//! 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 . //! //! But we adapt it to better fit RA needs: //! //! * We use `tt` for proc-macro `TokenStream` server, it is easier to manipulate and interact with //! RA than `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 general ABI compatibility is still an issue)… #![allow(unreachable_pub)] mod dylib; mod abis; use std::{ collections::{hash_map::Entry, HashMap}, env, fs, path::{Path, PathBuf}, time::SystemTime, }; use proc_macro_api::{ msg::{ExpandMacro, FlatTree, PanicMessage}, ProcMacroKind, }; #[derive(Default)] pub(crate) struct ProcMacroSrv { expanders: HashMap<(PathBuf, SystemTime), dylib::Expander>, } impl ProcMacroSrv { pub fn expand(&mut self, task: ExpandMacro) -> Result { let expander = self.expander(task.lib.as_ref()).map_err(|err| { debug_assert!(false, "should list macros before asking to expand"); PanicMessage(format!("failed to load macro: {}", err)) })?; let mut prev_env = HashMap::new(); for (k, v) in &task.env { prev_env.insert(k.as_str(), env::var_os(k)); env::set_var(k, v); } let prev_working_dir = match task.current_dir { Some(dir) => { let prev_working_dir = std::env::current_dir().ok(); if let Err(err) = std::env::set_current_dir(&dir) { eprintln!("Failed to set the current working dir to {}. Error: {:?}", dir, err) } prev_working_dir } None => None, }; let macro_body = task.macro_body.to_subtree(); let attributes = task.attributes.map(|it| it.to_subtree()); let result = expander .expand(&task.macro_name, ¯o_body, attributes.as_ref()) .map(|it| FlatTree::new(&it)); for (k, _) in &task.env { match &prev_env[k.as_str()] { Some(v) => env::set_var(k, v), None => env::remove_var(k), } } if let Some(dir) = prev_working_dir { if let Err(err) = std::env::set_current_dir(&dir) { eprintln!( "Failed to set the current working dir to {}. Error: {:?}", dir.display(), err ) } } result.map_err(PanicMessage) } pub(crate) fn list_macros( &mut self, dylib_path: &Path, ) -> Result, String> { let expander = self.expander(dylib_path)?; Ok(expander.list_macros()) } fn expander(&mut self, path: &Path) -> Result<&dylib::Expander, String> { let time = fs::metadata(path).and_then(|it| it.modified()).map_err(|err| { format!("Failed to get file metadata for {}: {:?}", path.display(), err) })?; Ok(match self.expanders.entry((path.to_path_buf(), time)) { Entry::Vacant(v) => v.insert(dylib::Expander::new(path).map_err(|err| { format!("Cannot create expander for {}: {:?}", path.display(), err) })?), Entry::Occupied(e) => e.into_mut(), }) } } pub mod cli; #[cfg(test)] mod tests;