7 files changed, 85 insertions, 75 deletions

diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 1e5ea4617..90574cb35 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -10,7 +10,10 @@ mod field_shorthand;
 use std::cell::RefCell;
 
 use base_db::SourceDatabase;
-use hir::{diagnostics::DiagnosticSinkBuilder, Semantics};
+use hir::{
+    diagnostics::{Diagnostic as _, DiagnosticSinkBuilder},
+    Semantics,
+};
 use ide_db::RootDatabase;
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
@@ -31,6 +34,25 @@ pub struct Diagnostic {
     pub range: TextRange,
     pub severity: Severity,
     pub fix: Option<Fix>,
+    pub unused: bool,
+}
+
+impl Diagnostic {
+    fn error(range: TextRange, message: String) -> Self {
+        Self { message, range, severity: Severity::Error, fix: None, unused: false }
+    }
+
+    fn hint(range: TextRange, message: String) -> Self {
+        Self { message, range, severity: Severity::WeakWarning, fix: None, unused: false }
+    }
+
+    fn with_fix(self, fix: Option<Fix>) -> Self {
+        Self { fix, ..self }
+    }
+
+    fn with_unused(self, unused: bool) -> Self {
+        Self { unused, ..self }
+    }
 }
 
 #[derive(Debug)]
@@ -71,13 +93,13 @@ pub(crate) fn diagnostics(
     let mut res = Vec::new();
 
     // [#34344] Only take first 128 errors to prevent slowing down editor/ide, the number 128 is chosen arbitrarily.
-    res.extend(parse.errors().iter().take(128).map(|err| Diagnostic {
-        // name: None,
-        range: err.range(),
-        message: format!("Syntax Error: {}", err),
-        severity: Severity::Error,
-        fix: None,
-    }));
+    res.extend(
+        parse
+            .errors()
+            .iter()
+            .take(128)
+            .map(|err| Diagnostic::error(err.range(), format!("Syntax Error: {}", err))),
+    );
 
     for node in parse.tree().syntax().descendants() {
         check_unnecessary_braces_in_use_statement(&mut res, file_id, &node);
@@ -100,6 +122,13 @@ pub(crate) fn diagnostics(
         .on::<hir::diagnostics::IncorrectCase, _>(|d| {
             res.borrow_mut().push(warning_with_fix(d, &sema));
         })
+        .on::<hir::diagnostics::InactiveCode, _>(|d| {
+            // Override severity and mark as unused.
+            res.borrow_mut().push(
+                Diagnostic::hint(sema.diagnostics_display_range(d).range, d.message())
+                    .with_unused(true),
+            );
+        })
         // Only collect experimental diagnostics when they're enabled.
         .filter(|diag| !(diag.is_experimental() && config.disable_experimental))
         .filter(|diag| !config.disabled.contains(diag.code().as_str()));
@@ -108,13 +137,8 @@ pub(crate) fn diagnostics(
     let mut sink = sink_builder
         // Diagnostics not handled above get no fix and default treatment.
         .build(|d| {
-            res.borrow_mut().push(Diagnostic {
-                // name: Some(d.name().into()),
-                message: d.message(),
-                range: sema.diagnostics_display_range(d).range,
-                severity: Severity::Error,
-                fix: None,
-            })
+            res.borrow_mut()
+                .push(Diagnostic::error(sema.diagnostics_display_range(d).range, d.message()));
         });
 
     if let Some(m) = sema.to_module_def(file_id) {
@@ -125,22 +149,11 @@ pub(crate) fn diagnostics(
 }
 
 fn diagnostic_with_fix<D: DiagnosticWithFix>(d: &D, sema: &Semantics<RootDatabase>) -> Diagnostic {
-    Diagnostic {
-        // name: Some(d.name().into()),
-        range: sema.diagnostics_display_range(d).range,
-        message: d.message(),
-        severity: Severity::Error,
-        fix: d.fix(&sema),
-    }
+    Diagnostic::error(sema.diagnostics_display_range(d).range, d.message()).with_fix(d.fix(&sema))
 }
 
 fn warning_with_fix<D: DiagnosticWithFix>(d: &D, sema: &Semantics<RootDatabase>) -> Diagnostic {
-    Diagnostic {
-        range: sema.diagnostics_display_range(d).range,
-        message: d.message(),
-        severity: Severity::WeakWarning,
-        fix: d.fix(&sema),
-    }
+    Diagnostic::hint(sema.diagnostics_display_range(d).range, d.message()).with_fix(d.fix(&sema))
 }
 
 fn check_unnecessary_braces_in_use_statement(
@@ -161,17 +174,14 @@ fn check_unnecessary_braces_in_use_statement(
                     edit_builder.finish()
                 });
 
-        acc.push(Diagnostic {
-            // name: None,
-            range: use_range,
-            message: "Unnecessary braces in use statement".to_string(),
-            severity: Severity::WeakWarning,
-            fix: Some(Fix::new(
-                "Remove unnecessary braces",
-                SourceFileEdit { file_id, edit }.into(),
-                use_range,
-            )),
-        });
+        acc.push(
+            Diagnostic::hint(use_range, "Unnecessary braces in use statement".to_string())
+                .with_fix(Some(Fix::new(
+                    "Remove unnecessary braces",
+                    SourceFileEdit { file_id, edit }.into(),
+                    use_range,
+                ))),
+        );
     }
 
     Some(())
@@ -578,6 +588,7 @@ fn test_fn() {
                                 fix_trigger_range: 0..8,
                             },
                         ),
+                        unused: false,
                     },
                 ]
             "#]],
diff --git a/crates/ide/src/diagnostics/field_shorthand.rs b/crates/ide/src/diagnostics/field_shorthand.rs
index 2c4acd783..54e9fce9e 100644
--- a/crates/ide/src/diagnostics/field_shorthand.rs
+++ b/crates/ide/src/diagnostics/field_shorthand.rs
@@ -6,7 +6,7 @@ use ide_db::source_change::SourceFileEdit;
 use syntax::{ast, match_ast, AstNode, SyntaxNode};
 use text_edit::TextEdit;
 
-use crate::{Diagnostic, Fix, Severity};
+use crate::{Diagnostic, Fix};
 
 pub(super) fn check(acc: &mut Vec<Diagnostic>, file_id: FileId, node: &SyntaxNode) {
     match_ast! {
@@ -46,17 +46,15 @@ fn check_expr_field_shorthand(
         let edit = edit_builder.finish();
 
         let field_range = record_field.syntax().text_range();
-        acc.push(Diagnostic {
-            // name: None,
-            range: field_range,
-            message: "Shorthand struct initialization".to_string(),
-            severity: Severity::WeakWarning,
-            fix: Some(Fix::new(
-                "Use struct shorthand initialization",
-                SourceFileEdit { file_id, edit }.into(),
-                field_range,
-            )),
-        });
+        acc.push(
+            Diagnostic::hint(field_range, "Shorthand struct initialization".to_string()).with_fix(
+                Some(Fix::new(
+                    "Use struct shorthand initialization",
+                    SourceFileEdit { file_id, edit }.into(),
+                    field_range,
+                )),
+            ),
+        );
     }
 }
 
@@ -88,17 +86,13 @@ fn check_pat_field_shorthand(
         let edit = edit_builder.finish();
 
         let field_range = record_pat_field.syntax().text_range();
-        acc.push(Diagnostic {
-            // name: None,
-            range: field_range,
-            message: "Shorthand struct pattern".to_string(),
-            severity: Severity::WeakWarning,
-            fix: Some(Fix::new(
+        acc.push(Diagnostic::hint(field_range, "Shorthand struct pattern".to_string()).with_fix(
+            Some(Fix::new(
                 "Use struct field shorthand",
                 SourceFileEdit { file_id, edit }.into(),
                 field_range,
             )),
-        });
+        ));
     }
 }
 
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index d9dc63b33..b9d8b8a2b 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -130,7 +130,7 @@ fn get_doc_link(db: &RootDatabase, definition: Definition) -> Option<String> {
     let module = definition.module(db)?;
     let krate = module.krate();
     let import_map = db.import_map(krate.into());
-    let base = once(krate.declaration_name(db)?.to_string())
+    let base = once(krate.display_name(db)?.to_string())
         .chain(import_map.path_of(ns)?.segments.iter().map(|name| name.to_string()))
         .join("/");
 
@@ -188,7 +188,7 @@ fn rewrite_intra_doc_link(
     let krate = resolved.module(db)?.krate();
     let canonical_path = resolved.canonical_path(db)?;
     let new_target = get_doc_url(db, &krate)?
-        .join(&format!("{}/", krate.declaration_name(db)?))
+        .join(&format!("{}/", krate.display_name(db)?))
         .ok()?
         .join(&canonical_path.replace("::", "/"))
         .ok()?
@@ -208,7 +208,7 @@ fn rewrite_url_link(db: &RootDatabase, def: ModuleDef, target: &str) -> Option<S
     let module = def.module(db)?;
     let krate = module.krate();
     let canonical_path = def.canonical_path(db)?;
-    let base = format!("{}/{}", krate.declaration_name(db)?, canonical_path.replace("::", "/"));
+    let base = format!("{}/{}", krate.display_name(db)?, canonical_path.replace("::", "/"));
 
     get_doc_url(db, &krate)
         .and_then(|url| url.join(&base).ok())
@@ -357,7 +357,7 @@ fn get_doc_url(db: &RootDatabase, krate: &Crate) -> Option<Url> {
             //
             // FIXME: clicking on the link should just open the file in the editor,
             // instead of falling back to external urls.
-            Some(format!("https://docs.rs/{}/*/", krate.declaration_name(db)?))
+            Some(format!("https://docs.rs/{}/*/", krate.display_name(db)?))
         })
         .and_then(|s| Url::parse(&s).ok())
 }
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 845333e2a..6466422c5 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -300,7 +300,7 @@ fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String>
 
 fn render_path(db: &RootDatabase, module: Module, item_name: Option<String>) -> String {
     let crate_name =
-        db.crate_graph()[module.krate().into()].declaration_name.as_ref().map(ToString::to_string);
+        db.crate_graph()[module.krate().into()].display_name.as_ref().map(|it| it.to_string());
     let module_path = module
         .path_to_root(db)
         .into_iter()
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
index e2079bbcf..cccea129a 100644
--- a/crates/ide/src/inlay_hints.rs
+++ b/crates/ide/src/inlay_hints.rs
@@ -1,15 +1,14 @@
 use assists::utils::FamousDefs;
+use either::Either;
 use hir::{known, HirDisplay, Semantics};
 use ide_db::RootDatabase;
 use stdx::to_lower_snake_case;
 use syntax::{
-    ast::{self, ArgListOwner, AstNode},
+    ast::{self, ArgListOwner, AstNode, NameOwner},
     match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange, T,
 };
 
 use crate::FileId;
-use ast::NameOwner;
-use either::Either;
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct InlayHintsConfig {
@@ -100,6 +99,9 @@ fn get_chaining_hints(
         return None;
     }
 
+    let krate = sema.scope(expr.syntax()).module().map(|it| it.krate());
+    let famous_defs = FamousDefs(&sema, krate);
+
     let mut tokens = expr
         .syntax()
         .siblings_with_tokens(Direction::Next)
@@ -129,7 +131,7 @@ fn get_chaining_hints(
         acc.push(InlayHint {
             range: expr.syntax().text_range(),
             kind: InlayKind::ChainingHint,
-            label: hint_iterator(sema, config, &ty).unwrap_or_else(|| {
+            label: hint_iterator(sema, &famous_defs, config, &ty).unwrap_or_else(|| {
                 ty.display_truncated(sema.db, config.max_length).to_string().into()
             }),
         });
@@ -189,6 +191,9 @@ fn get_bind_pat_hints(
         return None;
     }
 
+    let krate = sema.scope(pat.syntax()).module().map(|it| it.krate());
+    let famous_defs = FamousDefs(&sema, krate);
+
     let ty = sema.type_of_pat(&pat.clone().into())?;
 
     if should_not_display_type_hint(sema, &pat, &ty) {
@@ -197,7 +202,7 @@ fn get_bind_pat_hints(
     acc.push(InlayHint {
         range: pat.syntax().text_range(),
         kind: InlayKind::TypeHint,
-        label: hint_iterator(sema, config, &ty)
+        label: hint_iterator(sema, &famous_defs, config, &ty)
             .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string().into()),
     });
 
@@ -207,6 +212,7 @@ fn get_bind_pat_hints(
 /// Checks if the type is an Iterator from std::iter and replaces its hint with an `impl Iterator<Item = Ty>`.
 fn hint_iterator(
     sema: &Semantics<RootDatabase>,
+    famous_defs: &FamousDefs,
     config: &InlayHintsConfig,
     ty: &hir::Type,
 ) -> Option<SmolStr> {
@@ -215,11 +221,11 @@ fn hint_iterator(
         .last()
         .and_then(|strukt| strukt.as_adt())?;
     let krate = strukt.krate(db)?;
-    if krate.declaration_name(db).as_deref() != Some("core") {
+    if krate != famous_defs.core()? {
         return None;
     }
-    let iter_trait = FamousDefs(sema, krate).core_iter_Iterator()?;
-    let iter_mod = FamousDefs(sema, krate).core_iter()?;
+    let iter_trait = famous_defs.core_iter_Iterator()?;
+    let iter_mod = famous_defs.core_iter()?;
     // assert this struct comes from `core::iter`
     iter_mod.visibility_of(db, &strukt.into()).filter(|&vis| vis == hir::Visibility::Public)?;
     if ty.impls_trait(db, iter_trait, &[]) {
@@ -231,7 +237,7 @@ fn hint_iterator(
             const LABEL_START: &str = "impl Iterator<Item = ";
             const LABEL_END: &str = ">";
 
-            let ty_display = hint_iterator(sema, config, &ty)
+            let ty_display = hint_iterator(sema, famous_defs, config, &ty)
                 .map(|assoc_type_impl| assoc_type_impl.to_string())
                 .unwrap_or_else(|| {
                     ty.display_truncated(
diff --git a/crates/ide/src/prime_caches.rs b/crates/ide/src/prime_caches.rs
index 9687c2734..6944dbcd2 100644
--- a/crates/ide/src/prime_caches.rs
+++ b/crates/ide/src/prime_caches.rs
@@ -32,8 +32,7 @@ pub(crate) fn prime_caches(db: &RootDatabase, cb: &(dyn Fn(PrimeCachesProgress)
     // Unfortunately rayon prevents panics from propagation out of a `scope`, which breaks
     // cancellation, so we cannot use rayon.
     for (i, krate) in topo.iter().enumerate() {
-        let crate_name =
-            graph[*krate].declaration_name.as_ref().map(ToString::to_string).unwrap_or_default();
+        let crate_name = graph[*krate].display_name.as_deref().unwrap_or_default().to_string();
 
         cb(PrimeCachesProgress::StartedOnCrate {
             on_crate: crate_name,
diff --git a/crates/ide/src/status.rs b/crates/ide/src/status.rs
index f67f10491..0af84daa0 100644
--- a/crates/ide/src/status.rs
+++ b/crates/ide/src/status.rs
@@ -45,7 +45,7 @@ pub(crate) fn status(db: &RootDatabase, file_id: Option<FileId>) -> String {
         match krate {
             Some(krate) => {
                 let crate_graph = db.crate_graph();
-                let display_crate = |krate: CrateId| match &crate_graph[krate].declaration_name {
+                let display_crate = |krate: CrateId| match &crate_graph[krate].display_name {
                     Some(it) => format!("{}({:?})", it, krate),
                     None => format!("{:?}", krate),
                 };