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Auto merge of #109971 - WaffleLapkin:yeet_ownership, r=Nilstrieb

Browse Source 
Yeet `owning_ref`

Based on the discussions from https://github.com/rust-lang/rust/pull/109948

This replaces `owning_ref` with a far simpler & safer abstraction.

Fixes #109974
This commit is contained in:
bors 2023-04-08 01:08:26 +00:00
commit 0f0dc29264
13 changed files with 227 additions and 2012 deletions
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11
compiler/rustc_codegen_ssa/src/back/metadata.rs
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@ -13,8 +13,7 @@ use object::{
use snap::write::FrameEncoder;
use rustc_data_structures::memmap::Mmap;
use rustc_data_structures::owning_ref::OwningRef;
use rustc_data_structures::rustc_erase_owner;
use rustc_data_structures::owned_slice::try_slice_owned;
use rustc_data_structures::sync::MetadataRef;
use rustc_metadata::fs::METADATA_FILENAME;
use rustc_metadata::EncodedMetadata;
@ -42,10 +41,10 @@ fn load_metadata_with(
) -> Result<MetadataRef, String> {
let file =
File::open(path).map_err(|e| format!("failed to open file '{}': {}", path.display(), e))?;
let data = unsafe { Mmap::map(file) }
.map_err(|e| format!("failed to mmap file '{}': {}", path.display(), e))?;
let metadata = OwningRef::new(data).try_map(f)?;
return Ok(rustc_erase_owner!(metadata.map_owner_box()));
unsafe { Mmap::map(file) }
.map_err(|e| format!("failed to mmap file '{}': {}", path.display(), e))
.and_then(|mmap| try_slice_owned(mmap, |mmap| f(mmap)))
}
impl MetadataLoader for DefaultMetadataLoader {

6
compiler/rustc_data_structures/src/lib.rs
View File

@ -1,5 +1,5 @@
//! Various data structures used by the Rust compiler. The intention
//! is that code in here should be not be *specific* to rustc, so that
//! is that code in here should not be *specific* to rustc, so that
//! it can be easily unit tested and so forth.
//!
//! # Note
@ -27,6 +27,8 @@
#![feature(thread_id_value)]
#![feature(vec_into_raw_parts)]
#![feature(get_mut_unchecked)]
#![feature(lint_reasons)]
#![feature(unwrap_infallible)]
#![allow(rustc::default_hash_types)]
#![allow(rustc::potential_query_instability)]
#![deny(rustc::untranslatable_diagnostic)]
@ -59,7 +61,6 @@ pub mod intern;
pub mod jobserver;
pub mod macros;
pub mod obligation_forest;
pub mod owning_ref;
pub mod sip128;
pub mod small_c_str;
pub mod small_str;
@ -82,6 +83,7 @@ pub mod vec_linked_list;
pub mod work_queue;
pub use atomic_ref::AtomicRef;
pub mod frozen;
pub mod owned_slice;
pub mod sso;
pub mod steal;
pub mod tagged_ptr;

10
compiler/rustc_data_structures/src/memmap.rs
View File

@ -2,9 +2,7 @@ use std::fs::File;
use std::io;
use std::ops::{Deref, DerefMut};
use crate::owning_ref::StableAddress;
/// A trivial wrapper for [`memmap2::Mmap`] that implements [`StableAddress`].
/// A trivial wrapper for [`memmap2::Mmap`] (or `Vec<u8>` on WASM).
#[cfg(not(target_arch = "wasm32"))]
pub struct Mmap(memmap2::Mmap);
@ -46,12 +44,6 @@ impl AsRef<[u8]> for Mmap {
}
}
// SAFETY: On architectures other than WASM, mmap is used as backing storage. The address of this
// memory map is stable. On WASM, `Vec<u8>` is used as backing storage. The `Mmap` type doesn't
// export any function that can cause the `Vec` to be re-allocated. As such the address of the
// bytes inside this `Vec` is stable.
unsafe impl StableAddress for Mmap {}
#[cfg(not(target_arch = "wasm32"))]
pub struct MmapMut(memmap2::MmapMut);

118
compiler/rustc_data_structures/src/owned_slice.rs Normal file
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@ -0,0 +1,118 @@
use std::{borrow::Borrow, ops::Deref};
// Use our fake Send/Sync traits when on not parallel compiler,
// so that `OwnedSlice` only implements/requires Send/Sync
// for parallel compiler builds.
use crate::sync::{Send, Sync};
/// An owned slice.
///
/// This is similar to `Box<[u8]>` but allows slicing and using anything as the
/// backing buffer.
///
/// See [`slice_owned`] for `OwnedSlice` construction and examples.
///
/// ---------------------------------------------------------------------------
///
/// This is essentially a replacement for `owning_ref` which is a lot simpler
/// and even sound! 🌸
pub struct OwnedSlice {
/// This is conceptually a `&'self.owner [u8]`.
bytes: *const [u8],
// +---------------------------------------+
// | We expect `dead_code` lint here, |
// | because we don't want to accidentally |
// | touch the owner — otherwise the owner |
// | could invalidate out `bytes` pointer |
// | |
// | so be quiet |
// +----+ +-------------------------------+
// \/
// ⊂(´･◡･⊂ )∘˚˳° (I am the phantom remnant of #97770)
#[expect(dead_code)]
owner: Box<dyn Send + Sync>,
}
/// Makes an [`OwnedSlice`] out of an `owner` and a `slicer` function.
///
/// ## Examples
///
/// ```rust
/// # use rustc_data_structures::owned_slice::{OwnedSlice, slice_owned};
/// let vec = vec![1, 2, 3, 4];
///
/// // Identical to slicing via `&v[1..3]` but produces an owned slice
/// let slice: OwnedSlice = slice_owned(vec, |v| &v[1..3]);
/// assert_eq!(&*slice, [2, 3]);
/// ```
///
/// ```rust
/// # use rustc_data_structures::owned_slice::{OwnedSlice, slice_owned};
/// # use std::ops::Deref;
/// let vec = vec![1, 2, 3, 4];
///
/// // Identical to slicing via `&v[..]` but produces an owned slice
/// let slice: OwnedSlice = slice_owned(vec, Deref::deref);
/// assert_eq!(&*slice, [1, 2, 3, 4]);
/// ```
pub fn slice_owned<O, F>(owner: O, slicer: F) -> OwnedSlice
where
O: Send + Sync + 'static,
F: FnOnce(&O) -> &[u8],
{
try_slice_owned(owner, |x| Ok::<_, !>(slicer(x))).into_ok()
}
/// Makes an [`OwnedSlice`] out of an `owner` and a `slicer` function that can fail.
///
/// See [`slice_owned`] for the infallible version.
pub fn try_slice_owned<O, F, E>(owner: O, slicer: F) -> Result<OwnedSlice, E>
where
O: Send + Sync + 'static,
F: FnOnce(&O) -> Result<&[u8], E>,
{
// We box the owner of the bytes, so it doesn't move.
//
// Since the owner does not move and we don't access it in any way
// before drop, there is nothing that can invalidate the bytes pointer.
//
// Thus, "extending" the lifetime of the reference returned from `F` is fine.
// We pretend that we pass it a reference that lives as long as the returned slice.
//
// N.B. the HRTB on the `slicer` is important — without it the caller could provide
// a short lived slice, unrelated to the owner.
let owner = Box::new(owner);
let bytes = slicer(&*owner)?;
Ok(OwnedSlice { bytes, owner })
}
impl Deref for OwnedSlice {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
// Safety:
// `self.bytes` is valid per the construction in `slice_owned`
// (which is the only constructor)
unsafe { &*self.bytes }
}
}
impl Borrow<[u8]> for OwnedSlice {
#[inline]
fn borrow(&self) -> &[u8] {
self
}
}
// Safety: `OwnedSlice` is conceptually `(&'self.1 [u8], Box<dyn Send + Sync>)`, which is `Send`
unsafe impl Send for OwnedSlice {}
// Safety: `OwnedSlice` is conceptually `(&'self.1 [u8], Box<dyn Send + Sync>)`, which is `Sync`
unsafe impl Sync for OwnedSlice {}
#[cfg(test)]
mod tests;

74
compiler/rustc_data_structures/src/owned_slice/tests.rs Normal file
View File

@ -0,0 +1,74 @@
use std::{
ops::Deref,
sync::{
atomic::{self, AtomicBool},
Arc,
},
};
use crate::{
owned_slice::{slice_owned, try_slice_owned, OwnedSlice},
OnDrop,
};
#[test]
fn smoke() {
let slice = slice_owned(vec![1, 2, 3, 4, 5, 6], Vec::as_slice);
assert_eq!(&*slice, [1, 2, 3, 4, 5, 6]);
}
#[test]
fn static_storage() {
let slice = slice_owned(Box::new(String::from("what")), |_| b"bytes boo");
assert_eq!(&*slice, b"bytes boo");
}
#[test]
fn slice_the_slice() {
let slice = slice_owned(vec![1, 2, 3, 4, 5, 6], Vec::as_slice);
let slice = slice_owned(slice, |s| &s[1..][..4]);
let slice = slice_owned(slice, |s| s);
let slice = slice_owned(slice, |s| &s[1..]);
assert_eq!(&*slice, &[1, 2, 3, 4, 5, 6][1..][..4][1..]);
}
#[test]
fn try_and_fail() {
let res = try_slice_owned(vec![0], |v| v.get(12..).ok_or(()));
assert!(res.is_err());
}
#[test]
fn boxed() {
// It's important that we don't cause UB because of `Box`'es uniqueness
let boxed: Box<[u8]> = vec![1, 1, 2, 3, 5, 8, 13, 21].into_boxed_slice();
let slice = slice_owned(boxed, Deref::deref);
assert_eq!(&*slice, [1, 1, 2, 3, 5, 8, 13, 21]);
}
#[test]
fn drop_drops() {
let flag = Arc::new(AtomicBool::new(false));
let flag_prime = Arc::clone(&flag);
let d = OnDrop(move || flag_prime.store(true, atomic::Ordering::Relaxed));
let slice = slice_owned(d, |_| &[]);
assert_eq!(flag.load(atomic::Ordering::Relaxed), false);
drop(slice);
assert_eq!(flag.load(atomic::Ordering::Relaxed), true);
}
#[test]
fn send_sync() {
crate::sync::assert_send::<OwnedSlice>();
crate::sync::assert_sync::<OwnedSlice>();
}

21
compiler/rustc_data_structures/src/owning_ref/LICENSE
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@ -1,21 +0,0 @@
The MIT License (MIT)
Copyright (c) 2015 Marvin Löbel
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

1211
compiler/rustc_data_structures/src/owning_ref/mod.rs
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File diff suppressed because it is too large Load Diff

711
compiler/rustc_data_structures/src/owning_ref/tests.rs
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@ -1,711 +0,0 @@
// FIXME: owning_ref is not sound under stacked borrows. Preferably, get rid of it.
#[cfg(not(miri))]
mod owning_ref {
use super::super::OwningRef;
use super::super::{BoxRef, Erased, ErasedBoxRef, RcRef};
use std::cmp::Ordering;
use std::collections::hash_map::DefaultHasher;
use std::collections::HashMap;
use std::hash::{Hash, Hasher};
use std::rc::Rc;
#[derive(Debug, PartialEq)]
struct Example(u32, String, [u8; 3]);
fn example() -> Example {
Example(42, "hello world".to_string(), [1, 2, 3])
}
#[test]
fn new_deref() {
let or: OwningRef<Box<()>, ()> = OwningRef::new(Box::new(()));
assert_eq!(&*or, &());
}
#[test]
fn into() {
let or: OwningRef<Box<()>, ()> = Box::new(()).into();
assert_eq!(&*or, &());
}
#[test]
fn map_offset_ref() {
let or: BoxRef<Example> = Box::new(example()).into();
let or: BoxRef<_, u32> = or.map(|x| &x.0);
assert_eq!(&*or, &42);
let or: BoxRef<Example> = Box::new(example()).into();
let or: BoxRef<_, u8> = or.map(|x| &x.2[1]);
assert_eq!(&*or, &2);
}
#[test]
fn map_heap_ref() {
let or: BoxRef<Example> = Box::new(example()).into();
let or: BoxRef<_, str> = or.map(|x| &x.1[..5]);
assert_eq!(&*or, "hello");
}
#[test]
fn map_static_ref() {
let or: BoxRef<()> = Box::new(()).into();
let or: BoxRef<_, str> = or.map(|_| "hello");
assert_eq!(&*or, "hello");
}
#[test]
fn map_chained() {
let or: BoxRef<String> = Box::new(example().1).into();
let or: BoxRef<_, str> = or.map(|x| &x[1..5]);
let or: BoxRef<_, str> = or.map(|x| &x[..2]);
assert_eq!(&*or, "el");
}
#[test]
fn map_chained_inference() {
let or = BoxRef::new(Box::new(example().1)).map(|x| &x[..5]).map(|x| &x[1..3]);
assert_eq!(&*or, "el");
}
#[test]
fn owner() {
let or: BoxRef<String> = Box::new(example().1).into();
let or = or.map(|x| &x[..5]);
assert_eq!(&*or, "hello");
assert_eq!(&**or.owner(), "hello world");
}
#[test]
fn into_inner() {
let or: BoxRef<String> = Box::new(example().1).into();
let or = or.map(|x| &x[..5]);
assert_eq!(&*or, "hello");
let s = *or.into_inner();
assert_eq!(&s, "hello world");
}
#[test]
fn fmt_debug() {
let or: BoxRef<String> = Box::new(example().1).into();
let or = or.map(|x| &x[..5]);
let s = format!("{:?}", or);
assert_eq!(&s, "OwningRef { owner: \"hello world\", reference: \"hello\" }");
}
#[test]
fn erased_owner() {
let o1: BoxRef<Example, str> = BoxRef::new(Box::new(example())).map(|x| &x.1[..]);
let o2: BoxRef<String, str> = BoxRef::new(Box::new(example().1)).map(|x| &x[..]);
let os: Vec<ErasedBoxRef<str>> = vec![o1.erase_owner(), o2.erase_owner()];
assert!(os.iter().all(|e| &e[..] == "hello world"));
}
#[test]
fn raii_locks() {
use super::super::{MutexGuardRef, RwLockReadGuardRef, RwLockWriteGuardRef};
use super::super::{RefMutRef, RefRef};
use std::cell::RefCell;
use std::sync::{Mutex, RwLock};
{
let a = RefCell::new(1);
let a = {
let a = RefRef::new(a.borrow());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
{
let a = RefCell::new(1);
let a = {
let a = RefMutRef::new(a.borrow_mut());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
{
let a = Mutex::new(1);
let a = {
let a = MutexGuardRef::new(a.lock().unwrap());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
{
let a = RwLock::new(1);
let a = {
let a = RwLockReadGuardRef::new(a.read().unwrap());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
{
let a = RwLock::new(1);
let a = {
let a = RwLockWriteGuardRef::new(a.write().unwrap());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
}
#[test]
fn eq() {
let or1: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice());
let or2: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice());
assert_eq!(or1.eq(&or2), true);
}
#[test]
fn cmp() {
let or1: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice());
let or2: BoxRef<[u8]> = BoxRef::new(vec![4, 5, 6].into_boxed_slice());
assert_eq!(or1.cmp(&or2), Ordering::Less);
}
#[test]
fn partial_cmp() {
let or1: BoxRef<[u8]> = BoxRef::new(vec![4, 5, 6].into_boxed_slice());
let or2: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice());
assert_eq!(or1.partial_cmp(&or2), Some(Ordering::Greater));
}
#[test]
fn hash() {
let mut h1 = DefaultHasher::new();
let mut h2 = DefaultHasher::new();
let or1: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice());
let or2: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice());
or1.hash(&mut h1);
or2.hash(&mut h2);
assert_eq!(h1.finish(), h2.finish());
}
#[test]
fn borrow() {
let mut hash = HashMap::new();
let key = RcRef::<String>::new(Rc::new("foo-bar".to_string())).map(|s| &s[..]);
hash.insert(key.clone().map(|s| &s[..3]), 42);
hash.insert(key.clone().map(|s| &s[4..]), 23);
assert_eq!(hash.get("foo"), Some(&42));
assert_eq!(hash.get("bar"), Some(&23));
}
#[test]
fn total_erase() {
let a: OwningRef<Vec<u8>, [u8]> = OwningRef::new(vec![]).map(|x| &x[..]);
let b: OwningRef<Box<[u8]>, [u8]> =
OwningRef::new(vec![].into_boxed_slice()).map(|x| &x[..]);
let c: OwningRef<Rc<Vec<u8>>, [u8]> = unsafe { a.map_owner(Rc::new) };
let d: OwningRef<Rc<Box<[u8]>>, [u8]> = unsafe { b.map_owner(Rc::new) };
let e: OwningRef<Rc<dyn Erased>, [u8]> = c.erase_owner();
let f: OwningRef<Rc<dyn Erased>, [u8]> = d.erase_owner();
let _g = e.clone();
let _h = f.clone();
}
#[test]
fn total_erase_box() {
let a: OwningRef<Vec<u8>, [u8]> = OwningRef::new(vec![]).map(|x| &x[..]);
let b: OwningRef<Box<[u8]>, [u8]> =
OwningRef::new(vec![].into_boxed_slice()).map(|x| &x[..]);
let c: OwningRef<Box<Vec<u8>>, [u8]> = a.map_owner_box();
let d: OwningRef<Box<Box<[u8]>>, [u8]> = b.map_owner_box();
let _e: OwningRef<Box<dyn Erased>, [u8]> = c.erase_owner();
let _f: OwningRef<Box<dyn Erased>, [u8]> = d.erase_owner();
}
#[test]
fn try_map1() {
use std::any::Any;
let x = Box::new(123_i32);
let y: Box<dyn Any> = x;
assert!(OwningRef::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).is_ok());
}
#[test]
fn try_map2() {
use std::any::Any;
let x = Box::new(123_i32);
let y: Box<dyn Any> = x;
assert!(!OwningRef::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).is_err());
}
}
mod owning_handle {
use super::super::OwningHandle;
use super::super::RcRef;
use std::cell::RefCell;
use std::rc::Rc;
use std::sync::Arc;
use std::sync::RwLock;
#[test]
fn owning_handle() {
use std::cell::RefCell;
let cell = Rc::new(RefCell::new(2));
let cell_ref = RcRef::new(cell);
let mut handle =
OwningHandle::new_with_fn(cell_ref, |x| unsafe { x.as_ref() }.unwrap().borrow_mut());
assert_eq!(*handle, 2);
*handle = 3;
assert_eq!(*handle, 3);
}
#[test]
fn try_owning_handle_ok() {
use std::cell::RefCell;
let cell = Rc::new(RefCell::new(2));
let cell_ref = RcRef::new(cell);
let mut handle = OwningHandle::try_new::<_, ()>(cell_ref, |x| {
Ok(unsafe { x.as_ref() }.unwrap().borrow_mut())
})
.unwrap();
assert_eq!(*handle, 2);
*handle = 3;
assert_eq!(*handle, 3);
}
#[test]
fn try_owning_handle_err() {
use std::cell::RefCell;
let cell = Rc::new(RefCell::new(2));
let cell_ref = RcRef::new(cell);
let handle = OwningHandle::try_new::<_, ()>(cell_ref, |x| {
if false {
return Ok(unsafe { x.as_ref() }.unwrap().borrow_mut());
}
Err(())
});
assert!(handle.is_err());
}
#[test]
fn nested() {
use std::cell::RefCell;
use std::sync::{Arc, RwLock};
let result = {
let complex = Rc::new(RefCell::new(Arc::new(RwLock::new("someString"))));
let curr = RcRef::new(complex);
let curr =
OwningHandle::new_with_fn(curr, |x| unsafe { x.as_ref() }.unwrap().borrow_mut());
let mut curr = OwningHandle::new_with_fn(curr, |x| {
unsafe { x.as_ref() }.unwrap().try_write().unwrap()
});
assert_eq!(*curr, "someString");
*curr = "someOtherString";
curr
};
assert_eq!(*result, "someOtherString");
}
#[test]
fn owning_handle_safe() {
use std::cell::RefCell;
let cell = Rc::new(RefCell::new(2));
let cell_ref = RcRef::new(cell);
let handle = OwningHandle::new(cell_ref);
assert_eq!(*handle, 2);
}
#[test]
fn owning_handle_mut_safe() {
use std::cell::RefCell;
let cell = Rc::new(RefCell::new(2));
let cell_ref = RcRef::new(cell);
let mut handle = OwningHandle::new_mut(cell_ref);
assert_eq!(*handle, 2);
*handle = 3;
assert_eq!(*handle, 3);
}
#[test]
fn owning_handle_safe_2() {
let result = {
let complex = Rc::new(RefCell::new(Arc::new(RwLock::new("someString"))));
let curr = RcRef::new(complex);
let curr =
OwningHandle::new_with_fn(curr, |x| unsafe { x.as_ref() }.unwrap().borrow_mut());
let mut curr = OwningHandle::new_with_fn(curr, |x| {
unsafe { x.as_ref() }.unwrap().try_write().unwrap()
});
assert_eq!(*curr, "someString");
*curr = "someOtherString";
curr
};
assert_eq!(*result, "someOtherString");
}
}
// FIXME: owning_ref is not sound under stacked borrows. Preferably, get rid of it.
#[cfg(not(miri))]
mod owning_ref_mut {
use super::super::BoxRef;
use super::super::{BoxRefMut, Erased, ErasedBoxRefMut, OwningRefMut};
use std::cmp::Ordering;
use std::collections::hash_map::DefaultHasher;
use std::collections::HashMap;
use std::hash::{Hash, Hasher};
#[derive(Debug, PartialEq)]
struct Example(u32, String, [u8; 3]);
fn example() -> Example {
Example(42, "hello world".to_string(), [1, 2, 3])
}
#[test]
fn new_deref() {
let or: OwningRefMut<Box<()>, ()> = OwningRefMut::new(Box::new(()));
assert_eq!(&*or, &());
}
#[test]
fn new_deref_mut() {
let mut or: OwningRefMut<Box<()>, ()> = OwningRefMut::new(Box::new(()));
assert_eq!(&mut *or, &mut ());
}
#[test]
fn mutate() {
let mut or: OwningRefMut<Box<usize>, usize> = OwningRefMut::new(Box::new(0));
assert_eq!(&*or, &0);
*or = 1;
assert_eq!(&*or, &1);
}
#[test]
fn into() {
let or: OwningRefMut<Box<()>, ()> = Box::new(()).into();
assert_eq!(&*or, &());
}
#[test]
fn map_offset_ref() {
let or: BoxRefMut<Example> = Box::new(example()).into();
let or: BoxRef<_, u32> = or.map(|x| &mut x.0);
assert_eq!(&*or, &42);
let or: BoxRefMut<Example> = Box::new(example()).into();
let or: BoxRef<_, u8> = or.map(|x| &mut x.2[1]);
assert_eq!(&*or, &2);
}
#[test]
fn map_heap_ref() {
let or: BoxRefMut<Example> = Box::new(example()).into();
let or: BoxRef<_, str> = or.map(|x| &mut x.1[..5]);
assert_eq!(&*or, "hello");
}
#[test]
fn map_static_ref() {
let or: BoxRefMut<()> = Box::new(()).into();
let or: BoxRef<_, str> = or.map(|_| "hello");
assert_eq!(&*or, "hello");
}
#[test]
fn map_mut_offset_ref() {
let or: BoxRefMut<Example> = Box::new(example()).into();
let or: BoxRefMut<_, u32> = or.map_mut(|x| &mut x.0);
assert_eq!(&*or, &42);
let or: BoxRefMut<Example> = Box::new(example()).into();
let or: BoxRefMut<_, u8> = or.map_mut(|x| &mut x.2[1]);
assert_eq!(&*or, &2);
}
#[test]
fn map_mut_heap_ref() {
let or: BoxRefMut<Example> = Box::new(example()).into();
let or: BoxRefMut<_, str> = or.map_mut(|x| &mut x.1[..5]);
assert_eq!(&*or, "hello");
}
#[test]
fn map_mut_static_ref() {
static mut MUT_S: [u8; 5] = *b"hello";
let mut_s: &'static mut [u8] = unsafe { &mut MUT_S };
let or: BoxRefMut<()> = Box::new(()).into();
let or: BoxRefMut<_, [u8]> = or.map_mut(move |_| mut_s);
assert_eq!(&*or, b"hello");
}
#[test]
fn map_mut_chained() {
let or: BoxRefMut<String> = Box::new(example().1).into();
let or: BoxRefMut<_, str> = or.map_mut(|x| &mut x[1..5]);
let or: BoxRefMut<_, str> = or.map_mut(|x| &mut x[..2]);
assert_eq!(&*or, "el");
}
#[test]
fn map_chained_inference() {
let or = BoxRefMut::new(Box::new(example().1))
.map_mut(|x| &mut x[..5])
.map_mut(|x| &mut x[1..3]);
assert_eq!(&*or, "el");
}
#[test]
fn try_map_mut() {
let or: BoxRefMut<String> = Box::new(example().1).into();
let or: Result<BoxRefMut<_, str>, ()> = or.try_map_mut(|x| Ok(&mut x[1..5]));
assert_eq!(&*or.unwrap(), "ello");
let or: BoxRefMut<String> = Box::new(example().1).into();
let or: Result<BoxRefMut<_, str>, ()> = or.try_map_mut(|_| Err(()));
assert!(or.is_err());
}
#[test]
fn owner() {
let or: BoxRefMut<String> = Box::new(example().1).into();
let or = or.map_mut(|x| &mut x[..5]);
assert_eq!(&*or, "hello");
assert_eq!(&**or.owner(), "hello world");
}
#[test]
fn into_inner() {
let or: BoxRefMut<String> = Box::new(example().1).into();
let or = or.map_mut(|x| &mut x[..5]);
assert_eq!(&*or, "hello");
let s = *or.into_inner();
assert_eq!(&s, "hello world");
}
#[test]
fn fmt_debug() {
let or: BoxRefMut<String> = Box::new(example().1).into();
let or = or.map_mut(|x| &mut x[..5]);
let s = format!("{:?}", or);
assert_eq!(&s, "OwningRefMut { owner: \"hello world\", reference: \"hello\" }");
}
#[test]
fn erased_owner() {
let o1: BoxRefMut<Example, str> =
BoxRefMut::new(Box::new(example())).map_mut(|x| &mut x.1[..]);
let o2: BoxRefMut<String, str> =
BoxRefMut::new(Box::new(example().1)).map_mut(|x| &mut x[..]);
let os: Vec<ErasedBoxRefMut<str>> = vec![o1.erase_owner(), o2.erase_owner()];
assert!(os.iter().all(|e| &e[..] == "hello world"));
}
#[test]
fn raii_locks() {
use super::super::RefMutRefMut;
use super::super::{MutexGuardRefMut, RwLockWriteGuardRefMut};
use std::cell::RefCell;
use std::sync::{Mutex, RwLock};
{
let a = RefCell::new(1);
let a = {
let a = RefMutRefMut::new(a.borrow_mut());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
{
let a = Mutex::new(1);
let a = {
let a = MutexGuardRefMut::new(a.lock().unwrap());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
{
let a = RwLock::new(1);
let a = {
let a = RwLockWriteGuardRefMut::new(a.write().unwrap());
assert_eq!(*a, 1);
a
};
assert_eq!(*a, 1);
drop(a);
}
}
#[test]
fn eq() {
let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice());
let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice());
assert_eq!(or1.eq(&or2), true);
}
#[test]
fn cmp() {
let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice());
let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![4, 5, 6].into_boxed_slice());
assert_eq!(or1.cmp(&or2), Ordering::Less);
}
#[test]
fn partial_cmp() {
let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![4, 5, 6].into_boxed_slice());
let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice());
assert_eq!(or1.partial_cmp(&or2), Some(Ordering::Greater));
}
#[test]
fn hash() {
let mut h1 = DefaultHasher::new();
let mut h2 = DefaultHasher::new();
let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice());
let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice());
or1.hash(&mut h1);
or2.hash(&mut h2);
assert_eq!(h1.finish(), h2.finish());
}
#[test]
fn borrow() {
let mut hash = HashMap::new();
let key1 = BoxRefMut::<String>::new(Box::new("foo".to_string())).map(|s| &s[..]);
let key2 = BoxRefMut::<String>::new(Box::new("bar".to_string())).map(|s| &s[..]);
hash.insert(key1, 42);
hash.insert(key2, 23);
assert_eq!(hash.get("foo"), Some(&42));
assert_eq!(hash.get("bar"), Some(&23));
}
#[test]
fn total_erase() {
let a: OwningRefMut<Vec<u8>, [u8]> = OwningRefMut::new(vec![]).map_mut(|x| &mut x[..]);
let b: OwningRefMut<Box<[u8]>, [u8]> =
OwningRefMut::new(vec![].into_boxed_slice()).map_mut(|x| &mut x[..]);
let c: OwningRefMut<Box<Vec<u8>>, [u8]> = unsafe { a.map_owner(Box::new) };
let d: OwningRefMut<Box<Box<[u8]>>, [u8]> = unsafe { b.map_owner(Box::new) };
let _e: OwningRefMut<Box<dyn Erased>, [u8]> = c.erase_owner();
let _f: OwningRefMut<Box<dyn Erased>, [u8]> = d.erase_owner();
}
#[test]
fn total_erase_box() {
let a: OwningRefMut<Vec<u8>, [u8]> = OwningRefMut::new(vec![]).map_mut(|x| &mut x[..]);
let b: OwningRefMut<Box<[u8]>, [u8]> =
OwningRefMut::new(vec![].into_boxed_slice()).map_mut(|x| &mut x[..]);
let c: OwningRefMut<Box<Vec<u8>>, [u8]> = a.map_owner_box();
let d: OwningRefMut<Box<Box<[u8]>>, [u8]> = b.map_owner_box();
let _e: OwningRefMut<Box<dyn Erased>, [u8]> = c.erase_owner();
let _f: OwningRefMut<Box<dyn Erased>, [u8]> = d.erase_owner();
}
#[test]
fn try_map1() {
use std::any::Any;
let x = Box::new(123_i32);
let y: Box<dyn Any> = x;
assert!(OwningRefMut::new(y).try_map_mut(|x| x.downcast_mut::<i32>().ok_or(())).is_ok());
}
#[test]
fn try_map2() {
use std::any::Any;
let x = Box::new(123_i32);
let y: Box<dyn Any> = x;
assert!(!OwningRefMut::new(y).try_map_mut(|x| x.downcast_mut::<i32>().ok_or(())).is_err());
}
#[test]
fn try_map3() {
use std::any::Any;
let x = Box::new(123_i32);
let y: Box<dyn Any> = x;
assert!(OwningRefMut::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).is_ok());
}
#[test]
fn try_map4() {
use std::any::Any;
let x = Box::new(123_i32);
let y: Box<dyn Any> = x;
assert!(!OwningRefMut::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).is_err());
}
#[test]
fn into_owning_ref() {
use super::super::BoxRef;
let or: BoxRefMut<()> = Box::new(()).into();
let or: BoxRef<()> = or.into();
assert_eq!(&*or, &());
}
struct Foo {
u: u32,
}
struct Bar {
f: Foo,
}
#[test]
fn ref_mut() {
use std::cell::RefCell;
let a = RefCell::new(Bar { f: Foo { u: 42 } });
let mut b = OwningRefMut::new(a.borrow_mut());
assert_eq!(b.f.u, 42);
b.f.u = 43;
let mut c = b.map_mut(|x| &mut x.f);
assert_eq!(c.u, 43);
c.u = 44;
let mut d = c.map_mut(|x| &mut x.u);
assert_eq!(*d, 44);
*d = 45;
assert_eq!(*d, 45);
}
}

33
compiler/rustc_data_structures/src/sync.rs
View File

@ -7,9 +7,6 @@
//! while the serial versions degenerate straightforwardly to serial execution.
//! The operations include `join`, `parallel`, `par_iter`, and `par_for_each`.
//!
//! `rustc_erase_owner!` erases an `OwningRef` owner into `Erased` for the
//! serial version and `Erased + Send + Sync` for the parallel version.
//!
//! Types
//! -----
//! The parallel versions of types provide various kinds of synchronization,
@ -42,7 +39,7 @@
//!
//! [^2] `MTLockRef` is a typedef.
use crate::owning_ref::{Erased, OwningRef};
use crate::owned_slice::OwnedSlice;
use std::collections::HashMap;
use std::hash::{BuildHasher, Hash};
use std::ops::{Deref, DerefMut};
@ -57,18 +54,11 @@ mod vec;
cfg_if! {
if #[cfg(not(parallel_compiler))] {
pub auto trait Send {}
pub auto trait Sync {}
pub unsafe auto trait Send {}
pub unsafe auto trait Sync {}
impl<T> Send for T {}
impl<T> Sync for T {}
#[macro_export]
macro_rules! rustc_erase_owner {
($v:expr) => {
$v.erase_owner()
}
}
unsafe impl<T> Send for T {}
unsafe impl<T> Sync for T {}
use std::ops::Add;
@ -197,7 +187,7 @@ cfg_if! {
}
}
pub type MetadataRef = OwningRef<Box<dyn Erased>, [u8]>;
pub type MetadataRef = OwnedSlice;
pub use std::rc::Rc as Lrc;
pub use std::rc::Weak as Weak;
@ -380,20 +370,11 @@ cfg_if! {
});
}
pub type MetadataRef = OwningRef<Box<dyn Erased + Send + Sync>, [u8]>;
pub type MetadataRef = OwnedSlice;
/// This makes locks panic if they are already held.
/// It is only useful when you are running in a single thread
const ERROR_CHECKING: bool = false;
#[macro_export]
macro_rules! rustc_erase_owner {
($v:expr) => {{
let v = $v;
::rustc_data_structures::sync::assert_send_val(&v);
v.erase_send_sync_owner()
}}
}
}
}

2
compiler/rustc_metadata/src/lib.rs
View File

@ -22,8 +22,6 @@ extern crate proc_macro;
extern crate rustc_macros;
#[macro_use]
extern crate rustc_middle;
#[macro_use]
extern crate rustc_data_structures;
#[macro_use]
extern crate tracing;

22
compiler/rustc_metadata/src/locator.rs
View File

@ -218,7 +218,7 @@ use crate::rmeta::{rustc_version, MetadataBlob, METADATA_HEADER};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::memmap::Mmap;
use rustc_data_structures::owning_ref::OwningRef;
use rustc_data_structures::owned_slice::slice_owned;
use rustc_data_structures::svh::Svh;
use rustc_data_structures::sync::MetadataRef;
use rustc_errors::{DiagnosticArgValue, FatalError, IntoDiagnosticArg};
@ -236,6 +236,7 @@ use rustc_target::spec::{Target, TargetTriple};
use snap::read::FrameDecoder;
use std::borrow::Cow;
use std::io::{Read, Result as IoResult, Write};
use std::ops::Deref;
use std::path::{Path, PathBuf};
use std::{cmp, fmt};
@ -814,15 +815,14 @@ fn get_metadata_section<'p>(
// Assume the decompressed data will be at least the size of the compressed data, so we
// don't have to grow the buffer as much.
let mut inflated = Vec::with_capacity(compressed_bytes.len());
match FrameDecoder::new(compressed_bytes).read_to_end(&mut inflated) {
Ok(_) => rustc_erase_owner!(OwningRef::new(inflated).map_owner_box()),
Err(_) => {
return Err(MetadataError::LoadFailure(format!(
"failed to decompress metadata: {}",
filename.display()
)));
}
}
FrameDecoder::new(compressed_bytes).read_to_end(&mut inflated).map_err(|_| {
MetadataError::LoadFailure(format!(
"failed to decompress metadata: {}",
filename.display()
))
})?;
slice_owned(inflated, Deref::deref)
}
CrateFlavor::Rmeta => {
// mmap the file, because only a small fraction of it is read.
@ -840,7 +840,7 @@ fn get_metadata_section<'p>(
))
})?;
rustc_erase_owner!(OwningRef::new(mmap).map_owner_box())
slice_owned(mmap, Deref::deref)
}
};
let blob = MetadataBlob::new(raw_bytes);

6
compiler/rustc_metadata/src/rmeta/decoder.rs
View File

@ -51,12 +51,6 @@ mod cstore_impl;
#[derive(Clone)]
pub(crate) struct MetadataBlob(Lrc<MetadataRef>);
// This is needed so we can create an OwningRef into the blob.
// The data behind a `MetadataBlob` has a stable address because it is
// contained within an Rc/Arc.
unsafe impl rustc_data_structures::owning_ref::StableAddress for MetadataBlob {}
// This is needed so we can create an OwningRef into the blob.
impl std::ops::Deref for MetadataBlob {
type Target = [u8];

14
compiler/rustc_metadata/src/rmeta/def_path_hash_map.rs
View File

@ -1,14 +1,14 @@
use crate::rmeta::DecodeContext;
use crate::rmeta::EncodeContext;
use crate::rmeta::MetadataBlob;
use rustc_data_structures::owning_ref::OwningRef;
use rustc_data_structures::owned_slice::slice_owned;
use rustc_data_structures::owned_slice::OwnedSlice;
use rustc_hir::def_path_hash_map::{Config as HashMapConfig, DefPathHashMap};
use rustc_middle::parameterized_over_tcx;
use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
use rustc_span::def_id::{DefIndex, DefPathHash};
pub(crate) enum DefPathHashMapRef<'tcx> {
OwnedFromMetadata(odht::HashTable<HashMapConfig, OwningRef<MetadataBlob, [u8]>>),
OwnedFromMetadata(odht::HashTable<HashMapConfig, OwnedSlice>),
BorrowedFromTcx(&'tcx DefPathHashMap),
}
@ -50,11 +50,11 @@ impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefPathHashMapRef<'static>
let len = d.read_usize();
let pos = d.position();
let o = OwningRef::new(d.blob().clone()).map(|x| &x[pos..pos + len]);
let o = slice_owned(d.blob().clone(), |blob| &blob[pos..pos + len]);
// Although we already have the data we need via the OwningRef, we still need
// to advance the DecodeContext's position so it's in a valid state after
// the method. We use read_raw_bytes() for that.
// Although we already have the data we need via the `OwnedSlice`, we still need
// to advance the `DecodeContext`'s position so it's in a valid state after
// the method. We use `read_raw_bytes()` for that.
let _ = d.read_raw_bytes(len);
let inner = odht::HashTable::from_raw_bytes(o).unwrap_or_else(|e| {