mdoc.c

   1 /*      $Id: mdoc.c,v 1.79 2009/06/15 10:02:53 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #include <assert.h>
  18 #include <ctype.h>
  19 #include <stdarg.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #include "libmdoc.h"
  25
  26 enum    merr {
  27         ENOCALL,
  28         EBODYPROL,
  29         EPROLBODY,
  30         ESPACE,
  31         ETEXTPROL,
  32         ENOBLANK,
  33         EMALLOC
  34 };
  35
  36 const   char *const __mdoc_macronames[MDOC_MAX] = {
  37         "\\\"",         "Dd",           "Dt",           "Os",
  38         "Sh",           "Ss",           "Pp",           "D1",
  39         "Dl",           "Bd",           "Ed",           "Bl",
  40         "El",           "It",           "Ad",           "An",
  41         "Ar",           "Cd",           "Cm",           "Dv",
  42         "Er",           "Ev",           "Ex",           "Fa",
  43         "Fd",           "Fl",           "Fn",           "Ft",
  44         "Ic",           "In",           "Li",           "Nd",
  45         "Nm",           "Op",           "Ot",           "Pa",
  46         "Rv",           "St",           "Va",           "Vt",
  47         /* LINTED */
  48         "Xr",           "\%A",          "\%B",          "\%D",
  49         /* LINTED */
  50         "\%I",          "\%J",          "\%N",          "\%O",
  51         /* LINTED */
  52         "\%P",          "\%R",          "\%T",          "\%V",
  53         "Ac",           "Ao",           "Aq",           "At",
  54         "Bc",           "Bf",           "Bo",           "Bq",
  55         "Bsx",          "Bx",           "Db",           "Dc",
  56         "Do",           "Dq",           "Ec",           "Ef",
  57         "Em",           "Eo",           "Fx",           "Ms",
  58         "No",           "Ns",           "Nx",           "Ox",
  59         "Pc",           "Pf",           "Po",           "Pq",
  60         "Qc",           "Ql",           "Qo",           "Qq",
  61         "Re",           "Rs",           "Sc",           "So",
  62         "Sq",           "Sm",           "Sx",           "Sy",
  63         "Tn",           "Ux",           "Xc",           "Xo",
  64         "Fo",           "Fc",           "Oo",           "Oc",
  65         "Bk",           "Ek",           "Bt",           "Hf",
  66         "Fr",           "Ud",           "Lb",           "Ap",
  67         "Lp",           "Lk",           "Mt",           "Brq",
  68         /* LINTED */
  69         "Bro",          "Brc",          "\%C",          "Es",
  70         /* LINTED */
  71         "En",           "Dx",           "\%Q"
  72         };
  73
  74 const   char *const __mdoc_argnames[MDOC_ARG_MAX] = {
  75         "split",                "nosplit",              "ragged",
  76         "unfilled",             "literal",              "file",
  77         "offset",               "bullet",               "dash",
  78         "hyphen",               "item",                 "enum",
  79         "tag",                  "diag",                 "hang",
  80         "ohang",                "inset",                "column",
  81         "width",                "compact",              "std",
  82         "filled",               "words",                "emphasis",
  83         "symbolic",             "nested"
  84         };
  85
  86 const   char * const *mdoc_macronames = __mdoc_macronames;
  87 const   char * const *mdoc_argnames = __mdoc_argnames;
  88
  89 static  void              mdoc_free1(struct mdoc *);
  90 static  int               mdoc_alloc1(struct mdoc *);
  91 static  struct mdoc_node *node_alloc(struct mdoc *, int, int,
  92                                 int, enum mdoc_type);
  93 static  int               node_append(struct mdoc *,
  94                                 struct mdoc_node *);
  95 static  int               parsetext(struct mdoc *, int, char *);
  96 static  int               parsemacro(struct mdoc *, int, char *);
  97 static  int               macrowarn(struct mdoc *, int, const char *);
  98 static  int               perr(struct mdoc *, int, int, enum merr);
  99
 100 #define verr(m, t) perr((m), (m)->last->line, (m)->last->pos, (t))
 101
 102 /*
 103  * Get the first (root) node of the parse tree.
 104  */
 105 const struct mdoc_node *
 106 mdoc_node(const struct mdoc *m)
 107 {
 108
 109         return(MDOC_HALT & m->flags ? NULL : m->first);
 110 }
 111
 112
 113 const struct mdoc_meta *
 114 mdoc_meta(const struct mdoc *m)
 115 {
 116
 117         return(MDOC_HALT & m->flags ? NULL : &m->meta);
 118 }
 119
 120
 121 static void
 122 mdoc_free1(struct mdoc *mdoc)
 123 {
 124
 125         if (mdoc->first)
 126                 mdoc_node_freelist(mdoc->first);
 127         if (mdoc->meta.title)
 128                 free(mdoc->meta.title);
 129         if (mdoc->meta.os)
 130                 free(mdoc->meta.os);
 131         if (mdoc->meta.name)
 132                 free(mdoc->meta.name);
 133         if (mdoc->meta.arch)
 134                 free(mdoc->meta.arch);
 135         if (mdoc->meta.vol)
 136                 free(mdoc->meta.vol);
 137 }
 138
 139
 140 static int
 141 mdoc_alloc1(struct mdoc *mdoc)
 142 {
 143
 144         bzero(&mdoc->meta, sizeof(struct mdoc_meta));
 145         mdoc->flags = 0;
 146         mdoc->lastnamed = mdoc->lastsec = 0;
 147         mdoc->last = calloc(1, sizeof(struct mdoc_node));
 148         if (NULL == mdoc->last)
 149                 return(0);
 150
 151         mdoc->first = mdoc->last;
 152         mdoc->last->type = MDOC_ROOT;
 153         mdoc->next = MDOC_NEXT_CHILD;
 154         return(1);
 155 }
 156
 157
 158 /*
 159  * Free up all resources contributed by a parse:  the node tree,
 160  * meta-data and so on.  Then reallocate the root node for another
 161  * parse.
 162  */
 163 int
 164 mdoc_reset(struct mdoc *mdoc)
 165 {
 166
 167         mdoc_free1(mdoc);
 168         return(mdoc_alloc1(mdoc));
 169 }
 170
 171
 172 /*
 173  * Completely free up all resources.
 174  */
 175 void
 176 mdoc_free(struct mdoc *mdoc)
 177 {
 178
 179         mdoc_free1(mdoc);
 180         if (mdoc->htab)
 181                 mdoc_hash_free(mdoc->htab);
 182         free(mdoc);
 183 }
 184
 185
 186 struct mdoc *
 187 mdoc_alloc(void *data, int pflags, const struct mdoc_cb *cb)
 188 {
 189         struct mdoc     *p;
 190
 191         if (NULL == (p = calloc(1, sizeof(struct mdoc))))
 192                 return(NULL);
 193         if (cb)
 194                 (void)memcpy(&p->cb, cb, sizeof(struct mdoc_cb));
 195
 196         p->data = data;
 197         p->pflags = pflags;
 198
 199         if (NULL == (p->htab = mdoc_hash_alloc())) {
 200                 free(p);
 201                 return(NULL);
 202         } else if (mdoc_alloc1(p))
 203                 return(p);
 204
 205         free(p);
 206         return(NULL);
 207 }
 208
 209
 210 /*
 211  * Climb back up the parse tree, validating open scopes.  Mostly calls
 212  * through to macro_end in macro.c.
 213  */
 214 int
 215 mdoc_endparse(struct mdoc *m)
 216 {
 217
 218         if (MDOC_HALT & m->flags)
 219                 return(0);
 220         else if (mdoc_macroend(m))
 221                 return(1);
 222         m->flags |= MDOC_HALT;
 223         return(0);
 224 }
 225
 226
 227 /*
 228  * Main parse routine.  Parses a single line -- really just hands off to
 229  * the macro or text parser.
 230  */
 231 int
 232 mdoc_parseln(struct mdoc *m, int ln, char *buf)
 233 {
 234
 235         /* If in error-mode, then we parse no more. */
 236
 237         if (MDOC_HALT & m->flags)
 238                 return(0);
 239
 240         return('.' == *buf ? parsemacro(m, ln, buf) :
 241                         parsetext(m, ln, buf));
 242 }
 243
 244
 245 void
 246 mdoc_vmsg(struct mdoc *mdoc, int ln, int pos, const char *fmt, ...)
 247 {
 248         char              buf[256];
 249         va_list           ap;
 250
 251         if (NULL == mdoc->cb.mdoc_msg)
 252                 return;
 253
 254         va_start(ap, fmt);
 255         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 256         va_end(ap);
 257         (*mdoc->cb.mdoc_msg)(mdoc->data, ln, pos, buf);
 258 }
 259
 260
 261 int
 262 mdoc_verr(struct mdoc *mdoc, int ln, int pos,
 263                 const char *fmt, ...)
 264 {
 265         char             buf[256];
 266         va_list          ap;
 267
 268         if (NULL == mdoc->cb.mdoc_err)
 269                 return(0);
 270
 271         va_start(ap, fmt);
 272         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 273         va_end(ap);
 274         return((*mdoc->cb.mdoc_err)(mdoc->data, ln, pos, buf));
 275 }
 276
 277
 278 int
 279 mdoc_vwarn(struct mdoc *mdoc, int ln, int pos,
 280                 enum mdoc_warn type, const char *fmt, ...)
 281 {
 282         char             buf[256];
 283         va_list          ap;
 284
 285         if (NULL == mdoc->cb.mdoc_warn)
 286                 return(0);
 287
 288         va_start(ap, fmt);
 289         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 290         va_end(ap);
 291         return((*mdoc->cb.mdoc_warn)(mdoc->data, ln, pos, type, buf));
 292 }
 293
 294
 295 int
 296 mdoc_nerr(struct mdoc *mdoc, const struct mdoc_node *node, const char *fmt, ...)
 297 {
 298         char             buf[256];
 299         va_list          ap;
 300
 301         if (NULL == mdoc->cb.mdoc_err)
 302                 return(0);
 303
 304         va_start(ap, fmt);
 305         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 306         va_end(ap);
 307         return((*mdoc->cb.mdoc_err)(mdoc->data, node->line, node->pos, buf));
 308 }
 309
 310
 311 int
 312 mdoc_warn(struct mdoc *mdoc, enum mdoc_warn type, const char *fmt, ...)
 313 {
 314         char             buf[256];
 315         va_list          ap;
 316
 317         if (NULL == mdoc->cb.mdoc_warn)
 318                 return(0);
 319
 320         va_start(ap, fmt);
 321         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 322         va_end(ap);
 323         return((*mdoc->cb.mdoc_warn)(mdoc->data, mdoc->last->line,
 324             mdoc->last->pos, type, buf));
 325 }
 326
 327
 328 int
 329 mdoc_err(struct mdoc *mdoc, const char *fmt, ...)
 330 {
 331         char             buf[256];
 332         va_list          ap;
 333
 334         if (NULL == mdoc->cb.mdoc_err)
 335                 return(0);
 336
 337         va_start(ap, fmt);
 338         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 339         va_end(ap);
 340         return((*mdoc->cb.mdoc_err)(mdoc->data, mdoc->last->line,
 341             mdoc->last->pos, buf));
 342 }
 343
 344
 345 void
 346 mdoc_msg(struct mdoc *mdoc, const char *fmt, ...)
 347 {
 348         char              buf[256];
 349         va_list           ap;
 350
 351         if (NULL == mdoc->cb.mdoc_msg)
 352                 return;
 353
 354         va_start(ap, fmt);
 355         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 356         va_end(ap);
 357         (*mdoc->cb.mdoc_msg)(mdoc->data, mdoc->last->line, mdoc->last->pos,
 358             buf);
 359 }
 360
 361
 362 void
 363 mdoc_pmsg(struct mdoc *mdoc, int line, int pos, const char *fmt, ...)
 364 {
 365         char              buf[256];
 366         va_list           ap;
 367
 368         if (NULL == mdoc->cb.mdoc_msg)
 369                 return;
 370
 371         va_start(ap, fmt);
 372         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 373         va_end(ap);
 374         (*mdoc->cb.mdoc_msg)(mdoc->data, line, pos, buf);
 375 }
 376
 377
 378 int
 379 mdoc_pwarn(struct mdoc *mdoc, int line, int pos, enum mdoc_warn type,
 380                 const char *fmt, ...)
 381 {
 382         char             buf[256];
 383         va_list          ap;
 384
 385         if (NULL == mdoc->cb.mdoc_warn)
 386                 return(0);
 387
 388         va_start(ap, fmt);
 389         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 390         va_end(ap);
 391         return((*mdoc->cb.mdoc_warn)(mdoc->data, line, pos, type, buf));
 392 }
 393
 394 int
 395 mdoc_perr(struct mdoc *mdoc, int line, int pos, const char *fmt, ...)
 396 {
 397         char             buf[256];
 398         va_list          ap;
 399
 400         if (NULL == mdoc->cb.mdoc_err)
 401                 return(0);
 402
 403         va_start(ap, fmt);
 404         (void)vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 405         va_end(ap);
 406         return((*mdoc->cb.mdoc_err)(mdoc->data, line, pos, buf));
 407 }
 408
 409
 410 int
 411 mdoc_macro(struct mdoc *m, int tok,
 412                 int ln, int pp, int *pos, char *buf)
 413 {
 414
 415         /* FIXME - these should happen during validation. */
 416
 417         if (MDOC_PROLOGUE & mdoc_macros[tok].flags &&
 418                         SEC_PROLOGUE != m->lastnamed)
 419                 return(perr(m, ln, pp, EPROLBODY));
 420
 421         if ( ! (MDOC_PROLOGUE & mdoc_macros[tok].flags) &&
 422                         SEC_PROLOGUE == m->lastnamed)
 423                 return(perr(m, ln, pp, EBODYPROL));
 424
 425         if (1 != pp && ! (MDOC_CALLABLE & mdoc_macros[tok].flags))
 426                 return(perr(m, ln, pp, ENOCALL));
 427
 428         return((*mdoc_macros[tok].fp)(m, tok, ln, pp, pos, buf));
 429 }
 430
 431
 432 static int
 433 perr(struct mdoc *m, int line, int pos, enum merr type)
 434 {
 435         char            *p;
 436
 437         p = NULL;
 438         switch (type) {
 439         case (ENOCALL):
 440                 p = "not callable";
 441                 break;
 442         case (EPROLBODY):
 443                 p = "macro disallowed in document body";
 444                 break;
 445         case (EBODYPROL):
 446                 p = "macro disallowed in document prologue";
 447                 break;
 448         case (EMALLOC):
 449                 p = "memory exhausted";
 450                 break;
 451         case (ETEXTPROL):
 452                 p = "text disallowed in document prologue";
 453                 break;
 454         case (ENOBLANK):
 455                 p = "blank lines disallowed in non-literal contexts";
 456                 break;
 457         case (ESPACE):
 458                 p = "whitespace disallowed after delimiter";
 459                 break;
 460         }
 461         assert(p);
 462         return(mdoc_perr(m, line, pos, p));
 463 }
 464
 465
 466 static int
 467 node_append(struct mdoc *mdoc, struct mdoc_node *p)
 468 {
 469
 470         assert(mdoc->last);
 471         assert(mdoc->first);
 472         assert(MDOC_ROOT != p->type);
 473
 474         switch (mdoc->next) {
 475         case (MDOC_NEXT_SIBLING):
 476                 mdoc->last->next = p;
 477                 p->prev = mdoc->last;
 478                 p->parent = mdoc->last->parent;
 479                 break;
 480         case (MDOC_NEXT_CHILD):
 481                 mdoc->last->child = p;
 482                 p->parent = mdoc->last;
 483                 break;
 484         default:
 485                 abort();
 486                 /* NOTREACHED */
 487         }
 488
 489         if ( ! mdoc_valid_pre(mdoc, p))
 490                 return(0);
 491         if ( ! mdoc_action_pre(mdoc, p))
 492                 return(0);
 493
 494         switch (p->type) {
 495         case (MDOC_HEAD):
 496                 assert(MDOC_BLOCK == p->parent->type);
 497                 p->parent->head = p;
 498                 break;
 499         case (MDOC_TAIL):
 500                 assert(MDOC_BLOCK == p->parent->type);
 501                 p->parent->tail = p;
 502                 break;
 503         case (MDOC_BODY):
 504                 assert(MDOC_BLOCK == p->parent->type);
 505                 p->parent->body = p;
 506                 break;
 507         default:
 508                 break;
 509         }
 510
 511         mdoc->last = p;
 512
 513         switch (p->type) {
 514         case (MDOC_TEXT):
 515                 if ( ! mdoc_valid_post(mdoc))
 516                         return(0);
 517                 if ( ! mdoc_action_post(mdoc))
 518                         return(0);
 519                 break;
 520         default:
 521                 break;
 522         }
 523
 524         return(1);
 525 }
 526
 527
 528 static struct mdoc_node *
 529 node_alloc(struct mdoc *mdoc, int line,
 530                 int pos, int tok, enum mdoc_type type)
 531 {
 532         struct mdoc_node *p;
 533
 534         if (NULL == (p = calloc(1, sizeof(struct mdoc_node)))) {
 535                 (void)verr(mdoc, EMALLOC);
 536                 return(NULL);
 537         }
 538
 539         p->sec = mdoc->lastsec;
 540         p->line = line;
 541         p->pos = pos;
 542         p->tok = tok;
 543         if (MDOC_TEXT != (p->type = type))
 544                 assert(p->tok >= 0);
 545
 546         return(p);
 547 }
 548
 549
 550 int
 551 mdoc_tail_alloc(struct mdoc *mdoc, int line, int pos, int tok)
 552 {
 553         struct mdoc_node *p;
 554
 555         p = node_alloc(mdoc, line, pos, tok, MDOC_TAIL);
 556         if (NULL == p)
 557                 return(0);
 558         return(node_append(mdoc, p));
 559 }
 560
 561
 562 int
 563 mdoc_head_alloc(struct mdoc *mdoc, int line, int pos, int tok)
 564 {
 565         struct mdoc_node *p;
 566
 567         assert(mdoc->first);
 568         assert(mdoc->last);
 569
 570         p = node_alloc(mdoc, line, pos, tok, MDOC_HEAD);
 571         if (NULL == p)
 572                 return(0);
 573         return(node_append(mdoc, p));
 574 }
 575
 576
 577 int
 578 mdoc_body_alloc(struct mdoc *mdoc, int line, int pos, int tok)
 579 {
 580         struct mdoc_node *p;
 581
 582         p = node_alloc(mdoc, line, pos, tok, MDOC_BODY);
 583         if (NULL == p)
 584                 return(0);
 585         return(node_append(mdoc, p));
 586 }
 587
 588
 589 int
 590 mdoc_block_alloc(struct mdoc *mdoc, int line, int pos,
 591                 int tok, struct mdoc_arg *args)
 592 {
 593         struct mdoc_node *p;
 594
 595         p = node_alloc(mdoc, line, pos, tok, MDOC_BLOCK);
 596         if (NULL == p)
 597                 return(0);
 598         p->args = args;
 599         if (p->args)
 600                 (args->refcnt)++;
 601         return(node_append(mdoc, p));
 602 }
 603
 604
 605 int
 606 mdoc_elem_alloc(struct mdoc *mdoc, int line, int pos,
 607                 int tok, struct mdoc_arg *args)
 608 {
 609         struct mdoc_node *p;
 610
 611         p = node_alloc(mdoc, line, pos, tok, MDOC_ELEM);
 612         if (NULL == p)
 613                 return(0);
 614         p->args = args;
 615         if (p->args)
 616                 (args->refcnt)++;
 617         return(node_append(mdoc, p));
 618 }
 619
 620
 621 int
 622 mdoc_word_alloc(struct mdoc *mdoc,
 623                 int line, int pos, const char *word)
 624 {
 625         struct mdoc_node *p;
 626
 627         p = node_alloc(mdoc, line, pos, -1, MDOC_TEXT);
 628         if (NULL == p)
 629                 return(0);
 630         if (NULL == (p->string = strdup(word))) {
 631                 (void)verr(mdoc, EMALLOC);
 632                 return(0);
 633         }
 634         return(node_append(mdoc, p));
 635 }
 636
 637
 638 void
 639 mdoc_node_free(struct mdoc_node *p)
 640 {
 641
 642         if (p->string)
 643                 free(p->string);
 644         if (p->args)
 645                 mdoc_argv_free(p->args);
 646         free(p);
 647 }
 648
 649
 650 void
 651 mdoc_node_freelist(struct mdoc_node *p)
 652 {
 653
 654         if (p->child)
 655                 mdoc_node_freelist(p->child);
 656         if (p->next)
 657                 mdoc_node_freelist(p->next);
 658
 659         mdoc_node_free(p);
 660 }
 661
 662
 663 /*
 664  * Parse free-form text, that is, a line that does not begin with the
 665  * control character.
 666  */
 667 static int
 668 parsetext(struct mdoc *m, int line, char *buf)
 669 {
 670
 671         if (SEC_PROLOGUE == m->lastnamed)
 672                 return(perr(m, line, 0, ETEXTPROL));
 673
 674         if (0 == buf[0] && ! (MDOC_LITERAL & m->flags))
 675                 return(perr(m, line, 0, ENOBLANK));
 676
 677         if ( ! mdoc_word_alloc(m, line, 0, buf))
 678                 return(0);
 679
 680         m->next = MDOC_NEXT_SIBLING;
 681         return(1);
 682 }
 683
 684
 685 static int
 686 macrowarn(struct mdoc *m, int ln, const char *buf)
 687 {
 688         if ( ! (MDOC_IGN_MACRO & m->pflags))
 689                 return(mdoc_perr(m, ln, 1,
 690                                 "unknown macro: %s%s",
 691                                 buf, strlen(buf) > 3 ? "..." : ""));
 692         return(mdoc_pwarn(m, ln, 1, WARN_SYNTAX,
 693                                 "unknown macro: %s%s",
 694                                 buf, strlen(buf) > 3 ? "..." : ""));
 695 }
 696
 697
 698
 699 /*
 700  * Parse a macro line, that is, a line beginning with the control
 701  * character.
 702  */
 703 int
 704 parsemacro(struct mdoc *m, int ln, char *buf)
 705 {
 706         int               i, c;
 707         char              mac[5];
 708
 709         /* Comments and empties are quickly ignored. */
 710
 711         if (0 == buf[1])
 712                 return(1);
 713
 714         if (' ' == buf[1]) {
 715                 i = 2;
 716                 while (buf[i] && ' ' == buf[i])
 717                         i++;
 718                 if (0 == buf[i])
 719                         return(1);
 720                 return(perr(m, ln, 1, ESPACE));
 721         }
 722
 723         if (buf[1] && '\\' == buf[1])
 724                 if (buf[2] && '\"' == buf[2])
 725                         return(1);
 726
 727         /* Copy the first word into a nil-terminated buffer. */
 728
 729         for (i = 1; i < 5; i++) {
 730                 if (0 == (mac[i - 1] = buf[i]))
 731                         break;
 732                 else if (' ' == buf[i])
 733                         break;
 734         }
 735
 736         mac[i - 1] = 0;
 737
 738         if (i == 5 || i <= 2) {
 739                 if ( ! macrowarn(m, ln, mac))
 740                         goto err;
 741                 return(1);
 742         }
 743
 744         if (MDOC_MAX == (c = mdoc_hash_find(m->htab, mac))) {
 745                 if ( ! macrowarn(m, ln, mac))
 746                         goto err;
 747                 return(1);
 748         }
 749
 750         /* The macro is sane.  Jump to the next word. */
 751
 752         while (buf[i] && ' ' == buf[i])
 753                 i++;
 754
 755         /* Begin recursive parse sequence. */
 756
 757         if ( ! mdoc_macro(m, c, ln, 1, &i, buf))
 758                 goto err;
 759
 760         return(1);
 761
 762 err:    /* Error out. */
 763
 764         m->flags |= MDOC_HALT;
 765         return(0);
 766 }