Merge #4061

4061: ra_proc_macro: cleanups here and there r=edwin0cheng a=Veetaha

r? @edwin0cheng 

Co-authored-by: veetaha <veetaha2@gmail.com>
Co-authored-by: Veetaha <veetaha2@gmail.com>

crates/ra_proc_macro/src/lib.rs

@@ -2,7 +2,7 @@
 //!
 //! We separate proc-macro expanding logic to an extern program to allow
 //! different implementations (e.g. wasm or dylib loading). And this crate
-//! is used to provide basic infrastructure  for communication between two
+//! is used to provide basic infrastructure for communication between two
 //! processes: Client (RA itself), Server (the external program)
 
 mod rpc;
@@ -13,6 +13,7 @@ use process::{ProcMacroProcessSrv, ProcMacroProcessThread};
 use ra_tt::{SmolStr, Subtree};
 use std::{
     ffi::OsStr,
+    io,
     path::{Path, PathBuf},
     sync::Arc,
 };
@@ -57,14 +58,10 @@ pub struct ProcMacroClient {
 }
 
 impl ProcMacroClient {
-    pub fn extern_process<I, S>(
-        process_path: &Path,
-        args: I,
-    ) -> Result<ProcMacroClient, std::io::Error>
-    where
-        I: IntoIterator<Item = S>,
-        S: AsRef<OsStr>,
-    {
+    pub fn extern_process(
+        process_path: PathBuf,
+        args: impl IntoIterator<Item = impl AsRef<OsStr>>,
+    ) -> io::Result<ProcMacroClient> {
         let (thread, process) = ProcMacroProcessSrv::run(process_path, args)?;
         Ok(ProcMacroClient {
             kind: ProcMacroClientKind::Process { process: Arc::new(process), thread },
@@ -84,7 +81,7 @@ impl ProcMacroClient {
             ProcMacroClientKind::Process { process, .. } => {
                 let macros = match process.find_proc_macros(dylib_path) {
                     Err(err) => {
-                        eprintln!("Fail to find proc macro. Error: {:#?}", err);
+                        eprintln!("Failed to find proc macros. Error: {:#?}", err);
                         return vec![];
                     }
                     Ok(macros) => macros,

crates/ra_proc_macro/src/msg.rs

@@ -1,4 +1,4 @@
-//! Defines messages for cross-process message based on `ndjson` wire protocol
+//! Defines messages for cross-process message passing based on `ndjson` wire protocol
 
 use std::{
     convert::TryFrom,
@@ -31,7 +31,7 @@ macro_rules! impl_try_from_response {
             fn try_from(value: Response) -> Result<Self, Self::Error> {
                 match value {
                     Response::$tag(res) => Ok(res),
-                    _ => Err("Fail to convert from response"),
+                    _ => Err(concat!("Failed to convert response to ", stringify!($tag))),
                 }
             }
         }
@@ -53,18 +53,16 @@ pub enum ErrorCode {
     ExpansionError,
 }
 
-pub trait Message: Sized + Serialize + DeserializeOwned {
-    fn read(r: &mut impl BufRead) -> io::Result<Option<Self>> {
-        let text = match read_json(r)? {
-            None => return Ok(None),
-            Some(text) => text,
-        };
-        let msg = serde_json::from_str(&text)?;
-        Ok(Some(msg))
+pub trait Message: Serialize + DeserializeOwned {
+    fn read(inp: &mut impl BufRead) -> io::Result<Option<Self>> {
+        Ok(match read_json(inp)? {
+            None => None,
+            Some(text) => Some(serde_json::from_str(&text)?),
+        })
     }
-    fn write(self, w: &mut impl Write) -> io::Result<()> {
+    fn write(self, out: &mut impl Write) -> io::Result<()> {
         let text = serde_json::to_string(&self)?;
-        write_json(w, &text)
+        write_json(out, &text)
     }
 }
 
@@ -73,15 +71,12 @@ impl Message for Response {}
 
 fn read_json(inp: &mut impl BufRead) -> io::Result<Option<String>> {
     let mut buf = String::new();
-    if inp.read_line(&mut buf)? == 0 {
-        return Ok(None);
-    }
-    // Remove ending '\n'
-    let buf = &buf[..buf.len() - 1];
-    if buf.is_empty() {
-        return Ok(None);
-    }
-    Ok(Some(buf.to_string()))
+    inp.read_line(&mut buf)?;
+    buf.pop(); // Remove traling '\n'
+    Ok(match buf.len() {
+        0 => None,
+        _ => Some(buf),
+    })
 }
 
 fn write_json(out: &mut impl Write, msg: &str) -> io::Result<()> {

crates/ra_proc_macro/src/process.rs

@@ -45,24 +45,23 @@ impl Drop for Process {
 }
 
 impl Process {
-    fn run<I, S>(process_path: &Path, args: I) -> Result<Process, io::Error>
-    where
-        I: IntoIterator<Item = S>,
-        S: AsRef<OsStr>,
-    {
-        let child = Command::new(process_path.clone())
+    fn run(
+        process_path: PathBuf,
+        args: impl IntoIterator<Item = impl AsRef<OsStr>>,
+    ) -> io::Result<Process> {
+        let child = Command::new(&process_path)
             .args(args)
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
             .stderr(Stdio::null())
             .spawn()?;
 
-        Ok(Process { path: process_path.into(), child })
+        Ok(Process { path: process_path, child })
     }
 
-    fn restart(&mut self) -> Result<(), io::Error> {
+    fn restart(&mut self) -> io::Result<()> {
         let _ = self.child.kill();
-        self.child = Command::new(self.path.clone())
+        self.child = Command::new(&self.path)
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
             .stderr(Stdio::null())
@@ -80,14 +79,10 @@ impl Process {
 }
 
 impl ProcMacroProcessSrv {
-    pub fn run<I, S>(
-        process_path: &Path,
-        args: I,
-    ) -> Result<(ProcMacroProcessThread, ProcMacroProcessSrv), io::Error>
-    where
-        I: IntoIterator<Item = S>,
-        S: AsRef<OsStr>,
-    {
+    pub fn run(
+        process_path: PathBuf,
+        args: impl IntoIterator<Item = impl AsRef<OsStr>>,
+    ) -> io::Result<(ProcMacroProcessThread, ProcMacroProcessSrv)> {
         let process = Process::run(process_path, args)?;
 
         let (task_tx, task_rx) = bounded(0);
@@ -201,7 +196,7 @@ fn send_request(
     mut writer: &mut impl Write,
     mut reader: &mut impl BufRead,
     req: Request,
-) -> Result<Option<Response>, io::Error> {
+) -> io::Result<Option<Response>> {
     req.write(&mut writer)?;
     Ok(Response::read(&mut reader)?)
 }

crates/ra_proc_macro/src/rpc.rs

@@ -1,9 +1,9 @@
-//! Data struture serialization related stuffs for RPC
+//! Data struture serialization related stuff for RPC
 //!
-//! Define all necessary rpc serialization data structure,
-//! which include ra_tt related data and some task messages.
-//! Although adding Serialize and Deserialize trait to ra_tt directly seem to be much easier,
-//! we deliberately duplicate the ra_tt struct with #[serde(with = "XXDef")]
+//! Defines all necessary rpc serialization data structures,
+//! which includes `ra_tt` related data and some task messages.
+//! Although adding `Serialize` and `Deserialize` traits to `ra_tt` directly seems
+//! to be much easier, we deliberately duplicate `ra_tt` structs with `#[serde(with = "XXDef")]`
 //! for separation of code responsibility.
 
 use ra_tt::{
@@ -34,15 +34,15 @@ pub struct ListMacrosResult {
 pub struct ExpansionTask {
     /// Argument of macro call.
     ///
-    /// In custom derive that would be a struct or enum; in attribute-like macro - underlying
+    /// In custom derive this will be a struct or enum; in attribute-like macro - underlying
     /// item; in function-like macro - the macro body.
     #[serde(with = "SubtreeDef")]
     pub macro_body: Subtree,
 
-    /// Names of macros to expand.
+    /// Name of macro to expand.
     ///
-    /// In custom derive those are names of derived traits (`Serialize`, `Getters`, etc.). In
-    /// attribute-like and functiona-like macros - single name of macro itself (`show_streams`).
+    /// In custom derive this is the name of the derived trait (`Serialize`, `Getters`, etc.).
+    /// In attribute-like and function-like macros - single name of macro itself (`show_streams`).
     pub macro_name: String,
 
     /// Possible attributes for the attribute-like macros.

crates/ra_proc_macro_srv/src/cli.rs

@@ -2,55 +2,43 @@
 
 use crate::{expand_task, list_macros};
 use ra_proc_macro::msg::{self, Message};
-
 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)
-}
-
 pub fn run() {
     loop {
         let req = match read_request() {
             Err(err) => {
-                eprintln!("Read message error on ra_proc_macro_srv: {}", err.to_string());
+                eprintln!("Read message error on ra_proc_macro_srv: {}", err);
                 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);
-                }
-            }
+        let res = match req {
+            msg::Request::ListMacro(task) => Ok(msg::Response::ListMacro(list_macros(&task))),
             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);
-                }
+                expand_task(&task).map(msg::Response::ExpansionMacro)
             }
+        };
+
+        let msg = res.unwrap_or_else(|err| {
+            msg::Response::Error(msg::ResponseError {
+                code: msg::ErrorCode::ExpansionError,
+                message: err,
+            })
+        });
+
+        if let Err(err) = write_response(msg) {
+            eprintln!("Write message error: {}", err);
         }
     }
 }
+
+fn read_request() -> io::Result<Option<msg::Request>> {
+    msg::Request::read(&mut io::stdin().lock())
+}
+
+fn write_response(msg: msg::Response) -> io::Result<()> {
+    msg.write(&mut io::stdout().lock())
+}

crates/ra_proc_macro_srv/src/dylib.rs

@@ -9,43 +9,37 @@ use libloading::Library;
 use memmap::Mmap;
 use ra_proc_macro::ProcMacroKind;
 
-use std::io::Error as IoError;
-use std::io::ErrorKind as IoErrorKind;
+use std::io;
 
 const NEW_REGISTRAR_SYMBOL: &str = "_rustc_proc_macro_decls_";
 
-fn invalid_data_err(e: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> IoError {
-    IoError::new(IoErrorKind::InvalidData, e)
+fn invalid_data_err(e: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> io::Error {
+    io::Error::new(io::ErrorKind::InvalidData, e)
 }
 
 fn is_derive_registrar_symbol(symbol: &str) -> bool {
     symbol.contains(NEW_REGISTRAR_SYMBOL)
 }
 
-fn find_registrar_symbol(file: &Path) -> Result<Option<String>, IoError> {
+fn find_registrar_symbol(file: &Path) -> io::Result<Option<String>> {
     let file = File::open(file)?;
     let buffer = unsafe { Mmap::map(&file)? };
     let object = Object::parse(&buffer).map_err(invalid_data_err)?;
 
-    match object {
+    let name = match object {
         Object::Elf(elf) => {
             let symbols = elf.dynstrtab.to_vec().map_err(invalid_data_err)?;
-            let name =
-                symbols.iter().find(|s| is_derive_registrar_symbol(s)).map(|s| s.to_string());
-            Ok(name)
-        }
-        Object::PE(pe) => {
-            let name = pe
-                .exports
-                .iter()
-                .flat_map(|s| s.name)
-                .find(|s| is_derive_registrar_symbol(s))
-                .map(|s| s.to_string());
-            Ok(name)
+            symbols.into_iter().find(|s| is_derive_registrar_symbol(s)).map(&str::to_owned)
         }
+        Object::PE(pe) => pe
+            .exports
+            .iter()
+            .flat_map(|s| s.name)
+            .find(|s| is_derive_registrar_symbol(s))
+            .map(&str::to_owned),
         Object::Mach(Mach::Binary(binary)) => {
             let exports = binary.exports().map_err(invalid_data_err)?;
-            let name = exports
+            exports
                 .iter()
                 .map(|s| {
                     // In macos doc:
@@ -59,11 +53,11 @@ fn find_registrar_symbol(file: &Path) -> Result<Option<String>, IoError> {
                     }
                 })
                 .find(|s| is_derive_registrar_symbol(s))
-                .map(|s| s.to_string());
-            Ok(name)
+                .map(&str::to_owned)
         }
-        _ => Ok(None),
-    }
+        _ => return Ok(None),
+    };
+    return Ok(name);
 }
 
 /// Loads dynamic library in platform dependent manner.
@@ -93,15 +87,16 @@ fn load_library(file: &Path) -> Result<Library, libloading::Error> {
 }
 
 struct ProcMacroLibraryLibloading {
-    // Hold the dylib to prevent it for unloadeding
+    // Hold the dylib to prevent it from unloading
     _lib: Library,
     exported_macros: Vec<bridge::client::ProcMacro>,
 }
 
 impl ProcMacroLibraryLibloading {
-    fn open(file: &Path) -> Result<Self, IoError> {
-        let symbol_name = find_registrar_symbol(file)?
-            .ok_or(invalid_data_err(format!("Cannot find registrar symbol in file {:?}", file)))?;
+    fn open(file: &Path) -> io::Result<Self> {
+        let symbol_name = find_registrar_symbol(file)?.ok_or_else(|| {
+            invalid_data_err(format!("Cannot find registrar symbol in file {}", file.display()))
+        })?;
 
         let lib = load_library(file).map_err(invalid_data_err)?;
         let exported_macros = {
@@ -121,18 +116,16 @@ pub struct Expander {
 }
 
 impl Expander {
-    pub fn new<P: AsRef<Path>>(lib: &P) -> Result<Expander, String> {
-        let mut libs = vec![];
-        /* Some libraries for dynamic loading require canonicalized path (even when it is
-        already absolute
-        */
-        let lib =
-            lib.as_ref().canonicalize().expect(&format!("Cannot canonicalize {:?}", lib.as_ref()));
+    pub fn new(lib: &Path) -> Result<Expander, String> {
+        // Some libraries for dynamic loading require canonicalized path even when it is
+        // already absolute
+        let lib = lib
+            .canonicalize()
+            .unwrap_or_else(|err| panic!("Cannot canonicalize {}: {:?}", lib.display(), err));
 
         let library = ProcMacroLibraryImpl::open(&lib).map_err(|e| e.to_string())?;
-        libs.push(library);
 
-        Ok(Expander { libs })
+        Ok(Expander { libs: vec![library] })
     }
 
     pub fn expand(
@@ -176,7 +169,6 @@ impl Expander {
                             parsed_attributes,
                             parsed_body,
                         );
-
                         return res.map(|it| it.subtree);
                     }
                     _ => continue,
@@ -187,26 +179,21 @@ impl Expander {
         Err(bridge::PanicMessage::String("Nothing to expand".to_string()))
     }
 
-    pub fn list_macros(&self) -> Result<Vec<(String, ProcMacroKind)>, bridge::PanicMessage> {
-        let mut result = vec![];
-
-        for lib in &self.libs {
-            for proc_macro in &lib.exported_macros {
-                let res = match proc_macro {
-                    bridge::client::ProcMacro::CustomDerive { trait_name, .. } => {
-                        (trait_name.to_string(), ProcMacroKind::CustomDerive)
-                    }
-                    bridge::client::ProcMacro::Bang { name, .. } => {
-                        (name.to_string(), ProcMacroKind::FuncLike)
-                    }
-                    bridge::client::ProcMacro::Attr { name, .. } => {
-                        (name.to_string(), ProcMacroKind::Attr)
-                    }
-                };
-                result.push(res);
-            }
-        }
-
-        Ok(result)
+    pub fn list_macros(&self) -> Vec<(String, ProcMacroKind)> {
+        self.libs
+            .iter()
+            .flat_map(|it| &it.exported_macros)
+            .map(|proc_macro| match proc_macro {
+                bridge::client::ProcMacro::CustomDerive { trait_name, .. } => {
+                    (trait_name.to_string(), ProcMacroKind::CustomDerive)
+                }
+                bridge::client::ProcMacro::Bang { name, .. } => {
+                    (name.to_string(), ProcMacroKind::FuncLike)
+                }
+                bridge::client::ProcMacro::Attr { name, .. } => {
+                    (name.to_string(), ProcMacroKind::Attr)
+                }
+            })
+            .collect()
     }
 }

crates/ra_proc_macro_srv/src/lib.rs

@@ -3,10 +3,10 @@
 //! 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:
+//! But we adapt it to better fit 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.
+//! * We use `ra_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 gerenal ABI compatibility is still an issue)
 
@@ -21,36 +21,28 @@ mod dylib;
 
 use proc_macro::bridge::client::TokenStream;
 use ra_proc_macro::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTask};
+use std::path::Path;
 
 pub(crate) fn expand_task(task: &ExpansionTask) -> Result<ExpansionResult, String> {
-    let expander = dylib::Expander::new(&task.lib)
-        .expect(&format!("Cannot expand with provided libraries: ${:?}", &task.lib));
+    let expander = create_expander(&task.lib);
 
     match expander.expand(&task.macro_name, &task.macro_body, task.attributes.as_ref()) {
         Ok(expansion) => Ok(ExpansionResult { expansion }),
         Err(msg) => {
-            let reason = format!(
-                "Cannot perform expansion for {}: error {:?}!",
-                &task.macro_name,
-                msg.as_str()
-            );
-            Err(reason)
+            Err(format!("Cannot perform expansion for {}: error {:?}", &task.macro_name, msg))
         }
     }
 }
 
-pub(crate) fn list_macros(task: &ListMacrosTask) -> Result<ListMacrosResult, String> {
-    let expander = dylib::Expander::new(&task.lib)
-        .expect(&format!("Cannot expand with provided libraries: ${:?}", &task.lib));
+pub(crate) fn list_macros(task: &ListMacrosTask) -> ListMacrosResult {
+    let expander = create_expander(&task.lib);
 
-    match expander.list_macros() {
-        Ok(macros) => Ok(ListMacrosResult { macros }),
-        Err(msg) => {
-            let reason =
-                format!("Cannot perform expansion for {:?}: error {:?}!", &task.lib, msg.as_str());
-            Err(reason)
-        }
-    }
+    ListMacrosResult { macros: expander.list_macros() }
+}
+
+fn create_expander(lib: &Path) -> dylib::Expander {
+    dylib::Expander::new(lib)
+        .unwrap_or_else(|err| panic!("Cannot create expander for {}: {:?}", lib.display(), err))
 }
 
 pub mod cli;

crates/ra_proc_macro_srv/src/rustc_server.rs

@@ -6,7 +6,7 @@
 //! The original idea from fedochet is using proc-macro2 as backend,
 //! we use ra_tt instead for better intergation with RA.
 //!
-//! FIXME: No span and source file informatin is implemented yet
+//! FIXME: No span and source file information is implemented yet
 
 use crate::proc_macro::bridge::{self, server};
 use ra_tt as tt;

crates/ra_proc_macro_srv/src/tests/utils.rs

@@ -60,6 +60,6 @@ pub fn list(crate_name: &str, version: &str) -> Vec<String> {
     let path = fixtures::dylib_path(crate_name, version);
     let task = ListMacrosTask { lib: path };
 
-    let res = list_macros(&task).unwrap();
+    let res = list_macros(&task);
     res.macros.into_iter().map(|(name, kind)| format!("{} [{:?}]", name, kind)).collect()
 }

crates/rust-analyzer/src/bin/main.rs

@@ -51,7 +51,7 @@ fn main() -> Result<()> {
             cli::diagnostics(path.as_ref(), load_output_dirs, with_proc_macro, all)?
         }
 
-        args::Command::ProcMacro => run_proc_macro_sv()?,
+        args::Command::ProcMacro => run_proc_macro_srv()?,
         args::Command::RunServer => run_server()?,
         args::Command::Version => println!("rust-analyzer {}", env!("REV")),
     }
@@ -65,7 +65,7 @@ fn setup_logging() -> Result<()> {
     Ok(())
 }
 
-fn run_proc_macro_sv() -> Result<()> {
+fn run_proc_macro_srv() -> Result<()> {
     ra_proc_macro_srv::cli::run();
     Ok(())
 }

crates/rust-analyzer/src/cli/load_cargo.rs

@@ -76,7 +76,7 @@ pub(crate) fn load_cargo(
         ProcMacroClient::dummy()
     } else {
         let path = std::env::current_exe()?;
-        ProcMacroClient::extern_process(&path, &["proc-macro"]).unwrap()
+        ProcMacroClient::extern_process(path, &["proc-macro"]).unwrap()
     };
     let host = load(&source_roots, ws, &mut vfs, receiver, extern_dirs, &proc_macro_client);
     Ok((host, source_roots))

crates/rust-analyzer/src/world.rs

@@ -148,20 +148,17 @@ impl WorldState {
 
         let proc_macro_client = match &config.proc_macro_srv {
             None => ProcMacroClient::dummy(),
-            Some((path, args)) => {
-                let path = std::path::Path::new(path);
-                match ProcMacroClient::extern_process(path, args) {
-                    Ok(it) => it,
-                    Err(err) => {
-                        log::error!(
-                            "Fail to run ra_proc_macro_srv from path {}, error : {}",
-                            path.to_string_lossy(),
-                            err
-                        );
-                        ProcMacroClient::dummy()
-                    }
+            Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
+                Ok(it) => it,
+                Err(err) => {
+                    log::error!(
+                        "Fail to run ra_proc_macro_srv from path {}, error: {:?}",
+                        path,
+                        err
+                    );
+                    ProcMacroClient::dummy()
                 }
-            }
+            },
         };
 
         workspaces