Salvage old distributed slice code

Cargo.lock

@@ -3797,6 +3797,7 @@ dependencies = [
  "image",
  "itertools 0.10.5",
  "lazy_static",
+ "linkme",
  "log",
  "media",
  "metal",
@@ -4815,6 +4816,26 @@ version = "0.5.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
 
+[[package]]
+name = "linkme"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91ed2ee9464ff9707af8e9ad834cffa4802f072caad90639c583dd3c62e6e608"
+dependencies = [
+ "linkme-impl",
+]
+
+[[package]]
+name = "linkme-impl"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba125974b109d512fccbc6c0244e7580143e460895dfd6ea7f8bbb692fd94396"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.37",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.0.42"

crates/gpui2/Cargo.toml

@@ -22,6 +22,7 @@ sqlez = { path = "../sqlez" }
 async-task = "4.0.3"
 backtrace = { version = "0.3", optional = true }
 ctor.workspace = true
+linkme = "0.3"
 derive_more.workspace = true
 dhat = { version = "0.3", optional = true }
 env_logger = { version = "0.9", optional = true }

crates/gpui2/src/action.rs

@@ -200,3 +200,43 @@ macro_rules! actions {
         actions!($($rest)*);
     };
 }
+
+/// This type must be public so that our macros can build it in other crates.
+/// But this is an implementation detail and should not be used directly.
+#[doc(hidden)]
+pub struct ActionData {
+    pub name: &'static str,
+    pub build: ActionBuilder,
+    pub type_id: TypeId,
+}
+
+/// This type must be public so that our macros can build it in other crates.
+/// But this is an implementation detail and should not be used directly.
+#[doc(hidden)]
+pub type MacroActionBuilder = fn() -> ActionData;
+
+/// This constant must be public to be accessible from other crates.
+/// But it's existence is an implementation detail and should not be used directly.
+#[doc(hidden)]
+#[linkme::distributed_slice]
+pub static __GPUI_ACTIONS: [MacroActionBuilder];
+
+fn qualify_name(action_name: &'static str) -> SharedString {
+    let mut separator_matches = action_name.rmatch_indices("::");
+    separator_matches.next().unwrap();
+    let name_start_ix = separator_matches.next().map_or(0, |(ix, _)| ix + 2);
+    // todo!() remove the 2 replacement when migration is done
+    action_name[name_start_ix..].replace("2::", "::").into()
+}
+
+pub(crate) fn load_actions_2() {
+    let mut lock = ACTION_REGISTRY.write();
+
+    for action in __GPUI_ACTIONS {
+        let action = action();
+        let name = qualify_name(action.name);
+        lock.builders_by_name.insert(name.clone(), action.build);
+        lock.names_by_type_id.insert(action.type_id, name.clone());
+        lock.all_names.push(name);
+    }
+}

crates/gpui2/src/gpui2.rs

@@ -49,6 +49,7 @@ pub use input::*;
 pub use interactive::*;
 pub use key_dispatch::*;
 pub use keymap::*;
+pub use linkme;
 pub use platform::*;
 use private::Sealed;
 pub use refineable::*;

crates/gpui2_macros/Cargo.toml

@@ -9,6 +9,6 @@ path = "src/gpui2_macros.rs"
 proc-macro = true
 
 [dependencies]
-syn = "1.0.72"
+syn = { version = "1.0.72", features = ["full"] }
 quote = "1.0.9"
 proc-macro2 = "1.0.66"

crates/gpui2_macros/src/register_action.rs

@@ -18,14 +18,31 @@ use syn::{parse_macro_input, DeriveInput};
 pub fn register_action(_attr: TokenStream, item: TokenStream) -> TokenStream {
     let input = parse_macro_input!(item as DeriveInput);
     let type_name = &input.ident;
-    let ctor_fn_name = format_ident!("register_{}_builder", type_name.to_string().to_lowercase());
+
+    let static_slice_name =
+        format_ident!("__GPUI_ACTIONS_{}", type_name.to_string().to_uppercase());
+
+    let action_builder_fn_name = format_ident!(
+        "__gpui_actions_builder_{}",
+        type_name.to_string().to_lowercase()
+    );
 
     let expanded = quote! {
         #input
-        #[allow(non_snake_case)]
-        #[gpui::ctor]
-        fn #ctor_fn_name() {
-            gpui::register_action::<#type_name>()
+
+        #[doc(hidden)]
+        #[gpui::linkme::distributed_slice(gpui::__GPUI_ACTIONS)]
+        #[linkme(crate = gpui::linkme)]
+        static #static_slice_name: gpui::MacroActionBuilder = #action_builder_fn_name;
+
+        /// This is an auto generated function, do not use.
+        #[doc(hidden)]
+        fn #action_builder_fn_name() -> gpui::ActionData {
+            gpui::ActionData {
+                name: ::std::any::type_name::<#type_name>(),
+                type_id: ::std::any::TypeId::of::<#type_name>(),
+                build: <#type_name as gpui::Action>::build,
+            }
         }
     };