fix: run flycheck without rev_deps when target is specified

crates/rust-analyzer/src/flycheck.rs

@@ -34,6 +34,14 @@ pub(crate) struct CargoOptions {
     pub(crate) target_dir: Option<Utf8PathBuf>,
 }
 
+#[derive(Clone)]
+pub(crate) enum Target {
+    Bin(String),
+    Example(String),
+    Benchmark(String),
+    Test(String),
+}
+
 impl CargoOptions {
     pub(crate) fn apply_on_command(&self, cmd: &mut Command) {
         for target in &self.target_triples {
@@ -119,13 +127,13 @@ impl FlycheckHandle {
 
     /// Schedule a re-start of the cargo check worker to do a workspace wide check.
     pub(crate) fn restart_workspace(&self, saved_file: Option<AbsPathBuf>) {
-        self.sender.send(StateChange::Restart { package: None, saved_file }).unwrap();
+        self.sender.send(StateChange::Restart { package: None, saved_file, target: None }).unwrap();
     }
 
     /// Schedule a re-start of the cargo check worker to do a package wide check.
-    pub(crate) fn restart_for_package(&self, package: String) {
+    pub(crate) fn restart_for_package(&self, package: String, target: Option<Target>) {
         self.sender
-            .send(StateChange::Restart { package: Some(package), saved_file: None })
+            .send(StateChange::Restart { package: Some(package), saved_file: None, target })
             .unwrap();
     }
 
@@ -183,7 +191,7 @@ pub(crate) enum Progress {
 }
 
 enum StateChange {
-    Restart { package: Option<String>, saved_file: Option<AbsPathBuf> },
+    Restart { package: Option<String>, saved_file: Option<AbsPathBuf>, target: Option<Target> },
     Cancel,
 }
 
@@ -271,7 +279,7 @@ impl FlycheckActor {
                     tracing::debug!(flycheck_id = self.id, "flycheck cancelled");
                     self.cancel_check_process();
                 }
-                Event::RequestStateChange(StateChange::Restart { package, saved_file }) => {
+                Event::RequestStateChange(StateChange::Restart { package, saved_file, target }) => {
                     // Cancel the previously spawned process
                     self.cancel_check_process();
                     while let Ok(restart) = inbox.recv_timeout(Duration::from_millis(50)) {
@@ -281,11 +289,12 @@ impl FlycheckActor {
                         }
                     }
 
-                    let command =
-                        match self.check_command(package.as_deref(), saved_file.as_deref()) {
-                            Some(c) => c,
-                            None => continue,
-                        };
+                    let Some(command) =
+                        self.check_command(package.as_deref(), saved_file.as_deref(), target)
+                    else {
+                        continue;
+                    };
+
                     let formatted_command = format!("{command:?}");
 
                     tracing::debug!(?command, "will restart flycheck");
@@ -381,6 +390,7 @@ impl FlycheckActor {
         &self,
         package: Option<&str>,
         saved_file: Option<&AbsPath>,
+        target: Option<Target>,
     ) -> Option<Command> {
         match &self.config {
             FlycheckConfig::CargoCommand { command, options, ansi_color_output } => {
@@ -396,6 +406,15 @@ impl FlycheckActor {
                     None => cmd.arg("--workspace"),
                 };
 
+                if let Some(tgt) = target {
+                    match tgt {
+                        Target::Bin(tgt) => cmd.arg("--bin").arg(tgt),
+                        Target::Example(tgt) => cmd.arg("--example").arg(tgt),
+                        Target::Test(tgt) => cmd.arg("--test").arg(tgt),
+                        Target::Benchmark(tgt) => cmd.arg("--bench").arg(tgt),
+                    };
+                }
+
                 cmd.arg(if *ansi_color_output {
                     "--message-format=json-diagnostic-rendered-ansi"
                 } else {

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

@@ -15,11 +15,13 @@ use vfs::{AbsPathBuf, ChangeKind, VfsPath};
 
 use crate::{
     config::{Config, ConfigChange},
+    flycheck::Target,
     global_state::{FetchWorkspaceRequest, GlobalState},
     lsp::{from_proto, utils::apply_document_changes},
     lsp_ext::{self, RunFlycheckParams},
     mem_docs::DocumentData,
     reload,
+    target_spec::TargetSpec,
 };
 
 pub(crate) fn handle_cancel(state: &mut GlobalState, params: CancelParams) -> anyhow::Result<()> {
@@ -287,16 +289,40 @@ fn run_flycheck(state: &mut GlobalState, vfs_path: VfsPath) -> bool {
         let world = state.snapshot();
         let mut updated = false;
         let task = move || -> std::result::Result<(), ide::Cancelled> {
-            // Trigger flychecks for all workspaces that depend on the saved file
-            // Crates containing or depending on the saved file
-            let crate_ids: Vec<_> = world
-                .analysis
-                .crates_for(file_id)?
-                .into_iter()
-                .flat_map(|id| world.analysis.transitive_rev_deps(id))
-                .flatten()
-                .unique()
-                .collect();
+            // Is the target binary? If so we let flycheck run only for the workspace that contains the crate.
+            let target = TargetSpec::for_file(&world, file_id)?.and_then(|x| {
+                let tgt_kind = x.target_kind();
+                let tgt_name = match x {
+                    TargetSpec::Cargo(c) => c.target,
+                    TargetSpec::ProjectJson(p) => p.label,
+                };
+
+                let tgt = match tgt_kind {
+                    project_model::TargetKind::Bin => Target::Bin(tgt_name),
+                    project_model::TargetKind::Example => Target::Example(tgt_name),
+                    project_model::TargetKind::Test => Target::Test(tgt_name),
+                    project_model::TargetKind::Bench => Target::Benchmark(tgt_name),
+                    _ => return None,
+                };
+
+                Some(tgt)
+            });
+
+            let crate_ids = if target.is_some() {
+                // Trigger flychecks for the only workspace which the binary crate belongs to
+                world.analysis.crates_for(file_id)?.into_iter().unique().collect::<Vec<_>>()
+            } else {
+                // Trigger flychecks for all workspaces that depend on the saved file
+                // Crates containing or depending on the saved file
+                world
+                    .analysis
+                    .crates_for(file_id)?
+                    .into_iter()
+                    .flat_map(|id| world.analysis.transitive_rev_deps(id))
+                    .flatten()
+                    .unique()
+                    .collect::<Vec<_>>()
+            };
 
             let crate_root_paths: Vec<_> = crate_ids
                 .iter()
@@ -346,8 +372,10 @@ fn run_flycheck(state: &mut GlobalState, vfs_path: VfsPath) -> bool {
                 for (id, package) in workspace_ids.clone() {
                     if id == flycheck.id() {
                         updated = true;
-                        match package.filter(|_| !world.config.flycheck_workspace()) {
-                            Some(package) => flycheck.restart_for_package(package),
+                        match package
+                            .filter(|_| !world.config.flycheck_workspace() || target.is_some())
+                        {
+                            Some(package) => flycheck.restart_for_package(package, target.clone()),
                             None => flycheck.restart_workspace(saved_file.clone()),
                         }
                         continue;