feat: add proc-macro rebuild on save option

crates/rust-analyzer/src/config.rs

@@ -105,6 +105,9 @@ config_data! {
         /// ```
         /// .
         cargo_buildScripts_overrideCommand: Option<Vec<String>> = "null",
+        /// Rerun proc-macros building/build-scripts running when proc-macro
+        /// or build-script sources change and are saved.
+        cargo_buildScripts_rebuildOnSave: bool = "false",
         /// Use `RUSTC_WRAPPER=rust-analyzer` when running build scripts to
         /// avoid checking unnecessary things.
         cargo_buildScripts_useRustcWrapper: bool = "true",
@@ -1368,6 +1371,10 @@ impl Config {
         self.data.checkOnSave
     }
 
+    pub fn script_rebuild_on_save(&self) -> bool {
+        self.data.cargo_buildScripts_rebuildOnSave
+    }
+
     pub fn runnables(&self) -> RunnablesConfig {
         RunnablesConfig {
             override_cargo: self.data.runnables_command.clone(),

crates/rust-analyzer/src/handlers/notification.rs

@@ -130,6 +130,13 @@ pub(crate) fn handle_did_save_text_document(
     state: &mut GlobalState,
     params: DidSaveTextDocumentParams,
 ) -> anyhow::Result<()> {
+    if state.config.script_rebuild_on_save() && state.proc_macro_changed {
+        // reset the flag
+        state.proc_macro_changed = false;
+        // rebuild the proc macros
+        state.fetch_build_data_queue.request_op("ScriptRebuildOnSave".to_owned(), ());
+    }
+
     if let Ok(vfs_path) = from_proto::vfs_path(&params.text_document.uri) {
         // Re-fetch workspaces if a workspace related file has changed
         if let Some(abs_path) = vfs_path.as_path() {

docs/user/generated_config.adoc

@@ -71,6 +71,12 @@ cargo check --quiet --workspace --message-format=json --all-targets
 ```
 .
 --
+[[rust-analyzer.cargo.buildScripts.rebuildOnSave]]rust-analyzer.cargo.buildScripts.rebuildOnSave (default: `false`)::
++
+--
+Rerun proc-macros building/build-scripts running when proc-macro
+or build-script sources change and are saved.
+--
 [[rust-analyzer.cargo.buildScripts.useRustcWrapper]]rust-analyzer.cargo.buildScripts.useRustcWrapper (default: `true`)::
 +
 --

editors/code/package.json

@@ -586,6 +586,11 @@
                         "type": "string"
                     }
                 },
+                "rust-analyzer.cargo.buildScripts.rebuildOnSave": {
+                    "markdownDescription": "Rerun proc-macros building/build-scripts running when proc-macro\nor build-script sources change and are saved.",
+                    "default": false,
+                    "type": "boolean"
+                },
                 "rust-analyzer.cargo.buildScripts.useRustcWrapper": {
                     "markdownDescription": "Use `RUSTC_WRAPPER=rust-analyzer` when running build scripts to\navoid checking unnecessary things.",
                     "default": true,