OpenCoverage

utimecmp.c

Absolute File Name:

/home/opencoverage/opencoverage/guest-scripts/coreutils/src/gnulib/lib/utimecmp.c

Source code

Switch to Preprocessed file

Line Source Count

1 /* utimecmp.c -- compare file timestamps -

2 -

4 -

5 This program is free software: you can redistribute it and/or modify -

6 it under the terms of the GNU General Public License as published by -

7 the Free Software Foundation; either version 3 of the License, or -

8 (at your option) any later version. -

9 -

10 This program is distributed in the hope that it will be useful, -

11 but WITHOUT ANY WARRANTY; without even the implied warranty of -

12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -

13 GNU General Public License for more details. -

14 -

15 You should have received a copy of the GNU General Public License -

16 along with this program. If not, see <https://www.gnu.org/licenses/>. */ -

17 -

18 /* Written by Paul Eggert. */ -

19 -

20 #include <config.h> -

21 -

22 #include "utimecmp.h" -

23 -

24 #include <fcntl.h> -

25 #include <limits.h> -

26 #include <stdbool.h> -

27 #include <stdint.h> -

28 #include <stdlib.h> -

29 #include <sys/stat.h> -

30 #include <time.h> -

31 #include <unistd.h> -

32 -

33 #include "dirname.h" -

34 #include "hash.h" -

35 #include "intprops.h" -

36 #include "stat-time.h" -

37 #include "verify.h" -

38 -

39 #ifndef MAX -

40 # define MAX(a, b) ((a) > (b) ? (a) : (b)) -

41 #endif -

42 -

43 #define BILLION (1000 * 1000 * 1000) -

44 -

45 /* Best possible resolution that utimens can set and stat can return, -

46 due to system-call limitations. It must be a power of 10 that is -

47 no greater than 1 billion. */ -

48 #if HAVE_UTIMENSAT -

49 enum { SYSCALL_RESOLUTION = 1 }; -

50 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ -

51 /* On native Windows, file times have 100 ns resolution. See -

52 <https://msdn.microsoft.com/en-us/library/ms724284.aspx> */ -

53 enum { SYSCALL_RESOLUTION = 100 }; -

54 #elif ((HAVE_FUTIMESAT || HAVE_WORKING_UTIMES) \ -

55 && (defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC \ -

56 || defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC \ -

57 || defined HAVE_STRUCT_STAT_ST_ATIMENSEC \ -

58 || defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC \ -

59 || defined HAVE_STRUCT_STAT_ST_SPARE1)) -

60 enum { SYSCALL_RESOLUTION = 1000 }; -

61 #else -

62 enum { SYSCALL_RESOLUTION = BILLION }; -

63 #endif -

64 -

65 /* Describe a file system and its timestamp resolution in nanoseconds. */ -

66 struct fs_res -

67 { -

68 /* Device number of file system. */ -

69 dev_t dev; -

70 -

71 /* An upper bound on the timestamp resolution of this file system, -

72 ignoring any resolution that cannot be set via utimens. It is -

73 represented by an integer count of nanoseconds. It must be -

74 either 2 billion, or a power of 10 that is no greater than a -

75 billion and is no less than SYSCALL_RESOLUTION. */ -

76 int resolution; -

77 -

78 /* True if RESOLUTION is known to be exact, and is not merely an -

79 upper bound on the true resolution. */ -

80 bool exact; -

81 }; -

82 -

83 /* Hash some device info. */ -

84 static size_t -

85 dev_info_hash (void const *x, size_t table_size) -

86 { -

87 struct fs_res const *p = x; -

88 -

89 /* Beware signed arithmetic gotchas. */ -

if (TYPE_SIGNED (dev_t) && SIZE_MAX < MAX (INT_MAX, TYPE_MAXIMUM (dev_t)))

(! ((dev_t) 0 < (dev_t) -1))	Description
TRUE	never evaluated
FALSE	evaluated 4 times by 1 test Evaluated by: cp

(1844674407370...) * 2 + 1)))))	Description
TRUE	never evaluated
FALSE	never evaluated

0-4

91 { -

92 uintmax_t dev = p->dev; -

return dev % table_size;

never executed: return dev % table_size;

94 } -

95 -

return p->dev % table_size;

executed 4 times by 1 test: return p->dev % table_size;

Executed by:

97 } -

98 -

99 /* Compare two dev_info structs. */ -

100 static bool -

101 dev_info_compare (void const *x, void const *y) -

102 { -

103 struct fs_res const *a = x; -

104 struct fs_res const *b = y; -

105

return a->dev == b->dev;

executed 2 times by 1 test: return a->dev == b->dev;

Executed by:

106 } -

107 -

108 /* Return -1, 0, 1 based on whether the destination file (relative -

109 to openat-like directory file descriptor DFD with name -

110 DST_NAME and status DST_STAT) is older than SRC_STAT, the same age -

111 as SRC_STAT, or newer than SRC_STAT, respectively. -

112 -

113 DST_NAME may be NULL if OPTIONS is 0. -

114 -

115 If OPTIONS & UTIMECMP_TRUNCATE_SOURCE, do the comparison after SRC is -

116 converted to the destination's timestamp resolution as filtered through -

117 utimens. In this case, return -2 if the exact answer cannot be -

118 determined; this can happen only if the timestamps are very close and -

119 there is some trouble accessing the file system (e.g., the user does not -

120 have permission to futz with the destination's timestamps). */ -

121 -

122 int -

123 utimecmp (char const *dst_name, -

124 struct stat const *dst_stat, -

125 struct stat const *src_stat, -

126 int options) -

127 { -

128

return utimecmpat (AT_FDCWD, dst_name, dst_stat, src_stat, options);

executed 16 times by 2 tests: return utimecmpat ( -100 , dst_name, dst_stat, src_stat, options);

Executed by:

129 } -

130 -

131 int -

132 utimecmpat (int dfd, char const *dst_name, -

133 struct stat const *dst_stat, -

134 struct stat const *src_stat, -

135 int options) -

136 { -

137 /* Things to watch out for: -

138 -

139 The code uses a static hash table internally and is not safe in the -

140 presence of signals, multiple threads, etc. However, memory pressure -

141 that prevents use of the hash table is not fatal - we just fall back -

142 to redoing the computations on every call in that case. -

143 -

144 int and long int might be 32 bits. Many of the calculations store -

145 numbers up to 2 billion, and multiply by 10; they have to avoid -

146 multiplying 2 billion by 10, as this exceeds 32-bit capabilities. -

147 -

148 time_t might be unsigned. */ -

149 -

150 verify (TYPE_IS_INTEGER (time_t)); -

151 -

152 /* Destination and source timestamps. */ -

153 time_t dst_s = dst_stat->st_mtime; -

154 time_t src_s = src_stat->st_mtime; -

155 int dst_ns = get_stat_mtime_ns (dst_stat); -

156 int src_ns = get_stat_mtime_ns (src_stat); -

157 -

158

if (options & UTIMECMP_TRUNCATE_SOURCE)

options & UTIM...RUNCATE_SOURCE	Description
TRUE	evaluated 8 times by 1 test Evaluated by: cp
FALSE	evaluated 8 times by 2 tests Evaluated by: cp mv

159 { -

160 /* Look up the timestamp resolution for the destination device. */ -

161 -

162 /* Hash table for caching information learned about devices. */ -

163 static Hash_table *ht; -

164 -

165 /* Information about the destination file system. */ -

166 static struct fs_res *new_dst_res; -

167 struct fs_res *dst_res = NULL; -

168 struct fs_res tmp_dst_res; -

169 -

170 /* timestamp resolution in nanoseconds. */ -

171 int res; -

172 -

173 /* Quick exit, if possible. Since the worst resolution is 2 -

174 seconds, anything that differs by more than that does not -

175 needs source truncation. */ -

176

if (dst_s == src_s && dst_ns == src_ns)

dst_s == src_s	Description
TRUE	evaluated 4 times by 1 test Evaluated by: cp
FALSE	evaluated 4 times by 1 test Evaluated by: cp

dst_ns == src_ns	Description
TRUE	never evaluated
FALSE	evaluated 4 times by 1 test Evaluated by: cp

0-4

177

return 0;

never executed: return 0;

178

if (dst_s <= src_s - 2)

dst_s <= src_s - 2	Description
TRUE	evaluated 2 times by 1 test Evaluated by: cp
FALSE	evaluated 6 times by 1 test Evaluated by: cp

2-6

179

return -1;

executed 2 times by 1 test: return -1;

Executed by:

180

if (src_s <= dst_s - 2)

src_s <= dst_s - 2	Description
TRUE	evaluated 2 times by 1 test Evaluated by: cp
FALSE	evaluated 4 times by 1 test Evaluated by: cp

2-4

181

return 1;

executed 2 times by 1 test: return 1;

Executed by:

182 -

183 /* Try to do a hash lookup, but fall back to stack variables and -

184 recomputation on low memory situations. */ -

185

if (! ht)

! ht	Description
TRUE	evaluated 2 times by 1 test Evaluated by: cp
FALSE	evaluated 2 times by 1 test Evaluated by: cp

186

ht = hash_initialize (16, NULL, dev_info_hash, dev_info_compare, free);

executed 2 times by 1 test: ht = hash_initialize (16, ((void *)0) , dev_info_hash, dev_info_compare, free);

Executed by:

187

if (ht)

ht	Description
TRUE	evaluated 4 times by 1 test Evaluated by: cp
FALSE	never evaluated

0-4

188 { -

189

if (! new_dst_res)

! new_dst_res	Description
TRUE	evaluated 4 times by 1 test Evaluated by: cp
FALSE	never evaluated

0-4

190 { -

191 new_dst_res = malloc (sizeof *new_dst_res); -

192

if (!new_dst_res)

!new_dst_res	Description
TRUE	never evaluated
FALSE	evaluated 4 times by 1 test Evaluated by: cp

0-4

193

goto low_memory;

never executed: goto low_memory;

194 new_dst_res->resolution = 2 * BILLION; -

195 new_dst_res->exact = false; -

196

}

executed 4 times by 1 test: end of block

Executed by:

197 new_dst_res->dev = dst_stat->st_dev; -

198 dst_res = hash_insert (ht, new_dst_res); -

199

if (! dst_res)

! dst_res	Description
TRUE	never evaluated
FALSE	evaluated 4 times by 1 test Evaluated by: cp

0-4

200

goto low_memory;

never executed: goto low_memory;

201 -

202

if (dst_res == new_dst_res)

dst_res == new_dst_res	Description
TRUE	evaluated 2 times by 1 test Evaluated by: cp
FALSE	evaluated 2 times by 1 test Evaluated by: cp

203 { -

204 /* NEW_DST_RES is now in use in the hash table, so allocate a -

205 new entry next time. */ -

206 new_dst_res = NULL; -

207

}

executed 2 times by 1 test: end of block

Executed by:

208

}

executed 4 times by 1 test: end of block

Executed by:

209 else -

210 { -

211 low_memory: -

212

if (ht)

ht	Description
TRUE	never evaluated
FALSE	never evaluated

213 { -

214 tmp_dst_res.dev = dst_stat->st_dev; -

215 dst_res = hash_lookup (ht, &tmp_dst_res); -

216

}

never executed: end of block

217

if (!dst_res)

!dst_res	Description
TRUE	never evaluated
FALSE	never evaluated

218 { -

219 dst_res = &tmp_dst_res; -

220 dst_res->resolution = 2 * BILLION; -

221 dst_res->exact = false; -

222

}

never executed: end of block

223

}

never executed: end of block

224 -

225 res = dst_res->resolution; -

226 -

227 #ifdef _PC_TIMESTAMP_RESOLUTION -

228 /* If the system will tell us the resolution, we're set! */ -

229 if (! dst_res->exact) -

230 { -

231 res = -1; -

232 if (dfd == AT_FDCWD) -

233 res = pathconf (dst_name, _PC_TIMESTAMP_RESOLUTION); -

234 else -

235 { -

236 char *dstdir = mdir_name (dst_name); -

237 if (dstdir) -

238 { -

239 int destdirfd = openat (dfd, dstdir, -

240 O_SEARCH | O_CLOEXEC | O_DIRECTORY); -

241 if (0 <= destdirfd) -

242 { -

243 res = fpathconf (destdirfd, _PC_TIMESTAMP_RESOLUTION); -

244 close (destdirfd); -

245 } -

246 free (dstdir); -

247 } -

248 } -

249 if (0 < res) -

250 { -

251 dst_res->resolution = res; -

252 dst_res->exact = true; -

253 } -

254 } -

255 #endif -

256 -

257

if (! dst_res->exact)

! dst_res->exact	Description
TRUE	evaluated 2 times by 1 test Evaluated by: cp
FALSE	evaluated 2 times by 1 test Evaluated by: cp

258 { -

259 /* This file system's resolution is not known exactly. -

260 Deduce it, and store the result in the hash table. */ -

261 -

262 time_t dst_a_s = dst_stat->st_atime; -

263 time_t dst_c_s = dst_stat->st_ctime; -

264 time_t dst_m_s = dst_s; -

265 int dst_a_ns = get_stat_atime_ns (dst_stat); -

266 int dst_c_ns = get_stat_ctime_ns (dst_stat); -

267 int dst_m_ns = dst_ns; -

268 -

269 /* Set RES to an upper bound on the file system resolution -

270 (after truncation due to SYSCALL_RESOLUTION) by inspecting -

271 the atime, ctime and mtime of the existing destination. -

272 We don't know of any file system that stores atime or -

273 ctime with a higher precision than mtime, so it's valid to -

274 look at them too. */ -

275 { -

276 bool odd_second = (dst_a_s | dst_c_s | dst_m_s) & 1; -

277 -

278

if (SYSCALL_RESOLUTION == BILLION)

SYSCALL_RESOLU...* 1000 * 1000)	Description
TRUE	never evaluated
FALSE	evaluated 2 times by 1 test Evaluated by: cp

0-2

279 { -

280

if (odd_second | dst_a_ns | dst_c_ns | dst_m_ns)

odd_second \| d..._ns \| dst_m_ns	Description
TRUE	never evaluated
FALSE	never evaluated

281

res = BILLION;

never executed: res = (1000 * 1000 * 1000);

282

}

never executed: end of block

283 else -

284 { -

285 int a = dst_a_ns; -

286 int c = dst_c_ns; -

287 int m = dst_m_ns; -

288 -

289 /* Write it this way to avoid mistaken GCC warning -

290 about integer overflow in constant expression. */ -

291 int SR10 = SYSCALL_RESOLUTION; SR10 *= 10; -

292 -

293

if ((a % SR10 | c % SR10 | m % SR10) != 0)

(a % SR10 \| c ...m % SR10) != 0	Description
TRUE	evaluated 2 times by 1 test Evaluated by: cp
FALSE	never evaluated

0-2

294

res = SYSCALL_RESOLUTION;

executed 2 times by 1 test: res = SYSCALL_RESOLUTION;

Executed by:

295 else -

296 for (res = SR10, a /= SR10, c /= SR10, m /= SR10; -

297

(res < dst_res->resolution

res < dst_res->resolution	Description
TRUE	never evaluated
FALSE	never evaluated

298

&& (a % 10 | c % 10 | m % 10) == 0);

(a % 10 \| c % ...\| m % 10) == 0	Description
TRUE	never evaluated
FALSE	never evaluated

299 res *= 10, a /= 10, c /= 10, m /= 10) -

300

if (res == BILLION)

res == (1000 * 1000 * 1000)	Description
TRUE	never evaluated
FALSE	never evaluated

301 { -

302

if (! odd_second)

! odd_second	Description
TRUE	never evaluated
FALSE	never evaluated

303

res *= 2;

never executed: res *= 2;

304

break;

never executed: break;

305 } -

306

}

executed 2 times by 1 test: end of block

Executed by:

307 -

308 dst_res->resolution = res; -

309 } -

310 -

311

if (SYSCALL_RESOLUTION < res)

SYSCALL_RESOLUTION < res	Description
TRUE	never evaluated
FALSE	evaluated 2 times by 1 test Evaluated by: cp

0-2

312 { -

313 struct timespec timespec[2]; -

314 struct stat dst_status; -

315 -

316 /* Ignore source timestamp information that must necessarily -

317 be lost when filtered through utimens. */ -

318 src_ns -= src_ns % SYSCALL_RESOLUTION; -

319 -

320 /* If the timestamps disagree widely enough, there's no need -

321 to interrogate the file system to deduce the exact -

322 timestamp resolution; return the answer directly. */ -

323 { -

324 time_t s = src_s & ~ (res == 2 * BILLION ? 1 : 0); -

325

if (src_s < dst_s || (src_s == dst_s && src_ns <= dst_ns))

src_s < dst_s	Description
TRUE	never evaluated
FALSE	never evaluated

src_s == dst_s	Description
TRUE	never evaluated
FALSE	never evaluated

src_ns <= dst_ns	Description
TRUE	never evaluated
FALSE	never evaluated

326

return 1;

never executed: return 1;

327

if (dst_s < s

dst_s < s	Description
TRUE	never evaluated
FALSE	never evaluated

328

|| (dst_s == s && dst_ns < src_ns - src_ns % res))

dst_s == s	Description
TRUE	never evaluated
FALSE	never evaluated

dst_ns < src_ns - src_ns % res	Description
TRUE	never evaluated
FALSE	never evaluated

329

return -1;

never executed: return -1;

330 } -

331 -

332 /* Determine the actual timestamp resolution for the -

333 destination file system (after truncation due to -

334 SYSCALL_RESOLUTION) by setting the access timestamp of the -

335 destination to the existing access time, except with -

336 trailing nonzero digits. */ -

337 -

338 timespec[0].tv_sec = dst_a_s; -

339 timespec[0].tv_nsec = dst_a_ns; -

340 timespec[1].tv_sec = dst_m_s | (res == 2 * BILLION); -

341 timespec[1].tv_nsec = dst_m_ns + res / 9; -

342 -

343

if (utimensat (dfd, dst_name, timespec, AT_SYMLINK_NOFOLLOW))

utimensat (dfd...espec, 0x100 )	Description
TRUE	never evaluated
FALSE	never evaluated

344

return -2;

never executed: return -2;

345 -

346 /* Read the modification time that was set. */ -

347 { -

348 int stat_result -

349 = fstatat (dfd, dst_name, &dst_status, AT_SYMLINK_NOFOLLOW); -

350 -

351

if (stat_result

stat_result \| ...s) ^ dst_m_ns)	Description
TRUE	never evaluated
FALSE	never evaluated

352

| (dst_status.st_mtime ^ dst_m_s)

stat_result \| ...s) ^ dst_m_ns)	Description
TRUE	never evaluated
FALSE	never evaluated

353

| (get_stat_mtime_ns (&dst_status) ^ dst_m_ns))

stat_result \| ...s) ^ dst_m_ns)	Description
TRUE	never evaluated
FALSE	never evaluated

354 { -

355 /* The modification time changed, or we can't tell whether -

356 it changed. Change it back as best we can. */ -

357 timespec[1].tv_sec = dst_m_s; -

358 timespec[1].tv_nsec = dst_m_ns; -

359 utimensat (dfd, dst_name, timespec, AT_SYMLINK_NOFOLLOW); -

360

}

never executed: end of block

361 -

362

if (stat_result != 0)

stat_result != 0	Description
TRUE	never evaluated
FALSE	never evaluated

363

return -2;

never executed: return -2;

364 } -

365 -

366 /* Determine the exact resolution from the modification time -

367 that was read back. */ -

368 { -

369 int old_res = res; -

370 int a = (BILLION * (dst_status.st_mtime & 1) -

371 + get_stat_mtime_ns (&dst_status)); -

372 -

373 res = SYSCALL_RESOLUTION; -

374 -

375

for (a /= res; a % 10 == 0; a /= 10)

a % 10 == 0	Description
TRUE	never evaluated
FALSE	never evaluated

376 { -

377

if (res == BILLION)

res == (1000 * 1000 * 1000)	Description
TRUE	never evaluated
FALSE	never evaluated

378 { -

379 res *= 2; -

380

break;

never executed: break;

381 } -

382 res *= 10; -

383

if (res == old_res)

res == old_res	Description
TRUE	never evaluated
FALSE	never evaluated

384

break;

never executed: break;

385

}

never executed: end of block

386 } -

387

}

never executed: end of block

388 -

389 dst_res->resolution = res; -

390 dst_res->exact = true; -

391

}

executed 2 times by 1 test: end of block

Executed by:

392 -

393 /* Truncate the source's timestamp according to the resolution. */ -

394 src_s &= ~ (res == 2 * BILLION ? 1 : 0); -

395 src_ns -= src_ns % res; -

396

}

executed 4 times by 1 test: end of block

Executed by:

397 -

398 /* Compare the timestamps and return -1, 0, 1 accordingly. */ -

399

return (dst_s < src_s ? -1

executed 12 times by 2 tests: return (dst_s < src_s ? -1 : dst_s > src_s ? 1 : dst_ns < src_ns ? -1 : dst_ns > src_ns);

Executed by:

400

: dst_s > src_s ? 1

executed 12 times by 2 tests: return (dst_s < src_s ? -1 : dst_s > src_s ? 1 : dst_ns < src_ns ? -1 : dst_ns > src_ns);

Executed by:

401

: dst_ns < src_ns ? -1

executed 12 times by 2 tests: return (dst_s < src_s ? -1 : dst_s > src_s ? 1 : dst_ns < src_ns ? -1 : dst_ns > src_ns);

Executed by:

402

: dst_ns > src_ns);

executed 12 times by 2 tests: return (dst_s < src_s ? -1 : dst_s > src_s ? 1 : dst_ns < src_ns ? -1 : dst_ns > src_ns);

Executed by:

403 } -

Source code

Switch to Preprocessed file

Generated by Squish Coco 4.1.2