xref: /minix/usr.bin/checknr/checknr.c (revision ebfedea0)
1 /*	$NetBSD: checknr.c,v 1.24 2013/08/12 14:03:18 joerg Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1980, 1993\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)checknr.c	8.1 (Berkeley) 6/6/93";
41 #else
42 __RCSID("$NetBSD: checknr.c,v 1.24 2013/08/12 14:03:18 joerg Exp $");
43 #endif
44 #endif /* not lint */
45 
46 /*
47  * checknr: check an nroff/troff input file for matching macro calls.
48  * we also attempt to match size and font changes, but only the embedded
49  * kind.  These must end in \s0 and \fP resp.  Maybe more sophistication
50  * later but for now think of these restrictions as contributions to
51  * structured typesetting.
52  */
53 #include <ctype.h>
54 #include <err.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 
59 #define MAXSTK	100	/* Stack size */
60 #define MAXBR	100	/* Max number of bracket pairs known */
61 #define MAXCMDS	500	/* Max number of commands known */
62 
63 /*
64  * The stack on which we remember what we've seen so far.
65  */
66 static struct stkstr {
67 	int opno;	/* number of opening bracket */
68 	int pl;		/* '+', '-', ' ' for \s, 1 for \f, 0 for .ft */
69 	int parm;	/* parm to size, font, etc */
70 	int lno;	/* line number the thing came in in */
71 } stk[MAXSTK];
72 static int stktop;
73 
74 /*
75  * The kinds of opening and closing brackets.
76  */
77 static struct brstr {
78 	const char *opbr;
79 	const char *clbr;
80 } br[MAXBR] = {
81 	/* A few bare bones troff commands */
82 #define SZ	0
83 	{ "sz",	"sz"},	/* also \s */
84 #define FT	1
85 	{ "ft",	"ft"},	/* also \f */
86 	/* the -mm package */
87 	{"AL",	"LE"},
88 	{"AS",	"AE"},
89 	{"BL",	"LE"},
90 	{"BS",	"BE"},
91 	{"DF",	"DE"},
92 	{"DL",	"LE"},
93 	{"DS",	"DE"},
94 	{"FS",	"FE"},
95 	{"ML",	"LE"},
96 	{"NS",	"NE"},
97 	{"RL",	"LE"},
98 	{"VL",	"LE"},
99 	/* the -ms package */
100 	{"AB",	"AE"},
101 	{"BD",	"DE"},
102 	{"CD",	"DE"},
103 	{"DS",	"DE"},
104 	{"FS",	"FE"},
105 	{"ID",	"DE"},
106 	{"KF",	"KE"},
107 	{"KS",	"KE"},
108 	{"LD",	"DE"},
109 	{"LG",	"NL"},
110 	{"QS",	"QE"},
111 	{"RS",	"RE"},
112 	{"SM",	"NL"},
113 	{"XA",	"XE"},
114 	{"XS",	"XE"},
115 	/* The -me package */
116 	{"(b",	")b"},
117 	{"(c",	")c"},
118 	{"(d",	")d"},
119 	{"(f",	")f"},
120 	{"(l",	")l"},
121 	{"(q",	")q"},
122 	{"(x",	")x"},
123 	{"(z",	")z"},
124 	/* The -mdoc package */
125 	{"Ao",  "Ac"},
126 	{"Bd",  "Ed"},
127 	{"Bk",  "Ek"},
128 	{"Bo",  "Bc"},
129 	{"Do",  "Dc"},
130 	{"Fo",  "Fc"},
131 	{"Oo",  "Oc"},
132 	{"Po",  "Pc"},
133 	{"Qo",  "Qc"},
134 	{"Rs",  "Re"},
135 	{"So",  "Sc"},
136 	{"Xo",  "Xc"},
137 	/* Things needed by preprocessors */
138 	{"EQ",	"EN"},
139 	{"TS",	"TE"},
140 	/* Refer */
141 	{"[",	"]"},
142 	{0,	0}
143 };
144 
145 /*
146  * All commands known to nroff, plus macro packages.
147  * Used so we can complain about unrecognized commands.
148  */
149 static const char *knowncmds[MAXCMDS] = {
150 "$c", "$f", "$h", "$p", "$s", "%A", "%B", "%C", "%D", "%I", "%J", "%N",
151 "%O", "%P", "%Q", "%R", "%T", "%V", "(b", "(c", "(d", "(f", "(l", "(q",
152 "(t", "(x", "(z", ")b", ")c", ")d", ")f", ")l", ")q", ")t", ")x",
153 ")z", "++", "+c", "1C", "1c", "2C", "2c", "@(", "@)", "@C", "@D",
154 "@F", "@I", "@M", "@c", "@e", "@f", "@h", "@m", "@n", "@o", "@p",
155 "@r", "@t", "@z", "AB", "AE", "AF", "AI", "AL", "AM", "AS", "AT",
156 "AU", "AX", "Ac", "Ad", "An", "Ao", "Ap", "Aq", "Ar", "At", "B" ,  "B1",
157 "B2", "BD", "BE", "BG", "BL", "BS", "BT", "BX", "Bc", "Bd", "Bf",
158 "Bk", "Bl", "Bo", "Bq", "Bsx", "Bx", "C1", "C2", "CD", "CM", "CT",
159 "Cd", "Cm", "D" , "D1", "DA", "DE", "DF", "DL", "DS", "DT", "Db", "Dc",
160 "Dd", "Dl", "Do", "Dq", "Dt", "Dv", "EC", "EF", "EG", "EH", "EM",
161 "EN", "EQ", "EX", "Ec", "Ed", "Ef", "Ek", "El", "Em", "Eo", "Er",
162 "Ev", "FA", "FD", "FE", "FG", "FJ", "FK", "FL", "FN", "FO", "FQ",
163 "FS", "FV", "FX", "Fa", "Fc", "Fd", "Fl", "Fn", "Fo", "Ft", "Fx",
164 "H" , "HC", "HD", "HM", "HO", "HU", "I" , "ID", "IE", "IH", "IM",
165 "IP", "IX", "IZ", "Ic", "In", "It", "KD", "KE", "KF", "KQ", "KS", "LB",
166 "LC", "LD", "LE", "LG", "LI", "LP", "Lb", "Li", "MC", "ME", "MF",
167 "MH", "ML", "MR", "MT", "ND", "NE", "NH", "NL", "NP", "NS", "Nd",
168 "Nm", "No", "Ns", "Nx", "OF", "OH", "OK", "OP", "Oc", "Oo", "Op",
169 "Os", "Ot", "Ox", "P" , "P1", "PF", "PH", "PP", "PT", "PX", "PY",
170 "Pa", "Pc", "Pf", "Po", "Pp", "Pq", "QE", "QP", "QS", "Qc", "Ql",
171 "Qo", "Qq", "R" , "RA", "RC", "RE", "RL", "RP", "RQ", "RS", "RT",
172 "Re", "Rs", "S" , "S0", "S2", "S3", "SA", "SG", "SH", "SK", "SM",
173 "SP", "SY", "Sc", "Sh", "Sm", "So", "Sq", "Ss", "St", "Sx", "Sy",
174 "T&", "TA", "TB", "TC", "TD", "TE", "TH", "TL", "TM", "TP", "TQ",
175 "TR", "TS", "TX", "Tn", "UL", "US", "UX", "Ud", "Ux", "VL", "Va", "Vt",
176 "WC", "WH", "XA", "XD", "XE", "XF", "XK", "XP", "XS", "Xc", "Xo",
177 "Xr", "[" , "[-", "[0", "[1", "[2", "[3", "[4", "[5", "[<", "[>",
178 "[]", "\\{", "\\}", "]" , "]-", "]<", "]>", "][", "ab", "ac", "ad", "af", "am",
179 "ar", "as", "b" , "ba", "bc", "bd", "bi", "bl", "bp", "br", "bx",
180 "c.", "c2", "cc", "ce", "cf", "ch", "cs", "ct", "cu", "da", "de",
181 "di", "dl", "dn", "ds", "dt", "dw", "dy", "ec", "ef", "eh", "el",
182 "em", "eo", "ep", "ev", "ex", "fc", "fi", "fl", "fo", "fp", "ft",
183 "fz", "hc", "he", "hl", "hp", "ht", "hw", "hx", "hy", "i" , "ie",
184 "if", "ig", "in", "ip", "it", "ix", "lc", "lg", "li", "ll", "ln",
185 "lo", "lp", "ls", "lt", "m1", "m2", "m3", "m4", "mc", "mk", "mo",
186 "n1", "n2", "na", "ne", "nf", "nh", "nl", "nm", "nn", "np", "nr",
187 "ns", "nx", "of", "oh", "os", "pa", "pc", "pi", "pl", "pm", "pn",
188 "po", "pp", "ps", "q" , "r" , "rb", "rd", "re", "rm", "rn", "ro",
189 "rr", "rs", "rt", "sb", "sc", "sh", "sk", "so", "sp", "ss", "st",
190 "sv", "sz", "ta", "tc", "th", "ti", "tl", "tm", "tp", "tr", "u",
191 "uf", "uh", "ul", "vs", "wh", "xp", "yr", 0
192 };
193 
194 static int lineno;		/* current line number in input file */
195 static const char *cfilename;	/* name of current file */
196 static int nfiles;		/* number of files to process */
197 static int fflag;		/* -f: ignore \f */
198 static int sflag;		/* -s: ignore \s */
199 static int ncmds;		/* size of knowncmds */
200 static int slot;		/* slot in knowncmds found by binsrch */
201 
202 static void addcmd(char *);
203 static void addmac(const char *);
204 static int binsrch(const char *);
205 static void checkknown(const char *);
206 static void chkcmd(const char *);
207 static void complain(int);
208 static int eq(const char *, const char *);
209 static void nomatch(const char *);
210 static void pe(int);
211 static void process(FILE *);
212 static void prop(int);
213 static void usage(void) __dead;
214 
215 int
216 main(int argc, char **argv)
217 {
218 	FILE *f;
219 	int i;
220 	char *cp;
221 	char b1[4];
222 
223 	/* Figure out how many known commands there are */
224 	while (knowncmds[ncmds])
225 		ncmds++;
226 	while (argc > 1 && argv[1][0] == '-') {
227 		switch(argv[1][1]) {
228 
229 		/* -a: add pairs of macros */
230 		case 'a':
231 			i = strlen(argv[1]) - 2;
232 			if (i % 6 != 0)
233 				usage();
234 			/* look for empty macro slots */
235 			for (i=0; br[i].opbr; i++)
236 				;
237 			for (cp=argv[1]+3; cp[-1]; cp += 6) {
238 				char *tmp;
239 
240 				if (i >= MAXBR)
241 					errx(1, "too many pairs");
242 				if ((tmp = malloc(3)) == NULL)
243 					err(1, "malloc");
244 				strlcpy(tmp, cp, 3);
245 				br[i].opbr = tmp;
246 				if ((tmp = malloc(3)) == NULL)
247 					err(1, "malloc");
248 				strlcpy(tmp, cp+3, 3);
249 				br[i].clbr = tmp;
250 				addmac(br[i].opbr);	/* knows pairs are also known cmds */
251 				addmac(br[i].clbr);
252 				i++;
253 			}
254 			break;
255 
256 		/* -c: add known commands */
257 		case 'c':
258 			i = strlen(argv[1]) - 2;
259 			if (i % 3 != 0)
260 				usage();
261 			for (cp=argv[1]+3; cp[-1]; cp += 3) {
262 				if (cp[2] && cp[2] != '.')
263 					usage();
264 				strncpy(b1, cp, 2);
265 				addmac(b1);
266 			}
267 			break;
268 
269 		/* -f: ignore font changes */
270 		case 'f':
271 			fflag = 1;
272 			break;
273 
274 		/* -s: ignore size changes */
275 		case 's':
276 			sflag = 1;
277 			break;
278 		default:
279 			usage();
280 		}
281 		argc--; argv++;
282 	}
283 
284 	nfiles = argc - 1;
285 
286 	if (nfiles > 0) {
287 		for (i=1; i<argc; i++) {
288 			cfilename = argv[i];
289 			f = fopen(cfilename, "r");
290 			if (f == NULL)
291 				perror(cfilename);
292 			else {
293 				process(f);
294 				fclose(f);
295 			}
296 		}
297 	} else {
298 		cfilename = "stdin";
299 		process(stdin);
300 	}
301 	exit(0);
302 }
303 
304 static void
305 usage(void)
306 {
307 	(void)fprintf(stderr,
308 	    "usage: %s [-fs] [-a.xx.yy.xx.yy...] [-c.xx.xx.xx...] file\n",
309 	    getprogname());
310 	exit(1);
311 }
312 
313 static void
314 process(FILE *f)
315 {
316 	int i, n;
317 	char line[256];	/* the current line */
318 	char mac[5];	/* The current macro or nroff command */
319 	int pl;
320 
321 	stktop = -1;
322 	for (lineno = 1; fgets(line, sizeof line, f); lineno++) {
323 		if (line[0] == '.') {
324 			/*
325 			 * find and isolate the macro/command name.
326 			 */
327 			strncpy(mac, line+1, 4);
328 			if (isspace((unsigned char)mac[0])) {
329 				pe(lineno);
330 				printf("Empty command\n");
331 			} else if (isspace((unsigned char)mac[1])) {
332 				mac[1] = 0;
333 			} else if (isspace((unsigned char)mac[2])) {
334 				mac[2] = 0;
335 			} else if (mac[0] != '\\' || mac[1] != '\"') {
336 				pe(lineno);
337 				printf("Command too long\n");
338 			}
339 
340 			/*
341 			 * Is it a known command?
342 			 */
343 			checkknown(mac);
344 
345 			/*
346 			 * Should we add it?
347 			 */
348 			if (eq(mac, "de"))
349 				addcmd(line);
350 
351 			chkcmd(mac);
352 		}
353 
354 		/*
355 		 * At this point we process the line looking
356 		 * for \s and \f.
357 		 */
358 		for (i=0; line[i]; i++)
359 			if (line[i]=='\\' && (i==0 || line[i-1]!='\\')) {
360 				if (!sflag && line[++i]=='s') {
361 					pl = line[++i];
362 					if (isdigit((unsigned char)pl)) {
363 						n = pl - '0';
364 						pl = ' ';
365 					} else
366 						n = 0;
367 					while (isdigit((unsigned char)line[++i]))
368 						n = 10 * n + line[i] - '0';
369 					i--;
370 					if (n == 0) {
371 						if (stktop >= 0 &&
372 						    stk[stktop].opno == SZ) {
373 							stktop--;
374 						} else {
375 							pe(lineno);
376 							printf("unmatched \\s0\n");
377 						}
378 					} else {
379 						stk[++stktop].opno = SZ;
380 						stk[stktop].pl = pl;
381 						stk[stktop].parm = n;
382 						stk[stktop].lno = lineno;
383 					}
384 				} else if (!fflag && line[i]=='f') {
385 					n = line[++i];
386 					if (n == 'P') {
387 						if (stktop >= 0 &&
388 						    stk[stktop].opno == FT) {
389 							stktop--;
390 						} else {
391 							pe(lineno);
392 							printf("unmatched \\fP\n");
393 						}
394 					} else {
395 						stk[++stktop].opno = FT;
396 						stk[stktop].pl = 1;
397 						stk[stktop].parm = n;
398 						stk[stktop].lno = lineno;
399 					}
400 				}
401 			}
402 	}
403 	/*
404 	 * We've hit the end and look at all this stuff that hasn't been
405 	 * matched yet!  Complain, complain.
406 	 */
407 	for (i=stktop; i>=0; i--) {
408 		complain(i);
409 	}
410 }
411 
412 static void
413 complain(int i)
414 {
415 	pe(stk[i].lno);
416 	printf("Unmatched ");
417 	prop(i);
418 	printf("\n");
419 }
420 
421 static void
422 prop(int i)
423 {
424 	if (stk[i].pl == 0)
425 		printf(".%s", br[stk[i].opno].opbr);
426 	else switch(stk[i].opno) {
427 	case SZ:
428 		printf("\\s%c%d", stk[i].pl, stk[i].parm);
429 		break;
430 	case FT:
431 		printf("\\f%c", stk[i].parm);
432 		break;
433 	default:
434 		printf("Bug: stk[%d].opno = %d = .%s, .%s",
435 			i, stk[i].opno, br[stk[i].opno].opbr,
436 			br[stk[i].opno].clbr);
437 	}
438 }
439 
440 static void
441 chkcmd(const char *mac)
442 {
443 	int i;
444 
445 	/*
446 	 * Check to see if it matches top of stack.
447 	 */
448 	if (stktop >= 0 && eq(mac, br[stk[stktop].opno].clbr))
449 		stktop--;	/* OK. Pop & forget */
450 	else {
451 		/* No. Maybe it's an opener */
452 		for (i=0; br[i].opbr; i++) {
453 			if (eq(mac, br[i].opbr)) {
454 				/* Found. Push it. */
455 				stktop++;
456 				stk[stktop].opno = i;
457 				stk[stktop].pl = 0;
458 				stk[stktop].parm = 0;
459 				stk[stktop].lno = lineno;
460 				break;
461 			}
462 			/*
463 			 * Maybe it's an unmatched closer.
464 			 * NOTE: this depends on the fact
465 			 * that none of the closers can be
466 			 * openers too.
467 			 */
468 			if (eq(mac, br[i].clbr)) {
469 				nomatch(mac);
470 				break;
471 			}
472 		}
473 	}
474 }
475 
476 static void
477 nomatch(const char *mac)
478 {
479 	int i, j;
480 
481 	/*
482 	 * Look for a match further down on stack
483 	 * If we find one, it suggests that the stuff in
484 	 * between is supposed to match itself.
485 	 */
486 	for (j=stktop; j>=0; j--)
487 		if (eq(mac,br[stk[j].opno].clbr)) {
488 			/* Found.  Make a good diagnostic. */
489 			if (j == stktop-2) {
490 				/*
491 				 * Check for special case \fx..\fR and don't
492 				 * complain.
493 				 */
494 				if (stk[j+1].opno==FT && stk[j+1].parm!='R'
495 				 && stk[j+2].opno==FT && stk[j+2].parm=='R') {
496 					stktop = j -1;
497 					return;
498 				}
499 				/*
500 				 * We have two unmatched frobs.  Chances are
501 				 * they were intended to match, so we mention
502 				 * them together.
503 				 */
504 				pe(stk[j+1].lno);
505 				prop(j+1);
506 				printf(" does not match %d: ", stk[j+2].lno);
507 				prop(j+2);
508 				printf("\n");
509 			} else for (i=j+1; i <= stktop; i++) {
510 				complain(i);
511 			}
512 			stktop = j-1;
513 			return;
514 		}
515 	/* Didn't find one.  Throw this away. */
516 	pe(lineno);
517 	printf("Unmatched .%s\n", mac);
518 }
519 
520 /* eq: are two strings equal? */
521 static int
522 eq(const char *s1, const char *s2)
523 {
524 	return strcmp(s1, s2) == 0;
525 }
526 
527 /* print the first part of an error message, given the line number */
528 static void
529 pe(int pelineno)
530 {
531 	if (nfiles > 1)
532 		printf("%s: ", cfilename);
533 	printf("%d: ", pelineno);
534 }
535 
536 static void
537 checkknown(const char *mac)
538 {
539 
540 	if (eq(mac, "."))
541 		return;
542 	if (binsrch(mac) >= 0)
543 		return;
544 	if (mac[0] == '\\' && mac[1] == '"')	/* comments */
545 		return;
546 
547 	pe(lineno);
548 	printf("Unknown command: .%s\n", mac);
549 }
550 
551 /*
552  * We have a .de xx line in "line".  Add xx to the list of known commands.
553  */
554 static void
555 addcmd(char *line)
556 {
557 	char *mac;
558 
559 	/* grab the macro being defined */
560 	mac = line+4;
561 	while (isspace((unsigned char)*mac))
562 		mac++;
563 	if (*mac == 0) {
564 		pe(lineno);
565 		printf("illegal define: %s\n", line);
566 		return;
567 	}
568 	mac[2] = 0;
569 	if (isspace((unsigned char)mac[1]) || mac[1] == '\\')
570 		mac[1] = 0;
571 	if (ncmds >= MAXCMDS) {
572 		printf("Only %d known commands allowed\n", MAXCMDS);
573 		exit(1);
574 	}
575 	addmac(mac);
576 }
577 
578 /*
579  * Add mac to the list.  We should really have some kind of tree
580  * structure here but this is a quick-and-dirty job and I just don't
581  * have time to mess with it.  (I wonder if this will come back to haunt
582  * me someday?)  Anyway, I claim that .de is fairly rare in user
583  * nroff programs, and the register loop below is pretty fast.
584  */
585 static void
586 addmac(const char *mac)
587 {
588 	const char **src, **dest, **loc;
589 
590 	if (binsrch(mac) >= 0){	/* it's OK to redefine something */
591 #ifdef DEBUG
592 		printf("binsrch(%s) -> already in table\n", mac);
593 #endif /* DEBUG */
594 		return;
595 	}
596 	/* binsrch sets slot as a side effect */
597 #ifdef DEBUG
598 	printf("binsrch(%s) -> %d\n", mac, slot);
599 #endif
600 	loc = &knowncmds[slot];
601 	src = &knowncmds[ncmds-1];
602 	dest = src+1;
603 	while (dest > loc)
604 		*dest-- = *src--;
605 	if ((*loc = strdup(mac)) == NULL)
606 		err(1, "strdup");
607 	ncmds++;
608 #ifdef DEBUG
609 	printf("after: %s %s %s %s %s, %d cmds\n", knowncmds[slot-2],
610 	    knowncmds[slot-1], knowncmds[slot], knowncmds[slot+1],
611 	    knowncmds[slot+2], ncmds);
612 #endif
613 }
614 
615 /*
616  * Do a binary search in knowncmds for mac.
617  * If found, return the index.  If not, return -1.
618  */
619 static int
620 binsrch(const char *mac)
621 {
622 	const char *p;	/* pointer to current cmd in list */
623 	int d;		/* difference if any */
624 	int mid;	/* mid point in binary search */
625 	int top, bot;	/* boundaries of bin search, inclusive */
626 
627 	top = ncmds-1;
628 	bot = 0;
629 	while (top >= bot) {
630 		mid = (top+bot)/2;
631 		p = knowncmds[mid];
632 		d = p[0] - mac[0];
633 		if (d == 0)
634 			d = p[1] - mac[1];
635 		if (d == 0)
636 			return mid;
637 		if (d < 0)
638 			bot = mid + 1;
639 		else
640 			top = mid - 1;
641 	}
642 	slot = bot;	/* place it would have gone */
643 	return -1;
644 }
645