Show settings path in --show-settings output

crates/ruff/src/resolver.rs

@@ -166,7 +166,11 @@ pub fn resolve_scoped_settings(
 ) -> Result<(PathBuf, AllSettings)> {
     let configuration = resolve_configuration(pyproject, relativity, processor)?;
     let project_root = relativity.resolve(pyproject);
-    let settings = AllSettings::from_configuration(configuration, &project_root)?;
+    let settings = AllSettings::from_configuration(
+        configuration,
+        &project_root,
+        Some(pyproject.to_path_buf()),
+    )?;
     Ok((project_root, settings))
 }
 

crates/ruff/src/settings/mod.rs

@@ -13,6 +13,7 @@ use strum::IntoEnumIterator;
 use ruff_cache::cache_dir;
 use ruff_macros::CacheKey;
 
+use crate::fs;
 use crate::registry::{Rule, RuleNamespace, RuleSet, INCOMPATIBLE_CODES};
 use crate::rule_selector::{RuleSelector, Specificity};
 use crate::rules::{
@@ -43,10 +44,15 @@ const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
 pub struct AllSettings {
     pub cli: CliSettings,
     pub lib: Settings,
+    settings_path: Option<PathBuf>,
 }
 
 impl AllSettings {
-    pub fn from_configuration(config: Configuration, project_root: &Path) -> Result<Self> {
+    pub fn from_configuration(
+        config: Configuration,
+        project_root: &Path,
+        settings_path: Option<PathBuf>,
+    ) -> Result<Self> {
         Ok(Self {
             cli: CliSettings {
                 cache_dir: config
@@ -60,8 +66,13 @@ impl AllSettings {
                 update_check: config.update_check.unwrap_or_default(),
             },
             lib: Settings::from_configuration(config, project_root)?,
+            settings_path: settings_path.map(fs::normalize_path),
         })
     }
+
+    pub fn settings_path(&self) -> Option<&Path> {
+        self.settings_path.as_deref()
+    }
 }
 
 #[derive(Debug, Default, Clone)]

crates/ruff_cli/src/commands/run.rs

@@ -238,7 +238,11 @@ mod test {
 
         let diagnostics = run(
             &[root_path.join("valid.ipynb")],
-            &PyprojectDiscovery::Fixed(AllSettings::from_configuration(configuration, &root_path)?),
+            &PyprojectDiscovery::Fixed(AllSettings::from_configuration(
+                configuration,
+                &root_path,
+                None,
+            )?),
             &overrides,
             Cache::Disabled,
             Noqa::Enabled,

crates/ruff_cli/src/commands/show_settings.rs

@@ -30,6 +30,9 @@ pub fn show_settings(
 
     let mut stdout = BufWriter::new(io::stdout().lock());
     writeln!(stdout, "Resolved settings for: {path:?}")?;
+    if let Some(settings_path) = pyproject_strategy.top_level_settings().settings_path() {
+        writeln!(stdout, "Settings path: {settings_path:?}")?;
+    }
     writeln!(stdout, "{settings:#?}")?;
 
     Ok(())

crates/ruff_cli/src/resolve.rs

@@ -23,7 +23,7 @@ pub fn resolve(
     if isolated {
         let mut config = Configuration::default();
         overrides.process_config(&mut config);
-        let settings = AllSettings::from_configuration(config, &path_dedot::CWD)?;
+        let settings = AllSettings::from_configuration(config, &path_dedot::CWD, None)?;
         return Ok(PyprojectDiscovery::Fixed(settings));
     }
 
@@ -68,6 +68,6 @@ pub fn resolve(
     // as the "default" settings.)
     let mut config = Configuration::default();
     overrides.process_config(&mut config);
-    let settings = AllSettings::from_configuration(config, &path_dedot::CWD)?;
+    let settings = AllSettings::from_configuration(config, &path_dedot::CWD, None)?;
     Ok(PyprojectDiscovery::Hierarchical(settings))
 }