Add no_std support to bevy

.github/workflows/ci.yml

@@ -151,7 +151,31 @@ jobs:
       - name: Install Linux dependencies
         uses: ./.github/actions/install-linux-deps
       - name: Check Compile
-        run: cargo run -p ci -- compile-check-no-std
+        run: cargo check -p bevy --no-default-features --features default_no_std --target x86_64-unknown-none
+  check-compiles-no-std-portable-atomic:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    needs: ci
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/
+            crates/bevy_ecs_compile_fail_tests/target/
+            crates/bevy_reflect_compile_fail_tests/target/
+          key: ${{ runner.os }}-cargo-check-compiles-no-std-portable-atomic-${{ hashFiles('**/Cargo.toml') }}
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: thumbv6m-none-eabi
+      - name: Install Linux dependencies
+        uses: ./.github/actions/install-linux-deps
+      - name: Check Compile
+        run: cargo check -p bevy --no-default-features --features default_no_std --target thumbv6m-none-eabi
 
   build-wasm:
     runs-on: ubuntu-latest

Cargo.toml

@@ -120,6 +120,8 @@ unused_qualifications = "warn"
 
 [features]
 default = [
+  "std",
+  "async_executor",
   "android-game-activity",
   "android_shared_stdcxx",
   "animation",
@@ -130,6 +132,8 @@ default = [
   "bevy_gilrs",
   "bevy_gizmos",
   "bevy_gltf",
+  "bevy_input_focus",
+  "bevy_log",
   "bevy_mesh_picking_backend",
   "bevy_pbr",
   "bevy_picking",
@@ -156,6 +160,9 @@ default = [
   "x11",
 ]
 
+# Recommended defaults for no_std applications
+default_no_std = ["libm", "critical-section", "bevy_color", "bevy_state"]
+
 # Provides an implementation for picking meshes
 bevy_mesh_picking_backend = [
   "bevy_picking",
@@ -263,6 +270,12 @@ bevy_dev_tools = ["bevy_internal/bevy_dev_tools"]
 # Enable the Bevy Remote Protocol
 bevy_remote = ["bevy_internal/bevy_remote"]
 
+# Enable integration with `tracing` and `log`
+bevy_log = ["bevy_internal/bevy_log"]
+
+# Enable input focus subsystem
+bevy_input_focus = ["bevy_internal/bevy_input_focus"]
+
 # Enable passthrough loading for SPIR-V shaders (Only supported on Vulkan, shader capabilities and extensions must agree with the platform implementation)
 spirv_shader_passthrough = ["bevy_internal/spirv_shader_passthrough"]
 
@@ -488,6 +501,18 @@ custom_cursor = ["bevy_internal/custom_cursor"]
 # Experimental support for nodes that are ignored for UI layouting
 ghost_nodes = ["bevy_internal/ghost_nodes"]
 
+# Uses `async-executor` as a task execution backend.
+async_executor = ["std", "bevy_internal/async_executor"]
+
+# Allows access to the `std` crate.
+std = ["bevy_internal/std"]
+
+# `critical-section` provides the building blocks for synchronization primitives on all platforms, including `no_std`.
+critical-section = ["bevy_internal/critical-section"]
+
+# Uses the `libm` maths library instead of the one provided in `std` and `core`.
+libm = ["bevy_internal/libm"]
+
 [dependencies]
 bevy_internal = { path = "crates/bevy_internal", version = "0.16.0-dev", default-features = false }
 tracing = { version = "0.1", default-features = false, optional = true }

crates/bevy_animation/Cargo.toml

@@ -17,7 +17,6 @@ bevy_derive = { path = "../bevy_derive", version = "0.16.0-dev" }
 bevy_log = { path = "../bevy_log", version = "0.16.0-dev" }
 bevy_math = { path = "../bevy_math", version = "0.16.0-dev" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", features = [
-  "bevy",
   "petgraph",
 ] }
 bevy_render = { path = "../bevy_render", version = "0.16.0-dev" }

crates/bevy_app/Cargo.toml

@@ -9,13 +9,7 @@ license = "MIT OR Apache-2.0"
 keywords = ["bevy"]
 
 [features]
-default = [
-  "std",
-  "bevy_reflect",
-  "bevy_tasks",
-  "bevy_ecs/default",
-  "error_panic_hook",
-]
+default = ["std", "bevy_reflect", "bevy_ecs/default", "error_panic_hook"]
 
 # Functionality
 
@@ -29,9 +23,6 @@ reflect_functions = [
   "bevy_ecs/reflect_functions",
 ]
 
-## Adds support for running async background tasks
-bevy_tasks = ["dep:bevy_tasks"]
-
 # Debugging Features
 
 ## Enables `tracing` integration, allowing spans and other metrics to be reported
@@ -57,14 +48,14 @@ std = [
   "dep:ctrlc",
   "downcast-rs/std",
   "bevy_utils/std",
-  "bevy_tasks?/std",
+  "bevy_tasks/std",
   "bevy_platform_support/std",
 ]
 
 ## `critical-section` provides the building blocks for synchronization primitives
 ## on all platforms, including `no_std`.
 critical-section = [
-  "bevy_tasks?/critical-section",
+  "bevy_tasks/critical-section",
   "bevy_ecs/critical-section",
   "bevy_platform_support/critical-section",
   "bevy_reflect?/critical-section",
@@ -78,7 +69,7 @@ bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", default-featu
 bevy_utils = { path = "../bevy_utils", version = "0.16.0-dev", default-features = false, features = [
   "alloc",
 ] }
-bevy_tasks = { path = "../bevy_tasks", version = "0.16.0-dev", default-features = false, optional = true }
+bevy_tasks = { path = "../bevy_tasks", version = "0.16.0-dev", default-features = false }
 bevy_platform_support = { path = "../bevy_platform_support", version = "0.16.0-dev", default-features = false }
 
 # other

crates/bevy_app/src/app.rs

@@ -1353,7 +1353,7 @@ type RunnerFn = Box<dyn FnOnce(App) -> AppExit>;
 
 fn run_once(mut app: App) -> AppExit {
     while app.plugins_state() == PluginsState::Adding {
-        #[cfg(all(not(target_arch = "wasm32"), feature = "bevy_tasks"))]
+        #[cfg(not(target_arch = "wasm32"))]
         bevy_tasks::tick_global_task_pools_on_main_thread();
     }
     app.finish();

crates/bevy_app/src/lib.rs

@@ -30,7 +30,6 @@ mod plugin;
 mod plugin_group;
 mod schedule_runner;
 mod sub_app;
-#[cfg(feature = "bevy_tasks")]
 mod task_pool_plugin;
 #[cfg(all(any(unix, windows), feature = "std"))]
 mod terminal_ctrl_c_handler;
@@ -42,7 +41,6 @@ pub use plugin::*;
 pub use plugin_group::*;
 pub use schedule_runner::*;
 pub use sub_app::*;
-#[cfg(feature = "bevy_tasks")]
 pub use task_pool_plugin::*;
 #[cfg(all(any(unix, windows), feature = "std"))]
 pub use terminal_ctrl_c_handler::*;
@@ -60,10 +58,6 @@ pub mod prelude {
             RunFixedMainLoopSystem, SpawnScene, Startup, Update,
         },
         sub_app::SubApp,
-        Plugin, PluginGroup,
+        NonSendMarker, Plugin, PluginGroup, TaskPoolOptions, TaskPoolPlugin,
     };
-
-    #[cfg(feature = "bevy_tasks")]
-    #[doc(hidden)]
-    pub use crate::{NonSendMarker, TaskPoolOptions, TaskPoolPlugin};
 }

crates/bevy_app/src/schedule_runner.rs

@@ -77,7 +77,7 @@ impl Plugin for ScheduleRunnerPlugin {
             let plugins_state = app.plugins_state();
             if plugins_state != PluginsState::Cleaned {
                 while app.plugins_state() == PluginsState::Adding {
-                    #[cfg(all(not(target_arch = "wasm32"), feature = "bevy_tasks"))]
+                    #[cfg(not(target_arch = "wasm32"))]
                     bevy_tasks::tick_global_task_pools_on_main_thread();
                 }
                 app.finish();

crates/bevy_audio/Cargo.toml

@@ -14,9 +14,7 @@ bevy_app = { path = "../bevy_app", version = "0.16.0-dev" }
 bevy_asset = { path = "../bevy_asset", version = "0.16.0-dev" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.16.0-dev" }
 bevy_math = { path = "../bevy_math", version = "0.16.0-dev" }
-bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", features = [
-  "bevy",
-] }
+bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev" }
 bevy_transform = { path = "../bevy_transform", version = "0.16.0-dev" }
 bevy_derive = { path = "../bevy_derive", version = "0.16.0-dev" }
 

crates/bevy_diagnostic/Cargo.toml

@@ -26,7 +26,7 @@ serialize = [
 dynamic_linking = []
 
 ## Adds integration with `sysinfo`.
-sysinfo_plugin = ["sysinfo", "dep:bevy_tasks"]
+sysinfo_plugin = ["sysinfo"]
 
 # Platform Compatibility
 
@@ -40,7 +40,7 @@ std = [
   "bevy_platform_support/std",
   "bevy_time/std",
   "bevy_utils/std",
-  "bevy_tasks?/std",
+  "bevy_tasks/std",
 ]
 
 ## `critical-section` provides the building blocks for synchronization primitives
@@ -51,7 +51,7 @@ critical-section = [
   "bevy_platform_support/critical-section",
   "bevy_time/critical-section",
   "bevy_utils/critical-section",
-  "bevy_tasks?/critical-section",
+  "bevy_tasks/critical-section",
 ]
 
 [dependencies]
@@ -62,7 +62,7 @@ bevy_time = { path = "../bevy_time", version = "0.16.0-dev", default-features =
 bevy_utils = { path = "../bevy_utils", version = "0.16.0-dev", default-features = false, features = [
   "alloc",
 ] }
-bevy_tasks = { path = "../bevy_tasks", version = "0.16.0-dev", default-features = false, optional = true }
+bevy_tasks = { path = "../bevy_tasks", version = "0.16.0-dev", default-features = false }
 bevy_platform_support = { path = "../bevy_platform_support", version = "0.16.0-dev", default-features = false, features = [
   "alloc",
 ] }

crates/bevy_ecs/Cargo.toml

@@ -60,11 +60,7 @@ track_location = []
 
 ## Uses `async-executor` as a task execution backend.
 ## This backend is incompatible with `no_std` targets.
-async_executor = ["dep:bevy_tasks", "std", "bevy_tasks/async_executor"]
-
-## Uses `edge-executor` as a task execution backend.
-## Use this instead of `async-executor` if working on a `no_std` target.
-edge_executor = ["dep:bevy_tasks", "bevy_tasks/edge_executor"]
+async_executor = ["std", "bevy_tasks/async_executor"]
 
 # Platform Compatibility
 
@@ -90,7 +86,7 @@ std = [
 ## `critical-section` provides the building blocks for synchronization primitives
 ## on all platforms, including `no_std`.
 critical-section = [
-  "bevy_tasks?/critical-section",
+  "bevy_tasks/critical-section",
   "bevy_platform_support/critical-section",
   "bevy_reflect?/critical-section",
 ]
@@ -100,7 +96,7 @@ bevy_ptr = { path = "../bevy_ptr", version = "0.16.0-dev" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", features = [
   "smallvec",
 ], default-features = false, optional = true }
-bevy_tasks = { path = "../bevy_tasks", version = "0.16.0-dev", default-features = false, optional = true }
+bevy_tasks = { path = "../bevy_tasks", version = "0.16.0-dev", default-features = false }
 bevy_utils = { path = "../bevy_utils", version = "0.16.0-dev", default-features = false, features = [
   "alloc",
 ] }

crates/bevy_ecs/src/entity/unique_array.rs

@@ -13,10 +13,11 @@ use alloc::{
     boxed::Box,
     collections::{BTreeSet, BinaryHeap, LinkedList, VecDeque},
     rc::Rc,
-    sync::Arc,
     vec::Vec,
 };
 
+use bevy_platform_support::sync::Arc;
+
 use super::{unique_slice, TrustedEntityBorrow, UniqueEntityIter, UniqueEntitySlice};
 
 /// An array that contains only unique entities.
@@ -73,9 +74,9 @@ impl<T: TrustedEntityBorrow, const N: usize> UniqueEntityArray<T, N> {
     }
 
     /// Casts `self` to the inner array.
-    pub fn into_arc_inner(self: Arc<Self>) -> Arc<[T; N]> {
+    pub fn into_arc_inner(this: Arc<Self>) -> Arc<[T; N]> {
         // SAFETY: UniqueEntityArray is a transparent wrapper around [T; N].
-        unsafe { Arc::from_raw(Arc::into_raw(self).cast()) }
+        unsafe { Arc::from_raw(Arc::into_raw(this).cast()) }
     }
 
     // Constructs a `Rc<UniqueEntityArray>` from a [`Rc<[T; N]>`] unsafely.

crates/bevy_ecs/src/entity/unique_slice.rs

@@ -17,10 +17,11 @@ use alloc::{
     boxed::Box,
     collections::VecDeque,
     rc::Rc,
-    sync::Arc,
     vec::Vec,
 };
 
+use bevy_platform_support::sync::Arc;
+
 use super::{
     unique_vec, EntitySet, EntitySetIterator, FromEntitySetIterator, TrustedEntityBorrow,
     UniqueEntityArray, UniqueEntityIter, UniqueEntityVec,
@@ -86,9 +87,9 @@ impl<T: TrustedEntityBorrow> UniqueEntitySlice<T> {
     }
 
     /// Casts `self` to the inner slice.
-    pub fn into_arc_inner(self: Arc<Self>) -> Arc<[T]> {
+    pub fn into_arc_inner(this: Arc<Self>) -> Arc<[T]> {
         // SAFETY: UniqueEntitySlice is a transparent wrapper around [T].
-        unsafe { Arc::from_raw(Arc::into_raw(self) as *mut [T]) }
+        unsafe { Arc::from_raw(Arc::into_raw(this) as *mut [T]) }
     }
 
     // Constructs a `UniqueEntitySlice` from a [`Rc<[T]>`] unsafely.

crates/bevy_ecs/src/entity/unique_vec.rs

@@ -12,10 +12,11 @@ use alloc::{
     boxed::Box,
     collections::{BTreeSet, BinaryHeap, TryReserveError, VecDeque},
     rc::Rc,
-    sync::Arc,
     vec::{self, Vec},
 };
 
+use bevy_platform_support::sync::Arc;
+
 use super::{
     unique_slice, EntitySet, FromEntitySetIterator, TrustedEntityBorrow, UniqueEntityArray,
     UniqueEntityIter, UniqueEntitySlice,

crates/bevy_gltf/Cargo.toml

@@ -28,9 +28,7 @@ bevy_ecs = { path = "../bevy_ecs", version = "0.16.0-dev" }
 bevy_image = { path = "../bevy_image", version = "0.16.0-dev" }
 bevy_math = { path = "../bevy_math", version = "0.16.0-dev" }
 bevy_pbr = { path = "../bevy_pbr", version = "0.16.0-dev" }
-bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", features = [
-  "bevy",
-] }
+bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev" }
 bevy_render = { path = "../bevy_render", version = "0.16.0-dev" }
 bevy_scene = { path = "../bevy_scene", version = "0.16.0-dev", features = [
   "bevy_render",

crates/bevy_image/Cargo.toml

@@ -49,9 +49,7 @@ bevy_color = { path = "../bevy_color", version = "0.16.0-dev", features = [
   "wgpu-types",
 ] }
 bevy_math = { path = "../bevy_math", version = "0.16.0-dev" }
-bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", features = [
-  "bevy",
-], optional = true }
+bevy_reflect = { path = "../bevy_reflect", version = "0.16.0-dev", optional = true }
 bevy_utils = { path = "../bevy_utils", version = "0.16.0-dev" }
 bevy_platform_support = { path = "../bevy_platform_support", version = "0.16.0-dev", default-features = false, features = [
   "std",