1%{
2/* $OpenBSD: parser.y,v 1.7 2012/04/12 17:00:11 espie Exp $ */
3/*
4 * Copyright (c) 2004 Marc Espie <espie@cvs.openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 *
18 * $FreeBSD$
19 */
20
21#include <math.h>
22#include <stdint.h>
23#define YYSTYPE	int32_t
24extern int32_t end_result;
25extern int yylex(void);
26extern int yyerror(const char *);
27%}
28%token NUMBER
29%token ERROR
30%left LOR
31%left LAND
32%left '|'
33%left '^'
34%left '&'
35%left EQ NE
36%left '<' LE '>' GE
37%left LSHIFT RSHIFT
38%left '+' '-'
39%left '*' '/' '%'
40%right EXPONENT
41%right UMINUS UPLUS '!' '~'
42
43%%
44
45top	: expr { end_result = $1; }
46	;
47expr 	: expr '+' expr { $$ = $1 + $3; }
48     	| expr '-' expr { $$ = $1 - $3; }
49	| expr EXPONENT expr { $$ = pow($1, $3); }
50     	| expr '*' expr { $$ = $1 * $3; }
51	| expr '/' expr {
52		if ($3 == 0) {
53			yyerror("division by zero");
54			exit(1);
55		}
56		$$ = $1 / $3;
57	}
58	| expr '%' expr {
59		if ($3 == 0) {
60			yyerror("modulo zero");
61			exit(1);
62		}
63		$$ = $1 % $3;
64	}
65	| expr LSHIFT expr { $$ = $1 << $3; }
66	| expr RSHIFT expr { $$ = $1 >> $3; }
67	| expr '<' expr { $$ = $1 < $3; }
68	| expr '>' expr { $$ = $1 > $3; }
69	| expr LE expr { $$ = $1 <= $3; }
70	| expr GE expr { $$ = $1 >= $3; }
71	| expr EQ expr { $$ = $1 == $3; }
72	| expr NE expr { $$ = $1 != $3; }
73	| expr '&' expr { $$ = $1 & $3; }
74	| expr '^' expr { $$ = $1 ^ $3; }
75	| expr '|' expr { $$ = $1 | $3; }
76	| expr LAND expr { $$ = $1 && $3; }
77	| expr LOR expr { $$ = $1 || $3; }
78	| '(' expr ')' { $$ = $2; }
79	| '-' expr %prec UMINUS { $$ = -$2; }
80	| '+' expr %prec UPLUS  { $$ = $2; }
81	| '!' expr { $$ = !$2; }
82	| '~' expr { $$ = ~$2; }
83	| NUMBER
84	;
85%%
86
87