {
 492               const char *dlerr = lt_dlerror ();
 493               if (dlerr == NULL)
 494                 m4_error (context, EXIT_FAILURE, 0, NULL,
 495                           _("failed to add search directory `%s'"),
 496                           optarg);
 497               else
 498                 m4_error (context, EXIT_FAILURE, 0, NULL,
 499                           _("failed to add search directory `%s': %s"),
 500                           optarg, dlerr);
 501             }
 502           break;
 503
 504         case 'P':
 505           m4_set_prefix_builtins_opt (context, true);
 506           break;
 507
 508         case 'Q':
 509           m4_set_suppress_warnings_opt (context, true);
 510           break;
 511
 512         case 'R':
 513           frozen_file_to_read = optarg;
 514           break;
 515
 516         case 'W':
 517           /* FIXME - should W take an optional argument, to allow -Wall,
 518              -Wnone, -Werror, -Wcategory, -Wno-category?  If so, then have
 519              -W == -Wall.  */
 520           m4_set_suppress_warnings_opt (context, false);
 521           break;
 522
 523         case 'b':
 524           interactive = INTERACTIVE_NO;
 525           break;
 526
 527         case 'c':
 528           m4_set_discard_comments_opt (context, true);
 529           break;
 530
 531         case 'd':
 532           /* Staggered handling of 'd', since -dm is useful prior to
 533              first file and prior to reloading, but other -d must also
 534              have effect between files.  */
 535           if (seen_file || frozen_file_to_read)
 536             goto defer;
 537           if (m4_debug_decode (context, optarg) < 0)
 538             error (0, 0, _("bad debug flags: `%s'"), optarg);
 539           break;
 540
 541         case 'e':
 542           error (0, 0, _("Warning: `%s' is deprecated, use `%s' instead"),
 543                  "-e", "-i");
 544           /* fall through */
 545         case 'i':
 546           interactive = INTERACTIVE_YES;
 547           break;
 548
 549         case 'g':
 550           m4_set_posixly_correct_opt (context, false);
 551           break;
 552
 553         case ARGLENGTH_OPTION:
 554           error (0, 0, _("Warning: `%s' is deprecated, use `%s' instead"),
 555                  "--arglength", "--debuglen");
 556           /* fall through */
 557         case 'l':
 558           size = size_opt (optarg, oi, optchar);
 559           if (!size)
 560             size = SIZE_MAX;
 561           m4_set_max_debug_arg_length_opt (context, size);
 562           break;
 563
 564         case 'o':
 565         case ERROR_OUTPUT_OPTION:
 566           /* FIXME: -o is inconsistent with other tools' use of
 567              -o/--output for creating an output file instead of using
 568              stdout, and --error-output is misnamed since it does not
 569              affect error messages to stderr.  Change the meaning of -o
 570              after 2.1.  */
 571           error (0, 0, _("Warning: `%s' is deprecated, use `%s' instead"),
 572                  optchar == 'o' ? "-o" : "--error-output", "--debugfile");
 573           /* fall through */
 574         case DEBUGFILE_OPTION:
 575           /* Don't call m4_debug_set_output here, as it has side effects.  */
 576           debugfile = optarg;
 577           break;
 578
 579         case IMPORT_ENVIRONMENT_OPTION:
 580           import_environment = true;
 581           break;
 582
 583         case SAFER_OPTION:
 584           m4_set_safer_opt (context, true);
 585           break;
 586
 587         case VERSION_OPTION:
 588           version_etc (stdout, PACKAGE, PACKAGE_NAME, VERSION, AUTHORS, NULL);
 589           exit (EXIT_SUCCESS);
 590           break;
 591
 592         case HELP_OPTION:
 593           usage (EXIT_SUCCESS);
 594           break;
 595         }
 596     }
 597
 598   /* Interactive if specified, or if no input files and stdin and
 599      stderr are terminals, to match sh behavior.  Interactive mode
 600      means unbuffered output, and interrupts ignored.  */
 601
 602   m4_set_interactive_opt (context, (interactive == INTERACTIVE_YES
 603                                     || (interactive == INTERACTIVE_UNKNOWN
 604                                         && optind == argc && !seen_file
 605                                         && isatty (STDIN_FILENO)
 606                                         && isatty (STDERR_FILENO))));
 607   if (m4_get_interactive_opt (context))
 608     {
 609       signal (SIGINT, SIG_IGN);
 610       setbuf (stdout, NULL);
 611     }
 612   else
 613     signal (SIGPIPE, SIG_DFL);
 614
 615
 616   /* Do the basic initializations.  */
 617   if (debugfile && !m4_debug_set_output (context, NULL, debugfile))
 618     m4_error (context, 0, errno, NULL, _("cannot set debug file `%s'"),
 619               debugfile);
 620   m4_input_init (context);
 621   m4_output_init (context);
 622   m4_include_env_init (context);
 623
 624   if (frozen_file_to_read)
 625     reload_frozen_state (context, frozen_file_to_read);
 626   else
 627     {
 628       m4_module_load (context, "m4", NULL);
 629       if (m4_get_posixly_correct_opt (context))
 630         m4_module_load (context, "traditional", NULL);
 631       else
 632         m4_module_load (context, "gnu", NULL);
 633     }
 634
 635   /* Import environment variables as macros.  The definition are
 636      prepended to the macro definition list, so -U can override
 637      environment variables. */
 638
 639   if (import_environment)
 640     {
 641       char *const *env;
 642
 643       for (env = envp; *env != NULL; env++)
 644         {
 645           defn = (deferred *) xmalloc (sizeof *defn);
 646           defn->code = 'D';
 647           defn->value = *env;
 648           defn->next = head;
 649           head = defn;
 650         }
 651     }
 652
 653   /* Handle deferred command line macro definitions.  Must come after
 654      initialization of the symbol table.  */
 655   defn = head;
 656   while (defn != NULL)
 657     {
 658       deferred *next;
 659       const char *arg = defn->value;
 660
 661       switch (defn->code)
 662         {
 663         case 'D':
 664         case 'p':
 665           {
 666             m4_symbol_value *value = m4_symbol_value_create ();
 667
 668             const char *str = strchr (arg, '=');
 669             size_t len = str ? str - arg : strlen (arg);
 670
 671             m4_set_symbol_value_text (value, xstrdup (str ? str + 1 : ""),
 672                                       str ? strlen (str + 1) : 0, 0);
 673
 674             if (defn->code == 'D')
 675               m4_symbol_define (M4SYMTAB, arg, len, value);
 676             else
 677               m4_symbol_pushdef (M4SYMTAB, arg, len, value);
 678           }
 679           break;
 680
 681         case 'U':
 682           m4_symbol_delete (M4SYMTAB, arg, strlen (arg));
 683           break;
 684
 685         case 'd':
 686           if (m4_debug_decode (context, arg) < 0)
 687             error (0, 0, _("bad debug flags: `%s'"), arg);
 688           break;
 689
 690         case 'm':
 691           /* FIXME - should loading a module result in output?  */
 692           m4_module_load (context, arg, NULL);
 693           break;
 694
 695         case 'r':
 696           m4_set_regexp_syntax_opt (context, m4_regexp_syntax_encode (arg));
 697           if (m4_get_regexp_syntax_opt (context) < 0)
 698             m4_error (context, EXIT_FAILURE, 0, NULL,
 699                       _("bad regexp syntax option: `%s'"), arg);
 700           break;
 701
 702         case 't':
 703           m4_set_symbol_name_traced (M4SYMTAB, arg, strlen (arg), true);
 704           break;
 705
 706         case '\1':
 707           process_file (context, arg);
 708           break;
 709
 710         case POPDEF_OPTION:
 711           {
 712             size_t len = strlen (arg);
 713             if (m4_symbol_lookup (M4SYMTAB, arg, len))
 714               m4_symbol_popdef (M4SYMTAB, arg, len);
 715           }
 716           break;
 717
 718         case SYNCOUTPUT_OPTION:
 719           {
 720             bool previous = m4_get_syncoutput_opt (context);
 721             m4_call_info info = {0};
 722             info.name = "--syncoutput";
 723             info.name_len = strlen (info.name);
 724             m4_set_syncoutput_opt (context,
 725                                    m4_parse_truth_arg (context, &info, arg,
 726                                                        previous));
 727           }
 728           break;
 729
 730         case TRACEOFF_OPTION:
 731           m4_set_symbol_name_traced (M4SYMTAB, arg, strlen (arg), false);
 732           break;
 733
 734         case UNLOAD_MODULE_OPTION:
 735           /* FIXME - should unloading a module result in output?  */
 736           m4_module_unload (context, arg, NULL);
 737           break;
 738
 739         default:
 740           assert (!"INTERNAL ERROR: bad code in deferred arguments");
 741           abort ();
 742         }
 743
 744       next = defn->next;
 745       free (defn);
 746       defn = next;
 747     }
 748
 749   /* Handle remaining input files.  Each file is pushed on the input,
 750      and the input read.  */
 751
 752   if (optind == argc && !seen_file)
 753     process_file (context, "-");
 754   else
 755     for (; optind < argc; optind++)
 756       process_file (context, argv[optind]);
 757
 758   /* Now handle wrapup text.
 759      FIXME - when -F is in effect, should wrapped text be frozen?  */
 760   while (m4_pop_wrapup (context))
 761     m4_macro_expand_input (context);
 762
 763   if (frozen_file_to_write)
 764     produce_frozen_state (context, frozen_file_to_write);
 765   else
 766     {
 767       m4_make_diversion (context, 0);
 768       m4_undivert_all (context);
 769     }
 770
 771   /* The remaining cleanup functions systematically free all of the
 772      memory we still have pointers to.  By definition, if there is
 773      anything left when we're done: it was caused by a memory leak.
 774      Strictly, we don't need to do this, but it makes leak detection
 775      a whole lot easier!  */
 776
 777   m4__module_exit (context);
 778   m4_output_exit ();
 779   m4_input_exit ();
 780
 781   /* Change debug stream back to stderr, to force flushing the debug
 782      stream and detect any errors it might have encountered.  The
 783      three standard streams are closed by close_stdin.  */
 784   m4_debug_set_output (context, NULL, NULL);
 785
 786   exit_status = m4_get_exit_status (context);
 787   m4_delete (context);
 788
 789   m4_hash_exit ();
 790   quotearg_free ();
 791
 792 #ifdef USE_STACKOVF
 793   stackovf_exit ();
 794 #endif
 795
 796   exit (exit_status);
 797 }