[apple/shell_cmds.git] / sh / arith_yacc.c

/*-
 * Copyright (c) 1993
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 2007
 *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: head/bin/sh/arith_yacc.c 270246 2014-08-20 20:15:43Z jilles $");

#include <limits.h>
#include <errno.h>
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include "arith.h"
#include "arith_yacc.h"
#include "expand.h"
#include "shell.h"
#include "error.h"
#include "memalloc.h"
#include "output.h"
#include "options.h"
#include "var.h"

#if ARITH_BOR + 11 != ARITH_BORASS || ARITH_ASS + 11 != ARITH_EQ
#error Arithmetic tokens are out of order.
#endif

static const char *arith_startbuf;

const char *arith_buf;
union yystype yylval;

static int last_token;

#define ARITH_PRECEDENCE(op, prec) [op - ARITH_BINOP_MIN] = prec

static const char prec[ARITH_BINOP_MAX - ARITH_BINOP_MIN] = {
	ARITH_PRECEDENCE(ARITH_MUL, 0),
	ARITH_PRECEDENCE(ARITH_DIV, 0),
	ARITH_PRECEDENCE(ARITH_REM, 0),
	ARITH_PRECEDENCE(ARITH_ADD, 1),
	ARITH_PRECEDENCE(ARITH_SUB, 1),
	ARITH_PRECEDENCE(ARITH_LSHIFT, 2),
	ARITH_PRECEDENCE(ARITH_RSHIFT, 2),
	ARITH_PRECEDENCE(ARITH_LT, 3),
	ARITH_PRECEDENCE(ARITH_LE, 3),
	ARITH_PRECEDENCE(ARITH_GT, 3),
	ARITH_PRECEDENCE(ARITH_GE, 3),
	ARITH_PRECEDENCE(ARITH_EQ, 4),
	ARITH_PRECEDENCE(ARITH_NE, 4),
	ARITH_PRECEDENCE(ARITH_BAND, 5),
	ARITH_PRECEDENCE(ARITH_BXOR, 6),
	ARITH_PRECEDENCE(ARITH_BOR, 7),
};

#define ARITH_MAX_PREC 8

int letcmd(int, char **);

static __dead2 void yyerror(const char *s)
{
	error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
	/* NOTREACHED */
}

static arith_t arith_lookupvarint(char *varname)
{
	const char *str;
	char *p;
	arith_t result;

	str = lookupvar(varname);
	if (uflag && str == NULL)
		yyerror("variable not set");
	if (str == NULL || *str == '\0')
		str = "0";
	errno = 0;
	result = strtoarith_t(str, &p, 0);
	if (errno != 0 || *p != '\0')
		yyerror("variable conversion error");
	return result;
}

static inline int arith_prec(int op)
{
	return prec[op - ARITH_BINOP_MIN];
}

static inline int higher_prec(int op1, int op2)
{
	return arith_prec(op1) < arith_prec(op2);
}

static arith_t do_binop(int op, arith_t a, arith_t b)
{

	switch (op) {
	default:
	case ARITH_REM:
	case ARITH_DIV:
		if (!b)
			yyerror("division by zero");
		if (a == ARITH_MIN && b == -1)
			yyerror("divide error");
		return op == ARITH_REM ? a % b : a / b;
	case ARITH_MUL:
		return (uintmax_t)a * (uintmax_t)b;
	case ARITH_ADD:
		return (uintmax_t)a + (uintmax_t)b;
	case ARITH_SUB:
		return (uintmax_t)a - (uintmax_t)b;
	case ARITH_LSHIFT:
		return (uintmax_t)a << (b & (sizeof(uintmax_t) * CHAR_BIT - 1));
	case ARITH_RSHIFT:
		return a >> (b & (sizeof(uintmax_t) * CHAR_BIT - 1));
	case ARITH_LT:
		return a < b;
	case ARITH_LE:
		return a <= b;
	case ARITH_GT:
		return a > b;
	case ARITH_GE:
		return a >= b;
	case ARITH_EQ:
		return a == b;
	case ARITH_NE:
		return a != b;
	case ARITH_BAND:
		return a & b;
	case ARITH_BXOR:
		return a ^ b;
	case ARITH_BOR:
		return a | b;
	}
}

static arith_t assignment(int var, int noeval);

static arith_t primary(int token, union yystype *val, int op, int noeval)
{
	arith_t result;

again:
	switch (token) {
	case ARITH_LPAREN:
		result = assignment(op, noeval);
		if (last_token != ARITH_RPAREN)
			yyerror("expecting ')'");
		last_token = yylex();
		return result;
	case ARITH_NUM:
		last_token = op;
		return val->val;
	case ARITH_VAR:
		last_token = op;
		return noeval ? val->val : arith_lookupvarint(val->name);
	case ARITH_ADD:
		token = op;
		*val = yylval;
		op = yylex();
		goto again;
	case ARITH_SUB:
		*val = yylval;
		return -primary(op, val, yylex(), noeval);
	case ARITH_NOT:
		*val = yylval;
		return !primary(op, val, yylex(), noeval);
	case ARITH_BNOT:
		*val = yylval;
		return ~primary(op, val, yylex(), noeval);
	default:
		yyerror("expecting primary");
	}
}

static arith_t binop2(arith_t a, int op, int precedence, int noeval)
{
	for (;;) {
		union yystype val;
		arith_t b;
		int op2;
		int token;

		token = yylex();
		val = yylval;

		b = primary(token, &val, yylex(), noeval);

		op2 = last_token;
		if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
		    higher_prec(op2, op)) {
			b = binop2(b, op2, arith_prec(op), noeval);
			op2 = last_token;
		}

		a = noeval ? b : do_binop(op, a, b);

		if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
		    arith_prec(op2) >= precedence)
			return a;

		op = op2;
	}
}

static arith_t binop(int token, union yystype *val, int op, int noeval)
{
	arith_t a = primary(token, val, op, noeval);

	op = last_token;
	if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
		return a;

	return binop2(a, op, ARITH_MAX_PREC, noeval);
}

static arith_t and(int token, union yystype *val, int op, int noeval)
{
	arith_t a = binop(token, val, op, noeval);
	arith_t b;

	op = last_token;
	if (op != ARITH_AND)
		return a;

	token = yylex();
	*val = yylval;

	b = and(token, val, yylex(), noeval | !a);

	return a && b;
}

static arith_t or(int token, union yystype *val, int op, int noeval)
{
	arith_t a = and(token, val, op, noeval);
	arith_t b;

	op = last_token;
	if (op != ARITH_OR)
		return a;

	token = yylex();
	*val = yylval;

	b = or(token, val, yylex(), noeval | !!a);

	return a || b;
}

static arith_t cond(int token, union yystype *val, int op, int noeval)
{
	arith_t a = or(token, val, op, noeval);
	arith_t b;
	arith_t c;

	if (last_token != ARITH_QMARK)
		return a;

	b = assignment(yylex(), noeval | !a);

	if (last_token != ARITH_COLON)
		yyerror("expecting ':'");

	token = yylex();
	*val = yylval;

	c = cond(token, val, yylex(), noeval | !!a);

	return a ? b : c;
}

static arith_t assignment(int var, int noeval)
{
	union yystype val = yylval;
	int op = yylex();
	arith_t result;
	char sresult[DIGITS(result) + 1];

	if (var != ARITH_VAR)
		return cond(var, &val, op, noeval);

	if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
		return cond(var, &val, op, noeval);

	result = assignment(yylex(), noeval);
	if (noeval)
		return result;

	if (op != ARITH_ASS)
		result = do_binop(op - 11, arith_lookupvarint(val.name), result);
	snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
	setvar(val.name, sresult, 0);
	return result;
}

arith_t arith(const char *s)
{
	struct stackmark smark;
	arith_t result;

	setstackmark(&smark);

	arith_buf = arith_startbuf = s;

	result = assignment(yylex(), 0);

	if (last_token)
		yyerror("expecting EOF");

	popstackmark(&smark);

	return result;
}

/*
 *  The exp(1) builtin.
 */
int
letcmd(int argc, char **argv)
{
	const char *p;
	char *concat;
	char **ap;
	arith_t i;

	if (argc > 1) {
		p = argv[1];
		if (argc > 2) {
			/*
			 * Concatenate arguments.
			 */
			STARTSTACKSTR(concat);
			ap = argv + 2;
			for (;;) {
				while (*p)
					STPUTC(*p++, concat);
				if ((p = *ap++) == NULL)
					break;
				STPUTC(' ', concat);
			}
			STPUTC('\0', concat);
			p = grabstackstr(concat);
		}
	} else
		p = "";

	i = arith(p);

	out1fmt(ARITH_FORMAT_STR "\n", i);
	return !i;
}
Commit	Line	Data
71aad674 A	1	/*-
	2	* Copyright (c) 1993
	3	* The Regents of the University of California. All rights reserved.
	4	* Copyright (c) 2007
	5	* Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved.
	6	*
	7	* This code is derived from software contributed to Berkeley by
	8	* Kenneth Almquist.
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. Neither the name of the University nor the names of its contributors
	19	* may be used to endorse or promote products derived from this software
	20	* without specific prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	* SUCH DAMAGE.
	33	*/
	34
	35	#include <sys/cdefs.h>
deb63bfb	36	__FBSDID("$FreeBSD: head/bin/sh/arith_yacc.c 270246 2014-08-20 20:15:43Z jilles $");
71aad674 A	37
	38	#include <limits.h>
	39	#include <errno.h>
	40	#include <inttypes.h>
	41	#include <stdlib.h>
	42	#include <stdio.h>
	43	#include "arith.h"
	44	#include "arith_yacc.h"
	45	#include "expand.h"
	46	#include "shell.h"
	47	#include "error.h"
	48	#include "memalloc.h"
	49	#include "output.h"
	50	#include "options.h"
	51	#include "var.h"
	52
	53	#if ARITH_BOR + 11 != ARITH_BORASS \|\| ARITH_ASS + 11 != ARITH_EQ
	54	#error Arithmetic tokens are out of order.
	55	#endif
	56
	57	static const char *arith_startbuf;
	58
	59	const char *arith_buf;
	60	union yystype yylval;
	61
	62	static int last_token;
	63
	64	#define ARITH_PRECEDENCE(op, prec) [op - ARITH_BINOP_MIN] = prec
	65
	66	static const char prec[ARITH_BINOP_MAX - ARITH_BINOP_MIN] = {
	67	ARITH_PRECEDENCE(ARITH_MUL, 0),
	68	ARITH_PRECEDENCE(ARITH_DIV, 0),
	69	ARITH_PRECEDENCE(ARITH_REM, 0),
	70	ARITH_PRECEDENCE(ARITH_ADD, 1),
	71	ARITH_PRECEDENCE(ARITH_SUB, 1),
	72	ARITH_PRECEDENCE(ARITH_LSHIFT, 2),
	73	ARITH_PRECEDENCE(ARITH_RSHIFT, 2),
	74	ARITH_PRECEDENCE(ARITH_LT, 3),
	75	ARITH_PRECEDENCE(ARITH_LE, 3),
	76	ARITH_PRECEDENCE(ARITH_GT, 3),
	77	ARITH_PRECEDENCE(ARITH_GE, 3),
	78	ARITH_PRECEDENCE(ARITH_EQ, 4),
	79	ARITH_PRECEDENCE(ARITH_NE, 4),
	80	ARITH_PRECEDENCE(ARITH_BAND, 5),
	81	ARITH_PRECEDENCE(ARITH_BXOR, 6),
	82	ARITH_PRECEDENCE(ARITH_BOR, 7),
	83	};
	84
	85	#define ARITH_MAX_PREC 8
	86
	87	int letcmd(int, char **);
	88
	89	static __dead2 void yyerror(const char *s)
	90	{
	91	error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
	92	/* NOTREACHED */
	93	}
	94
	95	static arith_t arith_lookupvarint(char *varname)
	96	{
	97	const char *str;
	98	char *p;
	99	arith_t result;
	100
101	str = lookupvar(varname);
102	if (uflag && str == NULL)
103	yyerror("variable not set");
104	if (str == NULL \|\| *str == '\0')
105	str = "0";
106	errno = 0;
107	result = strtoarith_t(str, &p, 0);
108	if (errno != 0 \|\| *p != '\0')
109	yyerror("variable conversion error");
110	return result;
111	}
112
113	static inline int arith_prec(int op)
114	{
115	return prec[op - ARITH_BINOP_MIN];
116	}
117
118	static inline int higher_prec(int op1, int op2)
119	{
120	return arith_prec(op1) < arith_prec(op2);
121	}
122
123	static arith_t do_binop(int op, arith_t a, arith_t b)
124	{
125
126	switch (op) {
127	default:
128	case ARITH_REM:
129	case ARITH_DIV:
130	if (!b)
131	yyerror("division by zero");
132	if (a == ARITH_MIN && b == -1)
133	yyerror("divide error");
134	return op == ARITH_REM ? a % b : a / b;
135	case ARITH_MUL:
136	return (uintmax_t)a * (uintmax_t)b;
137	case ARITH_ADD:
138	return (uintmax_t)a + (uintmax_t)b;
139	case ARITH_SUB:
140	return (uintmax_t)a - (uintmax_t)b;
141	case ARITH_LSHIFT:
142	return (uintmax_t)a << (b & (sizeof(uintmax_t) * CHAR_BIT - 1));
143	case ARITH_RSHIFT:
144	return a >> (b & (sizeof(uintmax_t) * CHAR_BIT - 1));
145	case ARITH_LT:
146	return a < b;
147	case ARITH_LE:
148	return a <= b;
149	case ARITH_GT:
150	return a > b;
151	case ARITH_GE:
152	return a >= b;
153	case ARITH_EQ:
154	return a == b;
155	case ARITH_NE:
156	return a != b;
157	case ARITH_BAND:
158	return a & b;
159	case ARITH_BXOR:
160	return a ^ b;
161	case ARITH_BOR:
162	return a \| b;
163	}
164	}
165
166	static arith_t assignment(int var, int noeval);
167
168	static arith_t primary(int token, union yystype *val, int op, int noeval)
169	{
170	arith_t result;
171
172	again:
173	switch (token) {
174	case ARITH_LPAREN:
175	result = assignment(op, noeval);
176	if (last_token != ARITH_RPAREN)
177	yyerror("expecting ')'");
178	last_token = yylex();
179	return result;
180	case ARITH_NUM:
181	last_token = op;
182	return val->val;
183	case ARITH_VAR:
184	last_token = op;
185	return noeval ? val->val : arith_lookupvarint(val->name);
186	case ARITH_ADD:
187	token = op;
188	*val = yylval;
189	op = yylex();
190	goto again;
191	case ARITH_SUB:
192	*val = yylval;
193	return -primary(op, val, yylex(), noeval);
194	case ARITH_NOT:
195	*val = yylval;
196	return !primary(op, val, yylex(), noeval);
197	case ARITH_BNOT:
198	*val = yylval;
199	return ~primary(op, val, yylex(), noeval);
200	default:
201	yyerror("expecting primary");
202	}
203	}
204
205	static arith_t binop2(arith_t a, int op, int precedence, int noeval)
206	{
207	for (;;) {
208	union yystype val;
209	arith_t b;
210	int op2;
211	int token;
212
213	token = yylex();
214	val = yylval;
215
216	b = primary(token, &val, yylex(), noeval);
217
218	op2 = last_token;
219	if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
220	higher_prec(op2, op)) {
221	b = binop2(b, op2, arith_prec(op), noeval);
222	op2 = last_token;
223	}
224
225	a = noeval ? b : do_binop(op, a, b);
226
227	if (op2 < ARITH_BINOP_MIN \|\| op2 >= ARITH_BINOP_MAX \|\|
228	arith_prec(op2) >= precedence)
229	return a;
230
231	op = op2;
232	}
233	}
234
235	static arith_t binop(int token, union yystype *val, int op, int noeval)
236	{
237	arith_t a = primary(token, val, op, noeval);
238
239	op = last_token;
240	if (op < ARITH_BINOP_MIN \|\| op >= ARITH_BINOP_MAX)
241	return a;
242
243	return binop2(a, op, ARITH_MAX_PREC, noeval);
244	}
245
246	static arith_t and(int token, union yystype *val, int op, int noeval)
247	{
248	arith_t a = binop(token, val, op, noeval);
249	arith_t b;
250
251	op = last_token;
252	if (op != ARITH_AND)
253	return a;
254
255	token = yylex();
256	*val = yylval;
257
258	b = and(token, val, yylex(), noeval \| !a);
259
260	return a && b;
261	}
262
263	static arith_t or(int token, union yystype *val, int op, int noeval)
264	{
265	arith_t a = and(token, val, op, noeval);
266	arith_t b;
267
268	op = last_token;
269	if (op != ARITH_OR)
270	return a;
271
272	token = yylex();
273	*val = yylval;
274
275	b = or(token, val, yylex(), noeval \| !!a);
276
277	return a \|\| b;
278	}
279
280	static arith_t cond(int token, union yystype *val, int op, int noeval)
281	{
282	arith_t a = or(token, val, op, noeval);
283	arith_t b;
284	arith_t c;
285
286	if (last_token != ARITH_QMARK)
287	return a;
288
289	b = assignment(yylex(), noeval \| !a);
290
291	if (last_token != ARITH_COLON)
292	yyerror("expecting ':'");
293
294	token = yylex();
295	*val = yylval;
296
297	c = cond(token, val, yylex(), noeval \| !!a);
298
299	return a ? b : c;
300	}
301
302	static arith_t assignment(int var, int noeval)
303	{
304	union yystype val = yylval;
305	int op = yylex();
306	arith_t result;
307	char sresult[DIGITS(result) + 1];
308
309	if (var != ARITH_VAR)
310	return cond(var, &val, op, noeval);
311
312	if (op != ARITH_ASS && (op < ARITH_ASS_MIN \|\| op >= ARITH_ASS_MAX))
313	return cond(var, &val, op, noeval);
314
315	result = assignment(yylex(), noeval);
316	if (noeval)
317	return result;
318
319	if (op != ARITH_ASS)
320	result = do_binop(op - 11, arith_lookupvarint(val.name), result);
321	snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
322	setvar(val.name, sresult, 0);
323	return result;
324	}
325
326	arith_t arith(const char *s)
327	{
328	struct stackmark smark;
329	arith_t result;
330
331	setstackmark(&smark);
332
333	arith_buf = arith_startbuf = s;
334
335	result = assignment(yylex(), 0);
336
337	if (last_token)
338	yyerror("expecting EOF");
339
340	popstackmark(&smark);
341
342	return result;
343	}
344
345	/*
346	* The exp(1) builtin.
347	*/
348	int
349	letcmd(int argc, char **argv)
350	{
351	const char *p;
352	char *concat;
353	char **ap;
354	arith_t i;
355
356	if (argc > 1) {
357	p = argv[1];
358	if (argc > 2) {
359	/*
360	* Concatenate arguments.
361	*/
362	STARTSTACKSTR(concat);
363	ap = argv + 2;
364	for (;;) {
365	while (*p)
366	STPUTC(*p++, concat);
367	if ((p = *ap++) == NULL)
368	break;
369	STPUTC(' ', concat);
370	}
371	STPUTC('\0', concat);
372	p = grabstackstr(concat);
373	}
374	} else
375	p = "";
376
377	i = arith(p);
378
379	out1fmt(ARITH_FORMAT_STR "\n", i);
380	return !i;
381	}