diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs index 7f16634afe..46d24b9f14 100644 --- a/crates/hir/src/lib.rs +++ b/crates/hir/src/lib.rs @@ -2777,9 +2777,10 @@ impl Type { self.ty.is_unknown() } - /// Checks that particular type `ty` implements `std::future::Future`. + /// Checks that particular type `ty` implements `std::future::IntoFuture` or + /// `std::future::Future`. /// This function is used in `.await` syntax completion. - pub fn impls_future(&self, db: &dyn HirDatabase) -> bool { + pub fn impls_into_future(&self, db: &dyn HirDatabase) -> bool { let trait_ = db .lang_item(self.env.krate, SmolStr::new_inline("into_future")) .and_then(|it| { diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs index 756772cf84..9418afa91d 100644 --- a/crates/hir/src/source_analyzer.rs +++ b/crates/hir/src/source_analyzer.rs @@ -27,6 +27,7 @@ use hir_def::{ use hir_expand::{ builtin_fn_macro::BuiltinFnLikeExpander, hygiene::Hygiene, + mod_path::path, name, name::{AsName, Name}, HirFileId, InFile, @@ -269,16 +270,35 @@ impl SourceAnalyzer { db: &dyn HirDatabase, await_expr: &ast::AwaitExpr, ) -> Option { - // FIXME This should be pointing to the poll of IntoFuture::Output's Future impl, but I - // don't know how to resolve the Output type so that we can query for its poll method. - let ty = self.ty_of_expr(db, &await_expr.expr()?.into())?; + let mut ty = self.ty_of_expr(db, &await_expr.expr()?.into())?.clone(); - let op_fn = db + let into_future_trait = self + .resolver + .resolve_known_trait(db.upcast(), &path![core::future::IntoFuture]) + .map(Trait::from); + + if let Some(into_future_trait) = into_future_trait { + let type_ = Type::new_with_resolver(db, &self.resolver, ty.clone()); + if type_.impls_trait(db, into_future_trait, &[]) { + let items = into_future_trait.items(db); + let into_future_type = items.into_iter().find_map(|item| match item { + AssocItem::TypeAlias(alias) + if alias.name(db) == hir_expand::name![IntoFuture] => + { + Some(alias) + } + _ => None, + })?; + let future_trait = type_.normalize_trait_assoc_type(db, &[], into_future_type)?; + ty = future_trait.ty; + } + } + + let poll_fn = db .lang_item(self.resolver.krate(), hir_expand::name![poll].to_smol_str())? .as_function()?; - let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn).push(ty.clone()).build(); - - Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs)) + let substs = hir_ty::TyBuilder::subst_for_def(db, poll_fn).push(ty.clone()).build(); + Some(self.resolve_impl_method_or_trait_def(db, poll_fn, &substs)) } pub(crate) fn resolve_prefix_expr( diff --git a/crates/ide-completion/src/completions/dot.rs b/crates/ide-completion/src/completions/dot.rs index cf40ca489c..02004ff7b6 100644 --- a/crates/ide-completion/src/completions/dot.rs +++ b/crates/ide-completion/src/completions/dot.rs @@ -19,7 +19,7 @@ pub(crate) fn complete_dot( }; // Suggest .await syntax for types that implement Future trait - if receiver_ty.impls_future(ctx.db) { + if receiver_ty.impls_into_future(ctx.db) { let mut item = CompletionItem::new(CompletionItemKind::Keyword, ctx.source_range(), "await"); item.detail("expr.await"); diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs index b2123b9a87..c7a922e6cc 100644 --- a/crates/ide/src/goto_definition.rs +++ b/crates/ide/src/goto_definition.rs @@ -1664,6 +1664,40 @@ fn f() { ); } + #[test] + fn goto_await_into_future_poll() { + check( + r#" +//- minicore: future + +struct Futurable; + +impl core::future::IntoFuture for Futurable { + type IntoFuture = MyFut; +} + +struct MyFut; + +impl core::future::Future for MyFut { + type Output = (); + + fn poll( + //^^^^ + self: std::pin::Pin<&mut Self>, + cx: &mut std::task::Context<'_> + ) -> std::task::Poll + { + () + } +} + +fn f() { + Futurable.await$0; +} +"#, + ); + } + #[test] fn goto_try_op() { check(