Move FeatureFlags

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

@@ -6,7 +6,7 @@ use std::path::Path;
 use anyhow::Result;
 use crossbeam_channel::{unbounded, Receiver};
 use ra_db::{CrateGraph, FileId, SourceRootId};
-use ra_ide::{AnalysisChange, AnalysisHost, FeatureFlags};
+use ra_ide::{AnalysisChange, AnalysisHost};
 use ra_project_model::{get_rustc_cfg_options, PackageRoot, ProjectWorkspace};
 use ra_vfs::{RootEntry, Vfs, VfsChange, VfsTask, Watch};
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -82,7 +82,7 @@ pub(crate) fn load(
     receiver: Receiver<VfsTask>,
 ) -> AnalysisHost {
     let lru_cap = std::env::var("RA_LRU_CAP").ok().and_then(|it| it.parse::<usize>().ok());
-    let mut host = AnalysisHost::new(lru_cap, FeatureFlags::default());
+    let mut host = AnalysisHost::new(lru_cap);
     let mut analysis_change = AnalysisChange::new();
     analysis_change.set_crate_graph(crate_graph);
 

crates/rust-analyzer/src/feature_flags.rs

@@ -0,0 +1,77 @@
+//! See docs for `FeatureFlags`.
+
+use rustc_hash::FxHashMap;
+
+// FIXME: looks like a much better design is to pass options to each call,
+// rather than to have a global ambient feature flags -- that way, the clients
+// can issue two successive calls with different options.
+
+/// Feature flags hold fine-grained toggles for all *user-visible* features of
+/// rust-analyzer.
+///
+/// The exists such that users are able to disable any annoying feature (and,
+/// with many users and many features,  some features are bound to be annoying
+/// for some users)
+///
+/// Note that we purposefully use run-time checked strings, and not something
+/// checked at compile time, to keep things simple and flexible.
+///
+/// Also note that, at the moment, `FeatureFlags` also store features for
+/// `rust-analyzer`. This should be benign layering violation.
+#[derive(Debug)]
+pub struct FeatureFlags {
+    flags: FxHashMap<String, bool>,
+}
+
+impl FeatureFlags {
+    fn new(flags: &[(&str, bool)]) -> FeatureFlags {
+        let flags = flags
+            .iter()
+            .map(|&(name, value)| {
+                check_flag_name(name);
+                (name.to_string(), value)
+            })
+            .collect();
+        FeatureFlags { flags }
+    }
+
+    pub fn set(&mut self, flag: &str, value: bool) -> Result<(), ()> {
+        match self.flags.get_mut(flag) {
+            None => Err(()),
+            Some(slot) => {
+                *slot = value;
+                Ok(())
+            }
+        }
+    }
+
+    pub fn get(&self, flag: &str) -> bool {
+        match self.flags.get(flag) {
+            None => panic!("unknown flag: {:?}", flag),
+            Some(value) => *value,
+        }
+    }
+}
+
+impl Default for FeatureFlags {
+    fn default() -> FeatureFlags {
+        FeatureFlags::new(&[
+            ("lsp.diagnostics", true),
+            ("completion.insertion.add-call-parenthesis", true),
+            ("completion.insertion.add-argument-snippets", true),
+            ("completion.enable-postfix", true),
+            ("call-info.full", true),
+            ("notifications.workspace-loaded", true),
+            ("notifications.cargo-toml-not-found", true),
+        ])
+    }
+}
+
+fn check_flag_name(flag: &str) {
+    for c in flag.bytes() {
+        match c {
+            b'a'..=b'z' | b'-' | b'.' => (),
+            _ => panic!("flag name does not match conventions: {:?}", flag),
+        }
+    }
+}

crates/rust-analyzer/src/lib.rs

@@ -37,6 +37,7 @@ mod config;
 mod world;
 mod diagnostics;
 mod semantic_tokens;
+mod feature_flags;
 
 use serde::de::DeserializeOwned;
 

crates/rust-analyzer/src/main_loop.rs

@@ -18,7 +18,7 @@ use crossbeam_channel::{select, unbounded, RecvError, Sender};
 use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
 use lsp_types::{ClientCapabilities, NumberOrString};
 use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckTask};
-use ra_ide::{Canceled, FeatureFlags, FileId, LibraryData, SourceRootId};
+use ra_ide::{Canceled, FileId, LibraryData, SourceRootId};
 use ra_prof::profile;
 use ra_vfs::{VfsFile, VfsTask, Watch};
 use relative_path::RelativePathBuf;
@@ -28,6 +28,7 @@ use threadpool::ThreadPool;
 
 use crate::{
     diagnostics::DiagnosticTask,
+    feature_flags::FeatureFlags,
     main_loop::{
         pending_requests::{PendingRequest, PendingRequests},
         subscriptions::Subscriptions,
@@ -423,7 +424,7 @@ fn loop_turn(
     {
         loop_state.workspace_loaded = true;
         let n_packages: usize = world_state.workspaces.iter().map(|it| it.n_packages()).sum();
-        if world_state.feature_flags().get("notifications.workspace-loaded") {
+        if world_state.feature_flags.get("notifications.workspace-loaded") {
             let msg = format!("workspace loaded, {} rust packages", n_packages);
             show_message(req::MessageType::Info, msg, &connection.sender);
         }
@@ -839,7 +840,7 @@ fn update_file_notifications_on_threadpool(
     subscriptions: Vec<FileId>,
 ) {
     log::trace!("updating notifications for {:?}", subscriptions);
-    let publish_diagnostics = world.feature_flags().get("lsp.diagnostics");
+    let publish_diagnostics = world.feature_flags.get("lsp.diagnostics");
     pool.execute(move || {
         for file_id in subscriptions {
             if publish_diagnostics {

crates/rust-analyzer/src/main_loop/handlers.rs

@@ -425,12 +425,10 @@ pub fn handle_completion(
     }
 
     let options = CompletionOptions {
-        enable_postfix_completions: world.feature_flags().get("completion.enable-postfix"),
-        add_call_parenthesis: world
-            .feature_flags()
-            .get("completion.insertion.add-call-parenthesis"),
+        enable_postfix_completions: world.feature_flags.get("completion.enable-postfix"),
+        add_call_parenthesis: world.feature_flags.get("completion.insertion.add-call-parenthesis"),
         add_call_argument_snippets: world
-            .feature_flags()
+            .feature_flags
             .get("completion.insertion.add-argument-snippets"),
     };
 
@@ -471,7 +469,7 @@ pub fn handle_signature_help(
     let _p = profile("handle_signature_help");
     let position = params.try_conv_with(&world)?;
     if let Some(call_info) = world.analysis().call_info(position)? {
-        let concise = !world.analysis().feature_flags().get("call-info.full");
+        let concise = !world.feature_flags.get("call-info.full");
         let mut active_parameter = call_info.active_parameter.map(|it| it as i64);
         if concise && call_info.signature.has_self_param {
             active_parameter = active_parameter.map(|it| it.saturating_sub(1));

crates/rust-analyzer/src/world.rs

@@ -13,8 +13,7 @@ use lsp_types::Url;
 use parking_lot::RwLock;
 use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckWatcher};
 use ra_ide::{
-    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FeatureFlags, FileId, LibraryData,
-    SourceRootId,
+    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, LibraryData, SourceRootId,
 };
 use ra_project_model::{get_rustc_cfg_options, ProjectWorkspace};
 use ra_vfs::{LineEndings, RootEntry, Vfs, VfsChange, VfsFile, VfsRoot, VfsTask, Watch};
@@ -22,6 +21,7 @@ use relative_path::RelativePathBuf;
 
 use crate::{
     diagnostics::{CheckFixes, DiagnosticCollection},
+    feature_flags::FeatureFlags,
     main_loop::pending_requests::{CompletedRequest, LatestRequests},
     vfs_glob::{Glob, RustPackageFilterBuilder},
     LspError, Result,
@@ -45,6 +45,7 @@ pub struct Options {
 #[derive(Debug)]
 pub struct WorldState {
     pub options: Options,
+    pub feature_flags: Arc<FeatureFlags>,
     //FIXME: this belongs to `LoopState` rather than to `WorldState`
     pub roots_to_scan: usize,
     pub roots: Vec<PathBuf>,
@@ -60,6 +61,7 @@ pub struct WorldState {
 /// An immutable snapshot of the world's state at a point in time.
 pub struct WorldSnapshot {
     pub options: Options,
+    pub feature_flags: Arc<FeatureFlags>,
     pub workspaces: Arc<Vec<ProjectWorkspace>>,
     pub analysis: Analysis,
     pub latest_requests: Arc<RwLock<LatestRequests>>,
@@ -146,10 +148,11 @@ impl WorldState {
                 CheckWatcher::dummy()
             });
 
-        let mut analysis_host = AnalysisHost::new(lru_capacity, feature_flags);
+        let mut analysis_host = AnalysisHost::new(lru_capacity);
         analysis_host.apply_change(change);
         WorldState {
             options,
+            feature_flags: Arc::new(feature_flags),
             roots_to_scan,
             roots: folder_roots,
             workspaces: Arc::new(workspaces),
@@ -216,6 +219,7 @@ impl WorldState {
     pub fn snapshot(&self) -> WorldSnapshot {
         WorldSnapshot {
             options: self.options.clone(),
+            feature_flags: Arc::clone(&self.feature_flags),
             workspaces: Arc::clone(&self.workspaces),
             analysis: self.analysis_host.analysis(),
             vfs: Arc::clone(&self.vfs),
@@ -235,10 +239,6 @@ impl WorldState {
     pub fn complete_request(&mut self, request: CompletedRequest) {
         self.latest_requests.write().record(request)
     }
-
-    pub fn feature_flags(&self) -> &FeatureFlags {
-        self.analysis_host.feature_flags()
-    }
 }
 
 impl WorldSnapshot {
@@ -306,8 +306,4 @@ impl WorldSnapshot {
         let path = self.vfs.read().file2path(VfsFile(file_id.0));
         self.workspaces.iter().find_map(|ws| ws.workspace_root_for(&path))
     }
-
-    pub fn feature_flags(&self) -> &FeatureFlags {
-        self.analysis.feature_flags()
-    }
 }