xref: /freebsd/lib/libc/gen/fmtcheck.c (revision ae83180158c4c937f170e31eff311b18c0286a93)
1 /*-
2  * Copyright (c) 2000 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code was contributed to The NetBSD Foundation by Allen Briggs.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by the NetBSD
18  *        Foundation, Inc. and its contributors.
19  * 4. Neither the name of The NetBSD Foundation nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /*	$NetBSD: fmtcheck.c,v 1.2 2000/11/01 01:17:20 briggs Exp $	*/
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <stdio.h>
41 #include <string.h>
42 #include <ctype.h>
43 
44 __weak_reference(__fmtcheck, fmtcheck);
45 
46 enum __e_fmtcheck_types {
47 	FMTCHECK_START,
48 	FMTCHECK_SHORT,
49 	FMTCHECK_INT,
50 	FMTCHECK_LONG,
51 	FMTCHECK_QUAD,
52 	FMTCHECK_SHORTPOINTER,
53 	FMTCHECK_INTPOINTER,
54 	FMTCHECK_LONGPOINTER,
55 	FMTCHECK_QUADPOINTER,
56 	FMTCHECK_DOUBLE,
57 	FMTCHECK_LONGDOUBLE,
58 	FMTCHECK_STRING,
59 	FMTCHECK_WIDTH,
60 	FMTCHECK_PRECISION,
61 	FMTCHECK_DONE,
62 	FMTCHECK_UNKNOWN
63 };
64 typedef enum __e_fmtcheck_types EFT;
65 
66 #define RETURN(pf,f,r) do { \
67 			*(pf) = (f); \
68 			return r; \
69 		       } /*NOTREACHED*/ /*CONSTCOND*/ while (0)
70 
71 static EFT
72 get_next_format_from_precision(const char **pf)
73 {
74 	int		sh, lg, quad, longdouble;
75 	const char	*f;
76 
77 	sh = lg = quad = longdouble = 0;
78 
79 	f = *pf;
80 	switch (*f) {
81 	case 'h':
82 		f++;
83 		sh = 1;
84 		break;
85 	case 'l':
86 		f++;
87 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
88 		if (*f == 'l') {
89 			f++;
90 			quad = 1;
91 		} else {
92 			lg = 1;
93 		}
94 		break;
95 	case 'q':
96 		f++;
97 		quad = 1;
98 		break;
99 	case 'L':
100 		f++;
101 		longdouble = 1;
102 		break;
103 	default:
104 		break;
105 	}
106 	if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
107 	if (strchr("diouxX", *f)) {
108 		if (longdouble)
109 			RETURN(pf,f,FMTCHECK_UNKNOWN);
110 		if (lg)
111 			RETURN(pf,f,FMTCHECK_LONG);
112 		if (quad)
113 			RETURN(pf,f,FMTCHECK_QUAD);
114 		RETURN(pf,f,FMTCHECK_INT);
115 	}
116 	if (*f == 'n') {
117 		if (longdouble)
118 			RETURN(pf,f,FMTCHECK_UNKNOWN);
119 		if (sh)
120 			RETURN(pf,f,FMTCHECK_SHORTPOINTER);
121 		if (lg)
122 			RETURN(pf,f,FMTCHECK_LONGPOINTER);
123 		if (quad)
124 			RETURN(pf,f,FMTCHECK_QUADPOINTER);
125 		RETURN(pf,f,FMTCHECK_INTPOINTER);
126 	}
127 	if (strchr("DOU", *f)) {
128 		if (sh + lg + quad + longdouble)
129 			RETURN(pf,f,FMTCHECK_UNKNOWN);
130 		RETURN(pf,f,FMTCHECK_LONG);
131 	}
132 	if (strchr("eEfg", *f)) {
133 		if (longdouble)
134 			RETURN(pf,f,FMTCHECK_LONGDOUBLE);
135 		if (sh + lg + quad)
136 			RETURN(pf,f,FMTCHECK_UNKNOWN);
137 		RETURN(pf,f,FMTCHECK_DOUBLE);
138 	}
139 	if (*f == 'c') {
140 		if (sh + lg + quad + longdouble)
141 			RETURN(pf,f,FMTCHECK_UNKNOWN);
142 		RETURN(pf,f,FMTCHECK_INT);
143 	}
144 	if (*f == 's') {
145 		if (sh + lg + quad + longdouble)
146 			RETURN(pf,f,FMTCHECK_UNKNOWN);
147 		RETURN(pf,f,FMTCHECK_STRING);
148 	}
149 	if (*f == 'p') {
150 		if (sh + lg + quad + longdouble)
151 			RETURN(pf,f,FMTCHECK_UNKNOWN);
152 		RETURN(pf,f,FMTCHECK_LONG);
153 	}
154 	RETURN(pf,f,FMTCHECK_UNKNOWN);
155 	/*NOTREACHED*/
156 }
157 
158 static EFT
159 get_next_format_from_width(const char **pf)
160 {
161 	const char	*f;
162 
163 	f = *pf;
164 	if (*f == '.') {
165 		f++;
166 		if (*f == '*') {
167 			RETURN(pf,f,FMTCHECK_PRECISION);
168 		}
169 		/* eat any precision (empty is allowed) */
170 		while (isdigit(*f)) f++;
171 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
172 	}
173 	RETURN(pf,f,get_next_format_from_precision(pf));
174 	/*NOTREACHED*/
175 }
176 
177 static EFT
178 get_next_format(const char **pf, EFT eft)
179 {
180 	int		infmt;
181 	const char	*f;
182 
183 	if (eft == FMTCHECK_WIDTH) {
184 		(*pf)++;
185 		return get_next_format_from_width(pf);
186 	} else if (eft == FMTCHECK_PRECISION) {
187 		(*pf)++;
188 		return get_next_format_from_precision(pf);
189 	}
190 
191 	f = *pf;
192 	infmt = 0;
193 	while (!infmt) {
194 		f = strchr(f, '%');
195 		if (f == NULL)
196 			RETURN(pf,f,FMTCHECK_DONE);
197 		f++;
198 		if (!*f)
199 			RETURN(pf,f,FMTCHECK_UNKNOWN);
200 		if (*f != '%')
201 			infmt = 1;
202 		else
203 			f++;
204 	}
205 
206 	/* Eat any of the flags */
207 	while (*f && (strchr("#0- +", *f)))
208 		f++;
209 
210 	if (*f == '*') {
211 		RETURN(pf,f,FMTCHECK_WIDTH);
212 	}
213 	/* eat any width */
214 	while (isdigit(*f)) f++;
215 	if (!*f) {
216 		RETURN(pf,f,FMTCHECK_UNKNOWN);
217 	}
218 
219 	RETURN(pf,f,get_next_format_from_width(pf));
220 	/*NOTREACHED*/
221 }
222 
223 __const char *
224 __fmtcheck(const char *f1, const char *f2)
225 {
226 	const char	*f1p, *f2p;
227 	EFT		f1t, f2t;
228 
229 	if (!f1) return f2;
230 
231 	f1p = f1;
232 	f1t = FMTCHECK_START;
233 	f2p = f2;
234 	f2t = FMTCHECK_START;
235 	while ((f1t = get_next_format(&f1p, f1t)) != FMTCHECK_DONE) {
236 		if (f1t == FMTCHECK_UNKNOWN)
237 			return f2;
238 		f2t = get_next_format(&f2p, f2t);
239 		if (f1t != f2t)
240 			return f2;
241 	}
242 	return f1;
243 }
244