mirror of
https://github.com/bevyengine/bevy
synced 2024-11-10 07:04:33 +00:00
add detailed errors (#2994)
# Objective - Improve error descriptions and help understand how to fix them - I noticed one today that could be expanded, it seemed like a good starting point ## Solution - Start something like https://github.com/rust-lang/rust/tree/master/compiler/rustc_error_codes/src/error_codes - Remove sentence about Rust mutability rules which is not very helpful in the error message I decided to start the error code with B for Bevy so that they're not confused with error code from rust (which starts with E) Longer term, there are a few more evolutions that can continue this: - the code samples should be compiled check, and even executed for some of them to check they have the correct error code in a panic - the error could be build on a page in the website like https://doc.rust-lang.org/error-index.html - most panic should have their own error code
This commit is contained in:
parent
a5c675f336
commit
b3cd48228b
6 changed files with 155 additions and 8 deletions
|
@ -13,7 +13,7 @@ repository = "https://github.com/bevyengine/bevy"
|
|||
|
||||
[workspace]
|
||||
exclude = ["benches"]
|
||||
members = ["crates/*", "examples/ios", "tools/ci"]
|
||||
members = ["crates/*", "examples/ios", "tools/ci", "errors"]
|
||||
|
||||
[features]
|
||||
default = [
|
||||
|
|
|
@ -185,7 +185,7 @@ fn assert_component_access_compatibility(
|
|||
.map(|component_id| world.components.get_info(component_id).unwrap().name())
|
||||
.collect::<Vec<&str>>();
|
||||
let accesses = conflicting_components.join(", ");
|
||||
panic!("Query<{}, {}> in system {} accesses component(s) {} in a way that conflicts with a previous system parameter. Allowing this would break Rust's mutability rules. Consider using `Without<T>` to create disjoint Queries or merging conflicting Queries into a `QuerySet`.",
|
||||
panic!("error[B0001]: Query<{}, {}> in system {} accesses component(s) {} in a way that conflicts with a previous system parameter. Consider using `Without<T>` to create disjoint Queries or merging conflicting Queries into a `QuerySet`.",
|
||||
query_type, filter_type, system_name, accesses);
|
||||
}
|
||||
|
||||
|
@ -287,7 +287,7 @@ unsafe impl<T: Resource> SystemParamState for ResState<T> {
|
|||
let combined_access = system_meta.component_access_set.combined_access_mut();
|
||||
if combined_access.has_write(component_id) {
|
||||
panic!(
|
||||
"Res<{}> in system {} conflicts with a previous ResMut<{0}> access. Allowing this would break Rust's mutability rules. Consider removing the duplicate access.",
|
||||
"error[B0002]: Res<{}> in system {} conflicts with a previous ResMut<{0}> access. Consider removing the duplicate access.",
|
||||
std::any::type_name::<T>(), system_meta.name);
|
||||
}
|
||||
combined_access.add_read(component_id);
|
||||
|
@ -398,11 +398,11 @@ unsafe impl<T: Resource> SystemParamState for ResMutState<T> {
|
|||
let combined_access = system_meta.component_access_set.combined_access_mut();
|
||||
if combined_access.has_write(component_id) {
|
||||
panic!(
|
||||
"ResMut<{}> in system {} conflicts with a previous ResMut<{0}> access. Allowing this would break Rust's mutability rules. Consider removing the duplicate access.",
|
||||
"error[B0002]: ResMut<{}> in system {} conflicts with a previous ResMut<{0}> access. Consider removing the duplicate access.",
|
||||
std::any::type_name::<T>(), system_meta.name);
|
||||
} else if combined_access.has_read(component_id) {
|
||||
panic!(
|
||||
"ResMut<{}> in system {} conflicts with a previous Res<{0}> access. Allowing this would break Rust's mutability rules. Consider removing the duplicate access.",
|
||||
"error[B0002]: ResMut<{}> in system {} conflicts with a previous Res<{0}> access. Consider removing the duplicate access.",
|
||||
std::any::type_name::<T>(), system_meta.name);
|
||||
}
|
||||
combined_access.add_write(component_id);
|
||||
|
@ -775,7 +775,7 @@ unsafe impl<T: 'static> SystemParamState for NonSendState<T> {
|
|||
let combined_access = system_meta.component_access_set.combined_access_mut();
|
||||
if combined_access.has_write(component_id) {
|
||||
panic!(
|
||||
"NonSend<{}> in system {} conflicts with a previous mutable resource access ({0}). Allowing this would break Rust's mutability rules. Consider removing the duplicate access.",
|
||||
"error[B0002]: NonSend<{}> in system {} conflicts with a previous mutable resource access ({0}). Consider removing the duplicate access.",
|
||||
std::any::type_name::<T>(), system_meta.name);
|
||||
}
|
||||
combined_access.add_read(component_id);
|
||||
|
@ -891,11 +891,11 @@ unsafe impl<T: 'static> SystemParamState for NonSendMutState<T> {
|
|||
let combined_access = system_meta.component_access_set.combined_access_mut();
|
||||
if combined_access.has_write(component_id) {
|
||||
panic!(
|
||||
"NonSendMut<{}> in system {} conflicts with a previous mutable resource access ({0}). Allowing this would break Rust's mutability rules. Consider removing the duplicate access.",
|
||||
"error[B0002]: NonSendMut<{}> in system {} conflicts with a previous mutable resource access ({0}). Consider removing the duplicate access.",
|
||||
std::any::type_name::<T>(), system_meta.name);
|
||||
} else if combined_access.has_read(component_id) {
|
||||
panic!(
|
||||
"NonSendMut<{}> in system {} conflicts with a previous immutable resource access ({0}). Allowing this would break Rust's mutability rules. Consider removing the duplicate access.",
|
||||
"error[B0002]: NonSendMut<{}> in system {} conflicts with a previous immutable resource access ({0}). Consider removing the duplicate access.",
|
||||
std::any::type_name::<T>(), system_meta.name);
|
||||
}
|
||||
combined_access.add_write(component_id);
|
||||
|
|
91
errors/B0001.md
Normal file
91
errors/B0001.md
Normal file
|
@ -0,0 +1,91 @@
|
|||
# B0001
|
||||
|
||||
To keep [Rust rules on references](https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#the-rules-of-references) (either one mutable reference or any number of immutable references) on a component, it is not possible to have two queries on the same component when one request mutable access to it in the same system.
|
||||
|
||||
Erroneous code example:
|
||||
|
||||
```rust,should_panic
|
||||
use bevy::prelude::*;
|
||||
|
||||
#[derive(Component)]
|
||||
struct Player;
|
||||
|
||||
#[derive(Component)]
|
||||
struct Enemy;
|
||||
|
||||
fn move_enemies_to_player(
|
||||
mut enemies: Query<&mut Transform, With<Enemy>>,
|
||||
player: Query<&Transform, With<Player>>,
|
||||
) {
|
||||
// ...
|
||||
}
|
||||
|
||||
fn main() {
|
||||
App::new()
|
||||
.add_plugins(DefaultPlugins)
|
||||
.add_system(move_enemies_to_player)
|
||||
.run();
|
||||
}
|
||||
```
|
||||
|
||||
This will panic, as it's not possible to have both a mutable and an immutable query on `Transform` at the same time.
|
||||
|
||||
You have two solutions:
|
||||
|
||||
Solution #1: use disjoint queries using [`Without`](https://docs.rs/bevy/*/bevy/ecs/query/struct.Without.html)
|
||||
|
||||
As a `Player` entity won't be an `Enemy` at the same time, those two queries will acutally never target the same entity. This can be encoded in the query filter with [`Without`](https://docs.rs/bevy/*/bevy/ecs/query/struct.Without.html):
|
||||
|
||||
```rust,no_run
|
||||
use bevy::prelude::*;
|
||||
|
||||
#[derive(Component)]
|
||||
struct Player;
|
||||
|
||||
#[derive(Component)]
|
||||
struct Enemy;
|
||||
|
||||
fn move_enemies_to_player(
|
||||
mut enemies: Query<&mut Transform, With<Enemy>>,
|
||||
player: Query<&Transform, (With<Player>, Without<Enemy>)>,
|
||||
) {
|
||||
// ...
|
||||
}
|
||||
|
||||
fn main() {
|
||||
App::new()
|
||||
.add_plugins(DefaultPlugins)
|
||||
.add_system(move_enemies_to_player)
|
||||
.run();
|
||||
}
|
||||
```
|
||||
|
||||
Solution #2: use a [`QuerySet`](https://docs.rs/bevy/*/bevy/ecs/system/struct.QuerySet.html)
|
||||
|
||||
A [`QuerySet`](https://docs.rs/bevy/*/bevy/ecs/system/struct.QuerySet.html) will let you have conflicting queries as a parameter, but you will still be responsible of not using them at the same time in your system.
|
||||
|
||||
```rust,no_run
|
||||
use bevy::prelude::*;
|
||||
|
||||
#[derive(Component)]
|
||||
struct Player;
|
||||
|
||||
#[derive(Component)]
|
||||
struct Enemy;
|
||||
|
||||
fn move_enemies_to_player(
|
||||
mut transforms: QuerySet<(
|
||||
QueryState<&mut Transform, With<Enemy>>,
|
||||
QueryState<&Transform, With<Player>>,
|
||||
)>,
|
||||
) {
|
||||
// ...
|
||||
}
|
||||
|
||||
fn main() {
|
||||
App::new()
|
||||
.add_plugins(DefaultPlugins)
|
||||
.add_system(move_enemies_to_player)
|
||||
.run();
|
||||
}
|
||||
```
|
44
errors/B0002.md
Normal file
44
errors/B0002.md
Normal file
|
@ -0,0 +1,44 @@
|
|||
# B0002
|
||||
|
||||
To keep [Rust rules on references](https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#the-rules-of-references) (either one mutable reference or any number of immutable references) on a resource, it is not possible to have more than one resource of a kind if one is mutable in the same system. This can happen between [`Res<T>`](https://docs.rs/bevy/*/bevy/ecs/system/struct.Res.html) and [`ResMut<T>`](https://docs.rs/bevy/*/bevy/ecs/system/struct.ResMut.html) for the same `T`, or between [`NonSend<T>`](https://docs.rs/bevy/*/bevy/ecs/system/struct.NonSend.html) and [`NonSendMut<T>`](https://docs.rs/bevy/*/bevy/ecs/system/struct.NonSendMut.html) for the same `T`.
|
||||
|
||||
Erroneous code example:
|
||||
|
||||
```rust,should_panic
|
||||
use bevy::prelude::*;
|
||||
|
||||
fn update_materials(
|
||||
mut material_updater: ResMut<Assets<ColorMaterial>>,
|
||||
current_materials: Res<Assets<ColorMaterial>>,
|
||||
) {
|
||||
// ...
|
||||
}
|
||||
|
||||
fn main() {
|
||||
App::new()
|
||||
.add_plugins(DefaultPlugins)
|
||||
.add_system(update_materials)
|
||||
.run();
|
||||
}
|
||||
```
|
||||
|
||||
This will panic, as it's not possible to have both a mutable and an immutable resource on `State` at the same time.
|
||||
|
||||
As a mutable resource already provide access to the current resource value, you can remove the immutable resource.
|
||||
|
||||
```rust,no_run
|
||||
use bevy::prelude::*;
|
||||
|
||||
fn update_materials(
|
||||
mut material_updater: ResMut<Assets<ColorMaterial>>,
|
||||
) {
|
||||
// ...
|
||||
}
|
||||
|
||||
fn main() {
|
||||
App::new()
|
||||
.add_plugins(DefaultPlugins)
|
||||
.add_system(update_materials)
|
||||
.run();
|
||||
}
|
||||
```
|
7
errors/Cargo.toml
Normal file
7
errors/Cargo.toml
Normal file
|
@ -0,0 +1,7 @@
|
|||
[package]
|
||||
name = "errors"
|
||||
version = "0.1.0"
|
||||
edition = "2021"
|
||||
|
||||
[dependencies]
|
||||
bevy = { path = "../" }
|
5
errors/src/lib.rs
Normal file
5
errors/src/lib.rs
Normal file
|
@ -0,0 +1,5 @@
|
|||
#[doc = include_str!("../B0001.md")]
|
||||
pub struct B0001;
|
||||
|
||||
#[doc = include_str!("../B0002.md")]
|
||||
pub struct B0002;
|
Loading…
Reference in a new issue