    //! This file contains thin wrappers around Windows-specific APIs, with these
    //! specific goals in mind:
    //! * Convert "errno"-style error codes into Zig errors.
    //! * When null-terminated or UTF16LE byte buffers are required, provide APIs which accept
    //!   slices as well as APIs which accept null-terminated UTF16LE byte buffers.

    const builtin = @import("builtin");
    const std = @import("../std.zig");
    const mem = std.mem;
    const assert = std.debug.assert;
    const math = std.math;
    const maxInt = std.math.maxInt;
    const native_arch = builtin.cpu.arch;

    test {
        if (builtin.os.tag == .windows) {
            _ = @import("windows/test.zig");
        }
    }

    pub const advapi32 = @import("windows/advapi32.zig");
    pub const kernel32 = @import("windows/kernel32.zig");
    pub const ntdll = @import("windows/ntdll.zig");
    pub const ole32 = @import("windows/ole32.zig");
    pub const psapi = @import("windows/psapi.zig");
    pub const shell32 = @import("windows/shell32.zig");
    pub const user32 = @import("windows/user32.zig");
    pub const ws2_32 = @import("windows/ws2_32.zig");
    pub const gdi32 = @import("windows/gdi32.zig");
    pub const winmm = @import("windows/winmm.zig");

    pub const self_process_handle = @intToPtr(HANDLE, maxInt(usize));

    pub const OpenError = error{
        IsDir,
        NotDir,
        FileNotFound,
        NoDevice,
        AccessDenied,
        PipeBusy,
        PathAlreadyExists,
        Unexpected,
        NameTooLong,
        WouldBlock,
    };

    pub const OpenFileOptions = struct {
        access_mask: ACCESS_MASK,
        dir: ?HANDLE = null,
        sa: ?*SECURITY_ATTRIBUTES = null,
        share_access: ULONG = FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE,
        creation: ULONG,
        io_mode: std.io.ModeOverride,
        /// If true, tries to open path as a directory.
        /// Defaults to false.
        filter: Filter = .file_only,
        /// If false, tries to open path as a reparse point without dereferencing it.
        /// Defaults to true.
        follow_symlinks: bool = true,

        pub const Filter = enum {
            /// Causes `OpenFile` to return `error.IsDir` if the opened handle would be a directory.
            file_only,
            /// Causes `OpenFile` to return `error.NotDir` if the opened handle would be a file.
            dir_only,
            /// `OpenFile` does not discriminate between opening files and directories.
            any,
        };
    };

    pub fn OpenFile(sub_path_w: []const u16, options: OpenFileOptions) OpenError!HANDLE {
        if (mem.eql(u16, sub_path_w, &[_]u16{'.'}) and options.filter == .file_only) {
            return error.IsDir;
        }
        if (mem.eql(u16, sub_path_w, &[_]u16{ '.', '.' }) and options.filter == .file_only) {
            return error.IsDir;
        }

        var result: HANDLE = undefined;

        const path_len_bytes = math.cast(u16, sub_path_w.len * 2) orelse return error.NameTooLong;
        var nt_name = UNICODE_STRING{
            .Length = path_len_bytes,
            .MaximumLength = path_len_bytes,
            .Buffer = @intToPtr([*]u16, @ptrToInt(sub_path_w.ptr)),
        };
        var attr = OBJECT_ATTRIBUTES{
            .Length = @sizeOf(OBJECT_ATTRIBUTES),
            .RootDirectory = if (std.fs.path.isAbsoluteWindowsWTF16(sub_path_w)) null else options.dir,
            .Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.

            .ObjectName = &nt_name,
            .SecurityDescriptor = if (options.sa) |ptr| ptr.lpSecurityDescriptor else null,
            .SecurityQualityOfService = null,
        };
        var io: IO_STATUS_BLOCK = undefined;
        const blocking_flag: ULONG = if (options.io_mode == .blocking) FILE_SYNCHRONOUS_IO_NONALERT else 0;
        const file_or_dir_flag: ULONG = switch (options.filter) {
            .file_only => FILE_NON_DIRECTORY_FILE,
            .dir_only => FILE_DIRECTORY_FILE,
            .any => 0,
        };
        // If we're not following symlinks, we need to ensure we don't pass in any synchronization flags such as FILE_SYNCHRONOUS_IO_NONALERT.

        const flags: ULONG = if (options.follow_symlinks) file_or_dir_flag | blocking_flag else file_or_dir_flag | FILE_OPEN_REPARSE_POINT;

        const rc = ntdll.NtCreateFile(
            &result,
            options.access_mask,
            &attr,
            &io,
            null,
            FILE_ATTRIBUTE_NORMAL,
            options.share_access,
            options.creation,
            flags,
            null,
            0,
        );
        switch (rc) {
            .SUCCESS => {
                if (std.io.is_async and options.io_mode == .evented) {
                    _ = CreateIoCompletionPort(result, std.event.Loop.instance.?.os_data.io_port, undefined, undefined) catch undefined;
                }
                return result;
            },
            .OBJECT_NAME_INVALID => unreachable,
            .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
            .OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
            .NO_MEDIA_IN_DEVICE => return error.NoDevice,
            .INVALID_PARAMETER => unreachable,
            .SHARING_VIOLATION => return error.AccessDenied,
            .ACCESS_DENIED => return error.AccessDenied,
            .PIPE_BUSY => return error.PipeBusy,
            .OBJECT_PATH_SYNTAX_BAD => unreachable,
            .OBJECT_NAME_COLLISION => return error.PathAlreadyExists,
            .FILE_IS_A_DIRECTORY => return error.IsDir,
            .NOT_A_DIRECTORY => return error.NotDir,
            .USER_MAPPED_FILE => return error.AccessDenied,
            .INVALID_HANDLE => unreachable,
            else => return unexpectedStatus(rc),
        }
    }

    pub const CreatePipeError = error{Unexpected};

    pub fn CreatePipe(rd: *HANDLE, wr: *HANDLE, sattr: *const SECURITY_ATTRIBUTES) CreatePipeError!void {
        if (kernel32.CreatePipe(rd, wr, sattr, 0) == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub fn CreateEventEx(attributes: ?*SECURITY_ATTRIBUTES, name: []const u8, flags: DWORD, desired_access: DWORD) !HANDLE {
        const nameW = try sliceToPrefixedFileW(name);
        return CreateEventExW(attributes, nameW.span().ptr, flags, desired_access);
    }

    pub fn CreateEventExW(attributes: ?*SECURITY_ATTRIBUTES, nameW: [*:0]const u16, flags: DWORD, desired_access: DWORD) !HANDLE {
        const handle = kernel32.CreateEventExW(attributes, nameW, flags, desired_access);
        if (handle) |h| {
            return h;
        } else {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const DeviceIoControlError = error{ AccessDenied, Unexpected };

    /// A Zig wrapper around `NtDeviceIoControlFile` and `NtFsControlFile` syscalls.
    /// It implements similar behavior to `DeviceIoControl` and is meant to serve
    /// as a direct substitute for that call.
    /// TODO work out if we need to expose other arguments to the underlying syscalls.
    pub fn DeviceIoControl(
        h: HANDLE,
        ioControlCode: ULONG,
        in: ?[]const u8,
        out: ?[]u8,
    ) DeviceIoControlError!void {
        // Logic from: https://doxygen.reactos.org/d3/d74/deviceio_8c.html

        const is_fsctl = (ioControlCode >> 16) == FILE_DEVICE_FILE_SYSTEM;

        var io: IO_STATUS_BLOCK = undefined;
        const in_ptr = if (in) |i| i.ptr else null;
        const in_len = if (in) |i| @intCast(ULONG, i.len) else 0;
        const out_ptr = if (out) |o| o.ptr else null;
        const out_len = if (out) |o| @intCast(ULONG, o.len) else 0;

        const rc = blk: {
            if (is_fsctl) {
                break :blk ntdll.NtFsControlFile(
                    h,
                    null,
                    null,
                    null,
                    &io,
                    ioControlCode,
                    in_ptr,
                    in_len,
                    out_ptr,
                    out_len,
                );
            } else {
                break :blk ntdll.NtDeviceIoControlFile(
                    h,
                    null,
                    null,
                    null,
                    &io,
                    ioControlCode,
                    in_ptr,
                    in_len,
                    out_ptr,
                    out_len,
                );
            }
        };
        switch (rc) {
            .SUCCESS => {},
            .PRIVILEGE_NOT_HELD => return error.AccessDenied,
            .ACCESS_DENIED => return error.AccessDenied,
            .INVALID_PARAMETER => unreachable,
            else => return unexpectedStatus(rc),
        }
    }

    pub fn GetOverlappedResult(h: HANDLE, overlapped: *OVERLAPPED, wait: bool) !DWORD {
        var bytes: DWORD = undefined;
        if (kernel32.GetOverlappedResult(h, overlapped, &bytes, @boolToInt(wait)) == 0) {
            switch (kernel32.GetLastError()) {
                .IO_INCOMPLETE => if (!wait) return error.WouldBlock else unreachable,
                else => |err| return unexpectedError(err),
            }
        }
        return bytes;
    }

    pub const SetHandleInformationError = error{Unexpected};

    pub fn SetHandleInformation(h: HANDLE, mask: DWORD, flags: DWORD) SetHandleInformationError!void {
        if (kernel32.SetHandleInformation(h, mask, flags) == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const RtlGenRandomError = error{Unexpected};

    /// Call RtlGenRandom() instead of CryptGetRandom() on Windows
    /// https://github.com/rust-lang-nursery/rand/issues/111
    /// https://bugzilla.mozilla.org/show_bug.cgi?id=504270
    pub fn RtlGenRandom(output: []u8) RtlGenRandomError!void {
        var total_read: usize = 0;
        var buff: []u8 = output[0..];
        const max_read_size: ULONG = maxInt(ULONG);

        while (total_read < output.len) {
            const to_read: ULONG = math.min(buff.len, max_read_size);

            if (advapi32.RtlGenRandom(buff.ptr, to_read) == 0) {
                return unexpectedError(kernel32.GetLastError());
            }

            total_read += to_read;
            buff = buff[to_read..];
        }
    }

    pub const WaitForSingleObjectError = error{
        WaitAbandoned,
        WaitTimeOut,
        Unexpected,
    };

    pub fn WaitForSingleObject(handle: HANDLE, milliseconds: DWORD) WaitForSingleObjectError!void {
        return WaitForSingleObjectEx(handle, milliseconds, false);
    }

    pub fn WaitForSingleObjectEx(handle: HANDLE, milliseconds: DWORD, alertable: bool) WaitForSingleObjectError!void {
        switch (kernel32.WaitForSingleObjectEx(handle, milliseconds, @boolToInt(alertable))) {
            WAIT_ABANDONED => return error.WaitAbandoned,
            WAIT_OBJECT_0 => return,
            WAIT_TIMEOUT => return error.WaitTimeOut,
            WAIT_FAILED => switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            },
            else => return error.Unexpected,
        }
    }

    pub fn WaitForMultipleObjectsEx(handles: []const HANDLE, waitAll: bool, milliseconds: DWORD, alertable: bool) !u32 {
        assert(handles.len < MAXIMUM_WAIT_OBJECTS);
        const nCount: DWORD = @intCast(DWORD, handles.len);
        switch (kernel32.WaitForMultipleObjectsEx(
            nCount,
            handles.ptr,
            @boolToInt(waitAll),
            milliseconds,
            @boolToInt(alertable),
        )) {
            WAIT_OBJECT_0...WAIT_OBJECT_0 + MAXIMUM_WAIT_OBJECTS => |n| {
                const handle_index = n - WAIT_OBJECT_0;
                assert(handle_index < nCount);
                return handle_index;
            },
            WAIT_ABANDONED_0...WAIT_ABANDONED_0 + MAXIMUM_WAIT_OBJECTS => |n| {
                const handle_index = n - WAIT_ABANDONED_0;
                assert(handle_index < nCount);
                return error.WaitAbandoned;
            },
            WAIT_TIMEOUT => return error.WaitTimeOut,
            WAIT_FAILED => switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            },
            else => return error.Unexpected,
        }
    }

    pub const CreateIoCompletionPortError = error{Unexpected};

    pub fn CreateIoCompletionPort(
        file_handle: HANDLE,
        existing_completion_port: ?HANDLE,
        completion_key: usize,
        concurrent_thread_count: DWORD,
    ) CreateIoCompletionPortError!HANDLE {
        const handle = kernel32.CreateIoCompletionPort(file_handle, existing_completion_port, completion_key, concurrent_thread_count) orelse {
            switch (kernel32.GetLastError()) {
                .INVALID_PARAMETER => unreachable,
                else => |err| return unexpectedError(err),
            }
        };
        return handle;
    }

    pub const PostQueuedCompletionStatusError = error{Unexpected};

    pub fn PostQueuedCompletionStatus(
        completion_port: HANDLE,
        bytes_transferred_count: DWORD,
        completion_key: usize,
        lpOverlapped: ?*OVERLAPPED,
    ) PostQueuedCompletionStatusError!void {
        if (kernel32.PostQueuedCompletionStatus(completion_port, bytes_transferred_count, completion_key, lpOverlapped) == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const GetQueuedCompletionStatusResult = enum {
        Normal,
        Aborted,
        Cancelled,
        EOF,
    };

    pub fn GetQueuedCompletionStatus(
        completion_port: HANDLE,
        bytes_transferred_count: *DWORD,
        lpCompletionKey: *usize,
        lpOverlapped: *?*OVERLAPPED,
        dwMilliseconds: DWORD,
    ) GetQueuedCompletionStatusResult {
        if (kernel32.GetQueuedCompletionStatus(
            completion_port,
            bytes_transferred_count,
            lpCompletionKey,
            lpOverlapped,
            dwMilliseconds,
        ) == FALSE) {
            switch (kernel32.GetLastError()) {
                .ABANDONED_WAIT_0 => return GetQueuedCompletionStatusResult.Aborted,
                .OPERATION_ABORTED => return GetQueuedCompletionStatusResult.Cancelled,
                .HANDLE_EOF => return GetQueuedCompletionStatusResult.EOF,
                else => |err| {
                    if (std.debug.runtime_safety) {
                        @setEvalBranchQuota(2500);
                        std.debug.panic("unexpected error: {}\n", .{err});
                    }
                },
            }
        }
        return GetQueuedCompletionStatusResult.Normal;
    }

    pub const GetQueuedCompletionStatusError = error{
        Aborted,
        Cancelled,
        EOF,
        Timeout,
    } || std.os.UnexpectedError;

    pub fn GetQueuedCompletionStatusEx(
        completion_port: HANDLE,
        completion_port_entries: []OVERLAPPED_ENTRY,
        timeout_ms: ?DWORD,
        alertable: bool,
    ) GetQueuedCompletionStatusError!u32 {
        var num_entries_removed: u32 = 0;

        const success = kernel32.GetQueuedCompletionStatusEx(
            completion_port,
            completion_port_entries.ptr,
            @intCast(ULONG, completion_port_entries.len),
            &num_entries_removed,
            timeout_ms orelse INFINITE,
            @boolToInt(alertable),
        );

        if (success == FALSE) {
            return switch (kernel32.GetLastError()) {
                .ABANDONED_WAIT_0 => error.Aborted,
                .OPERATION_ABORTED => error.Cancelled,
                .HANDLE_EOF => error.EOF,
                .IMEOUT => error.Timeout,
                else => |err| unexpectedError(err),
            };
        }

        return num_entries_removed;
    }

    pub fn CloseHandle(hObject: HANDLE) void {
        assert(ntdll.NtClose(hObject) == .SUCCESS);
    }

    pub fn FindClose(hFindFile: HANDLE) void {
        assert(kernel32.FindClose(hFindFile) != 0);
    }

    pub const ReadFileError = error{
        OperationAborted,
        BrokenPipe,
        Unexpected,
    };

    /// If buffer's length exceeds what a Windows DWORD integer can hold, it will be broken into
    /// multiple non-atomic reads.
    pub fn ReadFile(in_hFile: HANDLE, buffer: []u8, offset: ?u64, io_mode: std.io.ModeOverride) ReadFileError!usize {
        if (io_mode != .blocking) {
            const loop = std.event.Loop.instance.?;
            // TODO make getting the file position non-blocking

            const off = if (offset) |o| o else try SetFilePointerEx_CURRENT_get(in_hFile);
            var resume_node = std.event.Loop.ResumeNode.Basic{
                .base = .{
                    .id = .Basic,
                    .handle = @frame(),
                    .overlapped = OVERLAPPED{
                        .Internal = 0,
                        .InternalHigh = 0,
                        .DUMMYUNIONNAME = .{
                            .DUMMYSTRUCTNAME = .{
                                .Offset = @truncate(u32, off),
                                .OffsetHigh = @truncate(u32, off >> 32),
                            },
                        },
                        .hEvent = null,
                    },
                },
            };
            loop.beginOneEvent();
            suspend {
                // TODO handle buffer bigger than DWORD can hold

                _ = kernel32.ReadFile(in_hFile, buffer.ptr, @intCast(DWORD, buffer.len), null, &resume_node.base.overlapped);
            }
            var bytes_transferred: DWORD = undefined;
            if (kernel32.GetOverlappedResult(in_hFile, &resume_node.base.overlapped, &bytes_transferred, FALSE) == 0) {
                switch (kernel32.GetLastError()) {
                    .IO_PENDING => unreachable,
                    .OPERATION_ABORTED => return error.OperationAborted,
                    .BROKEN_PIPE => return error.BrokenPipe,
                    .HANDLE_EOF => return @as(usize, bytes_transferred),
                    else => |err| return unexpectedError(err),
                }
            }
            if (offset == null) {
                // TODO make setting the file position non-blocking

                const new_off = off + bytes_transferred;
                try SetFilePointerEx_CURRENT(in_hFile, @bitCast(i64, new_off));
            }
            return @as(usize, bytes_transferred);
        } else {
            while (true) {
                const want_read_count = @intCast(DWORD, math.min(@as(DWORD, maxInt(DWORD)), buffer.len));
                var amt_read: DWORD = undefined;
                var overlapped_data: OVERLAPPED = undefined;
                const overlapped: ?*OVERLAPPED = if (offset) |off| blk: {
                    overlapped_data = .{
                        .Internal = 0,
                        .InternalHigh = 0,
                        .DUMMYUNIONNAME = .{
                            .DUMMYSTRUCTNAME = .{
                                .Offset = @truncate(u32, off),
                                .OffsetHigh = @truncate(u32, off >> 32),
                            },
                        },
                        .hEvent = null,
                    };
                    break :blk &overlapped_data;
                } else null;
                if (kernel32.ReadFile(in_hFile, buffer.ptr, want_read_count, &amt_read, overlapped) == 0) {
                    switch (kernel32.GetLastError()) {
                        .OPERATION_ABORTED => continue,
                        .BROKEN_PIPE => return 0,
                        .HANDLE_EOF => return 0,
                        else => |err| return unexpectedError(err),
                    }
                }
                return amt_read;
            }
        }
    }

    pub const WriteFileError = error{
        SystemResources,
        OperationAborted,
        BrokenPipe,
        NotOpenForWriting,
        /// The process cannot access the file because another process has locked
        /// a portion of the file.
        LockViolation,
        Unexpected,
    };

    pub fn WriteFile(
        handle: HANDLE,
        bytes: []const u8,
        offset: ?u64,
        io_mode: std.io.ModeOverride,
    ) WriteFileError!usize {
        if (std.event.Loop.instance != null and io_mode != .blocking) {
            const loop = std.event.Loop.instance.?;
            // TODO make getting the file position non-blocking

            const off = if (offset) |o| o else try SetFilePointerEx_CURRENT_get(handle);
            var resume_node = std.event.Loop.ResumeNode.Basic{
                .base = .{
                    .id = .Basic,
                    .handle = @frame(),
                    .overlapped = OVERLAPPED{
                        .Internal = 0,
                        .InternalHigh = 0,
                        .DUMMYUNIONNAME = .{
                            .DUMMYSTRUCTNAME = .{
                                .Offset = @truncate(u32, off),
                                .OffsetHigh = @truncate(u32, off >> 32),
                            },
                        },
                        .hEvent = null,
                    },
                },
            };
            loop.beginOneEvent();
            suspend {
                const adjusted_len = math.cast(DWORD, bytes.len) orelse maxInt(DWORD);
                _ = kernel32.WriteFile(handle, bytes.ptr, adjusted_len, null, &resume_node.base.overlapped);
            }
            var bytes_transferred: DWORD = undefined;
            if (kernel32.GetOverlappedResult(handle, &resume_node.base.overlapped, &bytes_transferred, FALSE) == 0) {
                switch (kernel32.GetLastError()) {
                    .IO_PENDING => unreachable,
                    .INVALID_USER_BUFFER => return error.SystemResources,
                    .NOT_ENOUGH_MEMORY => return error.SystemResources,
                    .OPERATION_ABORTED => return error.OperationAborted,
                    .NOT_ENOUGH_QUOTA => return error.SystemResources,
                    .BROKEN_PIPE => return error.BrokenPipe,
                    else => |err| return unexpectedError(err),
                }
            }
            if (offset == null) {
                // TODO make setting the file position non-blocking

                const new_off = off + bytes_transferred;
                try SetFilePointerEx_CURRENT(handle, @bitCast(i64, new_off));
            }
            return bytes_transferred;
        } else {
            var bytes_written: DWORD = undefined;
            var overlapped_data: OVERLAPPED = undefined;
            const overlapped: ?*OVERLAPPED = if (offset) |off| blk: {
                overlapped_data = .{
                    .Internal = 0,
                    .InternalHigh = 0,
                    .DUMMYUNIONNAME = .{
                        .DUMMYSTRUCTNAME = .{
                            .Offset = @truncate(u32, off),
                            .OffsetHigh = @truncate(u32, off >> 32),
                        },
                    },
                    .hEvent = null,
                };
                break :blk &overlapped_data;
            } else null;
            const adjusted_len = math.cast(u32, bytes.len) orelse maxInt(u32);
            if (kernel32.WriteFile(handle, bytes.ptr, adjusted_len, &bytes_written, overlapped) == 0) {
                switch (kernel32.GetLastError()) {
                    .INVALID_USER_BUFFER => return error.SystemResources,
                    .NOT_ENOUGH_MEMORY => return error.SystemResources,
                    .OPERATION_ABORTED => return error.OperationAborted,
                    .NOT_ENOUGH_QUOTA => return error.SystemResources,
                    .IO_PENDING => unreachable,
                    .BROKEN_PIPE => return error.BrokenPipe,
                    .INVALID_HANDLE => return error.NotOpenForWriting,
                    .LOCK_VIOLATION => return error.LockViolation,
                    else => |err| return unexpectedError(err),
                }
            }
            return bytes_written;
        }
    }

    pub const SetCurrentDirectoryError = error{
        NameTooLong,
        InvalidUtf8,
        FileNotFound,
        NotDir,
        AccessDenied,
        NoDevice,
        BadPathName,
        Unexpected,
    };

    pub fn SetCurrentDirectory(path_name: []const u16) SetCurrentDirectoryError!void {
        const path_len_bytes = math.cast(u16, path_name.len * 2) orelse return error.NameTooLong;

        var nt_name = UNICODE_STRING{
            .Length = path_len_bytes,
            .MaximumLength = path_len_bytes,
            .Buffer = @intToPtr([*]u16, @ptrToInt(path_name.ptr)),
        };

        const rc = ntdll.RtlSetCurrentDirectory_U(&nt_name);
        switch (rc) {
            .SUCCESS => {},
            .OBJECT_NAME_INVALID => return error.BadPathName,
            .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
            .OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
            .NO_MEDIA_IN_DEVICE => return error.NoDevice,
            .INVALID_PARAMETER => unreachable,
            .ACCESS_DENIED => return error.AccessDenied,
            .OBJECT_PATH_SYNTAX_BAD => unreachable,
            .NOT_A_DIRECTORY => return error.NotDir,
            else => return unexpectedStatus(rc),
        }
    }

    pub const GetCurrentDirectoryError = error{
        NameTooLong,
        Unexpected,
    };

    /// The result is a slice of `buffer`, indexed from 0.
    pub fn GetCurrentDirectory(buffer: []u8) GetCurrentDirectoryError![]u8 {
        var utf16le_buf: [PATH_MAX_WIDE]u16 = undefined;
        const result = kernel32.GetCurrentDirectoryW(utf16le_buf.len, &utf16le_buf);
        if (result == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
        assert(result <= utf16le_buf.len);
        const utf16le_slice = utf16le_buf[0..result];
        // Trust that Windows gives us valid UTF-16LE.

        var end_index: usize = 0;
        var it = std.unicode.Utf16LeIterator.init(utf16le_slice);
        while (it.nextCodepoint() catch unreachable) |codepoint| {
            const seq_len = std.unicode.utf8CodepointSequenceLength(codepoint) catch unreachable;
            if (end_index + seq_len >= buffer.len)
                return error.NameTooLong;
            end_index += std.unicode.utf8Encode(codepoint, buffer[end_index..]) catch unreachable;
        }
        return buffer[0..end_index];
    }

    pub const CreateSymbolicLinkError = error{
        AccessDenied,
        PathAlreadyExists,
        FileNotFound,
        NameTooLong,
        NoDevice,
        Unexpected,
    };

    /// Needs either:
    /// - `SeCreateSymbolicLinkPrivilege` privilege
    /// or
    /// - Developer mode on Windows 10
    /// otherwise fails with `error.AccessDenied`. In which case `sym_link_path` may still
    /// be created on the file system but will lack reparse processing data applied to it.
    pub fn CreateSymbolicLink(
        dir: ?HANDLE,
        sym_link_path: []const u16,
        target_path: []const u16,
        is_directory: bool,
    ) CreateSymbolicLinkError!void {
        const SYMLINK_DATA = extern struct {
            ReparseTag: ULONG,
            ReparseDataLength: USHORT,
            Reserved: USHORT,
            SubstituteNameOffset: USHORT,
            SubstituteNameLength: USHORT,
            PrintNameOffset: USHORT,
            PrintNameLength: USHORT,
            Flags: ULONG,
        };

        const symlink_handle = OpenFile(sym_link_path, .{
            .access_mask = SYNCHRONIZE | GENERIC_READ | GENERIC_WRITE,
            .dir = dir,
            .creation = FILE_CREATE,
            .io_mode = .blocking,
            .filter = if (is_directory) .dir_only else .file_only,
        }) catch |err| switch (err) {
            error.IsDir => return error.PathAlreadyExists,
            error.NotDir => unreachable,
            error.WouldBlock => unreachable,
            error.PipeBusy => unreachable,
            else => |e| return e,
        };
        defer CloseHandle(symlink_handle);

        // prepare reparse data buffer

        var buffer: [MAXIMUM_REPARSE_DATA_BUFFER_SIZE]u8 = undefined;
        const buf_len = @sizeOf(SYMLINK_DATA) + target_path.len * 4;
        const header_len = @sizeOf(ULONG) + @sizeOf(USHORT) * 2;
        const symlink_data = SYMLINK_DATA{
            .ReparseTag = IO_REPARSE_TAG_SYMLINK,
            .ReparseDataLength = @intCast(u16, buf_len - header_len),
            .Reserved = 0,
            .SubstituteNameOffset = @intCast(u16, target_path.len * 2),
            .SubstituteNameLength = @intCast(u16, target_path.len * 2),
            .PrintNameOffset = 0,
            .PrintNameLength = @intCast(u16, target_path.len * 2),
            .Flags = if (dir) |_| SYMLINK_FLAG_RELATIVE else 0,
        };

        std.mem.copy(u8, buffer[0..], std.mem.asBytes(&symlink_data));
        @memcpy(buffer[@sizeOf(SYMLINK_DATA)..], @ptrCast([*]const u8, target_path), target_path.len * 2);
        const paths_start = @sizeOf(SYMLINK_DATA) + target_path.len * 2;
        @memcpy(buffer[paths_start..].ptr, @ptrCast([*]const u8, target_path), target_path.len * 2);
        _ = try DeviceIoControl(symlink_handle, FSCTL_SET_REPARSE_POINT, buffer[0..buf_len], null);
    }

    pub const ReadLinkError = error{
        FileNotFound,
        AccessDenied,
        Unexpected,
        NameTooLong,
        UnsupportedReparsePointType,
    };

    pub fn ReadLink(dir: ?HANDLE, sub_path_w: []const u16, out_buffer: []u8) ReadLinkError![]u8 {
        // Here, we use `NtCreateFile` to shave off one syscall if we were to use `OpenFile` wrapper.

        // With the latter, we'd need to call `NtCreateFile` twice, once for file symlink, and if that

        // failed, again for dir symlink. Omitting any mention of file/dir flags makes it possible

        // to open the symlink there and then.

        const path_len_bytes = math.cast(u16, sub_path_w.len * 2) orelse return error.NameTooLong;
        var nt_name = UNICODE_STRING{
            .Length = path_len_bytes,
            .MaximumLength = path_len_bytes,
            .Buffer = @intToPtr([*]u16, @ptrToInt(sub_path_w.ptr)),
        };
        var attr = OBJECT_ATTRIBUTES{
            .Length = @sizeOf(OBJECT_ATTRIBUTES),
            .RootDirectory = if (std.fs.path.isAbsoluteWindowsWTF16(sub_path_w)) null else dir,
            .Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.

            .ObjectName = &nt_name,
            .SecurityDescriptor = null,
            .SecurityQualityOfService = null,
        };
        var result_handle: HANDLE = undefined;
        var io: IO_STATUS_BLOCK = undefined;

        const rc = ntdll.NtCreateFile(
            &result_handle,
            FILE_READ_ATTRIBUTES,
            &attr,
            &io,
            null,
            FILE_ATTRIBUTE_NORMAL,
            FILE_SHARE_READ,
            FILE_OPEN,
            FILE_OPEN_REPARSE_POINT,
            null,
            0,
        );
        switch (rc) {
            .SUCCESS => {},
            .OBJECT_NAME_INVALID => unreachable,
            .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
            .OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
            .NO_MEDIA_IN_DEVICE => return error.FileNotFound,
            .INVALID_PARAMETER => unreachable,
            .SHARING_VIOLATION => return error.AccessDenied,
            .ACCESS_DENIED => return error.AccessDenied,
            .PIPE_BUSY => return error.AccessDenied,
            .OBJECT_PATH_SYNTAX_BAD => unreachable,
            .OBJECT_NAME_COLLISION => unreachable,
            .FILE_IS_A_DIRECTORY => unreachable,
            else => return unexpectedStatus(rc),
        }
        defer CloseHandle(result_handle);

        var reparse_buf: [MAXIMUM_REPARSE_DATA_BUFFER_SIZE]u8 align(@alignOf(REPARSE_DATA_BUFFER)) = undefined;
        _ = DeviceIoControl(result_handle, FSCTL_GET_REPARSE_POINT, null, reparse_buf[0..]) catch |err| switch (err) {
            error.AccessDenied => unreachable,
            else => |e| return e,
        };

        const reparse_struct = @ptrCast(*const REPARSE_DATA_BUFFER, @alignCast(@alignOf(REPARSE_DATA_BUFFER), &reparse_buf[0]));
        switch (reparse_struct.ReparseTag) {
            IO_REPARSE_TAG_SYMLINK => {
                const buf = @ptrCast(*const SYMBOLIC_LINK_REPARSE_BUFFER, @alignCast(@alignOf(SYMBOLIC_LINK_REPARSE_BUFFER), &reparse_struct.DataBuffer[0]));
                const offset = buf.SubstituteNameOffset >> 1;
                const len = buf.SubstituteNameLength >> 1;
                const path_buf = @as([*]const u16, &buf.PathBuffer);
                const is_relative = buf.Flags & SYMLINK_FLAG_RELATIVE != 0;
                return parseReadlinkPath(path_buf[offset .. offset + len], is_relative, out_buffer);
            },
            IO_REPARSE_TAG_MOUNT_POINT => {
                const buf = @ptrCast(*const MOUNT_POINT_REPARSE_BUFFER, @alignCast(@alignOf(MOUNT_POINT_REPARSE_BUFFER), &reparse_struct.DataBuffer[0]));
                const offset = buf.SubstituteNameOffset >> 1;
                const len = buf.SubstituteNameLength >> 1;
                const path_buf = @as([*]const u16, &buf.PathBuffer);
                return parseReadlinkPath(path_buf[offset .. offset + len], false, out_buffer);
            },
            else => |value| {
                std.debug.print("unsupported symlink type: {}", .{value});
                return error.UnsupportedReparsePointType;
            },
        }
    }

    fn parseReadlinkPath(path: []const u16, is_relative: bool, out_buffer: []u8) []u8 {
        const prefix = [_]u16{ '\\', '?', '?', '\\' };
        var start_index: usize = 0;
        if (!is_relative and std.mem.startsWith(u16, path, &prefix)) {
            start_index = prefix.len;
        }
        const out_len = std.unicode.utf16leToUtf8(out_buffer, path[start_index..]) catch unreachable;
        return out_buffer[0..out_len];
    }

    pub const DeleteFileError = error{
        FileNotFound,
        AccessDenied,
        NameTooLong,
        /// Also known as sharing violation.
        FileBusy,
        Unexpected,
        NotDir,
        IsDir,
    };

    pub const DeleteFileOptions = struct {
        dir: ?HANDLE,
        remove_dir: bool = false,
    };

    pub fn DeleteFile(sub_path_w: []const u16, options: DeleteFileOptions) DeleteFileError!void {
        const create_options_flags: ULONG = if (options.remove_dir)
            FILE_DELETE_ON_CLOSE | FILE_DIRECTORY_FILE | FILE_OPEN_REPARSE_POINT
        else
            FILE_DELETE_ON_CLOSE | FILE_NON_DIRECTORY_FILE | FILE_OPEN_REPARSE_POINT; // would we ever want to delete the target instead?

        const path_len_bytes = @intCast(u16, sub_path_w.len * 2);
        var nt_name = UNICODE_STRING{
            .Length = path_len_bytes,
            .MaximumLength = path_len_bytes,
            // The Windows API makes this mutable, but it will not mutate here.

            .Buffer = @intToPtr([*]u16, @ptrToInt(sub_path_w.ptr)),
        };

        if (sub_path_w[0] == '.' and sub_path_w[1] == 0) {
            // Windows does not recognize this, but it does work with empty string.

            nt_name.Length = 0;
        }
        if (sub_path_w[0] == '.' and sub_path_w[1] == '.' and sub_path_w[2] == 0) {
            // Can't remove the parent directory with an open handle.

            return error.FileBusy;
        }

        var attr = OBJECT_ATTRIBUTES{
            .Length = @sizeOf(OBJECT_ATTRIBUTES),
            .RootDirectory = if (std.fs.path.isAbsoluteWindowsWTF16(sub_path_w)) null else options.dir,
            .Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.

            .ObjectName = &nt_name,
            .SecurityDescriptor = null,
            .SecurityQualityOfService = null,
        };
        var io: IO_STATUS_BLOCK = undefined;
        var tmp_handle: HANDLE = undefined;
        var rc = ntdll.NtCreateFile(
            &tmp_handle,
            SYNCHRONIZE | DELETE,
            &attr,
            &io,
            null,
            0,
            FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
            FILE_OPEN,
            create_options_flags,
            null,
            0,
        );
        switch (rc) {
            .SUCCESS => return CloseHandle(tmp_handle),
            .OBJECT_NAME_INVALID => unreachable,
            .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
            .OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
            .INVALID_PARAMETER => unreachable,
            .FILE_IS_A_DIRECTORY => return error.IsDir,
            .NOT_A_DIRECTORY => return error.NotDir,
            .SHARING_VIOLATION => return error.FileBusy,
            .CANNOT_DELETE => return error.AccessDenied,
            else => return unexpectedStatus(rc),
        }
    }

    pub const MoveFileError = error{ FileNotFound, AccessDenied, Unexpected };

    pub fn MoveFileEx(old_path: []const u8, new_path: []const u8, flags: DWORD) MoveFileError!void {
        const old_path_w = try sliceToPrefixedFileW(old_path);
        const new_path_w = try sliceToPrefixedFileW(new_path);
        return MoveFileExW(old_path_w.span().ptr, new_path_w.span().ptr, flags);
    }

    pub fn MoveFileExW(old_path: [*:0]const u16, new_path: [*:0]const u16, flags: DWORD) MoveFileError!void {
        if (kernel32.MoveFileExW(old_path, new_path, flags) == 0) {
            switch (kernel32.GetLastError()) {
                .FILE_NOT_FOUND => return error.FileNotFound,
                .ACCESS_DENIED => return error.AccessDenied,
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const GetStdHandleError = error{
        NoStandardHandleAttached,
        Unexpected,
    };

    pub fn GetStdHandle(handle_id: DWORD) GetStdHandleError!HANDLE {
        const handle = kernel32.GetStdHandle(handle_id) orelse return error.NoStandardHandleAttached;
        if (handle == INVALID_HANDLE_VALUE) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
        return handle;
    }

    pub const SetFilePointerError = error{Unexpected};

    /// The SetFilePointerEx function with the `dwMoveMethod` parameter set to `FILE_BEGIN`.
    pub fn SetFilePointerEx_BEGIN(handle: HANDLE, offset: u64) SetFilePointerError!void {
        // "The starting point is zero or the beginning of the file. If [FILE_BEGIN]

        // is specified, then the liDistanceToMove parameter is interpreted as an unsigned value."

        // https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-setfilepointerex

        const ipos = @bitCast(LARGE_INTEGER, offset);
        if (kernel32.SetFilePointerEx(handle, ipos, null, FILE_BEGIN) == 0) {
            switch (kernel32.GetLastError()) {
                .INVALID_PARAMETER => unreachable,
                .INVALID_HANDLE => unreachable,
                else => |err| return unexpectedError(err),
            }
        }
    }

    /// The SetFilePointerEx function with the `dwMoveMethod` parameter set to `FILE_CURRENT`.
    pub fn SetFilePointerEx_CURRENT(handle: HANDLE, offset: i64) SetFilePointerError!void {
        if (kernel32.SetFilePointerEx(handle, offset, null, FILE_CURRENT) == 0) {
            switch (kernel32.GetLastError()) {
                .INVALID_PARAMETER => unreachable,
                .INVALID_HANDLE => unreachable,
                else => |err| return unexpectedError(err),
            }
        }
    }

    /// The SetFilePointerEx function with the `dwMoveMethod` parameter set to `FILE_END`.
    pub fn SetFilePointerEx_END(handle: HANDLE, offset: i64) SetFilePointerError!void {
        if (kernel32.SetFilePointerEx(handle, offset, null, FILE_END) == 0) {
            switch (kernel32.GetLastError()) {
                .INVALID_PARAMETER => unreachable,
                .INVALID_HANDLE => unreachable,
                else => |err| return unexpectedError(err),
            }
        }
    }

    /// The SetFilePointerEx function with parameters to get the current offset.
    pub fn SetFilePointerEx_CURRENT_get(handle: HANDLE) SetFilePointerError!u64 {
        var result: LARGE_INTEGER = undefined;
        if (kernel32.SetFilePointerEx(handle, 0, &result, FILE_CURRENT) == 0) {
            switch (kernel32.GetLastError()) {
                .INVALID_PARAMETER => unreachable,
                .INVALID_HANDLE => unreachable,
                else => |err| return unexpectedError(err),
            }
        }
        // Based on the docs for FILE_BEGIN, it seems that the returned signed integer

        // should be interpreted as an unsigned integer.

        return @bitCast(u64, result);
    }

    pub fn QueryObjectName(
        handle: HANDLE,
        out_buffer: []u16,
    ) ![]u16 {
        const out_buffer_aligned = mem.alignInSlice(out_buffer, @alignOf(OBJECT_NAME_INFORMATION)) orelse return error.NameTooLong;

        const info = @ptrCast(*OBJECT_NAME_INFORMATION, out_buffer_aligned);
        //buffer size is specified in bytes

        const out_buffer_len = std.math.cast(ULONG, out_buffer_aligned.len * 2) orelse std.math.maxInt(ULONG);
        //last argument would return the length required for full_buffer, not exposed here

        const rc = ntdll.NtQueryObject(handle, .ObjectNameInformation, info, out_buffer_len, null);
        switch (rc) {
            .SUCCESS => {
                // info.Name.Buffer from ObQueryNameString is documented to be null (and MaximumLength == 0)

                // if the object was "unnamed", not sure if this can happen for file handles

                if (info.Name.MaximumLength == 0) return error.Unexpected;
                // resulting string length is specified in bytes

                const path_length_unterminated = @divExact(info.Name.Length, 2);
                return info.Name.Buffer[0..path_length_unterminated];
            },
            .ACCESS_DENIED => return error.AccessDenied,
            .INVALID_HANDLE => return error.InvalidHandle,
            // triggered when the buffer is too small for the OBJECT_NAME_INFORMATION object (.INFO_LENGTH_MISMATCH),

            // or if the buffer is too small for the file path returned (.BUFFER_OVERFLOW, .BUFFER_TOO_SMALL)

            .INFO_LENGTH_MISMATCH, .BUFFER_OVERFLOW, .BUFFER_TOO_SMALL => return error.NameTooLong,
            else => |e| return unexpectedStatus(e),
        }
    }
    test "QueryObjectName" {
        if (builtin.os.tag != .windows)
            return;

        //any file will do; canonicalization works on NTFS junctions and symlinks, hardlinks remain separate paths.

        var tmp = std.testing.tmpDir(.{});
        defer tmp.cleanup();
        const handle = tmp.dir.fd;
        var out_buffer: [PATH_MAX_WIDE]u16 = undefined;

        var result_path = try QueryObjectName(handle, &out_buffer);
        const required_len_in_u16 = result_path.len + @divExact(@ptrToInt(result_path.ptr) - @ptrToInt(&out_buffer), 2) + 1;
        //insufficient size

        try std.testing.expectError(error.NameTooLong, QueryObjectName(handle, out_buffer[0 .. required_len_in_u16 - 1]));
        //exactly-sufficient size

        _ = try QueryObjectName(handle, out_buffer[0..required_len_in_u16]);
    }

    pub const GetFinalPathNameByHandleError = error{
        AccessDenied,
        BadPathName,
        FileNotFound,
        NameTooLong,
        Unexpected,
    };

    /// Specifies how to format volume path in the result of `GetFinalPathNameByHandle`.
    /// Defaults to DOS volume names.
    pub const GetFinalPathNameByHandleFormat = struct {
        volume_name: enum {
            /// Format as DOS volume name
            Dos,
            /// Format as NT volume name
            Nt,
        } = .Dos,
    };

    /// Returns canonical (normalized) path of handle.
    /// Use `GetFinalPathNameByHandleFormat` to specify whether the path is meant to include
    /// NT or DOS volume name (e.g., `\Device\HarddiskVolume0\foo.txt` versus `C:\foo.txt`).
    /// If DOS volume name format is selected, note that this function does *not* prepend
    /// `\\?\` prefix to the resultant path.
    pub fn GetFinalPathNameByHandle(
        hFile: HANDLE,
        fmt: GetFinalPathNameByHandleFormat,
        out_buffer: []u16,
    ) GetFinalPathNameByHandleError![]u16 {
        const final_path = QueryObjectName(hFile, out_buffer) catch |err| switch (err) {
            // we assume InvalidHandle is close enough to FileNotFound in semantics

            // to not further complicate the error set

            error.InvalidHandle => return error.FileNotFound,
            else => |e| return e,
        };

        switch (fmt.volume_name) {
            .Nt => {
                // the returned path is already in .Nt format

                return final_path;
            },
            .Dos => {
                // parse the string to separate volume path from file path

                const expected_prefix = std.unicode.utf8ToUtf16LeStringLiteral("\\Device\\");

                // TODO find out if a path can start with something besides `\Device\<volume name>`,

                // and if we need to handle it differently

                // (i.e. how to determine the start and end of the volume name in that case)

                if (!mem.eql(u16, expected_prefix, final_path[0..expected_prefix.len])) return error.Unexpected;

                const file_path_begin_index = mem.indexOfPos(u16, final_path, expected_prefix.len, &[_]u16{'\\'}) orelse unreachable;
                const volume_name_u16 = final_path[0..file_path_begin_index];
                const file_name_u16 = final_path[file_path_begin_index..];

                // Get DOS volume name. DOS volume names are actually symbolic link objects to the

                // actual NT volume. For example:

                // (NT) \Device\HarddiskVolume4 => (DOS) \DosDevices\C: == (DOS) C:

                const MIN_SIZE = @sizeOf(MOUNTMGR_MOUNT_POINT) + MAX_PATH;
                // We initialize the input buffer to all zeros for convenience since

                // `DeviceIoControl` with `IOCTL_MOUNTMGR_QUERY_POINTS` expects this.

                var input_buf: [MIN_SIZE]u8 align(@alignOf(MOUNTMGR_MOUNT_POINT)) = [_]u8{0} ** MIN_SIZE;
                var output_buf: [MIN_SIZE * 4]u8 align(@alignOf(MOUNTMGR_MOUNT_POINTS)) = undefined;

                // This surprising path is a filesystem path to the mount manager on Windows.

                // Source: https://stackoverflow.com/questions/3012828/using-ioctl-mountmgr-query-points

                const mgmt_path = "\\MountPointManager";
                const mgmt_path_u16 = sliceToPrefixedFileW(mgmt_path) catch unreachable;
                const mgmt_handle = OpenFile(mgmt_path_u16.span(), .{
                    .access_mask = SYNCHRONIZE,
                    .share_access = FILE_SHARE_READ | FILE_SHARE_WRITE,
                    .creation = FILE_OPEN,
                    .io_mode = .blocking,
                }) catch |err| switch (err) {
                    error.IsDir => unreachable,
                    error.NotDir => unreachable,
                    error.NoDevice => unreachable,
                    error.AccessDenied => unreachable,
                    error.PipeBusy => unreachable,
                    error.PathAlreadyExists => unreachable,
                    error.WouldBlock => unreachable,
                    else => |e| return e,
                };
                defer CloseHandle(mgmt_handle);

                var input_struct = @ptrCast(*MOUNTMGR_MOUNT_POINT, &input_buf[0]);
                input_struct.DeviceNameOffset = @sizeOf(MOUNTMGR_MOUNT_POINT);
                input_struct.DeviceNameLength = @intCast(USHORT, volume_name_u16.len * 2);
                @memcpy(input_buf[@sizeOf(MOUNTMGR_MOUNT_POINT)..], @ptrCast([*]const u8, volume_name_u16.ptr), volume_name_u16.len * 2);

                DeviceIoControl(mgmt_handle, IOCTL_MOUNTMGR_QUERY_POINTS, &input_buf, &output_buf) catch |err| switch (err) {
                    error.AccessDenied => unreachable,
                    else => |e| return e,
                };
                const mount_points_struct = @ptrCast(*const MOUNTMGR_MOUNT_POINTS, &output_buf[0]);

                const mount_points = @ptrCast(
                    [*]const MOUNTMGR_MOUNT_POINT,
                    &mount_points_struct.MountPoints[0],
                )[0..mount_points_struct.NumberOfMountPoints];

                for (mount_points) |mount_point| {
                    const symlink = @ptrCast(
                        [*]const u16,
                        @alignCast(@alignOf(u16), &output_buf[mount_point.SymbolicLinkNameOffset]),
                    )[0 .. mount_point.SymbolicLinkNameLength / 2];

                    // Look for `\DosDevices\` prefix. We don't really care if there are more than one symlinks

                    // with traditional DOS drive letters, so pick the first one available.

                    var prefix_buf = std.unicode.utf8ToUtf16LeStringLiteral("\\DosDevices\\");
                    const prefix = prefix_buf[0..prefix_buf.len];

                    if (mem.startsWith(u16, symlink, prefix)) {
                        const drive_letter = symlink[prefix.len..];

                        if (out_buffer.len < drive_letter.len + file_name_u16.len) return error.NameTooLong;

                        mem.copy(u16, out_buffer, drive_letter);
                        mem.copy(u16, out_buffer[drive_letter.len..], file_name_u16);
                        const total_len = drive_letter.len + file_name_u16.len;

                        // Validate that DOS does not contain any spurious nul bytes.

                        if (mem.indexOfScalar(u16, out_buffer[0..total_len], 0)) |_| {
                            return error.BadPathName;
                        }

                        return out_buffer[0..total_len];
                    }
                }

                // If we've ended up here, then something went wrong/is corrupted in the OS,

                // so error out!

                return error.FileNotFound;
            },
        }
    }

    test "GetFinalPathNameByHandle" {
        if (builtin.os.tag != .windows)
            return;

        //any file will do

        var tmp = std.testing.tmpDir(.{});
        defer tmp.cleanup();
        const handle = tmp.dir.fd;
        var buffer: [PATH_MAX_WIDE]u16 = undefined;

        //check with sufficient size

        const nt_path = try GetFinalPathNameByHandle(handle, .{ .volume_name = .Nt }, &buffer);
        _ = try GetFinalPathNameByHandle(handle, .{ .volume_name = .Dos }, &buffer);

        const required_len_in_u16 = nt_path.len + @divExact(@ptrToInt(nt_path.ptr) - @ptrToInt(&buffer), 2) + 1;
        //check with insufficient size

        try std.testing.expectError(error.NameTooLong, GetFinalPathNameByHandle(handle, .{ .volume_name = .Nt }, buffer[0 .. required_len_in_u16 - 1]));
        try std.testing.expectError(error.NameTooLong, GetFinalPathNameByHandle(handle, .{ .volume_name = .Dos }, buffer[0 .. required_len_in_u16 - 1]));

        //check with exactly-sufficient size

        _ = try GetFinalPathNameByHandle(handle, .{ .volume_name = .Nt }, buffer[0..required_len_in_u16]);
        _ = try GetFinalPathNameByHandle(handle, .{ .volume_name = .Dos }, buffer[0..required_len_in_u16]);
    }

    pub const QueryInformationFileError = error{Unexpected};

    pub fn QueryInformationFile(
        handle: HANDLE,
        info_class: FILE_INFORMATION_CLASS,
        out_buffer: []u8,
    ) QueryInformationFileError!void {
        var io: IO_STATUS_BLOCK = undefined;
        const len_bytes = std.math.cast(u32, out_buffer.len) orelse unreachable;
        const rc = ntdll.NtQueryInformationFile(handle, &io, out_buffer.ptr, len_bytes, info_class);
        switch (rc) {
            .SUCCESS => {},
            .INVALID_PARAMETER => unreachable,
            else => return unexpectedStatus(rc),
        }
    }

    pub const GetFileSizeError = error{Unexpected};

    pub fn GetFileSizeEx(hFile: HANDLE) GetFileSizeError!u64 {
        var file_size: LARGE_INTEGER = undefined;
        if (kernel32.GetFileSizeEx(hFile, &file_size) == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
        return @bitCast(u64, file_size);
    }

    pub const GetFileAttributesError = error{
        FileNotFound,
        PermissionDenied,
        Unexpected,
    };

    pub fn GetFileAttributes(filename: []const u8) GetFileAttributesError!DWORD {
        const filename_w = try sliceToPrefixedFileW(filename);
        return GetFileAttributesW(filename_w.span().ptr);
    }

    pub fn GetFileAttributesW(lpFileName: [*:0]const u16) GetFileAttributesError!DWORD {
        const rc = kernel32.GetFileAttributesW(lpFileName);
        if (rc == INVALID_FILE_ATTRIBUTES) {
            switch (kernel32.GetLastError()) {
                .FILE_NOT_FOUND => return error.FileNotFound,
                .PATH_NOT_FOUND => return error.FileNotFound,
                .ACCESS_DENIED => return error.PermissionDenied,
                else => |err| return unexpectedError(err),
            }
        }
        return rc;
    }

    pub fn WSAStartup(majorVersion: u8, minorVersion: u8) !ws2_32.WSADATA {
        var wsadata: ws2_32.WSADATA = undefined;
        return switch (ws2_32.WSAStartup((@as(WORD, minorVersion) << 8) | majorVersion, &wsadata)) {
            0 => wsadata,
            else => |err_int| switch (@intToEnum(ws2_32.WinsockError, @intCast(u16, err_int))) {
                .WSASYSNOTREADY => return error.SystemNotAvailable,
                .WSAVERNOTSUPPORTED => return error.VersionNotSupported,
                .WSAEINPROGRESS => return error.BlockingOperationInProgress,
                .WSAEPROCLIM => return error.ProcessFdQuotaExceeded,
                else => |err| return unexpectedWSAError(err),
            },
        };
    }

    pub fn WSACleanup() !void {
        return switch (ws2_32.WSACleanup()) {
            0 => {},
            ws2_32.SOCKET_ERROR => switch (ws2_32.WSAGetLastError()) {
                .WSANOTINITIALISED => return error.NotInitialized,
                .WSAENETDOWN => return error.NetworkNotAvailable,
                .WSAEINPROGRESS => return error.BlockingOperationInProgress,
                else => |err| return unexpectedWSAError(err),
            },
            else => unreachable,
        };
    }

    var wsa_startup_mutex: std.Thread.Mutex = .{};

    /// Microsoft requires WSAStartup to be called to initialize, or else
    /// WSASocketW will return WSANOTINITIALISED.
    /// Since this is a standard library, we do not have the luxury of
    /// putting initialization code anywhere, because we would not want
    /// to pay the cost of calling WSAStartup if there ended up being no
    /// networking. Also, if Zig code is used as a library, Zig is not in
    /// charge of the start code, and we couldn't put in any initialization
    /// code even if we wanted to.
    /// The documentation for WSAStartup mentions that there must be a
    /// matching WSACleanup call. It is not possible for the Zig Standard
    /// Library to honor this for the same reason - there is nowhere to put
    /// deinitialization code.
    /// So, API users of the zig std lib have two options:
    ///  * (recommended) The simple, cross-platform way: just call `WSASocketW`
    ///    and don't worry about it. Zig will call WSAStartup() in a thread-safe
    ///    manner and never deinitialize networking. This is ideal for an
    ///    application which has the capability to do networking.
    ///  * The getting-your-hands-dirty way: call `WSAStartup()` before doing
    ///    networking, so that the error handling code for WSANOTINITIALISED never
    ///    gets run, which then allows the application or library to call `WSACleanup()`.
    ///    This could make sense for a library, which has init and deinit
    ///    functions for the whole library's lifetime.
    pub fn WSASocketW(
        af: i32,
        socket_type: i32,
        protocol: i32,
        protocolInfo: ?*ws2_32.WSAPROTOCOL_INFOW,
        g: ws2_32.GROUP,
        dwFlags: DWORD,
    ) !ws2_32.SOCKET {
        var first = true;
        while (true) {
            const rc = ws2_32.WSASocketW(af, socket_type, protocol, protocolInfo, g, dwFlags);
            if (rc == ws2_32.INVALID_SOCKET) {
                switch (ws2_32.WSAGetLastError()) {
                    .WSAEAFNOSUPPORT => return error.AddressFamilyNotSupported,
                    .WSAEMFILE => return error.ProcessFdQuotaExceeded,
                    .WSAENOBUFS => return error.SystemResources,
                    .WSAEPROTONOSUPPORT => return error.ProtocolNotSupported,
                    .WSANOTINITIALISED => {
                        if (!first) return error.Unexpected;
                        first = false;

                        wsa_startup_mutex.lock();
                        defer wsa_startup_mutex.unlock();

                        // Here we could use a flag to prevent multiple threads to prevent

                        // multiple calls to WSAStartup, but it doesn't matter. We're globally

                        // leaking the resource intentionally, and the mutex already prevents

                        // data races within the WSAStartup function.

                        _ = WSAStartup(2, 2) catch |err| switch (err) {
                            error.SystemNotAvailable => return error.SystemResources,
                            error.VersionNotSupported => return error.Unexpected,
                            error.BlockingOperationInProgress => return error.Unexpected,
                            error.ProcessFdQuotaExceeded => return error.ProcessFdQuotaExceeded,
                            error.Unexpected => return error.Unexpected,
                        };
                        continue;
                    },
                    else => |err| return unexpectedWSAError(err),
                }
            }
            return rc;
        }
    }

    pub fn bind(s: ws2_32.SOCKET, name: *const ws2_32.sockaddr, namelen: ws2_32.socklen_t) i32 {
        return ws2_32.bind(s, name, @intCast(i32, namelen));
    }

    pub fn listen(s: ws2_32.SOCKET, backlog: u31) i32 {
        return ws2_32.listen(s, backlog);
    }

    pub fn closesocket(s: ws2_32.SOCKET) !void {
        switch (ws2_32.closesocket(s)) {
            0 => {},
            ws2_32.SOCKET_ERROR => switch (ws2_32.WSAGetLastError()) {
                else => |err| return unexpectedWSAError(err),
            },
            else => unreachable,
        }
    }

    pub fn accept(s: ws2_32.SOCKET, name: ?*ws2_32.sockaddr, namelen: ?*ws2_32.socklen_t) ws2_32.SOCKET {
        assert((name == null) == (namelen == null));
        return ws2_32.accept(s, name, @ptrCast(?*i32, namelen));
    }

    pub fn getsockname(s: ws2_32.SOCKET, name: *ws2_32.sockaddr, namelen: *ws2_32.socklen_t) i32 {
        return ws2_32.getsockname(s, name, @ptrCast(*i32, namelen));
    }

    pub fn getpeername(s: ws2_32.SOCKET, name: *ws2_32.sockaddr, namelen: *ws2_32.socklen_t) i32 {
        return ws2_32.getpeername(s, name, @ptrCast(*i32, namelen));
    }

    pub fn sendmsg(
        s: ws2_32.SOCKET,
        msg: *const ws2_32.WSAMSG,
        flags: u32,
    ) i32 {
        var bytes_send: DWORD = undefined;
        if (ws2_32.WSASendMsg(s, msg, flags, &bytes_send, null, null) == ws2_32.SOCKET_ERROR) {
            return ws2_32.SOCKET_ERROR;
        } else {
            return @as(i32, @intCast(u31, bytes_send));
        }
    }

    pub fn sendto(s: ws2_32.SOCKET, buf: [*]const u8, len: usize, flags: u32, to: ?*const ws2_32.sockaddr, to_len: ws2_32.socklen_t) i32 {
        var buffer = ws2_32.WSABUF{ .len = @truncate(u31, len), .buf = @intToPtr([*]u8, @ptrToInt(buf)) };
        var bytes_send: DWORD = undefined;
        if (ws2_32.WSASendTo(s, @ptrCast([*]ws2_32.WSABUF, &buffer), 1, &bytes_send, flags, to, @intCast(i32, to_len), null, null) == ws2_32.SOCKET_ERROR) {
            return ws2_32.SOCKET_ERROR;
        } else {
            return @as(i32, @intCast(u31, bytes_send));
        }
    }

    pub fn recvfrom(s: ws2_32.SOCKET, buf: [*]u8, len: usize, flags: u32, from: ?*ws2_32.sockaddr, from_len: ?*ws2_32.socklen_t) i32 {
        var buffer = ws2_32.WSABUF{ .len = @truncate(u31, len), .buf = buf };
        var bytes_received: DWORD = undefined;
        var flags_inout = flags;
        if (ws2_32.WSARecvFrom(s, @ptrCast([*]ws2_32.WSABUF, &buffer), 1, &bytes_received, &flags_inout, from, @ptrCast(?*i32, from_len), null, null) == ws2_32.SOCKET_ERROR) {
            return ws2_32.SOCKET_ERROR;
        } else {
            return @as(i32, @intCast(u31, bytes_received));
        }
    }

    pub fn poll(fds: [*]ws2_32.pollfd, n: c_ulong, timeout: i32) i32 {
        return ws2_32.WSAPoll(fds, n, timeout);
    }

    pub fn WSAIoctl(
        s: ws2_32.SOCKET,
        dwIoControlCode: DWORD,
        inBuffer: ?[]const u8,
        outBuffer: []u8,
        overlapped: ?*OVERLAPPED,
        completionRoutine: ?ws2_32.LPWSAOVERLAPPED_COMPLETION_ROUTINE,
    ) !DWORD {
        var bytes: DWORD = undefined;
        switch (ws2_32.WSAIoctl(
            s,
            dwIoControlCode,
            if (inBuffer) |i| i.ptr else null,
            if (inBuffer) |i| @intCast(DWORD, i.len) else 0,
            outBuffer.ptr,
            @intCast(DWORD, outBuffer.len),
            &bytes,
            overlapped,
            completionRoutine,
        )) {
            0 => {},
            ws2_32.SOCKET_ERROR => switch (ws2_32.WSAGetLastError()) {
                else => |err| return unexpectedWSAError(err),
            },
            else => unreachable,
        }
        return bytes;
    }

    const GetModuleFileNameError = error{Unexpected};

    pub fn GetModuleFileNameW(hModule: ?HMODULE, buf_ptr: [*]u16, buf_len: DWORD) GetModuleFileNameError![:0]u16 {
        const rc = kernel32.GetModuleFileNameW(hModule, buf_ptr, buf_len);
        if (rc == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
        return buf_ptr[0..rc :0];
    }

    pub const TerminateProcessError = error{Unexpected};

    pub fn TerminateProcess(hProcess: HANDLE, uExitCode: UINT) TerminateProcessError!void {
        if (kernel32.TerminateProcess(hProcess, uExitCode) == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const VirtualAllocError = error{Unexpected};

    pub fn VirtualAlloc(addr: ?LPVOID, size: usize, alloc_type: DWORD, flProtect: DWORD) VirtualAllocError!LPVOID {
        return kernel32.VirtualAlloc(addr, size, alloc_type, flProtect) orelse {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        };
    }

    pub fn VirtualFree(lpAddress: ?LPVOID, dwSize: usize, dwFreeType: DWORD) void {
        assert(kernel32.VirtualFree(lpAddress, dwSize, dwFreeType) != 0);
    }

    pub const VirtualQuerryError = error{Unexpected};

    pub fn VirtualQuery(lpAddress: ?LPVOID, lpBuffer: PMEMORY_BASIC_INFORMATION, dwLength: SIZE_T) VirtualQuerryError!SIZE_T {
        const rc = kernel32.VirtualQuery(lpAddress, lpBuffer, dwLength);
        if (rc == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }

        return rc;
    }

    pub const SetConsoleTextAttributeError = error{Unexpected};

    pub fn SetConsoleTextAttribute(hConsoleOutput: HANDLE, wAttributes: WORD) SetConsoleTextAttributeError!void {
        if (kernel32.SetConsoleTextAttribute(hConsoleOutput, wAttributes) == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub fn SetConsoleCtrlHandler(handler_routine: ?HANDLER_ROUTINE, add: bool) !void {
        const success = kernel32.SetConsoleCtrlHandler(
            handler_routine,
            if (add) TRUE else FALSE,
        );

        if (success == FALSE) {
            return switch (kernel32.GetLastError()) {
                else => |err| unexpectedError(err),
            };
        }
    }

    pub fn SetFileCompletionNotificationModes(handle: HANDLE, flags: UCHAR) !void {
        const success = kernel32.SetFileCompletionNotificationModes(handle, flags);
        if (success == FALSE) {
            return switch (kernel32.GetLastError()) {
                else => |err| unexpectedError(err),
            };
        }
    }

    pub const GetEnvironmentStringsError = error{OutOfMemory};

    pub fn GetEnvironmentStringsW() GetEnvironmentStringsError![*:0]u16 {
        return kernel32.GetEnvironmentStringsW() orelse return error.OutOfMemory;
    }

    pub fn FreeEnvironmentStringsW(penv: [*:0]u16) void {
        assert(kernel32.FreeEnvironmentStringsW(penv) != 0);
    }

    pub const GetEnvironmentVariableError = error{
        EnvironmentVariableNotFound,
        Unexpected,
    };

    pub fn GetEnvironmentVariableW(lpName: LPWSTR, lpBuffer: [*]u16, nSize: DWORD) GetEnvironmentVariableError!DWORD {
        const rc = kernel32.GetEnvironmentVariableW(lpName, lpBuffer, nSize);
        if (rc == 0) {
            switch (kernel32.GetLastError()) {
                .ENVVAR_NOT_FOUND => return error.EnvironmentVariableNotFound,
                else => |err| return unexpectedError(err),
            }
        }
        return rc;
    }

    pub const CreateProcessError = error{
        FileNotFound,
        AccessDenied,
        InvalidName,
        NameTooLong,
        Unexpected,
    };

    pub fn CreateProcessW(
        lpApplicationName: ?LPWSTR,
        lpCommandLine: LPWSTR,
        lpProcessAttributes: ?*SECURITY_ATTRIBUTES,
        lpThreadAttributes: ?*SECURITY_ATTRIBUTES,
        bInheritHandles: BOOL,
        dwCreationFlags: DWORD,
        lpEnvironment: ?*anyopaque,
        lpCurrentDirectory: ?LPWSTR,
        lpStartupInfo: *STARTUPINFOW,
        lpProcessInformation: *PROCESS_INFORMATION,
    ) CreateProcessError!void {
        if (kernel32.CreateProcessW(
            lpApplicationName,
            lpCommandLine,
            lpProcessAttributes,
            lpThreadAttributes,
            bInheritHandles,
            dwCreationFlags,
            lpEnvironment,
            lpCurrentDirectory,
            lpStartupInfo,
            lpProcessInformation,
        ) == 0) {
            switch (kernel32.GetLastError()) {
                .FILE_NOT_FOUND => return error.FileNotFound,
                .PATH_NOT_FOUND => return error.FileNotFound,
                .ACCESS_DENIED => return error.AccessDenied,
                .INVALID_PARAMETER => unreachable,
                .INVALID_NAME => return error.InvalidName,
                .FILENAME_EXCED_RANGE => return error.NameTooLong,
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const LoadLibraryError = error{
        FileNotFound,
        Unexpected,
    };

    pub fn LoadLibraryW(lpLibFileName: [*:0]const u16) LoadLibraryError!HMODULE {
        return kernel32.LoadLibraryW(lpLibFileName) orelse {
            switch (kernel32.GetLastError()) {
                .FILE_NOT_FOUND => return error.FileNotFound,
                .PATH_NOT_FOUND => return error.FileNotFound,
                .MOD_NOT_FOUND => return error.FileNotFound,
                else => |err| return unexpectedError(err),
            }
        };
    }

    pub fn FreeLibrary(hModule: HMODULE) void {
        assert(kernel32.FreeLibrary(hModule) != 0);
    }

    pub fn QueryPerformanceFrequency() u64 {
        // "On systems that run Windows XP or later, the function will always succeed"

        // https://docs.microsoft.com/en-us/windows/desktop/api/profileapi/nf-profileapi-queryperformancefrequency

        var result: LARGE_INTEGER = undefined;
        assert(kernel32.QueryPerformanceFrequency(&result) != 0);
        // The kernel treats this integer as unsigned.

        return @bitCast(u64, result);
    }

    pub fn QueryPerformanceCounter() u64 {
        // "On systems that run Windows XP or later, the function will always succeed"

        // https://docs.microsoft.com/en-us/windows/desktop/api/profileapi/nf-profileapi-queryperformancecounter

        var result: LARGE_INTEGER = undefined;
        assert(kernel32.QueryPerformanceCounter(&result) != 0);
        // The kernel treats this integer as unsigned.

        return @bitCast(u64, result);
    }

    pub fn InitOnceExecuteOnce(InitOnce: *INIT_ONCE, InitFn: INIT_ONCE_FN, Parameter: ?*anyopaque, Context: ?*anyopaque) void {
        assert(kernel32.InitOnceExecuteOnce(InitOnce, InitFn, Parameter, Context) != 0);
    }

    pub fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: *anyopaque) void {
        assert(kernel32.HeapFree(hHeap, dwFlags, lpMem) != 0);
    }

    pub fn HeapDestroy(hHeap: HANDLE) void {
        assert(kernel32.HeapDestroy(hHeap) != 0);
    }

    pub fn LocalFree(hMem: HLOCAL) void {
        assert(kernel32.LocalFree(hMem) == null);
    }

    pub const GetFileInformationByHandleError = error{Unexpected};

    pub fn GetFileInformationByHandle(
        hFile: HANDLE,
    ) GetFileInformationByHandleError!BY_HANDLE_FILE_INFORMATION {
        var info: BY_HANDLE_FILE_INFORMATION = undefined;
        const rc = ntdll.GetFileInformationByHandle(hFile, &info);
        if (rc == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
        return info;
    }

    pub const SetFileTimeError = error{Unexpected};

    pub fn SetFileTime(
        hFile: HANDLE,
        lpCreationTime: ?*const FILETIME,
        lpLastAccessTime: ?*const FILETIME,
        lpLastWriteTime: ?*const FILETIME,
    ) SetFileTimeError!void {
        const rc = kernel32.SetFileTime(hFile, lpCreationTime, lpLastAccessTime, lpLastWriteTime);
        if (rc == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
    }

    pub const LockFileError = error{
        SystemResources,
        WouldBlock,
    } || std.os.UnexpectedError;

    pub fn LockFile(
        FileHandle: HANDLE,
        Event: ?HANDLE,
        ApcRoutine: ?*IO_APC_ROUTINE,
        ApcContext: ?*anyopaque,
        IoStatusBlock: *IO_STATUS_BLOCK,
        ByteOffset: *const LARGE_INTEGER,
        Length: *const LARGE_INTEGER,
        Key: ?*ULONG,
        FailImmediately: BOOLEAN,
        ExclusiveLock: BOOLEAN,
    ) !void {
        const rc = ntdll.NtLockFile(
            FileHandle,
            Event,
            ApcRoutine,
            ApcContext,
            IoStatusBlock,
            ByteOffset,
            Length,
            Key,
            FailImmediately,
            ExclusiveLock,
        );
        switch (rc) {
            .SUCCESS => return,
            .INSUFFICIENT_RESOURCES => return error.SystemResources,
            .LOCK_NOT_GRANTED => return error.WouldBlock,
            .ACCESS_VIOLATION => unreachable, // bad io_status_block pointer

            else => return unexpectedStatus(rc),
        }
    }

    pub const UnlockFileError = error{
        RangeNotLocked,
    } || std.os.UnexpectedError;

    pub fn UnlockFile(
        FileHandle: HANDLE,
        IoStatusBlock: *IO_STATUS_BLOCK,
        ByteOffset: *const LARGE_INTEGER,
        Length: *const LARGE_INTEGER,
        Key: ?*ULONG,
    ) !void {
        const rc = ntdll.NtUnlockFile(FileHandle, IoStatusBlock, ByteOffset, Length, Key);
        switch (rc) {
            .SUCCESS => return,
            .RANGE_NOT_LOCKED => return error.RangeNotLocked,
            .ACCESS_VIOLATION => unreachable, // bad io_status_block pointer

            else => return unexpectedStatus(rc),
        }
    }

    pub fn teb() *TEB {
        return switch (native_arch) {
            .i386 => asm volatile (
                \\ movl %%fs:0x18, %[ptr]

                : [ptr] "=r" (-> *TEB),
            ),
            .x86_64 => asm volatile (
                \\ movq %%gs:0x30, %[ptr]

                : [ptr] "=r" (-> *TEB),
            ),
            .aarch64 => asm volatile (
                \\ mov %[ptr], x18

                : [ptr] "=r" (-> *TEB),
            ),
            else => @compileError("unsupported arch"),
        };
    }

    pub fn peb() *PEB {
        return teb().ProcessEnvironmentBlock;
    }

    /// A file time is a 64-bit value that represents the number of 100-nanosecond
    /// intervals that have elapsed since 12:00 A.M. January 1, 1601 Coordinated
    /// Universal Time (UTC).
    /// This function returns the number of nanoseconds since the canonical epoch,
    /// which is the POSIX one (Jan 01, 1970 AD).
    pub fn fromSysTime(hns: i64) i128 {
        const adjusted_epoch: i128 = hns + std.time.epoch.windows * (std.time.ns_per_s / 100);
        return adjusted_epoch * 100;
    }

    pub fn toSysTime(ns: i128) i64 {
        const hns = @divFloor(ns, 100);
        return @intCast(i64, hns) - std.time.epoch.windows * (std.time.ns_per_s / 100);
    }

    pub fn fileTimeToNanoSeconds(ft: FILETIME) i128 {
        const hns = (@as(i64, ft.dwHighDateTime) << 32) | ft.dwLowDateTime;
        return fromSysTime(hns);
    }

    /// Converts a number of nanoseconds since the POSIX epoch to a Windows FILETIME.
    pub fn nanoSecondsToFileTime(ns: i128) FILETIME {
        const adjusted = @bitCast(u64, toSysTime(ns));
        return FILETIME{
            .dwHighDateTime = @truncate(u32, adjusted >> 32),
            .dwLowDateTime = @truncate(u32, adjusted),
        };
    }

    pub const PathSpace = struct {
        data: [PATH_MAX_WIDE:0]u16,
        len: usize,

        pub fn span(self: *const PathSpace) [:0]const u16 {
            return self.data[0..self.len :0];
        }
    };

    /// The error type for `removeDotDirsSanitized`
    pub const RemoveDotDirsError = error{TooManyParentDirs};

    /// Removes '.' and '..' path components from a "sanitized relative path".
    /// A "sanitized path" is one where:
    ///    1) all forward slashes have been replaced with back slashes
    ///    2) all repeating back slashes have been collapsed
    ///    3) the path is a relative one (does not start with a back slash)
    pub fn removeDotDirsSanitized(comptime T: type, path: []T) RemoveDotDirsError!usize {
        std.debug.assert(path.len == 0 or path[0] != '\\');

        var write_idx: usize = 0;
        var read_idx: usize = 0;
        while (read_idx < path.len) {
            if (path[read_idx] == '.') {
                if (read_idx + 1 == path.len)
                    return write_idx;

                const after_dot = path[read_idx + 1];
                if (after_dot == '\\') {
                    read_idx += 2;
                    continue;
                }
                if (after_dot == '.' and (read_idx + 2 == path.len or path[read_idx + 2] == '\\')) {
                    if (write_idx == 0) return error.TooManyParentDirs;
                    std.debug.assert(write_idx >= 2);
                    write_idx -= 1;
                    while (true) {
                        write_idx -= 1;
                        if (write_idx == 0) break;
                        if (path[write_idx] == '\\') {
                            write_idx += 1;
                            break;
                        }
                    }
                    if (read_idx + 2 == path.len)
                        return write_idx;
                    read_idx += 3;
                    continue;
                }
            }

            // skip to the next path separator

            while (true) : (read_idx += 1) {
                if (read_idx == path.len)
                    return write_idx;
                path[write_idx] = path[read_idx];
                write_idx += 1;
                if (path[read_idx] == '\\')
                    break;
            }
            read_idx += 1;
        }
        return write_idx;
    }

    /// Normalizes a Windows path with the following steps:
    ///     1) convert all forward slashes to back slashes
    ///     2) collapse duplicate back slashes
    ///     3) remove '.' and '..' directory parts
    /// Returns the length of the new path.
    pub fn normalizePath(comptime T: type, path: []T) RemoveDotDirsError!usize {
        mem.replaceScalar(T, path, '/', '\\');
        const new_len = mem.collapseRepeatsLen(T, path, '\\');

        const prefix_len: usize = init: {
            if (new_len >= 1 and path[0] == '\\') break :init 1;
            if (new_len >= 2 and path[1] == ':')
                break :init if (new_len >= 3 and path[2] == '\\') @as(usize, 3) else @as(usize, 2);
            break :init 0;
        };

        return prefix_len + try removeDotDirsSanitized(T, path[prefix_len..new_len]);
    }

    /// Same as `sliceToPrefixedFileW` but accepts a pointer
    /// to a null-terminated path.
    pub fn cStrToPrefixedFileW(s: [*:0]const u8) !PathSpace {
        return sliceToPrefixedFileW(mem.sliceTo(s, 0));
    }

    /// Converts the path `s` to WTF16, null-terminated. If the path is absolute,
    /// it will get NT-style prefix `\??\` prepended automatically.
    pub fn sliceToPrefixedFileW(s: []const u8) !PathSpace {
        // TODO https://github.com/ziglang/zig/issues/2765

        var path_space: PathSpace = undefined;
        const prefix = "\\??\\";
        const prefix_index: usize = if (mem.startsWith(u8, s, prefix)) prefix.len else 0;
        for (s[prefix_index..]) |byte| {
            switch (byte) {
                '*', '?', '"', '<', '>', '|' => return error.BadPathName,
                else => {},
            }
        }
        const prefix_u16 = [_]u16{ '\\', '?', '?', '\\' };
        const start_index = if (prefix_index > 0 or !std.fs.path.isAbsolute(s)) 0 else blk: {
            mem.copy(u16, path_space.data[0..], prefix_u16[0..]);
            break :blk prefix_u16.len;
        };
        path_space.len = start_index + try std.unicode.utf8ToUtf16Le(path_space.data[start_index..], s);
        if (path_space.len > path_space.data.len) return error.NameTooLong;
        path_space.len = start_index + (normalizePath(u16, path_space.data[start_index..path_space.len]) catch |err| switch (err) {
            error.TooManyParentDirs => {
                if (!std.fs.path.isAbsolute(s)) {
                    var temp_path: PathSpace = undefined;
                    temp_path.len = try std.unicode.utf8ToUtf16Le(&temp_path.data, s);
                    std.debug.assert(temp_path.len == path_space.len);
                    temp_path.data[path_space.len] = 0;
                    path_space.len = prefix_u16.len + try getFullPathNameW(&temp_path.data, path_space.data[prefix_u16.len..]);
                    mem.copy(u16, &path_space.data, &prefix_u16);
                    std.debug.assert(path_space.data[path_space.len] == 0);
                    return path_space;
                }
                return error.BadPathName;
            },
        });
        path_space.data[path_space.len] = 0;
        return path_space;
    }

    fn getFullPathNameW(path: [*:0]const u16, out: []u16) !usize {
        const result = kernel32.GetFullPathNameW(path, @intCast(u32, out.len), std.meta.assumeSentinel(out.ptr, 0), null);
        if (result == 0) {
            switch (kernel32.GetLastError()) {
                else => |err| return unexpectedError(err),
            }
        }
        return result;
    }

    /// Assumes an absolute path.
    pub fn wToPrefixedFileW(s: []const u16) !PathSpace {
        // TODO https://github.com/ziglang/zig/issues/2765

        var path_space: PathSpace = undefined;

        const start_index = if (mem.startsWith(u16, s, &[_]u16{ '\\', '?' })) 0 else blk: {
            const prefix = [_]u16{ '\\', '?', '?', '\\' };
            mem.copy(u16, path_space.data[0..], &prefix);
            break :blk prefix.len;
        };
        path_space.len = start_index + s.len;
        if (path_space.len > path_space.data.len) return error.NameTooLong;
        mem.copy(u16, path_space.data[start_index..], s);
        // > File I/O functions in the Windows API convert "/" to "\" as part of

        // > converting the name to an NT-style name, except when using the "\\?\"

        // > prefix as detailed in the following sections.

        // from https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file#maximum-path-length-limitation

        // Because we want the larger maximum path length for absolute paths, we

        // convert forward slashes to backward slashes here.

        for (path_space.data[0..path_space.len]) |*elem| {
            if (elem.* == '/') {
                elem.* = '\\';
            }
        }
        path_space.data[path_space.len] = 0;
        return path_space;
    }

    inline fn MAKELANGID(p: c_ushort, s: c_ushort) LANGID {
        return (s << 10) | p;
    }

    /// Loads a Winsock extension function in runtime specified by a GUID.
    pub fn loadWinsockExtensionFunction(comptime T: type, sock: ws2_32.SOCKET, guid: GUID) !T {
        var function: T = undefined;
        var num_bytes: DWORD = undefined;

        const rc = ws2_32.WSAIoctl(
            sock,
            ws2_32.SIO_GET_EXTENSION_FUNCTION_POINTER,
            @ptrCast(*const anyopaque, &guid),
            @sizeOf(GUID),
            &function,
            @sizeOf(T),
            &num_bytes,
            null,
            null,
        );

        if (rc == ws2_32.SOCKET_ERROR) {
            return switch (ws2_32.WSAGetLastError()) {
                .WSAEOPNOTSUPP => error.OperationNotSupported,
                .WSAENOTSOCK => error.FileDescriptorNotASocket,
                else => |err| unexpectedWSAError(err),
            };
        }

        if (num_bytes != @sizeOf(T)) {
            return error.ShortRead;
        }

        return function;
    }

    /// Call this when you made a windows DLL call or something that does SetLastError
    /// and you get an unexpected error.
    pub fn unexpectedError(err: Win32Error) std.os.UnexpectedError {
        if (std.os.unexpected_error_tracing) {
            // 614 is the length of the longest windows error desciption

            var buf_wstr: [614]WCHAR = undefined;
            var buf_utf8: [614]u8 = undefined;
            const len = kernel32.FormatMessageW(
                FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                null,
                err,
                MAKELANGID(LANG.NEUTRAL, SUBLANG.DEFAULT),
                &buf_wstr,
                buf_wstr.len,
                null,
            );
            _ = std.unicode.utf16leToUtf8(&buf_utf8, buf_wstr[0..len]) catch unreachable;
            std.debug.print("error.Unexpected: GetLastError({}): {s}\n", .{ @enumToInt(err), buf_utf8[0..len] });
            std.debug.dumpCurrentStackTrace(null);
        }
        return error.Unexpected;
    }

    pub fn unexpectedWSAError(err: ws2_32.WinsockError) std.os.UnexpectedError {
        return unexpectedError(@intToEnum(Win32Error, @enumToInt(err)));
    }

    /// Call this when you made a windows NtDll call
    /// and you get an unexpected status.
    pub fn unexpectedStatus(status: NTSTATUS) std.os.UnexpectedError {
        if (std.os.unexpected_error_tracing) {
            std.debug.print("error.Unexpected NTSTATUS=0x{x}\n", .{@enumToInt(status)});
            std.debug.dumpCurrentStackTrace(null);
        }
        return error.Unexpected;
    }

    pub const Win32Error = @import("windows/win32error.zig").Win32Error;
    pub const NTSTATUS = @import("windows/ntstatus.zig").NTSTATUS;
    pub const LANG = @import("windows/lang.zig");
    pub const SUBLANG = @import("windows/sublang.zig");

    /// The standard input device. Initially, this is the console input buffer, CONIN$.
    pub const STD_INPUT_HANDLE = maxInt(DWORD) - 10 + 1;

    /// The standard output device. Initially, this is the active console screen buffer, CONOUT$.
    pub const STD_OUTPUT_HANDLE = maxInt(DWORD) - 11 + 1;

    /// The standard error device. Initially, this is the active console screen buffer, CONOUT$.
    pub const STD_ERROR_HANDLE = maxInt(DWORD) - 12 + 1;

    pub const WINAPI: std.builtin.CallingConvention = if (native_arch == .i386)
        .Stdcall
    else
        .C;

    pub const BOOL = c_int;
    pub const BOOLEAN = BYTE;
    pub const BYTE = u8;
    pub const CHAR = u8;
    pub const UCHAR = u8;
    pub const FLOAT = f32;
    pub const HANDLE = *anyopaque;
    pub const HCRYPTPROV = ULONG_PTR;
    pub const ATOM = u16;
    pub const HBRUSH = *opaque {};
    pub const HCURSOR = *opaque {};
    pub const HICON = *opaque {};
    pub const HINSTANCE = *opaque {};
    pub const HMENU = *opaque {};
    pub const HMODULE = *opaque {};
    pub const HWND = *opaque {};
    pub const HDC = *opaque {};
    pub const HGLRC = *opaque {};
    pub const FARPROC = *opaque {};
    pub const INT = c_int;
    pub const LPCSTR = [*:0]const CHAR;
    pub const LPCVOID = *const anyopaque;
    pub const LPSTR = [*:0]CHAR;
    pub const LPVOID = *anyopaque;
    pub const LPWSTR = [*:0]WCHAR;
    pub const LPCWSTR = [*:0]const WCHAR;
    pub const PVOID = *anyopaque;
    pub const PWSTR = [*:0]WCHAR;
    pub const PCWSTR = [*:0]const WCHAR;
    pub const SIZE_T = usize;
    pub const UINT = c_uint;
    pub const ULONG_PTR = usize;
    pub const LONG_PTR = isize;
    pub const DWORD_PTR = ULONG_PTR;
    pub const WCHAR = u16;
    pub const WORD = u16;
    pub const DWORD = u32;
    pub const DWORD64 = u64;
    pub const LARGE_INTEGER = i64;
    pub const ULARGE_INTEGER = u64;
    pub const USHORT = u16;
    pub const SHORT = i16;
    pub const ULONG = u32;
    pub const LONG = i32;
    pub const ULONG64 = u64;
    pub const ULONGLONG = u64;
    pub const LONGLONG = i64;
    pub const HLOCAL = HANDLE;
    pub const LANGID = c_ushort;

    pub const WPARAM = usize;
    pub const LPARAM = LONG_PTR;
    pub const LRESULT = LONG_PTR;

    pub const va_list = *opaque {};

    pub const TRUE = 1;
    pub const FALSE = 0;

    pub const DEVICE_TYPE = ULONG;
    pub const FILE_DEVICE_BEEP: DEVICE_TYPE = 0x0001;
    pub const FILE_DEVICE_CD_ROM: DEVICE_TYPE = 0x0002;
    pub const FILE_DEVICE_CD_ROM_FILE_SYSTEM: DEVICE_TYPE = 0x0003;
    pub const FILE_DEVICE_CONTROLLER: DEVICE_TYPE = 0x0004;
    pub const FILE_DEVICE_DATALINK: DEVICE_TYPE = 0x0005;
    pub const FILE_DEVICE_DFS: DEVICE_TYPE = 0x0006;
    pub const FILE_DEVICE_DISK: DEVICE_TYPE = 0x0007;
    pub const FILE_DEVICE_DISK_FILE_SYSTEM: DEVICE_TYPE = 0x0008;
    pub const FILE_DEVICE_FILE_SYSTEM: DEVICE_TYPE = 0x0009;
    pub const FILE_DEVICE_INPORT_PORT: DEVICE_TYPE = 0x000a;
    pub const FILE_DEVICE_KEYBOARD: DEVICE_TYPE = 0x000b;
    pub const FILE_DEVICE_MAILSLOT: DEVICE_TYPE = 0x000c;
    pub const FILE_DEVICE_MIDI_IN: DEVICE_TYPE = 0x000d;
    pub const FILE_DEVICE_MIDI_OUT: DEVICE_TYPE = 0x000e;
    pub const FILE_DEVICE_MOUSE: DEVICE_TYPE = 0x000f;
    pub const FILE_DEVICE_MULTI_UNC_PROVIDER: DEVICE_TYPE = 0x0010;
    pub const FILE_DEVICE_NAMED_PIPE: DEVICE_TYPE = 0x0011;
    pub const FILE_DEVICE_NETWORK: DEVICE_TYPE = 0x0012;
    pub const FILE_DEVICE_NETWORK_BROWSER: DEVICE_TYPE = 0x0013;
    pub const FILE_DEVICE_NETWORK_FILE_SYSTEM: DEVICE_TYPE = 0x0014;
    pub const FILE_DEVICE_NULL: DEVICE_TYPE = 0x0015;
    pub const FILE_DEVICE_PARALLEL_PORT: DEVICE_TYPE = 0x0016;
    pub const FILE_DEVICE_PHYSICAL_NETCARD: DEVICE_TYPE = 0x0017;
    pub const FILE_DEVICE_PRINTER: DEVICE_TYPE = 0x0018;
    pub const FILE_DEVICE_SCANNER: DEVICE_TYPE = 0x0019;
    pub const FILE_DEVICE_SERIAL_MOUSE_PORT: DEVICE_TYPE = 0x001a;
    pub const FILE_DEVICE_SERIAL_PORT: DEVICE_TYPE = 0x001b;
    pub const FILE_DEVICE_SCREEN: DEVICE_TYPE = 0x001c;
    pub const FILE_DEVICE_SOUND: DEVICE_TYPE = 0x001d;
    pub const FILE_DEVICE_STREAMS: DEVICE_TYPE = 0x001e;
    pub const FILE_DEVICE_TAPE: DEVICE_TYPE = 0x001f;
    pub const FILE_DEVICE_TAPE_FILE_SYSTEM: DEVICE_TYPE = 0x0020;
    pub const FILE_DEVICE_TRANSPORT: DEVICE_TYPE = 0x0021;
    pub const FILE_DEVICE_UNKNOWN: DEVICE_TYPE = 0x0022;
    pub const FILE_DEVICE_VIDEO: DEVICE_TYPE = 0x0023;
    pub const FILE_DEVICE_VIRTUAL_DISK: DEVICE_TYPE = 0x0024;
    pub const FILE_DEVICE_WAVE_IN: DEVICE_TYPE = 0x0025;
    pub const FILE_DEVICE_WAVE_OUT: DEVICE_TYPE = 0x0026;
    pub const FILE_DEVICE_8042_PORT: DEVICE_TYPE = 0x0027;
    pub const FILE_DEVICE_NETWORK_REDIRECTOR: DEVICE_TYPE = 0x0028;
    pub const FILE_DEVICE_BATTERY: DEVICE_TYPE = 0x0029;
    pub const FILE_DEVICE_BUS_EXTENDER: DEVICE_TYPE = 0x002a;
    pub const FILE_DEVICE_MODEM: DEVICE_TYPE = 0x002b;
    pub const FILE_DEVICE_VDM: DEVICE_TYPE = 0x002c;
    pub const FILE_DEVICE_MASS_STORAGE: DEVICE_TYPE = 0x002d;
    pub const FILE_DEVICE_SMB: DEVICE_TYPE = 0x002e;
    pub const FILE_DEVICE_KS: DEVICE_TYPE = 0x002f;
    pub const FILE_DEVICE_CHANGER: DEVICE_TYPE = 0x0030;
    pub const FILE_DEVICE_SMARTCARD: DEVICE_TYPE = 0x0031;
    pub const FILE_DEVICE_ACPI: DEVICE_TYPE = 0x0032;
    pub const FILE_DEVICE_DVD: DEVICE_TYPE = 0x0033;
    pub const FILE_DEVICE_FULLSCREEN_VIDEO: DEVICE_TYPE = 0x0034;
    pub const FILE_DEVICE_DFS_FILE_SYSTEM: DEVICE_TYPE = 0x0035;
    pub const FILE_DEVICE_DFS_VOLUME: DEVICE_TYPE = 0x0036;
    pub const FILE_DEVICE_SERENUM: DEVICE_TYPE = 0x0037;
    pub const FILE_DEVICE_TERMSRV: DEVICE_TYPE = 0x0038;
    pub const FILE_DEVICE_KSEC: DEVICE_TYPE = 0x0039;
    pub const FILE_DEVICE_FIPS: DEVICE_TYPE = 0x003a;
    pub const FILE_DEVICE_INFINIBAND: DEVICE_TYPE = 0x003b;
    // TODO: missing values?

    pub const FILE_DEVICE_VMBUS: DEVICE_TYPE = 0x003e;
    pub const FILE_DEVICE_CRYPT_PROVIDER: DEVICE_TYPE = 0x003f;
    pub const FILE_DEVICE_WPD: DEVICE_TYPE = 0x0040;
    pub const FILE_DEVICE_BLUETOOTH: DEVICE_TYPE = 0x0041;
    pub const FILE_DEVICE_MT_COMPOSITE: DEVICE_TYPE = 0x0042;
    pub const FILE_DEVICE_MT_TRANSPORT: DEVICE_TYPE = 0x0043;
    pub const FILE_DEVICE_BIOMETRIC: DEVICE_TYPE = 0x0044;
    pub const FILE_DEVICE_PMI: DEVICE_TYPE = 0x0045;
    pub const FILE_DEVICE_EHSTOR: DEVICE_TYPE = 0x0046;
    pub const FILE_DEVICE_DEVAPI: DEVICE_TYPE = 0x0047;
    pub const FILE_DEVICE_GPIO: DEVICE_TYPE = 0x0048;
    pub const FILE_DEVICE_USBEX: DEVICE_TYPE = 0x0049;
    pub const FILE_DEVICE_CONSOLE: DEVICE_TYPE = 0x0050;
    pub const FILE_DEVICE_NFP: DEVICE_TYPE = 0x0051;
    pub const FILE_DEVICE_SYSENV: DEVICE_TYPE = 0x0052;
    pub const FILE_DEVICE_VIRTUAL_BLOCK: DEVICE_TYPE = 0x0053;
    pub const FILE_DEVICE_POINT_OF_SERVICE: DEVICE_TYPE = 0x0054;
    pub const FILE_DEVICE_STORAGE_REPLICATION: DEVICE_TYPE = 0x0055;
    pub const FILE_DEVICE_TRUST_ENV: DEVICE_TYPE = 0x0056;
    pub const FILE_DEVICE_UCM: DEVICE_TYPE = 0x0057;
    pub const FILE_DEVICE_UCMTCPCI: DEVICE_TYPE = 0x0058;
    pub const FILE_DEVICE_PERSISTENT_MEMORY: DEVICE_TYPE = 0x0059;
    pub const FILE_DEVICE_NVDIMM: DEVICE_TYPE = 0x005a;
    pub const FILE_DEVICE_HOLOGRAPHIC: DEVICE_TYPE = 0x005b;
    pub const FILE_DEVICE_SDFXHCI: DEVICE_TYPE = 0x005c;

    /// https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/buffer-descriptions-for-i-o-control-codes
    pub const TransferType = enum(u2) {
        METHOD_BUFFERED = 0,
        METHOD_IN_DIRECT = 1,
        METHOD_OUT_DIRECT = 2,
        METHOD_NEITHER = 3,
    };

    pub const FILE_ANY_ACCESS = 0;
    pub const FILE_READ_ACCESS = 1;
    pub const FILE_WRITE_ACCESS = 2;

    /// https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/defining-i-o-control-codes
    pub fn CTL_CODE(deviceType: u16, function: u12, method: TransferType, access: u2) DWORD {
        return (@as(DWORD, deviceType) << 16) |
            (@as(DWORD, access) << 14) |
            (@as(DWORD, function) << 2) |
            @enumToInt(method);
    }

    pub const INVALID_HANDLE_VALUE = @intToPtr(HANDLE, maxInt(usize));

    pub const INVALID_FILE_ATTRIBUTES = @as(DWORD, maxInt(DWORD));

    pub const FILE_ALL_INFORMATION = extern struct {
        BasicInformation: FILE_BASIC_INFORMATION,
        StandardInformation: FILE_STANDARD_INFORMATION,
        InternalInformation: FILE_INTERNAL_INFORMATION,
        EaInformation: FILE_EA_INFORMATION,
        AccessInformation: FILE_ACCESS_INFORMATION,
        PositionInformation: FILE_POSITION_INFORMATION,
        ModeInformation: FILE_MODE_INFORMATION,
        AlignmentInformation: FILE_ALIGNMENT_INFORMATION,
        NameInformation: FILE_NAME_INFORMATION,
    };

    pub const FILE_BASIC_INFORMATION = extern struct {
        CreationTime: LARGE_INTEGER,
        LastAccessTime: LARGE_INTEGER,
        LastWriteTime: LARGE_INTEGER,
        ChangeTime: LARGE_INTEGER,
        FileAttributes: ULONG,
    };

    pub const FILE_STANDARD_INFORMATION = extern struct {
        AllocationSize: LARGE_INTEGER,
        EndOfFile: LARGE_INTEGER,
        NumberOfLinks: ULONG,
        DeletePending: BOOLEAN,
        Directory: BOOLEAN,
    };

    pub const FILE_INTERNAL_INFORMATION = extern struct {
        IndexNumber: LARGE_INTEGER,
    };

    pub const FILE_EA_INFORMATION = extern struct {
        EaSize: ULONG,
    };

    pub const FILE_ACCESS_INFORMATION = extern struct {
        AccessFlags: ACCESS_MASK,
    };

    pub const FILE_POSITION_INFORMATION = extern struct {
        CurrentByteOffset: LARGE_INTEGER,
    };

    pub const FILE_END_OF_FILE_INFORMATION = extern struct {
        EndOfFile: LARGE_INTEGER,
    };

    pub const FILE_MODE_INFORMATION = extern struct {
        Mode: ULONG,
    };

    pub const FILE_ALIGNMENT_INFORMATION = extern struct {
        AlignmentRequirement: ULONG,
    };

    pub const FILE_NAME_INFORMATION = extern struct {
        FileNameLength: ULONG,
        FileName: [1]WCHAR,
    };

    pub const FILE_RENAME_INFORMATION = extern struct {
        ReplaceIfExists: BOOLEAN,
        RootDirectory: ?HANDLE,
        FileNameLength: ULONG,
        FileName: [1]WCHAR,
    };

    pub const IO_STATUS_BLOCK = extern struct {
        // "DUMMYUNIONNAME" expands to "u"

        u: extern union {
            Status: NTSTATUS,
            Pointer: ?*anyopaque,
        },
        Information: ULONG_PTR,
    };

    pub const FILE_INFORMATION_CLASS = enum(c_int) {
        FileDirectoryInformation = 1,
        FileFullDirectoryInformation,
        FileBothDirectoryInformation,
        FileBasicInformation,
        FileStandardInformation,
        FileInternalInformation,
        FileEaInformation,
        FileAccessInformation,
        FileNameInformation,
        FileRenameInformation,
        FileLinkInformation,
        FileNamesInformation,
        FileDispositionInformation,
        FilePositionInformation,
        FileFullEaInformation,
        FileModeInformation,
        FileAlignmentInformation,
        FileAllInformation,
        FileAllocationInformation,
        FileEndOfFileInformation,
        FileAlternateNameInformation,
        FileStreamInformation,
        FilePipeInformation,
        FilePipeLocalInformation,
        FilePipeRemoteInformation,
        FileMailslotQueryInformation,
        FileMailslotSetInformation,
        FileCompressionInformation,
        FileObjectIdInformation,
        FileCompletionInformation,
        FileMoveClusterInformation,
        FileQuotaInformation,
        FileReparsePointInformation,
        FileNetworkOpenInformation,
        FileAttributeTagInformation,
        FileTrackingInformation,
        FileIdBothDirectoryInformation,
        FileIdFullDirectoryInformation,
        FileValidDataLengthInformation,
        FileShortNameInformation,
        FileIoCompletionNotificationInformation,
        FileIoStatusBlockRangeInformation,
        FileIoPriorityHintInformation,
        FileSfioReserveInformation,
        FileSfioVolumeInformation,
        FileHardLinkInformation,
        FileProcessIdsUsingFileInformation,
        FileNormalizedNameInformation,
        FileNetworkPhysicalNameInformation,
        FileIdGlobalTxDirectoryInformation,
        FileIsRemoteDeviceInformation,
        FileUnusedInformation,
        FileNumaNodeInformation,
        FileStandardLinkInformation,
        FileRemoteProtocolInformation,
        FileRenameInformationBypassAccessCheck,
        FileLinkInformationBypassAccessCheck,
        FileVolumeNameInformation,
        FileIdInformation,
        FileIdExtdDirectoryInformation,
        FileReplaceCompletionInformation,
        FileHardLinkFullIdInformation,
        FileIdExtdBothDirectoryInformation,
        FileDispositionInformationEx,
        FileRenameInformationEx,
        FileRenameInformationExBypassAccessCheck,
        FileDesiredStorageClassInformation,
        FileStatInformation,
        FileMemoryPartitionInformation,
        FileStatLxInformation,
        FileCaseSensitiveInformation,
        FileLinkInformationEx,
        FileLinkInformationExBypassAccessCheck,
        FileStorageReserveIdInformation,
        FileCaseSensitiveInformationForceAccessCheck,
        FileMaximumInformation,
    };

    pub const OVERLAPPED = extern struct {
        Internal: ULONG_PTR,
        InternalHigh: ULONG_PTR,
        DUMMYUNIONNAME: extern union {
            DUMMYSTRUCTNAME: extern struct {
                Offset: DWORD,
                OffsetHigh: DWORD,
            },
            Pointer: ?PVOID,
        },
        hEvent: ?HANDLE,
    };

    pub const OVERLAPPED_ENTRY = extern struct {
        lpCompletionKey: ULONG_PTR,
        lpOverlapped: *OVERLAPPED,
        Internal: ULONG_PTR,
        dwNumberOfBytesTransferred: DWORD,
    };

    pub const MAX_PATH = 260;

    // TODO issue #305

    pub const FILE_INFO_BY_HANDLE_CLASS = u32;
    pub const FileBasicInfo = 0;
    pub const FileStandardInfo = 1;
    pub const FileNameInfo = 2;
    pub const FileRenameInfo = 3;
    pub const FileDispositionInfo = 4;
    pub const FileAllocationInfo = 5;
    pub const FileEndOfFileInfo = 6;
    pub const FileStreamInfo = 7;
    pub const FileCompressionInfo = 8;
    pub const FileAttributeTagInfo = 9;
    pub const FileIdBothDirectoryInfo = 10;
    pub const FileIdBothDirectoryRestartInfo = 11;
    pub const FileIoPriorityHintInfo = 12;
    pub const FileRemoteProtocolInfo = 13;
    pub const FileFullDirectoryInfo = 14;
    pub const FileFullDirectoryRestartInfo = 15;
    pub const FileStorageInfo = 16;
    pub const FileAlignmentInfo = 17;
    pub const FileIdInfo = 18;
    pub const FileIdExtdDirectoryInfo = 19;
    pub const FileIdExtdDirectoryRestartInfo = 20;

    pub const BY_HANDLE_FILE_INFORMATION = extern struct {
        dwFileAttributes: DWORD,
        ftCreationTime: FILETIME,
        ftLastAccessTime: FILETIME,
        ftLastWriteTime: FILETIME,
        dwVolumeSerialNumber: DWORD,
        nFileSizeHigh: DWORD,
        nFileSizeLow: DWORD,
        nNumberOfLinks: DWORD,
        nFileIndexHigh: DWORD,
        nFileIndexLow: DWORD,
    };

    pub const FILE_NAME_INFO = extern struct {
        FileNameLength: DWORD,
        FileName: [1]WCHAR,
    };

    /// Return the normalized drive name. This is the default.
    pub const FILE_NAME_NORMALIZED = 0x0;

    /// Return the opened file name (not normalized).
    pub const FILE_NAME_OPENED = 0x8;

    /// Return the path with the drive letter. This is the default.
    pub const VOLUME_NAME_DOS = 0x0;

    /// Return the path with a volume GUID path instead of the drive name.
    pub const VOLUME_NAME_GUID = 0x1;

    /// Return the path with no drive information.
    pub const VOLUME_NAME_NONE = 0x4;

    /// Return the path with the volume device path.
    pub const VOLUME_NAME_NT = 0x2;

    pub const SECURITY_ATTRIBUTES = extern struct {
        nLength: DWORD,
        lpSecurityDescriptor: ?*anyopaque,
        bInheritHandle: BOOL,
    };

    pub const PIPE_ACCESS_INBOUND = 0x00000001;
    pub const PIPE_ACCESS_OUTBOUND = 0x00000002;
    pub const PIPE_ACCESS_DUPLEX = 0x00000003;

    pub const PIPE_TYPE_BYTE = 0x00000000;
    pub const PIPE_TYPE_MESSAGE = 0x00000004;

    pub const PIPE_READMODE_BYTE = 0x00000000;
    pub const PIPE_READMODE_MESSAGE = 0x00000002;

    pub const PIPE_WAIT = 0x00000000;
    pub const PIPE_NOWAIT = 0x00000001;

    pub const GENERIC_READ = 0x80000000;
    pub const GENERIC_WRITE = 0x40000000;
    pub const GENERIC_EXECUTE = 0x20000000;
    pub const GENERIC_ALL = 0x10000000;

    pub const FILE_SHARE_DELETE = 0x00000004;
    pub const FILE_SHARE_READ = 0x00000001;
    pub const FILE_SHARE_WRITE = 0x00000002;

    pub const DELETE = 0x00010000;
    pub const READ_CONTROL = 0x00020000;
    pub const WRITE_DAC = 0x00040000;
    pub const WRITE_OWNER = 0x00080000;
    pub const SYNCHRONIZE = 0x00100000;
    pub const STANDARD_RIGHTS_READ = READ_CONTROL;
    pub const STANDARD_RIGHTS_WRITE = READ_CONTROL;
    pub const STANDARD_RIGHTS_EXECUTE = READ_CONTROL;
    pub const STANDARD_RIGHTS_REQUIRED = DELETE | READ_CONTROL | WRITE_DAC | WRITE_OWNER;
    pub const MAXIMUM_ALLOWED = 0x02000000;

    // disposition for NtCreateFile

    pub const FILE_SUPERSEDE = 0;
    pub const FILE_OPEN = 1;
    pub const FILE_CREATE = 2;
    pub const FILE_OPEN_IF = 3;
    pub const FILE_OVERWRITE = 4;
    pub const FILE_OVERWRITE_IF = 5;
    pub const FILE_MAXIMUM_DISPOSITION = 5;

    // flags for NtCreateFile and NtOpenFile

    pub const FILE_READ_DATA = 0x00000001;
    pub const FILE_LIST_DIRECTORY = 0x00000001;
    pub const FILE_WRITE_DATA = 0x00000002;
    pub const FILE_ADD_FILE = 0x00000002;
    pub const FILE_APPEND_DATA = 0x00000004;
    pub const FILE_ADD_SUBDIRECTORY = 0x00000004;
    pub const FILE_CREATE_PIPE_INSTANCE = 0x00000004;
    pub const FILE_READ_EA = 0x00000008;
    pub const FILE_WRITE_EA = 0x00000010;
    pub const FILE_EXECUTE = 0x00000020;
    pub const FILE_TRAVERSE = 0x00000020;
    pub const FILE_DELETE_CHILD = 0x00000040;
    pub const FILE_READ_ATTRIBUTES = 0x00000080;
    pub const FILE_WRITE_ATTRIBUTES = 0x00000100;

    pub const FILE_DIRECTORY_FILE = 0x00000001;
    pub const FILE_WRITE_THROUGH = 0x00000002;
    pub const FILE_SEQUENTIAL_ONLY = 0x00000004;
    pub const FILE_NO_INTERMEDIATE_BUFFERING = 0x00000008;
    pub const FILE_SYNCHRONOUS_IO_ALERT = 0x00000010;
    pub const FILE_SYNCHRONOUS_IO_NONALERT = 0x00000020;
    pub const FILE_NON_DIRECTORY_FILE = 0x00000040;
    pub const FILE_CREATE_TREE_CONNECTION = 0x00000080;
    pub const FILE_COMPLETE_IF_OPLOCKED = 0x00000100;
    pub const FILE_NO_EA_KNOWLEDGE = 0x00000200;
    pub const FILE_OPEN_FOR_RECOVERY = 0x00000400;
    pub const FILE_RANDOM_ACCESS = 0x00000800;
    pub const FILE_DELETE_ON_CLOSE = 0x00001000;
    pub const FILE_OPEN_BY_FILE_ID = 0x00002000;
    pub const FILE_OPEN_FOR_BACKUP_INTENT = 0x00004000;
    pub const FILE_NO_COMPRESSION = 0x00008000;
    pub const FILE_RESERVE_OPFILTER = 0x00100000;
    pub const FILE_OPEN_REPARSE_POINT = 0x00200000;
    pub const FILE_OPEN_OFFLINE_FILE = 0x00400000;
    pub const FILE_OPEN_FOR_FREE_SPACE_QUERY = 0x00800000;

    pub const CREATE_ALWAYS = 2;
    pub const CREATE_NEW = 1;
    pub const OPEN_ALWAYS = 4;
    pub const OPEN_EXISTING = 3;
    pub const TRUNCATE_EXISTING = 5;

    pub const FILE_ATTRIBUTE_ARCHIVE = 0x20;
    pub const FILE_ATTRIBUTE_COMPRESSED = 0x800;
    pub const FILE_ATTRIBUTE_DEVICE = 0x40;
    pub const FILE_ATTRIBUTE_DIRECTORY = 0x10;
    pub const FILE_ATTRIBUTE_ENCRYPTED = 0x4000;
    pub const FILE_ATTRIBUTE_HIDDEN = 0x2;
    pub const FILE_ATTRIBUTE_INTEGRITY_STREAM = 0x8000;
    pub const FILE_ATTRIBUTE_NORMAL = 0x80;
    pub const FILE_ATTRIBUTE_NOT_CONTENT_INDEXED = 0x2000;
    pub const FILE_ATTRIBUTE_NO_SCRUB_DATA = 0x20000;
    pub const FILE_ATTRIBUTE_OFFLINE = 0x1000;
    pub const FILE_ATTRIBUTE_READONLY = 0x1;
    pub const FILE_ATTRIBUTE_RECALL_ON_DATA_ACCESS = 0x400000;
    pub const FILE_ATTRIBUTE_RECALL_ON_OPEN = 0x40000;
    pub const FILE_ATTRIBUTE_REPARSE_POINT = 0x400;
    pub const FILE_ATTRIBUTE_SPARSE_FILE = 0x200;
    pub const FILE_ATTRIBUTE_SYSTEM = 0x4;
    pub const FILE_ATTRIBUTE_TEMPORARY = 0x100;
    pub const FILE_ATTRIBUTE_VIRTUAL = 0x10000;

    // flags for CreateEvent

    pub const CREATE_EVENT_INITIAL_SET = 0x00000002;
    pub const CREATE_EVENT_MANUAL_RESET = 0x00000001;

    pub const EVENT_ALL_ACCESS = 0x1F0003;
    pub const EVENT_MODIFY_STATE = 0x0002;

    // MEMORY_BASIC_INFORMATION.Type flags for VirtualQuery

    pub const MEM_IMAGE = 0x1000000;
    pub const MEM_MAPPED = 0x40000;
    pub const MEM_PRIVATE = 0x20000;

    pub const PROCESS_INFORMATION = extern struct {
        hProcess: HANDLE,
        hThread: HANDLE,
        dwProcessId: DWORD,
        dwThreadId: DWORD,
    };

    pub const STARTUPINFOW = extern struct {
        cb: DWORD,
        lpReserved: ?LPWSTR,
        lpDesktop: ?LPWSTR,
        lpTitle: ?LPWSTR,
        dwX: DWORD,
        dwY: DWORD,
        dwXSize: DWORD,
        dwYSize: DWORD,
        dwXCountChars: DWORD,
        dwYCountChars: DWORD,
        dwFillAttribute: DWORD,
        dwFlags: DWORD,
        wShowWindow: WORD,
        cbReserved2: WORD,
        lpReserved2: ?*BYTE,
        hStdInput: ?HANDLE,
        hStdOutput: ?HANDLE,
        hStdError: ?HANDLE,
    };

    pub const STARTF_FORCEONFEEDBACK = 0x00000040;
    pub const STARTF_FORCEOFFFEEDBACK = 0x00000080;
    pub const STARTF_PREVENTPINNING = 0x00002000;
    pub const STARTF_RUNFULLSCREEN = 0x00000020;
    pub const STARTF_TITLEISAPPID = 0x00001000;
    pub const STARTF_TITLEISLINKNAME = 0x00000800;
    pub const STARTF_UNTRUSTEDSOURCE = 0x00008000;
    pub const STARTF_USECOUNTCHARS = 0x00000008;
    pub const STARTF_USEFILLATTRIBUTE = 0x00000010;
    pub const STARTF_USEHOTKEY = 0x00000200;
    pub const STARTF_USEPOSITION = 0x00000004;
    pub const STARTF_USESHOWWINDOW = 0x00000001;
    pub const STARTF_USESIZE = 0x00000002;
    pub const STARTF_USESTDHANDLES = 0x00000100;

    pub const INFINITE = 4294967295;

    pub const MAXIMUM_WAIT_OBJECTS = 64;

    pub const WAIT_ABANDONED = 0x00000080;
    pub const WAIT_ABANDONED_0 = WAIT_ABANDONED + 0;
    pub const WAIT_OBJECT_0 = 0x00000000;
    pub const WAIT_TIMEOUT = 0x00000102;
    pub const WAIT_FAILED = 0xFFFFFFFF;

    pub const HANDLE_FLAG_INHERIT = 0x00000001;
    pub const HANDLE_FLAG_PROTECT_FROM_CLOSE = 0x00000002;

    pub const MOVEFILE_COPY_ALLOWED = 2;
    pub const MOVEFILE_CREATE_HARDLINK = 16;
    pub const MOVEFILE_DELAY_UNTIL_REBOOT = 4;
    pub const MOVEFILE_FAIL_IF_NOT_TRACKABLE = 32;
    pub const MOVEFILE_REPLACE_EXISTING = 1;
    pub const MOVEFILE_WRITE_THROUGH = 8;

    pub const FILE_BEGIN = 0;
    pub const FILE_CURRENT = 1;
    pub const FILE_END = 2;

    pub const HEAP_CREATE_ENABLE_EXECUTE = 0x00040000;
    pub const HEAP_REALLOC_IN_PLACE_ONLY = 0x00000010;
    pub const HEAP_GENERATE_EXCEPTIONS = 0x00000004;
    pub const HEAP_NO_SERIALIZE = 0x00000001;

    // AllocationType values

    pub const MEM_COMMIT = 0x1000;
    pub const MEM_RESERVE = 0x2000;
    pub const MEM_FREE = 0x10000;
    pub const MEM_RESET = 0x80000;
    pub const MEM_RESET_UNDO = 0x1000000;
    pub const MEM_LARGE_PAGES = 0x20000000;
    pub const MEM_PHYSICAL = 0x400000;
    pub const MEM_TOP_DOWN = 0x100000;
    pub const MEM_WRITE_WATCH = 0x200000;

    // Protect values

    pub const PAGE_EXECUTE = 0x10;
    pub const PAGE_EXECUTE_READ = 0x20;
    pub const PAGE_EXECUTE_READWRITE = 0x40;
    pub const PAGE_EXECUTE_WRITECOPY = 0x80;
    pub const PAGE_NOACCESS = 0x01;
    pub const PAGE_READONLY = 0x02;
    pub const PAGE_READWRITE = 0x04;
    pub const PAGE_WRITECOPY = 0x08;
    pub const PAGE_TARGETS_INVALID = 0x40000000;
    pub const PAGE_TARGETS_NO_UPDATE = 0x40000000; // Same as PAGE_TARGETS_INVALID

    pub const PAGE_GUARD = 0x100;
    pub const PAGE_NOCACHE = 0x200;
    pub const PAGE_WRITECOMBINE = 0x400;

    // FreeType values

    pub const MEM_COALESCE_PLACEHOLDERS = 0x1;
    pub const MEM_RESERVE_PLACEHOLDERS = 0x2;
    pub const MEM_DECOMMIT = 0x4000;
    pub const MEM_RELEASE = 0x8000;

    pub const PTHREAD_START_ROUTINE = std.meta.FnPtr(fn (LPVOID) callconv(.C) DWORD);
    pub const LPTHREAD_START_ROUTINE = PTHREAD_START_ROUTINE;

    pub const WIN32_FIND_DATAW = extern struct {
        dwFileAttributes: DWORD,
        ftCreationTime: FILETIME,
        ftLastAccessTime: FILETIME,
        ftLastWriteTime: FILETIME,
        nFileSizeHigh: DWORD,
        nFileSizeLow: DWORD,
        dwReserved0: DWORD,
        dwReserved1: DWORD,
        cFileName: [260]u16,
        cAlternateFileName: [14]u16,
    };

    pub const FILETIME = extern struct {
        dwLowDateTime: DWORD,
        dwHighDateTime: DWORD,
    };

    pub const SYSTEM_INFO = extern struct {
        anon1: extern union {
            dwOemId: DWORD,
            anon2: extern struct {
                wProcessorArchitecture: WORD,
                wReserved: WORD,
            },
        },
        dwPageSize: DWORD,
        lpMinimumApplicationAddress: LPVOID,
        lpMaximumApplicationAddress: LPVOID,
        dwActiveProcessorMask: DWORD_PTR,
        dwNumberOfProcessors: DWORD,
        dwProcessorType: DWORD,
        dwAllocationGranularity: DWORD,
        wProcessorLevel: WORD,
        wProcessorRevision: WORD,
    };

    pub const HRESULT = c_long;

    pub const KNOWNFOLDERID = GUID;
    pub const GUID = extern struct {
        Data1: u32,
        Data2: u16,
        Data3: u16,
        Data4: [8]u8,

        const hex_offsets = switch (builtin.target.cpu.arch.endian()) {
            .Big => [16]u6{
                0,  2,  4,  6,
                9,  11, 14, 16,
                19, 21, 24, 26,
                28, 30, 32, 34,
            },
            .Little => [16]u6{
                6,  4,  2,  0,
                11, 9,  16, 14,
                19, 21, 24, 26,
                28, 30, 32, 34,
            },
        };

        pub fn parse(s: []const u8) GUID {
            assert(s[0] == '{');
            assert(s[37] == '}');
            return parseNoBraces(s[1 .. s.len - 1]) catch @panic("invalid GUID string");
        }

        pub fn parseNoBraces(s: []const u8) !GUID {
            assert(s.len == 36);
            assert(s[8] == '-');
            assert(s[13] == '-');
            assert(s[18] == '-');
            assert(s[23] == '-');
            var bytes: [16]u8 = undefined;
            for (hex_offsets) |hex_offset, i| {
                bytes[i] = (try std.fmt.charToDigit(s[hex_offset], 16)) << 4 |
                    try std.fmt.charToDigit(s[hex_offset + 1], 16);
            }
            return @bitCast(GUID, bytes);
        }
    };

    test "GUID" {
        try std.testing.expectEqual(
            GUID{
                .Data1 = 0x01234567,
                .Data2 = 0x89ab,
                .Data3 = 0xef10,
                .Data4 = "\x32\x54\x76\x98\xba\xdc\xfe\x91".*,
            },
            GUID.parse("{01234567-89AB-EF10-3254-7698badcfe91}"),
        );
    }

    pub const FOLDERID_LocalAppData = GUID.parse("{F1B32785-6FBA-4FCF-9D55-7B8E7F157091}");

    pub const KF_FLAG_DEFAULT = 0;
    pub const KF_FLAG_NO_APPCONTAINER_REDIRECTION = 65536;
    pub const KF_FLAG_CREATE = 32768;
    pub const KF_FLAG_DONT_VERIFY = 16384;
    pub const KF_FLAG_DONT_UNEXPAND = 8192;
    pub const KF_FLAG_NO_ALIAS = 4096;
    pub const KF_FLAG_INIT = 2048;
    pub const KF_FLAG_DEFAULT_PATH = 1024;
    pub const KF_FLAG_NOT_PARENT_RELATIVE = 512;
    pub const KF_FLAG_SIMPLE_IDLIST = 256;
    pub const KF_FLAG_ALIAS_ONLY = -2147483648;

    pub const S_OK = 0;
    pub const E_NOTIMPL = @bitCast(c_long, @as(c_ulong, 0x80004001));
    pub const E_NOINTERFACE = @bitCast(c_long, @as(c_ulong, 0x80004002));
    pub const E_POINTER = @bitCast(c_long, @as(c_ulong, 0x80004003));
    pub const E_ABORT = @bitCast(c_long, @as(c_ulong, 0x80004004));
    pub const E_FAIL = @bitCast(c_long, @as(c_ulong, 0x80004005));
    pub const E_UNEXPECTED = @bitCast(c_long, @as(c_ulong, 0x8000FFFF));
    pub const E_ACCESSDENIED = @bitCast(c_long, @as(c_ulong, 0x80070005));
    pub const E_HANDLE = @bitCast(c_long, @as(c_ulong, 0x80070006));
    pub const E_OUTOFMEMORY = @bitCast(c_long, @as(c_ulong, 0x8007000E));
    pub const E_INVALIDARG = @bitCast(c_long, @as(c_ulong, 0x80070057));

    pub const FILE_FLAG_BACKUP_SEMANTICS = 0x02000000;
    pub const FILE_FLAG_DELETE_ON_CLOSE = 0x04000000;
    pub const FILE_FLAG_NO_BUFFERING = 0x20000000;
    pub const FILE_FLAG_OPEN_NO_RECALL = 0x00100000;
    pub const FILE_FLAG_OPEN_REPARSE_POINT = 0x00200000;
    pub const FILE_FLAG_OVERLAPPED = 0x40000000;
    pub const FILE_FLAG_POSIX_SEMANTICS = 0x0100000;
    pub const FILE_FLAG_RANDOM_ACCESS = 0x10000000;
    pub const FILE_FLAG_SESSION_AWARE = 0x00800000;
    pub const FILE_FLAG_SEQUENTIAL_SCAN = 0x08000000;
    pub const FILE_FLAG_WRITE_THROUGH = 0x80000000;

    pub const RECT = extern struct {
        left: LONG,
        top: LONG,
        right: LONG,
        bottom: LONG,
    };

    pub const SMALL_RECT = extern struct {
        Left: SHORT,
        Top: SHORT,
        Right: SHORT,
        Bottom: SHORT,
    };

    pub const POINT = extern struct {
        x: LONG,
        y: LONG,
    };

    pub const COORD = extern struct {
        X: SHORT,
        Y: SHORT,
    };

    pub const CREATE_UNICODE_ENVIRONMENT = 1024;

    pub const TLS_OUT_OF_INDEXES = 4294967295;
    pub const IMAGE_TLS_DIRECTORY = extern struct {
        StartAddressOfRawData: usize,
        EndAddressOfRawData: usize,
        AddressOfIndex: usize,
        AddressOfCallBacks: usize,
        SizeOfZeroFill: u32,
        Characteristics: u32,
    };
    pub const IMAGE_TLS_DIRECTORY64 = IMAGE_TLS_DIRECTORY;
    pub const IMAGE_TLS_DIRECTORY32 = IMAGE_TLS_DIRECTORY;

    pub const PIMAGE_TLS_CALLBACK = ?std.meta.FnPtr(fn (PVOID, DWORD, PVOID) callconv(.C) void);

    pub const PROV_RSA_FULL = 1;

    pub const REGSAM = ACCESS_MASK;
    pub const ACCESS_MASK = DWORD;
    pub const LSTATUS = LONG;

    pub const HKEY = *opaque {};

    pub const HKEY_LOCAL_MACHINE: HKEY = @intToPtr(HKEY, 0x80000002);

    /// Combines the STANDARD_RIGHTS_REQUIRED, KEY_QUERY_VALUE, KEY_SET_VALUE, KEY_CREATE_SUB_KEY,
    /// KEY_ENUMERATE_SUB_KEYS, KEY_NOTIFY, and KEY_CREATE_LINK access rights.
    pub const KEY_ALL_ACCESS = 0xF003F;
    /// Reserved for system use.
    pub const KEY_CREATE_LINK = 0x0020;
    /// Required to create a subkey of a registry key.
    pub const KEY_CREATE_SUB_KEY = 0x0004;
    /// Required to enumerate the subkeys of a registry key.
    pub const KEY_ENUMERATE_SUB_KEYS = 0x0008;
    /// Equivalent to KEY_READ.
    pub const KEY_EXECUTE = 0x20019;
    /// Required to request change notifications for a registry key or for subkeys of a registry key.
    pub const KEY_NOTIFY = 0x0010;
    /// Required to query the values of a registry key.
    pub const KEY_QUERY_VALUE = 0x0001;
    /// Combines the STANDARD_RIGHTS_READ, KEY_QUERY_VALUE, KEY_ENUMERATE_SUB_KEYS, and KEY_NOTIFY values.
    pub const KEY_READ = 0x20019;
    /// Required to create, delete, or set a registry value.
    pub const KEY_SET_VALUE = 0x0002;
    /// Indicates that an application on 64-bit Windows should operate on the 32-bit registry view.
    /// This flag is ignored by 32-bit Windows.
    pub const KEY_WOW64_32KEY = 0x0200;
    /// Indicates that an application on 64-bit Windows should operate on the 64-bit registry view.
    /// This flag is ignored by 32-bit Windows.
    pub const KEY_WOW64_64KEY = 0x0100;
    /// Combines the STANDARD_RIGHTS_WRITE, KEY_SET_VALUE, and KEY_CREATE_SUB_KEY access rights.
    pub const KEY_WRITE = 0x20006;

    /// Open symbolic link.
    pub const REG_OPTION_OPEN_LINK: DWORD = 0x8;

    pub const RTL_QUERY_REGISTRY_TABLE = extern struct {
        QueryRoutine: RTL_QUERY_REGISTRY_ROUTINE,
        Flags: ULONG,
        Name: ?PWSTR,
        EntryContext: ?*anyopaque,
        DefaultType: ULONG,
        DefaultData: ?*anyopaque,
        DefaultLength: ULONG,
    };

    pub const RTL_QUERY_REGISTRY_ROUTINE = ?std.meta.FnPtr(fn (
        PWSTR,
        ULONG,
        ?*anyopaque,
        ULONG,
        ?*anyopaque,
        ?*anyopaque,
    ) callconv(WINAPI) NTSTATUS);

    /// Path is a full path
    pub const RTL_REGISTRY_ABSOLUTE = 0;
    /// \Registry\Machine\System\CurrentControlSet\Services
    pub const RTL_REGISTRY_SERVICES = 1;
    /// \Registry\Machine\System\CurrentControlSet\Control
    pub const RTL_REGISTRY_CONTROL = 2;
    /// \Registry\Machine\Software\Microsoft\Windows NT\CurrentVersion
    pub const RTL_REGISTRY_WINDOWS_NT = 3;
    /// \Registry\Machine\Hardware\DeviceMap
    pub const RTL_REGISTRY_DEVICEMAP = 4;
    /// \Registry\User\CurrentUser
    pub const RTL_REGISTRY_USER = 5;
    pub const RTL_REGISTRY_MAXIMUM = 6;

    /// Low order bits are registry handle
    pub const RTL_REGISTRY_HANDLE = 0x40000000;
    /// Indicates the key node is optional
    pub const RTL_REGISTRY_OPTIONAL = 0x80000000;

    /// Name is a subkey and remainder of table or until next subkey are value
    /// names for that subkey to look at.
    pub const RTL_QUERY_REGISTRY_SUBKEY = 0x00000001;

    /// Reset current key to original key for this and all following table entries.
    pub const RTL_QUERY_REGISTRY_TOPKEY = 0x00000002;

    /// Fail if no match found for this table entry.
    pub const RTL_QUERY_REGISTRY_REQUIRED = 0x00000004;

    /// Used to mark a table entry that has no value name, just wants a call out, not
    /// an enumeration of all values.
    pub const RTL_QUERY_REGISTRY_NOVALUE = 0x00000008;

    /// Used to suppress the expansion of REG_MULTI_SZ into multiple callouts or
    /// to prevent the expansion of environment variable values in REG_EXPAND_SZ.
    pub const RTL_QUERY_REGISTRY_NOEXPAND = 0x00000010;

    /// QueryRoutine field ignored.  EntryContext field points to location to store value.
    /// For null terminated strings, EntryContext points to UNICODE_STRING structure that
    /// that describes maximum size of buffer. If .Buffer field is NULL then a buffer is
    /// allocated.
    pub const RTL_QUERY_REGISTRY_DIRECT = 0x00000020;

    /// Used to delete value keys after they are queried.
    pub const RTL_QUERY_REGISTRY_DELETE = 0x00000040;

    /// Use this flag with the RTL_QUERY_REGISTRY_DIRECT flag to verify that the REG_XXX type
    /// of the stored registry value matches the type expected by the caller.
    /// If the types do not match, the call fails.
    pub const RTL_QUERY_REGISTRY_TYPECHECK = 0x00000100;

    pub const REG = struct {
        /// No value type
        pub const NONE: ULONG = 0;
        /// Unicode nul terminated string
        pub const SZ: ULONG = 1;
        /// Unicode nul terminated string (with environment variable references)
        pub const EXPAND_SZ: ULONG = 2;
        /// Free form binary
        pub const BINARY: ULONG = 3;
        /// 32-bit number
        pub const DWORD: ULONG = 4;
        /// 32-bit number (same as REG_DWORD)
        pub const DWORD_LITTLE_ENDIAN: ULONG = 4;
        /// 32-bit number
        pub const DWORD_BIG_ENDIAN: ULONG = 5;
        /// Symbolic Link (unicode)
        pub const LINK: ULONG = 6;
        /// Multiple Unicode strings
        pub const MULTI_SZ: ULONG = 7;
        /// Resource list in the resource map
        pub const RESOURCE_LIST: ULONG = 8;
        /// Resource list in the hardware description
        pub const FULL_RESOURCE_DESCRIPTOR: ULONG = 9;
        pub const RESOURCE_REQUIREMENTS_LIST: ULONG = 10;
        /// 64-bit number
        pub const QWORD: ULONG = 11;
        /// 64-bit number (same as REG_QWORD)
        pub const QWORD_LITTLE_ENDIAN: ULONG = 11;
    };

    pub const FILE_NOTIFY_INFORMATION = extern struct {
        NextEntryOffset: DWORD,
        Action: DWORD,
        FileNameLength: DWORD,
        // Flexible array member

        // FileName: [1]WCHAR,

    };

    pub const FILE_ACTION_ADDED = 0x00000001;
    pub const FILE_ACTION_REMOVED = 0x00000002;
    pub const FILE_ACTION_MODIFIED = 0x00000003;
    pub const FILE_ACTION_RENAMED_OLD_NAME = 0x00000004;
    pub const FILE_ACTION_RENAMED_NEW_NAME = 0x00000005;

    pub const LPOVERLAPPED_COMPLETION_ROUTINE = ?std.meta.FnPtr(fn (DWORD, DWORD, *OVERLAPPED) callconv(.C) void);

    pub const FILE_NOTIFY_CHANGE_CREATION = 64;
    pub const FILE_NOTIFY_CHANGE_SIZE = 8;
    pub const FILE_NOTIFY_CHANGE_SECURITY = 256;
    pub const FILE_NOTIFY_CHANGE_LAST_ACCESS = 32;
    pub const FILE_NOTIFY_CHANGE_LAST_WRITE = 16;
    pub const FILE_NOTIFY_CHANGE_DIR_NAME = 2;
    pub const FILE_NOTIFY_CHANGE_FILE_NAME = 1;
    pub const FILE_NOTIFY_CHANGE_ATTRIBUTES = 4;

    pub const CONSOLE_SCREEN_BUFFER_INFO = extern struct {
        dwSize: COORD,
        dwCursorPosition: COORD,
        wAttributes: WORD,
        srWindow: SMALL_RECT,
        dwMaximumWindowSize: COORD,
    };

    pub const FOREGROUND_BLUE = 1;
    pub const FOREGROUND_GREEN = 2;
    pub const FOREGROUND_RED = 4;
    pub const FOREGROUND_INTENSITY = 8;

    pub const LIST_ENTRY = extern struct {
        Flink: *LIST_ENTRY,
        Blink: *LIST_ENTRY,
    };

    pub const RTL_CRITICAL_SECTION_DEBUG = extern struct {
        Type: WORD,
        CreatorBackTraceIndex: WORD,
        CriticalSection: *RTL_CRITICAL_SECTION,
        ProcessLocksList: LIST_ENTRY,
        EntryCount: DWORD,
        ContentionCount: DWORD,
        Flags: DWORD,
        CreatorBackTraceIndexHigh: WORD,
        SpareWORD: WORD,
    };

    pub const RTL_CRITICAL_SECTION = extern struct {
        DebugInfo: *RTL_CRITICAL_SECTION_DEBUG,
        LockCount: LONG,
        RecursionCount: LONG,
        OwningThread: HANDLE,
        LockSemaphore: HANDLE,
        SpinCount: ULONG_PTR,
    };

    pub const CRITICAL_SECTION = RTL_CRITICAL_SECTION;
    pub const INIT_ONCE = RTL_RUN_ONCE;
    pub const INIT_ONCE_STATIC_INIT = RTL_RUN_ONCE_INIT;
    pub const INIT_ONCE_FN = std.meta.FnPtr(fn (InitOnce: *INIT_ONCE, Parameter: ?*anyopaque, Context: ?*anyopaque) callconv(.C) BOOL);

    pub const RTL_RUN_ONCE = extern struct {
        Ptr: ?*anyopaque,
    };

    pub const RTL_RUN_ONCE_INIT = RTL_RUN_ONCE{ .Ptr = null };

    pub const COINIT_APARTMENTTHREADED = COINIT.COINIT_APARTMENTTHREADED;
    pub const COINIT_MULTITHREADED = COINIT.COINIT_MULTITHREADED;
    pub const COINIT_DISABLE_OLE1DDE = COINIT.COINIT_DISABLE_OLE1DDE;
    pub const COINIT_SPEED_OVER_MEMORY = COINIT.COINIT_SPEED_OVER_MEMORY;
    pub const COINIT = enum(c_int) {
        COINIT_APARTMENTTHREADED = 2,
        COINIT_MULTITHREADED = 0,
        COINIT_DISABLE_OLE1DDE = 4,
        COINIT_SPEED_OVER_MEMORY = 8,
    };

    pub const MEMORY_BASIC_INFORMATION = extern struct {
        BaseAddress: PVOID,
        AllocationBase: PVOID,
        AllocationProtect: DWORD,
        PartitionId: WORD,
        RegionSize: SIZE_T,
        State: DWORD,
        Protect: DWORD,
        Type: DWORD,
    };

    pub const PMEMORY_BASIC_INFORMATION = *MEMORY_BASIC_INFORMATION;

    /// > The maximum path of 32,767 characters is approximate, because the "\\?\"
    /// > prefix may be expanded to a longer string by the system at run time, and
    /// > this expansion applies to the total length.
    /// from https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file#maximum-path-length-limitation
    pub const PATH_MAX_WIDE = 32767;

    /// > [Each file name component can be] up to the value returned in the
    /// > lpMaximumComponentLength parameter of the GetVolumeInformation function
    /// > (this value is commonly 255 characters)
    /// from https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation
    ///
    /// > The value that is stored in the variable that *lpMaximumComponentLength points to is
    /// > used to indicate that a specified file system supports long names. For example, for
    /// > a FAT file system that supports long names, the function stores the value 255, rather
    /// > than the previous 8.3 indicator. Long names can also be supported on systems that use
    /// > the NTFS file system.
    /// from https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getvolumeinformationw
    ///
    /// The assumption being made here is that while lpMaximumComponentLength may vary, it will never
    /// be larger than 255.
    ///
    /// TODO: More verification of this assumption.
    pub const NAME_MAX = 255;

    pub const FORMAT_MESSAGE_ALLOCATE_BUFFER = 0x00000100;
    pub const FORMAT_MESSAGE_ARGUMENT_ARRAY = 0x00002000;
    pub const FORMAT_MESSAGE_FROM_HMODULE = 0x00000800;
    pub const FORMAT_MESSAGE_FROM_STRING = 0x00000400;
    pub const FORMAT_MESSAGE_FROM_SYSTEM = 0x00001000;
    pub const FORMAT_MESSAGE_IGNORE_INSERTS = 0x00000200;
    pub const FORMAT_MESSAGE_MAX_WIDTH_MASK = 0x000000FF;

    pub const EXCEPTION_DATATYPE_MISALIGNMENT = 0x80000002;
    pub const EXCEPTION_ACCESS_VIOLATION = 0xc0000005;
    pub const EXCEPTION_ILLEGAL_INSTRUCTION = 0xc000001d;
    pub const EXCEPTION_STACK_OVERFLOW = 0xc00000fd;
    pub const EXCEPTION_CONTINUE_SEARCH = 0;

    pub const EXCEPTION_RECORD = extern struct {
        ExceptionCode: u32,
        ExceptionFlags: u32,
        ExceptionRecord: *EXCEPTION_RECORD,
        ExceptionAddress: *anyopaque,
        NumberParameters: u32,
        ExceptionInformation: [15]usize,
    };

    pub usingnamespace switch (native_arch) {
        .i386 => struct {
            pub const FLOATING_SAVE_AREA = extern struct {
                ControlWord: DWORD,
                StatusWord: DWORD,
                TagWord: DWORD,
                ErrorOffset: DWORD,
                ErrorSelector: DWORD,
                DataOffset: DWORD,
                DataSelector: DWORD,
                RegisterArea: [80]BYTE,
                Cr0NpxState: DWORD,
            };

            pub const CONTEXT = extern struct {
                ContextFlags: DWORD,
                Dr0: DWORD,
                Dr1: DWORD,
                Dr2: DWORD,
                Dr3: DWORD,
                Dr6: DWORD,
                Dr7: DWORD,
                FloatSave: FLOATING_SAVE_AREA,
                SegGs: DWORD,
                SegFs: DWORD,
                SegEs: DWORD,
                SegDs: DWORD,
                Edi: DWORD,
                Esi: DWORD,
                Ebx: DWORD,
                Edx: DWORD,
                Ecx: DWORD,
                Eax: DWORD,
                Ebp: DWORD,
                Eip: DWORD,
                SegCs: DWORD,
                EFlags: DWORD,
                Esp: DWORD,
                SegSs: DWORD,
                ExtendedRegisters: [512]BYTE,

                pub fn getRegs(ctx: *const CONTEXT) struct { bp: usize, ip: usize } {
                    return .{ .bp = ctx.Ebp, .ip = ctx.Eip };
                }
            };
        },
        .x86_64 => struct {
            pub const M128A = extern struct {
                Low: ULONGLONG,
                High: LONGLONG,
            };

            pub const XMM_SAVE_AREA32 = extern struct {
                ControlWord: WORD,
                StatusWord: WORD,
                TagWord: BYTE,
                Reserved1: BYTE,
                ErrorOpcode: WORD,
                ErrorOffset: DWORD,
                ErrorSelector: WORD,
                Reserved2: WORD,
                DataOffset: DWORD,
                DataSelector: WORD,
                Reserved3: WORD,
                MxCsr: DWORD,
                MxCsr_Mask: DWORD,
                FloatRegisters: [8]M128A,
                XmmRegisters: [16]M128A,
                Reserved4: [96]BYTE,
            };

            pub const CONTEXT = extern struct {
                P1Home: DWORD64,
                P2Home: DWORD64,
                P3Home: DWORD64,
                P4Home: DWORD64,
                P5Home: DWORD64,
                P6Home: DWORD64,
                ContextFlags: DWORD,
                MxCsr: DWORD,
                SegCs: WORD,
                SegDs: WORD,
                SegEs: WORD,
                SegFs: WORD,
                SegGs: WORD,
                SegSs: WORD,
                EFlags: DWORD,
                Dr0: DWORD64,
                Dr1: DWORD64,
                Dr2: DWORD64,
                Dr3: DWORD64,
                Dr6: DWORD64,
                Dr7: DWORD64,
                Rax: DWORD64,
                Rcx: DWORD64,
                Rdx: DWORD64,
                Rbx: DWORD64,
                Rsp: DWORD64,
                Rbp: DWORD64,
                Rsi: DWORD64,
                Rdi: DWORD64,
                R8: DWORD64,
                R9: DWORD64,
                R10: DWORD64,
                R11: DWORD64,
                R12: DWORD64,
                R13: DWORD64,
                R14: DWORD64,
                R15: DWORD64,
                Rip: DWORD64,
                DUMMYUNIONNAME: extern union {
                    FltSave: XMM_SAVE_AREA32,
                    FloatSave: XMM_SAVE_AREA32,
                    DUMMYSTRUCTNAME: extern struct {
                        Header: [2]M128A,
                        Legacy: [8]M128A,
                        Xmm0: M128A,
                        Xmm1: M128A,
                        Xmm2: M128A,
                        Xmm3: M128A,
                        Xmm4: M128A,
                        Xmm5: M128A,
                        Xmm6: M128A,
                        Xmm7: M128A,
                        Xmm8: M128A,
                        Xmm9: M128A,
                        Xmm10: M128A,
                        Xmm11: M128A,
                        Xmm12: M128A,
                        Xmm13: M128A,
                        Xmm14: M128A,
                        Xmm15: M128A,
                    },
                },
                VectorRegister: [26]M128A,
                VectorControl: DWORD64,
                DebugControl: DWORD64,
                LastBranchToRip: DWORD64,
                LastBranchFromRip: DWORD64,
                LastExceptionToRip: DWORD64,
                LastExceptionFromRip: DWORD64,

                pub fn getRegs(ctx: *const CONTEXT) struct { bp: usize, ip: usize } {
                    return .{ .bp = ctx.Rbp, .ip = ctx.Rip };
                }
            };
        },
        .aarch64 => struct {
            pub const NEON128 = extern union {
                DUMMYSTRUCTNAME: extern struct {
                    Low: ULONGLONG,
                    High: LONGLONG,
                },
                D: [2]f64,
                S: [4]f32,
                H: [8]WORD,
                B: [16]BYTE,
            };

            pub const CONTEXT = extern struct {
                ContextFlags: ULONG,
                Cpsr: ULONG,
                DUMMYUNIONNAME: extern union {
                    DUMMYSTRUCTNAME: extern struct {
                        X0: DWORD64,
                        X1: DWORD64,
                        X2: DWORD64,
                        X3: DWORD64,
                        X4: DWORD64,
                        X5: DWORD64,
                        X6: DWORD64,
                        X7: DWORD64,
                        X8: DWORD64,
                        X9: DWORD64,
                        X10: DWORD64,
                        X11: DWORD64,
                        X12: DWORD64,
                        X13: DWORD64,
                        X14: DWORD64,
                        X15: DWORD64,
                        X16: DWORD64,
                        X17: DWORD64,
                        X18: DWORD64,
                        X19: DWORD64,
                        X20: DWORD64,
                        X21: DWORD64,
                        X22: DWORD64,
                        X23: DWORD64,
                        X24: DWORD64,
                        X25: DWORD64,
                        X26: DWORD64,
                        X27: DWORD64,
                        X28: DWORD64,
                        Fp: DWORD64,
                        Lr: DWORD64,
                    },
                    X: [31]DWORD64,
                },
                Sp: DWORD64,
                Pc: DWORD64,
                V: [32]NEON128,
                Fpcr: DWORD,
                Fpsr: DWORD,
                Bcr: [8]DWORD,
                Bvr: [8]DWORD64,
                Wcr: [2]DWORD,
                Wvr: [2]DWORD64,

                pub fn getRegs(ctx: *const CONTEXT) struct { bp: usize, ip: usize } {
                    return .{
                        .bp = ctx.DUMMYUNIONNAME.DUMMYSTRUCTNAME.Fp,
                        .ip = ctx.Pc,
                    };
                }
            };
        },
        else => struct {},
    };

    pub const EXCEPTION_POINTERS = extern struct {
        ExceptionRecord: *EXCEPTION_RECORD,
        ContextRecord: *std.os.windows.CONTEXT,
    };

    pub const VECTORED_EXCEPTION_HANDLER = std.meta.FnPtr(fn (ExceptionInfo: *EXCEPTION_POINTERS) callconv(WINAPI) c_long);

    pub const OBJECT_ATTRIBUTES = extern struct {
        Length: ULONG,
        RootDirectory: ?HANDLE,
        ObjectName: *UNICODE_STRING,
        Attributes: ULONG,
        SecurityDescriptor: ?*anyopaque,
        SecurityQualityOfService: ?*anyopaque,
    };

    pub const OBJ_INHERIT = 0x00000002;
    pub const OBJ_PERMANENT = 0x00000010;
    pub const OBJ_EXCLUSIVE = 0x00000020;
    pub const OBJ_CASE_INSENSITIVE = 0x00000040;
    pub const OBJ_OPENIF = 0x00000080;
    pub const OBJ_OPENLINK = 0x00000100;
    pub const OBJ_KERNEL_HANDLE = 0x00000200;
    pub const OBJ_VALID_ATTRIBUTES = 0x000003F2;

    pub const UNICODE_STRING = extern struct {
        Length: c_ushort,
        MaximumLength: c_ushort,
        Buffer: [*]WCHAR,
    };

    pub const ACTIVATION_CONTEXT_DATA = opaque {};
    pub const ASSEMBLY_STORAGE_MAP = opaque {};
    pub const FLS_CALLBACK_INFO = opaque {};
    pub const RTL_BITMAP = opaque {};
    pub const KAFFINITY = usize;

    pub const TEB = extern struct {
        Reserved1: [12]PVOID,
        ProcessEnvironmentBlock: *PEB,
        Reserved2: [399]PVOID,
        Reserved3: [1952]u8,
        TlsSlots: [64]PVOID,
        Reserved4: [8]u8,
        Reserved5: [26]PVOID,
        ReservedForOle: PVOID,
        Reserved6: [4]PVOID,
        TlsExpansionSlots: PVOID,
    };

    /// Process Environment Block
    /// Microsoft documentation of this is incomplete, the fields here are taken from various resources including:
    ///  - https://github.com/wine-mirror/wine/blob/1aff1e6a370ee8c0213a0fd4b220d121da8527aa/include/winternl.h#L269
    ///  - https://www.geoffchappell.com/studies/windows/win32/ntdll/structs/peb/index.htm
    pub const PEB = extern struct {
        // Versions: All

        InheritedAddressSpace: BOOLEAN,

        // Versions: 3.51+

        ReadImageFileExecOptions: BOOLEAN,
        BeingDebugged: BOOLEAN,

        // Versions: 5.2+ (previously was padding)

        BitField: UCHAR,

        // Versions: all

        Mutant: HANDLE,
        ImageBaseAddress: HMODULE,
        Ldr: *PEB_LDR_DATA,
        ProcessParameters: *RTL_USER_PROCESS_PARAMETERS,
        SubSystemData: PVOID,
        ProcessHeap: HANDLE,

        // Versions: 5.1+

        FastPebLock: *RTL_CRITICAL_SECTION,

        // Versions: 5.2+

        AtlThunkSListPtr: PVOID,
        IFEOKey: PVOID,

        // Versions: 6.0+

        /// https://www.geoffchappell.com/studies/windows/win32/ntdll/structs/peb/crossprocessflags.htm
        CrossProcessFlags: ULONG,

        // Versions: 6.0+

        union1: extern union {
            KernelCallbackTable: PVOID,
            UserSharedInfoPtr: PVOID,
        },

        // Versions: 5.1+

        SystemReserved: ULONG,

        // Versions: 5.1, (not 5.2, not 6.0), 6.1+

        AtlThunkSListPtr32: ULONG,

        // Versions: 6.1+

        ApiSetMap: PVOID,

        // Versions: all

        TlsExpansionCounter: ULONG,
        // note: there is padding here on 64 bit

        TlsBitmap: *RTL_BITMAP,
        TlsBitmapBits: [2]ULONG,
        ReadOnlySharedMemoryBase: PVOID,

        // Versions: 1703+

        SharedData: PVOID,

        // Versions: all

        ReadOnlyStaticServerData: *PVOID,
        AnsiCodePageData: PVOID,
        OemCodePageData: PVOID,
        UnicodeCaseTableData: PVOID,

        // Versions: 3.51+

        NumberOfProcessors: ULONG,
        NtGlobalFlag: ULONG,

        // Versions: all

        CriticalSectionTimeout: LARGE_INTEGER,

        // End of Original PEB size

        // Fields appended in 3.51:

        HeapSegmentReserve: ULONG_PTR,
        HeapSegmentCommit: ULONG_PTR,
        HeapDeCommitTotalFreeThreshold: ULONG_PTR,
        HeapDeCommitFreeBlockThreshold: ULONG_PTR,
        NumberOfHeaps: ULONG,
        MaximumNumberOfHeaps: ULONG,
        ProcessHeaps: *PVOID,

        // Fields appended in 4.0:

        GdiSharedHandleTable: PVOID,
        ProcessStarterHelper: PVOID,
        GdiDCAttributeList: ULONG,
        // note: there is padding here on 64 bit

        LoaderLock: *RTL_CRITICAL_SECTION,
        OSMajorVersion: ULONG,
        OSMinorVersion: ULONG,
        OSBuildNumber: USHORT,
        OSCSDVersion: USHORT,
        OSPlatformId: ULONG,
        ImageSubSystem: ULONG,
        ImageSubSystemMajorVersion: ULONG,
        ImageSubSystemMinorVersion: ULONG,
        // note: there is padding here on 64 bit

        ActiveProcessAffinityMask: KAFFINITY,
        GdiHandleBuffer: [
            switch (@sizeOf(usize)) {
                4 => 0x22,
                8 => 0x3C,
                else => unreachable,
            }
        ]ULONG,

        // Fields appended in 5.0 (Windows 2000):

        PostProcessInitRoutine: PVOID,
        TlsExpansionBitmap: *RTL_BITMAP,
        TlsExpansionBitmapBits: [32]ULONG,
        SessionId: ULONG,
        // note: there is padding here on 64 bit

        // Versions: 5.1+

        AppCompatFlags: ULARGE_INTEGER,
        AppCompatFlagsUser: ULARGE_INTEGER,
        ShimData: PVOID,
        // Versions: 5.0+

        AppCompatInfo: PVOID,
        CSDVersion: UNICODE_STRING,

        // Fields appended in 5.1 (Windows XP):

        ActivationContextData: *const ACTIVATION_CONTEXT_DATA,
        ProcessAssemblyStorageMap: *ASSEMBLY_STORAGE_MAP,
        SystemDefaultActivationData: *const ACTIVATION_CONTEXT_DATA,
        SystemAssemblyStorageMap: *ASSEMBLY_STORAGE_MAP,
        MinimumStackCommit: ULONG_PTR,

        // Fields appended in 5.2 (Windows Server 2003):

        FlsCallback: *FLS_CALLBACK_INFO,
        FlsListHead: LIST_ENTRY,
        FlsBitmap: *RTL_BITMAP,
        FlsBitmapBits: [4]ULONG,
        FlsHighIndex: ULONG,

        // Fields appended in 6.0 (Windows Vista):

        WerRegistrationData: PVOID,
        WerShipAssertPtr: PVOID,

        // Fields appended in 6.1 (Windows 7):

        pUnused: PVOID, // previously pContextData

        pImageHeaderHash: PVOID,

        /// TODO: https://www.geoffchappell.com/studies/windows/win32/ntdll/structs/peb/tracingflags.htm
        TracingFlags: ULONG,

        // Fields appended in 6.2 (Windows 8):

        CsrServerReadOnlySharedMemoryBase: ULONGLONG,

        // Fields appended in 1511:

        TppWorkerpListLock: ULONG,
        TppWorkerpList: LIST_ENTRY,
        WaitOnAddressHashTable: [0x80]PVOID,

        // Fields appended in 1709:

        TelemetryCoverageHeader: PVOID,
        CloudFileFlags: ULONG,
    };

    /// The `PEB_LDR_DATA` structure is the main record of what modules are loaded in a process.
    /// It is essentially the head of three double-linked lists of `LDR_DATA_TABLE_ENTRY` structures which each represent one loaded module.
    ///
    /// Microsoft documentation of this is incomplete, the fields here are taken from various resources including:
    ///  - https://www.geoffchappell.com/studies/windows/win32/ntdll/structs/peb_ldr_data.htm
    pub const PEB_LDR_DATA = extern struct {
        // Versions: 3.51 and higher

        /// The size in bytes of the structure
        Length: ULONG,

        /// TRUE if the structure is prepared.
        Initialized: BOOLEAN,

        SsHandle: PVOID,
        InLoadOrderModuleList: LIST_ENTRY,
        InMemoryOrderModuleList: LIST_ENTRY,
        InInitializationOrderModuleList: LIST_ENTRY,

        // Versions: 5.1 and higher

        /// No known use of this field is known in Windows 8 and higher.
        EntryInProgress: PVOID,

        // Versions: 6.0 from Windows Vista SP1, and higher

        ShutdownInProgress: BOOLEAN,

        /// Though ShutdownThreadId is declared as a HANDLE,
        /// it is indeed the thread ID as suggested by its name.
        /// It is picked up from the UniqueThread member of the CLIENT_ID in the
        /// TEB of the thread that asks to terminate the process.
        ShutdownThreadId: HANDLE,
    };

    pub const RTL_USER_PROCESS_PARAMETERS = extern struct {
        AllocationSize: ULONG,
        Size: ULONG,
        Flags: ULONG,
        DebugFlags: ULONG,
        ConsoleHandle: HANDLE,
        ConsoleFlags: ULONG,
        hStdInput: HANDLE,
        hStdOutput: HANDLE,
        hStdError: HANDLE,
        CurrentDirectory: CURDIR,
        DllPath: UNICODE_STRING,
        ImagePathName: UNICODE_STRING,
        CommandLine: UNICODE_STRING,
        Environment: [*:0]WCHAR,
        dwX: ULONG,
        dwY: ULONG,
        dwXSize: ULONG,
        dwYSize: ULONG,
        dwXCountChars: ULONG,
        dwYCountChars: ULONG,
        dwFillAttribute: ULONG,
        dwFlags: ULONG,
        dwShowWindow: ULONG,
        WindowTitle: UNICODE_STRING,
        Desktop: UNICODE_STRING,
        ShellInfo: UNICODE_STRING,
        RuntimeInfo: UNICODE_STRING,
        DLCurrentDirectory: [0x20]RTL_DRIVE_LETTER_CURDIR,
    };

    pub const RTL_DRIVE_LETTER_CURDIR = extern struct {
        Flags: c_ushort,
        Length: c_ushort,
        TimeStamp: ULONG,
        DosPath: UNICODE_STRING,
    };

    pub const PPS_POST_PROCESS_INIT_ROUTINE = ?std.meta.FnPtr(fn () callconv(.C) void);

    pub const FILE_BOTH_DIR_INFORMATION = extern struct {
        NextEntryOffset: ULONG,
        FileIndex: ULONG,
        CreationTime: LARGE_INTEGER,
        LastAccessTime: LARGE_INTEGER,
        LastWriteTime: LARGE_INTEGER,
        ChangeTime: LARGE_INTEGER,
        EndOfFile: LARGE_INTEGER,
        AllocationSize: LARGE_INTEGER,
        FileAttributes: ULONG,
        FileNameLength: ULONG,
        EaSize: ULONG,
        ShortNameLength: CHAR,
        ShortName: [12]WCHAR,
        FileName: [1]WCHAR,
    };
    pub const FILE_BOTH_DIRECTORY_INFORMATION = FILE_BOTH_DIR_INFORMATION;

    pub const IO_APC_ROUTINE = std.meta.FnPtr(fn (PVOID, *IO_STATUS_BLOCK, ULONG) callconv(.C) void);

    pub const CURDIR = extern struct {
        DosPath: UNICODE_STRING,
        Handle: HANDLE,
    };

    pub const DUPLICATE_SAME_ACCESS = 2;

    pub const MODULEINFO = extern struct {
        lpBaseOfDll: LPVOID,
        SizeOfImage: DWORD,
        EntryPoint: LPVOID,
    };

    pub const PSAPI_WS_WATCH_INFORMATION = extern struct {
        FaultingPc: LPVOID,
        FaultingVa: LPVOID,
    };

    pub const PROCESS_MEMORY_COUNTERS = extern struct {
        cb: DWORD,
        PageFaultCount: DWORD,
        PeakWorkingSetSize: SIZE_T,
        WorkingSetSize: SIZE_T,
        QuotaPeakPagedPoolUsage: SIZE_T,
        QuotaPagedPoolUsage: SIZE_T,
        QuotaPeakNonPagedPoolUsage: SIZE_T,
        QuotaNonPagedPoolUsage: SIZE_T,
        PagefileUsage: SIZE_T,
        PeakPagefileUsage: SIZE_T,
    };

    pub const PROCESS_MEMORY_COUNTERS_EX = extern struct {
        cb: DWORD,
        PageFaultCount: DWORD,
        PeakWorkingSetSize: SIZE_T,
        WorkingSetSize: SIZE_T,
        QuotaPeakPagedPoolUsage: SIZE_T,
        QuotaPagedPoolUsage: SIZE_T,
        QuotaPeakNonPagedPoolUsage: SIZE_T,
        QuotaNonPagedPoolUsage: SIZE_T,
        PagefileUsage: SIZE_T,
        PeakPagefileUsage: SIZE_T,
        PrivateUsage: SIZE_T,
    };

    pub const PERFORMANCE_INFORMATION = extern struct {
        cb: DWORD,
        CommitTotal: SIZE_T,
        CommitLimit: SIZE_T,
        CommitPeak: SIZE_T,
        PhysicalTotal: SIZE_T,
        PhysicalAvailable: SIZE_T,
        SystemCache: SIZE_T,
        KernelTotal: SIZE_T,
        KernelPaged: SIZE_T,
        KernelNonpaged: SIZE_T,
        PageSize: SIZE_T,
        HandleCount: DWORD,
        ProcessCount: DWORD,
        ThreadCount: DWORD,
    };

    pub const ENUM_PAGE_FILE_INFORMATION = extern struct {
        cb: DWORD,
        Reserved: DWORD,
        TotalSize: SIZE_T,
        TotalInUse: SIZE_T,
        PeakUsage: SIZE_T,
    };

    pub const PENUM_PAGE_FILE_CALLBACKW = ?std.meta.FnPtr(fn (?LPVOID, *ENUM_PAGE_FILE_INFORMATION, LPCWSTR) callconv(.C) BOOL);
    pub const PENUM_PAGE_FILE_CALLBACKA = ?std.meta.FnPtr(fn (?LPVOID, *ENUM_PAGE_FILE_INFORMATION, LPCSTR) callconv(.C) BOOL);

    pub const PSAPI_WS_WATCH_INFORMATION_EX = extern struct {
        BasicInfo: PSAPI_WS_WATCH_INFORMATION,
        FaultingThreadId: ULONG_PTR,
        Flags: ULONG_PTR,
    };

    pub const OSVERSIONINFOW = extern struct {
        dwOSVersionInfoSize: ULONG,
        dwMajorVersion: ULONG,
        dwMinorVersion: ULONG,
        dwBuildNumber: ULONG,
        dwPlatformId: ULONG,
        szCSDVersion: [128]WCHAR,
    };
    pub const RTL_OSVERSIONINFOW = OSVERSIONINFOW;

    pub const REPARSE_DATA_BUFFER = extern struct {
        ReparseTag: ULONG,
        ReparseDataLength: USHORT,
        Reserved: USHORT,
        DataBuffer: [1]UCHAR,
    };
    pub const SYMBOLIC_LINK_REPARSE_BUFFER = extern struct {
        SubstituteNameOffset: USHORT,
        SubstituteNameLength: USHORT,
        PrintNameOffset: USHORT,
        PrintNameLength: USHORT,
        Flags: ULONG,
        PathBuffer: [1]WCHAR,
    };
    pub const MOUNT_POINT_REPARSE_BUFFER = extern struct {
        SubstituteNameOffset: USHORT,
        SubstituteNameLength: USHORT,
        PrintNameOffset: USHORT,
        PrintNameLength: USHORT,
        PathBuffer: [1]WCHAR,
    };
    pub const MAXIMUM_REPARSE_DATA_BUFFER_SIZE: ULONG = 16 * 1024;
    pub const FSCTL_SET_REPARSE_POINT: DWORD = 0x900a4;
    pub const FSCTL_GET_REPARSE_POINT: DWORD = 0x900a8;
    pub const IO_REPARSE_TAG_SYMLINK: ULONG = 0xa000000c;
    pub const IO_REPARSE_TAG_MOUNT_POINT: ULONG = 0xa0000003;
    pub const SYMLINK_FLAG_RELATIVE: ULONG = 0x1;

    pub const SYMBOLIC_LINK_FLAG_DIRECTORY: DWORD = 0x1;
    pub const SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE: DWORD = 0x2;

    pub const MOUNTMGR_MOUNT_POINT = extern struct {
        SymbolicLinkNameOffset: ULONG,
        SymbolicLinkNameLength: USHORT,
        Reserved1: USHORT,
        UniqueIdOffset: ULONG,
        UniqueIdLength: USHORT,
        Reserved2: USHORT,
        DeviceNameOffset: ULONG,
        DeviceNameLength: USHORT,
        Reserved3: USHORT,
    };
    pub const MOUNTMGR_MOUNT_POINTS = extern struct {
        Size: ULONG,
        NumberOfMountPoints: ULONG,
        MountPoints: [1]MOUNTMGR_MOUNT_POINT,
    };
    pub const IOCTL_MOUNTMGR_QUERY_POINTS: ULONG = 0x6d0008;

    pub const OBJECT_INFORMATION_CLASS = enum(c_int) {
        ObjectBasicInformation = 0,
        ObjectNameInformation = 1,
        ObjectTypeInformation = 2,
        ObjectTypesInformation = 3,
        ObjectHandleFlagInformation = 4,
        ObjectSessionInformation = 5,
        MaxObjectInfoClass,
    };

    pub const OBJECT_NAME_INFORMATION = extern struct {
        Name: UNICODE_STRING,
    };

    pub const SRWLOCK_INIT = SRWLOCK{};
    pub const SRWLOCK = extern struct {
        Ptr: ?PVOID = null,
    };

    pub const CONDITION_VARIABLE_INIT = CONDITION_VARIABLE{};
    pub const CONDITION_VARIABLE = extern struct {
        Ptr: ?PVOID = null,
    };

    pub const FILE_SKIP_COMPLETION_PORT_ON_SUCCESS = 0x1;
    pub const FILE_SKIP_SET_EVENT_ON_HANDLE = 0x2;

    pub const CTRL_C_EVENT: DWORD = 0;
    pub const CTRL_BREAK_EVENT: DWORD = 1;
    pub const CTRL_CLOSE_EVENT: DWORD = 2;
    pub const CTRL_LOGOFF_EVENT: DWORD = 5;
    pub const CTRL_SHUTDOWN_EVENT: DWORD = 6;

    pub const HANDLER_ROUTINE = std.meta.FnPtr(fn (dwCtrlType: DWORD) callconv(WINAPI) BOOL);

    /// Processor feature enumeration.
    pub const PF = enum(DWORD) {
        /// On a Pentium, a floating-point precision error can occur in rare circumstances.
        FLOATING_POINT_PRECISION_ERRATA = 0,

        /// Floating-point operations are emulated using software emulator.
        /// This function returns a nonzero value if floating-point operations are emulated; otherwise, it returns zero.
        FLOATING_POINT_EMULATED = 1,

        /// The atomic compare and exchange operation (cmpxchg) is available.
        COMPARE_EXCHANGE_DOUBLE = 2,

        /// The MMX instruction set is available.
        MMX_INSTRUCTIONS_AVAILABLE = 3,

        PPC_MOVEMEM_64BIT_OK = 4,
        ALPHA_BYTE_INSTRUCTIONS = 5,

        /// The SSE instruction set is available.
        XMMI_INSTRUCTIONS_AVAILABLE = 6,

        /// The 3D-Now instruction is available.
        @"3DNOW_INSTRUCTIONS_AVAILABLE" = 7,

        /// The RDTSC instruction is available.
        RDTSC_INSTRUCTION_AVAILABLE = 8,

        /// The processor is PAE-enabled.
        PAE_ENABLED = 9,

        /// The SSE2 instruction set is available.
        XMMI64_INSTRUCTIONS_AVAILABLE = 10,

        SSE_DAZ_MODE_AVAILABLE = 11,

        /// Data execution prevention is enabled.
        NX_ENABLED = 12,

        /// The SSE3 instruction set is available.
        SSE3_INSTRUCTIONS_AVAILABLE = 13,

        /// The atomic compare and exchange 128-bit operation (cmpxchg16b) is available.
        COMPARE_EXCHANGE128 = 14,

        /// The atomic compare 64 and exchange 128-bit operation (cmp8xchg16) is available.
        COMPARE64_EXCHANGE128 = 15,

        /// The processor channels are enabled.
        CHANNELS_ENABLED = 16,

        /// The processor implements the XSAVI and XRSTOR instructions.
        XSAVE_ENABLED = 17,

        /// The VFP/Neon: 32 x 64bit register bank is present.
        /// This flag has the same meaning as PF_ARM_VFP_EXTENDED_REGISTERS.
        ARM_VFP_32_REGISTERS_AVAILABLE = 18,

        /// This ARM processor implements the ARM v8 NEON instruction set.
        ARM_NEON_INSTRUCTIONS_AVAILABLE = 19,

        /// Second Level Address Translation is supported by the hardware.
        SECOND_LEVEL_ADDRESS_TRANSLATION = 20,

        /// Virtualization is enabled in the firmware and made available by the operating system.
        VIRT_FIRMWARE_ENABLED = 21,

        /// RDFSBASE, RDGSBASE, WRFSBASE, and WRGSBASE instructions are available.
        RDWRFSGBASE_AVAILABLE = 22,

        /// _fastfail() is available.
        FASTFAIL_AVAILABLE = 23,

        /// The divide instruction_available.
        ARM_DIVIDE_INSTRUCTION_AVAILABLE = 24,

        /// The 64-bit load/store atomic instructions are available.
        ARM_64BIT_LOADSTORE_ATOMIC = 25,

        /// The external cache is available.
        ARM_EXTERNAL_CACHE_AVAILABLE = 26,

        /// The floating-point multiply-accumulate instruction is available.
        ARM_FMAC_INSTRUCTIONS_AVAILABLE = 27,

        RDRAND_INSTRUCTION_AVAILABLE = 28,

        /// This ARM processor implements the ARM v8 instructions set.
        ARM_V8_INSTRUCTIONS_AVAILABLE = 29,

        /// This ARM processor implements the ARM v8 extra cryptographic instructions (i.e., AES, SHA1 and SHA2).
        ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE = 30,

        /// This ARM processor implements the ARM v8 extra CRC32 instructions.
        ARM_V8_CRC32_INSTRUCTIONS_AVAILABLE = 31,

        RDTSCP_INSTRUCTION_AVAILABLE = 32,
        RDPID_INSTRUCTION_AVAILABLE = 33,

        /// This ARM processor implements the ARM v8.1 atomic instructions (e.g., CAS, SWP).
        ARM_V81_ATOMIC_INSTRUCTIONS_AVAILABLE = 34,

        MONITORX_INSTRUCTION_AVAILABLE = 35,

        /// The SSSE3 instruction set is available.
        SSSE3_INSTRUCTIONS_AVAILABLE = 36,

        /// The SSE4_1 instruction set is available.
        SSE4_1_INSTRUCTIONS_AVAILABLE = 37,

        /// The SSE4_2 instruction set is available.
        SSE4_2_INSTRUCTIONS_AVAILABLE = 38,

        /// The AVX instruction set is available.
        AVX_INSTRUCTIONS_AVAILABLE = 39,

        /// The AVX2 instruction set is available.
        AVX2_INSTRUCTIONS_AVAILABLE = 40,

        /// The AVX512F instruction set is available.
        AVX512F_INSTRUCTIONS_AVAILABLE = 41,

        ERMS_AVAILABLE = 42,

        /// This ARM processor implements the ARM v8.2 Dot Product (DP) instructions.
        ARM_V82_DP_INSTRUCTIONS_AVAILABLE = 43,

        /// This ARM processor implements the ARM v8.3 JavaScript conversion (JSCVT) instructions.
        ARM_V83_JSCVT_INSTRUCTIONS_AVAILABLE = 44,
    };

    pub const MAX_WOW64_SHARED_ENTRIES = 16;
    pub const PROCESSOR_FEATURE_MAX = 64;
    pub const MAXIMUM_XSTATE_FEATURES = 64;

    pub const KSYSTEM_TIME = extern struct {
        LowPart: ULONG,
        High1Time: LONG,
        High2Time: LONG,
    };

    pub const NT_PRODUCT_TYPE = enum(INT) {
        NtProductWinNt = 1,
        NtProductLanManNt,
        NtProductServer,
    };

    pub const ALTERNATIVE_ARCHITECTURE_TYPE = enum(INT) {
        StandardDesign,
        NEC98x86,
        EndAlternatives,
    };

    pub const XSTATE_FEATURE = extern struct {
        Offset: ULONG,
        Size: ULONG,
    };

    pub const XSTATE_CONFIGURATION = extern struct {
        EnabledFeatures: ULONG64,
        Size: ULONG,
        OptimizedSave: ULONG,
        Features: [MAXIMUM_XSTATE_FEATURES]XSTATE_FEATURE,
    };

    /// Shared Kernel User Data
    pub const KUSER_SHARED_DATA = extern struct {
        TickCountLowDeprecated: ULONG,
        TickCountMultiplier: ULONG,
        InterruptTime: KSYSTEM_TIME,
        SystemTime: KSYSTEM_TIME,
        TimeZoneBias: KSYSTEM_TIME,
        ImageNumberLow: USHORT,
        ImageNumberHigh: USHORT,
        NtSystemRoot: [260]WCHAR,
        MaxStackTraceDepth: ULONG,
        CryptoExponent: ULONG,
        TimeZoneId: ULONG,
        LargePageMinimum: ULONG,
        AitSamplingValue: ULONG,
        AppCompatFlag: ULONG,
        RNGSeedVersion: ULONGLONG,
        GlobalValidationRunlevel: ULONG,
        TimeZoneBiasStamp: LONG,
        NtBuildNumber: ULONG,
        NtProductType: NT_PRODUCT_TYPE,
        ProductTypeIsValid: BOOLEAN,
        Reserved0: [1]BOOLEAN,
        NativeProcessorArchitecture: USHORT,
        NtMajorVersion: ULONG,
        NtMinorVersion: ULONG,
        ProcessorFeatures: [PROCESSOR_FEATURE_MAX]BOOLEAN,
        Reserved1: ULONG,
        Reserved3: ULONG,
        TimeSlip: ULONG,
        AlternativeArchitecture: ALTERNATIVE_ARCHITECTURE_TYPE,
        BootId: ULONG,
        SystemExpirationDate: LARGE_INTEGER,
        SuiteMaskY: ULONG,
        KdDebuggerEnabled: BOOLEAN,
        DummyUnion1: extern union {
            MitigationPolicies: UCHAR,
            Alt: packed struct {
                NXSupportPolicy: u2,
                SEHValidationPolicy: u2,
                CurDirDevicesSkippedForDlls: u2,
                Reserved: u2,
            },
        },
        CyclesPerYield: USHORT,
        ActiveConsoleId: ULONG,
        DismountCount: ULONG,
        ComPlusPackage: ULONG,
        LastSystemRITEventTickCount: ULONG,
        NumberOfPhysicalPages: ULONG,
        SafeBootMode: BOOLEAN,
        DummyUnion2: extern union {
            VirtualizationFlags: UCHAR,
            Alt: packed struct {
                ArchStartedInEl2: u1,
                QcSlIsSupported: u1,
                SpareBits: u6,
            },
        },
        Reserved12: [2]UCHAR,
        DummyUnion3: extern union {
            SharedDataFlags: ULONG,
            Alt: packed struct {
                DbgErrorPortPresent: u1,
                DbgElevationEnabled: u1,
                DbgVirtEnabled: u1,
                DbgInstallerDetectEnabled: u1,
                DbgLkgEnabled: u1,
                DbgDynProcessorEnabled: u1,
                DbgConsoleBrokerEnabled: u1,
                DbgSecureBootEnabled: u1,
                DbgMultiSessionSku: u1,
                DbgMultiUsersInSessionSku: u1,
                DbgStateSeparationEnabled: u1,
                SpareBits: u21,
            },
        },
        DataFlagsPad: [1]ULONG,
        TestRetInstruction: ULONGLONG,
        QpcFrequency: LONGLONG,
        SystemCall: ULONG,
        Reserved2: ULONG,
        SystemCallPad: [2]ULONGLONG,
        DummyUnion4: extern union {
            TickCount: KSYSTEM_TIME,
            TickCountQuad: ULONG64,
            Alt: extern struct {
                ReservedTickCountOverlay: [3]ULONG,
                TickCountPad: [1]ULONG,
            },
        },
        Cookie: ULONG,
        CookiePad: [1]ULONG,
        ConsoleSessionForegroundProcessId: LONGLONG,
        TimeUpdateLock: ULONGLONG,
        BaselineSystemTimeQpc: ULONGLONG,
        BaselineInterruptTimeQpc: ULONGLONG,
        QpcSystemTimeIncrement: ULONGLONG,
        QpcInterruptTimeIncrement: ULONGLONG,
        QpcSystemTimeIncrementShift: UCHAR,
        QpcInterruptTimeIncrementShift: UCHAR,
        UnparkedProcessorCount: USHORT,
        EnclaveFeatureMask: [4]ULONG,
        TelemetryCoverageRound: ULONG,
        UserModeGlobalLogger: [16]USHORT,
        ImageFileExecutionOptions: ULONG,
        LangGenerationCount: ULONG,
        Reserved4: ULONGLONG,
        InterruptTimeBias: ULONGLONG,
        QpcBias: ULONGLONG,
        ActiveProcessorCount: ULONG,
        ActiveGroupCount: UCHAR,
        Reserved9: UCHAR,
        DummyUnion5: extern union {
            QpcData: USHORT,
            Alt: extern struct {
                QpcBypassEnabled: UCHAR,
                QpcShift: UCHAR,
            },
        },
        TimeZoneBiasEffectiveStart: LARGE_INTEGER,
        TimeZoneBiasEffectiveEnd: LARGE_INTEGER,
        XState: XSTATE_CONFIGURATION,
        FeatureConfigurationChangeStamp: KSYSTEM_TIME,
        Spare: ULONG,
        UserPointerAuthMask: ULONG64,
    };

    /// Read-only user-mode address for the shared data.
    /// https://www.geoffchappell.com/studies/windows/km/ntoskrnl/inc/api/ntexapi_x/kuser_shared_data/index.htm
    /// https://msrc-blog.microsoft.com/2022/04/05/randomizing-the-kuser_shared_data-structure-on-windows/
    pub const SharedUserData: *const KUSER_SHARED_DATA = @intToPtr(*const KUSER_SHARED_DATA, 0x7FFE0000);

    pub fn IsProcessorFeaturePresent(feature: PF) bool {
        if (@enumToInt(feature) >= PROCESSOR_FEATURE_MAX) return false;
        return SharedUserData.ProcessorFeatures[@enumToInt(feature)] == 1;
    }