xref: /illumos-gate/usr/src/cmd/mandoc/mandocdb.c (revision 15c07adc1c7b828006b5e3c4d528b92229d6bd23)
1 /*	$Id: mandocdb.c,v 1.258 2018/02/23 18:25:57 schwarze Exp $ */
2 /*
3  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
4  * Copyright (c) 2011-2017 Ingo Schwarze <schwarze@openbsd.org>
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 #include "config.h"
20 
21 #include <sys/types.h>
22 #include <sys/mman.h>
23 #include <sys/stat.h>
24 
25 #include <assert.h>
26 #include <ctype.h>
27 #if HAVE_ERR
28 #include <err.h>
29 #endif
30 #include <errno.h>
31 #include <fcntl.h>
32 #if HAVE_FTS
33 #include <fts.h>
34 #else
35 #include "compat_fts.h"
36 #endif
37 #include <limits.h>
38 #if HAVE_SANDBOX_INIT
39 #include <sandbox.h>
40 #endif
41 #include <stdarg.h>
42 #include <stddef.h>
43 #include <stdio.h>
44 #include <stdint.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #include "mandoc_aux.h"
50 #include "mandoc_ohash.h"
51 #include "mandoc.h"
52 #include "roff.h"
53 #include "mdoc.h"
54 #include "man.h"
55 #include "manconf.h"
56 #include "mansearch.h"
57 #include "dba_array.h"
58 #include "dba.h"
59 
60 extern const char *const mansearch_keynames[];
61 
62 enum	op {
63 	OP_DEFAULT = 0, /* new dbs from dir list or default config */
64 	OP_CONFFILE, /* new databases from custom config file */
65 	OP_UPDATE, /* delete/add entries in existing database */
66 	OP_DELETE, /* delete entries from existing database */
67 	OP_TEST /* change no databases, report potential problems */
68 };
69 
70 struct	str {
71 	const struct mpage *mpage; /* if set, the owning parse */
72 	uint64_t	 mask; /* bitmask in sequence */
73 	char		 key[]; /* rendered text */
74 };
75 
76 struct	inodev {
77 	ino_t		 st_ino;
78 	dev_t		 st_dev;
79 };
80 
81 struct	mpage {
82 	struct inodev	 inodev;  /* used for hashing routine */
83 	struct dba_array *dba;
84 	char		*sec;     /* section from file content */
85 	char		*arch;    /* architecture from file content */
86 	char		*title;   /* title from file content */
87 	char		*desc;    /* description from file content */
88 	struct mpage	*next;    /* singly linked list */
89 	struct mlink	*mlinks;  /* singly linked list */
90 	int		 name_head_done;
91 	enum form	 form;    /* format from file content */
92 };
93 
94 struct	mlink {
95 	char		 file[PATH_MAX]; /* filename rel. to manpath */
96 	char		*dsec;    /* section from directory */
97 	char		*arch;    /* architecture from directory */
98 	char		*name;    /* name from file name (not empty) */
99 	char		*fsec;    /* section from file name suffix */
100 	struct mlink	*next;    /* singly linked list */
101 	struct mpage	*mpage;   /* parent */
102 	int		 gzip;	  /* filename has a .gz suffix */
103 	enum form	 dform;   /* format from directory */
104 	enum form	 fform;   /* format from file name suffix */
105 };
106 
107 typedef	int (*mdoc_fp)(struct mpage *, const struct roff_meta *,
108 			const struct roff_node *);
109 
110 struct	mdoc_handler {
111 	mdoc_fp		 fp; /* optional handler */
112 	uint64_t	 mask;  /* set unless handler returns 0 */
113 	int		 taboo;  /* node flags that must not be set */
114 };
115 
116 
117 int		 mandocdb(int, char *[]);
118 
119 static	void	 dbadd(struct dba *, struct mpage *);
120 static	void	 dbadd_mlink(const struct mlink *mlink);
121 static	void	 dbprune(struct dba *);
122 static	void	 dbwrite(struct dba *);
123 static	void	 filescan(const char *);
124 #if HAVE_FTS_COMPARE_CONST
125 static	int	 fts_compare(const FTSENT *const *, const FTSENT *const *);
126 #else
127 static	int	 fts_compare(const FTSENT **, const FTSENT **);
128 #endif
129 static	void	 mlink_add(struct mlink *, const struct stat *);
130 static	void	 mlink_check(struct mpage *, struct mlink *);
131 static	void	 mlink_free(struct mlink *);
132 static	void	 mlinks_undupe(struct mpage *);
133 static	void	 mpages_free(void);
134 static	void	 mpages_merge(struct dba *, struct mparse *);
135 static	void	 parse_cat(struct mpage *, int);
136 static	void	 parse_man(struct mpage *, const struct roff_meta *,
137 			const struct roff_node *);
138 static	void	 parse_mdoc(struct mpage *, const struct roff_meta *,
139 			const struct roff_node *);
140 static	int	 parse_mdoc_head(struct mpage *, const struct roff_meta *,
141 			const struct roff_node *);
142 static	int	 parse_mdoc_Fa(struct mpage *, const struct roff_meta *,
143 			const struct roff_node *);
144 static	int	 parse_mdoc_Fd(struct mpage *, const struct roff_meta *,
145 			const struct roff_node *);
146 static	void	 parse_mdoc_fname(struct mpage *, const struct roff_node *);
147 static	int	 parse_mdoc_Fn(struct mpage *, const struct roff_meta *,
148 			const struct roff_node *);
149 static	int	 parse_mdoc_Fo(struct mpage *, const struct roff_meta *,
150 			const struct roff_node *);
151 static	int	 parse_mdoc_Nd(struct mpage *, const struct roff_meta *,
152 			const struct roff_node *);
153 static	int	 parse_mdoc_Nm(struct mpage *, const struct roff_meta *,
154 			const struct roff_node *);
155 static	int	 parse_mdoc_Sh(struct mpage *, const struct roff_meta *,
156 			const struct roff_node *);
157 static	int	 parse_mdoc_Va(struct mpage *, const struct roff_meta *,
158 			const struct roff_node *);
159 static	int	 parse_mdoc_Xr(struct mpage *, const struct roff_meta *,
160 			const struct roff_node *);
161 static	void	 putkey(const struct mpage *, char *, uint64_t);
162 static	void	 putkeys(const struct mpage *, char *, size_t, uint64_t);
163 static	void	 putmdockey(const struct mpage *,
164 			const struct roff_node *, uint64_t, int);
165 static	int	 render_string(char **, size_t *);
166 static	void	 say(const char *, const char *, ...)
167 			__attribute__((__format__ (__printf__, 2, 3)));
168 static	int	 set_basedir(const char *, int);
169 static	int	 treescan(void);
170 static	size_t	 utf8(unsigned int, char [7]);
171 
172 static	int		 nodb; /* no database changes */
173 static	int		 mparse_options; /* abort the parse early */
174 static	int		 use_all; /* use all found files */
175 static	int		 debug; /* print what we're doing */
176 static	int		 warnings; /* warn about crap */
177 static	int		 write_utf8; /* write UTF-8 output; else ASCII */
178 static	int		 exitcode; /* to be returned by main */
179 static	enum op		 op; /* operational mode */
180 static	char		 basedir[PATH_MAX]; /* current base directory */
181 static	struct mpage	*mpage_head; /* list of distinct manual pages */
182 static	struct ohash	 mpages; /* table of distinct manual pages */
183 static	struct ohash	 mlinks; /* table of directory entries */
184 static	struct ohash	 names; /* table of all names */
185 static	struct ohash	 strings; /* table of all strings */
186 static	uint64_t	 name_mask;
187 
188 static	const struct mdoc_handler __mdocs[MDOC_MAX - MDOC_Dd] = {
189 	{ NULL, 0, NODE_NOPRT },  /* Dd */
190 	{ NULL, 0, NODE_NOPRT },  /* Dt */
191 	{ NULL, 0, NODE_NOPRT },  /* Os */
192 	{ parse_mdoc_Sh, TYPE_Sh, 0 }, /* Sh */
193 	{ parse_mdoc_head, TYPE_Ss, 0 }, /* Ss */
194 	{ NULL, 0, 0 },  /* Pp */
195 	{ NULL, 0, 0 },  /* D1 */
196 	{ NULL, 0, 0 },  /* Dl */
197 	{ NULL, 0, 0 },  /* Bd */
198 	{ NULL, 0, 0 },  /* Ed */
199 	{ NULL, 0, 0 },  /* Bl */
200 	{ NULL, 0, 0 },  /* El */
201 	{ NULL, 0, 0 },  /* It */
202 	{ NULL, 0, 0 },  /* Ad */
203 	{ NULL, TYPE_An, 0 },  /* An */
204 	{ NULL, 0, 0 },  /* Ap */
205 	{ NULL, TYPE_Ar, 0 },  /* Ar */
206 	{ NULL, TYPE_Cd, 0 },  /* Cd */
207 	{ NULL, TYPE_Cm, 0 },  /* Cm */
208 	{ NULL, TYPE_Dv, 0 },  /* Dv */
209 	{ NULL, TYPE_Er, 0 },  /* Er */
210 	{ NULL, TYPE_Ev, 0 },  /* Ev */
211 	{ NULL, 0, 0 },  /* Ex */
212 	{ parse_mdoc_Fa, 0, 0 },  /* Fa */
213 	{ parse_mdoc_Fd, 0, 0 },  /* Fd */
214 	{ NULL, TYPE_Fl, 0 },  /* Fl */
215 	{ parse_mdoc_Fn, 0, 0 },  /* Fn */
216 	{ NULL, TYPE_Ft | TYPE_Vt, 0 },  /* Ft */
217 	{ NULL, TYPE_Ic, 0 },  /* Ic */
218 	{ NULL, TYPE_In, 0 },  /* In */
219 	{ NULL, TYPE_Li, 0 },  /* Li */
220 	{ parse_mdoc_Nd, 0, 0 },  /* Nd */
221 	{ parse_mdoc_Nm, 0, 0 },  /* Nm */
222 	{ NULL, 0, 0 },  /* Op */
223 	{ NULL, 0, 0 },  /* Ot */
224 	{ NULL, TYPE_Pa, NODE_NOSRC },  /* Pa */
225 	{ NULL, 0, 0 },  /* Rv */
226 	{ NULL, TYPE_St, 0 },  /* St */
227 	{ parse_mdoc_Va, TYPE_Va, 0 },  /* Va */
228 	{ parse_mdoc_Va, TYPE_Vt, 0 },  /* Vt */
229 	{ parse_mdoc_Xr, 0, 0 },  /* Xr */
230 	{ NULL, 0, 0 },  /* %A */
231 	{ NULL, 0, 0 },  /* %B */
232 	{ NULL, 0, 0 },  /* %D */
233 	{ NULL, 0, 0 },  /* %I */
234 	{ NULL, 0, 0 },  /* %J */
235 	{ NULL, 0, 0 },  /* %N */
236 	{ NULL, 0, 0 },  /* %O */
237 	{ NULL, 0, 0 },  /* %P */
238 	{ NULL, 0, 0 },  /* %R */
239 	{ NULL, 0, 0 },  /* %T */
240 	{ NULL, 0, 0 },  /* %V */
241 	{ NULL, 0, 0 },  /* Ac */
242 	{ NULL, 0, 0 },  /* Ao */
243 	{ NULL, 0, 0 },  /* Aq */
244 	{ NULL, TYPE_At, 0 },  /* At */
245 	{ NULL, 0, 0 },  /* Bc */
246 	{ NULL, 0, 0 },  /* Bf */
247 	{ NULL, 0, 0 },  /* Bo */
248 	{ NULL, 0, 0 },  /* Bq */
249 	{ NULL, TYPE_Bsx, NODE_NOSRC },  /* Bsx */
250 	{ NULL, TYPE_Bx, NODE_NOSRC },  /* Bx */
251 	{ NULL, 0, 0 },  /* Db */
252 	{ NULL, 0, 0 },  /* Dc */
253 	{ NULL, 0, 0 },  /* Do */
254 	{ NULL, 0, 0 },  /* Dq */
255 	{ NULL, 0, 0 },  /* Ec */
256 	{ NULL, 0, 0 },  /* Ef */
257 	{ NULL, TYPE_Em, 0 },  /* Em */
258 	{ NULL, 0, 0 },  /* Eo */
259 	{ NULL, TYPE_Fx, NODE_NOSRC },  /* Fx */
260 	{ NULL, TYPE_Ms, 0 },  /* Ms */
261 	{ NULL, 0, 0 },  /* No */
262 	{ NULL, 0, 0 },  /* Ns */
263 	{ NULL, TYPE_Nx, NODE_NOSRC },  /* Nx */
264 	{ NULL, TYPE_Ox, NODE_NOSRC },  /* Ox */
265 	{ NULL, 0, 0 },  /* Pc */
266 	{ NULL, 0, 0 },  /* Pf */
267 	{ NULL, 0, 0 },  /* Po */
268 	{ NULL, 0, 0 },  /* Pq */
269 	{ NULL, 0, 0 },  /* Qc */
270 	{ NULL, 0, 0 },  /* Ql */
271 	{ NULL, 0, 0 },  /* Qo */
272 	{ NULL, 0, 0 },  /* Qq */
273 	{ NULL, 0, 0 },  /* Re */
274 	{ NULL, 0, 0 },  /* Rs */
275 	{ NULL, 0, 0 },  /* Sc */
276 	{ NULL, 0, 0 },  /* So */
277 	{ NULL, 0, 0 },  /* Sq */
278 	{ NULL, 0, 0 },  /* Sm */
279 	{ NULL, 0, 0 },  /* Sx */
280 	{ NULL, TYPE_Sy, 0 },  /* Sy */
281 	{ NULL, TYPE_Tn, 0 },  /* Tn */
282 	{ NULL, 0, NODE_NOSRC },  /* Ux */
283 	{ NULL, 0, 0 },  /* Xc */
284 	{ NULL, 0, 0 },  /* Xo */
285 	{ parse_mdoc_Fo, 0, 0 },  /* Fo */
286 	{ NULL, 0, 0 },  /* Fc */
287 	{ NULL, 0, 0 },  /* Oo */
288 	{ NULL, 0, 0 },  /* Oc */
289 	{ NULL, 0, 0 },  /* Bk */
290 	{ NULL, 0, 0 },  /* Ek */
291 	{ NULL, 0, 0 },  /* Bt */
292 	{ NULL, 0, 0 },  /* Hf */
293 	{ NULL, 0, 0 },  /* Fr */
294 	{ NULL, 0, 0 },  /* Ud */
295 	{ NULL, TYPE_Lb, NODE_NOSRC },  /* Lb */
296 	{ NULL, 0, 0 },  /* Lp */
297 	{ NULL, TYPE_Lk, 0 },  /* Lk */
298 	{ NULL, TYPE_Mt, NODE_NOSRC },  /* Mt */
299 	{ NULL, 0, 0 },  /* Brq */
300 	{ NULL, 0, 0 },  /* Bro */
301 	{ NULL, 0, 0 },  /* Brc */
302 	{ NULL, 0, 0 },  /* %C */
303 	{ NULL, 0, 0 },  /* Es */
304 	{ NULL, 0, 0 },  /* En */
305 	{ NULL, TYPE_Dx, NODE_NOSRC },  /* Dx */
306 	{ NULL, 0, 0 },  /* %Q */
307 	{ NULL, 0, 0 },  /* %U */
308 	{ NULL, 0, 0 },  /* Ta */
309 };
310 static	const struct mdoc_handler *const mdocs = __mdocs - MDOC_Dd;
311 
312 
313 int
314 mandocdb(int argc, char *argv[])
315 {
316 	struct manconf	  conf;
317 	struct mparse	 *mp;
318 	struct dba	 *dba;
319 	const char	 *path_arg, *progname;
320 	size_t		  j, sz;
321 	int		  ch, i;
322 
323 #if HAVE_PLEDGE
324 	if (pledge("stdio rpath wpath cpath", NULL) == -1) {
325 		warn("pledge");
326 		return (int)MANDOCLEVEL_SYSERR;
327 	}
328 #endif
329 
330 #if HAVE_SANDBOX_INIT
331 	if (sandbox_init(kSBXProfileNoInternet, SANDBOX_NAMED, NULL) == -1) {
332 		warnx("sandbox_init");
333 		return (int)MANDOCLEVEL_SYSERR;
334 	}
335 #endif
336 
337 	memset(&conf, 0, sizeof(conf));
338 
339 	/*
340 	 * We accept a few different invocations.
341 	 * The CHECKOP macro makes sure that invocation styles don't
342 	 * clobber each other.
343 	 */
344 #define	CHECKOP(_op, _ch) do \
345 	if (OP_DEFAULT != (_op)) { \
346 		warnx("-%c: Conflicting option", (_ch)); \
347 		goto usage; \
348 	} while (/*CONSTCOND*/0)
349 
350 	path_arg = NULL;
351 	op = OP_DEFAULT;
352 
353 	while (-1 != (ch = getopt(argc, argv, "aC:Dd:npQT:tu:v")))
354 		switch (ch) {
355 		case 'a':
356 			use_all = 1;
357 			break;
358 		case 'C':
359 			CHECKOP(op, ch);
360 			path_arg = optarg;
361 			op = OP_CONFFILE;
362 			break;
363 		case 'D':
364 			debug++;
365 			break;
366 		case 'd':
367 			CHECKOP(op, ch);
368 			path_arg = optarg;
369 			op = OP_UPDATE;
370 			break;
371 		case 'n':
372 			nodb = 1;
373 			break;
374 		case 'p':
375 			warnings = 1;
376 			break;
377 		case 'Q':
378 			mparse_options |= MPARSE_QUICK;
379 			break;
380 		case 'T':
381 			if (strcmp(optarg, "utf8")) {
382 				warnx("-T%s: Unsupported output format",
383 				    optarg);
384 				goto usage;
385 			}
386 			write_utf8 = 1;
387 			break;
388 		case 't':
389 			CHECKOP(op, ch);
390 			dup2(STDOUT_FILENO, STDERR_FILENO);
391 			op = OP_TEST;
392 			nodb = warnings = 1;
393 			break;
394 		case 'u':
395 			CHECKOP(op, ch);
396 			path_arg = optarg;
397 			op = OP_DELETE;
398 			break;
399 		case 'v':
400 			/* Compatibility with espie@'s makewhatis. */
401 			break;
402 		default:
403 			goto usage;
404 		}
405 
406 	argc -= optind;
407 	argv += optind;
408 
409 #if HAVE_PLEDGE
410 	if (nodb) {
411 		if (pledge("stdio rpath", NULL) == -1) {
412 			warn("pledge");
413 			return (int)MANDOCLEVEL_SYSERR;
414 		}
415 	}
416 #endif
417 
418 	if (OP_CONFFILE == op && argc > 0) {
419 		warnx("-C: Too many arguments");
420 		goto usage;
421 	}
422 
423 	exitcode = (int)MANDOCLEVEL_OK;
424 	mchars_alloc();
425 	mp = mparse_alloc(mparse_options, MANDOCERR_MAX, NULL,
426 	    MANDOC_OS_OTHER, NULL);
427 	mandoc_ohash_init(&mpages, 6, offsetof(struct mpage, inodev));
428 	mandoc_ohash_init(&mlinks, 6, offsetof(struct mlink, file));
429 
430 	if (OP_UPDATE == op || OP_DELETE == op || OP_TEST == op) {
431 
432 		/*
433 		 * Most of these deal with a specific directory.
434 		 * Jump into that directory first.
435 		 */
436 		if (OP_TEST != op && 0 == set_basedir(path_arg, 1))
437 			goto out;
438 
439 		dba = nodb ? dba_new(128) : dba_read(MANDOC_DB);
440 		if (dba != NULL) {
441 			/*
442 			 * The existing database is usable.  Process
443 			 * all files specified on the command-line.
444 			 */
445 			use_all = 1;
446 			for (i = 0; i < argc; i++)
447 				filescan(argv[i]);
448 			if (nodb == 0)
449 				dbprune(dba);
450 		} else {
451 			/* Database missing or corrupt. */
452 			if (op != OP_UPDATE || errno != ENOENT)
453 				say(MANDOC_DB, "%s: Automatically recreating"
454 				    " from scratch", strerror(errno));
455 			exitcode = (int)MANDOCLEVEL_OK;
456 			op = OP_DEFAULT;
457 			if (0 == treescan())
458 				goto out;
459 			dba = dba_new(128);
460 		}
461 		if (OP_DELETE != op)
462 			mpages_merge(dba, mp);
463 		if (nodb == 0)
464 			dbwrite(dba);
465 		dba_free(dba);
466 	} else {
467 		/*
468 		 * If we have arguments, use them as our manpaths.
469 		 * If we don't, use man.conf(5).
470 		 */
471 		if (argc > 0) {
472 			conf.manpath.paths = mandoc_reallocarray(NULL,
473 			    argc, sizeof(char *));
474 			conf.manpath.sz = (size_t)argc;
475 			for (i = 0; i < argc; i++)
476 				conf.manpath.paths[i] = mandoc_strdup(argv[i]);
477 		} else
478 			manconf_parse(&conf, path_arg, NULL, NULL);
479 
480 		if (conf.manpath.sz == 0) {
481 			exitcode = (int)MANDOCLEVEL_BADARG;
482 			say("", "Empty manpath");
483 		}
484 
485 		/*
486 		 * First scan the tree rooted at a base directory, then
487 		 * build a new database and finally move it into place.
488 		 * Ignore zero-length directories and strip trailing
489 		 * slashes.
490 		 */
491 		for (j = 0; j < conf.manpath.sz; j++) {
492 			sz = strlen(conf.manpath.paths[j]);
493 			if (sz && conf.manpath.paths[j][sz - 1] == '/')
494 				conf.manpath.paths[j][--sz] = '\0';
495 			if (0 == sz)
496 				continue;
497 
498 			if (j) {
499 				mandoc_ohash_init(&mpages, 6,
500 				    offsetof(struct mpage, inodev));
501 				mandoc_ohash_init(&mlinks, 6,
502 				    offsetof(struct mlink, file));
503 			}
504 
505 			if ( ! set_basedir(conf.manpath.paths[j], argc > 0))
506 				continue;
507 			if (0 == treescan())
508 				continue;
509 			dba = dba_new(128);
510 			mpages_merge(dba, mp);
511 			if (nodb == 0)
512 				dbwrite(dba);
513 			dba_free(dba);
514 
515 			if (j + 1 < conf.manpath.sz) {
516 				mpages_free();
517 				ohash_delete(&mpages);
518 				ohash_delete(&mlinks);
519 			}
520 		}
521 	}
522 out:
523 	manconf_free(&conf);
524 	mparse_free(mp);
525 	mchars_free();
526 	mpages_free();
527 	ohash_delete(&mpages);
528 	ohash_delete(&mlinks);
529 	return exitcode;
530 usage:
531 	progname = getprogname();
532 	fprintf(stderr, "usage: %s [-aDnpQ] [-C file] [-Tutf8]\n"
533 			"       %s [-aDnpQ] [-Tutf8] dir ...\n"
534 			"       %s [-DnpQ] [-Tutf8] -d dir [file ...]\n"
535 			"       %s [-Dnp] -u dir [file ...]\n"
536 			"       %s [-Q] -t file ...\n",
537 		        progname, progname, progname, progname, progname);
538 
539 	return (int)MANDOCLEVEL_BADARG;
540 }
541 
542 /*
543  * To get a singly linked list in alpha order while inserting entries
544  * at the beginning, process directory entries in reverse alpha order.
545  */
546 static int
547 #if HAVE_FTS_COMPARE_CONST
548 fts_compare(const FTSENT *const *a, const FTSENT *const *b)
549 #else
550 fts_compare(const FTSENT **a, const FTSENT **b)
551 #endif
552 {
553 	return -strcmp((*a)->fts_name, (*b)->fts_name);
554 }
555 
556 /*
557  * Scan a directory tree rooted at "basedir" for manpages.
558  * We use fts(), scanning directory parts along the way for clues to our
559  * section and architecture.
560  *
561  * If use_all has been specified, grok all files.
562  * If not, sanitise paths to the following:
563  *
564  *   [./]man*[/<arch>]/<name>.<section>
565  *   or
566  *   [./]cat<section>[/<arch>]/<name>.0
567  *
568  * TODO: accommodate for multi-language directories.
569  */
570 static int
571 treescan(void)
572 {
573 	char		 buf[PATH_MAX];
574 	FTS		*f;
575 	FTSENT		*ff;
576 	struct mlink	*mlink;
577 	int		 gzip;
578 	enum form	 dform;
579 	char		*dsec, *arch, *fsec, *cp;
580 	const char	*path;
581 	const char	*argv[2];
582 
583 	argv[0] = ".";
584 	argv[1] = NULL;
585 
586 	f = fts_open((char * const *)argv, FTS_PHYSICAL | FTS_NOCHDIR,
587 	    fts_compare);
588 	if (f == NULL) {
589 		exitcode = (int)MANDOCLEVEL_SYSERR;
590 		say("", "&fts_open");
591 		return 0;
592 	}
593 
594 	dsec = arch = NULL;
595 	dform = FORM_NONE;
596 
597 	while ((ff = fts_read(f)) != NULL) {
598 		path = ff->fts_path + 2;
599 		switch (ff->fts_info) {
600 
601 		/*
602 		 * Symbolic links require various sanity checks,
603 		 * then get handled just like regular files.
604 		 */
605 		case FTS_SL:
606 			if (realpath(path, buf) == NULL) {
607 				if (warnings)
608 					say(path, "&realpath");
609 				continue;
610 			}
611 			if (strstr(buf, basedir) != buf
612 #ifdef HOMEBREWDIR
613 			    && strstr(buf, HOMEBREWDIR) != buf
614 #endif
615 			) {
616 				if (warnings) say("",
617 				    "%s: outside base directory", buf);
618 				continue;
619 			}
620 			/* Use logical inode to avoid mpages dupe. */
621 			if (stat(path, ff->fts_statp) == -1) {
622 				if (warnings)
623 					say(path, "&stat");
624 				continue;
625 			}
626 			/* FALLTHROUGH */
627 
628 		/*
629 		 * If we're a regular file, add an mlink by using the
630 		 * stored directory data and handling the filename.
631 		 */
632 		case FTS_F:
633 			if ( ! strcmp(path, MANDOC_DB))
634 				continue;
635 			if ( ! use_all && ff->fts_level < 2) {
636 				if (warnings)
637 					say(path, "Extraneous file");
638 				continue;
639 			}
640 			gzip = 0;
641 			fsec = NULL;
642 			while (fsec == NULL) {
643 				fsec = strrchr(ff->fts_name, '.');
644 				if (fsec == NULL || strcmp(fsec+1, "gz"))
645 					break;
646 				gzip = 1;
647 				*fsec = '\0';
648 				fsec = NULL;
649 			}
650 			if (fsec == NULL) {
651 				if ( ! use_all) {
652 					if (warnings)
653 						say(path,
654 						    "No filename suffix");
655 					continue;
656 				}
657 			} else if ( ! strcmp(++fsec, "html")) {
658 				if (warnings)
659 					say(path, "Skip html");
660 				continue;
661 			} else if ( ! strcmp(fsec, "ps")) {
662 				if (warnings)
663 					say(path, "Skip ps");
664 				continue;
665 			} else if ( ! strcmp(fsec, "pdf")) {
666 				if (warnings)
667 					say(path, "Skip pdf");
668 				continue;
669 			} else if ( ! use_all &&
670 			    ((dform == FORM_SRC &&
671 			      strncmp(fsec, dsec, strlen(dsec))) ||
672 			     (dform == FORM_CAT && strcmp(fsec, "0")))) {
673 				if (warnings)
674 					say(path, "Wrong filename suffix");
675 				continue;
676 			} else
677 				fsec[-1] = '\0';
678 
679 			mlink = mandoc_calloc(1, sizeof(struct mlink));
680 			if (strlcpy(mlink->file, path,
681 			    sizeof(mlink->file)) >=
682 			    sizeof(mlink->file)) {
683 				say(path, "Filename too long");
684 				free(mlink);
685 				continue;
686 			}
687 			mlink->dform = dform;
688 			mlink->dsec = dsec;
689 			mlink->arch = arch;
690 			mlink->name = ff->fts_name;
691 			mlink->fsec = fsec;
692 			mlink->gzip = gzip;
693 			mlink_add(mlink, ff->fts_statp);
694 			continue;
695 
696 		case FTS_D:
697 		case FTS_DP:
698 			break;
699 
700 		default:
701 			if (warnings)
702 				say(path, "Not a regular file");
703 			continue;
704 		}
705 
706 		switch (ff->fts_level) {
707 		case 0:
708 			/* Ignore the root directory. */
709 			break;
710 		case 1:
711 			/*
712 			 * This might contain manX/ or catX/.
713 			 * Try to infer this from the name.
714 			 * If we're not in use_all, enforce it.
715 			 */
716 			cp = ff->fts_name;
717 			if (ff->fts_info == FTS_DP) {
718 				dform = FORM_NONE;
719 				dsec = NULL;
720 				break;
721 			}
722 
723 			if ( ! strncmp(cp, "man", 3)) {
724 				dform = FORM_SRC;
725 				dsec = cp + 3;
726 			} else if ( ! strncmp(cp, "cat", 3)) {
727 				dform = FORM_CAT;
728 				dsec = cp + 3;
729 			} else {
730 				dform = FORM_NONE;
731 				dsec = NULL;
732 			}
733 
734 			if (dsec != NULL || use_all)
735 				break;
736 
737 			if (warnings)
738 				say(path, "Unknown directory part");
739 			fts_set(f, ff, FTS_SKIP);
740 			break;
741 		case 2:
742 			/*
743 			 * Possibly our architecture.
744 			 * If we're descending, keep tabs on it.
745 			 */
746 			if (ff->fts_info != FTS_DP && dsec != NULL)
747 				arch = ff->fts_name;
748 			else
749 				arch = NULL;
750 			break;
751 		default:
752 			if (ff->fts_info == FTS_DP || use_all)
753 				break;
754 			if (warnings)
755 				say(path, "Extraneous directory part");
756 			fts_set(f, ff, FTS_SKIP);
757 			break;
758 		}
759 	}
760 
761 	fts_close(f);
762 	return 1;
763 }
764 
765 /*
766  * Add a file to the mlinks table.
767  * Do not verify that it's a "valid" looking manpage (we'll do that
768  * later).
769  *
770  * Try to infer the manual section, architecture, and page name from the
771  * path, assuming it looks like
772  *
773  *   [./]man*[/<arch>]/<name>.<section>
774  *   or
775  *   [./]cat<section>[/<arch>]/<name>.0
776  *
777  * See treescan() for the fts(3) version of this.
778  */
779 static void
780 filescan(const char *file)
781 {
782 	char		 buf[PATH_MAX];
783 	struct stat	 st;
784 	struct mlink	*mlink;
785 	char		*p, *start;
786 
787 	assert(use_all);
788 
789 	if (0 == strncmp(file, "./", 2))
790 		file += 2;
791 
792 	/*
793 	 * We have to do lstat(2) before realpath(3) loses
794 	 * the information whether this is a symbolic link.
795 	 * We need to know that because for symbolic links,
796 	 * we want to use the orginal file name, while for
797 	 * regular files, we want to use the real path.
798 	 */
799 	if (-1 == lstat(file, &st)) {
800 		exitcode = (int)MANDOCLEVEL_BADARG;
801 		say(file, "&lstat");
802 		return;
803 	} else if (0 == ((S_IFREG | S_IFLNK) & st.st_mode)) {
804 		exitcode = (int)MANDOCLEVEL_BADARG;
805 		say(file, "Not a regular file");
806 		return;
807 	}
808 
809 	/*
810 	 * We have to resolve the file name to the real path
811 	 * in any case for the base directory check.
812 	 */
813 	if (NULL == realpath(file, buf)) {
814 		exitcode = (int)MANDOCLEVEL_BADARG;
815 		say(file, "&realpath");
816 		return;
817 	}
818 
819 	if (OP_TEST == op)
820 		start = buf;
821 	else if (strstr(buf, basedir) == buf)
822 		start = buf + strlen(basedir);
823 #ifdef HOMEBREWDIR
824 	else if (strstr(buf, HOMEBREWDIR) == buf)
825 		start = buf;
826 #endif
827 	else {
828 		exitcode = (int)MANDOCLEVEL_BADARG;
829 		say("", "%s: outside base directory", buf);
830 		return;
831 	}
832 
833 	/*
834 	 * Now we are sure the file is inside our tree.
835 	 * If it is a symbolic link, ignore the real path
836 	 * and use the original name.
837 	 * This implies passing stuff like "cat1/../man1/foo.1"
838 	 * on the command line won't work.  So don't do that.
839 	 * Note the stat(2) can still fail if the link target
840 	 * doesn't exist.
841 	 */
842 	if (S_IFLNK & st.st_mode) {
843 		if (-1 == stat(buf, &st)) {
844 			exitcode = (int)MANDOCLEVEL_BADARG;
845 			say(file, "&stat");
846 			return;
847 		}
848 		if (strlcpy(buf, file, sizeof(buf)) >= sizeof(buf)) {
849 			say(file, "Filename too long");
850 			return;
851 		}
852 		start = buf;
853 		if (OP_TEST != op && strstr(buf, basedir) == buf)
854 			start += strlen(basedir);
855 	}
856 
857 	mlink = mandoc_calloc(1, sizeof(struct mlink));
858 	mlink->dform = FORM_NONE;
859 	if (strlcpy(mlink->file, start, sizeof(mlink->file)) >=
860 	    sizeof(mlink->file)) {
861 		say(start, "Filename too long");
862 		free(mlink);
863 		return;
864 	}
865 
866 	/*
867 	 * In test mode or when the original name is absolute
868 	 * but outside our tree, guess the base directory.
869 	 */
870 
871 	if (op == OP_TEST || (start == buf && *start == '/')) {
872 		if (strncmp(buf, "man/", 4) == 0)
873 			start = buf + 4;
874 		else if ((start = strstr(buf, "/man/")) != NULL)
875 			start += 5;
876 		else
877 			start = buf;
878 	}
879 
880 	/*
881 	 * First try to guess our directory structure.
882 	 * If we find a separator, try to look for man* or cat*.
883 	 * If we find one of these and what's underneath is a directory,
884 	 * assume it's an architecture.
885 	 */
886 	if (NULL != (p = strchr(start, '/'))) {
887 		*p++ = '\0';
888 		if (0 == strncmp(start, "man", 3)) {
889 			mlink->dform = FORM_SRC;
890 			mlink->dsec = start + 3;
891 		} else if (0 == strncmp(start, "cat", 3)) {
892 			mlink->dform = FORM_CAT;
893 			mlink->dsec = start + 3;
894 		}
895 
896 		start = p;
897 		if (NULL != mlink->dsec && NULL != (p = strchr(start, '/'))) {
898 			*p++ = '\0';
899 			mlink->arch = start;
900 			start = p;
901 		}
902 	}
903 
904 	/*
905 	 * Now check the file suffix.
906 	 * Suffix of `.0' indicates a catpage, `.1-9' is a manpage.
907 	 */
908 	p = strrchr(start, '\0');
909 	while (p-- > start && '/' != *p && '.' != *p)
910 		/* Loop. */ ;
911 
912 	if ('.' == *p) {
913 		*p++ = '\0';
914 		mlink->fsec = p;
915 	}
916 
917 	/*
918 	 * Now try to parse the name.
919 	 * Use the filename portion of the path.
920 	 */
921 	mlink->name = start;
922 	if (NULL != (p = strrchr(start, '/'))) {
923 		mlink->name = p + 1;
924 		*p = '\0';
925 	}
926 	mlink_add(mlink, &st);
927 }
928 
929 static void
930 mlink_add(struct mlink *mlink, const struct stat *st)
931 {
932 	struct inodev	 inodev;
933 	struct mpage	*mpage;
934 	unsigned int	 slot;
935 
936 	assert(NULL != mlink->file);
937 
938 	mlink->dsec = mandoc_strdup(mlink->dsec ? mlink->dsec : "");
939 	mlink->arch = mandoc_strdup(mlink->arch ? mlink->arch : "");
940 	mlink->name = mandoc_strdup(mlink->name ? mlink->name : "");
941 	mlink->fsec = mandoc_strdup(mlink->fsec ? mlink->fsec : "");
942 
943 	if ('0' == *mlink->fsec) {
944 		free(mlink->fsec);
945 		mlink->fsec = mandoc_strdup(mlink->dsec);
946 		mlink->fform = FORM_CAT;
947 	} else if ('1' <= *mlink->fsec && '9' >= *mlink->fsec)
948 		mlink->fform = FORM_SRC;
949 	else
950 		mlink->fform = FORM_NONE;
951 
952 	slot = ohash_qlookup(&mlinks, mlink->file);
953 	assert(NULL == ohash_find(&mlinks, slot));
954 	ohash_insert(&mlinks, slot, mlink);
955 
956 	memset(&inodev, 0, sizeof(inodev));  /* Clear padding. */
957 	inodev.st_ino = st->st_ino;
958 	inodev.st_dev = st->st_dev;
959 	slot = ohash_lookup_memory(&mpages, (char *)&inodev,
960 	    sizeof(struct inodev), inodev.st_ino);
961 	mpage = ohash_find(&mpages, slot);
962 	if (NULL == mpage) {
963 		mpage = mandoc_calloc(1, sizeof(struct mpage));
964 		mpage->inodev.st_ino = inodev.st_ino;
965 		mpage->inodev.st_dev = inodev.st_dev;
966 		mpage->form = FORM_NONE;
967 		mpage->next = mpage_head;
968 		mpage_head = mpage;
969 		ohash_insert(&mpages, slot, mpage);
970 	} else
971 		mlink->next = mpage->mlinks;
972 	mpage->mlinks = mlink;
973 	mlink->mpage = mpage;
974 }
975 
976 static void
977 mlink_free(struct mlink *mlink)
978 {
979 
980 	free(mlink->dsec);
981 	free(mlink->arch);
982 	free(mlink->name);
983 	free(mlink->fsec);
984 	free(mlink);
985 }
986 
987 static void
988 mpages_free(void)
989 {
990 	struct mpage	*mpage;
991 	struct mlink	*mlink;
992 
993 	while ((mpage = mpage_head) != NULL) {
994 		while ((mlink = mpage->mlinks) != NULL) {
995 			mpage->mlinks = mlink->next;
996 			mlink_free(mlink);
997 		}
998 		mpage_head = mpage->next;
999 		free(mpage->sec);
1000 		free(mpage->arch);
1001 		free(mpage->title);
1002 		free(mpage->desc);
1003 		free(mpage);
1004 	}
1005 }
1006 
1007 /*
1008  * For each mlink to the mpage, check whether the path looks like
1009  * it is formatted, and if it does, check whether a source manual
1010  * exists by the same name, ignoring the suffix.
1011  * If both conditions hold, drop the mlink.
1012  */
1013 static void
1014 mlinks_undupe(struct mpage *mpage)
1015 {
1016 	char		  buf[PATH_MAX];
1017 	struct mlink	**prev;
1018 	struct mlink	 *mlink;
1019 	char		 *bufp;
1020 
1021 	mpage->form = FORM_CAT;
1022 	prev = &mpage->mlinks;
1023 	while (NULL != (mlink = *prev)) {
1024 		if (FORM_CAT != mlink->dform) {
1025 			mpage->form = FORM_NONE;
1026 			goto nextlink;
1027 		}
1028 		(void)strlcpy(buf, mlink->file, sizeof(buf));
1029 		bufp = strstr(buf, "cat");
1030 		assert(NULL != bufp);
1031 		memcpy(bufp, "man", 3);
1032 		if (NULL != (bufp = strrchr(buf, '.')))
1033 			*++bufp = '\0';
1034 		(void)strlcat(buf, mlink->dsec, sizeof(buf));
1035 		if (NULL == ohash_find(&mlinks,
1036 		    ohash_qlookup(&mlinks, buf)))
1037 			goto nextlink;
1038 		if (warnings)
1039 			say(mlink->file, "Man source exists: %s", buf);
1040 		if (use_all)
1041 			goto nextlink;
1042 		*prev = mlink->next;
1043 		mlink_free(mlink);
1044 		continue;
1045 nextlink:
1046 		prev = &(*prev)->next;
1047 	}
1048 }
1049 
1050 static void
1051 mlink_check(struct mpage *mpage, struct mlink *mlink)
1052 {
1053 	struct str	*str;
1054 	unsigned int	 slot;
1055 
1056 	/*
1057 	 * Check whether the manual section given in a file
1058 	 * agrees with the directory where the file is located.
1059 	 * Some manuals have suffixes like (3p) on their
1060 	 * section number either inside the file or in the
1061 	 * directory name, some are linked into more than one
1062 	 * section, like encrypt(1) = makekey(8).
1063 	 */
1064 
1065 	if (FORM_SRC == mpage->form &&
1066 	    strcasecmp(mpage->sec, mlink->dsec))
1067 		say(mlink->file, "Section \"%s\" manual in %s directory",
1068 		    mpage->sec, mlink->dsec);
1069 
1070 	/*
1071 	 * Manual page directories exist for each kernel
1072 	 * architecture as returned by machine(1).
1073 	 * However, many manuals only depend on the
1074 	 * application architecture as returned by arch(1).
1075 	 * For example, some (2/ARM) manuals are shared
1076 	 * across the "armish" and "zaurus" kernel
1077 	 * architectures.
1078 	 * A few manuals are even shared across completely
1079 	 * different architectures, for example fdformat(1)
1080 	 * on amd64, i386, and sparc64.
1081 	 */
1082 
1083 	if (strcasecmp(mpage->arch, mlink->arch))
1084 		say(mlink->file, "Architecture \"%s\" manual in "
1085 		    "\"%s\" directory", mpage->arch, mlink->arch);
1086 
1087 	/*
1088 	 * XXX
1089 	 * parse_cat() doesn't set NAME_TITLE yet.
1090 	 */
1091 
1092 	if (FORM_CAT == mpage->form)
1093 		return;
1094 
1095 	/*
1096 	 * Check whether this mlink
1097 	 * appears as a name in the NAME section.
1098 	 */
1099 
1100 	slot = ohash_qlookup(&names, mlink->name);
1101 	str = ohash_find(&names, slot);
1102 	assert(NULL != str);
1103 	if ( ! (NAME_TITLE & str->mask))
1104 		say(mlink->file, "Name missing in NAME section");
1105 }
1106 
1107 /*
1108  * Run through the files in the global vector "mpages"
1109  * and add them to the database specified in "basedir".
1110  *
1111  * This handles the parsing scheme itself, using the cues of directory
1112  * and filename to determine whether the file is parsable or not.
1113  */
1114 static void
1115 mpages_merge(struct dba *dba, struct mparse *mp)
1116 {
1117 	struct mpage		*mpage, *mpage_dest;
1118 	struct mlink		*mlink, *mlink_dest;
1119 	struct roff_man		*man;
1120 	char			*sodest;
1121 	char			*cp;
1122 	int			 fd;
1123 
1124 	for (mpage = mpage_head; mpage != NULL; mpage = mpage->next) {
1125 		mlinks_undupe(mpage);
1126 		if ((mlink = mpage->mlinks) == NULL)
1127 			continue;
1128 
1129 		name_mask = NAME_MASK;
1130 		mandoc_ohash_init(&names, 4, offsetof(struct str, key));
1131 		mandoc_ohash_init(&strings, 6, offsetof(struct str, key));
1132 		mparse_reset(mp);
1133 		man = NULL;
1134 		sodest = NULL;
1135 
1136 		if ((fd = mparse_open(mp, mlink->file)) == -1) {
1137 			say(mlink->file, "&open");
1138 			goto nextpage;
1139 		}
1140 
1141 		/*
1142 		 * Interpret the file as mdoc(7) or man(7) source
1143 		 * code, unless it is known to be formatted.
1144 		 */
1145 		if (mlink->dform != FORM_CAT || mlink->fform != FORM_CAT) {
1146 			mparse_readfd(mp, fd, mlink->file);
1147 			close(fd);
1148 			fd = -1;
1149 			mparse_result(mp, &man, &sodest);
1150 		}
1151 
1152 		if (sodest != NULL) {
1153 			mlink_dest = ohash_find(&mlinks,
1154 			    ohash_qlookup(&mlinks, sodest));
1155 			if (mlink_dest == NULL) {
1156 				mandoc_asprintf(&cp, "%s.gz", sodest);
1157 				mlink_dest = ohash_find(&mlinks,
1158 				    ohash_qlookup(&mlinks, cp));
1159 				free(cp);
1160 			}
1161 			if (mlink_dest != NULL) {
1162 
1163 				/* The .so target exists. */
1164 
1165 				mpage_dest = mlink_dest->mpage;
1166 				while (1) {
1167 					mlink->mpage = mpage_dest;
1168 
1169 					/*
1170 					 * If the target was already
1171 					 * processed, add the links
1172 					 * to the database now.
1173 					 * Otherwise, this will
1174 					 * happen when we come
1175 					 * to the target.
1176 					 */
1177 
1178 					if (mpage_dest->dba != NULL)
1179 						dbadd_mlink(mlink);
1180 
1181 					if (mlink->next == NULL)
1182 						break;
1183 					mlink = mlink->next;
1184 				}
1185 
1186 				/* Move all links to the target. */
1187 
1188 				mlink->next = mlink_dest->next;
1189 				mlink_dest->next = mpage->mlinks;
1190 				mpage->mlinks = NULL;
1191 			}
1192 			goto nextpage;
1193 		} else if (man != NULL && man->macroset == MACROSET_MDOC) {
1194 			mdoc_validate(man);
1195 			mpage->form = FORM_SRC;
1196 			mpage->sec = man->meta.msec;
1197 			mpage->sec = mandoc_strdup(
1198 			    mpage->sec == NULL ? "" : mpage->sec);
1199 			mpage->arch = man->meta.arch;
1200 			mpage->arch = mandoc_strdup(
1201 			    mpage->arch == NULL ? "" : mpage->arch);
1202 			mpage->title = mandoc_strdup(man->meta.title);
1203 		} else if (man != NULL && man->macroset == MACROSET_MAN) {
1204 			man_validate(man);
1205 			if (*man->meta.msec != '\0' ||
1206 			    *man->meta.title != '\0') {
1207 				mpage->form = FORM_SRC;
1208 				mpage->sec = mandoc_strdup(man->meta.msec);
1209 				mpage->arch = mandoc_strdup(mlink->arch);
1210 				mpage->title = mandoc_strdup(man->meta.title);
1211 			} else
1212 				man = NULL;
1213 		}
1214 
1215 		assert(mpage->desc == NULL);
1216 		if (man == NULL) {
1217 			mpage->form = FORM_CAT;
1218 			mpage->sec = mandoc_strdup(mlink->dsec);
1219 			mpage->arch = mandoc_strdup(mlink->arch);
1220 			mpage->title = mandoc_strdup(mlink->name);
1221 			parse_cat(mpage, fd);
1222 		} else if (man->macroset == MACROSET_MDOC)
1223 			parse_mdoc(mpage, &man->meta, man->first);
1224 		else
1225 			parse_man(mpage, &man->meta, man->first);
1226 		if (mpage->desc == NULL) {
1227 			mpage->desc = mandoc_strdup(mlink->name);
1228 			if (warnings)
1229 				say(mlink->file, "No one-line description, "
1230 				    "using filename \"%s\"", mlink->name);
1231 		}
1232 
1233 		for (mlink = mpage->mlinks;
1234 		     mlink != NULL;
1235 		     mlink = mlink->next) {
1236 			putkey(mpage, mlink->name, NAME_FILE);
1237 			if (warnings && !use_all)
1238 				mlink_check(mpage, mlink);
1239 		}
1240 
1241 		dbadd(dba, mpage);
1242 
1243 nextpage:
1244 		ohash_delete(&strings);
1245 		ohash_delete(&names);
1246 	}
1247 }
1248 
1249 static void
1250 parse_cat(struct mpage *mpage, int fd)
1251 {
1252 	FILE		*stream;
1253 	struct mlink	*mlink;
1254 	char		*line, *p, *title, *sec;
1255 	size_t		 linesz, plen, titlesz;
1256 	ssize_t		 len;
1257 	int		 offs;
1258 
1259 	mlink = mpage->mlinks;
1260 	stream = fd == -1 ? fopen(mlink->file, "r") : fdopen(fd, "r");
1261 	if (stream == NULL) {
1262 		if (fd != -1)
1263 			close(fd);
1264 		if (warnings)
1265 			say(mlink->file, "&fopen");
1266 		return;
1267 	}
1268 
1269 	line = NULL;
1270 	linesz = 0;
1271 
1272 	/* Parse the section number from the header line. */
1273 
1274 	while (getline(&line, &linesz, stream) != -1) {
1275 		if (*line == '\n')
1276 			continue;
1277 		if ((sec = strchr(line, '(')) == NULL)
1278 			break;
1279 		if ((p = strchr(++sec, ')')) == NULL)
1280 			break;
1281 		free(mpage->sec);
1282 		mpage->sec = mandoc_strndup(sec, p - sec);
1283 		if (warnings && *mlink->dsec != '\0' &&
1284 		    strcasecmp(mpage->sec, mlink->dsec))
1285 			say(mlink->file,
1286 			    "Section \"%s\" manual in %s directory",
1287 			    mpage->sec, mlink->dsec);
1288 		break;
1289 	}
1290 
1291 	/* Skip to first blank line. */
1292 
1293 	while (line == NULL || *line != '\n')
1294 		if (getline(&line, &linesz, stream) == -1)
1295 			break;
1296 
1297 	/*
1298 	 * Assume the first line that is not indented
1299 	 * is the first section header.  Skip to it.
1300 	 */
1301 
1302 	while (getline(&line, &linesz, stream) != -1)
1303 		if (*line != '\n' && *line != ' ')
1304 			break;
1305 
1306 	/*
1307 	 * Read up until the next section into a buffer.
1308 	 * Strip the leading and trailing newline from each read line,
1309 	 * appending a trailing space.
1310 	 * Ignore empty (whitespace-only) lines.
1311 	 */
1312 
1313 	titlesz = 0;
1314 	title = NULL;
1315 
1316 	while ((len = getline(&line, &linesz, stream)) != -1) {
1317 		if (*line != ' ')
1318 			break;
1319 		offs = 0;
1320 		while (isspace((unsigned char)line[offs]))
1321 			offs++;
1322 		if (line[offs] == '\0')
1323 			continue;
1324 		title = mandoc_realloc(title, titlesz + len - offs);
1325 		memcpy(title + titlesz, line + offs, len - offs);
1326 		titlesz += len - offs;
1327 		title[titlesz - 1] = ' ';
1328 	}
1329 	free(line);
1330 
1331 	/*
1332 	 * If no page content can be found, or the input line
1333 	 * is already the next section header, or there is no
1334 	 * trailing newline, reuse the page title as the page
1335 	 * description.
1336 	 */
1337 
1338 	if (NULL == title || '\0' == *title) {
1339 		if (warnings)
1340 			say(mlink->file, "Cannot find NAME section");
1341 		fclose(stream);
1342 		free(title);
1343 		return;
1344 	}
1345 
1346 	title[titlesz - 1] = '\0';
1347 
1348 	/*
1349 	 * Skip to the first dash.
1350 	 * Use the remaining line as the description (no more than 70
1351 	 * bytes).
1352 	 */
1353 
1354 	if (NULL != (p = strstr(title, "- "))) {
1355 		for (p += 2; ' ' == *p || '\b' == *p; p++)
1356 			/* Skip to next word. */ ;
1357 	} else {
1358 		if (warnings)
1359 			say(mlink->file, "No dash in title line, "
1360 			    "reusing \"%s\" as one-line description", title);
1361 		p = title;
1362 	}
1363 
1364 	plen = strlen(p);
1365 
1366 	/* Strip backspace-encoding from line. */
1367 
1368 	while (NULL != (line = memchr(p, '\b', plen))) {
1369 		len = line - p;
1370 		if (0 == len) {
1371 			memmove(line, line + 1, plen--);
1372 			continue;
1373 		}
1374 		memmove(line - 1, line + 1, plen - len);
1375 		plen -= 2;
1376 	}
1377 
1378 	/*
1379 	 * Cut off excessive one-line descriptions.
1380 	 * Bad pages are not worth better heuristics.
1381 	 */
1382 
1383 	mpage->desc = mandoc_strndup(p, 150);
1384 	fclose(stream);
1385 	free(title);
1386 }
1387 
1388 /*
1389  * Put a type/word pair into the word database for this particular file.
1390  */
1391 static void
1392 putkey(const struct mpage *mpage, char *value, uint64_t type)
1393 {
1394 	putkeys(mpage, value, strlen(value), type);
1395 }
1396 
1397 /*
1398  * Grok all nodes at or below a certain mdoc node into putkey().
1399  */
1400 static void
1401 putmdockey(const struct mpage *mpage,
1402 	const struct roff_node *n, uint64_t m, int taboo)
1403 {
1404 
1405 	for ( ; NULL != n; n = n->next) {
1406 		if (n->flags & taboo)
1407 			continue;
1408 		if (NULL != n->child)
1409 			putmdockey(mpage, n->child, m, taboo);
1410 		if (n->type == ROFFT_TEXT)
1411 			putkey(mpage, n->string, m);
1412 	}
1413 }
1414 
1415 static void
1416 parse_man(struct mpage *mpage, const struct roff_meta *meta,
1417 	const struct roff_node *n)
1418 {
1419 	const struct roff_node *head, *body;
1420 	char		*start, *title;
1421 	char		 byte;
1422 	size_t		 sz;
1423 
1424 	if (n == NULL)
1425 		return;
1426 
1427 	/*
1428 	 * We're only searching for one thing: the first text child in
1429 	 * the BODY of a NAME section.  Since we don't keep track of
1430 	 * sections in -man, run some hoops to find out whether we're in
1431 	 * the correct section or not.
1432 	 */
1433 
1434 	if (n->type == ROFFT_BODY && n->tok == MAN_SH) {
1435 		body = n;
1436 		if ((head = body->parent->head) != NULL &&
1437 		    (head = head->child) != NULL &&
1438 		    head->next == NULL &&
1439 		    head->type == ROFFT_TEXT &&
1440 		    strcmp(head->string, "NAME") == 0 &&
1441 		    body->child != NULL) {
1442 
1443 			/*
1444 			 * Suck the entire NAME section into memory.
1445 			 * Yes, we might run away.
1446 			 * But too many manuals have big, spread-out
1447 			 * NAME sections over many lines.
1448 			 */
1449 
1450 			title = NULL;
1451 			deroff(&title, body);
1452 			if (NULL == title)
1453 				return;
1454 
1455 			/*
1456 			 * Go through a special heuristic dance here.
1457 			 * Conventionally, one or more manual names are
1458 			 * comma-specified prior to a whitespace, then a
1459 			 * dash, then a description.  Try to puzzle out
1460 			 * the name parts here.
1461 			 */
1462 
1463 			start = title;
1464 			for ( ;; ) {
1465 				sz = strcspn(start, " ,");
1466 				if ('\0' == start[sz])
1467 					break;
1468 
1469 				byte = start[sz];
1470 				start[sz] = '\0';
1471 
1472 				/*
1473 				 * Assume a stray trailing comma in the
1474 				 * name list if a name begins with a dash.
1475 				 */
1476 
1477 				if ('-' == start[0] ||
1478 				    ('\\' == start[0] && '-' == start[1]))
1479 					break;
1480 
1481 				putkey(mpage, start, NAME_TITLE);
1482 				if ( ! (mpage->name_head_done ||
1483 				    strcasecmp(start, meta->title))) {
1484 					putkey(mpage, start, NAME_HEAD);
1485 					mpage->name_head_done = 1;
1486 				}
1487 
1488 				if (' ' == byte) {
1489 					start += sz + 1;
1490 					break;
1491 				}
1492 
1493 				assert(',' == byte);
1494 				start += sz + 1;
1495 				while (' ' == *start)
1496 					start++;
1497 			}
1498 
1499 			if (start == title) {
1500 				putkey(mpage, start, NAME_TITLE);
1501 				if ( ! (mpage->name_head_done ||
1502 				    strcasecmp(start, meta->title))) {
1503 					putkey(mpage, start, NAME_HEAD);
1504 					mpage->name_head_done = 1;
1505 				}
1506 				free(title);
1507 				return;
1508 			}
1509 
1510 			while (isspace((unsigned char)*start))
1511 				start++;
1512 
1513 			if (0 == strncmp(start, "-", 1))
1514 				start += 1;
1515 			else if (0 == strncmp(start, "\\-\\-", 4))
1516 				start += 4;
1517 			else if (0 == strncmp(start, "\\-", 2))
1518 				start += 2;
1519 			else if (0 == strncmp(start, "\\(en", 4))
1520 				start += 4;
1521 			else if (0 == strncmp(start, "\\(em", 4))
1522 				start += 4;
1523 
1524 			while (' ' == *start)
1525 				start++;
1526 
1527 			/*
1528 			 * Cut off excessive one-line descriptions.
1529 			 * Bad pages are not worth better heuristics.
1530 			 */
1531 
1532 			mpage->desc = mandoc_strndup(start, 150);
1533 			free(title);
1534 			return;
1535 		}
1536 	}
1537 
1538 	for (n = n->child; n; n = n->next) {
1539 		if (NULL != mpage->desc)
1540 			break;
1541 		parse_man(mpage, meta, n);
1542 	}
1543 }
1544 
1545 static void
1546 parse_mdoc(struct mpage *mpage, const struct roff_meta *meta,
1547 	const struct roff_node *n)
1548 {
1549 
1550 	for (n = n->child; n != NULL; n = n->next) {
1551 		if (n->tok == TOKEN_NONE ||
1552 		    n->tok < ROFF_MAX ||
1553 		    n->flags & mdocs[n->tok].taboo)
1554 			continue;
1555 		assert(n->tok >= MDOC_Dd && n->tok < MDOC_MAX);
1556 		switch (n->type) {
1557 		case ROFFT_ELEM:
1558 		case ROFFT_BLOCK:
1559 		case ROFFT_HEAD:
1560 		case ROFFT_BODY:
1561 		case ROFFT_TAIL:
1562 			if (mdocs[n->tok].fp != NULL &&
1563 			    (*mdocs[n->tok].fp)(mpage, meta, n) == 0)
1564 				break;
1565 			if (mdocs[n->tok].mask)
1566 				putmdockey(mpage, n->child,
1567 				    mdocs[n->tok].mask, mdocs[n->tok].taboo);
1568 			break;
1569 		default:
1570 			continue;
1571 		}
1572 		if (NULL != n->child)
1573 			parse_mdoc(mpage, meta, n);
1574 	}
1575 }
1576 
1577 static int
1578 parse_mdoc_Fa(struct mpage *mpage, const struct roff_meta *meta,
1579 	const struct roff_node *n)
1580 {
1581 	uint64_t mask;
1582 
1583 	mask = TYPE_Fa;
1584 	if (n->sec == SEC_SYNOPSIS)
1585 		mask |= TYPE_Vt;
1586 
1587 	putmdockey(mpage, n->child, mask, 0);
1588 	return 0;
1589 }
1590 
1591 static int
1592 parse_mdoc_Fd(struct mpage *mpage, const struct roff_meta *meta,
1593 	const struct roff_node *n)
1594 {
1595 	char		*start, *end;
1596 	size_t		 sz;
1597 
1598 	if (SEC_SYNOPSIS != n->sec ||
1599 	    NULL == (n = n->child) ||
1600 	    n->type != ROFFT_TEXT)
1601 		return 0;
1602 
1603 	/*
1604 	 * Only consider those `Fd' macro fields that begin with an
1605 	 * "inclusion" token (versus, e.g., #define).
1606 	 */
1607 
1608 	if (strcmp("#include", n->string))
1609 		return 0;
1610 
1611 	if ((n = n->next) == NULL || n->type != ROFFT_TEXT)
1612 		return 0;
1613 
1614 	/*
1615 	 * Strip away the enclosing angle brackets and make sure we're
1616 	 * not zero-length.
1617 	 */
1618 
1619 	start = n->string;
1620 	if ('<' == *start || '"' == *start)
1621 		start++;
1622 
1623 	if (0 == (sz = strlen(start)))
1624 		return 0;
1625 
1626 	end = &start[(int)sz - 1];
1627 	if ('>' == *end || '"' == *end)
1628 		end--;
1629 
1630 	if (end > start)
1631 		putkeys(mpage, start, end - start + 1, TYPE_In);
1632 	return 0;
1633 }
1634 
1635 static void
1636 parse_mdoc_fname(struct mpage *mpage, const struct roff_node *n)
1637 {
1638 	char	*cp;
1639 	size_t	 sz;
1640 
1641 	if (n->type != ROFFT_TEXT)
1642 		return;
1643 
1644 	/* Skip function pointer punctuation. */
1645 
1646 	cp = n->string;
1647 	while (*cp == '(' || *cp == '*')
1648 		cp++;
1649 	sz = strcspn(cp, "()");
1650 
1651 	putkeys(mpage, cp, sz, TYPE_Fn);
1652 	if (n->sec == SEC_SYNOPSIS)
1653 		putkeys(mpage, cp, sz, NAME_SYN);
1654 }
1655 
1656 static int
1657 parse_mdoc_Fn(struct mpage *mpage, const struct roff_meta *meta,
1658 	const struct roff_node *n)
1659 {
1660 	uint64_t mask;
1661 
1662 	if (n->child == NULL)
1663 		return 0;
1664 
1665 	parse_mdoc_fname(mpage, n->child);
1666 
1667 	n = n->child->next;
1668 	if (n != NULL && n->type == ROFFT_TEXT) {
1669 		mask = TYPE_Fa;
1670 		if (n->sec == SEC_SYNOPSIS)
1671 			mask |= TYPE_Vt;
1672 		putmdockey(mpage, n, mask, 0);
1673 	}
1674 
1675 	return 0;
1676 }
1677 
1678 static int
1679 parse_mdoc_Fo(struct mpage *mpage, const struct roff_meta *meta,
1680 	const struct roff_node *n)
1681 {
1682 
1683 	if (n->type != ROFFT_HEAD)
1684 		return 1;
1685 
1686 	if (n->child != NULL)
1687 		parse_mdoc_fname(mpage, n->child);
1688 
1689 	return 0;
1690 }
1691 
1692 static int
1693 parse_mdoc_Va(struct mpage *mpage, const struct roff_meta *meta,
1694 	const struct roff_node *n)
1695 {
1696 	char *cp;
1697 
1698 	if (n->type != ROFFT_ELEM && n->type != ROFFT_BODY)
1699 		return 0;
1700 
1701 	if (n->child != NULL &&
1702 	    n->child->next == NULL &&
1703 	    n->child->type == ROFFT_TEXT)
1704 		return 1;
1705 
1706 	cp = NULL;
1707 	deroff(&cp, n);
1708 	if (cp != NULL) {
1709 		putkey(mpage, cp, TYPE_Vt | (n->tok == MDOC_Va ||
1710 		    n->type == ROFFT_BODY ? TYPE_Va : 0));
1711 		free(cp);
1712 	}
1713 
1714 	return 0;
1715 }
1716 
1717 static int
1718 parse_mdoc_Xr(struct mpage *mpage, const struct roff_meta *meta,
1719 	const struct roff_node *n)
1720 {
1721 	char	*cp;
1722 
1723 	if (NULL == (n = n->child))
1724 		return 0;
1725 
1726 	if (NULL == n->next) {
1727 		putkey(mpage, n->string, TYPE_Xr);
1728 		return 0;
1729 	}
1730 
1731 	mandoc_asprintf(&cp, "%s(%s)", n->string, n->next->string);
1732 	putkey(mpage, cp, TYPE_Xr);
1733 	free(cp);
1734 	return 0;
1735 }
1736 
1737 static int
1738 parse_mdoc_Nd(struct mpage *mpage, const struct roff_meta *meta,
1739 	const struct roff_node *n)
1740 {
1741 
1742 	if (n->type == ROFFT_BODY)
1743 		deroff(&mpage->desc, n);
1744 	return 0;
1745 }
1746 
1747 static int
1748 parse_mdoc_Nm(struct mpage *mpage, const struct roff_meta *meta,
1749 	const struct roff_node *n)
1750 {
1751 
1752 	if (SEC_NAME == n->sec)
1753 		putmdockey(mpage, n->child, NAME_TITLE, 0);
1754 	else if (n->sec == SEC_SYNOPSIS && n->type == ROFFT_HEAD) {
1755 		if (n->child == NULL)
1756 			putkey(mpage, meta->name, NAME_SYN);
1757 		else
1758 			putmdockey(mpage, n->child, NAME_SYN, 0);
1759 	}
1760 	if ( ! (mpage->name_head_done ||
1761 	    n->child == NULL || n->child->string == NULL ||
1762 	    strcasecmp(n->child->string, meta->title))) {
1763 		putkey(mpage, n->child->string, NAME_HEAD);
1764 		mpage->name_head_done = 1;
1765 	}
1766 	return 0;
1767 }
1768 
1769 static int
1770 parse_mdoc_Sh(struct mpage *mpage, const struct roff_meta *meta,
1771 	const struct roff_node *n)
1772 {
1773 
1774 	return n->sec == SEC_CUSTOM && n->type == ROFFT_HEAD;
1775 }
1776 
1777 static int
1778 parse_mdoc_head(struct mpage *mpage, const struct roff_meta *meta,
1779 	const struct roff_node *n)
1780 {
1781 
1782 	return n->type == ROFFT_HEAD;
1783 }
1784 
1785 /*
1786  * Add a string to the hash table for the current manual.
1787  * Each string has a bitmask telling which macros it belongs to.
1788  * When we finish the manual, we'll dump the table.
1789  */
1790 static void
1791 putkeys(const struct mpage *mpage, char *cp, size_t sz, uint64_t v)
1792 {
1793 	struct ohash	*htab;
1794 	struct str	*s;
1795 	const char	*end;
1796 	unsigned int	 slot;
1797 	int		 i, mustfree;
1798 
1799 	if (0 == sz)
1800 		return;
1801 
1802 	mustfree = render_string(&cp, &sz);
1803 
1804 	if (TYPE_Nm & v) {
1805 		htab = &names;
1806 		v &= name_mask;
1807 		if (v & NAME_FIRST)
1808 			name_mask &= ~NAME_FIRST;
1809 		if (debug > 1)
1810 			say(mpage->mlinks->file,
1811 			    "Adding name %*s, bits=0x%llx", (int)sz, cp,
1812 			    (unsigned long long)v);
1813 	} else {
1814 		htab = &strings;
1815 		if (debug > 1)
1816 		    for (i = 0; i < KEY_MAX; i++)
1817 			if ((uint64_t)1 << i & v)
1818 			    say(mpage->mlinks->file,
1819 				"Adding key %s=%*s",
1820 				mansearch_keynames[i], (int)sz, cp);
1821 	}
1822 
1823 	end = cp + sz;
1824 	slot = ohash_qlookupi(htab, cp, &end);
1825 	s = ohash_find(htab, slot);
1826 
1827 	if (NULL != s && mpage == s->mpage) {
1828 		s->mask |= v;
1829 		return;
1830 	} else if (NULL == s) {
1831 		s = mandoc_calloc(1, sizeof(struct str) + sz + 1);
1832 		memcpy(s->key, cp, sz);
1833 		ohash_insert(htab, slot, s);
1834 	}
1835 	s->mpage = mpage;
1836 	s->mask = v;
1837 
1838 	if (mustfree)
1839 		free(cp);
1840 }
1841 
1842 /*
1843  * Take a Unicode codepoint and produce its UTF-8 encoding.
1844  * This isn't the best way to do this, but it works.
1845  * The magic numbers are from the UTF-8 packaging.
1846  * They're not as scary as they seem: read the UTF-8 spec for details.
1847  */
1848 static size_t
1849 utf8(unsigned int cp, char out[7])
1850 {
1851 	size_t		 rc;
1852 
1853 	rc = 0;
1854 	if (cp <= 0x0000007F) {
1855 		rc = 1;
1856 		out[0] = (char)cp;
1857 	} else if (cp <= 0x000007FF) {
1858 		rc = 2;
1859 		out[0] = (cp >> 6  & 31) | 192;
1860 		out[1] = (cp       & 63) | 128;
1861 	} else if (cp <= 0x0000FFFF) {
1862 		rc = 3;
1863 		out[0] = (cp >> 12 & 15) | 224;
1864 		out[1] = (cp >> 6  & 63) | 128;
1865 		out[2] = (cp       & 63) | 128;
1866 	} else if (cp <= 0x001FFFFF) {
1867 		rc = 4;
1868 		out[0] = (cp >> 18 &  7) | 240;
1869 		out[1] = (cp >> 12 & 63) | 128;
1870 		out[2] = (cp >> 6  & 63) | 128;
1871 		out[3] = (cp       & 63) | 128;
1872 	} else if (cp <= 0x03FFFFFF) {
1873 		rc = 5;
1874 		out[0] = (cp >> 24 &  3) | 248;
1875 		out[1] = (cp >> 18 & 63) | 128;
1876 		out[2] = (cp >> 12 & 63) | 128;
1877 		out[3] = (cp >> 6  & 63) | 128;
1878 		out[4] = (cp       & 63) | 128;
1879 	} else if (cp <= 0x7FFFFFFF) {
1880 		rc = 6;
1881 		out[0] = (cp >> 30 &  1) | 252;
1882 		out[1] = (cp >> 24 & 63) | 128;
1883 		out[2] = (cp >> 18 & 63) | 128;
1884 		out[3] = (cp >> 12 & 63) | 128;
1885 		out[4] = (cp >> 6  & 63) | 128;
1886 		out[5] = (cp       & 63) | 128;
1887 	} else
1888 		return 0;
1889 
1890 	out[rc] = '\0';
1891 	return rc;
1892 }
1893 
1894 /*
1895  * If the string contains escape sequences,
1896  * replace it with an allocated rendering and return 1,
1897  * such that the caller can free it after use.
1898  * Otherwise, do nothing and return 0.
1899  */
1900 static int
1901 render_string(char **public, size_t *psz)
1902 {
1903 	const char	*src, *scp, *addcp, *seq;
1904 	char		*dst;
1905 	size_t		 ssz, dsz, addsz;
1906 	char		 utfbuf[7], res[6];
1907 	int		 seqlen, unicode;
1908 
1909 	res[0] = '\\';
1910 	res[1] = '\t';
1911 	res[2] = ASCII_NBRSP;
1912 	res[3] = ASCII_HYPH;
1913 	res[4] = ASCII_BREAK;
1914 	res[5] = '\0';
1915 
1916 	src = scp = *public;
1917 	ssz = *psz;
1918 	dst = NULL;
1919 	dsz = 0;
1920 
1921 	while (scp < src + *psz) {
1922 
1923 		/* Leave normal characters unchanged. */
1924 
1925 		if (strchr(res, *scp) == NULL) {
1926 			if (dst != NULL)
1927 				dst[dsz++] = *scp;
1928 			scp++;
1929 			continue;
1930 		}
1931 
1932 		/*
1933 		 * Found something that requires replacing,
1934 		 * make sure we have a destination buffer.
1935 		 */
1936 
1937 		if (dst == NULL) {
1938 			dst = mandoc_malloc(ssz + 1);
1939 			dsz = scp - src;
1940 			memcpy(dst, src, dsz);
1941 		}
1942 
1943 		/* Handle single-char special characters. */
1944 
1945 		switch (*scp) {
1946 		case '\\':
1947 			break;
1948 		case '\t':
1949 		case ASCII_NBRSP:
1950 			dst[dsz++] = ' ';
1951 			scp++;
1952 			continue;
1953 		case ASCII_HYPH:
1954 			dst[dsz++] = '-';
1955 			/* FALLTHROUGH */
1956 		case ASCII_BREAK:
1957 			scp++;
1958 			continue;
1959 		default:
1960 			abort();
1961 		}
1962 
1963 		/*
1964 		 * Found an escape sequence.
1965 		 * Read past the slash, then parse it.
1966 		 * Ignore everything except characters.
1967 		 */
1968 
1969 		scp++;
1970 		if (mandoc_escape(&scp, &seq, &seqlen) != ESCAPE_SPECIAL)
1971 			continue;
1972 
1973 		/*
1974 		 * Render the special character
1975 		 * as either UTF-8 or ASCII.
1976 		 */
1977 
1978 		if (write_utf8) {
1979 			unicode = mchars_spec2cp(seq, seqlen);
1980 			if (unicode <= 0)
1981 				continue;
1982 			addsz = utf8(unicode, utfbuf);
1983 			if (addsz == 0)
1984 				continue;
1985 			addcp = utfbuf;
1986 		} else {
1987 			addcp = mchars_spec2str(seq, seqlen, &addsz);
1988 			if (addcp == NULL)
1989 				continue;
1990 			if (*addcp == ASCII_NBRSP) {
1991 				addcp = " ";
1992 				addsz = 1;
1993 			}
1994 		}
1995 
1996 		/* Copy the rendered glyph into the stream. */
1997 
1998 		ssz += addsz;
1999 		dst = mandoc_realloc(dst, ssz + 1);
2000 		memcpy(dst + dsz, addcp, addsz);
2001 		dsz += addsz;
2002 	}
2003 	if (dst != NULL) {
2004 		*public = dst;
2005 		*psz = dsz;
2006 	}
2007 
2008 	/* Trim trailing whitespace and NUL-terminate. */
2009 
2010 	while (*psz > 0 && (*public)[*psz - 1] == ' ')
2011 		--*psz;
2012 	if (dst != NULL) {
2013 		(*public)[*psz] = '\0';
2014 		return 1;
2015 	} else
2016 		return 0;
2017 }
2018 
2019 static void
2020 dbadd_mlink(const struct mlink *mlink)
2021 {
2022 	dba_page_alias(mlink->mpage->dba, mlink->name, NAME_FILE);
2023 	dba_page_add(mlink->mpage->dba, DBP_SECT, mlink->dsec);
2024 	dba_page_add(mlink->mpage->dba, DBP_SECT, mlink->fsec);
2025 	dba_page_add(mlink->mpage->dba, DBP_ARCH, mlink->arch);
2026 	dba_page_add(mlink->mpage->dba, DBP_FILE, mlink->file);
2027 }
2028 
2029 /*
2030  * Flush the current page's terms (and their bits) into the database.
2031  * Also, handle escape sequences at the last possible moment.
2032  */
2033 static void
2034 dbadd(struct dba *dba, struct mpage *mpage)
2035 {
2036 	struct mlink	*mlink;
2037 	struct str	*key;
2038 	char		*cp;
2039 	uint64_t	 mask;
2040 	size_t		 i;
2041 	unsigned int	 slot;
2042 	int		 mustfree;
2043 
2044 	mlink = mpage->mlinks;
2045 
2046 	if (nodb) {
2047 		for (key = ohash_first(&names, &slot); NULL != key;
2048 		     key = ohash_next(&names, &slot))
2049 			free(key);
2050 		for (key = ohash_first(&strings, &slot); NULL != key;
2051 		     key = ohash_next(&strings, &slot))
2052 			free(key);
2053 		if (0 == debug)
2054 			return;
2055 		while (NULL != mlink) {
2056 			fputs(mlink->name, stdout);
2057 			if (NULL == mlink->next ||
2058 			    strcmp(mlink->dsec, mlink->next->dsec) ||
2059 			    strcmp(mlink->fsec, mlink->next->fsec) ||
2060 			    strcmp(mlink->arch, mlink->next->arch)) {
2061 				putchar('(');
2062 				if ('\0' == *mlink->dsec)
2063 					fputs(mlink->fsec, stdout);
2064 				else
2065 					fputs(mlink->dsec, stdout);
2066 				if ('\0' != *mlink->arch)
2067 					printf("/%s", mlink->arch);
2068 				putchar(')');
2069 			}
2070 			mlink = mlink->next;
2071 			if (NULL != mlink)
2072 				fputs(", ", stdout);
2073 		}
2074 		printf(" - %s\n", mpage->desc);
2075 		return;
2076 	}
2077 
2078 	if (debug)
2079 		say(mlink->file, "Adding to database");
2080 
2081 	cp = mpage->desc;
2082 	i = strlen(cp);
2083 	mustfree = render_string(&cp, &i);
2084 	mpage->dba = dba_page_new(dba->pages,
2085 	    *mpage->arch == '\0' ? mlink->arch : mpage->arch,
2086 	    cp, mlink->file, mpage->form);
2087 	if (mustfree)
2088 		free(cp);
2089 	dba_page_add(mpage->dba, DBP_SECT, mpage->sec);
2090 
2091 	while (mlink != NULL) {
2092 		dbadd_mlink(mlink);
2093 		mlink = mlink->next;
2094 	}
2095 
2096 	for (key = ohash_first(&names, &slot); NULL != key;
2097 	     key = ohash_next(&names, &slot)) {
2098 		assert(key->mpage == mpage);
2099 		dba_page_alias(mpage->dba, key->key, key->mask);
2100 		free(key);
2101 	}
2102 	for (key = ohash_first(&strings, &slot); NULL != key;
2103 	     key = ohash_next(&strings, &slot)) {
2104 		assert(key->mpage == mpage);
2105 		i = 0;
2106 		for (mask = TYPE_Xr; mask <= TYPE_Lb; mask *= 2) {
2107 			if (key->mask & mask)
2108 				dba_macro_add(dba->macros, i,
2109 				    key->key, mpage->dba);
2110 			i++;
2111 		}
2112 		free(key);
2113 	}
2114 }
2115 
2116 static void
2117 dbprune(struct dba *dba)
2118 {
2119 	struct dba_array	*page, *files;
2120 	char			*file;
2121 
2122 	dba_array_FOREACH(dba->pages, page) {
2123 		files = dba_array_get(page, DBP_FILE);
2124 		dba_array_FOREACH(files, file) {
2125 			if (*file < ' ')
2126 				file++;
2127 			if (ohash_find(&mlinks, ohash_qlookup(&mlinks,
2128 			    file)) != NULL) {
2129 				if (debug)
2130 					say(file, "Deleting from database");
2131 				dba_array_del(dba->pages);
2132 				break;
2133 			}
2134 		}
2135 	}
2136 }
2137 
2138 /*
2139  * Write the database from memory to disk.
2140  */
2141 static void
2142 dbwrite(struct dba *dba)
2143 {
2144 	struct stat	 sb1, sb2;
2145 	char		 tfn[33], *cp1, *cp2;
2146 	off_t		 i;
2147 	int		 fd1, fd2;
2148 
2149 	/*
2150 	 * Do not write empty databases, and delete existing ones
2151 	 * when makewhatis -u causes them to become empty.
2152 	 */
2153 
2154 	dba_array_start(dba->pages);
2155 	if (dba_array_next(dba->pages) == NULL) {
2156 		if (unlink(MANDOC_DB) == -1 && errno != ENOENT)
2157 			say(MANDOC_DB, "&unlink");
2158 		return;
2159 	}
2160 
2161 	/*
2162 	 * Build the database in a temporary file,
2163 	 * then atomically move it into place.
2164 	 */
2165 
2166 	if (dba_write(MANDOC_DB "~", dba) != -1) {
2167 		if (rename(MANDOC_DB "~", MANDOC_DB) == -1) {
2168 			exitcode = (int)MANDOCLEVEL_SYSERR;
2169 			say(MANDOC_DB, "&rename");
2170 			unlink(MANDOC_DB "~");
2171 		}
2172 		return;
2173 	}
2174 
2175 	/*
2176 	 * We lack write permission and cannot replace the database
2177 	 * file, but let's at least check whether the data changed.
2178 	 */
2179 
2180 	(void)strlcpy(tfn, "/tmp/mandocdb.XXXXXXXX", sizeof(tfn));
2181 	if (mkdtemp(tfn) == NULL) {
2182 		exitcode = (int)MANDOCLEVEL_SYSERR;
2183 		say("", "&%s", tfn);
2184 		return;
2185 	}
2186 	cp1 = cp2 = MAP_FAILED;
2187 	fd1 = fd2 = -1;
2188 	(void)strlcat(tfn, "/" MANDOC_DB, sizeof(tfn));
2189 	if (dba_write(tfn, dba) == -1) {
2190 		say(tfn, "&dba_write");
2191 		goto err;
2192 	}
2193 	if ((fd1 = open(MANDOC_DB, O_RDONLY, 0)) == -1) {
2194 		say(MANDOC_DB, "&open");
2195 		goto err;
2196 	}
2197 	if ((fd2 = open(tfn, O_RDONLY, 0)) == -1) {
2198 		say(tfn, "&open");
2199 		goto err;
2200 	}
2201 	if (fstat(fd1, &sb1) == -1) {
2202 		say(MANDOC_DB, "&fstat");
2203 		goto err;
2204 	}
2205 	if (fstat(fd2, &sb2) == -1) {
2206 		say(tfn, "&fstat");
2207 		goto err;
2208 	}
2209 	if (sb1.st_size != sb2.st_size)
2210 		goto err;
2211 	if ((cp1 = mmap(NULL, sb1.st_size, PROT_READ, MAP_PRIVATE,
2212 	    fd1, 0)) == MAP_FAILED) {
2213 		say(MANDOC_DB, "&mmap");
2214 		goto err;
2215 	}
2216 	if ((cp2 = mmap(NULL, sb2.st_size, PROT_READ, MAP_PRIVATE,
2217 	    fd2, 0)) == MAP_FAILED) {
2218 		say(tfn, "&mmap");
2219 		goto err;
2220 	}
2221 	for (i = 0; i < sb1.st_size; i++)
2222 		if (cp1[i] != cp2[i])
2223 			goto err;
2224 	goto out;
2225 
2226 err:
2227 	exitcode = (int)MANDOCLEVEL_SYSERR;
2228 	say(MANDOC_DB, "Data changed, but cannot replace database");
2229 
2230 out:
2231 	if (cp1 != MAP_FAILED)
2232 		munmap(cp1, sb1.st_size);
2233 	if (cp2 != MAP_FAILED)
2234 		munmap(cp2, sb2.st_size);
2235 	if (fd1 != -1)
2236 		close(fd1);
2237 	if (fd2 != -1)
2238 		close(fd2);
2239 	unlink(tfn);
2240 	*strrchr(tfn, '/') = '\0';
2241 	rmdir(tfn);
2242 }
2243 
2244 static int
2245 set_basedir(const char *targetdir, int report_baddir)
2246 {
2247 	static char	 startdir[PATH_MAX];
2248 	static int	 getcwd_status;  /* 1 = ok, 2 = failure */
2249 	static int	 chdir_status;  /* 1 = changed directory */
2250 	char		*cp;
2251 
2252 	/*
2253 	 * Remember the original working directory, if possible.
2254 	 * This will be needed if the second or a later directory
2255 	 * on the command line is given as a relative path.
2256 	 * Do not error out if the current directory is not
2257 	 * searchable: Maybe it won't be needed after all.
2258 	 */
2259 	if (0 == getcwd_status) {
2260 		if (NULL == getcwd(startdir, sizeof(startdir))) {
2261 			getcwd_status = 2;
2262 			(void)strlcpy(startdir, strerror(errno),
2263 			    sizeof(startdir));
2264 		} else
2265 			getcwd_status = 1;
2266 	}
2267 
2268 	/*
2269 	 * We are leaving the old base directory.
2270 	 * Do not use it any longer, not even for messages.
2271 	 */
2272 	*basedir = '\0';
2273 
2274 	/*
2275 	 * If and only if the directory was changed earlier and
2276 	 * the next directory to process is given as a relative path,
2277 	 * first go back, or bail out if that is impossible.
2278 	 */
2279 	if (chdir_status && '/' != *targetdir) {
2280 		if (2 == getcwd_status) {
2281 			exitcode = (int)MANDOCLEVEL_SYSERR;
2282 			say("", "getcwd: %s", startdir);
2283 			return 0;
2284 		}
2285 		if (-1 == chdir(startdir)) {
2286 			exitcode = (int)MANDOCLEVEL_SYSERR;
2287 			say("", "&chdir %s", startdir);
2288 			return 0;
2289 		}
2290 	}
2291 
2292 	/*
2293 	 * Always resolve basedir to the canonicalized absolute
2294 	 * pathname and append a trailing slash, such that
2295 	 * we can reliably check whether files are inside.
2296 	 */
2297 	if (NULL == realpath(targetdir, basedir)) {
2298 		if (report_baddir || errno != ENOENT) {
2299 			exitcode = (int)MANDOCLEVEL_BADARG;
2300 			say("", "&%s: realpath", targetdir);
2301 		}
2302 		return 0;
2303 	} else if (-1 == chdir(basedir)) {
2304 		if (report_baddir || errno != ENOENT) {
2305 			exitcode = (int)MANDOCLEVEL_BADARG;
2306 			say("", "&chdir");
2307 		}
2308 		return 0;
2309 	}
2310 	chdir_status = 1;
2311 	cp = strchr(basedir, '\0');
2312 	if ('/' != cp[-1]) {
2313 		if (cp - basedir >= PATH_MAX - 1) {
2314 			exitcode = (int)MANDOCLEVEL_SYSERR;
2315 			say("", "Filename too long");
2316 			return 0;
2317 		}
2318 		*cp++ = '/';
2319 		*cp = '\0';
2320 	}
2321 	return 1;
2322 }
2323 
2324 static void
2325 say(const char *file, const char *format, ...)
2326 {
2327 	va_list		 ap;
2328 	int		 use_errno;
2329 
2330 	if ('\0' != *basedir)
2331 		fprintf(stderr, "%s", basedir);
2332 	if ('\0' != *basedir && '\0' != *file)
2333 		fputc('/', stderr);
2334 	if ('\0' != *file)
2335 		fprintf(stderr, "%s", file);
2336 
2337 	use_errno = 1;
2338 	if (NULL != format) {
2339 		switch (*format) {
2340 		case '&':
2341 			format++;
2342 			break;
2343 		case '\0':
2344 			format = NULL;
2345 			break;
2346 		default:
2347 			use_errno = 0;
2348 			break;
2349 		}
2350 	}
2351 	if (NULL != format) {
2352 		if ('\0' != *basedir || '\0' != *file)
2353 			fputs(": ", stderr);
2354 		va_start(ap, format);
2355 		vfprintf(stderr, format, ap);
2356 		va_end(ap);
2357 	}
2358 	if (use_errno) {
2359 		if ('\0' != *basedir || '\0' != *file || NULL != format)
2360 			fputs(": ", stderr);
2361 		perror(NULL);
2362 	} else
2363 		fputc('\n', stderr);
2364 }
2365