This pr uses the `extern crate self as` trick to make proc macros behave
the same way inside and outside bevy.
# Objective
- Removes noise introduced by `crate as` in the whole bevy repo.
- Fixes#17004.
- Hardens proc macro path resolution.
## TODO
- [x] `BevyManifest` needs cleanup.
- [x] Cleanup remaining `crate as`.
- [x] Add proper integration tests to the ci.
## Notes
- `cargo-manifest-proc-macros` is written by me and based/inspired by
the old `BevyManifest` implementation and
[`bkchr/proc-macro-crate`](https://github.com/bkchr/proc-macro-crate).
- What do you think about the new integration test machinery I added to
the `ci`?
More and better integration tests can be added at a later stage.
The goal of these integration tests is to simulate an actual separate
crate that uses bevy. Ideally they would lightly touch all bevy crates.
## Testing
- Needs RA test
- Needs testing from other users
- Others need to run at least `cargo run -p ci integration-test` and
verify that they work.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
We want to deny the following lints:
* `clippy::allow_attributes` - Because there's no reason to
`#[allow(...)]` an attribute if it wouldn't lint against anything; you
should always use `#[expect(...)]`
* `clippy::allow_attributes_without_reason` - Because documenting the
reason for allowing/expecting a lint is always good
## Solution
Set the `clippy::allow_attributes` and
`clippy::allow_attributes_without_reason` lints to `deny`, and bring
`bevy_reflect` in line with the new restrictions.
No code changes have been made - except if a lint that was previously
`allow(...)`'d could be removed via small code changes. For example,
`unused_variables` can be handled by adding a `_` to the beginning of a
field's name.
## Testing
I ran `cargo clippy`, and received no errors.
# Background
In `no_std` compatible crates, there is often an `std` feature which
will allow access to the standard library. Currently, with the `std`
feature _enabled_, the
[`std::prelude`](https://doc.rust-lang.org/std/prelude/index.html) is
implicitly imported in all modules. With the feature _disabled_, instead
the [`core::prelude`](https://doc.rust-lang.org/core/prelude/index.html)
is implicitly imported. This creates a subtle and pervasive issue where
`alloc` items _may_ be implicitly included (if `std` is enabled), or
must be explicitly included (if `std` is not enabled).
# Objective
- Make the implicit imports for `no_std` crates consistent regardless of
what features are/not enabled.
## Solution
- Replace the `cfg_attr` "double negative" `no_std` attribute with
conditional compilation to _include_ `std` as an external crate.
```rust
// Before
#![cfg_attr(not(feature = "std"), no_std)]
// After
#![no_std]
#[cfg(feature = "std")]
extern crate std;
```
- Fix imports that are currently broken but are only now visible with
the above fix.
## Testing
- CI
## Notes
I had previously used the "double negative" version of `no_std` based on
general consensus that it was "cleaner" within the Rust embedded
community. However, this implicit prelude issue likely was considered
when forming this consensus. I believe the reason why is the items most
affected by this issue are provided by the `alloc` crate, which is
rarely used within embedded but extensively used within Bevy.
# Objective
- Contributes to #15460
## Solution
- Added `std` feature (enabled by default)
## Testing
- CI
- `cargo check -p bevy_reflect --no-default-features --target
"x86_64-unknown-none"`
- UEFI demo application runs with this branch of `bevy_reflect`,
allowing `derive(Reflect)`
## Notes
- The [`spin`](https://crates.io/crates/spin) crate has been included to
provide `RwLock` and `Once` (as an alternative to `OnceLock`) when the
`std` feature is not enabled. Another alternative may be more desirable,
please provide feedback if you have a strong opinion here!
- Certain items (`Box`, `String`, `ToString`) provided by `alloc` have
been added to `__macro_exports` as a way to avoid `alloc` vs `std`
namespacing. I'm personally quite annoyed that we can't rely on `alloc`
as a crate name in `std` environments within macros. I'd love an
alternative to my approach here, but I suspect it's the least-bad
option.
- I would've liked to have an `alloc` feature (for allocation-free
`bevy_reflect`), unfortunately, `erased_serde` unconditionally requires
access to `Box`. Maybe one day we could design around this, but for now
it just means `bevy_reflect` requires `alloc`.
---------
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Fixes#6370
- Closes#6581
## Solution
- Added the following lints to the workspace:
- `std_instead_of_core`
- `std_instead_of_alloc`
- `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.
## Testing
- Ran CI locally
## Migration Guide
The MSRV is now 1.81. Please update to this version or higher.
## Notes
- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Bevy currently has lot of invalid intra-doc links, let's fix them!
- Also make CI test them, to avoid future regressions.
- Helps with #1983 (but doesn't fix it, as there could still be explicit
links to docs.rs that are broken)
## Solution
- Make `cargo r -p ci -- doc-check` check fail on warnings (could also
be changed to just some specific lints)
- Manually fix all the warnings (note that in some cases it was unclear
to me what the fix should have been, I'll try to highlight them in a
self-review)
# Objective
As work on the editor starts to ramp up, it might be nice to start
allowing types to specify custom attributes. These can be used to
provide certain functionality to fields, such as ranges or controlling
how data is displayed.
A good example of this can be seen in
[`bevy-inspector-egui`](https://github.com/jakobhellermann/bevy-inspector-egui)
with its
[`InspectorOptions`](https://docs.rs/bevy-inspector-egui/0.22.1/bevy_inspector_egui/struct.InspectorOptions.html):
```rust
#[derive(Reflect, Default, InspectorOptions)]
#[reflect(InspectorOptions)]
struct Slider {
#[inspector(min = 0.0, max = 1.0)]
value: f32,
}
```
Normally, as demonstrated in the example above, these attributes are
handled by a derive macro and stored in a corresponding `TypeData`
struct (i.e. `ReflectInspectorOptions`).
Ideally, we would have a good way of defining this directly via
reflection so that users don't need to create and manage a whole proc
macro just to allow these sorts of attributes.
And note that this doesn't have to just be for inspectors and editors.
It can be used for things done purely on the code side of things.
## Solution
Create a new method for storing attributes on fields via the `Reflect`
derive.
These custom attributes are stored in type info (e.g. `NamedField`,
`StructInfo`, etc.).
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(@0.0..=1.0)]
value: f64,
}
let TypeInfo::Struct(info) = Slider::type_info() else {
panic!("expected struct info");
};
let field = info.field("value").unwrap();
let range = field.get_attribute::<RangeInclusive<f64>>().unwrap();
assert_eq!(*range, 0.0..=1.0);
```
## TODO
- [x] ~~Bikeshed syntax~~ Went with a type-based approach, prefixed by
`@` for ease of parsing and flexibility
- [x] Add support for custom struct/tuple struct field attributes
- [x] Add support for custom enum variant field attributes
- [x] ~~Add support for custom enum variant attributes (maybe?)~~ ~~Will
require a larger refactor. Can be saved for a future PR if we really
want it.~~ Actually, we apparently still have support for variant
attributes despite not using them, so it was pretty easy to add lol.
- [x] Add support for custom container attributes
- [x] Allow custom attributes to store any reflectable value (not just
`Lit`)
- [x] ~~Store attributes in registry~~ This PR used to store these in
attributes in the registry, however, it has since switched over to
storing them in type info
- [x] Add example
## Bikeshedding
> [!note]
> This section was made for the old method of handling custom
attributes, which stored them by name (i.e. `some_attribute = 123`). The
PR has shifted away from that, to a more type-safe approach.
>
> This section has been left for reference.
There are a number of ways we can syntactically handle custom
attributes. Feel free to leave a comment on your preferred one! Ideally
we want one that is clear, readable, and concise since these will
potentially see _a lot_ of use.
Below is a small, non-exhaustive list of them. Note that the
`skip_serializing` reflection attribute is added to demonstrate how each
case plays with existing reflection attributes.
<details>
<summary>List</summary>
##### 1. `@(name = value)`
> The `@` was chosen to make them stand out from other attributes and
because the "at" symbol is a subtle pneumonic for "attribute". Of
course, other symbols could be used (e.g. `$`, `#`, etc.).
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(@(min = 0.0, max = 1.0), skip_serializing)]
#[[reflect(@(bevy_editor::hint = "Range: 0.0 to 1.0"))]
value: f32,
}
```
##### 2. `@name = value`
> This is my personal favorite.
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(@min = 0.0, @max = 1.0, skip_serializing)]
#[[reflect(@bevy_editor::hint = "Range: 0.0 to 1.0")]
value: f32,
}
```
##### 3. `custom_attr(name = value)`
> `custom_attr` can be anything. Other possibilities include `with` or
`tag`.
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(custom_attr(min = 0.0, max = 1.0), skip_serializing)]
#[[reflect(custom_attr(bevy_editor::hint = "Range: 0.0 to 1.0"))]
value: f32,
}
```
##### 4. `reflect_attr(name = value)`
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(skip_serializing)]
#[reflect_attr(min = 0.0, max = 1.0)]
#[[reflect_attr(bevy_editor::hint = "Range: 0.0 to 1.0")]
value: f32,
}
```
</details>
---
## Changelog
- Added support for custom attributes on reflected types (i.e.
`#[reflect(@Foo::new("bar")]`)
