Merge #3800

3800: Introduce ra_proc_macro_srv r=matklad a=edwin0cheng

This PR add preliminary for server side of proc macro : 

1. Add crate setup
2. IO for server side


Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 55 insertions, 0 deletions

diff --git a/crates/ra_proc_macro_srv/src/main.rs b/crates/ra_proc_macro_srv/src/main.rs
new file mode 100644
index 000000000..70743c1f4
--- /dev/null
+++ b/crates/ra_proc_macro_srv/src/main.rs
@@ -0,0 +1,55 @@
+//! Driver for proc macro server
+
+use ra_proc_macro::msg::{self, Message};
+use ra_proc_macro_srv::{expand_task, list_macros};
+
+use std::io;
+
+fn read_request() -> Result<Option<msg::Request>, io::Error> {
+    let stdin = io::stdin();
+    let mut stdin = stdin.lock();
+    msg::Request::read(&mut stdin)
+}
+
+fn write_response(res: Result<msg::Response, String>) -> Result<(), io::Error> {
+    let msg: msg::Response = match res {
+        Ok(res) => res,
+        Err(err) => msg::Response::Error(msg::ResponseError {
+            code: msg::ErrorCode::ExpansionError,
+            message: err,
+        }),
+    };
+
+    let stdout = io::stdout();
+    let mut stdout = stdout.lock();
+    msg.write(&mut stdout)
+}
+fn main() {
+    loop {
+        let req = match read_request() {
+            Err(err) => {
+                eprintln!("Read message error on ra_proc_macro_srv: {}", err.to_string());
+                continue;
+            }
+            Ok(None) => continue,
+            Ok(Some(req)) => req,
+        };
+
+        match req {
+            msg::Request::ListMacro(task) => {
+                if let Err(err) =
+                    write_response(list_macros(&task).map(|it| msg::Response::ListMacro(it)))
+                {
+                    eprintln!("Write message error on list macro: {}", err);
+                }
+            }
+            msg::Request::ExpansionMacro(task) => {
+                if let Err(err) =
+                    write_response(expand_task(&task).map(|it| msg::Response::ExpansionMacro(it)))
+                {
+                    eprintln!("Write message error on expansion macro: {}", err);
+                }
+            }
+        }
+    }
+}