xref: /freebsd/usr.bin/m4/expr.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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 __FBSDID("$FreeBSD$");
19 
20 #include <stdint.h>
21 #include <stdio.h>
22 #include <stddef.h>
23 #include "mdef.h"
24 #include "extern.h"
25 
26 int32_t end_result;
27 static const char *copy_toeval;
28 int yyerror(const char *msg);
29 
30 extern void yy_scan_string(const char *);
31 extern int yyparse(void);
32 
33 int
34 yyerror(const char *msg)
35 {
36 	fprintf(stderr, "m4: %s in expr %s\n", msg, copy_toeval);
37 	return(0);
38 }
39 
40 int
41 expr(const char *toeval)
42 {
43 	copy_toeval = toeval;
44 	yy_scan_string(toeval);
45 	yyparse();
46 	return end_result;
47 }
48