debug!("build: input_or_output={:?}", ty);
// We add implied bounds from both the unnormalized and normalized ty
// See issue #87748
- let constraints_implied_1 = self.add_implied_bounds(ty);
let TypeOpOutput { output: norm_ty, constraints: constraints1, .. } = self
.param_env
.and(type_op::normalize::Normalize::new(ty))
// }
// ```
// Both &Self::Bar and &() are WF
- let constraints_implied_2 =
- if ty != norm_ty { self.add_implied_bounds(norm_ty) } else { None };
+ let constraints_implied = self.add_implied_bounds(norm_ty);
normalized_inputs_and_output.push(norm_ty);
- constraints1.into_iter().chain(constraints_implied_1).chain(constraints_implied_2)
+ constraints1.into_iter().chain(constraints_implied)
})
.collect();
// First liberate late bound regions and subst placeholders
let trait_sig = tcx.liberate_late_bound_regions(impl_m.def_id, tcx.fn_sig(trait_m.def_id));
let trait_sig = trait_sig.subst(tcx, trait_to_placeholder_substs);
- // Next, add all inputs and output as well-formed tys. Importantly,
- // we have to do this before normalization, since the normalized ty may
- // not contain the input parameters. See issue #87748.
- wf_tys.extend(trait_sig.inputs_and_output.iter());
let trait_sig =
inh.normalize_associated_types_in(impl_m_span, impl_m_hir_id, param_env, trait_sig);
- // Also add the resulting inputs and output as well-formed.
- // This probably isn't strictly necessary.
+ // Add the resulting inputs and output as well-formed.
wf_tys.extend(trait_sig.inputs_and_output.iter());
let trait_fty = tcx.mk_fn_ptr(ty::Binder::dummy(trait_sig));
let mut wf_tys = FxHashSet::default();
// Compute the fty from point of view of inside the fn.
let fn_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), fn_sig);
- wf_tys.extend(fn_sig.inputs_and_output.iter());
let fn_sig = inh.normalize_associated_types_in(
body.value.span,
body_id.hir_id,
) {
let sig = fcx.tcx.liberate_late_bound_regions(def_id, sig);
- // Unnormalized types in signature are WF too
- implied_bounds.extend(sig.inputs());
- // FIXME(#27579) return types should not be implied bounds
- implied_bounds.insert(sig.output());
-
// Normalize the input and output types one at a time, using a different
// `WellFormedLoc` for each. We cannot call `normalize_associated_types`
// on the entire `FnSig`, since this would use the same `WellFormedLoc`
--- /dev/null
+// check-fail
+// See issue #91068. Types in the substs of an associated type can't be implied
+// to be WF, since they don't actually have to be constructed.
+
+trait Trait {
+ type Type;
+}
+
+impl<T> Trait for T {
+ type Type = ();
+}
+
+fn f<'a, 'b>(s: &'b str, _: <&'a &'b () as Trait>::Type) -> &'a str {
+ s //~ ERROR lifetime mismatch [E0623]
+}
+
+fn main() {
+ let x = String::from("Hello World!");
+ let y = f(&x, ());
+ drop(x);
+ println!("{}", y);
+}
--- /dev/null
+error[E0623]: lifetime mismatch
+ --> $DIR/implied-bounds-unnorm-associated-type.rs:14:5
+ |
+LL | fn f<'a, 'b>(s: &'b str, _: <&'a &'b () as Trait>::Type) -> &'a str {
+ | ------- ----------
+ | |
+ | these two types are declared with different lifetimes...
+LL | s
+ | ^ ...but data from `s` flows here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0623`.
+++ /dev/null
-// Checks that we properly add implied bounds from unnormalized projections in
-// inputs when typechecking functions.
-
-// check-pass
-
-#![feature(generic_associated_types)]
-
-trait MyTrait {
- type Assoc<'a, 'b> where 'b: 'a;
- fn do_sth(arg: Self::Assoc<'_, '_>);
-}
-
-struct A;
-struct B;
-struct C;
-
-impl MyTrait for A {
- type Assoc<'a, 'b> where 'b: 'a = u32;
- fn do_sth(_: u32) {}
-}
-impl MyTrait for B {
- type Assoc<'a, 'b> where 'b: 'a = u32;
- fn do_sth(_: Self::Assoc<'_, '_>) {}
-}
-impl MyTrait for C {
- type Assoc<'a, 'b> where 'b: 'a = u32;
- fn do_sth(_: Self::Assoc<'static, 'static>) {}
-}
-
-fn main () {}