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1 /*	$OpenBSD: expr.c,v 1.23 2013/12/17 16:37:06 deraadt Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
5  *		 2011, 2012, 2013, 2014
6  *	Thorsten Glaser <tg@mirbsd.org>
7  *
8  * Provided that these terms and disclaimer and all copyright notices
9  * are retained or reproduced in an accompanying document, permission
10  * is granted to deal in this work without restriction, including un-
11  * limited rights to use, publicly perform, distribute, sell, modify,
12  * merge, give away, or sublicence.
13  *
14  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
15  * the utmost extent permitted by applicable law, neither express nor
16  * implied; without malicious intent or gross negligence. In no event
17  * may a licensor, author or contributor be held liable for indirect,
18  * direct, other damage, loss, or other issues arising in any way out
19  * of dealing in the work, even if advised of the possibility of such
20  * damage or existence of a defect, except proven that it results out
21  * of said person's immediate fault when using the work as intended.
22  */
23 
24 #include "sh.h"
25 
26 __RCSID("$MirOS: src/bin/mksh/expr.c,v 1.76 2014/06/24 19:53:19 tg Exp $");
27 
28 /* the order of these enums is constrained by the order of opinfo[] */
29 enum token {
30 	/* some (long) unary operators */
31 	O_PLUSPLUS = 0, O_MINUSMINUS,
32 	/* binary operators */
33 	O_EQ, O_NE,
34 	/* assignments are assumed to be in range O_ASN .. O_BORASN */
35 	O_ASN, O_TIMESASN, O_DIVASN, O_MODASN, O_PLUSASN, O_MINUSASN,
36 #ifndef MKSH_LEGACY_MODE
37 	O_ROLASN, O_RORASN,
38 #endif
39 	O_LSHIFTASN, O_RSHIFTASN, O_BANDASN, O_BXORASN, O_BORASN,
40 	/* binary non-assignment operators */
41 #ifndef MKSH_LEGACY_MODE
42 	O_ROL, O_ROR,
43 #endif
44 	O_LSHIFT, O_RSHIFT,
45 	O_LE, O_GE, O_LT, O_GT,
46 	O_LAND,
47 	O_LOR,
48 	O_TIMES, O_DIV, O_MOD,
49 	O_PLUS, O_MINUS,
50 	O_BAND,
51 	O_BXOR,
52 	O_BOR,
53 	O_TERN,
54 	O_COMMA,
55 	/* things after this aren't used as binary operators */
56 	/* unary that are not also binaries */
57 	O_BNOT, O_LNOT,
58 	/* misc */
59 	OPEN_PAREN, CLOSE_PAREN, CTERN,
60 	/* things that don't appear in the opinfo[] table */
61 	VAR, LIT, END, BAD
62 };
63 #define IS_ASSIGNOP(op)	((int)(op) >= (int)O_ASN && (int)(op) <= (int)O_BORASN)
64 
65 /* precisions; used to be enum prec but we do arithmetics on it */
66 #define P_PRIMARY	0	/* VAR, LIT, (), ! ~ ++ -- */
67 #define P_MULT		1	/* * / % */
68 #define P_ADD		2	/* + - */
69 #define P_SHIFT		3	/* <<< >>> << >> */
70 #define P_RELATION	4	/* < <= > >= */
71 #define P_EQUALITY	5	/* == != */
72 #define P_BAND		6	/* & */
73 #define P_BXOR		7	/* ^ */
74 #define P_BOR		8	/* | */
75 #define P_LAND		9	/* && */
76 #define P_LOR		10	/* || */
77 #define P_TERN		11	/* ?: */
78 	/* = += -= *= /= %= <<<= >>>= <<= >>= &= ^= |= */
79 #define P_ASSIGN	12
80 #define P_COMMA		13	/* , */
81 #define MAX_PREC	P_COMMA
82 
83 struct opinfo {
84 	char name[5];
85 	/* name length */
86 	uint8_t len;
87 	/* precedence: lower is higher */
88 	uint8_t prec;
89 };
90 
91 /*
92  * Tokens in this table must be ordered so the longest are first
93  * (eg, += before +). If you change something, change the order
94  * of enum token too.
95  */
96 static const struct opinfo opinfo[] = {
97 	{ "++",   2, P_PRIMARY },	/* before + */
98 	{ "--",   2, P_PRIMARY },	/* before - */
99 	{ "==",   2, P_EQUALITY },	/* before = */
100 	{ "!=",   2, P_EQUALITY },	/* before ! */
101 	{ "=",    1, P_ASSIGN },	/* keep assigns in a block */
102 	{ "*=",   2, P_ASSIGN },
103 	{ "/=",   2, P_ASSIGN },
104 	{ "%=",   2, P_ASSIGN },
105 	{ "+=",   2, P_ASSIGN },
106 	{ "-=",   2, P_ASSIGN },
107 #ifndef MKSH_LEGACY_MODE
108 	{ "<<<=", 4, P_ASSIGN },	/* before <<< */
109 	{ ">>>=", 4, P_ASSIGN },	/* before >>> */
110 #endif
111 	{ "<<=",  3, P_ASSIGN },
112 	{ ">>=",  3, P_ASSIGN },
113 	{ "&=",   2, P_ASSIGN },
114 	{ "^=",   2, P_ASSIGN },
115 	{ "|=",   2, P_ASSIGN },
116 #ifndef MKSH_LEGACY_MODE
117 	{ "<<<",  3, P_SHIFT },		/* before << */
118 	{ ">>>",  3, P_SHIFT },		/* before >> */
119 #endif
120 	{ "<<",   2, P_SHIFT },
121 	{ ">>",   2, P_SHIFT },
122 	{ "<=",   2, P_RELATION },
123 	{ ">=",   2, P_RELATION },
124 	{ "<",    1, P_RELATION },
125 	{ ">",    1, P_RELATION },
126 	{ "&&",   2, P_LAND },
127 	{ "||",   2, P_LOR },
128 	{ "*",    1, P_MULT },
129 	{ "/",    1, P_MULT },
130 	{ "%",    1, P_MULT },
131 	{ "+",    1, P_ADD },
132 	{ "-",    1, P_ADD },
133 	{ "&",    1, P_BAND },
134 	{ "^",    1, P_BXOR },
135 	{ "|",    1, P_BOR },
136 	{ "?",    1, P_TERN },
137 	{ ",",    1, P_COMMA },
138 	{ "~",    1, P_PRIMARY },
139 	{ "!",    1, P_PRIMARY },
140 	{ "(",    1, P_PRIMARY },
141 	{ ")",    1, P_PRIMARY },
142 	{ ":",    1, P_PRIMARY },
143 	{ "",     0, P_PRIMARY }
144 };
145 
146 typedef struct expr_state {
147 	/* expression being evaluated */
148 	const char *expression;
149 	/* lexical position */
150 	const char *tokp;
151 	/* value from token() */
152 	struct tbl *val;
153 	/* variable that is being recursively expanded (EXPRINEVAL flag set) */
154 	struct tbl *evaling;
155 	/* token from token() */
156 	enum token tok;
157 	/* don't do assignments (for ?:, &&, ||) */
158 	uint8_t noassign;
159 	/* evaluating an $(()) expression? */
160 	bool arith;
161 	/* unsigned arithmetic calculation */
162 	bool natural;
163 } Expr_state;
164 
165 enum error_type {
166 	ET_UNEXPECTED, ET_BADLIT, ET_RECURSIVE,
167 	ET_LVALUE, ET_RDONLY, ET_STR
168 };
169 
170 static void evalerr(Expr_state *, enum error_type, const char *)
171     MKSH_A_NORETURN;
172 static struct tbl *evalexpr(Expr_state *, unsigned int);
173 static void exprtoken(Expr_state *);
174 static struct tbl *do_ppmm(Expr_state *, enum token, struct tbl *, bool);
175 static void assign_check(Expr_state *, enum token, struct tbl *);
176 static struct tbl *intvar(Expr_state *, struct tbl *);
177 
178 /*
179  * parse and evaluate expression
180  */
181 int
evaluate(const char * expr,mksh_ari_t * rval,int error_ok,bool arith)182 evaluate(const char *expr, mksh_ari_t *rval, int error_ok, bool arith)
183 {
184 	struct tbl v;
185 	int ret;
186 
187 	v.flag = DEFINED | INTEGER;
188 	v.type = 0;
189 	ret = v_evaluate(&v, expr, error_ok, arith);
190 	*rval = v.val.i;
191 	return (ret);
192 }
193 
194 /*
195  * parse and evaluate expression, storing result in vp.
196  */
197 int
v_evaluate(struct tbl * vp,const char * expr,volatile int error_ok,bool arith)198 v_evaluate(struct tbl *vp, const char *expr, volatile int error_ok,
199     bool arith)
200 {
201 	struct tbl *v;
202 	Expr_state curstate;
203 	Expr_state * const es = &curstate;
204 	int i;
205 
206 	/* save state to allow recursive calls */
207 	memset(&curstate, 0, sizeof(curstate));
208 	curstate.expression = curstate.tokp = expr;
209 	curstate.tok = BAD;
210 	curstate.arith = arith;
211 
212 	newenv(E_ERRH);
213 	if ((i = kshsetjmp(e->jbuf))) {
214 		/* Clear EXPRINEVAL in of any variables we were playing with */
215 		if (curstate.evaling)
216 			curstate.evaling->flag &= ~EXPRINEVAL;
217 		quitenv(NULL);
218 		if (i == LAEXPR) {
219 			if (error_ok == KSH_RETURN_ERROR)
220 				return (0);
221 			errorfz();
222 		}
223 		unwind(i);
224 		/* NOTREACHED */
225 	}
226 
227 	exprtoken(es);
228 	if (es->tok == END) {
229 		es->tok = LIT;
230 		es->val = tempvar();
231 	}
232 	v = intvar(es, evalexpr(es, MAX_PREC));
233 
234 	if (es->tok != END)
235 		evalerr(es, ET_UNEXPECTED, NULL);
236 
237 	if (es->arith && es->natural)
238 		vp->flag |= INT_U;
239 	if (vp->flag & INTEGER)
240 		setint_v(vp, v, es->arith);
241 	else
242 		/* can fail if readonly */
243 		setstr(vp, str_val(v), error_ok);
244 
245 	quitenv(NULL);
246 
247 	return (1);
248 }
249 
250 static void
evalerr(Expr_state * es,enum error_type type,const char * str)251 evalerr(Expr_state *es, enum error_type type, const char *str)
252 {
253 	char tbuf[2];
254 	const char *s;
255 
256 	es->arith = false;
257 	switch (type) {
258 	case ET_UNEXPECTED:
259 		switch (es->tok) {
260 		case VAR:
261 			s = es->val->name;
262 			break;
263 		case LIT:
264 			s = str_val(es->val);
265 			break;
266 		case END:
267 			s = "end of expression";
268 			break;
269 		case BAD:
270 			tbuf[0] = *es->tokp;
271 			tbuf[1] = '\0';
272 			s = tbuf;
273 			break;
274 		default:
275 			s = opinfo[(int)es->tok].name;
276 		}
277 		warningf(true, "%s: %s '%s'", es->expression,
278 		    "unexpected", s);
279 		break;
280 
281 	case ET_BADLIT:
282 		warningf(true, "%s: %s '%s'", es->expression,
283 		    "bad number", str);
284 		break;
285 
286 	case ET_RECURSIVE:
287 		warningf(true, "%s: %s '%s'", es->expression,
288 		    "expression recurses on parameter", str);
289 		break;
290 
291 	case ET_LVALUE:
292 		warningf(true, "%s: %s %s",
293 		    es->expression, str, "requires lvalue");
294 		break;
295 
296 	case ET_RDONLY:
297 		warningf(true, "%s: %s %s",
298 		    es->expression, str, "applied to read-only variable");
299 		break;
300 
301 	default: /* keep gcc happy */
302 	case ET_STR:
303 		warningf(true, "%s: %s", es->expression, str);
304 		break;
305 	}
306 	unwind(LAEXPR);
307 }
308 
309 /* do a ++ or -- operation */
310 static struct tbl *
do_ppmm(Expr_state * es,enum token op,struct tbl * vasn,bool is_prefix)311 do_ppmm(Expr_state *es, enum token op, struct tbl *vasn, bool is_prefix)
312 {
313 	struct tbl *vl;
314 	mksh_uari_t oval;
315 
316 	assign_check(es, op, vasn);
317 
318 	vl = intvar(es, vasn);
319 	oval = vl->val.u;
320 	if (op == O_PLUSPLUS)
321 		++vl->val.u;
322 	else
323 		--vl->val.u;
324 	if (!es->noassign) {
325 		if (vasn->flag & INTEGER)
326 			setint_v(vasn, vl, es->arith);
327 		else
328 			setint(vasn, vl->val.i);
329 	}
330 	if (!is_prefix)
331 		/* undo the increment/decrement */
332 		vl->val.u = oval;
333 
334 	return (vl);
335 }
336 
337 static struct tbl *
evalexpr(Expr_state * es,unsigned int prec)338 evalexpr(Expr_state *es, unsigned int prec)
339 {
340 	struct tbl *vl, *vr = NULL, *vasn;
341 	enum token op;
342 	mksh_uari_t res = 0, t1, t2, t3;
343 
344 	if (prec == P_PRIMARY) {
345 		switch ((int)(op = es->tok)) {
346 		case O_BNOT:
347 		case O_LNOT:
348 		case O_MINUS:
349 		case O_PLUS:
350 			exprtoken(es);
351 			vl = intvar(es, evalexpr(es, P_PRIMARY));
352 			switch ((int)op) {
353 			case O_BNOT:
354 				vl->val.u = ~vl->val.u;
355 				break;
356 			case O_LNOT:
357 				vl->val.u = !vl->val.u;
358 				break;
359 			case O_MINUS:
360 				vl->val.u = -vl->val.u;
361 				break;
362 			case O_PLUS:
363 				/* nop */
364 				break;
365 			}
366 			break;
367 
368 		case OPEN_PAREN:
369 			exprtoken(es);
370 			vl = evalexpr(es, MAX_PREC);
371 			if (es->tok != CLOSE_PAREN)
372 				evalerr(es, ET_STR, "missing )");
373 			exprtoken(es);
374 			break;
375 
376 		case O_PLUSPLUS:
377 		case O_MINUSMINUS:
378 			exprtoken(es);
379 			vl = do_ppmm(es, op, es->val, true);
380 			exprtoken(es);
381 			break;
382 
383 		case VAR:
384 		case LIT:
385 			vl = es->val;
386 			exprtoken(es);
387 			break;
388 
389 		default:
390 			evalerr(es, ET_UNEXPECTED, NULL);
391 			/* NOTREACHED */
392 		}
393 
394 		if (es->tok == O_PLUSPLUS || es->tok == O_MINUSMINUS) {
395 			vl = do_ppmm(es, es->tok, vl, false);
396 			exprtoken(es);
397 		}
398 
399 		return (vl);
400 		/* prec == P_PRIMARY */
401 	}
402 
403 	vl = evalexpr(es, prec - 1);
404 	while ((int)(op = es->tok) >= (int)O_EQ && (int)op <= (int)O_COMMA &&
405 	    opinfo[(int)op].prec == prec) {
406 		exprtoken(es);
407 		vasn = vl;
408 		if (op != O_ASN)
409 			/* vl may not have a value yet */
410 			vl = intvar(es, vl);
411 		if (IS_ASSIGNOP(op)) {
412 			if (!es->noassign)
413 				assign_check(es, op, vasn);
414 			vr = intvar(es, evalexpr(es, P_ASSIGN));
415 		} else if (op == O_TERN) {
416 			bool ev = vl->val.u != 0;
417 
418 			if (!ev)
419 				es->noassign++;
420 			vl = evalexpr(es, MAX_PREC);
421 			if (!ev)
422 				es->noassign--;
423 			if (es->tok != CTERN)
424 				evalerr(es, ET_STR, "missing :");
425 			exprtoken(es);
426 			if (ev)
427 				es->noassign++;
428 			vr = evalexpr(es, P_TERN);
429 			if (ev)
430 				es->noassign--;
431 			vl = ev ? vl : vr;
432 			continue;
433 		} else if (op != O_LAND && op != O_LOR)
434 			vr = intvar(es, evalexpr(es, prec - 1));
435 
436 		/* common ops setup */
437 		switch ((int)op) {
438 		case O_DIV:
439 		case O_DIVASN:
440 		case O_MOD:
441 		case O_MODASN:
442 			if (vr->val.u == 0) {
443 				if (!es->noassign)
444 					evalerr(es, ET_STR, "zero divisor");
445 				vr->val.u = 1;
446 			}
447 			/* calculate the absolute values */
448 			t1 = vl->val.i < 0 ? -vl->val.u : vl->val.u;
449 			t2 = vr->val.i < 0 ? -vr->val.u : vr->val.u;
450 			break;
451 #ifndef MKSH_LEGACY_MODE
452 		case O_LSHIFT:
453 		case O_LSHIFTASN:
454 		case O_RSHIFT:
455 		case O_RSHIFTASN:
456 		case O_ROL:
457 		case O_ROLASN:
458 		case O_ROR:
459 		case O_RORASN:
460 			t1 = vl->val.u;
461 			t2 = vr->val.u & 31;
462 			break;
463 #endif
464 		case O_LAND:
465 		case O_LOR:
466 			t1 = vl->val.u;
467 			t2 = 0;	/* gcc */
468 			break;
469 		default:
470 			t1 = vl->val.u;
471 			t2 = vr->val.u;
472 			break;
473 		}
474 
475 #define cmpop(op)	(es->natural ?			\
476 	(mksh_uari_t)(vl->val.u op vr->val.u) :		\
477 	(mksh_uari_t)(vl->val.i op vr->val.i)		\
478 )
479 
480 		/* op calculation */
481 		switch ((int)op) {
482 		case O_TIMES:
483 		case O_TIMESASN:
484 			res = t1 * t2;
485 			break;
486 		case O_MOD:
487 		case O_MODASN:
488 			if (es->natural) {
489 				res = vl->val.u % vr->val.u;
490 				break;
491 			}
492 			goto signed_division;
493 		case O_DIV:
494 		case O_DIVASN:
495 			if (es->natural) {
496 				res = vl->val.u / vr->val.u;
497 				break;
498 			}
499  signed_division:
500 			/*
501 			 * a / b = abs(a) / abs(b) * sgn((u)a^(u)b)
502 			 */
503 			t3 = t1 / t2;
504 #ifndef MKSH_LEGACY_MODE
505 			res = ((vl->val.u ^ vr->val.u) & 0x80000000) ? -t3 : t3;
506 #else
507 			res = ((t1 == vl->val.u ? 0 : 1) ^
508 			    (t2 == vr->val.u ? 0 : 1)) ? -t3 : t3;
509 #endif
510 			if (op == O_MOD || op == O_MODASN) {
511 				/*
512 				 * primitive modulo, to get the sign of
513 				 * the result correct:
514 				 * (a % b) = a - ((a / b) * b)
515 				 * the subtraction and multiplication
516 				 * are, amazingly enough, sign ignorant
517 				 */
518 				res = vl->val.u - (res * vr->val.u);
519 			}
520 			break;
521 		case O_PLUS:
522 		case O_PLUSASN:
523 			res = t1 + t2;
524 			break;
525 		case O_MINUS:
526 		case O_MINUSASN:
527 			res = t1 - t2;
528 			break;
529 #ifndef MKSH_LEGACY_MODE
530 		case O_ROL:
531 		case O_ROLASN:
532 			res = (t1 << t2) | (t1 >> (32 - t2));
533 			break;
534 		case O_ROR:
535 		case O_RORASN:
536 			res = (t1 >> t2) | (t1 << (32 - t2));
537 			break;
538 #endif
539 		case O_LSHIFT:
540 		case O_LSHIFTASN:
541 			res = t1 << t2;
542 			break;
543 		case O_RSHIFT:
544 		case O_RSHIFTASN:
545 			res = es->natural || vl->val.i >= 0 ?
546 			    t1 >> t2 :
547 			    ~(~t1 >> t2);
548 			break;
549 		case O_LT:
550 			res = cmpop(<);
551 			break;
552 		case O_LE:
553 			res = cmpop(<=);
554 			break;
555 		case O_GT:
556 			res = cmpop(>);
557 			break;
558 		case O_GE:
559 			res = cmpop(>=);
560 			break;
561 		case O_EQ:
562 			res = t1 == t2;
563 			break;
564 		case O_NE:
565 			res = t1 != t2;
566 			break;
567 		case O_BAND:
568 		case O_BANDASN:
569 			res = t1 & t2;
570 			break;
571 		case O_BXOR:
572 		case O_BXORASN:
573 			res = t1 ^ t2;
574 			break;
575 		case O_BOR:
576 		case O_BORASN:
577 			res = t1 | t2;
578 			break;
579 		case O_LAND:
580 			if (!t1)
581 				es->noassign++;
582 			vr = intvar(es, evalexpr(es, prec - 1));
583 			res = t1 && vr->val.u;
584 			if (!t1)
585 				es->noassign--;
586 			break;
587 		case O_LOR:
588 			if (t1)
589 				es->noassign++;
590 			vr = intvar(es, evalexpr(es, prec - 1));
591 			res = t1 || vr->val.u;
592 			if (t1)
593 				es->noassign--;
594 			break;
595 		case O_ASN:
596 		case O_COMMA:
597 			res = t2;
598 			break;
599 		}
600 
601 #undef cmpop
602 
603 		if (IS_ASSIGNOP(op)) {
604 			vr->val.u = res;
605 			if (!es->noassign) {
606 				if (vasn->flag & INTEGER)
607 					setint_v(vasn, vr, es->arith);
608 				else
609 					setint(vasn, vr->val.i);
610 			}
611 			vl = vr;
612 		} else
613 			vl->val.u = res;
614 	}
615 	return (vl);
616 }
617 
618 static void
exprtoken(Expr_state * es)619 exprtoken(Expr_state *es)
620 {
621 	const char *cp = es->tokp;
622 	int c;
623 	char *tvar;
624 
625 	/* skip whitespace */
626  skip_spaces:
627 	while ((c = *cp), ksh_isspace(c))
628 		++cp;
629 	if (es->tokp == es->expression && c == '#') {
630 		/* expression begins with # */
631 		/* switch to unsigned */
632 		es->natural = true;
633 		++cp;
634 		goto skip_spaces;
635 	}
636 	es->tokp = cp;
637 
638 	if (c == '\0')
639 		es->tok = END;
640 	else if (ksh_isalphx(c)) {
641 		for (; ksh_isalnux(c); c = *cp)
642 			cp++;
643 		if (c == '[') {
644 			size_t len;
645 
646 			len = array_ref_len(cp);
647 			if (len == 0)
648 				evalerr(es, ET_STR, "missing ]");
649 			cp += len;
650 		}
651 		if (es->noassign) {
652 			es->val = tempvar();
653 			es->val->flag |= EXPRLVALUE;
654 		} else {
655 			strndupx(tvar, es->tokp, cp - es->tokp, ATEMP);
656 			es->val = global(tvar);
657 			afree(tvar, ATEMP);
658 		}
659 		es->tok = VAR;
660 	} else if (c == '1' && cp[1] == '#') {
661 		cp += 2;
662 		cp += utf_ptradj(cp);
663 		strndupx(tvar, es->tokp, cp - es->tokp, ATEMP);
664 		goto process_tvar;
665 #ifndef MKSH_SMALL
666 	} else if (c == '\'') {
667 		++cp;
668 		cp += utf_ptradj(cp);
669 		if (*cp++ != '\'')
670 			evalerr(es, ET_STR,
671 			    "multi-character character constant");
672 		/* 'x' -> 1#x (x = one multibyte character) */
673 		c = cp - es->tokp;
674 		tvar = alloc(c + /* NUL */ 1, ATEMP);
675 		tvar[0] = '1';
676 		tvar[1] = '#';
677 		memcpy(tvar + 2, es->tokp + 1, c - 2);
678 		tvar[c] = '\0';
679 		goto process_tvar;
680 #endif
681 	} else if (ksh_isdigit(c)) {
682 		while (c != '_' && (ksh_isalnux(c) || c == '#'))
683 			c = *cp++;
684 		strndupx(tvar, es->tokp, --cp - es->tokp, ATEMP);
685  process_tvar:
686 		es->val = tempvar();
687 		es->val->flag &= ~INTEGER;
688 		es->val->type = 0;
689 		es->val->val.s = tvar;
690 		if (setint_v(es->val, es->val, es->arith) == NULL)
691 			evalerr(es, ET_BADLIT, tvar);
692 		afree(tvar, ATEMP);
693 		es->tok = LIT;
694 	} else {
695 		int i, n0;
696 
697 		for (i = 0; (n0 = opinfo[i].name[0]); i++)
698 			if (c == n0 && strncmp(cp, opinfo[i].name,
699 			    (size_t)opinfo[i].len) == 0) {
700 				es->tok = (enum token)i;
701 				cp += opinfo[i].len;
702 				break;
703 			}
704 		if (!n0)
705 			es->tok = BAD;
706 	}
707 	es->tokp = cp;
708 }
709 
710 static void
assign_check(Expr_state * es,enum token op,struct tbl * vasn)711 assign_check(Expr_state *es, enum token op, struct tbl *vasn)
712 {
713 	if (es->tok == END || !vasn ||
714 	    (vasn->name[0] == '\0' && !(vasn->flag & EXPRLVALUE)))
715 		evalerr(es, ET_LVALUE, opinfo[(int)op].name);
716 	else if (vasn->flag & RDONLY)
717 		evalerr(es, ET_RDONLY, opinfo[(int)op].name);
718 }
719 
720 struct tbl *
tempvar(void)721 tempvar(void)
722 {
723 	struct tbl *vp;
724 
725 	vp = alloc(sizeof(struct tbl), ATEMP);
726 	vp->flag = ISSET|INTEGER;
727 	vp->type = 0;
728 	vp->areap = ATEMP;
729 	vp->ua.hval = 0;
730 	vp->val.i = 0;
731 	vp->name[0] = '\0';
732 	return (vp);
733 }
734 
735 /* cast (string) variable to temporary integer variable */
736 static struct tbl *
intvar(Expr_state * es,struct tbl * vp)737 intvar(Expr_state *es, struct tbl *vp)
738 {
739 	struct tbl *vq;
740 
741 	/* try to avoid replacing a temp var with another temp var */
742 	if (vp->name[0] == '\0' &&
743 	    (vp->flag & (ISSET|INTEGER|EXPRLVALUE)) == (ISSET|INTEGER))
744 		return (vp);
745 
746 	vq = tempvar();
747 	if (setint_v(vq, vp, es->arith) == NULL) {
748 		if (vp->flag & EXPRINEVAL)
749 			evalerr(es, ET_RECURSIVE, vp->name);
750 		es->evaling = vp;
751 		vp->flag |= EXPRINEVAL;
752 		v_evaluate(vq, str_val(vp), KSH_UNWIND_ERROR, es->arith);
753 		vp->flag &= ~EXPRINEVAL;
754 		es->evaling = NULL;
755 	}
756 	return (vq);
757 }
758 
759 
760 /*
761  * UTF-8 support code: high-level functions
762  */
763 
764 int
utf_widthadj(const char * src,const char ** dst)765 utf_widthadj(const char *src, const char **dst)
766 {
767 	size_t len;
768 	unsigned int wc;
769 	int width;
770 
771 	if (!UTFMODE || (len = utf_mbtowc(&wc, src)) == (size_t)-1 ||
772 	    wc == 0)
773 		len = width = 1;
774 	else if ((width = utf_wcwidth(wc)) < 0)
775 		/* XXX use 2 for x_zotc3 here? */
776 		width = 1;
777 
778 	if (dst)
779 		*dst = src + len;
780 	return (width);
781 }
782 
783 size_t
utf_mbswidth(const char * s)784 utf_mbswidth(const char *s)
785 {
786 	size_t len, width = 0;
787 	unsigned int wc;
788 	int cw;
789 
790 	if (!UTFMODE)
791 		return (strlen(s));
792 
793 	while (*s)
794 		if (((len = utf_mbtowc(&wc, s)) == (size_t)-1) ||
795 		    ((cw = utf_wcwidth(wc)) == -1)) {
796 			s++;
797 			width += 1;
798 		} else {
799 			s += len;
800 			width += cw;
801 		}
802 	return (width);
803 }
804 
805 const char *
utf_skipcols(const char * p,int cols)806 utf_skipcols(const char *p, int cols)
807 {
808 	int c = 0;
809 
810 	while (c < cols) {
811 		if (!*p)
812 			return (p + cols - c);
813 		c += utf_widthadj(p, &p);
814 	}
815 	return (p);
816 }
817 
818 size_t
utf_ptradj(const char * src)819 utf_ptradj(const char *src)
820 {
821 	register size_t n;
822 
823 	if (!UTFMODE ||
824 	    *(const unsigned char *)(src) < 0xC2 ||
825 	    (n = utf_mbtowc(NULL, src)) == (size_t)-1)
826 		n = 1;
827 	return (n);
828 }
829 
830 /*
831  * UTF-8 support code: low-level functions
832  */
833 
834 /* CESU-8 multibyte and wide character conversion crafted for mksh */
835 
836 size_t
utf_mbtowc(unsigned int * dst,const char * src)837 utf_mbtowc(unsigned int *dst, const char *src)
838 {
839 	const unsigned char *s = (const unsigned char *)src;
840 	unsigned int c, wc;
841 
842 	if ((wc = *s++) < 0x80) {
843  out:
844 		if (dst != NULL)
845 			*dst = wc;
846 		return (wc ? ((const char *)s - src) : 0);
847 	}
848 	if (wc < 0xC2 || wc >= 0xF0)
849 		/* < 0xC0: spurious second byte */
850 		/* < 0xC2: non-minimalistic mapping error in 2-byte seqs */
851 		/* > 0xEF: beyond BMP */
852 		goto ilseq;
853 
854 	if (wc < 0xE0) {
855 		wc = (wc & 0x1F) << 6;
856 		if (((c = *s++) & 0xC0) != 0x80)
857 			goto ilseq;
858 		wc |= c & 0x3F;
859 		goto out;
860 	}
861 
862 	wc = (wc & 0x0F) << 12;
863 
864 	if (((c = *s++) & 0xC0) != 0x80)
865 		goto ilseq;
866 	wc |= (c & 0x3F) << 6;
867 
868 	if (((c = *s++) & 0xC0) != 0x80)
869 		goto ilseq;
870 	wc |= c & 0x3F;
871 
872 	/* Check for non-minimalistic mapping error in 3-byte seqs */
873 	if (wc >= 0x0800 && wc <= 0xFFFD)
874 		goto out;
875  ilseq:
876 	return ((size_t)(-1));
877 }
878 
879 size_t
utf_wctomb(char * dst,unsigned int wc)880 utf_wctomb(char *dst, unsigned int wc)
881 {
882 	unsigned char *d;
883 
884 	if (wc < 0x80) {
885 		*dst = wc;
886 		return (1);
887 	}
888 
889 	d = (unsigned char *)dst;
890 	if (wc < 0x0800)
891 		*d++ = (wc >> 6) | 0xC0;
892 	else {
893 		*d++ = ((wc = wc > 0xFFFD ? 0xFFFD : wc) >> 12) | 0xE0;
894 		*d++ = ((wc >> 6) & 0x3F) | 0x80;
895 	}
896 	*d++ = (wc & 0x3F) | 0x80;
897 	return ((char *)d - dst);
898 }
899 
900 /*
901  * Wrapper around access(2) because it says root can execute everything
902  * on some operating systems. Does not set errno, no user needs it. Use
903  * this iff mode can have the X_OK bit set, access otherwise.
904  */
905 int
ksh_access(const char * fn,int mode)906 ksh_access(const char *fn, int mode)
907 {
908 	int rv;
909 	struct stat sb;
910 
911 	if ((rv = access(fn, mode)) == 0 && kshuid == 0 && (mode & X_OK) &&
912 	    (rv = stat(fn, &sb)) == 0 && !S_ISDIR(sb.st_mode) &&
913 	    (sb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
914 		rv = -1;
915 
916 	return (rv);
917 }
918 
919 /* From: X11/xc/programs/xterm/wcwidth.c,v 1.8 2014/06/24 19:53:53 tg Exp $ */
920 
921 struct mb_ucsrange {
922 	unsigned short beg;
923 	unsigned short end;
924 };
925 
926 static int mb_ucsbsearch(const struct mb_ucsrange arr[], size_t elems,
927     unsigned int val) MKSH_A_PURE;
928 
929 /*
930  * Generated by MirOS: contrib/code/Snippets/eawparse,v 1.2 2013/11/30 13:45:17 tg Exp $
931  * from the Unicode Character Database, Version 7.0.0
932  */
933 
934 static const struct mb_ucsrange mb_ucs_combining[] = {
935 	{ 0x0300, 0x036F },
936 	{ 0x0483, 0x0489 },
937 	{ 0x0591, 0x05BD },
938 	{ 0x05BF, 0x05BF },
939 	{ 0x05C1, 0x05C2 },
940 	{ 0x05C4, 0x05C5 },
941 	{ 0x05C7, 0x05C7 },
942 	{ 0x0600, 0x0605 },
943 	{ 0x0610, 0x061A },
944 	{ 0x061C, 0x061C },
945 	{ 0x064B, 0x065F },
946 	{ 0x0670, 0x0670 },
947 	{ 0x06D6, 0x06DD },
948 	{ 0x06DF, 0x06E4 },
949 	{ 0x06E7, 0x06E8 },
950 	{ 0x06EA, 0x06ED },
951 	{ 0x070F, 0x070F },
952 	{ 0x0711, 0x0711 },
953 	{ 0x0730, 0x074A },
954 	{ 0x07A6, 0x07B0 },
955 	{ 0x07EB, 0x07F3 },
956 	{ 0x0816, 0x0819 },
957 	{ 0x081B, 0x0823 },
958 	{ 0x0825, 0x0827 },
959 	{ 0x0829, 0x082D },
960 	{ 0x0859, 0x085B },
961 	{ 0x08E4, 0x0902 },
962 	{ 0x093A, 0x093A },
963 	{ 0x093C, 0x093C },
964 	{ 0x0941, 0x0948 },
965 	{ 0x094D, 0x094D },
966 	{ 0x0951, 0x0957 },
967 	{ 0x0962, 0x0963 },
968 	{ 0x0981, 0x0981 },
969 	{ 0x09BC, 0x09BC },
970 	{ 0x09C1, 0x09C4 },
971 	{ 0x09CD, 0x09CD },
972 	{ 0x09E2, 0x09E3 },
973 	{ 0x0A01, 0x0A02 },
974 	{ 0x0A3C, 0x0A3C },
975 	{ 0x0A41, 0x0A42 },
976 	{ 0x0A47, 0x0A48 },
977 	{ 0x0A4B, 0x0A4D },
978 	{ 0x0A51, 0x0A51 },
979 	{ 0x0A70, 0x0A71 },
980 	{ 0x0A75, 0x0A75 },
981 	{ 0x0A81, 0x0A82 },
982 	{ 0x0ABC, 0x0ABC },
983 	{ 0x0AC1, 0x0AC5 },
984 	{ 0x0AC7, 0x0AC8 },
985 	{ 0x0ACD, 0x0ACD },
986 	{ 0x0AE2, 0x0AE3 },
987 	{ 0x0B01, 0x0B01 },
988 	{ 0x0B3C, 0x0B3C },
989 	{ 0x0B3F, 0x0B3F },
990 	{ 0x0B41, 0x0B44 },
991 	{ 0x0B4D, 0x0B4D },
992 	{ 0x0B56, 0x0B56 },
993 	{ 0x0B62, 0x0B63 },
994 	{ 0x0B82, 0x0B82 },
995 	{ 0x0BC0, 0x0BC0 },
996 	{ 0x0BCD, 0x0BCD },
997 	{ 0x0C00, 0x0C00 },
998 	{ 0x0C3E, 0x0C40 },
999 	{ 0x0C46, 0x0C48 },
1000 	{ 0x0C4A, 0x0C4D },
1001 	{ 0x0C55, 0x0C56 },
1002 	{ 0x0C62, 0x0C63 },
1003 	{ 0x0C81, 0x0C81 },
1004 	{ 0x0CBC, 0x0CBC },
1005 	{ 0x0CBF, 0x0CBF },
1006 	{ 0x0CC6, 0x0CC6 },
1007 	{ 0x0CCC, 0x0CCD },
1008 	{ 0x0CE2, 0x0CE3 },
1009 	{ 0x0D01, 0x0D01 },
1010 	{ 0x0D41, 0x0D44 },
1011 	{ 0x0D4D, 0x0D4D },
1012 	{ 0x0D62, 0x0D63 },
1013 	{ 0x0DCA, 0x0DCA },
1014 	{ 0x0DD2, 0x0DD4 },
1015 	{ 0x0DD6, 0x0DD6 },
1016 	{ 0x0E31, 0x0E31 },
1017 	{ 0x0E34, 0x0E3A },
1018 	{ 0x0E47, 0x0E4E },
1019 	{ 0x0EB1, 0x0EB1 },
1020 	{ 0x0EB4, 0x0EB9 },
1021 	{ 0x0EBB, 0x0EBC },
1022 	{ 0x0EC8, 0x0ECD },
1023 	{ 0x0F18, 0x0F19 },
1024 	{ 0x0F35, 0x0F35 },
1025 	{ 0x0F37, 0x0F37 },
1026 	{ 0x0F39, 0x0F39 },
1027 	{ 0x0F71, 0x0F7E },
1028 	{ 0x0F80, 0x0F84 },
1029 	{ 0x0F86, 0x0F87 },
1030 	{ 0x0F8D, 0x0F97 },
1031 	{ 0x0F99, 0x0FBC },
1032 	{ 0x0FC6, 0x0FC6 },
1033 	{ 0x102D, 0x1030 },
1034 	{ 0x1032, 0x1037 },
1035 	{ 0x1039, 0x103A },
1036 	{ 0x103D, 0x103E },
1037 	{ 0x1058, 0x1059 },
1038 	{ 0x105E, 0x1060 },
1039 	{ 0x1071, 0x1074 },
1040 	{ 0x1082, 0x1082 },
1041 	{ 0x1085, 0x1086 },
1042 	{ 0x108D, 0x108D },
1043 	{ 0x109D, 0x109D },
1044 	{ 0x1160, 0x11FF },
1045 	{ 0x135D, 0x135F },
1046 	{ 0x1712, 0x1714 },
1047 	{ 0x1732, 0x1734 },
1048 	{ 0x1752, 0x1753 },
1049 	{ 0x1772, 0x1773 },
1050 	{ 0x17B4, 0x17B5 },
1051 	{ 0x17B7, 0x17BD },
1052 	{ 0x17C6, 0x17C6 },
1053 	{ 0x17C9, 0x17D3 },
1054 	{ 0x17DD, 0x17DD },
1055 	{ 0x180B, 0x180E },
1056 	{ 0x18A9, 0x18A9 },
1057 	{ 0x1920, 0x1922 },
1058 	{ 0x1927, 0x1928 },
1059 	{ 0x1932, 0x1932 },
1060 	{ 0x1939, 0x193B },
1061 	{ 0x1A17, 0x1A18 },
1062 	{ 0x1A1B, 0x1A1B },
1063 	{ 0x1A56, 0x1A56 },
1064 	{ 0x1A58, 0x1A5E },
1065 	{ 0x1A60, 0x1A60 },
1066 	{ 0x1A62, 0x1A62 },
1067 	{ 0x1A65, 0x1A6C },
1068 	{ 0x1A73, 0x1A7C },
1069 	{ 0x1A7F, 0x1A7F },
1070 	{ 0x1AB0, 0x1ABE },
1071 	{ 0x1B00, 0x1B03 },
1072 	{ 0x1B34, 0x1B34 },
1073 	{ 0x1B36, 0x1B3A },
1074 	{ 0x1B3C, 0x1B3C },
1075 	{ 0x1B42, 0x1B42 },
1076 	{ 0x1B6B, 0x1B73 },
1077 	{ 0x1B80, 0x1B81 },
1078 	{ 0x1BA2, 0x1BA5 },
1079 	{ 0x1BA8, 0x1BA9 },
1080 	{ 0x1BAB, 0x1BAD },
1081 	{ 0x1BE6, 0x1BE6 },
1082 	{ 0x1BE8, 0x1BE9 },
1083 	{ 0x1BED, 0x1BED },
1084 	{ 0x1BEF, 0x1BF1 },
1085 	{ 0x1C2C, 0x1C33 },
1086 	{ 0x1C36, 0x1C37 },
1087 	{ 0x1CD0, 0x1CD2 },
1088 	{ 0x1CD4, 0x1CE0 },
1089 	{ 0x1CE2, 0x1CE8 },
1090 	{ 0x1CED, 0x1CED },
1091 	{ 0x1CF4, 0x1CF4 },
1092 	{ 0x1CF8, 0x1CF9 },
1093 	{ 0x1DC0, 0x1DF5 },
1094 	{ 0x1DFC, 0x1DFF },
1095 	{ 0x200B, 0x200F },
1096 	{ 0x202A, 0x202E },
1097 	{ 0x2060, 0x2064 },
1098 	{ 0x2066, 0x206F },
1099 	{ 0x20D0, 0x20F0 },
1100 	{ 0x2CEF, 0x2CF1 },
1101 	{ 0x2D7F, 0x2D7F },
1102 	{ 0x2DE0, 0x2DFF },
1103 	{ 0x302A, 0x302D },
1104 	{ 0x3099, 0x309A },
1105 	{ 0xA66F, 0xA672 },
1106 	{ 0xA674, 0xA67D },
1107 	{ 0xA69F, 0xA69F },
1108 	{ 0xA6F0, 0xA6F1 },
1109 	{ 0xA802, 0xA802 },
1110 	{ 0xA806, 0xA806 },
1111 	{ 0xA80B, 0xA80B },
1112 	{ 0xA825, 0xA826 },
1113 	{ 0xA8C4, 0xA8C4 },
1114 	{ 0xA8E0, 0xA8F1 },
1115 	{ 0xA926, 0xA92D },
1116 	{ 0xA947, 0xA951 },
1117 	{ 0xA980, 0xA982 },
1118 	{ 0xA9B3, 0xA9B3 },
1119 	{ 0xA9B6, 0xA9B9 },
1120 	{ 0xA9BC, 0xA9BC },
1121 	{ 0xA9E5, 0xA9E5 },
1122 	{ 0xAA29, 0xAA2E },
1123 	{ 0xAA31, 0xAA32 },
1124 	{ 0xAA35, 0xAA36 },
1125 	{ 0xAA43, 0xAA43 },
1126 	{ 0xAA4C, 0xAA4C },
1127 	{ 0xAA7C, 0xAA7C },
1128 	{ 0xAAB0, 0xAAB0 },
1129 	{ 0xAAB2, 0xAAB4 },
1130 	{ 0xAAB7, 0xAAB8 },
1131 	{ 0xAABE, 0xAABF },
1132 	{ 0xAAC1, 0xAAC1 },
1133 	{ 0xAAEC, 0xAAED },
1134 	{ 0xAAF6, 0xAAF6 },
1135 	{ 0xABE5, 0xABE5 },
1136 	{ 0xABE8, 0xABE8 },
1137 	{ 0xABED, 0xABED },
1138 	{ 0xFB1E, 0xFB1E },
1139 	{ 0xFE00, 0xFE0F },
1140 	{ 0xFE20, 0xFE2D },
1141 	{ 0xFEFF, 0xFEFF },
1142 	{ 0xFFF9, 0xFFFB }
1143 };
1144 
1145 static const struct mb_ucsrange mb_ucs_fullwidth[] = {
1146 	{ 0x1100, 0x115F },
1147 	{ 0x2329, 0x232A },
1148 	{ 0x2E80, 0x303E },
1149 	{ 0x3040, 0xA4CF },
1150 	{ 0xA960, 0xA97F },
1151 	{ 0xAC00, 0xD7A3 },
1152 	{ 0xF900, 0xFAFF },
1153 	{ 0xFE10, 0xFE19 },
1154 	{ 0xFE30, 0xFE6F },
1155 	{ 0xFF00, 0xFF60 },
1156 	{ 0xFFE0, 0xFFE6 }
1157 };
1158 
1159 /* simple binary search in ranges, with bounds optimisation */
1160 static int
mb_ucsbsearch(const struct mb_ucsrange arr[],size_t elems,unsigned int val)1161 mb_ucsbsearch(const struct mb_ucsrange arr[], size_t elems, unsigned int val)
1162 {
1163 	size_t min = 0, mid, max = elems;
1164 
1165 	if (val < arr[min].beg || val > arr[max - 1].end)
1166 		return (0);
1167 
1168 	while (min < max) {
1169 		mid = (min + max) / 2;
1170 
1171 		if (val < arr[mid].beg)
1172 			max = mid;
1173 		else if (val > arr[mid].end)
1174 			min = mid + 1;
1175 		else
1176 			return (1);
1177 	}
1178 	return (0);
1179 }
1180 
1181 /* Unix column width of a wide character (Unicode code point, really) */
1182 int
utf_wcwidth(unsigned int wc)1183 utf_wcwidth(unsigned int wc)
1184 {
1185 	/* except NUL, C0/C1 control characters and DEL yield -1 */
1186 	if (wc < 0x20 || (wc >= 0x7F && wc < 0xA0))
1187 		return (wc ? -1 : 0);
1188 
1189 	/* combining characters use 0 screen columns */
1190 	if (mb_ucsbsearch(mb_ucs_combining, NELEM(mb_ucs_combining), wc))
1191 		return (0);
1192 
1193 	/* all others use 1 or 2 screen columns */
1194 	if (mb_ucsbsearch(mb_ucs_fullwidth, NELEM(mb_ucs_fullwidth), wc))
1195 		return (2);
1196 	return (1);
1197 }
1198