xref: /netbsd-src/lib/libc/gen/fmtcheck.c (revision fd569112f940024a5f16f3ec4b1152dea733e4c8)
1 /*	$NetBSD: fmtcheck.c,v 1.16 2017/12/13 06:43:45 rin Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code was contributed to The NetBSD Foundation by Allen Briggs.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #if defined(LIBC_SCCS) && !defined(lint)
33 __RCSID("$NetBSD: fmtcheck.c,v 1.16 2017/12/13 06:43:45 rin Exp $");
34 #endif
35 
36 #include "namespace.h"
37 
38 #include <stdio.h>
39 #include <string.h>
40 #include <ctype.h>
41 
42 #ifdef __weak_alias
43 __weak_alias(fmtcheck,__fmtcheck)
44 #endif
45 
46 enum __e_fmtcheck_types {
47 	FMTCHECK_START,
48 	FMTCHECK_SHORT,
49 	FMTCHECK_INT,
50 	FMTCHECK_WINTT,
51 	FMTCHECK_LONG,
52 	FMTCHECK_QUAD,
53 	FMTCHECK_INTMAXT,
54 	FMTCHECK_PTRDIFFT,
55 	FMTCHECK_SIZET,
56 	FMTCHECK_POINTER,
57 	FMTCHECK_CHARPOINTER,
58 	FMTCHECK_SHORTPOINTER,
59 	FMTCHECK_INTPOINTER,
60 	FMTCHECK_LONGPOINTER,
61 	FMTCHECK_QUADPOINTER,
62 	FMTCHECK_INTMAXTPOINTER,
63 	FMTCHECK_PTRDIFFTPOINTER,
64 	FMTCHECK_SIZETPOINTER,
65 	FMTCHECK_DOUBLE,
66 	FMTCHECK_LONGDOUBLE,
67 	FMTCHECK_STRING,
68 	FMTCHECK_WSTRING,
69 	FMTCHECK_WIDTH,
70 	FMTCHECK_PRECISION,
71 	FMTCHECK_DONE,
72 	FMTCHECK_UNKNOWN
73 };
74 typedef enum __e_fmtcheck_types EFT;
75 
76 enum e_modifier {
77 	MOD_NONE,
78 	MOD_CHAR,
79 	MOD_SHORT,
80 	MOD_LONG,
81 	MOD_QUAD,
82 	MOD_INTMAXT,
83 	MOD_LONGDOUBLE,
84 	MOD_PTRDIFFT,
85 	MOD_SIZET,
86 };
87 
88 #define RETURN(pf,f,r) do { \
89 			*(pf) = (f); \
90 			return r; \
91 		       } /*NOTREACHED*/ /*CONSTCOND*/ while (0)
92 
93 static EFT
get_next_format_from_precision(const char ** pf)94 get_next_format_from_precision(const char **pf)
95 {
96 	enum e_modifier	modifier;
97 	const char	*f;
98 
99 	f = *pf;
100 	switch (*f) {
101 	case 'h':
102 		f++;
103 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
104 		if (*f == 'h') {
105 			f++;
106 			modifier = MOD_CHAR;
107 		} else {
108 			modifier = MOD_SHORT;
109 		}
110 		break;
111 	case 'j':
112 		f++;
113 		modifier = MOD_INTMAXT;
114 		break;
115 	case 'l':
116 		f++;
117 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
118 		if (*f == 'l') {
119 			f++;
120 			modifier = MOD_QUAD;
121 		} else {
122 			modifier = MOD_LONG;
123 		}
124 		break;
125 	case 'q':
126 		f++;
127 		modifier = MOD_QUAD;
128 		break;
129 	case 't':
130 		f++;
131 		modifier = MOD_PTRDIFFT;
132 		break;
133 	case 'z':
134 		f++;
135 		modifier = MOD_SIZET;
136 		break;
137 	case 'L':
138 		f++;
139 		modifier = MOD_LONGDOUBLE;
140 		break;
141 #ifdef WIN32
142 	case 'I':
143 		f++;
144 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
145 		if (*f == '3' && f[1] == '2') {
146 			f += 2;
147 			modifier = MOD_NONE;
148 		} else if (*f == '6' && f[1] == '4') {
149 			f += 2;
150 			modifier = MOD_QUAD;
151 		}
152 		else {
153 #ifdef _WIN64
154 			modifier = MOD_QUAD;
155 #else
156 			modifier = MOD_NONE;
157 #endif
158 		}
159 		break;
160 #endif
161 	default:
162 		modifier = MOD_NONE;
163 		break;
164 	}
165 	if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
166 	if (strchr("diouxX", *f)) {
167 		switch (modifier) {
168 		case MOD_LONG:
169 			RETURN(pf,f,FMTCHECK_LONG);
170 		case MOD_QUAD:
171 			RETURN(pf,f,FMTCHECK_QUAD);
172 		case MOD_INTMAXT:
173 			RETURN(pf,f,FMTCHECK_INTMAXT);
174 		case MOD_PTRDIFFT:
175 			RETURN(pf,f,FMTCHECK_PTRDIFFT);
176 		case MOD_SIZET:
177 			RETURN(pf,f,FMTCHECK_SIZET);
178 		case MOD_CHAR:
179 		case MOD_SHORT:
180 		case MOD_NONE:
181 			RETURN(pf,f,FMTCHECK_INT);
182 		default:
183 			RETURN(pf,f,FMTCHECK_UNKNOWN);
184 		}
185 	}
186 	if (*f == 'n') {
187 		switch (modifier) {
188 		case MOD_CHAR:
189 			RETURN(pf,f,FMTCHECK_CHARPOINTER);
190 		case MOD_SHORT:
191 			RETURN(pf,f,FMTCHECK_SHORTPOINTER);
192 		case MOD_LONG:
193 			RETURN(pf,f,FMTCHECK_LONGPOINTER);
194 		case MOD_QUAD:
195 			RETURN(pf,f,FMTCHECK_QUADPOINTER);
196 		case MOD_INTMAXT:
197 			RETURN(pf,f,FMTCHECK_INTMAXTPOINTER);
198 		case MOD_PTRDIFFT:
199 			RETURN(pf,f,FMTCHECK_PTRDIFFTPOINTER);
200 		case MOD_SIZET:
201 			RETURN(pf,f,FMTCHECK_SIZETPOINTER);
202 		case MOD_NONE:
203 			RETURN(pf,f,FMTCHECK_INTPOINTER);
204 		default:
205 			RETURN(pf,f,FMTCHECK_UNKNOWN);
206 		}
207 	}
208 	if (strchr("DOU", *f)) {
209 		if (modifier != MOD_NONE)
210 			RETURN(pf,f,FMTCHECK_UNKNOWN);
211 		RETURN(pf,f,FMTCHECK_LONG);
212 	}
213 	if (strchr("aAeEfFgG", *f)) {
214 		switch (modifier) {
215 		case MOD_LONGDOUBLE:
216 			RETURN(pf,f,FMTCHECK_LONGDOUBLE);
217 		case MOD_LONG:
218 		case MOD_NONE:
219 			RETURN(pf,f,FMTCHECK_DOUBLE);
220 		default:
221 			RETURN(pf,f,FMTCHECK_UNKNOWN);
222 		}
223 	}
224 	if (*f == 'c') {
225 		switch (modifier) {
226 		case MOD_LONG:
227 			RETURN(pf,f,FMTCHECK_WINTT);
228 		case MOD_NONE:
229 			RETURN(pf,f,FMTCHECK_INT);
230 		default:
231 			RETURN(pf,f,FMTCHECK_UNKNOWN);
232 		}
233 	}
234 	if (*f == 'C') {
235 		if (modifier != MOD_NONE)
236 			RETURN(pf,f,FMTCHECK_UNKNOWN);
237 		RETURN(pf,f,FMTCHECK_WINTT);
238 	}
239 	if (*f == 's') {
240 		switch (modifier) {
241 		case MOD_LONG:
242 			RETURN(pf,f,FMTCHECK_WSTRING);
243 		case MOD_NONE:
244 			RETURN(pf,f,FMTCHECK_STRING);
245 		default:
246 			RETURN(pf,f,FMTCHECK_UNKNOWN);
247 		}
248 	}
249 	if (*f == 'S') {
250 		if (modifier != MOD_NONE)
251 			RETURN(pf,f,FMTCHECK_UNKNOWN);
252 		RETURN(pf,f,FMTCHECK_WSTRING);
253 	}
254 	if (*f == 'p') {
255 		if (modifier != MOD_NONE)
256 			RETURN(pf,f,FMTCHECK_UNKNOWN);
257 		RETURN(pf,f,FMTCHECK_POINTER);
258 	}
259 	RETURN(pf,f,FMTCHECK_UNKNOWN);
260 	/*NOTREACHED*/
261 }
262 
263 static EFT
get_next_format_from_width(const char ** pf)264 get_next_format_from_width(const char **pf)
265 {
266 	const char	*f;
267 
268 	f = *pf;
269 	if (*f == '.') {
270 		f++;
271 		if (*f == '*') {
272 			RETURN(pf,f,FMTCHECK_PRECISION);
273 		}
274 		/* eat any precision (empty is allowed) */
275 		while (isdigit((unsigned char)*f)) f++;
276 		if (!*f) RETURN(pf,f,FMTCHECK_UNKNOWN);
277 	}
278 	RETURN(pf,f,get_next_format_from_precision(pf));
279 	/*NOTREACHED*/
280 }
281 
282 static EFT
get_next_format(const char ** pf,EFT eft)283 get_next_format(const char **pf, EFT eft)
284 {
285 	int		infmt;
286 	const char	*f;
287 
288 	if (eft == FMTCHECK_WIDTH) {
289 		(*pf)++;
290 		return get_next_format_from_width(pf);
291 	} else if (eft == FMTCHECK_PRECISION) {
292 		(*pf)++;
293 		return get_next_format_from_precision(pf);
294 	}
295 
296 	f = *pf;
297 	infmt = 0;
298 	while (!infmt) {
299 		f = strchr(f, '%');
300 		if (f == NULL)
301 			RETURN(pf,f,FMTCHECK_DONE);
302 		f++;
303 		if (!*f)
304 			RETURN(pf,f,FMTCHECK_UNKNOWN);
305 		if (*f != '%')
306 			infmt = 1;
307 		else
308 			f++;
309 	}
310 
311 	/* Eat any of the flags */
312 	while (*f && (strchr("#'0- +", *f)))
313 		f++;
314 
315 	if (*f == '*') {
316 		RETURN(pf,f,FMTCHECK_WIDTH);
317 	}
318 	/* eat any width */
319 	while (isdigit((unsigned char)*f)) f++;
320 	if (!*f) {
321 		RETURN(pf,f,FMTCHECK_UNKNOWN);
322 	}
323 
324 	RETURN(pf,f,get_next_format_from_width(pf));
325 	/*NOTREACHED*/
326 }
327 
328 const char *
fmtcheck(const char * f1,const char * f2)329 fmtcheck(const char *f1, const char *f2)
330 {
331 	const char	*f1p, *f2p;
332 	EFT		f1t, f2t;
333 
334 	if (!f1) return f2;
335 
336 	f1p = f1;
337 	f1t = FMTCHECK_START;
338 	f2p = f2;
339 	f2t = FMTCHECK_START;
340 	while ((f1t = get_next_format(&f1p, f1t)) != FMTCHECK_DONE) {
341 		if (f1t == FMTCHECK_UNKNOWN)
342 			return f2;
343 		f2t = get_next_format(&f2p, f2t);
344 		if (f1t != f2t)
345 			return f2;
346 	}
347 	return f1;
348 }
349