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1 | /* stat-related time functions. |
2 | ||
3 | Copyright (C) 2005, 2007, 2009-2019 Free Software Foundation, Inc. | |
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 | #ifndef STAT_TIME_H | |
21 | #define STAT_TIME_H 1 | |
22 | ||
23 | #include "intprops.h" | |
24 | ||
25 | #include <errno.h> | |
26 | #include <stddef.h> | |
27 | #include <sys/stat.h> | |
28 | #include <time.h> | |
29 | ||
30 | #ifndef _GL_INLINE_HEADER_BEGIN | |
31 | #error "Please include config.h first." | |
32 | #endif | |
33 | _GL_INLINE_HEADER_BEGIN | |
34 | #ifndef _GL_STAT_TIME_INLINE | |
35 | # define _GL_STAT_TIME_INLINE _GL_INLINE | |
36 | #endif | |
37 | ||
38 | #ifdef __cplusplus | |
39 | extern "C" { | |
40 | #endif | |
41 | ||
42 | /* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type | |
43 | struct timespec, if available. If not, then STAT_TIMESPEC_NS (ST, | |
44 | ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST, | |
45 | if available. ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim | |
46 | for access, status change, data modification, or birth (creation) | |
47 | time respectively. | |
48 | ||
49 | These macros are private to stat-time.h. */ | |
50 | #if _GL_WINDOWS_STAT_TIMESPEC || defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC | |
51 | # if _GL_WINDOWS_STAT_TIMESPEC || defined TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC | |
52 | # define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim) | |
53 | # else | |
54 | # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec) | |
55 | # endif | |
56 | #elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC | |
57 | # define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec) | |
58 | #elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC | |
59 | # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec) | |
60 | #elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC | |
61 | # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec) | |
62 | #endif | |
63 | ||
64 | /* Return the nanosecond component of *ST's access time. */ | |
65 | _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE | |
66 | get_stat_atime_ns (struct stat const *st) | |
67 | { | |
68 | # if defined STAT_TIMESPEC | |
69 | return STAT_TIMESPEC (st, st_atim).tv_nsec; | |
70 | # elif defined STAT_TIMESPEC_NS | |
71 | return STAT_TIMESPEC_NS (st, st_atim); | |
72 | # else | |
73 | return 0; | |
74 | # endif | |
75 | } | |
76 | ||
77 | /* Return the nanosecond component of *ST's status change time. */ | |
78 | _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE | |
79 | get_stat_ctime_ns (struct stat const *st) | |
80 | { | |
81 | # if defined STAT_TIMESPEC | |
82 | return STAT_TIMESPEC (st, st_ctim).tv_nsec; | |
83 | # elif defined STAT_TIMESPEC_NS | |
84 | return STAT_TIMESPEC_NS (st, st_ctim); | |
85 | # else | |
86 | return 0; | |
87 | # endif | |
88 | } | |
89 | ||
90 | /* Return the nanosecond component of *ST's data modification time. */ | |
91 | _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE | |
92 | get_stat_mtime_ns (struct stat const *st) | |
93 | { | |
94 | # if defined STAT_TIMESPEC | |
95 | return STAT_TIMESPEC (st, st_mtim).tv_nsec; | |
96 | # elif defined STAT_TIMESPEC_NS | |
97 | return STAT_TIMESPEC_NS (st, st_mtim); | |
98 | # else | |
99 | return 0; | |
100 | # endif | |
101 | } | |
102 | ||
103 | /* Return the nanosecond component of *ST's birth time. */ | |
104 | _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE | |
105 | get_stat_birthtime_ns (struct stat const *st _GL_UNUSED) | |
106 | { | |
107 | # if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC | |
108 | return STAT_TIMESPEC (st, st_birthtim).tv_nsec; | |
109 | # elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC | |
110 | return STAT_TIMESPEC_NS (st, st_birthtim); | |
111 | # else | |
112 | return 0; | |
113 | # endif | |
114 | } | |
115 | ||
116 | /* Return *ST's access time. */ | |
117 | _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE | |
118 | get_stat_atime (struct stat const *st) | |
119 | { | |
120 | #ifdef STAT_TIMESPEC | |
121 | return STAT_TIMESPEC (st, st_atim); | |
122 | #else | |
123 | struct timespec t; | |
124 | t.tv_sec = st->st_atime; | |
125 | t.tv_nsec = get_stat_atime_ns (st); | |
126 | return t; | |
127 | #endif | |
128 | } | |
129 | ||
130 | /* Return *ST's status change time. */ | |
131 | _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE | |
132 | get_stat_ctime (struct stat const *st) | |
133 | { | |
134 | #ifdef STAT_TIMESPEC | |
135 | return STAT_TIMESPEC (st, st_ctim); | |
136 | #else | |
137 | struct timespec t; | |
138 | t.tv_sec = st->st_ctime; | |
139 | t.tv_nsec = get_stat_ctime_ns (st); | |
140 | return t; | |
141 | #endif | |
142 | } | |
143 | ||
144 | /* Return *ST's data modification time. */ | |
145 | _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE | |
146 | get_stat_mtime (struct stat const *st) | |
147 | { | |
148 | #ifdef STAT_TIMESPEC | |
149 | return STAT_TIMESPEC (st, st_mtim); | |
150 | #else | |
151 | struct timespec t; | |
152 | t.tv_sec = st->st_mtime; | |
153 | t.tv_nsec = get_stat_mtime_ns (st); | |
154 | return t; | |
155 | #endif | |
156 | } | |
157 | ||
158 | /* Return *ST's birth time, if available; otherwise return a value | |
159 | with tv_sec and tv_nsec both equal to -1. */ | |
160 | _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE | |
161 | get_stat_birthtime (struct stat const *st _GL_UNUSED) | |
162 | { | |
163 | struct timespec t; | |
164 | ||
165 | #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \ | |
166 | || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC) | |
167 | t = STAT_TIMESPEC (st, st_birthtim); | |
168 | #elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC | |
169 | t.tv_sec = st->st_birthtime; | |
170 | t.tv_nsec = st->st_birthtimensec; | |
171 | #elif defined _WIN32 && ! defined __CYGWIN__ | |
172 | /* Native Windows platforms (but not Cygwin) put the "file creation | |
173 | time" in st_ctime (!). See | |
174 | <https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/stat-functions>. */ | |
175 | # if _GL_WINDOWS_STAT_TIMESPEC | |
176 | t = st->st_ctim; | |
177 | # else | |
178 | t.tv_sec = st->st_ctime; | |
179 | t.tv_nsec = 0; | |
180 | # endif | |
181 | #else | |
182 | /* Birth time is not supported. */ | |
183 | t.tv_sec = -1; | |
184 | t.tv_nsec = -1; | |
185 | #endif | |
186 | ||
187 | #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \ | |
188 | || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \ | |
189 | || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC) | |
190 | /* FreeBSD and NetBSD sometimes signal the absence of knowledge by | |
191 | using zero. Attempt to work around this problem. Alas, this can | |
192 | report failure even for valid timestamps. Also, NetBSD | |
193 | sometimes returns junk in the birth time fields; work around this | |
194 | bug if it is detected. */ | |
195 | if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000)) | |
196 | { | |
197 | t.tv_sec = -1; | |
198 | t.tv_nsec = -1; | |
199 | } | |
200 | #endif | |
201 | ||
202 | return t; | |
203 | } | |
204 | ||
205 | /* If a stat-like function returned RESULT, normalize the timestamps | |
206 | in *ST, in case this platform suffers from the Solaris 11 bug where | |
207 | tv_nsec might be negative. Return the adjusted RESULT, setting | |
208 | errno to EOVERFLOW if normalization overflowed. This function | |
209 | is intended to be private to this .h file. */ | |
210 | _GL_STAT_TIME_INLINE int | |
211 | stat_time_normalize (int result, struct stat *st _GL_UNUSED) | |
212 | { | |
213 | #if defined __sun && defined STAT_TIMESPEC | |
214 | if (result == 0) | |
215 | { | |
216 | long int timespec_hz = 1000000000; | |
217 | short int const ts_off[] = { offsetof (struct stat, st_atim), | |
218 | offsetof (struct stat, st_mtim), | |
219 | offsetof (struct stat, st_ctim) }; | |
220 | int i; | |
221 | for (i = 0; i < sizeof ts_off / sizeof *ts_off; i++) | |
222 | { | |
223 | struct timespec *ts = (struct timespec *) ((char *) st + ts_off[i]); | |
224 | long int q = ts->tv_nsec / timespec_hz; | |
225 | long int r = ts->tv_nsec % timespec_hz; | |
226 | if (r < 0) | |
227 | { | |
228 | r += timespec_hz; | |
229 | q--; | |
230 | } | |
231 | ts->tv_nsec = r; | |
232 | /* Overflow is possible, as Solaris 11 stat can yield | |
233 | tv_sec == TYPE_MINIMUM (time_t) && tv_nsec == -1000000000. | |
234 | INT_ADD_WRAPV is OK, since time_t is signed on Solaris. */ | |
235 | if (INT_ADD_WRAPV (q, ts->tv_sec, &ts->tv_sec)) | |
236 | { | |
237 | errno = EOVERFLOW; | |
238 | return -1; | |
239 | } | |
240 | } | |
241 | } | |
242 | #endif | |
243 | return result; | |
244 | } | |
245 | ||
246 | #ifdef __cplusplus | |
247 | } | |
248 | #endif | |
249 | ||
250 | _GL_INLINE_HEADER_END | |
251 | ||
252 | #endif |