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std/os/uefi: Refactor getDevicePath()

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Uses comptime loops over the types instead of writing out a large
switch.
This commit is contained in:
fifty-six
2022-01-14 08:53:56 -05:00
parent a2a2601da5
commit dab4c63684
1 changed files with 34 additions and 61 deletions
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95
lib/std/os/uefi/protocols/device_path_protocol.zig
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@@ -72,66 +72,39 @@ pub const DevicePathProtocol = packed struct {
}
pub fn getDevicePath(self: *const DevicePathProtocol) ?DevicePath {
return switch (self.type) {
.Hardware => blk: {
const hardware: ?HardwareDevicePath = switch (@intToEnum(HardwareDevicePath.Subtype, self.subtype)) {
.Pci => .{ .Pci = @ptrCast(*const HardwareDevicePath.PciDevicePath, self) },
.PcCard => .{ .PcCard = @ptrCast(*const HardwareDevicePath.PcCardDevicePath, self) },
.MemoryMapped => .{ .MemoryMapped = @ptrCast(*const HardwareDevicePath.MemoryMappedDevicePath, self) },
.Vendor => .{ .Vendor = @ptrCast(*const HardwareDevicePath.VendorDevicePath, self) },
.Controller => .{ .Controller = @ptrCast(*const HardwareDevicePath.ControllerDevicePath, self) },
.Bmc => .{ .Bmc = @ptrCast(*const HardwareDevicePath.BmcDevicePath, self) },
_ => null,
};
break :blk if (hardware) |h| .{ .Hardware = h } else null;
},
.Acpi => blk: {
const acpi: ?AcpiDevicePath = switch (@intToEnum(AcpiDevicePath.Subtype, self.subtype)) {
.Acpi => .{ .Acpi = @ptrCast(*const AcpiDevicePath.BaseAcpiDevicePath, self) },
.ExpandedAcpi => .{ .ExpandedAcpi = @ptrCast(*const AcpiDevicePath.ExpandedAcpiDevicePath, self) },
.Adr => .{ .Adr = @ptrCast(*const AcpiDevicePath.AdrDevicePath, self) },
_ => null,
};
break :blk if (acpi) |a| .{ .Acpi = a } else null;
},
.Messaging => blk: {
const messaging: ?MessagingDevicePath = switch (@intToEnum(MessagingDevicePath.Subtype, self.subtype)) {
else => null, // TODO
};
break :blk if (messaging) |m| .{ .Messaging = m } else null;
},
.Media => blk: {
const media: ?MediaDevicePath = switch (@intToEnum(MediaDevicePath.Subtype, self.subtype)) {
.HardDrive => .{ .HardDrive = @ptrCast(*const MediaDevicePath.HardDriveDevicePath, self) },
.Cdrom => .{ .Cdrom = @ptrCast(*const MediaDevicePath.CdromDevicePath, self) },
.Vendor => .{ .Vendor = @ptrCast(*const MediaDevicePath.VendorDevicePath, self) },
.FilePath => .{ .FilePath = @ptrCast(*const MediaDevicePath.FilePathDevicePath, self) },
.MediaProtocol => .{ .MediaProtocol = @ptrCast(*const MediaDevicePath.MediaProtocolDevicePath, self) },
.PiwgFirmwareFile => .{ .PiwgFirmwareFile = @ptrCast(*const MediaDevicePath.PiwgFirmwareFileDevicePath, self) },
.PiwgFirmwareVolume => .{ .PiwgFirmwareVolume = @ptrCast(*const MediaDevicePath.PiwgFirmwareVolumeDevicePath, self) },
.RelativeOffsetRange => .{ .RelativeOffsetRange = @ptrCast(*const MediaDevicePath.RelativeOffsetRangeDevicePath, self) },
.RamDisk => .{ .RamDisk = @ptrCast(*const MediaDevicePath.RamDiskDevicePath, self) },
_ => null,
};
break :blk if (media) |m| .{ .Media = m } else null;
},
.BiosBootSpecification => blk: {
const bbs: ?BiosBootSpecificationDevicePath = switch (@intToEnum(BiosBootSpecificationDevicePath.Subtype, self.subtype)) {
.BBS101 => .{ .BBS101 = @ptrCast(*const BiosBootSpecificationDevicePath.BBS101DevicePath, self) },
_ => null,
};
break :blk if (bbs) |b| .{ .BiosBootSpecification = b } else null;
},
.End => blk: {
const end: ?EndDevicePath = switch (@intToEnum(EndDevicePath.Subtype, self.subtype)) {
.EndEntire => .{ .EndEntire = @ptrCast(*const EndDevicePath.EndEntireDevicePath, self) },
.EndThisInstance => .{ .EndThisInstance = @ptrCast(*const EndDevicePath.EndThisInstanceDevicePath, self) },
_ => null,
};
break :blk if (end) |e| .{ .End = e } else null;
},
_ => null,
};
inline for (@typeInfo(DevicePath).Union.fields) |ufield| {
const enum_value = std.meta.stringToEnum(DevicePathType, ufield.name);
// Got the associated union type for self.type, now
// we need to initialize it and its subtype
if (self.type == enum_value) {
var subtype = self.initSubtype(ufield.field_type);
if (subtype) |sb| {
// e.g. return .{ .Hardware = .{ .Pci = @ptrCast(...) } }
return @unionInit(DevicePath, ufield.name, sb);
}
}
}
return null;
}
pub fn initSubtype(self: *const DevicePathProtocol, comptime TUnion: type) ?TUnion {
const type_info = @typeInfo(TUnion).Union;
const TTag = type_info.tag_type.?;
inline for (type_info.fields) |subtype| {
// The tag names match the union names, so just grab that off the enum
const tag_val: u8 = @enumToInt(@field(TTag, subtype.name));
if (self.subtype == tag_val) {
// e.g. expr = .{ .Pci = @ptrCast(...) }
return @unionInit(TUnion, subtype.name, @ptrCast(subtype.field_type, self));
}
}
return null;
}
};
@@ -268,7 +241,7 @@ pub const MessagingDevicePath = union(Subtype) {
Atapi: *const AtapiDevicePath,
Scsi: *const ScsiDevicePath,
FibreChannel: *const FibreChannelDevicePath,
FibreChannelEx: FibreChannelExDevicePath,
FibreChannelEx: *const FibreChannelExDevicePath,
@"1394": *const F1394DevicePath,
Usb: *const UsbDevicePath,
Sata: *const SataDevicePath,