Subversion Repositories HelenOS

%{

/*	$NetBSD: arith.y,v 1.13 1999/07/09 03:05:49 christos Exp $	*/

/*-

 * Copyright (c) 1993

 *	The Regents of the University of California.  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. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *	This product includes software developed by the University of

 *	California, Berkeley and its contributors.

 * 4. 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>

#ifndef lint

#if 0

static char sccsid[] = "@(#)arith.y	8.3 (Berkeley) 5/4/95";

#else

__RCSID("$NetBSD: arith.y,v 1.13 1999/07/09 03:05:49 christos Exp $");

#endif

#endif /* not lint */

#include <stdlib.h>

#include "expand.h"

#include "shell.h"

#include "error.h"

#include "output.h"

#include "memalloc.h"

const char *arith_buf, *arith_startbuf;

void yyerror (const char *);

int yyparse (void);

#ifdef TESTARITH

int main (int , char *[]);

int error (char *);

#endif

int

arith(s)

	const char *s;

{

	long result;

	arith_buf = arith_startbuf = s;

	INTOFF;

	result = yyparse();

	arith_lex_reset();	/* reprime lex */

	INTON;

	return (result);

}

/*

 *  The exp(1) builtin.

 */

int

expcmd(argc, argv)

	int argc;

	char **argv;

{

	const char *p;

	char *concat;

	char **ap;

	long 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("%ld\n", i);

	return (! i);

}

/*************************/

#ifdef TEST_ARITH

#include <stdio.h>

main(argc, argv)

	char *argv[];

{

	printf("%d\n", exp(argv[1]));

}

error(s)

	char *s;

{

	fprintf(stderr, "exp: %s\n", s);

	exit(1);

}

#endif

%}

%token ARITH_NUM ARITH_LPAREN ARITH_RPAREN

%left ARITH_OR

%left ARITH_AND

%left ARITH_BOR

%left ARITH_BXOR

%left ARITH_BAND

%left ARITH_EQ ARITH_NE

%left ARITH_LT ARITH_GT ARITH_GE ARITH_LE

%left ARITH_LSHIFT ARITH_RSHIFT

%left ARITH_ADD ARITH_SUB

%left ARITH_MUL ARITH_DIV ARITH_REM

%left ARITH_UNARYMINUS ARITH_UNARYPLUS ARITH_NOT ARITH_BNOT

%%

exp:	expr {

			return ($1);

		}

	;

expr:	ARITH_LPAREN expr ARITH_RPAREN { $$ = $2; }

	| expr ARITH_OR expr	{ $$ = $1 ? $1 : $3 ? $3 : 0; }

	| expr ARITH_AND expr	{ $$ = $1 ? ( $3 ? $3 : 0 ) : 0; }

	| expr ARITH_BOR expr	{ $$ = $1 | $3; }

	| expr ARITH_BXOR expr	{ $$ = $1 ^ $3; }

	| expr ARITH_BAND expr	{ $$ = $1 & $3; }

	| expr ARITH_EQ expr	{ $$ = $1 == $3; }

	| expr ARITH_GT expr	{ $$ = $1 > $3; }

	| expr ARITH_GE expr	{ $$ = $1 >= $3; }

	| expr ARITH_LT expr	{ $$ = $1 < $3; }

	| expr ARITH_LE expr	{ $$ = $1 <= $3; }

	| expr ARITH_NE expr	{ $$ = $1 != $3; }

	| expr ARITH_LSHIFT expr { $$ = $1 << $3; }

	| expr ARITH_RSHIFT expr { $$ = $1 >> $3; }

	| expr ARITH_ADD expr	{ $$ = $1 + $3; }

	| expr ARITH_SUB expr	{ $$ = $1 - $3; }

	| expr ARITH_MUL expr	{ $$ = $1 * $3; }

	| expr ARITH_DIV expr	{

			if ($3 == 0)

				yyerror("division by zero");

			$$ = $1 / $3;

			}

	| expr ARITH_REM expr   {

			if ($3 == 0)

				yyerror("division by zero");

			$$ = $1 % $3;

			}

	| ARITH_NOT expr	{ $$ = !($2); }

	| ARITH_BNOT expr	{ $$ = ~($2); }

	| ARITH_SUB expr %prec ARITH_UNARYMINUS { $$ = -($2); }

	| ARITH_ADD expr %prec ARITH_UNARYPLUS { $$ = $2; }

	| ARITH_NUM

	;

%%

void

yyerror(s)

	const char *s;

{

	yyclearin;

	arith_lex_reset();	/* reprime lex */

	error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);

	/* NOTREACHED */

}