Commit graph

18 commits

Author SHA1 Message Date
Chris Ohk
3281aea5c2 Fix minor typos in code and docs (#7378)
# Objective

I found several words in code and docs are incorrect. This should be fixed.

## Solution

- Fix several minor typos

Co-authored-by: Chris Ohk <utilforever@gmail.com>
2023-01-27 12:12:53 +00:00
JoJoJet
629cfab135 Improve safety for CommandQueue internals (#7039)
# Objective

- Safety comments for the `CommandQueue` type are quite sparse and very imprecise. Sometimes, they are right for the wrong reasons or use circular reasoning.

## Solution

- Document previously-implicit safety invariants.
- Rewrite safety comments to actually reflect the specific invariants of each operation.
- Use `OwningPtr` instead of raw pointers, to encode an invariant in the type system instead of via comments.
- Use typed pointer methods when possible to increase reliability.

---

## Changelog

+ Added the function `OwningPtr::read_unaligned`.
2023-01-19 03:04:39 +00:00
JoJoJet
4b326fb4ca Improve safety for BlobVec::replace_unchecked (#7181)
# Objective

- The function `BlobVec::replace_unchecked` has informal use of safety comments.
- This function does strange things with `OwningPtr` in order to get around the borrow checker.

## Solution

- Put safety comments in front of each unsafe operation. Describe the specific invariants of each operation and how they apply here.
- Added a guard type `OnDrop`, which is used to simplify ownership transfer in case of a panic.

---

## Changelog

+ Added the guard type `bevy_utils::OnDrop`.
+ Added conversions from `Ptr`, `PtrMut`, and `OwningPtr` to `NonNull<u8>`.
2023-01-16 15:41:12 +00:00
James Liu
dfc4f05c87 Ensure Ptr/PtrMut/OwningPtr are aligned when casting in debug builds (#7117)
# Objective
Improve safety testing when using `bevy_ptr` types. This is a follow-up to #7113.

## Solution
Add a debug-only assertion that pointers are aligned when casting to a concrete type. This should very quickly catch any unsoundness from unaligned pointers, even without miri. However, this can have a large negative perf impact on debug builds.

---

## Changelog
Added: `Ptr::deref` will now panic in debug builds if the pointer is not aligned.
Added: `PtrMut::deref_mut` will now panic in debug builds if the pointer is not aligned.
Added: `OwningPtr::read` will now panic in debug builds if the pointer is not aligned.
Added: `OwningPtr::drop_as` will now panic in debug builds if the pointer is not aligned.
2023-01-11 23:12:20 +00:00
Boxy
512f376fc1 Document alignment requirements of Ptr, PtrMut and OwningPtr (#7151)
# Objective

The types in the `bevy_ptr` accidentally did not document anything relating to alignment. This is unsound as many methods rely on the pointer being correctly aligned. 

## Solution

This PR introduces new safety invariants on the `$ptr::new`, `$ptr::byte_offset` and `$ptr::byte_add` methods requiring them to keep the pointer aligned. This is consistent with the documentation of these pointer types which document them as being "type erased borrows".

As it was pointed out (by @JoJoJet in #7117) that working with unaligned pointers can be useful (for example our commands abstraction which does not try to align anything properly, see #7039) this PR also introduces a default type parameter to all the pointer types that specifies whether it has alignment requirements or not. I could not find any code in `bevy_ecs` that would need unaligned pointers right now so this is going unused.

---

## Changelog

- Correctly document alignment requirements on `bevy_ptr` types.
- Support variants of `bevy_ptr` types that do not require being correctly aligned for the pointee type.

## Migration Guide

- Safety invariants on `bevy_ptr` types' `new` `byte_add` and `byte_offset` methods have been changed. All callers should re-audit for soundness.
2023-01-10 23:12:52 +00:00
Nile
0ddaa7e83a Round out the untyped api s (#7009)
# Objective

Bevy uses custom `Ptr` types so the rust borrow checker can help ensure lifetimes are correct, even when types aren't known. However, these types don't benefit from the automatic lifetime coercion regular rust references enjoy

## Solution

Add a couple methods to Ptr, PtrMut, and MutUntyped to allow for easy usage of these types in more complex scenarios.

## Changelog

- Added `as_mut` and `as_ref` methods to `MutUntyped`.
- Added `shrink` and `as_ref` methods to `PtrMut`.

## Migration Guide

- `MutUntyped::into_inner` now marks things as changed.
2022-12-27 16:05:16 +00:00
0xc0001a2040
c38659ddea Add fmt::Pointer impl for bevy_ptr::{Ptr, PtrMut, OwnedPtr} (#6980)
# Objective

- `bevy_ptr::{Ptr, PtrMut, OwnedPtr}` wrap raw pointers and should be printable using pointer formatting.

## Solution

- Add a `core::fmt::Pointer` impl for `Ptr`, `PtrMut` and `OwnedPtr` based on the wrapped `NonNull` pointer.

---

## Changelog

- Added a `core::fmt::Pointer` impl to `Ptr`, `PtrMut` and `OwnedPtr`.

Co-authored-by: MrGunflame <mrgunflame@protonmail.com>
2022-12-20 23:18:13 +00:00
JoJoJet
f2f8f9097f Add safe constructors for untyped pointers Ptr and PtrMut (#6539)
# Objective

Currently, `Ptr` and `PtrMut` can only be constructed via unsafe code. This means that downgrading a reference to an untyped pointer is very cumbersome, despite being a very simple operation.

## Solution

Define conversions for easily and safely constructing untyped pointers. This is the non-owned counterpart to `OwningPtr::make`.

Before:

```rust
let ptr = unsafe { PtrMut::new(NonNull::from(&mut value).cast()) };
```

After:

```rust
let ptr = PtrMut::from(&mut value);
```


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-11-14 22:53:50 +00:00
JoJoJet
3ac06b57e9 Respect alignment for zero-sized types stored in the world (#6618)
# Objective

Fixes #6615.

`BlobVec` does not respect alignment for zero-sized types, which results in UB whenever a ZST with alignment other than 1 is used in the world.

## Solution

Add the fn `bevy_ptr::dangling_with_align`.

---

## Changelog

+ Added the function `dangling_with_align` to `bevy_ptr`, which creates a well-aligned dangling pointer to a type whose alignment is not known at compile time.
2022-11-14 21:16:53 +00:00
github-actions[bot]
920543c824 Release 0.9.0 (#6568)
Preparing next release
This PR has been auto-generated
2022-11-12 20:01:29 +00:00
github-actions[bot]
444150025d Bump Version after Release (#5576)
Bump version after release
This PR has been auto-generated
2022-08-05 02:03:05 +00:00
github-actions[bot]
856588ed7c Release 0.8.0 (#5490)
Preparing next release
This PR has been auto-generated
2022-07-30 14:07:30 +00:00
KDecay
222f2dd32c Fix OwningPtr docs (#5391)
# Objective

- Fix some small errors in the documentation of the `OwningPtr` struct.

## Solution

- Change comments with 4 slashes `////` to doc comments with 3 slashes `///`.
- Fix typos.
2022-07-20 13:16:28 +00:00
Jakob Hellermann
d38a8dfdd7 add more SAFETY comments and lint for missing ones in bevy_ecs (#4835)
# Objective

`SAFETY` comments are meant to be placed before `unsafe` blocks and should contain the reasoning of why in this case the usage of unsafe is okay. This is useful when reading the code because it makes it clear which assumptions are required for safety, and makes it easier to spot possible unsoundness holes. It also forces the code writer to think of something to write and maybe look at the safety contracts of any called unsafe methods again to double-check their correct usage.

There's a clippy lint called `undocumented_unsafe_blocks` which warns when using a block without such a comment. 

## Solution

- since clippy expects `SAFETY` instead of `SAFE`, rename those
- add `SAFETY` comments in more places
- for the last remaining 3 places, add an `#[allow()]` and `// TODO` since I wasn't comfortable enough with the code to justify their safety
- add ` #![warn(clippy::undocumented_unsafe_blocks)]` to `bevy_ecs`


### Note for reviewers

The first commit only renames `SAFETY` to `SAFE` so it doesn't need a thorough review.
cb042a416e..55cef2d6fa is the diff for all other changes.

### Safety comments where I'm not too familiar with the code

774012ece5/crates/bevy_ecs/src/entity/mod.rs (L540-L546)

774012ece5/crates/bevy_ecs/src/world/entity_ref.rs (L249-L252)

### Locations left undocumented with a `TODO` comment

5dde944a30/crates/bevy_ecs/src/schedule/executor_parallel.rs (L196-L199)

5dde944a30/crates/bevy_ecs/src/world/entity_ref.rs (L287-L289)

5dde944a30/crates/bevy_ecs/src/world/entity_ref.rs (L413-L415)

Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
2022-07-04 14:44:24 +00:00
Félix Lescaudey de Maneville
f000c2b951 Clippy improvements (#4665)
# Objective

Follow up to my previous MR #3718 to add new clippy warnings to bevy:

- [x] [~~option_if_let_else~~](https://rust-lang.github.io/rust-clippy/master/#option_if_let_else) (reverted)
- [x] [redundant_else](https://rust-lang.github.io/rust-clippy/master/#redundant_else)
- [x] [match_same_arms](https://rust-lang.github.io/rust-clippy/master/#match_same_arms)
- [x] [semicolon_if_nothing_returned](https://rust-lang.github.io/rust-clippy/master/#semicolon_if_nothing_returned)
- [x] [explicit_iter_loop](https://rust-lang.github.io/rust-clippy/master/#explicit_iter_loop)
- [x] [map_flatten](https://rust-lang.github.io/rust-clippy/master/#map_flatten)

There is one commit per clippy warning, and the matching flags are added to the CI execution.

To test the CI execution you may run `cargo run -p ci -- clippy` at the root.

I choose the add the flags in the `ci` tool crate to avoid having them in every `lib.rs` but I guess it could become an issue with suprise warnings coming up after a commit/push


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-05-31 01:38:07 +00:00
James Liu
eb2a8b12e9 bevy_ptr works in no_std environments (#4760)
# Objective
`bevy_ptr` works just fine without `std`. Mark it as `no_std`. This should generally be useful for non-bevy use cases, but it also marginally speeds up compilation by allowing the crate to compile without loading the std-lib.

## Solution
Replace `std` with `core`. Added `#![no_std]` to the crate and to the crate's tags.

Also added a missing `#![warn(missing_docs)]` that the other crates have.
2022-05-16 17:45:10 +00:00
Jakob Hellermann
d63b7e9568 some cleanup for bevy_ptr (#4668)
1. change `PtrMut::as_ptr(self)` and `OwnedPtr::as_ptr(self)` to take `&self`, otherwise printing the pointer will prevent doing anything else afterwards
2. make all `as_ptr` methods safe. There's nothing unsafe about obtaining a pointer, these kinds of methods are safe in std as well [str::as_ptr](https://doc.rust-lang.org/stable/std/primitive.str.html#method.as_ptr), [Rc::as_ptr](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.as_ptr)
3. rename `offset`/`add` to `byte_offset`/`byte_add`. The unprefixed methods in std add in increments of `std::mem::size_of::<T>`, not in bytes. There's a PR for rust to add these byte_ methods https://github.com/rust-lang/rust/pull/95643 and at the call site it makes it much more clear that you need to do `.byte_add(i * layout_size)` instead of `.add(i)`
2022-05-06 19:15:24 +00:00
Jakob Hellermann
1e322d9f76 bevy_ptr standalone crate (#4653)
# Objective

The pointer types introduced in #3001 are useful not just in `bevy_ecs`, but also in crates like `bevy_reflect` (#4475) or even outside of bevy.

## Solution

Extract `Ptr<'a>`, `PtrMut<'a>`, `OwnedPtr<'a>`, `ThinSlicePtr<'a, T>` and `UnsafeCellDeref` from `bevy_ecs::ptr` into `bevy_ptr`.

**Note:** `bevy_ecs` still reexports the `bevy_ptr` as `bevy_ecs::ptr` so that crates like `bevy_transform` can use the `Bundle` derive without needing to depend on `bevy_ptr` themselves.
2022-05-04 19:16:10 +00:00