⬆️ rust-analyzer

Merge commit '368e0bb32f'

crates/ide/src/hover/render.rs

@@ -2,7 +2,9 @@
 use std::fmt::Display;
 
 use either::Either;
-use hir::{AsAssocItem, AttributeTemplate, HasAttrs, HasSource, HirDisplay, Semantics, TypeInfo};
+use hir::{
+    Adt, AsAssocItem, AttributeTemplate, HasAttrs, HasSource, HirDisplay, Semantics, TypeInfo,
+};
 use ide_db::{
     base_db::SourceDatabase,
     defs::Definition,
@@ -14,7 +16,9 @@ use ide_db::{
 use itertools::Itertools;
 use stdx::format_to;
 use syntax::{
-    algo, ast, match_ast, AstNode, Direction,
+    algo,
+    ast::{self, RecordPat},
+    match_ast, AstNode, Direction,
     SyntaxKind::{LET_EXPR, LET_STMT},
     SyntaxToken, T,
 };
@@ -250,6 +254,50 @@ pub(super) fn keyword(
     Some(HoverResult { markup, actions })
 }
 
+/// Returns missing types in a record pattern.
+/// Only makes sense when there's a rest pattern in the record pattern.
+/// i.e. `let S {a, ..} = S {a: 1, b: 2}`
+pub(super) fn struct_rest_pat(
+    sema: &Semantics<'_, RootDatabase>,
+    config: &HoverConfig,
+    pattern: &RecordPat,
+) -> HoverResult {
+    let missing_fields = sema.record_pattern_missing_fields(pattern);
+
+    // if there are no missing fields, the end result is a hover that shows ".."
+    // should be left in to indicate that there are no more fields in the pattern
+    // example, S {a: 1, b: 2, ..} when struct S {a: u32, b: u32}
+
+    let mut res = HoverResult::default();
+    let mut targets: Vec<hir::ModuleDef> = Vec::new();
+    let mut push_new_def = |item: hir::ModuleDef| {
+        if !targets.contains(&item) {
+            targets.push(item);
+        }
+    };
+    for (_, t) in &missing_fields {
+        walk_and_push_ty(sema.db, t, &mut push_new_def);
+    }
+
+    res.markup = {
+        let mut s = String::from(".., ");
+        for (f, _) in &missing_fields {
+            s += f.display(sema.db).to_string().as_ref();
+            s += ", ";
+        }
+        // get rid of trailing comma
+        s.truncate(s.len() - 2);
+
+        if config.markdown() {
+            Markup::fenced_block(&s)
+        } else {
+            s.into()
+        }
+    };
+    res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
+    res
+}
+
 pub(super) fn try_for_lint(attr: &ast::Attr, token: &SyntaxToken) -> Option<HoverResult> {
     let (path, tt) = attr.as_simple_call()?;
     if !tt.syntax().text_range().contains(token.text_range().start()) {
@@ -342,15 +390,35 @@ pub(super) fn definition(
     let mod_path = definition_mod_path(db, &def);
     let (label, docs) = match def {
         Definition::Macro(it) => label_and_docs(db, it),
-        Definition::Field(it) => label_and_docs(db, it),
+        Definition::Field(it) => label_and_layout_info_and_docs(db, it, |&it| {
+            let var_def = it.parent_def(db);
+            let id = it.index();
+            let layout = it.layout(db).ok()?;
+            let offset = match var_def {
+                hir::VariantDef::Struct(s) => Adt::from(s)
+                    .layout(db)
+                    .ok()
+                    .map(|layout| format!(", offset = {}", layout.fields.offset(id).bytes())),
+                _ => None,
+            };
+            Some(format!(
+                "size = {}, align = {}{}",
+                layout.size.bytes(),
+                layout.align.abi.bytes(),
+                offset.as_deref().unwrap_or_default()
+            ))
+        }),
         Definition::Module(it) => label_and_docs(db, it),
         Definition::Function(it) => label_and_docs(db, it),
-        Definition::Adt(it) => label_and_docs(db, it),
+        Definition::Adt(it) => label_and_layout_info_and_docs(db, it, |&it| {
+            let layout = it.layout(db).ok()?;
+            Some(format!("size = {}, align = {}", layout.size.bytes(), layout.align.abi.bytes()))
+        }),
         Definition::Variant(it) => label_value_and_docs(db, it, |&it| {
             if !it.parent_enum(db).is_data_carrying(db) {
                 match it.eval(db) {
-                    Ok(x) => Some(format!("{}", x)),
-                    Err(_) => it.value(db).map(|x| format!("{:?}", x)),
+                    Ok(x) => Some(format!("{x}")),
+                    Err(_) => it.value(db).map(|x| format!("{x:?}")),
                 }
             } else {
                 None
@@ -359,7 +427,7 @@ pub(super) fn definition(
         Definition::Const(it) => label_value_and_docs(db, it, |it| {
             let body = it.eval(db);
             match body {
-                Ok(x) => Some(format!("{}", x)),
+                Ok(x) => Some(format!("{x}")),
                 Err(_) => {
                     let source = it.source(db)?;
                     let mut body = source.value.body()?.syntax().clone();
@@ -415,7 +483,7 @@ pub(super) fn definition(
 
 fn render_builtin_attr(db: &RootDatabase, attr: hir::BuiltinAttr) -> Option<Markup> {
     let name = attr.name(db);
-    let desc = format!("#[{}]", name);
+    let desc = format!("#[{name}]");
 
     let AttributeTemplate { word, list, name_value_str } = match attr.template(db) {
         Some(template) => template,
@@ -443,6 +511,25 @@ where
     (label, docs)
 }
 
+fn label_and_layout_info_and_docs<D, E, V>(
+    db: &RootDatabase,
+    def: D,
+    value_extractor: E,
+) -> (String, Option<hir::Documentation>)
+where
+    D: HasAttrs + HirDisplay,
+    E: Fn(&D) -> Option<V>,
+    V: Display,
+{
+    let label = if let Some(value) = value_extractor(&def) {
+        format!("{} // {value}", def.display(db))
+    } else {
+        def.display(db).to_string()
+    };
+    let docs = def.attrs(db).docs();
+    (label, docs)
+}
+
 fn label_value_and_docs<D, E, V>(
     db: &RootDatabase,
     def: D,
@@ -454,7 +541,7 @@ where
     V: Display,
 {
     let label = if let Some(value) = value_extractor(&def) {
-        format!("{} = {}", def.display(db), value)
+        format!("{} = {value}", def.display(db))
     } else {
         def.display(db).to_string()
     };
@@ -518,9 +605,9 @@ fn local(db: &RootDatabase, it: hir::Local) -> Option<Markup> {
             } else {
                 ""
             };
-            format!("{}{}{}: {}", let_kw, is_mut, name, ty)
+            format!("{let_kw}{is_mut}{name}: {ty}")
         }
-        Either::Right(_) => format!("{}self: {}", is_mut, ty),
+        Either::Right(_) => format!("{is_mut}self: {ty}"),
     };
     markup(None, desc, None)
 }