mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Pull out some shared code into a new function

Browse Source
This commit is contained in:
Steven Malis 2020-07-25 02:03:50 -07:00
parent 0e11fc8053
commit 9e42d3e434
1 changed files with 44 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

84
src/librustc_typeck/astconv.rs
View File

@ -1483,36 +1483,25 @@ fn add_predicates_for_ast_type_binding(
tcx.collect_referenced_late_bound_regions(&ty::Binder::bind(ty));
debug!("late_bound_in_trait_ref = {:?}", late_bound_in_trait_ref);
debug!("late_bound_in_ty = {:?}", late_bound_in_ty);
for br in late_bound_in_ty.difference(&late_bound_in_trait_ref) {
let br_name = match *br {
ty::BrNamed(_, name) => format!("lifetime `{}`", name),
_ => "an anonymous lifetime".to_string(),
};
// FIXME: point at the type params that don't have appropriate lifetimes:
// struct S1<F: for<'a> Fn(&i32, &i32) -> &'a i32>(F);
// ---- ---- ^^^^^^^
let mut err = struct_span_err!(
tcx.sess,
binding.span,
E0582,
"binding for associated type `{}` references {}, \
which does not appear in the trait input types",
binding.item_name,
br_name
);
if let ty::BrAnon(_) = *br {
// The only way for an anonymous lifetime to wind up
// in the return type but **also** be unconstrained is
// if it only appears in "associated types" in the
// input. See #62200 for an example. In this case,
// though we can easily give a hint that ought to be
// relevant.
err.note("lifetimes appearing in an associated type are not considered constrained");
}
err.emit();
}
// FIXME: point at the type params that don't have appropriate lifetimes:
// struct S1<F: for<'a> Fn(&i32, &i32) -> &'a i32>(F);
// ---- ---- ^^^^^^^
self.validate_late_bound_regions(
late_bound_in_trait_ref,
late_bound_in_ty,
|br_name| {
struct_span_err!(
tcx.sess,
binding.span,
E0582,
"binding for associated type `{}` references {}, \
which does not appear in the trait input types",
binding.item_name,
br_name
)
},
);
}
}
@ -3085,33 +3074,48 @@ pub fn ty_of_fn(
tcx.collect_constrained_late_bound_regions(&inputs.map_bound(|i| i.to_owned()));
let output = bare_fn_ty.output();
let late_bound_in_ret = tcx.collect_referenced_late_bound_regions(&output);
for br in late_bound_in_ret.difference(&late_bound_in_args) {
let lifetime_name = match *br {
ty::BrNamed(_, name) => format!("lifetime `{}`,", name),
ty::BrAnon(_) | ty::BrEnv => "an anonymous lifetime".to_string(),
};
let mut err = struct_span_err!(
self.validate_late_bound_regions(late_bound_in_args, late_bound_in_ret, |br_name| {
struct_span_err!(
tcx.sess,
decl.output.span(),
E0581,
"return type references {} which is not constrained by the fn input types",
lifetime_name
);
br_name
)
});
bare_fn_ty
}
fn validate_late_bound_regions(
&self,
constrained_regions: FxHashSet<ty::BoundRegion>,
referenced_regions: FxHashSet<ty::BoundRegion>,
generate_err: impl Fn(&str) -> rustc_errors::DiagnosticBuilder<'tcx>,
) {
for br in referenced_regions.difference(&constrained_regions) {
let br_name = match *br {
ty::BrNamed(_, name) => format!("lifetime `{}`", name),
ty::BrAnon(_) | ty::BrEnv => "an anonymous lifetime".to_string(),
};
let mut err = generate_err(&br_name);
if let ty::BrAnon(_) = *br {
// The only way for an anonymous lifetime to wind up
// in the return type but **also** be unconstrained is
// if it only appears in "associated types" in the
// input. See #47511 for an example. In this case,
// input. See #47511 and #62200 for examples. In this case,
// though we can easily give a hint that ought to be
// relevant.
err.note(
"lifetimes appearing in an associated type are not considered constrained",
);
}
err.emit();
}
bare_fn_ty
}
/// Given the bounds on an object, determines what single region bound (if any) we can