xref: /freebsd/lib/libc/gen/fmtcheck.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
1 /*	$FreeBSD$	*/
2 /*	$NetBSD: fmtcheck.c,v 1.2 2000/11/01 01:17:20 briggs Exp $	*/
3 
4 /*-
5  * Copyright (c) 2000 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code was contributed to The NetBSD Foundation by Allen Briggs.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifndef lint
41 static const char rcsid[] =
42   "$FreeBSD$";
43 #endif /* not lint */
44 
45 #include "namespace.h"
46 
47 #include <stdlib.h>
48 #include <stdio.h>
49 #include <string.h>
50 #include <ctype.h>
51 
52 #ifdef __weak_alias
53 __weak_alias(fmtcheck,__fmtcheck)
54 #endif
55 
56 enum __e_fmtcheck_types {
57 	FMTCHECK_START,
58 	FMTCHECK_SHORT,
59 	FMTCHECK_INT,
60 	FMTCHECK_LONG,
61 	FMTCHECK_QUAD,
62 	FMTCHECK_SHORTPOINTER,
63 	FMTCHECK_INTPOINTER,
64 	FMTCHECK_LONGPOINTER,
65 	FMTCHECK_QUADPOINTER,
66 	FMTCHECK_DOUBLE,
67 	FMTCHECK_LONGDOUBLE,
68 	FMTCHECK_STRING,
69 	FMTCHECK_WIDTH,
70 	FMTCHECK_PRECISION,
71 	FMTCHECK_DONE,
72 	FMTCHECK_UNKNOWN
73 };
74 typedef enum __e_fmtcheck_types EFT;
75 
76 #define RETURN(pf,f,r) do { \
77 			*(pf) = (f); \
78 			return r; \
79 		       } /*NOTREACHED*/ /*CONSTCOND*/ while (0)
80 
81 static EFT
82 get_next_format_from_precision(const char **pf)
83 {
84 	int		sh, lg, quad, longdouble;
85 	const char	*f;
86 
87 	sh = lg = quad = longdouble = 0;
88 
89 	f = *pf;
90 	switch (*f) {
91 	case 'h':
92 		f++;
93 		sh = 1;
94 		break;
95 	case 'l':
96 		f++;
97 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
98 		if (*f == 'l') {
99 			f++;
100 			quad = 1;
101 		} else {
102 			lg = 1;
103 		}
104 		break;
105 	case 'q':
106 		f++;
107 		quad = 1;
108 		break;
109 	case 'L':
110 		f++;
111 		longdouble = 1;
112 		break;
113 	default:
114 		break;
115 	}
116 	if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
117 	if (strchr("diouxX", *f)) {
118 		if (longdouble)
119 			RETURN(pf,f,FMTCHECK_UNKNOWN);
120 		if (lg)
121 			RETURN(pf,f,FMTCHECK_LONG);
122 		if (quad)
123 			RETURN(pf,f,FMTCHECK_QUAD);
124 		RETURN(pf,f,FMTCHECK_INT);
125 	}
126 	if (*f == 'n') {
127 		if (longdouble)
128 			RETURN(pf,f,FMTCHECK_UNKNOWN);
129 		if (sh)
130 			RETURN(pf,f,FMTCHECK_SHORTPOINTER);
131 		if (lg)
132 			RETURN(pf,f,FMTCHECK_LONGPOINTER);
133 		if (quad)
134 			RETURN(pf,f,FMTCHECK_QUADPOINTER);
135 		RETURN(pf,f,FMTCHECK_INTPOINTER);
136 	}
137 	if (strchr("DOU", *f)) {
138 		if (sh + lg + quad + longdouble)
139 			RETURN(pf,f,FMTCHECK_UNKNOWN);
140 		RETURN(pf,f,FMTCHECK_LONG);
141 	}
142 	if (strchr("eEfg", *f)) {
143 		if (longdouble)
144 			RETURN(pf,f,FMTCHECK_LONGDOUBLE);
145 		if (sh + lg + quad)
146 			RETURN(pf,f,FMTCHECK_UNKNOWN);
147 		RETURN(pf,f,FMTCHECK_DOUBLE);
148 	}
149 	if (*f == 'c') {
150 		if (sh + lg + quad + longdouble)
151 			RETURN(pf,f,FMTCHECK_UNKNOWN);
152 		RETURN(pf,f,FMTCHECK_INT);
153 	}
154 	if (*f == 's') {
155 		if (sh + lg + quad + longdouble)
156 			RETURN(pf,f,FMTCHECK_UNKNOWN);
157 		RETURN(pf,f,FMTCHECK_STRING);
158 	}
159 	if (*f == 'p') {
160 		if (sh + lg + quad + longdouble)
161 			RETURN(pf,f,FMTCHECK_UNKNOWN);
162 		RETURN(pf,f,FMTCHECK_LONG);
163 	}
164 	RETURN(pf,f,FMTCHECK_UNKNOWN);
165 	/*NOTREACHED*/
166 }
167 
168 static EFT
169 get_next_format_from_width(const char **pf)
170 {
171 	const char	*f;
172 
173 	f = *pf;
174 	if (*f == '.') {
175 		f++;
176 		if (*f == '*') {
177 			RETURN(pf,f,FMTCHECK_PRECISION);
178 		}
179 		/* eat any precision (empty is allowed) */
180 		while (isdigit(*f)) f++;
181 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
182 	}
183 	RETURN(pf,f,get_next_format_from_precision(pf));
184 	/*NOTREACHED*/
185 }
186 
187 static EFT
188 get_next_format(const char **pf, EFT eft)
189 {
190 	int		infmt;
191 	const char	*f;
192 
193 	if (eft == FMTCHECK_WIDTH) {
194 		(*pf)++;
195 		return get_next_format_from_width(pf);
196 	} else if (eft == FMTCHECK_PRECISION) {
197 		(*pf)++;
198 		return get_next_format_from_precision(pf);
199 	}
200 
201 	f = *pf;
202 	infmt = 0;
203 	while (!infmt) {
204 		f = strchr(f, '%');
205 		if (f == NULL)
206 			RETURN(pf,f,FMTCHECK_DONE);
207 		f++;
208 		if (!*f)
209 			RETURN(pf,f,FMTCHECK_UNKNOWN);
210 		if (*f != '%')
211 			infmt = 1;
212 		else
213 			f++;
214 	}
215 
216 	/* Eat any of the flags */
217 	while (*f && (strchr("#0- +", *f)))
218 		f++;
219 
220 	if (*f == '*') {
221 		RETURN(pf,f,FMTCHECK_WIDTH);
222 	}
223 	/* eat any width */
224 	while (isdigit(*f)) f++;
225 	if (!*f) {
226 		RETURN(pf,f,FMTCHECK_UNKNOWN);
227 	}
228 
229 	RETURN(pf,f,get_next_format_from_width(pf));
230 	/*NOTREACHED*/
231 }
232 
233 __const char *
234 fmtcheck(const char *f1, const char *f2)
235 {
236 	const char	*f1p, *f2p;
237 	EFT		f1t, f2t;
238 
239 	if (!f1) return f2;
240 
241 	f1p = f1;
242 	f1t = FMTCHECK_START;
243 	f2p = f2;
244 	f2t = FMTCHECK_START;
245 	while ((f1t = get_next_format(&f1p, f1t)) != FMTCHECK_DONE) {
246 		if (f1t == FMTCHECK_UNKNOWN)
247 			return f2;
248 		f2t = get_next_format(&f2p, f2t);
249 		if (f1t != f2t)
250 			return f2;
251 	}
252 	return f1;
253 }
254