usr.bin/m4/eval.c

   1 /*      $OpenBSD: eval.c,v 1.66 2008/08/21 21:01:47 espie Exp $ */
   2 /*      $NetBSD: eval.c,v 1.7 1996/11/10 21:21:29 pk Exp $      */
   3
   4 /*
   5  * Copyright (c) 1989, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Ozan Yigit at York University.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 /*
  37  * eval.c
  38  * Facility: m4 macro processor
  39  * by: oz
  40  */
  41 #if HAVE_NBTOOL_CONFIG_H
  42 #include "nbtool_config.h"
  43 #endif
  44 #include <sys/cdefs.h>
  45 __RCSID("$NetBSD$");
  46
  47 #include <sys/types.h>
  48 #include <err.h>
  49 #include <errno.h>
  50 #include <limits.h>
  51 #include <unistd.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <stddef.h>
  55 #include <string.h>
  56 #include <fcntl.h>
  57 #include "mdef.h"
  58 #include "stdd.h"
  59 #include "extern.h"
  60 #include "pathnames.h"
  61
  62 static void     dodefn(const char *);
  63 static void     dopushdef(const char *, const char *);
  64 static void     dodump(const char *[], int);
  65 static void     dotrace(const char *[], int, int);
  66 static void     doifelse(const char *[], int);
  67 static int      doincl(const char *);
  68 static int      dopaste(const char *);
  69 static void     dochq(const char *[], int);
  70 static void     dochc(const char *[], int);
  71 static void     dom4wrap(const char *);
  72 static void     dodiv(int);
  73 static void     doundiv(const char *[], int);
  74 static void     dosub(const char *[], int);
  75 static void     map(char *, const char *, const char *, const char *);
  76 static const char *handledash(char *, char *, const char *);
  77 static void     expand_builtin(const char *[], int, int);
  78 static void     expand_macro(const char *[], int);
  79 static void     dump_one_def(const char *, struct macro_definition *);
  80
  81 unsigned long   expansion_id;
  82
  83 /*
  84  * eval - eval all macros and builtins calls
  85  *        argc - number of elements in argv.
  86  *        argv - element vector :
  87  *                      argv[0] = definition of a user
  88  *                                macro or NULL if built-in.
  89  *                      argv[1] = name of the macro or
  90  *                                built-in.
  91  *                      argv[2] = parameters to user-defined
  92  *                         .      macro or built-in.
  93  *                         .
  94  *
  95  * A call in the form of macro-or-builtin() will result in:
  96  *                      argv[0] = nullstr
  97  *                      argv[1] = macro-or-builtin
  98  *                      argv[2] = nullstr
  99  *
 100  * argc is 3 for macro-or-builtin() and 2 for macro-or-builtin
 101  */
 102 void
 103 eval(const char *argv[], int argc, int td, int is_traced)
 104 {
 105         size_t mark = SIZE_MAX;
 106
 107         expansion_id++;
 108         if (td & RECDEF)
 109                 m4errx(1, "expanding recursive definition for %s.", argv[1]);
 110         if (is_traced)
 111                 mark = trace(argv, argc, infile+ilevel);
 112         if (td == MACRTYPE)
 113                 expand_macro(argv, argc);
 114         else
 115                 expand_builtin(argv, argc, td);
 116         if (mark != SIZE_MAX)
 117                 finish_trace(mark);
 118 }
 119
 120 /*
 121  * expand_builtin - evaluate built-in macros.
 122  */
 123 void
 124 expand_builtin(const char *argv[], int argc, int td)
 125 {
 126         int c, n;
 127         int ac;
 128         static int sysval = 0;
 129
 130 #ifdef DEBUG
 131         printf("argc = %d\n", argc);
 132         for (n = 0; n < argc; n++)
 133                 printf("argv[%d] = %s\n", n, argv[n]);
 134         fflush(stdout);
 135 #endif
 136
 137  /*
 138   * if argc == 3 and argv[2] is null, then we
 139   * have macro-or-builtin() type call. We adjust
 140   * argc to avoid further checking..
 141   */
 142  /* we keep the initial value for those built-ins that differentiate
 143   * between builtin() and builtin.
 144   */
 145         ac = argc;
 146
 147         if (argc == 3 && !*(argv[2]) && !mimic_gnu)
 148                 argc--;
 149
 150         switch (td & TYPEMASK) {
 151
 152         case DEFITYPE:
 153                 if (argc > 2)
 154                         dodefine(argv[2], (argc > 3) ? argv[3] : null);
 155                 break;
 156
 157         case PUSDTYPE:
 158                 if (argc > 2)
 159                         dopushdef(argv[2], (argc > 3) ? argv[3] : null);
 160                 break;
 161
 162         case DUMPTYPE:
 163                 dodump(argv, argc);
 164                 break;
 165
 166         case TRACEONTYPE:
 167                 dotrace(argv, argc, 1);
 168                 break;
 169
 170         case TRACEOFFTYPE:
 171                 dotrace(argv, argc, 0);
 172                 break;
 173
 174         case EXPRTYPE:
 175         /*
 176          * doexpr - evaluate arithmetic
 177          * expression
 178          */
 179         {
 180                 int base = 10;
 181                 int maxdigits = 0;
 182                 const char *errstr;
 183
 184                 if (argc > 3) {
 185                         base = strtonum(argv[3], 2, 36, &errstr);
 186                         if (errstr) {
 187                                 m4errx(1, "expr: base %s invalid.", argv[3]);
 188                         }
 189                 }
 190                 if (argc > 4) {
 191                         maxdigits = strtonum(argv[4], 0, INT_MAX, &errstr);
 192                         if (errstr) {
 193                                 m4errx(1, "expr: maxdigits %s invalid.", argv[4]);
 194                         }
 195                 }
 196                 if (argc > 2)
 197                         pbnumbase(expr(argv[2]), base, maxdigits);
 198                 break;
 199         }
 200
 201         case IFELTYPE:
 202                 if (argc > 4)
 203                         doifelse(argv, argc);
 204                 break;
 205
 206         case IFDFTYPE:
 207         /*
 208          * doifdef - select one of two
 209          * alternatives based on the existence of
 210          * another definition
 211          */
 212                 if (argc > 3) {
 213                         if (lookup_macro_definition(argv[2]) != NULL)
 214                                 pbstr(argv[3]);
 215                         else if (argc > 4)
 216                                 pbstr(argv[4]);
 217                 }
 218                 break;
 219
 220         case LENGTYPE:
 221         /*
 222          * dolen - find the length of the
 223          * argument
 224          */
 225                 pbnum((argc > 2) ? strlen(argv[2]) : 0);
 226                 break;
 227
 228         case INCRTYPE:
 229         /*
 230          * doincr - increment the value of the
 231          * argument
 232          */
 233                 if (argc > 2)
 234                         pbnum(atoi(argv[2]) + 1);
 235                 break;
 236
 237         case DECRTYPE:
 238         /*
 239          * dodecr - decrement the value of the
 240          * argument
 241          */
 242                 if (argc > 2)
 243                         pbnum(atoi(argv[2]) - 1);
 244                 break;
 245
 246         case SYSCTYPE:
 247         /*
 248          * dosys - execute system command
 249          */
 250                 if (argc > 2) {
 251                         fflush(stdout);
 252                         sysval = system(argv[2]);
 253                 }
 254                 break;
 255
 256         case SYSVTYPE:
 257         /*
 258          * dosysval - return value of the last
 259          * system call.
 260          *
 261          */
 262                 pbnum(sysval);
 263                 break;
 264
 265         case ESYSCMDTYPE:
 266                 if (argc > 2)
 267                         doesyscmd(argv[2]);
 268                 break;
 269         case INCLTYPE:
 270                 if (argc > 2)
 271                         if (!doincl(argv[2]))
 272                                 err(1, "%s at line %lu: include(%s)",
 273                                     CURRENT_NAME, CURRENT_LINE, argv[2]);
 274                 break;
 275
 276         case SINCTYPE:
 277                 if (argc > 2)
 278                         (void) doincl(argv[2]);
 279                 break;
 280 #ifdef EXTENDED
 281         case PASTTYPE:
 282                 if (argc > 2)
 283                         if (!dopaste(argv[2]))
 284                                 err(1, "%s at line %lu: paste(%s)",
 285                                     CURRENT_NAME, CURRENT_LINE, argv[2]);
 286                 break;
 287
 288         case SPASTYPE:
 289                 if (argc > 2)
 290                         (void) dopaste(argv[2]);
 291                 break;
 292         case FORMATTYPE:
 293                 doformat(argv, argc);
 294                 break;
 295 #endif
 296         case CHNQTYPE:
 297                 dochq(argv, ac);
 298                 break;
 299
 300         case CHNCTYPE:
 301                 dochc(argv, argc);
 302                 break;
 303
 304         case SUBSTYPE:
 305         /*
 306          * dosub - select substring
 307          *
 308          */
 309                 if (argc > 3)
 310                         dosub(argv, argc);
 311                 break;
 312
 313         case SHIFTYPE:
 314         /*
 315          * doshift - push back all arguments
 316          * except the first one (i.e. skip
 317          * argv[2])
 318          */
 319                 if (argc > 3) {
 320                         for (n = argc - 1; n > 3; n--) {
 321                                 pbstr(rquote);
 322                                 pbstr(argv[n]);
 323                                 pbstr(lquote);
 324                                 pushback(COMMA);
 325                         }
 326                         pbstr(rquote);
 327                         pbstr(argv[3]);
 328                         pbstr(lquote);
 329                 }
 330                 break;
 331
 332         case DIVRTYPE:
 333                 if (argc > 2 && (n = atoi(argv[2])) != 0)
 334                         dodiv(n);
 335                 else {
 336                         active = stdout;
 337                         oindex = 0;
 338                 }
 339                 break;
 340
 341         case UNDVTYPE:
 342                 doundiv(argv, argc);
 343                 break;
 344
 345         case DIVNTYPE:
 346         /*
 347          * dodivnum - return the number of
 348          * current output diversion
 349          */
 350                 pbnum(oindex);
 351                 break;
 352
 353         case UNDFTYPE:
 354         /*
 355          * doundefine - undefine a previously
 356          * defined macro(s) or m4 keyword(s).
 357          */
 358                 if (argc > 2)
 359                         for (n = 2; n < argc; n++)
 360                                 macro_undefine(argv[n]);
 361                 break;
 362
 363         case POPDTYPE:
 364         /*
 365          * dopopdef - remove the topmost
 366          * definitions of macro(s) or m4
 367          * keyword(s).
 368          */
 369                 if (argc > 2)
 370                         for (n = 2; n < argc; n++)
 371                                 macro_popdef(argv[n]);
 372                 break;
 373
 374         case MKTMTYPE:
 375         /*
 376          * dotemp - create a temporary file
 377          */
 378                 if (argc > 2) {
 379                         int fd;
 380                         char *temp;
 381
 382                         temp = xstrdup(argv[2]);
 383
 384                         fd = mkstemp(temp);
 385                         if (fd == -1)
 386                                 err(1,
 387             "%s at line %lu: couldn't make temp file %s",
 388             CURRENT_NAME, CURRENT_LINE, argv[2]);
 389                         close(fd);
 390                         pbstr(temp);
 391                         free(temp);
 392                 }
 393                 break;
 394
 395         case TRNLTYPE:
 396         /*
 397          * dotranslit - replace all characters in
 398          * the source string that appears in the
 399          * "from" string with the corresponding
 400          * characters in the "to" string.
 401          */
 402                 if (argc > 3) {
 403                         char *temp;
 404
 405                         temp = xalloc(strlen(argv[2])+1, NULL);
 406                         if (argc > 4)
 407                                 map(temp, argv[2], argv[3], argv[4]);
 408                         else
 409                                 map(temp, argv[2], argv[3], null);
 410                         pbstr(temp);
 411                         free(temp);
 412                 } else if (argc > 2)
 413                         pbstr(argv[2]);
 414                 break;
 415
 416         case INDXTYPE:
 417         /*
 418          * doindex - find the index of the second
 419          * argument string in the first argument
 420          * string. -1 if not present.
 421          */
 422                 pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
 423                 break;
 424
 425         case ERRPTYPE:
 426         /*
 427          * doerrp - print the arguments to stderr
 428          * file
 429          */
 430                 if (argc > 2) {
 431                         for (n = 2; n < argc; n++)
 432                                 fprintf(stderr, "%s ", argv[n]);
 433                         fprintf(stderr, "\n");
 434                 }
 435                 break;
 436
 437         case DNLNTYPE:
 438         /*
 439          * dodnl - eat-up-to and including
 440          * newline
 441          */
 442                 while ((c = gpbc()) != '\n' && c != EOF)
 443                         ;
 444                 break;
 445
 446         case M4WRTYPE:
 447         /*
 448          * dom4wrap - set up for
 449          * wrap-up/wind-down activity
 450          */
 451                 if (argc > 2)
 452                         dom4wrap(argv[2]);
 453                 break;
 454
 455         case EXITTYPE:
 456         /*
 457          * doexit - immediate exit from m4.
 458          */
 459                 killdiv();
 460                 exit((argc > 2) ? atoi(argv[2]) : 0);
 461                 break;
 462
 463         case DEFNTYPE:
 464                 if (argc > 2)
 465                         for (n = 2; n < argc; n++)
 466                                 dodefn(argv[n]);
 467                 break;
 468
 469         case INDIRTYPE: /* Indirect call */
 470                 if (argc > 2)
 471                         doindir(argv, argc);
 472                 break;
 473
 474         case BUILTINTYPE: /* Builtins only */
 475                 if (argc > 2)
 476                         dobuiltin(argv, argc);
 477                 break;
 478
 479         case PATSTYPE:
 480                 if (argc > 2)
 481                         dopatsubst(argv, argc);
 482                 break;
 483         case REGEXPTYPE:
 484                 if (argc > 2)
 485                         doregexp(argv, argc);
 486                 break;
 487         case LINETYPE:
 488                 doprintlineno(infile+ilevel);
 489                 break;
 490         case FILENAMETYPE:
 491                 doprintfilename(infile+ilevel);
 492                 break;
 493         case SELFTYPE:
 494                 pbstr(rquote);
 495                 pbstr(argv[1]);
 496                 pbstr(lquote);
 497                 break;
 498         default:
 499                 m4errx(1, "eval: major botch.");
 500                 break;
 501         }
 502 }
 503
 504 /*
 505  * expand_macro - user-defined macro expansion
 506  */
 507 void
 508 expand_macro(const char *argv[], int argc)
 509 {
 510         const char *t;
 511         const char *p;
 512         int n;
 513         int argno;
 514
 515         t = argv[0];                   /* defn string as a whole */
 516         p = t;
 517         while (*p)
 518                 p++;
 519         p--;                           /* last character of defn */
 520         while (p > t) {
 521                 if (*(p - 1) != ARGFLAG)
 522                         PUSHBACK(*p);
 523                 else {
 524                         switch (*p) {
 525
 526                         case '#':
 527                                 pbnum(argc - 2);
 528                                 break;
 529                         case '0':
 530                         case '1':
 531                         case '2':
 532                         case '3':
 533                         case '4':
 534                         case '5':
 535                         case '6':
 536                         case '7':
 537                         case '8':
 538                         case '9':
 539                                 if ((argno = *p - '0') < argc - 1)
 540                                         pbstr(argv[argno + 1]);
 541                                 break;
 542                         case '*':
 543                                 if (argc > 2) {
 544                                         for (n = argc - 1; n > 2; n--) {
 545                                                 pbstr(argv[n]);
 546                                                 pushback(COMMA);
 547                                         }
 548                                         pbstr(argv[2]);
 549                                 }
 550                                 break;
 551                         case '@':
 552                                 if (argc > 2) {
 553                                         for (n = argc - 1; n > 2; n--) {
 554                                                 pbstr(rquote);
 555                                                 pbstr(argv[n]);
 556                                                 pbstr(lquote);
 557                                                 pushback(COMMA);
 558                                         }
 559                                         pbstr(rquote);
 560                                         pbstr(argv[2]);
 561                                         pbstr(lquote);
 562                                 }
 563                                 break;
 564                         default:
 565                                 PUSHBACK(*p);
 566                                 PUSHBACK('$');
 567                                 break;
 568                         }
 569                         p--;
 570                 }
 571                 p--;
 572         }
 573         if (p == t)                    /* do last character */
 574                 PUSHBACK(*p);
 575 }
 576
 577
 578 /*
 579  * dodefine - install definition in the table
 580  */
 581 void
 582 dodefine(const char *name, const char *defn)
 583 {
 584         if (!*name && !mimic_gnu)
 585                 m4errx(1, "null definition.");
 586         else
 587                 macro_define(name, defn);
 588 }
 589
 590 /*
 591  * dodefn - push back a quoted definition of
 592  *      the given name.
 593  */
 594 static void
 595 dodefn(const char *name)
 596 {
 597         struct macro_definition *p;
 598
 599         if ((p = lookup_macro_definition(name)) != NULL) {
 600                 if ((p->type & TYPEMASK) == MACRTYPE) {
 601                         pbstr(rquote);
 602                         pbstr(p->defn);
 603                         pbstr(lquote);
 604                 } else {
 605                         pbstr(p->defn);
 606                         pbstr(BUILTIN_MARKER);
 607                 }
 608         }
 609 }
 610
 611 /*
 612  * dopushdef - install a definition in the hash table
 613  *      without removing a previous definition. Since
 614  *      each new entry is entered in *front* of the
 615  *      hash bucket, it hides a previous definition from
 616  *      lookup.
 617  */
 618 static void
 619 dopushdef(const char *name, const char *defn)
 620 {
 621         if (!*name && !mimic_gnu)
 622                 m4errx(1, "null definition.");
 623         else
 624                 macro_pushdef(name, defn);
 625 }
 626
 627 /*
 628  * dump_one_def - dump the specified definition.
 629  */
 630 static void
 631 dump_one_def(const char *name, struct macro_definition *p)
 632 {
 633         if (!traceout)
 634                 traceout = stderr;
 635         if (mimic_gnu) {
 636                 if ((p->type & TYPEMASK) == MACRTYPE)
 637                         fprintf(traceout, "%s:\t%s\n", name, p->defn);
 638                 else {
 639                         fprintf(traceout, "%s:\t<%s>\n", name, p->defn);
 640                 }
 641         } else
 642                 fprintf(traceout, "`%s'\t`%s'\n", name, p->defn);
 643 }
 644
 645 /*
 646  * dodumpdef - dump the specified definitions in the hash
 647  *      table to stderr. If nothing is specified, the entire
 648  *      hash table is dumped.
 649  */
 650 static void
 651 dodump(const char *argv[], int argc)
 652 {
 653         int n;
 654         struct macro_definition *p;
 655
 656         if (argc > 2) {
 657                 for (n = 2; n < argc; n++)
 658                         if ((p = lookup_macro_definition(argv[n])) != NULL)
 659                                 dump_one_def(argv[n], p);
 660         } else
 661                 macro_for_all(dump_one_def);
 662 }
 663
 664 /*
 665  * dotrace - mark some macros as traced/untraced depending upon on.
 666  */
 667 static void
 668 dotrace(const char *argv[], int argc, int on)
 669 {
 670         int n;
 671
 672         if (argc > 2) {
 673                 for (n = 2; n < argc; n++)
 674                         mark_traced(argv[n], on);
 675         } else
 676                 mark_traced(NULL, on);
 677 }
 678
 679 /*
 680  * doifelse - select one of two alternatives - loop.
 681  */
 682 static void
 683 doifelse(const char *argv[], int argc)
 684 {
 685         cycle {
 686                 if (STREQ(argv[2], argv[3]))
 687                         pbstr(argv[4]);
 688                 else if (argc == 6)
 689                         pbstr(argv[5]);
 690                 else if (argc > 6) {
 691                         argv += 3;
 692                         argc -= 3;
 693                         continue;
 694                 }
 695                 break;
 696         }
 697 }
 698
 699 /*
 700  * doinclude - include a given file.
 701  */
 702 static int
 703 doincl(const char *ifile)
 704 {
 705         if (ilevel + 1 == MAXINP)
 706                 m4errx(1, "too many include files.");
 707         if (fopen_trypath(infile+ilevel+1, ifile) != NULL) {
 708                 ilevel++;
 709                 bbase[ilevel] = bufbase = bp;
 710                 return (1);
 711         } else
 712                 return (0);
 713 }
 714
 715 #ifdef EXTENDED
 716 /*
 717  * dopaste - include a given file without any
 718  *           macro processing.
 719  */
 720 static int
 721 dopaste(const char *pfile)
 722 {
 723         FILE *pf;
 724         int c;
 725
 726         if ((pf = fopen(pfile, "r")) != NULL) {
 727                 if (synch_lines)
 728                     fprintf(active, "#line 1 \"%s\"\n", pfile);
 729                 while ((c = getc(pf)) != EOF)
 730                         putc(c, active);
 731                 (void) fclose(pf);
 732                 emit_synchline();
 733                 return (1);
 734         } else
 735                 return (0);
 736 }
 737 #endif
 738
 739 /*
 740  * dochq - change quote characters
 741  */
 742 static void
 743 dochq(const char *argv[], int ac)
 744 {
 745         if (ac == 2) {
 746                 lquote[0] = LQUOTE; lquote[1] = EOS;
 747                 rquote[0] = RQUOTE; rquote[1] = EOS;
 748         } else {
 749                 strlcpy(lquote, argv[2], sizeof(lquote));
 750                 if (ac > 3) {
 751                         strlcpy(rquote, argv[3], sizeof(rquote));
 752                 } else {
 753                         rquote[0] = ECOMMT; rquote[1] = EOS;
 754                 }
 755         }
 756 }
 757
 758 /*
 759  * dochc - change comment characters
 760  */
 761 static void
 762 dochc(const char *argv[], int argc)
 763 {
 764 /* XXX Note that there is no difference between no argument and a single
 765  * empty argument.
 766  */
 767         if (argc == 2) {
 768                 scommt[0] = EOS;
 769                 ecommt[0] = EOS;
 770         } else {
 771                 strlcpy(scommt, argv[2], sizeof(scommt));
 772                 if (argc == 3) {
 773                         ecommt[0] = ECOMMT; ecommt[1] = EOS;
 774                 } else {
 775                         strlcpy(ecommt, argv[3], sizeof(ecommt));
 776                 }
 777         }
 778 }
 779
 780 /*
 781  * dom4wrap - expand text at EOF
 782  */
 783 static void
 784 dom4wrap(const char *text)
 785 {
 786         if (wrapindex >= maxwraps) {
 787                 if (maxwraps == 0)
 788                         maxwraps = 16;
 789                 else
 790                         maxwraps *= 2;
 791                 m4wraps = xrealloc(m4wraps, maxwraps * sizeof(*m4wraps),
 792                    "too many m4wraps");
 793         }
 794         m4wraps[wrapindex++] = xstrdup(text);
 795 }
 796
 797 /*
 798  * dodivert - divert the output to a temporary file
 799  */
 800 static void
 801 dodiv(int n)
 802 {
 803         int fd;
 804
 805         oindex = n;
 806         if (n >= maxout) {
 807                 if (mimic_gnu)
 808                         resizedivs(n + 10);
 809                 else
 810                         n = 0;          /* bitbucket */
 811         }
 812
 813         if (n < 0)
 814                 n = 0;                 /* bitbucket */
 815         if (outfile[n] == NULL) {
 816                 char fname[] = _PATH_DIVNAME;
 817
 818                 if ((fd = mkstemp(fname)) < 0 ||
 819                         (outfile[n] = fdopen(fd, "w+")) == NULL)
 820                                 err(1, "%s: cannot divert", fname);
 821                 if (unlink(fname) == -1)
 822                         err(1, "%s: cannot unlink", fname);
 823         }
 824         active = outfile[n];
 825 }
 826
 827 /*
 828  * doundivert - undivert a specified output, or all
 829  *              other outputs, in numerical order.
 830  */
 831 static void
 832 doundiv(const char *argv[], int argc)
 833 {
 834         int ind;
 835         int n;
 836
 837         if (argc > 2) {
 838                 for (ind = 2; ind < argc; ind++) {
 839                         const char *errstr;
 840                         n = strtonum(argv[ind], 1, INT_MAX, &errstr);
 841                         if (errstr) {
 842                                 if (errno == EINVAL && mimic_gnu)
 843                                         getdivfile(argv[ind]);
 844                         } else {
 845                                 if (n < maxout && outfile[n] != NULL)
 846                                         getdiv(n);
 847                         }
 848                 }
 849         }
 850         else
 851                 for (n = 1; n < maxout; n++)
 852                         if (outfile[n] != NULL)
 853                                 getdiv(n);
 854 }
 855
 856 /*
 857  * dosub - select substring
 858  */
 859 static void
 860 dosub(const char *argv[], int argc)
 861 {
 862         const char *ap, *fc, *k;
 863         int nc;
 864
 865         ap = argv[2];                  /* target string */
 866 #ifdef EXPR
 867         fc = ap + expr(argv[3]);       /* first char */
 868 #else
 869         fc = ap + atoi(argv[3]);       /* first char */
 870 #endif
 871         nc = strlen(fc);
 872         if (argc >= 5)
 873 #ifdef EXPR
 874                 nc = min(nc, expr(argv[4]));
 875 #else
 876                 nc = min(nc, atoi(argv[4]));
 877 #endif
 878         if (fc >= ap && fc < ap + strlen(ap))
 879                 for (k = fc + nc - 1; k >= fc; k--)
 880                         pushback(*k);
 881 }
 882
 883 /*
 884  * map:
 885  * map every character of s1 that is specified in from
 886  * into s3 and replace in s. (source s1 remains untouched)
 887  *
 888  * This is a standard implementation of map(s,from,to) function of ICON
 889  * language. Within mapvec, we replace every character of "from" with
 890  * the corresponding character in "to". If "to" is shorter than "from",
 891  * than the corresponding entries are null, which means that those
 892  * characters dissapear altogether. Furthermore, imagine
 893  * map(dest, "sourcestring", "srtin", "rn..*") type call. In this case,
 894  * `s' maps to `r', `r' maps to `n' and `n' maps to `*'. Thus, `s'
 895  * ultimately maps to `*'. In order to achieve this effect in an efficient
 896  * manner (i.e. without multiple passes over the destination string), we
 897  * loop over mapvec, starting with the initial source character. if the
 898  * character value (dch) in this location is different than the source
 899  * character (sch), sch becomes dch, once again to index into mapvec, until
 900  * the character value stabilizes (i.e. sch = dch, in other words
 901  * mapvec[n] == n). Even if the entry in the mapvec is null for an ordinary
 902  * character, it will stabilize, since mapvec[0] == 0 at all times. At the
 903  * end, we restore mapvec* back to normal where mapvec[n] == n for
 904  * 0 <= n <= 127. This strategy, along with the restoration of mapvec, is
 905  * about 5 times faster than any algorithm that makes multiple passes over
 906  * destination string.
 907  */
 908 static void
 909 map(char *dest, const char *src, const char *from, const char *to)
 910 {
 911         const char *tmp;
 912         unsigned char sch, dch;
 913         static char frombis[257];
 914         static char tobis[257];
 915         static unsigned char mapvec[256] = {
 916             0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
 917             19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
 918             36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
 919             53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69,
 920             70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86,
 921             87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102,
 922             103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
 923             116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
 924             129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141,
 925             142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154,
 926             155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167,
 927             168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180,
 928             181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193,
 929             194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206,
 930             207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,
 931             220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232,
 932             233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,
 933             246, 247, 248, 249, 250, 251, 252, 253, 254, 255
 934         };
 935
 936         if (*src) {
 937                 if (mimic_gnu) {
 938                         /*
 939                          * expand character ranges on the fly
 940                          */
 941                         from = handledash(frombis, frombis + 256, from);
 942                         to = handledash(tobis, tobis + 256, to);
 943                 }
 944                 tmp = from;
 945         /*
 946          * create a mapping between "from" and
 947          * "to"
 948          */
 949                 while (*from)
 950                         mapvec[(unsigned char)(*from++)] = (*to) ?
 951                                 (unsigned char)(*to++) : 0;
 952
 953                 while (*src) {
 954                         sch = (unsigned char)(*src++);
 955                         dch = mapvec[sch];
 956                         while (dch != sch) {
 957                                 sch = dch;
 958                                 dch = mapvec[sch];
 959                         }
 960                         if ((*dest = (char)dch))
 961                                 dest++;
 962                 }
 963         /*
 964          * restore all the changed characters
 965          */
 966                 while (*tmp) {
 967                         mapvec[(unsigned char)(*tmp)] = (unsigned char)(*tmp);
 968                         tmp++;
 969                 }
 970         }
 971         *dest = '\0';
 972 }
 973
 974
 975 /*
 976  * handledash:
 977  *  use buffer to copy the src string, expanding character ranges
 978  * on the way.
 979  */
 980 static const char *
 981 handledash(char *buffer, char *end, const char *src)
 982 {
 983         char *p;
 984
 985         p = buffer;
 986         while(*src) {
 987                 if (src[1] == '-' && src[2]) {
 988                         unsigned char i;
 989                         if ((unsigned char)src[0] <= (unsigned char)src[2]) {
 990                                 for (i = (unsigned char)src[0];
 991                                     i <= (unsigned char)src[2]; i++) {
 992                                         *p++ = i;
 993                                         if (p == end) {
 994                                                 *p = '\0';
 995                                                 return buffer;
 996                                         }
 997                                 }
 998                         } else {
 999                                 for (i = (unsigned char)src[0];
1000                                     i >= (unsigned char)src[2]; i--) {
1001                                         *p++ = i;
1002                                         if (p == end) {
1003                                                 *p = '\0';
1004                                                 return buffer;
1005                                         }
1006                                 }
1007                         }
1008                         src += 3;
1009                 } else
1010                         *p++ = *src++;
1011                 if (p == end)
1012                         break;
1013         }
1014         *p = '\0';
1015         return buffer;
1016 }