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     xfprintf (stderr, "Try `%s --help' for more information.\n", program_name);
 141   else
 142     {
 143       xprintf ("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       xprintf ("\
 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       xprintf ("\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 #ifdef DEBUG_REGEX
 322 FILE *trace_file;
 323 #endif /* DEBUG_REGEX */
 324
 325 int
 326 main (int argc, char *const *argv, char *const *envp)
 327 {
 328   macro_definition *head;       /* head of deferred argument list */
 329   macro_definition *tail;
 330   macro_definition *defn;
 331   int optchar;                  /* option character */
 332
 333   macro_definition *defines;
 334   bool interactive = false;
 335   bool seen_file = false;
 336   const char *debugfile = NULL;
 337   const char *frozen_file_to_read = NULL;
 338   const char *frozen_file_to_write = NULL;
 339   const char *macro_sequence = "";
 340
 341   program_name = argv[0];
 342   retcode = EXIT_SUCCESS;
 343   atexit (close_stdin);
 344
 345 #ifdef DEBUG_REGEX
 346   {
 347     const char *name = getenv ("M4_TRACE_FILE");
 348     if (name)
 349       trace_file = fopen (name, "a");
 350     if (trace_file)
 351       fputs ("m4:\n", trace_file);
 352   }
 353 #endif /* DEBUG_REGEX */
 354
 355   include_init ();
 356   debug_init ();
 357 #ifdef USE_STACKOVF
 358   setup_stackovf_trap (argv, envp, stackovf_handler);
 359 #endif
 360
 361   /* First, we decode the arguments, to size up tables and stuff.  */
 362
 363   head = tail = NULL;
 364
 365   while ((optchar = getopt_long (argc, (char **) argv, OPTSTRING,
 366                                  long_options, NULL)) != -1)
 367     switch (optchar)
 368       {
 369       default:
 370         usage (EXIT_FAILURE);
 371
 372       case 'B':
 373       case 'S':
 374       case 'T':
 375         /* Compatibility junk: options that other implementations
 376            support, but which we ignore as no-ops and don't list in
 377            --help.  */
 378         error (0, 0, "Warning: `m4 -%c' may be removed in a future release",
 379                optchar);
 380         break;
 381
 382       case 'N':
 383       case DIVERSIONS_OPTION:
 384         /* -N became an obsolete no-op in 1.4.x.  */
 385         error (0, 0, "Warning: `m4 %s' is deprecated",
 386                optchar == 'N' ? "-N" : "--diversions");
 387
 388       case 'D':
 389       case 'U':
 390       case 's':
 391       case 't':
 392       case '\1':
 393         /* Arguments that cannot be handled until later are accumulated.  */
 394
 395         defn = (macro_definition *) xmalloc (sizeof (macro_definition));
 396         defn->code = optchar;
 397         defn->arg = optarg;
 398         defn->next = NULL;
 399
 400         if (head == NULL)
 401           head = defn;
 402         else
 403           tail->next = defn;
 404         tail = defn;
 405
 406         break;
 407
 408       case 'E':
 409         if (! fatal_warnings)
 410           fatal_warnings = true;
 411         else
 412           warning_status = EXIT_FAILURE;
 413         break;
 414
 415       case 'F':
 416         frozen_file_to_write = optarg;
 417         break;
 418
 419       case 'G':
 420         no_gnu_extensions = 1;
 421         break;
 422
 423       case 'H':
 424         hash_table_size = atol (optarg);
 425         if (hash_table_size == 0)
 426           hash_table_size = HASHMAX;
 427         break;
 428
 429       case 'I':
 430         add_include_directory (optarg);
 431         break;
 432
 433       case 'L':
 434         nesting_limit = atoi (optarg);
 435         break;
 436
 437       case 'P':
 438         prefix_all_builtins = 1;
 439         break;
 440
 441       case 'Q':
 442         suppress_warnings = 1;
 443         break;
 444
 445       case 'R':
 446         frozen_file_to_read = optarg;
 447         break;
 448
 449 #ifdef ENABLE_CHANGEWORD
 450       case 'W':
 451         user_word_regexp = optarg;
 452         break;
 453 #endif
 454
 455       case 'd':
 456         debug_level = debug_decode (optarg);
 457         if (debug_level < 0)
 458           {
 459             error (0, 0, "bad debug flags: `%s'", optarg);
 460             debug_level = 0;
 461           }
 462         break;
 463
 464       case 'e':
 465         error (0, 0, "Warning: `m4 -e' is deprecated, use `-i' instead");
 466         /* fall through */
 467       case 'i':
 468         interactive = true;
 469         break;
 470
 471       case 'l':
 472         max_debug_argument_length = atoi (optarg);
 473         if (max_debug_argument_length <= 0)
 474           max_debug_argument_length = 0;
 475         break;
 476
 477       case 'o':
 478         /* -o/--error-output are deprecated synonyms of --debugfile,
 479            but don't issue a deprecation warning until autoconf 2.61
 480            or later is more widely established, as such a warning
 481            would interfere with all earlier versions of autoconf.  */
 482       case DEBUGFILE_OPTION:
 483         /* Don't call debug_set_output here, as it has side effects.  */
 484         debugfile = optarg;
 485         break;
 486
 487       case WARN_MACRO_SEQUENCE_OPTION:
 488          /* Don't call set_macro_sequence here, as it can exit.
 489             --warn-macro-sequence sets optarg to NULL (which uses the
 490             default regexp); --warn-macro-sequence= sets optarg to ""
 491             (which disables these warnings).  */
 492         macro_sequence = optarg;
 493         break;
 494
 495       case VERSION_OPTION:
 496         version_etc (stdout, PACKAGE, PACKAGE_NAME, VERSION, AUTHORS, NULL);
 497         exit (EXIT_SUCCESS);
 498         break;
 499
 500       case HELP_OPTION:
 501         usage (EXIT_SUCCESS);
 502         break;
 503       }
 504
 505   defines = head;
 506
 507   /* Do the basic initializations.  */
 508   if (debugfile && !debug_set_output (debugfile))
 509     M4ERROR ((0, errno, "cannot set debug file `%s'", debugfile));
 510
 511   input_init ();
 512   output_init ();
 513   symtab_init ();
 514   set_macro_sequence (macro_sequence);
 515   include_env_init ();
 516
 517   if (frozen_file_to_read)
 518     reload_frozen_state (frozen_file_to_read);
 519   else
 520     builtin_init ();
 521
 522   /* Interactive mode means unbuffered output, and interrupts ignored.  */
 523
 524   if (interactive)
 525     {
 526       signal (SIGINT, SIG_IGN);
 527       setbuf (stdout, (char *) NULL);
 528     }
 529
 530   /* Handle deferred command line macro definitions.  Must come after
 531      initialization of the symbol table.  */
 532
 533   while (defines != NULL)
 534     {
 535       macro_definition *next;
 536       symbol *sym;
 537
 538       switch (defines->code)
 539         {
 540         case 'D':
 541           {
 542             /* defines->arg is read-only, so we need a copy.  */
 543             char *macro_name = xstrdup (defines->arg);
 544             char *macro_value = strchr (macro_name, '=');
 545             if (macro_value)
 546               *macro_value++ = '\0';
 547             define_user_macro (macro_name, macro_value, SYMBOL_INSERT);
 548             free (macro_name);
 549           }
 550           break;
 551
 552         case 'U':
 553           lookup_symbol (defines->arg, SYMBOL_DELETE);
 554           break;
 555
 556         case 't':
 557           sym = lookup_symbol (defines->arg, SYMBOL_INSERT);
 558           SYMBOL_TRACED (sym) = true;
 559           break;
 560
 561         case 's':
 562           sync_output = 1;
 563           break;
 564
 565         case '\1':
 566           seen_file = true;
 567           process_file (defines->arg);
 568           break;
 569
 570         default:
 571           M4ERROR ((0, 0, "INTERNAL ERROR: bad code in deferred arguments"));
 572           abort ();
 573         }
 574
 575       next = defines->next;
 576       free (defines);
 577       defines = next;
 578     }
 579
 580   /* Handle remaining input files.  Each file is pushed on the input,
 581      and the input read.  Wrapup text is handled separately later.  */
 582
 583   if (optind == argc && !seen_file)
 584     process_file ("-");
 585   else
 586     for (; optind < argc; optind++)
 587       process_file (argv[optind]);
 588
 589   /* Now handle wrapup text.  */
 590
 591   while (pop_wrapup ())
 592     expand_input ();
 593
 594   /* Change debug stream back to stderr, to force flushing the debug
 595      stream and detect any errors it might have encountered.  The
 596      three standard streams are closed by close_stdin.  */
 597   debug_set_output (NULL);
 598
 599   if (frozen_file_to_write)
 600     produce_frozen_state (frozen_file_to_write);
 601   else
 602     {
 603       make_diversion (0);
 604       undivert_all ();
 605     }
 606   output_exit ();
 607   free_regex ();
 608 #ifdef DEBUG_REGEX
 609   if (trace_file)
 610     fclose (trace_file);
 611 #endif /* DEBUG_REGEX */
 612   exit (retcode);
 613 }