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]>

5 files changed, 164 insertions, 2 deletions

diff --git a/Cargo.lock b/Cargo.lock
index c07a9614a..016044f11 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -425,6 +425,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "goblin"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ddd5e3132801a1ac34ac53b97acde50c4685414dd2f291b9ea52afa6f07468c8"
+dependencies = [
+ "log",
+ "plain",
+ "scroll",
+]
+
+[[package]]
 name = "heck"
 version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -596,6 +607,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dea0c0405123bba743ee3f91f49b1c7cfb684eef0da0a50110f758ccf24cdff0"
 
 [[package]]
+name = "libloading"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2b111a074963af1d37a139918ac6d49ad1d0d5e47f72fd55388619691a7d753"
+dependencies = [
+ "cc",
+ "winapi 0.3.8",
+]
+
+[[package]]
 name = "linked-hash-map"
 version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -835,6 +856,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3ad1f1b834a05d42dae330066e9699a173b28185b3bdc3dbf14ca239585de8cc"
 
 [[package]]
+name = "plain"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
+
+[[package]]
 name = "ppv-lite86"
 version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1084,6 +1111,22 @@ dependencies = [
 ]
 
 [[package]]
+name = "ra_proc_macro_srv"
+version = "0.1.0"
+dependencies = [
+ "cargo_metadata",
+ "difference",
+ "goblin",
+ "libloading",
+ "ra_mbe",
+ "ra_proc_macro",
+ "ra_tt",
+ "serde",
+ "serde_derive",
+ "serde_json",
+]
+
+[[package]]
 name = "ra_prof"
 version = "0.1.0"
 dependencies = [
@@ -1393,6 +1436,26 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
+name = "scroll"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "abb2332cb595d33f7edd5700f4cbf94892e680c7f0ae56adab58a35190b66cb1"
+dependencies = [
+ "scroll_derive",
+]
+
+[[package]]
+name = "scroll_derive"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8584eea9b9ff42825b46faf46a8c24d2cff13ec152fa2a50df788b87c07ee28"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "semver"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/crates/ra_proc_macro/src/lib.rs b/crates/ra_proc_macro/src/lib.rs
index 51fbb046a..63da9f1b4 100644
--- a/crates/ra_proc_macro/src/lib.rs
+++ b/crates/ra_proc_macro/src/lib.rs
@@ -11,13 +11,12 @@ pub mod msg;
 
 use process::{ProcMacroProcessSrv, ProcMacroProcessThread};
 use ra_tt::{SmolStr, Subtree};
-use rpc::ProcMacroKind;
 use std::{
     path::{Path, PathBuf},
     sync::Arc,
 };
 
-pub use rpc::{ExpansionResult, ExpansionTask};
+pub use rpc::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTask, ProcMacroKind};
 
 #[derive(Debug, Clone)]
 pub struct ProcMacroProcessExpander {
diff --git a/crates/ra_proc_macro_srv/Cargo.toml b/crates/ra_proc_macro_srv/Cargo.toml
new file mode 100644
index 000000000..fa2de2c91
--- /dev/null
+++ b/crates/ra_proc_macro_srv/Cargo.toml
@@ -0,0 +1,24 @@
+[package]
+edition = "2018"
+name = "ra_proc_macro_srv"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+publish = false
+
+[lib]
+doctest = false
+
+[dependencies]
+ra_tt = { path = "../ra_tt" }
+ra_mbe = { path = "../ra_mbe" }
+ra_proc_macro = { path = "../ra_proc_macro" }
+
+serde_derive = "1.0.104"
+serde = "1.0.104"
+serde_json = "1.0.48"
+libloading = "0.5.2"
+goblin = "0.2.0"
+
+[dev-dependencies]
+cargo_metadata = "0.9.1"
+difference = "2.0.0"
diff --git a/crates/ra_proc_macro_srv/src/lib.rs b/crates/ra_proc_macro_srv/src/lib.rs
new file mode 100644
index 000000000..f77be1475
--- /dev/null
+++ b/crates/ra_proc_macro_srv/src/lib.rs
@@ -0,0 +1,21 @@
+//! RA Proc Macro Server
+//!
+//! This library is able to call compiled Rust custom derive dynamic libraries on arbitrary code.
+//! The general idea here is based on https://github.com/fedochet/rust-proc-macro-expander.
+//!
+//! But we change some several design for fitting RA needs:
+//!
+//! * We use `ra_tt` for proc-macro `TokenStream` server, it is easy to manipute and interact with
+//!   RA then proc-macro2 token stream.
+//! * By **copying** the whole rustc `lib_proc_macro` code, we are able to build this with `stable`
+//!   rustc rather than `unstable`. (Although in gerenal ABI compatibility is still an issue)
+
+use ra_proc_macro::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTask};
+
+pub fn expand_task(_task: &ExpansionTask) -> Result<ExpansionResult, String> {
+    unimplemented!()
+}
+
+pub fn list_macros(_task: &ListMacrosTask) -> Result<ListMacrosResult, String> {
+    unimplemented!()
+}
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);
+                }
+            }
+        }
+    }
+}