xref: /freebsd/usr.bin/m4/expr.c (revision 2e3507c25e42292b45a5482e116d278f5515d04d)
1 /* $OpenBSD: expr.c,v 1.18 2010/09/07 19:58:09 marco Exp $ */
2 /*
3  * Copyright (c) 2004 Marc Espie <espie@cvs.openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 #include <sys/cdefs.h>
18 #include <stdint.h>
19 #include <stdio.h>
20 #include <stddef.h>
21 #include "mdef.h"
22 #include "extern.h"
23 
24 int32_t end_result;
25 static const char *copy_toeval;
26 int yyerror(const char *msg);
27 
28 extern void yy_scan_string(const char *);
29 extern int yyparse(void);
30 
31 int
32 yyerror(const char *msg)
33 {
34 	fprintf(stderr, "m4: %s in expr %s\n", msg, copy_toeval);
35 	return(0);
36 }
37 
38 int
39 expr(const char *toeval)
40 {
41 	copy_toeval = toeval;
42 	yy_scan_string(toeval);
43 	yyparse();
44 	return end_result;
45 }
46