Rollup merge of #61118 - pnkfelix:issue-60654-dont-ice-on-gat, r=varkor

Dont ICE on an attempt to use GAT without feature gate

Fix #60654
This commit is contained in:
Mazdak Farrokhzad 2019-05-25 04:55:39 +02:00 committed by GitHub
commit 57139e2055
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4 changed files with 40 additions and 10 deletions

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@ -658,12 +658,15 @@ impl<'tcx> ScopeTree {
// The lifetime was defined on node that doesn't own a body,
// which in practice can only mean a trait or an impl, that
// is the parent of a method, and that is enforced below.
assert_eq!(Some(param_owner_id), self.root_parent,
"free_scope: {:?} not recognized by the \
region scope tree for {:?} / {:?}",
param_owner,
self.root_parent.map(|id| tcx.hir().local_def_id_from_hir_id(id)),
self.root_body.map(|hir_id| DefId::local(hir_id.owner)));
if Some(param_owner_id) != self.root_parent {
tcx.sess.delay_span_bug(
DUMMY_SP,
&format!("free_scope: {:?} not recognized by the \
region scope tree for {:?} / {:?}",
param_owner,
self.root_parent.map(|id| tcx.hir().local_def_id_from_hir_id(id)),
self.root_body.map(|hir_id| DefId::local(hir_id.owner))));
}
// The trait/impl lifetime is in scope for the method's body.
self.root_body.unwrap().local_id

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@ -479,21 +479,22 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for SubstFolder<'a, 'gcx, 'tcx> {
// the specialized routine `ty::replace_late_regions()`.
match *r {
ty::ReEarlyBound(data) => {
let r = self.substs.get(data.index as usize).map(|k| k.unpack());
match r {
let rk = self.substs.get(data.index as usize).map(|k| k.unpack());
match rk {
Some(UnpackedKind::Lifetime(lt)) => {
self.shift_region_through_binders(lt)
}
_ => {
let span = self.span.unwrap_or(DUMMY_SP);
span_bug!(
span,
let msg = format!(
"Region parameter out of range \
when substituting in region {} (root type={:?}) \
(index={})",
data.name,
self.root_ty,
data.index);
self.tcx.sess.delay_span_bug(span, &msg);
r
}
}
}

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@ -0,0 +1,14 @@
// rust-lang/rust#60654: Do not ICE on an attempt to use GATs that is
// missing the feature gate.
struct Foo;
impl Iterator for Foo {
type Item<'b> = &'b Foo; //~ ERROR generic associated types are unstable [E0658]
fn next(&mut self) -> Option<Self::Item> {
None
}
}
fn main() { }

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@ -0,0 +1,12 @@
error[E0658]: generic associated types are unstable
--> $DIR/gat-dont-ice-on-absent-feature.rs:7:5
|
LL | type Item<'b> = &'b Foo;
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: for more information, see https://github.com/rust-lang/rust/issues/44265
= help: add #![feature(generic_associated_types)] to the crate attributes to enable
error: aborting due to previous error
For more information about this error, try `rustc --explain E0658`.