Bug Summary

File:src/usr.bin/tr/str.c
Warning:line 128, column 8
Although the value stored to 'p' is used in the enclosing expression, the value is never actually read from 'p'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name str.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.bin/tr/obj -resource-dir /usr/local/lib/clang/13.0.0 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/tr/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/usr.bin/tr/str.c
1/* $OpenBSD: str.c,v 1.14 2021/11/02 03:09:15 cheloha Exp $ */
2/* $NetBSD: str.c,v 1.7 1995/08/31 22:13:47 jtc Exp $ */
3
4/*-
5 * Copyright (c) 1991, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/types.h>
34
35#include <assert.h>
36#include <errno(*__errno()).h>
37#include <stddef.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <ctype.h>
42#include <err.h>
43
44#include "extern.h"
45
46static int backslash(STR *);
47static int bracket(STR *);
48static int c_class(const void *, const void *);
49static void genclass(STR *);
50static void genequiv(STR *);
51static int genrange(STR *);
52static void genseq(STR *);
53
54int
55next(s)
56 STR *s;
57{
58 int ch;
59
60 switch (s->state) {
61 case EOS:
62 return (0);
63 case INFINITE:
64 return (1);
65 case NORMAL:
66 switch (ch = *s->str) {
67 case '\0':
68 s->state = EOS;
69 return (0);
70 case '\\':
71 s->lastch = backslash(s);
72 break;
73 case '[':
74 if (bracket(s))
75 return (next(s));
76 /* FALLTHROUGH */
77 default:
78 ++s->str;
79 s->lastch = ch;
80 break;
81 }
82
83 /* We can start a range at any time. */
84 if (s->str[0] == '-' && genrange(s))
85 return (next(s));
86 return (1);
87 case RANGE:
88 if (s->cnt-- == 0) {
89 s->state = NORMAL;
90 return (next(s));
91 }
92 ++s->lastch;
93 return (1);
94 case SEQUENCE:
95 if (s->cnt-- == 0) {
96 s->state = NORMAL;
97 return (next(s));
98 }
99 return (1);
100 case SET:
101 if ((s->lastch = s->set[s->cnt++]) == OOBCH((127*2 +1) + 1)) {
102 s->state = NORMAL;
103 return (next(s));
104 }
105 return (1);
106 default:
107 return 0;
108 }
109 /* NOTREACHED */
110}
111
112static int
113bracket(s)
114 STR *s;
115{
116 char *p;
117
118 switch (s->str[1]) {
119 case ':': /* "[:class:]" */
120 if ((p = strstr((char *)s->str + 2, ":]")) == NULL((void*)0))
121 return (0);
122 *p = '\0';
123 s->str += 2;
124 genclass(s);
125 s->str = (unsigned char *)p + 2;
126 return (1);
127 case '=': /* "[=equiv=]" */
128 if ((p = strstr((char *)s->str + 2, "=]")) == NULL((void*)0))
Although the value stored to 'p' is used in the enclosing expression, the value is never actually read from 'p'
129 return (0);
130 s->str += 2;
131 genequiv(s);
132 return (1);
133 default: /* "[\###*n]" or "[#*n]" */
134 if ((p = strpbrk((char *)s->str + 2, "*]")) == NULL((void*)0))
135 return (0);
136 if (p[0] != '*' || strchr(p, ']') == NULL((void*)0))
137 return (0);
138 s->str += 1;
139 genseq(s);
140 return (1);
141 }
142 /* NOTREACHED */
143}
144
145typedef struct {
146 char *name;
147 int (*func)(int);
148 int *set;
149} CLASS;
150
151static CLASS classes[] = {
152 { "alnum", isalnum, },
153 { "alpha", isalpha, },
154 { "blank", isblank, },
155 { "cntrl", iscntrl, },
156 { "digit", isdigit, },
157 { "graph", isgraph, },
158 { "lower", islower, },
159 { "print", isprint, },
160 { "punct", ispunct, },
161 { "space", isspace, },
162 { "upper", isupper, },
163 { "xdigit", isxdigit, },
164};
165
166static void
167genclass(STR *s)
168{
169 CLASS *cp, tmp;
170 size_t len;
171 int i;
172
173 tmp.name = (char *)s->str;
174 if ((cp = (CLASS *)bsearch(&tmp, classes, sizeof(classes) /
175 sizeof(CLASS), sizeof(CLASS), c_class)) == NULL((void*)0))
176 errx(1, "unknown class %s", s->str);
177
178 /*
179 * Generate the set of characters in the class if we haven't
180 * already done so.
181 */
182 if (cp->set == NULL((void*)0)) {
183 cp->set = reallocarray(NULL((void*)0), NCHARS((127*2 +1) + 1) + 1, sizeof(*cp->set));
184 if (cp->set == NULL((void*)0))
185 err(1, NULL((void*)0));
186 len = 0;
187 for (i = 0; i < NCHARS((127*2 +1) + 1); i++) {
188 if (cp->func(i)) {
189 cp->set[len] = i;
190 len++;
191 }
192 }
193 cp->set[len] = OOBCH((127*2 +1) + 1);
194 len++;
195 cp->set = reallocarray(cp->set, len, sizeof(*cp->set));
196 if (cp->set == NULL((void*)0))
197 err(1, NULL((void*)0));
198 }
199
200 s->cnt = 0;
201 s->state = SET;
202 s->set = cp->set;
203}
204
205static int
206c_class(a, b)
207 const void *a, *b;
208{
209 return (strcmp(((CLASS *)a)->name, ((CLASS *)b)->name));
210}
211
212/*
213 * English doesn't have any equivalence classes, so for now
214 * we just syntax check and grab the character.
215 */
216static void
217genequiv(s)
218 STR *s;
219{
220 if (*s->str == '\\') {
221 s->equiv[0] = backslash(s);
222 if (*s->str != '=')
223 errx(1, "misplaced equivalence equals sign");
224 } else {
225 s->equiv[0] = s->str[0];
226 if (s->str[1] != '=')
227 errx(1, "misplaced equivalence equals sign");
228 }
229 s->str += 2;
230 s->cnt = 0;
231 s->state = SET;
232 s->set = s->equiv;
233}
234
235static int
236genrange(s)
237 STR *s;
238{
239 int stopval;
240 unsigned char *savestart;
241
242 savestart = s->str;
243 stopval = *++s->str == '\\' ? backslash(s) : *s->str++;
244 if (stopval < (u_char)s->lastch) {
245 s->str = savestart;
246 return (0);
247 }
248 s->cnt = stopval - s->lastch + 1;
249 s->state = RANGE;
250 --s->lastch;
251 return (1);
252}
253
254static void
255genseq(s)
256 STR *s;
257{
258 char *ep;
259
260 if (s->which == STRING1)
261 errx(1, "sequences only valid in string2");
262
263 if (*s->str == '\\')
264 s->lastch = backslash(s);
265 else
266 s->lastch = *s->str++;
267 if (*s->str != '*')
268 errx(1, "misplaced sequence asterisk");
269
270 switch (*++s->str) {
271 case '\\':
272 s->cnt = backslash(s);
273 break;
274 case ']':
275 s->cnt = 0;
276 ++s->str;
277 break;
278 default:
279 if (isdigit(*s->str)) {
280 s->cnt = strtol((char *)s->str, &ep, 0);
281 if (*ep == ']') {
282 s->str = (unsigned char *)ep + 1;
283 break;
284 }
285 }
286 errx(1, "illegal sequence count");
287 /* NOTREACHED */
288 }
289
290 s->state = s->cnt ? SEQUENCE : INFINITE;
291}
292
293/*
294 * Translate \??? into a character. Up to 3 octal digits, if no digits either
295 * an escape code or a literal character.
296 */
297static int
298backslash(STR *s)
299{
300 size_t i;
301 int ch, val;
302
303 assert(*s->str == '\\')((*s->str == '\\') ? (void)0 : __assert2("/usr/src/usr.bin/tr/str.c"
, 303, __func__, "*s->str == '\\\\'"))
;
304 s->str++;
305
306 /* Empty escapes become plain backslashes. */
307 if (*s->str == '\0') {
308 s->state = EOS;
309 return ('\\');
310 }
311
312 val = 0;
313 for (i = 0; i < 3; i++) {
314 if (s->str[i] < '0' || '7' < s->str[i])
315 break;
316 val = val * 8 + s->str[i] - '0';
317 }
318 if (i > 0) {
319 if (val > UCHAR_MAX(127*2 +1))
320 errx(1, "octal value out of range: %d", val);
321 s->str += i;
322 return (val);
323 }
324
325 ch = *s->str++;
326 switch (ch) {
327 case 'a': /* escape characters */
328 return ('\7');
329 case 'b':
330 return ('\b');
331 case 'f':
332 return ('\f');
333 case 'n':
334 return ('\n');
335 case 'r':
336 return ('\r');
337 case 't':
338 return ('\t');
339 case 'v':
340 return ('\13');
341 default: /* \x" -> x */
342 return (ch);
343 }
344}