ruff_db: rename Diagnostic to OldDiagnosticTrait

This trait should eventually go away, so we rename it (and supporting
types) to make room for a new concrete `Diagnostic` type.

This commit is just the rename. In the next commit, we'll move it to a
different module.

crates/red_knot/src/main.rs

@@ -15,7 +15,7 @@ use red_knot_project::watch::ProjectWatcher;
 use red_knot_project::{watch, Db};
 use red_knot_project::{ProjectDatabase, ProjectMetadata};
 use red_knot_server::run_server;
-use ruff_db::diagnostic::{Diagnostic, DisplayDiagnosticConfig, Severity};
+use ruff_db::diagnostic::{DisplayDiagnosticConfig, OldDiagnosticTrait, Severity};
 use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
 use salsa::plumbing::ZalsaDatabase;
 
@@ -354,8 +354,7 @@ enum MainLoopMessage {
     CheckWorkspace,
     CheckCompleted {
         /// The diagnostics that were found during the check.
-        result: Vec<Box<dyn Diagnostic>>,
+        result: Vec<Box<dyn OldDiagnosticTrait>>,
-
         revision: u64,
     },
     ApplyChanges(Vec<watch::ChangeEvent>),

crates/red_knot_project/src/db.rs

@@ -5,7 +5,7 @@ use crate::DEFAULT_LINT_REGISTRY;
 use crate::{Project, ProjectMetadata};
 use red_knot_python_semantic::lint::{LintRegistry, RuleSelection};
 use red_knot_python_semantic::{Db as SemanticDb, Program};
-use ruff_db::diagnostic::Diagnostic;
+use ruff_db::diagnostic::OldDiagnosticTrait;
 use ruff_db::files::{File, Files};
 use ruff_db::system::System;
 use ruff_db::vendored::VendoredFileSystem;
@@ -55,11 +55,11 @@ impl ProjectDatabase {
     }
 
     /// Checks all open files in the project and its dependencies.
-    pub fn check(&self) -> Result<Vec<Box<dyn Diagnostic>>, Cancelled> {
+    pub fn check(&self) -> Result<Vec<Box<dyn OldDiagnosticTrait>>, Cancelled> {
         self.with_db(|db| db.project().check(db))
     }
 
-    pub fn check_file(&self, file: File) -> Result<Vec<Box<dyn Diagnostic>>, Cancelled> {
+    pub fn check_file(&self, file: File) -> Result<Vec<Box<dyn OldDiagnosticTrait>>, Cancelled> {
         let _span = tracing::debug_span!("check_file", file=%file.path(self)).entered();
 
         self.with_db(|db| self.project().check_file(db, file))

crates/red_knot_project/src/lib.rs

@@ -9,7 +9,7 @@ pub use metadata::{ProjectDiscoveryError, ProjectMetadata};
 use red_knot_python_semantic::lint::{LintRegistry, LintRegistryBuilder, RuleSelection};
 use red_knot_python_semantic::register_lints;
 use red_knot_python_semantic::types::check_types;
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, ParseDiagnostic, Severity, Span};
+use ruff_db::diagnostic::{DiagnosticId, OldDiagnosticTrait, ParseDiagnostic, Severity, Span};
 use ruff_db::files::File;
 use ruff_db::parsed::parsed_module;
 use ruff_db::source::{source_text, SourceTextError};
@@ -163,22 +163,22 @@ impl Project {
     }
 
     /// Checks all open files in the project and its dependencies.
-    pub(crate) fn check(self, db: &ProjectDatabase) -> Vec<Box<dyn Diagnostic>> {
+    pub(crate) fn check(self, db: &ProjectDatabase) -> Vec<Box<dyn OldDiagnosticTrait>> {
         let project_span = tracing::debug_span!("Project::check");
         let _span = project_span.enter();
 
         tracing::debug!("Checking project '{name}'", name = self.name(db));
 
-        let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
+        let mut diagnostics: Vec<Box<dyn OldDiagnosticTrait>> = Vec::new();
         diagnostics.extend(self.settings_diagnostics(db).iter().map(|diagnostic| {
-            let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+            let diagnostic: Box<dyn OldDiagnosticTrait> = Box::new(diagnostic.clone());
             diagnostic
         }));
 
         let files = ProjectFiles::new(db, self);
 
         diagnostics.extend(files.diagnostics().iter().cloned().map(|diagnostic| {
-            let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic);
+            let diagnostic: Box<dyn OldDiagnosticTrait> = Box::new(diagnostic);
             diagnostic
         }));
 
@@ -207,12 +207,12 @@ impl Project {
         Arc::into_inner(result).unwrap().into_inner().unwrap()
     }
 
-    pub(crate) fn check_file(self, db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
+    pub(crate) fn check_file(self, db: &dyn Db, file: File) -> Vec<Box<dyn OldDiagnosticTrait>> {
         let mut file_diagnostics: Vec<_> = self
             .settings_diagnostics(db)
             .iter()
             .map(|diagnostic| {
-                let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+                let diagnostic: Box<dyn OldDiagnosticTrait> = Box::new(diagnostic.clone());
                 diagnostic
             })
             .collect();
@@ -397,8 +397,8 @@ impl Project {
     }
 }
 
-fn check_file_impl(db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
+fn check_file_impl(db: &dyn Db, file: File) -> Vec<Box<dyn OldDiagnosticTrait>> {
-    let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
+    let mut diagnostics: Vec<Box<dyn OldDiagnosticTrait>> = Vec::new();
 
     // Abort checking if there are IO errors.
     let source = source_text(db.upcast(), file);
@@ -413,12 +413,13 @@ fn check_file_impl(db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
 
     let parsed = parsed_module(db.upcast(), file);
     diagnostics.extend(parsed.errors().iter().map(|error| {
-        let diagnostic: Box<dyn Diagnostic> = Box::new(ParseDiagnostic::new(file, error.clone()));
+        let diagnostic: Box<dyn OldDiagnosticTrait> =
+            Box::new(ParseDiagnostic::new(file, error.clone()));
         diagnostic
     }));
 
     diagnostics.extend(check_types(db.upcast(), file).iter().map(|diagnostic| {
-        let boxed: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+        let boxed: Box<dyn OldDiagnosticTrait> = Box::new(diagnostic.clone());
         boxed
     }));
 
@@ -492,7 +493,7 @@ pub struct IOErrorDiagnostic {
     error: IOErrorKind,
 }
 
-impl Diagnostic for IOErrorDiagnostic {
+impl OldDiagnosticTrait for IOErrorDiagnostic {
     fn id(&self) -> DiagnosticId {
         DiagnosticId::Io
     }
@@ -524,7 +525,7 @@ mod tests {
     use crate::db::tests::TestDb;
     use crate::{check_file_impl, ProjectMetadata};
     use red_knot_python_semantic::types::check_types;
-    use ruff_db::diagnostic::Diagnostic;
+    use ruff_db::diagnostic::OldDiagnosticTrait;
     use ruff_db::files::system_path_to_file;
     use ruff_db::source::source_text;
     use ruff_db::system::{DbWithTestSystem, SystemPath, SystemPathBuf};

crates/red_knot_project/src/metadata/options.rs

@@ -2,7 +2,7 @@ use crate::metadata::value::{RangedValue, RelativePathBuf, ValueSource, ValueSou
 use crate::Db;
 use red_knot_python_semantic::lint::{GetLintError, Level, LintSource, RuleSelection};
 use red_knot_python_semantic::{ProgramSettings, PythonPath, PythonPlatform, SearchPathSettings};
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity, Span};
+use ruff_db::diagnostic::{DiagnosticId, OldDiagnosticTrait, Severity, Span};
 use ruff_db::files::system_path_to_file;
 use ruff_db::system::{System, SystemPath};
 use ruff_macros::Combine;
@@ -376,7 +376,7 @@ impl OptionDiagnostic {
     }
 }
 
-impl Diagnostic for OptionDiagnostic {
+impl OldDiagnosticTrait for OptionDiagnostic {
     fn id(&self) -> DiagnosticId {
         self.id
     }

crates/red_knot_python_semantic/src/types/call/bind.rs

@@ -6,7 +6,7 @@ use crate::types::diagnostic::{
 };
 use crate::types::signatures::Parameter;
 use crate::types::{todo_type, CallableType, UnionType};
-use ruff_db::diagnostic::{SecondaryDiagnosticMessage, Span};
+use ruff_db::diagnostic::{OldSecondaryDiagnosticMessage, Span};
 use ruff_python_ast as ast;
 use ruff_text_size::Ranged;
 
@@ -388,7 +388,7 @@ impl<'db> CallBindingError<'db> {
                 if let Some(span) =
                     Self::parameter_span_from_index(context.db(), callable_ty, parameter.index)
                 {
-                    messages.push(SecondaryDiagnosticMessage::new(
+                    messages.push(OldSecondaryDiagnosticMessage::new(
                         span,
                         "parameter declared in function definition here",
                     ));

crates/red_knot_python_semantic/src/types/context.rs

@@ -2,7 +2,7 @@ use std::fmt;
 
 use drop_bomb::DebugDropBomb;
 use ruff_db::{
-    diagnostic::{DiagnosticId, SecondaryDiagnosticMessage, Severity},
+    diagnostic::{DiagnosticId, OldSecondaryDiagnosticMessage, Severity},
     files::File,
 };
 use ruff_text_size::{Ranged, TextRange};
@@ -84,7 +84,7 @@ impl<'db> InferContext<'db> {
         lint: &'static LintMetadata,
         ranged: T,
         message: fmt::Arguments,
-        secondary_messages: Vec<SecondaryDiagnosticMessage>,
+        secondary_messages: Vec<OldSecondaryDiagnosticMessage>,
     ) where
         T: Ranged,
     {
@@ -136,7 +136,7 @@ impl<'db> InferContext<'db> {
         id: DiagnosticId,
         severity: Severity,
         message: fmt::Arguments,
-        secondary_messages: Vec<SecondaryDiagnosticMessage>,
+        secondary_messages: Vec<OldSecondaryDiagnosticMessage>,
     ) where
         T: Ranged,
     {

crates/red_knot_python_semantic/src/types/diagnostic.rs

@@ -8,7 +8,9 @@ use crate::types::string_annotation::{
 };
 use crate::types::{ClassLiteralType, KnownInstanceType, Type};
 use crate::{declare_lint, Db};
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, SecondaryDiagnosticMessage, Severity, Span};
+use ruff_db::diagnostic::{
+    DiagnosticId, OldDiagnosticTrait, OldSecondaryDiagnosticMessage, Severity, Span,
+};
 use ruff_db::files::File;
 use ruff_python_ast::{self as ast, AnyNodeRef};
 use ruff_text_size::TextRange;
@@ -828,7 +830,7 @@ pub struct TypeCheckDiagnostic {
     pub(crate) range: TextRange,
     pub(crate) severity: Severity,
     pub(crate) file: File,
-    pub(crate) secondary_messages: Vec<SecondaryDiagnosticMessage>,
+    pub(crate) secondary_messages: Vec<OldSecondaryDiagnosticMessage>,
 }
 
 impl TypeCheckDiagnostic {
@@ -845,7 +847,7 @@ impl TypeCheckDiagnostic {
     }
 }
 
-impl Diagnostic for TypeCheckDiagnostic {
+impl OldDiagnosticTrait for TypeCheckDiagnostic {
     fn id(&self) -> DiagnosticId {
         self.id
     }
@@ -858,7 +860,7 @@ impl Diagnostic for TypeCheckDiagnostic {
         Some(Span::from(self.file).with_range(self.range))
     }
 
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         &self.secondary_messages
     }
 

crates/red_knot_server/src/server/api/requests/diagnostic.rs

@@ -72,7 +72,7 @@ fn compute_diagnostics(snapshot: &DocumentSnapshot, db: &ProjectDatabase) -> Vec
 
 fn to_lsp_diagnostic(
     db: &dyn Db,
-    diagnostic: &dyn ruff_db::diagnostic::Diagnostic,
+    diagnostic: &dyn ruff_db::diagnostic::OldDiagnosticTrait,
     encoding: crate::PositionEncoding,
 ) -> Diagnostic {
     let range = if let Some(span) = diagnostic.span() {

crates/red_knot_test/src/diagnostic.rs

@@ -2,7 +2,7 @@
 //!
 //! We don't assume that we will get the diagnostics in source order.
 
-use ruff_db::diagnostic::Diagnostic;
+use ruff_db::diagnostic::OldDiagnosticTrait;
 use ruff_source_file::{LineIndex, OneIndexed};
 use std::ops::{Deref, Range};
 
@@ -19,7 +19,7 @@ pub(crate) struct SortedDiagnostics<T> {
 
 impl<T> SortedDiagnostics<T>
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     pub(crate) fn new(diagnostics: impl IntoIterator<Item = T>, line_index: &LineIndex) -> Self {
         let mut diagnostics: Vec<_> = diagnostics
@@ -99,7 +99,7 @@ pub(crate) struct LineDiagnosticsIterator<'a, T> {
 
 impl<'a, T> Iterator for LineDiagnosticsIterator<'a, T>
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     type Item = LineDiagnostics<'a, T>;
 
@@ -115,7 +115,7 @@ where
     }
 }
 
-impl<T> std::iter::FusedIterator for LineDiagnosticsIterator<'_, T> where T: Diagnostic {}
+impl<T> std::iter::FusedIterator for LineDiagnosticsIterator<'_, T> where T: OldDiagnosticTrait {}
 
 /// All diagnostics that start on a single line of source code in one embedded Python file.
 #[derive(Debug)]
@@ -144,7 +144,7 @@ struct DiagnosticWithLine<T> {
 #[cfg(test)]
 mod tests {
     use crate::db::Db;
-    use crate::diagnostic::Diagnostic;
+    use crate::diagnostic::OldDiagnosticTrait;
     use ruff_db::diagnostic::{DiagnosticId, LintName, Severity, Span};
     use ruff_db::files::{system_path_to_file, File};
     use ruff_db::source::line_index;
@@ -190,7 +190,7 @@ mod tests {
         file: File,
     }
 
-    impl Diagnostic for DummyDiagnostic {
+    impl OldDiagnosticTrait for DummyDiagnostic {
         fn id(&self) -> DiagnosticId {
             DiagnosticId::Lint(LintName::of("dummy"))
         }

crates/red_knot_test/src/lib.rs

@@ -5,7 +5,7 @@ use colored::Colorize;
 use parser as test_parser;
 use red_knot_python_semantic::types::check_types;
 use red_knot_python_semantic::{Program, ProgramSettings, PythonPath, SearchPathSettings};
-use ruff_db::diagnostic::{Diagnostic, DisplayDiagnosticConfig, ParseDiagnostic};
+use ruff_db::diagnostic::{DisplayDiagnosticConfig, OldDiagnosticTrait, ParseDiagnostic};
 use ruff_db::files::{system_path_to_file, File, Files};
 use ruff_db::panic::catch_unwind;
 use ruff_db::parsed::parsed_module;
@@ -200,7 +200,7 @@ fn run_test(
                 .iter()
                 .cloned()
                 .map(|error| {
-                    let diagnostic: Box<dyn Diagnostic> =
+                    let diagnostic: Box<dyn OldDiagnosticTrait> =
                         Box::new(ParseDiagnostic::new(test_file.file, error));
                     diagnostic
                 })
@@ -234,7 +234,7 @@ fn run_test(
                 }
             };
             diagnostics.extend(type_diagnostics.into_iter().map(|diagnostic| {
-                let diagnostic: Box<dyn Diagnostic> = Box::new((*diagnostic).clone());
+                let diagnostic: Box<dyn OldDiagnosticTrait> = Box::new((*diagnostic).clone());
                 diagnostic
             }));
 
@@ -299,7 +299,7 @@ struct TestFile {
     backtick_offsets: Vec<BacktickOffsets>,
 }
 
-fn create_diagnostic_snapshot<D: Diagnostic>(
+fn create_diagnostic_snapshot<D: OldDiagnosticTrait>(
     db: &mut db::Db,
     relative_fixture_path: &Utf8Path,
     test: &parser::MarkdownTest,

crates/red_knot_test/src/matcher.rs

@@ -1,10 +1,10 @@
-//! Match [`Diagnostic`]s against assertions and produce test failure messages for any
+//! Match [`OldDiagnosticTrait`]s against assertions and produce test failure
-//! mismatches.
+//! messages for any mismatches.
 use crate::assertion::{InlineFileAssertions, ParsedAssertion, UnparsedAssertion};
 use crate::db::Db;
 use crate::diagnostic::SortedDiagnostics;
 use colored::Colorize;
-use ruff_db::diagnostic::{Diagnostic, DiagnosticAsStrError, DiagnosticId};
+use ruff_db::diagnostic::{DiagnosticAsStrError, DiagnosticId, OldDiagnosticTrait};
 use ruff_db::files::File;
 use ruff_db::source::{line_index, source_text, SourceText};
 use ruff_source_file::{LineIndex, OneIndexed};
@@ -53,7 +53,7 @@ pub(super) fn match_file<T>(
     diagnostics: impl IntoIterator<Item = T>,
 ) -> Result<(), FailuresByLine>
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     // Parse assertions from comments in the file, and get diagnostics from the file; both
     // ordered by line number.
@@ -155,7 +155,7 @@ impl Unmatched for ParsedAssertion<'_> {
     }
 }
 
-fn maybe_add_undefined_reveal_clarification<T: Diagnostic>(
+fn maybe_add_undefined_reveal_clarification<T: OldDiagnosticTrait>(
     diagnostic: &T,
     original: std::fmt::Arguments,
 ) -> String {
@@ -171,7 +171,7 @@ fn maybe_add_undefined_reveal_clarification<T: Diagnostic>(
 
 impl<T> Unmatched for T
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     fn unmatched(&self) -> String {
         let id = self.id();
@@ -188,7 +188,7 @@ where
 
 impl<T> UnmatchedWithColumn for T
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     fn unmatched_with_column(&self, column: OneIndexed) -> String {
         let id = self.id();
@@ -226,10 +226,12 @@ impl Matcher {
         }
     }
 
-    /// Check a slice of [`Diagnostic`]s against a slice of [`UnparsedAssertion`]s.
+    /// Check a slice of [`OldDiagnosticTrait`]s against a slice of
+    /// [`UnparsedAssertion`]s.
     ///
-    /// Return vector of [`Unmatched`] for any unmatched diagnostics or assertions.
+    /// Return vector of [`Unmatched`] for any unmatched diagnostics or
-    fn match_line<'a, 'b, T: Diagnostic + 'a>(
+    /// assertions.
+    fn match_line<'a, 'b, T: OldDiagnosticTrait + 'a>(
         &self,
         diagnostics: &'a [T],
         assertions: &'a [UnparsedAssertion<'b>],
@@ -261,7 +263,7 @@ impl Matcher {
         }
     }
 
-    fn column<T: Diagnostic>(&self, diagnostic: &T) -> OneIndexed {
+    fn column<T: OldDiagnosticTrait>(&self, diagnostic: &T) -> OneIndexed {
         diagnostic
             .span()
             .and_then(|span| span.range())
@@ -273,7 +275,7 @@ impl Matcher {
             .unwrap_or(OneIndexed::from_zero_indexed(0))
     }
 
-    /// Check if `assertion` matches any [`Diagnostic`]s in `unmatched`.
+    /// Check if `assertion` matches any [`OldDiagnosticTrait`]s in `unmatched`.
     ///
     /// If so, return `true` and remove the matched diagnostics from `unmatched`. Otherwise, return
     /// `false`.
@@ -283,7 +285,11 @@ impl Matcher {
     ///
     /// A `Revealed` assertion must match a revealed-type diagnostic, and may also match an
     /// undefined-reveal diagnostic, if present.
-    fn matches<T: Diagnostic>(&self, assertion: &ParsedAssertion, unmatched: &mut Vec<&T>) -> bool {
+    fn matches<T: OldDiagnosticTrait>(
+        &self,
+        assertion: &ParsedAssertion,
+        unmatched: &mut Vec<&T>,
+    ) -> bool {
         match assertion {
             ParsedAssertion::Error(error) => {
                 let position = unmatched.iter().position(|diagnostic| {
@@ -341,7 +347,7 @@ impl Matcher {
 #[cfg(test)]
 mod tests {
     use super::FailuresByLine;
-    use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity, Span};
+    use ruff_db::diagnostic::{DiagnosticId, OldDiagnosticTrait, Severity, Span};
     use ruff_db::files::{system_path_to_file, File};
     use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
     use ruff_python_trivia::textwrap::dedent;
@@ -383,7 +389,7 @@ mod tests {
         file: File,
     }
 
-    impl Diagnostic for TestDiagnostic {
+    impl OldDiagnosticTrait for TestDiagnostic {
         fn id(&self) -> DiagnosticId {
             self.id
         }

crates/red_knot_wasm/src/lib.rs

@@ -7,7 +7,7 @@ use red_knot_project::metadata::options::{EnvironmentOptions, Options};
 use red_knot_project::metadata::value::RangedValue;
 use red_knot_project::ProjectMetadata;
 use red_knot_project::{Db, ProjectDatabase};
-use ruff_db::diagnostic::{Diagnostic, DisplayDiagnosticConfig};
+use ruff_db::diagnostic::{DisplayDiagnosticConfig, OldDiagnosticTrait};
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::system::walk_directory::WalkDirectoryBuilder;
 use ruff_db::system::{

crates/ruff_benchmark/benches/red_knot.rs

@@ -10,7 +10,7 @@ use red_knot_project::watch::{ChangeEvent, ChangedKind};
 use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
 use ruff_benchmark::criterion::{criterion_group, criterion_main, BatchSize, Criterion};
 use ruff_benchmark::TestFile;
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity};
+use ruff_db::diagnostic::{DiagnosticId, OldDiagnosticTrait, Severity};
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::source::source_text;
 use ruff_db::system::{MemoryFileSystem, SystemPath, SystemPathBuf, TestSystem};
@@ -223,7 +223,7 @@ fn benchmark_cold(criterion: &mut Criterion) {
 }
 
 #[track_caller]
-fn assert_diagnostics(db: &dyn Db, diagnostics: &[Box<dyn Diagnostic>]) {
+fn assert_diagnostics(db: &dyn Db, diagnostics: &[Box<dyn OldDiagnosticTrait>]) {
     let normalized: Vec<_> = diagnostics
         .iter()
         .map(|diagnostic| {

crates/ruff_db/src/diagnostic.rs

@@ -162,7 +162,7 @@ impl std::fmt::Display for DiagnosticId {
     }
 }
 
-pub trait Diagnostic: Send + Sync + std::fmt::Debug {
+pub trait OldDiagnosticTrait: Send + Sync + std::fmt::Debug {
     fn id(&self) -> DiagnosticId;
 
     fn message(&self) -> Cow<str>;
@@ -175,7 +175,7 @@ pub trait Diagnostic: Send + Sync + std::fmt::Debug {
 
     /// Returns an optional sequence of "secondary" messages (with spans) to
     /// include in the rendering of this diagnostic.
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         &[]
     }
 
@@ -185,11 +185,11 @@ pub trait Diagnostic: Send + Sync + std::fmt::Debug {
         &'diag self,
         db: &'db dyn Db,
         config: &'config DisplayDiagnosticConfig,
-    ) -> DisplayDiagnostic<'db, 'diag, 'config>
+    ) -> OldDisplayDiagnostic<'db, 'diag, 'config>
     where
         Self: Sized,
     {
-        DisplayDiagnostic {
+        OldDisplayDiagnostic {
             db,
             diagnostic: self,
             config,
@@ -199,14 +199,14 @@ pub trait Diagnostic: Send + Sync + std::fmt::Debug {
 
 /// A single secondary message assigned to a `Diagnostic`.
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub struct SecondaryDiagnosticMessage {
+pub struct OldSecondaryDiagnosticMessage {
     span: Span,
     message: String,
 }
 
-impl SecondaryDiagnosticMessage {
+impl OldSecondaryDiagnosticMessage {
-    pub fn new(span: Span, message: impl Into<String>) -> SecondaryDiagnosticMessage {
+    pub fn new(span: Span, message: impl Into<String>) -> OldSecondaryDiagnosticMessage {
-        SecondaryDiagnosticMessage {
+        OldSecondaryDiagnosticMessage {
             span,
             message: message.into(),
         }
@@ -298,13 +298,13 @@ impl DisplayDiagnosticConfig {
     }
 }
 
-pub struct DisplayDiagnostic<'db, 'diag, 'config> {
+pub struct OldDisplayDiagnostic<'db, 'diag, 'config> {
     db: &'db dyn Db,
-    diagnostic: &'diag dyn Diagnostic,
+    diagnostic: &'diag dyn OldDiagnosticTrait,
     config: &'config DisplayDiagnosticConfig,
 }
 
-impl std::fmt::Display for DisplayDiagnostic<'_, '_, '_> {
+impl std::fmt::Display for OldDisplayDiagnostic<'_, '_, '_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let render = |f: &mut std::fmt::Formatter, message| {
             let renderer = if self.config.color {
@@ -461,9 +461,9 @@ impl Annotation {
     }
 }
 
-impl<T> Diagnostic for Box<T>
+impl<T> OldDiagnosticTrait for Box<T>
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     fn id(&self) -> DiagnosticId {
         (**self).id()
@@ -477,7 +477,7 @@ where
         (**self).span()
     }
 
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         (**self).secondary_messages()
     }
 
@@ -486,9 +486,9 @@ where
     }
 }
 
-impl<T> Diagnostic for std::sync::Arc<T>
+impl<T> OldDiagnosticTrait for std::sync::Arc<T>
 where
-    T: Diagnostic,
+    T: OldDiagnosticTrait,
 {
     fn id(&self) -> DiagnosticId {
         (**self).id()
@@ -502,7 +502,7 @@ where
         (**self).span()
     }
 
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         (**self).secondary_messages()
     }
 
@@ -511,7 +511,7 @@ where
     }
 }
 
-impl Diagnostic for Box<dyn Diagnostic> {
+impl OldDiagnosticTrait for Box<dyn OldDiagnosticTrait> {
     fn id(&self) -> DiagnosticId {
         (**self).id()
     }
@@ -524,7 +524,7 @@ impl Diagnostic for Box<dyn Diagnostic> {
         (**self).span()
     }
 
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         (**self).secondary_messages()
     }
 
@@ -533,7 +533,7 @@ impl Diagnostic for Box<dyn Diagnostic> {
     }
 }
 
-impl Diagnostic for &'_ dyn Diagnostic {
+impl OldDiagnosticTrait for &'_ dyn OldDiagnosticTrait {
     fn id(&self) -> DiagnosticId {
         (**self).id()
     }
@@ -546,7 +546,7 @@ impl Diagnostic for &'_ dyn Diagnostic {
         (**self).span()
     }
 
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         (**self).secondary_messages()
     }
 
@@ -555,7 +555,7 @@ impl Diagnostic for &'_ dyn Diagnostic {
     }
 }
 
-impl Diagnostic for std::sync::Arc<dyn Diagnostic> {
+impl OldDiagnosticTrait for std::sync::Arc<dyn OldDiagnosticTrait> {
     fn id(&self) -> DiagnosticId {
         (**self).id()
     }
@@ -568,7 +568,7 @@ impl Diagnostic for std::sync::Arc<dyn Diagnostic> {
         (**self).span()
     }
 
-    fn secondary_messages(&self) -> &[SecondaryDiagnosticMessage] {
+    fn secondary_messages(&self) -> &[OldSecondaryDiagnosticMessage] {
         (**self).secondary_messages()
     }
 
@@ -589,7 +589,7 @@ impl ParseDiagnostic {
     }
 }
 
-impl Diagnostic for ParseDiagnostic {
+impl OldDiagnosticTrait for ParseDiagnostic {
     fn id(&self) -> DiagnosticId {
         DiagnosticId::InvalidSyntax
     }