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Auto merge of #85690 - bstrie:m2_arena, r=jackh726,nagisa
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Macros 2.0-ify rustc_arena

For the purpose of battle-testing macros 2.0 I'm looking to dogfood it in rustc, one crate at a time.

(Note that there are only 12 changed lines if you ignore whitespace.)
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@bors
bors committed Aug 28, 2021
2 parents 926f069 + 71db7cc commit 5eacec9
Showing 1 changed file with 76 additions and 78 deletions.
154 changes: 76 additions & 78 deletions compiler/rustc_arena/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,8 @@
#![feature(new_uninit)]
#![feature(maybe_uninit_slice)]
#![feature(min_specialization)]
#![feature(decl_macro)]
#![feature(rustc_attrs)]
#![cfg_attr(test, feature(test))]

use rustc_data_structures::sync;
Expand Down Expand Up @@ -608,117 +610,113 @@ impl DropArena {
}
}

#[macro_export]
macro_rules! arena_for_type {
pub macro arena_for_type {
([][$ty:ty]) => {
$crate::TypedArena<$ty>
};
},
([few $(, $attrs:ident)*][$ty:ty]) => {
::std::marker::PhantomData<$ty>
};
},
([$ignore:ident $(, $attrs:ident)*]$args:tt) => {
$crate::arena_for_type!([$($attrs),*]$args)
};
},
}

#[macro_export]
macro_rules! which_arena_for_type {
pub macro which_arena_for_type {
([][$arena:expr]) => {
::std::option::Option::Some($arena)
};
},
([few$(, $attrs:ident)*][$arena:expr]) => {
::std::option::Option::None
};
},
([$ignore:ident$(, $attrs:ident)*]$args:tt) => {
$crate::which_arena_for_type!([$($attrs),*]$args)
};
},
}

#[macro_export]
macro_rules! declare_arena {
([], [$($a:tt $name:ident: $ty:ty,)*], $tcx:lifetime) => {
#[derive(Default)]
pub struct Arena<$tcx> {
pub dropless: $crate::DroplessArena,
drop: $crate::DropArena,
$($name: $crate::arena_for_type!($a[$ty]),)*
}
#[rustc_macro_transparency = "semitransparent"]
pub macro declare_arena([], [$($a:tt $name:ident: $ty:ty,)*], $tcx:lifetime) {
#[derive(Default)]
pub struct Arena<$tcx> {
pub dropless: $crate::DroplessArena,
drop: $crate::DropArena,
$($name: $crate::arena_for_type!($a[$ty]),)*
}

pub trait ArenaAllocatable<'tcx, T = Self>: Sized {
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut Self;
fn allocate_from_iter<'a>(
arena: &'a Arena<'tcx>,
iter: impl ::std::iter::IntoIterator<Item = Self>,
) -> &'a mut [Self];
pub trait ArenaAllocatable<'tcx, T = Self>: Sized {
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut Self;
fn allocate_from_iter<'a>(
arena: &'a Arena<'tcx>,
iter: impl ::std::iter::IntoIterator<Item = Self>,
) -> &'a mut [Self];
}

impl<'tcx, T: Copy> ArenaAllocatable<'tcx, ()> for T {
#[inline]
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut Self {
arena.dropless.alloc(self)
}
#[inline]
fn allocate_from_iter<'a>(
arena: &'a Arena<'tcx>,
iter: impl ::std::iter::IntoIterator<Item = Self>,
) -> &'a mut [Self] {
arena.dropless.alloc_from_iter(iter)
}

impl<'tcx, T: Copy> ArenaAllocatable<'tcx, ()> for T {
}
$(
impl<$tcx> ArenaAllocatable<$tcx, $ty> for $ty {
#[inline]
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut Self {
arena.dropless.alloc(self)
fn allocate_on<'a>(self, arena: &'a Arena<$tcx>) -> &'a mut Self {
if !::std::mem::needs_drop::<Self>() {
return arena.dropless.alloc(self);
}
match $crate::which_arena_for_type!($a[&arena.$name]) {
::std::option::Option::<&$crate::TypedArena<Self>>::Some(ty_arena) => {
ty_arena.alloc(self)
}
::std::option::Option::None => unsafe { arena.drop.alloc(self) },
}
}

#[inline]
fn allocate_from_iter<'a>(
arena: &'a Arena<'tcx>,
arena: &'a Arena<$tcx>,
iter: impl ::std::iter::IntoIterator<Item = Self>,
) -> &'a mut [Self] {
arena.dropless.alloc_from_iter(iter)
}

}
$(
impl<$tcx> ArenaAllocatable<$tcx, $ty> for $ty {
#[inline]
fn allocate_on<'a>(self, arena: &'a Arena<$tcx>) -> &'a mut Self {
if !::std::mem::needs_drop::<Self>() {
return arena.dropless.alloc(self);
}
match $crate::which_arena_for_type!($a[&arena.$name]) {
::std::option::Option::<&$crate::TypedArena<Self>>::Some(ty_arena) => {
ty_arena.alloc(self)
}
::std::option::Option::None => unsafe { arena.drop.alloc(self) },
}
if !::std::mem::needs_drop::<Self>() {
return arena.dropless.alloc_from_iter(iter);
}

#[inline]
fn allocate_from_iter<'a>(
arena: &'a Arena<$tcx>,
iter: impl ::std::iter::IntoIterator<Item = Self>,
) -> &'a mut [Self] {
if !::std::mem::needs_drop::<Self>() {
return arena.dropless.alloc_from_iter(iter);
}
match $crate::which_arena_for_type!($a[&arena.$name]) {
::std::option::Option::<&$crate::TypedArena<Self>>::Some(ty_arena) => {
ty_arena.alloc_from_iter(iter)
}
::std::option::Option::None => unsafe { arena.drop.alloc_from_iter(iter) },
match $crate::which_arena_for_type!($a[&arena.$name]) {
::std::option::Option::<&$crate::TypedArena<Self>>::Some(ty_arena) => {
ty_arena.alloc_from_iter(iter)
}
::std::option::Option::None => unsafe { arena.drop.alloc_from_iter(iter) },
}
}
)*
}
)*

impl<'tcx> Arena<'tcx> {
#[inline]
pub fn alloc<T: ArenaAllocatable<'tcx, U>, U>(&self, value: T) -> &mut T {
value.allocate_on(self)
}
impl<'tcx> Arena<'tcx> {
#[inline]
pub fn alloc<T: ArenaAllocatable<'tcx, U>, U>(&self, value: T) -> &mut T {
value.allocate_on(self)
}

#[inline]
pub fn alloc_slice<T: ::std::marker::Copy>(&self, value: &[T]) -> &mut [T] {
if value.is_empty() {
return &mut [];
}
self.dropless.alloc_slice(value)
#[inline]
pub fn alloc_slice<T: ::std::marker::Copy>(&self, value: &[T]) -> &mut [T] {
if value.is_empty() {
return &mut [];
}
self.dropless.alloc_slice(value)
}

pub fn alloc_from_iter<'a, T: ArenaAllocatable<'tcx, U>, U>(
&'a self,
iter: impl ::std::iter::IntoIterator<Item = T>,
) -> &'a mut [T] {
T::allocate_from_iter(self, iter)
}
pub fn alloc_from_iter<'a, T: ArenaAllocatable<'tcx, U>, U>(
&'a self,
iter: impl ::std::iter::IntoIterator<Item = T>,
) -> &'a mut [T] {
T::allocate_from_iter(self, iter)
}
}
}
Expand Down

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