Move proc-macro protocol into legacy module

crates/load-cargo/src/lib.rs

@@ -82,7 +82,7 @@ pub fn load_workspace(
     };
     match &proc_macro_server {
         Ok(server) => {
-            tracing::info!(path=%server.path(), "Proc-macro server started")
+            tracing::info!(path=%server.server_path(), "Proc-macro server started")
         }
         Err((e, _)) => {
             tracing::info!(%e, "Failed to start proc-macro server")

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

@@ -9,7 +9,7 @@ use serde_derive::{Deserialize, Serialize};
 
 use crate::ProcMacroKind;
 
-pub use crate::msg::flat::{
+pub use self::flat::{
     deserialize_span_data_index_map, serialize_span_data_index_map, FlatTree, SpanDataIndexMap,
 };
 pub use span::TokenId;

crates/proc-macro-api/src/legacy_protocol/msg/flat.rs

@@ -44,7 +44,7 @@ use span::{
     EditionedFileId, ErasedFileAstId, Span, SpanAnchor, SyntaxContextId, TextRange, TokenId,
 };
 
-use crate::msg::{ENCODE_CLOSE_SPAN_VERSION, EXTENDED_LEAF_DATA};
+use crate::legacy_protocol::msg::{ENCODE_CLOSE_SPAN_VERSION, EXTENDED_LEAF_DATA};
 
 pub type SpanDataIndexMap =
     indexmap::IndexSet<Span, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;

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

@@ -5,8 +5,10 @@
 //! is used to provide basic infrastructure for communication between two
 //! processes: Client (RA itself), Server (the external program)
 
-pub mod json;
+pub mod legacy_protocol {
-pub mod msg;
+    pub mod json;
+    pub mod msg;
+}
 mod process;
 
 use paths::{AbsPath, AbsPathBuf};
@@ -14,10 +16,10 @@ use span::Span;
 use std::{fmt, io, sync::Arc};
 
 use crate::{
-    msg::{
+    legacy_protocol::msg::{
         deserialize_span_data_index_map, flat::serialize_span_data_index_map, ExpandMacro,
-        ExpnGlobals, FlatTree, PanicMessage, SpanDataIndexMap, HAS_GLOBAL_SPANS,
+        ExpandMacroData, ExpnGlobals, FlatTree, PanicMessage, Request, Response, SpanDataIndexMap,
-        RUST_ANALYZER_SPAN_SUPPORT,
+        HAS_GLOBAL_SPANS, RUST_ANALYZER_SPAN_SUPPORT,
     },
     process::ProcMacroServerProcess,
 };
@@ -54,10 +56,10 @@ impl MacroDylib {
     }
 }
 
-/// A handle to a specific macro (a `#[proc_macro]` annotated function).
+/// A handle to a specific proc-macro (a `#[proc_macro]` annotated function).
 ///
-/// It exists within a context of a specific [`ProcMacroProcess`] -- currently
+/// It exists within the context of a specific proc-macro server -- currently
-/// we share a single expander process for all macros.
+/// we share a single expander process for all macros within a workspace.
 #[derive(Debug, Clone)]
 pub struct ProcMacro {
     process: Arc<ProcMacroServerProcess>,
@@ -104,10 +106,11 @@ impl ProcMacroClient {
         Ok(ProcMacroClient { process: Arc::new(process), path: process_path.to_owned() })
     }
 
-    pub fn path(&self) -> &AbsPath {
+    pub fn server_path(&self) -> &AbsPath {
         &self.path
     }
 
+    /// Loads a proc-macro dylib into the server process returning a list of `ProcMacro`s loaded.
     pub fn load_dylib(&self, dylib: MacroDylib) -> Result<Vec<ProcMacro>, ServerError> {
         let _p = tracing::info_span!("ProcMacroServer::load_dylib").entered();
         let macros = self.process.find_proc_macros(&dylib.path)?;
@@ -158,7 +161,7 @@ impl ProcMacro {
         let call_site = span_data_table.insert_full(call_site).0;
         let mixed_site = span_data_table.insert_full(mixed_site).0;
         let task = ExpandMacro {
-            data: msg::ExpandMacroData {
+            data: ExpandMacroData {
                 macro_body: FlatTree::new(subtree, version, &mut span_data_table),
                 macro_name: self.name.to_string(),
                 attributes: attr
@@ -180,13 +183,13 @@ impl ProcMacro {
             current_dir,
         };
 
-        let response = self.process.send_task(msg::Request::ExpandMacro(Box::new(task)))?;
+        let response = self.process.send_task(Request::ExpandMacro(Box::new(task)))?;
 
         match response {
-            msg::Response::ExpandMacro(it) => {
+            Response::ExpandMacro(it) => {
                 Ok(it.map(|tree| FlatTree::to_subtree_resolved(tree, version, &span_data_table)))
             }
-            msg::Response::ExpandMacroExtended(it) => Ok(it.map(|resp| {
+            Response::ExpandMacroExtended(it) => Ok(it.map(|resp| {
                 FlatTree::to_subtree_resolved(
                     resp.tree,
                     version,

crates/proc-macro-api/src/process.rs

@@ -11,8 +11,13 @@ use paths::AbsPath;
 use stdx::JodChild;
 
 use crate::{
-    json::{read_json, write_json},
+    legacy_protocol::{
-    msg::{Message, Request, Response, SpanMode, CURRENT_API_VERSION, RUST_ANALYZER_SPAN_SUPPORT},
+        json::{read_json, write_json},
+        msg::{
+            Message, Request, Response, ServerConfig, SpanMode, CURRENT_API_VERSION,
+            RUST_ANALYZER_SPAN_SUPPORT,
+        },
+    },
     ProcMacroKind, ServerError,
 };
 
@@ -40,8 +45,8 @@ impl ProcMacroServerProcess {
         env: impl IntoIterator<Item = (impl AsRef<std::ffi::OsStr>, impl AsRef<std::ffi::OsStr>)>
             + Clone,
     ) -> io::Result<ProcMacroServerProcess> {
-        let create_srv = |null_stderr| {
+        let create_srv = || {
-            let mut process = Process::run(process_path, env.clone(), null_stderr)?;
+            let mut process = Process::run(process_path, env.clone())?;
             let (stdin, stdout) = process.stdio().expect("couldn't access child stdio");
 
             io::Result::Ok(ProcMacroServerProcess {
@@ -51,7 +56,7 @@ impl ProcMacroServerProcess {
                 exited: OnceLock::new(),
             })
         };
-        let mut srv = create_srv(true)?;
+        let mut srv = create_srv()?;
         tracing::info!("sending proc-macro server version check");
         match srv.version_check() {
             Ok(v) if v > CURRENT_API_VERSION => Err(io::Error::new(
@@ -62,7 +67,6 @@ impl ProcMacroServerProcess {
             )),
             Ok(v) => {
                 tracing::info!("Proc-macro server version: {v}");
-                srv = create_srv(false)?;
                 srv.version = v;
                 if srv.version >= RUST_ANALYZER_SPAN_SUPPORT {
                     if let Ok(mode) = srv.enable_rust_analyzer_spans() {
@@ -73,8 +77,10 @@ impl ProcMacroServerProcess {
                 Ok(srv)
             }
             Err(e) => {
-                tracing::info!(%e, "proc-macro version check failed, restarting and assuming version 0");
+                tracing::info!(%e, "proc-macro version check failed");
-                create_srv(false)
+                Err(
+                    io::Error::new(io::ErrorKind::Other, format!("proc-macro server version check failed: {e}")),
+                )
             }
         }
     }
@@ -98,13 +104,11 @@ impl ProcMacroServerProcess {
     }
 
     fn enable_rust_analyzer_spans(&self) -> Result<SpanMode, ServerError> {
-        let request = Request::SetConfig(crate::msg::ServerConfig {
+        let request = Request::SetConfig(ServerConfig { span_mode: SpanMode::RustAnalyzer });
-            span_mode: crate::msg::SpanMode::RustAnalyzer,
-        });
         let response = self.send_task(request)?;
 
         match response {
-            Response::SetConfig(crate::msg::ServerConfig { span_mode }) => Ok(span_mode),
+            Response::SetConfig(ServerConfig { span_mode }) => Ok(span_mode),
             _ => Err(ServerError { message: "unexpected response".to_owned(), io: None }),
         }
     }
@@ -182,9 +186,8 @@ impl Process {
     fn run(
         path: &AbsPath,
         env: impl IntoIterator<Item = (impl AsRef<std::ffi::OsStr>, impl AsRef<std::ffi::OsStr>)>,
-        null_stderr: bool,
     ) -> io::Result<Process> {
-        let child = JodChild(mk_child(path, env, null_stderr)?);
+        let child = JodChild(mk_child(path, env)?);
         Ok(Process { child })
     }
 
@@ -200,7 +203,6 @@ impl Process {
 fn mk_child(
     path: &AbsPath,
     env: impl IntoIterator<Item = (impl AsRef<std::ffi::OsStr>, impl AsRef<std::ffi::OsStr>)>,
-    null_stderr: bool,
 ) -> io::Result<Child> {
     #[allow(clippy::disallowed_methods)]
     let mut cmd = Command::new(path);
@@ -208,7 +210,7 @@ fn mk_child(
         .env("RUST_ANALYZER_INTERNALS_DO_NOT_USE", "this is unstable")
         .stdin(Stdio::piped())
         .stdout(Stdio::piped())
-        .stderr(if null_stderr { Stdio::null() } else { Stdio::inherit() });
+        .stderr(Stdio::inherit());
     if cfg!(windows) {
         let mut path_var = std::ffi::OsString::new();
         path_var.push(path.parent().unwrap().parent().unwrap());

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

@@ -1,7 +1,7 @@
 //! The main loop of the proc-macro server.
 use std::io;
 
-use proc_macro_api::{
+use proc_macro_api::legacy_protocol::{
     json::{read_json, write_json},
     msg::{
         self, deserialize_span_data_index_map, serialize_span_data_index_map, ExpandMacroData,