feat: TOML based config for rust-analyzer

crates/ide/src/lib.rs

@@ -273,10 +273,17 @@ impl Analysis {
         self.with_db(|db| status::status(db, file_id))
     }
 
-    pub fn source_root(&self, file_id: FileId) -> Cancellable<SourceRootId> {
+    pub fn source_root_id(&self, file_id: FileId) -> Cancellable<SourceRootId> {
         self.with_db(|db| db.file_source_root(file_id))
     }
 
+    pub fn is_local_source_root(&self, source_root_id: SourceRootId) -> Cancellable<bool> {
+        self.with_db(|db| {
+            let sr = db.source_root(source_root_id);
+            !sr.is_library
+        })
+    }
+
     pub fn parallel_prime_caches<F>(&self, num_worker_threads: u8, cb: F) -> Cancellable<()>
     where
         F: Fn(ParallelPrimeCachesProgress) + Sync + std::panic::UnwindSafe,

crates/load-cargo/src/lib.rs

@@ -272,25 +272,24 @@ impl SourceRootConfig {
     /// If a `SourceRoot` doesn't have a parent and is local then it is not contained in this mapping but it can be asserted that it is a root `SourceRoot`.
     pub fn source_root_parent_map(&self) -> FxHashMap<SourceRootId, SourceRootId> {
         let roots = self.fsc.roots();
-        let mut map = FxHashMap::<SourceRootId, SourceRootId>::default();
+        let mut i = 0;
         roots
             .iter()
             .enumerate()
             .filter(|(_, (_, id))| self.local_filesets.contains(id))
             .filter_map(|(idx, (root, root_id))| {
                 // We are interested in parents if they are also local source roots.
                 // So instead of a non-local parent we may take a local ancestor as a parent to a node.
-                roots.iter().take(idx).find_map(|(root2, root2_id)| {
+                roots[..idx].iter().find_map(|(root2, root2_id)| {
+                    i += 1;
                     if self.local_filesets.contains(root2_id) && root.starts_with(root2) {
                         return Some((root_id, root2_id));
                     }
                     None
                 })
             })
-            .for_each(|(child, parent)| {
-                map.insert(SourceRootId(*child as u32), SourceRootId(*parent as u32));
-            });
-        map
+            .map(|(&child, &parent)| (SourceRootId(child as u32), SourceRootId(parent as u32)))
+            .collect()
     }
 }
 

crates/paths/src/lib.rs

@@ -135,6 +135,24 @@ impl AbsPathBuf {
     pub fn pop(&mut self) -> bool {
         self.0.pop()
     }
+
+    /// Equivalent of [`PathBuf::push`] for `AbsPathBuf`.
+    ///
+    /// Extends `self` with `path`.
+    ///
+    /// If `path` is absolute, it replaces the current path.
+    ///
+    /// On Windows:
+    ///
+    /// * if `path` has a root but no prefix (e.g., `\windows`), it
+    ///   replaces everything except for the prefix (if any) of `self`.
+    /// * if `path` has a prefix but no root, it replaces `self`.
+    /// * if `self` has a verbatim prefix (e.g. `\\?\C:\windows`)
+    ///   and `path` is not empty, the new path is normalized: all references
+    ///   to `.` and `..` are removed.
+    pub fn push<P: AsRef<Utf8Path>>(&mut self, suffix: P) {
+        self.0.push(suffix)
+    }
 }
 
 impl fmt::Display for AbsPathBuf {

crates/rust-analyzer/Cargo.toml

@@ -22,6 +22,7 @@ path = "src/bin/main.rs"
 [dependencies]
 anyhow.workspace = true
 crossbeam-channel = "0.5.5"
+dirs = "5.0.1"
 dissimilar.workspace = true
 itertools.workspace = true
 scip = "0.3.3"

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

@@ -15,7 +15,11 @@ use std::{env, fs, path::PathBuf, process::ExitCode, sync::Arc};
 
 use anyhow::Context;
 use lsp_server::Connection;
-use rust_analyzer::{cli::flags, config::Config, from_json};
+use rust_analyzer::{
+    cli::flags,
+    config::{Config, ConfigChange, ConfigErrors},
+    from_json,
+};
 use semver::Version;
 use tracing_subscriber::fmt::writer::BoxMakeWriter;
 use vfs::AbsPathBuf;
@@ -220,16 +224,22 @@ fn run_server() -> anyhow::Result<()> {
         .filter(|workspaces| !workspaces.is_empty())
         .unwrap_or_else(|| vec![root_path.clone()]);
     let mut config =
-        Config::new(root_path, capabilities, workspace_roots, visual_studio_code_version);
+        Config::new(root_path, capabilities, workspace_roots, visual_studio_code_version, None);
     if let Some(json) = initialization_options {
-        if let Err(e) = config.update(json) {
+        let mut change = ConfigChange::default();
+        change.change_client_config(json);
+
+        let error_sink: ConfigErrors;
+        (config, error_sink, _) = config.apply_change(change);
+
+        if !error_sink.is_empty() {
             use lsp_types::{
                 notification::{Notification, ShowMessage},
                 MessageType, ShowMessageParams,
             };
             let not = lsp_server::Notification::new(
                 ShowMessage::METHOD.to_owned(),
-                ShowMessageParams { typ: MessageType::WARNING, message: e.to_string() },
+                ShowMessageParams { typ: MessageType::WARNING, message: error_sink.to_string() },
             );
             connection.sender.send(lsp_server::Message::Notification(not)).unwrap();
         }

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

@@ -10,9 +10,11 @@ use ide_db::LineIndexDatabase;
 use load_cargo::{load_workspace_at, LoadCargoConfig, ProcMacroServerChoice};
 use rustc_hash::{FxHashMap, FxHashSet};
 use scip::types as scip_types;
+use tracing::error;
 
 use crate::{
     cli::flags,
+    config::ConfigChange,
     line_index::{LineEndings, LineIndex, PositionEncoding},
 };
 
@@ -35,12 +37,20 @@ impl flags::Scip {
             lsp_types::ClientCapabilities::default(),
             vec![],
             None,
+            None,
         );
 
         if let Some(p) = self.config_path {
             let mut file = std::io::BufReader::new(std::fs::File::open(p)?);
             let json = serde_json::from_reader(&mut file)?;
-            config.update(json)?;
+            let mut change = ConfigChange::default();
+            change.change_client_config(json);
+
+            let error_sink;
+            (config, error_sink, _) = config.apply_change(change);
+
+            // FIXME @alibektas : What happens to errors without logging?
+            error!(?error_sink, "Config Error(s)");
         }
         let cargo_config = config.cargo();
         let (db, vfs, _) = load_workspace_at(