Annotation of mandoc/apropos_db.c, Revision 1.19
1.19 ! kristaps 1: /* $Id: apropos_db.c,v 1.18 2011/12/01 23:55:58 kristaps Exp $ */
1.1 schwarze 2: /*
3: * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
1.3 schwarze 4: * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
1.1 schwarze 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: */
1.19 ! kristaps 18: #ifdef HAVE_CONFIG_H
! 19: #include "config.h"
! 20: #endif
! 21:
1.1 schwarze 22: #include <assert.h>
23: #include <fcntl.h>
24: #include <regex.h>
25: #include <stdarg.h>
1.6 kristaps 26: #include <stdint.h>
1.1 schwarze 27: #include <stdlib.h>
28: #include <string.h>
1.8 kristaps 29: #include <unistd.h>
1.1 schwarze 30:
1.19 ! kristaps 31: #if defined(__linux__)
! 32: # include <endian.h>
1.1 schwarze 33: # include <db_185.h>
1.19 ! kristaps 34: #elif defined(__APPLE__)
! 35: # include <libkern/OSByteOrder.h>
! 36: # include <db.h>
1.1 schwarze 37: #else
38: # include <db.h>
39: #endif
40:
1.2 schwarze 41: #include "mandocdb.h"
1.1 schwarze 42: #include "apropos_db.h"
43: #include "mandoc.h"
44:
1.5 kristaps 45: struct rec {
46: struct res res; /* resulting record info */
47: /*
48: * Maintain a binary tree for checking the uniqueness of `rec'
49: * when adding elements to the results array.
50: * Since the results array is dynamic, use offset in the array
51: * instead of a pointer to the structure.
52: */
53: int lhs;
54: int rhs;
55: int matched; /* expression is true */
56: int *matches; /* partial truth evaluations */
57: };
58:
1.1 schwarze 59: struct expr {
1.5 kristaps 60: int regex; /* is regex? */
61: int index; /* index in match array */
1.6 kristaps 62: uint64_t mask; /* type-mask */
1.5 kristaps 63: int and; /* is rhs of logical AND? */
64: char *v; /* search value */
65: regex_t re; /* compiled re, if regex */
66: struct expr *next; /* next in sequence */
67: struct expr *subexpr;
1.1 schwarze 68: };
69:
70: struct type {
1.6 kristaps 71: uint64_t mask;
1.1 schwarze 72: const char *name;
73: };
74:
1.8 kristaps 75: struct rectree {
76: struct rec *node; /* record array for dir tree */
77: int len; /* length of record array */
78: };
79:
1.1 schwarze 80: static const struct type types[] = {
1.7 kristaps 81: { TYPE_An, "An" },
82: { TYPE_Ar, "Ar" },
83: { TYPE_At, "At" },
84: { TYPE_Bsx, "Bsx" },
85: { TYPE_Bx, "Bx" },
86: { TYPE_Cd, "Cd" },
87: { TYPE_Cm, "Cm" },
88: { TYPE_Dv, "Dv" },
89: { TYPE_Dx, "Dx" },
90: { TYPE_Em, "Em" },
91: { TYPE_Er, "Er" },
92: { TYPE_Ev, "Ev" },
93: { TYPE_Fa, "Fa" },
94: { TYPE_Fl, "Fl" },
95: { TYPE_Fn, "Fn" },
96: { TYPE_Fn, "Fo" },
97: { TYPE_Ft, "Ft" },
98: { TYPE_Fx, "Fx" },
99: { TYPE_Ic, "Ic" },
100: { TYPE_In, "In" },
101: { TYPE_Lb, "Lb" },
102: { TYPE_Li, "Li" },
103: { TYPE_Lk, "Lk" },
104: { TYPE_Ms, "Ms" },
105: { TYPE_Mt, "Mt" },
106: { TYPE_Nd, "Nd" },
107: { TYPE_Nm, "Nm" },
108: { TYPE_Nx, "Nx" },
109: { TYPE_Ox, "Ox" },
110: { TYPE_Pa, "Pa" },
111: { TYPE_Rs, "Rs" },
112: { TYPE_Sh, "Sh" },
113: { TYPE_Ss, "Ss" },
114: { TYPE_St, "St" },
115: { TYPE_Sy, "Sy" },
116: { TYPE_Tn, "Tn" },
117: { TYPE_Va, "Va" },
118: { TYPE_Va, "Vt" },
119: { TYPE_Xr, "Xr" },
1.2 schwarze 120: { INT_MAX, "any" },
1.1 schwarze 121: { 0, NULL }
122: };
123:
124: static DB *btree_open(void);
1.17 kristaps 125: static int btree_read(const DBT *, const DBT *,
126: const struct mchars *,
127: struct db_val *, char **);
1.5 kristaps 128: static int expreval(const struct expr *, int *);
1.12 schwarze 129: static void exprexec(const struct expr *,
1.6 kristaps 130: const char *, uint64_t, struct rec *);
1.12 schwarze 131: static int exprmark(const struct expr *,
1.6 kristaps 132: const char *, uint64_t, int *);
1.5 kristaps 133: static struct expr *exprexpr(int, char *[], int *, int *, size_t *);
134: static struct expr *exprterm(char *, int);
1.1 schwarze 135: static DB *index_open(void);
1.11 kristaps 136: static int index_read(const DBT *, const DBT *, int,
1.1 schwarze 137: const struct mchars *, struct rec *);
138: static void norm_string(const char *,
139: const struct mchars *, char **);
140: static size_t norm_utf8(unsigned int, char[7]);
1.5 kristaps 141: static void recfree(struct rec *);
1.8 kristaps 142: static int single_search(struct rectree *, const struct opts *,
143: const struct expr *, size_t terms,
1.11 kristaps 144: struct mchars *, int);
1.1 schwarze 145:
146: /*
147: * Open the keyword mandoc-db database.
148: */
149: static DB *
150: btree_open(void)
151: {
152: BTREEINFO info;
153: DB *db;
154:
155: memset(&info, 0, sizeof(BTREEINFO));
156: info.flags = R_DUP;
157:
1.2 schwarze 158: db = dbopen(MANDOC_DB, O_RDONLY, 0, DB_BTREE, &info);
1.12 schwarze 159: if (NULL != db)
1.1 schwarze 160: return(db);
161:
162: return(NULL);
163: }
164:
165: /*
166: * Read a keyword from the database and normalise it.
167: * Return 0 if the database is insane, else 1.
168: */
169: static int
1.17 kristaps 170: btree_read(const DBT *k, const DBT *v,
171: const struct mchars *mc,
172: struct db_val *dbv, char **buf)
1.1 schwarze 173: {
1.17 kristaps 174: const struct db_val *vp;
1.1 schwarze 175:
1.17 kristaps 176: /* Are our sizes sane? */
177: if (k->size < 2 || sizeof(struct db_val) != v->size)
178: return(0);
1.6 kristaps 179:
1.17 kristaps 180: /* Is our string nil-terminated? */
181: if ('\0' != ((const char *)k->data)[(int)k->size - 1])
1.1 schwarze 182: return(0);
183:
1.17 kristaps 184: vp = v->data;
185: norm_string((const char *)k->data, mc, buf);
1.18 kristaps 186: dbv->rec = betoh32(vp->rec);
187: dbv->mask = betoh64(vp->mask);
1.1 schwarze 188: return(1);
189: }
190:
191: /*
192: * Take a Unicode codepoint and produce its UTF-8 encoding.
193: * This isn't the best way to do this, but it works.
1.12 schwarze 194: * The magic numbers are from the UTF-8 packaging.
1.1 schwarze 195: * They're not as scary as they seem: read the UTF-8 spec for details.
196: */
197: static size_t
198: norm_utf8(unsigned int cp, char out[7])
199: {
200: size_t rc;
201:
202: rc = 0;
203:
204: if (cp <= 0x0000007F) {
205: rc = 1;
206: out[0] = (char)cp;
207: } else if (cp <= 0x000007FF) {
208: rc = 2;
209: out[0] = (cp >> 6 & 31) | 192;
210: out[1] = (cp & 63) | 128;
211: } else if (cp <= 0x0000FFFF) {
212: rc = 3;
213: out[0] = (cp >> 12 & 15) | 224;
214: out[1] = (cp >> 6 & 63) | 128;
215: out[2] = (cp & 63) | 128;
216: } else if (cp <= 0x001FFFFF) {
217: rc = 4;
218: out[0] = (cp >> 18 & 7) | 240;
219: out[1] = (cp >> 12 & 63) | 128;
220: out[2] = (cp >> 6 & 63) | 128;
221: out[3] = (cp & 63) | 128;
222: } else if (cp <= 0x03FFFFFF) {
223: rc = 5;
224: out[0] = (cp >> 24 & 3) | 248;
225: out[1] = (cp >> 18 & 63) | 128;
226: out[2] = (cp >> 12 & 63) | 128;
227: out[3] = (cp >> 6 & 63) | 128;
228: out[4] = (cp & 63) | 128;
229: } else if (cp <= 0x7FFFFFFF) {
230: rc = 6;
231: out[0] = (cp >> 30 & 1) | 252;
232: out[1] = (cp >> 24 & 63) | 128;
233: out[2] = (cp >> 18 & 63) | 128;
234: out[3] = (cp >> 12 & 63) | 128;
235: out[4] = (cp >> 6 & 63) | 128;
236: out[5] = (cp & 63) | 128;
237: } else
238: return(0);
239:
240: out[rc] = '\0';
241: return(rc);
242: }
243:
244: /*
245: * Normalise strings from the index and database.
246: * These strings are escaped as defined by mandoc_char(7) along with
247: * other goop in mandoc.h (e.g., soft hyphens).
248: * This function normalises these into a nice UTF-8 string.
249: * Returns 0 if the database is fucked.
250: */
251: static void
252: norm_string(const char *val, const struct mchars *mc, char **buf)
253: {
254: size_t sz, bsz;
255: char utfbuf[7];
256: const char *seq, *cpp;
257: int len, u, pos;
258: enum mandoc_esc esc;
1.12 schwarze 259: static const char res[] = { '\\', '\t',
1.1 schwarze 260: ASCII_NBRSP, ASCII_HYPH, '\0' };
261:
262: /* Pre-allocate by the length of the input */
263:
264: bsz = strlen(val) + 1;
265: *buf = mandoc_realloc(*buf, bsz);
266: pos = 0;
267:
268: while ('\0' != *val) {
269: /*
270: * Halt on the first escape sequence.
271: * This also halts on the end of string, in which case
272: * we just copy, fallthrough, and exit the loop.
273: */
274: if ((sz = strcspn(val, res)) > 0) {
275: memcpy(&(*buf)[pos], val, sz);
276: pos += (int)sz;
277: val += (int)sz;
278: }
279:
280: if (ASCII_HYPH == *val) {
281: (*buf)[pos++] = '-';
282: val++;
283: continue;
284: } else if ('\t' == *val || ASCII_NBRSP == *val) {
285: (*buf)[pos++] = ' ';
286: val++;
287: continue;
288: } else if ('\\' != *val)
289: break;
290:
291: /* Read past the slash. */
292:
293: val++;
294: u = 0;
295:
296: /*
297: * Parse the escape sequence and see if it's a
298: * predefined character or special character.
299: */
300:
301: esc = mandoc_escape(&val, &seq, &len);
302: if (ESCAPE_ERROR == esc)
303: break;
304:
1.12 schwarze 305: /*
1.1 schwarze 306: * XXX - this just does UTF-8, but we need to know
307: * beforehand whether we should do text substitution.
308: */
309:
310: switch (esc) {
311: case (ESCAPE_SPECIAL):
312: if (0 != (u = mchars_spec2cp(mc, seq, len)))
313: break;
314: /* FALLTHROUGH */
315: default:
316: continue;
317: }
318:
319: /*
320: * If we have a Unicode codepoint, try to convert that
321: * to a UTF-8 byte string.
322: */
323:
324: cpp = utfbuf;
325: if (0 == (sz = norm_utf8(u, utfbuf)))
326: continue;
327:
328: /* Copy the rendered glyph into the stream. */
329:
330: sz = strlen(cpp);
331: bsz += sz;
332:
333: *buf = mandoc_realloc(*buf, bsz);
334:
335: memcpy(&(*buf)[pos], cpp, sz);
336: pos += (int)sz;
337: }
338:
339: (*buf)[pos] = '\0';
340: }
341:
342: /*
343: * Open the filename-index mandoc-db database.
344: * Returns NULL if opening failed.
345: */
346: static DB *
347: index_open(void)
348: {
349: DB *db;
350:
1.2 schwarze 351: db = dbopen(MANDOC_IDX, O_RDONLY, 0, DB_RECNO, NULL);
1.1 schwarze 352: if (NULL != db)
353: return(db);
354:
355: return(NULL);
356: }
357:
358: /*
359: * Safely unpack from an index file record into the structure.
360: * Returns 1 if an entry was unpacked, 0 if the database is insane.
361: */
362: static int
1.11 kristaps 363: index_read(const DBT *key, const DBT *val, int index,
1.1 schwarze 364: const struct mchars *mc, struct rec *rec)
365: {
366: size_t left;
367: char *np, *cp;
368:
369: #define INDEX_BREAD(_dst) \
370: do { \
371: if (NULL == (np = memchr(cp, '\0', left))) \
372: return(0); \
373: norm_string(cp, mc, &(_dst)); \
374: left -= (np - cp) + 1; \
375: cp = np + 1; \
376: } while (/* CONSTCOND */ 0)
377:
378: left = val->size;
379: cp = (char *)val->data;
380:
1.5 kristaps 381: rec->res.rec = *(recno_t *)key->data;
1.11 kristaps 382: rec->res.volume = index;
1.1 schwarze 383:
1.14 schwarze 384: INDEX_BREAD(rec->res.type);
1.5 kristaps 385: INDEX_BREAD(rec->res.file);
386: INDEX_BREAD(rec->res.cat);
387: INDEX_BREAD(rec->res.title);
388: INDEX_BREAD(rec->res.arch);
389: INDEX_BREAD(rec->res.desc);
1.1 schwarze 390: return(1);
391: }
392:
393: /*
1.10 kristaps 394: * Search mandocdb databases in paths for expression "expr".
1.1 schwarze 395: * Filter out by "opts".
396: * Call "res" with the results, which may be zero.
1.5 kristaps 397: * Return 0 if there was a database error, else return 1.
1.1 schwarze 398: */
1.5 kristaps 399: int
1.10 kristaps 400: apropos_search(int pathsz, char **paths, const struct opts *opts,
1.12 schwarze 401: const struct expr *expr, size_t terms, void *arg,
1.5 kristaps 402: void (*res)(struct res *, size_t, void *))
1.1 schwarze 403: {
1.8 kristaps 404: struct rectree tree;
405: struct mchars *mc;
406: struct res *ress;
407: int i, mlen, rc;
408:
409: memset(&tree, 0, sizeof(struct rectree));
410:
1.10 kristaps 411: rc = 0;
1.8 kristaps 412: mc = mchars_alloc();
413:
1.10 kristaps 414: /*
415: * Main loop. Change into the directory containing manpage
416: * databases. Run our expession over each database in the set.
417: */
418:
419: for (i = 0; i < pathsz; i++) {
420: if (chdir(paths[i]))
1.8 kristaps 421: continue;
1.11 kristaps 422: if ( ! single_search(&tree, opts, expr, terms, mc, i))
1.10 kristaps 423: goto out;
1.8 kristaps 424: }
425:
426: /*
1.10 kristaps 427: * Count matching files, transfer to a "clean" array, then feed
428: * them to the output handler.
1.8 kristaps 429: */
430:
431: for (mlen = i = 0; i < tree.len; i++)
432: if (tree.node[i].matched)
433: mlen++;
434:
435: ress = mandoc_malloc(mlen * sizeof(struct res));
436:
437: for (mlen = i = 0; i < tree.len; i++)
438: if (tree.node[i].matched)
1.12 schwarze 439: memcpy(&ress[mlen++], &tree.node[i].res,
1.8 kristaps 440: sizeof(struct res));
441:
442: (*res)(ress, mlen, arg);
443: free(ress);
444:
1.10 kristaps 445: rc = 1;
446: out:
1.8 kristaps 447: for (i = 0; i < tree.len; i++)
448: recfree(&tree.node[i]);
449:
450: free(tree.node);
451: mchars_free(mc);
452: return(rc);
453: }
454:
455: static int
456: single_search(struct rectree *tree, const struct opts *opts,
457: const struct expr *expr, size_t terms,
1.11 kristaps 458: struct mchars *mc, int vol)
1.8 kristaps 459: {
460: int root, leaf, ch;
1.1 schwarze 461: DBT key, val;
462: DB *btree, *idx;
463: char *buf;
1.5 kristaps 464: struct rec *rs;
465: struct rec r;
1.17 kristaps 466: struct db_val vb;
1.1 schwarze 467:
468: root = -1;
469: leaf = -1;
470: btree = NULL;
471: idx = NULL;
472: buf = NULL;
1.8 kristaps 473: rs = tree->node;
1.1 schwarze 474:
1.5 kristaps 475: memset(&r, 0, sizeof(struct rec));
1.1 schwarze 476:
1.12 schwarze 477: if (NULL == (btree = btree_open()))
1.10 kristaps 478: return(1);
1.1 schwarze 479:
1.8 kristaps 480: if (NULL == (idx = index_open())) {
481: (*btree->close)(btree);
1.10 kristaps 482: return(1);
1.8 kristaps 483: }
1.1 schwarze 484:
485: while (0 == (ch = (*btree->seq)(btree, &key, &val, R_NEXT))) {
1.17 kristaps 486: if ( ! btree_read(&key, &val, mc, &vb, &buf))
1.1 schwarze 487: break;
488:
1.5 kristaps 489: /*
490: * See if this keyword record matches any of the
491: * expressions we have stored.
492: */
1.17 kristaps 493: if ( ! exprmark(expr, buf, vb.mask, NULL))
1.1 schwarze 494: continue;
495:
496: /*
497: * O(log n) scan for prior records. Since a record
498: * number is unbounded, this has decent performance over
499: * a complex hash function.
500: */
501:
502: for (leaf = root; leaf >= 0; )
1.17 kristaps 503: if (vb.rec > rs[leaf].res.rec &&
1.5 kristaps 504: rs[leaf].rhs >= 0)
505: leaf = rs[leaf].rhs;
1.17 kristaps 506: else if (vb.rec < rs[leaf].res.rec &&
1.5 kristaps 507: rs[leaf].lhs >= 0)
508: leaf = rs[leaf].lhs;
1.12 schwarze 509: else
1.1 schwarze 510: break;
511:
1.5 kristaps 512: /*
513: * If we find a record, see if it has already evaluated
514: * to true. If it has, great, just keep going. If not,
515: * try to evaluate it now and continue anyway.
516: */
517:
1.17 kristaps 518: if (leaf >= 0 && rs[leaf].res.rec == vb.rec) {
1.5 kristaps 519: if (0 == rs[leaf].matched)
1.17 kristaps 520: exprexec(expr, buf, vb.mask, &rs[leaf]);
1.1 schwarze 521: continue;
1.5 kristaps 522: }
1.1 schwarze 523:
524: /*
1.5 kristaps 525: * We have a new file to examine.
526: * Extract the manpage's metadata from the index
527: * database, then begin partial evaluation.
1.1 schwarze 528: */
529:
1.17 kristaps 530: key.data = &vb.rec;
1.1 schwarze 531: key.size = sizeof(recno_t);
532:
533: if (0 != (*idx->get)(idx, &key, &val, 0))
534: break;
535:
1.5 kristaps 536: r.lhs = r.rhs = -1;
1.11 kristaps 537: if ( ! index_read(&key, &val, vol, mc, &r))
1.1 schwarze 538: break;
539:
1.5 kristaps 540: /* XXX: this should be elsewhere, I guess? */
541:
542: if (opts->cat && strcasecmp(opts->cat, r.res.cat))
1.1 schwarze 543: continue;
1.5 kristaps 544: if (opts->arch && strcasecmp(opts->arch, r.res.arch))
1.1 schwarze 545: continue;
546:
1.8 kristaps 547: tree->node = rs = mandoc_realloc
548: (rs, (tree->len + 1) * sizeof(struct rec));
1.1 schwarze 549:
1.8 kristaps 550: memcpy(&rs[tree->len], &r, sizeof(struct rec));
1.12 schwarze 551: rs[tree->len].matches =
1.8 kristaps 552: mandoc_calloc(terms, sizeof(int));
1.1 schwarze 553:
1.17 kristaps 554: exprexec(expr, buf, vb.mask, &rs[tree->len]);
1.12 schwarze 555:
1.1 schwarze 556: /* Append to our tree. */
557:
558: if (leaf >= 0) {
1.17 kristaps 559: if (vb.rec > rs[leaf].res.rec)
1.8 kristaps 560: rs[leaf].rhs = tree->len;
1.1 schwarze 561: else
1.8 kristaps 562: rs[leaf].lhs = tree->len;
1.1 schwarze 563: } else
1.8 kristaps 564: root = tree->len;
1.12 schwarze 565:
1.5 kristaps 566: memset(&r, 0, sizeof(struct rec));
1.8 kristaps 567: tree->len++;
1.1 schwarze 568: }
1.12 schwarze 569:
1.8 kristaps 570: (*btree->close)(btree);
571: (*idx->close)(idx);
1.1 schwarze 572:
573: free(buf);
1.8 kristaps 574: return(1 == ch);
1.5 kristaps 575: }
576:
577: static void
578: recfree(struct rec *rec)
579: {
580:
1.17 kristaps 581: free(rec->res.type);
1.5 kristaps 582: free(rec->res.file);
583: free(rec->res.cat);
584: free(rec->res.title);
585: free(rec->res.arch);
586: free(rec->res.desc);
587:
588: free(rec->matches);
1.1 schwarze 589: }
590:
1.13 kristaps 591: /*
592: * Compile a list of straight-up terms.
593: * The arguments are re-written into ~[[:<:]]term[[:>:]], or "term"
594: * surrounded by word boundaries, then pumped through exprterm().
595: * Terms are case-insensitive.
596: * This emulates whatis(1) behaviour.
597: */
598: struct expr *
599: termcomp(int argc, char *argv[], size_t *tt)
600: {
601: char *buf;
602: int pos;
603: struct expr *e, *next;
604: size_t sz;
605:
606: buf = NULL;
607: e = NULL;
608: *tt = 0;
609:
1.15 schwarze 610: for (pos = argc - 1; pos >= 0; pos--) {
611: sz = strlen(argv[pos]) + 18;
1.13 kristaps 612: buf = mandoc_realloc(buf, sz);
1.15 schwarze 613: strlcpy(buf, "Nm~[[:<:]]", sz);
1.13 kristaps 614: strlcat(buf, argv[pos], sz);
615: strlcat(buf, "[[:>:]]", sz);
616: if (NULL == (next = exprterm(buf, 0))) {
617: free(buf);
618: exprfree(e);
619: return(NULL);
620: }
1.15 schwarze 621: next->next = e;
1.13 kristaps 622: e = next;
623: (*tt)++;
624: }
625:
626: free(buf);
627: return(e);
628: }
629:
630: /*
631: * Compile a sequence of logical expressions.
632: * See apropos.1 for a grammar of this sequence.
633: */
1.1 schwarze 634: struct expr *
1.5 kristaps 635: exprcomp(int argc, char *argv[], size_t *tt)
1.1 schwarze 636: {
1.5 kristaps 637: int pos, lvl;
638: struct expr *e;
639:
640: pos = lvl = 0;
641: *tt = 0;
642:
643: e = exprexpr(argc, argv, &pos, &lvl, tt);
644:
645: if (0 == lvl && pos >= argc)
646: return(e);
647:
648: exprfree(e);
649: return(NULL);
650: }
651:
652: /*
653: * Compile an array of tokens into an expression.
654: * An informal expression grammar is defined in apropos(1).
655: * Return NULL if we fail doing so. All memory will be cleaned up.
656: * Return the root of the expression sequence if alright.
657: */
658: static struct expr *
1.9 kristaps 659: exprexpr(int argc, char *argv[], int *pos, int *lvl, size_t *tt)
1.5 kristaps 660: {
661: struct expr *e, *first, *next;
662: int log;
663:
664: first = next = NULL;
665:
666: for ( ; *pos < argc; (*pos)++) {
667: e = next;
668:
669: /*
670: * Close out a subexpression.
671: */
672:
673: if (NULL != e && 0 == strcmp(")", argv[*pos])) {
674: if (--(*lvl) < 0)
675: goto err;
676: break;
677: }
678:
679: /*
680: * Small note: if we're just starting, don't let "-a"
681: * and "-o" be considered logical operators: they're
682: * just tokens unless pairwise joining, in which case we
683: * record their existence (or assume "OR").
684: */
685: log = 0;
686:
687: if (NULL != e && 0 == strcmp("-a", argv[*pos]))
1.12 schwarze 688: log = 1;
1.5 kristaps 689: else if (NULL != e && 0 == strcmp("-o", argv[*pos]))
690: log = 2;
691:
692: if (log > 0 && ++(*pos) >= argc)
693: goto err;
694:
695: /*
696: * Now we parse the term part. This can begin with
697: * "-i", in which case the expression is case
698: * insensitive.
699: */
700:
701: if (0 == strcmp("(", argv[*pos])) {
702: ++(*pos);
703: ++(*lvl);
704: next = mandoc_calloc(1, sizeof(struct expr));
705: next->subexpr = exprexpr(argc, argv, pos, lvl, tt);
706: if (NULL == next->subexpr) {
707: free(next);
708: next = NULL;
709: }
710: } else if (0 == strcmp("-i", argv[*pos])) {
711: if (++(*pos) >= argc)
712: goto err;
713: next = exprterm(argv[*pos], 0);
714: } else
715: next = exprterm(argv[*pos], 1);
716:
717: if (NULL == next)
718: goto err;
719:
720: next->and = log == 1;
721: next->index = (int)(*tt)++;
722:
723: /* Append to our chain of expressions. */
724:
725: if (NULL == first) {
726: assert(NULL == e);
727: first = next;
728: } else {
729: assert(NULL != e);
730: e->next = next;
731: }
732: }
733:
734: return(first);
735: err:
736: exprfree(first);
737: return(NULL);
738: }
739:
740: /*
741: * Parse a terminal expression with the grammar as defined in
742: * apropos(1).
743: * Return NULL if we fail the parse.
744: */
745: static struct expr *
746: exprterm(char *buf, int cs)
747: {
748: struct expr e;
1.1 schwarze 749: struct expr *p;
1.3 schwarze 750: char *key;
1.5 kristaps 751: int i;
752:
753: memset(&e, 0, sizeof(struct expr));
1.1 schwarze 754:
1.5 kristaps 755: /* Choose regex or substring match. */
1.3 schwarze 756:
1.4 kristaps 757: if (NULL == (e.v = strpbrk(buf, "=~"))) {
1.3 schwarze 758: e.regex = 0;
1.4 kristaps 759: e.v = buf;
1.3 schwarze 760: } else {
761: e.regex = '~' == *e.v;
762: *e.v++ = '\0';
763: }
1.1 schwarze 764:
1.5 kristaps 765: /* Determine the record types to search for. */
1.3 schwarze 766:
767: e.mask = 0;
1.4 kristaps 768: if (buf < e.v) {
769: while (NULL != (key = strsep(&buf, ","))) {
1.3 schwarze 770: i = 0;
771: while (types[i].mask &&
1.4 kristaps 772: strcmp(types[i].name, key))
1.3 schwarze 773: i++;
774: e.mask |= types[i].mask;
775: }
776: }
777: if (0 == e.mask)
778: e.mask = TYPE_Nm | TYPE_Nd;
1.1 schwarze 779:
1.5 kristaps 780: if (e.regex) {
1.13 kristaps 781: i = REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE);
1.5 kristaps 782: if (regcomp(&e.re, e.v, i))
783: return(NULL);
784: }
1.1 schwarze 785:
1.3 schwarze 786: e.v = mandoc_strdup(e.v);
1.1 schwarze 787:
788: p = mandoc_calloc(1, sizeof(struct expr));
789: memcpy(p, &e, sizeof(struct expr));
790: return(p);
791: }
792:
793: void
794: exprfree(struct expr *p)
795: {
1.5 kristaps 796: struct expr *pp;
1.12 schwarze 797:
1.5 kristaps 798: while (NULL != p) {
799: if (p->subexpr)
800: exprfree(p->subexpr);
801: if (p->regex)
802: regfree(&p->re);
803: free(p->v);
804: pp = p->next;
805: free(p);
806: p = pp;
807: }
808: }
1.1 schwarze 809:
1.5 kristaps 810: static int
1.12 schwarze 811: exprmark(const struct expr *p, const char *cp,
1.6 kristaps 812: uint64_t mask, int *ms)
1.5 kristaps 813: {
814:
815: for ( ; p; p = p->next) {
816: if (p->subexpr) {
817: if (exprmark(p->subexpr, cp, mask, ms))
818: return(1);
819: continue;
820: } else if ( ! (mask & p->mask))
821: continue;
1.1 schwarze 822:
1.5 kristaps 823: if (p->regex) {
824: if (regexec(&p->re, cp, 0, NULL, 0))
825: continue;
1.16 kristaps 826: } else if (NULL == strcasestr(cp, p->v))
827: continue;
1.5 kristaps 828:
829: if (NULL == ms)
830: return(1);
831: else
832: ms[p->index] = 1;
833: }
1.1 schwarze 834:
1.5 kristaps 835: return(0);
1.1 schwarze 836: }
837:
838: static int
1.5 kristaps 839: expreval(const struct expr *p, int *ms)
1.1 schwarze 840: {
1.5 kristaps 841: int match;
1.1 schwarze 842:
1.5 kristaps 843: /*
844: * AND has precedence over OR. Analysis is left-right, though
845: * it doesn't matter because there are no side-effects.
846: * Thus, step through pairwise ANDs and accumulate their Boolean
847: * evaluation. If we encounter a single true AND collection or
848: * standalone term, the whole expression is true (by definition
849: * of OR).
850: */
851:
852: for (match = 0; p && ! match; p = p->next) {
853: /* Evaluate a subexpression, if applicable. */
854: if (p->subexpr && ! ms[p->index])
855: ms[p->index] = expreval(p->subexpr, ms);
856:
857: match = ms[p->index];
858: for ( ; p->next && p->next->and; p = p->next) {
859: /* Evaluate a subexpression, if applicable. */
860: if (p->next->subexpr && ! ms[p->next->index])
1.12 schwarze 861: ms[p->next->index] =
1.5 kristaps 862: expreval(p->next->subexpr, ms);
863: match = match && ms[p->next->index];
864: }
865: }
866:
867: return(match);
868: }
869:
870: /*
871: * First, update the array of terms for which this expression evaluates
872: * to true.
873: * Second, logically evaluate all terms over the updated array of truth
874: * values.
875: * If this evaluates to true, mark the expression as satisfied.
876: */
877: static void
1.12 schwarze 878: exprexec(const struct expr *e, const char *cp,
1.6 kristaps 879: uint64_t mask, struct rec *r)
1.5 kristaps 880: {
1.1 schwarze 881:
1.5 kristaps 882: assert(0 == r->matched);
1.12 schwarze 883: exprmark(e, cp, mask, r->matches);
884: r->matched = expreval(e, r->matches);
1.1 schwarze 885: }
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