Bug Summary

File:src/gnu/lib/libiberty/src/make-relative-prefix.c
Warning:line 186, column 26
The left operand of '==' is a garbage value due to array index out of bounds

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 make-relative-prefix.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 -fhalf-no-semantic-interposition -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/gnu/lib/libiberty/obj -resource-dir /usr/local/lib/clang/13.0.0 -D HAVE_CONFIG_H -I /usr/src/gnu/lib/libiberty/src -I /usr/src/gnu/lib/libiberty/include -I /usr/src/gnu/lib/libiberty/obj -D PIC -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/gnu/lib/libiberty/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/gnu/lib/libiberty/src/make-relative-prefix.c
1/* Relative (relocatable) prefix support.
2 Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
4
5This file is part of libiberty.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING. If not, write to the Free
19Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
2002110-1301, USA. */
21
22/*
23
24@deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, const char *@var{bin_prefix}, const char *@var{prefix})
25
26Given three paths @var{progname}, @var{bin_prefix}, @var{prefix},
27return the path that is in the same position relative to
28@var{progname}'s directory as @var{prefix} is relative to
29@var{bin_prefix}. That is, a string starting with the directory
30portion of @var{progname}, followed by a relative pathname of the
31difference between @var{bin_prefix} and @var{prefix}.
32
33If @var{progname} does not contain any directory separators,
34@code{make_relative_prefix} will search @env{PATH} to find a program
35named @var{progname}. Also, if @var{progname} is a symbolic link,
36the symbolic link will be resolved.
37
38For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta},
39@var{prefix} is @code{/alpha/beta/gamma/omega/}, and @var{progname} is
40@code{/red/green/blue/gcc}, then this function will return
41@code{/red/green/blue/../../omega/}.
42
43The return value is normally allocated via @code{malloc}. If no
44relative prefix can be found, return @code{NULL}.
45
46@end deftypefn
47
48*/
49
50#ifdef HAVE_CONFIG_H1
51#include "config.h"
52#endif
53
54#ifdef HAVE_STDLIB_H1
55#include <stdlib.h>
56#endif
57#ifdef HAVE_UNISTD_H1
58#include <unistd.h>
59#endif
60
61#include <string.h>
62
63#include "ansidecl.h"
64#include "libiberty.h"
65
66#ifndef R_OK0x04
67#define R_OK0x04 4
68#define W_OK0x02 2
69#define X_OK0x01 1
70#endif
71
72#ifndef DIR_SEPARATOR'/'
73# define DIR_SEPARATOR'/' '/'
74#endif
75
76#if defined (_WIN32) || defined (__MSDOS__) \
77 || defined (__DJGPP__) || defined (__OS2__)
78# define HAVE_DOS_BASED_FILE_SYSTEM
79# define HAVE_HOST_EXECUTABLE_SUFFIX
80# define HOST_EXECUTABLE_SUFFIX ".exe"
81# ifndef DIR_SEPARATOR_2
82# define DIR_SEPARATOR_2 '\\'
83# endif
84# define PATH_SEPARATOR':' ';'
85#else
86# define PATH_SEPARATOR':' ':'
87#endif
88
89#ifndef DIR_SEPARATOR_2
90# define IS_DIR_SEPARATOR(ch)((ch) == '/') ((ch) == DIR_SEPARATOR'/')
91#else
92# define IS_DIR_SEPARATOR(ch)((ch) == '/') \
93 (((ch) == DIR_SEPARATOR'/') || ((ch) == DIR_SEPARATOR_2))
94#endif
95
96#define DIR_UP".." ".."
97
98static char *save_string (const char *, int);
99static char **split_directories (const char *, int *);
100static void free_split_directories (char **);
101
102static char *
103save_string (const char *s, int len)
104{
105 char *result = (char *) malloc (len + 1);
106
107 memcpy (result, s, len);
108 result[len] = 0;
109 return result;
110}
111
112/* Split a filename into component directories. */
113
114static char **
115split_directories (const char *name, int *ptr_num_dirs)
116{
117 int num_dirs = 0;
118 char **dirs;
119 const char *p, *q;
120 int ch;
121
122 /* Count the number of directories. Special case MSDOS disk names as part
123 of the initial directory. */
124 p = name;
125#ifdef HAVE_DOS_BASED_FILE_SYSTEM
126 if (name[1] == ':' && IS_DIR_SEPARATOR (name[2])((name[2]) == '/'))
127 {
128 p += 3;
129 num_dirs++;
130 }
131#endif /* HAVE_DOS_BASED_FILE_SYSTEM */
132
133 while ((ch = *p++) != '\0')
10
←
Assuming the condition is false
→
11
←
Loop condition is false. Execution continues on line 143
→
134 {
135 if (IS_DIR_SEPARATOR (ch)((ch) == '/'))
136 {
137 num_dirs++;
138 while (IS_DIR_SEPARATOR (*p)((*p) == '/'))
139 p++;
140 }
141 }
142
143 dirs = (char **) malloc (sizeof (char *) * (num_dirs + 2));
12
←
Storing uninitialized value
→
144 if (dirs == NULL((void*)0))
13
←
Assuming 'dirs' is not equal to NULL
→
14
←
Taking false branch
→
145 return NULL((void*)0);
146
147 /* Now copy the directory parts. */
148 num_dirs = 0;
149 p = name;
150#ifdef HAVE_DOS_BASED_FILE_SYSTEM
151 if (name[1] == ':' && IS_DIR_SEPARATOR (name[2])((name[2]) == '/'))
152 {
153 dirs[num_dirs++] = save_string (p, 3);
154 if (dirs[num_dirs - 1] == NULL((void*)0))
155 {
156 free (dirs);
157 return NULL((void*)0);
158 }
159 p += 3;
160 }
161#endif /* HAVE_DOS_BASED_FILE_SYSTEM */
162
163 q = p;
164 while ((ch = *p++) != '\0')
15
←
Loop condition is false. Execution continues on line 182
→
165 {
166 if (IS_DIR_SEPARATOR (ch)((ch) == '/'))
167 {
168 while (IS_DIR_SEPARATOR (*p)((*p) == '/'))
169 p++;
170
171 dirs[num_dirs++] = save_string (q, p - q);
172 if (dirs[num_dirs - 1] == NULL((void*)0))
173 {
174 dirs[num_dirs] = NULL((void*)0);
175 free_split_directories (dirs);
176 return NULL((void*)0);
177 }
178 q = p;
179 }
180 }
181
182 if (p - 1 - q > 0)
16
←
Assuming the condition is false
→
17
←
Taking false branch
→
183 dirs[num_dirs++] = save_string (q, p - 1 - q);
184 dirs[num_dirs] = NULL((void*)0);
185
186 if (dirs[num_dirs - 1] == NULL((void*)0))
18
←
The left operand of '==' is a garbage value due to array index out of bounds
187 {
188 free_split_directories (dirs);
189 return NULL((void*)0);
190 }
191
192 if (ptr_num_dirs)
193 *ptr_num_dirs = num_dirs;
194 return dirs;
195}
196
197/* Release storage held by split directories. */
198
199static void
200free_split_directories (char **dirs)
201{
202 int i = 0;
203
204 while (dirs[i] != NULL((void*)0))
205 free (dirs[i++]);
206
207 free ((char *) dirs);
208}
209
210/* Given three strings PROGNAME, BIN_PREFIX, PREFIX, return a string that gets
211 to PREFIX starting with the directory portion of PROGNAME and a relative
212 pathname of the difference between BIN_PREFIX and PREFIX.
213
214 For example, if BIN_PREFIX is /alpha/beta/gamma/gcc/delta, PREFIX is
215 /alpha/beta/gamma/omega/, and PROGNAME is /red/green/blue/gcc, then this
216 function will return /red/green/blue/../../omega/.
217
218 If no relative prefix can be found, return NULL. */
219
220char *
221make_relative_prefix (const char *progname,
222 const char *bin_prefix, const char *prefix)
223{
224 char **prog_dirs, **bin_dirs, **prefix_dirs;
225 int prog_num, bin_num, prefix_num;
226 int i, n, common;
227 int needed_len;
228 char *ret, *ptr, *full_progname = NULL((void*)0);
229
230 if (progname == NULL((void*)0) || bin_prefix == NULL((void*)0) || prefix == NULL((void*)0))
1
Assuming 'progname' is not equal to NULL
→
2
←
Assuming 'bin_prefix' is not equal to NULL
→
3
←
Assuming 'prefix' is not equal to NULL
→
4
←
Taking false branch
→
231 return NULL((void*)0);
232
233 /* If there is no full pathname, try to find the program by checking in each
234 of the directories specified in the PATH environment variable. */
235 if (lbasename (progname) == progname)
5
←
Assuming the condition is false
→
6
←
Taking false branch
→
236 {
237 char *temp;
238
239 temp = getenv ("PATH");
240 if (temp)
241 {
242 char *startp, *endp, *nstore;
243 size_t prefixlen = strlen (temp) + 1;
244 if (prefixlen < 2)
245 prefixlen = 2;
246
247 nstore = (char *) alloca (prefixlen + strlen (progname) + 1)__builtin_alloca(prefixlen + strlen (progname) + 1);
248
249 startp = endp = temp;
250 while (1)
251 {
252 if (*endp == PATH_SEPARATOR':' || *endp == 0)
253 {
254 if (endp == startp)
255 {
256 nstore[0] = '.';
257 nstore[1] = DIR_SEPARATOR'/';
258 nstore[2] = '\0';
259 }
260 else
261 {
262 strncpy (nstore, startp, endp - startp);
263 if (! IS_DIR_SEPARATOR (endp[-1])((endp[-1]) == '/'))
264 {
265 nstore[endp - startp] = DIR_SEPARATOR'/';
266 nstore[endp - startp + 1] = 0;
267 }
268 else
269 nstore[endp - startp] = 0;
270 }
271 strcat (nstore, progname);
272 if (! access (nstore, X_OK0x01)
273#ifdef HAVE_HOST_EXECUTABLE_SUFFIX
274 || ! access (strcat (nstore, HOST_EXECUTABLE_SUFFIX), X_OK0x01)
275#endif
276 )
277 {
278 progname = nstore;
279 break;
280 }
281
282 if (*endp == 0)
283 break;
284 endp = startp = endp + 1;
285 }
286 else
287 endp++;
288 }
289 }
290 }
291
292 full_progname = lrealpath (progname);
293 if (full_progname == NULL((void*)0))
7
←
Assuming 'full_progname' is not equal to NULL
→
8
←
Taking false branch
→
294 return NULL((void*)0);
295
296 prog_dirs = split_directories (full_progname, &prog_num);
9
←
Calling 'split_directories'
→
297 bin_dirs = split_directories (bin_prefix, &bin_num);
298 free (full_progname);
299 if (bin_dirs == NULL((void*)0) || prog_dirs == NULL((void*)0))
300 return NULL((void*)0);
301
302 /* Remove the program name from comparison of directory names. */
303 prog_num--;
304
305 /* If we are still installed in the standard location, we don't need to
306 specify relative directories. Also, if argv[0] still doesn't contain
307 any directory specifiers after the search above, then there is not much
308 we can do. */
309 if (prog_num == bin_num)
310 {
311 for (i = 0; i < bin_num; i++)
312 {
313 if (strcmp (prog_dirs[i], bin_dirs[i]) != 0)
314 break;
315 }
316
317 if (prog_num <= 0 || i == bin_num)
318 {
319 free_split_directories (prog_dirs);
320 free_split_directories (bin_dirs);
321 prog_dirs = bin_dirs = (char **) 0;
322 return NULL((void*)0);
323 }
324 }
325
326 prefix_dirs = split_directories (prefix, &prefix_num);
327 if (prefix_dirs == NULL((void*)0))
328 {
329 free_split_directories (prog_dirs);
330 free_split_directories (bin_dirs);
331 return NULL((void*)0);
332 }
333
334 /* Find how many directories are in common between bin_prefix & prefix. */
335 n = (prefix_num < bin_num) ? prefix_num : bin_num;
336 for (common = 0; common < n; common++)
337 {
338 if (strcmp (bin_dirs[common], prefix_dirs[common]) != 0)
339 break;
340 }
341
342 /* If there are no common directories, there can be no relative prefix. */
343 if (common == 0)
344 {
345 free_split_directories (prog_dirs);
346 free_split_directories (bin_dirs);
347 free_split_directories (prefix_dirs);
348 return NULL((void*)0);
349 }
350
351 /* Two passes: first figure out the size of the result string, and
352 then construct it. */
353 needed_len = 0;
354 for (i = 0; i < prog_num; i++)
355 needed_len += strlen (prog_dirs[i]);
356 needed_len += sizeof (DIR_UP"..") * (bin_num - common);
357 for (i = common; i < prefix_num; i++)
358 needed_len += strlen (prefix_dirs[i]);
359 needed_len += 1; /* Trailing NUL. */
360
361 ret = (char *) malloc (needed_len);
362 if (ret == NULL((void*)0))
363 return NULL((void*)0);
364
365 /* Build up the pathnames in argv[0]. */
366 *ret = '\0';
367 for (i = 0; i < prog_num; i++)
368 strcat (ret, prog_dirs[i]);
369
370 /* Now build up the ..'s. */
371 ptr = ret + strlen(ret);
372 for (i = common; i < bin_num; i++)
373 {
374 strcpy (ptr, DIR_UP"..");
375 ptr += sizeof (DIR_UP"..") - 1;
376 *(ptr++) = DIR_SEPARATOR'/';
377 }
378 *ptr = '\0';
379
380 /* Put in directories to move over to prefix. */
381 for (i = common; i < prefix_num; i++)
382 strcat (ret, prefix_dirs[i]);
383
384 free_split_directories (prog_dirs);
385 free_split_directories (bin_dirs);
386 free_split_directories (prefix_dirs);
387
388 return ret;
389}