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 */
}