diff options
| -rw-r--r-- | compiler/rustc_typeck/src/astconv/mod.rs | 46 | ||||
| -rw-r--r-- | src/test/ui/traits/alias/self-in-generics.rs | 7 | ||||
| -rw-r--r-- | src/test/ui/traits/alias/self-in-generics.stderr | 2 |
3 files changed, 41 insertions, 14 deletions
diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs index 1e6cb53f3ee..ff81747cafe 100644 --- a/compiler/rustc_typeck/src/astconv/mod.rs +++ b/compiler/rustc_typeck/src/astconv/mod.rs @@ -35,7 +35,7 @@ use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECT use rustc_span::edition::Edition; use rustc_span::lev_distance::find_best_match_for_name; use rustc_span::symbol::{kw, Ident, Symbol}; -use rustc_span::{Span, DUMMY_SP}; +use rustc_span::Span; use rustc_target::spec::abi; use rustc_trait_selection::traits; use rustc_trait_selection::traits::astconv_object_safety_violations; @@ -1458,16 +1458,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { if ty == dummy_self { let param = &generics.params[index]; missing_type_params.push(param.name); - tcx.ty_error().into() + return tcx.ty_error().into(); } else if ty.walk().any(|arg| arg == dummy_self.into()) { references_self = true; - tcx.ty_error().into() - } else { - arg + return tcx.ty_error().into(); } - } else { - arg } + arg }) .collect(); let substs = tcx.intern_substs(&substs[..]); @@ -1506,13 +1503,36 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { }); let existential_projections = bounds.projection_bounds.iter().map(|(bound, _)| { - bound.map_bound(|b| { - if b.projection_ty.self_ty() != dummy_self { - tcx.sess.delay_span_bug( - DUMMY_SP, - &format!("trait_ref_to_existential called on {:?} with non-dummy Self", b), - ); + bound.map_bound(|mut b| { + assert_eq!(b.projection_ty.self_ty(), dummy_self); + + // Like for trait refs, verify that `dummy_self` did not leak inside default type + // parameters. + let references_self = b.projection_ty.substs.iter().skip(1).any(|arg| { + if let ty::GenericArgKind::Type(ty) = arg.unpack() { + if ty == dummy_self || ty.walk().any(|arg| arg == dummy_self.into()) { + return true; + } + } + false + }); + if references_self { + tcx.sess + .delay_span_bug(span, "trait object projection bounds reference `Self`"); + let substs: Vec<_> = b + .projection_ty + .substs + .iter() + .map(|arg| { + if let ty::GenericArgKind::Type(_) = arg.unpack() { + return tcx.ty_error().into(); + } + arg + }) + .collect(); + b.projection_ty.substs = tcx.intern_substs(&substs[..]); } + ty::ExistentialProjection::erase_self_ty(tcx, b) }) }); diff --git a/src/test/ui/traits/alias/self-in-generics.rs b/src/test/ui/traits/alias/self-in-generics.rs index 6b99431f5bb..0bb6335f91e 100644 --- a/src/test/ui/traits/alias/self-in-generics.rs +++ b/src/test/ui/traits/alias/self-in-generics.rs @@ -1,3 +1,10 @@ +// astconv uses `FreshTy(0)` as a dummy `Self` type when instanciating trait objects. +// This `FreshTy(0)` can leak into substs, causing ICEs in several places. +// Using `save-analysis` triggers type-checking `f` that would be normally skipped +// as `type_of` emitted an error. +// +// compile-flags: -Zsave-analysis + #![feature(trait_alias)] pub trait SelfInput = Fn(&mut Self); diff --git a/src/test/ui/traits/alias/self-in-generics.stderr b/src/test/ui/traits/alias/self-in-generics.stderr index a1056872ea6..110d60e6e91 100644 --- a/src/test/ui/traits/alias/self-in-generics.stderr +++ b/src/test/ui/traits/alias/self-in-generics.stderr @@ -1,5 +1,5 @@ error[E0038]: the trait alias `SelfInput` cannot be made into an object - --> $DIR/self-in-generics.rs:5:19 + --> $DIR/self-in-generics.rs:12:19 | LL | pub fn f(_f: &dyn SelfInput) {} | ^^^^^^^^^ |