libc-bottom-half/cloudlibc/src/libc/sys/stat/stat_impl.h

   1 // Copyright (c) 2015-2017 Nuxi, https://nuxi.nl/
   2 //
   3 // SPDX-License-Identifier: BSD-2-Clause
   4
   5 #ifndef SYS_STAT_STAT_IMPL_H
   6 #define SYS_STAT_STAT_IMPL_H
   7
   8 #include <common/time.h>
   9
  10 #include <sys/stat.h>
  11
  12 #include <assert.h>
  13 #include <wasi/api.h>
  14 #include <stdbool.h>
  15
  16 static_assert(S_ISBLK(S_IFBLK), "Value mismatch");
  17 static_assert(S_ISCHR(S_IFCHR), "Value mismatch");
  18 static_assert(S_ISDIR(S_IFDIR), "Value mismatch");
  19 static_assert(S_ISFIFO(S_IFIFO), "Value mismatch");
  20 static_assert(S_ISLNK(S_IFLNK), "Value mismatch");
  21 static_assert(S_ISREG(S_IFREG), "Value mismatch");
  22 static_assert(S_ISSOCK(S_IFSOCK), "Value mismatch");
  23
  24 static inline void to_public_stat(const __wasi_filestat_t *in,
  25                                   struct stat *out) {
  26   // Ensure that we don't truncate any values.
  27 #ifdef __wasilibc_unmodified_upstream
  28   static_assert(sizeof(in->st_dev) == sizeof(out->st_dev), "Size mismatch");
  29   static_assert(sizeof(in->st_ino) == sizeof(out->st_ino), "Size mismatch");
  30   static_assert(sizeof(in->st_filetype) == sizeof(out->__st_filetype),
  31                 "Size mismatch");
  32 #else
  33   static_assert(sizeof(in->dev) == sizeof(out->st_dev), "Size mismatch");
  34   static_assert(sizeof(in->ino) == sizeof(out->st_ino), "Size mismatch");
  35   /*
  36    * The non-standard __st_filetype field appears to only be used for shared
  37    * memory, which we don't currently support.
  38    */
  39 #endif
  40 #ifdef __wasilibc_unmodified_upstream
  41   static_assert(sizeof(in->st_nlink) == sizeof(out->st_nlink), "Size mismatch");
  42   static_assert(sizeof(in->st_size) == sizeof(out->st_size), "Size mismatch");
  43 #else
  44   /* nlink_t is 64-bit on wasm32, following the x32 ABI. */
  45   static_assert(sizeof(in->nlink) <= sizeof(out->st_nlink), "Size shortfall");
  46   static_assert(sizeof(in->size) == sizeof(out->st_size), "Size mismatch");
  47 #endif
  48
  49   *out = (struct stat){
  50 #ifdef __wasilibc_unmodified_upstream
  51 #define COPY_FIELD(field) .field = in->field
  52       COPY_FIELD(st_dev),
  53       COPY_FIELD(st_ino),
  54       .__st_filetype = in->st_filetype,
  55       COPY_FIELD(st_nlink),
  56       COPY_FIELD(st_size),
  57 #undef COPY_FIELD
  58 #define COPY_TIMESPEC(field) .field = timestamp_to_timespec(in->field)
  59       COPY_TIMESPEC(st_atim),
  60       COPY_TIMESPEC(st_mtim),
  61       COPY_TIMESPEC(st_ctim),
  62 #undef COPY_TIMESPEC
  63 #else
  64       .st_dev = in->dev,
  65       .st_ino = in->ino,
  66       .st_nlink = in->nlink,
  67       .st_size = in->size,
  68       .st_atim = timestamp_to_timespec(in->atim),
  69       .st_mtim = timestamp_to_timespec(in->mtim),
  70       .st_ctim = timestamp_to_timespec(in->ctim),
  71 #endif
  72   };
  73
  74   // Convert file type to legacy types encoded in st_mode.
  75 #ifdef __wasilibc_unmodified_upstream
  76   switch (in->st_filetype) {
  77 #else
  78   switch (in->filetype) {
  79 #endif
  80     case __WASI_FILETYPE_BLOCK_DEVICE:
  81       out->st_mode |= S_IFBLK;
  82       break;
  83     case __WASI_FILETYPE_CHARACTER_DEVICE:
  84       out->st_mode |= S_IFCHR;
  85       break;
  86     case __WASI_FILETYPE_DIRECTORY:
  87       out->st_mode |= S_IFDIR;
  88       break;
  89     case __WASI_FILETYPE_REGULAR_FILE:
  90       out->st_mode |= S_IFREG;
  91       break;
  92     case __WASI_FILETYPE_SOCKET_DGRAM:
  93     case __WASI_FILETYPE_SOCKET_STREAM:
  94       out->st_mode |= S_IFSOCK;
  95       break;
  96     case __WASI_FILETYPE_SYMBOLIC_LINK:
  97       out->st_mode |= S_IFLNK;
  98       break;
  99   }
 100 }
 101
 102 static inline bool utimens_get_timestamps(const struct timespec *times,
 103 #ifdef __wasilibc_unmodified_upstream // fstat
 104                                           __wasi_filestat_t *fs,
 105                                           __wasi_fsflags_t *flags) {
 106 #else
 107                                           __wasi_timestamp_t *st_atim,
 108                                           __wasi_timestamp_t *st_mtim,
 109                                           __wasi_fstflags_t *flags) {
 110 #endif
 111   if (times == NULL) {
 112     // Update both timestamps.
 113 #ifdef __wasilibc_unmodified_upstream // fstat
 114     *flags = __WASI_FILESTAT_ATIM_NOW | __WASI_FILESTAT_MTIM_NOW;
 115 #else
 116     *flags = __WASI_FSTFLAGS_ATIM_NOW | __WASI_FSTFLAGS_MTIM_NOW;
 117 #endif
 118   } else {
 119     // Set individual timestamps.
 120     *flags = 0;
 121     switch (times[0].tv_nsec) {
 122       case UTIME_NOW:
 123 #ifdef __wasilibc_unmodified_upstream // fstat
 124         *flags |= __WASI_FILESTAT_ATIM_NOW;
 125 #else
 126         *flags |= __WASI_FSTFLAGS_ATIM_NOW;
 127 #endif
 128         break;
 129       case UTIME_OMIT:
 130         break;
 131       default:
 132 #ifdef __wasilibc_unmodified_upstream // fstat
 133         *flags |= __WASI_FILESTAT_ATIM;
 134         if (!timespec_to_timestamp_exact(&times[0], &fs->st_atim))
 135 #else
 136         *flags |= __WASI_FSTFLAGS_ATIM;
 137         if (!timespec_to_timestamp_exact(&times[0], st_atim))
 138 #endif
 139           return false;
 140         break;
 141     }
 142
 143     switch (times[1].tv_nsec) {
 144       case UTIME_NOW:
 145 #ifdef __wasilibc_unmodified_upstream // fstat
 146         *flags |= __WASI_FILESTAT_MTIM_NOW;
 147 #else
 148         *flags |= __WASI_FSTFLAGS_MTIM_NOW;
 149 #endif
 150         break;
 151       case UTIME_OMIT:
 152         break;
 153       default:
 154 #ifdef __wasilibc_unmodified_upstream // fstat
 155         *flags |= __WASI_FILESTAT_MTIM;
 156         if (!timespec_to_timestamp_exact(&times[1], &fs->st_mtim))
 157 #else
 158         *flags |= __WASI_FSTFLAGS_MTIM;
 159         if (!timespec_to_timestamp_exact(&times[1], st_mtim))
 160 #endif
 161           return false;
 162         break;
 163     }
 164   }
 165   return true;
 166 }
 167
 168 #endif