Show workspace info in the status bar

crates/project-model/src/project_json.rs

@@ -56,6 +56,7 @@ use serde::{de, Deserialize, Serialize};
 use span::Edition;
 
 use crate::cfg::CfgFlag;
+use crate::ManifestPath;
 
 /// Roots and crates that compose this Rust project.
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -65,6 +66,7 @@ pub struct ProjectJson {
     /// e.g. `path/to/sysroot/lib/rustlib/src/rust`
     pub(crate) sysroot_src: Option<AbsPathBuf>,
     project_root: AbsPathBuf,
+    manifest: Option<ManifestPath>,
     crates: Vec<Crate>,
 }
 
@@ -96,12 +98,17 @@ impl ProjectJson {
     /// * `base` - The path to the workspace root (i.e. the folder containing `rust-project.json`)
     /// * `data` - The parsed contents of `rust-project.json`, or project json that's passed via
     ///            configuration.
-    pub fn new(base: &AbsPath, data: ProjectJsonData) -> ProjectJson {
+    pub fn new(
+        manifest: Option<ManifestPath>,
+        base: &AbsPath,
+        data: ProjectJsonData,
+    ) -> ProjectJson {
         let absolutize_on_base = |p| base.absolutize(p);
         ProjectJson {
             sysroot: data.sysroot.map(absolutize_on_base),
             sysroot_src: data.sysroot_src.map(absolutize_on_base),
             project_root: base.to_path_buf(),
+            manifest,
             crates: data
                 .crates
                 .into_iter()
@@ -159,6 +166,11 @@ impl ProjectJson {
     pub fn path(&self) -> &AbsPath {
         &self.project_root
     }
+
+    /// Returns the path to the project's manifest or root folder, if no manifest exists.
+    pub fn manifest_or_root(&self) -> &AbsPath {
+        self.manifest.as_ref().map_or(&self.project_root, |manifest| manifest.as_ref())
+    }
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]

crates/project-model/src/sysroot.rs

@@ -133,6 +133,24 @@ impl Sysroot {
         }
     }
 
+    pub fn check_has_core(&self) -> Result<(), String> {
+        let Some(Ok(src_root)) = &self.src_root else { return Ok(()) };
+        let has_core = match &self.mode {
+            SysrootMode::Workspace(ws) => ws.packages().any(|p| ws[p].name == "core"),
+            SysrootMode::Stitched(stitched) => stitched.by_name("core").is_some(),
+        };
+        if !has_core {
+            let var_note = if env::var_os("RUST_SRC_PATH").is_some() {
+                " (`RUST_SRC_PATH` might be incorrect, try unsetting it)"
+            } else {
+                " try running `rustup component add rust-src` to possible fix this"
+            };
+            Err(format!("could not find libcore in loaded sysroot at `{}`{var_note}", src_root,))
+        } else {
+            Ok(())
+        }
+    }
+
     pub fn num_packages(&self) -> usize {
         match &self.mode {
             SysrootMode::Workspace(ws) => ws.packages().count(),

crates/project-model/src/tests.rs

@@ -152,7 +152,7 @@ fn rooted_project_json(data: ProjectJsonData) -> ProjectJson {
     replace_root(&mut root, true);
     let path = Utf8Path::new(&root);
     let base = AbsPath::assert(path);
-    ProjectJson::new(base, data)
+    ProjectJson::new(None, base, data)
 }
 
 fn to_crate_graph(project_workspace: ProjectWorkspace) -> (CrateGraph, ProcMacroPaths) {

crates/project-model/src/workspace.rs

@@ -199,7 +199,8 @@ impl ProjectWorkspace {
                 let data = serde_json::from_str(&file)
                     .with_context(|| format!("Failed to deserialize json file {project_json}"))?;
                 let project_location = project_json.parent().to_path_buf();
-                let project_json: ProjectJson = ProjectJson::new(&project_location, data);
+                let project_json: ProjectJson =
+                    ProjectJson::new(Some(project_json.clone()), &project_location, data);
                 ProjectWorkspace::load_inline(
                     project_json,
                     config.target.as_deref(),
@@ -555,7 +556,7 @@ impl ProjectWorkspace {
     pub fn manifest_or_root(&self) -> &AbsPath {
         match &self.kind {
             ProjectWorkspaceKind::Cargo { cargo, .. } => cargo.manifest_path(),
-            ProjectWorkspaceKind::Json(project) => project.path(),
+            ProjectWorkspaceKind::Json(project) => project.manifest_or_root(),
             ProjectWorkspaceKind::DetachedFile { file, .. } => file,
         }
     }