xref: /openbsd/usr.bin/m4/expr.c (revision 09467b48)
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 <stdint.h>
18 #include <stdio.h>
19 #include <stddef.h>
20 #include "mdef.h"
21 #include "extern.h"
22 
23 int32_t end_result;
24 const char *copy_toeval;
25 
26 extern void yy_scan_string(const char *);
27 extern int yyparse(void);
28 
29 int
30 yyerror(const char *msg)
31 {
32 	fprintf(stderr, "m4: %s in expr %s\n", msg, copy_toeval);
33 	return(0);
34 }
35 
36 int
37 expr(const char *toeval)
38 {
39 	copy_toeval = toeval;
40 	yy_scan_string(toeval);
41 	yyparse();
42 	return end_result;
43 }
44