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| -rw-r--r-- | src/arith.y | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/src/arith.y b/src/arith.y new file mode 100644 index 0000000..be836c8 --- /dev/null +++ b/src/arith.y @@ -0,0 +1,208 @@ +%{ +/* $NetBSD: arith.y,v 1.15 2002/11/24 22:35:39 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 1.15 2002/11/24 22:35:39 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; + +#ifndef YYBISON +int yyparse(void); +#endif +void yyerror(const char *); +#ifdef TESTARITH +int main(int , char *[]); +int error(char *); +#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 || $3; } + | expr ARITH_AND expr { $$ = $1 && $3; } + | expr ARITH_BOR expr { $$ = $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 + ; +%% +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 = nullstr; + + 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 + +void +yyerror(s) + const char *s; +{ + +#ifndef YYBISON + yyerrok; +#endif + yyclearin; + arith_lex_reset(); /* reprime lex */ + error("arithmetic expression: %s: \"%s\"", s, arith_startbuf); + /* NOTREACHED */ +} |