4 files changed, 251 insertions, 12 deletions

diff --git a/crates/ra_ide_api/src/completion/complete_path.rs b/crates/ra_ide_api/src/completion/complete_path.rs
index a58fdc036..09ca40179 100644
--- a/crates/ra_ide_api/src/completion/complete_path.rs
+++ b/crates/ra_ide_api/src/completion/complete_path.rs
@@ -18,15 +18,15 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
     match def {
         hir::ModuleDef::Module(module) => {
             let module_scope = module.scope(ctx.db);
-            for (name, res) in module_scope.entries() {
-                if let Some(hir::ModuleDef::BuiltinType(..)) = res.def.take_types() {
+            for (name, def, import) in module_scope {
+                if let hir::ScopeDef::ModuleDef(hir::ModuleDef::BuiltinType(..)) = def {
                     if ctx.use_item_syntax.is_some() {
                         tested_by!(dont_complete_primitive_in_use);
                         continue;
                     }
                 }
                 if Some(module) == ctx.module {
-                    if let Some(import) = res.import {
+                    if let Some(import) = import {
                         if let Either::A(use_tree) = module.import_source(ctx.db, import) {
                             if use_tree.syntax().text_range().contains_inclusive(ctx.offset) {
                                 // for `use self::foo<|>`, don't suggest `foo` as a completion
@@ -36,7 +36,7 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
                         }
                     }
                 }
-                acc.add_resolution(ctx, name.to_string(), &res.def.into());
+                acc.add_resolution(ctx, name.to_string(), &def);
             }
         }
         hir::ModuleDef::Adt(_) | hir::ModuleDef::TypeAlias(_) => {
@@ -50,23 +50,46 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
                 hir::ModuleDef::TypeAlias(a) => a.ty(ctx.db),
                 _ => unreachable!(),
             };
+            ctx.analyzer.iterate_path_candidates(ctx.db, ty.clone(), None, |_ty, item| {
+                match item {
+                    hir::AssocItem::Function(func) => {
+                        let data = func.data(ctx.db);
+                        if !data.has_self_param() {
+                            acc.add_function(ctx, func);
+                        }
+                    }
+                    hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                    hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                }
+                None::<()>
+            });
+            // Iterate assoc types separately
+            // FIXME: complete T::AssocType
             let krate = ctx.module.map(|m| m.krate());
             if let Some(krate) = krate {
                 ty.iterate_impl_items(ctx.db, krate, |item| {
                     match item {
-                        hir::AssocItem::Function(func) => {
-                            let data = func.data(ctx.db);
-                            if !data.has_self_param() {
-                                acc.add_function(ctx, func);
-                            }
-                        }
-                        hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                        hir::AssocItem::Function(_) | hir::AssocItem::Const(_) => {}
                         hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
                     }
                     None::<()>
                 });
             }
         }
+        hir::ModuleDef::Trait(t) => {
+            for item in t.items(ctx.db) {
+                match item {
+                    hir::AssocItem::Function(func) => {
+                        let data = func.data(ctx.db);
+                        if !data.has_self_param() {
+                            acc.add_function(ctx, func);
+                        }
+                    }
+                    hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                    hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                }
+            }
+        }
         _ => {}
     };
 }
@@ -559,6 +582,111 @@ mod tests {
     }
 
     #[test]
+    fn completes_trait_associated_method_1() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /lib.rs
+                trait Trait {
+                  /// A trait method
+                  fn m();
+                }
+
+                fn foo() { let _ = Trait::<|> }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "m()",
+                source_range: [73; 73),
+                delete: [73; 73),
+                insert: "m()$0",
+                kind: Function,
+                lookup: "m",
+                detail: "fn m()",
+                documentation: Documentation(
+                    "A trait method",
+                ),
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn completes_trait_associated_method_2() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /lib.rs
+                trait Trait {
+                  /// A trait method
+                  fn m();
+                }
+
+                struct S;
+                impl Trait for S {}
+
+                fn foo() { let _ = S::<|> }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "m()",
+                source_range: [99; 99),
+                delete: [99; 99),
+                insert: "m()$0",
+                kind: Function,
+                lookup: "m",
+                detail: "fn m()",
+                documentation: Documentation(
+                    "A trait method",
+                ),
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn completes_trait_associated_method_3() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /lib.rs
+                trait Trait {
+                  /// A trait method
+                  fn m();
+                }
+
+                struct S;
+                impl Trait for S {}
+
+                fn foo() { let _ = <S as Trait>::<|> }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "m()",
+                source_range: [110; 110),
+                delete: [110; 110),
+                insert: "m()$0",
+                kind: Function,
+                lookup: "m",
+                detail: "fn m()",
+                documentation: Documentation(
+                    "A trait method",
+                ),
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
     fn completes_type_alias() {
         assert_debug_snapshot!(
             do_reference_completion(
diff --git a/crates/ra_ide_api/src/completion/complete_record_literal.rs b/crates/ra_ide_api/src/completion/complete_record_literal.rs
index 4406695d5..0295b8101 100644
--- a/crates/ra_ide_api/src/completion/complete_record_literal.rs
+++ b/crates/ra_ide_api/src/completion/complete_record_literal.rs
@@ -32,6 +32,34 @@ mod tests {
     }
 
     #[test]
+    fn test_record_literal_deprecated_field() {
+        let completions = complete(
+            r"
+            struct A {
+                #[deprecated]
+                the_field: u32,
+            }
+            fn foo() {
+               A { the<|> }
+            }
+            ",
+        );
+        assert_debug_snapshot!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "the_field",
+       ⋮        source_range: [142; 145),
+       ⋮        delete: [142; 145),
+       ⋮        insert: "the_field",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮        deprecated: true,
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
     fn test_record_literal_field() {
         let completions = complete(
             r"
diff --git a/crates/ra_ide_api/src/completion/completion_item.rs b/crates/ra_ide_api/src/completion/completion_item.rs
index 5c9c44704..93f336370 100644
--- a/crates/ra_ide_api/src/completion/completion_item.rs
+++ b/crates/ra_ide_api/src/completion/completion_item.rs
@@ -44,6 +44,9 @@ pub struct CompletionItem {
     /// Additional info to show in the UI pop up.
     detail: Option<String>,
     documentation: Option<Documentation>,
+
+    /// Whether this item is marked as deprecated
+    deprecated: bool,
 }
 
 // We use custom debug for CompletionItem to make `insta`'s diffs more readable.
@@ -70,6 +73,9 @@ impl fmt::Debug for CompletionItem {
         if let Some(documentation) = self.documentation() {
             s.field("documentation", &documentation);
         }
+        if self.deprecated {
+            s.field("deprecated", &true);
+        }
         s.finish()
     }
 }
@@ -132,6 +138,7 @@ impl CompletionItem {
             lookup: None,
             kind: None,
             text_edit: None,
+            deprecated: None,
         }
     }
     /// What user sees in pop-up in the UI.
@@ -166,6 +173,10 @@ impl CompletionItem {
     pub fn kind(&self) -> Option<CompletionItemKind> {
         self.kind
     }
+
+    pub fn deprecated(&self) -> bool {
+        self.deprecated
+    }
 }
 
 /// A helper to make `CompletionItem`s.
@@ -181,6 +192,7 @@ pub(crate) struct Builder {
     lookup: Option<String>,
     kind: Option<CompletionItemKind>,
     text_edit: Option<TextEdit>,
+    deprecated: Option<bool>,
 }
 
 impl Builder {
@@ -208,6 +220,7 @@ impl Builder {
             lookup: self.lookup,
             kind: self.kind,
             completion_kind: self.completion_kind,
+            deprecated: self.deprecated.unwrap_or(false),
         }
     }
     pub(crate) fn lookup_by(mut self, lookup: impl Into<String>) -> Builder {
@@ -254,6 +267,10 @@ impl Builder {
         self.documentation = docs.map(Into::into);
         self
     }
+    pub(crate) fn set_deprecated(mut self, deprecated: bool) -> Builder {
+        self.deprecated = Some(deprecated);
+        self
+    }
 }
 
 impl<'a> Into<CompletionItem> for Builder {
diff --git a/crates/ra_ide_api/src/completion/presentation.rs b/crates/ra_ide_api/src/completion/presentation.rs
index 65bb639ed..cb55d1875 100644
--- a/crates/ra_ide_api/src/completion/presentation.rs
+++ b/crates/ra_ide_api/src/completion/presentation.rs
@@ -2,7 +2,7 @@
 
 use hir::{db::HirDatabase, Docs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
 use join_to_string::join;
-use ra_syntax::ast::NameOwner;
+use ra_syntax::ast::{AttrsOwner, NameOwner};
 use test_utils::tested_by;
 
 use crate::completion::{
@@ -18,6 +18,11 @@ impl Completions {
         field: hir::StructField,
         substs: &hir::Substs,
     ) {
+        let ast_node = field.source(ctx.db).ast;
+        let is_deprecated = match ast_node {
+            hir::FieldSource::Named(m) => is_deprecated(m),
+            hir::FieldSource::Pos(m) => is_deprecated(m),
+        };
         CompletionItem::new(
             CompletionKind::Reference,
             ctx.source_range(),
@@ -26,6 +31,7 @@ impl Completions {
         .kind(CompletionItemKind::Field)
         .detail(field.ty(ctx.db).subst(substs).display(ctx.db).to_string())
         .set_documentation(field.docs(ctx.db))
+        .set_deprecated(is_deprecated)
         .add_to(self);
     }
 
@@ -179,6 +185,7 @@ impl Completions {
             CompletionItem::new(CompletionKind::Reference, ctx.source_range(), &macro_declaration)
                 .kind(CompletionItemKind::Macro)
                 .set_documentation(docs.clone())
+                .set_deprecated(is_deprecated(ast_node))
                 .detail(detail);
 
         builder = if ctx.use_item_syntax.is_some() {
@@ -211,6 +218,7 @@ impl Completions {
                     CompletionItemKind::Function
                 })
                 .set_documentation(func.docs(ctx.db))
+                .set_deprecated(is_deprecated(ast_node))
                 .detail(detail);
 
         // Add `<>` for generic types
@@ -242,6 +250,7 @@ impl Completions {
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.text().to_string())
             .kind(CompletionItemKind::Const)
             .set_documentation(constant.docs(ctx.db))
+            .set_deprecated(is_deprecated(ast_node))
             .detail(detail)
             .add_to(self);
     }
@@ -257,11 +266,13 @@ impl Completions {
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.text().to_string())
             .kind(CompletionItemKind::TypeAlias)
             .set_documentation(type_alias.docs(ctx.db))
+            .set_deprecated(is_deprecated(type_def))
             .detail(detail)
             .add_to(self);
     }
 
     pub(crate) fn add_enum_variant(&mut self, ctx: &CompletionContext, variant: hir::EnumVariant) {
+        let is_deprecated = is_deprecated(variant.source(ctx.db).ast);
         let name = match variant.name(ctx.db) {
             Some(it) => it,
             None => return,
@@ -274,11 +285,16 @@ impl Completions {
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.to_string())
             .kind(CompletionItemKind::EnumVariant)
             .set_documentation(variant.docs(ctx.db))
+            .set_deprecated(is_deprecated)
             .detail(detail)
             .add_to(self);
     }
 }
 
+fn is_deprecated(node: impl AttrsOwner) -> bool {
+    node.attrs().filter_map(|x| x.simple_name()).any(|x| x == "deprecated")
+}
+
 fn has_non_default_type_params(def: hir::GenericDef, db: &db::RootDatabase) -> bool {
     let subst = db.generic_defaults(def);
     subst.iter().any(|ty| ty == &Ty::Unknown)
@@ -296,6 +312,56 @@ mod tests {
     }
 
     #[test]
+    fn sets_deprecated_flag_in_completion_items() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r#"
+                #[deprecated]
+                fn something_deprecated() {}
+
+                #[deprecated(since = "1.0.0")]
+                fn something_else_deprecated() {}
+
+                fn main() { som<|> }
+                "#,
+            ),
+            @r###"
+            [
+                CompletionItem {
+                    label: "main()",
+                    source_range: [203; 206),
+                    delete: [203; 206),
+                    insert: "main()$0",
+                    kind: Function,
+                    lookup: "main",
+                    detail: "fn main()",
+                },
+                CompletionItem {
+                    label: "something_deprecated()",
+                    source_range: [203; 206),
+                    delete: [203; 206),
+                    insert: "something_deprecated()$0",
+                    kind: Function,
+                    lookup: "something_deprecated",
+                    detail: "fn something_deprecated()",
+                    deprecated: true,
+                },
+                CompletionItem {
+                    label: "something_else_deprecated()",
+                    source_range: [203; 206),
+                    delete: [203; 206),
+                    insert: "something_else_deprecated()$0",
+                    kind: Function,
+                    lookup: "something_else_deprecated",
+                    detail: "fn something_else_deprecated()",
+                    deprecated: true,
+                },
+            ]
+            "###
+        );
+    }
+
+    #[test]
     fn inserts_parens_for_function_calls() {
         covers!(inserts_parens_for_function_calls);
         assert_debug_snapshot!(