Merge pull request #21377 from Shourya742/2025-12-31-add-more-proc-macro-bidirectional-flow

proc-macro-srv: support file and local_file via bidirectional callbacks

Author: Veykril

crates/load-cargo/src/lib.rs

@@ -540,12 +540,37 @@ impl ProcMacroExpander for Expander {
         current_dir: String,
     ) -> Result<tt::TopSubtree, ProcMacroExpansionError> {
         let mut cb = |req| match req {
+            SubRequest::LocalFilePath { file_id } => {
+                let file = FileId::from_raw(file_id);
+                let source_root_id = db.file_source_root(file).source_root_id(db);
+                let source_root = db.source_root(source_root_id).source_root(db);
+
+                let name = source_root
+                    .path_for_file(&file)
+                    .and_then(|path| path.as_path())
+                    .map(|path| path.to_string());
+
+                Ok(SubResponse::LocalFilePathResult { name })
+            }
             SubRequest::SourceText { file_id, start, end } => {
                 let file = FileId::from_raw(file_id);
                 let text = db.file_text(file).text(db);
                 let slice = text.get(start as usize..end as usize).map(ToOwned::to_owned);
                 Ok(SubResponse::SourceTextResult { text: slice })
             }
+            SubRequest::FilePath { file_id } => {
+                let file = FileId::from_raw(file_id);
+                let source_root_id = db.file_source_root(file).source_root_id(db);
+                let source_root = db.source_root(source_root_id).source_root(db);
+
+                let name = source_root
+                    .path_for_file(&file)
+                    .and_then(|path| path.as_path())
+                    .map(|path| path.to_string())
+                    .unwrap_or_default();
+
+                Ok(SubResponse::FilePathResult { name })
+            }
         };
         match self.0.expand(
             subtree.view(),

crates/proc-macro-api/src/bidirectional_protocol/msg.rs

@@ -10,12 +10,16 @@ use crate::{
 
 #[derive(Debug, Serialize, Deserialize)]
 pub enum SubRequest {
+    FilePath { file_id: u32 },
     SourceText { file_id: u32, start: u32, end: u32 },
+    LocalFilePath { file_id: u32 },
 }
 
 #[derive(Debug, Serialize, Deserialize)]
 pub enum SubResponse {
+    FilePathResult { name: String },
     SourceTextResult { text: Option<String> },
+    LocalFilePathResult { name: Option<String> },
 }
 
 #[derive(Debug, Serialize, Deserialize)]

crates/proc-macro-srv-cli/src/main_loop.rs

@@ -81,7 +81,6 @@ fn run_new<C: Codec>() -> io::Result<()> {
                 }
 
                 bidirectional::Request::ApiVersionCheck {} => {
-                    // bidirectional::Response::ApiVersionCheck(CURRENT_API_VERSION).write::<_, C>(stdout)
                     send_response::<C>(
                         &stdout,
                         bidirectional::Response::ApiVersionCheck(CURRENT_API_VERSION),
@@ -167,28 +166,48 @@ struct ProcMacroClientHandle<'a, C: Codec> {
     buf: &'a mut C::Buf,
 }
 
-impl<C: Codec> proc_macro_srv::ProcMacroClientInterface for ProcMacroClientHandle<'_, C> {
-    fn source_text(&mut self, file_id: u32, start: u32, end: u32) -> Option<String> {
-        let req = bidirectional::BidirectionalMessage::SubRequest(
-            bidirectional::SubRequest::SourceText { file_id, start, end },
-        );
+impl<'a, C: Codec> ProcMacroClientHandle<'a, C> {
+    fn roundtrip(
+        &mut self,
+        req: bidirectional::SubRequest,
+    ) -> Option<bidirectional::BidirectionalMessage> {
+        let msg = bidirectional::BidirectionalMessage::SubRequest(req);
 
-        if req.write::<_, C>(&mut self.stdout.lock()).is_err() {
+        if msg.write::<_, C>(&mut self.stdout.lock()).is_err() {
             return None;
         }
 
-        let msg = match bidirectional::BidirectionalMessage::read::<_, C>(
-            &mut self.stdin.lock(),
-            self.buf,
-        ) {
-            Ok(Some(msg)) => msg,
-            _ => return None,
-        };
+        match bidirectional::BidirectionalMessage::read::<_, C>(&mut self.stdin.lock(), self.buf) {
+            Ok(Some(msg)) => Some(msg),
+            _ => None,
+        }
+    }
+}
+
+impl<C: Codec> proc_macro_srv::ProcMacroClientInterface for ProcMacroClientHandle<'_, C> {
+    fn file(&mut self, file_id: u32) -> String {
+        match self.roundtrip(bidirectional::SubRequest::FilePath { file_id }) {
+            Some(bidirectional::BidirectionalMessage::SubResponse(
+                bidirectional::SubResponse::FilePathResult { name },
+            )) => name,
+            _ => String::new(),
+        }
+    }
 
-        match msg {
-            bidirectional::BidirectionalMessage::SubResponse(
+    fn source_text(&mut self, file_id: u32, start: u32, end: u32) -> Option<String> {
+        match self.roundtrip(bidirectional::SubRequest::SourceText { file_id, start, end }) {
+            Some(bidirectional::BidirectionalMessage::SubResponse(
                 bidirectional::SubResponse::SourceTextResult { text },
-            ) => text,
+            )) => text,
+            _ => None,
+        }
+    }
+
+    fn local_file(&mut self, file_id: u32) -> Option<String> {
+        match self.roundtrip(bidirectional::SubRequest::LocalFilePath { file_id }) {
+            Some(bidirectional::BidirectionalMessage::SubResponse(
+                bidirectional::SubResponse::LocalFilePathResult { name },
+            )) => name,
             _ => None,
         }
     }

crates/proc-macro-srv/src/lib.rs

@@ -94,7 +94,9 @@ impl<'env> ProcMacroSrv<'env> {
 pub type ProcMacroClientHandle<'a> = &'a mut (dyn ProcMacroClientInterface + Sync + Send);
 
 pub trait ProcMacroClientInterface {
+    fn file(&mut self, file_id: u32) -> String;
     fn source_text(&mut self, file_id: u32, start: u32, end: u32) -> Option<String>;
+    fn local_file(&mut self, file_id: u32) -> Option<String>;
 }
 
 const EXPANDER_STACK_SIZE: usize = 8 * 1024 * 1024;

crates/proc-macro-srv/src/server_impl/rust_analyzer_span.rs

@@ -127,13 +127,14 @@ impl server::Span for RaSpanServer<'_> {
     fn debug(&mut self, span: Self::Span) -> String {
         format!("{:?}", span)
     }
-    fn file(&mut self, _: Self::Span) -> String {
-        // FIXME
-        String::new()
-    }
-    fn local_file(&mut self, _: Self::Span) -> Option<String> {
-        // FIXME
-        None
+    fn file(&mut self, span: Self::Span) -> String {
+        self.callback
+            .as_mut()
+            .map(|cb| cb.file(span.anchor.file_id.file_id().index()))
+            .unwrap_or_default()
+    }
+    fn local_file(&mut self, span: Self::Span) -> Option<String> {
+        self.callback.as_mut().and_then(|cb| cb.local_file(span.anchor.file_id.file_id().index()))
     }
     fn save_span(&mut self, _span: Self::Span) -> usize {
         // FIXME, quote is incompatible with third-party tools