Update OUT_DIR based on cargo check output

crates/ra_cargo_watch/src/lib.rs

@@ -9,8 +9,8 @@ use lsp_types::{
 };
 use std::{
     io::{BufRead, BufReader},
-    path::PathBuf,
-    process::{Command, Stdio},
+    path::{Path, PathBuf},
+    process::{Child, Command, Stdio},
     thread::JoinHandle,
     time::Instant,
 };
@@ -246,102 +246,119 @@ enum CheckEvent {
     End,
 }
 
+pub fn run_cargo(
+    args: &[String],
+    current_dir: Option<&Path>,
+    on_message: &mut dyn FnMut(cargo_metadata::Message) -> bool,
+) -> Child {
+    let mut command = Command::new("cargo");
+    if let Some(current_dir) = current_dir {
+        command.current_dir(current_dir);
+    }
+
+    let mut child = command
+        .args(args)
+        .stdout(Stdio::piped())
+        .stderr(Stdio::null())
+        .stdin(Stdio::null())
+        .spawn()
+        .expect("couldn't launch cargo");
+
+    // We manually read a line at a time, instead of using serde's
+    // stream deserializers, because the deserializer cannot recover
+    // from an error, resulting in it getting stuck, because we try to
+    // be resillient against failures.
+    //
+    // Because cargo only outputs one JSON object per line, we can
+    // simply skip a line if it doesn't parse, which just ignores any
+    // erroneus output.
+    let stdout = BufReader::new(child.stdout.take().unwrap());
+    for line in stdout.lines() {
+        let line = match line {
+            Ok(line) => line,
+            Err(err) => {
+                log::error!("Couldn't read line from cargo: {}", err);
+                continue;
+            }
+        };
+
+        let message = serde_json::from_str::<cargo_metadata::Message>(&line);
+        let message = match message {
+            Ok(message) => message,
+            Err(err) => {
+                log::error!("Invalid json from cargo check, ignoring ({}): {:?} ", err, line);
+                continue;
+            }
+        };
+
+        if !on_message(message) {
+            break;
+        }
+    }
+
+    child
+}
+
 impl WatchThread {
     fn dummy() -> WatchThread {
         WatchThread { handle: None, message_recv: never() }
     }
 
-    fn new(options: &CheckOptions, workspace_root: &PathBuf) -> WatchThread {
+    fn new(options: &CheckOptions, workspace_root: &Path) -> WatchThread {
         let mut args: Vec<String> = vec![
             options.command.clone(),
             "--workspace".to_string(),
             "--message-format=json".to_string(),
             "--manifest-path".to_string(),
-            format!("{}/Cargo.toml", workspace_root.to_string_lossy()),
+            format!("{}/Cargo.toml", workspace_root.display()),
         ];
         if options.all_targets {
             args.push("--all-targets".to_string());
         }
         args.extend(options.args.iter().cloned());
 
         let (message_send, message_recv) = unbounded();
-        let enabled = options.enable;
-        let handle = std::thread::spawn(move || {
-            if !enabled {
-                return;
-            }
-
-            let mut command = Command::new("cargo")
-                .args(&args)
-                .stdout(Stdio::piped())
-                .stderr(Stdio::null())
-                .stdin(Stdio::null())
-                .spawn()
-                .expect("couldn't launch cargo");
-
-            // If we trigger an error here, we will do so in the loop instead,
-            // which will break out of the loop, and continue the shutdown
-            let _ = message_send.send(CheckEvent::Begin);
-
-            // We manually read a line at a time, instead of using serde's
-            // stream deserializers, because the deserializer cannot recover
-            // from an error, resulting in it getting stuck, because we try to
-            // be resillient against failures.
-            //
-            // Because cargo only outputs one JSON object per line, we can
-            // simply skip a line if it doesn't parse, which just ignores any
-            // erroneus output.
-            let stdout = BufReader::new(command.stdout.take().unwrap());
-            for line in stdout.lines() {
-                let line = match line {
-                    Ok(line) => line,
-                    Err(err) => {
-                        log::error!("Couldn't read line from cargo: {}", err);
-                        continue;
-                    }
-                };
-
-                let message = serde_json::from_str::<cargo_metadata::Message>(&line);
-                let message = match message {
-                    Ok(message) => message,
-                    Err(err) => {
-                        log::error!(
-                            "Invalid json from cargo check, ignoring ({}): {:?} ",
-                            err,
-                            line
-                        );
-                        continue;
+        let workspace_root = workspace_root.to_owned();
+        let handle = if options.enable {
+            Some(std::thread::spawn(move || {
+                // If we trigger an error here, we will do so in the loop instead,
+                // which will break out of the loop, and continue the shutdown
+                let _ = message_send.send(CheckEvent::Begin);
+
+                let mut child = run_cargo(&args, Some(&workspace_root), &mut |message| {
+                    // Skip certain kinds of messages to only spend time on what's useful
+                    match &message {
+                        Message::CompilerArtifact(artifact) if artifact.fresh => return true,
+                        Message::BuildScriptExecuted(_) => return true,
+                        Message::Unknown => return true,
+                        _ => {}
                     }
-                };
-
-                // Skip certain kinds of messages to only spend time on what's useful
-                match &message {
-                    Message::CompilerArtifact(artifact) if artifact.fresh => continue,
-                    Message::BuildScriptExecuted(_) => continue,
-                    Message::Unknown => continue,
-                    _ => {}
-                }
 
-                match message_send.send(CheckEvent::Msg(message)) {
-                    Ok(()) => {}
-                    Err(_err) => {
-                        // The send channel was closed, so we want to shutdown
-                        break;
-                    }
-                }
-            }
-
-            // We can ignore any error here, as we are already in the progress
-            // of shutting down.
-            let _ = message_send.send(CheckEvent::End);
-
-            // It is okay to ignore the result, as it only errors if the process is already dead
-            let _ = command.kill();
-
-            // Again, we don't care about the exit status so just ignore the result
-            let _ = command.wait();
-        });
-        WatchThread { handle: Some(handle), message_recv }
+                    match message_send.send(CheckEvent::Msg(message)) {
+                        Ok(()) => {}
+                        Err(_err) => {
+                            // The send channel was closed, so we want to shutdown
+                            return false;
+                        }
+                    };
+
+                    true
+                });
+
+                // We can ignore any error here, as we are already in the progress
+                // of shutting down.
+                let _ = message_send.send(CheckEvent::End);
+
+                // It is okay to ignore the result, as it only errors if the process is already dead
+                let _ = child.kill();
+
+                // Again, we don't care about the exit status so just ignore the result
+                let _ = child.wait();
+            }))
+        } else {
+            None
+        };
+        WatchThread { handle, message_recv }
     }
 }
 

crates/ra_db/src/input.rs

@@ -6,7 +6,11 @@
 //! actual IO. See `vfs` and `project_model` in the `rust-analyzer` crate for how
 //! actual IO is done and lowered to input.
 
-use std::{fmt, ops, str::FromStr};
+use std::{
+    fmt, ops,
+    path::{Path, PathBuf},
+    str::FromStr,
+};
 
 use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
@@ -144,7 +148,7 @@ pub struct Env {
 // crate. We store a map to allow remap it to ExternSourceId
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct ExternSource {
-    extern_paths: FxHashMap<String, ExternSourceId>,
+    extern_paths: FxHashMap<PathBuf, ExternSourceId>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -294,13 +298,10 @@ impl Env {
 }
 
 impl ExternSource {
-    pub fn extern_path(&self, path: &str) -> Option<(ExternSourceId, RelativePathBuf)> {
+    pub fn extern_path(&self, path: impl AsRef<Path>) -> Option<(ExternSourceId, RelativePathBuf)> {
+        let path = path.as_ref();
         self.extern_paths.iter().find_map(|(root_path, id)| {
-            if path.starts_with(root_path) {
-                let mut rel_path = &path[root_path.len()..];
-                if rel_path.starts_with("/") {
-                    rel_path = &rel_path[1..];
-                }
+            if let Ok(rel_path) = path.strip_prefix(root_path) {
                 let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
                 Some((id.clone(), rel_path))
             } else {
@@ -309,8 +310,8 @@ impl ExternSource {
         })
     }
 
-    pub fn set_extern_path(&mut self, root_path: &str, root: ExternSourceId) {
-        self.extern_paths.insert(root_path.to_owned(), root);
+    pub fn set_extern_path(&mut self, root_path: &Path, root: ExternSourceId) {
+        self.extern_paths.insert(root_path.to_path_buf(), root);
     }
 }
 

crates/ra_project_model/Cargo.toml

@@ -16,6 +16,7 @@ cargo_metadata = "0.9.1"
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
 ra_cfg = { path = "../ra_cfg" }
+ra_cargo_watch = { path = "../ra_cargo_watch" }
 
 serde = { version = "1.0.104", features = ["derive"] }
 serde_json = "1.0.48"

crates/ra_project_model/src/cargo_workspace.rs

@@ -3,8 +3,9 @@
 use std::path::{Path, PathBuf};
 
 use anyhow::{Context, Result};
-use cargo_metadata::{CargoOpt, MetadataCommand};
+use cargo_metadata::{CargoOpt, Message, MetadataCommand, PackageId};
 use ra_arena::{impl_arena_id, Arena, RawId};
+use ra_cargo_watch::run_cargo;
 use ra_db::Edition;
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
@@ -35,11 +36,19 @@ pub struct CargoFeatures {
     /// List of features to activate.
     /// This will be ignored if `cargo_all_features` is true.
     pub features: Vec<String>,
+
+    /// Runs cargo check on launch to figure out the correct values of OUT_DIR
+    pub load_out_dirs_from_check: bool,
 }
 
 impl Default for CargoFeatures {
     fn default() -> Self {
-        CargoFeatures { no_default_features: false, all_features: true, features: Vec::new() }
+        CargoFeatures {
+            no_default_features: false,
+            all_features: true,
+            features: Vec::new(),
+            load_out_dirs_from_check: false,
+        }
     }
 }
 
@@ -60,6 +69,7 @@ struct PackageData {
     dependencies: Vec<PackageDependency>,
     edition: Edition,
     features: Vec<String>,
+    out_dir: Option<PathBuf>,
 }
 
 #[derive(Debug, Clone)]
@@ -131,6 +141,9 @@ impl Package {
     ) -> impl Iterator<Item = &'a PackageDependency> + 'a {
         ws.packages[self].dependencies.iter()
     }
+    pub fn out_dir(self, ws: &CargoWorkspace) -> Option<&Path> {
+        ws.packages[self].out_dir.as_ref().map(PathBuf::as_path)
+    }
 }
 
 impl Target {
@@ -173,6 +186,12 @@ impl CargoWorkspace {
         let meta = meta.exec().with_context(|| {
             format!("Failed to run `cargo metadata --manifest-path {}`", cargo_toml.display())
         })?;
+
+        let mut out_dir_by_id = FxHashMap::default();
+        if cargo_features.load_out_dirs_from_check {
+            out_dir_by_id = load_out_dirs(cargo_toml, cargo_features);
+        }
+
         let mut pkg_by_id = FxHashMap::default();
         let mut packages = Arena::default();
         let mut targets = Arena::default();
@@ -193,6 +212,7 @@ impl CargoWorkspace {
                 edition,
                 dependencies: Vec::new(),
                 features: Vec::new(),
+                out_dir: out_dir_by_id.get(&id).cloned(),
             });
             let pkg_data = &mut packages[pkg];
             pkg_by_id.insert(id, pkg);
@@ -252,3 +272,46 @@ impl CargoWorkspace {
         &self.workspace_root
     }
 }
+
+pub fn load_out_dirs(
+    cargo_toml: &Path,
+    cargo_features: &CargoFeatures,
+) -> FxHashMap<PackageId, PathBuf> {
+    let mut args: Vec<String> = vec![
+        "check".to_string(),
+        "--message-format=json".to_string(),
+        "--manifest-path".to_string(),
+        format!("{}", cargo_toml.display()),
+    ];
+
+    if cargo_features.all_features {
+        args.push("--all-features".to_string());
+    } else if cargo_features.no_default_features {
+        // FIXME: `NoDefaultFeatures` is mutual exclusive with `SomeFeatures`
+        // https://github.com/oli-obk/cargo_metadata/issues/79
+        args.push("--no-default-features".to_string());
+    } else if !cargo_features.features.is_empty() {
+        for feature in &cargo_features.features {
+            args.push(feature.clone());
+        }
+    }
+
+    let mut res = FxHashMap::default();
+    let mut child = run_cargo(&args, cargo_toml.parent(), &mut |message| {
+        match message {
+            Message::BuildScriptExecuted(message) => {
+                let package_id = message.package_id;
+                let out_dir = message.out_dir;
+                res.insert(package_id, out_dir);
+            }
+
+            Message::CompilerArtifact(_) => (),
+            Message::CompilerMessage(_) => (),
+            Message::Unknown => (),
+        }
+        true
+    });
+
+    let _ = child.wait();
+    res
+}

crates/ra_project_model/src/json_project.rs

@@ -22,6 +22,7 @@ pub struct Crate {
     pub(crate) deps: Vec<Dep>,
     pub(crate) atom_cfgs: FxHashSet<String>,
     pub(crate) key_value_cfgs: FxHashMap<String, String>,
+    pub(crate) out_dir: Option<PathBuf>,
 }
 
 #[derive(Clone, Copy, Debug, Deserialize)]