rust/example/mini_core.rs

#![feature(no_core, lang_items, intrinsics, unboxed_closures)]
#![no_core]
#![allow(dead_code)]

#[lang = "sized"]
pub trait Sized {}

#[lang = "unsize"]
pub trait Unsize<T: ?Sized> {}

#[lang = "coerce_unsized"]
pub trait CoerceUnsized<T> {}

impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}
impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}

#[lang = "dispatch_from_dyn"]
pub trait DispatchFromDyn<T> {}

// &T -> &U
impl<'a, T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<&'a U> for &'a T {}
// &mut T -> &mut U
impl<'a, T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<&'a mut U> for &'a mut T {}
// *const T -> *const U
impl<T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<*const U> for *const T {}
// *mut T -> *mut U
impl<T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<*mut U> for *mut T {}

#[lang = "copy"]
pub unsafe trait Copy {}

unsafe impl Copy for bool {}
unsafe impl Copy for u8 {}
unsafe impl Copy for u16 {}
unsafe impl Copy for u32 {}
unsafe impl Copy for u64 {}
unsafe impl Copy for usize {}
unsafe impl Copy for i8 {}
unsafe impl Copy for i16 {}
unsafe impl Copy for i32 {}
unsafe impl Copy for isize {}
unsafe impl Copy for char {}
unsafe impl<'a, T: ?Sized> Copy for &'a T {}
unsafe impl<T: ?Sized> Copy for *const T {}

#[lang = "sync"]
pub unsafe trait Sync {}

unsafe impl Sync for bool {}
unsafe impl Sync for u8 {}
unsafe impl Sync for u16 {}
unsafe impl Sync for u32 {}
unsafe impl Sync for u64 {}
unsafe impl Sync for usize {}
unsafe impl Sync for i8 {}
unsafe impl Sync for i16 {}
unsafe impl Sync for i32 {}
unsafe impl Sync for isize {}
unsafe impl Sync for char {}
unsafe impl<'a, T: ?Sized> Sync for &'a T {}
unsafe impl Sync for [u8; 16] {}

#[lang = "freeze"]
trait Freeze {}

#[lang = "not"]
pub trait Not {
    type Output;

    fn not(self) -> Self::Output;
}

impl Not for bool {
    type Output = bool;

    fn not(self) -> bool {
        !self
    }
}

#[lang = "mul"]
pub trait Mul<RHS = Self> {
    type Output;

    #[must_use]
    fn mul(self, rhs: RHS) -> Self::Output;
}

impl Mul for u8 {
    type Output = Self;

    fn mul(self, rhs: Self) -> Self::Output {
        self * rhs
    }
}

#[lang = "add"]
pub trait Add<RHS = Self> {
    type Output;

    fn add(self, rhs: RHS) -> Self::Output;
}

impl Add for u8 {
    type Output = Self;

    fn add(self, rhs: Self) -> Self {
        self + rhs
    }
}

#[lang = "sub"]
pub trait Sub<RHS = Self> {
    type Output;

    fn sub(self, rhs: RHS) -> Self::Output;
}

impl Sub for usize {
    type Output = Self;

    fn sub(self, rhs: Self) -> Self {
        self - rhs
    }
}

#[lang = "bitor"]
pub trait BitOr<RHS = Self> {
    type Output;

    #[must_use]
    fn bitor(self, rhs: RHS) -> Self::Output;
}

impl BitOr for bool {
    type Output = bool;

    fn bitor(self, rhs: bool) -> bool {
        self | rhs
    }
}

impl<'a> BitOr<bool> for &'a bool {
    type Output = bool;

    fn bitor(self, rhs: bool) -> bool {
        *self | rhs
    }
}

#[lang = "eq"]
pub trait PartialEq<Rhs: ?Sized = Self> {
    fn eq(&self, other: &Rhs) -> bool;
    fn ne(&self, other: &Rhs) -> bool;
}

impl PartialEq for u8 {
    fn eq(&self, other: &u8) -> bool {
        (*self) == (*other)
    }
    fn ne(&self, other: &u8) -> bool {
        (*self) != (*other)
    }
}

impl PartialEq for char {
    fn eq(&self, other: &char) -> bool {
        (*self) == (*other)
    }
    fn ne(&self, other: &char) -> bool {
        (*self) != (*other)
    }
}

impl<T: ?Sized> PartialEq for *const T {
    fn eq(&self, other: &*const T) -> bool {
        *self == *other
    }
    fn ne(&self, other: &*const T) -> bool {
        *self != *other
    }
}

#[lang = "neg"]
pub trait Neg {
    type Output;

    fn neg(self) -> Self::Output;
}

impl Neg for isize {
    type Output = isize;

    fn neg(self) -> isize {
        -self
    }
}

pub enum Option<T> {
    Some(T),
    None,
}

pub use Option::*;

#[lang = "phantom_data"]
pub struct PhantomData<T: ?Sized>;

#[lang = "fn_once"]
#[rustc_paren_sugar]
pub trait FnOnce<Args> {
    type Output;

    extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
}

#[lang = "fn_mut"]
#[rustc_paren_sugar]
pub trait FnMut<Args>: FnOnce<Args> {
    extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output;
}

#[lang = "panic"]
pub fn panic(_expr_file_line_col: &(&'static str, &'static str, u32, u32)) -> ! {
    unsafe {
        intrinsics::abort();
    }
}

#[lang = "eh_personality"]
fn eh_personality() -> ! {
    loop {}
}

#[lang = "drop_in_place"]
#[allow(unconditional_recursion)]
pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
    // Code here does not matter - this is replaced by the
    // real drop glue by the compiler.
    drop_in_place(to_drop);
}

#[lang = "owned_box"]
pub struct Box<T: ?Sized>(*mut T);

impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Box<U>> for Box<T> {}

static mut MY_TINY_HEAP: [u8; 16] = [0; 16];

#[lang = "exchange_malloc"]
unsafe fn allocate(size: usize, _align: usize) -> *mut u8 {
    &mut MY_TINY_HEAP as *mut [u8; 16] as *mut u8
}

#[lang = "drop"]
pub trait Drop {
    fn drop(&mut self);
}

pub mod intrinsics {
    extern "rust-intrinsic" {
        pub fn abort() -> !;
        pub fn size_of<T>() -> usize;
        pub fn size_of_val<T: ?::Sized>(val: &T) -> usize;
        pub fn min_align_of<T>() -> usize;
        pub fn min_align_of_val<T: ?::Sized>(val: &T) -> usize;
        pub fn copy<T>(src: *const T, dst: *mut T, count: usize);
        pub fn transmute<T, U>(e: T) -> U;
        pub fn uninit<T>() -> T;
        pub fn ctlz_nonzero<T>(x: T) -> T;
        pub fn needs_drop<T>() -> bool;
    }
}

#[lang = "index"]
pub trait Index<Idx: ?Sized> {
    type Output: ?Sized;
    fn index(&self, index: Idx) -> &Self::Output;
}

impl<T> Index<usize> for [T; 3] {
    type Output = T;

    fn index(&self, index: usize) -> &Self::Output {
        &self[index]
    }
}

impl<T> Index<usize> for [T] {
    type Output = T;

    fn index(&self, index: usize) -> &Self::Output {
        &self[index]
    }
}