0b62c3a7c7
user-defined numeric symbols. Whenever possible, use `expr' instead of `NUM' to get full express ion power :-)
80 lines
1.3 KiB
Text
80 lines
1.3 KiB
Text
/*
|
|
* BIRD -- Configuration Parser Top
|
|
*
|
|
* (c) 1998 Martin Mares <mj@ucw.cz>
|
|
*
|
|
* Can be freely distributed and used under the terms of the GNU GPL.
|
|
*/
|
|
|
|
CF_HDR
|
|
|
|
#include "nest/bird.h"
|
|
#include "conf/conf.h"
|
|
#include "lib/resource.h"
|
|
#include "lib/socket.h"
|
|
#include "lib/timer.h"
|
|
#include "nest/protocol.h"
|
|
|
|
CF_DECLS
|
|
|
|
%union {
|
|
int i;
|
|
ip_addr a;
|
|
struct symbol *s;
|
|
char *t;
|
|
}
|
|
|
|
%token END
|
|
%token <i> NUM
|
|
%token <a> IPA
|
|
%token <s> SYM
|
|
%token <t> TEXT
|
|
|
|
%type <i> expr
|
|
|
|
%left '+' '-'
|
|
%left '*' '/' '%'
|
|
|
|
CF_KEYWORDS(DEFINE)
|
|
|
|
CF_GRAMMAR
|
|
|
|
/* Basic config file structure */
|
|
|
|
config: conf_entries END {
|
|
return 0;
|
|
}
|
|
;
|
|
|
|
conf_entries:
|
|
/* EMPTY */
|
|
| conf_entries conf ';'
|
|
;
|
|
|
|
CF_ADDTO(conf, /* EMPTY */)
|
|
|
|
/* Expressions */
|
|
|
|
expr:
|
|
NUM
|
|
| expr '+' expr { $$ = $1 + $3; }
|
|
| expr '-' expr { $$ = $1 - $3; }
|
|
| expr '*' expr { $$ = $1 * $3; }
|
|
| expr '/' expr { if ($3) $$ = $1 / $3; else cf_error("Division by zero"); }
|
|
| expr '%' expr { if ($3) $$ = $1 % $3; else cf_error("Division by zero"); }
|
|
| '(' expr ')' { $$ = $2; }
|
|
| SYM { if ($1->class != SYM_NUMBER) cf_error("Number expected"); else $$ = $1->aux; }
|
|
;
|
|
|
|
CF_ADDTO(conf, definition)
|
|
definition:
|
|
DEFINE SYM '=' expr {
|
|
if ($2->class != SYM_VOID) cf_error("Symbol already defined");
|
|
$2->class = SYM_NUMBER;
|
|
$2->aux = $4;
|
|
}
|
|
;
|
|
|
|
CF_CODE
|
|
|
|
CF_END
|