3 files changed, 54 insertions, 102 deletions

diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index eb9f33ee8..a306ce95f 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -11,7 +11,6 @@ use anyhow::{Context, Result};
 use cargo_metadata::{BuildScript, CargoOpt, Message, MetadataCommand, PackageId};
 use ra_arena::{Arena, Idx};
 use ra_db::Edition;
-use ra_env::get_path_for_executable;
 use rustc_hash::FxHashMap;
 
 /// `CargoWorkspace` represents the logical structure of, well, a Cargo
@@ -147,7 +146,7 @@ impl CargoWorkspace {
         cargo_features: &CargoConfig,
     ) -> Result<CargoWorkspace> {
         let mut meta = MetadataCommand::new();
-        meta.cargo_path(get_path_for_executable("cargo")?);
+        meta.cargo_path(ra_toolchain::cargo());
         meta.manifest_path(cargo_toml);
         if cargo_features.all_features {
             meta.features(CargoOpt::AllFeatures);
@@ -162,7 +161,7 @@ impl CargoWorkspace {
             meta.current_dir(parent);
         }
         if let Some(target) = cargo_features.target.as_ref() {
-            meta.other_options(&[String::from("--filter-platform"), target.clone()]);
+            meta.other_options(vec![String::from("--filter-platform"), target.clone()]);
         }
         let meta = meta.exec().with_context(|| {
             format!("Failed to run `cargo metadata --manifest-path {}`", cargo_toml.display())
@@ -289,7 +288,7 @@ pub fn load_extern_resources(
     cargo_toml: &Path,
     cargo_features: &CargoConfig,
 ) -> Result<ExternResources> {
-    let mut cmd = Command::new(get_path_for_executable("cargo")?);
+    let mut cmd = Command::new(ra_toolchain::cargo());
     cmd.args(&["check", "--message-format=json", "--manifest-path"]).arg(cargo_toml);
     if cargo_features.all_features {
         cmd.arg("--all-features");
@@ -305,19 +304,13 @@ pub fn load_extern_resources(
 
     let mut res = ExternResources::default();
 
-    for message in cargo_metadata::parse_messages(output.stdout.as_slice()) {
+    for message in cargo_metadata::Message::parse_stream(output.stdout.as_slice()) {
         if let Ok(message) = message {
             match message {
                 Message::BuildScriptExecuted(BuildScript { package_id, out_dir, cfgs, .. }) => {
                     res.out_dirs.insert(package_id.clone(), out_dir);
-                    res.cfgs.insert(
-                        package_id,
-                        // FIXME: Current `cargo_metadata` uses `PathBuf` instead of `String`,
-                        // change when https://github.com/oli-obk/cargo_metadata/pulls/112 reaches crates.io
-                        cfgs.iter().filter_map(|c| c.to_str().map(|s| s.to_owned())).collect(),
-                    );
+                    res.cfgs.insert(package_id, cfgs);
                 }
-
                 Message::CompilerArtifact(message) => {
                     if message.target.kind.contains(&"proc-macro".to_string()) {
                         let package_id = message.package_id;
@@ -330,6 +323,8 @@ pub fn load_extern_resources(
                 }
                 Message::CompilerMessage(_) => (),
                 Message::Unknown => (),
+                Message::BuildFinished(_) => {}
+                Message::TextLine(_) => {}
             }
         }
     }
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 88a6ffb2a..4f098b706 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -8,13 +8,12 @@ use std::{
     fs::{read_dir, File, ReadDir},
     io::{self, BufReader},
     path::{Path, PathBuf},
-    process::Command,
+    process::{Command, Output},
 };
 
 use anyhow::{bail, Context, Result};
 use ra_cfg::CfgOptions;
 use ra_db::{CrateGraph, CrateName, Edition, Env, ExternSource, ExternSourceId, FileId};
-use ra_env::get_path_for_executable;
 use rustc_hash::FxHashMap;
 use serde_json::from_reader;
 
@@ -89,46 +88,28 @@ impl ProjectRoot {
     }
 
     pub fn discover(path: &Path) -> io::Result<Vec<ProjectRoot>> {
-        if let Some(project_json) = find_rust_project_json(path) {
+        if let Some(project_json) = find_in_parent_dirs(path, "rust-project.json") {
             return Ok(vec![ProjectRoot::ProjectJson(project_json)]);
         }
         return find_cargo_toml(path)
             .map(|paths| paths.into_iter().map(ProjectRoot::CargoToml).collect());
 
-        fn find_rust_project_json(path: &Path) -> Option<PathBuf> {
-            if path.ends_with("rust-project.json") {
-                return Some(path.to_path_buf());
-            }
-
-            let mut curr = Some(path);
-            while let Some(path) = curr {
-                let candidate = path.join("rust-project.json");
-                if candidate.exists() {
-                    return Some(candidate);
-                }
-                curr = path.parent();
-            }
-
-            None
-        }
-
         fn find_cargo_toml(path: &Path) -> io::Result<Vec<PathBuf>> {
-            if path.ends_with("Cargo.toml") {
-                return Ok(vec![path.to_path_buf()]);
+            match find_in_parent_dirs(path, "Cargo.toml") {
+                Some(it) => Ok(vec![it]),
+                None => Ok(find_cargo_toml_in_child_dir(read_dir(path)?)),
             }
+        }
 
-            if let Some(p) = find_cargo_toml_in_parent_dir(path) {
-                return Ok(vec![p]);
+        fn find_in_parent_dirs(path: &Path, target_file_name: &str) -> Option<PathBuf> {
+            if path.ends_with(target_file_name) {
+                return Some(path.to_owned());
             }
 
-            let entities = read_dir(path)?;
-            Ok(find_cargo_toml_in_child_dir(entities))
-        }
-
-        fn find_cargo_toml_in_parent_dir(path: &Path) -> Option<PathBuf> {
             let mut curr = Some(path);
+
             while let Some(path) = curr {
-                let candidate = path.join("Cargo.toml");
+                let candidate = path.join(target_file_name);
                 if candidate.exists() {
                     return Some(candidate);
                 }
@@ -140,14 +121,11 @@ impl ProjectRoot {
 
         fn find_cargo_toml_in_child_dir(entities: ReadDir) -> Vec<PathBuf> {
             // Only one level down to avoid cycles the easy way and stop a runaway scan with large projects
-            let mut valid_canditates = vec![];
-            for entity in entities.filter_map(Result::ok) {
-                let candidate = entity.path().join("Cargo.toml");
-                if candidate.exists() {
-                    valid_canditates.push(candidate)
-                }
-            }
-            valid_canditates
+            entities
+                .filter_map(Result::ok)
+                .map(|it| it.path().join("Cargo.toml"))
+                .filter(|it| it.exists())
+                .collect()
         }
     }
 }
@@ -568,25 +546,18 @@ pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
         }
     }
 
-    match (|| -> Result<String> {
+    let rustc_cfgs = || -> Result<String> {
         // `cfg(test)` and `cfg(debug_assertion)` are handled outside, so we suppress them here.
-        let mut cmd = Command::new(get_path_for_executable("rustc")?);
+        let mut cmd = Command::new(ra_toolchain::rustc());
         cmd.args(&["--print", "cfg", "-O"]);
         if let Some(target) = target {
             cmd.args(&["--target", target.as_str()]);
         }
-        let output = cmd.output().context("Failed to get output from rustc --print cfg -O")?;
-        if !output.status.success() {
-            bail!(
-                "rustc --print cfg -O exited with exit code ({})",
-                output
-                    .status
-                    .code()
-                    .map_or(String::from("no exit code"), |code| format!("{}", code))
-            );
-        }
+        let output = output(cmd)?;
         Ok(String::from_utf8(output.stdout)?)
-    })() {
+    }();
+
+    match rustc_cfgs {
         Ok(rustc_cfgs) => {
             for line in rustc_cfgs.lines() {
                 match line.find('=') {
@@ -599,8 +570,21 @@ pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
                 }
             }
         }
-        Err(e) => log::error!("failed to get rustc cfgs: {}", e),
+        Err(e) => log::error!("failed to get rustc cfgs: {:#}", e),
     }
 
     cfg_options
 }
+
+fn output(mut cmd: Command) -> Result<Output> {
+    let output = cmd.output().with_context(|| format!("{:?} failed", cmd))?;
+    if !output.status.success() {
+        match String::from_utf8(output.stderr) {
+            Ok(stderr) if !stderr.is_empty() => {
+                bail!("{:?} failed, {}\nstderr:\n{}", cmd, output.status, stderr)
+            }
+            _ => bail!("{:?} failed, {}", cmd, output.status),
+        }
+    }
+    Ok(output)
+}
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index 11c26ad89..a8a196e64 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -1,14 +1,15 @@
 //! FIXME: write short doc here
 
-use anyhow::{bail, Context, Result};
 use std::{
     env, ops,
     path::{Path, PathBuf},
-    process::{Command, Output},
+    process::Command,
 };
 
+use anyhow::{bail, Result};
 use ra_arena::{Arena, Idx};
-use ra_env::get_path_for_executable;
+
+use crate::output;
 
 #[derive(Default, Debug, Clone)]
 pub struct Sysroot {
@@ -85,50 +86,22 @@ impl Sysroot {
     }
 }
 
-fn create_command_text(program: &str, args: &[&str]) -> String {
-    format!("{} {}", program, args.join(" "))
-}
-
-fn run_command_in_cargo_dir(
-    cargo_toml: impl AsRef<Path>,
-    program: impl AsRef<Path>,
-    args: &[&str],
-) -> Result<Output> {
-    let program = program.as_ref().as_os_str().to_str().expect("Invalid Unicode in path");
-    let output = Command::new(program)
-        .current_dir(cargo_toml.as_ref().parent().unwrap())
-        .args(args)
-        .output()
-        .context(format!("{} failed", create_command_text(program, args)))?;
-    if !output.status.success() {
-        match output.status.code() {
-            Some(code) => bail!(
-                "failed to run the command: '{}' exited with code {}",
-                create_command_text(program, args),
-                code
-            ),
-            None => bail!(
-                "failed to run the command: '{}' terminated by signal",
-                create_command_text(program, args)
-            ),
-        };
-    }
-    Ok(output)
-}
-
 fn get_or_install_rust_src(cargo_toml: &Path) -> Result<PathBuf> {
     if let Ok(path) = env::var("RUST_SRC_PATH") {
         return Ok(path.into());
     }
-    let rustc = get_path_for_executable("rustc")?;
-    let rustc_output = run_command_in_cargo_dir(cargo_toml, &rustc, &["--print", "sysroot"])?;
+    let current_dir = cargo_toml.parent().unwrap();
+    let mut rustc = Command::new(ra_toolchain::rustc());
+    rustc.current_dir(current_dir).args(&["--print", "sysroot"]);
+    let rustc_output = output(rustc)?;
     let stdout = String::from_utf8(rustc_output.stdout)?;
     let sysroot_path = Path::new(stdout.trim());
     let src_path = sysroot_path.join("lib/rustlib/src/rust/src");
 
     if !src_path.exists() {
-        let rustup = get_path_for_executable("rustup")?;
-        run_command_in_cargo_dir(cargo_toml, &rustup, &["component", "add", "rust-src"])?;
+        let mut rustup = Command::new(ra_toolchain::rustup());
+        rustup.current_dir(current_dir).args(&["component", "add", "rust-src"]);
+        let _output = output(rustup)?;
     }
     if !src_path.exists() {
         bail!(