From a2ed6837bc45f13ecd72553dd0aaa16dc7d5dd87 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Sun, 21 Apr 2024 14:40:10 +0200
Subject: [PATCH] Allow rust files to be used linkedProjects

---
 crates/base-db/src/lib.rs                     |   2 +
 crates/hir/src/semantics/source_to_def.rs     |   5 +-
 crates/ide-db/src/prime_caches.rs             |   2 +-
 crates/project-model/src/build_scripts.rs     |  53 ++----
 crates/project-model/src/cargo_workspace.rs   |   9 +-
 crates/project-model/src/lib.rs               |  21 ++-
 crates/project-model/src/manifest_path.rs     |  12 +-
 crates/project-model/src/sysroot.rs           |   6 +-
 crates/project-model/src/tests.rs             |  24 ++-
 crates/project-model/src/workspace.rs         | 177 +++++++++---------
 .../rust-analyzer/src/cli/progress_report.rs  |   2 +-
 crates/rust-analyzer/src/cli/rustc_tests.rs   |   6 +-
 crates/rust-analyzer/src/config.rs            |  12 +-
 crates/rust-analyzer/src/global_state.rs      |   6 +-
 crates/rust-analyzer/src/handlers/request.rs  |   9 +-
 crates/rust-analyzer/src/reload.rs            |  11 +-
 crates/rust-analyzer/tests/crate_graph.rs     |  10 +-
 crates/rust-analyzer/tests/slow-tests/main.rs |   1 +
 .../rust-analyzer/tests/slow-tests/support.rs |   6 +-
 docs/user/generated_config.adoc               |   3 +-
 editors/code/package.json                     |   2 +-
 21 files changed, 201 insertions(+), 178 deletions(-)

diff --git a/crates/base-db/src/lib.rs b/crates/base-db/src/lib.rs
index 2b64a07a5a95..82aff6e3b8e3 100644
--- a/crates/base-db/src/lib.rs
+++ b/crates/base-db/src/lib.rs
@@ -51,6 +51,7 @@ pub trait FileLoader {
     /// Text of the file.
     fn file_text(&self, file_id: FileId) -> Arc<str>;
     fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId>;
+    /// Crates whose root's source root is the same as the source root of `file_id`
     fn relevant_crates(&self, file_id: FileId) -> Arc<[CrateId]>;
 }
 
@@ -104,6 +105,7 @@ pub trait SourceDatabaseExt: SourceDatabase {
     #[salsa::input]
     fn source_root(&self, id: SourceRootId) -> Arc<SourceRoot>;
 
+    /// Crates whose root fool is in `id`.
     fn source_root_crates(&self, id: SourceRootId) -> Arc<[CrateId]>;
 }
 
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index 434e4b5a0cf1..007709a836ed 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -121,7 +121,7 @@ impl SourceToDefCtx<'_, '_> {
         let _p = tracing::span!(tracing::Level::INFO, "SourceBinder::file_to_module_def").entered();
         let mut mods = SmallVec::new();
         for &crate_id in self.db.relevant_crates(file).iter() {
-            // FIXME: inner items
+            // Note: `mod` declarations in block modules cannot be supported here
             let crate_def_map = self.db.crate_def_map(crate_id);
             mods.extend(
                 crate_def_map
@@ -129,6 +129,9 @@ impl SourceToDefCtx<'_, '_> {
                     .map(|local_id| crate_def_map.module_id(local_id)),
             )
         }
+        if mods.is_empty() {
+            // FIXME: detached file
+        }
         mods
     }
 
diff --git a/crates/ide-db/src/prime_caches.rs b/crates/ide-db/src/prime_caches.rs
index 024e8f6ae39d..0db87c6bc48f 100644
--- a/crates/ide-db/src/prime_caches.rs
+++ b/crates/ide-db/src/prime_caches.rs
@@ -1,6 +1,6 @@
 //! rust-analyzer is lazy and doesn't compute anything unless asked. This
 //! sometimes is counter productive when, for example, the first goto definition
-//! request takes longer to compute. This modules implemented prepopulation of
+//! request takes longer to compute. This module implements prepopulation of
 //! various caches, it's not really advanced at the moment.
 mod topologic_sort;
 
diff --git a/crates/project-model/src/build_scripts.rs b/crates/project-model/src/build_scripts.rs
index fbd423c9eac8..3fdd59967b17 100644
--- a/crates/project-model/src/build_scripts.rs
+++ b/crates/project-model/src/build_scripts.rs
@@ -24,7 +24,7 @@ use toolchain::Tool;
 
 use crate::{
     cfg::CfgFlag, utf8_stdout, CargoConfig, CargoFeatures, CargoWorkspace, InvocationLocation,
-    InvocationStrategy, Package, Sysroot, TargetKind,
+    InvocationStrategy, ManifestPath, Package, Sysroot, TargetKind,
 };
 
 /// Output of the build script and proc-macro building steps for a workspace.
@@ -63,7 +63,7 @@ impl WorkspaceBuildScripts {
     fn build_command(
         config: &CargoConfig,
         allowed_features: &FxHashSet<String>,
-        workspace_root: &AbsPathBuf,
+        manifest_path: &ManifestPath,
         sysroot: Option<&Sysroot>,
     ) -> io::Result<Command> {
         let mut cmd = match config.run_build_script_command.as_deref() {
@@ -79,7 +79,7 @@ impl WorkspaceBuildScripts {
                 cmd.args(&config.extra_args);
 
                 cmd.arg("--manifest-path");
-                cmd.arg(workspace_root.join("Cargo.toml"));
+                cmd.arg(manifest_path.as_ref());
 
                 if let Some(target_dir) = &config.target_dir {
                     cmd.arg("--target-dir").arg(target_dir);
@@ -116,6 +116,10 @@ impl WorkspaceBuildScripts {
                     }
                 }
 
+                if manifest_path.extension().map_or(false, |ext| ext == "rs") {
+                    cmd.arg("-Zscript");
+                }
+
                 cmd
             }
         };
@@ -152,37 +156,12 @@ impl WorkspaceBuildScripts {
         .as_ref();
 
         let allowed_features = workspace.workspace_features();
-
-        match Self::run_per_ws(
-            Self::build_command(
-                config,
-                &allowed_features,
-                &workspace.workspace_root().to_path_buf(),
-                sysroot,
-            )?,
-            workspace,
-            current_dir,
-            progress,
-        ) {
-            Ok(WorkspaceBuildScripts { error: Some(error), .. })
-                if toolchain.as_ref().map_or(false, |it| *it >= RUST_1_75) =>
-            {
-                // building build scripts failed, attempt to build with --keep-going so
-                // that we potentially get more build data
-                let mut cmd = Self::build_command(
-                    config,
-                    &allowed_features,
-                    &workspace.workspace_root().to_path_buf(),
-                    sysroot,
-                )?;
-
-                cmd.args(["--keep-going"]);
-                let mut res = Self::run_per_ws(cmd, workspace, current_dir, progress)?;
-                res.error = Some(error);
-                Ok(res)
-            }
-            res => res,
+        let mut cmd =
+            Self::build_command(config, &allowed_features, workspace.manifest_path(), sysroot)?;
+        if toolchain.as_ref().map_or(false, |it| *it >= RUST_1_75) {
+            cmd.args(["--keep-going"]);
         }
+        Self::run_per_ws(cmd, workspace, current_dir, progress)
     }
 
     /// Runs the build scripts by invoking the configured command *once*.
@@ -204,7 +183,13 @@ impl WorkspaceBuildScripts {
                 ))
             }
         };
-        let cmd = Self::build_command(config, &Default::default(), workspace_root, None)?;
+        let cmd = Self::build_command(
+            config,
+            &Default::default(),
+            // This is not gonna be used anyways, so just construct a dummy here
+            &ManifestPath::try_from(workspace_root.clone()).unwrap(),
+            None,
+        )?;
         // NB: Cargo.toml could have been modified between `cargo metadata` and
         // `cargo check`. We shouldn't assume that package ids we see here are
         // exactly those from `config`.
diff --git a/crates/project-model/src/cargo_workspace.rs b/crates/project-model/src/cargo_workspace.rs
index ff7cf144aa82..88ba5a0da969 100644
--- a/crates/project-model/src/cargo_workspace.rs
+++ b/crates/project-model/src/cargo_workspace.rs
@@ -32,6 +32,7 @@ pub struct CargoWorkspace {
     targets: Arena<TargetData>,
     workspace_root: AbsPathBuf,
     target_directory: AbsPathBuf,
+    manifest_path: ManifestPath,
 }
 
 impl ops::Index<Package> for CargoWorkspace {
@@ -334,7 +335,7 @@ impl CargoWorkspace {
         .with_context(|| format!("Failed to run `{:?}`", meta.cargo_command()))
     }
 
-    pub fn new(mut meta: cargo_metadata::Metadata) -> CargoWorkspace {
+    pub fn new(mut meta: cargo_metadata::Metadata, manifest_path: ManifestPath) -> CargoWorkspace {
         let mut pkg_by_id = FxHashMap::default();
         let mut packages = Arena::default();
         let mut targets = Arena::default();
@@ -448,7 +449,7 @@ impl CargoWorkspace {
 
         let target_directory = AbsPathBuf::assert(meta.target_directory);
 
-        CargoWorkspace { packages, targets, workspace_root, target_directory }
+        CargoWorkspace { packages, targets, workspace_root, target_directory, manifest_path }
     }
 
     pub fn packages(&self) -> impl ExactSizeIterator<Item = Package> + '_ {
@@ -466,6 +467,10 @@ impl CargoWorkspace {
         &self.workspace_root
     }
 
+    pub fn manifest_path(&self) -> &ManifestPath {
+        &self.manifest_path
+    }
+
     pub fn target_directory(&self) -> &AbsPath {
         &self.target_directory
     }
diff --git a/crates/project-model/src/lib.rs b/crates/project-model/src/lib.rs
index 7f3e35ca5dbc..5428f061b715 100644
--- a/crates/project-model/src/lib.rs
+++ b/crates/project-model/src/lib.rs
@@ -54,11 +54,13 @@ pub use crate::{
     sysroot::Sysroot,
     workspace::{FileLoader, PackageRoot, ProjectWorkspace},
 };
+pub use cargo_metadata::Metadata;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub enum ProjectManifest {
     ProjectJson(ManifestPath),
     CargoToml(ManifestPath),
+    CargoScript(ManifestPath),
 }
 
 impl ProjectManifest {
@@ -71,7 +73,10 @@ impl ProjectManifest {
         if path.file_name().unwrap_or_default() == "Cargo.toml" {
             return Ok(ProjectManifest::CargoToml(path));
         }
-        bail!("project root must point to Cargo.toml or rust-project.json: {path}");
+        if path.extension().unwrap_or_default() == "rs" {
+            return Ok(ProjectManifest::CargoScript(path));
+        }
+        bail!("project root must point to a Cargo.toml, rust-project.json or <script>.rs file: {path}");
     }
 
     pub fn discover_single(path: &AbsPath) -> anyhow::Result<ProjectManifest> {
@@ -146,15 +151,19 @@ impl ProjectManifest {
         res.sort();
         res
     }
+
+    pub fn manifest_path(&self) -> &ManifestPath {
+        match self {
+            ProjectManifest::ProjectJson(it)
+            | ProjectManifest::CargoToml(it)
+            | ProjectManifest::CargoScript(it) => it,
+        }
+    }
 }
 
 impl fmt::Display for ProjectManifest {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            ProjectManifest::ProjectJson(it) | ProjectManifest::CargoToml(it) => {
-                fmt::Display::fmt(&it, f)
-            }
-        }
+        fmt::Display::fmt(self.manifest_path(), f)
     }
 }
 
diff --git a/crates/project-model/src/manifest_path.rs b/crates/project-model/src/manifest_path.rs
index d86e81e7e1ac..6929a7589543 100644
--- a/crates/project-model/src/manifest_path.rs
+++ b/crates/project-model/src/manifest_path.rs
@@ -1,5 +1,5 @@
 //! See [`ManifestPath`].
-use std::{fmt, ops, path::Path};
+use std::{borrow::Borrow, fmt, ops};
 
 use paths::{AbsPath, AbsPathBuf};
 
@@ -54,8 +54,14 @@ impl ops::Deref for ManifestPath {
     }
 }
 
-impl AsRef<Path> for ManifestPath {
-    fn as_ref(&self) -> &Path {
+impl AsRef<AbsPath> for ManifestPath {
+    fn as_ref(&self) -> &AbsPath {
         self.file.as_ref()
     }
 }
+
+impl Borrow<AbsPath> for ManifestPath {
+    fn borrow(&self) -> &AbsPath {
+        self.file.borrow()
+    }
+}
diff --git a/crates/project-model/src/sysroot.rs b/crates/project-model/src/sysroot.rs
index 1142d6243d29..00dd18b5b11a 100644
--- a/crates/project-model/src/sysroot.rs
+++ b/crates/project-model/src/sysroot.rs
@@ -349,7 +349,7 @@ impl Sysroot {
                     .filter(|&package| RELEVANT_SYSROOT_CRATES.contains(&&*package.name))
                     .map(|package| package.id.clone())
                     .collect();
-                let cargo_workspace = CargoWorkspace::new(res);
+                let cargo_workspace = CargoWorkspace::new(res, sysroot_cargo_toml);
                 Some(Sysroot {
                     root: sysroot_dir.clone(),
                     src_root: Some(Ok(sysroot_src_dir.clone())),
@@ -368,7 +368,7 @@ impl Sysroot {
                 .into_iter()
                 .map(|it| sysroot_src_dir.join(it))
                 .filter_map(|it| ManifestPath::try_from(it).ok())
-                .find(|it| fs::metadata(it).is_ok());
+                .find(|it| fs::metadata(it.as_ref()).is_ok());
 
             if let Some(root) = root {
                 stitched.crates.alloc(SysrootCrateData {
@@ -468,7 +468,7 @@ fn get_rustc_src(sysroot_path: &AbsPath) -> Option<ManifestPath> {
     let rustc_src = sysroot_path.join("lib/rustlib/rustc-src/rust/compiler/rustc/Cargo.toml");
     let rustc_src = ManifestPath::try_from(rustc_src).ok()?;
     tracing::debug!("checking for rustc source code: {rustc_src}");
-    if fs::metadata(&rustc_src).is_ok() {
+    if fs::metadata(rustc_src.as_ref()).is_ok() {
         Some(rustc_src)
     } else {
         None
diff --git a/crates/project-model/src/tests.rs b/crates/project-model/src/tests.rs
index fd09dff503fa..41351d5dc0fc 100644
--- a/crates/project-model/src/tests.rs
+++ b/crates/project-model/src/tests.rs
@@ -1,6 +1,7 @@
 use std::ops::Deref;
 
 use base_db::{CrateGraph, FileId, ProcMacroPaths};
+use cargo_metadata::Metadata;
 use cfg::{CfgAtom, CfgDiff};
 use expect_test::{expect_file, ExpectFile};
 use paths::{AbsPath, AbsPathBuf, Utf8Path, Utf8PathBuf};
@@ -9,8 +10,8 @@ use serde::de::DeserializeOwned;
 use triomphe::Arc;
 
 use crate::{
-    CargoWorkspace, CfgOverrides, ProjectJson, ProjectJsonData, ProjectWorkspace, Sysroot,
-    WorkspaceBuildScripts,
+    CargoWorkspace, CfgOverrides, ManifestPath, ProjectJson, ProjectJsonData, ProjectWorkspace,
+    Sysroot, WorkspaceBuildScripts,
 };
 
 fn load_cargo(file: &str) -> (CrateGraph, ProcMacroPaths) {
@@ -21,8 +22,10 @@ fn load_cargo_with_overrides(
     file: &str,
     cfg_overrides: CfgOverrides,
 ) -> (CrateGraph, ProcMacroPaths) {
-    let meta = get_test_json_file(file);
-    let cargo_workspace = CargoWorkspace::new(meta);
+    let meta: Metadata = get_test_json_file(file);
+    let manifest_path =
+        ManifestPath::try_from(AbsPathBuf::try_from(meta.workspace_root.clone()).unwrap()).unwrap();
+    let cargo_workspace = CargoWorkspace::new(meta, manifest_path);
     let project_workspace = ProjectWorkspace::Cargo {
         cargo: cargo_workspace,
         build_scripts: WorkspaceBuildScripts::default(),
@@ -41,8 +44,10 @@ fn load_cargo_with_fake_sysroot(
     file_map: &mut FxHashMap<AbsPathBuf, FileId>,
     file: &str,
 ) -> (CrateGraph, ProcMacroPaths) {
-    let meta = get_test_json_file(file);
-    let cargo_workspace = CargoWorkspace::new(meta);
+    let meta: Metadata = get_test_json_file(file);
+    let manifest_path =
+        ManifestPath::try_from(AbsPathBuf::try_from(meta.workspace_root.clone()).unwrap()).unwrap();
+    let cargo_workspace = CargoWorkspace::new(meta, manifest_path);
     let project_workspace = ProjectWorkspace::Cargo {
         cargo: cargo_workspace,
         build_scripts: WorkspaceBuildScripts::default(),
@@ -268,9 +273,10 @@ fn smoke_test_real_sysroot_cargo() {
         return;
     }
     let file_map = &mut FxHashMap::<AbsPathBuf, FileId>::default();
-    let meta = get_test_json_file("hello-world-metadata.json");
-
-    let cargo_workspace = CargoWorkspace::new(meta);
+    let meta: Metadata = get_test_json_file("hello-world-metadata.json");
+    let manifest_path =
+        ManifestPath::try_from(AbsPathBuf::try_from(meta.workspace_root.clone()).unwrap()).unwrap();
+    let cargo_workspace = CargoWorkspace::new(meta, manifest_path);
     let sysroot = Ok(Sysroot::discover(
         AbsPath::assert(Utf8Path::new(env!("CARGO_MANIFEST_DIR"))),
         &Default::default(),
diff --git a/crates/project-model/src/workspace.rs b/crates/project-model/src/workspace.rs
index 98c5a02dcdcd..9f6e75171b67 100644
--- a/crates/project-model/src/workspace.rs
+++ b/crates/project-model/src/workspace.rs
@@ -4,7 +4,7 @@
 
 use std::{collections::VecDeque, fmt, fs, iter, sync};
 
-use anyhow::{format_err, Context};
+use anyhow::Context;
 use base_db::{
     CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency, Env, FileId,
     LangCrateOrigin, ProcMacroPaths, TargetLayoutLoadResult,
@@ -14,7 +14,6 @@ use paths::{AbsPath, AbsPathBuf};
 use rustc_hash::{FxHashMap, FxHashSet};
 use semver::Version;
 use span::Edition;
-use stdx::always;
 use toolchain::Tool;
 use triomphe::Arc;
 
@@ -101,7 +100,7 @@ pub enum ProjectWorkspace {
     /// Backed by basic sysroot crates for basic completion and highlighting.
     DetachedFile {
         /// The file in question.
-        file: AbsPathBuf,
+        file: ManifestPath,
         /// The sysroot loaded for this workspace.
         sysroot: Result<Sysroot, Option<String>>,
         /// Holds cfg flags for the current target. We get those by running
@@ -116,7 +115,7 @@ pub enum ProjectWorkspace {
         /// A set of cfg overrides for the files.
         cfg_overrides: CfgOverrides,
         /// Is this file a cargo script file?
-        cargo_script: Option<CargoWorkspace>,
+        cargo_script: Option<(CargoWorkspace, WorkspaceBuildScripts)>,
     },
 }
 
@@ -230,7 +229,7 @@ impl ProjectWorkspace {
     ) -> anyhow::Result<ProjectWorkspace> {
         let res = match manifest {
             ProjectManifest::ProjectJson(project_json) => {
-                let file = fs::read_to_string(project_json)
+                let file = fs::read_to_string(project_json.as_ref())
                     .with_context(|| format!("Failed to read json file {project_json}"))?;
                 let data = serde_json::from_str(&file)
                     .with_context(|| format!("Failed to deserialize json file {project_json}"))?;
@@ -243,6 +242,9 @@ impl ProjectWorkspace {
                     &config.cfg_overrides,
                 )
             }
+            ProjectManifest::CargoScript(rust_file) => {
+                ProjectWorkspace::load_detached_file(rust_file, config)?
+            }
             ProjectManifest::CargoToml(cargo_toml) => {
                 let sysroot = match (&config.sysroot, &config.sysroot_src) {
                     (Some(RustLibSource::Path(path)), None) => {
@@ -299,7 +301,7 @@ impl ProjectWorkspace {
                         progress,
                     ) {
                         Ok(meta) => {
-                            let workspace = CargoWorkspace::new(meta);
+                            let workspace = CargoWorkspace::new(meta, cargo_toml.clone());
                             let buildscripts = WorkspaceBuildScripts::rustc_crates(
                                 &workspace,
                                 cargo_toml.parent(),
@@ -355,7 +357,7 @@ impl ProjectWorkspace {
                         "Failed to read Cargo metadata from Cargo.toml file {cargo_toml}, {toolchain:?}",
                     )
                 })?;
-                let cargo = CargoWorkspace::new(meta);
+                let cargo = CargoWorkspace::new(meta, cargo_toml.clone());
 
                 let cargo_config_extra_env =
                     cargo_config_env(cargo_toml, &config.extra_env, sysroot_ref);
@@ -433,82 +435,71 @@ impl ProjectWorkspace {
         }
     }
 
-    pub fn load_detached_files(
-        detached_files: Vec<AbsPathBuf>,
+    pub fn load_detached_file(
+        detached_file: &ManifestPath,
         config: &CargoConfig,
-    ) -> Vec<anyhow::Result<ProjectWorkspace>> {
-        detached_files
-            .into_iter()
-            .map(|detached_file| {
-                let dir = detached_file
-                    .parent()
-                    .ok_or_else(|| format_err!("detached file has no parent"))?;
-                let sysroot = match &config.sysroot {
-                    Some(RustLibSource::Path(path)) => {
-                        Sysroot::with_sysroot_dir(path.clone(), config.sysroot_query_metadata)
-                            .map_err(|e| Some(format!("Failed to find sysroot at {path}:{e}")))
-                    }
-                    Some(RustLibSource::Discover) => {
-                        Sysroot::discover(dir, &config.extra_env, config.sysroot_query_metadata)
-                            .map_err(|e| {
-                                Some(format!(
-                                    "Failed to find sysroot for {dir}. Is rust-src installed? {e}"
-                                ))
-                            })
-                    }
-                    None => Err(None),
-                };
+    ) -> anyhow::Result<ProjectWorkspace> {
+        let dir = detached_file.parent();
+        let sysroot = match &config.sysroot {
+            Some(RustLibSource::Path(path)) => {
+                Sysroot::with_sysroot_dir(path.clone(), config.sysroot_query_metadata)
+                    .map_err(|e| Some(format!("Failed to find sysroot at {path}:{e}")))
+            }
+            Some(RustLibSource::Discover) => Sysroot::discover(
+                dir,
+                &config.extra_env,
+                config.sysroot_query_metadata,
+            )
+            .map_err(|e| {
+                Some(format!("Failed to find sysroot for {dir}. Is rust-src installed? {e}"))
+            }),
+            None => Err(None),
+        };
 
-                let sysroot_ref = sysroot.as_ref().ok();
-                let toolchain = match get_toolchain_version(
-                    dir,
-                    sysroot_ref,
-                    Tool::Rustc,
-                    &config.extra_env,
-                    "rustc ",
-                ) {
-                    Ok(it) => it,
-                    Err(e) => {
-                        tracing::error!("{e}");
-                        None
-                    }
-                };
+        let sysroot_ref = sysroot.as_ref().ok();
+        let toolchain =
+            match get_toolchain_version(dir, sysroot_ref, Tool::Rustc, &config.extra_env, "rustc ")
+            {
+                Ok(it) => it,
+                Err(e) => {
+                    tracing::error!("{e}");
+                    None
+                }
+            };
 
-                let rustc_cfg =
-                    rustc_cfg::get(None, &config.extra_env, RustcCfgConfig::Rustc(sysroot_ref));
-                let data_layout = target_data_layout::get(
-                    RustcDataLayoutConfig::Rustc(sysroot_ref),
-                    None,
-                    &config.extra_env,
-                );
+        let rustc_cfg = rustc_cfg::get(None, &config.extra_env, RustcCfgConfig::Rustc(sysroot_ref));
+        let data_layout = target_data_layout::get(
+            RustcDataLayoutConfig::Rustc(sysroot_ref),
+            None,
+            &config.extra_env,
+        );
 
-                let cargo_script = ManifestPath::try_from(detached_file.clone())
-                    .ok()
-                    .and_then(|file| {
-                        CargoWorkspace::fetch_metadata(
-                            &file,
-                            file.parent(),
-                            config,
-                            sysroot_ref,
-                            &|_| (),
-                        )
-                        .ok()
-                    })
-                    .map(CargoWorkspace::new);
+        let cargo_script =
+            CargoWorkspace::fetch_metadata(detached_file, dir, config, sysroot_ref, &|_| ())
+                .ok()
+                .map(|ws| {
+                    (
+                        CargoWorkspace::new(ws, detached_file.clone()),
+                        WorkspaceBuildScripts::default(),
+                    )
+                });
 
-                Ok(ProjectWorkspace::DetachedFile {
-                    file: detached_file,
-                    sysroot,
-                    rustc_cfg,
-                    toolchain,
-                    target_layout: data_layout
-                        .map(Arc::from)
-                        .map_err(|it| Arc::from(it.to_string())),
-                    cfg_overrides: config.cfg_overrides.clone(),
-                    cargo_script,
-                })
-            })
-            .collect()
+        Ok(ProjectWorkspace::DetachedFile {
+            file: detached_file.to_owned(),
+            sysroot,
+            rustc_cfg,
+            toolchain,
+            target_layout: data_layout.map(Arc::from).map_err(|it| Arc::from(it.to_string())),
+            cfg_overrides: config.cfg_overrides.clone(),
+            cargo_script,
+        })
+    }
+
+    pub fn load_detached_files(
+        detached_files: Vec<ManifestPath>,
+        config: &CargoConfig,
+    ) -> Vec<anyhow::Result<ProjectWorkspace>> {
+        detached_files.into_iter().map(|file| Self::load_detached_file(&file, config)).collect()
     }
 
     /// Runs the build scripts for this [`ProjectWorkspace`].
@@ -519,7 +510,7 @@ impl ProjectWorkspace {
     ) -> anyhow::Result<WorkspaceBuildScripts> {
         match self {
             ProjectWorkspace::DetachedFile {
-                cargo_script: Some(cargo),
+                cargo_script: Some((cargo, _)),
                 toolchain,
                 sysroot,
                 ..
@@ -586,10 +577,11 @@ impl ProjectWorkspace {
 
     pub fn set_build_scripts(&mut self, bs: WorkspaceBuildScripts) {
         match self {
-            ProjectWorkspace::Cargo { build_scripts, .. } => *build_scripts = bs,
-            _ => {
-                always!(bs == WorkspaceBuildScripts::default());
+            ProjectWorkspace::Cargo { build_scripts, .. }
+            | ProjectWorkspace::DetachedFile { cargo_script: Some((_, build_scripts)), .. } => {
+                *build_scripts = bs
             }
+            _ => assert_eq!(bs, WorkspaceBuildScripts::default()),
         }
     }
 
@@ -742,15 +734,18 @@ impl ProjectWorkspace {
             ProjectWorkspace::DetachedFile { file, cargo_script, sysroot, .. } => {
                 iter::once(PackageRoot {
                     is_local: true,
-                    include: vec![file.clone()],
+                    include: vec![file.as_ref().to_owned()],
                     exclude: Vec::new(),
                 })
-                .chain(cargo_script.iter().flat_map(|cargo| {
+                .chain(cargo_script.iter().flat_map(|(cargo, build_scripts)| {
                     cargo.packages().map(|pkg| {
                         let is_local = cargo[pkg].is_local;
                         let pkg_root = cargo[pkg].manifest.parent().to_path_buf();
 
                         let mut include = vec![pkg_root.clone()];
+                        let out_dir =
+                            build_scripts.get_output(pkg).and_then(|it| it.out_dir.clone());
+                        include.extend(out_dir);
 
                         // In case target's path is manually set in Cargo.toml to be
                         // outside the package root, add its parent as an extra include.
@@ -801,7 +796,7 @@ impl ProjectWorkspace {
             ProjectWorkspace::DetachedFile { sysroot, cargo_script, .. } => {
                 let sysroot_package_len = sysroot.as_ref().map_or(0, |it| it.num_packages());
                 sysroot_package_len
-                    + cargo_script.as_ref().map_or(1, |cargo| cargo.packages().len())
+                    + cargo_script.as_ref().map_or(1, |(cargo, _)| cargo.packages().len())
             }
         }
     }
@@ -863,7 +858,7 @@ impl ProjectWorkspace {
                 cfg_overrides,
                 cargo_script,
             } => (
-                if let Some(cargo) = cargo_script {
+                if let Some((cargo, build_scripts)) = cargo_script {
                     cargo_to_crate_graph(
                         &mut |path| load(path),
                         None,
@@ -871,7 +866,7 @@ impl ProjectWorkspace {
                         sysroot.as_ref().ok(),
                         rustc_cfg.clone(),
                         cfg_overrides,
-                        &WorkspaceBuildScripts::default(),
+                        build_scripts,
                     )
                 } else {
                     detached_file_to_crate_graph(
@@ -959,7 +954,7 @@ impl ProjectWorkspace {
                     file,
                     sysroot,
                     rustc_cfg,
-                    cargo_script,
+                    cargo_script: Some((cargo_script, _)),
                     toolchain,
                     target_layout,
                     cfg_overrides,
@@ -968,7 +963,7 @@ impl ProjectWorkspace {
                     file: o_file,
                     sysroot: o_sysroot,
                     rustc_cfg: o_rustc_cfg,
-                    cargo_script: o_cargo_script,
+                    cargo_script: Some((o_cargo_script, _)),
                     toolchain: o_toolchain,
                     target_layout: o_target_layout,
                     cfg_overrides: o_cfg_overrides,
@@ -1294,11 +1289,11 @@ fn cargo_to_crate_graph(
 fn detached_file_to_crate_graph(
     rustc_cfg: Vec<CfgFlag>,
     load: FileLoader<'_>,
-    detached_file: &AbsPathBuf,
+    detached_file: &ManifestPath,
     sysroot: Option<&Sysroot>,
     override_cfg: &CfgOverrides,
 ) -> (CrateGraph, ProcMacroPaths) {
-    let _p = tracing::span!(tracing::Level::INFO, "detached_files_to_crate_graph").entered();
+    let _p = tracing::span!(tracing::Level::INFO, "detached_file_to_crate_graph").entered();
     let mut crate_graph = CrateGraph::default();
     let (public_deps, _libproc_macro) = match sysroot {
         Some(sysroot) => sysroot_to_crate_graph(&mut crate_graph, sysroot, rustc_cfg.clone(), load),
diff --git a/crates/rust-analyzer/src/cli/progress_report.rs b/crates/rust-analyzer/src/cli/progress_report.rs
index 6964977840a0..8b143daf2aea 100644
--- a/crates/rust-analyzer/src/cli/progress_report.rs
+++ b/crates/rust-analyzer/src/cli/progress_report.rs
@@ -96,7 +96,7 @@ impl<'a> ProgressReport<'a> {
     }
 
     fn set_value(&mut self, value: f32) {
-        self.curr = f32::max(0.0, f32::min(1.0, value));
+        self.curr = value.clamp(0.0, 1.0);
     }
 
     fn clear(&mut self) {
diff --git a/crates/rust-analyzer/src/cli/rustc_tests.rs b/crates/rust-analyzer/src/cli/rustc_tests.rs
index 2f9394d0ee1b..cd15d86aa6cd 100644
--- a/crates/rust-analyzer/src/cli/rustc_tests.rs
+++ b/crates/rust-analyzer/src/cli/rustc_tests.rs
@@ -10,7 +10,9 @@ use ide::{AnalysisHost, DiagnosticCode, DiagnosticsConfig};
 use itertools::Either;
 use profile::StopWatch;
 use project_model::target_data_layout::RustcDataLayoutConfig;
-use project_model::{target_data_layout, CargoConfig, ProjectWorkspace, RustLibSource, Sysroot};
+use project_model::{
+    target_data_layout, CargoConfig, ManifestPath, ProjectWorkspace, RustLibSource, Sysroot,
+};
 
 use load_cargo::{load_workspace, LoadCargoConfig, ProcMacroServerChoice};
 use rustc_hash::FxHashMap;
@@ -76,7 +78,7 @@ impl Tester {
         );
 
         let workspace = ProjectWorkspace::DetachedFile {
-            file: tmp_file,
+            file: ManifestPath::try_from(tmp_file).unwrap(),
             sysroot,
             rustc_cfg: vec![],
             toolchain: None,
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index e956791d9df7..5842c1d2ecfb 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -356,7 +356,8 @@ config_data! {
         /// of projects.
         ///
         /// Elements must be paths pointing to `Cargo.toml`,
-        /// `rust-project.json`, or JSON objects in `rust-project.json` format.
+        /// `rust-project.json`, `.rs` files (which will be treated as standalone files) or JSON
+        /// objects in `rust-project.json` format.
         linkedProjects: Vec<ManifestOrProjectJson> = vec![],
 
         /// Number of syntax trees rust-analyzer keeps in memory. Defaults to 128.
@@ -1301,12 +1302,9 @@ impl Config {
                     self.files_excludeDirs().iter().map(|p| self.root_path.join(p)).collect();
                 self.discovered_projects
                     .iter()
-                    .filter(
-                        |(ProjectManifest::ProjectJson(path)
-                         | ProjectManifest::CargoToml(path))| {
-                            !exclude_dirs.iter().any(|p| path.starts_with(p))
-                        },
-                    )
+                    .filter(|project| {
+                        !exclude_dirs.iter().any(|p| project.manifest_path().starts_with(p))
+                    })
                     .cloned()
                     .map(LinkedProject::from)
                     .collect()
diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
index e9bca19af646..eaf3f511c488 100644
--- a/crates/rust-analyzer/src/global_state.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -18,7 +18,9 @@ use parking_lot::{
     RwLockWriteGuard,
 };
 use proc_macro_api::ProcMacroServer;
-use project_model::{CargoWorkspace, ProjectWorkspace, Target, WorkspaceBuildScripts};
+use project_model::{
+    CargoWorkspace, ManifestPath, ProjectWorkspace, Target, WorkspaceBuildScripts,
+};
 use rustc_hash::{FxHashMap, FxHashSet};
 use triomphe::Arc;
 use vfs::{AnchoredPathBuf, ChangedFile, Vfs};
@@ -125,7 +127,7 @@ pub(crate) struct GlobalState {
     /// to invalidate any salsa caches.
     pub(crate) workspaces: Arc<Vec<ProjectWorkspace>>,
     pub(crate) crate_graph_file_dependencies: FxHashSet<vfs::VfsPath>,
-    pub(crate) detached_files: FxHashSet<vfs::AbsPathBuf>,
+    pub(crate) detached_files: FxHashSet<ManifestPath>,
 
     // op queues
     pub(crate) fetch_workspaces_queue:
diff --git a/crates/rust-analyzer/src/handlers/request.rs b/crates/rust-analyzer/src/handlers/request.rs
index cf97d7d9d234..39cdef08f84b 100644
--- a/crates/rust-analyzer/src/handlers/request.rs
+++ b/crates/rust-analyzer/src/handlers/request.rs
@@ -1759,11 +1759,12 @@ pub(crate) fn handle_open_docs(
     let position = from_proto::file_position(&snap, params)?;
 
     let ws_and_sysroot = snap.workspaces.iter().find_map(|ws| match ws {
-        ProjectWorkspace::Cargo { cargo, sysroot, .. } => Some((cargo, sysroot.as_ref().ok())),
-        ProjectWorkspace::Json { .. } => None,
-        ProjectWorkspace::DetachedFile { cargo_script, sysroot, .. } => {
-            cargo_script.as_ref().zip(Some(sysroot.as_ref().ok()))
+        ProjectWorkspace::Cargo { cargo, sysroot, .. }
+        | ProjectWorkspace::DetachedFile { cargo_script: Some((cargo, _)), sysroot, .. } => {
+            Some((cargo, sysroot.as_ref().ok()))
         }
+        ProjectWorkspace::Json { .. } => None,
+        ProjectWorkspace::DetachedFile { .. } => None,
     });
 
     let (cargo, sysroot) = match ws_and_sysroot {
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
index 5d8a66cabc7d..4cc174731c90 100644
--- a/crates/rust-analyzer/src/reload.rs
+++ b/crates/rust-analyzer/src/reload.rs
@@ -25,7 +25,7 @@ use ide_db::{
 use itertools::Itertools;
 use load_cargo::{load_proc_macro, ProjectFolders};
 use proc_macro_api::ProcMacroServer;
-use project_model::{ProjectWorkspace, WorkspaceBuildScripts};
+use project_model::{ManifestPath, ProjectWorkspace, WorkspaceBuildScripts};
 use stdx::{format_to, thread::ThreadIntent};
 use triomphe::Arc;
 use vfs::{AbsPath, AbsPathBuf, ChangeKind};
@@ -204,7 +204,14 @@ impl GlobalState {
 
         self.task_pool.handle.spawn_with_sender(ThreadIntent::Worker, {
             let linked_projects = self.config.linked_or_discovered_projects();
-            let detached_files = self.config.detached_files().to_vec();
+            let detached_files: Vec<_> = self
+                .config
+                .detached_files()
+                .iter()
+                .cloned()
+                .map(ManifestPath::try_from)
+                .filter_map(Result::ok)
+                .collect();
             let cargo_config = self.config.cargo();
 
             move |sender| {
diff --git a/crates/rust-analyzer/tests/crate_graph.rs b/crates/rust-analyzer/tests/crate_graph.rs
index cf38032b9418..e833ea5e111c 100644
--- a/crates/rust-analyzer/tests/crate_graph.rs
+++ b/crates/rust-analyzer/tests/crate_graph.rs
@@ -1,14 +1,18 @@
 use std::path::PathBuf;
 
-use project_model::{CargoWorkspace, ProjectWorkspace, Sysroot, WorkspaceBuildScripts};
+use project_model::{
+    CargoWorkspace, ManifestPath, Metadata, ProjectWorkspace, Sysroot, WorkspaceBuildScripts,
+};
 use rust_analyzer::ws_to_crate_graph;
 use rustc_hash::FxHashMap;
 use serde::de::DeserializeOwned;
 use vfs::{AbsPathBuf, FileId};
 
 fn load_cargo_with_fake_sysroot(file: &str) -> ProjectWorkspace {
-    let meta = get_test_json_file(file);
-    let cargo_workspace = CargoWorkspace::new(meta);
+    let meta: Metadata = get_test_json_file(file);
+    let manifest_path =
+        ManifestPath::try_from(AbsPathBuf::try_from(meta.workspace_root.clone()).unwrap()).unwrap();
+    let cargo_workspace = CargoWorkspace::new(meta, manifest_path);
     ProjectWorkspace::Cargo {
         cargo: cargo_workspace,
         build_scripts: WorkspaceBuildScripts::default(),
diff --git a/crates/rust-analyzer/tests/slow-tests/main.rs b/crates/rust-analyzer/tests/slow-tests/main.rs
index b87f02947bf3..2ca86bc50a32 100644
--- a/crates/rust-analyzer/tests/slow-tests/main.rs
+++ b/crates/rust-analyzer/tests/slow-tests/main.rs
@@ -150,6 +150,7 @@ use dependency2::Spam;
     )
     .with_config(serde_json::json!({
         "cargo": { "sysroot": null },
+        "detachedFiles": ["/src/lib.rs"],
     }))
     .server()
     .wait_until_workspace_is_loaded();
diff --git a/crates/rust-analyzer/tests/slow-tests/support.rs b/crates/rust-analyzer/tests/slow-tests/support.rs
index f04962a7a276..cf27cc7eeff6 100644
--- a/crates/rust-analyzer/tests/slow-tests/support.rs
+++ b/crates/rust-analyzer/tests/slow-tests/support.rs
@@ -185,11 +185,7 @@ impl Project<'_> {
             roots,
             None,
         );
-        // TODO: don't hardcode src/lib.rs as detached file
-        let mut c = self.config;
-        let p = tmp_dir_path.join("src/lib.rs").to_string();
-        c["detachedFiles"] = serde_json::json!([p]);
-        config.update(c).expect("invalid config");
+        config.update(self.config).expect("invalid config");
         config.rediscover_workspaces();
 
         Server::new(tmp_dir.keep(), config)
diff --git a/docs/user/generated_config.adoc b/docs/user/generated_config.adoc
index a03ab0031d19..6e4820c5deaa 100644
--- a/docs/user/generated_config.adoc
+++ b/docs/user/generated_config.adoc
@@ -778,7 +778,8 @@ Disable project auto-discovery in favor of explicitly specified set
 of projects.
 
 Elements must be paths pointing to `Cargo.toml`,
-`rust-project.json`, or JSON objects in `rust-project.json` format.
+`rust-project.json`, `.rs` files (which will be treated as standalone files) or JSON
+objects in `rust-project.json` format.
 --
 [[rust-analyzer.lru.capacity]]rust-analyzer.lru.capacity (default: `null`)::
 +
diff --git a/editors/code/package.json b/editors/code/package.json
index 389e1b8742cc..352eb2422934 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -1495,7 +1495,7 @@
                     "type": "boolean"
                 },
                 "rust-analyzer.linkedProjects": {
-                    "markdownDescription": "Disable project auto-discovery in favor of explicitly specified set\nof projects.\n\nElements must be paths pointing to `Cargo.toml`,\n`rust-project.json`, or JSON objects in `rust-project.json` format.",
+                    "markdownDescription": "Disable project auto-discovery in favor of explicitly specified set\nof projects.\n\nElements must be paths pointing to `Cargo.toml`,\n`rust-project.json`, `.rs` files (which will be treated as standalone files) or JSON\nobjects in `rust-project.json` format.",
                     "default": [],
                     "type": "array",
                     "items": {