src/m4.c

   1 /* GNU m4 -- A simple macro processor
   2
   3    Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006, 2007
   4    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 "m4.h"
  23
  24 #include <getopt.h>
  25 #include <limits.h>
  26 #include <signal.h>
  27
  28 #include "version-etc.h"
  29
  30 #define AUTHORS "Rene' Seindal"
  31
  32 static void usage (int);
  33
  34 /* Enable sync output for /lib/cpp (-s).  */
  35 int sync_output = 0;
  36
  37 /* Debug (-d[flags]).  */
  38 int debug_level = 0;
  39
  40 /* Hash table size (should be a prime) (-Hsize).  */
  41 size_t hash_table_size = HASHMAX;
  42
  43 /* Disable GNU extensions (-G).  */
  44 int no_gnu_extensions = 0;
  45
  46 /* Prefix all builtin functions by `m4_'.  */
  47 int prefix_all_builtins = 0;
  48
  49 /* Max length of arguments in trace output (-lsize).  */
  50 int max_debug_argument_length = 0;
  51
  52 /* Suppress warnings about missing arguments.  */
  53 int suppress_warnings = 0;
  54
  55 /* If true, then warnings affect exit status.  */
  56 static bool fatal_warnings = false;
  57
  58 /* If not zero, then value of exit status for warning diagnostics.  */
  59 int warning_status = 0;
  60
  61 /* Artificial limit for expansion_level in macro.c.  */
  62 int nesting_limit = 1024;
  63
  64 #ifdef ENABLE_CHANGEWORD
  65 /* User provided regexp for describing m4 words.  */
  66 const char *user_word_regexp = "";
  67 #endif
  68
  69 /* The name this program was run with. */
  70 const char *program_name;
  71
  72 /* Global catchall for any errors that should affect final error status, but
  73    where we try to continue execution in the meantime.  */
  74 int retcode;
  75
  76 struct macro_definition
  77 {
  78   struct macro_definition *next;
  79   int code;                     /* D, U, s, t, or '\1' */
  80   const char *arg;
  81 };
  82 typedef struct macro_definition macro_definition;
  83 \f
  84 /* Error handling functions.  */
  85
  86 /*-----------------------.
  87 | Wrapper around error.  |
  88 `-----------------------*/
  89
  90 void
  91 m4_error (int status, int errnum, const char *format, ...)
  92 {
  93   va_list args;
  94   va_start (args, format);
  95   verror_at_line (status, errnum, current_line ? current_file : NULL,
  96                   current_line, format, args);
  97   if (fatal_warnings && ! retcode)
  98     retcode = EXIT_FAILURE;
  99 }
 100
 101 /*-------------------------------.
 102 | Wrapper around error_at_line.  |
 103 `-------------------------------*/
 104
 105 void
 106 m4_error_at_line (int status, int errnum, const char *file, int line,
 107                   const char *format, ...)
 108 {
 109   va_list args;
 110   va_start (args, format);
 111   verror_at_line (status, errnum, line ? file : NULL, line, format, args);
 112   if (fatal_warnings && ! retcode)
 113     retcode = EXIT_FAILURE;
 114 }
 115
 116 #ifdef USE_STACKOVF
 117
 118 /*---------------------------------------.
 119 | Tell user stack overflowed and abort.  |
 120 `---------------------------------------*/
 121
 122 static void
 123 stackovf_handler (void)
 124 {
 125   M4ERROR ((EXIT_FAILURE, 0,
 126             "ERROR: stack overflow.  (Infinite define recursion?)"));
 127 }
 128
 129 #endif /* USE_STACKOV */
 130 \f
 131
 132 /*---------------------------------------------.
 133 | Print a usage message and exit with STATUS.  |
 134 `---------------------------------------------*/
 135
 136 static void
 137 usage (int status)
 138 {
 139   if (status != EXIT_SUCCESS)
 140     fprintf (stderr, "Try `%s --help' for more information.\n", program_name);
 141   else
 142     {
 143       printf ("Usage: %s [OPTION]... [FILE]...\n", program_name);
 144       fputs ("\
 145 Process macros in FILEs.  If no FILE or if FILE is `-', standard input\n\
 146 is read.\n\
 147 ", stdout);
 148       fputs ("\
 149 \n\
 150 Mandatory or optional arguments to long options are mandatory or optional\n\
 151 for short options too.\n\
 152 \n\
 153 Operation modes:\n\
 154       --help                   display this help and exit\n\
 155       --version                output version information and exit\n\
 156 ", stdout);
 157       printf ("\
 158   -E, --fatal-warnings         once: warnings become errors, twice: stop\n\
 159                                execution at first error\n\
 160   -i, --interactive            unbuffer output, ignore interrupts\n\
 161   -P, --prefix-builtins        force a `m4_' prefix to all builtins\n\
 162   -Q, --quiet, --silent        suppress some warnings for builtins\n\
 163       --warn-macro-sequence[=REGEXP]\n\
 164                                warn if macro definition matches REGEXP,\n\
 165                                default %s\n\
 166 ", DEFAULT_MACRO_SEQUENCE);
 167 #ifdef ENABLE_CHANGEWORD
 168       fputs ("\
 169   -W, --word-regexp=REGEXP     use REGEXP for macro name syntax\n\
 170 ", stdout);
 171 #endif
 172       fputs ("\
 173 \n\
 174 Preprocessor features:\n\
 175   -D, --define=NAME[=VALUE]    define NAME as having VALUE, or empty\n\
 176   -I, --include=DIRECTORY      append DIRECTORY to include path\n\
 177   -s, --synclines              generate `#line NUM \"FILE\"' lines\n\
 178   -U, --undefine=NAME          undefine NAME\n\
 179 ", stdout);
 180       fputs ("\
 181 \n\
 182 Limits control:\n\
 183   -G, --traditional            suppress all GNU extensions\n\
 184   -H, --hashsize=PRIME         set symbol lookup hash table size [509]\n\
 185   -L, --nesting-limit=NUMBER   change artificial nesting limit [1024]\n\
 186 ", stdout);
 187       fputs ("\
 188 \n\
 189 Frozen state files:\n\
 190   -F, --freeze-state=FILE      produce a frozen state on FILE at end\n\
 191   -R, --reload-state=FILE      reload a frozen state from FILE at start\n\
 192 ", stdout);
 193       fputs ("\
 194 \n\
 195 Debugging:\n\
 196   -d, --debug[=FLAGS]          set debug level (no FLAGS implies `aeq')\n\
 197       --debugfile=FILE         redirect debug and trace output\n\
 198   -l, --arglength=NUM          restrict macro tracing size\n\
 199   -t, --trace=NAME             trace NAME when it is defined\n\
 200 ", stdout);
 201       fputs ("\
 202 \n\
 203 FLAGS is any of:\n\
 204   a   show actual arguments\n\
 205   c   show before collect, after collect and after call\n\
 206   e   show expansion\n\
 207   f   say current input file name\n\
 208   i   show changes in input files\n\
 209   l   say current input line number\n\
 210   p   show results of path searches\n\
 211   q   quote values as necessary, with a or e flag\n\
 212   t   trace for all macro calls, not only traceon'ed\n\
 213   x   add a unique macro call id, useful with c flag\n\
 214   V   shorthand for all of the above flags\n\
 215 ", stdout);
 216       fputs ("\
 217 \n\
 218 If defined, the environment variable `M4PATH' is a colon-separated list\n\
 219 of directories included after any specified by `-I'.\n\
 220 ", stdout);
 221       fputs ("\
 222 \n\
 223 Exit status is 0 for success, 1 for failure, 63 for frozen file version\n\
 224 mismatch, or whatever value was passed to the m4exit macro.\n\
 225 ", stdout);
 226       printf ("\nReport bugs to <%s>.\n", PACKAGE_BUGREPORT);
 227     }
 228   exit (status);
 229 }
 230
 231 /*--------------------------------------.
 232 | Decode options and launch execution.  |
 233 `--------------------------------------*/
 234
 235 /* For long options that have no equivalent short option, use a
 236    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
 237 enum
 238 {
 239   DEBUGFILE_OPTION = CHAR_MAX + 1,      /* no short opt */
 240   DIVERSIONS_OPTION,                    /* not quite -N, because of message */
 241   WARN_MACRO_SEQUENCE_OPTION,           /* no short opt */
 242
 243   HELP_OPTION,                          /* no short opt */
 244   VERSION_OPTION                        /* no short opt */
 245 };
 246
 247 static const struct option long_options[] =
 248 {
 249   {"arglength", required_argument, NULL, 'l'},
 250   {"debug", optional_argument, NULL, 'd'},
 251   {"define", required_argument, NULL, 'D'},
 252   {"error-output", required_argument, NULL, 'o'}, /* FIXME: deprecate in 2.0 */
 253   {"fatal-warnings", no_argument, NULL, 'E'},
 254   {"freeze-state", required_argument, NULL, 'F'},
 255   {"hashsize", required_argument, NULL, 'H'},
 256   {"include", required_argument, NULL, 'I'},
 257   {"interactive", no_argument, NULL, 'i'},
 258   {"nesting-limit", required_argument, NULL, 'L'},
 259   {"prefix-builtins", no_argument, NULL, 'P'},
 260   {"quiet", no_argument, NULL, 'Q'},
 261   {"reload-state", required_argument, NULL, 'R'},
 262   {"silent", no_argument, NULL, 'Q'},
 263   {"synclines", no_argument, NULL, 's'},
 264   {"trace", required_argument, NULL, 't'},
 265   {"traditional", no_argument, NULL, 'G'},
 266   {"undefine", required_argument, NULL, 'U'},
 267   {"word-regexp", required_argument, NULL, 'W'},
 268
 269   {"debugfile", required_argument, NULL, DEBUGFILE_OPTION},
 270   {"diversions", required_argument, NULL, DIVERSIONS_OPTION},
 271   {"warn-macro-sequence", optional_argument, NULL, WARN_MACRO_SEQUENCE_OPTION},
 272
 273   {"help", no_argument, NULL, HELP_OPTION},
 274   {"version", no_argument, NULL, VERSION_OPTION},
 275
 276   { NULL, 0, NULL, 0 },
 277 };
 278
 279 /* Process a command line file NAME, and return true only if it was
 280    stdin.  */
 281 static void
 282 process_file (const char *name)
 283 {
 284   if (strcmp (name, "-") == 0)
 285     {
 286       /* If stdin is a terminal, we want to allow 'm4 - file -'
 287          to read input from stdin twice, like GNU cat.  Besides,
 288          there is no point closing stdin before wrapped text, to
 289          minimize bugs in syscmd called from wrapped text.  */
 290       push_file (stdin, "stdin", false);
 291     }
 292   else
 293     {
 294       char *full_name;
 295       FILE *fp = m4_path_search (name, &full_name);
 296       if (fp == NULL)
 297         {
 298           error (0, errno, "%s", name);
 299           /* Set the status to EXIT_FAILURE, even though we
 300              continue to process files after a missing file.  */
 301           retcode = EXIT_FAILURE;
 302           return;
 303         }
 304       push_file (fp, full_name, true);
 305       free (full_name);
 306     }
 307   expand_input ();
 308 }
 309
 310 /* POSIX requires only -D, -U, and -s; and says that the first two
 311    must be recognized when interspersed with file names.  Traditional
 312    behavior also handles -s between files.  Starting OPTSTRING with
 313    '-' forces getopt_long to hand back file names as arguments to opt
 314    '\1', rather than reordering the command line.  */
 315 #ifdef ENABLE_CHANGEWORD
 316 #define OPTSTRING "-B:D:EF:GH:I:L:N:PQR:S:T:U:W:d::eil:o:st:"
 317 #else
 318 #define OPTSTRING "-B:D:EF:GH:I:L:N:PQR:S:T:U:d::eil:o:st:"
 319 #endif
 320
 321 int
 322 main (int argc, char *const *argv, char *const *envp)
 323 {
 324   macro_definition *head;       /* head of deferred argument list */
 325   macro_definition *tail;
 326   macro_definition *defn;
 327   int optchar;                  /* option character */
 328
 329   macro_definition *defines;
 330   bool interactive = false;
 331   bool seen_file = false;
 332   const char *debugfile = NULL;
 333   const char *frozen_file_to_read = NULL;
 334   const char *frozen_file_to_write = NULL;
 335   const char *macro_sequence = "";
 336
 337   program_name = argv[0];
 338   retcode = EXIT_SUCCESS;
 339   atexit (close_stdin);
 340
 341   include_init ();
 342   debug_init ();
 343 #ifdef USE_STACKOVF
 344   setup_stackovf_trap (argv, envp, stackovf_handler);
 345 #endif
 346
 347   /* First, we decode the arguments, to size up tables and stuff.  */
 348
 349   head = tail = NULL;
 350
 351   while ((optchar = getopt_long (argc, (char **) argv, OPTSTRING,
 352                                  long_options, NULL)) != -1)
 353     switch (optchar)
 354       {
 355       default:
 356         usage (EXIT_FAILURE);
 357
 358       case 'B':
 359       case 'S':
 360       case 'T':
 361         /* Compatibility junk: options that other implementations
 362            support, but which we ignore as no-ops and don't list in
 363            --help.  */
 364         error (0, 0, "Warning: `m4 -%c' may be removed in a future release",
 365                optchar);
 366         break;
 367
 368       case 'N':
 369       case DIVERSIONS_OPTION:
 370         /* -N became an obsolete no-op in 1.4.x.  */
 371         error (0, 0, "Warning: `m4 %s' is deprecated",
 372                optchar == 'N' ? "-N" : "--diversions");
 373
 374       case 'D':
 375       case 'U':
 376       case 's':
 377       case 't':
 378       case '\1':
 379         /* Arguments that cannot be handled until later are accumulated.  */
 380
 381         defn = (macro_definition *) xmalloc (sizeof (macro_definition));
 382         defn->code = optchar;
 383         defn->arg = optarg;
 384         defn->next = NULL;
 385
 386         if (head == NULL)
 387           head = defn;
 388         else
 389           tail->next = defn;
 390         tail = defn;
 391
 392         break;
 393
 394       case 'E':
 395         if (! fatal_warnings)
 396           fatal_warnings = true;
 397         else
 398           warning_status = EXIT_FAILURE;
 399         break;
 400
 401       case 'F':
 402         frozen_file_to_write = optarg;
 403         break;
 404
 405       case 'G':
 406         no_gnu_extensions = 1;
 407         break;
 408
 409       case 'H':
 410         hash_table_size = atol (optarg);
 411         if (hash_table_size == 0)
 412           hash_table_size = HASHMAX;
 413         break;
 414
 415       case 'I':
 416         add_include_directory (optarg);
 417         break;
 418
 419       case 'L':
 420         nesting_limit = atoi (optarg);
 421         break;
 422
 423       case 'P':
 424         prefix_all_builtins = 1;
 425         break;
 426
 427       case 'Q':
 428         suppress_warnings = 1;
 429         break;
 430
 431       case 'R':
 432         frozen_file_to_read = optarg;
 433         break;
 434
 435 #ifdef ENABLE_CHANGEWORD
 436       case 'W':
 437         user_word_regexp = optarg;
 438         break;
 439 #endif
 440
 441       case 'd':
 442         debug_level = debug_decode (optarg);
 443         if (debug_level < 0)
 444           {
 445             error (0, 0, "bad debug flags: `%s'", optarg);
 446             debug_level = 0;
 447           }
 448         break;
 449
 450       case 'e':
 451         error (0, 0, "Warning: `m4 -e' is deprecated, use `-i' instead");
 452         /* fall through */
 453       case 'i':
 454         interactive = true;
 455         break;
 456
 457       case 'l':
 458         max_debug_argument_length = atoi (optarg);
 459         if (max_debug_argument_length <= 0)
 460           max_debug_argument_length = 0;
 461         break;
 462
 463       case 'o':
 464         /* -o/--error-output are deprecated synonyms of --debugfile,
 465            but don't issue a deprecation warning until autoconf 2.61
 466            or later is more widely established, as such a warning
 467            would interfere with all earlier versions of autoconf.  */
 468       case DEBUGFILE_OPTION:
 469         /* Don't call debug_set_output here, as it has side effects.  */
 470         debugfile = optarg;
 471         break;
 472
 473       case WARN_MACRO_SEQUENCE_OPTION:
 474          /* Don't call set_macro_sequence here, as it can exit.
 475             --warn-macro-sequence sets optarg to NULL (which uses the
 476             default regexp); --warn-macro-sequence= sets optarg to ""
 477             (which disables these warnings).  */
 478         macro_sequence = optarg;
 479         break;
 480
 481       case VERSION_OPTION:
 482         version_etc (stdout, PACKAGE, PACKAGE_NAME, VERSION, AUTHORS, NULL);
 483         exit (EXIT_SUCCESS);
 484         break;
 485
 486       case HELP_OPTION:
 487         usage (EXIT_SUCCESS);
 488         break;
 489       }
 490
 491   defines = head;
 492
 493   /* Do the basic initializations.  */
 494   if (debugfile && !debug_set_output (debugfile))
 495     M4ERROR ((0, errno, "cannot set debug file `%s'", debugfile));
 496
 497   input_init ();
 498   output_init ();
 499   symtab_init ();
 500   set_macro_sequence (macro_sequence);
 501   include_env_init ();
 502
 503   if (frozen_file_to_read)
 504     reload_frozen_state (frozen_file_to_read);
 505   else
 506     builtin_init ();
 507
 508   /* Interactive mode means unbuffered output, and interrupts ignored.  */
 509
 510   if (interactive)
 511     {
 512       signal (SIGINT, SIG_IGN);
 513       setbuf (stdout, (char *) NULL);
 514     }
 515
 516   /* Handle deferred command line macro definitions.  Must come after
 517      initialization of the symbol table.  */
 518
 519   while (defines != NULL)
 520     {
 521       macro_definition *next;
 522       symbol *sym;
 523
 524       switch (defines->code)
 525         {
 526         case 'D':
 527           {
 528             /* defines->arg is read-only, so we need a copy.  */
 529             char *macro_name = xstrdup (defines->arg);
 530             char *macro_value = strchr (macro_name, '=');
 531             if (macro_value)
 532               *macro_value++ = '\0';
 533             define_user_macro (macro_name, macro_value, SYMBOL_INSERT);
 534             free (macro_name);
 535           }
 536           break;
 537
 538         case 'U':
 539           lookup_symbol (defines->arg, SYMBOL_DELETE);
 540           break;
 541
 542         case 't':
 543           sym = lookup_symbol (defines->arg, SYMBOL_INSERT);
 544           SYMBOL_TRACED (sym) = true;
 545           break;
 546
 547         case 's':
 548           sync_output = 1;
 549           break;
 550
 551         case '\1':
 552           seen_file = true;
 553           process_file (defines->arg);
 554           break;
 555
 556         default:
 557           M4ERROR ((0, 0, "INTERNAL ERROR: bad code in deferred arguments"));
 558           abort ();
 559         }
 560
 561       next = defines->next;
 562       free (defines);
 563       defines = next;
 564     }
 565
 566   /* Handle remaining input files.  Each file is pushed on the input,
 567      and the input read.  Wrapup text is handled separately later.  */
 568
 569   if (optind == argc && !seen_file)
 570     process_file ("-");
 571   else
 572     for (; optind < argc; optind++)
 573       process_file (argv[optind]);
 574
 575   /* Now handle wrapup text.  */
 576
 577   while (pop_wrapup ())
 578     expand_input ();
 579
 580   /* Change debug stream back to stderr, to force flushing the debug
 581      stream and detect any errors it might have encountered.  The
 582      three standard streams are closed by close_stdin.  */
 583   debug_set_output (NULL);
 584
 585   if (frozen_file_to_write)
 586     produce_frozen_state (frozen_file_to_write);
 587   else
 588     {
 589       make_diversion (0);
 590       undivert_all ();
 591     }
 592   output_exit ();
 593   free_regex ();
 594   exit (retcode);
 595 }