Commit ea7512084bc6f0f18b9dc3d1ecd23599640b3363 | zig

author	Ryan Liptak <squeek502@hotmail.com> 2025-12-10 18:56:14-08:00
committer	Ryan Liptak <squeek502@hotmail.com> 2025-12-14 07:12:38-08:00
log	ea7512084bc6f0f18b9dc3d1ecd23599640b3363
tree	87257ccd9ea9505b21dd954fe910537ee9c0a6d6
parent	c13857e504f5893cabf182dde1e826131f2acf24

Make windows.DeviceIoControl return NTSTATUS instead of a Zig error

The number of possible errors in the theoretical error set of this function is very large, while each individual call to the function is only concerned with a (potentially small) subset of those errors that are specific to the control code being used. This commit makes the callers determine which statuses they are interested in to avoid an ever-ballooning error set and ever-growing switch cases at each call site that throw away most of those errors.

1 files changed, 29 insertions(+), 67 deletions(-)

lib
- std
  - os
    windows.zig

lib/std/os/windows.zig+29-67

 @@ -2574,23 +2574,6 @@ pub fn CreatePipe(rd: *HANDLE, wr: *HANDLE, sattr: *const SECURITY_ATTRIBUTES) C
     wr.* = write;
 }
-pub const DeviceIoControlError = error{
-    AccessDenied,
-    /// The volume does not contain a recognized file system. File system
-    /// drivers might not be loaded, or the volume may be corrupt.
-    UnrecognizedVolume,
-    Pending,
-    /// Attempted to connect a named pipe in the "closing" state, meaning a previous client has
-    /// has closed their handle but we have not yet disconnected the pipe.
-    PipeClosing,
-    /// Attempted to connect a named pipe in the "connected" state, meaning a client has already
-    /// opened the pipe; there is a good connection between client and server.
-    PipeAlreadyConnected,
-    /// Attempted to connect a non-blocking named pipe which is already listening for connections.
-    PipeAlreadyListening,
-    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.
 @@ -2606,9 +2589,9 @@ pub fn DeviceIoControl(
         in: []const u8 = &.{},
         out: []u8 = &.{},
     },
-) DeviceIoControlError!void {
+) NTSTATUS {
     var io_status_block: IO_STATUS_BLOCK = undefined;
-    const rc = switch (io_control_code.DeviceType) {
+    return switch (io_control_code.DeviceType) {
         .FILE_SYSTEM, .NAMED_PIPE => ntdll.NtFsControlFile(
             device,
             opts.event,
 @@ -2634,19 +2617,6 @@ pub fn DeviceIoControl(
             @intCast(opts.out.len),
         ),
     };
-    switch (rc) {
-        .SUCCESS => {},
-        .PIPE_CLOSING => return error.PipeClosing,
-        .PIPE_CONNECTED => return error.PipeAlreadyConnected,
-        .PIPE_LISTENING => return error.PipeAlreadyListening,
-        .PRIVILEGE_NOT_HELD => return error.AccessDenied,
-        .ACCESS_DENIED => return error.AccessDenied,
-        .INVALID_DEVICE_REQUEST => return error.AccessDenied, // Not supported by the underlying filesystem
-        .INVALID_PARAMETER => unreachable,
-        .UNRECOGNIZED_VOLUME => return error.UnrecognizedVolume,
-        .PENDING => return error.Pending,
-        else => return unexpectedStatus(rc),
-    }
 }
 pub fn GetOverlappedResult(h: HANDLE, overlapped: *OVERLAPPED, wait: bool) !DWORD {
 @@ -3037,9 +3007,6 @@ pub const CreateSymbolicLinkError = error{
     NoDevice,
     NetworkNotFound,
     BadPathName,
-    /// The volume does not contain a recognized file system. File system
-    /// drivers might not be loaded, or the volume may be corrupt.
-    UnrecognizedVolume,
     Unexpected,
 };
 @@ -3139,13 +3106,14 @@ pub fn CreateSymbolicLink(
     @memcpy(buffer[@sizeOf(SYMLINK_DATA)..][0 .. final_target_path.len * 2], @as([*]const u8, @ptrCast(final_target_path)));
     const paths_start = @sizeOf(SYMLINK_DATA) + final_target_path.len * 2;
     @memcpy(buffer[paths_start..][0 .. final_target_path.len * 2], @as([*]const u8, @ptrCast(final_target_path)));
-    _ = DeviceIoControl(symlink_handle, FSCTL.SET_REPARSE_POINT, .{ .in = buffer[0..buf_len] }) catch |err| switch (err) {
+    const rc = DeviceIoControl(symlink_handle, FSCTL.SET_REPARSE_POINT, .{ .in = buffer[0..buf_len] });
-        error.PipeClosing => unreachable,
+    switch (rc) {
-        error.PipeAlreadyConnected => unreachable,
+        .SUCCESS => {},
-        error.PipeAlreadyListening => unreachable,
+        .PRIVILEGE_NOT_HELD => return error.AccessDenied,
-        error.Pending => unreachable,
+        .ACCESS_DENIED => return error.AccessDenied,
-        else => |e| return e,
+        .INVALID_DEVICE_REQUEST => return error.AccessDenied, // Not supported by the underlying filesystem
-    };
+        else => return unexpectedStatus(rc),
+    }
 }
 pub const ReadLinkError = error{
 @@ -3184,15 +3152,11 @@ pub fn ReadLink(dir: ?HANDLE, sub_path_w: []const u16, out_buffer: []u16) ReadLi
     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, .{ .out = reparse_buf[0..] }) catch |err| switch (err) {
+    const rc = DeviceIoControl(result_handle, FSCTL.GET_REPARSE_POINT, .{ .out = reparse_buf[0..] });
-        error.PipeClosing => unreachable,
+    switch (rc) {
-        error.PipeAlreadyConnected => unreachable,
+        .SUCCESS => {},
-        error.PipeAlreadyListening => unreachable,
+        else => return unexpectedStatus(rc),
-        error.AccessDenied => return error.Unexpected,
+    }
-        error.UnrecognizedVolume => return error.Unexpected,
-        error.Pending => unreachable,
-        else => |e| return e,
-    };
     const reparse_struct: *const REPARSE_DATA_BUFFER = @ptrCast(@alignCast(&reparse_buf[0]));
     const IoReparseTagInt = @typeInfo(IO_REPARSE_TAG).@"struct".backing_integer.?;
 @@ -3744,14 +3708,14 @@ pub fn GetFinalPathNameByHandle(
             input_struct.DeviceNameLength = @intCast(volume_name_u16.len * 2);
             @memcpy(input_buf[@sizeOf(MOUNTMGR_MOUNT_POINT)..][0 .. volume_name_u16.len * 2], @as([*]const u8, @ptrCast(volume_name_u16.ptr)));
-            DeviceIoControl(mgmt_handle, IOCTL.MOUNTMGR.QUERY_POINTS, .{ .in = &input_buf, .out = &output_buf }) catch |err| switch (err) {
+            {
-                error.PipeClosing => unreachable,
+                const rc = DeviceIoControl(mgmt_handle, IOCTL.MOUNTMGR.QUERY_POINTS, .{ .in = &input_buf, .out = &output_buf });
-                error.PipeAlreadyConnected => unreachable,
+                switch (rc) {
-                error.PipeAlreadyListening => unreachable,
+                    .SUCCESS => {},
-                error.AccessDenied => return error.Unexpected,
+                    .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
-                error.Pending => unreachable,
+                    else => return unexpectedStatus(rc),
-                else => |e| return e,
+                }
-            };
+            }
             const mount_points_struct: *const MOUNTMGR_MOUNT_POINTS = @ptrCast(&output_buf[0]);
             const mount_points = @as(
 @@ -3803,14 +3767,12 @@ pub fn GetFinalPathNameByHandle(
                     vol_input_struct.DeviceNameLength = @intCast(symlink.len * 2);
                     @memcpy(@as([*]WCHAR, &vol_input_struct.DeviceName)[0..symlink.len], symlink);
-                    DeviceIoControl(mgmt_handle, IOCTL.MOUNTMGR.QUERY_DOS_VOLUME_PATH, .{ .in = &vol_input_buf, .out = &vol_output_buf }) catch |err| switch (err) {
+                    const rc = DeviceIoControl(mgmt_handle, IOCTL.MOUNTMGR.QUERY_DOS_VOLUME_PATH, .{ .in = &vol_input_buf, .out = &vol_output_buf });
-                        error.PipeClosing => unreachable,
+                    switch (rc) {
-                        error.PipeAlreadyConnected => unreachable,
+                        .SUCCESS => {},
-                        error.PipeAlreadyListening => unreachable,
+                        .UNRECOGNIZED_VOLUME => return error.UnrecognizedVolume,
-                        error.AccessDenied => return error.Unexpected,
+                        else => return unexpectedStatus(rc),
-                        error.Pending => unreachable,
+                    }
-                        else => |e| return e,
-                    };
                     const volume_paths_struct: *const MOUNTMGR_VOLUME_PATHS = @ptrCast(&vol_output_buf[0]);
                     const volume_path = std.mem.sliceTo(@as(
                         [*]const u16,