mansearch.c revision 276219 
1/*	$Id: mansearch.c,v 1.52 2014/12/06 01:23:24 schwarze Exp $ */
2/*
3 * Copyright (c) 2012 Kristaps Dzonsons <kristaps@bsd.lv>
4 * Copyright (c) 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18#include "config.h"
19
20#include <sys/mman.h>
21#include <sys/types.h>
22
23#include <assert.h>
24#include <errno.h>
25#include <fcntl.h>
26#include <getopt.h>
27#include <limits.h>
28#include <regex.h>
29#include <stdio.h>
30#include <stdint.h>
31#include <stddef.h>
32#include <stdlib.h>
33#include <string.h>
34#include <unistd.h>
35
36#if HAVE_OHASH
37#include <ohash.h>
38#else
39#include "compat_ohash.h"
40#endif
41#include <sqlite3.h>
42#ifndef SQLITE_DETERMINISTIC
43#define SQLITE_DETERMINISTIC 0
44#endif
45
46#include "mandoc.h"
47#include "mandoc_aux.h"
48#include "manpath.h"
49#include "mansearch.h"
50
51extern int mansearch_keymax;
52extern const char *const mansearch_keynames[];
53
54#define	SQL_BIND_TEXT(_db, _s, _i, _v) \
55	do { if (SQLITE_OK != sqlite3_bind_text \
56		((_s), (_i)++, (_v), -1, SQLITE_STATIC)) \
57		fprintf(stderr, "%s\n", sqlite3_errmsg((_db))); \
58	} while (0)
59#define	SQL_BIND_INT64(_db, _s, _i, _v) \
60	do { if (SQLITE_OK != sqlite3_bind_int64 \
61		((_s), (_i)++, (_v))) \
62		fprintf(stderr, "%s\n", sqlite3_errmsg((_db))); \
63	} while (0)
64#define	SQL_BIND_BLOB(_db, _s, _i, _v) \
65	do { if (SQLITE_OK != sqlite3_bind_blob \
66		((_s), (_i)++, (&_v), sizeof(_v), SQLITE_STATIC)) \
67		fprintf(stderr, "%s\n", sqlite3_errmsg((_db))); \
68	} while (0)
69
70struct	expr {
71	regex_t		 regexp;  /* compiled regexp, if applicable */
72	const char	*substr;  /* to search for, if applicable */
73	struct expr	*next;    /* next in sequence */
74	uint64_t	 bits;    /* type-mask */
75	int		 equal;   /* equality, not subsring match */
76	int		 open;    /* opening parentheses before */
77	int		 and;	  /* logical AND before */
78	int		 close;   /* closing parentheses after */
79};
80
81struct	match {
82	uint64_t	 pageid; /* identifier in database */
83	uint64_t	 bits; /* name type mask */
84	char		*desc; /* manual page description */
85	int		 form; /* bit field: formatted, zipped? */
86};
87
88static	void		 buildnames(struct manpage *, sqlite3 *,
89				sqlite3_stmt *, uint64_t,
90				const char *, int form);
91static	char		*buildoutput(sqlite3 *, sqlite3_stmt *,
92				 uint64_t, uint64_t);
93static	void		*hash_alloc(size_t, void *);
94static	void		 hash_free(void *, void *);
95static	void		*hash_calloc(size_t, size_t, void *);
96static	struct expr	*exprcomp(const struct mansearch *,
97				int, char *[]);
98static	void		 exprfree(struct expr *);
99static	struct expr	*exprspec(struct expr *, uint64_t,
100				 const char *, const char *);
101static	struct expr	*exprterm(const struct mansearch *, char *, int);
102static	int		 manpage_compare(const void *, const void *);
103static	void		 sql_append(char **sql, size_t *sz,
104				const char *newstr, int count);
105static	void		 sql_match(sqlite3_context *context,
106				int argc, sqlite3_value **argv);
107static	void		 sql_regexp(sqlite3_context *context,
108				int argc, sqlite3_value **argv);
109static	char		*sql_statement(const struct expr *);
110
111
112int
113mansearch_setup(int start)
114{
115	static void	*pagecache;
116	int		 c;
117
118#define	PC_PAGESIZE	1280
119#define	PC_NUMPAGES	256
120
121	if (start) {
122		if (NULL != pagecache) {
123			fprintf(stderr, "pagecache already enabled\n");
124			return((int)MANDOCLEVEL_BADARG);
125		}
126
127		pagecache = mmap(NULL, PC_PAGESIZE * PC_NUMPAGES,
128		    PROT_READ | PROT_WRITE,
129		    MAP_SHARED | MAP_ANON, -1, 0);
130
131		if (MAP_FAILED == pagecache) {
132			perror("mmap");
133			pagecache = NULL;
134			return((int)MANDOCLEVEL_SYSERR);
135		}
136
137		c = sqlite3_config(SQLITE_CONFIG_PAGECACHE,
138		    pagecache, PC_PAGESIZE, PC_NUMPAGES);
139
140		if (SQLITE_OK == c)
141			return((int)MANDOCLEVEL_OK);
142
143		fprintf(stderr, "pagecache: %s\n", sqlite3_errstr(c));
144
145	} else if (NULL == pagecache) {
146		fprintf(stderr, "pagecache missing\n");
147		return((int)MANDOCLEVEL_BADARG);
148	}
149
150	if (-1 == munmap(pagecache, PC_PAGESIZE * PC_NUMPAGES)) {
151		perror("munmap");
152		pagecache = NULL;
153		return((int)MANDOCLEVEL_SYSERR);
154	}
155
156	pagecache = NULL;
157	return((int)MANDOCLEVEL_OK);
158}
159
160int
161mansearch(const struct mansearch *search,
162		const struct manpaths *paths,
163		int argc, char *argv[],
164		struct manpage **res, size_t *sz)
165{
166	int		 fd, rc, c, indexbit;
167	int64_t		 pageid;
168	uint64_t	 outbit, iterbit;
169	char		 buf[PATH_MAX];
170	char		*sql;
171	struct manpage	*mpage;
172	struct expr	*e, *ep;
173	sqlite3		*db;
174	sqlite3_stmt	*s, *s2;
175	struct match	*mp;
176	struct ohash_info info;
177	struct ohash	 htab;
178	unsigned int	 idx;
179	size_t		 i, j, cur, maxres;
180
181	info.calloc = hash_calloc;
182	info.alloc = hash_alloc;
183	info.free = hash_free;
184	info.key_offset = offsetof(struct match, pageid);
185
186	*sz = cur = maxres = 0;
187	sql = NULL;
188	*res = NULL;
189	fd = -1;
190	e = NULL;
191	rc = 0;
192
193	if (0 == argc)
194		goto out;
195	if (NULL == (e = exprcomp(search, argc, argv)))
196		goto out;
197
198	outbit = 0;
199	if (NULL != search->outkey) {
200		for (indexbit = 0, iterbit = 1;
201		     indexbit < mansearch_keymax;
202		     indexbit++, iterbit <<= 1) {
203			if (0 == strcasecmp(search->outkey,
204			    mansearch_keynames[indexbit])) {
205				outbit = iterbit;
206				break;
207			}
208		}
209	}
210
211	/*
212	 * Save a descriptor to the current working directory.
213	 * Since pathnames in the "paths" variable might be relative,
214	 * and we'll be chdir()ing into them, we need to keep a handle
215	 * on our current directory from which to start the chdir().
216	 */
217
218	if (NULL == getcwd(buf, PATH_MAX)) {
219		perror("getcwd");
220		goto out;
221	} else if (-1 == (fd = open(buf, O_RDONLY, 0))) {
222		perror(buf);
223		goto out;
224	}
225
226	sql = sql_statement(e);
227
228	/*
229	 * Loop over the directories (containing databases) for us to
230	 * search.
231	 * Don't let missing/bad databases/directories phase us.
232	 * In each, try to open the resident database and, if it opens,
233	 * scan it for our match expression.
234	 */
235
236	for (i = 0; i < paths->sz; i++) {
237		if (-1 == fchdir(fd)) {
238			perror(buf);
239			free(*res);
240			break;
241		} else if (-1 == chdir(paths->paths[i])) {
242			perror(paths->paths[i]);
243			continue;
244		}
245
246		c = sqlite3_open_v2(MANDOC_DB, &db,
247		    SQLITE_OPEN_READONLY, NULL);
248
249		if (SQLITE_OK != c) {
250			fprintf(stderr, "%s/%s: %s\n",
251			    paths->paths[i], MANDOC_DB, strerror(errno));
252			sqlite3_close(db);
253			continue;
254		}
255
256		/*
257		 * Define the SQL functions for substring
258		 * and regular expression matching.
259		 */
260
261		c = sqlite3_create_function(db, "match", 2,
262		    SQLITE_UTF8 | SQLITE_DETERMINISTIC,
263		    NULL, sql_match, NULL, NULL);
264		assert(SQLITE_OK == c);
265		c = sqlite3_create_function(db, "regexp", 2,
266		    SQLITE_UTF8 | SQLITE_DETERMINISTIC,
267		    NULL, sql_regexp, NULL, NULL);
268		assert(SQLITE_OK == c);
269
270		j = 1;
271		c = sqlite3_prepare_v2(db, sql, -1, &s, NULL);
272		if (SQLITE_OK != c)
273			fprintf(stderr, "%s\n", sqlite3_errmsg(db));
274
275		for (ep = e; NULL != ep; ep = ep->next) {
276			if (NULL == ep->substr) {
277				SQL_BIND_BLOB(db, s, j, ep->regexp);
278			} else
279				SQL_BIND_TEXT(db, s, j, ep->substr);
280			if (0 == ((TYPE_Nd | TYPE_Nm) & ep->bits))
281				SQL_BIND_INT64(db, s, j, ep->bits);
282		}
283
284		memset(&htab, 0, sizeof(struct ohash));
285		ohash_init(&htab, 4, &info);
286
287		/*
288		 * Hash each entry on its [unique] document identifier.
289		 * This is a uint64_t.
290		 * Instead of using a hash function, simply convert the
291		 * uint64_t to a uint32_t, the hash value's type.
292		 * This gives good performance and preserves the
293		 * distribution of buckets in the table.
294		 */
295		while (SQLITE_ROW == (c = sqlite3_step(s))) {
296			pageid = sqlite3_column_int64(s, 2);
297			idx = ohash_lookup_memory(&htab,
298			    (char *)&pageid, sizeof(uint64_t),
299			    (uint32_t)pageid);
300
301			if (NULL != ohash_find(&htab, idx))
302				continue;
303
304			mp = mandoc_calloc(1, sizeof(struct match));
305			mp->pageid = pageid;
306			mp->form = sqlite3_column_int(s, 1);
307			mp->bits = sqlite3_column_int64(s, 3);
308			if (TYPE_Nd == outbit)
309				mp->desc = mandoc_strdup((const char *)
310				    sqlite3_column_text(s, 0));
311			ohash_insert(&htab, idx, mp);
312		}
313
314		if (SQLITE_DONE != c)
315			fprintf(stderr, "%s\n", sqlite3_errmsg(db));
316
317		sqlite3_finalize(s);
318
319		c = sqlite3_prepare_v2(db,
320		    "SELECT sec, arch, name, pageid FROM mlinks "
321		    "WHERE pageid=? ORDER BY sec, arch, name",
322		    -1, &s, NULL);
323		if (SQLITE_OK != c)
324			fprintf(stderr, "%s\n", sqlite3_errmsg(db));
325
326		c = sqlite3_prepare_v2(db,
327		    "SELECT bits, key, pageid FROM keys "
328		    "WHERE pageid=? AND bits & ?",
329		    -1, &s2, NULL);
330		if (SQLITE_OK != c)
331			fprintf(stderr, "%s\n", sqlite3_errmsg(db));
332
333		for (mp = ohash_first(&htab, &idx);
334				NULL != mp;
335				mp = ohash_next(&htab, &idx)) {
336			if (cur + 1 > maxres) {
337				maxres += 1024;
338				*res = mandoc_reallocarray(*res,
339				    maxres, sizeof(struct manpage));
340			}
341			mpage = *res + cur;
342			mpage->ipath = i;
343			mpage->bits = mp->bits;
344			mpage->sec = 10;
345			mpage->form = mp->form;
346			buildnames(mpage, db, s, mp->pageid,
347			    paths->paths[i], mp->form);
348			mpage->output = TYPE_Nd & outbit ?
349			    mp->desc : outbit ?
350			    buildoutput(db, s2, mp->pageid, outbit) : NULL;
351
352			free(mp);
353			cur++;
354		}
355
356		sqlite3_finalize(s);
357		sqlite3_finalize(s2);
358		sqlite3_close(db);
359		ohash_delete(&htab);
360
361		/*
362		 * In man(1) mode, prefer matches in earlier trees
363		 * over matches in later trees.
364		 */
365
366		if (cur && search->firstmatch)
367			break;
368	}
369	qsort(*res, cur, sizeof(struct manpage), manpage_compare);
370	rc = 1;
371out:
372	if (-1 != fd) {
373		if (-1 == fchdir(fd))
374			perror(buf);
375		close(fd);
376	}
377	exprfree(e);
378	free(sql);
379	*sz = cur;
380	return(rc);
381}
382
383void
384mansearch_free(struct manpage *res, size_t sz)
385{
386	size_t	 i;
387
388	for (i = 0; i < sz; i++) {
389		free(res[i].file);
390		free(res[i].names);
391		free(res[i].output);
392	}
393	free(res);
394}
395
396static int
397manpage_compare(const void *vp1, const void *vp2)
398{
399	const struct manpage	*mp1, *mp2;
400	int			 diff;
401
402	mp1 = vp1;
403	mp2 = vp2;
404	return(	(diff = mp2->bits - mp1->bits) ? diff :
405		(diff = mp1->sec - mp2->sec) ? diff :
406		strcasecmp(mp1->names, mp2->names));
407}
408
409static void
410buildnames(struct manpage *mpage, sqlite3 *db, sqlite3_stmt *s,
411		uint64_t pageid, const char *path, int form)
412{
413	char		*newnames, *prevsec, *prevarch;
414	const char	*oldnames, *sep1, *name, *sec, *sep2, *arch, *fsec;
415	size_t		 i;
416	int		 c;
417
418	mpage->file = NULL;
419	mpage->names = NULL;
420	prevsec = prevarch = NULL;
421	i = 1;
422	SQL_BIND_INT64(db, s, i, pageid);
423	while (SQLITE_ROW == (c = sqlite3_step(s))) {
424
425		/* Decide whether we already have some names. */
426
427		if (NULL == mpage->names) {
428			oldnames = "";
429			sep1 = "";
430		} else {
431			oldnames = mpage->names;
432			sep1 = ", ";
433		}
434
435		/* Fetch the next name. */
436
437		sec = (const char *)sqlite3_column_text(s, 0);
438		arch = (const char *)sqlite3_column_text(s, 1);
439		name = (const char *)sqlite3_column_text(s, 2);
440
441		/* Remember the first section found. */
442
443		if (9 < mpage->sec && '1' <= *sec && '9' >= *sec)
444			mpage->sec = (*sec - '1') + 1;
445
446		/* If the section changed, append the old one. */
447
448		if (NULL != prevsec &&
449		    (strcmp(sec, prevsec) ||
450		     strcmp(arch, prevarch))) {
451			sep2 = '\0' == *prevarch ? "" : "/";
452			mandoc_asprintf(&newnames, "%s(%s%s%s)",
453			    oldnames, prevsec, sep2, prevarch);
454			free(mpage->names);
455			oldnames = mpage->names = newnames;
456			free(prevsec);
457			free(prevarch);
458			prevsec = prevarch = NULL;
459		}
460
461		/* Save the new section, to append it later. */
462
463		if (NULL == prevsec) {
464			prevsec = mandoc_strdup(sec);
465			prevarch = mandoc_strdup(arch);
466		}
467
468		/* Append the new name. */
469
470		mandoc_asprintf(&newnames, "%s%s%s",
471		    oldnames, sep1, name);
472		free(mpage->names);
473		mpage->names = newnames;
474
475		/* Also save the first file name encountered. */
476
477		if (mpage->file != NULL)
478			continue;
479
480		if (form & FORM_SRC) {
481			sep1 = "man";
482			fsec = sec;
483		} else {
484			sep1 = "cat";
485			fsec = "0";
486		}
487		sep2 = *arch == '\0' ? "" : "/";
488		mandoc_asprintf(&mpage->file, "%s/%s%s%s%s/%s.%s",
489		    path, sep1, sec, sep2, arch, name, fsec);
490	}
491	if (c != SQLITE_DONE)
492		fprintf(stderr, "%s\n", sqlite3_errmsg(db));
493	sqlite3_reset(s);
494
495	/* Append one final section to the names. */
496
497	if (prevsec != NULL) {
498		sep2 = *prevarch == '\0' ? "" : "/";
499		mandoc_asprintf(&newnames, "%s(%s%s%s)",
500		    mpage->names, prevsec, sep2, prevarch);
501		free(mpage->names);
502		mpage->names = newnames;
503		free(prevsec);
504		free(prevarch);
505	}
506}
507
508static char *
509buildoutput(sqlite3 *db, sqlite3_stmt *s, uint64_t pageid, uint64_t outbit)
510{
511	char		*output, *newoutput;
512	const char	*oldoutput, *sep1, *data;
513	size_t		 i;
514	int		 c;
515
516	output = NULL;
517	i = 1;
518	SQL_BIND_INT64(db, s, i, pageid);
519	SQL_BIND_INT64(db, s, i, outbit);
520	while (SQLITE_ROW == (c = sqlite3_step(s))) {
521		if (NULL == output) {
522			oldoutput = "";
523			sep1 = "";
524		} else {
525			oldoutput = output;
526			sep1 = " # ";
527		}
528		data = (const char *)sqlite3_column_text(s, 1);
529		mandoc_asprintf(&newoutput, "%s%s%s",
530		    oldoutput, sep1, data);
531		free(output);
532		output = newoutput;
533	}
534	if (SQLITE_DONE != c)
535		fprintf(stderr, "%s\n", sqlite3_errmsg(db));
536	sqlite3_reset(s);
537	return(output);
538}
539
540/*
541 * Implement substring match as an application-defined SQL function.
542 * Using the SQL LIKE or GLOB operators instead would be a bad idea
543 * because that would require escaping metacharacters in the string
544 * being searched for.
545 */
546static void
547sql_match(sqlite3_context *context, int argc, sqlite3_value **argv)
548{
549
550	assert(2 == argc);
551	sqlite3_result_int(context, NULL != strcasestr(
552	    (const char *)sqlite3_value_text(argv[1]),
553	    (const char *)sqlite3_value_text(argv[0])));
554}
555
556/*
557 * Implement regular expression match
558 * as an application-defined SQL function.
559 */
560static void
561sql_regexp(sqlite3_context *context, int argc, sqlite3_value **argv)
562{
563
564	assert(2 == argc);
565	sqlite3_result_int(context, !regexec(
566	    (regex_t *)sqlite3_value_blob(argv[0]),
567	    (const char *)sqlite3_value_text(argv[1]),
568	    0, NULL, 0));
569}
570
571static void
572sql_append(char **sql, size_t *sz, const char *newstr, int count)
573{
574	size_t		 newsz;
575
576	newsz = 1 < count ? (size_t)count : strlen(newstr);
577	*sql = mandoc_realloc(*sql, *sz + newsz + 1);
578	if (1 < count)
579		memset(*sql + *sz, *newstr, (size_t)count);
580	else
581		memcpy(*sql + *sz, newstr, newsz);
582	*sz += newsz;
583	(*sql)[*sz] = '\0';
584}
585
586/*
587 * Prepare the search SQL statement.
588 */
589static char *
590sql_statement(const struct expr *e)
591{
592	char		*sql;
593	size_t		 sz;
594	int		 needop;
595
596	sql = mandoc_strdup(e->equal ?
597	    "SELECT desc, form, pageid, bits "
598		"FROM mpages NATURAL JOIN names WHERE " :
599	    "SELECT desc, form, pageid, 0 FROM mpages WHERE ");
600	sz = strlen(sql);
601
602	for (needop = 0; NULL != e; e = e->next) {
603		if (e->and)
604			sql_append(&sql, &sz, " AND ", 1);
605		else if (needop)
606			sql_append(&sql, &sz, " OR ", 1);
607		if (e->open)
608			sql_append(&sql, &sz, "(", e->open);
609		sql_append(&sql, &sz,
610		    TYPE_Nd & e->bits
611		    ? (NULL == e->substr
612			? "desc REGEXP ?"
613			: "desc MATCH ?")
614		    : TYPE_Nm == e->bits
615		    ? (NULL == e->substr
616			? "pageid IN (SELECT pageid FROM names "
617			  "WHERE name REGEXP ?)"
618			: e->equal
619			? "name = ? "
620			: "pageid IN (SELECT pageid FROM names "
621			  "WHERE name MATCH ?)")
622		    : (NULL == e->substr
623			? "pageid IN (SELECT pageid FROM keys "
624			  "WHERE key REGEXP ? AND bits & ?)"
625			: "pageid IN (SELECT pageid FROM keys "
626			  "WHERE key MATCH ? AND bits & ?)"), 1);
627		if (e->close)
628			sql_append(&sql, &sz, ")", e->close);
629		needop = 1;
630	}
631
632	return(sql);
633}
634
635/*
636 * Compile a set of string tokens into an expression.
637 * Tokens in "argv" are assumed to be individual expression atoms (e.g.,
638 * "(", "foo=bar", etc.).
639 */
640static struct expr *
641exprcomp(const struct mansearch *search, int argc, char *argv[])
642{
643	uint64_t	 mask;
644	int		 i, toopen, logic, igncase, toclose;
645	struct expr	*first, *prev, *cur, *next;
646
647	first = cur = NULL;
648	logic = igncase = toclose = 0;
649	toopen = NULL != search->sec || NULL != search->arch;
650
651	for (i = 0; i < argc; i++) {
652		if (0 == strcmp("(", argv[i])) {
653			if (igncase)
654				goto fail;
655			toopen++;
656			toclose++;
657			continue;
658		} else if (0 == strcmp(")", argv[i])) {
659			if (toopen || logic || igncase || NULL == cur)
660				goto fail;
661			cur->close++;
662			if (0 > --toclose)
663				goto fail;
664			continue;
665		} else if (0 == strcmp("-a", argv[i])) {
666			if (toopen || logic || igncase || NULL == cur)
667				goto fail;
668			logic = 1;
669			continue;
670		} else if (0 == strcmp("-o", argv[i])) {
671			if (toopen || logic || igncase || NULL == cur)
672				goto fail;
673			logic = 2;
674			continue;
675		} else if (0 == strcmp("-i", argv[i])) {
676			if (igncase)
677				goto fail;
678			igncase = 1;
679			continue;
680		}
681		next = exprterm(search, argv[i], !igncase);
682		if (NULL == next)
683			goto fail;
684		if (NULL == first)
685			first = next;
686		else
687			cur->next = next;
688		prev = cur = next;
689
690		/*
691		 * Searching for descriptions must be split out
692		 * because they are stored in the mpages table,
693		 * not in the keys table.
694		 */
695
696		for (mask = TYPE_Nm; mask <= TYPE_Nd; mask <<= 1) {
697			if (mask & cur->bits && ~mask & cur->bits) {
698				next = mandoc_calloc(1,
699				    sizeof(struct expr));
700				memcpy(next, cur, sizeof(struct expr));
701				prev->open = 1;
702				cur->bits = mask;
703				cur->next = next;
704				cur = next;
705				cur->bits &= ~mask;
706			}
707		}
708		prev->and = (1 == logic);
709		prev->open += toopen;
710		if (cur != prev)
711			cur->close = 1;
712
713		toopen = logic = igncase = 0;
714	}
715	if (toopen || logic || igncase || toclose)
716		goto fail;
717
718	if (NULL != search->sec || NULL != search->arch)
719		cur->close++;
720	if (NULL != search->arch)
721		cur = exprspec(cur, TYPE_arch, search->arch, "^(%s|any)$");
722	if (NULL != search->sec)
723		exprspec(cur, TYPE_sec, search->sec, "^%s$");
724
725	return(first);
726
727fail:
728	if (NULL != first)
729		exprfree(first);
730	return(NULL);
731}
732
733static struct expr *
734exprspec(struct expr *cur, uint64_t key, const char *value,
735		const char *format)
736{
737	char	 errbuf[BUFSIZ];
738	char	*cp;
739	int	 irc;
740
741	mandoc_asprintf(&cp, format, value);
742	cur->next = mandoc_calloc(1, sizeof(struct expr));
743	cur = cur->next;
744	cur->and = 1;
745	cur->bits = key;
746	if (0 != (irc = regcomp(&cur->regexp, cp,
747	    REG_EXTENDED | REG_NOSUB | REG_ICASE))) {
748		regerror(irc, &cur->regexp, errbuf, sizeof(errbuf));
749		fprintf(stderr, "regcomp: %s\n", errbuf);
750		cur->substr = value;
751	}
752	free(cp);
753	return(cur);
754}
755
756static struct expr *
757exprterm(const struct mansearch *search, char *buf, int cs)
758{
759	char		 errbuf[BUFSIZ];
760	struct expr	*e;
761	char		*key, *val;
762	uint64_t	 iterbit;
763	int		 i, irc;
764
765	if ('\0' == *buf)
766		return(NULL);
767
768	e = mandoc_calloc(1, sizeof(struct expr));
769
770	if (search->argmode == ARG_NAME) {
771		e->bits = TYPE_Nm;
772		e->substr = buf;
773		e->equal = 1;
774		return(e);
775	}
776
777	/*
778	 * Separate macro keys from search string.
779	 * If needed, request regular expression handling
780	 * by setting e->substr to NULL.
781	 */
782
783	if (search->argmode == ARG_WORD) {
784		e->bits = TYPE_Nm;
785		e->substr = NULL;
786		mandoc_asprintf(&val, "[[:<:]]%s[[:>:]]", buf);
787		cs = 0;
788	} else if ((val = strpbrk(buf, "=~")) == NULL) {
789		e->bits = TYPE_Nm | TYPE_Nd;
790		e->substr = buf;
791	} else {
792		if (val == buf)
793			e->bits = TYPE_Nm | TYPE_Nd;
794		if ('=' == *val)
795			e->substr = val + 1;
796		*val++ = '\0';
797		if (NULL != strstr(buf, "arch"))
798			cs = 0;
799	}
800
801	/* Compile regular expressions. */
802
803	if (NULL == e->substr) {
804		irc = regcomp(&e->regexp, val,
805		    REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE));
806		if (search->argmode == ARG_WORD)
807			free(val);
808		if (irc) {
809			regerror(irc, &e->regexp, errbuf, sizeof(errbuf));
810			fprintf(stderr, "regcomp: %s\n", errbuf);
811			free(e);
812			return(NULL);
813		}
814	}
815
816	if (e->bits)
817		return(e);
818
819	/*
820	 * Parse out all possible fields.
821	 * If the field doesn't resolve, bail.
822	 */
823
824	while (NULL != (key = strsep(&buf, ","))) {
825		if ('\0' == *key)
826			continue;
827		for (i = 0, iterbit = 1;
828		     i < mansearch_keymax;
829		     i++, iterbit <<= 1) {
830			if (0 == strcasecmp(key,
831			    mansearch_keynames[i])) {
832				e->bits |= iterbit;
833				break;
834			}
835		}
836		if (i == mansearch_keymax) {
837			if (strcasecmp(key, "any")) {
838				free(e);
839				return(NULL);
840			}
841			e->bits |= ~0ULL;
842		}
843	}
844
845	return(e);
846}
847
848static void
849exprfree(struct expr *p)
850{
851	struct expr	*pp;
852
853	while (NULL != p) {
854		pp = p->next;
855		free(p);
856		p = pp;
857	}
858}
859
860static void *
861hash_calloc(size_t nmemb, size_t sz, void *arg)
862{
863
864	return(mandoc_calloc(nmemb, sz));
865}
866
867static void *
868hash_alloc(size_t sz, void *arg)
869{
870
871	return(mandoc_malloc(sz));
872}
873
874static void
875hash_free(void *p, void *arg)
876{
877
878	free(p);
879}
880