bjoernager/rust
bjoernager/rust
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This commit is contained in:
Jack Huey 2021-04-21 11:49:59 -04:00
parent 4568e7d62e
commit b78c0d8a4d
2 changed files with 33 additions and 36 deletions
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54
compiler/rustc_ast_passes/src/ast_validation.rs
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@ -81,13 +81,6 @@ struct AstValidator<'a> {
is_assoc_ty_bound_banned: bool,
lint_buffer: &'a mut LintBuffer,
/// This is slightly complicated. Our representation for poly-trait-refs contains a single
/// binder and thus we only allow a single level of quantification. However,
/// the syntax of Rust permits quantification in two places in where clauses,
/// e.g., `T: for <'a> Foo<'a>` and `for <'a, 'b> &'b T: Foo<'a>`. If both are
/// defined, then error.
trait_ref_hack: bool,
}
impl<'a> AstValidator<'a> {
@ -1227,17 +1220,33 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
// A type binding, eg `for<'c> Foo: Send+Clone+'c`
self.check_late_bound_lifetime_defs(&bound_pred.bound_generic_params);
self.visit_ty(&bound_pred.bounded_ty);
self.trait_ref_hack = !bound_pred.bound_generic_params.is_empty();
walk_list!(self, visit_param_bound, &bound_pred.bounds);
walk_list!(self, visit_generic_param, &bound_pred.bound_generic_params);
self.trait_ref_hack = false;
}
_ => {
self.visit_where_predicate(predicate);
// This is slightly complicated. Our representation for poly-trait-refs contains a single
// binder and thus we only allow a single level of quantification. However,
// the syntax of Rust permits quantification in two places in where clauses,
// e.g., `T: for <'a> Foo<'a>` and `for <'a, 'b> &'b T: Foo<'a>`. If both are
// defined, then error.
if !bound_pred.bound_generic_params.is_empty() {
for bound in &bound_pred.bounds {
match bound {
GenericBound::Trait(t, _) => {
if !t.bound_generic_params.is_empty() {
struct_span_err!(
self.err_handler(),
t.span,
E0316,
"nested quantification of lifetimes"
)
.emit();
}
}
GenericBound::Outlives(_) => {}
}
}
}
}
_ => {}
}
self.visit_where_predicate(predicate);
}
}
@ -1289,19 +1298,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
fn visit_poly_trait_ref(&mut self, t: &'a PolyTraitRef, m: &'a TraitBoundModifier) {
self.check_late_bound_lifetime_defs(&t.bound_generic_params);
if self.trait_ref_hack && !t.bound_generic_params.is_empty() {
struct_span_err!(
self.err_handler(),
t.span,
E0316,
"nested quantification of lifetimes"
)
.emit();
}
let trait_ref_hack = self.trait_ref_hack;
self.trait_ref_hack = false;
visit::walk_poly_trait_ref(self, t, m);
self.trait_ref_hack = trait_ref_hack;
}
fn visit_variant_data(&mut self, s: &'a VariantData) {
@ -1520,7 +1517,6 @@ pub fn check_crate(session: &Session, krate: &Crate, lints: &mut LintBuffer) ->
is_impl_trait_banned: false,
is_assoc_ty_bound_banned: false,
lint_buffer: lints,
trait_ref_hack: false,
};
visit::walk_crate(&mut validator, krate);