mdoc.c

   1 /*      $Id: mdoc.c,v 1.146 2010/06/12 11:58:22 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@bsd.lv>
   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 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <sys/types.h>
  22
  23 #include <assert.h>
  24 #include <ctype.h>
  25 #include <stdarg.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <time.h>
  30
  31 #include "mandoc.h"
  32 #include "libmdoc.h"
  33 #include "libmandoc.h"
  34
  35 const   char *const __mdoc_macronames[MDOC_MAX] = {
  36         "Ap",           "Dd",           "Dt",           "Os",
  37         "Sh",           "Ss",           "Pp",           "D1",
  38         "Dl",           "Bd",           "Ed",           "Bl",
  39         "El",           "It",           "Ad",           "An",
  40         "Ar",           "Cd",           "Cm",           "Dv",
  41         "Er",           "Ev",           "Ex",           "Fa",
  42         "Fd",           "Fl",           "Fn",           "Ft",
  43         "Ic",           "In",           "Li",           "Nd",
  44         "Nm",           "Op",           "Ot",           "Pa",
  45         "Rv",           "St",           "Va",           "Vt",
  46         /* LINTED */
  47         "Xr",           "%A",           "%B",           "%D",
  48         /* LINTED */
  49         "%I",           "%J",           "%N",           "%O",
  50         /* LINTED */
  51         "%P",           "%R",           "%T",           "%V",
  52         "Ac",           "Ao",           "Aq",           "At",
  53         "Bc",           "Bf",           "Bo",           "Bq",
  54         "Bsx",          "Bx",           "Db",           "Dc",
  55         "Do",           "Dq",           "Ec",           "Ef",
  56         "Em",           "Eo",           "Fx",           "Ms",
  57         "No",           "Ns",           "Nx",           "Ox",
  58         "Pc",           "Pf",           "Po",           "Pq",
  59         "Qc",           "Ql",           "Qo",           "Qq",
  60         "Re",           "Rs",           "Sc",           "So",
  61         "Sq",           "Sm",           "Sx",           "Sy",
  62         "Tn",           "Ux",           "Xc",           "Xo",
  63         "Fo",           "Fc",           "Oo",           "Oc",
  64         "Bk",           "Ek",           "Bt",           "Hf",
  65         "Fr",           "Ud",           "Lb",           "Lp",
  66         "Lk",           "Mt",           "Brq",          "Bro",
  67         /* LINTED */
  68         "Brc",          "%C",           "Es",           "En",
  69         /* LINTED */
  70         "Dx",           "%Q",           "br",           "sp",
  71         /* LINTED */
  72         "%U",           "Ta"
  73         };
  74
  75 const   char *const __mdoc_argnames[MDOC_ARG_MAX] = {
  76         "split",                "nosplit",              "ragged",
  77         "unfilled",             "literal",              "file",
  78         "offset",               "bullet",               "dash",
  79         "hyphen",               "item",                 "enum",
  80         "tag",                  "diag",                 "hang",
  81         "ohang",                "inset",                "column",
  82         "width",                "compact",              "std",
  83         "filled",               "words",                "emphasis",
  84         "symbolic",             "nested",               "centered"
  85         };
  86
  87 const   char * const *mdoc_macronames = __mdoc_macronames;
  88 const   char * const *mdoc_argnames = __mdoc_argnames;
  89
  90 static  void              mdoc_node_free(struct mdoc_node *);
  91 static  void              mdoc_node_unlink(struct mdoc *,
  92                                 struct mdoc_node *);
  93 static  void              mdoc_free1(struct mdoc *);
  94 static  void              mdoc_alloc1(struct mdoc *);
  95 static  struct mdoc_node *node_alloc(struct mdoc *, int, int,
  96                                 enum mdoct, enum mdoc_type);
  97 static  int               node_append(struct mdoc *,
  98                                 struct mdoc_node *);
  99 static  int               mdoc_ptext(struct mdoc *, int, char *, int);
 100 static  int               mdoc_pmacro(struct mdoc *, int, char *, int);
 101 static  int               macrowarn(struct mdoc *, int,
 102                                 const char *, int);
 103
 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 /*
 122  * Frees volatile resources (parse tree, meta-data, fields).
 123  */
 124 static void
 125 mdoc_free1(struct mdoc *mdoc)
 126 {
 127
 128         if (mdoc->first)
 129                 mdoc_node_delete(mdoc, mdoc->first);
 130         if (mdoc->meta.title)
 131                 free(mdoc->meta.title);
 132         if (mdoc->meta.os)
 133                 free(mdoc->meta.os);
 134         if (mdoc->meta.name)
 135                 free(mdoc->meta.name);
 136         if (mdoc->meta.arch)
 137                 free(mdoc->meta.arch);
 138         if (mdoc->meta.vol)
 139                 free(mdoc->meta.vol);
 140         if (mdoc->meta.msec)
 141                 free(mdoc->meta.msec);
 142 }
 143
 144
 145 /*
 146  * Allocate all volatile resources (parse tree, meta-data, fields).
 147  */
 148 static void
 149 mdoc_alloc1(struct mdoc *mdoc)
 150 {
 151
 152         memset(&mdoc->meta, 0, sizeof(struct mdoc_meta));
 153         mdoc->flags = 0;
 154         mdoc->lastnamed = mdoc->lastsec = SEC_NONE;
 155         mdoc->last = mandoc_calloc(1, sizeof(struct mdoc_node));
 156         mdoc->first = mdoc->last;
 157         mdoc->last->type = MDOC_ROOT;
 158         mdoc->next = MDOC_NEXT_CHILD;
 159 }
 160
 161
 162 /*
 163  * Free up volatile resources (see mdoc_free1()) then re-initialises the
 164  * data with mdoc_alloc1().  After invocation, parse data has been reset
 165  * and the parser is ready for re-invocation on a new tree; however,
 166  * cross-parse non-volatile data is kept intact.
 167  */
 168 void
 169 mdoc_reset(struct mdoc *mdoc)
 170 {
 171
 172         mdoc_free1(mdoc);
 173         mdoc_alloc1(mdoc);
 174 }
 175
 176
 177 /*
 178  * Completely free up all volatile and non-volatile parse resources.
 179  * After invocation, the pointer is no longer usable.
 180  */
 181 void
 182 mdoc_free(struct mdoc *mdoc)
 183 {
 184
 185         mdoc_free1(mdoc);
 186         free(mdoc);
 187 }
 188
 189
 190 /*
 191  * Allocate volatile and non-volatile parse resources.
 192  */
 193 struct mdoc *
 194 mdoc_alloc(void *data, int pflags, mandocmsg msg)
 195 {
 196         struct mdoc     *p;
 197
 198         p = mandoc_calloc(1, sizeof(struct mdoc));
 199
 200         p->msg = msg;
 201         p->data = data;
 202         p->pflags = pflags;
 203
 204         mdoc_hash_init();
 205         mdoc_alloc1(p);
 206         return(p);
 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 (mdoc_pmacro()) or text parser (mdoc_ptext()).
 230  */
 231 int
 232 mdoc_parseln(struct mdoc *m, int ln, char *buf, int offs)
 233 {
 234
 235         if (MDOC_HALT & m->flags)
 236                 return(0);
 237
 238         m->flags |= MDOC_NEWLINE;
 239         return(('.' == buf[offs] || '\'' == buf[offs]) ?
 240                         mdoc_pmacro(m, ln, buf, offs) :
 241                         mdoc_ptext(m, ln, buf, offs));
 242 }
 243
 244
 245 int
 246 mdoc_vmsg(struct mdoc *mdoc, enum mandocerr t,
 247                 int ln, int pos, const char *fmt, ...)
 248 {
 249         char             buf[256];
 250         va_list          ap;
 251
 252         va_start(ap, fmt);
 253         vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 254         va_end(ap);
 255
 256         return((*mdoc->msg)(t, mdoc->data, ln, pos, buf));
 257 }
 258
 259
 260 int
 261 mdoc_macro(struct mdoc *m, enum mdoct tok,
 262                 int ln, int pp, int *pos, char *buf)
 263 {
 264         assert(tok < MDOC_MAX);
 265
 266         /* If we're in the body, deny prologue calls. */
 267
 268         if (MDOC_PROLOGUE & mdoc_macros[tok].flags &&
 269                         MDOC_PBODY & m->flags)
 270                 return(mdoc_pmsg(m, ln, pp, MANDOCERR_BADBODY));
 271
 272         /* If we're in the prologue, deny "body" macros.  */
 273
 274         if ( ! (MDOC_PROLOGUE & mdoc_macros[tok].flags) &&
 275                         ! (MDOC_PBODY & m->flags)) {
 276                 if ( ! mdoc_pmsg(m, ln, pp, MANDOCERR_BADPROLOG))
 277                         return(0);
 278                 if (NULL == m->meta.title)
 279                         m->meta.title = mandoc_strdup("UNKNOWN");
 280                 if (NULL == m->meta.vol)
 281                         m->meta.vol = mandoc_strdup("LOCAL");
 282                 if (NULL == m->meta.os)
 283                         m->meta.os = mandoc_strdup("LOCAL");
 284                 if (0 == m->meta.date)
 285                         m->meta.date = time(NULL);
 286                 m->flags |= MDOC_PBODY;
 287         }
 288
 289         return((*mdoc_macros[tok].fp)(m, tok, ln, pp, pos, buf));
 290 }
 291
 292
 293 static int
 294 node_append(struct mdoc *mdoc, struct mdoc_node *p)
 295 {
 296
 297         assert(mdoc->last);
 298         assert(mdoc->first);
 299         assert(MDOC_ROOT != p->type);
 300
 301         switch (mdoc->next) {
 302         case (MDOC_NEXT_SIBLING):
 303                 mdoc->last->next = p;
 304                 p->prev = mdoc->last;
 305                 p->parent = mdoc->last->parent;
 306                 break;
 307         case (MDOC_NEXT_CHILD):
 308                 mdoc->last->child = p;
 309                 p->parent = mdoc->last;
 310                 break;
 311         default:
 312                 abort();
 313                 /* NOTREACHED */
 314         }
 315
 316         p->parent->nchild++;
 317
 318         if ( ! mdoc_valid_pre(mdoc, p))
 319                 return(0);
 320         if ( ! mdoc_action_pre(mdoc, p))
 321                 return(0);
 322
 323         switch (p->type) {
 324         case (MDOC_HEAD):
 325                 assert(MDOC_BLOCK == p->parent->type);
 326                 p->parent->head = p;
 327                 break;
 328         case (MDOC_TAIL):
 329                 assert(MDOC_BLOCK == p->parent->type);
 330                 p->parent->tail = p;
 331                 break;
 332         case (MDOC_BODY):
 333                 assert(MDOC_BLOCK == p->parent->type);
 334                 p->parent->body = p;
 335                 break;
 336         default:
 337                 break;
 338         }
 339
 340         mdoc->last = p;
 341
 342         switch (p->type) {
 343         case (MDOC_TEXT):
 344                 if ( ! mdoc_valid_post(mdoc))
 345                         return(0);
 346                 if ( ! mdoc_action_post(mdoc))
 347                         return(0);
 348                 break;
 349         default:
 350                 break;
 351         }
 352
 353         return(1);
 354 }
 355
 356
 357 static struct mdoc_node *
 358 node_alloc(struct mdoc *m, int line, int pos,
 359                 enum mdoct tok, enum mdoc_type type)
 360 {
 361         struct mdoc_node *p;
 362
 363         p = mandoc_calloc(1, sizeof(struct mdoc_node));
 364         p->sec = m->lastsec;
 365         p->line = line;
 366         p->pos = pos;
 367         p->tok = tok;
 368         p->type = type;
 369         if (MDOC_NEWLINE & m->flags)
 370                 p->flags |= MDOC_LINE;
 371         m->flags &= ~MDOC_NEWLINE;
 372         return(p);
 373 }
 374
 375
 376 int
 377 mdoc_tail_alloc(struct mdoc *m, int line, int pos, enum mdoct tok)
 378 {
 379         struct mdoc_node *p;
 380
 381         p = node_alloc(m, line, pos, tok, MDOC_TAIL);
 382         if ( ! node_append(m, p))
 383                 return(0);
 384         m->next = MDOC_NEXT_CHILD;
 385         return(1);
 386 }
 387
 388
 389 int
 390 mdoc_head_alloc(struct mdoc *m, int line, int pos, enum mdoct tok)
 391 {
 392         struct mdoc_node *p;
 393
 394         assert(m->first);
 395         assert(m->last);
 396
 397         p = node_alloc(m, line, pos, tok, MDOC_HEAD);
 398         if ( ! node_append(m, p))
 399                 return(0);
 400         m->next = MDOC_NEXT_CHILD;
 401         return(1);
 402 }
 403
 404
 405 int
 406 mdoc_body_alloc(struct mdoc *m, int line, int pos, enum mdoct tok)
 407 {
 408         struct mdoc_node *p;
 409
 410         p = node_alloc(m, line, pos, tok, MDOC_BODY);
 411         if ( ! node_append(m, p))
 412                 return(0);
 413         m->next = MDOC_NEXT_CHILD;
 414         return(1);
 415 }
 416
 417
 418 int
 419 mdoc_block_alloc(struct mdoc *m, int line, int pos,
 420                 enum mdoct tok, struct mdoc_arg *args)
 421 {
 422         struct mdoc_node *p;
 423
 424         p = node_alloc(m, line, pos, tok, MDOC_BLOCK);
 425         p->args = args;
 426         if (p->args)
 427                 (args->refcnt)++;
 428         if ( ! node_append(m, p))
 429                 return(0);
 430         m->next = MDOC_NEXT_CHILD;
 431         return(1);
 432 }
 433
 434
 435 int
 436 mdoc_elem_alloc(struct mdoc *m, int line, int pos,
 437                 enum mdoct tok, struct mdoc_arg *args)
 438 {
 439         struct mdoc_node *p;
 440
 441         p = node_alloc(m, line, pos, tok, MDOC_ELEM);
 442         p->args = args;
 443         if (p->args)
 444                 (args->refcnt)++;
 445         if ( ! node_append(m, p))
 446                 return(0);
 447         m->next = MDOC_NEXT_CHILD;
 448         return(1);
 449 }
 450
 451
 452 int
 453 mdoc_word_alloc(struct mdoc *m, int line, int pos, const char *p)
 454 {
 455         struct mdoc_node *n;
 456         size_t            sv, len;
 457
 458         len = strlen(p);
 459
 460         n = node_alloc(m, line, pos, MDOC_MAX, MDOC_TEXT);
 461         n->string = mandoc_malloc(len + 1);
 462         sv = strlcpy(n->string, p, len + 1);
 463
 464         /* Prohibit truncation. */
 465         assert(sv < len + 1);
 466
 467         if ( ! node_append(m, n))
 468                 return(0);
 469
 470         m->next = MDOC_NEXT_SIBLING;
 471         return(1);
 472 }
 473
 474
 475 void
 476 mdoc_node_free(struct mdoc_node *p)
 477 {
 478
 479         if (p->string)
 480                 free(p->string);
 481         if (p->args)
 482                 mdoc_argv_free(p->args);
 483         free(p);
 484 }
 485
 486
 487 static void
 488 mdoc_node_unlink(struct mdoc *m, struct mdoc_node *n)
 489 {
 490
 491         /* Adjust siblings. */
 492
 493         if (n->prev)
 494                 n->prev->next = n->next;
 495         if (n->next)
 496                 n->next->prev = n->prev;
 497
 498         /* Adjust parent. */
 499
 500         if (n->parent) {
 501                 n->parent->nchild--;
 502                 if (n->parent->child == n)
 503                         n->parent->child = n->prev ? n->prev : n->next;
 504         }
 505
 506         /* Adjust parse point, if applicable. */
 507
 508         if (m && m->last == n) {
 509                 if (n->prev) {
 510                         m->last = n->prev;
 511                         m->next = MDOC_NEXT_SIBLING;
 512                 } else {
 513                         m->last = n->parent;
 514                         m->next = MDOC_NEXT_CHILD;
 515                 }
 516         }
 517
 518         if (m && m->first == n)
 519                 m->first = NULL;
 520 }
 521
 522
 523 void
 524 mdoc_node_delete(struct mdoc *m, struct mdoc_node *p)
 525 {
 526
 527         while (p->child) {
 528                 assert(p->nchild);
 529                 mdoc_node_delete(m, p->child);
 530         }
 531         assert(0 == p->nchild);
 532
 533         mdoc_node_unlink(m, p);
 534         mdoc_node_free(p);
 535 }
 536
 537
 538 /*
 539  * Parse free-form text, that is, a line that does not begin with the
 540  * control character.
 541  */
 542 static int
 543 mdoc_ptext(struct mdoc *m, int line, char *buf, int offs)
 544 {
 545         char             *c, *ws, *end;
 546         struct mdoc_node *n;
 547
 548         /* Ignore bogus comments. */
 549
 550         if ('\\' == buf[offs] &&
 551                         '.' == buf[offs + 1] &&
 552                         '"' == buf[offs + 2])
 553                 return(mdoc_pmsg(m, line, offs, MANDOCERR_BADCOMMENT));
 554
 555         /* No text before an initial macro. */
 556
 557         if (SEC_NONE == m->lastnamed)
 558                 return(mdoc_pmsg(m, line, offs, MANDOCERR_NOTEXT));
 559
 560         assert(m->last);
 561         n = m->last;
 562
 563         /*
 564          * Divert directly to list processing if we're encountering a
 565          * columnar MDOC_BLOCK with or without a prior MDOC_BLOCK entry
 566          * (a MDOC_BODY means it's already open, in which case we should
 567          * process within its context in the normal way).
 568          */
 569
 570         if (MDOC_Bl == n->tok && MDOC_BODY == n->type &&
 571                         LIST_column == n->data.Bl.type) {
 572                 /* `Bl' is open without any children. */
 573                 m->flags |= MDOC_FREECOL;
 574                 return(mdoc_macro(m, MDOC_It, line, offs, &offs, buf));
 575         }
 576
 577         if (MDOC_It == n->tok && MDOC_BLOCK == n->type &&
 578                         NULL != n->parent &&
 579                         MDOC_Bl == n->parent->tok &&
 580                         LIST_column == n->parent->data.Bl.type) {
 581                 /* `Bl' has block-level `It' children. */
 582                 m->flags |= MDOC_FREECOL;
 583                 return(mdoc_macro(m, MDOC_It, line, offs, &offs, buf));
 584         }
 585
 586         /*
 587          * Search for the beginning of unescaped trailing whitespace (ws)
 588          * and for the first character not to be output (end).
 589          */
 590
 591         /* FIXME: replace with strcspn(). */
 592         ws = NULL;
 593         for (c = end = buf + offs; *c; c++) {
 594                 switch (*c) {
 595                 case '-':
 596                         if (mandoc_hyph(buf + offs, c))
 597                                 *c = ASCII_HYPH;
 598                         ws = NULL;
 599                         break;
 600                 case ' ':
 601                         if (NULL == ws)
 602                                 ws = c;
 603                         continue;
 604                 case '\t':
 605                         /*
 606                          * Always warn about trailing tabs,
 607                          * even outside literal context,
 608                          * where they should be put on the next line.
 609                          */
 610                         if (NULL == ws)
 611                                 ws = c;
 612                         /*
 613                          * Strip trailing tabs in literal context only;
 614                          * outside, they affect the next line.
 615                          */
 616                         if (MDOC_LITERAL & m->flags)
 617                                 continue;
 618                         break;
 619                 case '\\':
 620                         /* Skip the escaped character, too, if any. */
 621                         if (c[1])
 622                                 c++;
 623                         /* FALLTHROUGH */
 624                 default:
 625                         ws = NULL;
 626                         break;
 627                 }
 628                 end = c + 1;
 629         }
 630         *end = '\0';
 631
 632         if (ws)
 633                 if ( ! mdoc_pmsg(m, line, (int)(ws-buf), MANDOCERR_EOLNSPACE))
 634                         return(0);
 635
 636         if ('\0' == buf[offs] && ! (MDOC_LITERAL & m->flags)) {
 637                 if ( ! mdoc_pmsg(m, line, (int)(c-buf), MANDOCERR_NOBLANKLN))
 638                         return(0);
 639
 640                 /*
 641                  * Insert a `Pp' in the case of a blank line.  Technically,
 642                  * blank lines aren't allowed, but enough manuals assume this
 643                  * behaviour that we want to work around it.
 644                  */
 645                 if ( ! mdoc_elem_alloc(m, line, offs, MDOC_Pp, NULL))
 646                         return(0);
 647
 648                 m->next = MDOC_NEXT_SIBLING;
 649                 return(1);
 650         }
 651
 652         if ( ! mdoc_word_alloc(m, line, offs, buf+offs))
 653                 return(0);
 654
 655         if (MDOC_LITERAL & m->flags)
 656                 return(1);
 657
 658         /*
 659          * End-of-sentence check.  If the last character is an unescaped
 660          * EOS character, then flag the node as being the end of a
 661          * sentence.  The front-end will know how to interpret this.
 662          */
 663
 664         assert(buf < end);
 665
 666         if (mandoc_eos(buf+offs, (size_t)(end-buf-offs)))
 667                 m->last->flags |= MDOC_EOS;
 668
 669         return(1);
 670 }
 671
 672
 673 static int
 674 macrowarn(struct mdoc *m, int ln, const char *buf, int offs)
 675 {
 676         int              rc;
 677
 678         rc = mdoc_vmsg(m, MANDOCERR_MACRO, ln, offs,
 679                         "unknown macro: %s%s",
 680                         buf, strlen(buf) > 3 ? "..." : "");
 681
 682         /* FIXME: logic should be in driver. */
 683         /* FIXME: broken, will error out and not omit a message. */
 684         return(MDOC_IGN_MACRO & m->pflags ? rc : 0);
 685 }
 686
 687
 688 /*
 689  * Parse a macro line, that is, a line beginning with the control
 690  * character.
 691  */
 692 int
 693 mdoc_pmacro(struct mdoc *m, int ln, char *buf, int offs)
 694 {
 695         enum mdoct        tok;
 696         int               i, j, sv;
 697         char              mac[5];
 698         struct mdoc_node *n;
 699
 700         /* Empty lines are ignored. */
 701
 702         offs++;
 703
 704         if ('\0' == buf[offs])
 705                 return(1);
 706
 707         i = offs;
 708
 709         /* Accept whitespace after the initial control char. */
 710
 711         if (' ' == buf[i]) {
 712                 i++;
 713                 while (buf[i] && ' ' == buf[i])
 714                         i++;
 715                 if ('\0' == buf[i])
 716                         return(1);
 717         }
 718
 719         sv = i;
 720
 721         /* Copy the first word into a nil-terminated buffer. */
 722
 723         for (j = 0; j < 4; j++, i++) {
 724                 if ('\0' == (mac[j] = buf[i]))
 725                         break;
 726                 else if (' ' == buf[i])
 727                         break;
 728
 729                 /* Check for invalid characters. */
 730
 731                 if (isgraph((u_char)buf[i]))
 732                         continue;
 733                 if ( ! mdoc_pmsg(m, ln, i, MANDOCERR_BADCHAR))
 734                         return(0);
 735                 i--;
 736         }
 737
 738         mac[j] = '\0';
 739
 740         if (j == 4 || j < 2) {
 741                 if ( ! macrowarn(m, ln, mac, sv))
 742                         goto err;
 743                 return(1);
 744         }
 745
 746         if (MDOC_MAX == (tok = mdoc_hash_find(mac))) {
 747                 if ( ! macrowarn(m, ln, mac, sv))
 748                         goto err;
 749                 return(1);
 750         }
 751
 752         /* The macro is sane.  Jump to the next word. */
 753
 754         while (buf[i] && ' ' == buf[i])
 755                 i++;
 756
 757         /*
 758          * Trailing whitespace.  Note that tabs are allowed to be passed
 759          * into the parser as "text", so we only warn about spaces here.
 760          */
 761
 762         if ('\0' == buf[i] && ' ' == buf[i - 1])
 763                 if ( ! mdoc_pmsg(m, ln, i - 1, MANDOCERR_EOLNSPACE))
 764                         goto err;
 765
 766         /*
 767          * If an initial macro or a list invocation, divert directly
 768          * into macro processing.
 769          */
 770
 771         if (NULL == m->last || MDOC_It == tok || MDOC_El == tok) {
 772                 if ( ! mdoc_macro(m, tok, ln, sv, &i, buf))
 773                         goto err;
 774                 return(1);
 775         }
 776
 777         n = m->last;
 778         assert(m->last);
 779
 780         /*
 781          * If the first macro of a `Bl -column', open an `It' block
 782          * context around the parsed macro.
 783          */
 784
 785         if (MDOC_Bl == n->tok && MDOC_BODY == n->type &&
 786                         LIST_column == n->data.Bl.type) {
 787                 m->flags |= MDOC_FREECOL;
 788                 if ( ! mdoc_macro(m, MDOC_It, ln, sv, &sv, buf))
 789                         goto err;
 790                 return(1);
 791         }
 792
 793         /*
 794          * If we're following a block-level `It' within a `Bl -column'
 795          * context (perhaps opened in the above block or in ptext()),
 796          * then open an `It' block context around the parsed macro.
 797          */
 798
 799         if (MDOC_It == n->tok && MDOC_BLOCK == n->type &&
 800                         NULL != n->parent &&
 801                         MDOC_Bl == n->parent->tok &&
 802                         LIST_column == n->parent->data.Bl.type) {
 803                 m->flags |= MDOC_FREECOL;
 804                 if ( ! mdoc_macro(m, MDOC_It, ln, sv, &sv, buf))
 805                         goto err;
 806                 return(1);
 807         }
 808
 809         /* Normal processing of a macro. */
 810
 811         if ( ! mdoc_macro(m, tok, ln, sv, &i, buf))
 812                 goto err;
 813
 814         return(1);
 815
 816 err:    /* Error out. */
 817
 818         m->flags |= MDOC_HALT;
 819         return(0);
 820 }
 821
 822