Rollup merge of #103621 - fee1-dead-contrib:iat-fix-use, r=cjgillot

Correctly resolve Inherent Associated Types

I don't know if this is the best way to do this, but at least it is one way.

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1910,6 +1910,20 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
  }
  }
  }
+
+ // see if we can satisfy using an inherent associated type
+ for impl_ in tcx.inherent_impls(adt_def.did()) {
+ let assoc_ty = tcx.associated_items(impl_).find_by_name_and_kind(
+ tcx,
+ assoc_ident,
+ ty::AssocKind::Type,
+ *impl_,
+ );
+ if let Some(assoc_ty) = assoc_ty {
+ let ty = tcx.type_of(assoc_ty.def_id);
+ return Ok((ty, DefKind::AssocTy, assoc_ty.def_id));
+ }
+ }
  }
 
  // Find the type of the associated item, and the trait where the associated

src/librustdoc/clean/mod.rs

@@ -1381,7 +1381,8 @@ fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type
  ty::Projection(proj) => Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id),
  // Rustdoc handles `ty::Error`s by turning them into `Type::Infer`s.
  ty::Error(_) => return Type::Infer,
- _ => bug!("clean: expected associated type, found `{:?}`", ty),
+ // Otherwise, this is an inherent associated type.
+ _ => return clean_middle_ty(ty, cx, None),
  };
  let trait_ = clean_path(&hir::Path { span, res, segments: &[] }, cx);
  register_res(cx, trait_.res);

src/test/rustdoc-ui/ambiguous-inherent-assoc-ty.rs

@@ -1,3 +1,4 @@
+// check-pass
 // This test ensures that rustdoc does not panic on inherented associated types
 // that are referred to without fully-qualified syntax.
 
@@ -9,8 +10,4 @@ pub struct Struct;
 impl Struct {
  pub type AssocTy = usize;
  pub const AssocConst: Self::AssocTy = 42;
- //~^ ERROR ambiguous associated type
- //~| HELP use fully-qualified syntax
- //~| ERROR ambiguous associated type
- //~| HELP use fully-qualified syntax
 }

src/test/ui/associated-inherent-types/assoc-inherent-no-body.rs

@@ -0,0 +1,10 @@
+#![feature(inherent_associated_types)]
+#![allow(incomplete_features)]
+
+struct Foo;
+
+impl Foo {
+ type Baz; //~ ERROR associated type in `impl` without body
+}
+
+fn main() {}

src/test/ui/associated-inherent-types/assoc-inherent-no-body.stderr

@@ -0,0 +1,10 @@
+error: associated type in `impl` without body
+ --> $DIR/assoc-inherent-no-body.rs:7:5
+ |
+LL | type Baz;
+ | ^^^^^^^^-
+ | |
+ | help: provide a definition for the type: `= <type>;`
+
+error: aborting due to previous error
+

src/test/ui/associated-inherent-types/assoc-inherent-use.rs

@@ -0,0 +1,14 @@
+// check-pass
+#![feature(inherent_associated_types)]
+#![allow(incomplete_features)]
+
+struct Foo;
+
+impl Foo {
+ type Bar = isize;
+}
+
+fn main() {
+ let x: Foo::Bar;
+ x = 0isize;
+}

src/test/ui/resolve/resolve-self-in-impl.stderr

@@ -1,40 +1,40 @@
 error: `Self` is not valid in the self type of an impl block
- --> $DIR/resolve-self-in-impl.rs:14:13
+ --> $DIR/resolve-self-in-impl.rs:16:6
  |
-LL | impl Tr for Self {}
- |  ^^^^
+LL | impl Self {}
+ | ^^^^
  |
  = note: replace `Self` with a different type
 
 error: `Self` is not valid in the self type of an impl block
- --> $DIR/resolve-self-in-impl.rs:15:15
+ --> $DIR/resolve-self-in-impl.rs:17:8
  |
-LL | impl Tr for S<Self> {}
- |  ^^^^
+LL | impl S<Self> {}
+ | ^^^^
  |
  = note: replace `Self` with a different type
 
 error: `Self` is not valid in the self type of an impl block
- --> $DIR/resolve-self-in-impl.rs:16:6
+ --> $DIR/resolve-self-in-impl.rs:18:7
  |
-LL | impl Self {}
- | ^^^^
+LL | impl (Self, Self) {}
+ |  ^^^^ ^^^^
  |
  = note: replace `Self` with a different type
 
 error: `Self` is not valid in the self type of an impl block
- --> $DIR/resolve-self-in-impl.rs:17:8
+ --> $DIR/resolve-self-in-impl.rs:14:13
  |
-LL | impl S<Self> {}
- | ^^^^
+LL | impl Tr for Self {}
+ |  ^^^^
  |
  = note: replace `Self` with a different type
 
 error: `Self` is not valid in the self type of an impl block
- --> $DIR/resolve-self-in-impl.rs:18:7
+ --> $DIR/resolve-self-in-impl.rs:15:15
  |
-LL | impl (Self, Self) {}
- | ^^^^ ^^^^
+LL | impl Tr for S<Self> {}
+ |   ^^^^
  |
  = note: replace `Self` with a different type