Otherwise, the behaviour can lead to unexpected results, resulting
in removing an entire tree that's not necessarily under the root.
Furthermore, this change is needed if are to properly handle dir
symlinks on Windows. Without explicitly requiring that a directory
or file is opened with `FILE_OPEN_REPARSE_POINT`, Windows automatically
dereferences all symlinks along the way. This commit adds another
option to `OpenDirOptions`, namely `.no_follow`, which defaults to
`false` and can be used to specifically open a directory symlink on
Windows or call `openat` with `O_NOFOLLOW` flag in POSIX.
This way `std.fs.symlinkAbsolute` becomes cross-platform and we can
legally include `SymlinkFlags` as an argument that's only used on
Windows. Also, now `std.os.symlink` generates a compile error on
Windows with a message to instead use `std.os.windows.CreateSymbolicLink`.
Finally, this PR also reshuffles the tests between `std.os.test` and
`std.fs.test`.
Also, add more informative `@compileError` in a few `std.os` functions
that would otherwise yield a cryptic compile error when targeting
WASI. Finally, enhance docs in a few places and add test case for
`fstatat`.
Adds Windows stub (still needs to be implemented on Windows),
adds WASI implementation, adds unit test testing basic chain of
ops: create file -> symlink -> readlink.
ERROR_DIRECTORY (267) is returned from kernel32.RemoveDirectoryW if the path is not a directory. Note also that os.DirectDirError already includes NotDir
Before: error.Unexpected: GetLastError(267): The directory name is invalid.
After: error: NotDir
* improve docs
* add TODO comments for things that don't have open issues
* remove redundant namespacing of struct fields
* guard against ioctl returning EINTR
* remove the general std.os.ioctl function in favor of the specific
ioctl_SIOCGIFINDEX function. This allows us to have a more precise
error set, and more type-safe API.
