Merge #11445

11445: Upstream inlay hints r=lnicola a=lnicola

Closes #2797
Closes #3394 (since now resolve the hints for the range given only, not for the whole document. We don't actually resolve anything due to [hard requirement](#11445 (comment)) on label being immutable. Any further heavy actions could go to the `resolve` method that's now available via the official Code API for hints)

Based on `@SomeoneToIgnore's` branch, with a couple of updates:

 - I squashed, more or less successfully, the commits on that branch
 - downloading the `.d.ts` no longer works, but you can get it manually from https://raw.githubusercontent.com/microsoft/vscode/release/1.64/src/vscode-dts/vscode.proposed.inlayHints.d.ts
 - you might need to pass `--enable-proposed-api matklad.rust-analyzer`
 - if I'm reading the definition right, `InlayHintKind` needs to be serialized as a number, not string
 - this doesn't work anyway -- the client-side gets the hints, but they don't display

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Co-authored-by: Laurențiu Nicola <lnicola@dend.ro>

crates/ide/src/inlay_hints.rs

@@ -5,7 +5,7 @@ use itertools::Itertools;
 use stdx::to_lower_snake_case;
 use syntax::{
     ast::{self, AstNode, HasArgList, HasName, UnaryOp},
-    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange, T,
+    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, SyntaxNode, TextRange, T,
 };
 
 use crate::FileId;
@@ -58,32 +58,58 @@ pub struct InlayHint {
 pub(crate) fn inlay_hints(
     db: &RootDatabase,
     file_id: FileId,
+    range_limit: Option<FileRange>,
     config: &InlayHintsConfig,
 ) -> Vec<InlayHint> {
     let _p = profile::span("inlay_hints");
     let sema = Semantics::new(db);
     let file = sema.parse(file_id);
     let file = file.syntax();
 
-    let mut res = Vec::new();
-
-    for node in file.descendants() {
-        if let Some(expr) = ast::Expr::cast(node.clone()) {
-            get_chaining_hints(&mut res, &sema, config, &expr);
-            match expr {
-                ast::Expr::CallExpr(it) => {
-                    get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it));
-                }
-                ast::Expr::MethodCallExpr(it) => {
-                    get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it));
+    let mut hints = Vec::new();
+
+    if let Some(range_limit) = range_limit {
+        let range_limit = range_limit.range;
+        match file.covering_element(range_limit) {
+            NodeOrToken::Token(_) => return hints,
+            NodeOrToken::Node(n) => {
+                for node in n
+                    .descendants()
+                    .filter(|descendant| range_limit.contains_range(descendant.text_range()))
+                {
+                    get_hints(&mut hints, &sema, config, node);
                 }
-                _ => (),
             }
-        } else if let Some(it) = ast::IdentPat::cast(node.clone()) {
-            get_bind_pat_hints(&mut res, &sema, config, &it);
         }
+    } else {
+        for node in file.descendants() {
+            get_hints(&mut hints, &sema, config, node);
+        }
+    }
+
+    hints
+}
+
+fn get_hints(
+    hints: &mut Vec<InlayHint>,
+    sema: &Semantics<RootDatabase>,
+    config: &InlayHintsConfig,
+    node: SyntaxNode,
+) {
+    if let Some(expr) = ast::Expr::cast(node.clone()) {
+        get_chaining_hints(hints, sema, config, &expr);
+        match expr {
+            ast::Expr::CallExpr(it) => {
+                get_param_name_hints(hints, sema, config, ast::Expr::from(it));
+            }
+            ast::Expr::MethodCallExpr(it) => {
+                get_param_name_hints(hints, sema, config, ast::Expr::from(it));
+            }
+            _ => (),
+        }
+    } else if let Some(it) = ast::IdentPat::cast(node) {
+        get_bind_pat_hints(hints, sema, config, &it);
     }
-    res
 }
 
 fn get_chaining_hints(
@@ -541,6 +567,8 @@ fn get_callable(
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
+    use ide_db::base_db::FileRange;
+    use syntax::{TextRange, TextSize};
     use test_utils::extract_annotations;
 
     use crate::{fixture, inlay_hints::InlayHintsConfig};
@@ -604,7 +632,7 @@ mod tests {
     fn check_with_config(config: InlayHintsConfig, ra_fixture: &str) {
         let (analysis, file_id) = fixture::file(ra_fixture);
         let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
-        let inlay_hints = analysis.inlay_hints(&config, file_id).unwrap();
+        let inlay_hints = analysis.inlay_hints(&config, file_id, None).unwrap();
         let actual =
             inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
         assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
@@ -613,7 +641,7 @@ mod tests {
     #[track_caller]
     fn check_expect(config: InlayHintsConfig, ra_fixture: &str, expect: Expect) {
         let (analysis, file_id) = fixture::file(ra_fixture);
-        let inlay_hints = analysis.inlay_hints(&config, file_id).unwrap();
+        let inlay_hints = analysis.inlay_hints(&config, file_id, None).unwrap();
         expect.assert_debug_eq(&inlay_hints)
     }
 
@@ -1045,6 +1073,55 @@ fn main() {
         )
     }
 
+    #[test]
+    fn check_hint_range_limit() {
+        let fixture = r#"
+        //- minicore: fn, sized
+        fn foo() -> impl Fn() { loop {} }
+        fn foo1() -> impl Fn(f64) { loop {} }
+        fn foo2() -> impl Fn(f64, f64) { loop {} }
+        fn foo3() -> impl Fn(f64, f64) -> u32 { loop {} }
+        fn foo4() -> &'static dyn Fn(f64, f64) -> u32 { loop {} }
+        fn foo5() -> &'static dyn Fn(&'static dyn Fn(f64, f64) -> u32, f64) -> u32 { loop {} }
+        fn foo6() -> impl Fn(f64, f64) -> u32 + Sized { loop {} }
+        fn foo7() -> *const (impl Fn(f64, f64) -> u32 + Sized) { loop {} }
+
+        fn main() {
+            let foo = foo();
+            let foo = foo1();
+            let foo = foo2();
+            let foo = foo3();
+             // ^^^ impl Fn(f64, f64) -> u32
+            let foo = foo4();
+             // ^^^ &dyn Fn(f64, f64) -> u32
+            let foo = foo5();
+            let foo = foo6();
+            let foo = foo7();
+        }
+        "#;
+        let (analysis, file_id) = fixture::file(fixture);
+        let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
+        let inlay_hints = analysis
+            .inlay_hints(
+                &InlayHintsConfig {
+                    parameter_hints: false,
+                    type_hints: true,
+                    chaining_hints: false,
+                    hide_named_constructor_hints: false,
+                    max_length: None,
+                },
+                file_id,
+                Some(FileRange {
+                    file_id,
+                    range: TextRange::new(TextSize::from(500), TextSize::from(600)),
+                }),
+            )
+            .unwrap();
+        let actual =
+            inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
+        assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
+    }
+
     #[test]
     fn fn_hints_ptr_rpit_fn_parentheses() {
         check_types(

crates/ide/src/lib.rs

@@ -358,8 +358,9 @@ impl Analysis {
         &self,
         config: &InlayHintsConfig,
         file_id: FileId,
+        range: Option<FileRange>,
     ) -> Cancellable<Vec<InlayHint>> {
-        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, config))
+        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, range, config))
     }
 
     /// Returns the set of folding ranges.

crates/ide/src/static_index.rs

@@ -112,6 +112,7 @@ impl StaticIndex<'_> {
                     max_length: Some(25),
                 },
                 file_id,
+                None,
             )
             .unwrap();
         // hovers

crates/rust-analyzer/src/caps.rs

@@ -115,6 +115,7 @@ pub fn server_capabilities(config: &Config) -> ServerCapabilities {
         experimental: Some(json!({
             "externalDocs": true,
             "hoverRange": true,
+            "inlayHints": true,
             "joinLines": true,
             "matchingBrace": true,
             "moveItem": true,

crates/rust-analyzer/src/handlers.rs

@@ -1318,11 +1318,22 @@ pub(crate) fn handle_inlay_hints(
     params: InlayHintsParams,
 ) -> Result<Vec<InlayHint>> {
     let _p = profile::span("handle_inlay_hints");
-    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let document_uri = &params.text_document.uri;
+    let file_id = from_proto::file_id(&snap, document_uri)?;
     let line_index = snap.file_line_index(file_id)?;
+    let range = params
+        .range
+        .map(|range| {
+            from_proto::file_range(
+                &snap,
+                TextDocumentIdentifier::new(document_uri.to_owned()),
+                range,
+            )
+        })
+        .transpose()?;
     Ok(snap
         .analysis
-        .inlay_hints(&snap.config.inlay_hints(), file_id)?
+        .inlay_hints(&snap.config.inlay_hints(), file_id, range)?
         .into_iter()
         .map(|it| to_proto::inlay_hint(&line_index, it))
         .collect())

crates/rust-analyzer/src/lsp_ext.rs

@@ -233,27 +233,34 @@ pub enum InlayHints {}
 impl Request for InlayHints {
     type Params = InlayHintsParams;
     type Result = Vec<InlayHint>;
-    const METHOD: &'static str = "rust-analyzer/inlayHints";
+    const METHOD: &'static str = "experimental/inlayHints";
 }
 
 #[derive(Serialize, Deserialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct InlayHintsParams {
     pub text_document: TextDocumentIdentifier,
+    pub range: Option<lsp_types::Range>,
 }
 
-#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
-pub enum InlayKind {
-    TypeHint,
-    ParameterHint,
-    ChainingHint,
+#[derive(Eq, PartialEq, Debug, Copy, Clone, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct InlayHintKind(u8);
+
+impl InlayHintKind {
+    pub const TYPE: InlayHintKind = InlayHintKind(1);
+    pub const PARAMETER: InlayHintKind = InlayHintKind(2);
 }
 
 #[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
 pub struct InlayHint {
-    pub range: Range,
-    pub kind: InlayKind,
     pub label: String,
+    pub position: Position,
+    pub kind: Option<InlayHintKind>,
+    pub tooltip: Option<String>,
+    pub padding_left: Option<bool>,
+    pub padding_right: Option<bool>,
 }
 
 pub enum Ssr {}

crates/rust-analyzer/src/to_proto.rs

@@ -416,12 +416,18 @@ pub(crate) fn signature_help(
 pub(crate) fn inlay_hint(line_index: &LineIndex, inlay_hint: InlayHint) -> lsp_ext::InlayHint {
     lsp_ext::InlayHint {
         label: inlay_hint.label.to_string(),
-        range: range(line_index, inlay_hint.range),
+        position: match inlay_hint.kind {
+            InlayKind::ParameterHint => position(line_index, inlay_hint.range.start()),
+            _ => position(line_index, inlay_hint.range.end()),
+        },
         kind: match inlay_hint.kind {
-            InlayKind::ParameterHint => lsp_ext::InlayKind::ParameterHint,
-            InlayKind::TypeHint => lsp_ext::InlayKind::TypeHint,
-            InlayKind::ChainingHint => lsp_ext::InlayKind::ChainingHint,
+            InlayKind::ParameterHint => Some(lsp_ext::InlayHintKind::PARAMETER),
+            InlayKind::TypeHint => Some(lsp_ext::InlayHintKind::TYPE),
+            InlayKind::ChainingHint => None,
         },
+        tooltip: None,
+        padding_left: Some(true),
+        padding_right: Some(true),
     }
 }
 

docs/dev/lsp-extensions.md

@@ -1,5 +1,5 @@
 <!---
-lsp_ext.rs hash: 5b53b92c9f9d6650
+lsp_ext.rs hash: e32fdde032ff6ebc
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue:
@@ -562,11 +562,11 @@ Expands macro call at a given position.
 
 ## Inlay Hints
 
-**Method:** `rust-analyzer/inlayHints`
+**Method:** `experimental/inlayHints`
 
 This request is sent from client to server to render "inlay hints" -- virtual text inserted into editor to show things like inferred types.
 Generally, the client should re-query inlay hints after every modification.
-Note that we plan to move this request to `experimental/inlayHints`, as it is not really Rust-specific, but the current API is not necessary the right one.
+Until it gets upstreamed, this follows the VS Code API.
 Upstream issues: https://github.com/microsoft/language-server-protocol/issues/956 , https://github.com/rust-analyzer/rust-analyzer/issues/2797
 
 **Request:**
@@ -581,9 +581,12 @@ interface InlayHintsParams {
 
 ```typescript
 interface InlayHint {
-    kind: "TypeHint" | "ParameterHint" | "ChainingHint",
-    range: Range,
-    label: string,
+    position: Position;
+    label: string | InlayHintLabelPart[];
+    tooltip?: string | MarkdownString | undefined;
+    kind?: InlayHintKind;
+    paddingLeft?: boolean;
+    paddingRight?: boolean;
 }
 ```
 

editors/code/.gitignore

@@ -3,3 +3,5 @@ node_modules
 server
 .vscode-test/
 *.vsix
+bundle
+vscode.proposed.d.ts