* moved bpf syscall, added some bpf instructions and tests
* had to move bpf out of bits so that a freestanding target could import it
* removed line
* fixed imports
This commit reimagines `std.os.windows.GetFinalPathNameByHandle`
using `DeviceIoControl` to query the OS mount manager for the DOS
(symlink) paths for the given NT volume name. In particular,
it uses `IOCTL_MOUNTMGR_QUERY_POINTS` ioctl opcode to query the
manager for the available moount points.
Favour newer API which uses `NtQueryInformationFile` with class flags
`FileNormalizedNameInformation` and `FileVolumeNameInformation`
instead of lower-level `NtQueryObject`. `NtQueryObject` is still
used as a fallback in case the former are unavailable.
This commit proposes an initial draft of `GetPathNameByHandle` function
which wraps NT syscalls and strives to emulate (currently only
partially) the `kernel32.GetFinalPathNameByHandleW` function.
This shaves off one syscall (we use one instead of two if we were to
use `windows.OpenFile` wrapper). Clean up flag generation in `OpenFile`.
Hopefully, we're in a much better place to *almost* support `openW`
and `openatW`.
This way, we can remove more `kernel32` calls such as `RemoveDirectoryW`
or `DeleteFileW`, and use `std.os.windows.DeleteFile` instead which
is purely NT-based.
Replace them with `std.os.windows.OpenFile` instead. To allow
creation/opening of directories, `std.os.windows.OpenFileOptions`
now features a `.expect_dir: bool` member which is meant to emualate
POSIX's `O_DIRECTORY` flag.
As discussed in the previous commit, it would be better to avoid
function pointers to syscalls and explicitly split the control
path into two function calls instead. This commit addresses that
for `std.os.windows.DeviceIoControl`.
This commit adds a Zig wrapper for `kernel32.DeviceIoControl` which
applies ReactOS logic for deciding whether to use
`ntdll.NtDeviceIoControlFile` or `ntdll.NtFsControlFile` based on the
value of passed `IO_CONTROL_CODE`. The decision logic is based on the
logic found in ReactOS found in the following [link].
Thanks to Daurnimator for finding this bit in ReactOS!
[link]: https://doxygen.reactos.org/d3/d74/deviceio_8c.html
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`.
