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|
%{
/* $OpenBSD: parser.y,v 1.7 2012/04/12 17:00:11 espie Exp $ */
/*
* Copyright (c) 2004 Marc Espie <espie@cvs.openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* $FreeBSD$
*/
#include <math.h>
#include <stdint.h>
#define YYSTYPE int32_t
extern int32_t end_result;
extern int yylex(void);
extern int yyerror(const char *);
%}
%token NUMBER
%token ERROR
%left LOR
%left LAND
%left '|'
%left '^'
%left '&'
%left EQ NE
%left '<' LE '>' GE
%left LSHIFT RSHIFT
%left '+' '-'
%left '*' '/' '%'
%right EXPONENT
%right UMINUS UPLUS '!' '~'
%%
top : expr { end_result = $1; }
;
expr : expr '+' expr { $$ = $1 + $3; }
| expr '-' expr { $$ = $1 - $3; }
| expr EXPONENT expr { $$ = pow($1, $3); }
| expr '*' expr { $$ = $1 * $3; }
| expr '/' expr {
if ($3 == 0) {
yyerror("division by zero");
exit(1);
}
$$ = $1 / $3;
}
| expr '%' expr {
if ($3 == 0) {
yyerror("modulo zero");
exit(1);
}
$$ = $1 % $3;
}
| expr LSHIFT expr { $$ = $1 << $3; }
| expr RSHIFT expr { $$ = $1 >> $3; }
| expr '<' expr { $$ = $1 < $3; }
| expr '>' expr { $$ = $1 > $3; }
| expr LE expr { $$ = $1 <= $3; }
| expr GE expr { $$ = $1 >= $3; }
| expr EQ expr { $$ = $1 == $3; }
| expr NE expr { $$ = $1 != $3; }
| expr '&' expr { $$ = $1 & $3; }
| expr '^' expr { $$ = $1 ^ $3; }
| expr '|' expr { $$ = $1 | $3; }
| expr LAND expr { $$ = $1 && $3; }
| expr LOR expr { $$ = $1 || $3; }
| '(' expr ')' { $$ = $2; }
| '-' expr %prec UMINUS { $$ = -$2; }
| '+' expr %prec UPLUS { $$ = $2; }
| '!' expr { $$ = !$2; }
| '~' expr { $$ = ~$2; }
| NUMBER
;
%%
|
