From 7852b07249aa438bed8428ed804f4a463d6e5bbd Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 30 Mar 2024 12:03:29 -0400 Subject: [PATCH 1/5] Stop chopping off args for no reason --- .../rustc_trait_selection/src/traits/util.rs | 2 -- .../in-trait/span-bug-issue-121457.rs | 1 + .../in-trait/span-bug-issue-121457.stderr | 19 ++++++++++++++++++- 3 files changed, 19 insertions(+), 3 deletions(-) diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs index 466a53d8ce029..50cc0ed90fb2f 100644 --- a/compiler/rustc_trait_selection/src/traits/util.rs +++ b/compiler/rustc_trait_selection/src/traits/util.rs @@ -381,8 +381,6 @@ pub fn check_args_compatible<'tcx>( } let generics = tcx.generics_of(assoc_item.def_id); - // Chop off any additional args (RPITIT) args - let args = &args[0..generics.count().min(args.len())]; check_args_compatible_inner(tcx, generics, args) } diff --git a/tests/ui/impl-trait/in-trait/span-bug-issue-121457.rs b/tests/ui/impl-trait/in-trait/span-bug-issue-121457.rs index ab21dae7dc50d..7a51037324f28 100644 --- a/tests/ui/impl-trait/in-trait/span-bug-issue-121457.rs +++ b/tests/ui/impl-trait/in-trait/span-bug-issue-121457.rs @@ -14,6 +14,7 @@ impl<'a, I: 'a + Iterable> Iterable for &'a I { //~^ ERROR binding for associated type `Item` references lifetime `'missing` //~| ERROR binding for associated type `Item` references lifetime `'missing` //~| ERROR `()` is not an iterator + //~| WARNING impl trait in impl method signature does not match trait method signature } fn main() {} diff --git a/tests/ui/impl-trait/in-trait/span-bug-issue-121457.stderr b/tests/ui/impl-trait/in-trait/span-bug-issue-121457.stderr index d8a2eef94a180..67c4df0f3a9eb 100644 --- a/tests/ui/impl-trait/in-trait/span-bug-issue-121457.stderr +++ b/tests/ui/impl-trait/in-trait/span-bug-issue-121457.stderr @@ -32,7 +32,24 @@ LL | fn iter(&self) -> impl for<'missing> Iterator $DIR/span-bug-issue-121457.rs:13:51 + | +LL | fn iter(&self) -> impl Iterator; + | ------------- return type from trait method defined here +... +LL | fn iter(&self) -> impl for<'missing> Iterator> {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ this bound is stronger than that defined on the trait + | + = note: add `#[allow(refining_impl_trait)]` if it is intended for this to be part of the public API of this crate + = note: we are soliciting feedback, see issue #121718 for more information + = note: `#[warn(refining_impl_trait_reachable)]` on by default +help: replace the return type so that it matches the trait + | +LL | fn iter(&self) -> impl Iterator {} + | ~~~~~~~~~~~~~ + +error: aborting due to 4 previous errors; 1 warning emitted Some errors have detailed explanations: E0195, E0277, E0582. For more information about an error, try `rustc --explain E0195`. From 9be1c3c1f443f1d018b8bf400eae27c68b8c54c9 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 30 Mar 2024 12:05:14 -0400 Subject: [PATCH 2/5] Uplift and start using check_args_compatible more liberally --- compiler/rustc_middle/src/ty/context.rs | 93 +++++++++++++++---- compiler/rustc_middle/src/ty/sty.rs | 34 +++---- .../src/solve/normalizes_to/mod.rs | 4 +- .../rustc_trait_selection/src/traits/mod.rs | 8 +- .../src/traits/project.rs | 3 +- .../rustc_trait_selection/src/traits/util.rs | 40 -------- compiler/rustc_ty_utils/src/opaque_types.rs | 3 +- 7 files changed, 95 insertions(+), 90 deletions(-) diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index 188cb50849dc1..9f33609eae6bd 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -1954,33 +1954,90 @@ impl<'tcx> TyCtxt<'tcx> { if pred.kind() != binder { self.mk_predicate(binder) } else { pred } } + pub fn check_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) -> bool { + self.check_args_compatible_inner(def_id, args, false) + } + + fn check_args_compatible_inner( + self, + def_id: DefId, + args: &'tcx [ty::GenericArg<'tcx>], + nested: bool, + ) -> bool { + let generics = self.generics_of(def_id); + + // IATs themselves have a weird arg setup (self + own args), but nested items *in* IATs + // (namely: opaques, i.e. ATPITs) do not. + let own_args = if !nested + && let DefKind::AssocTy = self.def_kind(def_id) + && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id)) + { + if generics.params.len() + 1 != args.len() { + return false; + } + + if !matches!(args[0].unpack(), ty::GenericArgKind::Type(_)) { + return false; + } + + &args[1..] + } else { + if generics.count() != args.len() { + return false; + } + + let (parent_args, own_args) = args.split_at(generics.parent_count); + + if let Some(parent) = generics.parent + && !self.check_args_compatible_inner(parent, parent_args, true) + { + return false; + } + + own_args + }; + + for (param, arg) in std::iter::zip(&generics.params, own_args) { + match (¶m.kind, arg.unpack()) { + (ty::GenericParamDefKind::Type { .. }, ty::GenericArgKind::Type(_)) + | (ty::GenericParamDefKind::Lifetime, ty::GenericArgKind::Lifetime(_)) + | (ty::GenericParamDefKind::Const { .. }, ty::GenericArgKind::Const(_)) => {} + _ => return false, + } + } + + true + } + + pub fn assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) { + if !self.check_args_compatible(def_id, args) { + if let DefKind::AssocTy = self.def_kind(def_id) + && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id)) + { + bug!() + } else { + bug!( + "args not compatible with generics for {}: args={:#?}, generics={:#?}", + self.def_path_str(def_id), + args, + ty::GenericArgs::identity_for_item(self, def_id) + ); + } + } + } + #[inline(always)] pub(crate) fn check_and_mk_args( self, _def_id: DefId, args: impl IntoIterator>>, ) -> GenericArgsRef<'tcx> { - let args = args.into_iter().map(Into::into); + let args = self.mk_args_from_iter(args.into_iter().map(Into::into)); #[cfg(debug_assertions)] { - let generics = self.generics_of(_def_id); - - let n = if let DefKind::AssocTy = self.def_kind(_def_id) - && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(_def_id)) - { - // If this is an inherent projection. - generics.params.len() + 1 - } else { - generics.count() - }; - assert_eq!( - (n, Some(n)), - args.size_hint(), - "wrong number of generic parameters for {_def_id:?}: {:?}", - args.collect::>(), - ); + self.assert_args_compatible(_def_id, args); } - self.mk_args_from_iter(args) + args } #[inline] diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index b5e619f1e2a3c..dc1ad1da7e1fb 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -1624,13 +1624,9 @@ impl<'tcx> Ty<'tcx> { #[inline] pub fn new_adt(tcx: TyCtxt<'tcx>, def: AdtDef<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> { - debug_assert_eq!( - tcx.generics_of(def.did()).count(), - args.len(), - "wrong number of args for ADT: {:#?} vs {:#?}", - tcx.generics_of(def.did()).params, - args - ); + if cfg!(debug_assertions) { + tcx.assert_args_compatible(def.did(), args); + } Ty::new(tcx, Adt(def, args)) } @@ -1711,11 +1707,9 @@ impl<'tcx> Ty<'tcx> { def_id: DefId, closure_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { - debug_assert_eq!( - closure_args.len(), - tcx.generics_of(tcx.typeck_root_def_id(def_id)).count() + 3, - "closure constructed with incorrect generic parameters" - ); + if cfg!(debug_assertions) { + tcx.assert_args_compatible(def_id, closure_args); + } Ty::new(tcx, Closure(def_id, closure_args)) } @@ -1725,11 +1719,9 @@ impl<'tcx> Ty<'tcx> { def_id: DefId, closure_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { - debug_assert_eq!( - closure_args.len(), - tcx.generics_of(tcx.typeck_root_def_id(def_id)).count() + 5, - "closure constructed with incorrect generic parameters" - ); + if cfg!(debug_assertions) { + tcx.assert_args_compatible(def_id, closure_args); + } Ty::new(tcx, CoroutineClosure(def_id, closure_args)) } @@ -1739,11 +1731,9 @@ impl<'tcx> Ty<'tcx> { def_id: DefId, coroutine_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { - debug_assert_eq!( - coroutine_args.len(), - tcx.generics_of(tcx.typeck_root_def_id(def_id)).count() + 6, - "coroutine constructed with incorrect number of generic parameters" - ); + if cfg!(debug_assertions) { + tcx.assert_args_compatible(def_id, coroutine_args); + } Ty::new(tcx, Coroutine(def_id, coroutine_args)) } diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs index 6668889323512..d8aeadd07b3d9 100644 --- a/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs @@ -1,4 +1,4 @@ -use crate::traits::{check_args_compatible, specialization_graph}; +use crate::traits::specialization_graph; use super::assembly::structural_traits::AsyncCallableRelevantTypes; use super::assembly::{self, structural_traits, Candidate}; @@ -247,7 +247,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> { assoc_def.defining_node, ); - if !check_args_compatible(tcx, assoc_def.item, args) { + if !tcx.check_args_compatible(assoc_def.item.def_id, args) { return error_response( ecx, "associated item has mismatched generic item arguments", diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index c875d3da47e5f..e1b2e5b6c224a 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -61,12 +61,12 @@ pub use self::specialize::{ pub use self::structural_match::search_for_structural_match_violation; pub use self::structural_normalize::StructurallyNormalizeExt; pub use self::util::elaborate; -pub use self::util::{ - check_args_compatible, supertrait_def_ids, supertraits, transitive_bounds, - transitive_bounds_that_define_assoc_item, SupertraitDefIds, -}; pub use self::util::{expand_trait_aliases, TraitAliasExpander}; pub use self::util::{get_vtable_index_of_object_method, impl_item_is_final, upcast_choices}; +pub use self::util::{ + supertrait_def_ids, supertraits, transitive_bounds, transitive_bounds_that_define_assoc_item, + SupertraitDefIds, +}; pub use self::util::{with_replaced_escaping_bound_vars, BoundVarReplacer, PlaceholderReplacer}; pub use rustc_infer::traits::*; diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index c33e24b1094d4..9d744d9a03214 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -2,7 +2,6 @@ use std::ops::ControlFlow; -use super::check_args_compatible; use super::specialization_graph; use super::translate_args; use super::util; @@ -2030,7 +2029,7 @@ fn confirm_impl_candidate<'cx, 'tcx>( } else { ty.map_bound(|ty| ty.into()) }; - if !check_args_compatible(tcx, assoc_ty.item, args) { + if !tcx.check_args_compatible(assoc_ty.item.def_id, args) { let err = Ty::new_error_with_message( tcx, obligation.cause.span, diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs index 50cc0ed90fb2f..d29fc7921bcbd 100644 --- a/compiler/rustc_trait_selection/src/traits/util.rs +++ b/compiler/rustc_trait_selection/src/traits/util.rs @@ -344,46 +344,6 @@ pub enum TupleArgumentsFlag { No, } -// Verify that the trait item and its implementation have compatible args lists -pub fn check_args_compatible<'tcx>( - tcx: TyCtxt<'tcx>, - assoc_item: ty::AssocItem, - args: ty::GenericArgsRef<'tcx>, -) -> bool { - fn check_args_compatible_inner<'tcx>( - tcx: TyCtxt<'tcx>, - generics: &'tcx ty::Generics, - args: &'tcx [ty::GenericArg<'tcx>], - ) -> bool { - if generics.count() != args.len() { - return false; - } - - let (parent_args, own_args) = args.split_at(generics.parent_count); - - if let Some(parent) = generics.parent - && let parent_generics = tcx.generics_of(parent) - && !check_args_compatible_inner(tcx, parent_generics, parent_args) - { - return false; - } - - for (param, arg) in std::iter::zip(&generics.params, own_args) { - match (¶m.kind, arg.unpack()) { - (ty::GenericParamDefKind::Type { .. }, ty::GenericArgKind::Type(_)) - | (ty::GenericParamDefKind::Lifetime, ty::GenericArgKind::Lifetime(_)) - | (ty::GenericParamDefKind::Const { .. }, ty::GenericArgKind::Const(_)) => {} - _ => return false, - } - } - - true - } - - let generics = tcx.generics_of(assoc_item.def_id); - check_args_compatible_inner(tcx, generics, args) -} - /// Executes `f` on `value` after replacing all escaping bound variables with placeholders /// and then replaces these placeholders with the original bound variables in the result. /// diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs index fc16edc6d1309..a652bb781161c 100644 --- a/compiler/rustc_ty_utils/src/opaque_types.rs +++ b/compiler/rustc_ty_utils/src/opaque_types.rs @@ -7,7 +7,6 @@ use rustc_middle::ty::util::{CheckRegions, NotUniqueParam}; use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_middle::ty::{TypeSuperVisitable, TypeVisitable, TypeVisitor}; use rustc_span::Span; -use rustc_trait_selection::traits::check_args_compatible; use crate::errors::{DuplicateArg, NotParam}; @@ -250,7 +249,7 @@ impl<'tcx> TypeVisitor> for OpaqueTypeCollector<'tcx> { ty::GenericArgs::identity_for_item(self.tcx, parent), ); - if check_args_compatible(self.tcx, assoc, impl_args) { + if self.tcx.check_args_compatible(assoc.def_id, impl_args) { self.tcx .type_of(assoc.def_id) .instantiate(self.tcx, impl_args) From ad8e3145e0ee19c64697ff46e824c941c2ed7ccf Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 30 Mar 2024 12:10:47 -0400 Subject: [PATCH 3/5] Simplify some cfging --- compiler/rustc_middle/src/ty/context.rs | 12 +++++++----- compiler/rustc_middle/src/ty/sty.rs | 16 ++++------------ 2 files changed, 11 insertions(+), 17 deletions(-) diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index 9f33609eae6bd..de625f754ab3b 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -2009,7 +2009,12 @@ impl<'tcx> TyCtxt<'tcx> { true } - pub fn assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) { + pub fn debug_assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) { + #[cfg(not(debug_assertions))] + { + return; + } + if !self.check_args_compatible(def_id, args) { if let DefKind::AssocTy = self.def_kind(def_id) && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id)) @@ -2033,10 +2038,7 @@ impl<'tcx> TyCtxt<'tcx> { args: impl IntoIterator>>, ) -> GenericArgsRef<'tcx> { let args = self.mk_args_from_iter(args.into_iter().map(Into::into)); - #[cfg(debug_assertions)] - { - self.assert_args_compatible(_def_id, args); - } + self.debug_assert_args_compatible(_def_id, args); args } diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index dc1ad1da7e1fb..30997d1350d9d 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -1624,9 +1624,7 @@ impl<'tcx> Ty<'tcx> { #[inline] pub fn new_adt(tcx: TyCtxt<'tcx>, def: AdtDef<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> { - if cfg!(debug_assertions) { - tcx.assert_args_compatible(def.did(), args); - } + tcx.debug_assert_args_compatible(def.did(), args); Ty::new(tcx, Adt(def, args)) } @@ -1707,9 +1705,7 @@ impl<'tcx> Ty<'tcx> { def_id: DefId, closure_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { - if cfg!(debug_assertions) { - tcx.assert_args_compatible(def_id, closure_args); - } + tcx.debug_assert_args_compatible(def_id, closure_args); Ty::new(tcx, Closure(def_id, closure_args)) } @@ -1719,9 +1715,7 @@ impl<'tcx> Ty<'tcx> { def_id: DefId, closure_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { - if cfg!(debug_assertions) { - tcx.assert_args_compatible(def_id, closure_args); - } + tcx.debug_assert_args_compatible(def_id, closure_args); Ty::new(tcx, CoroutineClosure(def_id, closure_args)) } @@ -1731,9 +1725,7 @@ impl<'tcx> Ty<'tcx> { def_id: DefId, coroutine_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { - if cfg!(debug_assertions) { - tcx.assert_args_compatible(def_id, coroutine_args); - } + tcx.debug_assert_args_compatible(def_id, coroutine_args); Ty::new(tcx, Coroutine(def_id, coroutine_args)) } From 5bd0be8b042b9d6e09602a9d88951b08c13f4364 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 30 Mar 2024 12:17:21 -0400 Subject: [PATCH 4/5] Don't fill non-ty args with ty::Error --- .../src/hir_ty_lowering/object_safety.rs | 44 ++++++++++++------- 1 file changed, 27 insertions(+), 17 deletions(-) diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs index b5b3a9131c57f..5adf95c7a1456 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs @@ -7,9 +7,10 @@ use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::DefId; use rustc_lint_defs::builtin::UNUSED_ASSOCIATED_TYPE_BOUNDS; -use rustc_middle::ty::{self, Ty}; +use rustc_middle::ty::fold::BottomUpFolder; +use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable}; use rustc_middle::ty::{DynKind, ToPredicate}; -use rustc_span::Span; +use rustc_span::{ErrorGuaranteed, Span}; use rustc_trait_selection::traits::error_reporting::report_object_safety_error; use rustc_trait_selection::traits::{self, hir_ty_lowering_object_safety_violations}; @@ -267,12 +268,17 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { if arg == dummy_self.into() { let param = &generics.params[index]; missing_type_params.push(param.name); - return Ty::new_misc_error(tcx).into(); + Ty::new_misc_error(tcx).into() } else if arg.walk().any(|arg| arg == dummy_self.into()) { references_self = true; - return Ty::new_misc_error(tcx).into(); + let guar = tcx.dcx().span_delayed_bug( + span, + "trait object trait bounds reference `Self`", + ); + replace_dummy_self_with_error(tcx, arg, guar) + } else { + arg } - arg }) .collect(); let args = tcx.mk_args(&args); @@ -327,18 +333,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let guar = tcx .dcx() .span_delayed_bug(span, "trait object projection bounds reference `Self`"); - let args: Vec<_> = b - .projection_ty - .args - .iter() - .map(|arg| { - if arg.walk().any(|arg| arg == dummy_self.into()) { - return Ty::new_error(tcx, guar).into(); - } - arg - }) - .collect(); - b.projection_ty.args = tcx.mk_args(&args); + b.projection_ty = replace_dummy_self_with_error(tcx, b.projection_ty, guar); } ty::ExistentialProjection::erase_self_ty(tcx, b) @@ -396,3 +391,18 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { Ty::new_dynamic(tcx, existential_predicates, region_bound, representation) } } + +fn replace_dummy_self_with_error<'tcx, T: TypeFoldable>>( + tcx: TyCtxt<'tcx>, + t: T, + guar: ErrorGuaranteed, +) -> T { + t.fold_with(&mut BottomUpFolder { + tcx, + ty_op: |ty| { + if ty == tcx.types.trait_object_dummy_self { Ty::new_error(tcx, guar) } else { ty } + }, + lt_op: |lt| lt, + ct_op: |ct| ct, + }) +} From f31dd6b048a614c571e76f128945622cd03823f5 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 30 Mar 2024 12:34:15 -0400 Subject: [PATCH 5/5] Fix up error message for debug_assert_args_compat for IATs --- compiler/rustc_middle/src/ty/context.rs | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index de625f754ab3b..32f715e17884d 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -2009,7 +2009,10 @@ impl<'tcx> TyCtxt<'tcx> { true } + /// With `cfg(debug_assertions)`, assert that args are compatible with their generics, + /// and print out the args if not. pub fn debug_assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) { + // Fast-path for non-debug, bail out early. #[cfg(not(debug_assertions))] { return; @@ -2019,7 +2022,20 @@ impl<'tcx> TyCtxt<'tcx> { if let DefKind::AssocTy = self.def_kind(def_id) && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id)) { - bug!() + bug!( + "args not compatible with generics for {}: args={:#?}, generics={:#?}", + self.def_path_str(def_id), + args, + // Make `[Self, GAT_ARGS...]` (this could be simplified) + self.mk_args_from_iter( + [self.types.self_param.into()].into_iter().chain( + self.generics_of(def_id) + .own_args(ty::GenericArgs::identity_for_item(self, def_id)) + .iter() + .copied() + ) + ) + ); } else { bug!( "args not compatible with generics for {}: args={:#?}, generics={:#?}", @@ -2034,11 +2050,11 @@ impl<'tcx> TyCtxt<'tcx> { #[inline(always)] pub(crate) fn check_and_mk_args( self, - _def_id: DefId, + def_id: DefId, args: impl IntoIterator>>, ) -> GenericArgsRef<'tcx> { let args = self.mk_args_from_iter(args.into_iter().map(Into::into)); - self.debug_assert_args_compatible(_def_id, args); + self.debug_assert_args_compatible(def_id, args); args }