mansearch.c

   1 /*      $Id: mansearch.c,v 1.82 2019/07/01 22:56:24 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2012 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2013-2018 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 AUTHORS DISCLAIM ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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/mman.h>
  21 #include <sys/types.h>
  22
  23 #include <assert.h>
  24 #if HAVE_ERR
  25 #include <err.h>
  26 #endif
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <glob.h>
  30 #include <limits.h>
  31 #include <regex.h>
  32 #include <stdio.h>
  33 #include <stdint.h>
  34 #include <stddef.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38
  39 #include "mandoc_aux.h"
  40 #include "mandoc_ohash.h"
  41 #include "manconf.h"
  42 #include "mansearch.h"
  43 #include "dbm.h"
  44
  45 struct  expr {
  46         /* Used for terms: */
  47         struct dbm_match match;   /* Match type and expression. */
  48         uint64_t         bits;    /* Type mask. */
  49         /* Used for OR and AND groups: */
  50         struct expr     *next;    /* Next child in the parent group. */
  51         struct expr     *child;   /* First child in this group. */
  52         enum { EXPR_TERM, EXPR_OR, EXPR_AND } type;
  53 };
  54
  55 const char *const mansearch_keynames[KEY_MAX] = {
  56         "arch", "sec",  "Xr",   "Ar",   "Fa",   "Fl",   "Dv",   "Fn",
  57         "Ic",   "Pa",   "Cm",   "Li",   "Em",   "Cd",   "Va",   "Ft",
  58         "Tn",   "Er",   "Ev",   "Sy",   "Sh",   "In",   "Ss",   "Ox",
  59         "An",   "Mt",   "St",   "Bx",   "At",   "Nx",   "Fx",   "Lk",
  60         "Ms",   "Bsx",  "Dx",   "Rs",   "Vt",   "Lb",   "Nm",   "Nd"
  61 };
  62
  63
  64 static  struct ohash    *manmerge(struct expr *, struct ohash *);
  65 static  struct ohash    *manmerge_term(struct expr *, struct ohash *);
  66 static  struct ohash    *manmerge_or(struct expr *, struct ohash *);
  67 static  struct ohash    *manmerge_and(struct expr *, struct ohash *);
  68 static  char            *buildnames(const struct dbm_page *);
  69 static  char            *buildoutput(size_t, struct dbm_page *);
  70 static  size_t           lstlen(const char *, size_t);
  71 static  void             lstcat(char *, size_t *, const char *, const char *);
  72 static  int              lstmatch(const char *, const char *);
  73 static  struct expr     *exprcomp(const struct mansearch *,
  74                                 int, char *[], int *);
  75 static  struct expr     *expr_and(const struct mansearch *,
  76                                 int, char *[], int *);
  77 static  struct expr     *exprterm(const struct mansearch *,
  78                                 int, char *[], int *);
  79 static  void             exprfree(struct expr *);
  80 static  int              manpage_compare(const void *, const void *);
  81
  82
  83 int
  84 mansearch(const struct mansearch *search,
  85                 const struct manpaths *paths,
  86                 int argc, char *argv[],
  87                 struct manpage **res, size_t *sz)
  88 {
  89         char             buf[PATH_MAX];
  90         struct dbm_res  *rp;
  91         struct expr     *e;
  92         struct dbm_page *page;
  93         struct manpage  *mpage;
  94         struct ohash    *htab;
  95         size_t           cur, i, maxres, outkey;
  96         unsigned int     slot;
  97         int              argi, chdir_status, getcwd_status, im;
  98
  99         argi = 0;
 100         if ((e = exprcomp(search, argc, argv, &argi)) == NULL) {
 101                 *sz = 0;
 102                 return 0;
 103         }
 104
 105         cur = maxres = 0;
 106         if (res != NULL)
 107                 *res = NULL;
 108
 109         outkey = KEY_Nd;
 110         if (search->outkey != NULL)
 111                 for (im = 0; im < KEY_MAX; im++)
 112                         if (0 == strcasecmp(search->outkey,
 113                             mansearch_keynames[im])) {
 114                                 outkey = im;
 115                                 break;
 116                         }
 117
 118         /*
 119          * Remember the original working directory, if possible.
 120          * This will be needed if the second or a later directory
 121          * is given as a relative path.
 122          * Do not error out if the current directory is not
 123          * searchable: Maybe it won't be needed after all.
 124          */
 125
 126         if (getcwd(buf, PATH_MAX) == NULL) {
 127                 getcwd_status = 0;
 128                 (void)strlcpy(buf, strerror(errno), sizeof(buf));
 129         } else
 130                 getcwd_status = 1;
 131
 132         /*
 133          * Loop over the directories (containing databases) for us to
 134          * search.
 135          * Don't let missing/bad databases/directories phase us.
 136          * In each, try to open the resident database and, if it opens,
 137          * scan it for our match expression.
 138          */
 139
 140         chdir_status = 0;
 141         for (i = 0; i < paths->sz; i++) {
 142                 if (chdir_status && paths->paths[i][0] != '/') {
 143                         if ( ! getcwd_status) {
 144                                 warnx("%s: getcwd: %s", paths->paths[i], buf);
 145                                 continue;
 146                         } else if (chdir(buf) == -1) {
 147                                 warn("%s", buf);
 148                                 continue;
 149                         }
 150                 }
 151                 if (chdir(paths->paths[i]) == -1) {
 152                         warn("%s", paths->paths[i]);
 153                         continue;
 154                 }
 155                 chdir_status = 1;
 156
 157                 if (dbm_open(MANDOC_DB) == -1) {
 158                         if (errno != ENOENT)
 159                                 warn("%s/%s", paths->paths[i], MANDOC_DB);
 160                         continue;
 161                 }
 162
 163                 if ((htab = manmerge(e, NULL)) == NULL) {
 164                         dbm_close();
 165                         continue;
 166                 }
 167
 168                 for (rp = ohash_first(htab, &slot); rp != NULL;
 169                     rp = ohash_next(htab, &slot)) {
 170                         page = dbm_page_get(rp->page);
 171
 172                         if (lstmatch(search->sec, page->sect) == 0 ||
 173                             lstmatch(search->arch, page->arch) == 0 ||
 174                             (search->argmode == ARG_NAME &&
 175                              rp->bits <= (int32_t)(NAME_SYN & NAME_MASK)))
 176                                 continue;
 177
 178                         if (res == NULL) {
 179                                 cur = 1;
 180                                 break;
 181                         }
 182                         if (cur + 1 > maxres) {
 183                                 maxres += 1024;
 184                                 *res = mandoc_reallocarray(*res,
 185                                     maxres, sizeof(**res));
 186                         }
 187                         mpage = *res + cur;
 188                         mandoc_asprintf(&mpage->file, "%s/%s",
 189                             paths->paths[i], page->file + 1);
 190                         if (access(chdir_status ? page->file + 1 :
 191                             mpage->file, R_OK) == -1) {
 192                                 warn("%s", mpage->file);
 193                                 warnx("outdated mandoc.db contains "
 194                                     "bogus %s entry, run makewhatis %s",
 195                                     page->file + 1, paths->paths[i]);
 196                                 free(mpage->file);
 197                                 free(rp);
 198                                 continue;
 199                         }
 200                         mpage->names = buildnames(page);
 201                         mpage->output = buildoutput(outkey, page);
 202                         mpage->bits = search->firstmatch ? rp->bits : 0;
 203                         mpage->ipath = i;
 204                         mpage->sec = *page->sect - '0';
 205                         if (mpage->sec < 0 || mpage->sec > 9)
 206                                 mpage->sec = 10;
 207                         mpage->form = *page->file;
 208                         free(rp);
 209                         cur++;
 210                 }
 211                 ohash_delete(htab);
 212                 free(htab);
 213                 dbm_close();
 214
 215                 /*
 216                  * In man(1) mode, prefer matches in earlier trees
 217                  * over matches in later trees.
 218                  */
 219
 220                 if (cur && search->firstmatch)
 221                         break;
 222         }
 223         if (res != NULL)
 224                 qsort(*res, cur, sizeof(struct manpage), manpage_compare);
 225         if (chdir_status && getcwd_status && chdir(buf) == -1)
 226                 warn("%s", buf);
 227         exprfree(e);
 228         *sz = cur;
 229         return res != NULL || cur;
 230 }
 231
 232 /*
 233  * Merge the results for the expression tree rooted at e
 234  * into the the result list htab.
 235  */
 236 static struct ohash *
 237 manmerge(struct expr *e, struct ohash *htab)
 238 {
 239         switch (e->type) {
 240         case EXPR_TERM:
 241                 return manmerge_term(e, htab);
 242         case EXPR_OR:
 243                 return manmerge_or(e->child, htab);
 244         case EXPR_AND:
 245                 return manmerge_and(e->child, htab);
 246         default:
 247                 abort();
 248         }
 249 }
 250
 251 static struct ohash *
 252 manmerge_term(struct expr *e, struct ohash *htab)
 253 {
 254         struct dbm_res   res, *rp;
 255         uint64_t         ib;
 256         unsigned int     slot;
 257         int              im;
 258
 259         if (htab == NULL) {
 260                 htab = mandoc_malloc(sizeof(*htab));
 261                 mandoc_ohash_init(htab, 4, offsetof(struct dbm_res, page));
 262         }
 263
 264         for (im = 0, ib = 1; im < KEY_MAX; im++, ib <<= 1) {
 265                 if ((e->bits & ib) == 0)
 266                         continue;
 267
 268                 switch (ib) {
 269                 case TYPE_arch:
 270                         dbm_page_byarch(&e->match);
 271                         break;
 272                 case TYPE_sec:
 273                         dbm_page_bysect(&e->match);
 274                         break;
 275                 case TYPE_Nm:
 276                         dbm_page_byname(&e->match);
 277                         break;
 278                 case TYPE_Nd:
 279                         dbm_page_bydesc(&e->match);
 280                         break;
 281                 default:
 282                         dbm_page_bymacro(im - 2, &e->match);
 283                         break;
 284                 }
 285
 286                 /*
 287                  * When hashing for deduplication, use the unique
 288                  * page ID itself instead of a hash function;
 289                  * that is quite efficient.
 290                  */
 291
 292                 for (;;) {
 293                         res = dbm_page_next();
 294                         if (res.page == -1)
 295                                 break;
 296                         slot = ohash_lookup_memory(htab,
 297                             (char *)&res, sizeof(res.page), res.page);
 298                         if ((rp = ohash_find(htab, slot)) != NULL) {
 299                                 rp->bits |= res.bits;
 300                                 continue;
 301                         }
 302                         rp = mandoc_malloc(sizeof(*rp));
 303                         *rp = res;
 304                         ohash_insert(htab, slot, rp);
 305                 }
 306         }
 307         return htab;
 308 }
 309
 310 static struct ohash *
 311 manmerge_or(struct expr *e, struct ohash *htab)
 312 {
 313         while (e != NULL) {
 314                 htab = manmerge(e, htab);
 315                 e = e->next;
 316         }
 317         return htab;
 318 }
 319
 320 static struct ohash *
 321 manmerge_and(struct expr *e, struct ohash *htab)
 322 {
 323         struct ohash    *hand, *h1, *h2;
 324         struct dbm_res  *res;
 325         unsigned int     slot1, slot2;
 326
 327         /* Evaluate the first term of the AND clause. */
 328
 329         hand = manmerge(e, NULL);
 330
 331         while ((e = e->next) != NULL) {
 332
 333                 /* Evaluate the next term and prepare for ANDing. */
 334
 335                 h2 = manmerge(e, NULL);
 336                 if (ohash_entries(h2) < ohash_entries(hand)) {
 337                         h1 = h2;
 338                         h2 = hand;
 339                 } else
 340                         h1 = hand;
 341                 hand = mandoc_malloc(sizeof(*hand));
 342                 mandoc_ohash_init(hand, 4, offsetof(struct dbm_res, page));
 343
 344                 /* Keep all pages that are in both result sets. */
 345
 346                 for (res = ohash_first(h1, &slot1); res != NULL;
 347                     res = ohash_next(h1, &slot1)) {
 348                         if (ohash_find(h2, ohash_lookup_memory(h2,
 349                             (char *)res, sizeof(res->page),
 350                             res->page)) == NULL)
 351                                 free(res);
 352                         else
 353                                 ohash_insert(hand, ohash_lookup_memory(hand,
 354                                     (char *)res, sizeof(res->page),
 355                                     res->page), res);
 356                 }
 357
 358                 /* Discard the merged results. */
 359
 360                 for (res = ohash_first(h2, &slot2); res != NULL;
 361                     res = ohash_next(h2, &slot2))
 362                         free(res);
 363                 ohash_delete(h2);
 364                 free(h2);
 365                 ohash_delete(h1);
 366                 free(h1);
 367         }
 368
 369         /* Merge the result of the AND into htab. */
 370
 371         if (htab == NULL)
 372                 return hand;
 373
 374         for (res = ohash_first(hand, &slot1); res != NULL;
 375             res = ohash_next(hand, &slot1)) {
 376                 slot2 = ohash_lookup_memory(htab,
 377                     (char *)res, sizeof(res->page), res->page);
 378                 if (ohash_find(htab, slot2) == NULL)
 379                         ohash_insert(htab, slot2, res);
 380                 else
 381                         free(res);
 382         }
 383
 384         /* Discard the merged result. */
 385
 386         ohash_delete(hand);
 387         free(hand);
 388         return htab;
 389 }
 390
 391 void
 392 mansearch_free(struct manpage *res, size_t sz)
 393 {
 394         size_t   i;
 395
 396         for (i = 0; i < sz; i++) {
 397                 free(res[i].file);
 398                 free(res[i].names);
 399                 free(res[i].output);
 400         }
 401         free(res);
 402 }
 403
 404 static int
 405 manpage_compare(const void *vp1, const void *vp2)
 406 {
 407         const struct manpage    *mp1, *mp2;
 408         const char              *cp1, *cp2;
 409         size_t                   sz1, sz2;
 410         int                      diff;
 411
 412         mp1 = vp1;
 413         mp2 = vp2;
 414         if ((diff = mp2->bits - mp1->bits) ||
 415             (diff = mp1->sec - mp2->sec))
 416                 return diff;
 417
 418         /* Fall back to alphabetic ordering of names. */
 419         sz1 = strcspn(mp1->names, "(");
 420         sz2 = strcspn(mp2->names, "(");
 421         if (sz1 < sz2)
 422                 sz1 = sz2;
 423         if ((diff = strncasecmp(mp1->names, mp2->names, sz1)))
 424                 return diff;
 425
 426         /* For identical names and sections, prefer arch-dependent. */
 427         cp1 = strchr(mp1->names + sz1, '/');
 428         cp2 = strchr(mp2->names + sz2, '/');
 429         return cp1 != NULL && cp2 != NULL ? strcasecmp(cp1, cp2) :
 430             cp1 != NULL ? -1 : cp2 != NULL ? 1 : 0;
 431 }
 432
 433 static char *
 434 buildnames(const struct dbm_page *page)
 435 {
 436         char    *buf;
 437         size_t   i, sz;
 438
 439         sz = lstlen(page->name, 2) + 1 + lstlen(page->sect, 2) +
 440             (page->arch == NULL ? 0 : 1 + lstlen(page->arch, 2)) + 2;
 441         buf = mandoc_malloc(sz);
 442         i = 0;
 443         lstcat(buf, &i, page->name, ", ");
 444         buf[i++] = '(';
 445         lstcat(buf, &i, page->sect, ", ");
 446         if (page->arch != NULL) {
 447                 buf[i++] = '/';
 448                 lstcat(buf, &i, page->arch, ", ");
 449         }
 450         buf[i++] = ')';
 451         buf[i++] = '\0';
 452         assert(i == sz);
 453         return buf;
 454 }
 455
 456 /*
 457  * Count the buffer space needed to print the NUL-terminated
 458  * list of NUL-terminated strings, when printing sep separator
 459  * characters between strings.
 460  */
 461 static size_t
 462 lstlen(const char *cp, size_t sep)
 463 {
 464         size_t   sz;
 465
 466         for (sz = 0; *cp != '\0'; cp++) {
 467
 468                 /* Skip names appearing only in the SYNOPSIS. */
 469                 if (*cp <= (char)(NAME_SYN & NAME_MASK)) {
 470                         while (*cp != '\0')
 471                                 cp++;
 472                         continue;
 473                 }
 474
 475                 /* Skip name class markers. */
 476                 if (*cp < ' ')
 477                         cp++;
 478
 479                 /* Print a separator before each but the first string. */
 480                 if (sz)
 481                         sz += sep;
 482
 483                 /* Copy one string. */
 484                 while (*cp != '\0') {
 485                         sz++;
 486                         cp++;
 487                 }
 488         }
 489         return sz;
 490 }
 491
 492 /*
 493  * Print the NUL-terminated list of NUL-terminated strings
 494  * into the buffer, seperating strings with sep.
 495  */
 496 static void
 497 lstcat(char *buf, size_t *i, const char *cp, const char *sep)
 498 {
 499         const char      *s;
 500         size_t           i_start;
 501
 502         for (i_start = *i; *cp != '\0'; cp++) {
 503
 504                 /* Skip names appearing only in the SYNOPSIS. */
 505                 if (*cp <= (char)(NAME_SYN & NAME_MASK)) {
 506                         while (*cp != '\0')
 507                                 cp++;
 508                         continue;
 509                 }
 510
 511                 /* Skip name class markers. */
 512                 if (*cp < ' ')
 513                         cp++;
 514
 515                 /* Print a separator before each but the first string. */
 516                 if (*i > i_start) {
 517                         s = sep;
 518                         while (*s != '\0')
 519                                 buf[(*i)++] = *s++;
 520                 }
 521
 522                 /* Copy one string. */
 523                 while (*cp != '\0')
 524                         buf[(*i)++] = *cp++;
 525         }
 526
 527 }
 528
 529 /*
 530  * Return 1 if the string *want occurs in any of the strings
 531  * in the NUL-terminated string list *have, or 0 otherwise.
 532  * If either argument is NULL or empty, assume no filtering
 533  * is desired and return 1.
 534  */
 535 static int
 536 lstmatch(const char *want, const char *have)
 537 {
 538         if (want == NULL || have == NULL || *have == '\0')
 539                 return 1;
 540         while (*have != '\0') {
 541                 if (strcasestr(have, want) != NULL)
 542                         return 1;
 543                 have = strchr(have, '\0') + 1;
 544         }
 545         return 0;
 546 }
 547
 548 /*
 549  * Build a list of values taken by the macro im in the manual page.
 550  */
 551 static char *
 552 buildoutput(size_t im, struct dbm_page *page)
 553 {
 554         const char      *oldoutput, *sep, *input;
 555         char            *output, *newoutput, *value;
 556         size_t           sz, i;
 557
 558         switch (im) {
 559         case KEY_Nd:
 560                 return mandoc_strdup(page->desc);
 561         case KEY_Nm:
 562                 input = page->name;
 563                 break;
 564         case KEY_sec:
 565                 input = page->sect;
 566                 break;
 567         case KEY_arch:
 568                 input = page->arch;
 569                 if (input == NULL)
 570                         input = "all\0";
 571                 break;
 572         default:
 573                 input = NULL;
 574                 break;
 575         }
 576
 577         if (input != NULL) {
 578                 sz = lstlen(input, 3) + 1;
 579                 output = mandoc_malloc(sz);
 580                 i = 0;
 581                 lstcat(output, &i, input, " # ");
 582                 output[i++] = '\0';
 583                 assert(i == sz);
 584                 return output;
 585         }
 586
 587         output = NULL;
 588         dbm_macro_bypage(im - 2, page->addr);
 589         while ((value = dbm_macro_next()) != NULL) {
 590                 if (output == NULL) {
 591                         oldoutput = "";
 592                         sep = "";
 593                 } else {
 594                         oldoutput = output;
 595                         sep = " # ";
 596                 }
 597                 mandoc_asprintf(&newoutput, "%s%s%s", oldoutput, sep, value);
 598                 free(output);
 599                 output = newoutput;
 600         }
 601         return output;
 602 }
 603
 604 /*
 605  * Compile a set of string tokens into an expression.
 606  * Tokens in "argv" are assumed to be individual expression atoms (e.g.,
 607  * "(", "foo=bar", etc.).
 608  */
 609 static struct expr *
 610 exprcomp(const struct mansearch *search, int argc, char *argv[], int *argi)
 611 {
 612         struct expr     *parent, *child;
 613         int              needterm, nested;
 614
 615         if ((nested = *argi) == argc)
 616                 return NULL;
 617         needterm = 1;
 618         parent = child = NULL;
 619         while (*argi < argc) {
 620                 if (strcmp(")", argv[*argi]) == 0) {
 621                         if (needterm)
 622                                 warnx("missing term "
 623                                     "before closing parenthesis");
 624                         needterm = 0;
 625                         if (nested)
 626                                 break;
 627                         warnx("ignoring unmatched right parenthesis");
 628                         ++*argi;
 629                         continue;
 630                 }
 631                 if (strcmp("-o", argv[*argi]) == 0) {
 632                         if (needterm) {
 633                                 if (*argi > 0)
 634                                         warnx("ignoring -o after %s",
 635                                             argv[*argi - 1]);
 636                                 else
 637                                         warnx("ignoring initial -o");
 638                         }
 639                         needterm = 1;
 640                         ++*argi;
 641                         continue;
 642                 }
 643                 needterm = 0;
 644                 if (child == NULL) {
 645                         child = expr_and(search, argc, argv, argi);
 646                         continue;
 647                 }
 648                 if (parent == NULL) {
 649                         parent = mandoc_calloc(1, sizeof(*parent));
 650                         parent->type = EXPR_OR;
 651                         parent->next = NULL;
 652                         parent->child = child;
 653                 }
 654                 child->next = expr_and(search, argc, argv, argi);
 655                 child = child->next;
 656         }
 657         if (needterm && *argi)
 658                 warnx("ignoring trailing %s", argv[*argi - 1]);
 659         return parent == NULL ? child : parent;
 660 }
 661
 662 static struct expr *
 663 expr_and(const struct mansearch *search, int argc, char *argv[], int *argi)
 664 {
 665         struct expr     *parent, *child;
 666         int              needterm;
 667
 668         needterm = 1;
 669         parent = child = NULL;
 670         while (*argi < argc) {
 671                 if (strcmp(")", argv[*argi]) == 0) {
 672                         if (needterm)
 673                                 warnx("missing term "
 674                                     "before closing parenthesis");
 675                         needterm = 0;
 676                         break;
 677                 }
 678                 if (strcmp("-o", argv[*argi]) == 0)
 679                         break;
 680                 if (strcmp("-a", argv[*argi]) == 0) {
 681                         if (needterm) {
 682                                 if (*argi > 0)
 683                                         warnx("ignoring -a after %s",
 684                                             argv[*argi - 1]);
 685                                 else
 686                                         warnx("ignoring initial -a");
 687                         }
 688                         needterm = 1;
 689                         ++*argi;
 690                         continue;
 691                 }
 692                 if (needterm == 0)
 693                         break;
 694                 if (child == NULL) {
 695                         child = exprterm(search, argc, argv, argi);
 696                         if (child != NULL)
 697                                 needterm = 0;
 698                         continue;
 699                 }
 700                 needterm = 0;
 701                 if (parent == NULL) {
 702                         parent = mandoc_calloc(1, sizeof(*parent));
 703                         parent->type = EXPR_AND;
 704                         parent->next = NULL;
 705                         parent->child = child;
 706                 }
 707                 child->next = exprterm(search, argc, argv, argi);
 708                 if (child->next != NULL) {
 709                         child = child->next;
 710                         needterm = 0;
 711                 }
 712         }
 713         if (needterm && *argi)
 714                 warnx("ignoring trailing %s", argv[*argi - 1]);
 715         return parent == NULL ? child : parent;
 716 }
 717
 718 static struct expr *
 719 exprterm(const struct mansearch *search, int argc, char *argv[], int *argi)
 720 {
 721         char             errbuf[BUFSIZ];
 722         struct expr     *e;
 723         char            *key, *val;
 724         uint64_t         iterbit;
 725         int              cs, i, irc;
 726
 727         if (strcmp("(", argv[*argi]) == 0) {
 728                 ++*argi;
 729                 e = exprcomp(search, argc, argv, argi);
 730                 if (*argi < argc) {
 731                         assert(strcmp(")", argv[*argi]) == 0);
 732                         ++*argi;
 733                 } else
 734                         warnx("unclosed parenthesis");
 735                 return e;
 736         }
 737
 738         if (strcmp("-i", argv[*argi]) == 0 && *argi + 1 < argc) {
 739                 cs = 0;
 740                 ++*argi;
 741         } else
 742                 cs = 1;
 743
 744         e = mandoc_calloc(1, sizeof(*e));
 745         e->type = EXPR_TERM;
 746         e->bits = 0;
 747         e->next = NULL;
 748         e->child = NULL;
 749
 750         if (search->argmode == ARG_NAME) {
 751                 e->bits = TYPE_Nm;
 752                 e->match.type = DBM_EXACT;
 753                 e->match.str = argv[(*argi)++];
 754                 return e;
 755         }
 756
 757         /*
 758          * Separate macro keys from search string.
 759          * If needed, request regular expression handling.
 760          */
 761
 762         if (search->argmode == ARG_WORD) {
 763                 e->bits = TYPE_Nm;
 764                 e->match.type = DBM_REGEX;
 765 #if HAVE_REWB_BSD
 766                 mandoc_asprintf(&val, "[[:<:]]%s[[:>:]]", argv[*argi]);
 767 #elif HAVE_REWB_SYSV
 768                 mandoc_asprintf(&val, "\\<%s\\>", argv[*argi]);
 769 #else
 770                 mandoc_asprintf(&val,
 771                     "(^|[^a-zA-Z01-9_])%s([^a-zA-Z01-9_]|$)", argv[*argi]);
 772 #endif
 773                 cs = 0;
 774         } else if ((val = strpbrk(argv[*argi], "=~")) == NULL) {
 775                 e->bits = TYPE_Nm | TYPE_Nd;
 776                 e->match.type = DBM_REGEX;
 777                 val = argv[*argi];
 778                 cs = 0;
 779         } else {
 780                 if (val == argv[*argi])
 781                         e->bits = TYPE_Nm | TYPE_Nd;
 782                 if (*val == '=') {
 783                         e->match.type = DBM_SUB;
 784                         e->match.str = val + 1;
 785                 } else
 786                         e->match.type = DBM_REGEX;
 787                 *val++ = '\0';
 788                 if (strstr(argv[*argi], "arch") != NULL)
 789                         cs = 0;
 790         }
 791
 792         /* Compile regular expressions. */
 793
 794         if (e->match.type == DBM_REGEX) {
 795                 e->match.re = mandoc_malloc(sizeof(*e->match.re));
 796                 irc = regcomp(e->match.re, val,
 797                     REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE));
 798                 if (irc) {
 799                         regerror(irc, e->match.re, errbuf, sizeof(errbuf));
 800                         warnx("regcomp /%s/: %s", val, errbuf);
 801                 }
 802                 if (search->argmode == ARG_WORD)
 803                         free(val);
 804                 if (irc) {
 805                         free(e->match.re);
 806                         free(e);
 807                         ++*argi;
 808                         return NULL;
 809                 }
 810         }
 811
 812         if (e->bits) {
 813                 ++*argi;
 814                 return e;
 815         }
 816
 817         /*
 818          * Parse out all possible fields.
 819          * If the field doesn't resolve, bail.
 820          */
 821
 822         while (NULL != (key = strsep(&argv[*argi], ","))) {
 823                 if ('\0' == *key)
 824                         continue;
 825                 for (i = 0, iterbit = 1; i < KEY_MAX; i++, iterbit <<= 1) {
 826                         if (0 == strcasecmp(key, mansearch_keynames[i])) {
 827                                 e->bits |= iterbit;
 828                                 break;
 829                         }
 830                 }
 831                 if (i == KEY_MAX) {
 832                         if (strcasecmp(key, "any"))
 833                                 warnx("treating unknown key "
 834                                     "\"%s\" as \"any\"", key);
 835                         e->bits |= ~0ULL;
 836                 }
 837         }
 838
 839         ++*argi;
 840         return e;
 841 }
 842
 843 static void
 844 exprfree(struct expr *e)
 845 {
 846         if (e->next != NULL)
 847                 exprfree(e->next);
 848         if (e->child != NULL)
 849                 exprfree(e->child);
 850         free(e);
 851 }