xref: /illumos-gate/usr/src/cmd/mandoc/mandocdb.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /* $Id: mandocdb.c,v 1.269 2021/08/19 16:55:31 schwarze Exp $ */
2 /*
3  * Copyright (c) 2011-2020 Ingo Schwarze <schwarze@openbsd.org>
4  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
5  * Copyright (c) 2016 Ed Maste <emaste@freebsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  *
19  * Implementation of the makewhatis(8) program.
20  */
21 #include "config.h"
22 
23 #include <sys/types.h>
24 #include <sys/mman.h>
25 #include <sys/stat.h>
26 
27 #include <assert.h>
28 #include <ctype.h>
29 #if HAVE_ERR
30 #include <err.h>
31 #endif
32 #include <errno.h>
33 #include <fcntl.h>
34 #if HAVE_FTS
35 #include <fts.h>
36 #else
37 #include "compat_fts.h"
38 #endif
39 #include <limits.h>
40 #if HAVE_SANDBOX_INIT
41 #include <sandbox.h>
42 #endif
43 #include <stdarg.h>
44 #include <stddef.h>
45 #include <stdio.h>
46 #include <stdint.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "mandoc_aux.h"
52 #include "mandoc_ohash.h"
53 #include "mandoc.h"
54 #include "roff.h"
55 #include "mdoc.h"
56 #include "man.h"
57 #include "mandoc_parse.h"
58 #include "manconf.h"
59 #include "mansearch.h"
60 #include "dba_array.h"
61 #include "dba.h"
62 
63 extern const char *const mansearch_keynames[];
64 
65 enum	op {
66 	OP_DEFAULT = 0, /* new dbs from dir list or default config */
67 	OP_CONFFILE, /* new databases from custom config file */
68 	OP_UPDATE, /* delete/add entries in existing database */
69 	OP_DELETE, /* delete entries from existing database */
70 	OP_TEST /* change no databases, report potential problems */
71 };
72 
73 struct	str {
74 	const struct mpage *mpage; /* if set, the owning parse */
75 	uint64_t	 mask; /* bitmask in sequence */
76 	char		 key[]; /* rendered text */
77 };
78 
79 struct	inodev {
80 	ino_t		 st_ino;
81 	dev_t		 st_dev;
82 };
83 
84 struct	mpage {
85 	struct inodev	 inodev;  /* used for hashing routine */
86 	struct dba_array *dba;
87 	char		*sec;     /* section from file content */
88 	char		*arch;    /* architecture from file content */
89 	char		*title;   /* title from file content */
90 	char		*desc;    /* description from file content */
91 	struct mpage	*next;    /* singly linked list */
92 	struct mlink	*mlinks;  /* singly linked list */
93 	int		 name_head_done;
94 	enum form	 form;    /* format from file content */
95 };
96 
97 struct	mlink {
98 	char		 file[PATH_MAX]; /* filename rel. to manpath */
99 	char		*dsec;    /* section from directory */
100 	char		*arch;    /* architecture from directory */
101 	char		*name;    /* name from file name (not empty) */
102 	char		*fsec;    /* section from file name suffix */
103 	struct mlink	*next;    /* singly linked list */
104 	struct mpage	*mpage;   /* parent */
105 	int		 gzip;	  /* filename has a .gz suffix */
106 	enum form	 dform;   /* format from directory */
107 	enum form	 fform;   /* format from file name suffix */
108 };
109 
110 typedef	int (*mdoc_fp)(struct mpage *, const struct roff_meta *,
111 			const struct roff_node *);
112 
113 struct	mdoc_handler {
114 	mdoc_fp		 fp; /* optional handler */
115 	uint64_t	 mask;  /* set unless handler returns 0 */
116 	int		 taboo;  /* node flags that must not be set */
117 };
118 
119 
120 int		 mandocdb(int, char *[]);
121 
122 static	void	 dbadd(struct dba *, struct mpage *);
123 static	void	 dbadd_mlink(const struct mlink *);
124 static	void	 dbprune(struct dba *);
125 static	void	 dbwrite(struct dba *);
126 static	void	 filescan(const char *);
127 #if HAVE_FTS_COMPARE_CONST
128 static	int	 fts_compare(const FTSENT *const *, const FTSENT *const *);
129 #else
130 static	int	 fts_compare(const FTSENT **, const FTSENT **);
131 #endif
132 static	void	 mlink_add(struct mlink *, const struct stat *);
133 static	void	 mlink_check(struct mpage *, struct mlink *);
134 static	void	 mlink_free(struct mlink *);
135 static	void	 mlinks_undupe(struct mpage *);
136 static	void	 mpages_free(void);
137 static	void	 mpages_merge(struct dba *, struct mparse *);
138 static	void	 parse_cat(struct mpage *, int);
139 static	void	 parse_man(struct mpage *, const struct roff_meta *,
140 			const struct roff_node *);
141 static	void	 parse_mdoc(struct mpage *, const struct roff_meta *,
142 			const struct roff_node *);
143 static	int	 parse_mdoc_head(struct mpage *, const struct roff_meta *,
144 			const struct roff_node *);
145 static	int	 parse_mdoc_Fa(struct mpage *, const struct roff_meta *,
146 			const struct roff_node *);
147 static	int	 parse_mdoc_Fd(struct mpage *, const struct roff_meta *,
148 			const struct roff_node *);
149 static	void	 parse_mdoc_fname(struct mpage *, const struct roff_node *);
150 static	int	 parse_mdoc_Fn(struct mpage *, const struct roff_meta *,
151 			const struct roff_node *);
152 static	int	 parse_mdoc_Fo(struct mpage *, const struct roff_meta *,
153 			const struct roff_node *);
154 static	int	 parse_mdoc_Nd(struct mpage *, const struct roff_meta *,
155 			const struct roff_node *);
156 static	int	 parse_mdoc_Nm(struct mpage *, const struct roff_meta *,
157 			const struct roff_node *);
158 static	int	 parse_mdoc_Sh(struct mpage *, const struct roff_meta *,
159 			const struct roff_node *);
160 static	int	 parse_mdoc_Va(struct mpage *, const struct roff_meta *,
161 			const struct roff_node *);
162 static	int	 parse_mdoc_Xr(struct mpage *, const struct roff_meta *,
163 			const struct roff_node *);
164 static	void	 putkey(const struct mpage *, char *, uint64_t);
165 static	void	 putkeys(const struct mpage *, char *, size_t, uint64_t);
166 static	void	 putmdockey(const struct mpage *,
167 			const struct roff_node *, uint64_t, int);
168 #ifdef READ_ALLOWED_PATH
169 static	int	 read_allowed(const char *);
170 #endif
171 static	int	 render_string(char **, size_t *);
172 static	void	 say(const char *, const char *, ...)
173 			__attribute__((__format__ (__printf__, 2, 3)));
174 static	int	 set_basedir(const char *, int);
175 static	int	 treescan(void);
176 static	size_t	 utf8(unsigned int, char [7]);
177 
178 static	int		 nodb; /* no database changes */
179 static	int		 mparse_options; /* abort the parse early */
180 static	int		 use_all; /* use all found files */
181 static	int		 debug; /* print what we're doing */
182 static	int		 warnings; /* warn about crap */
183 static	int		 write_utf8; /* write UTF-8 output; else ASCII */
184 static	int		 exitcode; /* to be returned by main */
185 static	enum op		 op; /* operational mode */
186 static	char		 basedir[PATH_MAX]; /* current base directory */
187 static	size_t		 basedir_len; /* strlen(basedir) */
188 static	struct mpage	*mpage_head; /* list of distinct manual pages */
189 static	struct ohash	 mpages; /* table of distinct manual pages */
190 static	struct ohash	 mlinks; /* table of directory entries */
191 static	struct ohash	 names; /* table of all names */
192 static	struct ohash	 strings; /* table of all strings */
193 static	uint64_t	 name_mask;
194 
195 static	const struct mdoc_handler mdoc_handlers[MDOC_MAX - MDOC_Dd] = {
196 	{ NULL, 0, NODE_NOPRT },  /* Dd */
197 	{ NULL, 0, NODE_NOPRT },  /* Dt */
198 	{ NULL, 0, NODE_NOPRT },  /* Os */
199 	{ parse_mdoc_Sh, TYPE_Sh, 0 }, /* Sh */
200 	{ parse_mdoc_head, TYPE_Ss, 0 }, /* Ss */
201 	{ NULL, 0, 0 },  /* Pp */
202 	{ NULL, 0, 0 },  /* D1 */
203 	{ NULL, 0, 0 },  /* Dl */
204 	{ NULL, 0, 0 },  /* Bd */
205 	{ NULL, 0, 0 },  /* Ed */
206 	{ NULL, 0, 0 },  /* Bl */
207 	{ NULL, 0, 0 },  /* El */
208 	{ NULL, 0, 0 },  /* It */
209 	{ NULL, 0, 0 },  /* Ad */
210 	{ NULL, TYPE_An, 0 },  /* An */
211 	{ NULL, 0, 0 },  /* Ap */
212 	{ NULL, TYPE_Ar, 0 },  /* Ar */
213 	{ NULL, TYPE_Cd, 0 },  /* Cd */
214 	{ NULL, TYPE_Cm, 0 },  /* Cm */
215 	{ NULL, TYPE_Dv, 0 },  /* Dv */
216 	{ NULL, TYPE_Er, 0 },  /* Er */
217 	{ NULL, TYPE_Ev, 0 },  /* Ev */
218 	{ NULL, 0, 0 },  /* Ex */
219 	{ parse_mdoc_Fa, 0, 0 },  /* Fa */
220 	{ parse_mdoc_Fd, 0, 0 },  /* Fd */
221 	{ NULL, TYPE_Fl, 0 },  /* Fl */
222 	{ parse_mdoc_Fn, 0, 0 },  /* Fn */
223 	{ NULL, TYPE_Ft | TYPE_Vt, 0 },  /* Ft */
224 	{ NULL, TYPE_Ic, 0 },  /* Ic */
225 	{ NULL, TYPE_In, 0 },  /* In */
226 	{ NULL, TYPE_Li, 0 },  /* Li */
227 	{ parse_mdoc_Nd, 0, 0 },  /* Nd */
228 	{ parse_mdoc_Nm, 0, 0 },  /* Nm */
229 	{ NULL, 0, 0 },  /* Op */
230 	{ NULL, 0, 0 },  /* Ot */
231 	{ NULL, TYPE_Pa, NODE_NOSRC },  /* Pa */
232 	{ NULL, 0, 0 },  /* Rv */
233 	{ NULL, TYPE_St, 0 },  /* St */
234 	{ parse_mdoc_Va, TYPE_Va, 0 },  /* Va */
235 	{ parse_mdoc_Va, TYPE_Vt, 0 },  /* Vt */
236 	{ parse_mdoc_Xr, 0, 0 },  /* Xr */
237 	{ NULL, 0, 0 },  /* %A */
238 	{ NULL, 0, 0 },  /* %B */
239 	{ NULL, 0, 0 },  /* %D */
240 	{ NULL, 0, 0 },  /* %I */
241 	{ NULL, 0, 0 },  /* %J */
242 	{ NULL, 0, 0 },  /* %N */
243 	{ NULL, 0, 0 },  /* %O */
244 	{ NULL, 0, 0 },  /* %P */
245 	{ NULL, 0, 0 },  /* %R */
246 	{ NULL, 0, 0 },  /* %T */
247 	{ NULL, 0, 0 },  /* %V */
248 	{ NULL, 0, 0 },  /* Ac */
249 	{ NULL, 0, 0 },  /* Ao */
250 	{ NULL, 0, 0 },  /* Aq */
251 	{ NULL, TYPE_At, 0 },  /* At */
252 	{ NULL, 0, 0 },  /* Bc */
253 	{ NULL, 0, 0 },  /* Bf */
254 	{ NULL, 0, 0 },  /* Bo */
255 	{ NULL, 0, 0 },  /* Bq */
256 	{ NULL, TYPE_Bsx, NODE_NOSRC },  /* Bsx */
257 	{ NULL, TYPE_Bx, NODE_NOSRC },  /* Bx */
258 	{ NULL, 0, 0 },  /* Db */
259 	{ NULL, 0, 0 },  /* Dc */
260 	{ NULL, 0, 0 },  /* Do */
261 	{ NULL, 0, 0 },  /* Dq */
262 	{ NULL, 0, 0 },  /* Ec */
263 	{ NULL, 0, 0 },  /* Ef */
264 	{ NULL, TYPE_Em, 0 },  /* Em */
265 	{ NULL, 0, 0 },  /* Eo */
266 	{ NULL, TYPE_Fx, NODE_NOSRC },  /* Fx */
267 	{ NULL, TYPE_Ms, 0 },  /* Ms */
268 	{ NULL, 0, 0 },  /* No */
269 	{ NULL, 0, 0 },  /* Ns */
270 	{ NULL, TYPE_Nx, NODE_NOSRC },  /* Nx */
271 	{ NULL, TYPE_Ox, NODE_NOSRC },  /* Ox */
272 	{ NULL, 0, 0 },  /* Pc */
273 	{ NULL, 0, 0 },  /* Pf */
274 	{ NULL, 0, 0 },  /* Po */
275 	{ NULL, 0, 0 },  /* Pq */
276 	{ NULL, 0, 0 },  /* Qc */
277 	{ NULL, 0, 0 },  /* Ql */
278 	{ NULL, 0, 0 },  /* Qo */
279 	{ NULL, 0, 0 },  /* Qq */
280 	{ NULL, 0, 0 },  /* Re */
281 	{ NULL, 0, 0 },  /* Rs */
282 	{ NULL, 0, 0 },  /* Sc */
283 	{ NULL, 0, 0 },  /* So */
284 	{ NULL, 0, 0 },  /* Sq */
285 	{ NULL, 0, 0 },  /* Sm */
286 	{ NULL, 0, 0 },  /* Sx */
287 	{ NULL, TYPE_Sy, 0 },  /* Sy */
288 	{ NULL, TYPE_Tn, 0 },  /* Tn */
289 	{ NULL, 0, NODE_NOSRC },  /* Ux */
290 	{ NULL, 0, 0 },  /* Xc */
291 	{ NULL, 0, 0 },  /* Xo */
292 	{ parse_mdoc_Fo, 0, 0 },  /* Fo */
293 	{ NULL, 0, 0 },  /* Fc */
294 	{ NULL, 0, 0 },  /* Oo */
295 	{ NULL, 0, 0 },  /* Oc */
296 	{ NULL, 0, 0 },  /* Bk */
297 	{ NULL, 0, 0 },  /* Ek */
298 	{ NULL, 0, 0 },  /* Bt */
299 	{ NULL, 0, 0 },  /* Hf */
300 	{ NULL, 0, 0 },  /* Fr */
301 	{ NULL, 0, 0 },  /* Ud */
302 	{ NULL, TYPE_Lb, NODE_NOSRC },  /* Lb */
303 	{ NULL, 0, 0 },  /* Lp */
304 	{ NULL, TYPE_Lk, 0 },  /* Lk */
305 	{ NULL, TYPE_Mt, NODE_NOSRC },  /* Mt */
306 	{ NULL, 0, 0 },  /* Brq */
307 	{ NULL, 0, 0 },  /* Bro */
308 	{ NULL, 0, 0 },  /* Brc */
309 	{ NULL, 0, 0 },  /* %C */
310 	{ NULL, 0, 0 },  /* Es */
311 	{ NULL, 0, 0 },  /* En */
312 	{ NULL, TYPE_Dx, NODE_NOSRC },  /* Dx */
313 	{ NULL, 0, 0 },  /* %Q */
314 	{ NULL, 0, 0 },  /* %U */
315 	{ NULL, 0, 0 },  /* Ta */
316 };
317 
318 
319 int
320 mandocdb(int argc, char *argv[])
321 {
322 	struct manconf	  conf;
323 	struct mparse	 *mp;
324 	struct dba	 *dba;
325 	const char	 *path_arg, *progname;
326 	size_t		  j, sz;
327 	int		  ch, i;
328 
329 #if HAVE_PLEDGE
330 	if (pledge("stdio rpath wpath cpath", NULL) == -1) {
331 		warn("pledge");
332 		return (int)MANDOCLEVEL_SYSERR;
333 	}
334 #endif
335 
336 #if HAVE_SANDBOX_INIT
337 	if (sandbox_init(kSBXProfileNoInternet, SANDBOX_NAMED, NULL) == -1) {
338 		warnx("sandbox_init");
339 		return (int)MANDOCLEVEL_SYSERR;
340 	}
341 #endif
342 
343 	memset(&conf, 0, sizeof(conf));
344 
345 	/*
346 	 * We accept a few different invocations.
347 	 * The CHECKOP macro makes sure that invocation styles don't
348 	 * clobber each other.
349 	 */
350 #define	CHECKOP(_op, _ch) do \
351 	if ((_op) != OP_DEFAULT) { \
352 		warnx("-%c: Conflicting option", (_ch)); \
353 		goto usage; \
354 	} while (/*CONSTCOND*/0)
355 
356 	mparse_options = MPARSE_VALIDATE;
357 	path_arg = NULL;
358 	op = OP_DEFAULT;
359 
360 	while ((ch = getopt(argc, argv, "aC:Dd:npQT:tu:v")) != -1)
361 		switch (ch) {
362 		case 'a':
363 			use_all = 1;
364 			break;
365 		case 'C':
366 			CHECKOP(op, ch);
367 			path_arg = optarg;
368 			op = OP_CONFFILE;
369 			break;
370 		case 'D':
371 			debug++;
372 			break;
373 		case 'd':
374 			CHECKOP(op, ch);
375 			path_arg = optarg;
376 			op = OP_UPDATE;
377 			break;
378 		case 'n':
379 			nodb = 1;
380 			break;
381 		case 'p':
382 			warnings = 1;
383 			break;
384 		case 'Q':
385 			mparse_options |= MPARSE_QUICK;
386 			break;
387 		case 'T':
388 			if (strcmp(optarg, "utf8") != 0) {
389 				warnx("-T%s: Unsupported output format",
390 				    optarg);
391 				goto usage;
392 			}
393 			write_utf8 = 1;
394 			break;
395 		case 't':
396 			CHECKOP(op, ch);
397 			dup2(STDOUT_FILENO, STDERR_FILENO);
398 			op = OP_TEST;
399 			nodb = warnings = 1;
400 			break;
401 		case 'u':
402 			CHECKOP(op, ch);
403 			path_arg = optarg;
404 			op = OP_DELETE;
405 			break;
406 		case 'v':
407 			/* Compatibility with espie@'s makewhatis. */
408 			break;
409 		default:
410 			goto usage;
411 		}
412 
413 	argc -= optind;
414 	argv += optind;
415 
416 #if HAVE_PLEDGE
417 	if (nodb) {
418 		if (pledge("stdio rpath", NULL) == -1) {
419 			warn("pledge");
420 			return (int)MANDOCLEVEL_SYSERR;
421 		}
422 	}
423 #endif
424 
425 	if (op == OP_CONFFILE && argc > 0) {
426 		warnx("-C: Too many arguments");
427 		goto usage;
428 	}
429 
430 	exitcode = (int)MANDOCLEVEL_OK;
431 	mchars_alloc();
432 	mp = mparse_alloc(mparse_options, MANDOC_OS_OTHER, NULL);
433 	mandoc_ohash_init(&mpages, 6, offsetof(struct mpage, inodev));
434 	mandoc_ohash_init(&mlinks, 6, offsetof(struct mlink, file));
435 
436 	if (op == OP_UPDATE || op == OP_DELETE || op == OP_TEST) {
437 
438 		/*
439 		 * Most of these deal with a specific directory.
440 		 * Jump into that directory first.
441 		 */
442 		if (op != OP_TEST && set_basedir(path_arg, 1) == 0)
443 			goto out;
444 
445 		dba = nodb ? dba_new(128) : dba_read(MANDOC_DB);
446 		if (dba != NULL) {
447 			/*
448 			 * The existing database is usable.  Process
449 			 * all files specified on the command-line.
450 			 */
451 			use_all = 1;
452 			for (i = 0; i < argc; i++)
453 				filescan(argv[i]);
454 			if (nodb == 0)
455 				dbprune(dba);
456 		} else {
457 			/* Database missing or corrupt. */
458 			if (op != OP_UPDATE || errno != ENOENT)
459 				say(MANDOC_DB, "%s: Automatically recreating"
460 				    " from scratch", strerror(errno));
461 			exitcode = (int)MANDOCLEVEL_OK;
462 			op = OP_DEFAULT;
463 			if (treescan() == 0)
464 				goto out;
465 			dba = dba_new(128);
466 		}
467 		if (op != OP_DELETE)
468 			mpages_merge(dba, mp);
469 		if (nodb == 0)
470 			dbwrite(dba);
471 		dba_free(dba);
472 	} else {
473 		/*
474 		 * If we have arguments, use them as our manpaths.
475 		 * If we don't, use man.conf(5).
476 		 */
477 		if (argc > 0) {
478 			conf.manpath.paths = mandoc_reallocarray(NULL,
479 			    argc, sizeof(char *));
480 			conf.manpath.sz = (size_t)argc;
481 			for (i = 0; i < argc; i++)
482 				conf.manpath.paths[i] = mandoc_strdup(argv[i]);
483 		} else
484 			manconf_parse(&conf, path_arg, NULL, NULL);
485 
486 		if (conf.manpath.sz == 0) {
487 			exitcode = (int)MANDOCLEVEL_BADARG;
488 			say("", "Empty manpath");
489 		}
490 
491 		/*
492 		 * First scan the tree rooted at a base directory, then
493 		 * build a new database and finally move it into place.
494 		 * Ignore zero-length directories and strip trailing
495 		 * slashes.
496 		 */
497 		for (j = 0; j < conf.manpath.sz; j++) {
498 			sz = strlen(conf.manpath.paths[j]);
499 			if (sz && conf.manpath.paths[j][sz - 1] == '/')
500 				conf.manpath.paths[j][--sz] = '\0';
501 			if (sz == 0)
502 				continue;
503 
504 			if (j) {
505 				mandoc_ohash_init(&mpages, 6,
506 				    offsetof(struct mpage, inodev));
507 				mandoc_ohash_init(&mlinks, 6,
508 				    offsetof(struct mlink, file));
509 			}
510 
511 			if (set_basedir(conf.manpath.paths[j], argc > 0) == 0)
512 				continue;
513 			if (treescan() == 0)
514 				continue;
515 			dba = dba_new(128);
516 			mpages_merge(dba, mp);
517 			if (nodb == 0)
518 				dbwrite(dba);
519 			dba_free(dba);
520 
521 			if (j + 1 < conf.manpath.sz) {
522 				mpages_free();
523 				ohash_delete(&mpages);
524 				ohash_delete(&mlinks);
525 			}
526 		}
527 	}
528 out:
529 	manconf_free(&conf);
530 	mparse_free(mp);
531 	mchars_free();
532 	mpages_free();
533 	ohash_delete(&mpages);
534 	ohash_delete(&mlinks);
535 	return exitcode;
536 usage:
537 	progname = getprogname();
538 	fprintf(stderr, "usage: %s [-aDnpQ] [-C file] [-Tutf8]\n"
539 			"       %s [-aDnpQ] [-Tutf8] dir ...\n"
540 			"       %s [-DnpQ] [-Tutf8] -d dir [file ...]\n"
541 			"       %s [-Dnp] -u dir [file ...]\n"
542 			"       %s [-Q] -t file ...\n",
543 		        progname, progname, progname, progname, progname);
544 
545 	return (int)MANDOCLEVEL_BADARG;
546 }
547 
548 /*
549  * To get a singly linked list in alpha order while inserting entries
550  * at the beginning, process directory entries in reverse alpha order.
551  */
552 static int
553 #if HAVE_FTS_COMPARE_CONST
554 fts_compare(const FTSENT *const *a, const FTSENT *const *b)
555 #else
556 fts_compare(const FTSENT **a, const FTSENT **b)
557 #endif
558 {
559 	return -strcmp((*a)->fts_name, (*b)->fts_name);
560 }
561 
562 /*
563  * Scan a directory tree rooted at "basedir" for manpages.
564  * We use fts(), scanning directory parts along the way for clues to our
565  * section and architecture.
566  *
567  * If use_all has been specified, grok all files.
568  * If not, sanitise paths to the following:
569  *
570  *   [./]man*[/<arch>]/<name>.<section>
571  *   or
572  *   [./]cat<section>[/<arch>]/<name>.0
573  *
574  * TODO: accommodate for multi-language directories.
575  */
576 static int
577 treescan(void)
578 {
579 	char		 buf[PATH_MAX];
580 	FTS		*f;
581 	FTSENT		*ff;
582 	struct mlink	*mlink;
583 	int		 gzip;
584 	enum form	 dform;
585 	char		*dsec, *arch, *fsec, *cp;
586 	const char	*path;
587 	const char	*argv[2];
588 
589 	argv[0] = ".";
590 	argv[1] = NULL;
591 
592 	f = fts_open((char * const *)argv, FTS_PHYSICAL | FTS_NOCHDIR,
593 	    fts_compare);
594 	if (f == NULL) {
595 		exitcode = (int)MANDOCLEVEL_SYSERR;
596 		say("", "&fts_open");
597 		return 0;
598 	}
599 
600 	dsec = arch = NULL;
601 	dform = FORM_NONE;
602 
603 	while ((ff = fts_read(f)) != NULL) {
604 		path = ff->fts_path + 2;
605 		switch (ff->fts_info) {
606 
607 		/*
608 		 * Symbolic links require various sanity checks,
609 		 * then get handled just like regular files.
610 		 */
611 		case FTS_SL:
612 			if (realpath(path, buf) == NULL) {
613 				if (warnings)
614 					say(path, "&realpath");
615 				continue;
616 			}
617 			if (strncmp(buf, basedir, basedir_len) != 0
618 #ifdef READ_ALLOWED_PATH
619 			    && !read_allowed(buf)
620 #endif
621 			) {
622 				if (warnings) say("",
623 				    "%s: outside base directory", buf);
624 				continue;
625 			}
626 			/* Use logical inode to avoid mpages dupe. */
627 			if (stat(path, ff->fts_statp) == -1) {
628 				if (warnings)
629 					say(path, "&stat");
630 				continue;
631 			}
632 			if ((ff->fts_statp->st_mode & S_IFMT) != S_IFREG)
633 				continue;
634 			/* FALLTHROUGH */
635 
636 		/*
637 		 * If we're a regular file, add an mlink by using the
638 		 * stored directory data and handling the filename.
639 		 */
640 		case FTS_F:
641 			if ( ! strcmp(path, MANDOC_DB))
642 				continue;
643 			if ( ! use_all && ff->fts_level < 2) {
644 				if (warnings)
645 					say(path, "Extraneous file");
646 				continue;
647 			}
648 			gzip = 0;
649 			fsec = NULL;
650 			while (fsec == NULL) {
651 				fsec = strrchr(ff->fts_name, '.');
652 				if (fsec == NULL || strcmp(fsec+1, "gz"))
653 					break;
654 				gzip = 1;
655 				*fsec = '\0';
656 				fsec = NULL;
657 			}
658 			if (fsec == NULL) {
659 				if ( ! use_all) {
660 					if (warnings)
661 						say(path,
662 						    "No filename suffix");
663 					continue;
664 				}
665 			} else if ( ! strcmp(++fsec, "html")) {
666 				if (warnings)
667 					say(path, "Skip html");
668 				continue;
669 			} else if ( ! strcmp(fsec, "ps")) {
670 				if (warnings)
671 					say(path, "Skip ps");
672 				continue;
673 			} else if ( ! strcmp(fsec, "pdf")) {
674 				if (warnings)
675 					say(path, "Skip pdf");
676 				continue;
677 			} else if ( ! use_all &&
678 			    ((dform == FORM_SRC &&
679 			      strncmp(fsec, dsec, strlen(dsec))) ||
680 			     (dform == FORM_CAT && strcmp(fsec, "0")))) {
681 				if (warnings)
682 					say(path, "Wrong filename suffix");
683 				continue;
684 			} else
685 				fsec[-1] = '\0';
686 
687 			mlink = mandoc_calloc(1, sizeof(struct mlink));
688 			if (strlcpy(mlink->file, path,
689 			    sizeof(mlink->file)) >=
690 			    sizeof(mlink->file)) {
691 				say(path, "Filename too long");
692 				free(mlink);
693 				continue;
694 			}
695 			mlink->dform = dform;
696 			mlink->dsec = dsec;
697 			mlink->arch = arch;
698 			mlink->name = ff->fts_name;
699 			mlink->fsec = fsec;
700 			mlink->gzip = gzip;
701 			mlink_add(mlink, ff->fts_statp);
702 			continue;
703 
704 		case FTS_D:
705 		case FTS_DP:
706 			break;
707 
708 		default:
709 			if (warnings)
710 				say(path, "Not a regular file");
711 			continue;
712 		}
713 
714 		switch (ff->fts_level) {
715 		case 0:
716 			/* Ignore the root directory. */
717 			break;
718 		case 1:
719 			/*
720 			 * This might contain manX/ or catX/.
721 			 * Try to infer this from the name.
722 			 * If we're not in use_all, enforce it.
723 			 */
724 			cp = ff->fts_name;
725 			if (ff->fts_info == FTS_DP) {
726 				dform = FORM_NONE;
727 				dsec = NULL;
728 				break;
729 			}
730 
731 			if ( ! strncmp(cp, "man", 3)) {
732 				dform = FORM_SRC;
733 				dsec = cp + 3;
734 			} else if ( ! strncmp(cp, "cat", 3)) {
735 				dform = FORM_CAT;
736 				dsec = cp + 3;
737 			} else {
738 				dform = FORM_NONE;
739 				dsec = NULL;
740 			}
741 
742 			if (dsec != NULL || use_all)
743 				break;
744 
745 			if (warnings)
746 				say(path, "Unknown directory part");
747 			fts_set(f, ff, FTS_SKIP);
748 			break;
749 		case 2:
750 			/*
751 			 * Possibly our architecture.
752 			 * If we're descending, keep tabs on it.
753 			 */
754 			if (ff->fts_info != FTS_DP && dsec != NULL)
755 				arch = ff->fts_name;
756 			else
757 				arch = NULL;
758 			break;
759 		default:
760 			if (ff->fts_info == FTS_DP || use_all)
761 				break;
762 			if (warnings)
763 				say(path, "Extraneous directory part");
764 			fts_set(f, ff, FTS_SKIP);
765 			break;
766 		}
767 	}
768 
769 	fts_close(f);
770 	return 1;
771 }
772 
773 /*
774  * Add a file to the mlinks table.
775  * Do not verify that it's a "valid" looking manpage (we'll do that
776  * later).
777  *
778  * Try to infer the manual section, architecture, and page name from the
779  * path, assuming it looks like
780  *
781  *   [./]man*[/<arch>]/<name>.<section>
782  *   or
783  *   [./]cat<section>[/<arch>]/<name>.0
784  *
785  * See treescan() for the fts(3) version of this.
786  */
787 static void
788 filescan(const char *infile)
789 {
790 	struct stat	 st;
791 	struct mlink	*mlink;
792 	char		*linkfile, *p, *realdir, *start, *usefile;
793 	size_t		 realdir_len;
794 
795 	assert(use_all);
796 
797 	if (strncmp(infile, "./", 2) == 0)
798 		infile += 2;
799 
800 	/*
801 	 * We have to do lstat(2) before realpath(3) loses
802 	 * the information whether this is a symbolic link.
803 	 * We need to know that because for symbolic links,
804 	 * we want to use the orginal file name, while for
805 	 * regular files, we want to use the real path.
806 	 */
807 	if (lstat(infile, &st) == -1) {
808 		exitcode = (int)MANDOCLEVEL_BADARG;
809 		say(infile, "&lstat");
810 		return;
811 	} else if (S_ISREG(st.st_mode) == 0 && S_ISLNK(st.st_mode) == 0) {
812 		exitcode = (int)MANDOCLEVEL_BADARG;
813 		say(infile, "Not a regular file");
814 		return;
815 	}
816 
817 	/*
818 	 * We have to resolve the file name to the real path
819 	 * in any case for the base directory check.
820 	 */
821 	if ((usefile = realpath(infile, NULL)) == NULL) {
822 		exitcode = (int)MANDOCLEVEL_BADARG;
823 		say(infile, "&realpath");
824 		return;
825 	}
826 
827 	if (op == OP_TEST)
828 		start = usefile;
829 	else if (strncmp(usefile, basedir, basedir_len) == 0)
830 		start = usefile + basedir_len;
831 #ifdef READ_ALLOWED_PATH
832 	else if (read_allowed(usefile))
833 		start = usefile;
834 #endif
835 	else {
836 		exitcode = (int)MANDOCLEVEL_BADARG;
837 		say("", "%s: outside base directory", infile);
838 		free(usefile);
839 		return;
840 	}
841 
842 	/*
843 	 * Now we are sure the file is inside our tree.
844 	 * If it is a symbolic link, ignore the real path
845 	 * and use the original name.
846 	 */
847 	do {
848 		if (S_ISLNK(st.st_mode) == 0)
849 			break;
850 
851 		/*
852 		 * Some implementations of realpath(3) may succeed
853 		 * even if the target of the link does not exist,
854 		 * so check again for extra safety.
855 		 */
856 		if (stat(usefile, &st) == -1) {
857 			exitcode = (int)MANDOCLEVEL_BADARG;
858 			say(infile, "&stat");
859 			free(usefile);
860 			return;
861 		}
862 		linkfile = mandoc_strdup(infile);
863 		if (op == OP_TEST) {
864 			free(usefile);
865 			start = usefile = linkfile;
866 			break;
867 		}
868 		if (strncmp(infile, basedir, basedir_len) == 0) {
869 			free(usefile);
870 			usefile = linkfile;
871 			start = usefile + basedir_len;
872 			break;
873 		}
874 
875 		/*
876 		 * This symbolic link points into the basedir
877 		 * from the outside.  Let's see whether any of
878 		 * the parent directories resolve to the basedir.
879 		 */
880 		p = strchr(linkfile, '\0');
881 		do {
882 			while (*--p != '/')
883 				continue;
884 			*p = '\0';
885 			if ((realdir = realpath(linkfile, NULL)) == NULL) {
886 				exitcode = (int)MANDOCLEVEL_BADARG;
887 				say(infile, "&realpath");
888 				free(linkfile);
889 				free(usefile);
890 				return;
891 			}
892 			realdir_len = strlen(realdir) + 1;
893 			free(realdir);
894 			*p = '/';
895 		} while (realdir_len > basedir_len);
896 
897 		/*
898 		 * If one of the directories resolves to the basedir,
899 		 * use the rest of the original name.
900 		 * Otherwise, the best we can do
901 		 * is to use the filename pointed to.
902 		 */
903 		if (realdir_len == basedir_len) {
904 			free(usefile);
905 			usefile = linkfile;
906 			start = p + 1;
907 		} else {
908 			free(linkfile);
909 			start = usefile + basedir_len;
910 		}
911 	} while (/* CONSTCOND */ 0);
912 
913 	mlink = mandoc_calloc(1, sizeof(struct mlink));
914 	mlink->dform = FORM_NONE;
915 	if (strlcpy(mlink->file, start, sizeof(mlink->file)) >=
916 	    sizeof(mlink->file)) {
917 		say(start, "Filename too long");
918 		free(mlink);
919 		free(usefile);
920 		return;
921 	}
922 
923 	/*
924 	 * In test mode or when the original name is absolute
925 	 * but outside our tree, guess the base directory.
926 	 */
927 
928 	if (op == OP_TEST || (start == usefile && *start == '/')) {
929 		if (strncmp(usefile, "man/", 4) == 0)
930 			start = usefile + 4;
931 		else if ((start = strstr(usefile, "/man/")) != NULL)
932 			start += 5;
933 		else
934 			start = usefile;
935 	}
936 
937 	/*
938 	 * First try to guess our directory structure.
939 	 * If we find a separator, try to look for man* or cat*.
940 	 * If we find one of these and what's underneath is a directory,
941 	 * assume it's an architecture.
942 	 */
943 	if ((p = strchr(start, '/')) != NULL) {
944 		*p++ = '\0';
945 		if (strncmp(start, "man", 3) == 0) {
946 			mlink->dform = FORM_SRC;
947 			mlink->dsec = start + 3;
948 		} else if (strncmp(start, "cat", 3) == 0) {
949 			mlink->dform = FORM_CAT;
950 			mlink->dsec = start + 3;
951 		}
952 
953 		start = p;
954 		if (mlink->dsec != NULL && (p = strchr(start, '/')) != NULL) {
955 			*p++ = '\0';
956 			mlink->arch = start;
957 			start = p;
958 		}
959 	}
960 
961 	/*
962 	 * Now check the file suffix.
963 	 * Suffix of `.0' indicates a catpage, `.1-9' is a manpage.
964 	 */
965 	p = strrchr(start, '\0');
966 	while (p-- > start && *p != '/' && *p != '.')
967 		continue;
968 
969 	if (*p == '.') {
970 		*p++ = '\0';
971 		mlink->fsec = p;
972 	}
973 
974 	/*
975 	 * Now try to parse the name.
976 	 * Use the filename portion of the path.
977 	 */
978 	mlink->name = start;
979 	if ((p = strrchr(start, '/')) != NULL) {
980 		mlink->name = p + 1;
981 		*p = '\0';
982 	}
983 	mlink_add(mlink, &st);
984 	free(usefile);
985 }
986 
987 static void
988 mlink_add(struct mlink *mlink, const struct stat *st)
989 {
990 	struct inodev	 inodev;
991 	struct mpage	*mpage;
992 	unsigned int	 slot;
993 
994 	assert(NULL != mlink->file);
995 
996 	mlink->dsec = mandoc_strdup(mlink->dsec ? mlink->dsec : "");
997 	mlink->arch = mandoc_strdup(mlink->arch ? mlink->arch : "");
998 	mlink->name = mandoc_strdup(mlink->name ? mlink->name : "");
999 	mlink->fsec = mandoc_strdup(mlink->fsec ? mlink->fsec : "");
1000 
1001 	if ('0' == *mlink->fsec) {
1002 		free(mlink->fsec);
1003 		mlink->fsec = mandoc_strdup(mlink->dsec);
1004 		mlink->fform = FORM_CAT;
1005 	} else if ('1' <= *mlink->fsec && '9' >= *mlink->fsec)
1006 		mlink->fform = FORM_SRC;
1007 	else
1008 		mlink->fform = FORM_NONE;
1009 
1010 	slot = ohash_qlookup(&mlinks, mlink->file);
1011 	assert(NULL == ohash_find(&mlinks, slot));
1012 	ohash_insert(&mlinks, slot, mlink);
1013 
1014 	memset(&inodev, 0, sizeof(inodev));  /* Clear padding. */
1015 	inodev.st_ino = st->st_ino;
1016 	inodev.st_dev = st->st_dev;
1017 	slot = ohash_lookup_memory(&mpages, (char *)&inodev,
1018 	    sizeof(struct inodev), inodev.st_ino);
1019 	mpage = ohash_find(&mpages, slot);
1020 	if (NULL == mpage) {
1021 		mpage = mandoc_calloc(1, sizeof(struct mpage));
1022 		mpage->inodev.st_ino = inodev.st_ino;
1023 		mpage->inodev.st_dev = inodev.st_dev;
1024 		mpage->form = FORM_NONE;
1025 		mpage->next = mpage_head;
1026 		mpage_head = mpage;
1027 		ohash_insert(&mpages, slot, mpage);
1028 	} else
1029 		mlink->next = mpage->mlinks;
1030 	mpage->mlinks = mlink;
1031 	mlink->mpage = mpage;
1032 }
1033 
1034 static void
1035 mlink_free(struct mlink *mlink)
1036 {
1037 
1038 	free(mlink->dsec);
1039 	free(mlink->arch);
1040 	free(mlink->name);
1041 	free(mlink->fsec);
1042 	free(mlink);
1043 }
1044 
1045 static void
1046 mpages_free(void)
1047 {
1048 	struct mpage	*mpage;
1049 	struct mlink	*mlink;
1050 
1051 	while ((mpage = mpage_head) != NULL) {
1052 		while ((mlink = mpage->mlinks) != NULL) {
1053 			mpage->mlinks = mlink->next;
1054 			mlink_free(mlink);
1055 		}
1056 		mpage_head = mpage->next;
1057 		free(mpage->sec);
1058 		free(mpage->arch);
1059 		free(mpage->title);
1060 		free(mpage->desc);
1061 		free(mpage);
1062 	}
1063 }
1064 
1065 /*
1066  * For each mlink to the mpage, check whether the path looks like
1067  * it is formatted, and if it does, check whether a source manual
1068  * exists by the same name, ignoring the suffix.
1069  * If both conditions hold, drop the mlink.
1070  */
1071 static void
1072 mlinks_undupe(struct mpage *mpage)
1073 {
1074 	char		  buf[PATH_MAX];
1075 	struct mlink	**prev;
1076 	struct mlink	 *mlink;
1077 	char		 *bufp;
1078 
1079 	mpage->form = FORM_CAT;
1080 	prev = &mpage->mlinks;
1081 	while (NULL != (mlink = *prev)) {
1082 		if (FORM_CAT != mlink->dform) {
1083 			mpage->form = FORM_NONE;
1084 			goto nextlink;
1085 		}
1086 		(void)strlcpy(buf, mlink->file, sizeof(buf));
1087 		bufp = strstr(buf, "cat");
1088 		assert(NULL != bufp);
1089 		memcpy(bufp, "man", 3);
1090 		if (NULL != (bufp = strrchr(buf, '.')))
1091 			*++bufp = '\0';
1092 		(void)strlcat(buf, mlink->dsec, sizeof(buf));
1093 		if (NULL == ohash_find(&mlinks,
1094 		    ohash_qlookup(&mlinks, buf)))
1095 			goto nextlink;
1096 		if (warnings)
1097 			say(mlink->file, "Man source exists: %s", buf);
1098 		if (use_all)
1099 			goto nextlink;
1100 		*prev = mlink->next;
1101 		mlink_free(mlink);
1102 		continue;
1103 nextlink:
1104 		prev = &(*prev)->next;
1105 	}
1106 }
1107 
1108 static void
1109 mlink_check(struct mpage *mpage, struct mlink *mlink)
1110 {
1111 	struct str	*str;
1112 	unsigned int	 slot;
1113 
1114 	/*
1115 	 * Check whether the manual section given in a file
1116 	 * agrees with the directory where the file is located.
1117 	 * Some manuals have suffixes like (3p) on their
1118 	 * section number either inside the file or in the
1119 	 * directory name, some are linked into more than one
1120 	 * section, like encrypt(1) = makekey(8).
1121 	 */
1122 
1123 	if (FORM_SRC == mpage->form &&
1124 	    strcasecmp(mpage->sec, mlink->dsec))
1125 		say(mlink->file, "Section \"%s\" manual in %s directory",
1126 		    mpage->sec, mlink->dsec);
1127 
1128 	/*
1129 	 * Manual page directories exist for each kernel
1130 	 * architecture as returned by machine(1).
1131 	 * However, many manuals only depend on the
1132 	 * application architecture as returned by arch(1).
1133 	 * For example, some (2/ARM) manuals are shared
1134 	 * across the "armish" and "zaurus" kernel
1135 	 * architectures.
1136 	 * A few manuals are even shared across completely
1137 	 * different architectures, for example fdformat(1)
1138 	 * on amd64, i386, and sparc64.
1139 	 */
1140 
1141 	if (strcasecmp(mpage->arch, mlink->arch))
1142 		say(mlink->file, "Architecture \"%s\" manual in "
1143 		    "\"%s\" directory", mpage->arch, mlink->arch);
1144 
1145 	/*
1146 	 * XXX
1147 	 * parse_cat() doesn't set NAME_TITLE yet.
1148 	 */
1149 
1150 	if (FORM_CAT == mpage->form)
1151 		return;
1152 
1153 	/*
1154 	 * Check whether this mlink
1155 	 * appears as a name in the NAME section.
1156 	 */
1157 
1158 	slot = ohash_qlookup(&names, mlink->name);
1159 	str = ohash_find(&names, slot);
1160 	assert(NULL != str);
1161 	if ( ! (NAME_TITLE & str->mask))
1162 		say(mlink->file, "Name missing in NAME section");
1163 }
1164 
1165 /*
1166  * Run through the files in the global vector "mpages"
1167  * and add them to the database specified in "basedir".
1168  *
1169  * This handles the parsing scheme itself, using the cues of directory
1170  * and filename to determine whether the file is parsable or not.
1171  */
1172 static void
1173 mpages_merge(struct dba *dba, struct mparse *mp)
1174 {
1175 	struct mpage		*mpage, *mpage_dest;
1176 	struct mlink		*mlink, *mlink_dest;
1177 	struct roff_meta	*meta;
1178 	char			*cp;
1179 	int			 fd;
1180 
1181 	for (mpage = mpage_head; mpage != NULL; mpage = mpage->next) {
1182 		mlinks_undupe(mpage);
1183 		if ((mlink = mpage->mlinks) == NULL)
1184 			continue;
1185 
1186 		name_mask = NAME_MASK;
1187 		mandoc_ohash_init(&names, 4, offsetof(struct str, key));
1188 		mandoc_ohash_init(&strings, 6, offsetof(struct str, key));
1189 		mparse_reset(mp);
1190 		meta = NULL;
1191 
1192 		if ((fd = mparse_open(mp, mlink->file)) == -1) {
1193 			say(mlink->file, "&open");
1194 			goto nextpage;
1195 		}
1196 
1197 		/*
1198 		 * Interpret the file as mdoc(7) or man(7) source
1199 		 * code, unless it is known to be formatted.
1200 		 */
1201 		if (mlink->dform != FORM_CAT || mlink->fform != FORM_CAT) {
1202 			mparse_readfd(mp, fd, mlink->file);
1203 			close(fd);
1204 			fd = -1;
1205 			meta = mparse_result(mp);
1206 		}
1207 
1208 		if (meta != NULL && meta->sodest != NULL) {
1209 			mlink_dest = ohash_find(&mlinks,
1210 			    ohash_qlookup(&mlinks, meta->sodest));
1211 			if (mlink_dest == NULL) {
1212 				mandoc_asprintf(&cp, "%s.gz", meta->sodest);
1213 				mlink_dest = ohash_find(&mlinks,
1214 				    ohash_qlookup(&mlinks, cp));
1215 				free(cp);
1216 			}
1217 			if (mlink_dest != NULL) {
1218 
1219 				/* The .so target exists. */
1220 
1221 				mpage_dest = mlink_dest->mpage;
1222 				while (1) {
1223 					mlink->mpage = mpage_dest;
1224 
1225 					/*
1226 					 * If the target was already
1227 					 * processed, add the links
1228 					 * to the database now.
1229 					 * Otherwise, this will
1230 					 * happen when we come
1231 					 * to the target.
1232 					 */
1233 
1234 					if (mpage_dest->dba != NULL)
1235 						dbadd_mlink(mlink);
1236 
1237 					if (mlink->next == NULL)
1238 						break;
1239 					mlink = mlink->next;
1240 				}
1241 
1242 				/* Move all links to the target. */
1243 
1244 				mlink->next = mlink_dest->next;
1245 				mlink_dest->next = mpage->mlinks;
1246 				mpage->mlinks = NULL;
1247 				goto nextpage;
1248 			}
1249 			meta->macroset = MACROSET_NONE;
1250 		}
1251 		if (meta != NULL && meta->macroset == MACROSET_MDOC) {
1252 			mpage->form = FORM_SRC;
1253 			mpage->sec = meta->msec;
1254 			mpage->sec = mandoc_strdup(
1255 			    mpage->sec == NULL ? "" : mpage->sec);
1256 			mpage->arch = meta->arch;
1257 			mpage->arch = mandoc_strdup(
1258 			    mpage->arch == NULL ? "" : mpage->arch);
1259 			mpage->title = mandoc_strdup(meta->title);
1260 		} else if (meta != NULL && meta->macroset == MACROSET_MAN) {
1261 			if (*meta->msec != '\0' || *meta->title != '\0') {
1262 				mpage->form = FORM_SRC;
1263 				mpage->sec = mandoc_strdup(meta->msec);
1264 				mpage->arch = mandoc_strdup(mlink->arch);
1265 				mpage->title = mandoc_strdup(meta->title);
1266 			} else
1267 				meta = NULL;
1268 		}
1269 
1270 		assert(mpage->desc == NULL);
1271 		if (meta == NULL || meta->sodest != NULL) {
1272 			mpage->sec = mandoc_strdup(mlink->dsec);
1273 			mpage->arch = mandoc_strdup(mlink->arch);
1274 			mpage->title = mandoc_strdup(mlink->name);
1275 			if (meta == NULL) {
1276 				mpage->form = FORM_CAT;
1277 				parse_cat(mpage, fd);
1278 			} else
1279 				mpage->form = FORM_SRC;
1280 		} else if (meta->macroset == MACROSET_MDOC)
1281 			parse_mdoc(mpage, meta, meta->first);
1282 		else
1283 			parse_man(mpage, meta, meta->first);
1284 		if (mpage->desc == NULL) {
1285 			mpage->desc = mandoc_strdup(mlink->name);
1286 			if (warnings)
1287 				say(mlink->file, "No one-line description, "
1288 				    "using filename \"%s\"", mlink->name);
1289 		}
1290 
1291 		for (mlink = mpage->mlinks;
1292 		     mlink != NULL;
1293 		     mlink = mlink->next) {
1294 			putkey(mpage, mlink->name, NAME_FILE);
1295 			if (warnings && !use_all)
1296 				mlink_check(mpage, mlink);
1297 		}
1298 
1299 		dbadd(dba, mpage);
1300 
1301 nextpage:
1302 		ohash_delete(&strings);
1303 		ohash_delete(&names);
1304 	}
1305 }
1306 
1307 static void
1308 parse_cat(struct mpage *mpage, int fd)
1309 {
1310 	FILE		*stream;
1311 	struct mlink	*mlink;
1312 	char		*line, *p, *title, *sec;
1313 	size_t		 linesz, plen, titlesz;
1314 	ssize_t		 len;
1315 	int		 offs;
1316 
1317 	mlink = mpage->mlinks;
1318 	stream = fd == -1 ? fopen(mlink->file, "r") : fdopen(fd, "r");
1319 	if (stream == NULL) {
1320 		if (fd != -1)
1321 			close(fd);
1322 		if (warnings)
1323 			say(mlink->file, "&fopen");
1324 		return;
1325 	}
1326 
1327 	line = NULL;
1328 	linesz = 0;
1329 
1330 	/* Parse the section number from the header line. */
1331 
1332 	while (getline(&line, &linesz, stream) != -1) {
1333 		if (*line == '\n')
1334 			continue;
1335 		if ((sec = strchr(line, '(')) == NULL)
1336 			break;
1337 		if ((p = strchr(++sec, ')')) == NULL)
1338 			break;
1339 		free(mpage->sec);
1340 		mpage->sec = mandoc_strndup(sec, p - sec);
1341 		if (warnings && *mlink->dsec != '\0' &&
1342 		    strcasecmp(mpage->sec, mlink->dsec))
1343 			say(mlink->file,
1344 			    "Section \"%s\" manual in %s directory",
1345 			    mpage->sec, mlink->dsec);
1346 		break;
1347 	}
1348 
1349 	/* Skip to first blank line. */
1350 
1351 	while (line == NULL || *line != '\n')
1352 		if (getline(&line, &linesz, stream) == -1)
1353 			break;
1354 
1355 	/*
1356 	 * Assume the first line that is not indented
1357 	 * is the first section header.  Skip to it.
1358 	 */
1359 
1360 	while (getline(&line, &linesz, stream) != -1)
1361 		if (*line != '\n' && *line != ' ')
1362 			break;
1363 
1364 	/*
1365 	 * Read up until the next section into a buffer.
1366 	 * Strip the leading and trailing newline from each read line,
1367 	 * appending a trailing space.
1368 	 * Ignore empty (whitespace-only) lines.
1369 	 */
1370 
1371 	titlesz = 0;
1372 	title = NULL;
1373 
1374 	while ((len = getline(&line, &linesz, stream)) != -1) {
1375 		if (*line != ' ')
1376 			break;
1377 		offs = 0;
1378 		while (isspace((unsigned char)line[offs]))
1379 			offs++;
1380 		if (line[offs] == '\0')
1381 			continue;
1382 		title = mandoc_realloc(title, titlesz + len - offs);
1383 		memcpy(title + titlesz, line + offs, len - offs);
1384 		titlesz += len - offs;
1385 		title[titlesz - 1] = ' ';
1386 	}
1387 	free(line);
1388 
1389 	/*
1390 	 * If no page content can be found, or the input line
1391 	 * is already the next section header, or there is no
1392 	 * trailing newline, reuse the page title as the page
1393 	 * description.
1394 	 */
1395 
1396 	if (NULL == title || '\0' == *title) {
1397 		if (warnings)
1398 			say(mlink->file, "Cannot find NAME section");
1399 		fclose(stream);
1400 		free(title);
1401 		return;
1402 	}
1403 
1404 	title[titlesz - 1] = '\0';
1405 
1406 	/*
1407 	 * Skip to the first dash.
1408 	 * Use the remaining line as the description (no more than 70
1409 	 * bytes).
1410 	 */
1411 
1412 	if (NULL != (p = strstr(title, "- "))) {
1413 		for (p += 2; ' ' == *p || '\b' == *p; p++)
1414 			/* Skip to next word. */ ;
1415 	} else {
1416 		if (warnings)
1417 			say(mlink->file, "No dash in title line, "
1418 			    "reusing \"%s\" as one-line description", title);
1419 		p = title;
1420 	}
1421 
1422 	plen = strlen(p);
1423 
1424 	/* Strip backspace-encoding from line. */
1425 
1426 	while (NULL != (line = memchr(p, '\b', plen))) {
1427 		len = line - p;
1428 		if (0 == len) {
1429 			memmove(line, line + 1, plen--);
1430 			continue;
1431 		}
1432 		memmove(line - 1, line + 1, plen - len);
1433 		plen -= 2;
1434 	}
1435 
1436 	/*
1437 	 * Cut off excessive one-line descriptions.
1438 	 * Bad pages are not worth better heuristics.
1439 	 */
1440 
1441 	mpage->desc = mandoc_strndup(p, 150);
1442 	fclose(stream);
1443 	free(title);
1444 }
1445 
1446 /*
1447  * Put a type/word pair into the word database for this particular file.
1448  */
1449 static void
1450 putkey(const struct mpage *mpage, char *value, uint64_t type)
1451 {
1452 	putkeys(mpage, value, strlen(value), type);
1453 }
1454 
1455 /*
1456  * Grok all nodes at or below a certain mdoc node into putkey().
1457  */
1458 static void
1459 putmdockey(const struct mpage *mpage,
1460 	const struct roff_node *n, uint64_t m, int taboo)
1461 {
1462 
1463 	for ( ; NULL != n; n = n->next) {
1464 		if (n->flags & taboo)
1465 			continue;
1466 		if (NULL != n->child)
1467 			putmdockey(mpage, n->child, m, taboo);
1468 		if (n->type == ROFFT_TEXT)
1469 			putkey(mpage, n->string, m);
1470 	}
1471 }
1472 
1473 static void
1474 parse_man(struct mpage *mpage, const struct roff_meta *meta,
1475 	const struct roff_node *n)
1476 {
1477 	const struct roff_node *head, *body;
1478 	char		*start, *title;
1479 	char		 byte;
1480 	size_t		 sz;
1481 
1482 	if (n == NULL)
1483 		return;
1484 
1485 	/*
1486 	 * We're only searching for one thing: the first text child in
1487 	 * the BODY of a NAME section.  Since we don't keep track of
1488 	 * sections in -man, run some hoops to find out whether we're in
1489 	 * the correct section or not.
1490 	 */
1491 
1492 	if (n->type == ROFFT_BODY && n->tok == MAN_SH) {
1493 		body = n;
1494 		if ((head = body->parent->head) != NULL &&
1495 		    (head = head->child) != NULL &&
1496 		    head->next == NULL &&
1497 		    head->type == ROFFT_TEXT &&
1498 		    strcmp(head->string, "NAME") == 0 &&
1499 		    body->child != NULL) {
1500 
1501 			/*
1502 			 * Suck the entire NAME section into memory.
1503 			 * Yes, we might run away.
1504 			 * But too many manuals have big, spread-out
1505 			 * NAME sections over many lines.
1506 			 */
1507 
1508 			title = NULL;
1509 			deroff(&title, body);
1510 			if (NULL == title)
1511 				return;
1512 
1513 			/*
1514 			 * Go through a special heuristic dance here.
1515 			 * Conventionally, one or more manual names are
1516 			 * comma-specified prior to a whitespace, then a
1517 			 * dash, then a description.  Try to puzzle out
1518 			 * the name parts here.
1519 			 */
1520 
1521 			start = title;
1522 			for ( ;; ) {
1523 				sz = strcspn(start, " ,");
1524 				if ('\0' == start[sz])
1525 					break;
1526 
1527 				byte = start[sz];
1528 				start[sz] = '\0';
1529 
1530 				/*
1531 				 * Assume a stray trailing comma in the
1532 				 * name list if a name begins with a dash.
1533 				 */
1534 
1535 				if ('-' == start[0] ||
1536 				    ('\\' == start[0] && '-' == start[1]))
1537 					break;
1538 
1539 				putkey(mpage, start, NAME_TITLE);
1540 				if ( ! (mpage->name_head_done ||
1541 				    strcasecmp(start, meta->title))) {
1542 					putkey(mpage, start, NAME_HEAD);
1543 					mpage->name_head_done = 1;
1544 				}
1545 
1546 				if (' ' == byte) {
1547 					start += sz + 1;
1548 					break;
1549 				}
1550 
1551 				assert(',' == byte);
1552 				start += sz + 1;
1553 				while (' ' == *start)
1554 					start++;
1555 			}
1556 
1557 			if (start == title) {
1558 				putkey(mpage, start, NAME_TITLE);
1559 				if ( ! (mpage->name_head_done ||
1560 				    strcasecmp(start, meta->title))) {
1561 					putkey(mpage, start, NAME_HEAD);
1562 					mpage->name_head_done = 1;
1563 				}
1564 				free(title);
1565 				return;
1566 			}
1567 
1568 			while (isspace((unsigned char)*start))
1569 				start++;
1570 
1571 			if (0 == strncmp(start, "-", 1))
1572 				start += 1;
1573 			else if (0 == strncmp(start, "\\-\\-", 4))
1574 				start += 4;
1575 			else if (0 == strncmp(start, "\\-", 2))
1576 				start += 2;
1577 			else if (0 == strncmp(start, "\\(en", 4))
1578 				start += 4;
1579 			else if (0 == strncmp(start, "\\(em", 4))
1580 				start += 4;
1581 
1582 			while (' ' == *start)
1583 				start++;
1584 
1585 			/*
1586 			 * Cut off excessive one-line descriptions.
1587 			 * Bad pages are not worth better heuristics.
1588 			 */
1589 
1590 			mpage->desc = mandoc_strndup(start, 150);
1591 			free(title);
1592 			return;
1593 		}
1594 	}
1595 
1596 	for (n = n->child; n; n = n->next) {
1597 		if (NULL != mpage->desc)
1598 			break;
1599 		parse_man(mpage, meta, n);
1600 	}
1601 }
1602 
1603 static void
1604 parse_mdoc(struct mpage *mpage, const struct roff_meta *meta,
1605 	const struct roff_node *n)
1606 {
1607 	const struct mdoc_handler *handler;
1608 
1609 	for (n = n->child; n != NULL; n = n->next) {
1610 		if (n->tok == TOKEN_NONE || n->tok < ROFF_MAX)
1611 			continue;
1612 		assert(n->tok >= MDOC_Dd && n->tok < MDOC_MAX);
1613 		handler = mdoc_handlers + (n->tok - MDOC_Dd);
1614 		if (n->flags & handler->taboo)
1615 			continue;
1616 
1617 		switch (n->type) {
1618 		case ROFFT_ELEM:
1619 		case ROFFT_BLOCK:
1620 		case ROFFT_HEAD:
1621 		case ROFFT_BODY:
1622 		case ROFFT_TAIL:
1623 			if (handler->fp != NULL &&
1624 			    (*handler->fp)(mpage, meta, n) == 0)
1625 				break;
1626 			if (handler->mask)
1627 				putmdockey(mpage, n->child,
1628 				    handler->mask, handler->taboo);
1629 			break;
1630 		default:
1631 			continue;
1632 		}
1633 		if (NULL != n->child)
1634 			parse_mdoc(mpage, meta, n);
1635 	}
1636 }
1637 
1638 static int
1639 parse_mdoc_Fa(struct mpage *mpage, const struct roff_meta *meta,
1640 	const struct roff_node *n)
1641 {
1642 	uint64_t mask;
1643 
1644 	mask = TYPE_Fa;
1645 	if (n->sec == SEC_SYNOPSIS)
1646 		mask |= TYPE_Vt;
1647 
1648 	putmdockey(mpage, n->child, mask, 0);
1649 	return 0;
1650 }
1651 
1652 static int
1653 parse_mdoc_Fd(struct mpage *mpage, const struct roff_meta *meta,
1654 	const struct roff_node *n)
1655 {
1656 	char		*start, *end;
1657 	size_t		 sz;
1658 
1659 	if (SEC_SYNOPSIS != n->sec ||
1660 	    NULL == (n = n->child) ||
1661 	    n->type != ROFFT_TEXT)
1662 		return 0;
1663 
1664 	/*
1665 	 * Only consider those `Fd' macro fields that begin with an
1666 	 * "inclusion" token (versus, e.g., #define).
1667 	 */
1668 
1669 	if (strcmp("#include", n->string))
1670 		return 0;
1671 
1672 	if ((n = n->next) == NULL || n->type != ROFFT_TEXT)
1673 		return 0;
1674 
1675 	/*
1676 	 * Strip away the enclosing angle brackets and make sure we're
1677 	 * not zero-length.
1678 	 */
1679 
1680 	start = n->string;
1681 	if ('<' == *start || '"' == *start)
1682 		start++;
1683 
1684 	if (0 == (sz = strlen(start)))
1685 		return 0;
1686 
1687 	end = &start[(int)sz - 1];
1688 	if ('>' == *end || '"' == *end)
1689 		end--;
1690 
1691 	if (end > start)
1692 		putkeys(mpage, start, end - start + 1, TYPE_In);
1693 	return 0;
1694 }
1695 
1696 static void
1697 parse_mdoc_fname(struct mpage *mpage, const struct roff_node *n)
1698 {
1699 	char	*cp;
1700 	size_t	 sz;
1701 
1702 	if (n->type != ROFFT_TEXT)
1703 		return;
1704 
1705 	/* Skip function pointer punctuation. */
1706 
1707 	cp = n->string;
1708 	while (*cp == '(' || *cp == '*')
1709 		cp++;
1710 	sz = strcspn(cp, "()");
1711 
1712 	putkeys(mpage, cp, sz, TYPE_Fn);
1713 	if (n->sec == SEC_SYNOPSIS)
1714 		putkeys(mpage, cp, sz, NAME_SYN);
1715 }
1716 
1717 static int
1718 parse_mdoc_Fn(struct mpage *mpage, const struct roff_meta *meta,
1719 	const struct roff_node *n)
1720 {
1721 	uint64_t mask;
1722 
1723 	if (n->child == NULL)
1724 		return 0;
1725 
1726 	parse_mdoc_fname(mpage, n->child);
1727 
1728 	n = n->child->next;
1729 	if (n != NULL && n->type == ROFFT_TEXT) {
1730 		mask = TYPE_Fa;
1731 		if (n->sec == SEC_SYNOPSIS)
1732 			mask |= TYPE_Vt;
1733 		putmdockey(mpage, n, mask, 0);
1734 	}
1735 
1736 	return 0;
1737 }
1738 
1739 static int
1740 parse_mdoc_Fo(struct mpage *mpage, const struct roff_meta *meta,
1741 	const struct roff_node *n)
1742 {
1743 
1744 	if (n->type != ROFFT_HEAD)
1745 		return 1;
1746 
1747 	if (n->child != NULL)
1748 		parse_mdoc_fname(mpage, n->child);
1749 
1750 	return 0;
1751 }
1752 
1753 static int
1754 parse_mdoc_Va(struct mpage *mpage, const struct roff_meta *meta,
1755 	const struct roff_node *n)
1756 {
1757 	char *cp;
1758 
1759 	if (n->type != ROFFT_ELEM && n->type != ROFFT_BODY)
1760 		return 0;
1761 
1762 	if (n->child != NULL &&
1763 	    n->child->next == NULL &&
1764 	    n->child->type == ROFFT_TEXT)
1765 		return 1;
1766 
1767 	cp = NULL;
1768 	deroff(&cp, n);
1769 	if (cp != NULL) {
1770 		putkey(mpage, cp, TYPE_Vt | (n->tok == MDOC_Va ||
1771 		    n->type == ROFFT_BODY ? TYPE_Va : 0));
1772 		free(cp);
1773 	}
1774 
1775 	return 0;
1776 }
1777 
1778 static int
1779 parse_mdoc_Xr(struct mpage *mpage, const struct roff_meta *meta,
1780 	const struct roff_node *n)
1781 {
1782 	char	*cp;
1783 
1784 	if (NULL == (n = n->child))
1785 		return 0;
1786 
1787 	if (NULL == n->next) {
1788 		putkey(mpage, n->string, TYPE_Xr);
1789 		return 0;
1790 	}
1791 
1792 	mandoc_asprintf(&cp, "%s(%s)", n->string, n->next->string);
1793 	putkey(mpage, cp, TYPE_Xr);
1794 	free(cp);
1795 	return 0;
1796 }
1797 
1798 static int
1799 parse_mdoc_Nd(struct mpage *mpage, const struct roff_meta *meta,
1800 	const struct roff_node *n)
1801 {
1802 
1803 	if (n->type == ROFFT_BODY)
1804 		deroff(&mpage->desc, n);
1805 	return 0;
1806 }
1807 
1808 static int
1809 parse_mdoc_Nm(struct mpage *mpage, const struct roff_meta *meta,
1810 	const struct roff_node *n)
1811 {
1812 
1813 	if (SEC_NAME == n->sec)
1814 		putmdockey(mpage, n->child, NAME_TITLE, 0);
1815 	else if (n->sec == SEC_SYNOPSIS && n->type == ROFFT_HEAD) {
1816 		if (n->child == NULL)
1817 			putkey(mpage, meta->name, NAME_SYN);
1818 		else
1819 			putmdockey(mpage, n->child, NAME_SYN, 0);
1820 	}
1821 	if ( ! (mpage->name_head_done ||
1822 	    n->child == NULL || n->child->string == NULL ||
1823 	    strcasecmp(n->child->string, meta->title))) {
1824 		putkey(mpage, n->child->string, NAME_HEAD);
1825 		mpage->name_head_done = 1;
1826 	}
1827 	return 0;
1828 }
1829 
1830 static int
1831 parse_mdoc_Sh(struct mpage *mpage, const struct roff_meta *meta,
1832 	const struct roff_node *n)
1833 {
1834 
1835 	return n->sec == SEC_CUSTOM && n->type == ROFFT_HEAD;
1836 }
1837 
1838 static int
1839 parse_mdoc_head(struct mpage *mpage, const struct roff_meta *meta,
1840 	const struct roff_node *n)
1841 {
1842 
1843 	return n->type == ROFFT_HEAD;
1844 }
1845 
1846 /*
1847  * Add a string to the hash table for the current manual.
1848  * Each string has a bitmask telling which macros it belongs to.
1849  * When we finish the manual, we'll dump the table.
1850  */
1851 static void
1852 putkeys(const struct mpage *mpage, char *cp, size_t sz, uint64_t v)
1853 {
1854 	struct ohash	*htab;
1855 	struct str	*s;
1856 	const char	*end;
1857 	unsigned int	 slot;
1858 	int		 i, mustfree;
1859 
1860 	if (0 == sz)
1861 		return;
1862 
1863 	mustfree = render_string(&cp, &sz);
1864 
1865 	if (TYPE_Nm & v) {
1866 		htab = &names;
1867 		v &= name_mask;
1868 		if (v & NAME_FIRST)
1869 			name_mask &= ~NAME_FIRST;
1870 		if (debug > 1)
1871 			say(mpage->mlinks->file,
1872 			    "Adding name %*s, bits=0x%llx", (int)sz, cp,
1873 			    (unsigned long long)v);
1874 	} else {
1875 		htab = &strings;
1876 		if (debug > 1)
1877 		    for (i = 0; i < KEY_MAX; i++)
1878 			if ((uint64_t)1 << i & v)
1879 			    say(mpage->mlinks->file,
1880 				"Adding key %s=%*s",
1881 				mansearch_keynames[i], (int)sz, cp);
1882 	}
1883 
1884 	end = cp + sz;
1885 	slot = ohash_qlookupi(htab, cp, &end);
1886 	s = ohash_find(htab, slot);
1887 
1888 	if (NULL != s && mpage == s->mpage) {
1889 		s->mask |= v;
1890 		return;
1891 	} else if (NULL == s) {
1892 		s = mandoc_calloc(1, sizeof(struct str) + sz + 1);
1893 		memcpy(s->key, cp, sz);
1894 		ohash_insert(htab, slot, s);
1895 	}
1896 	s->mpage = mpage;
1897 	s->mask = v;
1898 
1899 	if (mustfree)
1900 		free(cp);
1901 }
1902 
1903 /*
1904  * Take a Unicode codepoint and produce its UTF-8 encoding.
1905  * This isn't the best way to do this, but it works.
1906  * The magic numbers are from the UTF-8 packaging.
1907  * They're not as scary as they seem: read the UTF-8 spec for details.
1908  */
1909 static size_t
1910 utf8(unsigned int cp, char out[7])
1911 {
1912 	size_t		 rc;
1913 
1914 	rc = 0;
1915 	if (cp <= 0x0000007F) {
1916 		rc = 1;
1917 		out[0] = (char)cp;
1918 	} else if (cp <= 0x000007FF) {
1919 		rc = 2;
1920 		out[0] = (cp >> 6  & 31) | 192;
1921 		out[1] = (cp       & 63) | 128;
1922 	} else if (cp <= 0x0000FFFF) {
1923 		rc = 3;
1924 		out[0] = (cp >> 12 & 15) | 224;
1925 		out[1] = (cp >> 6  & 63) | 128;
1926 		out[2] = (cp       & 63) | 128;
1927 	} else if (cp <= 0x001FFFFF) {
1928 		rc = 4;
1929 		out[0] = (cp >> 18 &  7) | 240;
1930 		out[1] = (cp >> 12 & 63) | 128;
1931 		out[2] = (cp >> 6  & 63) | 128;
1932 		out[3] = (cp       & 63) | 128;
1933 	} else if (cp <= 0x03FFFFFF) {
1934 		rc = 5;
1935 		out[0] = (cp >> 24 &  3) | 248;
1936 		out[1] = (cp >> 18 & 63) | 128;
1937 		out[2] = (cp >> 12 & 63) | 128;
1938 		out[3] = (cp >> 6  & 63) | 128;
1939 		out[4] = (cp       & 63) | 128;
1940 	} else if (cp <= 0x7FFFFFFF) {
1941 		rc = 6;
1942 		out[0] = (cp >> 30 &  1) | 252;
1943 		out[1] = (cp >> 24 & 63) | 128;
1944 		out[2] = (cp >> 18 & 63) | 128;
1945 		out[3] = (cp >> 12 & 63) | 128;
1946 		out[4] = (cp >> 6  & 63) | 128;
1947 		out[5] = (cp       & 63) | 128;
1948 	} else
1949 		return 0;
1950 
1951 	out[rc] = '\0';
1952 	return rc;
1953 }
1954 
1955 /*
1956  * If the string contains escape sequences,
1957  * replace it with an allocated rendering and return 1,
1958  * such that the caller can free it after use.
1959  * Otherwise, do nothing and return 0.
1960  */
1961 static int
1962 render_string(char **public, size_t *psz)
1963 {
1964 	const char	*src, *scp, *addcp, *seq;
1965 	char		*dst;
1966 	size_t		 ssz, dsz, addsz;
1967 	char		 utfbuf[7], res[6];
1968 	int		 seqlen, unicode;
1969 
1970 	res[0] = '\\';
1971 	res[1] = '\t';
1972 	res[2] = ASCII_NBRSP;
1973 	res[3] = ASCII_HYPH;
1974 	res[4] = ASCII_BREAK;
1975 	res[5] = '\0';
1976 
1977 	src = scp = *public;
1978 	ssz = *psz;
1979 	dst = NULL;
1980 	dsz = 0;
1981 
1982 	while (scp < src + *psz) {
1983 
1984 		/* Leave normal characters unchanged. */
1985 
1986 		if (strchr(res, *scp) == NULL) {
1987 			if (dst != NULL)
1988 				dst[dsz++] = *scp;
1989 			scp++;
1990 			continue;
1991 		}
1992 
1993 		/*
1994 		 * Found something that requires replacing,
1995 		 * make sure we have a destination buffer.
1996 		 */
1997 
1998 		if (dst == NULL) {
1999 			dst = mandoc_malloc(ssz + 1);
2000 			dsz = scp - src;
2001 			memcpy(dst, src, dsz);
2002 		}
2003 
2004 		/* Handle single-char special characters. */
2005 
2006 		switch (*scp) {
2007 		case '\\':
2008 			break;
2009 		case '\t':
2010 		case ASCII_NBRSP:
2011 			dst[dsz++] = ' ';
2012 			scp++;
2013 			continue;
2014 		case ASCII_HYPH:
2015 			dst[dsz++] = '-';
2016 			/* FALLTHROUGH */
2017 		case ASCII_BREAK:
2018 			scp++;
2019 			continue;
2020 		default:
2021 			abort();
2022 		}
2023 
2024 		/*
2025 		 * Found an escape sequence.
2026 		 * Read past the slash, then parse it.
2027 		 * Ignore everything except characters.
2028 		 */
2029 
2030 		scp++;
2031 		if (mandoc_escape(&scp, &seq, &seqlen) != ESCAPE_SPECIAL)
2032 			continue;
2033 
2034 		/*
2035 		 * Render the special character
2036 		 * as either UTF-8 or ASCII.
2037 		 */
2038 
2039 		if (write_utf8) {
2040 			unicode = mchars_spec2cp(seq, seqlen);
2041 			if (unicode <= 0)
2042 				continue;
2043 			addsz = utf8(unicode, utfbuf);
2044 			if (addsz == 0)
2045 				continue;
2046 			addcp = utfbuf;
2047 		} else {
2048 			addcp = mchars_spec2str(seq, seqlen, &addsz);
2049 			if (addcp == NULL)
2050 				continue;
2051 			if (*addcp == ASCII_NBRSP) {
2052 				addcp = " ";
2053 				addsz = 1;
2054 			}
2055 		}
2056 
2057 		/* Copy the rendered glyph into the stream. */
2058 
2059 		ssz += addsz;
2060 		dst = mandoc_realloc(dst, ssz + 1);
2061 		memcpy(dst + dsz, addcp, addsz);
2062 		dsz += addsz;
2063 	}
2064 	if (dst != NULL) {
2065 		*public = dst;
2066 		*psz = dsz;
2067 	}
2068 
2069 	/* Trim trailing whitespace and NUL-terminate. */
2070 
2071 	while (*psz > 0 && (*public)[*psz - 1] == ' ')
2072 		--*psz;
2073 	if (dst != NULL) {
2074 		(*public)[*psz] = '\0';
2075 		return 1;
2076 	} else
2077 		return 0;
2078 }
2079 
2080 static void
2081 dbadd_mlink(const struct mlink *mlink)
2082 {
2083 	dba_page_alias(mlink->mpage->dba, mlink->name, NAME_FILE);
2084 	dba_page_add(mlink->mpage->dba, DBP_SECT, mlink->dsec);
2085 	dba_page_add(mlink->mpage->dba, DBP_SECT, mlink->fsec);
2086 	dba_page_add(mlink->mpage->dba, DBP_ARCH, mlink->arch);
2087 	dba_page_add(mlink->mpage->dba, DBP_FILE, mlink->file);
2088 }
2089 
2090 /*
2091  * Flush the current page's terms (and their bits) into the database.
2092  * Also, handle escape sequences at the last possible moment.
2093  */
2094 static void
2095 dbadd(struct dba *dba, struct mpage *mpage)
2096 {
2097 	struct mlink	*mlink;
2098 	struct str	*key;
2099 	char		*cp;
2100 	uint64_t	 mask;
2101 	size_t		 i;
2102 	unsigned int	 slot;
2103 	int		 mustfree;
2104 
2105 	mlink = mpage->mlinks;
2106 
2107 	if (nodb) {
2108 		for (key = ohash_first(&names, &slot); NULL != key;
2109 		     key = ohash_next(&names, &slot))
2110 			free(key);
2111 		for (key = ohash_first(&strings, &slot); NULL != key;
2112 		     key = ohash_next(&strings, &slot))
2113 			free(key);
2114 		if (0 == debug)
2115 			return;
2116 		while (NULL != mlink) {
2117 			fputs(mlink->name, stdout);
2118 			if (NULL == mlink->next ||
2119 			    strcmp(mlink->dsec, mlink->next->dsec) ||
2120 			    strcmp(mlink->fsec, mlink->next->fsec) ||
2121 			    strcmp(mlink->arch, mlink->next->arch)) {
2122 				putchar('(');
2123 				if ('\0' == *mlink->dsec)
2124 					fputs(mlink->fsec, stdout);
2125 				else
2126 					fputs(mlink->dsec, stdout);
2127 				if ('\0' != *mlink->arch)
2128 					printf("/%s", mlink->arch);
2129 				putchar(')');
2130 			}
2131 			mlink = mlink->next;
2132 			if (NULL != mlink)
2133 				fputs(", ", stdout);
2134 		}
2135 		printf(" - %s\n", mpage->desc);
2136 		return;
2137 	}
2138 
2139 	if (debug)
2140 		say(mlink->file, "Adding to database");
2141 
2142 	cp = mpage->desc;
2143 	i = strlen(cp);
2144 	mustfree = render_string(&cp, &i);
2145 	mpage->dba = dba_page_new(dba->pages,
2146 	    *mpage->arch == '\0' ? mlink->arch : mpage->arch,
2147 	    cp, mlink->file, mpage->form);
2148 	if (mustfree)
2149 		free(cp);
2150 	dba_page_add(mpage->dba, DBP_SECT, mpage->sec);
2151 
2152 	while (mlink != NULL) {
2153 		dbadd_mlink(mlink);
2154 		mlink = mlink->next;
2155 	}
2156 
2157 	for (key = ohash_first(&names, &slot); NULL != key;
2158 	     key = ohash_next(&names, &slot)) {
2159 		assert(key->mpage == mpage);
2160 		dba_page_alias(mpage->dba, key->key, key->mask);
2161 		free(key);
2162 	}
2163 	for (key = ohash_first(&strings, &slot); NULL != key;
2164 	     key = ohash_next(&strings, &slot)) {
2165 		assert(key->mpage == mpage);
2166 		i = 0;
2167 		for (mask = TYPE_Xr; mask <= TYPE_Lb; mask *= 2) {
2168 			if (key->mask & mask)
2169 				dba_macro_add(dba->macros, i,
2170 				    key->key, mpage->dba);
2171 			i++;
2172 		}
2173 		free(key);
2174 	}
2175 }
2176 
2177 static void
2178 dbprune(struct dba *dba)
2179 {
2180 	struct dba_array	*page, *files;
2181 	char			*file;
2182 
2183 	dba_array_FOREACH(dba->pages, page) {
2184 		files = dba_array_get(page, DBP_FILE);
2185 		dba_array_FOREACH(files, file) {
2186 			if (*file < ' ')
2187 				file++;
2188 			if (ohash_find(&mlinks, ohash_qlookup(&mlinks,
2189 			    file)) != NULL) {
2190 				if (debug)
2191 					say(file, "Deleting from database");
2192 				dba_array_del(dba->pages);
2193 				break;
2194 			}
2195 		}
2196 	}
2197 }
2198 
2199 /*
2200  * Write the database from memory to disk.
2201  */
2202 static void
2203 dbwrite(struct dba *dba)
2204 {
2205 	struct stat	 sb1, sb2;
2206 	char		 tfn[33], *cp1, *cp2;
2207 	off_t		 i;
2208 	int		 fd1, fd2;
2209 
2210 	/*
2211 	 * Do not write empty databases, and delete existing ones
2212 	 * when makewhatis -u causes them to become empty.
2213 	 */
2214 
2215 	dba_array_start(dba->pages);
2216 	if (dba_array_next(dba->pages) == NULL) {
2217 		if (unlink(MANDOC_DB) == -1 && errno != ENOENT)
2218 			say(MANDOC_DB, "&unlink");
2219 		return;
2220 	}
2221 
2222 	/*
2223 	 * Build the database in a temporary file,
2224 	 * then atomically move it into place.
2225 	 */
2226 
2227 	if (dba_write(MANDOC_DB "~", dba) != -1) {
2228 		if (rename(MANDOC_DB "~", MANDOC_DB) == -1) {
2229 			exitcode = (int)MANDOCLEVEL_SYSERR;
2230 			say(MANDOC_DB, "&rename");
2231 			unlink(MANDOC_DB "~");
2232 		}
2233 		return;
2234 	}
2235 
2236 	/*
2237 	 * We lack write permission and cannot replace the database
2238 	 * file, but let's at least check whether the data changed.
2239 	 */
2240 
2241 	(void)strlcpy(tfn, "/tmp/mandocdb.XXXXXXXX", sizeof(tfn));
2242 	if (mkdtemp(tfn) == NULL) {
2243 		exitcode = (int)MANDOCLEVEL_SYSERR;
2244 		say("", "&%s", tfn);
2245 		return;
2246 	}
2247 	cp1 = cp2 = MAP_FAILED;
2248 	fd1 = fd2 = -1;
2249 	(void)strlcat(tfn, "/" MANDOC_DB, sizeof(tfn));
2250 	if (dba_write(tfn, dba) == -1) {
2251 		say(tfn, "&dba_write");
2252 		goto err;
2253 	}
2254 	if ((fd1 = open(MANDOC_DB, O_RDONLY, 0)) == -1) {
2255 		say(MANDOC_DB, "&open");
2256 		goto err;
2257 	}
2258 	if ((fd2 = open(tfn, O_RDONLY, 0)) == -1) {
2259 		say(tfn, "&open");
2260 		goto err;
2261 	}
2262 	if (fstat(fd1, &sb1) == -1) {
2263 		say(MANDOC_DB, "&fstat");
2264 		goto err;
2265 	}
2266 	if (fstat(fd2, &sb2) == -1) {
2267 		say(tfn, "&fstat");
2268 		goto err;
2269 	}
2270 	if (sb1.st_size != sb2.st_size)
2271 		goto err;
2272 	if ((cp1 = mmap(NULL, sb1.st_size, PROT_READ, MAP_PRIVATE,
2273 	    fd1, 0)) == MAP_FAILED) {
2274 		say(MANDOC_DB, "&mmap");
2275 		goto err;
2276 	}
2277 	if ((cp2 = mmap(NULL, sb2.st_size, PROT_READ, MAP_PRIVATE,
2278 	    fd2, 0)) == MAP_FAILED) {
2279 		say(tfn, "&mmap");
2280 		goto err;
2281 	}
2282 	for (i = 0; i < sb1.st_size; i++)
2283 		if (cp1[i] != cp2[i])
2284 			goto err;
2285 	goto out;
2286 
2287 err:
2288 	exitcode = (int)MANDOCLEVEL_SYSERR;
2289 	say(MANDOC_DB, "Data changed, but cannot replace database");
2290 
2291 out:
2292 	if (cp1 != MAP_FAILED)
2293 		munmap(cp1, sb1.st_size);
2294 	if (cp2 != MAP_FAILED)
2295 		munmap(cp2, sb2.st_size);
2296 	if (fd1 != -1)
2297 		close(fd1);
2298 	if (fd2 != -1)
2299 		close(fd2);
2300 	unlink(tfn);
2301 	*strrchr(tfn, '/') = '\0';
2302 	rmdir(tfn);
2303 }
2304 
2305 static int
2306 set_basedir(const char *targetdir, int report_baddir)
2307 {
2308 	static char	 startdir[PATH_MAX];
2309 	static int	 getcwd_status;  /* 1 = ok, 2 = failure */
2310 	static int	 chdir_status;  /* 1 = changed directory */
2311 
2312 	/*
2313 	 * Remember the original working directory, if possible.
2314 	 * This will be needed if the second or a later directory
2315 	 * on the command line is given as a relative path.
2316 	 * Do not error out if the current directory is not
2317 	 * searchable: Maybe it won't be needed after all.
2318 	 */
2319 	if (getcwd_status == 0) {
2320 		if (getcwd(startdir, sizeof(startdir)) == NULL) {
2321 			getcwd_status = 2;
2322 			(void)strlcpy(startdir, strerror(errno),
2323 			    sizeof(startdir));
2324 		} else
2325 			getcwd_status = 1;
2326 	}
2327 
2328 	/*
2329 	 * We are leaving the old base directory.
2330 	 * Do not use it any longer, not even for messages.
2331 	 */
2332 	*basedir = '\0';
2333 	basedir_len = 0;
2334 
2335 	/*
2336 	 * If and only if the directory was changed earlier and
2337 	 * the next directory to process is given as a relative path,
2338 	 * first go back, or bail out if that is impossible.
2339 	 */
2340 	if (chdir_status && *targetdir != '/') {
2341 		if (getcwd_status == 2) {
2342 			exitcode = (int)MANDOCLEVEL_SYSERR;
2343 			say("", "getcwd: %s", startdir);
2344 			return 0;
2345 		}
2346 		if (chdir(startdir) == -1) {
2347 			exitcode = (int)MANDOCLEVEL_SYSERR;
2348 			say("", "&chdir %s", startdir);
2349 			return 0;
2350 		}
2351 	}
2352 
2353 	/*
2354 	 * Always resolve basedir to the canonicalized absolute
2355 	 * pathname and append a trailing slash, such that
2356 	 * we can reliably check whether files are inside.
2357 	 */
2358 	if (realpath(targetdir, basedir) == NULL) {
2359 		if (report_baddir || errno != ENOENT) {
2360 			exitcode = (int)MANDOCLEVEL_BADARG;
2361 			say("", "&%s: realpath", targetdir);
2362 		}
2363 		*basedir = '\0';
2364 		return 0;
2365 	} else if (chdir(basedir) == -1) {
2366 		if (report_baddir || errno != ENOENT) {
2367 			exitcode = (int)MANDOCLEVEL_BADARG;
2368 			say("", "&chdir");
2369 		}
2370 		*basedir = '\0';
2371 		return 0;
2372 	}
2373 	chdir_status = 1;
2374 	basedir_len = strlen(basedir);
2375 	if (basedir[basedir_len - 1] != '/') {
2376 		if (basedir_len >= PATH_MAX - 1) {
2377 			exitcode = (int)MANDOCLEVEL_SYSERR;
2378 			say("", "Filename too long");
2379 			*basedir = '\0';
2380 			basedir_len = 0;
2381 			return 0;
2382 		}
2383 		basedir[basedir_len++] = '/';
2384 		basedir[basedir_len] = '\0';
2385 	}
2386 	return 1;
2387 }
2388 
2389 #ifdef READ_ALLOWED_PATH
2390 static int
2391 read_allowed(const char *candidate)
2392 {
2393 	const char	*cp;
2394 	size_t		 len;
2395 
2396 	for (cp = READ_ALLOWED_PATH;; cp += len) {
2397 		while (*cp == ':')
2398 			cp++;
2399 		if (*cp == '\0')
2400 			return 0;
2401 		len = strcspn(cp, ":");
2402 		if (strncmp(candidate, cp, len) == 0)
2403 			return 1;
2404 	}
2405 }
2406 #endif
2407 
2408 static void
2409 say(const char *file, const char *format, ...)
2410 {
2411 	va_list		 ap;
2412 	int		 use_errno;
2413 
2414 	if (*basedir != '\0')
2415 		fprintf(stderr, "%s", basedir);
2416 	if (*basedir != '\0' && *file != '\0')
2417 		fputc('/', stderr);
2418 	if (*file != '\0')
2419 		fprintf(stderr, "%s", file);
2420 
2421 	use_errno = 1;
2422 	if (format != NULL) {
2423 		switch (*format) {
2424 		case '&':
2425 			format++;
2426 			break;
2427 		case '\0':
2428 			format = NULL;
2429 			break;
2430 		default:
2431 			use_errno = 0;
2432 			break;
2433 		}
2434 	}
2435 	if (format != NULL) {
2436 		if (*basedir != '\0' || *file != '\0')
2437 			fputs(": ", stderr);
2438 		va_start(ap, format);
2439 		vfprintf(stderr, format, ap);
2440 		va_end(ap);
2441 	}
2442 	if (use_errno) {
2443 		if (*basedir != '\0' || *file != '\0' || format != NULL)
2444 			fputs(": ", stderr);
2445 		perror(NULL);
2446 	} else
2447 		fputc('\n', stderr);
2448 }
2449