Remove bevy_dynamic_plugin

It is hard to use the current dynamic plugin system. It doesn't allow
hot code swapping as several OSes don't allow unloading dylibs. It
requires bevy itself to be used as dylib and it requires all other
crates shared between the main game and the plugin to be dylibs.

In the future we may get better plugin support. Whether based on wasm,
or something else. Until then, remove the current dynamic plugin to
avoid making any promises about the current ability to use dynamic
plugins.

If anyone wants to keep using the current dynamic plugin support despite
all it's issues, they can copy the less than 100 lines of code this PR
deletes.

.github/workflows/ci.yml

@@ -242,13 +242,13 @@ jobs:
           toolchain: stable
       - name: Build bevy
         run: |
-          cargo build --no-default-features --features "bevy_dynamic_plugin,bevy_gilrs,bevy_gltf,bevy_winit,render,png,hdr,x11,bevy_ci_testing,trace,trace_chrome"
+          cargo build --no-default-features --features "bevy_gilrs,bevy_gltf,bevy_winit,render,png,hdr,x11,bevy_ci_testing,trace,trace_chrome"
       - name: Run examples
         run: |
           for example in .github/example-run/*.ron; do
             example_name=`basename $example .ron`
             echo "running $example_name - "`date`
-            time CI_TESTING_CONFIG=$example xvfb-run cargo run --example $example_name --no-default-features --features "bevy_dynamic_plugin,bevy_gilrs,bevy_gltf,bevy_winit,render,png,hdr,x11,bevy_ci_testing,trace,trace_chrome"
+            time CI_TESTING_CONFIG=$example xvfb-run cargo run --example $example_name --no-default-features --features "bevy_gilrs,bevy_gltf,bevy_winit,render,png,hdr,x11,bevy_ci_testing,trace,trace_chrome"
             sleep 10
           done
           zip traces.zip trace*.json

Cargo.toml

@@ -45,7 +45,6 @@ render = [
 # Optional bevy crates
 bevy_audio = ["bevy_internal/bevy_audio"]
 bevy_core_pipeline = ["bevy_internal/bevy_core_pipeline"]
-bevy_dynamic_plugin = ["bevy_internal/bevy_dynamic_plugin"]
 bevy_gilrs = ["bevy_internal/bevy_gilrs"]
 bevy_gltf = ["bevy_internal/bevy_gltf"]
 bevy_pbr = ["bevy_internal/bevy_pbr"]

crates/bevy_app/src/lib.rs

@@ -11,7 +11,6 @@ mod schedule_runner;
 mod ci_testing;
 
 pub use app::*;
-pub use bevy_derive::DynamicPlugin;
 pub use bevy_ecs::event::*;
 pub use plugin::*;
 pub use plugin_group::*;
@@ -20,9 +19,7 @@ pub use schedule_runner::*;
 #[allow(missing_docs)]
 pub mod prelude {
     #[doc(hidden)]
-    pub use crate::{
-        app::App, CoreStage, DynamicPlugin, Plugin, PluginGroup, StartupSchedule, StartupStage,
-    };
+    pub use crate::{app::App, CoreStage, Plugin, PluginGroup, StartupSchedule, StartupStage};
 }
 
 use bevy_ecs::schedule::StageLabel;

crates/bevy_app/src/plugin.rs

@@ -13,8 +13,3 @@ pub trait Plugin: Any + Send + Sync {
         std::any::type_name::<Self>()
     }
 }
-
-/// Type representing an unsafe function that returns a mutable pointer to a [`Plugin`].
-/// Used for dynamically loading plugins. See
-/// `bevy_dynamic_plugin/src/loader.rs#dynamically_load_plugin`
-pub type CreatePlugin = unsafe fn() -> *mut dyn Plugin;

crates/bevy_derive/src/lib.rs

@@ -1,6 +1,5 @@
 extern crate proc_macro;
 
-mod app_plugin;
 mod bevy_main;
 mod enum_variant_meta;
 mod modules;
@@ -9,12 +8,6 @@ use bevy_macro_utils::{derive_label, BevyManifest};
 use proc_macro::TokenStream;
 use quote::format_ident;
 
-/// Generates a dynamic plugin entry point function for the given `Plugin` type.  
-#[proc_macro_derive(DynamicPlugin)]
-pub fn derive_dynamic_plugin(input: TokenStream) -> TokenStream {
-    app_plugin::derive_dynamic_plugin(input)
-}
-
 #[proc_macro_attribute]
 pub fn bevy_main(attr: TokenStream, item: TokenStream) -> TokenStream {
     bevy_main::bevy_main(attr, item)

crates/bevy_internal/Cargo.toml

@@ -70,7 +70,6 @@ bevy_core_pipeline = { path = "../bevy_core_pipeline", optional = true, version
 bevy_gltf = { path = "../bevy_gltf", optional = true, version = "0.6.0" }
 bevy_pbr = { path = "../bevy_pbr", optional = true, version = "0.6.0" }
 bevy_render = { path = "../bevy_render", optional = true, version = "0.6.0" }
-bevy_dynamic_plugin = { path = "../bevy_dynamic_plugin", optional = true, version = "0.6.0" }
 bevy_sprite = { path = "../bevy_sprite", optional = true, version = "0.6.0" }
 bevy_text = { path = "../bevy_text", optional = true, version = "0.6.0" }
 bevy_ui = { path = "../bevy_ui", optional = true, version = "0.6.0" }

crates/bevy_internal/src/lib.rs

@@ -140,11 +140,5 @@ pub mod winit {
     pub use bevy_winit::*;
 }
 
-#[cfg(feature = "bevy_dynamic_plugin")]
-pub mod dynamic_plugin {
-    //! Dynamic linking of plugins
-    pub use bevy_dynamic_plugin::*;
-}
-
 #[cfg(target_os = "android")]
 pub use ndk_glue;

crates/bevy_internal/src/prelude.rs

@@ -35,10 +35,6 @@ pub use crate::text::prelude::*;
 #[cfg(feature = "bevy_ui")]
 pub use crate::ui::prelude::*;
 
-#[doc(hidden)]
-#[cfg(feature = "bevy_dynamic_plugin")]
-pub use crate::dynamic_plugin::*;
-
 #[doc(hidden)]
 #[cfg(feature = "bevy_gilrs")]
 pub use crate::gilrs::*;

tools/publish.sh

@@ -9,7 +9,6 @@ crates=(
     bevy_ecs
     bevy_app
     bevy_log
-    bevy_dynamic_plugin
     bevy_reflect/bevy_reflect_derive
     bevy_reflect
     bevy_asset