Implement location link for type inlay hints

crates/hir-ty/src/display.rs

@@ -16,7 +16,7 @@ use hir_def::{
     path::{Path, PathKind},
     type_ref::{ConstScalar, TraitBoundModifier, TypeBound, TypeRef},
     visibility::Visibility,
-    HasModule, ItemContainerId, Lookup, ModuleId, TraitId,
+    HasModule, ItemContainerId, Lookup, ModuleDefId, ModuleId, TraitId,
 };
 use hir_expand::{hygiene::Hygiene, name::Name};
 use itertools::Itertools;
@@ -35,9 +35,27 @@ use crate::{
     TraitRefExt, Ty, TyExt, TyKind, WhereClause,
 };
 
+pub trait HirWrite: fmt::Write {
+    fn start_location_link(&mut self, location: ModuleDefId);
+    fn end_location_link(&mut self);
+}
+
+// String will ignore link metadata
+impl HirWrite for String {
+    fn start_location_link(&mut self, _: ModuleDefId) {}
+
+    fn end_location_link(&mut self) {}
+}
+
+// `core::Formatter` will ignore metadata
+impl HirWrite for fmt::Formatter<'_> {
+    fn start_location_link(&mut self, _: ModuleDefId) {}
+    fn end_location_link(&mut self) {}
+}
+
 pub struct HirFormatter<'a> {
     pub db: &'a dyn HirDatabase,
-    fmt: &'a mut dyn fmt::Write,
+    fmt: &'a mut dyn HirWrite,
     buf: String,
     curr_size: usize,
     pub(crate) max_size: Option<usize>,
@@ -45,6 +63,16 @@ pub struct HirFormatter<'a> {
     display_target: DisplayTarget,
 }
 
+impl HirFormatter<'_> {
+    fn start_location_link(&mut self, location: ModuleDefId) {
+        self.fmt.start_location_link(location);
+    }
+
+    fn end_location_link(&mut self) {
+        self.fmt.end_location_link();
+    }
+}
+
 pub trait HirDisplay {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError>;
 
@@ -245,12 +273,9 @@ pub struct HirDisplayWrapper<'a, T> {
     display_target: DisplayTarget,
 }
 
-impl<'a, T> fmt::Display for HirDisplayWrapper<'a, T>
+impl<T: HirDisplay> HirDisplayWrapper<'_, T> {
-where
+    pub fn write_to<F: HirWrite>(&self, f: &mut F) -> Result<(), HirDisplayError> {
-    T: HirDisplay,
+        self.t.hir_fmt(&mut HirFormatter {
-{
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.t.hir_fmt(&mut HirFormatter {
             db: self.db,
             fmt: f,
             buf: String::with_capacity(20),
@@ -258,7 +283,16 @@ where
             max_size: self.max_size,
             omit_verbose_types: self.omit_verbose_types,
             display_target: self.display_target,
-        }) {
+        })
+    }
+}
+
+impl<'a, T> fmt::Display for HirDisplayWrapper<'a, T>
+where
+    T: HirDisplay,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.write_to(f) {
             Ok(()) => Ok(()),
             Err(HirDisplayError::FmtError) => Err(fmt::Error),
             Err(HirDisplayError::DisplaySourceCodeError(_)) => {
@@ -530,6 +564,7 @@ impl HirDisplay for Ty {
                 }
             }
             TyKind::Adt(AdtId(def_id), parameters) => {
+                f.start_location_link((*def_id).into());
                 match f.display_target {
                     DisplayTarget::Diagnostics | DisplayTarget::Test => {
                         let name = match *def_id {
@@ -554,6 +589,7 @@ impl HirDisplay for Ty {
                         }
                     }
                 }
+                f.end_location_link();
 
                 if parameters.len(Interner) > 0 {
                     let parameters_to_write = if f.display_target.is_source_code()

crates/hir/src/lib.rs

@@ -114,12 +114,20 @@ pub use {
         path::{ModPath, PathKind},
         type_ref::{Mutability, TypeRef},
         visibility::Visibility,
+        // FIXME: This is here since it is input of a method in `HirWrite`
+        // and things outside of hir need to implement that trait. We probably
+        // should move whole `hir_ty::display` to this crate so we will become
+        // able to use `ModuleDef` or `Definition` instead of `ModuleDefId`.
+        ModuleDefId,
     },
     hir_expand::{
         name::{known, Name},
         ExpandResult, HirFileId, InFile, MacroFile, Origin,
     },
-    hir_ty::{display::HirDisplay, PointerCast, Safety},
+    hir_ty::{
+        display::{HirDisplay, HirWrite},
+        PointerCast, Safety,
+    },
 };
 
 // These are negative re-exports: pub using these names is forbidden, they

crates/ide/src/inlay_hints.rs

@@ -1,15 +1,19 @@
-use std::fmt;
+use std::{
+    fmt::{self, Write},
+    mem::take,
+};
 
 use either::Either;
-use hir::{known, HasVisibility, HirDisplay, Semantics};
+use hir::{known, HasVisibility, HirDisplay, HirWrite, ModuleDef, ModuleDefId, Semantics};
 use ide_db::{base_db::FileRange, famous_defs::FamousDefs, RootDatabase};
 use itertools::Itertools;
+use stdx::never;
 use syntax::{
     ast::{self, AstNode},
     match_ast, NodeOrToken, SyntaxNode, TextRange, TextSize,
 };
 
-use crate::FileId;
+use crate::{navigation_target::TryToNav, FileId};
 
 mod closing_brace;
 mod implicit_static;
@@ -89,6 +93,7 @@ pub enum InlayTooltip {
     HoverOffset(FileId, TextSize),
 }
 
+#[derive(Default)]
 pub struct InlayHintLabel {
     pub parts: Vec<InlayHintLabelPart>,
 }
@@ -172,6 +177,96 @@ impl fmt::Debug for InlayHintLabelPart {
     }
 }
 
+#[derive(Debug)]
+struct InlayHintLabelBuilder<'a> {
+    db: &'a RootDatabase,
+    result: InlayHintLabel,
+    last_part: String,
+    location: Option<FileRange>,
+}
+
+impl fmt::Write for InlayHintLabelBuilder<'_> {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.last_part.write_str(s)
+    }
+}
+
+impl HirWrite for InlayHintLabelBuilder<'_> {
+    fn start_location_link(&mut self, def: ModuleDefId) {
+        if self.location.is_some() {
+            never!("location link is already started");
+        }
+        self.make_new_part();
+        let Some(location) = ModuleDef::from(def).try_to_nav(self.db) else { return };
+        let location =
+            FileRange { file_id: location.file_id, range: location.focus_or_full_range() };
+        self.location = Some(location);
+    }
+
+    fn end_location_link(&mut self) {
+        self.make_new_part();
+    }
+}
+
+impl InlayHintLabelBuilder<'_> {
+    fn make_new_part(&mut self) {
+        self.result.parts.push(InlayHintLabelPart {
+            text: take(&mut self.last_part),
+            linked_location: self.location.take(),
+        });
+    }
+
+    fn finish(mut self) -> InlayHintLabel {
+        self.make_new_part();
+        self.result
+    }
+}
+
+fn label_of_ty(
+    sema: &Semantics<'_, RootDatabase>,
+    desc_pat: &impl AstNode,
+    config: &InlayHintsConfig,
+    ty: hir::Type,
+) -> Option<InlayHintLabel> {
+    fn rec(
+        sema: &Semantics<'_, RootDatabase>,
+        famous_defs: &FamousDefs<'_, '_>,
+        mut max_length: Option<usize>,
+        ty: hir::Type,
+        label_builder: &mut InlayHintLabelBuilder<'_>,
+    ) {
+        let iter_item_type = hint_iterator(sema, &famous_defs, &ty);
+        match iter_item_type {
+            Some(ty) => {
+                const LABEL_START: &str = "impl Iterator<Item = ";
+                const LABEL_END: &str = ">";
+
+                max_length =
+                    max_length.map(|len| len.saturating_sub(LABEL_START.len() + LABEL_END.len()));
+
+                label_builder.write_str(LABEL_START).unwrap();
+                rec(sema, famous_defs, max_length, ty, label_builder);
+                label_builder.write_str(LABEL_END).unwrap();
+            }
+            None => {
+                let _ = ty.display_truncated(sema.db, max_length).write_to(label_builder);
+            }
+        };
+    }
+
+    let krate = sema.scope(desc_pat.syntax())?.krate();
+    let famous_defs = FamousDefs(sema, krate);
+    let mut label_builder = InlayHintLabelBuilder {
+        db: sema.db,
+        last_part: String::new(),
+        location: None,
+        result: InlayHintLabel::default(),
+    };
+    rec(sema, &famous_defs, config.max_length, ty, &mut label_builder);
+    let r = label_builder.finish();
+    Some(r)
+}
+
 // Feature: Inlay Hints
 //
 // rust-analyzer shows additional information inline with the source code.
@@ -224,7 +319,7 @@ pub(crate) fn inlay_hints(
 
 fn hints(
     hints: &mut Vec<InlayHint>,
-    famous_defs @ FamousDefs(sema, _): &FamousDefs<'_, '_>,
+    FamousDefs(sema, _): &FamousDefs<'_, '_>,
     config: &InlayHintsConfig,
     file_id: FileId,
     node: SyntaxNode,
@@ -233,14 +328,14 @@ fn hints(
     match_ast! {
         match node {
             ast::Expr(expr) => {
-                chaining::hints(hints, sema, &famous_defs, config, file_id, &expr);
+                chaining::hints(hints, sema, config, file_id, &expr);
                 adjustment::hints(hints, sema, config, &expr);
                 match expr {
                     ast::Expr::CallExpr(it) => param_name::hints(hints, sema, config, ast::Expr::from(it)),
                     ast::Expr::MethodCallExpr(it) => {
                         param_name::hints(hints, sema, config, ast::Expr::from(it))
                     }
-                    ast::Expr::ClosureExpr(it) => closure_ret::hints(hints, sema, &famous_defs, config, file_id, it),
+                    ast::Expr::ClosureExpr(it) => closure_ret::hints(hints, sema, config, file_id, it),
                     // We could show reborrows for all expressions, but usually that is just noise to the user
                     // and the main point here is to show why "moving" a mutable reference doesn't necessarily move it
                     // ast::Expr::PathExpr(_) => reborrow_hints(hints, sema, config, &expr),
@@ -270,13 +365,12 @@ fn hints(
     };
 }
 
-/// Checks if the type is an Iterator from std::iter and replaces its hint with an `impl Iterator<Item = Ty>`.
+/// Checks if the type is an Iterator from std::iter and returns its item type.
 fn hint_iterator(
     sema: &Semantics<'_, RootDatabase>,
     famous_defs: &FamousDefs<'_, '_>,
-    config: &InlayHintsConfig,
     ty: &hir::Type,
-) -> Option<String> {
+) -> Option<hir::Type> {
     let db = sema.db;
     let strukt = ty.strip_references().as_adt()?;
     let krate = strukt.module(db).krate();
@@ -299,21 +393,7 @@ fn hint_iterator(
             _ => None,
         })?;
         if let Some(ty) = ty.normalize_trait_assoc_type(db, &[], assoc_type_item) {
-            const LABEL_START: &str = "impl Iterator<Item = ";
+            return Some(ty);
-            const LABEL_END: &str = ">";
-
-            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(
-                        db,
-                        config
-                            .max_length
-                            .map(|len| len.saturating_sub(LABEL_START.len() + LABEL_END.len())),
-                    )
-                    .to_string()
-                });
-            return Some(format!("{}{}{}", LABEL_START, ty_display, LABEL_END));
         }
     }
 

crates/ide/src/inlay_hints/bind_pat.rs

@@ -3,8 +3,8 @@
 //! fn f(a: i32, b: i32) -> i32 { a + b }
 //! let _x /* i32 */= f(4, 4);
 //! ```
-use hir::{HirDisplay, Semantics, TypeInfo};
+use hir::{Semantics, TypeInfo};
-use ide_db::{base_db::FileId, famous_defs::FamousDefs, RootDatabase};
+use ide_db::{base_db::FileId, RootDatabase};
 
 use itertools::Itertools;
 use syntax::{
@@ -13,10 +13,11 @@ use syntax::{
 };
 
 use crate::{
-    inlay_hints::{closure_has_block_body, hint_iterator},
+    inlay_hints::closure_has_block_body, InlayHint, InlayHintsConfig, InlayKind, InlayTooltip,
-    InlayHint, InlayHintsConfig, InlayKind, InlayTooltip,
 };
 
+use super::label_of_ty;
+
 pub(super) fn hints(
     acc: &mut Vec<InlayHint>,
     sema: &Semantics<'_, RootDatabase>,
@@ -36,22 +37,13 @@ pub(super) fn hints(
         return None;
     }
 
-    let krate = sema.scope(desc_pat.syntax())?.krate();
+    let label = label_of_ty(sema, desc_pat, config, ty)?;
-    let famous_defs = FamousDefs(sema, krate);
-    let label = hint_iterator(sema, &famous_defs, config, &ty);
 
-    let label = match label {
+    if config.hide_named_constructor_hints
-        Some(label) => label,
+        && is_named_constructor(sema, pat, &label.to_string()).is_some()
-        None => {
+    {
-            let ty_name = ty.display_truncated(sema.db, config.max_length).to_string();
+        return None;
-            if config.hide_named_constructor_hints
+    }
-                && is_named_constructor(sema, pat, &ty_name).is_some()
-            {
-                return None;
-            }
-            ty_name
-        }
-    };
 
     acc.push(InlayHint {
         range: match pat.name() {
@@ -59,7 +51,7 @@ pub(super) fn hints(
             None => pat.syntax().text_range(),
         },
         kind: InlayKind::TypeHint,
-        label: label.into(),
+        label,
         tooltip: pat
             .name()
             .map(|it| it.syntax().text_range())
@@ -346,7 +338,31 @@ fn main(a: SliceIter<'_, Container>) {
                         range: 484..485,
                         kind: ChainingHint,
                         label: [
-                            "SliceIter<Container>",
+                            "",
+                            InlayHintLabelPart {
+                                text: "SliceIter",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 289..298,
+                                    },
+                                ),
+                            },
+                            "<",
+                            InlayHintLabelPart {
+                                text: "Container",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 238..247,
+                                    },
+                                ),
+                            },
+                            ">",
                         ],
                         tooltip: Some(
                             HoverRanged(

crates/ide/src/inlay_hints/chaining.rs

@@ -1,19 +1,18 @@
 //! Implementation of "chaining" inlay hints.
-use hir::{HirDisplay, Semantics};
+use hir::Semantics;
-use ide_db::{famous_defs::FamousDefs, RootDatabase};
+use ide_db::RootDatabase;
 use syntax::{
     ast::{self, AstNode},
     Direction, NodeOrToken, SyntaxKind, T,
 };
 
-use crate::{
+use crate::{FileId, InlayHint, InlayHintsConfig, InlayKind, InlayTooltip};
-    inlay_hints::hint_iterator, FileId, InlayHint, InlayHintsConfig, InlayKind, InlayTooltip,
+
-};
+use super::label_of_ty;
 
 pub(super) fn hints(
     acc: &mut Vec<InlayHint>,
     sema: &Semantics<'_, RootDatabase>,
-    famous_defs: &FamousDefs<'_, '_>,
     config: &InlayHintsConfig,
     file_id: FileId,
     expr: &ast::Expr,
@@ -62,9 +61,7 @@ pub(super) fn hints(
             acc.push(InlayHint {
                 range: expr.syntax().text_range(),
                 kind: InlayKind::ChainingHint,
-                label: hint_iterator(sema, &famous_defs, config, &ty)
+                label: label_of_ty(sema, desc_expr, config, ty)?,
-                    .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string())
-                    .into(),
                 tooltip: Some(InlayTooltip::HoverRanged(file_id, expr.syntax().text_range())),
             });
         }
@@ -110,7 +107,19 @@ fn main() {
                         range: 147..172,
                         kind: ChainingHint,
                         label: [
-                            "B",
+                            "",
+                            InlayHintLabelPart {
+                                text: "B",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 63..64,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -125,7 +134,19 @@ fn main() {
                         range: 147..154,
                         kind: ChainingHint,
                         label: [
-                            "A",
+                            "",
+                            InlayHintLabelPart {
+                                text: "A",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 7..8,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -185,7 +206,19 @@ fn main() {
                         range: 143..190,
                         kind: ChainingHint,
                         label: [
-                            "C",
+                            "",
+                            InlayHintLabelPart {
+                                text: "C",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 51..52,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -200,7 +233,19 @@ fn main() {
                         range: 143..179,
                         kind: ChainingHint,
                         label: [
-                            "B",
+                            "",
+                            InlayHintLabelPart {
+                                text: "B",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 29..30,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -245,7 +290,31 @@ fn main() {
                         range: 246..283,
                         kind: ChainingHint,
                         label: [
-                            "B<X<i32, bool>>",
+                            "",
+                            InlayHintLabelPart {
+                                text: "B",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 23..24,
+                                    },
+                                ),
+                            },
+                            "<",
+                            InlayHintLabelPart {
+                                text: "X",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 55..56,
+                                    },
+                                ),
+                            },
+                            "<i32, bool>>",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -260,7 +329,31 @@ fn main() {
                         range: 246..265,
                         kind: ChainingHint,
                         label: [
-                            "A<X<i32, bool>>",
+                            "",
+                            InlayHintLabelPart {
+                                text: "A",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 7..8,
+                                    },
+                                ),
+                            },
+                            "<",
+                            InlayHintLabelPart {
+                                text: "X",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 55..56,
+                                    },
+                                ),
+                            },
+                            "<i32, bool>>",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -352,7 +445,19 @@ fn main() {
                         range: 174..189,
                         kind: ChainingHint,
                         label: [
-                            "&mut MyIter",
+                            "&mut ",
+                            InlayHintLabelPart {
+                                text: "MyIter",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 24..30,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -396,7 +501,19 @@ fn main() {
                         range: 124..130,
                         kind: TypeHint,
                         label: [
-                            "Struct",
+                            "",
+                            InlayHintLabelPart {
+                                text: "Struct",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 7..13,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -411,7 +528,19 @@ fn main() {
                         range: 145..185,
                         kind: ChainingHint,
                         label: [
-                            "Struct",
+                            "",
+                            InlayHintLabelPart {
+                                text: "Struct",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 7..13,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(
@@ -426,7 +555,19 @@ fn main() {
                         range: 145..168,
                         kind: ChainingHint,
                         label: [
-                            "Struct",
+                            "",
+                            InlayHintLabelPart {
+                                text: "Struct",
+                                linked_location: Some(
+                                    FileRange {
+                                        file_id: FileId(
+                                            0,
+                                        ),
+                                        range: 7..13,
+                                    },
+                                ),
+                            },
+                            "",
                         ],
                         tooltip: Some(
                             HoverRanged(

crates/ide/src/inlay_hints/closure_ret.rs

@@ -1,17 +1,18 @@
 //! Implementation of "closure return type" inlay hints.
-use hir::{HirDisplay, Semantics};
+use hir::Semantics;
-use ide_db::{base_db::FileId, famous_defs::FamousDefs, RootDatabase};
+use ide_db::{base_db::FileId, RootDatabase};
 use syntax::ast::{self, AstNode};
 
 use crate::{
-    inlay_hints::{closure_has_block_body, hint_iterator},
+    inlay_hints::closure_has_block_body, ClosureReturnTypeHints, InlayHint, InlayHintsConfig,
-    ClosureReturnTypeHints, InlayHint, InlayHintsConfig, InlayKind, InlayTooltip,
+    InlayKind, InlayTooltip,
 };
 
+use super::label_of_ty;
+
 pub(super) fn hints(
     acc: &mut Vec<InlayHint>,
     sema: &Semantics<'_, RootDatabase>,
-    famous_defs: &FamousDefs<'_, '_>,
     config: &InlayHintsConfig,
     file_id: FileId,
     closure: ast::ClosureExpr,
@@ -42,9 +43,7 @@ pub(super) fn hints(
     acc.push(InlayHint {
         range: param_list.syntax().text_range(),
         kind: InlayKind::ClosureReturnTypeHint,
-        label: hint_iterator(sema, &famous_defs, config, &ty)
+        label: label_of_ty(sema, &param_list, config, ty)?,
-            .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string())
-            .into(),
         tooltip: Some(InlayTooltip::HoverRanged(file_id, param_list.syntax().text_range())),
     });
     Some(())