wry/libinput/build.rs

use {
    repc::layout::{Type, TypeVariant},
    std::{
        env,
        fs::{File, OpenOptions},
        io::{self, BufWriter, Write},
        path::PathBuf,
    },
};

#[allow(unused_macros)]
macro_rules! cenum {
    ($name:ident, $uc:ident; $($name2:ident = $val:expr,)*) => {
        #[derive(Copy, Clone, Debug, Eq, PartialEq)]
        pub struct $name(pub i32);

        impl $name {
            pub fn raw(self) -> i32 {
                self.0
            }
        }

        $(
            pub const $name2: $name = $name($val);
        )*

        pub const $uc: &[i32] = &[$($val,)*];
    };
}

#[path = "src/consts.rs"]
mod consts;

fn open(s: &str) -> io::Result<BufWriter<File>> {
    let mut path = PathBuf::from(env::var("OUT_DIR").unwrap());
    path.push(s);
    Ok(BufWriter::new(
        OpenOptions::new()
            .create(true)
            .write(true)
            .truncate(true)
            .open(path)?,
    ))
}

fn get_target() -> repc::Target {
    let rustc_target = env::var("TARGET").unwrap();
    repc::TARGET_MAP
        .iter()
        .cloned()
        .find(|t| t.0 == rustc_target)
        .unwrap()
        .1
}

fn get_enum_ty(variants: Vec<i128>) -> anyhow::Result<u64> {
    let target = get_target();
    let ty = Type {
        layout: (),
        annotations: vec![],
        variant: TypeVariant::Enum(variants),
    };
    let ty = repc::compute_layout(target, &ty)?;
    assert!(ty.layout.pointer_alignment_bits <= ty.layout.size_bits);
    Ok(ty.layout.size_bits)
}

fn write_ty<W: Write>(f: &mut W, vals: &[i32], ty: &str) -> anyhow::Result<()> {
    let variants: Vec<_> = vals.iter().cloned().map(|v| v as i128).collect();
    let size = get_enum_ty(variants)?;
    writeln!(f, "#[allow(clippy::allow_attributes, dead_code)]")?;
    writeln!(f, "pub type {} = i{};", ty, size)?;
    Ok(())
}

fn main() -> anyhow::Result<()> {
    let mut f = open("libinput_tys.rs")?;
    write_ty(
        &mut f,
        consts::LIBINPUT_LOG_PRIORITY,
        "libinput_log_priority",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_DEVICE_CAPABILITY,
        "libinput_device_capability",
    )?;
    write_ty(&mut f, consts::LIBINPUT_KEY_STATE, "libinput_key_state")?;
    write_ty(&mut f, consts::LIBINPUT_LED, "libinput_led")?;
    write_ty(
        &mut f,
        consts::LIBINPUT_BUTTON_STATE,
        "libinput_button_state",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_POINTER_AXIS,
        "libinput_pointer_axis",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_POINTER_AXIS_SOURCE,
        "libinput_pointer_axis_source",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_TABLET_PAD_RING_AXIS_SOURCE,
        "libinput_tablet_pad_ring_axis_source",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_TABLET_PAD_STRIP_AXIS_SOURCE,
        "libinput_tablet_pad_strip_axis_source",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_TABLET_TOOL_TYPE,
        "libinput_tablet_tool_type",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_TABLET_TOOL_PROXIMITY_STATE,
        "libinput_tablet_tool_proximity_state",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_TABLET_TOOL_TIP_STATE,
        "libinput_tablet_tool_tip_state",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_SWITCH_STATE,
        "libinput_switch_state",
    )?;
    write_ty(&mut f, consts::LIBINPUT_SWITCH, "libinput_switch")?;
    write_ty(&mut f, consts::LIBINPUT_EVENT_TYPE, "libinput_event_type")?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_STATUS,
        "libinput_config_status",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_ACCEL_PROFILE,
        "libinput_config_accel_profile",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_TAP_STATE,
        "libinput_config_tap_state",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_DRAG_STATE,
        "libinput_config_drag_state",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_DRAG_LOCK_STATE,
        "libinput_config_drag_lock_state",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_CLICK_METHOD,
        "libinput_config_click_method",
    )?;
    write_ty(
        &mut f,
        consts::LIBINPUT_CONFIG_MIDDLE_EMULATION_STATE,
        "libinput_config_middle_emulation_state",
    )?;

    println!("cargo:rerun-if-changed=src/consts.rs");
    Ok(())
}