Commit Graph

121 Commits

Author SHA1 Message Date
andriyDev
0381a798e2
Delete System::component_access(). (#19496)
# Objective

- Cleanup related to #19495.

## Solution

- Delete `System::component_access()`. It is redundant with
`System::component_access_set().combined_access()`.

## Testing

- None. There are no callers of this function.
2025-06-09 22:54:52 +00:00
re0312
56f26cfb02
Unify system state (#19506)
# Objective

- A preparation for the 'system as entities'
- The current system has a series of states such as `is_send`,
`is_exclusive`, `has_defered`, As `system as entites` landed, it may
have more states. Using Bitflags to unify all states is a more concise
and performant approach

## Solution

- Using Bitflags to  unify system state.
2025-06-08 18:18:43 +00:00
François Mockers
7a7bff8c17
Hot patching systems with subsecond (#19309)
# Objective

- Enable hot patching systems with subsecond
- Fixes #19296 

## Solution

- First commit is the naive thin layer
- Second commit only check the jump table when the code is hot patched
instead of on every system execution
- Depends on https://github.com/DioxusLabs/dioxus/pull/4153 for a nicer
API, but could be done without
- Everything in second commit is feature gated, it has no impact when
the feature is not enabled

## Testing

- Check dependencies without the feature enabled: nothing dioxus in tree
- Run the new example: text and color can be changed

---------

Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>
Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
2025-06-03 21:12:38 +00:00
Chris Russell
571b3ba475
Remove ArchetypeComponentId and archetype_component_access (#19143)
# Objective

Remove `ArchetypeComponentId` and `archetype_component_access`.
Following #16885, they are no longer used by the engine, so we can stop
spending time calculating them or space storing them.

## Solution

Remove `ArchetypeComponentId` and everything that touches it.  

The `System::update_archetype_component_access` method no longer needs
to update `archetype_component_access`. We do still need to update query
caches, but we no longer need to do so *before* running the system. We'd
have to touch every caller anyway if we gave the method a better name,
so just remove `System::update_archetype_component_access` and
`SystemParam::new_archetype` entirely, and update the query cache in
`Query::get_param`.

The `Single` and `Populated` params also need their query caches updated
in `SystemParam::validate_param`, so change `validate_param` to take
`&mut Self::State` instead of `&Self::State`.
2025-05-27 19:04:32 +00:00
urben1680
732b2e0c79
Track spawn Tick of entities, offer methods, query data SpawnDetails and query filter Spawned (#19047)
# Objective

In my own project I was encountering the issue to find out which
entities were spawned after applying commands. I began maintaining a
vector of all entities with generational information before and after
applying the command and diffing it. This was awfully complicated though
and has no constant complexity but grows with the number of entities.

## Solution

Looking at `EntyMeta` it seemed obvious to me that struct can track the
tick just as it does with `MaybeLocation`, updated from the same call.
After that it became almost a given to also introduce query data
`SpawnDetails` which offers methods to get the spawn tick and location,
and query filter `Spawned` that filters entities out that were not
spawned since the last run.

## Testing

I expanded a few tests and added new ones, though maybe I forgot a group
of tests that should be extended too. I basically searched `bevy_ecs`
for mentions of `Changed` and `Added` to see where the tests and docs
are.

Benchmarks of spawn/despawn can be found
[here](https://github.com/bevyengine/bevy/pull/19047#issuecomment-2852181374).

---

## Showcase

From the added docs, systems with equal complexity since the filter is
not archetypal:
```rs
fn system1(q: Query<Entity, Spawned>) {
    for entity in &q { /* entity spawned */ }
}

fn system2(query: Query<(Entity, SpawnDetails)>) {
    for (entity, spawned) in &query {
        if spawned.is_spawned() { /* entity spawned */ }
    }
}
```

`SpawnedDetails` has a few more methods:

```rs
fn print_spawn_details(query: Query<(Entity, SpawnDetails)>) {
    for (entity, spawn_details) in &query {
        if spawn_details.is_spawned() {
            print!("new ");
        }
        println!(
            "entity {:?} spawned at {:?} by {:?}",
            entity,
            spawn_details.spawned_at(),
            spawn_details.spawned_by()
        );        
    }
}
```

## Changes

No public api was changed, I only added to it. That is why I added no
migration guide.

- query data `SpawnDetails`
- query filter `Spawned`
- method `Entities::entity_get_spawned_or_despawned_at`
- method `EntityRef::spawned_at`
- method `EntityMut::spawned_at`
- method `EntityWorldMut::spawned_at`
- method `UnsafeEntityCell::spawned_at`
- method `FilteredEntityRef::spawned_at`
- method `FilteredEntityMut::spawned_at`
- method `EntityRefExcept::spawned_at`
- method `EntityMutExcept::spawned_at`

---------

Co-authored-by: Eagster <79881080+ElliottjPierce@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-05-08 14:57:33 +00:00
Chris Russell
55bb59b844
Stop using ArchetypeComponentId in the executor (#16885)
# Objective

Stop using `ArchetypeComponentId` in the executor. These IDs will grow
even more quickly with relations, and the size may start to degrade
performance.

## Solution

Have systems expose their `FilteredAccessSet<ComponentId>`, and have the
executor use that to determine which systems conflict. This can be
determined statically, so determine all conflicts during initialization
and only perform bit tests when running.

## Testing

I ran many_foxes and didn't see any performance changes. It's probably
worth testing this with a wider range of realistic schedules to see
whether the reduced concurrency has a cost in practice, but I don't know
what sort of test cases to use.

## Migration Guide

The schedule will now prevent systems from running in parallel if there
*could* be an archetype that they conflict on, even if there aren't
actually any. For example, these systems will now conflict even if no
entity has both `Player` and `Enemy` components:
```rust
fn player_system(query: Query<(&mut Transform, &Player)>) {}
fn enemy_system(query: Query<(&mut Transform, &Enemy)>) {}
```

To allow them to run in parallel, use `Without` filters, just as you
would to allow both queries in a single system:
```rust
// Either one of these changes alone would be enough
fn player_system(query: Query<(&mut Transform, &Player), Without<Enemy>>) {}
fn enemy_system(query: Query<(&mut Transform, &Enemy), Without<Player>>) {}
```
2025-05-05 22:52:44 +00:00
lcnr
d7ec6a90f2
remove reliance on a trait solver inference bug (#18840)
The parameter `In` of `call_inner` is completely unconstrained by its
arguments and return type. We are only able to infer it by assuming that
the only associated type equal to `In::Param<'_>` is `In::Param<'_>`
itself. It could just as well be some other associated type which only
normalizes to `In::Param<'_>`. This will change with the next-generation
trait solver and was encountered by a crater run
https://github.com/rust-lang/rust/pull/133502-

cc
https://github.com/rust-lang/trait-system-refactor-initiative/issues/168

I couldn't think of a cleaner alternative here. I first tried to just
provide `In` as an explicit type parameter. This is also kinda ugly as I
need to provide a variable number of them and `${ignore(..)}` is
currently still unstable https://github.com/rust-lang/rust/issues/83527.

Sorry for the inconvenience. Also fun that this function exists to avoid
a separate solver bug in the first place 😅
2025-04-14 19:55:31 +00:00
Chris Russell
837991a5b5
Replace ValidationOutcome with Result (#18541)
# Objective

Make it easier to short-circuit system parameter validation.  

Simplify the API surface by combining `ValidationOutcome` with
`SystemParamValidationError`.

## Solution

Replace `ValidationOutcome` with `Result<(),
SystemParamValidationError>`. Move the docs from `ValidationOutcome` to
`SystemParamValidationError`.

Add a `skipped` field to `SystemParamValidationError` to distinguish the
`Skipped` and `Invalid` variants.

Use the `?` operator to short-circuit validation in tuples of system
params.
2025-03-26 03:36:16 +00:00
Alice Cecile
6a981aaa6f
Define system param validation on a per-system parameter basis (#18504)
# Objective

When introduced, `Single` was intended to simply be silently skipped,
allowing for graceful and efficient handling of systems during invalid
game states (such as when the player is dead).

However, this also caused missing resources to *also* be silently
skipped, leading to confusing and very hard to debug failures. In
0.15.1, this behavior was reverted to a panic, making missing resources
easier to debug, but largely making `Single` (and `Populated`)
worthless, as they would panic during expected game states.

Ultimately, the consensus is that this behavior should differ on a
per-system-param basis. However, there was no sensible way to *do* that
before this PR.

## Solution

Swap `SystemParam::validate_param` from a `bool` to:

```rust
/// The outcome of system / system param validation,
/// used by system executors to determine what to do with a system.
pub enum ValidationOutcome {
    /// All system parameters were validated successfully and the system can be run.
    Valid,
    /// At least one system parameter failed validation, and an error must be handled.
    /// By default, this will result in1 a panic. See [crate::error] for more information.
    ///
    /// This is the default behavior, and is suitable for system params that should *always* be valid,
    /// either because sensible fallback behavior exists (like [`Query`] or because
    /// failures in validation should be considered a bug in the user's logic that must be immediately addressed (like [`Res`]).
    Invalid,
    /// At least one system parameter failed validation, but the system should be skipped due to [`ValidationBehavior::Skip`].
    /// This is suitable for system params that are intended to only operate in certain application states, such as [`Single`].
    Skipped,
}
```
Then, inside of each `SystemParam` implementation, return either Valid,
Invalid or Skipped.

Currently, only `Single`, `Option<Single>` and `Populated` use the
`Skipped` behavior. Other params (like resources) retain their current
failing

## Testing

Messed around with the fallible_params example. Added a pair of tests:
one for panicking when resources are missing, and another for properly
skipping `Single` and `Populated` system params.

## To do

- [x] get https://github.com/bevyengine/bevy/pull/18454 merged
- [x] fix the todo!() in the macro-powered tuple implementation (please
help 🥺)
- [x] test
- [x] write a migration guide
- [x] update the example comments

## Migration Guide

Various system and system parameter validation methods
(`SystemParam::validate_param`, `System::validate_param` and
`System::validate_param_unsafe`) now return and accept a
`ValidationOutcome` enum, rather than a `bool`. The previous `true`
values map to `ValidationOutcome::Valid`, while `false` maps to
`ValidationOutcome::Invalid`.

However, if you wrote a custom schedule executor, you should now respect
the new `ValidationOutcome::Skipped` parameter, skipping any systems
whose validation was skipped. By contrast, `ValidationOutcome::Invalid`
systems should also be skipped, but you should call the
`default_error_handler` on them first, which by default will result in a
panic.

If you are implementing a custom `SystemParam`, you should consider
whether failing system param validation is an error or an expected
state, and choose between `Invalid` and `Skipped` accordingly. In Bevy
itself, `Single` and `Populated` now once again skip the system when
their conditions are not met. This is the 0.15.0 behavior, but stands in
contrast to the 0.15.1 behavior, where they would panic.

---------

Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Co-authored-by: Dmytro Banin <banind@cs.washington.edu>
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
2025-03-25 04:27:20 +00:00
Alice Cecile
ce7d4e41d6
Make system param validation rely on the unified ECS error handling via the GLOBAL_ERROR_HANDLER (#18454)
# Objective

There are two related problems here:

1. Users should be able to change the fallback behavior of *all*
ECS-based errors in their application by setting the
`GLOBAL_ERROR_HANDLER`. See #18351 for earlier work in this vein.
2. The existing solution (#15500) for customizing this behavior is high
on boilerplate, not global and adds a great deal of complexity.

The consensus is that the default behavior when a parameter fails
validation should be set based on the kind of system parameter in
question: `Single` / `Populated` should silently skip the system, but
`Res` should panic. Setting this behavior at the system level is a
bandaid that makes getting to that ideal behavior more painful, and can
mask real failures (if a resource is missing but you've ignored a system
to make the Single stop panicking you're going to have a bad day).

## Solution

I've removed the existing `ParamWarnPolicy`-based configuration, and
wired up the `GLOBAL_ERROR_HANDLER`/`default_error_handler` to the
various schedule executors to properly plumb through errors .

Additionally, I've done a small cleanup pass on the corresponding
example.

## Testing

I've run the `fallible_params` example, with both the default and a
custom global error handler. The former panics (as expected), and the
latter spams the error console with warnings 🥲

## Questions for reviewers

1. Currently, failed system param validation will result in endless
console spam. Do you want me to implement a solution for warn_once-style
debouncing somehow?
2. Currently, the error reporting for failed system param validation is
very limited: all we get is that a system param failed validation and
the name of the system. Do you want me to implement improved error
reporting by bubbling up errors in this PR?
3. There is broad consensus that the default behavior for failed system
param validation should be set on a per-system param basis. Would you
like me to implement that in this PR?

My gut instinct is that we absolutely want to solve 2 and 3, but it will
be much easier to do that work (and review it) if we split the PRs
apart.

## Migration Guide

`ParamWarnPolicy` and the `WithParamWarnPolicy` have been removed
completely. Failures during system param validation are now handled via
the `GLOBAL_ERROR_HANDLER`: please see the `bevy_ecs::error` module docs
for more information.

---------

Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
2025-03-24 05:58:05 +00:00
Alice Cecile
0ca9d6968a
Improve docs for WorldQuery (#17654)
# Objective

While working on #17649, I found the docs for `WorldQuery` and the
related traits frustratingly vague.

## Solution

Clarify them and add some more tangible advice.

Also fix a copy-pasted typo in related comments.

---------

Co-authored-by: James O'Brien <james.obrien@drafly.net>
2025-02-03 22:13:42 +00:00
MichiRecRoom
17c46f4add
bevy_ecs: Apply #![warn(clippy::allow_attributes, clippy::allow_attributes_without_reason)] (#17335)
# Objective
- https://github.com/bevyengine/bevy/issues/17111

## Solution
Set the `clippy::allow_attributes` and
`clippy::allow_attributes_without_reason` lints to `warn`, and bring
`bevy_ecs` in line with the new restrictions.

## Testing
This PR is a WIP; testing will happen after it's finished.
2025-01-14 21:37:41 +00:00
AlephCubed
e808fbe987
Renamed members of ParamWarnPolicy to reflect new behaviour. (#17311)
- `Once` renamed to `Warn`.
- `param_warn_once()` renamed to `warn_param_missing()`.
- `never_param_warn()` renamed to `ignore_param_missing()`.

Also includes changes to the documentation of the above methods.

Fixes #17262.

## Migration Guide
- `ParamWarnPolicy::Once` has been renamed to `ParamWarnPolicy::Warn`.
- `ParamWarnPolicy::param_warn_once` has been renamed to
`ParamWarnPolicy::warn_param_missing`.
- `ParamWarnPolicy::never_param_warn` has been renamed to
`ParamWarnPolicy::ignore_param_missing`.
2025-01-12 05:40:04 +00:00
MichiRecRoom
3742e621ef
Allow clippy::too_many_arguments to lint without warnings (#17249)
# Objective
Many instances of `clippy::too_many_arguments` linting happen to be on
systems - functions which we don't call manually, and thus there's not
much reason to worry about the argument count.

## Solution
Allow `clippy::too_many_arguments` globally, and remove all lint
attributes related to it.
2025-01-09 07:26:15 +00:00
Zhixing Zhang
9cebc66486
Make 8 methods public and updated input parameter generics for SystemState::build_system_with_input (#17034)
# Objective

- Made certain methods public for advanced use cases. Methods that
returns mutable references are marked as unsafe due to the possibility
of violating internal lifetime constraint assumptions.
- Fixes an issue introduced by #15184
2024-12-30 23:04:14 +00:00
MiniaczQ
460de77a55
Set panic as default fallible system param behavior (#16638)
# Objective

Fixes: #16578

## Solution

This is a patch fix, proper fix requires a breaking change.

Added `Panic` enum variant and using is as the system meta default.
Warn once behavior can be enabled same way disabling panic (originally
disabling wans) is.

To fix an issue with the current architecture, where **all** combinator
system params get checked together,
combinator systems only check params of the first system.
This will result in old, panicking behavior on subsequent systems and
will be fixed in 0.16.

## Testing

Ran unit tests and `fallible_params` example.

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
2024-12-24 02:36:03 +00:00
Zachary Harrold
1f2d0e6308
Add no_std support to bevy_ecs (#16758)
# Objective

- Contributes to #15460

## Solution

- Added the following features:
  - `std` (default)
  - `async_executor` (default)
  - `edge_executor`
  - `critical-section`
  - `portable-atomic`
- Gated `tracing` in `bevy_utils` to allow compilation on certain
platforms
- Switched from `tracing` to `log` for simple message logging within
`bevy_ecs`. Note that `tracing` supports capturing from `log` so this
should be an uncontroversial change.
- Fixed imports and added feature gates as required 
- Made `bevy_tasks` optional within `bevy_ecs`. Turns out it's only
needed for parallel operations which are already gated behind
`multi_threaded` anyway.

## Testing

- Added to `compile-check-no-std` CI command
- `cargo check -p bevy_ecs --no-default-features --features
edge_executor,critical-section,portable-atomic --target
thumbv6m-none-eabi`
- `cargo check -p bevy_ecs --no-default-features --features
edge_executor,critical-section`
- `cargo check -p bevy_ecs --no-default-features`

## Draft Release Notes

Bevy's core ECS now supports `no_std` platforms.

In prior versions of Bevy, it was not possible to work with embedded or
niche platforms due to our reliance on the standard library, `std`. This
has blocked a number of novel use-cases for Bevy, such as an embedded
database for IoT devices, or for creating games on retro consoles.

With this release, `bevy_ecs` no longer requires `std`. To use Bevy on a
`no_std` platform, you must disable default features and enable the new
`edge_executor` and `critical-section` features. You may also need to
enable `portable-atomic` and `critical-section` if your platform does
not natively support all atomic types and operations used by Bevy.

```toml
[dependencies]
bevy_ecs = { version = "0.16", default-features = false, features = [
  # Required for platforms with incomplete atomics (e.g., Raspberry Pi Pico)
  "portable-atomic",
  "critical-section",

  # Optional
  "bevy_reflect",
  "serialize",
  "bevy_debug_stepping",
  "edge_executor"
] }
```

Currently, this has been tested on bare-metal x86 and the Raspberry Pi
Pico. If you have trouble using `bevy_ecs` on a particular platform,
please reach out either through a GitHub issue or in the `no_std`
working group on the Bevy Discord server.

Keep an eye out for future `no_std` updates as we continue to improve
the parity between `std` and `no_std`. We look forward to seeing what
kinds of applications are now possible with Bevy!

## Notes

- Creating PR in draft to ensure CI is passing before requesting
reviews.
- This implementation has no support for multithreading in `no_std`,
especially due to `NonSend` being unsound if allowed in multithreading.
The reason is we cannot check the `ThreadId` in `no_std`, so we have no
mechanism to at-runtime determine if access is sound.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Vic <59878206+Victoronz@users.noreply.github.com>
2024-12-17 21:40:36 +00:00
Christian Hughes
f87b9fe20c
Turn apply_deferred into a ZST System (#16642)
# Objective

- Required by #16622 due to differing implementations of `System` by
`FunctionSystem` and `ExclusiveFunctionSystem`.
- Optimize the memory usage of instances of `apply_deferred` in system
schedules.

## Solution

By changing `apply_deferred` from being an ordinary system that ends up
as an `ExclusiveFunctionSystem`, and instead into a ZST struct that
implements `System` manually, we save ~320 bytes per instance of
`apply_deferred` in any schedule.

## Testing

- All current tests pass.

---

## Migration Guide

- If you were previously calling the special `apply_deferred` system via
`apply_deferred(world)`, don't.
2024-12-05 18:14:05 +00:00
vil'mo
67bd2b00e1
Expose SystemMeta's access field as part of public API (#16625)
# Objective

Outside of the `bevy_ecs` crate it's hard to implement `SystemParam`
trait on params that require access to the `World`, because `init_state`
expects user to extend access in `SystemMeta` and access-related fields
of `SystemMeta` are private.

## Solution

Expose those fields as a functions
2024-12-05 18:10:58 +00:00
Benjamin Brienen
afd0f1322d
Move all_tuples to a new crate (#16161)
# Objective

Fixes #15941

## Solution

Created https://crates.io/crates/variadics_please and moved the code
there; updating references

`bevy_utils/macros` is deleted.

## Testing

cargo check

## Migration Guide

Use `variadics_please::{all_tuples, all_tuples_with_size}` instead of
`bevy::utils::{all_tuples, all_tuples_with_size}`.
2024-12-03 17:41:09 +00:00
Christian Hughes
6fe4b1440c
Refactor FunctionSystem to use a single Option (#16514)
# Objective

Combine the `Option<_>` state in `FunctionSystem` into a single `Option`
to provide clarity and save space.

## Solution

Simplifies `FunctionSystem`'s layout by using a single
`Option<FunctionSystemState>` for state that must be initialized before
running, and saves a byte by removing the need to store an enum tag.
Additionally, calling `System::run` on an uninitialized `System` will
now give a more descriptive message prior to verifying the `WorldId`.

## Testing

Ran CI checks locally.
2024-12-01 20:09:22 +00:00
Tau Gärtli
a644ac73f7
More #[doc(fake_variadic)] goodness (#16108)
This PR adds `#[doc(fake_variadic)]` to that were previously not
supported by rustdoc.

Thanks to an [upstream
contribution](https://github.com/rust-lang/rust/pull/132115) by yours
truly, `#[doc(fake_variadic)]` is now supported on impls such as `impl
QueryData for AnyOf<(T, ...)>` 🎉
Requires the latest nightly compiler (2024-10-25) which is already
available on [docs.rs](https://docs.rs/about/builds).


![image](https://github.com/user-attachments/assets/68589c7e-f68f-44fb-9a7b-09d24ccf19c9)

![image](https://github.com/user-attachments/assets/f09d20d6-d89b-471b-9a81-4a72c8968178)

This means that the impl sections for `QueryData` and `QueryFilter` are
now nice and tidy 

---

I also added `fake_variadic` to some impls that use
`all_tuples_with_size`, however I'm not entirely happy because the docs
are slightly misleading now:


![image](https://github.com/user-attachments/assets/fac93d08-dc02-430f-9f34-c97456256c56)

Note that the docs say `IntoBindGroupLayoutEntryBuilderArray<1>` instead
of
`IntoBindGroupLayoutEntryBuilderArray<N>`.
2024-10-27 19:01:50 +00:00
Rob Parrett
30d84519a2
Use en-us locale for typos (#16037)
# Objective

Bevy seems to want to standardize on "American English" spellings. Not
sure if this is laid out anywhere in writing, but see also #15947.

While perusing the docs for `typos`, I noticed that it has a `locale`
config option and tried it out.

## Solution

Switch to `en-us` locale in the `typos` config and run `typos -w`

## Migration Guide

The following methods or fields have been renamed from `*dependants*` to
`*dependents*`.

- `ProcessorAssetInfo::dependants`
- `ProcessorAssetInfos::add_dependant`
- `ProcessorAssetInfos::non_existent_dependants`
- `AssetInfo::dependants_waiting_on_load`
- `AssetInfo::dependants_waiting_on_recursive_dep_load`
- `AssetInfos::loader_dependants`
- `AssetInfos::remove_dependants_and_labels`
2024-10-20 18:55:17 +00:00
Rob Parrett
da5d2fccf5
Fix some duplicate words in docs/comments (#15980)
# Objective

Stumbled upon one of these, and set off in search of more, armed with my
trusty `\b(\w+)\s+\1\b`.

## Solution

Remove ~one~ one of them.
2024-10-20 01:03:27 +00:00
MiniaczQ
acea4e7e6f
Better warnings about invalid parameters (#15500)
# Objective

System param validation warnings should be configurable and default to
"warn once" (per system).

Fixes: #15391

## Solution

`SystemMeta` is given a new `ParamWarnPolicy` field.
The policy decides whether warnings will be emitted by each system param
when it fails validation.
The policy is updated by the system after param validation fails.

Example warning:
```
2024-09-30T18:10:04.740749Z  WARN bevy_ecs::system::function_system: System fallible_params::do_nothing_fail_validation will not run because it requested inaccessible system parameter Single<(), (With<Player>, With<Enemy>)>
```

Currently, only the first invalid parameter is displayed.

Warnings can be disabled on function systems using
`.param_never_warn()`.
(there is also `.with_param_warn_policy(policy)`)

## Testing

Ran `fallible_params` example.

---------

Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
2024-10-03 13:16:55 +00:00
Zachary Harrold
d70595b667
Add core and alloc over std Lints (#15281)
# 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>
2024-09-27 00:59:59 +00:00
Christian Hughes
c7ec456e50
Support systems that take references as input (#15184)
# Objective

- Fixes #14924
- Closes #9584

## Solution

- We introduce a new trait, `SystemInput`, that serves as a type
function from the `'static` form of the input, to its lifetime'd
version, similarly to `SystemParam` or `WorldQuery`.
- System functions now take the lifetime'd wrapped version,
`SystemInput::Param<'_>`, which prevents the issue presented in #14924
(i.e. `InRef<T>`).
- Functions for running systems now take the lifetime'd unwrapped
version, `SystemInput::Inner<'_>` (i.e. `&T`).
- Due to the above change, system piping had to be re-implemented as a
standalone type, rather than `CombinatorSystem` as it was previously.
- Removes the `Trigger<'static, E, B>` transmute in observer runner
code.

## Testing

- All current tests pass.
- Added additional tests and doc-tests.

---

## Showcase

```rust
let mut world = World::new();

let mut value = 2;

// Currently possible:
fn square(In(input): In<usize>) -> usize {
    input * input
}
value = world.run_system_once_with(value, square);

// Now possible:
fn square_mut(InMut(input): InMut<usize>) {
    *input *= *input;
}
world.run_system_once_with(&mut value, square_mut);

// Or:
fn square_ref(InRef(input): InRef<usize>) -> usize {
    *input * *input
}
value = world.run_system_once_with(&value, square_ref);
```

## Migration Guide

- All current explicit usages of the following types must be changed in
the way specified:
    - `SystemId<I, O>` to `SystemId<In<I>, O>`
    - `System<In = T>` to `System<In = In<T>>`
    - `IntoSystem<I, O, M>` to `IntoSystem<In<I>, O, M>`
    - `Condition<M, T>` to `Condition<M, In<T>>`
- `In<Trigger<E, B>>` is no longer a valid input parameter type. Use
`Trigger<E, B>` directly, instead.

---------

Co-authored-by: Giacomo Stevanato <giaco.stevanato@gmail.com>
2024-09-23 17:37:29 +00:00
MiniaczQ
e312da8c52
Reduce runtime panics through SystemParam validation (#15276)
# Objective

The goal of this PR is to introduce `SystemParam` validation in order to
reduce runtime panics.

Fixes #15265

## Solution

`SystemParam` now has a new method `validate_param(...) -> bool`, which
takes immutable variants of `get_param` arguments. The returned value
indicates whether the parameter can be acquired from the world. If
parameters cannot be acquired for a system, it won't be executed,
similarly to run conditions. This reduces panics when using params like
`Res`, `ResMut`, etc. as well as allows for new, ergonomic params like
#15264 or #15302.

Param validation happens at the level of executors. All validation
happens directly before executing a system, in case of normal systems
they are skipped, in case of conditions they return false.

Warning about system skipping is primitive and subject to change in
subsequent PRs.

## Testing

Two executor tests check that all executors:
- skip systems which have invalid parameters:
  - piped systems get skipped together,
  - dependent systems still run correctly,
- skip systems with invalid run conditions:
  - system conditions have invalid parameters,
  - system set conditions have invalid parameters.
2024-09-23 16:54:21 +00:00
Chris Russell
419359b9a7
SystemParamBuilder - Enable type inference of closure parameter when building dynamic systems (#14820)
# Objective

When building a system from `SystemParamBuilder`s and defining the
system as a closure, the compiler should be able to infer the parameter
types from the builder types.

## Solution

Create methods for each arity that take an argument that implements both
`SystemParamFunction` as well as `FnMut(SystemParamItem<P>,...)`. The
explicit `FnMut` constraint will allow the compiler to infer the
necessary higher-ranked lifetimes along with the parameter types.

I wanted to show that this was possible, but I can't tell whether it's
worth the complexity. It requires a separate method for each arity,
which pollutes the docs a bit:
![SystemState build_system
docs](https://github.com/user-attachments/assets/5069b749-7ec7-47e3-a5e4-1a4c78129f78)

## Example

```rust
let system = (LocalBuilder(0u64), ParamBuilder::local::<u64>())
    .build_state(&mut world)
    .build_system(|a, b| *a + *b + 1);
```
2024-08-28 01:37:52 +00:00
Periwink
eaa805102d
add docs explaining the two accesses of a System meta (#14580)
# Objective

When reading the ECS code it is sometimes confusing to understand why we
have 2 accesses, one of ComponentId and one of ArchetypeComponentId


## Solution

Make the usage of these 2 accesses more explicit

---------

Co-authored-by: Pascal Hertleif <killercup@gmail.com>
2024-08-19 21:32:45 +00:00
Chris Russell
d4ec80d5d2
Support more kinds of system params in buildable systems. (#14050)
# Objective

Support more kinds of system params in buildable systems, such as a
`ParamSet` or `Vec` containing buildable params or tuples of buildable
params.

## Solution

Replace the `BuildableSystemParam` trait with `SystemParamBuilder` to
make it easier to compose builders. Provide implementations for existing
buildable params, plus tuples, `ParamSet`, and `Vec`.

## Examples

```rust
// ParamSet of tuple: 
let system = (ParamSetBuilder((
    QueryParamBuilder::new(|builder| { builder.with::<B>(); }),
    QueryParamBuilder::new(|builder| { builder.with::<C>(); }),
)),)
    .build_state(&mut world)
    .build_system(|mut params: ParamSet<(Query<&mut A>, Query<&mut A>)>| {
        params.p0().iter().count() + params.p1().iter().count()
    });
	
// ParamSet of Vec:
let system = (ParamSetBuilder(vec![
    QueryParamBuilder::new_box(|builder| { builder.with::<B>(); }),
    QueryParamBuilder::new_box(|builder| { builder.with::<C>(); }),
]),)
    .build_state(&mut world)
    .build_system(|mut params: ParamSet<Vec<Query<&mut A>>>| {
        let mut count = 0;
        params.for_each(|mut query| count += query.iter_mut().count());
        count
    });
```

## Migration Guide

The API for `SystemBuilder` has changed. Instead of constructing a
builder with a world and then adding params, you first create a tuple of
param builders and then supply the world.

```rust
// Before
let system = SystemBuilder::<()>::new(&mut world)
    .local::<u64>()
    .builder::<Local<u64>>(|x| *x = 10)
    .builder::<Query<&A>>(|builder| { builder.with::<B>(); })
    .build(system);

// After
let system = (
    ParamBuilder,
    LocalBuilder(10),
    QueryParamBuilder::new(|builder| { builder.with::<B>(); }),
)
    .build_state(&mut world)
    .build_system(system);
```

## Possible Future Work

Here are a few possible follow-up changes. I coded them up to prove that
this API can support them, but they aren't necessary for this PR.

* chescock/bevy#1
* chescock/bevy#2
* chescock/bevy#3
2024-08-12 15:45:35 +00:00
Lars Frost
dcbd30200e
Make names of closure systems changable (#14369)
# Objective

When using tracing or
[`bevy_mod_debugdump`](https://github.com/jakobhellermann/bevy_mod_debugdump),
the names of function systems produced by closures are either ambiguous
(like `game::mainapp::{closure}` when tracing) or too long
(`bevy_mod_debugdump` includes full type signature if no name given),
which makes debugging with tracing difficult.

## Solution
Add a function `with_name` to rename a system. The proposed API can be
used in the following way:
```rust
app
    .add_systems(Startup, IntoSystem::into_system(|name: SystemName| {
        println!("System name: {}", name.name().to_owned());
    }).with_name("print_test_system"));
```

## Testing
- There is a test in
`bevy_ecs::system:system_name::test_closure_system_name_regular_param`
2024-07-18 18:07:47 +00:00
James O'Brien
eb3c81374a
Generalised ECS reactivity with Observers (#10839)
# Objective

- Provide an expressive way to register dynamic behavior in response to
ECS changes that is consistent with existing bevy types and traits as to
provide a smooth user experience.
- Provide a mechanism for immediate changes in response to events during
command application in order to facilitate improved query caching on the
path to relations.

## Solution

- A new fundamental ECS construct, the `Observer`; inspired by flec's
observers but adapted to better fit bevy's access patterns and rust's
type system.

---

## Examples
There are 3 main ways to register observers. The first is a "component
observer" that looks like this:
```rust
world.observe(|trigger: Trigger<OnAdd, Transform>, query: Query<&Transform>| {
    let transform = query.get(trigger.entity()).unwrap();
});
```
The above code will spawn a new entity representing the observer that
will run it's callback whenever the `Transform` component is added to an
entity. This is a system-like function that supports dependency
injection for all the standard bevy types: `Query`, `Res`, `Commands`
etc. It also has a `Trigger` parameter that provides information about
the trigger such as the target entity, and the event being triggered.
Importantly these systems run during command application which is key
for their future use to keep ECS internals up to date. There are similar
events for `OnInsert` and `OnRemove`, and this will be expanded with
things such as `ArchetypeCreated`, `TableEmpty` etc. in follow up PRs.

Another way to register an observer is an "entity observer" that looks
like this:
```rust
world.entity_mut(entity).observe(|trigger: Trigger<Resize>| {
    // ...
});
```
Entity observers run whenever an event of their type is triggered
targeting that specific entity. This type of observer will de-spawn
itself if the entity (or entities) it is observing is ever de-spawned so
as to not leave dangling observers.

Entity observers can also be spawned from deferred contexts such as
other observers, systems, or hooks using commands:
```rust
commands.entity(entity).observe(|trigger: Trigger<Resize>| {
    // ...
});
```

Observers are not limited to in built event types, they can be used with
any type that implements `Event` (which has been extended to implement
Component). This means events can also carry data:

```rust
#[derive(Event)]
struct Resize { x: u32, y: u32 }

commands.entity(entity).observe(|trigger: Trigger<Resize>, query: Query<&mut Size>| {
    let event = trigger.event();
    // ...
});

// Will trigger the observer when commands are applied.
commands.trigger_targets(Resize { x: 10, y: 10 }, entity);
```

You can also trigger events that target more than one entity at a time:

```rust
commands.trigger_targets(Resize { x: 10, y: 10 }, [e1, e2]);
```

Additionally, Observers don't _need_ entity targets:

```rust
app.observe(|trigger: Trigger<Quit>| {
})

commands.trigger(Quit);
```

In these cases, `trigger.entity()` will be a placeholder.

Observers are actually just normal entities with an `ObserverState` and
`Observer` component! The `observe()` functions above are just shorthand
for:

```rust
world.spawn(Observer::new(|trigger: Trigger<Resize>| {});
```

This will spawn the `Observer` system and use an `on_add` hook to add
the `ObserverState` component.

Dynamic components and trigger types are also fully supported allowing
for runtime defined trigger types.

## Possible Follow-ups
1. Deprecate `RemovedComponents`, observers should fulfill all use cases
while being more flexible and performant.
2. Queries as entities: Swap queries to entities and begin using
observers listening to archetype creation triggers to keep their caches
in sync, this allows unification of `ObserverState` and `QueryState` as
well as unlocking several API improvements for `Query` and the
management of `QueryState`.
3. Trigger bubbling: For some UI use cases in particular users are
likely to want some form of bubbling for entity observers, this is
trivial to implement naively but ideally this includes an acceleration
structure to cache hierarchy traversals.
4. All kinds of other in-built trigger types.
5. Optimization; in order to not bloat the complexity of the PR I have
kept the implementation straightforward, there are several areas where
performance can be improved. The focus for this PR is to get the
behavior implemented and not incur a performance cost for users who
don't use observers.

I am leaving each of these to follow up PR's in order to keep each of
them reviewable as this already includes significant changes.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-06-15 01:33:26 +00:00
Alice Cecile
ec7b3490f6
Add on_unimplemented Diagnostics to Most Public Traits (#13347) (#13662)
# Objective

- #13414 did not have the intended effect.
- #13404 is still blocked

## Solution

- Re-adds #13347.

Co-authored-by: Zachary Harrold <zac@harrold.com.au>
Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
2024-06-04 00:31:34 +00:00
James O'Brien
182fe3292e
Implement a SystemBuilder for building SystemParams (#13123)
# Objective

- Implement a general purpose mechanism for building `SystemParam`.
- Unblock the usage of dynamic queries in regular systems.

## Solution

- Implement a `SystemBuilder` type.

## Examples
Here are some simple test cases for the builder:
```rust
fn local_system(local: Local<u64>) -> u64 {
    *local
}

fn query_system(query: Query<()>) -> usize {
    query.iter().count()
}

fn multi_param_system(a: Local<u64>, b: Local<u64>) -> u64 {
    *a + *b + 1
}

#[test]
fn local_builder() {
    let mut world = World::new();

    let system = SystemBuilder::<()>::new(&mut world)
        .builder::<Local<u64>>(|x| *x = 10)
        .build(local_system);

    let result = world.run_system_once(system);
    assert_eq!(result, 10);
}

#[test]
fn query_builder() {
    let mut world = World::new();

    world.spawn(A);
    world.spawn_empty();

    let system = SystemBuilder::<()>::new(&mut world)
        .builder::<Query<()>>(|query| {
            query.with::<A>();
        })
        .build(query_system);

    let result = world.run_system_once(system);
    assert_eq!(result, 1);
}

#[test]
fn multi_param_builder() {
    let mut world = World::new();

    world.spawn(A);
    world.spawn_empty();

    let system = SystemBuilder::<()>::new(&mut world)
        .param::<Local<u64>>()
        .param::<Local<u64>>()
        .build(multi_param_system);

    let result = world.run_system_once(system);
    assert_eq!(result, 1);
}
```
This will be expanded as this PR is iterated.
2024-05-22 00:58:37 +00:00
Alice Cecile
ee6dfd35c9
Revert "Add on_unimplemented Diagnostics to Most Public Traits" (#13413)
# Objective

- Rust 1.78 breaks all Android support, see
https://github.com/bevyengine/bevy/issues/13331
- We should not bump the MSRV to 1.78 until that's resolved in #13366.

## Solution

- Temporarily revert https://github.com/bevyengine/bevy/pull/13347

Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
2024-05-17 17:00:43 +00:00
Zachary Harrold
11f0a2dcde
Add on_unimplemented Diagnostics to Most Public Traits (#13347)
# Objective

- Fixes #12377

## Solution

Added simple `#[diagnostic::on_unimplemented(...)]` attributes to some
critical public traits providing a more approachable initial error
message. Where appropriate, a `note` is added indicating that a `derive`
macro is available.

## Examples

<details>
<summary>Examples hidden for brevity</summary>

Below is a collection of examples showing the new error messages
produced by this change. In general, messages will start with a more
Bevy-centric error message (e.g., _`MyComponent` is not a `Component`_),
and a note directing the user to an available derive macro where
appropriate.

### Missing `#[derive(Resource)]`

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

struct MyResource;

fn main() {
    App::new()
        .insert_resource(MyResource)
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `MyResource` is not a `Resource`
   --> examples/app/empty.rs:7:26
    |
7   |         .insert_resource(MyResource)
    |          --------------- ^^^^^^^^^^ invalid `Resource`
    |          |
    |          required by a bound introduced by this call
    |
    = help: the trait `Resource` is not implemented for `MyResource`       
    = note: consider annotating `MyResource` with `#[derive(Resource)]`    
    = help: the following other types implement trait `Resource`:
              AccessibilityRequested
              ManageAccessibilityUpdates
              bevy::bevy_a11y::Focus
              DiagnosticsStore
              FrameCount
              bevy::prelude::State<S>
              SystemInfo
              bevy::prelude::Axis<T>
            and 141 others
note: required by a bound in `bevy::prelude::App::insert_resource`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:419:31
    |
419 |     pub fn insert_resource<R: Resource>(&mut self, resource: R) -> &mut Self {
    |                               ^^^^^^^^ required by this bound in `App::insert_resource`
```

</details>

### Putting A `QueryData` in a `QueryFilter` Slot

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

#[derive(Component)]
struct A;

#[derive(Component)]
struct B;

fn my_system(_query: Query<&A, &B>) {}

fn main() {
    App::new()
        .add_systems(Update, my_system)
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `&B` is not a valid `Query` filter
   --> examples/app/empty.rs:9:22
    |
9   | fn my_system(_query: Query<&A, &B>) {}
    |                      ^^^^^^^^^^^^^ invalid `Query` filter
    |
    = help: the trait `QueryFilter` is not implemented for `&B`
    = help: the following other types implement trait `QueryFilter`:
              With<T>
              Without<T>
              bevy::prelude::Or<()>
              bevy::prelude::Or<(F0,)>
              bevy::prelude::Or<(F0, F1)>
              bevy::prelude::Or<(F0, F1, F2)>
              bevy::prelude::Or<(F0, F1, F2, F3)>
              bevy::prelude::Or<(F0, F1, F2, F3, F4)>
            and 28 others
note: required by a bound in `bevy::prelude::Query`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\query.rs:349:51
    |
349 | pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> {
    |                                                   ^^^^^^^^^^^ required by this bound in `Query`
```

</details>

### Missing `#[derive(Component)]`

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

struct A;

fn my_system(mut commands: Commands) {
    commands.spawn(A);
}

fn main() {
    App::new()
        .add_systems(Startup, my_system)
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `A` is not a `Bundle`
   --> examples/app/empty.rs:6:20
    |
6   |     commands.spawn(A);
    |              ----- ^ invalid `Bundle`
    |              |
    |              required by a bound introduced by this call
    |
    = help: the trait `bevy::prelude::Component` is not implemented for `A`, which is required by `A: Bundle`
    = note: consider annotating `A` with `#[derive(Component)]` or `#[derive(Bundle)]`
    = help: the following other types implement trait `Bundle`:
              TransformBundle
              SceneBundle
              DynamicSceneBundle
              AudioSourceBundle<Source>
              SpriteBundle
              SpriteSheetBundle
              Text2dBundle
              MaterialMesh2dBundle<M>
            and 34 others
    = note: required for `A` to implement `Bundle`
note: required by a bound in `bevy::prelude::Commands::<'w, 's>::spawn`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\commands\mod.rs:243:21
    |
243 |     pub fn spawn<T: Bundle>(&mut self, bundle: T) -> EntityCommands {
    |                     ^^^^^^ required by this bound in `Commands::<'w, 's>::spawn`
```

</details>

### Missing `#[derive(Asset)]`

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

struct A;

fn main() {
    App::new()
        .init_asset::<A>()
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `A` is not an `Asset`
   --> examples/app/empty.rs:7:23
    |
7   |         .init_asset::<A>()
    |          ----------   ^ invalid `Asset`
    |          |
    |          required by a bound introduced by this call
    |
    = help: the trait `Asset` is not implemented for `A`
    = note: consider annotating `A` with `#[derive(Asset)]`
    = help: the following other types implement trait `Asset`:
              Font
              AnimationGraph
              DynamicScene
              Scene
              AudioSource
              Pitch
              bevy::bevy_gltf::Gltf
              GltfNode
            and 17 others
note: required by a bound in `init_asset`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_asset\src\lib.rs:307:22
    |
307 |     fn init_asset<A: Asset>(&mut self) -> &mut Self;
    |                      ^^^^^ required by this bound in `AssetApp::init_asset`
```

</details>

### Mismatched Input and Output on System Piping

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

fn producer() -> u32 {
    123
}

fn consumer(_: In<u16>) {}

fn main() {
    App::new()
        .add_systems(Update, producer.pipe(consumer))
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `fn(bevy::prelude::In<u16>) {consumer}` is not a valid system with input `u32` and output `_`
   --> examples/app/empty.rs:11:44
    |
11  |         .add_systems(Update, producer.pipe(consumer))
    |                                       ---- ^^^^^^^^ invalid system
    |                                       |
    |                                       required by a bound introduced by this call
    |
    = help: the trait `bevy::prelude::IntoSystem<u32, _, _>` is not implemented for fn item `fn(bevy::prelude::In<u16>) {consumer}`
    = note: expecting a system which consumes `u32` and produces `_`
note: required by a bound in `pipe`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\mod.rs:168:12
    |
166 |     fn pipe<B, Final, MarkerB>(self, system: B) -> PipeSystem<Self::System, B::System>
    |        ---- required by a bound in this associated function
167 |     where
168 |         B: IntoSystem<Out, Final, MarkerB>,
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `IntoSystem::pipe`
```

</details>

### Missing Reflection

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

#[derive(Component)]
struct MyComponent;

fn main() {
    App::new()
        .register_type::<MyComponent>()
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `MyComponent` does not provide type registration information
   --> examples/app/empty.rs:8:26
    |
8   |         .register_type::<MyComponent>()
    |          -------------   ^^^^^^^^^^^ the trait `GetTypeRegistration` is not implemented for `MyComponent`
    |          |
    |          required by a bound introduced by this call
    |
    = note: consider annotating `MyComponent` with `#[derive(Reflect)]`
    = help: the following other types implement trait `GetTypeRegistration`:
              bool
              char
              isize
              i8
              i16
              i32
              i64
              i128
            and 443 others
note: required by a bound in `bevy::prelude::App::register_type`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:619:29
    |
619 |     pub fn register_type<T: bevy_reflect::GetTypeRegistration>(&mut self) -> &mut Self {
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::register_type`
```

</details>

### Missing `#[derive(States)]` Implementation

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

#[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Hash)]
enum AppState {
    #[default]
    Menu,
    InGame {
        paused: bool,
        turbo: bool,
    },
}

fn main() {
    App::new()
        .init_state::<AppState>()
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: the trait bound `AppState: FreelyMutableState` is not satisfied
   --> examples/app/empty.rs:15:23
    |
15  |         .init_state::<AppState>()
    |          ----------   ^^^^^^^^ the trait `FreelyMutableState` is not implemented for `AppState`
    |          |
    |          required by a bound introduced by this call
    |
    = note: consider annotating `AppState` with `#[derive(States)]`
note: required by a bound in `bevy::prelude::App::init_state`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:282:26
    |
282 |     pub fn init_state<S: FreelyMutableState + FromWorld>(&mut self) -> &mut Self {
    |                          ^^^^^^^^^^^^^^^^^^ required by this bound in `App::init_state`
```

</details>

### Adding a `System` with Unhandled Output

<details>
<summary>Example Code</summary>

```rust
use bevy::prelude::*;

fn producer() -> u32 {
    123
}

fn main() {
    App::new()
        .add_systems(Update, consumer)
        .run();
}
```

</details>

<details>
<summary>Error Generated</summary>

```error
error[E0277]: `fn() -> u32 {producer}` does not describe a valid system configuration
   --> examples/app/empty.rs:9:30
    |
9   |         .add_systems(Update, producer)
    |          -----------         ^^^^^^^^ invalid system configuration
    |          |
    |          required by a bound introduced by this call
    |
    = help: the trait `IntoSystem<(), (), _>` is not implemented for fn item `fn() -> u32 {producer}`, which is required by `fn() -> u32 {producer}: IntoSystemConfigs<_>`
    = help: the following other types implement trait `IntoSystemConfigs<Marker>`:
              <Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)> as IntoSystemConfigs<()>>
              <NodeConfigs<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)>> as IntoSystemConfigs<()>>
              <(S0,) as IntoSystemConfigs<(SystemConfigTupleMarker, P0)>>
              <(S0, S1) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1)>>
              <(S0, S1, S2) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2)>>
              <(S0, S1, S2, S3) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3)>>
              <(S0, S1, S2, S3, S4) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4)>>
              <(S0, S1, S2, S3, S4, S5) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4, P5)>>
            and 14 others
    = note: required for `fn() -> u32 {producer}` to implement `IntoSystemConfigs<_>`
note: required by a bound in `bevy::prelude::App::add_systems`
   --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:342:23
    |
339 |     pub fn add_systems<M>(
    |            ----------- required by a bound in this associated function
...
342 |         systems: impl IntoSystemConfigs<M>,
    |                       ^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::add_systems`
```

</details>
</details>

## Testing

CI passed locally.

## Migration Guide

Upgrade to version 1.78 (or higher) of Rust.

## Future Work

- Currently, hints are not supported in this diagnostic. Ideally,
suggestions like _"consider using ..."_ would be in a hint rather than a
note, but that is the best option for now.
- System chaining and other `all_tuples!(...)`-based traits have bad
error messages due to the slightly different error message format.

---------

Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
2024-05-17 00:49:05 +00:00
James Liu
54456b7ea6
Make SystemParam::new_archetype and QueryState::new_archetype unsafe functions (#13044)
# Objective
Fix #2128. Both `Query::new_archetype` and `SystemParam::new_archetype`
do not check if the `Archetype` comes from the same World the state is
initialized from. This could result in unsoundness via invalid accesses
if called incorrectly.

## Solution
Make them `unsafe` functions and lift the invariant to the caller. This
also caught one instance of us not validating the World in
`SystemState::update_archetypes_unsafe_world_cell`'s implementation.

---

## Changelog
Changed: `QueryState::new_archetype` is now an unsafe function.
Changed: `SystemParam::new_archetype` is now an unsafe function.

## Migration Guide
`QueryState::new_archetype` and `SystemParam::new_archetype` are now an
unsafe functions that must be sure that the provided `Archetype` is from
the same `World` that the state was initialized from. Callers may need
to add additional assertions or propagate the safety invariant upwards
through the callstack to ensure safety.
2024-04-21 02:49:42 +00:00
Tristan Guichaoua
33c7a2251e
bevy_ecs address trivial cases of unsafe_op_in_unsafe_fn (#11861)
# Objective

- Part of #11590
- Fix `unsafe_op_in_unsafe_fn` for trivial cases in bevy_ecs

## Solution

Fix `unsafe_op_in_unsafe_fn` in bevy_ecs for trivial cases, i.e., add an
`unsafe` block when the safety comment already exists or add a comment
like "The invariants are uphold by the caller".

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2024-02-22 00:04:38 +00:00
Jakob Hellermann
a491bce680
Fix SystemTypeSet::system_type being out of sync with System::type_id (#12030)
## Objective

Always have `some_system.into_system().type_id() ==
some_system.into_system_set().system_type().unwrap()`.

System sets have a `fn system_type() -> Option<TypeId>` that is
implemented by `SystemTypeSet` to returning the TypeId of the system's
function type. This was implemented in
https://github.com/bevyengine/bevy/pull/7715 and is used in
`bevy_mod_debugdump` to handle `.after(function)` constraints.

Back then, `System::type_id` always also returned the type id of the
function item, not of `FunctionSystem<M, F>`.

https://github.com/bevyengine/bevy/pull/11728 changes the behaviour of
`System::type_id` so that it returns the id of the
`FunctionSystem`/`ExclusiveFunctionSystem` wrapper, but it did not
change `SystemTypeSet::system_type`, so doing the lookup breaks in
`bevy_mod_debugdump`.

## Solution

Change `IntoSystemSet` for functions to return a
`SystemTypeSet<FunctionSystem>` /
`SystemTypeSet<ExclusiveFunctionSystem>` instead of `SystemTypeSet<F>`.
2024-02-21 23:40:45 +00:00
Zachary Harrold
950bd2284d
System::type_id Consistency (#11728)
# Objective

- Fixes #11679

## Solution

- Added `IntoSystem::system_type_id` which returns the equivalent of
`system.into_system().type_id()` without construction. This allows for
getting the `TypeId` of functions (a function is an unnamed type and
therefore you cannot call `TypeId::of::<apply_deferred::System>()`)
- Added default implementation of `System::type_id` to ensure
consistency between implementations. Some returned `Self`, while others
were returning an inner value instead. This ensures consistency with
`IntoSystem::system_type_id`.

## Migration Guide

If you use `System::type_id()` on function systems (exclusive or not),
ensure you are comparing its value to other `System::type_id()` calls,
or `IntoSystem::system_type_id()`.

This code wont require any changes, because `IntoSystem`'s are directly
compared to each other.

```rust
fn test_system() {}

let type_id = test_system.type_id();

// ...

// No change required
assert_eq!(test_system.type_id(), type_id);
```

Likewise, this code wont, because `System`'s are directly compared.

```rust
fn test_system() {}

let type_id = IntoSystem::into_system(test_system).type_id();

// ...

// No change required
assert_eq!(IntoSystem::into_system(test_system).type_id(), type_id);
```

The below _does_ require a change, since you're comparing a `System`
type to a `IntoSystem` type.

```rust
fn test_system() {}

// Before
assert_eq!(test_system.type_id(), IntoSystem::into_system(test_system).type_id());

// After
assert_eq!(test_system.system_type_id(), IntoSystem::into_system(test_system).type_id());
```
2024-02-06 14:43:33 +00:00
Doonv
189ceaf0d3
Replace or document ignored doctests (#11040)
# Objective

There are a lot of doctests that are `ignore`d for no documented reason.
And that should be fixed.

## Solution

I searched the bevy repo with the regex ` ```[a-z,]*ignore ` in order to
find all `ignore`d doctests. For each one of the `ignore`d doctests, I
did the following steps:
1. Attempt to remove the `ignored` attribute while still passing the
test. I did this by adding hidden dummy structs and imports.
2. If step 1 doesn't work, attempt to replace the `ignored` attribute
with the `no_run` attribute while still passing the test.
3. If step 2 doesn't work, keep the `ignored` attribute but add
documentation for why the `ignored` attribute was added.

---------

Co-authored-by: François <mockersf@gmail.com>
2024-01-01 16:50:56 +00:00
Tygyh
63d17e8494
Simplify equality assertions (#10988)
# Objective

- Shorten assertions.

## Solution

- Replace '==' assertions with 'assert_eq()' and '!=' assertions with
'assert_ne()' .
2023-12-16 23:58:41 +00:00
Mike
6b84ba97a3
Auto insert sync points (#9822)
# Objective

- Users are often confused when their command effects are not visible in
the next system. This PR auto inserts sync points if there are deferred
buffers on a system and there are dependents on that system (systems
with after relationships).
- Manual sync points can lead to users adding more than needed and it's
hard for the user to have a global understanding of their system graph
to know which sync points can be merged. However we can easily calculate
which sync points can be merged automatically.

## Solution

1. Add new edge types to allow opting out of new behavior
2. Insert an sync point for each edge whose initial node has deferred
system params.
3. Reuse nodes if they're at the number of sync points away.

* add opt outs for specific edges with `after_ignore_deferred`,
`before_ignore_deferred` and `chain_ignore_deferred`. The
`auto_insert_apply_deferred` boolean on `ScheduleBuildSettings` can be
set to false to opt out for the whole schedule.

## Perf
This has a small negative effect on schedule build times.
```text
group                                           auto-sync                              main-for-auto-sync
-----                                           -----------                            ------------------
build_schedule/1000_schedule                    1.06       2.8±0.15s        ? ?/sec    1.00       2.7±0.06s        ? ?/sec
build_schedule/1000_schedule_noconstraints      1.01     26.2±0.88ms        ? ?/sec    1.00     25.8±0.36ms        ? ?/sec
build_schedule/100_schedule                     1.02     13.1±0.33ms        ? ?/sec    1.00     12.9±0.28ms        ? ?/sec
build_schedule/100_schedule_noconstraints       1.08   505.3±29.30µs        ? ?/sec    1.00   469.4±12.48µs        ? ?/sec
build_schedule/500_schedule                     1.00    485.5±6.29ms        ? ?/sec    1.00    485.5±9.80ms        ? ?/sec
build_schedule/500_schedule_noconstraints       1.00      6.8±0.10ms        ? ?/sec    1.02      6.9±0.16ms        ? ?/sec
```
---

## Changelog

- Auto insert sync points and added `after_ignore_deferred`,
`before_ignore_deferred`, `chain_no_deferred` and
`auto_insert_apply_deferred` APIs to opt out of this behavior

## Migration Guide

- `apply_deferred` points are added automatically when there is ordering
relationship with a system that has deferred parameters like `Commands`.
If you want to opt out of this you can switch from `after`, `before`,
and `chain` to the corresponding `ignore_deferred` API,
`after_ignore_deferred`, `before_ignore_deferred` or
`chain_ignore_deferred` for your system/set ordering.
- You can also set `ScheduleBuildSettings::auto_insert_sync_points` to
`false` if you want to do it for the whole schedule. Note that in this
mode you can still add `apply_deferred` points manually.
- For most manual insertions of `apply_deferred` you should remove them
as they cannot be merged with the automatically inserted points and
might reduce parallelizability of the system graph.

## TODO
- [x] remove any apply_deferred used in the engine
- [x] ~~decide if we should deprecate manually using apply_deferred.~~
We'll still allow inserting manual sync points for now for whatever edge
cases users might have.
- [x] Update migration guide
- [x] rerun schedule build benchmarks

---------

Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
2023-12-14 16:34:01 +00:00
Tygyh
b2661ea73d
Reorder impl to be the same as the trait (#10964)
# Objective

- Make the implementation order consistent between all sources to fit
the order in the trait.

## Solution

- Change the implementation order.
2023-12-13 21:19:49 +00:00
tygyh
fd308571c4
Remove unnecessary path prefixes (#10749)
# Objective

- Shorten paths by removing unnecessary prefixes

## Solution

- Remove the prefixes from many paths which do not need them. Finding
the paths was done automatically using built-in refactoring tools in
Jetbrains RustRover.
2023-11-28 23:43:40 +00:00
Mike
11b1b3a24f
delete methods deprecated in 0.12 (#10693)
## Changelog

- delete methods deprecated in 0.12
2023-11-24 16:15:47 +00:00
Edgar Geier
a830530be4
Replace all labels with interned labels (#7762)
# Objective

First of all, this PR took heavy inspiration from #7760 and #5715. It
intends to also fix #5569, but with a slightly different approach.


This also fixes #9335 by reexporting `DynEq`.

## Solution

The advantage of this API is that we can intern a value without
allocating for zero-sized-types and for enum variants that have no
fields. This PR does this automatically in the `SystemSet` and
`ScheduleLabel` derive macros for unit structs and fieldless enum
variants. So this should cover many internal and external use cases of
`SystemSet` and `ScheduleLabel`. In these optimal use cases, no memory
will be allocated.

- The interning returns a `Interned<dyn SystemSet>`, which is just a
wrapper around a `&'static dyn SystemSet`.
- `Hash` and `Eq` are implemented in terms of the pointer value of the
reference, similar to my first approach of anonymous system sets in
#7676.
- Therefore, `Interned<T>` does not implement `Borrow<T>`, only `Deref`.
- The debug output of `Interned<T>` is the same as the interned value.

Edit: 
- `AppLabel` is now also interned and the old
`derive_label`/`define_label` macros were replaced with the new
interning implementation.
- Anonymous set ids are reused for different `Schedule`s, reducing the
amount of leaked memory.

### Pros
- `InternedSystemSet` and `InternedScheduleLabel` behave very similar to
the current `BoxedSystemSet` and `BoxedScheduleLabel`, but can be copied
without an allocation.
- Many use cases don't allocate at all.
- Very fast lookups and comparisons when using `InternedSystemSet` and
`InternedScheduleLabel`.
- The `intern` module might be usable in other areas.
- `Interned{ScheduleLabel, SystemSet, AppLabel}` does implement
`{ScheduleLabel, SystemSet, AppLabel}`, increasing ergonomics.

### Cons
- Implementors of `SystemSet` and `ScheduleLabel` still need to
implement `Hash` and `Eq` (and `Clone`) for it to work.

## Changelog

### Added

- Added `intern` module to `bevy_utils`.
- Added reexports of `DynEq` to `bevy_ecs` and `bevy_app`.

### Changed

- Replaced `BoxedSystemSet` and `BoxedScheduleLabel` with
`InternedSystemSet` and `InternedScheduleLabel`.
- Replaced `impl AsRef<dyn ScheduleLabel>` with `impl ScheduleLabel`.
- Replaced `AppLabelId` with `InternedAppLabel`.
- Changed `AppLabel` to use `Debug` for error messages.
- Changed `AppLabel` to use interning.
- Changed `define_label`/`derive_label` to use interning. 
- Replaced `define_boxed_label`/`derive_boxed_label` with
`define_label`/`derive_label`.
- Changed anonymous set ids to be only unique inside a schedule, not
globally.
- Made interned label types implement their label trait. 

### Removed

- Removed `define_boxed_label` and `derive_boxed_label`. 

## Migration guide

- Replace `BoxedScheduleLabel` and `Box<dyn ScheduleLabel>` with
`InternedScheduleLabel` or `Interned<dyn ScheduleLabel>`.
- Replace `BoxedSystemSet` and `Box<dyn SystemSet>` with
`InternedSystemSet` or `Interned<dyn SystemSet>`.
- Replace `AppLabelId` with `InternedAppLabel` or `Interned<dyn
AppLabel>`.
- Types manually implementing `ScheduleLabel`, `AppLabel` or `SystemSet`
need to implement:
  - `dyn_hash` directly instead of implementing `DynHash`
  - `as_dyn_eq`
- Pass labels to `World::try_schedule_scope`, `World::schedule_scope`,
`World::try_run_schedule`. `World::run_schedule`, `Schedules::remove`,
`Schedules::remove_entry`, `Schedules::contains`, `Schedules::get` and
`Schedules::get_mut` by value instead of by reference.

---------

Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2023-10-25 21:39:23 +00:00
Nicola Papale
1bf271d56e
Add a public API to ArchetypeGeneration/Id (#9825)
Objective
---------

- Since #6742, It is not possible to build an `ArchetypeId` from a
`ArchetypeGeneration`
- This was useful to 3rd party crate extending the base bevy ECS
capabilities, such as [`bevy_ecs_dynamic`] and now
[`bevy_mod_dynamic_query`]
- Making `ArchetypeGeneration` opaque this way made it completely
useless, and removed the ability to limit archetype updates to a subset
of archetypes.
- Making the `index` method on `ArchetypeId` private prevented the use
of bitfields and other optimized data structure to store sets of
archetype ids. (without `transmute`)

This PR is not a simple reversal of the change. It exposes a different
API, rethought to keep the private stuff private and the public stuff
less error-prone.

- Add a `StartRange<ArchetypeGeneration>` `Index` implementation to
`Archetypes`
- Instead of converting the generation into an index, then creating a
ArchetypeId from that index, and indexing `Archetypes` with it, use
directly the old `ArchetypeGeneration` to get the range of new
archetypes.

From careful benchmarking, it seems to also be a performance improvement
(~0-5%) on add_archetypes.

---

Changelog
---------

- Added `impl Index<RangeFrom<ArchetypeGeneration>> for Archetypes` this
allows you to get a slice of newly added archetypes since the last
recorded generation.
- Added `ArchetypeId::index` and `ArchetypeId::new` methods. It should
enable 3rd party crates to use the `Archetypes` API in a meaningful way.

[`bevy_ecs_dynamic`]:
https://github.com/jakobhellermann/bevy_ecs_dynamic/tree/main
[`bevy_mod_dynamic_query`]:
https://github.com/nicopap/bevy_mod_dynamic_query/

---------

Co-authored-by: vero <email@atlasdostal.com>
2023-10-02 12:54:45 +00:00
Joseph
e60249e59d
Improve codegen for world validation (#9464)
# Objective

Improve code-gen for `QueryState::validate_world` and
`SystemState::validate_world`.

## Solution

* Move panics into separate, non-inlined functions, to reduce the code
size of the outer methods.
* Mark the panicking functions with `#[cold]` to help the compiler
optimize for the happy path.
* Mark the functions with `#[track_caller]` to make debugging easier.

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2023-09-21 20:57:06 +00:00