Merge #7080

7080: Implement ConstParams for HIR r=Veykril a=Veykril

r? @flodiebold 

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

crates/ide/src/display/navigation_target.rs

@@ -24,6 +24,7 @@ pub enum SymbolKind {
     Impl,
     Field,
     TypeParam,
+    ConstParam,
     LifetimeParam,
     ValueParam,
     SelfParam,
@@ -225,6 +226,7 @@ impl TryToNav for Definition {
             Definition::TypeParam(it) => Some(it.to_nav(db)),
             Definition::LifetimeParam(it) => Some(it.to_nav(db)),
             Definition::Label(it) => Some(it.to_nav(db)),
+            Definition::ConstParam(it) => Some(it.to_nav(db)),
         }
     }
 }
@@ -485,6 +487,23 @@ impl ToNav for hir::LifetimeParam {
     }
 }
 
+impl ToNav for hir::ConstParam {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let full_range = src.value.syntax().text_range();
+        NavigationTarget {
+            file_id: src.file_id.original_file(db),
+            name: self.name(db).to_string().into(),
+            kind: Some(SymbolKind::ConstParam),
+            full_range,
+            focus_range: src.value.name().map(|n| n.syntax().text_range()),
+            container_name: None,
+            description: None,
+            docs: None,
+        }
+    }
+}
+
 /// Get a description of a symbol.
 ///
 /// e.g. `struct Name`, `enum Name`, `fn Name`

crates/ide/src/doc_links.rs

@@ -193,6 +193,7 @@ fn rewrite_intra_doc_link(
         Definition::SelfType(_)
         | Definition::Local(_)
         | Definition::TypeParam(_)
+        | Definition::ConstParam(_)
         | Definition::LifetimeParam(_)
         | Definition::Label(_) => return None,
     }?;

crates/ide/src/hover.rs

@@ -370,7 +370,10 @@ fn hover_for_definition(db: &RootDatabase, def: Definition) -> Option<Markup> {
                 Adt::Enum(it) => from_def_source(db, it, mod_path),
             })
         }
-        Definition::TypeParam(_) | Definition::LifetimeParam(_) | Definition::Label(_) => {
+        Definition::TypeParam(_)
+        | Definition::LifetimeParam(_)
+        | Definition::ConstParam(_)
+        | Definition::Label(_) => {
             // FIXME: Hover for generic param
             None
         }

crates/ide/src/references.rs

@@ -1144,4 +1144,20 @@ fn foo<'a>() -> &'a () {
             "#]],
         );
     }
+
+    #[test]
+    fn test_find_const_param() {
+        check(
+            r#"
+fn foo<const FOO<|>: usize>() -> usize {
+    FOO
+}
+"#,
+            expect![[r#"
+                FOO ConstParam FileId(0) 7..23 13..16 Other
+
+                FileId(0) 42..45 Other
+            "#]],
+        );
+    }
 }

crates/ide/src/syntax_highlighting.rs

@@ -819,6 +819,7 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
         },
         Definition::SelfType(_) => HighlightTag::Symbol(SymbolKind::Impl),
         Definition::TypeParam(_) => HighlightTag::Symbol(SymbolKind::TypeParam),
+        Definition::ConstParam(_) => HighlightTag::Symbol(SymbolKind::ConstParam),
         Definition::Local(local) => {
             let tag = if local.is_param(db) {
                 HighlightTag::Symbol(SymbolKind::ValueParam)

crates/ide/src/syntax_highlighting/tags.rs

@@ -77,6 +77,7 @@ impl HighlightTag {
                 SymbolKind::Function => "function",
                 SymbolKind::TypeAlias => "type_alias",
                 SymbolKind::TypeParam => "type_param",
+                SymbolKind::ConstParam => "const_param",
                 SymbolKind::LifetimeParam => "lifetime",
                 SymbolKind::Macro => "macro",
                 SymbolKind::Local => "variable",

crates/ide/src/syntax_highlighting/test_data/highlighting.html

@@ -118,6 +118,10 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="keyword control">loop</span> <span class="punctuation">{</span><span class="punctuation">}</span>
 <span class="punctuation">}</span>
 
+<span class="keyword">fn</span> <span class="function declaration">const_param</span><span class="punctuation">&lt;</span><span class="keyword">const</span> <span class="const_param declaration">FOO</span><span class="punctuation">:</span> <span class="builtin_type">usize</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">usize</span> <span class="punctuation">{</span>
+    <span class="const_param">FOO</span>
+<span class="punctuation">}</span>
+
 <span class="keyword">use</span> <span class="module">ops</span><span class="operator">::</span><span class="trait">Fn</span><span class="punctuation">;</span>
 <span class="keyword">fn</span> <span class="function declaration">baz</span><span class="punctuation">&lt;</span><span class="type_param declaration">F</span><span class="punctuation">:</span> <span class="trait">Fn</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="value_param declaration callable">f</span><span class="punctuation">:</span> <span class="type_param">F</span><span class="punctuation">)</span> <span class="punctuation">{</span>
     <span class="value_param callable">f</span><span class="punctuation">(</span><span class="punctuation">)</span>

crates/ide/src/syntax_highlighting/tests.rs

@@ -91,6 +91,10 @@ fn never() -> ! {
     loop {}
 }
 
+fn const_param<const FOO: usize>() -> usize {
+    FOO
+}
+
 use ops::Fn;
 fn baz<F: Fn() -> ()>(f: F) {
     f()