Harden proc macro path resolution and add integration tests. (#17330)

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 <[email protected]>

Author: raldone01

.gitignore

@@ -7,6 +7,7 @@ crates/**/target
 benches/**/target
 tools/**/target
 **/*.rs.bk
+rustc-ice-*.txt
 
 # DX12 wgpu backend
 dxcompiler.dll

Cargo.toml

@@ -29,6 +29,10 @@ members = [
   # Bevy's error codes. This is a crate so we can automatically check all of the code blocks.
   "errors",
 ]
+exclude = [
+  # Integration tests are not part of the workspace
+  "tests-integration",
+]
 
 [workspace.lints.clippy]
 doc_markdown = "warn"
@@ -494,6 +498,13 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 bytemuck = "1.7"
 bevy_render = { path = "crates/bevy_render", version = "0.16.0-dev", default-features = false }
+# The following explicit dependencies are needed for proc macros to work inside of examples as they are part of the bevy crate itself.
+bevy_ecs = { path = "crates/bevy_ecs", version = "0.16.0-dev", default-features = false }
+bevy_state = { path = "crates/bevy_state", version = "0.16.0-dev", default-features = false }
+bevy_asset = { path = "crates/bevy_asset", version = "0.16.0-dev", default-features = false }
+bevy_reflect = { path = "crates/bevy_reflect", version = "0.16.0-dev", default-features = false }
+bevy_image = { path = "crates/bevy_image", version = "0.16.0-dev", default-features = false }
+bevy_gizmos = { path = "crates/bevy_gizmos", version = "0.16.0-dev", default-features = false }
 # Needed to poll Task examples
 futures-lite = "2.0.1"
 async-std = "1.13"

benches/benches/bevy_ecs/change_detection.rs

@@ -267,7 +267,7 @@ fn none_changed_detection(criterion: &mut Criterion) {
     }
 }
 fn insert_if_bit_enabled<const B: u16>(entity: &mut EntityWorldMut, i: u16) {
-    if i & 1 << B != 0 {
+    if i & (1 << B) != 0 {
         entity.insert(Data::<B>(1.0));
     }
 }

benches/benches/bevy_ecs/components/archetype_updates.rs

@@ -22,7 +22,7 @@ fn setup(system_count: usize) -> (World, Schedule) {
 }
 
 fn insert_if_bit_enabled<const B: u16>(entity: &mut EntityWorldMut, i: u16) {
-    if i & 1 << B != 0 {
+    if i & (1 << B) != 0 {
         entity.insert(A::<B>(1.0));
     }
 }

benches/benches/bevy_ecs/empty_archetypes.rs

@@ -105,49 +105,49 @@ fn add_archetypes(world: &mut World, count: u16) {
         e.insert(A::<10>(1.0));
         e.insert(A::<11>(1.0));
         e.insert(A::<12>(1.0));
-        if i & 1 << 1 != 0 {
+        if i & (1 << 1) != 0 {
             e.insert(A::<13>(1.0));
         }
-        if i & 1 << 2 != 0 {
+        if i & (1 << 2) != 0 {
             e.insert(A::<14>(1.0));
         }
-        if i & 1 << 3 != 0 {
+        if i & (1 << 3) != 0 {
             e.insert(A::<15>(1.0));
         }
-        if i & 1 << 4 != 0 {
+        if i & (1 << 4) != 0 {
             e.insert(A::<16>(1.0));
         }
-        if i & 1 << 5 != 0 {
+        if i & (1 << 5) != 0 {
             e.insert(A::<18>(1.0));
         }
-        if i & 1 << 6 != 0 {
+        if i & (1 << 6) != 0 {
             e.insert(A::<19>(1.0));
         }
-        if i & 1 << 7 != 0 {
+        if i & (1 << 7) != 0 {
             e.insert(A::<20>(1.0));
         }
-        if i & 1 << 8 != 0 {
+        if i & (1 << 8) != 0 {
             e.insert(A::<21>(1.0));
         }
-        if i & 1 << 9 != 0 {
+        if i & (1 << 9) != 0 {
             e.insert(A::<22>(1.0));
         }
-        if i & 1 << 10 != 0 {
+        if i & (1 << 10) != 0 {
             e.insert(A::<23>(1.0));
         }
-        if i & 1 << 11 != 0 {
+        if i & (1 << 11) != 0 {
             e.insert(A::<24>(1.0));
         }
-        if i & 1 << 12 != 0 {
+        if i & (1 << 12) != 0 {
             e.insert(A::<25>(1.0));
         }
-        if i & 1 << 13 != 0 {
+        if i & (1 << 13) != 0 {
             e.insert(A::<26>(1.0));
         }
-        if i & 1 << 14 != 0 {
+        if i & (1 << 14) != 0 {
             e.insert(A::<27>(1.0));
         }
-        if i & 1 << 15 != 0 {
+        if i & (1 << 15) != 0 {
             e.insert(A::<28>(1.0));
         }
     }

benches/benches/bevy_ecs/iteration/par_iter_simple.rs

@@ -19,7 +19,7 @@ struct Data<const X: u16>(f32);
 pub struct Benchmark<'w>(World, QueryState<(&'w Velocity, &'w mut Position)>);
 
 fn insert_if_bit_enabled<const B: u16>(entity: &mut EntityWorldMut, i: u16) {
-    if i & 1 << B != 0 {
+    if i & (1 << B) != 0 {
         entity.insert(Data::<B>(1.0));
     }
 }

crates/bevy_app/src/app.rs

@@ -1532,7 +1532,6 @@ mod tests {
     #[test]
     fn test_derive_app_label() {
         use super::AppLabel;
-        use crate::{self as bevy_app};
 
         #[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
         struct UnitLabel;
@@ -1664,7 +1663,6 @@ mod tests {
     #[test]
     fn test_extract_sees_changes() {
         use super::AppLabel;
-        use crate::{self as bevy_app};
 
         #[derive(AppLabel, Clone, Copy, Hash, PartialEq, Eq, Debug)]
         struct MySubApp;

crates/bevy_app/src/lib.rs

@@ -20,6 +20,9 @@ extern crate std;
 
 extern crate alloc;
 
+// Required to make proc macros work in bevy itself.
+extern crate self as bevy_app;
+
 mod app;
 mod main_schedule;
 mod panic_handler;

crates/bevy_asset/src/asset_changed.rs

@@ -282,7 +282,7 @@ unsafe impl<A: AsAssetId> QueryFilter for AssetChanged<A> {
 
 #[cfg(test)]
 mod tests {
-    use crate::{self as bevy_asset, AssetEvents, AssetPlugin, Handle};
+    use crate::{AssetEvents, AssetPlugin, Handle};
     use alloc::{vec, vec::Vec};
     use core::num::NonZero;
     use std::println;

crates/bevy_asset/src/assets.rs

@@ -1,8 +1,5 @@
 use crate::asset_changed::AssetChanges;
-use crate::{
-    self as bevy_asset, Asset, AssetEvent, AssetHandleProvider, AssetId, AssetServer, Handle,
-    UntypedHandle,
-};
+use crate::{Asset, AssetEvent, AssetHandleProvider, AssetId, AssetServer, Handle, UntypedHandle};
 use alloc::{sync::Arc, vec::Vec};
 use bevy_ecs::{
     prelude::EventWriter,

crates/bevy_asset/src/folder.rs

@@ -1,6 +1,5 @@
 use alloc::vec::Vec;
 
-use crate as bevy_asset;
 use crate::{Asset, UntypedHandle};
 use bevy_reflect::TypePath;
 

crates/bevy_asset/src/lib.rs

@@ -149,6 +149,9 @@
 extern crate alloc;
 extern crate std;
 
+// Required to make proc macros work in bevy itself.
+extern crate self as bevy_asset;
+
 pub mod io;
 pub mod meta;
 pub mod processor;
@@ -627,7 +630,6 @@ pub struct AssetEvents;
 #[cfg(test)]
 mod tests {
     use crate::{
-        self as bevy_asset,
         folder::LoadedFolder,
         handle::Handle,
         io::{

crates/bevy_asset/src/meta.rs

@@ -5,8 +5,8 @@ use alloc::{
 };
 
 use crate::{
-    self as bevy_asset, loader::AssetLoader, processor::Process, Asset, AssetPath,
-    DeserializeMetaError, VisitAssetDependencies,
+    loader::AssetLoader, processor::Process, Asset, AssetPath, DeserializeMetaError,
+    VisitAssetDependencies,
 };
 use downcast_rs::{impl_downcast, Downcast};
 use ron::ser::PrettyConfig;

crates/bevy_asset/src/reflect.rs

@@ -247,7 +247,6 @@ mod tests {
     use alloc::{string::String, vec::Vec};
     use core::any::TypeId;
 
-    use crate as bevy_asset;
     use crate::{Asset, AssetApp, AssetPlugin, ReflectAsset, UntypedHandle};
     use bevy_app::App;
     use bevy_ecs::reflect::AppTypeRegistry;

crates/bevy_asset/src/server/loaders.rs

@@ -352,7 +352,7 @@ mod tests {
     use bevy_reflect::TypePath;
     use bevy_tasks::block_on;
 
-    use crate::{self as bevy_asset, Asset};
+    use crate::Asset;
 
     use super::*;
 

crates/bevy_ecs/src/bundle.rs

@@ -1710,7 +1710,6 @@ fn sorted_remove<T: Eq + Ord + Copy>(source: &mut Vec<T>, remove: &[T]) {
 
 #[cfg(test)]
 mod tests {
-    use crate as bevy_ecs;
     use crate::{component::HookContext, prelude::*, world::DeferredWorld};
     use alloc::vec;
 

crates/bevy_ecs/src/change_detection.rs

@@ -1268,7 +1268,6 @@ mod tests {
     use core::panic::Location;
 
     use crate::{
-        self as bevy_ecs,
         change_detection::{
             Mut, NonSendMut, Ref, ResMut, TicksMut, CHECK_TICK_THRESHOLD, MAX_CHANGE_AGE,
         },

crates/bevy_ecs/src/component.rs

@@ -1,7 +1,6 @@
 //! Types for declaring and storing [`Component`]s.
 
 use crate::{
-    self as bevy_ecs,
     archetype::ArchetypeFlags,
     bundle::BundleInfo,
     change_detection::MAX_CHANGE_AGE,

crates/bevy_ecs/src/entity/clone_entities.rs

@@ -816,12 +816,11 @@ impl<'w> EntityClonerBuilder<'w> {
 mod tests {
     use super::ComponentCloneCtx;
     use crate::{
-        self as bevy_ecs,
         component::{Component, ComponentCloneBehavior, ComponentDescriptor, StorageType},
         entity::{hash_map::EntityHashMap, Entity, EntityCloner},
-        hierarchy::{ChildOf, Children},
-        reflect::{AppTypeRegistry, ReflectComponent, ReflectFromWorld},
-        resource::Resource,
+        prelude::{ChildOf, Children, Resource},
+        reflect::AppTypeRegistry,
+        reflect::{ReflectComponent, ReflectFromWorld},
         system::Commands,
         world::{FromWorld, World},
     };
@@ -835,6 +834,7 @@ mod tests {
     mod reflect {
         use super::*;
         use crate::{
+            component::{Component, ComponentCloneBehavior},
             entity::EntityCloner,
             reflect::{AppTypeRegistry, ReflectComponent, ReflectFromWorld},
             system::Commands,

crates/bevy_ecs/src/entity/entity_set.rs

@@ -470,7 +470,6 @@ mod tests {
     use crate::query::{QueryState, With};
     use crate::system::Query;
     use crate::world::Mut;
-    use crate::{self as bevy_ecs};
 
     use super::UniqueEntityIter;
 

crates/bevy_ecs/src/entity/visit_entities.rs

@@ -57,7 +57,6 @@ impl VisitEntitiesMut for Entity {
 #[cfg(test)]
 mod tests {
     use crate::{
-        self as bevy_ecs,
         entity::{hash_map::EntityHashMap, MapEntities, SceneEntityMapper},
         world::World,
     };

crates/bevy_ecs/src/entity_disabling.rs

@@ -21,7 +21,6 @@
 //! [`World`]: crate::prelude::World
 //! [`Query` performance]: crate::prelude::Query#performance
 
-use crate as bevy_ecs;
 use crate::{
     component::{ComponentId, Components, StorageType},
     query::FilteredAccess,

crates/bevy_ecs/src/event/base.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 use crate::component::ComponentId;
 use crate::world::World;
 use crate::{component::Component, traversal::Traversal};

crates/bevy_ecs/src/event/collections.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 use alloc::vec::Vec;
 use bevy_ecs::{
     event::{Event, EventCursor, EventId, EventInstance},
@@ -398,7 +397,7 @@ impl<E: Event> ExactSizeIterator for SendBatchIds<E> {
 
 #[cfg(test)]
 mod tests {
-    use crate::{self as bevy_ecs, event::Events};
+    use crate::event::Events;
     use bevy_ecs_macros::Event;
 
     #[test]

crates/bevy_ecs/src/event/event_cursor.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 use bevy_ecs::event::{
     Event, EventIterator, EventIteratorWithId, EventMutIterator, EventMutIteratorWithId, Events,
 };

crates/bevy_ecs/src/event/iterators.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 #[cfg(feature = "multi_threaded")]
 use bevy_ecs::batching::BatchingStrategy;
 use bevy_ecs::event::{Event, EventCursor, EventId, EventInstance, Events};

crates/bevy_ecs/src/event/mod.rs

@@ -31,7 +31,6 @@ pub use writer::EventWriter;
 
 #[cfg(test)]
 mod tests {
-    use crate as bevy_ecs;
     use alloc::{vec, vec::Vec};
     use bevy_ecs::{event::*, system::assert_is_read_only_system};
     use bevy_ecs_macros::Event;

crates/bevy_ecs/src/event/mut_iterators.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 #[cfg(feature = "multi_threaded")]
 use bevy_ecs::batching::BatchingStrategy;
 use bevy_ecs::event::{Event, EventCursor, EventId, EventInstance, Events};

crates/bevy_ecs/src/event/mutator.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 #[cfg(feature = "multi_threaded")]
 use bevy_ecs::event::EventMutParIter;
 use bevy_ecs::{

crates/bevy_ecs/src/event/reader.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 #[cfg(feature = "multi_threaded")]
 use bevy_ecs::event::EventParIter;
 use bevy_ecs::{

crates/bevy_ecs/src/event/registry.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 use alloc::vec::Vec;
 use bevy_ecs::{
     change_detection::{DetectChangesMut, MutUntyped},

crates/bevy_ecs/src/event/update.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 use bevy_ecs::{
     change_detection::Mut,
     component::Tick,

crates/bevy_ecs/src/event/writer.rs

@@ -1,4 +1,3 @@
-use crate as bevy_ecs;
 use bevy_ecs::{
     event::{Event, EventId, Events, SendBatchIds},
     system::{ResMut, SystemParam},

crates/bevy_ecs/src/hierarchy.rs

@@ -9,7 +9,6 @@
 #[cfg(feature = "bevy_reflect")]
 use crate::reflect::{ReflectComponent, ReflectFromWorld};
 use crate::{
-    self as bevy_ecs,
     bundle::Bundle,
     component::{Component, HookContext},
     entity::Entity,

crates/bevy_ecs/src/identifier/mod.rs

@@ -201,7 +201,7 @@ mod tests {
         // and also Entity flag.
         let high = 0x7FFFFFFF;
         let low = 0xC;
-        let bits: u64 = high << u32::BITS | low;
+        let bits: u64 = (high << u32::BITS) | low;
 
         let id = Identifier::try_from_bits(bits).unwrap();
 

crates/bevy_ecs/src/lib.rs

@@ -33,6 +33,9 @@ compile_error!("bevy_ecs cannot safely compile for a 16-bit platform.");
 
 extern crate alloc;
 
+// Required to make proc macros work in bevy itself.
+extern crate self as bevy_ecs;
+
 pub mod archetype;
 pub mod batching;
 pub mod bundle;
@@ -128,7 +131,6 @@ pub mod __macro_exports {
 
 #[cfg(test)]
 mod tests {
-    use crate as bevy_ecs;
     use crate::{
         bundle::Bundle,
         change_detection::Ref,