Update Rust toolchain to 1.88 and MSRV to 1.86

Cargo.toml

@@ -5,7 +5,7 @@ resolver = "2"
 [workspace.package]
 # Please update rustfmt.toml when bumping the Rust edition
 edition = "2024"
-rust-version = "1.85"
+rust-version = "1.86"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -227,6 +227,7 @@ unnecessary_debug_formatting = "allow"  # too many instances, the display also d
 # Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
+ignore_without_reason = "allow" # Too many exsisting instances, and there's no auto fix.
 print_stdout = "warn"
 print_stderr = "warn"
 dbg_macro = "warn"

crates/ruff_annotate_snippets/src/renderer/display_list.rs

@@ -821,11 +821,7 @@ impl DisplaySourceAnnotation<'_> {
     // Length of this annotation as displayed in the stderr output
     fn len(&self) -> usize {
         // Account for usize underflows
-        if self.range.1 > self.range.0 {
-            self.range.1 - self.range.0
-        } else {
-            self.range.0 - self.range.1
-        }
+        self.range.1.abs_diff(self.range.0)
     }
 
     fn takes_space(&self) -> bool {

crates/ruff_db/src/diagnostic/render.rs

@@ -637,6 +637,22 @@ pub trait FileResolver {
     fn input(&self, file: File) -> Input;
 }
 
+impl<T> FileResolver for T
+where
+    T: Db,
+{
+    fn path(&self, file: File) -> &str {
+        relativize_path(self.system().current_directory(), file.path(self).as_str())
+    }
+
+    fn input(&self, file: File) -> Input {
+        Input {
+            text: source_text(self, file),
+            line_index: line_index(self, file),
+        }
+    }
+}
+
 impl FileResolver for &dyn Db {
     fn path(&self, file: File) -> &str {
         relativize_path(self.system().current_directory(), file.path(*self).as_str())
@@ -708,7 +724,6 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
 #[cfg(test)]
 mod tests {
 
-    use crate::Upcast;
     use crate::diagnostic::{Annotation, DiagnosticId, Severity, Span};
     use crate::files::system_path_to_file;
     use crate::system::{DbWithWritableSystem, SystemPath};
@@ -2221,7 +2236,7 @@ watermelon
         ///
         /// (This will set the "printed" flag on `Diagnostic`.)
         fn render(&self, diag: &Diagnostic) -> String {
-            diag.display(&self.db.upcast(), &self.config).to_string()
+            diag.display(&self.db, &self.config).to_string()
         }
     }
 

crates/ruff_db/src/lib.rs

@@ -36,12 +36,6 @@ pub trait Db: salsa::Database {
     fn python_version(&self) -> PythonVersion;
 }
 
-/// Trait for upcasting a reference to a base trait object.
-pub trait Upcast<T: ?Sized> {
-    fn upcast(&self) -> &T;
-    fn upcast_mut(&mut self) -> &mut T;
-}
-
 /// Returns the maximum number of tasks that ty is allowed
 /// to process in parallel.
 ///
@@ -76,11 +70,11 @@ pub trait RustDoc {
 mod tests {
     use std::sync::{Arc, Mutex};
 
+    use crate::Db;
     use crate::files::Files;
     use crate::system::TestSystem;
     use crate::system::{DbWithTestSystem, System};
     use crate::vendored::VendoredFileSystem;
-    use crate::{Db, Upcast};
 
     type Events = Arc<Mutex<Vec<salsa::Event>>>;
 
@@ -153,15 +147,6 @@ mod tests {
         }
     }
 
-    impl Upcast<dyn Db> for TestDb {
-        fn upcast(&self) -> &(dyn Db + 'static) {
-            self
-        }
-        fn upcast_mut(&mut self) -> &mut (dyn Db + 'static) {
-            self
-        }
-    }
-
     impl DbWithTestSystem for TestDb {
         fn test_system(&self) -> &TestSystem {
             &self.system

crates/ruff_db/src/system/walk_directory.rs

@@ -212,7 +212,7 @@ impl Display for Error {
                 path: Some(path),
                 err,
             } => {
-                write!(f, "IO error for operation on {}: {}", path, err)
+                write!(f, "IO error for operation on {path}: {err}")
             }
             ErrorKind::Io { path: None, err } => err.fmt(f),
             ErrorKind::NonUtf8Path { path } => {

crates/ruff_graph/src/db.rs

@@ -2,10 +2,10 @@ use anyhow::{Context, Result};
 use std::sync::Arc;
 use zip::CompressionMethod;
 
+use ruff_db::Db as SourceDb;
 use ruff_db::files::{File, Files};
 use ruff_db::system::{OsSystem, System, SystemPathBuf};
 use ruff_db::vendored::{VendoredFileSystem, VendoredFileSystemBuilder};
-use ruff_db::{Db as SourceDb, Upcast};
 use ruff_python_ast::PythonVersion;
 use ty_python_semantic::lint::{LintRegistry, RuleSelection};
 use ty_python_semantic::{
@@ -66,15 +66,6 @@ impl ModuleDb {
     }
 }
 
-impl Upcast<dyn SourceDb> for ModuleDb {
-    fn upcast(&self) -> &(dyn SourceDb + 'static) {
-        self
-    }
-    fn upcast_mut(&mut self) -> &mut (dyn SourceDb + 'static) {
-        self
-    }
-}
-
 #[salsa::db]
 impl SourceDb for ModuleDb {
     fn vendored(&self) -> &VendoredFileSystem {

crates/ruff_index/src/vec.rs

@@ -191,6 +191,6 @@ where
     #[expect(unsafe_code)]
     unsafe fn maybe_update(old_pointer: *mut Self, new_value: Self) -> bool {
         let old_vec: &mut IndexVec<I, T> = unsafe { &mut *old_pointer };
-        unsafe { salsa::Update::maybe_update(&mut old_vec.raw, new_value.raw) }
+        unsafe { salsa::Update::maybe_update(&raw mut old_vec.raw, new_value.raw) }
     }
 }

crates/ruff_python_formatter/src/db.rs

@@ -1,9 +1,9 @@
-use ruff_db::{Db as SourceDb, Upcast, files::File};
+use ruff_db::{Db as SourceDb, files::File};
 
 use crate::PyFormatOptions;
 
 #[salsa::db]
-pub trait Db: SourceDb + Upcast<dyn SourceDb> {
+pub trait Db: SourceDb {
     /// Returns the formatting options
     fn format_options(&self, file: File) -> PyFormatOptions;
 }

crates/ruff_python_formatter/src/lib.rs

@@ -165,14 +165,14 @@ where
 pub fn formatted_file(db: &dyn Db, file: File) -> Result<Option<String>, FormatModuleError> {
     let options = db.format_options(file);
 
-    let parsed = parsed_module(db.upcast(), file).load(db.upcast());
+    let parsed = parsed_module(db, file).load(db);
 
     if let Some(first) = parsed.errors().first() {
         return Err(FormatModuleError::ParseError(first.clone()));
     }
 
     let comment_ranges = CommentRanges::from(parsed.tokens());
-    let source = source_text(db.upcast(), file);
+    let source = source_text(db, file);
 
     let formatted = format_node(&parsed, &comment_ranges, &source, options)?;
     let printed = formatted.print()?;

crates/ruff_server/src/server/schedule/thread/priority.rs

@@ -228,7 +228,11 @@ mod imp {
         let mut qos_class_raw = libc::qos_class_t::QOS_CLASS_UNSPECIFIED;
         #[expect(unsafe_code)]
         let code = unsafe {
-            libc::pthread_get_qos_class_np(current_thread, &mut qos_class_raw, std::ptr::null_mut())
+            libc::pthread_get_qos_class_np(
+                current_thread,
+                &raw mut qos_class_raw,
+                std::ptr::null_mut(),
+            )
         };
 
         if code != 0 {

crates/ty/src/lib.rs

@@ -19,8 +19,8 @@ use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
 use rayon::ThreadPoolBuilder;
 use ruff_db::diagnostic::{Diagnostic, DisplayDiagnosticConfig, Severity};
+use ruff_db::max_parallelism;
 use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
-use ruff_db::{Upcast, max_parallelism};
 use salsa::plumbing::ZalsaDatabase;
 use ty_project::metadata::options::ProjectOptionsOverrides;
 use ty_project::watch::ProjectWatcher;
@@ -308,11 +308,7 @@ impl MainLoop {
                             let diagnostics_count = result.len();
 
                             for diagnostic in result {
-                                write!(
-                                    stdout,
-                                    "{}",
-                                    diagnostic.display(&db.upcast(), &display_config)
-                                )?;
+                                write!(stdout, "{}", diagnostic.display(db, &display_config))?;
 
                                 max_severity = max_severity.max(diagnostic.severity());
                             }