1 /* stat-related time functions. 2 3 Copyright (C) 2005, 2007, 2009-2018 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://msdn.microsoft.com/en-us/library/14h5k7ff(VS.80).aspx>. */ 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 253