contrib/mdocml/eqn.c

   1 /*      $Id: eqn.c,v 1.61 2016/01/08 00:50:45 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #include "config.h"
  19
  20 #include <sys/types.h>
  21
  22 #include <assert.h>
  23 #include <limits.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <time.h>
  28
  29 #include "mandoc.h"
  30 #include "mandoc_aux.h"
  31 #include "libmandoc.h"
  32 #include "libroff.h"
  33
  34 #define EQN_NEST_MAX     128 /* maximum nesting of defines */
  35 #define STRNEQ(p1, sz1, p2, sz2) \
  36         ((sz1) == (sz2) && 0 == strncmp((p1), (p2), (sz1)))
  37
  38 enum    eqn_tok {
  39         EQN_TOK_DYAD = 0,
  40         EQN_TOK_VEC,
  41         EQN_TOK_UNDER,
  42         EQN_TOK_BAR,
  43         EQN_TOK_TILDE,
  44         EQN_TOK_HAT,
  45         EQN_TOK_DOT,
  46         EQN_TOK_DOTDOT,
  47         EQN_TOK_FWD,
  48         EQN_TOK_BACK,
  49         EQN_TOK_DOWN,
  50         EQN_TOK_UP,
  51         EQN_TOK_FAT,
  52         EQN_TOK_ROMAN,
  53         EQN_TOK_ITALIC,
  54         EQN_TOK_BOLD,
  55         EQN_TOK_SIZE,
  56         EQN_TOK_SUB,
  57         EQN_TOK_SUP,
  58         EQN_TOK_SQRT,
  59         EQN_TOK_OVER,
  60         EQN_TOK_FROM,
  61         EQN_TOK_TO,
  62         EQN_TOK_BRACE_OPEN,
  63         EQN_TOK_BRACE_CLOSE,
  64         EQN_TOK_GSIZE,
  65         EQN_TOK_GFONT,
  66         EQN_TOK_MARK,
  67         EQN_TOK_LINEUP,
  68         EQN_TOK_LEFT,
  69         EQN_TOK_RIGHT,
  70         EQN_TOK_PILE,
  71         EQN_TOK_LPILE,
  72         EQN_TOK_RPILE,
  73         EQN_TOK_CPILE,
  74         EQN_TOK_MATRIX,
  75         EQN_TOK_CCOL,
  76         EQN_TOK_LCOL,
  77         EQN_TOK_RCOL,
  78         EQN_TOK_DELIM,
  79         EQN_TOK_DEFINE,
  80         EQN_TOK_TDEFINE,
  81         EQN_TOK_NDEFINE,
  82         EQN_TOK_UNDEF,
  83         EQN_TOK_EOF,
  84         EQN_TOK_ABOVE,
  85         EQN_TOK__MAX
  86 };
  87
  88 static  const char *eqn_toks[EQN_TOK__MAX] = {
  89         "dyad", /* EQN_TOK_DYAD */
  90         "vec", /* EQN_TOK_VEC */
  91         "under", /* EQN_TOK_UNDER */
  92         "bar", /* EQN_TOK_BAR */
  93         "tilde", /* EQN_TOK_TILDE */
  94         "hat", /* EQN_TOK_HAT */
  95         "dot", /* EQN_TOK_DOT */
  96         "dotdot", /* EQN_TOK_DOTDOT */
  97         "fwd", /* EQN_TOK_FWD * */
  98         "back", /* EQN_TOK_BACK */
  99         "down", /* EQN_TOK_DOWN */
 100         "up", /* EQN_TOK_UP */
 101         "fat", /* EQN_TOK_FAT */
 102         "roman", /* EQN_TOK_ROMAN */
 103         "italic", /* EQN_TOK_ITALIC */
 104         "bold", /* EQN_TOK_BOLD */
 105         "size", /* EQN_TOK_SIZE */
 106         "sub", /* EQN_TOK_SUB */
 107         "sup", /* EQN_TOK_SUP */
 108         "sqrt", /* EQN_TOK_SQRT */
 109         "over", /* EQN_TOK_OVER */
 110         "from", /* EQN_TOK_FROM */
 111         "to", /* EQN_TOK_TO */
 112         "{", /* EQN_TOK_BRACE_OPEN */
 113         "}", /* EQN_TOK_BRACE_CLOSE */
 114         "gsize", /* EQN_TOK_GSIZE */
 115         "gfont", /* EQN_TOK_GFONT */
 116         "mark", /* EQN_TOK_MARK */
 117         "lineup", /* EQN_TOK_LINEUP */
 118         "left", /* EQN_TOK_LEFT */
 119         "right", /* EQN_TOK_RIGHT */
 120         "pile", /* EQN_TOK_PILE */
 121         "lpile", /* EQN_TOK_LPILE */
 122         "rpile", /* EQN_TOK_RPILE */
 123         "cpile", /* EQN_TOK_CPILE */
 124         "matrix", /* EQN_TOK_MATRIX */
 125         "ccol", /* EQN_TOK_CCOL */
 126         "lcol", /* EQN_TOK_LCOL */
 127         "rcol", /* EQN_TOK_RCOL */
 128         "delim", /* EQN_TOK_DELIM */
 129         "define", /* EQN_TOK_DEFINE */
 130         "tdefine", /* EQN_TOK_TDEFINE */
 131         "ndefine", /* EQN_TOK_NDEFINE */
 132         "undef", /* EQN_TOK_UNDEF */
 133         NULL, /* EQN_TOK_EOF */
 134         "above", /* EQN_TOK_ABOVE */
 135 };
 136
 137 enum    eqn_symt {
 138         EQNSYM_alpha,
 139         EQNSYM_beta,
 140         EQNSYM_chi,
 141         EQNSYM_delta,
 142         EQNSYM_epsilon,
 143         EQNSYM_eta,
 144         EQNSYM_gamma,
 145         EQNSYM_iota,
 146         EQNSYM_kappa,
 147         EQNSYM_lambda,
 148         EQNSYM_mu,
 149         EQNSYM_nu,
 150         EQNSYM_omega,
 151         EQNSYM_omicron,
 152         EQNSYM_phi,
 153         EQNSYM_pi,
 154         EQNSYM_ps,
 155         EQNSYM_rho,
 156         EQNSYM_sigma,
 157         EQNSYM_tau,
 158         EQNSYM_theta,
 159         EQNSYM_upsilon,
 160         EQNSYM_xi,
 161         EQNSYM_zeta,
 162         EQNSYM_DELTA,
 163         EQNSYM_GAMMA,
 164         EQNSYM_LAMBDA,
 165         EQNSYM_OMEGA,
 166         EQNSYM_PHI,
 167         EQNSYM_PI,
 168         EQNSYM_PSI,
 169         EQNSYM_SIGMA,
 170         EQNSYM_THETA,
 171         EQNSYM_UPSILON,
 172         EQNSYM_XI,
 173         EQNSYM_inter,
 174         EQNSYM_union,
 175         EQNSYM_prod,
 176         EQNSYM_int,
 177         EQNSYM_sum,
 178         EQNSYM_grad,
 179         EQNSYM_del,
 180         EQNSYM_times,
 181         EQNSYM_cdot,
 182         EQNSYM_nothing,
 183         EQNSYM_approx,
 184         EQNSYM_prime,
 185         EQNSYM_half,
 186         EQNSYM_partial,
 187         EQNSYM_inf,
 188         EQNSYM_muchgreat,
 189         EQNSYM_muchless,
 190         EQNSYM_larrow,
 191         EQNSYM_rarrow,
 192         EQNSYM_pm,
 193         EQNSYM_nequal,
 194         EQNSYM_equiv,
 195         EQNSYM_lessequal,
 196         EQNSYM_moreequal,
 197         EQNSYM_minus,
 198         EQNSYM__MAX
 199 };
 200
 201 struct  eqnsym {
 202         const char      *str;
 203         const char      *sym;
 204 };
 205
 206 static  const struct eqnsym eqnsyms[EQNSYM__MAX] = {
 207         { "alpha", "*a" }, /* EQNSYM_alpha */
 208         { "beta", "*b" }, /* EQNSYM_beta */
 209         { "chi", "*x" }, /* EQNSYM_chi */
 210         { "delta", "*d" }, /* EQNSYM_delta */
 211         { "epsilon", "*e" }, /* EQNSYM_epsilon */
 212         { "eta", "*y" }, /* EQNSYM_eta */
 213         { "gamma", "*g" }, /* EQNSYM_gamma */
 214         { "iota", "*i" }, /* EQNSYM_iota */
 215         { "kappa", "*k" }, /* EQNSYM_kappa */
 216         { "lambda", "*l" }, /* EQNSYM_lambda */
 217         { "mu", "*m" }, /* EQNSYM_mu */
 218         { "nu", "*n" }, /* EQNSYM_nu */
 219         { "omega", "*w" }, /* EQNSYM_omega */
 220         { "omicron", "*o" }, /* EQNSYM_omicron */
 221         { "phi", "*f" }, /* EQNSYM_phi */
 222         { "pi", "*p" }, /* EQNSYM_pi */
 223         { "psi", "*q" }, /* EQNSYM_psi */
 224         { "rho", "*r" }, /* EQNSYM_rho */
 225         { "sigma", "*s" }, /* EQNSYM_sigma */
 226         { "tau", "*t" }, /* EQNSYM_tau */
 227         { "theta", "*h" }, /* EQNSYM_theta */
 228         { "upsilon", "*u" }, /* EQNSYM_upsilon */
 229         { "xi", "*c" }, /* EQNSYM_xi */
 230         { "zeta", "*z" }, /* EQNSYM_zeta */
 231         { "DELTA", "*D" }, /* EQNSYM_DELTA */
 232         { "GAMMA", "*G" }, /* EQNSYM_GAMMA */
 233         { "LAMBDA", "*L" }, /* EQNSYM_LAMBDA */
 234         { "OMEGA", "*W" }, /* EQNSYM_OMEGA */
 235         { "PHI", "*F" }, /* EQNSYM_PHI */
 236         { "PI", "*P" }, /* EQNSYM_PI */
 237         { "PSI", "*Q" }, /* EQNSYM_PSI */
 238         { "SIGMA", "*S" }, /* EQNSYM_SIGMA */
 239         { "THETA", "*H" }, /* EQNSYM_THETA */
 240         { "UPSILON", "*U" }, /* EQNSYM_UPSILON */
 241         { "XI", "*C" }, /* EQNSYM_XI */
 242         { "inter", "ca" }, /* EQNSYM_inter */
 243         { "union", "cu" }, /* EQNSYM_union */
 244         { "prod", "product" }, /* EQNSYM_prod */
 245         { "int", "integral" }, /* EQNSYM_int */
 246         { "sum", "sum" }, /* EQNSYM_sum */
 247         { "grad", "gr" }, /* EQNSYM_grad */
 248         { "del", "gr" }, /* EQNSYM_del */
 249         { "times", "mu" }, /* EQNSYM_times */
 250         { "cdot", "pc" }, /* EQNSYM_cdot */
 251         { "nothing", "&" }, /* EQNSYM_nothing */
 252         { "approx", "~~" }, /* EQNSYM_approx */
 253         { "prime", "fm" }, /* EQNSYM_prime */
 254         { "half", "12" }, /* EQNSYM_half */
 255         { "partial", "pd" }, /* EQNSYM_partial */
 256         { "inf", "if" }, /* EQNSYM_inf */
 257         { ">>", ">>" }, /* EQNSYM_muchgreat */
 258         { "<<", "<<" }, /* EQNSYM_muchless */
 259         { "<-", "<-" }, /* EQNSYM_larrow */
 260         { "->", "->" }, /* EQNSYM_rarrow */
 261         { "+-", "+-" }, /* EQNSYM_pm */
 262         { "!=", "!=" }, /* EQNSYM_nequal */
 263         { "==", "==" }, /* EQNSYM_equiv */
 264         { "<=", "<=" }, /* EQNSYM_lessequal */
 265         { ">=", ">=" }, /* EQNSYM_moreequal */
 266         { "-", "mi" }, /* EQNSYM_minus */
 267 };
 268
 269 static  struct eqn_box  *eqn_box_alloc(struct eqn_node *, struct eqn_box *);
 270 static  void             eqn_box_free(struct eqn_box *);
 271 static  struct eqn_box  *eqn_box_makebinary(struct eqn_node *,
 272                                 enum eqn_post, struct eqn_box *);
 273 static  void             eqn_def(struct eqn_node *);
 274 static  struct eqn_def  *eqn_def_find(struct eqn_node *, const char *, size_t);
 275 static  void             eqn_delim(struct eqn_node *);
 276 static  const char      *eqn_next(struct eqn_node *, char, size_t *, int);
 277 static  const char      *eqn_nextrawtok(struct eqn_node *, size_t *);
 278 static  const char      *eqn_nexttok(struct eqn_node *, size_t *);
 279 static  enum rofferr     eqn_parse(struct eqn_node *, struct eqn_box *);
 280 static  enum eqn_tok     eqn_tok_parse(struct eqn_node *, char **);
 281 static  void             eqn_undef(struct eqn_node *);
 282
 283
 284 enum rofferr
 285 eqn_read(struct eqn_node **epp, int ln,
 286                 const char *p, int pos, int *offs)
 287 {
 288         size_t           sz;
 289         struct eqn_node *ep;
 290         enum rofferr     er;
 291
 292         ep = *epp;
 293
 294         /*
 295          * If we're the terminating mark, unset our equation status and
 296          * validate the full equation.
 297          */
 298
 299         if (0 == strncmp(p, ".EN", 3)) {
 300                 er = eqn_end(epp);
 301                 p += 3;
 302                 while (' ' == *p || '\t' == *p)
 303                         p++;
 304                 if ('\0' == *p)
 305                         return er;
 306                 mandoc_vmsg(MANDOCERR_ARG_SKIP, ep->parse,
 307                     ln, pos, "EN %s", p);
 308                 return er;
 309         }
 310
 311         /*
 312          * Build up the full string, replacing all newlines with regular
 313          * whitespace.
 314          */
 315
 316         sz = strlen(p + pos) + 1;
 317         ep->data = mandoc_realloc(ep->data, ep->sz + sz + 1);
 318
 319         /* First invocation: nil terminate the string. */
 320
 321         if (0 == ep->sz)
 322                 *ep->data = '\0';
 323
 324         ep->sz += sz;
 325         strlcat(ep->data, p + pos, ep->sz + 1);
 326         strlcat(ep->data, " ", ep->sz + 1);
 327         return ROFF_IGN;
 328 }
 329
 330 struct eqn_node *
 331 eqn_alloc(int pos, int line, struct mparse *parse)
 332 {
 333         struct eqn_node *p;
 334
 335         p = mandoc_calloc(1, sizeof(struct eqn_node));
 336
 337         p->parse = parse;
 338         p->eqn.ln = line;
 339         p->eqn.pos = pos;
 340         p->gsize = EQN_DEFSIZE;
 341
 342         return p;
 343 }
 344
 345 /*
 346  * Find the key "key" of the give size within our eqn-defined values.
 347  */
 348 static struct eqn_def *
 349 eqn_def_find(struct eqn_node *ep, const char *key, size_t sz)
 350 {
 351         int              i;
 352
 353         for (i = 0; i < (int)ep->defsz; i++)
 354                 if (ep->defs[i].keysz && STRNEQ(ep->defs[i].key,
 355                     ep->defs[i].keysz, key, sz))
 356                         return &ep->defs[i];
 357
 358         return NULL;
 359 }
 360
 361 /*
 362  * Get the next token from the input stream using the given quote
 363  * character.
 364  * Optionally make any replacements.
 365  */
 366 static const char *
 367 eqn_next(struct eqn_node *ep, char quote, size_t *sz, int repl)
 368 {
 369         char            *start, *next;
 370         int              q, diff, lim;
 371         size_t           ssz, dummy;
 372         struct eqn_def  *def;
 373
 374         if (NULL == sz)
 375                 sz = &dummy;
 376
 377         lim = 0;
 378         ep->rew = ep->cur;
 379 again:
 380         /* Prevent self-definitions. */
 381
 382         if (lim >= EQN_NEST_MAX) {
 383                 mandoc_msg(MANDOCERR_ROFFLOOP, ep->parse,
 384                     ep->eqn.ln, ep->eqn.pos, NULL);
 385                 return NULL;
 386         }
 387
 388         ep->cur = ep->rew;
 389         start = &ep->data[(int)ep->cur];
 390         q = 0;
 391
 392         if ('\0' == *start)
 393                 return NULL;
 394
 395         if (quote == *start) {
 396                 ep->cur++;
 397                 q = 1;
 398         }
 399
 400         start = &ep->data[(int)ep->cur];
 401
 402         if ( ! q) {
 403                 if ('{' == *start || '}' == *start)
 404                         ssz = 1;
 405                 else
 406                         ssz = strcspn(start + 1, " ^~\"{}\t") + 1;
 407                 next = start + (int)ssz;
 408                 if ('\0' == *next)
 409                         next = NULL;
 410         } else
 411                 next = strchr(start, quote);
 412
 413         if (NULL != next) {
 414                 *sz = (size_t)(next - start);
 415                 ep->cur += *sz;
 416                 if (q)
 417                         ep->cur++;
 418                 while (' ' == ep->data[(int)ep->cur] ||
 419                     '\t' == ep->data[(int)ep->cur] ||
 420                     '^' == ep->data[(int)ep->cur] ||
 421                     '~' == ep->data[(int)ep->cur])
 422                         ep->cur++;
 423         } else {
 424                 if (q)
 425                         mandoc_msg(MANDOCERR_ARG_QUOTE, ep->parse,
 426                             ep->eqn.ln, ep->eqn.pos, NULL);
 427                 next = strchr(start, '\0');
 428                 *sz = (size_t)(next - start);
 429                 ep->cur += *sz;
 430         }
 431
 432         /* Quotes aren't expanded for values. */
 433
 434         if (q || ! repl)
 435                 return start;
 436
 437         if (NULL != (def = eqn_def_find(ep, start, *sz))) {
 438                 diff = def->valsz - *sz;
 439
 440                 if (def->valsz > *sz) {
 441                         ep->sz += diff;
 442                         ep->data = mandoc_realloc(ep->data, ep->sz + 1);
 443                         ep->data[ep->sz] = '\0';
 444                         start = &ep->data[(int)ep->rew];
 445                 }
 446
 447                 diff = def->valsz - *sz;
 448                 memmove(start + *sz + diff, start + *sz,
 449                     (strlen(start) - *sz) + 1);
 450                 memcpy(start, def->val, def->valsz);
 451                 lim++;
 452                 goto again;
 453         }
 454
 455         return start;
 456 }
 457
 458 /*
 459  * Get the next delimited token using the default current quote
 460  * character.
 461  */
 462 static const char *
 463 eqn_nexttok(struct eqn_node *ep, size_t *sz)
 464 {
 465
 466         return eqn_next(ep, '"', sz, 1);
 467 }
 468
 469 /*
 470  * Get next token without replacement.
 471  */
 472 static const char *
 473 eqn_nextrawtok(struct eqn_node *ep, size_t *sz)
 474 {
 475
 476         return eqn_next(ep, '"', sz, 0);
 477 }
 478
 479 /*
 480  * Parse a token from the stream of text.
 481  * A token consists of one of the recognised eqn(7) strings.
 482  * Strings are separated by delimiting marks.
 483  * This returns EQN_TOK_EOF when there are no more tokens.
 484  * If the token is an unrecognised string literal, then it returns
 485  * EQN_TOK__MAX and sets the "p" pointer to an allocated, nil-terminated
 486  * string.
 487  * This must be later freed with free(3).
 488  */
 489 static enum eqn_tok
 490 eqn_tok_parse(struct eqn_node *ep, char **p)
 491 {
 492         const char      *start;
 493         size_t           i, sz;
 494         int              quoted;
 495
 496         if (NULL != p)
 497                 *p = NULL;
 498
 499         quoted = ep->data[ep->cur] == '"';
 500
 501         if (NULL == (start = eqn_nexttok(ep, &sz)))
 502                 return EQN_TOK_EOF;
 503
 504         if (quoted) {
 505                 if (p != NULL)
 506                         *p = mandoc_strndup(start, sz);
 507                 return EQN_TOK__MAX;
 508         }
 509
 510         for (i = 0; i < EQN_TOK__MAX; i++) {
 511                 if (NULL == eqn_toks[i])
 512                         continue;
 513                 if (STRNEQ(start, sz, eqn_toks[i], strlen(eqn_toks[i])))
 514                         break;
 515         }
 516
 517         if (i == EQN_TOK__MAX && NULL != p)
 518                 *p = mandoc_strndup(start, sz);
 519
 520         return i;
 521 }
 522
 523 static void
 524 eqn_box_free(struct eqn_box *bp)
 525 {
 526
 527         if (bp->first)
 528                 eqn_box_free(bp->first);
 529         if (bp->next)
 530                 eqn_box_free(bp->next);
 531
 532         free(bp->text);
 533         free(bp->left);
 534         free(bp->right);
 535         free(bp->top);
 536         free(bp->bottom);
 537         free(bp);
 538 }
 539
 540 /*
 541  * Allocate a box as the last child of the parent node.
 542  */
 543 static struct eqn_box *
 544 eqn_box_alloc(struct eqn_node *ep, struct eqn_box *parent)
 545 {
 546         struct eqn_box  *bp;
 547
 548         bp = mandoc_calloc(1, sizeof(struct eqn_box));
 549         bp->parent = parent;
 550         bp->parent->args++;
 551         bp->expectargs = UINT_MAX;
 552         bp->size = ep->gsize;
 553
 554         if (NULL != parent->first) {
 555                 parent->last->next = bp;
 556                 bp->prev = parent->last;
 557         } else
 558                 parent->first = bp;
 559
 560         parent->last = bp;
 561         return bp;
 562 }
 563
 564 /*
 565  * Reparent the current last node (of the current parent) under a new
 566  * EQN_SUBEXPR as the first element.
 567  * Then return the new parent.
 568  * The new EQN_SUBEXPR will have a two-child limit.
 569  */
 570 static struct eqn_box *
 571 eqn_box_makebinary(struct eqn_node *ep,
 572         enum eqn_post pos, struct eqn_box *parent)
 573 {
 574         struct eqn_box  *b, *newb;
 575
 576         assert(NULL != parent->last);
 577         b = parent->last;
 578         if (parent->last == parent->first)
 579                 parent->first = NULL;
 580         parent->args--;
 581         parent->last = b->prev;
 582         b->prev = NULL;
 583         newb = eqn_box_alloc(ep, parent);
 584         newb->pos = pos;
 585         newb->type = EQN_SUBEXPR;
 586         newb->expectargs = 2;
 587         newb->args = 1;
 588         newb->first = newb->last = b;
 589         newb->first->next = NULL;
 590         b->parent = newb;
 591         return newb;
 592 }
 593
 594 /*
 595  * Parse the "delim" control statement.
 596  */
 597 static void
 598 eqn_delim(struct eqn_node *ep)
 599 {
 600         const char      *start;
 601         size_t           sz;
 602
 603         if ((start = eqn_nextrawtok(ep, &sz)) == NULL)
 604                 mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 605                     ep->eqn.ln, ep->eqn.pos, "delim");
 606         else if (strncmp(start, "off", 3) == 0)
 607                 ep->delim = 0;
 608         else if (strncmp(start, "on", 2) == 0) {
 609                 if (ep->odelim && ep->cdelim)
 610                         ep->delim = 1;
 611         } else if (start[1] != '\0') {
 612                 ep->odelim = start[0];
 613                 ep->cdelim = start[1];
 614                 ep->delim = 1;
 615         }
 616 }
 617
 618 /*
 619  * Undefine a previously-defined string.
 620  */
 621 static void
 622 eqn_undef(struct eqn_node *ep)
 623 {
 624         const char      *start;
 625         struct eqn_def  *def;
 626         size_t           sz;
 627
 628         if ((start = eqn_nextrawtok(ep, &sz)) == NULL) {
 629                 mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 630                     ep->eqn.ln, ep->eqn.pos, "undef");
 631                 return;
 632         }
 633         if ((def = eqn_def_find(ep, start, sz)) == NULL)
 634                 return;
 635         free(def->key);
 636         free(def->val);
 637         def->key = def->val = NULL;
 638         def->keysz = def->valsz = 0;
 639 }
 640
 641 static void
 642 eqn_def(struct eqn_node *ep)
 643 {
 644         const char      *start;
 645         size_t           sz;
 646         struct eqn_def  *def;
 647         int              i;
 648
 649         if ((start = eqn_nextrawtok(ep, &sz)) == NULL) {
 650                 mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 651                     ep->eqn.ln, ep->eqn.pos, "define");
 652                 return;
 653         }
 654
 655         /*
 656          * Search for a key that already exists.
 657          * Create a new key if none is found.
 658          */
 659         if (NULL == (def = eqn_def_find(ep, start, sz))) {
 660                 /* Find holes in string array. */
 661                 for (i = 0; i < (int)ep->defsz; i++)
 662                         if (0 == ep->defs[i].keysz)
 663                                 break;
 664
 665                 if (i == (int)ep->defsz) {
 666                         ep->defsz++;
 667                         ep->defs = mandoc_reallocarray(ep->defs,
 668                             ep->defsz, sizeof(struct eqn_def));
 669                         ep->defs[i].key = ep->defs[i].val = NULL;
 670                 }
 671
 672                 def = ep->defs + i;
 673                 free(def->key);
 674                 def->key = mandoc_strndup(start, sz);
 675                 def->keysz = sz;
 676         }
 677
 678         start = eqn_next(ep, ep->data[(int)ep->cur], &sz, 0);
 679         if (start == NULL) {
 680                 mandoc_vmsg(MANDOCERR_REQ_EMPTY, ep->parse,
 681                     ep->eqn.ln, ep->eqn.pos, "define %s", def->key);
 682                 free(def->key);
 683                 free(def->val);
 684                 def->key = def->val = NULL;
 685                 def->keysz = def->valsz = 0;
 686                 return;
 687         }
 688         free(def->val);
 689         def->val = mandoc_strndup(start, sz);
 690         def->valsz = sz;
 691 }
 692
 693 /*
 694  * Recursively parse an eqn(7) expression.
 695  */
 696 static enum rofferr
 697 eqn_parse(struct eqn_node *ep, struct eqn_box *parent)
 698 {
 699         char             sym[64];
 700         struct eqn_box  *cur;
 701         const char      *start;
 702         char            *p;
 703         size_t           i, sz;
 704         enum eqn_tok     tok, subtok;
 705         enum eqn_post    pos;
 706         int              size;
 707
 708         assert(parent != NULL);
 709
 710         /*
 711          * Empty equation.
 712          * Do not add it to the high-level syntax tree.
 713          */
 714
 715         if (ep->data == NULL)
 716                 return ROFF_IGN;
 717
 718 next_tok:
 719         tok = eqn_tok_parse(ep, &p);
 720
 721 this_tok:
 722         switch (tok) {
 723         case (EQN_TOK_UNDEF):
 724                 eqn_undef(ep);
 725                 break;
 726         case (EQN_TOK_NDEFINE):
 727         case (EQN_TOK_DEFINE):
 728                 eqn_def(ep);
 729                 break;
 730         case (EQN_TOK_TDEFINE):
 731                 if (eqn_nextrawtok(ep, NULL) == NULL ||
 732                     eqn_next(ep, ep->data[(int)ep->cur], NULL, 0) == NULL)
 733                         mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 734                             ep->eqn.ln, ep->eqn.pos, "tdefine");
 735                 break;
 736         case (EQN_TOK_DELIM):
 737                 eqn_delim(ep);
 738                 break;
 739         case (EQN_TOK_GFONT):
 740                 if (eqn_nextrawtok(ep, NULL) == NULL)
 741                         mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 742                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 743                 break;
 744         case (EQN_TOK_MARK):
 745         case (EQN_TOK_LINEUP):
 746                 /* Ignore these. */
 747                 break;
 748         case (EQN_TOK_DYAD):
 749         case (EQN_TOK_VEC):
 750         case (EQN_TOK_UNDER):
 751         case (EQN_TOK_BAR):
 752         case (EQN_TOK_TILDE):
 753         case (EQN_TOK_HAT):
 754         case (EQN_TOK_DOT):
 755         case (EQN_TOK_DOTDOT):
 756                 if (parent->last == NULL) {
 757                         mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
 758                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 759                         cur = eqn_box_alloc(ep, parent);
 760                         cur->type = EQN_TEXT;
 761                         cur->text = mandoc_strdup("");
 762                 }
 763                 parent = eqn_box_makebinary(ep, EQNPOS_NONE, parent);
 764                 parent->type = EQN_LISTONE;
 765                 parent->expectargs = 1;
 766                 switch (tok) {
 767                 case (EQN_TOK_DOTDOT):
 768                         strlcpy(sym, "\\[ad]", sizeof(sym));
 769                         break;
 770                 case (EQN_TOK_VEC):
 771                         strlcpy(sym, "\\[->]", sizeof(sym));
 772                         break;
 773                 case (EQN_TOK_DYAD):
 774                         strlcpy(sym, "\\[<>]", sizeof(sym));
 775                         break;
 776                 case (EQN_TOK_TILDE):
 777                         strlcpy(sym, "\\[a~]", sizeof(sym));
 778                         break;
 779                 case (EQN_TOK_UNDER):
 780                         strlcpy(sym, "\\[ul]", sizeof(sym));
 781                         break;
 782                 case (EQN_TOK_BAR):
 783                         strlcpy(sym, "\\[rl]", sizeof(sym));
 784                         break;
 785                 case (EQN_TOK_DOT):
 786                         strlcpy(sym, "\\[a.]", sizeof(sym));
 787                         break;
 788                 case (EQN_TOK_HAT):
 789                         strlcpy(sym, "\\[ha]", sizeof(sym));
 790                         break;
 791                 default:
 792                         abort();
 793                 }
 794
 795                 switch (tok) {
 796                 case (EQN_TOK_DOTDOT):
 797                 case (EQN_TOK_VEC):
 798                 case (EQN_TOK_DYAD):
 799                 case (EQN_TOK_TILDE):
 800                 case (EQN_TOK_BAR):
 801                 case (EQN_TOK_DOT):
 802                 case (EQN_TOK_HAT):
 803                         parent->top = mandoc_strdup(sym);
 804                         break;
 805                 case (EQN_TOK_UNDER):
 806                         parent->bottom = mandoc_strdup(sym);
 807                         break;
 808                 default:
 809                         abort();
 810                 }
 811                 parent = parent->parent;
 812                 break;
 813         case (EQN_TOK_FWD):
 814         case (EQN_TOK_BACK):
 815         case (EQN_TOK_DOWN):
 816         case (EQN_TOK_UP):
 817                 subtok = eqn_tok_parse(ep, NULL);
 818                 if (subtok != EQN_TOK__MAX) {
 819                         mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 820                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 821                         tok = subtok;
 822                         goto this_tok;
 823                 }
 824                 break;
 825         case (EQN_TOK_FAT):
 826         case (EQN_TOK_ROMAN):
 827         case (EQN_TOK_ITALIC):
 828         case (EQN_TOK_BOLD):
 829                 while (parent->args == parent->expectargs)
 830                         parent = parent->parent;
 831                 /*
 832                  * These values apply to the next word or sequence of
 833                  * words; thus, we mark that we'll have a child with
 834                  * exactly one of those.
 835                  */
 836                 parent = eqn_box_alloc(ep, parent);
 837                 parent->type = EQN_LISTONE;
 838                 parent->expectargs = 1;
 839                 switch (tok) {
 840                 case (EQN_TOK_FAT):
 841                         parent->font = EQNFONT_FAT;
 842                         break;
 843                 case (EQN_TOK_ROMAN):
 844                         parent->font = EQNFONT_ROMAN;
 845                         break;
 846                 case (EQN_TOK_ITALIC):
 847                         parent->font = EQNFONT_ITALIC;
 848                         break;
 849                 case (EQN_TOK_BOLD):
 850                         parent->font = EQNFONT_BOLD;
 851                         break;
 852                 default:
 853                         abort();
 854                 }
 855                 break;
 856         case (EQN_TOK_SIZE):
 857         case (EQN_TOK_GSIZE):
 858                 /* Accept two values: integral size and a single. */
 859                 if (NULL == (start = eqn_nexttok(ep, &sz))) {
 860                         mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
 861                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 862                         break;
 863                 }
 864                 size = mandoc_strntoi(start, sz, 10);
 865                 if (-1 == size) {
 866                         mandoc_msg(MANDOCERR_IT_NONUM, ep->parse,
 867                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 868                         break;
 869                 }
 870                 if (EQN_TOK_GSIZE == tok) {
 871                         ep->gsize = size;
 872                         break;
 873                 }
 874                 parent = eqn_box_alloc(ep, parent);
 875                 parent->type = EQN_LISTONE;
 876                 parent->expectargs = 1;
 877                 parent->size = size;
 878                 break;
 879         case (EQN_TOK_FROM):
 880         case (EQN_TOK_TO):
 881         case (EQN_TOK_SUB):
 882         case (EQN_TOK_SUP):
 883                 /*
 884                  * We have a left-right-associative expression.
 885                  * Repivot under a positional node, open a child scope
 886                  * and keep on reading.
 887                  */
 888                 if (parent->last == NULL) {
 889                         mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
 890                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 891                         cur = eqn_box_alloc(ep, parent);
 892                         cur->type = EQN_TEXT;
 893                         cur->text = mandoc_strdup("");
 894                 }
 895                 /* Handle the "subsup" and "fromto" positions. */
 896                 if (EQN_TOK_SUP == tok && parent->pos == EQNPOS_SUB) {
 897                         parent->expectargs = 3;
 898                         parent->pos = EQNPOS_SUBSUP;
 899                         break;
 900                 }
 901                 if (EQN_TOK_TO == tok && parent->pos == EQNPOS_FROM) {
 902                         parent->expectargs = 3;
 903                         parent->pos = EQNPOS_FROMTO;
 904                         break;
 905                 }
 906                 switch (tok) {
 907                 case (EQN_TOK_FROM):
 908                         pos = EQNPOS_FROM;
 909                         break;
 910                 case (EQN_TOK_TO):
 911                         pos = EQNPOS_TO;
 912                         break;
 913                 case (EQN_TOK_SUP):
 914                         pos = EQNPOS_SUP;
 915                         break;
 916                 case (EQN_TOK_SUB):
 917                         pos = EQNPOS_SUB;
 918                         break;
 919                 default:
 920                         abort();
 921                 }
 922                 parent = eqn_box_makebinary(ep, pos, parent);
 923                 break;
 924         case (EQN_TOK_SQRT):
 925                 while (parent->args == parent->expectargs)
 926                         parent = parent->parent;
 927                 /*
 928                  * Accept a left-right-associative set of arguments just
 929                  * like sub and sup and friends but without rebalancing
 930                  * under a pivot.
 931                  */
 932                 parent = eqn_box_alloc(ep, parent);
 933                 parent->type = EQN_SUBEXPR;
 934                 parent->pos = EQNPOS_SQRT;
 935                 parent->expectargs = 1;
 936                 break;
 937         case (EQN_TOK_OVER):
 938                 /*
 939                  * We have a right-left-associative fraction.
 940                  * Close out anything that's currently open, then
 941                  * rebalance and continue reading.
 942                  */
 943                 if (parent->last == NULL) {
 944                         mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
 945                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 946                         cur = eqn_box_alloc(ep, parent);
 947                         cur->type = EQN_TEXT;
 948                         cur->text = mandoc_strdup("");
 949                 }
 950                 while (EQN_SUBEXPR == parent->type)
 951                         parent = parent->parent;
 952                 parent = eqn_box_makebinary(ep, EQNPOS_OVER, parent);
 953                 break;
 954         case (EQN_TOK_RIGHT):
 955         case (EQN_TOK_BRACE_CLOSE):
 956                 /*
 957                  * Close out the existing brace.
 958                  * FIXME: this is a shitty sentinel: we should really
 959                  * have a native EQN_BRACE type or whatnot.
 960                  */
 961                 for (cur = parent; cur != NULL; cur = cur->parent)
 962                         if (cur->type == EQN_LIST &&
 963                             (tok == EQN_TOK_BRACE_CLOSE ||
 964                              cur->left != NULL))
 965                                 break;
 966                 if (cur == NULL) {
 967                         mandoc_msg(MANDOCERR_BLK_NOTOPEN, ep->parse,
 968                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
 969                         break;
 970                 }
 971                 parent = cur;
 972                 if (EQN_TOK_RIGHT == tok) {
 973                         if (NULL == (start = eqn_nexttok(ep, &sz))) {
 974                                 mandoc_msg(MANDOCERR_REQ_EMPTY,
 975                                     ep->parse, ep->eqn.ln,
 976                                     ep->eqn.pos, eqn_toks[tok]);
 977                                 break;
 978                         }
 979                         /* Handling depends on right/left. */
 980                         if (STRNEQ(start, sz, "ceiling", 7)) {
 981                                 strlcpy(sym, "\\[rc]", sizeof(sym));
 982                                 parent->right = mandoc_strdup(sym);
 983                         } else if (STRNEQ(start, sz, "floor", 5)) {
 984                                 strlcpy(sym, "\\[rf]", sizeof(sym));
 985                                 parent->right = mandoc_strdup(sym);
 986                         } else
 987                                 parent->right = mandoc_strndup(start, sz);
 988                 }
 989                 parent = parent->parent;
 990                 if (tok == EQN_TOK_BRACE_CLOSE &&
 991                     (parent->type == EQN_PILE ||
 992                      parent->type == EQN_MATRIX))
 993                         parent = parent->parent;
 994                 /* Close out any "singleton" lists. */
 995                 while (parent->type == EQN_LISTONE &&
 996                     parent->args == parent->expectargs)
 997                         parent = parent->parent;
 998                 break;
 999         case (EQN_TOK_BRACE_OPEN):
1000         case (EQN_TOK_LEFT):
1001                 /*
1002                  * If we already have something in the stack and we're
1003                  * in an expression, then rewind til we're not any more
1004                  * (just like with the text node).
1005                  */
1006                 while (parent->args == parent->expectargs)
1007                         parent = parent->parent;
1008                 if (EQN_TOK_LEFT == tok &&
1009                     (start = eqn_nexttok(ep, &sz)) == NULL) {
1010                         mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
1011                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
1012                         break;
1013                 }
1014                 parent = eqn_box_alloc(ep, parent);
1015                 parent->type = EQN_LIST;
1016                 if (EQN_TOK_LEFT == tok) {
1017                         if (STRNEQ(start, sz, "ceiling", 7)) {
1018                                 strlcpy(sym, "\\[lc]", sizeof(sym));
1019                                 parent->left = mandoc_strdup(sym);
1020                         } else if (STRNEQ(start, sz, "floor", 5)) {
1021                                 strlcpy(sym, "\\[lf]", sizeof(sym));
1022                                 parent->left = mandoc_strdup(sym);
1023                         } else
1024                                 parent->left = mandoc_strndup(start, sz);
1025                 }
1026                 break;
1027         case (EQN_TOK_PILE):
1028         case (EQN_TOK_LPILE):
1029         case (EQN_TOK_RPILE):
1030         case (EQN_TOK_CPILE):
1031         case (EQN_TOK_CCOL):
1032         case (EQN_TOK_LCOL):
1033         case (EQN_TOK_RCOL):
1034                 while (parent->args == parent->expectargs)
1035                         parent = parent->parent;
1036                 parent = eqn_box_alloc(ep, parent);
1037                 parent->type = EQN_PILE;
1038                 parent->expectargs = 1;
1039                 break;
1040         case (EQN_TOK_ABOVE):
1041                 for (cur = parent; cur != NULL; cur = cur->parent)
1042                         if (cur->type == EQN_PILE)
1043                                 break;
1044                 if (cur == NULL) {
1045                         mandoc_msg(MANDOCERR_IT_STRAY, ep->parse,
1046                             ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
1047                         break;
1048                 }
1049                 parent = eqn_box_alloc(ep, cur);
1050                 parent->type = EQN_LIST;
1051                 break;
1052         case (EQN_TOK_MATRIX):
1053                 while (parent->args == parent->expectargs)
1054                         parent = parent->parent;
1055                 parent = eqn_box_alloc(ep, parent);
1056                 parent->type = EQN_MATRIX;
1057                 parent->expectargs = 1;
1058                 break;
1059         case (EQN_TOK_EOF):
1060                 /*
1061                  * End of file!
1062                  * TODO: make sure we're not in an open subexpression.
1063                  */
1064                 return ROFF_EQN;
1065         default:
1066                 assert(tok == EQN_TOK__MAX);
1067                 assert(NULL != p);
1068                 /*
1069                  * If we already have something in the stack and we're
1070                  * in an expression, then rewind til we're not any more.
1071                  */
1072                 while (parent->args == parent->expectargs)
1073                         parent = parent->parent;
1074                 cur = eqn_box_alloc(ep, parent);
1075                 cur->type = EQN_TEXT;
1076                 for (i = 0; i < EQNSYM__MAX; i++)
1077                         if (0 == strcmp(eqnsyms[i].str, p)) {
1078                                 (void)snprintf(sym, sizeof(sym),
1079                                         "\\[%s]", eqnsyms[i].sym);
1080                                 cur->text = mandoc_strdup(sym);
1081                                 free(p);
1082                                 break;
1083                         }
1084
1085                 if (i == EQNSYM__MAX)
1086                         cur->text = p;
1087                 /*
1088                  * Post-process list status.
1089                  */
1090                 while (parent->type == EQN_LISTONE &&
1091                     parent->args == parent->expectargs)
1092                         parent = parent->parent;
1093                 break;
1094         }
1095         goto next_tok;
1096 }
1097
1098 enum rofferr
1099 eqn_end(struct eqn_node **epp)
1100 {
1101         struct eqn_node *ep;
1102
1103         ep = *epp;
1104         *epp = NULL;
1105
1106         ep->eqn.root = mandoc_calloc(1, sizeof(struct eqn_box));
1107         ep->eqn.root->expectargs = UINT_MAX;
1108         return eqn_parse(ep, ep->eqn.root);
1109 }
1110
1111 void
1112 eqn_free(struct eqn_node *p)
1113 {
1114         int              i;
1115
1116         eqn_box_free(p->eqn.root);
1117
1118         for (i = 0; i < (int)p->defsz; i++) {
1119                 free(p->defs[i].key);
1120                 free(p->defs[i].val);
1121         }
1122
1123         free(p->data);
1124         free(p->defs);
1125         free(p);
1126 }